[clang] nonblocking/nonallocating attributes (was: nolock/noalloc) (PR #84983)

Doug Wyatt via cfe-commits cfe-commits at lists.llvm.org
Thu Apr 25 10:10:59 PDT 2024


https://github.com/dougsonos updated https://github.com/llvm/llvm-project/pull/84983

>From 0619e30a3a4be724185406fad2413c786e2acff1 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Mon, 11 Mar 2024 17:19:01 -0700
Subject: [PATCH 01/40] Initial squash/cleanup

---
 clang/include/clang/AST/Decl.h                |    9 +
 clang/include/clang/AST/Type.h                |  297 +++-
 clang/include/clang/AST/TypeProperties.td     |    5 +
 clang/include/clang/Basic/Attr.td             |   23 +
 clang/include/clang/Basic/AttrDocs.td         |   17 +
 clang/include/clang/Basic/DiagnosticGroups.td |    4 +
 .../clang/Basic/DiagnosticSemaKinds.td        |   95 ++
 clang/include/clang/Sema/Sema.h               |   16 +
 clang/lib/AST/ASTContext.cpp                  |   31 +-
 clang/lib/AST/Decl.cpp                        |   85 +
 clang/lib/AST/Type.cpp                        |  275 +++
 clang/lib/AST/TypePrinter.cpp                 |   14 +
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 1491 +++++++++++++++++
 clang/lib/Sema/Sema.cpp                       |   24 +
 clang/lib/Sema/SemaDecl.cpp                   |   89 +
 clang/lib/Sema/SemaDeclAttr.cpp               |   28 +
 clang/lib/Sema/SemaDeclCXX.cpp                |   20 +
 clang/lib/Sema/SemaExpr.cpp                   |    4 +
 clang/lib/Sema/SemaExprCXX.cpp                |    8 +-
 clang/lib/Sema/SemaLambda.cpp                 |    5 +
 clang/lib/Sema/SemaOverload.cpp               |   27 +
 clang/lib/Sema/SemaType.cpp                   |  130 +-
 clang/test/Sema/attr-nolock.cpp               |   78 +
 clang/test/Sema/attr-nolock2.cpp              |   88 +
 clang/test/Sema/attr-nolock3.cpp              |  144 ++
 25 files changed, 2997 insertions(+), 10 deletions(-)
 create mode 100644 clang/test/Sema/attr-nolock.cpp
 create mode 100644 clang/test/Sema/attr-nolock2.cpp
 create mode 100644 clang/test/Sema/attr-nolock3.cpp

diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index a5879591f4c659..0460f30ce8a8b4 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -3008,6 +3008,13 @@ class FunctionDecl : public DeclaratorDecl,
   /// computed and stored.
   unsigned getODRHash() const;
 
+  FunctionEffectSet getFunctionEffects() const {
+    const auto *FPT = getType()->getAs<FunctionProtoType>();
+    if (FPT)
+      return FPT->getFunctionEffects();
+    return {};
+  }
+
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) {
@@ -4633,6 +4640,8 @@ class BlockDecl : public Decl, public DeclContext {
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
+  FunctionEffectSet getFunctionEffects() const;
+
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) { return K == Block; }
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 1942b0e67f65a3..41c60a6e221d4e 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4047,8 +4047,12 @@ class FunctionType : public Type {
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasArmTypeAttributes : 1;
 
+    LLVM_PREFERRED_TYPE(bool)
+    unsigned HasFunctionEffects : 1;
+
     FunctionTypeExtraBitfields()
-        : NumExceptionType(0), HasArmTypeAttributes(false) {}
+        : NumExceptionType(0), HasArmTypeAttributes(false),
+          HasFunctionEffects(false) {}
   };
 
   /// The AArch64 SME ACLE (Arm C/C++ Language Extensions) define a number
@@ -4181,6 +4185,131 @@ class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
   }
 };
 
+class FunctionEffect;
+class FunctionEffectSet;
+
+// It is the user's responsibility to keep this in set form: elements are
+// ordered and unique.
+// We could hide the mutating methods which are capable of breaking the
+// invariant, but they're needed and safe when used with STL set algorithms.
+class MutableFunctionEffectSet : public SmallVector<const FunctionEffect *, 4> {
+public:
+  using SmallVector::insert;
+  using SmallVector::SmallVector;
+
+  /// Maintains order/uniquenesss.
+  void insert(const FunctionEffect *effect);
+
+  MutableFunctionEffectSet &operator|=(FunctionEffectSet rhs);
+};
+
+class FunctionEffectSet {
+public:
+  // These sets will tend to be very small (1 element), so represent them as
+  // sorted vectors, which are compatible with the STL set algorithms. Using an
+  // array or vector also means the elements are contiguous, keeping iterators
+  // simple.
+
+private:
+  // 'Uniqued' refers to the set itself being uniqued. Storage is allocated
+  // separately. Use ArrayRef for its iterators. Subclass so as to be able to
+  // compare (it seems ArrayRef would silently convert itself to a vector for
+  // comparison?!).
+  class UniquedAndSortedFX : public llvm::ArrayRef<const FunctionEffect *> {
+  public:
+    using Base = llvm::ArrayRef<const FunctionEffect *>;
+
+    UniquedAndSortedFX(Base Array) : Base(Array) {}
+    UniquedAndSortedFX(const FunctionEffect **Ptr, size_t Len)
+        : Base(ptr, len) {}
+
+    bool operator<(const UniquedAndSortedFX &rhs) const;
+  };
+
+  // Could have used a TinyPtrVector if it were unique-able.
+  // Empty set has a null Impl.
+  llvm::PointerUnion<const FunctionEffect *, const UniquedAndSortedFX *> Impl;
+
+  explicit FunctionEffectSet(const FunctionEffect *Single) : Impl(Single) {}
+  explicit FunctionEffectSet(const UniquedAndSortedFX *Multi) : Impl(Multi) {}
+
+public:
+  using Differences =
+      SmallVector<std::pair<const FunctionEffect *, bool /*added*/>>;
+
+  FunctionEffectSet() : Impl(nullptr) {}
+
+  void *getOpaqueValue() const { return Impl.getOpaqueValue(); }
+
+  explicit operator bool() const { return !empty(); }
+  bool empty() const {
+    if (Impl.isNull())
+      return true;
+    if (const UniquedAndSortedFX *Vec =
+            dyn_cast_if_present<const UniquedAndSortedFX *>(Impl))
+      return Vec->empty();
+    return false;
+  }
+  size_t size() const {
+    if (empty())
+      return 0;
+    if (isa<const FunctionEffect *>(Impl))
+      return 1;
+    return cast<const UniquedAndSortedFX *>(Impl)->size();
+  }
+
+  using iterator = const FunctionEffect *const *;
+
+  iterator begin() const {
+    if (isa<const FunctionEffect *>(Impl))
+      return Impl.getAddrOfPtr1();
+    return cast<const UniquedAndSortedFX *>(Impl)->begin();
+  }
+
+  iterator end() const {
+    if (isa<const FunctionEffect *>(Impl))
+      return begin() + (Impl.isNull() ? 0 : 1);
+    return cast<const UniquedAndSortedFX *>(Impl)->end();
+  }
+
+  ArrayRef<const FunctionEffect *> items() const { return {begin(), end()}; }
+
+  // Since iterators are non-trivial and sets are very often empty,
+  // encourage short-circuiting loops for the empty set.
+  // void for_each(llvm::function_ref<void(const FunctionEffect*)> func) const;
+
+  bool operator==(const FunctionEffectSet &other) const {
+    return Impl == other.Impl;
+  }
+  bool operator!=(const FunctionEffectSet &other) const {
+    return Impl != other.Impl;
+  }
+  bool operator<(const FunctionEffectSet &other) const;
+
+  void dump(llvm::raw_ostream &OS) const;
+
+  /// Factory functions: return instances with uniqued implementations.
+  static FunctionEffectSet create(const FunctionEffect &single) {
+    return FunctionEffectSet{&single};
+  }
+  static FunctionEffectSet create(llvm::ArrayRef<const FunctionEffect *> items);
+
+  /// Union. Caller should check for incompatible effects.
+  FunctionEffectSet operator|(const FunctionEffectSet &rhs) const;
+  /// Intersection.
+  MutableFunctionEffectSet operator&(const FunctionEffectSet &rhs) const;
+  /// Difference.
+  MutableFunctionEffectSet operator-(const FunctionEffectSet &rhs) const;
+
+  /// Caller should short-circuit by checking for equality first.
+  static Differences differences(const FunctionEffectSet &Old,
+                                 const FunctionEffectSet &New);
+
+  /// Extract the effects from a Type if it is a BlockType or FunctionProtoType,
+  /// or pointer to one.
+  static FunctionEffectSet get(const Type &TyRef);
+};
+
 /// Represents a prototype with parameter type info, e.g.
 /// 'int foo(int)' or 'int foo(void)'.  'void' is represented as having no
 /// parameters, not as having a single void parameter. Such a type can have
@@ -4195,7 +4324,8 @@ class FunctionProtoType final
           FunctionProtoType, QualType, SourceLocation,
           FunctionType::FunctionTypeExtraBitfields,
           FunctionType::FunctionTypeArmAttributes, FunctionType::ExceptionType,
-          Expr *, FunctionDecl *, FunctionType::ExtParameterInfo, Qualifiers> {
+          Expr *, FunctionDecl *, FunctionType::ExtParameterInfo,
+          FunctionEffectSet, Qualifiers> {
   friend class ASTContext; // ASTContext creates these.
   friend TrailingObjects;
 
@@ -4226,6 +4356,9 @@ class FunctionProtoType final
   //   an ExtParameterInfo for each of the parameters. Present if and
   //   only if hasExtParameterInfos() is true.
   //
+  // * Optionally, a FunctionEffectSet. Present if and only if
+  //   hasFunctionEffects() is true.
+  //
   // * Optionally a Qualifiers object to represent extra qualifiers that can't
   //   be represented by FunctionTypeBitfields.FastTypeQuals. Present if and only
   //   if hasExtQualifiers() is true.
@@ -4284,6 +4417,7 @@ class FunctionProtoType final
     ExceptionSpecInfo ExceptionSpec;
     const ExtParameterInfo *ExtParameterInfos = nullptr;
     SourceLocation EllipsisLoc;
+    FunctionEffectSet FunctionEffects;
 
     ExtProtoInfo()
         : Variadic(false), HasTrailingReturn(false),
@@ -4301,7 +4435,8 @@ class FunctionProtoType final
 
     bool requiresFunctionProtoTypeExtraBitfields() const {
       return ExceptionSpec.Type == EST_Dynamic ||
-             requiresFunctionProtoTypeArmAttributes();
+             requiresFunctionProtoTypeArmAttributes() ||
+             FunctionEffects;
     }
 
     bool requiresFunctionProtoTypeArmAttributes() const {
@@ -4349,6 +4484,10 @@ class FunctionProtoType final
     return hasExtParameterInfos() ? getNumParams() : 0;
   }
 
+  unsigned numTrailingObjects(OverloadToken<FunctionEffectSet>) const {
+    return hasFunctionEffects();
+  }
+
   /// Determine whether there are any argument types that
   /// contain an unexpanded parameter pack.
   static bool containsAnyUnexpandedParameterPack(const QualType *ArgArray,
@@ -4450,6 +4589,7 @@ class FunctionProtoType final
     EPI.RefQualifier = getRefQualifier();
     EPI.ExtParameterInfos = getExtParameterInfosOrNull();
     EPI.AArch64SMEAttributes = getAArch64SMEAttributes();
+    EPI.FunctionEffects = getFunctionEffects();
     return EPI;
   }
 
@@ -4661,6 +4801,18 @@ class FunctionProtoType final
     return false;
   }
 
+  bool hasFunctionEffects() const {
+    if (!hasExtraBitfields())
+      return false;
+    return getTrailingObjects<FunctionTypeExtraBitfields>()->HasFunctionEffects;
+  }
+
+  FunctionEffectSet getFunctionEffects() const {
+    if (hasFunctionEffects())
+      return *getTrailingObjects<FunctionEffectSet>();
+    return {};
+  }
+
   bool isSugared() const { return false; }
   QualType desugar() const { return QualType(this, 0); }
 
@@ -7754,6 +7906,145 @@ QualType DecayedType::getPointeeType() const {
 void FixedPointValueToString(SmallVectorImpl<char> &Str, llvm::APSInt Val,
                              unsigned Scale);
 
+// ------------------------------------------------------------------------------
+
+// TODO: Should FunctionEffect be located elsewhere, where Decl is not
+// forward-declared?
+class Decl;
+class CXXMethodDecl;
+
+/// Represents an abstract function effect.
+class FunctionEffect {
+public:
+  enum EffectType {
+    kGeneric,
+    kNoLockTrue,
+    kNoAllocTrue,
+  };
+
+  /// Flags describing behaviors of the effect.
+  using Flags = unsigned;
+  enum FlagBit : unsigned {
+    // Some effects require verification, e.g. nolock(true); others might not?
+    // (no example yet)
+    kRequiresVerification = 0x1,
+
+    // Does this effect want to verify all function calls originating in
+    // functions having this effect?
+    kVerifyCalls = 0x2,
+
+    // Can verification inspect callees' implementations? (e.g. nolock: yes,
+    // tcb+types: no)
+    kInferrableOnCallees = 0x4,
+
+    // Language constructs which effects can diagnose as disallowed.
+    kExcludeThrow = 0x8,
+    kExcludeCatch = 0x10,
+    kExcludeObjCMessageSend = 0x20,
+    kExcludeStaticLocalVars = 0x40,
+    kExcludeThreadLocalVars = 0x80
+  };
+
+private:
+  const EffectType Type_;
+  const Flags Flags_;
+  const char *Name;
+
+public:
+  using CalleeDeclOrType =
+      llvm::PointerUnion<const Decl *, const FunctionProtoType *>;
+
+  FunctionEffect(EffectType T, Flags F, const char *Name)
+      : Type_{T}, Flags_{F}, Name{Name} {}
+  virtual ~FunctionEffect();
+
+  /// The type of the effect.
+  EffectType type() const { return Type_; }
+
+  /// Flags describing behaviors of the effect.
+  Flags getFlags() const { return Flags_; }
+
+  /// The description printed in diagnostics, e.g. 'nolock'.
+  StringRef name() const { return Name; }
+
+  /// The description used by TypePrinter, e.g. __attribute__((clang_nolock))
+  virtual std::string attribute() const = 0;
+
+  /// Return true if adding or removing the effect as part of a type conversion
+  /// should generate a diagnostic.
+  virtual bool diagnoseConversion(bool adding, QualType OldType,
+                                  FunctionEffectSet OldFX, QualType NewType,
+                                  FunctionEffectSet NewFX) const;
+
+  /// Return true if adding or removing the effect in a redeclaration should
+  /// generate a diagnostic.
+  virtual bool diagnoseRedeclaration(bool adding,
+                                     const FunctionDecl &OldFunction,
+                                     FunctionEffectSet OldFX,
+                                     const FunctionDecl &NewFunction,
+                                     FunctionEffectSet NewFX) const;
+
+  /// Return true if adding or removing the effect in a C++ virtual method 
+  /// override should generate a diagnostic.
+  virtual bool diagnoseMethodOverride(bool adding,
+                                      const CXXMethodDecl &OldMethod,
+                                      FunctionEffectSet OldFX,
+                                      const CXXMethodDecl &NewMethod,
+                                      FunctionEffectSet NewFX) const;
+
+  /// Return true if the effect is allowed to be inferred on the specified Decl
+  /// (may be a FunctionDecl or BlockDecl). Only used if the effect has
+  /// kInferrableOnCallees flag set. Example: This allows nolock(false) to 
+  /// prevent inference for the function.
+  virtual bool canInferOnDecl(const Decl *Caller,
+                              FunctionEffectSet CallerFX) const;
+
+  // Called if kVerifyCalls flag is set; return false for success. When true is
+  // returned for a direct call, then the kInferrableOnCallees flag may trigger
+  // inference rather than an immediate diagnostic. Caller should be assumed to
+  // have the effect (it may not have it explicitly when inferring).
+  virtual bool diagnoseFunctionCall(bool direct, const Decl *Caller,
+                                    FunctionEffectSet CallerFX,
+                                    CalleeDeclOrType Callee,
+                                    FunctionEffectSet CalleeFX) const;
+};
+
+/// FunctionEffect subclass for nolock and noalloc (whose behaviors are close
+/// to identical).
+class NoLockNoAllocEffect : public FunctionEffect {
+  bool isNoLock() const { return type() == kNoLockTrue; }
+
+public:
+  static const NoLockNoAllocEffect &nolock_instance();
+  static const NoLockNoAllocEffect &noalloc_instance();
+
+  NoLockNoAllocEffect(EffectType ty, const char *name);
+  ~NoLockNoAllocEffect() override;
+
+  std::string attribute() const override;
+
+  bool diagnoseConversion(bool adding, QualType OldType,
+                          FunctionEffectSet OldFX, QualType NewType,
+                          FunctionEffectSet NewFX) const override;
+
+  bool diagnoseRedeclaration(bool adding, const FunctionDecl &OldFunction,
+                             FunctionEffectSet OldFX,
+                             const FunctionDecl &NewFunction,
+                             FunctionEffectSet NewFX) const override;
+
+  bool diagnoseMethodOverride(bool adding, const CXXMethodDecl &OldMethod,
+                              FunctionEffectSet OldFX,
+                              const CXXMethodDecl &NewMethod,
+                              FunctionEffectSet NewFX) const override;
+
+  bool canInferOnDecl(const Decl *Caller,
+                      FunctionEffectSet CallerFX) const override;
+
+  bool diagnoseFunctionCall(bool direct, const Decl *Caller,
+                            FunctionEffectSet CallerFX, CalleeDeclOrType Callee,
+                            FunctionEffectSet CalleeFX) const override;
+};
+
 } // namespace clang
 
 #endif // LLVM_CLANG_AST_TYPE_H
diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
index 0ba172a4035fdb..1d5d8f696977e7 100644
--- a/clang/include/clang/AST/TypeProperties.td
+++ b/clang/include/clang/AST/TypeProperties.td
@@ -326,6 +326,10 @@ let Class = FunctionProtoType in {
   def : Property<"AArch64SMEAttributes", UInt32> {
     let Read = [{ node->getAArch64SMEAttributes() }];
   }
+  /* TODO: How to serialize FunctionEffect / FunctionEffectSet?
+  def : Property<"functionEffects", FunctionEffectSet> {
+    let Read = [{ node->getFunctionEffects() }];
+  }*/
 
   def : Creator<[{
     auto extInfo = FunctionType::ExtInfo(noReturn, hasRegParm, regParm,
@@ -342,6 +346,7 @@ let Class = FunctionProtoType in {
     epi.ExtParameterInfos =
       extParameterInfo.empty() ? nullptr : extParameterInfo.data();
     epi.AArch64SMEAttributes = AArch64SMEAttributes;
+    //epi.FunctionEffects = functionEffects;
     return ctx.getFunctionType(returnType, parameters, epi);
   }]>;
 }
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index fd7970d0451acd..78bbe5185741b4 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1402,6 +1402,29 @@ def CXX11NoReturn : InheritableAttr {
   let Documentation = [CXX11NoReturnDocs];
 }
 
+def NoLock : DeclOrTypeAttr {
+  let Spellings = [CXX11<"clang", "nolock">,
+                   C2x<"clang", "nolock">,
+                   GNU<"clang_nolock">];
+
+  // Subjects - not needed?
+  //let Subjects = SubjectList<[FunctionLike, Block, TypedefName], ErrorDiag>;
+  let Args = [DefaultBoolArgument<"Cond", /*default*/1>];
+  let HasCustomParsing = 0;
+  let Documentation = [NoLockNoAllocDocs];
+}
+
+def NoAlloc : DeclOrTypeAttr {
+  let Spellings = [CXX11<"clang", "noalloc">,
+                   C2x<"clang", "noalloc">,
+                   GNU<"clang_noalloc">];
+  // Subjects - not needed?
+  //let Subjects = SubjectList<[FunctionLike, Block, TypedefName], ErrorDiag>;
+  let Args = [DefaultBoolArgument<"Cond", /*default*/1>];
+  let HasCustomParsing = 0;
+  let Documentation = [NoLockNoAllocDocs];
+}
+
 // Similar to CUDA, OpenCL attributes do not receive a [[]] spelling because
 // the specification does not expose them with one currently.
 def OpenCLKernel : InheritableAttr {
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index 2c07cd09b0d5b7..bb897c708ebbea 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -7973,3 +7973,20 @@ requirement:
   }
   }];
 }
+
+def NoLockNoAllocDocs : Documentation {
+  let Category = DocCatType;
+  let Content = [{
+The ``nolock`` and ``noalloc`` attributes can be attached to functions, blocks, 
+function pointers, lambdas, and member functions. The attributes identify code
+which must not allocate memory or lock, and the compiler uses the attributes to
+verify these requirements.
+
+Like ``noexcept``, ``nolock`` and ``noalloc`` have an optional argument, a
+compile-time constant boolean expression. By default, the argument is true, so
+``[[clang::nolock(true)]]`` is equivalent to ``[[clang::nolock]]``, and declares
+the function type as never locking.
+
+TODO: how much of the RFC to include here? Make it a separate page?
+  }];
+}
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 3f14167d6b8469..0d6e9f0289f6bc 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1507,3 +1507,7 @@ def ReadOnlyPlacementChecks : DiagGroup<"read-only-types">;
 // Warnings and fixes to support the "safe buffers" programming model.
 def UnsafeBufferUsageInContainer : DiagGroup<"unsafe-buffer-usage-in-container">;
 def UnsafeBufferUsage : DiagGroup<"unsafe-buffer-usage", [UnsafeBufferUsageInContainer]>;
+
+// Warnings and notes related to the function effects system underlying
+// the nolock and noalloc attributes.
+def FunctionEffects : DiagGroup<"function-effects">;
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index c54105507753eb..5777f7dfbbcad1 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10778,6 +10778,101 @@ def warn_imp_cast_drops_unaligned : Warning<
   "implicit cast from type %0 to type %1 drops __unaligned qualifier">,
   InGroup<DiagGroup<"unaligned-qualifier-implicit-cast">>;
 
+def warn_func_effect_allocates : Warning<
+  "'%0' function '%1' must not allocate or deallocate memory">,
+  InGroup<FunctionEffects>;
+
+def note_func_effect_allocates : Note<
+  "'%1' cannot be inferred '%0' because it allocates/deallocates memory">;
+
+def warn_func_effect_throws_or_catches : Warning<
+  "'%0' function '%1' must not throw or catch exceptions">,
+  InGroup<FunctionEffects>;
+
+def note_func_effect_throws_or_catches : Note<
+  "'%1' cannot be inferred '%0' because it throws or catches exceptions">;
+
+def warn_func_effect_has_static_local : Warning<
+  "'%0' function '%1' must not have static locals">,
+  InGroup<FunctionEffects>;
+
+def note_func_effect_has_static_local : Note<
+  "'%1' cannot be inferred '%0' because it has a static local">;
+
+def warn_func_effect_uses_thread_local : Warning<
+  "'%0' function '%1' must not use thread-local variables">,
+  InGroup<FunctionEffects>;
+
+def note_func_effect_uses_thread_local : Note<
+  "'%1' cannot be inferred '%0' because it uses a thread-local variable">;
+
+def warn_func_effect_calls_objc : Warning<
+  "'%0' function '%1' must not access an ObjC method or property">,
+  InGroup<FunctionEffects>;
+
+def note_func_effect_calls_objc : Note<
+  "'%1' cannot be inferred '%0' because it accesses an ObjC method or property">;
+
+def warn_func_effect_calls_disallowed_func : Warning<
+  "'%0' function '%1' must not call non-'%0' function '%2'">,
+  InGroup<FunctionEffects>;
+
+// UNTESTED
+def warn_func_effect_calls_disallowed_expr : Warning<
+  "'%0' function '%1' must not call non-'%0' expression">,
+  InGroup<FunctionEffects>;
+
+def note_func_effect_calls_disallowed_func : Note<
+  "'%1' cannot be inferred '%0' because it calls non-'%0' function '%2'">;
+
+def note_func_effect_call_extern : Note<
+  "'%1' cannot be inferred '%0' because it has no definition in this translation unit">;
+
+def note_func_effect_call_not_inferrable : Note<
+  "'%1' does not permit inference of '%0'">;
+
+def note_func_effect_call_virtual : Note<
+  "'%1' cannot be inferred '%0' because it is virtual">;
+
+def note_func_effect_call_func_ptr : Note<
+  "'%1' cannot be inferred '%0' because it is a function pointer">;
+
+// TODO: Not currently being generated
+def warn_perf_annotation_implies_noexcept : Warning<
+  "'%0' function should be declared noexcept">,
+  InGroup<PerfAnnotationImpliesNoexcept>;
+
+// TODO: Not currently being generated
+def warn_func_effect_false_on_type : Warning<
+  "only functions/methods/blocks may be declared %0(false)">,
+  InGroup<FunctionEffects>;
+
+// TODO: can the usual template expansion notes be used?
+def note_func_effect_from_template : Note<
+  "in template expansion here">;
+
+// TODO: Needs to be tested
+def warn_incompatible_func_effects : Warning<
+  "attributes '%0' and '%1' are incompatible">,
+  InGroup<FunctionEffects>;
+
+// spoofing nolock/noalloc
+def warn_invalid_add_func_effects : Warning<
+  "attribute '%0' should not be added via type conversion">,
+  InGroup<FunctionEffects>;
+
+def warn_invalid_remove_func_effects : Warning<
+  "attribute '%0' should not be removed via type conversion">,
+  InGroup<FunctionEffects>;
+
+def warn_mismatched_func_effect_override : Warning<
+  "attribute '%0' on overriding function does not match base version">,
+  InGroup<FunctionEffects>;
+
+def warn_mismatched_func_effect_redeclaration : Warning<
+  "attribute '%0' on function does not match previous declaration">,
+  InGroup<FunctionEffects>;
+
 } // end of sema category
 
 let CategoryName = "API Notes Issue" in {
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 267c79cc057cba..2772f882a5c09d 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -721,6 +721,12 @@ class Sema final {
   /// Load weak undeclared identifiers from the external source.
   void LoadExternalWeakUndeclaredIdentifiers();
 
+  /// All functions/lambdas/blocks which have bodies and which have a non-empty
+  /// FunctionEffectSet to be verified.
+  SmallVector<const Decl *> DeclsWithUnverifiedEffects;
+  /// The union of all effects present on DeclsWithUnverifiedEffects.
+  MutableFunctionEffectSet AllEffectsToVerify;
+
   /// Determine if VD, which must be a variable or function, is an external
   /// symbol that nonetheless can't be referenced from outside this translation
   /// unit because its type has no linkage and it's not extern "C".
@@ -940,6 +946,10 @@ class Sema final {
   /// Warn when implicitly casting 0 to nullptr.
   void diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E);
 
+  /// Warn when implicitly changing function effects.
+  void diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
+                                        SourceLocation Loc);
+
   bool makeUnavailableInSystemHeader(SourceLocation loc,
                                      UnavailableAttr::ImplicitReason reason);
 
@@ -3132,6 +3142,9 @@ class Sema final {
                               QualType T, TypeSourceInfo *TSInfo,
                               StorageClass SC);
 
+  /// Potentially add a FunctionDecl or BlockDecl to DeclsWithUnverifiedEffects.
+  void CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX);
+
   // Contexts where using non-trivial C union types can be disallowed. This is
   // passed to err_non_trivial_c_union_in_invalid_context.
   enum NonTrivialCUnionContext {
@@ -3739,6 +3752,9 @@ class Sema final {
                                       StringRef &Str,
                                       SourceLocation *ArgLocation = nullptr);
 
+  bool checkBoolExprArgumentAttr(const ParsedAttr &Attr, unsigned ArgNum,
+                                 bool &Value);
+
   /// Determine if type T is a valid subject for a nonnull and similar
   /// attributes. By default, we look through references (the behavior used by
   /// nonnull), but if the second parameter is true, then we treat a reference
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 5a8fae76a43a4d..43fccb117a897d 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -4502,11 +4502,13 @@ QualType ASTContext::getFunctionTypeInternal(
   size_t Size = FunctionProtoType::totalSizeToAlloc<
       QualType, SourceLocation, FunctionType::FunctionTypeExtraBitfields,
       FunctionType::FunctionTypeArmAttributes, FunctionType::ExceptionType,
-      Expr *, FunctionDecl *, FunctionProtoType::ExtParameterInfo, Qualifiers>(
+      Expr *, FunctionDecl *, FunctionProtoType::ExtParameterInfo, 
+      FunctionEffectSet, Qualifiers>(
       NumArgs, EPI.Variadic, EPI.requiresFunctionProtoTypeExtraBitfields(),
       EPI.requiresFunctionProtoTypeArmAttributes(), ESH.NumExceptionType,
       ESH.NumExprPtr, ESH.NumFunctionDeclPtr,
       EPI.ExtParameterInfos ? NumArgs : 0,
+      EPI.FunctionEffects ? 1 : 0,
       EPI.TypeQuals.hasNonFastQualifiers() ? 1 : 0);
 
   auto *FTP = (FunctionProtoType *)Allocate(Size, alignof(FunctionProtoType));
@@ -10435,6 +10437,15 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
     allRTypes = false;
 
   FunctionType::ExtInfo einfo = lbaseInfo.withNoReturn(NoReturn);
+  FunctionEffectSet FromFX, ToFX;
+  std::optional<FunctionEffectSet> MergedFX;
+
+  if (lproto) ToFX = lproto->getFunctionEffects();
+  if (rproto) FromFX = rproto->getFunctionEffects();
+  if (ToFX != FromFX) {
+    // We want the intersection of the effects...
+    MergedFX = FunctionEffectSet::create(FromFX & ToFX);
+  }
 
   if (lproto && rproto) { // two C99 style function prototypes
     assert((AllowCXX ||
@@ -10487,13 +10498,18 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
         allRTypes = false;
     }
 
-    if (allLTypes) return lhs;
-    if (allRTypes) return rhs;
+    if (!MergedFX) { // effects changed so we can't return either side unaltered
+      if (allLTypes) return lhs;
+      if (allRTypes) return rhs;
+    }
 
     FunctionProtoType::ExtProtoInfo EPI = lproto->getExtProtoInfo();
     EPI.ExtInfo = einfo;
     EPI.ExtParameterInfos =
         newParamInfos.empty() ? nullptr : newParamInfos.data();
+    if (MergedFX) {
+      EPI.FunctionEffects = *MergedFX;
+    }
     return getFunctionType(retType, types, EPI);
   }
 
@@ -10526,11 +10542,16 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
         return {};
     }
 
-    if (allLTypes) return lhs;
-    if (allRTypes) return rhs;
+    if (!MergedFX) { // effects changed so we can't return either side unaltered
+      if (allLTypes) return lhs;
+      if (allRTypes) return rhs;
+    }
 
     FunctionProtoType::ExtProtoInfo EPI = proto->getExtProtoInfo();
     EPI.ExtInfo = einfo;
+    if (MergedFX) {
+      EPI.FunctionEffects = *MergedFX;
+    }
     return getFunctionType(retType, proto->getParamTypes(), EPI);
   }
 
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 8626f04012f7d4..596f4ea2e67176 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -3517,6 +3517,61 @@ bool FunctionDecl::isMemberLikeConstrainedFriend() const {
   return FriendConstraintRefersToEnclosingTemplate();
 }
 
+static void examine(const Decl& D)
+{
+  PrintingPolicy PP = D.getASTContext().getPrintingPolicy();
+  PP.TerseOutput = 1;
+  D.print(llvm::outs(), PP);
+}
+
+#if TEMP_DISABLE
+// This constant controls the default policy.
+constexpr static bool kDefaultCanInferPerfAnnotation = true;
+
+static bool declCanInferPerfAnnotation(const Decl &D, QualType QT) {
+  // llvm::outs() << "declCanInferPerfAnnotation " << &D << "\n";
+  // examine(D);
+
+  // nolock(false) or noalloc(false) disables inference.
+  if (QT->disallowPerfAnnotationInference()) {
+    // llvm::outs() << "  disallowed by QT\n";
+    return false;
+  }
+  if (auto *IA = D.getAttr<PerformanceInferredAttr>()) {
+    // llvm::outs() << "  decl has attr " << IA->getCanInfer() << "\n";
+    return IA->getCanInfer();
+  }
+  if (auto *Method = dyn_cast<CXXMethodDecl>(&D)) {
+    auto *Class = Method->getParent();
+    if (auto *IA = Class->getAttr<PerformanceInferredAttr>()) {
+      // llvm::outs() << "  class has attr " << IA->getCanInfer() << "\n";
+      return IA->getCanInfer();
+    }
+  }
+
+  // for (const DeclContext *DC = D.getDeclContext(); DC != nullptr; DC = DC->getParent()) {
+  //   if (auto *Decl2 = dyn_cast<Decl>(DC)) {
+  //     examine(*Decl2);
+  //     if (auto *IA = Decl2->getAttr<PerformanceInferredAttr>()) {
+  //       llvm::outs() << "  decl2 has attr " << IA->getCanInfer() << "\n";
+  //       return IA->getCanInfer();
+  //     }
+  //   }
+  // }
+
+  // llvm::outs() << "  result: false\n";
+  return kDefaultCanInferPerfAnnotation;
+}
+
+PerfAnnotation FunctionDecl::getPerfAnnotation() const {
+  return getType()->getPerfAnnotation();
+}
+
+bool FunctionDecl::canInferPerfAnnotation() const {
+  return declCanInferPerfAnnotation(*this, getType());
+}
+#endif // TEMP_DISABLE
+
 MultiVersionKind FunctionDecl::getMultiVersionKind() const {
   if (hasAttr<TargetAttr>())
     return MultiVersionKind::Target;
@@ -5226,6 +5281,36 @@ SourceRange BlockDecl::getSourceRange() const {
   return SourceRange(getLocation(), Body ? Body->getEndLoc() : getLocation());
 }
 
+FunctionEffectSet BlockDecl::getFunctionEffects() const {
+  if (auto* TSI = getSignatureAsWritten()) {
+    if (auto* FPT = TSI->getType()->getAs<FunctionProtoType>()) {
+      return FPT->getFunctionEffects();
+    }
+  }
+  return {};
+}
+
+#if TEMP_DISABLE
+PerfAnnotation BlockDecl::getPerfAnnotation() const
+{
+  if (auto* TSI = getSignatureAsWritten()) {
+    return TSI->getType()->getPerfAnnotation();
+  }
+  return PerfAnnotation::None;
+}
+#endif // TEMP_DISABLE
+
+#if 0
+// unused
+bool BlockDecl::canInferPerfAnnotation() const
+{
+  if (auto* TSI = getSignatureAsWritten()) {
+    return declCanInferPerfAnnotation(*this, TSI->getType());
+  }
+  return kDefaultCanInferPerfAnnotation;
+}
+#endif
+
 //===----------------------------------------------------------------------===//
 // Other Decl Allocation/Deallocation Method Implementations
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 22666184c56ccf..ce209be2c3a079 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3583,6 +3583,13 @@ FunctionProtoType::FunctionProtoType(QualType result, ArrayRef<QualType> params,
     auto &EllipsisLoc = *getTrailingObjects<SourceLocation>();
     EllipsisLoc = epi.EllipsisLoc;
   }
+
+  if (epi.FunctionEffects) {
+    auto &ExtraBits = *getTrailingObjects<FunctionTypeExtraBitfields>();
+    ExtraBits.HasFunctionEffects = true;
+
+    *getTrailingObjects<FunctionEffectSet>() = epi.FunctionEffects;
+  }
 }
 
 bool FunctionProtoType::hasDependentExceptionSpec() const {
@@ -3666,11 +3673,14 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   // Finally we have a trailing return type flag (bool)
   // combined with AArch64 SME Attributes, to save space:
   //      int
+  // Then add the FunctionEffects
   //
   // There is no ambiguity between the consumed arguments and an empty EH
   // spec because of the leading 'bool' which unambiguously indicates
   // whether the following bool is the EH spec or part of the arguments.
 
+  ID.AddPointer(epi.FunctionEffects.getOpaqueValue()); // TODO: Where???
+
   ID.AddPointer(Result.getAsOpaquePtr());
   for (unsigned i = 0; i != NumParams; ++i)
     ID.AddPointer(ArgTys[i].getAsOpaquePtr());
@@ -3684,6 +3694,7 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   ID.AddInteger(unsigned(epi.Variadic) +
                 (epi.RefQualifier << 1) +
                 (epi.ExceptionSpec.Type << 3));
+
   ID.Add(epi.TypeQuals);
   if (epi.ExceptionSpec.Type == EST_Dynamic) {
     for (QualType Ex : epi.ExceptionSpec.Exceptions)
@@ -4912,3 +4923,267 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
   Profile(ID, Context, getDeducedType(), getKeyword(), isDependentType(),
           getTypeConstraintConcept(), getTypeConstraintArguments());
 }
+
+
+FunctionEffect::~FunctionEffect() = default;
+
+bool FunctionEffect::diagnoseConversion(bool adding, QualType OldType, FunctionEffectSet OldFX,
+    QualType NewType, FunctionEffectSet NewFX) const
+{
+  return false;
+}
+
+bool FunctionEffect::diagnoseRedeclaration(bool adding,
+    const FunctionDecl& OldFunction, FunctionEffectSet OldFX,
+    const FunctionDecl& NewFunction, FunctionEffectSet NewFX) const { return false; }
+
+bool FunctionEffect::diagnoseMethodOverride(bool adding,
+    const CXXMethodDecl& OldMethod, FunctionEffectSet OldFX,
+    const CXXMethodDecl& NewMethod, FunctionEffectSet NewFX) const { return false; }
+
+bool FunctionEffect::canInferOnDecl(const Decl* Caller, FunctionEffectSet CallerFX) const
+{
+  return false;
+}
+
+bool FunctionEffect::diagnoseFunctionCall(bool direct, 
+    const Decl* Caller, FunctionEffectSet CallerFX,
+    CalleeDeclOrType Callee, FunctionEffectSet CalleeFX) const
+{
+  return false;
+}
+
+const NoLockNoAllocEffect& NoLockNoAllocEffect::nolock_instance()
+{
+  static NoLockNoAllocEffect global(kNoLockTrue, "nolock");
+  return global;
+}
+
+const NoLockNoAllocEffect& NoLockNoAllocEffect::noalloc_instance()
+{
+  static NoLockNoAllocEffect global(kNoAllocTrue, "noalloc");
+  return global;
+}
+
+// TODO: Separate flags for noalloc
+NoLockNoAllocEffect::NoLockNoAllocEffect(EffectType ty, const char* name)
+  : FunctionEffect{ ty, kRequiresVerification | kVerifyCalls | kInferrableOnCallees | kExcludeThrow | kExcludeCatch
+    | kExcludeObjCMessageSend | kExcludeStaticLocalVars | kExcludeThreadLocalVars, name }
+{
+}
+
+NoLockNoAllocEffect::~NoLockNoAllocEffect() = default;
+
+std::string NoLockNoAllocEffect::attribute() const
+{
+  return std::string{ "__attribute__((clang_" } + name().str() + "))";
+}
+
+bool NoLockNoAllocEffect::diagnoseConversion(bool adding, QualType OldType, FunctionEffectSet OldFX,
+    QualType NewType, FunctionEffectSet NewFX) const
+{
+  // noalloc can't be added (spoofed) during a conversion, unless we have nolock
+  if (adding) {
+    if (!isNoLock()) {
+      for (const auto* effect : OldFX) {
+        if (effect->type() == kNoLockTrue)
+          return false;
+      }
+    }
+    // nolock can't be added (spoofed) during a conversion.
+    return true;
+  }
+  return false;
+}
+
+bool NoLockNoAllocEffect::diagnoseRedeclaration(bool adding,
+  const FunctionDecl& OldFunction, FunctionEffectSet OldFX,
+  const FunctionDecl& NewFunction, FunctionEffectSet NewFX) const
+{
+  // nolock/noalloc can't be removed in a redeclaration
+  // adding -> false, removing -> true (diagnose)
+  return !adding;
+}
+
+bool NoLockNoAllocEffect::diagnoseMethodOverride(bool adding,
+  const CXXMethodDecl& OldMethod, FunctionEffectSet OldFX,
+  const CXXMethodDecl& NewMethod, FunctionEffectSet NewFX) const
+{
+  // nolock/noalloc can't be removed from an override
+  return !adding;
+}
+
+bool NoLockNoAllocEffect::canInferOnDecl(const Decl* Caller, FunctionEffectSet CallerFX) const
+{
+  // Does the Decl have nolock(false) / noalloc(false) ?
+  QualType QT;
+  if (isa<BlockDecl>(Caller)) {
+    const auto* TSI = cast<BlockDecl>(Caller)->getSignatureAsWritten();
+    QT = TSI->getType();
+  } else if (isa<ValueDecl>(Caller)) {
+    QT = cast<ValueDecl>(Caller)->getType();
+  } else {
+    return false;
+  }
+  if (QT->hasAttr(isNoLock() ? attr::Kind::NoLock : attr::Kind::NoAlloc)) {
+    return false;
+  }
+
+  return true;
+}
+
+bool NoLockNoAllocEffect::diagnoseFunctionCall(bool direct, 
+    const Decl* Caller, FunctionEffectSet CallerFX,
+    CalleeDeclOrType Callee, FunctionEffectSet CalleeFX) const
+{
+  const EffectType callerType = type();
+  for (const auto* effect : CalleeFX) {
+    const EffectType ty = effect->type();
+    if (ty == callerType || (callerType == kNoAllocTrue && ty == kNoLockTrue)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+// =====
+
+void MutableFunctionEffectSet::insert(const FunctionEffect* effect)
+{
+  auto iter = std::lower_bound(begin(), end(), effect);
+  if (*iter != effect) {
+    insert(iter, effect);
+  }
+}
+
+MutableFunctionEffectSet& MutableFunctionEffectSet::operator|=(FunctionEffectSet rhs)
+{
+  // TODO: For large rhs sets, use set_union or a custom insert-in-place
+  for (const auto* effect : rhs) {
+    insert(effect);
+  }
+  return *this;
+}
+
+// This could be simpler if there were a simple set container that could be queried by
+// ArrayRef but which stored something else. Possibly a DenseMap with void values?
+FunctionEffectSet FunctionEffectSet::create(llvm::ArrayRef<const FunctionEffect*> items)
+{
+  if (items.empty()) {
+    return FunctionEffectSet{};
+  }
+  if (items.size() == 1) {
+    return FunctionEffectSet{ items[0] };
+  }
+
+  UniquedAndSortedFX newSet{ items }; // just copies the ArrayRef
+
+  // SmallSet only has contains(), so it provides no way to obtain the uniqued value.
+  static std::set<UniquedAndSortedFX> uniquedFXSets;
+
+  // See if we already have this set.
+  const auto iter = uniquedFXSets.find(newSet);
+  if (iter != uniquedFXSets.end()) {
+    return FunctionEffectSet{ &*iter };
+  }
+
+  // Copy the incoming array to permanent storage.
+  auto* storage = new const FunctionEffect*[items.size()];
+  std::copy(items.begin(), items.end(), storage);
+
+  // Make a new wrapper and insert it into the set.
+  newSet = UniquedAndSortedFX{ storage, items.size() };
+  auto [insiter, good] = uniquedFXSets.insert(newSet);
+  return FunctionEffectSet{ &*insiter };
+}
+
+FunctionEffectSet FunctionEffectSet::operator|(const FunctionEffectSet& rhs) const
+{
+  const FunctionEffectSet& lhs = *this;
+  if (lhs.empty()) {
+    return rhs;
+  }
+  if (rhs.empty()) {
+    return lhs;
+  }
+  // Optimize the case where the two sets are identical
+  if (lhs == rhs) {
+    return lhs;
+  }
+
+  MutableFunctionEffectSet vec;
+  vec.reserve(lhs.size() + rhs.size());
+  std::set_union(lhs.begin(), lhs.end(), rhs.begin(), rhs.end(), std::back_inserter(vec));
+  // The result of a set operation is an ordered/unique set.
+  return FunctionEffectSet::create(vec);
+}
+
+MutableFunctionEffectSet FunctionEffectSet::operator&(const FunctionEffectSet& rhs) const
+{
+  const FunctionEffectSet& lhs = *this;
+  if (lhs.empty() || rhs.empty()) {
+    return {};
+  }
+
+  MutableFunctionEffectSet vec;
+  std::set_intersection(lhs.begin(), lhs.end(), rhs.begin(), rhs.end(), std::back_inserter(vec));
+  // The result of a set operation is an ordered/unique set.
+  return vec;
+}
+
+// TODO: inline?
+FunctionEffectSet FunctionEffectSet::get(const Type& TyRef)
+{
+  const Type* Ty = &TyRef;      
+  if (Ty->isPointerType())
+    Ty = Ty->getPointeeType().getTypePtr();
+  if (const auto* FPT = Ty->getAs<FunctionProtoType>())
+    return FPT->getFunctionEffects();
+  return {};
+}
+
+FunctionEffectSet::Differences FunctionEffectSet::differences(
+    const FunctionEffectSet& Old, const FunctionEffectSet& New)
+{
+  // TODO: Could be a one-pass algorithm.
+  Differences result;
+  for (const auto* effect : (New - Old)) {
+    result.emplace_back(effect, true);
+  }
+  for (const auto* effect : (Old - New)) {
+    result.emplace_back(effect, false);
+  }
+  return result;
+}
+
+MutableFunctionEffectSet FunctionEffectSet::operator-(const FunctionEffectSet& rhs) const
+{
+  const FunctionEffectSet& lhs = *this;
+  MutableFunctionEffectSet result;
+
+  std::set_difference(lhs.begin(), lhs.end(), rhs.begin(), rhs.end(), std::back_inserter(result));
+  return result;
+}
+
+bool FunctionEffectSet::operator<(const FunctionEffectSet& rhs) const
+{
+  const FunctionEffectSet& lhs = *this;
+  return std::lexicographical_compare(lhs.begin(), lhs.end(), rhs.begin(), rhs.end());
+}
+
+bool FunctionEffectSet::UniquedAndSortedFX::operator<(const UniquedAndSortedFX& rhs) const
+{
+  return this < &rhs;
+}
+
+void FunctionEffectSet::dump(llvm::raw_ostream &OS) const
+{
+  OS << "FX{";
+  bool first = true;
+  for (const auto* effect : *this) {
+    if (!first) OS << ", ";
+    else first = false;
+    OS << effect->name();
+  }
+  OS << "}";
+}
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 7dcc4348f8e036..560f2faeb9e503 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -984,8 +984,15 @@ void TypePrinter::printFunctionProtoAfter(const FunctionProtoType *T,
     OS << " &&";
     break;
   }
+
   T->printExceptionSpecification(OS, Policy);
 
+  if (auto effects = T->getFunctionEffects()) {
+    for (const auto* effect : effects) {
+      OS << " " << effect->attribute();
+    }
+  }
+
   if (T->hasTrailingReturn()) {
     OS << " -> ";
     print(T->getReturnType(), OS, StringRef());
@@ -1904,6 +1911,7 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   case attr::AArch64SVEPcs: OS << "aarch64_sve_pcs"; break;
   case attr::AMDGPUKernelCall: OS << "amdgpu_kernel"; break;
   case attr::IntelOclBicc: OS << "inteloclbicc"; break;
+
   case attr::PreserveMost:
     OS << "preserve_most";
     break;
@@ -1930,6 +1938,12 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   // Nothing to print for this attribute.
   case attr::HLSLParamModifier:
     break;
+  case attr::NoLock:
+    OS << "clang_nolock(false)";
+    break;
+  case attr::NoAlloc:
+    OS << "clang_noalloc(false)";
+    break;
   }
   OS << "))";
 }
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 6992ba9ad9a756..a0d813fa4d3d14 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2380,6 +2380,1494 @@ class UnsafeBufferUsageReporter : public UnsafeBufferUsageHandler {
 };
 } // namespace
 
+// =============================================================================
+
+#define FX_ANALYZER_VERIFY_DECL_LIST 1
+
+namespace FXAnalysis {
+
+enum class DiagnosticID : uint8_t {
+  None = 0, // sentinel for an empty Diagnostic
+  Throws,
+  Catches,
+  CallsObjC,
+  AllocatesMemory,
+  HasStaticLocal,
+  AccessesThreadLocal,
+
+  // These only apply to callees, where the analysis stops at the Decl
+  // DeclExternWithoutConstraint, // TODO: not used?
+  DeclWithoutConstraintOrInference,
+  //DeclVirtualWithoutConstraint,
+  //DeclFuncPtrWithoutConstraint,
+
+  CallsUnsafeDecl,
+  CallsDisallowedExpr,
+};
+
+struct Diagnostic {
+  const FunctionEffect* Effect = nullptr;
+  const Decl* Callee = nullptr; // only valid for Calls*
+  SourceLocation Loc{};
+  DiagnosticID ID{ DiagnosticID::None };
+
+  Diagnostic() = default;
+
+  Diagnostic(const FunctionEffect *Effect, DiagnosticID ID, SourceLocation Loc, const Decl* Callee = nullptr)
+    : Effect{ Effect }, Callee{ Callee }, Loc{ Loc }, ID{ ID }
+  {
+  }
+};
+
+enum class SpecialFuncType : uint8_t {
+  None, OperatorNew, OperatorDelete
+};
+enum class CallType {
+  Unknown, Function, Virtual, Block
+  // unknown: probably function pointer
+};
+
+// Return whether the function CAN be verified.
+// The question of whether it SHOULD be verified is independent.
+static bool functionIsVerifiable(const FunctionDecl* FD)
+{
+  if (!(FD->hasBody() || FD->isInlined())) {
+    // externally defined; we couldn't verify if we wanted to.
+    return false;
+  }
+  if (FD->isTrivial()) {
+    // Otherwise `struct x { int a; };` would have an unverifiable default
+    // constructor.
+    return true;
+  }
+  return true;
+}
+
+// Transitory, more extended information about a callable, which can be a function,
+// block, function pointer...
+struct CallableInfo {
+  const Decl* CDecl;
+  mutable std::optional<std::string> MaybeName; // mutable because built on demand in const method
+  SpecialFuncType FuncType{ SpecialFuncType::None };
+  FunctionEffectSet Effects;
+  CallType CType{ CallType::Unknown };
+  // bool IsAllowListed{ false };
+
+  CallableInfo(const Decl& CD, SpecialFuncType FT = SpecialFuncType::None)
+    : CDecl{ &CD }, FuncType{ FT }
+  {
+    //llvm::errs() << "CallableInfo " << name() << "\n";
+
+    if (auto* FD = dyn_cast<FunctionDecl>(CDecl)) {
+      assert(FD->getCanonicalDecl() == FD);
+      // Use the function's definition, if any.
+      if (auto* Def = FD->getDefinition()) {
+        CDecl = FD = Def;
+      }
+      CType = CallType::Function;
+      if (auto* Method = dyn_cast<CXXMethodDecl>(FD)) {
+        if (Method->isVirtual()) {
+          CType = CallType::Virtual;
+        }
+      }
+      Effects = FD->getFunctionEffects();
+
+      // TODO: Generalize via noreturn??? but that would cover exceptions too.
+      // if (name() == "__assert_rtn") {
+      //   // big hack because it's hard to get the attribute to stick on it
+      //   // through a redeclaration, not sure why.
+      //   IsAllowListed = true;
+      // }
+    } else if (auto* BD = dyn_cast<BlockDecl>(CDecl)) {
+      CType = CallType::Block;
+      Effects = BD->getFunctionEffects();
+    } else if (auto* VD = dyn_cast<ValueDecl>(CDecl)) {
+      // ValueDecl is function, enum, or variable, so just look at the type.
+      Effects = FunctionEffectSet::get(*VD->getType());
+    }
+  }
+
+  bool isDirectCall() const {
+    return CType == CallType::Function || CType == CallType::Block;
+  }
+
+  bool isVerifiable() const
+  {
+    switch (CType) {
+    case CallType::Unknown:
+    case CallType::Virtual:
+      break;
+    case CallType::Block:
+      return true;
+    case CallType::Function:
+      return functionIsVerifiable(dyn_cast<FunctionDecl>(CDecl));
+    }
+    return false;
+  }
+
+  /// Generate a name for logging.
+  std::string name(Sema& sema) const
+  {
+    if (!MaybeName) {
+      std::string Name;
+      llvm::raw_string_ostream OS(Name);
+
+      if (auto* FD = dyn_cast<FunctionDecl>(CDecl)) {
+        FD->getNameForDiagnostic(OS, sema.getPrintingPolicy(),
+                                    /*Qualified=*/true);
+      } else if (auto* BD = dyn_cast<BlockDecl>(CDecl)) {
+        OS << "(block " << BD->getBlockManglingNumber() << ")";
+      } else if (auto* VD = dyn_cast<NamedDecl>(CDecl)) {
+        VD->printQualifiedName(OS);
+      }
+      MaybeName = Name;
+    }
+    return *MaybeName;
+  }
+};
+
+// ----------
+// Map effects to single diagnostics.
+class EffectToDiagnosticMap {
+  // Since we currently only have a tiny number of effects (typically no more than 1),
+  // use a sorted SmallVector.
+  using Element = std::pair<const FunctionEffect*, Diagnostic>;
+  using ImplVec = llvm::SmallVector<Element>;
+  std::unique_ptr<ImplVec> Impl;
+public:
+  Diagnostic& getOrInsertDefault(const FunctionEffect* key)
+  {
+    if (Impl == nullptr) {
+      Impl = std::make_unique<llvm::SmallVector<Element>>();
+      auto& item = Impl->emplace_back();
+      item.first = key;
+      return item.second;
+    }
+    Element elem{ key, {} };
+    auto iter = _find(elem);
+    if (iter != Impl->end() && iter->first == key) {
+      return iter->second;
+    }
+    iter = Impl->insert(iter, elem);
+    return iter->second;
+  }
+
+  const Diagnostic* lookup(const FunctionEffect* key)
+  {
+    if (Impl == nullptr) {
+      return nullptr;
+    }
+    Element elem{ key, {} };
+    auto iter = _find(elem);
+    if (iter != Impl->end() && iter->first == key) {
+      return &iter->second;
+    }
+    return nullptr;
+  }
+
+  size_t size() const { return Impl ? Impl->size() : 0; }
+
+private:
+  ImplVec::iterator _find(const Element& elem)
+  {
+    return std::lower_bound(Impl->begin(), Impl->end(), elem, [](const Element& lhs, const Element& rhs) {
+      return lhs.first < rhs.first;
+    });
+  }
+};
+
+// ----------
+// State pertaining to a function whose AST is walked. Since there are potentially a large
+// number of these objects, it needs care about size.
+class PendingFunctionAnalysis {
+  // Current size: 5 pointers
+  friend class CompleteFunctionAnalysis;
+
+  struct DirectCall {
+    const Decl* Callee;
+    SourceLocation CallLoc;
+  };
+
+public:
+  // We always have two disjoint sets of effects to verify:
+  // 1. Effects declared explicitly by this function.
+  // 2. All other inferrable effects needing verification.
+  FunctionEffectSet DeclaredVerifiableEffects;
+  FunctionEffectSet FXToInfer;
+
+private:
+  // Diagnostics pertaining to the function's explicit effects. Use a unique_ptr to optimize
+  // size for the case of 0 diagnostics.
+  std::unique_ptr<SmallVector<Diagnostic>> DiagnosticsForExplicitFX;
+
+  // Potential diagnostics pertaining to other, non-explicit, inferrable effects.
+  EffectToDiagnosticMap InferrableEffectToFirstDiagnostic;
+
+  std::unique_ptr<SmallVector<DirectCall>> UnverifiedDirectCalls;
+
+public:
+  PendingFunctionAnalysis(const CallableInfo& cinfo, FunctionEffectSet AllInferrableEffectsToVerify)
+  {
+    MutableFunctionEffectSet fx;
+    for (const auto* effect : cinfo.Effects) {
+      if (effect->getFlags() & FunctionEffect::kRequiresVerification) {
+        fx.insert(effect);
+      }
+    }
+    DeclaredVerifiableEffects = FunctionEffectSet::create(fx);
+
+    // Check for effects we are not allowed to infer
+    fx.clear();
+    for (const auto* effect : AllInferrableEffectsToVerify) {
+      if (effect->canInferOnDecl(cinfo.CDecl, cinfo.Effects)) {
+        fx.insert(effect);
+      } else {
+        // Add a diagnostic for this effect if a caller were to
+        // try to infer it.
+        auto& diag = InferrableEffectToFirstDiagnostic.getOrInsertDefault(effect);
+        diag = Diagnostic{ effect, DiagnosticID::DeclWithoutConstraintOrInference,
+          cinfo.CDecl->getLocation() };
+      }
+    }
+    // fx is now the set of inferrable effects which are not prohibited
+    FXToInfer = FunctionEffectSet::create(FunctionEffectSet::create(fx) - DeclaredVerifiableEffects);
+  }
+
+  void checkAddDiagnostic(bool inferring, const Diagnostic& NewDiag)
+  {
+    if (!inferring) {
+      if (DiagnosticsForExplicitFX == nullptr) {
+        DiagnosticsForExplicitFX = std::make_unique<SmallVector<Diagnostic>>();
+      }
+      DiagnosticsForExplicitFX->push_back(NewDiag);
+    } else {
+      auto& diag = InferrableEffectToFirstDiagnostic.getOrInsertDefault(NewDiag.Effect);
+      if (diag.ID == DiagnosticID::None) {
+        diag = NewDiag;
+      }
+    }
+  }
+
+  void addUnverifiedDirectCall(const Decl* D, SourceLocation CallLoc)
+  {
+    if (UnverifiedDirectCalls == nullptr) {
+      UnverifiedDirectCalls = std::make_unique<SmallVector<DirectCall>>();
+    }
+    UnverifiedDirectCalls->emplace_back(DirectCall{ D, CallLoc });
+  }
+
+  // Analysis is complete when there are no unverified direct calls.
+  bool isComplete() const
+  {
+    return UnverifiedDirectCalls == nullptr || UnverifiedDirectCalls->empty();
+  }
+
+  const Diagnostic* diagnosticForInferrableEffect(const FunctionEffect* effect)
+  {
+    return InferrableEffectToFirstDiagnostic.lookup(effect);
+  }
+
+  const SmallVector<DirectCall>& unverifiedCalls() const
+  {
+    assert(!isComplete());
+    return *UnverifiedDirectCalls;
+  }
+
+  SmallVector<Diagnostic>* getDiagnosticsForExplicitFX() const
+  {
+    return DiagnosticsForExplicitFX.get();
+  }
+
+  void dump(llvm::raw_ostream& OS) const
+  {
+    OS << "Pending: Declared ";
+    DeclaredVerifiableEffects.dump(OS);
+    OS << ", " << (DiagnosticsForExplicitFX ? DiagnosticsForExplicitFX->size() : 0) << " diags; ";
+    OS << " Infer ";
+    FXToInfer.dump(OS);
+    OS << ", " << InferrableEffectToFirstDiagnostic.size() << " diags\n";
+  }
+};
+
+// ----------
+class CompleteFunctionAnalysis {
+  // Current size: 2 pointers
+public:
+  // Has effects which are both the declared ones -- not to be inferred -- plus ones which
+  // have been successfully inferred. These are all considered "verified" for the purposes
+  // of callers; any issue with verifying declared effects has already been reported and
+  // is not the problem of any caller.
+  FunctionEffectSet VerifiedEffects;
+
+private:
+  // This is used to generate notes about failed inference.
+  EffectToDiagnosticMap InferrableEffectToFirstDiagnostic;
+
+public:
+  CompleteFunctionAnalysis(PendingFunctionAnalysis& pending, FunctionEffectSet funcFX, FunctionEffectSet AllInferrableEffectsToVerify)
+  {
+    MutableFunctionEffectSet verified;
+    verified |= funcFX;
+    for (const auto* effect : AllInferrableEffectsToVerify) {
+      if (pending.diagnosticForInferrableEffect(effect) == nullptr) {
+        verified.insert(effect);
+      }
+    }
+    VerifiedEffects = FunctionEffectSet::create(verified);
+
+    InferrableEffectToFirstDiagnostic = std::move(pending.InferrableEffectToFirstDiagnostic);
+  }
+
+  const Diagnostic* firstDiagnosticForEffect(const FunctionEffect* effect)
+  {
+    // TODO: is this correct?
+    return InferrableEffectToFirstDiagnostic.lookup(effect);
+  }
+
+  void dump(llvm::raw_ostream& OS) const
+  {
+    OS << "Complete: Verified ";
+    VerifiedEffects.dump(OS);
+    OS << "; Infer ";
+    OS << InferrableEffectToFirstDiagnostic.size() << " diags\n";
+  }
+};
+
+/*
+	TODO: nolock and noalloc imply noexcept
+        if (auto* Method = dyn_cast<CXXMethodDecl>(CInfo.CDecl)) {
+          if (Method->getType()->castAs<FunctionProtoType>()->canThrow()
+              != clang::CT_Cannot) {
+            S.Diag(Callable->getBeginLoc(), 
+              diag::warn_perf_annotation_implies_noexcept)
+              << getPerfAnnotationSpelling(CInfo.PerfAnnot);
+          }
+        }
+*/
+
+// ==========
+class Analyzer {
+  constexpr static int kDebugLogLevel = 3;
+
+  // --
+  Sema& mSema;
+
+  // used from Sema:
+  //  SmallVector<const Decl *> DeclsWithUnverifiedEffects
+
+  // Subset of Sema.AllEffectsToVerify
+  FunctionEffectSet AllInferrableEffectsToVerify;
+
+  using FuncAnalysisPtr = llvm::PointerUnion<PendingFunctionAnalysis*, CompleteFunctionAnalysis*>;
+
+  // Map all Decls analyzed to FuncAnalysisPtr. Pending state is larger 
+  // than complete state, so use different objects to represent them.
+  // The state pointers are owned by the container.
+  struct AnalysisMap : public llvm::DenseMap<const Decl*, FuncAnalysisPtr> {
+  
+    ~AnalysisMap();
+
+    // use lookup()
+
+    CompleteFunctionAnalysis* completedAnalysisForDecl(const Decl* D) const
+    {
+      if (auto AP = lookup(D)) {
+        if (isa<CompleteFunctionAnalysis*>(AP)) {
+          return AP.get<CompleteFunctionAnalysis*>();
+        }
+      }
+      return nullptr;
+    }
+
+    void dump(Sema& S, llvm::raw_ostream& OS)
+    {
+      OS << "AnalysisMap:\n";
+      for (const auto& item : *this) {
+        CallableInfo CI{ *item.first };
+        const auto AP = item.second;
+        OS << item.first << " " << CI.name(S) << " : ";
+        if (AP.isNull()) {
+          OS << "null\n";
+        } else if (isa<CompleteFunctionAnalysis*>(AP)) {
+          auto* CFA = AP.get<CompleteFunctionAnalysis*>();
+          OS << CFA << " ";
+          CFA->dump(OS);
+        } else if (isa<PendingFunctionAnalysis*>(AP)) {
+          auto* PFA = AP.get<PendingFunctionAnalysis*>();
+          OS << PFA << " ";
+          PFA->dump(OS);
+        } else llvm_unreachable("never");
+      }
+    }
+  };
+  AnalysisMap DeclAnalysis;
+
+public:
+  Analyzer(Sema& S)
+    : mSema{ S }
+  {
+  }
+
+  void run(const TranslationUnitDecl& TU)
+  {
+#if FX_ANALYZER_VERIFY_DECL_LIST
+    verifyRootDecls(TU);
+#endif
+    // Gather all of the effects to be verified to see what operations need to be checked,
+    // and to see which ones are inferrable.
+    {
+      MutableFunctionEffectSet inferrableEffects;
+      for (const FunctionEffect* effect : mSema.AllEffectsToVerify) {
+        const auto Flags = effect->getFlags();
+        if (Flags & FunctionEffect::kInferrableOnCallees) {
+          inferrableEffects.insert(effect);
+        }
+      }
+      AllInferrableEffectsToVerify = FunctionEffectSet::create(inferrableEffects);
+      llvm::outs() << "AllInferrableEffectsToVerify: ";
+      AllInferrableEffectsToVerify.dump(llvm::outs());
+      llvm::outs() << "\n";
+    }
+
+    SmallVector<const Decl*>& verifyQueue = mSema.DeclsWithUnverifiedEffects;
+
+    // It's useful to use DeclsWithUnverifiedEffects as a stack for a
+    // depth-first traversal rather than have a secondary container. But first,
+    // reverse it, so Decls are verified in the order they are declared.
+    std::reverse(verifyQueue.begin(), verifyQueue.end());
+
+    while (!verifyQueue.empty()) {
+      const Decl* D = verifyQueue.back();
+      if (auto AP = DeclAnalysis.lookup(D)) {
+          if (isa<CompleteFunctionAnalysis*>(AP)) {
+            // already done
+            verifyQueue.pop_back();
+            continue;
+          }
+          if (isa<PendingFunctionAnalysis*>(AP)) {
+            // All children have been traversed; finish analysis.
+            auto* pending = AP.get<PendingFunctionAnalysis*>();
+            finishPendingAnalysis(D, pending);
+            verifyQueue.pop_back();
+            continue;
+          }
+          llvm_unreachable("shouldn't happen");
+      }
+
+      auto* pending = verifyDecl(D);
+      if (pending == nullptr) {
+        // completed now
+        verifyQueue.pop_back();
+        continue;
+      }
+
+      for (const auto& call : pending->unverifiedCalls()) {
+        // This lookup could be optimized out if the results could have been saved
+        // from followCall when we traversed the caller's AST. It would however
+        // make the check for recursion more complex.
+        auto AP = DeclAnalysis.lookup(call.Callee);
+        if (AP.isNull()) {
+          verifyQueue.push_back(call.Callee);
+          continue;
+        }
+        if (isa<PendingFunctionAnalysis*>(AP)) {
+          // $$$$$$$$$$$$$$$$$$$$$$$ recursion $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
+          __builtin_trap();
+        }
+        llvm_unreachable("shouldn't happen");
+      }
+    }
+  }
+
+private:
+  // Verify a single Decl. Return the pending structure if that was the result, else null.
+  // This method must not recurse.
+  PendingFunctionAnalysis* verifyDecl(const Decl *D)
+  {
+    const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
+    if (FD != nullptr) {
+      // Currently, built-in functions are always considered safe.
+      if (FD->getBuiltinID() != 0) {
+        return nullptr;
+      }
+      // If it doesn't have a body, then we have to rely on the declaration.
+
+#warning FIXME
+/*      if (!functionIsVerifiable(mSema, FD)) {
+        // const PerfAnnotation PA = FD->getPerfAnnotation();
+        // if (PA != PerfAnnotation::NoLock) {
+        //   Result.setDiagnostic({ DiagnosticID::DeclExternWithoutConstraint, FD->getLocation(), nullptr });
+        // }
+        return;
+      }*/
+    }
+    CallableInfo CInfo{ *D };
+
+    // Build a PendingFunctionAnalysis on the stack. If it turns out to be complete,
+    // we'll have avoided a heap allocation; if it's incomplete, it's a fairly
+    // trivial move to a heap-allocated object.
+    PendingFunctionAnalysis FAnalysis{ CInfo, AllInferrableEffectsToVerify };
+
+    llvm::outs() << "\nVerifying " << CInfo.name(mSema) << " ";
+    FAnalysis.dump(llvm::outs());
+
+    FunctionBodyASTVisitor Visitor{ *this, FAnalysis, CInfo };
+
+    Visitor.run();
+    if (FAnalysis.isComplete()) {
+      completeAnalysis(CInfo, FAnalysis);
+      return nullptr;
+    }
+    // Copy the pending analysis to the heap and save it in the map.
+    auto* pendingPtr = new PendingFunctionAnalysis(std::move(FAnalysis));
+    DeclAnalysis[D] = pendingPtr;
+    llvm::outs() << "inserted pending " << pendingPtr << "\n";
+    DeclAnalysis.dump(mSema, llvm::outs());
+    return pendingPtr;
+  }
+
+  // Consume PendingFunctionAnalysis, transformed to CompleteFunctionAnalysis and inserted
+  // in the container.
+  void completeAnalysis(const CallableInfo& CInfo, PendingFunctionAnalysis& pending)
+  {
+    if (auto* diags = pending.getDiagnosticsForExplicitFX()) {
+      emitDiagnostics(*diags, CInfo, mSema);
+    }
+    auto* completePtr = new CompleteFunctionAnalysis(pending,
+      CInfo.Effects, AllInferrableEffectsToVerify);
+    DeclAnalysis[CInfo.CDecl] = completePtr;
+    llvm::outs() << "inserted complete " << completePtr << "\n";
+    DeclAnalysis.dump(mSema, llvm::outs());
+  }
+
+  // Called after all direct calls requiring inference have been found -- or not.
+  // Generally replicates FunctionBodyASTVisitor::followCall() but without the
+  // possibility of inference.
+  void finishPendingAnalysis(const Decl* D, PendingFunctionAnalysis* pending)
+  {
+      CallableInfo Caller{ *D };
+      for (const auto& call : pending->unverifiedCalls()) {
+        CallableInfo Callee{ *call.Callee };
+        followCall(Caller, *pending, Callee, call.CallLoc, /*assertNoFurtherInference=*/true);
+      }
+      completeAnalysis(Caller, *pending);
+      delete pending;
+      llvm::outs() << "destroyed pending " << pending << "\n";
+  }
+
+  // Here we have a call to a Decl, either explicitly via a CallExpr or some
+  // other AST construct. CallableInfo pertains to the callee.
+  void followCall(const CallableInfo& Caller, PendingFunctionAnalysis &PFA,
+    const CallableInfo& Callee, SourceLocation CallLoc,
+    bool assertNoFurtherInference)
+  {
+    const bool DirectCall = Callee.isDirectCall();
+    FunctionEffectSet CalleeEffects = Callee.Effects;
+    bool isInferencePossible = DirectCall;
+
+    if (DirectCall) {
+      if (auto* CFA = DeclAnalysis.completedAnalysisForDecl(Callee.CDecl)) {
+        CalleeEffects = CFA->VerifiedEffects;
+        isInferencePossible = false; // we've already traversed it
+      }
+    }
+    if (assertNoFurtherInference) {
+      assert(!isInferencePossible);
+    }
+    if (!Callee.isVerifiable()) {
+      isInferencePossible = false;
+    }
+    llvm::outs() << "followCall from " << Caller.name(mSema) << " to " << Callee.name(mSema) 
+      << "; verifiable: " << Callee.isVerifiable() << "; callee ";
+    CalleeEffects.dump(llvm::outs());
+    llvm::outs() << "\n";
+    puts("");
+
+    auto check1Effect = [&](const FunctionEffect* effect, bool inferring) {
+      const auto flags = effect->getFlags();
+      if (flags & FunctionEffect::kVerifyCalls) {
+        const bool diagnose = effect->diagnoseFunctionCall(DirectCall, Caller.CDecl, Caller.Effects,
+          Callee.CDecl, CalleeEffects);
+        if (diagnose) {
+          // If inference is not allowed, or the target is indirect (virtual method/function ptr?),
+          // generate a diagnostic now.
+          if (!isInferencePossible || !(flags & FunctionEffect::kInferrableOnCallees)) {
+            if (Callee.FuncType == SpecialFuncType::None) {
+              PFA.checkAddDiagnostic(inferring, { effect, DiagnosticID::CallsUnsafeDecl, CallLoc, Callee.CDecl });
+            } else {
+              PFA.checkAddDiagnostic(inferring, { effect, DiagnosticID::AllocatesMemory, CallLoc });
+            }
+          } else {
+            // Inference is allowed and necessary; defer it.
+            PFA.addUnverifiedDirectCall(Callee.CDecl, CallLoc);
+          }
+        }
+      }
+    };
+
+    for (auto* effect : PFA.DeclaredVerifiableEffects) {
+      check1Effect(effect, false);
+    }
+
+    for (auto* effect : PFA.FXToInfer) {
+      check1Effect(effect, true);
+    }
+  }
+
+  // Should only be called when determined to be complete.
+  void emitDiagnostics(SmallVector<Diagnostic>& Diags, const CallableInfo& CInfo, Sema& S)
+  {
+#define UNTESTED __builtin_trap();
+#define TESTED
+    const SourceManager& SM = S.getSourceManager();
+    std::sort(Diags.begin(), Diags.end(), [&SM](const Diagnostic& lhs, const Diagnostic& rhs) {
+      return SM.isBeforeInTranslationUnit(lhs.Loc, rhs.Loc);
+    });
+
+    const auto TopFuncName = CInfo.name(S);
+
+    // TODO: Can we get better template instantiation notes?
+    auto checkAddTemplateNote = [&](const Decl* D) {
+      if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+        while (FD != nullptr && FD->isTemplateInstantiation()) {
+          S.Diag(FD->getPointOfInstantiation(), diag::note_func_effect_from_template);
+          FD = FD->getTemplateInstantiationPattern();
+        }
+      }
+    };
+
+    // Top-level diagnostics are warnings.
+    for (const auto& Diag : Diags) {
+      StringRef effectName = Diag.Effect->name();
+      switch (Diag.ID) {
+      case DiagnosticID::None:
+      //case DiagnosticID::DeclExternWithoutConstraint:
+      case DiagnosticID::DeclWithoutConstraintOrInference: // shouldn't happen here
+      //case DiagnosticID::DeclVirtualWithoutConstraint:
+      //case DiagnosticID::DeclFuncPtrWithoutConstraint:
+        llvm_unreachable("Unexpected diagnostic kind");
+        break;
+      case DiagnosticID::AllocatesMemory:
+        S.Diag(Diag.Loc, diag::warn_func_effect_allocates) << effectName << TopFuncName;
+        checkAddTemplateNote(CInfo.CDecl);
+              TESTED
+        break;
+      case DiagnosticID::Throws:
+      case DiagnosticID::Catches:
+        S.Diag(Diag.Loc, diag::warn_func_effect_throws_or_catches) << effectName << TopFuncName;
+        checkAddTemplateNote(CInfo.CDecl);
+              TESTED
+        break;
+      case DiagnosticID::HasStaticLocal:
+        S.Diag(Diag.Loc, diag::warn_func_effect_has_static_local) << effectName << TopFuncName;
+        checkAddTemplateNote(CInfo.CDecl);
+              TESTED
+        break;
+      case DiagnosticID::AccessesThreadLocal:
+        S.Diag(Diag.Loc, diag::warn_func_effect_uses_thread_local) << effectName << TopFuncName;
+        checkAddTemplateNote(CInfo.CDecl);
+              TESTED
+        break;
+      case DiagnosticID::CallsObjC:
+        S.Diag(Diag.Loc, diag::warn_func_effect_calls_objc) << effectName << TopFuncName;
+        checkAddTemplateNote(CInfo.CDecl);
+              TESTED
+        break;
+      case DiagnosticID::CallsDisallowedExpr:
+        S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_expr) << effectName << TopFuncName;
+        checkAddTemplateNote(CInfo.CDecl);
+              UNTESTED
+        break;
+
+      case DiagnosticID::CallsUnsafeDecl:
+        {
+          CallableInfo CalleeInfo{ *Diag.Callee };
+          auto CalleeName = CalleeInfo.name(S);
+
+          S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_func) << effectName << TopFuncName << CalleeName;
+          checkAddTemplateNote(CInfo.CDecl);
+
+          // Emit notes explaining the transitive chain of inferences: Why isn't the callee safe?
+          for (const auto* Callee = Diag.Callee; Callee != nullptr; ) {
+            std::optional<CallableInfo> MaybeNextCallee;
+            auto* completed = DeclAnalysis.completedAnalysisForDecl(CalleeInfo.CDecl);
+            if (completed == nullptr) {
+              // No result - could be
+              // - non-inline
+              // - virtual
+              if (CalleeInfo.CType == CallType::Virtual) {
+                S.Diag(Callee->getLocation(), diag::note_func_effect_call_virtual) << effectName << CalleeName;
+                TESTED
+              } else if (CalleeInfo.CType == CallType::Unknown) {
+                S.Diag(Callee->getLocation(), diag::note_func_effect_call_func_ptr) << effectName << CalleeName;
+                TESTED
+              } else {
+                S.Diag(Callee->getLocation(), diag::note_func_effect_call_extern) << effectName << CalleeName;
+                TESTED
+              }
+              break;
+            }
+            const auto* pDiag2 = completed->firstDiagnosticForEffect(Diag.Effect);
+            if (pDiag2 == nullptr) {
+              break;
+            }
+
+            const auto& Diag2 = *pDiag2;
+            switch (Diag2.ID) {
+            case DiagnosticID::None:
+              llvm_unreachable("Unexpected diagnostic kind");
+              break;
+            // case DiagnosticID::DeclExternWithoutConstraint:
+            //   S.Diag(Diag2.Loc, diag::note_func_effect_call_extern) << effectName << CalleeName;
+            //   break;
+            case DiagnosticID::DeclWithoutConstraintOrInference:
+              S.Diag(Diag2.Loc, diag::note_func_effect_call_not_inferrable) << effectName << CalleeName;
+              TESTED
+              break;
+            // case DiagnosticID::DeclVirtualWithoutConstraint:
+            //   S.Diag(Diag2.Loc, diag::note_func_effect_call_virtual) << effectName << CalleeName;
+            //   break;
+            //case DiagnosticID::DeclFuncPtrWithoutConstraint:
+            case DiagnosticID::CallsDisallowedExpr:
+              S.Diag(Diag2.Loc, diag::note_func_effect_call_func_ptr) << effectName << CalleeName;
+              UNTESTED
+              break;
+            case DiagnosticID::AllocatesMemory:
+              S.Diag(Diag2.Loc, diag::note_func_effect_allocates) << effectName << CalleeName;
+              TESTED
+              break;
+            case DiagnosticID::Throws:
+            case DiagnosticID::Catches:
+              S.Diag(Diag2.Loc, diag::note_func_effect_throws_or_catches) << effectName << CalleeName;
+              TESTED
+              break;
+            case DiagnosticID::HasStaticLocal:
+              S.Diag(Diag2.Loc, diag::note_func_effect_has_static_local) << effectName << CalleeName;
+              UNTESTED
+              break;
+            case DiagnosticID::AccessesThreadLocal:
+              S.Diag(Diag2.Loc, diag::note_func_effect_uses_thread_local) << effectName << CalleeName;
+              UNTESTED
+              break;
+            case DiagnosticID::CallsObjC:
+              S.Diag(Diag2.Loc, diag::note_func_effect_calls_objc) << effectName << CalleeName;
+              UNTESTED
+              break;
+            case DiagnosticID::CallsUnsafeDecl:
+              MaybeNextCallee.emplace(*Diag2.Callee);
+              S.Diag(Diag2.Loc, diag::note_func_effect_calls_disallowed_func) << effectName << CalleeName << MaybeNextCallee->name(S);
+              TESTED
+              break;
+            }
+            checkAddTemplateNote(Callee);
+            Callee = Diag2.Callee;
+            if (MaybeNextCallee) {
+              CalleeInfo = *MaybeNextCallee;
+              CalleeName = CalleeInfo.name(S);
+            }
+          }
+        }
+        break;
+      }
+    }
+  }
+
+  // ----------
+  // This AST visitor is used to traverse the body of a function during effect verification.
+  // This happens in 2 distinct situations:
+  // [1] The function has declared effects which need to be validated.
+  // [2] The function has not explicitly declared an effect in question, and is being
+  //    checked for implicit conformance.
+  // When we are verifying explicit conformance [1] we should generate all diagnostics.
+  // When we are inferring conformance [2] we will need to save enough diagnostics
+  // to provide a note to explain why inference failed; just the first violation per
+  // FunctionEffect.
+  //
+  // Populates a provided FunctionAnalysis object.
+  //
+  // TODO: Currently we create a new RecursiveASTVisitor for every function analysis.
+  // Is it so lightweight that this is OK? It would appear so.
+  struct FunctionBodyASTVisitor : public RecursiveASTVisitor<FunctionBodyASTVisitor> {
+    constexpr static bool Stop = false;
+    constexpr static bool Proceed = true;
+    
+    Analyzer &Outer;
+    PendingFunctionAnalysis &CurrentFunction;
+    CallableInfo& CurrentCaller;
+
+    FunctionBodyASTVisitor(Analyzer &outer, PendingFunctionAnalysis &CurrentFunction,
+      CallableInfo& CurrentCaller)
+      : Outer{ outer }, CurrentFunction{ CurrentFunction }, CurrentCaller{ CurrentCaller }
+    {
+    }
+
+    // -- Entry point --
+    void run()
+    {
+      // The target function itself may have some implicit code paths beyond the body:
+      // member and base constructors and destructors.
+      if (const auto *FD = dyn_cast<const FunctionDecl>(CurrentCaller.CDecl)) {
+        if (auto* Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
+          for (const CXXCtorInitializer* Initer : Ctor->inits()) {
+            if (Expr* Init = Initer->getInit()) {
+              VisitStmt(Init);
+            }
+          }
+        } else if (auto* Dtor = dyn_cast<CXXDestructorDecl>(FD)) {
+          followDestructor(dyn_cast<CXXRecordDecl>(Dtor->getParent()), Dtor);
+        } else if (!FD->isTrivial() && FD->isDefaulted()) {
+          // needed? maybe not
+        }
+      }
+      // else could be BlockDecl
+
+      // Do an AST traversal of the function/block body
+      TraverseDecl(const_cast<Decl*>(CurrentCaller.CDecl));
+    }
+
+    // -- Methods implementing common logic --
+
+    // Only effects whose flags include the specified flag receive a potential diagnostic.
+    // TODO: Consider bypasses for these loops by precomputing the flags we care about?
+    void addDiagnostic(FunctionEffect::FlagBit Flag, DiagnosticID D, SourceLocation Loc,
+      const Decl* Callee = nullptr)
+    {
+      // If there are ANY declared verifiable effects holding the flag, store just one diagnostic.
+      for (auto* effect : CurrentFunction.DeclaredVerifiableEffects) {
+        if (effect->getFlags() & Flag) {
+          addDiagnosticInner(/*inferring=*/false, effect, D, Loc, Callee);
+          break;
+        }
+      }
+      // For each inferred-but-not-verifiable effect holding the flag, store a diagnostic,
+      // if we don't already have a diagnostic for that effect.
+      for (auto* effect : CurrentFunction.FXToInfer) {
+        if (effect->getFlags() & Flag) {
+          addDiagnosticInner(/*inferring=*/true, effect, D, Loc, Callee);
+        }
+      }
+    }
+
+    void addDiagnosticInner(bool inferring, const FunctionEffect* effect, DiagnosticID D,
+      SourceLocation Loc, const Decl* Callee = nullptr)
+    {
+      Diagnostic NewDiag{ effect, D, Loc, Callee };
+      CurrentFunction.checkAddDiagnostic(inferring, NewDiag);
+    }
+
+    // Here we have a call to a Decl, either explicitly via a CallExpr or some
+    // other AST construct. CallableInfo pertains to the callee.
+    void followCall(const CallableInfo& CI, SourceLocation CallLoc)
+    {
+      Outer.followCall(CurrentCaller, CurrentFunction, CI, CallLoc, /*assertNoFurtherInference=*/false);
+    }
+
+    void checkIndirectCall(CallExpr* Call, Expr* CalleeExpr)
+    {
+      const auto CalleeType = CalleeExpr->getType();
+      auto *FPT = CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
+
+      auto check1Effect = [&](const FunctionEffect* effect, bool inferring) {
+        if (effect->getFlags() & FunctionEffect::kVerifyCalls) {
+          if (FPT == nullptr || effect->diagnoseFunctionCall(/*direct=*/false, 
+            CurrentCaller.CDecl, CurrentCaller.Effects, FPT, FPT->getFunctionEffects())) {
+            addDiagnosticInner(inferring, effect, DiagnosticID::CallsDisallowedExpr, Call->getBeginLoc());
+          }
+        }
+      };
+
+      for (auto* effect : CurrentFunction.DeclaredVerifiableEffects) {
+        check1Effect(effect, false);
+      }
+
+      for (auto* effect : CurrentFunction.FXToInfer) {
+        check1Effect(effect, true);
+      }
+    }
+
+    // This destructor's body should be followed by the caller, but here we follow
+    // the field and base destructors.
+    void followDestructor(const CXXRecordDecl* Rec, const CXXDestructorDecl* Dtor)
+    {
+      for (const FieldDecl* Field : Rec->fields()) {
+        followTypeDtor(Field->getType());
+      }
+
+      if (const auto* Class = dyn_cast<CXXRecordDecl>(Rec)) {
+        for (const CXXBaseSpecifier& Base : Class->bases()) {
+          followTypeDtor(Base.getType());
+        }
+        for (const CXXBaseSpecifier& Base : Class->vbases()) {
+          followTypeDtor(Base.getType());
+        }
+      }
+    }
+
+    void followTypeDtor(QualType QT)
+    {
+      const Type* Ty = QT.getTypePtr();
+      while (Ty->isArrayType()) {
+        const ArrayType* Arr = Ty->getAsArrayTypeUnsafe();
+        QT = Arr->getElementType();
+        Ty = QT.getTypePtr();
+      }
+
+      if (Ty->isRecordType()) {
+        if (const CXXRecordDecl* Class = Ty->getAsCXXRecordDecl()) {
+          if (auto* Dtor = Class->getDestructor()) {
+            CallableInfo CI{ *Dtor };
+            followCall(CI, Dtor->getLocation());
+          }
+        }
+        return;
+      }
+      if (Ty->isScalarType() || Ty->isReferenceType() || Ty->isAtomicType()) {
+        return;
+      }
+
+      llvm::errs() << "warning: " << QT << ": unknown special functions\n";
+    }
+
+    // -- Methods for use of RecursiveASTVisitor --
+
+    bool shouldVisitImplicitCode() const { return true; }
+
+    bool shouldWalkTypesOfTypeLocs() const { return false; }
+
+    bool VisitCXXThrowExpr(CXXThrowExpr* Throw)
+    {
+      addDiagnostic(FunctionEffect::kExcludeThrow, DiagnosticID::Throws, Throw->getThrowLoc());
+      return Proceed;
+    }
+
+    bool VisitCXXCatchStmt(CXXCatchStmt* Catch)
+    {
+      addDiagnostic(FunctionEffect::kExcludeCatch, DiagnosticID::Catches, Catch->getCatchLoc());
+      return Proceed;
+    }
+
+    bool VisitObjCMessageExpr(ObjCMessageExpr* Msg)
+    {
+      addDiagnostic(FunctionEffect::kExcludeObjCMessageSend, DiagnosticID::CallsObjC, Msg->getBeginLoc());
+      return Proceed;
+    }
+
+    bool VisitCallExpr(CallExpr* Call)
+    {
+      if constexpr (kDebugLogLevel > 2) {
+        llvm::errs() << "VisitCallExpr : " << Call->getBeginLoc().printToString(Outer.mSema.SourceMgr) << "\n";
+      }
+
+      /*if ((AllFlagsOfFXToVerify & FunctionEffect::kVerifyCalls) == 0u) {
+        return Proceed;
+      }*/
+
+      Expr* CalleeExpr = Call->getCallee();
+      if (const Decl* Callee = CalleeExpr->getReferencedDeclOfCallee()) {
+        CallableInfo CI{ *Callee };
+        followCall(CI, Call->getBeginLoc());
+        return Proceed;
+      }
+
+      if (isa<CXXPseudoDestructorExpr>(CalleeExpr)) {
+        // just destroying a scalar, fine.
+        return Proceed;
+      }
+
+      checkIndirectCall(Call, CalleeExpr);
+
+      // No Decl, just an Expr. It could be a cast or something; we could dig
+      // into it and look for a DeclRefExpr. But for now it should suffice
+      // to look at the type of the Expr. Well, unless we're in a template :-/
+
+      //llvm::errs() << "CalleeExpr ";
+      //CalleeExpr->dumpColor();
+      //llvm::errs() << Call->getBeginLoc().printToString(Outer.S.getSourceManager()) << ": warning: null callee\n";
+
+      return Proceed;
+    }
+
+    bool VisitVarDecl(VarDecl* Var)
+    {
+      if constexpr (kDebugLogLevel > 2) {
+        llvm::errs() << "VisitVarDecl : " << Var->getBeginLoc().printToString(Outer.mSema.SourceMgr) << "\n";
+      }
+
+      if (Var->isStaticLocal()) {
+        addDiagnostic(FunctionEffect::kExcludeStaticLocalVars, DiagnosticID::HasStaticLocal, Var->getLocation());
+      }
+
+      const QualType::DestructionKind DK = Var->needsDestruction(Outer.mSema.getASTContext());
+      if (DK == QualType::DK_cxx_destructor) {
+        QualType QT = Var->getType();
+        if (const auto* ClsType = QT.getTypePtr()->getAs<RecordType>()) {
+          if (const auto* CxxRec = dyn_cast<CXXRecordDecl>(ClsType->getDecl())) {
+            if (const auto* Dtor = CxxRec->getDestructor()) {
+              CallableInfo CI{ *Dtor };
+              followCall(CI, Var->getLocation());
+            }
+          }
+        }
+      }
+      return Proceed;
+    }
+
+    bool VisitCXXNewExpr(CXXNewExpr* New)
+    {
+      // BUG? It seems incorrect that RecursiveASTVisitor does not
+      // visit the call to operator new.
+      if (auto* FD = New->getOperatorNew()) {
+        CallableInfo CI{ *FD, SpecialFuncType::OperatorNew };
+        followCall(CI, New->getBeginLoc());
+      }
+
+      // It's a bit excessive to check operator delete here, since it's
+      // just a fallback for operator new followed by a failed constructor.
+      // We could check it via New->getOperatorDelete().
+
+      // It DOES however visit the called constructor
+      return Proceed;
+    }
+
+    bool VisitCXXDeleteExpr(CXXDeleteExpr* Delete)
+    {
+      // BUG? It seems incorrect that RecursiveASTVisitor does not
+      // visit the call to operator delete.
+      if (auto* FD = Delete->getOperatorDelete()) {
+        CallableInfo CI{ *FD, SpecialFuncType::OperatorDelete };
+        followCall(CI, Delete->getBeginLoc());
+      }
+
+      // It DOES however visit the called destructor
+
+      return Proceed;
+    }
+
+    bool VisitCXXConstructExpr(CXXConstructExpr* Construct)
+    {
+      if constexpr (kDebugLogLevel > 2) {
+        llvm::errs() << "VisitCXXConstructExpr : " << 
+          Construct->getBeginLoc().printToString(Outer.mSema.SourceMgr) << "\n";
+      }
+
+      // BUG? It seems incorrect that RecursiveASTVisitor does not
+      // visit the call to the constructor.
+      const CXXConstructorDecl* Ctor = Construct->getConstructor();
+      CallableInfo CI{ *Ctor };
+      followCall(CI, Construct->getLocation());
+
+      return Proceed;
+    }
+
+    bool VisitCXXDefaultInitExpr(CXXDefaultInitExpr* DEI)
+    {
+      if (auto* Expr = DEI->getExpr()) {
+        TraverseStmt(Expr);
+      }
+      return Proceed;
+    }
+
+    bool TraverseLambdaExpr(LambdaExpr* Lambda)
+    {
+      // We override this so as the be able to skip traversal of the lambda's
+      // body. We have to explicitly traverse the captures.
+      for (unsigned I = 0, N = Lambda->capture_size(); I < N; ++I) {
+        if (TraverseLambdaCapture(Lambda, Lambda->capture_begin() + I,
+          Lambda->capture_init_begin()[I]) == Stop) return Stop;
+      }
+
+      return Proceed;
+    }
+
+    bool TraverseBlockExpr(BlockExpr* /*unused*/)
+    {
+      // TODO: are the capture expressions (ctor call?) safe?
+      return Proceed;
+    }
+
+    bool VisitDeclRefExpr(const DeclRefExpr *E)
+    {
+      const ValueDecl* Val = E->getDecl();
+      if (isa<VarDecl>(Val)) {
+        const VarDecl* Var = cast<VarDecl>(Val);
+        const auto TLSK = Var->getTLSKind();
+        if (TLSK != VarDecl::TLS_None) {
+          // At least on macOS, thread-local variables are initialized on
+          // first access.
+          addDiagnostic(FunctionEffect::kExcludeThreadLocalVars,
+            DiagnosticID::AccessesThreadLocal, E->getLocation());
+        }
+      }
+      return Proceed;
+    }
+
+
+    // Unevaluated contexts: need to skip
+    // see https://reviews.llvm.org/rG777eb4bcfc3265359edb7c979d3e5ac699ad4641
+
+    // bool TraverseTypeLoc(TypeLoc /*unused*/)
+    // {
+    //   // This is a big blunt hammer so that we don't reach __invoke()'s call to declval().
+    //   // Is it correct?
+    //   return Proceed;
+    // }
+
+    bool TraverseGenericSelectionExpr(GenericSelectionExpr *Node) {
+      return TraverseStmt(Node->getResultExpr());
+    }
+    bool TraverseUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *Node) { return Proceed; }
+
+    bool TraverseTypeOfExprTypeLoc(TypeOfExprTypeLoc Node) { return Proceed; }
+
+    bool TraverseDecltypeTypeLoc(DecltypeTypeLoc Node) { return Proceed; }
+
+    bool TraverseCXXNoexceptExpr(CXXNoexceptExpr *Node) { return Proceed; }
+
+    bool TraverseCXXTypeidExpr(CXXTypeidExpr *Node) { return Proceed; }
+  };
+
+#if FX_ANALYZER_VERIFY_DECL_LIST
+  // Sema has accumulated DeclsWithUnverifiedEffects. As a debug check, do our
+  // own AST traversal and see what we find.
+
+  using MatchFinder = ast_matchers::MatchFinder;
+  static constexpr StringRef Tag_Callable = "Callable";
+
+  // -----
+  // Called for every callable in the translation unit.
+  struct CallableFinderCallback : MatchFinder::MatchCallback {
+    Sema& mSema;
+
+    CallableFinderCallback(Sema& S) : mSema{ S } {}
+
+    void run(const MatchFinder::MatchResult &Result) override {
+      if (auto* Callable = Result.Nodes.getNodeAs<Decl>(Tag_Callable)) {
+        if (const auto FX = functionEffectsForDecl(Callable)) {
+          // Reuse this filtering method in Sema
+          mSema.CheckAddCallableWithEffects(Callable, FX);
+        }
+      }
+    }
+
+    static FunctionEffectSet functionEffectsForDecl(const Decl *D) {
+      if (auto* FD = D->getAsFunction()) {
+        return FD->getFunctionEffects();
+      }
+      if (auto* BD = dyn_cast<BlockDecl>(D)) {
+        return BD->getFunctionEffects(); 
+      }
+      return {};
+    }
+
+    static void get(Sema &S,const TranslationUnitDecl& TU)
+    {
+      MatchFinder CallableFinder;
+      CallableFinderCallback Callback{ S };
+
+      using namespace clang::ast_matchers;
+
+      CallableFinder.addMatcher(
+          decl(forEachDescendant(decl(anyOf(
+              functionDecl(hasBody(anything())).bind(Tag_Callable),
+              //objcMethodDecl(isDefinition()).bind(Tag_Callable), // no, always unsafe
+              blockDecl().bind(Tag_Callable))))),
+          &Callback);
+      // Matching LambdaExpr this way [a] doesn't seem to work (need to check for Stmt?)
+      // and [b] doesn't seem necessary, since the anonymous function is reached via the above.
+      // CallableFinder.addMatcher(stmt(forEachDescendant(stmt(lambdaExpr().bind(Tag_Callable)))), &Callback);
+
+      CallableFinder.match(TU, TU.getASTContext());
+    }
+  };
+
+  void verifyRootDecls(const TranslationUnitDecl& TU) const
+  {
+    // If this weren't debug code, it would be good to find a way to move/swap
+    // instead of copying.
+    SmallVector<const Decl *> decls = mSema.DeclsWithUnverifiedEffects;
+    mSema.DeclsWithUnverifiedEffects.clear();
+
+    CallableFinderCallback::get(mSema, TU);
+
+    /*if (decls.size() != mSema.DeclsWithUnverifiedEffects.size())*/ {
+      llvm::errs() << "\nFXAnalysis: mSema gathered " << decls.size()
+        << " Decls; second AST pass found " << mSema.DeclsWithUnverifiedEffects.size() << "\n";
+    }
+  }
+#endif
+
+};
+
+Analyzer::AnalysisMap::~AnalysisMap()
+{
+  for (const auto& item : *this) {
+    auto ptr = item.second;
+    if (isa<PendingFunctionAnalysis*>(ptr)) {
+      delete ptr.get<PendingFunctionAnalysis*>();
+    } else {
+      delete ptr.get<CompleteFunctionAnalysis*>();
+    }
+  }
+}
+
+} // namespace FXAnalysis
+
+#if TEMP_DISABLED
+#if 0
+      // OLD OLD OLD from followCall
+      if (CI.PerfAnnot != PerfAnnotation::None) {
+        // Even if the callable turns out to be unsafe, if it is declared safe,
+        // don't create a chain reaction by propagating the error to its callers.
+        if constexpr (kDebugLogLevel > 1) {
+          llvm::errs() << Outer.mDebugIndent << "followCall: safe: " << int(CI.CType) << " " << CI.name() << "\n";
+        }
+
+        if (CI.isVerifiable()) {
+          // The top-level search for callables isn't finding all template instantiations?
+          // Since we have a function body here, possibly verify now.
+          Outer.determineCallableSafety(CI, /*EmitDiags=*/true);
+        } else {
+          Outer.markWithoutFollowing(CI, DiagnosticID::None);
+        }
+
+        return;
+      }
+
+      if constexpr (kDebugLogLevel > 1) {
+        llvm::errs() << Outer.mDebugIndent << "followCall type " << int(CI.CType) << " " << CI.name() << "\n";
+      }
+
+      if (!CI.isDirectCall()) {
+        // Function pointer or virtual method
+        Outer.markWithoutFollowing(CI, CI.CType == CallType::Virtual ?
+          DiagnosticID::DeclVirtualWithoutConstraint : DiagnosticID::DeclFuncPtrWithoutConstraint);
+        return addDiagnostic(DiagnosticID::CallsUnsafeDecl, CallLoc, CI.CDecl);
+      }
+
+      // Here we have a direct call. Are we allowed to infer? If not, emit a diagnostic.
+      if (!CI.isInferrable()) {
+        Outer.markWithoutFollowing(CI, DiagnosticID::DeclWithoutConstraintOrInference);
+        return addDiagnostic(DiagnosticID::CallsUnsafeDecl, CallLoc, CI.CDecl);
+      }
+
+      const DeclInfo& DI = Outer.determineCallableSafety(CI);
+      if (DI.hasDiagnostic()) {
+        if (CI.FuncType == SpecialFuncType::None) {
+          return addDiagnostic(DiagnosticID::CallsUnsafeDecl, CallLoc, CI.CDecl);
+        }
+        return addDiagnostic(DiagnosticID::AllocatesMemory, CallLoc);
+      }
+#endif
+
+
+struct PerfConstraintAnalyzer {
+  // Move all no_locks functions (both explicit and implicitly via call chain)
+  // into a separate code segment?
+  //constexpr static bool kCreateNoLocksSection = true;
+
+  // If non-null, the unsafe callable.
+  using FollowResult = const FunctionDecl*;
+
+  using MatchFinder = ast_matchers::MatchFinder;
+
+
+  // Information recorded about every visited function/block.
+  struct DeclInfo {
+    explicit DeclInfo(PerfAnnotation PA) {} //: DeclPerfAnnot{ PA } {}
+
+    bool hasDiagnostic() const { return Diag.ID != DiagnosticID::None; }
+    const Diagnostic& diagnostic() const { assert(hasDiagnostic()); return Diag; }
+    void setDiagnostic(const Diagnostic& e)
+    {
+        Diag = e;
+    }
+
+    // Scanning: prevent recursion
+    bool isScanning() const { return Scanning; }
+    void setScanning(bool b) { Scanning = b; }
+
+    Diagnostic Diag;
+
+    // This reflects the declared annotation, not the inferred one.
+    //PerfAnnotation DeclPerfAnnot{};
+
+    // Used to prevent infinite recursion.
+    bool Scanning = false;
+  };
+
+  // This contains an entry for every visited callable. Caution: determineCallableSafety
+  // assumes that an iterator remains valid across calls which may mutate the container.
+  using InferenceMap = std::map<const Decl*, DeclInfo>;
+
+  // --
+
+
+  // -----
+
+  Sema& S;
+  InferenceMap mInferenceMap;
+  std::string mDebugIndent;
+
+  // -----
+
+  PerfConstraintAnalyzer(Sema& S)
+    : S{ S }
+  {
+  }
+
+  // Variant of determineCallableSafety where we already know we can't follow
+  // because it is virtual or a function pointer etc. Or, we don't need to follow
+  // it because we know it's OK but we want to have it in the inference table.
+  void markWithoutFollowing(const CallableInfo& CInfo, DiagnosticID Diag)
+  {
+    auto iter = mInferenceMap.lower_bound(CInfo.CDecl);
+    if (iter != mInferenceMap.end() && iter->first == CInfo.CDecl) {
+      return;
+    }
+    iter = mInferenceMap.insert(iter, { CInfo.CDecl, DeclInfo{ CInfo.PerfAnnot } });
+    if (Diag != DiagnosticID::None) {
+      DeclInfo& Result = iter->second;
+      Result.setDiagnostic({ Diag, CInfo.CDecl->getLocation(), nullptr });
+    }
+  }
+
+  void maybeDiagnose(DeclInfo& Result, const Diagnostic& Diag)
+  {
+    Result.setDiagnostic(Diag);
+  }
+
+  // Returns a populated map entry for the given CallableInfo's Decl.
+  // Caller should take special care to avoid recursion when Scanning is true.
+  // EmitDiags should only be true when called from the top-level traversal
+  // of all attributed functions in the TranslationUnit.
+  const DeclInfo& determineCallableSafety(const CallableInfo& CInfo, bool EmitDiags = false)
+  {
+    // If we have already visited this callable, return the previous result.
+    auto iter = mInferenceMap.lower_bound(CInfo.CDecl);
+    if (iter != mInferenceMap.end() && iter->first == CInfo.CDecl) {
+      return iter->second;
+    }
+
+    if constexpr (kDebugLogLevel) {
+      llvm::errs() << mDebugIndent << "determineCallableSafety -> " << CInfo.name() << "\n";
+    }
+
+    iter = mInferenceMap.insert(iter, { CInfo.CDecl, DeclInfo{ CInfo.PerfAnnot } });
+    DeclInfo& Result = iter->second;
+
+    std::optional<PerfConstraintASTVisitor> MaybeVisitor; // built on demand
+    auto getVisitor = [&]() -> PerfConstraintASTVisitor& {
+      if (!MaybeVisitor) {
+        MaybeVisitor.emplace(*this, /*StopOnFirstDiag=*/!EmitDiags);
+      }
+      return *MaybeVisitor;
+    };
+
+    const FunctionDecl *FD = dyn_cast<FunctionDecl>(CInfo.CDecl);
+    if (FD != nullptr) {
+      // Currently, built-in functions are always considered safe.
+      if (FD->getBuiltinID() != 0) {
+        return Result;
+      }
+      // If it doesn't have a body, then we have to rely on the declaration.
+      if (!functionIsVerifiable(S, FD)) {
+        const PerfAnnotation PA = FD->getPerfAnnotation();
+        if (PA != PerfAnnotation::NoLock) {
+          Result.setDiagnostic({ DiagnosticID::DeclExternWithoutConstraint, FD->getLocation(), nullptr });
+        }
+        return Result;
+      }
+
+      if (auto* Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
+        for (const CXXCtorInitializer* Initer : Ctor->inits()) {
+          if (Expr* Init = Initer->getInit()) {
+            Result.setScanning(true);
+            getVisitor().VisitStmt(Init);
+          }
+        }
+      } else if (auto* Dtor = dyn_cast<CXXDestructorDecl>(FD)) {
+        if (auto* UnsafeCallee = followDestructor(dyn_cast<CXXRecordDecl>(Dtor->getParent()), Dtor)) {
+          //const auto PA = UnsafeCallee->getType()->isNoLock() ? PerfAnnotation::True : PerfAnnotation::False;
+          getVisitor().addDiagnostic(DiagnosticID::CallsUnsafeDecl, FD->getLocation(), UnsafeCallee);
+        }
+      } else if (!FD->isTrivial() && FD->isDefaulted()) {
+        // needed? maybe not
+      }
+    }
+
+    if constexpr (kDebugLogLevel) {
+      mDebugIndent += "    ";
+    }
+
+    Result.setScanning(true);
+
+    auto& Visitor = getVisitor();
+    Visitor.TraverseDecl(const_cast<Decl*>(CInfo.CDecl));
+
+    const auto& Diagnostics = Visitor.Diagnostics;
+
+    Result.setScanning(false);
+
+    if constexpr (kDebugLogLevel) {
+      mDebugIndent = mDebugIndent.substr(0, mDebugIndent.size() - 4);
+      llvm::errs() << mDebugIndent << "determineCallableSafety <- " << CInfo.name() << " : " << Diagnostics.size() << " violations\n";
+      //EmitDiags = true; // TEMPORARY
+    }
+
+    if (!Diagnostics.empty()) {
+      if (EmitDiags) {
+        emitDiagnostics(Diagnostics, CInfo);
+      }
+      Result.setDiagnostic(Diagnostics.front());
+    }
+
+    return Result;
+  }
+
+  void emitDiagnostics(const std::vector<Diagnostic>& Diags,
+    const CallableInfo& CInfo)
+  {
+  }
+
+  // Top-level entry point. Search the entire TU for functions to verify.
+  // Ways to optimize:
+  // - are the diagnostics enabled? if not, bail
+  // - did Sema see any tagged functions with bodies? if not, bail
+  void run(const TranslationUnitDecl& TU)
+  {
+
+    /*if constexpr (kCreateNoLocksSection) {
+      createNoLocksSection();
+    }*/
+  }
+
+  /*void createNoLocksSection()
+  {
+    const char* kSectionName = "__TEXT,__nolock,regular,pure_instructions";
+    if (auto err = S.isValidSectionSpecifier(kSectionName)) {
+      // real diagnostic?
+      llvm::errs() << "error: invalid section name " << kSectionName << " (" << err << ")\n";
+      return;
+    }
+
+    auto& MapEntry = S.getASTContext().SemaAnalysisGeneratedSections[kSectionName];
+    MapEntry.reserve(mInferenceMap.size());
+    for (auto& item : mInferenceMap) {
+      MapEntry.emplace_back(item.first);
+      if constexpr (kDebugLogLevel > 1) {
+        if (auto* F = dyn_cast<FunctionDecl>(item.first)) {
+          CallableInfo CI{ *F, S };
+          llvm::errs() << "nolock: " << CI.name() << "\n";
+        }
+      }
+    }
+  }*/
+};
+#endif // TEMP_DISABLED
+
+// =============================================================================
+
+
 //===----------------------------------------------------------------------===//
 // AnalysisBasedWarnings - Worker object used by Sema to execute analysis-based
 //  warnings on a function, method, or block.
@@ -2534,6 +4022,9 @@ void clang::sema::AnalysisBasedWarnings::IssueWarnings(
                        SourceLocation())) {
     CallableVisitor(CallAnalyzers).TraverseTranslationUnitDecl(TU);
   }
+
+  // TODO: skip this if the warning isn't enabled.
+  FXAnalysis::Analyzer{ S }.run(*TU);
 }
 
 void clang::sema::AnalysisBasedWarnings::IssueWarnings(
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 720d5fd5f0428d..6022e4a838e8aa 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -585,6 +585,27 @@ void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
   Diag(Loc, diag::warn_nullability_lost) << SrcType << DstType;
 }
 
+// Generate diagnostics when adding or removing effects in a type conversion.
+void Sema::diagnoseFunctionEffectConversion(QualType DstType,
+                                          QualType SrcType,
+                                          SourceLocation Loc)
+{
+  llvm::outs() << "diagnoseFunctionEffectConversion " << SrcType << " -> " << DstType << "\n";
+  const auto SrcFX = FunctionEffectSet::get(*SrcType);
+  const auto DstFX = FunctionEffectSet::get(*DstType);
+  if (SrcFX != DstFX) {
+    const auto diffs = FunctionEffectSet::differences(SrcFX, DstFX);
+    for (const auto& item : diffs) {
+      const FunctionEffect* effect = item.first;
+      const bool adding = item.second;
+      if (effect->diagnoseConversion(adding,
+        SrcType, SrcFX, DstType, DstFX)) {
+        Diag(Loc, adding ? diag::warn_invalid_add_func_effects : diag::warn_invalid_remove_func_effects) << effect->name();
+      }
+    }
+  }
+}
+
 void Sema::diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E) {
   // nullptr only exists from C++11 on, so don't warn on its absence earlier.
   if (!getLangOpts().CPlusPlus11)
@@ -661,6 +682,9 @@ ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
 
   diagnoseNullableToNonnullConversion(Ty, E->getType(), E->getBeginLoc());
   diagnoseZeroToNullptrConversion(Kind, E);
+  if (!isCast(CCK) && !E->isNullPointerConstant(Context, Expr::NPC_NeverValueDependent /* ???*/)) {
+    diagnoseFunctionEffectConversion(Ty, E->getType(), E->getBeginLoc());
+  }
 
   QualType ExprTy = Context.getCanonicalType(E->getType());
   QualType TypeTy = Context.getCanonicalType(Ty);
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 1f4a041e88dfff..77fdffef6382e0 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3922,6 +3922,40 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
     return true;
   }
 
+  const auto OldFX = Old->getFunctionEffects();
+  const auto NewFX = New->getFunctionEffects();  
+  if (OldFX != NewFX) {
+    const auto diffs = FunctionEffectSet::differences(OldFX, NewFX);
+    for (const auto& item : diffs) {
+      const FunctionEffect* effect = item.first;
+      const bool adding = item.second;
+      if (effect->diagnoseRedeclaration(adding, *Old, OldFX, *New, NewFX)) {
+        Diag(New->getLocation(), diag::warn_mismatched_func_effect_redeclaration) << effect->name();
+        Diag(Old->getLocation(), diag::note_previous_declaration);
+      }
+    }
+
+    const auto MergedFX = OldFX | NewFX;
+
+    // Having diagnosed any problems, prevent further errors by applying the merged set of effects
+    // to both declarations.
+    auto applyMergedFX = [&](FunctionDecl* FD) {
+      const auto *FPT = FD->getType()->getAs<FunctionProtoType>();
+      FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
+      EPI.FunctionEffects = MergedFX;
+      QualType ModQT = Context.getFunctionType(FD->getReturnType(),
+                                                  FPT->getParamTypes(), EPI);
+
+      FD->setType(ModQT);
+    };
+
+    applyMergedFX(Old);
+    applyMergedFX(New);
+
+    OldQType = Old->getType();
+    NewQType = New->getType();
+  }
+
   if (getLangOpts().CPlusPlus) {
     OldQType = Context.getCanonicalType(Old->getType());
     NewQType = Context.getCanonicalType(New->getType());
@@ -11100,6 +11134,49 @@ Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
   return nullptr;
 }
 
+// Should only be called when getFunctionEffects() returns a non-empty set.
+// Decl should be a FunctionDecl or BlockDecl.
+void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX)
+{
+  if (!D->hasBody()) {
+    if (const auto *FD = D->getAsFunction()) {
+      if (!FD->willHaveBody()) {
+        return;
+      }
+    }
+  }
+
+  if (Diags.getIgnoreAllWarnings() ||
+      (Diags.getSuppressSystemWarnings() &&
+        SourceMgr.isInSystemHeader(D->getLocation())))
+    return;
+
+  if (hasUncompilableErrorOccurred())
+    return;
+
+  // For code in dependent contexts, we'll do this at instantiation time
+  // (??? This was copied from something else in AnalysisBasedWarnings ???)
+  if (cast<DeclContext>(D)->isDependentContext()) {
+    return;
+  }
+
+  // Filter out declarations that the FunctionEffect analysis should skip
+  // and not verify. (??? Is this the optimal order in which to test ???)
+  bool effectsNeedVerification = false;
+  for (const auto *Effect : FX) {
+    if (Effect->getFlags() & FunctionEffect::kRequiresVerification) {
+      AllEffectsToVerify.insert(Effect);
+      effectsNeedVerification = true;
+    }
+  }
+  if (!effectsNeedVerification) {
+    return;
+  }
+
+  // Record the declaration for later analysis.
+  DeclsWithUnverifiedEffects.push_back(D);
+}
+
 /// Determines if we can perform a correct type check for \p D as a
 /// redeclaration of \p PrevDecl. If not, we can generally still perform a
 /// best-effort check.
@@ -15712,6 +15789,12 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
   else
     FD = cast<FunctionDecl>(D);
 
+  auto *Canon = FD->getCanonicalDecl();
+
+  // llvm::outs() << "** ActOnStartOfFunctionDef " << FD->getName() << 
+  //   " " << FD << " " << Canon << " " << FD->getType() << "\n";
+  // getNameForDiagnostic
+
   // Do not push if it is a lambda because one is already pushed when building
   // the lambda in ActOnStartOfLambdaDefinition().
   if (!isLambdaCallOperator(FD))
@@ -15912,6 +15995,12 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
       getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation)
     Diag(FD->getLocation(), diag::warn_function_def_in_objc_container);
 
+  const auto FX = FD->getCanonicalDecl()->getFunctionEffects();
+  llvm::outs() << "^^ " << FX.size() << " effects\n";
+  if (FX) {
+    CheckAddCallableWithEffects(FD, FX);
+  }
+
   return D;
 }
 
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index c00120b59d396e..12f7869441c9be 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -395,6 +395,34 @@ bool Sema::checkStringLiteralArgumentAttr(const ParsedAttr &AL, unsigned ArgNum,
   return checkStringLiteralArgumentAttr(AL, ArgExpr, Str, ArgLocation);
 }
 
+/// Check if the argument \p ArgNum of \p Attr is a compile-time constant
+/// integer (boolean) expression. If not, emit an error and return false.
+bool Sema::checkBoolExprArgumentAttr(const ParsedAttr &AL, unsigned ArgNum,
+                                    bool &Value)
+{
+  if (AL.isInvalid()) {
+    return false;
+  }
+  Expr* ArgExpr = AL.getArgAsExpr(ArgNum);
+  SourceLocation errorLoc{ AL.getLoc() };
+
+  if (AL.isArgIdent(ArgNum)) {
+    IdentifierLoc * IL = AL.getArgAsIdent(ArgNum);
+    errorLoc = IL->Loc;
+  } else if (ArgExpr != nullptr) {
+    auto maybeVal = ArgExpr->getIntegerConstantExpr(Context, &errorLoc);
+    if (maybeVal) {
+      Value = maybeVal->getBoolValue();
+      return true;
+    }
+  }
+
+  AL.setInvalid();
+  Diag(errorLoc, diag::err_attribute_argument_n_type)
+    << AL << ArgNum << AANT_ArgumentConstantExpr;
+  return false;
+}
+
 /// Applies the given attribute to the Decl without performing any
 /// additional semantic checking.
 template <typename AttrType>
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index e258a4f7c89415..dac5d5f3e5c1e6 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18321,6 +18321,26 @@ bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
     return true;
   }
 
+  // Virtual overrides must have the same or stronger performance annotation.
+  const auto OldFX = Old->getFunctionEffects();
+  const auto NewFX = New->getFunctionEffects();
+
+  if (OldFX != NewFX) {
+    const auto diffs = FunctionEffectSet::differences(OldFX, NewFX);
+    bool AnyDiags = false;
+
+    for (const auto& item : diffs) {
+      const FunctionEffect* effect = item.first;
+      const bool adding = item.second;
+      if (effect->diagnoseMethodOverride(adding, *Old, OldFX, *New, NewFX)) {
+        Diag(New->getLocation(), diag::warn_mismatched_func_effect_override) << effect->name();
+        Diag(Old->getLocation(), diag::note_overridden_virtual_function);
+        AnyDiags = true;
+      }
+    }
+    if (AnyDiags) return true;
+  }
+
   CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv();
 
   // If the calling conventions match, everything is fine
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 93f82e68ab6440..643f8e7f444884 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -17126,6 +17126,10 @@ ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc,
   BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back());
   BlockDecl *BD = BSI->TheDecl;
 
+  if (const auto FX = BD->getFunctionEffects()) {
+    CheckAddCallableWithEffects(BD, FX);
+  }
+
   if (BSI->HasImplicitReturnType)
     deduceClosureReturnType(*BSI);
 
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index c34a40fa7c81ac..50007d4e1de119 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -4945,10 +4945,16 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
 
   // If this conversion sequence succeeded and involved implicitly converting a
   // _Nullable type to a _Nonnull one, complain.
-  if (!isCast(CCK))
+  if (!isCast(CCK)) {
     diagnoseNullableToNonnullConversion(ToType, InitialFromType,
                                         From->getBeginLoc());
 
+    // TODO: This generates a redundant diagnostic for:
+    // void (^nl_block0)() NOLOCK = ^(){};
+    // if (!From->isNullPointerConstant(Context, Expr::NPC_NeverValueDependent /* ???*/))
+    //   diagnoseFunctionEffectConversion(ToType, InitialFromType,
+    //                                         From->getBeginLoc());
+  }
   return From;
 }
 
diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index 5b95bae567b721..0e1a0f8dfdbabc 100644
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -1888,6 +1888,11 @@ ExprResult Sema::BuildCaptureInit(const Capture &Cap,
 ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body) {
   LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
   ActOnFinishFunctionBody(LSI.CallOperator, Body);
+
+  if (const auto FX = LSI.CallOperator->getFunctionEffects()) {
+    CheckAddCallableWithEffects(LSI.CallOperator, FX);
+  }
+
   return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
 }
 
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index b0c693f078efe2..8f1563e7884429 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1786,6 +1786,9 @@ ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType,
 /// type.
 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
                                 QualType &ResultTy) {
+
+  llvm::outs() << "IsFunctionConversion " << FromType << " " << ToType << "\n";
+
   if (Context.hasSameUnqualifiedType(FromType, ToType))
     return false;
 
@@ -1866,6 +1869,30 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
       FromFn = QT->getAs<FunctionType>();
       Changed = true;
     }
+
+#if 1
+    // NOTE (TEMP): this works for C++ to allow dropping effects.
+    // For plain C, however, this creates an error when dropping effects!
+
+    // Transparently add/drop effects; here we are concerned with
+    // language rules/canonicalization. Adding/dropping effects is a warning.
+    auto FromFX = FromFPT->getFunctionEffects();
+    auto ToFX = ToFPT->getFunctionEffects();
+    if (FromFX != ToFX) {
+      llvm::outs() << "IsFunctionConversion effects change " << FromType << " -> " << ToType << "\n";
+
+      //const auto MergedFX = FunctionEffectSet::getIntersection(FromFX, ToFX);
+      // TODO: diagnose conflicts
+
+      FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
+      ExtInfo.FunctionEffects = ToFX;
+      QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
+                                            FromFPT->getParamTypes(), ExtInfo);
+      FromFn = QT->getAs<FunctionType>();
+      llvm::outs() << "  produced " << QT << "\n";
+      Changed = true;
+    }
+#endif
   }
 
   if (!Changed)
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 3148299f6467af..2bc6b5b3880a8e 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -144,6 +144,8 @@ static void diagnoseBadTypeAttribute(Sema &S, const ParsedAttr &attr,
 #define FUNCTION_TYPE_ATTRS_CASELIST                                           \
   case ParsedAttr::AT_NSReturnsRetained:                                       \
   case ParsedAttr::AT_NoReturn:                                                \
+  case ParsedAttr::AT_NoLock:                                                  \
+  case ParsedAttr::AT_NoAlloc:                                                 \
   case ParsedAttr::AT_Regparm:                                                 \
   case ParsedAttr::AT_CmseNSCall:                                              \
   case ParsedAttr::AT_ArmStreaming:                                            \
@@ -209,10 +211,18 @@ namespace {
     /// validating that noderef was used on a pointer or array.
     bool parsedNoDeref;
 
+    // Flags to diagnose illegal permutations of nolock(cond) and noalloc(cond).
+    // Manual logic for finding previous attributes would be more complex,
+    // unless we transoformed nolock/noalloc(false) into distinct separate
+    // attributes from the ones which are parsed.
+    unsigned char parsedNolock : 2;
+    unsigned char parsedNoalloc : 2;
+
   public:
     TypeProcessingState(Sema &sema, Declarator &declarator)
         : sema(sema), declarator(declarator),
-          chunkIndex(declarator.getNumTypeObjects()), parsedNoDeref(false) {}
+          chunkIndex(declarator.getNumTypeObjects()), parsedNoDeref(false),
+          parsedNolock(0), parsedNoalloc(0) {}
 
     Sema &getSema() const {
       return sema;
@@ -339,6 +349,11 @@ namespace {
 
     bool didParseNoDeref() const { return parsedNoDeref; }
 
+    void setParsedNolock(unsigned char v) { parsedNolock = v; }
+    unsigned char getParsedNolock() const { return parsedNolock; }
+    void setParsedNoalloc(unsigned char v) { parsedNoalloc = v; }
+    unsigned char getParsedNoalloc() const { return parsedNoalloc; }
+
     ~TypeProcessingState() {
       if (savedAttrs.empty())
         return;
@@ -7926,6 +7941,114 @@ static Attr *getCCTypeAttr(ASTContext &Ctx, ParsedAttr &Attr) {
   llvm_unreachable("unexpected attribute kind!");
 }
 
+static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
+  ParsedAttr &attr, QualType &type, FunctionTypeUnwrapper& unwrapped)
+{
+  // Values of nolockState / noallocState
+  enum {
+    kNotSeen   = 0,
+    kSeenFalse = 1,
+    kSeenTrue  = 2
+  };
+
+  const bool isNoLock = attr.getKind() == ParsedAttr::AT_NoLock;
+  Sema &S = state.getSema();
+
+  // Delay if this is not a function type.
+  if (!unwrapped.isFunctionType())
+    return false;
+
+  // Require FunctionProtoType
+  auto *FPT = unwrapped.get()->getAs<FunctionProtoType>();
+  if (FPT == nullptr) {
+    // TODO: special diagnostic?
+    return false;
+  }
+
+  // Parse the conditional expression, if any
+  bool Cond = true; // default
+  if (attr.getNumArgs() > 0) {
+    if (!S.checkBoolExprArgumentAttr(attr, 0, Cond)) {
+      attr.setInvalid();
+      return false;
+    }
+  }
+
+  FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
+
+  auto incompatible = [&](StringRef attrTrue, StringRef attrFalse) {
+    Sema &S = state.getSema();
+    S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
+        << attrTrue << attrFalse
+        << false;
+    // we don't necessarily have the location of the previous attribute,
+    // so no note.
+    attr.setInvalid();
+    return true;
+  };
+
+  // check nolock(true) against nolock(false), and same for noalloc
+  const unsigned newState = Cond ? kSeenTrue : kSeenFalse;
+  const unsigned oppositeNewState = Cond ? kSeenFalse : kSeenTrue;
+  if (isNoLock) {
+    if (state.getParsedNolock() == oppositeNewState) {
+      return incompatible("nolock(true)", "nolock(false)");
+    }
+    // also check nolock(true) against noalloc(false)
+    if (Cond && state.getParsedNoalloc() == kSeenFalse) {
+      return incompatible("nolock(true)", "noalloc(false)");
+    }
+    state.setParsedNolock(newState);
+  } else {
+    if (state.getParsedNoalloc() == oppositeNewState) {
+      return incompatible("noalloc(true)", "noalloc(false)");
+    }
+    // also check nolock(true) against noalloc(false)
+    if (state.getParsedNolock() == kSeenTrue) {
+      if (!Cond) {
+        return incompatible("nolock(true)", "noalloc(false)");
+      }
+      // Ignore noalloc(true) since we already have nolock(true).
+      return true;
+    }
+    state.setParsedNoalloc(newState);
+  }
+  
+  if (!Cond) {
+    // nolock(false) and noalloc(false) are represented as sugar, with AttributedType
+    Attr *A = nullptr;
+    if (isNoLock) {
+      A = NoLockAttr::Create(S.Context, false);
+    } else {
+      A = NoAllocAttr::Create(S.Context, false);
+    }
+    type = state.getAttributedType(A, type, type);
+    return true;
+  }
+
+  const FunctionEffect* Effect = nullptr;
+  if (isNoLock) {
+    Effect = &NoLockNoAllocEffect::nolock_instance();
+  } else {
+    Effect = &NoLockNoAllocEffect::noalloc_instance();
+  }
+
+  MutableFunctionEffectSet newEffectSet{ Effect };
+  if (EPI.FunctionEffects) {
+    // Preserve all previous effects - except noalloc, when we are adding nolock
+    for (const auto* effect : EPI.FunctionEffects) {
+      if (!(isNoLock && effect->type() == FunctionEffect::kNoAllocTrue))
+        newEffectSet.insert(effect);
+    }
+  }
+
+  EPI.FunctionEffects = FunctionEffectSet::create(newEffectSet);
+  QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
+                                              FPT->getParamTypes(), EPI);
+  type = unwrapped.wrap(S, newtype->getAs<FunctionType>());
+  return true;
+}
+
 static bool checkMutualExclusion(TypeProcessingState &state,
                                  const FunctionProtoType::ExtProtoInfo &EPI,
                                  ParsedAttr &Attr,
@@ -8239,6 +8362,11 @@ static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
     return true;
   }
 
