[clang] Reapply "[Clang] Fix a number of issues involving expansion statements" (#220375) (PR #223005)

via cfe-commits cfe-commits at lists.llvm.org
Fri Sep 11 11:15:35 PDT 2026


llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-coroutines

Author: Ambrose Leeb (Sirraide)

<details>
<summary>Changes</summary>

This reverts 7c44c505cd7688a8994779f1751e0f9b4b95ab4c and relands #<!-- -->217110.

There were two tests that needed updating: one because a warning that had previously been erroneously suppressed (because we thought we weren’t in a function) now works properly, and another because it crashes due to an unrelated bug. I’ve filed #<!-- -->223003 for the latter and moved the crash into a separate XFAIL test so it can be reenabled when the bug is fixed.

The plan was to backport this to the 23 release branch, so still no release note.

---

Patch is 25.76 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/223005.diff


14 Files Affected:

- (modified) clang/include/clang/AST/DeclBase.h (+26) 
- (modified) clang/include/clang/AST/DeclCXX.h (+1-1) 
- (modified) clang/lib/AST/Decl.cpp (+1-3) 
- (modified) clang/lib/Sema/SemaChecking.cpp (+3-2) 
- (modified) clang/lib/Sema/SemaCoroutine.cpp (+7-9) 
- (modified) clang/lib/Sema/SemaDecl.cpp (+2-1) 
- (modified) clang/lib/Sema/SemaDeclCXX.cpp (+24-6) 
- (modified) clang/lib/Sema/SemaExpr.cpp (+2-1) 
- (modified) clang/test/Parser/cxx2c-expansion-statements.cpp (+2-2) 
- (modified) clang/test/SemaCXX/cxx2c-expansion-stmts-control-flow.cpp (+1-1) 
- (added) clang/test/SemaCXX/cxx2c-expansion-stmts-warnings.cpp (+16) 
- (modified) clang/test/SemaCXX/cxx2c-expansion-stmts.cpp (+200) 
- (modified) clang/test/SemaCXX/expansion-statements-local-extern-decls.cpp (+4-22) 
- (added) clang/test/SemaCXX/expansion-statements-local-extern-if-constexpr.cpp (+19) 


``````````diff
diff --git a/clang/include/clang/AST/DeclBase.h b/clang/include/clang/AST/DeclBase.h
index 9d233be282dbb..a067d87e92a84 100644
--- a/clang/include/clang/AST/DeclBase.h
+++ b/clang/include/clang/AST/DeclBase.h
@@ -2175,12 +2175,16 @@ class DeclContext {
     }
   }
 
+  /// Returns true if this DeclContext is a function, Objective-C method,
+  /// or block, or a DeclContext that can only occur in or is conceptually
+  /// treated like a function.
   bool isFunctionOrMethod() const {
     switch (getDeclKind()) {
     case Decl::Block:
     case Decl::Captured:
     case Decl::ObjCMethod:
     case Decl::TopLevelStmt:
+    case Decl::CXXExpansionStmt:
       return true;
     default:
       return getDeclKind() >= Decl::firstFunction &&
@@ -2188,6 +2192,28 @@ class DeclContext {
     }
   }
 
+  /// Cast this to a FunctionDecl if it is one, ignoring any intervening
+  /// expansion statements. Returns nullptr if this is not a function.
+  ///
+  /// In particular, this will return nullptr if the *nearest* enclosing
+  /// DeclContext that is not an expansion statement is something other
+  /// than a function (e.g. a CXXRecordDecl, even if it is a local class).
+  FunctionDecl *getEnclosingFunction() {
+    return dyn_cast<FunctionDecl>(getEnclosingNonExpansionStatementContext());
+  }
+
+  const FunctionDecl *getEnclosingFunction() const {
+    return dyn_cast<FunctionDecl>(getEnclosingNonExpansionStatementContext());
+  }
+
+  FunctionDecl *castEnclosingFunction() {
+    return cast<FunctionDecl>(getEnclosingNonExpansionStatementContext());
+  }
+
+  const FunctionDecl *castEnclosingFunction() const {
+    return cast<FunctionDecl>(getEnclosingNonExpansionStatementContext());
+  }
+
   /// Test whether the context supports looking up names.
   bool isLookupContext() const {
