1 //===--- VTTBuilder.h - C++ VTT layout builder --------------------*- C++ -*-=//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This contains code dealing with generation of the layout of virtual table
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CLANG_AST_VTTBUILDER_H
16 #define LLVM_CLANG_AST_VTTBUILDER_H
18 #include "clang/AST/BaseSubobject.h"
19 #include "clang/AST/CXXInheritance.h"
20 #include "clang/AST/GlobalDecl.h"
21 #include "clang/AST/RecordLayout.h"
22 #include "clang/Basic/ABI.h"
23 #include "llvm/ADT/SetVector.h"
29 llvm::PointerIntPair<const CXXRecordDecl *, 1, bool> BaseAndIsVirtual;
34 VTTVTable(const CXXRecordDecl *Base, CharUnits BaseOffset, bool BaseIsVirtual)
35 : BaseAndIsVirtual(Base, BaseIsVirtual), BaseOffset(BaseOffset) {}
36 VTTVTable(BaseSubobject Base, bool BaseIsVirtual)
37 : BaseAndIsVirtual(Base.getBase(), BaseIsVirtual),
38 BaseOffset(Base.getBaseOffset()) {}
40 const CXXRecordDecl *getBase() const {
41 return BaseAndIsVirtual.getPointer();
44 CharUnits getBaseOffset() const {
48 bool isVirtual() const {
49 return BaseAndIsVirtual.getInt();
52 BaseSubobject getBaseSubobject() const {
53 return BaseSubobject(getBase(), getBaseOffset());
59 BaseSubobject VTableBase;
62 VTTComponent(uint64_t VTableIndex, BaseSubobject VTableBase)
63 : VTableIndex(VTableIndex), VTableBase(VTableBase) {}
66 /// \brief Class for building VTT layout information.
71 /// \brief The most derived class for which we're building this vtable.
72 const CXXRecordDecl *MostDerivedClass;
74 typedef SmallVector<VTTVTable, 64> VTTVTablesVectorTy;
76 /// \brief The VTT vtables.
77 VTTVTablesVectorTy VTTVTables;
79 typedef SmallVector<VTTComponent, 64> VTTComponentsVectorTy;
81 /// \brief The VTT components.
82 VTTComponentsVectorTy VTTComponents;
84 /// \brief The AST record layout of the most derived class.
85 const ASTRecordLayout &MostDerivedClassLayout;
87 typedef llvm::SmallPtrSet<const CXXRecordDecl *, 4> VisitedVirtualBasesSetTy;
89 typedef llvm::DenseMap<BaseSubobject, uint64_t> AddressPointsMapTy;
91 /// \brief The sub-VTT indices for the bases of the most derived class.
92 llvm::DenseMap<BaseSubobject, uint64_t> SubVTTIndicies;
94 /// \brief The secondary virtual pointer indices of all subobjects of
95 /// the most derived class.
96 llvm::DenseMap<BaseSubobject, uint64_t> SecondaryVirtualPointerIndices;
98 /// \brief Whether the VTT builder should generate LLVM IR for the VTT.
99 bool GenerateDefinition;
101 /// \brief Add a vtable pointer to the VTT currently being built.
102 void AddVTablePointer(BaseSubobject Base, uint64_t VTableIndex,
103 const CXXRecordDecl *VTableClass);
105 /// \brief Lay out the secondary VTTs of the given base subobject.
106 void LayoutSecondaryVTTs(BaseSubobject Base);
108 /// \brief Lay out the secondary virtual pointers for the given base
111 /// \param BaseIsMorallyVirtual whether the base subobject is a virtual base
112 /// or a direct or indirect base of a virtual base.
113 void LayoutSecondaryVirtualPointers(BaseSubobject Base,
114 bool BaseIsMorallyVirtual,
115 uint64_t VTableIndex,
116 const CXXRecordDecl *VTableClass,
117 VisitedVirtualBasesSetTy &VBases);
119 /// \brief Lay out the secondary virtual pointers for the given base
121 void LayoutSecondaryVirtualPointers(BaseSubobject Base,
122 uint64_t VTableIndex);
124 /// \brief Lay out the VTTs for the virtual base classes of the given
125 /// record declaration.
126 void LayoutVirtualVTTs(const CXXRecordDecl *RD,
127 VisitedVirtualBasesSetTy &VBases);
129 /// \brief Lay out the VTT for the given subobject, including any
130 /// secondary VTTs, secondary virtual pointers and virtual VTTs.
131 void LayoutVTT(BaseSubobject Base, bool BaseIsVirtual);
134 VTTBuilder(ASTContext &Ctx, const CXXRecordDecl *MostDerivedClass,
135 bool GenerateDefinition);
137 // \brief Returns a reference to the VTT components.
138 const VTTComponentsVectorTy &getVTTComponents() const {
139 return VTTComponents;
142 // \brief Returns a reference to the VTT vtables.
143 const VTTVTablesVectorTy &getVTTVTables() const {
147 /// \brief Returns a reference to the sub-VTT indices.
148 const llvm::DenseMap<BaseSubobject, uint64_t> &getSubVTTIndicies() const {
149 return SubVTTIndicies;
152 /// \brief Returns a reference to the secondary virtual pointer indices.
153 const llvm::DenseMap<BaseSubobject, uint64_t> &
154 getSecondaryVirtualPointerIndices() const {
155 return SecondaryVirtualPointerIndices;