+  if (attr.getKind() == ParsedAttr::AT_NoLock
+   || attr.getKind() == ParsedAttr::AT_NoAlloc) {
+    return handleNoLockNoAllocTypeAttr(state, attr, type, unwrapped);
+  }
+
   // Delay if the type didn't work out to a function.
   if (!unwrapped.isFunctionType()) return false;
 
diff --git a/clang/test/Sema/attr-nolock.cpp b/clang/test/Sema/attr-nolock.cpp
new file mode 100644
index 00000000000000..3f9938a2e54601
--- /dev/null
+++ b/clang/test/Sema/attr-nolock.cpp
@@ -0,0 +1,78 @@
+// RUN: %clang_cc1 %s -ast-dump -fblocks | FileCheck %s
+// expected-no-diagnostics
+
+// Make sure that the attribute gets parsed and attached to the correct AST elements.
+// Update 1 Mar 2024
+
+#pragma clang diagnostic ignored "-Wunused-variable"
+
+// =========================================================================================
+// Square brackets, true
+
+#define NOLOCK [[clang::nolock]]
+
+// On the type of the FunctionDecl
+void nl_function() NOLOCK;
+// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nolock))'
+
+// On the type of the VarDecl holding a function pointer
+void (*nl_func_a)() NOLOCK;
+// CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nolock))'
+
+// Check alternate attribute type and placement
+__attribute__((clang_nolock)) void (*nl_func_b)(void);
+// CHECK: VarDecl {{.*}} nl_func_b 'void (*)() __attribute__((clang_nolock))'
+
+// On the type of the ParmVarDecl of a function parameter
+static void nlReceiver(void (*nl_func)() NOLOCK);
+// CHECK: ParmVarDecl {{.*}} nl_func 'void (*)() __attribute__((clang_nolock))'
+
+// As an AttributedType within the nested types of a typedef
+typedef void (*nl_fp_type)() NOLOCK;
+// CHECK: TypedefDecl {{.*}} nl_fp_type 'void (*)() __attribute__((clang_nolock))'
+using nl_fp_talias = void (*)() NOLOCK;
+// CHECK: TypeAliasDecl {{.*}} nl_fp_talias 'void (*)() __attribute__((clang_nolock))'
+
+// From a typedef or typealias, on a VarDecl
+nl_fp_type nl_fp_var1;
+// CHECK: VarDecl {{.*}} nl_fp_var1 'nl_fp_type':'void (*)() __attribute__((clang_nolock))'
+nl_fp_talias nl_fp_var2;
+// CHECK: VarDecl {{.*}} nl_fp_var2 'nl_fp_talias':'void (*)() __attribute__((clang_nolock))'
+
+// On type of a FieldDecl
+struct Struct {
+	void (*nl_func_field)() NOLOCK;
+// CHECK: FieldDecl {{.*}} nl_func_field 'void (*)() __attribute__((clang_nolock))'
+};
+
+// noalloc should be subsumed into nolock
+void nl1() [[clang::nolock]] [[clang::noalloc]];
+// CHECK: FunctionDecl {{.*}} nl1 'void () __attribute__((clang_nolock))'
+
+void nl2() [[clang::noalloc]] [[clang::nolock]];
+// CHECK: FunctionDecl {{.*}} nl2 'void () __attribute__((clang_nolock))'
+
+// --- Blocks ---
+
+// On the type of the VarDecl holding a BlockDecl
+void (^nl_block1)() NOLOCK = ^() NOLOCK {};
+// CHECK: VarDecl {{.*}} nl_block1 'void (^)() __attribute__((clang_nolock))'
+
+int (^nl_block2)() NOLOCK = ^() NOLOCK { return 0; };
+// CHECK: VarDecl {{.*}} nl_block2 'int (^)() __attribute__((clang_nolock))'
+
+// The operand of the CallExpr is an ImplicitCastExpr of a DeclRefExpr -> nl_block which hold the attribute
+static void blockCaller() { nl_block1(); }
+// CHECK: DeclRefExpr {{.*}} 'nl_block1' 'void (^)() __attribute__((clang_nolock))'
+
+// $$$ TODO: There are still some loose ends in all the methods of the lambda
+auto nl_lambda = []() NOLOCK {};
+
+// =========================================================================================
+// Square brackets, false
+
+void nl_func_false() [[clang::nolock(false)]];
+// CHECK: FunctionDecl {{.*}} nl_func_false 'void () __attribute__((clang_nolock(false)))'
+
+// TODO: Duplicate the above for noalloc
+// TODO: Duplicate the above for GNU-style attribute?
diff --git a/clang/test/Sema/attr-nolock2.cpp b/clang/test/Sema/attr-nolock2.cpp
new file mode 100644
index 00000000000000..9c494dcdd581db
--- /dev/null
+++ b/clang/test/Sema/attr-nolock2.cpp
@@ -0,0 +1,88 @@
+// RUN: %clang_cc1 -fsyntax-only -fblocks -verify %s
+// R UN: %clang_cc1 -fsyntax-only -fblocks -verify -x c -std=c2x %s
+
+// TODO: There's a problem with diagnosing type conversions in plain C.
+
+#pragma clang diagnostic error "-Wstrict-prototypes"
+
+#if !__has_attribute(clang_nolock)
+#error "the 'nolock' attribute is not available"
+#endif
+
+#if 1 // TEMP_DISABLE
+
+// --- ATTRIBUTE SYNTAX: COMBINATIONS ---
+// Check invalid combinations of nolock/noalloc attributes
+void nl_true_false_1(void) [[clang::nolock(true)]] [[clang::nolock(false)]]; // expected-error {{nolock(true) and nolock(false) attributes are not compatible}}
+void nl_true_false_2(void) [[clang::nolock(false)]] [[clang::nolock(true)]]; // expected-error {{nolock(true) and nolock(false) attributes are not compatible}}
+
+void na_true_false_1(void) [[clang::noalloc(true)]] [[clang::noalloc(false)]]; // expected-error {{noalloc(true) and noalloc(false) attributes are not compatible}}
+void na_true_false_2(void) [[clang::noalloc(false)]] [[clang::noalloc(true)]]; // expected-error {{noalloc(true) and noalloc(false) attributes are not compatible}}
+
+void nl_true_na_true_1(void) [[clang::nolock]] [[clang::noalloc]];
+void nl_true_na_true_2(void) [[clang::noalloc]] [[clang::nolock]];
+
+void nl_true_na_false_1(void) [[clang::nolock]] [[clang::noalloc(false)]]; // expected-error {{nolock(true) and noalloc(false) attributes are not compatible}}
+void nl_true_na_false_2(void) [[clang::noalloc(false)]] [[clang::nolock]]; // expected-error {{nolock(true) and noalloc(false) attributes are not compatible}}
+
+void nl_false_na_true_1(void) [[clang::nolock(false)]] [[clang::noalloc]];
+void nl_false_na_true_2(void) [[clang::noalloc]] [[clang::nolock(false)]];
+
+void nl_false_na_false_1(void) [[clang::nolock(false)]] [[clang::noalloc(false)]];
+void nl_false_na_false_2(void) [[clang::noalloc(false)]] [[clang::nolock(false)]];
+
+// --- TYPE CONVERSIONS ---
+
+void unannotated(void);
+void nolock(void) [[clang::nolock]];
+void noalloc(void) [[clang::noalloc]];
+void type_conversions(void)
+{
+	// It's fine to remove a performance constraint.
+	void (*fp_plain)(void);
+
+	fp_plain = unannotated;
+	fp_plain = nolock;
+	fp_plain = noalloc;
+
+	// Adding/spoofing nolock is unsafe.
+	void (*fp_nolock)(void) [[clang::nolock]];
+	fp_nolock = nolock;
+	fp_nolock = unannotated; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
+	fp_nolock = noalloc; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
+
+	// Adding/spoofing noalloc is unsafe.
+	void (*fp_noalloc)(void) [[clang::noalloc]];
+	fp_noalloc = noalloc;
+	fp_noalloc = nolock; // no warning because nolock includes noalloc fp_noalloc = unannotated;
+	fp_noalloc = unannotated; // expected-warning {{attribute 'noalloc' should not be added via type conversion}}
+}
+
+// --- VIRTUAL METHODS ---
+#ifdef __cplusplus
+struct Base {
+	virtual void f1();
+	virtual void nolock() noexcept [[clang::nolock]]; // expected-note {{overridden virtual function is here}}
+	virtual void noalloc() noexcept [[clang::noalloc]]; // expected-note {{overridden virtual function is here}}
+};
+
+struct Derived : public Base {
+	void f1() [[clang::nolock]] override;
+	void nolock() noexcept override; // expected-warning {{attribute 'nolock' on overriding function does not match base version}}
+	void noalloc() noexcept override; // expected-warning {{attribute 'noalloc' on overriding function does not match base version}}
+};
+#endif // __cplusplus
+
+// --- REDECLARATIONS ---
+
+int f2(void);
+// redeclaration with a stronger constraint is OK.
+int f2(void) [[clang::nolock]]; // expected-note {{previous declaration is here}}
+int f2(void) { return 42; } // expected-warning {{attribute 'nolock' on function does not match previous declaration}}
+
+int f3(void);
+// redeclaration with a stronger constraint is OK.
+int f3(void) [[clang::noalloc]]; // expected-note {{previous declaration is here}}
+int f3(void) { return 42; } // expected-warning {{attribute 'noalloc' on function does not match previous declaration}}
+
+#endif // TEMP_DISABLE
diff --git a/clang/test/Sema/attr-nolock3.cpp b/clang/test/Sema/attr-nolock3.cpp
new file mode 100644
index 00000000000000..cfe52da16447c1
--- /dev/null
+++ b/clang/test/Sema/attr-nolock3.cpp
@@ -0,0 +1,144 @@
+// RUN: %clang_cc1 -fsyntax-only -fblocks -fcxx-exceptions -verify %s
+
+#if !__has_attribute(clang_nolock)
+#error "the 'nolock' attribute is not available"
+#endif
+
+// --- CONSTRAINTS ---
+#if 0 // TEMP_DISABLE
+
+void nl1() [[clang::nolock]]
+{
+	auto* pInt = new int; // expected-warning {{'nolock' function 'nl1' must not allocate or deallocate memory}}
+}
+
+void nl2() [[clang::nolock]]
+{
+	static int global; // expected-warning {{'nolock' function 'nl2' must not have static locals}}
+}
+
+void nl3() [[clang::nolock]]
+{
+	try {
+		throw 42; // expected-warning {{'nolock' function 'nl3' must not throw or catch exceptions}}
+	}
+	catch (...) { // expected-warning {{'nolock' function 'nl3' must not throw or catch exceptions}}
+	}
+}
+
+void nl4_inline() {}
+void nl4_not_inline(); // expected-note {{'nl4_not_inline' cannot be inferred 'nolock' because it has no definition in this translation unit}}
+
+void nl4() [[clang::nolock]]
+{
+	nl4_inline(); // OK
+	nl4_not_inline(); // expected-warning {{'nolock' function 'nl4' must not call non-'nolock' function 'nl4_not_inline'}}
+}
+
+
+struct HasVirtual {
+	virtual void unsafe(); // expected-note {{'HasVirtual::unsafe' cannot be inferred 'nolock' because it is virtual}}
+};
+
+void nl5() [[clang::nolock]]
+{
+ 	HasVirtual hv;
+ 	hv.unsafe(); // expected-warning {{'nolock' function 'nl5' must not call non-'nolock' function 'HasVirtual::unsafe'}}
+}
+
+void nl6_unsafe(); // expected-note {{'nl6_unsafe' cannot be inferred 'nolock' because it has no definition in this translation unit}}
+void nl6_transitively_unsafe()
+{
+	nl6_unsafe(); // expected-note {{'nl6_transitively_unsafe' cannot be inferred 'nolock' because it calls non-'nolock' function 'nl6_unsafe'}}
+}
+
+void nl6() [[clang::nolock]]
+{
+	nl6_transitively_unsafe(); // expected-warning {{'nolock' function 'nl6' must not call non-'nolock' function 'nl6_transitively_unsafe'}}
+}
+
+thread_local int tl_var{ 42 };
+
+bool tl_test() [[clang::nolock]]
+{
+	return tl_var > 0; // expected-warning {{'nolock' function 'tl_test' must not use thread-local variables}}
+}
+
+void nl7()
+{
+	// Make sure we verify blocks
+	auto blk = ^() [[clang::nolock]] {
+		throw 42; // expected-warning {{'nolock' function '(block 0)' must not throw or catch exceptions}}
+	};
+}
+
+void nl8()
+{
+	// Make sure we verify lambdas
+	auto lambda = []() [[clang::nolock]] {
+		throw 42; // expected-warning {{'nolock' function 'nl8()::(anonymous class)::operator()' must not throw or catch exceptions}}
+	};
+}
+
+// Make sure template expansions are found and verified.
+	template <typename T>
+	struct Adder {
+		static T add_explicit(T x, T y) [[clang::nolock]]
+		{
+			return x + y; // expected-warning {{'nolock' function 'Adder<Stringy>::add_explicit' must not call non-'nolock' function 'operator+'}}
+		}
+		static T add_implicit(T x, T y)
+		{
+			return x + y; // expected-note {{'Adder<Stringy2>::add_implicit' cannot be inferred 'nolock' because it calls non-'nolock' function 'operator+'}}
+		}
+	};
+
+	struct Stringy {
+		friend Stringy operator+(const Stringy& x, const Stringy& y)
+		{
+			// Do something inferably unsafe
+			auto* z = new char[42]; // expected-note {{'operator+' cannot be inferred 'nolock' because it allocates/deallocates memory}}
+			return {};
+		}
+	};
+
+	struct Stringy2 {
+		friend Stringy2 operator+(const Stringy2& x, const Stringy2& y)
+		{
+			// Do something inferably unsafe
+			throw 42; // expected-note {{'operator+' cannot be inferred 'nolock' because it throws or catches exceptions}}
+		}
+	};
+
+void nl9() [[clang::nolock]]
+{
+	Adder<int>::add_explicit(1, 2);
+	Adder<int>::add_implicit(1, 2);
+
+	Adder<Stringy>::add_explicit({}, {}); // expected-note {{in template expansion here}}
+	Adder<Stringy2>::add_implicit({}, {}); // expected-warning {{'nolock' function 'nl9' must not call non-'nolock' function 'Adder<Stringy2>::add_implicit'}} \
+		expected-note {{in template expansion here}}
+}
+
+void nl10(
+	void (*fp1)(), // expected-note {{'fp1' cannot be inferred 'nolock' because it is a function pointer}}
+	void (*fp2)() [[clang::nolock]]
+	) [[clang::nolock]]
+{
+	fp1(); // expected-warning {{'nolock' function 'nl10' must not call non-'nolock' function 'fp1'}}
+	fp2();
+}
+
+#endif // TEMP_DISABLE
+
+// --- PLAYGROUND ---
+
+void nl11_no_inference() [[clang::nolock(false)]] // expected-note {{'nl11_no_inference' does not permit inference of 'nolock'}}
+{
+}
+
+void nl11() [[clang::nolock]]
+{
+	nl11_no_inference(); // expected-warning {{'nolock' function 'nl11' must not call non-'nolock' function 'nl11_no_inference'}}
+}
+

>From 2a1b0d2d99c9bc4595dfc98f250bf43d23a28093 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 12 Mar 2024 13:22:58 -0700
Subject: [PATCH 02/40] Cleanup, mostly code style

---
 clang/include/clang/AST/Type.h                |   24 +-
 clang/include/clang/Basic/Attr.td             |    4 +-
 .../clang/Basic/DiagnosticSemaKinds.td        |    6 +-
 clang/lib/AST/Decl.cpp                        |   80 +-
 clang/lib/AST/Type.cpp                        |  287 ++--
 clang/lib/AST/TypePrinter.cpp                 |    8 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 1316 +++++++----------
 clang/lib/Sema/Sema.cpp                       |   23 +-
 clang/lib/Sema/SemaDecl.cpp                   |   31 +-
 clang/lib/Sema/SemaDeclAttr.cpp               |   16 +-
 clang/lib/Sema/SemaDeclCXX.cpp                |   17 +-
 clang/lib/Sema/SemaType.cpp                   |   44 +-
 clang/test/Sema/attr-nolock-wip.cpp           |   19 +
 clang/test/Sema/attr-nolock2.cpp              |    4 -
 clang/test/Sema/attr-nolock3.cpp              |    7 +-
 15 files changed, 782 insertions(+), 1104 deletions(-)
 create mode 100644 clang/test/Sema/attr-nolock-wip.cpp

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 41c60a6e221d4e..de21561ce5dcad 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4221,7 +4221,7 @@ class FunctionEffectSet {
 
     UniquedAndSortedFX(Base Array) : Base(Array) {}
     UniquedAndSortedFX(const FunctionEffect **Ptr, size_t Len)
-        : Base(ptr, len) {}
+        : Base(Ptr, Len) {}
 
     bool operator<(const UniquedAndSortedFX &rhs) const;
   };
@@ -7955,14 +7955,14 @@ class FunctionEffect {
       llvm::PointerUnion<const Decl *, const FunctionProtoType *>;
 
   FunctionEffect(EffectType T, Flags F, const char *Name)
-      : Type_{T}, Flags_{F}, Name{Name} {}
+      : Type_(T), Flags_(F), Name(Name) {}
   virtual ~FunctionEffect();
 
   /// The type of the effect.
   EffectType type() const { return Type_; }
 
   /// Flags describing behaviors of the effect.
-  Flags getFlags() const { return Flags_; }
+  Flags flags() const { return Flags_; }
 
   /// The description printed in diagnostics, e.g. 'nolock'.
   StringRef name() const { return Name; }
@@ -7972,13 +7972,13 @@ class FunctionEffect {
 
   /// Return true if adding or removing the effect as part of a type conversion
   /// should generate a diagnostic.
-  virtual bool diagnoseConversion(bool adding, QualType OldType,
+  virtual bool diagnoseConversion(bool Adding, QualType OldType,
                                   FunctionEffectSet OldFX, QualType NewType,
                                   FunctionEffectSet NewFX) const;
 
   /// Return true if adding or removing the effect in a redeclaration should
   /// generate a diagnostic.
-  virtual bool diagnoseRedeclaration(bool adding,
+  virtual bool diagnoseRedeclaration(bool Adding,
                                      const FunctionDecl &OldFunction,
                                      FunctionEffectSet OldFX,
                                      const FunctionDecl &NewFunction,
@@ -7986,7 +7986,7 @@ class FunctionEffect {
 
   /// Return true if adding or removing the effect in a C++ virtual method 
   /// override should generate a diagnostic.
-  virtual bool diagnoseMethodOverride(bool adding,
+  virtual bool diagnoseMethodOverride(bool Adding,
                                       const CXXMethodDecl &OldMethod,
                                       FunctionEffectSet OldFX,
                                       const CXXMethodDecl &NewMethod,
@@ -8003,7 +8003,7 @@ class FunctionEffect {
   // returned for a direct call, then the kInferrableOnCallees flag may trigger
   // inference rather than an immediate diagnostic. Caller should be assumed to
   // have the effect (it may not have it explicitly when inferring).
-  virtual bool diagnoseFunctionCall(bool direct, const Decl *Caller,
+  virtual bool diagnoseFunctionCall(bool Direct, const Decl *Caller,
                                     FunctionEffectSet CallerFX,
                                     CalleeDeclOrType Callee,
                                     FunctionEffectSet CalleeFX) const;
@@ -8018,21 +8018,21 @@ class NoLockNoAllocEffect : public FunctionEffect {
   static const NoLockNoAllocEffect &nolock_instance();
   static const NoLockNoAllocEffect &noalloc_instance();
 
-  NoLockNoAllocEffect(EffectType ty, const char *name);
+  NoLockNoAllocEffect(EffectType Type, const char *Name);
   ~NoLockNoAllocEffect() override;
 
   std::string attribute() const override;
 
-  bool diagnoseConversion(bool adding, QualType OldType,
+  bool diagnoseConversion(bool Adding, QualType OldType,
                           FunctionEffectSet OldFX, QualType NewType,
                           FunctionEffectSet NewFX) const override;
 
-  bool diagnoseRedeclaration(bool adding, const FunctionDecl &OldFunction,
+  bool diagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
                              FunctionEffectSet OldFX,
                              const FunctionDecl &NewFunction,
                              FunctionEffectSet NewFX) const override;
 
-  bool diagnoseMethodOverride(bool adding, const CXXMethodDecl &OldMethod,
+  bool diagnoseMethodOverride(bool Adding, const CXXMethodDecl &OldMethod,
                               FunctionEffectSet OldFX,
                               const CXXMethodDecl &NewMethod,
                               FunctionEffectSet NewFX) const override;
@@ -8040,7 +8040,7 @@ class NoLockNoAllocEffect : public FunctionEffect {
   bool canInferOnDecl(const Decl *Caller,
                       FunctionEffectSet CallerFX) const override;
 
-  bool diagnoseFunctionCall(bool direct, const Decl *Caller,
+  bool diagnoseFunctionCall(bool Direct, const Decl *Caller,
                             FunctionEffectSet CallerFX, CalleeDeclOrType Callee,
                             FunctionEffectSet CalleeFX) const override;
 };
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 78bbe5185741b4..4033b9efb86f39 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1404,7 +1404,7 @@ def CXX11NoReturn : InheritableAttr {
 
 def NoLock : DeclOrTypeAttr {
   let Spellings = [CXX11<"clang", "nolock">,
-                   C2x<"clang", "nolock">,
+                   C23<"clang", "nolock">,
                    GNU<"clang_nolock">];
 
   // Subjects - not needed?
@@ -1416,7 +1416,7 @@ def NoLock : DeclOrTypeAttr {
 
 def NoAlloc : DeclOrTypeAttr {
   let Spellings = [CXX11<"clang", "noalloc">,
-                   C2x<"clang", "noalloc">,
+                   C23<"clang", "noalloc">,
                    GNU<"clang_noalloc">];
   // Subjects - not needed?
   //let Subjects = SubjectList<[FunctionLike, Block, TypedefName], ErrorDiag>;
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 5777f7dfbbcad1..df553a47a8dbe7 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10838,9 +10838,9 @@ def note_func_effect_call_func_ptr : Note<
   "'%1' cannot be inferred '%0' because it is a function pointer">;
 
 // TODO: Not currently being generated
-def warn_perf_annotation_implies_noexcept : Warning<
-  "'%0' function should be declared noexcept">,
-  InGroup<PerfAnnotationImpliesNoexcept>;
+// def warn_perf_annotation_implies_noexcept : Warning<
+//  "'%0' function should be declared noexcept">,
+//  InGroup<PerfAnnotationImpliesNoexcept>;
 
 // TODO: Not currently being generated
 def warn_func_effect_false_on_type : Warning<
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 596f4ea2e67176..502c978d5b78e4 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -3517,61 +3517,6 @@ bool FunctionDecl::isMemberLikeConstrainedFriend() const {
   return FriendConstraintRefersToEnclosingTemplate();
 }
 
-static void examine(const Decl& D)
-{
-  PrintingPolicy PP = D.getASTContext().getPrintingPolicy();
-  PP.TerseOutput = 1;
-  D.print(llvm::outs(), PP);
-}
-
-#if TEMP_DISABLE
-// This constant controls the default policy.
-constexpr static bool kDefaultCanInferPerfAnnotation = true;
-
-static bool declCanInferPerfAnnotation(const Decl &D, QualType QT) {
-  // llvm::outs() << "declCanInferPerfAnnotation " << &D << "\n";
-  // examine(D);
-
-  // nolock(false) or noalloc(false) disables inference.
-  if (QT->disallowPerfAnnotationInference()) {
-    // llvm::outs() << "  disallowed by QT\n";
-    return false;
-  }
-  if (auto *IA = D.getAttr<PerformanceInferredAttr>()) {
-    // llvm::outs() << "  decl has attr " << IA->getCanInfer() << "\n";
-    return IA->getCanInfer();
-  }
-  if (auto *Method = dyn_cast<CXXMethodDecl>(&D)) {
-    auto *Class = Method->getParent();
-    if (auto *IA = Class->getAttr<PerformanceInferredAttr>()) {
-      // llvm::outs() << "  class has attr " << IA->getCanInfer() << "\n";
-      return IA->getCanInfer();
-    }
-  }
-
-  // for (const DeclContext *DC = D.getDeclContext(); DC != nullptr; DC = DC->getParent()) {
-  //   if (auto *Decl2 = dyn_cast<Decl>(DC)) {
-  //     examine(*Decl2);
-  //     if (auto *IA = Decl2->getAttr<PerformanceInferredAttr>()) {
-  //       llvm::outs() << "  decl2 has attr " << IA->getCanInfer() << "\n";
-  //       return IA->getCanInfer();
-  //     }
-  //   }
-  // }
-
-  // llvm::outs() << "  result: false\n";
-  return kDefaultCanInferPerfAnnotation;
-}
-
-PerfAnnotation FunctionDecl::getPerfAnnotation() const {
-  return getType()->getPerfAnnotation();
-}
-
-bool FunctionDecl::canInferPerfAnnotation() const {
-  return declCanInferPerfAnnotation(*this, getType());
-}
-#endif // TEMP_DISABLE
-
 MultiVersionKind FunctionDecl::getMultiVersionKind() const {
   if (hasAttr<TargetAttr>())
     return MultiVersionKind::Target;
@@ -5282,35 +5227,14 @@ SourceRange BlockDecl::getSourceRange() const {
 }
 
 FunctionEffectSet BlockDecl::getFunctionEffects() const {
-  if (auto* TSI = getSignatureAsWritten()) {
-    if (auto* FPT = TSI->getType()->getAs<FunctionProtoType>()) {
+  if (auto *TSI = getSignatureAsWritten()) {
+    if (auto *FPT = TSI->getType()->getAs<FunctionProtoType>()) {
       return FPT->getFunctionEffects();
     }
   }
   return {};
 }
 
-#if TEMP_DISABLE
-PerfAnnotation BlockDecl::getPerfAnnotation() const
-{
-  if (auto* TSI = getSignatureAsWritten()) {
-    return TSI->getType()->getPerfAnnotation();
-  }
-  return PerfAnnotation::None;
-}
-#endif // TEMP_DISABLE
-
-#if 0
-// unused
-bool BlockDecl::canInferPerfAnnotation() const
-{
-  if (auto* TSI = getSignatureAsWritten()) {
-    return declCanInferPerfAnnotation(*this, TSI->getType());
-  }
-  return kDefaultCanInferPerfAnnotation;
-}
-#endif
-
 //===----------------------------------------------------------------------===//
 // Other Decl Allocation/Deallocation Method Implementations
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index ce209be2c3a079..998360db3c5dd0 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3694,7 +3694,6 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   ID.AddInteger(unsigned(epi.Variadic) +
                 (epi.RefQualifier << 1) +
                 (epi.ExceptionSpec.Type << 3));
-
   ID.Add(epi.TypeQuals);
   if (epi.ExceptionSpec.Type == EST_Dynamic) {
     for (QualType Ex : epi.ExceptionSpec.Exceptions)
@@ -4924,69 +4923,77 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
           getTypeConstraintConcept(), getTypeConstraintArguments());
 }
 
-
 FunctionEffect::~FunctionEffect() = default;
 
-bool FunctionEffect::diagnoseConversion(bool adding, QualType OldType, FunctionEffectSet OldFX,
-    QualType NewType, FunctionEffectSet NewFX) const
-{
+bool FunctionEffect::diagnoseConversion(bool Adding, QualType OldType,
+                                        FunctionEffectSet OldFX,
+                                        QualType NewType,
+                                        FunctionEffectSet NewFX) const {
   return false;
 }
 
-bool FunctionEffect::diagnoseRedeclaration(bool adding,
-    const FunctionDecl& OldFunction, FunctionEffectSet OldFX,
-    const FunctionDecl& NewFunction, FunctionEffectSet NewFX) const { return false; }
+bool FunctionEffect::diagnoseRedeclaration(bool Adding,
+                                           const FunctionDecl &OldFunction,
+                                           FunctionEffectSet OldFX,
+                                           const FunctionDecl &NewFunction,
+                                           FunctionEffectSet NewFX) const {
+  return false;
+}
 
-bool FunctionEffect::diagnoseMethodOverride(bool adding,
-    const CXXMethodDecl& OldMethod, FunctionEffectSet OldFX,
-    const CXXMethodDecl& NewMethod, FunctionEffectSet NewFX) const { return false; }
+bool FunctionEffect::diagnoseMethodOverride(bool Adding,
+                                            const CXXMethodDecl &OldMethod,
+                                            FunctionEffectSet OldFX,
+                                            const CXXMethodDecl &NewMethod,
+                                            FunctionEffectSet NewFX) const {
+  return false;
+}
 
-bool FunctionEffect::canInferOnDecl(const Decl* Caller, FunctionEffectSet CallerFX) const
-{
+bool FunctionEffect::canInferOnDecl(const Decl *Caller,
+                                    FunctionEffectSet CallerFX) const {
   return false;
 }
 
-bool FunctionEffect::diagnoseFunctionCall(bool direct, 
-    const Decl* Caller, FunctionEffectSet CallerFX,
-    CalleeDeclOrType Callee, FunctionEffectSet CalleeFX) const
-{
+bool FunctionEffect::diagnoseFunctionCall(bool Direct, const Decl *Caller,
+                                          FunctionEffectSet CallerFX,
+                                          CalleeDeclOrType Callee,
+                                          FunctionEffectSet CalleeFX) const {
   return false;
 }
 
-const NoLockNoAllocEffect& NoLockNoAllocEffect::nolock_instance()
-{
+const NoLockNoAllocEffect &NoLockNoAllocEffect::nolock_instance() {
   static NoLockNoAllocEffect global(kNoLockTrue, "nolock");
   return global;
 }
 
-const NoLockNoAllocEffect& NoLockNoAllocEffect::noalloc_instance()
-{
+const NoLockNoAllocEffect &NoLockNoAllocEffect::noalloc_instance() {
   static NoLockNoAllocEffect global(kNoAllocTrue, "noalloc");
   return global;
 }
 
 // TODO: Separate flags for noalloc
-NoLockNoAllocEffect::NoLockNoAllocEffect(EffectType ty, const char* name)
-  : FunctionEffect{ ty, kRequiresVerification | kVerifyCalls | kInferrableOnCallees | kExcludeThrow | kExcludeCatch
-    | kExcludeObjCMessageSend | kExcludeStaticLocalVars | kExcludeThreadLocalVars, name }
-{
-}
+NoLockNoAllocEffect::NoLockNoAllocEffect(EffectType Ty, const char *Name)
+    : FunctionEffect(Ty,
+                     kRequiresVerification | kVerifyCalls |
+                         kInferrableOnCallees | kExcludeThrow | kExcludeCatch |
+                         kExcludeObjCMessageSend | kExcludeStaticLocalVars |
+                         kExcludeThreadLocalVars,
+                     Name) {}
 
 NoLockNoAllocEffect::~NoLockNoAllocEffect() = default;
 
-std::string NoLockNoAllocEffect::attribute() const
-{
-  return std::string{ "__attribute__((clang_" } + name().str() + "))";
+std::string NoLockNoAllocEffect::attribute() const {
+  return std::string{"__attribute__((clang_"} + name().str() + "))";
 }
 
-bool NoLockNoAllocEffect::diagnoseConversion(bool adding, QualType OldType, FunctionEffectSet OldFX,
-    QualType NewType, FunctionEffectSet NewFX) const
-{
+bool NoLockNoAllocEffect::diagnoseConversion(bool adding, QualType OldType,
+                                             FunctionEffectSet OldFX,
+                                             QualType NewType,
+                                             FunctionEffectSet NewFX) const {
   // noalloc can't be added (spoofed) during a conversion, unless we have nolock
   if (adding) {
     if (!isNoLock()) {
-      for (const auto* effect : OldFX) {
-        if (effect->type() == kNoLockTrue)
+      for (const auto *Effect : OldFX) {
+        if (Effect->type() == kNoLockTrue)
           return false;
       }
     }
@@ -4996,29 +5003,29 @@ bool NoLockNoAllocEffect::diagnoseConversion(bool adding, QualType OldType, Func
   return false;
 }
 
-bool NoLockNoAllocEffect::diagnoseRedeclaration(bool adding,
-  const FunctionDecl& OldFunction, FunctionEffectSet OldFX,
-  const FunctionDecl& NewFunction, FunctionEffectSet NewFX) const
-{
+bool NoLockNoAllocEffect::diagnoseRedeclaration(bool Adding,
+                                                const FunctionDecl &OldFunction,
+                                                FunctionEffectSet OldFX,
+                                                const FunctionDecl &NewFunction,
+                                                FunctionEffectSet NewFX) const {
   // nolock/noalloc can't be removed in a redeclaration
   // adding -> false, removing -> true (diagnose)
-  return !adding;
+  return !Adding;
 }
 
-bool NoLockNoAllocEffect::diagnoseMethodOverride(bool adding,
-  const CXXMethodDecl& OldMethod, FunctionEffectSet OldFX,
-  const CXXMethodDecl& NewMethod, FunctionEffectSet NewFX) const
-{
+bool NoLockNoAllocEffect::diagnoseMethodOverride(
+    bool Adding, const CXXMethodDecl &OldMethod, FunctionEffectSet OldFX,
+    const CXXMethodDecl &NewMethod, FunctionEffectSet NewFX) const {
   // nolock/noalloc can't be removed from an override
-  return !adding;
+  return !Adding;
 }
 
-bool NoLockNoAllocEffect::canInferOnDecl(const Decl* Caller, FunctionEffectSet CallerFX) const
-{
+bool NoLockNoAllocEffect::canInferOnDecl(const Decl *Caller,
+                                         FunctionEffectSet CallerFX) const {
   // Does the Decl have nolock(false) / noalloc(false) ?
   QualType QT;
   if (isa<BlockDecl>(Caller)) {
-    const auto* TSI = cast<BlockDecl>(Caller)->getSignatureAsWritten();
+    const auto *TSI = cast<BlockDecl>(Caller)->getSignatureAsWritten();
     QT = TSI->getType();
   } else if (isa<ValueDecl>(Caller)) {
     QT = cast<ValueDecl>(Caller)->getType();
@@ -5032,14 +5039,15 @@ bool NoLockNoAllocEffect::canInferOnDecl(const Decl* Caller, FunctionEffectSet C
   return true;
 }
 
-bool NoLockNoAllocEffect::diagnoseFunctionCall(bool direct, 
-    const Decl* Caller, FunctionEffectSet CallerFX,
-    CalleeDeclOrType Callee, FunctionEffectSet CalleeFX) const
-{
-  const EffectType callerType = type();
-  for (const auto* effect : CalleeFX) {
-    const EffectType ty = effect->type();
-    if (ty == callerType || (callerType == kNoAllocTrue && ty == kNoLockTrue)) {
+// TODO: Notice that we don't care about some of the parameters. Is the
+// interface overly general?
+bool NoLockNoAllocEffect::diagnoseFunctionCall(
+    bool Direct, const Decl *Caller, FunctionEffectSet CallerFX,
+    CalleeDeclOrType Callee, FunctionEffectSet CalleeFX) const {
+  const EffectType CallerType = type();
+  for (const auto *Effect : CalleeFX) {
+    const EffectType ET = Effect->type();
+    if (ET == CallerType || (CallerType == kNoAllocTrue && ET == kNoLockTrue)) {
       return false;
     }
   }
@@ -5048,142 +5056,145 @@ bool NoLockNoAllocEffect::diagnoseFunctionCall(bool direct,
 
 // =====
 
-void MutableFunctionEffectSet::insert(const FunctionEffect* effect)
-{
-  auto iter = std::lower_bound(begin(), end(), effect);
-  if (*iter != effect) {
-    insert(iter, effect);
+void MutableFunctionEffectSet::insert(const FunctionEffect *Effect) {
+  auto Iter = std::lower_bound(begin(), end(), Effect);
+  if (*Iter != Effect) {
+    insert(Iter, Effect);
   }
 }
 
-MutableFunctionEffectSet& MutableFunctionEffectSet::operator|=(FunctionEffectSet rhs)
-{
-  // TODO: For large rhs sets, use set_union or a custom insert-in-place
-  for (const auto* effect : rhs) {
-    insert(effect);
+MutableFunctionEffectSet &
+MutableFunctionEffectSet::operator|=(FunctionEffectSet RHS) {
+  // TODO: For large RHS sets, use set_union or a custom insert-in-place
+  for (const auto *Effect : RHS) {
+    insert(Effect);
   }
   return *this;
 }
 
-// This could be simpler if there were a simple set container that could be queried by
-// ArrayRef but which stored something else. Possibly a DenseMap with void values?
-FunctionEffectSet FunctionEffectSet::create(llvm::ArrayRef<const FunctionEffect*> items)
-{
-  if (items.empty()) {
+// This could be simpler if there were a simple set container that could be
+// queried by ArrayRef but which stored something else. Possibly a DenseMap with
+// void values?
+FunctionEffectSet
+FunctionEffectSet::create(llvm::ArrayRef<const FunctionEffect *> Items) {
+  if (Items.empty()) {
     return FunctionEffectSet{};
   }
-  if (items.size() == 1) {
-    return FunctionEffectSet{ items[0] };
+  if (Items.size() == 1) {
+    return FunctionEffectSet{Items[0]};
   }
 
-  UniquedAndSortedFX newSet{ items }; // just copies the ArrayRef
+  UniquedAndSortedFX NewSet(Items); // just copies the ArrayRef
 
-  // SmallSet only has contains(), so it provides no way to obtain the uniqued value.
+  // SmallSet only has contains(), so it provides no way to obtain the uniqued
+  // value.
   static std::set<UniquedAndSortedFX> uniquedFXSets;
 
   // See if we already have this set.
-  const auto iter = uniquedFXSets.find(newSet);
-  if (iter != uniquedFXSets.end()) {
-    return FunctionEffectSet{ &*iter };
+  const auto Iter = uniquedFXSets.find(NewSet);
+  if (Iter != uniquedFXSets.end()) {
+    return FunctionEffectSet{&*Iter};
   }
 
   // Copy the incoming array to permanent storage.
-  auto* storage = new const FunctionEffect*[items.size()];
-  std::copy(items.begin(), items.end(), storage);
+  auto *Storage = new const FunctionEffect *[Items.size()];
+  std::copy(Items.begin(), Items.end(), Storage);
 
   // Make a new wrapper and insert it into the set.
-  newSet = UniquedAndSortedFX{ storage, items.size() };
-  auto [insiter, good] = uniquedFXSets.insert(newSet);
-  return FunctionEffectSet{ &*insiter };
+  NewSet = UniquedAndSortedFX(Storage, Items.size());
+  auto [InsIter, _] = uniquedFXSets.insert(NewSet);
+  return FunctionEffectSet(&*InsIter);
 }
 
-FunctionEffectSet FunctionEffectSet::operator|(const FunctionEffectSet& rhs) const
-{
-  const FunctionEffectSet& lhs = *this;
-  if (lhs.empty()) {
-    return rhs;
-  }
-  if (rhs.empty()) {
-    return lhs;
-  }
+FunctionEffectSet
+FunctionEffectSet::operator|(const FunctionEffectSet &RHS) const {
+  // Optimize for one of the two sets being empty
+  const FunctionEffectSet &LHS = *this;
+  if (LHS.empty())
+    return RHS;
+  if (RHS.empty())
+    return LHS;
+
   // Optimize the case where the two sets are identical
-  if (lhs == rhs) {
-    return lhs;
-  }
+  if (LHS == RHS)
+    return LHS;
 
-  MutableFunctionEffectSet vec;
-  vec.reserve(lhs.size() + rhs.size());
-  std::set_union(lhs.begin(), lhs.end(), rhs.begin(), rhs.end(), std::back_inserter(vec));
+  MutableFunctionEffectSet Vec;
+  Vec.reserve(LHS.size() + RHS.size());
+  std::set_union(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
+                 std::back_inserter(Vec));
   // The result of a set operation is an ordered/unique set.
-  return FunctionEffectSet::create(vec);
+  return FunctionEffectSet::create(Vec);
 }
 
-MutableFunctionEffectSet FunctionEffectSet::operator&(const FunctionEffectSet& rhs) const
-{
-  const FunctionEffectSet& lhs = *this;
-  if (lhs.empty() || rhs.empty()) {
+MutableFunctionEffectSet
+FunctionEffectSet::operator&(const FunctionEffectSet &RHS) const {
+  const FunctionEffectSet &LHS = *this;
+  if (LHS.empty() || RHS.empty()) {
     return {};
   }
 
-  MutableFunctionEffectSet vec;
-  std::set_intersection(lhs.begin(), lhs.end(), rhs.begin(), rhs.end(), std::back_inserter(vec));
+  MutableFunctionEffectSet Vec;
+  std::set_intersection(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
+                        std::back_inserter(Vec));
   // The result of a set operation is an ordered/unique set.
-  return vec;
+  return Vec;
 }
 
 // TODO: inline?
-FunctionEffectSet FunctionEffectSet::get(const Type& TyRef)
-{
-  const Type* Ty = &TyRef;      
+FunctionEffectSet FunctionEffectSet::get(const Type &TyRef) {
+  const Type *Ty = &TyRef;
   if (Ty->isPointerType())
     Ty = Ty->getPointeeType().getTypePtr();
-  if (const auto* FPT = Ty->getAs<FunctionProtoType>())
+  if (const auto *FPT = Ty->getAs<FunctionProtoType>())
     return FPT->getFunctionEffects();
   return {};
 }
 
-FunctionEffectSet::Differences FunctionEffectSet::differences(
-    const FunctionEffectSet& Old, const FunctionEffectSet& New)
-{
+FunctionEffectSet::Differences
+FunctionEffectSet::differences(const FunctionEffectSet &Old,
+                               const FunctionEffectSet &New) {
   // TODO: Could be a one-pass algorithm.
-  Differences result;
-  for (const auto* effect : (New - Old)) {
-    result.emplace_back(effect, true);
+  Differences Result;
+  for (const auto *Effect : (New - Old)) {
+    Result.emplace_back(Effect, true);
   }
-  for (const auto* effect : (Old - New)) {
-    result.emplace_back(effect, false);
+  for (const auto *Effect : (Old - New)) {
+    Result.emplace_back(Effect, false);
   }
-  return result;
+  return Result;
 }
 
-MutableFunctionEffectSet FunctionEffectSet::operator-(const FunctionEffectSet& rhs) const
-{
-  const FunctionEffectSet& lhs = *this;
-  MutableFunctionEffectSet result;
+MutableFunctionEffectSet
+FunctionEffectSet::operator-(const FunctionEffectSet &RHS) const {
+  const FunctionEffectSet &LHS = *this;
+  MutableFunctionEffectSet Result;
 
-  std::set_difference(lhs.begin(), lhs.end(), rhs.begin(), rhs.end(), std::back_inserter(result));
-  return result;
+  std::set_difference(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
+                      std::back_inserter(Result));
+  return Result;
 }
 
-bool FunctionEffectSet::operator<(const FunctionEffectSet& rhs) const
-{
-  const FunctionEffectSet& lhs = *this;
-  return std::lexicographical_compare(lhs.begin(), lhs.end(), rhs.begin(), rhs.end());
+bool FunctionEffectSet::operator<(const FunctionEffectSet &RHS) const {
+  const FunctionEffectSet &LHS = *this;
+  return std::lexicographical_compare(LHS.begin(), LHS.end(), RHS.begin(),
+                                      RHS.end());
 }
 
-bool FunctionEffectSet::UniquedAndSortedFX::operator<(const UniquedAndSortedFX& rhs) const
-{
-  return this < &rhs;
+bool FunctionEffectSet::UniquedAndSortedFX::operator<(
+    const UniquedAndSortedFX &RHS) const {
+  return this < &RHS;
 }
 
-void FunctionEffectSet::dump(llvm::raw_ostream &OS) const
-{
+void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
   OS << "FX{";
-  bool first = true;
-  for (const auto* effect : *this) {
-    if (!first) OS << ", ";
-    else first = false;
-    OS << effect->name();
+  bool First = true;
+  for (const auto *Effect : *this) {
+    if (!First)
+      OS << ", ";
+    else
+      First = false;
+    OS << Effect->name();
   }
   OS << "}";
 }
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 560f2faeb9e503..252a5dfbc952b0 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -984,12 +984,11 @@ void TypePrinter::printFunctionProtoAfter(const FunctionProtoType *T,
     OS << " &&";
     break;
   }
-
   T->printExceptionSpecification(OS, Policy);
 
-  if (auto effects = T->getFunctionEffects()) {
-    for (const auto* effect : effects) {
-      OS << " " << effect->attribute();
+  if (const FunctionEffectSet FX = T->getFunctionEffects()) {
+    for (const auto *Effect : FX) {
+      OS << " " << Effect->attribute();
     }
   }
 
@@ -1911,7 +1910,6 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   case attr::AArch64SVEPcs: OS << "aarch64_sve_pcs"; break;
   case attr::AMDGPUKernelCall: OS << "amdgpu_kernel"; break;
   case attr::IntelOclBicc: OS << "inteloclbicc"; break;
-
   case attr::PreserveMost:
     OS << "preserve_most";
     break;
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index a0d813fa4d3d14..69417b10049e97 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -27,6 +27,8 @@
 #include "clang/AST/StmtObjC.h"
 #include "clang/AST/StmtVisitor.h"
 #include "clang/AST/Type.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
 #include "clang/Analysis/Analyses/CFGReachabilityAnalysis.h"
 #include "clang/Analysis/Analyses/CalledOnceCheck.h"
 #include "clang/Analysis/Analyses/Consumed.h"
@@ -2382,6 +2384,7 @@ class UnsafeBufferUsageReporter : public UnsafeBufferUsageHandler {
 
 // =============================================================================
 
+// Temporary debugging option
 #define FX_ANALYZER_VERIFY_DECL_LIST 1
 
 namespace FXAnalysis {
@@ -2396,41 +2399,37 @@ enum class DiagnosticID : uint8_t {
   AccessesThreadLocal,
 
   // These only apply to callees, where the analysis stops at the Decl
-  // DeclExternWithoutConstraint, // TODO: not used?
   DeclWithoutConstraintOrInference,
-  //DeclVirtualWithoutConstraint,
-  //DeclFuncPtrWithoutConstraint,
 
   CallsUnsafeDecl,
   CallsDisallowedExpr,
 };
 
 struct Diagnostic {
-  const FunctionEffect* Effect = nullptr;
-  const Decl* Callee = nullptr; // only valid for Calls*
-  SourceLocation Loc{};
-  DiagnosticID ID{ DiagnosticID::None };
+  const FunctionEffect *Effect = nullptr;
+  const Decl *Callee = nullptr; // only valid for Calls*
+  SourceLocation Loc;
+  DiagnosticID ID = DiagnosticID::None;
 
   Diagnostic() = default;
 
-  Diagnostic(const FunctionEffect *Effect, DiagnosticID ID, SourceLocation Loc, const Decl* Callee = nullptr)
-    : Effect{ Effect }, Callee{ Callee }, Loc{ Loc }, ID{ ID }
-  {
-  }
+  Diagnostic(const FunctionEffect *Effect, DiagnosticID ID, SourceLocation Loc,
+             const Decl *Callee = nullptr)
+      : Effect(Effect), Callee(Callee), Loc(Loc), ID(ID) {}
 };
 
-enum class SpecialFuncType : uint8_t {
-  None, OperatorNew, OperatorDelete
-};
+enum class SpecialFuncType : uint8_t { None, OperatorNew, OperatorDelete };
 enum class CallType {
-  Unknown, Function, Virtual, Block
+  Unknown,
+  Function,
+  Virtual,
+  Block
   // unknown: probably function pointer
 };
 
 // Return whether the function CAN be verified.
 // The question of whether it SHOULD be verified is independent.
-static bool functionIsVerifiable(const FunctionDecl* FD)
-{
+static bool functionIsVerifiable(const FunctionDecl *FD) {
   if (!(FD->hasBody() || FD->isInlined())) {
     // externally defined; we couldn't verify if we wanted to.
     return false;
@@ -2443,45 +2442,37 @@ static bool functionIsVerifiable(const FunctionDecl* FD)
   return true;
 }
 
-// Transitory, more extended information about a callable, which can be a function,
-// block, function pointer...
+// Transitory, more extended information about a callable, which can be a
+// function, block, function pointer...
 struct CallableInfo {
-  const Decl* CDecl;
-  mutable std::optional<std::string> MaybeName; // mutable because built on demand in const method
-  SpecialFuncType FuncType{ SpecialFuncType::None };
+  const Decl *CDecl;
+  mutable std::optional<std::string>
+      MaybeName; // mutable because built on demand in const method
+  SpecialFuncType FuncType = SpecialFuncType::None;
   FunctionEffectSet Effects;
-  CallType CType{ CallType::Unknown };
-  // bool IsAllowListed{ false };
+  CallType CType = CallType::Unknown;
 
-  CallableInfo(const Decl& CD, SpecialFuncType FT = SpecialFuncType::None)
-    : CDecl{ &CD }, FuncType{ FT }
-  {
-    //llvm::errs() << "CallableInfo " << name() << "\n";
+  CallableInfo(const Decl &CD, SpecialFuncType FT = SpecialFuncType::None)
+      : CDecl(&CD), FuncType(FT) {
+    // llvm::errs() << "CallableInfo " << name() << "\n";
 
-    if (auto* FD = dyn_cast<FunctionDecl>(CDecl)) {
+    if (auto *FD = dyn_cast<FunctionDecl>(CDecl)) {
       assert(FD->getCanonicalDecl() == FD);
       // Use the function's definition, if any.
-      if (auto* Def = FD->getDefinition()) {
+      if (auto *Def = FD->getDefinition()) {
         CDecl = FD = Def;
       }
       CType = CallType::Function;
-      if (auto* Method = dyn_cast<CXXMethodDecl>(FD)) {
+      if (auto *Method = dyn_cast<CXXMethodDecl>(FD)) {
         if (Method->isVirtual()) {
           CType = CallType::Virtual;
         }
       }
       Effects = FD->getFunctionEffects();
-
-      // TODO: Generalize via noreturn??? but that would cover exceptions too.
-      // if (name() == "__assert_rtn") {
-      //   // big hack because it's hard to get the attribute to stick on it
-      //   // through a redeclaration, not sure why.
-      //   IsAllowListed = true;
-      // }
-    } else if (auto* BD = dyn_cast<BlockDecl>(CDecl)) {
+    } else if (auto *BD = dyn_cast<BlockDecl>(CDecl)) {
       CType = CallType::Block;
       Effects = BD->getFunctionEffects();
-    } else if (auto* VD = dyn_cast<ValueDecl>(CDecl)) {
+    } else if (auto *VD = dyn_cast<ValueDecl>(CDecl)) {
       // ValueDecl is function, enum, or variable, so just look at the type.
       Effects = FunctionEffectSet::get(*VD->getType());
     }
@@ -2491,8 +2482,7 @@ struct CallableInfo {
     return CType == CallType::Function || CType == CallType::Block;
   }
 
-  bool isVerifiable() const
-  {
+  bool isVerifiable() const {
     switch (CType) {
     case CallType::Unknown:
     case CallType::Virtual:
@@ -2505,19 +2495,18 @@ struct CallableInfo {
     return false;
   }
 
-  /// Generate a name for logging.
-  std::string name(Sema& sema) const
-  {
+  /// Generate a name for logging and diagnostics.
+  std::string name(Sema &Sem) const {
     if (!MaybeName) {
       std::string Name;
       llvm::raw_string_ostream OS(Name);
 
-      if (auto* FD = dyn_cast<FunctionDecl>(CDecl)) {
-        FD->getNameForDiagnostic(OS, sema.getPrintingPolicy(),
-                                    /*Qualified=*/true);
-      } else if (auto* BD = dyn_cast<BlockDecl>(CDecl)) {
+      if (auto *FD = dyn_cast<FunctionDecl>(CDecl)) {
+        FD->getNameForDiagnostic(OS, Sem.getPrintingPolicy(),
+                                 /*Qualified=*/true);
+      } else if (auto *BD = dyn_cast<BlockDecl>(CDecl)) {
         OS << "(block " << BD->getBlockManglingNumber() << ")";
-      } else if (auto* VD = dyn_cast<NamedDecl>(CDecl)) {
+      } else if (auto *VD = dyn_cast<NamedDecl>(CDecl)) {
         VD->printQualifiedName(OS);
       }
       MaybeName = Name;
@@ -2529,35 +2518,34 @@ struct CallableInfo {
 // ----------
 // Map effects to single diagnostics.
 class EffectToDiagnosticMap {
-  // Since we currently only have a tiny number of effects (typically no more than 1),
-  // use a sorted SmallVector.
-  using Element = std::pair<const FunctionEffect*, Diagnostic>;
+  // Since we currently only have a tiny number of effects (typically no more
+  // than 1), use a sorted SmallVector.
+  using Element = std::pair<const FunctionEffect *, Diagnostic>;
   using ImplVec = llvm::SmallVector<Element>;
   std::unique_ptr<ImplVec> Impl;
+
 public:
-  Diagnostic& getOrInsertDefault(const FunctionEffect* key)
-  {
+  Diagnostic &getOrInsertDefault(const FunctionEffect *Key) {
     if (Impl == nullptr) {
       Impl = std::make_unique<llvm::SmallVector<Element>>();
-      auto& item = Impl->emplace_back();
-      item.first = key;
-      return item.second;
+      auto &Item = Impl->emplace_back();
+      Item.first = Key;
+      return Item.second;
     }
-    Element elem{ key, {} };
-    auto iter = _find(elem);
-    if (iter != Impl->end() && iter->first == key) {
-      return iter->second;
+    Element Elem(Key, {});
+    auto Iter = _find(Elem);
+    if (Iter != Impl->end() && Iter->first == Key) {
+      return Iter->second;
     }
-    iter = Impl->insert(iter, elem);
-    return iter->second;
+    Iter = Impl->insert(Iter, Elem);
+    return Iter->second;
   }
 
-  const Diagnostic* lookup(const FunctionEffect* key)
-  {
+  const Diagnostic *lookup(const FunctionEffect *key) {
     if (Impl == nullptr) {
       return nullptr;
     }
-    Element elem{ key, {} };
+    Element elem(key, {});
     auto iter = _find(elem);
     if (iter != Impl->end() && iter->first == key) {
       return &iter->second;
@@ -2568,23 +2556,23 @@ class EffectToDiagnosticMap {
   size_t size() const { return Impl ? Impl->size() : 0; }
 
 private:
-  ImplVec::iterator _find(const Element& elem)
-  {
-    return std::lower_bound(Impl->begin(), Impl->end(), elem, [](const Element& lhs, const Element& rhs) {
-      return lhs.first < rhs.first;
-    });
+  ImplVec::iterator _find(const Element &elem) {
+    return std::lower_bound(Impl->begin(), Impl->end(), elem,
+                            [](const Element &lhs, const Element &rhs) {
+                              return lhs.first < rhs.first;
+                            });
   }
 };
 
 // ----------
-// State pertaining to a function whose AST is walked. Since there are potentially a large
-// number of these objects, it needs care about size.
+// State pertaining to a function whose AST is walked. Since there are
+// potentially a large number of these objects, it needs care about size.
 class PendingFunctionAnalysis {
   // Current size: 5 pointers
   friend class CompleteFunctionAnalysis;
 
   struct DirectCall {
-    const Decl* Callee;
+    const Decl *Callee;
     SourceLocation CallLoc;
   };
 
@@ -2596,21 +2584,22 @@ class PendingFunctionAnalysis {
   FunctionEffectSet FXToInfer;
 
 private:
-  // Diagnostics pertaining to the function's explicit effects. Use a unique_ptr to optimize
-  // size for the case of 0 diagnostics.
+  // Diagnostics pertaining to the function's explicit effects. Use a unique_ptr
+  // to optimize size for the case of 0 diagnostics.
   std::unique_ptr<SmallVector<Diagnostic>> DiagnosticsForExplicitFX;
 
-  // Potential diagnostics pertaining to other, non-explicit, inferrable effects.
+  // Potential diagnostics pertaining to other, non-explicit, inferrable
+  // effects.
   EffectToDiagnosticMap InferrableEffectToFirstDiagnostic;
 
   std::unique_ptr<SmallVector<DirectCall>> UnverifiedDirectCalls;
 
 public:
-  PendingFunctionAnalysis(const CallableInfo& cinfo, FunctionEffectSet AllInferrableEffectsToVerify)
-  {
+  PendingFunctionAnalysis(const CallableInfo &cinfo,
+                          FunctionEffectSet AllInferrableEffectsToVerify) {
     MutableFunctionEffectSet fx;
-    for (const auto* effect : cinfo.Effects) {
-      if (effect->getFlags() & FunctionEffect::kRequiresVerification) {
+    for (const auto *effect : cinfo.Effects) {
+      if (effect->flags() & FunctionEffect::kRequiresVerification) {
         fx.insert(effect);
       }
     }
@@ -2618,71 +2607,73 @@ class PendingFunctionAnalysis {
 
     // Check for effects we are not allowed to infer
     fx.clear();
-    for (const auto* effect : AllInferrableEffectsToVerify) {
+    for (const auto *effect : AllInferrableEffectsToVerify) {
       if (effect->canInferOnDecl(cinfo.CDecl, cinfo.Effects)) {
         fx.insert(effect);
       } else {
         // Add a diagnostic for this effect if a caller were to
         // try to infer it.
-        auto& diag = InferrableEffectToFirstDiagnostic.getOrInsertDefault(effect);
-        diag = Diagnostic{ effect, DiagnosticID::DeclWithoutConstraintOrInference,
-          cinfo.CDecl->getLocation() };
+        auto &diag =
+            InferrableEffectToFirstDiagnostic.getOrInsertDefault(effect);
+        diag =
+            Diagnostic(effect, DiagnosticID::DeclWithoutConstraintOrInference,
+                       cinfo.CDecl->getLocation());
       }
     }
     // fx is now the set of inferrable effects which are not prohibited
-    FXToInfer = FunctionEffectSet::create(FunctionEffectSet::create(fx) - DeclaredVerifiableEffects);
+    FXToInfer = FunctionEffectSet::create(FunctionEffectSet::create(fx) -
+                                          DeclaredVerifiableEffects);
   }
 
-  void checkAddDiagnostic(bool inferring, const Diagnostic& NewDiag)
-  {
-    if (!inferring) {
+  // Hide the way that diagnostics for explicitly required effects vs. inferred
+  // ones are handled differently.
+  void checkAddDiagnostic(bool Inferring, const Diagnostic &NewDiag) {
+    if (!Inferring) {
       if (DiagnosticsForExplicitFX == nullptr) {
         DiagnosticsForExplicitFX = std::make_unique<SmallVector<Diagnostic>>();
       }
       DiagnosticsForExplicitFX->push_back(NewDiag);
     } else {
-      auto& diag = InferrableEffectToFirstDiagnostic.getOrInsertDefault(NewDiag.Effect);
-      if (diag.ID == DiagnosticID::None) {
-        diag = NewDiag;
+      auto &Diag =
+          InferrableEffectToFirstDiagnostic.getOrInsertDefault(NewDiag.Effect);
+      if (Diag.ID == DiagnosticID::None) {
+        Diag = NewDiag;
       }
     }
   }
 
-  void addUnverifiedDirectCall(const Decl* D, SourceLocation CallLoc)
-  {
+  void addUnverifiedDirectCall(const Decl *D, SourceLocation CallLoc) {
     if (UnverifiedDirectCalls == nullptr) {
       UnverifiedDirectCalls = std::make_unique<SmallVector<DirectCall>>();
     }
-    UnverifiedDirectCalls->emplace_back(DirectCall{ D, CallLoc });
+    UnverifiedDirectCalls->emplace_back(DirectCall{D, CallLoc});
   }
 
   // Analysis is complete when there are no unverified direct calls.
-  bool isComplete() const
-  {
+  bool isComplete() const {
     return UnverifiedDirectCalls == nullptr || UnverifiedDirectCalls->empty();
   }
 
-  const Diagnostic* diagnosticForInferrableEffect(const FunctionEffect* effect)
-  {
+  const Diagnostic *
+  diagnosticForInferrableEffect(const FunctionEffect *effect) {
     return InferrableEffectToFirstDiagnostic.lookup(effect);
   }
 
-  const SmallVector<DirectCall>& unverifiedCalls() const
-  {
+  const SmallVector<DirectCall> &unverifiedCalls() const {
     assert(!isComplete());
     return *UnverifiedDirectCalls;
   }
 
-  SmallVector<Diagnostic>* getDiagnosticsForExplicitFX() const
-  {
+  SmallVector<Diagnostic> *getDiagnosticsForExplicitFX() const {
     return DiagnosticsForExplicitFX.get();
   }
 
-  void dump(llvm::raw_ostream& OS) const
-  {
+  void dump(llvm::raw_ostream &OS) const {
     OS << "Pending: Declared ";
     DeclaredVerifiableEffects.dump(OS);
-    OS << ", " << (DiagnosticsForExplicitFX ? DiagnosticsForExplicitFX->size() : 0) << " diags; ";
+    OS << ", "
+       << (DiagnosticsForExplicitFX ? DiagnosticsForExplicitFX->size() : 0)
+       << " diags; ";
     OS << " Infer ";
     FXToInfer.dump(OS);
     OS << ", " << InferrableEffectToFirstDiagnostic.size() << " diags\n";
@@ -2693,10 +2684,10 @@ class PendingFunctionAnalysis {
 class CompleteFunctionAnalysis {
   // Current size: 2 pointers
 public:
-  // Has effects which are both the declared ones -- not to be inferred -- plus ones which
-  // have been successfully inferred. These are all considered "verified" for the purposes
-  // of callers; any issue with verifying declared effects has already been reported and
-  // is not the problem of any caller.
+  // Has effects which are both the declared ones -- not to be inferred -- plus
+  // ones which have been successfully inferred. These are all considered
+  // "verified" for the purposes of callers; any issue with verifying declared
+  // effects has already been reported and is not the problem of any caller.
   FunctionEffectSet VerifiedEffects;
 
 private:
@@ -2704,28 +2695,28 @@ class CompleteFunctionAnalysis {
   EffectToDiagnosticMap InferrableEffectToFirstDiagnostic;
 
 public:
-  CompleteFunctionAnalysis(PendingFunctionAnalysis& pending, FunctionEffectSet funcFX, FunctionEffectSet AllInferrableEffectsToVerify)
-  {
+  CompleteFunctionAnalysis(PendingFunctionAnalysis &pending,
+                           FunctionEffectSet funcFX,
+                           FunctionEffectSet AllInferrableEffectsToVerify) {
     MutableFunctionEffectSet verified;
     verified |= funcFX;
-    for (const auto* effect : AllInferrableEffectsToVerify) {
+    for (const auto *effect : AllInferrableEffectsToVerify) {
       if (pending.diagnosticForInferrableEffect(effect) == nullptr) {
         verified.insert(effect);
       }
     }
     VerifiedEffects = FunctionEffectSet::create(verified);
 
-    InferrableEffectToFirstDiagnostic = std::move(pending.InferrableEffectToFirstDiagnostic);
+    InferrableEffectToFirstDiagnostic =
+        std::move(pending.InferrableEffectToFirstDiagnostic);
   }
 
-  const Diagnostic* firstDiagnosticForEffect(const FunctionEffect* effect)
-  {
+  const Diagnostic *firstDiagnosticForEffect(const FunctionEffect *effect) {
     // TODO: is this correct?
     return InferrableEffectToFirstDiagnostic.lookup(effect);
   }
 
-  void dump(llvm::raw_ostream& OS) const
-  {
+  void dump(llvm::raw_ostream &OS) const {
     OS << "Complete: Verified ";
     VerifiedEffects.dump(OS);
     OS << "; Infer ";
@@ -2734,11 +2725,11 @@ class CompleteFunctionAnalysis {
 };
 
 /*
-	TODO: nolock and noalloc imply noexcept
+        TODO: nolock and noalloc imply noexcept
         if (auto* Method = dyn_cast<CXXMethodDecl>(CInfo.CDecl)) {
           if (Method->getType()->castAs<FunctionProtoType>()->canThrow()
               != clang::CT_Cannot) {
-            S.Diag(Callable->getBeginLoc(), 
+            S.Diag(Callable->getBeginLoc(),
               diag::warn_perf_annotation_implies_noexcept)
               << getPerfAnnotationSpelling(CInfo.PerfAnnot);
           }
@@ -2750,7 +2741,7 @@ class Analyzer {
   constexpr static int kDebugLogLevel = 3;
 
   // --
-  Sema& mSema;
+  Sema &Sem;
 
   // used from Sema:
   //  SmallVector<const Decl *> DeclsWithUnverifiedEffects
@@ -2758,78 +2749,76 @@ class Analyzer {
   // Subset of Sema.AllEffectsToVerify
   FunctionEffectSet AllInferrableEffectsToVerify;
 
-  using FuncAnalysisPtr = llvm::PointerUnion<PendingFunctionAnalysis*, CompleteFunctionAnalysis*>;
+  using FuncAnalysisPtr =
+      llvm::PointerUnion<PendingFunctionAnalysis *, CompleteFunctionAnalysis *>;
 
-  // Map all Decls analyzed to FuncAnalysisPtr. Pending state is larger 
+  // Map all Decls analyzed to FuncAnalysisPtr. Pending state is larger
   // than complete state, so use different objects to represent them.
   // The state pointers are owned by the container.
-  struct AnalysisMap : public llvm::DenseMap<const Decl*, FuncAnalysisPtr> {
-  
+  struct AnalysisMap : public llvm::DenseMap<const Decl *, FuncAnalysisPtr> {
+
     ~AnalysisMap();
 
     // use lookup()
 
-    CompleteFunctionAnalysis* completedAnalysisForDecl(const Decl* D) const
-    {
+    /// Shortcut for the case where we only care about completed analysis.
+    CompleteFunctionAnalysis *completedAnalysisForDecl(const Decl *D) const {
       if (auto AP = lookup(D)) {
-        if (isa<CompleteFunctionAnalysis*>(AP)) {
-          return AP.get<CompleteFunctionAnalysis*>();
+        if (isa<CompleteFunctionAnalysis *>(AP)) {
+          return AP.get<CompleteFunctionAnalysis *>();
         }
       }
       return nullptr;
     }
 
-    void dump(Sema& S, llvm::raw_ostream& OS)
-    {
+    void dump(Sema &S, llvm::raw_ostream &OS) {
       OS << "AnalysisMap:\n";
-      for (const auto& item : *this) {
-        CallableInfo CI{ *item.first };
+      for (const auto &item : *this) {
+        CallableInfo CI(*item.first);
         const auto AP = item.second;
         OS << item.first << " " << CI.name(S) << " : ";
         if (AP.isNull()) {
           OS << "null\n";
-        } else if (isa<CompleteFunctionAnalysis*>(AP)) {
-          auto* CFA = AP.get<CompleteFunctionAnalysis*>();
+        } else if (isa<CompleteFunctionAnalysis *>(AP)) {
+          auto *CFA = AP.get<CompleteFunctionAnalysis *>();
           OS << CFA << " ";
           CFA->dump(OS);
-        } else if (isa<PendingFunctionAnalysis*>(AP)) {
-          auto* PFA = AP.get<PendingFunctionAnalysis*>();
+        } else if (isa<PendingFunctionAnalysis *>(AP)) {
+          auto *PFA = AP.get<PendingFunctionAnalysis *>();
           OS << PFA << " ";
           PFA->dump(OS);
-        } else llvm_unreachable("never");
+        } else
+          llvm_unreachable("never");
       }
     }
   };
   AnalysisMap DeclAnalysis;
 
 public:
-  Analyzer(Sema& S)
-    : mSema{ S }
-  {
-  }
+  Analyzer(Sema &S) : Sem(S) {}
 
-  void run(const TranslationUnitDecl& TU)
-  {
+  void run(const TranslationUnitDecl &TU) {
 #if FX_ANALYZER_VERIFY_DECL_LIST
     verifyRootDecls(TU);
 #endif
-    // Gather all of the effects to be verified to see what operations need to be checked,
-    // and to see which ones are inferrable.
+    // Gather all of the effects to be verified to see what operations need to
+    // be checked, and to see which ones are inferrable.
     {
       MutableFunctionEffectSet inferrableEffects;
-      for (const FunctionEffect* effect : mSema.AllEffectsToVerify) {
-        const auto Flags = effect->getFlags();
+      for (const FunctionEffect *effect : Sem.AllEffectsToVerify) {
+        const auto Flags = effect->flags();
         if (Flags & FunctionEffect::kInferrableOnCallees) {
           inferrableEffects.insert(effect);
         }
       }
-      AllInferrableEffectsToVerify = FunctionEffectSet::create(inferrableEffects);
+      AllInferrableEffectsToVerify =
+          FunctionEffectSet::create(inferrableEffects);
       llvm::outs() << "AllInferrableEffectsToVerify: ";
       AllInferrableEffectsToVerify.dump(llvm::outs());
       llvm::outs() << "\n";
     }
 
-    SmallVector<const Decl*>& verifyQueue = mSema.DeclsWithUnverifiedEffects;
+    SmallVector<const Decl *> &verifyQueue = Sem.DeclsWithUnverifiedEffects;
 
     // It's useful to use DeclsWithUnverifiedEffects as a stack for a
     // depth-first traversal rather than have a secondary container. But first,
@@ -2837,40 +2826,40 @@ class Analyzer {
     std::reverse(verifyQueue.begin(), verifyQueue.end());
 
     while (!verifyQueue.empty()) {
-      const Decl* D = verifyQueue.back();
+      const Decl *D = verifyQueue.back();
       if (auto AP = DeclAnalysis.lookup(D)) {
-          if (isa<CompleteFunctionAnalysis*>(AP)) {
-            // already done
-            verifyQueue.pop_back();
-            continue;
-          }
-          if (isa<PendingFunctionAnalysis*>(AP)) {
-            // All children have been traversed; finish analysis.
-            auto* pending = AP.get<PendingFunctionAnalysis*>();
-            finishPendingAnalysis(D, pending);
-            verifyQueue.pop_back();
-            continue;
-          }
-          llvm_unreachable("shouldn't happen");
+        if (isa<CompleteFunctionAnalysis *>(AP)) {
+          // already done
+          verifyQueue.pop_back();
+          continue;
+        }
+        if (isa<PendingFunctionAnalysis *>(AP)) {
+          // All children have been traversed; finish analysis.
+          auto *pending = AP.get<PendingFunctionAnalysis *>();
+          finishPendingAnalysis(D, pending);
+          verifyQueue.pop_back();
+          continue;
+        }
+        llvm_unreachable("shouldn't happen");
       }
 
-      auto* pending = verifyDecl(D);
-      if (pending == nullptr) {
+      auto *Pending = verifyDecl(D);
+      if (Pending == nullptr) {
         // completed now
         verifyQueue.pop_back();
         continue;
       }
 
-      for (const auto& call : pending->unverifiedCalls()) {
-        // This lookup could be optimized out if the results could have been saved
-        // from followCall when we traversed the caller's AST. It would however
-        // make the check for recursion more complex.
-        auto AP = DeclAnalysis.lookup(call.Callee);
+      for (const auto &Call : Pending->unverifiedCalls()) {
+        // This lookup could be optimized out if the results could have been
+        // saved from followCall when we traversed the caller's AST. It would
+        // however make the check for recursion more complex.
+        auto AP = DeclAnalysis.lookup(Call.Callee);
         if (AP.isNull()) {
-          verifyQueue.push_back(call.Callee);
+          verifyQueue.push_back(Call.Callee);
           continue;
         }
-        if (isa<PendingFunctionAnalysis*>(AP)) {
+        if (isa<PendingFunctionAnalysis *>(AP)) {
           // $$$$$$$$$$$$$$$$$$$$$$$ recursion $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
           __builtin_trap();
         }
@@ -2880,38 +2869,28 @@ class Analyzer {
   }
 
 private:
-  // Verify a single Decl. Return the pending structure if that was the result, else null.
-  // This method must not recurse.
-  PendingFunctionAnalysis* verifyDecl(const Decl *D)
-  {
+  // Verify a single Decl. Return the pending structure if that was the result,
+  // else null. This method must not recurse.
+  PendingFunctionAnalysis *verifyDecl(const Decl *D) {
+    // TODO: Is this in the right place?
     const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
     if (FD != nullptr) {
       // Currently, built-in functions are always considered safe.
       if (FD->getBuiltinID() != 0) {
         return nullptr;
       }
-      // If it doesn't have a body, then we have to rely on the declaration.
-
-#warning FIXME
-/*      if (!functionIsVerifiable(mSema, FD)) {
-        // const PerfAnnotation PA = FD->getPerfAnnotation();
-        // if (PA != PerfAnnotation::NoLock) {
-        //   Result.setDiagnostic({ DiagnosticID::DeclExternWithoutConstraint, FD->getLocation(), nullptr });
-        // }
-        return;
-      }*/
     }
-    CallableInfo CInfo{ *D };
+    CallableInfo CInfo(*D);
 
-    // Build a PendingFunctionAnalysis on the stack. If it turns out to be complete,
-    // we'll have avoided a heap allocation; if it's incomplete, it's a fairly
-    // trivial move to a heap-allocated object.
-    PendingFunctionAnalysis FAnalysis{ CInfo, AllInferrableEffectsToVerify };
+    // Build a PendingFunctionAnalysis on the stack. If it turns out to be
+    // complete, we'll have avoided a heap allocation; if it's incomplete, it's
+    // a fairly trivial move to a heap-allocated object.
+    PendingFunctionAnalysis FAnalysis(CInfo, AllInferrableEffectsToVerify);
 
-    llvm::outs() << "\nVerifying " << CInfo.name(mSema) << " ";
+    llvm::outs() << "\nVerifying " << CInfo.name(Sem) << " ";
     FAnalysis.dump(llvm::outs());
 
-    FunctionBodyASTVisitor Visitor{ *this, FAnalysis, CInfo };
+    FunctionBodyASTVisitor Visitor(*this, FAnalysis, CInfo);
 
     Visitor.run();
     if (FAnalysis.isComplete()) {
@@ -2919,83 +2898,88 @@ class Analyzer {
       return nullptr;
     }
     // Copy the pending analysis to the heap and save it in the map.
-    auto* pendingPtr = new PendingFunctionAnalysis(std::move(FAnalysis));
-    DeclAnalysis[D] = pendingPtr;
-    llvm::outs() << "inserted pending " << pendingPtr << "\n";
-    DeclAnalysis.dump(mSema, llvm::outs());
-    return pendingPtr;
-  }
-
-  // Consume PendingFunctionAnalysis, transformed to CompleteFunctionAnalysis and inserted
-  // in the container.
-  void completeAnalysis(const CallableInfo& CInfo, PendingFunctionAnalysis& pending)
-  {
-    if (auto* diags = pending.getDiagnosticsForExplicitFX()) {
-      emitDiagnostics(*diags, CInfo, mSema);
-    }
-    auto* completePtr = new CompleteFunctionAnalysis(pending,
-      CInfo.Effects, AllInferrableEffectsToVerify);
-    DeclAnalysis[CInfo.CDecl] = completePtr;
-    llvm::outs() << "inserted complete " << completePtr << "\n";
-    DeclAnalysis.dump(mSema, llvm::outs());
-  }
-
-  // Called after all direct calls requiring inference have been found -- or not.
-  // Generally replicates FunctionBodyASTVisitor::followCall() but without the
-  // possibility of inference.
-  void finishPendingAnalysis(const Decl* D, PendingFunctionAnalysis* pending)
-  {
-      CallableInfo Caller{ *D };
-      for (const auto& call : pending->unverifiedCalls()) {
-        CallableInfo Callee{ *call.Callee };
-        followCall(Caller, *pending, Callee, call.CallLoc, /*assertNoFurtherInference=*/true);
-      }
-      completeAnalysis(Caller, *pending);
-      delete pending;
-      llvm::outs() << "destroyed pending " << pending << "\n";
+    auto *PendingPtr = new PendingFunctionAnalysis(std::move(FAnalysis));
+    DeclAnalysis[D] = PendingPtr;
+    llvm::outs() << "inserted pending " << PendingPtr << "\n";
+    DeclAnalysis.dump(Sem, llvm::outs());
+    return PendingPtr;
+  }
+
+  // Consume PendingFunctionAnalysis, transformed to CompleteFunctionAnalysis
+  // and inserted in the container.
+  void completeAnalysis(const CallableInfo &CInfo,
+                        PendingFunctionAnalysis &Pending) {
+    if (auto *Diags = Pending.getDiagnosticsForExplicitFX()) {
+      emitDiagnostics(*Diags, CInfo, Sem);
+    }
+    auto *CompletePtr = new CompleteFunctionAnalysis(
+        Pending, CInfo.Effects, AllInferrableEffectsToVerify);
+    DeclAnalysis[CInfo.CDecl] = CompletePtr;
+    llvm::outs() << "inserted complete " << CompletePtr << "\n";
+    DeclAnalysis.dump(Sem, llvm::outs());
+  }
+
+  // Called after all direct calls requiring inference have been found -- or
+  // not. Generally replicates FunctionBodyASTVisitor::followCall() but without
+  // the possibility of inference.
+  void finishPendingAnalysis(const Decl *D, PendingFunctionAnalysis *Pending) {
+    CallableInfo Caller(*D);
+    for (const auto &Call : Pending->unverifiedCalls()) {
+      CallableInfo Callee(*Call.Callee);
+      followCall(Caller, *Pending, Callee, Call.CallLoc,
+                 /*AssertNoFurtherInference=*/true);
+    }
+    completeAnalysis(Caller, *Pending);
+    delete Pending;
+    llvm::outs() << "destroyed pending " << Pending << "\n";
   }
 
   // Here we have a call to a Decl, either explicitly via a CallExpr or some
   // other AST construct. CallableInfo pertains to the callee.
-  void followCall(const CallableInfo& Caller, PendingFunctionAnalysis &PFA,
-    const CallableInfo& Callee, SourceLocation CallLoc,
-    bool assertNoFurtherInference)
-  {
+  void followCall(const CallableInfo &Caller, PendingFunctionAnalysis &PFA,
+                  const CallableInfo &Callee, SourceLocation CallLoc,
+                  bool AssertNoFurtherInference) {
     const bool DirectCall = Callee.isDirectCall();
     FunctionEffectSet CalleeEffects = Callee.Effects;
-    bool isInferencePossible = DirectCall;
+    bool IsInferencePossible = DirectCall;
 
     if (DirectCall) {
-      if (auto* CFA = DeclAnalysis.completedAnalysisForDecl(Callee.CDecl)) {
+      if (auto *CFA = DeclAnalysis.completedAnalysisForDecl(Callee.CDecl)) {
         CalleeEffects = CFA->VerifiedEffects;
-        isInferencePossible = false; // we've already traversed it
+        IsInferencePossible = false; // we've already traversed it
       }
     }
-    if (assertNoFurtherInference) {
-      assert(!isInferencePossible);
+    if (AssertNoFurtherInference) {
+      assert(!IsInferencePossible);
     }
     if (!Callee.isVerifiable()) {
-      isInferencePossible = false;
+      IsInferencePossible = false;
     }
-    llvm::outs() << "followCall from " << Caller.name(mSema) << " to " << Callee.name(mSema) 
-      << "; verifiable: " << Callee.isVerifiable() << "; callee ";
+    llvm::outs() << "followCall from " << Caller.name(Sem) << " to "
+                 << Callee.name(Sem)
+                 << "; verifiable: " << Callee.isVerifiable() << "; callee ";
     CalleeEffects.dump(llvm::outs());
     llvm::outs() << "\n";
     puts("");
 
-    auto check1Effect = [&](const FunctionEffect* effect, bool inferring) {
-      const auto flags = effect->getFlags();
-      if (flags & FunctionEffect::kVerifyCalls) {
-        const bool diagnose = effect->diagnoseFunctionCall(DirectCall, Caller.CDecl, Caller.Effects,
-          Callee.CDecl, CalleeEffects);
+    auto check1Effect = [&](const FunctionEffect *Effect, bool Inferring) {
+      const auto Flags = Effect->flags();
+      if (Flags & FunctionEffect::kVerifyCalls) {
+        const bool diagnose = Effect->diagnoseFunctionCall(
+            DirectCall, Caller.CDecl, Caller.Effects, Callee.CDecl,
+            CalleeEffects);
         if (diagnose) {
-          // If inference is not allowed, or the target is indirect (virtual method/function ptr?),
-          // generate a diagnostic now.
-          if (!isInferencePossible || !(flags & FunctionEffect::kInferrableOnCallees)) {
+          // If inference is not allowed, or the target is indirect (virtual
+          // method/function ptr?), generate a diagnostic now.
+          if (!IsInferencePossible ||
+              !(Flags & FunctionEffect::kInferrableOnCallees)) {
             if (Callee.FuncType == SpecialFuncType::None) {
-              PFA.checkAddDiagnostic(inferring, { effect, DiagnosticID::CallsUnsafeDecl, CallLoc, Callee.CDecl });
+              PFA.checkAddDiagnostic(Inferring,
+                                     {Effect, DiagnosticID::CallsUnsafeDecl,
+                                      CallLoc, Callee.CDecl});
             } else {
-              PFA.checkAddDiagnostic(inferring, { effect, DiagnosticID::AllocatesMemory, CallLoc });
+              PFA.checkAddDiagnostic(
+                  Inferring, {Effect, DiagnosticID::AllocatesMemory, CallLoc});
             }
           } else {
             // Inference is allowed and necessary; defer it.
@@ -3005,215 +2989,225 @@ class Analyzer {
       }
     };
 
-    for (auto* effect : PFA.DeclaredVerifiableEffects) {
-      check1Effect(effect, false);
+    for (auto *Effect : PFA.DeclaredVerifiableEffects) {
+      check1Effect(Effect, false);
     }
 
-    for (auto* effect : PFA.FXToInfer) {
-      check1Effect(effect, true);
+    for (auto *Effect : PFA.FXToInfer) {
+      check1Effect(Effect, true);
     }
   }
 
   // Should only be called when determined to be complete.
-  void emitDiagnostics(SmallVector<Diagnostic>& Diags, const CallableInfo& CInfo, Sema& S)
-  {
+  void emitDiagnostics(SmallVector<Diagnostic> &Diags,
+                       const CallableInfo &CInfo, Sema &S) {
 #define UNTESTED __builtin_trap();
 #define TESTED
-    const SourceManager& SM = S.getSourceManager();
-    std::sort(Diags.begin(), Diags.end(), [&SM](const Diagnostic& lhs, const Diagnostic& rhs) {
-      return SM.isBeforeInTranslationUnit(lhs.Loc, rhs.Loc);
-    });
+    const SourceManager &SM = S.getSourceManager();
+    std::sort(Diags.begin(), Diags.end(),
+              [&SM](const Diagnostic &LHS, const Diagnostic &RHS) {
+                return SM.isBeforeInTranslationUnit(LHS.Loc, RHS.Loc);
+              });
 
     const auto TopFuncName = CInfo.name(S);
 
     // TODO: Can we get better template instantiation notes?
-    auto checkAddTemplateNote = [&](const Decl* D) {
+    auto checkAddTemplateNote = [&](const Decl *D) {
       if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
         while (FD != nullptr && FD->isTemplateInstantiation()) {
-          S.Diag(FD->getPointOfInstantiation(), diag::note_func_effect_from_template);
+          S.Diag(FD->getPointOfInstantiation(),
+                 diag::note_func_effect_from_template);
           FD = FD->getTemplateInstantiationPattern();
         }
       }
     };
 
     // Top-level diagnostics are warnings.
-    for (const auto& Diag : Diags) {
+    for (const auto &Diag : Diags) {
       StringRef effectName = Diag.Effect->name();
       switch (Diag.ID) {
       case DiagnosticID::None:
-      //case DiagnosticID::DeclExternWithoutConstraint:
-      case DiagnosticID::DeclWithoutConstraintOrInference: // shouldn't happen here
-      //case DiagnosticID::DeclVirtualWithoutConstraint:
-      //case DiagnosticID::DeclFuncPtrWithoutConstraint:
+      case DiagnosticID::DeclWithoutConstraintOrInference: // shouldn't happen
+                                                           // here
         llvm_unreachable("Unexpected diagnostic kind");
         break;
       case DiagnosticID::AllocatesMemory:
-        S.Diag(Diag.Loc, diag::warn_func_effect_allocates) << effectName << TopFuncName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_allocates)
+            << effectName << TopFuncName;
         checkAddTemplateNote(CInfo.CDecl);
-              TESTED
+        TESTED
         break;
       case DiagnosticID::Throws:
       case DiagnosticID::Catches:
-        S.Diag(Diag.Loc, diag::warn_func_effect_throws_or_catches) << effectName << TopFuncName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_throws_or_catches)
+            << effectName << TopFuncName;
         checkAddTemplateNote(CInfo.CDecl);
-              TESTED
+        TESTED
         break;
       case DiagnosticID::HasStaticLocal:
-        S.Diag(Diag.Loc, diag::warn_func_effect_has_static_local) << effectName << TopFuncName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_has_static_local)
+            << effectName << TopFuncName;
         checkAddTemplateNote(CInfo.CDecl);
-              TESTED
+        TESTED
         break;
       case DiagnosticID::AccessesThreadLocal:
-        S.Diag(Diag.Loc, diag::warn_func_effect_uses_thread_local) << effectName << TopFuncName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_uses_thread_local)
+            << effectName << TopFuncName;
         checkAddTemplateNote(CInfo.CDecl);
-              TESTED
+        TESTED
         break;
       case DiagnosticID::CallsObjC:
-        S.Diag(Diag.Loc, diag::warn_func_effect_calls_objc) << effectName << TopFuncName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_calls_objc)
+            << effectName << TopFuncName;
         checkAddTemplateNote(CInfo.CDecl);
-              TESTED
+        TESTED
         break;
       case DiagnosticID::CallsDisallowedExpr:
-        S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_expr) << effectName << TopFuncName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_expr)
+            << effectName << TopFuncName;
         checkAddTemplateNote(CInfo.CDecl);
-              UNTESTED
+        UNTESTED
         break;
 
-      case DiagnosticID::CallsUnsafeDecl:
-        {
-          CallableInfo CalleeInfo{ *Diag.Callee };
-          auto CalleeName = CalleeInfo.name(S);
-
-          S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_func) << effectName << TopFuncName << CalleeName;
-          checkAddTemplateNote(CInfo.CDecl);
-
-          // Emit notes explaining the transitive chain of inferences: Why isn't the callee safe?
-          for (const auto* Callee = Diag.Callee; Callee != nullptr; ) {
-            std::optional<CallableInfo> MaybeNextCallee;
-            auto* completed = DeclAnalysis.completedAnalysisForDecl(CalleeInfo.CDecl);
-            if (completed == nullptr) {
-              // No result - could be
-              // - non-inline
-              // - virtual
-              if (CalleeInfo.CType == CallType::Virtual) {
-                S.Diag(Callee->getLocation(), diag::note_func_effect_call_virtual) << effectName << CalleeName;
-                TESTED
-              } else if (CalleeInfo.CType == CallType::Unknown) {
-                S.Diag(Callee->getLocation(), diag::note_func_effect_call_func_ptr) << effectName << CalleeName;
-                TESTED
-              } else {
-                S.Diag(Callee->getLocation(), diag::note_func_effect_call_extern) << effectName << CalleeName;
-                TESTED
-              }
-              break;
-            }
-            const auto* pDiag2 = completed->firstDiagnosticForEffect(Diag.Effect);
-            if (pDiag2 == nullptr) {
-              break;
-            }
+      case DiagnosticID::CallsUnsafeDecl: {
+        CallableInfo CalleeInfo{*Diag.Callee};
+        auto CalleeName = CalleeInfo.name(S);
 
-            const auto& Diag2 = *pDiag2;
-            switch (Diag2.ID) {
-            case DiagnosticID::None:
-              llvm_unreachable("Unexpected diagnostic kind");
-              break;
-            // case DiagnosticID::DeclExternWithoutConstraint:
-            //   S.Diag(Diag2.Loc, diag::note_func_effect_call_extern) << effectName << CalleeName;
-            //   break;
-            case DiagnosticID::DeclWithoutConstraintOrInference:
-              S.Diag(Diag2.Loc, diag::note_func_effect_call_not_inferrable) << effectName << CalleeName;
-              TESTED
-              break;
-            // case DiagnosticID::DeclVirtualWithoutConstraint:
-            //   S.Diag(Diag2.Loc, diag::note_func_effect_call_virtual) << effectName << CalleeName;
-            //   break;
-            //case DiagnosticID::DeclFuncPtrWithoutConstraint:
-            case DiagnosticID::CallsDisallowedExpr:
-              S.Diag(Diag2.Loc, diag::note_func_effect_call_func_ptr) << effectName << CalleeName;
-              UNTESTED
-              break;
-            case DiagnosticID::AllocatesMemory:
-              S.Diag(Diag2.Loc, diag::note_func_effect_allocates) << effectName << CalleeName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_func)
+            << effectName << TopFuncName << CalleeName;
+        checkAddTemplateNote(CInfo.CDecl);
+
+        // Emit notes explaining the transitive chain of inferences: Why isn't
+        // the callee safe?
+        for (const auto *Callee = Diag.Callee; Callee != nullptr;) {
+          std::optional<CallableInfo> MaybeNextCallee;
+          auto *Completed =
+              DeclAnalysis.completedAnalysisForDecl(CalleeInfo.CDecl);
+          if (Completed == nullptr) {
+            // No result - could be
+            // - non-inline
+            // - virtual
+            if (CalleeInfo.CType == CallType::Virtual) {
+              S.Diag(Callee->getLocation(), diag::note_func_effect_call_virtual)
+                  << effectName << CalleeName;
               TESTED
-              break;
-            case DiagnosticID::Throws:
-            case DiagnosticID::Catches:
-              S.Diag(Diag2.Loc, diag::note_func_effect_throws_or_catches) << effectName << CalleeName;
+            } else if (CalleeInfo.CType == CallType::Unknown) {
+              S.Diag(Callee->getLocation(),
+                     diag::note_func_effect_call_func_ptr)
+                  << effectName << CalleeName;
               TESTED
-              break;
-            case DiagnosticID::HasStaticLocal:
-              S.Diag(Diag2.Loc, diag::note_func_effect_has_static_local) << effectName << CalleeName;
-              UNTESTED
-              break;
-            case DiagnosticID::AccessesThreadLocal:
-              S.Diag(Diag2.Loc, diag::note_func_effect_uses_thread_local) << effectName << CalleeName;
-              UNTESTED
-              break;
-            case DiagnosticID::CallsObjC:
-              S.Diag(Diag2.Loc, diag::note_func_effect_calls_objc) << effectName << CalleeName;
-              UNTESTED
-              break;
-            case DiagnosticID::CallsUnsafeDecl:
-              MaybeNextCallee.emplace(*Diag2.Callee);
-              S.Diag(Diag2.Loc, diag::note_func_effect_calls_disallowed_func) << effectName << CalleeName << MaybeNextCallee->name(S);
+            } else {
+              S.Diag(Callee->getLocation(), diag::note_func_effect_call_extern)
+                  << effectName << CalleeName;
               TESTED
-              break;
-            }
-            checkAddTemplateNote(Callee);
-            Callee = Diag2.Callee;
-            if (MaybeNextCallee) {
-              CalleeInfo = *MaybeNextCallee;
-              CalleeName = CalleeInfo.name(S);
             }
+            break;
+          }
+          const auto *pDiag2 = Completed->firstDiagnosticForEffect(Diag.Effect);
+          if (pDiag2 == nullptr) {
+            break;
+          }
+
+          const auto &Diag2 = *pDiag2;
+          switch (Diag2.ID) {
+          case DiagnosticID::None:
+            llvm_unreachable("Unexpected diagnostic kind");
+            break;
+          case DiagnosticID::DeclWithoutConstraintOrInference:
+            S.Diag(Diag2.Loc, diag::note_func_effect_call_not_inferrable)
+                << effectName << CalleeName;
+            TESTED
+            break;
+          case DiagnosticID::CallsDisallowedExpr:
+            S.Diag(Diag2.Loc, diag::note_func_effect_call_func_ptr)
+                << effectName << CalleeName;
+            UNTESTED
+            break;
+          case DiagnosticID::AllocatesMemory:
+            S.Diag(Diag2.Loc, diag::note_func_effect_allocates)
+                << effectName << CalleeName;
+            TESTED
+            break;
+          case DiagnosticID::Throws:
+          case DiagnosticID::Catches:
+            S.Diag(Diag2.Loc, diag::note_func_effect_throws_or_catches)
+                << effectName << CalleeName;
+            TESTED
+            break;
+          case DiagnosticID::HasStaticLocal:
+            S.Diag(Diag2.Loc, diag::note_func_effect_has_static_local)
+                << effectName << CalleeName;
+            UNTESTED
+            break;
+          case DiagnosticID::AccessesThreadLocal:
+            S.Diag(Diag2.Loc, diag::note_func_effect_uses_thread_local)
+                << effectName << CalleeName;
+            UNTESTED
+            break;
+          case DiagnosticID::CallsObjC:
+            S.Diag(Diag2.Loc, diag::note_func_effect_calls_objc)
+                << effectName << CalleeName;
+            UNTESTED
+            break;
+          case DiagnosticID::CallsUnsafeDecl:
+            MaybeNextCallee.emplace(*Diag2.Callee);
+            S.Diag(Diag2.Loc, diag::note_func_effect_calls_disallowed_func)
+                << effectName << CalleeName << MaybeNextCallee->name(S);
+            TESTED
+            break;
+          }
+          checkAddTemplateNote(Callee);
+          Callee = Diag2.Callee;
+          if (MaybeNextCallee) {
+            CalleeInfo = *MaybeNextCallee;
+            CalleeName = CalleeInfo.name(S);
           }
         }
-        break;
+      } break;
       }
     }
   }
 
   // ----------
-  // This AST visitor is used to traverse the body of a function during effect verification.
-  // This happens in 2 distinct situations:
-  // [1] The function has declared effects which need to be validated.
-  // [2] The function has not explicitly declared an effect in question, and is being
-  //    checked for implicit conformance.
-  // When we are verifying explicit conformance [1] we should generate all diagnostics.
-  // When we are inferring conformance [2] we will need to save enough diagnostics
-  // to provide a note to explain why inference failed; just the first violation per
-  // FunctionEffect.
+  // This AST visitor is used to traverse the body of a function during effect
+  // verification. This happens in 2 situations:
+  //  [1] The function has declared effects which need to be validated.
+  //  [2] The function has not explicitly declared an effect in question, and is
+  //      being checked for implicit conformance.
   //
-  // Populates a provided FunctionAnalysis object.
+  // Diagnostics are always routed to a PendingFunctionAnalysis, which holds
+  // all diagnostic output.
   //
-  // TODO: Currently we create a new RecursiveASTVisitor for every function analysis.
-  // Is it so lightweight that this is OK? It would appear so.
-  struct FunctionBodyASTVisitor : public RecursiveASTVisitor<FunctionBodyASTVisitor> {
+  // TODO: Currently we create a new RecursiveASTVisitor for every function
+  // analysis. Is it so lightweight that this is OK? It would appear so.
+  struct FunctionBodyASTVisitor
+      : public RecursiveASTVisitor<FunctionBodyASTVisitor> {
     constexpr static bool Stop = false;
     constexpr static bool Proceed = true;
-    
+
     Analyzer &Outer;
     PendingFunctionAnalysis &CurrentFunction;
-    CallableInfo& CurrentCaller;
+    CallableInfo &CurrentCaller;
 
-    FunctionBodyASTVisitor(Analyzer &outer, PendingFunctionAnalysis &CurrentFunction,
-      CallableInfo& CurrentCaller)
-      : Outer{ outer }, CurrentFunction{ CurrentFunction }, CurrentCaller{ CurrentCaller }
-    {
-    }
+    FunctionBodyASTVisitor(Analyzer &outer,
+                           PendingFunctionAnalysis &CurrentFunction,
+                           CallableInfo &CurrentCaller)
+        : Outer(outer), CurrentFunction(CurrentFunction),
+          CurrentCaller(CurrentCaller) {}
 
     // -- Entry point --
     void run()
     {
-      // The target function itself may have some implicit code paths beyond the body:
-      // member and base constructors and destructors.
+      // The target function itself may have some implicit code paths beyond the
+      // body: member and base constructors and destructors. Visit these first.
       if (const auto *FD = dyn_cast<const FunctionDecl>(CurrentCaller.CDecl)) {
-        if (auto* Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
-          for (const CXXCtorInitializer* Initer : Ctor->inits()) {
-            if (Expr* Init = Initer->getInit()) {
+        if (auto *Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
+          for (const CXXCtorInitializer *Initer : Ctor->inits()) {
+            if (Expr *Init = Initer->getInit()) {
               VisitStmt(Init);
             }
           }
-        } else if (auto* Dtor = dyn_cast<CXXDestructorDecl>(FD)) {
+        } else if (auto *Dtor = dyn_cast<CXXDestructorDecl>(FD)) {
           followDestructor(dyn_cast<CXXRecordDecl>(Dtor->getParent()), Dtor);
         } else if (!FD->isTrivial() && FD->isDefaulted()) {
           // needed? maybe not
@@ -3222,100 +3216,105 @@ class Analyzer {
       // else could be BlockDecl
 
       // Do an AST traversal of the function/block body
-      TraverseDecl(const_cast<Decl*>(CurrentCaller.CDecl));
+      TraverseDecl(const_cast<Decl *>(CurrentCaller.CDecl));
     }
 
     // -- Methods implementing common logic --
 
-    // Only effects whose flags include the specified flag receive a potential diagnostic.
-    // TODO: Consider bypasses for these loops by precomputing the flags we care about?
-    void addDiagnostic(FunctionEffect::FlagBit Flag, DiagnosticID D, SourceLocation Loc,
-      const Decl* Callee = nullptr)
+    // Handle a language construct forbidden by some effects. Only effects whose
+    // flags include the specified flag receive a diagnostic. \p Flag describes
+    // the construct.
+    void diagnoseLanguageConstruct(FunctionEffect::FlagBit Flag, DiagnosticID D,
+                       SourceLocation Loc, const Decl *Callee = nullptr)
     {
-      // If there are ANY declared verifiable effects holding the flag, store just one diagnostic.
-      for (auto* effect : CurrentFunction.DeclaredVerifiableEffects) {
-        if (effect->getFlags() & Flag) {
-          addDiagnosticInner(/*inferring=*/false, effect, D, Loc, Callee);
+      // If there are ANY declared verifiable effects holding the flag, store
+      // just one diagnostic.
+      for (auto *Effect : CurrentFunction.DeclaredVerifiableEffects) {
+        if (Effect->flags() & Flag) {
+          addDiagnosticInner(/*inferring=*/false, Effect, D, Loc, Callee);
           break;
         }
       }
-      // For each inferred-but-not-verifiable effect holding the flag, store a diagnostic,
-      // if we don't already have a diagnostic for that effect.
-      for (auto* effect : CurrentFunction.FXToInfer) {
-        if (effect->getFlags() & Flag) {
-          addDiagnosticInner(/*inferring=*/true, effect, D, Loc, Callee);
+      // For each inferred-but-not-verifiable effect holding the flag, store a
+      // diagnostic, if we don't already have a diagnostic for that effect.
+      for (auto *Effect : CurrentFunction.FXToInfer) {
+        if (Effect->flags() & Flag) {
+          addDiagnosticInner(/*inferring=*/true, Effect, D, Loc, Callee);
         }
       }
     }
 
-    void addDiagnosticInner(bool inferring, const FunctionEffect* effect, DiagnosticID D,
-      SourceLocation Loc, const Decl* Callee = nullptr)
-    {
-      Diagnostic NewDiag{ effect, D, Loc, Callee };
-      CurrentFunction.checkAddDiagnostic(inferring, NewDiag);
+    void addDiagnosticInner(bool Inferring, const FunctionEffect *Effect,
+                            DiagnosticID D, SourceLocation Loc,
+                            const Decl *Callee = nullptr) {
+      CurrentFunction.checkAddDiagnostic(Inferring, 
+        Diagnostic(Effect, D, Loc, Callee));
     }
 
     // Here we have a call to a Decl, either explicitly via a CallExpr or some
     // other AST construct. CallableInfo pertains to the callee.
-    void followCall(const CallableInfo& CI, SourceLocation CallLoc)
-    {
-      Outer.followCall(CurrentCaller, CurrentFunction, CI, CallLoc, /*assertNoFurtherInference=*/false);
+    void followCall(const CallableInfo &CI, SourceLocation CallLoc) {
+      Outer.followCall(CurrentCaller, CurrentFunction, CI, CallLoc,
+                       /*AssertNoFurtherInference=*/false);
     }
 
-    void checkIndirectCall(CallExpr* Call, Expr* CalleeExpr)
-    {
+    void checkIndirectCall(CallExpr *Call, Expr *CalleeExpr) {
       const auto CalleeType = CalleeExpr->getType();
-      auto *FPT = CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
-
-      auto check1Effect = [&](const FunctionEffect* effect, bool inferring) {
-        if (effect->getFlags() & FunctionEffect::kVerifyCalls) {
-          if (FPT == nullptr || effect->diagnoseFunctionCall(/*direct=*/false, 
-            CurrentCaller.CDecl, CurrentCaller.Effects, FPT, FPT->getFunctionEffects())) {
-            addDiagnosticInner(inferring, effect, DiagnosticID::CallsDisallowedExpr, Call->getBeginLoc());
+      auto *FPT =
+          CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
+
+      auto check1Effect = [&](const FunctionEffect *effect, bool inferring) {
+        if (effect->flags() & FunctionEffect::kVerifyCalls) {
+          if (FPT == nullptr ||
+              effect->diagnoseFunctionCall(
+                  /*direct=*/false, CurrentCaller.CDecl, CurrentCaller.Effects,
+                  FPT, FPT->getFunctionEffects())) {
+            addDiagnosticInner(inferring, effect,
+                               DiagnosticID::CallsDisallowedExpr,
+                               Call->getBeginLoc());
           }
         }
       };
 
-      for (auto* effect : CurrentFunction.DeclaredVerifiableEffects) {
+      for (auto *effect : CurrentFunction.DeclaredVerifiableEffects) {
         check1Effect(effect, false);
       }
 
-      for (auto* effect : CurrentFunction.FXToInfer) {
+      for (auto *effect : CurrentFunction.FXToInfer) {
         check1Effect(effect, true);
       }
     }
 
-    // This destructor's body should be followed by the caller, but here we follow
-    // the field and base destructors.
-    void followDestructor(const CXXRecordDecl* Rec, const CXXDestructorDecl* Dtor)
-    {
-      for (const FieldDecl* Field : Rec->fields()) {
+    // This destructor's body should be followed by the caller, but here we
+    // follow the field and base destructors.
+    void followDestructor(const CXXRecordDecl *Rec,
+                          const CXXDestructorDecl *Dtor) {
+      for (const FieldDecl *Field : Rec->fields()) {
         followTypeDtor(Field->getType());
       }
 
-      if (const auto* Class = dyn_cast<CXXRecordDecl>(Rec)) {
-        for (const CXXBaseSpecifier& Base : Class->bases()) {
+      if (const auto *Class = dyn_cast<CXXRecordDecl>(Rec)) {
+        for (const CXXBaseSpecifier &Base : Class->bases()) {
           followTypeDtor(Base.getType());
         }
-        for (const CXXBaseSpecifier& Base : Class->vbases()) {
+        for (const CXXBaseSpecifier &Base : Class->vbases()) {
           followTypeDtor(Base.getType());
         }
       }
     }
 
-    void followTypeDtor(QualType QT)
-    {
-      const Type* Ty = QT.getTypePtr();
+    void followTypeDtor(QualType QT) {
+      const Type *Ty = QT.getTypePtr();
       while (Ty->isArrayType()) {
-        const ArrayType* Arr = Ty->getAsArrayTypeUnsafe();
+        const ArrayType *Arr = Ty->getAsArrayTypeUnsafe();
         QT = Arr->getElementType();
         Ty = QT.getTypePtr();
       }
 
       if (Ty->isRecordType()) {
-        if (const CXXRecordDecl* Class = Ty->getAsCXXRecordDecl()) {
-          if (auto* Dtor = Class->getDestructor()) {
-            CallableInfo CI{ *Dtor };
+        if (const CXXRecordDecl *Class = Ty->getAsCXXRecordDecl()) {
+          if (auto *Dtor = Class->getDestructor()) {
+            CallableInfo CI{*Dtor};
             followCall(CI, Dtor->getLocation());
           }
         }
@@ -3334,37 +3333,34 @@ class Analyzer {
 
     bool shouldWalkTypesOfTypeLocs() const { return false; }
 
-    bool VisitCXXThrowExpr(CXXThrowExpr* Throw)
-    {
-      addDiagnostic(FunctionEffect::kExcludeThrow, DiagnosticID::Throws, Throw->getThrowLoc());
+    bool VisitCXXThrowExpr(CXXThrowExpr *Throw) {
+      diagnoseLanguageConstruct(FunctionEffect::kExcludeThrow, DiagnosticID::Throws,
+                                Throw->getThrowLoc());
       return Proceed;
     }
 
-    bool VisitCXXCatchStmt(CXXCatchStmt* Catch)
-    {
-      addDiagnostic(FunctionEffect::kExcludeCatch, DiagnosticID::Catches, Catch->getCatchLoc());
+    bool VisitCXXCatchStmt(CXXCatchStmt *Catch) {
+      diagnoseLanguageConstruct(FunctionEffect::kExcludeCatch, DiagnosticID::Catches,
+                                Catch->getCatchLoc());
       return Proceed;
     }
 
-    bool VisitObjCMessageExpr(ObjCMessageExpr* Msg)
-    {
-      addDiagnostic(FunctionEffect::kExcludeObjCMessageSend, DiagnosticID::CallsObjC, Msg->getBeginLoc());
+    bool VisitObjCMessageExpr(ObjCMessageExpr *Msg) {
+      diagnoseLanguageConstruct(FunctionEffect::kExcludeObjCMessageSend,
+                                DiagnosticID::CallsObjC, Msg->getBeginLoc());
       return Proceed;
     }
 
-    bool VisitCallExpr(CallExpr* Call)
-    {
+    bool VisitCallExpr(CallExpr *Call) {
       if constexpr (kDebugLogLevel > 2) {
-        llvm::errs() << "VisitCallExpr : " << Call->getBeginLoc().printToString(Outer.mSema.SourceMgr) << "\n";
+        llvm::errs() << "VisitCallExpr : "
+                     << Call->getBeginLoc().printToString(Outer.Sem.SourceMgr)
+                     << "\n";
       }
 
-      /*if ((AllFlagsOfFXToVerify & FunctionEffect::kVerifyCalls) == 0u) {
-        return Proceed;
-      }*/
-
-      Expr* CalleeExpr = Call->getCallee();
-      if (const Decl* Callee = CalleeExpr->getReferencedDeclOfCallee()) {
-        CallableInfo CI{ *Callee };
+      Expr *CalleeExpr = Call->getCallee();
+      if (const Decl *Callee = CalleeExpr->getReferencedDeclOfCallee()) {
+        CallableInfo CI(*Callee);
         followCall(CI, Call->getBeginLoc());
         return Proceed;
       }
@@ -3380,30 +3376,36 @@ class Analyzer {
       // into it and look for a DeclRefExpr. But for now it should suffice
       // to look at the type of the Expr. Well, unless we're in a template :-/
 
-      //llvm::errs() << "CalleeExpr ";
-      //CalleeExpr->dumpColor();
-      //llvm::errs() << Call->getBeginLoc().printToString(Outer.S.getSourceManager()) << ": warning: null callee\n";
+      // llvm::errs() << "CalleeExpr ";
+      // CalleeExpr->dumpColor();
+      // llvm::errs() <<
+      // Call->getBeginLoc().printToString(Outer.S.getSourceManager()) << ":
+      // warning: null callee\n";
 
       return Proceed;
     }
 
-    bool VisitVarDecl(VarDecl* Var)
-    {
+    bool VisitVarDecl(VarDecl *Var) {
       if constexpr (kDebugLogLevel > 2) {
-        llvm::errs() << "VisitVarDecl : " << Var->getBeginLoc().printToString(Outer.mSema.SourceMgr) << "\n";
+        llvm::errs() << "VisitVarDecl : "
+                     << Var->getBeginLoc().printToString(Outer.Sem.SourceMgr)
+                     << "\n";
       }
 
       if (Var->isStaticLocal()) {
-        addDiagnostic(FunctionEffect::kExcludeStaticLocalVars, DiagnosticID::HasStaticLocal, Var->getLocation());
+        diagnoseLanguageConstruct(FunctionEffect::kExcludeStaticLocalVars,
+                                  DiagnosticID::HasStaticLocal, Var->getLocation());
       }
 
-      const QualType::DestructionKind DK = Var->needsDestruction(Outer.mSema.getASTContext());
+      const QualType::DestructionKind DK =
+          Var->needsDestruction(Outer.Sem.getASTContext());
       if (DK == QualType::DK_cxx_destructor) {
         QualType QT = Var->getType();
-        if (const auto* ClsType = QT.getTypePtr()->getAs<RecordType>()) {
-          if (const auto* CxxRec = dyn_cast<CXXRecordDecl>(ClsType->getDecl())) {
-            if (const auto* Dtor = CxxRec->getDestructor()) {
-              CallableInfo CI{ *Dtor };
+        if (const auto *ClsType = QT.getTypePtr()->getAs<RecordType>()) {
+          if (const auto *CxxRec =
+                  dyn_cast<CXXRecordDecl>(ClsType->getDecl())) {
+            if (const auto *Dtor = CxxRec->getDestructor()) {
+              CallableInfo CI(*Dtor);
               followCall(CI, Var->getLocation());
             }
           }
@@ -3412,12 +3414,11 @@ class Analyzer {
       return Proceed;
     }
 
-    bool VisitCXXNewExpr(CXXNewExpr* New)
-    {
+    bool VisitCXXNewExpr(CXXNewExpr *New) {
       // BUG? It seems incorrect that RecursiveASTVisitor does not
       // visit the call to operator new.
-      if (auto* FD = New->getOperatorNew()) {
-        CallableInfo CI{ *FD, SpecialFuncType::OperatorNew };
+      if (auto *FD = New->getOperatorNew()) {
+        CallableInfo CI(*FD, SpecialFuncType::OperatorNew);
         followCall(CI, New->getBeginLoc());
       }
 
@@ -3429,12 +3430,11 @@ class Analyzer {
       return Proceed;
     }
 
-    bool VisitCXXDeleteExpr(CXXDeleteExpr* Delete)
-    {
+    bool VisitCXXDeleteExpr(CXXDeleteExpr *Delete) {
       // BUG? It seems incorrect that RecursiveASTVisitor does not
       // visit the call to operator delete.
-      if (auto* FD = Delete->getOperatorDelete()) {
-        CallableInfo CI{ *FD, SpecialFuncType::OperatorDelete };
+      if (auto *FD = Delete->getOperatorDelete()) {
+        CallableInfo CI(*FD, SpecialFuncType::OperatorDelete);
         followCall(CI, Delete->getBeginLoc());
       }
 
@@ -3443,71 +3443,69 @@ class Analyzer {
       return Proceed;
     }
 
-    bool VisitCXXConstructExpr(CXXConstructExpr* Construct)
-    {
+    bool VisitCXXConstructExpr(CXXConstructExpr *Construct) {
       if constexpr (kDebugLogLevel > 2) {
-        llvm::errs() << "VisitCXXConstructExpr : " << 
-          Construct->getBeginLoc().printToString(Outer.mSema.SourceMgr) << "\n";
+        llvm::errs() << "VisitCXXConstructExpr : "
+                     << Construct->getBeginLoc().printToString(
+                            Outer.Sem.SourceMgr)
+                     << "\n";
       }
 
       // BUG? It seems incorrect that RecursiveASTVisitor does not
       // visit the call to the constructor.
-      const CXXConstructorDecl* Ctor = Construct->getConstructor();
-      CallableInfo CI{ *Ctor };
+      const CXXConstructorDecl *Ctor = Construct->getConstructor();
+      CallableInfo CI(*Ctor);
       followCall(CI, Construct->getLocation());
 
       return Proceed;
     }
 
-    bool VisitCXXDefaultInitExpr(CXXDefaultInitExpr* DEI)
-    {
-      if (auto* Expr = DEI->getExpr()) {
+    bool VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DEI) {
+      if (auto *Expr = DEI->getExpr()) {
         TraverseStmt(Expr);
       }
       return Proceed;
     }
 
-    bool TraverseLambdaExpr(LambdaExpr* Lambda)
-    {
+    bool TraverseLambdaExpr(LambdaExpr *Lambda) {
       // We override this so as the be able to skip traversal of the lambda's
       // body. We have to explicitly traverse the captures.
       for (unsigned I = 0, N = Lambda->capture_size(); I < N; ++I) {
         if (TraverseLambdaCapture(Lambda, Lambda->capture_begin() + I,
-          Lambda->capture_init_begin()[I]) == Stop) return Stop;
+                                  Lambda->capture_init_begin()[I]) == Stop)
+          return Stop;
       }
 
       return Proceed;
     }
 
-    bool TraverseBlockExpr(BlockExpr* /*unused*/)
-    {
+    bool TraverseBlockExpr(BlockExpr * /*unused*/) {
       // TODO: are the capture expressions (ctor call?) safe?
       return Proceed;
     }
 
-    bool VisitDeclRefExpr(const DeclRefExpr *E)
-    {
-      const ValueDecl* Val = E->getDecl();
+    bool VisitDeclRefExpr(const DeclRefExpr *E) {
+      const ValueDecl *Val = E->getDecl();
       if (isa<VarDecl>(Val)) {
-        const VarDecl* Var = cast<VarDecl>(Val);
+        const VarDecl *Var = cast<VarDecl>(Val);
         const auto TLSK = Var->getTLSKind();
         if (TLSK != VarDecl::TLS_None) {
           // At least on macOS, thread-local variables are initialized on
           // first access.
-          addDiagnostic(FunctionEffect::kExcludeThreadLocalVars,
-            DiagnosticID::AccessesThreadLocal, E->getLocation());
+          diagnoseLanguageConstruct(FunctionEffect::kExcludeThreadLocalVars,
+                                    DiagnosticID::AccessesThreadLocal, E->getLocation());
         }
       }
       return Proceed;
     }
 
-
     // Unevaluated contexts: need to skip
     // see https://reviews.llvm.org/rG777eb4bcfc3265359edb7c979d3e5ac699ad4641
 
     // bool TraverseTypeLoc(TypeLoc /*unused*/)
     // {
-    //   // This is a big blunt hammer so that we don't reach __invoke()'s call to declval().
+    //   // This is a big blunt hammer so that we don't reach __invoke()'s call
+    //   to declval().
     //   // Is it correct?
     //   return Proceed;
     // }
@@ -3515,7 +3513,9 @@ class Analyzer {
     bool TraverseGenericSelectionExpr(GenericSelectionExpr *Node) {
       return TraverseStmt(Node->getResultExpr());
     }
-    bool TraverseUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *Node) { return Proceed; }
+    bool TraverseUnaryExprOrTypeTraitExpr(UnaryExprOrTypeTraitExpr *Node) {
+      return Proceed;
+    }
 
     bool TraverseTypeOfExprTypeLoc(TypeOfExprTypeLoc Node) { return Proceed; }
 
@@ -3536,338 +3536,84 @@ class Analyzer {
   // -----
   // Called for every callable in the translation unit.
   struct CallableFinderCallback : MatchFinder::MatchCallback {
-    Sema& mSema;
+    Sema &Sem;
 
-    CallableFinderCallback(Sema& S) : mSema{ S } {}
+    CallableFinderCallback(Sema &S) : Sem(S) {}
 
     void run(const MatchFinder::MatchResult &Result) override {
-      if (auto* Callable = Result.Nodes.getNodeAs<Decl>(Tag_Callable)) {
+      if (auto *Callable = Result.Nodes.getNodeAs<Decl>(Tag_Callable)) {
         if (const auto FX = functionEffectsForDecl(Callable)) {
           // Reuse this filtering method in Sema
-          mSema.CheckAddCallableWithEffects(Callable, FX);
+          Sem.CheckAddCallableWithEffects(Callable, FX);
         }
       }
     }
 
     static FunctionEffectSet functionEffectsForDecl(const Decl *D) {
-      if (auto* FD = D->getAsFunction()) {
+      if (auto *FD = D->getAsFunction()) {
         return FD->getFunctionEffects();
       }
-      if (auto* BD = dyn_cast<BlockDecl>(D)) {
-        return BD->getFunctionEffects(); 
+      if (auto *BD = dyn_cast<BlockDecl>(D)) {
+        return BD->getFunctionEffects();
       }
       return {};
     }
 
-    static void get(Sema &S,const TranslationUnitDecl& TU)
-    {
+    static void get(Sema &S, const TranslationUnitDecl &TU) {
       MatchFinder CallableFinder;
-      CallableFinderCallback Callback{ S };
+      CallableFinderCallback Callback(S);
 
       using namespace clang::ast_matchers;
 
       CallableFinder.addMatcher(
-          decl(forEachDescendant(decl(anyOf(
-              functionDecl(hasBody(anything())).bind(Tag_Callable),
-              //objcMethodDecl(isDefinition()).bind(Tag_Callable), // no, always unsafe
-              blockDecl().bind(Tag_Callable))))),
+          decl(forEachDescendant(
+              decl(anyOf(functionDecl(hasBody(anything())).bind(Tag_Callable),
+                         // objcMethodDecl(isDefinition()).bind(Tag_Callable),
+                         // // no, always unsafe
+                         blockDecl().bind(Tag_Callable))))),
           &Callback);
-      // Matching LambdaExpr this way [a] doesn't seem to work (need to check for Stmt?)
-      // and [b] doesn't seem necessary, since the anonymous function is reached via the above.
-      // CallableFinder.addMatcher(stmt(forEachDescendant(stmt(lambdaExpr().bind(Tag_Callable)))), &Callback);
+      // Matching LambdaExpr this way [a] doesn't seem to work (need to check
+      // for Stmt?) and [b] doesn't seem necessary, since the anonymous function
+      // is reached via the above.
+      // CallableFinder.addMatcher(stmt(forEachDescendant(stmt(lambdaExpr().bind(Tag_Callable)))),
+      // &Callback);
 
       CallableFinder.match(TU, TU.getASTContext());
     }
   };
 
-  void verifyRootDecls(const TranslationUnitDecl& TU) const
-  {
+  void verifyRootDecls(const TranslationUnitDecl &TU) const {
     // If this weren't debug code, it would be good to find a way to move/swap
     // instead of copying.
-    SmallVector<const Decl *> decls = mSema.DeclsWithUnverifiedEffects;
-    mSema.DeclsWithUnverifiedEffects.clear();
+    SmallVector<const Decl *> decls = Sem.DeclsWithUnverifiedEffects;
+    Sem.DeclsWithUnverifiedEffects.clear();
 
-    CallableFinderCallback::get(mSema, TU);
+    CallableFinderCallback::get(Sem, TU);
 
-    /*if (decls.size() != mSema.DeclsWithUnverifiedEffects.size())*/ {
-      llvm::errs() << "\nFXAnalysis: mSema gathered " << decls.size()
-        << " Decls; second AST pass found " << mSema.DeclsWithUnverifiedEffects.size() << "\n";
+    /*if (decls.size() != Sem.DeclsWithUnverifiedEffects.size())*/ {
+      llvm::errs() << "\nFXAnalysis: Sem gathered " << decls.size()
+                   << " Decls; second AST pass found "
+                   << Sem.DeclsWithUnverifiedEffects.size() << "\n";
     }
   }
 #endif
-
 };
 
-Analyzer::AnalysisMap::~AnalysisMap()
-{
-  for (const auto& item : *this) {
-    auto ptr = item.second;
-    if (isa<PendingFunctionAnalysis*>(ptr)) {
-      delete ptr.get<PendingFunctionAnalysis*>();
+Analyzer::AnalysisMap::~AnalysisMap() {
+  for (const auto &Item : *this) {
+    auto AP = Item.second;
+    if (isa<PendingFunctionAnalysis *>(AP)) {
+      delete AP.get<PendingFunctionAnalysis *>();
     } else {
-      delete ptr.get<CompleteFunctionAnalysis*>();
+      delete AP.get<CompleteFunctionAnalysis *>();
     }
   }
 }
 
 } // namespace FXAnalysis
 
-#if TEMP_DISABLED
-#if 0
-      // OLD OLD OLD from followCall
-      if (CI.PerfAnnot != PerfAnnotation::None) {
-        // Even if the callable turns out to be unsafe, if it is declared safe,
-        // don't create a chain reaction by propagating the error to its callers.
-        if constexpr (kDebugLogLevel > 1) {
-          llvm::errs() << Outer.mDebugIndent << "followCall: safe: " << int(CI.CType) << " " << CI.name() << "\n";
-        }
-
-        if (CI.isVerifiable()) {
-          // The top-level search for callables isn't finding all template instantiations?
-          // Since we have a function body here, possibly verify now.
-          Outer.determineCallableSafety(CI, /*EmitDiags=*/true);
-        } else {
-          Outer.markWithoutFollowing(CI, DiagnosticID::None);
-        }
-
-        return;
-      }
-
-      if constexpr (kDebugLogLevel > 1) {
-        llvm::errs() << Outer.mDebugIndent << "followCall type " << int(CI.CType) << " " << CI.name() << "\n";
-      }
-
-      if (!CI.isDirectCall()) {
-        // Function pointer or virtual method
-        Outer.markWithoutFollowing(CI, CI.CType == CallType::Virtual ?
-          DiagnosticID::DeclVirtualWithoutConstraint : DiagnosticID::DeclFuncPtrWithoutConstraint);
-        return addDiagnostic(DiagnosticID::CallsUnsafeDecl, CallLoc, CI.CDecl);
-      }
-
-      // Here we have a direct call. Are we allowed to infer? If not, emit a diagnostic.
-      if (!CI.isInferrable()) {
-        Outer.markWithoutFollowing(CI, DiagnosticID::DeclWithoutConstraintOrInference);
-        return addDiagnostic(DiagnosticID::CallsUnsafeDecl, CallLoc, CI.CDecl);
-      }
-
-      const DeclInfo& DI = Outer.determineCallableSafety(CI);
-      if (DI.hasDiagnostic()) {
-        if (CI.FuncType == SpecialFuncType::None) {
-          return addDiagnostic(DiagnosticID::CallsUnsafeDecl, CallLoc, CI.CDecl);
-        }
-        return addDiagnostic(DiagnosticID::AllocatesMemory, CallLoc);
-      }
-#endif
-
-
-struct PerfConstraintAnalyzer {
-  // Move all no_locks functions (both explicit and implicitly via call chain)
-  // into a separate code segment?
-  //constexpr static bool kCreateNoLocksSection = true;
-
-  // If non-null, the unsafe callable.
-  using FollowResult = const FunctionDecl*;
-
-  using MatchFinder = ast_matchers::MatchFinder;
-
-
-  // Information recorded about every visited function/block.
-  struct DeclInfo {
-    explicit DeclInfo(PerfAnnotation PA) {} //: DeclPerfAnnot{ PA } {}
-
-    bool hasDiagnostic() const { return Diag.ID != DiagnosticID::None; }
-    const Diagnostic& diagnostic() const { assert(hasDiagnostic()); return Diag; }
-    void setDiagnostic(const Diagnostic& e)
-    {
-        Diag = e;
-    }
-
-    // Scanning: prevent recursion
-    bool isScanning() const { return Scanning; }
-    void setScanning(bool b) { Scanning = b; }
-
-    Diagnostic Diag;
-
-    // This reflects the declared annotation, not the inferred one.
-    //PerfAnnotation DeclPerfAnnot{};
-
-    // Used to prevent infinite recursion.
-    bool Scanning = false;
-  };
-
-  // This contains an entry for every visited callable. Caution: determineCallableSafety
-  // assumes that an iterator remains valid across calls which may mutate the container.
-  using InferenceMap = std::map<const Decl*, DeclInfo>;
-
-  // --
-
-
-  // -----
-
-  Sema& S;
-  InferenceMap mInferenceMap;
-  std::string mDebugIndent;
-
-  // -----
-
-  PerfConstraintAnalyzer(Sema& S)
-    : S{ S }
-  {
-  }
-
-  // Variant of determineCallableSafety where we already know we can't follow
-  // because it is virtual or a function pointer etc. Or, we don't need to follow
-  // it because we know it's OK but we want to have it in the inference table.
-  void markWithoutFollowing(const CallableInfo& CInfo, DiagnosticID Diag)
-  {
-    auto iter = mInferenceMap.lower_bound(CInfo.CDecl);
-    if (iter != mInferenceMap.end() && iter->first == CInfo.CDecl) {
-      return;
-    }
-    iter = mInferenceMap.insert(iter, { CInfo.CDecl, DeclInfo{ CInfo.PerfAnnot } });
-    if (Diag != DiagnosticID::None) {
-      DeclInfo& Result = iter->second;
-      Result.setDiagnostic({ Diag, CInfo.CDecl->getLocation(), nullptr });
-    }
-  }
-
-  void maybeDiagnose(DeclInfo& Result, const Diagnostic& Diag)
-  {
-    Result.setDiagnostic(Diag);
-  }
-
-  // Returns a populated map entry for the given CallableInfo's Decl.
-  // Caller should take special care to avoid recursion when Scanning is true.
-  // EmitDiags should only be true when called from the top-level traversal
-  // of all attributed functions in the TranslationUnit.
-  const DeclInfo& determineCallableSafety(const CallableInfo& CInfo, bool EmitDiags = false)
-  {
-    // If we have already visited this callable, return the previous result.
-    auto iter = mInferenceMap.lower_bound(CInfo.CDecl);
-    if (iter != mInferenceMap.end() && iter->first == CInfo.CDecl) {
-      return iter->second;
-    }
-
-    if constexpr (kDebugLogLevel) {
-      llvm::errs() << mDebugIndent << "determineCallableSafety -> " << CInfo.name() << "\n";
-    }
-
-    iter = mInferenceMap.insert(iter, { CInfo.CDecl, DeclInfo{ CInfo.PerfAnnot } });
-    DeclInfo& Result = iter->second;
-
-    std::optional<PerfConstraintASTVisitor> MaybeVisitor; // built on demand
-    auto getVisitor = [&]() -> PerfConstraintASTVisitor& {
-      if (!MaybeVisitor) {
-        MaybeVisitor.emplace(*this, /*StopOnFirstDiag=*/!EmitDiags);
-      }
-      return *MaybeVisitor;
-    };
-
-    const FunctionDecl *FD = dyn_cast<FunctionDecl>(CInfo.CDecl);
-    if (FD != nullptr) {
-      // Currently, built-in functions are always considered safe.
-      if (FD->getBuiltinID() != 0) {
-        return Result;
-      }
-      // If it doesn't have a body, then we have to rely on the declaration.
-      if (!functionIsVerifiable(S, FD)) {
-        const PerfAnnotation PA = FD->getPerfAnnotation();
-        if (PA != PerfAnnotation::NoLock) {
-          Result.setDiagnostic({ DiagnosticID::DeclExternWithoutConstraint, FD->getLocation(), nullptr });
-        }
-        return Result;
-      }
-
-      if (auto* Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
-        for (const CXXCtorInitializer* Initer : Ctor->inits()) {
-          if (Expr* Init = Initer->getInit()) {
-            Result.setScanning(true);
-            getVisitor().VisitStmt(Init);
-          }
-        }
-      } else if (auto* Dtor = dyn_cast<CXXDestructorDecl>(FD)) {
-        if (auto* UnsafeCallee = followDestructor(dyn_cast<CXXRecordDecl>(Dtor->getParent()), Dtor)) {
-          //const auto PA = UnsafeCallee->getType()->isNoLock() ? PerfAnnotation::True : PerfAnnotation::False;
-          getVisitor().addDiagnostic(DiagnosticID::CallsUnsafeDecl, FD->getLocation(), UnsafeCallee);
-        }
-      } else if (!FD->isTrivial() && FD->isDefaulted()) {
-        // needed? maybe not
-      }
-    }
-
-    if constexpr (kDebugLogLevel) {
-      mDebugIndent += "    ";
-    }
-
-    Result.setScanning(true);
-
-    auto& Visitor = getVisitor();
-    Visitor.TraverseDecl(const_cast<Decl*>(CInfo.CDecl));
-
-    const auto& Diagnostics = Visitor.Diagnostics;
-
-    Result.setScanning(false);
-
-    if constexpr (kDebugLogLevel) {
-      mDebugIndent = mDebugIndent.substr(0, mDebugIndent.size() - 4);
-      llvm::errs() << mDebugIndent << "determineCallableSafety <- " << CInfo.name() << " : " << Diagnostics.size() << " violations\n";
-      //EmitDiags = true; // TEMPORARY
-    }
-
-    if (!Diagnostics.empty()) {
-      if (EmitDiags) {
-        emitDiagnostics(Diagnostics, CInfo);
-      }
-      Result.setDiagnostic(Diagnostics.front());
-    }
-
-    return Result;
-  }
-
-  void emitDiagnostics(const std::vector<Diagnostic>& Diags,
-    const CallableInfo& CInfo)
-  {
-  }
-
-  // Top-level entry point. Search the entire TU for functions to verify.
-  // Ways to optimize:
-  // - are the diagnostics enabled? if not, bail
-  // - did Sema see any tagged functions with bodies? if not, bail
-  void run(const TranslationUnitDecl& TU)
-  {
-
-    /*if constexpr (kCreateNoLocksSection) {
-      createNoLocksSection();
-    }*/
-  }
-
-  /*void createNoLocksSection()
-  {
-    const char* kSectionName = "__TEXT,__nolock,regular,pure_instructions";
-    if (auto err = S.isValidSectionSpecifier(kSectionName)) {
-      // real diagnostic?
-      llvm::errs() << "error: invalid section name " << kSectionName << " (" << err << ")\n";
-      return;
-    }
-
-    auto& MapEntry = S.getASTContext().SemaAnalysisGeneratedSections[kSectionName];
-    MapEntry.reserve(mInferenceMap.size());
-    for (auto& item : mInferenceMap) {
-      MapEntry.emplace_back(item.first);
-      if constexpr (kDebugLogLevel > 1) {
-        if (auto* F = dyn_cast<FunctionDecl>(item.first)) {
-          CallableInfo CI{ *F, S };
-          llvm::errs() << "nolock: " << CI.name() << "\n";
-        }
-      }
-    }
-  }*/
-};
-#endif // TEMP_DISABLED
-
 // =============================================================================
 
