r329617 - [ObjC++] Never pass structs that transitively contain __weak fields in
Akira Hatanaka via cfe-commits
cfe-commits at lists.llvm.org
Mon Apr 9 13:39:47 PDT 2018
Author: ahatanak
Date: Mon Apr 9 13:39:47 2018
New Revision: 329617
URL: http://llvm.org/viewvc/llvm-project?rev=329617&view=rev
Log:
[ObjC++] Never pass structs that transitively contain __weak fields in
registers.
This patch fixes a bug in r328731 that caused structs transitively
containing __weak fields to be passed in registers. The patch replaces
the flag RecordDecl::CanPassInRegisters with a 2-bit enum that indicates
whether the struct or structs containing the struct are forced to be
passed indirectly.
rdar://problem/39194693
Modified:
cfe/trunk/include/clang/AST/Decl.h
cfe/trunk/include/clang/AST/Type.h
cfe/trunk/lib/AST/Decl.cpp
cfe/trunk/lib/AST/DeclCXX.cpp
cfe/trunk/lib/AST/Type.cpp
cfe/trunk/lib/Sema/SemaDecl.cpp
cfe/trunk/lib/Sema/SemaDeclCXX.cpp
cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
cfe/trunk/lib/Serialization/ASTWriter.cpp
cfe/trunk/lib/Serialization/ASTWriterDecl.cpp
cfe/trunk/test/CodeGenObjCXX/objc-struct-cxx-abi.mm
Modified: cfe/trunk/include/clang/AST/Decl.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Decl.h?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Decl.h (original)
+++ cfe/trunk/include/clang/AST/Decl.h Mon Apr 9 13:39:47 2018
@@ -3541,6 +3541,31 @@ public:
/// union Y { int A, B; }; // Has body with members A and B (FieldDecls).
/// This decl will be marked invalid if *any* members are invalid.
class RecordDecl : public TagDecl {
+public:
+ /// Enum that represents the different ways arguments are passed to and
+ /// returned from function calls. This takes into account the target-specific
+ /// and version-specific rules along with the rules determined by the
+ /// language.
+ enum ArgPassingKind {
+ /// The argument of this type can be passed directly in registers.
+ APK_CanPassInRegs,
+
+ /// The argument of this type cannot be passed directly in registers.
+ /// Records containing this type as a subobject are not forced to be passed
+ /// indirectly. This value is used only in C++. This value is required by
+ /// C++ because, in uncommon situations, it is possible for a class to have
+ /// only trivial copy/move constructors even when one of its subobjects has
+ /// a non-trivial copy/move constructor (if e.g. the corresponding copy/move
+ /// constructor in the derived class is deleted).
+ APK_CannotPassInRegs,
+
+ /// The argument of this type cannot be passed directly in registers.
+ /// Records containing this type as a subobject are forced to be passed
+ /// indirectly.
+ APK_CanNeverPassInRegs
+ };
+
+private:
friend class DeclContext;
// FIXME: This can be packed into the bitfields in Decl.
@@ -3571,17 +3596,14 @@ class RecordDecl : public TagDecl {
bool NonTrivialToPrimitiveCopy : 1;
bool NonTrivialToPrimitiveDestroy : 1;
- /// True if this class can be passed in a non-address-preserving fashion
- /// (such as in registers).
- /// This does not imply anything about how the ABI in use will actually
- /// pass an object of this class.
- bool CanPassInRegisters : 1;
-
/// Indicates whether this struct is destroyed in the callee. This flag is
/// meaningless when Microsoft ABI is used since parameters are always
/// destroyed in the callee.
bool ParamDestroyedInCallee : 1;
+ /// Represents the way this type is passed to a function.
+ ArgPassingKind ArgPassingRestrictions : 2;
+
protected:
RecordDecl(Kind DK, TagKind TK, const ASTContext &C, DeclContext *DC,
SourceLocation StartLoc, SourceLocation IdLoc,
@@ -3669,12 +3691,15 @@ public:
/// it must have at least one trivial, non-deleted copy or move constructor.
/// FIXME: This should be set as part of completeDefinition.
bool canPassInRegisters() const {
- return CanPassInRegisters;
+ return ArgPassingRestrictions == APK_CanPassInRegs;
+ }
+
+ ArgPassingKind getArgPassingRestrictions() const {
+ return ArgPassingRestrictions;
}
- /// Set that we can pass this RecordDecl in registers.
- void setCanPassInRegisters(bool CanPass) {
- CanPassInRegisters = CanPass;
+ void setArgPassingRestrictions(ArgPassingKind Kind) {
+ ArgPassingRestrictions = Kind;
}
bool isParamDestroyedInCallee() const {
Modified: cfe/trunk/include/clang/AST/Type.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/Type.h?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/Type.h (original)
+++ cfe/trunk/include/clang/AST/Type.h Mon Apr 9 13:39:47 2018
@@ -1149,8 +1149,6 @@ public:
/// source object is placed in an uninitialized state.
