/*

 * Copyright (C) 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;

 * 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 RegisterID_h

#define RegisterID_h

#include <wtf/Assertions.h>

#include <wtf/Noncopyable.h>

#include <wtf/VectorTraits.h>

namespace JSC {

    class RegisterID : public Noncopyable {

    public:

        RegisterID()

            : m_refCount(0)

            , m_isTemporary(false)

#ifndef NDEBUG

            , m_didSetIndex(false)

#endif

        {

        }

        explicit RegisterID(int index)

            : m_refCount(0)

            , m_index(index)

            , m_isTemporary(false)

#ifndef NDEBUG

            , m_didSetIndex(true)

#endif

        {

        }

        void setIndex(int index)

        {

            ASSERT(!m_refCount);

#ifndef NDEBUG

            m_didSetIndex = true;

#endif

            m_index = index;

        }

        void setTemporary()

        {

            m_isTemporary = true;

        }

        int index() const

        {

            ASSERT(m_didSetIndex);

            return m_index;

        }

        bool isTemporary()

        {

            return m_isTemporary;

        }

        void ref()

        {

            ++m_refCount;

        }

        void deref()

        {

            --m_refCount;

            ASSERT(m_refCount >= 0);

        }

        int refCount() const

        {

            return m_refCount;

        }

    private:

        int m_refCount;

        int m_index;

        bool m_isTemporary;

#ifndef NDEBUG

        bool m_didSetIndex;

#endif

    };

} // namespace JSC

namespace WTF {

    template<> struct VectorTraits<JSC::RegisterID> : VectorTraitsBase<true, JSC::RegisterID> {

        static const bool needsInitialization = true;

        static const bool canInitializeWithMemset = true; // Default initialization just sets everything to 0 or false, so this is safe.

    };

} // namespace WTF

#endif // RegisterID_h