1/*
2 * ProGuard -- shrinking, optimization, obfuscation, and preverification
3 *             of Java bytecode.
4 *
5 * Copyright (c) 2002-2014 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.attribute.CodeAttribute;
25import proguard.classfile.constant.*;
26import proguard.classfile.constant.visitor.ConstantVisitor;
27import proguard.classfile.instruction.*;
28import proguard.classfile.instruction.visitor.InstructionVisitor;
29import proguard.classfile.util.SimplifiedVisitor;
30import proguard.classfile.visitor.*;
31
32/**
33 * This InstructionVisitor marks the types of class accesses and class member
34 * accesses of the methods whose instructions it visits.
35 *
36 * @author Eric Lafortune
37 */
38public class AccessMethodMarker
39extends      SimplifiedVisitor
40implements   InstructionVisitor,
41             ConstantVisitor,
42             ClassVisitor,
43             MemberVisitor
44{
45    private Method invokingMethod;
46
47
48    // Implementations for InstructionVisitor.
49
50    public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {}
51
52
53    public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction)
54    {
55        invokingMethod = method;
56
57        clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
58    }
59
60
61    // Implementations for ConstantVisitor.
62
63    public void visitAnyConstant(Clazz clazz, Constant constant) {}
64
65
66    public void visitStringConstant(Clazz clazz, StringConstant stringConstant)
67    {
68        // Check the referenced class or class member, if any.
69       stringConstant.referencedClassAccept(this);
70       stringConstant.referencedMemberAccept(this);
71    }
72
73
74    public void visitInvokeDynamicConstant(Clazz clazz, InvokeDynamicConstant invokeDynamicConstant)
75    {
76        // Check the bootstrap method.
77        invokeDynamicConstant.bootstrapMethodHandleAccept(clazz, this);
78    }
79
80
81    public void visitMethodHandleConstant(Clazz clazz, MethodHandleConstant methodHandleConstant)
82    {
83        // Check the method reference.
84        clazz.constantPoolEntryAccept(methodHandleConstant.u2referenceIndex, this);
85    }
86
87
88    public void visitAnyRefConstant(Clazz clazz, RefConstant refConstant)
89    {
90        // Check the referenced class.
91        clazz.constantPoolEntryAccept(refConstant.u2classIndex, this);
92
93        // Check the referenced class member itself.
94        refConstant.referencedClassAccept(this);
95        refConstant.referencedMemberAccept(this);
96    }
97
98
99    public void visitClassConstant(Clazz clazz, ClassConstant classConstant)
100    {
101        // Check the referenced class.
102       classConstant.referencedClassAccept(this);
103    }
104
105
106    // Implementations for ClassVisitor.
107
108    public void visitAnyClass(Clazz clazz)
109    {
110        int accessFlags = clazz.getAccessFlags();
111
112        if ((accessFlags & ClassConstants.ACC_PUBLIC) == 0)
113        {
114            setAccessesPackageCode(invokingMethod);
115        }
116    }
117
118
119    // Implementations for MemberVisitor.
120
121    public void visitAnyMember(Clazz clazz, Member member)
122    {
123        int accessFlags = member.getAccessFlags();
124
125        if      ((accessFlags & ClassConstants.ACC_PRIVATE)   != 0)
126        {
127            setAccessesPrivateCode(invokingMethod);
128        }
129        else if ((accessFlags & ClassConstants.ACC_PROTECTED) != 0)
130        {
131            setAccessesProtectedCode(invokingMethod);
132        }
133        else if ((accessFlags & ClassConstants.ACC_PUBLIC)    == 0)
134        {
135            setAccessesPackageCode(invokingMethod);
136        }
137    }
138
139
140    // Small utility methods.
141
142    private static void setAccessesPrivateCode(Method method)
143    {
144        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
145        if (info != null)
146        {
147            info.setAccessesPrivateCode();
148        }
149    }
150
151
152    /**
153     * Returns whether the given method accesses private class members.
154     */
155    public static boolean accessesPrivateCode(Method method)
156    {
157        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
158        return info == null || info.accessesPrivateCode();
159    }
160
161
162    private static void setAccessesPackageCode(Method method)
163    {
164        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
165        if (info != null)
166        {
167            info.setAccessesPackageCode();
168        }
169    }
170
171
172    /**
173     * Returns whether the given method accesses package visible classes or class
174     * members.
175     */
176    public static boolean accessesPackageCode(Method method)
177    {
178        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
179        return info == null || info.accessesPackageCode();
180    }
181
182
183    private static void setAccessesProtectedCode(Method method)
184    {
185        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
186        if (info != null)
187        {
188            info.setAccessesProtectedCode();
189        }
190    }
191
192
193    /**
194     * Returns whether the given method accesses protected class members.
195     */
196    public static boolean accessesProtectedCode(Method method)
197    {
198        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
199        return info == null || info.accessesProtectedCode();
200    }
201}
202