| //=== RecordLayoutBuilder.cpp - Helper class for building record layouts ---==// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/AST/RecordLayout.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Attr.h" |
| #include "clang/AST/CXXInheritance.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/DeclObjC.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/Sema/SemaDiagnostic.h" |
| #include "llvm/ADT/SmallSet.h" |
| #include "llvm/Support/CrashRecoveryContext.h" |
| #include "llvm/Support/Format.h" |
| #include "llvm/Support/MathExtras.h" |
| |
| using namespace clang; |
| |
| namespace { |
| |
| /// BaseSubobjectInfo - Represents a single base subobject in a complete class. |
| /// For a class hierarchy like |
| /// |
| /// class A { }; |
| /// class B : A { }; |
| /// class C : A, B { }; |
| /// |
| /// The BaseSubobjectInfo graph for C will have three BaseSubobjectInfo |
| /// instances, one for B and two for A. |
| /// |
| /// If a base is virtual, it will only have one BaseSubobjectInfo allocated. |
| struct BaseSubobjectInfo { |
| /// Class - The class for this base info. |
| const CXXRecordDecl *Class; |
| |
| /// IsVirtual - Whether the BaseInfo represents a virtual base or not. |
| bool IsVirtual; |
| |
| /// Bases - Information about the base subobjects. |
| SmallVector<BaseSubobjectInfo*, 4> Bases; |
| |
| /// PrimaryVirtualBaseInfo - Holds the base info for the primary virtual base |
| /// of this base info (if one exists). |
| BaseSubobjectInfo *PrimaryVirtualBaseInfo; |
| |
| // FIXME: Document. |
| const BaseSubobjectInfo *Derived; |
| }; |
| |
| /// EmptySubobjectMap - Keeps track of which empty subobjects exist at different |
| /// offsets while laying out a C++ class. |
| class EmptySubobjectMap { |
| const ASTContext &Context; |
| uint64_t CharWidth; |
| |
| /// Class - The class whose empty entries we're keeping track of. |
| const CXXRecordDecl *Class; |
| |
| /// EmptyClassOffsets - A map from offsets to empty record decls. |
| typedef SmallVector<const CXXRecordDecl *, 1> ClassVectorTy; |
| typedef llvm::DenseMap<CharUnits, ClassVectorTy> EmptyClassOffsetsMapTy; |
| EmptyClassOffsetsMapTy EmptyClassOffsets; |
| |
| /// MaxEmptyClassOffset - The highest offset known to contain an empty |
| /// base subobject. |
| CharUnits MaxEmptyClassOffset; |
| |
| /// ComputeEmptySubobjectSizes - Compute the size of the largest base or |
| /// member subobject that is empty. |
| void ComputeEmptySubobjectSizes(); |
| |
| void AddSubobjectAtOffset(const CXXRecordDecl *RD, CharUnits Offset); |
| |
| void UpdateEmptyBaseSubobjects(const BaseSubobjectInfo *Info, |
| CharUnits Offset, bool PlacingEmptyBase); |
| |
| void UpdateEmptyFieldSubobjects(const CXXRecordDecl *RD, |
| const CXXRecordDecl *Class, |
| CharUnits Offset); |
| void UpdateEmptyFieldSubobjects(const FieldDecl *FD, CharUnits Offset); |
| |
| /// AnyEmptySubobjectsBeyondOffset - Returns whether there are any empty |
| /// subobjects beyond the given offset. |
| bool AnyEmptySubobjectsBeyondOffset(CharUnits Offset) const { |
| return Offset <= MaxEmptyClassOffset; |
| } |
| |
| CharUnits |
| getFieldOffset(const ASTRecordLayout &Layout, unsigned FieldNo) const { |
| uint64_t FieldOffset = Layout.getFieldOffset(FieldNo); |
| assert(FieldOffset % CharWidth == 0 && |
| "Field offset not at char boundary!"); |
| |
| return Context.toCharUnitsFromBits(FieldOffset); |
| } |
| |
| protected: |
| bool CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD, |
| CharUnits Offset) const; |
| |
| bool CanPlaceBaseSubobjectAtOffset(const BaseSubobjectInfo *Info, |
| CharUnits Offset); |
| |
| bool CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD, |
| const CXXRecordDecl *Class, |
| CharUnits Offset) const; |
| bool CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD, |
| CharUnits Offset) const; |
| |
| public: |
| /// This holds the size of the largest empty subobject (either a base |
| /// or a member). Will be zero if the record being built doesn't contain |
| /// any empty classes. |
| CharUnits SizeOfLargestEmptySubobject; |
| |
| EmptySubobjectMap(const ASTContext &Context, const CXXRecordDecl *Class) |
| : Context(Context), CharWidth(Context.getCharWidth()), Class(Class) { |
| ComputeEmptySubobjectSizes(); |
| } |
| |
| /// CanPlaceBaseAtOffset - Return whether the given base class can be placed |
| /// at the given offset. |
| /// Returns false if placing the record will result in two components |
| /// (direct or indirect) of the same type having the same offset. |
| bool CanPlaceBaseAtOffset(const BaseSubobjectInfo *Info, |
| CharUnits Offset); |
| |
| /// CanPlaceFieldAtOffset - Return whether a field can be placed at the given |
| /// offset. |
| bool CanPlaceFieldAtOffset(const FieldDecl *FD, CharUnits Offset); |
| }; |
| |
| void EmptySubobjectMap::ComputeEmptySubobjectSizes() { |
| // Check the bases. |
| for (CXXRecordDecl::base_class_const_iterator I = Class->bases_begin(), |
| E = Class->bases_end(); I != E; ++I) { |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| CharUnits EmptySize; |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(BaseDecl); |
| if (BaseDecl->isEmpty()) { |
| // If the class decl is empty, get its size. |
| EmptySize = Layout.getSize(); |
| } else { |
| // Otherwise, we get the largest empty subobject for the decl. |
| EmptySize = Layout.getSizeOfLargestEmptySubobject(); |
| } |
| |
| if (EmptySize > SizeOfLargestEmptySubobject) |
| SizeOfLargestEmptySubobject = EmptySize; |
| } |
| |
| // Check the fields. |
| for (CXXRecordDecl::field_iterator I = Class->field_begin(), |
| E = Class->field_end(); I != E; ++I) { |
| |
| const RecordType *RT = |
| Context.getBaseElementType(I->getType())->getAs<RecordType>(); |
| |
| // We only care about record types. |
| if (!RT) |
| continue; |
| |
| CharUnits EmptySize; |
| const CXXRecordDecl *MemberDecl = cast<CXXRecordDecl>(RT->getDecl()); |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(MemberDecl); |
| if (MemberDecl->isEmpty()) { |
| // If the class decl is empty, get its size. |
| EmptySize = Layout.getSize(); |
| } else { |
| // Otherwise, we get the largest empty subobject for the decl. |
| EmptySize = Layout.getSizeOfLargestEmptySubobject(); |
| } |
| |
| if (EmptySize > SizeOfLargestEmptySubobject) |
| SizeOfLargestEmptySubobject = EmptySize; |
| } |
| } |
| |
| bool |
| EmptySubobjectMap::CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD, |
| CharUnits Offset) const { |
| // We only need to check empty bases. |
| if (!RD->isEmpty()) |
| return true; |
| |
| EmptyClassOffsetsMapTy::const_iterator I = EmptyClassOffsets.find(Offset); |
| if (I == EmptyClassOffsets.end()) |
| return true; |
| |
| const ClassVectorTy& Classes = I->second; |
| if (std::find(Classes.begin(), Classes.end(), RD) == Classes.end()) |
| return true; |
| |
| // There is already an empty class of the same type at this offset. |
| return false; |
| } |
| |
| void EmptySubobjectMap::AddSubobjectAtOffset(const CXXRecordDecl *RD, |
| CharUnits Offset) { |
| // We only care about empty bases. |
| if (!RD->isEmpty()) |
| return; |
| |
| // If we have empty structures inside a union, we can assign both |
| // the same offset. Just avoid pushing them twice in the list. |
| ClassVectorTy& Classes = EmptyClassOffsets[Offset]; |
| if (std::find(Classes.begin(), Classes.end(), RD) != Classes.end()) |
| return; |
| |
| Classes.push_back(RD); |
| |
| // Update the empty class offset. |
| if (Offset > MaxEmptyClassOffset) |
| MaxEmptyClassOffset = Offset; |
| } |
| |
| bool |
| EmptySubobjectMap::CanPlaceBaseSubobjectAtOffset(const BaseSubobjectInfo *Info, |
| CharUnits Offset) { |
| // We don't have to keep looking past the maximum offset that's known to |
| // contain an empty class. |
| if (!AnyEmptySubobjectsBeyondOffset(Offset)) |
| return true; |
| |
| if (!CanPlaceSubobjectAtOffset(Info->Class, Offset)) |
| return false; |
| |
| // Traverse all non-virtual bases. |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(Info->Class); |
| for (unsigned I = 0, E = Info->Bases.size(); I != E; ++I) { |
| BaseSubobjectInfo* Base = Info->Bases[I]; |
| if (Base->IsVirtual) |
| continue; |
| |
| CharUnits BaseOffset = Offset + Layout.getBaseClassOffset(Base->Class); |
| |
| if (!CanPlaceBaseSubobjectAtOffset(Base, BaseOffset)) |
| return false; |
| } |
| |
| if (Info->PrimaryVirtualBaseInfo) { |
| BaseSubobjectInfo *PrimaryVirtualBaseInfo = Info->PrimaryVirtualBaseInfo; |
| |
| if (Info == PrimaryVirtualBaseInfo->Derived) { |
| if (!CanPlaceBaseSubobjectAtOffset(PrimaryVirtualBaseInfo, Offset)) |
| return false; |
| } |
| } |
| |
| // Traverse all member variables. |
| unsigned FieldNo = 0; |
| for (CXXRecordDecl::field_iterator I = Info->Class->field_begin(), |
| E = Info->Class->field_end(); I != E; ++I, ++FieldNo) { |
| if (I->isBitField()) |
| continue; |
| |
| CharUnits FieldOffset = Offset + getFieldOffset(Layout, FieldNo); |
| if (!CanPlaceFieldSubobjectAtOffset(*I, FieldOffset)) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| void EmptySubobjectMap::UpdateEmptyBaseSubobjects(const BaseSubobjectInfo *Info, |
| CharUnits Offset, |
| bool PlacingEmptyBase) { |
| if (!PlacingEmptyBase && Offset >= SizeOfLargestEmptySubobject) { |
| // We know that the only empty subobjects that can conflict with empty |
| // subobject of non-empty bases, are empty bases that can be placed at |
| // offset zero. Because of this, we only need to keep track of empty base |
| // subobjects with offsets less than the size of the largest empty |
| // subobject for our class. |
| return; |
| } |
| |
| AddSubobjectAtOffset(Info->Class, Offset); |
| |
| // Traverse all non-virtual bases. |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(Info->Class); |
| for (unsigned I = 0, E = Info->Bases.size(); I != E; ++I) { |
| BaseSubobjectInfo* Base = Info->Bases[I]; |
| if (Base->IsVirtual) |
| continue; |
| |
| CharUnits BaseOffset = Offset + Layout.getBaseClassOffset(Base->Class); |
| UpdateEmptyBaseSubobjects(Base, BaseOffset, PlacingEmptyBase); |
| } |
| |
| if (Info->PrimaryVirtualBaseInfo) { |
| BaseSubobjectInfo *PrimaryVirtualBaseInfo = Info->PrimaryVirtualBaseInfo; |
| |
| if (Info == PrimaryVirtualBaseInfo->Derived) |
| UpdateEmptyBaseSubobjects(PrimaryVirtualBaseInfo, Offset, |
| PlacingEmptyBase); |
| } |
| |
| // Traverse all member variables. |
| unsigned FieldNo = 0; |
| for (CXXRecordDecl::field_iterator I = Info->Class->field_begin(), |
| E = Info->Class->field_end(); I != E; ++I, ++FieldNo) { |
| if (I->isBitField()) |
| continue; |
| |
| CharUnits FieldOffset = Offset + getFieldOffset(Layout, FieldNo); |
| UpdateEmptyFieldSubobjects(*I, FieldOffset); |
| } |
| } |
| |
| bool EmptySubobjectMap::CanPlaceBaseAtOffset(const BaseSubobjectInfo *Info, |
| CharUnits Offset) { |
| // If we know this class doesn't have any empty subobjects we don't need to |
| // bother checking. |
| if (SizeOfLargestEmptySubobject.isZero()) |
| return true; |
| |
| if (!CanPlaceBaseSubobjectAtOffset(Info, Offset)) |
| return false; |
| |
| // We are able to place the base at this offset. Make sure to update the |
| // empty base subobject map. |
| UpdateEmptyBaseSubobjects(Info, Offset, Info->Class->isEmpty()); |
| return true; |
| } |
| |
| bool |
| EmptySubobjectMap::CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD, |
| const CXXRecordDecl *Class, |
| CharUnits Offset) const { |
| // We don't have to keep looking past the maximum offset that's known to |
| // contain an empty class. |
| if (!AnyEmptySubobjectsBeyondOffset(Offset)) |
| return true; |
| |
| if (!CanPlaceSubobjectAtOffset(RD, Offset)) |
| return false; |
| |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); |
| |
| // Traverse all non-virtual bases. |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| if (I->isVirtual()) |
| continue; |
| |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| CharUnits BaseOffset = Offset + Layout.getBaseClassOffset(BaseDecl); |
| if (!CanPlaceFieldSubobjectAtOffset(BaseDecl, Class, BaseOffset)) |
| return false; |
| } |
| |
| if (RD == Class) { |
| // This is the most derived class, traverse virtual bases as well. |
| for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(), |
| E = RD->vbases_end(); I != E; ++I) { |
| const CXXRecordDecl *VBaseDecl = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| CharUnits VBaseOffset = Offset + Layout.getVBaseClassOffset(VBaseDecl); |
| if (!CanPlaceFieldSubobjectAtOffset(VBaseDecl, Class, VBaseOffset)) |
| return false; |
| } |
| } |
| |
| // Traverse all member variables. |
| unsigned FieldNo = 0; |
| for (CXXRecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end(); |
| I != E; ++I, ++FieldNo) { |
| if (I->isBitField()) |
| continue; |
| |
| CharUnits FieldOffset = Offset + getFieldOffset(Layout, FieldNo); |
| |
| if (!CanPlaceFieldSubobjectAtOffset(*I, FieldOffset)) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| bool |
| EmptySubobjectMap::CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD, |
| CharUnits Offset) const { |
| // We don't have to keep looking past the maximum offset that's known to |
| // contain an empty class. |
| if (!AnyEmptySubobjectsBeyondOffset(Offset)) |
| return true; |
| |
| QualType T = FD->getType(); |
| if (const RecordType *RT = T->getAs<RecordType>()) { |
| const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); |
| return CanPlaceFieldSubobjectAtOffset(RD, RD, Offset); |
| } |
| |
| // If we have an array type we need to look at every element. |
| if (const ConstantArrayType *AT = Context.getAsConstantArrayType(T)) { |
| QualType ElemTy = Context.getBaseElementType(AT); |
| const RecordType *RT = ElemTy->getAs<RecordType>(); |
| if (!RT) |
| return true; |
| |
| const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); |
| |
| uint64_t NumElements = Context.getConstantArrayElementCount(AT); |
