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
|
/*
* Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 8238358 8247444
* @run testng/othervm UnreflectTest
* @summary Test Lookup::unreflectSetter and Lookup::unreflectVarHandle on
* trusted final fields (declared in hidden classes and records)
*/
import java.io.IOException;
import java.io.UncheckedIOException;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.VarHandle;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import org.testng.annotations.Test;
import static org.testng.Assert.*;
public class UnreflectTest {
static final MethodHandles.Lookup LOOKUP = MethodHandles.lookup();
static final Class<?> hiddenClass = defineHiddenClass();
private static Class<?> defineHiddenClass() {
String classes = System.getProperty("test.classes");
Path cf = Paths.get(classes, "Fields.class");
try {
byte[] bytes = Files.readAllBytes(cf);
return MethodHandles.lookup().defineHiddenClass(bytes, true).lookupClass();
} catch (IOException e) {
throw new UncheckedIOException(e);
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
}
}
/*
* Test Lookup::unreflectSetter and Lookup::unreflectVarHandle that
* can write the value of a non-static final field in a normal class
*/
@Test
public void testFieldsInNormalClass() throws Throwable {
// despite the name "HiddenClass", this class is loaded by the
// class loader as non-hidden class
Class<?> c = Fields.class;
Fields o = new Fields();
assertFalse(c.isHidden());
readOnlyAccessibleObject(c, "STATIC_FINAL", null, true);
readWriteAccessibleObject(c, "STATIC_NON_FINAL", null, false);
readWriteAccessibleObject(c, "FINAL", o, true);
readWriteAccessibleObject(c, "NON_FINAL", o, false);
}
/*
* Test Lookup::unreflectSetter and Lookup::unreflectVarHandle that
* has NO write the value of a non-static final field in a hidden class
*/
@Test
public void testFieldsInHiddenClass() throws Throwable {
assertTrue(hiddenClass.isHidden());
Object o = hiddenClass.newInstance();
readOnlyAccessibleObject(hiddenClass, "STATIC_FINAL", null, true);
readWriteAccessibleObject(hiddenClass, "STATIC_NON_FINAL", null, false);
readOnlyAccessibleObject(hiddenClass, "FINAL", o, true);
readWriteAccessibleObject(hiddenClass, "NON_FINAL", o, false);
}
static record TestRecord(int i) {
static final Object STATIC_FINAL = new Object();
static Object STATIC_NON_FINAL = new Object();
}
/*
* Test Lookup::unreflectSetter and Lookup::unreflectVarHandle that
* cannot write the value of a non-static final field in a record class
*/
public void testFieldsInRecordClass() throws Throwable {
assertTrue(TestRecord.class.isRecord());
Object o = new TestRecord(1);
readOnlyAccessibleObject(TestRecord.class, "STATIC_FINAL", null, true);
readWriteAccessibleObject(TestRecord.class, "STATIC_NON_FINAL", null, false);
readOnlyAccessibleObject(TestRecord.class, "i", o, true);
}
/*
* Verify read-only access via unreflectSetter and unreflectVarHandle
*/
private static void readOnlyAccessibleObject(Class<?> c, String name, Object o, boolean isFinal) throws Throwable {
Field f = c.getDeclaredField(name);
int modifier = f.getModifiers();
if (isFinal) {
assertTrue(Modifier.isFinal(modifier));
} else {
assertFalse(Modifier.isFinal(modifier));
}
assertTrue(f.trySetAccessible());
// Field object with read-only access
MethodHandle mh = LOOKUP.unreflectGetter(f);
Object value = Modifier.isStatic(modifier) ? mh.invoke() : mh.invoke(o);
assertTrue(value == f.get(o));
try {
LOOKUP.unreflectSetter(f);
assertTrue(false, "should fail to unreflect a setter for " + name);
} catch (IllegalAccessException e) {
}
VarHandle vh = LOOKUP.unreflectVarHandle(f);
if (isFinal) {
assertFalse(vh.isAccessModeSupported(VarHandle.AccessMode.SET));
} else {
assertTrue(vh.isAccessModeSupported(VarHandle.AccessMode.SET));
}
}
private static void readWriteAccessibleObject(Class<?> c, String name, Object o, boolean isFinal) throws Throwable {
Field f = c.getDeclaredField(name);
int modifier = f.getModifiers();
if (isFinal) {
assertTrue(Modifier.isFinal(modifier));
} else {
assertFalse(Modifier.isFinal(modifier));
}
assertTrue(f.trySetAccessible());
// Field object with read-write access
MethodHandle mh = MethodHandles.lookup().unreflectGetter(f);
Object value = Modifier.isStatic(modifier) ? mh.invoke() : mh.invoke(o);
assertTrue(value == f.get(o));
try {
MethodHandle setter = MethodHandles.lookup().unreflectSetter(f);
if (Modifier.isStatic(modifier)) {
setter.invokeExact(value);
} else {
setter.invoke(o, value);
}
} catch (IllegalAccessException e) {
throw e;
}
VarHandle vh = LOOKUP.unreflectVarHandle(f);
if (isFinal) {
assertFalse(vh.isAccessModeSupported(VarHandle.AccessMode.SET));
} else {
assertTrue(vh.isAccessModeSupported(VarHandle.AccessMode.SET));
}
}
}
|