     return !isFunctionOrMethod() && getDeclKind() != Decl::LinkageSpec &&
diff --git a/clang/include/clang/AST/DeclCXX.h b/clang/include/clang/AST/DeclCXX.h
index afe46fae1bceb..ff2223070dc15 100644
--- a/clang/include/clang/AST/DeclCXX.h
+++ b/clang/include/clang/AST/DeclCXX.h
@@ -1578,7 +1578,7 @@ class CXXRecordDecl : public RecordDecl {
     if (const auto *RD = dyn_cast<CXXRecordDecl>(getDeclContext()))
       return RD->isLocalClass();
 
-    return dyn_cast<FunctionDecl>(getDeclContext());
+    return getDeclContext()->getEnclosingFunction();
   }
 
   FunctionDecl *isLocalClass() {
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index d1d296dd60d14..18808942128e6 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -1567,9 +1567,7 @@ LinkageInfo LinkageComputer::computeLVForDecl(const NamedDecl *D,
   //   one such matching entity, the program is ill-formed. Otherwise,
   //   if no matching entity is found, the block scope entity receives
   //   external linkage.
-  if (D->getDeclContext()
-          ->getEnclosingNonExpansionStatementContext()
-          ->isFunctionOrMethod())
+  if (D->getDeclContext()->isFunctionOrMethod())
     return getLVForLocalDecl(D, computation);
 
   // C++ [basic.link]p6:
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 25996ddbc0558..ee7af4a68a84b 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -6186,7 +6186,8 @@ static bool checkVAStartIsInVariadicFunction(Sema &S, Expr *Fn,
   // and get its parameter list.
   bool IsVariadic = false;
   ArrayRef<ParmVarDecl *> Params;
-  DeclContext *Caller = S.CurContext;
+  DeclContext *Caller =
+      S.CurContext->getEnclosingNonExpansionStatementContext();
   if (auto *Block = dyn_cast<BlockDecl>(Caller)) {
     IsVariadic = Block->isVariadic();
     Params = Block->parameters();
@@ -7841,7 +7842,7 @@ static bool CheckMissingFormatAttribute(
   if (S->getDiagnostics().isIgnored(diag::warn_missing_format_attribute, Loc))
     return false;
 
-  DeclContext *DC = S->CurContext;
+  DeclContext *DC = S->CurContext->getEnclosingNonExpansionStatementContext();
   if (!isa<ObjCMethodDecl>(DC) && !isa<FunctionDecl>(DC) && !isa<BlockDecl>(DC))
     return false;
   Decl *Caller = cast<Decl>(DC)->getCanonicalDecl();
diff --git a/clang/lib/Sema/SemaCoroutine.cpp b/clang/lib/Sema/SemaCoroutine.cpp
index d22260b887415..d68a9ec2d8f35 100644
--- a/clang/lib/Sema/SemaCoroutine.cpp
+++ b/clang/lib/Sema/SemaCoroutine.cpp
@@ -186,7 +186,7 @@ static bool isValidCoroutineContext(Sema &S, SourceLocation Loc,
   // appear in a default argument." But the diagnostic QoI here could be
   // improved to inform the user that default arguments specifically are not
   // allowed.
-  auto *FD = dyn_cast<FunctionDecl>(S.CurContext);
+  auto FD = S.CurContext->getEnclosingFunction();
   if (!FD) {
     S.Diag(Loc, isa<ObjCMethodDecl>(S.CurContext)
                     ? diag::err_coroutine_objc_method
@@ -470,8 +470,7 @@ static void markCoroutineParametersReferenced(FunctionDecl &FD) {
 }
 
 VarDecl *Sema::buildCoroutinePromise(SourceLocation Loc) {
-  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
-  auto *FD = cast<FunctionDecl>(CurContext);
+  auto *FD = CurContext->castEnclosingFunction();
   bool IsThisDependentType = [&] {
     if (const auto *MD = dyn_cast_if_present<CXXMethodDecl>(FD))
       return MD->isImplicitObjectMemberFunction() &&
@@ -583,7 +582,7 @@ static FunctionScopeInfo *checkCoroutineContext(Sema &S, SourceLocation Loc,
   if (!isValidCoroutineContext(S, Loc, Keyword))
     return nullptr;
 
-  assert(isa<FunctionDecl>(S.CurContext) && "not in a function scope");
+  assert(S.CurContext->getEnclosingFunction() && "not in a function scope");
 
