/*

 * Copyright (C) 2012 David Anderson

 *

 * This file is part of JITCraft.

 *

 * JITCraft is free software: you can redistribute it and/or modify it under

 * the terms of the GNU General Public License as published by the Free

 * Software Foundation, either version 3 of the License, or (at your option)

 * any later version.

 * 

 * Foobar 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 General Public License for more details.

 *

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

 * JITCraft. If not, see http://www.gnu.org/licenses/.

 */

#ifndef _include_jitcraft_reference_h_

#define _include_jitcraft_reference_h_

#include "Heap.h"

#include "Barriers.h"

#include "Stack.h"

namespace ke {

class Array;

class Struct;

// A Reference is a typed pointer to another location in memory.

class Reference : public Object

{

    void *location_;

    Barriered<Object> base_;

    // We do not compute references to objects, so this does not need to be

    // traced.

    LocalSlot slot_;

  public:

    static Reference *NewStack(Zone *zone, void *location, Heap::Tenure tenure = Heap::Tenure_Default);

    static Reference *NewStack(Zone *zone, const LocalSlot &slot, Heap::Tenure tenure = Heap::Tenure_Default);

    static Reference *NewArray(Zone *zone, Handle<Array> base, size_t index, Heap::Tenure tenure = Heap::Tenure_Default);

    static Reference *NewField(Zone *zone, Handle<Struct> obj, size_t index, Heap::Tenure tenure = Heap::Tenure_Default);

    int getInt() {

        return *reinterpret_cast<int *>(location_);

    }

    void setInt(int i) {

        *reinterpret_cast<int *>(location_) = i;

    }

    float getFloat() {

        return *reinterpret_cast<float *>(location_);

    }

    void setFloat(float f) {

        *reinterpret_cast<float *>(location_) = f;

    }

    // WARNING! This should only be for Native calls.

    void *location() {

        return location_;

    }

    // Begin GC Descriptor.

    static inline size_t offsetOfBase() {

        return offsetof(Reference, base_);

    }

    // End GC Descriptor.

    static inline Reference *cast(Object *obj) {

        assert(!obj || obj->is(MapKind_Reference));

        return reinterpret_cast<Reference *>(obj);

    }

};

}

#endif // _include_jitcraft_reference_h_