ExceptionExcludedOffsetFilter.java revision db267bc191f906f55eaef21a27110cce2ec57fdf 
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.visitor;
22
23import proguard.classfile.*;
24import proguard.classfile.attribute.*;
25import proguard.classfile.attribute.visitor.ExceptionInfoVisitor;
26
27/**
28 * This <code>ExceptionInfoVisitor</code> delegates its visits to another given
29 * <code>ExceptionInfoVisitor</code>, but only when the visited exception
30 * does not cover the instruction at the given offset.
31 *
32 * @author Eric Lafortune
33 */
34public class ExceptionExcludedOffsetFilter
35implements   ExceptionInfoVisitor
36{
37    private final int                  instructionOffset;
38    private final ExceptionInfoVisitor exceptionInfoVisitor;
39
40
41    /**
42     * Creates a new ExceptionExcludedOffsetFilter.
43     * @param instructionOffset    the instruction offset.
44     * @param exceptionInfoVisitor the ExceptionInfoVisitor to which visits
45     *                             will be delegated.
46     */
47    public ExceptionExcludedOffsetFilter(int                  instructionOffset,
48                                         ExceptionInfoVisitor exceptionInfoVisitor)
49    {
50        this.instructionOffset    = instructionOffset;
51        this.exceptionInfoVisitor = exceptionInfoVisitor;
52    }
53
54
55    // Implementations for ExceptionInfoVisitor.
56
57    public void visitExceptionInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, ExceptionInfo exceptionInfo)
58    {
59        if (!exceptionInfo.isApplicable(instructionOffset))
60        {
61            exceptionInfoVisitor.visitExceptionInfo(clazz, method, codeAttribute, exceptionInfo);
62        }
63    }
64}
65