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.optimize.info;
22
23import proguard.classfile.*;
24import proguard.classfile.constant.*;
25import proguard.classfile.constant.visitor.ConstantVisitor;
26import proguard.classfile.util.SimplifiedVisitor;
27import proguard.classfile.visitor.*;
28
29/**
30 * This ClassVisitor marks all class members that can not be made private in the
31 * classes that it visits, and in the classes to which they refer.
32 *
33 * @author Eric Lafortune
34 */
35public class NonPrivateMemberMarker
36extends      SimplifiedVisitor
37implements   ClassVisitor,
38             ConstantVisitor,
39             MemberVisitor
40{
41    private final MethodImplementationFilter filteredMethodMarker = new MethodImplementationFilter(this);
42
43
44    // Implementations for ClassVisitor.
45
46    public void visitProgramClass(ProgramClass programClass)
47    {
48        // Mark all referenced class members in different classes.
49        programClass.constantPoolEntriesAccept(this);
50
51        // Explicitly mark the <clinit> method.
52        programClass.methodAccept(ClassConstants.INTERNAL_METHOD_NAME_CLINIT,
53                                  ClassConstants.INTERNAL_METHOD_TYPE_CLINIT,
54                                  this);
55
56        // Explicitly mark the parameterless <init> method.
57        programClass.methodAccept(ClassConstants.INTERNAL_METHOD_NAME_INIT,
58                                  ClassConstants.INTERNAL_METHOD_TYPE_INIT,
59                                  this);
60
61        // Mark all methods that may have implementations.
62        programClass.methodsAccept(filteredMethodMarker);
63    }
64
65
66    public void visitLibraryClass(LibraryClass libraryClass)
67    {
68        // Go over all methods.
69        libraryClass.methodsAccept(this);
70    }
71
72
73    // Implementations for ConstantVisitor.
74
75    public void visitAnyConstant(Clazz clazz, Constant constant) {}
76
77
78    public void visitStringConstant(Clazz clazz, StringConstant stringConstant)
79    {
80        Clazz referencedClass = stringConstant.referencedClass;
81
82        // Is it refering to another class or class member?
83        if (referencedClass != null &&
84            !referencedClass.equals(clazz))
85        {
86            // The referenced class member, if any, can never be made private.
87            stringConstant.referencedMemberAccept(this);
88        }
89    }
90
91
92    public void visitAnyRefConstant(Clazz clazz, RefConstant refConstant)
93    {
94        Clazz referencedClass = refConstant.referencedClass;
95
96        // Is it refering to a class member in another class?
97        // The class member might be in another class, or
98        // it may be referenced through another class.
99        if (referencedClass != null &&
100            !referencedClass.equals(clazz) ||
101            !refConstant.getClassName(clazz).equals(clazz.getName()))
102        {
103            // The referenced class member can never be made private.
104            refConstant.referencedMemberAccept(this);
105        }
106    }
107
108
109    // Implementations for MemberVisitor.
110
111    public void visitProgramField(ProgramClass programClass, ProgramField programField)
112    {
113        markCanNotBeMadePrivate(programField);
114    }
115
116
117    public void visitLibraryField(LibraryClass libraryClass, LibraryField libraryField)
118    {
119        markCanNotBeMadePrivate(libraryField);
120    }
121
122
123    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)
124    {
125        markCanNotBeMadePrivate(programMethod);
126    }
127
128
129    public void visitLibraryMethod(LibraryClass libraryClass, LibraryMethod libraryMethod)
130    {
131        markCanNotBeMadePrivate(libraryMethod);
132    }
133
134
135    // Small utility methods.
136
137    private static void markCanNotBeMadePrivate(Field field)
138    {
139        FieldOptimizationInfo info = FieldOptimizationInfo.getFieldOptimizationInfo(field);
140        if (info != null)
141        {
142            info.setCanNotBeMadePrivate();
143        }
144    }
145
146
147    /**
148     * Returns whether the given field can be made private.
149     */
150    public static boolean canBeMadePrivate(Field field)
151    {
152        FieldOptimizationInfo info = FieldOptimizationInfo.getFieldOptimizationInfo(field);
153        return info != null &&
154               info.canBeMadePrivate();
155    }
156
157
158    private static void markCanNotBeMadePrivate(Method method)
159    {
160        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
161        if (info != null)
162        {
163            info.setCanNotBeMadePrivate();
164        }
165    }
166
167
168    /**
169     * Returns whether the given method can be made private.
170     */
171    public static boolean canBeMadePrivate(Method method)
172    {
173        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
174        return info != null &&
175               info.canBeMadePrivate();
176    }
177}
178