tools/pldt/org.eclipse.ptp.pldt.mpi.analysis/src/org/eclipse/ptp/pldt/mpi/analysis/analysis/GotoEliminator.java

/**********************************************************************
 * Copyright (c) 2007 IBM Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.ptp.pldt.mpi.analysis.analysis;

import java.util.LinkedList;
import java.util.ListIterator;

import org.eclipse.cdt.core.dom.ast.ASTVisitor;
import org.eclipse.cdt.core.dom.ast.IASTBinaryExpression;
import org.eclipse.cdt.core.dom.ast.IASTBreakStatement;
import org.eclipse.cdt.core.dom.ast.IASTCaseStatement;
import org.eclipse.cdt.core.dom.ast.IASTCompoundStatement;
import org.eclipse.cdt.core.dom.ast.IASTDeclSpecifier;
import org.eclipse.cdt.core.dom.ast.IASTDeclarationStatement;
import org.eclipse.cdt.core.dom.ast.IASTDeclarator;
import org.eclipse.cdt.core.dom.ast.IASTDoStatement;
import org.eclipse.cdt.core.dom.ast.IASTExpression;
import org.eclipse.cdt.core.dom.ast.IASTExpressionStatement;
import org.eclipse.cdt.core.dom.ast.IASTForStatement;
import org.eclipse.cdt.core.dom.ast.IASTFunctionDefinition;
import org.eclipse.cdt.core.dom.ast.IASTGotoStatement;
import org.eclipse.cdt.core.dom.ast.IASTIdExpression;
import org.eclipse.cdt.core.dom.ast.IASTIfStatement;
import org.eclipse.cdt.core.dom.ast.IASTInitializerExpression;
import org.eclipse.cdt.core.dom.ast.IASTLabelStatement;
import org.eclipse.cdt.core.dom.ast.IASTLiteralExpression;
import org.eclipse.cdt.core.dom.ast.IASTName;
import org.eclipse.cdt.core.dom.ast.IASTNode;
import org.eclipse.cdt.core.dom.ast.IASTSimpleDeclSpecifier;
import org.eclipse.cdt.core.dom.ast.IASTSimpleDeclaration;
import org.eclipse.cdt.core.dom.ast.IASTStatement;
import org.eclipse.cdt.core.dom.ast.IASTSwitchStatement;
import org.eclipse.cdt.core.dom.ast.IASTUnaryExpression;
import org.eclipse.cdt.core.dom.ast.IASTWhileStatement;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTBinaryExpression;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTBreakStatement;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTCompoundStatement;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTDeclarationStatement;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTDoStatement;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTExpressionStatement;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTForStatement;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTIdExpression;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTIfStatement;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTInitializerExpression;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTLiteralExpression;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTName;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTSimpleDeclSpecifier;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTSimpleDeclaration;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTSwitchStatement;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTUnaryExpression;
import org.eclipse.cdt.internal.core.dom.parser.c.CASTWhileStatement;
import org.eclipse.ptp.pldt.mpi.analysis.cdt.graphs.ICallGraph;
import org.eclipse.ptp.pldt.mpi.analysis.cdt.graphs.ICallGraphNode;

public class GotoEliminator{

	private ICallGraph cg_;
	private LinkedList gotoList_;
	private LinkedList labelList_;
	
	private ICallGraphNode currentNode_;
	
	private int switch_count = 0;
	
	public GotoEliminator(ICallGraph cg){
		cg_ = cg;
		gotoList_ = null;
		labelList_ = null;
		currentNode_ = null;
	}
	
	public void run(){
		for(ICallGraphNode node = cg_.botEntry(); node != null; node = node.botNext()){
			currentNode_ = node;
			normalizeCompoundStmt(node.getFuncDef().getBody());
			GotoLabelCollector glc = new GotoLabelCollector(node);
			gotoList_ = glc.getGotoList();
			labelList_ = glc.getLabelList();
			if(gotoList_.size() == 0) continue;
			
			gotoPreprocessing();
			labelPreprocessing();
			while(gotoList_.size() > 0){
				IASTGotoStatement gotoS = (IASTGotoStatement)gotoList_.remove();
				IASTLabelStatement label = findLabel(gotoS);
				if(label == null){
					System.out.println("Empty goto label!"); //$NON-NLS-1$
					continue;
				}
				
				while(!isDirectedRelated(gotoS, label) && !isSibling(gotoS, label)){
					moveOutward(gotoS);
				}
				if(isDirectedRelated(gotoS, label)){
					if(Level(gotoS) > Level(label)){
						while(Level(gotoS) > Level(label))
							moveOutward(gotoS);
					}
					else{
						while(!Offset(gotoS, label))
							lifting(gotoS);
						while(Level(gotoS) < Level(label))
							moveInward(gotoS);
					}
				} 
				
				eliminatingGoto(gotoS);
			}
			
			while(labelList_.size() > 0){
				IASTLabelStatement label = (IASTLabelStatement)labelList_.remove();
				eliminatingStatement(label);
			}
		}
	}
	
	private void labelPreprocessing(){
		for(ListIterator li = labelList_.listIterator(); li.hasNext();){
			IASTLabelStatement label = (IASTLabelStatement)li.next();
			IASTName labelname = label.getName();
			String labelvar = "goto_" + labelname.toString(); //$NON-NLS-1$
			createDeclaration(labelvar);
			setLabelVariable(labelvar, label);
		}
	}
	
	private void gotoPreprocessing(){
		for(ListIterator li = gotoList_.listIterator(); li.hasNext();){
			IASTGotoStatement gotoS = (IASTGotoStatement)li.next();
			if(!(gotoS.getParent() instanceof IASTIfStatement)){
				IASTLiteralExpression condE = new CASTLiteralExpression();
				condE.setValue("true"); //$NON-NLS-1$
				
				IASTIfStatement ifS = new CASTIfStatement();
				ifS.setConditionExpression(condE);
				condE.setParent(ifS);
				ifS.setThenClause(gotoS);
				ifS.setElseClause(null);
				gotoS.setParent(ifS);
				
				replaceStatement(gotoS, ifS);
			}
		}
	}
	
	private void createDeclaration(String var){
		IASTSimpleDeclaration decl = new CASTSimpleDeclaration();
		
