mirror of
https://github.com/darlinghq/darling-objc4.git
synced 2024-11-26 21:50:26 +00:00
87 lines
2.6 KiB
C++
87 lines
2.6 KiB
C++
/*
|
|
* Copyright (c) 2019 Apple Inc. All Rights Reserved.
|
|
*
|
|
* @APPLE_LICENSE_HEADER_START@
|
|
*
|
|
* This file contains Original Code and/or Modifications of Original Code
|
|
* as defined in and that are subject to the Apple Public Source License
|
|
* Version 2.0 (the 'License'). You may not use this file except in
|
|
* compliance with the License. Please obtain a copy of the License at
|
|
* http://www.opensource.apple.com/apsl/ and read it before using this
|
|
* file.
|
|
*
|
|
* The Original Code and all software distributed under the License are
|
|
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
|
|
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
|
|
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
|
|
* Please see the License for the specific language governing rights and
|
|
* limitations under the License.
|
|
*
|
|
* @APPLE_LICENSE_HEADER_END@
|
|
*/
|
|
|
|
#ifndef DENSEMAPEXTRAS_H
|
|
#define DENSEMAPEXTRAS_H
|
|
|
|
#include "llvm-DenseMap.h"
|
|
#include "llvm-DenseSet.h"
|
|
|
|
namespace objc {
|
|
|
|
// We cannot use a C++ static initializer to initialize certain globals because
|
|
// libc calls us before our C++ initializers run. We also don't want a global
|
|
// pointer to some globals because of the extra indirection.
|
|
//
|
|
// ExplicitInit / LazyInit wrap doing it the hard way.
|
|
template <typename Type>
|
|
class ExplicitInit {
|
|
alignas(Type) uint8_t _storage[sizeof(Type)];
|
|
|
|
public:
|
|
template <typename... Ts>
|
|
void init(Ts &&... Args) {
|
|
new (_storage) Type(std::forward<Ts>(Args)...);
|
|
}
|
|
|
|
Type &get() {
|
|
return *reinterpret_cast<Type *>(_storage);
|
|
}
|
|
};
|
|
|
|
template <typename Type>
|
|
class LazyInit {
|
|
alignas(Type) uint8_t _storage[sizeof(Type)];
|
|
bool _didInit;
|
|
|
|
public:
|
|
template <typename... Ts>
|
|
Type *get(bool allowCreate, Ts &&... Args) {
|
|
if (!_didInit) {
|
|
if (!allowCreate) {
|
|
return nullptr;
|
|
}
|
|
new (_storage) Type(std::forward<Ts>(Args)...);
|
|
_didInit = true;
|
|
}
|
|
return reinterpret_cast<Type *>(_storage);
|
|
}
|
|
};
|
|
|
|
// Convenience class for Dense Maps & Sets
|
|
template <typename Key, typename Value>
|
|
class ExplicitInitDenseMap : public ExplicitInit<DenseMap<Key, Value>> { };
|
|
|
|
template <typename Key, typename Value>
|
|
class LazyInitDenseMap : public LazyInit<DenseMap<Key, Value>> { };
|
|
|
|
template <typename Value>
|
|
class ExplicitInitDenseSet : public ExplicitInit<DenseSet<Value>> { };
|
|
|
|
template <typename Value>
|
|
class LazyInitDenseSet : public LazyInit<DenseSet<Value>> { };
|
|
|
|
} // namespace objc
|
|
|
|
#endif /* DENSEMAPEXTRAS_H */
|