darling-WTF/wtf/RetainPtr.h
2023-04-24 20:14:26 -07:00

406 lines
12 KiB
Objective-C

/*
* Copyright (C) 2005-2019 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#pragma once
#include <wtf/Platform.h>
#if USE(CF) || defined(__OBJC__)
#include <wtf/HashTraits.h>
#include <algorithm>
#include <cstddef>
#if USE(CF)
#include <CoreFoundation/CoreFoundation.h>
#endif
#ifdef __OBJC__
#import <Foundation/Foundation.h>
#endif
#ifndef CF_BRIDGED_TYPE
#define CF_BRIDGED_TYPE(T)
#endif
#ifndef CF_RELEASES_ARGUMENT
#define CF_RELEASES_ARGUMENT
#endif
#ifndef NS_RELEASES_ARGUMENT
#define NS_RELEASES_ARGUMENT
#endif
#ifndef __OBJC__
typedef struct objc_object *id;
#endif
namespace WTF {
// Unlike most most of our smart pointers, RetainPtr can take either the pointer type or the pointed-to type,
// so both RetainPtr<NSDictionary> and RetainPtr<CFDictionaryRef> will work.
template<typename T> class RetainPtr;
template<typename T> RetainPtr<T> adoptCF(T CF_RELEASES_ARGUMENT) WARN_UNUSED_RETURN;
#ifdef __OBJC__
template<typename T> RetainPtr<typename RetainPtr<T>::HelperPtrType> adoptNS(T NS_RELEASES_ARGUMENT) WARN_UNUSED_RETURN;
#endif
template<typename T> class RetainPtr {
public:
typedef typename std::remove_pointer<T>::type ValueType;
typedef ValueType* PtrType;
typedef CFTypeRef StorageType;
#ifdef __OBJC__
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;
#else
typedef T HelperPtrType;
#endif
RetainPtr() : m_ptr(nullptr) { }
RetainPtr(PtrType ptr) : m_ptr(toStorageType(ptr)) { if (m_ptr) CFRetain(m_ptr); }
RetainPtr(const RetainPtr& o) : m_ptr(o.m_ptr) { if (StorageType ptr = m_ptr) CFRetain(ptr); }
RetainPtr(RetainPtr&& o) : m_ptr(toStorageType(o.leakRef())) { }
template<typename U> RetainPtr(RetainPtr<U>&& o) : m_ptr(toStorageType(o.leakRef())) { }
// Hash table deleted values, which are only constructed and never copied or destroyed.
RetainPtr(HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) { }
bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); }
~RetainPtr();
template<typename U> RetainPtr(const RetainPtr<U>&);
void clear();
PtrType leakRef() WARN_UNUSED_RETURN;
PtrType autorelease();
#ifdef __OBJC__
id bridgingAutorelease();
#endif
PtrType get() const { return fromStorageType(m_ptr); }
PtrType operator->() const { return fromStorageType(m_ptr); }
explicit operator PtrType() const { return fromStorageType(m_ptr); }
explicit operator bool() const { return m_ptr; }
bool operator!() const { return !m_ptr; }
// This conversion operator allows implicit conversion to bool but not to other integer types.