	    IASTSimpleDeclSpecifier declSpec = new CASTSimpleDeclSpecifier();
        declSpec.setConst(false);
        declSpec.setVolatile(false);
        declSpec.setInline(false);
        declSpec.setStorageClass(IASTDeclSpecifier.sc_unspecified);
        declSpec.setType(IASTSimpleDeclSpecifier.t_int);
        declSpec.setLong(false);
        declSpec.setUnsigned(false);
        declSpec.setSigned(true);
        declSpec.setShort(false);
	    
	    decl.setDeclSpecifier(declSpec);
	    declSpec.setParent(decl);
	    declSpec.setPropertyInParent(IASTSimpleDeclaration.DECL_SPECIFIER);
	    IASTDeclarator [] declarators = new IASTDeclarator[1];
	    IASTName name = new CASTName(var.toCharArray());
	    declarators[0].setName(name);
	    IASTLiteralExpression init = new CASTLiteralExpression();
	    init.setValue("0"); //$NON-NLS-1$
	    IASTInitializerExpression initE = new CASTInitializerExpression();
	    initE.setExpression(init);
	    declarators[0].setInitializer(initE);
	    
	    decl.addDeclarator(declarators[0]);
        declarators[0].setParent(decl);
        declarators[0].setPropertyInParent(IASTSimpleDeclaration.DECLARATOR);
        
        IASTDeclarationStatement declStmt = new CASTDeclarationStatement();
        declStmt.setDeclaration(decl);
        
        IASTCompoundStatement body = (IASTCompoundStatement)currentNode_.getFuncDef().getBody();
        IASTStatement[] stmts = body.getStatements();
        body.addStatement(stmts[stmts.length-1]);
        for(int i=stmts.length-1; i>0; i--){
        	stmts[i] = stmts[i-1];
        }
        stmts[0] = declStmt;
        stmts[0].setParent(stmts[1].getParent());
        stmts[0].setPropertyInParent(stmts[1].getPropertyInParent());
	}
	
	private void setLabelVariable(String var, IASTLabelStatement label){
		IASTName name = new CASTName(var.toCharArray());
		IASTIdExpression id = new CASTIdExpression();
		id.setName(name);
		name.setParent(id);

		IASTLiteralExpression value = new CASTLiteralExpression();
		value.setValue("0"); //$NON-NLS-1$

		IASTBinaryExpression biE = new CASTBinaryExpression();
		biE.setOperand1(id);
		biE.setOperand2(value);
		id.setParent(biE);
		value.setParent(biE);
		biE.setOperator(IASTBinaryExpression.op_assign);
		
		IASTExpressionStatement exprStmt = new CASTExpressionStatement();
		exprStmt.setExpression(biE);
		biE.setParent(exprStmt);
		
		IASTCompoundStatement compStmt = new CASTCompoundStatement();
		if(label.getNestedStatement() != null){
			IASTStatement nestedStmt = label.getNestedStatement();
			compStmt.setParent(nestedStmt.getParent());
			compStmt.setPropertyInParent(nestedStmt.getPropertyInParent());
			compStmt.addStatement(exprStmt);
			compStmt.addStatement(nestedStmt);
		}
		else {
			compStmt.addStatement(exprStmt);
			compStmt.setParent(label);
		}
		label.setNestedStatement(compStmt);
	}
	
	
	private IASTLabelStatement findLabel(IASTGotoStatement gotoS){
		IASTName labelname = gotoS.getName();
		for(ListIterator li = labelList_.listIterator(); li.hasNext();){
			IASTLabelStatement s = (IASTLabelStatement)li.next();
			if(s.getName().toString().equals(labelname.toString()))
				return s;
		}
		return null;
	}

	private boolean isSibling(IASTNode s1, IASTNode s2){
		IASTNode p1 = s1.getParent();
		IASTNode p2 = s2.getParent();
		if(p1 == p2 && p1 instanceof IASTCompoundStatement)
			return true;
		else
			return false;
	}
	
	
	private boolean isDirectedRelated(IASTGotoStatement gotoS, 
			IASTLabelStatement labelS){
		IASTNode parent;
		parent = gotoS.getParent();
		while(!(parent instanceof IASTFunctionDefinition)){
			if(isSibling(labelS, parent)) return true;
			else parent = parent.getParent();
		}
		parent = labelS.getParent();
		while(!(parent instanceof IASTFunctionDefinition)){
			if(isSibling(gotoS, parent)) return true;
			else parent = parent.getParent();
		}
		return false;
	}
	
	/* Delete redundantly nested compoundStatement 
	 * e.g. {{{s}}} --> {s}
	 * e.g. {{s1}{s2}} --> {s1 s2} 
	 */
	private void normalizeCompoundStmt(IASTStatement stmt){
		if(stmt instanceof IASTCompoundStatement){
			IASTCompoundStatement newCompS = new CASTCompoundStatement();
			IASTStatement stmts[] = ((IASTCompoundStatement)stmt).getStatements();
			for(int i = 0; i<stmts.length; i++){
				normalizeCompoundStmt(stmts[i]);
				if(stmts[i] instanceof IASTCompoundStatement){
					IASTCompoundStatement subCompS = (IASTCompoundStatement)stmts[i];
					IASTStatement subStmts[] = subCompS.getStatements();
					for(int j=0; j<subStmts.length; j++){
						newCompS.addStatement(subStmts[j]);
						subStmts[j].setParent(newCompS); // TODO: check here
					}
				} else {
					newCompS.addStatement(stmts[i]);
					stmts[i].setParent(newCompS); // TODO: check here
				}
			}
			replaceStatement(stmt, newCompS);
		} 
		else if(stmt instanceof IASTDoStatement){
			normalizeCompoundStmt(((IASTDoStatement)stmt).getBody());
		} 
		else if(stmt instanceof IASTForStatement){
			normalizeCompoundStmt(((IASTForStatement)stmt).getBody());
		} 
		else if(stmt instanceof IASTIfStatement){
			normalizeCompoundStmt(((IASTIfStatement)stmt).getThenClause());
			normalizeCompoundStmt(((IASTIfStatement)stmt).getElseClause());
		} 
		else if(stmt instanceof IASTSwitchStatement){
			normalizeCompoundStmt(((IASTSwitchStatement)stmt).getBody());
		} 
		else if(stmt instanceof IASTWhileStatement){
			normalizeCompoundStmt(((IASTWhileStatement)stmt).getBody());
		}
	}
	
