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 "clang/AST/DeclTemplate.h" 20 #include "clang/AST/TypeLoc.h" 21 #include "llvm/Support/Compiler.h" 22 23 namespace clang { 24 25 /// FriendDecl - Represents the declaration of a friend entity, 26 /// which can be a function, a type, or a templated function or type. 27 // For example: 28 /// 29 /// @code 30 /// template <typename T> class A { 31 /// friend int foo(T); 32 /// friend class B; 33 /// friend T; // only in C++0x 34 /// template <typename U> friend class C; 35 /// template <typename U> friend A& operator+=(A&, const U&) { ... } 36 /// }; 37 /// @endcode 38 /// 39 /// The semantic context of a friend decl is its declaring class. 40 class FriendDecl : public Decl { 41 virtual void anchor(); 42 public: 43 typedef llvm::PointerUnion<NamedDecl*,TypeSourceInfo*> FriendUnion; 44 45 private: 46 // The declaration that's a friend of this class. 47 FriendUnion Friend; 48 49 // A pointer to the next friend in the sequence. 50 LazyDeclPtr NextFriend; 51 52 // Location of the 'friend' specifier. 53 SourceLocation FriendLoc; 54 55 /// True if this 'friend' declaration is unsupported. Eventually we 56 /// will support every possible friend declaration, but for now we 57 /// silently ignore some and set this flag to authorize all access. 58 bool UnsupportedFriend : 1; 59 60 // The number of "outer" template parameter lists in non-templatic 61 // (currently unsupported) friend type declarations, such as 62 // template <class T> friend class A<T>::B; 63 unsigned NumTPLists : 31; 64 65 // The tail-allocated friend type template parameter lists (if any). 66 TemplateParameterList* const *getTPLists() const { 67 return reinterpret_cast<TemplateParameterList* const *>(this + 1); 68 } 69 TemplateParameterList **getTPLists() { 70 return reinterpret_cast<TemplateParameterList**>(this + 1); 71 } 72 73 friend class CXXRecordDecl::friend_iterator; 74 friend class CXXRecordDecl; 75 76 FriendDecl(DeclContext *DC, SourceLocation L, FriendUnion Friend, 77 SourceLocation FriendL, 78 ArrayRef<TemplateParameterList*> FriendTypeTPLists) 79 : Decl(Decl::Friend, DC, L), 80 Friend(Friend), 81 NextFriend(), 82 FriendLoc(FriendL), 83 UnsupportedFriend(false), 84 NumTPLists(FriendTypeTPLists.size()) { 85 for (unsigned i = 0; i < NumTPLists; ++i) 86 getTPLists()[i] = FriendTypeTPLists[i]; 87 } 88 89 FriendDecl(EmptyShell Empty, unsigned NumFriendTypeTPLists) 90 : Decl(Decl::Friend, Empty), NextFriend(), 91 NumTPLists(NumFriendTypeTPLists) { } 92 93 FriendDecl *getNextFriend() { 94 if (!NextFriend.isOffset()) 95 return cast_or_null<FriendDecl>(NextFriend.get(nullptr)); 96 return getNextFriendSlowCase(); 97 } 98 FriendDecl *getNextFriendSlowCase(); 99 100 public: 101 static FriendDecl *Create(ASTContext &C, DeclContext *DC, 102 SourceLocation L, FriendUnion Friend_, 103 SourceLocation FriendL, 104 ArrayRef<TemplateParameterList*> FriendTypeTPLists 105 = None); 106 static FriendDecl *CreateDeserialized(ASTContext &C, unsigned ID, 107 unsigned FriendTypeNumTPLists); 108 109 /// If this friend declaration names an (untemplated but possibly 110 /// dependent) type, return the type; otherwise return null. This 111 /// is used for elaborated-type-specifiers and, in C++0x, for 112 /// arbitrary friend type declarations. 113 TypeSourceInfo *getFriendType() const { 114 return Friend.dyn_cast<TypeSourceInfo*>(); 115 } 116 unsigned getFriendTypeNumTemplateParameterLists() const { 117 return NumTPLists; 118 } 119 TemplateParameterList *getFriendTypeTemplateParameterList(unsigned N) const { 120 assert(N < NumTPLists); 121 return getTPLists()[N]; 122 } 123 124 /// If this friend declaration doesn't name a type, return the inner 125 /// declaration. 