| CharUnits ElementOffset = Offset; |
| for (uint64_t I = 0; I != NumElements; ++I) { |
| // We don't have to keep looking past the maximum offset that's known to |
| // contain an empty class. |
| if (!AnyEmptySubobjectsBeyondOffset(ElementOffset)) |
| return true; |
| |
| if (!CanPlaceFieldSubobjectAtOffset(RD, RD, ElementOffset)) |
| return false; |
| |
| ElementOffset += Layout.getSize(); |
| } |
| } |
| |
| return true; |
| } |
| |
| bool |
| EmptySubobjectMap::CanPlaceFieldAtOffset(const FieldDecl *FD, |
| CharUnits Offset) { |
| if (!CanPlaceFieldSubobjectAtOffset(FD, Offset)) |
| return false; |
| |
| // We are able to place the member variable at this offset. |
| // Make sure to update the empty base subobject map. |
| UpdateEmptyFieldSubobjects(FD, Offset); |
| return true; |
| } |
| |
| void EmptySubobjectMap::UpdateEmptyFieldSubobjects(const CXXRecordDecl *RD, |
| const CXXRecordDecl *Class, |
| CharUnits Offset) { |
| // We know that the only empty subobjects that can conflict with empty |
| // field subobjects are subobjects of empty bases that can be placed at offset |
| // zero. Because of this, we only need to keep track of empty field |
| // subobjects with offsets less than the size of the largest empty |
| // subobject for our class. |
| if (Offset >= SizeOfLargestEmptySubobject) |
| return; |
| |
| AddSubobjectAtOffset(RD, Offset); |
| |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); |
| |
| // Traverse all non-virtual bases. |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| if (I->isVirtual()) |
| continue; |
| |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| CharUnits BaseOffset = Offset + Layout.getBaseClassOffset(BaseDecl); |
| UpdateEmptyFieldSubobjects(BaseDecl, Class, BaseOffset); |
| } |
| |
| if (RD == Class) { |
| // This is the most derived class, traverse virtual bases as well. |
| for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(), |
| E = RD->vbases_end(); I != E; ++I) { |
| const CXXRecordDecl *VBaseDecl = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| CharUnits VBaseOffset = Offset + Layout.getVBaseClassOffset(VBaseDecl); |
| UpdateEmptyFieldSubobjects(VBaseDecl, Class, VBaseOffset); |
| } |
| } |
| |
| // Traverse all member variables. |
| unsigned FieldNo = 0; |
| for (CXXRecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end(); |
| I != E; ++I, ++FieldNo) { |
| if (I->isBitField()) |
| continue; |
| |
| CharUnits FieldOffset = Offset + getFieldOffset(Layout, FieldNo); |
| |
| UpdateEmptyFieldSubobjects(*I, FieldOffset); |
| } |
| } |
| |
| void EmptySubobjectMap::UpdateEmptyFieldSubobjects(const FieldDecl *FD, |
| CharUnits Offset) { |
| QualType T = FD->getType(); |
| if (const RecordType *RT = T->getAs<RecordType>()) { |
| const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); |
| UpdateEmptyFieldSubobjects(RD, RD, Offset); |
| return; |
| } |
| |
| // If we have an array type we need to update every element. |
| if (const ConstantArrayType *AT = Context.getAsConstantArrayType(T)) { |
| QualType ElemTy = Context.getBaseElementType(AT); |
| const RecordType *RT = ElemTy->getAs<RecordType>(); |
| if (!RT) |
| return; |
| |
| const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); |
| |
| uint64_t NumElements = Context.getConstantArrayElementCount(AT); |
| CharUnits ElementOffset = Offset; |
| |
| for (uint64_t I = 0; I != NumElements; ++I) { |
| // We know that the only empty subobjects that can conflict with empty |
| // field subobjects are subobjects of empty bases that can be placed at |
| // offset zero. Because of this, we only need to keep track of empty field |
| // subobjects with offsets less than the size of the largest empty |
| // subobject for our class. |
| if (ElementOffset >= SizeOfLargestEmptySubobject) |
| return; |
| |
| UpdateEmptyFieldSubobjects(RD, RD, ElementOffset); |
| ElementOffset += Layout.getSize(); |
| } |
| } |
| } |
| |
| typedef llvm::SmallPtrSet<const CXXRecordDecl*, 4> ClassSetTy; |
| |
| class RecordLayoutBuilder { |
| protected: |
| // FIXME: Remove this and make the appropriate fields public. |
| friend class clang::ASTContext; |
| |
| const ASTContext &Context; |
| |
| EmptySubobjectMap *EmptySubobjects; |
| |
| /// Size - The current size of the record layout. |
| uint64_t Size; |
| |
| /// Alignment - The current alignment of the record layout. |
| CharUnits Alignment; |
| |
| /// \brief The alignment if attribute packed is not used. |
| CharUnits UnpackedAlignment; |
| |
| SmallVector<uint64_t, 16> FieldOffsets; |
| |
| /// \brief Whether the external AST source has provided a layout for this |
| /// record. |
| unsigned ExternalLayout : 1; |
| |
| /// \brief Whether we need to infer alignment, even when we have an |
| /// externally-provided layout. |
| unsigned InferAlignment : 1; |
| |
| /// Packed - Whether the record is packed or not. |
| unsigned Packed : 1; |
| |
| unsigned IsUnion : 1; |
| |
| unsigned IsMac68kAlign : 1; |
| |
| unsigned IsMsStruct : 1; |
| |
| /// UnfilledBitsInLastUnit - If the last field laid out was a bitfield, |
| /// this contains the number of bits in the last unit that can be used for |
| /// an adjacent bitfield if necessary. The unit in question is usually |
| /// a byte, but larger units are used if IsMsStruct. |
| unsigned char UnfilledBitsInLastUnit; |
| /// LastBitfieldTypeSize - If IsMsStruct, represents the size of the type |
| /// of the previous field if it was a bitfield. |
| unsigned char LastBitfieldTypeSize; |
| |
| /// MaxFieldAlignment - The maximum allowed field alignment. This is set by |
| /// #pragma pack. |
| CharUnits MaxFieldAlignment; |
| |
| /// DataSize - The data size of the record being laid out. |
| uint64_t DataSize; |
| |
| CharUnits NonVirtualSize; |
| CharUnits NonVirtualAlignment; |
| |
| /// PrimaryBase - the primary base class (if one exists) of the class |
| /// we're laying out. |
| const CXXRecordDecl *PrimaryBase; |
| |
| /// PrimaryBaseIsVirtual - Whether the primary base of the class we're laying |
| /// out is virtual. |
| bool PrimaryBaseIsVirtual; |
| |
| /// HasOwnVFPtr - Whether the class provides its own vtable/vftbl |
| /// pointer, as opposed to inheriting one from a primary base class. |
| bool HasOwnVFPtr; |
| |
| typedef llvm::DenseMap<const CXXRecordDecl *, CharUnits> BaseOffsetsMapTy; |
| |
| /// Bases - base classes and their offsets in the record. |
| BaseOffsetsMapTy Bases; |
| |
| // VBases - virtual base classes and their offsets in the record. |
| ASTRecordLayout::VBaseOffsetsMapTy VBases; |
| |
| /// IndirectPrimaryBases - Virtual base classes, direct or indirect, that are |
| /// primary base classes for some other direct or indirect base class. |
| CXXIndirectPrimaryBaseSet IndirectPrimaryBases; |
| |
| /// FirstNearlyEmptyVBase - The first nearly empty virtual base class in |
| /// inheritance graph order. Used for determining the primary base class. |
| const CXXRecordDecl *FirstNearlyEmptyVBase; |
| |
| /// VisitedVirtualBases - A set of all the visited virtual bases, used to |
| /// avoid visiting virtual bases more than once. |
| llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBases; |
| |
| /// \brief Externally-provided size. |
| uint64_t ExternalSize; |
| |
| /// \brief Externally-provided alignment. |
| uint64_t ExternalAlign; |
| |
| /// \brief Externally-provided field offsets. |
| llvm::DenseMap<const FieldDecl *, uint64_t> ExternalFieldOffsets; |
| |
| /// \brief Externally-provided direct, non-virtual base offsets. |
| llvm::DenseMap<const CXXRecordDecl *, CharUnits> ExternalBaseOffsets; |
| |
| /// \brief Externally-provided virtual base offsets. |
| llvm::DenseMap<const CXXRecordDecl *, CharUnits> ExternalVirtualBaseOffsets; |
| |
| RecordLayoutBuilder(const ASTContext &Context, |
| EmptySubobjectMap *EmptySubobjects) |
| : Context(Context), EmptySubobjects(EmptySubobjects), Size(0), |
| Alignment(CharUnits::One()), UnpackedAlignment(CharUnits::One()), |
| ExternalLayout(false), InferAlignment(false), |
| Packed(false), IsUnion(false), IsMac68kAlign(false), IsMsStruct(false), |
| UnfilledBitsInLastUnit(0), LastBitfieldTypeSize(0), |
| MaxFieldAlignment(CharUnits::Zero()), |
| DataSize(0), NonVirtualSize(CharUnits::Zero()), |
| NonVirtualAlignment(CharUnits::One()), |
| PrimaryBase(0), PrimaryBaseIsVirtual(false), |
| HasOwnVFPtr(false), |
| FirstNearlyEmptyVBase(0) { } |
| |
| /// Reset this RecordLayoutBuilder to a fresh state, using the given |
| /// alignment as the initial alignment. This is used for the |
| /// correct layout of vb-table pointers in MSVC. |
| void resetWithTargetAlignment(CharUnits TargetAlignment) { |
| const ASTContext &Context = this->Context; |
| EmptySubobjectMap *EmptySubobjects = this->EmptySubobjects; |
| this->~RecordLayoutBuilder(); |
| new (this) RecordLayoutBuilder(Context, EmptySubobjects); |
| Alignment = UnpackedAlignment = TargetAlignment; |
| } |
| |
| void Layout(const RecordDecl *D); |
| void Layout(const CXXRecordDecl *D); |
| void Layout(const ObjCInterfaceDecl *D); |
| |
| void LayoutFields(const RecordDecl *D); |
| void LayoutField(const FieldDecl *D); |
| void LayoutWideBitField(uint64_t FieldSize, uint64_t TypeSize, |
| bool FieldPacked, const FieldDecl *D); |
| void LayoutBitField(const FieldDecl *D); |
| |
| TargetCXXABI getCXXABI() const { |
| return Context.getTargetInfo().getCXXABI(); |
| } |
| |
| /// BaseSubobjectInfoAllocator - Allocator for BaseSubobjectInfo objects. |
| llvm::SpecificBumpPtrAllocator<BaseSubobjectInfo> BaseSubobjectInfoAllocator; |
| |
| typedef llvm::DenseMap<const CXXRecordDecl *, BaseSubobjectInfo *> |
| BaseSubobjectInfoMapTy; |
| |
| /// VirtualBaseInfo - Map from all the (direct or indirect) virtual bases |
| /// of the class we're laying out to their base subobject info. |
| BaseSubobjectInfoMapTy VirtualBaseInfo; |
| |
| /// NonVirtualBaseInfo - Map from all the direct non-virtual bases of the |
| /// class we're laying out to their base subobject info. |
| BaseSubobjectInfoMapTy NonVirtualBaseInfo; |
| |
| /// ComputeBaseSubobjectInfo - Compute the base subobject information for the |
| /// bases of the given class. |
| void ComputeBaseSubobjectInfo(const CXXRecordDecl *RD); |
| |
| /// ComputeBaseSubobjectInfo - Compute the base subobject information for a |
| /// single class and all of its base classes. |
| BaseSubobjectInfo *ComputeBaseSubobjectInfo(const CXXRecordDecl *RD, |
| bool IsVirtual, |
| BaseSubobjectInfo *Derived); |
| |
| /// DeterminePrimaryBase - Determine the primary base of the given class. |
| void DeterminePrimaryBase(const CXXRecordDecl *RD); |
| |
| void SelectPrimaryVBase(const CXXRecordDecl *RD); |
| |
| void EnsureVTablePointerAlignment(CharUnits UnpackedBaseAlign); |
| |
| /// LayoutNonVirtualBases - Determines the primary base class (if any) and |
| /// lays it out. Will then proceed to lay out all non-virtual base clasess. |
| void LayoutNonVirtualBases(const CXXRecordDecl *RD); |
| |
| /// LayoutNonVirtualBase - Lays out a single non-virtual base. |
| void LayoutNonVirtualBase(const BaseSubobjectInfo *Base); |
| |
| void AddPrimaryVirtualBaseOffsets(const BaseSubobjectInfo *Info, |
| CharUnits Offset); |
| |
| /// LayoutVirtualBases - Lays out all the virtual bases. |
| void LayoutVirtualBases(const CXXRecordDecl *RD, |
| const CXXRecordDecl *MostDerivedClass); |
| |
| /// LayoutVirtualBase - Lays out a single virtual base. |
| void LayoutVirtualBase(const BaseSubobjectInfo *Base); |
| |
| /// LayoutBase - Will lay out a base and return the offset where it was |
| /// placed, in chars. |
| CharUnits LayoutBase(const BaseSubobjectInfo *Base); |
| |
| /// InitializeLayout - Initialize record layout for the given record decl. |
| void InitializeLayout(const Decl *D); |
| |
| /// FinishLayout - Finalize record layout. Adjust record size based on the |
| /// alignment. |
| void FinishLayout(const NamedDecl *D); |
| |
| void UpdateAlignment(CharUnits NewAlignment, CharUnits UnpackedNewAlignment); |
| void UpdateAlignment(CharUnits NewAlignment) { |
| UpdateAlignment(NewAlignment, NewAlignment); |
| } |
| |
| /// \brief Retrieve the externally-supplied field offset for the given |
| /// field. |
| /// |
| /// \param Field The field whose offset is being queried. |
| /// \param ComputedOffset The offset that we've computed for this field. |
| uint64_t updateExternalFieldOffset(const FieldDecl *Field, |
| uint64_t ComputedOffset); |
| |
| void CheckFieldPadding(uint64_t Offset, uint64_t UnpaddedOffset, |
| uint64_t UnpackedOffset, unsigned UnpackedAlign, |
| bool isPacked, const FieldDecl *D); |
| |
| DiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID); |
| |
| CharUnits getSize() const { |
| assert(Size % Context.getCharWidth() == 0); |
| return Context.toCharUnitsFromBits(Size); |
| } |
| uint64_t getSizeInBits() const { return Size; } |
| |
| void setSize(CharUnits NewSize) { Size = Context.toBits(NewSize); } |
| void setSize(uint64_t NewSize) { Size = NewSize; } |
| |
| CharUnits getAligment() const { return Alignment; } |
| |
| CharUnits getDataSize() const { |
| assert(DataSize % Context.getCharWidth() == 0); |
| return Context.toCharUnitsFromBits(DataSize); |
| } |
| uint64_t getDataSizeInBits() const { return DataSize; } |
| |
| void setDataSize(CharUnits NewSize) { DataSize = Context.toBits(NewSize); } |
| void setDataSize(uint64_t NewSize) { DataSize = NewSize; } |
| |
| RecordLayoutBuilder(const RecordLayoutBuilder &) LLVM_DELETED_FUNCTION; |
| void operator=(const RecordLayoutBuilder &) LLVM_DELETED_FUNCTION; |
| }; |
| } // end anonymous namespace |
| |
| void |
| RecordLayoutBuilder::SelectPrimaryVBase(const CXXRecordDecl *RD) { |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| assert(!I->getType()->isDependentType() && |
| "Cannot layout class with dependent bases."); |
| |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| // Check if this is a nearly empty virtual base. |