   auto *ScopeInfo = S.getCurFunction();
   assert(ScopeInfo && "missing function scope for function");
@@ -630,7 +629,7 @@ static void checkNoThrow(Sema &S, const Stmt *E,
         //   potentially-throwing ([except.spec]).
         //
         // First time seeing an error, emit the error message.
-        S.Diag(cast<FunctionDecl>(S.CurContext)->getLocation(),
+        S.Diag(S.CurContext->castEnclosingFunction()->getLocation(),
                diag::err_coroutine_promise_final_suspend_requires_nothrow);
       }
       ThrowingDecls.insert(D);
@@ -701,7 +700,7 @@ bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc,
   // Ignore previous expr evaluation contexts.
   EnterExpressionEvaluationContextForFunction PotentiallyEvaluated(
       *this, Sema::ExpressionEvaluationContext::PotentiallyEvaluated,
-      dyn_cast_or_null<FunctionDecl>(CurContext));
+      CurContext->getEnclosingFunction());
 
   if (!checkCoroutineContext(*this, KWLoc, Keyword))
     return false;
@@ -726,7 +725,7 @@ bool Sema::ActOnCoroutineBodyStart(Scope *SC, SourceLocation KWLoc,
 
   ScopeInfo->setNeedsCoroutineSuspends(false);
 
-  auto *Fn = cast<FunctionDecl>(CurContext);
+  auto *Fn = CurContext->castEnclosingFunction();
   SourceLocation Loc = Fn->getLocation();
   // Build the initial suspend point
   auto buildSuspends = [&](StringRef Name) mutable -> StmtResult {
@@ -2008,8 +2007,7 @@ static VarDecl *buildVarDecl(Sema &S, SourceLocation Loc, QualType Type,
 // Build statements that move coroutine function parameters to the coroutine
 // frame, and store them on the function scope info.
 bool Sema::buildCoroutineParameterMoves(SourceLocation Loc) {
-  assert(isa<FunctionDecl>(CurContext) && "not in a function scope");
-  auto *FD = cast<FunctionDecl>(CurContext);
+  auto *FD = CurContext->castEnclosingFunction();
 
   auto *ScopeInfo = getCurFunction();
   if (!ScopeInfo->CoroutineParameterMoves.empty())
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 5de5821fe263e..742bb01a4ba81 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -6430,6 +6430,7 @@ bool Sema::diagnoseQualifiedDeclaration(CXXScopeSpec &SS, DeclContext *DC,
   // declaration. For a template-id, we perform the checks in
   // CheckTemplateSpecializationScope.
   if (!Cur->Encloses(DC) && !(TemplateId || IsMemberSpecialization)) {
+    Cur = Cur->getEnclosingNonExpansionStatementContext();
     if (Cur->isRecord())
       Diag(Loc, diag::err_member_qualification)
         << Name << SS.getRange();
@@ -7558,7 +7559,7 @@ static bool hasParsedAttr(Scope *S, const Declarator &PD,
 }
 
 bool Sema::adjustContextForLocalExternDecl(DeclContext *&DC) {
-  if (!DC->getEnclosingNonExpansionStatementContext()->isFunctionOrMethod())
+  if (!DC->isFunctionOrMethod())
     return false;
 
   // If this is a local extern function or variable declared within a function
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index ea628f29d8a00..7aa1368619608 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -640,7 +640,9 @@ bool Sema::MergeCXXFunctionDecl(FunctionDecl *New, FunctionDecl *Old,
           << (New->getTemplateSpecializationKind() ==TSK_ExplicitSpecialization)
           << New->getDeclName()
           << NewParam->getDefaultArgRange();
-      } else if (New->getDeclContext()->isDependentContext()) {
+      } else if (New->getDeclContext()
+                     ->getEnclosingNonExpansionStatementContext()
+                     ->isDependentContext()) {
         // C++ [dcl.fct.default]p6 (DR217):
         //   Default arguments for a member function of a class template shall
