1 //===-- ODRHash.h - Hashing to diagnose ODR failures ------------*- 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 /// \file 11 /// This file contains the declaration of the ODRHash class, which calculates 12 /// a hash based on AST nodes, which is stable across different runs. 13 /// 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_CLANG_AST_ODRHASH_H 17 #define LLVM_CLANG_AST_ODRHASH_H 18 19 #include "clang/AST/DeclarationName.h" 20 #include "clang/AST/Type.h" 21 #include "clang/AST/TemplateBase.h" 22 #include "llvm/ADT/DenseMap.h" 23 #include "llvm/ADT/FoldingSet.h" 24 #include "llvm/ADT/PointerUnion.h" 25 #include "llvm/ADT/SmallVector.h" 26 27 namespace clang { 28 29 class Decl; 30 class IdentifierInfo; 31 class NestedNameSpecifier; 32 class Stmt; 33 class TemplateParameterList; 34 35 // ODRHash is used to calculate a hash based on AST node contents that 36 // does not rely on pointer addresses. This allows the hash to not vary 37 // between runs and is usable to detect ODR problems in modules. To use, 38 // construct an ODRHash object, then call Add* methods over the nodes that 39 // need to be hashed. Then call CalculateHash to get the hash value. 40 // Typically, only one Add* call is needed. clear can be called to reuse the 41 // object. 42 class ODRHash { 43 // Use DenseMaps to convert from DeclarationName and Type pointers 44 // to an index value. 45 llvm::DenseMap<DeclarationName, unsigned> DeclNameMap; 46 47 // Save space by processing bools at the end. 48 llvm::SmallVector<bool, 128> Bools; 49 50 llvm::FoldingSetNodeID ID; 51 52 public: ODRHash()53 ODRHash() {} 54 55 // Use this for ODR checking classes between modules. This method compares 56 // more information than the AddDecl class. 57 void AddCXXRecordDecl(const CXXRecordDecl *Record); 58 59 // Use this for ODR checking functions between modules. This method compares 60 // more information than the AddDecl class. SkipBody will process the 61 // hash as if the function has no body. 62 void AddFunctionDecl(const FunctionDecl *Function, bool SkipBody = false); 63 64 // Use this for ODR checking enums between modules. This method compares 65 // more information than the AddDecl class. 66 void AddEnumDecl(const EnumDecl *Enum); 67 68 // Process SubDecls of the main Decl. This method calls the DeclVisitor 69 // while AddDecl does not. 70 void AddSubDecl(const Decl *D); 71 72 // Reset the object for reuse. 73 void clear(); 74 75 // Add booleans to ID and uses it to calculate the hash. 76 unsigned CalculateHash(); 77 78 // Add AST nodes that need to be processed. 79 void AddDecl(const Decl *D); 80 void AddType(const Type *T); 81 void AddQualType(QualType T); 82 void AddStmt(const Stmt *S); 83 void AddIdentifierInfo(const IdentifierInfo *II); 84 void AddNestedNameSpecifier(const NestedNameSpecifier *NNS); 85 void AddTemplateName(TemplateName Name); 86 void AddDeclarationName(DeclarationName Name, bool TreatAsDecl = false); 87 void AddTemplateArgument(TemplateArgument TA); 88 void AddTemplateParameterList(const TemplateParameterList *TPL); 89 90 // Save booleans until the end to lower the size of data to process. 91 void AddBoolean(bool value); 92 93 static bool isWhitelistedDecl(const Decl* D, const DeclContext *Parent); 94 95 private: 96 void AddDeclarationNameImpl(DeclarationName Name); 97 }; 98 99 } // end namespace clang 100 101 #endif 102