-
 //===----------------------------------------------------------------------===//
 // AnalysisBasedWarnings - Worker object used by Sema to execute analysis-based
 //  warnings on a function, method, or block.
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 6022e4a838e8aa..39d9eeac43429e 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -586,21 +586,20 @@ void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
 }
 
 // Generate diagnostics when adding or removing effects in a type conversion.
-void Sema::diagnoseFunctionEffectConversion(QualType DstType,
-                                          QualType SrcType,
-                                          SourceLocation Loc)
-{
-  llvm::outs() << "diagnoseFunctionEffectConversion " << SrcType << " -> " << DstType << "\n";
+void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
+                                            SourceLocation Loc) {
+  llvm::outs() << "diagnoseFunctionEffectConversion " << SrcType << " -> "
+               << DstType << "\n";
   const auto SrcFX = FunctionEffectSet::get(*SrcType);
   const auto DstFX = FunctionEffectSet::get(*DstType);
   if (SrcFX != DstFX) {
-    const auto diffs = FunctionEffectSet::differences(SrcFX, DstFX);
-    for (const auto& item : diffs) {
-      const FunctionEffect* effect = item.first;
-      const bool adding = item.second;
-      if (effect->diagnoseConversion(adding,
-        SrcType, SrcFX, DstType, DstFX)) {
-        Diag(Loc, adding ? diag::warn_invalid_add_func_effects : diag::warn_invalid_remove_func_effects) << effect->name();
+    for (const auto &Item : FunctionEffectSet::differences(SrcFX, DstFX)) {
+      const FunctionEffect *Effect = Item.first;
+      const bool Adding = Item.second;
+      if (Effect->diagnoseConversion(Adding, SrcType, SrcFX, DstType, DstFX)) {
+        Diag(Loc, Adding ? diag::warn_invalid_add_func_effects
+                         : diag::warn_invalid_remove_func_effects)
+            << Effect->name();
       }
     }
   }
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 77fdffef6382e0..f437db5661b00d 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3925,12 +3925,12 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
   const auto OldFX = Old->getFunctionEffects();
   const auto NewFX = New->getFunctionEffects();  
   if (OldFX != NewFX) {
-    const auto diffs = FunctionEffectSet::differences(OldFX, NewFX);
-    for (const auto& item : diffs) {
-      const FunctionEffect* effect = item.first;
-      const bool adding = item.second;
-      if (effect->diagnoseRedeclaration(adding, *Old, OldFX, *New, NewFX)) {
-        Diag(New->getLocation(), diag::warn_mismatched_func_effect_redeclaration) << effect->name();
+    const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
+    for (const auto& Item : Diffs) {
+      const FunctionEffect* Effect = Item.first;
+      const bool Adding = Item.second;
+      if (Effect->diagnoseRedeclaration(Adding, *Old, OldFX, *New, NewFX)) {
+        Diag(New->getLocation(), diag::warn_mismatched_func_effect_redeclaration) << Effect->name();
         Diag(Old->getLocation(), diag::note_previous_declaration);
       }
     }
@@ -11162,14 +11162,14 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX)
 
   // Filter out declarations that the FunctionEffect analysis should skip
   // and not verify. (??? Is this the optimal order in which to test ???)
-  bool effectsNeedVerification = false;
+  bool FXNeedVerification = false;
   for (const auto *Effect : FX) {
-    if (Effect->getFlags() & FunctionEffect::kRequiresVerification) {
+    if (Effect->flags() & FunctionEffect::kRequiresVerification) {
       AllEffectsToVerify.insert(Effect);
-      effectsNeedVerification = true;
+      FXNeedVerification = true;
     }
   }
-  if (!effectsNeedVerification) {
+  if (!FXNeedVerification) {
     return;
   }
 
@@ -15789,12 +15789,6 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
   else
     FD = cast<FunctionDecl>(D);
 
-  auto *Canon = FD->getCanonicalDecl();
-
-  // llvm::outs() << "** ActOnStartOfFunctionDef " << FD->getName() << 
-  //   " " << FD << " " << Canon << " " << FD->getType() << "\n";
-  // getNameForDiagnostic
-
   // Do not push if it is a lambda because one is already pushed when building
   // the lambda in ActOnStartOfLambdaDefinition().
   if (!isLambdaCallOperator(FD))
@@ -15995,9 +15989,8 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
       getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation)
     Diag(FD->getLocation(), diag::warn_function_def_in_objc_container);
 
-  const auto FX = FD->getCanonicalDecl()->getFunctionEffects();
-  llvm::outs() << "^^ " << FX.size() << " effects\n";
-  if (FX) {
+  // TODO: does this really need to be getCanonicalDecl()?
+  if (const auto FX = FD->getCanonicalDecl()->getFunctionEffects()) {
     CheckAddCallableWithEffects(FD, FX);
   }
 
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 12f7869441c9be..fd27ccd5c1dd1d 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -403,22 +403,22 @@ bool Sema::checkBoolExprArgumentAttr(const ParsedAttr &AL, unsigned ArgNum,
   if (AL.isInvalid()) {
     return false;
   }
-  Expr* ArgExpr = AL.getArgAsExpr(ArgNum);
-  SourceLocation errorLoc{ AL.getLoc() };
+  Expr *ArgExpr = AL.getArgAsExpr(ArgNum);
+  SourceLocation ErrorLoc(AL.getLoc());
 
   if (AL.isArgIdent(ArgNum)) {
-    IdentifierLoc * IL = AL.getArgAsIdent(ArgNum);
-    errorLoc = IL->Loc;
+    IdentifierLoc *IL = AL.getArgAsIdent(ArgNum);
+    ErrorLoc = IL->Loc;
   } else if (ArgExpr != nullptr) {
-    auto maybeVal = ArgExpr->getIntegerConstantExpr(Context, &errorLoc);
-    if (maybeVal) {
-      Value = maybeVal->getBoolValue();
+    if (const std::optional<llvm::APSInt> MaybeVal =
+        ArgExpr->getIntegerConstantExpr(Context, &ErrorLoc)) {
+      Value = MaybeVal->getBoolValue();
       return true;
     }
   }
 
   AL.setInvalid();
-  Diag(errorLoc, diag::err_attribute_argument_n_type)
+  Diag(ErrorLoc, diag::err_attribute_argument_n_type)
     << AL << ArgNum << AANT_ArgumentConstantExpr;
   return false;
 }
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index dac5d5f3e5c1e6..7533d3f9054a27 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18321,24 +18321,25 @@ bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
     return true;
   }
 
-  // Virtual overrides must have the same or stronger performance annotation.
+  // Virtual overrides: check for matching effects.
   const auto OldFX = Old->getFunctionEffects();
   const auto NewFX = New->getFunctionEffects();
 
   if (OldFX != NewFX) {
-    const auto diffs = FunctionEffectSet::differences(OldFX, NewFX);
+    const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
     bool AnyDiags = false;
 
-    for (const auto& item : diffs) {
-      const FunctionEffect* effect = item.first;
-      const bool adding = item.second;
-      if (effect->diagnoseMethodOverride(adding, *Old, OldFX, *New, NewFX)) {
-        Diag(New->getLocation(), diag::warn_mismatched_func_effect_override) << effect->name();
+    for (const auto& Item : Diffs) {
+      const FunctionEffect* Effect = Item.first;
+      const bool Adding = Item.second;
+      if (Effect->diagnoseMethodOverride(Adding, *Old, OldFX, *New, NewFX)) {
+        Diag(New->getLocation(), diag::warn_mismatched_func_effect_override) << Effect->name();
         Diag(Old->getLocation(), diag::note_overridden_virtual_function);
         AnyDiags = true;
       }
     }
-    if (AnyDiags) return true;
+    if (AnyDiags)
+      return true;
   }
 
   CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv();
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 2bc6b5b3880a8e..c4f87be129fdca 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -213,7 +213,7 @@ namespace {
 
     // Flags to diagnose illegal permutations of nolock(cond) and noalloc(cond).
     // Manual logic for finding previous attributes would be more complex,
-    // unless we transoformed nolock/noalloc(false) into distinct separate
+    // unless we transformed nolock/noalloc(false) into distinct separate
     // attributes from the ones which are parsed.
     unsigned char parsedNolock : 2;
     unsigned char parsedNoalloc : 2;
@@ -7942,16 +7942,12 @@ static Attr *getCCTypeAttr(ASTContext &Ctx, ParsedAttr &Attr) {
 }
 
 static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
-  ParsedAttr &attr, QualType &type, FunctionTypeUnwrapper& unwrapped)
-{
+                                        ParsedAttr &PAttr, QualType &type,
+                                        FunctionTypeUnwrapper &unwrapped) {
   // Values of nolockState / noallocState
-  enum {
-    kNotSeen   = 0,
-    kSeenFalse = 1,
-    kSeenTrue  = 2
-  };
+  enum { kNotSeen = 0, kSeenFalse = 1, kSeenTrue = 2 };
 
-  const bool isNoLock = attr.getKind() == ParsedAttr::AT_NoLock;
+  const bool isNoLock = PAttr.getKind() == ParsedAttr::AT_NoLock;
   Sema &S = state.getSema();
 
   // Delay if this is not a function type.
@@ -7967,9 +7963,9 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
 
   // Parse the conditional expression, if any
   bool Cond = true; // default
-  if (attr.getNumArgs() > 0) {
-    if (!S.checkBoolExprArgumentAttr(attr, 0, Cond)) {
-      attr.setInvalid();
+  if (PAttr.getNumArgs() > 0) {
+    if (!S.checkBoolExprArgumentAttr(PAttr, 0, Cond)) {
+      PAttr.setInvalid();
       return false;
     }
   }
@@ -7978,12 +7974,11 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
 
   auto incompatible = [&](StringRef attrTrue, StringRef attrFalse) {
     Sema &S = state.getSema();
-    S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
-        << attrTrue << attrFalse
-        << false;
+    S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
+        << attrTrue << attrFalse << false;
     // we don't necessarily have the location of the previous attribute,
     // so no note.
-    attr.setInvalid();
+    PAttr.setInvalid();
     return true;
   };
 
@@ -8013,9 +8008,10 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
     }
     state.setParsedNoalloc(newState);
   }
-  
+
   if (!Cond) {
-    // nolock(false) and noalloc(false) are represented as sugar, with AttributedType
+    // nolock(false) and noalloc(false) are represented as sugar, with
+    // AttributedType
     Attr *A = nullptr;
     if (isNoLock) {
       A = NoLockAttr::Create(S.Context, false);
@@ -8026,17 +8022,17 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
     return true;
   }
 
-  const FunctionEffect* Effect = nullptr;
+  const FunctionEffect *Effect = nullptr;
   if (isNoLock) {
     Effect = &NoLockNoAllocEffect::nolock_instance();
   } else {
     Effect = &NoLockNoAllocEffect::noalloc_instance();
   }
 
-  MutableFunctionEffectSet newEffectSet{ Effect };
+  MutableFunctionEffectSet newEffectSet{Effect};
   if (EPI.FunctionEffects) {
     // Preserve all previous effects - except noalloc, when we are adding nolock
-    for (const auto* effect : EPI.FunctionEffects) {
+    for (const auto *effect : EPI.FunctionEffects) {
       if (!(isNoLock && effect->type() == FunctionEffect::kNoAllocTrue))
         newEffectSet.insert(effect);
     }
@@ -8044,7 +8040,7 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
 
   EPI.FunctionEffects = FunctionEffectSet::create(newEffectSet);
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
-                                              FPT->getParamTypes(), EPI);
+                                               FPT->getParamTypes(), EPI);
   type = unwrapped.wrap(S, newtype->getAs<FunctionType>());
   return true;
 }
@@ -8362,8 +8358,8 @@ static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
     return true;
   }
 
-  if (attr.getKind() == ParsedAttr::AT_NoLock
-   || attr.getKind() == ParsedAttr::AT_NoAlloc) {
+  if (attr.getKind() == ParsedAttr::AT_NoLock ||
+      attr.getKind() == ParsedAttr::AT_NoAlloc) {
     return handleNoLockNoAllocTypeAttr(state, attr, type, unwrapped);
   }
 
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
new file mode 100644
index 00000000000000..a63750f5ca18ef
--- /dev/null
+++ b/clang/test/Sema/attr-nolock-wip.cpp
@@ -0,0 +1,19 @@
+// RUN: %clang_cc1 -fsyntax-only -fblocks -verify %s
+// R UN: %clang_cc1 -fsyntax-only -fblocks -verify -x c -std=c23 %s
+
+#if !__has_attribute(clang_nolock)
+#error "the 'nolock' attribute is not available"
+#endif
+
+void unannotated(void);
+void nolock(void) [[clang::nolock]];
+void noalloc(void) [[clang::noalloc]];
+void type_conversions(void)
+{
+	// It's fine to remove a performance constraint.
+	void (*fp_plain)(void);
+
+	fp_plain = unannotated;
+	fp_plain = nolock;
+	fp_plain = noalloc;
+}
diff --git a/clang/test/Sema/attr-nolock2.cpp b/clang/test/Sema/attr-nolock2.cpp
index 9c494dcdd581db..d2a35453b08bb7 100644
--- a/clang/test/Sema/attr-nolock2.cpp
+++ b/clang/test/Sema/attr-nolock2.cpp
@@ -9,8 +9,6 @@
 #error "the 'nolock' attribute is not available"
 #endif
 
-#if 1 // TEMP_DISABLE
-
 // --- ATTRIBUTE SYNTAX: COMBINATIONS ---
 // Check invalid combinations of nolock/noalloc attributes
 void nl_true_false_1(void) [[clang::nolock(true)]] [[clang::nolock(false)]]; // expected-error {{nolock(true) and nolock(false) attributes are not compatible}}
@@ -84,5 +82,3 @@ int f3(void);
 // redeclaration with a stronger constraint is OK.
 int f3(void) [[clang::noalloc]]; // expected-note {{previous declaration is here}}
 int f3(void) { return 42; } // expected-warning {{attribute 'noalloc' on function does not match previous declaration}}
-
-#endif // TEMP_DISABLE
diff --git a/clang/test/Sema/attr-nolock3.cpp b/clang/test/Sema/attr-nolock3.cpp
index cfe52da16447c1..65d610f796f87f 100644
--- a/clang/test/Sema/attr-nolock3.cpp
+++ b/clang/test/Sema/attr-nolock3.cpp
@@ -5,7 +5,6 @@
 #endif
 
 // --- CONSTRAINTS ---
-#if 0 // TEMP_DISABLE
 
 void nl1() [[clang::nolock]]
 {
@@ -129,10 +128,7 @@ void nl10(
 	fp2();
 }
 
-#endif // TEMP_DISABLE
-
-// --- PLAYGROUND ---
-
+// Interactions with nolock(false)
 void nl11_no_inference() [[clang::nolock(false)]] // expected-note {{'nl11_no_inference' does not permit inference of 'nolock'}}
 {
 }
@@ -141,4 +137,3 @@ void nl11() [[clang::nolock]]
 {
 	nl11_no_inference(); // expected-warning {{'nolock' function 'nl11' must not call non-'nolock' function 'nl11_no_inference'}}
 }
-

>From 8aaeeb27ef50557ed56839db7956c1b6e69ba318 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 12 Mar 2024 14:36:23 -0700
Subject: [PATCH 03/40] squash me

---
 clang/lib/AST/Type.cpp              |  4 ++--
 clang/lib/Sema/Sema.cpp             |  3 ++-
 clang/lib/Sema/SemaOverload.cpp     |  5 +++--
 clang/test/Sema/attr-nolock-wip.cpp | 11 +++++++++--
 4 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 998360db3c5dd0..8cc4bc42210f99 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -4985,12 +4985,12 @@ std::string NoLockNoAllocEffect::attribute() const {
   return std::string{"__attribute__((clang_"} + name().str() + "))";
 }
 
-bool NoLockNoAllocEffect::diagnoseConversion(bool adding, QualType OldType,
+bool NoLockNoAllocEffect::diagnoseConversion(bool Adding, QualType OldType,
                                              FunctionEffectSet OldFX,
                                              QualType NewType,
                                              FunctionEffectSet NewFX) const {
   // noalloc can't be added (spoofed) during a conversion, unless we have nolock
-  if (adding) {
+  if (Adding) {
     if (!isNoLock()) {
       for (const auto *Effect : OldFX) {
         if (Effect->type() == kNoLockTrue)
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 39d9eeac43429e..d3b9b048230f9c 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -588,7 +588,7 @@ void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
 // Generate diagnostics when adding or removing effects in a type conversion.
 void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
                                             SourceLocation Loc) {
-  llvm::outs() << "diagnoseFunctionEffectConversion " << SrcType << " -> "
+  llvm::outs() << "diagnoseFunctionEffectConversion: " << SrcType << " -> "
                << DstType << "\n";
   const auto SrcFX = FunctionEffectSet::get(*SrcType);
   const auto DstFX = FunctionEffectSet::get(*DstType);
@@ -682,6 +682,7 @@ ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
   diagnoseNullableToNonnullConversion(Ty, E->getType(), E->getBeginLoc());
   diagnoseZeroToNullptrConversion(Kind, E);
   if (!isCast(CCK) && !E->isNullPointerConstant(Context, Expr::NPC_NeverValueDependent /* ???*/)) {
+    llvm::outs() << "Sema::ImpCastExprToType\n";
     diagnoseFunctionEffectConversion(Ty, E->getType(), E->getBeginLoc());
   }
 
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 8f1563e7884429..80a2e6a6456d0a 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1787,7 +1787,7 @@ ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType,
 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
                                 QualType &ResultTy) {
 
-  llvm::outs() << "IsFunctionConversion " << FromType << " " << ToType << "\n";
+  llvm::outs() << "IsFunctionConversion: " << FromType << " -> " << ToType << "\n";
 
   if (Context.hasSameUnqualifiedType(FromType, ToType))
     return false;
@@ -1827,6 +1827,7 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
     if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
       return false;
   }
+  llvm::outs() << "  didn't exit early\n";
 
   const auto *FromFn = cast<FunctionType>(CanFrom);
   FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
@@ -1879,7 +1880,7 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
     auto FromFX = FromFPT->getFunctionEffects();
     auto ToFX = ToFPT->getFunctionEffects();
     if (FromFX != ToFX) {
-      llvm::outs() << "IsFunctionConversion effects change " << FromType << " -> " << ToType << "\n";
+      llvm::outs() << "  effects change: " << FromType << " -> " << ToType << "\n";
 
       //const auto MergedFX = FunctionEffectSet::getIntersection(FromFX, ToFX);
       // TODO: diagnose conflicts
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
index a63750f5ca18ef..c30d0f42e37aee 100644
--- a/clang/test/Sema/attr-nolock-wip.cpp
+++ b/clang/test/Sema/attr-nolock-wip.cpp
@@ -8,12 +8,19 @@
 void unannotated(void);
 void nolock(void) [[clang::nolock]];
 void noalloc(void) [[clang::noalloc]];
+
+
+void callthis(void (*fp)(void));
+
+
 void type_conversions(void)
 {
+// 	callthis(nolock);
+
 	// It's fine to remove a performance constraint.
 	void (*fp_plain)(void);
 
-	fp_plain = unannotated;
+// 	fp_plain = unannotated;
 	fp_plain = nolock;
-	fp_plain = noalloc;
+// 	fp_plain = noalloc;
 }

>From eb204dff79817667c65f09bbd38ece245f50b99e Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 12 Mar 2024 14:41:16 -0700
Subject: [PATCH 04/40] apply the in-tree clang-format (which seems subtly
 different from my system's local one)

---
 clang/include/clang/AST/Type.h           | 11 +++++-----
 clang/lib/AST/ASTContext.cpp             | 23 ++++++++++++--------
 clang/lib/Sema/AnalysisBasedWarnings.cpp | 27 ++++++++++++------------
 clang/lib/Sema/Sema.cpp                  |  3 ++-
 clang/lib/Sema/SemaDecl.cpp              | 23 ++++++++++----------
 clang/lib/Sema/SemaDeclAttr.cpp          |  7 +++---
 clang/lib/Sema/SemaDeclCXX.cpp           |  7 +++---
 clang/lib/Sema/SemaExprCXX.cpp           |  3 ++-
 clang/lib/Sema/SemaOverload.cpp          | 10 +++++----
 9 files changed, 62 insertions(+), 52 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index de21561ce5dcad..779c72ab63648d 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4360,8 +4360,8 @@ class FunctionProtoType final
   //   hasFunctionEffects() is true.
   //
   // * Optionally a Qualifiers object to represent extra qualifiers that can't
-  //   be represented by FunctionTypeBitfields.FastTypeQuals. Present if and only
-  //   if hasExtQualifiers() is true.
+  //   be represented by FunctionTypeBitfields.FastTypeQuals. Present if and
+  //   only if hasExtQualifiers() is true.
   //
   // The optional FunctionTypeExtraBitfields has to be before the data
   // related to the exception specification since it contains the number
@@ -4435,8 +4435,7 @@ class FunctionProtoType final
 
     bool requiresFunctionProtoTypeExtraBitfields() const {
       return ExceptionSpec.Type == EST_Dynamic ||
-             requiresFunctionProtoTypeArmAttributes() ||
-             FunctionEffects;
+             requiresFunctionProtoTypeArmAttributes() || FunctionEffects;
     }
 
     bool requiresFunctionProtoTypeArmAttributes() const {
@@ -7984,7 +7983,7 @@ class FunctionEffect {
                                      const FunctionDecl &NewFunction,
                                      FunctionEffectSet NewFX) const;
 
-  /// Return true if adding or removing the effect in a C++ virtual method 
+  /// Return true if adding or removing the effect in a C++ virtual method
   /// override should generate a diagnostic.
   virtual bool diagnoseMethodOverride(bool Adding,
                                       const CXXMethodDecl &OldMethod,
@@ -7994,7 +7993,7 @@ class FunctionEffect {
 
   /// Return true if the effect is allowed to be inferred on the specified Decl
   /// (may be a FunctionDecl or BlockDecl). Only used if the effect has
-  /// kInferrableOnCallees flag set. Example: This allows nolock(false) to 
+  /// kInferrableOnCallees flag set. Example: This allows nolock(false) to
   /// prevent inference for the function.
   virtual bool canInferOnDecl(const Decl *Caller,
                               FunctionEffectSet CallerFX) const;
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 43fccb117a897d..68f2ac3e1329f8 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -4502,13 +4502,12 @@ QualType ASTContext::getFunctionTypeInternal(
   size_t Size = FunctionProtoType::totalSizeToAlloc<
       QualType, SourceLocation, FunctionType::FunctionTypeExtraBitfields,
       FunctionType::FunctionTypeArmAttributes, FunctionType::ExceptionType,
-      Expr *, FunctionDecl *, FunctionProtoType::ExtParameterInfo, 
+      Expr *, FunctionDecl *, FunctionProtoType::ExtParameterInfo,
       FunctionEffectSet, Qualifiers>(
       NumArgs, EPI.Variadic, EPI.requiresFunctionProtoTypeExtraBitfields(),
       EPI.requiresFunctionProtoTypeArmAttributes(), ESH.NumExceptionType,
       ESH.NumExprPtr, ESH.NumFunctionDeclPtr,
-      EPI.ExtParameterInfos ? NumArgs : 0,
-      EPI.FunctionEffects ? 1 : 0,
+      EPI.ExtParameterInfos ? NumArgs : 0, EPI.FunctionEffects ? 1 : 0,
       EPI.TypeQuals.hasNonFastQualifiers() ? 1 : 0);
 
   auto *FTP = (FunctionProtoType *)Allocate(Size, alignof(FunctionProtoType));
@@ -10440,8 +10439,10 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
   FunctionEffectSet FromFX, ToFX;
   std::optional<FunctionEffectSet> MergedFX;
 
-  if (lproto) ToFX = lproto->getFunctionEffects();
-  if (rproto) FromFX = rproto->getFunctionEffects();
+  if (lproto)
+    ToFX = lproto->getFunctionEffects();
+  if (rproto)
+    FromFX = rproto->getFunctionEffects();
   if (ToFX != FromFX) {
     // We want the intersection of the effects...
     MergedFX = FunctionEffectSet::create(FromFX & ToFX);
@@ -10499,8 +10500,10 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
     }
 
     if (!MergedFX) { // effects changed so we can't return either side unaltered
-      if (allLTypes) return lhs;
-      if (allRTypes) return rhs;
+      if (allLTypes)
+        return lhs;
+      if (allRTypes)
+        return rhs;
     }
 
     FunctionProtoType::ExtProtoInfo EPI = lproto->getExtProtoInfo();
@@ -10543,8 +10546,10 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
     }
 
     if (!MergedFX) { // effects changed so we can't return either side unaltered
-      if (allLTypes) return lhs;
-      if (allRTypes) return rhs;
+      if (allLTypes)
+        return lhs;
+      if (allRTypes)
+        return rhs;
     }
 
     FunctionProtoType::ExtProtoInfo EPI = proto->getExtProtoInfo();
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 69417b10049e97..bdc3aa906541be 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -3196,8 +3196,7 @@ class Analyzer {
           CurrentCaller(CurrentCaller) {}
 
     // -- Entry point --
-    void run()
-    {
+    void run() {
       // The target function itself may have some implicit code paths beyond the
       // body: member and base constructors and destructors. Visit these first.
       if (const auto *FD = dyn_cast<const FunctionDecl>(CurrentCaller.CDecl)) {
@@ -3225,8 +3224,8 @@ class Analyzer {
     // flags include the specified flag receive a diagnostic. \p Flag describes
     // the construct.
     void diagnoseLanguageConstruct(FunctionEffect::FlagBit Flag, DiagnosticID D,
-                       SourceLocation Loc, const Decl *Callee = nullptr)
-    {
+                                   SourceLocation Loc,
+                                   const Decl *Callee = nullptr) {
       // If there are ANY declared verifiable effects holding the flag, store
       // just one diagnostic.
       for (auto *Effect : CurrentFunction.DeclaredVerifiableEffects) {
@@ -3247,8 +3246,8 @@ class Analyzer {
     void addDiagnosticInner(bool Inferring, const FunctionEffect *Effect,
                             DiagnosticID D, SourceLocation Loc,
                             const Decl *Callee = nullptr) {
-      CurrentFunction.checkAddDiagnostic(Inferring, 
-        Diagnostic(Effect, D, Loc, Callee));
+      CurrentFunction.checkAddDiagnostic(Inferring,
+                                         Diagnostic(Effect, D, Loc, Callee));
     }
 
     // Here we have a call to a Decl, either explicitly via a CallExpr or some
@@ -3334,14 +3333,14 @@ class Analyzer {
     bool shouldWalkTypesOfTypeLocs() const { return false; }
 
     bool VisitCXXThrowExpr(CXXThrowExpr *Throw) {
-      diagnoseLanguageConstruct(FunctionEffect::kExcludeThrow, DiagnosticID::Throws,
-                                Throw->getThrowLoc());
+      diagnoseLanguageConstruct(FunctionEffect::kExcludeThrow,
+                                DiagnosticID::Throws, Throw->getThrowLoc());
       return Proceed;
     }
 
     bool VisitCXXCatchStmt(CXXCatchStmt *Catch) {
-      diagnoseLanguageConstruct(FunctionEffect::kExcludeCatch, DiagnosticID::Catches,
-                                Catch->getCatchLoc());
+      diagnoseLanguageConstruct(FunctionEffect::kExcludeCatch,
+                                DiagnosticID::Catches, Catch->getCatchLoc());
       return Proceed;
     }
 
@@ -3394,7 +3393,8 @@ class Analyzer {
 
       if (Var->isStaticLocal()) {
         diagnoseLanguageConstruct(FunctionEffect::kExcludeStaticLocalVars,
-                                  DiagnosticID::HasStaticLocal, Var->getLocation());
+                                  DiagnosticID::HasStaticLocal,
+                                  Var->getLocation());
       }
 
       const QualType::DestructionKind DK =
@@ -3493,7 +3493,8 @@ class Analyzer {
           // At least on macOS, thread-local variables are initialized on
           // first access.
           diagnoseLanguageConstruct(FunctionEffect::kExcludeThreadLocalVars,
-                                    DiagnosticID::AccessesThreadLocal, E->getLocation());
+                                    DiagnosticID::AccessesThreadLocal,
+                                    E->getLocation());
         }
       }
       return Proceed;
@@ -3770,7 +3771,7 @@ void clang::sema::AnalysisBasedWarnings::IssueWarnings(
   }
 
   // TODO: skip this if the warning isn't enabled.
-  FXAnalysis::Analyzer{ S }.run(*TU);
+  FXAnalysis::Analyzer{S}.run(*TU);
 }
 
 void clang::sema::AnalysisBasedWarnings::IssueWarnings(
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index d3b9b048230f9c..b120ed22246961 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -681,7 +681,8 @@ ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
 
   diagnoseNullableToNonnullConversion(Ty, E->getType(), E->getBeginLoc());
   diagnoseZeroToNullptrConversion(Kind, E);
-  if (!isCast(CCK) && !E->isNullPointerConstant(Context, Expr::NPC_NeverValueDependent /* ???*/)) {
+  if (!isCast(CCK) && !E->isNullPointerConstant(
+                          Context, Expr::NPC_NeverValueDependent /* ???*/)) {
     llvm::outs() << "Sema::ImpCastExprToType\n";
     diagnoseFunctionEffectConversion(Ty, E->getType(), E->getBeginLoc());
   }
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index f437db5661b00d..d407018adfde60 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3923,28 +3923,30 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
   }
 
   const auto OldFX = Old->getFunctionEffects();
-  const auto NewFX = New->getFunctionEffects();  
+  const auto NewFX = New->getFunctionEffects();
   if (OldFX != NewFX) {
     const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
-    for (const auto& Item : Diffs) {
-      const FunctionEffect* Effect = Item.first;
+    for (const auto &Item : Diffs) {
+      const FunctionEffect *Effect = Item.first;
       const bool Adding = Item.second;
       if (Effect->diagnoseRedeclaration(Adding, *Old, OldFX, *New, NewFX)) {
-        Diag(New->getLocation(), diag::warn_mismatched_func_effect_redeclaration) << Effect->name();
+        Diag(New->getLocation(),
+             diag::warn_mismatched_func_effect_redeclaration)
+            << Effect->name();
         Diag(Old->getLocation(), diag::note_previous_declaration);
       }
     }
 
     const auto MergedFX = OldFX | NewFX;
 
-    // Having diagnosed any problems, prevent further errors by applying the merged set of effects
-    // to both declarations.
-    auto applyMergedFX = [&](FunctionDecl* FD) {
+    // Having diagnosed any problems, prevent further errors by applying the
+    // merged set of effects to both declarations.
+    auto applyMergedFX = [&](FunctionDecl *FD) {
       const auto *FPT = FD->getType()->getAs<FunctionProtoType>();
       FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
       EPI.FunctionEffects = MergedFX;
       QualType ModQT = Context.getFunctionType(FD->getReturnType(),
-                                                  FPT->getParamTypes(), EPI);
+                                               FPT->getParamTypes(), EPI);
 
       FD->setType(ModQT);
     };
@@ -11136,8 +11138,7 @@ Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
 
 // Should only be called when getFunctionEffects() returns a non-empty set.
 // Decl should be a FunctionDecl or BlockDecl.
-void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX)
-{
+void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
   if (!D->hasBody()) {
     if (const auto *FD = D->getAsFunction()) {
       if (!FD->willHaveBody()) {
@@ -11148,7 +11149,7 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX)
 
   if (Diags.getIgnoreAllWarnings() ||
       (Diags.getSuppressSystemWarnings() &&
-        SourceMgr.isInSystemHeader(D->getLocation())))
+       SourceMgr.isInSystemHeader(D->getLocation())))
     return;
 
   if (hasUncompilableErrorOccurred())
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index fd27ccd5c1dd1d..7805922c66b57a 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -398,8 +398,7 @@ bool Sema::checkStringLiteralArgumentAttr(const ParsedAttr &AL, unsigned ArgNum,
 /// Check if the argument \p ArgNum of \p Attr is a compile-time constant
 /// integer (boolean) expression. If not, emit an error and return false.
 bool Sema::checkBoolExprArgumentAttr(const ParsedAttr &AL, unsigned ArgNum,
-                                    bool &Value)
-{
+                                     bool &Value) {
   if (AL.isInvalid()) {
     return false;
   }
@@ -411,7 +410,7 @@ bool Sema::checkBoolExprArgumentAttr(const ParsedAttr &AL, unsigned ArgNum,
     ErrorLoc = IL->Loc;
   } else if (ArgExpr != nullptr) {
     if (const std::optional<llvm::APSInt> MaybeVal =
-        ArgExpr->getIntegerConstantExpr(Context, &ErrorLoc)) {
+            ArgExpr->getIntegerConstantExpr(Context, &ErrorLoc)) {
       Value = MaybeVal->getBoolValue();
       return true;
     }
@@ -419,7 +418,7 @@ bool Sema::checkBoolExprArgumentAttr(const ParsedAttr &AL, unsigned ArgNum,
 
   AL.setInvalid();
   Diag(ErrorLoc, diag::err_attribute_argument_n_type)
-    << AL << ArgNum << AANT_ArgumentConstantExpr;
+      << AL << ArgNum << AANT_ArgumentConstantExpr;
   return false;
 }
 
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 7533d3f9054a27..2f9a4a14155fb4 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18329,11 +18329,12 @@ bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
     const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
     bool AnyDiags = false;
 
-    for (const auto& Item : Diffs) {
-      const FunctionEffect* Effect = Item.first;
+    for (const auto &Item : Diffs) {
+      const FunctionEffect *Effect = Item.first;
       const bool Adding = Item.second;
       if (Effect->diagnoseMethodOverride(Adding, *Old, OldFX, *New, NewFX)) {
-        Diag(New->getLocation(), diag::warn_mismatched_func_effect_override) << Effect->name();
+        Diag(New->getLocation(), diag::warn_mismatched_func_effect_override)
+            << Effect->name();
         Diag(Old->getLocation(), diag::note_overridden_virtual_function);
         AnyDiags = true;
       }
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 50007d4e1de119..e698139e55a239 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -4951,7 +4951,8 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
 
     // TODO: This generates a redundant diagnostic for:
     // void (^nl_block0)() NOLOCK = ^(){};
-    // if (!From->isNullPointerConstant(Context, Expr::NPC_NeverValueDependent /* ???*/))
+    // if (!From->isNullPointerConstant(Context, Expr::NPC_NeverValueDependent
+    // /* ???*/))
     //   diagnoseFunctionEffectConversion(ToType, InitialFromType,
     //                                         From->getBeginLoc());
   }
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 80a2e6a6456d0a..e34aa7e970d5dc 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1787,7 +1787,8 @@ ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType,
 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
                                 QualType &ResultTy) {
 
-  llvm::outs() << "IsFunctionConversion: " << FromType << " -> " << ToType << "\n";
+  llvm::outs() << "IsFunctionConversion: " << FromType << " -> " << ToType
+               << "\n";
 
   if (Context.hasSameUnqualifiedType(FromType, ToType))
     return false;
@@ -1880,10 +1881,11 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
     auto FromFX = FromFPT->getFunctionEffects();
     auto ToFX = ToFPT->getFunctionEffects();
     if (FromFX != ToFX) {
-      llvm::outs() << "  effects change: " << FromType << " -> " << ToType << "\n";
+      llvm::outs() << "  effects change: " << FromType << " -> " << ToType
+                   << "\n";
 
-      //const auto MergedFX = FunctionEffectSet::getIntersection(FromFX, ToFX);
-      // TODO: diagnose conflicts
+      // const auto MergedFX = FunctionEffectSet::getIntersection(FromFX, ToFX);
+      //  TODO: diagnose conflicts
 
       FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
       ExtInfo.FunctionEffects = ToFX;

>From 3b0277bedd5391a17012b69135ac1a26c0a236a6 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 13 Mar 2024 08:08:52 -0700
Subject: [PATCH 05/40] Address most of the low-hanging fruit in the initial
 review feedback.

---
 clang/include/clang/AST/Type.h                | 44 +++++----
 clang/include/clang/Basic/Attr.td             | 10 +--
 clang/lib/AST/Type.cpp                        | 41 +++++----
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 46 +++++-----
 clang/lib/Sema/SemaDecl.cpp                   |  9 +-
 clang/lib/Sema/SemaType.cpp                   | 44 +++++----
 ...olock3.cpp => attr-nolock-constraints.cpp} |  2 +
 ...ttr-nolock.cpp => attr-nolock-parsing.cpp} | 47 +++++++---
 clang/test/Sema/attr-nolock-sema.cpp          | 89 +++++++++++++++++++
 clang/test/Sema/attr-nolock-wip.cpp           | 12 +--
 clang/test/Sema/attr-nolock2.cpp              | 84 -----------------
 11 files changed, 228 insertions(+), 200 deletions(-)
 rename clang/test/Sema/{attr-nolock3.cpp => attr-nolock-constraints.cpp} (96%)
 rename clang/test/Sema/{attr-nolock.cpp => attr-nolock-parsing.cpp} (67%)
 create mode 100644 clang/test/Sema/attr-nolock-sema.cpp
 delete mode 100644 clang/test/Sema/attr-nolock2.cpp

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 779c72ab63648d..63b78d75089f9e 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4274,10 +4274,6 @@ class FunctionEffectSet {
 
   ArrayRef<const FunctionEffect *> items() const { return {begin(), end()}; }
 
-  // Since iterators are non-trivial and sets are very often empty,
-  // encourage short-circuiting loops for the empty set.
-  // void for_each(llvm::function_ref<void(const FunctionEffect*)> func) const;
-
   bool operator==(const FunctionEffectSet &other) const {
     return Impl == other.Impl;
   }
@@ -7915,37 +7911,39 @@ class CXXMethodDecl;
 /// Represents an abstract function effect.
 class FunctionEffect {
 public:
-  enum EffectType {
-    kGeneric,
-    kNoLockTrue,
-    kNoAllocTrue,
+  enum class Type : unsigned char {
+    NoLockTrue,
+    NoAllocTrue,
   };
 
   /// Flags describing behaviors of the effect.
+  // (Why not a struct with bitfields? There's one function that would like to
+  // test a caller-specified bit. There are some potential optimizations that
+  // would OR together the bits of multiple effects.)
   using Flags = unsigned;
   enum FlagBit : unsigned {
     // Some effects require verification, e.g. nolock(true); others might not?
-    // (no example yet)
-    kRequiresVerification = 0x1,
+    // (no example yet; TODO: maybe always true, vestigial from nolock(false)).
+    FE_RequiresVerification = 0x1,
 
     // Does this effect want to verify all function calls originating in
-    // functions having this effect?
-    kVerifyCalls = 0x2,
+    // functions having this effect? TODO: maybe always true, vestigial.
+    FE_VerifyCalls = 0x2,
 
     // Can verification inspect callees' implementations? (e.g. nolock: yes,
     // tcb+types: no)
-    kInferrableOnCallees = 0x4,
+    FE_InferrableOnCallees = 0x4,
 
     // Language constructs which effects can diagnose as disallowed.
-    kExcludeThrow = 0x8,
-    kExcludeCatch = 0x10,
-    kExcludeObjCMessageSend = 0x20,
-    kExcludeStaticLocalVars = 0x40,
-    kExcludeThreadLocalVars = 0x80
+    FE_ExcludeThrow = 0x8,
+    FE_ExcludeCatch = 0x10,
+    FE_ExcludeObjCMessageSend = 0x20,
+    FE_ExcludeStaticLocalVars = 0x40,
+    FE_ExcludeThreadLocalVars = 0x80
   };
 
 private:
-  const EffectType Type_;
+  const Type Type_;
   const Flags Flags_;
   const char *Name;
 
@@ -7953,12 +7951,12 @@ class FunctionEffect {
   using CalleeDeclOrType =
       llvm::PointerUnion<const Decl *, const FunctionProtoType *>;
 
-  FunctionEffect(EffectType T, Flags F, const char *Name)
+  FunctionEffect(Type T, Flags F, const char *Name)
       : Type_(T), Flags_(F), Name(Name) {}
   virtual ~FunctionEffect();
 
   /// The type of the effect.
-  EffectType type() const { return Type_; }
+  Type type() const { return Type_; }
 
   /// Flags describing behaviors of the effect.
   Flags flags() const { return Flags_; }
@@ -8011,13 +8009,13 @@ class FunctionEffect {
 /// FunctionEffect subclass for nolock and noalloc (whose behaviors are close
 /// to identical).
 class NoLockNoAllocEffect : public FunctionEffect {
-  bool isNoLock() const { return type() == kNoLockTrue; }
+  bool isNoLock() const { return type() == Type::NoLockTrue; }
 
 public:
   static const NoLockNoAllocEffect &nolock_instance();
   static const NoLockNoAllocEffect &noalloc_instance();
 
-  NoLockNoAllocEffect(EffectType Type, const char *Name);
+  NoLockNoAllocEffect(Type Type, const char *Name);
   ~NoLockNoAllocEffect() override;
 
   std::string attribute() const override;
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 4033b9efb86f39..ccc8a58176c8d6 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1402,26 +1402,20 @@ def CXX11NoReturn : InheritableAttr {
   let Documentation = [CXX11NoReturnDocs];
 }
 
-def NoLock : DeclOrTypeAttr {
+def NoLock : TypeAttr {
   let Spellings = [CXX11<"clang", "nolock">,
                    C23<"clang", "nolock">,
                    GNU<"clang_nolock">];
 
-  // Subjects - not needed?
-  //let Subjects = SubjectList<[FunctionLike, Block, TypedefName], ErrorDiag>;
   let Args = [DefaultBoolArgument<"Cond", /*default*/1>];
-  let HasCustomParsing = 0;
   let Documentation = [NoLockNoAllocDocs];
 }
 
-def NoAlloc : DeclOrTypeAttr {
+def NoAlloc : TypeAttr {
   let Spellings = [CXX11<"clang", "noalloc">,
                    C23<"clang", "noalloc">,
                    GNU<"clang_noalloc">];
-  // Subjects - not needed?
-  //let Subjects = SubjectList<[FunctionLike, Block, TypedefName], ErrorDiag>;
   let Args = [DefaultBoolArgument<"Cond", /*default*/1>];
-  let HasCustomParsing = 0;
   let Documentation = [NoLockNoAllocDocs];
 }
 
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 8cc4bc42210f99..0afc61ff6de487 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3662,7 +3662,7 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   // Note that valid type pointers are never ambiguous with anything else.
   //
   // The encoding grammar begins:
-  //      type type* bool int bool
+  //      effects type type* bool int bool
   // If that final bool is true, then there is a section for the EH spec:
   //      bool type*
   // This is followed by an optional "consumed argument" section of the
@@ -3673,13 +3673,12 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   // Finally we have a trailing return type flag (bool)
   // combined with AArch64 SME Attributes, to save space:
   //      int
-  // Then add the FunctionEffects
   //
   // There is no ambiguity between the consumed arguments and an empty EH
   // spec because of the leading 'bool' which unambiguously indicates
   // whether the following bool is the EH spec or part of the arguments.
 
-  ID.AddPointer(epi.FunctionEffects.getOpaqueValue()); // TODO: Where???
+  ID.AddPointer(epi.FunctionEffects.getOpaqueValue());
 
   ID.AddPointer(Result.getAsOpaquePtr());
   for (unsigned i = 0; i != NumParams; ++i)
@@ -4961,22 +4960,22 @@ bool FunctionEffect::diagnoseFunctionCall(bool Direct, const Decl *Caller,
 }
 
 const NoLockNoAllocEffect &NoLockNoAllocEffect::nolock_instance() {
-  static NoLockNoAllocEffect global(kNoLockTrue, "nolock");
+  static NoLockNoAllocEffect global(Type::NoLockTrue, "nolock");
   return global;
 }
 
 const NoLockNoAllocEffect &NoLockNoAllocEffect::noalloc_instance() {
-  static NoLockNoAllocEffect global(kNoAllocTrue, "noalloc");
+  static NoLockNoAllocEffect global(Type::NoAllocTrue, "noalloc");
   return global;
 }
 
 // TODO: Separate flags for noalloc
-NoLockNoAllocEffect::NoLockNoAllocEffect(EffectType Ty, const char *Name)
+NoLockNoAllocEffect::NoLockNoAllocEffect(Type Ty, const char *Name)
     : FunctionEffect(Ty,
-                     kRequiresVerification | kVerifyCalls |
-                         kInferrableOnCallees | kExcludeThrow | kExcludeCatch |
-                         kExcludeObjCMessageSend | kExcludeStaticLocalVars |
-                         kExcludeThreadLocalVars,
+                     FE_RequiresVerification | FE_VerifyCalls |
+                         FE_InferrableOnCallees | FE_ExcludeThrow |
+                         FE_ExcludeCatch | FE_ExcludeObjCMessageSend |
+                         FE_ExcludeStaticLocalVars | FE_ExcludeThreadLocalVars,
                      Name) {}
 
 NoLockNoAllocEffect::~NoLockNoAllocEffect() = default;
@@ -4993,7 +4992,7 @@ bool NoLockNoAllocEffect::diagnoseConversion(bool Adding, QualType OldType,
   if (Adding) {
     if (!isNoLock()) {
       for (const auto *Effect : OldFX) {
-        if (Effect->type() == kNoLockTrue)
+        if (Effect->type() == Type::NoLockTrue)
           return false;
       }
     }
@@ -5044,10 +5043,11 @@ bool NoLockNoAllocEffect::canInferOnDecl(const Decl *Caller,
 bool NoLockNoAllocEffect::diagnoseFunctionCall(
     bool Direct, const Decl *Caller, FunctionEffectSet CallerFX,
     CalleeDeclOrType Callee, FunctionEffectSet CalleeFX) const {
-  const EffectType CallerType = type();
+  const Type CallerType = type();
   for (const auto *Effect : CalleeFX) {
-    const EffectType ET = Effect->type();
-    if (ET == CallerType || (CallerType == kNoAllocTrue && ET == kNoLockTrue)) {
+    const Type ET = Effect->type();
+    if (ET == CallerType ||
+        (CallerType == Type::NoAllocTrue && ET == Type::NoLockTrue)) {
       return false;
     }
   }
@@ -5088,11 +5088,16 @@ FunctionEffectSet::create(llvm::ArrayRef<const FunctionEffect *> Items) {
 
   // SmallSet only has contains(), so it provides no way to obtain the uniqued
   // value.
-  static std::set<UniquedAndSortedFX> uniquedFXSets;
+  // TODO: Put this in the ASTContext
+  // TODO: Try making this a DenseSet? Requires more methods on the members.
+  // static llvm::DenseSet<UniquedAndSortedFX> UniquedFXSets;
+  // Punt on this until we revisit FunctionFX.
+
+  static std::set<UniquedAndSortedFX> UniquedFXSets;
 
   // See if we already have this set.
-  const auto Iter = uniquedFXSets.find(NewSet);
-  if (Iter != uniquedFXSets.end()) {
+  const auto Iter = UniquedFXSets.find(NewSet);
+  if (Iter != UniquedFXSets.end()) {
     return FunctionEffectSet{&*Iter};
   }
 
@@ -5102,7 +5107,7 @@ FunctionEffectSet::create(llvm::ArrayRef<const FunctionEffect *> Items) {
 
   // Make a new wrapper and insert it into the set.
   NewSet = UniquedAndSortedFX(Storage, Items.size());
-  auto [InsIter, _] = uniquedFXSets.insert(NewSet);
+  auto [InsIter, _] = UniquedFXSets.insert(NewSet);
   return FunctionEffectSet(&*InsIter);
 }
 
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index bdc3aa906541be..cf9b1244e81bfd 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2519,9 +2519,10 @@ struct CallableInfo {
 // Map effects to single diagnostics.
 class EffectToDiagnosticMap {
   // Since we currently only have a tiny number of effects (typically no more
-  // than 1), use a sorted SmallVector.
+  // than 1), use a sorted SmallVector with an inline capacity of 1. Since it
+  // is often empty, use a unique_ptr to the SmallVector.
   using Element = std::pair<const FunctionEffect *, Diagnostic>;
-  using ImplVec = llvm::SmallVector<Element>;
+  using ImplVec = llvm::SmallVector<Element, 1>;
   std::unique_ptr<ImplVec> Impl;
 
 public:
@@ -2533,7 +2534,7 @@ class EffectToDiagnosticMap {
       return Item.second;
     }
     Element Elem(Key, {});
-    auto Iter = _find(Elem);
+    auto *Iter = _find(Elem);
     if (Iter != Impl->end() && Iter->first == Key) {
       return Iter->second;
     }
@@ -2546,7 +2547,7 @@ class EffectToDiagnosticMap {
       return nullptr;
     }
     Element elem(key, {});
-    auto iter = _find(elem);
+    auto *iter = _find(elem);
     if (iter != Impl->end() && iter->first == key) {
       return &iter->second;
     }
@@ -2599,7 +2600,7 @@ class PendingFunctionAnalysis {
                           FunctionEffectSet AllInferrableEffectsToVerify) {
     MutableFunctionEffectSet fx;
     for (const auto *effect : cinfo.Effects) {
-      if (effect->flags() & FunctionEffect::kRequiresVerification) {
+      if (effect->flags() & FunctionEffect::FE_RequiresVerification) {
         fx.insert(effect);
       }
     }
@@ -2807,7 +2808,7 @@ class Analyzer {
       MutableFunctionEffectSet inferrableEffects;
       for (const FunctionEffect *effect : Sem.AllEffectsToVerify) {
         const auto Flags = effect->flags();
-        if (Flags & FunctionEffect::kInferrableOnCallees) {
+        if (Flags & FunctionEffect::FE_InferrableOnCallees) {
           inferrableEffects.insert(effect);
         }
       }
@@ -2820,7 +2821,7 @@ class Analyzer {
 
     SmallVector<const Decl *> &verifyQueue = Sem.DeclsWithUnverifiedEffects;
 
-    // It's useful to use DeclsWithUnverifiedEffects as a stack for a
+    // It's helpful to use DeclsWithUnverifiedEffects as a stack for a
     // depth-first traversal rather than have a secondary container. But first,
     // reverse it, so Decls are verified in the order they are declared.
     std::reverse(verifyQueue.begin(), verifyQueue.end());
@@ -2840,7 +2841,7 @@ class Analyzer {
           verifyQueue.pop_back();
           continue;
         }
-        llvm_unreachable("shouldn't happen");
+        llvm_unreachable("unexpected DeclAnalysis item");
       }
 
       auto *Pending = verifyDecl(D);
@@ -2861,9 +2862,10 @@ class Analyzer {
         }
         if (isa<PendingFunctionAnalysis *>(AP)) {
           // $$$$$$$$$$$$$$$$$$$$$$$ recursion $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
+          // TODO
           __builtin_trap();
         }
-        llvm_unreachable("shouldn't happen");
+        llvm_unreachable("unexpected DeclAnalysis item");
       }
     }
   }
@@ -2964,7 +2966,7 @@ class Analyzer {
 
     auto check1Effect = [&](const FunctionEffect *Effect, bool Inferring) {
       const auto Flags = Effect->flags();
-      if (Flags & FunctionEffect::kVerifyCalls) {
+      if (Flags & FunctionEffect::FE_VerifyCalls) {
         const bool diagnose = Effect->diagnoseFunctionCall(
             DirectCall, Caller.CDecl, Caller.Effects, Callee.CDecl,
             CalleeEffects);
@@ -2972,7 +2974,7 @@ class Analyzer {
           // If inference is not allowed, or the target is indirect (virtual
           // method/function ptr?), generate a diagnostic now.
           if (!IsInferencePossible ||
-              !(Flags & FunctionEffect::kInferrableOnCallees)) {
+              !(Flags & FunctionEffect::FE_InferrableOnCallees)) {
             if (Callee.FuncType == SpecialFuncType::None) {
               PFA.checkAddDiagnostic(Inferring,
                                      {Effect, DiagnosticID::CallsUnsafeDecl,
@@ -3263,7 +3265,7 @@ class Analyzer {
           CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
 
       auto check1Effect = [&](const FunctionEffect *effect, bool inferring) {
-        if (effect->flags() & FunctionEffect::kVerifyCalls) {
+        if (effect->flags() & FunctionEffect::FE_VerifyCalls) {
           if (FPT == nullptr ||
               effect->diagnoseFunctionCall(
                   /*direct=*/false, CurrentCaller.CDecl, CurrentCaller.Effects,
@@ -3333,19 +3335,19 @@ class Analyzer {
     bool shouldWalkTypesOfTypeLocs() const { return false; }
 
     bool VisitCXXThrowExpr(CXXThrowExpr *Throw) {
-      diagnoseLanguageConstruct(FunctionEffect::kExcludeThrow,
+      diagnoseLanguageConstruct(FunctionEffect::FE_ExcludeThrow,
                                 DiagnosticID::Throws, Throw->getThrowLoc());
       return Proceed;
     }
 
     bool VisitCXXCatchStmt(CXXCatchStmt *Catch) {
-      diagnoseLanguageConstruct(FunctionEffect::kExcludeCatch,
+      diagnoseLanguageConstruct(FunctionEffect::FE_ExcludeCatch,
                                 DiagnosticID::Catches, Catch->getCatchLoc());
       return Proceed;
     }
 
     bool VisitObjCMessageExpr(ObjCMessageExpr *Msg) {
-      diagnoseLanguageConstruct(FunctionEffect::kExcludeObjCMessageSend,
+      diagnoseLanguageConstruct(FunctionEffect::FE_ExcludeObjCMessageSend,
                                 DiagnosticID::CallsObjC, Msg->getBeginLoc());
       return Proceed;
     }
@@ -3392,7 +3394,7 @@ class Analyzer {
       }
 
       if (Var->isStaticLocal()) {
-        diagnoseLanguageConstruct(FunctionEffect::kExcludeStaticLocalVars,
+        diagnoseLanguageConstruct(FunctionEffect::FE_ExcludeStaticLocalVars,
                                   DiagnosticID::HasStaticLocal,
                                   Var->getLocation());
       }
@@ -3491,8 +3493,8 @@ class Analyzer {
         const auto TLSK = Var->getTLSKind();
         if (TLSK != VarDecl::TLS_None) {
           // At least on macOS, thread-local variables are initialized on
-          // first access.
-          diagnoseLanguageConstruct(FunctionEffect::kExcludeThreadLocalVars,
+          // first access, including a heap allocation.
+          diagnoseLanguageConstruct(FunctionEffect::FE_ExcludeThreadLocalVars,
                                     DiagnosticID::AccessesThreadLocal,
                                     E->getLocation());
         }
@@ -3503,14 +3505,6 @@ class Analyzer {
     // Unevaluated contexts: need to skip
     // see https://reviews.llvm.org/rG777eb4bcfc3265359edb7c979d3e5ac699ad4641
 
-    // bool TraverseTypeLoc(TypeLoc /*unused*/)
-    // {
-    //   // This is a big blunt hammer so that we don't reach __invoke()'s call
-    //   to declval().
-    //   // Is it correct?
-    //   return Proceed;
-    // }
-
     bool TraverseGenericSelectionExpr(GenericSelectionExpr *Node) {
       return TraverseStmt(Node->getResultExpr());
     }
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index d407018adfde60..c9488431d43436 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11155,17 +11155,21 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
   if (hasUncompilableErrorOccurred())
     return;
 
+#if 0
+// TODO: Does anything break if we don't do this?
+
   // For code in dependent contexts, we'll do this at instantiation time
   // (??? This was copied from something else in AnalysisBasedWarnings ???)
   if (cast<DeclContext>(D)->isDependentContext()) {
     return;
   }
+#endif
 
   // Filter out declarations that the FunctionEffect analysis should skip
-  // and not verify. (??? Is this the optimal order in which to test ???)
+  // and not verify.
   bool FXNeedVerification = false;
   for (const auto *Effect : FX) {
-    if (Effect->flags() & FunctionEffect::kRequiresVerification) {
+    if (Effect->flags() & FunctionEffect::FE_RequiresVerification) {
       AllEffectsToVerify.insert(Effect);
       FXNeedVerification = true;
     }
@@ -15990,7 +15994,6 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
       getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation)
     Diag(FD->getLocation(), diag::warn_function_def_in_objc_container);
 
-  // TODO: does this really need to be getCanonicalDecl()?
   if (const auto FX = FD->getCanonicalDecl()->getFunctionEffects()) {
     CheckAddCallableWithEffects(FD, FX);
   }
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index c4f87be129fdca..a7849f42d38c13 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -172,6 +172,8 @@ static void diagnoseBadTypeAttribute(Sema &S, const ParsedAttr &attr,
   case ParsedAttr::AT_TypeNullableResult:                                      \
   case ParsedAttr::AT_TypeNullUnspecified
 
+enum class BoolAttrState : uint8_t { Unseen, False, True };
+
 namespace {
   /// An object which stores processing state for the entire
   /// GetTypeForDeclarator process.
@@ -215,14 +217,15 @@ namespace {
     // Manual logic for finding previous attributes would be more complex,
     // unless we transformed nolock/noalloc(false) into distinct separate
     // attributes from the ones which are parsed.
-    unsigned char parsedNolock : 2;
-    unsigned char parsedNoalloc : 2;
+    BoolAttrState parsedNolock : 2;
+    BoolAttrState parsedNoalloc : 2;
 
   public:
     TypeProcessingState(Sema &sema, Declarator &declarator)
         : sema(sema), declarator(declarator),
           chunkIndex(declarator.getNumTypeObjects()), parsedNoDeref(false),
-          parsedNolock(0), parsedNoalloc(0) {}
+          parsedNolock(BoolAttrState::Unseen),
+          parsedNoalloc(BoolAttrState::Unseen) {}
 
     Sema &getSema() const {
       return sema;
@@ -349,10 +352,10 @@ namespace {
 
     bool didParseNoDeref() const { return parsedNoDeref; }
 
-    void setParsedNolock(unsigned char v) { parsedNolock = v; }
-    unsigned char getParsedNolock() const { return parsedNolock; }
-    void setParsedNoalloc(unsigned char v) { parsedNoalloc = v; }
-    unsigned char getParsedNoalloc() const { return parsedNoalloc; }
+    void setParsedNolock(BoolAttrState v) { parsedNolock = v; }
+    BoolAttrState getParsedNolock() const { return parsedNolock; }
+    void setParsedNoalloc(BoolAttrState v) { parsedNoalloc = v; }
+    BoolAttrState getParsedNoalloc() const { return parsedNoalloc; }
 
     ~TypeProcessingState() {
       if (savedAttrs.empty())
@@ -7944,16 +7947,13 @@ static Attr *getCCTypeAttr(ASTContext &Ctx, ParsedAttr &Attr) {
 static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
                                         ParsedAttr &PAttr, QualType &type,
                                         FunctionTypeUnwrapper &unwrapped) {
-  // Values of nolockState / noallocState
-  enum { kNotSeen = 0, kSeenFalse = 1, kSeenTrue = 2 };
-
-  const bool isNoLock = PAttr.getKind() == ParsedAttr::AT_NoLock;
-  Sema &S = state.getSema();
-
   // Delay if this is not a function type.
   if (!unwrapped.isFunctionType())
     return false;
 
+  const bool isNoLock = PAttr.getKind() == ParsedAttr::AT_NoLock;
+  Sema &S = state.getSema();
+
   // Require FunctionProtoType
   auto *FPT = unwrapped.get()->getAs<FunctionProtoType>();
   if (FPT == nullptr) {
@@ -7962,6 +7962,8 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
   }
 
   // Parse the conditional expression, if any
+  // TODO: There's a better way to do this. See PR feedback.
+  // TODO: Handle a type-dependent expression.
   bool Cond = true; // default
   if (PAttr.getNumArgs() > 0) {
     if (!S.checkBoolExprArgumentAttr(PAttr, 0, Cond)) {
@@ -7983,14 +7985,16 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
   };
 
   // check nolock(true) against nolock(false), and same for noalloc
-  const unsigned newState = Cond ? kSeenTrue : kSeenFalse;
-  const unsigned oppositeNewState = Cond ? kSeenFalse : kSeenTrue;
+  const BoolAttrState newState =
+      Cond ? BoolAttrState::True : BoolAttrState::False;
+  const BoolAttrState oppositeNewState =
+      Cond ? BoolAttrState::False : BoolAttrState::True;
   if (isNoLock) {
     if (state.getParsedNolock() == oppositeNewState) {
       return incompatible("nolock(true)", "nolock(false)");
     }
     // also check nolock(true) against noalloc(false)
-    if (Cond && state.getParsedNoalloc() == kSeenFalse) {
+    if (Cond && state.getParsedNoalloc() == BoolAttrState::False) {
       return incompatible("nolock(true)", "noalloc(false)");
     }
     state.setParsedNolock(newState);
@@ -7999,7 +8003,7 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
       return incompatible("noalloc(true)", "noalloc(false)");
     }
     // also check nolock(true) against noalloc(false)
-    if (state.getParsedNolock() == kSeenTrue) {
+    if (state.getParsedNolock() == BoolAttrState::True) {
       if (!Cond) {
         return incompatible("nolock(true)", "noalloc(false)");
       }
@@ -8022,6 +8026,8 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
     return true;
   }
 
+  // nolock(true) and noalloc(true) are represented as FunctionEffects, in a
+  // FunctionEffectSet attached to a FunctionProtoType.
   const FunctionEffect *Effect = nullptr;
   if (isNoLock) {
     Effect = &NoLockNoAllocEffect::nolock_instance();
@@ -8031,9 +8037,9 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
 
   MutableFunctionEffectSet newEffectSet{Effect};
   if (EPI.FunctionEffects) {
-    // Preserve all previous effects - except noalloc, when we are adding nolock
+    // Preserve any previous effects - except noalloc, when we are adding nolock
     for (const auto *effect : EPI.FunctionEffects) {
-      if (!(isNoLock && effect->type() == FunctionEffect::kNoAllocTrue))
+      if (!(isNoLock && effect->type() == FunctionEffect::Type::NoAllocTrue))
         newEffectSet.insert(effect);
     }
   }
diff --git a/clang/test/Sema/attr-nolock3.cpp b/clang/test/Sema/attr-nolock-constraints.cpp
similarity index 96%
rename from clang/test/Sema/attr-nolock3.cpp
rename to clang/test/Sema/attr-nolock-constraints.cpp
index 65d610f796f87f..801f971b410865 100644
--- a/clang/test/Sema/attr-nolock3.cpp
+++ b/clang/test/Sema/attr-nolock-constraints.cpp
@@ -1,4 +1,6 @@
 // RUN: %clang_cc1 -fsyntax-only -fblocks -fcxx-exceptions -verify %s
+// These are in a separate file because errors (e.g. incompatible attributes) currently prevent
+// the AnalysisBasedWarnings pass from running at all.
 
 #if !__has_attribute(clang_nolock)
 #error "the 'nolock' attribute is not available"
diff --git a/clang/test/Sema/attr-nolock.cpp b/clang/test/Sema/attr-nolock-parsing.cpp
similarity index 67%
rename from clang/test/Sema/attr-nolock.cpp
rename to clang/test/Sema/attr-nolock-parsing.cpp
index 3f9938a2e54601..6fac57645a1ae2 100644
--- a/clang/test/Sema/attr-nolock.cpp
+++ b/clang/test/Sema/attr-nolock-parsing.cpp
@@ -1,36 +1,34 @@
 // RUN: %clang_cc1 %s -ast-dump -fblocks | FileCheck %s
-// expected-no-diagnostics
 
 // Make sure that the attribute gets parsed and attached to the correct AST elements.
-// Update 1 Mar 2024
 
 #pragma clang diagnostic ignored "-Wunused-variable"
 
 // =========================================================================================
 // Square brackets, true
 
-#define NOLOCK [[clang::nolock]]
+namespace square_brackets {
 
 // On the type of the FunctionDecl
-void nl_function() NOLOCK;
+void nl_function() [[clang::nolock]];
 // CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nolock))'
 
 // On the type of the VarDecl holding a function pointer
-void (*nl_func_a)() NOLOCK;
+void (*nl_func_a)() [[clang::nolock]];
 // CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nolock))'
 
 // Check alternate attribute type and placement
-__attribute__((clang_nolock)) void (*nl_func_b)(void);
+__attribute__((clang_nolock)) void (*nl_func_b)();
 // CHECK: VarDecl {{.*}} nl_func_b 'void (*)() __attribute__((clang_nolock))'
 
 // On the type of the ParmVarDecl of a function parameter
-static void nlReceiver(void (*nl_func)() NOLOCK);
+static void nlReceiver(void (*nl_func)() [[clang::nolock]]);
 // CHECK: ParmVarDecl {{.*}} nl_func 'void (*)() __attribute__((clang_nolock))'
 
 // As an AttributedType within the nested types of a typedef
-typedef void (*nl_fp_type)() NOLOCK;
+typedef void (*nl_fp_type)() [[clang::nolock]];
 // CHECK: TypedefDecl {{.*}} nl_fp_type 'void (*)() __attribute__((clang_nolock))'
-using nl_fp_talias = void (*)() NOLOCK;
+using nl_fp_talias = void (*)() [[clang::nolock]];
 // CHECK: TypeAliasDecl {{.*}} nl_fp_talias 'void (*)() __attribute__((clang_nolock))'
 
 // From a typedef or typealias, on a VarDecl
@@ -41,7 +39,7 @@ nl_fp_talias nl_fp_var2;
 
 // On type of a FieldDecl
 struct Struct {
-	void (*nl_func_field)() NOLOCK;
+	void (*nl_func_field)() [[clang::nolock]];
 // CHECK: FieldDecl {{.*}} nl_func_field 'void (*)() __attribute__((clang_nolock))'
 };
 
@@ -55,10 +53,10 @@ void nl2() [[clang::noalloc]] [[clang::nolock]];
 // --- Blocks ---
 
 // On the type of the VarDecl holding a BlockDecl
-void (^nl_block1)() NOLOCK = ^() NOLOCK {};
+void (^nl_block1)() [[clang::nolock]] = ^() [[clang::nolock]] {};
 // CHECK: VarDecl {{.*}} nl_block1 'void (^)() __attribute__((clang_nolock))'
 
-int (^nl_block2)() NOLOCK = ^() NOLOCK { return 0; };
+int (^nl_block2)() [[clang::nolock]] = ^() [[clang::nolock]] { return 0; };
 // CHECK: VarDecl {{.*}} nl_block2 'int (^)() __attribute__((clang_nolock))'
 
 // The operand of the CallExpr is an ImplicitCastExpr of a DeclRefExpr -> nl_block which hold the attribute
@@ -66,7 +64,7 @@ static void blockCaller() { nl_block1(); }
 // CHECK: DeclRefExpr {{.*}} 'nl_block1' 'void (^)() __attribute__((clang_nolock))'
 
 // $$$ TODO: There are still some loose ends in all the methods of the lambda
-auto nl_lambda = []() NOLOCK {};
+auto nl_lambda = []() [[clang::nolock]] {};
 
 // =========================================================================================
 // Square brackets, false
@@ -74,5 +72,28 @@ auto nl_lambda = []() NOLOCK {};
 void nl_func_false() [[clang::nolock(false)]];
 // CHECK: FunctionDecl {{.*}} nl_func_false 'void () __attribute__((clang_nolock(false)))'
 
+} // namespace square_brackets
+
+// =========================================================================================
+// GNU-style attribute, true
+
+namespace gnu_style {
+
+// On the type of the FunctionDecl
+void nl_function() __attribute__((clang_nolock));
+// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nolock))'
+
+// Alternate placement on the FunctionDecl
+__attribute__((clang_nolock)) void nl_function();
+// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nolock))'
+
+// On the type of the VarDecl holding a function pointer
+void (*nl_func_a)() __attribute__((clang_nolock));
+// CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nolock))'
+
+
+
+} // namespace gnu_style
+
 // TODO: Duplicate the above for noalloc
 // TODO: Duplicate the above for GNU-style attribute?
diff --git a/clang/test/Sema/attr-nolock-sema.cpp b/clang/test/Sema/attr-nolock-sema.cpp
new file mode 100644
index 00000000000000..68b056bec1bdfd
--- /dev/null
+++ b/clang/test/Sema/attr-nolock-sema.cpp
@@ -0,0 +1,89 @@
+// RUN: %clang_cc1 -fsyntax-only -fblocks -fcxx-exceptions -verify %s
+// R UN: %clang_cc1 -fsyntax-only -fblocks -verify -x c -std=c23 %s
+
+// TODO: There's a problem with diagnosing type conversions in plain C.
+
+#if !__has_attribute(clang_nolock)
+#error "the 'nolock' attribute is not available"
+#endif
+
+// --- ATTRIBUTE SYNTAX: SUBJECTS ---
+
+int nl_var [[clang::nolock]]; // expected-warning {{'nolock' only applies to function types; type here is 'int'}}
+struct nl_struct {} [[clang::nolock]]; // expected-warning {{attribute 'nolock' is ignored, place it after "struct" to apply attribute to type declaration}}
+struct [[clang::nolock]] nl_struct2 {}; // expected-error {{'nolock' attribute cannot be applied to a declaration}}
+
+// --- ATTRIBUTE SYNTAX: COMBINATIONS ---
+// Check invalid combinations of nolock/noalloc attributes
+
+void nl_true_false_1() [[clang::nolock(true)]] [[clang::nolock(false)]]; // expected-error {{nolock(true) and nolock(false) attributes are not compatible}}
+void nl_true_false_2() [[clang::nolock(false)]] [[clang::nolock(true)]]; // expected-error {{nolock(true) and nolock(false) attributes are not compatible}}
+
+void na_true_false_1() [[clang::noalloc(true)]] [[clang::noalloc(false)]]; // expected-error {{noalloc(true) and noalloc(false) attributes are not compatible}}
+void na_true_false_2() [[clang::noalloc(false)]] [[clang::noalloc(true)]]; // expected-error {{noalloc(true) and noalloc(false) attributes are not compatible}}
+
+void nl_true_na_true_1() [[clang::nolock]] [[clang::noalloc]];
+void nl_true_na_true_2() [[clang::noalloc]] [[clang::nolock]];
+
+void nl_true_na_false_1() [[clang::nolock]] [[clang::noalloc(false)]]; // expected-error {{nolock(true) and noalloc(false) attributes are not compatible}}
+void nl_true_na_false_2() [[clang::noalloc(false)]] [[clang::nolock]]; // expected-error {{nolock(true) and noalloc(false) attributes are not compatible}}
+
+void nl_false_na_true_1() [[clang::nolock(false)]] [[clang::noalloc]];
+void nl_false_na_true_2() [[clang::noalloc]] [[clang::nolock(false)]];
+
+void nl_false_na_false_1() [[clang::nolock(false)]] [[clang::noalloc(false)]];
+void nl_false_na_false_2() [[clang::noalloc(false)]] [[clang::nolock(false)]];
+
+// --- TYPE CONVERSIONS ---
+
+void unannotated();
+void nolock() [[clang::nolock]];
+void noalloc() [[clang::noalloc]];
+void type_conversions()
+{
+	// It's fine to remove a performance constraint.
+	void (*fp_plain)();
+
+	fp_plain = unannotated;
+	fp_plain = nolock;
+	fp_plain = noalloc;
+
+	// Adding/spoofing nolock is unsafe.
+	void (*fp_nolock)() [[clang::nolock]];
+	fp_nolock = nolock;
+	fp_nolock = unannotated; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
+	fp_nolock = noalloc; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
+
+	// Adding/spoofing noalloc is unsafe.
+	void (*fp_noalloc)() [[clang::noalloc]];
+	fp_noalloc = noalloc;
+	fp_noalloc = nolock; // no warning because nolock includes noalloc fp_noalloc = unannotated;
+	fp_noalloc = unannotated; // expected-warning {{attribute 'noalloc' should not be added via type conversion}}
+}
+
+// --- VIRTUAL METHODS ---
+#ifdef __cplusplus
+struct Base {
+	virtual void f1();
+	virtual void nolock() noexcept [[clang::nolock]]; // expected-note {{overridden virtual function is here}}
+	virtual void noalloc() noexcept [[clang::noalloc]]; // expected-note {{overridden virtual function is here}}
+};
+
+struct Derived : public Base {
+	void f1() [[clang::nolock]] override;
+	void nolock() noexcept override; // expected-warning {{attribute 'nolock' on overriding function does not match base version}}
+	void noalloc() noexcept override; // expected-warning {{attribute 'noalloc' on overriding function does not match base version}}
+};
+#endif // __cplusplus
+
+// --- REDECLARATIONS ---
+
+int f2();
+// redeclaration with a stronger constraint is OK.
+int f2() [[clang::nolock]]; // expected-note {{previous declaration is here}}
+int f2() { return 42; } // expected-warning {{attribute 'nolock' on function does not match previous declaration}}
+
+int f3();
+// redeclaration with a stronger constraint is OK.
+int f3() [[clang::noalloc]]; // expected-note {{previous declaration is here}}
+int f3() { return 42; } // expected-warning {{attribute 'noalloc' on function does not match previous declaration}}
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
index c30d0f42e37aee..4afd9ed10582ad 100644
--- a/clang/test/Sema/attr-nolock-wip.cpp
+++ b/clang/test/Sema/attr-nolock-wip.cpp
@@ -5,20 +5,20 @@
 #error "the 'nolock' attribute is not available"
 #endif
 
-void unannotated(void);
-void nolock(void) [[clang::nolock]];
-void noalloc(void) [[clang::noalloc]];
+void unannotated();
+void nolock() [[clang::nolock]];
+void noalloc() [[clang::noalloc]];
 
 
-void callthis(void (*fp)(void));
+void callthis(void (*fp)());
 
 
-void type_conversions(void)
+void type_conversions()
 {
 // 	callthis(nolock);
 
 	// It's fine to remove a performance constraint.
-	void (*fp_plain)(void);
+	void (*fp_plain)();
 
 // 	fp_plain = unannotated;
 	fp_plain = nolock;
diff --git a/clang/test/Sema/attr-nolock2.cpp b/clang/test/Sema/attr-nolock2.cpp
deleted file mode 100644
index d2a35453b08bb7..00000000000000
--- a/clang/test/Sema/attr-nolock2.cpp
+++ /dev/null
@@ -1,84 +0,0 @@
-// RUN: %clang_cc1 -fsyntax-only -fblocks -verify %s
-// R UN: %clang_cc1 -fsyntax-only -fblocks -verify -x c -std=c2x %s
-
-// TODO: There's a problem with diagnosing type conversions in plain C.
-
-#pragma clang diagnostic error "-Wstrict-prototypes"
-
-#if !__has_attribute(clang_nolock)
-#error "the 'nolock' attribute is not available"
-#endif
-
-// --- ATTRIBUTE SYNTAX: COMBINATIONS ---
-// Check invalid combinations of nolock/noalloc attributes
-void nl_true_false_1(void) [[clang::nolock(true)]] [[clang::nolock(false)]]; // expected-error {{nolock(true) and nolock(false) attributes are not compatible}}
-void nl_true_false_2(void) [[clang::nolock(false)]] [[clang::nolock(true)]]; // expected-error {{nolock(true) and nolock(false) attributes are not compatible}}
-
-void na_true_false_1(void) [[clang::noalloc(true)]] [[clang::noalloc(false)]]; // expected-error {{noalloc(true) and noalloc(false) attributes are not compatible}}
-void na_true_false_2(void) [[clang::noalloc(false)]] [[clang::noalloc(true)]]; // expected-error {{noalloc(true) and noalloc(false) attributes are not compatible}}
-
-void nl_true_na_true_1(void) [[clang::nolock]] [[clang::noalloc]];
-void nl_true_na_true_2(void) [[clang::noalloc]] [[clang::nolock]];
-
-void nl_true_na_false_1(void) [[clang::nolock]] [[clang::noalloc(false)]]; // expected-error {{nolock(true) and noalloc(false) attributes are not compatible}}
-void nl_true_na_false_2(void) [[clang::noalloc(false)]] [[clang::nolock]]; // expected-error {{nolock(true) and noalloc(false) attributes are not compatible}}
-
-void nl_false_na_true_1(void) [[clang::nolock(false)]] [[clang::noalloc]];
-void nl_false_na_true_2(void) [[clang::noalloc]] [[clang::nolock(false)]];
-
-void nl_false_na_false_1(void) [[clang::nolock(false)]] [[clang::noalloc(false)]];
-void nl_false_na_false_2(void) [[clang::noalloc(false)]] [[clang::nolock(false)]];
-
-// --- TYPE CONVERSIONS ---
-
-void unannotated(void);
-void nolock(void) [[clang::nolock]];
-void noalloc(void) [[clang::noalloc]];
-void type_conversions(void)
-{
-	// It's fine to remove a performance constraint.
-	void (*fp_plain)(void);
-
-	fp_plain = unannotated;
-	fp_plain = nolock;
-	fp_plain = noalloc;
-
-	// Adding/spoofing nolock is unsafe.
-	void (*fp_nolock)(void) [[clang::nolock]];
-	fp_nolock = nolock;
-	fp_nolock = unannotated; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
-	fp_nolock = noalloc; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
-
-	// Adding/spoofing noalloc is unsafe.
-	void (*fp_noalloc)(void) [[clang::noalloc]];
-	fp_noalloc = noalloc;
-	fp_noalloc = nolock; // no warning because nolock includes noalloc fp_noalloc = unannotated;
-	fp_noalloc = unannotated; // expected-warning {{attribute 'noalloc' should not be added via type conversion}}
-}
-
-// --- VIRTUAL METHODS ---
-#ifdef __cplusplus
-struct Base {
-	virtual void f1();
-	virtual void nolock() noexcept [[clang::nolock]]; // expected-note {{overridden virtual function is here}}
-	virtual void noalloc() noexcept [[clang::noalloc]]; // expected-note {{overridden virtual function is here}}
-};
-
-struct Derived : public Base {
-	void f1() [[clang::nolock]] override;
-	void nolock() noexcept override; // expected-warning {{attribute 'nolock' on overriding function does not match base version}}
-	void noalloc() noexcept override; // expected-warning {{attribute 'noalloc' on overriding function does not match base version}}
-};
-#endif // __cplusplus
-
-// --- REDECLARATIONS ---
-
-int f2(void);
-// redeclaration with a stronger constraint is OK.
-int f2(void) [[clang::nolock]]; // expected-note {{previous declaration is here}}
-int f2(void) { return 42; } // expected-warning {{attribute 'nolock' on function does not match previous declaration}}
-
-int f3(void);
-// redeclaration with a stronger constraint is OK.
-int f3(void) [[clang::noalloc]]; // expected-note {{previous declaration is here}}
-int f3(void) { return 42; } // expected-warning {{attribute 'noalloc' on function does not match previous declaration}}

>From 4c6486ff1281471eea66811fa2b6aa941373c879 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <doug at sonosphere.com>
Date: Thu, 14 Mar 2024 07:14:32 -0700
Subject: [PATCH 06/40] Update clang/include/clang/AST/Type.h

Co-authored-by: Shafik Yaghmour <shafik.yaghmour at intel.com>
---
 clang/include/clang/AST/Type.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 63b78d75089f9e..79738729ee3f39 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4235,7 +4235,7 @@ class FunctionEffectSet {
 
 public:
   using Differences =
-      SmallVector<std::pair<const FunctionEffect *, bool /*added*/>>;
+      SmallVector<std::pair<const FunctionEffect *, /*added=*/bool>>;
 
   FunctionEffectSet() : Impl(nullptr) {}
 

>From e6b1e3557db00bd09ae3b4d2791ae06b3f870719 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 13 Mar 2024 15:47:06 -0700
Subject: [PATCH 07/40] - Sema::CheckAddCallableWithEffects: really do skip
 functions in dependent contexts. - Tweaking tests - things that came up in
 review.

---
 clang/lib/Sema/SemaDecl.cpp                   |  7 +--
 ...ock-parsing.cpp => attr-nolock-syntax.cpp} | 15 +++++-
 clang/test/Sema/attr-nolock-wip.cpp           | 52 +++++++++++++++++++
 3 files changed, 67 insertions(+), 7 deletions(-)
 rename clang/test/Sema/{attr-nolock-parsing.cpp => attr-nolock-syntax.cpp} (88%)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index c9488431d43436..d860804102dfc9 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11155,15 +11155,12 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
   if (hasUncompilableErrorOccurred())
     return;
 
-#if 0
-// TODO: Does anything break if we don't do this?
-
   // For code in dependent contexts, we'll do this at instantiation time
-  // (??? This was copied from something else in AnalysisBasedWarnings ???)
+  // Without this check, we would analyze the function based on placeholder
+  // template parameters, and potentially generate spurious diagnostics.
   if (cast<DeclContext>(D)->isDependentContext()) {
     return;
   }
-#endif
 
   // Filter out declarations that the FunctionEffect analysis should skip
   // and not verify.
diff --git a/clang/test/Sema/attr-nolock-parsing.cpp b/clang/test/Sema/attr-nolock-syntax.cpp
similarity index 88%
rename from clang/test/Sema/attr-nolock-parsing.cpp
rename to clang/test/Sema/attr-nolock-syntax.cpp
index 6fac57645a1ae2..2c0d71ba93ddf0 100644
--- a/clang/test/Sema/attr-nolock-parsing.cpp
+++ b/clang/test/Sema/attr-nolock-syntax.cpp
@@ -50,6 +50,9 @@ void nl1() [[clang::nolock]] [[clang::noalloc]];
 void nl2() [[clang::noalloc]] [[clang::nolock]];
 // CHECK: FunctionDecl {{.*}} nl2 'void () __attribute__((clang_nolock))'
 
+decltype(nl1) nl3;
+// CHECK: FunctionDecl {{.*}} nl3 'decltype(nl1)':'void () __attribute__((clang_nolock))'
+
 // --- Blocks ---
 
 // On the type of the VarDecl holding a BlockDecl
@@ -63,8 +66,11 @@ int (^nl_block2)() [[clang::nolock]] = ^() [[clang::nolock]] { return 0; };
 static void blockCaller() { nl_block1(); }
 // CHECK: DeclRefExpr {{.*}} 'nl_block1' 'void (^)() __attribute__((clang_nolock))'
 
-// $$$ TODO: There are still some loose ends in all the methods of the lambda
+// --- Lambdas ---
+
+// On the operator() of a lambda's CXXMethodDecl
 auto nl_lambda = []() [[clang::nolock]] {};
+// CHECK: CXXMethodDecl {{.*}} operator() 'void () const __attribute__((clang_nolock))' inline
 
 // =========================================================================================
 // Square brackets, false
@@ -72,11 +78,17 @@ auto nl_lambda = []() [[clang::nolock]] {};
 void nl_func_false() [[clang::nolock(false)]];
 // CHECK: FunctionDecl {{.*}} nl_func_false 'void () __attribute__((clang_nolock(false)))'
 
+// TODO: This exposes a bug where a type attribute is lost when inferring a lambda's
+// return type.
+auto nl_lambda_false = []() [[clang::nolock(false)]] {};
+
 } // namespace square_brackets
 
 // =========================================================================================
 // GNU-style attribute, true
 
+// TODO: Duplicate more of the above for GNU-style attribute
+
 namespace gnu_style {
 
 // On the type of the FunctionDecl
@@ -96,4 +108,3 @@ void (*nl_func_a)() __attribute__((clang_nolock));
 } // namespace gnu_style
 
 // TODO: Duplicate the above for noalloc
-// TODO: Duplicate the above for GNU-style attribute?
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
index 4afd9ed10582ad..f73fbbec70f701 100644
--- a/clang/test/Sema/attr-nolock-wip.cpp
+++ b/clang/test/Sema/attr-nolock-wip.cpp
@@ -5,6 +5,9 @@
 #error "the 'nolock' attribute is not available"
 #endif
 
+// ============================================================================
+
+#if 0 // C function type problems
 void unannotated();
 void nolock() [[clang::nolock]];
 void noalloc() [[clang::noalloc]];
@@ -24,3 +27,52 @@ void type_conversions()
 	fp_plain = nolock;
 // 	fp_plain = noalloc;
 }
+#endif
+
+// ============================================================================
+
+#if 0
+// https://github.com/llvm/llvm-project/pull/84983#issuecomment-1994978033
+
+// the bug where AttributedType sugar gets lost on lambdas (when the "inferred" return type gets
+// converted to a concrete one) happens here and the nolock(false) attribute is lost from h.
+
+template <class T>
+void f(T a) [[clang::nolock]] { a(); }
+
+void m()
+{
+	auto g = []() [[clang::nolock]] {
+	};
+	
+	auto h = []() [[clang::nolock(false)]] {
+	};
+
+	f(g);
+	f(h);
+}
+#endif
+
+template <class _Tp, _Tp __v>
+struct integral_constant
+{
+  static constexpr const _Tp      value = __v;
+  typedef _Tp               value_type;
+  typedef integral_constant type;
+  constexpr operator value_type() const noexcept {return value;}
+  constexpr value_type operator ()() const noexcept {return value;}
+};
+
+template <class _Tp, _Tp __v>
+const _Tp integral_constant<_Tp, __v>::value;
+
+typedef integral_constant<bool, true>  true_type;
+typedef integral_constant<bool, false> false_type;
+
+template <typename T>
+struct is_nolock;
+
+
+
+void g() [[clang::nolock]];
+void h() [[clang::nolock(false)]];

>From fc67743117c637496728099a4cb89803d2c30ff3 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Fri, 15 Mar 2024 09:01:52 -0700
Subject: [PATCH 08/40] ASTContext::mergeFunctionTypes doesn't seem to need to
 do anything (?)

---
 clang/lib/AST/ASTContext.cpp | 35 ++++++-----------------------------
 1 file changed, 6 insertions(+), 29 deletions(-)

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 68f2ac3e1329f8..3e2142469babd5 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -10436,17 +10436,6 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
     allRTypes = false;
 
   FunctionType::ExtInfo einfo = lbaseInfo.withNoReturn(NoReturn);
-  FunctionEffectSet FromFX, ToFX;
-  std::optional<FunctionEffectSet> MergedFX;
-
-  if (lproto)
-    ToFX = lproto->getFunctionEffects();
-  if (rproto)
-    FromFX = rproto->getFunctionEffects();
-  if (ToFX != FromFX) {
-    // We want the intersection of the effects...
-    MergedFX = FunctionEffectSet::create(FromFX & ToFX);
-  }
 
   if (lproto && rproto) { // two C99 style function prototypes
     assert((AllowCXX ||
@@ -10463,6 +10452,8 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
     if (lproto->getMethodQuals() != rproto->getMethodQuals())
       return {};
 
+    // TODO: (nolock) Does anything need to be done with FunctionEffects?
+
     SmallVector<FunctionProtoType::ExtParameterInfo, 4> newParamInfos;
     bool canUseLeft, canUseRight;
     if (!mergeExtParameterInfo(lproto, rproto, canUseLeft, canUseRight,
@@ -10499,20 +10490,13 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
         allRTypes = false;
     }
 
-    if (!MergedFX) { // effects changed so we can't return either side unaltered
-      if (allLTypes)
-        return lhs;
-      if (allRTypes)
-        return rhs;
-    }
+    if (allLTypes) return lhs;
+    if (allRTypes) return rhs;
 
     FunctionProtoType::ExtProtoInfo EPI = lproto->getExtProtoInfo();
     EPI.ExtInfo = einfo;
     EPI.ExtParameterInfos =
         newParamInfos.empty() ? nullptr : newParamInfos.data();
-    if (MergedFX) {
-      EPI.FunctionEffects = *MergedFX;
-    }
     return getFunctionType(retType, types, EPI);
   }
 
@@ -10545,18 +10529,11 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
         return {};
     }
 
-    if (!MergedFX) { // effects changed so we can't return either side unaltered
-      if (allLTypes)
-        return lhs;
-      if (allRTypes)
-        return rhs;
-    }
+    if (allLTypes) return lhs;
+    if (allRTypes) return rhs;
 
     FunctionProtoType::ExtProtoInfo EPI = proto->getExtProtoInfo();
     EPI.ExtInfo = einfo;
-    if (MergedFX) {
-      EPI.FunctionEffects = *MergedFX;
-    }
     return getFunctionType(retType, proto->getParamTypes(), EPI);
   }
 

>From a63812551c65e588e5a15a86576da2a9ad179e7f Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Fri, 15 Mar 2024 09:07:20 -0700
Subject: [PATCH 09/40] Fix function pointer type conversion in C by making
 IsFunctionConversion() not change the type for C. Add comment about #85415.

---
 clang/lib/Sema/Sema.cpp              |  3 --
 clang/lib/Sema/SemaExpr.cpp          |  2 ++
 clang/lib/Sema/SemaOverload.cpp      | 45 +++++++++++-----------------
 clang/test/Sema/attr-nolock-sema.cpp |  4 +--
 clang/test/Sema/attr-nolock-wip.cpp  | 31 ++++++++++++-------
 5 files changed, 42 insertions(+), 43 deletions(-)

diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index b120ed22246961..8e96522542427a 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -588,8 +588,6 @@ void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
 // Generate diagnostics when adding or removing effects in a type conversion.
 void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
                                             SourceLocation Loc) {
-  llvm::outs() << "diagnoseFunctionEffectConversion: " << SrcType << " -> "
-               << DstType << "\n";
   const auto SrcFX = FunctionEffectSet::get(*SrcType);
   const auto DstFX = FunctionEffectSet::get(*DstType);
   if (SrcFX != DstFX) {
@@ -683,7 +681,6 @@ ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
   diagnoseZeroToNullptrConversion(Kind, E);
   if (!isCast(CCK) && !E->isNullPointerConstant(
                           Context, Expr::NPC_NeverValueDependent /* ???*/)) {
-    llvm::outs() << "Sema::ImpCastExprToType\n";
     diagnoseFunctionEffectConversion(Ty, E->getType(), E->getBeginLoc());
   }
 
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 643f8e7f444884..90932a532bebff 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -9986,6 +9986,8 @@ checkPointerTypesForAssignment(Sema &S, QualType LHSType, QualType RHSType,
       return Sema::IncompatibleFunctionPointer;
     return Sema::IncompatiblePointer;
   }
+  // #85415: This call to IsFunctionConversion appears to have inverted
+  // arguments: ltrans -> From, rtrans -> To
   if (!S.getLangOpts().CPlusPlus &&
       S.IsFunctionConversion(ltrans, rtrans, ltrans))
     return Sema::IncompatibleFunctionPointer;
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index e34aa7e970d5dc..0163969e9bf50d 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1787,9 +1787,6 @@ ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType,
 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
                                 QualType &ResultTy) {
 
-  llvm::outs() << "IsFunctionConversion: " << FromType << " -> " << ToType
-               << "\n";
-
   if (Context.hasSameUnqualifiedType(FromType, ToType))
     return false;
 
@@ -1828,7 +1825,6 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
     if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto)
       return false;
   }
-  llvm::outs() << "  didn't exit early\n";
 
   const auto *FromFn = cast<FunctionType>(CanFrom);
   FunctionType::ExtInfo FromEInfo = FromFn->getExtInfo();
@@ -1872,30 +1868,25 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
       Changed = true;
     }
 
-#if 1
-    // NOTE (TEMP): this works for C++ to allow dropping effects.
-    // For plain C, however, this creates an error when dropping effects!
-
-    // Transparently add/drop effects; here we are concerned with
-    // language rules/canonicalization. Adding/dropping effects is a warning.
-    auto FromFX = FromFPT->getFunctionEffects();
-    auto ToFX = ToFPT->getFunctionEffects();
-    if (FromFX != ToFX) {
-      llvm::outs() << "  effects change: " << FromType << " -> " << ToType
-                   << "\n";
-
-      // const auto MergedFX = FunctionEffectSet::getIntersection(FromFX, ToFX);
-      //  TODO: diagnose conflicts
-
-      FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
-      ExtInfo.FunctionEffects = ToFX;
-      QualType QT = Context.getFunctionType(FromFPT->getReturnType(),
-                                            FromFPT->getParamTypes(), ExtInfo);
-      FromFn = QT->getAs<FunctionType>();
-      llvm::outs() << "  produced " << QT << "\n";
-      Changed = true;
+    if (getLangOpts().CPlusPlus) {
+      // TODO:
+      // For C, when called from checkPointerTypesForAssignment,
+      // we need not to change the type, or else even an innocuous cast
+      // like dropping effects will fail.
+
+      // Transparently add/drop effects; here we are concerned with
+      // language rules/canonicalization. Adding/dropping effects is a warning.
+      const auto FromFX = FromFPT->getFunctionEffects();
+      const auto ToFX = ToFPT->getFunctionEffects();
+      if (FromFX != ToFX) {
+        FunctionProtoType::ExtProtoInfo ExtInfo = FromFPT->getExtProtoInfo();
+        ExtInfo.FunctionEffects = ToFX;
+        QualType QT = Context.getFunctionType(
+            FromFPT->getReturnType(), FromFPT->getParamTypes(), ExtInfo);
+        FromFn = QT->getAs<FunctionType>();
+        Changed = true;
+      }
     }
-#endif
   }
 
   if (!Changed)
diff --git a/clang/test/Sema/attr-nolock-sema.cpp b/clang/test/Sema/attr-nolock-sema.cpp
index 68b056bec1bdfd..99f6242e4747c9 100644
--- a/clang/test/Sema/attr-nolock-sema.cpp
+++ b/clang/test/Sema/attr-nolock-sema.cpp
@@ -1,7 +1,5 @@
 // RUN: %clang_cc1 -fsyntax-only -fblocks -fcxx-exceptions -verify %s
-// R UN: %clang_cc1 -fsyntax-only -fblocks -verify -x c -std=c23 %s
-
-// TODO: There's a problem with diagnosing type conversions in plain C.
+// RUN: %clang_cc1 -fsyntax-only -fblocks -verify -x c -std=c23 %s
 
 #if !__has_attribute(clang_nolock)
 #error "the 'nolock' attribute is not available"
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
index f73fbbec70f701..16ff464fb8aa08 100644
--- a/clang/test/Sema/attr-nolock-wip.cpp
+++ b/clang/test/Sema/attr-nolock-wip.cpp
@@ -7,25 +7,32 @@
 
 // ============================================================================
 
-#if 0 // C function type problems
+#if 1 // C function type problems
 void unannotated();
 void nolock() [[clang::nolock]];
 void noalloc() [[clang::noalloc]];
 
 
-void callthis(void (*fp)());
-
-
 void type_conversions()
 {
-// 	callthis(nolock);
-
 	// It's fine to remove a performance constraint.
 	void (*fp_plain)();
 
-// 	fp_plain = unannotated;
+	fp_plain = unannotated;
 	fp_plain = nolock;
-// 	fp_plain = noalloc;
+	fp_plain = noalloc;
+
+	// Adding/spoofing nolock is unsafe.
+	void (*fp_nolock)() [[clang::nolock]];
+	fp_nolock = nolock;
+	fp_nolock = unannotated; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
+	fp_nolock = noalloc; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
+
+	// Adding/spoofing noalloc is unsafe.
+	void (*fp_noalloc)() [[clang::noalloc]];
+	fp_noalloc = noalloc;
+	fp_noalloc = nolock; // no warning because nolock includes noalloc fp_noalloc = unannotated;
+	fp_noalloc = unannotated; // expected-warning {{attribute 'noalloc' should not be added via type conversion}}
 }
 #endif
 
@@ -53,6 +60,10 @@ void m()
 }
 #endif
 
+// ============================================================================
+
+#if 0
+// some messing around with type traits
 template <class _Tp, _Tp __v>
 struct integral_constant
 {
@@ -72,7 +83,7 @@ typedef integral_constant<bool, false> false_type;
 template <typename T>
 struct is_nolock;
 
-
-
 void g() [[clang::nolock]];
 void h() [[clang::nolock(false)]];
+#endif
+

>From c2ba529ffb574659ee13e6b95ee709fd53966916 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Sat, 16 Mar 2024 06:07:58 -0700
Subject: [PATCH 10/40] De-virtualize FunctionEffect; it's now a value type.
 Prepare for the uniquing table to be in ASTContext.

---
 clang/include/clang/AST/Type.h           | 372 ++++++++++-------------
 clang/lib/AST/Type.cpp                   | 306 +++++++++++--------
 clang/lib/AST/TypePrinter.cpp            |   4 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp |  87 +++---
 clang/lib/Sema/Sema.cpp                  |   6 +-
 clang/lib/Sema/SemaDecl.cpp              |  12 +-
 clang/lib/Sema/SemaDeclCXX.cpp           |   6 +-
 clang/lib/Sema/SemaType.cpp              |  19 +-
 8 files changed, 394 insertions(+), 418 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 79738729ee3f39..1d277d2ef06b19 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4185,117 +4185,198 @@ class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
   }
 };
 
-class FunctionEffect;
+// ------------------------------------------------------------------------------
+
+// TODO: Should FunctionEffect be located elsewhere, where Decl is not
+// forward-declared?
+class Decl;
+class CXXMethodDecl;
 class FunctionEffectSet;
 
+/// Represents an abstract function effect.
+class FunctionEffect {
+public:
+  enum class Type : unsigned char {
+    None = 0,
+    NoLockTrue,
+    NoAllocTrue,
+  };
+
+  /// Flags describing behaviors of the effect.
+  // (Why not a struct with bitfields? There's one function that would like to
+  // test a caller-specified bit. There are some potential optimizations that
+  // would OR together the bits of multiple effects.)
+  using Flags = unsigned;
+  enum FlagBit : unsigned {
+    // Some effects require verification, e.g. nolock(true); others might not?
+    // (no example yet; TODO: maybe always true, vestigial from nolock(false)).
+    FE_RequiresVerification = 0x1,
+
+    // Does this effect want to verify all function calls originating in
+    // functions having this effect? TODO: maybe always true, vestigial.
+    FE_VerifyCalls = 0x2,
+
+    // Can verification inspect callees' implementations? (e.g. nolock: yes,
+    // tcb+types: no)
+    FE_InferrableOnCallees = 0x4,
+
+    // Language constructs which effects can diagnose as disallowed.
+    FE_ExcludeThrow = 0x8,
+    FE_ExcludeCatch = 0x10,
+    FE_ExcludeObjCMessageSend = 0x20,
+    FE_ExcludeStaticLocalVars = 0x40,
+    FE_ExcludeThreadLocalVars = 0x80
+  };
+
+private:
+  // For uniqueness, currently only Type_ is significant.
+
+  Type Type_ : 2;   // Expands when there are more types
+  Flags Flags_ : 8; // A constant function of Type but cached here.
+
+  // Expansion: for hypothetical TCB+types, there could be one type for TCB,
+  // then ~16(?) bits "Subtype" to map to a specific named TCB. Subtype would
+  // be considered for uniqueness.
+  unsigned Unused : 22;
+
+public:
+  using CalleeDeclOrType =
+      llvm::PointerUnion<const Decl *, const FunctionProtoType *>;
+
+  FunctionEffect() : Type_(Type::None), Flags_(0), Unused(0) {}
+
+  explicit FunctionEffect(Type T);
+
+  /// The type of the effect.
+  Type type() const { return Type_; }
+
+  /// Flags describing behaviors of the effect.
+  Flags flags() const { return Flags_; }
+
+  /// The description printed in diagnostics, e.g. 'nolock'.
+  StringRef name() const;
+
+  /// A serializable, hashable representation.
+  uint32_t opaqueRepr() const { return unsigned(Type_) | (Flags_ << 2u); }
+
+  /// Return true if adding or removing the effect as part of a type conversion
+  /// should generate a diagnostic.
+  bool diagnoseConversion(bool Adding, QualType OldType,
+                          FunctionEffectSet OldFX, QualType NewType,
+                          FunctionEffectSet NewFX) const;
+
+  /// Return true if adding or removing the effect in a redeclaration should
+  /// generate a diagnostic.
+  bool diagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
+                             FunctionEffectSet OldFX,
+                             const FunctionDecl &NewFunction,
+                             FunctionEffectSet NewFX) const;
+
+  /// Return true if adding or removing the effect in a C++ virtual method
+  /// override should generate a diagnostic.
+  bool diagnoseMethodOverride(bool Adding, const CXXMethodDecl &OldMethod,
+                              FunctionEffectSet OldFX,
+                              const CXXMethodDecl &NewMethod,
+                              FunctionEffectSet NewFX) const;
+
+  /// Return true if the effect is allowed to be inferred on the specified Decl
+  /// (may be a FunctionDecl or BlockDecl). Only used if the effect has
+  /// FE_InferrableOnCallees flag set. Example: This allows nolock(false) to
+  /// prevent inference for the function.
+  bool canInferOnDecl(const Decl *Caller, FunctionEffectSet CallerFX) const;
+
+  // Called if FE_VerifyCalls flag is set; return false for success. When true
+  // is returned for a direct call, then the FE_InferrableOnCallees flag may
+  // trigger inference rather than an immediate diagnostic. Caller should be
+  // assumed to have the effect (it may not have it explicitly when inferring).
+  bool diagnoseFunctionCall(bool Direct, const Decl *Caller,
+                            FunctionEffectSet CallerFX, CalleeDeclOrType Callee,
+                            FunctionEffectSet CalleeFX) const;
+
+  friend bool operator==(const FunctionEffect &LHS, const FunctionEffect &RHS) {
+    return LHS.Type_ == RHS.Type_;
+  }
+  friend bool operator!=(const FunctionEffect &LHS, const FunctionEffect &RHS) {
+    return LHS.Type_ != RHS.Type_;
+  }
+  friend bool operator<(const FunctionEffect &LHS, const FunctionEffect &RHS) {
+    return LHS.Type_ < RHS.Type_;
+  }
+};
+
 // It is the user's responsibility to keep this in set form: elements are
 // ordered and unique.
 // We could hide the mutating methods which are capable of breaking the
 // invariant, but they're needed and safe when used with STL set algorithms.
-class MutableFunctionEffectSet : public SmallVector<const FunctionEffect *, 4> {
+class MutableFunctionEffectSet : public SmallVector<FunctionEffect, 4> {
 public:
   using SmallVector::insert;
   using SmallVector::SmallVector;
 
+  MutableFunctionEffectSet(const FunctionEffect &Effect);
+  using Base = SmallVector<FunctionEffect, 4>;
+
   /// Maintains order/uniquenesss.
-  void insert(const FunctionEffect *effect);
+  void insert(const FunctionEffect &Effect);
+
+  MutableFunctionEffectSet &operator|=(FunctionEffectSet RHS);
 
-  MutableFunctionEffectSet &operator|=(FunctionEffectSet rhs);
+  operator llvm::ArrayRef<const FunctionEffect>() const {
+    return {data(), size()};
+  }
 };
 
+/// A constant, uniqued set of FunctionEffect instances.
+// These sets will tend to be very small (0-1 elements), so represent them as
+// sorted spans, which are compatible with the STL set algorithms.
 class FunctionEffectSet {
-public:
-  // These sets will tend to be very small (1 element), so represent them as
-  // sorted vectors, which are compatible with the STL set algorithms. Using an
-  // array or vector also means the elements are contiguous, keeping iterators
-  // simple.
-
 private:
-  // 'Uniqued' refers to the set itself being uniqued. Storage is allocated
-  // separately. Use ArrayRef for its iterators. Subclass so as to be able to
-  // compare (it seems ArrayRef would silently convert itself to a vector for
-  // comparison?!).
-  class UniquedAndSortedFX : public llvm::ArrayRef<const FunctionEffect *> {
-  public:
-    using Base = llvm::ArrayRef<const FunctionEffect *>;
-
-    UniquedAndSortedFX(Base Array) : Base(Array) {}
-    UniquedAndSortedFX(const FunctionEffect **Ptr, size_t Len)
-        : Base(Ptr, Len) {}
-
-    bool operator<(const UniquedAndSortedFX &rhs) const;
-  };
-
-  // Could have used a TinyPtrVector if it were unique-able.
-  // Empty set has a null Impl.
-  llvm::PointerUnion<const FunctionEffect *, const UniquedAndSortedFX *> Impl;
+  explicit FunctionEffectSet(llvm::ArrayRef<const FunctionEffect> Array)
+      : Impl(Array) {}
 
-  explicit FunctionEffectSet(const FunctionEffect *Single) : Impl(Single) {}
-  explicit FunctionEffectSet(const UniquedAndSortedFX *Multi) : Impl(Multi) {}
+  // Points to a separately allocated array, uniqued.
+  llvm::ArrayRef<const FunctionEffect> Impl;
 
 public:
-  using Differences =
-      SmallVector<std::pair<const FunctionEffect *, /*added=*/bool>>;
+  using Differences = SmallVector<std::pair<FunctionEffect, /*added=*/bool>>;
 
-  FunctionEffectSet() : Impl(nullptr) {}
+  FunctionEffectSet() = default;
 
-  void *getOpaqueValue() const { return Impl.getOpaqueValue(); }
+  const void *getOpaqueValue() const { return Impl.data(); }
 
   explicit operator bool() const { return !empty(); }
-  bool empty() const {
-    if (Impl.isNull())
-      return true;
-    if (const UniquedAndSortedFX *Vec =
-            dyn_cast_if_present<const UniquedAndSortedFX *>(Impl))
-      return Vec->empty();
-    return false;
-  }
-  size_t size() const {
-    if (empty())
-      return 0;
-    if (isa<const FunctionEffect *>(Impl))
-      return 1;
-    return cast<const UniquedAndSortedFX *>(Impl)->size();
-  }
+  bool empty() const { return Impl.empty(); }
+  size_t size() const { return Impl.size(); }
 
-  using iterator = const FunctionEffect *const *;
+  using iterator = const FunctionEffect *;
 
-  iterator begin() const {
-    if (isa<const FunctionEffect *>(Impl))
-      return Impl.getAddrOfPtr1();
-    return cast<const UniquedAndSortedFX *>(Impl)->begin();
-  }
+  iterator begin() const { return Impl.begin(); }
 
-  iterator end() const {
-    if (isa<const FunctionEffect *>(Impl))
-      return begin() + (Impl.isNull() ? 0 : 1);
-    return cast<const UniquedAndSortedFX *>(Impl)->end();
-  }
+  iterator end() const { return Impl.end(); }
 
-  ArrayRef<const FunctionEffect *> items() const { return {begin(), end()}; }
+  ArrayRef<const FunctionEffect> items() const { return Impl; }
 
-  bool operator==(const FunctionEffectSet &other) const {
-    return Impl == other.Impl;
+  bool operator==(const FunctionEffectSet &RHS) const {
+    return Impl.data() == RHS.Impl.data();
   }
-  bool operator!=(const FunctionEffectSet &other) const {
-    return Impl != other.Impl;
+  bool operator!=(const FunctionEffectSet &RHS) const {
+    return Impl.data() != RHS.Impl.data();
   }
-  bool operator<(const FunctionEffectSet &other) const;
+  bool operator<(const FunctionEffectSet &RHS) const;
 
   void dump(llvm::raw_ostream &OS) const;
 
-  /// Factory functions: return instances with uniqued implementations.
-  static FunctionEffectSet create(const FunctionEffect &single) {
-    return FunctionEffectSet{&single};
-  }
-  static FunctionEffectSet create(llvm::ArrayRef<const FunctionEffect *> items);
+  /// Factory function: returns instances with uniqued implementations.
+  static FunctionEffectSet create(ASTContext &C,
+                                  const MutableFunctionEffectSet &FX);
 
-  /// Union. Caller should check for incompatible effects.
-  FunctionEffectSet operator|(const FunctionEffectSet &rhs) const;
   /// Intersection.
-  MutableFunctionEffectSet operator&(const FunctionEffectSet &rhs) const;
+  MutableFunctionEffectSet operator&(const FunctionEffectSet &RHS) const;
   /// Difference.
-  MutableFunctionEffectSet operator-(const FunctionEffectSet &rhs) const;
+  MutableFunctionEffectSet operator-(const FunctionEffectSet &RHS) const;
+
+  static FunctionEffectSet getUnion(ASTContext &C, const FunctionEffectSet &LHS,
+                                    const FunctionEffectSet &RHS);
 
   /// Caller should short-circuit by checking for equality first.
   static Differences differences(const FunctionEffectSet &Old,
@@ -7901,147 +7982,6 @@ QualType DecayedType::getPointeeType() const {
 void FixedPointValueToString(SmallVectorImpl<char> &Str, llvm::APSInt Val,
                              unsigned Scale);
 
-// ------------------------------------------------------------------------------
-
-// TODO: Should FunctionEffect be located elsewhere, where Decl is not
-// forward-declared?
-class Decl;
-class CXXMethodDecl;
-
-/// Represents an abstract function effect.
-class FunctionEffect {
-public:
-  enum class Type : unsigned char {
-    NoLockTrue,
-    NoAllocTrue,
-  };
-
-  /// Flags describing behaviors of the effect.
-  // (Why not a struct with bitfields? There's one function that would like to
-  // test a caller-specified bit. There are some potential optimizations that
-  // would OR together the bits of multiple effects.)
-  using Flags = unsigned;
-  enum FlagBit : unsigned {
-    // Some effects require verification, e.g. nolock(true); others might not?
-    // (no example yet; TODO: maybe always true, vestigial from nolock(false)).
-    FE_RequiresVerification = 0x1,
-
-    // Does this effect want to verify all function calls originating in
-    // functions having this effect? TODO: maybe always true, vestigial.
-    FE_VerifyCalls = 0x2,
-
-    // Can verification inspect callees' implementations? (e.g. nolock: yes,
-    // tcb+types: no)
-    FE_InferrableOnCallees = 0x4,
-
-    // Language constructs which effects can diagnose as disallowed.
-    FE_ExcludeThrow = 0x8,
-    FE_ExcludeCatch = 0x10,
-    FE_ExcludeObjCMessageSend = 0x20,
-    FE_ExcludeStaticLocalVars = 0x40,
-    FE_ExcludeThreadLocalVars = 0x80
-  };
-
-private:
-  const Type Type_;
-  const Flags Flags_;
-  const char *Name;
-
-public:
-  using CalleeDeclOrType =
-      llvm::PointerUnion<const Decl *, const FunctionProtoType *>;
-
-  FunctionEffect(Type T, Flags F, const char *Name)
-      : Type_(T), Flags_(F), Name(Name) {}
-  virtual ~FunctionEffect();
-
-  /// The type of the effect.
-  Type type() const { return Type_; }
-
-  /// Flags describing behaviors of the effect.
-  Flags flags() const { return Flags_; }
-
-  /// The description printed in diagnostics, e.g. 'nolock'.
-  StringRef name() const { return Name; }
-
-  /// The description used by TypePrinter, e.g. __attribute__((clang_nolock))
-  virtual std::string attribute() const = 0;
-
-  /// Return true if adding or removing the effect as part of a type conversion
-  /// should generate a diagnostic.
-  virtual bool diagnoseConversion(bool Adding, QualType OldType,
-                                  FunctionEffectSet OldFX, QualType NewType,
-                                  FunctionEffectSet NewFX) const;
-
-  /// Return true if adding or removing the effect in a redeclaration should
-  /// generate a diagnostic.
-  virtual bool diagnoseRedeclaration(bool Adding,
-                                     const FunctionDecl &OldFunction,
-                                     FunctionEffectSet OldFX,
-                                     const FunctionDecl &NewFunction,
-                                     FunctionEffectSet NewFX) const;
-
-  /// Return true if adding or removing the effect in a C++ virtual method
-  /// override should generate a diagnostic.
-  virtual bool diagnoseMethodOverride(bool Adding,
-                                      const CXXMethodDecl &OldMethod,
-                                      FunctionEffectSet OldFX,
-                                      const CXXMethodDecl &NewMethod,
-                                      FunctionEffectSet NewFX) const;
-
-  /// Return true if the effect is allowed to be inferred on the specified Decl
-  /// (may be a FunctionDecl or BlockDecl). Only used if the effect has
-  /// kInferrableOnCallees flag set. Example: This allows nolock(false) to
-  /// prevent inference for the function.
-  virtual bool canInferOnDecl(const Decl *Caller,
-                              FunctionEffectSet CallerFX) const;
-
-  // Called if kVerifyCalls flag is set; return false for success. When true is
-  // returned for a direct call, then the kInferrableOnCallees flag may trigger
-  // inference rather than an immediate diagnostic. Caller should be assumed to
-  // have the effect (it may not have it explicitly when inferring).
-  virtual bool diagnoseFunctionCall(bool Direct, const Decl *Caller,
-                                    FunctionEffectSet CallerFX,
-                                    CalleeDeclOrType Callee,
-                                    FunctionEffectSet CalleeFX) const;
-};
-
-/// FunctionEffect subclass for nolock and noalloc (whose behaviors are close
-/// to identical).
-class NoLockNoAllocEffect : public FunctionEffect {
-  bool isNoLock() const { return type() == Type::NoLockTrue; }
-
-public:
-  static const NoLockNoAllocEffect &nolock_instance();
-  static const NoLockNoAllocEffect &noalloc_instance();
-
-  NoLockNoAllocEffect(Type Type, const char *Name);
-  ~NoLockNoAllocEffect() override;
-
-  std::string attribute() const override;
-
-  bool diagnoseConversion(bool Adding, QualType OldType,
-                          FunctionEffectSet OldFX, QualType NewType,
-                          FunctionEffectSet NewFX) const override;
-
-  bool diagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
-                             FunctionEffectSet OldFX,
-                             const FunctionDecl &NewFunction,
-                             FunctionEffectSet NewFX) const override;
-
-  bool diagnoseMethodOverride(bool Adding, const CXXMethodDecl &OldMethod,
-                              FunctionEffectSet OldFX,
-                              const CXXMethodDecl &NewMethod,
-                              FunctionEffectSet NewFX) const override;
-
-  bool canInferOnDecl(const Decl *Caller,
-                      FunctionEffectSet CallerFX) const override;
-
-  bool diagnoseFunctionCall(bool Direct, const Decl *Caller,
-                            FunctionEffectSet CallerFX, CalleeDeclOrType Callee,
-                            FunctionEffectSet CalleeFX) const override;
-};
-
 } // namespace clang
 
 #endif // LLVM_CLANG_AST_TYPE_H
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 0afc61ff6de487..8a9922594e9f98 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -4922,12 +4922,58 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
           getTypeConstraintConcept(), getTypeConstraintArguments());
 }
 
-FunctionEffect::~FunctionEffect() = default;
+FunctionEffect::FunctionEffect(Type T) : Type_(T), Flags_(0), Unused(0) {
+  switch (T) {
+  case Type::NoLockTrue:
+    Flags_ = FE_RequiresVerification | FE_VerifyCalls | FE_InferrableOnCallees |
+             FE_ExcludeThrow | FE_ExcludeCatch | FE_ExcludeObjCMessageSend |
+             FE_ExcludeStaticLocalVars | FE_ExcludeThreadLocalVars;
+    break;
+
+  case Type::NoAllocTrue:
+    // Same as NoLockTrue, except without FE_ExcludeStaticLocalVars
+    Flags_ = FE_RequiresVerification | FE_VerifyCalls | FE_InferrableOnCallees |
+             FE_ExcludeThrow | FE_ExcludeCatch | FE_ExcludeObjCMessageSend |
+             FE_ExcludeThreadLocalVars;
+    break;
+  default:
+    break;
+  }
+}
+
+StringRef FunctionEffect::name() const {
+  switch (Type_) {
+  default:
+    return "";
+  case Type::NoLockTrue:
+    return "nolock";
+  case Type::NoAllocTrue:
+    return "noalloc";
+  }
+}
 
 bool FunctionEffect::diagnoseConversion(bool Adding, QualType OldType,
                                         FunctionEffectSet OldFX,
                                         QualType NewType,
                                         FunctionEffectSet NewFX) const {
+
+  switch (Type_) {
+  case Type::NoAllocTrue:
+    // noalloc can't be added (spoofed) during a conversion, unless we have
+    // nolock
+    if (Adding) {
+      for (const auto &Effect : OldFX) {
+        if (Effect.type() == Type::NoLockTrue)
+          return false;
+      }
+    }
+    [[fallthrough]];
+  case Type::NoLockTrue:
+    // nolock can't be added (spoofed) during a conversion
+    return Adding;
+  default:
+    break;
+  }
   return false;
 }
 
@@ -4936,6 +4982,15 @@ bool FunctionEffect::diagnoseRedeclaration(bool Adding,
                                            FunctionEffectSet OldFX,
                                            const FunctionDecl &NewFunction,
                                            FunctionEffectSet NewFX) const {
+  switch (Type_) {
+  case Type::NoAllocTrue:
+  case Type::NoLockTrue:
+    // nolock/noalloc can't be removed in a redeclaration
+    // adding -> false, removing -> true (diagnose)
+    return !Adding;
+  default:
+    break;
+  }
   return false;
 }
 
@@ -4944,120 +4999,82 @@ bool FunctionEffect::diagnoseMethodOverride(bool Adding,
                                             FunctionEffectSet OldFX,
                                             const CXXMethodDecl &NewMethod,
                                             FunctionEffectSet NewFX) const {
+  switch (Type_) {
+  case Type::NoAllocTrue:
+  case Type::NoLockTrue:
+    // nolock/noalloc can't be removed from an override
+    // adding -> false, removing -> true (diagnose)
+    return !Adding;
+  default:
+    break;
+  }
   return false;
 }
 
 bool FunctionEffect::canInferOnDecl(const Decl *Caller,
                                     FunctionEffectSet CallerFX) const {
+  switch (Type_) {
+  case Type::NoAllocTrue:
+  case Type::NoLockTrue: {
+    // Does the Decl have nolock(false) / noalloc(false) ?
+    QualType QT;
+    if (isa<BlockDecl>(Caller)) {
+      const auto *TSI = cast<BlockDecl>(Caller)->getSignatureAsWritten();
+      QT = TSI->getType();
+    } else if (isa<ValueDecl>(Caller)) {
+      QT = cast<ValueDecl>(Caller)->getType();
+    } else {
+      return false;
+    }
+    if (QT->hasAttr(type() == Type::NoLockTrue ? attr::Kind::NoLock
+                                               : attr::Kind::NoAlloc)) {
+      return false;
+    }
+
+    return true;
+  }
+
+  default:
+    break;
+  }
   return false;
 }
 
+// TODO: Notice that we don't care about some of the parameters. Is the
+// interface overly general?
 bool FunctionEffect::diagnoseFunctionCall(bool Direct, const Decl *Caller,
                                           FunctionEffectSet CallerFX,
                                           CalleeDeclOrType Callee,
                                           FunctionEffectSet CalleeFX) const {
-  return false;
-}
-
-const NoLockNoAllocEffect &NoLockNoAllocEffect::nolock_instance() {
-  static NoLockNoAllocEffect global(Type::NoLockTrue, "nolock");
-  return global;
-}
-
-const NoLockNoAllocEffect &NoLockNoAllocEffect::noalloc_instance() {
-  static NoLockNoAllocEffect global(Type::NoAllocTrue, "noalloc");
-  return global;
-}
-
-// TODO: Separate flags for noalloc
-NoLockNoAllocEffect::NoLockNoAllocEffect(Type Ty, const char *Name)
-    : FunctionEffect(Ty,
-                     FE_RequiresVerification | FE_VerifyCalls |
-                         FE_InferrableOnCallees | FE_ExcludeThrow |
-                         FE_ExcludeCatch | FE_ExcludeObjCMessageSend |
-                         FE_ExcludeStaticLocalVars | FE_ExcludeThreadLocalVars,
-                     Name) {}
-
-NoLockNoAllocEffect::~NoLockNoAllocEffect() = default;
-
-std::string NoLockNoAllocEffect::attribute() const {
-  return std::string{"__attribute__((clang_"} + name().str() + "))";
-}
-
-bool NoLockNoAllocEffect::diagnoseConversion(bool Adding, QualType OldType,
-                                             FunctionEffectSet OldFX,
-                                             QualType NewType,
-                                             FunctionEffectSet NewFX) const {
-  // noalloc can't be added (spoofed) during a conversion, unless we have nolock
-  if (Adding) {
-    if (!isNoLock()) {
-      for (const auto *Effect : OldFX) {
-        if (Effect->type() == Type::NoLockTrue)
-          return false;
+  switch (Type_) {
+  case Type::NoAllocTrue:
+  case Type::NoLockTrue: {
+    const Type CallerType = type();
+    for (const auto &Effect : CalleeFX) {
+      const Type ET = Effect.type();
+      // Does callee have same or stronger constraint?
+      if (ET == CallerType ||
+          (CallerType == Type::NoAllocTrue && ET == Type::NoLockTrue)) {
+        return false; // no diagnostic
       }
     }
-    // nolock can't be added (spoofed) during a conversion.
-    return true;
+    return true; // warning
+  }
+  default:
+    break;
   }
   return false;
 }
 
-bool NoLockNoAllocEffect::diagnoseRedeclaration(bool Adding,
-                                                const FunctionDecl &OldFunction,
-                                                FunctionEffectSet OldFX,
-                                                const FunctionDecl &NewFunction,
-                                                FunctionEffectSet NewFX) const {
-  // nolock/noalloc can't be removed in a redeclaration
-  // adding -> false, removing -> true (diagnose)
-  return !Adding;
-}
-
-bool NoLockNoAllocEffect::diagnoseMethodOverride(
-    bool Adding, const CXXMethodDecl &OldMethod, FunctionEffectSet OldFX,
-    const CXXMethodDecl &NewMethod, FunctionEffectSet NewFX) const {
-  // nolock/noalloc can't be removed from an override
-  return !Adding;
-}
-
-bool NoLockNoAllocEffect::canInferOnDecl(const Decl *Caller,
-                                         FunctionEffectSet CallerFX) const {
-  // Does the Decl have nolock(false) / noalloc(false) ?
-  QualType QT;
-  if (isa<BlockDecl>(Caller)) {
-    const auto *TSI = cast<BlockDecl>(Caller)->getSignatureAsWritten();
-    QT = TSI->getType();
-  } else if (isa<ValueDecl>(Caller)) {
-    QT = cast<ValueDecl>(Caller)->getType();
-  } else {
-    return false;
-  }
-  if (QT->hasAttr(isNoLock() ? attr::Kind::NoLock : attr::Kind::NoAlloc)) {
-    return false;
-  }
-
-  return true;
-}
+// =====
 
-// TODO: Notice that we don't care about some of the parameters. Is the
-// interface overly general?
-bool NoLockNoAllocEffect::diagnoseFunctionCall(
-    bool Direct, const Decl *Caller, FunctionEffectSet CallerFX,
-    CalleeDeclOrType Callee, FunctionEffectSet CalleeFX) const {
-  const Type CallerType = type();
-  for (const auto *Effect : CalleeFX) {
-    const Type ET = Effect->type();
-    if (ET == CallerType ||
-        (CallerType == Type::NoAllocTrue && ET == Type::NoLockTrue)) {
-      return false;
-    }
-  }
-  return true;
+MutableFunctionEffectSet::MutableFunctionEffectSet(
+    const FunctionEffect &effect) {
+  push_back(effect);
 }
 
-// =====
-
-void MutableFunctionEffectSet::insert(const FunctionEffect *Effect) {
-  auto Iter = std::lower_bound(begin(), end(), Effect);
+void MutableFunctionEffectSet::insert(const FunctionEffect &Effect) {
+  const auto &Iter = std::lower_bound(begin(), end(), Effect);
   if (*Iter != Effect) {
     insert(Iter, Effect);
   }
@@ -5066,55 +5083,81 @@ void MutableFunctionEffectSet::insert(const FunctionEffect *Effect) {
 MutableFunctionEffectSet &
 MutableFunctionEffectSet::operator|=(FunctionEffectSet RHS) {
   // TODO: For large RHS sets, use set_union or a custom insert-in-place
-  for (const auto *Effect : RHS) {
+  for (const auto &Effect : RHS) {
     insert(Effect);
   }
   return *this;
 }
 
-// This could be simpler if there were a simple set container that could be
-// queried by ArrayRef but which stored something else. Possibly a DenseMap with
-// void values?
-FunctionEffectSet
-FunctionEffectSet::create(llvm::ArrayRef<const FunctionEffect *> Items) {
-  if (Items.empty()) {
-    return FunctionEffectSet{};
+using FunctionEffectSpan = llvm::ArrayRef<const FunctionEffect>;
+
+llvm::hash_code hash_value(const FunctionEffect &Effect) {
+  return Effect.opaqueRepr();
+}
+
+namespace llvm {
+template <> struct DenseMapInfo<FunctionEffectSpan> {
+  static FunctionEffectSpan getEmptyKey() {
+    return {static_cast<const FunctionEffect *>(nullptr), size_t(0)};
+  }
+  static FunctionEffectSpan getTombstoneKey() {
+    return {reinterpret_cast<const FunctionEffect *>(intptr_t(-1)), size_t(0)};
   }
-  if (Items.size() == 1) {
-    return FunctionEffectSet{Items[0]};
+  static unsigned getHashValue(const FunctionEffectSpan &Val) {
+    hash_code hash1 = hash_value(Val.size());
+    // Treat the FunctionEffects as a span of integers
+    const FunctionEffect *Begin = Val.begin();
+    const FunctionEffect *End = Val.end();
+    hash_code hash2 =
+        hash_combine_range(reinterpret_cast<const uint32_t *>(Begin),
+                           reinterpret_cast<const uint32_t *>(End));
+    return hash_combine(hash1, hash2);
+  }
+  static bool isEqual(const FunctionEffectSpan &LHS,
+                      const FunctionEffectSpan &RHS) {
+    if (LHS.size() != RHS.size()) {
+      return false;
+    }
+    // distinguish empty from tombstone
+    if (LHS.size() == 0) {
+      return LHS.data() == RHS.data();
+    }
+    return std::equal(LHS.begin(), LHS.end(), RHS.begin());
   }
+};
+} // namespace llvm
 
-  UniquedAndSortedFX NewSet(Items); // just copies the ArrayRef
+// The ASTContext
+FunctionEffectSet
+FunctionEffectSet::create(ASTContext &C, const MutableFunctionEffectSet &FX) {
+  if (FX.empty()) {
+    return {};
+  }
 
-  // SmallSet only has contains(), so it provides no way to obtain the uniqued
-  // value.
   // TODO: Put this in the ASTContext
-  // TODO: Try making this a DenseSet? Requires more methods on the members.
-  // static llvm::DenseSet<UniquedAndSortedFX> UniquedFXSets;
-  // Punt on this until we revisit FunctionFX.
+  // TODO: And destroy the memory
+  static llvm::DenseSet<FunctionEffectSpan> UniquedFXSets;
 
-  static std::set<UniquedAndSortedFX> UniquedFXSets;
-
-  // See if we already have this set.
-  const auto Iter = UniquedFXSets.find(NewSet);
+  // Do we already have the incoming set?
+  const auto Iter = UniquedFXSets.find_as(FX);
   if (Iter != UniquedFXSets.end()) {
-    return FunctionEffectSet{&*Iter};
+    return FunctionEffectSet(*Iter);
   }
 
