Coverage Report

Created: 2020-09-22 08:39

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/CodeGen/CGVTables.h
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//===--- CGVTables.h - Emit LLVM Code for C++ vtables -----------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This contains code dealing with C++ code generation of virtual tables.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_LIB_CODEGEN_CGVTABLES_H
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#define LLVM_CLANG_LIB_CODEGEN_CGVTABLES_H
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#include "clang/AST/BaseSubobject.h"
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#include "clang/AST/CharUnits.h"
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#include "clang/AST/GlobalDecl.h"
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#include "clang/AST/VTableBuilder.h"
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#include "clang/Basic/ABI.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/IR/GlobalVariable.h"
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namespace clang {
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  class CXXRecordDecl;
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namespace CodeGen {
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  class CodeGenModule;
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  class ConstantArrayBuilder;
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  class ConstantStructBuilder;
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class CodeGenVTables {
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  CodeGenModule &CGM;
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  VTableContextBase *VTContext;
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  /// VTableAddressPointsMapTy - Address points for a single vtable.
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  typedef VTableLayout::AddressPointsMapTy VTableAddressPointsMapTy;
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  typedef std::pair<const CXXRecordDecl *, BaseSubobject> BaseSubobjectPairTy;
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  typedef llvm::DenseMap<BaseSubobjectPairTy, uint64_t> SubVTTIndiciesMapTy;
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  /// SubVTTIndicies - Contains indices into the various sub-VTTs.
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  SubVTTIndiciesMapTy SubVTTIndicies;
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  typedef llvm::DenseMap<BaseSubobjectPairTy, uint64_t>
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    SecondaryVirtualPointerIndicesMapTy;
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  /// SecondaryVirtualPointerIndices - Contains the secondary virtual pointer
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  /// indices.
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  SecondaryVirtualPointerIndicesMapTy SecondaryVirtualPointerIndices;
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  /// Cache for the pure virtual member call function.
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  llvm::Constant *PureVirtualFn = nullptr;
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  /// Cache for the deleted virtual member call function.
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  llvm::Constant *DeletedVirtualFn = nullptr;
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  /// Get the address of a thunk and emit it if necessary.
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  llvm::Constant *maybeEmitThunk(GlobalDecl GD,
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                                 const ThunkInfo &ThunkAdjustments,
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                                 bool ForVTable);
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  void addVTableComponent(ConstantArrayBuilder &builder,
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                          const VTableLayout &layout, unsigned componentIndex,
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                          llvm::Constant *rtti, unsigned &nextVTableThunkIndex,
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                          unsigned vtableAddressPoint,
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                          bool vtableHasLocalLinkage);
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  /// Add a 32-bit offset to a component relative to the vtable when using the
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  /// relative vtables ABI. The array builder points to the start of the vtable.
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  void addRelativeComponent(ConstantArrayBuilder &builder,
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                            llvm::Constant *component,
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                            unsigned vtableAddressPoint,
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                            bool vtableHasLocalLinkage,
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                            bool isCompleteDtor) const;
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  /// Create a dso_local stub that will be used for a relative reference in the
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  /// relative vtable layout. This stub will just be a tail call to the original
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  /// function and propagate any function attributes from the original. If the
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  /// original function is already dso_local, the original is returned instead
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  /// and a stub is not created.
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  llvm::Function *
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  getOrCreateRelativeStub(llvm::Function *func,
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                          llvm::GlobalValue::LinkageTypes stubLinkage,
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                          bool isCompleteDtor) const;
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  bool useRelativeLayout() const;
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  llvm::Type *getVTableComponentType() const;
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public:
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  /// Add vtable components for the given vtable layout to the given
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  /// global initializer.
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  void createVTableInitializer(ConstantStructBuilder &builder,
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                               const VTableLayout &layout, llvm::Constant *rtti,
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                               bool vtableHasLocalLinkage);
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  CodeGenVTables(CodeGenModule &CGM);
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  ItaniumVTableContext &getItaniumVTableContext() {
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    return *cast<ItaniumVTableContext>(VTContext);
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  }
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  MicrosoftVTableContext &getMicrosoftVTableContext() {
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    return *cast<MicrosoftVTableContext>(VTContext);
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  }
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  /// getSubVTTIndex - Return the index of the sub-VTT for the base class of the
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  /// given record decl.
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  uint64_t getSubVTTIndex(const CXXRecordDecl *RD, BaseSubobject Base);
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  /// getSecondaryVirtualPointerIndex - Return the index in the VTT where the
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  /// virtual pointer for the given subobject is located.
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  uint64_t getSecondaryVirtualPointerIndex(const CXXRecordDecl *RD,
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                                           BaseSubobject Base);
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  /// GenerateConstructionVTable - Generate a construction vtable for the given
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  /// base subobject.
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  llvm::GlobalVariable *
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  GenerateConstructionVTable(const CXXRecordDecl *RD, const BaseSubobject &Base,
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                             bool BaseIsVirtual,
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                             llvm::GlobalVariable::LinkageTypes Linkage,
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                             VTableAddressPointsMapTy& AddressPoints);
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  /// GetAddrOfVTT - Get the address of the VTT for the given record decl.
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  llvm::GlobalVariable *GetAddrOfVTT(const CXXRecordDecl *RD);
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  /// EmitVTTDefinition - Emit the definition of the given vtable.
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  void EmitVTTDefinition(llvm::GlobalVariable *VTT,
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                         llvm::GlobalVariable::LinkageTypes Linkage,
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                         const CXXRecordDecl *RD);
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  /// EmitThunks - Emit the associated thunks for the given global decl.
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  void EmitThunks(GlobalDecl GD);
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  /// GenerateClassData - Generate all the class data required to be
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  /// generated upon definition of a KeyFunction.  This includes the
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  /// vtable, the RTTI data structure (if RTTI is enabled) and the VTT
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  /// (if the class has virtual bases).
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  void GenerateClassData(const CXXRecordDecl *RD);
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  bool isVTableExternal(const CXXRecordDecl *RD);
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  /// Returns the type of a vtable with the given layout. Normally a struct of
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  /// arrays of pointers, with one struct element for each vtable in the vtable
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  /// group.
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  llvm::Type *getVTableType(const VTableLayout &layout);
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  /// Generate a public facing alias for the vtable and make the vtable either
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  /// hidden or private. The alias will have the original linkage and visibility
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  /// of the vtable. This is used for cases under the relative vtables ABI
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  /// when a vtable may not be dso_local.
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  void GenerateRelativeVTableAlias(llvm::GlobalVariable *VTable,
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                                   llvm::StringRef AliasNameRef);
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};
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} // end namespace CodeGen
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} // end namespace clang
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#endif