AndAggregator.java

/* Soot - a J*va Optimization Framework
 * Copyright (C) 2005 Nomair A. Naeem
 *
 * 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.dava.toolkits.base.AST.transformations;

import soot.*;
import soot.jimple.*;
import java.util.*;
import soot.dava.internal.SET.*;
import soot.dava.internal.AST.*;
import soot.dava.internal.javaRep.*;
import soot.dava.internal.asg.*;
import soot.dava.toolkits.base.AST.analysis.*;


/*
  Nomair A. Naeem 18-FEB-2005

  The class is responsible to do the following transformation on the AST
  
  if(A){                   if(A && B){
      if(B){                    Body1
         Body1   ----->    }
      }                    Body2
  }
  Body2

  The most important thing to check is that there is only one If Statement inside the
  outer if and that there is NO other statement.

  TO MAKE CODE EFFECIENT BLOCK THE ANALYSIS TO GOING INTO STATEMENTS
  this is done by overriding the caseASTStatementSequenceNode
*/

public class AndAggregator extends DepthFirstAdapter{

    public AndAggregator(){
    }
    public AndAggregator(boolean verbose){
	super(verbose);
    }

    public void caseASTStatementSequenceNode(ASTStatementSequenceNode node){
    }

    public void outASTIfNode(ASTIfNode node){
	List<Object> bodies = node.get_SubBodies();
	if(bodies.size()==1){ //this should always be one since there is only one body of an if statement
	    List body = (List)bodies.get(0);
	    //this is the if body check to see if this is a single if Node
	    if(body.size()==1){//size is good
		ASTNode bodyNode = (ASTNode)body.get(0);
		if(bodyNode instanceof ASTIfNode){
		    /*
		      We can do AndAggregation at this point
		      node contains the outer if
		      (ASTIfNode)bodyNode is the inner if
		    */

		    ASTCondition outerCond = node.get_Condition();
		    ASTCondition innerCond = ((ASTIfNode)bodyNode).get_Condition();

		    SETNodeLabel outerLabel = (node).get_Label();
		    SETNodeLabel innerLabel = ((ASTIfNode)bodyNode).get_Label();
		    
		    SETNodeLabel newLabel = null;
		    if(outerLabel.toString()==null && innerLabel.toString()==null){
			newLabel = outerLabel;
		    }
		    else if(outerLabel.toString()!=null && innerLabel.toString()==null){
			newLabel = outerLabel;
		    }
		    else if(outerLabel.toString()==null && innerLabel.toString()!=null){
			newLabel = innerLabel;
		    }
		    else if(outerLabel.toString()!=null && innerLabel.toString()!=null){
			newLabel=outerLabel;
			//however we have to change all occurance of inner label to point to that
			//of outerlabel now
			changeUses(outerLabel.toString(),innerLabel.toString(),bodyNode);
		    }

		    //aggregate the conditions
		    ASTCondition newCond = new ASTAndCondition(outerCond,innerCond);

		    //Get the body of the inner Node that will be the overall body
		    List<Object> newBodyList = ((ASTIfNode)bodyNode).get_SubBodies();

		    //retireve the actual body List
		    if(newBodyList.size()==1){//should always be one since this is body of IF
			List<Object> newBody = (List<Object>)newBodyList.get(0);
			node.replace(newLabel,newCond,newBody);
			//System.out.println("ANDDDDDD AGGREGATING !!!");
			G.v().ASTTransformations_modified=true;
		    }
		}
		else{//not an if node
		}
	    }
	    else{ //IfBody has more than 1 nodes cant do AND aggregation
	    }
	}
    }

    private void changeUses(String to, String from, ASTNode node){
	//remember this method is only called when "to" and "from" are both non null
	List<Object> subBodies = node.get_SubBodies();
	Iterator<Object> it = subBodies.iterator();
	while(it.hasNext()){
	    //going over all subBodies
	    if (node instanceof ASTStatementSequenceNode){
		//check for abrupt stmts

		ASTStatementSequenceNode stmtSeq = (ASTStatementSequenceNode)node;
		List<Object> statements = stmtSeq.getStatements();
		Iterator<Object> stmtIt = statements.iterator();
		while(stmtIt.hasNext()){
		    AugmentedStmt as = (AugmentedStmt)stmtIt.next();
		    Stmt s = as.get_Stmt();


		    if(s instanceof DAbruptStmt){
			DAbruptStmt abStmt = (DAbruptStmt)s;
			if(abStmt.is_Break() || abStmt.is_Continue()){
			    SETNodeLabel label = abStmt.getLabel();
			    String labelBroken = label.toString();
			    
			    if(labelBroken != null){//stmt breaks some label
				if(labelBroken.compareTo(from)==0){
				    //have to replace the "from" label to "to" label
				    label.set_Name(to);
				}
			    }
			}
		    }
		}
	    }
	    else{
		//need to recursively call changeUses
		List subBodyNodes=null;

		if(node instanceof ASTTryNode){
		    ASTTryNode.container subBody = (ASTTryNode.container)it.next();
		    subBodyNodes=(List)subBody.o;
		}
		else{
		    subBodyNodes = (List)it.next();
		}
		Iterator nodesIt = subBodyNodes.iterator();
		while(nodesIt.hasNext()){
		    changeUses(to,from,(ASTNode)nodesIt.next());
		}
	    }

	}//going through subBodies

    }

}