/* Ninetjer - _Truly_ Free (non-GPL) Unix .NET Runtime
 * Copyright (C) 2002-2005  Jay Freeman (saurik)
*/

/*
 *        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. The name of the author may not be used to endorse
 *    or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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 NINETJER_INSTRUCTION_HPP
#define NINETJER_INSTRUCTION_HPP

#include "cxx/platform.hpp"
#include "clr/linkage.hpp"

#ifdef MENES_PRAGMA_ONCE
#pragma once
#endif

#include "ext/cloneable.hpp"
#include "ext/adghook.hpp"
#include "ext/vector.hpp"

namespace clr {

class Instruction;
class TypeDefOrRef;

namespace be {
struct InstructionEdge_ {
    typedef Instruction ImplicitNode;
    typedef Instruction ExplicitNode;
}; }

struct ExecuteGraph :
    be::InstructionEdge_
{
};

struct StackGraph :
    be::InstructionEdge_
{
};

class Instruction :
    public ext::Cloneable,
    public ext::Edge<ExecuteGraph>,
    public ext::Edge<StackGraph>
{
  private:
    struct Slot_ {
        TypeDefOrRef *type_;
        Instruction *value_;
    };

    typedef ext::Vector<Slot_> StackList_;
    StackList_ stack_;

    unsigned depth_;

  protected:
    virtual unsigned GetStackUp() const = 0;
    virtual unsigned GetStackDown() const = 0;

    int GetStackDelta() const {
        return GetStackUp() - GetStackDown();
    }

  public:
    Instruction() :
        depth_(~unsigned())
    {
        ext::Edge<ExecuteGraph>::SetSize(1);
    }

    virtual ~Instruction() {
    }

    Instruction *GetNext() {
        return ext::Edge<ExecuteGraph>::GetImplicit()[0];
    }

    void SetNext(Instruction *next) {
        ext::Edge<ExecuteGraph>::SetEdge(0, next);
    }

    void UpdateStack(unsigned depth) {
        if (depth_ != ~unsigned())
            return;

        depth_ = depth;

        _assert(GetStackDown() <= depth_);
        depth += GetStackDelta();

        const ext::Edge<ExecuteGraph>::ImplicitNodeList &nodes(ext::Edge<ExecuteGraph>::GetImplicit());
        _foreach (const ext::Edge<ExecuteGraph>::ImplicitNodeList, node, nodes)
            if (*node != NULL)
                (*node)->UpdateStack(depth);
    }

    unsigned GetStackDepth() const {
        return depth_;
    }
};

typedef ext::Vector<Instruction *> InstructionList;

}

#endif//NINETJER_INSTRUCTION_HPP