DeclFriend.h source code [clang_source_code/include/clang/AST/DeclFriend.h]

1	//===- DeclFriend.h - Classes for C++ friend declarations -------- C++ --===//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	// This file defines the section of the AST representing C++ friend
10	// declarations.
11	//
12	//===----------------------------------------------------------------------===//
13
14	#ifndef LLVM_CLANG_AST_DECLFRIEND_H
15	#define LLVM_CLANG_AST_DECLFRIEND_H
16
17	#include "clang/AST/Decl.h"
18	#include "clang/AST/DeclBase.h"
19	#include "clang/AST/DeclCXX.h"
20	#include "clang/AST/DeclTemplate.h"
21	#include "clang/AST/ExternalASTSource.h"
22	#include "clang/AST/TypeLoc.h"
23	#include "clang/Basic/LLVM.h"
24	#include "clang/Basic/SourceLocation.h"
25	#include "llvm/ADT/ArrayRef.h"
26	#include "llvm/ADT/None.h"
27	#include "llvm/ADT/PointerUnion.h"
28	#include "llvm/Support/Casting.h"
29	#include "llvm/Support/Compiler.h"
30	#include "llvm/Support/TrailingObjects.h"
31	#include <cassert>
32	#include <iterator>
33
34	namespace clang {
35
36	class ASTContext;
37
38	/// FriendDecl - Represents the declaration of a friend entity,
39	/// which can be a function, a type, or a templated function or type.
40	/// For example:
41	///
42	/// @code
43	/// template <typename T> class A {
44	/// friend int foo(T);
45	/// friend class B;
46	/// friend T; // only in C++0x
47	/// template <typename U> friend class C;
48	/// template <typename U> friend A& operator+=(A&, const U&) { ... }
49	/// };
50	/// @endcode
51	///
52	/// The semantic context of a friend decl is its declaring class.
53	class FriendDecl final
54	: public Decl,
55	private llvm::TrailingObjects<FriendDecl, TemplateParameterList *> {
56	virtual void anchor();
57
58	public:
59	using FriendUnion = llvm::PointerUnion<NamedDecl , TypeSourceInfo >;
60
61	private:
62	friend class CXXRecordDecl;
63	friend class CXXRecordDecl::friend_iterator;
64
65	// The declaration that's a friend of this class.
66	FriendUnion Friend;
67
68	// A pointer to the next friend in the sequence.
69	LazyDeclPtr NextFriend;
70
71	// Location of the 'friend' specifier.
72	SourceLocation FriendLoc;
73
74	/// True if this 'friend' declaration is unsupported. Eventually we
75	/// will support every possible friend declaration, but for now we
76	/// silently ignore some and set this flag to authorize all access.
77	unsigned UnsupportedFriend : 1;
78
79	// The number of "outer" template parameter lists in non-templatic
80	// (currently unsupported) friend type declarations, such as
81	// template <class T> friend class A<T>::B;
82	unsigned NumTPLists : 31;
83
84	FriendDecl(DeclContext *DC, SourceLocation L, FriendUnion Friend,
85	SourceLocation FriendL,
86	ArrayRef<TemplateParameterList *> FriendTypeTPLists)
87	: Decl(Decl::Friend, DC, L), Friend(Friend), FriendLoc(FriendL),
88	UnsupportedFriend(false), NumTPLists(FriendTypeTPLists.size()) {
89	for (unsigned i = 0; i < NumTPLists; ++i)
90	getTrailingObjects<TemplateParameterList *>()[i] = FriendTypeTPLists[i];
91	}
92
93	FriendDecl(EmptyShell Empty, unsigned NumFriendTypeTPLists)
94	: Decl(Decl::Friend, Empty), UnsupportedFriend(false),
95	NumTPLists(NumFriendTypeTPLists) {}
96
97	FriendDecl *getNextFriend() {
98	if (!NextFriend.isOffset())
99	return cast_or_null<FriendDecl>(NextFriend.get(nullptr));
100	return getNextFriendSlowCase();
101	}
102
103	FriendDecl *getNextFriendSlowCase();
104
105	public:
106	friend class ASTDeclReader;
107	friend class ASTDeclWriter;
108	friend class ASTNodeImporter;
109	friend TrailingObjects;
110
111	static FriendDecl Create(ASTContext &C, DeclContext DC,
112	SourceLocation L, FriendUnion Friend_,
113	SourceLocation FriendL,
114	ArrayRef<TemplateParameterList*> FriendTypeTPLists
115	= None);
116	static FriendDecl *CreateDeserialized(ASTContext &C, unsigned ID,
117	unsigned FriendTypeNumTPLists);
118
119	/// If this friend declaration names an (untemplated but possibly
120	/// dependent) type, return the type; otherwise return null. This
121	/// is used for elaborated-type-specifiers and, in C++0x, for
122	/// arbitrary friend type declarations.
123	TypeSourceInfo *getFriendType() const {
124	return Friend.dyn_cast<TypeSourceInfo*>();
125	}
126
127	unsigned getFriendTypeNumTemplateParameterLists() const {
128	return NumTPLists;
129	}
130
131	TemplateParameterList *getFriendTypeTemplateParameterList(unsigned N) const {
132	assert(N < NumTPLists);
133	return getTrailingObjects<TemplateParameterList *>()[N];
134	}
135
136	/// If this friend declaration doesn't name a type, return the inner
137	/// declaration.
