ExceptionInfoAdder.java revision 9f606f95f03a75961498803e24bee6799a7c0885 
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.*;
24import proguard.classfile.attribute.*;
25import proguard.classfile.attribute.visitor.ExceptionInfoVisitor;
26
27/**
28 * This ExceptionInfoVisitor adds all exception information that it visits to
29 * the given target code attribute.
30 *
31 * @author Eric Lafortune
32 */
33public class ExceptionInfoAdder
34implements   ExceptionInfoVisitor
35{
36    private final ConstantAdder         constantAdder;
37    private final CodeAttributeComposer codeAttributeComposer;
38
39
40    /**
41     * Creates a new ExceptionAdder that will copy exceptions into the given
42     * target code attribute.
43     */
44    public ExceptionInfoAdder(ProgramClass          targetClass,
45                              CodeAttributeComposer targetComposer)
46    {
47        constantAdder         = new ConstantAdder(targetClass);
48        codeAttributeComposer = targetComposer;
49    }
50
51
52    // Implementations for ExceptionInfoVisitor.
53
54    public void visitExceptionInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, ExceptionInfo exceptionInfo)
55    {
56        // Create a copy of the exception info.
57        ExceptionInfo newExceptionInfo =
58            new ExceptionInfo(exceptionInfo.u2startPC,
59                              exceptionInfo.u2endPC,
60                              exceptionInfo.u2handlerPC,
61                              exceptionInfo.u2catchType == 0 ? 0 :
62                                  constantAdder.addConstant(clazz, exceptionInfo.u2catchType));
63
64        // Add the completed exception info.
65        codeAttributeComposer.appendException(newExceptionInfo);
66    }
67}