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 LLVM_CLANG_LIB_CODEGEN_CGVTABLES_H 15 #define LLVM_CLANG_LIB_CODEGEN_CGVTABLES_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 25 namespace clang { 26 class CXXRecordDecl; 27 28 namespace CodeGen { 29 class CodeGenModule; 30 31 class 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 59 public: 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 getItaniumVTableContext()71 ItaniumVTableContext &getItaniumVTableContext() { 72 return *cast<ItaniumVTableContext>(VTContext); 73 } 74 getMicrosoftVTableContext()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 /// GenerateConstructionVTable - Generate a construction vtable for the given 89 /// base subobject. 90 llvm::GlobalVariable * 91 GenerateConstructionVTable(const CXXRecordDecl *RD, const BaseSubobject &Base, 92 bool BaseIsVirtual, 93 llvm::GlobalVariable::LinkageTypes Linkage, 94 VTableAddressPointsMapTy& AddressPoints); 95 96 97 /// GetAddrOfVTT - Get the address of the VTT for the given record decl. 98 llvm::GlobalVariable *GetAddrOfVTT(const CXXRecordDecl *RD); 99 100 /// EmitVTTDefinition - Emit the definition of the given vtable. 101 void EmitVTTDefinition(llvm::GlobalVariable *VTT, 102 llvm::GlobalVariable::LinkageTypes Linkage, 103 const CXXRecordDecl *RD); 104 105 /// EmitThunks - Emit the associated thunks for the given global decl. 106 void EmitThunks(GlobalDecl GD); 107 108 /// GenerateClassData - Generate all the class data required to be 109 /// generated upon definition of a KeyFunction. This includes the 110 /// vtable, the RTTI data structure (if RTTI is enabled) and the VTT 111 /// (if the class has virtual bases). 112 void GenerateClassData(const CXXRecordDecl *RD); 113 114 bool isVTableExternal(const CXXRecordDecl *RD); 115 }; 116 117 } // end namespace CodeGen 118 } // end namespace clang 119 #endif 120