SameOneFrame.java revision b9cc48a43ed984587c939d02fba5316bf5c0df6e 
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.classfile.attribute.preverification;
22
23import proguard.classfile.*;
24import proguard.classfile.attribute.CodeAttribute;
25import proguard.classfile.attribute.preverification.visitor.*;
26
27/**
28 * This StackMapFrame represents a "same locals 1 stack item frame" or a
29 * "same locals 1 stack item frame extended".
30 *
31 * @author Eric Lafortune
32 */
33public class SameOneFrame extends StackMapFrame
34{
35    public VerificationType stackItem;
36
37
38    /**
39     * Creates an uninitialized SameOneFrame.
40     */
41    public SameOneFrame()
42    {
43    }
44
45
46    /**
47     * Creates a SameOneFrame with the given tag.
48     */
49    public SameOneFrame(int tag)
50    {
51        u2offsetDelta = tag - SAME_ONE_FRAME;
52    }
53
54
55    /**
56     * Creates a SameOneFrame with the given stack verification type.
57     */
58    public SameOneFrame(VerificationType stackItem)
59    {
60        this.stackItem = stackItem;
61    }
62
63
64    /**
65     * Applies the given verification type visitor to the stack item.
66     */
67    public void stackItemAccept(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, VerificationTypeVisitor verificationTypeVisitor)
68    {
69        stackItem.accept(clazz, method, codeAttribute, offset, verificationTypeVisitor);
70    }
71
72
73    // Implementations for StackMapFrame.
74
75    public int getTag()
76    {
77        return u2offsetDelta < 64 ?
78            SAME_ONE_FRAME + u2offsetDelta :
79            SAME_ONE_FRAME_EXTENDED;
80    }
81
82
83    public void accept(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, StackMapFrameVisitor stackMapFrameVisitor)
84    {
85        stackMapFrameVisitor.visitSameOneFrame(clazz, method, codeAttribute, offset, this);
86    }
87
88
89    // Implementations for Object.
90
91    public boolean equals(Object object)
92    {
93        if (!super.equals(object))
94        {
95            return false;
96        }
97
98        SameOneFrame other = (SameOneFrame)object;
99
100        return this.u2offsetDelta == other.u2offsetDelta &&
101               this.stackItem.equals(other.stackItem);
102    }
103
104
105    public int hashCode()
106    {
107        return super.hashCode() ^ stackItem.hashCode();
108    }
109
110
111    public String toString()
112    {
113        return super.toString()+"Var: ..., Stack: ["+stackItem.toString()+"]";
114    }
115}
116