         //   be specified on the initial declaration of the member function
@@ -2074,9 +2076,6 @@ static bool CheckConstexprDeclStmt(Sema &SemaRef, const FunctionDecl *Dcl,
       //   - using-enum-declaration
       continue;
 
-    case Decl::CXXExpansionStmt:
-      continue;
-
     case Decl::Typedef:
     case Decl::TypeAlias: {
       //   - typedef declarations and alias-declarations that do not define
@@ -2263,15 +2262,34 @@ CheckConstexprFunctionStmt(Sema &SemaRef, const FunctionDecl *Dcl, Stmt *S,
     //   - null statements,
     return true;
 
-  case Stmt::DeclStmtClass:
+  case Stmt::DeclStmtClass: {
+    auto *DS = cast<DeclStmt>(S);
+
+    // Expansion statement 'declarations' have substatements, so we need to
+    // handle them separately.
+    if (DS->isSingleDecl()) {
+      if (auto *ESD = dyn_cast<CXXExpansionStmtDecl>(DS->getSingleDecl())) {
+        // Don't check unexpanded expansion statements.
+        if (!ESD->getInstantiations())
+          return true;
+        for (auto *BodyIt : ESD->getInstantiations()->getInstantiations()) {
+          if (!CheckConstexprFunctionStmt(SemaRef, Dcl, BodyIt, ReturnStmts,
+                                          Cxx1yLoc, Cxx2aLoc, Cxx2bLoc, Kind))
+            return false;
+        }
+        return true;
+      }
+    }
+
     //   - static_assert-declarations
     //   - using-declarations,
     //   - using-directives,
     //   - typedef declarations and alias-declarations that do not define
     //     classes or enumerations,
-    if (!CheckConstexprDeclStmt(SemaRef, Dcl, cast<DeclStmt>(S), Cxx1yLoc, Kind))
+    if (!CheckConstexprDeclStmt(SemaRef, Dcl, DS, Cxx1yLoc, Kind))
       return false;
     return true;
+  }
 
   case Stmt::ReturnStmtClass:
     //   - and exactly one return statement;
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 7186aa86fae1e..fba46ef56625b 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -19473,7 +19473,8 @@ void Sema::MarkCaptureUsedInEnclosingContext(ValueDecl *Capture,
 static void diagnoseUncapturableValueReferenceOrBinding(Sema &S,
                                                         SourceLocation loc,
                                                         ValueDecl *var) {
-  DeclContext *VarDC = var->getDeclContext();
+  DeclContext *VarDC =
+      var->getDeclContext()->getEnclosingNonExpansionStatementContext();
 
   //  If the parameter still belongs to the translation unit, then
   //  we're actually just using one parameter in the declaration of
diff --git a/clang/test/Parser/cxx2c-expansion-statements.cpp b/clang/test/Parser/cxx2c-expansion-statements.cpp
index 736f9fead383c..3a28b3268fd7a 100644
--- a/clang/test/Parser/cxx2c-expansion-statements.cpp
+++ b/clang/test/Parser/cxx2c-expansion-statements.cpp
@@ -23,7 +23,7 @@ void bad() {
   template for (__private_extern__ auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'extern'}}
   template for (extern static auto y : {1, 2}); // expected-error {{cannot combine with previous 'extern' declaration specifier}} expected-error {{expansion variable 'y' may not be declared 'extern'}}
   template for (static auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'static'}}
-  template for (thread_local auto y : {1, 2}); // expected-error {{'thread_local' variables must have global storage}}
+  template for (thread_local auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'thread_local'}}
   template for (static thread_local auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'thread_local'}}
   template for (__thread auto y : {1, 2}); // expected-error {{'__thread' variables must have global storage}}