PrimitiveCopyKind isNonTrivialToPrimitiveDestructiveMove() const;
- bool canPassInRegisters() const;
-
enum DestructionKind {
DK_none,
DK_cxx_destructor,
Modified: cfe/trunk/lib/AST/Decl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Decl.cpp?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Decl.cpp (original)
+++ cfe/trunk/lib/AST/Decl.cpp Mon Apr 9 13:39:47 2018
@@ -3956,7 +3956,7 @@ RecordDecl::RecordDecl(Kind DK, TagKind
LoadedFieldsFromExternalStorage(false),
NonTrivialToPrimitiveDefaultInitialize(false),
NonTrivialToPrimitiveCopy(false), NonTrivialToPrimitiveDestroy(false),
- CanPassInRegisters(true), ParamDestroyedInCallee(false) {
+ ParamDestroyedInCallee(false), ArgPassingRestrictions(APK_CanPassInRegs) {
assert(classof(static_cast<Decl*>(this)) && "Invalid Kind!");
}
Modified: cfe/trunk/lib/AST/DeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/DeclCXX.cpp?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/lib/AST/DeclCXX.cpp (original)
+++ cfe/trunk/lib/AST/DeclCXX.cpp Mon Apr 9 13:39:47 2018
@@ -421,6 +421,10 @@ CXXRecordDecl::setBases(CXXBaseSpecifier
if (BaseClassDecl->hasVolatileMember())
setHasVolatileMember(true);
+ if (BaseClassDecl->getArgPassingRestrictions() ==
+ RecordDecl::APK_CanNeverPassInRegs)
+ setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
+
// Keep track of the presence of mutable fields.
if (BaseClassDecl->hasMutableFields()) {
data().HasMutableFields = true;
@@ -950,7 +954,7 @@ void CXXRecordDecl::addedMember(Decl *D)
// Structs with __weak fields should never be passed directly.
if (LT == Qualifiers::OCL_Weak)
- setCanPassInRegisters(false);
+ setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
Data.HasIrrelevantDestructor = false;
} else if (!Context.getLangOpts().ObjCAutoRefCount) {
@@ -1117,6 +1121,9 @@ void CXXRecordDecl::addedMember(Decl *D)
setHasObjectMember(true);
if (FieldRec->hasVolatileMember())
setHasVolatileMember(true);
+ if (FieldRec->getArgPassingRestrictions() ==
+ RecordDecl::APK_CanNeverPassInRegs)
+ setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
// C++0x [class]p7:
// A standard-layout class is a class that:
Modified: cfe/trunk/lib/AST/Type.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Type.cpp?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Type.cpp (original)
+++ cfe/trunk/lib/AST/Type.cpp Mon Apr 9 13:39:47 2018
@@ -2239,17 +2239,6 @@ QualType::isNonTrivialToPrimitiveDestruc
return isNonTrivialToPrimitiveCopy();
}
-bool QualType::canPassInRegisters() const {
- if (const auto *RT =
- getTypePtr()->getBaseElementTypeUnsafe()->getAs<RecordType>())
- return RT->getDecl()->canPassInRegisters();
-
- if (getQualifiers().getObjCLifetime() == Qualifiers::OCL_Weak)
- return false;
-
- return true;
-}
-
bool Type::isLiteralType(const ASTContext &Ctx) const {
if (isDependentType())
return false;
Modified: cfe/trunk/lib/Sema/SemaDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDecl.cpp?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDecl.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDecl.cpp Mon Apr 9 13:39:47 2018
@@ -15465,8 +15465,13 @@ void Sema::ActOnFields(Scope *S, SourceL
Record->setNonTrivialToPrimitiveDestroy(true);
Record->setParamDestroyedInCallee(true);
}
- if (!FT.canPassInRegisters())
- Record->setCanPassInRegisters(false);
+
+ if (const auto *RT = FT->getAs<RecordType>()) {
+ if (RT->getDecl()->getArgPassingRestrictions() ==
+ RecordDecl::APK_CanNeverPassInRegs)
+ Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
+ } else if (FT.getQualifiers().getObjCLifetime() == Qualifiers::OCL_Weak)
+ Record->setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
}
if (Record && FD->getType().isVolatileQualified())
Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Mon Apr 9 13:39:47 2018
@@ -5847,20 +5847,20 @@ static bool paramCanBeDestroyedInCallee(
return HasNonDeletedCopyOrMove;
}
-static bool computeCanPassInRegister(bool DestroyedInCallee,
- const CXXRecordDecl *RD,
- TargetInfo::CallingConvKind CCK,
- Sema &S) {
+static RecordDecl::ArgPassingKind
+computeArgPassingRestrictions(bool DestroyedInCallee, const CXXRecordDecl *RD,
+ TargetInfo::CallingConvKind CCK, Sema &S) {
if (RD->isDependentType() || RD->isInvalidDecl())
- return true;
+ return RecordDecl::APK_CanPassInRegs;
- // The param cannot be passed in registers if CanPassInRegisters is already
- // set to false.