   // Copy the incoming array to permanent storage.
-  auto *Storage = new const FunctionEffect *[Items.size()];
-  std::copy(Items.begin(), Items.end(), Storage);
+  FunctionEffect *Storage = new FunctionEffect[FX.size()];
+  std::copy(FX.begin(), FX.end(), Storage);
 
   // Make a new wrapper and insert it into the set.
-  NewSet = UniquedAndSortedFX(Storage, Items.size());
-  auto [InsIter, _] = UniquedFXSets.insert(NewSet);
-  return FunctionEffectSet(&*InsIter);
+  auto [InsIter, _] =
+      UniquedFXSets.insert(FunctionEffectSpan(Storage, FX.size()));
+  return FunctionEffectSet(*InsIter);
 }
 
-FunctionEffectSet
-FunctionEffectSet::operator|(const FunctionEffectSet &RHS) const {
+FunctionEffectSet FunctionEffectSet::getUnion(ASTContext &C,
+                                              const FunctionEffectSet &LHS,
+                                              const FunctionEffectSet &RHS) {
   // Optimize for one of the two sets being empty
-  const FunctionEffectSet &LHS = *this;
   if (LHS.empty())
     return RHS;
   if (RHS.empty())
@@ -5129,7 +5172,7 @@ FunctionEffectSet::operator|(const FunctionEffectSet &RHS) const {
   std::set_union(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
                  std::back_inserter(Vec));
   // The result of a set operation is an ordered/unique set.
-  return FunctionEffectSet::create(Vec);
+  return FunctionEffectSet::create(C, Vec);
 }
 
 MutableFunctionEffectSet
@@ -5161,10 +5204,10 @@ FunctionEffectSet::differences(const FunctionEffectSet &Old,
                                const FunctionEffectSet &New) {
   // TODO: Could be a one-pass algorithm.
   Differences Result;
-  for (const auto *Effect : (New - Old)) {
+  for (const auto &Effect : (New - Old)) {
     Result.emplace_back(Effect, true);
   }
-  for (const auto *Effect : (Old - New)) {
+  for (const auto &Effect : (Old - New)) {
     Result.emplace_back(Effect, false);
   }
   return Result;
@@ -5186,20 +5229,15 @@ bool FunctionEffectSet::operator<(const FunctionEffectSet &RHS) const {
                                       RHS.end());
 }
 
-bool FunctionEffectSet::UniquedAndSortedFX::operator<(
-    const UniquedAndSortedFX &RHS) const {
-  return this < &RHS;
-}
-
 void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
-  OS << "FX{";
+  OS << "Effects{";
   bool First = true;
-  for (const auto *Effect : *this) {
+  for (const auto &Effect : *this) {
     if (!First)
       OS << ", ";
     else
       First = false;
-    OS << Effect->name();
+    OS << Effect.name();
   }
   OS << "}";
 }
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 252a5dfbc952b0..1f539616f04c2a 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -987,8 +987,8 @@ void TypePrinter::printFunctionProtoAfter(const FunctionProtoType *T,
   T->printExceptionSpecification(OS, Policy);
 
   if (const FunctionEffectSet FX = T->getFunctionEffects()) {
-    for (const auto *Effect : FX) {
-      OS << " " << Effect->attribute();
+    for (const auto &Effect : FX) {
+      OS << " __attribute__((clang_" << Effect.name() << "))";
     }
   }
 
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index cf9b1244e81bfd..ce7b91d4a5e59e 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2406,14 +2406,14 @@ enum class DiagnosticID : uint8_t {
 };
 
 struct Diagnostic {
-  const FunctionEffect *Effect = nullptr;
+  FunctionEffect Effect;
   const Decl *Callee = nullptr; // only valid for Calls*
   SourceLocation Loc;
   DiagnosticID ID = DiagnosticID::None;
 
   Diagnostic() = default;
 
-  Diagnostic(const FunctionEffect *Effect, DiagnosticID ID, SourceLocation Loc,
+  Diagnostic(const FunctionEffect &Effect, DiagnosticID ID, SourceLocation Loc,
              const Decl *Callee = nullptr)
       : Effect(Effect), Callee(Callee), Loc(Loc), ID(ID) {}
 };
@@ -2521,12 +2521,12 @@ class EffectToDiagnosticMap {
   // Since we currently only have a tiny number of effects (typically no more
   // than 1), use a sorted SmallVector with an inline capacity of 1. Since it
   // is often empty, use a unique_ptr to the SmallVector.
-  using Element = std::pair<const FunctionEffect *, Diagnostic>;
+  using Element = std::pair<FunctionEffect, Diagnostic>;
   using ImplVec = llvm::SmallVector<Element, 1>;
   std::unique_ptr<ImplVec> Impl;
 
 public:
-  Diagnostic &getOrInsertDefault(const FunctionEffect *Key) {
+  Diagnostic &getOrInsertDefault(FunctionEffect Key) {
     if (Impl == nullptr) {
       Impl = std::make_unique<llvm::SmallVector<Element>>();
       auto &Item = Impl->emplace_back();
@@ -2542,7 +2542,7 @@ class EffectToDiagnosticMap {
     return Iter->second;
   }
 
-  const Diagnostic *lookup(const FunctionEffect *key) {
+  const Diagnostic *lookup(FunctionEffect key) {
     if (Impl == nullptr) {
       return nullptr;
     }
@@ -2596,20 +2596,20 @@ class PendingFunctionAnalysis {
   std::unique_ptr<SmallVector<DirectCall>> UnverifiedDirectCalls;
 
 public:
-  PendingFunctionAnalysis(const CallableInfo &cinfo,
+  PendingFunctionAnalysis(ASTContext &Ctx, const CallableInfo &cinfo,
                           FunctionEffectSet AllInferrableEffectsToVerify) {
     MutableFunctionEffectSet fx;
-    for (const auto *effect : cinfo.Effects) {
-      if (effect->flags() & FunctionEffect::FE_RequiresVerification) {
+    for (const auto &effect : cinfo.Effects) {
+      if (effect.flags() & FunctionEffect::FE_RequiresVerification) {
         fx.insert(effect);
       }
     }
-    DeclaredVerifiableEffects = FunctionEffectSet::create(fx);
+    DeclaredVerifiableEffects = FunctionEffectSet::create(Ctx, fx);
 
     // Check for effects we are not allowed to infer
     fx.clear();
-    for (const auto *effect : AllInferrableEffectsToVerify) {
-      if (effect->canInferOnDecl(cinfo.CDecl, cinfo.Effects)) {
+    for (const auto &effect : AllInferrableEffectsToVerify) {
+      if (effect.canInferOnDecl(cinfo.CDecl, cinfo.Effects)) {
         fx.insert(effect);
       } else {
         // Add a diagnostic for this effect if a caller were to
@@ -2622,8 +2622,8 @@ class PendingFunctionAnalysis {
       }
     }
     // fx is now the set of inferrable effects which are not prohibited
-    FXToInfer = FunctionEffectSet::create(FunctionEffectSet::create(fx) -
-                                          DeclaredVerifiableEffects);
+    FXToInfer = FunctionEffectSet::create(
+        Ctx, FunctionEffectSet::create(Ctx, fx) - DeclaredVerifiableEffects);
   }
 
   // Hide the way that diagnostics for explicitly required effects vs. inferred
@@ -2655,8 +2655,7 @@ class PendingFunctionAnalysis {
     return UnverifiedDirectCalls == nullptr || UnverifiedDirectCalls->empty();
   }
 
-  const Diagnostic *
-  diagnosticForInferrableEffect(const FunctionEffect *effect) {
+  const Diagnostic *diagnosticForInferrableEffect(FunctionEffect effect) {
     return InferrableEffectToFirstDiagnostic.lookup(effect);
   }
 
@@ -2696,23 +2695,23 @@ class CompleteFunctionAnalysis {
   EffectToDiagnosticMap InferrableEffectToFirstDiagnostic;
 
 public:
-  CompleteFunctionAnalysis(PendingFunctionAnalysis &pending,
+  CompleteFunctionAnalysis(ASTContext &Ctx, PendingFunctionAnalysis &pending,
                            FunctionEffectSet funcFX,
                            FunctionEffectSet AllInferrableEffectsToVerify) {
     MutableFunctionEffectSet verified;
     verified |= funcFX;
-    for (const auto *effect : AllInferrableEffectsToVerify) {
+    for (const auto &effect : AllInferrableEffectsToVerify) {
       if (pending.diagnosticForInferrableEffect(effect) == nullptr) {
         verified.insert(effect);
       }
     }
-    VerifiedEffects = FunctionEffectSet::create(verified);
+    VerifiedEffects = FunctionEffectSet::create(Ctx, verified);
 
     InferrableEffectToFirstDiagnostic =
         std::move(pending.InferrableEffectToFirstDiagnostic);
   }
 
-  const Diagnostic *firstDiagnosticForEffect(const FunctionEffect *effect) {
+  const Diagnostic *firstDiagnosticForEffect(const FunctionEffect &effect) {
     // TODO: is this correct?
     return InferrableEffectToFirstDiagnostic.lookup(effect);
   }
@@ -2806,14 +2805,14 @@ class Analyzer {
     // be checked, and to see which ones are inferrable.
     {
       MutableFunctionEffectSet inferrableEffects;
-      for (const FunctionEffect *effect : Sem.AllEffectsToVerify) {
-        const auto Flags = effect->flags();
+      for (const FunctionEffect &effect : Sem.AllEffectsToVerify) {
+        const auto Flags = effect.flags();
         if (Flags & FunctionEffect::FE_InferrableOnCallees) {
           inferrableEffects.insert(effect);
         }
       }
       AllInferrableEffectsToVerify =
-          FunctionEffectSet::create(inferrableEffects);
+          FunctionEffectSet::create(Sem.getASTContext(), inferrableEffects);
       llvm::outs() << "AllInferrableEffectsToVerify: ";
       AllInferrableEffectsToVerify.dump(llvm::outs());
       llvm::outs() << "\n";
@@ -2887,7 +2886,8 @@ class Analyzer {
     // Build a PendingFunctionAnalysis on the stack. If it turns out to be
     // complete, we'll have avoided a heap allocation; if it's incomplete, it's
     // a fairly trivial move to a heap-allocated object.
-    PendingFunctionAnalysis FAnalysis(CInfo, AllInferrableEffectsToVerify);
+    PendingFunctionAnalysis FAnalysis(Sem.getASTContext(), CInfo,
+                                      AllInferrableEffectsToVerify);
 
     llvm::outs() << "\nVerifying " << CInfo.name(Sem) << " ";
     FAnalysis.dump(llvm::outs());
@@ -2915,7 +2915,8 @@ class Analyzer {
       emitDiagnostics(*Diags, CInfo, Sem);
     }
     auto *CompletePtr = new CompleteFunctionAnalysis(
-        Pending, CInfo.Effects, AllInferrableEffectsToVerify);
+        Sem.getASTContext(), Pending, CInfo.Effects,
+        AllInferrableEffectsToVerify);
     DeclAnalysis[CInfo.CDecl] = CompletePtr;
     llvm::outs() << "inserted complete " << CompletePtr << "\n";
     DeclAnalysis.dump(Sem, llvm::outs());
@@ -2964,10 +2965,10 @@ class Analyzer {
     llvm::outs() << "\n";
     puts("");
 
-    auto check1Effect = [&](const FunctionEffect *Effect, bool Inferring) {
-      const auto Flags = Effect->flags();
+    auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
+      const auto Flags = Effect.flags();
       if (Flags & FunctionEffect::FE_VerifyCalls) {
-        const bool diagnose = Effect->diagnoseFunctionCall(
+        const bool diagnose = Effect.diagnoseFunctionCall(
             DirectCall, Caller.CDecl, Caller.Effects, Callee.CDecl,
             CalleeEffects);
         if (diagnose) {
@@ -2991,11 +2992,11 @@ class Analyzer {
       }
     };
 
-    for (auto *Effect : PFA.DeclaredVerifiableEffects) {
+    for (const auto &Effect : PFA.DeclaredVerifiableEffects) {
       check1Effect(Effect, false);
     }
 
-    for (auto *Effect : PFA.FXToInfer) {
+    for (const auto &Effect : PFA.FXToInfer) {
       check1Effect(Effect, true);
     }
   }
@@ -3026,7 +3027,7 @@ class Analyzer {
 
     // Top-level diagnostics are warnings.
     for (const auto &Diag : Diags) {
-      StringRef effectName = Diag.Effect->name();
+      StringRef effectName = Diag.Effect.name();
       switch (Diag.ID) {
       case DiagnosticID::None:
       case DiagnosticID::DeclWithoutConstraintOrInference: // shouldn't happen
@@ -3230,22 +3231,22 @@ class Analyzer {
                                    const Decl *Callee = nullptr) {
       // If there are ANY declared verifiable effects holding the flag, store
       // just one diagnostic.
-      for (auto *Effect : CurrentFunction.DeclaredVerifiableEffects) {
-        if (Effect->flags() & Flag) {
+      for (const auto &Effect : CurrentFunction.DeclaredVerifiableEffects) {
+        if (Effect.flags() & Flag) {
           addDiagnosticInner(/*inferring=*/false, Effect, D, Loc, Callee);
           break;
         }
       }
       // For each inferred-but-not-verifiable effect holding the flag, store a
       // diagnostic, if we don't already have a diagnostic for that effect.
-      for (auto *Effect : CurrentFunction.FXToInfer) {
-        if (Effect->flags() & Flag) {
+      for (const auto &Effect : CurrentFunction.FXToInfer) {
+        if (Effect.flags() & Flag) {
           addDiagnosticInner(/*inferring=*/true, Effect, D, Loc, Callee);
         }
       }
     }
 
-    void addDiagnosticInner(bool Inferring, const FunctionEffect *Effect,
+    void addDiagnosticInner(bool Inferring, const FunctionEffect &Effect,
                             DiagnosticID D, SourceLocation Loc,
                             const Decl *Callee = nullptr) {
       CurrentFunction.checkAddDiagnostic(Inferring,
@@ -3264,25 +3265,25 @@ class Analyzer {
       auto *FPT =
           CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
 
-      auto check1Effect = [&](const FunctionEffect *effect, bool inferring) {
-        if (effect->flags() & FunctionEffect::FE_VerifyCalls) {
+      auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
+        if (Effect.flags() & FunctionEffect::FE_VerifyCalls) {
           if (FPT == nullptr ||
-              effect->diagnoseFunctionCall(
+              Effect.diagnoseFunctionCall(
                   /*direct=*/false, CurrentCaller.CDecl, CurrentCaller.Effects,
                   FPT, FPT->getFunctionEffects())) {
-            addDiagnosticInner(inferring, effect,
+            addDiagnosticInner(Inferring, Effect,
                                DiagnosticID::CallsDisallowedExpr,
                                Call->getBeginLoc());
           }
         }
       };
 
-      for (auto *effect : CurrentFunction.DeclaredVerifiableEffects) {
-        check1Effect(effect, false);
+      for (const auto &Effect : CurrentFunction.DeclaredVerifiableEffects) {
+        check1Effect(Effect, false);
       }
 
-      for (auto *effect : CurrentFunction.FXToInfer) {
-        check1Effect(effect, true);
+      for (const auto &Effect : CurrentFunction.FXToInfer) {
+        check1Effect(Effect, true);
       }
     }
 
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 8e96522542427a..05b771939feb13 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -592,12 +592,12 @@ void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
   const auto DstFX = FunctionEffectSet::get(*DstType);
   if (SrcFX != DstFX) {
     for (const auto &Item : FunctionEffectSet::differences(SrcFX, DstFX)) {
-      const FunctionEffect *Effect = Item.first;
+      const FunctionEffect &Effect = Item.first;
       const bool Adding = Item.second;
-      if (Effect->diagnoseConversion(Adding, SrcType, SrcFX, DstType, DstFX)) {
+      if (Effect.diagnoseConversion(Adding, SrcType, SrcFX, DstType, DstFX)) {
         Diag(Loc, Adding ? diag::warn_invalid_add_func_effects
                          : diag::warn_invalid_remove_func_effects)
-            << Effect->name();
+            << Effect.name();
       }
     }
   }
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index d860804102dfc9..1f167467cad6d1 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3927,17 +3927,17 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
   if (OldFX != NewFX) {
     const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
     for (const auto &Item : Diffs) {
-      const FunctionEffect *Effect = Item.first;
+      const FunctionEffect &Effect = Item.first;
       const bool Adding = Item.second;
-      if (Effect->diagnoseRedeclaration(Adding, *Old, OldFX, *New, NewFX)) {
+      if (Effect.diagnoseRedeclaration(Adding, *Old, OldFX, *New, NewFX)) {
         Diag(New->getLocation(),
              diag::warn_mismatched_func_effect_redeclaration)
-            << Effect->name();
+            << Effect.name();
         Diag(Old->getLocation(), diag::note_previous_declaration);
       }
     }
 
-    const auto MergedFX = OldFX | NewFX;
+    const auto MergedFX = FunctionEffectSet::getUnion(Context, OldFX, NewFX);
 
     // Having diagnosed any problems, prevent further errors by applying the
     // merged set of effects to both declarations.
@@ -11165,8 +11165,8 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
   // Filter out declarations that the FunctionEffect analysis should skip
   // and not verify.
   bool FXNeedVerification = false;
-  for (const auto *Effect : FX) {
-    if (Effect->flags() & FunctionEffect::FE_RequiresVerification) {
+  for (const auto &Effect : FX) {
+    if (Effect.flags() & FunctionEffect::FE_RequiresVerification) {
       AllEffectsToVerify.insert(Effect);
       FXNeedVerification = true;
     }
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 2f9a4a14155fb4..2c163ce4c14b03 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18330,11 +18330,11 @@ bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
     bool AnyDiags = false;
 
     for (const auto &Item : Diffs) {
-      const FunctionEffect *Effect = Item.first;
+      const FunctionEffect &Effect = Item.first;
       const bool Adding = Item.second;
-      if (Effect->diagnoseMethodOverride(Adding, *Old, OldFX, *New, NewFX)) {
+      if (Effect.diagnoseMethodOverride(Adding, *Old, OldFX, *New, NewFX)) {
         Diag(New->getLocation(), diag::warn_mismatched_func_effect_override)
-            << Effect->name();
+            << Effect.name();
         Diag(Old->getLocation(), diag::note_overridden_virtual_function);
         AnyDiags = true;
       }
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index a7849f42d38c13..0fcafeb0172fb4 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8028,23 +8028,20 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
 
   // nolock(true) and noalloc(true) are represented as FunctionEffects, in a
   // FunctionEffectSet attached to a FunctionProtoType.
-  const FunctionEffect *Effect = nullptr;
-  if (isNoLock) {
-    Effect = &NoLockNoAllocEffect::nolock_instance();
-  } else {
-    Effect = &NoLockNoAllocEffect::noalloc_instance();
-  }
+  const FunctionEffect NewEffect(isNoLock ? FunctionEffect::Type::NoLockTrue
+                                          : FunctionEffect::Type::NoAllocTrue);
 
-  MutableFunctionEffectSet newEffectSet{Effect};
+  MutableFunctionEffectSet NewFX(NewEffect);
   if (EPI.FunctionEffects) {
     // Preserve any previous effects - except noalloc, when we are adding nolock
-    for (const auto *effect : EPI.FunctionEffects) {
-      if (!(isNoLock && effect->type() == FunctionEffect::Type::NoAllocTrue))
-        newEffectSet.insert(effect);
+    for (const auto &Effect : EPI.FunctionEffects) {
+      if (!(isNoLock && Effect.type() == FunctionEffect::Type::NoAllocTrue))
+        NewFX.insert(Effect);
     }
   }
 
-  EPI.FunctionEffects = FunctionEffectSet::create(newEffectSet);
+  EPI.FunctionEffects =
+      FunctionEffectSet::create(state.getSema().getASTContext(), NewFX);
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
                                                FPT->getParamTypes(), EPI);
   type = unwrapped.wrap(S, newtype->getAs<FunctionType>());

>From 2a5c14fe4ed70b5aea3b808fbe55ffb7d8f8f8eb Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Sat, 16 Mar 2024 10:19:25 -0700
Subject: [PATCH 11/40] Remove unused parameters from FunctionEffect interface.

---
 clang/include/clang/AST/Type.h           | 30 +++++++++---------
 clang/lib/AST/Type.cpp                   | 35 +++++++--------------
 clang/lib/Sema/AnalysisBasedWarnings.cpp | 39 +++++++++++++-----------
 3 files changed, 48 insertions(+), 56 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 1d277d2ef06b19..4da97c88a2257d 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4192,11 +4192,12 @@ class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
 class Decl;
 class CXXMethodDecl;
 class FunctionEffectSet;
+class TypeSourceInfo;
 
 /// Represents an abstract function effect.
 class FunctionEffect {
 public:
-  enum class Type : unsigned char {
+  enum class Type {
     None = 0,
     NoLockTrue,
     NoAllocTrue,
@@ -4231,24 +4232,24 @@ class FunctionEffect {
 private:
   // For uniqueness, currently only Type_ is significant.
 
-  Type Type_ : 2;   // Expands when there are more types
+  LLVM_PREFERRED_TYPE(Type)
+  unsigned Type_ : 2;
   Flags Flags_ : 8; // A constant function of Type but cached here.
 
-  // Expansion: for hypothetical TCB+types, there could be one type for TCB,
+  // Expansion: for hypothetical TCB+types, there could be one Type for TCB,
   // then ~16(?) bits "Subtype" to map to a specific named TCB. Subtype would
   // be considered for uniqueness.
-  unsigned Unused : 22;
 
 public:
   using CalleeDeclOrType =
       llvm::PointerUnion<const Decl *, const FunctionProtoType *>;
 
-  FunctionEffect() : Type_(Type::None), Flags_(0), Unused(0) {}
+  FunctionEffect() : Type_(unsigned(Type::None)), Flags_(0) {}
 
   explicit FunctionEffect(Type T);
 
   /// The type of the effect.
-  Type type() const { return Type_; }
+  Type type() const { return Type(Type_); }
 
   /// Flags describing behaviors of the effect.
   Flags flags() const { return Flags_; }
@@ -4257,7 +4258,7 @@ class FunctionEffect {
   StringRef name() const;
 
   /// A serializable, hashable representation.
-  uint32_t opaqueRepr() const { return unsigned(Type_) | (Flags_ << 2u); }
+  uint32_t opaqueRepr() const { return Type_ | (Flags_ << 2u); }
 
   /// Return true if adding or removing the effect as part of a type conversion
   /// should generate a diagnostic.
@@ -4279,19 +4280,18 @@ class FunctionEffect {
                               const CXXMethodDecl &NewMethod,
                               FunctionEffectSet NewFX) const;
 
-  /// Return true if the effect is allowed to be inferred on the specified Decl
-  /// (may be a FunctionDecl or BlockDecl). Only used if the effect has
-  /// FE_InferrableOnCallees flag set. Example: This allows nolock(false) to
-  /// prevent inference for the function.
-  bool canInferOnDecl(const Decl *Caller, FunctionEffectSet CallerFX) const;
+  /// Return true if the effect is allowed to be inferred on a Decl of the
+  /// specified type (generally a FunctionProtoType but TypeSourceInfo is
+  /// provided so any AttributedType sugar can be examined). Only used if the
+  /// effect has FE_InferrableOnCallees flag set. Example: This allows
+  /// nolock(false) to prevent inference for the function.
+  bool canInferOnFunction(const TypeSourceInfo &FType) const;
 
   // Called if FE_VerifyCalls flag is set; return false for success. When true
   // is returned for a direct call, then the FE_InferrableOnCallees flag may
   // trigger inference rather than an immediate diagnostic. Caller should be
   // assumed to have the effect (it may not have it explicitly when inferring).
-  bool diagnoseFunctionCall(bool Direct, const Decl *Caller,
-                            FunctionEffectSet CallerFX, CalleeDeclOrType Callee,
-                            FunctionEffectSet CalleeFX) const;
+  bool diagnoseFunctionCall(bool Direct, FunctionEffectSet CalleeFX) const;
 
   friend bool operator==(const FunctionEffect &LHS, const FunctionEffect &RHS) {
     return LHS.Type_ == RHS.Type_;
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 8a9922594e9f98..e459833bb05150 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -4922,7 +4922,7 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
           getTypeConstraintConcept(), getTypeConstraintArguments());
 }
 
-FunctionEffect::FunctionEffect(Type T) : Type_(T), Flags_(0), Unused(0) {
+FunctionEffect::FunctionEffect(Type T) : Type_(unsigned(T)), Flags_(0) {
   switch (T) {
   case Type::NoLockTrue:
     Flags_ = FE_RequiresVerification | FE_VerifyCalls | FE_InferrableOnCallees |
@@ -4942,7 +4942,7 @@ FunctionEffect::FunctionEffect(Type T) : Type_(T), Flags_(0), Unused(0) {
 }
 
 StringRef FunctionEffect::name() const {
-  switch (Type_) {
+  switch (type()) {
   default:
     return "";
   case Type::NoLockTrue:
@@ -4957,7 +4957,7 @@ bool FunctionEffect::diagnoseConversion(bool Adding, QualType OldType,
                                         QualType NewType,
                                         FunctionEffectSet NewFX) const {
 
-  switch (Type_) {
+  switch (type()) {
   case Type::NoAllocTrue:
     // noalloc can't be added (spoofed) during a conversion, unless we have
     // nolock
@@ -4982,7 +4982,7 @@ bool FunctionEffect::diagnoseRedeclaration(bool Adding,
                                            FunctionEffectSet OldFX,
                                            const FunctionDecl &NewFunction,
                                            FunctionEffectSet NewFX) const {
-  switch (Type_) {
+  switch (type()) {
   case Type::NoAllocTrue:
   case Type::NoLockTrue:
     // nolock/noalloc can't be removed in a redeclaration
@@ -4999,7 +4999,7 @@ bool FunctionEffect::diagnoseMethodOverride(bool Adding,
                                             FunctionEffectSet OldFX,
                                             const CXXMethodDecl &NewMethod,
                                             FunctionEffectSet NewFX) const {
-  switch (Type_) {
+  switch (type()) {
   case Type::NoAllocTrue:
   case Type::NoLockTrue:
     // nolock/noalloc can't be removed from an override
@@ -5011,21 +5011,12 @@ bool FunctionEffect::diagnoseMethodOverride(bool Adding,
   return false;
 }
 
-bool FunctionEffect::canInferOnDecl(const Decl *Caller,
-                                    FunctionEffectSet CallerFX) const {
-  switch (Type_) {
+bool FunctionEffect::canInferOnFunction(const TypeSourceInfo &FType) const {
+  switch (type()) {
   case Type::NoAllocTrue:
   case Type::NoLockTrue: {
-    // Does the Decl have nolock(false) / noalloc(false) ?
-    QualType QT;
-    if (isa<BlockDecl>(Caller)) {
-      const auto *TSI = cast<BlockDecl>(Caller)->getSignatureAsWritten();
-      QT = TSI->getType();
-    } else if (isa<ValueDecl>(Caller)) {
-      QT = cast<ValueDecl>(Caller)->getType();
-    } else {
-      return false;
-    }
+    // Does the sugar have nolock(false) / noalloc(false) ?
+    QualType QT = FType.getType();
     if (QT->hasAttr(type() == Type::NoLockTrue ? attr::Kind::NoLock
                                                : attr::Kind::NoAlloc)) {
       return false;
@@ -5040,13 +5031,9 @@ bool FunctionEffect::canInferOnDecl(const Decl *Caller,
   return false;
 }
 
-// TODO: Notice that we don't care about some of the parameters. Is the
-// interface overly general?
-bool FunctionEffect::diagnoseFunctionCall(bool Direct, const Decl *Caller,
-                                          FunctionEffectSet CallerFX,
-                                          CalleeDeclOrType Callee,
+bool FunctionEffect::diagnoseFunctionCall(bool Direct,
                                           FunctionEffectSet CalleeFX) const {
-  switch (Type_) {
+  switch (type()) {
   case Type::NoAllocTrue:
   case Type::NoLockTrue: {
     const Type CallerType = type();
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index ce7b91d4a5e59e..68d8133254fb03 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2596,21 +2596,28 @@ class PendingFunctionAnalysis {
   std::unique_ptr<SmallVector<DirectCall>> UnverifiedDirectCalls;
 
 public:
-  PendingFunctionAnalysis(ASTContext &Ctx, const CallableInfo &cinfo,
+  PendingFunctionAnalysis(ASTContext &Ctx, const CallableInfo &CInfo,
                           FunctionEffectSet AllInferrableEffectsToVerify) {
-    MutableFunctionEffectSet fx;
-    for (const auto &effect : cinfo.Effects) {
-      if (effect.flags() & FunctionEffect::FE_RequiresVerification) {
-        fx.insert(effect);
+    MutableFunctionEffectSet FX;
+    for (const auto &Effect : CInfo.Effects) {
+      if (Effect.flags() & FunctionEffect::FE_RequiresVerification) {
+        FX.insert(Effect);
       }
     }
-    DeclaredVerifiableEffects = FunctionEffectSet::create(Ctx, fx);
+    DeclaredVerifiableEffects = FunctionEffectSet::create(Ctx, FX);
 
     // Check for effects we are not allowed to infer
-    fx.clear();
+    FX.clear();
+    TypeSourceInfo *TSI = nullptr;
+    if (const auto *DD = dyn_cast<DeclaratorDecl>(CInfo.CDecl)) {
+      TSI = DD->getTypeSourceInfo();
+    } else if (const auto *BD = dyn_cast<BlockDecl>(CInfo.CDecl)) {
+      TSI = BD->getSignatureAsWritten();
+    }
+
     for (const auto &effect : AllInferrableEffectsToVerify) {
-      if (effect.canInferOnDecl(cinfo.CDecl, cinfo.Effects)) {
-        fx.insert(effect);
+      if (TSI && effect.canInferOnFunction(*TSI)) {
+        FX.insert(effect);
       } else {
         // Add a diagnostic for this effect if a caller were to
         // try to infer it.
@@ -2618,12 +2625,12 @@ class PendingFunctionAnalysis {
             InferrableEffectToFirstDiagnostic.getOrInsertDefault(effect);
         diag =
             Diagnostic(effect, DiagnosticID::DeclWithoutConstraintOrInference,
-                       cinfo.CDecl->getLocation());
+                       CInfo.CDecl->getLocation());
       }
     }
-    // fx is now the set of inferrable effects which are not prohibited
+    // FX is now the set of inferrable effects which are not prohibited
     FXToInfer = FunctionEffectSet::create(
-        Ctx, FunctionEffectSet::create(Ctx, fx) - DeclaredVerifiableEffects);
+        Ctx, FunctionEffectSet::create(Ctx, FX) - DeclaredVerifiableEffects);
   }
 
   // Hide the way that diagnostics for explicitly required effects vs. inferred
@@ -2968,9 +2975,8 @@ class Analyzer {
     auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
       const auto Flags = Effect.flags();
       if (Flags & FunctionEffect::FE_VerifyCalls) {
-        const bool diagnose = Effect.diagnoseFunctionCall(
-            DirectCall, Caller.CDecl, Caller.Effects, Callee.CDecl,
-            CalleeEffects);
+        const bool diagnose =
+            Effect.diagnoseFunctionCall(DirectCall, CalleeEffects);
         if (diagnose) {
           // If inference is not allowed, or the target is indirect (virtual
           // method/function ptr?), generate a diagnostic now.
@@ -3269,8 +3275,7 @@ class Analyzer {
         if (Effect.flags() & FunctionEffect::FE_VerifyCalls) {
           if (FPT == nullptr ||
               Effect.diagnoseFunctionCall(
-                  /*direct=*/false, CurrentCaller.CDecl, CurrentCaller.Effects,
-                  FPT, FPT->getFunctionEffects())) {
+                  /*direct=*/false, FPT->getFunctionEffects())) {
             addDiagnosticInner(Inferring, Effect,
                                DiagnosticID::CallsDisallowedExpr,
                                Call->getBeginLoc());

>From ad39599ae7670b9f696ca711a13dc3ed341b7fdc Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Sat, 16 Mar 2024 15:57:48 -0700
Subject: [PATCH 12/40] Don't merge effects back to Old on redeclaration

---
 clang/lib/Sema/SemaDecl.cpp         |  7 +++++--
 clang/test/Sema/attr-nolock-wip.cpp | 30 -----------------------------
 2 files changed, 5 insertions(+), 32 deletions(-)

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 1f167467cad6d1..a9d256f3484704 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3951,10 +3951,13 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
       FD->setType(ModQT);
     };
 
-    applyMergedFX(Old);
+    // TODO: We used to apply the merged set of effects to the old decl.
+    // Now we don't.
+
+    // applyMergedFX(Old);
     applyMergedFX(New);
 
-    OldQType = Old->getType();
+    // OldQType = Old->getType();
     NewQType = New->getType();
   }
 
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
index 16ff464fb8aa08..7fbe75e15e9c4f 100644
--- a/clang/test/Sema/attr-nolock-wip.cpp
+++ b/clang/test/Sema/attr-nolock-wip.cpp
@@ -1,5 +1,4 @@
 // RUN: %clang_cc1 -fsyntax-only -fblocks -verify %s
-// R UN: %clang_cc1 -fsyntax-only -fblocks -verify -x c -std=c23 %s
 
 #if !__has_attribute(clang_nolock)
 #error "the 'nolock' attribute is not available"
@@ -7,35 +6,6 @@
 
 // ============================================================================
 
-#if 1 // C function type problems
-void unannotated();
-void nolock() [[clang::nolock]];
-void noalloc() [[clang::noalloc]];
-
-
-void type_conversions()
-{
-	// It's fine to remove a performance constraint.
-	void (*fp_plain)();
-
-	fp_plain = unannotated;
-	fp_plain = nolock;
-	fp_plain = noalloc;
-
-	// Adding/spoofing nolock is unsafe.
-	void (*fp_nolock)() [[clang::nolock]];
-	fp_nolock = nolock;
-	fp_nolock = unannotated; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
-	fp_nolock = noalloc; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
-
-	// Adding/spoofing noalloc is unsafe.
-	void (*fp_noalloc)() [[clang::noalloc]];
-	fp_noalloc = noalloc;
-	fp_noalloc = nolock; // no warning because nolock includes noalloc fp_noalloc = unannotated;
-	fp_noalloc = unannotated; // expected-warning {{attribute 'noalloc' should not be added via type conversion}}
-}
-#endif
-
 // ============================================================================
 
 #if 0

>From 513c88ca9e2b9b87c269ffa6a3f716daeda49cf0 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Sun, 17 Mar 2024 10:46:26 -0700
Subject: [PATCH 13/40] Fix: canInferOnFunction can't always get a
 TypeSourceInfo. Fix test involving redeclarations. Turn off debug logging
 spew.

---
 clang/include/clang/AST/Type.h           | 10 ++--
 clang/lib/AST/Type.cpp                   |  3 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp | 67 +++++++++++++++---------
 clang/test/Sema/attr-nolock-sema.cpp     | 17 ++++--
 4 files changed, 61 insertions(+), 36 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 4da97c88a2257d..2b559b1cc4372c 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4282,10 +4282,12 @@ class FunctionEffect {
 
   /// Return true if the effect is allowed to be inferred on a Decl of the
   /// specified type (generally a FunctionProtoType but TypeSourceInfo is
-  /// provided so any AttributedType sugar can be examined). Only used if the
-  /// effect has FE_InferrableOnCallees flag set. Example: This allows
-  /// nolock(false) to prevent inference for the function.
-  bool canInferOnFunction(const TypeSourceInfo &FType) const;
+  /// provided so any AttributedType sugar can be examined). TSI can be null
+  /// on an implicit function like a default constructor.
+  ///
+  /// This is only used if the effect has FE_InferrableOnCallees flag set. 
+  /// Example: This allows nolock(false) to prevent inference for the function.
+  bool canInferOnFunction(QualType QT, const TypeSourceInfo *FType) const;
 
   // Called if FE_VerifyCalls flag is set; return false for success. When true
   // is returned for a direct call, then the FE_InferrableOnCallees flag may
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index e459833bb05150..98983cc192d759 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5011,12 +5011,11 @@ bool FunctionEffect::diagnoseMethodOverride(bool Adding,
   return false;
 }
 
-bool FunctionEffect::canInferOnFunction(const TypeSourceInfo &FType) const {
+bool FunctionEffect::canInferOnFunction(QualType QT, const TypeSourceInfo *FType) const {
   switch (type()) {
   case Type::NoAllocTrue:
   case Type::NoLockTrue: {
     // Does the sugar have nolock(false) / noalloc(false) ?
-    QualType QT = FType.getType();
     if (QT->hasAttr(type() == Type::NoLockTrue ? attr::Kind::NoLock
                                                : attr::Kind::NoAlloc)) {
       return false;
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 68d8133254fb03..74b6c7e5c99781 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2451,6 +2451,7 @@ struct CallableInfo {
   SpecialFuncType FuncType = SpecialFuncType::None;
   FunctionEffectSet Effects;
   CallType CType = CallType::Unknown;
+  QualType QT;
 
   CallableInfo(const Decl &CD, SpecialFuncType FT = SpecialFuncType::None)
       : CDecl(&CD), FuncType(FT) {
@@ -2468,13 +2469,16 @@ struct CallableInfo {
           CType = CallType::Virtual;
         }
       }
+      QT = FD->getType();
       Effects = FD->getFunctionEffects();
     } else if (auto *BD = dyn_cast<BlockDecl>(CDecl)) {
       CType = CallType::Block;
+      QT = BD->getSignatureAsWritten()->getType();
       Effects = BD->getFunctionEffects();
     } else if (auto *VD = dyn_cast<ValueDecl>(CDecl)) {
       // ValueDecl is function, enum, or variable, so just look at the type.
-      Effects = FunctionEffectSet::get(*VD->getType());
+      QT = VD->getType();
+      Effects = FunctionEffectSet::get(*QT);
     }
   }
 
@@ -2596,8 +2600,9 @@ class PendingFunctionAnalysis {
   std::unique_ptr<SmallVector<DirectCall>> UnverifiedDirectCalls;
 
 public:
-  PendingFunctionAnalysis(ASTContext &Ctx, const CallableInfo &CInfo,
+  PendingFunctionAnalysis(Sema &Sem, const CallableInfo &CInfo,
                           FunctionEffectSet AllInferrableEffectsToVerify) {
+    ASTContext &Ctx = Sem.getASTContext();
     MutableFunctionEffectSet FX;
     for (const auto &Effect : CInfo.Effects) {
       if (Effect.flags() & FunctionEffect::FE_RequiresVerification) {
@@ -2614,9 +2619,11 @@ class PendingFunctionAnalysis {
     } else if (const auto *BD = dyn_cast<BlockDecl>(CInfo.CDecl)) {
       TSI = BD->getSignatureAsWritten();
     }
+    // N.B. TSI can be null for things like an implicit constructor (despite
+    // having a valid QualifiedType).
 
     for (const auto &effect : AllInferrableEffectsToVerify) {
-      if (TSI && effect.canInferOnFunction(*TSI)) {
+      if (effect.canInferOnFunction(CInfo.QT, TSI)) {
         FX.insert(effect);
       } else {
         // Add a diagnostic for this effect if a caller were to
@@ -2745,7 +2752,7 @@ class CompleteFunctionAnalysis {
 
 // ==========
 class Analyzer {
-  constexpr static int kDebugLogLevel = 3;
+  constexpr static int DebugLogLevel = 0;
 
   // --
   Sema &Sem;
@@ -2820,9 +2827,11 @@ class Analyzer {
       }
       AllInferrableEffectsToVerify =
           FunctionEffectSet::create(Sem.getASTContext(), inferrableEffects);
-      llvm::outs() << "AllInferrableEffectsToVerify: ";
-      AllInferrableEffectsToVerify.dump(llvm::outs());
-      llvm::outs() << "\n";
+      if constexpr (DebugLogLevel > 0) {
+        llvm::outs() << "AllInferrableEffectsToVerify: ";
+        AllInferrableEffectsToVerify.dump(llvm::outs());
+        llvm::outs() << "\n";
+      }
     }
 
     SmallVector<const Decl *> &verifyQueue = Sem.DeclsWithUnverifiedEffects;
@@ -2893,11 +2902,13 @@ class Analyzer {
     // Build a PendingFunctionAnalysis on the stack. If it turns out to be
     // complete, we'll have avoided a heap allocation; if it's incomplete, it's
     // a fairly trivial move to a heap-allocated object.
-    PendingFunctionAnalysis FAnalysis(Sem.getASTContext(), CInfo,
+    PendingFunctionAnalysis FAnalysis(Sem, CInfo,
                                       AllInferrableEffectsToVerify);
 
-    llvm::outs() << "\nVerifying " << CInfo.name(Sem) << " ";
-    FAnalysis.dump(llvm::outs());
+    if constexpr (DebugLogLevel > 0) {
+      llvm::outs() << "\nVerifying " << CInfo.name(Sem) << " ";
+      FAnalysis.dump(llvm::outs());
+    }
 
     FunctionBodyASTVisitor Visitor(*this, FAnalysis, CInfo);
 
@@ -2909,8 +2920,10 @@ class Analyzer {
     // Copy the pending analysis to the heap and save it in the map.
     auto *PendingPtr = new PendingFunctionAnalysis(std::move(FAnalysis));
     DeclAnalysis[D] = PendingPtr;
-    llvm::outs() << "inserted pending " << PendingPtr << "\n";
-    DeclAnalysis.dump(Sem, llvm::outs());
+    if constexpr (DebugLogLevel > 0) {
+      llvm::outs() << "inserted pending " << PendingPtr << "\n";
+      DeclAnalysis.dump(Sem, llvm::outs());
+    }
     return PendingPtr;
   }
 
@@ -2925,8 +2938,10 @@ class Analyzer {
         Sem.getASTContext(), Pending, CInfo.Effects,
         AllInferrableEffectsToVerify);
     DeclAnalysis[CInfo.CDecl] = CompletePtr;
-    llvm::outs() << "inserted complete " << CompletePtr << "\n";
-    DeclAnalysis.dump(Sem, llvm::outs());
+    if constexpr (DebugLogLevel > 0) {
+      llvm::outs() << "inserted complete " << CompletePtr << "\n";
+      DeclAnalysis.dump(Sem, llvm::outs());
+    }
   }
 
   // Called after all direct calls requiring inference have been found -- or
@@ -2941,7 +2956,6 @@ class Analyzer {
     }
     completeAnalysis(Caller, *Pending);
     delete Pending;
-    llvm::outs() << "destroyed pending " << Pending << "\n";
   }
 
   // Here we have a call to a Decl, either explicitly via a CallExpr or some
@@ -2965,12 +2979,13 @@ class Analyzer {
     if (!Callee.isVerifiable()) {
       IsInferencePossible = false;
     }
-    llvm::outs() << "followCall from " << Caller.name(Sem) << " to "
-                 << Callee.name(Sem)
-                 << "; verifiable: " << Callee.isVerifiable() << "; callee ";
-    CalleeEffects.dump(llvm::outs());
-    llvm::outs() << "\n";
-    puts("");
+    if constexpr (DebugLogLevel > 0) {
+      llvm::outs() << "followCall from " << Caller.name(Sem) << " to "
+                  << Callee.name(Sem)
+                  << "; verifiable: " << Callee.isVerifiable() << "; callee ";
+      CalleeEffects.dump(llvm::outs());
+      llvm::outs() << "\n";
+    }
 
     auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
       const auto Flags = Effect.flags();
@@ -3359,7 +3374,7 @@ class Analyzer {
     }
 
     bool VisitCallExpr(CallExpr *Call) {
-      if constexpr (kDebugLogLevel > 2) {
+      if constexpr (DebugLogLevel > 2) {
         llvm::errs() << "VisitCallExpr : "
                      << Call->getBeginLoc().printToString(Outer.Sem.SourceMgr)
                      << "\n";
@@ -3393,7 +3408,7 @@ class Analyzer {
     }
 
     bool VisitVarDecl(VarDecl *Var) {
-      if constexpr (kDebugLogLevel > 2) {
+      if constexpr (DebugLogLevel > 2) {
         llvm::errs() << "VisitVarDecl : "
                      << Var->getBeginLoc().printToString(Outer.Sem.SourceMgr)
                      << "\n";
@@ -3452,7 +3467,7 @@ class Analyzer {
     }
 
     bool VisitCXXConstructExpr(CXXConstructExpr *Construct) {
-      if constexpr (kDebugLogLevel > 2) {
+      if constexpr (DebugLogLevel > 2) {
         llvm::errs() << "VisitCXXConstructExpr : "
                      << Construct->getBeginLoc().printToString(
                             Outer.Sem.SourceMgr)
@@ -3591,8 +3606,8 @@ class Analyzer {
 
     CallableFinderCallback::get(Sem, TU);
 
-    /*if (decls.size() != Sem.DeclsWithUnverifiedEffects.size())*/ {
-      llvm::errs() << "\nFXAnalysis: Sem gathered " << decls.size()
+    if constexpr (DebugLogLevel > 0) {
+      llvm::errs() << "\nFXAnalysis: Sema gathered " << decls.size()
                    << " Decls; second AST pass found "
                    << Sem.DeclsWithUnverifiedEffects.size() << "\n";
     }
diff --git a/clang/test/Sema/attr-nolock-sema.cpp b/clang/test/Sema/attr-nolock-sema.cpp
index 99f6242e4747c9..b0b720792d36a4 100644
--- a/clang/test/Sema/attr-nolock-sema.cpp
+++ b/clang/test/Sema/attr-nolock-sema.cpp
@@ -75,13 +75,22 @@ struct Derived : public Base {
 #endif // __cplusplus
 
 // --- REDECLARATIONS ---
+// TODO: These are now errors in C++, but not in C
 
+#ifdef __cplusplus
+int f2(int); // expected-note {{previous declaration is here}}
+int f2(int) [[clang::nolock]]; // expected-error {{conflicting types for 'f2'}}
+#endif // __cplusplus
+
+
+#if 0
 int f2();
 // redeclaration with a stronger constraint is OK.
-int f2() [[clang::nolock]]; // expected-note {{previous declaration is here}}
-int f2() { return 42; } // expected-warning {{attribute 'nolock' on function does not match previous declaration}}
+int f2() [[clang::nolock]]; // e xpected-note {{previous declaration is here}}
+int f2() { return 42; } // e xpected-warning {{attribute 'nolock' on function does not match previous declaration}}
 
 int f3();
 // redeclaration with a stronger constraint is OK.
-int f3() [[clang::noalloc]]; // expected-note {{previous declaration is here}}
-int f3() { return 42; } // expected-warning {{attribute 'noalloc' on function does not match previous declaration}}
+int f3() [[clang::noalloc]]; // e xpected-note {{previous declaration is here}}
+int f3() { return 42; } // e xpected-warning {{attribute 'noalloc' on function does not match previous declaration}}
+#endif

>From 13254292d0e3e97d4ee16989d50fa0dacbcb8800 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 19 Mar 2024 08:45:14 -0700
Subject: [PATCH 14/40] Cleanup of redeclarations (Sema::MergeFunctionDecl) so
 that the type checks never fail. FunctionDecl::getFunctionEffects() now
 returns the union of effects present across all redeclarations.

---
 clang/include/clang/AST/Decl.h              |  7 +---
 clang/include/clang/AST/Type.h              |  2 +-
 clang/lib/AST/Decl.cpp                      | 12 ++++++
 clang/lib/AST/Type.cpp                      |  3 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp    | 14 ++++---
 clang/lib/Sema/SemaDecl.cpp                 | 42 ++++++++++-----------
 clang/test/Sema/attr-nolock-constraints.cpp |  7 ++++
 clang/test/Sema/attr-nolock-sema.cpp        | 26 +++++++++++--
 clang/test/Sema/attr-nolock-wip.cpp         |  4 ++
 9 files changed, 78 insertions(+), 39 deletions(-)

diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index 0460f30ce8a8b4..acff3dee7051dc 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -3008,12 +3008,7 @@ class FunctionDecl : public DeclaratorDecl,
   /// computed and stored.
   unsigned getODRHash() const;
 
-  FunctionEffectSet getFunctionEffects() const {
-    const auto *FPT = getType()->getAs<FunctionProtoType>();
-    if (FPT)
-      return FPT->getFunctionEffects();
-    return {};
-  }
+  FunctionEffectSet getFunctionEffects() const;
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 2b559b1cc4372c..298029cef7195f 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4285,7 +4285,7 @@ class FunctionEffect {
   /// provided so any AttributedType sugar can be examined). TSI can be null
   /// on an implicit function like a default constructor.
   ///
-  /// This is only used if the effect has FE_InferrableOnCallees flag set. 
+  /// This is only used if the effect has FE_InferrableOnCallees flag set.
   /// Example: This allows nolock(false) to prevent inference for the function.
   bool canInferOnFunction(QualType QT, const TypeSourceInfo *FType) const;
 
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 502c978d5b78e4..84c950bdafc1c3 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -4502,6 +4502,18 @@ unsigned FunctionDecl::getODRHash() {
   return ODRHash;
 }
 
+// Effects may differ between redeclarations, so collect all effects from
+// all redeclarations.
+FunctionEffectSet FunctionDecl::getFunctionEffects() const {
+  MutableFunctionEffectSet FX;
+  for (FunctionDecl *FD : redecls()) {
+    if (const auto *FPT = FD->getType()->getAs<FunctionProtoType>()) {
+      FX |= FPT->getFunctionEffects();
+    }
+  }
+  return FunctionEffectSet::create(getASTContext(), FX);
+}
+
 //===----------------------------------------------------------------------===//
 // FieldDecl Implementation
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 98983cc192d759..bea2272c0cb5f9 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5011,7 +5011,8 @@ bool FunctionEffect::diagnoseMethodOverride(bool Adding,
   return false;
 }
 
-bool FunctionEffect::canInferOnFunction(QualType QT, const TypeSourceInfo *FType) const {
+bool FunctionEffect::canInferOnFunction(QualType QT,
+                                        const TypeSourceInfo *FType) const {
   switch (type()) {
   case Type::NoAllocTrue:
   case Type::NoLockTrue: {
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 74b6c7e5c99781..318e87eb3c57b9 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2458,10 +2458,13 @@ struct CallableInfo {
     // llvm::errs() << "CallableInfo " << name() << "\n";
 
     if (auto *FD = dyn_cast<FunctionDecl>(CDecl)) {
-      assert(FD->getCanonicalDecl() == FD);
       // Use the function's definition, if any.
       if (auto *Def = FD->getDefinition()) {
         CDecl = FD = Def;
+        // is the definition always canonical?
+        assert(FD->getCanonicalDecl() == FD);
+      } else {
+        FD = FD->getCanonicalDecl();
       }
       CType = CallType::Function;
       if (auto *Method = dyn_cast<CXXMethodDecl>(FD)) {
@@ -2902,8 +2905,7 @@ class Analyzer {
     // Build a PendingFunctionAnalysis on the stack. If it turns out to be
     // complete, we'll have avoided a heap allocation; if it's incomplete, it's
     // a fairly trivial move to a heap-allocated object.
-    PendingFunctionAnalysis FAnalysis(Sem, CInfo,
-                                      AllInferrableEffectsToVerify);
+    PendingFunctionAnalysis FAnalysis(Sem, CInfo, AllInferrableEffectsToVerify);
 
     if constexpr (DebugLogLevel > 0) {
       llvm::outs() << "\nVerifying " << CInfo.name(Sem) << " ";
@@ -2981,8 +2983,8 @@ class Analyzer {
     }
     if constexpr (DebugLogLevel > 0) {
       llvm::outs() << "followCall from " << Caller.name(Sem) << " to "
-                  << Callee.name(Sem)
-                  << "; verifiable: " << Callee.isVerifiable() << "; callee ";
+                   << Callee.name(Sem)
+                   << "; verifiable: " << Callee.isVerifiable() << "; callee ";
       CalleeEffects.dump(llvm::outs());
       llvm::outs() << "\n";
     }
@@ -3161,7 +3163,7 @@ class Analyzer {
           case DiagnosticID::HasStaticLocal:
             S.Diag(Diag2.Loc, diag::note_func_effect_has_static_local)
                 << effectName << CalleeName;
-            UNTESTED
+            TESTED
             break;
           case DiagnosticID::AccessesThreadLocal:
             S.Diag(Diag2.Loc, diag::note_func_effect_uses_thread_local)
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index a9d256f3484704..5dc92ea98554a6 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3924,6 +3924,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
 
   const auto OldFX = Old->getFunctionEffects();
   const auto NewFX = New->getFunctionEffects();
+  QualType OldQTypeForComparison = OldQType;
   if (OldFX != NewFX) {
     const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
     for (const auto &Item : Diffs) {
@@ -3936,29 +3937,29 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
         Diag(Old->getLocation(), diag::note_previous_declaration);
       }
     }
+    // Following a warning, we could skip merging effects from the previous
+    // declaration, but that would trigger an additional "conflicting types"
+    // error.
+    if (const auto *NewFPT = NewQType->getAs<FunctionProtoType>()) {
+      auto MergedFX = FunctionEffectSet::getUnion(Context, OldFX, NewFX);
 
-    const auto MergedFX = FunctionEffectSet::getUnion(Context, OldFX, NewFX);
-
-    // Having diagnosed any problems, prevent further errors by applying the
-    // merged set of effects to both declarations.
-    auto applyMergedFX = [&](FunctionDecl *FD) {
-      const auto *FPT = FD->getType()->getAs<FunctionProtoType>();
-      FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
+      FunctionProtoType::ExtProtoInfo EPI = NewFPT->getExtProtoInfo();
       EPI.FunctionEffects = MergedFX;
-      QualType ModQT = Context.getFunctionType(FD->getReturnType(),
-                                               FPT->getParamTypes(), EPI);
-
-      FD->setType(ModQT);
-    };
+      QualType ModQT = Context.getFunctionType(NewFPT->getReturnType(),
+                                               NewFPT->getParamTypes(), EPI);
 
-    // TODO: We used to apply the merged set of effects to the old decl.
-    // Now we don't.
+      New->setType(ModQT);
+      NewQType = New->getType();
 
-    // applyMergedFX(Old);
-    applyMergedFX(New);
-
-    // OldQType = Old->getType();
-    NewQType = New->getType();
+      // Revise OldQTForComparison to include the merged effects,
+      // so as not to fail due to differences later.
+      if (const auto *OldFPT = OldQType->getAs<FunctionProtoType>()) {
+        EPI = OldFPT->getExtProtoInfo();
+        EPI.FunctionEffects = MergedFX;
+        OldQTypeForComparison = Context.getFunctionType(
+            OldFPT->getReturnType(), OldFPT->getParamTypes(), EPI);
+      }
+    }
   }
 
   if (getLangOpts().CPlusPlus) {
@@ -4125,9 +4126,8 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
     // We also want to respect all the extended bits except noreturn.
 
     // noreturn should now match unless the old type info didn't have it.
-    QualType OldQTypeForComparison = OldQType;
     if (!OldTypeInfo.getNoReturn() && NewTypeInfo.getNoReturn()) {
-      auto *OldType = OldQType->castAs<FunctionProtoType>();
+      auto *OldType = OldQTypeForComparison->castAs<FunctionProtoType>();
       const FunctionType *OldTypeForComparison
         = Context.adjustFunctionType(OldType, OldTypeInfo.withNoReturn(true));
       OldQTypeForComparison = QualType(OldTypeForComparison, 0);
diff --git a/clang/test/Sema/attr-nolock-constraints.cpp b/clang/test/Sema/attr-nolock-constraints.cpp
index 801f971b410865..5d1efe931a1f91 100644
--- a/clang/test/Sema/attr-nolock-constraints.cpp
+++ b/clang/test/Sema/attr-nolock-constraints.cpp
@@ -139,3 +139,10 @@ void nl11() [[clang::nolock]]
 {
 	nl11_no_inference(); // expected-warning {{'nolock' function 'nl11' must not call non-'nolock' function 'nl11_no_inference'}}
 }
+
+// Verify that when attached to a redeclaration, the attribute successfully attaches.
+void nl12() {
+	static int x; // expected-warning {{'nolock' function 'nl12' must not have static locals}}
+}
+void nl12() [[clang::nolock]];
+void nl13() [[clang::nolock]] { nl12(); }
diff --git a/clang/test/Sema/attr-nolock-sema.cpp b/clang/test/Sema/attr-nolock-sema.cpp
index b0b720792d36a4..28542be0a2ecd0 100644
--- a/clang/test/Sema/attr-nolock-sema.cpp
+++ b/clang/test/Sema/attr-nolock-sema.cpp
@@ -75,13 +75,31 @@ struct Derived : public Base {
 #endif // __cplusplus
 
 // --- REDECLARATIONS ---
-// TODO: These are now errors in C++, but not in C
 
 #ifdef __cplusplus
-int f2(int); // expected-note {{previous declaration is here}}
-int f2(int) [[clang::nolock]]; // expected-error {{conflicting types for 'f2'}}
-#endif // __cplusplus
+// In C++, the third declaration gets seen as a redeclaration of the second.
+void f2();
+void f2() [[clang::nolock]]; // expected-note {{previous declaration is here}}
+void f2(); // expected-warning {{attribute 'nolock' on function does not match previous declaration}}
+#else
+// In C, the third declaration is redeclaration of the first (?).
+void f2();
+void f2() [[clang::nolock]];
+void f2();
+#endif
+// Note: we verify that the attribute is actually seen during the constraints tests.
+
+
+// Ensure that the redeclaration's attribute is seen and diagnosed correctly.
 
+// void f2() {
+// 	static int x;
+// }
+// void f2() [[clang::nolock]];
+// 
+// void f3() [[clang::nolock]] {
+// 	f2();
+// }
 
 #if 0
 int f2();
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
index 7fbe75e15e9c4f..ab8cf57d69ed0c 100644
--- a/clang/test/Sema/attr-nolock-wip.cpp
+++ b/clang/test/Sema/attr-nolock-wip.cpp
@@ -6,6 +6,10 @@
 
 // ============================================================================
 
+void f2(int);
+void f2(int) [[clang::nolock]]; // expected-note {{previous declaration is here}}
+void f2(int); // expected-warning {{attribute 'nolock' on function does not match previous declaration}}
+
 // ============================================================================
 
 #if 0

>From 5ac74293f4d7e610b60ac8f3bf45438cab840acf Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 19 Mar 2024 13:36:05 -0700
Subject: [PATCH 15/40] FunctionEffectSet::create() is now a method of
 ASTContext; the global uniquing set is now a member of ASTContext.

---
 clang/include/clang/AST/ASTContext.h     | 18 +++++++
 clang/include/clang/AST/Type.h           |  6 +--
 clang/lib/AST/ASTContext.cpp             | 68 ++++++++++++++++++++++++
 clang/lib/AST/Decl.cpp                   |  2 +-
 clang/lib/AST/Type.cpp                   | 67 +----------------------
 clang/lib/Sema/AnalysisBasedWarnings.cpp | 10 ++--
 clang/lib/Sema/SemaType.cpp              |  2 +-
 7 files changed, 96 insertions(+), 77 deletions(-)

diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index ff6b64c7f72d57..8e57d40922440d 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -69,6 +69,8 @@ class DiagnosticsEngine;
 class DynTypedNodeList;
 class Expr;
 enum class FloatModeKind;
+class FunctionEffect;
+class FunctionEffectSet;
 class GlobalDecl;
 class IdentifierTable;
 class LangOptions;
@@ -459,6 +461,16 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// This is the top-level (C++20) Named module we are building.
   Module *CurrentCXXNamedModule = nullptr;
 
+  class FunctionEffectSetUniquing {
+    llvm::DenseSet<llvm::ArrayRef<const FunctionEffect>> Set;
+
+  public:
+    FunctionEffectSet getUniqued(llvm::ArrayRef<const FunctionEffect> FX);
+
+    ~FunctionEffectSetUniquing();
+  };
+  FunctionEffectSetUniquing UniquedFunctionEffectSet;
+
   static constexpr unsigned ConstantArrayTypesLog2InitSize = 8;
   static constexpr unsigned GeneralTypesLog2InitSize = 9;
   static constexpr unsigned FunctionProtoTypesLog2InitSize = 12;
@@ -1065,6 +1077,12 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// Get module under construction, nullptr if this is not a C++20 module.
   Module *getCurrentNamedModule() const { return CurrentCXXNamedModule; }
 
+  /// Get or create a uniqued, immutable FunctionEffectSet.
+  FunctionEffectSet
+  getUniquedFunctionEffectSet(llvm::ArrayRef<const FunctionEffect> FX) {
+    return UniquedFunctionEffectSet.getUniqued(FX);
+  }
+
   TranslationUnitDecl *getTranslationUnitDecl() const {
     return TUDecl->getMostRecentDecl();
   }
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 298029cef7195f..508736ebe4ea05 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4333,6 +4333,8 @@ class MutableFunctionEffectSet : public SmallVector<FunctionEffect, 4> {
 // sorted spans, which are compatible with the STL set algorithms.
 class FunctionEffectSet {
 private:
+  friend class ASTContext; // so it can call the private constructor
+
   explicit FunctionEffectSet(llvm::ArrayRef<const FunctionEffect> Array)
       : Impl(Array) {}
 
@@ -4368,10 +4370,6 @@ class FunctionEffectSet {
 
   void dump(llvm::raw_ostream &OS) const;
 
-  /// Factory function: returns instances with uniqued implementations.
-  static FunctionEffectSet create(ASTContext &C,
-                                  const MutableFunctionEffectSet &FX);
-
   /// Intersection.
   MutableFunctionEffectSet operator&(const FunctionEffectSet &RHS) const;
   /// Difference.
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 3e2142469babd5..6dd511be275c35 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -13702,3 +13702,71 @@ StringRef ASTContext::getCUIDHash() const {
   CUIDHash = llvm::utohexstr(llvm::MD5Hash(LangOpts.CUID), /*LowerCase=*/true);
   return CUIDHash;
 }
+
+using FunctionEffectSpan = llvm::ArrayRef<const FunctionEffect>;
+
+llvm::hash_code hash_value(const FunctionEffect &Effect) {
+  return Effect.opaqueRepr();
+}
+
+namespace llvm {
+template <> struct DenseMapInfo<FunctionEffectSpan> {
+  static FunctionEffectSpan getEmptyKey() {
+    return {static_cast<const FunctionEffect *>(nullptr), size_t(0)};
+  }
+  static FunctionEffectSpan getTombstoneKey() {
+    return {reinterpret_cast<const FunctionEffect *>(intptr_t(-1)), size_t(0)};
+  }
+  static unsigned getHashValue(const FunctionEffectSpan &Val) {
+    hash_code hash1 = hash_value(Val.size());
+    // Treat the FunctionEffects as a span of integers
+    const FunctionEffect *Begin = Val.begin();
+    const FunctionEffect *End = Val.end();
+    hash_code hash2 =
+        hash_combine_range(reinterpret_cast<const uint32_t *>(Begin),
+                           reinterpret_cast<const uint32_t *>(End));
+    return hash_combine(hash1, hash2);
+  }
+  static bool isEqual(const FunctionEffectSpan &LHS,
+                      const FunctionEffectSpan &RHS) {
+    if (LHS.size() != RHS.size()) {
+      return false;
+    }
+    // distinguish empty from tombstone
+    if (LHS.size() == 0) {
+      return LHS.data() == RHS.data();
+    }
+    return std::equal(LHS.begin(), LHS.end(), RHS.begin());
+  }
+};
+} // namespace llvm
+
+FunctionEffectSet ASTContext::FunctionEffectSetUniquing::getUniqued(
+    llvm::ArrayRef<const FunctionEffect> FX) {
+  if (FX.empty()) {
+    return {};
+  }
+
+  // Do we already have the incoming set?
+  const auto Iter = Set.find_as(FX);
+  if (Iter != Set.end()) {
+    return FunctionEffectSet(*Iter);
+  }
+
+  // Copy the incoming array to permanent storage.
+  FunctionEffect *Storage = new FunctionEffect[FX.size()];
+  std::copy(FX.begin(), FX.end(), Storage);
+
+  // Make a new wrapper and insert it into the set.
+  llvm::ArrayRef<const FunctionEffect> Arr(Storage, FX.size());
+  auto [InsIter, _] = Set.insert(Arr);
+  return FunctionEffectSet(*InsIter);
+}
+
+ASTContext::FunctionEffectSetUniquing::~FunctionEffectSetUniquing() {
+  for (const auto &ArrRef : Set) {
+    const FunctionEffect *ptrToFX = ArrRef.data();
+    delete[] ptrToFX;
+  }
+  Set.clear();
+}
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 84c950bdafc1c3..981b61931d2538 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -4511,7 +4511,7 @@ FunctionEffectSet FunctionDecl::getFunctionEffects() const {
       FX |= FPT->getFunctionEffects();
     }
   }
-  return FunctionEffectSet::create(getASTContext(), FX);
+  return getASTContext().getUniquedFunctionEffectSet(FX);
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index bea2272c0cb5f9..06f9c0190bad6f 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5076,71 +5076,6 @@ MutableFunctionEffectSet::operator|=(FunctionEffectSet RHS) {
   return *this;
 }
 
-using FunctionEffectSpan = llvm::ArrayRef<const FunctionEffect>;
-
-llvm::hash_code hash_value(const FunctionEffect &Effect) {
-  return Effect.opaqueRepr();
-}
-
-namespace llvm {
-template <> struct DenseMapInfo<FunctionEffectSpan> {
-  static FunctionEffectSpan getEmptyKey() {
-    return {static_cast<const FunctionEffect *>(nullptr), size_t(0)};
-  }
-  static FunctionEffectSpan getTombstoneKey() {
-    return {reinterpret_cast<const FunctionEffect *>(intptr_t(-1)), size_t(0)};
-  }
-  static unsigned getHashValue(const FunctionEffectSpan &Val) {
-    hash_code hash1 = hash_value(Val.size());
-    // Treat the FunctionEffects as a span of integers
-    const FunctionEffect *Begin = Val.begin();
-    const FunctionEffect *End = Val.end();
-    hash_code hash2 =
-        hash_combine_range(reinterpret_cast<const uint32_t *>(Begin),
-                           reinterpret_cast<const uint32_t *>(End));
-    return hash_combine(hash1, hash2);
-  }
-  static bool isEqual(const FunctionEffectSpan &LHS,
-                      const FunctionEffectSpan &RHS) {
-    if (LHS.size() != RHS.size()) {
-      return false;
-    }
-    // distinguish empty from tombstone
-    if (LHS.size() == 0) {
-      return LHS.data() == RHS.data();
-    }
-    return std::equal(LHS.begin(), LHS.end(), RHS.begin());
-  }
-};
-} // namespace llvm
-
-// The ASTContext
-FunctionEffectSet
-FunctionEffectSet::create(ASTContext &C, const MutableFunctionEffectSet &FX) {
-  if (FX.empty()) {
-    return {};
-  }
-
-  // TODO: Put this in the ASTContext
-  // TODO: And destroy the memory
-  static llvm::DenseSet<FunctionEffectSpan> UniquedFXSets;
-
-  // Do we already have the incoming set?
-  const auto Iter = UniquedFXSets.find_as(FX);
-  if (Iter != UniquedFXSets.end()) {
-    return FunctionEffectSet(*Iter);
-  }
-
-  // Copy the incoming array to permanent storage.
-  FunctionEffect *Storage = new FunctionEffect[FX.size()];
-  std::copy(FX.begin(), FX.end(), Storage);
-
-  // Make a new wrapper and insert it into the set.
-  auto [InsIter, _] =
-      UniquedFXSets.insert(FunctionEffectSpan(Storage, FX.size()));
-  return FunctionEffectSet(*InsIter);
-}
-
 FunctionEffectSet FunctionEffectSet::getUnion(ASTContext &C,
                                               const FunctionEffectSet &LHS,
                                               const FunctionEffectSet &RHS) {
@@ -5159,7 +5094,7 @@ FunctionEffectSet FunctionEffectSet::getUnion(ASTContext &C,
   std::set_union(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
                  std::back_inserter(Vec));
   // The result of a set operation is an ordered/unique set.
-  return FunctionEffectSet::create(C, Vec);
+  return C.getUniquedFunctionEffectSet(Vec);
 }
 
 MutableFunctionEffectSet
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 318e87eb3c57b9..47202980232bc6 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2612,7 +2612,7 @@ class PendingFunctionAnalysis {
         FX.insert(Effect);
       }
     }
-    DeclaredVerifiableEffects = FunctionEffectSet::create(Ctx, FX);
+    DeclaredVerifiableEffects = Ctx.getUniquedFunctionEffectSet(FX);
 
     // Check for effects we are not allowed to infer
     FX.clear();
@@ -2639,8 +2639,8 @@ class PendingFunctionAnalysis {
       }
     }
     // FX is now the set of inferrable effects which are not prohibited
-    FXToInfer = FunctionEffectSet::create(
-        Ctx, FunctionEffectSet::create(Ctx, FX) - DeclaredVerifiableEffects);
+    FXToInfer = Ctx.getUniquedFunctionEffectSet(
+        Ctx.getUniquedFunctionEffectSet(FX) - DeclaredVerifiableEffects);
   }
 
   // Hide the way that diagnostics for explicitly required effects vs. inferred
@@ -2722,7 +2722,7 @@ class CompleteFunctionAnalysis {
         verified.insert(effect);
       }
     }
-    VerifiedEffects = FunctionEffectSet::create(Ctx, verified);
+    VerifiedEffects = Ctx.getUniquedFunctionEffectSet(verified);
 
     InferrableEffectToFirstDiagnostic =
         std::move(pending.InferrableEffectToFirstDiagnostic);
@@ -2829,7 +2829,7 @@ class Analyzer {
         }
       }
       AllInferrableEffectsToVerify =
-          FunctionEffectSet::create(Sem.getASTContext(), inferrableEffects);
+          Sem.getASTContext().getUniquedFunctionEffectSet(inferrableEffects);
       if constexpr (DebugLogLevel > 0) {
         llvm::outs() << "AllInferrableEffectsToVerify: ";
         AllInferrableEffectsToVerify.dump(llvm::outs());
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 0fcafeb0172fb4..174ce62b4f5d9c 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8041,7 +8041,7 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
   }
 
   EPI.FunctionEffects =
-      FunctionEffectSet::create(state.getSema().getASTContext(), NewFX);
+      state.getSema().getASTContext().getUniquedFunctionEffectSet(NewFX);
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
                                                FPT->getParamTypes(), EPI);
   type = unwrapped.wrap(S, newtype->getAs<FunctionType>());

>From 81b86dffabad166f37e93e8bec833b103b762c84 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 19 Mar 2024 14:08:05 -0700
Subject: [PATCH 16/40] - Serialize FunctionEffectSet as part of a
 FunctionProtoType. - Rename Sema's DeclsWithUnverifiedEffects ->
 DeclsWithEffectsToVerify. Read and write it in ASTReader/ASTWriter. How to
 test this? - AttrDocs.td - remove trailing whitespace. - Fix hash_value for
 FunctionEffect. - FunctionDecl::getFunctionEffects() can use
 getMostRecentDecl() instead of doing a set operation.

---
 clang/include/clang/AST/ASTContext.h          |  4 ++++
 clang/include/clang/AST/Type.h                |  5 ++++
 clang/include/clang/AST/TypeProperties.td     |  9 ++++----
 clang/include/clang/Basic/AttrDocs.td         |  2 +-
 clang/include/clang/Sema/Sema.h               |  6 ++---
 .../include/clang/Serialization/ASTBitCodes.h |  4 ++++
 clang/include/clang/Serialization/ASTReader.h |  3 +++
 clang/include/clang/Serialization/ASTWriter.h |  1 +
 clang/lib/AST/ASTContext.cpp                  |  9 +++++++-
 clang/lib/AST/Decl.cpp                        | 13 ++++-------
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 14 +++++------
 clang/lib/Sema/SemaDecl.cpp                   |  2 +-
 clang/lib/Serialization/ASTReader.cpp         | 23 +++++++++++++++++++
 clang/lib/Serialization/ASTWriter.cpp         | 12 ++++++++++
 14 files changed, 81 insertions(+), 26 deletions(-)

diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index 8e57d40922440d..95bd2a901e9be9 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -1083,6 +1083,10 @@ class ASTContext : public RefCountedBase<ASTContext> {
     return UniquedFunctionEffectSet.getUniqued(FX);
   }
 
+  /// Get or create a uniqued, immutable FunctionEffectSet from a serialized
+  /// span of uint32_t's.
+  FunctionEffectSet getUniquedFunctionEffectSet(llvm::ArrayRef<uint32_t> FX);
+
   TranslationUnitDecl *getTranslationUnitDecl() const {
     return TUDecl->getMostRecentDecl();
   }
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 508736ebe4ea05..ca4660edb2f56f 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4347,6 +4347,11 @@ class FunctionEffectSet {
   FunctionEffectSet() = default;
 
   const void *getOpaqueValue() const { return Impl.data(); }
+  llvm::ArrayRef<uint32_t> serializable() const {
+    static_assert(sizeof(FunctionEffect) == sizeof(uint32_t));
+    const uint32_t *ptr = reinterpret_cast<const uint32_t *>(Impl.data());
+    return {const_cast<uint32_t *>(ptr), Impl.size()};
+  }
 
   explicit operator bool() const { return !empty(); }
   bool empty() const { return Impl.empty(); }
diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
index 1d5d8f696977e7..3121598761e44f 100644
--- a/clang/include/clang/AST/TypeProperties.td
+++ b/clang/include/clang/AST/TypeProperties.td
@@ -326,10 +326,9 @@ let Class = FunctionProtoType in {
   def : Property<"AArch64SMEAttributes", UInt32> {
     let Read = [{ node->getAArch64SMEAttributes() }];
   }
-  /* TODO: How to serialize FunctionEffect / FunctionEffectSet?
-  def : Property<"functionEffects", FunctionEffectSet> {
-    let Read = [{ node->getFunctionEffects() }];
-  }*/
+  def : Property<"functionEffects", Array<UInt32>> {
+    let Read = [{ node->getFunctionEffects().serializable() }];
+  }
 
   def : Creator<[{
     auto extInfo = FunctionType::ExtInfo(noReturn, hasRegParm, regParm,
@@ -346,7 +345,7 @@ let Class = FunctionProtoType in {
     epi.ExtParameterInfos =
       extParameterInfo.empty() ? nullptr : extParameterInfo.data();
     epi.AArch64SMEAttributes = AArch64SMEAttributes;
-    //epi.FunctionEffects = functionEffects;
+    epi.FunctionEffects = ctx.getUniquedFunctionEffectSet(functionEffects);
     return ctx.getFunctionType(returnType, parameters, epi);
   }]>;
 }
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index bb897c708ebbea..71a35f63ef106a 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -7977,7 +7977,7 @@ requirement:
 def NoLockNoAllocDocs : Documentation {
   let Category = DocCatType;
   let Content = [{
-The ``nolock`` and ``noalloc`` attributes can be attached to functions, blocks, 
+The ``nolock`` and ``noalloc`` attributes can be attached to functions, blocks,
 function pointers, lambdas, and member functions. The attributes identify code
 which must not allocate memory or lock, and the compiler uses the attributes to
 verify these requirements.
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 2772f882a5c09d..b341e2361a5558 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -723,8 +723,8 @@ class Sema final {
 
   /// All functions/lambdas/blocks which have bodies and which have a non-empty
   /// FunctionEffectSet to be verified.
-  SmallVector<const Decl *> DeclsWithUnverifiedEffects;
-  /// The union of all effects present on DeclsWithUnverifiedEffects.
+  SmallVector<const Decl *> DeclsWithEffectsToVerify;
+  /// The union of all effects present on DeclsWithEffectsToVerify.
   MutableFunctionEffectSet AllEffectsToVerify;
 
   /// Determine if VD, which must be a variable or function, is an external
@@ -3142,7 +3142,7 @@ class Sema final {
                               QualType T, TypeSourceInfo *TSInfo,
                               StorageClass SC);
 
-  /// Potentially add a FunctionDecl or BlockDecl to DeclsWithUnverifiedEffects.
+  /// Potentially add a FunctionDecl or BlockDecl to DeclsWithEffectsToVerify.
   void CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX);
 
   // Contexts where using non-trivial C union types can be disallowed. This is
diff --git a/clang/include/clang/Serialization/ASTBitCodes.h b/clang/include/clang/Serialization/ASTBitCodes.h
index f31efa5117f0d1..a2d620280e14ad 100644
--- a/clang/include/clang/Serialization/ASTBitCodes.h
+++ b/clang/include/clang/Serialization/ASTBitCodes.h
@@ -698,6 +698,10 @@ enum ASTRecordTypes {
   /// Record code for an unterminated \#pragma clang assume_nonnull begin
   /// recorded in a preamble.
   PP_ASSUME_NONNULL_LOC = 67,
+
+  /// Record code for Sema's vector of functions/blocks with effects to
+  /// be verified.
+  DECLS_WITH_EFFECTS_TO_VERIFY = 68
 };
 
 /// Record types used within a source manager block.
diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
index 370d8037a4da17..c34a7482b9a688 100644
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -942,6 +942,9 @@ class ASTReader
   /// Sema tracks these to emit deferred diags.
   llvm::SmallSetVector<serialization::DeclID, 4> DeclsToCheckForDeferredDiags;
 
+  /// The IDs of all decls with function effects to be checked.
+  SmallVector<serialization::DeclID> DeclsWithEffectsToVerify;
+
 private:
   struct ImportedSubmodule {
     serialization::SubmoduleID ID;
diff --git a/clang/include/clang/Serialization/ASTWriter.h b/clang/include/clang/Serialization/ASTWriter.h
index e5db486a71a490..56e309e557d1ac 100644
--- a/clang/include/clang/Serialization/ASTWriter.h
+++ b/clang/include/clang/Serialization/ASTWriter.h
@@ -554,6 +554,7 @@ class ASTWriter : public ASTDeserializationListener,
   void WriteMSPointersToMembersPragmaOptions(Sema &SemaRef);
   void WritePackPragmaOptions(Sema &SemaRef);
   void WriteFloatControlPragmaOptions(Sema &SemaRef);
+  void WriteDeclsWithEffectsToVerify(Sema &SemaRef);
   void WriteModuleFileExtension(Sema &SemaRef,
                                 ModuleFileExtensionWriter &Writer);
 
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 6dd511be275c35..cf6a1882aea5ab 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -13706,7 +13706,7 @@ StringRef ASTContext::getCUIDHash() const {
 using FunctionEffectSpan = llvm::ArrayRef<const FunctionEffect>;
 
 llvm::hash_code hash_value(const FunctionEffect &Effect) {
-  return Effect.opaqueRepr();
+  return llvm::hash_value(Effect.opaqueRepr());
 }
 
 namespace llvm {
@@ -13741,6 +13741,13 @@ template <> struct DenseMapInfo<FunctionEffectSpan> {
 };
 } // namespace llvm
 
+FunctionEffectSet
+ASTContext::getUniquedFunctionEffectSet(llvm::ArrayRef<uint32_t> FX) {
+  static_assert(sizeof(FunctionEffect) == sizeof(uint32_t));
+  const auto *ptr = reinterpret_cast<const FunctionEffect *>(FX.data());
+  return UniquedFunctionEffectSet.getUniqued({ptr, FX.size()});
+}
+
 FunctionEffectSet ASTContext::FunctionEffectSetUniquing::getUniqued(
     llvm::ArrayRef<const FunctionEffect> FX) {
   if (FX.empty()) {
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 981b61931d2538..827d57e07d6037 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -4502,16 +4502,13 @@ unsigned FunctionDecl::getODRHash() {
   return ODRHash;
 }
 
-// Effects may differ between redeclarations, so collect all effects from
-// all redeclarations.
+// Effects may differ between declarations, but they should be propagated from old
+// to new on any redeclaration, so it suffices to look at getMostRecentDecl().
 FunctionEffectSet FunctionDecl::getFunctionEffects() const {
-  MutableFunctionEffectSet FX;
-  for (FunctionDecl *FD : redecls()) {
-    if (const auto *FPT = FD->getType()->getAs<FunctionProtoType>()) {
-      FX |= FPT->getFunctionEffects();
-    }
+  if (const auto *FPT = getMostRecentDecl()->getType()->getAs<FunctionProtoType>()) {
+    return FPT->getFunctionEffects();
   }
-  return getASTContext().getUniquedFunctionEffectSet(FX);
+  return {};
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 47202980232bc6..5903b792bfe1e8 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2761,7 +2761,7 @@ class Analyzer {
   Sema &Sem;
 
   // used from Sema:
-  //  SmallVector<const Decl *> DeclsWithUnverifiedEffects
+  //  SmallVector<const Decl *> DeclsWithEffectsToVerify
 
   // Subset of Sema.AllEffectsToVerify
   FunctionEffectSet AllInferrableEffectsToVerify;
@@ -2837,9 +2837,9 @@ class Analyzer {
       }
     }
 
-    SmallVector<const Decl *> &verifyQueue = Sem.DeclsWithUnverifiedEffects;
+    SmallVector<const Decl *> &verifyQueue = Sem.DeclsWithEffectsToVerify;
 
-    // It's helpful to use DeclsWithUnverifiedEffects as a stack for a
+    // It's helpful to use DeclsWithEffectsToVerify as a stack for a
     // depth-first traversal rather than have a secondary container. But first,
     // reverse it, so Decls are verified in the order they are declared.
     std::reverse(verifyQueue.begin(), verifyQueue.end());
@@ -3545,7 +3545,7 @@ class Analyzer {
   };
 
 #if FX_ANALYZER_VERIFY_DECL_LIST
-  // Sema has accumulated DeclsWithUnverifiedEffects. As a debug check, do our
+  // Sema has accumulated DeclsWithEffectsToVerify. As a debug check, do our
   // own AST traversal and see what we find.
 
   using MatchFinder = ast_matchers::MatchFinder;
@@ -3603,15 +3603,15 @@ class Analyzer {
   void verifyRootDecls(const TranslationUnitDecl &TU) const {
     // If this weren't debug code, it would be good to find a way to move/swap
     // instead of copying.
-    SmallVector<const Decl *> decls = Sem.DeclsWithUnverifiedEffects;
-    Sem.DeclsWithUnverifiedEffects.clear();
+    SmallVector<const Decl *> decls = Sem.DeclsWithEffectsToVerify;
+    Sem.DeclsWithEffectsToVerify.clear();
 
     CallableFinderCallback::get(Sem, TU);
 
     if constexpr (DebugLogLevel > 0) {
       llvm::errs() << "\nFXAnalysis: Sema gathered " << decls.size()
                    << " Decls; second AST pass found "
-                   << Sem.DeclsWithUnverifiedEffects.size() << "\n";
+                   << Sem.DeclsWithEffectsToVerify.size() << "\n";
     }
   }
 #endif
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 5dc92ea98554a6..aecd9b3f52a625 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11179,7 +11179,7 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
   }
 
   // Record the declaration for later analysis.
-  DeclsWithUnverifiedEffects.push_back(D);
+  DeclsWithEffectsToVerify.push_back(D);
 }
 
 /// Determines if we can perform a correct type check for \p D as a
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index ede9f6e93469b7..3810c1d75cff0c 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3838,6 +3838,11 @@ llvm::Error ASTReader::ReadASTBlock(ModuleFile &F,
       FPPragmaOptions.swap(Record);
       break;
 
+    case DECLS_WITH_EFFECTS_TO_VERIFY:
+      for (unsigned I = 0, N = Record.size(); I != N; ++I)
+        DeclsWithEffectsToVerify.push_back(getGlobalDeclID(F, Record[I]));
+      break;
+
     case OPENCL_EXTENSIONS:
       for (unsigned I = 0, E = Record.size(); I != E; ) {
         auto Name = ReadString(Record, I);
@@ -8208,6 +8213,24 @@ void ASTReader::InitializeSema(Sema &S) {
         NewOverrides.applyOverrides(SemaObj->getLangOpts());
   }
 
+  if (!DeclsWithEffectsToVerify.empty()) {
+    for (uint64_t ID : DeclsWithEffectsToVerify) {
+      Decl *D = GetDecl(ID);
+      SemaObj->DeclsWithEffectsToVerify.push_back(D);
+
+      FunctionEffectSet FX;
+      if (auto *FD = dyn_cast<FunctionDecl>(D)) {
+        FX = FD->getFunctionEffects();
+      } else if (auto *BD = dyn_cast<BlockDecl>(D)) {
+        FX = BD->getFunctionEffects();
+      }
+      if (FX) {
+        SemaObj->AllEffectsToVerify |= FX;
+      }
+    }
+    DeclsWithEffectsToVerify.clear();
+  }
+
   SemaObj->OpenCLFeatures = OpenCLExtensions;
 
   UpdateSema();
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 3653d94c6e0739..731a58ee785703 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -4429,6 +4429,17 @@ void ASTWriter::WriteFloatControlPragmaOptions(Sema &SemaRef) {
   Stream.EmitRecord(FLOAT_CONTROL_PRAGMA_OPTIONS, Record);
 }
 
+/// Write Sema's collected list of declarations with unverified effects.
+void ASTWriter::WriteDeclsWithEffectsToVerify(Sema &SemaRef) {
+  if (SemaRef.DeclsWithEffectsToVerify.empty())
+    return;
+  RecordData Record;
+  for (const auto *D : SemaRef.DeclsWithEffectsToVerify) {
+    AddDeclRef(D, Record);
+  }
+  Stream.EmitRecord(DECLS_WITH_EFFECTS_TO_VERIFY, Record);
+}
+
 void ASTWriter::WriteModuleFileExtension(Sema &SemaRef,
                                          ModuleFileExtensionWriter &Writer) {
   // Enter the extension block.
@@ -5287,6 +5298,7 @@ ASTFileSignature ASTWriter::WriteASTCore(Sema &SemaRef, StringRef isysroot,
   }
   WritePackPragmaOptions(SemaRef);
   WriteFloatControlPragmaOptions(SemaRef);
+  WriteDeclsWithEffectsToVerify(SemaRef);
 
   // Some simple statistics
   RecordData::value_type Record[] = {

>From 8414186c5d6819c805ba521f06ab73e0d6b085e9 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 20 Mar 2024 12:02:13 -0700
Subject: [PATCH 17/40] Don't repeat function names in diagnostics.

---
 .../clang/Basic/DiagnosticSemaKinds.td        | 34 ++++++-------
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 39 +++++++--------
 clang/test/Sema/attr-nolock-constraints.cpp   | 48 +++++++++----------
 3 files changed, 59 insertions(+), 62 deletions(-)

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index df553a47a8dbe7..f50a572fe7f5e2 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10779,63 +10779,63 @@ def warn_imp_cast_drops_unaligned : Warning<
   InGroup<DiagGroup<"unaligned-qualifier-implicit-cast">>;
 
 def warn_func_effect_allocates : Warning<
-  "'%0' function '%1' must not allocate or deallocate memory">,
+  "'%0' function must not allocate or deallocate memory">,
   InGroup<FunctionEffects>;
 
 def note_func_effect_allocates : Note<
-  "'%1' cannot be inferred '%0' because it allocates/deallocates memory">;
+  "function cannot be inferred '%0' because it allocates/deallocates memory">;
 
 def warn_func_effect_throws_or_catches : Warning<
-  "'%0' function '%1' must not throw or catch exceptions">,
+  "'%0' function must not throw or catch exceptions">,
   InGroup<FunctionEffects>;
 
 def note_func_effect_throws_or_catches : Note<
-  "'%1' cannot be inferred '%0' because it throws or catches exceptions">;
+  "function cannot be inferred '%0' because it throws or catches exceptions">;
 
 def warn_func_effect_has_static_local : Warning<
-  "'%0' function '%1' must not have static locals">,
+  "'%0' function must not have static locals">,
   InGroup<FunctionEffects>;
 
 def note_func_effect_has_static_local : Note<
-  "'%1' cannot be inferred '%0' because it has a static local">;
+  "function cannot be inferred '%0' because it has a static local">;
 
 def warn_func_effect_uses_thread_local : Warning<
-  "'%0' function '%1' must not use thread-local variables">,
+  "'%0' function must not use thread-local variables">,
   InGroup<FunctionEffects>;
 
 def note_func_effect_uses_thread_local : Note<
-  "'%1' cannot be inferred '%0' because it uses a thread-local variable">;
+  "function cannot be inferred '%0' because it uses a thread-local variable">;
 
 def warn_func_effect_calls_objc : Warning<
-  "'%0' function '%1' must not access an ObjC method or property">,
+  "'%0' function must not access an ObjC method or property">,
   InGroup<FunctionEffects>;
 
 def note_func_effect_calls_objc : Note<
-  "'%1' cannot be inferred '%0' because it accesses an ObjC method or property">;
+  "function cannot be inferred '%0' because it accesses an ObjC method or property">;
 
 def warn_func_effect_calls_disallowed_func : Warning<
-  "'%0' function '%1' must not call non-'%0' function '%2'">,
+  "'%0' function must not call non-'%0' function">,
   InGroup<FunctionEffects>;
 
 // UNTESTED
 def warn_func_effect_calls_disallowed_expr : Warning<
-  "'%0' function '%1' must not call non-'%0' expression">,
+  "'%0' function must not call non-'%0' expression">,
   InGroup<FunctionEffects>;
 
 def note_func_effect_calls_disallowed_func : Note<
-  "'%1' cannot be inferred '%0' because it calls non-'%0' function '%2'">;
+  "function cannot be inferred '%0' because it calls non-'%0' function">;
 
 def note_func_effect_call_extern : Note<
-  "'%1' cannot be inferred '%0' because it has no definition in this translation unit">;
+  "function cannot be inferred '%0' because it has no definition in this translation unit">;
 
 def note_func_effect_call_not_inferrable : Note<
-  "'%1' does not permit inference of '%0'">;
+  "function does not permit inference of '%0'">;
 
 def note_func_effect_call_virtual : Note<
-  "'%1' cannot be inferred '%0' because it is virtual">;
+  "virtual method cannot be inferred '%0'">;
 
 def note_func_effect_call_func_ptr : Note<
-  "'%1' cannot be inferred '%0' because it is a function pointer">;
+  "function pointer cannot be inferred '%0'">;
 
 // TODO: Not currently being generated
 // def warn_perf_annotation_implies_noexcept : Warning<
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 5903b792bfe1e8..0f6de7c83e4907 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -3035,7 +3035,6 @@ class Analyzer {
                 return SM.isBeforeInTranslationUnit(LHS.Loc, RHS.Loc);
               });
 
-    const auto TopFuncName = CInfo.name(S);
 
     // TODO: Can we get better template instantiation notes?
     auto checkAddTemplateNote = [&](const Decl *D) {
@@ -3059,48 +3058,47 @@ class Analyzer {
         break;
       case DiagnosticID::AllocatesMemory:
         S.Diag(Diag.Loc, diag::warn_func_effect_allocates)
-            << effectName << TopFuncName;
+            << effectName;
         checkAddTemplateNote(CInfo.CDecl);
         TESTED
         break;
       case DiagnosticID::Throws:
       case DiagnosticID::Catches:
         S.Diag(Diag.Loc, diag::warn_func_effect_throws_or_catches)
-            << effectName << TopFuncName;
+            << effectName;
         checkAddTemplateNote(CInfo.CDecl);
         TESTED
         break;
       case DiagnosticID::HasStaticLocal:
         S.Diag(Diag.Loc, diag::warn_func_effect_has_static_local)
-            << effectName << TopFuncName;
+            << effectName;
         checkAddTemplateNote(CInfo.CDecl);
         TESTED
         break;
       case DiagnosticID::AccessesThreadLocal:
         S.Diag(Diag.Loc, diag::warn_func_effect_uses_thread_local)
-            << effectName << TopFuncName;
+            << effectName;
         checkAddTemplateNote(CInfo.CDecl);
         TESTED
         break;
       case DiagnosticID::CallsObjC:
         S.Diag(Diag.Loc, diag::warn_func_effect_calls_objc)
-            << effectName << TopFuncName;
+            << effectName;
         checkAddTemplateNote(CInfo.CDecl);
         TESTED
         break;
       case DiagnosticID::CallsDisallowedExpr:
         S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_expr)
-            << effectName << TopFuncName;
+            << effectName;
         checkAddTemplateNote(CInfo.CDecl);
         UNTESTED
         break;
 
       case DiagnosticID::CallsUnsafeDecl: {
         CallableInfo CalleeInfo{*Diag.Callee};
-        auto CalleeName = CalleeInfo.name(S);
 
         S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_func)
-            << effectName << TopFuncName << CalleeName;
+            << effectName;
         checkAddTemplateNote(CInfo.CDecl);
 
         // Emit notes explaining the transitive chain of inferences: Why isn't
@@ -3115,16 +3113,16 @@ class Analyzer {
             // - virtual
             if (CalleeInfo.CType == CallType::Virtual) {
               S.Diag(Callee->getLocation(), diag::note_func_effect_call_virtual)
-                  << effectName << CalleeName;
+                  << effectName;
               TESTED
             } else if (CalleeInfo.CType == CallType::Unknown) {
               S.Diag(Callee->getLocation(),
                      diag::note_func_effect_call_func_ptr)
-                  << effectName << CalleeName;
+                  << effectName;
               TESTED
             } else {
               S.Diag(Callee->getLocation(), diag::note_func_effect_call_extern)
-                  << effectName << CalleeName;
+                  << effectName;
               TESTED
             }
             break;
@@ -3141,44 +3139,44 @@ class Analyzer {
             break;
           case DiagnosticID::DeclWithoutConstraintOrInference:
             S.Diag(Diag2.Loc, diag::note_func_effect_call_not_inferrable)
-                << effectName << CalleeName;
+                << effectName;
             TESTED
             break;
           case DiagnosticID::CallsDisallowedExpr:
             S.Diag(Diag2.Loc, diag::note_func_effect_call_func_ptr)
-                << effectName << CalleeName;
+                << effectName;
             UNTESTED
             break;
           case DiagnosticID::AllocatesMemory:
             S.Diag(Diag2.Loc, diag::note_func_effect_allocates)
-                << effectName << CalleeName;
+                << effectName;
             TESTED
             break;
           case DiagnosticID::Throws:
           case DiagnosticID::Catches:
             S.Diag(Diag2.Loc, diag::note_func_effect_throws_or_catches)
-                << effectName << CalleeName;
+                << effectName;
             TESTED
             break;
           case DiagnosticID::HasStaticLocal:
             S.Diag(Diag2.Loc, diag::note_func_effect_has_static_local)
-                << effectName << CalleeName;
+                << effectName;
             TESTED
             break;
           case DiagnosticID::AccessesThreadLocal:
             S.Diag(Diag2.Loc, diag::note_func_effect_uses_thread_local)
-                << effectName << CalleeName;
+                << effectName;
             UNTESTED
             break;
           case DiagnosticID::CallsObjC:
             S.Diag(Diag2.Loc, diag::note_func_effect_calls_objc)
-                << effectName << CalleeName;
+                << effectName;
             UNTESTED
             break;
           case DiagnosticID::CallsUnsafeDecl:
             MaybeNextCallee.emplace(*Diag2.Callee);
             S.Diag(Diag2.Loc, diag::note_func_effect_calls_disallowed_func)
-                << effectName << CalleeName << MaybeNextCallee->name(S);
+                << effectName;
             TESTED
             break;
           }
@@ -3186,7 +3184,6 @@ class Analyzer {
           Callee = Diag2.Callee;
           if (MaybeNextCallee) {
             CalleeInfo = *MaybeNextCallee;
-            CalleeName = CalleeInfo.name(S);
           }
         }
       } break;
diff --git a/clang/test/Sema/attr-nolock-constraints.cpp b/clang/test/Sema/attr-nolock-constraints.cpp
index 5d1efe931a1f91..d2d2ddbf04a2a8 100644
--- a/clang/test/Sema/attr-nolock-constraints.cpp
+++ b/clang/test/Sema/attr-nolock-constraints.cpp
@@ -10,66 +10,66 @@
 
 void nl1() [[clang::nolock]]
 {
-	auto* pInt = new int; // expected-warning {{'nolock' function 'nl1' must not allocate or deallocate memory}}
+	auto* pInt = new int; // expected-warning {{'nolock' function must not allocate or deallocate memory}}
 }
 
 void nl2() [[clang::nolock]]
 {
-	static int global; // expected-warning {{'nolock' function 'nl2' must not have static locals}}
+	static int global; // expected-warning {{'nolock' function must not have static locals}}
 }
 
 void nl3() [[clang::nolock]]
 {
 	try {
-		throw 42; // expected-warning {{'nolock' function 'nl3' must not throw or catch exceptions}}
+		throw 42; // expected-warning {{'nolock' function must not throw or catch exceptions}}
 	}
-	catch (...) { // expected-warning {{'nolock' function 'nl3' must not throw or catch exceptions}}
+	catch (...) { // expected-warning {{'nolock' function must not throw or catch exceptions}}
 	}
 }
 
 void nl4_inline() {}
-void nl4_not_inline(); // expected-note {{'nl4_not_inline' cannot be inferred 'nolock' because it has no definition in this translation unit}}
+void nl4_not_inline(); // expected-note {{function cannot be inferred 'nolock' because it has no definition in this translation unit}}
 
 void nl4() [[clang::nolock]]
 {
 	nl4_inline(); // OK
-	nl4_not_inline(); // expected-warning {{'nolock' function 'nl4' must not call non-'nolock' function 'nl4_not_inline'}}
+	nl4_not_inline(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
 }
 
 
 struct HasVirtual {
-	virtual void unsafe(); // expected-note {{'HasVirtual::unsafe' cannot be inferred 'nolock' because it is virtual}}
+	virtual void unsafe(); // expected-note {{virtual method cannot be inferred 'nolock'}}
 };
 
 void nl5() [[clang::nolock]]
 {
  	HasVirtual hv;
- 	hv.unsafe(); // expected-warning {{'nolock' function 'nl5' must not call non-'nolock' function 'HasVirtual::unsafe'}}
+ 	hv.unsafe(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
 }
 
-void nl6_unsafe(); // expected-note {{'nl6_unsafe' cannot be inferred 'nolock' because it has no definition in this translation unit}}
+void nl6_unsafe(); // expected-note {{function cannot be inferred 'nolock' because it has no definition in this translation unit}}
 void nl6_transitively_unsafe()
 {
-	nl6_unsafe(); // expected-note {{'nl6_transitively_unsafe' cannot be inferred 'nolock' because it calls non-'nolock' function 'nl6_unsafe'}}
+	nl6_unsafe(); // expected-note {{function cannot be inferred 'nolock' because it calls non-'nolock' function}}
 }
 
 void nl6() [[clang::nolock]]
 {
-	nl6_transitively_unsafe(); // expected-warning {{'nolock' function 'nl6' must not call non-'nolock' function 'nl6_transitively_unsafe'}}
+	nl6_transitively_unsafe(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
 }
 
 thread_local int tl_var{ 42 };
 
 bool tl_test() [[clang::nolock]]
 {
-	return tl_var > 0; // expected-warning {{'nolock' function 'tl_test' must not use thread-local variables}}
+	return tl_var > 0; // expected-warning {{'nolock' function must not use thread-local variables}}
 }
 
 void nl7()
 {
 	// Make sure we verify blocks
 	auto blk = ^() [[clang::nolock]] {
-		throw 42; // expected-warning {{'nolock' function '(block 0)' must not throw or catch exceptions}}
+		throw 42; // expected-warning {{'nolock' function must not throw or catch exceptions}}
 	};
 }
 
@@ -77,7 +77,7 @@ void nl8()
 {
 	// Make sure we verify lambdas
 	auto lambda = []() [[clang::nolock]] {
-		throw 42; // expected-warning {{'nolock' function 'nl8()::(anonymous class)::operator()' must not throw or catch exceptions}}
+		throw 42; // expected-warning {{'nolock' function must not throw or catch exceptions}}
 	};
 }
 
@@ -86,11 +86,11 @@ void nl8()
 	struct Adder {
 		static T add_explicit(T x, T y) [[clang::nolock]]
 		{
-			return x + y; // expected-warning {{'nolock' function 'Adder<Stringy>::add_explicit' must not call non-'nolock' function 'operator+'}}
+			return x + y; // expected-warning {{'nolock' function must not call non-'nolock' function}}
 		}
 		static T add_implicit(T x, T y)
 		{
-			return x + y; // expected-note {{'Adder<Stringy2>::add_implicit' cannot be inferred 'nolock' because it calls non-'nolock' function 'operator+'}}
+			return x + y; // expected-note {{function cannot be inferred 'nolock' because it calls non-'nolock' function}}
 		}
 	};
 
@@ -98,7 +98,7 @@ void nl8()
 		friend Stringy operator+(const Stringy& x, const Stringy& y)
 		{
 			// Do something inferably unsafe
-			auto* z = new char[42]; // expected-note {{'operator+' cannot be inferred 'nolock' because it allocates/deallocates memory}}
+			auto* z = new char[42]; // expected-note {{function cannot be inferred 'nolock' because it allocates/deallocates memory}}
 			return {};
 		}
 	};
@@ -107,7 +107,7 @@ void nl8()
 		friend Stringy2 operator+(const Stringy2& x, const Stringy2& y)
 		{
 			// Do something inferably unsafe
-			throw 42; // expected-note {{'operator+' cannot be inferred 'nolock' because it throws or catches exceptions}}
+			throw 42; // expected-note {{function cannot be inferred 'nolock' because it throws or catches exceptions}}
 		}
 	};
 
@@ -117,32 +117,32 @@ void nl9() [[clang::nolock]]
 	Adder<int>::add_implicit(1, 2);
 
 	Adder<Stringy>::add_explicit({}, {}); // expected-note {{in template expansion here}}
-	Adder<Stringy2>::add_implicit({}, {}); // expected-warning {{'nolock' function 'nl9' must not call non-'nolock' function 'Adder<Stringy2>::add_implicit'}} \
+	Adder<Stringy2>::add_implicit({}, {}); // expected-warning {{'nolock' function must not call non-'nolock' function}} \
 		expected-note {{in template expansion here}}
 }
 
 void nl10(
-	void (*fp1)(), // expected-note {{'fp1' cannot be inferred 'nolock' because it is a function pointer}}
+	void (*fp1)(), // expected-note {{function pointer cannot be inferred 'nolock'}}
 	void (*fp2)() [[clang::nolock]]
 	) [[clang::nolock]]
 {
-	fp1(); // expected-warning {{'nolock' function 'nl10' must not call non-'nolock' function 'fp1'}}
+	fp1(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
 	fp2();
 }
 
 // Interactions with nolock(false)
-void nl11_no_inference() [[clang::nolock(false)]] // expected-note {{'nl11_no_inference' does not permit inference of 'nolock'}}
+void nl11_no_inference() [[clang::nolock(false)]] // expected-note {{function does not permit inference of 'nolock'}}
 {
 }
 
 void nl11() [[clang::nolock]]
 {
-	nl11_no_inference(); // expected-warning {{'nolock' function 'nl11' must not call non-'nolock' function 'nl11_no_inference'}}
+	nl11_no_inference(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
 }
 
 // Verify that when attached to a redeclaration, the attribute successfully attaches.
 void nl12() {
-	static int x; // expected-warning {{'nolock' function 'nl12' must not have static locals}}
+	static int x; // expected-warning {{'nolock' function must not have static locals}}
 }
 void nl12() [[clang::nolock]];
 void nl13() [[clang::nolock]] { nl12(); }

>From 62b125efb4ded8981c2e0ba4bf338f0169adc203 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 20 Mar 2024 08:52:06 -0700
Subject: [PATCH 18/40] Functionality: - Effects can allow themselves to be
 propagated from virtual methods in base class to overridden methods in
 derived classes.

Fixes:
- In constraint analysis, map must be keyed with canonical decls; but decls as analyzed should be definitions wherever possible.
- FunctionEffect needs explicit padding
- Tests in Objective-C
- Don't trap on recursion; ignore recursive calls when completing function analysis.
- Handle pointers to member function, expressions of type BlockPointerType
- followCall() needs to combine declared and inferred effects of callee.
- FunctionEffectSet::get() receives a QualType instead of Type& now. It knows how to peel off references now.
- MutableFunctionEffectSet::insert fix: wasn't handling Iter == end() correctly
- Sema::IsFunctionConversion: fix: wasn't correctly removing nolock after removing noexcept
- Remove debug macros marking untested cases
---
 clang/include/clang/AST/Type.h                |  32 +++-
 .../clang/Basic/DiagnosticSemaKinds.td        |  10 +-
 clang/lib/AST/Decl.cpp                        |   8 +-
 clang/lib/AST/Type.cpp                        |  38 ++--
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 173 +++++++++++-------
 clang/lib/Sema/Sema.cpp                       |   4 +-
 clang/lib/Sema/SemaDeclCXX.cpp                |  21 ++-
 clang/lib/Sema/SemaOverload.cpp               |   2 +
 ...traints.cpp => attr-nolock-constraints.mm} |  42 +++++
 clang/test/Sema/attr-nolock-sema.cpp          |  57 +++---
 clang/test/Sema/attr-nolock-syntax.cpp        |   9 +
 clang/test/Sema/attr-nolock-wip.cpp           |  80 ++++++--
 12 files changed, 329 insertions(+), 147 deletions(-)
 rename clang/test/Sema/{attr-nolock-constraints.cpp => attr-nolock-constraints.mm} (82%)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index ca4660edb2f56f..3d7ef5f951ee1d 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4197,6 +4197,7 @@ class TypeSourceInfo;
 /// Represents an abstract function effect.
 class FunctionEffect {
 public:
+  /// Identifies the particular type of effect.
   enum class Type {
     None = 0,
     NoLockTrue,
@@ -4229,6 +4230,14 @@ class FunctionEffect {
     FE_ExcludeThreadLocalVars = 0x80
   };
 
+  /// Describes the result of effects differing between a base class's virtual
+  /// method and an overriding method in a subclass.
+  enum class OverrideResult {
+    Ignore,
+    Warn,
+    Propagate // Base method's effects are merged with those of the override.
+  };
+
 private:
   // For uniqueness, currently only Type_ is significant.
 
@@ -4240,11 +4249,15 @@ class FunctionEffect {
   // then ~16(?) bits "Subtype" to map to a specific named TCB. Subtype would
   // be considered for uniqueness.
 
+  // Since this struct is serialized as if it were a uint32_t, it's important
+  // to pad and explicitly zero the extra bits.
+  [[maybe_unused]] unsigned Padding : 22;
+
 public:
   using CalleeDeclOrType =
       llvm::PointerUnion<const Decl *, const FunctionProtoType *>;
 
-  FunctionEffect() : Type_(unsigned(Type::None)), Flags_(0) {}
+  FunctionEffect() : Type_(unsigned(Type::None)), Flags_(0), Padding(0) {}
 
   explicit FunctionEffect(Type T);
 
@@ -4257,7 +4270,7 @@ class FunctionEffect {
   /// The description printed in diagnostics, e.g. 'nolock'.
   StringRef name() const;
 
-  /// A serializable, hashable representation.
+  /// A hashable representation.
   uint32_t opaqueRepr() const { return Type_ | (Flags_ << 2u); }
 
   /// Return true if adding or removing the effect as part of a type conversion
@@ -4275,10 +4288,11 @@ class FunctionEffect {
 
   /// Return true if adding or removing the effect in a C++ virtual method
   /// override should generate a diagnostic.
-  bool diagnoseMethodOverride(bool Adding, const CXXMethodDecl &OldMethod,
-                              FunctionEffectSet OldFX,
-                              const CXXMethodDecl &NewMethod,
-                              FunctionEffectSet NewFX) const;
+  OverrideResult diagnoseMethodOverride(bool Adding,
+                                        const CXXMethodDecl &OldMethod,
+                                        FunctionEffectSet OldFX,
+                                        const CXXMethodDecl &NewMethod,
+                                        FunctionEffectSet NewFX) const;
 
   /// Return true if the effect is allowed to be inferred on a Decl of the
   /// specified type (generally a FunctionProtoType but TypeSourceInfo is
@@ -4387,9 +4401,9 @@ class FunctionEffectSet {
   static Differences differences(const FunctionEffectSet &Old,
                                  const FunctionEffectSet &New);
 
-  /// Extract the effects from a Type if it is a BlockType or FunctionProtoType,
-  /// or pointer to one.
-  static FunctionEffectSet get(const Type &TyRef);
+  /// Extract the effects from a Type if it is a function, block, member
+  /// function pointer, reference or pointer to one.
+  static FunctionEffectSet get(QualType QT);
 };
 
 /// Represents a prototype with parameter type info, e.g.
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index f50a572fe7f5e2..e841fdb4fd511a 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10814,16 +10814,15 @@ def note_func_effect_calls_objc : Note<
   "function cannot be inferred '%0' because it accesses an ObjC method or property">;
 
 def warn_func_effect_calls_disallowed_func : Warning<
-  "'%0' function must not call non-'%0' function">,
+  "'%0' function must not call non-'%0' function '%1'">,
   InGroup<FunctionEffects>;
 
-// UNTESTED
 def warn_func_effect_calls_disallowed_expr : Warning<
   "'%0' function must not call non-'%0' expression">,
   InGroup<FunctionEffects>;
 
 def note_func_effect_calls_disallowed_func : Note<
-  "function cannot be inferred '%0' because it calls non-'%0' function">;
+  "function cannot be inferred '%0' because it calls non-'%0' function '%1'">;
 
 def note_func_effect_call_extern : Note<
   "function cannot be inferred '%0' because it has no definition in this translation unit">;
@@ -10851,11 +10850,6 @@ def warn_func_effect_false_on_type : Warning<
 def note_func_effect_from_template : Note<
   "in template expansion here">;
 
-// TODO: Needs to be tested
-def warn_incompatible_func_effects : Warning<
-  "attributes '%0' and '%1' are incompatible">,
-  InGroup<FunctionEffects>;
-
 // spoofing nolock/noalloc
 def warn_invalid_add_func_effects : Warning<
   "attribute '%0' should not be added via type conversion">,
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 827d57e07d6037..e4171d2a3e0a8a 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -4502,10 +4502,12 @@ unsigned FunctionDecl::getODRHash() {
   return ODRHash;
 }
 
-// Effects may differ between declarations, but they should be propagated from old
-// to new on any redeclaration, so it suffices to look at getMostRecentDecl().
+// Effects may differ between declarations, but they should be propagated from
+// old to new on any redeclaration, so it suffices to look at
+// getMostRecentDecl().
 FunctionEffectSet FunctionDecl::getFunctionEffects() const {
-  if (const auto *FPT = getMostRecentDecl()->getType()->getAs<FunctionProtoType>()) {
+  if (const auto *FPT =
+          getMostRecentDecl()->getType()->getAs<FunctionProtoType>()) {
     return FPT->getFunctionEffects();
   }
   return {};
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 06f9c0190bad6f..515971d650f592 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -4922,7 +4922,8 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
           getTypeConstraintConcept(), getTypeConstraintArguments());
 }
 
-FunctionEffect::FunctionEffect(Type T) : Type_(unsigned(T)), Flags_(0) {
+FunctionEffect::FunctionEffect(Type T)
+    : Type_(unsigned(T)), Flags_(0), Padding(0) {
   switch (T) {
   case Type::NoLockTrue:
     Flags_ = FE_RequiresVerification | FE_VerifyCalls | FE_InferrableOnCallees |
@@ -4994,21 +4995,19 @@ bool FunctionEffect::diagnoseRedeclaration(bool Adding,
   return false;
 }
 
-bool FunctionEffect::diagnoseMethodOverride(bool Adding,
-                                            const CXXMethodDecl &OldMethod,
-                                            FunctionEffectSet OldFX,
-                                            const CXXMethodDecl &NewMethod,
-                                            FunctionEffectSet NewFX) const {
+FunctionEffect::OverrideResult FunctionEffect::diagnoseMethodOverride(
+    bool Adding, const CXXMethodDecl &OldMethod, FunctionEffectSet OldFX,
+    const CXXMethodDecl &NewMethod, FunctionEffectSet NewFX) const {
   switch (type()) {
   case Type::NoAllocTrue:
   case Type::NoLockTrue:
     // nolock/noalloc can't be removed from an override
     // adding -> false, removing -> true (diagnose)
-    return !Adding;
+    return Adding ? OverrideResult::Ignore : OverrideResult::Propagate;
   default:
     break;
   }
-  return false;
+  return OverrideResult::Ignore;
 }
 
 bool FunctionEffect::canInferOnFunction(QualType QT,
@@ -5062,7 +5061,7 @@ MutableFunctionEffectSet::MutableFunctionEffectSet(
 
 void MutableFunctionEffectSet::insert(const FunctionEffect &Effect) {
   const auto &Iter = std::lower_bound(begin(), end(), Effect);
-  if (*Iter != Effect) {
+  if (Iter == end() || *Iter != Effect) {
     insert(Iter, Effect);
   }
 }
@@ -5112,12 +5111,23 @@ FunctionEffectSet::operator&(const FunctionEffectSet &RHS) const {
 }
 
 // TODO: inline?
-FunctionEffectSet FunctionEffectSet::get(const Type &TyRef) {
-  const Type *Ty = &TyRef;
-  if (Ty->isPointerType())
-    Ty = Ty->getPointeeType().getTypePtr();
-  if (const auto *FPT = Ty->getAs<FunctionProtoType>())
+FunctionEffectSet FunctionEffectSet::get(QualType QT) {
+  if (QT->isReferenceType())
+    QT = QT.getNonReferenceType();
+  if (QT->isPointerType())
+    QT = QT->getPointeeType();
+
+  if (const auto *BT = QT->getAs<BlockPointerType>()) {
+    QT = BT->getPointeeType();
+  } else if (const auto *MP = QT->getAs<MemberPointerType>()) {
+    if (MP->isMemberFunctionPointer()) {
+      QT = MP->getPointeeType();
+    }
+  }
+
+  if (const auto *FPT = QT->getAs<FunctionProtoType>())
     return FPT->getFunctionEffects();
+
   return {};
 }
 
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 0f6de7c83e4907..10228715ea1bb9 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2389,6 +2389,12 @@ class UnsafeBufferUsageReporter : public UnsafeBufferUsageHandler {
 
 namespace FXAnalysis {
 
+#define tmp_assert(x)                                                          \
+  do {                                                                         \
+    if (!(x))                                                                  \
+      __builtin_trap();                                                        \
+  } while (0)
+
 enum class DiagnosticID : uint8_t {
   None = 0, // sentinel for an empty Diagnostic
   Throws,
@@ -2445,6 +2451,7 @@ static bool functionIsVerifiable(const FunctionDecl *FD) {
 // Transitory, more extended information about a callable, which can be a
 // function, block, function pointer...
 struct CallableInfo {
+  // CDecl holds the function's definition, if any.
   const Decl *CDecl;
   mutable std::optional<std::string>
       MaybeName; // mutable because built on demand in const method
@@ -2461,10 +2468,6 @@ struct CallableInfo {
       // Use the function's definition, if any.
       if (auto *Def = FD->getDefinition()) {
         CDecl = FD = Def;
-        // is the definition always canonical?
-        assert(FD->getCanonicalDecl() == FD);
-      } else {
-        FD = FD->getCanonicalDecl();
       }
       CType = CallType::Function;
       if (auto *Method = dyn_cast<CXXMethodDecl>(FD)) {
@@ -2481,7 +2484,7 @@ struct CallableInfo {
     } else if (auto *VD = dyn_cast<ValueDecl>(CDecl)) {
       // ValueDecl is function, enum, or variable, so just look at the type.
       QT = VD->getType();
-      Effects = FunctionEffectSet::get(*QT);
+      Effects = FunctionEffectSet::get(QT);
     }
   }
 
@@ -2580,8 +2583,19 @@ class PendingFunctionAnalysis {
   friend class CompleteFunctionAnalysis;
 
   struct DirectCall {
-    const Decl *Callee;
+    // Pack a Decl* and a bool indicating whether the call was detected
+    // to be recursive. Not all recursive calls are detected, just enough
+    // to break cycles.
+    llvm::PointerIntPair<const Decl *, 1> CalleeAndRecursed;
     SourceLocation CallLoc;
+
+    DirectCall(const Decl *D, SourceLocation CallLoc)
+        : CalleeAndRecursed(D), CallLoc(CallLoc) {}
+
+    const Decl *callee() const { return CalleeAndRecursed.getPointer(); }
+    bool recursed() const { return CalleeAndRecursed.getInt(); }
+
+    void setRecursed() { CalleeAndRecursed.setInt(1); }
   };
 
 public:
@@ -2664,7 +2678,7 @@ class PendingFunctionAnalysis {
     if (UnverifiedDirectCalls == nullptr) {
       UnverifiedDirectCalls = std::make_unique<SmallVector<DirectCall>>();
     }
-    UnverifiedDirectCalls->emplace_back(DirectCall{D, CallLoc});
+    UnverifiedDirectCalls->emplace_back(D, CallLoc);
   }
 
   // Analysis is complete when there are no unverified direct calls.
@@ -2676,8 +2690,8 @@ class PendingFunctionAnalysis {
     return InferrableEffectToFirstDiagnostic.lookup(effect);
   }
 
-  const SmallVector<DirectCall> &unverifiedCalls() const {
-    assert(!isComplete());
+  SmallVector<DirectCall> &unverifiedCalls() const {
+    tmp_assert(!isComplete());
     return *UnverifiedDirectCalls;
   }
 
@@ -2685,7 +2699,8 @@ class PendingFunctionAnalysis {
     return DiagnosticsForExplicitFX.get();
   }
 
-  void dump(llvm::raw_ostream &OS) const {
+  // If Sema is supplied, prints names of unverified direct calls
+  void dump(llvm::raw_ostream &OS, Sema *SemPtr = nullptr) const {
     OS << "Pending: Declared ";
     DeclaredVerifiableEffects.dump(OS);
     OS << ", "
@@ -2693,7 +2708,15 @@ class PendingFunctionAnalysis {
        << " diags; ";
     OS << " Infer ";
     FXToInfer.dump(OS);
-    OS << ", " << InferrableEffectToFirstDiagnostic.size() << " diags\n";
+    OS << ", " << InferrableEffectToFirstDiagnostic.size() << " diags";
+    if (SemPtr && UnverifiedDirectCalls) {
+      OS << "; Calls: ";
+      for (const auto &Call : *UnverifiedDirectCalls) {
+        CallableInfo CI(*Call.callee());
+        OS << " " << CI.name(*SemPtr);
+      }
+    }
+    OS << "\n";
   }
 };
 
@@ -2753,15 +2776,23 @@ class CompleteFunctionAnalysis {
         }
 */
 
+const Decl *CanonicalFunctionDecl(const Decl *D) {
+  if (auto *FD = dyn_cast<FunctionDecl>(D)) {
+    FD = FD->getCanonicalDecl();
+    tmp_assert(FD != nullptr);
+    return FD;
+  }
+  return D;
+}
+
 // ==========
 class Analyzer {
   constexpr static int DebugLogLevel = 0;
-
   // --
   Sema &Sem;
 
   // used from Sema:
-  //  SmallVector<const Decl *> DeclsWithEffectsToVerify
+  //  SmallVector<const Decl *> CallablesWithEffectsToVerify
 
   // Subset of Sema.AllEffectsToVerify
   FunctionEffectSet AllInferrableEffectsToVerify;
@@ -2772,11 +2803,22 @@ class Analyzer {
   // Map all Decls analyzed to FuncAnalysisPtr. Pending state is larger
   // than complete state, so use different objects to represent them.
   // The state pointers are owned by the container.
-  struct AnalysisMap : public llvm::DenseMap<const Decl *, FuncAnalysisPtr> {
+  class AnalysisMap : protected llvm::DenseMap<const Decl *, FuncAnalysisPtr> {
+    using Base = llvm::DenseMap<const Decl *, FuncAnalysisPtr>;
 
+  public:
     ~AnalysisMap();
 
-    // use lookup()
+    // Use non-public inheritance in order to maintain the invariant
+    // that lookups and insertions are via the canonical Decls.
+
+    FuncAnalysisPtr lookup(const Decl *Key) const {
+      return Base::lookup(CanonicalFunctionDecl(Key));
+    }
+
+    FuncAnalysisPtr &operator[](const Decl *Key) {
+      return Base::operator[](CanonicalFunctionDecl(Key));
+    }
 
     /// Shortcut for the case where we only care about completed analysis.
     CompleteFunctionAnalysis *completedAnalysisForDecl(const Decl *D) const {
@@ -2789,7 +2831,7 @@ class Analyzer {
     }
 
     void dump(Sema &S, llvm::raw_ostream &OS) {
-      OS << "AnalysisMap:\n";
+      OS << "\nAnalysisMap:\n";
       for (const auto &item : *this) {
         CallableInfo CI(*item.first);
         const auto AP = item.second;
@@ -2807,6 +2849,7 @@ class Analyzer {
         } else
           llvm_unreachable("never");
       }
+      OS << "---\n";
     }
   };
   AnalysisMap DeclAnalysis;
@@ -2839,7 +2882,7 @@ class Analyzer {
 
     SmallVector<const Decl *> &verifyQueue = Sem.DeclsWithEffectsToVerify;
 
-    // It's helpful to use DeclsWithEffectsToVerify as a stack for a
+    // It's helpful to use CallablesWithEffectsToVerify as a stack for a
     // depth-first traversal rather than have a secondary container. But first,
     // reverse it, so Decls are verified in the order they are declared.
     std::reverse(verifyQueue.begin(), verifyQueue.end());
@@ -2869,19 +2912,21 @@ class Analyzer {
         continue;
       }
 
-      for (const auto &Call : Pending->unverifiedCalls()) {
+      for (auto &Call : Pending->unverifiedCalls()) {
         // This lookup could be optimized out if the results could have been
         // saved from followCall when we traversed the caller's AST. It would
         // however make the check for recursion more complex.
-        auto AP = DeclAnalysis.lookup(Call.Callee);
+        auto AP = DeclAnalysis.lookup(Call.callee());
         if (AP.isNull()) {
-          verifyQueue.push_back(Call.Callee);
+          verifyQueue.push_back(Call.callee());
           continue;
         }
         if (isa<PendingFunctionAnalysis *>(AP)) {
-          // $$$$$$$$$$$$$$$$$$$$$$$ recursion $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
-          // TODO
-          __builtin_trap();
+          // This indicates recursion (not necessarily direct). For the
+          // purposes of effect analysis, we can just ignore it since
+          // no effects forbid recursion.
+          Call.setRecursed();
+          continue;
         }
         llvm_unreachable("unexpected DeclAnalysis item");
       }
@@ -2892,13 +2937,8 @@ class Analyzer {
   // Verify a single Decl. Return the pending structure if that was the result,
   // else null. This method must not recurse.
   PendingFunctionAnalysis *verifyDecl(const Decl *D) {
-    // TODO: Is this in the right place?
-    const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
-    if (FD != nullptr) {
-      // Currently, built-in functions are always considered safe.
-      if (FD->getBuiltinID() != 0) {
-        return nullptr;
-      }
+    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+      tmp_assert(FD->getBuiltinID() == 0);
     }
     CallableInfo CInfo(*D);
 
@@ -2951,8 +2991,16 @@ class Analyzer {
   // the possibility of inference.
   void finishPendingAnalysis(const Decl *D, PendingFunctionAnalysis *Pending) {
     CallableInfo Caller(*D);
+    if constexpr (DebugLogLevel > 0) {
+      llvm::outs() << "finishPendingAnalysis for " << Caller.name(Sem) << " : ";
+      Pending->dump(llvm::outs(), &Sem);
+      llvm::outs() << "\n";
+    }
     for (const auto &Call : Pending->unverifiedCalls()) {
-      CallableInfo Callee(*Call.Callee);
+      if (Call.recursed())
+        continue;
+
+      CallableInfo Callee(*Call.callee());
       followCall(Caller, *Pending, Callee, Call.CallLoc,
                  /*AssertNoFurtherInference=*/true);
     }
@@ -2966,17 +3014,22 @@ class Analyzer {
                   const CallableInfo &Callee, SourceLocation CallLoc,
                   bool AssertNoFurtherInference) {
     const bool DirectCall = Callee.isDirectCall();
+
+    // These will be its declared effects.
     FunctionEffectSet CalleeEffects = Callee.Effects;
+
     bool IsInferencePossible = DirectCall;
 
     if (DirectCall) {
       if (auto *CFA = DeclAnalysis.completedAnalysisForDecl(Callee.CDecl)) {
-        CalleeEffects = CFA->VerifiedEffects;
+        // Combine declared effects with those which may have been inferred.
+        CalleeEffects = FunctionEffectSet::getUnion(
+            Sem.getASTContext(), CalleeEffects, CFA->VerifiedEffects);
         IsInferencePossible = false; // we've already traversed it
       }
     }
     if (AssertNoFurtherInference) {
-      assert(!IsInferencePossible);
+      tmp_assert(!IsInferencePossible);
     }
     if (!Callee.isVerifiable()) {
       IsInferencePossible = false;
@@ -2987,6 +3040,12 @@ class Analyzer {
                    << "; verifiable: " << Callee.isVerifiable() << "; callee ";
       CalleeEffects.dump(llvm::outs());
       llvm::outs() << "\n";
+      llvm::outs() << "  callee " << Callee.CDecl << " canonical "
+                   << CanonicalFunctionDecl(Callee.CDecl) << " redecls";
+      for (auto *D : Callee.CDecl->redecls()) {
+        llvm::outs() << " " << D;
+      }
+      llvm::outs() << "\n";
     }
 
     auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
@@ -3027,15 +3086,12 @@ class Analyzer {
   // Should only be called when determined to be complete.
   void emitDiagnostics(SmallVector<Diagnostic> &Diags,
                        const CallableInfo &CInfo, Sema &S) {
-#define UNTESTED __builtin_trap();
-#define TESTED
     const SourceManager &SM = S.getSourceManager();
     std::sort(Diags.begin(), Diags.end(),
               [&SM](const Diagnostic &LHS, const Diagnostic &RHS) {
                 return SM.isBeforeInTranslationUnit(LHS.Loc, RHS.Loc);
               });
 
-
     // TODO: Can we get better template instantiation notes?
     auto checkAddTemplateNote = [&](const Decl *D) {
       if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
@@ -3057,48 +3113,40 @@ class Analyzer {
         llvm_unreachable("Unexpected diagnostic kind");
         break;
       case DiagnosticID::AllocatesMemory:
-        S.Diag(Diag.Loc, diag::warn_func_effect_allocates)
-            << effectName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_allocates) << effectName;
         checkAddTemplateNote(CInfo.CDecl);
-        TESTED
         break;
       case DiagnosticID::Throws:
       case DiagnosticID::Catches:
         S.Diag(Diag.Loc, diag::warn_func_effect_throws_or_catches)
             << effectName;
         checkAddTemplateNote(CInfo.CDecl);
-        TESTED
         break;
       case DiagnosticID::HasStaticLocal:
-        S.Diag(Diag.Loc, diag::warn_func_effect_has_static_local)
-            << effectName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_has_static_local) << effectName;
         checkAddTemplateNote(CInfo.CDecl);
-        TESTED
         break;
       case DiagnosticID::AccessesThreadLocal:
         S.Diag(Diag.Loc, diag::warn_func_effect_uses_thread_local)
             << effectName;
         checkAddTemplateNote(CInfo.CDecl);
-        TESTED
         break;
       case DiagnosticID::CallsObjC:
-        S.Diag(Diag.Loc, diag::warn_func_effect_calls_objc)
-            << effectName;
+        S.Diag(Diag.Loc, diag::warn_func_effect_calls_objc) << effectName;
         checkAddTemplateNote(CInfo.CDecl);
-        TESTED
         break;
       case DiagnosticID::CallsDisallowedExpr:
         S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_expr)
             << effectName;
         checkAddTemplateNote(CInfo.CDecl);
-        UNTESTED
         break;
 
       case DiagnosticID::CallsUnsafeDecl: {
         CallableInfo CalleeInfo{*Diag.Callee};
+        auto CalleeName = CalleeInfo.name(S);
 
         S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_func)
-            << effectName;
+            << effectName << CalleeName;
         checkAddTemplateNote(CInfo.CDecl);
 
         // Emit notes explaining the transitive chain of inferences: Why isn't
@@ -3114,16 +3162,13 @@ class Analyzer {
             if (CalleeInfo.CType == CallType::Virtual) {
               S.Diag(Callee->getLocation(), diag::note_func_effect_call_virtual)
                   << effectName;
-              TESTED
             } else if (CalleeInfo.CType == CallType::Unknown) {
               S.Diag(Callee->getLocation(),
                      diag::note_func_effect_call_func_ptr)
                   << effectName;
-              TESTED
             } else {
               S.Diag(Callee->getLocation(), diag::note_func_effect_call_extern)
                   << effectName;
-              TESTED
             }
             break;
           }
@@ -3140,50 +3185,41 @@ class Analyzer {
           case DiagnosticID::DeclWithoutConstraintOrInference:
             S.Diag(Diag2.Loc, diag::note_func_effect_call_not_inferrable)
                 << effectName;
-            TESTED
             break;
           case DiagnosticID::CallsDisallowedExpr:
             S.Diag(Diag2.Loc, diag::note_func_effect_call_func_ptr)
                 << effectName;
-            UNTESTED
             break;
           case DiagnosticID::AllocatesMemory:
-            S.Diag(Diag2.Loc, diag::note_func_effect_allocates)
-                << effectName;
-            TESTED
+            S.Diag(Diag2.Loc, diag::note_func_effect_allocates) << effectName;
             break;
           case DiagnosticID::Throws:
           case DiagnosticID::Catches:
             S.Diag(Diag2.Loc, diag::note_func_effect_throws_or_catches)
                 << effectName;
-            TESTED
             break;
           case DiagnosticID::HasStaticLocal:
             S.Diag(Diag2.Loc, diag::note_func_effect_has_static_local)
                 << effectName;
-            TESTED
             break;
           case DiagnosticID::AccessesThreadLocal:
             S.Diag(Diag2.Loc, diag::note_func_effect_uses_thread_local)
                 << effectName;
-            UNTESTED
             break;
           case DiagnosticID::CallsObjC:
-            S.Diag(Diag2.Loc, diag::note_func_effect_calls_objc)
-                << effectName;
-            UNTESTED
+            S.Diag(Diag2.Loc, diag::note_func_effect_calls_objc) << effectName;
             break;
           case DiagnosticID::CallsUnsafeDecl:
             MaybeNextCallee.emplace(*Diag2.Callee);
             S.Diag(Diag2.Loc, diag::note_func_effect_calls_disallowed_func)
-                << effectName;
-            TESTED
+                << effectName << MaybeNextCallee->name(S);
             break;
           }
           checkAddTemplateNote(Callee);
           Callee = Diag2.Callee;
           if (MaybeNextCallee) {
             CalleeInfo = *MaybeNextCallee;
+            CalleeName = CalleeInfo.name(S);
           }
         }
       } break;
@@ -3276,6 +3312,11 @@ class Analyzer {
     // Here we have a call to a Decl, either explicitly via a CallExpr or some
     // other AST construct. CallableInfo pertains to the callee.
     void followCall(const CallableInfo &CI, SourceLocation CallLoc) {
+      if (const auto *FD = dyn_cast<FunctionDecl>(CI.CDecl)) {
+        // Currently, built-in functions are always considered safe.
+        if (FD->getBuiltinID() != 0)
+          return;
+      }
       Outer.followCall(CurrentCaller, CurrentFunction, CI, CallLoc,
                        /*AssertNoFurtherInference=*/false);
     }
@@ -3542,7 +3583,7 @@ class Analyzer {
   };
 
 #if FX_ANALYZER_VERIFY_DECL_LIST
-  // Sema has accumulated DeclsWithEffectsToVerify. As a debug check, do our
+  // Sema has accumulated CallablesWithEffectsToVerify. As a debug check, do our
   // own AST traversal and see what we find.
 
   using MatchFinder = ast_matchers::MatchFinder;
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 05b771939feb13..874243495ea39b 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -588,8 +588,8 @@ void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
 // Generate diagnostics when adding or removing effects in a type conversion.
 void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
                                             SourceLocation Loc) {
-  const auto SrcFX = FunctionEffectSet::get(*SrcType);
-  const auto DstFX = FunctionEffectSet::get(*DstType);
+  const auto SrcFX = FunctionEffectSet::get(SrcType);
+  const auto DstFX = FunctionEffectSet::get(DstType);
   if (SrcFX != DstFX) {
     for (const auto &Item : FunctionEffectSet::differences(SrcFX, DstFX)) {
       const FunctionEffect &Effect = Item.first;
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 2c163ce4c14b03..dfc442e646d169 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18332,11 +18332,30 @@ bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
     for (const auto &Item : Diffs) {
       const FunctionEffect &Effect = Item.first;
       const bool Adding = Item.second;
-      if (Effect.diagnoseMethodOverride(Adding, *Old, OldFX, *New, NewFX)) {
+      switch (Effect.diagnoseMethodOverride(Adding, *Old, OldFX, *New, NewFX)) {
+      case FunctionEffect::OverrideResult::Ignore:
+        break;
+      case FunctionEffect::OverrideResult::Warn:
         Diag(New->getLocation(), diag::warn_mismatched_func_effect_override)
             << Effect.name();
         Diag(Old->getLocation(), diag::note_overridden_virtual_function);
+        // TODO: It would be nice to have a FIXIT here!
         AnyDiags = true;
+        break;
+      case FunctionEffect::OverrideResult::Propagate: {
+        auto MergedFX = FunctionEffectSet::getUnion(Context, OldFX, NewFX);
+
+        FunctionProtoType::ExtProtoInfo EPI = NewFT->getExtProtoInfo();
+        EPI.FunctionEffects = MergedFX;
+        QualType ModQT = Context.getFunctionType(NewFT->getReturnType(),
+                                                 NewFT->getParamTypes(), EPI);
+
+        // TODO: It's ugly to be mutating the incoming const method. It is
+        // mutable in the calling function, though. There is also the
+        // possibility here that we are discarding some other sort of sugar on
+        // the method's type.
+        const_cast<CXXMethodDecl *>(New)->setType(ModQT);
+      } break;
       }
     }
     if (AnyDiags)
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 0163969e9bf50d..e26d1ef9d2bb51 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1873,6 +1873,8 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
       // For C, when called from checkPointerTypesForAssignment,
       // we need not to change the type, or else even an innocuous cast
       // like dropping effects will fail.
+      FromFPT =
+          dyn_cast<FunctionProtoType>(FromFn); // in case FromFn changed above
 
       // Transparently add/drop effects; here we are concerned with
       // language rules/canonicalization. Adding/dropping effects is a warning.
diff --git a/clang/test/Sema/attr-nolock-constraints.cpp b/clang/test/Sema/attr-nolock-constraints.mm
similarity index 82%
rename from clang/test/Sema/attr-nolock-constraints.cpp
rename to clang/test/Sema/attr-nolock-constraints.mm
index d2d2ddbf04a2a8..e52b50eac519f4 100644
--- a/clang/test/Sema/attr-nolock-constraints.cpp
+++ b/clang/test/Sema/attr-nolock-constraints.mm
@@ -146,3 +146,45 @@ void nl12() {
 }
 void nl12() [[clang::nolock]];
 void nl13() [[clang::nolock]] { nl12(); }
+
+// Objective-C
+ at interface OCClass
+- (void)method;
+ at end
+
+void nl14(OCClass *oc) [[clang::nolock]] {
+	[oc method]; // expected-warning {{'nolock' function must not access an ObjC method or property}}
+}
+void nl15(OCClass *oc) {
+	[oc method]; // expected-note {{function cannot be inferred 'nolock' because it accesses an ObjC method or property}}
+}
+void nl16(OCClass *oc) [[clang::nolock]] {
+	nl15(oc); // expected-warning {{'nolock' function must not call non-'nolock' function 'nl15'}}
+}
+
+// C++ member function pointers
+struct PTMFTester {
+	typedef void (PTMFTester::*ConvertFunction)() [[clang::nolock]];
+
+	void convert() [[clang::nolock]];
+
+	ConvertFunction mConvertFunc;
+};
+
+void PTMFTester::convert() [[clang::nolock]]
+{
+	(this->*mConvertFunc)();
+}
+
+// Block variables
+void nl17(void (^blk)() [[clang::nolock]]) [[clang::nolock]] {
+	blk();
+}
+
+// References to blocks
+void nl18(void (^block)() [[clang::nolock]]) [[clang::nolock]]
+{
+	auto &ref = block;
+	ref();
+}
+
diff --git a/clang/test/Sema/attr-nolock-sema.cpp b/clang/test/Sema/attr-nolock-sema.cpp
index 28542be0a2ecd0..98a11067305d56 100644
--- a/clang/test/Sema/attr-nolock-sema.cpp
+++ b/clang/test/Sema/attr-nolock-sema.cpp
@@ -59,18 +59,37 @@ void type_conversions()
 	fp_noalloc = unannotated; // expected-warning {{attribute 'noalloc' should not be added via type conversion}}
 }
 
+#ifdef __cplusplus
+// There was a bug: noexcept and nolock could be individually removed in conversion, but not both	
+void type_conversions_2()
+{
+	auto receives_fp = [](void (*fp)()) {
+	};
+	
+	auto ne = +[]() noexcept {};
+	auto nl = +[]() [[clang::nolock]] {};
+	auto nl_ne = +[]() noexcept [[clang::nolock]] {};
+	
+	receives_fp(ne);
+	receives_fp(nl);
+	receives_fp(nl_ne);
+}
+#endif
+
 // --- VIRTUAL METHODS ---
+// Attributes propagate to overridden methods, so no diagnostics.
+// Check this in the syntax tests too.
 #ifdef __cplusplus
 struct Base {
 	virtual void f1();
-	virtual void nolock() noexcept [[clang::nolock]]; // expected-note {{overridden virtual function is here}}
-	virtual void noalloc() noexcept [[clang::noalloc]]; // expected-note {{overridden virtual function is here}}
+	virtual void nolock() noexcept [[clang::nolock]];
+	virtual void noalloc() noexcept [[clang::noalloc]];
 };
 
 struct Derived : public Base {
 	void f1() [[clang::nolock]] override;
-	void nolock() noexcept override; // expected-warning {{attribute 'nolock' on overriding function does not match base version}}
-	void noalloc() noexcept override; // expected-warning {{attribute 'noalloc' on overriding function does not match base version}}
+	void nolock() noexcept override;
+	void noalloc() noexcept override;
 };
 #endif // __cplusplus
 
@@ -89,26 +108,10 @@ void f2();
 #endif
 // Note: we verify that the attribute is actually seen during the constraints tests.
 
