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
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
// Copyright 2017 The Bazel Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.google.devtools.build.android.desugar;
import java.io.IOException;
import java.io.InputStream;
import org.objectweb.asm.Attribute;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassVisitor;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.commons.ClassRemapper;
import org.objectweb.asm.commons.Remapper;
/** Utility class to prefix or unprefix class names of core library classes */
class CoreLibraryRewriter {
private final String prefix;
public CoreLibraryRewriter(String prefix) {
this.prefix = prefix;
}
/**
* Factory method that returns either a normal ClassReader if prefix is empty, or a ClassReader
* with a ClassRemapper that prefixes class names of core library classes if prefix is not empty.
*/
public ClassReader reader(InputStream content) throws IOException {
if (prefix.isEmpty()) {
return new ClassReader(content);
} else {
return new PrefixingClassReader(content, prefix);
}
}
/**
* Factory method that returns a ClassVisitor that delegates to a ClassWriter, removing prefix
* from core library class names if it is not empty.
*/
public UnprefixingClassWriter writer(int flags) {
return new UnprefixingClassWriter(flags);
}
static boolean shouldPrefix(String typeName) {
return (typeName.startsWith("java/") || typeName.startsWith("sun/")) && !except(typeName);
}
private static boolean except(String typeName) {
if (typeName.startsWith("java/lang/invoke/")) {
return true;
}
switch (typeName) {
// Autoboxed types
case "java/lang/Boolean":
case "java/lang/Byte":
case "java/lang/Character":
case "java/lang/Double":
case "java/lang/Float":
case "java/lang/Integer":
case "java/lang/Long":
case "java/lang/Number":
case "java/lang/Short":
// Special types
case "java/lang/Class":
case "java/lang/Object":
case "java/lang/String":
case "java/lang/Throwable":
return true;
default: // fall out
}
return false;
}
/** Removes prefix from class names */
public String unprefix(String typeName) {
if (prefix.isEmpty() || !typeName.startsWith(prefix)) {
return typeName;
}
return typeName.substring(prefix.length());
}
/** ClassReader that prefixes core library class names as they are read */
private static class PrefixingClassReader extends ClassReader {
private final String prefix;
PrefixingClassReader(InputStream content, String prefix) throws IOException {
super(content);
this.prefix = prefix;
}
@Override
public void accept(ClassVisitor cv, Attribute[] attrs, int flags) {
cv =
new ClassRemapper(
cv,
new Remapper() {
@Override
public String map(String typeName) {
return prefix(typeName);
}
});
super.accept(cv, attrs, flags);
}
@Override
public String getClassName() {
return prefix(super.getClassName());
}
@Override
public String getSuperName() {
String result = super.getSuperName();
return result != null ? prefix(result) : null;
}
@Override
public String[] getInterfaces() {
String[] result = super.getInterfaces();
for (int i = 0, len = result.length; i < len; ++i) {
result[i] = prefix(result[i]);
}
return result;
}
/** Prefixes core library class names with prefix. */
private String prefix(String typeName) {
if (shouldPrefix(typeName)) {
return prefix + typeName;
}
return typeName;
}
}
/**
* ClassVisitor that delegates to a ClassWriter, but removes a prefix as each class is written.
* The unprefixing is optimized out if prefix is empty.
*/
public class UnprefixingClassWriter extends ClassVisitor {
private final ClassWriter writer;
UnprefixingClassWriter(int flags) {
super(Opcodes.ASM6);
this.writer = new ClassWriter(flags);
this.cv = this.writer;
if (!prefix.isEmpty()) {
this.cv =
new ClassRemapper(
this.cv,
new Remapper() {
@Override
public String map(String typeName) {
return unprefix(typeName);
}
});
}
}
byte[] toByteArray() {
return writer.toByteArray();
}
}
}
|