| if (I->isVirtual() && Context.isNearlyEmpty(Base)) { |
| // If it's not an indirect primary base, then we've found our primary |
| // base. |
| if (!IndirectPrimaryBases.count(Base)) { |
| PrimaryBase = Base; |
| PrimaryBaseIsVirtual = true; |
| return; |
| } |
| |
| // Is this the first nearly empty virtual base? |
| if (!FirstNearlyEmptyVBase) |
| FirstNearlyEmptyVBase = Base; |
| } |
| |
| SelectPrimaryVBase(Base); |
| if (PrimaryBase) |
| return; |
| } |
| } |
| |
| /// DeterminePrimaryBase - Determine the primary base of the given class. |
| void RecordLayoutBuilder::DeterminePrimaryBase(const CXXRecordDecl *RD) { |
| // If the class isn't dynamic, it won't have a primary base. |
| if (!RD->isDynamicClass()) |
| return; |
| |
| // Compute all the primary virtual bases for all of our direct and |
| // indirect bases, and record all their primary virtual base classes. |
| RD->getIndirectPrimaryBases(IndirectPrimaryBases); |
| |
| // If the record has a dynamic base class, attempt to choose a primary base |
| // class. It is the first (in direct base class order) non-virtual dynamic |
| // base class, if one exists. |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); i != e; ++i) { |
| // Ignore virtual bases. |
| if (i->isVirtual()) |
| continue; |
| |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| |
| if (Base->isDynamicClass()) { |
| // We found it. |
| PrimaryBase = Base; |
| PrimaryBaseIsVirtual = false; |
| return; |
| } |
| } |
| |
| // Under the Itanium ABI, if there is no non-virtual primary base class, |
| // try to compute the primary virtual base. The primary virtual base is |
| // the first nearly empty virtual base that is not an indirect primary |
| // virtual base class, if one exists. |
| if (RD->getNumVBases() != 0) { |
| SelectPrimaryVBase(RD); |
| if (PrimaryBase) |
| return; |
| } |
| |
| // Otherwise, it is the first indirect primary base class, if one exists. |
| if (FirstNearlyEmptyVBase) { |
| PrimaryBase = FirstNearlyEmptyVBase; |
| PrimaryBaseIsVirtual = true; |
| return; |
| } |
| |
| assert(!PrimaryBase && "Should not get here with a primary base!"); |
| } |
| |
| BaseSubobjectInfo * |
| RecordLayoutBuilder::ComputeBaseSubobjectInfo(const CXXRecordDecl *RD, |
| bool IsVirtual, |
| BaseSubobjectInfo *Derived) { |
| BaseSubobjectInfo *Info; |
| |
| if (IsVirtual) { |
| // Check if we already have info about this virtual base. |
| BaseSubobjectInfo *&InfoSlot = VirtualBaseInfo[RD]; |
| if (InfoSlot) { |
| assert(InfoSlot->Class == RD && "Wrong class for virtual base info!"); |
| return InfoSlot; |
| } |
| |
| // We don't, create it. |
| InfoSlot = new (BaseSubobjectInfoAllocator.Allocate()) BaseSubobjectInfo; |
| Info = InfoSlot; |
| } else { |
| Info = new (BaseSubobjectInfoAllocator.Allocate()) BaseSubobjectInfo; |
| } |
| |
| Info->Class = RD; |
| Info->IsVirtual = IsVirtual; |
| Info->Derived = 0; |
| Info->PrimaryVirtualBaseInfo = 0; |
| |
| const CXXRecordDecl *PrimaryVirtualBase = 0; |
| BaseSubobjectInfo *PrimaryVirtualBaseInfo = 0; |
| |
| // Check if this base has a primary virtual base. |
| if (RD->getNumVBases()) { |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); |
| if (Layout.isPrimaryBaseVirtual()) { |
| // This base does have a primary virtual base. |
| PrimaryVirtualBase = Layout.getPrimaryBase(); |
| assert(PrimaryVirtualBase && "Didn't have a primary virtual base!"); |
| |
| // Now check if we have base subobject info about this primary base. |
| PrimaryVirtualBaseInfo = VirtualBaseInfo.lookup(PrimaryVirtualBase); |
| |
| if (PrimaryVirtualBaseInfo) { |
| if (PrimaryVirtualBaseInfo->Derived) { |
| // We did have info about this primary base, and it turns out that it |
| // has already been claimed as a primary virtual base for another |
| // base. |
| PrimaryVirtualBase = 0; |
| } else { |
| // We can claim this base as our primary base. |
| Info->PrimaryVirtualBaseInfo = PrimaryVirtualBaseInfo; |
| PrimaryVirtualBaseInfo->Derived = Info; |
| } |
| } |
| } |
| } |
| |
| // Now go through all direct bases. |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| bool IsVirtual = I->isVirtual(); |
| |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| Info->Bases.push_back(ComputeBaseSubobjectInfo(BaseDecl, IsVirtual, Info)); |
| } |
| |
| if (PrimaryVirtualBase && !PrimaryVirtualBaseInfo) { |
| // Traversing the bases must have created the base info for our primary |
| // virtual base. |
| PrimaryVirtualBaseInfo = VirtualBaseInfo.lookup(PrimaryVirtualBase); |
| assert(PrimaryVirtualBaseInfo && |
| "Did not create a primary virtual base!"); |
| |
| // Claim the primary virtual base as our primary virtual base. |
| Info->PrimaryVirtualBaseInfo = PrimaryVirtualBaseInfo; |
| PrimaryVirtualBaseInfo->Derived = Info; |
| } |
| |
| return Info; |
| } |
| |
| void RecordLayoutBuilder::ComputeBaseSubobjectInfo(const CXXRecordDecl *RD) { |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| bool IsVirtual = I->isVirtual(); |
| |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| // Compute the base subobject info for this base. |
| BaseSubobjectInfo *Info = ComputeBaseSubobjectInfo(BaseDecl, IsVirtual, 0); |
| |
| if (IsVirtual) { |
| // ComputeBaseInfo has already added this base for us. |
| assert(VirtualBaseInfo.count(BaseDecl) && |
| "Did not add virtual base!"); |
| } else { |
| // Add the base info to the map of non-virtual bases. |
| assert(!NonVirtualBaseInfo.count(BaseDecl) && |
| "Non-virtual base already exists!"); |
| NonVirtualBaseInfo.insert(std::make_pair(BaseDecl, Info)); |
| } |
| } |
| } |
| |
| void |
| RecordLayoutBuilder::EnsureVTablePointerAlignment(CharUnits UnpackedBaseAlign) { |
| CharUnits BaseAlign = (Packed) ? CharUnits::One() : UnpackedBaseAlign; |
| |
| // The maximum field alignment overrides base align. |
| if (!MaxFieldAlignment.isZero()) { |
| BaseAlign = std::min(BaseAlign, MaxFieldAlignment); |
| UnpackedBaseAlign = std::min(UnpackedBaseAlign, MaxFieldAlignment); |
| } |
| |
| // Round up the current record size to pointer alignment. |
| setSize(getSize().RoundUpToAlignment(BaseAlign)); |
| setDataSize(getSize()); |
| |
| // Update the alignment. |
| UpdateAlignment(BaseAlign, UnpackedBaseAlign); |
| } |
| |
| void |
| RecordLayoutBuilder::LayoutNonVirtualBases(const CXXRecordDecl *RD) { |
| // Then, determine the primary base class. |
| DeterminePrimaryBase(RD); |
| |
| // Compute base subobject info. |
| ComputeBaseSubobjectInfo(RD); |
| |
| // If we have a primary base class, lay it out. |
| if (PrimaryBase) { |
| if (PrimaryBaseIsVirtual) { |
| // If the primary virtual base was a primary virtual base of some other |
| // base class we'll have to steal it. |
| BaseSubobjectInfo *PrimaryBaseInfo = VirtualBaseInfo.lookup(PrimaryBase); |
| PrimaryBaseInfo->Derived = 0; |
| |
| // We have a virtual primary base, insert it as an indirect primary base. |
| IndirectPrimaryBases.insert(PrimaryBase); |
| |
| assert(!VisitedVirtualBases.count(PrimaryBase) && |
| "vbase already visited!"); |
| VisitedVirtualBases.insert(PrimaryBase); |
| |
| LayoutVirtualBase(PrimaryBaseInfo); |
| } else { |
| BaseSubobjectInfo *PrimaryBaseInfo = |
| NonVirtualBaseInfo.lookup(PrimaryBase); |
| assert(PrimaryBaseInfo && |
| "Did not find base info for non-virtual primary base!"); |
| |
| LayoutNonVirtualBase(PrimaryBaseInfo); |
| } |
| |
| // If this class needs a vtable/vf-table and didn't get one from a |
| // primary base, add it in now. |
| } else if (RD->isDynamicClass()) { |
| assert(DataSize == 0 && "Vtable pointer must be at offset zero!"); |
| CharUnits PtrWidth = |
| Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0)); |
| CharUnits PtrAlign = |
| Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerAlign(0)); |
| EnsureVTablePointerAlignment(PtrAlign); |
| HasOwnVFPtr = true; |
| setSize(getSize() + PtrWidth); |
| setDataSize(getSize()); |
| } |
| |
| bool HasDirectVirtualBases = false; |
| bool HasNonVirtualBaseWithVBTable = false; |
| |
| // Now lay out the non-virtual bases. |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| |
| // Ignore virtual bases, but remember that we saw one. |
| if (I->isVirtual()) { |
| HasDirectVirtualBases = true; |
| continue; |
| } |
| |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(I->getType()->castAs<RecordType>()->getDecl()); |
| |
| // Remember if this base has virtual bases itself. |
| if (BaseDecl->getNumVBases()) |
| HasNonVirtualBaseWithVBTable = true; |
| |
| // Skip the primary base, because we've already laid it out. The |
| // !PrimaryBaseIsVirtual check is required because we might have a |
| // non-virtual base of the same type as a primary virtual base. |
| if (BaseDecl == PrimaryBase && !PrimaryBaseIsVirtual) |
| continue; |
| |
| // Lay out the base. |
| BaseSubobjectInfo *BaseInfo = NonVirtualBaseInfo.lookup(BaseDecl); |
| assert(BaseInfo && "Did not find base info for non-virtual base!"); |
| |
| LayoutNonVirtualBase(BaseInfo); |
| } |
| } |
| |
| void RecordLayoutBuilder::LayoutNonVirtualBase(const BaseSubobjectInfo *Base) { |
| // Layout the base. |
| CharUnits Offset = LayoutBase(Base); |
| |
| // Add its base class offset. |
| assert(!Bases.count(Base->Class) && "base offset already exists!"); |
| Bases.insert(std::make_pair(Base->Class, Offset)); |
| |
| AddPrimaryVirtualBaseOffsets(Base, Offset); |
| } |
| |
| void |
| RecordLayoutBuilder::AddPrimaryVirtualBaseOffsets(const BaseSubobjectInfo *Info, |
| CharUnits Offset) { |
| // This base isn't interesting, it has no virtual bases. |
| if (!Info->Class->getNumVBases()) |
| return; |
| |
| // First, check if we have a virtual primary base to add offsets for. |
| if (Info->PrimaryVirtualBaseInfo) { |
| assert(Info->PrimaryVirtualBaseInfo->IsVirtual && |
| "Primary virtual base is not virtual!"); |
| if (Info->PrimaryVirtualBaseInfo->Derived == Info) { |
| // Add the offset. |
| assert(!VBases.count(Info->PrimaryVirtualBaseInfo->Class) && |
| "primary vbase offset already exists!"); |
| VBases.insert(std::make_pair(Info->PrimaryVirtualBaseInfo->Class, |
| ASTRecordLayout::VBaseInfo(Offset, false))); |
| |
| // Traverse the primary virtual base. |
| AddPrimaryVirtualBaseOffsets(Info->PrimaryVirtualBaseInfo, Offset); |
| } |
| } |
| |
| // Now go through all direct non-virtual bases. |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(Info->Class); |
| for (unsigned I = 0, E = Info->Bases.size(); I != E; ++I) { |
| const BaseSubobjectInfo *Base = Info->Bases[I]; |
| if (Base->IsVirtual) |
| continue; |
| |
| CharUnits BaseOffset = Offset + Layout.getBaseClassOffset(Base->Class); |
| AddPrimaryVirtualBaseOffsets(Base, BaseOffset); |
| } |
| } |
| |
| void |
| RecordLayoutBuilder::LayoutVirtualBases(const CXXRecordDecl *RD, |
| const CXXRecordDecl *MostDerivedClass) { |
| const CXXRecordDecl *PrimaryBase; |
| bool PrimaryBaseIsVirtual; |
| |
| if (MostDerivedClass == RD) { |
| PrimaryBase = this->PrimaryBase; |
| PrimaryBaseIsVirtual = this->PrimaryBaseIsVirtual; |
| } else { |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); |
| PrimaryBase = Layout.getPrimaryBase(); |
| PrimaryBaseIsVirtual = Layout.isPrimaryBaseVirtual(); |
| } |
| |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| assert(!I->getType()->isDependentType() && |
| "Cannot layout class with dependent bases."); |
| |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(I->getType()->castAs<RecordType>()->getDecl()); |
| |
| if (I->isVirtual()) { |
| if (PrimaryBase != BaseDecl || !PrimaryBaseIsVirtual) { |
| bool IndirectPrimaryBase = IndirectPrimaryBases.count(BaseDecl); |
| |
| // Only lay out the virtual base if it's not an indirect primary base. |
| if (!IndirectPrimaryBase) { |
| // Only visit virtual bases once. |
| if (!VisitedVirtualBases.insert(BaseDecl)) |
| continue; |
| |
| const BaseSubobjectInfo *BaseInfo = VirtualBaseInfo.lookup(BaseDecl); |
| assert(BaseInfo && "Did not find virtual base info!"); |
| LayoutVirtualBase(BaseInfo); |
| } |
| } |
| } |
| |
| if (!BaseDecl->getNumVBases()) { |
| // This base isn't interesting since it doesn't have any virtual bases. |
| continue; |
| } |
| |
| LayoutVirtualBases(BaseDecl, MostDerivedClass); |
| } |
| } |
| |
| void RecordLayoutBuilder::LayoutVirtualBase(const BaseSubobjectInfo *Base) { |
| assert(!Base->Derived && "Trying to lay out a primary virtual base!"); |
| |
| // Layout the base. |
| CharUnits Offset = LayoutBase(Base); |
| |
| // Add its base class offset. |
| assert(!VBases.count(Base->Class) && "vbase offset already exists!"); |
| VBases.insert(std::make_pair(Base->Class, |
| ASTRecordLayout::VBaseInfo(Offset, false))); |
| |
| AddPrimaryVirtualBaseOffsets(Base, Offset); |
| } |
| |
| CharUnits RecordLayoutBuilder::LayoutBase(const BaseSubobjectInfo *Base) { |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(Base->Class); |
| |
| |
| CharUnits Offset; |
| |
| // Query the external layout to see if it provides an offset. |
| bool HasExternalLayout = false; |
| if (ExternalLayout) { |
| llvm::DenseMap<const CXXRecordDecl *, CharUnits>::iterator Known; |
| if (Base->IsVirtual) { |
| Known = ExternalVirtualBaseOffsets.find(Base->Class); |
| if (Known != ExternalVirtualBaseOffsets.end()) { |
| Offset = Known->second; |
| HasExternalLayout = true; |
| } |
| } else { |
| Known = ExternalBaseOffsets.find(Base->Class); |
| if (Known != ExternalBaseOffsets.end()) { |
| Offset = Known->second; |
| HasExternalLayout = true; |
| } |
| } |
| } |
| |
| CharUnits UnpackedBaseAlign = Layout.getNonVirtualAlign(); |
| CharUnits BaseAlign = (Packed) ? CharUnits::One() : UnpackedBaseAlign; |
| |
| // If we have an empty base class, try to place it at offset 0. |
| if (Base->Class->isEmpty() && |
| (!HasExternalLayout || Offset == CharUnits::Zero()) && |
| EmptySubobjects->CanPlaceBaseAtOffset(Base, CharUnits::Zero())) { |
| setSize(std::max(getSize(), Layout.getSize())); |
