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Diffstat (limited to 'contrib/llvm/tools/clang/include/clang/AST/VTableBuilder.h')
-rw-r--r-- | contrib/llvm/tools/clang/include/clang/AST/VTableBuilder.h | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/include/clang/AST/VTableBuilder.h b/contrib/llvm/tools/clang/include/clang/AST/VTableBuilder.h new file mode 100644 index 0000000..59bab03 --- /dev/null +++ b/contrib/llvm/tools/clang/include/clang/AST/VTableBuilder.h @@ -0,0 +1,357 @@ +//===--- VTableBuilder.h - C++ vtable layout builder --------------*- C++ -*-=// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This contains code dealing with generation of the layout of virtual tables. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_CLANG_AST_VTABLEBUILDER_H +#define LLVM_CLANG_AST_VTABLEBUILDER_H + +#include "clang/AST/BaseSubobject.h" +#include "clang/AST/CXXInheritance.h" +#include "clang/AST/GlobalDecl.h" +#include "clang/AST/RecordLayout.h" +#include "clang/Basic/ABI.h" +#include "llvm/ADT/SetVector.h" +#include <utility> + +namespace clang { + class CXXRecordDecl; + +/// VTableComponent - Represents a single component in a vtable. +class VTableComponent { +public: + enum Kind { + CK_VCallOffset, + CK_VBaseOffset, + CK_OffsetToTop, + CK_RTTI, + CK_FunctionPointer, + + /// CK_CompleteDtorPointer - A pointer to the complete destructor. + CK_CompleteDtorPointer, + + /// CK_DeletingDtorPointer - A pointer to the deleting destructor. + CK_DeletingDtorPointer, + + /// CK_UnusedFunctionPointer - In some cases, a vtable function pointer + /// will end up never being called. Such vtable function pointers are + /// represented as a CK_UnusedFunctionPointer. + CK_UnusedFunctionPointer + }; + + VTableComponent() { } + + static VTableComponent MakeVCallOffset(CharUnits Offset) { + return VTableComponent(CK_VCallOffset, Offset); + } + + static VTableComponent MakeVBaseOffset(CharUnits Offset) { + return VTableComponent(CK_VBaseOffset, Offset); + } + + static VTableComponent MakeOffsetToTop(CharUnits Offset) { + return VTableComponent(CK_OffsetToTop, Offset); + } + + static VTableComponent MakeRTTI(const CXXRecordDecl *RD) { + return VTableComponent(CK_RTTI, reinterpret_cast<uintptr_t>(RD)); + } + + static VTableComponent MakeFunction(const CXXMethodDecl *MD) { + assert(!isa<CXXDestructorDecl>(MD) && + "Don't use MakeFunction with destructors!"); + + return VTableComponent(CK_FunctionPointer, + reinterpret_cast<uintptr_t>(MD)); + } + + static VTableComponent MakeCompleteDtor(const CXXDestructorDecl *DD) { + return VTableComponent(CK_CompleteDtorPointer, + reinterpret_cast<uintptr_t>(DD)); + } + + static VTableComponent MakeDeletingDtor(const CXXDestructorDecl *DD) { + return VTableComponent(CK_DeletingDtorPointer, + reinterpret_cast<uintptr_t>(DD)); + } + + static VTableComponent MakeUnusedFunction(const CXXMethodDecl *MD) { + assert(!isa<CXXDestructorDecl>(MD) && + "Don't use MakeUnusedFunction with destructors!"); + return VTableComponent(CK_UnusedFunctionPointer, + reinterpret_cast<uintptr_t>(MD)); + } + + static VTableComponent getFromOpaqueInteger(uint64_t I) { + return VTableComponent(I); + } + + /// getKind - Get the kind of this vtable component. + Kind getKind() const { + return (Kind)(Value & 0x7); + } + + CharUnits getVCallOffset() const { + assert(getKind() == CK_VCallOffset && "Invalid component kind!"); + + return getOffset(); + } + + CharUnits getVBaseOffset() const { + assert(getKind() == CK_VBaseOffset && "Invalid component kind!"); + + return getOffset(); + } + + CharUnits getOffsetToTop() const { + assert(getKind() == CK_OffsetToTop && "Invalid component kind!"); + + return getOffset(); + } + + const CXXRecordDecl *getRTTIDecl() const { + assert(getKind() == CK_RTTI && "Invalid component kind!"); + + return reinterpret_cast<CXXRecordDecl *>(getPointer()); + } + + const CXXMethodDecl *getFunctionDecl() const { + assert(getKind() == CK_FunctionPointer); + + return reinterpret_cast<CXXMethodDecl *>(getPointer()); + } + + const CXXDestructorDecl *getDestructorDecl() const { + assert((getKind() == CK_CompleteDtorPointer || + getKind() == CK_DeletingDtorPointer) && "Invalid component kind!"); + + return reinterpret_cast<CXXDestructorDecl *>(getPointer()); + } + + const CXXMethodDecl *getUnusedFunctionDecl() const { + assert(getKind() == CK_UnusedFunctionPointer); + + return reinterpret_cast<CXXMethodDecl *>(getPointer()); + } + +private: + VTableComponent(Kind ComponentKind, CharUnits Offset) { + assert((ComponentKind == CK_VCallOffset || + ComponentKind == CK_VBaseOffset || + ComponentKind == CK_OffsetToTop) && "Invalid component kind!"); + assert(Offset.getQuantity() <= ((1LL << 56) - 1) && "Offset is too big!"); + + Value = ((Offset.getQuantity() << 3) | ComponentKind); + } + + VTableComponent(Kind ComponentKind, uintptr_t Ptr) { + assert((ComponentKind == CK_RTTI || + ComponentKind == CK_FunctionPointer || + ComponentKind == CK_CompleteDtorPointer || + ComponentKind == CK_DeletingDtorPointer || + ComponentKind == CK_UnusedFunctionPointer) && + "Invalid component kind!"); + + assert((Ptr & 7) == 0 && "Pointer not sufficiently aligned!"); + + Value = Ptr | ComponentKind; + } + + CharUnits getOffset() const { + assert((getKind() == CK_VCallOffset || getKind() == CK_VBaseOffset || + getKind() == CK_OffsetToTop) && "Invalid component kind!"); + + return CharUnits::fromQuantity(Value >> 3); + } + + uintptr_t getPointer() const { + assert((getKind() == CK_RTTI || + getKind() == CK_FunctionPointer || + getKind() == CK_CompleteDtorPointer || + getKind() == CK_DeletingDtorPointer || + getKind() == CK_UnusedFunctionPointer) && + "Invalid component kind!"); + + return static_cast<uintptr_t>(Value & ~7ULL); + } + + explicit VTableComponent(uint64_t Value) + : Value(Value) { } + + /// The kind is stored in the lower 3 bits of the value. For offsets, we + /// make use of the facts that classes can't be larger than 2^55 bytes, + /// so we store the offset in the lower part of the 61 bytes that remain. + /// (The reason that we're not simply using a PointerIntPair here is that we + /// need the offsets to be 64-bit, even when on a 32-bit machine). + int64_t Value; +}; + +class VTableLayout { +public: + typedef std::pair<uint64_t, ThunkInfo> VTableThunkTy; + typedef SmallVector<ThunkInfo, 1> ThunkInfoVectorTy; + + typedef const VTableComponent *vtable_component_iterator; + typedef const VTableThunkTy *vtable_thunk_iterator; + + typedef llvm::DenseMap<BaseSubobject, uint64_t> AddressPointsMapTy; +private: + uint64_t NumVTableComponents; + VTableComponent *VTableComponents; + + /// VTableThunks - Contains thunks needed by vtables. + uint64_t NumVTableThunks; + VTableThunkTy *VTableThunks; + + /// Address points - Address points for all vtables. + AddressPointsMapTy AddressPoints; + +public: + VTableLayout(uint64_t NumVTableComponents, + const VTableComponent *VTableComponents, + uint64_t NumVTableThunks, + const VTableThunkTy *VTableThunks, + const AddressPointsMapTy &AddressPoints); + ~VTableLayout(); + + uint64_t getNumVTableComponents() const { + return NumVTableComponents; + } + + vtable_component_iterator vtable_component_begin() const { + return VTableComponents; + } + + vtable_component_iterator vtable_component_end() const { + return VTableComponents+NumVTableComponents; + } + + uint64_t getNumVTableThunks() const { + return NumVTableThunks; + } + + vtable_thunk_iterator vtable_thunk_begin() const { + return VTableThunks; + } + + vtable_thunk_iterator vtable_thunk_end() const { + return VTableThunks+NumVTableThunks; + } + + uint64_t getAddressPoint(BaseSubobject Base) const { + assert(AddressPoints.count(Base) && + "Did not find address point!"); + + uint64_t AddressPoint = AddressPoints.lookup(Base); + assert(AddressPoint && "Address point must not be zero!"); + + return AddressPoint; + } + + const AddressPointsMapTy &getAddressPoints() const { + return AddressPoints; + } +}; + +class VTableContext { + ASTContext &Context; + +public: + typedef SmallVector<std::pair<uint64_t, ThunkInfo>, 1> + VTableThunksTy; + typedef SmallVector<ThunkInfo, 1> ThunkInfoVectorTy; + +private: + /// MethodVTableIndices - Contains the index (relative to the vtable address + /// point) where the function pointer for a virtual function is stored. + typedef llvm::DenseMap<GlobalDecl, int64_t> MethodVTableIndicesTy; + MethodVTableIndicesTy MethodVTableIndices; + + typedef llvm::DenseMap<const CXXRecordDecl *, const VTableLayout *> + VTableLayoutMapTy; + VTableLayoutMapTy VTableLayouts; + + /// NumVirtualFunctionPointers - Contains the number of virtual function + /// pointers in the vtable for a given record decl. + llvm::DenseMap<const CXXRecordDecl *, uint64_t> NumVirtualFunctionPointers; + + typedef std::pair<const CXXRecordDecl *, + const CXXRecordDecl *> ClassPairTy; + + /// VirtualBaseClassOffsetOffsets - Contains the vtable offset (relative to + /// the address point) in chars where the offsets for virtual bases of a class + /// are stored. + typedef llvm::DenseMap<ClassPairTy, CharUnits> + VirtualBaseClassOffsetOffsetsMapTy; + VirtualBaseClassOffsetOffsetsMapTy VirtualBaseClassOffsetOffsets; + + typedef llvm::DenseMap<const CXXMethodDecl *, ThunkInfoVectorTy> ThunksMapTy; + + /// Thunks - Contains all thunks that a given method decl will need. + ThunksMapTy Thunks; + + void ComputeMethodVTableIndices(const CXXRecordDecl *RD); + + /// ComputeVTableRelatedInformation - Compute and store all vtable related + /// information (vtable layout, vbase offset offsets, thunks etc) for the + /// given record decl. + void ComputeVTableRelatedInformation(const CXXRecordDecl *RD); + +public: + VTableContext(ASTContext &Context) : Context(Context) {} + ~VTableContext(); + + const VTableLayout &getVTableLayout(const CXXRecordDecl *RD) { + ComputeVTableRelatedInformation(RD); + assert(VTableLayouts.count(RD) && "No layout for this record decl!"); + + return *VTableLayouts[RD]; + } + + VTableLayout * + createConstructionVTableLayout(const CXXRecordDecl *MostDerivedClass, + CharUnits MostDerivedClassOffset, + bool MostDerivedClassIsVirtual, + const CXXRecordDecl *LayoutClass); + + const ThunkInfoVectorTy *getThunkInfo(const CXXMethodDecl *MD) { + ComputeVTableRelatedInformation(MD->getParent()); + + ThunksMapTy::const_iterator I = Thunks.find(MD); + if (I == Thunks.end()) { + // We did not find a thunk for this method. + return 0; + } + + return &I->second; + } + + /// getNumVirtualFunctionPointers - Return the number of virtual function + /// pointers in the vtable for a given record decl. + uint64_t getNumVirtualFunctionPointers(const CXXRecordDecl *RD); + + /// getMethodVTableIndex - Return the index (relative to the vtable address + /// point) where the function pointer for the given virtual function is + /// stored. + uint64_t getMethodVTableIndex(GlobalDecl GD); + + /// getVirtualBaseOffsetOffset - Return the offset in chars (relative to the + /// vtable address point) where the offset of the virtual base that contains + /// the given base is stored, otherwise, if no virtual base contains the given + /// class, return 0. Base must be a virtual base class or an unambigious + /// base. + CharUnits getVirtualBaseOffsetOffset(const CXXRecordDecl *RD, + const CXXRecordDecl *VBase); +}; + +} + +#endif |