   template for (static __thread auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'static'}}
@@ -32,7 +32,7 @@ void bad() {
   template for (int x; extern auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'extern'}}
   template for (int x; extern static auto y : {1, 2}); // expected-error {{cannot combine with previous 'extern' declaration specifier}} expected-error {{expansion variable 'y' may not be declared 'extern'}}
   template for (int x; static auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'static'}}
-  template for (int x; thread_local auto y : {1, 2}); // expected-error {{'thread_local' variables must have global storage}}
+  template for (int x; thread_local auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'thread_local'}}
   template for (int x; static thread_local auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'thread_local'}}
   template for (int x; __thread auto y : {1, 2}); // expected-error {{'__thread' variables must have global storage}}
   template for (int x; static __thread auto y : {1, 2}); // expected-error {{expansion variable 'y' may not be declared 'static'}}
diff --git a/clang/test/SemaCXX/cxx2c-expansion-stmts-control-flow.cpp b/clang/test/SemaCXX/cxx2c-expansion-stmts-control-flow.cpp
index 1001abae5f6ef..3a8bcb3075106 100644
--- a/clang/test/SemaCXX/cxx2c-expansion-stmts-control-flow.cpp
+++ b/clang/test/SemaCXX/cxx2c-expansion-stmts-control-flow.cpp
@@ -120,7 +120,7 @@ void GH210575(int i) {
   switch (i) {
     template for (auto x : {1, 2}) {
       switch (i) {
-        bar baz(); // expected-error {{unknown type name 'bar'}}
+        bar baz(); // expected-error {{unknown type name 'bar'}} expected-warning {{empty parentheses interpreted as a function declaration}} expected-note {{replace parentheses with an initializer to declare a variable}}
       }
     }
   }
diff --git a/clang/test/SemaCXX/cxx2c-expansion-stmts-warnings.cpp b/clang/test/SemaCXX/cxx2c-expansion-stmts-warnings.cpp
new file mode 100644
index 0000000000000..6ef468f2cd1fb
--- /dev/null
+++ b/clang/test/SemaCXX/cxx2c-expansion-stmts-warnings.cpp
@@ -0,0 +1,16 @@
+// RUN: %clang_cc1 %s -std=c++2c -fsyntax-only -verify=expected,old-interp
+// RUN: %clang_cc1 %s -std=c++2c -fsyntax-only -verify=expected,new-interp -fexperimental-new-constant-interpreter
+
+// Test that checks for warnings that should be emitted in expansion statements,
+// but which are suppressed if we saw an error (which is why they're in a separate
+// file).
+
+#pragma GCC diagnostic warning "-Wunused-variable"
+#pragma GCC diagnostic warning "-Wunused-local-typedefs"
+void unused() {
+  template for (int init_stmt; int expansion_var : {0}) { // expected-warning {{unused variable 'init_stmt'}} expected-warning {{unused variable 'expansion_var'}}
+    int unused_var; // expected-warning {{unused variable 'unused_var'}}
+    using unused_type = int; // expected-warning {{unused type alias 'unused_type'}}
+    typedef int unused_typedef; // expected-warning {{unused typedef 'unused_typedef'}}
+  }
+}
diff --git a/clang/test/SemaCXX/cxx2c-expansion-stmts.cpp b/clang/test/SemaCXX/cxx2c-expansion-stmts.cpp
index dd450a8f1b76c..44189ff31dae8 100644
--- a/clang/test/SemaCXX/cxx2c-expansion-stmts.cpp
+++ b/clang/test/SemaCXX/cxx2c-expansion-stmts.cpp
@@ -1607,3 +1607,203 @@ T tf() {
 
 template long tf<long>();
 }
+
+// Boilerplate needed for tests involving coroutines
+namespace std {
+template <class... Args>
+struct void_t_imp {
+  using type = void;
+};
+template <class... Args>
+using void_t = typename void_t_imp<Args...>::type;
+
+template <class T, class = void>
+struct traits_sfinae_base {};
+
+template <class T>
