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/*
* Copyright (C) 2007, 2008, 2012, 2015 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.
* 3. Neither the name of Apple Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE 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 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 "JSObject.h"
#include "JSSymbolTableObject.h"
#include "SymbolTable.h"
namespace JSC {
class LLIntOffsetsExtractor;
class JSEnvironmentRecord : public JSSymbolTableObject {
friend class JIT;
friend class LLIntOffsetsExtractor;
public:
typedef JSSymbolTableObject Base;
static const unsigned StructureFlags = Base::StructureFlags;
WriteBarrierBase<Unknown>* variables()
{
return bitwise_cast<WriteBarrierBase<Unknown>*>(bitwise_cast<char*>(this) + offsetOfVariables());
}
bool isValidScopeOffset(ScopeOffset offset)
{
return !!offset && offset.offset() < symbolTable()->scopeSize();
}
WriteBarrierBase<Unknown>& variableAt(ScopeOffset offset)
{
ASSERT(isValidScopeOffset(offset));
return variables()[offset.offset()];
}
static size_t offsetOfVariables()
{
return WTF::roundUpToMultipleOf<sizeof(WriteBarrier<Unknown>)>(sizeof(JSEnvironmentRecord));
}
static ptrdiff_t offsetOfVariable(ScopeOffset offset)
{
return offsetOfVariables() + offset.offset() * sizeof(WriteBarrier<Unknown>);
}
DECLARE_INFO;
static size_t allocationSizeForScopeSize(unsigned scopeSize)
{
return offsetOfVariables() + scopeSize * sizeof(WriteBarrier<Unknown>);
}
static size_t allocationSize(SymbolTable* symbolTable)
{
return allocationSizeForScopeSize(symbolTable->scopeSize());
}
protected:
JSEnvironmentRecord(
VM& vm,
Structure* structure,
JSScope* scope,
SymbolTable* symbolTable)
: Base(vm, structure, scope, symbolTable)
{
}
void finishCreationUninitialized(VM& vm)
{
Base::finishCreation(vm);
}
void finishCreation(VM& vm, JSValue value)
{
finishCreationUninitialized(vm);
ASSERT(value == jsUndefined() || value == jsTDZValue());
for (unsigned i = symbolTable()->scopeSize(); i--;) {
// Filling this with undefined/TDZEmptyValue is useful because that's what variables start out as.
variableAt(ScopeOffset(i)).setStartingValue(value);
}
}
static void visitChildren(JSCell*, SlotVisitor&);
static void heapSnapshot(JSCell*, HeapSnapshotBuilder&);
};
} // namespace JSC
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