diff options
Diffstat (limited to 'contrib/llvm/tools/clang/lib/AST/RecordLayoutBuilder.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/AST/RecordLayoutBuilder.cpp | 972 |
1 files changed, 562 insertions, 410 deletions
diff --git a/contrib/llvm/tools/clang/lib/AST/RecordLayoutBuilder.cpp b/contrib/llvm/tools/clang/lib/AST/RecordLayoutBuilder.cpp index 983a287..88d71ce 100644 --- a/contrib/llvm/tools/clang/lib/AST/RecordLayoutBuilder.cpp +++ b/contrib/llvm/tools/clang/lib/AST/RecordLayoutBuilder.cpp @@ -23,6 +23,35 @@ 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. + llvm::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 { @@ -36,30 +65,41 @@ class EmptySubobjectMap { typedef llvm::DenseMap<uint64_t, ClassVectorTy> EmptyClassOffsetsMapTy; EmptyClassOffsetsMapTy EmptyClassOffsets; + /// MaxEmptyClassOffset - The highest offset known to contain an empty + /// base subobject. + uint64_t MaxEmptyClassOffset; + /// ComputeEmptySubobjectSizes - Compute the size of the largest base or /// member subobject that is empty. void ComputeEmptySubobjectSizes(); + + bool CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD, + uint64_t Offset) const; - struct BaseInfo { - const CXXRecordDecl *Class; - bool IsVirtual; - - const CXXRecordDecl *PrimaryVirtualBase; - - llvm::SmallVector<BaseInfo*, 4> Bases; - const BaseInfo *Derived; - }; + void AddSubobjectAtOffset(const CXXRecordDecl *RD, uint64_t Offset); - llvm::DenseMap<const CXXRecordDecl *, BaseInfo *> VirtualBaseInfo; - llvm::DenseMap<const CXXRecordDecl *, BaseInfo *> NonVirtualBaseInfo; + bool CanPlaceBaseSubobjectAtOffset(const BaseSubobjectInfo *Info, + uint64_t Offset); + void UpdateEmptyBaseSubobjects(const BaseSubobjectInfo *Info, + uint64_t Offset, bool PlacingEmptyBase); - BaseInfo *ComputeBaseInfo(const CXXRecordDecl *RD, bool IsVirtual, - const BaseInfo *Derived); - void ComputeBaseInfo(); + bool CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD, + const CXXRecordDecl *Class, + uint64_t Offset) const; + bool CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD, + uint64_t Offset) const; - bool CanPlaceBaseSubobjectAtOffset(const BaseInfo *Info, uint64_t Offset); - void UpdateEmptyBaseSubobjects(const BaseInfo *Info, uint64_t Offset); + void UpdateEmptyFieldSubobjects(const CXXRecordDecl *RD, + const CXXRecordDecl *Class, + uint64_t Offset); + void UpdateEmptyFieldSubobjects(const FieldDecl *FD, uint64_t Offset); + /// AnyEmptySubobjectsBeyondOffset - Returns whether there are any empty + /// subobjects beyond the given offset. + bool AnyEmptySubobjectsBeyondOffset(uint64_t Offset) const { + return Offset <= MaxEmptyClassOffset; + } + 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 @@ -67,18 +107,21 @@ public: uint64_t SizeOfLargestEmptySubobject; EmptySubobjectMap(ASTContext &Context, const CXXRecordDecl *Class) - : Context(Context), Class(Class), SizeOfLargestEmptySubobject(0) { + : Context(Context), Class(Class), MaxEmptyClassOffset(0), + SizeOfLargestEmptySubobject(0) { ComputeEmptySubobjectSizes(); - - ComputeBaseInfo(); } /// 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 CXXRecordDecl *RD, bool BaseIsVirtual, + bool CanPlaceBaseAtOffset(const BaseSubobjectInfo *Info, uint64_t Offset); + + /// CanPlaceFieldAtOffset - Return whether a field can be placed at the given + /// offset. + bool CanPlaceFieldAtOffset(const FieldDecl *FD, uint64_t Offset); }; void EmptySubobjectMap::ComputeEmptySubobjectSizes() { @@ -130,93 +173,67 @@ void EmptySubobjectMap::ComputeEmptySubobjectSizes() { } } -EmptySubobjectMap::BaseInfo * -EmptySubobjectMap::ComputeBaseInfo(const CXXRecordDecl *RD, bool IsVirtual, - const BaseInfo *Derived) { - BaseInfo *Info; - - if (IsVirtual) { - BaseInfo *&InfoSlot = VirtualBaseInfo[RD]; - if (InfoSlot) { - assert(InfoSlot->Class == RD && "Wrong class for virtual base info!"); - return InfoSlot; - } +bool +EmptySubobjectMap::CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD, + uint64_t Offset) const { + // We only need to check empty bases. + if (!RD->isEmpty()) + return true; - InfoSlot = new (Context) BaseInfo; - Info = InfoSlot; - } else { - Info = new (Context) BaseInfo; - } - - Info->Class = RD; - Info->IsVirtual = IsVirtual; - Info->Derived = Derived; - Info->PrimaryVirtualBase = 0; + EmptyClassOffsetsMapTy::const_iterator I = EmptyClassOffsets.find(Offset); + if (I == EmptyClassOffsets.end()) + return true; - if (RD->getNumVBases()) { - // Check if this class has a primary virtual base. - const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); - if (Layout.getPrimaryBaseWasVirtual()) { - Info->PrimaryVirtualBase = Layout.getPrimaryBase(); - assert(Info->PrimaryVirtualBase && - "Didn't have a primary virtual base!"); - } - } + const ClassVectorTy& Classes = I->second; + if (std::find(Classes.begin(), Classes.end(), RD) == Classes.end()) + return true; - 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(ComputeBaseInfo(BaseDecl, IsVirtual, Info)); - } - - return Info; + // There is already an empty class of the same type at this offset. + return false; } + +void EmptySubobjectMap::AddSubobjectAtOffset(const CXXRecordDecl *RD, + uint64_t Offset) { + // We only care about empty bases. + if (!RD->isEmpty()) + return; -void EmptySubobjectMap::ComputeBaseInfo() { - for (CXXRecordDecl::base_class_const_iterator I = Class->bases_begin(), - E = Class->bases_end(); I != E; ++I) { - bool IsVirtual = I->isVirtual(); - - const CXXRecordDecl *BaseDecl = - cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); - - BaseInfo *Info = ComputeBaseInfo(BaseDecl, IsVirtual, /*Derived=*/0); - if (IsVirtual) { - // ComputeBaseInfo has already added this base for us. - continue; - } + ClassVectorTy& Classes = EmptyClassOffsets[Offset]; + assert(std::find(Classes.begin(), Classes.end(), RD) == Classes.end() && + "Duplicate empty class detected!"); - // 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)); - } + Classes.push_back(RD); + + // Update the empty class offset. + MaxEmptyClassOffset = std::max(MaxEmptyClassOffset, Offset); } bool -EmptySubobjectMap::CanPlaceBaseSubobjectAtOffset(const BaseInfo *Info, +EmptySubobjectMap::CanPlaceBaseSubobjectAtOffset(const BaseSubobjectInfo *Info, uint64_t 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) { - BaseInfo* Base = Info->Bases[I]; + BaseSubobjectInfo* Base = Info->Bases[I]; if (Base->IsVirtual) continue; - const ASTRecordLayout &Layout = Context.getASTRecordLayout(Info->Class); uint64_t BaseOffset = Offset + Layout.getBaseClassOffset(Base->Class); if (!CanPlaceBaseSubobjectAtOffset(Base, BaseOffset)) return false; } - if (Info->PrimaryVirtualBase) { - BaseInfo *PrimaryVirtualBaseInfo = - VirtualBaseInfo.lookup(Info->PrimaryVirtualBase); - assert(PrimaryVirtualBaseInfo && "Didn't find base info!"); + if (Info->PrimaryVirtualBaseInfo) { + BaseSubobjectInfo *PrimaryVirtualBaseInfo = Info->PrimaryVirtualBaseInfo; if (Info == PrimaryVirtualBaseInfo->Derived) { if (!CanPlaceBaseSubobjectAtOffset(PrimaryVirtualBaseInfo, Offset)) @@ -224,62 +241,277 @@ EmptySubobjectMap::CanPlaceBaseSubobjectAtOffset(const BaseInfo *Info, } } - // FIXME: Member variables. + // 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) { + const FieldDecl *FD = *I; + + uint64_t FieldOffset = Offset + Layout.getFieldOffset(FieldNo); + if (!CanPlaceFieldSubobjectAtOffset(FD, FieldOffset)) + return false; + } + return true; } -void EmptySubobjectMap::UpdateEmptyBaseSubobjects(const BaseInfo *Info, - uint64_t Offset) { - if (Info->Class->isEmpty()) { - // FIXME: Record that there is an empty class at this offset. +void EmptySubobjectMap::UpdateEmptyBaseSubobjects(const BaseSubobjectInfo *Info, + uint64_t 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) { - BaseInfo* Base = Info->Bases[I]; + BaseSubobjectInfo* Base = Info->Bases[I]; if (Base->IsVirtual) continue; - - const ASTRecordLayout &Layout = Context.getASTRecordLayout(Info->Class); + uint64_t BaseOffset = Offset + Layout.getBaseClassOffset(Base->Class); - - UpdateEmptyBaseSubobjects(Base, BaseOffset); + UpdateEmptyBaseSubobjects(Base, BaseOffset, PlacingEmptyBase); } - if (Info->PrimaryVirtualBase) { - BaseInfo *PrimaryVirtualBaseInfo = - VirtualBaseInfo.lookup(Info->PrimaryVirtualBase); - assert(PrimaryVirtualBaseInfo && "Didn't find base info!"); + if (Info->PrimaryVirtualBaseInfo) { + BaseSubobjectInfo *PrimaryVirtualBaseInfo = Info->PrimaryVirtualBaseInfo; if (Info == PrimaryVirtualBaseInfo->Derived) - UpdateEmptyBaseSubobjects(PrimaryVirtualBaseInfo, Offset); + 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) { + const FieldDecl *FD = *I; + + uint64_t FieldOffset = Offset + Layout.getFieldOffset(FieldNo); + UpdateEmptyFieldSubobjects(FD, FieldOffset); } - - // FIXME: Member variables. } -bool EmptySubobjectMap::CanPlaceBaseAtOffset(const CXXRecordDecl *RD, - bool BaseIsVirtual, +bool EmptySubobjectMap::CanPlaceBaseAtOffset(const BaseSubobjectInfo *Info, uint64_t Offset) { // If we know this class doesn't have any empty subobjects we don't need to // bother checking. if (!SizeOfLargestEmptySubobject) return true; - BaseInfo *Info; + 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, + uint64_t 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; - if (BaseIsVirtual) - Info = VirtualBaseInfo.lookup(RD); - else - Info = NonVirtualBaseInfo.lookup(RD); + 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()); + + uint64_t 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()); + + uint64_t 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) { + const FieldDecl *FD = *I; + + uint64_t FieldOffset = Offset + Layout.getFieldOffset(FieldNo); + + if (!CanPlaceFieldSubobjectAtOffset(FD, FieldOffset)) + return false; + } + + return true; +} + +bool EmptySubobjectMap::CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD, + uint64_t 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 (!CanPlaceBaseSubobjectAtOffset(Info, Offset)) + 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); + uint64_t 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, uint64_t Offset) { + if (!CanPlaceFieldSubobjectAtOffset(FD, Offset)) return false; - UpdateEmptyBaseSubobjects(Info, Offset); + // 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, + uint64_t 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()); + + uint64_t 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()); + + uint64_t 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) { + const FieldDecl *FD = *I; + + uint64_t FieldOffset = Offset + Layout.getFieldOffset(FieldNo); + + UpdateEmptyFieldSubobjects(FD, FieldOffset); + } +} + +void EmptySubobjectMap::UpdateEmptyFieldSubobjects(const FieldDecl *FD, + uint64_t 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); + uint64_t 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(); + } + } +} + class RecordLayoutBuilder { // FIXME: Remove this and make the appropriate fields public. friend class clang::ASTContext; @@ -346,10 +578,6 @@ class RecordLayoutBuilder { /// avoid visiting virtual bases more than once. llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBases; - /// EmptyClassOffsets - A map from offsets to empty record decls. - typedef std::multimap<uint64_t, const CXXRecordDecl *> EmptyClassOffsetsTy; - EmptyClassOffsetsTy EmptyClassOffsets; - RecordLayoutBuilder(ASTContext &Context, EmptySubobjectMap *EmptySubobjects) : Context(Context), EmptySubobjects(EmptySubobjects), Size(0), Alignment(8), Packed(false), IsUnion(false), IsMac68kAlign(false), @@ -366,9 +594,29 @@ class RecordLayoutBuilder { void LayoutWideBitField(uint64_t FieldSize, uint64_t TypeSize); void LayoutBitField(const FieldDecl *D); - /// ComputeEmptySubobjectSizes - Compute the size of the largest base or - /// member subobject that is empty. - void ComputeEmptySubobjectSizes(const CXXRecordDecl *RD); + /// 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); @@ -387,43 +635,21 @@ class RecordLayoutBuilder { void LayoutNonVirtualBases(const CXXRecordDecl *RD); /// LayoutNonVirtualBase - Lays out a single non-virtual base. - void LayoutNonVirtualBase(const CXXRecordDecl *Base); + void LayoutNonVirtualBase(const BaseSubobjectInfo *Base); - void AddPrimaryVirtualBaseOffsets(const CXXRecordDecl *RD, uint64_t Offset, - const CXXRecordDecl *MostDerivedClass); + void AddPrimaryVirtualBaseOffsets(const BaseSubobjectInfo *Info, + uint64_t 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 CXXRecordDecl *Base); + void LayoutVirtualBase(const BaseSubobjectInfo *Base); /// LayoutBase - Will lay out a base and return the offset where it was /// placed, in bits. - uint64_t LayoutBase(const CXXRecordDecl *Base, bool BaseIsVirtual); - - /// canPlaceRecordAtOffset - Return whether a record (either a base class - /// or a field) 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 canPlaceRecordAtOffset(const CXXRecordDecl *RD, uint64_t Offset, - bool CheckVBases) const; - - /// canPlaceFieldAtOffset - Return whether a field can be placed at the given - /// offset. - bool canPlaceFieldAtOffset(const FieldDecl *FD, uint64_t Offset) const; - - /// UpdateEmptyClassOffsets - Called after a record (either a base class - /// or a field) has been placed at the given offset. Will update the - /// EmptyClassOffsets map if the class is empty or has any empty bases or - /// fields. - void UpdateEmptyClassOffsets(const CXXRecordDecl *RD, uint64_t Offset, - bool UpdateVBases); - - /// UpdateEmptyClassOffsets - Called after a field has been placed at the - /// given offset. - void UpdateEmptyClassOffsets(const FieldDecl *FD, uint64_t Offset); + uint64_t LayoutBase(const BaseSubobjectInfo *Base); /// InitializeLayout - Initialize record layout for the given record decl. void InitializeLayout(const Decl *D); @@ -575,14 +801,127 @@ void RecordLayoutBuilder::DeterminePrimaryBase(const CXXRecordDecl *RD) { UpdateAlignment(Context.Target.getPointerAlign(0)); } +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.getPrimaryBaseWasVirtual()) { + // 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::LayoutNonVirtualBases(const CXXRecordDecl *RD) { - // First, determine the primary base class. + // 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); @@ -590,9 +929,15 @@ RecordLayoutBuilder::LayoutNonVirtualBases(const CXXRecordDecl *RD) { "vbase already visited!"); VisitedVirtualBases.insert(PrimaryBase); - LayoutVirtualBase(PrimaryBase); - } else - LayoutNonVirtualBase(PrimaryBase); + LayoutVirtualBase(PrimaryBaseInfo); + } else { + BaseSubobjectInfo *PrimaryBaseInfo = + NonVirtualBaseInfo.lookup(PrimaryBase); + assert(PrimaryBaseInfo && + "Did not find base info for non-virtual primary base!"); + + LayoutNonVirtualBase(PrimaryBaseInfo); + } } // Now lay out the non-virtual bases. @@ -603,81 +948,64 @@ RecordLayoutBuilder::LayoutNonVirtualBases(const CXXRecordDecl *RD) { if (I->isVirtual()) continue; - const CXXRecordDecl *Base = + const CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); // Skip the primary base. - if (Base == PrimaryBase && !PrimaryBaseIsVirtual) + if (BaseDecl == PrimaryBase && !PrimaryBaseIsVirtual) continue; // Lay out the base. - LayoutNonVirtualBase(Base); + BaseSubobjectInfo *BaseInfo = NonVirtualBaseInfo.lookup(BaseDecl); + assert(BaseInfo && "Did not find base info for non-virtual base!"); + + LayoutNonVirtualBase(BaseInfo); } } -void RecordLayoutBuilder::LayoutNonVirtualBase(const CXXRecordDecl *Base) { +void RecordLayoutBuilder::LayoutNonVirtualBase(const BaseSubobjectInfo *Base) { // Layout the base. - uint64_t Offset = LayoutBase(Base, /*BaseIsVirtual=*/false); + uint64_t Offset = LayoutBase(Base); // Add its base class offset. - if (!Bases.insert(std::make_pair(Base, Offset)).second) - assert(false && "Added same base offset more than once!"); + assert(!Bases.count(Base->Class) && "base offset already exists!"); + Bases.insert(std::make_pair(Base->Class, Offset)); + + AddPrimaryVirtualBaseOffsets(Base, Offset); } void -RecordLayoutBuilder::AddPrimaryVirtualBaseOffsets(const CXXRecordDecl *RD, - uint64_t Offset, - const CXXRecordDecl *MostDerivedClass) { - // We already have the offset for the primary base of the most derived class. - if (RD != MostDerivedClass) { - const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); - const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); - - // If this is a primary virtual base and we haven't seen it before, add it. - if (PrimaryBase && Layout.getPrimaryBaseWasVirtual() && - !VBases.count(PrimaryBase)) - VBases.insert(std::make_pair(PrimaryBase, Offset)); +RecordLayoutBuilder::AddPrimaryVirtualBaseOffsets(const BaseSubobjectInfo *Info, + uint64_t 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, + Offset)); + + // Traverse the primary virtual base. + AddPrimaryVirtualBaseOffsets(Info->PrimaryVirtualBaseInfo, Offset); + } } - 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()->getAs<RecordType>()->getDecl()); - - if (!BaseDecl->getNumVBases()) { - // This base isn't interesting since it doesn't have any virtual bases. + // 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; - } - - // Compute the offset of this base. - uint64_t BaseOffset; - - if (I->isVirtual()) { - // If we don't know this vbase yet, don't visit it. It will be visited - // later. - if (!VBases.count(BaseDecl)) { - continue; - } - - // Check if we've already visited this base. - if (!VisitedVirtualBases.insert(BaseDecl)) - continue; - // We want the vbase offset from the class we're currently laying out. - BaseOffset = VBases[BaseDecl]; - } else if (RD == MostDerivedClass) { - // We want the base offset from the class we're currently laying out. - assert(Bases.count(BaseDecl) && "Did not find base!"); - BaseOffset = Bases[BaseDecl]; - } else { - const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); - BaseOffset = Offset + Layout.getBaseClassOffset(BaseDecl); - } - - AddPrimaryVirtualBaseOffsets(BaseDecl, BaseOffset, MostDerivedClass); + uint64_t BaseOffset = Offset + Layout.getBaseClassOffset(Base->Class); + AddPrimaryVirtualBaseOffsets(Base, BaseOffset); } } @@ -701,53 +1029,54 @@ RecordLayoutBuilder::LayoutVirtualBases(const CXXRecordDecl *RD, assert(!I->getType()->isDependentType() && "Cannot layout class with dependent bases."); - const CXXRecordDecl *Base = + const CXXRecordDecl *BaseDecl = cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); if (I->isVirtual()) { - if (PrimaryBase != Base || !PrimaryBaseIsVirtual) { - bool IndirectPrimaryBase = IndirectPrimaryBases.count(Base); + 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(Base)) + if (!VisitedVirtualBases.insert(BaseDecl)) continue; - LayoutVirtualBase(Base); + const BaseSubobjectInfo *BaseInfo = VirtualBaseInfo.lookup(BaseDecl); + assert(BaseInfo && "Did not find virtual base info!"); + LayoutVirtualBase(BaseInfo); } } } - if (!Base->getNumVBases()) { + if (!BaseDecl->getNumVBases()) { // This base isn't interesting since it doesn't have any virtual bases. continue; } - LayoutVirtualBases(Base, MostDerivedClass); + LayoutVirtualBases(BaseDecl, MostDerivedClass); } } -void RecordLayoutBuilder::LayoutVirtualBase(const CXXRecordDecl *Base) { +void RecordLayoutBuilder::LayoutVirtualBase(const BaseSubobjectInfo *Base) { + assert(!Base->Derived && "Trying to lay out a primary virtual base!"); + // Layout the base. - uint64_t Offset = LayoutBase(Base, /*BaseIsVirtual=*/true); + uint64_t Offset = LayoutBase(Base); // Add its