/*
 * Copyright (C) 2007, 2008, 2012 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 Computer, 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;
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef JSVariableObject_h
#define JSVariableObject_h

#include "JSObject.h"
#include "JSSymbolTableObject.h"
#include "Register.h"
#include "SymbolTable.h"
#include <wtf/UnusedParam.h>
#include <wtf/OwnArrayPtr.h>

namespace JSC {

    class LLIntOffsetsExtractor;
    class Register;

    class JSVariableObject : public JSSymbolTableObject {
        friend class JIT;
        friend class LLIntOffsetsExtractor;

    public:
        typedef JSSymbolTableObject Base;

        WriteBarrier<Unknown>& registerAt(int index) const { return m_registers[index]; }

        WriteBarrier<Unknown>* const * addressOfRegisters() const { return &m_registers; }
        static size_t offsetOfRegisters() { return OBJECT_OFFSETOF(JSVariableObject, m_registers); }

        JS_EXPORT_PRIVATE static void destroy(JSCell*);

    protected:
        static const unsigned StructureFlags = JSSymbolTableObject::StructureFlags;

        JSVariableObject(JSGlobalData& globalData, Structure* structure, SymbolTable* symbolTable, Register* registers)
            : JSSymbolTableObject(globalData, structure, symbolTable)
            , m_registers(reinterpret_cast<WriteBarrier<Unknown>*>(registers))
        {
        }

        void finishCreation(JSGlobalData& globalData)
        {
            Base::finishCreation(globalData);
            COMPILE_ASSERT(sizeof(WriteBarrier<Unknown>) == sizeof(Register), Register_should_be_same_size_as_WriteBarrier);
        }

        PassOwnArrayPtr<WriteBarrier<Unknown> > copyRegisterArray(JSGlobalData&, WriteBarrier<Unknown>* src, size_t count, size_t callframeStarts);
        void setRegisters(WriteBarrier<Unknown>* registers, PassOwnArrayPtr<WriteBarrier<Unknown> > registerArray);

        WriteBarrier<Unknown>* m_registers; // "r" in the register file.
        OwnArrayPtr<WriteBarrier<Unknown> > m_registerArray; // Independent copy of registers, used when a variable object copies its registers out of the register file.
    };

    inline PassOwnArrayPtr<WriteBarrier<Unknown> > JSVariableObject::copyRegisterArray(JSGlobalData& globalData, WriteBarrier<Unknown>* src, size_t count, size_t callframeStarts)
    {
        OwnArrayPtr<WriteBarrier<Unknown> > registerArray = adoptArrayPtr(new WriteBarrier<Unknown>[count]);
        for (size_t i = 0; i < callframeStarts; i++)
            registerArray[i].set(globalData, this, src[i].get());
        for (size_t i = callframeStarts + RegisterFile::CallFrameHeaderSize; i < count; i++)
            registerArray[i].set(globalData, this, src[i].get());

        return registerArray.release();
    }

    inline void JSVariableObject::setRegisters(WriteBarrier<Unknown>* registers, PassOwnArrayPtr<WriteBarrier<Unknown> > registerArray)
    {
        ASSERT(registerArray != m_registerArray);
        m_registerArray = registerArray;
        m_registers = registers;
    }

} // namespace JSC

#endif // JSVariableObject_h