mirror of
https://github.com/darlinghq/darling-JavaScriptCore.git
synced 2025-04-11 19:31:00 +00:00
105 lines
4.0 KiB
C++
105 lines
4.0 KiB
C++
/*
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* Copyright (C) 2016 Apple Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
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* THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#pragma once
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#include "Heap.h"
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#include <wtf/StdLibExtras.h>
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namespace JSC {
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template<typename OwnerType, typename ElementType>
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void LazyProperty<OwnerType, ElementType>::Initializer::set(ElementType* value) const
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{
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property.set(vm, owner, value);
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}
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template<typename OwnerType, typename ElementType>
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template<typename Func>
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void LazyProperty<OwnerType, ElementType>::initLater(const Func&)
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{
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RELEASE_ASSERT(isStatelessLambda<Func>());
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// Logically we just want to stuff the function pointer into m_pointer, but then we'd be sad
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// because a function pointer is not guaranteed to be a multiple of anything. The tag bits
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// may be used for things. We address this problem by indirecting through a global const
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// variable. The "theFunc" variable is guaranteed to be native-aligned, i.e. at least a
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// multiple of 4.
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static const FuncType theFunc = callFunc<Func>;
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m_pointer = lazyTag | bitwise_cast<uintptr_t>(&theFunc);
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}
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template<typename OwnerType, typename ElementType>
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void LazyProperty<OwnerType, ElementType>::setMayBeNull(VM& vm, const OwnerType* owner, ElementType* value)
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{
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m_pointer = bitwise_cast<uintptr_t>(value);
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RELEASE_ASSERT(!(m_pointer & lazyTag));
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vm.heap.writeBarrier(owner, value);
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}
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template<typename OwnerType, typename ElementType>
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void LazyProperty<OwnerType, ElementType>::set(VM& vm, const OwnerType* owner, ElementType* value)
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{
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RELEASE_ASSERT(value);
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setMayBeNull(vm, owner, value);
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}
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template<typename OwnerType, typename ElementType>
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void LazyProperty<OwnerType, ElementType>::visit(SlotVisitor& visitor)
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{
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if (m_pointer && !(m_pointer & lazyTag))
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visitor.appendUnbarriered(bitwise_cast<ElementType*>(m_pointer));
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}
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template<typename OwnerType, typename ElementType>
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void LazyProperty<OwnerType, ElementType>::dump(PrintStream& out) const
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{
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if (!m_pointer) {
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out.print("<null>");
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return;
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}
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if (m_pointer & lazyTag) {
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out.print("Lazy:", RawPointer(bitwise_cast<void*>(m_pointer & ~lazyTag)));
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if (m_pointer & initializingTag)
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out.print("(Initializing)");
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return;
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}
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out.print(RawPointer(bitwise_cast<void*>(m_pointer)));
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}
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template<typename OwnerType, typename ElementType>
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template<typename Func>
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ElementType* LazyProperty<OwnerType, ElementType>::callFunc(const Initializer& initializer)
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{
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if (initializer.property.m_pointer & initializingTag)
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return nullptr;
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initializer.property.m_pointer |= initializingTag;
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callStatelessLambda<void, Func>(initializer);
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RELEASE_ASSERT(!(initializer.property.m_pointer & lazyTag));
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RELEASE_ASSERT(!(initializer.property.m_pointer & initializingTag));
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return bitwise_cast<ElementType*>(initializer.property.m_pointer);
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}
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} // namespace JSC
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