-
-// Ensure that the redeclaration's attribute is seen and diagnosed correctly.
-
-// void f2() {
-// 	static int x;
-// }
-// void f2() [[clang::nolock]];
-// 
-// void f3() [[clang::nolock]] {
-// 	f2();
-// }
-
-#if 0
-int f2();
-// redeclaration with a stronger constraint is OK.
-int f2() [[clang::nolock]]; // e xpected-note {{previous declaration is here}}
-int f2() { return 42; } // e xpected-warning {{attribute 'nolock' on function does not match previous declaration}}
-
-int f3();
-// redeclaration with a stronger constraint is OK.
-int f3() [[clang::noalloc]]; // e xpected-note {{previous declaration is here}}
-int f3() { return 42; } // e xpected-warning {{attribute 'noalloc' on function does not match previous declaration}}
-#endif
+// --- OVERLOADS ---
+#ifdef __cplusplus
+struct S {
+	void foo(); // expected-note {{previous declaration is here}}
+	void foo(); // expected-error {{class member cannot be redeclared}}
+};
+#endif // __cplusplus
diff --git a/clang/test/Sema/attr-nolock-syntax.cpp b/clang/test/Sema/attr-nolock-syntax.cpp
index 2c0d71ba93ddf0..8deb3e88cc7d25 100644
--- a/clang/test/Sema/attr-nolock-syntax.cpp
+++ b/clang/test/Sema/attr-nolock-syntax.cpp
@@ -53,6 +53,15 @@ void nl2() [[clang::noalloc]] [[clang::nolock]];
 decltype(nl1) nl3;
 // CHECK: FunctionDecl {{.*}} nl3 'decltype(nl1)':'void () __attribute__((clang_nolock))'
 
+// Attribute propagates from base class virtual method to overrides.
+struct Base {
+	virtual void nl_method() [[clang::nolock]];
+};
+struct Derived : public Base {
+	void nl_method() override;
+	// CHECK: CXXMethodDecl {{.*}} nl_method 'void () __attribute__((clang_nolock))'
+};
+
 // --- Blocks ---
 
 // On the type of the VarDecl holding a BlockDecl
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
index ab8cf57d69ed0c..914c4d09764ee8 100644
--- a/clang/test/Sema/attr-nolock-wip.cpp
+++ b/clang/test/Sema/attr-nolock-wip.cpp
@@ -4,36 +4,82 @@
 #error "the 'nolock' attribute is not available"
 #endif
 
-// ============================================================================
 
-void f2(int);
-void f2(int) [[clang::nolock]]; // expected-note {{previous declaration is here}}
-void f2(int); // expected-warning {{attribute 'nolock' on function does not match previous declaration}}
+// The diagnostic for inference not following a non-inline method should override
+// the one for a virtual method.
 
-// ============================================================================
+struct HasVirtual {
+	virtual ~HasVirtual() = default;
+	virtual void method();
+};
+
+void nl999(HasVirtual& x) [[clang::nolock]] {
+	x.method();
+}
 
-#if 0
-// https://github.com/llvm/llvm-project/pull/84983#issuecomment-1994978033
 
-// the bug where AttributedType sugar gets lost on lambdas (when the "inferred" return type gets
-// converted to a concrete one) happens here and the nolock(false) attribute is lost from h.
 
-template <class T>
-void f(T a) [[clang::nolock]] { a(); }
+#if 0
+	using nl_sugar = int (*)(int) [[clang::nolock]];
+
+	void receives_fp_nl(nl_sugar fp) {
+	}
+	
+	int callback(int) noexcept [[clang::nolock]];
 
-void m()
+void type_conversions_2()
 {
-	auto g = []() [[clang::nolock]] {
+	auto receives_fp = [](void (*fp)()) {
 	};
 	
-	auto h = []() [[clang::nolock(false)]] {
-	};
+	//auto receives_fp_nl = [](void (*fp)() [[clang::nolock]]) {
+	//};
 
-	f(g);
-	f(h);
+	auto ne = +[]() noexcept {};
+	auto nl = +[]() [[clang::nolock]] {};
+	//auto nl_ne = +[](int x) noexcept [[clang::nolock]] -> int  { return x; };
+	
+	receives_fp(ne);
+	receives_fp(nl);
+// 	receives_fp(nl_ne);
+	
+	receives_fp_nl(callback);
 }
 #endif
 
+#if 0
+struct S {
+	void foo();
+	// void foo() noexcept; // error, redeclaration
+	// void foo() [[clang::nolock]]; // error, redeclaration
+	
+	using FP = void (*)();
+	using FPNE = void (*)() noexcept;
+	using FPNL = void (*)() [[clang::nolock]];
+	
+	void bar(FP x);
+	void bar(FPNE x);	// This is a distinct overload
+	void bar(FPNL x);	// This is a distinct overload
+};
+#endif
+
+// ============================================================================
+
+#if 0
+#define RT_UNSAFE_BEGIN(reason)                                   \
+	_Pragma("clang diagnostic push")                                 \
+	_Pragma("clang diagnostic ignored \"-Wunknown-warning-option\"") \
+	_Pragma("clang diagnostic ignored \"-Wfunction-effects\"")
+
+#define RT_UNSAFE_END \
+	_Pragma("clang diagnostic pop")
+
+#define RT_UNSAFE(...)  \
+	RT_UNSAFE_BEGIN("") \
+	__VA_ARGS__            \
+	RT_UNSAFE_END
+#endif
+
 // ============================================================================
 
 #if 0

>From 525962e73ab9dd031a7afefa8547a0353887d3bd Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 3 Apr 2024 05:54:16 -0700
Subject: [PATCH 19/40] Mass renaming: nolock/noalloc ->
 nonblocking/nonallocating

---
 clang/include/clang/AST/Type.h                |  18 +--
 clang/include/clang/Basic/Attr.td             |  20 ++--
 clang/include/clang/Basic/AttrDocs.td         |  11 +-
 clang/include/clang/Basic/DiagnosticGroups.td |   2 +-
 .../clang/Basic/DiagnosticSemaKinds.td        |   2 +-
 clang/lib/AST/ASTContext.cpp                  |   2 +-
 clang/lib/AST/Type.cpp                        |  54 ++++-----
 clang/lib/AST/TypePrinter.cpp                 |   8 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp      |   2 +-
 clang/lib/Sema/SemaType.cpp                   |  71 ++++++------
 clang/test/Sema/attr-nolock-constraints.mm    | 106 +++++++++---------
 clang/test/Sema/attr-nolock-sema.cpp          |  90 +++++++--------
 clang/test/Sema/attr-nolock-syntax.cpp        |  82 +++++++-------
 clang/test/Sema/attr-nolock-wip.cpp           |  26 ++---
 14 files changed, 251 insertions(+), 243 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index fb1c324ef6d3ae..cdfeb8eb715399 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4448,8 +4448,8 @@ class FunctionEffect {
   /// Identifies the particular type of effect.
   enum class Type {
     None = 0,
-    NoLockTrue,
-    NoAllocTrue,
+    NonBlocking,
+    NonAllocating,
   };
 
   /// Flags describing behaviors of the effect.
@@ -4458,16 +4458,17 @@ class FunctionEffect {
   // would OR together the bits of multiple effects.)
   using Flags = unsigned;
   enum FlagBit : unsigned {
-    // Some effects require verification, e.g. nolock(true); others might not?
-    // (no example yet; TODO: maybe always true, vestigial from nolock(false)).
+    // Some effects require verification, e.g. nonblocking(true); others might
+    // not? (no example yet; TODO: maybe always true, vestigial from
+    // nonblocking(false)).
     FE_RequiresVerification = 0x1,
 
     // Does this effect want to verify all function calls originating in
     // functions having this effect? TODO: maybe always true, vestigial.
     FE_VerifyCalls = 0x2,
 
-    // Can verification inspect callees' implementations? (e.g. nolock: yes,
-    // tcb+types: no)
+    // Can verification inspect callees' implementations? (e.g. nonblocking:
+    // yes, tcb+types: no)
     FE_InferrableOnCallees = 0x4,
 
     // Language constructs which effects can diagnose as disallowed.
@@ -4515,7 +4516,7 @@ class FunctionEffect {
   /// Flags describing behaviors of the effect.
   Flags flags() const { return Flags_; }
 
-  /// The description printed in diagnostics, e.g. 'nolock'.
+  /// The description printed in diagnostics, e.g. 'nonblocking'.
   StringRef name() const;
 
   /// A hashable representation.
@@ -4548,7 +4549,8 @@ class FunctionEffect {
   /// on an implicit function like a default constructor.
   ///
   /// This is only used if the effect has FE_InferrableOnCallees flag set.
-  /// Example: This allows nolock(false) to prevent inference for the function.
+  /// Example: This allows nonblocking(false) to prevent inference for the
+  /// function.
   bool canInferOnFunction(QualType QT, const TypeSourceInfo *FType) const;
 
   // Called if FE_VerifyCalls flag is set; return false for success. When true
diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 7fe7b0eae76682..9f38a098384348 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1402,21 +1402,21 @@ def CXX11NoReturn : InheritableAttr {
   let Documentation = [CXX11NoReturnDocs];
 }
 
-def NoLock : TypeAttr {
-  let Spellings = [CXX11<"clang", "nolock">,
-                   C23<"clang", "nolock">,
-                   GNU<"clang_nolock">];
+def NonBlocking : TypeAttr {
+  let Spellings = [CXX11<"clang", "nonblocking">,
+                   C23<"clang", "nonblocking">,
+                   GNU<"clang_nonblocking">];
 
   let Args = [DefaultBoolArgument<"Cond", /*default*/1>];
-  let Documentation = [NoLockNoAllocDocs];
+  let Documentation = [NonBlockingNonAllocatingDocs];
 }
 
-def NoAlloc : TypeAttr {
-  let Spellings = [CXX11<"clang", "noalloc">,
-                   C23<"clang", "noalloc">,
-                   GNU<"clang_noalloc">];
+def NonAllocating : TypeAttr {
+  let Spellings = [CXX11<"clang", "nonallocating">,
+                   C23<"clang", "nonallocating">,
+                   GNU<"clang_nonallocating">];
   let Args = [DefaultBoolArgument<"Cond", /*default*/1>];
-  let Documentation = [NoLockNoAllocDocs];
+  let Documentation = [NonBlockingNonAllocatingDocs];
 }
 
 // Similar to CUDA, OpenCL attributes do not receive a [[]] spelling because
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index ee70c17d62190c..4b7b40feaaf26e 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -1,4 +1,5 @@
-//==--- AttrDocs.td - Attribute documentation ----------------------------===//
+  
+  //==--- AttrDocs.td - Attribute documentation ----------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -8045,17 +8046,17 @@ requirement:
   }];
 }
 
-def NoLockNoAllocDocs : Documentation {
+def NonBlockingNonAllocatingDocs : Documentation {
   let Category = DocCatType;
   let Content = [{
-The ``nolock`` and ``noalloc`` attributes can be attached to functions, blocks,
+The ``nonblocking`` and ``nonallocating`` attributes can be attached to functions, blocks,
 function pointers, lambdas, and member functions. The attributes identify code
 which must not allocate memory or lock, and the compiler uses the attributes to
 verify these requirements.
 
-Like ``noexcept``, ``nolock`` and ``noalloc`` have an optional argument, a
+Like ``noexcept``, ``nonblocking`` and ``nonallocating`` have an optional argument, a
 compile-time constant boolean expression. By default, the argument is true, so
-``[[clang::nolock(true)]]`` is equivalent to ``[[clang::nolock]]``, and declares
+``[[clang::nonblocking(true)]]`` is equivalent to ``[[clang::nonblocking]]``, and declares
 the function type as never locking.
 
 TODO: how much of the RFC to include here? Make it a separate page?
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index a1bb05471dd6c7..59eac4e2c14427 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1515,7 +1515,7 @@ def UnsafeBufferUsageInContainer : DiagGroup<"unsafe-buffer-usage-in-container">
 def UnsafeBufferUsage : DiagGroup<"unsafe-buffer-usage", [UnsafeBufferUsageInContainer]>;
 
 // Warnings and notes related to the function effects system underlying
-// the nolock and noalloc attributes.
+// the nonblocking and nonallocating attributes.
 def FunctionEffects : DiagGroup<"function-effects">;
 
 // Warnings and notes InstallAPI verification.
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index ef57eb9ad2cde4..f2cf601b95f370 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10870,7 +10870,7 @@ def warn_func_effect_false_on_type : Warning<
 def note_func_effect_from_template : Note<
   "in template expansion here">;
 
-// spoofing nolock/noalloc
+// spoofing nonblocking/nonallocating
 def warn_invalid_add_func_effects : Warning<
   "attribute '%0' should not be added via type conversion">,
   InGroup<FunctionEffects>;
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 9c3913534692c1..82bd24f49acd87 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -10517,7 +10517,7 @@ QualType ASTContext::mergeFunctionTypes(QualType lhs, QualType rhs,
     if (lproto->getMethodQuals() != rproto->getMethodQuals())
       return {};
 
-    // TODO: (nolock) Does anything need to be done with FunctionEffects?
+    // TODO: (nonblocking) Does anything need to be done with FunctionEffects?
 
     SmallVector<FunctionProtoType::ExtParameterInfo, 4> newParamInfos;
     bool canUseLeft, canUseRight;
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 3517979ddce951..4455a06421a623 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5029,14 +5029,14 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
 FunctionEffect::FunctionEffect(Type T)
     : Type_(unsigned(T)), Flags_(0), Padding(0) {
   switch (T) {
-  case Type::NoLockTrue:
+  case Type::NonBlocking:
     Flags_ = FE_RequiresVerification | FE_VerifyCalls | FE_InferrableOnCallees |
              FE_ExcludeThrow | FE_ExcludeCatch | FE_ExcludeObjCMessageSend |
              FE_ExcludeStaticLocalVars | FE_ExcludeThreadLocalVars;
     break;
 
-  case Type::NoAllocTrue:
-    // Same as NoLockTrue, except without FE_ExcludeStaticLocalVars
+  case Type::NonAllocating:
+    // Same as NonBlocking, except without FE_ExcludeStaticLocalVars
     Flags_ = FE_RequiresVerification | FE_VerifyCalls | FE_InferrableOnCallees |
              FE_ExcludeThrow | FE_ExcludeCatch | FE_ExcludeObjCMessageSend |
              FE_ExcludeThreadLocalVars;
@@ -5050,10 +5050,10 @@ StringRef FunctionEffect::name() const {
   switch (type()) {
   default:
     return "";
-  case Type::NoLockTrue:
-    return "nolock";
-  case Type::NoAllocTrue:
-    return "noalloc";
+  case Type::NonBlocking:
+    return "nonblocking";
+  case Type::NonAllocating:
+    return "nonallocating";
   }
 }
 
@@ -5063,18 +5063,18 @@ bool FunctionEffect::diagnoseConversion(bool Adding, QualType OldType,
                                         FunctionEffectSet NewFX) const {
 
   switch (type()) {
-  case Type::NoAllocTrue:
-    // noalloc can't be added (spoofed) during a conversion, unless we have
-    // nolock
+  case Type::NonAllocating:
+    // nonallocating can't be added (spoofed) during a conversion, unless we
+    // have nonblocking
     if (Adding) {
       for (const auto &Effect : OldFX) {
-        if (Effect.type() == Type::NoLockTrue)
+        if (Effect.type() == Type::NonBlocking)
           return false;
       }
     }
     [[fallthrough]];
-  case Type::NoLockTrue:
-    // nolock can't be added (spoofed) during a conversion
+  case Type::NonBlocking:
+    // nonblocking can't be added (spoofed) during a conversion
     return Adding;
   default:
     break;
@@ -5088,9 +5088,9 @@ bool FunctionEffect::diagnoseRedeclaration(bool Adding,
                                            const FunctionDecl &NewFunction,
                                            FunctionEffectSet NewFX) const {
   switch (type()) {
-  case Type::NoAllocTrue:
-  case Type::NoLockTrue:
-    // nolock/noalloc can't be removed in a redeclaration
+  case Type::NonAllocating:
+  case Type::NonBlocking:
+    // nonblocking/nonallocating can't be removed in a redeclaration
     // adding -> false, removing -> true (diagnose)
     return !Adding;
   default:
@@ -5103,9 +5103,9 @@ FunctionEffect::OverrideResult FunctionEffect::diagnoseMethodOverride(
     bool Adding, const CXXMethodDecl &OldMethod, FunctionEffectSet OldFX,
     const CXXMethodDecl &NewMethod, FunctionEffectSet NewFX) const {
   switch (type()) {
-  case Type::NoAllocTrue:
-  case Type::NoLockTrue:
-    // nolock/noalloc can't be removed from an override
+  case Type::NonAllocating:
+  case Type::NonBlocking:
+    // nonblocking/nonallocating can't be removed from an override
     // adding -> false, removing -> true (diagnose)
     return Adding ? OverrideResult::Ignore : OverrideResult::Propagate;
   default:
@@ -5117,11 +5117,11 @@ FunctionEffect::OverrideResult FunctionEffect::diagnoseMethodOverride(
 bool FunctionEffect::canInferOnFunction(QualType QT,
                                         const TypeSourceInfo *FType) const {
   switch (type()) {
-  case Type::NoAllocTrue:
-  case Type::NoLockTrue: {
-    // Does the sugar have nolock(false) / noalloc(false) ?
-    if (QT->hasAttr(type() == Type::NoLockTrue ? attr::Kind::NoLock
-                                               : attr::Kind::NoAlloc)) {
+  case Type::NonAllocating:
+  case Type::NonBlocking: {
+    // Does the sugar have nonblocking(false) / nonallocating(false) ?
+    if (QT->hasAttr(type() == Type::NonBlocking ? attr::Kind::NonBlocking
+                                                : attr::Kind::NonAllocating)) {
       return false;
     }
 
@@ -5137,14 +5137,14 @@ bool FunctionEffect::canInferOnFunction(QualType QT,
 bool FunctionEffect::diagnoseFunctionCall(bool Direct,
                                           FunctionEffectSet CalleeFX) const {
   switch (type()) {
-  case Type::NoAllocTrue:
-  case Type::NoLockTrue: {
+  case Type::NonAllocating:
+  case Type::NonBlocking: {
     const Type CallerType = type();
     for (const auto &Effect : CalleeFX) {
       const Type ET = Effect.type();
       // Does callee have same or stronger constraint?
       if (ET == CallerType ||
-          (CallerType == Type::NoAllocTrue && ET == Type::NoLockTrue)) {
+          (CallerType == Type::NonAllocating && ET == Type::NonBlocking)) {
         return false; // no diagnostic
       }
     }
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index c69e3412f127dd..16290808ee5080 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -1996,11 +1996,11 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   // Nothing to print for this attribute.
   case attr::HLSLParamModifier:
     break;
-  case attr::NoLock:
-    OS << "clang_nolock(false)";
+  case attr::NonBlocking:
+    OS << "clang_nonblocking(false)";
     break;
-  case attr::NoAlloc:
-    OS << "clang_noalloc(false)";
+  case attr::NonAllocating:
+    OS << "clang_nonallocating(false)";
     break;
   }
   OS << "))";
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 10228715ea1bb9..9b222595a7302c 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2765,7 +2765,7 @@ class CompleteFunctionAnalysis {
 };
 
 /*
-        TODO: nolock and noalloc imply noexcept
+        TODO: nonblocking and nonallocating imply noexcept
         if (auto* Method = dyn_cast<CXXMethodDecl>(CInfo.CDecl)) {
           if (Method->getType()->castAs<FunctionProtoType>()->canThrow()
               != clang::CT_Cannot) {
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 47689d7852131a..535663f77a4a28 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -145,8 +145,8 @@ static void diagnoseBadTypeAttribute(Sema &S, const ParsedAttr &attr,
 #define FUNCTION_TYPE_ATTRS_CASELIST                                           \
   case ParsedAttr::AT_NSReturnsRetained:                                       \
   case ParsedAttr::AT_NoReturn:                                                \
-  case ParsedAttr::AT_NoLock:                                                  \
-  case ParsedAttr::AT_NoAlloc:                                                 \
+  case ParsedAttr::AT_NonBlocking:                                             \
+  case ParsedAttr::AT_NonAllocating:                                           \
   case ParsedAttr::AT_Regparm:                                                 \
   case ParsedAttr::AT_CmseNSCall:                                              \
   case ParsedAttr::AT_ArmStreaming:                                            \
@@ -214,10 +214,10 @@ namespace {
     /// validating that noderef was used on a pointer or array.
     bool parsedNoDeref;
 
-    // Flags to diagnose illegal permutations of nolock(cond) and noalloc(cond).
-    // Manual logic for finding previous attributes would be more complex,
-    // unless we transformed nolock/noalloc(false) into distinct separate
-    // attributes from the ones which are parsed.
+    // Flags to diagnose illegal permutations of nonblocking(cond) and
+    // nonallocating(cond). Manual logic for finding previous attributes would
+    // be more complex, unless we transformed nonblocking/nonallocating(false)
+    // into distinct separate attributes from the ones which are parsed.
     BoolAttrState parsedNolock : 2;
     BoolAttrState parsedNoalloc : 2;
 
@@ -7977,14 +7977,15 @@ static Attr *getCCTypeAttr(ASTContext &Ctx, ParsedAttr &Attr) {
   llvm_unreachable("unexpected attribute kind!");
 }
 
-static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
-                                        ParsedAttr &PAttr, QualType &type,
-                                        FunctionTypeUnwrapper &unwrapped) {
+static bool
+handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
+                                       ParsedAttr &PAttr, QualType &type,
+                                       FunctionTypeUnwrapper &unwrapped) {
   // Delay if this is not a function type.
   if (!unwrapped.isFunctionType())
     return false;
 
-  const bool isNoLock = PAttr.getKind() == ParsedAttr::AT_NoLock;
+  const bool isNonBlocking = PAttr.getKind() == ParsedAttr::AT_NonBlocking;
   Sema &S = state.getSema();
 
   // Require FunctionProtoType
@@ -8017,58 +8018,62 @@ static bool handleNoLockNoAllocTypeAttr(TypeProcessingState &state,
     return true;
   };
 
-  // check nolock(true) against nolock(false), and same for noalloc
+  // check nonblocking(true) against nonblocking(false), and same for
+  // nonallocating
   const BoolAttrState newState =
       Cond ? BoolAttrState::True : BoolAttrState::False;
   const BoolAttrState oppositeNewState =
       Cond ? BoolAttrState::False : BoolAttrState::True;
-  if (isNoLock) {
+  if (isNonBlocking) {
     if (state.getParsedNolock() == oppositeNewState) {
-      return incompatible("nolock(true)", "nolock(false)");
+      return incompatible("nonblocking(true)", "nonblocking(false)");
     }
-    // also check nolock(true) against noalloc(false)
+    // also check nonblocking(true) against nonallocating(false)
     if (Cond && state.getParsedNoalloc() == BoolAttrState::False) {
-      return incompatible("nolock(true)", "noalloc(false)");
+      return incompatible("nonblocking(true)", "nonallocating(false)");
     }
     state.setParsedNolock(newState);
   } else {
     if (state.getParsedNoalloc() == oppositeNewState) {
-      return incompatible("noalloc(true)", "noalloc(false)");
+      return incompatible("nonallocating(true)", "nonallocating(false)");
     }
-    // also check nolock(true) against noalloc(false)
+    // also check nonblocking(true) against nonallocating(false)
     if (state.getParsedNolock() == BoolAttrState::True) {
       if (!Cond) {
-        return incompatible("nolock(true)", "noalloc(false)");
+        return incompatible("nonblocking(true)", "nonallocating(false)");
       }
-      // Ignore noalloc(true) since we already have nolock(true).
+      // Ignore nonallocating(true) since we already have nonblocking(true).
       return true;
     }
     state.setParsedNoalloc(newState);
   }
 
   if (!Cond) {
-    // nolock(false) and noalloc(false) are represented as sugar, with
-    // AttributedType
+    // nonblocking(false) and nonallocating(false) are represented as sugar,
+    // with AttributedType
     Attr *A = nullptr;
-    if (isNoLock) {
-      A = NoLockAttr::Create(S.Context, false);
+    if (isNonBlocking) {
+      A = NonBlockingAttr::Create(S.Context, false);
     } else {
-      A = NoAllocAttr::Create(S.Context, false);
+      A = NonAllocatingAttr::Create(S.Context, false);
     }
     type = state.getAttributedType(A, type, type);
     return true;
   }
 
-  // nolock(true) and noalloc(true) are represented as FunctionEffects, in a
-  // FunctionEffectSet attached to a FunctionProtoType.
-  const FunctionEffect NewEffect(isNoLock ? FunctionEffect::Type::NoLockTrue
-                                          : FunctionEffect::Type::NoAllocTrue);
+  // nonblocking(true) and nonallocating(true) are represented as
+  // FunctionEffects, in a FunctionEffectSet attached to a FunctionProtoType.
+  const FunctionEffect NewEffect(isNonBlocking
+                                     ? FunctionEffect::Type::NonBlocking
+                                     : FunctionEffect::Type::NonAllocating);
 
   MutableFunctionEffectSet NewFX(NewEffect);
   if (EPI.FunctionEffects) {
-    // Preserve any previous effects - except noalloc, when we are adding nolock
+    // Preserve any previous effects - except nonallocating, when we are adding
+    // nonblocking
     for (const auto &Effect : EPI.FunctionEffects) {
-      if (!(isNoLock && Effect.type() == FunctionEffect::Type::NoAllocTrue))
+      if (!(isNonBlocking &&
+            Effect.type() == FunctionEffect::Type::NonAllocating))
         NewFX.insert(Effect);
     }
   }
@@ -8394,9 +8399,9 @@ static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
     return true;
   }
 
-  if (attr.getKind() == ParsedAttr::AT_NoLock ||
-      attr.getKind() == ParsedAttr::AT_NoAlloc) {
-    return handleNoLockNoAllocTypeAttr(state, attr, type, unwrapped);
+  if (attr.getKind() == ParsedAttr::AT_NonBlocking ||
+      attr.getKind() == ParsedAttr::AT_NonAllocating) {
+    return handleNonBlockingNonAllocatingTypeAttr(state, attr, type, unwrapped);
   }
 
   // Delay if the type didn't work out to a function.
diff --git a/clang/test/Sema/attr-nolock-constraints.mm b/clang/test/Sema/attr-nolock-constraints.mm
index e52b50eac519f4..4be3f8c95c9ad9 100644
--- a/clang/test/Sema/attr-nolock-constraints.mm
+++ b/clang/test/Sema/attr-nolock-constraints.mm
@@ -2,95 +2,95 @@
 // These are in a separate file because errors (e.g. incompatible attributes) currently prevent
 // the AnalysisBasedWarnings pass from running at all.
 
-#if !__has_attribute(clang_nolock)
-#error "the 'nolock' attribute is not available"
+#if !__has_attribute(clang_nonblocking)
+#error "the 'nonblocking' attribute is not available"
 #endif
 
 // --- CONSTRAINTS ---
 
-void nl1() [[clang::nolock]]
+void nl1() [[clang::nonblocking]]
 {
-	auto* pInt = new int; // expected-warning {{'nolock' function must not allocate or deallocate memory}}
+	auto* pInt = new int; // expected-warning {{'nonblocking' function must not allocate or deallocate memory}}
 }
 
-void nl2() [[clang::nolock]]
+void nl2() [[clang::nonblocking]]
 {
-	static int global; // expected-warning {{'nolock' function must not have static locals}}
+	static int global; // expected-warning {{'nonblocking' function must not have static locals}}
 }
 
-void nl3() [[clang::nolock]]
+void nl3() [[clang::nonblocking]]
 {
 	try {
-		throw 42; // expected-warning {{'nolock' function must not throw or catch exceptions}}
+		throw 42; // expected-warning {{'nonblocking' function must not throw or catch exceptions}}
 	}
-	catch (...) { // expected-warning {{'nolock' function must not throw or catch exceptions}}
+	catch (...) { // expected-warning {{'nonblocking' function must not throw or catch exceptions}}
 	}
 }
 
 void nl4_inline() {}
-void nl4_not_inline(); // expected-note {{function cannot be inferred 'nolock' because it has no definition in this translation unit}}
+void nl4_not_inline(); // expected-note {{function cannot be inferred 'nonblocking' because it has no definition in this translation unit}}
 
-void nl4() [[clang::nolock]]
+void nl4() [[clang::nonblocking]]
 {
 	nl4_inline(); // OK
-	nl4_not_inline(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
+	nl4_not_inline(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
 }
 
 
 struct HasVirtual {
-	virtual void unsafe(); // expected-note {{virtual method cannot be inferred 'nolock'}}
+	virtual void unsafe(); // expected-note {{virtual method cannot be inferred 'nonblocking'}}
 };
 
-void nl5() [[clang::nolock]]
+void nl5() [[clang::nonblocking]]
 {
  	HasVirtual hv;
- 	hv.unsafe(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
+ 	hv.unsafe(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
 }
 
-void nl6_unsafe(); // expected-note {{function cannot be inferred 'nolock' because it has no definition in this translation unit}}
+void nl6_unsafe(); // expected-note {{function cannot be inferred 'nonblocking' because it has no definition in this translation unit}}
 void nl6_transitively_unsafe()
 {
-	nl6_unsafe(); // expected-note {{function cannot be inferred 'nolock' because it calls non-'nolock' function}}
+	nl6_unsafe(); // expected-note {{function cannot be inferred 'nonblocking' because it calls non-'nonblocking' function}}
 }
 
-void nl6() [[clang::nolock]]
+void nl6() [[clang::nonblocking]]
 {
-	nl6_transitively_unsafe(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
+	nl6_transitively_unsafe(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
 }
 
 thread_local int tl_var{ 42 };
 
-bool tl_test() [[clang::nolock]]
+bool tl_test() [[clang::nonblocking]]
 {
-	return tl_var > 0; // expected-warning {{'nolock' function must not use thread-local variables}}
+	return tl_var > 0; // expected-warning {{'nonblocking' function must not use thread-local variables}}
 }
 
 void nl7()
 {
 	// Make sure we verify blocks
-	auto blk = ^() [[clang::nolock]] {
-		throw 42; // expected-warning {{'nolock' function must not throw or catch exceptions}}
+	auto blk = ^() [[clang::nonblocking]] {
+		throw 42; // expected-warning {{'nonblocking' function must not throw or catch exceptions}}
 	};
 }
 
 void nl8()
 {
 	// Make sure we verify lambdas
-	auto lambda = []() [[clang::nolock]] {
-		throw 42; // expected-warning {{'nolock' function must not throw or catch exceptions}}
+	auto lambda = []() [[clang::nonblocking]] {
+		throw 42; // expected-warning {{'nonblocking' function must not throw or catch exceptions}}
 	};
 }
 
 // Make sure template expansions are found and verified.
 	template <typename T>
 	struct Adder {
-		static T add_explicit(T x, T y) [[clang::nolock]]
+		static T add_explicit(T x, T y) [[clang::nonblocking]]
 		{
-			return x + y; // expected-warning {{'nolock' function must not call non-'nolock' function}}
+			return x + y; // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
 		}
 		static T add_implicit(T x, T y)
 		{
-			return x + y; // expected-note {{function cannot be inferred 'nolock' because it calls non-'nolock' function}}
+			return x + y; // expected-note {{function cannot be inferred 'nonblocking' because it calls non-'nonblocking' function}}
 		}
 	};
 
@@ -98,7 +98,7 @@ static T add_implicit(T x, T y)
 		friend Stringy operator+(const Stringy& x, const Stringy& y)
 		{
 			// Do something inferably unsafe
-			auto* z = new char[42]; // expected-note {{function cannot be inferred 'nolock' because it allocates/deallocates memory}}
+			auto* z = new char[42]; // expected-note {{function cannot be inferred 'nonblocking' because it allocates/deallocates memory}}
 			return {};
 		}
 	};
@@ -107,82 +107,82 @@ static T add_implicit(T x, T y)
 		friend Stringy2 operator+(const Stringy2& x, const Stringy2& y)
 		{
 			// Do something inferably unsafe
-			throw 42; // expected-note {{function cannot be inferred 'nolock' because it throws or catches exceptions}}
+			throw 42; // expected-note {{function cannot be inferred 'nonblocking' because it throws or catches exceptions}}
 		}
 	};
 
-void nl9() [[clang::nolock]]
+void nl9() [[clang::nonblocking]]
 {
 	Adder<int>::add_explicit(1, 2);
 	Adder<int>::add_implicit(1, 2);
 
 	Adder<Stringy>::add_explicit({}, {}); // expected-note {{in template expansion here}}
-	Adder<Stringy2>::add_implicit({}, {}); // expected-warning {{'nolock' function must not call non-'nolock' function}} \
+	Adder<Stringy2>::add_implicit({}, {}); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}} \
 		expected-note {{in template expansion here}}
 }
 
 void nl10(
-	void (*fp1)(), // expected-note {{function pointer cannot be inferred 'nolock'}}
-	void (*fp2)() [[clang::nolock]]
-	) [[clang::nolock]]
+	void (*fp1)(), // expected-note {{function pointer cannot be inferred 'nonblocking'}}
+	void (*fp2)() [[clang::nonblocking]]
+	) [[clang::nonblocking]]
 {
-	fp1(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
+	fp1(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
 	fp2();
 }
 
-// Interactions with nolock(false)
-void nl11_no_inference() [[clang::nolock(false)]] // expected-note {{function does not permit inference of 'nolock'}}
+// Interactions with nonblocking(false)
+void nl11_no_inference() [[clang::nonblocking(false)]] // expected-note {{function does not permit inference of 'nonblocking'}}
 {
 }
 
-void nl11() [[clang::nolock]]
+void nl11() [[clang::nonblocking]]
 {
-	nl11_no_inference(); // expected-warning {{'nolock' function must not call non-'nolock' function}}
+	nl11_no_inference(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
 }
 
 // Verify that when attached to a redeclaration, the attribute successfully attaches.
 void nl12() {
-	static int x; // expected-warning {{'nolock' function must not have static locals}}
+	static int x; // expected-warning {{'nonblocking' function must not have static locals}}
 }
-void nl12() [[clang::nolock]];
-void nl13() [[clang::nolock]] { nl12(); }
+void nl12() [[clang::nonblocking]];
+void nl13() [[clang::nonblocking]] { nl12(); }
 
 // Objective-C
 @interface OCClass
 - (void)method;
 @end
 
-void nl14(OCClass *oc) [[clang::nolock]] {
-	[oc method]; // expected-warning {{'nolock' function must not access an ObjC method or property}}
+void nl14(OCClass *oc) [[clang::nonblocking]] {
+	[oc method]; // expected-warning {{'nonblocking' function must not access an ObjC method or property}}
 }
 void nl15(OCClass *oc) {
-	[oc method]; // expected-note {{function cannot be inferred 'nolock' because it accesses an ObjC method or property}}
+	[oc method]; // expected-note {{function cannot be inferred 'nonblocking' because it accesses an ObjC method or property}}
 }
-void nl16(OCClass *oc) [[clang::nolock]] {
-	nl15(oc); // expected-warning {{'nolock' function must not call non-'nolock' function 'nl15'}}
+void nl16(OCClass *oc) [[clang::nonblocking]] {
+	nl15(oc); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function 'nl15'}}
 }
 
 // C++ member function pointers
 struct PTMFTester {
-	typedef void (PTMFTester::*ConvertFunction)() [[clang::nolock]];
+	typedef void (PTMFTester::*ConvertFunction)() [[clang::nonblocking]];
 
-	void convert() [[clang::nolock]];
+	void convert() [[clang::nonblocking]];
 
 	ConvertFunction mConvertFunc;
 };
 
-void PTMFTester::convert() [[clang::nolock]]
+void PTMFTester::convert() [[clang::nonblocking]]
 {
 	(this->*mConvertFunc)();
 }
 
 // Block variables
-void nl17(void (^blk)() [[clang::nolock]]) [[clang::nolock]] {
+void nl17(void (^blk)() [[clang::nonblocking]]) [[clang::nonblocking]] {
 	blk();
 }
 
 // References to blocks
-void nl18(void (^block)() [[clang::nolock]]) [[clang::nolock]]
+void nl18(void (^block)() [[clang::nonblocking]]) [[clang::nonblocking]]
 {
 	auto &ref = block;
 	ref();
diff --git a/clang/test/Sema/attr-nolock-sema.cpp b/clang/test/Sema/attr-nolock-sema.cpp
index 98a11067305d56..1d7881b30411af 100644
--- a/clang/test/Sema/attr-nolock-sema.cpp
+++ b/clang/test/Sema/attr-nolock-sema.cpp
@@ -1,74 +1,74 @@
 // RUN: %clang_cc1 -fsyntax-only -fblocks -fcxx-exceptions -verify %s
 // RUN: %clang_cc1 -fsyntax-only -fblocks -verify -x c -std=c23 %s
 
-#if !__has_attribute(clang_nolock)
-#error "the 'nolock' attribute is not available"
+#if !__has_attribute(clang_nonblocking)
+#error "the 'nonblocking' attribute is not available"
 #endif
 
 // --- ATTRIBUTE SYNTAX: SUBJECTS ---
 
-int nl_var [[clang::nolock]]; // expected-warning {{'nolock' only applies to function types; type here is 'int'}}
-struct nl_struct {} [[clang::nolock]]; // expected-warning {{attribute 'nolock' is ignored, place it after "struct" to apply attribute to type declaration}}
-struct [[clang::nolock]] nl_struct2 {}; // expected-error {{'nolock' attribute cannot be applied to a declaration}}
+int nl_var [[clang::nonblocking]]; // expected-warning {{'nonblocking' only applies to function types; type here is 'int'}}
+struct nl_struct {} [[clang::nonblocking]]; // expected-warning {{attribute 'nonblocking' is ignored, place it after "struct" to apply attribute to type declaration}}
+struct [[clang::nonblocking]] nl_struct2 {}; // expected-error {{'nonblocking' attribute cannot be applied to a declaration}}
 
 // --- ATTRIBUTE SYNTAX: COMBINATIONS ---
-// Check invalid combinations of nolock/noalloc attributes
+// Check invalid combinations of nonblocking/nonallocating attributes
 
-void nl_true_false_1() [[clang::nolock(true)]] [[clang::nolock(false)]]; // expected-error {{nolock(true) and nolock(false) attributes are not compatible}}
-void nl_true_false_2() [[clang::nolock(false)]] [[clang::nolock(true)]]; // expected-error {{nolock(true) and nolock(false) attributes are not compatible}}
+void nl_true_false_1() [[clang::nonblocking(true)]] [[clang::nonblocking(false)]]; // expected-error {{nonblocking(true) and nonblocking(false) attributes are not compatible}}
+void nl_true_false_2() [[clang::nonblocking(false)]] [[clang::nonblocking(true)]]; // expected-error {{nonblocking(true) and nonblocking(false) attributes are not compatible}}
 
-void na_true_false_1() [[clang::noalloc(true)]] [[clang::noalloc(false)]]; // expected-error {{noalloc(true) and noalloc(false) attributes are not compatible}}
-void na_true_false_2() [[clang::noalloc(false)]] [[clang::noalloc(true)]]; // expected-error {{noalloc(true) and noalloc(false) attributes are not compatible}}
+void na_true_false_1() [[clang::nonallocating(true)]] [[clang::nonallocating(false)]]; // expected-error {{nonallocating(true) and nonallocating(false) attributes are not compatible}}
+void na_true_false_2() [[clang::nonallocating(false)]] [[clang::nonallocating(true)]]; // expected-error {{nonallocating(true) and nonallocating(false) attributes are not compatible}}
 
-void nl_true_na_true_1() [[clang::nolock]] [[clang::noalloc]];
-void nl_true_na_true_2() [[clang::noalloc]] [[clang::nolock]];
+void nl_true_na_true_1() [[clang::nonblocking]] [[clang::nonallocating]];
+void nl_true_na_true_2() [[clang::nonallocating]] [[clang::nonblocking]];
 
-void nl_true_na_false_1() [[clang::nolock]] [[clang::noalloc(false)]]; // expected-error {{nolock(true) and noalloc(false) attributes are not compatible}}
-void nl_true_na_false_2() [[clang::noalloc(false)]] [[clang::nolock]]; // expected-error {{nolock(true) and noalloc(false) attributes are not compatible}}
+void nl_true_na_false_1() [[clang::nonblocking]] [[clang::nonallocating(false)]]; // expected-error {{nonblocking(true) and nonallocating(false) attributes are not compatible}}
+void nl_true_na_false_2() [[clang::nonallocating(false)]] [[clang::nonblocking]]; // expected-error {{nonblocking(true) and nonallocating(false) attributes are not compatible}}
 
-void nl_false_na_true_1() [[clang::nolock(false)]] [[clang::noalloc]];
-void nl_false_na_true_2() [[clang::noalloc]] [[clang::nolock(false)]];
+void nl_false_na_true_1() [[clang::nonblocking(false)]] [[clang::nonallocating]];
+void nl_false_na_true_2() [[clang::nonallocating]] [[clang::nonblocking(false)]];
 
-void nl_false_na_false_1() [[clang::nolock(false)]] [[clang::noalloc(false)]];
-void nl_false_na_false_2() [[clang::noalloc(false)]] [[clang::nolock(false)]];
+void nl_false_na_false_1() [[clang::nonblocking(false)]] [[clang::nonallocating(false)]];
+void nl_false_na_false_2() [[clang::nonallocating(false)]] [[clang::nonblocking(false)]];
 
 // --- TYPE CONVERSIONS ---
 
 void unannotated();
-void nolock() [[clang::nolock]];
-void noalloc() [[clang::noalloc]];
+void nonblocking() [[clang::nonblocking]];
+void nonallocating() [[clang::nonallocating]];
 void type_conversions()
 {
 	// It's fine to remove a performance constraint.
 	void (*fp_plain)();
 
 	fp_plain = unannotated;
-	fp_plain = nolock;
-	fp_plain = noalloc;
-
-	// Adding/spoofing nolock is unsafe.
-	void (*fp_nolock)() [[clang::nolock]];
-	fp_nolock = nolock;
-	fp_nolock = unannotated; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
-	fp_nolock = noalloc; // expected-warning {{attribute 'nolock' should not be added via type conversion}}
-
-	// Adding/spoofing noalloc is unsafe.
-	void (*fp_noalloc)() [[clang::noalloc]];
-	fp_noalloc = noalloc;
-	fp_noalloc = nolock; // no warning because nolock includes noalloc fp_noalloc = unannotated;
-	fp_noalloc = unannotated; // expected-warning {{attribute 'noalloc' should not be added via type conversion}}
+	fp_plain = nonblocking;
+	fp_plain = nonallocating;
+
+	// Adding/spoofing nonblocking is unsafe.
+	void (*fp_nonblocking)() [[clang::nonblocking]];
+	fp_nonblocking = nonblocking;
+	fp_nonblocking = unannotated; // expected-warning {{attribute 'nonblocking' should not be added via type conversion}}
+	fp_nonblocking = nonallocating; // expected-warning {{attribute 'nonblocking' should not be added via type conversion}}
+
+	// Adding/spoofing nonallocating is unsafe.
+	void (*fp_nonallocating)() [[clang::nonallocating]];
+	fp_nonallocating = nonallocating;
+	fp_nonallocating = nonblocking; // no warning because nonblocking includes nonallocating fp_nonallocating = unannotated;
+	fp_nonallocating = unannotated; // expected-warning {{attribute 'nonallocating' should not be added via type conversion}}
 }
 
 #ifdef __cplusplus
-// There was a bug: noexcept and nolock could be individually removed in conversion, but not both	
+// There was a bug: noexcept and nonblocking could be individually removed in conversion, but not both	
 void type_conversions_2()
 {
 	auto receives_fp = [](void (*fp)()) {
 	};
 	
 	auto ne = +[]() noexcept {};
-	auto nl = +[]() [[clang::nolock]] {};
-	auto nl_ne = +[]() noexcept [[clang::nolock]] {};
+	auto nl = +[]() [[clang::nonblocking]] {};
+	auto nl_ne = +[]() noexcept [[clang::nonblocking]] {};
 	
 	receives_fp(ne);
 	receives_fp(nl);
@@ -82,14 +82,14 @@ void type_conversions_2()
 #ifdef __cplusplus
 struct Base {
 	virtual void f1();
-	virtual void nolock() noexcept [[clang::nolock]];
-	virtual void noalloc() noexcept [[clang::noalloc]];
+	virtual void nonblocking() noexcept [[clang::nonblocking]];
+	virtual void nonallocating() noexcept [[clang::nonallocating]];
 };
 
 struct Derived : public Base {
-	void f1() [[clang::nolock]] override;
-	void nolock() noexcept override;
-	void noalloc() noexcept override;
+	void f1() [[clang::nonblocking]] override;
+	void nonblocking() noexcept override;
+	void nonallocating() noexcept override;
 };
 #endif // __cplusplus
 
@@ -98,12 +98,12 @@ struct Derived : public Base {
 #ifdef __cplusplus
 // In C++, the third declaration gets seen as a redeclaration of the second.
 void f2();
-void f2() [[clang::nolock]]; // expected-note {{previous declaration is here}}
-void f2(); // expected-warning {{attribute 'nolock' on function does not match previous declaration}}
+void f2() [[clang::nonblocking]]; // expected-note {{previous declaration is here}}
+void f2(); // expected-warning {{attribute 'nonblocking' on function does not match previous declaration}}
 #else
 // In C, the third declaration is redeclaration of the first (?).
 void f2();
-void f2() [[clang::nolock]];
+void f2() [[clang::nonblocking]];
 void f2();
 #endif
 // Note: we verify that the attribute is actually seen during the constraints tests.
diff --git a/clang/test/Sema/attr-nolock-syntax.cpp b/clang/test/Sema/attr-nolock-syntax.cpp
index 8deb3e88cc7d25..4e486c5a973ab9 100644
--- a/clang/test/Sema/attr-nolock-syntax.cpp
+++ b/clang/test/Sema/attr-nolock-syntax.cpp
@@ -10,86 +10,86 @@
 namespace square_brackets {
 
 // On the type of the FunctionDecl
-void nl_function() [[clang::nolock]];
-// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nolock))'
+void nl_function() [[clang::nonblocking]];
+// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nonblocking))'
 
 // On the type of the VarDecl holding a function pointer
-void (*nl_func_a)() [[clang::nolock]];
-// CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nolock))'
+void (*nl_func_a)() [[clang::nonblocking]];
+// CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nonblocking))'
 
 // Check alternate attribute type and placement
-__attribute__((clang_nolock)) void (*nl_func_b)();
-// CHECK: VarDecl {{.*}} nl_func_b 'void (*)() __attribute__((clang_nolock))'
+__attribute__((clang_nonblocking)) void (*nl_func_b)();
+// CHECK: VarDecl {{.*}} nl_func_b 'void (*)() __attribute__((clang_nonblocking))'
 
 // On the type of the ParmVarDecl of a function parameter
-static void nlReceiver(void (*nl_func)() [[clang::nolock]]);
-// CHECK: ParmVarDecl {{.*}} nl_func 'void (*)() __attribute__((clang_nolock))'
+static void nlReceiver(void (*nl_func)() [[clang::nonblocking]]);
+// CHECK: ParmVarDecl {{.*}} nl_func 'void (*)() __attribute__((clang_nonblocking))'
 
 // As an AttributedType within the nested types of a typedef
-typedef void (*nl_fp_type)() [[clang::nolock]];
-// CHECK: TypedefDecl {{.*}} nl_fp_type 'void (*)() __attribute__((clang_nolock))'
-using nl_fp_talias = void (*)() [[clang::nolock]];
-// CHECK: TypeAliasDecl {{.*}} nl_fp_talias 'void (*)() __attribute__((clang_nolock))'
+typedef void (*nl_fp_type)() [[clang::nonblocking]];
+// CHECK: TypedefDecl {{.*}} nl_fp_type 'void (*)() __attribute__((clang_nonblocking))'
+using nl_fp_talias = void (*)() [[clang::nonblocking]];
+// CHECK: TypeAliasDecl {{.*}} nl_fp_talias 'void (*)() __attribute__((clang_nonblocking))'
 
 // From a typedef or typealias, on a VarDecl
 nl_fp_type nl_fp_var1;
-// CHECK: VarDecl {{.*}} nl_fp_var1 'nl_fp_type':'void (*)() __attribute__((clang_nolock))'
+// CHECK: VarDecl {{.*}} nl_fp_var1 'nl_fp_type':'void (*)() __attribute__((clang_nonblocking))'
 nl_fp_talias nl_fp_var2;
-// CHECK: VarDecl {{.*}} nl_fp_var2 'nl_fp_talias':'void (*)() __attribute__((clang_nolock))'
+// CHECK: VarDecl {{.*}} nl_fp_var2 'nl_fp_talias':'void (*)() __attribute__((clang_nonblocking))'
 
 // On type of a FieldDecl
 struct Struct {
-	void (*nl_func_field)() [[clang::nolock]];
-// CHECK: FieldDecl {{.*}} nl_func_field 'void (*)() __attribute__((clang_nolock))'
+	void (*nl_func_field)() [[clang::nonblocking]];
+// CHECK: FieldDecl {{.*}} nl_func_field 'void (*)() __attribute__((clang_nonblocking))'
 };
 
-// noalloc should be subsumed into nolock
-void nl1() [[clang::nolock]] [[clang::noalloc]];
-// CHECK: FunctionDecl {{.*}} nl1 'void () __attribute__((clang_nolock))'
+// nonallocating should be subsumed into nonblocking
+void nl1() [[clang::nonblocking]] [[clang::nonallocating]];
+// CHECK: FunctionDecl {{.*}} nl1 'void () __attribute__((clang_nonblocking))'
 
-void nl2() [[clang::noalloc]] [[clang::nolock]];
-// CHECK: FunctionDecl {{.*}} nl2 'void () __attribute__((clang_nolock))'
+void nl2() [[clang::nonallocating]] [[clang::nonblocking]];
+// CHECK: FunctionDecl {{.*}} nl2 'void () __attribute__((clang_nonblocking))'
 
 decltype(nl1) nl3;
-// CHECK: FunctionDecl {{.*}} nl3 'decltype(nl1)':'void () __attribute__((clang_nolock))'
+// CHECK: FunctionDecl {{.*}} nl3 'decltype(nl1)':'void () __attribute__((clang_nonblocking))'
 
 // Attribute propagates from base class virtual method to overrides.
 struct Base {
-	virtual void nl_method() [[clang::nolock]];
+	virtual void nl_method() [[clang::nonblocking]];
 };
 struct Derived : public Base {
 	void nl_method() override;
-	// CHECK: CXXMethodDecl {{.*}} nl_method 'void () __attribute__((clang_nolock))'
+	// CHECK: CXXMethodDecl {{.*}} nl_method 'void () __attribute__((clang_nonblocking))'
 };
 
 // --- Blocks ---
 
 // On the type of the VarDecl holding a BlockDecl
-void (^nl_block1)() [[clang::nolock]] = ^() [[clang::nolock]] {};
-// CHECK: VarDecl {{.*}} nl_block1 'void (^)() __attribute__((clang_nolock))'
+void (^nl_block1)() [[clang::nonblocking]] = ^() [[clang::nonblocking]] {};
+// CHECK: VarDecl {{.*}} nl_block1 'void (^)() __attribute__((clang_nonblocking))'
 
-int (^nl_block2)() [[clang::nolock]] = ^() [[clang::nolock]] { return 0; };
-// CHECK: VarDecl {{.*}} nl_block2 'int (^)() __attribute__((clang_nolock))'
+int (^nl_block2)() [[clang::nonblocking]] = ^() [[clang::nonblocking]] { return 0; };
+// CHECK: VarDecl {{.*}} nl_block2 'int (^)() __attribute__((clang_nonblocking))'
 
 // The operand of the CallExpr is an ImplicitCastExpr of a DeclRefExpr -> nl_block which hold the attribute
 static void blockCaller() { nl_block1(); }
-// CHECK: DeclRefExpr {{.*}} 'nl_block1' 'void (^)() __attribute__((clang_nolock))'
+// CHECK: DeclRefExpr {{.*}} 'nl_block1' 'void (^)() __attribute__((clang_nonblocking))'
 
 // --- Lambdas ---
 
 // On the operator() of a lambda's CXXMethodDecl
-auto nl_lambda = []() [[clang::nolock]] {};
-// CHECK: CXXMethodDecl {{.*}} operator() 'void () const __attribute__((clang_nolock))' inline
+auto nl_lambda = []() [[clang::nonblocking]] {};
+// CHECK: CXXMethodDecl {{.*}} operator() 'void () const __attribute__((clang_nonblocking))' inline
 
 // =========================================================================================
 // Square brackets, false
 
-void nl_func_false() [[clang::nolock(false)]];
-// CHECK: FunctionDecl {{.*}} nl_func_false 'void () __attribute__((clang_nolock(false)))'
+void nl_func_false() [[clang::nonblocking(false)]];
+// CHECK: FunctionDecl {{.*}} nl_func_false 'void () __attribute__((clang_nonblocking(false)))'
 
 // TODO: This exposes a bug where a type attribute is lost when inferring a lambda's
 // return type.
-auto nl_lambda_false = []() [[clang::nolock(false)]] {};
+auto nl_lambda_false = []() [[clang::nonblocking(false)]] {};
 
 } // namespace square_brackets
 
@@ -101,19 +101,19 @@ auto nl_lambda_false = []() [[clang::nolock(false)]] {};
 namespace gnu_style {
 
 // On the type of the FunctionDecl
-void nl_function() __attribute__((clang_nolock));
-// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nolock))'
+void nl_function() __attribute__((clang_nonblocking));
+// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nonblocking))'
 
 // Alternate placement on the FunctionDecl
-__attribute__((clang_nolock)) void nl_function();
-// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nolock))'
+__attribute__((clang_nonblocking)) void nl_function();
+// CHECK: FunctionDecl {{.*}} nl_function 'void () __attribute__((clang_nonblocking))'
 
 // On the type of the VarDecl holding a function pointer
-void (*nl_func_a)() __attribute__((clang_nolock));
-// CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nolock))'
+void (*nl_func_a)() __attribute__((clang_nonblocking));
+// CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nonblocking))'
 
 
 
 } // namespace gnu_style
 
-// TODO: Duplicate the above for noalloc
+// TODO: Duplicate the above for nonallocating
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
index 914c4d09764ee8..f33a9fe2540533 100644
--- a/clang/test/Sema/attr-nolock-wip.cpp
+++ b/clang/test/Sema/attr-nolock-wip.cpp
@@ -1,7 +1,7 @@
 // RUN: %clang_cc1 -fsyntax-only -fblocks -verify %s
 
-#if !__has_attribute(clang_nolock)
-#error "the 'nolock' attribute is not available"
+#if !__has_attribute(clang_nonblocking)
+#error "the 'nonblocking' attribute is not available"
 #endif
 
 
@@ -13,31 +13,31 @@ struct HasVirtual {
 	virtual void method();
 };
 
-void nl999(HasVirtual& x) [[clang::nolock]] {
+void nl999(HasVirtual& x) [[clang::nonblocking]] {
 	x.method();
 }
 
 
 
 #if 0
-	using nl_sugar = int (*)(int) [[clang::nolock]];
+	using nl_sugar = int (*)(int) [[clang::nonblocking]];
 
 	void receives_fp_nl(nl_sugar fp) {
 	}
 	
-	int callback(int) noexcept [[clang::nolock]];
+	int callback(int) noexcept [[clang::nonblocking]];
 
 void type_conversions_2()
 {
 	auto receives_fp = [](void (*fp)()) {
 	};
 	
-	//auto receives_fp_nl = [](void (*fp)() [[clang::nolock]]) {
+	//auto receives_fp_nl = [](void (*fp)() [[clang::nonblocking]]) {
 	//};
 
 	auto ne = +[]() noexcept {};
-	auto nl = +[]() [[clang::nolock]] {};
-	//auto nl_ne = +[](int x) noexcept [[clang::nolock]] -> int  { return x; };
+	auto nl = +[]() [[clang::nonblocking]] {};
+	//auto nl_ne = +[](int x) noexcept [[clang::nonblocking]] -> int  { return x; };
 	
 	receives_fp(ne);
 	receives_fp(nl);
@@ -51,11 +51,11 @@ void type_conversions_2()
 struct S {
 	void foo();
 	// void foo() noexcept; // error, redeclaration
-	// void foo() [[clang::nolock]]; // error, redeclaration
+	// void foo() [[clang::nonblocking]]; // error, redeclaration
 	
 	using FP = void (*)();
 	using FPNE = void (*)() noexcept;
-	using FPNL = void (*)() [[clang::nolock]];
+	using FPNL = void (*)() [[clang::nonblocking]];
 	
 	void bar(FP x);
 	void bar(FPNE x);	// This is a distinct overload
@@ -101,9 +101,9 @@ typedef integral_constant<bool, true>  true_type;
 typedef integral_constant<bool, false> false_type;
 
 template <typename T>
-struct is_nolock;
+struct is_nonblocking;
 
-void g() [[clang::nolock]];
-void h() [[clang::nolock(false)]];
+void g() [[clang::nonblocking]];
+void h() [[clang::nonblocking(false)]];
 #endif
 

>From c02635584ee7c1df0adf9409fdbfd2aaf2c9cc15 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 3 Apr 2024 07:50:17 -0700
Subject: [PATCH 20/40] Remove vestigial FunctionEffect flags

---
 clang/include/clang/AST/Type.h           | 29 ++++--------
 clang/lib/AST/Type.cpp                   | 11 ++---
 clang/lib/Sema/AnalysisBasedWarnings.cpp | 58 ++++++++++--------------
 clang/lib/Sema/SemaDecl.cpp              | 11 +----
 clang/lib/Sema/SemaOverload.cpp          |  1 -
 5 files changed, 40 insertions(+), 70 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index cdfeb8eb715399..79cfb407fac5cf 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4458,25 +4458,16 @@ class FunctionEffect {
   // would OR together the bits of multiple effects.)
   using Flags = unsigned;
   enum FlagBit : unsigned {
-    // Some effects require verification, e.g. nonblocking(true); others might
-    // not? (no example yet; TODO: maybe always true, vestigial from
-    // nonblocking(false)).
-    FE_RequiresVerification = 0x1,
-
-    // Does this effect want to verify all function calls originating in
-    // functions having this effect? TODO: maybe always true, vestigial.
-    FE_VerifyCalls = 0x2,
-
     // Can verification inspect callees' implementations? (e.g. nonblocking:
     // yes, tcb+types: no)
-    FE_InferrableOnCallees = 0x4,
+    FE_InferrableOnCallees = 0x1,
 
     // Language constructs which effects can diagnose as disallowed.
-    FE_ExcludeThrow = 0x8,
-    FE_ExcludeCatch = 0x10,
-    FE_ExcludeObjCMessageSend = 0x20,
-    FE_ExcludeStaticLocalVars = 0x40,
-    FE_ExcludeThreadLocalVars = 0x80
+    FE_ExcludeThrow = 0x2,
+    FE_ExcludeCatch = 0x4,
+    FE_ExcludeObjCMessageSend = 0x8,
+    FE_ExcludeStaticLocalVars = 0x10,
+    FE_ExcludeThreadLocalVars = 0x20
   };
 
   /// Describes the result of effects differing between a base class's virtual
@@ -4553,10 +4544,10 @@ class FunctionEffect {
   /// function.
   bool canInferOnFunction(QualType QT, const TypeSourceInfo *FType) const;
 
-  // Called if FE_VerifyCalls flag is set; return false for success. When true
-  // is returned for a direct call, then the FE_InferrableOnCallees flag may
-  // trigger inference rather than an immediate diagnostic. Caller should be
-  // assumed to have the effect (it may not have it explicitly when inferring).
+  // Return false for success. When true is returned for a direct call, then the
+  // FE_InferrableOnCallees flag may trigger inference rather than an immediate
+  // diagnostic. Caller should be assumed to have the effect (it may not have it
+  // explicitly when inferring).
   bool diagnoseFunctionCall(bool Direct, FunctionEffectSet CalleeFX) const;
 
   friend bool operator==(const FunctionEffect &LHS, const FunctionEffect &RHS) {
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 4455a06421a623..939562ab2d1762 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5030,16 +5030,15 @@ FunctionEffect::FunctionEffect(Type T)
     : Type_(unsigned(T)), Flags_(0), Padding(0) {
   switch (T) {
   case Type::NonBlocking:
-    Flags_ = FE_RequiresVerification | FE_VerifyCalls | FE_InferrableOnCallees |
-             FE_ExcludeThrow | FE_ExcludeCatch | FE_ExcludeObjCMessageSend |
-             FE_ExcludeStaticLocalVars | FE_ExcludeThreadLocalVars;
+    Flags_ = FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
+             FE_ExcludeObjCMessageSend | FE_ExcludeStaticLocalVars |
+             FE_ExcludeThreadLocalVars;
     break;
 
   case Type::NonAllocating:
     // Same as NonBlocking, except without FE_ExcludeStaticLocalVars
-    Flags_ = FE_RequiresVerification | FE_VerifyCalls | FE_InferrableOnCallees |
-             FE_ExcludeThrow | FE_ExcludeCatch | FE_ExcludeObjCMessageSend |
-             FE_ExcludeThreadLocalVars;
+    Flags_ = FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
+             FE_ExcludeObjCMessageSend | FE_ExcludeThreadLocalVars;
     break;
   default:
     break;
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 9b222595a7302c..f76571afcfa2f4 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2620,16 +2620,10 @@ class PendingFunctionAnalysis {
   PendingFunctionAnalysis(Sema &Sem, const CallableInfo &CInfo,
                           FunctionEffectSet AllInferrableEffectsToVerify) {
     ASTContext &Ctx = Sem.getASTContext();
-    MutableFunctionEffectSet FX;
-    for (const auto &Effect : CInfo.Effects) {
-      if (Effect.flags() & FunctionEffect::FE_RequiresVerification) {
-        FX.insert(Effect);
-      }
-    }
-    DeclaredVerifiableEffects = Ctx.getUniquedFunctionEffectSet(FX);
+    DeclaredVerifiableEffects = CInfo.Effects;
 
     // Check for effects we are not allowed to infer
-    FX.clear();
+    MutableFunctionEffectSet FX;
     TypeSourceInfo *TSI = nullptr;
     if (const auto *DD = dyn_cast<DeclaratorDecl>(CInfo.CDecl)) {
       TSI = DD->getTypeSourceInfo();
@@ -3050,26 +3044,24 @@ class Analyzer {
 
     auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
       const auto Flags = Effect.flags();
-      if (Flags & FunctionEffect::FE_VerifyCalls) {
-        const bool diagnose =
-            Effect.diagnoseFunctionCall(DirectCall, CalleeEffects);
-        if (diagnose) {
-          // If inference is not allowed, or the target is indirect (virtual
-          // method/function ptr?), generate a diagnostic now.
-          if (!IsInferencePossible ||
-              !(Flags & FunctionEffect::FE_InferrableOnCallees)) {
-            if (Callee.FuncType == SpecialFuncType::None) {
-              PFA.checkAddDiagnostic(Inferring,
-                                     {Effect, DiagnosticID::CallsUnsafeDecl,
-                                      CallLoc, Callee.CDecl});
-            } else {
-              PFA.checkAddDiagnostic(
-                  Inferring, {Effect, DiagnosticID::AllocatesMemory, CallLoc});
-            }
+      const bool diagnose =
+          Effect.diagnoseFunctionCall(DirectCall, CalleeEffects);
+      if (diagnose) {
+        // If inference is not allowed, or the target is indirect (virtual
+        // method/function ptr?), generate a diagnostic now.
+        if (!IsInferencePossible ||
+            !(Flags & FunctionEffect::FE_InferrableOnCallees)) {
+          if (Callee.FuncType == SpecialFuncType::None) {
+            PFA.checkAddDiagnostic(
+                Inferring,
+                {Effect, DiagnosticID::CallsUnsafeDecl, CallLoc, Callee.CDecl});
           } else {
-            // Inference is allowed and necessary; defer it.
-            PFA.addUnverifiedDirectCall(Callee.CDecl, CallLoc);
+            PFA.checkAddDiagnostic(
+                Inferring, {Effect, DiagnosticID::AllocatesMemory, CallLoc});
           }
+        } else {
+          // Inference is allowed and necessary; defer it.
+          PFA.addUnverifiedDirectCall(Callee.CDecl, CallLoc);
         }
       }
     };
@@ -3327,14 +3319,12 @@ class Analyzer {
           CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
 
       auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
-        if (Effect.flags() & FunctionEffect::FE_VerifyCalls) {
-          if (FPT == nullptr ||
-              Effect.diagnoseFunctionCall(
-                  /*direct=*/false, FPT->getFunctionEffects())) {
-            addDiagnosticInner(Inferring, Effect,
-                               DiagnosticID::CallsDisallowedExpr,
-                               Call->getBeginLoc());
-          }
+        if (FPT == nullptr ||
+            Effect.diagnoseFunctionCall(
+                /*direct=*/false, FPT->getFunctionEffects())) {
+          addDiagnosticInner(Inferring, Effect,
+                             DiagnosticID::CallsDisallowedExpr,
+                             Call->getBeginLoc());
         }
       };
 
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 3df4d15a028c15..d6d1cd2dd68ad2 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11153,16 +11153,7 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
 
   // Filter out declarations that the FunctionEffect analysis should skip
   // and not verify.
-  bool FXNeedVerification = false;
-  for (const auto &Effect : FX) {
-    if (Effect.flags() & FunctionEffect::FE_RequiresVerification) {
-      AllEffectsToVerify.insert(Effect);
-      FXNeedVerification = true;
-    }
-  }
-  if (!FXNeedVerification) {
-    return;
-  }
+  AllEffectsToVerify |= FX;
 
   // Record the declaration for later analysis.
   DeclsWithEffectsToVerify.push_back(D);
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index bcbcb8729c6d7f..02a4f106a648f9 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1788,7 +1788,6 @@ ExprResult Sema::PerformImplicitConversion(Expr *From, QualType ToType,
 /// type.
 bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
                                 QualType &ResultTy) {
-
   if (Context.hasSameUnqualifiedType(FromType, ToType))
     return false;
 

>From 02a3b7aa689c33220bcb266f6d7dfbb469939198 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Thu, 4 Apr 2024 09:17:11 -0700
Subject: [PATCH 21/40] ArrayRef<const FunctionEffect> ->
 ArrayRef<FunctionEffect> (it's already const)

---
 clang/include/clang/AST/ASTContext.h |  6 +++---
 clang/include/clang/AST/Type.h       | 10 ++++------
 clang/lib/AST/ASTContext.cpp         |  6 +++---
 3 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index 15cb320fb0e259..de984ace425eb0 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -467,10 +467,10 @@ class ASTContext : public RefCountedBase<ASTContext> {
   Module *CurrentCXXNamedModule = nullptr;
 
   class FunctionEffectSetUniquing {
-    llvm::DenseSet<llvm::ArrayRef<const FunctionEffect>> Set;
+    llvm::DenseSet<llvm::ArrayRef<FunctionEffect>> Set;
 
   public:
-    FunctionEffectSet getUniqued(llvm::ArrayRef<const FunctionEffect> FX);
+    FunctionEffectSet getUniqued(llvm::ArrayRef<FunctionEffect> FX);
 
     ~FunctionEffectSetUniquing();
   };
@@ -1084,7 +1084,7 @@ class ASTContext : public RefCountedBase<ASTContext> {
 
   /// Get or create a uniqued, immutable FunctionEffectSet.
   FunctionEffectSet
-  getUniquedFunctionEffectSet(llvm::ArrayRef<const FunctionEffect> FX) {
+  getUniquedFunctionEffectSet(llvm::ArrayRef<FunctionEffect> FX) {
     return UniquedFunctionEffectSet.getUniqued(FX);
   }
 
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 79cfb407fac5cf..657f3ee6fc779c 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4578,9 +4578,7 @@ class MutableFunctionEffectSet : public SmallVector<FunctionEffect, 4> {
 
   MutableFunctionEffectSet &operator|=(FunctionEffectSet RHS);
 
-  operator llvm::ArrayRef<const FunctionEffect>() const {
-    return {data(), size()};
-  }
+  operator llvm::ArrayRef<FunctionEffect>() const { return {data(), size()}; }
 };
 
 /// A constant, uniqued set of FunctionEffect instances.
@@ -4590,11 +4588,11 @@ class FunctionEffectSet {
 private:
   friend class ASTContext; // so it can call the private constructor
 
-  explicit FunctionEffectSet(llvm::ArrayRef<const FunctionEffect> Array)
+  explicit FunctionEffectSet(llvm::ArrayRef<FunctionEffect> Array)
       : Impl(Array) {}
 
   // Points to a separately allocated array, uniqued.
-  llvm::ArrayRef<const FunctionEffect> Impl;
+  llvm::ArrayRef<FunctionEffect> Impl;
 
 public:
   using Differences = SmallVector<std::pair<FunctionEffect, /*added=*/bool>>;
@@ -4618,7 +4616,7 @@ class FunctionEffectSet {
 
   iterator end() const { return Impl.end(); }
 
-  ArrayRef<const FunctionEffect> items() const { return Impl; }
+  ArrayRef<FunctionEffect> items() const { return Impl; }
 
   bool operator==(const FunctionEffectSet &RHS) const {
     return Impl.data() == RHS.Impl.data();
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 82bd24f49acd87..26523c1ab370c8 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -13808,7 +13808,7 @@ StringRef ASTContext::getCUIDHash() const {
   return CUIDHash;
 }
 
-using FunctionEffectSpan = llvm::ArrayRef<const FunctionEffect>;
+using FunctionEffectSpan = llvm::ArrayRef<FunctionEffect>;
 
 llvm::hash_code hash_value(const FunctionEffect &Effect) {
   return llvm::hash_value(Effect.opaqueRepr());
@@ -13854,7 +13854,7 @@ ASTContext::getUniquedFunctionEffectSet(llvm::ArrayRef<uint32_t> FX) {
 }
 
 FunctionEffectSet ASTContext::FunctionEffectSetUniquing::getUniqued(
-    llvm::ArrayRef<const FunctionEffect> FX) {
+    llvm::ArrayRef<FunctionEffect> FX) {
   if (FX.empty()) {
     return {};
   }
@@ -13870,7 +13870,7 @@ FunctionEffectSet ASTContext::FunctionEffectSetUniquing::getUniqued(
   std::copy(FX.begin(), FX.end(), Storage);
 
   // Make a new wrapper and insert it into the set.
-  llvm::ArrayRef<const FunctionEffect> Arr(Storage, FX.size());
+  llvm::ArrayRef<FunctionEffect> Arr(Storage, FX.size());
   auto [InsIter, _] = Set.insert(Arr);
   return FunctionEffectSet(*InsIter);
 }

>From 8121422216aec6c52582314e72bcfa0e2ca598c8 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Fri, 5 Apr 2024 08:04:28 -0700
Subject: [PATCH 22/40] Adding the `blocking` and `allocating` attributes, as
 synonyms for `nonblocking/nonallocating(false)`. Rename test files, remove
 "wip". Misc. cleanup from PR.

---
 clang/include/clang/Basic/Attr.td             |  15 +++
 clang/lib/AST/Type.cpp                        |  13 +--
 clang/lib/AST/TypePrinter.cpp                 |  12 +-
 clang/lib/Sema/Sema.cpp                       |   4 +-
 clang/lib/Sema/SemaDecl.cpp                   |   2 -
 clang/lib/Sema/SemaExprCXX.cpp                |   9 +-
 clang/lib/Sema/SemaOverload.cpp               |   2 +-
 clang/lib/Sema/SemaType.cpp                   |  77 +++++++------
 clang/test/Sema/attr-nolock-wip.cpp           | 109 ------------------
 ...nts.mm => attr-nonblocking-constraints.mm} |   0
 ...ock-sema.cpp => attr-nonblocking-sema.cpp} |  20 ++--
 ...syntax.cpp => attr-nonblocking-syntax.cpp} |  14 +--
 12 files changed, 91 insertions(+), 186 deletions(-)
 delete mode 100644 clang/test/Sema/attr-nolock-wip.cpp
 rename clang/test/Sema/{attr-nolock-constraints.mm => attr-nonblocking-constraints.mm} (100%)
 rename clang/test/Sema/{attr-nolock-sema.cpp => attr-nonblocking-sema.cpp} (72%)
 rename clang/test/Sema/{attr-nolock-syntax.cpp => attr-nonblocking-syntax.cpp} (95%)

diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 9f38a098384348..908edba2222f88 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1419,6 +1419,21 @@ def NonAllocating : TypeAttr {
   let Documentation = [NonBlockingNonAllocatingDocs];
 }
 
+def Blocking : TypeAttr {
+  let Spellings = [CXX11<"clang", "blocking">,
+                   C23<"clang", "blocking">,
+                   GNU<"clang_blocking">];
+
+  let Documentation = [NonBlockingNonAllocatingDocs];
+}
+
+def Allocating : TypeAttr {
+  let Spellings = [CXX11<"clang", "allocating">,
+                   C23<"clang", "allocating">,
+                   GNU<"clang_allocating">];
+  let Documentation = [NonBlockingNonAllocatingDocs];
+}
+
 // Similar to CUDA, OpenCL attributes do not receive a [[]] spelling because
 // the specification does not expose them with one currently.
 def OpenCLKernel : InheritableAttr {
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 939562ab2d1762..070bedceebeddf 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3733,7 +3733,6 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   // whether the following bool is the EH spec or part of the arguments.
 
   ID.AddPointer(epi.FunctionEffects.getOpaqueValue());
-
   ID.AddPointer(Result.getAsOpaquePtr());
   for (unsigned i = 0; i != NumParams; ++i)
     ID.AddPointer(ArgTys[i].getAsOpaquePtr());
@@ -5027,7 +5026,7 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
 }
 
 FunctionEffect::FunctionEffect(Type T)
-    : Type_(unsigned(T)), Flags_(0), Padding(0) {
+    : Type_(static_cast<unsigned>(T)), Flags_(0), Padding(0) {
   switch (T) {
   case Type::NonBlocking:
     Flags_ = FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
@@ -5104,8 +5103,8 @@ FunctionEffect::OverrideResult FunctionEffect::diagnoseMethodOverride(
   switch (type()) {
   case Type::NonAllocating:
   case Type::NonBlocking:
-    // nonblocking/nonallocating can't be removed from an override
-    // adding -> false, removing -> true (diagnose)
+    // if added on an override, that's fine and not diagnosed.
+    // if missing from an override (removed), propagate from base to derived.
     return Adding ? OverrideResult::Ignore : OverrideResult::Propagate;
   default:
     break;
@@ -5119,8 +5118,8 @@ bool FunctionEffect::canInferOnFunction(QualType QT,
   case Type::NonAllocating:
   case Type::NonBlocking: {
     // Does the sugar have nonblocking(false) / nonallocating(false) ?
-    if (QT->hasAttr(type() == Type::NonBlocking ? attr::Kind::NonBlocking
-                                                : attr::Kind::NonAllocating)) {
+    if (QT->hasAttr(type() == Type::NonBlocking ? attr::Kind::Blocking
+                                                : attr::Kind::Allocating)) {
       return false;
     }
 
@@ -5264,7 +5263,7 @@ bool FunctionEffectSet::operator<(const FunctionEffectSet &RHS) const {
                                       RHS.end());
 }
 
-void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
+LLVM_DUMP_METHOD void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
   OS << "Effects{";
   bool First = true;
   for (const auto &Effect : *this) {
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 16290808ee5080..c086f9829dc409 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -1992,16 +1992,16 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   case attr::ArmMveStrictPolymorphism:
     OS << "__clang_arm_mve_strict_polymorphism";
     break;
+  case attr::Blocking:
+    OS << "clang_blocking";
+    break;
+  case attr::Allocating:
+    OS << "clang_allocating";
+    break;
 
   // Nothing to print for this attribute.
   case attr::HLSLParamModifier:
     break;
-  case attr::NonBlocking:
-    OS << "clang_nonblocking(false)";
-    break;
-  case attr::NonAllocating:
-    OS << "clang_nonallocating(false)";
-    break;
   }
   OS << "))";
 }
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index d0eb9194bc65b5..2cb1b931cf6fa4 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -682,8 +682,8 @@ ExprResult Sema::ImpCastExprToType(Expr *E, QualType Ty,
 
   diagnoseNullableToNonnullConversion(Ty, E->getType(), E->getBeginLoc());
   diagnoseZeroToNullptrConversion(Kind, E);
-  if (!isCast(CCK) && !E->isNullPointerConstant(
-                          Context, Expr::NPC_NeverValueDependent /* ???*/)) {
+  if (!isCast(CCK) &&
+      !E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) {
     diagnoseFunctionEffectConversion(Ty, E->getType(), E->getBeginLoc());
   }
 
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index d6d1cd2dd68ad2..f68e207805b4d1 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11151,8 +11151,6 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
     return;
   }
 
-  // Filter out declarations that the FunctionEffect analysis should skip
-  // and not verify.
   AllEffectsToVerify |= FX;
 
   // Record the declaration for later analysis.
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index e0371b9cf64df2..76bb78aa8b5458 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -4953,17 +4953,10 @@ Sema::PerformImplicitConversion(Expr *From, QualType ToType,
 
   // If this conversion sequence succeeded and involved implicitly converting a
   // _Nullable type to a _Nonnull one, complain.
-  if (!isCast(CCK)) {
+  if (!isCast(CCK))
     diagnoseNullableToNonnullConversion(ToType, InitialFromType,
                                         From->getBeginLoc());
 
-    // TODO: This generates a redundant diagnostic for:
-    // void (^nl_block0)() NOLOCK = ^(){};
-    // if (!From->isNullPointerConstant(Context, Expr::NPC_NeverValueDependent
-    // /* ???*/))
-    //   diagnoseFunctionEffectConversion(ToType, InitialFromType,
-    //                                         From->getBeginLoc());
-  }
   return From;
 }
 
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 02a4f106a648f9..1396534949caf7 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1870,10 +1870,10 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
     }
 
     if (getLangOpts().CPlusPlus) {
-      // TODO:
       // For C, when called from checkPointerTypesForAssignment,
       // we need not to change the type, or else even an innocuous cast
       // like dropping effects will fail.
+      // TODO: Is this correct?
       FromFPT =
           dyn_cast<FunctionProtoType>(FromFn); // in case FromFn changed above
 
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 535663f77a4a28..80123ba9a59a1b 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -147,6 +147,8 @@ static void diagnoseBadTypeAttribute(Sema &S, const ParsedAttr &attr,
   case ParsedAttr::AT_NoReturn:                                                \
   case ParsedAttr::AT_NonBlocking:                                             \
   case ParsedAttr::AT_NonAllocating:                                           \
+  case ParsedAttr::AT_Blocking:                                                \
+  case ParsedAttr::AT_Allocating:                                              \
   case ParsedAttr::AT_Regparm:                                                 \
   case ParsedAttr::AT_CmseNSCall:                                              \
   case ParsedAttr::AT_ArmStreaming:                                            \
@@ -218,15 +220,15 @@ namespace {
     // nonallocating(cond). Manual logic for finding previous attributes would
     // be more complex, unless we transformed nonblocking/nonallocating(false)
     // into distinct separate attributes from the ones which are parsed.
-    BoolAttrState parsedNolock : 2;
-    BoolAttrState parsedNoalloc : 2;
+    BoolAttrState parsedNonBlocking : 2;
+    BoolAttrState parsedNonAllocating : 2;
 
   public:
     TypeProcessingState(Sema &sema, Declarator &declarator)
         : sema(sema), declarator(declarator),
           chunkIndex(declarator.getNumTypeObjects()), parsedNoDeref(false),
-          parsedNolock(BoolAttrState::Unseen),
-          parsedNoalloc(BoolAttrState::Unseen) {}
+          parsedNonBlocking(BoolAttrState::Unseen),
+          parsedNonAllocating(BoolAttrState::Unseen) {}
 
     Sema &getSema() const {
       return sema;
@@ -353,10 +355,10 @@ namespace {
 
     bool didParseNoDeref() const { return parsedNoDeref; }
 
-    void setParsedNolock(BoolAttrState v) { parsedNolock = v; }
-    BoolAttrState getParsedNolock() const { return parsedNolock; }
-    void setParsedNoalloc(BoolAttrState v) { parsedNoalloc = v; }
-    BoolAttrState getParsedNoalloc() const { return parsedNoalloc; }
+    void setParsedNonBlocking(BoolAttrState v) { parsedNonBlocking = v; }
+    BoolAttrState getParsedNonBlocking() const { return parsedNonBlocking; }
+    void setParsedNonAllocating(BoolAttrState v) { parsedNonAllocating = v; }
+    BoolAttrState getParsedNonAllocating() const { return parsedNonAllocating; }
 
     ~TypeProcessingState() {
       if (savedAttrs.empty())
@@ -7985,7 +7987,8 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
   if (!unwrapped.isFunctionType())
     return false;
 
-  const bool isNonBlocking = PAttr.getKind() == ParsedAttr::AT_NonBlocking;
+  const bool isNonBlocking = PAttr.getKind() == ParsedAttr::AT_NonBlocking ||
+                             PAttr.getKind() == ParsedAttr::AT_Blocking;
   Sema &S = state.getSema();
 
   // Require FunctionProtoType
@@ -7995,15 +7998,21 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
     return false;
   }
 
-  // Parse the conditional expression, if any
-  // TODO: There's a better way to do this. See PR feedback.
-  // TODO: Handle a type-dependent expression.
   bool Cond = true; // default
-  if (PAttr.getNumArgs() > 0) {
-    if (!S.checkBoolExprArgumentAttr(PAttr, 0, Cond)) {
-      PAttr.setInvalid();
-      return false;
+
+  if (PAttr.getKind() == ParsedAttr::AT_NonBlocking ||
+      PAttr.getKind() == ParsedAttr::AT_NonAllocating) {
+    // Parse the conditional expression, if any
+    // TODO: There's a better way to do this. See PR feedback.
+    // TODO: Handle a type-dependent expression.
+    if (PAttr.getNumArgs() > 0) {
+      if (!S.checkBoolExprArgumentAttr(PAttr, 0, Cond)) {
+        PAttr.setInvalid();
+        return false;
+      }
     }
+  } else {
+    Cond = false;
   }
 
   FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
@@ -8018,44 +8027,44 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
     return true;
   };
 
-  // check nonblocking(true) against nonblocking(false), and same for
+  // check nonblocking(true) against blocking, and same for
   // nonallocating
   const BoolAttrState newState =
       Cond ? BoolAttrState::True : BoolAttrState::False;
   const BoolAttrState oppositeNewState =
       Cond ? BoolAttrState::False : BoolAttrState::True;
   if (isNonBlocking) {
-    if (state.getParsedNolock() == oppositeNewState) {
-      return incompatible("nonblocking(true)", "nonblocking(false)");
+    if (state.getParsedNonBlocking() == oppositeNewState) {
+      return incompatible("nonblocking(true)", "blocking");
     }
-    // also check nonblocking(true) against nonallocating(false)
-    if (Cond && state.getParsedNoalloc() == BoolAttrState::False) {
-      return incompatible("nonblocking(true)", "nonallocating(false)");
+    // also check nonblocking(true) against allocating
+    if (Cond && state.getParsedNonAllocating() == BoolAttrState::False) {
+      return incompatible("nonblocking(true)", "allocating");
     }
-    state.setParsedNolock(newState);
+    state.setParsedNonBlocking(newState);
   } else {
-    if (state.getParsedNoalloc() == oppositeNewState) {
-      return incompatible("nonallocating(true)", "nonallocating(false)");
+    if (state.getParsedNonAllocating() == oppositeNewState) {
+      return incompatible("nonallocating(true)", "allocating");
     }
-    // also check nonblocking(true) against nonallocating(false)
-    if (state.getParsedNolock() == BoolAttrState::True) {
+    // also check nonblocking(true) against allocating
+    if (state.getParsedNonBlocking() == BoolAttrState::True) {
       if (!Cond) {
-        return incompatible("nonblocking(true)", "nonallocating(false)");
+        return incompatible("nonblocking(true)", "allocating");
       }
       // Ignore nonallocating(true) since we already have nonblocking(true).
       return true;
     }
-    state.setParsedNoalloc(newState);
+    state.setParsedNonAllocating(newState);
   }
 
   if (!Cond) {
-    // nonblocking(false) and nonallocating(false) are represented as sugar,
+    // blocking and allocating are represented as sugar,
     // with AttributedType
     Attr *A = nullptr;
     if (isNonBlocking) {
-      A = NonBlockingAttr::Create(S.Context, false);
+      A = BlockingAttr::Create(S.Context);
     } else {
-      A = NonAllocatingAttr::Create(S.Context, false);
+      A = AllocatingAttr::Create(S.Context);
     }
     type = state.getAttributedType(A, type, type);
     return true;
@@ -8400,7 +8409,9 @@ static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
   }
 
   if (attr.getKind() == ParsedAttr::AT_NonBlocking ||
-      attr.getKind() == ParsedAttr::AT_NonAllocating) {
+      attr.getKind() == ParsedAttr::AT_NonAllocating ||
+      attr.getKind() == ParsedAttr::AT_Blocking ||
+      attr.getKind() == ParsedAttr::AT_Allocating) {
     return handleNonBlockingNonAllocatingTypeAttr(state, attr, type, unwrapped);
   }
 
diff --git a/clang/test/Sema/attr-nolock-wip.cpp b/clang/test/Sema/attr-nolock-wip.cpp
deleted file mode 100644
index f33a9fe2540533..00000000000000
--- a/clang/test/Sema/attr-nolock-wip.cpp
+++ /dev/null
@@ -1,109 +0,0 @@
-// RUN: %clang_cc1 -fsyntax-only -fblocks -verify %s
-
-#if !__has_attribute(clang_nonblocking)
-#error "the 'nonblocking' attribute is not available"
-#endif
-
-
-// The diagnostic for inference not following a non-inline method should override
-// the one for a virtual method.
-
-struct HasVirtual {
-	virtual ~HasVirtual() = default;
-	virtual void method();
-};
-
-void nl999(HasVirtual& x) [[clang::nonblocking]] {
-	x.method();
-}
-
-
-
-#if 0
-	using nl_sugar = int (*)(int) [[clang::nonblocking]];
-
-	void receives_fp_nl(nl_sugar fp) {
-	}
-	
-	int callback(int) noexcept [[clang::nonblocking]];
-
-void type_conversions_2()
-{
-	auto receives_fp = [](void (*fp)()) {
-	};
-	
-	//auto receives_fp_nl = [](void (*fp)() [[clang::nonblocking]]) {
-	//};
-
-	auto ne = +[]() noexcept {};
-	auto nl = +[]() [[clang::nonblocking]] {};
-	//auto nl_ne = +[](int x) noexcept [[clang::nonblocking]] -> int  { return x; };
-	
-	receives_fp(ne);
-	receives_fp(nl);
-// 	receives_fp(nl_ne);
-	
-	receives_fp_nl(callback);
-}
-#endif
-
-#if 0
-struct S {
-	void foo();
-	// void foo() noexcept; // error, redeclaration
-	// void foo() [[clang::nonblocking]]; // error, redeclaration
-	
-	using FP = void (*)();
-	using FPNE = void (*)() noexcept;
-	using FPNL = void (*)() [[clang::nonblocking]];
-	
-	void bar(FP x);
-	void bar(FPNE x);	// This is a distinct overload
-	void bar(FPNL x);	// This is a distinct overload
-};
-#endif
-
-// ============================================================================
-
-#if 0
-#define RT_UNSAFE_BEGIN(reason)                                   \
-	_Pragma("clang diagnostic push")                                 \
-	_Pragma("clang diagnostic ignored \"-Wunknown-warning-option\"") \
-	_Pragma("clang diagnostic ignored \"-Wfunction-effects\"")
-
-#define RT_UNSAFE_END \
-	_Pragma("clang diagnostic pop")
-
-#define RT_UNSAFE(...)  \
-	RT_UNSAFE_BEGIN("") \
-	__VA_ARGS__            \
-	RT_UNSAFE_END
-#endif
-
-// ============================================================================
-
-#if 0
-// some messing around with type traits
-template <class _Tp, _Tp __v>
-struct integral_constant
-{
-  static constexpr const _Tp      value = __v;
-  typedef _Tp               value_type;
-  typedef integral_constant type;
-  constexpr operator value_type() const noexcept {return value;}
-  constexpr value_type operator ()() const noexcept {return value;}
-};
-
-template <class _Tp, _Tp __v>
-const _Tp integral_constant<_Tp, __v>::value;
-
-typedef integral_constant<bool, true>  true_type;
-typedef integral_constant<bool, false> false_type;
-
-template <typename T>
-struct is_nonblocking;
-
-void g() [[clang::nonblocking]];
-void h() [[clang::nonblocking(false)]];
-#endif
-
diff --git a/clang/test/Sema/attr-nolock-constraints.mm b/clang/test/Sema/attr-nonblocking-constraints.mm
similarity index 100%
rename from clang/test/Sema/attr-nolock-constraints.mm
rename to clang/test/Sema/attr-nonblocking-constraints.mm
diff --git a/clang/test/Sema/attr-nolock-sema.cpp b/clang/test/Sema/attr-nonblocking-sema.cpp
similarity index 72%
rename from clang/test/Sema/attr-nolock-sema.cpp
rename to clang/test/Sema/attr-nonblocking-sema.cpp
index 1d7881b30411af..a8e725b3a4b613 100644
--- a/clang/test/Sema/attr-nolock-sema.cpp
+++ b/clang/test/Sema/attr-nonblocking-sema.cpp
@@ -14,23 +14,23 @@ struct [[clang::nonblocking]] nl_struct2 {}; // expected-error {{'nonblocking' a
 // --- ATTRIBUTE SYNTAX: COMBINATIONS ---
 // Check invalid combinations of nonblocking/nonallocating attributes
 
-void nl_true_false_1() [[clang::nonblocking(true)]] [[clang::nonblocking(false)]]; // expected-error {{nonblocking(true) and nonblocking(false) attributes are not compatible}}
-void nl_true_false_2() [[clang::nonblocking(false)]] [[clang::nonblocking(true)]]; // expected-error {{nonblocking(true) and nonblocking(false) attributes are not compatible}}
+void nl_true_false_1() [[clang::nonblocking(true)]] [[clang::blocking]]; // expected-error {{nonblocking(true) and blocking attributes are not compatible}}
+void nl_true_false_2() [[clang::blocking]] [[clang::nonblocking(true)]]; // expected-error {{nonblocking(true) and blocking attributes are not compatible}}
 
-void na_true_false_1() [[clang::nonallocating(true)]] [[clang::nonallocating(false)]]; // expected-error {{nonallocating(true) and nonallocating(false) attributes are not compatible}}
-void na_true_false_2() [[clang::nonallocating(false)]] [[clang::nonallocating(true)]]; // expected-error {{nonallocating(true) and nonallocating(false) attributes are not compatible}}
+void na_true_false_1() [[clang::nonallocating(true)]] [[clang::allocating]]; // expected-error {{nonallocating(true) and allocating attributes are not compatible}}
+void na_true_false_2() [[clang::allocating]] [[clang::nonallocating(true)]]; // expected-error {{nonallocating(true) and allocating attributes are not compatible}}
 
 void nl_true_na_true_1() [[clang::nonblocking]] [[clang::nonallocating]];
 void nl_true_na_true_2() [[clang::nonallocating]] [[clang::nonblocking]];
 
-void nl_true_na_false_1() [[clang::nonblocking]] [[clang::nonallocating(false)]]; // expected-error {{nonblocking(true) and nonallocating(false) attributes are not compatible}}
-void nl_true_na_false_2() [[clang::nonallocating(false)]] [[clang::nonblocking]]; // expected-error {{nonblocking(true) and nonallocating(false) attributes are not compatible}}
+void nl_true_na_false_1() [[clang::nonblocking]] [[clang::allocating]]; // expected-error {{nonblocking(true) and allocating attributes are not compatible}}
+void nl_true_na_false_2() [[clang::allocating]] [[clang::nonblocking]]; // expected-error {{nonblocking(true) and allocating attributes are not compatible}}
 
-void nl_false_na_true_1() [[clang::nonblocking(false)]] [[clang::nonallocating]];
-void nl_false_na_true_2() [[clang::nonallocating]] [[clang::nonblocking(false)]];
+void nl_false_na_true_1() [[clang::blocking]] [[clang::nonallocating]];
+void nl_false_na_true_2() [[clang::nonallocating]] [[clang::blocking]];
 
-void nl_false_na_false_1() [[clang::nonblocking(false)]] [[clang::nonallocating(false)]];
-void nl_false_na_false_2() [[clang::nonallocating(false)]] [[clang::nonblocking(false)]];
+void nl_false_na_false_1() [[clang::blocking]] [[clang::allocating]];
+void nl_false_na_false_2() [[clang::allocating]] [[clang::blocking]];
 
 // --- TYPE CONVERSIONS ---
 
diff --git a/clang/test/Sema/attr-nolock-syntax.cpp b/clang/test/Sema/attr-nonblocking-syntax.cpp
similarity index 95%
rename from clang/test/Sema/attr-nolock-syntax.cpp
rename to clang/test/Sema/attr-nonblocking-syntax.cpp
index 4e486c5a973ab9..bc68c401aafd9b 100644
--- a/clang/test/Sema/attr-nolock-syntax.cpp
+++ b/clang/test/Sema/attr-nonblocking-syntax.cpp
@@ -17,10 +17,6 @@ void nl_function() [[clang::nonblocking]];
 void (*nl_func_a)() [[clang::nonblocking]];
 // CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nonblocking))'
 
-// Check alternate attribute type and placement
-__attribute__((clang_nonblocking)) void (*nl_func_b)();
-// CHECK: VarDecl {{.*}} nl_func_b 'void (*)() __attribute__((clang_nonblocking))'
-
 // On the type of the ParmVarDecl of a function parameter
 static void nlReceiver(void (*nl_func)() [[clang::nonblocking]]);
 // CHECK: ParmVarDecl {{.*}} nl_func 'void (*)() __attribute__((clang_nonblocking))'
@@ -84,12 +80,12 @@ auto nl_lambda = []() [[clang::nonblocking]] {};
 // =========================================================================================
 // Square brackets, false
 
-void nl_func_false() [[clang::nonblocking(false)]];
-// CHECK: FunctionDecl {{.*}} nl_func_false 'void () __attribute__((clang_nonblocking(false)))'
+void nl_func_false() [[clang::blocking]];
+// CHECK: FunctionDecl {{.*}} nl_func_false 'void () __attribute__((clang_blocking))'
 
 // TODO: This exposes a bug where a type attribute is lost when inferring a lambda's
 // return type.
-auto nl_lambda_false = []() [[clang::nonblocking(false)]] {};
+auto nl_lambda_false = []() [[clang::blocking]] {};
 
 } // namespace square_brackets
 
@@ -112,7 +108,9 @@ __attribute__((clang_nonblocking)) void nl_function();
 void (*nl_func_a)() __attribute__((clang_nonblocking));
 // CHECK: VarDecl {{.*}} nl_func_a 'void (*)() __attribute__((clang_nonblocking))'
 
-
+// Alternate attribute placement on VarDecl
+__attribute__((clang_nonblocking)) void (*nl_func_b)();
+// CHECK: VarDecl {{.*}} nl_func_b 'void (*)() __attribute__((clang_nonblocking))'
 
 } // namespace gnu_style
 

>From 9471aa13c30d15248da851ca496b9d6b1b3a290b Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Fri, 5 Apr 2024 09:23:15 -0700
Subject: [PATCH 23/40] Look for blocking and allocating attributes across all
 redeclarations.

---
 clang/include/clang/AST/Type.h           |  9 +++----
 clang/lib/AST/Type.cpp                   | 30 ++++++++++++++++++------
 clang/lib/AST/TypePrinter.cpp            |  2 ++
 clang/lib/Sema/AnalysisBasedWarnings.cpp | 18 +++-----------
 4 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 657f3ee6fc779c..a45e7fbbbd2922 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4534,15 +4534,12 @@ class FunctionEffect {
                                         const CXXMethodDecl &NewMethod,
                                         FunctionEffectSet NewFX) const;
 
-  /// Return true if the effect is allowed to be inferred on a Decl of the
-  /// specified type (generally a FunctionProtoType but TypeSourceInfo is
-  /// provided so any AttributedType sugar can be examined). TSI can be null
-  /// on an implicit function like a default constructor.
-  ///
+  /// Return true if the effect is allowed to be inferred on the callee,
+  /// which is either a FunctionDecl or BlockDecl.
   /// This is only used if the effect has FE_InferrableOnCallees flag set.
   /// Example: This allows nonblocking(false) to prevent inference for the
   /// function.
-  bool canInferOnFunction(QualType QT, const TypeSourceInfo *FType) const;
+  bool canInferOnFunction(const Decl &Callee) const;
 
   // Return false for success. When true is returned for a direct call, then the
   // FE_InferrableOnCallees flag may trigger inference rather than an immediate
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 070bedceebeddf..35f20a9c9f2335 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5112,17 +5112,33 @@ FunctionEffect::OverrideResult FunctionEffect::diagnoseMethodOverride(
   return OverrideResult::Ignore;
 }
 
-bool FunctionEffect::canInferOnFunction(QualType QT,
-                                        const TypeSourceInfo *FType) const {
+bool FunctionEffect::canInferOnFunction(const Decl &Callee) const {
   switch (type()) {
   case Type::NonAllocating:
   case Type::NonBlocking: {
-    // Does the sugar have nonblocking(false) / nonallocating(false) ?
-    if (QT->hasAttr(type() == Type::NonBlocking ? attr::Kind::Blocking
-                                                : attr::Kind::Allocating)) {
-      return false;
+    // Do any of the callee's Decls have type sugar for blocking or allocating?
+    for (const Decl *D : Callee.redecls()) {
+      QualType QT;
+      if (auto *FD = D->getAsFunction()) {
+        QT = FD->getType();
+      } else if (auto *BD = dyn_cast<BlockDecl>(D)) {
+        if (auto *TSI = BD->getSignatureAsWritten())
+          QT = TSI->getType();
+        else
+          continue;
+      } else
+        continue;
+
+      // c.f. Sema::getCallingConvAttributedType
+      const AttributedType *AT = QT->getAs<AttributedType>();
+      while (AT) {
+        if (AT->getAttrKind() == attr::Allocating)
+          return false;
+        if (type() == Type::NonBlocking && AT->getAttrKind() == attr::Blocking)
+          return false;
+        AT = AT->getModifiedType()->getAs<AttributedType>();
+      }
     }
-
     return true;
   }
 
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index c086f9829dc409..ffa0b8a6285c21 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -1933,6 +1933,8 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   case attr::ArmOut:
   case attr::ArmInOut:
   case attr::ArmPreserves:
+  case attr::NonBlocking:
+  case attr::NonAllocating:
     llvm_unreachable("This attribute should have been handled already");
 
   case attr::NSReturnsRetained:
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index f76571afcfa2f4..ac3cb92f988622 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2458,7 +2458,6 @@ struct CallableInfo {
   SpecialFuncType FuncType = SpecialFuncType::None;
   FunctionEffectSet Effects;
   CallType CType = CallType::Unknown;
-  QualType QT;
 
   CallableInfo(const Decl &CD, SpecialFuncType FT = SpecialFuncType::None)
       : CDecl(&CD), FuncType(FT) {
@@ -2475,16 +2474,13 @@ struct CallableInfo {
           CType = CallType::Virtual;
         }
       }
-      QT = FD->getType();
       Effects = FD->getFunctionEffects();
     } else if (auto *BD = dyn_cast<BlockDecl>(CDecl)) {
       CType = CallType::Block;
-      QT = BD->getSignatureAsWritten()->getType();
       Effects = BD->getFunctionEffects();
     } else if (auto *VD = dyn_cast<ValueDecl>(CDecl)) {
-      // ValueDecl is function, enum, or variable, so just look at the type.
-      QT = VD->getType();
-      Effects = FunctionEffectSet::get(QT);
+      // ValueDecl is function, enum, or variable, so just look at its type.
+      Effects = FunctionEffectSet::get(VD->getType());
     }
   }
 
@@ -2624,17 +2620,9 @@ class PendingFunctionAnalysis {
 
     // Check for effects we are not allowed to infer
     MutableFunctionEffectSet FX;
-    TypeSourceInfo *TSI = nullptr;
-    if (const auto *DD = dyn_cast<DeclaratorDecl>(CInfo.CDecl)) {
-      TSI = DD->getTypeSourceInfo();
-    } else if (const auto *BD = dyn_cast<BlockDecl>(CInfo.CDecl)) {
-      TSI = BD->getSignatureAsWritten();
-    }
-    // N.B. TSI can be null for things like an implicit constructor (despite
-    // having a valid QualifiedType).
 
     for (const auto &effect : AllInferrableEffectsToVerify) {
-      if (effect.canInferOnFunction(CInfo.QT, TSI)) {
+      if (effect.canInferOnFunction(*CInfo.CDecl)) {
         FX.insert(effect);
       } else {
         // Add a diagnostic for this effect if a caller were to

>From 12e213ab04899f51778bfcbe9e64d4f920606b29 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Fri, 5 Apr 2024 13:16:00 -0700
Subject: [PATCH 24/40] Reinstate the warning that nonblocking/nonallocating
 should be accompanied by noexcept.

---
 clang/include/clang/Basic/DiagnosticGroups.td |  1 +
 .../clang/Basic/DiagnosticSemaKinds.td        |  7 ++--
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 36 ++++++++++++-------
 .../test/Sema/attr-nonblocking-constraints.mm | 10 ++++++
 4 files changed, 37 insertions(+), 17 deletions(-)

diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 59eac4e2c14427..a56df9a89375f7 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1517,6 +1517,7 @@ def UnsafeBufferUsage : DiagGroup<"unsafe-buffer-usage", [UnsafeBufferUsageInCon
 // Warnings and notes related to the function effects system underlying
 // the nonblocking and nonallocating attributes.
 def FunctionEffects : DiagGroup<"function-effects">;
+def PerfConstraintImpliesNoexcept : DiagGroup<"perf-constraint-implies-noexcept">;
 
 // Warnings and notes InstallAPI verification.
 def InstallAPIViolation : DiagGroup<"installapi-violation">;
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index f2cf601b95f370..3608c9403dd341 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10856,10 +10856,9 @@ def note_func_effect_call_virtual : Note<
 def note_func_effect_call_func_ptr : Note<
   "function pointer cannot be inferred '%0'">;
 
-// TODO: Not currently being generated
-// def warn_perf_annotation_implies_noexcept : Warning<
-//  "'%0' function should be declared noexcept">,
-//  InGroup<PerfAnnotationImpliesNoexcept>;
+def warn_perf_constraint_implies_noexcept : Warning<
+  "'%0' function should be declared noexcept">,
+  InGroup<PerfConstraintImpliesNoexcept>;
 
 // TODO: Not currently being generated
 def warn_func_effect_false_on_type : Warning<
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index ac3cb92f988622..5811aab454c402 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2746,18 +2746,6 @@ class CompleteFunctionAnalysis {
   }
 };
 
-/*
-        TODO: nonblocking and nonallocating imply noexcept
-        if (auto* Method = dyn_cast<CXXMethodDecl>(CInfo.CDecl)) {
-          if (Method->getType()->castAs<FunctionProtoType>()->canThrow()
-              != clang::CT_Cannot) {
-            S.Diag(Callable->getBeginLoc(),
-              diag::warn_perf_annotation_implies_noexcept)
-              << getPerfAnnotationSpelling(CInfo.PerfAnnot);
-          }
-        }
-*/
-
 const Decl *CanonicalFunctionDecl(const Decl *D) {
   if (auto *FD = dyn_cast<FunctionDecl>(D)) {
     FD = FD->getCanonicalDecl();
@@ -2919,10 +2907,32 @@ class Analyzer {
   // Verify a single Decl. Return the pending structure if that was the result,
   // else null. This method must not recurse.
   PendingFunctionAnalysis *verifyDecl(const Decl *D) {
+    CallableInfo CInfo(*D);
+
+    // If any of the Decl's declared effects forbid throwing (e.g. nonblocking)
+    // then the function should also be declared noexcept.
+    for (const auto &Effect : CInfo.Effects) {
+      if (!(Effect.flags() & FunctionEffect::FE_ExcludeThrow))
+        continue;
+
+      const FunctionProtoType *FPT = nullptr;
+      if (auto *FD = D->getAsFunction()) {
+        FPT = FD->getType()->getAs<FunctionProtoType>();
+      } else if (auto *BD = dyn_cast<BlockDecl>(D)) {
+        if (auto *TSI = BD->getSignatureAsWritten()) {
+          FPT = TSI->getType()->getAs<FunctionProtoType>();
+        }
+      }
+      if (FPT && FPT->canThrow() != clang::CT_Cannot) {
+        Sem.Diag(D->getBeginLoc(), diag::warn_perf_constraint_implies_noexcept)
+            << Effect.name();
+      }
+      break;
+    }
+
     if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
       tmp_assert(FD->getBuiltinID() == 0);
     }
-    CallableInfo CInfo(*D);
 
     // Build a PendingFunctionAnalysis on the stack. If it turns out to be
     // complete, we'll have avoided a heap allocation; if it's incomplete, it's
diff --git a/clang/test/Sema/attr-nonblocking-constraints.mm b/clang/test/Sema/attr-nonblocking-constraints.mm
index 4be3f8c95c9ad9..e805a526a1bbd2 100644
--- a/clang/test/Sema/attr-nonblocking-constraints.mm
+++ b/clang/test/Sema/attr-nonblocking-constraints.mm
@@ -6,6 +6,9 @@
 #error "the 'nonblocking' attribute is not available"
 #endif
 
+// This diagnostic is re-enabled and exercised in isolation later in this file.
+#pragma clang diagnostic ignored "-Wperf-constraint-implies-noexcept"
+
 // --- CONSTRAINTS ---
 
 void nl1() [[clang::nonblocking]]
@@ -188,3 +191,10 @@ void nl18(void (^block)() [[clang::nonblocking]]) [[clang::nonblocking]]
 	ref();
 }
 
+
+// --- nonblocking implies noexcept ---
+#pragma clang diagnostic warning "-Wperf-constraint-implies-noexcept"
+
+void nl19() [[clang::nonblocking]] // expected-warning {{'nonblocking' function should be declared noexcept}}
+{
+}

>From 2a58ddab9a700665cf859e63afbf2e51aca3f90a Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 9 Apr 2024 16:15:19 -0700
Subject: [PATCH 25/40] Groundwork for `nonblocking(expr)`

---
 clang/include/clang/Basic/Attr.td           |   4 +-
 clang/include/clang/Sema/Sema.h             |   3 -
 clang/lib/AST/TypePrinter.cpp               |   9 ++
 clang/lib/Sema/SemaDeclAttr.cpp             |  27 -----
 clang/lib/Sema/SemaType.cpp                 | 121 ++++++++++++++------
 clang/test/Sema/attr-nonblocking-sema.cpp   |  12 +-
 clang/test/Sema/attr-nonblocking-syntax.cpp |   1 +
 7 files changed, 101 insertions(+), 76 deletions(-)

diff --git a/clang/include/clang/Basic/Attr.td b/clang/include/clang/Basic/Attr.td
index 908edba2222f88..88b94c946b382d 100644
--- a/clang/include/clang/Basic/Attr.td
+++ b/clang/include/clang/Basic/Attr.td
@@ -1407,7 +1407,7 @@ def NonBlocking : TypeAttr {
                    C23<"clang", "nonblocking">,
                    GNU<"clang_nonblocking">];
 
-  let Args = [DefaultBoolArgument<"Cond", /*default*/1>];
+  let Args = [ExprArgument<"Cond", /*optional*/1>];
   let Documentation = [NonBlockingNonAllocatingDocs];
 }
 
@@ -1415,7 +1415,7 @@ def NonAllocating : TypeAttr {
   let Spellings = [CXX11<"clang", "nonallocating">,
                    C23<"clang", "nonallocating">,
                    GNU<"clang_nonallocating">];
-  let Args = [DefaultBoolArgument<"Cond", /*default*/1>];
+  let Args = [ExprArgument<"Cond", /*optional*/1>];
   let Documentation = [NonBlockingNonAllocatingDocs];
 }
 
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 5400a62bce91d0..872947afbcf417 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -3764,9 +3764,6 @@ class Sema final {
                                       StringRef &Str,
                                       SourceLocation *ArgLocation = nullptr);
 
-  bool checkBoolExprArgumentAttr(const ParsedAttr &Attr, unsigned ArgNum,
-                                 bool &Value);
-
   /// Determine if type T is a valid subject for a nonnull and similar
   /// attributes. By default, we look through references (the behavior used by
   /// nonnull), but if the second parameter is true, then we treat a reference
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index ffa0b8a6285c21..89a66cd0700299 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -1877,6 +1877,15 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
     return;
   }
 
+  if (T->getAttrKind() == attr::NonBlocking) {
+    OS << " [[clang::nonblocking(...)]]";
+    return;
+  }
+  if (T->getAttrKind() == attr::NonAllocating) {
+    OS << " [[clang::nonallocating(...)]]";
+    return;
+  }
+
   if (T->getAttrKind() == attr::ArmStreaming) {
     OS << "__arm_streaming";
     return;
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 3cc73db06740ed..8bce04640e748e 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -395,33 +395,6 @@ bool Sema::checkStringLiteralArgumentAttr(const ParsedAttr &AL, unsigned ArgNum,
   return checkStringLiteralArgumentAttr(AL, ArgExpr, Str, ArgLocation);
 }
 
-/// Check if the argument \p ArgNum of \p Attr is a compile-time constant
-/// integer (boolean) expression. If not, emit an error and return false.
-bool Sema::checkBoolExprArgumentAttr(const ParsedAttr &AL, unsigned ArgNum,
-                                     bool &Value) {
-  if (AL.isInvalid()) {
-    return false;
-  }
-  Expr *ArgExpr = AL.getArgAsExpr(ArgNum);
-  SourceLocation ErrorLoc(AL.getLoc());
-
-  if (AL.isArgIdent(ArgNum)) {
-    IdentifierLoc *IL = AL.getArgAsIdent(ArgNum);
-    ErrorLoc = IL->Loc;
-  } else if (ArgExpr != nullptr) {
-    if (const std::optional<llvm::APSInt> MaybeVal =
-            ArgExpr->getIntegerConstantExpr(Context, &ErrorLoc)) {
-      Value = MaybeVal->getBoolValue();
-      return true;
-    }
-  }
-
-  AL.setInvalid();
-  Diag(ErrorLoc, diag::err_attribute_argument_n_type)
-      << AL << ArgNum << AANT_ArgumentConstantExpr;
-  return false;
-}
-
 /// Applies the given attribute to the Decl without performing any
 /// additional semantic checking.
 template <typename AttrType>
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 80123ba9a59a1b..b1416c0d365c07 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -175,7 +175,7 @@ static void diagnoseBadTypeAttribute(Sema &S, const ParsedAttr &attr,
   case ParsedAttr::AT_TypeNullableResult:                                      \
   case ParsedAttr::AT_TypeNullUnspecified
 
-enum class BoolAttrState : uint8_t { Unseen, False, True };
+enum class BoolAttrState : uint8_t { Unseen, False, True, Dependent };
 
 namespace {
   /// An object which stores processing state for the entire
@@ -7987,10 +7987,6 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
   if (!unwrapped.isFunctionType())
     return false;
 
-  const bool isNonBlocking = PAttr.getKind() == ParsedAttr::AT_NonBlocking ||
-                             PAttr.getKind() == ParsedAttr::AT_Blocking;
-  Sema &S = state.getSema();
-
   // Require FunctionProtoType
   auto *FPT = unwrapped.get()->getAs<FunctionProtoType>();
   if (FPT == nullptr) {
@@ -7998,68 +7994,115 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
     return false;
   }
 
-  bool Cond = true; // default
+  // Parse the new  attribute.
+  // non/blocking or non/allocating? Or dependent?
+  const bool isNonBlocking = PAttr.getKind() == ParsedAttr::AT_NonBlocking ||
+                             PAttr.getKind() == ParsedAttr::AT_Blocking;
+  Sema &S = state.getSema();
+
+  BoolAttrState NewState = BoolAttrState::Unseen;
+  Expr *CondExpr = nullptr; // only valid if dependent
 
   if (PAttr.getKind() == ParsedAttr::AT_NonBlocking ||
       PAttr.getKind() == ParsedAttr::AT_NonAllocating) {
     // Parse the conditional expression, if any
-    // TODO: There's a better way to do this. See PR feedback.
-    // TODO: Handle a type-dependent expression.
     if (PAttr.getNumArgs() > 0) {
-      if (!S.checkBoolExprArgumentAttr(PAttr, 0, Cond)) {
-        PAttr.setInvalid();
-        return false;
+      // see checkFunctionConditionAttr, Sema::CheckCXXBooleanCondition
+      CondExpr = PAttr.getArgAsExpr(0);
+      if (!CondExpr->isTypeDependent()) {
+        ExprResult E = S.PerformContextuallyConvertToBool(CondExpr);
+        if (E.isInvalid())
+          return false;
+        CondExpr = E.get();
+        if (!CondExpr->isValueDependent()) {
+          llvm::APSInt CondInt;
+          E = S.VerifyIntegerConstantExpression(
+            E.get(), &CondInt,
+            // TODO: have our own diagnostic
+            diag::err_constexpr_if_condition_expression_is_not_constant);
+          if (E.isInvalid()) {
+            return false;
+          }
+          NewState = (CondInt != 0) ? BoolAttrState::True : BoolAttrState::False;
+        } else {
+          NewState = BoolAttrState::Dependent;
+        }
+      } else {
+        NewState = BoolAttrState::Dependent;
       }
+    } else {
+      NewState = BoolAttrState::True;
     }
   } else {
-    Cond = false;
-  }
-
-  FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
+    // This is the `blocking` or `allocating` attribute.
+    NewState = BoolAttrState::False;
+  }
+
+  auto attrName = [](bool NB, BoolAttrState value) {
+    switch (value) {
+    case BoolAttrState::False:
+      return NB ? "blocking" : "allocating";
+    case BoolAttrState::True:
+      return NB ? "nonblocking" : "nonallocating";
+    case BoolAttrState::Dependent:
+      return NB ? "nonblocking(expr)" : "nonallocating(expr)";
+    default:
+      llvm_unreachable("'unseen' shouldn't happen");
+    }
+  };
 
-  auto incompatible = [&](StringRef attrTrue, StringRef attrFalse) {
+  // Diagnose the newly provided attribute as incompatible with a previous one.
+  auto incompatible = [&](bool prevNB, BoolAttrState prevValue) {
     Sema &S = state.getSema();
     S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
-        << attrTrue << attrFalse << false;
+        << attrName(isNonBlocking, NewState) << attrName(prevNB, prevValue) << false;
     // we don't necessarily have the location of the previous attribute,
     // so no note.
     PAttr.setInvalid();
     return true;
   };
 
-  // check nonblocking(true) against blocking, and same for
-  // nonallocating
-  const BoolAttrState newState =
-      Cond ? BoolAttrState::True : BoolAttrState::False;
-  const BoolAttrState oppositeNewState =
-      Cond ? BoolAttrState::False : BoolAttrState::True;
+  const BoolAttrState PrevState = isNonBlocking ? state.getParsedNonBlocking() : 
+    state.getParsedNonAllocating();
+  if (PrevState != BoolAttrState::Unseen) {
+    // Only one attribute per constraint is allowed.
+    return incompatible(isNonBlocking, PrevState);
+  }
+
   if (isNonBlocking) {
-    if (state.getParsedNonBlocking() == oppositeNewState) {
-      return incompatible("nonblocking(true)", "blocking");
-    }
     // also check nonblocking(true) against allocating
-    if (Cond && state.getParsedNonAllocating() == BoolAttrState::False) {
-      return incompatible("nonblocking(true)", "allocating");
+    if (NewState == BoolAttrState::True && state.getParsedNonAllocating() == BoolAttrState::False) {
+      return incompatible(false, BoolAttrState::False);
     }
-    state.setParsedNonBlocking(newState);
+    state.setParsedNonBlocking(NewState);
   } else {
-    if (state.getParsedNonAllocating() == oppositeNewState) {
-      return incompatible("nonallocating(true)", "allocating");
-    }
     // also check nonblocking(true) against allocating
     if (state.getParsedNonBlocking() == BoolAttrState::True) {
-      if (!Cond) {
-        return incompatible("nonblocking(true)", "allocating");
+      if (NewState == BoolAttrState::False) {
+        return incompatible(true, BoolAttrState::True);
       }
       // Ignore nonallocating(true) since we already have nonblocking(true).
       return true;
     }
-    state.setParsedNonAllocating(newState);
+    state.setParsedNonAllocating(NewState);
   }
 
-  if (!Cond) {
-    // blocking and allocating are represented as sugar,
-    // with AttributedType
+  if (NewState == BoolAttrState::Dependent) {
+    // nonblocking(expr)/nonallocating(expr) are represented as AttributedType sugar,
+    // using those attributes. TODO: Currently no one else tries to find it there,
+    // and this may turn out to be the wrong place.
+    Attr *A = nullptr;
+    if (isNonBlocking) {
+      A = NonBlockingAttr::Create(S.Context, CondExpr);
+    } else {
+      A = NonAllocatingAttr::Create(S.Context, CondExpr);
+    }
+    type = state.getAttributedType(A, type, type);
+    return true;
+  }
+  if (NewState == BoolAttrState::False) {
+    // blocking and allocating are represented as AttributedType sugar,
+    // using those attributes.
     Attr *A = nullptr;
     if (isNonBlocking) {
       A = BlockingAttr::Create(S.Context);
@@ -8077,6 +8120,8 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
                                      : FunctionEffect::Type::NonAllocating);
 
   MutableFunctionEffectSet NewFX(NewEffect);
+  FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
+
   if (EPI.FunctionEffects) {
     // Preserve any previous effects - except nonallocating, when we are adding
     // nonblocking
diff --git a/clang/test/Sema/attr-nonblocking-sema.cpp b/clang/test/Sema/attr-nonblocking-sema.cpp
index a8e725b3a4b613..ba86420d6c8145 100644
--- a/clang/test/Sema/attr-nonblocking-sema.cpp
+++ b/clang/test/Sema/attr-nonblocking-sema.cpp
@@ -14,17 +14,17 @@ struct [[clang::nonblocking]] nl_struct2 {}; // expected-error {{'nonblocking' a
 // --- ATTRIBUTE SYNTAX: COMBINATIONS ---
 // Check invalid combinations of nonblocking/nonallocating attributes
 
-void nl_true_false_1() [[clang::nonblocking(true)]] [[clang::blocking]]; // expected-error {{nonblocking(true) and blocking attributes are not compatible}}
-void nl_true_false_2() [[clang::blocking]] [[clang::nonblocking(true)]]; // expected-error {{nonblocking(true) and blocking attributes are not compatible}}
+void nl_true_false_1() [[clang::nonblocking(true)]] [[clang::blocking]]; // expected-error {{blocking and nonblocking attributes are not compatible}}
+void nl_true_false_2() [[clang::blocking]] [[clang::nonblocking(true)]]; // expected-error {{nonblocking and blocking attributes are not compatible}}
 
-void na_true_false_1() [[clang::nonallocating(true)]] [[clang::allocating]]; // expected-error {{nonallocating(true) and allocating attributes are not compatible}}
-void na_true_false_2() [[clang::allocating]] [[clang::nonallocating(true)]]; // expected-error {{nonallocating(true) and allocating attributes are not compatible}}
+void na_true_false_1() [[clang::nonallocating(true)]] [[clang::allocating]]; // expected-error {{allocating and nonallocating attributes are not compatible}}
+void na_true_false_2() [[clang::allocating]] [[clang::nonallocating(true)]]; // expected-error {{nonallocating and allocating attributes are not compatible}}
 
 void nl_true_na_true_1() [[clang::nonblocking]] [[clang::nonallocating]];
 void nl_true_na_true_2() [[clang::nonallocating]] [[clang::nonblocking]];
 
-void nl_true_na_false_1() [[clang::nonblocking]] [[clang::allocating]]; // expected-error {{nonblocking(true) and allocating attributes are not compatible}}
-void nl_true_na_false_2() [[clang::allocating]] [[clang::nonblocking]]; // expected-error {{nonblocking(true) and allocating attributes are not compatible}}
+void nl_true_na_false_1() [[clang::nonblocking]] [[clang::allocating]]; // expected-error {{allocating and nonblocking attributes are not compatible}}
+void nl_true_na_false_2() [[clang::allocating]] [[clang::nonblocking]]; // expected-error {{nonblocking and allocating attributes are not compatible}}
 
 void nl_false_na_true_1() [[clang::blocking]] [[clang::nonallocating]];
 void nl_false_na_true_2() [[clang::nonallocating]] [[clang::blocking]];
diff --git a/clang/test/Sema/attr-nonblocking-syntax.cpp b/clang/test/Sema/attr-nonblocking-syntax.cpp
index bc68c401aafd9b..5a451f23f291fd 100644
--- a/clang/test/Sema/attr-nonblocking-syntax.cpp
+++ b/clang/test/Sema/attr-nonblocking-syntax.cpp
@@ -3,6 +3,7 @@
 // Make sure that the attribute gets parsed and attached to the correct AST elements.
 
