jode/jode/RemoveNop.java

/* 
 * RemoveNop (c) 1998 Jochen Hoenicke
 *
 * You may distribute under the terms of the GNU General Public License.
 *
 * IN NO EVENT SHALL JOCHEN HOENICKE BE LIABLE TO ANY PARTY FOR DIRECT,
 * INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF
 * THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF JOCHEN HOENICKE 
 * HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * JOCHEN HOENICKE SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS"
 * BASIS, AND JOCHEN HOENICKE HAS NO OBLIGATION TO PROVIDE MAINTENANCE,
 * SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 * $Id$
 */

package jode; 

public class RemoveNop implements Transformation {
    public InstructionHeader transform (InstructionHeader ih) {
        Instruction pred;
        try {
            NopOperator op = (NopOperator) ih.getInstruction();
            if (op == null)
                return null;
            ih = ih.getSimpleUniquePredecessor();
            pred = ih.getInstruction();
            if (pred == null)
                return null;
        } catch (NullPointerException ex) {
            return null;
        } catch (ClassCastException ex) {
            return null;
        }
        return ih.combine(2, pred);
    }
}