typedef StorageType RetainPtr::*UnspecifiedBoolType;
operator UnspecifiedBoolType() const { return m_ptr ? &RetainPtr::m_ptr : nullptr; }
RetainPtr& operator=(const RetainPtr&);
template<typename U> RetainPtr& operator=(const RetainPtr<U>&);
RetainPtr& operator=(PtrType);
template<typename U> RetainPtr& operator=(U*);
RetainPtr& operator=(RetainPtr&&);
template<typename U> RetainPtr& operator=(RetainPtr<U>&&);
void swap(RetainPtr&);
template<typename U> friend RetainPtr<U> adoptCF(U CF_RELEASES_ARGUMENT) WARN_UNUSED_RETURN;
#ifdef __OBJC__
template<typename U> friend RetainPtr<typename RetainPtr<U>::HelperPtrType> adoptNS(U NS_RELEASES_ARGUMENT) WARN_UNUSED_RETURN;
#endif
private:
enum AdoptTag { Adopt };
RetainPtr(PtrType ptr, AdoptTag) : m_ptr(toStorageType(ptr)) { }
static PtrType hashTableDeletedValue() { return reinterpret_cast<PtrType>(-1); }
#ifdef __OBJC__
template<typename U>
typename std::enable_if<std::is_convertible<U, id>::value, PtrType>::type
fromStorageTypeHelper(StorageType ptr) const
{
return (__bridge PtrType)const_cast<CF_BRIDGED_TYPE(id) void*>(ptr);
}
template<typename U>
typename std::enable_if<!std::is_convertible<U, id>::value, PtrType>::type
fromStorageTypeHelper(StorageType ptr) const
{
return (PtrType)const_cast<CF_BRIDGED_TYPE(id) void*>(ptr);
}
PtrType fromStorageType(StorageType ptr) const { return fromStorageTypeHelper<PtrType>(ptr); }
StorageType toStorageType(id ptr) const { return (__bridge StorageType)ptr; }
StorageType toStorageType(CFTypeRef ptr) const { return (StorageType)ptr; }
#else
PtrType fromStorageType(StorageType ptr) const
{
return (PtrType)const_cast<CF_BRIDGED_TYPE(id) void*>(ptr);
}
StorageType toStorageType(PtrType ptr) const { return (StorageType)ptr; }
#endif
#ifdef __OBJC__
template<typename U> std::enable_if_t<std::is_convertible<U, id>::value, PtrType> autoreleaseHelper();
template<typename U> std::enable_if_t<!std::is_convertible<U, id>::value, PtrType> autoreleaseHelper();
#endif
StorageType m_ptr;
};
// Helper function for creating a RetainPtr using template argument deduction.
template<typename T> RetainPtr<typename RetainPtr<T>::HelperPtrType> retainPtr(T) WARN_UNUSED_RETURN;
template<typename T> inline RetainPtr<T>::~RetainPtr()
{
if (StorageType ptr = std::exchange(m_ptr, nullptr))
CFRelease(ptr);
}
template<typename T> template<typename U> inline RetainPtr<T>::RetainPtr(const RetainPtr<U>& o)
: m_ptr(toStorageType(o.get()))
{
if (StorageType ptr = m_ptr)
CFRetain(ptr);
}
template<typename T> inline void RetainPtr<T>::clear()
{
if (StorageType ptr = std::exchange(m_ptr, nullptr))
CFRelease(ptr);
}
template<typename T> inline auto RetainPtr<T>::leakRef() -> PtrType
{
return fromStorageType(std::exchange(m_ptr, nullptr));
}
#ifndef __OBJC__
template<typename T> inline auto RetainPtr<T>::autorelease() -> PtrType
{
if (m_ptr)
CFAutorelease(m_ptr);
return leakRef();
}
#else
template<typename T> template<typename U> inline auto RetainPtr<T>::autoreleaseHelper() -> std::enable_if_t<std::is_convertible<U, id>::value, PtrType>
{
return CFBridgingRelease(std::exchange(m_ptr, nullptr));
}
template<typename T> template<typename U> inline auto RetainPtr<T>::autoreleaseHelper() -> std::enable_if_t<!std::is_convertible<U, id>::value, PtrType>
{
if (m_ptr)
CFAutorelease(m_ptr);
return leakRef();
}
template<typename T> inline auto RetainPtr<T>::autorelease() -> PtrType
{
return autoreleaseHelper<PtrType>();
}
// 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.