| UpdateAlignment(BaseAlign, UnpackedBaseAlign); |
| |
| return CharUnits::Zero(); |
| } |
| |
| // The maximum field alignment overrides base align. |
| if (!MaxFieldAlignment.isZero()) { |
| BaseAlign = std::min(BaseAlign, MaxFieldAlignment); |
| UnpackedBaseAlign = std::min(UnpackedBaseAlign, MaxFieldAlignment); |
| } |
| |
| if (!HasExternalLayout) { |
| // Round up the current record size to the base's alignment boundary. |
| Offset = getDataSize().RoundUpToAlignment(BaseAlign); |
| |
| // Try to place the base. |
| while (!EmptySubobjects->CanPlaceBaseAtOffset(Base, Offset)) |
| Offset += BaseAlign; |
| } else { |
| bool Allowed = EmptySubobjects->CanPlaceBaseAtOffset(Base, Offset); |
| (void)Allowed; |
| assert(Allowed && "Base subobject externally placed at overlapping offset"); |
| |
| if (InferAlignment && Offset < getDataSize().RoundUpToAlignment(BaseAlign)){ |
| // The externally-supplied base offset is before the base offset we |
| // computed. Assume that the structure is packed. |
| Alignment = CharUnits::One(); |
| InferAlignment = false; |
| } |
| } |
| |
| if (!Base->Class->isEmpty()) { |
| // Update the data size. |
| setDataSize(Offset + Layout.getNonVirtualSize()); |
| |
| setSize(std::max(getSize(), getDataSize())); |
| } else |
| setSize(std::max(getSize(), Offset + Layout.getSize())); |
| |
| // Remember max struct/class alignment. |
| UpdateAlignment(BaseAlign, UnpackedBaseAlign); |
| |
| return Offset; |
| } |
| |
| void RecordLayoutBuilder::InitializeLayout(const Decl *D) { |
| if (const RecordDecl *RD = dyn_cast<RecordDecl>(D)) { |
| IsUnion = RD->isUnion(); |
| IsMsStruct = RD->isMsStruct(Context); |
| } |
| |
| Packed = D->hasAttr<PackedAttr>(); |
| |
| // Honor the default struct packing maximum alignment flag. |
| if (unsigned DefaultMaxFieldAlignment = Context.getLangOpts().PackStruct) { |
| MaxFieldAlignment = CharUnits::fromQuantity(DefaultMaxFieldAlignment); |
| } |
| |
| // mac68k alignment supersedes maximum field alignment and attribute aligned, |
| // and forces all structures to have 2-byte alignment. The IBM docs on it |
| // allude to additional (more complicated) semantics, especially with regard |
| // to bit-fields, but gcc appears not to follow that. |
| if (D->hasAttr<AlignMac68kAttr>()) { |
| IsMac68kAlign = true; |
| MaxFieldAlignment = CharUnits::fromQuantity(2); |
| Alignment = CharUnits::fromQuantity(2); |
| } else { |
| if (const MaxFieldAlignmentAttr *MFAA = D->getAttr<MaxFieldAlignmentAttr>()) |
| MaxFieldAlignment = Context.toCharUnitsFromBits(MFAA->getAlignment()); |
| |
| if (unsigned MaxAlign = D->getMaxAlignment()) |
| UpdateAlignment(Context.toCharUnitsFromBits(MaxAlign)); |
| } |
| |
| // If there is an external AST source, ask it for the various offsets. |
| if (const RecordDecl *RD = dyn_cast<RecordDecl>(D)) |
| if (ExternalASTSource *External = Context.getExternalSource()) { |
| ExternalLayout = External->layoutRecordType(RD, |
| ExternalSize, |
| ExternalAlign, |
| ExternalFieldOffsets, |
| ExternalBaseOffsets, |
| ExternalVirtualBaseOffsets); |
| |
| // Update based on external alignment. |
| if (ExternalLayout) { |
| if (ExternalAlign > 0) { |
| Alignment = Context.toCharUnitsFromBits(ExternalAlign); |
| } else { |
| // The external source didn't have alignment information; infer it. |
| InferAlignment = true; |
| } |
| } |
| } |
| } |
| |
| void RecordLayoutBuilder::Layout(const RecordDecl *D) { |
| InitializeLayout(D); |
| LayoutFields(D); |
| |
| // Finally, round the size of the total struct up to the alignment of the |
| // struct itself. |
| FinishLayout(D); |
| } |
| |
| void RecordLayoutBuilder::Layout(const CXXRecordDecl *RD) { |
| InitializeLayout(RD); |
| |
| // Lay out the vtable and the non-virtual bases. |
| LayoutNonVirtualBases(RD); |
| |
| LayoutFields(RD); |
| |
| NonVirtualSize = Context.toCharUnitsFromBits( |
| llvm::RoundUpToAlignment(getSizeInBits(), |
| Context.getTargetInfo().getCharAlign())); |
| NonVirtualAlignment = Alignment; |
| |
| // Lay out the virtual bases and add the primary virtual base offsets. |
| LayoutVirtualBases(RD, RD); |
| |
| // Finally, round the size of the total struct up to the alignment |
| // of the struct itself. |
| FinishLayout(RD); |
| |
| #ifndef NDEBUG |
| // Check that we have base offsets for all bases. |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| if (I->isVirtual()) |
| continue; |
| |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| assert(Bases.count(BaseDecl) && "Did not find base offset!"); |
| } |
| |
| // And all virtual bases. |
| for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(), |
| E = RD->vbases_end(); I != E; ++I) { |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| assert(VBases.count(BaseDecl) && "Did not find base offset!"); |
| } |
| #endif |
| } |
| |
| void RecordLayoutBuilder::Layout(const ObjCInterfaceDecl *D) { |
| if (ObjCInterfaceDecl *SD = D->getSuperClass()) { |
| const ASTRecordLayout &SL = Context.getASTObjCInterfaceLayout(SD); |
| |
| UpdateAlignment(SL.getAlignment()); |
| |
| // We start laying out ivars not at the end of the superclass |
| // structure, but at the next byte following the last field. |
| setSize(SL.getDataSize()); |
| setDataSize(getSize()); |
| } |
| |
| InitializeLayout(D); |
| // Layout each ivar sequentially. |
| for (const ObjCIvarDecl *IVD = D->all_declared_ivar_begin(); IVD; |
| IVD = IVD->getNextIvar()) |
| LayoutField(IVD); |
| |
| // Finally, round the size of the total struct up to the alignment of the |
| // struct itself. |
| FinishLayout(D); |
| } |
| |
| void RecordLayoutBuilder::LayoutFields(const RecordDecl *D) { |
| // Layout each field, for now, just sequentially, respecting alignment. In |
| // the future, this will need to be tweakable by targets. |
| for (RecordDecl::field_iterator Field = D->field_begin(), |
| FieldEnd = D->field_end(); Field != FieldEnd; ++Field) |
| LayoutField(*Field); |
| } |
| |
| void RecordLayoutBuilder::LayoutWideBitField(uint64_t FieldSize, |
| uint64_t TypeSize, |
| bool FieldPacked, |
| const FieldDecl *D) { |
| assert(Context.getLangOpts().CPlusPlus && |
| "Can only have wide bit-fields in C++!"); |
| |
| // Itanium C++ ABI 2.4: |
| // If sizeof(T)*8 < n, let T' be the largest integral POD type with |
| // sizeof(T')*8 <= n. |
| |
| QualType IntegralPODTypes[] = { |
| Context.UnsignedCharTy, Context.UnsignedShortTy, Context.UnsignedIntTy, |
| Context.UnsignedLongTy, Context.UnsignedLongLongTy |
| }; |
| |
| QualType Type; |
| for (unsigned I = 0, E = llvm::array_lengthof(IntegralPODTypes); |
| I != E; ++I) { |
| uint64_t Size = Context.getTypeSize(IntegralPODTypes[I]); |
| |
| if (Size > FieldSize) |
| break; |
| |
| Type = IntegralPODTypes[I]; |
| } |
| assert(!Type.isNull() && "Did not find a type!"); |
| |
| CharUnits TypeAlign = Context.getTypeAlignInChars(Type); |
| |
| // We're not going to use any of the unfilled bits in the last byte. |
| UnfilledBitsInLastUnit = 0; |
| LastBitfieldTypeSize = 0; |
| |
| uint64_t FieldOffset; |
| uint64_t UnpaddedFieldOffset = getDataSizeInBits() - UnfilledBitsInLastUnit; |
| |
| if (IsUnion) { |
| setDataSize(std::max(getDataSizeInBits(), FieldSize)); |
| FieldOffset = 0; |
| } else { |
| // The bitfield is allocated starting at the next offset aligned |
| // appropriately for T', with length n bits. |
| FieldOffset = llvm::RoundUpToAlignment(getDataSizeInBits(), |
| Context.toBits(TypeAlign)); |
| |
| uint64_t NewSizeInBits = FieldOffset + FieldSize; |
| |
| setDataSize(llvm::RoundUpToAlignment(NewSizeInBits, |
| Context.getTargetInfo().getCharAlign())); |
| UnfilledBitsInLastUnit = getDataSizeInBits() - NewSizeInBits; |
| } |
| |
| // Place this field at the current location. |
| FieldOffsets.push_back(FieldOffset); |
| |
| CheckFieldPadding(FieldOffset, UnpaddedFieldOffset, FieldOffset, |
| Context.toBits(TypeAlign), FieldPacked, D); |
| |
| // Update the size. |
| setSize(std::max(getSizeInBits(), getDataSizeInBits())); |
| |
| // Remember max struct/class alignment. |
| UpdateAlignment(TypeAlign); |
| } |
| |
| void RecordLayoutBuilder::LayoutBitField(const FieldDecl *D) { |
| bool FieldPacked = Packed || D->hasAttr<PackedAttr>(); |
| uint64_t FieldSize = D->getBitWidthValue(Context); |
| std::pair<uint64_t, unsigned> FieldInfo = Context.getTypeInfo(D->getType()); |
| uint64_t TypeSize = FieldInfo.first; |
| unsigned FieldAlign = FieldInfo.second; |
| |
| if (IsMsStruct) { |
| // The field alignment for integer types in ms_struct structs is |
| // always the size. |
| FieldAlign = TypeSize; |
| // Ignore zero-length bitfields after non-bitfields in ms_struct structs. |
| if (!FieldSize && !LastBitfieldTypeSize) |
| FieldAlign = 1; |
| // If a bitfield is followed by a bitfield of a different size, don't |
| // pack the bits together in ms_struct structs. |
| if (LastBitfieldTypeSize != TypeSize) { |
| UnfilledBitsInLastUnit = 0; |
| LastBitfieldTypeSize = 0; |
| } |
| } |
| |
| uint64_t UnpaddedFieldOffset = getDataSizeInBits() - UnfilledBitsInLastUnit; |
| uint64_t FieldOffset = IsUnion ? 0 : UnpaddedFieldOffset; |
| |
| bool ZeroLengthBitfield = false; |
| if (!Context.getTargetInfo().useBitFieldTypeAlignment() && |
| Context.getTargetInfo().useZeroLengthBitfieldAlignment() && |
| FieldSize == 0) { |
| // The alignment of a zero-length bitfield affects the alignment |
| // of the next member. The alignment is the max of the zero |
| // length bitfield's alignment and a target specific fixed value. |
| ZeroLengthBitfield = true; |
| unsigned ZeroLengthBitfieldBoundary = |
| Context.getTargetInfo().getZeroLengthBitfieldBoundary(); |
| if (ZeroLengthBitfieldBoundary > FieldAlign) |
| FieldAlign = ZeroLengthBitfieldBoundary; |
| } |
| |
| if (FieldSize > TypeSize) { |
| LayoutWideBitField(FieldSize, TypeSize, FieldPacked, D); |
| return; |
| } |
| |
| // The align if the field is not packed. This is to check if the attribute |
| // was unnecessary (-Wpacked). |
| unsigned UnpackedFieldAlign = FieldAlign; |
| uint64_t UnpackedFieldOffset = FieldOffset; |
| if (!Context.getTargetInfo().useBitFieldTypeAlignment() && !ZeroLengthBitfield) |
| UnpackedFieldAlign = 1; |
| |
| if (FieldPacked || |
| (!Context.getTargetInfo().useBitFieldTypeAlignment() && !ZeroLengthBitfield)) |
| FieldAlign = 1; |
| FieldAlign = std::max(FieldAlign, D->getMaxAlignment()); |
| UnpackedFieldAlign = std::max(UnpackedFieldAlign, D->getMaxAlignment()); |
| |
| // The maximum field alignment overrides the aligned attribute. |
| if (!MaxFieldAlignment.isZero() && FieldSize != 0) { |
| unsigned MaxFieldAlignmentInBits = Context.toBits(MaxFieldAlignment); |
| FieldAlign = std::min(FieldAlign, MaxFieldAlignmentInBits); |
| UnpackedFieldAlign = std::min(UnpackedFieldAlign, MaxFieldAlignmentInBits); |
| } |
| |
| // ms_struct bitfields always have to start at a round alignment. |
| if (IsMsStruct && !LastBitfieldTypeSize) { |
| FieldOffset = llvm::RoundUpToAlignment(FieldOffset, FieldAlign); |
| UnpackedFieldOffset = llvm::RoundUpToAlignment(UnpackedFieldOffset, |
| UnpackedFieldAlign); |
| } |
| |
| // Check if we need to add padding to give the field the correct alignment. |
| if (FieldSize == 0 || |
| (MaxFieldAlignment.isZero() && |
| (FieldOffset & (FieldAlign-1)) + FieldSize > TypeSize)) |
| FieldOffset = llvm::RoundUpToAlignment(FieldOffset, FieldAlign); |
| |
| if (FieldSize == 0 || |
| (MaxFieldAlignment.isZero() && |
| (UnpackedFieldOffset & (UnpackedFieldAlign-1)) + FieldSize > TypeSize)) |
| UnpackedFieldOffset = llvm::RoundUpToAlignment(UnpackedFieldOffset, |
| UnpackedFieldAlign); |
| |
| // Padding members don't affect overall alignment, unless zero length bitfield |
| // alignment is enabled. |
| if (!D->getIdentifier() && |
| !Context.getTargetInfo().useZeroLengthBitfieldAlignment() && |
| !IsMsStruct) |
| FieldAlign = UnpackedFieldAlign = 1; |
| |
| if (ExternalLayout) |
| FieldOffset = updateExternalFieldOffset(D, FieldOffset); |
| |
| // Place this field at the current location. |
| FieldOffsets.push_back(FieldOffset); |
| |
| if (!ExternalLayout) |
| CheckFieldPadding(FieldOffset, UnpaddedFieldOffset, UnpackedFieldOffset, |
| UnpackedFieldAlign, FieldPacked, D); |
| |
| // Update DataSize to include the last byte containing (part of) the bitfield. |
| if (IsUnion) { |
| // FIXME: I think FieldSize should be TypeSize here. |
| setDataSize(std::max(getDataSizeInBits(), FieldSize)); |
| } else { |
| if (IsMsStruct && FieldSize) { |
| // Under ms_struct, a bitfield always takes up space equal to the size |
| // of the type. We can't just change the alignment computation on the |
| // other codepath because of the way this interacts with #pragma pack: |
| // in a packed struct, we need to allocate misaligned space in the |
| // struct to hold the bitfield. |
| if (!UnfilledBitsInLastUnit) { |
| setDataSize(FieldOffset + TypeSize); |
| UnfilledBitsInLastUnit = TypeSize - FieldSize; |
| } else if (UnfilledBitsInLastUnit < FieldSize) { |
| setDataSize(getDataSizeInBits() + TypeSize); |
| UnfilledBitsInLastUnit = TypeSize - FieldSize; |
| } else { |
| UnfilledBitsInLastUnit -= FieldSize; |
| } |
| LastBitfieldTypeSize = TypeSize; |
| } else { |
| uint64_t NewSizeInBits = FieldOffset + FieldSize; |
| uint64_t BitfieldAlignment = Context.getTargetInfo().getCharAlign(); |
| setDataSize(llvm::RoundUpToAlignment(NewSizeInBits, BitfieldAlignment)); |
| UnfilledBitsInLastUnit = getDataSizeInBits() - NewSizeInBits; |
| LastBitfieldTypeSize = 0; |
| } |
| } |
| |
| // Update the size. |
| setSize(std::max(getSizeInBits(), getDataSizeInBits())); |
| |
| // Remember max struct/class alignment. |
| UpdateAlignment(Context.toCharUnitsFromBits(FieldAlign), |
| Context.toCharUnitsFromBits(UnpackedFieldAlign)); |
| } |
| |
| void RecordLayoutBuilder::LayoutField(const FieldDecl *D) { |
| if (D->isBitField()) { |
| LayoutBitField(D); |
| return; |
| } |
| |
