clang 19.0.0git
CGVTables.h
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1//===--- CGVTables.h - Emit LLVM Code for C++ vtables -----------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This contains code dealing with C++ code generation of virtual tables.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CLANG_LIB_CODEGEN_CGVTABLES_H
14#define LLVM_CLANG_LIB_CODEGEN_CGVTABLES_H
15
17#include "clang/AST/CharUnits.h"
20#include "clang/Basic/ABI.h"
21#include "llvm/ADT/DenseMap.h"
22#include "llvm/IR/GlobalVariable.h"
23
24namespace clang {
25 class CXXRecordDecl;
26
27namespace CodeGen {
28 class CodeGenModule;
29 class ConstantArrayBuilder;
30 class ConstantStructBuilder;
31
33 CodeGenModule &CGM;
34
35 VTableContextBase *VTContext;
36
37 /// VTableAddressPointsMapTy - Address points for a single vtable.
38 typedef VTableLayout::AddressPointsMapTy VTableAddressPointsMapTy;
39
40 typedef std::pair<const CXXRecordDecl *, BaseSubobject> BaseSubobjectPairTy;
41 typedef llvm::DenseMap<BaseSubobjectPairTy, uint64_t> SubVTTIndiciesMapTy;
42
43 /// SubVTTIndicies - Contains indices into the various sub-VTTs.
44 SubVTTIndiciesMapTy SubVTTIndicies;
45
46 typedef llvm::DenseMap<BaseSubobjectPairTy, uint64_t>
47 SecondaryVirtualPointerIndicesMapTy;
48
49 /// SecondaryVirtualPointerIndices - Contains the secondary virtual pointer
50 /// indices.
51 SecondaryVirtualPointerIndicesMapTy SecondaryVirtualPointerIndices;
52
53 /// Cache for the pure virtual member call function.
54 llvm::Constant *PureVirtualFn = nullptr;
55
56 /// Cache for the deleted virtual member call function.
57 llvm::Constant *DeletedVirtualFn = nullptr;
58
59 /// Get the address of a thunk and emit it if necessary.
60 llvm::Constant *maybeEmitThunk(GlobalDecl GD,
61 const ThunkInfo &ThunkAdjustments,
62 bool ForVTable);
63
64 void addVTableComponent(ConstantArrayBuilder &builder,
65 const VTableLayout &layout, unsigned componentIndex,
66 llvm::Constant *rtti, unsigned &nextVTableThunkIndex,
67 unsigned vtableAddressPoint,
68 bool vtableHasLocalLinkage);
69
70 /// Add a 32-bit offset to a component relative to the vtable when using the
71 /// relative vtables ABI. The array builder points to the start of the vtable.
72 void addRelativeComponent(ConstantArrayBuilder &builder,
73 llvm::Constant *component,
74 unsigned vtableAddressPoint,
75 bool vtableHasLocalLinkage,
76 bool isCompleteDtor) const;
77
78 bool useRelativeLayout() const;
79
80 llvm::Type *getVTableComponentType() const;
81
82public:
83 /// Add vtable components for the given vtable layout to the given
84 /// global initializer.
86 const VTableLayout &layout, llvm::Constant *rtti,
87 bool vtableHasLocalLinkage);
88
90
92 return *cast<ItaniumVTableContext>(VTContext);
93 }
94
96 return *cast<ItaniumVTableContext>(VTContext);
97 }
98
100 return *cast<MicrosoftVTableContext>(VTContext);
101 }
102
103 /// getSubVTTIndex - Return the index of the sub-VTT for the base class of the
104 /// given record decl.
105 uint64_t getSubVTTIndex(const CXXRecordDecl *RD, BaseSubobject Base);
106
107 /// getSecondaryVirtualPointerIndex - Return the index in the VTT where the
108 /// virtual pointer for the given subobject is located.
111
112 /// GenerateConstructionVTable - Generate a construction vtable for the given
113 /// base subobject.
114 llvm::GlobalVariable *
116 bool BaseIsVirtual,
117 llvm::GlobalVariable::LinkageTypes Linkage,
118 VTableAddressPointsMapTy& AddressPoints);
119
120
121 /// GetAddrOfVTT - Get the address of the VTT for the given record decl.
122 llvm::GlobalVariable *GetAddrOfVTT(const CXXRecordDecl *RD);
123
124 /// EmitVTTDefinition - Emit the definition of the given vtable.
125 void EmitVTTDefinition(llvm::GlobalVariable *VTT,
126 llvm::GlobalVariable::LinkageTypes Linkage,
127 const CXXRecordDecl *RD);
128
129 /// EmitThunks - Emit the associated thunks for the given global decl.
130 void EmitThunks(GlobalDecl GD);
131
132 /// GenerateClassData - Generate all the class data required to be
133 /// generated upon definition of a KeyFunction. This includes the
134 /// vtable, the RTTI data structure (if RTTI is enabled) and the VTT
135 /// (if the class has virtual bases).