126 NamedDecl *getFriendDecl() const { 127 return Friend.dyn_cast<NamedDecl*>(); 128 } 129 130 /// Retrieves the location of the 'friend' keyword. 131 SourceLocation getFriendLoc() const { 132 return FriendLoc; 133 } 134 135 /// Retrieves the source range for the friend declaration. 136 SourceRange getSourceRange() const override LLVM_READONLY { 137 if (NamedDecl *ND = getFriendDecl()) { 138 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 139 return FTD->getSourceRange(); 140 if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(ND)) { 141 if (DD->getOuterLocStart() != DD->getInnerLocStart()) 142 return DD->getSourceRange(); 143 } 144 return SourceRange(getFriendLoc(), ND->getLocEnd()); 145 } 146 else if (TypeSourceInfo *TInfo = getFriendType()) { 147 SourceLocation StartL = (NumTPLists == 0) 148 ? getFriendLoc() 149 : getTPLists()[0]->getTemplateLoc(); 150 return SourceRange(StartL, TInfo->getTypeLoc().getEndLoc()); 151 } 152 else 153 return SourceRange(getFriendLoc(), getLocation()); 154 } 155 156 /// Determines if this friend kind is unsupported. 157 bool isUnsupportedFriend() const { 158 return UnsupportedFriend; 159 } 160 void setUnsupportedFriend(bool Unsupported) { 161 UnsupportedFriend = Unsupported; 162 } 163 164 // Implement isa/cast/dyncast/etc. 165 static bool classof(const Decl *D) { return classofKind(D->getKind()); } 166 static bool classofKind(Kind K) { return K == Decl::Friend; } 167 168 friend class ASTDeclReader; 169 friend class ASTDeclWriter; 170 }; 171 172 /// An iterator over the friend declarations of a class. 173 class CXXRecordDecl::friend_iterator { 174 FriendDecl *Ptr; 175 176 friend class CXXRecordDecl; 177 explicit friend_iterator(FriendDecl *Ptr) : Ptr(Ptr) {} 178 public: 179 friend_iterator() {} 180 181 typedef FriendDecl *value_type; 182 typedef FriendDecl *reference; 183 typedef FriendDecl *pointer; 184 typedef int difference_type; 185 typedef std::forward_iterator_tag iterator_category; 186 187 reference operator*() const { return Ptr; } 188 189 friend_iterator &operator++() { 190 assert(Ptr && "attempt to increment past end of friend list"); 191 Ptr = Ptr->getNextFriend(); 192 return *this; 193 } 194 195 friend_iterator operator++(int) { 196 friend_iterator tmp = *this; 197 ++*this; 198 return tmp; 199 } 200 201 bool operator==(const friend_iterator &Other) const { 202 return Ptr == Other.Ptr; 203 } 204 205 bool operator!=(const friend_iterator &Other) const { 206 return Ptr != Other.Ptr; 207 } 208 209 friend_iterator &operator+=(difference_type N) { 210 assert(N >= 0 && "cannot rewind a CXXRecordDecl::friend_iterator"); 211 while (N--) 212 ++*this; 213 return *this; 214 } 215 216 friend_iterator operator+(difference_type N) const { 217 friend_iterator tmp = *this; 218 tmp += N; 219 return tmp; 220 } 221 }; 222 223 inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_begin() const { 224 return friend_iterator(getFirstFriend()); 225 } 226 227 inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_end() const { 228 return friend_iterator(nullptr); 229 } 230 231 inline CXXRecordDecl::friend_range CXXRecordDecl::friends() const { 232 return friend_range(friend_begin(), friend_end()); 233 } 234 235 inline void CXXRecordDecl::pushFriendDecl(FriendDecl *FD) { 236 assert(!FD->NextFriend && "friend already has next friend?"); 237 FD->NextFriend = data().FirstFriend; 238 data().FirstFriend = FD; 239 } 240 241 } 242 243 #endif 244