1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2011 Eric Lafortune (eric@graphics.cornell.edu)
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package proguard.obfuscate;
import proguard.classfile.*;
import proguard.classfile.attribute.*;
import proguard.classfile.attribute.visitor.AttributeVisitor;
import proguard.classfile.util.*;
/**
* This AttributeVisitor trims and marks all local variable (type) table
* attributes that it visits. It keeps parameter names and types and removes
* the ordinary local variable names and types.
*
* @author Eric Lafortune
*/
public class ParameterNameMarker
extends SimplifiedVisitor
implements AttributeVisitor
{
private final AttributeVisitor attributeUsageMarker;
/**
* Constructs a new ParameterNameMarker.
* @param attributeUsageMarker the marker that will be used to mark
* attributes containing local variable info.
*/
public ParameterNameMarker(AttributeVisitor attributeUsageMarker)
{
this.attributeUsageMarker = attributeUsageMarker;
}
// Implementations for AttributeVisitor.
public void visitAnyAttribute(Clazz clazz, Attribute attribute) {}
public void visitLocalVariableTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTableAttribute localVariableTableAttribute)
{
if (!AttributeUsageMarker.isUsed(localVariableTableAttribute) &&
hasParameters(clazz, method))
{
// Shift the entries that start at offset 0 to the front.
int newIndex = 0;
for (int index = 0; index < localVariableTableAttribute.u2localVariableTableLength; index++)
{
LocalVariableInfo localVariableInfo =
localVariableTableAttribute.localVariableTable[index];
if (localVariableInfo.u2startPC == 0)
{
localVariableTableAttribute.localVariableTable[newIndex++] =
localVariableInfo;
}
}
// Trim the table.
localVariableTableAttribute.u2localVariableTableLength = newIndex;
// Mark the table if there are any entries.
if (newIndex > 0)
{
attributeUsageMarker.visitLocalVariableTableAttribute(clazz, method, codeAttribute, localVariableTableAttribute);
}
}
}
public void visitLocalVariableTypeTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeTableAttribute localVariableTypeTableAttribute)
{
if (!AttributeUsageMarker.isUsed(localVariableTypeTableAttribute) &&
hasParameters(clazz, method))
{
// Shift the entries that start at offset 0 to the front.
int newIndex = 0;
for (int index = 0; index < localVariableTypeTableAttribute.u2localVariableTypeTableLength; index++)
{
LocalVariableTypeInfo localVariableTypeInfo =
localVariableTypeTableAttribute.localVariableTypeTable[index];
if (localVariableTypeInfo.u2startPC == 0)
{
localVariableTypeTableAttribute.localVariableTypeTable[newIndex++] =
localVariableTypeInfo;
}
}
// Trim the table.
localVariableTypeTableAttribute.u2localVariableTypeTableLength = newIndex;
// Mark the table if there are any entries.
if (newIndex > 0)
{
attributeUsageMarker.visitLocalVariableTypeTableAttribute(clazz, method, codeAttribute, localVariableTypeTableAttribute);
}
}
}
// Small utility methods.
private boolean hasParameters(Clazz clazz, Method method)
{
return method.getDescriptor(clazz).charAt(1) != ClassConstants.INTERNAL_METHOD_ARGUMENTS_CLOSE;
}
}
|