- if (!RD->canPassInRegisters())
- return false;
+ // The param cannot be passed in registers if ArgPassingRestrictions is set to
+ // APK_CanNeverPassInRegs.
+ if (RD->getArgPassingRestrictions() == RecordDecl::APK_CanNeverPassInRegs)
+ return RecordDecl::APK_CanNeverPassInRegs;
if (CCK != TargetInfo::CCK_MicrosoftX86_64)
- return DestroyedInCallee;
+ return DestroyedInCallee ? RecordDecl::APK_CanPassInRegs
+ : RecordDecl::APK_CannotPassInRegs;
bool CopyCtorIsTrivial = false, CopyCtorIsTrivialForCall = false;
bool DtorIsTrivialForCall = false;
@@ -5900,7 +5900,7 @@ static bool computeCanPassInRegister(boo
// If the copy ctor and dtor are both trivial-for-calls, pass direct.
if (CopyCtorIsTrivialForCall && DtorIsTrivialForCall)
- return true;
+ return RecordDecl::APK_CanPassInRegs;
// If a class has a destructor, we'd really like to pass it indirectly
// because it allows us to elide copies. Unfortunately, MSVC makes that
@@ -5914,8 +5914,8 @@ static bool computeCanPassInRegister(boo
// passed in registers, which is non-conforming.
if (CopyCtorIsTrivial &&
S.getASTContext().getTypeSize(RD->getTypeForDecl()) <= 64)
- return true;
- return false;
+ return RecordDecl::APK_CanPassInRegs;
+ return RecordDecl::APK_CannotPassInRegs;
}
/// \brief Perform semantic checks on a class definition that has been
@@ -6090,8 +6090,8 @@ void Sema::CheckCompletedCXXClass(CXXRec
if (Record->hasNonTrivialDestructor())
Record->setParamDestroyedInCallee(DestroyedInCallee);
- Record->setCanPassInRegisters(
- computeCanPassInRegister(DestroyedInCallee, Record, CCK, *this));
+ Record->setArgPassingRestrictions(
+ computeArgPassingRestrictions(DestroyedInCallee, Record, CCK, *this));
}
/// Look up the special member function that would be called by a special
Modified: cfe/trunk/lib/Serialization/ASTReaderDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTReaderDecl.cpp?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTReaderDecl.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTReaderDecl.cpp Mon Apr 9 13:39:47 2018
@@ -742,8 +742,8 @@ ASTDeclReader::VisitRecordDeclImpl(Recor
RD->setNonTrivialToPrimitiveDefaultInitialize(Record.readInt());
RD->setNonTrivialToPrimitiveCopy(Record.readInt());
RD->setNonTrivialToPrimitiveDestroy(Record.readInt());
- RD->setCanPassInRegisters(Record.readInt());
RD->setParamDestroyedInCallee(Record.readInt());
+ RD->setArgPassingRestrictions((RecordDecl::ArgPassingKind)Record.readInt());
return Redecl;
}
@@ -4114,8 +4114,9 @@ void ASTDeclReader::UpdateDecl(Decl *D,
bool HadRealDefinition =
OldDD && (OldDD->Definition != RD ||
!Reader.PendingFakeDefinitionData.count(OldDD));
- RD->setCanPassInRegisters(Record.readInt());
RD->setParamDestroyedInCallee(Record.readInt());
+ RD->setArgPassingRestrictions(
+ (RecordDecl::ArgPassingKind)Record.readInt());
ReadCXXRecordDefinition(RD, /*Update*/true);
// Visible update is handled separately.