| uint64_t UnpaddedFieldOffset = getDataSizeInBits() - UnfilledBitsInLastUnit; |
| |
| // Reset the unfilled bits. |
| UnfilledBitsInLastUnit = 0; |
| LastBitfieldTypeSize = 0; |
| |
| bool FieldPacked = Packed || D->hasAttr<PackedAttr>(); |
| CharUnits FieldOffset = |
| IsUnion ? CharUnits::Zero() : getDataSize(); |
| CharUnits FieldSize; |
| CharUnits FieldAlign; |
| |
| if (D->getType()->isIncompleteArrayType()) { |
| // This is a flexible array member; we can't directly |
| // query getTypeInfo about these, so we figure it out here. |
| // Flexible array members don't have any size, but they |
| // have to be aligned appropriately for their element type. |
| FieldSize = CharUnits::Zero(); |
| const ArrayType* ATy = Context.getAsArrayType(D->getType()); |
| FieldAlign = Context.getTypeAlignInChars(ATy->getElementType()); |
| } else if (const ReferenceType *RT = D->getType()->getAs<ReferenceType>()) { |
| unsigned AS = RT->getPointeeType().getAddressSpace(); |
| FieldSize = |
| Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(AS)); |
| FieldAlign = |
| Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerAlign(AS)); |
| } else { |
| std::pair<CharUnits, CharUnits> FieldInfo = |
| Context.getTypeInfoInChars(D->getType()); |
| FieldSize = FieldInfo.first; |
| FieldAlign = FieldInfo.second; |
| |
| if (IsMsStruct) { |
| // If MS bitfield layout is required, figure out what type is being |
| // laid out and align the field to the width of that type. |
| |
| // Resolve all typedefs down to their base type and round up the field |
| // alignment if necessary. |
| QualType T = Context.getBaseElementType(D->getType()); |
| if (const BuiltinType *BTy = T->getAs<BuiltinType>()) { |
| CharUnits TypeSize = Context.getTypeSizeInChars(BTy); |
| if (TypeSize > FieldAlign) |
| FieldAlign = TypeSize; |
| } |
| } |
| } |
| |
| // The align if the field is not packed. This is to check if the attribute |
| // was unnecessary (-Wpacked). |
| CharUnits UnpackedFieldAlign = FieldAlign; |
| CharUnits UnpackedFieldOffset = FieldOffset; |
| |
| if (FieldPacked) |
| FieldAlign = CharUnits::One(); |
| CharUnits MaxAlignmentInChars = |
| Context.toCharUnitsFromBits(D->getMaxAlignment()); |
| FieldAlign = std::max(FieldAlign, MaxAlignmentInChars); |
| UnpackedFieldAlign = std::max(UnpackedFieldAlign, MaxAlignmentInChars); |
| |
| // The maximum field alignment overrides the aligned attribute. |
| if (!MaxFieldAlignment.isZero()) { |
| FieldAlign = std::min(FieldAlign, MaxFieldAlignment); |
| UnpackedFieldAlign = std::min(UnpackedFieldAlign, MaxFieldAlignment); |
| } |
| |
| // Round up the current record size to the field's alignment boundary. |
| FieldOffset = FieldOffset.RoundUpToAlignment(FieldAlign); |
| UnpackedFieldOffset = |
| UnpackedFieldOffset.RoundUpToAlignment(UnpackedFieldAlign); |
| |
| if (ExternalLayout) { |
| FieldOffset = Context.toCharUnitsFromBits( |
| updateExternalFieldOffset(D, Context.toBits(FieldOffset))); |
| |
| if (!IsUnion && EmptySubobjects) { |
| // Record the fact that we're placing a field at this offset. |
| bool Allowed = EmptySubobjects->CanPlaceFieldAtOffset(D, FieldOffset); |
| (void)Allowed; |
| assert(Allowed && "Externally-placed field cannot be placed here"); |
| } |
| } else { |
| if (!IsUnion && EmptySubobjects) { |
| // Check if we can place the field at this offset. |
| while (!EmptySubobjects->CanPlaceFieldAtOffset(D, FieldOffset)) { |
| // We couldn't place the field at the offset. Try again at a new offset. |
| FieldOffset += FieldAlign; |
| } |
| } |
| } |
| |
| // Place this field at the current location. |
| FieldOffsets.push_back(Context.toBits(FieldOffset)); |
| |
| if (!ExternalLayout) |
| CheckFieldPadding(Context.toBits(FieldOffset), UnpaddedFieldOffset, |
| Context.toBits(UnpackedFieldOffset), |
| Context.toBits(UnpackedFieldAlign), FieldPacked, D); |
| |
| // Reserve space for this field. |
| uint64_t FieldSizeInBits = Context.toBits(FieldSize); |
| if (IsUnion) |
| setDataSize(std::max(getDataSizeInBits(), FieldSizeInBits)); |
| else |
| setDataSize(FieldOffset + FieldSize); |
| |
| // Update the size. |
| setSize(std::max(getSizeInBits(), getDataSizeInBits())); |
| |
| // Remember max struct/class alignment. |
| UpdateAlignment(FieldAlign, UnpackedFieldAlign); |
| } |
| |
| void RecordLayoutBuilder::FinishLayout(const NamedDecl *D) { |
| // In C++, records cannot be of size 0. |
| if (Context.getLangOpts().CPlusPlus && getSizeInBits() == 0) { |
| if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) { |
| // Compatibility with gcc requires a class (pod or non-pod) |
| // which is not empty but of size 0; such as having fields of |
| // array of zero-length, remains of Size 0 |
| if (RD->isEmpty()) |
| setSize(CharUnits::One()); |
| } |
| else |
| setSize(CharUnits::One()); |
| } |
| |
| // Finally, round the size of the record up to the alignment of the |
| // record itself. |
| uint64_t UnpaddedSize = getSizeInBits() - UnfilledBitsInLastUnit; |
| uint64_t UnpackedSizeInBits = |
| llvm::RoundUpToAlignment(getSizeInBits(), |
| Context.toBits(UnpackedAlignment)); |
| CharUnits UnpackedSize = Context.toCharUnitsFromBits(UnpackedSizeInBits); |
| uint64_t RoundedSize |
| = llvm::RoundUpToAlignment(getSizeInBits(), Context.toBits(Alignment)); |
| |
| if (ExternalLayout) { |
| // If we're inferring alignment, and the external size is smaller than |
| // our size after we've rounded up to alignment, conservatively set the |
| // alignment to 1. |
| if (InferAlignment && ExternalSize < RoundedSize) { |
| Alignment = CharUnits::One(); |
| InferAlignment = false; |
| } |
| setSize(ExternalSize); |
| return; |
| } |
| |
| // Set the size to the final size. |
| setSize(RoundedSize); |
| |
| unsigned CharBitNum = Context.getTargetInfo().getCharWidth(); |
| if (const RecordDecl *RD = dyn_cast<RecordDecl>(D)) { |
| // Warn if padding was introduced to the struct/class/union. |
| if (getSizeInBits() > UnpaddedSize) { |
| unsigned PadSize = getSizeInBits() - UnpaddedSize; |
| bool InBits = true; |
| if (PadSize % CharBitNum == 0) { |
| PadSize = PadSize / CharBitNum; |
| InBits = false; |
| } |
| Diag(RD->getLocation(), diag::warn_padded_struct_size) |
| << Context.getTypeDeclType(RD) |
| << PadSize |
| << (InBits ? 1 : 0) /*(byte|bit)*/ << (PadSize > 1); // plural or not |
| } |
| |
| // Warn if we packed it unnecessarily. If the alignment is 1 byte don't |
| // bother since there won't be alignment issues. |
| if (Packed && UnpackedAlignment > CharUnits::One() && |
| getSize() == UnpackedSize) |
| Diag(D->getLocation(), diag::warn_unnecessary_packed) |
| << Context.getTypeDeclType(RD); |
| } |
| } |
| |
| void RecordLayoutBuilder::UpdateAlignment(CharUnits NewAlignment, |
| CharUnits UnpackedNewAlignment) { |
| // The alignment is not modified when using 'mac68k' alignment or when |
| // we have an externally-supplied layout that also provides overall alignment. |
| if (IsMac68kAlign || (ExternalLayout && !InferAlignment)) |
| return; |
| |
| if (NewAlignment > Alignment) { |
| assert(llvm::isPowerOf2_32(NewAlignment.getQuantity() && |
| "Alignment not a power of 2")); |
| Alignment = NewAlignment; |
| } |
| |
| if (UnpackedNewAlignment > UnpackedAlignment) { |
| assert(llvm::isPowerOf2_32(UnpackedNewAlignment.getQuantity() && |
| "Alignment not a power of 2")); |
| UnpackedAlignment = UnpackedNewAlignment; |
| } |
| } |
| |
| uint64_t |
| RecordLayoutBuilder::updateExternalFieldOffset(const FieldDecl *Field, |
| uint64_t ComputedOffset) { |
| assert(ExternalFieldOffsets.find(Field) != ExternalFieldOffsets.end() && |
| "Field does not have an external offset"); |
| |
| uint64_t ExternalFieldOffset = ExternalFieldOffsets[Field]; |
| |
| if (InferAlignment && ExternalFieldOffset < ComputedOffset) { |
| // The externally-supplied field offset is before the field offset we |
| // computed. Assume that the structure is packed. |
| Alignment = CharUnits::One(); |
| InferAlignment = false; |
| } |
| |
| // Use the externally-supplied field offset. |
| return ExternalFieldOffset; |
| } |
| |
| /// \brief Get diagnostic %select index for tag kind for |
| /// field padding diagnostic message. |
| /// WARNING: Indexes apply to particular diagnostics only! |
| /// |
| /// \returns diagnostic %select index. |
| static unsigned getPaddingDiagFromTagKind(TagTypeKind Tag) { |
| switch (Tag) { |
| case TTK_Struct: return 0; |
| case TTK_Interface: return 1; |
| case TTK_Class: return 2; |
| default: llvm_unreachable("Invalid tag kind for field padding diagnostic!"); |
| } |
| } |
| |
| void RecordLayoutBuilder::CheckFieldPadding(uint64_t Offset, |
| uint64_t UnpaddedOffset, |
| uint64_t UnpackedOffset, |
| unsigned UnpackedAlign, |
| bool isPacked, |
| const FieldDecl *D) { |
| // We let objc ivars without warning, objc interfaces generally are not used |
| // for padding tricks. |
| if (isa<ObjCIvarDecl>(D)) |
| return; |
| |
| // Don't warn about structs created without a SourceLocation. This can |
| // be done by clients of the AST, such as codegen. |
| if (D->getLocation().isInvalid()) |
| return; |
| |
| unsigned CharBitNum = Context.getTargetInfo().getCharWidth(); |
| |
| // Warn if padding was introduced to the struct/class. |
| if (!IsUnion && Offset > UnpaddedOffset) { |
| unsigned PadSize = Offset - UnpaddedOffset; |
| bool InBits = true; |
| if (PadSize % CharBitNum == 0) { |
| PadSize = PadSize / CharBitNum; |
| InBits = false; |
| } |
| if (D->getIdentifier()) |
| Diag(D->getLocation(), diag::warn_padded_struct_field) |
| << getPaddingDiagFromTagKind(D->getParent()->getTagKind()) |
| << Context.getTypeDeclType(D->getParent()) |
| << PadSize |
| << (InBits ? 1 : 0) /*(byte|bit)*/ << (PadSize > 1) // plural or not |
| << D->getIdentifier(); |
| else |
| Diag(D->getLocation(), diag::warn_padded_struct_anon_field) |
| << getPaddingDiagFromTagKind(D->getParent()->getTagKind()) |
| << Context.getTypeDeclType(D->getParent()) |
| << PadSize |
| << (InBits ? 1 : 0) /*(byte|bit)*/ << (PadSize > 1); // plural or not |
| } |
| |
| // Warn if we packed it unnecessarily. If the alignment is 1 byte don't |
| // bother since there won't be alignment issues. |
| if (isPacked && UnpackedAlign > CharBitNum && Offset == UnpackedOffset) |
| Diag(D->getLocation(), diag::warn_unnecessary_packed) |
| << D->getIdentifier(); |
| } |
| |
| static const CXXMethodDecl *computeKeyFunction(ASTContext &Context, |
| const CXXRecordDecl *RD) { |
| // If a class isn't polymorphic it doesn't have a key function. |
| if (!RD->isPolymorphic()) |
| return 0; |
| |
| // A class that is not externally visible doesn't have a key function. (Or |
| // at least, there's no point to assigning a key function to such a class; |
| // this doesn't affect the ABI.) |
| if (!RD->isExternallyVisible()) |
| return 0; |
| |
| // Template instantiations don't have key functions,see Itanium C++ ABI 5.2.6. |
| // Same behavior as GCC. |
| TemplateSpecializationKind TSK = RD->getTemplateSpecializationKind(); |
| if (TSK == TSK_ImplicitInstantiation || |
| TSK == TSK_ExplicitInstantiationDefinition) |
| return 0; |
| |
| bool allowInlineFunctions = |
| Context.getTargetInfo().getCXXABI().canKeyFunctionBeInline(); |
| |
| for (CXXRecordDecl::method_iterator I = RD->method_begin(), |
| E = RD->method_end(); I != E; ++I) { |
| const CXXMethodDecl *MD = *I; |
| |
| if (!MD->isVirtual()) |
| continue; |
| |
| if (MD->isPure()) |
| continue; |
| |
| // Ignore implicit member functions, they are always marked as inline, but |
| // they don't have a body until they're defined. |
| if (MD->isImplicit()) |
| continue; |
| |
| if (MD->isInlineSpecified()) |
| continue; |
| |
| if (MD->hasInlineBody()) |
| continue; |
| |
| // Ignore inline deleted or defaulted functions. |
| if (!MD->isUserProvided()) |
| continue; |
| |
| // In certain ABIs, ignore functions with out-of-line inline definitions. |
| if (!allowInlineFunctions) { |
| const FunctionDecl *Def; |
| if (MD->hasBody(Def) && Def->isInlineSpecified()) |
| continue; |
| } |
| |
| // We found it. |
| return MD; |
| } |
| |
| return 0; |
| } |
| |
| DiagnosticBuilder |
| RecordLayoutBuilder::Diag(SourceLocation Loc, unsigned DiagID) { |
| return Context.getDiagnostics().Report(Loc, DiagID); |
| } |
| |
| /// Does the target C++ ABI require us to skip over the tail-padding |
| /// of the given class (considering it as a base class) when allocating |
| /// objects? |
| static bool mustSkipTailPadding(TargetCXXABI ABI, const CXXRecordDecl *RD) { |
| switch (ABI.getTailPaddingUseRules()) { |
| case TargetCXXABI::AlwaysUseTailPadding: |
| return false; |
| |
| case TargetCXXABI::UseTailPaddingUnlessPOD03: |
| // FIXME: To the extent that this is meant to cover the Itanium ABI |
| // rules, we should implement the restrictions about over-sized |
| // bitfields: |
| // |
| // http://mentorembedded.github.com/cxx-abi/abi.html#POD : |
| // In general, a type is considered a POD for the purposes of |
| // layout if it is a POD type (in the sense of ISO C++ |
| // [basic.types]). However, a POD-struct or POD-union (in the |
| // sense of ISO C++ [class]) with a bitfield member whose |
| // declared width is wider than the declared type of the |
| // bitfield is not a POD for the purpose of layout. Similarly, |
| // an array type is not a POD for the purpose of layout if the |
| // element type of the array is not a POD for the purpose of |
| // layout. |
| // |
| // Where references to the ISO C++ are made in this paragraph, |
| // the Technical Corrigendum 1 version of the standard is |
| // intended. |
| return RD->isPOD(); |
| |
| case TargetCXXABI::UseTailPaddingUnlessPOD11: |
| // This is equivalent to RD->getTypeForDecl().isCXX11PODType(), |
| // but with a lot of abstraction penalty stripped off. This does |
| // assume that these properties are set correctly even in C++98 |
| // mode; fortunately, that is true because we want to assign |
