1 /*
 2  * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 4  *
 5  * This code is free software; you can redistribute it and/or modify it
 6  * under the terms of the GNU General Public License version 2 only, as
 7  * published by the Free Software Foundation.
 8  *
 9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
21  * questions.
22  */
23 
24 /*
25  * @test
26  * @library /test/lib
27  * @enablePreview
28  * @run testng/othervm HiddenValueClass
29  * @summary Test that a value class can be defined as a hidden class
30  */
31 
32 import java.lang.invoke.MethodHandles;
33 import static java.lang.invoke.MethodType.*;
34 import java.nio.file.Files;
35 import java.nio.file.Path;
36 import java.nio.file.Paths;
37 
38 import jdk.test.lib.Utils;
39 
40 import org.testng.annotations.Test;
41 
42 public class HiddenValueClass {
43     private static final Path CLASSES_DIR = Paths.get(Utils.TEST_CLASSES);
44 
45     /*
46      * Defines ValueImpl as a hidden class.
47      */
48     @Test
49     public void hiddenValueClass() throws Throwable {
50         byte[] bytes = Files.readAllBytes(CLASSES_DIR.resolve("ValueImpl.class"));
51         var lookup = MethodHandles.lookup().defineHiddenClass(bytes, false);
52         var mh = lookup.findConstructor(lookup.lookupClass(), methodType(void.class))
53                                     .asType(methodType(Runnable.class));
54         Runnable r = (Runnable)mh.invokeExact();
55         r.run();
56     }
57 }
58 
59 value class ValueImpl implements Runnable {
60     public void run() {}
61 }