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 #include "llvm/Support/Compiler.h" 20 21 namespace clang { 22 23 /// FriendDecl - Represents the declaration of a friend entity, 24 /// which can be a function, a type, or a templated function or type. 25 // For example: 26 /// 27 /// @code 28 /// template <typename T> class A { 29 /// friend int foo(T); 30 /// friend class B; 31 /// friend T; // only in C++0x 32 /// template <typename U> friend class C; 33 /// template <typename U> friend A& operator+=(A&, const U&) { ... } 34 /// }; 35 /// @endcode 36 /// 37 /// The semantic context of a friend decl is its declaring class. 38 class FriendDecl : public Decl { 39 virtual void anchor(); 40 public: 41 typedef llvm::PointerUnion<NamedDecl*,TypeSourceInfo*> FriendUnion; 42 43 private: 44 // The declaration that's a friend of this class. 45 FriendUnion Friend; 46 47 // A pointer to the next friend in the sequence. 48 LazyDeclPtr NextFriend; 49 50 // Location of the 'friend' specifier. 51 SourceLocation FriendLoc; 52 53 /// True if this 'friend' declaration is unsupported. Eventually we 54 /// will support every possible friend declaration, but for now we 55 /// silently ignore some and set this flag to authorize all access. 56 bool UnsupportedFriend; 57 58 friend class CXXRecordDecl::friend_iterator; 59 friend class CXXRecordDecl; 60 61 FriendDecl(DeclContext *DC, SourceLocation L, FriendUnion Friend, 62 SourceLocation FriendL) 63 : Decl(Decl::Friend, DC, L), 64 Friend(Friend), 65 NextFriend(), 66 FriendLoc(FriendL), 67 UnsupportedFriend(false) { 68 } 69 70 explicit FriendDecl(EmptyShell Empty) 71 : Decl(Decl::Friend, Empty), NextFriend() { } 72 73 FriendDecl *getNextFriend() { 74 return cast_or_null<FriendDecl>( 75 NextFriend.get(getASTContext().getExternalSource())); 76 } 77 78 public: 79 static FriendDecl *Create(ASTContext &C, DeclContext *DC, 80 SourceLocation L, FriendUnion Friend_, 81 SourceLocation FriendL); 82 static FriendDecl *CreateDeserialized(ASTContext &C, unsigned ID); 83 84 /// If this friend declaration names an (untemplated but possibly 85 /// dependent) type, return the type; otherwise return null. This 86 /// is used for elaborated-type-specifiers and, in C++0x, for 87 /// arbitrary friend type declarations. 88 TypeSourceInfo *getFriendType() const { 89 return Friend.dyn_cast<TypeSourceInfo*>(); 90 } 91 92 /// If this friend declaration doesn't name a type, return the inner 93 /// declaration. 94 NamedDecl *getFriendDecl() const { 95 return Friend.dyn_cast<NamedDecl*>(); 96 } 97 98 /// Retrieves the location of the 'friend' keyword. 99 SourceLocation getFriendLoc() const { 100 return FriendLoc; 101 } 102 103 /// Retrieves the source range for the friend declaration. 104 SourceRange getSourceRange() const LLVM_READONLY { 105 /* FIXME: consider the case of templates wrt start of range. */ 106 if (NamedDecl *ND = getFriendDecl()) 107 return SourceRange(getFriendLoc(), ND->getLocEnd()); 108 else if (TypeSourceInfo *TInfo = getFriendType()) 109 return SourceRange(getFriendLoc(), TInfo->getTypeLoc().getEndLoc()); 110 else 111 return SourceRange(getFriendLoc(), getLocation()); 112 } 113 114 /// Determines if this friend kind is unsupported. 115 bool isUnsupportedFriend() const { 116 return UnsupportedFriend; 117 } 118 void setUnsupportedFriend(bool Unsupported) { 119 UnsupportedFriend = Unsupported; 120 } 121 122 // Implement isa/cast/dyncast/etc. 123 static bool classof(const Decl *D) { return classofKind(D->getKind()); } 124 static bool classof(const FriendDecl *D) { return true; } 125 static bool classofKind(Kind K) { return K == Decl::Friend; } 126 127 friend class ASTDeclReader; 128 friend class ASTDeclWriter; 129 }; 130 131 /// An iterator over the friend declarations of a class. 132 class CXXRecordDecl::friend_iterator { 133 FriendDecl *Ptr; 134 135 friend class CXXRecordDecl; 136 explicit friend_iterator(FriendDecl *Ptr) : Ptr(Ptr) {} 137 public: 138 friend_iterator() {} 139 140 typedef FriendDecl *value_type; 141 typedef FriendDecl *reference; 142 typedef FriendDecl *pointer; 143 typedef int difference_type; 144 typedef std::forward_iterator_tag iterator_category; 145 146 reference operator*() const { return Ptr; } 147 148 friend_iterator &operator++() { 149 assert(Ptr && "attempt to increment past end of friend list"); 150 Ptr = Ptr->getNextFriend(); 151 return *this; 152 } 153 154 friend_iterator operator++(int) { 155 friend_iterator tmp = *this; 156 ++*this; 157 return tmp; 158 } 159 160 bool operator==(const friend_iterator &Other) const { 161 return Ptr == Other.Ptr; 162 } 163 164 bool operator!=(const friend_iterator &Other) const { 165 return Ptr != Other.Ptr; 166 } 167 168 friend_iterator &operator+=(difference_type N) { 169 assert(N >= 0 && "cannot rewind a CXXRecordDecl::friend_iterator"); 170 while (N--) 171 ++*this; 172 return *this; 173 } 174 175 friend_iterator operator+(difference_type N) const { 176 friend_iterator tmp = *this; 177 tmp += N; 178 return tmp; 179 } 180 }; 181 182 inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_begin() const { 183 return friend_iterator(data().FirstFriend); 184 } 185 186 inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_end() const { 187 return friend_iterator(0); 188 } 189 190 inline void CXXRecordDecl::pushFriendDecl(FriendDecl *FD) { 191 assert(FD->NextFriend == 0 && "friend already has next friend?"); 192 FD->NextFriend = data().FirstFriend; 193 data().FirstFriend = FD; 194 } 195 196 } 197 198 #endif 199
