1/*
2 * Copyright (C) 2005-2019 Apple Inc. All rights reserved.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB. If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21#pragma once
22
23#include <wtf/Platform.h>
24
25#if USE(CF) || defined(__OBJC__)
26
27#include <wtf/HashTraits.h>
28#include <algorithm>
29#include <cstddef>
30
31#if USE(CF)
32#include <CoreFoundation/CoreFoundation.h>
33#endif
34
35#ifdef __OBJC__
36#import <Foundation/Foundation.h>
37#endif
38
39#ifndef CF_BRIDGED_TYPE
40#define CF_BRIDGED_TYPE(T)
41#endif
42
43#ifndef CF_RELEASES_ARGUMENT
44#define CF_RELEASES_ARGUMENT
45#endif
46
47#ifndef NS_RELEASES_ARGUMENT
48#define NS_RELEASES_ARGUMENT
49#endif
50
51namespace WTF {
52
53// Unlike most most of our smart pointers, RetainPtr can take either the pointer type or the pointed-to type,
54// so both RetainPtr<NSDictionary> and RetainPtr<CFDictionaryRef> will work.
55
56template<typename T> class RetainPtr;
57
58template<typename T> RetainPtr<T> adoptCF(T CF_RELEASES_ARGUMENT) WARN_UNUSED_RETURN;
59#ifdef __OBJC__
60template<typename T> RetainPtr<typename RetainPtr<T>::HelperPtrType> adoptNS(T NS_RELEASES_ARGUMENT) WARN_UNUSED_RETURN;
61#endif
62
63template<typename T> class RetainPtr {
64public:
65 typedef typename std::remove_pointer<T>::type ValueType;
66 typedef ValueType* PtrType;
67 typedef CFTypeRef StorageType;
68
69#ifdef __OBJC__
70 typedef typename std::conditional<std::is_convertible<T, id>::value && !std::is_same<T, id>::value, typename std::remove_pointer<T>::type, T>::type HelperPtrType;
71#else
72 typedef T HelperPtrType;
73#endif
74
75 RetainPtr() : m_ptr(nullptr) { }
76 RetainPtr(PtrType ptr) : m_ptr(toStorageType(ptr)) { if (m_ptr) CFRetain(m_ptr); }
77
78 RetainPtr(const RetainPtr& o) : m_ptr(o.m_ptr) { if (StorageType ptr = m_ptr) CFRetain(ptr); }
79
80 RetainPtr(RetainPtr&& o) : m_ptr(toStorageType(o.leakRef())) { }
81 template<typename U> RetainPtr(RetainPtr<U>&& o) : m_ptr(toStorageType(o.leakRef())) { }
82
83 // Hash table deleted values, which are only constructed and never copied or destroyed.
84 RetainPtr(HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) { }
85 bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); }
86
87 ~RetainPtr();
88
89 template<typename U> RetainPtr(const RetainPtr<U>&);
90
91 void clear();
92 PtrType leakRef() WARN_UNUSED_RETURN;
93 PtrType autorelease();
94#ifdef __OBJC__
95 id bridgingAutorelease();
96#endif
97
98 PtrType get() const { return fromStorageType(m_ptr); }
99 PtrType operator->() const { return fromStorageType(m_ptr); }
100 explicit operator PtrType() const { return fromStorageType(m_ptr); }
101 explicit operator bool() const { return m_ptr; }
102
103 bool operator!() const { return !m_ptr; }
104
105 // This conversion operator allows implicit conversion to bool but not to other integer types.
