| 1 | //===-- ODRHash.h - Hashing to diagnose ODR failures ------------*- 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 | /// \file |
| 10 | /// This file contains the declaration of the ODRHash class, which calculates |
| 11 | /// a hash based on AST nodes, which is stable across different runs. |
| 12 | /// |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #ifndef LLVM_CLANG_AST_ODRHASH_H |
| 16 | #define LLVM_CLANG_AST_ODRHASH_H |
| 17 | |
| 18 | #include "clang/AST/DeclarationName.h" |
| 19 | #include "clang/AST/Type.h" |
| 20 | #include "clang/AST/TemplateBase.h" |
| 21 | #include "llvm/ADT/DenseMap.h" |
| 22 | #include "llvm/ADT/FoldingSet.h" |
| 23 | #include "llvm/ADT/PointerUnion.h" |
| 24 | #include "llvm/ADT/SmallVector.h" |
| 25 | |
| 26 | namespace clang { |
| 27 | |
| 28 | class Decl; |
| 29 | class IdentifierInfo; |
| 30 | class NestedNameSpecifier; |
| 31 | class Stmt; |
| 32 | class TemplateParameterList; |
| 33 | |
| 34 | // ODRHash is used to calculate a hash based on AST node contents that |
| 35 | // does not rely on pointer addresses. This allows the hash to not vary |
| 36 | // between runs and is usable to detect ODR problems in modules. To use, |
| 37 | // construct an ODRHash object, then call Add* methods over the nodes that |
| 38 | // need to be hashed. Then call CalculateHash to get the hash value. |
| 39 | // Typically, only one Add* call is needed. clear can be called to reuse the |
| 40 | // object. |
| 41 | class ODRHash { |
| 42 | // Use DenseMaps to convert from DeclarationName and Type pointers |
| 43 | // to an index value. |
| 44 | llvm::DenseMap<DeclarationName, unsigned> DeclNameMap; |
| 45 | |
| 46 | // Save space by processing bools at the end. |
| 47 | llvm::SmallVector<bool, 128> Bools; |
| 48 | |
| 49 | llvm::FoldingSetNodeID ID; |
| 50 | |
| 51 | public: |
| 52 | ODRHash() {} |
| 53 | |
| 54 | // Use this for ODR checking classes between modules. This method compares |
| 55 | // more information than the AddDecl class. |
| 56 | void AddCXXRecordDecl(const CXXRecordDecl *Record); |
| 57 | |
| 58 | // Use this for ODR checking functions between modules. This method compares |
| 59 | // more information than the AddDecl class. SkipBody will process the |
| 60 | // hash as if the function has no body. |
| 61 | void AddFunctionDecl(const FunctionDecl *Function, bool SkipBody = false); |
| 62 | |
| 63 | // Use this for ODR checking enums between modules. This method compares |
| 64 | // more information than the AddDecl class. |
| 65 | void AddEnumDecl(const EnumDecl *Enum); |
| 66 | |
| 67 | // Process SubDecls of the main Decl. This method calls the DeclVisitor |
| 68 | // while AddDecl does not. |
| 69 | void AddSubDecl(const Decl *D); |
| 70 | |
| 71 | // Reset the object for reuse. |
| 72 | void clear(); |
| 73 | |
| 74 | // Add booleans to ID and uses it to calculate the hash. |
| 75 | unsigned CalculateHash(); |
| 76 | |
| 77 | // Add AST nodes that need to be processed. |
| 78 | void AddDecl(const Decl *D); |
| 79 | void AddType(const Type *T); |
| 80 | void AddQualType(QualType T); |
| 81 | void AddStmt(const Stmt *S); |
| 82 | void AddIdentifierInfo(const IdentifierInfo *II); |
| 83 | void AddNestedNameSpecifier(const NestedNameSpecifier *NNS); |
| 84 | void AddTemplateName(TemplateName Name); |
| 85 | void AddDeclarationName(DeclarationName Name, bool TreatAsDecl = false); |
| 86 | void AddTemplateArgument(TemplateArgument TA); |
| 87 | void AddTemplateParameterList(const TemplateParameterList *TPL); |
| 88 | |
| 89 | // Save booleans until the end to lower the size of data to process. |
| 90 | void AddBoolean(bool value); |
| 91 | |
| 92 | static bool isWhitelistedDecl(const Decl* D, const DeclContext *Parent); |
| 93 | |
| 94 | private: |
| 95 | void AddDeclarationNameImpl(DeclarationName Name); |
| 96 | }; |
| 97 | |
| 98 | } // end namespace clang |
| 99 | |
| 100 | #endif |
| 101 |