ExceptionsAttributeEditor.java revision b72c5c2e5482cf10117b2b25f642f7616b2326c3 
1/*
2 * ProGuard -- shrinking, optimization, obfuscation, and preverification
3 *             of Java bytecode.
4 *
5 * Copyright (c) 2002-2009 Eric Lafortune (eric@graphics.cornell.edu)
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the Free
9 * Software Foundation; either version 2 of the License, or (at your option)
10 * any later version.
11 *
12 * This program is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21package proguard.classfile.editor;
22
23import proguard.classfile.attribute.ExceptionsAttribute;
24
25/**
26 * This class can add exceptions to a given exceptions attribute.
27 * Exceptions to be added must have been added to the constant pool and filled
28 * out beforehand.
29 *
30 * @author Eric Lafortune
31 */
32public class ExceptionsAttributeEditor
33{
34    private ExceptionsAttribute targetExceptionsAttribute;
35
36
37    /**
38     * Creates a new ExceptionsAttributeEditor that will edit exceptions in the
39     * given exceptions attribute.
40     */
41    public ExceptionsAttributeEditor(ExceptionsAttribute targetExceptionsAttribute)
42    {
43        this.targetExceptionsAttribute = targetExceptionsAttribute;
44    }
45
46
47    /**
48     * Adds a given exception to the exceptions attribute.
49     */
50    public void addException(int exceptionIndex)
51    {
52        int   exceptionIndexTableLength = targetExceptionsAttribute.u2exceptionIndexTableLength;
53        int[] exceptionIndexTable       = targetExceptionsAttribute.u2exceptionIndexTable;
54
55        // Make sure there is enough space for the new exception.
56        if (exceptionIndexTable.length <= exceptionIndexTableLength)
57        {
58            targetExceptionsAttribute.u2exceptionIndexTable = new int[exceptionIndexTableLength+1];
59            System.arraycopy(exceptionIndexTable, 0,
60                             targetExceptionsAttribute.u2exceptionIndexTable, 0,
61                             exceptionIndexTableLength);
62            exceptionIndexTable = targetExceptionsAttribute.u2exceptionIndexTable;
63        }
64
65        // Add the exception.
66        exceptionIndexTable[targetExceptionsAttribute.u2exceptionIndexTableLength++] = exceptionIndex;
67    }
68}
69