| // consistently semantics to the type-traits intrinsics (or at |
| // least as many of them as possible). |
| return RD->isTrivial() && RD->isStandardLayout(); |
| } |
| |
| llvm_unreachable("bad tail-padding use kind"); |
| } |
| |
| static bool isMsLayout(const RecordDecl* D) { |
| return D->getASTContext().getTargetInfo().getCXXABI().isMicrosoft(); |
| } |
| |
| // This section contains an implementation of struct layout that is, up to the |
| // included tests, compatible with cl.exe (2012). The layout produced is |
| // significantly different than those produced by the Itanium ABI. Here we note |
| // the most important differences. |
| // |
| // * The alignment of bitfields in unions is ignored when computing the |
| // alignment of the union. |
| // * The existance of zero-width bitfield that occurs after anything other than |
| // a non-zero length bitfield is ignored. |
| // * The Itanium equivalent vtable pointers are split into a vfptr (virtual |
| // function pointer) and a vbptr (virtual base pointer). They can each be |
| // shared with a, non-virtual bases. These bases need not be the same. vfptrs |
| // always occur at offset 0. vbptrs can occur at an |
| // arbitrary offset and are placed after non-virtual bases but before fields. |
| // * Virtual bases sometimes require a 'vtordisp' field that is laid out before |
| // the virtual base and is used in conjunction with virtual overrides during |
| // construction and destruction. |
| // * vfptrs are allocated in a block of memory equal to the alignment of the |
| // fields and non-virtual bases at offset 0 in 32 bit mode and in a pointer |
| // sized block of memory in 64 bit mode. |
| // * vbptrs are allocated in a block of memory equal to the alignment of the |
| // fields and non-virtual bases. This block is at a potentially unaligned |
| // offset. If the allocation slot is unaligned and the alignment is less than |
| // or equal to the pointer size, additional space is allocated so that the |
| // pointer can be aligned properly. This causes very strange effects on the |
| // placement of objects after the allocated block. (see the code). |
| // * vtordisps are allocated in a block of memory with size and alignment equal |
| // to the alignment of the completed structure (before applying __declspec( |
| // align())). The vtordisp always occur at the end of the allocation block, |
| // immediately prior to the virtual base. |
| // * The last zero sized non-virtual base is allocated after the placement of |
| // vbptr if one exists and can be placed at the end of the struct, potentially |
| // aliasing either the first member or another struct allocated after this |
| // one. |
| // * The last zero size virtual base may be placed at the end of the struct. |
| // and can potentially alias a zero sized type in the next struct. |
| |
| namespace { |
| struct MicrosoftRecordLayoutBuilder { |
| typedef llvm::DenseMap<const CXXRecordDecl *, CharUnits> BaseOffsetsMapTy; |
| MicrosoftRecordLayoutBuilder(const ASTContext &Context) : Context(Context) {} |
| private: |
| MicrosoftRecordLayoutBuilder(const MicrosoftRecordLayoutBuilder &) |
| LLVM_DELETED_FUNCTION; |
| void operator=(const MicrosoftRecordLayoutBuilder &) LLVM_DELETED_FUNCTION; |
| public: |
| |
| void layout(const RecordDecl *RD); |
| void cxxLayout(const CXXRecordDecl *RD); |
| /// \brief Initializes size and alignment and honors some flags. |
| void initializeLayout(const RecordDecl *RD); |
| /// \brief Initialized C++ layout, compute alignment and virtual alignment and |
| /// existance of vfptrs and vbptrs. Alignment is needed before the vfptr is |
| /// laid out. |
| void initializeCXXLayout(const CXXRecordDecl *RD); |
| void layoutVFPtr(const CXXRecordDecl *RD); |
| void layoutNonVirtualBases(const CXXRecordDecl *RD); |
| void layoutNonVirtualBase(const CXXRecordDecl *RD); |
| void layoutVBPtr(const CXXRecordDecl *RD); |
| /// \brief Lays out the fields of the record. Also rounds size up to |
| /// alignment. |
| void layoutFields(const RecordDecl *RD); |
| void layoutField(const FieldDecl *FD); |
| void layoutBitField(const FieldDecl *FD); |
| /// \brief Lays out a single zero-width bit-field in the record and handles |
| /// special cases associated with zero-width bit-fields. |
| void layoutZeroWidthBitField(const FieldDecl *FD); |
| void layoutVirtualBases(const CXXRecordDecl *RD); |
| void layoutVirtualBase(const CXXRecordDecl *RD, bool HasVtordisp); |
| /// \brief Flushes the lazy virtual base and conditionally rounds up to |
| /// alignment. |
| void finalizeCXXLayout(const CXXRecordDecl *RD); |
| void honorDeclspecAlign(const RecordDecl *RD); |
| |
| /// \brief Updates the alignment of the type. This function doesn't take any |
| /// properties (such as packedness) into account. getAdjustedFieldInfo() |
| /// adjustes for packedness. |
| void updateAlignment(CharUnits NewAlignment) { |
| Alignment = std::max(Alignment, NewAlignment); |
| } |
| /// \brief Gets the size and alignment taking attributes into account. |
| std::pair<CharUnits, CharUnits> getAdjustedFieldInfo(const FieldDecl *FD); |
| /// \brief Places a field at offset 0. |
| void placeFieldAtZero() { FieldOffsets.push_back(0); } |
| /// \brief Places a field at an offset in CharUnits. |
| void placeFieldAtOffset(CharUnits FieldOffset) { |
| FieldOffsets.push_back(Context.toBits(FieldOffset)); |
| } |
| /// \brief Places a bitfield at a bit offset. |
| void placeFieldAtBitOffset(uint64_t FieldOffset) { |
| FieldOffsets.push_back(FieldOffset); |
| } |
| /// \brief Compute the set of virtual bases for which vtordisps are required. |
| llvm::SmallPtrSet<const CXXRecordDecl *, 2> |
| computeVtorDispSet(const CXXRecordDecl *RD); |
| |
| const ASTContext &Context; |
| /// \brief The size of the record being laid out. |
| CharUnits Size; |
| /// \brief The current alignment of the record layout. |
| CharUnits Alignment; |
| /// \brief The collection of field offsets. |
| SmallVector<uint64_t, 16> FieldOffsets; |
| /// \brief The maximum allowed field alignment. This is set by #pragma pack. |
| CharUnits MaxFieldAlignment; |
| /// \brief Alignment does not occur for virtual bases unless something |
| /// forces it to by explicitly using __declspec(align()) |
| bool AlignAfterVBases : 1; |
| bool IsUnion : 1; |
| /// \brief True if the last field laid out was a bitfield and was not 0 |
| /// width. |
| bool LastFieldIsNonZeroWidthBitfield : 1; |
| /// \brief The size of the allocation of the currently active bitfield. |
| /// This value isn't meaningful unless LastFieldIsNonZeroWidthBitfield |
| /// is true. |
| CharUnits CurrentBitfieldSize; |
| /// \brief The number of remaining bits in our last bitfield allocation. |
| /// This value isn't meaningful unless LastFieldIsNonZeroWidthBitfield is |
| /// true. |
| unsigned RemainingBitsInField; |
| |
| /// \brief The data alignment of the record layout. |
| CharUnits DataSize; |
| /// \brief The alignment of the non-virtual portion of the record layout |
| /// without the impact of the virtual pointers. |
| /// Only used for C++ layouts. |
| CharUnits BasesAndFieldsAlignment; |
| /// \brief The alignment of the non-virtual portion of the record layout |
| /// Only used for C++ layouts. |
| CharUnits NonVirtualAlignment; |
| /// \brief The additional alignment imposed by the virtual bases. |
| CharUnits VirtualAlignment; |
| /// \brief The primary base class (if one exists). |
| const CXXRecordDecl *PrimaryBase; |
| /// \brief The class we share our vb-pointer with. |
| const CXXRecordDecl *SharedVBPtrBase; |
| /// \brief True if the class has a (not necessarily its own) vftable pointer. |
| bool HasVFPtr : 1; |
| /// \brief True if the class has a (not necessarily its own) vbtable pointer. |
| bool HasVBPtr : 1; |
| /// \brief Offset to the virtual base table pointer (if one exists). |
| CharUnits VBPtrOffset; |
| /// \brief Base classes and their offsets in the record. |
| BaseOffsetsMapTy Bases; |
| /// \brief virtual base classes and their offsets in the record. |
| ASTRecordLayout::VBaseOffsetsMapTy VBases; |
| /// \brief The size of a pointer. |
| CharUnits PointerSize; |
| /// \brief The alignment of a pointer. |
| CharUnits PointerAlignment; |
| /// \brief Holds an empty base we haven't yet laid out. |
| const CXXRecordDecl *LazyEmptyBase; |
| /// \brief Lets us know if the last base we laid out was empty. Only used |
| /// when adjusting the placement of a last zero-sized base in 64 bit mode. |
| bool LastBaseWasEmpty; |
| /// \brief Lets us know if we're in 64-bit mode |
| bool Is64BitMode; |
| }; |
| } // namespace |
| |
| std::pair<CharUnits, CharUnits> |
| MicrosoftRecordLayoutBuilder::getAdjustedFieldInfo(const FieldDecl *FD) { |
| std::pair<CharUnits, CharUnits> FieldInfo; |
| if (FD->getType()->isIncompleteArrayType()) { |
| // This is a flexible array member; we can't directly |
| // query getTypeInfo about these, so we figure it out here. |
| // Flexible array members don't have any size, but they |
| // have to be aligned appropriately for their element type. |
| FieldInfo.first = CharUnits::Zero(); |
| const ArrayType *ATy = Context.getAsArrayType(FD->getType()); |
| FieldInfo.second = Context.getTypeAlignInChars(ATy->getElementType()); |
| } else if (const ReferenceType *RT = FD->getType()->getAs<ReferenceType>()) { |
| unsigned AS = RT->getPointeeType().getAddressSpace(); |
| FieldInfo.first = Context |
| .toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(AS)); |
| FieldInfo.second = Context |
| .toCharUnitsFromBits(Context.getTargetInfo().getPointerAlign(AS)); |
| } else |
| FieldInfo = Context.getTypeInfoInChars(FD->getType()); |
| |
| // If we're not on win32 and using ms_struct the field alignment will be wrong |
| // for 64 bit types, so we fix that here. |
| if (FD->getASTContext().getTargetInfo().getTriple().getOS() != |
| llvm::Triple::Win32) { |
| QualType T = Context.getBaseElementType(FD->getType()); |
| if (const BuiltinType *BTy = T->getAs<BuiltinType>()) { |
| CharUnits TypeSize = Context.getTypeSizeInChars(BTy); |
| if (TypeSize > FieldInfo.second) |
| FieldInfo.second = TypeSize; |
| } |
| } |
| |
| // Respect packed attribute. |
| if (FD->hasAttr<PackedAttr>()) |
| FieldInfo.second = CharUnits::One(); |
| // Respect pack pragma. |
| else if (!MaxFieldAlignment.isZero()) |
| FieldInfo.second = std::min(FieldInfo.second, MaxFieldAlignment); |
| // Respect alignment attributes. |
| if (unsigned fieldAlign = FD->getMaxAlignment()) { |
| CharUnits FieldAlign = Context.toCharUnitsFromBits(fieldAlign); |
| AlignAfterVBases = true; |
| FieldInfo.second = std::max(FieldInfo.second, FieldAlign); |
| } |
| return FieldInfo; |
| } |
| |
| void MicrosoftRecordLayoutBuilder::initializeLayout(const RecordDecl *RD) { |
| IsUnion = RD->isUnion(); |
| Is64BitMode = RD->getASTContext().getTargetInfo().getTriple().getArch() == |
| llvm::Triple::x86_64; |
| |
| Size = CharUnits::Zero(); |
| Alignment = CharUnits::One(); |
| AlignAfterVBases = false; |
| |
| // Compute the maximum field alignment. |
| MaxFieldAlignment = CharUnits::Zero(); |
| // Honor the default struct packing maximum alignment flag. |
| if (unsigned DefaultMaxFieldAlignment = Context.getLangOpts().PackStruct) |
| MaxFieldAlignment = CharUnits::fromQuantity(DefaultMaxFieldAlignment); |
| // Honor the packing attribute. |
| if (const MaxFieldAlignmentAttr *MFAA = RD->getAttr<MaxFieldAlignmentAttr>()) |
| MaxFieldAlignment = Context.toCharUnitsFromBits(MFAA->getAlignment()); |
| // Packed attribute forces max field alignment to be 1. |
| if (RD->hasAttr<PackedAttr>()) |
| MaxFieldAlignment = CharUnits::One(); |
| } |
| |
| void MicrosoftRecordLayoutBuilder::layout(const RecordDecl *RD) { |
| initializeLayout(RD); |
| layoutFields(RD); |
| honorDeclspecAlign(RD); |
| } |
| |
| void MicrosoftRecordLayoutBuilder::cxxLayout(const CXXRecordDecl *RD) { |
| initializeLayout(RD); |
| initializeCXXLayout(RD); |
| layoutVFPtr(RD); |
| layoutNonVirtualBases(RD); |
| layoutVBPtr(RD); |
| layoutFields(RD); |
| DataSize = Size; |
| NonVirtualAlignment = Alignment; |
| layoutVirtualBases(RD); |
| finalizeCXXLayout(RD); |
| honorDeclspecAlign(RD); |
| } |
| |
| void |
| MicrosoftRecordLayoutBuilder::initializeCXXLayout(const CXXRecordDecl *RD) { |
| // Calculate pointer size and alignment. |
| PointerSize = |
| Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0)); |
| PointerAlignment = PointerSize; |
| if (!MaxFieldAlignment.isZero()) |
| PointerAlignment = std::min(PointerAlignment, MaxFieldAlignment); |
| |
| // Initialize information about the bases. |
| HasVBPtr = false; |
| HasVFPtr = false; |
| SharedVBPtrBase = 0; |
| PrimaryBase = 0; |
| VirtualAlignment = CharUnits::One(); |
| AlignAfterVBases = Is64BitMode; |
| |
| // If the record has a dynamic base class, attempt to choose a primary base |
| // class. It is the first (in direct base class order) non-virtual dynamic |
| // base class, if one exists. |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); |
| i != e; ++i) { |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(BaseDecl); |
| // Handle forced alignment. |
| if (Layout.getAlignAfterVBases()) |
| AlignAfterVBases = true; |
| // Handle virtual bases. |
| if (i->isVirtual()) { |
| VirtualAlignment = std::max(VirtualAlignment, Layout.getAlignment()); |
| HasVBPtr = true; |
| continue; |
| } |
| // We located a primary base class! |
| if (!PrimaryBase && Layout.hasVFPtr()) { |
| PrimaryBase = BaseDecl; |
| HasVFPtr = true; |
| } |
| // We located a base to share a VBPtr with! |
| if (!SharedVBPtrBase && Layout.hasVBPtr()) { |
| SharedVBPtrBase = BaseDecl; |
| HasVBPtr = true; |
| } |
| updateAlignment(Layout.getAlignment()); |
| } |
| |
| // Use LayoutFields to compute the alignment of the fields. The layout |
| // is discarded. This is the simplest way to get all of the bit-field |
| // behavior correct and is not actually very expensive. |
