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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 0 : 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 0 : 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 (FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
139 : return FD->getSourceRange();
140 : if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND))
141 : return FTD->getSourceRange();
142 : if (ClassTemplateDecl *CTD = dyn_cast<ClassTemplateDecl>(ND))
143 : return CTD->getSourceRange();
144 : if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(ND)) {
145 : if (DD->getOuterLocStart() != DD->getInnerLocStart())
146 : return DD->getSourceRange();
147 : }
148 : return SourceRange(getFriendLoc(), ND->getLocEnd());
149 : }
150 : else if (TypeSourceInfo *TInfo = getFriendType()) {
151 : SourceLocation StartL = (NumTPLists == 0)
152 : ? getFriendLoc()
153 : : getTPLists()[0]->getTemplateLoc();
154 : return SourceRange(StartL, TInfo->getTypeLoc().getEndLoc());
155 : }
156 : else
157 : return SourceRange(getFriendLoc(), getLocation());
158 : }
159 :
160 : /// Determines if this friend kind is unsupported.
161 : bool isUnsupportedFriend() const {
162 : return UnsupportedFriend;
163 : }
164 : void setUnsupportedFriend(bool Unsupported) {
165 : UnsupportedFriend = Unsupported;
166 : }
167 :
168 : // Implement isa/cast/dyncast/etc.
169 : static bool classof(const Decl *D) { return classofKind(D->getKind()); }
170 : static bool classofKind(Kind K) { return K == Decl::Friend; }
171 :
172 : friend class ASTDeclReader;
173 : friend class ASTDeclWriter;
174 : };
175 :
176 : /// An iterator over the friend declarations of a class.
177 : class CXXRecordDecl::friend_iterator {
178 : FriendDecl *Ptr;
179 :
180 : friend class CXXRecordDecl;
181 : explicit friend_iterator(FriendDecl *Ptr) : Ptr(Ptr) {}
182 : public:
183 : friend_iterator() {}
184 :
185 : typedef FriendDecl *value_type;
186 : typedef FriendDecl *reference;
187 : typedef FriendDecl *pointer;
188 : typedef int difference_type;
189 : typedef std::forward_iterator_tag iterator_category;
190 :
191 : reference operator*() const { return Ptr; }
192 :
193 : friend_iterator &operator++() {
194 : assert(Ptr && "attempt to increment past end of friend list");
195 : Ptr = Ptr->getNextFriend();
196 : return *this;
197 : }
198 :
199 : friend_iterator operator++(int) {
200 : friend_iterator tmp = *this;
201 : ++*this;
202 : return tmp;
203 : }
204 :
205 : bool operator==(const friend_iterator &Other) const {
206 : return Ptr == Other.Ptr;
207 : }
208 :
209 : bool operator!=(const friend_iterator &Other) const {
210 : return Ptr != Other.Ptr;
211 : }
212 :
213 : friend_iterator &operator+=(difference_type N) {
214 : assert(N >= 0 && "cannot rewind a CXXRecordDecl::friend_iterator");
215 : while (N--)
216 : ++*this;
217 : return *this;
218 : }
219 :
220 : friend_iterator operator+(difference_type N) const {
221 : friend_iterator tmp = *this;
222 : tmp += N;
223 : return tmp;
224 : }
225 : };
226 :
227 : inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_begin() const {
228 : return friend_iterator(getFirstFriend());
229 : }
230 :
231 : inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_end() const {
232 : return friend_iterator(nullptr);
233 : }
234 :
235 : inline CXXRecordDecl::friend_range CXXRecordDecl::friends() const {
236 : return friend_range(friend_begin(), friend_end());
237 : }
238 :
239 : inline void CXXRecordDecl::pushFriendDecl(FriendDecl *FD) {
240 : assert(!FD->NextFriend && "friend already has next friend?");
241 : FD->NextFriend = data().FirstFriend;
242 : data().FirstFriend = FD;
243 : }
244 :
245 : }
246 :
247 : #endif
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