1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.bcel.generic;
18
19 /**
20 * Thrown by InstructionList.remove() when one or multiple disposed instructions are still being referenced by an
21 * InstructionTargeter object. I.e. the InstructionTargeter has to be notified that (one of) the InstructionHandle it is
22 * referencing is being removed from the InstructionList and thus not valid anymore.
23 *
24 * <p>
25 * Making this an exception instead of a return value forces the user to handle these case explicitly in a try { ... }
26 * catch. The following code illustrates how this may be done:
27 * </p>
28 *
29 * <PRE>
30 * ...
31 * try {
32 * il.delete(start_ih, end_ih);
33 * } catch (TargetLostException e) {
34 * for (InstructionHandle target : e.getTargets()) {
35 * for (InstructionTargeter targeter : target.getTargeters()) {
36 * targeter.updateTarget(target, new_target);
37 * }
38 * }
39 * }
40 * </PRE>
41 *
42 * @see InstructionHandle
43 * @see InstructionList
44 * @see InstructionTargeter
45 */
46 public final class TargetLostException extends Exception {
47
48 private static final long serialVersionUID = -6857272667645328384L;
49 private final InstructionHandle[] targets;
50
51 TargetLostException(final InstructionHandle[] t, final String mesg) {
52 super(mesg);
53 targets = t;
54 }
55
56 /**
57 * @return list of instructions still being targeted.
58 */
59 public InstructionHandle[] getTargets() {
60 return targets;
61 }
62 }