/*

 *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)

 *  Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.

 *  Copyright (C) 2007 Cameron Zwarich (cwzwarich@uwaterloo.ca)

 *  Copyright (C) 2007 Maks Orlovich

 *

 *  This library is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU Library General Public

 *  License as published by the Free Software Foundation; either

 *  version 2 of the License, or (at your option) any later version.

 *

 *  This library is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 *  Library General Public License for more details.

 *

 *  You should have received a copy of the GNU Library General Public License

 *  along with this library; see the file COPYING.LIB.  If not, write to

 *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

 *  Boston, MA 02110-1301, USA.

 *

 */

#ifndef Arguments_h

#define Arguments_h

#include "JSActivation.h"

#include "JSFunction.h"

#include "JSGlobalObject.h"

#include "Interpreter.h"

#include "ObjectConstructor.h"

#include "PrototypeFunction.h"

namespace JSC {

    struct ArgumentsData : Noncopyable {

        JSActivation* activation;

        unsigned numParameters;

        ptrdiff_t firstParameterIndex;

        unsigned numArguments;

        Register* registers;

        OwnArrayPtr<Register> registerArray;

        Register* extraArguments;

        OwnArrayPtr<bool> deletedArguments;

        Register extraArgumentsFixedBuffer[4];

        JSFunction* callee;

        bool overrodeLength : 1;

        bool overrodeCallee : 1;

    };

    class Arguments : public JSObject {

    public:

        enum NoParametersType { NoParameters };

        Arguments(CallFrame*);

        Arguments(CallFrame*, NoParametersType);

        virtual ~Arguments();

        static const ClassInfo info;

        virtual void markChildren(MarkStack&);

        void fillArgList(ExecState*, MarkedArgumentBuffer&);

        uint32_t numProvidedArguments(ExecState* exec) const 

        {

            if (UNLIKELY(d->overrodeLength))

                return get(exec, exec->propertyNames().length).toUInt32(exec);

            return d->numArguments; 

        }

        void copyToRegisters(ExecState* exec, Register* buffer, uint32_t maxSize);

        void copyRegisters();

        bool isTornOff() const { return d->registerArray; }

        void setActivation(JSActivation* activation)

        {

            d->activation = activation;

            d->registers = &activation->registerAt(0);

        }

        static PassRefPtr<Structure> createStructure(JSValue prototype) 

        { 

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

        }

    protected:

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

    private:

        void getArgumentsData(CallFrame*, JSFunction*&, ptrdiff_t& firstParameterIndex, Register*& argv, int& argc);

        virtual bool getOwnPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);

        virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);

        virtual bool getOwnPropertyDescriptor(ExecState*, const Identifier&, PropertyDescriptor&);

        virtual void put(ExecState*, const Identifier& propertyName, JSValue, PutPropertySlot&);

        virtual void put(ExecState*, unsigned propertyName, JSValue, PutPropertySlot&);

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

        virtual bool deleteProperty(ExecState*, unsigned propertyName);

        virtual const ClassInfo* classInfo() const { return &info; }

        void init(CallFrame*);

        OwnPtr<ArgumentsData> d;

    };

    Arguments* asArguments(JSValue);

    inline Arguments* asArguments(JSValue value)

    {

        ASSERT(asObject(value)->inherits(&Arguments::info));

        return static_cast<Arguments*>(asObject(value));

    }

    ALWAYS_INLINE void Arguments::getArgumentsData(CallFrame* callFrame, JSFunction*& function, ptrdiff_t& firstParameterIndex, Register*& argv, int& argc)

    {

        function = callFrame->callee();

        int numParameters = function->jsExecutable()->parameterCount();

        argc = callFrame->argumentCount();

        if (argc <= numParameters)

            argv = callFrame->registers() - RegisterFile::CallFrameHeaderSize - numParameters;

        else

            argv = callFrame->registers() - RegisterFile::CallFrameHeaderSize - numParameters - argc;

        argc -= 1; // - 1 to skip "this"

        firstParameterIndex = -RegisterFile::CallFrameHeaderSize - numParameters;