| layoutFields(RD); |
| Size = CharUnits::Zero(); |
| BasesAndFieldsAlignment = Alignment; |
| FieldOffsets.clear(); |
| } |
| |
| void MicrosoftRecordLayoutBuilder::layoutVFPtr(const CXXRecordDecl *RD) { |
| // If we have a primary base then our VFPtr was already laid out |
| if (PrimaryBase) |
| return; |
| |
| // Look at all of our methods to determine if we need a VFPtr. We need a |
| // vfptr if we define a new virtual function. |
| if (!HasVFPtr && RD->isDynamicClass()) |
| for (CXXRecordDecl::method_iterator i = RD->method_begin(), |
| e = RD->method_end(); |
| !HasVFPtr && i != e; ++i) |
| HasVFPtr = i->isVirtual() && i->size_overridden_methods() == 0; |
| if (!HasVFPtr) |
| return; |
| |
| // MSVC 32 (but not 64) potentially over-aligns the vf-table pointer by giving |
| // it the max alignment of all the non-virtual data in the class. The |
| // resulting layout is essentially { vftbl, { nvdata } }. This is completely |
| // unnecessary, but we're not here to pass judgment. |
| updateAlignment(PointerAlignment); |
| if (Is64BitMode) |
| Size = Size.RoundUpToAlignment(PointerAlignment) + PointerSize; |
| else |
| Size = Size.RoundUpToAlignment(PointerAlignment) + Alignment; |
| } |
| |
| void |
| MicrosoftRecordLayoutBuilder::layoutNonVirtualBases(const CXXRecordDecl *RD) { |
| LazyEmptyBase = 0; |
| LastBaseWasEmpty = false; |
| |
| // Lay out the primary base first. |
| if (PrimaryBase) |
| layoutNonVirtualBase(PrimaryBase); |
| |
| // Iterate through the bases and lay out the non-virtual ones. |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); |
| i != e; ++i) { |
| if (i->isVirtual()) |
| continue; |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(i->getType()->castAs<RecordType>()->getDecl()); |
| if (BaseDecl != PrimaryBase) |
| layoutNonVirtualBase(BaseDecl); |
| } |
| } |
| |
| void |
| MicrosoftRecordLayoutBuilder::layoutNonVirtualBase(const CXXRecordDecl *RD) { |
| const ASTRecordLayout *Layout = RD ? &Context.getASTRecordLayout(RD) : 0; |
| |
| // If we have a lazy empty base we haven't laid out yet, do that now. |
| if (LazyEmptyBase) { |
| const ASTRecordLayout &LazyLayout = |
| Context.getASTRecordLayout(LazyEmptyBase); |
| Size = Size.RoundUpToAlignment(LazyLayout.getAlignment()); |
| Bases.insert(std::make_pair(LazyEmptyBase, Size)); |
| // Empty bases only consume space when followed by another empty base. |
| if (RD && Layout->getNonVirtualSize().isZero()) { |
| LastBaseWasEmpty = true; |
| Size++; |
| } |
| LazyEmptyBase = 0; |
| } |
| |
| // RD is null when flushing the final lazy base. |
| if (!RD) |
| return; |
| |
| if (Layout->getNonVirtualSize().isZero()) { |
| LazyEmptyBase = RD; |
| return; |
| } |
| |
| // Insert the base here. |
| CharUnits BaseOffset = Size.RoundUpToAlignment(Layout->getAlignment()); |
| Bases.insert(std::make_pair(RD, BaseOffset)); |
| Size = BaseOffset + Layout->getDataSize(); |
| // Note: we don't update alignment here because it was accounted |
| // for during initalization. |
| LastBaseWasEmpty = false; |
| } |
| |
| void MicrosoftRecordLayoutBuilder::layoutVBPtr(const CXXRecordDecl *RD) { |
| if (!HasVBPtr) |
| VBPtrOffset = CharUnits::fromQuantity(-1); |
| else if (SharedVBPtrBase) { |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(SharedVBPtrBase); |
| VBPtrOffset = Bases[SharedVBPtrBase] + Layout.getVBPtrOffset(); |
| } else { |
| VBPtrOffset = Size.RoundUpToAlignment(PointerAlignment); |
| CharUnits OldSize = Size; |
| Size = VBPtrOffset + PointerSize; |
| if (BasesAndFieldsAlignment <= PointerAlignment) { |
| // Handle strange padding rules for the lazily placed base. I have no |
| // explanation for why the last virtual base is padded in such an odd way. |
| // Two things to note about this padding are that the rules are different |
| // if the alignment of the bases+fields is <= to the alignemnt of a |
| // pointer and that the rule in 64-bit mode behaves differently depending |
| // on if the second to last base was also zero sized. |
| Size += OldSize % BasesAndFieldsAlignment.getQuantity(); |
| } else { |
| if (Is64BitMode) |
| Size += LastBaseWasEmpty ? CharUnits::One() : CharUnits::Zero(); |
| else |
| Size = OldSize + BasesAndFieldsAlignment; |
| } |
| updateAlignment(PointerAlignment); |
| } |
| |
| // Flush the lazy empty base. |
| layoutNonVirtualBase(0); |
| } |
| |
| void MicrosoftRecordLayoutBuilder::layoutFields(const RecordDecl *RD) { |
| LastFieldIsNonZeroWidthBitfield = false; |
| for (RecordDecl::field_iterator Field = RD->field_begin(), |
| FieldEnd = RD->field_end(); |
| Field != FieldEnd; ++Field) |
| layoutField(*Field); |
| Size = Size.RoundUpToAlignment(Alignment); |
| } |
| |
| void MicrosoftRecordLayoutBuilder::layoutField(const FieldDecl *FD) { |
| if (FD->isBitField()) { |
| layoutBitField(FD); |
| return; |
| } |
| LastFieldIsNonZeroWidthBitfield = false; |
| |
| std::pair<CharUnits, CharUnits> FieldInfo = getAdjustedFieldInfo(FD); |
| CharUnits FieldSize = FieldInfo.first; |
| CharUnits FieldAlign = FieldInfo.second; |
| |
| updateAlignment(FieldAlign); |
| if (IsUnion) { |
| placeFieldAtZero(); |
| Size = std::max(Size, FieldSize); |
| } else { |
| // Round up the current record size to the field's alignment boundary. |
| CharUnits FieldOffset = Size.RoundUpToAlignment(FieldAlign); |
| placeFieldAtOffset(FieldOffset); |
| Size = FieldOffset + FieldSize; |
| } |
| } |
| |
| void MicrosoftRecordLayoutBuilder::layoutBitField(const FieldDecl *FD) { |
| unsigned Width = FD->getBitWidthValue(Context); |
| if (Width == 0) { |
| layoutZeroWidthBitField(FD); |
| return; |
| } |
| |
| std::pair<CharUnits, CharUnits> FieldInfo = getAdjustedFieldInfo(FD); |
| CharUnits FieldSize = FieldInfo.first; |
| CharUnits FieldAlign = FieldInfo.second; |
| |
| // Clamp the bitfield to a containable size for the sake of being able |
| // to lay them out. Sema will throw an error. |
| if (Width > Context.toBits(FieldSize)) |
| Width = Context.toBits(FieldSize); |
| |
| // Check to see if this bitfield fits into an existing allocation. Note: |
| // MSVC refuses to pack bitfields of formal types with different sizes |
| // into the same allocation. |
| if (!IsUnion && LastFieldIsNonZeroWidthBitfield && |
| CurrentBitfieldSize == FieldSize && Width <= RemainingBitsInField) { |
| placeFieldAtBitOffset(Context.toBits(Size) - RemainingBitsInField); |
| RemainingBitsInField -= Width; |
| return; |
| } |
| |
| LastFieldIsNonZeroWidthBitfield = true; |
| CurrentBitfieldSize = FieldSize; |
| if (IsUnion) { |
| placeFieldAtZero(); |
| Size = std::max(Size, FieldSize); |
| // TODO: Add a Sema warning that MS ignores bitfield alignment in unions. |
| } else { |
| // Allocate a new block of memory and place the bitfield in it. |
| CharUnits FieldOffset = Size.RoundUpToAlignment(FieldAlign); |
| placeFieldAtOffset(FieldOffset); |
| Size = FieldOffset + FieldSize; |
| updateAlignment(FieldAlign); |
| RemainingBitsInField = Context.toBits(FieldSize) - Width; |
| } |
| } |
| |
| void |
| MicrosoftRecordLayoutBuilder::layoutZeroWidthBitField(const FieldDecl *FD) { |
| // Zero-width bitfields are ignored unless they follow a non-zero-width |
| // bitfield. |
| std::pair<CharUnits, CharUnits> FieldInfo = getAdjustedFieldInfo(FD); |
| CharUnits FieldSize = FieldInfo.first; |
| CharUnits FieldAlign = FieldInfo.second; |
| |
| if (!LastFieldIsNonZeroWidthBitfield) { |
| placeFieldAtOffset(IsUnion ? CharUnits::Zero() : Size); |
| // TODO: Add a Sema warning that MS ignores alignment for zero |
| // sized bitfields that occur after zero-size bitfields or non bitfields. |
| return; |
| } |
| |
| LastFieldIsNonZeroWidthBitfield = false; |
| if (IsUnion) { |
| placeFieldAtZero(); |
| Size = std::max(Size, FieldSize); |
| } else { |
| // Round up the current record size to the field's alignment boundary. |
| CharUnits FieldOffset = Size.RoundUpToAlignment(FieldAlign); |
| placeFieldAtOffset(FieldOffset); |
| Size = FieldOffset; |
| updateAlignment(FieldAlign); |
| } |
| } |
| |
| void MicrosoftRecordLayoutBuilder::layoutVirtualBases(const CXXRecordDecl *RD) { |
| if (!HasVBPtr) |
| return; |
| |
| updateAlignment(VirtualAlignment); |
| |
| // Zero-sized v-bases obey the alignment attribute so apply it here. The |
| // alignment attribute is normally accounted for in FinalizeLayout. |
| if (unsigned MaxAlign = RD->getMaxAlignment()) |
| updateAlignment(Context.toCharUnitsFromBits(MaxAlign)); |
| |
| llvm::SmallPtrSet<const CXXRecordDecl *, 2> HasVtordisp = |
| computeVtorDispSet(RD); |
| |
| // Iterate through the virtual bases and lay them out. |
| for (CXXRecordDecl::base_class_const_iterator i = RD->vbases_begin(), |
| e = RD->vbases_end(); |
| i != e; ++i) { |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(i->getType()->castAs<RecordType>()->getDecl()); |
| layoutVirtualBase(BaseDecl, HasVtordisp.count(BaseDecl)); |
| } |
| } |
| |
| void MicrosoftRecordLayoutBuilder::layoutVirtualBase(const CXXRecordDecl *RD, |
| bool HasVtordisp) { |
| if (LazyEmptyBase) { |
| const ASTRecordLayout &LazyLayout = |
| Context.getASTRecordLayout(LazyEmptyBase); |
| Size = Size.RoundUpToAlignment(LazyLayout.getAlignment()); |
| VBases.insert( |
| std::make_pair(LazyEmptyBase, ASTRecordLayout::VBaseInfo(Size, false))); |
| // Empty bases only consume space when followed by another empty base. |
| // The space consumed is in an Alignment sized/aligned block and the v-base |
| // is placed at its alignment offset into the chunk, unless its alignment |
| // is less than 4 bytes, at which it is placed at 4 byte offset in the |
| // chunk. We have no idea why. |
| if (RD && Context.getASTRecordLayout(RD).getNonVirtualSize().isZero()) |
| Size = Size.RoundUpToAlignment(Alignment) + CharUnits::fromQuantity(4); |
| LazyEmptyBase = 0; |
| } |
| |
| // RD is null when flushing the final lazy virtual base. |
| if (!RD) |
| return; |
| |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); |
| if (Layout.getNonVirtualSize().isZero() && !HasVtordisp) { |
| LazyEmptyBase = RD; |
| return; |
| } |
| |
| CharUnits BaseNVSize = Layout.getNonVirtualSize(); |
| CharUnits BaseAlign = Layout.getAlignment(); |
| |
| // vtordisps are always 4 bytes (even in 64-bit mode) |
| if (HasVtordisp) |
| Size = Size.RoundUpToAlignment(Alignment) + CharUnits::fromQuantity(4); |
| Size = Size.RoundUpToAlignment(BaseAlign); |
| |
| // Insert the base here. |
| CharUnits BaseOffset = Size.RoundUpToAlignment(BaseAlign); |
| VBases.insert( |
| std::make_pair(RD, ASTRecordLayout::VBaseInfo(BaseOffset, HasVtordisp))); |
| Size = BaseOffset + BaseNVSize; |
| // Note: we don't update alignment here because it was accounted for in |
| // InitializeLayout. |
| } |
| |
| void MicrosoftRecordLayoutBuilder::finalizeCXXLayout(const CXXRecordDecl *RD) { |
| // Flush the lazy virtual base. |
| layoutVirtualBase(0, false); |
| |
| if (RD->vbases_begin() == RD->vbases_end() || AlignAfterVBases) |
| Size = Size.RoundUpToAlignment(Alignment); |
| |
| if (Size.isZero()) |
| Size = Alignment; |
| } |
| |
| void MicrosoftRecordLayoutBuilder::honorDeclspecAlign(const RecordDecl *RD) { |
| if (unsigned MaxAlign = RD->getMaxAlignment()) { |
| AlignAfterVBases = true; |
| updateAlignment(Context.toCharUnitsFromBits(MaxAlign)); |
| Size = Size.RoundUpToAlignment(Alignment); |
| } |
| } |
| |
| static bool |
| RequiresVtordisp(const llvm::SmallPtrSet<const CXXRecordDecl *, 2> &HasVtordisp, |
| const CXXRecordDecl *RD) { |
| if (HasVtordisp.count(RD)) |
| return true; |
| // If any of a virtual bases non-virtual bases (recursively) requires a |
| // vtordisp than so does this virtual base. |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); |
| i != e; ++i) |
| if (!i->isVirtual() && |
| RequiresVtordisp( |
| HasVtordisp, |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()))) |
| return true; |
| return false; |
| } |
| |
| llvm::SmallPtrSet<const CXXRecordDecl *, 2> |
| MicrosoftRecordLayoutBuilder::computeVtorDispSet(const CXXRecordDecl *RD) { |
| llvm::SmallPtrSet<const CXXRecordDecl *, 2> HasVtordisp; |
| |
| // If any of our bases need a vtordisp for this type, so do we. Check our |
| // direct bases for vtordisp requirements. |
| for (CXXRecordDecl::base_class_const_iterator i = RD->bases_begin(), |
| e = RD->bases_end(); |
| i != e; ++i) { |
| const CXXRecordDecl *BaseDecl = |
| cast<CXXRecordDecl>(i->getType()->getAs<RecordType>()->getDecl()); |
| const ASTRecordLayout &Layout = Context.getASTRecordLayout(BaseDecl); |
| for (ASTRecordLayout::VBaseOffsetsMapTy::const_iterator |
| bi = Layout.getVBaseOffsetsMap().begin(), |
| be = Layout.getVBaseOffsetsMap().end(); |
| bi != be; ++bi) |
| if (bi->second.hasVtorDisp()) |
| HasVtordisp.insert(bi->first); |
| } |
| |
| // If we define a constructor or destructor and override a function that is |
| // defined in a virtual base's vtable, that virtual bases need a vtordisp. |
| // Here we collect a list of classes with vtables for which our virtual bases |
| // actually live. The virtual bases with this property will require |
| // vtordisps. In addition, virtual bases that contain non-virtual bases that |
| // define functions we override also require vtordisps, this case is checked |
| // explicitly below. |
| if (RD->hasUserDeclaredConstructor() || RD->hasUserDeclaredDestructor()) { |
| llvm::SmallPtrSet<const CXXMethodDecl *, 8> Work; |
| // Seed the working set with our non-destructor virtual methods. |
| for (CXXRecordDecl::method_iterator i = RD->method_begin(), |
| e = RD->method_end(); |
| i != e; ++i) |
| if ((*i)->isVirtual() && !isa<CXXDestructorDecl>(*i)) |
| Work.insert(*i); |
| while (!Work.empty()) { |
| const CXXMethodDecl *MD = *Work.begin(); |
| CXXMethodDecl::method_iterator i = MD->begin_overridden_methods(), |
| e = MD->end_overridden_methods(); |
| if (i == e) |
| // If a virtual method has no-overrides it lives in its parent's vtable. |