	
	/* TODO: check the order of replace and parent setting */	
	private void moveOutward(IASTGotoStatement gotoS){
		String labelname = "goto_" + gotoS.getName().toString(); //$NON-NLS-1$
		IASTNode parent = gotoS.getParent().getParent();
		IASTNode body = gotoS.getParent();
		IASTIfStatement gotoIfStmt = (IASTIfStatement)body;
		
		while(!(parent instanceof IASTFunctionDefinition)){
			
			if(parent instanceof IASTDoStatement || 
					parent instanceof IASTForStatement ||
					parent instanceof IASTWhileStatement || 
					parent instanceof IASTSwitchStatement){
				IASTCompoundStatement newbody = new CASTCompoundStatement();
				if(body instanceof IASTCompoundStatement){
					IASTStatement[] stmts = ((IASTCompoundStatement)body).getStatements();
					int index;
					for(index=0; index<stmts.length; index++){
						if(stmts[index] == gotoIfStmt) break;
					}
					
					for(int j=0; j<index; j++){
						newbody.addStatement(stmts[j]);
					}
					IASTStatement assignS = makeGotoIfCondStoreStmt(gotoIfStmt.getConditionExpression(), labelname);
					newbody.addStatement(assignS);
					
					IASTName condname = new CASTName(labelname.toCharArray());
					IASTIdExpression condE = new CASTIdExpression();
					condE.setName(condname);
					condname.setParent(condE);
					
					IASTIfStatement ifS = new CASTIfStatement();
					ifS.setConditionExpression(condE);
					IASTBreakStatement breakS = new CASTBreakStatement();
					ifS.setThenClause(breakS);
					ifS.setElseClause(null);
					condE.setParent(ifS);
					breakS.setParent(ifS);
					
					newbody.addStatement(ifS);
					
					for(int j=index+1; j<stmts.length; j++){
						newbody.addStatement(stmts[j]);
					}
				}
				else if(body == gotoIfStmt){
					IASTStatement assignS = makeGotoIfCondStoreStmt(gotoIfStmt.getConditionExpression(), labelname);
					newbody.addStatement(assignS);
					
					IASTName condname = new CASTName(labelname.toCharArray());
					IASTIdExpression condE = new CASTIdExpression();
					condE.setName(condname);
					condname.setParent(condE);
					
					IASTIfStatement ifS = new CASTIfStatement();
					ifS.setConditionExpression(condE);
					IASTBreakStatement breakS = new CASTBreakStatement();
					ifS.setThenClause(breakS);
					ifS.setElseClause(null);
					condE.setParent(ifS);
					breakS.setParent(ifS);
					
					newbody.addStatement(ifS);
				}
				
				if(parent instanceof IASTDoStatement){
					((CASTDoStatement)parent).replace(body, newbody);
				} else if(parent instanceof IASTForStatement){
					((CASTForStatement)parent).replace(body, newbody);
				} else if(parent instanceof IASTWhileStatement){
					((CASTWhileStatement)parent).replace(body, newbody);
				} else if(parent instanceof IASTSwitchStatement){
					((CASTSwitchStatement)parent).replace(body, newbody);
				}

				IASTStatement newIfStmt = makeNewGotoIfStmt(labelname, gotoS);
				appendStatement(newIfStmt, (IASTStatement)parent);
				
				break;
			}
			else if(parent instanceof IASTIfStatement){
				if(body instanceof IASTCompoundStatement){
					IASTStatement[] stmts = ((IASTCompoundStatement)body).getStatements();
					int index;
					for(index=0; index<stmts.length; index++){
						if(stmts[index] == gotoIfStmt) break;
					}
					
					IASTCompoundStatement newbody = new CASTCompoundStatement();
					for(int j=0; j<index; j++){
						newbody.addStatement(stmts[j]);
					}
					IASTStatement assignS = makeGotoIfCondStoreStmt(gotoIfStmt.getConditionExpression(), labelname);
					newbody.addStatement(assignS);
					
					if(index < stmts.length-1){ //some statements after the goto
						IASTCompoundStatement ifbody = new CASTCompoundStatement();
						for(int j = index+1; j<stmts.length; j++){
							ifbody.addStatement(stmts[j]);
						}
						IASTName condname = new CASTName(labelname.toCharArray());
						IASTIdExpression condid = new CASTIdExpression();
						condid.setName(condname);
						condname.setParent(condid);
						
						IASTUnaryExpression condE = new CASTUnaryExpression();
						condE.setOperand(condid);
						condE.setOperator(IASTUnaryExpression.op_not);
						condid.setParent(condE);
						
						IASTIfStatement ifStmt = new CASTIfStatement();
						ifStmt.setConditionExpression(condE);
						ifStmt.setThenClause(ifbody);
						ifStmt.setElseClause(null);
						condE.setParent(ifStmt);
						ifbody.setParent(ifStmt);
						
						newbody.addStatement(ifStmt);
					}
					
					((CASTIfStatement)parent).replace(body, newbody);
				}
				else if(body == gotoIfStmt){
					IASTStatement assignS = makeGotoIfCondStoreStmt(gotoIfStmt.getConditionExpression(), labelname);
					((CASTIfStatement)parent).replace(gotoIfStmt, assignS);
				}
					
				IASTStatement newifStmt = makeNewGotoIfStmt(labelname, gotoS);
				appendStatement(newifStmt, (IASTStatement)parent); 
				 
				break;
			}
			else {
				body = parent;
				parent = body.getParent();
			}
		}
	}
	
	
	private void moveInward(IASTGotoStatement gotoS){
		IASTIfStatement gotoIfStmt = (IASTIfStatement)gotoS.getParent();
		String labelname = "goto_" + gotoS.getName().toString(); //$NON-NLS-1$
		IASTLabelStatement label = findLabel(gotoS);
		IASTStatement enclosingStmt = null;
		IASTStatement clause = null;
		IASTNode parent = label.getParent();
		IASTNode temp = label;
		while(!(parent instanceof IASTFunctionDefinition)){
			if(parent instanceof IASTDoStatement || 
					parent instanceof IASTForStatement ||
					parent instanceof IASTWhileStatement ||
					parent instanceof IASTSwitchStatement ||
					parent instanceof IASTIfStatement){
				enclosingStmt = (IASTStatement)parent;
				if(parent instanceof IASTIfStatement)
					clause = (IASTStatement)temp;
			}
			if(parent == gotoIfStmt.getParent()) break;
			else{
				temp = parent;
				parent = temp.getParent();
			}
		}
		
		if(enclosingStmt instanceof IASTDoStatement ||
				enclosingStmt instanceof IASTForStatement ||
				enclosingStmt instanceof IASTWhileStatement ){
			/* parent should be a CompoundStatement */
			int gotoindex = -1;
			int loopindex = -1;
			IASTStatement[] stmts = ((IASTCompoundStatement)parent).getStatements();
			for(int i = 0; i<stmts.length; i++){
				if(stmts[i] == gotoIfStmt) gotoindex = i;
				else if(stmts[i] == enclosingStmt) loopindex = i;
			}
			
