diff options
| -rw-r--r-- | lib/AST/RecordLayoutBuilder.cpp | 98 |
1 files changed, 73 insertions, 25 deletions
diff --git a/lib/AST/RecordLayoutBuilder.cpp b/lib/AST/RecordLayoutBuilder.cpp index f42ba5a29f..c1cb98b96b 100644 --- a/lib/AST/RecordLayoutBuilder.cpp +++ b/lib/AST/RecordLayoutBuilder.cpp @@ -73,22 +73,11 @@ class EmptySubobjectMap { /// member subobject that is empty. void ComputeEmptySubobjectSizes(); - bool CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD, - uint64_t Offset) const; - void AddSubobjectAtOffset(const CXXRecordDecl *RD, uint64_t Offset); - bool CanPlaceBaseSubobjectAtOffset(const BaseSubobjectInfo *Info, - uint64_t Offset); void UpdateEmptyBaseSubobjects(const BaseSubobjectInfo *Info, uint64_t Offset, bool PlacingEmptyBase); - bool CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD, - const CXXRecordDecl *Class, - uint64_t Offset) const; - bool CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD, - uint64_t Offset) const; - void UpdateEmptyFieldSubobjects(const CXXRecordDecl *RD, const CXXRecordDecl *Class, uint64_t Offset); @@ -100,6 +89,19 @@ class EmptySubobjectMap { return Offset <= MaxEmptyClassOffset; } +protected: + bool CanPlaceSubobjectAtOffset(const CXXRecordDecl *RD, + uint64_t Offset) const; + + bool CanPlaceBaseSubobjectAtOffset(const BaseSubobjectInfo *Info, + uint64_t Offset); + + bool CanPlaceFieldSubobjectAtOffset(const CXXRecordDecl *RD, + const CXXRecordDecl *Class, + uint64_t Offset) const; + bool CanPlaceFieldSubobjectAtOffset(const FieldDecl *FD, + uint64_t 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 @@ -513,6 +515,7 @@ void EmptySubobjectMap::UpdateEmptyFieldSubobjects(const FieldDecl *FD, } class RecordLayoutBuilder { +protected: // FIXME: Remove this and make the appropriate fields public. friend class clang::ASTContext; @@ -623,12 +626,14 @@ class RecordLayoutBuilder { void SelectPrimaryVBase(const CXXRecordDecl *RD); + virtual uint64_t GetVirtualPointersSize(const CXXRecordDecl *RD) const; + /// IdentifyPrimaryBases - Identify all virtual base classes, direct or /// indirect, that are primary base classes for some other direct or indirect /// base class. void IdentifyPrimaryBases(const CXXRecordDecl *RD); - bool IsNearlyEmpty(const CXXRecordDecl *RD) const; + virtual bool IsNearlyEmpty(const CXXRecordDecl *RD) const; /// LayoutNonVirtualBases - Determines the primary base class (if any) and /// lays it out. Will then proceed to lay out all non-virtual base clasess. @@ -638,7 +643,7 @@ class RecordLayoutBuilder { void LayoutNonVirtualBase(const BaseSubobjectInfo *Base); void AddPrimaryVirtualBaseOffsets(const BaseSubobjectInfo *Info, - uint64_t Offset); + uint64_t Offset); /// LayoutVirtualBases - Lays out all the virtual bases. void LayoutVirtualBases(const CXXRecordDecl *RD, @@ -734,6 +739,11 @@ RecordLayoutBuilder::SelectPrimaryVBase(const CXXRecordDecl *RD) { } } +uint64_t +RecordLayoutBuilder::GetVirtualPointersSize(const CXXRecordDecl *RD) const { + return Context.Target.getPointerWidth(0); +} + /// 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. @@ -794,7 +804,7 @@ void RecordLayoutBuilder::DeterminePrimaryBase(const CXXRecordDecl *RD) { assert(DataSize == 0 && "Vtable pointer must be at offset zero!"); // Update the size. - Size += Context.Target.getPointerWidth(0); + Size += GetVirtualPointersSize(RD); DataSize = Size; // Update the alignment. @@ -1451,6 +1461,38 @@ RecordLayoutBuilder::ComputeKeyFunction(const CXXRecordDecl *RD) { return 0; } +// This class implements layout specific to the Microsoft ABI. +class MSRecordLayoutBuilder: public RecordLayoutBuilder { + friend class ASTContext; + + MSRecordLayoutBuilder(ASTContext& Ctx, EmptySubobjectMap *EmptySubobjects): + RecordLayoutBuilder(Ctx, EmptySubobjects) {} + + virtual bool IsNearlyEmpty(const CXXRecordDecl *RD) const; + virtual uint64_t GetVirtualPointersSize(const CXXRecordDecl *RD) const; +}; + +bool MSRecordLayoutBuilder::IsNearlyEmpty(const CXXRecordDecl *RD) const { + // FIXME: Audit the corners + if (!RD->isDynamicClass()) + return false; + const ASTRecordLayout &BaseInfo = Context.getASTRecordLayout(RD); + // In the Microsoft ABI, classes can have one or two vtable pointers. + if (BaseInfo.getNonVirtualSize() == Context.Target.getPointerWidth(0) || + BaseInfo.getNonVirtualSize() == Context.Target.getPointerWidth(0) * 2) + return true; + return false; +} + +uint64_t +MSRecordLayoutBuilder::GetVirtualPointersSize(const CXXRecordDecl *RD) const { + // We should reserve space for two pointers if the class has both + // virtual functions and virtual bases. + if (RD->isPolymorphic() && RD->getNumVBases() > 0) + return 2 * Context.Target.getPointerWidth(0); + return Context.Target.getPointerWidth(0); +} + /// getASTRecordLayout - Get or compute information about the layout of the /// specified record (struct/union/class), which indicates its size and field /// position information. @@ -1469,8 +1511,13 @@ const ASTRecordLayout &ASTContext::getASTRecordLayout(const RecordDecl *D) { if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) { EmptySubobjectMap EmptySubobjects(*this, RD); - RecordLayoutBuilder Builder(*this, &EmptySubobjects); - Builder.Layout(RD); + // When compiling for Microsoft, use the special MS builder. + RecordLayoutBuilder *Builder; + if (Target.getCXXABI() == "microsoft") + Builder = new MSRecordLayoutBuilder(*this, &EmptySubobjects); + else + Builder = new RecordLayoutBuilder(*this, &EmptySubobjects); + Builder->Layout(RD); // FIXME: This is not always correct. See the part about bitfields at // http://www.codesourcery.com/public/cxx-abi/abi.html#POD for more info. @@ -1479,20 +1526,21 @@ const ASTRecordLayout &ASTContext::getASTRecordLayout(const RecordDecl *D) { // FIXME: This should be done in FinalizeLayout. uint64_t DataSize = - IsPODForThePurposeOfLayout ? Builder.Size : Builder.DataSize; + IsPODForThePurposeOfLayout ? Builder->Size : Builder->DataSize; uint64_t NonVirtualSize = - IsPODForThePurposeOfLayout ? DataSize : Builder.NonVirtualSize; + IsPODForThePurposeOfLayout ? DataSize : Builder->NonVirtualSize; NewEntry = - new (*this) ASTRecordLayout(*this, Builder.Size, Builder.Alignment, - DataSize, Builder.FieldOffsets.data(), - Builder.FieldOffsets.size(), + new (*this) ASTRecordLayout(*this, Builder->Size, Builder->Alignment, + DataSize, Builder->FieldOffsets.data(), + Builder->FieldOffsets.size(), NonVirtualSize, - Builder.NonVirtualAlignment, + Builder->NonVirtualAlignment, EmptySubobjects.SizeOfLargestEmptySubobject, - Builder.PrimaryBase, - Builder.PrimaryBaseIsVirtual, - Builder.Bases, Builder.VBases); + Builder->PrimaryBase, + Builder->PrimaryBaseIsVirtual, + Builder->Bases, Builder->VBases); + delete Builder; } else { RecordLayoutBuilder Builder(*this, /*EmptySubobjects=*/0); Builder.Layout(D); |