1/*
2 * Copyright (c) 2014, 2016, 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 * @bug 8076110
27 * @summary Redefine running methods that have cached resolution errors
28 * @library /test/lib
29 * @modules java.base/jdk.internal.misc
30 * @modules java.base/jdk.internal.org.objectweb.asm
31 *          java.instrument
32 *          jdk.jartool/sun.tools.jar
33 * @run main RedefineClassHelper
34 * @run main/othervm -javaagent:redefineagent.jar -Xlog:redefine+class+iklass+add=trace,redefine+class+iklass+purge=trace RedefineRunningMethodsWithResolutionErrors
35 */
36
37import jdk.internal.org.objectweb.asm.ClassWriter;
38import jdk.internal.org.objectweb.asm.Label;
39import jdk.internal.org.objectweb.asm.MethodVisitor;
40import jdk.internal.org.objectweb.asm.Opcodes;
41
42import java.lang.reflect.InvocationTargetException;
43
44public class RedefineRunningMethodsWithResolutionErrors extends ClassLoader implements Opcodes {
45
46    @Override
47    protected Class<?> findClass(String name) throws ClassNotFoundException {
48        if (name.equals("C")) {
49            byte[] b = loadC(false);
50            return defineClass(name, b, 0, b.length);
51        } else {
52            return super.findClass(name);
53        }
54    }
55
56    private static byte[] loadC(boolean redefine) {
57        ClassWriter cw = new ClassWriter(0);
58
59        cw.visit(52, ACC_SUPER | ACC_PUBLIC, "C", null, "java/lang/Object", null);
60        {
61            MethodVisitor mv;
62
63            mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "m", "()V", null, null);
64            mv.visitCode();
65
66            // First time we run we will:
67            // 1) Cache resolution errors
68            // 2) Redefine the class / method
69            // 3) Try to read the resolution errors that were cached
70            //
71            // The redefined method will never run, throw error to be sure
72            if (redefine) {
73                createThrowRuntimeExceptionCode(mv, "The redefined method was called");
74            } else {
75                createMethodBody(mv);
76            }
77            mv.visitMaxs(3, 0);
78            mv.visitEnd();
79        }
80        cw.visitEnd();
81        return cw.toByteArray();
82    }
83
84    private static void createMethodBody(MethodVisitor mv) {
85        Label classExists = new Label();
86
87        // Cache resolution errors
88        createLoadNonExistentClassCode(mv, classExists);
89
90        // Redefine our own class and method
91        mv.visitMethodInsn(INVOKESTATIC, "RedefineRunningMethodsWithResolutionErrors", "redefine", "()V");
92
93        // Provoke the same error again to make sure the resolution error cache works
94        createLoadNonExistentClassCode(mv, classExists);
95
96        // Test passed
97        mv.visitInsn(RETURN);
98
99        mv.visitFrame(F_SAME, 0, new Object[0], 0, new Object[0]);
100        mv.visitLabel(classExists);
101
102        createThrowRuntimeExceptionCode(mv, "Loaded class that shouldn't exist (\"NonExistentClass\")");
103    }
104
105    private static void createLoadNonExistentClassCode(MethodVisitor mv, Label classExists) {
106        Label tryLoadBegin = new Label();
107        Label tryLoadEnd = new Label();
108        Label catchLoadBlock = new Label();
109        mv.visitTryCatchBlock(tryLoadBegin, tryLoadEnd, catchLoadBlock, "java/lang/NoClassDefFoundError");
110
111        // Try to load a class that does not exist to provoke resolution errors
112        mv.visitLabel(tryLoadBegin);
113        mv.visitMethodInsn(INVOKESTATIC, "NonExistentClass", "nonExistentMethod", "()V");
114        mv.visitLabel(tryLoadEnd);
115
116        // No NoClassDefFoundError means NonExistentClass existed, which shouldn't happen
117        mv.visitJumpInsn(GOTO, classExists);
118
119        mv.visitFrame(F_SAME1, 0, new Object[0], 1, new Object[] { "java/lang/NoClassDefFoundError" });
120        mv.visitLabel(catchLoadBlock);
121
122        // Ignore the expected NoClassDefFoundError
123        mv.visitInsn(POP);
124    }
125
126    private static void createThrowRuntimeExceptionCode(MethodVisitor mv, String msg) {
127        mv.visitTypeInsn(NEW, "java/lang/RuntimeException");
128        mv.visitInsn(DUP);
129        mv.visitLdcInsn(msg);
130        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/RuntimeException", "<init>", "(Ljava/lang/String;)V");
131        mv.visitInsn(ATHROW);
132    }
133
134    private static Class<?> c;
135
136    public static void redefine() throws Exception {
137        RedefineClassHelper.redefineClass(c, loadC(true));
138    }
139
140    public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InvocationTargetException {
141        c = Class.forName("C", true, new RedefineRunningMethodsWithResolutionErrors());
142        c.getMethod("m").invoke(null);
143    }
144}
145