JumpElimination.java Source File

00001 package edu.ksu.cis.bandera.jjjc.optimizer;
00002 
00003 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
00004  * Bandera, a Java(TM) analysis and transformation toolkit           *
00005  * Copyright (C) 1999, 2000   Robby (robby@cis.ksu.edu)              *
00006  * All rights reserved.                                              *
00007  *                                                                   *
00008  * This work was done as a project in the SAnToS Laboratory,         *
00009  * Department of Computing and Information Sciences, Kansas State    *
00010  * University, USA (http://www.cis.ksu.edu/santos).                  *
00011  * It is understood that any modification not identified as such is  *
00012  * not covered by the preceding statement.                           *
00013  *                                                                   *
00014  * This work is free software; you can redistribute it and/or        *
00015  * modify it under the terms of the GNU Library General Public       *
00016  * License as published by the Free Software Foundation; either      *
00017  * version 2 of the License, or (at your option) any later version.  *
00018  *                                                                   *
00019  * This work is distributed in the hope that it will be useful,      *
00020  * but WITHOUT ANY WARRANTY; without even the implied warranty of    *
00021  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU *
00022  * Library General Public License for more details.                  *
00023  *                                                                   *
00024  * You should have received a copy of the GNU Library General Public *
00025  * License along with this toolkit; if not, write to the             *
00026  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,      *
00027  * Boston, MA  02111-1307, USA.                                      *
00028  *                                                                   *
00029  * Java is a trademark of Sun Microsystems, Inc.                     *
00030  *                                                                   *
00031  * To submit a bug report, send a comment, or get the latest news on *
00032  * this project and other SAnToS projects, please visit the web-site *
00033  *                http://www.cis.ksu.edu/santos                      *
00034  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
00035 import ca.mcgill.sable.soot.*;
00036 import ca.mcgill.sable.soot.jimple.*;
00037 import ca.mcgill.sable.util.*;
00038 import java.util.*;
00039 
00040 public final class JumpElimination {
00041 /**
00042  * 
00043  * @param body ca.mcgill.sable.soot.jimple.JimpleBody
00044  * @param cfanns java.util.Vector
00045  */
00046 public static void eliminate(JimpleBody body) {
00047     StmtList stmtList = body.getStmtList();
00048     Object[] stmts = stmtList.toArray();
00049     StmtGraph g = new CompleteStmtGraph(stmtList);
00050 
00051     for (int i = 0; i < stmts.length; i++) {
00052         try {
00053             boolean remove = false;
00054             if ((i != stmts.length) && (stmts[i] instanceof JGotoStmt)
00055                     && (((JGotoStmt) stmts[i]).getTarget() == stmts[i + 1])) {
00056                 stmtList.remove(stmts[i]);
00057             } else if ((i != stmts.length) && (stmts[i] instanceof JIfStmt)
00058                     && (((JIfStmt) stmts[i]).getTarget() == stmts[i + 1])) {
00059                 stmtList.remove(stmts[i]);
00060             } else if ((i != stmts.length) && (stmts[i] instanceof JGotoStmt)
00061                     && (((JGotoStmt) stmts[i]).getTarget() instanceof JGotoStmt)
00062                     && (((JGotoStmt) ((JGotoStmt) stmts[i]).getTarget()).getTarget() == stmts[i + 1])) {
00063                 stmtList.remove(stmts[i]);
00064             }
00065         } catch (Exception e) {}
00066     }
00067 }
00068 }