1 /*
2  * Copyright (C) 2014 The Android Open Source Project
3  * Copyright (c) 1996, 2011, Oracle and/or its affiliates. All rights reserved.
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This code is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 only, as
8  * published by the Free Software Foundation.  Oracle designates this
9  * particular file as subject to the "Classpath" exception as provided
10  * by Oracle in the LICENSE file that accompanied this code.
11  *
12  * This code is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15  * version 2 for more details (a copy is included in the LICENSE file that
16  * accompanied this code).
17  *
18  * You should have received a copy of the GNU General Public License version
19  * 2 along with this work; if not, write to the Free Software Foundation,
20  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21  *
22  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
23  * or visit www.oracle.com if you need additional information or have any
24  * questions.
25  */
26 
27 package java.lang;
28 
29 import java.lang.reflect.Method;
30 import libcore.util.EmptyArray;
31 
32 /**
33  * The {@code Void} class is an uninstantiable placeholder class to hold a
34  * reference to the {@code Class} object representing the Java keyword
35  * void.
36  *
37  * @author  unascribed
38  * @since   JDK1.1
39  */
40 public final
41 class Void {
42 
43     /**
44      * The {@code Class} object representing the pseudo-type corresponding to
45      * the keyword {@code void}.
46      */
47     public static final Class<Void> TYPE = lookupType();
48 
49     // Android-changed: Upstream code would use reflection to establish the value of "void.class".
50     // ART makes a native call instead because the reflection approach could lead to initialization
51     // of TYPE with the current, i.e. uninitialized, value of TYPE due to other Android changes.
52     @dalvik.annotation.optimization.FastNative
lookupType()53     private static native Class<Void> lookupType();
54     /*
55     @SuppressWarnings("unchecked")
56     private static Class<Void> lookupType() {
57         try {
58             Method method = Runnable.class.getMethod("run", EmptyArray.CLASS);
59             return (Class<Void>) method.getReturnType();
60         } catch (Exception e) {
61             throw new AssertionError(e);
62         }
63     }
64     */
65 
66     /*
67      * The Void class cannot be instantiated.
68      */
Void()69     private Void() {}
70 }
71