			IASTCompoundStatement newParentStmt = new CASTCompoundStatement();
			
			for(int i=0; i<gotoindex; i++){
				newParentStmt.addStatement(stmts[i]);
				stmts[i].setParent(newParentStmt);
			}
			IASTStatement assignS = makeGotoIfCondStoreStmt(gotoIfStmt.getConditionExpression(), labelname);
			newParentStmt.addStatement(assignS);
			assignS.setParent(newParentStmt);
			
			if(loopindex - gotoindex > 1){
				IASTName condname = new CASTName(labelname.toCharArray());
				IASTIdExpression condid = new CASTIdExpression();
				condid.setName(condname);
				condname.setParent(condid);
				IASTUnaryExpression condE = new CASTUnaryExpression();
				condE.setOperand(condid);
				condE.setOperator(IASTUnaryExpression.op_not);
				condid.setParent(condE);
				
				IASTCompoundStatement ifbody = new CASTCompoundStatement();
				for(int i=gotoindex+1; i<loopindex; i++){
					ifbody.addStatement(stmts[i]);
					stmts[i].setParent(ifbody);
				}
				
				IASTIfStatement newIfStmt = new CASTIfStatement();
				newIfStmt.setConditionExpression(condE);
				newIfStmt.setThenClause(ifbody);
				newIfStmt.setElseClause(null);
				condE.setParent(newIfStmt);
				ifbody.setParent(newIfStmt);
				
				newParentStmt.addStatement(newIfStmt);
				newIfStmt.setParent(newParentStmt);
			}	
			
			IASTName loopcondname = new CASTName(labelname.toCharArray());
			IASTIdExpression loopcondid = new CASTIdExpression();
			loopcondid.setName(loopcondname);
			loopcondname.setParent(loopcondid);
			
			IASTStatement loopbody = null;
			if(enclosingStmt instanceof IASTDoStatement){
				IASTDoStatement doloop = (IASTDoStatement)enclosingStmt;
				IASTBinaryExpression newCondE = new CASTBinaryExpression();
				IASTExpression oldCondE = doloop.getCondition();
				newCondE.setOperand1(oldCondE);
				newCondE.setOperand2(loopcondid);
				newCondE.setOperator(IASTBinaryExpression.op_logicalOr);
				oldCondE.setParent(newCondE);
				loopcondid.setParent(newCondE);
				((CASTDoStatement)doloop).replace(oldCondE, newCondE);
				loopbody = doloop.getBody();
			} else if(enclosingStmt instanceof IASTForStatement){
				IASTForStatement forloop = (IASTForStatement)enclosingStmt;
				IASTBinaryExpression newCondE = new CASTBinaryExpression();
				IASTExpression oldCondE = forloop.getConditionExpression();
				newCondE.setOperand1(oldCondE);
				newCondE.setOperand2(loopcondid);
				newCondE.setOperator(IASTBinaryExpression.op_logicalOr);
				oldCondE.setParent(newCondE);
				loopcondid.setParent(newCondE);
				((CASTForStatement)forloop).replace(oldCondE, newCondE);
				loopbody = forloop.getBody();
			} else if(enclosingStmt instanceof IASTWhileStatement){
				IASTWhileStatement whileloop = (IASTWhileStatement)enclosingStmt;
				IASTBinaryExpression newCondE = new CASTBinaryExpression();
				IASTExpression oldCondE = whileloop.getCondition();
				newCondE.setOperand1(oldCondE);
				newCondE.setOperand2(loopcondid);
				newCondE.setOperator(IASTBinaryExpression.op_logicalOr);
				oldCondE.setParent(newCondE);
				loopcondid.setParent(newCondE);
				((CASTWhileStatement)whileloop).replace(oldCondE, newCondE);
				loopbody = whileloop.getBody();
			}
			
			IASTCompoundStatement newloopbody = new CASTCompoundStatement();
			IASTStatement newGotoS = makeNewGotoIfStmt(labelname, gotoS);
			newloopbody.addStatement(newGotoS);
			newGotoS.setParent(newloopbody);
			if(loopbody instanceof IASTCompoundStatement){
				IASTStatement[] bodyStmts = ((IASTCompoundStatement)loopbody).getStatements();
				for(int i = 0; i<bodyStmts.length; i++){
					newloopbody.addStatement(bodyStmts[i]);
					bodyStmts[i].setParent(newloopbody);
				}
			}
			else if(loopbody == label){
				newloopbody.addStatement(label);
				label.setParent(newloopbody);
			}
			
			if(enclosingStmt instanceof IASTDoStatement){
				((CASTDoStatement)enclosingStmt).replace(loopbody, newloopbody);
			} else if(enclosingStmt instanceof IASTForStatement){
				((CASTForStatement)enclosingStmt).replace(loopbody, newloopbody);
			} else if(enclosingStmt instanceof IASTWhileStatement){
				((CASTWhileStatement)enclosingStmt).replace(loopbody, newloopbody);
			}
			
			newParentStmt.addStatement(enclosingStmt);
			enclosingStmt.setParent(newParentStmt);
			
			for(int i = loopindex+1; i<stmts.length; i++){
				newParentStmt.addStatement(stmts[i]);
				stmts[i].setParent(newParentStmt);
			}
			replaceStatement((IASTStatement)parent, newParentStmt);

		}
		else if(enclosingStmt instanceof IASTIfStatement){
			/* parent must be a compoundStatement */
			IASTStatement[] stmts = ((IASTCompoundStatement)parent).getStatements();
			int gotoindex = -1;
			int ifindex = -1;
			for(int i=0; i<stmts.length; i++){
				if(stmts[i] == gotoIfStmt) gotoindex = i;
				else if(stmts[i] == enclosingStmt) ifindex = i;
			}
			
