/* Theoretic - Graph Theoretic Byte Code Engineering
 * Copyright (C) 2001-2002  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.
*/

#include "stdafx.h"

#include "theoretic/OpGraph.h"
#include "engines/msil.h"

namespace Theoretic {

OpGraph::OpGraph(Operation *root) :
    root(root)
{
    Add(root);
}

OpGraph::~OpGraph() {
    for (OperSet::iterator op = ops.begin(); op != ops.end(); ++op)
        delete *op;
}

void OpGraph::Collect() {
    OperSet old = ops;
    ops.clear();
    Add(root);

    OperSet remove;
    std::set_difference(old.begin(), old.end(), ops.begin(), ops.end(), std::inserter(remove, remove.begin()));

    for (OperSet::iterator op = remove.begin(); op != remove.end(); ++op)
        delete *op;
}

Operation *OpGraph::GetRoot() {
    return root;
}

void OpGraph::Add(Operation *op) {
    if (op != NULL && ops.insert(op).second) {
        const Operation::LinkMap &links = op->GetLinks();
        for (Operation::LinkMap::const_iterator link = links.begin(); link != links.end(); ++link)
            Add(link->second);
    }
}

void OpGraph::Add(const OpList &list) {
    const OpList::OperList &ops = list.GetOps();
    for (OpList::OperList::const_iterator op = ops.begin(); op != ops.end(); ++op)
        Add(*op);
}

void OpGraph::Graft(Operation *from, Operation *to) {
    if (root == from)
        root = to;
    for (OperSet::iterator op = ops.begin(); op != ops.end(); ++op) {
        Operation::LinkMap &links = (*op)->GetLinks();
        for (Operation::LinkMap::iterator link = links.begin(); link != links.end(); ++link) {
            OpList::OperList &list = link->second.GetOps();
            for (OpList::OperList::iterator target = list.begin(); target != list.end(); ++target)
                if (*target == from)
                    *target = to;
        }
    }
}

void OpGraph::Cement(const Metallurgy::Method &method) {
    for (OperSet::iterator op = ops.begin(); op != ops.end(); ++op)
        (*op)->Cement(method);
}

void OpGraph::Optimize() {
    start: Collect();
    {for (OperSet::const_iterator iop = ops.begin(); iop != ops.end(); ++iop) {
        Operation *op = *iop;

        if (op->Resolvable() && !op->ResolveStack(this, NULL))
            goto start;
    }}//

    Collect();

    {for (OperSet::const_iterator iop = ops.begin(); iop != ops.end(); ++iop) {
        Operation *op = *iop;
        if (op->GetName() != L"msil:brtrue")
            continue;
        
    }}//
}

OpGraph::LinkList OpGraph::BackLinks(Operation *from) const {
    LinkList back;

    for (OperSet::const_iterator op = ops.begin(); op != ops.end(); ++op) {
        const Operation::LinkMap &links = (*op)->GetLinks();
        for (Operation::LinkMap::const_iterator link = links.begin(); link != links.end(); ++link) {
            const OpList::OperList &list = link->second.GetOps();
            for (int target(0); target < list.size(); ++target)
                if (list[target] == from)
                    back.push_back(Link(*op, LinkRef(link->first, target)));
        }
    }

    return back;
}

const OperSet &OpGraph::GetOps() const {
    return ops;
}

}