/* Soot - a J*va Optimization Framework
 * Copyright (C) 2005 Antoine Mine
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * Implementation of the paper "A Combined Pointer and Purity Analysis for
 * Java Programs" by Alexandru Salcianu and Martin Rinard, within the
 * Soot Optimization Framework.
 *
 * by Antoine Mine, 2005/01/24
 */

package soot.jimple.toolkits.annotation.purity;
import soot.jimple.*;

import java.util.*;

/**
 * A node created dynamically and attached to a statement Stmt.
 * Can be either an inside or a load node.
 * Two such nodes are equal if and only if they have the same inside / load
 * flag and are attached to the same statement (we use Stmt.equal here).
 *
 */
public class PurityStmtNode implements PurityNode
{
    /** Statement that created the node */
    private Stmt id;

    /** true if an inside node, false if an load node */
    private boolean inside;

    /** gives a unique id, for pretty-printing purposes */
    private static final Map<Stmt, Integer> nMap = new HashMap<Stmt, Integer>();
    private static int n = 0;

    PurityStmtNode(Stmt id, boolean inside)
    { 
	this.id = id; this.inside = inside;
	if (!nMap.containsKey(id)) { nMap.put(id,new Integer(n)); n++; }
    }

    public String toString() 
    { 
	if (inside) return "I_"+nMap.get(id); else return "L_"+nMap.get(id);
	//if (inside) return "I_"+id; else return "L_"+id; 
    }

    public int hashCode() 
    { return id.hashCode(); }
    
    public boolean equals(Object o)
    {
	if (o instanceof PurityStmtNode) {
	    PurityStmtNode oo = (PurityStmtNode)o;
	    return id.equals(oo.id) && oo.inside==inside;
	}
	else return false;
    }

    public boolean isInside() 
    { return inside; }

    public boolean isLoad()
    { return !inside; }

    public boolean isParam() 
    { return false; }
}