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 final 41 : public Decl, 42 private llvm::TrailingObjects<FriendDecl, TemplateParameterList *> { 43 virtual void anchor(); 44 public: 45 typedef llvm::PointerUnion<NamedDecl*,TypeSourceInfo*> FriendUnion; 46 47 private: 48 // The declaration that's a friend of this class. 49 FriendUnion Friend; 50 51 // A pointer to the next friend in the sequence. 52 LazyDeclPtr NextFriend; 53 54 // Location of the 'friend' specifier. 55 SourceLocation FriendLoc; 56 57 /// True if this 'friend' declaration is unsupported. Eventually we 58 /// will support every possible friend declaration, but for now we 59 /// silently ignore some and set this flag to authorize all access. 60 unsigned UnsupportedFriend : 1; 61 62 // The number of "outer" template parameter lists in non-templatic 63 // (currently unsupported) friend type declarations, such as 64 // template <class T> friend class A<T>::B; 65 unsigned NumTPLists : 31; 66 67 friend class CXXRecordDecl::friend_iterator; 68 friend class CXXRecordDecl; 69 70 FriendDecl(DeclContext *DC, SourceLocation L, FriendUnion Friend, 71 SourceLocation FriendL, 72 ArrayRef<TemplateParameterList*> FriendTypeTPLists) 73 : Decl(Decl::Friend, DC, L), 74 Friend(Friend), 75 NextFriend(), 76 FriendLoc(FriendL), 77 UnsupportedFriend(false), 78 NumTPLists(FriendTypeTPLists.size()) { 79 for (unsigned i = 0; i < NumTPLists; ++i) 80 getTrailingObjects<TemplateParameterList *>()[i] = FriendTypeTPLists[i]; 81 } 82 83 FriendDecl(EmptyShell Empty, unsigned NumFriendTypeTPLists) 84 : Decl(Decl::Friend, Empty), NextFriend(), 85 UnsupportedFriend(false), 86 NumTPLists(NumFriendTypeTPLists) { } 87 88 FriendDecl *getNextFriend() { 89 if (!NextFriend.isOffset()) 90 return cast_or_null<FriendDecl>(NextFriend.get(nullptr)); 91 return getNextFriendSlowCase(); 92 } 93 FriendDecl *getNextFriendSlowCase(); 94 95 public: 96 static FriendDecl *Create(ASTContext &C, DeclContext *DC, 97 SourceLocation L, FriendUnion Friend_, 98 SourceLocation FriendL, 99 ArrayRef<TemplateParameterList*> FriendTypeTPLists 100 = None); 101 static FriendDecl *CreateDeserialized(ASTContext &C, unsigned ID, 102 unsigned FriendTypeNumTPLists); 103 104 /// If this friend declaration names an (untemplated but possibly 105 /// dependent) type, return the type; otherwise return null. This 106 /// is used for elaborated-type-specifiers and, in C++0x, for 107 /// arbitrary friend type declarations. 108 TypeSourceInfo *getFriendType() const { 109 return Friend.dyn_cast<TypeSourceInfo*>(); 110 } 111 unsigned getFriendTypeNumTemplateParameterLists() const { 112 return NumTPLists; 113 } 114 TemplateParameterList *getFriendTypeTemplateParameterList(unsigned N) const { 115 assert(N < NumTPLists); 116 return getTrailingObjects<TemplateParameterList *>()[N]; 117 } 118 119 /// If this friend declaration doesn't name a type, return the inner 120 /// declaration. 121 NamedDecl *getFriendDecl() const { 122 return Friend.dyn_cast<NamedDecl*>(); 123 } 124 125 /// Retrieves the location of the 'friend' keyword. 126 SourceLocation getFriendLoc() const { 127 return FriendLoc; 128 } 129 130 /// Retrieves the source range for the friend declaration. 131 SourceRange getSourceRange() const override LLVM_READONLY { 132 if (NamedDecl *ND = getFriendDecl()) { 133 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) 134 return FD->getSourceRange(); 135 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 136 return FTD->getSourceRange(); 137 if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(ND)) 138 return CTD->getSourceRange(); 139 if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(ND)) { 140 if (DD->getOuterLocStart() != DD->getInnerLocStart()) 141 return DD->getSourceRange(); 142 } 143 return SourceRange(getFriendLoc(), ND->getLocEnd()); 144 } 145 else if (TypeSourceInfo *TInfo = getFriendType()) { 146 SourceLocation StartL = 147 (NumTPLists == 0) ? getFriendLoc() 148 : getTrailingObjects<TemplateParameterList *>()[0] 149 ->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 friend class ASTNodeImporter; 171 friend TrailingObjects; 172 }; 173 174 /// An iterator over the friend declarations of a class. 175 class CXXRecordDecl::friend_iterator { 176 FriendDecl *Ptr; 177 178 friend class CXXRecordDecl; 179 explicit friend_iterator(FriendDecl *Ptr) : Ptr(Ptr) {} 180 public: 181 friend_iterator() {} 182 183 typedef FriendDecl *value_type; 184 typedef FriendDecl *reference; 185 typedef FriendDecl *pointer; 186 typedef int difference_type; 187 typedef std::forward_iterator_tag iterator_category; 188 189 reference operator*() const { return Ptr; } 190 191 friend_iterator &operator++() { 192 assert(Ptr && "attempt to increment past end of friend list"); 193 Ptr = Ptr->getNextFriend(); 194 return *this; 195 } 196 197 friend_iterator operator++(int) { 198 friend_iterator tmp = *this; 199 ++*this; 200 return tmp; 201 } 202 203 bool operator==(const friend_iterator &Other) const { 204 return Ptr == Other.Ptr; 205 } 206 207 bool operator!=(const friend_iterator &Other) const { 208 return Ptr != Other.Ptr; 209 } 210 211 friend_iterator &operator+=(difference_type N) { 212 assert(N >= 0 && "cannot rewind a CXXRecordDecl::friend_iterator"); 213 while (N--) 214 ++*this; 215 return *this; 216 } 217 218 friend_iterator operator+(difference_type N) const { 219 friend_iterator tmp = *this; 220 tmp += N; 221 return tmp; 222 } 223 }; 224 225 inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_begin() const { 226 return friend_iterator(getFirstFriend()); 227 } 228 229 inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_end() const { 230 return friend_iterator(nullptr); 231 } 232 233 inline CXXRecordDecl::friend_range CXXRecordDecl::friends() const { 234 return friend_range(friend_begin(), friend_end()); 235 } 236 237 inline void CXXRecordDecl::pushFriendDecl(FriendDecl *FD) { 238 assert(!FD->NextFriend && "friend already has next friend?"); 239 FD->NextFriend = data().FirstFriend; 240 data().FirstFriend = FD; 241 } 242 243 } 244 245 #endif 246