| //===------ CXXInheritance.h - C++ Inheritance ------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file provides routines that help analyzing C++ inheritance hierarchies. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_AST_CXXINHERITANCE_H |
| #define LLVM_CLANG_AST_CXXINHERITANCE_H |
| |
| #include "clang/AST/DeclarationName.h" |
| #include "clang/AST/DeclBase.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/Type.h" |
| #include "clang/AST/TypeOrdering.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include <list> |
| #include <map> |
| #include <cassert> |
| |
| namespace clang { |
| |
| class CXXBaseSpecifier; |
| class CXXMethodDecl; |
| class CXXRecordDecl; |
| class NamedDecl; |
| |
| /// \brief Represents an element in a path from a derived class to a |
| /// base class. |
| /// |
| /// Each step in the path references the link from a |
| /// derived class to one of its direct base classes, along with a |
| /// base "number" that identifies which base subobject of the |
| /// original derived class we are referencing. |
| struct CXXBasePathElement { |
| /// \brief The base specifier that states the link from a derived |
| /// class to a base class, which will be followed by this base |
| /// path element. |
| const CXXBaseSpecifier *Base; |
| |
| /// \brief The record decl of the class that the base is a base of. |
| const CXXRecordDecl *Class; |
| |
| /// \brief Identifies which base class subobject (of type |
| /// \c Base->getType()) this base path element refers to. |
| /// |
| /// This value is only valid if \c !Base->isVirtual(), because there |
| /// is no base numbering for the zero or one virtual bases of a |
| /// given type. |
| int SubobjectNumber; |
| }; |
| |
| /// \brief Represents a path from a specific derived class |
| /// (which is not represented as part of the path) to a particular |
| /// (direct or indirect) base class subobject. |
| /// |
| /// Individual elements in the path are described by the \c CXXBasePathElement |
| /// structure, which captures both the link from a derived class to one of its |
| /// direct bases and identification describing which base class |
| /// subobject is being used. |
| class CXXBasePath : public llvm::SmallVector<CXXBasePathElement, 4> { |
| public: |
| CXXBasePath() : Access(AS_public) {} |
| |
| /// \brief The access along this inheritance path. This is only |
| /// calculated when recording paths. AS_none is a special value |
| /// used to indicate a path which permits no legal access. |
| AccessSpecifier Access; |
| |
| /// \brief The set of declarations found inside this base class |
| /// subobject. |
| DeclContext::lookup_result Decls; |
| |
| void clear() { |
| llvm::SmallVectorImpl<CXXBasePathElement>::clear(); |
| Access = AS_public; |
| } |
| }; |
| |
| /// BasePaths - Represents the set of paths from a derived class to |
| /// one of its (direct or indirect) bases. For example, given the |
| /// following class hierachy: |
| /// |
| /// @code |
| /// class A { }; |
| /// class B : public A { }; |
| /// class C : public A { }; |
| /// class D : public B, public C{ }; |
| /// @endcode |
| /// |
| /// There are two potential BasePaths to represent paths from D to a |
| /// base subobject of type A. One path is (D,0) -> (B,0) -> (A,0) |
| /// and another is (D,0)->(C,0)->(A,1). These two paths actually |
| /// refer to two different base class subobjects of the same type, |
| /// so the BasePaths object refers to an ambiguous path. On the |
| /// other hand, consider the following class hierarchy: |
| /// |
| /// @code |
| /// class A { }; |
| /// class B : public virtual A { }; |
| /// class C : public virtual A { }; |
| /// class D : public B, public C{ }; |
| /// @endcode |
| /// |
| /// Here, there are two potential BasePaths again, (D, 0) -> (B, 0) |
| /// -> (A,v) and (D, 0) -> (C, 0) -> (A, v), but since both of them |
| /// refer to the same base class subobject of type A (the virtual |
| /// one), there is no ambiguity. |
| class CXXBasePaths { |
| /// \brief The type from which this search originated. |
| CXXRecordDecl *Origin; |
| |
| /// Paths - The actual set of paths that can be taken from the |
| /// derived class to the same base class. |
| std::list<CXXBasePath> Paths; |
