1/*
2 * ProGuard -- shrinking, optimization, obfuscation, and preverification
3 *             of Java bytecode.
4 *
5 * Copyright (c) 2002-2013 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.peephole;
22
23import proguard.classfile.*;
24import proguard.classfile.util.*;
25import proguard.classfile.visitor.*;
26import proguard.optimize.KeepMarker;
27
28/**
29 * This <code>MemberVisitor</code> makes the program methods that it visits
30 * final, if possible.
31 *
32 * @author Eric Lafortune
33 */
34public class MethodFinalizer
35extends      SimplifiedVisitor
36implements   MemberVisitor
37{
38    private final MemberVisitor extraMemberVisitor;
39
40    private final MemberFinder memberFinder = new MemberFinder();
41
42
43    /**
44     * Creates a new ClassFinalizer.
45     */
46    public MethodFinalizer()
47    {
48        this(null);
49    }
50
51
52    /**
53     * Creates a new ClassFinalizer.
54     * @param extraMemberVisitor an optional extra visitor for all finalized
55     *                           methods.
56     */
57    public MethodFinalizer(MemberVisitor extraMemberVisitor)
58    {
59        this.extraMemberVisitor = extraMemberVisitor;
60    }
61
62
63    // Implementations for MemberVisitor.
64
65    public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod)
66    {
67        String name = programMethod.getName(programClass);
68
69        // If the method is not already private/static/final/abstract,
70        // and it is not a constructor,
71        // and its class is final,
72        //     or it is not being kept and it is not overridden,
73        // then make it final.
74        if ((programMethod.u2accessFlags & (ClassConstants.INTERNAL_ACC_PRIVATE |
75                                            ClassConstants.INTERNAL_ACC_STATIC  |
76                                            ClassConstants.INTERNAL_ACC_FINAL   |
77                                            ClassConstants.INTERNAL_ACC_ABSTRACT)) == 0 &&
78            !name.equals(ClassConstants.INTERNAL_METHOD_NAME_INIT)                      &&
79            ((programClass.u2accessFlags & ClassConstants.INTERNAL_ACC_FINAL) != 0 ||
80             (!KeepMarker.isKept(programMethod) &&
81              (programClass.subClasses == null ||
82               !memberFinder.isOverriden(programClass, programMethod)))))
83        {
84            programMethod.u2accessFlags |= ClassConstants.INTERNAL_ACC_FINAL;
85
86            // Visit the method, if required.
87            if (extraMemberVisitor != null)
88            {
89                extraMemberVisitor.visitProgramMethod(programClass, programMethod);
90            }
91        }
92    }
93}