    }

    inline Arguments::Arguments(CallFrame* callFrame)

        : JSObject(callFrame->lexicalGlobalObject()->argumentsStructure())

        , d(new ArgumentsData)

    {

        JSFunction* callee;

        ptrdiff_t firstParameterIndex;

        Register* argv;

        int numArguments;

        getArgumentsData(callFrame, callee, firstParameterIndex, argv, numArguments);

        d->numParameters = callee->jsExecutable()->parameterCount();

        d->firstParameterIndex = firstParameterIndex;

        d->numArguments = numArguments;

        d->activation = 0;

        d->registers = callFrame->registers();

        Register* extraArguments;

        if (d->numArguments <= d->numParameters)

            extraArguments = 0;

        else {

            unsigned numExtraArguments = d->numArguments - d->numParameters;

            if (numExtraArguments > sizeof(d->extraArgumentsFixedBuffer) / sizeof(Register))

                extraArguments = new Register[numExtraArguments];

            else

                extraArguments = d->extraArgumentsFixedBuffer;

            for (unsigned i = 0; i < numExtraArguments; ++i)

                extraArguments[i] = argv[d->numParameters + i];

        }

        d->extraArguments = extraArguments;

        d->callee = callee;

        d->overrodeLength = false;

        d->overrodeCallee = false;

    }

    inline Arguments::Arguments(CallFrame* callFrame, NoParametersType)

        : JSObject(callFrame->lexicalGlobalObject()->argumentsStructure())

        , d(new ArgumentsData)

    {

        ASSERT(!callFrame->callee()->jsExecutable()->parameterCount());

        unsigned numArguments = callFrame->argumentCount() - 1;

        d->numParameters = 0;

        d->numArguments = numArguments;

        d->activation = 0;

        Register* extraArguments;

        if (numArguments > sizeof(d->extraArgumentsFixedBuffer) / sizeof(Register))

            extraArguments = new Register[numArguments];

        else

            extraArguments = d->extraArgumentsFixedBuffer;

        Register* argv = callFrame->registers() - RegisterFile::CallFrameHeaderSize - numArguments - 1;

        for (unsigned i = 0; i < numArguments; ++i)

            extraArguments[i] = argv[i];

        d->extraArguments = extraArguments;

        d->callee = callFrame->callee();

        d->overrodeLength = false;

        d->overrodeCallee = false;

    }

    inline void Arguments::copyRegisters()

    {

        ASSERT(!isTornOff());

        if (!d->numParameters)

            return;

        int registerOffset = d->numParameters + RegisterFile::CallFrameHeaderSize;

        size_t registerArraySize = d->numParameters;

        Register* registerArray = new Register[registerArraySize];

        memcpy(registerArray, d->registers - registerOffset, registerArraySize * sizeof(Register));

        d->registerArray.set(registerArray);

        d->registers = registerArray + registerOffset;

    }

    // This JSActivation function is defined here so it can get at Arguments::setRegisters.

    inline void JSActivation::copyRegisters(Arguments* arguments)

    {

        ASSERT(!d()->registerArray);

        size_t numParametersMinusThis = d()->functionExecutable->generatedBytecode().m_numParameters - 1;

        size_t numVars = d()->functionExecutable->generatedBytecode().m_numVars;

        size_t numLocals = numVars + numParametersMinusThis;

        if (!numLocals)

            return;

        int registerOffset = numParametersMinusThis + RegisterFile::CallFrameHeaderSize;

        size_t registerArraySize = numLocals + RegisterFile::CallFrameHeaderSize;

        Register* registerArray = copyRegisterArray(d()->registers - registerOffset, registerArraySize);

        setRegisters(registerArray + registerOffset, registerArray);

        if (arguments && !arguments->isTornOff())

            static_cast<Arguments*>(arguments)->setActivation(this);

    }

    ALWAYS_INLINE Arguments* Register::arguments() const

    {

        if (jsValue() == JSValue())

            return 0;

        return asArguments(jsValue());

    }

} // namespace JSC

#endif // Arguments_h