AttributeSorter.java revision cfead78069f3dc32998dc118ee08cab3867acea2 
1/*
2 * ProGuard -- shrinking, optimization, obfuscation, and preverification
3 *             of Java bytecode.
4 *
5 * Copyright (c) 2002-2011 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.AttributeVisitor;
26import proguard.classfile.util.SimplifiedVisitor;
27import proguard.classfile.visitor.*;
28
29import java.util.*;
30
31/**
32 * This ClassVisitor sorts the attributes of the classes that it visits.
33 * The sorting order is based on the types of the attributes.
34 *
35 * @author Eric Lafortune
36 */
37public class AttributeSorter
38extends      SimplifiedVisitor
39implements   ClassVisitor, MemberVisitor, AttributeVisitor, Comparator
40{
41    // Implementations for ClassVisitor.
42
43    public void visitProgramClass(ProgramClass programClass)
44    {
45        // Sort the attributes.
46        Arrays.sort(programClass.attributes, 0, programClass.u2attributesCount, this);
47
48        // Sort the attributes of the class members.
49        programClass.fieldsAccept(this);
50        programClass.methodsAccept(this);
51    }
52
53
54    // Implementations for MemberVisitor.
55
56    public void visitProgramMember(ProgramClass programClass, ProgramMember programMember)
57    {
58        // Sort the attributes.
59        Arrays.sort(programMember.attributes, 0, programMember.u2attributesCount, this);
60
61        // Sort the attributes of the attributes.
62        programMember.attributesAccept(programClass, this);
63    }
64
65
66    // Implementations for AttributeVisitor.
67
68    public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}
69
70
71    public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute)
72    {
73        // Sort the attributes.
74        Arrays.sort(codeAttribute.attributes, 0, codeAttribute.u2attributesCount, this);
75    }
76
77
78    // Implementations for Comparator.
79
80    public int compare(Object object1, Object object2)
81    {
82        Attribute attribute1 = (Attribute)object1;
83        Attribute attribute2 = (Attribute)object2;
84
85        return attribute1.u2attributeNameIndex < attribute2.u2attributeNameIndex ? -1 :
86               attribute1.u2attributeNameIndex > attribute2.u2attributeNameIndex ?  1 :
87                                                                                    0;
88    }
89}
90