+struct traits_sfinae_base<T, void_t<typename T::promise_type>> {
+  using promise_type = typename T::promise_type;
+};
+
+template <class Ret, class... Args>
+struct coroutine_traits : public traits_sfinae_base<Ret> {};
+
+template <class PromiseType = void>
+struct coroutine_handle {
+  static coroutine_handle from_address(void *) noexcept;
+  static coroutine_handle from_promise(PromiseType &promise);
+};
+template <>
+struct coroutine_handle<void> {
+  template <class PromiseType>
+  coroutine_handle(coroutine_handle<PromiseType>) noexcept;
+  static coroutine_handle from_address(void *) noexcept;
+  template <class PromiseType>
+  static coroutine_handle from_promise(PromiseType &promise);
+};
+
+struct suspend_always {
+  bool await_ready() noexcept { return false; }
+  template <typename F>
+  void await_suspend(F) noexcept;
+  void await_resume() noexcept {}
+};
+
+struct suspend_never {
+  bool await_ready() noexcept { return true; }
+  template <typename F>
+  void await_suspend(F) noexcept;
+  void await_resume() noexcept {}
+};
+} // namespace std
+
+struct task {
+  struct promise_type {
+    task get_return_object() { return {}; }
+    std::suspend_never initial_suspend() noexcept { return {}; }
+    std::suspend_never final_suspend() noexcept { return {}; }
+    void return_void() {}
+    std::suspend_never yield_value(int) { return {}; }
+    void unhandled_exception() {}
+  };
+};
+
+namespace decl_context_issues {
+void local_class() {
+  template for (int x : {0}) {
+    struct Local {
+      template <class T> // expected-error {{templates cannot be declared inside of a local class}}
+      void member(T) {}
+    };
+
+    template for (int y : {1}) {
+      struct Nested {
+        template <class T> // expected-error {{templates cannot be declared inside of a local class}}
+        void member(T) {}
+      };
+    }
+  }
+
+  template for (int x : {}) {
+    struct DiscardedLocal {
+      template <class T> // expected-error {{templates cannot be declared inside of a local class}}
+      void member(T) {}
+    };
+  }
+}
+
+void thread_local_var() {
+  template for (int x : {0}) {
+    thread_local int v1;
+    __thread int v2; // expected-error {{'__thread' variables must have global storage}}
+    static __thread int v3;
+  }
+}
+
+task coro() {
+  template for (int x : {0}) {
+    co_await std::suspend_never{};
+    co_yield 1;
+    co_return;
+  }
+  co_return;
+}
+
+task coro_discarded() {
+  template for (int x : {}) {
+    co_await std::suspend_never{}; // expected-note {{function is a coroutine due to use of 'co_await' here}}
+  }
+
+  // This is a coroutine even though the co_await above is discarded.
+  return task(); // expected-error {{return statement not allowed in coroutine; did you mean 'co_return'?}}
+}
+
+void inline_static() {
+  template for (int x : {0}) {
+    inline int y = x; // expected-error {{inline declaration of 'y' not allowed in block scope}}
+    inline void f1(); // expected-error {{inline declaration of 'f1' not allowed in block scope}}
+    static void f2(); // expected-error {{function declared in block scope cannot have 'static' storage class}}
+  }
+}
+
+struct VexingParse {};
+void vexing_parse() {
+  template for (int x : {}) {
+    VexingParse v(); // expected-warning {{empty parentheses interpreted as a function declaration}} expected-note {{remove parentheses to declare a variable}}
+  }
+}
+
+void builtin_va_start(int x, ...) {
+  __builtin_va_list ap;
+  template for (int y : {1}) {
+    __builtin_va_start(...
[truncated]

``````````

</details>


https://github.com/llvm/llvm-project/pull/223005


More information about the cfe-commits mailing list