 #pragma clang diagnostic ignored "-Wunused-variable"
+#pragma clang diagnostic ignored "-Wperf-constraint-implies-noexcept"
 
 // =========================================================================================
 // Square brackets, true

>From e942a902a5a0d96af442f9fa2c39b59afd569dd0 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 10 Apr 2024 11:31:36 -0700
Subject: [PATCH 26/40] Low-hanging fruit in review feedback.

---
 clang/include/clang/AST/Type.h           | 64 +++++++++----------
 clang/lib/AST/Type.cpp                   | 78 ++++++++++++------------
 clang/lib/Sema/AnalysisBasedWarnings.cpp |  9 +--
 clang/lib/Sema/Sema.cpp                  |  3 +-
 clang/lib/Sema/SemaDecl.cpp              |  5 +-
 clang/lib/Sema/SemaDeclCXX.cpp           |  5 +-
 clang/lib/Sema/SemaType.cpp              | 54 ++++++++--------
 clang/lib/Serialization/ASTReader.cpp    |  2 +-
 8 files changed, 110 insertions(+), 110 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index a45e7fbbbd2922..e4f0c545f80b98 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4435,8 +4435,6 @@ class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
 
 // ------------------------------------------------------------------------------
 
-// TODO: Should FunctionEffect be located elsewhere, where Decl is not
-// forward-declared?
 class Decl;
 class CXXMethodDecl;
 class FunctionEffectSet;
@@ -4457,7 +4455,7 @@ class FunctionEffect {
   // test a caller-specified bit. There are some potential optimizations that
   // would OR together the bits of multiple effects.)
   using Flags = unsigned;
-  enum FlagBit : unsigned {
+  enum FlagBit : Flags {
     // Can verification inspect callees' implementations? (e.g. nonblocking:
     // yes, tcb+types: no)
     FE_InferrableOnCallees = 0x1,
@@ -4475,15 +4473,15 @@ class FunctionEffect {
   enum class OverrideResult {
     Ignore,
     Warn,
-    Propagate // Base method's effects are merged with those of the override.
+    Merge // Base method's effects are merged with those of the override.
   };
 
 private:
-  // For uniqueness, currently only Type_ is significant.
+  // For uniqueness, currently only EfType is significant.
 
   LLVM_PREFERRED_TYPE(Type)
-  unsigned Type_ : 2;
-  Flags Flags_ : 8; // A constant function of Type but cached here.
+  unsigned EfType : 2;
+  Flags EfFlags : 8; // A constant function of Type but cached here.
 
   // Expansion: for hypothetical TCB+types, there could be one Type for TCB,
   // then ~16(?) bits "Subtype" to map to a specific named TCB. Subtype would
@@ -4494,45 +4492,42 @@ class FunctionEffect {
   [[maybe_unused]] unsigned Padding : 22;
 
 public:
-  using CalleeDeclOrType =
-      llvm::PointerUnion<const Decl *, const FunctionProtoType *>;
-
-  FunctionEffect() : Type_(unsigned(Type::None)), Flags_(0), Padding(0) {}
+  FunctionEffect() : EfType(unsigned(Type::None)), EfFlags(0), Padding(0) {}
 
   explicit FunctionEffect(Type T);
 
   /// The type of the effect.
-  Type type() const { return Type(Type_); }
+  Type type() const { return Type(EfType); }
 
   /// Flags describing behaviors of the effect.
-  Flags flags() const { return Flags_; }
+  Flags flags() const { return EfFlags; }
 
   /// The description printed in diagnostics, e.g. 'nonblocking'.
   StringRef name() const;
 
   /// A hashable representation.
-  uint32_t opaqueRepr() const { return Type_ | (Flags_ << 2u); }
+  uint32_t opaqueRepr() const { return EfType | (EfFlags << 2u); }
 
   /// Return true if adding or removing the effect as part of a type conversion
   /// should generate a diagnostic.
-  bool diagnoseConversion(bool Adding, QualType OldType,
-                          FunctionEffectSet OldFX, QualType NewType,
-                          FunctionEffectSet NewFX) const;
+  bool shouldDiagnoseConversion(bool Adding, QualType OldType,
+                                FunctionEffectSet OldFX, QualType NewType,
+                                FunctionEffectSet NewFX) const;
 
   /// Return true if adding or removing the effect in a redeclaration should
   /// generate a diagnostic.
-  bool diagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
-                             FunctionEffectSet OldFX,
-                             const FunctionDecl &NewFunction,
-                             FunctionEffectSet NewFX) const;
+  bool shouldDiagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
+                                   FunctionEffectSet OldFX,
+                                   const FunctionDecl &NewFunction,
+                                   FunctionEffectSet NewFX) const;
 
   /// Return true if adding or removing the effect in a C++ virtual method
   /// override should generate a diagnostic.
-  OverrideResult diagnoseMethodOverride(bool Adding,
-                                        const CXXMethodDecl &OldMethod,
-                                        FunctionEffectSet OldFX,
-                                        const CXXMethodDecl &NewMethod,
-                                        FunctionEffectSet NewFX) const;
+  OverrideResult shouldDiagnoseMethodOverride(bool Adding,
+                                              const CXXMethodDecl &OldMethod,
+                                              FunctionEffectSet OldFX,
+                                              const CXXMethodDecl &NewMethod,
+                                              FunctionEffectSet NewFX) const;
 
   /// Return true if the effect is allowed to be inferred on the callee,
   /// which is either a FunctionDecl or BlockDecl.
@@ -4545,16 +4540,17 @@ class FunctionEffect {
   // FE_InferrableOnCallees flag may trigger inference rather than an immediate
   // diagnostic. Caller should be assumed to have the effect (it may not have it
   // explicitly when inferring).
-  bool diagnoseFunctionCall(bool Direct, FunctionEffectSet CalleeFX) const;
+  bool shouldDiagnoseFunctionCall(bool Direct,
+                                  FunctionEffectSet CalleeFX) const;
 
   friend bool operator==(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.Type_ == RHS.Type_;
+    return LHS.EfType == RHS.EfType;
   }
   friend bool operator!=(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.Type_ != RHS.Type_;
+    return LHS.EfType != RHS.EfType;
   }
   friend bool operator<(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.Type_ < RHS.Type_;
+    return LHS.EfType < RHS.EfType;
   }
 };
 
@@ -4573,7 +4569,7 @@ class MutableFunctionEffectSet : public SmallVector<FunctionEffect, 4> {
   /// Maintains order/uniquenesss.
   void insert(const FunctionEffect &Effect);
 
-  MutableFunctionEffectSet &operator|=(FunctionEffectSet RHS);
+  MutableFunctionEffectSet &insertMultiple(FunctionEffectSet RHS);
 
   operator llvm::ArrayRef<FunctionEffect>() const { return {data(), size()}; }
 };
@@ -4625,10 +4621,8 @@ class FunctionEffectSet {
 
   void dump(llvm::raw_ostream &OS) const;
 
-  /// Intersection.
-  MutableFunctionEffectSet operator&(const FunctionEffectSet &RHS) const;
-  /// Difference.
-  MutableFunctionEffectSet operator-(const FunctionEffectSet &RHS) const;
+  MutableFunctionEffectSet intersection(const FunctionEffectSet &RHS) const;
+  MutableFunctionEffectSet difference(const FunctionEffectSet &RHS) const;
 
   static FunctionEffectSet getUnion(ASTContext &C, const FunctionEffectSet &LHS,
                                     const FunctionEffectSet &RHS);
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 35f20a9c9f2335..5d22d058070ab6 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5026,39 +5026,41 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
 }
 
 FunctionEffect::FunctionEffect(Type T)
-    : Type_(static_cast<unsigned>(T)), Flags_(0), Padding(0) {
+    : EfType(static_cast<unsigned>(T)), EfFlags(0), Padding(0) {
   switch (T) {
   case Type::NonBlocking:
-    Flags_ = FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
-             FE_ExcludeObjCMessageSend | FE_ExcludeStaticLocalVars |
-             FE_ExcludeThreadLocalVars;
+    EfFlags = FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
+              FE_ExcludeObjCMessageSend | FE_ExcludeStaticLocalVars |
+              FE_ExcludeThreadLocalVars;
     break;
 
   case Type::NonAllocating:
     // Same as NonBlocking, except without FE_ExcludeStaticLocalVars
-    Flags_ = FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
-             FE_ExcludeObjCMessageSend | FE_ExcludeThreadLocalVars;
+    EfFlags = FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
+              FE_ExcludeObjCMessageSend | FE_ExcludeThreadLocalVars;
     break;
-  default:
+  case Type::None:
     break;
   }
+  llvm_unreachable("unknown effect type");
 }
 
 StringRef FunctionEffect::name() const {
   switch (type()) {
-  default:
-    return "";
   case Type::NonBlocking:
     return "nonblocking";
   case Type::NonAllocating:
     return "nonallocating";
+  case Type::None:
+    break;
   }
+  llvm_unreachable("unknown effect type");
 }
 
-bool FunctionEffect::diagnoseConversion(bool Adding, QualType OldType,
-                                        FunctionEffectSet OldFX,
-                                        QualType NewType,
-                                        FunctionEffectSet NewFX) const {
+bool FunctionEffect::shouldDiagnoseConversion(bool Adding, QualType OldType,
+                                              FunctionEffectSet OldFX,
+                                              QualType NewType,
+                                              FunctionEffectSet NewFX) const {
 
   switch (type()) {
   case Type::NonAllocating:
@@ -5074,30 +5076,28 @@ bool FunctionEffect::diagnoseConversion(bool Adding, QualType OldType,
   case Type::NonBlocking:
     // nonblocking can't be added (spoofed) during a conversion
     return Adding;
-  default:
+  case Type::None:
     break;
   }
-  return false;
+  llvm_unreachable("unknown effect type");
 }
 
-bool FunctionEffect::diagnoseRedeclaration(bool Adding,
-                                           const FunctionDecl &OldFunction,
-                                           FunctionEffectSet OldFX,
-                                           const FunctionDecl &NewFunction,
-                                           FunctionEffectSet NewFX) const {
+bool FunctionEffect::shouldDiagnoseRedeclaration(
+    bool Adding, const FunctionDecl &OldFunction, FunctionEffectSet OldFX,
+    const FunctionDecl &NewFunction, FunctionEffectSet NewFX) const {
   switch (type()) {
   case Type::NonAllocating:
   case Type::NonBlocking:
     // nonblocking/nonallocating can't be removed in a redeclaration
     // adding -> false, removing -> true (diagnose)
     return !Adding;
-  default:
+  case Type::None:
     break;
   }
-  return false;
+  llvm_unreachable("unknown effect type");
 }
 
-FunctionEffect::OverrideResult FunctionEffect::diagnoseMethodOverride(
+FunctionEffect::OverrideResult FunctionEffect::shouldDiagnoseMethodOverride(
     bool Adding, const CXXMethodDecl &OldMethod, FunctionEffectSet OldFX,
     const CXXMethodDecl &NewMethod, FunctionEffectSet NewFX) const {
   switch (type()) {
@@ -5105,17 +5105,17 @@ FunctionEffect::OverrideResult FunctionEffect::diagnoseMethodOverride(
   case Type::NonBlocking:
     // if added on an override, that's fine and not diagnosed.
     // if missing from an override (removed), propagate from base to derived.
-    return Adding ? OverrideResult::Ignore : OverrideResult::Propagate;
-  default:
+    return Adding ? OverrideResult::Ignore : OverrideResult::Merge;
+  case Type::None:
     break;
   }
-  return OverrideResult::Ignore;
+  llvm_unreachable("unknown effect type");
 }
 
 bool FunctionEffect::canInferOnFunction(const Decl &Callee) const {
   switch (type()) {
   case Type::NonAllocating:
-  case Type::NonBlocking: {
+  case Type::NonBlocking:
     // Do any of the callee's Decls have type sugar for blocking or allocating?
     for (const Decl *D : Callee.redecls()) {
       QualType QT;
@@ -5140,16 +5140,14 @@ bool FunctionEffect::canInferOnFunction(const Decl &Callee) const {
       }
     }
     return true;
-  }
-
-  default:
+  case Type::None:
     break;
   }
-  return false;
+  llvm_unreachable("unknown effect type");
 }
 
-bool FunctionEffect::diagnoseFunctionCall(bool Direct,
-                                          FunctionEffectSet CalleeFX) const {
+bool FunctionEffect::shouldDiagnoseFunctionCall(
+    bool Direct, FunctionEffectSet CalleeFX) const {
   switch (type()) {
   case Type::NonAllocating:
   case Type::NonBlocking: {
@@ -5164,10 +5162,10 @@ bool FunctionEffect::diagnoseFunctionCall(bool Direct,
     }
     return true; // warning
   }
-  default:
+  case Type::None:
     break;
   }
-  return false;
+  llvm_unreachable("unknown effect type");
 }
 
 // =====
@@ -5185,7 +5183,7 @@ void MutableFunctionEffectSet::insert(const FunctionEffect &Effect) {
 }
 
 MutableFunctionEffectSet &
-MutableFunctionEffectSet::operator|=(FunctionEffectSet RHS) {
+MutableFunctionEffectSet::insertMultiple(FunctionEffectSet RHS) {
   // TODO: For large RHS sets, use set_union or a custom insert-in-place
   for (const auto &Effect : RHS) {
     insert(Effect);
@@ -5215,7 +5213,7 @@ FunctionEffectSet FunctionEffectSet::getUnion(ASTContext &C,
 }
 
 MutableFunctionEffectSet
-FunctionEffectSet::operator&(const FunctionEffectSet &RHS) const {
+FunctionEffectSet::intersection(const FunctionEffectSet &RHS) const {
   const FunctionEffectSet &LHS = *this;
   if (LHS.empty() || RHS.empty()) {
     return {};
@@ -5254,17 +5252,17 @@ FunctionEffectSet::differences(const FunctionEffectSet &Old,
                                const FunctionEffectSet &New) {
   // TODO: Could be a one-pass algorithm.
   Differences Result;
-  for (const auto &Effect : (New - Old)) {
+  for (const auto &Effect : New.difference(Old)) {
     Result.emplace_back(Effect, true);
   }
-  for (const auto &Effect : (Old - New)) {
+  for (const auto &Effect : Old.difference(New)) {
     Result.emplace_back(Effect, false);
   }
   return Result;
 }
 
 MutableFunctionEffectSet
-FunctionEffectSet::operator-(const FunctionEffectSet &RHS) const {
+FunctionEffectSet::difference(const FunctionEffectSet &RHS) const {
   const FunctionEffectSet &LHS = *this;
   MutableFunctionEffectSet Result;
 
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 5811aab454c402..008d1798f36282 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2636,7 +2636,8 @@ class PendingFunctionAnalysis {
     }
     // FX is now the set of inferrable effects which are not prohibited
     FXToInfer = Ctx.getUniquedFunctionEffectSet(
-        Ctx.getUniquedFunctionEffectSet(FX) - DeclaredVerifiableEffects);
+        Ctx.getUniquedFunctionEffectSet(FX).difference(
+            DeclaredVerifiableEffects));
   }
 
   // Hide the way that diagnostics for explicitly required effects vs. inferred
@@ -2721,7 +2722,7 @@ class CompleteFunctionAnalysis {
                            FunctionEffectSet funcFX,
                            FunctionEffectSet AllInferrableEffectsToVerify) {
     MutableFunctionEffectSet verified;
-    verified |= funcFX;
+    verified.insertMultiple(funcFX);
     for (const auto &effect : AllInferrableEffectsToVerify) {
       if (pending.diagnosticForInferrableEffect(effect) == nullptr) {
         verified.insert(effect);
@@ -3043,7 +3044,7 @@ class Analyzer {
     auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
       const auto Flags = Effect.flags();
       const bool diagnose =
-          Effect.diagnoseFunctionCall(DirectCall, CalleeEffects);
+          Effect.shouldDiagnoseFunctionCall(DirectCall, CalleeEffects);
       if (diagnose) {
         // If inference is not allowed, or the target is indirect (virtual
         // method/function ptr?), generate a diagnostic now.
@@ -3318,7 +3319,7 @@ class Analyzer {
 
       auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
         if (FPT == nullptr ||
-            Effect.diagnoseFunctionCall(
+            Effect.shouldDiagnoseFunctionCall(
                 /*direct=*/false, FPT->getFunctionEffects())) {
           addDiagnosticInner(Inferring, Effect,
                              DiagnosticID::CallsDisallowedExpr,
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 2cb1b931cf6fa4..01d334f8d8af90 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -596,7 +596,8 @@ void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
     for (const auto &Item : FunctionEffectSet::differences(SrcFX, DstFX)) {
       const FunctionEffect &Effect = Item.first;
       const bool Adding = Item.second;
-      if (Effect.diagnoseConversion(Adding, SrcType, SrcFX, DstType, DstFX)) {
+      if (Effect.shouldDiagnoseConversion(Adding, SrcType, SrcFX, DstType,
+                                          DstFX)) {
         Diag(Loc, Adding ? diag::warn_invalid_add_func_effects
                          : diag::warn_invalid_remove_func_effects)
             << Effect.name();
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index f68e207805b4d1..2108ee75ddc670 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3928,7 +3928,8 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
     for (const auto &Item : Diffs) {
       const FunctionEffect &Effect = Item.first;
       const bool Adding = Item.second;
-      if (Effect.diagnoseRedeclaration(Adding, *Old, OldFX, *New, NewFX)) {
+      if (Effect.shouldDiagnoseRedeclaration(Adding, *Old, OldFX, *New,
+                                             NewFX)) {
         Diag(New->getLocation(),
              diag::warn_mismatched_func_effect_redeclaration)
             << Effect.name();
@@ -11151,7 +11152,7 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
     return;
   }
 
-  AllEffectsToVerify |= FX;
+  AllEffectsToVerify.insertMultiple(FX);
 
   // Record the declaration for later analysis.
   DeclsWithEffectsToVerify.push_back(D);
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index da061e25fe3136..04ec7ee7ae7027 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18335,7 +18335,8 @@ bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
     for (const auto &Item : Diffs) {
       const FunctionEffect &Effect = Item.first;
       const bool Adding = Item.second;
-      switch (Effect.diagnoseMethodOverride(Adding, *Old, OldFX, *New, NewFX)) {
+      switch (Effect.shouldDiagnoseMethodOverride(Adding, *Old, OldFX, *New,
+                                                  NewFX)) {
       case FunctionEffect::OverrideResult::Ignore:
         break;
       case FunctionEffect::OverrideResult::Warn:
@@ -18345,7 +18346,7 @@ bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
         // TODO: It would be nice to have a FIXIT here!
         AnyDiags = true;
         break;
-      case FunctionEffect::OverrideResult::Propagate: {
+      case FunctionEffect::OverrideResult::Merge: {
         auto MergedFX = FunctionEffectSet::getUnion(Context, OldFX, NewFX);
 
         FunctionProtoType::ExtProtoInfo EPI = NewFT->getExtProtoInfo();
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index b1416c0d365c07..d00752822bfcb9 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -7980,15 +7980,15 @@ static Attr *getCCTypeAttr(ASTContext &Ctx, ParsedAttr &Attr) {
 }
 
 static bool
-handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
-                                       ParsedAttr &PAttr, QualType &type,
-                                       FunctionTypeUnwrapper &unwrapped) {
+handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
+                                       ParsedAttr &PAttr, QualType &QT,
+                                       FunctionTypeUnwrapper &Unwrapped) {
   // Delay if this is not a function type.
-  if (!unwrapped.isFunctionType())
+  if (!Unwrapped.isFunctionType())
     return false;
 
   // Require FunctionProtoType
-  auto *FPT = unwrapped.get()->getAs<FunctionProtoType>();
+  auto *FPT = Unwrapped.get()->getAs<FunctionProtoType>();
   if (FPT == nullptr) {
     // TODO: special diagnostic?
     return false;
@@ -7998,7 +7998,7 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
   // non/blocking or non/allocating? Or dependent?
   const bool isNonBlocking = PAttr.getKind() == ParsedAttr::AT_NonBlocking ||
                              PAttr.getKind() == ParsedAttr::AT_Blocking;
-  Sema &S = state.getSema();
+  Sema &S = TPState.getSema();
 
   BoolAttrState NewState = BoolAttrState::Unseen;
   Expr *CondExpr = nullptr; // only valid if dependent
@@ -8017,13 +8017,14 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
         if (!CondExpr->isValueDependent()) {
           llvm::APSInt CondInt;
           E = S.VerifyIntegerConstantExpression(
-            E.get(), &CondInt,
-            // TODO: have our own diagnostic
-            diag::err_constexpr_if_condition_expression_is_not_constant);
+              E.get(), &CondInt,
+              // TODO: have our own diagnostic
+              diag::err_constexpr_if_condition_expression_is_not_constant);
           if (E.isInvalid()) {
             return false;
           }
-          NewState = (CondInt != 0) ? BoolAttrState::True : BoolAttrState::False;
+          NewState =
+              (CondInt != 0) ? BoolAttrState::True : BoolAttrState::False;
         } else {
           NewState = BoolAttrState::Dependent;
         }
@@ -8053,17 +8054,18 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
 
   // Diagnose the newly provided attribute as incompatible with a previous one.
   auto incompatible = [&](bool prevNB, BoolAttrState prevValue) {
-    Sema &S = state.getSema();
     S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
-        << attrName(isNonBlocking, NewState) << attrName(prevNB, prevValue) << false;
+        << attrName(isNonBlocking, NewState) << attrName(prevNB, prevValue)
+        << false;
     // we don't necessarily have the location of the previous attribute,
     // so no note.
     PAttr.setInvalid();
     return true;
   };
 
-  const BoolAttrState PrevState = isNonBlocking ? state.getParsedNonBlocking() : 
-    state.getParsedNonAllocating();
+  const BoolAttrState PrevState = isNonBlocking
+                                      ? TPState.getParsedNonBlocking()
+                                      : TPState.getParsedNonAllocating();
   if (PrevState != BoolAttrState::Unseen) {
     // Only one attribute per constraint is allowed.
     return incompatible(isNonBlocking, PrevState);
@@ -8071,35 +8073,37 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
 
   if (isNonBlocking) {
     // also check nonblocking(true) against allocating
-    if (NewState == BoolAttrState::True && state.getParsedNonAllocating() == BoolAttrState::False) {
+    if (NewState == BoolAttrState::True &&
+        TPState.getParsedNonAllocating() == BoolAttrState::False) {
       return incompatible(false, BoolAttrState::False);
     }
-    state.setParsedNonBlocking(NewState);
+    TPState.setParsedNonBlocking(NewState);
   } else {
     // also check nonblocking(true) against allocating
-    if (state.getParsedNonBlocking() == BoolAttrState::True) {
+    if (TPState.getParsedNonBlocking() == BoolAttrState::True) {
       if (NewState == BoolAttrState::False) {
         return incompatible(true, BoolAttrState::True);
       }
       // Ignore nonallocating(true) since we already have nonblocking(true).
       return true;
     }
-    state.setParsedNonAllocating(NewState);
+    TPState.setParsedNonAllocating(NewState);
   }
 
   if (NewState == BoolAttrState::Dependent) {
-    // nonblocking(expr)/nonallocating(expr) are represented as AttributedType sugar,
-    // using those attributes. TODO: Currently no one else tries to find it there,
-    // and this may turn out to be the wrong place.
+    // nonblocking(expr)/nonallocating(expr) are represented as AttributedType
+    // sugar, using those attributes. TODO: Currently no one else tries to find
+    // it there, and this may turn out to be the wrong place.
     Attr *A = nullptr;
     if (isNonBlocking) {
       A = NonBlockingAttr::Create(S.Context, CondExpr);
     } else {
       A = NonAllocatingAttr::Create(S.Context, CondExpr);
     }
-    type = state.getAttributedType(A, type, type);
+    QT = TPState.getAttributedType(A, QT, QT);
     return true;
   }
+
   if (NewState == BoolAttrState::False) {
     // blocking and allocating are represented as AttributedType sugar,
     // using those attributes.
@@ -8109,7 +8113,7 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
     } else {
       A = AllocatingAttr::Create(S.Context);
     }
-    type = state.getAttributedType(A, type, type);
+    QT = TPState.getAttributedType(A, QT, QT);
     return true;
   }
 
@@ -8133,10 +8137,10 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &state,
   }
 
   EPI.FunctionEffects =
-      state.getSema().getASTContext().getUniquedFunctionEffectSet(NewFX);
+      TPState.getSema().getASTContext().getUniquedFunctionEffectSet(NewFX);
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
                                                FPT->getParamTypes(), EPI);
-  type = unwrapped.wrap(S, newtype->getAs<FunctionType>());
+  QT = Unwrapped.wrap(S, newtype->getAs<FunctionType>());
   return true;
 }
 
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index bfc25f82a76d02..2a46eb68b40924 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -8233,7 +8233,7 @@ void ASTReader::InitializeSema(Sema &S) {
         FX = BD->getFunctionEffects();
       }
       if (FX) {
-        SemaObj->AllEffectsToVerify |= FX;
+        SemaObj->AllEffectsToVerify.insertMultiple(FX);
       }
     }
     DeclsWithEffectsToVerify.clear();

>From 45389bd879af7dd2ab008c0ddd3a2dc7f8d2467d Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Thu, 11 Apr 2024 11:37:23 -0700
Subject: [PATCH 27/40] - During parsing, don't remove nonallocating when
 nonblocking is added; keep both. - Fix hacky serialization of
 FunctionEffectSet. - Rename CheckAddCallableWithEffects ->
 MaybeAddDeclWithEffects. - Don't unique FunctionEffectSets in the AST any
 more (overkill). - FunctionEffect::Type -> Kind as per coding guidelines (and
 to disambiguate from Type)

---
 clang/include/clang/AST/ASTContext.h          |  22 --
 clang/include/clang/AST/AbstractBasicReader.h |   8 +
 clang/include/clang/AST/AbstractBasicWriter.h |   6 +
 clang/include/clang/AST/PropertiesBase.td     |   1 +
 clang/include/clang/AST/Type.h                | 185 +++++++-------
 clang/include/clang/AST/TypeProperties.td     |   6 +-
 clang/include/clang/Sema/Sema.h               |   4 +-
 clang/lib/AST/ASTContext.cpp                  |  75 ------
 clang/lib/AST/Type.cpp                        | 241 +++++++++---------
 clang/lib/Sema/AnalysisBasedWarnings.cpp      |  35 +--
 clang/lib/Sema/SemaDecl.cpp                   |   8 +-
 clang/lib/Sema/SemaDeclCXX.cpp                |   2 +-
 clang/lib/Sema/SemaExpr.cpp                   |   2 +-
 clang/lib/Sema/SemaLambda.cpp                 |   2 +-
 clang/lib/Sema/SemaType.cpp                   |  18 +-
 clang/lib/Serialization/ASTReader.cpp         |   2 +-
 clang/test/Sema/attr-nonblocking-syntax.cpp   |   2 +-
 17 files changed, 258 insertions(+), 361 deletions(-)

diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index de984ace425eb0..08f71051e6cbf3 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -69,8 +69,6 @@ class DiagnosticsEngine;
 class DynTypedNodeList;
 class Expr;
 enum class FloatModeKind;
-class FunctionEffect;
-class FunctionEffectSet;
 class GlobalDecl;
 class IdentifierTable;
 class LangOptions;
@@ -466,16 +464,6 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// This is the top-level (C++20) Named module we are building.
   Module *CurrentCXXNamedModule = nullptr;
 
-  class FunctionEffectSetUniquing {
-    llvm::DenseSet<llvm::ArrayRef<FunctionEffect>> Set;
-
-  public:
-    FunctionEffectSet getUniqued(llvm::ArrayRef<FunctionEffect> FX);
-
-    ~FunctionEffectSetUniquing();
-  };
-  FunctionEffectSetUniquing UniquedFunctionEffectSet;
-
   static constexpr unsigned ConstantArrayTypesLog2InitSize = 8;
   static constexpr unsigned GeneralTypesLog2InitSize = 9;
   static constexpr unsigned FunctionProtoTypesLog2InitSize = 12;
@@ -1082,16 +1070,6 @@ class ASTContext : public RefCountedBase<ASTContext> {
   /// Get module under construction, nullptr if this is not a C++20 module.
   Module *getCurrentNamedModule() const { return CurrentCXXNamedModule; }
 
-  /// Get or create a uniqued, immutable FunctionEffectSet.
-  FunctionEffectSet
-  getUniquedFunctionEffectSet(llvm::ArrayRef<FunctionEffect> FX) {
-    return UniquedFunctionEffectSet.getUniqued(FX);
-  }
-
-  /// Get or create a uniqued, immutable FunctionEffectSet from a serialized
-  /// span of uint32_t's.
-  FunctionEffectSet getUniquedFunctionEffectSet(llvm::ArrayRef<uint32_t> FX);
-
   TranslationUnitDecl *getTranslationUnitDecl() const {
     return TUDecl->getMostRecentDecl();
   }
diff --git a/clang/include/clang/AST/AbstractBasicReader.h b/clang/include/clang/AST/AbstractBasicReader.h
index 1f2797cc701458..be057d8c06584b 100644
--- a/clang/include/clang/AST/AbstractBasicReader.h
+++ b/clang/include/clang/AST/AbstractBasicReader.h
@@ -244,6 +244,14 @@ class DataStreamBasicReader : public BasicReaderBase<Impl> {
     return FunctionProtoType::ExtParameterInfo::getFromOpaqueValue(value);
   }
 
+  FunctionEffect readFunctionEffect() {
+    static_assert(sizeof(FunctionEffect().getAsOpaqueValue()) <=
+                      sizeof(uint32_t),
+                  "update this if size changes");
+    uint32_t value = asImpl().readUInt32();
+    return FunctionEffect::getFromOpaqueValue(value);
+  }
+
   NestedNameSpecifier *readNestedNameSpecifier() {
     auto &ctx = getASTContext();
 
diff --git a/clang/include/clang/AST/AbstractBasicWriter.h b/clang/include/clang/AST/AbstractBasicWriter.h
index 07afa388de2c17..9f32523c58bbb4 100644
--- a/clang/include/clang/AST/AbstractBasicWriter.h
+++ b/clang/include/clang/AST/AbstractBasicWriter.h
@@ -222,6 +222,12 @@ class DataStreamBasicWriter : public BasicWriterBase<Impl> {
     asImpl().writeUInt32(epi.getOpaqueValue());
   }
 
+  void writeFunctionEffect(FunctionEffect effect) {
+    static_assert(sizeof(effect.getAsOpaqueValue()) <= sizeof(uint32_t),
+                  "update this if the value size changes");
+    asImpl().writeUInt32(effect.getAsOpaqueValue());
+  }
+
   void writeNestedNameSpecifier(NestedNameSpecifier *NNS) {
     // Nested name specifiers usually aren't too long. I think that 8 would
     // typically accommodate the vast majority.
diff --git a/clang/include/clang/AST/PropertiesBase.td b/clang/include/clang/AST/PropertiesBase.td
index 6df1d93a7ba2eb..457d09c2f3cd9d 100644
--- a/clang/include/clang/AST/PropertiesBase.td
+++ b/clang/include/clang/AST/PropertiesBase.td
@@ -117,6 +117,7 @@ def ExtParameterInfo : PropertyType<"FunctionProtoType::ExtParameterInfo">;
 def FixedPointSemantics : PropertyType<"llvm::FixedPointSemantics"> {
   let PassByReference = 1;
 }
+def FunctionEffect : PropertyType<"FunctionEffect">;
 def Identifier : RefPropertyType<"IdentifierInfo"> { let ConstWhenWriting = 1; }
 def LValuePathEntry : PropertyType<"APValue::LValuePathEntry">;
 def LValuePathSerializationHelper :
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index e4f0c545f80b98..e9d80845da494c 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4438,22 +4438,19 @@ class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
 class Decl;
 class CXXMethodDecl;
 class FunctionEffectSet;
-class TypeSourceInfo;
 
-/// Represents an abstract function effect.
+/// Represents an abstract function effect, using just an enumeration describing
+/// its type. Encapsulates its semantic behaviors.
 class FunctionEffect {
 public:
-  /// Identifies the particular type of effect.
-  enum class Type {
-    None = 0,
+  /// Identifies the particular effect.
+  enum class Kind : uint8_t {
+    None,
     NonBlocking,
     NonAllocating,
   };
 
-  /// Flags describing behaviors of the effect.
-  // (Why not a struct with bitfields? There's one function that would like to
-  // test a caller-specified bit. There are some potential optimizations that
-  // would OR together the bits of multiple effects.)
+  /// Flags describing some behaviors of the effect.
   using Flags = unsigned;
   enum FlagBit : Flags {
     // Can verification inspect callees' implementations? (e.g. nonblocking:
@@ -4477,57 +4474,69 @@ class FunctionEffect {
   };
 
 private:
-  // For uniqueness, currently only EfType is significant.
+  Kind FKind;
 
-  LLVM_PREFERRED_TYPE(Type)
-  unsigned EfType : 2;
-  Flags EfFlags : 8; // A constant function of Type but cached here.
-
-  // Expansion: for hypothetical TCB+types, there could be one Type for TCB,
-  // then ~16(?) bits "Subtype" to map to a specific named TCB. Subtype would
+  // Expansion: for hypothetical TCB+types, there could be one Kind for TCB,
+  // then ~16(?) bits "SubKind" to map to a specific named TCB. SubKind would
   // be considered for uniqueness.
 
-  // Since this struct is serialized as if it were a uint32_t, it's important
-  // to pad and explicitly zero the extra bits.
-  [[maybe_unused]] unsigned Padding : 22;
-
 public:
-  FunctionEffect() : EfType(unsigned(Type::None)), EfFlags(0), Padding(0) {}
+  FunctionEffect() : FKind(Kind::None) {}
 
-  explicit FunctionEffect(Type T);
+  explicit FunctionEffect(Kind T) : FKind(T) {}
 
-  /// The type of the effect.
-  Type type() const { return Type(EfType); }
+  /// The kind of the effect.
+  Kind kind() const { return FKind; }
 
-  /// Flags describing behaviors of the effect.
-  Flags flags() const { return EfFlags; }
+  /// Return an opaque integer, as a serializable representation.
+  uint32_t getAsOpaqueValue() const { return llvm::to_underlying(FKind); }
+
+  /// Construct from a serialized representation.
+  static FunctionEffect getFromOpaqueValue(uint32_t V) {
+    return FunctionEffect(static_cast<Kind>(V));
+  }
+
+  /// Flags describing some behaviors of the effect.
+  Flags flags() const {
+    switch (FKind) {
+    case Kind::NonBlocking:
+      return FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
+             FE_ExcludeObjCMessageSend | FE_ExcludeStaticLocalVars |
+             FE_ExcludeThreadLocalVars;
+    case Kind::NonAllocating:
+      // Same as NonBlocking, except without FE_ExcludeStaticLocalVars
+      return FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
+             FE_ExcludeObjCMessageSend | FE_ExcludeThreadLocalVars;
+    case Kind::None:
+      break;
+    }
+    llvm_unreachable("unknown effect kind");
+  }
 
   /// The description printed in diagnostics, e.g. 'nonblocking'.
   StringRef name() const;
 
-  /// A hashable representation.
-  uint32_t opaqueRepr() const { return EfType | (EfFlags << 2u); }
-
   /// Return true if adding or removing the effect as part of a type conversion
   /// should generate a diagnostic.
   bool shouldDiagnoseConversion(bool Adding, QualType OldType,
-                                FunctionEffectSet OldFX, QualType NewType,
-                                FunctionEffectSet NewFX) const;
+                                const FunctionEffectSet &OldFX,
+                                QualType NewType,
+                                const FunctionEffectSet &NewFX) const;
 
   /// Return true if adding or removing the effect in a redeclaration should
   /// generate a diagnostic.
   bool shouldDiagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
-                                   FunctionEffectSet OldFX,
+                                   const FunctionEffectSet &OldFX,
                                    const FunctionDecl &NewFunction,
-                                   FunctionEffectSet NewFX) const;
+                                   const FunctionEffectSet &NewFX) const;
 
   /// Return true if adding or removing the effect in a C++ virtual method
   /// override should generate a diagnostic.
-  OverrideResult shouldDiagnoseMethodOverride(bool Adding,
-                                              const CXXMethodDecl &OldMethod,
-                                              FunctionEffectSet OldFX,
-                                              const CXXMethodDecl &NewMethod,
-                                              FunctionEffectSet NewFX) const;
+  OverrideResult
+  shouldDiagnoseMethodOverride(bool Adding, const CXXMethodDecl &OldMethod,
+                               const FunctionEffectSet &OldFX,
+                               const CXXMethodDecl &NewMethod,
+                               const FunctionEffectSet &NewFX) const;
 
   /// Return true if the effect is allowed to be inferred on the callee,
   /// which is either a FunctionDecl or BlockDecl.
@@ -4541,99 +4550,91 @@ class FunctionEffect {
   // diagnostic. Caller should be assumed to have the effect (it may not have it
   // explicitly when inferring).
   bool shouldDiagnoseFunctionCall(bool Direct,
-                                  FunctionEffectSet CalleeFX) const;
+                                  const FunctionEffectSet &CalleeFX) const;
 
   friend bool operator==(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.EfType == RHS.EfType;
+    return LHS.FKind == RHS.FKind;
   }
   friend bool operator!=(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.EfType != RHS.EfType;
+    return LHS.FKind != RHS.FKind;
   }
   friend bool operator<(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.EfType < RHS.EfType;
+    return LHS.FKind < RHS.FKind;
   }
 };
 
-// It is the user's responsibility to keep this in set form: elements are
-// ordered and unique.
-// We could hide the mutating methods which are capable of breaking the
-// invariant, but they're needed and safe when used with STL set algorithms.
-class MutableFunctionEffectSet : public SmallVector<FunctionEffect, 4> {
-public:
-  using SmallVector::insert;
-  using SmallVector::SmallVector;
-
-  MutableFunctionEffectSet(const FunctionEffect &Effect);
-  using Base = SmallVector<FunctionEffect, 4>;
-
-  /// Maintains order/uniquenesss.
-  void insert(const FunctionEffect &Effect);
-
-  MutableFunctionEffectSet &insertMultiple(FunctionEffectSet RHS);
-
-  operator llvm::ArrayRef<FunctionEffect>() const { return {data(), size()}; }
-};
-
-/// A constant, uniqued set of FunctionEffect instances.
-// These sets will tend to be very small (0-1 elements), so represent them as
-// sorted spans, which are compatible with the STL set algorithms.
+/// A value type, representing a set of FunctionEffects. To reduce superfluous
+/// retain/release, however, prefer to pass by reference.
 class FunctionEffectSet {
 private:
-  friend class ASTContext; // so it can call the private constructor
+  // Implementation is as a SmallVector, kept sorted.
+  // With a SmallVector size of 4, footprint is 32 bytes (on arm64).
+  // Use indirection through a possibly null reference-counted pointer to
+  // optimize the overwhelmingly common case of an empty set, and to
+  // minimize memory footprint.
+  struct ImplVec : public SmallVector<FunctionEffect, 4>,
+                   public RefCountedBase<ImplVec> {};
+  using ImplPtr = IntrusiveRefCntPtr<ImplVec>;
 
-  explicit FunctionEffectSet(llvm::ArrayRef<FunctionEffect> Array)
-      : Impl(Array) {}
+  ImplPtr PImpl;
 
-  // Points to a separately allocated array, uniqued.
-  llvm::ArrayRef<FunctionEffect> Impl;
+  explicit FunctionEffectSet(ImplPtr &&Ptr) : PImpl(std::move(Ptr)) {}
+  ImplVec &mutableVec();
 
 public:
   using Differences = SmallVector<std::pair<FunctionEffect, /*added=*/bool>>;
 
   FunctionEffectSet() = default;
 
-  const void *getOpaqueValue() const { return Impl.data(); }
-  llvm::ArrayRef<uint32_t> serializable() const {
-    static_assert(sizeof(FunctionEffect) == sizeof(uint32_t));
-    const uint32_t *ptr = reinterpret_cast<const uint32_t *>(Impl.data());
-    return {const_cast<uint32_t *>(ptr), Impl.size()};
-  }
+  void Profile(llvm::FoldingSetNodeID &ID) const;
+
+  FunctionEffectSet &operator=(const llvm::ArrayRef<FunctionEffect> arr);
 
   explicit operator bool() const { return !empty(); }
-  bool empty() const { return Impl.empty(); }
-  size_t size() const { return Impl.size(); }
+  bool empty() const { return PImpl == nullptr || PImpl->empty(); }
+  size_t size() const { return PImpl ? PImpl->size() : 0; }
 
   using iterator = const FunctionEffect *;
 
-  iterator begin() const { return Impl.begin(); }
+  iterator begin() const { return PImpl ? PImpl->begin() : nullptr; }
 
-  iterator end() const { return Impl.end(); }
+  iterator end() const { return PImpl ? PImpl->end() : nullptr; }
 
-  ArrayRef<FunctionEffect> items() const { return Impl; }
+  ArrayRef<FunctionEffect> items() const {
+    if (PImpl)
+      return *PImpl;
+    return {};
+  }
 
   bool operator==(const FunctionEffectSet &RHS) const {
-    return Impl.data() == RHS.Impl.data();
+    const FunctionEffectSet &LHS = *this;
+    if (LHS.PImpl == nullptr)
+      return RHS.PImpl == nullptr;
+    if (RHS.PImpl == nullptr)
+      return false;
+    return LHS.PImpl == RHS.PImpl || *LHS.PImpl == *RHS.PImpl;
   }
   bool operator!=(const FunctionEffectSet &RHS) const {
-    return Impl.data() != RHS.Impl.data();
+    return !(*this == RHS);
   }
-  bool operator<(const FunctionEffectSet &RHS) const;
 
   void dump(llvm::raw_ostream &OS) const;
 
-  MutableFunctionEffectSet intersection(const FunctionEffectSet &RHS) const;
-  MutableFunctionEffectSet difference(const FunctionEffectSet &RHS) const;
-
-  static FunctionEffectSet getUnion(ASTContext &C, const FunctionEffectSet &LHS,
-                                    const FunctionEffectSet &RHS);
+  FunctionEffectSet getIntersection(const FunctionEffectSet &RHS) const;
+  FunctionEffectSet getDifference(const FunctionEffectSet &RHS) const;
+  FunctionEffectSet getUnion(const FunctionEffectSet &RHS) const;
 
   /// Caller should short-circuit by checking for equality first.
   static Differences differences(const FunctionEffectSet &Old,
                                  const FunctionEffectSet &New);
 
-  /// Extract the effects from a Type if it is a function, block, member
-  /// function pointer, reference or pointer to one.
+  /// Extract the effects from a Type if it is a function, block, or member
+  /// function pointer, or a reference or pointer to one.
   static FunctionEffectSet get(QualType QT);
+
+  // Mutators
+  void insert(const FunctionEffect &Effect);
+  void insert(const FunctionEffectSet &Set);
 };
 
 /// Represents a prototype with parameter type info, e.g.
@@ -4810,7 +4811,7 @@ class FunctionProtoType final
   }
 
   unsigned numTrailingObjects(OverloadToken<FunctionEffectSet>) const {
-    return hasFunctionEffects();
+    return hasFunctionEffects() ? 1 : 0;
   }
 
   /// Determine whether there are any argument types that
diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
index 538523f4447578..8ad6a13b3bffe3 100644
--- a/clang/include/clang/AST/TypeProperties.td
+++ b/clang/include/clang/AST/TypeProperties.td
@@ -352,8 +352,8 @@ let Class = FunctionProtoType in {
   def : Property<"AArch64SMEAttributes", UInt32> {
     let Read = [{ node->getAArch64SMEAttributes() }];
   }
-  def : Property<"functionEffects", Array<UInt32>> {
-    let Read = [{ node->getFunctionEffects().serializable() }];
+  def : Property<"functionEffects", Array<FunctionEffect>> {
+    let Read = [{ node->getFunctionEffects().items() }];
   }
 
   def : Creator<[{
@@ -371,7 +371,7 @@ let Class = FunctionProtoType in {
     epi.ExtParameterInfos =
       extParameterInfo.empty() ? nullptr : extParameterInfo.data();
     epi.AArch64SMEAttributes = AArch64SMEAttributes;
-    epi.FunctionEffects = ctx.getUniquedFunctionEffectSet(functionEffects);
+    epi.FunctionEffects = functionEffects;
     return ctx.getFunctionType(returnType, parameters, epi);
   }]>;
 }
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 872947afbcf417..3aa86b2a79ebc9 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -723,7 +723,7 @@ class Sema final {
   /// FunctionEffectSet to be verified.
   SmallVector<const Decl *> DeclsWithEffectsToVerify;
   /// The union of all effects present on DeclsWithEffectsToVerify.
-  MutableFunctionEffectSet AllEffectsToVerify;
+  FunctionEffectSet AllEffectsToVerify;
 
   /// Determine if VD, which must be a variable or function, is an external
   /// symbol that nonetheless can't be referenced from outside this translation
@@ -3155,7 +3155,7 @@ class Sema final {
                               StorageClass SC);
 
   /// Potentially add a FunctionDecl or BlockDecl to DeclsWithEffectsToVerify.
-  void CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX);
+  void MaybeAddDeclWithEffects(const Decl *D, const FunctionEffectSet &FX);
 
   // Contexts where using non-trivial C union types can be disallowed. This is
   // passed to err_non_trivial_c_union_in_invalid_context.
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 26523c1ab370c8..ee0550107d71e4 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -13807,78 +13807,3 @@ StringRef ASTContext::getCUIDHash() const {
   CUIDHash = llvm::utohexstr(llvm::MD5Hash(LangOpts.CUID), /*LowerCase=*/true);
   return CUIDHash;
 }
-
-using FunctionEffectSpan = llvm::ArrayRef<FunctionEffect>;
-
-llvm::hash_code hash_value(const FunctionEffect &Effect) {
-  return llvm::hash_value(Effect.opaqueRepr());
-}
-
-namespace llvm {
-template <> struct DenseMapInfo<FunctionEffectSpan> {
-  static FunctionEffectSpan getEmptyKey() {
-    return {static_cast<const FunctionEffect *>(nullptr), size_t(0)};
-  }
-  static FunctionEffectSpan getTombstoneKey() {
-    return {reinterpret_cast<const FunctionEffect *>(intptr_t(-1)), size_t(0)};
-  }
-  static unsigned getHashValue(const FunctionEffectSpan &Val) {
-    hash_code hash1 = hash_value(Val.size());
-    // Treat the FunctionEffects as a span of integers
-    const FunctionEffect *Begin = Val.begin();
-    const FunctionEffect *End = Val.end();
-    hash_code hash2 =
-        hash_combine_range(reinterpret_cast<const uint32_t *>(Begin),
-                           reinterpret_cast<const uint32_t *>(End));
-    return hash_combine(hash1, hash2);
-  }
-  static bool isEqual(const FunctionEffectSpan &LHS,
-                      const FunctionEffectSpan &RHS) {
-    if (LHS.size() != RHS.size()) {
-      return false;
-    }
-    // distinguish empty from tombstone
-    if (LHS.size() == 0) {
-      return LHS.data() == RHS.data();
-    }
-    return std::equal(LHS.begin(), LHS.end(), RHS.begin());
-  }
-};
-} // namespace llvm
-
-FunctionEffectSet
-ASTContext::getUniquedFunctionEffectSet(llvm::ArrayRef<uint32_t> FX) {
-  static_assert(sizeof(FunctionEffect) == sizeof(uint32_t));
-  const auto *ptr = reinterpret_cast<const FunctionEffect *>(FX.data());
-  return UniquedFunctionEffectSet.getUniqued({ptr, FX.size()});
-}
-
-FunctionEffectSet ASTContext::FunctionEffectSetUniquing::getUniqued(
-    llvm::ArrayRef<FunctionEffect> FX) {
-  if (FX.empty()) {
-    return {};
-  }
-
-  // Do we already have the incoming set?
-  const auto Iter = Set.find_as(FX);
-  if (Iter != Set.end()) {
-    return FunctionEffectSet(*Iter);
-  }
-
-  // Copy the incoming array to permanent storage.
-  FunctionEffect *Storage = new FunctionEffect[FX.size()];
-  std::copy(FX.begin(), FX.end(), Storage);
-
-  // Make a new wrapper and insert it into the set.
-  llvm::ArrayRef<FunctionEffect> Arr(Storage, FX.size());
-  auto [InsIter, _] = Set.insert(Arr);
-  return FunctionEffectSet(*InsIter);
-}
-
-ASTContext::FunctionEffectSetUniquing::~FunctionEffectSetUniquing() {
-  for (const auto &ArrRef : Set) {
-    const FunctionEffect *ptrToFX = ArrRef.data();
-    delete[] ptrToFX;
-  }
-  Set.clear();
-}
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 5d22d058070ab6..a9328b1c0d366c 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3642,7 +3642,9 @@ FunctionProtoType::FunctionProtoType(QualType result, ArrayRef<QualType> params,
     auto &ExtraBits = *getTrailingObjects<FunctionTypeExtraBitfields>();
     ExtraBits.HasFunctionEffects = true;
 
-    *getTrailingObjects<FunctionEffectSet>() = epi.FunctionEffects;
+    // N.B. This is uninitialized storage.
+    FunctionEffectSet *PFX = getTrailingObjects<FunctionEffectSet>();
+    new (PFX) FunctionEffectSet(epi.FunctionEffects);
   }
 }
 
@@ -3732,7 +3734,7 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   // spec because of the leading 'bool' which unambiguously indicates
   // whether the following bool is the EH spec or part of the arguments.
 
-  ID.AddPointer(epi.FunctionEffects.getOpaqueValue());
+  epi.FunctionEffects.Profile(ID);
   ID.AddPointer(Result.getAsOpaquePtr());
   for (unsigned i = 0; i != NumParams; ++i)
     ID.AddPointer(ArgTys[i].getAsOpaquePtr());
@@ -5025,97 +5027,77 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
           getTypeConstraintConcept(), getTypeConstraintArguments());
 }
 
-FunctionEffect::FunctionEffect(Type T)
-    : EfType(static_cast<unsigned>(T)), EfFlags(0), Padding(0) {
-  switch (T) {
-  case Type::NonBlocking:
-    EfFlags = FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
-              FE_ExcludeObjCMessageSend | FE_ExcludeStaticLocalVars |
-              FE_ExcludeThreadLocalVars;
-    break;
-
-  case Type::NonAllocating:
-    // Same as NonBlocking, except without FE_ExcludeStaticLocalVars
-    EfFlags = FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
-              FE_ExcludeObjCMessageSend | FE_ExcludeThreadLocalVars;
-    break;
-  case Type::None:
-    break;
-  }
-  llvm_unreachable("unknown effect type");
-}
-
 StringRef FunctionEffect::name() const {
-  switch (type()) {
-  case Type::NonBlocking:
+  switch (kind()) {
+  case Kind::NonBlocking:
     return "nonblocking";
-  case Type::NonAllocating:
+  case Kind::NonAllocating:
     return "nonallocating";
-  case Type::None:
+  case Kind::None:
     break;
   }
-  llvm_unreachable("unknown effect type");
+  llvm_unreachable("unknown effect kind");
 }
 
-bool FunctionEffect::shouldDiagnoseConversion(bool Adding, QualType OldType,
-                                              FunctionEffectSet OldFX,
-                                              QualType NewType,
-                                              FunctionEffectSet NewFX) const {
+bool FunctionEffect::shouldDiagnoseConversion(
+    bool Adding, QualType OldType, const FunctionEffectSet &OldFX,
+    QualType NewType, const FunctionEffectSet &NewFX) const {
 
-  switch (type()) {
-  case Type::NonAllocating:
+  switch (kind()) {
+  case Kind::NonAllocating:
     // nonallocating can't be added (spoofed) during a conversion, unless we
     // have nonblocking
     if (Adding) {
       for (const auto &Effect : OldFX) {
-        if (Effect.type() == Type::NonBlocking)
+        if (Effect.kind() == Kind::NonBlocking)
           return false;
       }
     }
     [[fallthrough]];
-  case Type::NonBlocking:
+  case Kind::NonBlocking:
     // nonblocking can't be added (spoofed) during a conversion
     return Adding;
-  case Type::None:
+  case Kind::None:
     break;
   }
-  llvm_unreachable("unknown effect type");
+  llvm_unreachable("unknown effect kind");
 }
 
 bool FunctionEffect::shouldDiagnoseRedeclaration(
-    bool Adding, const FunctionDecl &OldFunction, FunctionEffectSet OldFX,
-    const FunctionDecl &NewFunction, FunctionEffectSet NewFX) const {
-  switch (type()) {
-  case Type::NonAllocating:
-  case Type::NonBlocking:
+    bool Adding, const FunctionDecl &OldFunction,
+    const FunctionEffectSet &OldFX, const FunctionDecl &NewFunction,
+    const FunctionEffectSet &NewFX) const {
+  switch (kind()) {
+  case Kind::NonAllocating:
+  case Kind::NonBlocking:
     // nonblocking/nonallocating can't be removed in a redeclaration
     // adding -> false, removing -> true (diagnose)
     return !Adding;
-  case Type::None:
+  case Kind::None:
     break;
   }
-  llvm_unreachable("unknown effect type");
+  llvm_unreachable("unknown effect kind");
 }
 
 FunctionEffect::OverrideResult FunctionEffect::shouldDiagnoseMethodOverride(
-    bool Adding, const CXXMethodDecl &OldMethod, FunctionEffectSet OldFX,
-    const CXXMethodDecl &NewMethod, FunctionEffectSet NewFX) const {
-  switch (type()) {
-  case Type::NonAllocating:
-  case Type::NonBlocking:
+    bool Adding, const CXXMethodDecl &OldMethod, const FunctionEffectSet &OldFX,
+    const CXXMethodDecl &NewMethod, const FunctionEffectSet &NewFX) const {
+  switch (kind()) {
+  case Kind::NonAllocating:
+  case Kind::NonBlocking:
     // if added on an override, that's fine and not diagnosed.
     // if missing from an override (removed), propagate from base to derived.
     return Adding ? OverrideResult::Ignore : OverrideResult::Merge;
-  case Type::None:
+  case Kind::None:
     break;
   }
-  llvm_unreachable("unknown effect type");
+  llvm_unreachable("unknown effect kind");
 }
 
 bool FunctionEffect::canInferOnFunction(const Decl &Callee) const {
-  switch (type()) {
-  case Type::NonAllocating:
-  case Type::NonBlocking:
+  switch (kind()) {
+  case Kind::NonAllocating:
+  case Kind::NonBlocking:
     // Do any of the callee's Decls have type sugar for blocking or allocating?
     for (const Decl *D : Callee.redecls()) {
       QualType QT;
@@ -5134,96 +5116,115 @@ bool FunctionEffect::canInferOnFunction(const Decl &Callee) const {
       while (AT) {
         if (AT->getAttrKind() == attr::Allocating)
           return false;
-        if (type() == Type::NonBlocking && AT->getAttrKind() == attr::Blocking)
+        if (kind() == Kind::NonBlocking && AT->getAttrKind() == attr::Blocking)
           return false;
         AT = AT->getModifiedType()->getAs<AttributedType>();
       }
     }
     return true;
-  case Type::None:
+  case Kind::None:
     break;
   }
-  llvm_unreachable("unknown effect type");
+  llvm_unreachable("unknown effect kind");
 }
 
 bool FunctionEffect::shouldDiagnoseFunctionCall(
-    bool Direct, FunctionEffectSet CalleeFX) const {
-  switch (type()) {
-  case Type::NonAllocating:
-  case Type::NonBlocking: {
-    const Type CallerType = type();
+    bool Direct, const FunctionEffectSet &CalleeFX) const {
+  switch (kind()) {
+  case Kind::NonAllocating:
+  case Kind::NonBlocking: {
+    const Kind CallerKind = kind();
     for (const auto &Effect : CalleeFX) {
-      const Type ET = Effect.type();
+      const Kind EK = Effect.kind();
       // Does callee have same or stronger constraint?
-      if (ET == CallerType ||
-          (CallerType == Type::NonAllocating && ET == Type::NonBlocking)) {
+      if (EK == CallerKind ||
+          (CallerKind == Kind::NonAllocating && EK == Kind::NonBlocking)) {
         return false; // no diagnostic
       }
     }
     return true; // warning
   }
-  case Type::None:
+  case Kind::None:
     break;
   }
-  llvm_unreachable("unknown effect type");
+  llvm_unreachable("unknown effect kind");
 }
 
 // =====
 
-MutableFunctionEffectSet::MutableFunctionEffectSet(
-    const FunctionEffect &effect) {
-  push_back(effect);
+void FunctionEffectSet::Profile(llvm::FoldingSetNodeID &ID) const {
+  if (PImpl)
+    for (const auto &Effect : *PImpl)
+      ID.AddInteger(llvm::to_underlying(Effect.kind()));
 }
 
-void MutableFunctionEffectSet::insert(const FunctionEffect &Effect) {
-  const auto &Iter = std::lower_bound(begin(), end(), Effect);
-  if (Iter == end() || *Iter != Effect) {
-    insert(Iter, Effect);
-  }
-}
-
-MutableFunctionEffectSet &
-MutableFunctionEffectSet::insertMultiple(FunctionEffectSet RHS) {
-  // TODO: For large RHS sets, use set_union or a custom insert-in-place
-  for (const auto &Effect : RHS) {
-    insert(Effect);
+FunctionEffectSet &
+FunctionEffectSet::operator=(llvm::ArrayRef<FunctionEffect> Arr) {
+  if (Arr.empty()) {
+    PImpl.reset();
+  } else {
+    if (PImpl == nullptr)
+      PImpl = new ImplVec;
+    PImpl->assign(Arr.begin(), Arr.end());
   }
   return *this;
 }
 
-FunctionEffectSet FunctionEffectSet::getUnion(ASTContext &C,
-                                              const FunctionEffectSet &LHS,
-                                              const FunctionEffectSet &RHS) {
-  // Optimize for one of the two sets being empty
+FunctionEffectSet
+FunctionEffectSet::getUnion(const FunctionEffectSet &RHS) const {
+  const FunctionEffectSet &LHS = *this;
+  // Optimize for either of the two sets being empty (very common).
   if (LHS.empty())
     return RHS;
   if (RHS.empty())
     return LHS;
 
-  // Optimize the case where the two sets are identical
+  // Optimize for the two sets being identical (very common).
   if (LHS == RHS)
     return LHS;
 
-  MutableFunctionEffectSet Vec;
-  Vec.reserve(LHS.size() + RHS.size());
+  ImplPtr PVec(new ImplVec);
+  PVec->reserve(LHS.size() + RHS.size());
   std::set_union(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
-                 std::back_inserter(Vec));
-  // The result of a set operation is an ordered/unique set.
-  return C.getUniquedFunctionEffectSet(Vec);
+                 std::back_inserter(*PVec));
+  return FunctionEffectSet(std::move(PVec));
 }
 
-MutableFunctionEffectSet
-FunctionEffectSet::intersection(const FunctionEffectSet &RHS) const {
+FunctionEffectSet
+FunctionEffectSet::getIntersection(const FunctionEffectSet &RHS) const {
   const FunctionEffectSet &LHS = *this;
   if (LHS.empty() || RHS.empty()) {
     return {};
   }
 
-  MutableFunctionEffectSet Vec;
+  ImplPtr PVec(new ImplVec);
   std::set_intersection(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
-                        std::back_inserter(Vec));
-  // The result of a set operation is an ordered/unique set.
-  return Vec;
+                        std::back_inserter(*PVec));
+  return FunctionEffectSet(std::move(PVec));
+}
+
+FunctionEffectSet::Differences
+FunctionEffectSet::differences(const FunctionEffectSet &Old,
+                               const FunctionEffectSet &New) {
+  // TODO: Could be a one-pass algorithm.
+  Differences Result;
+  for (const auto &Effect : New.getDifference(Old)) {
+    Result.emplace_back(Effect, true);
+  }
+  for (const auto &Effect : Old.getDifference(New)) {
+    Result.emplace_back(Effect, false);
+  }
+  return Result;
+}
+
+FunctionEffectSet
+FunctionEffectSet::getDifference(const FunctionEffectSet &RHS) const {
+  const FunctionEffectSet &LHS = *this;
+  ImplPtr PVec(new ImplVec);
+
+  std::set_difference(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
+                      std::back_inserter(*PVec));
+  return FunctionEffectSet(std::move(PVec));
 }
 
 // TODO: inline?
@@ -5233,6 +5234,7 @@ FunctionEffectSet FunctionEffectSet::get(QualType QT) {
   if (QT->isPointerType())
     QT = QT->getPointeeType();
 
+  // TODO: Why aren't these included in isPointerType()?
   if (const auto *BT = QT->getAs<BlockPointerType>()) {
     QT = BT->getPointeeType();
   } else if (const auto *MP = QT->getAs<MemberPointerType>()) {
@@ -5247,34 +5249,29 @@ FunctionEffectSet FunctionEffectSet::get(QualType QT) {
   return {};
 }
 
-FunctionEffectSet::Differences
-FunctionEffectSet::differences(const FunctionEffectSet &Old,
-                               const FunctionEffectSet &New) {
-  // TODO: Could be a one-pass algorithm.
-  Differences Result;
-  for (const auto &Effect : New.difference(Old)) {
-    Result.emplace_back(Effect, true);
-  }
-  for (const auto &Effect : Old.difference(New)) {
-    Result.emplace_back(Effect, false);
-  }
-  return Result;
+// For use in mutating methods: only allow mutating the vector in
+// place when we hold the only reference. Otherwise, copy it first.
+FunctionEffectSet::ImplVec &FunctionEffectSet::mutableVec() {
+  if (PImpl->UseCount() > 1)
+    PImpl = new ImplVec(*PImpl);
+  assert(PImpl->UseCount() == 1 && "mutating a shared function effect set");
+  return *PImpl;
 }
 
-MutableFunctionEffectSet
-FunctionEffectSet::difference(const FunctionEffectSet &RHS) const {
-  const FunctionEffectSet &LHS = *this;
-  MutableFunctionEffectSet Result;
-
-  std::set_difference(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
-                      std::back_inserter(Result));
-  return Result;
+void FunctionEffectSet::insert(const FunctionEffect &Effect) {
+  if (PImpl == nullptr)
+    PImpl = new ImplVec;
+  auto *Iter = std::lower_bound(PImpl->begin(), PImpl->end(), Effect);
+  if (Iter == PImpl->end() || *Iter != Effect) {
+    mutableVec().insert(Iter, Effect);
+  }
 }
 
-bool FunctionEffectSet::operator<(const FunctionEffectSet &RHS) const {
-  const FunctionEffectSet &LHS = *this;
-  return std::lexicographical_compare(LHS.begin(), LHS.end(), RHS.begin(),
-                                      RHS.end());
+void FunctionEffectSet::insert(const FunctionEffectSet &Set) {
+  // TODO: For large RHS sets, use set_union or a custom insert-in-place
+  for (const auto &Effect : Set) {
+    insert(Effect);
+  }
 }
 
 LLVM_DUMP_METHOD void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 008d1798f36282..947f5ff98f74d6 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2613,13 +2613,13 @@ class PendingFunctionAnalysis {
   std::unique_ptr<SmallVector<DirectCall>> UnverifiedDirectCalls;
 
 public:
-  PendingFunctionAnalysis(Sema &Sem, const CallableInfo &CInfo,
-                          FunctionEffectSet AllInferrableEffectsToVerify) {
-    ASTContext &Ctx = Sem.getASTContext();
+  PendingFunctionAnalysis(
+      Sema &Sem, const CallableInfo &CInfo,
+      const FunctionEffectSet &AllInferrableEffectsToVerify) {
     DeclaredVerifiableEffects = CInfo.Effects;
 
     // Check for effects we are not allowed to infer
-    MutableFunctionEffectSet FX;
+    FunctionEffectSet FX;
 
     for (const auto &effect : AllInferrableEffectsToVerify) {
       if (effect.canInferOnFunction(*CInfo.CDecl)) {
@@ -2635,9 +2635,7 @@ class PendingFunctionAnalysis {
       }
     }
     // FX is now the set of inferrable effects which are not prohibited
-    FXToInfer = Ctx.getUniquedFunctionEffectSet(
-        Ctx.getUniquedFunctionEffectSet(FX).difference(
-            DeclaredVerifiableEffects));
+    FXToInfer = FX.getDifference(DeclaredVerifiableEffects);
   }
 
   // Hide the way that diagnostics for explicitly required effects vs. inferred
@@ -2718,17 +2716,16 @@ class CompleteFunctionAnalysis {
   EffectToDiagnosticMap InferrableEffectToFirstDiagnostic;
 
 public:
-  CompleteFunctionAnalysis(ASTContext &Ctx, PendingFunctionAnalysis &pending,
-                           FunctionEffectSet funcFX,
-                           FunctionEffectSet AllInferrableEffectsToVerify) {
-    MutableFunctionEffectSet verified;
-    verified.insertMultiple(funcFX);
+  CompleteFunctionAnalysis(
+      ASTContext &Ctx, PendingFunctionAnalysis &pending,
+      const FunctionEffectSet &funcFX,
+      const FunctionEffectSet &AllInferrableEffectsToVerify) {
+    VerifiedEffects.insert(funcFX);
     for (const auto &effect : AllInferrableEffectsToVerify) {
       if (pending.diagnosticForInferrableEffect(effect) == nullptr) {
-        verified.insert(effect);
+        VerifiedEffects.insert(effect);
       }
     }
-    VerifiedEffects = Ctx.getUniquedFunctionEffectSet(verified);
 
     InferrableEffectToFirstDiagnostic =
         std::move(pending.InferrableEffectToFirstDiagnostic);
@@ -2835,15 +2832,12 @@ class Analyzer {
     // Gather all of the effects to be verified to see what operations need to
     // be checked, and to see which ones are inferrable.
     {
-      MutableFunctionEffectSet inferrableEffects;
       for (const FunctionEffect &effect : Sem.AllEffectsToVerify) {
         const auto Flags = effect.flags();
         if (Flags & FunctionEffect::FE_InferrableOnCallees) {
-          inferrableEffects.insert(effect);
+          AllInferrableEffectsToVerify.insert(effect);
         }
       }
-      AllInferrableEffectsToVerify =
-          Sem.getASTContext().getUniquedFunctionEffectSet(inferrableEffects);
       if constexpr (DebugLogLevel > 0) {
         llvm::outs() << "AllInferrableEffectsToVerify: ";
         AllInferrableEffectsToVerify.dump(llvm::outs());
@@ -3016,8 +3010,7 @@ class Analyzer {
     if (DirectCall) {
       if (auto *CFA = DeclAnalysis.completedAnalysisForDecl(Callee.CDecl)) {
         // Combine declared effects with those which may have been inferred.
-        CalleeEffects = FunctionEffectSet::getUnion(
-            Sem.getASTContext(), CalleeEffects, CFA->VerifiedEffects);
+        CalleeEffects.insert(CFA->VerifiedEffects);
         IsInferencePossible = false; // we've already traversed it
       }
     }
@@ -3589,7 +3582,7 @@ class Analyzer {
       if (auto *Callable = Result.Nodes.getNodeAs<Decl>(Tag_Callable)) {
         if (const auto FX = functionEffectsForDecl(Callable)) {
           // Reuse this filtering method in Sema
-          Sem.CheckAddCallableWithEffects(Callable, FX);
+          Sem.MaybeAddDeclWithEffects(Callable, FX);
         }
       }
     }
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 2108ee75ddc670..3421709fd24aa8 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3940,7 +3940,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
     // declaration, but that would trigger an additional "conflicting types"
     // error.
     if (const auto *NewFPT = NewQType->getAs<FunctionProtoType>()) {
-      auto MergedFX = FunctionEffectSet::getUnion(Context, OldFX, NewFX);
+      auto MergedFX = OldFX.getUnion(NewFX);
 
       FunctionProtoType::ExtProtoInfo EPI = NewFPT->getExtProtoInfo();
       EPI.FunctionEffects = MergedFX;
@@ -11128,7 +11128,7 @@ Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
 
 // Should only be called when getFunctionEffects() returns a non-empty set.
 // Decl should be a FunctionDecl or BlockDecl.
-void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
+void Sema::MaybeAddDeclWithEffects(const Decl *D, const FunctionEffectSet &FX) {
   if (!D->hasBody()) {
     if (const auto *FD = D->getAsFunction()) {
       if (!FD->willHaveBody()) {
@@ -11152,7 +11152,7 @@ void Sema::CheckAddCallableWithEffects(const Decl *D, FunctionEffectSet FX) {
     return;
   }
 
-  AllEffectsToVerify.insertMultiple(FX);
+  AllEffectsToVerify.insert(FX);
 
   // Record the declaration for later analysis.
   DeclsWithEffectsToVerify.push_back(D);
@@ -16064,7 +16064,7 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
     Diag(FD->getLocation(), diag::warn_function_def_in_objc_container);
 
   if (const auto FX = FD->getCanonicalDecl()->getFunctionEffects()) {
-    CheckAddCallableWithEffects(FD, FX);
+    MaybeAddDeclWithEffects(FD, FX);
   }
 
   return D;
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 04ec7ee7ae7027..e87e34555cc80d 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18347,7 +18347,7 @@ bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
         AnyDiags = true;
         break;
       case FunctionEffect::OverrideResult::Merge: {
-        auto MergedFX = FunctionEffectSet::getUnion(Context, OldFX, NewFX);
+        auto MergedFX = OldFX.getUnion(NewFX);
 
         FunctionProtoType::ExtProtoInfo EPI = NewFT->getExtProtoInfo();
         EPI.FunctionEffects = MergedFX;
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 26a798675e3c70..2b4e1693cb1f1e 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -17157,7 +17157,7 @@ ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc,
   BlockDecl *BD = BSI->TheDecl;
 
   if (const auto FX = BD->getFunctionEffects()) {
-    CheckAddCallableWithEffects(BD, FX);
+    MaybeAddDeclWithEffects(BD, FX);
   }
 
   if (BSI->HasImplicitReturnType)
diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index 0e1a0f8dfdbabc..0772a2dec7b560 100644
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -1890,7 +1890,7 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body) {
   ActOnFinishFunctionBody(LSI.CallOperator, Body);
 
   if (const auto FX = LSI.CallOperator->getFunctionEffects()) {
-    CheckAddCallableWithEffects(LSI.CallOperator, FX);
+    MaybeAddDeclWithEffects(LSI.CallOperator, FX);
   }
 
   return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index d00752822bfcb9..08fce7ac781ce3 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8120,24 +8120,12 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
   // nonblocking(true) and nonallocating(true) are represented as
   // FunctionEffects, in a FunctionEffectSet attached to a FunctionProtoType.
   const FunctionEffect NewEffect(isNonBlocking
-                                     ? FunctionEffect::Type::NonBlocking
-                                     : FunctionEffect::Type::NonAllocating);
+                                     ? FunctionEffect::Kind::NonBlocking
+                                     : FunctionEffect::Kind::NonAllocating);
 
-  MutableFunctionEffectSet NewFX(NewEffect);
   FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
+  EPI.FunctionEffects.insert(NewEffect);
 
-  if (EPI.FunctionEffects) {
-    // Preserve any previous effects - except nonallocating, when we are adding
-    // nonblocking
-    for (const auto &Effect : EPI.FunctionEffects) {
-      if (!(isNonBlocking &&
-            Effect.type() == FunctionEffect::Type::NonAllocating))
-        NewFX.insert(Effect);
-    }
-  }
-
-  EPI.FunctionEffects =
-      TPState.getSema().getASTContext().getUniquedFunctionEffectSet(NewFX);
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
                                                FPT->getParamTypes(), EPI);
   QT = Unwrapped.wrap(S, newtype->getAs<FunctionType>());
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 2a46eb68b40924..2648f46b414226 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -8233,7 +8233,7 @@ void ASTReader::InitializeSema(Sema &S) {
         FX = BD->getFunctionEffects();
       }
       if (FX) {
-        SemaObj->AllEffectsToVerify.insertMultiple(FX);
+        SemaObj->AllEffectsToVerify.insert(FX);
       }
     }
     DeclsWithEffectsToVerify.clear();
diff --git a/clang/test/Sema/attr-nonblocking-syntax.cpp b/clang/test/Sema/attr-nonblocking-syntax.cpp
index 5a451f23f291fd..8fe3cfe529df49 100644
--- a/clang/test/Sema/attr-nonblocking-syntax.cpp
+++ b/clang/test/Sema/attr-nonblocking-syntax.cpp
@@ -45,7 +45,7 @@ void nl1() [[clang::nonblocking]] [[clang::nonallocating]];
 // CHECK: FunctionDecl {{.*}} nl1 'void () __attribute__((clang_nonblocking))'
 
 void nl2() [[clang::nonallocating]] [[clang::nonblocking]];
-// CHECK: FunctionDecl {{.*}} nl2 'void () __attribute__((clang_nonblocking))'
+// CHECK: FunctionDecl {{.*}} nl2 'void () __attribute__((clang_nonblocking)) __attribute__((clang_nonallocating))'
 
 decltype(nl1) nl3;
 // CHECK: FunctionDecl {{.*}} nl3 'decltype(nl1)':'void () __attribute__((clang_nonblocking))'

>From 80d5e7a03ccc34e7f95273b4597698391ba7ae33 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Thu, 11 Apr 2024 12:00:55 -0700
Subject: [PATCH 28/40] - Get rid of ugly const_cast in
 Sema::CheckOverridingFunctionAttributes. - Clarify comment in
 Sema::IsFunctionConversion.

---
 clang/include/clang/Sema/Sema.h | 2 +-
 clang/lib/Sema/SemaDeclCXX.cpp  | 9 ++-------
 clang/lib/Sema/SemaOverload.cpp | 8 ++++----
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 3aa86b2a79ebc9..33d9160d510206 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -4745,7 +4745,7 @@ class Sema final {
 
   std::string getAmbiguousPathsDisplayString(CXXBasePaths &Paths);
 
-  bool CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
+  bool CheckOverridingFunctionAttributes(CXXMethodDecl *New,
                                          const CXXMethodDecl *Old);
 
   /// CheckOverridingFunctionReturnType - Checks whether the return types are
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index e87e34555cc80d..95b8d4231b4014 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18288,7 +18288,7 @@ void Sema::SetFunctionBodyKind(Decl *D, SourceLocation Loc,
   }
 }
 
-bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
+bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
                                              const CXXMethodDecl *Old) {
   const auto *NewFT = New->getType()->castAs<FunctionProtoType>();
   const auto *OldFT = Old->getType()->castAs<FunctionProtoType>();
@@ -18353,12 +18353,7 @@ bool Sema::CheckOverridingFunctionAttributes(const CXXMethodDecl *New,
         EPI.FunctionEffects = MergedFX;
         QualType ModQT = Context.getFunctionType(NewFT->getReturnType(),
                                                  NewFT->getParamTypes(), EPI);
-
-        // TODO: It's ugly to be mutating the incoming const method. It is
-        // mutable in the calling function, though. There is also the
-        // possibility here that we are discarding some other sort of sugar on
-        // the method's type.
-        const_cast<CXXMethodDecl *>(New)->setType(ModQT);
+        New->setType(ModQT);
       } break;
       }
     }
diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 1396534949caf7..6dfe62417db792 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -1869,11 +1869,11 @@ bool Sema::IsFunctionConversion(QualType FromType, QualType ToType,
       Changed = true;
     }
 
+    // For C, when called from checkPointerTypesForAssignment,
+    // we need not to alter FromFn, or else even an innocuous cast
+    // like dropping effects will fail. In C++ however we do want to
+    // alter FromFn. TODO: Is this correct?
     if (getLangOpts().CPlusPlus) {
-      // For C, when called from checkPointerTypesForAssignment,
-      // we need not to change the type, or else even an innocuous cast
-      // like dropping effects will fail.
-      // TODO: Is this correct?
       FromFPT =
           dyn_cast<FunctionProtoType>(FromFn); // in case FromFn changed above
 

>From 9e223a398d943b019fe1431202c023b335148a7d Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Thu, 11 Apr 2024 12:07:13 -0700
Subject: [PATCH 29/40] Split out the Objective-C tests into a separate source
 file.

---
 ...ts.mm => attr-nonblocking-constraints.cpp} | 15 ------------
 .../attr-nonblocking-constraints.mm           | 23 +++++++++++++++++++
 2 files changed, 23 insertions(+), 15 deletions(-)
 rename clang/test/Sema/{attr-nonblocking-constraints.mm => attr-nonblocking-constraints.cpp} (91%)
 create mode 100644 clang/test/SemaObjCXX/attr-nonblocking-constraints.mm

diff --git a/clang/test/Sema/attr-nonblocking-constraints.mm b/clang/test/Sema/attr-nonblocking-constraints.cpp
similarity index 91%
rename from clang/test/Sema/attr-nonblocking-constraints.mm
rename to clang/test/Sema/attr-nonblocking-constraints.cpp
index e805a526a1bbd2..a273beac1baf73 100644
--- a/clang/test/Sema/attr-nonblocking-constraints.mm
+++ b/clang/test/Sema/attr-nonblocking-constraints.cpp
@@ -150,21 +150,6 @@ void nl12() {
 void nl12() [[clang::nonblocking]];
 void nl13() [[clang::nonblocking]] { nl12(); }
 
-// Objective-C
- at interface OCClass
-- (void)method;
- at end
-
-void nl14(OCClass *oc) [[clang::nonblocking]] {
-	[oc method]; // expected-warning {{'nonblocking' function must not access an ObjC method or property}}
-}
-void nl15(OCClass *oc) {
-	[oc method]; // expected-note {{function cannot be inferred 'nonblocking' because it accesses an ObjC method or property}}
-}
-void nl16(OCClass *oc) [[clang::nonblocking]] {
-	nl15(oc); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function 'nl15'}}
-}
-
 // C++ member function pointers
 struct PTMFTester {
 	typedef void (PTMFTester::*ConvertFunction)() [[clang::nonblocking]];
diff --git a/clang/test/SemaObjCXX/attr-nonblocking-constraints.mm b/clang/test/SemaObjCXX/attr-nonblocking-constraints.mm
new file mode 100644
index 00000000000000..aeb8b21f56e442
--- /dev/null
+++ b/clang/test/SemaObjCXX/attr-nonblocking-constraints.mm
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -fsyntax-only -fblocks -fcxx-exceptions -verify %s
+
+#if !__has_attribute(clang_nonblocking)
+#error "the 'nonblocking' attribute is not available"
+#endif
+
+#pragma clang diagnostic ignored "-Wperf-constraint-implies-noexcept"
+
+// Objective-C
+ at interface OCClass
+- (void)method;
+ at end
+
+void nl14(OCClass *oc) [[clang::nonblocking]] {
+	[oc method]; // expected-warning {{'nonblocking' function must not access an ObjC method or property}}
+}
+void nl15(OCClass *oc) {
+	[oc method]; // expected-note {{function cannot be inferred 'nonblocking' because it accesses an ObjC method or property}}
+}
+void nl16(OCClass *oc) [[clang::nonblocking]] {
+	nl15(oc); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function 'nl15'}}
+}
+

>From 9bac8d28ab5cb5d9d58125baea6c75695d622a98 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Thu, 11 Apr 2024 13:59:14 -0700
Subject: [PATCH 30/40] Make FunctionEffectSet::operator==() more elegant.

Tweak FunctionProtoType::Profile.
---
 clang/include/clang/AST/Type.h | 8 ++++----
 clang/lib/AST/Type.cpp         | 4 ++++
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index e9d80845da494c..2df18f4fac0021 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4608,11 +4608,11 @@ class FunctionEffectSet {
 
   bool operator==(const FunctionEffectSet &RHS) const {
     const FunctionEffectSet &LHS = *this;
-    if (LHS.PImpl == nullptr)
-      return RHS.PImpl == nullptr;
-    if (RHS.PImpl == nullptr)
+    if (LHS.PImpl == RHS.PImpl)
+      return true;
+    if (LHS.PImpl == nullptr || RHS.PImpl == nullptr)
       return false;
-    return LHS.PImpl == RHS.PImpl || *LHS.PImpl == *RHS.PImpl;
+    return *LHS.PImpl == *RHS.PImpl;
   }
   bool operator!=(const FunctionEffectSet &RHS) const {
     return !(*this == RHS);
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index a9328b1c0d366c..ae0d8e082492d4 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3734,7 +3734,10 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   // spec because of the leading 'bool' which unambiguously indicates
   // whether the following bool is the EH spec or part of the arguments.
 
+  // TODO: The effect set is variable-length, though prefaced with a size.
+  // Does this create potential ambiguity?
   epi.FunctionEffects.Profile(ID);
+
   ID.AddPointer(Result.getAsOpaquePtr());
   for (unsigned i = 0; i != NumParams; ++i)
     ID.AddPointer(ArgTys[i].getAsOpaquePtr());
@@ -5153,6 +5156,7 @@ bool FunctionEffect::shouldDiagnoseFunctionCall(
 // =====
 
 void FunctionEffectSet::Profile(llvm::FoldingSetNodeID &ID) const {
+  ID.AddInteger(size());
   if (PImpl)
     for (const auto &Effect : *PImpl)
       ID.AddInteger(llvm::to_underlying(Effect.kind()));

>From b955435ba4e2b0d449bf4035f19b2cb64a594b10 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Sat, 13 Apr 2024 16:05:49 -0700
Subject: [PATCH 31/40] Create a flat effect representation in
 FunctionProtoType. Renaming of multiple flavors of effect set.

---
 clang/include/clang/AST/AbstractBasicReader.h |   8 +-
 clang/include/clang/AST/AbstractBasicWriter.h |   7 +-
 clang/include/clang/AST/Decl.h                |   4 +-
 clang/include/clang/AST/PropertiesBase.td     |   2 +-
 clang/include/clang/AST/Type.h                | 215 +++++++++++-------
 clang/include/clang/AST/TypeProperties.td     |   6 +-
 clang/include/clang/Sema/Sema.h               |  25 +-
 clang/lib/AST/ASTContext.cpp                  |   4 +-
 clang/lib/AST/Decl.cpp                        |   4 +-
 clang/lib/AST/Type.cpp                        | 193 +++++++---------
 clang/lib/AST/TypePrinter.cpp                 |   9 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 171 ++++++++++++--
 clang/lib/Sema/Sema.cpp                       |   8 +-
 clang/lib/Sema/SemaDecl.cpp                   |  18 +-
 clang/lib/Sema/SemaDeclCXX.cpp                |   8 +-
 clang/lib/Sema/SemaExpr.cpp                   |   2 +-
 clang/lib/Sema/SemaLambda.cpp                 |   2 +-
 clang/lib/Sema/SemaType.cpp                   |  15 +-
 clang/lib/Serialization/ASTReader.cpp         |   4 +-
 clang/test/Sema/attr-nonblocking-syntax.cpp   |   6 +-
 20 files changed, 439 insertions(+), 272 deletions(-)

diff --git a/clang/include/clang/AST/AbstractBasicReader.h b/clang/include/clang/AST/AbstractBasicReader.h
index be057d8c06584b..7ab4cad4791618 100644
--- a/clang/include/clang/AST/AbstractBasicReader.h
+++ b/clang/include/clang/AST/AbstractBasicReader.h
@@ -244,12 +244,12 @@ class DataStreamBasicReader : public BasicReaderBase<Impl> {
     return FunctionProtoType::ExtParameterInfo::getFromOpaqueValue(value);
   }
 
-  FunctionEffect readFunctionEffect() {
-    static_assert(sizeof(FunctionEffect().getAsOpaqueValue()) <=
-                      sizeof(uint32_t),
+  CondFunctionEffect readCondFunctionEffect() {
+    static_assert(sizeof(FunctionEffect::Kind) <= sizeof(uint32_t),
                   "update this if size changes");
     uint32_t value = asImpl().readUInt32();
-    return FunctionEffect::getFromOpaqueValue(value);
+    Expr *cond = asImpl().readExprRef();
+    return CondFunctionEffect(static_cast<FunctionEffect::Kind>(value), cond);
   }
 
   NestedNameSpecifier *readNestedNameSpecifier() {
diff --git a/clang/include/clang/AST/AbstractBasicWriter.h b/clang/include/clang/AST/AbstractBasicWriter.h
index 9f32523c58bbb4..24d6d18d9e8b44 100644
--- a/clang/include/clang/AST/AbstractBasicWriter.h
+++ b/clang/include/clang/AST/AbstractBasicWriter.h
@@ -222,10 +222,11 @@ class DataStreamBasicWriter : public BasicWriterBase<Impl> {
     asImpl().writeUInt32(epi.getOpaqueValue());
   }
 
-  void writeFunctionEffect(FunctionEffect effect) {
-    static_assert(sizeof(effect.getAsOpaqueValue()) <= sizeof(uint32_t),
+  void writeCondFunctionEffect(const CondFunctionEffect &effect) {
+    static_assert(sizeof(FunctionEffect::Kind) <= sizeof(uint32_t),
                   "update this if the value size changes");
-    asImpl().writeUInt32(effect.getAsOpaqueValue());
+    asImpl().writeUInt32(llvm::to_underlying(effect.effect().kind()));
+    asImpl().writeExprRef(effect.condition());
   }
 
   void writeNestedNameSpecifier(NestedNameSpecifier *NNS) {
diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index acff3dee7051dc..0709223042ad45 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -3008,7 +3008,7 @@ class FunctionDecl : public DeclaratorDecl,
   /// computed and stored.
   unsigned getODRHash() const;
 
-  FunctionEffectSet getFunctionEffects() const;
+  FunctionTypeEffects getFunctionEffects() const;
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
@@ -4635,7 +4635,7 @@ class BlockDecl : public Decl, public DeclContext {
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
-  FunctionEffectSet getFunctionEffects() const;
+  FunctionTypeEffects getFunctionEffects() const;
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
diff --git a/clang/include/clang/AST/PropertiesBase.td b/clang/include/clang/AST/PropertiesBase.td
index 457d09c2f3cd9d..157d75ccdd584d 100644
--- a/clang/include/clang/AST/PropertiesBase.td
+++ b/clang/include/clang/AST/PropertiesBase.td
@@ -117,7 +117,7 @@ def ExtParameterInfo : PropertyType<"FunctionProtoType::ExtParameterInfo">;
 def FixedPointSemantics : PropertyType<"llvm::FixedPointSemantics"> {
   let PassByReference = 1;
 }
-def FunctionEffect : PropertyType<"FunctionEffect">;
+def CondFunctionEffect : PropertyType<"CondFunctionEffect">;
 def Identifier : RefPropertyType<"IdentifierInfo"> { let ConstWhenWriting = 1; }
 def LValuePathEntry : PropertyType<"APValue::LValuePathEntry">;
 def LValuePathSerializationHelper :
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 2df18f4fac0021..552aca902f658d 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4295,12 +4295,11 @@ class FunctionType : public Type {
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasArmTypeAttributes : 1;
 
-    LLVM_PREFERRED_TYPE(bool)
-    unsigned HasFunctionEffects : 1;
+    unsigned NumFunctionEffects : 4;
 
     FunctionTypeExtraBitfields()
         : NumExceptionType(0), HasArmTypeAttributes(false),
-          HasFunctionEffects(false) {}
+          NumFunctionEffects(0) {}
   };
 
   /// The AArch64 SME ACLE (Arm C/C++ Language Extensions) define a number
@@ -4437,10 +4436,11 @@ class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
 
 class Decl;
 class CXXMethodDecl;
-class FunctionEffectSet;
+class FunctionTypeEffects;
+class FunctionTypeEffectSet;
 
 /// Represents an abstract function effect, using just an enumeration describing
-/// its type. Encapsulates its semantic behaviors.
+/// its kind.
 class FunctionEffect {
 public:
   /// Identifies the particular effect.
@@ -4474,28 +4474,20 @@ class FunctionEffect {
   };
 
 private:
-  Kind FKind;
+  Kind FKind = Kind::None;
 
   // Expansion: for hypothetical TCB+types, there could be one Kind for TCB,
   // then ~16(?) bits "SubKind" to map to a specific named TCB. SubKind would
   // be considered for uniqueness.
 
 public:
-  FunctionEffect() : FKind(Kind::None) {}
+  FunctionEffect() = default;
 
-  explicit FunctionEffect(Kind T) : FKind(T) {}
+  explicit FunctionEffect(Kind K) : FKind(K) {}
 
   /// The kind of the effect.
   Kind kind() const { return FKind; }
 
-  /// Return an opaque integer, as a serializable representation.
-  uint32_t getAsOpaqueValue() const { return llvm::to_underlying(FKind); }
-
-  /// Construct from a serialized representation.
-  static FunctionEffect getFromOpaqueValue(uint32_t V) {
-    return FunctionEffect(static_cast<Kind>(V));
-  }
-
   /// Flags describing some behaviors of the effect.
   Flags flags() const {
     switch (FKind) {
@@ -4519,24 +4511,24 @@ class FunctionEffect {
   /// Return true if adding or removing the effect as part of a type conversion
   /// should generate a diagnostic.
   bool shouldDiagnoseConversion(bool Adding, QualType OldType,
-                                const FunctionEffectSet &OldFX,
+                                const FunctionTypeEffects &OldFX,
                                 QualType NewType,
-                                const FunctionEffectSet &NewFX) const;
+                                const FunctionTypeEffects &NewFX) const;
 
   /// Return true if adding or removing the effect in a redeclaration should
   /// generate a diagnostic.
   bool shouldDiagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
-                                   const FunctionEffectSet &OldFX,
+                                   const FunctionTypeEffects &OldFX,
                                    const FunctionDecl &NewFunction,
-                                   const FunctionEffectSet &NewFX) const;
+                                   const FunctionTypeEffects &NewFX) const;
 
   /// Return true if adding or removing the effect in a C++ virtual method
   /// override should generate a diagnostic.
   OverrideResult
   shouldDiagnoseMethodOverride(bool Adding, const CXXMethodDecl &OldMethod,
-                               const FunctionEffectSet &OldFX,
+                               const FunctionTypeEffects &OldFX,
                                const CXXMethodDecl &NewMethod,
-                               const FunctionEffectSet &NewFX) const;
+                               const FunctionTypeEffects &NewFX) const;
 
   /// Return true if the effect is allowed to be inferred on the callee,
   /// which is either a FunctionDecl or BlockDecl.
@@ -4550,91 +4542,134 @@ class FunctionEffect {
   // diagnostic. Caller should be assumed to have the effect (it may not have it
   // explicitly when inferring).
   bool shouldDiagnoseFunctionCall(bool Direct,
-                                  const FunctionEffectSet &CalleeFX) const;
+                                  ArrayRef<FunctionEffect> CalleeFX) const;
 
   friend bool operator==(const FunctionEffect &LHS, const FunctionEffect &RHS) {
     return LHS.FKind == RHS.FKind;
   }
   friend bool operator!=(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.FKind != RHS.FKind;
+    return !(LHS == RHS);
   }
   friend bool operator<(const FunctionEffect &LHS, const FunctionEffect &RHS) {
     return LHS.FKind < RHS.FKind;
   }
 };
 
-/// A value type, representing a set of FunctionEffects. To reduce superfluous
-/// retain/release, however, prefer to pass by reference.
-class FunctionEffectSet {
-private:
-  // Implementation is as a SmallVector, kept sorted.
-  // With a SmallVector size of 4, footprint is 32 bytes (on arm64).
-  // Use indirection through a possibly null reference-counted pointer to
-  // optimize the overwhelmingly common case of an empty set, and to
-  // minimize memory footprint.
-  struct ImplVec : public SmallVector<FunctionEffect, 4>,
-                   public RefCountedBase<ImplVec> {};
-  using ImplPtr = IntrusiveRefCntPtr<ImplVec>;
+/// A FunctionEffect plus a potential boolean expression determining whether
+/// the effect is declared (e.g. nonblocking(expr)). Generally the condition
+/// expression when present, is dependent.
+class CondFunctionEffect {
+  FunctionEffect Effect;
+  const Expr *Cond = nullptr; // if null, unconditional
 
-  ImplPtr PImpl;
+public:
+  CondFunctionEffect() = default;
+  CondFunctionEffect(FunctionEffect::Kind K, const Expr *Cond)
+      : Effect(K), Cond(Cond) {}
 
-  explicit FunctionEffectSet(ImplPtr &&Ptr) : PImpl(std::move(Ptr)) {}
-  ImplVec &mutableVec();
+  const FunctionEffect &effect() const { return Effect; }
+  const Expr *condition() const { return Cond; }
 
-public:
-  using Differences = SmallVector<std::pair<FunctionEffect, /*added=*/bool>>;
+private:
+  // Comparisons are tricky when the condition might be involved, so limit who
+  // might be doing them.
+  friend FunctionTypeEffects;
+  friend FunctionTypeEffectSet;
 
-  FunctionEffectSet() = default;
+  friend bool operator==(const CondFunctionEffect &LHS,
+                         const CondFunctionEffect &RHS) {
+    return LHS.Effect == RHS.Effect && LHS.Cond == RHS.Cond;
+  }
+  friend bool operator!=(const CondFunctionEffect &LHS,
+                         const CondFunctionEffect &RHS) {
+    return !(LHS == RHS);
+  }
+  friend bool operator<(const CondFunctionEffect &LHS,
+                        const CondFunctionEffect &RHS) {
+    return LHS.Effect < RHS.Effect;
+  }
+};
 
-  void Profile(llvm::FoldingSetNodeID &ID) const;
+// Container naming:
+// "type effects" are the ones which include a condition
+// FunctionTypeEffectsRef - holds pointers
+// FunctionTypeEffectSet - mutable
+// FunctionEffectSet - mutable, no condition
 
-  FunctionEffectSet &operator=(const llvm::ArrayRef<FunctionEffect> arr);
+/// An immutable set of CondFunctionEffect. The effects reside in memory not
+/// managed by this object (typically, trailing objects in FunctionProtoType).
+class FunctionTypeEffects {
+  ArrayRef<CondFunctionEffect> Items;
 
-  explicit operator bool() const { return !empty(); }
-  bool empty() const { return PImpl == nullptr || PImpl->empty(); }
-  size_t size() const { return PImpl ? PImpl->size() : 0; }
+public:
+  /// Extract the effects from a Type if it is a function, block, or member
+  /// function pointer, or a reference or pointer to one.
+  static FunctionTypeEffects get(QualType QT);
 
-  using iterator = const FunctionEffect *;
+  FunctionTypeEffects() = default;
 
-  iterator begin() const { return PImpl ? PImpl->begin() : nullptr; }
+  // The array is expected to have been sorted by the caller.
+  explicit FunctionTypeEffects(ArrayRef<CondFunctionEffect> Arr) : Items(Arr) {}
 
-  iterator end() const { return PImpl ? PImpl->end() : nullptr; }
+  operator bool() const { return !Items.empty(); }
+  size_t size() const { return Items.size(); }
+  operator ArrayRef<CondFunctionEffect>() const { return Items; }
 
-  ArrayRef<FunctionEffect> items() const {
-    if (PImpl)
-      return *PImpl;
-    return {};
-  }
+  using iterator = const CondFunctionEffect *;
+  iterator begin() const { return Items.begin(); }
+  iterator end() const { return Items.end(); }
 
-  bool operator==(const FunctionEffectSet &RHS) const {
-    const FunctionEffectSet &LHS = *this;
-    if (LHS.PImpl == RHS.PImpl)
-      return true;
-    if (LHS.PImpl == nullptr || RHS.PImpl == nullptr)
-      return false;
-    return *LHS.PImpl == *RHS.PImpl;
+  friend bool operator==(const FunctionTypeEffects &LHS,
+                         const FunctionTypeEffects &RHS) {
+    return LHS.Items == RHS.Items;
   }
-  bool operator!=(const FunctionEffectSet &RHS) const {
-    return !(*this == RHS);
+  friend bool operator!=(const FunctionTypeEffects &LHS,
+                         const FunctionTypeEffects &RHS) {
+    return !(LHS == RHS);
   }
 
+  void Profile(llvm::FoldingSetNodeID &ID) const;
   void dump(llvm::raw_ostream &OS) const;
+};
 
-  FunctionEffectSet getIntersection(const FunctionEffectSet &RHS) const;
-  FunctionEffectSet getDifference(const FunctionEffectSet &RHS) const;
-  FunctionEffectSet getUnion(const FunctionEffectSet &RHS) const;
+/// A mutable set of CondFunctionEffect.
+// Used transitorily within Sema to compare and merge effects on declarations.
+class FunctionTypeEffectSet {
+  SmallVector<CondFunctionEffect> Impl;
 
-  /// Caller should short-circuit by checking for equality first.
-  static Differences differences(const FunctionEffectSet &Old,
-                                 const FunctionEffectSet &New);
+public:
+  FunctionTypeEffectSet() = default;
+  explicit FunctionTypeEffectSet(ArrayRef<CondFunctionEffect> Arr)
+      : Impl(Arr.begin(), Arr.end()) {}
 
-  /// Extract the effects from a Type if it is a function, block, or member
-  /// function pointer, or a reference or pointer to one.
-  static FunctionEffectSet get(QualType QT);
+  explicit operator bool() const { return !Impl.empty(); }
+
+  // Implicit conversion to ArrayRef - careful with lifetime.
+  operator ArrayRef<CondFunctionEffect>() const { return Impl; }
+
+  using iterator = const CondFunctionEffect *;
+  iterator begin() const { return Impl.begin(); }
+  iterator end() const { return Impl.end(); }
+
+  void dump(llvm::raw_ostream &OS) const;
 
   // Mutators
-  void insert(const FunctionEffect &Effect);
-  void insert(const FunctionEffectSet &Set);
+  void insert(const CondFunctionEffect &Effect);
+  void insert(ArrayRef<CondFunctionEffect> Arr);
+  void insertIgnoringConditions(ArrayRef<CondFunctionEffect> Arr);
+
+  // Set operations, using ArrayRef to support FunctionTypeEffects
+
+  using Differences =
+      SmallVector<std::pair<CondFunctionEffect, /*added=*/bool>>;
+  /// Caller should short-circuit by checking for equality first.
+  static Differences differences(const FunctionTypeEffects &Old,
+                                 const FunctionTypeEffects &New);
+
+  static FunctionTypeEffectSet getUnion(ArrayRef<CondFunctionEffect> LHS,
+                                        ArrayRef<CondFunctionEffect> RHS);
+  static FunctionTypeEffectSet difference(ArrayRef<CondFunctionEffect> LHS,
+                                          ArrayRef<CondFunctionEffect> RHS);
 };
 
 /// Represents a prototype with parameter type info, e.g.
@@ -4652,7 +4687,7 @@ class FunctionProtoType final
           FunctionType::FunctionTypeExtraBitfields,
           FunctionType::FunctionTypeArmAttributes, FunctionType::ExceptionType,
           Expr *, FunctionDecl *, FunctionType::ExtParameterInfo,
-          FunctionEffectSet, Qualifiers> {
+          CondFunctionEffect, Qualifiers> {
   friend class ASTContext; // ASTContext creates these.
   friend TrailingObjects;
 
@@ -4683,8 +4718,7 @@ class FunctionProtoType final
   //   an ExtParameterInfo for each of the parameters. Present if and
   //   only if hasExtParameterInfos() is true.
   //
-  // * Optionally, a FunctionEffectSet. Present if and only if
-  //   hasFunctionEffects() is true.
+  // * Optionally, an array of getNumFunctionEffects() CondFunctionEffect.
   //
   // * Optionally a Qualifiers object to represent extra qualifiers that can't
   //   be represented by FunctionTypeBitfields.FastTypeQuals. Present if and
@@ -4744,7 +4778,7 @@ class FunctionProtoType final
     ExceptionSpecInfo ExceptionSpec;
     const ExtParameterInfo *ExtParameterInfos = nullptr;
     SourceLocation EllipsisLoc;
-    FunctionEffectSet FunctionEffects;
+    FunctionTypeEffects FunctionEffects;
 
     ExtProtoInfo()
         : Variadic(false), HasTrailingReturn(false),
@@ -4810,8 +4844,8 @@ class FunctionProtoType final
     return hasExtParameterInfos() ? getNumParams() : 0;
   }
 
-  unsigned numTrailingObjects(OverloadToken<FunctionEffectSet>) const {
-    return hasFunctionEffects() ? 1 : 0;
+  unsigned numTrailingObjects(OverloadToken<CondFunctionEffect>) const {
+    return getNumFunctionEffects();
   }
 
   /// Determine whether there are any argument types that
@@ -5127,15 +5161,20 @@ class FunctionProtoType final
     return false;
   }
 
-  bool hasFunctionEffects() const {
-    if (!hasExtraBitfields())
-      return false;
-    return getTrailingObjects<FunctionTypeExtraBitfields>()->HasFunctionEffects;
+  unsigned getNumFunctionEffects() const {
+    return hasExtraBitfields()
+               ? getTrailingObjects<FunctionTypeExtraBitfields>()
+                     ->NumFunctionEffects
+               : 0;
   }
 
-  FunctionEffectSet getFunctionEffects() const {
-    if (hasFunctionEffects())
-      return *getTrailingObjects<FunctionEffectSet>();
+  FunctionTypeEffects getFunctionEffects() const {
+    if (hasExtraBitfields()) {
+      const auto *Bitfields = getTrailingObjects<FunctionTypeExtraBitfields>();
+      if (Bitfields->NumFunctionEffects > 0)
+        return FunctionTypeEffects({getTrailingObjects<CondFunctionEffect>(),
+                                    Bitfields->NumFunctionEffects});
+    }
     return {};
   }
 
diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
index 8ad6a13b3bffe3..6d8cb8b1c2a6d0 100644
--- a/clang/include/clang/AST/TypeProperties.td
+++ b/clang/include/clang/AST/TypeProperties.td
@@ -352,8 +352,8 @@ let Class = FunctionProtoType in {
   def : Property<"AArch64SMEAttributes", UInt32> {
     let Read = [{ node->getAArch64SMEAttributes() }];
   }
-  def : Property<"functionEffects", Array<FunctionEffect>> {
-    let Read = [{ node->getFunctionEffects().items() }];
+  def : Property<"functionEffects", Array<CondFunctionEffect>> {
+    let Read = [{ node->getFunctionEffects() }];
   }
 
   def : Creator<[{
@@ -371,7 +371,7 @@ let Class = FunctionProtoType in {
     epi.ExtParameterInfos =
       extParameterInfo.empty() ? nullptr : extParameterInfo.data();
     epi.AArch64SMEAttributes = AArch64SMEAttributes;
-    epi.FunctionEffects = functionEffects;
+    epi.FunctionEffects = FunctionTypeEffects(functionEffects);
     return ctx.getFunctionType(returnType, parameters, epi);
   }]>;
 }
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 33d9160d510206..5951f44004d925 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -719,12 +719,6 @@ class Sema final {
   /// Load weak undeclared identifiers from the external source.
   void LoadExternalWeakUndeclaredIdentifiers();
 
-  /// All functions/lambdas/blocks which have bodies and which have a non-empty
-  /// FunctionEffectSet to be verified.
-  SmallVector<const Decl *> DeclsWithEffectsToVerify;
-  /// The union of all effects present on DeclsWithEffectsToVerify.
-  FunctionEffectSet AllEffectsToVerify;
-
   /// Determine if VD, which must be a variable or function, is an external
   /// symbol that nonetheless can't be referenced from outside this translation
   /// unit because its type has no linkage and it's not extern "C".
@@ -944,10 +938,26 @@ class Sema final {
   /// Warn when implicitly casting 0 to nullptr.
   void diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E);
 
+  // ----- function effects --- where ?????
+  // Ultimately some more of the effects implementation could/should be moved
+  // out of Type.h, but where to?
+
+  /// All functions/lambdas/blocks which have bodies and which have a non-empty
+  /// FunctionTypeEffects to be verified.
+  SmallVector<const Decl *> DeclsWithEffectsToVerify;
+  /// The union of all effects present on DeclsWithEffectsToVerify. Conditions
+  /// are all null.
+  FunctionTypeEffectSet AllEffectsToVerify;
+
   /// Warn when implicitly changing function effects.
   void diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
                                         SourceLocation Loc);
 
+  /// Potentially add a FunctionDecl or BlockDecl to DeclsWithEffectsToVerify.
+  void maybeAddDeclWithEffects(const Decl *D, const FunctionTypeEffects &FX);
+
+  // ----- function effects --- where ?????
+
   bool makeUnavailableInSystemHeader(SourceLocation loc,
                                      UnavailableAttr::ImplicitReason reason);
 
@@ -3154,9 +3164,6 @@ class Sema final {
                               QualType T, TypeSourceInfo *TSInfo,
                               StorageClass SC);
 
-  /// Potentially add a FunctionDecl or BlockDecl to DeclsWithEffectsToVerify.
-  void MaybeAddDeclWithEffects(const Decl *D, const FunctionEffectSet &FX);
-
   // Contexts where using non-trivial C union types can be disallowed. This is
   // passed to err_non_trivial_c_union_in_invalid_context.
   enum NonTrivialCUnionContext {
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index ee0550107d71e4..2893cd692f3eea 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -4563,11 +4563,11 @@ QualType ASTContext::getFunctionTypeInternal(
       QualType, SourceLocation, FunctionType::FunctionTypeExtraBitfields,
       FunctionType::FunctionTypeArmAttributes, FunctionType::ExceptionType,
       Expr *, FunctionDecl *, FunctionProtoType::ExtParameterInfo,
-      FunctionEffectSet, Qualifiers>(
+      CondFunctionEffect, Qualifiers>(
       NumArgs, EPI.Variadic, EPI.requiresFunctionProtoTypeExtraBitfields(),
       EPI.requiresFunctionProtoTypeArmAttributes(), ESH.NumExceptionType,
       ESH.NumExprPtr, ESH.NumFunctionDeclPtr,
-      EPI.ExtParameterInfos ? NumArgs : 0, EPI.FunctionEffects ? 1 : 0,
+      EPI.ExtParameterInfos ? NumArgs : 0, EPI.FunctionEffects.size(),
       EPI.TypeQuals.hasNonFastQualifiers() ? 1 : 0);
 
   auto *FTP = (FunctionProtoType *)Allocate(Size, alignof(FunctionProtoType));
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 3aecc17cf4ead5..f57f60b2cab993 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -4508,7 +4508,7 @@ unsigned FunctionDecl::getODRHash() {
 // Effects may differ between declarations, but they should be propagated from
 // old to new on any redeclaration, so it suffices to look at
 // getMostRecentDecl().
-FunctionEffectSet FunctionDecl::getFunctionEffects() const {
+FunctionTypeEffects FunctionDecl::getFunctionEffects() const {
   if (const auto *FPT =
           getMostRecentDecl()->getType()->getAs<FunctionProtoType>()) {
     return FPT->getFunctionEffects();
@@ -5240,7 +5240,7 @@ SourceRange BlockDecl::getSourceRange() const {
   return SourceRange(getLocation(), Body ? Body->getEndLoc() : getLocation());
 }
 
-FunctionEffectSet BlockDecl::getFunctionEffects() const {
+FunctionTypeEffects BlockDecl::getFunctionEffects() const {
   if (auto *TSI = getSignatureAsWritten()) {
     if (auto *FPT = TSI->getType()->getAs<FunctionProtoType>()) {
       return FPT->getFunctionEffects();
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index ae0d8e082492d4..069febb3e71e5b 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3640,11 +3640,12 @@ FunctionProtoType::FunctionProtoType(QualType result, ArrayRef<QualType> params,
 
   if (epi.FunctionEffects) {
     auto &ExtraBits = *getTrailingObjects<FunctionTypeExtraBitfields>();
-    ExtraBits.HasFunctionEffects = true;
-
-    // N.B. This is uninitialized storage.
-    FunctionEffectSet *PFX = getTrailingObjects<FunctionEffectSet>();
-    new (PFX) FunctionEffectSet(epi.FunctionEffects);
+    // TODO: bitfield overflow?
+    if (epi.FunctionEffects) {
+      ExtraBits.NumFunctionEffects = epi.FunctionEffects.size();
+      CondFunctionEffect *CFE = getTrailingObjects<CondFunctionEffect>();
+      std::copy(epi.FunctionEffects.begin(), epi.FunctionEffects.end(), CFE);
+    }
   }
 }
 
@@ -3718,7 +3719,7 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   // Note that valid type pointers are never ambiguous with anything else.
   //
   // The encoding grammar begins:
-  //      effects type type* bool int bool
+  //      type type* bool int bool
   // If that final bool is true, then there is a section for the EH spec:
   //      bool type*
   // This is followed by an optional "consumed argument" section of the
@@ -3729,15 +3730,12 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
   // Finally we have a trailing return type flag (bool)
   // combined with AArch64 SME Attributes, to save space:
   //      int
+  // combined with any FunctionEffects
   //
   // There is no ambiguity between the consumed arguments and an empty EH
   // spec because of the leading 'bool' which unambiguously indicates
   // whether the following bool is the EH spec or part of the arguments.
 
