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Diffstat (limited to 'clang/include/clang/AST/ODRHash.h')
-rw-r--r-- | clang/include/clang/AST/ODRHash.h | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/clang/include/clang/AST/ODRHash.h b/clang/include/clang/AST/ODRHash.h new file mode 100644 index 00000000000..9af8488fca1 --- /dev/null +++ b/clang/include/clang/AST/ODRHash.h @@ -0,0 +1,84 @@ +//===-- ODRHash.h - Hashing to diagnose ODR failures ------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +/// +/// \file +/// This file contains the declaration of the ODRHash class, which calculates +/// a hash based on AST nodes, which is stable across different runs. +/// +//===----------------------------------------------------------------------===// + +#include "clang/AST/DeclarationName.h" +#include "clang/AST/Type.h" +#include "clang/AST/TemplateBase.h" +#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/FoldingSet.h" +#include "llvm/ADT/PointerUnion.h" +#include "llvm/ADT/SmallVector.h" + +namespace clang { + +class Decl; +class IdentifierInfo; +class NestedNameSpecifer; +class Stmt; +class TemplateParameterList; + +// ODRHash is used to calculate a hash based on AST node contents that +// does not rely on pointer addresses. This allows the hash to not vary +// between runs and is usable to detect ODR problems in modules. To use, +// construct an ODRHash object, then call Add* methods over the nodes that +// need to be hashed. Then call CalculateHash to get the hash value. +// Typically, only one Add* call is needed. clear can be called to reuse the +// object. +class ODRHash { + // Use DenseMaps to convert between Decl and Type pointers and an index value. + llvm::DenseMap<const Decl*, unsigned> DeclMap; + llvm::DenseMap<const Type*, unsigned> TypeMap; + + // Save space by processing bools at the end. + llvm::SmallVector<bool, 128> Bools; + + llvm::FoldingSetNodeID ID; + +public: + ODRHash() {} + + // Use this for ODR checking classes between modules. This method compares + // more information than the AddDecl class. + void AddCXXRecordDecl(const CXXRecordDecl *Record); + + // Process SubDecls of the main Decl. This method calls the DeclVisitor + // while AddDecl does not. + void AddSubDecl(const Decl *D); + + // Reset the object for reuse. + void clear(); + + // Add booleans to ID and uses it to calculate the hash. + unsigned CalculateHash(); + + // Add AST nodes that need to be processed. + void AddDecl(const Decl *D); + void AddType(const Type *T); + void AddQualType(QualType T); + void AddStmt(const Stmt *S); + void AddIdentifierInfo(const IdentifierInfo *II); + void AddNestedNameSpecifier(const NestedNameSpecifier *NNS); + void AddTemplateName(TemplateName Name); + void AddDeclarationName(DeclarationName Name); + void AddTemplateArgument(TemplateArgument TA); + void AddTemplateParameterList(const TemplateParameterList *TPL); + + // Save booleans until the end to lower the size of data to process. + void AddBoolean(bool value); + + static bool isWhitelistedDecl(const Decl* D, const CXXRecordDecl *Record); +}; + +} // end namespace clang |