136 void GenerateClassData(const CXXRecordDecl *RD);
137
138 bool isVTableExternal(const CXXRecordDecl *RD);
139
140 /// Returns the type of a vtable with the given layout. Normally a struct of
141 /// arrays of pointers, with one struct element for each vtable in the vtable
142 /// group.
143 llvm::Type *getVTableType(const VTableLayout &layout);
144
145 /// Generate a public facing alias for the vtable and make the vtable either
146 /// hidden or private. The alias will have the original linkage and visibility
147 /// of the vtable. This is used for cases under the relative vtables ABI
148 /// when a vtable may not be dso_local.
149 void GenerateRelativeVTableAlias(llvm::GlobalVariable *VTable,
150 llvm::StringRef AliasNameRef);
151
152 /// Specify a global should not be instrumented with hwasan.
153 void RemoveHwasanMetadata(llvm::GlobalValue *GV) const;
154};
155
156} // end namespace CodeGen
157} // end namespace clang
158#endif
Enums/classes describing ABI related information about constructors, destructors and thunks.
Represents a C++ struct/union/class.
Definition: DeclCXX.h:258
This class organizes the cross-function state that is used while generating LLVM code.
llvm::GlobalVariable * GetAddrOfVTT(const CXXRecordDecl *RD)
GetAddrOfVTT - Get the address of the VTT for the given record decl.
Definition: CGVTT.cpp:103
void createVTableInitializer(ConstantStructBuilder &builder, const VTableLayout &layout, llvm::Constant *rtti, bool vtableHasLocalLinkage)
Add vtable components for the given vtable layout to the given global initializer.
Definition: CGVTables.cpp:862
const ItaniumVTableContext & getItaniumVTableContext() const
Definition: CGVTables.h:95
void GenerateClassData(const CXXRecordDecl *RD)
GenerateClassData - Generate all the class data required to be generated upon definition of a KeyFunc...
Definition: CGVTables.cpp:1143
void GenerateRelativeVTableAlias(llvm::GlobalVariable *VTable, llvm::StringRef AliasNameRef)
Generate a public facing alias for the vtable and make the vtable either hidden or private.
Definition: CGVTables.cpp:985
uint64_t getSubVTTIndex(const CXXRecordDecl *RD, BaseSubobject Base)
getSubVTTIndex - Return the index of the sub-VTT for the base class of the given record decl.
Definition: CGVTT.cpp:128
ItaniumVTableContext & getItaniumVTableContext()
Definition: CGVTables.h:91
llvm::GlobalVariable * GenerateConstructionVTable(const CXXRecordDecl *RD, const BaseSubobject &Base, bool BaseIsVirtual, llvm::GlobalVariable::LinkageTypes Linkage, VTableAddressPointsMapTy &AddressPoints)
GenerateConstructionVTable - Generate a construction vtable for the given base subobject.
Definition: CGVTables.cpp:886
llvm::Type * getVTableType(const VTableLayout &layout)
Returns the type of a vtable with the given layout.
Definition: CGVTables.cpp:853
uint64_t getSecondaryVirtualPointerIndex(const CXXRecordDecl *RD, BaseSubobject Base)
getSecondaryVirtualPointerIndex - Return the index in the VTT where the virtual pointer for the given...
Definition: CGVTT.cpp:154
bool isVTableExternal(const CXXRecordDecl *RD)
At this point in the translation unit, does it appear that can we rely on the vtable being defined el...
Definition: CGVTables.cpp:1163
MicrosoftVTableContext & getMicrosoftVTableContext()
Definition: CGVTables.h:99
void RemoveHwasanMetadata(llvm::GlobalValue *GV) const
Specify a global should not be instrumented with hwasan.
Definition: CGVTables.cpp:969
void EmitThunks(GlobalDecl GD)
EmitThunks - Emit the associated thunks for the given global decl.
Definition: CGVTables.cpp:601
void EmitVTTDefinition(llvm::GlobalVariable *VTT, llvm::GlobalVariable::LinkageTypes Linkage, const CXXRecordDecl *RD)
EmitVTTDefinition - Emit the definition of the given vtable.
Definition: CGVTT.cpp:41
A helper class of ConstantInitBuilder, used for building constant array initializers.
A helper class of ConstantInitBuilder, used for building constant struct initializers.
GlobalDecl - represents a global declaration.
Definition: GlobalDecl.h:56
llvm::DenseMap< BaseSubobject, AddressPointLocation > AddressPointsMapTy
The JSON file list parser is used to communicate input to InstallAPI.
Linkage
Describes the different kinds of linkage (C++ [basic.link], C99 6.2.2) that an entity may have.
Definition: Linkage.h:24
The this pointer adjustment as well as an optional return adjustment for a thunk.
Definition: Thunk.h:156