-  // TODO: The effect set is variable-length, though prefaced with a size.
-  // Does this create potential ambiguity?
-  epi.FunctionEffects.Profile(ID);
-
   ID.AddPointer(Result.getAsOpaquePtr());
   for (unsigned i = 0; i != NumParams; ++i)
     ID.AddPointer(ArgTys[i].getAsOpaquePtr());
@@ -3768,6 +3766,8 @@ void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID, QualType Result,
 
   epi.ExtInfo.Profile(ID);
   ID.AddInteger((epi.AArch64SMEAttributes << 1) | epi.HasTrailingReturn);
+
+  epi.FunctionEffects.Profile(ID);
 }
 
 void FunctionProtoType::Profile(llvm::FoldingSetNodeID &ID,
@@ -5043,16 +5043,16 @@ StringRef FunctionEffect::name() const {
 }
 
 bool FunctionEffect::shouldDiagnoseConversion(
-    bool Adding, QualType OldType, const FunctionEffectSet &OldFX,
-    QualType NewType, const FunctionEffectSet &NewFX) const {
+    bool Adding, QualType OldType, const FunctionTypeEffects &OldFX,
+    QualType NewType, const FunctionTypeEffects &NewFX) const {
 
   switch (kind()) {
   case Kind::NonAllocating:
     // nonallocating can't be added (spoofed) during a conversion, unless we
     // have nonblocking
     if (Adding) {
-      for (const auto &Effect : OldFX) {
-        if (Effect.kind() == Kind::NonBlocking)
+      for (const auto &CFE : OldFX) {
+        if (CFE.effect().kind() == Kind::NonBlocking)
           return false;
       }
     }
@@ -5068,8 +5068,8 @@ bool FunctionEffect::shouldDiagnoseConversion(
 
 bool FunctionEffect::shouldDiagnoseRedeclaration(
     bool Adding, const FunctionDecl &OldFunction,
-    const FunctionEffectSet &OldFX, const FunctionDecl &NewFunction,
-    const FunctionEffectSet &NewFX) const {
+    const FunctionTypeEffects &OldFX, const FunctionDecl &NewFunction,
+    const FunctionTypeEffects &NewFX) const {
   switch (kind()) {
   case Kind::NonAllocating:
   case Kind::NonBlocking:
@@ -5083,8 +5083,9 @@ bool FunctionEffect::shouldDiagnoseRedeclaration(
 }
 
 FunctionEffect::OverrideResult FunctionEffect::shouldDiagnoseMethodOverride(
-    bool Adding, const CXXMethodDecl &OldMethod, const FunctionEffectSet &OldFX,
-    const CXXMethodDecl &NewMethod, const FunctionEffectSet &NewFX) const {
+    bool Adding, const CXXMethodDecl &OldMethod,
+    const FunctionTypeEffects &OldFX, const CXXMethodDecl &NewMethod,
+    const FunctionTypeEffects &NewFX) const {
   switch (kind()) {
   case Kind::NonAllocating:
   case Kind::NonBlocking:
@@ -5132,7 +5133,7 @@ bool FunctionEffect::canInferOnFunction(const Decl &Callee) const {
 }
 
 bool FunctionEffect::shouldDiagnoseFunctionCall(
-    bool Direct, const FunctionEffectSet &CalleeFX) const {
+    bool Direct, ArrayRef<FunctionEffect> CalleeFX) const {
   switch (kind()) {
   case Kind::NonAllocating:
   case Kind::NonBlocking: {
@@ -5155,84 +5156,98 @@ bool FunctionEffect::shouldDiagnoseFunctionCall(
 
 // =====
 
-void FunctionEffectSet::Profile(llvm::FoldingSetNodeID &ID) const {
+void FunctionTypeEffects::Profile(llvm::FoldingSetNodeID &ID) const {
   ID.AddInteger(size());
-  if (PImpl)
-    for (const auto &Effect : *PImpl)
-      ID.AddInteger(llvm::to_underlying(Effect.kind()));
-}
-
-FunctionEffectSet &
-FunctionEffectSet::operator=(llvm::ArrayRef<FunctionEffect> Arr) {
-  if (Arr.empty()) {
-    PImpl.reset();
-  } else {
-    if (PImpl == nullptr)
-      PImpl = new ImplVec;
-    PImpl->assign(Arr.begin(), Arr.end());
+  for (const auto &CFE : Items) {
+    ID.AddInteger(llvm::to_underlying(CFE.effect().kind()));
+    ID.AddPointer(CFE.condition());
   }
-  return *this;
 }
 
-FunctionEffectSet
-FunctionEffectSet::getUnion(const FunctionEffectSet &RHS) const {
-  const FunctionEffectSet &LHS = *this;
+FunctionTypeEffectSet
+FunctionTypeEffectSet::getUnion(ArrayRef<CondFunctionEffect> LHS,
+                                ArrayRef<CondFunctionEffect> RHS) {
   // Optimize for either of the two sets being empty (very common).
   if (LHS.empty())
-    return RHS;
+    return FunctionTypeEffectSet(RHS);
   if (RHS.empty())
-    return LHS;
+    return FunctionTypeEffectSet(LHS);
 
   // Optimize for the two sets being identical (very common).
   if (LHS == RHS)
-    return LHS;
+    return FunctionTypeEffectSet(LHS);
 
-  ImplPtr PVec(new ImplVec);
-  PVec->reserve(LHS.size() + RHS.size());
+  FunctionTypeEffectSet Result;
+  Result.Impl.reserve(LHS.size() + RHS.size());
   std::set_union(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
-                 std::back_inserter(*PVec));
-  return FunctionEffectSet(std::move(PVec));
-}
-
-FunctionEffectSet
-FunctionEffectSet::getIntersection(const FunctionEffectSet &RHS) const {
-  const FunctionEffectSet &LHS = *this;
-  if (LHS.empty() || RHS.empty()) {
-    return {};
-  }
-
-  ImplPtr PVec(new ImplVec);
-  std::set_intersection(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
-                        std::back_inserter(*PVec));
-  return FunctionEffectSet(std::move(PVec));
+                 std::back_inserter(Result.Impl));
+  return Result;
 }
 
-FunctionEffectSet::Differences
-FunctionEffectSet::differences(const FunctionEffectSet &Old,
-                               const FunctionEffectSet &New) {
+FunctionTypeEffectSet::Differences
+FunctionTypeEffectSet::differences(const FunctionTypeEffects &Old,
+                                   const FunctionTypeEffects &New) {
   // TODO: Could be a one-pass algorithm.
   Differences Result;
-  for (const auto &Effect : New.getDifference(Old)) {
+  for (const auto &Effect : FunctionTypeEffectSet::difference(New, Old)) {
     Result.emplace_back(Effect, true);
   }
-  for (const auto &Effect : Old.getDifference(New)) {
+  for (const auto &Effect : FunctionTypeEffectSet::difference(Old, New)) {
     Result.emplace_back(Effect, false);
   }
   return Result;
 }
 
-FunctionEffectSet
-FunctionEffectSet::getDifference(const FunctionEffectSet &RHS) const {
-  const FunctionEffectSet &LHS = *this;
-  ImplPtr PVec(new ImplVec);
-
+FunctionTypeEffectSet
+FunctionTypeEffectSet::difference(ArrayRef<CondFunctionEffect> LHS,
+                                  ArrayRef<CondFunctionEffect> RHS) {
+  FunctionTypeEffectSet Result;
   std::set_difference(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
-                      std::back_inserter(*PVec));
-  return FunctionEffectSet(std::move(PVec));
+                      std::back_inserter(Result.Impl));
+  return Result;
+}
+
+void FunctionTypeEffectSet::insert(const CondFunctionEffect &Effect) {
+  auto *Iter = std::lower_bound(Impl.begin(), Impl.end(), Effect);
+  if (Iter == Impl.end() || *Iter != Effect) {
+    Impl.insert(Iter, Effect);
+  }
+}
+
+void FunctionTypeEffectSet::insert(ArrayRef<CondFunctionEffect> Arr) {
+  // TODO: For large RHS sets, use set_union or a custom insert-in-place
+  for (const auto &CFE : Arr) {
+    insert(CFE);
+  }
+}
+
+void FunctionTypeEffectSet::insertIgnoringConditions(
+    ArrayRef<CondFunctionEffect> Arr) {
+  // TODO: For large RHS sets, use set_union or a custom insert-in-place
+  for (const auto &CFE : Arr) {
+    insert(CondFunctionEffect(CFE.effect().kind(), nullptr));
+  }
+}
+
+LLVM_DUMP_METHOD void FunctionTypeEffects::dump(llvm::raw_ostream &OS) const {
+  OS << "Effects{";
+  bool First = true;
+  for (const auto &CFE : *this) {
+    if (!First)
+      OS << ", ";
+    else
+      First = false;
+    OS << CFE.effect().name();
+  }
+  OS << "}";
+}
+
+LLVM_DUMP_METHOD void FunctionTypeEffectSet::dump(llvm::raw_ostream &OS) const {
+  FunctionTypeEffects(*this).dump(OS);
 }
 
 // TODO: inline?
-FunctionEffectSet FunctionEffectSet::get(QualType QT) {
+FunctionTypeEffects FunctionTypeEffects::get(QualType QT) {
   if (QT->isReferenceType())
     QT = QT.getNonReferenceType();
   if (QT->isPointerType())
@@ -5252,41 +5267,3 @@ FunctionEffectSet FunctionEffectSet::get(QualType QT) {
 
   return {};
 }
-
-// For use in mutating methods: only allow mutating the vector in
-// place when we hold the only reference. Otherwise, copy it first.
-FunctionEffectSet::ImplVec &FunctionEffectSet::mutableVec() {
-  if (PImpl->UseCount() > 1)
-    PImpl = new ImplVec(*PImpl);
-  assert(PImpl->UseCount() == 1 && "mutating a shared function effect set");
-  return *PImpl;
-}
-
-void FunctionEffectSet::insert(const FunctionEffect &Effect) {
-  if (PImpl == nullptr)
-    PImpl = new ImplVec;
-  auto *Iter = std::lower_bound(PImpl->begin(), PImpl->end(), Effect);
-  if (Iter == PImpl->end() || *Iter != Effect) {
-    mutableVec().insert(Iter, Effect);
-  }
-}
-
-void FunctionEffectSet::insert(const FunctionEffectSet &Set) {
-  // TODO: For large RHS sets, use set_union or a custom insert-in-place
-  for (const auto &Effect : Set) {
-    insert(Effect);
-  }
-}
-
-LLVM_DUMP_METHOD void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
-  OS << "Effects{";
-  bool First = true;
-  for (const auto &Effect : *this) {
-    if (!First)
-      OS << ", ";
-    else
-      First = false;
-    OS << Effect.name();
-  }
-  OS << "}";
-}
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 89a66cd0700299..054aa3de413c83 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -998,11 +998,10 @@ void TypePrinter::printFunctionProtoAfter(const FunctionProtoType *T,
   }
   T->printExceptionSpecification(OS, Policy);
 
-  if (const FunctionEffectSet FX = T->getFunctionEffects()) {
-    for (const auto &Effect : FX) {
-      OS << " __attribute__((clang_" << Effect.name() << "))";
-    }
-  }
+  const FunctionTypeEffects FX = T->getFunctionEffects();
+  for (const auto &CFE : FX)
+    OS << " __attribute__((clang_" << CFE.effect().name() << "))";
+  // $$$ TODO: Conditions ???
 
   if (T->hasTrailingReturn()) {
     OS << " -> ";
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 947f5ff98f74d6..dacabfa8f32a67 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2384,6 +2384,11 @@ class UnsafeBufferUsageReporter : public UnsafeBufferUsageHandler {
 
 // =============================================================================
 
+// Temporary feature enablement
+#define FX_ANALYZER_ENABLED 1
+
+#if FX_ANALYZER_ENABLED
+
 // Temporary debugging option
 #define FX_ANALYZER_VERIFY_DECL_LIST 1
 
@@ -2448,6 +2453,133 @@ static bool functionIsVerifiable(const FunctionDecl *FD) {
   return true;
 }
 
+#if 0
+/// A mutable set of FunctionEffect, for use in places where any conditions
+/// have been resolved or can be ignored.
+class FunctionEffectSet {
+  SmallVector<FunctionEffect, 4> Impl;
+public:
+  FunctionEffectSet() = default;
+
+  operator ArrayRef<FunctionEffect>() const { return Impl; }
+
+  using iterator = const FunctionEffect *;
+  iterator begin() const { return Impl.begin(); }
+  iterator end() const { return Impl.end(); }
+
+  void insert(const FunctionEffect &Effect);
+  void insert(const FunctionEffectSet &Set);
+  void insertIgnoringConditions(ArrayRef<CondFunctionEffect> Arr);
+
+  void dump(llvm::raw_ostream &OS) const;
+
+  static FunctionEffectSet difference(ArrayRef<FunctionEffect> LHS, ArrayRef<FunctionEffect> RHS);
+};
+#endif
+
+/// A mutable set of FunctionEffect, for use in places where any conditions
+/// have been resolved or can be ignored.
+// (This implementation optimizes footprint. As long as FunctionEffect is only 1
+// byte, and there are only 2 possible effects, this is more than sufficient. In
+// AnalysisBasedWarnings, we hold one of these for every function visited,
+// which, due to inference, can be many more functions than have effects.)
+class FunctionEffectSet {
+  template <typename T, typename SizeT, SizeT Capacity> struct FixedVector {
+    SizeT Count = 0;
+    T Items[Capacity] = {};
+
+    using value_type = T;
+
+    using iterator = T *;
+    using const_iterator = const T *;
+    iterator begin() { return &Items[0]; }
+    iterator end() { return &Items[Count]; }
+    const_iterator cbegin() const { return &Items[0]; }
+    const_iterator cend() const { return &Items[Count]; }
+
+    void insert(iterator I, const T &Value) {
+      assert(Count < Capacity);
+      iterator E = end();
+      if (I != E)
+        std::copy_backward(I, E, E + 1);
+      *I = Value;
+      ++Count;
+    }
+
+    void push_back(const T &Value) {
+      assert(Count < Capacity);
+      Items[Count++] = Value;
+    }
+  };
+
+  FixedVector<FunctionEffect, uint8_t, 7> Impl;
+
+public:
+  FunctionEffectSet() = default;
+
+  operator ArrayRef<FunctionEffect>() const {
+    return ArrayRef(Impl.cbegin(), Impl.cend());
+  }
+
+  using iterator = const FunctionEffect *;
+  iterator begin() const { return Impl.cbegin(); }
+  iterator end() const { return Impl.cend(); }
+
+  void insert(const FunctionEffect &Effect);
+  void insert(const FunctionEffectSet &Set);
+  void insertIgnoringConditions(ArrayRef<CondFunctionEffect> Arr);
+
+  void dump(llvm::raw_ostream &OS) const;
+
+  static FunctionEffectSet difference(ArrayRef<FunctionEffect> LHS,
+                                      ArrayRef<FunctionEffect> RHS);
+};
+
+void FunctionEffectSet::insert(const FunctionEffect &Effect) {
+  FunctionEffect *Iter = Impl.begin();
+  FunctionEffect *End = Impl.end();
+  // lower_bound is overkill for a tiny vector like this
+  for (; Iter != End; ++Iter) {
+    if (*Iter == Effect)
+      return;
+    if (Effect < *Iter)
+      break;
+  }
+  Impl.insert(Iter, Effect);
+}
+
+void FunctionEffectSet::insert(const FunctionEffectSet &Set) {
+  for (auto &Item : Set)
+    insert(Item);
+}
+
+void FunctionEffectSet::insertIgnoringConditions(
+    ArrayRef<CondFunctionEffect> Arr) {
+  for (auto &Item : Arr)
+    insert(Item.effect());
+}
+
+LLVM_DUMP_METHOD void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
+  OS << "Effects{";
+  bool First = true;
+  for (const auto &Effect : *this) {
+    if (!First)
+      OS << ", ";
+    else
+      First = false;
+    OS << Effect.name();
+  }
+  OS << "}";
+}
+
+FunctionEffectSet FunctionEffectSet::difference(ArrayRef<FunctionEffect> LHS,
+                                                ArrayRef<FunctionEffect> RHS) {
+  FunctionEffectSet Result;
+  std::set_difference(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
+                      std::back_inserter(Result.Impl));
+  return Result;
+}
+
 // Transitory, more extended information about a callable, which can be a
 // function, block, function pointer...
 struct CallableInfo {
@@ -2462,6 +2594,7 @@ struct CallableInfo {
   CallableInfo(const Decl &CD, SpecialFuncType FT = SpecialFuncType::None)
       : CDecl(&CD), FuncType(FT) {
     // llvm::errs() << "CallableInfo " << name() << "\n";
+    FunctionTypeEffects FX;
 
     if (auto *FD = dyn_cast<FunctionDecl>(CDecl)) {
       // Use the function's definition, if any.
@@ -2474,14 +2607,15 @@ struct CallableInfo {
           CType = CallType::Virtual;
         }
       }
-      Effects = FD->getFunctionEffects();
+      FX = FD->getFunctionEffects();
     } else if (auto *BD = dyn_cast<BlockDecl>(CDecl)) {
       CType = CallType::Block;
-      Effects = BD->getFunctionEffects();
+      FX = BD->getFunctionEffects();
     } else if (auto *VD = dyn_cast<ValueDecl>(CDecl)) {
       // ValueDecl is function, enum, or variable, so just look at its type.
-      Effects = FunctionEffectSet::get(VD->getType());
+      FX = FunctionTypeEffects::get(VD->getType());
     }
+    Effects.insertIgnoringConditions(FX);
   }
 
   bool isDirectCall() const {
@@ -2574,8 +2708,8 @@ class EffectToDiagnosticMap {
 // ----------
 // State pertaining to a function whose AST is walked. Since there are
 // potentially a large number of these objects, it needs care about size.
+// TODO: FunctionEffectSet could be made much smaller.
 class PendingFunctionAnalysis {
-  // Current size: 5 pointers
   friend class CompleteFunctionAnalysis;
 
   struct DirectCall {
@@ -2615,7 +2749,7 @@ class PendingFunctionAnalysis {
 public:
   PendingFunctionAnalysis(
       Sema &Sem, const CallableInfo &CInfo,
-      const FunctionEffectSet &AllInferrableEffectsToVerify) {
+      ArrayRef<FunctionEffect> AllInferrableEffectsToVerify) {
     DeclaredVerifiableEffects = CInfo.Effects;
 
     // Check for effects we are not allowed to infer
@@ -2635,7 +2769,7 @@ class PendingFunctionAnalysis {
       }
     }
     // FX is now the set of inferrable effects which are not prohibited
-    FXToInfer = FX.getDifference(DeclaredVerifiableEffects);
+    FXToInfer = FunctionEffectSet::difference(FX, DeclaredVerifiableEffects);
   }
 
   // Hide the way that diagnostics for explicitly required effects vs. inferred
@@ -2719,7 +2853,7 @@ class CompleteFunctionAnalysis {
   CompleteFunctionAnalysis(
       ASTContext &Ctx, PendingFunctionAnalysis &pending,
       const FunctionEffectSet &funcFX,
-      const FunctionEffectSet &AllInferrableEffectsToVerify) {
+      ArrayRef<FunctionEffect> AllInferrableEffectsToVerify) {
     VerifiedEffects.insert(funcFX);
     for (const auto &effect : AllInferrableEffectsToVerify) {
       if (pending.diagnosticForInferrableEffect(effect) == nullptr) {
@@ -2832,10 +2966,11 @@ class Analyzer {
     // Gather all of the effects to be verified to see what operations need to
     // be checked, and to see which ones are inferrable.
     {
-      for (const FunctionEffect &effect : Sem.AllEffectsToVerify) {
-        const auto Flags = effect.flags();
+      for (const CondFunctionEffect &CFE : Sem.AllEffectsToVerify) {
+        const FunctionEffect &Effect = CFE.effect();
+        const auto Flags = Effect.flags();
         if (Flags & FunctionEffect::FE_InferrableOnCallees) {
-          AllInferrableEffectsToVerify.insert(effect);
+          AllInferrableEffectsToVerify.insert(Effect);
         }
       }
       if constexpr (DebugLogLevel > 0) {
@@ -3309,11 +3444,14 @@ class Analyzer {
       const auto CalleeType = CalleeExpr->getType();
       auto *FPT =
           CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
+      FunctionEffectSet CalleeFX;
+      if (FPT)
+        CalleeFX.insertIgnoringConditions(FPT->getFunctionEffects());
+      static_assert(sizeof(FunctionEffect) == 1);
 
       auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
-        if (FPT == nullptr ||
-            Effect.shouldDiagnoseFunctionCall(
-                /*direct=*/false, FPT->getFunctionEffects())) {
+        if (FPT == nullptr || Effect.shouldDiagnoseFunctionCall(
+                                  /*direct=*/false, CalleeFX)) {
           addDiagnosticInner(Inferring, Effect,
                              DiagnosticID::CallsDisallowedExpr,
                              Call->getBeginLoc());
@@ -3582,12 +3720,12 @@ class Analyzer {
       if (auto *Callable = Result.Nodes.getNodeAs<Decl>(Tag_Callable)) {
         if (const auto FX = functionEffectsForDecl(Callable)) {
           // Reuse this filtering method in Sema
-          Sem.MaybeAddDeclWithEffects(Callable, FX);
+          Sem.maybeAddDeclWithEffects(Callable, FX);
         }
       }
     }
 
-    static FunctionEffectSet functionEffectsForDecl(const Decl *D) {
+    static FunctionTypeEffects functionEffectsForDecl(const Decl *D) {
       if (auto *FD = D->getAsFunction()) {
         return FD->getFunctionEffects();
       }
@@ -3649,6 +3787,7 @@ Analyzer::AnalysisMap::~AnalysisMap() {
 }
 
 } // namespace FXAnalysis
+#endif // FX_ANALYZER_ENABLED
 
 // =============================================================================
 
@@ -3807,8 +3946,10 @@ void clang::sema::AnalysisBasedWarnings::IssueWarnings(
     CallableVisitor(CallAnalyzers).TraverseTranslationUnitDecl(TU);
   }
 
+#if FX_ANALYZER_ENABLED
   // TODO: skip this if the warning isn't enabled.
   FXAnalysis::Analyzer{S}.run(*TU);
+#endif
 }
 
 void clang::sema::AnalysisBasedWarnings::IssueWarnings(
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 01d334f8d8af90..fdef8dc9f877f3 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -590,11 +590,11 @@ void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
 // Generate diagnostics when adding or removing effects in a type conversion.
 void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
                                             SourceLocation Loc) {
-  const auto SrcFX = FunctionEffectSet::get(SrcType);
-  const auto DstFX = FunctionEffectSet::get(DstType);
+  const auto SrcFX = FunctionTypeEffects::get(SrcType);
+  const auto DstFX = FunctionTypeEffects::get(DstType);
   if (SrcFX != DstFX) {
-    for (const auto &Item : FunctionEffectSet::differences(SrcFX, DstFX)) {
-      const FunctionEffect &Effect = Item.first;
+    for (const auto &Item : FunctionTypeEffectSet::differences(SrcFX, DstFX)) {
+      const FunctionEffect &Effect = Item.first.effect();
       const bool Adding = Item.second;
       if (Effect.shouldDiagnoseConversion(Adding, SrcType, SrcFX, DstType,
                                           DstFX)) {
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 3421709fd24aa8..1a48d759e3a8ec 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3924,9 +3924,9 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
   const auto NewFX = New->getFunctionEffects();
   QualType OldQTypeForComparison = OldQType;
   if (OldFX != NewFX) {
-    const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
+    const auto Diffs = FunctionTypeEffectSet::differences(OldFX, NewFX);
     for (const auto &Item : Diffs) {
-      const FunctionEffect &Effect = Item.first;
+      const FunctionEffect &Effect = Item.first.effect();
       const bool Adding = Item.second;
       if (Effect.shouldDiagnoseRedeclaration(Adding, *Old, OldFX, *New,
                                              NewFX)) {
@@ -3940,10 +3940,10 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
     // declaration, but that would trigger an additional "conflicting types"
     // error.
     if (const auto *NewFPT = NewQType->getAs<FunctionProtoType>()) {
-      auto MergedFX = OldFX.getUnion(NewFX);
+      auto MergedFX = FunctionTypeEffectSet::getUnion(OldFX, NewFX);
 
       FunctionProtoType::ExtProtoInfo EPI = NewFPT->getExtProtoInfo();
-      EPI.FunctionEffects = MergedFX;
+      EPI.FunctionEffects = FunctionTypeEffects(MergedFX);
       QualType ModQT = Context.getFunctionType(NewFPT->getReturnType(),
                                                NewFPT->getParamTypes(), EPI);
 
@@ -3954,7 +3954,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
       // so as not to fail due to differences later.
       if (const auto *OldFPT = OldQType->getAs<FunctionProtoType>()) {
         EPI = OldFPT->getExtProtoInfo();
-        EPI.FunctionEffects = MergedFX;
+        EPI.FunctionEffects = FunctionTypeEffects(MergedFX);
         OldQTypeForComparison = Context.getFunctionType(
             OldFPT->getReturnType(), OldFPT->getParamTypes(), EPI);
       }
@@ -11128,7 +11128,8 @@ Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
 
 // Should only be called when getFunctionEffects() returns a non-empty set.
 // Decl should be a FunctionDecl or BlockDecl.
-void Sema::MaybeAddDeclWithEffects(const Decl *D, const FunctionEffectSet &FX) {
+void Sema::maybeAddDeclWithEffects(const Decl *D,
+                                   const FunctionTypeEffects &FX) {
   if (!D->hasBody()) {
     if (const auto *FD = D->getAsFunction()) {
       if (!FD->willHaveBody()) {
@@ -11152,7 +11153,8 @@ void Sema::MaybeAddDeclWithEffects(const Decl *D, const FunctionEffectSet &FX) {
     return;
   }
 
-  AllEffectsToVerify.insert(FX);
+  // Ignore any conditions when building the list of effects.
+  AllEffectsToVerify.insertIgnoringConditions(FX);
 
   // Record the declaration for later analysis.
   DeclsWithEffectsToVerify.push_back(D);
@@ -16064,7 +16066,7 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
     Diag(FD->getLocation(), diag::warn_function_def_in_objc_container);
 
   if (const auto FX = FD->getCanonicalDecl()->getFunctionEffects()) {
-    MaybeAddDeclWithEffects(FD, FX);
+    maybeAddDeclWithEffects(FD, FX);
   }
 
   return D;
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 95b8d4231b4014..4c5e47c66ee5b3 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18329,11 +18329,11 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
   const auto NewFX = New->getFunctionEffects();
 
   if (OldFX != NewFX) {
-    const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
+    const auto Diffs = FunctionTypeEffectSet::differences(OldFX, NewFX);
     bool AnyDiags = false;
 
     for (const auto &Item : Diffs) {
-      const FunctionEffect &Effect = Item.first;
+      const FunctionEffect &Effect = Item.first.effect();
       const bool Adding = Item.second;
       switch (Effect.shouldDiagnoseMethodOverride(Adding, *Old, OldFX, *New,
                                                   NewFX)) {
@@ -18347,10 +18347,10 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
         AnyDiags = true;
         break;
       case FunctionEffect::OverrideResult::Merge: {
-        auto MergedFX = OldFX.getUnion(NewFX);
+        auto MergedFX = FunctionTypeEffectSet::getUnion(OldFX, NewFX);
 
         FunctionProtoType::ExtProtoInfo EPI = NewFT->getExtProtoInfo();
-        EPI.FunctionEffects = MergedFX;
+        EPI.FunctionEffects = FunctionTypeEffects(MergedFX);
         QualType ModQT = Context.getFunctionType(NewFT->getReturnType(),
                                                  NewFT->getParamTypes(), EPI);
         New->setType(ModQT);
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 2b4e1693cb1f1e..d5cfc4669c9ab9 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -17157,7 +17157,7 @@ ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc,
   BlockDecl *BD = BSI->TheDecl;
 
   if (const auto FX = BD->getFunctionEffects()) {
-    MaybeAddDeclWithEffects(BD, FX);
+    maybeAddDeclWithEffects(BD, FX);
   }
 
   if (BSI->HasImplicitReturnType)
diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index 0772a2dec7b560..bb6ee041ad9446 100644
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -1890,7 +1890,7 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body) {
   ActOnFinishFunctionBody(LSI.CallOperator, Body);
 
   if (const auto FX = LSI.CallOperator->getFunctionEffects()) {
-    MaybeAddDeclWithEffects(LSI.CallOperator, FX);
+    maybeAddDeclWithEffects(LSI.CallOperator, FX);
   }
 
   return BuildLambdaExpr(StartLoc, Body->getEndLoc(), &LSI);
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 08fce7ac781ce3..542853050bae41 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8084,8 +8084,6 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
       if (NewState == BoolAttrState::False) {
         return incompatible(true, BoolAttrState::True);
       }
-      // Ignore nonallocating(true) since we already have nonblocking(true).
-      return true;
     }
     TPState.setParsedNonAllocating(NewState);
   }
@@ -8118,13 +8116,16 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
   }
 
   // nonblocking(true) and nonallocating(true) are represented as
-  // FunctionEffects, in a FunctionEffectSet attached to a FunctionProtoType.
-  const FunctionEffect NewEffect(isNonBlocking
-                                     ? FunctionEffect::Kind::NonBlocking
-                                     : FunctionEffect::Kind::NonAllocating);
+  // FunctionEffects, in a FunctionTypeEffects attached to a FunctionProtoType.
+  const CondFunctionEffect NewEffect(isNonBlocking
+                                         ? FunctionEffect::Kind::NonBlocking
+                                         : FunctionEffect::Kind::NonAllocating,
+                                     nullptr /* no condition yet */);
 
   FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
-  EPI.FunctionEffects.insert(NewEffect);
+  FunctionTypeEffectSet FX(EPI.FunctionEffects);
+  FX.insert(NewEffect);
+  EPI.FunctionEffects = FunctionTypeEffects(FX);
 
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
                                                FPT->getParamTypes(), EPI);
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 2648f46b414226..d4bd45f3b7434b 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -8226,14 +8226,14 @@ void ASTReader::InitializeSema(Sema &S) {
       Decl *D = GetDecl(ID);
       SemaObj->DeclsWithEffectsToVerify.push_back(D);
 
-      FunctionEffectSet FX;
+      FunctionTypeEffects FX;
       if (auto *FD = dyn_cast<FunctionDecl>(D)) {
         FX = FD->getFunctionEffects();
       } else if (auto *BD = dyn_cast<BlockDecl>(D)) {
         FX = BD->getFunctionEffects();
       }
       if (FX) {
-        SemaObj->AllEffectsToVerify.insert(FX);
+        SemaObj->AllEffectsToVerify.insertIgnoringConditions(FX);
       }
     }
     DeclsWithEffectsToVerify.clear();
diff --git a/clang/test/Sema/attr-nonblocking-syntax.cpp b/clang/test/Sema/attr-nonblocking-syntax.cpp
index 8fe3cfe529df49..f6f58f95fd70db 100644
--- a/clang/test/Sema/attr-nonblocking-syntax.cpp
+++ b/clang/test/Sema/attr-nonblocking-syntax.cpp
@@ -40,15 +40,15 @@ struct Struct {
 // CHECK: FieldDecl {{.*}} nl_func_field 'void (*)() __attribute__((clang_nonblocking))'
 };
 
-// nonallocating should be subsumed into nonblocking
+// nonallocating should NOT be subsumed into nonblocking
 void nl1() [[clang::nonblocking]] [[clang::nonallocating]];
-// CHECK: FunctionDecl {{.*}} nl1 'void () __attribute__((clang_nonblocking))'
+// CHECK: FunctionDecl {{.*}} nl1 'void () __attribute__((clang_nonblocking)) __attribute__((clang_nonallocating))'
 
 void nl2() [[clang::nonallocating]] [[clang::nonblocking]];
 // CHECK: FunctionDecl {{.*}} nl2 'void () __attribute__((clang_nonblocking)) __attribute__((clang_nonallocating))'
 
 decltype(nl1) nl3;
-// CHECK: FunctionDecl {{.*}} nl3 'decltype(nl1)':'void () __attribute__((clang_nonblocking))'
+// CHECK: FunctionDecl {{.*}} nl3 'decltype(nl1)':'void () __attribute__((clang_nonblocking)) __attribute__((clang_nonallocating))'
 
 // Attribute propagates from base class virtual method to overrides.
 struct Base {

>From 60455738256ccb41fa707172c50e03b2b91c709a Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Mon, 15 Apr 2024 15:34:05 -0700
Subject: [PATCH 32/40] Separate effects and conditions.

---
 clang/include/clang/AST/AbstractBasicReader.h |   9 +-
 clang/include/clang/AST/AbstractBasicWriter.h |   9 +-
 clang/include/clang/AST/Decl.h                |   4 +-
 clang/include/clang/AST/PropertiesBase.td     |   3 +-
 clang/include/clang/AST/Type.h                | 256 ++++++++++++------
 clang/include/clang/AST/TypeProperties.td     |   9 +-
 clang/include/clang/Sema/Sema.h               |   4 +-
 clang/lib/AST/ASTContext.cpp                  |   3 +-
 clang/lib/AST/Decl.cpp                        |   4 +-
 clang/lib/AST/Type.cpp                        | 176 ++++++++----
 clang/lib/AST/TypePrinter.cpp                 |   4 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp      |  18 +-
 clang/lib/Sema/Sema.cpp                       |   6 +-
 clang/lib/Sema/SemaDecl.cpp                   |  11 +-
 clang/lib/Sema/SemaDeclCXX.cpp                |   4 +-
 clang/lib/Sema/SemaExpr.cpp                   |   2 +-
 clang/lib/Sema/SemaLambda.cpp                 |   2 +-
 clang/lib/Sema/SemaType.cpp                   |  14 +-
 clang/lib/Serialization/ASTReader.cpp         |   4 +-
 19 files changed, 356 insertions(+), 186 deletions(-)

diff --git a/clang/include/clang/AST/AbstractBasicReader.h b/clang/include/clang/AST/AbstractBasicReader.h
index 7ab4cad4791618..f932b7608d474b 100644
--- a/clang/include/clang/AST/AbstractBasicReader.h
+++ b/clang/include/clang/AST/AbstractBasicReader.h
@@ -244,12 +244,15 @@ class DataStreamBasicReader : public BasicReaderBase<Impl> {
     return FunctionProtoType::ExtParameterInfo::getFromOpaqueValue(value);
   }
 
-  CondFunctionEffect readCondFunctionEffect() {
+  FunctionEffect readFunctionEffect() {
     static_assert(sizeof(FunctionEffect::Kind) <= sizeof(uint32_t),
                   "update this if size changes");
     uint32_t value = asImpl().readUInt32();
-    Expr *cond = asImpl().readExprRef();
-    return CondFunctionEffect(static_cast<FunctionEffect::Kind>(value), cond);
+    return FunctionEffect(static_cast<FunctionEffect::Kind>(value));
+  }
+
+  FunctionEffectCondExpr readFunctionEffectCondExpr() {
+    return FunctionEffectCondExpr{asImpl().readExprRef()};
   }
 
   NestedNameSpecifier *readNestedNameSpecifier() {
diff --git a/clang/include/clang/AST/AbstractBasicWriter.h b/clang/include/clang/AST/AbstractBasicWriter.h
index 24d6d18d9e8b44..51dc280efcd9cd 100644
--- a/clang/include/clang/AST/AbstractBasicWriter.h
+++ b/clang/include/clang/AST/AbstractBasicWriter.h
@@ -222,11 +222,14 @@ class DataStreamBasicWriter : public BasicWriterBase<Impl> {
     asImpl().writeUInt32(epi.getOpaqueValue());
   }
 
-  void writeCondFunctionEffect(const CondFunctionEffect &effect) {
+  void writeFunctionEffect(FunctionEffect E) {
     static_assert(sizeof(FunctionEffect::Kind) <= sizeof(uint32_t),
                   "update this if the value size changes");
-    asImpl().writeUInt32(llvm::to_underlying(effect.effect().kind()));
-    asImpl().writeExprRef(effect.condition());
+    asImpl().writeUInt32(llvm::to_underlying(E.kind()));
+  }
+
+  void writeFunctionEffectCondExpr(FunctionEffectCondExpr CE) {
+    asImpl().writeExprRef(CE.Cond);
   }
 
   void writeNestedNameSpecifier(NestedNameSpecifier *NNS) {
diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index 0709223042ad45..71aed63c87258b 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -3008,7 +3008,7 @@ class FunctionDecl : public DeclaratorDecl,
   /// computed and stored.
   unsigned getODRHash() const;
 
-  FunctionTypeEffects getFunctionEffects() const;
+  FunctionTypeEffectsRef getFunctionEffects() const;
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
@@ -4635,7 +4635,7 @@ class BlockDecl : public Decl, public DeclContext {
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
-  FunctionTypeEffects getFunctionEffects() const;
+  FunctionTypeEffectsRef getFunctionEffects() const;
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
diff --git a/clang/include/clang/AST/PropertiesBase.td b/clang/include/clang/AST/PropertiesBase.td
index 157d75ccdd584d..b596b22d943296 100644
--- a/clang/include/clang/AST/PropertiesBase.td
+++ b/clang/include/clang/AST/PropertiesBase.td
@@ -117,7 +117,8 @@ def ExtParameterInfo : PropertyType<"FunctionProtoType::ExtParameterInfo">;
 def FixedPointSemantics : PropertyType<"llvm::FixedPointSemantics"> {
   let PassByReference = 1;
 }
-def CondFunctionEffect : PropertyType<"CondFunctionEffect">;
+def FunctionEffect : PropertyType<"FunctionEffect">;
+def FunctionEffectCondExpr : PropertyType<"FunctionEffectCondExpr">;
 def Identifier : RefPropertyType<"IdentifierInfo"> { let ConstWhenWriting = 1; }
 def LValuePathEntry : PropertyType<"APValue::LValuePathEntry">;
 def LValuePathSerializationHelper :
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 552aca902f658d..dad5eacbaea6bb 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4295,11 +4295,13 @@ class FunctionType : public Type {
     LLVM_PREFERRED_TYPE(bool)
     unsigned HasArmTypeAttributes : 1;
 
+    LLVM_PREFERRED_TYPE(bool)
+    unsigned EffectsHaveConditions : 1;
     unsigned NumFunctionEffects : 4;
 
     FunctionTypeExtraBitfields()
         : NumExceptionType(0), HasArmTypeAttributes(false),
-          NumFunctionEffects(0) {}
+          EffectsHaveConditions(false), NumFunctionEffects(0) {}
   };
 
   /// The AArch64 SME ACLE (Arm C/C++ Language Extensions) define a number
@@ -4436,9 +4438,25 @@ class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
 
 class Decl;
 class CXXMethodDecl;
-class FunctionTypeEffects;
+class FunctionTypeEffectsRef;
 class FunctionTypeEffectSet;
 
+/*
+  TODO: Idea about how to move most of the FunctionEffect business out of
+  Type.h, thus removing these forward declarations.
+
+  - Keep FunctionEffect itself here but make it more minimal. Don't define flags
+  or any behaviors, just the Kind and an accessor.
+  - Keep FunctionEffectCondExpr here.
+  - Make FunctionProtoType and ExtProtoInfo use only ArrayRef<FunctionEffect>
+  and ArrayRef<FunctionEffectCondExpr>.
+  - Somewhere in Sema, define ExtFunctionEffect, which holds a FunctionEffect
+    and has all the behavior-related methods.
+  - There too, define the containers. FunctionTypeEffectsRef can have a
+  constructor or factory method that initializes itself from a
+  FunctionProtoType.
+*/
+
 /// Represents an abstract function effect, using just an enumeration describing
 /// its kind.
 class FunctionEffect {
@@ -4511,24 +4529,24 @@ class FunctionEffect {
   /// Return true if adding or removing the effect as part of a type conversion
   /// should generate a diagnostic.
   bool shouldDiagnoseConversion(bool Adding, QualType OldType,
-                                const FunctionTypeEffects &OldFX,
+                                const FunctionTypeEffectsRef &OldFX,
                                 QualType NewType,
-                                const FunctionTypeEffects &NewFX) const;
+                                const FunctionTypeEffectsRef &NewFX) const;
 
   /// Return true if adding or removing the effect in a redeclaration should
   /// generate a diagnostic.
   bool shouldDiagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
-                                   const FunctionTypeEffects &OldFX,
+                                   const FunctionTypeEffectsRef &OldFX,
                                    const FunctionDecl &NewFunction,
-                                   const FunctionTypeEffects &NewFX) const;
+                                   const FunctionTypeEffectsRef &NewFX) const;
 
   /// Return true if adding or removing the effect in a C++ virtual method
   /// override should generate a diagnostic.
   OverrideResult
   shouldDiagnoseMethodOverride(bool Adding, const CXXMethodDecl &OldMethod,
-                               const FunctionTypeEffects &OldFX,
+                               const FunctionTypeEffectsRef &OldFX,
                                const CXXMethodDecl &NewMethod,
-                               const FunctionTypeEffects &NewFX) const;
+                               const FunctionTypeEffectsRef &NewFX) const;
 
   /// Return true if the effect is allowed to be inferred on the callee,
   /// which is either a FunctionDecl or BlockDecl.
@@ -4553,78 +4571,97 @@ class FunctionEffect {
   friend bool operator<(const FunctionEffect &LHS, const FunctionEffect &RHS) {
     return LHS.FKind < RHS.FKind;
   }
+  friend bool operator>(const FunctionEffect &LHS, const FunctionEffect &RHS) {
+    return LHS.FKind > RHS.FKind;
+  }
+};
+
+/// Wrap a function effect's condition expression in another struct so
+/// that FunctionProtoType's TrailingObjects can treat it separately.
+struct FunctionEffectCondExpr {
+  const Expr *Cond = nullptr; // if null, unconditional
+
+  bool operator==(const FunctionEffectCondExpr &RHS) const {
+    return Cond == RHS.Cond;
+  }
 };
 
 /// A FunctionEffect plus a potential boolean expression determining whether
 /// the effect is declared (e.g. nonblocking(expr)). Generally the condition
 /// expression when present, is dependent.
-class CondFunctionEffect {
+struct CondFunctionEffect {
   FunctionEffect Effect;
   const Expr *Cond = nullptr; // if null, unconditional
+};
 
-public:
-  CondFunctionEffect() = default;
-  CondFunctionEffect(FunctionEffect::Kind K, const Expr *Cond)
-      : Effect(K), Cond(Cond) {}
-
-  const FunctionEffect &effect() const { return Effect; }
-  const Expr *condition() const { return Cond; }
-
-private:
-  // Comparisons are tricky when the condition might be involved, so limit who
-  // might be doing them.
-  friend FunctionTypeEffects;
-  friend FunctionTypeEffectSet;
+/// Support iteration in parallel through a pair of FunctionEffect and
+/// FunctionEffectCondExpr containers.
+template <typename Container> class FunctionEffectIterator {
+  const Container &Outer;
+  size_t Idx;
 
-  friend bool operator==(const CondFunctionEffect &LHS,
-                         const CondFunctionEffect &RHS) {
-    return LHS.Effect == RHS.Effect && LHS.Cond == RHS.Cond;
+public:
+  FunctionEffectIterator(const Container &O, size_t I) : Outer(O), Idx(I) {}
+  bool operator==(const FunctionEffectIterator &Other) const {
+    return Idx == Other.Idx;
   }
-  friend bool operator!=(const CondFunctionEffect &LHS,
-                         const CondFunctionEffect &RHS) {
-    return !(LHS == RHS);
+  bool operator!=(const FunctionEffectIterator &Other) const {
+    return Idx != Other.Idx;
+  }
+
+  // prefix increment
+  FunctionEffectIterator operator++() {
+    ++Idx;
+    return *this;
   }
-  friend bool operator<(const CondFunctionEffect &LHS,
-                        const CondFunctionEffect &RHS) {
-    return LHS.Effect < RHS.Effect;
+
+  CondFunctionEffect operator*() const {
+    const bool HasConds = !Outer.Conditions.empty();
+    return CondFunctionEffect{Outer.Effects[Idx],
+                              HasConds ? Outer.Conditions[Idx].Cond : nullptr};
   }
 };
 
-// Container naming:
-// "type effects" are the ones which include a condition
-// FunctionTypeEffectsRef - holds pointers
-// FunctionTypeEffectSet - mutable
-// FunctionEffectSet - mutable, no condition
+/// An immutable set of FunctionEffects and possibly conditions attached to
+/// them. The effects and conditions reside in memory not managed by this object
+/// (typically, trailing objects in FunctionProtoType, or borrowed references
+/// from a FunctionTypeEffectSet).
+class FunctionTypeEffectsRef {
+  ArrayRef<FunctionEffect> Effects;
 
-/// An immutable set of CondFunctionEffect. The effects reside in memory not
-/// managed by this object (typically, trailing objects in FunctionProtoType).
-class FunctionTypeEffects {
-  ArrayRef<CondFunctionEffect> Items;
+  // The array of conditions is either empty or has the same size
+  // as the array of effects.
+  ArrayRef<FunctionEffectCondExpr> Conditions;
 
 public:
   /// Extract the effects from a Type if it is a function, block, or member
   /// function pointer, or a reference or pointer to one.
-  static FunctionTypeEffects get(QualType QT);
+  static FunctionTypeEffectsRef get(QualType QT);
 
-  FunctionTypeEffects() = default;
+  FunctionTypeEffectsRef() = default;
 
-  // The array is expected to have been sorted by the caller.
-  explicit FunctionTypeEffects(ArrayRef<CondFunctionEffect> Arr) : Items(Arr) {}
+  // The arrays are expected to have been sorted by the caller.
+  FunctionTypeEffectsRef(ArrayRef<FunctionEffect> FX,
+                         ArrayRef<FunctionEffectCondExpr> Conds)
+      : Effects(FX), Conditions(Conds) {}
 
-  operator bool() const { return !Items.empty(); }
-  size_t size() const { return Items.size(); }
-  operator ArrayRef<CondFunctionEffect>() const { return Items; }
+  bool empty() const { return Effects.empty(); }
+  size_t size() const { return Effects.size(); }
 
-  using iterator = const CondFunctionEffect *;
-  iterator begin() const { return Items.begin(); }
-  iterator end() const { return Items.end(); }
+  ArrayRef<FunctionEffect> effects() const { return Effects; }
+  ArrayRef<FunctionEffectCondExpr> conditions() const { return Conditions; }
 
-  friend bool operator==(const FunctionTypeEffects &LHS,
-                         const FunctionTypeEffects &RHS) {
-    return LHS.Items == RHS.Items;
+  using iterator = FunctionEffectIterator<FunctionTypeEffectsRef>;
+  friend iterator;
+  iterator begin() const { return iterator(*this, 0); }
+  iterator end() const { return iterator(*this, size()); }
+
+  friend bool operator==(const FunctionTypeEffectsRef &LHS,
+                         const FunctionTypeEffectsRef &RHS) {
+    return LHS.Effects == RHS.Effects && LHS.Conditions == RHS.Conditions;
   }
-  friend bool operator!=(const FunctionTypeEffects &LHS,
-                         const FunctionTypeEffects &RHS) {
+  friend bool operator!=(const FunctionTypeEffectsRef &LHS,
+                         const FunctionTypeEffectsRef &RHS) {
     return !(LHS == RHS);
   }
 
@@ -4632,44 +4669,47 @@ class FunctionTypeEffects {
   void dump(llvm::raw_ostream &OS) const;
 };
 
-/// A mutable set of CondFunctionEffect.
-// Used transitorily within Sema to compare and merge effects on declarations.
+/// A mutable set of FunctionEffects and possibly conditions attached to them.
+/// Used transitorily within Sema to compare and merge effects on declarations.
 class FunctionTypeEffectSet {
-  SmallVector<CondFunctionEffect> Impl;
+  SmallVector<FunctionEffect> Effects;
+  // The vector of conditions is either empty or has the same size
+  // as the vector of effects.
+  SmallVector<FunctionEffectCondExpr> Conditions;
 
 public:
   FunctionTypeEffectSet() = default;
-  explicit FunctionTypeEffectSet(ArrayRef<CondFunctionEffect> Arr)
-      : Impl(Arr.begin(), Arr.end()) {}
 
-  explicit operator bool() const { return !Impl.empty(); }
+  explicit FunctionTypeEffectSet(const FunctionTypeEffectsRef &FX)
+      : Effects(FX.effects()), Conditions(FX.conditions()) {}
+
+  bool empty() const { return Effects.empty(); }
+  size_t size() const { return Effects.size(); }
 
-  // Implicit conversion to ArrayRef - careful with lifetime.
-  operator ArrayRef<CondFunctionEffect>() const { return Impl; }
+  using iterator = FunctionEffectIterator<FunctionTypeEffectSet>;
+  friend iterator;
+  iterator begin() const { return iterator(*this, 0); }
+  iterator end() const { return iterator(*this, size()); }
 
-  using iterator = const CondFunctionEffect *;
-  iterator begin() const { return Impl.begin(); }
-  iterator end() const { return Impl.end(); }
+  operator FunctionTypeEffectsRef() const { return {Effects, Conditions}; }
 
   void dump(llvm::raw_ostream &OS) const;
 
   // Mutators
-  void insert(const CondFunctionEffect &Effect);
-  void insert(ArrayRef<CondFunctionEffect> Arr);
-  void insertIgnoringConditions(ArrayRef<CondFunctionEffect> Arr);
+  void insert(FunctionEffect Effect, const Expr *Cond);
+  void insert(const FunctionTypeEffectsRef &Set);
+  void insertIgnoringConditions(const FunctionTypeEffectsRef &Set);
 
-  // Set operations, using ArrayRef to support FunctionTypeEffects
+  // Set operations
 
   using Differences =
       SmallVector<std::pair<CondFunctionEffect, /*added=*/bool>>;
   /// Caller should short-circuit by checking for equality first.
-  static Differences differences(const FunctionTypeEffects &Old,
-                                 const FunctionTypeEffects &New);
+  static Differences differences(const FunctionTypeEffectsRef &Old,
+                                 const FunctionTypeEffectsRef &New);
 
-  static FunctionTypeEffectSet getUnion(ArrayRef<CondFunctionEffect> LHS,
-                                        ArrayRef<CondFunctionEffect> RHS);
-  static FunctionTypeEffectSet difference(ArrayRef<CondFunctionEffect> LHS,
-                                          ArrayRef<CondFunctionEffect> RHS);
+  static FunctionTypeEffectSet getUnion(FunctionTypeEffectsRef LHS,
+                                        FunctionTypeEffectsRef RHS);
 };
 
 /// Represents a prototype with parameter type info, e.g.
@@ -4687,7 +4727,7 @@ class FunctionProtoType final
           FunctionType::FunctionTypeExtraBitfields,
           FunctionType::FunctionTypeArmAttributes, FunctionType::ExceptionType,
           Expr *, FunctionDecl *, FunctionType::ExtParameterInfo,
-          CondFunctionEffect, Qualifiers> {
+          FunctionEffect, FunctionEffectCondExpr, Qualifiers> {
   friend class ASTContext; // ASTContext creates these.
   friend TrailingObjects;
 
@@ -4718,7 +4758,11 @@ class FunctionProtoType final
   //   an ExtParameterInfo for each of the parameters. Present if and
   //   only if hasExtParameterInfos() is true.
   //
-  // * Optionally, an array of getNumFunctionEffects() CondFunctionEffect.
+  // * Optionally, an array of getNumFunctionEffects() FunctionEffect.
+  //   Present only when getNumFunctionEffects() > 0
+  //
+  // * Optionally, an array of getNumFunctionEffects() FunctionEffectCondExpr.
+  //   Present only when getNumFunctionEffectConditions() > 0.
   //
   // * Optionally a Qualifiers object to represent extra qualifiers that can't
   //   be represented by FunctionTypeBitfields.FastTypeQuals. Present if and
@@ -4778,7 +4822,7 @@ class FunctionProtoType final
     ExceptionSpecInfo ExceptionSpec;
     const ExtParameterInfo *ExtParameterInfos = nullptr;
     SourceLocation EllipsisLoc;
-    FunctionTypeEffects FunctionEffects;
+    FunctionTypeEffectsRef FunctionEffects;
 
     ExtProtoInfo()
         : Variadic(false), HasTrailingReturn(false),
@@ -4796,7 +4840,8 @@ class FunctionProtoType final
 
     bool requiresFunctionProtoTypeExtraBitfields() const {
       return ExceptionSpec.Type == EST_Dynamic ||
-             requiresFunctionProtoTypeArmAttributes() || FunctionEffects;
+             requiresFunctionProtoTypeArmAttributes() ||
+             !FunctionEffects.empty();
     }
 
     bool requiresFunctionProtoTypeArmAttributes() const {
@@ -4844,10 +4889,14 @@ class FunctionProtoType final
     return hasExtParameterInfos() ? getNumParams() : 0;
   }
 
-  unsigned numTrailingObjects(OverloadToken<CondFunctionEffect>) const {
+  unsigned numTrailingObjects(OverloadToken<FunctionEffect>) const {
     return getNumFunctionEffects();
   }
 
+  unsigned numTrailingObjects(OverloadToken<FunctionEffectCondExpr>) const {
+    return getNumFunctionEffectConditions();
+  }
+
   /// Determine whether there are any argument types that
   /// contain an unexpanded parameter pack.
   static bool containsAnyUnexpandedParameterPack(const QualType *ArgArray,
@@ -5168,12 +5217,51 @@ class FunctionProtoType final
                : 0;
   }
 
-  FunctionTypeEffects getFunctionEffects() const {
+  // For serialization.
+  ArrayRef<FunctionEffect> getFunctionEffectsOnly() const {
     if (hasExtraBitfields()) {
       const auto *Bitfields = getTrailingObjects<FunctionTypeExtraBitfields>();
       if (Bitfields->NumFunctionEffects > 0)
-        return FunctionTypeEffects({getTrailingObjects<CondFunctionEffect>(),
-                                    Bitfields->NumFunctionEffects});
+        return {getTrailingObjects<FunctionEffect>(),
+                Bitfields->NumFunctionEffects};
+    }
+    return {};
+  }
+
+  unsigned getNumFunctionEffectConditions() const {
+    if (hasExtraBitfields()) {
+      const auto *Bitfields = getTrailingObjects<FunctionTypeExtraBitfields>();
+      if (Bitfields->EffectsHaveConditions)
+        return Bitfields->NumFunctionEffects;
+    }
+    return 0;
+  }
+
+  // For serialization.
+  ArrayRef<FunctionEffectCondExpr> getFunctionEffectConditions() const {
+    if (hasExtraBitfields()) {
+      const auto *Bitfields = getTrailingObjects<FunctionTypeExtraBitfields>();
+      if (Bitfields->EffectsHaveConditions)
+        return {getTrailingObjects<FunctionEffectCondExpr>(),
+                Bitfields->NumFunctionEffects};
+    }
+    return {};
+  }
+
+  // Combines effects with their conditions.
+  FunctionTypeEffectsRef getFunctionEffects() const {
+    if (hasExtraBitfields()) {
+      const auto *Bitfields = getTrailingObjects<FunctionTypeExtraBitfields>();
+      if (Bitfields->NumFunctionEffects > 0) {
+        const size_t NumConds = Bitfields->EffectsHaveConditions
+                                    ? Bitfields->NumFunctionEffects
+                                    : 0;
+        return FunctionTypeEffectsRef(
+            {getTrailingObjects<FunctionEffect>(),
+             Bitfields->NumFunctionEffects},
+            {NumConds ? getTrailingObjects<FunctionEffectCondExpr>() : nullptr,
+             NumConds});
+      }
     }
     return {};
   }
diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
index 6d8cb8b1c2a6d0..b21b031f9c477f 100644
--- a/clang/include/clang/AST/TypeProperties.td
+++ b/clang/include/clang/AST/TypeProperties.td
@@ -352,8 +352,11 @@ let Class = FunctionProtoType in {
   def : Property<"AArch64SMEAttributes", UInt32> {
     let Read = [{ node->getAArch64SMEAttributes() }];
   }
-  def : Property<"functionEffects", Array<CondFunctionEffect>> {
-    let Read = [{ node->getFunctionEffects() }];
+  def : Property<"functionEffects", Array<FunctionEffect>> {
+    let Read = [{ node->getFunctionEffectsOnly() }];
+  }
+  def : Property<"functionEffectConds", Array<FunctionEffectCondExpr>> {
+    let Read = [{ node->getFunctionEffectConditions() }];
   }
 
   def : Creator<[{
@@ -371,7 +374,7 @@ let Class = FunctionProtoType in {
     epi.ExtParameterInfos =
       extParameterInfo.empty() ? nullptr : extParameterInfo.data();
     epi.AArch64SMEAttributes = AArch64SMEAttributes;
-    epi.FunctionEffects = FunctionTypeEffects(functionEffects);
+    epi.FunctionEffects = FunctionTypeEffectsRef(functionEffects, functionEffectConds);
     return ctx.getFunctionType(returnType, parameters, epi);
   }]>;
 }
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 5951f44004d925..ff11b4f6b4d0f0 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -943,7 +943,7 @@ class Sema final {
   // out of Type.h, but where to?
 
   /// All functions/lambdas/blocks which have bodies and which have a non-empty
-  /// FunctionTypeEffects to be verified.
+  /// FunctionTypeEffectsRef to be verified.
   SmallVector<const Decl *> DeclsWithEffectsToVerify;
   /// The union of all effects present on DeclsWithEffectsToVerify. Conditions
   /// are all null.
@@ -954,7 +954,7 @@ class Sema final {
                                         SourceLocation Loc);
 
   /// Potentially add a FunctionDecl or BlockDecl to DeclsWithEffectsToVerify.
-  void maybeAddDeclWithEffects(const Decl *D, const FunctionTypeEffects &FX);
+  void maybeAddDeclWithEffects(const Decl *D, const FunctionTypeEffectsRef &FX);
 
   // ----- function effects --- where ?????
 
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 2893cd692f3eea..5d513f6e6b3d2f 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -4563,11 +4563,12 @@ QualType ASTContext::getFunctionTypeInternal(
       QualType, SourceLocation, FunctionType::FunctionTypeExtraBitfields,
       FunctionType::FunctionTypeArmAttributes, FunctionType::ExceptionType,
       Expr *, FunctionDecl *, FunctionProtoType::ExtParameterInfo,
-      CondFunctionEffect, Qualifiers>(
+      FunctionEffect, FunctionEffectCondExpr, Qualifiers>(
       NumArgs, EPI.Variadic, EPI.requiresFunctionProtoTypeExtraBitfields(),
       EPI.requiresFunctionProtoTypeArmAttributes(), ESH.NumExceptionType,
       ESH.NumExprPtr, ESH.NumFunctionDeclPtr,
       EPI.ExtParameterInfos ? NumArgs : 0, EPI.FunctionEffects.size(),
+      EPI.FunctionEffects.conditions().size(),
       EPI.TypeQuals.hasNonFastQualifiers() ? 1 : 0);
 
   auto *FTP = (FunctionProtoType *)Allocate(Size, alignof(FunctionProtoType));
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index f57f60b2cab993..740542b3767191 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -4508,7 +4508,7 @@ unsigned FunctionDecl::getODRHash() {
 // Effects may differ between declarations, but they should be propagated from
 // old to new on any redeclaration, so it suffices to look at
 // getMostRecentDecl().
-FunctionTypeEffects FunctionDecl::getFunctionEffects() const {
+FunctionTypeEffectsRef FunctionDecl::getFunctionEffects() const {
   if (const auto *FPT =
           getMostRecentDecl()->getType()->getAs<FunctionProtoType>()) {
     return FPT->getFunctionEffects();
@@ -5240,7 +5240,7 @@ SourceRange BlockDecl::getSourceRange() const {
   return SourceRange(getLocation(), Body ? Body->getEndLoc() : getLocation());
 }
 
-FunctionTypeEffects BlockDecl::getFunctionEffects() const {
+FunctionTypeEffectsRef BlockDecl::getFunctionEffects() const {
   if (auto *TSI = getSignatureAsWritten()) {
     if (auto *FPT = TSI->getType()->getAs<FunctionProtoType>()) {
       return FPT->getFunctionEffects();
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 069febb3e71e5b..d9df0f3acf9aa4 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3638,13 +3638,20 @@ FunctionProtoType::FunctionProtoType(QualType result, ArrayRef<QualType> params,
     EllipsisLoc = epi.EllipsisLoc;
   }
 
-  if (epi.FunctionEffects) {
+  if (!epi.FunctionEffects.empty()) {
     auto &ExtraBits = *getTrailingObjects<FunctionTypeExtraBitfields>();
     // TODO: bitfield overflow?
-    if (epi.FunctionEffects) {
-      ExtraBits.NumFunctionEffects = epi.FunctionEffects.size();
-      CondFunctionEffect *CFE = getTrailingObjects<CondFunctionEffect>();
-      std::copy(epi.FunctionEffects.begin(), epi.FunctionEffects.end(), CFE);
+    ExtraBits.NumFunctionEffects = epi.FunctionEffects.size();
+
+    ArrayRef<FunctionEffect> SrcFX = epi.FunctionEffects.effects();
+    auto *DestFX = getTrailingObjects<FunctionEffect>();
+    std::copy(SrcFX.begin(), SrcFX.end(), DestFX);
+
+    ArrayRef<FunctionEffectCondExpr> SrcConds =
+        epi.FunctionEffects.conditions();
+    if (!SrcConds.empty()) {
+      auto *DestConds = getTrailingObjects<FunctionEffectCondExpr>();
+      std::copy(SrcConds.begin(), SrcConds.end(), DestConds);
     }
   }
 }
@@ -5043,8 +5050,8 @@ StringRef FunctionEffect::name() const {
 }
 
 bool FunctionEffect::shouldDiagnoseConversion(
-    bool Adding, QualType OldType, const FunctionTypeEffects &OldFX,
-    QualType NewType, const FunctionTypeEffects &NewFX) const {
+    bool Adding, QualType OldType, const FunctionTypeEffectsRef &OldFX,
+    QualType NewType, const FunctionTypeEffectsRef &NewFX) const {
 
   switch (kind()) {
   case Kind::NonAllocating:
@@ -5052,7 +5059,7 @@ bool FunctionEffect::shouldDiagnoseConversion(
     // have nonblocking
     if (Adding) {
       for (const auto &CFE : OldFX) {
-        if (CFE.effect().kind() == Kind::NonBlocking)
+        if (CFE.Effect.kind() == Kind::NonBlocking)
           return false;
       }
     }
@@ -5068,8 +5075,8 @@ bool FunctionEffect::shouldDiagnoseConversion(
 
 bool FunctionEffect::shouldDiagnoseRedeclaration(
     bool Adding, const FunctionDecl &OldFunction,
-    const FunctionTypeEffects &OldFX, const FunctionDecl &NewFunction,
-    const FunctionTypeEffects &NewFX) const {
+    const FunctionTypeEffectsRef &OldFX, const FunctionDecl &NewFunction,
+    const FunctionTypeEffectsRef &NewFX) const {
   switch (kind()) {
   case Kind::NonAllocating:
   case Kind::NonBlocking:
@@ -5084,8 +5091,8 @@ bool FunctionEffect::shouldDiagnoseRedeclaration(
 
 FunctionEffect::OverrideResult FunctionEffect::shouldDiagnoseMethodOverride(
     bool Adding, const CXXMethodDecl &OldMethod,
-    const FunctionTypeEffects &OldFX, const CXXMethodDecl &NewMethod,
-    const FunctionTypeEffects &NewFX) const {
+    const FunctionTypeEffectsRef &OldFX, const CXXMethodDecl &NewMethod,
+    const FunctionTypeEffectsRef &NewFX) const {
   switch (kind()) {
   case Kind::NonAllocating:
   case Kind::NonBlocking:
@@ -5156,65 +5163,125 @@ bool FunctionEffect::shouldDiagnoseFunctionCall(
 
 // =====
 
-void FunctionTypeEffects::Profile(llvm::FoldingSetNodeID &ID) const {
-  ID.AddInteger(size());
-  for (const auto &CFE : Items) {
-    ID.AddInteger(llvm::to_underlying(CFE.effect().kind()));
-    ID.AddPointer(CFE.condition());
+void FunctionTypeEffectsRef::Profile(llvm::FoldingSetNodeID &ID) const {
+  const bool HasConds = !Conditions.empty();
+
+  ID.AddInteger(size() | (HasConds << 31u));
+  for (unsigned Idx = 0, Count = Effects.size(); Idx != Count; ++Idx) {
+    ID.AddInteger(llvm::to_underlying(Effects[Idx].kind()));
+    if (HasConds)
+      ID.AddPointer(Conditions[Idx].Cond);
   }
 }
 
+void FunctionTypeEffectSet::insert(FunctionEffect Effect, const Expr *Cond) {
+  // lower_bound would be overkill
+  unsigned Idx = 0;
+  for (unsigned Count = Effects.size(); Idx != Count; ++Idx) {
+    const auto &IterEffect = Effects[Idx];
+    if (IterEffect == Effect) {
+      // TODO: Is it okay to assume the caller has already diagnosed
+      // any potential conflict with conditions here?
+      return;
+    }
+    if (Effect < IterEffect)
+      break;
+  }
+
+  if (Cond != nullptr) {
+    if (Conditions.empty() && !Effects.empty())
+      Conditions.resize(Effects.size());
+    Conditions.insert(Conditions.begin() + Idx, FunctionEffectCondExpr{Cond});
+  }
+  Effects.insert(Effects.begin() + Idx, Effect);
+}
+
+void FunctionTypeEffectSet::insert(const FunctionTypeEffectsRef &Set) {
+  for (const auto &Item : Set)
+    insert(Item.Effect, Item.Cond);
+}
+
+void FunctionTypeEffectSet::insertIgnoringConditions(
+    const FunctionTypeEffectsRef &Set) {
+  for (const auto &Item : Set)
+    insert(Item.Effect, nullptr);
+}
+
 FunctionTypeEffectSet
-FunctionTypeEffectSet::getUnion(ArrayRef<CondFunctionEffect> LHS,
-                                ArrayRef<CondFunctionEffect> RHS) {
+FunctionTypeEffectSet::getUnion(FunctionTypeEffectsRef LHS,
+                                FunctionTypeEffectsRef RHS) {
   // Optimize for either of the two sets being empty (very common).
   if (LHS.empty())
     return FunctionTypeEffectSet(RHS);
-  if (RHS.empty())
-    return FunctionTypeEffectSet(LHS);
-
-  // Optimize for the two sets being identical (very common).
-  if (LHS == RHS)
-    return FunctionTypeEffectSet(LHS);
 
-  FunctionTypeEffectSet Result;
-  Result.Impl.reserve(LHS.size() + RHS.size());
-  std::set_union(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
-                 std::back_inserter(Result.Impl));
+  FunctionTypeEffectSet Result(LHS);
+  Result.insert(RHS);
   return Result;
 }
 
 FunctionTypeEffectSet::Differences
-FunctionTypeEffectSet::differences(const FunctionTypeEffects &Old,
-                                   const FunctionTypeEffects &New) {
-  // TODO: Could be a one-pass algorithm.
-  Differences Result;
-  for (const auto &Effect : FunctionTypeEffectSet::difference(New, Old)) {
-    Result.emplace_back(Effect, true);
-  }
-  for (const auto &Effect : FunctionTypeEffectSet::difference(Old, New)) {
-    Result.emplace_back(Effect, false);
+FunctionTypeEffectSet::differences(const FunctionTypeEffectsRef &Old,
+                                   const FunctionTypeEffectsRef &New) {
+
+  FunctionTypeEffectSet::Differences Result;
+
+  FunctionTypeEffectsRef::iterator POld = Old.begin();
+  FunctionTypeEffectsRef::iterator OldEnd = Old.end();
+  FunctionTypeEffectsRef::iterator PNew = New.begin();
+  FunctionTypeEffectsRef::iterator NewEnd = New.end();
+
+  auto compare = [](const CondFunctionEffect &LHS,
+                    const CondFunctionEffect &RHS) {
+    if (LHS.Effect < RHS.Effect)
+      return -1;
+    if (LHS.Effect > RHS.Effect)
+      return 1;
+    if (LHS.Cond < RHS.Cond)
+      return -1;
+    if (LHS.Cond > RHS.Cond)
+      return 1;
+    return 0;
+  };
+
+  while (true) {
+    int cmp = 0;
+    if (POld == OldEnd) {
+      if (PNew == NewEnd)
+        break;
+      cmp = 1;
+    } else if (PNew == NewEnd)
+      cmp = -1;
+    else
+      cmp = compare(*POld, *PNew);
+
+    if (cmp < 0) {
+      // removal
+      Result.push_back({*POld, false});
+      ++POld;
+    } else if (cmp > 0) {
+      // addition
+      Result.push_back({*PNew, true});
+      ++PNew;
+    } else {
+      ++POld;
+      ++PNew;
+    }
   }
+
   return Result;
 }
 
+#if 0
 FunctionTypeEffectSet
-FunctionTypeEffectSet::difference(ArrayRef<CondFunctionEffect> LHS,
-                                  ArrayRef<CondFunctionEffect> RHS) {
+FunctionTypeEffectSet::difference(FunctionTypeEffectsRef LHS,
+                                  FunctionTypeEffectsRef RHS) {
   FunctionTypeEffectSet Result;
   std::set_difference(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
                       std::back_inserter(Result.Impl));
   return Result;
 }
 
-void FunctionTypeEffectSet::insert(const CondFunctionEffect &Effect) {
-  auto *Iter = std::lower_bound(Impl.begin(), Impl.end(), Effect);
-  if (Iter == Impl.end() || *Iter != Effect) {
-    Impl.insert(Iter, Effect);
-  }
-}
-
-void FunctionTypeEffectSet::insert(ArrayRef<CondFunctionEffect> Arr) {
+void FunctionTypeEffectSet::insert(FunctionTypeEffectsRef Arr) {
   // TODO: For large RHS sets, use set_union or a custom insert-in-place
   for (const auto &CFE : Arr) {
     insert(CFE);
@@ -5222,14 +5289,16 @@ void FunctionTypeEffectSet::insert(ArrayRef<CondFunctionEffect> Arr) {
 }
 
 void FunctionTypeEffectSet::insertIgnoringConditions(
-    ArrayRef<CondFunctionEffect> Arr) {
+    FunctionTypeEffectsRef Arr) {
   // TODO: For large RHS sets, use set_union or a custom insert-in-place
   for (const auto &CFE : Arr) {
     insert(CondFunctionEffect(CFE.effect().kind(), nullptr));
   }
 }
+#endif
 
-LLVM_DUMP_METHOD void FunctionTypeEffects::dump(llvm::raw_ostream &OS) const {
+LLVM_DUMP_METHOD void
+FunctionTypeEffectsRef::dump(llvm::raw_ostream &OS) const {
   OS << "Effects{";
   bool First = true;
   for (const auto &CFE : *this) {
@@ -5237,17 +5306,18 @@ LLVM_DUMP_METHOD void FunctionTypeEffects::dump(llvm::raw_ostream &OS) const {
       OS << ", ";
     else
       First = false;
-    OS << CFE.effect().name();
+    OS << CFE.Effect.name();
+    // TODO: Condition
   }
   OS << "}";
 }
 
 LLVM_DUMP_METHOD void FunctionTypeEffectSet::dump(llvm::raw_ostream &OS) const {
-  FunctionTypeEffects(*this).dump(OS);
+  FunctionTypeEffectsRef(*this).dump(OS);
 }
 
 // TODO: inline?
-FunctionTypeEffects FunctionTypeEffects::get(QualType QT) {
+FunctionTypeEffectsRef FunctionTypeEffectsRef::get(QualType QT) {
   if (QT->isReferenceType())
     QT = QT.getNonReferenceType();
   if (QT->isPointerType())
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 054aa3de413c83..01708bb85b5fea 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -998,9 +998,9 @@ void TypePrinter::printFunctionProtoAfter(const FunctionProtoType *T,
   }
   T->printExceptionSpecification(OS, Policy);
 
-  const FunctionTypeEffects FX = T->getFunctionEffects();
+  const FunctionTypeEffectsRef FX = T->getFunctionEffects();
   for (const auto &CFE : FX)
-    OS << " __attribute__((clang_" << CFE.effect().name() << "))";
+    OS << " __attribute__((clang_" << CFE.Effect.name() << "))";
   // $$$ TODO: Conditions ???
 
   if (T->hasTrailingReturn()) {
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index dacabfa8f32a67..482358839767b0 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2527,7 +2527,7 @@ class FunctionEffectSet {
 
   void insert(const FunctionEffect &Effect);
   void insert(const FunctionEffectSet &Set);
-  void insertIgnoringConditions(ArrayRef<CondFunctionEffect> Arr);
+  void insertIgnoringConditions(const FunctionTypeEffectsRef &FX);
 
   void dump(llvm::raw_ostream &OS) const;
 
@@ -2554,9 +2554,9 @@ void FunctionEffectSet::insert(const FunctionEffectSet &Set) {
 }
 
 void FunctionEffectSet::insertIgnoringConditions(
-    ArrayRef<CondFunctionEffect> Arr) {
-  for (auto &Item : Arr)
-    insert(Item.effect());
+    const FunctionTypeEffectsRef &FX) {
+  for (const auto &Item : FX)
+    insert(Item.Effect);
 }
 
 LLVM_DUMP_METHOD void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
@@ -2594,7 +2594,7 @@ struct CallableInfo {
   CallableInfo(const Decl &CD, SpecialFuncType FT = SpecialFuncType::None)
       : CDecl(&CD), FuncType(FT) {
     // llvm::errs() << "CallableInfo " << name() << "\n";
-    FunctionTypeEffects FX;
+    FunctionTypeEffectsRef FX;
 
     if (auto *FD = dyn_cast<FunctionDecl>(CDecl)) {
       // Use the function's definition, if any.
@@ -2613,7 +2613,7 @@ struct CallableInfo {
       FX = BD->getFunctionEffects();
     } else if (auto *VD = dyn_cast<ValueDecl>(CDecl)) {
       // ValueDecl is function, enum, or variable, so just look at its type.
-      FX = FunctionTypeEffects::get(VD->getType());
+      FX = FunctionTypeEffectsRef::get(VD->getType());
     }
     Effects.insertIgnoringConditions(FX);
   }
@@ -2967,7 +2967,7 @@ class Analyzer {
     // be checked, and to see which ones are inferrable.
     {
       for (const CondFunctionEffect &CFE : Sem.AllEffectsToVerify) {
-        const FunctionEffect &Effect = CFE.effect();
+        const FunctionEffect &Effect = CFE.Effect;
         const auto Flags = Effect.flags();
         if (Flags & FunctionEffect::FE_InferrableOnCallees) {
           AllInferrableEffectsToVerify.insert(Effect);
@@ -3718,14 +3718,14 @@ class Analyzer {
 
     void run(const MatchFinder::MatchResult &Result) override {
       if (auto *Callable = Result.Nodes.getNodeAs<Decl>(Tag_Callable)) {
-        if (const auto FX = functionEffectsForDecl(Callable)) {
+        if (const auto FX = functionEffectsForDecl(Callable); !FX.empty()) {
           // Reuse this filtering method in Sema
           Sem.maybeAddDeclWithEffects(Callable, FX);
         }
       }
     }
 
-    static FunctionTypeEffects functionEffectsForDecl(const Decl *D) {
+    static FunctionTypeEffectsRef functionEffectsForDecl(const Decl *D) {
       if (auto *FD = D->getAsFunction()) {
         return FD->getFunctionEffects();
       }
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index fdef8dc9f877f3..b0cbdedbc2875b 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -590,11 +590,11 @@ void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
 // Generate diagnostics when adding or removing effects in a type conversion.
 void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
                                             SourceLocation Loc) {
-  const auto SrcFX = FunctionTypeEffects::get(SrcType);
-  const auto DstFX = FunctionTypeEffects::get(DstType);
+  const auto SrcFX = FunctionTypeEffectsRef::get(SrcType);
+  const auto DstFX = FunctionTypeEffectsRef::get(DstType);
   if (SrcFX != DstFX) {
     for (const auto &Item : FunctionTypeEffectSet::differences(SrcFX, DstFX)) {
-      const FunctionEffect &Effect = Item.first.effect();
+      const FunctionEffect &Effect = Item.first.Effect;
       const bool Adding = Item.second;
       if (Effect.shouldDiagnoseConversion(Adding, SrcType, SrcFX, DstType,
                                           DstFX)) {
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 1a48d759e3a8ec..17aec3f57ac970 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3926,7 +3926,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
   if (OldFX != NewFX) {
     const auto Diffs = FunctionTypeEffectSet::differences(OldFX, NewFX);
     for (const auto &Item : Diffs) {
-      const FunctionEffect &Effect = Item.first.effect();
+      const FunctionEffect &Effect = Item.first.Effect;
       const bool Adding = Item.second;
       if (Effect.shouldDiagnoseRedeclaration(Adding, *Old, OldFX, *New,
                                              NewFX)) {
@@ -3943,7 +3943,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
       auto MergedFX = FunctionTypeEffectSet::getUnion(OldFX, NewFX);
 
       FunctionProtoType::ExtProtoInfo EPI = NewFPT->getExtProtoInfo();
-      EPI.FunctionEffects = FunctionTypeEffects(MergedFX);
+      EPI.FunctionEffects = FunctionTypeEffectsRef(MergedFX);
       QualType ModQT = Context.getFunctionType(NewFPT->getReturnType(),
                                                NewFPT->getParamTypes(), EPI);
 
@@ -3954,7 +3954,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
       // so as not to fail due to differences later.
       if (const auto *OldFPT = OldQType->getAs<FunctionProtoType>()) {
         EPI = OldFPT->getExtProtoInfo();
-        EPI.FunctionEffects = FunctionTypeEffects(MergedFX);
+        EPI.FunctionEffects = FunctionTypeEffectsRef(MergedFX);
         OldQTypeForComparison = Context.getFunctionType(
             OldFPT->getReturnType(), OldFPT->getParamTypes(), EPI);
       }
@@ -11129,7 +11129,7 @@ Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
 // Should only be called when getFunctionEffects() returns a non-empty set.
 // Decl should be a FunctionDecl or BlockDecl.
 void Sema::maybeAddDeclWithEffects(const Decl *D,
-                                   const FunctionTypeEffects &FX) {
+                                   const FunctionTypeEffectsRef &FX) {
   if (!D->hasBody()) {
     if (const auto *FD = D->getAsFunction()) {
       if (!FD->willHaveBody()) {
@@ -16065,7 +16065,8 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
       getCurLexicalContext()->getDeclKind() != Decl::ObjCImplementation)
     Diag(FD->getLocation(), diag::warn_function_def_in_objc_container);
 
-  if (const auto FX = FD->getCanonicalDecl()->getFunctionEffects()) {
+  if (const auto FX = FD->getCanonicalDecl()->getFunctionEffects();
+      !FX.empty()) {
     maybeAddDeclWithEffects(FD, FX);
   }
 
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 4c5e47c66ee5b3..fb4850fefe8c97 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18333,7 +18333,7 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
     bool AnyDiags = false;
 
     for (const auto &Item : Diffs) {
-      const FunctionEffect &Effect = Item.first.effect();
+      const FunctionEffect &Effect = Item.first.Effect;
       const bool Adding = Item.second;
       switch (Effect.shouldDiagnoseMethodOverride(Adding, *Old, OldFX, *New,
                                                   NewFX)) {
@@ -18350,7 +18350,7 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
         auto MergedFX = FunctionTypeEffectSet::getUnion(OldFX, NewFX);
 
         FunctionProtoType::ExtProtoInfo EPI = NewFT->getExtProtoInfo();
-        EPI.FunctionEffects = FunctionTypeEffects(MergedFX);
+        EPI.FunctionEffects = FunctionTypeEffectsRef(MergedFX);
         QualType ModQT = Context.getFunctionType(NewFT->getReturnType(),
                                                  NewFT->getParamTypes(), EPI);
         New->setType(ModQT);
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index d5cfc4669c9ab9..a386bd11e9be92 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -17156,7 +17156,7 @@ ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc,
   BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back());
   BlockDecl *BD = BSI->TheDecl;
 
-  if (const auto FX = BD->getFunctionEffects()) {
+  if (const auto FX = BD->getFunctionEffects(); !FX.empty()) {
     maybeAddDeclWithEffects(BD, FX);
   }
 
diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index bb6ee041ad9446..c0ff29174c42a7 100644
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -1889,7 +1889,7 @@ ExprResult Sema::ActOnLambdaExpr(SourceLocation StartLoc, Stmt *Body) {
   LambdaScopeInfo LSI = *cast<LambdaScopeInfo>(FunctionScopes.back());
   ActOnFinishFunctionBody(LSI.CallOperator, Body);
 
-  if (const auto FX = LSI.CallOperator->getFunctionEffects()) {
+  if (const auto FX = LSI.CallOperator->getFunctionEffects(); !FX.empty()) {
     maybeAddDeclWithEffects(LSI.CallOperator, FX);
   }
 
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 542853050bae41..68fe306cf326e4 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8116,16 +8116,16 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
   }
 
   // nonblocking(true) and nonallocating(true) are represented as
-  // FunctionEffects, in a FunctionTypeEffects attached to a FunctionProtoType.
-  const CondFunctionEffect NewEffect(isNonBlocking
-                                         ? FunctionEffect::Kind::NonBlocking
-                                         : FunctionEffect::Kind::NonAllocating,
-                                     nullptr /* no condition yet */);
+  // FunctionEffects, in a FunctionTypeEffectsRef attached to a
+  // FunctionProtoType.
+  const FunctionEffect NewEffect(isNonBlocking
+                                     ? FunctionEffect::Kind::NonBlocking
+                                     : FunctionEffect::Kind::NonAllocating);
 
   FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
   FunctionTypeEffectSet FX(EPI.FunctionEffects);
-  FX.insert(NewEffect);
-  EPI.FunctionEffects = FunctionTypeEffects(FX);
+  FX.insert(NewEffect, nullptr);
+  EPI.FunctionEffects = FunctionTypeEffectsRef(FX);
 
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
                                                FPT->getParamTypes(), EPI);
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index d4bd45f3b7434b..7d6fc9d03f4c10 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -8226,13 +8226,13 @@ void ASTReader::InitializeSema(Sema &S) {
       Decl *D = GetDecl(ID);
       SemaObj->DeclsWithEffectsToVerify.push_back(D);
 
-      FunctionTypeEffects FX;
+      FunctionTypeEffectsRef FX;
       if (auto *FD = dyn_cast<FunctionDecl>(D)) {
         FX = FD->getFunctionEffects();
       } else if (auto *BD = dyn_cast<BlockDecl>(D)) {
         FX = BD->getFunctionEffects();
       }
-      if (FX) {
+      if (!FX.empty()) {
         SemaObj->AllEffectsToVerify.insertIgnoringConditions(FX);
       }
     }

>From 57d09cefde0124d67008528fca9d21d260cd2f44 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 16 Apr 2024 07:39:36 -0700
Subject: [PATCH 33/40] FunctionEffectCondExpr => FunctionEffectCondition

---
 clang/include/clang/AST/AbstractBasicReader.h |  4 +--
 clang/include/clang/AST/AbstractBasicWriter.h |  2 +-
 clang/include/clang/AST/PropertiesBase.td     |  2 +-
 clang/include/clang/AST/Type.h                | 30 +++++++++----------
 clang/include/clang/AST/TypeProperties.td     |  2 +-
 clang/lib/AST/ASTContext.cpp                  |  2 +-
 clang/lib/AST/Type.cpp                        |  6 ++--
 7 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/clang/include/clang/AST/AbstractBasicReader.h b/clang/include/clang/AST/AbstractBasicReader.h
index f932b7608d474b..f3418222780197 100644
--- a/clang/include/clang/AST/AbstractBasicReader.h
+++ b/clang/include/clang/AST/AbstractBasicReader.h
@@ -251,8 +251,8 @@ class DataStreamBasicReader : public BasicReaderBase<Impl> {
     return FunctionEffect(static_cast<FunctionEffect::Kind>(value));
   }
 
-  FunctionEffectCondExpr readFunctionEffectCondExpr() {
-    return FunctionEffectCondExpr{asImpl().readExprRef()};
+  FunctionEffectCondition readFunctionEffectCondition() {
+    return FunctionEffectCondition{asImpl().readExprRef()};
   }
 
   NestedNameSpecifier *readNestedNameSpecifier() {
diff --git a/clang/include/clang/AST/AbstractBasicWriter.h b/clang/include/clang/AST/AbstractBasicWriter.h
index 51dc280efcd9cd..c269d3f7ed9c31 100644
--- a/clang/include/clang/AST/AbstractBasicWriter.h
+++ b/clang/include/clang/AST/AbstractBasicWriter.h
@@ -228,7 +228,7 @@ class DataStreamBasicWriter : public BasicWriterBase<Impl> {
     asImpl().writeUInt32(llvm::to_underlying(E.kind()));
   }
 
-  void writeFunctionEffectCondExpr(FunctionEffectCondExpr CE) {
+  void writeFunctionEffectCondition(FunctionEffectCondition CE) {
     asImpl().writeExprRef(CE.Cond);
   }
 
diff --git a/clang/include/clang/AST/PropertiesBase.td b/clang/include/clang/AST/PropertiesBase.td
index b596b22d943296..aa25a1c7c3acf5 100644
--- a/clang/include/clang/AST/PropertiesBase.td
+++ b/clang/include/clang/AST/PropertiesBase.td
@@ -118,7 +118,7 @@ def FixedPointSemantics : PropertyType<"llvm::FixedPointSemantics"> {
   let PassByReference = 1;
 }
 def FunctionEffect : PropertyType<"FunctionEffect">;
-def FunctionEffectCondExpr : PropertyType<"FunctionEffectCondExpr">;
+def FunctionEffectCondition : PropertyType<"FunctionEffectCondition">;
 def Identifier : RefPropertyType<"IdentifierInfo"> { let ConstWhenWriting = 1; }
 def LValuePathEntry : PropertyType<"APValue::LValuePathEntry">;
 def LValuePathSerializationHelper :
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index dad5eacbaea6bb..008eb2d177e945 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4447,9 +4447,9 @@ class FunctionTypeEffectSet;
 
   - Keep FunctionEffect itself here but make it more minimal. Don't define flags
   or any behaviors, just the Kind and an accessor.
-  - Keep FunctionEffectCondExpr here.
+  - Keep FunctionEffectCondition here.
   - Make FunctionProtoType and ExtProtoInfo use only ArrayRef<FunctionEffect>
-  and ArrayRef<FunctionEffectCondExpr>.
+  and ArrayRef<FunctionEffectCondition>.
   - Somewhere in Sema, define ExtFunctionEffect, which holds a FunctionEffect
     and has all the behavior-related methods.
   - There too, define the containers. FunctionTypeEffectsRef can have a
@@ -4578,10 +4578,10 @@ class FunctionEffect {
 
 /// Wrap a function effect's condition expression in another struct so
 /// that FunctionProtoType's TrailingObjects can treat it separately.
-struct FunctionEffectCondExpr {
+struct FunctionEffectCondition {
   const Expr *Cond = nullptr; // if null, unconditional
 
-  bool operator==(const FunctionEffectCondExpr &RHS) const {
+  bool operator==(const FunctionEffectCondition &RHS) const {
     return Cond == RHS.Cond;
   }
 };
@@ -4595,7 +4595,7 @@ struct CondFunctionEffect {
 };
 
 /// Support iteration in parallel through a pair of FunctionEffect and
-/// FunctionEffectCondExpr containers.
+/// FunctionEffectCondition containers.
 template <typename Container> class FunctionEffectIterator {
   const Container &Outer;
   size_t Idx;
@@ -4631,7 +4631,7 @@ class FunctionTypeEffectsRef {
 
   // The array of conditions is either empty or has the same size
   // as the array of effects.
-  ArrayRef<FunctionEffectCondExpr> Conditions;
+  ArrayRef<FunctionEffectCondition> Conditions;
 
 public:
   /// Extract the effects from a Type if it is a function, block, or member
@@ -4642,14 +4642,14 @@ class FunctionTypeEffectsRef {
 
   // The arrays are expected to have been sorted by the caller.
   FunctionTypeEffectsRef(ArrayRef<FunctionEffect> FX,
-                         ArrayRef<FunctionEffectCondExpr> Conds)
+                         ArrayRef<FunctionEffectCondition> Conds)
       : Effects(FX), Conditions(Conds) {}
 
   bool empty() const { return Effects.empty(); }
   size_t size() const { return Effects.size(); }
 
   ArrayRef<FunctionEffect> effects() const { return Effects; }
-  ArrayRef<FunctionEffectCondExpr> conditions() const { return Conditions; }
+  ArrayRef<FunctionEffectCondition> conditions() const { return Conditions; }
 
   using iterator = FunctionEffectIterator<FunctionTypeEffectsRef>;
   friend iterator;
@@ -4675,7 +4675,7 @@ class FunctionTypeEffectSet {
   SmallVector<FunctionEffect> Effects;
   // The vector of conditions is either empty or has the same size
   // as the vector of effects.
-  SmallVector<FunctionEffectCondExpr> Conditions;
+  SmallVector<FunctionEffectCondition> Conditions;
 
 public:
   FunctionTypeEffectSet() = default;
@@ -4727,7 +4727,7 @@ class FunctionProtoType final
           FunctionType::FunctionTypeExtraBitfields,
           FunctionType::FunctionTypeArmAttributes, FunctionType::ExceptionType,
           Expr *, FunctionDecl *, FunctionType::ExtParameterInfo,
-          FunctionEffect, FunctionEffectCondExpr, Qualifiers> {
+          FunctionEffect, FunctionEffectCondition, Qualifiers> {
   friend class ASTContext; // ASTContext creates these.
   friend TrailingObjects;
 
@@ -4761,7 +4761,7 @@ class FunctionProtoType final
   // * Optionally, an array of getNumFunctionEffects() FunctionEffect.
   //   Present only when getNumFunctionEffects() > 0
   //
-  // * Optionally, an array of getNumFunctionEffects() FunctionEffectCondExpr.
+  // * Optionally, an array of getNumFunctionEffects() FunctionEffectCondition.
   //   Present only when getNumFunctionEffectConditions() > 0.
   //
   // * Optionally a Qualifiers object to represent extra qualifiers that can't
@@ -4893,7 +4893,7 @@ class FunctionProtoType final
     return getNumFunctionEffects();
   }
 
-  unsigned numTrailingObjects(OverloadToken<FunctionEffectCondExpr>) const {
+  unsigned numTrailingObjects(OverloadToken<FunctionEffectCondition>) const {
     return getNumFunctionEffectConditions();
   }
 
@@ -5238,11 +5238,11 @@ class FunctionProtoType final
   }
 
   // For serialization.
-  ArrayRef<FunctionEffectCondExpr> getFunctionEffectConditions() const {
+  ArrayRef<FunctionEffectCondition> getFunctionEffectConditions() const {
     if (hasExtraBitfields()) {
       const auto *Bitfields = getTrailingObjects<FunctionTypeExtraBitfields>();
       if (Bitfields->EffectsHaveConditions)
-        return {getTrailingObjects<FunctionEffectCondExpr>(),
+        return {getTrailingObjects<FunctionEffectCondition>(),
                 Bitfields->NumFunctionEffects};
     }
     return {};
@@ -5259,7 +5259,7 @@ class FunctionProtoType final
         return FunctionTypeEffectsRef(
             {getTrailingObjects<FunctionEffect>(),
              Bitfields->NumFunctionEffects},
-            {NumConds ? getTrailingObjects<FunctionEffectCondExpr>() : nullptr,
+            {NumConds ? getTrailingObjects<FunctionEffectCondition>() : nullptr,
              NumConds});
       }
     }
diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
index b21b031f9c477f..0cbbdbd2911eaf 100644
--- a/clang/include/clang/AST/TypeProperties.td
+++ b/clang/include/clang/AST/TypeProperties.td
@@ -355,7 +355,7 @@ let Class = FunctionProtoType in {
   def : Property<"functionEffects", Array<FunctionEffect>> {
     let Read = [{ node->getFunctionEffectsOnly() }];
   }
-  def : Property<"functionEffectConds", Array<FunctionEffectCondExpr>> {
+  def : Property<"functionEffectConds", Array<FunctionEffectCondition>> {
     let Read = [{ node->getFunctionEffectConditions() }];
   }
 
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 5d513f6e6b3d2f..cd0e1dcc01e88f 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -4563,7 +4563,7 @@ QualType ASTContext::getFunctionTypeInternal(
       QualType, SourceLocation, FunctionType::FunctionTypeExtraBitfields,
       FunctionType::FunctionTypeArmAttributes, FunctionType::ExceptionType,
       Expr *, FunctionDecl *, FunctionProtoType::ExtParameterInfo,
-      FunctionEffect, FunctionEffectCondExpr, Qualifiers>(
+      FunctionEffect, FunctionEffectCondition, Qualifiers>(
       NumArgs, EPI.Variadic, EPI.requiresFunctionProtoTypeExtraBitfields(),
       EPI.requiresFunctionProtoTypeArmAttributes(), ESH.NumExceptionType,
       ESH.NumExprPtr, ESH.NumFunctionDeclPtr,
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index d9df0f3acf9aa4..2c21db8ff46e73 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3647,10 +3647,10 @@ FunctionProtoType::FunctionProtoType(QualType result, ArrayRef<QualType> params,
     auto *DestFX = getTrailingObjects<FunctionEffect>();
     std::copy(SrcFX.begin(), SrcFX.end(), DestFX);
 
-    ArrayRef<FunctionEffectCondExpr> SrcConds =
+    ArrayRef<FunctionEffectCondition> SrcConds =
         epi.FunctionEffects.conditions();
     if (!SrcConds.empty()) {
-      auto *DestConds = getTrailingObjects<FunctionEffectCondExpr>();
+      auto *DestConds = getTrailingObjects<FunctionEffectCondition>();
       std::copy(SrcConds.begin(), SrcConds.end(), DestConds);
     }
   }
@@ -5191,7 +5191,7 @@ void FunctionTypeEffectSet::insert(FunctionEffect Effect, const Expr *Cond) {
   if (Cond != nullptr) {
     if (Conditions.empty() && !Effects.empty())
       Conditions.resize(Effects.size());
-    Conditions.insert(Conditions.begin() + Idx, FunctionEffectCondExpr{Cond});
+    Conditions.insert(Conditions.begin() + Idx, FunctionEffectCondition{Cond});
   }
   Effects.insert(Effects.begin() + Idx, Effect);
 }

>From a9edec6b6b69c5189fd547a788d1c256688849ba Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 16 Apr 2024 07:47:44 -0700
Subject: [PATCH 34/40] FunctionTypeEffectSet => FunctionEffectSet
 FunctionTypeEffectsRef => FunctionEffectsRef

---
 clang/include/clang/AST/Decl.h            |  4 +-
 clang/include/clang/AST/Type.h            | 68 +++++++++++-----------
 clang/include/clang/AST/TypeProperties.td |  2 +-
 clang/include/clang/Sema/Sema.h           |  6 +-
 clang/lib/AST/Decl.cpp                    |  4 +-
 clang/lib/AST/Type.cpp                    | 70 +++++++++++------------
 clang/lib/AST/TypePrinter.cpp             |  2 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp  | 63 ++++++++++----------
 clang/lib/Sema/Sema.cpp                   |  6 +-
 clang/lib/Sema/SemaDecl.cpp               | 10 ++--
 clang/lib/Sema/SemaDeclCXX.cpp            |  6 +-
 clang/lib/Sema/SemaType.cpp               |  6 +-
 clang/lib/Serialization/ASTReader.cpp     |  2 +-
 13 files changed, 123 insertions(+), 126 deletions(-)

diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index 71aed63c87258b..6d4f9a3c02c1f9 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -3008,7 +3008,7 @@ class FunctionDecl : public DeclaratorDecl,
   /// computed and stored.
   unsigned getODRHash() const;
 
-  FunctionTypeEffectsRef getFunctionEffects() const;
+  FunctionEffectsRef getFunctionEffects() const;
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
@@ -4635,7 +4635,7 @@ class BlockDecl : public Decl, public DeclContext {
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
-  FunctionTypeEffectsRef getFunctionEffects() const;
+  FunctionEffectsRef getFunctionEffects() const;
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 008eb2d177e945..2942a5c5d84877 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4438,8 +4438,8 @@ class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
 
 class Decl;
 class CXXMethodDecl;
-class FunctionTypeEffectsRef;
-class FunctionTypeEffectSet;
+class FunctionEffectsRef;
+class FunctionEffectSet;
 
 /*
   TODO: Idea about how to move most of the FunctionEffect business out of
@@ -4452,7 +4452,7 @@ class FunctionTypeEffectSet;
   and ArrayRef<FunctionEffectCondition>.
   - Somewhere in Sema, define ExtFunctionEffect, which holds a FunctionEffect
     and has all the behavior-related methods.
-  - There too, define the containers. FunctionTypeEffectsRef can have a
+  - There too, define the containers. FunctionEffectsRef can have a
   constructor or factory method that initializes itself from a
   FunctionProtoType.
 */
@@ -4529,24 +4529,24 @@ class FunctionEffect {
   /// Return true if adding or removing the effect as part of a type conversion
   /// should generate a diagnostic.
   bool shouldDiagnoseConversion(bool Adding, QualType OldType,
-                                const FunctionTypeEffectsRef &OldFX,
+                                const FunctionEffectsRef &OldFX,
                                 QualType NewType,
-                                const FunctionTypeEffectsRef &NewFX) const;
+                                const FunctionEffectsRef &NewFX) const;
 
   /// Return true if adding or removing the effect in a redeclaration should
   /// generate a diagnostic.
   bool shouldDiagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
-                                   const FunctionTypeEffectsRef &OldFX,
+                                   const FunctionEffectsRef &OldFX,
                                    const FunctionDecl &NewFunction,
-                                   const FunctionTypeEffectsRef &NewFX) const;
+                                   const FunctionEffectsRef &NewFX) const;
 
   /// Return true if adding or removing the effect in a C++ virtual method
   /// override should generate a diagnostic.
   OverrideResult
   shouldDiagnoseMethodOverride(bool Adding, const CXXMethodDecl &OldMethod,
-                               const FunctionTypeEffectsRef &OldFX,
+                               const FunctionEffectsRef &OldFX,
                                const CXXMethodDecl &NewMethod,
-                               const FunctionTypeEffectsRef &NewFX) const;
+                               const FunctionEffectsRef &NewFX) const;
 
   /// Return true if the effect is allowed to be inferred on the callee,
   /// which is either a FunctionDecl or BlockDecl.
@@ -4625,8 +4625,8 @@ template <typename Container> class FunctionEffectIterator {
 /// An immutable set of FunctionEffects and possibly conditions attached to
 /// them. The effects and conditions reside in memory not managed by this object
 /// (typically, trailing objects in FunctionProtoType, or borrowed references
-/// from a FunctionTypeEffectSet).
-class FunctionTypeEffectsRef {
+/// from a FunctionEffectSet).
+class FunctionEffectsRef {
   ArrayRef<FunctionEffect> Effects;
 
   // The array of conditions is either empty or has the same size
@@ -4636,13 +4636,13 @@ class FunctionTypeEffectsRef {
 public:
   /// Extract the effects from a Type if it is a function, block, or member
   /// function pointer, or a reference or pointer to one.
-  static FunctionTypeEffectsRef get(QualType QT);
+  static FunctionEffectsRef get(QualType QT);
 
-  FunctionTypeEffectsRef() = default;
+  FunctionEffectsRef() = default;
 
   // The arrays are expected to have been sorted by the caller.
-  FunctionTypeEffectsRef(ArrayRef<FunctionEffect> FX,
-                         ArrayRef<FunctionEffectCondition> Conds)
+  FunctionEffectsRef(ArrayRef<FunctionEffect> FX,
+                     ArrayRef<FunctionEffectCondition> Conds)
       : Effects(FX), Conditions(Conds) {}
 
   bool empty() const { return Effects.empty(); }
@@ -4651,17 +4651,17 @@ class FunctionTypeEffectsRef {
   ArrayRef<FunctionEffect> effects() const { return Effects; }
   ArrayRef<FunctionEffectCondition> conditions() const { return Conditions; }
 
-  using iterator = FunctionEffectIterator<FunctionTypeEffectsRef>;
+  using iterator = FunctionEffectIterator<FunctionEffectsRef>;
   friend iterator;
   iterator begin() const { return iterator(*this, 0); }
   iterator end() const { return iterator(*this, size()); }
 
-  friend bool operator==(const FunctionTypeEffectsRef &LHS,
-                         const FunctionTypeEffectsRef &RHS) {
+  friend bool operator==(const FunctionEffectsRef &LHS,
+                         const FunctionEffectsRef &RHS) {
     return LHS.Effects == RHS.Effects && LHS.Conditions == RHS.Conditions;
   }
-  friend bool operator!=(const FunctionTypeEffectsRef &LHS,
-                         const FunctionTypeEffectsRef &RHS) {
+  friend bool operator!=(const FunctionEffectsRef &LHS,
+                         const FunctionEffectsRef &RHS) {
     return !(LHS == RHS);
   }
 
@@ -4671,45 +4671,45 @@ class FunctionTypeEffectsRef {
 
 /// A mutable set of FunctionEffects and possibly conditions attached to them.
 /// Used transitorily within Sema to compare and merge effects on declarations.
-class FunctionTypeEffectSet {
+class FunctionEffectSet {
   SmallVector<FunctionEffect> Effects;
   // The vector of conditions is either empty or has the same size
   // as the vector of effects.
   SmallVector<FunctionEffectCondition> Conditions;
 
 public:
-  FunctionTypeEffectSet() = default;
+  FunctionEffectSet() = default;
 
-  explicit FunctionTypeEffectSet(const FunctionTypeEffectsRef &FX)
+  explicit FunctionEffectSet(const FunctionEffectsRef &FX)
       : Effects(FX.effects()), Conditions(FX.conditions()) {}
 
   bool empty() const { return Effects.empty(); }
   size_t size() const { return Effects.size(); }
 
-  using iterator = FunctionEffectIterator<FunctionTypeEffectSet>;
+  using iterator = FunctionEffectIterator<FunctionEffectSet>;
   friend iterator;
   iterator begin() const { return iterator(*this, 0); }
   iterator end() const { return iterator(*this, size()); }
 
-  operator FunctionTypeEffectsRef() const { return {Effects, Conditions}; }
+  operator FunctionEffectsRef() const { return {Effects, Conditions}; }
 
   void dump(llvm::raw_ostream &OS) const;
 
   // Mutators
   void insert(FunctionEffect Effect, const Expr *Cond);
-  void insert(const FunctionTypeEffectsRef &Set);
-  void insertIgnoringConditions(const FunctionTypeEffectsRef &Set);
+  void insert(const FunctionEffectsRef &Set);
+  void insertIgnoringConditions(const FunctionEffectsRef &Set);
 
   // Set operations
 
   using Differences =
       SmallVector<std::pair<CondFunctionEffect, /*added=*/bool>>;
   /// Caller should short-circuit by checking for equality first.
-  static Differences differences(const FunctionTypeEffectsRef &Old,
-                                 const FunctionTypeEffectsRef &New);
+  static Differences differences(const FunctionEffectsRef &Old,
+                                 const FunctionEffectsRef &New);
 
-  static FunctionTypeEffectSet getUnion(FunctionTypeEffectsRef LHS,
-                                        FunctionTypeEffectsRef RHS);
+  static FunctionEffectSet getUnion(FunctionEffectsRef LHS,
+                                    FunctionEffectsRef RHS);
 };
 
 /// Represents a prototype with parameter type info, e.g.
@@ -4822,7 +4822,7 @@ class FunctionProtoType final
     ExceptionSpecInfo ExceptionSpec;
     const ExtParameterInfo *ExtParameterInfos = nullptr;
     SourceLocation EllipsisLoc;
-    FunctionTypeEffectsRef FunctionEffects;
+    FunctionEffectsRef FunctionEffects;
 
     ExtProtoInfo()
         : Variadic(false), HasTrailingReturn(false),
@@ -5249,14 +5249,14 @@ class FunctionProtoType final
   }
 
   // Combines effects with their conditions.
-  FunctionTypeEffectsRef getFunctionEffects() const {
+  FunctionEffectsRef getFunctionEffects() const {
     if (hasExtraBitfields()) {
       const auto *Bitfields = getTrailingObjects<FunctionTypeExtraBitfields>();
       if (Bitfields->NumFunctionEffects > 0) {
         const size_t NumConds = Bitfields->EffectsHaveConditions
                                     ? Bitfields->NumFunctionEffects
                                     : 0;
-        return FunctionTypeEffectsRef(
+        return FunctionEffectsRef(
             {getTrailingObjects<FunctionEffect>(),
              Bitfields->NumFunctionEffects},
             {NumConds ? getTrailingObjects<FunctionEffectCondition>() : nullptr,
diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
index 0cbbdbd2911eaf..f98659dca73c67 100644
--- a/clang/include/clang/AST/TypeProperties.td
+++ b/clang/include/clang/AST/TypeProperties.td
@@ -374,7 +374,7 @@ let Class = FunctionProtoType in {
     epi.ExtParameterInfos =
       extParameterInfo.empty() ? nullptr : extParameterInfo.data();
     epi.AArch64SMEAttributes = AArch64SMEAttributes;
-    epi.FunctionEffects = FunctionTypeEffectsRef(functionEffects, functionEffectConds);
+    epi.FunctionEffects = FunctionEffectsRef(functionEffects, functionEffectConds);
     return ctx.getFunctionType(returnType, parameters, epi);
   }]>;
 }
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index ff11b4f6b4d0f0..f82b8db2ef8413 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -943,18 +943,18 @@ class Sema final {
   // out of Type.h, but where to?
 
   /// All functions/lambdas/blocks which have bodies and which have a non-empty
-  /// FunctionTypeEffectsRef to be verified.
+  /// FunctionEffectsRef to be verified.
   SmallVector<const Decl *> DeclsWithEffectsToVerify;
   /// The union of all effects present on DeclsWithEffectsToVerify. Conditions
   /// are all null.
-  FunctionTypeEffectSet AllEffectsToVerify;
+  FunctionEffectSet AllEffectsToVerify;
 
   /// Warn when implicitly changing function effects.
   void diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
                                         SourceLocation Loc);
 
   /// Potentially add a FunctionDecl or BlockDecl to DeclsWithEffectsToVerify.
-  void maybeAddDeclWithEffects(const Decl *D, const FunctionTypeEffectsRef &FX);
+  void maybeAddDeclWithEffects(const Decl *D, const FunctionEffectsRef &FX);
 
   // ----- function effects --- where ?????
 
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 740542b3767191..524956ea18678f 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -4508,7 +4508,7 @@ unsigned FunctionDecl::getODRHash() {
 // Effects may differ between declarations, but they should be propagated from
 // old to new on any redeclaration, so it suffices to look at
 // getMostRecentDecl().
-FunctionTypeEffectsRef FunctionDecl::getFunctionEffects() const {
+FunctionEffectsRef FunctionDecl::getFunctionEffects() const {
   if (const auto *FPT =
           getMostRecentDecl()->getType()->getAs<FunctionProtoType>()) {
     return FPT->getFunctionEffects();
@@ -5240,7 +5240,7 @@ SourceRange BlockDecl::getSourceRange() const {
   return SourceRange(getLocation(), Body ? Body->getEndLoc() : getLocation());
 }
 
-FunctionTypeEffectsRef BlockDecl::getFunctionEffects() const {
+FunctionEffectsRef BlockDecl::getFunctionEffects() const {
   if (auto *TSI = getSignatureAsWritten()) {
     if (auto *FPT = TSI->getType()->getAs<FunctionProtoType>()) {
       return FPT->getFunctionEffects();
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 2c21db8ff46e73..b6db9bededa9a8 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5050,8 +5050,8 @@ StringRef FunctionEffect::name() const {
 }
 
 bool FunctionEffect::shouldDiagnoseConversion(
-    bool Adding, QualType OldType, const FunctionTypeEffectsRef &OldFX,
-    QualType NewType, const FunctionTypeEffectsRef &NewFX) const {
+    bool Adding, QualType OldType, const FunctionEffectsRef &OldFX,
+    QualType NewType, const FunctionEffectsRef &NewFX) const {
 
   switch (kind()) {
   case Kind::NonAllocating:
@@ -5075,8 +5075,8 @@ bool FunctionEffect::shouldDiagnoseConversion(
 
 bool FunctionEffect::shouldDiagnoseRedeclaration(
     bool Adding, const FunctionDecl &OldFunction,
-    const FunctionTypeEffectsRef &OldFX, const FunctionDecl &NewFunction,
-    const FunctionTypeEffectsRef &NewFX) const {
+    const FunctionEffectsRef &OldFX, const FunctionDecl &NewFunction,
+    const FunctionEffectsRef &NewFX) const {
   switch (kind()) {
   case Kind::NonAllocating:
   case Kind::NonBlocking:
@@ -5091,8 +5091,8 @@ bool FunctionEffect::shouldDiagnoseRedeclaration(
 
 FunctionEffect::OverrideResult FunctionEffect::shouldDiagnoseMethodOverride(
     bool Adding, const CXXMethodDecl &OldMethod,
-    const FunctionTypeEffectsRef &OldFX, const CXXMethodDecl &NewMethod,
-    const FunctionTypeEffectsRef &NewFX) const {
+    const FunctionEffectsRef &OldFX, const CXXMethodDecl &NewMethod,
+    const FunctionEffectsRef &NewFX) const {
   switch (kind()) {
   case Kind::NonAllocating:
   case Kind::NonBlocking:
@@ -5163,7 +5163,7 @@ bool FunctionEffect::shouldDiagnoseFunctionCall(
 
 // =====
 
-void FunctionTypeEffectsRef::Profile(llvm::FoldingSetNodeID &ID) const {
+void FunctionEffectsRef::Profile(llvm::FoldingSetNodeID &ID) const {
   const bool HasConds = !Conditions.empty();
 
   ID.AddInteger(size() | (HasConds << 31u));
@@ -5174,7 +5174,7 @@ void FunctionTypeEffectsRef::Profile(llvm::FoldingSetNodeID &ID) const {
   }
 }
 
-void FunctionTypeEffectSet::insert(FunctionEffect Effect, const Expr *Cond) {
+void FunctionEffectSet::insert(FunctionEffect Effect, const Expr *Cond) {
   // lower_bound would be overkill
   unsigned Idx = 0;
   for (unsigned Count = Effects.size(); Idx != Count; ++Idx) {
@@ -5196,39 +5196,38 @@ void FunctionTypeEffectSet::insert(FunctionEffect Effect, const Expr *Cond) {
   Effects.insert(Effects.begin() + Idx, Effect);
 }
 
-void FunctionTypeEffectSet::insert(const FunctionTypeEffectsRef &Set) {
+void FunctionEffectSet::insert(const FunctionEffectsRef &Set) {
   for (const auto &Item : Set)
     insert(Item.Effect, Item.Cond);
 }
 
-void FunctionTypeEffectSet::insertIgnoringConditions(
-    const FunctionTypeEffectsRef &Set) {
+void FunctionEffectSet::insertIgnoringConditions(
+    const FunctionEffectsRef &Set) {
   for (const auto &Item : Set)
     insert(Item.Effect, nullptr);
 }
 
-FunctionTypeEffectSet
-FunctionTypeEffectSet::getUnion(FunctionTypeEffectsRef LHS,
-                                FunctionTypeEffectsRef RHS) {
+FunctionEffectSet FunctionEffectSet::getUnion(FunctionEffectsRef LHS,
+                                              FunctionEffectsRef RHS) {
   // Optimize for either of the two sets being empty (very common).
   if (LHS.empty())
-    return FunctionTypeEffectSet(RHS);
+    return FunctionEffectSet(RHS);
 
-  FunctionTypeEffectSet Result(LHS);
+  FunctionEffectSet Result(LHS);
   Result.insert(RHS);
   return Result;
 }
 
-FunctionTypeEffectSet::Differences
-FunctionTypeEffectSet::differences(const FunctionTypeEffectsRef &Old,
-                                   const FunctionTypeEffectsRef &New) {
+FunctionEffectSet::Differences
+FunctionEffectSet::differences(const FunctionEffectsRef &Old,
+                               const FunctionEffectsRef &New) {
 
-  FunctionTypeEffectSet::Differences Result;
+  FunctionEffectSet::Differences Result;
 
-  FunctionTypeEffectsRef::iterator POld = Old.begin();
-  FunctionTypeEffectsRef::iterator OldEnd = Old.end();
-  FunctionTypeEffectsRef::iterator PNew = New.begin();
-  FunctionTypeEffectsRef::iterator NewEnd = New.end();
+  FunctionEffectsRef::iterator POld = Old.begin();
+  FunctionEffectsRef::iterator OldEnd = Old.end();
+  FunctionEffectsRef::iterator PNew = New.begin();
+  FunctionEffectsRef::iterator NewEnd = New.end();
 
   auto compare = [](const CondFunctionEffect &LHS,
                     const CondFunctionEffect &RHS) {
@@ -5272,24 +5271,24 @@ FunctionTypeEffectSet::differences(const FunctionTypeEffectsRef &Old,
 }
 
 #if 0
-FunctionTypeEffectSet
-FunctionTypeEffectSet::difference(FunctionTypeEffectsRef LHS,
-                                  FunctionTypeEffectsRef RHS) {
-  FunctionTypeEffectSet Result;
+FunctionEffectSet
+FunctionEffectSet::difference(FunctionEffectsRef LHS,
+                                  FunctionEffectsRef RHS) {
+  FunctionEffectSet Result;
   std::set_difference(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
                       std::back_inserter(Result.Impl));
   return Result;
 }
 
-void FunctionTypeEffectSet::insert(FunctionTypeEffectsRef Arr) {
+void FunctionEffectSet::insert(FunctionEffectsRef Arr) {
   // TODO: For large RHS sets, use set_union or a custom insert-in-place
   for (const auto &CFE : Arr) {
     insert(CFE);
   }
 }
 
-void FunctionTypeEffectSet::insertIgnoringConditions(
-    FunctionTypeEffectsRef Arr) {
+void FunctionEffectSet::insertIgnoringConditions(
+    FunctionEffectsRef Arr) {
   // TODO: For large RHS sets, use set_union or a custom insert-in-place
   for (const auto &CFE : Arr) {
     insert(CondFunctionEffect(CFE.effect().kind(), nullptr));
@@ -5297,8 +5296,7 @@ void FunctionTypeEffectSet::insertIgnoringConditions(
 }
 #endif
 
-LLVM_DUMP_METHOD void
-FunctionTypeEffectsRef::dump(llvm::raw_ostream &OS) const {
+LLVM_DUMP_METHOD void FunctionEffectsRef::dump(llvm::raw_ostream &OS) const {
   OS << "Effects{";
   bool First = true;
   for (const auto &CFE : *this) {
@@ -5312,12 +5310,12 @@ FunctionTypeEffectsRef::dump(llvm::raw_ostream &OS) const {
   OS << "}";
 }
 
-LLVM_DUMP_METHOD void FunctionTypeEffectSet::dump(llvm::raw_ostream &OS) const {
-  FunctionTypeEffectsRef(*this).dump(OS);
+LLVM_DUMP_METHOD void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
+  FunctionEffectsRef(*this).dump(OS);
 }
 
 // TODO: inline?
-FunctionTypeEffectsRef FunctionTypeEffectsRef::get(QualType QT) {
+FunctionEffectsRef FunctionEffectsRef::get(QualType QT) {
   if (QT->isReferenceType())
     QT = QT.getNonReferenceType();
   if (QT->isPointerType())
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 01708bb85b5fea..e0e2782b972bda 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -998,7 +998,7 @@ void TypePrinter::printFunctionProtoAfter(const FunctionProtoType *T,
   }
   T->printExceptionSpecification(OS, Policy);
 
-  const FunctionTypeEffectsRef FX = T->getFunctionEffects();
+  const FunctionEffectsRef FX = T->getFunctionEffects();
   for (const auto &CFE : FX)
     OS << " __attribute__((clang_" << CFE.Effect.name() << "))";
   // $$$ TODO: Conditions ???
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 482358839767b0..2ba97e5eac1085 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2456,10 +2456,10 @@ static bool functionIsVerifiable(const FunctionDecl *FD) {
 #if 0
 /// A mutable set of FunctionEffect, for use in places where any conditions
 /// have been resolved or can be ignored.
-class FunctionEffectSet {
+class EffectSet {
   SmallVector<FunctionEffect, 4> Impl;
 public:
-  FunctionEffectSet() = default;
+  EffectSet() = default;
 
   operator ArrayRef<FunctionEffect>() const { return Impl; }
 
@@ -2468,12 +2468,12 @@ class FunctionEffectSet {
   iterator end() const { return Impl.end(); }
 
   void insert(const FunctionEffect &Effect);
-  void insert(const FunctionEffectSet &Set);
+  void insert(const EffectSet &Set);
   void insertIgnoringConditions(ArrayRef<CondFunctionEffect> Arr);
 
   void dump(llvm::raw_ostream &OS) const;
 
-  static FunctionEffectSet difference(ArrayRef<FunctionEffect> LHS, ArrayRef<FunctionEffect> RHS);
+  static EffectSet difference(ArrayRef<FunctionEffect> LHS, ArrayRef<FunctionEffect> RHS);
 };
 #endif
 
@@ -2483,7 +2483,7 @@ class FunctionEffectSet {
 // byte, and there are only 2 possible effects, this is more than sufficient. In
 // AnalysisBasedWarnings, we hold one of these for every function visited,
 // which, due to inference, can be many more functions than have effects.)
-class FunctionEffectSet {
+class EffectSet {
   template <typename T, typename SizeT, SizeT Capacity> struct FixedVector {
     SizeT Count = 0;
     T Items[Capacity] = {};
@@ -2515,7 +2515,7 @@ class FunctionEffectSet {
   FixedVector<FunctionEffect, uint8_t, 7> Impl;
 
 public:
-  FunctionEffectSet() = default;
+  EffectSet() = default;
 
   operator ArrayRef<FunctionEffect>() const {
     return ArrayRef(Impl.cbegin(), Impl.cend());
@@ -2526,16 +2526,16 @@ class FunctionEffectSet {
   iterator end() const { return Impl.cend(); }
 
   void insert(const FunctionEffect &Effect);
-  void insert(const FunctionEffectSet &Set);
-  void insertIgnoringConditions(const FunctionTypeEffectsRef &FX);
+  void insert(const EffectSet &Set);
+  void insertIgnoringConditions(const FunctionEffectsRef &FX);
 
   void dump(llvm::raw_ostream &OS) const;
 
-  static FunctionEffectSet difference(ArrayRef<FunctionEffect> LHS,
-                                      ArrayRef<FunctionEffect> RHS);
+  static EffectSet difference(ArrayRef<FunctionEffect> LHS,
+                              ArrayRef<FunctionEffect> RHS);
 };
 
-void FunctionEffectSet::insert(const FunctionEffect &Effect) {
+void EffectSet::insert(const FunctionEffect &Effect) {
   FunctionEffect *Iter = Impl.begin();
   FunctionEffect *End = Impl.end();
   // lower_bound is overkill for a tiny vector like this
@@ -2548,18 +2548,17 @@ void FunctionEffectSet::insert(const FunctionEffect &Effect) {
   Impl.insert(Iter, Effect);
 }
 
-void FunctionEffectSet::insert(const FunctionEffectSet &Set) {
+void EffectSet::insert(const EffectSet &Set) {
   for (auto &Item : Set)
     insert(Item);
 }
 
-void FunctionEffectSet::insertIgnoringConditions(
-    const FunctionTypeEffectsRef &FX) {
+void EffectSet::insertIgnoringConditions(const FunctionEffectsRef &FX) {
   for (const auto &Item : FX)
     insert(Item.Effect);
 }
 
-LLVM_DUMP_METHOD void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
+LLVM_DUMP_METHOD void EffectSet::dump(llvm::raw_ostream &OS) const {
   OS << "Effects{";
   bool First = true;
   for (const auto &Effect : *this) {
@@ -2572,9 +2571,9 @@ LLVM_DUMP_METHOD void FunctionEffectSet::dump(llvm::raw_ostream &OS) const {
   OS << "}";
 }
 
-FunctionEffectSet FunctionEffectSet::difference(ArrayRef<FunctionEffect> LHS,
-                                                ArrayRef<FunctionEffect> RHS) {
-  FunctionEffectSet Result;
+EffectSet EffectSet::difference(ArrayRef<FunctionEffect> LHS,
+                                ArrayRef<FunctionEffect> RHS) {
+  EffectSet Result;
   std::set_difference(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
                       std::back_inserter(Result.Impl));
   return Result;
@@ -2588,13 +2587,13 @@ struct CallableInfo {
   mutable std::optional<std::string>
       MaybeName; // mutable because built on demand in const method
   SpecialFuncType FuncType = SpecialFuncType::None;
-  FunctionEffectSet Effects;
+  EffectSet Effects;
   CallType CType = CallType::Unknown;
 
   CallableInfo(const Decl &CD, SpecialFuncType FT = SpecialFuncType::None)
       : CDecl(&CD), FuncType(FT) {
     // llvm::errs() << "CallableInfo " << name() << "\n";
-    FunctionTypeEffectsRef FX;
+    FunctionEffectsRef FX;
 
     if (auto *FD = dyn_cast<FunctionDecl>(CDecl)) {
       // Use the function's definition, if any.
@@ -2613,7 +2612,7 @@ struct CallableInfo {
       FX = BD->getFunctionEffects();
     } else if (auto *VD = dyn_cast<ValueDecl>(CDecl)) {
       // ValueDecl is function, enum, or variable, so just look at its type.
-      FX = FunctionTypeEffectsRef::get(VD->getType());
+      FX = FunctionEffectsRef::get(VD->getType());
     }
     Effects.insertIgnoringConditions(FX);
   }
@@ -2708,7 +2707,7 @@ class EffectToDiagnosticMap {
 // ----------
 // State pertaining to a function whose AST is walked. Since there are
 // potentially a large number of these objects, it needs care about size.
-// TODO: FunctionEffectSet could be made much smaller.
+// TODO: EffectSet could be made much smaller.
 class PendingFunctionAnalysis {
   friend class CompleteFunctionAnalysis;
 
@@ -2732,8 +2731,8 @@ class PendingFunctionAnalysis {
   // We always have two disjoint sets of effects to verify:
   // 1. Effects declared explicitly by this function.
   // 2. All other inferrable effects needing verification.
-  FunctionEffectSet DeclaredVerifiableEffects;
-  FunctionEffectSet FXToInfer;
+  EffectSet DeclaredVerifiableEffects;
+  EffectSet FXToInfer;
 
 private:
   // Diagnostics pertaining to the function's explicit effects. Use a unique_ptr
@@ -2753,7 +2752,7 @@ class PendingFunctionAnalysis {
     DeclaredVerifiableEffects = CInfo.Effects;
 
     // Check for effects we are not allowed to infer
-    FunctionEffectSet FX;
+    EffectSet FX;
 
     for (const auto &effect : AllInferrableEffectsToVerify) {
       if (effect.canInferOnFunction(*CInfo.CDecl)) {
@@ -2769,7 +2768,7 @@ class PendingFunctionAnalysis {
       }
     }
     // FX is now the set of inferrable effects which are not prohibited
-    FXToInfer = FunctionEffectSet::difference(FX, DeclaredVerifiableEffects);
+    FXToInfer = EffectSet::difference(FX, DeclaredVerifiableEffects);
   }
 
   // Hide the way that diagnostics for explicitly required effects vs. inferred
@@ -2843,7 +2842,7 @@ class CompleteFunctionAnalysis {
   // ones which have been successfully inferred. These are all considered
   // "verified" for the purposes of callers; any issue with verifying declared
   // effects has already been reported and is not the problem of any caller.
-  FunctionEffectSet VerifiedEffects;
+  EffectSet VerifiedEffects;
 
 private:
   // This is used to generate notes about failed inference.
@@ -2852,7 +2851,7 @@ class CompleteFunctionAnalysis {
 public:
   CompleteFunctionAnalysis(
       ASTContext &Ctx, PendingFunctionAnalysis &pending,
-      const FunctionEffectSet &funcFX,
+      const EffectSet &funcFX,
       ArrayRef<FunctionEffect> AllInferrableEffectsToVerify) {
     VerifiedEffects.insert(funcFX);
     for (const auto &effect : AllInferrableEffectsToVerify) {
@@ -2897,7 +2896,7 @@ class Analyzer {
   //  SmallVector<const Decl *> CallablesWithEffectsToVerify
 
   // Subset of Sema.AllEffectsToVerify
-  FunctionEffectSet AllInferrableEffectsToVerify;
+  EffectSet AllInferrableEffectsToVerify;
 
   using FuncAnalysisPtr =
       llvm::PointerUnion<PendingFunctionAnalysis *, CompleteFunctionAnalysis *>;
@@ -3138,7 +3137,7 @@ class Analyzer {
     const bool DirectCall = Callee.isDirectCall();
 
     // These will be its declared effects.
-    FunctionEffectSet CalleeEffects = Callee.Effects;
+    EffectSet CalleeEffects = Callee.Effects;
 
     bool IsInferencePossible = DirectCall;
 
@@ -3444,7 +3443,7 @@ class Analyzer {
       const auto CalleeType = CalleeExpr->getType();
       auto *FPT =
           CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
-      FunctionEffectSet CalleeFX;
+      EffectSet CalleeFX;
       if (FPT)
         CalleeFX.insertIgnoringConditions(FPT->getFunctionEffects());
       static_assert(sizeof(FunctionEffect) == 1);
@@ -3725,7 +3724,7 @@ class Analyzer {
       }
     }
 
-    static FunctionTypeEffectsRef functionEffectsForDecl(const Decl *D) {
+    static FunctionEffectsRef functionEffectsForDecl(const Decl *D) {
       if (auto *FD = D->getAsFunction()) {
         return FD->getFunctionEffects();
       }
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index b0cbdedbc2875b..4ac0208512f188 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -590,10 +590,10 @@ void Sema::diagnoseNullableToNonnullConversion(QualType DstType,
 // Generate diagnostics when adding or removing effects in a type conversion.
 void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
                                             SourceLocation Loc) {
-  const auto SrcFX = FunctionTypeEffectsRef::get(SrcType);
-  const auto DstFX = FunctionTypeEffectsRef::get(DstType);
+  const auto SrcFX = FunctionEffectsRef::get(SrcType);
+  const auto DstFX = FunctionEffectsRef::get(DstType);
   if (SrcFX != DstFX) {
-    for (const auto &Item : FunctionTypeEffectSet::differences(SrcFX, DstFX)) {
+    for (const auto &Item : FunctionEffectSet::differences(SrcFX, DstFX)) {
       const FunctionEffect &Effect = Item.first.Effect;
       const bool Adding = Item.second;
       if (Effect.shouldDiagnoseConversion(Adding, SrcType, SrcFX, DstType,
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 17aec3f57ac970..60c7fe74729503 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3924,7 +3924,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
   const auto NewFX = New->getFunctionEffects();
   QualType OldQTypeForComparison = OldQType;
   if (OldFX != NewFX) {
-    const auto Diffs = FunctionTypeEffectSet::differences(OldFX, NewFX);
+    const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
     for (const auto &Item : Diffs) {
       const FunctionEffect &Effect = Item.first.Effect;
       const bool Adding = Item.second;
@@ -3940,10 +3940,10 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
     // declaration, but that would trigger an additional "conflicting types"
     // error.
     if (const auto *NewFPT = NewQType->getAs<FunctionProtoType>()) {
-      auto MergedFX = FunctionTypeEffectSet::getUnion(OldFX, NewFX);
+      auto MergedFX = FunctionEffectSet::getUnion(OldFX, NewFX);
 
       FunctionProtoType::ExtProtoInfo EPI = NewFPT->getExtProtoInfo();
-      EPI.FunctionEffects = FunctionTypeEffectsRef(MergedFX);
+      EPI.FunctionEffects = FunctionEffectsRef(MergedFX);
       QualType ModQT = Context.getFunctionType(NewFPT->getReturnType(),
                                                NewFPT->getParamTypes(), EPI);
 
@@ -3954,7 +3954,7 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
       // so as not to fail due to differences later.
       if (const auto *OldFPT = OldQType->getAs<FunctionProtoType>()) {
         EPI = OldFPT->getExtProtoInfo();
-        EPI.FunctionEffects = FunctionTypeEffectsRef(MergedFX);
+        EPI.FunctionEffects = FunctionEffectsRef(MergedFX);
         OldQTypeForComparison = Context.getFunctionType(
             OldFPT->getReturnType(), OldFPT->getParamTypes(), EPI);
       }
@@ -11129,7 +11129,7 @@ Attr *Sema::getImplicitCodeSegOrSectionAttrForFunction(const FunctionDecl *FD,
 // Should only be called when getFunctionEffects() returns a non-empty set.
 // Decl should be a FunctionDecl or BlockDecl.
 void Sema::maybeAddDeclWithEffects(const Decl *D,
-                                   const FunctionTypeEffectsRef &FX) {
+                                   const FunctionEffectsRef &FX) {
   if (!D->hasBody()) {
     if (const auto *FD = D->getAsFunction()) {
       if (!FD->willHaveBody()) {
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index fb4850fefe8c97..1e89f97bc5f204 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18329,7 +18329,7 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
   const auto NewFX = New->getFunctionEffects();
 
   if (OldFX != NewFX) {
-    const auto Diffs = FunctionTypeEffectSet::differences(OldFX, NewFX);
+    const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
     bool AnyDiags = false;
 
     for (const auto &Item : Diffs) {
@@ -18347,10 +18347,10 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
         AnyDiags = true;
         break;
       case FunctionEffect::OverrideResult::Merge: {
-        auto MergedFX = FunctionTypeEffectSet::getUnion(OldFX, NewFX);
+        auto MergedFX = FunctionEffectSet::getUnion(OldFX, NewFX);
 
         FunctionProtoType::ExtProtoInfo EPI = NewFT->getExtProtoInfo();
-        EPI.FunctionEffects = FunctionTypeEffectsRef(MergedFX);
+        EPI.FunctionEffects = FunctionEffectsRef(MergedFX);
         QualType ModQT = Context.getFunctionType(NewFT->getReturnType(),
                                                  NewFT->getParamTypes(), EPI);
         New->setType(ModQT);
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 68fe306cf326e4..eb396c6f372046 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8116,16 +8116,16 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
   }
 
   // nonblocking(true) and nonallocating(true) are represented as
-  // FunctionEffects, in a FunctionTypeEffectsRef attached to a
+  // FunctionEffects, in a FunctionEffectsRef attached to a
   // FunctionProtoType.
   const FunctionEffect NewEffect(isNonBlocking
                                      ? FunctionEffect::Kind::NonBlocking
                                      : FunctionEffect::Kind::NonAllocating);
 
   FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
-  FunctionTypeEffectSet FX(EPI.FunctionEffects);
+  FunctionEffectSet FX(EPI.FunctionEffects);
   FX.insert(NewEffect, nullptr);
-  EPI.FunctionEffects = FunctionTypeEffectsRef(FX);
+  EPI.FunctionEffects = FunctionEffectsRef(FX);
 
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
                                                FPT->getParamTypes(), EPI);
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 7d6fc9d03f4c10..dede16d84dc1b3 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -8226,7 +8226,7 @@ void ASTReader::InitializeSema(Sema &S) {
       Decl *D = GetDecl(ID);
       SemaObj->DeclsWithEffectsToVerify.push_back(D);
 
-      FunctionTypeEffectsRef FX;
+      FunctionEffectsRef FX;
       if (auto *FD = dyn_cast<FunctionDecl>(D)) {
         FX = FD->getFunctionEffects();
       } else if (auto *BD = dyn_cast<BlockDecl>(D)) {

>From 80495b7ca14301a43c2e5d6152abca14f6d24627 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 16 Apr 2024 08:24:12 -0700
Subject: [PATCH 35/40] nonblocking(cond) now parsed into new form.