template<typename T> inline id RetainPtr<T>::bridgingAutorelease()
{
static_assert((!std::is_convertible<PtrType, id>::value), "Don't use bridgingAutorelease for Objective-C pointer types.");
return CFBridgingRelease(leakRef());
}
#endif
template<typename T> inline RetainPtr<T>& RetainPtr<T>::operator=(const RetainPtr& o)
{
RetainPtr ptr = o;
swap(ptr);
return *this;
}
template<typename T> template<typename U> inline RetainPtr<T>& RetainPtr<T>::operator=(const RetainPtr<U>& o)
{
RetainPtr ptr = o;
swap(ptr);
return *this;
}
template<typename T> inline RetainPtr<T>& RetainPtr<T>::operator=(PtrType optr)
{
RetainPtr ptr = optr;
swap(ptr);
return *this;
}
template<typename T> template<typename U> inline RetainPtr<T>& RetainPtr<T>::operator=(U* optr)
{
RetainPtr ptr = optr;
swap(ptr);
return *this;
}
template<typename T> inline RetainPtr<T>& RetainPtr<T>::operator=(RetainPtr&& o)
{
RetainPtr ptr = WTFMove(o);
swap(ptr);
return *this;
}
template<typename T> template<typename U> inline RetainPtr<T>& RetainPtr<T>::operator=(RetainPtr<U>&& o)
{
RetainPtr ptr = WTFMove(o);
swap(ptr);
return *this;
}
template<typename T> inline void RetainPtr<T>::swap(RetainPtr& o)
{
std::swap(m_ptr, o.m_ptr);
}
template<typename T> inline void swap(RetainPtr<T>& a, RetainPtr<T>& b)
{
a.swap(b);
}
template<typename T, typename U> inline bool operator==(const RetainPtr<T>& a, const RetainPtr<U>& b)
{
return a.get() == b.get();
}
template<typename T, typename U> inline bool operator==(const RetainPtr<T>& a, U* b)
{
return a.get() == b;
}
template<typename T, typename U> inline bool operator==(T* a, const RetainPtr<U>& b)
{
return a == b.get();
}
template<typename T, typename U> inline bool operator!=(const RetainPtr<T>& a, const RetainPtr<U>& b)
{
return a.get() != b.get();
}
template<typename T, typename U> inline bool operator!=(const RetainPtr<T>& a, U* b)
{
return a.get() != b;
}
template<typename T, typename U> inline bool operator!=(T* a, const RetainPtr<U>& b)
{
return a != b.get();
}
template<typename T> inline RetainPtr<T> adoptCF(T CF_RELEASES_ARGUMENT ptr)
{
#ifdef __OBJC__
static_assert((!std::is_convertible<T, id>::value), "Don't use adoptCF with Objective-C pointer types, use adoptNS.");
#endif
return RetainPtr<T>(ptr, RetainPtr<T>::Adopt);
}
#ifdef __OBJC__
template<typename T> inline RetainPtr<typename RetainPtr<T>::HelperPtrType> adoptNS(T NS_RELEASES_ARGUMENT ptr)
{
#if __has_feature(objc_arc)
return ptr;
#elif defined(OBJC_NO_GC)
return RetainPtr<typename RetainPtr<T>::HelperPtrType>(ptr, RetainPtr<typename RetainPtr<T>::HelperPtrType>::Adopt);
#else
RetainPtr<typename RetainPtr<T>::HelperPtrType> result = ptr;
[ptr release];
return result;
#endif
}
#endif
template<typename T> inline RetainPtr<typename RetainPtr<T>::HelperPtrType> retainPtr(T ptr)
{
return ptr;
}
template <typename T> struct IsSmartPtr<RetainPtr<T>> {
static constexpr bool value = true;
};
template<typename P> struct HashTraits<RetainPtr<P>> : SimpleClassHashTraits<RetainPtr<P>> {
};
template<typename P> struct DefaultHash<RetainPtr<P>> : PtrHash<RetainPtr<P>> { };
template <typename P>
struct RetainPtrObjectHashTraits : SimpleClassHashTraits<RetainPtr<P>> {
static const RetainPtr<P>& emptyValue()
{
static RetainPtr<P>& null = *(new RetainPtr<P>);
return null;
}
};
template <typename P>
struct RetainPtrObjectHash {
static unsigned hash(const RetainPtr<P>& o)
{
ASSERT_WITH_MESSAGE(o.get(), "attempt to use null RetainPtr in HashTable");
return static_cast<unsigned>(CFHash(o.get()));
}
static bool equal(const RetainPtr<P>& a, const RetainPtr<P>& b)
{
return CFEqual(a.get(), b.get());
}
static constexpr bool safeToCompareToEmptyOrDeleted = false;
};
inline bool safeCFEqual(CFTypeRef a, CFTypeRef b)
{
return (!a && !b) || (a && b && CFEqual(a, b));
}
inline CFHashCode safeCFHash(CFTypeRef a)
{
return a ? CFHash(a) : 0;
}
#ifdef __OBJC__
template<typename T> T* dynamic_objc_cast(id object)
{
if ([object isKindOfClass:[T class]])
return (T *)object;
return nil;
}
#endif
} // namespace WTF
using WTF::RetainPtr;
using WTF::adoptCF;
using WTF::retainPtr;
#ifdef __OBJC__
using WTF::adoptNS;
using WTF::dynamic_objc_cast;
#endif
#endif // USE(CF) || defined(__OBJC__)