1 /*
 2  * Copyright (c) 2020, 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 package org.openjdk.asmtools.jasm;
24 
25 import java.io.IOException;
26 import java.util.List;
27 
28 /**
29  * Base class of the "classes[]" data of attributes
30  * <p>
31  * JEP 181 (Nest-based Access Control): class file 55.0
32  * NestMembers_attribute {
33  * u2 attribute_name_index;
34  * u4 attribute_length;
35  * u2 number_of_classes;
36  * u2 classes[number_of_classes];
37  * }
38  * <p>
39  * JEP 360 (Sealed types): class file 59.65535
40  * PermittedSubclasses_attribute {
41  * u2 attribute_name_index;
42  * u4 attribute_length;
43  * u2 number_of_classes;
44  * u2 classes[number_of_classes];
45  * }
46  */
47 public class ClassArrayAttr extends AttrData {
48 
49     List<ConstantPool.ConstCell> classes;
50 
51     public ClassArrayAttr(String attributeName, ClassData cdata, List<ConstantPool.ConstCell> classes) {
52         super(cdata, attributeName);
53         this.classes = classes;
54     }
55 
56     @Override
57     public int attrLength() {
58         return 2 + classes.size() * 2;
59     }
60 
61     @Override
62     public void write(CheckedDataOutputStream out) throws IOException {
63         super.write(out);
64         out.writeShort(classes.size());
65         for (ConstantPool.ConstCell c : classes) {
66             out.writeShort(c.arg);
67         }
68     }
69 }