/*

 * Copyright (C) 2008, 2009 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;

 * 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.

 */

#ifndef Register_h

#define Register_h

#include "JSValue.h"

#include <wtf/Assertions.h>

#include <wtf/FastAllocBase.h>

#include <wtf/VectorTraits.h>

namespace JSC {

    class CodeBlock;

    class ExecState;

    class JSActivation;

    class JSObject;

    class JSPropertyNameIterator;

    class ScopeChainNode;

    struct Instruction;

    typedef ExecState CallFrame;

    class Register : public WTF::FastAllocBase {

    public:

        Register();

        Register(const JSValue&);

        Register& operator=(const JSValue&);

        JSValue jsValue() const;

        Register& operator=(JSActivation*);

        Register& operator=(CallFrame*);

        Register& operator=(CodeBlock*);

        Register& operator=(JSPropertyNameIterator*);

        Register& operator=(ScopeChainNode*);

        Register& operator=(Instruction*);

        int32_t i() const;

        JSActivation* activation() const;

        CallFrame* callFrame() const;

        CodeBlock* codeBlock() const;

        JSObject* function() const;

        JSPropertyNameIterator* propertyNameIterator() const;

        ScopeChainNode* scopeChain() const;

        Instruction* vPC() const;

        static Register withInt(int32_t i)

        {

            Register r;

            r.u.i = i;

            return r;

        }

        static Register withCallee(JSObject* callee)

        {

            Register r;

            r.u.function = callee;

            return r;

        }

    private:

        union {

            int32_t i;

            EncodedJSValue value;

            JSActivation* activation;

            CallFrame* callFrame;

            CodeBlock* codeBlock;

            JSObject* function;

            JSPropertyNameIterator* propertyNameIterator;

            ScopeChainNode* scopeChain;

            Instruction* vPC;

        } u;

    };

    ALWAYS_INLINE Register::Register()

    {

#ifndef NDEBUG

        *this = JSValue();

#endif

    }

    ALWAYS_INLINE Register::Register(const JSValue& v)

    {

#if ENABLE(JSC_ZOMBIES)

        ASSERT(!v.isZombie());

#endif

        u.value = JSValue::encode(v);

    }

    ALWAYS_INLINE Register& Register::operator=(const JSValue& v)

    {

#if ENABLE(JSC_ZOMBIES)

        ASSERT(!v.isZombie());

#endif

        u.value = JSValue::encode(v);

        return *this;

    }

    ALWAYS_INLINE JSValue Register::jsValue() const

    {

        return JSValue::decode(u.value);

    }

    // Interpreter functions

    ALWAYS_INLINE Register& Register::operator=(JSActivation* activation)

    {

        u.activation = activation;

        return *this;

    }

    ALWAYS_INLINE Register& Register::operator=(CallFrame* callFrame)

    {

        u.callFrame = callFrame;

        return *this;

    }

    ALWAYS_INLINE Register& Register::operator=(CodeBlock* codeBlock)

    {

        u.codeBlock = codeBlock;

        return *this;

    }

    ALWAYS_INLINE Register& Register::operator=(Instruction* vPC)

    {

        u.vPC = vPC;

        return *this;

    }

    ALWAYS_INLINE Register& Register::operator=(ScopeChainNode* scopeChain)

    {

        u.scopeChain = scopeChain;

        return *this;

    }

    ALWAYS_INLINE Register& Register::operator=(JSPropertyNameIterator* propertyNameIterator)

    {

        u.propertyNameIterator = propertyNameIterator;

        return *this;

    }

    ALWAYS_INLINE int32_t Register::i() const

    {

        return u.i;

    }

    ALWAYS_INLINE JSActivation* Register::activation() const

    {

        return u.activation;

    }

    ALWAYS_INLINE CallFrame* Register::callFrame() const

    {

        return u.callFrame;

    }

    ALWAYS_INLINE CodeBlock* Register::codeBlock() const

    {

        return u.codeBlock;

    }

    ALWAYS_INLINE JSObject* Register::function() const

    {

        return u.function;

    }

    ALWAYS_INLINE JSPropertyNameIterator* Register::propertyNameIterator() const

    {

        return u.propertyNameIterator;

    }

    ALWAYS_INLINE ScopeChainNode* Register::scopeChain() const

    {

        return u.scopeChain;

    }

    ALWAYS_INLINE Instruction* Register::vPC() const

    {

        return u.vPC;

    }

} // namespace JSC

namespace WTF {

    template<> struct VectorTraits<JSC::Register> : VectorTraitsBase<true, JSC::Register> { };

} // namespace WTF

#endif // Register_h