Modified: cfe/trunk/lib/Serialization/ASTWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriter.cpp?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTWriter.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTWriter.cpp Mon Apr 9 13:39:47 2018
@@ -5193,8 +5193,8 @@ void ASTWriter::WriteDeclUpdatesBlocks(R
case UPD_CXX_INSTANTIATED_CLASS_DEFINITION: {
auto *RD = cast<CXXRecordDecl>(D);
UpdatedDeclContexts.insert(RD->getPrimaryContext());
- Record.push_back(RD->canPassInRegisters());
Record.push_back(RD->isParamDestroyedInCallee());
+ Record.push_back(RD->getArgPassingRestrictions());
Record.AddCXXDefinitionData(RD);
Record.AddOffset(WriteDeclContextLexicalBlock(
*Context, const_cast<CXXRecordDecl *>(RD)));
Modified: cfe/trunk/lib/Serialization/ASTWriterDecl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriterDecl.cpp?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTWriterDecl.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTWriterDecl.cpp Mon Apr 9 13:39:47 2018
@@ -469,8 +469,8 @@ void ASTDeclWriter::VisitRecordDecl(Reco
Record.push_back(D->isNonTrivialToPrimitiveDefaultInitialize());
Record.push_back(D->isNonTrivialToPrimitiveCopy());
Record.push_back(D->isNonTrivialToPrimitiveDestroy());
- Record.push_back(D->canPassInRegisters());
Record.push_back(D->isParamDestroyedInCallee());
+ Record.push_back(D->getArgPassingRestrictions());
if (D->getDeclContext() == D->getLexicalDeclContext() &&
!D->hasAttrs() &&
@@ -1913,9 +1913,10 @@ void ASTWriter::WriteDeclAbbrevs() {
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
// isNonTrivialToPrimitiveDestroy
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
- Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // canPassInRegisters
// isParamDestroyedInCallee
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
+ // getArgPassingRestrictions
+ Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 2));
// DC
Abv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LexicalOffset
Modified: cfe/trunk/test/CodeGenObjCXX/objc-struct-cxx-abi.mm
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjCXX/objc-struct-cxx-abi.mm?rev=329617&r1=329616&r2=329617&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenObjCXX/objc-struct-cxx-abi.mm (original)
+++ cfe/trunk/test/CodeGenObjCXX/objc-struct-cxx-abi.mm Mon Apr 9 13:39:47 2018
@@ -8,6 +8,8 @@
// pointer fields are passed directly.
// CHECK: %[[STRUCT_STRONGWEAK:.*]] = type { i8*, i8* }
+// CHECK: %[[STRUCT_CONTAINSSTRONGWEAK:.*]] = type { %[[STRUCT_STRONGWEAK]] }
+// CHECK: %[[STRUCT_DERIVEDSTRONGWEAK:.*]] = type { %[[STRUCT_STRONGWEAK]] }
// CHECK: %[[STRUCT_STRONG:.*]] = type { i8* }
// CHECK: %[[STRUCT_S:.*]] = type { i8* }
// CHECK: %[[STRUCT_CONTAINSNONTRIVIAL:.*]] = type { %{{.*}}, i8* }
@@ -22,6 +24,21 @@ struct StrongWeak {
};
#ifdef TRIVIALABI
+struct __attribute__((trivial_abi)) ContainsStrongWeak {
+#else
+struct ContainsStrongWeak {
+#endif
+ StrongWeak sw;
+};
+
+#ifdef TRIVIALABI
+struct __attribute__((trivial_abi)) DerivedStrongWeak : StrongWeak {
+#else
+struct DerivedStrongWeak : StrongWeak {
+#endif
+};
+
+#ifdef TRIVIALABI
struct __attribute__((trivial_abi)) Strong {
#else
struct Strong {
@@ -84,6 +101,18 @@ StrongWeak testReturnStrongWeak(StrongWe
return *a;
}
+// CHECK: define void @_Z27testParamContainsStrongWeak18ContainsStrongWeak(%[[STRUCT_CONTAINSSTRONGWEAK]]* %[[A:.*]])
+// CHECK: call %[[STRUCT_CONTAINSSTRONGWEAK]]* @_ZN18ContainsStrongWeakD1Ev(%[[STRUCT_CONTAINSSTRONGWEAK]]* %[[A]])
+
+void testParamContainsStrongWeak(ContainsStrongWeak a) {
+}
+
+// CHECK: define void @_Z26testParamDerivedStrongWeak17DerivedStrongWeak(%[[STRUCT_DERIVEDSTRONGWEAK]]* %[[A:.*]])
+// CHECK: call %[[STRUCT_DERIVEDSTRONGWEAK]]* @_ZN17DerivedStrongWeakD1Ev(%[[STRUCT_DERIVEDSTRONGWEAK]]* %[[A]])
+
+void testParamDerivedStrongWeak(DerivedStrongWeak a) {
+}
+
// CHECK: define void @_Z15testParamStrong6Strong(i64 %[[A_COERCE:.*]])
// CHECK: %[[A:.*]] = alloca %[[STRUCT_STRONG]], align 8
// CHECK: %[[COERCE_DIVE:.*]] = getelementptr inbounds %[[STRUCT_STRONG]], %[[STRUCT_STRONG]]* %[[A]], i32 0, i32 0
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