blob: c306bdbcce6b3c211e7bfa15e39eabd6922594e7 [file] [log] [blame]
/*
* Copyright (C) 2016-2019 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <Block.h>
#include <utility>
#include <wtf/Assertions.h>
#include <wtf/StdLibExtras.h>
#if __has_include(<ptrauth.h>)
#include <ptrauth.h>
#define WTF_COPY_FUNCTION_POINTER_QUALIFIER __ptrauth_block_copy_helper
#define WTF_DISPOSE_FUNCTION_POINTER_QUALIFIER __ptrauth_block_destroy_helper
#define WTF_INVOKE_FUNCTION_POINTER_QUALIFIER __ptrauth_block_invocation_pointer
#ifdef __ptrauth_objc_isa_pointer
#define WTF_ISA_POINTER_QUALIFIER __ptrauth_objc_isa_pointer
#else
#define WTF_ISA_POINTER_QUALIFIER
#endif
#else
#define WTF_COPY_FUNCTION_POINTER_QUALIFIER
#define WTF_DISPOSE_FUNCTION_POINTER_QUALIFIER
#define WTF_INVOKE_FUNCTION_POINTER_QUALIFIER
#define WTF_ISA_POINTER_QUALIFIER
#endif
// Because ARC enablement is a compile-time choice, and we compile this header
// both ways, we need a separate copy of our code when ARC is enabled.
#if __has_feature(objc_arc)
#define BlockPtr BlockPtrArc
#endif
namespace WTF {
extern "C" void* _NSConcreteMallocBlock[32];
template<typename> class BlockPtr;
template<typename R, typename... Args>
class BlockPtr<R (Args...)> {
public:
using BlockType = R (^)(Args...);
template<typename F>
static BlockPtr fromCallable(F function)
{
struct Descriptor {
uintptr_t reserved;
uintptr_t size;
void (*WTF_COPY_FUNCTION_POINTER_QUALIFIER copy)(void *dst, const void *src);
void (*WTF_DISPOSE_FUNCTION_POINTER_QUALIFIER dispose)(const void *);
};
struct Block {
void* WTF_ISA_POINTER_QUALIFIER isa;
int32_t flags;
int32_t reserved;
R (*WTF_INVOKE_FUNCTION_POINTER_QUALIFIER invoke)(void *, Args...);
const struct Descriptor* descriptor;
F f;
};
static const Descriptor descriptor {
0,
sizeof(Block),
// We keep the copy function null - the block is already on the heap
// so it should never be copied.
nullptr,
[](const void* ptr) {
static_cast<Block*>(const_cast<void*>(ptr))->f.~F();
}
};
Block* block = static_cast<Block*>(malloc(sizeof(Block)));
block->isa = _NSConcreteMallocBlock;
enum {
BLOCK_NEEDS_FREE = (1 << 24),
BLOCK_HAS_COPY_DISPOSE = (1 << 25),
};
const unsigned retainCount = 1;
block->flags = BLOCK_HAS_COPY_DISPOSE | BLOCK_NEEDS_FREE | (retainCount << 1);
block->reserved = 0;
block->invoke = [](void *ptr, Args... args) -> R {
return static_cast<Block*>(ptr)->f(std::forward<Args>(args)...);
};
block->descriptor = &descriptor;
new (&block->f) F { std::move(function) };
#if __has_feature(objc_arc)
return BlockPtr { (__bridge_transfer BlockType)block };
#else
BlockPtr blockPtr;
blockPtr.m_block = reinterpret_cast<BlockType>(block);
return blockPtr;
#endif
}
BlockPtr()
: m_block(nullptr)
{
}
BlockPtr(BlockType block)
#if __has_feature(objc_arc)
: m_block(WTFMove(block))
#else
: m_block(Block_copy(block))
#endif
{
}
BlockPtr(const BlockPtr& other)
#if __has_feature(objc_arc)
: m_block(other.m_block)
#else
: m_block(Block_copy(other.m_block))
#endif
{
}
BlockPtr(BlockPtr&& other)
: m_block(std::exchange(other.m_block, nullptr))
{
}
~BlockPtr()
{
#if !__has_feature(objc_arc)
Block_release(m_block);
#endif
}
BlockPtr& operator=(const BlockPtr& other)
{
#if __has_feature(objc_arc)
m_block = other.m_block;
#else
if (this != &other) {
Block_release(m_block);
m_block = Block_copy(other.m_block);
}
#endif
return *this;
}
BlockPtr& operator=(BlockPtr&& other)
{
ASSERT(this != &other);
#if !__has_feature(objc_arc)
Block_release(m_block);
#endif
m_block = std::exchange(other.m_block, nullptr);
return *this;
}
BlockType get() const { return m_block; }
explicit operator bool() const { return m_block; }
bool operator!() const { return !m_block; }
R operator()(Args... arguments) const
{
ASSERT(m_block);
return m_block(std::forward<Args>(arguments)...);
}
private:
BlockType m_block;
};
template<typename R, typename... Args>
inline BlockPtr<R (Args...)> makeBlockPtr(R (^block)(Args...))
{
return BlockPtr<R (Args...)>(block);
}
template<typename F, typename Class, typename R, typename... Args>
inline auto makeBlockPtr(F&& function, R (Class::*)(Args...) const)
{
return BlockPtr<R (Args...)>::fromCallable(std::forward<F>(function));
}
template<typename F, typename Class, typename R, typename... Args>
inline auto makeBlockPtr(F&& function, R (Class::*)(Args...))
{
return BlockPtr<R (Args...)>::fromCallable(std::forward<F>(function));
}
template<typename F>
inline auto makeBlockPtr(F&& function)
{
return makeBlockPtr(std::forward<F>(function), &F::operator());
}
}
using WTF::BlockPtr;
using WTF::makeBlockPtr;