1 /*
 2  * Copyright (c) 2025, 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  * @summary Test that IsIdentityClass and modifiers return true for arrays that can be flattened.
27  * @library /test/lib
28  * @enablePreview false
29  * @modules java.base/jdk.internal.misc
30  *          java.base/jdk.internal.value
31  * @run junit/othervm IsIdentityClassTest
32  * @run junit/othervm --enable-preview IsIdentityClassTest
33  */
34 
35 import org.junit.jupiter.api.Test;
36 
37 import java.lang.reflect.AccessFlag;
38 import java.lang.reflect.Modifier;
39 import java.util.Set;
40 
41 import jdk.internal.misc.PreviewFeatures;
42 
43 import static jdk.test.lib.Asserts.*;
44 
45 public class IsIdentityClassTest {
46 
47     @Test
48     void testIsIdentityClass() {
49         assertEquals(!PreviewFeatures.isEnabled(), Integer.class.isIdentity(), "Integer is not an IDENTITY type");
50         assertTrue(Integer[].class.isIdentity(), "Arrays of inline types are IDENTITY types");
51     }
52 
53     @Test
54     void testModifiers() {
55         // Without --enable-preview (before Valhalla), there was no IDENTITY modifier.
56         // With --enable-preview, Integer still should not have the IDENTITY modifier.
57         // So only verify this in preview mode.
58         if (PreviewFeatures.isEnabled()) {
59             int imod = Integer.class.getModifiers();
60             assertFalse(Modifier.isIdentity(imod), "Modifier of Integer should not have IDENTITY set");
61         }
62         int amod = Integer[].class.getModifiers();
63         assertEquals(PreviewFeatures.isEnabled(), Modifier.isIdentity(amod), "Modifier of array should have IDENTITY set");
64     }
65 
66     @Test
67     void testAccessFlags() {
68         // Without --enable-preview (before Valhalla), there was no IDENTITY accessflag.
69         // With --enable-preview, Integer still should not have the IDENTITY accessflag.
70         // So only verify this in preview mode.
71         if (PreviewFeatures.isEnabled()) {
72             Set<AccessFlag> iacc = Integer.class.accessFlags();
73             assertFalse(iacc.contains(AccessFlag.IDENTITY), "Access flags should not contain IDENTITY");
74         }
75         // AccessFlags for arrays set the IDENTITY accessflag.
76         Set<AccessFlag> aacc = Integer[].class.accessFlags();
77         assertEquals(PreviewFeatures.isEnabled(), aacc.contains(AccessFlag.IDENTITY), "Access flags of array of inline types should contain IDENTITY");
78     }
79 }