			IASTCompoundStatement newParentStmt = new CASTCompoundStatement();
			
			for(int i=0; i<gotoindex; i++){
				newParentStmt.addStatement(stmts[i]);
				stmts[i].setParent(newParentStmt);
			}
			IASTStatement assignS = makeGotoIfCondStoreStmt(gotoIfStmt.getConditionExpression(), labelname);
			newParentStmt.addStatement(assignS);
			assignS.setParent(newParentStmt);
			
			if(ifindex - gotoindex > 1){
				IASTName condname = new CASTName(labelname.toCharArray());
				IASTIdExpression condid = new CASTIdExpression();
				condid.setName(condname);
				condname.setParent(condid);
				IASTUnaryExpression condE = new CASTUnaryExpression();
				condE.setOperand(condid);
				condE.setOperator(IASTUnaryExpression.op_not);
				condid.setParent(condE);
				
				IASTCompoundStatement ifbody = new CASTCompoundStatement();
				for(int i=gotoindex+1; i<ifindex; i++){
					ifbody.addStatement(stmts[i]);
					stmts[i].setParent(ifbody);
				}
				
				IASTIfStatement newIfStmt = new CASTIfStatement();
				newIfStmt.setConditionExpression(condE);
				newIfStmt.setThenClause(ifbody);
				newIfStmt.setElseClause(null);
				condE.setParent(newIfStmt);
				ifbody.setParent(newIfStmt);
				
				newParentStmt.addStatement(newIfStmt);
				newIfStmt.setParent(newParentStmt);
			}
			
			IASTExpression oldIfCond = ((IASTIfStatement)enclosingStmt).getConditionExpression();
			IASTName ifcondname = new CASTName(labelname.toCharArray());
			IASTIdExpression ifcondid = new CASTIdExpression();
			ifcondid.setName(ifcondname);
			ifcondname.setParent(ifcondid);
			
			IASTUnaryExpression ifcondPart1 = new CASTUnaryExpression();
			ifcondPart1.setOperand(ifcondid);
			ifcondPart1.setOperator(IASTUnaryExpression.op_not);
			ifcondid.setParent(ifcondPart1);
			
			IASTBinaryExpression newIfCond = new CASTBinaryExpression();
			newIfCond.setOperator(IASTBinaryExpression.op_logicalAnd);
			newIfCond.setOperand1(ifcondPart1);
			newIfCond.setOperand2(oldIfCond);
			ifcondPart1.setParent(newIfCond);
			oldIfCond.setParent(newIfCond);
			
			((CASTIfStatement)enclosingStmt).replace(oldIfCond, newIfCond);
			
			IASTCompoundStatement newClause = new CASTCompoundStatement();
			IASTStatement newGotoS = makeNewGotoIfStmt(labelname, gotoS);
			newClause.addStatement(newGotoS);
			newGotoS.setParent(newClause);
			if(clause instanceof IASTCompoundStatement){
				IASTStatement[] clauseStmts = ((IASTCompoundStatement)clause).getStatements();
				for(int i = 0; i<clauseStmts.length; i++){
					newClause.addStatement(clauseStmts[i]);
					clauseStmts[i].setParent(newClause);
				}
			}
			else if(clause == label){
				newClause.addStatement(label);
				label.setParent(newClause);
			}
			
			((CASTIfStatement)enclosingStmt).replace(clause, newClause);
			
			newParentStmt.addStatement(enclosingStmt);
			enclosingStmt.setParent(newParentStmt);
			
			for(int i = ifindex+1; i<stmts.length; i++){
				newParentStmt.addStatement(stmts[i]);
				stmts[i].setParent(newParentStmt);
			}
			replaceStatement((IASTStatement)parent, newParentStmt);
		}
		else if(enclosingStmt instanceof IASTSwitchStatement){
			/* parent must be a compoundStatement */
			IASTStatement[] stmts = ((IASTCompoundStatement)parent).getStatements();
			int gotoindex = -1;
			int switchindex = -1;
			IASTCaseStatement caseStmt = null;
			boolean casefound = false;
			
			for(int i=0; i<stmts.length; i++){
				if(stmts[i] == gotoIfStmt) gotoindex = i;
				else if(stmts[i] == enclosingStmt){
					switchindex = i;
					casefound = true;
				}
				else if(stmts[i] instanceof IASTCaseStatement && !casefound){
					caseStmt = (IASTCaseStatement)stmts[i];
				}
			}
			
			IASTCompoundStatement newParentStmt = new CASTCompoundStatement();
			
			for(int i=0; i<gotoindex; i++){
				newParentStmt.addStatement(stmts[i]);
				stmts[i].setParent(newParentStmt);
			}
			IASTStatement assignS = makeGotoIfCondStoreStmt(gotoIfStmt.getConditionExpression(), labelname);
			newParentStmt.addStatement(assignS);
			assignS.setParent(newParentStmt);
			
			/* making new if statement */
			IASTName condname = new CASTName(labelname.toCharArray());
			IASTIdExpression condid = new CASTIdExpression();
			condid.setName(condname);
			condname.setParent(condid);
			IASTUnaryExpression condE = new CASTUnaryExpression();
			condE.setOperand(condid);
			condE.setOperator(IASTUnaryExpression.op_not);
			condid.setParent(condE);
			
			IASTCompoundStatement ifThenBody = new CASTCompoundStatement();
			for(int i=gotoindex+1; i<switchindex; i++){
				ifThenBody.addStatement(stmts[i]);
				stmts[i].setParent(ifThenBody);
			}
			
			String switchvar = "t_switch_" + switch_count; //$NON-NLS-1$
			switch_count ++;
			createDeclaration(switchvar); /* TODO: fix type information */
			IASTName switchCondAssignName = new CASTName(switchvar.toCharArray());
			IASTIdExpression switchCondAssignID = new CASTIdExpression();
			switchCondAssignID.setName(switchCondAssignName);
			switchCondAssignName.setParent(switchCondAssignID);
			IASTExpression oldSwitchCondE = ((IASTSwitchStatement)enclosingStmt).getControllerExpression();
			
