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.attribute.CodeAttribute;
25import proguard.classfile.constant.RefConstant;
26import proguard.classfile.constant.visitor.ConstantVisitor;
27import proguard.classfile.instruction.*;
28import proguard.classfile.instruction.visitor.InstructionVisitor;
29import proguard.classfile.util.SimplifiedVisitor;
30
31/**
32 * This InstructionVisitor marks all methods that invoke super methods (other
33 * than initializers) from the instructions that it visits.
34 *
35 * @author Eric Lafortune
36 */
37public class SuperInvocationMarker
38extends      SimplifiedVisitor
39implements   InstructionVisitor,
40             ConstantVisitor
41{
42    private boolean invokesSuperMethods;
43
44
45    // Implementations for InstructionVisitor.
46
47    public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {}
48
49
50    public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction)
51    {
52        if (constantInstruction.opcode == InstructionConstants.OP_INVOKESPECIAL)
53        {
54            invokesSuperMethods = false;
55
56            clazz.constantPoolEntryAccept(constantInstruction.constantIndex, this);
57
58            if (invokesSuperMethods)
59            {
60                setInvokesSuperMethods(method);
61            }
62        }
63    }
64
65
66    // Implementations for ConstantVisitor.
67
68    public void visitAnyMethodrefConstant(Clazz clazz, RefConstant refConstant)
69    {
70        invokesSuperMethods =
71            !clazz.equals(refConstant.referencedClass) &&
72            !refConstant.getName(clazz).equals(ClassConstants.INTERNAL_METHOD_NAME_INIT);
73    }
74
75
76    // Small utility methods.
77
78    private static void setInvokesSuperMethods(Method method)
79    {
80        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
81        if (info != null)
82        {
83            info.setInvokesSuperMethods();
84        }
85    }
86
87
88    public static boolean invokesSuperMethods(Method method)
89    {
90        MethodOptimizationInfo info = MethodOptimizationInfo.getMethodOptimizationInfo(method);
91        return info == null || info.invokesSuperMethods();
92    }
93}
94