| |
| /// ClassSubobjects - Records the class subobjects for each class |
| /// type that we've seen. The first element in the pair says |
| /// whether we found a path to a virtual base for that class type, |
| /// while the element contains the number of non-virtual base |
| /// class subobjects for that class type. The key of the map is |
| /// the cv-unqualified canonical type of the base class subobject. |
| std::map<QualType, std::pair<bool, unsigned>, QualTypeOrdering> |
| ClassSubobjects; |
| |
| /// FindAmbiguities - Whether Sema::IsDerivedFrom should try find |
| /// ambiguous paths while it is looking for a path from a derived |
| /// type to a base type. |
| bool FindAmbiguities; |
| |
| /// RecordPaths - Whether Sema::IsDerivedFrom should record paths |
| /// while it is determining whether there are paths from a derived |
| /// type to a base type. |
| bool RecordPaths; |
| |
| /// DetectVirtual - Whether Sema::IsDerivedFrom should abort the search |
| /// if it finds a path that goes across a virtual base. The virtual class |
| /// is also recorded. |
| bool DetectVirtual; |
| |
| /// ScratchPath - A BasePath that is used by Sema::lookupInBases |
| /// to help build the set of paths. |
| CXXBasePath ScratchPath; |
| |
| /// DetectedVirtual - The base class that is virtual. |
| const RecordType *DetectedVirtual; |
| |
| /// \brief Array of the declarations that have been found. This |
| /// array is constructed only if needed, e.g., to iterate over the |
| /// results within LookupResult. |
| NamedDecl **DeclsFound; |
| unsigned NumDeclsFound; |
| |
| friend class CXXRecordDecl; |
| |
| void ComputeDeclsFound(); |
| |
| bool lookupInBases(ASTContext &Context, |
| const CXXRecordDecl *Record, |
| CXXRecordDecl::BaseMatchesCallback *BaseMatches, |
| void *UserData); |
| public: |
| typedef std::list<CXXBasePath>::iterator paths_iterator; |
| typedef std::list<CXXBasePath>::const_iterator const_paths_iterator; |
| typedef NamedDecl **decl_iterator; |
| |
| /// BasePaths - Construct a new BasePaths structure to record the |
| /// paths for a derived-to-base search. |
| explicit CXXBasePaths(bool FindAmbiguities = true, |
| bool RecordPaths = true, |
| bool DetectVirtual = true) |
| : FindAmbiguities(FindAmbiguities), RecordPaths(RecordPaths), |
| DetectVirtual(DetectVirtual), DetectedVirtual(0), DeclsFound(0), |
| NumDeclsFound(0) { } |
| |
| ~CXXBasePaths() { delete [] DeclsFound; } |
| |
| paths_iterator begin() { return Paths.begin(); } |
| paths_iterator end() { return Paths.end(); } |
| const_paths_iterator begin() const { return Paths.begin(); } |
| const_paths_iterator end() const { return Paths.end(); } |
| |
| CXXBasePath& front() { return Paths.front(); } |
| const CXXBasePath& front() const { return Paths.front(); } |
| |
| decl_iterator found_decls_begin(); |
| decl_iterator found_decls_end(); |
| |
| /// \brief Determine whether the path from the most-derived type to the |
| /// given base type is ambiguous (i.e., it refers to multiple subobjects of |
| /// the same base type). |
| bool isAmbiguous(QualType BaseType); |
| |
| /// \brief Whether we are finding multiple paths to detect ambiguities. |
| bool isFindingAmbiguities() const { return FindAmbiguities; } |
| |
| /// \brief Whether we are recording paths. |
| bool isRecordingPaths() const { return RecordPaths; } |
| |
| /// \brief Specify whether we should be recording paths or not. |
| void setRecordingPaths(bool RP) { RecordPaths = RP; } |
| |
| /// \brief Whether we are detecting virtual bases. |
| bool isDetectingVirtual() const { return DetectVirtual; } |
| |
| /// \brief The virtual base discovered on the path (if we are merely |
| /// detecting virtuals). |
| const RecordType* getDetectedVirtual() const { |
| return DetectedVirtual; |
| } |
| |
| /// \brief Retrieve the type from which this base-paths search |
| /// began |
| CXXRecordDecl *getOrigin() const { return Origin; } |
| void setOrigin(CXXRecordDecl *Rec) { Origin = Rec; } |
| |
| /// \brief Clear the base-paths results. |
| void clear(); |
| |
| /// \brief Swap this data structure's contents with another CXXBasePaths |
| /// object. |
| void swap(CXXBasePaths &Other); |
| }; |
| |
| } // end namespace clang |
| |
| #endif |