138	NamedDecl *getFriendDecl() const {
139	return Friend.dyn_cast<NamedDecl *>();
140	}
141
142	/// Retrieves the location of the 'friend' keyword.
143	SourceLocation getFriendLoc() const {
144	return FriendLoc;
145	}
146
147	/// Retrieves the source range for the friend declaration.
148	SourceRange getSourceRange() const override LLVM_READONLY {
149	if (NamedDecl *ND = getFriendDecl()) {
150	if (const auto *FD = dyn_cast<FunctionDecl>(ND))
151	return FD->getSourceRange();
152	if (const auto *FTD = dyn_cast<FunctionTemplateDecl>(ND))
153	return FTD->getSourceRange();
154	if (const auto *CTD = dyn_cast<ClassTemplateDecl>(ND))
155	return CTD->getSourceRange();
156	if (const auto *DD = dyn_cast<DeclaratorDecl>(ND)) {
157	if (DD->getOuterLocStart() != DD->getInnerLocStart())
158	return DD->getSourceRange();
159	}
160	return SourceRange(getFriendLoc(), ND->getEndLoc());
161	}
162	else if (TypeSourceInfo *TInfo = getFriendType()) {
163	SourceLocation StartL =
164	(NumTPLists == 0) ? getFriendLoc()
165	: getTrailingObjects<TemplateParameterList *>()[0]
166	->getTemplateLoc();
167	return SourceRange(StartL, TInfo->getTypeLoc().getEndLoc());
168	}
169	else
170	return SourceRange(getFriendLoc(), getLocation());
171	}
172
173	/// Determines if this friend kind is unsupported.
174	bool isUnsupportedFriend() const {
175	return UnsupportedFriend;
176	}
177	void setUnsupportedFriend(bool Unsupported) {
178	UnsupportedFriend = Unsupported;
179	}
180
181	// Implement isa/cast/dyncast/etc.
182	static bool classof(const Decl *D) { return classofKind(D->getKind()); }
183	static bool classofKind(Kind K) { return K == Decl::Friend; }
184	};
185
186	/// An iterator over the friend declarations of a class.
187	class CXXRecordDecl::friend_iterator {
188	friend class CXXRecordDecl;
189
190	FriendDecl *Ptr;
191
192	explicit friend_iterator(FriendDecl *Ptr) : Ptr(Ptr) {}
193
194	public:
195	friend_iterator() = default;
196
197	using value_type = FriendDecl *;
198	using reference = FriendDecl *;
199	using pointer = FriendDecl *;
200	using difference_type = int;
201	using iterator_category = std::forward_iterator_tag;
202
203	reference operator*() const { return Ptr; }
204
205	friend_iterator &operator++() {
206	(0) . __assert_fail ("Ptr && \"attempt to increment past end of friend list\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclFriend.h", 206, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(Ptr && "attempt to increment past end of friend list");
207	Ptr = Ptr->getNextFriend();
208	return *this;
209	}
210
211	friend_iterator operator++(int) {
212	friend_iterator tmp = *this;
213	++*this;
214	return tmp;
215	}
216
217	bool operator==(const friend_iterator &Other) const {
218	return Ptr == Other.Ptr;
219	}
220
221	bool operator!=(const friend_iterator &Other) const {
222	return Ptr != Other.Ptr;
223	}
224
225	friend_iterator &operator+=(difference_type N) {
226	(0) . __assert_fail ("N >= 0 && \"cannot rewind a CXXRecordDecl..friend_iterator\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclFriend.h", 226, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(N >= 0 && "cannot rewind a CXXRecordDecl::friend_iterator");
227	while (N--)
228	++*this;
229	return *this;
230	}
231
232	friend_iterator operator+(difference_type N) const {
233	friend_iterator tmp = *this;
234	tmp += N;
235	return tmp;
236	}
237	};
238
239	inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_begin() const {
240	return friend_iterator(getFirstFriend());
241	}
242
243	inline CXXRecordDecl::friend_iterator CXXRecordDecl::friend_end() const {
244	return friend_iterator(nullptr);
245	}
246
247	inline CXXRecordDecl::friend_range CXXRecordDecl::friends() const {
248	return friend_range(friend_begin(), friend_end());
249	}
250
251	inline void CXXRecordDecl::pushFriendDecl(FriendDecl *FD) {
252	(0) . __assert_fail ("!FD->NextFriend && \"friend already has next friend?\"", "/home/seafit/code_projects/clang_source/clang/include/clang/AST/DeclFriend.h", 252, __PRETTY_FUNCTION__))" file_link="../../../../include/assert.h.html#88" macro="true">assert(!FD->NextFriend && "friend already has next friend?");
253	FD->NextFriend = data().FirstFriend;
254	data().FirstFriend = FD;
255	}
256
257	} // namespace clang
258
259	#endif // LLVM_CLANG_AST_DECLFRIEND_H
260

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