/* Soot - a J*va Optimization Framework
* Copyright (C) 1999-2010 Hossein Sadat-Mohtasham
*
* 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.
*/
package soot.toolkits.graph.pdg;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import soot.toolkits.graph.DominatorNode;
import soot.toolkits.graph.DominatorTree;
import soot.toolkits.graph.DominatorsFinder;
/**
* Constructs a multi-headed dominator tree. This is mostly the same as the DominatorTree
* but the buildTree method is changed to allow mutilple heads. This can be used for
* graphs that are multi-headed and cannot be augmented to become single-headed.
*
* @author Hossein Sadat-Mohtasham
* March 2009
*
**/
@SuppressWarnings("unchecked")
public class MHGDominatorTree extends DominatorTree
{
protected ArrayList<DominatorNode> heads;
public MHGDominatorTree(DominatorsFinder dominators)
{
super(dominators);
}
/**
* Returns the root(s)!!! of the dominator tree.
**/
public List<DominatorNode> getHeads()
{
return (List<DominatorNode>) heads.clone();
}
/**
* This overrides the parent buildTree to allow multiple heads.
* Mostly copied from the super class and modified.
*
**/
protected void buildTree()
{
// hook up children with parents and vice-versa
this.heads = null;
for(Iterator godesIt = graph.iterator(); godesIt.hasNext();)
{
Object gode = godesIt.next();
DominatorNode dode = fetchDode(gode);
DominatorNode parent = fetchParent(gode);
if(parent == null){
//make sure the array is created!
if(heads == null)
heads = new ArrayList();
heads.add(dode);
}
else{
parent.addChild(dode);
dode.setParent(parent);
}
}
head = (DominatorNode) heads.get(0);
// identify the tail nodes
for(Iterator dodesIt = this.iterator(); dodesIt.hasNext();)
{
DominatorNode dode = (DominatorNode) dodesIt.next();
if(dode.isTail())
tails.add(dode);
}
}
}