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
|
/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2009 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.classfile.editor;
import proguard.classfile.*;
import proguard.classfile.attribute.*;
import java.util.Arrays;
/**
* This class can add and delete interfaces to and from classes. References to
* the constant pool must be filled out beforehand.
*
* @author Eric Lafortune
*/
public class InterfacesEditor
{
private final ProgramClass targetClass;
/**
* Creates a new InterfacesEditor that will edit interfaces in the given
* target class.
*/
public InterfacesEditor(ProgramClass targetClass)
{
this.targetClass = targetClass;
}
/**
* Adds the specified interface to the target class, if it isn't present yet.
*/
public void addInterface(int interfaceConstantIndex)
{
// Is the interface not yet present?
if (findInterfaceIndex(interfaceConstantIndex) < 0)
{
int interfacesCount = targetClass.u2interfacesCount++;
int[] interfaces = targetClass.u2interfaces;
// Is the array too small to contain the additional interface?
if (interfaces.length <= interfacesCount)
{
// Create a new array and copy the interfaces into it.
int[] newinterfaces = new int[interfacesCount + 1];
System.arraycopy(interfaces, 0, newinterfaces, 0, interfacesCount);
interfaces = newinterfaces;
targetClass.u2interfaces = interfaces;
}
// Append the interface.
interfaces[interfacesCount] = interfaceConstantIndex;
}
}
/**
* Deletes the given interface from the target class, if it is present.
*/
public void deleteInterface(int interfaceConstantIndex)
{
// Is the interface already present?
int interfaceIndex = findInterfaceIndex(interfaceConstantIndex);
if (interfaceIndex >= 0)
{
int interfacesCount = --targetClass.u2interfacesCount;
int[] interfaces = targetClass.u2interfaces;
// Shift the other interfaces in the array.
for (int index = interfaceIndex; index < interfacesCount; index++)
{
interfaces[index] = interfaces[index + 1];
}
// Clear the remaining entry in the array.
interfaces[interfacesCount] = 0;
}
}
// Small utility methods.
/**
* Finds the index of the specified interface in the list of interfaces of
* the target class.
*/
private int findInterfaceIndex(int interfaceConstantIndex)
{
int interfacesCount = targetClass.u2interfacesCount;
int[] interfaces = targetClass.u2interfaces;
for (int index = 0; index < interfacesCount; index++)
{
if (interfaces[index] == interfaceConstantIndex)
{
return index;
}
}
return -1;
}
}
|