1//===--- CGVTables.h - Emit LLVM Code for C++ vtables -----------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code dealing with C++ code generation of virtual tables.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef CLANG_CODEGEN_CGVTABLE_H
15#define CLANG_CODEGEN_CGVTABLE_H
16
17#include "clang/AST/BaseSubobject.h"
18#include "clang/AST/CharUnits.h"
19#include "clang/AST/GlobalDecl.h"
20#include "clang/AST/VTableBuilder.h"
21#include "clang/Basic/ABI.h"
22#include "llvm/ADT/DenseMap.h"
23#include "llvm/IR/GlobalVariable.h"
24
25namespace clang {
26  class CXXRecordDecl;
27
28namespace CodeGen {
29  class CodeGenModule;
30
31class CodeGenVTables {
32  CodeGenModule &CGM;
33
34  VTableContextBase *VTContext;
35
36  /// VTableAddressPointsMapTy - Address points for a single vtable.
37  typedef llvm::DenseMap<BaseSubobject, uint64_t> VTableAddressPointsMapTy;
38
39  typedef std::pair<const CXXRecordDecl *, BaseSubobject> BaseSubobjectPairTy;
40  typedef llvm::DenseMap<BaseSubobjectPairTy, uint64_t> SubVTTIndiciesMapTy;
41
42  /// SubVTTIndicies - Contains indices into the various sub-VTTs.
43  SubVTTIndiciesMapTy SubVTTIndicies;
44
45  typedef llvm::DenseMap<BaseSubobjectPairTy, uint64_t>
46    SecondaryVirtualPointerIndicesMapTy;
47
48  /// SecondaryVirtualPointerIndices - Contains the secondary virtual pointer
49  /// indices.
50  SecondaryVirtualPointerIndicesMapTy SecondaryVirtualPointerIndices;
51
52  /// emitThunk - Emit a single thunk.
53  void emitThunk(GlobalDecl GD, const ThunkInfo &Thunk, bool ForVTable);
54
55  /// maybeEmitThunkForVTable - Emit the given thunk for the vtable if needed by
56  /// the ABI.
57  void maybeEmitThunkForVTable(GlobalDecl GD, const ThunkInfo &Thunk);
58
59public:
60  /// CreateVTableInitializer - Create a vtable initializer for the given record
61  /// decl.
62  /// \param Components - The vtable components; this is really an array of
63  /// VTableComponents.
64  llvm::Constant *CreateVTableInitializer(
65      const CXXRecordDecl *RD, const VTableComponent *Components,
66      unsigned NumComponents, const VTableLayout::VTableThunkTy *VTableThunks,
67      unsigned NumVTableThunks, llvm::Constant *RTTI);
68
69  CodeGenVTables(CodeGenModule &CGM);
70
71  ItaniumVTableContext &getItaniumVTableContext() {
72    return *cast<ItaniumVTableContext>(VTContext);
73  }
74
75  MicrosoftVTableContext &getMicrosoftVTableContext() {
76    return *cast<MicrosoftVTableContext>(VTContext);
77  }
78
79  /// getSubVTTIndex - Return the index of the sub-VTT for the base class of the
80  /// given record decl.
81  uint64_t getSubVTTIndex(const CXXRecordDecl *RD, BaseSubobject Base);
82
83  /// getSecondaryVirtualPointerIndex - Return the index in the VTT where the
84  /// virtual pointer for the given subobject is located.
85  uint64_t getSecondaryVirtualPointerIndex(const CXXRecordDecl *RD,
86                                           BaseSubobject Base);
87
88  /// getAddressPoint - Get the address point of the given subobject in the
89  /// class decl.
90  uint64_t getAddressPoint(BaseSubobject Base, const CXXRecordDecl *RD);
91
92  /// GenerateConstructionVTable - Generate a construction vtable for the given
93  /// base subobject.
94  llvm::GlobalVariable *
95  GenerateConstructionVTable(const CXXRecordDecl *RD, const BaseSubobject &Base,
96                             bool BaseIsVirtual,
97                             llvm::GlobalVariable::LinkageTypes Linkage,
98                             VTableAddressPointsMapTy& AddressPoints);
99
100
101  /// GetAddrOfVTT - Get the address of the VTT for the given record decl.
102  llvm::GlobalVariable *GetAddrOfVTT(const CXXRecordDecl *RD);
103
104  /// EmitVTTDefinition - Emit the definition of the given vtable.
105  void EmitVTTDefinition(llvm::GlobalVariable *VTT,
106                         llvm::GlobalVariable::LinkageTypes Linkage,
107                         const CXXRecordDecl *RD);
108
109  /// EmitThunks - Emit the associated thunks for the given global decl.
110  void EmitThunks(GlobalDecl GD);
111
112  /// GenerateClassData - Generate all the class data required to be
113  /// generated upon definition of a KeyFunction.  This includes the
114  /// vtable, the RTTI data structure (if RTTI is enabled) and the VTT
115  /// (if the class has virtual bases).
116  void GenerateClassData(const CXXRecordDecl *RD);
117
118  bool isVTableExternal(const CXXRecordDecl *RD);
119};
120
121} // end namespace CodeGen
122} // end namespace clang
123#endif
124