1 /*
2 * Copyright (c) 2016, 2018, 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 package vm.mlvm.tools;
25
26 import java.io.File;
27 import vm.share.UnsafeAccess;
28 import vm.share.FileUtils;
29 import vm.mlvm.share.CustomClassLoaders;
30 import vm.mlvm.anonloader.share.AnonkTestee01;
31
32 import vm.mlvm.share.Env;
33
34 /**
35 * A tool, which loads a class file specified in command line into VM using:
36 * <ul>
37 * <li>A custom class loader,
38 * <li>{@link sun.misc.Unsafe#defineAnonymousClass(Class, byte[], Object[])}
39 * call.
40 * </ul>
41 *
42 * <p>Syntax:
43 * <pre>{@code
44 * $ java [options...] vm.mlvm.tool.LoadClass class-file-name [class-FQDN]
45 * }</pre>
46 *
47 * The first argument, class file name is mandatory.
48 * The second one is optional — a fully qualified class name.
49 * If the second argument is not specified, it is constructed from the first
50 * argument, replacing '/' with '.'
51 *
52 * <p>The tool can be used for investigating failures of vm.mlvm.anon tests.
53 *
54 */
55 public class LoadClass {
56
57 private static final Class<?> HOST_CLASS = AnonkTestee01.class;
58
59 private static void usage() {
60 System.out.println("Usage: java " + LoadClass.class.getName()
61 + " <class-file-to-load> [class-name]");
62 }
63
64 /**
65 * Runs the tool.
66 * @param args Tool arguments
67 */
68 @SuppressWarnings("deprecation")
69 public static void main(String[] args) {
70 if (args.length < 1) {
71 usage();
72 System.exit(1);
73 }
74
75 try {
76 final String classFileName = args[0];
77 final String className = (args.length > 1) ? args[1]
78 : classFileName.replaceAll("\\.class$", "")
79 .replace("/", ".");
80 final byte[] classBytes = FileUtils
81 .readFile(new File(classFileName));
82
83 Env.traceImportant("Loading class '%s' from file '%s'...",
84 className, classFileName);
85
86 Env.traceImportant("...using custom ClassLoader");
87 try {
88 ClassLoader cl = CustomClassLoaders
89 .makeClassBytesLoader(classBytes, className);
90 Class<?> c = cl.loadClass(className);
91 c.newInstance();
92 Env.traceImportant("OK");
93 } catch (Throwable e) {
94 Env.traceImportant(e,
95 "Couldn't load class '%s' via custom ClassLoader",
96 classFileName);
97 }
98
99 Env.traceImportant(
100 "...using sun.misc.Unsafe.defineAnonymousClass():");
101 try {
102 Class<?> c = UnsafeAccess.unsafe.defineAnonymousClass(HOST_CLASS,
103 classBytes, new Object[0]);
104 c.newInstance();
105 Env.traceImportant("OK");
106 } catch (Throwable e) {
107 Env.traceImportant(e, "Couldn't load class '%s' via sun.misc."
108 + "Unsafe.defineAnonymousClass()", classFileName);
109 }
110 } catch (Throwable e) {
111 Env.traceImportant(e, "Can't load class");
112 }
113 }
114 }