1 /*
  2  * Copyright (c) 2022, 2025, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  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  * @bug 8281323
 27  * @summary Check emission of LoadableDescriptors attribute to make sure javac does not emit unneeded entries.
 28  * @enablePreview
 29  * @run main NoUnnecessaryLoadableDescriptorsTest
 30  */
 31 
 32 import java.lang.classfile.Attributes;
 33 import java.lang.classfile.ClassFile;
 34 import java.lang.classfile.ClassModel;
 35 import java.lang.classfile.attribute.LoadableDescriptorsAttribute;
 36 import java.lang.classfile.constantpool.Utf8Entry;
 37 import java.util.List;
 38 
 39 public class NoUnnecessaryLoadableDescriptorsTest {
 40 
 41     public value class LoadableDescriptorsTest1 {
 42         byte b;
 43         public LoadableDescriptorsTest1(byte b) {
 44             this.b = b;
 45         }
 46     }
 47 
 48     public class LoadableDescriptorsTest2 {
 49         static class Inner1 {
 50             static value class Inner2 {}
 51             Inner2 inner;
 52         }
 53     }
 54 
 55     public static void main(String[] args) throws Exception {
 56         ClassModel cls;
 57         LoadableDescriptorsAttribute loadableDescriptors;
 58 
 59         // There should be no LoadableDescriptors attribute in NoUnnecessaryLoadableDescriptorsTest.class
 60         try (var in = NoUnnecessaryLoadableDescriptorsTest.class.getResourceAsStream("NoUnnecessaryLoadableDescriptorsTest.class")) {
 61             cls = ClassFile.of().parse(in.readAllBytes());
 62         }
 63 
 64         /* Check emission of LoadableDescriptors attribute */
 65         if (cls.findAttribute(Attributes.loadableDescriptors()).isPresent()) {
 66             throw new AssertionError("Unexpected LoadableDescriptors attribute!");
 67         }
 68 
 69         // There should be no LoadableDescriptors attribute in NoUnnecessaryLoadableDescriptorsTest$LoadableDescriptorsTest1.class
 70         try (var in = NoUnnecessaryLoadableDescriptorsTest.class.getResourceAsStream("NoUnnecessaryLoadableDescriptorsTest$LoadableDescriptorsTest1.class")) {
 71             cls = ClassFile.of().parse(in.readAllBytes());
 72         }
 73 
 74         /* Check emission of LoadableDescriptors attribute */
 75         if (cls.findAttribute(Attributes.loadableDescriptors()).isPresent()) {
 76             throw new AssertionError("Unexpected LoadableDescriptors attribute!");
 77         }
 78 
 79         // There should be no LoadableDescriptors attribute in NoUnnecessaryLoadableDescriptorsTest$LoadableDescriptorsTest2.class
 80         try (var in = NoUnnecessaryLoadableDescriptorsTest.class.getResourceAsStream("NoUnnecessaryLoadableDescriptorsTest$LoadableDescriptorsTest2.class")) {
 81             cls = ClassFile.of().parse(in.readAllBytes());
 82         }
 83 
 84         /* Check emission of LoadableDescriptors attribute */
 85         if (cls.findAttribute(Attributes.loadableDescriptors()).isPresent()) {
 86             throw new AssertionError("Unexpected LoadableDescriptors attribute!");
 87         }
 88 
 89         // There should be no LoadableDescriptors attribute in NoUnnecessaryLoadableDescriptorsTest$LoadableDescriptorsTest2$Inner2.class
 90         try (var in = NoUnnecessaryLoadableDescriptorsTest.class.getResourceAsStream("NoUnnecessaryLoadableDescriptorsTest$LoadableDescriptorsTest2$Inner1$Inner2.class")) {
 91             cls = ClassFile.of().parse(in.readAllBytes());
 92         }
 93 
 94         /* Check emission of LoadableDescriptors attribute */
 95         if (cls.findAttribute(Attributes.loadableDescriptors()).isPresent()) {
 96             throw new AssertionError("Unexpected LoadableDescriptors attribute!");
 97         }
 98 
 99         // There should be ONE LoadableDescriptors attribute entry in NoUnnecessaryLoadableDescriptorsTest$LoadableDescriptorsTest2$Inner1.class
100         try (var in = NoUnnecessaryLoadableDescriptorsTest.class.getResourceAsStream("NoUnnecessaryLoadableDescriptorsTest$LoadableDescriptorsTest2$Inner1.class")) {
101             cls = ClassFile.of().parse(in.readAllBytes());
102         }
103 
104         if (cls == null) {
105             throw new AssertionError("Could not locate the class files");
106         }
107 
108         /* Check emission of LoadableDescriptors attribute */
109         loadableDescriptors = cls.findAttribute(Attributes.loadableDescriptors()).orElseThrow();
110 
111         List<String> expected = List.of("LNoUnnecessaryLoadableDescriptorsTest$LoadableDescriptorsTest2$Inner1$Inner2;");
112         List<String> found = loadableDescriptors.loadableDescriptors().stream().map(Utf8Entry::stringValue).toList();
113         if (!expected.equals(found)) {
114             throw new AssertionError("Expected one LoadableDescriptors class entry Inner2, but found " + found);
115         }
116     }
117 }