---
 clang/lib/AST/Type.cpp                      |  1 +
 clang/lib/AST/TypePrinter.cpp               | 21 +++++++++------------
 clang/lib/Sema/SemaType.cpp                 | 21 +++------------------
 clang/test/Sema/attr-nonblocking-syntax.cpp | 13 ++++++++++---
 4 files changed, 23 insertions(+), 33 deletions(-)

diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index b6db9bededa9a8..213468b4f10d5d 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3650,6 +3650,7 @@ FunctionProtoType::FunctionProtoType(QualType result, ArrayRef<QualType> params,
     ArrayRef<FunctionEffectCondition> SrcConds =
         epi.FunctionEffects.conditions();
     if (!SrcConds.empty()) {
+      ExtraBits.EffectsHaveConditions = true;
       auto *DestConds = getTrailingObjects<FunctionEffectCondition>();
       std::copy(SrcConds.begin(), SrcConds.end(), DestConds);
     }
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index e0e2782b972bda..ca50b0c046dcb9 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -999,9 +999,15 @@ void TypePrinter::printFunctionProtoAfter(const FunctionProtoType *T,
   T->printExceptionSpecification(OS, Policy);
 
   const FunctionEffectsRef FX = T->getFunctionEffects();
-  for (const auto &CFE : FX)
-    OS << " __attribute__((clang_" << CFE.Effect.name() << "))";
-  // $$$ TODO: Conditions ???
+  for (const auto &CFE : FX) {
+    OS << " __attribute__((clang_" << CFE.Effect.name();
+    if (CFE.Cond) {
+      OS << '(';
+      CFE.Cond->printPretty(OS, nullptr, Policy);
+      OS << ')';
+    }
+    OS << "))";
+  }
 
   if (T->hasTrailingReturn()) {
     OS << " -> ";
@@ -1876,15 +1882,6 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
     return;
   }
 
-  if (T->getAttrKind() == attr::NonBlocking) {
-    OS << " [[clang::nonblocking(...)]]";
-    return;
-  }
-  if (T->getAttrKind() == attr::NonAllocating) {
-    OS << " [[clang::nonallocating(...)]]";
-    return;
-  }
-
   if (T->getAttrKind() == attr::ArmStreaming) {
     OS << "__arm_streaming";
     return;
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index eb396c6f372046..e134822132f6a0 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8088,20 +8088,6 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
     TPState.setParsedNonAllocating(NewState);
   }
 
-  if (NewState == BoolAttrState::Dependent) {
-    // nonblocking(expr)/nonallocating(expr) are represented as AttributedType
-    // sugar, using those attributes. TODO: Currently no one else tries to find
-    // it there, and this may turn out to be the wrong place.
-    Attr *A = nullptr;
-    if (isNonBlocking) {
-      A = NonBlockingAttr::Create(S.Context, CondExpr);
-    } else {
-      A = NonAllocatingAttr::Create(S.Context, CondExpr);
-    }
-    QT = TPState.getAttributedType(A, QT, QT);
-    return true;
-  }
-
   if (NewState == BoolAttrState::False) {
     // blocking and allocating are represented as AttributedType sugar,
     // using those attributes.
@@ -8115,16 +8101,15 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
     return true;
   }
 
-  // nonblocking(true) and nonallocating(true) are represented as
-  // FunctionEffects, in a FunctionEffectsRef attached to a
-  // FunctionProtoType.
+  // nonblocking/nonallocating(true/expr) are represented in a
+  // FunctionEffectsRef attached to a FunctionProtoType.
   const FunctionEffect NewEffect(isNonBlocking
                                      ? FunctionEffect::Kind::NonBlocking
                                      : FunctionEffect::Kind::NonAllocating);
 
   FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
   FunctionEffectSet FX(EPI.FunctionEffects);
-  FX.insert(NewEffect, nullptr);
+  FX.insert(NewEffect, NewState == BoolAttrState::Dependent ? CondExpr : nullptr);
   EPI.FunctionEffects = FunctionEffectsRef(FX);
 
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
diff --git a/clang/test/Sema/attr-nonblocking-syntax.cpp b/clang/test/Sema/attr-nonblocking-syntax.cpp
index f6f58f95fd70db..48ca62f3401e46 100644
--- a/clang/test/Sema/attr-nonblocking-syntax.cpp
+++ b/clang/test/Sema/attr-nonblocking-syntax.cpp
@@ -52,11 +52,18 @@ decltype(nl1) nl3;
 
 // Attribute propagates from base class virtual method to overrides.
 struct Base {
-	virtual void nl_method() [[clang::nonblocking]];
+	virtual void nb_method() [[clang::nonblocking]];
 };
 struct Derived : public Base {
-	void nl_method() override;
-	// CHECK: CXXMethodDecl {{.*}} nl_method 'void () __attribute__((clang_nonblocking))'
+	void nb_method() override;
+	// CHECK: CXXMethodDecl {{.*}} nb_method 'void () __attribute__((clang_nonblocking))'
+};
+
+// Dependent expression
+template <bool V>
+struct Dependent {
+	void nb_method2() [[clang::nonblocking(V)]];
+	// CHECK: CXXMethodDecl {{.*}} nb_method2 'void () __attribute__((clang_nonblocking(V)))'
 };
 
 // --- Blocks ---

>From 1853b39f0e7a28b9593c6e87956a2456ca17b3f3 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Thu, 18 Apr 2024 09:05:50 -0700
Subject: [PATCH 36/40] wip with computed effects

---
 clang/include/clang/AST/AbstractBasicWriter.h |   2 +-
 clang/include/clang/AST/Type.h                |  27 ++--
 .../clang/Basic/DiagnosticSemaKinds.td        |   8 +-
 clang/include/clang/Sema/Sema.h               |  14 ++
 clang/lib/AST/Type.cpp                        |  41 +++--
 clang/lib/AST/TypePrinter.cpp                 |   4 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 145 +++++++++++-------
 clang/lib/Sema/SemaType.cpp                   | 111 +++++++-------
 clang/lib/Sema/TreeTransform.h                |  67 ++++++++
 9 files changed, 283 insertions(+), 136 deletions(-)

diff --git a/clang/include/clang/AST/AbstractBasicWriter.h b/clang/include/clang/AST/AbstractBasicWriter.h
index c269d3f7ed9c31..c6a5748bfbb1b1 100644
--- a/clang/include/clang/AST/AbstractBasicWriter.h
+++ b/clang/include/clang/AST/AbstractBasicWriter.h
@@ -229,7 +229,7 @@ class DataStreamBasicWriter : public BasicWriterBase<Impl> {
   }
 
   void writeFunctionEffectCondition(FunctionEffectCondition CE) {
-    asImpl().writeExprRef(CE.Cond);
+    asImpl().writeExprRef(CE.expr());
   }
 
   void writeNestedNameSpecifier(NestedNameSpecifier *NNS) {
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 2942a5c5d84877..5f003f6e4ecc13 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4578,8 +4578,14 @@ class FunctionEffect {
 
 /// Wrap a function effect's condition expression in another struct so
 /// that FunctionProtoType's TrailingObjects can treat it separately.
-struct FunctionEffectCondition {
-  const Expr *Cond = nullptr; // if null, unconditional
+class FunctionEffectCondition {
+  Expr *Cond = nullptr; // if null, unconditional
+
+public:
+  FunctionEffectCondition() = default;
+  FunctionEffectCondition(Expr *E) : Cond(E) {} // implicit OK
+
+  Expr *expr() const { return Cond; }
 
   bool operator==(const FunctionEffectCondition &RHS) const {
     return Cond == RHS.Cond;
@@ -4589,9 +4595,9 @@ struct FunctionEffectCondition {
 /// A FunctionEffect plus a potential boolean expression determining whether
 /// the effect is declared (e.g. nonblocking(expr)). Generally the condition
 /// expression when present, is dependent.
-struct CondFunctionEffect {
+struct FunctionEffectWithCondition {
   FunctionEffect Effect;
-  const Expr *Cond = nullptr; // if null, unconditional
+  FunctionEffectCondition Cond;
 };
 
 /// Support iteration in parallel through a pair of FunctionEffect and
@@ -4615,10 +4621,10 @@ template <typename Container> class FunctionEffectIterator {
     return *this;
   }
 
-  CondFunctionEffect operator*() const {
+  FunctionEffectWithCondition operator*() const {
     const bool HasConds = !Outer.Conditions.empty();
-    return CondFunctionEffect{Outer.Effects[Idx],
-                              HasConds ? Outer.Conditions[Idx].Cond : nullptr};
+    return FunctionEffectWithCondition{Outer.Effects[Idx],
+                              HasConds ? Outer.Conditions[Idx] : FunctionEffectCondition()};
   }
 };
 
@@ -4696,14 +4702,17 @@ class FunctionEffectSet {
   void dump(llvm::raw_ostream &OS) const;
 
   // Mutators
-  void insert(FunctionEffect Effect, const Expr *Cond);
+  void insert(FunctionEffect Effect, Expr *Cond);
   void insert(const FunctionEffectsRef &Set);
   void insertIgnoringConditions(const FunctionEffectsRef &Set);
 
+  void replaceCondition(unsigned Idx, Expr *Cond);
+  void erase(unsigned Idx);
+
   // Set operations
 
   using Differences =
-      SmallVector<std::pair<CondFunctionEffect, /*added=*/bool>>;
+      SmallVector<std::pair<FunctionEffectWithCondition, /*added=*/bool>>;
   /// Caller should short-circuit by checking for equality first.
   static Differences differences(const FunctionEffectsRef &Old,
                                  const FunctionEffectsRef &New);
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 3608c9403dd341..3ce35abc088b08 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10833,21 +10833,21 @@ def warn_func_effect_calls_objc : Warning<
 def note_func_effect_calls_objc : Note<
   "function cannot be inferred '%0' because it accesses an ObjC method or property">;
 
-def warn_func_effect_calls_disallowed_func : Warning<
+def warn_func_effect_calls_func_without_effect : Warning<
   "'%0' function must not call non-'%0' function '%1'">,
   InGroup<FunctionEffects>;
 
-def warn_func_effect_calls_disallowed_expr : Warning<
+def warn_func_effect_calls_expr_without_effect : Warning<
   "'%0' function must not call non-'%0' expression">,
   InGroup<FunctionEffects>;
 
-def note_func_effect_calls_disallowed_func : Note<
+def note_func_effect_calls_func_without_effect : Note<
   "function cannot be inferred '%0' because it calls non-'%0' function '%1'">;
 
 def note_func_effect_call_extern : Note<
   "function cannot be inferred '%0' because it has no definition in this translation unit">;
 
-def note_func_effect_call_not_inferrable : Note<
+def note_func_effect_call_disallows_inference : Note<
   "function does not permit inference of '%0'">;
 
 def note_func_effect_call_virtual : Note<
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index f82b8db2ef8413..5b417870a9ebbe 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -420,6 +420,14 @@ enum class TemplateDeductionResult {
   AlreadyDiagnosed
 };
 
+/// Used with attributes/effects with a boolean condition, e.g. `nonblocking`.
+enum class FunctionEffectMode {
+  None,     // effect is not present
+  False,    // effect(false)
+  True,     // effect(true)
+  Dependent // effect(expr) where expr is dependent
+};
+
 /// Sema - This implements semantic analysis and AST building for C.
 /// \nosubgrouping
 class Sema final {
@@ -956,6 +964,12 @@ class Sema final {
   /// Potentially add a FunctionDecl or BlockDecl to DeclsWithEffectsToVerify.
   void maybeAddDeclWithEffects(const Decl *D, const FunctionEffectsRef &FX);
 
+  /// Try to parse the conditional expression attached to an effect attribute 
+  /// (e.g. 'nonblocking'). (c.f. Sema::ActOnNoexceptSpec). If RequireConstexpr,
+  /// then this will fail if the expression is dependent.
+  ExprResult ActOnEffectExpression(Expr *CondExpr, FunctionEffectMode &Mode,
+    bool RequireConstexpr = false);
+
   // ----- function effects --- where ?????
 
   bool makeUnavailableInSystemHeader(SourceLocation loc,
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 213468b4f10d5d..bdf6d23eec269f 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3653,6 +3653,9 @@ FunctionProtoType::FunctionProtoType(QualType result, ArrayRef<QualType> params,
       ExtraBits.EffectsHaveConditions = true;
       auto *DestConds = getTrailingObjects<FunctionEffectCondition>();
       std::copy(SrcConds.begin(), SrcConds.end(), DestConds);
+
+      assert(isCanonicalUnqualified()); // TODO: because I don't understand this yet...
+      addDependence(TypeDependence::DependentInstantiation);
     }
   }
 }
@@ -5171,11 +5174,11 @@ void FunctionEffectsRef::Profile(llvm::FoldingSetNodeID &ID) const {
   for (unsigned Idx = 0, Count = Effects.size(); Idx != Count; ++Idx) {
     ID.AddInteger(llvm::to_underlying(Effects[Idx].kind()));
     if (HasConds)
-      ID.AddPointer(Conditions[Idx].Cond);
+      ID.AddPointer(Conditions[Idx].expr());
   }
 }
 
-void FunctionEffectSet::insert(FunctionEffect Effect, const Expr *Cond) {
+void FunctionEffectSet::insert(FunctionEffect Effect, Expr *Cond) {
   // lower_bound would be overkill
   unsigned Idx = 0;
   for (unsigned Count = Effects.size(); Idx != Count; ++Idx) {
@@ -5189,17 +5192,17 @@ void FunctionEffectSet::insert(FunctionEffect Effect, const Expr *Cond) {
       break;
   }
 
-  if (Cond != nullptr) {
+  if (Cond) {
     if (Conditions.empty() && !Effects.empty())
       Conditions.resize(Effects.size());
-    Conditions.insert(Conditions.begin() + Idx, FunctionEffectCondition{Cond});
+    Conditions.insert(Conditions.begin() + Idx, Cond);
   }
   Effects.insert(Effects.begin() + Idx, Effect);
 }
 
 void FunctionEffectSet::insert(const FunctionEffectsRef &Set) {
   for (const auto &Item : Set)
-    insert(Item.Effect, Item.Cond);
+    insert(Item.Effect, Item.Cond.expr());
 }
 
 void FunctionEffectSet::insertIgnoringConditions(
@@ -5208,6 +5211,18 @@ void FunctionEffectSet::insertIgnoringConditions(
     insert(Item.Effect, nullptr);
 }
 
+void FunctionEffectSet::replaceCondition(unsigned Idx, Expr *Cond) {
+  assert(Idx < Conditions.size());
+  Conditions[Idx] = FunctionEffectCondition(Cond);
+}
+
+void FunctionEffectSet::erase(unsigned Idx) {
+  assert(Idx < Effects.size());
+  Effects.erase(Effects.begin() + Idx);
+  if (!Conditions.empty())
+    Conditions.erase(Conditions.begin() + Idx);
+}
+
 FunctionEffectSet FunctionEffectSet::getUnion(FunctionEffectsRef LHS,
                                               FunctionEffectsRef RHS) {
   // Optimize for either of the two sets being empty (very common).
@@ -5230,15 +5245,15 @@ FunctionEffectSet::differences(const FunctionEffectsRef &Old,
   FunctionEffectsRef::iterator PNew = New.begin();
   FunctionEffectsRef::iterator NewEnd = New.end();
 
-  auto compare = [](const CondFunctionEffect &LHS,
-                    const CondFunctionEffect &RHS) {
+  auto compare = [](const FunctionEffectWithCondition &LHS,
+                    const FunctionEffectWithCondition &RHS) {
     if (LHS.Effect < RHS.Effect)
       return -1;
     if (LHS.Effect > RHS.Effect)
       return 1;
-    if (LHS.Cond < RHS.Cond)
+    if (LHS.Cond.expr() < RHS.Cond.expr())
       return -1;
-    if (LHS.Cond > RHS.Cond)
+    if (RHS.Cond.expr() < LHS.Cond.expr())
       return 1;
     return 0;
   };
@@ -5292,7 +5307,7 @@ void FunctionEffectSet::insertIgnoringConditions(
     FunctionEffectsRef Arr) {
   // TODO: For large RHS sets, use set_union or a custom insert-in-place
   for (const auto &CFE : Arr) {
-    insert(CondFunctionEffect(CFE.effect().kind(), nullptr));
+    insert(FunctionEffectWithCondition(CFE.effect().kind(), nullptr));
   }
 }
 #endif
@@ -5306,7 +5321,11 @@ LLVM_DUMP_METHOD void FunctionEffectsRef::dump(llvm::raw_ostream &OS) const {
     else
       First = false;
     OS << CFE.Effect.name();
-    // TODO: Condition
+    if (Expr * E = CFE.Cond.expr()) {
+      OS << '(';
+      E->dump();
+      OS << ')';
+    }
   }
   OS << "}";
 }
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index ca50b0c046dcb9..a87adb5da07246 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -1001,9 +1001,9 @@ void TypePrinter::printFunctionProtoAfter(const FunctionProtoType *T,
   const FunctionEffectsRef FX = T->getFunctionEffects();
   for (const auto &CFE : FX) {
     OS << " __attribute__((clang_" << CFE.Effect.name();
-    if (CFE.Cond) {
+    if (const Expr *E = CFE.Cond.expr()) {
       OS << '(';
-      CFE.Cond->printPretty(OS, nullptr, Policy);
+      E->printPretty(OS, nullptr, Policy);
       OS << ')';
     }
     OS << "))";
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 2ba97e5eac1085..f82b3eee055b60 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2385,7 +2385,7 @@ class UnsafeBufferUsageReporter : public UnsafeBufferUsageHandler {
 // =============================================================================
 
 // Temporary feature enablement
-#define FX_ANALYZER_ENABLED 1
+#define FX_ANALYZER_ENABLED 0
 
 #if FX_ANALYZER_ENABLED
 
@@ -2410,10 +2410,10 @@ enum class DiagnosticID : uint8_t {
   AccessesThreadLocal,
 
   // These only apply to callees, where the analysis stops at the Decl
-  DeclWithoutConstraintOrInference,
+  DeclDisallowsInference,
 
-  CallsUnsafeDecl,
-  CallsDisallowedExpr,
+  CallsDeclWithoutEffect,
+  CallsExprWithoutEffect,
 };
 
 struct Diagnostic {
@@ -2469,7 +2469,7 @@ class EffectSet {
 
   void insert(const FunctionEffect &Effect);
   void insert(const EffectSet &Set);
-  void insertIgnoringConditions(ArrayRef<CondFunctionEffect> Arr);
+  void insertIgnoringConditions(ArrayRef<FunctionEffectWithCondition> Arr);
 
   void dump(llvm::raw_ostream &OS) const;
 
@@ -2528,6 +2528,9 @@ class EffectSet {
   void insert(const FunctionEffect &Effect);
   void insert(const EffectSet &Set);
   void insertIgnoringConditions(const FunctionEffectsRef &FX);
+  bool contains(const FunctionEffect &E) const {
+    return std::find(begin(), end(), E) != end();
+  }
 
   void dump(llvm::raw_ostream &OS) const;
 
@@ -2579,6 +2582,31 @@ EffectSet EffectSet::difference(ArrayRef<FunctionEffect> LHS,
   return Result;
 }
 
+// Represent the declared effects, and absent effects (e.g. nonblocking(false)).
+// Centralize the resolution of computed effects.
+struct CondEffectSet {
+  EffectSet EffectsPresent;
+  EffectSet EffectsExplicitlyAbsent;
+
+  CondEffectSet() = default;
+
+  CondEffectSet(Sema &SemaRef, FunctionEffectsRef FX) {
+    for (const auto Item : FX) {
+      if (Expr *Cond = Item.Cond) {
+        FunctionEffectMode Mode = FunctionEffectMode::None;
+        ExprResult ER = SemaRef.ActOnEffectExpression(Cond, Mode, /*RequireConstexpr=*/true);
+        if (ER.isInvalid() || Mode == FunctionEffectMode::Dependent)
+          continue;
+        if (Mode == FunctionEffectMode::False) {
+          EffectsExplicitlyAbsent.insert(Item.Effect);
+          continue;
+        }
+      }
+      EffectsPresent.insert(Item.Effect);
+    }
+  }
+};
+
 // Transitory, more extended information about a callable, which can be a
 // function, block, function pointer...
 struct CallableInfo {
@@ -2587,13 +2615,13 @@ struct CallableInfo {
   mutable std::optional<std::string>
       MaybeName; // mutable because built on demand in const method
   SpecialFuncType FuncType = SpecialFuncType::None;
-  EffectSet Effects;
+  CondEffectSet Effects;
   CallType CType = CallType::Unknown;
 
-  CallableInfo(const Decl &CD, SpecialFuncType FT = SpecialFuncType::None)
+  CallableInfo(Sema &SemaRef, const Decl &CD, SpecialFuncType FT = SpecialFuncType::None)
       : CDecl(&CD), FuncType(FT) {
     // llvm::errs() << "CallableInfo " << name() << "\n";
-    FunctionEffectsRef FX;
+    FunctionEffectsRef FXRef;
 
     if (auto *FD = dyn_cast<FunctionDecl>(CDecl)) {
       // Use the function's definition, if any.
@@ -2606,15 +2634,15 @@ struct CallableInfo {
           CType = CallType::Virtual;
         }
       }
-      FX = FD->getFunctionEffects();
+      FXRef = FD->getFunctionEffects();
     } else if (auto *BD = dyn_cast<BlockDecl>(CDecl)) {
       CType = CallType::Block;
-      FX = BD->getFunctionEffects();
+      FXRef = BD->getFunctionEffects();
     } else if (auto *VD = dyn_cast<ValueDecl>(CDecl)) {
       // ValueDecl is function, enum, or variable, so just look at its type.
-      FX = FunctionEffectsRef::get(VD->getType());
+      FXRef = FunctionEffectsRef::get(VD->getType());
     }
-    Effects.insertIgnoringConditions(FX);
+    Effects = CondEffectSet(SemaRef, FXRef);
   }
 
   bool isDirectCall() const {
@@ -2749,13 +2777,13 @@ class PendingFunctionAnalysis {
   PendingFunctionAnalysis(
       Sema &Sem, const CallableInfo &CInfo,
       ArrayRef<FunctionEffect> AllInferrableEffectsToVerify) {
-    DeclaredVerifiableEffects = CInfo.Effects;
+    DeclaredVerifiableEffects = CInfo.Effects.EffectsPresent;
 
     // Check for effects we are not allowed to infer
     EffectSet FX;
 
     for (const auto &effect : AllInferrableEffectsToVerify) {
-      if (effect.canInferOnFunction(*CInfo.CDecl)) {
+      if (effect.canInferOnFunction(*CInfo.CDecl) && !CInfo.Effects.EffectsExplicitlyAbsent.contains(effect)) {
         FX.insert(effect);
       } else {
         // Add a diagnostic for this effect if a caller were to
@@ -2763,7 +2791,7 @@ class PendingFunctionAnalysis {
         auto &diag =
             InferrableEffectToFirstDiagnostic.getOrInsertDefault(effect);
         diag =
-            Diagnostic(effect, DiagnosticID::DeclWithoutConstraintOrInference,
+            Diagnostic(effect, DiagnosticID::DeclDisallowsInference,
                        CInfo.CDecl->getLocation());
       }
     }
@@ -2813,8 +2841,7 @@ class PendingFunctionAnalysis {
     return DiagnosticsForExplicitFX.get();
   }
 
-  // If Sema is supplied, prints names of unverified direct calls
-  void dump(llvm::raw_ostream &OS, Sema *SemPtr = nullptr) const {
+  void dump(Sema &SemaRef, llvm::raw_ostream &OS) const {
     OS << "Pending: Declared ";
     DeclaredVerifiableEffects.dump(OS);
     OS << ", "
@@ -2823,11 +2850,11 @@ class PendingFunctionAnalysis {
     OS << " Infer ";
     FXToInfer.dump(OS);
     OS << ", " << InferrableEffectToFirstDiagnostic.size() << " diags";
-    if (SemPtr && UnverifiedDirectCalls) {
+    if (UnverifiedDirectCalls) {
       OS << "; Calls: ";
       for (const auto &Call : *UnverifiedDirectCalls) {
-        CallableInfo CI(*Call.callee());
-        OS << " " << CI.name(*SemPtr);
+        CallableInfo CI(SemaRef, *Call.callee());
+        OS << " " << CI.name(SemaRef);
       }
     }
     OS << "\n";
@@ -2888,7 +2915,7 @@ const Decl *CanonicalFunctionDecl(const Decl *D) {
 
 // ==========
 class Analyzer {
-  constexpr static int DebugLogLevel = 0;
+  constexpr static int DebugLogLevel = 3;
   // --
   Sema &Sem;
 
@@ -2931,12 +2958,12 @@ class Analyzer {
       return nullptr;
     }
 
-    void dump(Sema &S, llvm::raw_ostream &OS) {
+    void dump(Sema &SemaRef, llvm::raw_ostream &OS) {
       OS << "\nAnalysisMap:\n";
       for (const auto &item : *this) {
-        CallableInfo CI(*item.first);
+        CallableInfo CI(SemaRef, *item.first);
         const auto AP = item.second;
-        OS << item.first << " " << CI.name(S) << " : ";
+        OS << item.first << " " << CI.name(SemaRef) << " : ";
         if (AP.isNull()) {
           OS << "null\n";
         } else if (isa<CompleteFunctionAnalysis *>(AP)) {
@@ -2946,7 +2973,7 @@ class Analyzer {
         } else if (isa<PendingFunctionAnalysis *>(AP)) {
           auto *PFA = AP.get<PendingFunctionAnalysis *>();
           OS << PFA << " ";
-          PFA->dump(OS);
+          PFA->dump(SemaRef, OS);
         } else
           llvm_unreachable("never");
       }
@@ -2965,7 +2992,7 @@ class Analyzer {
     // Gather all of the effects to be verified to see what operations need to
     // be checked, and to see which ones are inferrable.
     {
-      for (const CondFunctionEffect &CFE : Sem.AllEffectsToVerify) {
+      for (const FunctionEffectWithCondition &CFE : Sem.AllEffectsToVerify) {
         const FunctionEffect &Effect = CFE.Effect;
         const auto Flags = Effect.flags();
         if (Flags & FunctionEffect::FE_InferrableOnCallees) {
@@ -3036,11 +3063,11 @@ class Analyzer {
   // Verify a single Decl. Return the pending structure if that was the result,
   // else null. This method must not recurse.
   PendingFunctionAnalysis *verifyDecl(const Decl *D) {
-    CallableInfo CInfo(*D);
+    CallableInfo CInfo(Sem, *D);
 
     // If any of the Decl's declared effects forbid throwing (e.g. nonblocking)
     // then the function should also be declared noexcept.
-    for (const auto &Effect : CInfo.Effects) {
+    for (const auto &Effect : CInfo.Effects.EffectsPresent) {
       if (!(Effect.flags() & FunctionEffect::FE_ExcludeThrow))
         continue;
 
@@ -3070,7 +3097,7 @@ class Analyzer {
 
     if constexpr (DebugLogLevel > 0) {
       llvm::outs() << "\nVerifying " << CInfo.name(Sem) << " ";
-      FAnalysis.dump(llvm::outs());
+      FAnalysis.dump(Sem, llvm::outs());
     }
 
     FunctionBodyASTVisitor Visitor(*this, FAnalysis, CInfo);
@@ -3098,7 +3125,7 @@ class Analyzer {
       emitDiagnostics(*Diags, CInfo, Sem);
     }
     auto *CompletePtr = new CompleteFunctionAnalysis(
-        Sem.getASTContext(), Pending, CInfo.Effects,
+        Sem.getASTContext(), Pending, CInfo.Effects.EffectsPresent,
         AllInferrableEffectsToVerify);
     DeclAnalysis[CInfo.CDecl] = CompletePtr;
     if constexpr (DebugLogLevel > 0) {
@@ -3111,17 +3138,17 @@ class Analyzer {
   // not. Generally replicates FunctionBodyASTVisitor::followCall() but without
   // the possibility of inference.
   void finishPendingAnalysis(const Decl *D, PendingFunctionAnalysis *Pending) {
-    CallableInfo Caller(*D);
+    CallableInfo Caller(Sem, *D);
     if constexpr (DebugLogLevel > 0) {
       llvm::outs() << "finishPendingAnalysis for " << Caller.name(Sem) << " : ";
-      Pending->dump(llvm::outs(), &Sem);
+      Pending->dump(Sem, llvm::outs());
       llvm::outs() << "\n";
     }
     for (const auto &Call : Pending->unverifiedCalls()) {
       if (Call.recursed())
         continue;
 
-      CallableInfo Callee(*Call.callee());
+      CallableInfo Callee(Sem, *Call.callee());
       followCall(Caller, *Pending, Callee, Call.CallLoc,
                  /*AssertNoFurtherInference=*/true);
     }
@@ -3137,7 +3164,7 @@ class Analyzer {
     const bool DirectCall = Callee.isDirectCall();
 
     // These will be its declared effects.
-    EffectSet CalleeEffects = Callee.Effects;
+    EffectSet CalleeEffects = Callee.Effects.EffectsPresent;
 
     bool IsInferencePossible = DirectCall;
 
@@ -3180,7 +3207,7 @@ class Analyzer {
           if (Callee.FuncType == SpecialFuncType::None) {
             PFA.checkAddDiagnostic(
                 Inferring,
-                {Effect, DiagnosticID::CallsUnsafeDecl, CallLoc, Callee.CDecl});
+                {Effect, DiagnosticID::CallsDeclWithoutEffect, CallLoc, Callee.CDecl});
           } else {
             PFA.checkAddDiagnostic(
                 Inferring, {Effect, DiagnosticID::AllocatesMemory, CallLoc});
@@ -3226,7 +3253,7 @@ class Analyzer {
       StringRef effectName = Diag.Effect.name();
       switch (Diag.ID) {
       case DiagnosticID::None:
-      case DiagnosticID::DeclWithoutConstraintOrInference: // shouldn't happen
+      case DiagnosticID::DeclDisallowsInference: // shouldn't happen
                                                            // here
         llvm_unreachable("Unexpected diagnostic kind");
         break;
@@ -3253,17 +3280,17 @@ class Analyzer {
         S.Diag(Diag.Loc, diag::warn_func_effect_calls_objc) << effectName;
         checkAddTemplateNote(CInfo.CDecl);
         break;
-      case DiagnosticID::CallsDisallowedExpr:
-        S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_expr)
+      case DiagnosticID::CallsExprWithoutEffect:
+        S.Diag(Diag.Loc, diag::warn_func_effect_calls_expr_without_effect)
             << effectName;
         checkAddTemplateNote(CInfo.CDecl);
         break;
 
-      case DiagnosticID::CallsUnsafeDecl: {
-        CallableInfo CalleeInfo{*Diag.Callee};
+      case DiagnosticID::CallsDeclWithoutEffect: {
+        CallableInfo CalleeInfo(S, *Diag.Callee);
         auto CalleeName = CalleeInfo.name(S);
 
-        S.Diag(Diag.Loc, diag::warn_func_effect_calls_disallowed_func)
+        S.Diag(Diag.Loc, diag::warn_func_effect_calls_func_without_effect)
             << effectName << CalleeName;
         checkAddTemplateNote(CInfo.CDecl);
 
@@ -3284,6 +3311,9 @@ class Analyzer {
               S.Diag(Callee->getLocation(),
                      diag::note_func_effect_call_func_ptr)
                   << effectName;
+            } else if (CalleeInfo.Effects.EffectsExplicitlyAbsent.contains(Diag.Effect)) {
+              S.Diag(Callee->getLocation(), diag::note_func_effect_call_disallows_inference)
+                << effectName;
             } else {
               S.Diag(Callee->getLocation(), diag::note_func_effect_call_extern)
                   << effectName;
@@ -3300,11 +3330,11 @@ class Analyzer {
           case DiagnosticID::None:
             llvm_unreachable("Unexpected diagnostic kind");
             break;
-          case DiagnosticID::DeclWithoutConstraintOrInference:
-            S.Diag(Diag2.Loc, diag::note_func_effect_call_not_inferrable)
+          case DiagnosticID::DeclDisallowsInference:
+            S.Diag(Diag2.Loc, diag::note_func_effect_call_disallows_inference)
                 << effectName;
             break;
-          case DiagnosticID::CallsDisallowedExpr:
+          case DiagnosticID::CallsExprWithoutEffect:
             S.Diag(Diag2.Loc, diag::note_func_effect_call_func_ptr)
                 << effectName;
             break;
@@ -3327,9 +3357,9 @@ class Analyzer {
           case DiagnosticID::CallsObjC:
             S.Diag(Diag2.Loc, diag::note_func_effect_calls_objc) << effectName;
             break;
-          case DiagnosticID::CallsUnsafeDecl:
-            MaybeNextCallee.emplace(*Diag2.Callee);
-            S.Diag(Diag2.Loc, diag::note_func_effect_calls_disallowed_func)
+          case DiagnosticID::CallsDeclWithoutEffect:
+            MaybeNextCallee.emplace(S, *Diag2.Callee);
+            S.Diag(Diag2.Loc, diag::note_func_effect_calls_func_without_effect)
                 << effectName << MaybeNextCallee->name(S);
             break;
           }
@@ -3444,15 +3474,16 @@ class Analyzer {
       auto *FPT =
           CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
       EffectSet CalleeFX;
-      if (FPT)
-        CalleeFX.insertIgnoringConditions(FPT->getFunctionEffects());
-      static_assert(sizeof(FunctionEffect) == 1);
+      if (FPT) {
+        CondEffectSet CFE(Outer.Sem, FPT->getFunctionEffects());
+        CalleeFX.insert(CFE.EffectsPresent);
+      }
 
       auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
         if (FPT == nullptr || Effect.shouldDiagnoseFunctionCall(
                                   /*direct=*/false, CalleeFX)) {
           addDiagnosticInner(Inferring, Effect,
-                             DiagnosticID::CallsDisallowedExpr,
+                             DiagnosticID::CallsExprWithoutEffect,
                              Call->getBeginLoc());
         }
       };
@@ -3495,7 +3526,7 @@ class Analyzer {
       if (Ty->isRecordType()) {
         if (const CXXRecordDecl *Class = Ty->getAsCXXRecordDecl()) {
           if (auto *Dtor = Class->getDestructor()) {
-            CallableInfo CI{*Dtor};
+            CallableInfo CI(Outer.Sem, *Dtor);
             followCall(CI, Dtor->getLocation());
           }
         }
@@ -3541,7 +3572,7 @@ class Analyzer {
 
       Expr *CalleeExpr = Call->getCallee();
       if (const Decl *Callee = CalleeExpr->getReferencedDeclOfCallee()) {
-        CallableInfo CI(*Callee);
+        CallableInfo CI(Outer.Sem, *Callee);
         followCall(CI, Call->getBeginLoc());
         return Proceed;
       }
@@ -3587,7 +3618,7 @@ class Analyzer {
           if (const auto *CxxRec =
                   dyn_cast<CXXRecordDecl>(ClsType->getDecl())) {
             if (const auto *Dtor = CxxRec->getDestructor()) {
-              CallableInfo CI(*Dtor);
+              CallableInfo CI(Outer.Sem, *Dtor);
               followCall(CI, Var->getLocation());
             }
           }
@@ -3600,7 +3631,7 @@ class Analyzer {
       // BUG? It seems incorrect that RecursiveASTVisitor does not
       // visit the call to operator new.
       if (auto *FD = New->getOperatorNew()) {
-        CallableInfo CI(*FD, SpecialFuncType::OperatorNew);
+        CallableInfo CI(Outer.Sem, *FD, SpecialFuncType::OperatorNew);
         followCall(CI, New->getBeginLoc());
       }
 
@@ -3616,7 +3647,7 @@ class Analyzer {
       // BUG? It seems incorrect that RecursiveASTVisitor does not
       // visit the call to operator delete.
       if (auto *FD = Delete->getOperatorDelete()) {
-        CallableInfo CI(*FD, SpecialFuncType::OperatorDelete);
+        CallableInfo CI(Outer.Sem, *FD, SpecialFuncType::OperatorDelete);
         followCall(CI, Delete->getBeginLoc());
       }
 
@@ -3636,7 +3667,7 @@ class Analyzer {
       // BUG? It seems incorrect that RecursiveASTVisitor does not
       // visit the call to the constructor.
       const CXXConstructorDecl *Ctor = Construct->getConstructor();
-      CallableInfo CI(*Ctor);
+      CallableInfo CI(Outer.Sem, *Ctor);
       followCall(CI, Construct->getLocation());
 
       return Proceed;
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index e134822132f6a0..b7cbb2524d7484 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -175,8 +175,6 @@ static void diagnoseBadTypeAttribute(Sema &S, const ParsedAttr &attr,
   case ParsedAttr::AT_TypeNullableResult:                                      \
   case ParsedAttr::AT_TypeNullUnspecified
 
-enum class BoolAttrState : uint8_t { Unseen, False, True, Dependent };
-
 namespace {
   /// An object which stores processing state for the entire
   /// GetTypeForDeclarator process.
@@ -220,15 +218,15 @@ namespace {
     // nonallocating(cond). Manual logic for finding previous attributes would
     // be more complex, unless we transformed nonblocking/nonallocating(false)
     // into distinct separate attributes from the ones which are parsed.
-    BoolAttrState parsedNonBlocking : 2;
-    BoolAttrState parsedNonAllocating : 2;
+    FunctionEffectMode parsedNonBlocking : 2;
+    FunctionEffectMode parsedNonAllocating : 2;
 
   public:
     TypeProcessingState(Sema &sema, Declarator &declarator)
         : sema(sema), declarator(declarator),
           chunkIndex(declarator.getNumTypeObjects()), parsedNoDeref(false),
-          parsedNonBlocking(BoolAttrState::Unseen),
-          parsedNonAllocating(BoolAttrState::Unseen) {}
+          parsedNonBlocking(FunctionEffectMode::None),
+          parsedNonAllocating(FunctionEffectMode::None) {}
 
     Sema &getSema() const {
       return sema;
@@ -355,10 +353,10 @@ namespace {
 
     bool didParseNoDeref() const { return parsedNoDeref; }
 
-    void setParsedNonBlocking(BoolAttrState v) { parsedNonBlocking = v; }
-    BoolAttrState getParsedNonBlocking() const { return parsedNonBlocking; }
-    void setParsedNonAllocating(BoolAttrState v) { parsedNonAllocating = v; }
-    BoolAttrState getParsedNonAllocating() const { return parsedNonAllocating; }
+    void setParsedNonBlocking(FunctionEffectMode v) { parsedNonBlocking = v; }
+    FunctionEffectMode getParsedNonBlocking() const { return parsedNonBlocking; }
+    void setParsedNonAllocating(FunctionEffectMode v) { parsedNonAllocating = v; }
+    FunctionEffectMode getParsedNonAllocating() const { return parsedNonAllocating; }
 
     ~TypeProcessingState() {
       if (savedAttrs.empty())
@@ -7979,6 +7977,34 @@ static Attr *getCCTypeAttr(ASTContext &Ctx, ParsedAttr &Attr) {
   llvm_unreachable("unexpected attribute kind!");
 }
 
+ExprResult Sema::ActOnEffectExpression(Expr *CondExpr, FunctionEffectMode &Mode, bool RequireConstexpr)
+{
+  // see checkFunctionConditionAttr, Sema::CheckCXXBooleanCondition
+  if (RequireConstexpr || !CondExpr->isTypeDependent()) {
+    ExprResult E = PerformContextuallyConvertToBool(CondExpr);
+    if (E.isInvalid())
+      return E;
+    CondExpr = E.get();
+    if (RequireConstexpr || !CondExpr->isValueDependent()) {
+      llvm::APSInt CondInt;
+      E = VerifyIntegerConstantExpression(
+          E.get(), &CondInt,
+          // TODO: have our own diagnostic
+          diag::err_constexpr_if_condition_expression_is_not_constant);
+      if (E.isInvalid()) {
+        return E;
+      }
+      Mode =
+          (CondInt != 0) ? FunctionEffectMode::True : FunctionEffectMode::False;
+    } else {
+      Mode = FunctionEffectMode::Dependent;
+    }
+  } else {
+    Mode = FunctionEffectMode::Dependent;
+  }
+  return CondExpr;
+}
+
 static bool
 handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
                                        ParsedAttr &PAttr, QualType &QT,
@@ -8000,60 +8026,41 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
                              PAttr.getKind() == ParsedAttr::AT_Blocking;
   Sema &S = TPState.getSema();
 
-  BoolAttrState NewState = BoolAttrState::Unseen;
+  FunctionEffectMode NewState = FunctionEffectMode::None;
   Expr *CondExpr = nullptr; // only valid if dependent
 
   if (PAttr.getKind() == ParsedAttr::AT_NonBlocking ||
       PAttr.getKind() == ParsedAttr::AT_NonAllocating) {
     // Parse the conditional expression, if any
     if (PAttr.getNumArgs() > 0) {
-      // see checkFunctionConditionAttr, Sema::CheckCXXBooleanCondition
       CondExpr = PAttr.getArgAsExpr(0);
-      if (!CondExpr->isTypeDependent()) {
-        ExprResult E = S.PerformContextuallyConvertToBool(CondExpr);
-        if (E.isInvalid())
-          return false;
-        CondExpr = E.get();
-        if (!CondExpr->isValueDependent()) {
-          llvm::APSInt CondInt;
-          E = S.VerifyIntegerConstantExpression(
-              E.get(), &CondInt,
-              // TODO: have our own diagnostic
-              diag::err_constexpr_if_condition_expression_is_not_constant);
-          if (E.isInvalid()) {
-            return false;
-          }
-          NewState =
-              (CondInt != 0) ? BoolAttrState::True : BoolAttrState::False;
-        } else {
-          NewState = BoolAttrState::Dependent;
-        }
-      } else {
-        NewState = BoolAttrState::Dependent;
-      }
+      ExprResult E = S.ActOnEffectExpression(CondExpr, NewState);
+      if (E.isInvalid())
+        return false;
+      CondExpr = E.get();
     } else {
-      NewState = BoolAttrState::True;
+      NewState = FunctionEffectMode::True;
     }
   } else {
     // This is the `blocking` or `allocating` attribute.
-    NewState = BoolAttrState::False;
+    NewState = FunctionEffectMode::False;
   }
 
-  auto attrName = [](bool NB, BoolAttrState value) {
+  auto attrName = [](bool NB, FunctionEffectMode value) {
     switch (value) {
-    case BoolAttrState::False:
+    case FunctionEffectMode::False:
       return NB ? "blocking" : "allocating";
-    case BoolAttrState::True:
+    case FunctionEffectMode::True:
       return NB ? "nonblocking" : "nonallocating";
-    case BoolAttrState::Dependent:
+    case FunctionEffectMode::Dependent:
       return NB ? "nonblocking(expr)" : "nonallocating(expr)";
     default:
-      llvm_unreachable("'unseen' shouldn't happen");
+      llvm_unreachable("'FunctionEffectMode::None' shouldn't happen");
     }
   };
 
   // Diagnose the newly provided attribute as incompatible with a previous one.
-  auto incompatible = [&](bool prevNB, BoolAttrState prevValue) {
+  auto incompatible = [&](bool prevNB, FunctionEffectMode prevValue) {
     S.Diag(PAttr.getLoc(), diag::err_attributes_are_not_compatible)
         << attrName(isNonBlocking, NewState) << attrName(prevNB, prevValue)
         << false;
@@ -8063,32 +8070,32 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
     return true;
   };
 
-  const BoolAttrState PrevState = isNonBlocking
+  const FunctionEffectMode PrevState = isNonBlocking
                                       ? TPState.getParsedNonBlocking()
                                       : TPState.getParsedNonAllocating();
-  if (PrevState != BoolAttrState::Unseen) {
+  if (PrevState != FunctionEffectMode::None) {
     // Only one attribute per constraint is allowed.
     return incompatible(isNonBlocking, PrevState);
   }
 
   if (isNonBlocking) {
     // also check nonblocking(true) against allocating
-    if (NewState == BoolAttrState::True &&
-        TPState.getParsedNonAllocating() == BoolAttrState::False) {
-      return incompatible(false, BoolAttrState::False);
+    if (NewState == FunctionEffectMode::True &&
+        TPState.getParsedNonAllocating() == FunctionEffectMode::False) {
+      return incompatible(false, FunctionEffectMode::False);
     }
     TPState.setParsedNonBlocking(NewState);
   } else {
     // also check nonblocking(true) against allocating
-    if (TPState.getParsedNonBlocking() == BoolAttrState::True) {
-      if (NewState == BoolAttrState::False) {
-        return incompatible(true, BoolAttrState::True);
+    if (TPState.getParsedNonBlocking() == FunctionEffectMode::True) {
+      if (NewState == FunctionEffectMode::False) {
+        return incompatible(true, FunctionEffectMode::True);
       }
     }
     TPState.setParsedNonAllocating(NewState);
   }
 
-  if (NewState == BoolAttrState::False) {
+  if (NewState == FunctionEffectMode::False) {
     // blocking and allocating are represented as AttributedType sugar,
     // using those attributes.
     Attr *A = nullptr;
@@ -8109,7 +8116,7 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
 
   FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
   FunctionEffectSet FX(EPI.FunctionEffects);
-  FX.insert(NewEffect, NewState == BoolAttrState::Dependent ? CondExpr : nullptr);
+  FX.insert(NewEffect, NewState == FunctionEffectMode::Dependent ? CondExpr : nullptr);
   EPI.FunctionEffects = FunctionEffectsRef(FX);
 
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index a2568ad0f82cc2..c8816d6651e6df 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -6234,6 +6234,59 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
     EPI.ExtParameterInfos = nullptr;
   }
 
+#define XFORM_FALSE_FX_TO_SUGAR 0
+
+  // Transform any function effects with unevaluated conditions.
+  // Hold this set in a local for the rest of this function, since EPI
+  // is going to hold a FunctionEffectsRef pointing into it.
+  std::optional <FunctionEffectSet> NewFX;
+#if XFORM_FALSE_FX_TO_SUGAR
+  SmallVector<Attr *> TypeAttrsToAdd;
+#endif
+  if (ArrayRef FXConds = EPI.FunctionEffects.conditions(); !FXConds.empty()) {
+    NewFX.emplace(EPI.FunctionEffects);
+    EnterExpressionEvaluationContext Unevaluated(
+        getSema(), Sema::ExpressionEvaluationContext::ConstantEvaluated);
+
+    for (unsigned Idx = 0, Count = FXConds.size(); Idx != Count; ) {
+      if (Expr *CondExpr = FXConds[Idx].expr()) {
+        ExprResult NewExpr = getDerived().TransformExpr(CondExpr);
+        if (NewExpr.isInvalid())
+          return QualType();
+        FunctionEffectMode Mode = FunctionEffectMode::None;
+        NewExpr = SemaRef.ActOnEffectExpression(NewExpr.get(), Mode);
+        if (NewExpr.isInvalid())
+          return QualType();
+
+#if XFORM_FALSE_FX_TO_SUGAR
+        if (Mode == FunctionEffectMode::False) {
+          NewFX->erase(Idx);
+          --Count;
+          const FunctionEffect Effect(EPI.FunctionEffects.effects()[Idx]);
+          if (Effect.kind() == FunctionEffect::Kind::NonAllocating) {
+            TypeAttrsToAdd.push_back(AllocatingAttr::Create(SemaRef.Context));
+          } else if (Effect.kind() == FunctionEffect::Kind::NonBlocking) {
+            TypeAttrsToAdd.push_back(BlockingAttr::Create(SemaRef.Context));
+          }
+          continue;
+        }
+        assert(Mode == FunctionEffectMode::True);
+        NewFX->replaceCondition(Idx, NewExpr.get());
+#else
+        // The condition expression has been transformed, and re-evaluated.
+        // If it is now a constant of 'true', we can discard it because a null
+        // condition in FunctionEffectSet means true. If the expression is still
+        //  dependent or constant 'false', just propagate it into the new EPI.
+        FunctionEffectCondition Cond(Mode == FunctionEffectMode::True ? nullptr : NewExpr.get());
+        NewFX->replaceCondition(Idx, Cond.expr());
+#endif
+      }
+      ++Idx;
+    }
+    EPI.FunctionEffects = *NewFX;
+    EPIChanged = true;
+  }
+
   QualType Result = TL.getType();
   if (getDerived().AlwaysRebuild() || ResultType != T->getReturnType() ||
       T->getParamTypes() != llvm::ArrayRef(ParamTypes) || EPIChanged) {
@@ -6251,6 +6304,20 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
   for (unsigned i = 0, e = NewTL.getNumParams(); i != e; ++i)
     NewTL.setParam(i, ParamDecls[i]);
 
+#if XFORM_FALSE_FX_TO_SUGAR
+  // This creates problems because the caller assumes FunctionProtoType will
+  // be transformed to FunctionProtoType.
+  if (!TypeAttrsToAdd.empty()) {
+    for (Attr *A : TypeAttrsToAdd) {
+      QualType QT = SemaRef.Context.getAttributedType(A->getKind(), Result, Result);
+      llvm::outs() << "transformed " << Result << " -> " << QT;
+      Result = QT;
+      AttributedTypeLoc ATL = TLB.push<AttributedTypeLoc>(Result);
+      ATL.setAttr(A);
+    }
+  }
+#endif
+
   return Result;
 }
 

>From 0aa20af28bedb737c842215d56b9312f2e16106c Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Tue, 23 Apr 2024 12:55:12 -0700
Subject: [PATCH 37/40] - Inline the methods on Decl. - Groundwork for a
 canonical representation of "denied" effects (e.g. nonblocking(false))

---
 clang/include/clang/AST/AbstractBasicReader.h |   4 +-
 clang/include/clang/AST/AbstractBasicWriter.h |   4 +-
 clang/include/clang/AST/Decl.h                |  17 +-
 clang/include/clang/AST/Type.h                | 153 ++++++++------
 clang/include/clang/Basic/DiagnosticGroups.td |   1 +
 .../clang/Basic/DiagnosticSemaKinds.td        |  31 +--
 clang/include/clang/Sema/Sema.h               |   9 +-
 clang/lib/AST/Decl.cpp                        |  20 --
 clang/lib/AST/Type.cpp                        | 198 ++++++++++--------
 clang/lib/Sema/AnalysisBasedWarnings.cpp      |  67 +++---
 clang/lib/Sema/Sema.cpp                       |  12 +-
 clang/lib/Sema/SemaDecl.cpp                   |  13 +-
 clang/lib/Sema/SemaDeclCXX.cpp                |  40 ++--
 clang/lib/Sema/SemaType.cpp                   |  30 ++-
 clang/lib/Sema/TreeTransform.h                |  10 +-
 clang/lib/Serialization/ASTReader.cpp         |   2 +-
 16 files changed, 304 insertions(+), 307 deletions(-)

diff --git a/clang/include/clang/AST/AbstractBasicReader.h b/clang/include/clang/AST/AbstractBasicReader.h
index f3418222780197..71bb40587bacc7 100644
--- a/clang/include/clang/AST/AbstractBasicReader.h
+++ b/clang/include/clang/AST/AbstractBasicReader.h
@@ -245,10 +245,8 @@ class DataStreamBasicReader : public BasicReaderBase<Impl> {
   }
 
   FunctionEffect readFunctionEffect() {
-    static_assert(sizeof(FunctionEffect::Kind) <= sizeof(uint32_t),
-                  "update this if size changes");
     uint32_t value = asImpl().readUInt32();
-    return FunctionEffect(static_cast<FunctionEffect::Kind>(value));
+    return FunctionEffect::fromOpaqueInt32(value);
   }
 
   FunctionEffectCondition readFunctionEffectCondition() {
diff --git a/clang/include/clang/AST/AbstractBasicWriter.h b/clang/include/clang/AST/AbstractBasicWriter.h
index c6a5748bfbb1b1..5b5fca0fd4d97a 100644
--- a/clang/include/clang/AST/AbstractBasicWriter.h
+++ b/clang/include/clang/AST/AbstractBasicWriter.h
@@ -223,9 +223,7 @@ class DataStreamBasicWriter : public BasicWriterBase<Impl> {
   }
 
   void writeFunctionEffect(FunctionEffect E) {
-    static_assert(sizeof(FunctionEffect::Kind) <= sizeof(uint32_t),
-                  "update this if the value size changes");
-    asImpl().writeUInt32(llvm::to_underlying(E.kind()));
+    asImpl().writeUInt32(E.toOpaqueInt32());
   }
 
   void writeFunctionEffectCondition(FunctionEffectCondition CE) {
diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index 6d4f9a3c02c1f9..d097b6a92c739a 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -3008,7 +3008,15 @@ class FunctionDecl : public DeclaratorDecl,
   /// computed and stored.
   unsigned getODRHash() const;
 
-  FunctionEffectsRef getFunctionEffects() const;
+  FunctionEffectsRef getFunctionEffects() const {
+    // Effects may differ between declarations, but they should be propagated
+    // from old to new on any redeclaration, so it suffices to look at
+    // getMostRecentDecl().
+    if (const auto *FPT =
+            getMostRecentDecl()->getType()->getAs<FunctionProtoType>())
+      return FPT->getFunctionEffects();
+    return {};
+  }
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
@@ -4635,7 +4643,12 @@ class BlockDecl : public Decl, public DeclContext {
 
   SourceRange getSourceRange() const override LLVM_READONLY;
 
-  FunctionEffectsRef getFunctionEffects() const;
+  FunctionEffectsRef getFunctionEffects() const {
+    if (TypeSourceInfo *TSI = getSignatureAsWritten())
+      if (auto *FPT = TSI->getType()->getAs<FunctionProtoType>())
+        return FPT->getFunctionEffects();
+    return {};
+  }
 
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 5f003f6e4ecc13..3003d504bdb31b 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4438,34 +4438,20 @@ class FunctionNoProtoType : public FunctionType, public llvm::FoldingSetNode {
 
 class Decl;
 class CXXMethodDecl;
+struct FunctionEffectDiff;
 class FunctionEffectsRef;
 class FunctionEffectSet;
 
-/*
-  TODO: Idea about how to move most of the FunctionEffect business out of
-  Type.h, thus removing these forward declarations.
-
-  - Keep FunctionEffect itself here but make it more minimal. Don't define flags
-  or any behaviors, just the Kind and an accessor.
-  - Keep FunctionEffectCondition here.
-  - Make FunctionProtoType and ExtProtoInfo use only ArrayRef<FunctionEffect>
-  and ArrayRef<FunctionEffectCondition>.
-  - Somewhere in Sema, define ExtFunctionEffect, which holds a FunctionEffect
-    and has all the behavior-related methods.
-  - There too, define the containers. FunctionEffectsRef can have a
-  constructor or factory method that initializes itself from a
-  FunctionProtoType.
-*/
-
 /// Represents an abstract function effect, using just an enumeration describing
-/// its kind.
+/// its kind and a bool "denied", which indicates that the effect is asserted
+/// NOT to apply (preventing inference of the effect).
 class FunctionEffect {
 public:
   /// Identifies the particular effect.
   enum class Kind : uint8_t {
-    None,
-    NonBlocking,
-    NonAllocating,
+    None = 0,
+    NonBlocking = 1,
+    NonAllocating = 2,
   };
 
   /// Flags describing some behaviors of the effect.
@@ -4483,32 +4469,38 @@ class FunctionEffect {
     FE_ExcludeThreadLocalVars = 0x20
   };
 
-  /// Describes the result of effects differing between a base class's virtual
-  /// method and an overriding method in a subclass.
-  enum class OverrideResult {
-    Ignore,
-    Warn,
-    Merge // Base method's effects are merged with those of the override.
-  };
-
 private:
-  Kind FKind = Kind::None;
+  LLVM_PREFERRED_TYPE(Kind)
+  unsigned FKind : 2;
+
+  LLVM_PREFERRED_TYPE(bool)
+  unsigned IsDenied : 1;
 
   // Expansion: for hypothetical TCB+types, there could be one Kind for TCB,
   // then ~16(?) bits "SubKind" to map to a specific named TCB. SubKind would
   // be considered for uniqueness.
 
 public:
-  FunctionEffect() = default;
+  FunctionEffect() : FKind(unsigned(Kind::None)), IsDenied(false) {}
 
-  explicit FunctionEffect(Kind K) : FKind(K) {}
+  FunctionEffect(Kind K, bool IsDenied)
+      : FKind(unsigned(K)), IsDenied(IsDenied) {}
 
   /// The kind of the effect.
-  Kind kind() const { return FKind; }
+  Kind kind() const { return Kind(FKind); }
+
+  /// Whether the effect is being denied (as opposed to asserted).
+  bool isDenied() const { return IsDenied; }
+
+  /// For serialization.
+  uint32_t toOpaqueInt32() const { return (FKind << 1) | IsDenied; }
+  static FunctionEffect fromOpaqueInt32(uint32_t Value) {
+    return FunctionEffect(Kind(Value >> 1), Value & 1);
+  }
 
   /// Flags describing some behaviors of the effect.
   Flags flags() const {
-    switch (FKind) {
+    switch (kind()) {
     case Kind::NonBlocking:
       return FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
              FE_ExcludeObjCMessageSend | FE_ExcludeStaticLocalVars |
@@ -4526,28 +4518,6 @@ class FunctionEffect {
   /// The description printed in diagnostics, e.g. 'nonblocking'.
   StringRef name() const;
 
-  /// Return true if adding or removing the effect as part of a type conversion
-  /// should generate a diagnostic.
-  bool shouldDiagnoseConversion(bool Adding, QualType OldType,
-                                const FunctionEffectsRef &OldFX,
-                                QualType NewType,
-                                const FunctionEffectsRef &NewFX) const;
-
-  /// Return true if adding or removing the effect in a redeclaration should
-  /// generate a diagnostic.
-  bool shouldDiagnoseRedeclaration(bool Adding, const FunctionDecl &OldFunction,
-                                   const FunctionEffectsRef &OldFX,
-                                   const FunctionDecl &NewFunction,
-                                   const FunctionEffectsRef &NewFX) const;
-
-  /// Return true if adding or removing the effect in a C++ virtual method
-  /// override should generate a diagnostic.
-  OverrideResult
-  shouldDiagnoseMethodOverride(bool Adding, const CXXMethodDecl &OldMethod,
-                               const FunctionEffectsRef &OldFX,
-                               const CXXMethodDecl &NewMethod,
-                               const FunctionEffectsRef &NewFX) const;
-
   /// Return true if the effect is allowed to be inferred on the callee,
   /// which is either a FunctionDecl or BlockDecl.
   /// This is only used if the effect has FE_InferrableOnCallees flag set.
@@ -4563,7 +4533,7 @@ class FunctionEffect {
                                   ArrayRef<FunctionEffect> CalleeFX) const;
 
   friend bool operator==(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.FKind == RHS.FKind;
+    return LHS.FKind == RHS.FKind && LHS.IsDenied == RHS.IsDenied;
   }
   friend bool operator!=(const FunctionEffect &LHS, const FunctionEffect &RHS) {
     return !(LHS == RHS);
@@ -4571,9 +4541,6 @@ class FunctionEffect {
   friend bool operator<(const FunctionEffect &LHS, const FunctionEffect &RHS) {
     return LHS.FKind < RHS.FKind;
   }
-  friend bool operator>(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.FKind > RHS.FKind;
-  }
 };
 
 /// Wrap a function effect's condition expression in another struct so
@@ -4600,6 +4567,55 @@ struct FunctionEffectWithCondition {
   FunctionEffectCondition Cond;
 };
 
+struct FunctionEffectDiff {
+  enum class Kind {
+    Added,
+    Removed,
+    AssertToDeny,
+    DenyToAssert,
+    ConditionMismatch
+  };
+
+  FunctionEffect::Kind EffectKind;
+  Kind DiffKind;
+  FunctionEffectWithCondition Old; // invalid when Added
+  FunctionEffectWithCondition New; // invalid when Removed
+
+  StringRef effectName() const {
+    if (Old.Effect.kind() != FunctionEffect::Kind::None)
+      return Old.Effect.name();
+    return New.Effect.name();
+  }
+
+  /// Describes the result of effects differing between a base class's virtual
+  /// method and an overriding method in a subclass.
+  enum class OverrideResult {
+    NoAction,
+    Warn,
+    MergeAdded // Merge an added effect
+  };
+
+  /// Return true if adding or removing the effect as part of a type conversion
+  /// should generate a diagnostic.
+  bool shouldDiagnoseConversion(QualType SrcType,
+                                const FunctionEffectsRef &SrcFX,
+                                QualType DstType,
+                                const FunctionEffectsRef &DstFX) const;
+
+  /// Return true if adding or removing the effect in a redeclaration should
+  /// generate a diagnostic.
+  bool shouldDiagnoseRedeclaration(const FunctionDecl &OldFunction,
+                                   const FunctionEffectsRef &OldFX,
+                                   const FunctionDecl &NewFunction,
+                                   const FunctionEffectsRef &NewFX) const;
+
+  /// Return true if adding or removing the effect in a C++ virtual method
+  /// override should generate a diagnostic.
+  OverrideResult shouldDiagnoseMethodOverride(
+      const CXXMethodDecl &OldMethod, const FunctionEffectsRef &OldFX,
+      const CXXMethodDecl &NewMethod, const FunctionEffectsRef &NewFX) const;
+};
+
 /// Support iteration in parallel through a pair of FunctionEffect and
 /// FunctionEffectCondition containers.
 template <typename Container> class FunctionEffectIterator {
@@ -4624,7 +4640,8 @@ template <typename Container> class FunctionEffectIterator {
   FunctionEffectWithCondition operator*() const {
     const bool HasConds = !Outer.Conditions.empty();
     return FunctionEffectWithCondition{Outer.Effects[Idx],
-                              HasConds ? Outer.Conditions[Idx] : FunctionEffectCondition()};
+                                       HasConds ? Outer.Conditions[Idx]
+                                                : FunctionEffectCondition()};
   }
 };
 
@@ -4632,6 +4649,8 @@ template <typename Container> class FunctionEffectIterator {
 /// them. The effects and conditions reside in memory not managed by this object
 /// (typically, trailing objects in FunctionProtoType, or borrowed references
 /// from a FunctionEffectSet).
+///
+/// Invariant: there is never more than one instance of any given effect.
 class FunctionEffectsRef {
   ArrayRef<FunctionEffect> Effects;
 
@@ -4677,6 +4696,10 @@ class FunctionEffectsRef {
 
 /// A mutable set of FunctionEffects and possibly conditions attached to them.
 /// Used transitorily within Sema to compare and merge effects on declarations.
+///
+/// Invariant: there is never more than one instance of any given effect. This
+/// is asserted in insert and getUnion; it is the caller's responsibility to
+/// diagnose this.
 class FunctionEffectSet {
   SmallVector<FunctionEffect> Effects;
   // The vector of conditions is either empty or has the same size
@@ -4702,6 +4725,7 @@ class FunctionEffectSet {
   void dump(llvm::raw_ostream &OS) const;
 
   // Mutators
+
   void insert(FunctionEffect Effect, Expr *Cond);
   void insert(const FunctionEffectsRef &Set);
   void insertIgnoringConditions(const FunctionEffectsRef &Set);
@@ -4710,15 +4734,14 @@ class FunctionEffectSet {
   void erase(unsigned Idx);
 
   // Set operations
+  static FunctionEffectSet getUnion(FunctionEffectsRef LHS,
+                                    FunctionEffectsRef RHS);
+
+  using Differences = SmallVector<FunctionEffectDiff>;
 
-  using Differences =
-      SmallVector<std::pair<FunctionEffectWithCondition, /*added=*/bool>>;
   /// Caller should short-circuit by checking for equality first.
   static Differences differences(const FunctionEffectsRef &Old,
                                  const FunctionEffectsRef &New);
-
-  static FunctionEffectSet getUnion(FunctionEffectsRef LHS,
-                                    FunctionEffectsRef RHS);
 };
 
 /// Represents a prototype with parameter type info, e.g.
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index a56df9a89375f7..45e90af7dc0e87 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -1521,3 +1521,4 @@ def PerfConstraintImpliesNoexcept : DiagGroup<"perf-constraint-implies-noexcept"
 
 // Warnings and notes InstallAPI verification.
 def InstallAPIViolation : DiagGroup<"installapi-violation">;
+
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 3ce35abc088b08..5e527f397494d6 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -10798,73 +10798,52 @@ def warn_imp_cast_drops_unaligned : Warning<
   "implicit cast from type %0 to type %1 drops __unaligned qualifier">,
   InGroup<DiagGroup<"unaligned-qualifier-implicit-cast">>;
 
+// Function effects
 def warn_func_effect_allocates : Warning<
   "'%0' function must not allocate or deallocate memory">,
   InGroup<FunctionEffects>;
-
 def note_func_effect_allocates : Note<
   "function cannot be inferred '%0' because it allocates/deallocates memory">;
-
 def warn_func_effect_throws_or_catches : Warning<
   "'%0' function must not throw or catch exceptions">,
   InGroup<FunctionEffects>;
-
 def note_func_effect_throws_or_catches : Note<
   "function cannot be inferred '%0' because it throws or catches exceptions">;
-
 def warn_func_effect_has_static_local : Warning<
   "'%0' function must not have static locals">,
   InGroup<FunctionEffects>;
-
 def note_func_effect_has_static_local : Note<
   "function cannot be inferred '%0' because it has a static local">;
-
 def warn_func_effect_uses_thread_local : Warning<
   "'%0' function must not use thread-local variables">,
   InGroup<FunctionEffects>;
-
 def note_func_effect_uses_thread_local : Note<
   "function cannot be inferred '%0' because it uses a thread-local variable">;
-
 def warn_func_effect_calls_objc : Warning<
   "'%0' function must not access an ObjC method or property">,
   InGroup<FunctionEffects>;
-
 def note_func_effect_calls_objc : Note<
   "function cannot be inferred '%0' because it accesses an ObjC method or property">;
-
 def warn_func_effect_calls_func_without_effect : Warning<
   "'%0' function must not call non-'%0' function '%1'">,
   InGroup<FunctionEffects>;
-
 def warn_func_effect_calls_expr_without_effect : Warning<
   "'%0' function must not call non-'%0' expression">,
   InGroup<FunctionEffects>;
-
 def note_func_effect_calls_func_without_effect : Note<
   "function cannot be inferred '%0' because it calls non-'%0' function '%1'">;
-
 def note_func_effect_call_extern : Note<
   "function cannot be inferred '%0' because it has no definition in this translation unit">;
-
 def note_func_effect_call_disallows_inference : Note<
   "function does not permit inference of '%0'">;
-
 def note_func_effect_call_virtual : Note<
   "virtual method cannot be inferred '%0'">;
-
 def note_func_effect_call_func_ptr : Note<
   "function pointer cannot be inferred '%0'">;
-
 def warn_perf_constraint_implies_noexcept : Warning<
   "'%0' function should be declared noexcept">,
   InGroup<PerfConstraintImpliesNoexcept>;
 
-// TODO: Not currently being generated
-def warn_func_effect_false_on_type : Warning<
-  "only functions/methods/blocks may be declared %0(false)">,
-  InGroup<FunctionEffects>;
-
 // TODO: can the usual template expansion notes be used?
 def note_func_effect_from_template : Note<
   "in template expansion here">;
@@ -10873,15 +10852,9 @@ def note_func_effect_from_template : Note<
 def warn_invalid_add_func_effects : Warning<
   "attribute '%0' should not be added via type conversion">,
   InGroup<FunctionEffects>;
-
-def warn_invalid_remove_func_effects : Warning<
-  "attribute '%0' should not be removed via type conversion">,
-  InGroup<FunctionEffects>;
-
 def warn_mismatched_func_effect_override : Warning<
-  "attribute '%0' on overriding function does not match base version">,
+  "attribute '%0' on overriding function does not match base declaration">,
   InGroup<FunctionEffects>;
-
 def warn_mismatched_func_effect_redeclaration : Warning<
   "attribute '%0' on function does not match previous declaration">,
   InGroup<FunctionEffects>;
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 5b417870a9ebbe..abce9e5edff24d 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -421,7 +421,7 @@ enum class TemplateDeductionResult {
 };
 
 /// Used with attributes/effects with a boolean condition, e.g. `nonblocking`.
-enum class FunctionEffectMode {
+enum class FunctionEffectMode : uint8_t {
   None,     // effect is not present
   False,    // effect(false)
   True,     // effect(true)
@@ -964,11 +964,14 @@ class Sema final {
   /// Potentially add a FunctionDecl or BlockDecl to DeclsWithEffectsToVerify.
   void maybeAddDeclWithEffects(const Decl *D, const FunctionEffectsRef &FX);
 
-  /// Try to parse the conditional expression attached to an effect attribute 
+  /// Unconditionally add a Decl to DeclsWithEfffectsToVerify.
+  void addDeclWithEffects(const Decl *D, const FunctionEffectsRef &FX);
+
+  /// Try to parse the conditional expression attached to an effect attribute
   /// (e.g. 'nonblocking'). (c.f. Sema::ActOnNoexceptSpec). If RequireConstexpr,
   /// then this will fail if the expression is dependent.
   ExprResult ActOnEffectExpression(Expr *CondExpr, FunctionEffectMode &Mode,
-    bool RequireConstexpr = false);
+                                   bool RequireConstexpr = false);
 
   // ----- function effects --- where ?????
 
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 524956ea18678f..131f82985e903b 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -4505,17 +4505,6 @@ unsigned FunctionDecl::getODRHash() {
   return ODRHash;
 }
 
-// Effects may differ between declarations, but they should be propagated from
-// old to new on any redeclaration, so it suffices to look at
-// getMostRecentDecl().
-FunctionEffectsRef FunctionDecl::getFunctionEffects() const {
-  if (const auto *FPT =
-          getMostRecentDecl()->getType()->getAs<FunctionProtoType>()) {
-    return FPT->getFunctionEffects();
-  }
-  return {};
-}
-
 //===----------------------------------------------------------------------===//
 // FieldDecl Implementation
 //===----------------------------------------------------------------------===//
@@ -5240,15 +5229,6 @@ SourceRange BlockDecl::getSourceRange() const {
   return SourceRange(getLocation(), Body ? Body->getEndLoc() : getLocation());
 }
 
-FunctionEffectsRef BlockDecl::getFunctionEffects() const {
-  if (auto *TSI = getSignatureAsWritten()) {
-    if (auto *FPT = TSI->getType()->getAs<FunctionProtoType>()) {
-      return FPT->getFunctionEffects();
-    }
-  }
-  return {};
-}
-
 //===----------------------------------------------------------------------===//
 // Other Decl Allocation/Deallocation Method Implementations
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index bdf6d23eec269f..3702163336baf0 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3654,7 +3654,8 @@ FunctionProtoType::FunctionProtoType(QualType result, ArrayRef<QualType> params,
       auto *DestConds = getTrailingObjects<FunctionEffectCondition>();
       std::copy(SrcConds.begin(), SrcConds.end(), DestConds);
 
-      assert(isCanonicalUnqualified()); // TODO: because I don't understand this yet...
+      assert(isCanonicalUnqualified()); // TODO: because I don't understand this
+                                        // yet...
       addDependence(TypeDependence::DependentInstantiation);
     }
   }
@@ -5053,57 +5054,93 @@ StringRef FunctionEffect::name() const {
   llvm_unreachable("unknown effect kind");
 }
 
-bool FunctionEffect::shouldDiagnoseConversion(
-    bool Adding, QualType OldType, const FunctionEffectsRef &OldFX,
-    QualType NewType, const FunctionEffectsRef &NewFX) const {
+bool FunctionEffectDiff::shouldDiagnoseConversion(
+    QualType SrcType, const FunctionEffectsRef &SrcFX, QualType DstType,
+    const FunctionEffectsRef &DstFX) const {
 
-  switch (kind()) {
-  case Kind::NonAllocating:
+  switch (EffectKind) {
+  case FunctionEffect::Kind::NonAllocating:
     // nonallocating can't be added (spoofed) during a conversion, unless we
     // have nonblocking
-    if (Adding) {
-      for (const auto &CFE : OldFX) {
-        if (CFE.Effect.kind() == Kind::NonBlocking)
+    if (DiffKind == Kind::Added) {
+      for (const auto &CFE : SrcFX) {
+        if (CFE.Effect.kind() == FunctionEffect::Kind::NonBlocking)
           return false;
       }
     }
     [[fallthrough]];
-  case Kind::NonBlocking:
-    // nonblocking can't be added (spoofed) during a conversion
-    return Adding;
-  case Kind::None:
+  case FunctionEffect::Kind::NonBlocking:
+    // nonblocking can't be added (spoofed) during a conversion.
+    switch (DiffKind) {
+    case Kind::Added:
+      return true;
+    case Kind::Removed:
+      return false;
+    case Kind::AssertToDeny:
+      // effect asserted -> denied: no diagnostic.
+      return false;
+    case Kind::DenyToAssert:
+      // effect denied -> asserted: diagnose.
+      return true;
+    case Kind::ConditionMismatch:
+      return true; // TODO: ???
+    }
+  case FunctionEffect::Kind::None:
     break;
   }
   llvm_unreachable("unknown effect kind");
 }
 
-bool FunctionEffect::shouldDiagnoseRedeclaration(
-    bool Adding, const FunctionDecl &OldFunction,
-    const FunctionEffectsRef &OldFX, const FunctionDecl &NewFunction,
-    const FunctionEffectsRef &NewFX) const {
-  switch (kind()) {
-  case Kind::NonAllocating:
-  case Kind::NonBlocking:
+bool FunctionEffectDiff::shouldDiagnoseRedeclaration(
+    const FunctionDecl &OldFunction, const FunctionEffectsRef &OldFX,
+    const FunctionDecl &NewFunction, const FunctionEffectsRef &NewFX) const {
+  switch (EffectKind) {
+  case FunctionEffect::Kind::NonAllocating:
+  case FunctionEffect::Kind::NonBlocking:
     // nonblocking/nonallocating can't be removed in a redeclaration
-    // adding -> false, removing -> true (diagnose)
-    return !Adding;
-  case Kind::None:
+    switch (DiffKind) {
+    case Kind::Added:
+      return false; // No diagnostic.
+    case Kind::Removed:
+      return true; // Issue diagnostic
+    case Kind::DenyToAssert:
+    case Kind::AssertToDeny:
+    case Kind::ConditionMismatch:
+      // All these forms of mismatches are diagnosed.
+      return true;
+    }
+  case FunctionEffect::Kind::None:
     break;
   }
   llvm_unreachable("unknown effect kind");
 }
 
-FunctionEffect::OverrideResult FunctionEffect::shouldDiagnoseMethodOverride(
-    bool Adding, const CXXMethodDecl &OldMethod,
-    const FunctionEffectsRef &OldFX, const CXXMethodDecl &NewMethod,
-    const FunctionEffectsRef &NewFX) const {
-  switch (kind()) {
-  case Kind::NonAllocating:
-  case Kind::NonBlocking:
-    // if added on an override, that's fine and not diagnosed.
-    // if missing from an override (removed), propagate from base to derived.
-    return Adding ? OverrideResult::Ignore : OverrideResult::Merge;
-  case Kind::None:
+FunctionEffectDiff::OverrideResult
+FunctionEffectDiff::shouldDiagnoseMethodOverride(
+    const CXXMethodDecl &OldMethod, const FunctionEffectsRef &OldFX,
+    const CXXMethodDecl &NewMethod, const FunctionEffectsRef &NewFX) const {
+  switch (EffectKind) {
+  case FunctionEffect::Kind::NonAllocating:
+  case FunctionEffect::Kind::NonBlocking:
+    switch (DiffKind) {
+
+    // If added on an override, that's fine and not diagnosed.
+    case Kind::Added:
+      return OverrideResult::NoAction;
+
+    // If missing from an override (removed), propagate from base to derived.
+    case Kind::Removed:
+      return OverrideResult::MergeAdded;
+
+    // If there's a mismatch involving the effect's polarity or condition,
+    // issue a warning.
+    case Kind::DenyToAssert:
+    case Kind::AssertToDeny:
+    case Kind::ConditionMismatch:
+      return OverrideResult::Warn;
+    }
+
+  case FunctionEffect::Kind::None:
     break;
   }
   llvm_unreachable("unknown effect kind");
@@ -5172,7 +5209,7 @@ void FunctionEffectsRef::Profile(llvm::FoldingSetNodeID &ID) const {
 
   ID.AddInteger(size() | (HasConds << 31u));
   for (unsigned Idx = 0, Count = Effects.size(); Idx != Count; ++Idx) {
-    ID.AddInteger(llvm::to_underlying(Effects[Idx].kind()));
+    ID.AddInteger(Effects[Idx].toOpaqueInt32());
     if (HasConds)
       ID.AddPointer(Conditions[Idx].expr());
   }
@@ -5183,12 +5220,13 @@ void FunctionEffectSet::insert(FunctionEffect Effect, Expr *Cond) {
   unsigned Idx = 0;
   for (unsigned Count = Effects.size(); Idx != Count; ++Idx) {
     const auto &IterEffect = Effects[Idx];
-    if (IterEffect == Effect) {
-      // TODO: Is it okay to assume the caller has already diagnosed
-      // any potential conflict with conditions here?
+    if (IterEffect.kind() == Effect.kind()) {
+      // It's possible here to have incompatible combinations of polarity
+      // (asserted/denied) and condition; for now, we keep whichever came
+      // though this should be improved.
       return;
     }
-    if (Effect < IterEffect)
+    if (Effect.kind() < IterEffect.kind())
       break;
   }
 
@@ -5219,8 +5257,10 @@ void FunctionEffectSet::replaceCondition(unsigned Idx, Expr *Cond) {
 void FunctionEffectSet::erase(unsigned Idx) {
   assert(Idx < Effects.size());
   Effects.erase(Effects.begin() + Idx);
-  if (!Conditions.empty())
+  if (!Conditions.empty()) {
+    assert(Idx < Conditions.size());
     Conditions.erase(Conditions.begin() + Idx);
+  }
 }
 
 FunctionEffectSet FunctionEffectSet::getUnion(FunctionEffectsRef LHS,
@@ -5245,19 +5285,6 @@ FunctionEffectSet::differences(const FunctionEffectsRef &Old,
   FunctionEffectsRef::iterator PNew = New.begin();
   FunctionEffectsRef::iterator NewEnd = New.end();
 
-  auto compare = [](const FunctionEffectWithCondition &LHS,
-                    const FunctionEffectWithCondition &RHS) {
-    if (LHS.Effect < RHS.Effect)
-      return -1;
-    if (LHS.Effect > RHS.Effect)
-      return 1;
-    if (LHS.Cond.expr() < RHS.Cond.expr())
-      return -1;
-    if (RHS.Cond.expr() < LHS.Cond.expr())
-      return 1;
-    return 0;
-  };
-
   while (true) {
     int cmp = 0;
     if (POld == OldEnd) {
@@ -5266,52 +5293,53 @@ FunctionEffectSet::differences(const FunctionEffectsRef &Old,
       cmp = 1;
     } else if (PNew == NewEnd)
       cmp = -1;
-    else
-      cmp = compare(*POld, *PNew);
+    else {
+      FunctionEffectWithCondition Old = *POld;
+      FunctionEffectWithCondition New = *PNew;
+      if (Old.Effect.kind() < New.Effect.kind())
+        cmp = -1;
+      else if (New.Effect.kind() < Old.Effect.kind())
+        cmp = 1;
+      else {
+        cmp = 0;
+        if (Old.Cond.expr() != New.Cond.expr()) {
+          // TODO: Cases where the expressions are equivalent but
+          // don't have the same identity.
+          Result.push_back(FunctionEffectDiff{
+              Old.Effect.kind(), FunctionEffectDiff::Kind::ConditionMismatch,
+              Old, New});
+        } else if (!Old.Effect.isDenied() && New.Effect.isDenied()) {
+          Result.push_back(FunctionEffectDiff{
+              Old.Effect.kind(), FunctionEffectDiff::Kind::AssertToDeny, Old,
+              New});
+        } else if (Old.Effect.isDenied() && !New.Effect.isDenied()) {
+          Result.push_back(FunctionEffectDiff{
+              Old.Effect.kind(), FunctionEffectDiff::Kind::DenyToAssert, Old,
+              New});
+        }
+      }
+    }
 
     if (cmp < 0) {
       // removal
-      Result.push_back({*POld, false});
+      FunctionEffectWithCondition Old = *POld;
+      Result.push_back(FunctionEffectDiff{
+          Old.Effect.kind(), FunctionEffectDiff::Kind::Removed, Old, {}});
       ++POld;
     } else if (cmp > 0) {
       // addition
-      Result.push_back({*PNew, true});
+      FunctionEffectWithCondition New = *PNew;
+      Result.push_back(FunctionEffectDiff{
+          New.Effect.kind(), FunctionEffectDiff::Kind::Added, {}, New});
       ++PNew;
     } else {
       ++POld;
       ++PNew;
     }
   }
-
   return Result;
 }
 
-#if 0
-FunctionEffectSet
-FunctionEffectSet::difference(FunctionEffectsRef LHS,
-                                  FunctionEffectsRef RHS) {
-  FunctionEffectSet Result;
-  std::set_difference(LHS.begin(), LHS.end(), RHS.begin(), RHS.end(),
-                      std::back_inserter(Result.Impl));
-  return Result;
-}
-
-void FunctionEffectSet::insert(FunctionEffectsRef Arr) {
-  // TODO: For large RHS sets, use set_union or a custom insert-in-place
-  for (const auto &CFE : Arr) {
-    insert(CFE);
-  }
-}
-
-void FunctionEffectSet::insertIgnoringConditions(
-    FunctionEffectsRef Arr) {
-  // TODO: For large RHS sets, use set_union or a custom insert-in-place
-  for (const auto &CFE : Arr) {
-    insert(FunctionEffectWithCondition(CFE.effect().kind(), nullptr));
-  }
-}
-#endif
-
 LLVM_DUMP_METHOD void FunctionEffectsRef::dump(llvm::raw_ostream &OS) const {
   OS << "Effects{";
   bool First = true;
@@ -5321,7 +5349,7 @@ LLVM_DUMP_METHOD void FunctionEffectsRef::dump(llvm::raw_ostream &OS) const {
     else
       First = false;
     OS << CFE.Effect.name();
-    if (Expr * E = CFE.Cond.expr()) {
+    if (Expr *E = CFE.Cond.expr()) {
       OS << '(';
       E->dump();
       OS << ')';
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index f82b3eee055b60..7aa4acfd3bbd46 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2385,7 +2385,7 @@ class UnsafeBufferUsageReporter : public UnsafeBufferUsageHandler {
 // =============================================================================
 
 // Temporary feature enablement
-#define FX_ANALYZER_ENABLED 0
+#define FX_ANALYZER_ENABLED 1
 
 #if FX_ANALYZER_ENABLED
 
@@ -2453,37 +2453,14 @@ static bool functionIsVerifiable(const FunctionDecl *FD) {
   return true;
 }
 
-#if 0
 /// A mutable set of FunctionEffect, for use in places where any conditions
 /// have been resolved or can be ignored.
 class EffectSet {
-  SmallVector<FunctionEffect, 4> Impl;
-public:
-  EffectSet() = default;
-
-  operator ArrayRef<FunctionEffect>() const { return Impl; }
-
-  using iterator = const FunctionEffect *;
-  iterator begin() const { return Impl.begin(); }
-  iterator end() const { return Impl.end(); }
-
-  void insert(const FunctionEffect &Effect);
-  void insert(const EffectSet &Set);
-  void insertIgnoringConditions(ArrayRef<FunctionEffectWithCondition> Arr);
-
-  void dump(llvm::raw_ostream &OS) const;
-
-  static EffectSet difference(ArrayRef<FunctionEffect> LHS, ArrayRef<FunctionEffect> RHS);
-};
-#endif
-
-/// A mutable set of FunctionEffect, for use in places where any conditions
-/// have been resolved or can be ignored.
-// (This implementation optimizes footprint. As long as FunctionEffect is only 1
-// byte, and there are only 2 possible effects, this is more than sufficient. In
-// AnalysisBasedWarnings, we hold one of these for every function visited,
-// which, due to inference, can be many more functions than have effects.)
-class EffectSet {
+  // This implementation optimizes footprint. As long as FunctionEffect is only
+  // 1 byte, and there are only 2 possible effects, this is more than
+  // sufficient. In AnalysisBasedWarnings, we hold one of these for every
+  // function visited, which, due to inference, can be many more functions than
+  // have declared effects.
   template <typename T, typename SizeT, SizeT Capacity> struct FixedVector {
     SizeT Count = 0;
     T Items[Capacity] = {};
@@ -2592,9 +2569,10 @@ struct CondEffectSet {
 
   CondEffectSet(Sema &SemaRef, FunctionEffectsRef FX) {
     for (const auto Item : FX) {
-      if (Expr *Cond = Item.Cond) {
+      if (Expr *Cond = Item.Cond.expr()) {
         FunctionEffectMode Mode = FunctionEffectMode::None;
-        ExprResult ER = SemaRef.ActOnEffectExpression(Cond, Mode, /*RequireConstexpr=*/true);
+        ExprResult ER = SemaRef.ActOnEffectExpression(
+            Cond, Mode, /*RequireConstexpr=*/true);
         if (ER.isInvalid() || Mode == FunctionEffectMode::Dependent)
           continue;
         if (Mode == FunctionEffectMode::False) {
@@ -2618,7 +2596,8 @@ struct CallableInfo {
   CondEffectSet Effects;
   CallType CType = CallType::Unknown;
 
-  CallableInfo(Sema &SemaRef, const Decl &CD, SpecialFuncType FT = SpecialFuncType::None)
+  CallableInfo(Sema &SemaRef, const Decl &CD,
+               SpecialFuncType FT = SpecialFuncType::None)
       : CDecl(&CD), FuncType(FT) {
     // llvm::errs() << "CallableInfo " << name() << "\n";
     FunctionEffectsRef FXRef;
@@ -2783,16 +2762,16 @@ class PendingFunctionAnalysis {
     EffectSet FX;
 
     for (const auto &effect : AllInferrableEffectsToVerify) {
-      if (effect.canInferOnFunction(*CInfo.CDecl) && !CInfo.Effects.EffectsExplicitlyAbsent.contains(effect)) {
+      if (effect.canInferOnFunction(*CInfo.CDecl) &&
+          !CInfo.Effects.EffectsExplicitlyAbsent.contains(effect)) {
         FX.insert(effect);
       } else {
         // Add a diagnostic for this effect if a caller were to
         // try to infer it.
         auto &diag =
             InferrableEffectToFirstDiagnostic.getOrInsertDefault(effect);
-        diag =
-            Diagnostic(effect, DiagnosticID::DeclDisallowsInference,
-                       CInfo.CDecl->getLocation());
+        diag = Diagnostic(effect, DiagnosticID::DeclDisallowsInference,
+                          CInfo.CDecl->getLocation());
       }
     }
     // FX is now the set of inferrable effects which are not prohibited
@@ -2915,7 +2894,7 @@ const Decl *CanonicalFunctionDecl(const Decl *D) {
 
 // ==========
 class Analyzer {
-  constexpr static int DebugLogLevel = 3;
+  constexpr static int DebugLogLevel = 0;
   // --
   Sema &Sem;
 
@@ -3206,8 +3185,8 @@ class Analyzer {
             !(Flags & FunctionEffect::FE_InferrableOnCallees)) {
           if (Callee.FuncType == SpecialFuncType::None) {
             PFA.checkAddDiagnostic(
-                Inferring,
-                {Effect, DiagnosticID::CallsDeclWithoutEffect, CallLoc, Callee.CDecl});
+                Inferring, {Effect, DiagnosticID::CallsDeclWithoutEffect,
+                            CallLoc, Callee.CDecl});
           } else {
             PFA.checkAddDiagnostic(
                 Inferring, {Effect, DiagnosticID::AllocatesMemory, CallLoc});
@@ -3254,7 +3233,7 @@ class Analyzer {
       switch (Diag.ID) {
       case DiagnosticID::None:
       case DiagnosticID::DeclDisallowsInference: // shouldn't happen
-                                                           // here
+                                                 // here
         llvm_unreachable("Unexpected diagnostic kind");
         break;
       case DiagnosticID::AllocatesMemory:
@@ -3311,9 +3290,11 @@ class Analyzer {
               S.Diag(Callee->getLocation(),
                      diag::note_func_effect_call_func_ptr)
                   << effectName;
-            } else if (CalleeInfo.Effects.EffectsExplicitlyAbsent.contains(Diag.Effect)) {
-              S.Diag(Callee->getLocation(), diag::note_func_effect_call_disallows_inference)
-                << effectName;
+            } else if (CalleeInfo.Effects.EffectsExplicitlyAbsent.contains(
+                           Diag.Effect)) {
+              S.Diag(Callee->getLocation(),
+                     diag::note_func_effect_call_disallows_inference)
+                  << effectName;
             } else {
               S.Diag(Callee->getLocation(), diag::note_func_effect_call_extern)
                   << effectName;
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index 4ac0208512f188..67042492341a2a 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -593,15 +593,9 @@ void Sema::diagnoseFunctionEffectConversion(QualType DstType, QualType SrcType,
   const auto SrcFX = FunctionEffectsRef::get(SrcType);
   const auto DstFX = FunctionEffectsRef::get(DstType);
   if (SrcFX != DstFX) {
-    for (const auto &Item : FunctionEffectSet::differences(SrcFX, DstFX)) {
-      const FunctionEffect &Effect = Item.first.Effect;
-      const bool Adding = Item.second;
-      if (Effect.shouldDiagnoseConversion(Adding, SrcType, SrcFX, DstType,
-                                          DstFX)) {
-        Diag(Loc, Adding ? diag::warn_invalid_add_func_effects
-                         : diag::warn_invalid_remove_func_effects)
-            << Effect.name();
-      }
+    for (const auto &Diff : FunctionEffectSet::differences(SrcFX, DstFX)) {
+      if (Diff.shouldDiagnoseConversion(SrcType, SrcFX, DstType, DstFX))
+        Diag(Loc, diag::warn_invalid_add_func_effects) << Diff.effectName();
     }
   }
 }
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 60c7fe74729503..8824bdc307632f 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3925,14 +3925,11 @@ bool Sema::MergeFunctionDecl(FunctionDecl *New, NamedDecl *&OldD, Scope *S,
   QualType OldQTypeForComparison = OldQType;
   if (OldFX != NewFX) {
     const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
-    for (const auto &Item : Diffs) {
-      const FunctionEffect &Effect = Item.first.Effect;
-      const bool Adding = Item.second;
-      if (Effect.shouldDiagnoseRedeclaration(Adding, *Old, OldFX, *New,
-                                             NewFX)) {
+    for (const auto &Diff : Diffs) {
+      if (Diff.shouldDiagnoseRedeclaration(*Old, OldFX, *New, NewFX)) {
         Diag(New->getLocation(),
              diag::warn_mismatched_func_effect_redeclaration)
-            << Effect.name();
+            << Diff.effectName();
         Diag(Old->getLocation(), diag::note_previous_declaration);
       }
     }
@@ -11153,6 +11150,10 @@ void Sema::maybeAddDeclWithEffects(const Decl *D,
     return;
   }
 
+  addDeclWithEffects(D, FX);
+}
+
+void Sema::addDeclWithEffects(const Decl *D, const FunctionEffectsRef &FX) {
   // Ignore any conditions when building the list of effects.
   AllEffectsToVerify.insertIgnoringConditions(FX);
 
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 1e89f97bc5f204..f593251b0fd530 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18295,7 +18295,7 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
 
   if (OldFT->hasExtParameterInfos()) {
     for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I)
-      // A parameter of the overriding method should be annotated with noescape
+      // A parameter of the overriding method should  be annotated with noescape
       // if the corresponding parameter of the overridden method is annotated.
       if (OldFT->getExtParameterInfo(I).isNoEscape() &&
           !NewFT->getExtParameterInfo(I).isNoEscape()) {
@@ -18326,39 +18326,33 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
 
   // Virtual overrides: check for matching effects.
   const auto OldFX = Old->getFunctionEffects();
-  const auto NewFX = New->getFunctionEffects();
+  const auto NewFXOrig = New->getFunctionEffects();
 
-  if (OldFX != NewFX) {
+  if (OldFX != NewFXOrig) {
+    FunctionEffectSet NewFX(NewFXOrig);
     const auto Diffs = FunctionEffectSet::differences(OldFX, NewFX);
-    bool AnyDiags = false;
-
-    for (const auto &Item : Diffs) {
-      const FunctionEffect &Effect = Item.first.Effect;
-      const bool Adding = Item.second;
-      switch (Effect.shouldDiagnoseMethodOverride(Adding, *Old, OldFX, *New,
-                                                  NewFX)) {
-      case FunctionEffect::OverrideResult::Ignore:
+    for (const auto &Diff : Diffs) {
+      switch (Diff.shouldDiagnoseMethodOverride(*Old, OldFX, *New, NewFX)) {
+      case FunctionEffectDiff::OverrideResult::NoAction:
         break;
-      case FunctionEffect::OverrideResult::Warn:
+      case FunctionEffectDiff::OverrideResult::Warn:
         Diag(New->getLocation(), diag::warn_mismatched_func_effect_override)
-            << Effect.name();
-        Diag(Old->getLocation(), diag::note_overridden_virtual_function);
-        // TODO: It would be nice to have a FIXIT here!
-        AnyDiags = true;
+            << Diff.effectName();
+        Diag(Old->getLocation(), diag::note_overridden_virtual_function)
+            << Old->getReturnTypeSourceRange();
         break;
-      case FunctionEffect::OverrideResult::Merge: {
-        auto MergedFX = FunctionEffectSet::getUnion(OldFX, NewFX);
-
+      case FunctionEffectDiff::OverrideResult::MergeAdded: {
+        NewFX.insert(Diff.New.Effect, Diff.New.Cond.expr());
+        const auto *NewFT = New->getType()->castAs<FunctionProtoType>();
         FunctionProtoType::ExtProtoInfo EPI = NewFT->getExtProtoInfo();
-        EPI.FunctionEffects = FunctionEffectsRef(MergedFX);
+        EPI.FunctionEffects = FunctionEffectsRef(NewFX);
         QualType ModQT = Context.getFunctionType(NewFT->getReturnType(),
                                                  NewFT->getParamTypes(), EPI);
         New->setType(ModQT);
-      } break;
+        break;
+      }
       }
     }
-    if (AnyDiags)
-      return true;
   }
 
   CallingConv NewCC = NewFT->getCallConv(), OldCC = OldFT->getCallConv();
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index b7cbb2524d7484..b27d85a858d892 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -218,8 +218,8 @@ namespace {
     // nonallocating(cond). Manual logic for finding previous attributes would
     // be more complex, unless we transformed nonblocking/nonallocating(false)
     // into distinct separate attributes from the ones which are parsed.
-    FunctionEffectMode parsedNonBlocking : 2;
-    FunctionEffectMode parsedNonAllocating : 2;
+    FunctionEffectMode parsedNonBlocking;
+    FunctionEffectMode parsedNonAllocating;
 
   public:
     TypeProcessingState(Sema &sema, Declarator &declarator)
@@ -354,9 +354,15 @@ namespace {
     bool didParseNoDeref() const { return parsedNoDeref; }
 
     void setParsedNonBlocking(FunctionEffectMode v) { parsedNonBlocking = v; }
-    FunctionEffectMode getParsedNonBlocking() const { return parsedNonBlocking; }
-    void setParsedNonAllocating(FunctionEffectMode v) { parsedNonAllocating = v; }
-    FunctionEffectMode getParsedNonAllocating() const { return parsedNonAllocating; }
+    FunctionEffectMode getParsedNonBlocking() const {
+      return parsedNonBlocking;
+    }
+    void setParsedNonAllocating(FunctionEffectMode v) {
+      parsedNonAllocating = v;
+    }
+    FunctionEffectMode getParsedNonAllocating() const {
+      return parsedNonAllocating;
+    }
 
     ~TypeProcessingState() {
       if (savedAttrs.empty())
@@ -7977,8 +7983,8 @@ static Attr *getCCTypeAttr(ASTContext &Ctx, ParsedAttr &Attr) {
   llvm_unreachable("unexpected attribute kind!");
 }
 
-ExprResult Sema::ActOnEffectExpression(Expr *CondExpr, FunctionEffectMode &Mode, bool RequireConstexpr)
-{
+ExprResult Sema::ActOnEffectExpression(Expr *CondExpr, FunctionEffectMode &Mode,
+                                       bool RequireConstexpr) {
   // see checkFunctionConditionAttr, Sema::CheckCXXBooleanCondition
   if (RequireConstexpr || !CondExpr->isTypeDependent()) {
     ExprResult E = PerformContextuallyConvertToBool(CondExpr);
@@ -8071,8 +8077,8 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
   };
 
   const FunctionEffectMode PrevState = isNonBlocking
-                                      ? TPState.getParsedNonBlocking()
-                                      : TPState.getParsedNonAllocating();
+                                           ? TPState.getParsedNonBlocking()
+                                           : TPState.getParsedNonAllocating();
   if (PrevState != FunctionEffectMode::None) {
     // Only one attribute per constraint is allowed.
     return incompatible(isNonBlocking, PrevState);
@@ -8112,11 +8118,13 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
   // FunctionEffectsRef attached to a FunctionProtoType.
   const FunctionEffect NewEffect(isNonBlocking
                                      ? FunctionEffect::Kind::NonBlocking
-                                     : FunctionEffect::Kind::NonAllocating);
+                                     : FunctionEffect::Kind::NonAllocating,
+                                 /*IsDenied=*/false);
 
   FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
   FunctionEffectSet FX(EPI.FunctionEffects);
-  FX.insert(NewEffect, NewState == FunctionEffectMode::Dependent ? CondExpr : nullptr);
+  FX.insert(NewEffect,
+            NewState == FunctionEffectMode::Dependent ? CondExpr : nullptr);
   EPI.FunctionEffects = FunctionEffectsRef(FX);
 
   QualType newtype = S.Context.getFunctionType(FPT->getReturnType(),
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index c8816d6651e6df..13fe13d0fafae4 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -6239,7 +6239,7 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
   // Transform any function effects with unevaluated conditions.
   // Hold this set in a local for the rest of this function, since EPI
   // is going to hold a FunctionEffectsRef pointing into it.
-  std::optional <FunctionEffectSet> NewFX;
+  std::optional<FunctionEffectSet> NewFX;
 #if XFORM_FALSE_FX_TO_SUGAR
   SmallVector<Attr *> TypeAttrsToAdd;
 #endif
@@ -6248,7 +6248,7 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
     EnterExpressionEvaluationContext Unevaluated(
         getSema(), Sema::ExpressionEvaluationContext::ConstantEvaluated);
 
-    for (unsigned Idx = 0, Count = FXConds.size(); Idx != Count; ) {
+    for (unsigned Idx = 0, Count = FXConds.size(); Idx != Count;) {
       if (Expr *CondExpr = FXConds[Idx].expr()) {
         ExprResult NewExpr = getDerived().TransformExpr(CondExpr);
         if (NewExpr.isInvalid())
@@ -6277,7 +6277,8 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
         // If it is now a constant of 'true', we can discard it because a null
         // condition in FunctionEffectSet means true. If the expression is still
         //  dependent or constant 'false', just propagate it into the new EPI.
-        FunctionEffectCondition Cond(Mode == FunctionEffectMode::True ? nullptr : NewExpr.get());
+        FunctionEffectCondition Cond(
+            Mode == FunctionEffectMode::True ? nullptr : NewExpr.get());
         NewFX->replaceCondition(Idx, Cond.expr());
 #endif
       }
@@ -6309,7 +6310,8 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
   // be transformed to FunctionProtoType.
   if (!TypeAttrsToAdd.empty()) {
     for (Attr *A : TypeAttrsToAdd) {
-      QualType QT = SemaRef.Context.getAttributedType(A->getKind(), Result, Result);
+      QualType QT =
+          SemaRef.Context.getAttributedType(A->getKind(), Result, Result);
       llvm::outs() << "transformed " << Result << " -> " << QT;
       Result = QT;
       AttributedTypeLoc ATL = TLB.push<AttributedTypeLoc>(Result);
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index dede16d84dc1b3..94b7338bd7aa19 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -8233,7 +8233,7 @@ void ASTReader::InitializeSema(Sema &S) {
         FX = BD->getFunctionEffects();
       }
       if (!FX.empty()) {
-        SemaObj->AllEffectsToVerify.insertIgnoringConditions(FX);
+        SemaObj->addDeclWithEffects(D, FX);
       }
     }
     DeclsWithEffectsToVerify.clear();

>From ca9b8faebae8c60e60179a662c1f0160eeb4c4cb Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 24 Apr 2024 10:45:42 -0700
Subject: [PATCH 38/40] - Adapt to merge from main. - represent
 blocking/allocating separately rather than "denied" variants - SemaType: use
 canonical representation for "denied" - TreeTransform: adapt to canonical
 representation of "denied"

---
 clang/include/clang/AST/Type.h                | 47 ++++-----
 clang/include/clang/Basic/AttrDocs.td         |  3 +-
 clang/include/clang/Sema/Sema.h               |  6 +-
 clang/include/clang/Serialization/ASTReader.h |  2 +-
 clang/lib/AST/Type.cpp                        | 95 ++++++++++++++-----
 clang/lib/Sema/SemaDecl.cpp                   |  7 +-
 clang/lib/Sema/SemaDeclCXX.cpp                |  4 +-
 clang/lib/Sema/SemaType.cpp                   | 13 ++-
 clang/lib/Sema/TreeTransform.h                | 61 ++++--------
 clang/lib/Serialization/ASTReader.cpp         | 15 ++-
 10 files changed, 138 insertions(+), 115 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 3003d504bdb31b..c08e08913750f7 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4443,8 +4443,7 @@ class FunctionEffectsRef;
 class FunctionEffectSet;
 
 /// Represents an abstract function effect, using just an enumeration describing
-/// its kind and a bool "denied", which indicates that the effect is asserted
-/// NOT to apply (preventing inference of the effect).
+/// its kind.
 class FunctionEffect {
 public:
   /// Identifies the particular effect.
@@ -4452,13 +4451,16 @@ class FunctionEffect {
     None = 0,
     NonBlocking = 1,
     NonAllocating = 2,
+    Blocking = 3,
+    Allocating = 4
   };
 
   /// Flags describing some behaviors of the effect.
   using Flags = unsigned;
   enum FlagBit : Flags {
     // Can verification inspect callees' implementations? (e.g. nonblocking:
-    // yes, tcb+types: no)
+    // yes, tcb+types: no). This also implies the need for 2nd-pass
+    // verification.
     FE_InferrableOnCallees = 0x1,
 
     // Language constructs which effects can diagnose as disallowed.
@@ -4471,31 +4473,27 @@ class FunctionEffect {
 
 private:
   LLVM_PREFERRED_TYPE(Kind)
-  unsigned FKind : 2;
-
-  LLVM_PREFERRED_TYPE(bool)
-  unsigned IsDenied : 1;
+  unsigned FKind : 3;
 
   // Expansion: for hypothetical TCB+types, there could be one Kind for TCB,
   // then ~16(?) bits "SubKind" to map to a specific named TCB. SubKind would
   // be considered for uniqueness.
 
 public:
-  FunctionEffect() : FKind(unsigned(Kind::None)), IsDenied(false) {}
+  FunctionEffect() : FKind(unsigned(Kind::None)) {}
 
-  FunctionEffect(Kind K, bool IsDenied)
-      : FKind(unsigned(K)), IsDenied(IsDenied) {}
+  FunctionEffect(Kind K) : FKind(unsigned(K)) {}
 
   /// The kind of the effect.
   Kind kind() const { return Kind(FKind); }
 
-  /// Whether the effect is being denied (as opposed to asserted).
-  bool isDenied() const { return IsDenied; }
+  /// Return the opposite kind, for effects which have opposites.
+  Kind oppositeKind() const;
 
   /// For serialization.
-  uint32_t toOpaqueInt32() const { return (FKind << 1) | IsDenied; }
+  uint32_t toOpaqueInt32() const { return FKind; }
   static FunctionEffect fromOpaqueInt32(uint32_t Value) {
-    return FunctionEffect(Kind(Value >> 1), Value & 1);
+    return FunctionEffect(Kind(Value));
   }
 
   /// Flags describing some behaviors of the effect.
@@ -4509,6 +4507,9 @@ class FunctionEffect {
       // Same as NonBlocking, except without FE_ExcludeStaticLocalVars
       return FE_InferrableOnCallees | FE_ExcludeThrow | FE_ExcludeCatch |
              FE_ExcludeObjCMessageSend | FE_ExcludeThreadLocalVars;
+    case Kind::Blocking:
+    case Kind::Allocating:
+      return 0;
     case Kind::None:
       break;
     }
@@ -4533,7 +4534,7 @@ class FunctionEffect {
                                   ArrayRef<FunctionEffect> CalleeFX) const;
 
   friend bool operator==(const FunctionEffect &LHS, const FunctionEffect &RHS) {
-    return LHS.FKind == RHS.FKind && LHS.IsDenied == RHS.IsDenied;
+    return LHS.FKind == RHS.FKind;
   }
   friend bool operator!=(const FunctionEffect &LHS, const FunctionEffect &RHS) {
     return !(LHS == RHS);
@@ -4568,13 +4569,7 @@ struct FunctionEffectWithCondition {
 };
 
 struct FunctionEffectDiff {
-  enum class Kind {
-    Added,
-    Removed,
-    AssertToDeny,
-    DenyToAssert,
-    ConditionMismatch
-  };
+  enum class Kind { Added, Removed, ConditionMismatch };
 
   FunctionEffect::Kind EffectKind;
   Kind DiffKind;
@@ -4592,7 +4587,7 @@ struct FunctionEffectDiff {
   enum class OverrideResult {
     NoAction,
     Warn,
-    MergeAdded // Merge an added effect
+    Merge // Merge missing effect from base to derived
   };
 
   /// Return true if adding or removing the effect as part of a type conversion
@@ -4697,9 +4692,7 @@ class FunctionEffectsRef {
 /// A mutable set of FunctionEffects and possibly conditions attached to them.
 /// Used transitorily within Sema to compare and merge effects on declarations.
 ///
-/// Invariant: there is never more than one instance of any given effect. This
-/// is asserted in insert and getUnion; it is the caller's responsibility to
-/// diagnose this.
+/// Invariant: there is never more than one instance of any given effect.
 class FunctionEffectSet {
   SmallVector<FunctionEffect> Effects;
   // The vector of conditions is either empty or has the same size
@@ -4730,7 +4723,7 @@ class FunctionEffectSet {
   void insert(const FunctionEffectsRef &Set);
   void insertIgnoringConditions(const FunctionEffectsRef &Set);
 
-  void replaceCondition(unsigned Idx, Expr *Cond);
+  void replaceItem(unsigned Idx, const FunctionEffectWithCondition &Item);
   void erase(unsigned Idx);
 
   // Set operations
diff --git a/clang/include/clang/Basic/AttrDocs.td b/clang/include/clang/Basic/AttrDocs.td
index 9a3dc0ea67b9c1..0b4ed5a1dc6262 100644
--- a/clang/include/clang/Basic/AttrDocs.td
+++ b/clang/include/clang/Basic/AttrDocs.td
@@ -1,5 +1,4 @@
-  
-  //==--- AttrDocs.td - Attribute documentation ----------------------------===//
+//==--- AttrDocs.td - Attribute documentation ----------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 083129b66f3554..b5ce248be57c5c 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -776,9 +776,7 @@ class Sema final : public SemaBase {
   /// Warn when implicitly casting 0 to nullptr.
   void diagnoseZeroToNullptrConversion(CastKind Kind, const Expr *E);
 
-  // ----- function effects --- where ?????
-  // Ultimately some more of the effects implementation could/should be moved
-  // out of Type.h, but where to?
+  // ----- function effects ---
 
   /// All functions/lambdas/blocks which have bodies and which have a non-empty
   /// FunctionEffectsRef to be verified.
@@ -803,8 +801,6 @@ class Sema final : public SemaBase {
   ExprResult ActOnEffectExpression(Expr *CondExpr, FunctionEffectMode &Mode,
                                    bool RequireConstexpr = false);
 
-  // ----- function effects --- where ?????
-
   bool makeUnavailableInSystemHeader(SourceLocation loc,
                                      UnavailableAttr::ImplicitReason reason);
 
diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
index 683f64532586da..4ac7dd76febd6a 100644
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -978,7 +978,7 @@ class ASTReader
       DeclsToCheckForDeferredDiags;
 
   /// The IDs of all decls with function effects to be checked.
-  SmallVector<serialization::DeclID> DeclsWithEffectsToVerify;
+  SmallVector<serialization::GlobalDeclID, 0> DeclsWithEffectsToVerify;
 
 private:
   struct ImportedSubmodule {
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 3702163336baf0..750da4f6bdc7a8 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5042,12 +5042,32 @@ void AutoType::Profile(llvm::FoldingSetNodeID &ID, const ASTContext &Context) {
           getTypeConstraintConcept(), getTypeConstraintArguments());
 }
 
+FunctionEffect::Kind FunctionEffect::oppositeKind() const {
+  switch (kind()) {
+  case Kind::NonBlocking:
+    return Kind::Blocking;
+  case Kind::Blocking:
+    return Kind::NonBlocking;
+  case Kind::NonAllocating:
+    return Kind::Allocating;
+  case Kind::Allocating:
+    return Kind::NonAllocating;
+  case Kind::None:
+    break;
+  }
+  llvm_unreachable("unknown effect kind");
+}
+
 StringRef FunctionEffect::name() const {
   switch (kind()) {
   case Kind::NonBlocking:
     return "nonblocking";
   case Kind::NonAllocating:
     return "nonallocating";
+  case Kind::Blocking:
+    return "blocking";
+  case Kind::Allocating:
+    return "allocating";
   case Kind::None:
     break;
   }
@@ -5076,15 +5096,12 @@ bool FunctionEffectDiff::shouldDiagnoseConversion(
       return true;
     case Kind::Removed:
       return false;
-    case Kind::AssertToDeny:
-      // effect asserted -> denied: no diagnostic.
-      return false;
-    case Kind::DenyToAssert:
-      // effect denied -> asserted: diagnose.
-      return true;
     case Kind::ConditionMismatch:
       return true; // TODO: ???
     }
+  case FunctionEffect::Kind::Blocking:
+  case FunctionEffect::Kind::Allocating:
+    return false;
   case FunctionEffect::Kind::None:
     break;
   }
@@ -5103,12 +5120,13 @@ bool FunctionEffectDiff::shouldDiagnoseRedeclaration(
       return false; // No diagnostic.
     case Kind::Removed:
       return true; // Issue diagnostic
-    case Kind::DenyToAssert:
-    case Kind::AssertToDeny:
     case Kind::ConditionMismatch:
       // All these forms of mismatches are diagnosed.
       return true;
     }
+  case FunctionEffect::Kind::Blocking:
+  case FunctionEffect::Kind::Allocating:
+    return false;
   case FunctionEffect::Kind::None:
     break;
   }
@@ -5130,16 +5148,18 @@ FunctionEffectDiff::shouldDiagnoseMethodOverride(
 
     // If missing from an override (removed), propagate from base to derived.
     case Kind::Removed:
-      return OverrideResult::MergeAdded;
+      return OverrideResult::Merge;
 
     // If there's a mismatch involving the effect's polarity or condition,
     // issue a warning.
-    case Kind::DenyToAssert:
-    case Kind::AssertToDeny:
     case Kind::ConditionMismatch:
       return OverrideResult::Warn;
     }
 
+  case FunctionEffect::Kind::Blocking:
+  case FunctionEffect::Kind::Allocating:
+    return OverrideResult::NoAction;
+
   case FunctionEffect::Kind::None:
     break;
   }
@@ -5149,7 +5169,28 @@ FunctionEffectDiff::shouldDiagnoseMethodOverride(
 bool FunctionEffect::canInferOnFunction(const Decl &Callee) const {
   switch (kind()) {
   case Kind::NonAllocating:
-  case Kind::NonBlocking:
+  case Kind::NonBlocking: {
+    FunctionEffectsRef CalleeFX;
+    if (auto *FD = Callee.getAsFunction())
+      CalleeFX = FD->getFunctionEffects();
+    else if (auto *BD = dyn_cast<BlockDecl>(&Callee))
+      CalleeFX = BD->getFunctionEffects();
+    else
+      return false;
+    for (const FunctionEffectWithCondition &CalleeEC : CalleeFX) {
+      // nonblocking/nonallocating cannot call allocating
+      if (CalleeEC.Effect.kind() == Kind::Allocating)
+        return false;
+      // nonblocking cannot call blocking
+      if (kind() == Kind::NonBlocking &&
+          CalleeEC.Effect.kind() == Kind::Blocking)
+        return false;
+    }
+  }
+    return true;
+
+#if 0
+    // This is the type-sugar implementation of "denied" effects.
     // Do any of the callee's Decls have type sugar for blocking or allocating?
     for (const Decl *D : Callee.redecls()) {
       QualType QT;
@@ -5174,6 +5215,11 @@ bool FunctionEffect::canInferOnFunction(const Decl &Callee) const {
       }
     }
     return true;
+#endif
+  case Kind::Allocating:
+  case Kind::Blocking:
+    return false;
+
   case Kind::None:
     break;
   }
@@ -5196,6 +5242,9 @@ bool FunctionEffect::shouldDiagnoseFunctionCall(
     }
     return true; // warning
   }
+  case Kind::Allocating:
+  case Kind::Blocking:
+    return false;
   case Kind::None:
     break;
   }
@@ -5249,9 +5298,19 @@ void FunctionEffectSet::insertIgnoringConditions(
     insert(Item.Effect, nullptr);
 }
 
-void FunctionEffectSet::replaceCondition(unsigned Idx, Expr *Cond) {
+void FunctionEffectSet::replaceItem(unsigned Idx,
+                                    const FunctionEffectWithCondition &Item) {
   assert(Idx < Conditions.size());
-  Conditions[Idx] = FunctionEffectCondition(Cond);
+  Effects[Idx] = Item.Effect;
+  Conditions[Idx] = Item.Cond;
+
+  // Maintain invariant: If all conditions are null, the vector should be empty.
+  if (std::all_of(Conditions.begin(), Conditions.end(),
+                  [](const FunctionEffectCondition &C) {
+                    return C.expr() == nullptr;
+                  })) {
+    Conditions.clear();
+  }
 }
 
 void FunctionEffectSet::erase(unsigned Idx) {
@@ -5308,14 +5367,6 @@ FunctionEffectSet::differences(const FunctionEffectsRef &Old,
           Result.push_back(FunctionEffectDiff{
               Old.Effect.kind(), FunctionEffectDiff::Kind::ConditionMismatch,
               Old, New});
-        } else if (!Old.Effect.isDenied() && New.Effect.isDenied()) {
-          Result.push_back(FunctionEffectDiff{
-              Old.Effect.kind(), FunctionEffectDiff::Kind::AssertToDeny, Old,
-              New});
-        } else if (Old.Effect.isDenied() && !New.Effect.isDenied()) {
-          Result.push_back(FunctionEffectDiff{
-              Old.Effect.kind(), FunctionEffectDiff::Kind::DenyToAssert, Old,
-              New});
         }
       }
     }
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index e924546c30d388..cb93d5a9c0b9fc 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11174,7 +11174,12 @@ void Sema::maybeAddDeclWithEffects(const Decl *D,
     return;
   }
 
-  addDeclWithEffects(D, FX);
+  if (std::any_of(FX.begin(), FX.end(),
+                  [](const FunctionEffectWithCondition &EC) {
+                    return (EC.Effect.flags() &
+                            FunctionEffect::FE_InferrableOnCallees) != 0;
+                  }))
+    addDeclWithEffects(D, FX);
 }
 
 void Sema::addDeclWithEffects(const Decl *D, const FunctionEffectsRef &FX) {
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 6b457521b8ec29..cb3ec0abb8badf 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18392,8 +18392,8 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
         Diag(Old->getLocation(), diag::note_overridden_virtual_function)
             << Old->getReturnTypeSourceRange();
         break;
-      case FunctionEffectDiff::OverrideResult::MergeAdded: {
-        NewFX.insert(Diff.New.Effect, Diff.New.Cond.expr());
+      case FunctionEffectDiff::OverrideResult::Merge: {
+        NewFX.insert(Diff.Old.Effect, Diff.Old.Cond.expr());
         const auto *NewFT = New->getType()->castAs<FunctionProtoType>();
         FunctionProtoType::ExtProtoInfo EPI = NewFT->getExtProtoInfo();
         EPI.FunctionEffects = FunctionEffectsRef(NewFX);
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index c7f693fde1e3b6..c960935378156a 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8105,6 +8105,8 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
     TPState.setParsedNonAllocating(NewState);
   }
 
+#if 0
+  // Old type-sugar implementation of denied effects
   if (NewState == FunctionEffectMode::False) {
     // blocking and allocating are represented as AttributedType sugar,
     // using those attributes.
@@ -8117,13 +8119,16 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
     QT = TPState.getAttributedType(A, QT, QT);
     return true;
   }
+#endif
 
   // nonblocking/nonallocating(true/expr) are represented in a
   // FunctionEffectsRef attached to a FunctionProtoType.
-  const FunctionEffect NewEffect(isNonBlocking
-                                     ? FunctionEffect::Kind::NonBlocking
-                                     : FunctionEffect::Kind::NonAllocating,
-                                 /*IsDenied=*/false);
+  const bool Denied = NewState == FunctionEffectMode::False;
+  const FunctionEffect NewEffect(
+      isNonBlocking ? (Denied ? FunctionEffect::Kind::Blocking
+                              : FunctionEffect::Kind::NonBlocking)
+                    : (Denied ? FunctionEffect::Kind::Allocating
+                              : FunctionEffect::Kind::NonAllocating));
 
   FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
   FunctionEffectSet FX(EPI.FunctionEffects);
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index 2e2d398525299b..b602975f6c0338 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -6255,15 +6255,10 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
     EPI.ExtParameterInfos = nullptr;
   }
 
-#define XFORM_FALSE_FX_TO_SUGAR 0
-
   // Transform any function effects with unevaluated conditions.
   // Hold this set in a local for the rest of this function, since EPI
   // is going to hold a FunctionEffectsRef pointing into it.
   std::optional<FunctionEffectSet> NewFX;
-#if XFORM_FALSE_FX_TO_SUGAR
-  SmallVector<Attr *> TypeAttrsToAdd;
-#endif
   if (ArrayRef FXConds = EPI.FunctionEffects.conditions(); !FXConds.empty()) {
     NewFX.emplace(EPI.FunctionEffects);
     EnterExpressionEvaluationContext Unevaluated(
@@ -6279,29 +6274,26 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
         if (NewExpr.isInvalid())
           return QualType();
 
-#if XFORM_FALSE_FX_TO_SUGAR
-        if (Mode == FunctionEffectMode::False) {
-          NewFX->erase(Idx);
-          --Count;
-          const FunctionEffect Effect(EPI.FunctionEffects.effects()[Idx]);
-          if (Effect.kind() == FunctionEffect::Kind::NonAllocating) {
-            TypeAttrsToAdd.push_back(AllocatingAttr::Create(SemaRef.Context));
-          } else if (Effect.kind() == FunctionEffect::Kind::NonBlocking) {
-            TypeAttrsToAdd.push_back(BlockingAttr::Create(SemaRef.Context));
-          }
-          continue;
-        }
-        assert(Mode == FunctionEffectMode::True);
-        NewFX->replaceCondition(Idx, NewExpr.get());
-#else
         // The condition expression has been transformed, and re-evaluated.
-        // If it is now a constant of 'true', we can discard it because a null
-        // condition in FunctionEffectSet means true. If the expression is still
-        //  dependent or constant 'false', just propagate it into the new EPI.
-        FunctionEffectCondition Cond(
-            Mode == FunctionEffectMode::True ? nullptr : NewExpr.get());
-        NewFX->replaceCondition(Idx, Cond.expr());
-#endif
+        // It may or may not have become constant.
+        const FunctionEffect Effect(EPI.FunctionEffects.effects()[Idx]);
+        FunctionEffectWithCondition EC;
+        switch (Mode) {
+        case FunctionEffectMode::True:
+          EC.Effect = Effect;
+          break;
+        case FunctionEffectMode::False:
+          EC.Effect = FunctionEffect(Effect.oppositeKind());
+          break;
+        case FunctionEffectMode::Dependent:
+          EC.Effect = Effect;
+          EC.Cond = FunctionEffectCondition(NewExpr.get());
+          break;
+        case FunctionEffectMode::None:
+          llvm_unreachable(
+              "FunctionEffectMode::None shouldn't be possible here");
+        }
+        NewFX->replaceItem(Idx, EC);
       }
       ++Idx;
     }
@@ -6326,21 +6318,6 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
   for (unsigned i = 0, e = NewTL.getNumParams(); i != e; ++i)
     NewTL.setParam(i, ParamDecls[i]);
 
-#if XFORM_FALSE_FX_TO_SUGAR
-  // This creates problems because the caller assumes FunctionProtoType will
-  // be transformed to FunctionProtoType.
-  if (!TypeAttrsToAdd.empty()) {
-    for (Attr *A : TypeAttrsToAdd) {
-      QualType QT =
-          SemaRef.Context.getAttributedType(A->getKind(), Result, Result);
-      llvm::outs() << "transformed " << Result << " -> " << QT;
-      Result = QT;
-      AttributedTypeLoc ATL = TLB.push<AttributedTypeLoc>(Result);
-      ATL.setAttr(A);
-    }
-  }
-#endif
-
   return Result;
 }
 
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index e83795d814b8a3..907282eab56114 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3855,7 +3855,8 @@ llvm::Error ASTReader::ReadASTBlock(ModuleFile &F,
 
     case DECLS_WITH_EFFECTS_TO_VERIFY:
       for (unsigned I = 0, N = Record.size(); I != N; ++I)
-        DeclsWithEffectsToVerify.push_back(getGlobalDeclID(F, Record[I]));
+        DeclsWithEffectsToVerify.push_back(
+            getGlobalDeclID(F, LocalDeclID(Record[I])));
       break;
 
     case OPENCL_EXTENSIONS:
@@ -8238,19 +8239,15 @@ void ASTReader::InitializeSema(Sema &S) {
   }
 
   if (!DeclsWithEffectsToVerify.empty()) {
-    for (uint64_t ID : DeclsWithEffectsToVerify) {
+    for (GlobalDeclID ID : DeclsWithEffectsToVerify) {
       Decl *D = GetDecl(ID);
-      SemaObj->DeclsWithEffectsToVerify.push_back(D);
-
       FunctionEffectsRef FX;
-      if (auto *FD = dyn_cast<FunctionDecl>(D)) {
+      if (auto *FD = dyn_cast<FunctionDecl>(D))
         FX = FD->getFunctionEffects();
-      } else if (auto *BD = dyn_cast<BlockDecl>(D)) {
+      else if (auto *BD = dyn_cast<BlockDecl>(D))
         FX = BD->getFunctionEffects();
-      }
-      if (!FX.empty()) {
+      if (!FX.empty())
         SemaObj->addDeclWithEffects(D, FX);
-      }
     }
     DeclsWithEffectsToVerify.clear();
   }

>From 5143877e985815c80323ab2324ba7700f18183e4 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Wed, 24 Apr 2024 15:23:30 -0700
Subject: [PATCH 39/40] tiny cleanup

---
 clang/lib/AST/TypePrinter.cpp  | 8 ++------
 clang/lib/Sema/SemaDeclCXX.cpp | 2 +-
 clang/lib/Sema/SemaType.cpp    | 2 +-
 clang/lib/Sema/TreeTransform.h | 2 +-
 4 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 70fbb970935367..a7a10cbb7489cd 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -1944,6 +1944,8 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   case attr::ArmPreserves:
   case attr::NonBlocking:
   case attr::NonAllocating:
+  case attr::Blocking:
+  case attr::Allocating:
     llvm_unreachable("This attribute should have been handled already");
 
   case attr::NSReturnsRetained:
@@ -2003,12 +2005,6 @@ void TypePrinter::printAttributedAfter(const AttributedType *T,
   case attr::ArmMveStrictPolymorphism:
     OS << "__clang_arm_mve_strict_polymorphism";
     break;
-  case attr::Blocking:
-    OS << "clang_blocking";
-    break;
-  case attr::Allocating:
-    OS << "clang_allocating";
-    break;
 
   // Nothing to print for this attribute.
   case attr::HLSLParamModifier:
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index cb3ec0abb8badf..9ccdaeea8695f0 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -18346,7 +18346,7 @@ bool Sema::CheckOverridingFunctionAttributes(CXXMethodDecl *New,
 
   if (OldFT->hasExtParameterInfos()) {
     for (unsigned I = 0, E = OldFT->getNumParams(); I != E; ++I)
-      // A parameter of the overriding method should  be annotated with noescape
+      // A parameter of the overriding method should be annotated with noescape
       // if the corresponding parameter of the overridden method is annotated.
       if (OldFT->getExtParameterInfo(I).isNoEscape() &&
           !NewFT->getExtParameterInfo(I).isNoEscape()) {
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index c960935378156a..8dddc30adb5053 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -8121,7 +8121,7 @@ handleNonBlockingNonAllocatingTypeAttr(TypeProcessingState &TPState,
   }
 #endif
 
-  // nonblocking/nonallocating(true/expr) are represented in a
+  // All forms of the attributes are represented in a
   // FunctionEffectsRef attached to a FunctionProtoType.
   const bool Denied = NewState == FunctionEffectMode::False;
   const FunctionEffect NewEffect(
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index b602975f6c0338..e91f471b72adb8 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -6257,7 +6257,7 @@ QualType TreeTransform<Derived>::TransformFunctionProtoType(
 
   // Transform any function effects with unevaluated conditions.
   // Hold this set in a local for the rest of this function, since EPI
-  // is going to hold a FunctionEffectsRef pointing into it.
+  // may need to hold a FunctionEffectsRef pointing into it.
   std::optional<FunctionEffectSet> NewFX;
   if (ArrayRef FXConds = EPI.FunctionEffects.conditions(); !FXConds.empty()) {
     NewFX.emplace(EPI.FunctionEffects);

>From 65e5b6117fb180959eaeeece92632701b35048a0 Mon Sep 17 00:00:00 2001
From: Doug Wyatt <dwyatt at apple.com>
Date: Thu, 25 Apr 2024 09:43:11 -0700
Subject: [PATCH 40/40] Tests involving nonblocking(expression)

---
 clang/include/clang/AST/Type.h                |  2 +-
 clang/lib/AST/Type.cpp                        |  2 +-
 clang/lib/Sema/AnalysisBasedWarnings.cpp      | 88 ++++++++-----------
 clang/lib/Sema/SemaDecl.cpp                   |  2 +-
 .../Sema/attr-nonblocking-constraints.cpp     | 17 +++-
 5 files changed, 54 insertions(+), 57 deletions(-)

diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index c08e08913750f7..805a0d51af1f7b 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -4482,7 +4482,7 @@ class FunctionEffect {
 public:
   FunctionEffect() : FKind(unsigned(Kind::None)) {}
 
-  FunctionEffect(Kind K) : FKind(unsigned(K)) {}
+  explicit FunctionEffect(Kind K) : FKind(unsigned(K)) {}
 
   /// The kind of the effect.
   Kind kind() const { return Kind(FKind); }
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 750da4f6bdc7a8..ba91fcea2f2adc 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -5053,7 +5053,7 @@ FunctionEffect::Kind FunctionEffect::oppositeKind() const {
   case Kind::Allocating:
     return Kind::NonAllocating;
   case Kind::None:
-    break;
+    return Kind::None;
   }
   llvm_unreachable("unknown effect kind");
 }
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 7aa4acfd3bbd46..c6d2b1c25c1d2f 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -2471,6 +2471,8 @@ class EffectSet {
     using const_iterator = const T *;
     iterator begin() { return &Items[0]; }
     iterator end() { return &Items[Count]; }
+    const_iterator begin() const { return &Items[0]; }
+    const_iterator end() const { return &Items[Count]; }
     const_iterator cbegin() const { return &Items[0]; }
     const_iterator cend() const { return &Items[Count]; }
 
@@ -2493,6 +2495,9 @@ class EffectSet {
 
 public:
   EffectSet() = default;
+  explicit EffectSet(FunctionEffectsRef FX) {
+    insert(FX);
+  }
 
   operator ArrayRef<FunctionEffect>() const {
     return ArrayRef(Impl.cbegin(), Impl.cend());
@@ -2503,10 +2508,25 @@ class EffectSet {
   iterator end() const { return Impl.cend(); }
 
   void insert(const FunctionEffect &Effect);
-  void insert(const EffectSet &Set);
-  void insertIgnoringConditions(const FunctionEffectsRef &FX);
-  bool contains(const FunctionEffect &E) const {
-    return std::find(begin(), end(), E) != end();
+  void insert(const EffectSet &Set) {
+    for (auto &Item : Set) {
+      // push_back because set is already sorted
+      Impl.push_back(Item);
+    }
+  }
+  void insert(FunctionEffectsRef FX) {
+    for (const auto &EC : FX) {
+      assert(EC.Cond.expr() == nullptr); // should be resolved by now, right?
+      // push_back because set is already sorted
+      Impl.push_back(EC.Effect);
+    }
+  }
+  bool contains(const FunctionEffect::Kind EK) const {
+    for (const FunctionEffect &E : Impl) {
+      if (E.kind() == EK)
+        return true;
+    }
+    return false;
   }
 
   void dump(llvm::raw_ostream &OS) const;
@@ -2528,16 +2548,6 @@ void EffectSet::insert(const FunctionEffect &Effect) {
   Impl.insert(Iter, Effect);
 }
 
-void EffectSet::insert(const EffectSet &Set) {
-  for (auto &Item : Set)
-    insert(Item);
-}
-
-void EffectSet::insertIgnoringConditions(const FunctionEffectsRef &FX) {
-  for (const auto &Item : FX)
-    insert(Item.Effect);
-}
-
 LLVM_DUMP_METHOD void EffectSet::dump(llvm::raw_ostream &OS) const {
   OS << "Effects{";
   bool First = true;
@@ -2559,32 +2569,6 @@ EffectSet EffectSet::difference(ArrayRef<FunctionEffect> LHS,
   return Result;
 }
 
-// Represent the declared effects, and absent effects (e.g. nonblocking(false)).
-// Centralize the resolution of computed effects.
-struct CondEffectSet {
-  EffectSet EffectsPresent;
-  EffectSet EffectsExplicitlyAbsent;
-
-  CondEffectSet() = default;
-
-  CondEffectSet(Sema &SemaRef, FunctionEffectsRef FX) {
-    for (const auto Item : FX) {
-      if (Expr *Cond = Item.Cond.expr()) {
-        FunctionEffectMode Mode = FunctionEffectMode::None;
-        ExprResult ER = SemaRef.ActOnEffectExpression(
-            Cond, Mode, /*RequireConstexpr=*/true);
-        if (ER.isInvalid() || Mode == FunctionEffectMode::Dependent)
-          continue;
-        if (Mode == FunctionEffectMode::False) {
-          EffectsExplicitlyAbsent.insert(Item.Effect);
-          continue;
-        }
-      }
-      EffectsPresent.insert(Item.Effect);
-    }
-  }
-};
-
 // Transitory, more extended information about a callable, which can be a
 // function, block, function pointer...
 struct CallableInfo {
@@ -2593,7 +2577,7 @@ struct CallableInfo {
   mutable std::optional<std::string>
       MaybeName; // mutable because built on demand in const method
   SpecialFuncType FuncType = SpecialFuncType::None;
-  CondEffectSet Effects;
+  EffectSet Effects;
   CallType CType = CallType::Unknown;
 
   CallableInfo(Sema &SemaRef, const Decl &CD,
@@ -2621,7 +2605,7 @@ struct CallableInfo {
       // ValueDecl is function, enum, or variable, so just look at its type.
       FXRef = FunctionEffectsRef::get(VD->getType());
     }
-    Effects = CondEffectSet(SemaRef, FXRef);
+    Effects = EffectSet(FXRef);
   }
 
   bool isDirectCall() const {
@@ -2756,14 +2740,13 @@ class PendingFunctionAnalysis {
   PendingFunctionAnalysis(
       Sema &Sem, const CallableInfo &CInfo,
       ArrayRef<FunctionEffect> AllInferrableEffectsToVerify) {
-    DeclaredVerifiableEffects = CInfo.Effects.EffectsPresent;
+    DeclaredVerifiableEffects = CInfo.Effects;
 
     // Check for effects we are not allowed to infer
     EffectSet FX;
 
     for (const auto &effect : AllInferrableEffectsToVerify) {
-      if (effect.canInferOnFunction(*CInfo.CDecl) &&
-          !CInfo.Effects.EffectsExplicitlyAbsent.contains(effect)) {
+      if (effect.canInferOnFunction(*CInfo.CDecl)) {
         FX.insert(effect);
       } else {
         // Add a diagnostic for this effect if a caller were to
@@ -3046,7 +3029,7 @@ class Analyzer {
 
     // If any of the Decl's declared effects forbid throwing (e.g. nonblocking)
     // then the function should also be declared noexcept.
-    for (const auto &Effect : CInfo.Effects.EffectsPresent) {
+    for (const auto &Effect : CInfo.Effects) {
       if (!(Effect.flags() & FunctionEffect::FE_ExcludeThrow))
         continue;
 
@@ -3104,7 +3087,7 @@ class Analyzer {
       emitDiagnostics(*Diags, CInfo, Sem);
     }
     auto *CompletePtr = new CompleteFunctionAnalysis(
-        Sem.getASTContext(), Pending, CInfo.Effects.EffectsPresent,
+        Sem.getASTContext(), Pending, CInfo.Effects,
         AllInferrableEffectsToVerify);
     DeclAnalysis[CInfo.CDecl] = CompletePtr;
     if constexpr (DebugLogLevel > 0) {
@@ -3143,7 +3126,7 @@ class Analyzer {
     const bool DirectCall = Callee.isDirectCall();
 
     // These will be its declared effects.
-    EffectSet CalleeEffects = Callee.Effects.EffectsPresent;
+    EffectSet CalleeEffects = Callee.Effects;
 
     bool IsInferencePossible = DirectCall;
 
@@ -3210,6 +3193,8 @@ class Analyzer {
   // Should only be called when determined to be complete.
   void emitDiagnostics(SmallVector<Diagnostic> &Diags,
                        const CallableInfo &CInfo, Sema &S) {
+    if (Diags.empty())
+      return;
     const SourceManager &SM = S.getSourceManager();
     std::sort(Diags.begin(), Diags.end(),
               [&SM](const Diagnostic &LHS, const Diagnostic &RHS) {
@@ -3290,8 +3275,8 @@ class Analyzer {
               S.Diag(Callee->getLocation(),
                      diag::note_func_effect_call_func_ptr)
                   << effectName;
-            } else if (CalleeInfo.Effects.EffectsExplicitlyAbsent.contains(
-                           Diag.Effect)) {
+            } else if (CalleeInfo.Effects.contains(
+                           Diag.Effect.oppositeKind())) {
               S.Diag(Callee->getLocation(),
                      diag::note_func_effect_call_disallows_inference)
                   << effectName;
@@ -3456,8 +3441,7 @@ class Analyzer {
           CalleeType->getAs<FunctionProtoType>(); // null if FunctionType
       EffectSet CalleeFX;
       if (FPT) {
-        CondEffectSet CFE(Outer.Sem, FPT->getFunctionEffects());
-        CalleeFX.insert(CFE.EffectsPresent);
+        CalleeFX.insert(FPT->getFunctionEffects());
       }
 
       auto check1Effect = [&](const FunctionEffect &Effect, bool Inferring) {
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 186f7a0e3a1ea9..aaadb41d1beee6 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11167,7 +11167,7 @@ void Sema::maybeAddDeclWithEffects(const Decl *D,
   if (hasUncompilableErrorOccurred())
     return;
 
-  // For code in dependent contexts, we'll do this at instantiation time
+  // For code in dependent contexts, we'll do this at instantiation time.
   // Without this check, we would analyze the function based on placeholder
   // template parameters, and potentially generate spurious diagnostics.
   if (cast<DeclContext>(D)->isDependentContext()) {
diff --git a/clang/test/Sema/attr-nonblocking-constraints.cpp b/clang/test/Sema/attr-nonblocking-constraints.cpp
index a273beac1baf73..21d14a2998c389 100644
--- a/clang/test/Sema/attr-nonblocking-constraints.cpp
+++ b/clang/test/Sema/attr-nonblocking-constraints.cpp
@@ -134,13 +134,26 @@ void nl10(
 }
 
 // Interactions with nonblocking(false)
-void nl11_no_inference() [[clang::nonblocking(false)]] // expected-note {{function does not permit inference of 'nonblocking'}}
+void nl11_no_inference_1() [[clang::nonblocking(false)]] // expected-note {{function does not permit inference of 'nonblocking'}}
 {
 }
+void nl11_no_inference_2() [[clang::nonblocking(false)]]; // expected-note {{function does not permit inference of 'nonblocking'}}
+
+template <bool V>
+struct ComputedNB {
+	void method() [[clang::nonblocking(V)]]; // expected-note {{function does not permit inference of 'nonblocking'}}
+};
 
 void nl11() [[clang::nonblocking]]
 {
-	nl11_no_inference(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
+	nl11_no_inference_1(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
+	nl11_no_inference_2(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
+
+	ComputedNB<true> CNB_true;
+	CNB_true.method();
+	
+	ComputedNB<false> CNB_false;
+	CNB_false.method(); // expected-warning {{'nonblocking' function must not call non-'nonblocking' function}}
 }
 
 // Verify that when attached to a redeclaration, the attribute successfully attaches.



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