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.commons.compress.harmony.unpack200.bytecode;
18
19 import java.io.DataOutputStream;
20 import java.io.IOException;
21 import java.util.List;
22
23 /**
24 * An entry in an exception table.
25 */
26 public class ExceptionTableEntry {
27
28 private final int startPC;
29 private final int endPC;
30 private final int handlerPC;
31 private final CPClass catchType;
32
33 private int startPcRenumbered;
34 private int endPcRenumbered;
35 private int handlerPcRenumbered;
36 private int catchTypeIndex;
37
38 /**
39 * Constructs a new ExceptionTableEntry. Exception tables are of two kinds: either a normal one (with a Throwable as the catchType) or a finally clause
40 * (which has no catchType). In the class file, the finally clause is represented as catchType == 0.
41 *
42 * To create a finally clause with this method, pass in null for the catchType.
43 *
44 * @param startPC int
45 * @param endPC int
46 * @param handlerPC int
47 * @param catchType CPClass (if it's a normal catch) or null (if it's a finally clause).
48 */
49 public ExceptionTableEntry(final int startPC, final int endPC, final int handlerPC, final CPClass catchType) {
50 this.startPC = startPC;
51 this.endPC = endPC;
52 this.handlerPC = handlerPC;
53 this.catchType = catchType;
54 }
55
56 public CPClass getCatchType() {
57 return catchType;
58 }
59
60 public void renumber(final List<Integer> byteCodeOffsets) {
61 startPcRenumbered = byteCodeOffsets.get(startPC).intValue();
62 final int endPcIndex = startPC + endPC;
63 endPcRenumbered = byteCodeOffsets.get(endPcIndex).intValue();
64 final int handlerPcIndex = endPcIndex + handlerPC;
65 handlerPcRenumbered = byteCodeOffsets.get(handlerPcIndex).intValue();
66 }
67
68 public void resolve(final ClassConstantPool pool) {
69 if (catchType == null) {
70 // If the catch type is a finally clause
71 // the index is always 0.
72 catchTypeIndex = 0;
73 return;
74 }
75 catchType.resolve(pool);
76 catchTypeIndex = pool.indexOf(catchType);
77 }
78
79 public void write(final DataOutputStream dos) throws IOException {
80 dos.writeShort(startPcRenumbered);
81 dos.writeShort(endPcRenumbered);
82 dos.writeShort(handlerPcRenumbered);
83 dos.writeShort(catchTypeIndex);
84 }
85 }