106 typedef StorageType RetainPtr::*UnspecifiedBoolType;
107 operator UnspecifiedBoolType() const { return m_ptr ? &RetainPtr::m_ptr : nullptr; }
108
109 RetainPtr& operator=(const RetainPtr&);
110 template<typename U> RetainPtr& operator=(const RetainPtr<U>&);
111 RetainPtr& operator=(PtrType);
112 template<typename U> RetainPtr& operator=(U*);
113
114 RetainPtr& operator=(RetainPtr&&);
115 template<typename U> RetainPtr& operator=(RetainPtr<U>&&);
116
117 void swap(RetainPtr&);
118
119 template<typename U> friend RetainPtr<U> adoptCF(U CF_RELEASES_ARGUMENT) WARN_UNUSED_RETURN;
120#ifdef __OBJC__
121 template<typename U> friend RetainPtr<typename RetainPtr<U>::HelperPtrType> adoptNS(U NS_RELEASES_ARGUMENT) WARN_UNUSED_RETURN;
122#endif
123
124private:
125 enum AdoptTag { Adopt };
126 RetainPtr(PtrType ptr, AdoptTag) : m_ptr(toStorageType(ptr)) { }
127
128 static PtrType hashTableDeletedValue() { return reinterpret_cast<PtrType>(-1); }
129
130#ifdef __OBJC__
131 template<typename U>
132 typename std::enable_if<std::is_convertible<U, id>::value, PtrType>::type
133 fromStorageTypeHelper(StorageType ptr) const
134 {
135 return (__bridge PtrType)const_cast<CF_BRIDGED_TYPE(id) void*>(ptr);
136 }
137
138 template<typename U>
139 typename std::enable_if<!std::is_convertible<U, id>::value, PtrType>::type
140 fromStorageTypeHelper(StorageType ptr) const
141 {
142 return (PtrType)const_cast<CF_BRIDGED_TYPE(id) void*>(ptr);
143 }
144
145 PtrType fromStorageType(StorageType ptr) const { return fromStorageTypeHelper<PtrType>(ptr); }
146 StorageType toStorageType(id ptr) const { return (__bridge StorageType)ptr; }
147 StorageType toStorageType(CFTypeRef ptr) const { return (StorageType)ptr; }
148#else
149 PtrType fromStorageType(StorageType ptr) const
150 {
151 return (PtrType)const_cast<CF_BRIDGED_TYPE(id) void*>(ptr);
152 }
153 StorageType toStorageType(PtrType ptr) const { return (StorageType)ptr; }
154#endif
155
156#ifdef __OBJC__
157 template<typename U> std::enable_if_t<std::is_convertible<U, id>::value, PtrType> autoreleaseHelper();
158 template<typename U> std::enable_if_t<!std::is_convertible<U, id>::value, PtrType> autoreleaseHelper();
159#endif
160
161 StorageType m_ptr;
162};
163
164// Helper function for creating a RetainPtr using template argument deduction.
165template<typename T> RetainPtr<typename RetainPtr<T>::HelperPtrType> retainPtr(T) WARN_UNUSED_RETURN;
166
167template<typename T> inline RetainPtr<T>::~RetainPtr()
168{
169 if (StorageType ptr = std::exchange(m_ptr, nullptr))
170 CFRelease(ptr);
171}
172
173template<typename T> template<typename U> inline RetainPtr<T>::RetainPtr(const RetainPtr<U>& o)
174 : m_ptr(toStorageType(o.get()))
175{
176 if (StorageType ptr = m_ptr)
177 CFRetain(ptr);
178}
179
180template<typename T> inline void RetainPtr<T>::clear()
181{
182 if (StorageType ptr = std::exchange(m_ptr, nullptr))
183 CFRelease(ptr);
184}
185
186template<typename T> inline auto RetainPtr<T>::leakRef() -> PtrType
187{
188 return fromStorageType(std::exchange(m_ptr, nullptr));
189}
190
191#ifndef __OBJC__
192
193template<typename T> inline auto RetainPtr<T>::autorelease() -> PtrType
194{
195 if (m_ptr)
196 CFAutorelease(m_ptr);
197 return leakRef();
198}
199
200#else
201
202template<typename T> template<typename U> inline auto RetainPtr<T>::autoreleaseHelper() -> std::enable_if_t<std::is_convertible<U, id>::value, PtrType>
203{
204 return CFBridgingRelease(std::exchange(m_ptr, nullptr));
205}
206
207template<typename T> template<typename U> inline auto RetainPtr<T>::autoreleaseHelper() -> std::enable_if_t<!std::is_convertible<U, id>::value, PtrType>
208{
209 if (m_ptr)
210 CFAutorelease(m_ptr);
211 return leakRef();
212}
213
214template<typename T> inline auto RetainPtr<T>::autorelease() -> PtrType
215{
216 return autoreleaseHelper<PtrType>();
217}
218
219// FIXME: It would be nice if we could base the return type on the type that is toll-free bridged with T rather than using id.