			IASTBinaryExpression switchCondAssignE = new CASTBinaryExpression();
			switchCondAssignE.setOperand1(switchCondAssignID);
			switchCondAssignE.setOperand2(oldSwitchCondE);
			switchCondAssignE.setOperator(IASTBinaryExpression.op_assign);
			switchCondAssignID.setParent(switchCondAssignE);
			oldSwitchCondE.setParent(switchCondAssignE);
			
			IASTExpressionStatement switchCondAssignStmt = new CASTExpressionStatement();
			switchCondAssignStmt.setExpression(switchCondAssignE);
			switchCondAssignE.setParent(switchCondAssignStmt);
			
			ifThenBody.addStatement(switchCondAssignStmt);
			switchCondAssignStmt.setParent(ifThenBody);
			
			IASTName elseSwitchCondName = new CASTName(switchvar.toCharArray());
			IASTIdExpression elseSwitchCondID = new CASTIdExpression();
			elseSwitchCondID.setName(elseSwitchCondName);
			elseSwitchCondName.setParent(elseSwitchCondID);
			
			IASTBinaryExpression elseSwitchCondE = new CASTBinaryExpression();
			elseSwitchCondE.setOperator(IASTBinaryExpression.op_assign);
			elseSwitchCondE.setOperand1(elseSwitchCondID);
			elseSwitchCondE.setOperand2(caseStmt.getExpression());
			elseSwitchCondID.setParent(elseSwitchCondE);
			caseStmt.getExpression().setParent(elseSwitchCondE);
			
			IASTExpressionStatement elseSwitchCondStmt = new CASTExpressionStatement();
			elseSwitchCondStmt.setExpression(elseSwitchCondE);
			elseSwitchCondE.setParent(elseSwitchCondStmt);
			
			IASTIfStatement newIfStmt = new CASTIfStatement();
			newIfStmt.setConditionExpression(condE);
			newIfStmt.setThenClause(ifThenBody);
			newIfStmt.setElseClause(elseSwitchCondStmt);
			condE.setParent(newIfStmt);
			ifThenBody.setParent(newIfStmt);
			
			newParentStmt.addStatement(newIfStmt);
			newIfStmt.setParent(newParentStmt);
			/* end making new if statement */
			
			/* make new switch condition */
			IASTName switchCondName = new CASTName(switchvar.toCharArray());
			IASTIdExpression switchCondID = new CASTIdExpression();
			switchCondID.setName(switchCondName);
			switchCondName.setParent(switchCondID);
			
			((CASTSwitchStatement)enclosingStmt).replace(oldSwitchCondE, switchCondID);
			/* end make new switch condition */
			
			/* make new switch body */
			IASTCompoundStatement newSwitchBody = new CASTCompoundStatement();
			IASTStatement oldSwitchBody = ((IASTSwitchStatement)enclosingStmt).getBody();
			IASTStatement[] oldSwitchBodyStmts = ((IASTCompoundStatement)oldSwitchBody).getStatements();
			
			for(int i=0; i<oldSwitchBodyStmts.length; i++){
				if(oldSwitchBodyStmts[i] != caseStmt){
					newSwitchBody.addStatement(oldSwitchBodyStmts[i]);
					oldSwitchBodyStmts[i].setParent(newSwitchBody);
				} else {
					newSwitchBody.addStatement(caseStmt);
					caseStmt.setParent(newSwitchBody);
					IASTStatement newGotoS = makeNewGotoIfStmt(labelname, gotoS);
					newSwitchBody.addStatement(newGotoS);
					newGotoS.setParent(newSwitchBody);
				}
			}
			
			((CASTSwitchStatement)enclosingStmt).replace(oldSwitchBody, newSwitchBody);
			
			newParentStmt.addStatement(enclosingStmt);
			enclosingStmt.setParent(newParentStmt);
			
			for(int i = switchindex+1; i<stmts.length; i++){
				newParentStmt.addStatement(stmts[i]);
				stmts[i].setParent(newParentStmt);
			}
			replaceStatement((IASTStatement)parent, newParentStmt);
		}
	}
	
	private void lifting(IASTGotoStatement gotoS){
		IASTIfStatement gotoIfStmt = (IASTIfStatement)gotoS.getParent();
		String labelname = "goto_" + gotoS.getName().toString(); //$NON-NLS-1$
		IASTLabelStatement label = findLabel(gotoS);
		IASTStatement enclosingStmt = null;

		IASTNode parent = label.getParent();
		while(!(parent instanceof IASTFunctionDefinition)){
			if(parent instanceof IASTDoStatement || 
					parent instanceof IASTForStatement ||
					parent instanceof IASTWhileStatement ||
					parent instanceof IASTSwitchStatement ||
					parent instanceof IASTIfStatement){
				enclosingStmt = (IASTStatement)parent;
			}
			if(parent == gotoIfStmt.getParent()) break;
			else{
				parent = parent.getParent();
			}
		}
		
		/* parent should be a CompoundStatement */
		IASTStatement[] stmts = ((IASTCompoundStatement)parent).getStatements();
		int labelindex = -1;
		int gotoindex = -1;
		for(int i=0; i<stmts.length; i++){
			if(stmts[i] == enclosingStmt) labelindex = i;
			else if(stmts[i] == gotoIfStmt) gotoindex = i;
		}
		
		IASTCompoundStatement newParentStmt = new CASTCompoundStatement();
		for(int i=0; i<labelindex; i++){
			newParentStmt.addStatement(stmts[i]);
			stmts[i].setParent(newParentStmt);
		}
		
		/* make the do loop */
		IASTCompoundStatement loopbody = new CASTCompoundStatement();
		IASTStatement ifStmt = makeNewGotoIfStmt(labelname, gotoS);
		loopbody.addStatement(ifStmt);
		ifStmt.setParent(loopbody);
		
		for(int i=labelindex; i<gotoindex; i++){
			loopbody.addStatement(stmts[i]);
			stmts[i].setParent(loopbody);
		}
		
		IASTStatement gotoIfCondStmt = makeGotoIfCondStoreStmt(gotoIfStmt.getConditionExpression(), labelname);
		loopbody.addStatement(gotoIfCondStmt);
		gotoIfCondStmt.setParent(loopbody);
		
		IASTName condname = new CASTName(labelname.toCharArray());
		IASTIdExpression condID = new CASTIdExpression();
		condID.setName(condname);
		condname.setParent(condID);
		
