/*

 * Copyright (C) 2007, 2008 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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 */

#ifndef JSVariableObject_h

#define JSVariableObject_h

#include "JSObject.h"

#include "Register.h"

#include "SymbolTable.h"

#include "UnusedParam.h"

#include <wtf/OwnArrayPtr.h>

#include <wtf/UnusedParam.h>

namespace JSC {

    class Register;

    class JSVariableObject : public JSObject {

        friend class JIT;

    public:

        SymbolTable& symbolTable() const { return *d->symbolTable; }

        virtual void putWithAttributes(ExecState*, const Identifier&, JSValue, unsigned attributes) = 0;

        virtual bool deleteProperty(ExecState*, const Identifier&);

        virtual void getOwnPropertyNames(ExecState*, PropertyNameArray&, EnumerationMode mode = ExcludeDontEnumProperties);

        virtual bool isVariableObject() const;

        virtual bool isDynamicScope(bool& requiresDynamicChecks) const = 0;

        Register& registerAt(int index) const { return d->registers[index]; }

        static PassRefPtr<Structure> createStructure(JSValue prototype)

        {

            return Structure::create(prototype, TypeInfo(ObjectType, StructureFlags), AnonymousSlotCount);

        }

    protected:

        static const unsigned StructureFlags = OverridesGetPropertyNames | JSObject::StructureFlags;

        // Subclasses of JSVariableObject can subclass this struct to add data

        // without increasing their own size (since there's a hard limit on the

        // size of a JSCell).

        struct JSVariableObjectData {

            JSVariableObjectData(SymbolTable* symbolTable, Register* registers)

                : symbolTable(symbolTable)

                , registers(registers)

            {

                ASSERT(symbolTable);

            }

            SymbolTable* symbolTable; // Maps name -> offset from "r" in register file.

            Register* registers; // "r" in the register file.

            OwnArrayPtr<Register> registerArray; // Independent copy of registers, used when a variable object copies its registers out of the register file.

        private:

            JSVariableObjectData(const JSVariableObjectData&);

            JSVariableObjectData& operator=(const JSVariableObjectData&);

        };

        JSVariableObject(NonNullPassRefPtr<Structure> structure, JSVariableObjectData* data)

            : JSObject(structure)

            , d(data) // Subclass owns this pointer.

        {

        }

        Register* copyRegisterArray(Register* src, size_t count);

        void setRegisters(Register* r, Register* registerArray);

        bool symbolTableGet(const Identifier&, PropertySlot&);

        bool symbolTableGet(const Identifier&, PropertyDescriptor&);

        bool symbolTableGet(const Identifier&, PropertySlot&, bool& slotIsWriteable);

        bool symbolTablePut(const Identifier&, JSValue);

        bool symbolTablePutWithAttributes(const Identifier&, JSValue, unsigned attributes);

        JSVariableObjectData* d;

    };

    inline bool JSVariableObject::symbolTableGet(const Identifier& propertyName, PropertySlot& slot)

    {

        SymbolTableEntry entry = symbolTable().inlineGet(propertyName.ustring().rep());

        if (!entry.isNull()) {

            slot.setRegisterSlot(&registerAt(entry.getIndex()));

            return true;

        }

        return false;

    }

    inline bool JSVariableObject::symbolTableGet(const Identifier& propertyName, PropertySlot& slot, bool& slotIsWriteable)

    {

        SymbolTableEntry entry = symbolTable().inlineGet(propertyName.ustring().rep());

        if (!entry.isNull()) {

            slot.setRegisterSlot(&registerAt(entry.getIndex()));

            slotIsWriteable = !entry.isReadOnly();

            return true;

        }

        return false;

    }

    inline bool JSVariableObject::symbolTablePut(const Identifier& propertyName, JSValue value)

    {

        ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));

        SymbolTableEntry entry = symbolTable().inlineGet(propertyName.ustring().rep());

        if (entry.isNull())

            return false;

        if (entry.isReadOnly())

            return true;

        registerAt(entry.getIndex()) = value;

        return true;

    }

    inline bool JSVariableObject::symbolTablePutWithAttributes(const Identifier& propertyName, JSValue value, unsigned attributes)

    {

        ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this));

        SymbolTable::iterator iter = symbolTable().find(propertyName.ustring().rep());

        if (iter == symbolTable().end())

            return false;

        SymbolTableEntry& entry = iter->second;

        ASSERT(!entry.isNull());

        entry.setAttributes(attributes);

        registerAt(entry.getIndex()) = value;

        return true;

    }

    inline Register* JSVariableObject::copyRegisterArray(Register* src, size_t count)

    {

        Register* registerArray = new Register[count];

        memcpy(registerArray, src, count * sizeof(Register));

        return registerArray;

    }

    inline void JSVariableObject::setRegisters(Register* registers, Register* registerArray)

    {

        ASSERT(registerArray != d->registerArray.get());

        d->registerArray.set(registerArray);

        d->registers = registers;

    }

} // namespace JSC

#endif // JSVariableObject_h