| HasVtordisp.insert(MD->getParent()); |
| else |
| Work.insert(i, e); |
| // We've finished processing this element, remove it from the working set. |
| Work.erase(MD); |
| } |
| } |
| |
| // Re-check all of our vbases for vtordisp requirements (in case their |
| // non-virtual bases have vtordisp requirements). |
| for (CXXRecordDecl::base_class_const_iterator i = RD->vbases_begin(), |
| e = RD->vbases_end(); |
| i != e; ++i) { |
| const CXXRecordDecl *BaseDecl = i->getType()->getAsCXXRecordDecl(); |
| if (!HasVtordisp.count(BaseDecl) && RequiresVtordisp(HasVtordisp, BaseDecl)) |
| HasVtordisp.insert(BaseDecl); |
| } |
| |
| return HasVtordisp; |
| } |
| |
| /// \brief Get or compute information about the layout of the specified record |
| /// (struct/union/class), which indicates its size and field position |
| /// information. |
| const ASTRecordLayout * |
| ASTContext::BuildMicrosoftASTRecordLayout(const RecordDecl *D) const { |
| MicrosoftRecordLayoutBuilder Builder(*this); |
| if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) { |
| Builder.cxxLayout(RD); |
| return new (*this) ASTRecordLayout( |
| *this, Builder.Size, Builder.Alignment, |
| Builder.HasVFPtr && !Builder.PrimaryBase, Builder.HasVFPtr, |
| Builder.HasVBPtr && !Builder.SharedVBPtrBase, Builder.VBPtrOffset, |
| Builder.DataSize, Builder.FieldOffsets.data(), |
| Builder.FieldOffsets.size(), Builder.DataSize, |
| Builder.NonVirtualAlignment, CharUnits::Zero(), Builder.PrimaryBase, |
| false, Builder.AlignAfterVBases, Builder.Bases, Builder.VBases); |
| } else { |
| Builder.layout(D); |
| return new (*this) ASTRecordLayout( |
| *this, Builder.Size, Builder.Alignment, Builder.Size, |
| Builder.FieldOffsets.data(), Builder.FieldOffsets.size()); |
| } |
| } |
| |
| /// getASTRecordLayout - Get or compute information about the layout of the |
| /// specified record (struct/union/class), which indicates its size and field |
| /// position information. |
| const ASTRecordLayout & |
| ASTContext::getASTRecordLayout(const RecordDecl *D) const { |
| // These asserts test different things. A record has a definition |
| // as soon as we begin to parse the definition. That definition is |
| // not a complete definition (which is what isDefinition() tests) |
| // until we *finish* parsing the definition. |
| |
| if (D->hasExternalLexicalStorage() && !D->getDefinition()) |
| getExternalSource()->CompleteType(const_cast<RecordDecl*>(D)); |
| |
| D = D->getDefinition(); |
| assert(D && "Cannot get layout of forward declarations!"); |
| assert(!D->isInvalidDecl() && "Cannot get layout of invalid decl!"); |
| assert(D->isCompleteDefinition() && "Cannot layout type before complete!"); |
| |
| // Look up this layout, if already laid out, return what we have. |
| // Note that we can't save a reference to the entry because this function |
| // is recursive. |
| const ASTRecordLayout *Entry = ASTRecordLayouts[D]; |
| if (Entry) return *Entry; |
| |
| const ASTRecordLayout *NewEntry = 0; |
| |
| if (isMsLayout(D) && !D->getASTContext().getExternalSource()) { |
| NewEntry = BuildMicrosoftASTRecordLayout(D); |
| } else if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) { |
| EmptySubobjectMap EmptySubobjects(*this, RD); |
| RecordLayoutBuilder Builder(*this, &EmptySubobjects); |
| Builder.Layout(RD); |
| |
| // In certain situations, we are allowed to lay out objects in the |
| // tail-padding of base classes. This is ABI-dependent. |
| // FIXME: this should be stored in the record layout. |
| bool skipTailPadding = |
| mustSkipTailPadding(getTargetInfo().getCXXABI(), cast<CXXRecordDecl>(D)); |
| |
| // FIXME: This should be done in FinalizeLayout. |
| CharUnits DataSize = |
| skipTailPadding ? Builder.getSize() : Builder.getDataSize(); |
| CharUnits NonVirtualSize = |
| skipTailPadding ? DataSize : Builder.NonVirtualSize; |
| NewEntry = |
| new (*this) ASTRecordLayout(*this, Builder.getSize(), |
| Builder.Alignment, |
| Builder.HasOwnVFPtr, |
| RD->isDynamicClass(), |
| false, |
| CharUnits::fromQuantity(-1), |
| DataSize, |
| Builder.FieldOffsets.data(), |
| Builder.FieldOffsets.size(), |
| NonVirtualSize, |
| Builder.NonVirtualAlignment, |
| EmptySubobjects.SizeOfLargestEmptySubobject, |
| Builder.PrimaryBase, |
| Builder.PrimaryBaseIsVirtual, |
| true, |
| Builder.Bases, Builder.VBases); |
| } else { |
| RecordLayoutBuilder Builder(*this, /*EmptySubobjects=*/0); |
| Builder.Layout(D); |
| |
| NewEntry = |
| new (*this) ASTRecordLayout(*this, Builder.getSize(), |
| Builder.Alignment, |
| Builder.getSize(), |
| Builder.FieldOffsets.data(), |
| Builder.FieldOffsets.size()); |
| } |
| |
| ASTRecordLayouts[D] = NewEntry; |
| |
| if (getLangOpts().DumpRecordLayouts) { |
| llvm::outs() << "\n*** Dumping AST Record Layout\n"; |
| DumpRecordLayout(D, llvm::outs(), getLangOpts().DumpRecordLayoutsSimple); |
| } |
| |
| return *NewEntry; |
| } |
| |
| const CXXMethodDecl *ASTContext::getCurrentKeyFunction(const CXXRecordDecl *RD) { |
| if (!getTargetInfo().getCXXABI().hasKeyFunctions()) |
| return 0; |
| |
| assert(RD->getDefinition() && "Cannot get key function for forward decl!"); |
| RD = cast<CXXRecordDecl>(RD->getDefinition()); |
| |
| LazyDeclPtr &Entry = KeyFunctions[RD]; |
| if (!Entry) |
| Entry = const_cast<CXXMethodDecl*>(computeKeyFunction(*this, RD)); |
| |
| return cast_or_null<CXXMethodDecl>(Entry.get(getExternalSource())); |
| } |
| |
| void ASTContext::setNonKeyFunction(const CXXMethodDecl *Method) { |
| assert(Method == Method->getFirstDecl() && |
| "not working with method declaration from class definition"); |
| |
| // Look up the cache entry. Since we're working with the first |
| // declaration, its parent must be the class definition, which is |
| // the correct key for the KeyFunctions hash. |
| llvm::DenseMap<const CXXRecordDecl*, LazyDeclPtr>::iterator |
| I = KeyFunctions.find(Method->getParent()); |
| |
| // If it's not cached, there's nothing to do. |
| if (I == KeyFunctions.end()) return; |
| |
| // If it is cached, check whether it's the target method, and if so, |
| // remove it from the cache. |
| if (I->second.get(getExternalSource()) == Method) { |
| // FIXME: remember that we did this for module / chained PCH state? |
| KeyFunctions.erase(I); |
| } |
| } |
| |
| static uint64_t getFieldOffset(const ASTContext &C, const FieldDecl *FD) { |
| const ASTRecordLayout &Layout = C.getASTRecordLayout(FD->getParent()); |
| return Layout.getFieldOffset(FD->getFieldIndex()); |
| } |
| |
| uint64_t ASTContext::getFieldOffset(const ValueDecl *VD) const { |
| uint64_t OffsetInBits; |
| if (const FieldDecl *FD = dyn_cast<FieldDecl>(VD)) { |
| OffsetInBits = ::getFieldOffset(*this, FD); |
| } else { |
| const IndirectFieldDecl *IFD = cast<IndirectFieldDecl>(VD); |
| |
| OffsetInBits = 0; |
| for (IndirectFieldDecl::chain_iterator CI = IFD->chain_begin(), |
| CE = IFD->chain_end(); |
| CI != CE; ++CI) |
| OffsetInBits += ::getFieldOffset(*this, cast<FieldDecl>(*CI)); |
| } |
| |
| return OffsetInBits; |
| } |
| |
| /// getObjCLayout - Get or compute information about the layout of the |
| /// given interface. |
| /// |
| /// \param Impl - If given, also include the layout of the interface's |
| /// implementation. This may differ by including synthesized ivars. |
| const ASTRecordLayout & |
| ASTContext::getObjCLayout(const ObjCInterfaceDecl *D, |
| const ObjCImplementationDecl *Impl) const { |
| // Retrieve the definition |
| if (D->hasExternalLexicalStorage() && !D->getDefinition()) |
| getExternalSource()->CompleteType(const_cast<ObjCInterfaceDecl*>(D)); |
| D = D->getDefinition(); |
| assert(D && D->isThisDeclarationADefinition() && "Invalid interface decl!"); |
| |
| // Look up this layout, if already laid out, return what we have. |
| const ObjCContainerDecl *Key = |
| Impl ? (const ObjCContainerDecl*) Impl : (const ObjCContainerDecl*) D; |
| if (const ASTRecordLayout *Entry = ObjCLayouts[Key]) |
| return *Entry; |
| |
| // Add in synthesized ivar count if laying out an implementation. |
| if (Impl) { |
| unsigned SynthCount = CountNonClassIvars(D); |
| // If there aren't any sythesized ivars then reuse the interface |
| // entry. Note we can't cache this because we simply free all |
| // entries later; however we shouldn't look up implementations |
| // frequently. |
| if (SynthCount == 0) |
| return getObjCLayout(D, 0); |
| } |
| |
| RecordLayoutBuilder Builder(*this, /*EmptySubobjects=*/0); |
| Builder.Layout(D); |
| |
| const ASTRecordLayout *NewEntry = |
| new (*this) ASTRecordLayout(*this, Builder.getSize(), |
| Builder.Alignment, |
| Builder.getDataSize(), |
| Builder.FieldOffsets.data(), |
| Builder.FieldOffsets.size()); |
| |
| ObjCLayouts[Key] = NewEntry; |
| |
| return *NewEntry; |
| } |
| |
| static void PrintOffset(raw_ostream &OS, |
| CharUnits Offset, unsigned IndentLevel) { |
| OS << llvm::format("%4" PRId64 " | ", (int64_t)Offset.getQuantity()); |
| OS.indent(IndentLevel * 2); |
| } |
| |
| static void PrintIndentNoOffset(raw_ostream &OS, unsigned IndentLevel) { |
| OS << " | "; |
| OS.indent(IndentLevel * 2); |
| } |
| |
| static void DumpCXXRecordLayout(raw_ostream &OS, |
| const CXXRecordDecl *RD, const ASTContext &C, |
| CharUnits Offset, |
| unsigned IndentLevel, |
| const char* Description, |
| bool IncludeVirtualBases) { |
| const ASTRecordLayout &Layout = C.getASTRecordLayout(RD); |
| |
| PrintOffset(OS, Offset, IndentLevel); |
| OS << C.getTypeDeclType(const_cast<CXXRecordDecl *>(RD)).getAsString(); |
| if (Description) |
| OS << ' ' << Description; |
| if (RD->isEmpty()) |
| OS << " (empty)"; |
| OS << '\n'; |
| |
| IndentLevel++; |
| |
| const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); |
| bool HasOwnVFPtr = Layout.hasOwnVFPtr(); |
| bool HasOwnVBPtr = Layout.hasOwnVBPtr(); |
| |
| // Vtable pointer. |
| if (RD->isDynamicClass() && !PrimaryBase && !isMsLayout(RD)) { |
| PrintOffset(OS, Offset, IndentLevel); |
| OS << '(' << *RD << " vtable pointer)\n"; |
| } else if (HasOwnVFPtr) { |
| PrintOffset(OS, Offset, IndentLevel); |
| // vfptr (for Microsoft C++ ABI) |
| OS << '(' << *RD << " vftable pointer)\n"; |
| } |
| |
| // Dump (non-virtual) bases |
| for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(), |
| E = RD->bases_end(); I != E; ++I) { |
| assert(!I->getType()->isDependentType() && |
| "Cannot layout class with dependent bases."); |
| if (I->isVirtual()) |
| continue; |
| |
| const CXXRecordDecl *Base = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| CharUnits BaseOffset = Offset + Layout.getBaseClassOffset(Base); |
| |
| DumpCXXRecordLayout(OS, Base, C, BaseOffset, IndentLevel, |
| Base == PrimaryBase ? "(primary base)" : "(base)", |
| /*IncludeVirtualBases=*/false); |
| } |
| |
| // vbptr (for Microsoft C++ ABI) |
| if (HasOwnVBPtr) { |
| PrintOffset(OS, Offset + Layout.getVBPtrOffset(), IndentLevel); |
| OS << '(' << *RD << " vbtable pointer)\n"; |
| } |
| |
| // Dump fields. |
| uint64_t FieldNo = 0; |
| for (CXXRecordDecl::field_iterator I = RD->field_begin(), |
| E = RD->field_end(); I != E; ++I, ++FieldNo) { |
| const FieldDecl &Field = **I; |
| CharUnits FieldOffset = Offset + |
| C.toCharUnitsFromBits(Layout.getFieldOffset(FieldNo)); |
| |
| if (const RecordType *RT = Field.getType()->getAs<RecordType>()) { |
| if (const CXXRecordDecl *D = dyn_cast<CXXRecordDecl>(RT->getDecl())) { |
| DumpCXXRecordLayout(OS, D, C, FieldOffset, IndentLevel, |
| Field.getName().data(), |
| /*IncludeVirtualBases=*/true); |
| continue; |
| } |
| } |
| |
| PrintOffset(OS, FieldOffset, IndentLevel); |
| OS << Field.getType().getAsString() << ' ' << Field << '\n'; |
| } |
| |
| if (!IncludeVirtualBases) |
| return; |
| |
| // Dump virtual bases. |
| const ASTRecordLayout::VBaseOffsetsMapTy &vtordisps = |
| Layout.getVBaseOffsetsMap(); |
| for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(), |
| E = RD->vbases_end(); I != E; ++I) { |
| assert(I->isVirtual() && "Found non-virtual class!"); |
| const CXXRecordDecl *VBase = |
| cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); |
| |
| CharUnits VBaseOffset = Offset + Layout.getVBaseClassOffset(VBase); |
| |
| if (vtordisps.find(VBase)->second.hasVtorDisp()) { |
| PrintOffset(OS, VBaseOffset - CharUnits::fromQuantity(4), IndentLevel); |
| OS << "(vtordisp for vbase " << *VBase << ")\n"; |
| } |
| |
| DumpCXXRecordLayout(OS, VBase, C, VBaseOffset, IndentLevel, |
| VBase == PrimaryBase ? |
| "(primary virtual base)" : "(virtual base)", |
| /*IncludeVirtualBases=*/false); |
| } |
| |
| PrintIndentNoOffset(OS, IndentLevel - 1); |
| OS << "[sizeof=" << Layout.getSize().getQuantity(); |
| if (!isMsLayout(RD)) |
| OS << ", dsize=" << Layout.getDataSize().getQuantity(); |
| OS << ", align=" << Layout.getAlignment().getQuantity() << '\n'; |
| |
| PrintIndentNoOffset(OS, IndentLevel - 1); |
| OS << " nvsize=" << Layout.getNonVirtualSize().getQuantity(); |
| OS << ", nvalign=" << Layout.getNonVirtualAlign().getQuantity() << "]\n"; |
| OS << '\n'; |
| } |
| |
| void ASTContext::DumpRecordLayout(const RecordDecl *RD, |
| raw_ostream &OS, |
| bool Simple) const { |
| const ASTRecordLayout &Info = getASTRecordLayout(RD); |
| |
| if (const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD)) |
| if (!Simple) |
| return DumpCXXRecordLayout(OS, CXXRD, *this, CharUnits(), 0, 0, |
| /*IncludeVirtualBases=*/true); |
| |
| OS << "Type: " << getTypeDeclType(RD).getAsString() << "\n"; |
| if (!Simple) { |
| OS << "Record: "; |
| RD->dump(); |
| } |
| OS << "\nLayout: "; |
| OS << "<ASTRecordLayout\n"; |
| OS << " Size:" << toBits(Info.getSize()) << "\n"; |
| if (!isMsLayout(RD)) |
| OS << " DataSize:" << toBits(Info.getDataSize()) << "\n"; |
| OS << " Alignment:" << toBits(Info.getAlignment()) << "\n"; |
| OS << " FieldOffsets: ["; |
| for (unsigned i = 0, e = Info.getFieldCount(); i != e; ++i) { |
| if (i) OS << ", "; |
| OS << Info.getFieldOffset(i); |
| } |
| OS << "]>\n"; |
| } |