		IASTDoStatement doStmt = new CASTDoStatement();
		doStmt.setBody(loopbody);
		doStmt.setCondition(condID);
		loopbody.setParent(doStmt);
		condID.setParent(doStmt);
		/* end make the do loop */
		
		newParentStmt.addStatement(doStmt);
		doStmt.setParent(newParentStmt);
		
		for(int i=gotoindex+1; i<stmts.length; i++){
			newParentStmt.addStatement(stmts[i]);
			stmts[i].setParent(newParentStmt);
		}
		
		replaceStatement((IASTStatement)parent, newParentStmt);
	}
	
	private void eliminatingGoto(IASTGotoStatement gotoS){
		/* gotoS and label should have the same parent, and the parent
		 * should be a compoundStatement
		 */
		IASTLabelStatement label = findLabel(gotoS);
		IASTIfStatement gotoIfStmt = (IASTIfStatement)gotoS.getParent();
		IASTCompoundStatement parent = (IASTCompoundStatement)gotoS.getParent();
		IASTStatement[] stmts = parent.getStatements();
		int gotoindex = -1;
		int labelindex = -1;
		for(int i=0; i<stmts.length; i++){
			if(stmts[i] == gotoIfStmt) gotoindex = i;
			else if(stmts[i] == label) labelindex = i;
		}
		
		IASTCompoundStatement newCompS = new CASTCompoundStatement();
		if(gotoindex < labelindex){
			for(int i=0; i<gotoindex; i++){
				newCompS.addStatement(stmts[i]);
				stmts[i].setParent(newCompS);
			}
			if(labelindex - gotoindex > 1){
				IASTCompoundStatement newIfBody = new CASTCompoundStatement();
				for(int i=gotoindex+1; i<labelindex; i++){
					newIfBody.addStatement(stmts[i]);
					stmts[i].setParent(newIfBody);
				}
				IASTUnaryExpression newCondE = new CASTUnaryExpression();
				newCondE.setOperator(IASTUnaryExpression.op_not);
				newCondE.setOperand(gotoIfStmt.getConditionExpression());
				gotoIfStmt.getConditionExpression().setParent(newCondE);
				
				IASTIfStatement newIfS = new CASTIfStatement();
				newIfS.setConditionExpression(newCondE);
				newIfS.setThenClause(newIfBody);
				newIfS.setElseClause(null);
				newIfBody.setParent(newIfS);
				newCondE.setParent(newIfS);
				
				newCompS.addStatement(newIfS);
				newIfS.setParent(newCompS);
			}
			
			for(int i=labelindex; i<stmts.length; i++){
				newCompS.addStatement(stmts[i]);
				stmts[i].setParent(newCompS);
			}
		}
		else { //gotoS occurs later than label
			for(int i=0; i<labelindex; i++){
				newCompS.addStatement(stmts[i]);
				stmts[i].setParent(newCompS);
			}

			IASTCompoundStatement loopbody = new CASTCompoundStatement();
			loopbody.addStatement(label);
			label.setParent(loopbody);
			for(int i=labelindex+1; i<gotoindex; i++){
				loopbody.addStatement(stmts[i]);
				stmts[i].setParent(loopbody);
			}
			
			IASTDoStatement newLoopS = new CASTDoStatement();
			newLoopS.setBody(loopbody);
			newLoopS.setCondition(gotoIfStmt.getConditionExpression());
			loopbody.setParent(newLoopS);
			gotoIfStmt.getConditionExpression().setParent(newLoopS);
			
			newCompS.addStatement(newLoopS);
			newLoopS.setParent(newCompS);
			
			for(int i=gotoindex+1; i<stmts.length; i++){
				newCompS.addStatement(stmts[i]);
				stmts[i].setParent(newCompS);
			}
		}
		replaceStatement(parent, newCompS);
	}
	
	private void eliminatingStatement(IASTStatement stmt){
		if(stmt instanceof IASTCompoundStatement){
			IASTStatement[] stmts = ((IASTCompoundStatement)stmt).getStatements();
			int validStmt = 0;
			for(int i=0; i<stmts.length; i++){
				if(stmts[i] != null) validStmt ++;
			}
			if(validStmt == 0){ // no valid statement
				replaceStatement(stmt, null);
				eliminatingStatement((IASTStatement)stmt.getParent());
			}
			else if(validStmt < stmts.length){ // some statements are not valid
				IASTCompoundStatement newCompS = new CASTCompoundStatement();
				for(int i=0; i<stmts.length; i++){
					if(stmts[i] != null){
						newCompS.addStatement(stmts[i]);
						stmts[i].setParent(newCompS);
					}
				}
				replaceStatement(stmt, newCompS);
			}
			
		} else if(stmt instanceof IASTDoStatement){
			IASTDoStatement doS = (IASTDoStatement)stmt;
			if(doS.getBody() == null && doS.getCondition() == null){
				replaceStatement(stmt, null);
				eliminatingStatement((IASTStatement)stmt.getParent());
			}
		} else if(stmt instanceof IASTForStatement){
			
		} else if(stmt instanceof IASTIfStatement){
			IASTIfStatement ifS = (IASTIfStatement)stmt;
			if(ifS.getThenClause() == null && ifS.getElseClause() == null){
				replaceStatement(stmt, null);
				eliminatingStatement((IASTStatement)stmt.getParent());
			} else if(ifS.getThenClause() == null && ifS.getElseClause() != null){
				IASTIfStatement newIfS = new CASTIfStatement();
				IASTUnaryExpression newCondE = new CASTUnaryExpression();
				newCondE.setOperator(IASTUnaryExpression.op_not);
				newCondE.setOperand(ifS.getConditionExpression());
				ifS.getConditionExpression().setParent(newCondE);
				
				newIfS.setConditionExpression(newCondE);
				newIfS.setThenClause(ifS.getElseClause());
				newIfS.setElseClause(null);
				ifS.getElseClause().setParent(newIfS);
				newCondE.setParent(newIfS);
				
				replaceStatement(ifS, newIfS);
			}

		} else if(stmt instanceof IASTLabelStatement){
			IASTLabelStatement labelS = (IASTLabelStatement)stmt;
			IASTStatement nestedS = labelS.getNestedStatement();
			if(nestedS == null){
				replaceStatement(stmt, null);
			} else {
				replaceStatement(stmt, nestedS);
			}
			eliminatingStatement((IASTStatement)stmt.getParent());
		} else if(stmt instanceof IASTSwitchStatement){
			