base class offset. - if (!VBases.insert(std::make_pair(Base, Offset)).second) - assert(false && "Added same vbase offset more than once!"); + assert(!VBases.count(Base->Class) && "vbase offset already exists!"); + VBases.insert(std::make_pair(Base->Class, Offset)); + + AddPrimaryVirtualBaseOffsets(Base, Offset); } -uint64_t RecordLayoutBuilder::LayoutBase(const CXXRecordDecl *Base, - bool BaseIsVirtual) { - const ASTRecordLayout &Layout = Context.getASTRecordLayout(Base); +uint64_t RecordLayoutBuilder::LayoutBase(const BaseSubobjectInfo *Base) { + const ASTRecordLayout &Layout = Context.getASTRecordLayout(Base->Class); // If we have an empty base class, try to place it at offset 0. - if (Base->isEmpty() && - EmptySubobjects->CanPlaceBaseAtOffset(Base, BaseIsVirtual, 0) && - canPlaceRecordAtOffset(Base, 0, /*CheckVBases=*/false)) { - // We were able to place the class at offset 0. - UpdateEmptyClassOffsets(Base, 0, /*UpdateVBases=*/false); - + if (Base->Class->isEmpty() && + EmptySubobjects->CanPlaceBaseAtOffset(Base, 0)) { Size = std::max(Size, Layout.getSize()); return 0; @@ -759,15 +1088,10 @@ uint64_t RecordLayoutBuilder::LayoutBase(const CXXRecordDecl *Base, uint64_t Offset = llvm::RoundUpToAlignment(DataSize, BaseAlign); // Try to place the base. - while (true) { - if (EmptySubobjects->CanPlaceBaseAtOffset(Base, BaseIsVirtual, Offset) && - canPlaceRecordAtOffset(Base, Offset, /*CheckVBases=*/false)) - break; - + while (!EmptySubobjects->CanPlaceBaseAtOffset(Base, Offset)) Offset += BaseAlign; - } - if (!Base->isEmpty()) { + if (!Base->Class->isEmpty()) { // Update the data size. DataSize = Offset + Layout.getNonVirtualSize(); @@ -778,173 +1102,9 @@ uint64_t RecordLayoutBuilder::LayoutBase(const CXXRecordDecl *Base, // Remember max struct/class alignment. UpdateAlignment(BaseAlign); - UpdateEmptyClassOffsets(Base, Offset, /*UpdateVBases=*/false); return Offset; } -bool -RecordLayoutBuilder::canPlaceRecordAtOffset(const CXXRecordDecl *RD, - uint64_t Offset, - bool CheckVBases) const { - // Look for an empty class with the same type at the same offset. - for (EmptyClassOffsetsTy::const_iterator I = - EmptyClassOffsets.lower_bound(Offset), - E = EmptyClassOffsets.upper_bound(Offset); I != E; ++I) { - - if (I->second == RD) - return false; - } - - const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); - - // Check 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 *BaseDecl = - cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl()); - - uint64_t BaseOffset = Layout.getBaseClassOffset(BaseDecl); - - if (!canPlaceRecordAtOffset(BaseDecl, Offset + BaseOffset, - /*CheckVBases=*/false)) - return false; - } - - // Check fields. - unsigned FieldNo = 0; - for (CXXRecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end(); - I != E; ++I, ++FieldNo) { - const FieldDecl *FD = *I; - - uint64_t FieldOffset = Layout.getFieldOffset(FieldNo); - - if (!canPlaceFieldAtOffset(FD, Offset + FieldOffset)) - return false; - } - - if (CheckVBases) { - // FIXME: virtual bases. - } - - return true; -} - -bool RecordLayoutBuilder::canPlaceFieldAtOffset(const FieldDecl *FD, - uint64_t Offset) const { - QualType T = FD->getType(); - if (const RecordType *RT = T->getAs<RecordType>()) { - if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) - return canPlaceRecordAtOffset(RD, Offset, /*CheckVBases=*/true); - } - - 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 = dyn_cast<CXXRecordDecl>(RT->getDecl()); - if (!RD) - return true; - - const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); - - uint64_t NumElements = Context.getConstantArrayElementCount(AT); - uint64_t ElementOffset = Offset; - for (uint64_t I = 0; I != NumElements; ++I) { - if (!canPlaceRecordAtOffset(RD, ElementOffset, /*CheckVBases=*/true)) - return false; - - ElementOffset += Layout.getSize(); - } - } - - return true; -} - -void