DeclFriend.h revision 1e68ecc4fcce12f683c4fd38acfd1a004001b04f
1//===-- DeclFriend.h - Classes for C++ friend declarations -*- 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// This file defines the section of the AST representing C++ friend 11// declarations. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef LLVM_CLANG_AST_DECLFRIEND_H 16#define LLVM_CLANG_AST_DECLFRIEND_H 17 18#include "clang/AST/DeclCXX.h" 19 20namespace clang { 21 22/// FriendDecl - Represents the declaration of a friend entity, 23/// which can be a function, a type, or a templated function or type. 24// For example: 25/// 26/// @code 27/// template <typename T> class A { 28/// friend int foo(T); 29/// friend class B; 30/// friend T; // only in C++0x 31/// template <typename U> friend class C; 32/// template <typename U> friend A& operator+=(A&, const U&) { ... } 33/// }; 34/// @endcode 35/// 36/// The semantic context of a friend decl is its declaring class. 37class FriendDecl : public Decl { 38 virtual void anchor(); 39public: 40 typedef llvm::PointerUnion<NamedDecl*,TypeSourceInfo*> FriendUnion; 41 42private: 43 // The declaration that's a friend of this class. 44 FriendUnion Friend; 45 46 // A pointer to the next friend in the sequence. 47 LazyDeclPtr NextFriend; 48 49 // Location of the 'friend' specifier. 50 SourceLocation FriendLoc; 51 52 /// True if this 'friend' declaration is unsupported. Eventually we 53 /// will support every possible friend declaration, but for now we 54 /// silently ignore some and set this flag to authorize all access. 55 bool UnsupportedFriend; 56 57 friend class CXXRecordDecl::friend_iterator; 58 friend class CXXRecordDecl; 59 60 FriendDecl(DeclContext *DC, SourceLocation L, FriendUnion Friend, 61 SourceLocation FriendL) 62 : Decl(Decl::Friend, DC, L), 63 Friend(Friend), 64 NextFriend(), 65 FriendLoc(FriendL), 66 UnsupportedFriend(false) { 67 } 68 69 explicit FriendDecl(EmptyShell Empty) 70 : Decl(Decl::Friend, Empty), NextFriend() { } 71 72 FriendDecl *getNextFriend() { 73 return cast_or_null<FriendDecl>( 74 NextFriend.get(getASTContext().getExternalSource())); 75 } 76 77public: 78 static FriendDecl *Create(ASTContext &C, DeclContext *DC, 79 SourceLocation L, FriendUnion Friend_, 80 SourceLocation FriendL); 81 static FriendDecl *CreateDeserialized(ASTContext &C, unsigned ID); 82 83 /// If this friend declaration names an (untemplated but possibly 84 /// dependent) type, return the type; otherwise return null. This 85 /// is used for elaborated-type-specifiers and, in C++0x, for 86 /// arbitrary friend type declarations. 87 TypeSourceInfo *getFriendType() const { 88 return Friend.dyn_cast<TypeSourceInfo*>(); 89 } 90 91 /// If this friend declaration doesn't name a type, return the inner 92 /// declaration. 93 NamedDecl *getFriendDecl() const { 94 return Friend.dyn_cast<NamedDecl*>(); 95 } 96 97 /// Retrieves the location of the 'friend' keyword. 98 SourceLocation getFriendLoc() const { 99 return FriendLoc; 100 } 101 102 /// Retrieves the source range for the friend declaration. 103 SourceRange getSourceRange() const { 104 /* FIXME: consider the case of templates wrt start of range. */ 105 if (NamedDecl *ND = getFriendDecl()) 106 return SourceRange(getFriendLoc(), ND->getLocEnd()); 107 else if (TypeSourceInfo *TInfo = getFriendType()) 108 return SourceRange(getFriendLoc(), TInfo->getTypeLoc().getEndLoc()); 109 else 110 return SourceRange(getFriendLoc(), getLocation()); 111 } 112 113 /// Determines if this friend kind is unsupported. 114 bool isUnsupportedFriend() const { 115 return UnsupportedFriend; 116 } 117 void setUnsupportedFriend(bool Unsupported) { 118 UnsupportedFriend = Unsupported; 119 } 120 121 // Implement isa/cast/dyncast/etc. 122 static bool classof(const Decl *D) { return classofKind(D->getKind()); } 123 static bool classof(const FriendDecl *D) { return true; } 124 static bool classofKind(Kind K) { return K == Decl::Friend; } 125 126 friend class ASTDeclReader; 127 friend class ASTDeclWriter; 128}; 129 130/// An iterator over the friend declarations of a class. 131class CXXRecordDecl::friend_iterator { 132 FriendDecl *Ptr; 133 134 friend class CXXRecordDecl; 135 explicit friend_iterator(FriendDecl *Ptr) : Ptr(Ptr) {} 136public: 137 friend_iterator() {} 138 139 typedef FriendDecl *value_type; 140 typedef FriendDecl *reference; 141 typedef FriendDecl *pointer; 142 typedef int difference_type; 143 typedef std::forward_iterator_tag iterator_category; 144 145 reference operator*() const { return Ptr; } 146 147 friend_iterator &operator++() { 148 assert(Ptr && "attempt to increment past end of friend list"); 149 Ptr = Ptr->getNextFriend(); 150 return *this; 151 } 152 153 friend_iterator operator++(int) { 154 friend_iterator tmp = *this; 155 ++*this; 156 return tmp; 157 } 158 159 bool operator==(const friend_iterator &Other) const { 160 return Ptr == Other.Ptr; 161 } 162 163 bool operator!=(const friend_iterator &Other) const { 164 return Ptr != Other.Ptr; 165 } 166 167 friend_iterator &operator+=(difference_type N) { 168 assert(N >= 0 && "cannot rewind a CXXRecordDecl::friend_iterator"); 169 while (N--) 170 ++*this; 171 return *this; 172 } 173 174 friend_iterator operator+(difference_type N) const { 175 friend_iterator tmp = *this; 176 tmp += N; 177 return tmp; 178 } 179}; 180 181inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_begin() const { 182 return friend_iterator(data().FirstFriend); 183} 184 185inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_end() const { 186 return friend_iterator(0); 187} 188 189inline void CXXRecordDecl::pushFriendDecl(FriendDecl *FD) { 190 assert(FD->NextFriend == 0 && "friend already has next friend?"); 191 FD->NextFriend = data().FirstFriend; 192 data().FirstFriend = FD; 193} 194 195} 196 197#endif 198