package org.aspectj.apache.bcel.generic;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
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 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

/**
 * Thrown by InstructionList.remove() when one or multiple disposed instruction
 * are still being referenced by a InstructionTargeter object. I.e. the
 * InstructionTargeter has to be notified that (one of) the InstructionHandle it
 * is referencing is being removed from the InstructionList and thus not valid anymore.
 *
 * Making this an exception instead of a return value forces the user to handle
 * these case explicitely in a try { ... } catch. The following code illustrates
 * how this may be done:
 *
 * <PRE>
 *     ...
 *     try {
 *	il.delete(start_ih, end_ih);
 *     } catch(TargetLostException e) {
 *       InstructionHandle[] targets = e.getTargets();
 *	 for(int i=0; i < targets.length; i++) {
 *	   InstructionTargeter[] targeters = targets[i].getTargeters();
 *     
 *	   for(int j=0; j < targeters.length; j++)
 *	     targeters[j].updateTarget(targets[i], new_target);
 *       }
 *     }
 * </PRE>
 *
 * @see InstructionHandle
 * @see InstructionList
 * @see InstructionTargeter
 * @version $Id: TargetLostException.java,v 1.3 2008/05/28 23:52:55 aclement Exp $
 * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 */
// OPTIMIZE make unchecked, or get rid of it!
public final class TargetLostException extends Exception {
  private InstructionHandle[] targets;

  TargetLostException(InstructionHandle[] t, String mesg) {
    super(mesg);
    targets = t;
  }

  /**
   * @return list of instructions still being targeted.
   */
  public InstructionHandle[] getTargets() { return targets; }
}
