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.util.SimplifiedVisitor;
25
26/**
27 * This <code>MemberVisitor</code> lets a given <code>MemberVisitor</code>
28 * travel to all concrete and abstract implementations of the visited methods
29 * in their class hierarchies.
30 *
31 * @author Eric Lafortune
32 */
33public class MethodImplementationTraveler
34extends      SimplifiedVisitor
35implements   MemberVisitor
36{
37    private final boolean       visitThisMethod;
38    private final boolean       visitSuperMethods;
39    private final boolean       visitInterfaceMethods;
40    private final boolean       visitOverridingMethods;
41    private final MemberVisitor memberVisitor;
42
43
44    /**
45     * Creates a new MethodImplementationTraveler.
46     * @param visitThisMethod        specifies whether to visit the originally
47     *                               visited methods.
48     * @param visitSuperMethods      specifies whether to visit the method in
49     *                               the super classes.
50     * @param visitInterfaceMethods  specifies whether to visit the method in
51     *                               the interface classes.
52     * @param visitOverridingMethods specifies whether to visit the method in
53     *                               the subclasses.
54     * @param memberVisitor          the <code>MemberVisitor</code> to which
55     *                               visits will be delegated.
56     */
57    public MethodImplementationTraveler(boolean       visitThisMethod,
58                                        boolean       visitSuperMethods,
59                                        boolean       visitInterfaceMethods,
60                                        boolean       visitOverridingMethods,
61                                        MemberVisitor memberVisitor)
62    {
63        this.visitThisMethod        = visitThisMethod;
64        this.visitSuperMethods      = visitSuperMethods;
65        this.visitInterfaceMethods  = visitInterfaceMethods;
66        this.visitOverridingMethods = visitOverridingMethods;
67        this.memberVisitor          = memberVisitor;
68    }
69
70
71    // Implementations for MemberVisitor.
72
73    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)
74    {
75        if (visitThisMethod)
76        {
77            programMethod.accept(programClass, memberVisitor);
78        }
79
80        if (!isSpecial(programClass, programMethod))
81        {
82            programClass.hierarchyAccept(false,
83                                         visitSuperMethods,
84                                         visitInterfaceMethods,
85                                         visitOverridingMethods,
86                                         new NamedMethodVisitor(programMethod.getName(programClass),
87                                                                programMethod.getDescriptor(programClass),
88                                         new MemberAccessFilter(0,
89                                                                ClassConstants.INTERNAL_ACC_PRIVATE |
90                                                                ClassConstants.INTERNAL_ACC_STATIC,
91                                         memberVisitor)));
92        }
93    }
94
95
96    public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod)
97    {
98        if (visitThisMethod)
99        {
100            libraryMethod.accept(libraryClass, memberVisitor);
101        }
102
103        if (!isSpecial(libraryClass, libraryMethod))
104        {
105            libraryClass.hierarchyAccept(false,
106                                         visitSuperMethods,
107                                         visitInterfaceMethods,
108                                         visitOverridingMethods,
109                                         new NamedMethodVisitor(libraryMethod.getName(libraryClass),
110                                                                libraryMethod.getDescriptor(libraryClass),
111                                         new MemberAccessFilter(0,
112                                                                ClassConstants.INTERNAL_ACC_PRIVATE |
113                                                                ClassConstants.INTERNAL_ACC_STATIC,
114                                         memberVisitor)));
115        }
116    }
117
118
119    // Small utility methods.
120
121    private boolean isSpecial(Clazz clazz, Method method)
122    {
123        return (method.getAccessFlags() &
124                (ClassConstants.INTERNAL_ACC_PRIVATE |
125                 ClassConstants.INTERNAL_ACC_STATIC)) != 0 ||
126               method.getName(clazz).equals(ClassConstants.INTERNAL_METHOD_NAME_INIT);
127    }
128}
129