220template<typename T> inline id RetainPtr<T>::bridgingAutorelease()
221{
222 static_assert((!std::is_convertible<PtrType, id>::value), "Don't use bridgingAutorelease for Objective-C pointer types.");
223 return CFBridgingRelease(leakRef());
224}
225
226#endif
227
228template<typename T> inline RetainPtr<T>& RetainPtr<T>::operator=(const RetainPtr& o)
229{
230 RetainPtr ptr = o;
231 swap(ptr);
232 return *this;
233}
234
235template<typename T> template<typename U> inline RetainPtr<T>& RetainPtr<T>::operator=(const RetainPtr<U>& o)
236{
237 RetainPtr ptr = o;
238 swap(ptr);
239 return *this;
240}
241
242template<typename T> inline RetainPtr<T>& RetainPtr<T>::operator=(PtrType optr)
243{
244 RetainPtr ptr = optr;
245 swap(ptr);
246 return *this;
247}
248
249template<typename T> template<typename U> inline RetainPtr<T>& RetainPtr<T>::operator=(U* optr)
250{
251 RetainPtr ptr = optr;
252 swap(ptr);
253 return *this;
254}
255
256template<typename T> inline RetainPtr<T>& RetainPtr<T>::operator=(RetainPtr&& o)
257{
258 RetainPtr ptr = WTFMove(o);
259 swap(ptr);
260 return *this;
261}
262
263template<typename T> template<typename U> inline RetainPtr<T>& RetainPtr<T>::operator=(RetainPtr<U>&& o)
264{
265 RetainPtr ptr = WTFMove(o);
266 swap(ptr);
267 return *this;
268}
269
270template<typename T> inline void RetainPtr<T>::swap(RetainPtr& o)
271{
272 std::swap(m_ptr, o.m_ptr);
273}
274
275template<typename T> inline void swap(RetainPtr<T>& a, RetainPtr<T>& b)
276{
277 a.swap(b);
278}
279
280template<typename T, typename U> inline bool operator==(const RetainPtr<T>& a, const RetainPtr<U>& b)
281{
282 return a.get() == b.get();
283}
284
285template<typename T, typename U> inline bool operator==(const RetainPtr<T>& a, U* b)
286{
287 return a.get() == b;
288}
289
290template<typename T, typename U> inline bool operator==(T* a, const RetainPtr<U>& b)
291{
292 return a == b.get();
293}
294
295template<typename T, typename U> inline bool operator!=(const RetainPtr<T>& a, const RetainPtr<U>& b)
296{
297 return a.get() != b.get();
298}
299
300template<typename T, typename U> inline bool operator!=(const RetainPtr<T>& a, U* b)
301{
302 return a.get() != b;
303}
304
305template<typename T, typename U> inline bool operator!=(T* a, const RetainPtr<U>& b)
306{
307 return a != b.get();
308}
309
310template<typename T> inline RetainPtr<T> adoptCF(T CF_RELEASES_ARGUMENT ptr)
311{
312#ifdef __OBJC__
313 static_assert((!std::is_convertible<T, id>::value), "Don't use adoptCF with Objective-C pointer types, use adoptNS.");
314#endif
315 return RetainPtr<T>(ptr, RetainPtr<T>::Adopt);
316}
317
318#ifdef __OBJC__
319template<typename T> inline RetainPtr<typename RetainPtr<T>::HelperPtrType> adoptNS(T NS_RELEASES_ARGUMENT ptr)
320{
321#if __has_feature(objc_arc)
322 return ptr;
323#elif defined(OBJC_NO_GC)
324 return RetainPtr<typename RetainPtr<T>::HelperPtrType>(ptr, RetainPtr<typename RetainPtr<T>::HelperPtrType>::Adopt);
325#else
326 RetainPtr<typename RetainPtr<T>::HelperPtrType> result = ptr;
327 [ptr release];
328 return result;
329#endif
330}
331#endif
332
333template<typename T> inline RetainPtr<typename RetainPtr<T>::HelperPtrType> retainPtr(T ptr)
334{
335 return ptr;
336}
337
338template <typename T> struct IsSmartPtr<RetainPtr<T>> {
339 static constexpr bool value = true;
340};
341
342template<typename P> struct HashTraits<RetainPtr<P>> : SimpleClassHashTraits<RetainPtr<P>> {
343};
344
345template<typename P> struct DefaultHash<RetainPtr<P>> {
346 typedef PtrHash<RetainPtr<P>> Hash;
347};
348
349template <typename P>
350struct RetainPtrObjectHashTraits : SimpleClassHashTraits<RetainPtr<P>> {
351 static const RetainPtr<P>& emptyValue()
352 {
353 static RetainPtr<P>& null = *(new RetainPtr<P>);
354 return null;
355 }
356};
357
358template <typename P>
359struct RetainPtrObjectHash {
360 static unsigned hash(const RetainPtr<P>& o)
361 {
362 ASSERT_WITH_MESSAGE(o.get(), "attempt to use null RetainPtr in HashTable");
363 return static_cast<unsigned>(CFHash(o.get()));
364 }
365 static bool equal(const RetainPtr<P>& a, const RetainPtr<P>& b)
366 {
367 return CFEqual(a.get(), b.get());
368 }
369 static constexpr bool safeToCompareToEmptyOrDeleted = false;
370};
371
372inline bool safeCFEqual(CFTypeRef a, CFTypeRef b)
373{
374 return (!a && !b) || (a && b && CFEqual(a, b));
375}
376
377inline CFHashCode safeCFHash(CFTypeRef a)
378{
379 return a ? CFHash(a) : 0;
380}
381
382#ifdef __OBJC__
383template<typename T> T* dynamic_objc_cast(id object)
384{
385 if ([object isKindOfClass:[T class]])
386 return (T *)object;
387
388 return nil;
389}
390#endif
391
392} // namespace WTF
393
394using WTF::RetainPtr;
395using WTF::adoptCF;
396using WTF::retainPtr;
397
398#ifdef __OBJC__
399using WTF::adoptNS;
400using WTF::dynamic_objc_cast;
401#endif
402
403#endif // USE(CF) || defined(__OBJC__)
404