		} else if(stmt instanceof IASTWhileStatement){
			
		} else {
			
		}
	}
	
	/* return statement "labelname = cond;" */
	private IASTStatement makeGotoIfCondStoreStmt(IASTExpression cond, String labelname){
		IASTName assignName = new CASTName(labelname.toCharArray());
		IASTIdExpression assignID = new CASTIdExpression();
		assignID.setName(assignName);
		assignName.setParent(assignID);
		
		IASTBinaryExpression assignE = new CASTBinaryExpression();
		assignE.setOperand1(assignID);
		assignE.setOperand2(cond);
		assignE.setOperator(IASTBinaryExpression.op_assign);
		assignID.setParent(assignE);
		cond.setParent(assignE);
		
		IASTExpressionStatement assignS = new CASTExpressionStatement();
		assignS.setExpression(assignE);
		assignE.setParent(assignS);
		
		return assignS;
	}
	
	private IASTStatement makeNewGotoIfStmt(String labelname, 
						IASTGotoStatement gotoS){
		IASTName condname = new CASTName(labelname.toCharArray());
		IASTIdExpression condE = new CASTIdExpression();
		condE.setName(condname);
		condname.setParent(condE);
		
		IASTIfStatement newifStmt = new CASTIfStatement();
		newifStmt.setConditionExpression(condE);
		newifStmt.setThenClause(gotoS);
		newifStmt.setElseClause(null);
		condE.setParent(newifStmt);
		gotoS.setParent(newifStmt);
		
		return newifStmt;
	}
	
	private void replaceStatement(IASTStatement oldS, IASTStatement newS){
		IASTNode parent = oldS.getParent();
		if(parent instanceof IASTCompoundStatement){
			CASTCompoundStatement compS = (CASTCompoundStatement)parent;
			compS.replace(oldS, newS);
		}
		else if(parent instanceof IASTDoStatement){
			CASTDoStatement doS = (CASTDoStatement)parent;
			doS.replace(oldS, newS);
		}
		else if(parent instanceof IASTForStatement){
			CASTForStatement forS = (CASTForStatement)parent;
			forS.replace(oldS, newS);
		}
		else if(parent instanceof IASTIfStatement){
			CASTIfStatement ifS = (CASTIfStatement)parent;
			ifS.replace(oldS, newS);
		}
		else if(parent instanceof IASTSwitchStatement){
			CASTSwitchStatement switchS = (CASTSwitchStatement)parent;
			switchS.replace(oldS, newS);
		}
		else if(parent instanceof IASTWhileStatement){
			CASTWhileStatement whileS = (CASTWhileStatement)parent;
			whileS.replace(oldS, newS);
		}
	}
	
	/* append "stmt" right after the "prev" */
	private void appendStatement(IASTStatement stmt, IASTStatement prev){
		IASTCompoundStatement newcompS = new CASTCompoundStatement();
		newcompS.addStatement(prev);
		newcompS.addStatement(stmt);
		prev.setParent(newcompS);
		stmt.setParent(newcompS);
		replaceStatement(prev, newcompS);
	}
	
	
	private int Level(IASTStatement stmt){
		int count = 0;
		IASTNode parent = stmt.getParent();
		while(! (parent instanceof IASTFunctionDefinition)){
			if(parent instanceof IASTIfStatement || 
					parent instanceof IASTForStatement ||
					parent instanceof IASTDoStatement ||
					parent instanceof IASTWhileStatement ||
					parent instanceof IASTSwitchStatement)
				count ++;
			parent = parent.getParent();
		}
		return count;
	}
	
	/* return true if gotoS has lower offset than label, false otherwise */
	private boolean Offset(IASTGotoStatement gotoS, IASTLabelStatement label){
		OffsetCalculator oc = new OffsetCalculator(currentNode_, gotoS, label);
		return oc.gotoBFlabel();
	}
	
	
	class GotoLabelCollector extends ASTVisitor{
		private ICallGraphNode node_;
		private LinkedList<IASTStatement> gotoList_;
		private LinkedList<IASTStatement> labelList_;
		
		public GotoLabelCollector(ICallGraphNode node){
			node_ = node;
			gotoList_ = new LinkedList<IASTStatement>();
			labelList_ = new LinkedList<IASTStatement>();
		}
		
		public void run(){
			this.shouldVisitDeclarations = true;
			this.shouldVisitStatements = true;
			IASTStatement body = node_.getFuncDef().getBody();
			body.accept(this);
		}
		
		public int visit(IASTStatement stmt){
			if(stmt instanceof IASTGotoStatement)
				gotoList_.add(stmt);
			else if(stmt instanceof IASTLabelStatement)
				labelList_.add(stmt);
			return PROCESS_CONTINUE;
		}
		
		public LinkedList getGotoList(){return gotoList_;}
		public LinkedList getLabelList() {return labelList_;}
	}
	
	class OffsetCalculator extends ASTVisitor{
		private ICallGraphNode node_;
		private IASTGotoStatement gotoS_;
		private IASTLabelStatement labelS_;
		private int gotoMet;
		private int labelMet;
		private int count;
		
		public OffsetCalculator(ICallGraphNode node, IASTGotoStatement gotoS, IASTLabelStatement label){
			node_ = node;
			gotoS_ = gotoS;
			labelS_ = label;
			gotoMet = -1;
			labelMet = -1;
			count = 0;
		}
		
		public boolean gotoBFlabel(){
			this.shouldVisitStatements = true;
			IASTStatement body = node_.getFuncDef().getBody();
			body.accept(this);
			if(gotoMet == -1 || labelMet == -1){
				System.out.println("Goto or label not found!"); //$NON-NLS-1$
			} else if(gotoMet > 1 || labelMet > 1){
				System.out.println("Multiple gotos and labels are met!"); //$NON-NLS-1$
			}
			return gotoMet < labelMet;
		}
		
		public int visit(IASTStatement stmt){
			if(stmt instanceof IASTGotoStatement && stmt == gotoS_){
				gotoMet = count;
				count ++;
			} else if (stmt instanceof IASTLabelStatement && stmt == labelS_){
				labelMet = count;
				count ++;
			}
			return PROCESS_CONTINUE;
		}
	}
}