RecordLayoutBuilder::UpdateEmptyClassOffsets(const CXXRecordDecl *RD, - uint64_t Offset, - bool UpdateVBases) { - if (RD->isEmpty()) - EmptyClassOffsets.insert(std::make_pair(Offset, RD)); - - const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); - - // Update 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()); - - uint64_t BaseClassOffset = Layout.getBaseClassOffset(Base); - UpdateEmptyClassOffsets(Base, Offset + BaseClassOffset, - /*UpdateVBases=*/false); - } - - // Update fields. - unsigned FieldNo = 0; - for (CXXRecordDecl::field_iterator I = RD->field_begin(), E = RD->field_end(); - I != E; ++I, ++FieldNo) { - const FieldDecl *FD = *I; - - uint64_t FieldOffset = Layout.getFieldOffset(FieldNo); - UpdateEmptyClassOffsets(FD, Offset + FieldOffset); - } - - const CXXRecordDecl *PrimaryBase = Layout.getPrimaryBase(); - - if (UpdateVBases) { - // FIXME: Update virtual bases. - } else if (PrimaryBase && Layout.getPrimaryBaseWasVirtual()) { - // We always want to update the offsets of a primary virtual base. - assert(Layout.getVBaseClassOffset(PrimaryBase) == 0 && - "primary base class offset must always be 0!"); - UpdateEmptyClassOffsets(PrimaryBase, Offset, /*UpdateVBases=*/false); - } -} - -void -RecordLayoutBuilder::UpdateEmptyClassOffsets(const FieldDecl *FD, - uint64_t Offset) { - QualType T = FD->getType(); - - if (const RecordType *RT = T->getAs<RecordType>()) { - if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) { - UpdateEmptyClassOffsets(RD, Offset, /*UpdateVBases=*/true); - return; - } - } - - if (const ConstantArrayType *AT = Context.getAsConstantArrayType(T)) { - QualType ElemTy = Context.getBaseElementType(AT); - const RecordType *RT = ElemTy->getAs<RecordType>(); - if (!RT) - return; - const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()); - if (!RD) - return; - - const ASTRecordLayout &Info = Context.getASTRecordLayout(RD); - - uint64_t NumElements = Context.getConstantArrayElementCount(AT); - uint64_t ElementOffset = Offset; - - for (uint64_t I = 0; I != NumElements; ++I) { - UpdateEmptyClassOffsets(RD, ElementOffset, /*UpdateVBases=*/true); - ElementOffset += Info.getSize(); - } - } -} - void RecordLayoutBuilder::InitializeLayout(const Decl *D) { if (const RecordDecl *RD = dyn_cast<RecordDecl>(D)) IsUnion = RD->isUnion(); @@ -992,7 +1152,6 @@ void RecordLayoutBuilder::Layout(const CXXRecordDecl *RD) { LayoutVirtualBases(RD, RD); VisitedVirtualBases.clear(); - AddPrimaryVirtualBaseOffsets(RD, 0, RD); // Finally, round the size of the total struct up to the alignment of the // struct itself. @@ -1137,7 +1296,7 @@ void RecordLayoutBuilder::LayoutBitField(const FieldDecl *D) { // Check if we need to add padding to give the field the correct alignment. if (FieldSize == 0 || (FieldOffset & (FieldAlign-1)) + FieldSize > TypeSize) - FieldOffset = (FieldOffset + (FieldAlign-1)) & ~(FieldAlign-1); + FieldOffset = llvm::RoundUpToAlignment(FieldOffset, FieldAlign); // Padding members don't affect overall alignment. if (!D->getIdentifier()) @@ -1208,17 +1367,12 @@ void RecordLayoutBuilder::LayoutField(const FieldDecl *D) { // Round up the current record size to the field's alignment boundary. FieldOffset = llvm::RoundUpToAlignment(FieldOffset, FieldAlign); - if (!IsUnion) { - while (true) { - // Check if we can place the field at this offset. - if (canPlaceFieldAtOffset(D, FieldOffset)) - break; - + 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; } - - UpdateEmptyClassOffsets(D, FieldOffset); } // Place this field at the current location. @@ -1261,8 +1415,6 @@ void RecordLayoutBuilder::UpdateAlignment(unsigned NewAlignment) { const CXXMethodDecl * RecordLayoutBuilder::ComputeKeyFunction(const CXXRecordDecl *RD) { - assert(RD->isDynamicClass() && "Class does not have any virtual methods!"); - // If a class isn't polymorphic it doesn't have a key function. if (!RD->isPolymorphic()) return 0; |
