1 /*

     2  * Copyright (c) 2019, 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 8232613

    27  * @summary Ensure Object natives stay registered after redefinition

    28  * @library /test/lib

    29  * @modules java.base/jdk.internal.misc

    30  *          java.base/jdk.internal.org.objectweb.asm

    31  *          java.compiler

    32  *          java.instrument

    33  *          jdk.jartool/sun.tools.jar

    34  * @run main RedefineObject buildagent

    35  * @run main/othervm -javaagent:redefineagent.jar RedefineObject

    36  */

    37 

    38 import static jdk.test.lib.Asserts.assertTrue;

    39 import java.io.FileNotFoundException;

    40 import java.io.PrintWriter;

    41 import java.lang.RuntimeException;

    42 import java.lang.instrument.ClassFileTransformer;

    43 import java.lang.instrument.IllegalClassFormatException;

    44 import java.lang.instrument.Instrumentation;

    45 import java.lang.instrument.UnmodifiableClassException;

    46 import java.security.ProtectionDomain;

    47 import java.util.Arrays;

    48 

    49 import jdk.internal.org.objectweb.asm.ClassReader;

    50 import jdk.internal.org.objectweb.asm.ClassVisitor;

    51 import jdk.internal.org.objectweb.asm.ClassWriter;

    52 

    53 import static jdk.internal.org.objectweb.asm.Opcodes.ASM6;

    54 import static jdk.internal.org.objectweb.asm.Opcodes.V1_8;

    55 

    56 public class RedefineObject {

    57 

    58     static Instrumentation inst;

    59 

    60     public static void premain(String agentArgs, Instrumentation inst) {

    61         RedefineObject.inst = inst;

    62     }

    63 

    64     static class Transformer implements ClassFileTransformer {

    65 

    66         public byte[] asm(ClassLoader loader, String className,

    67                           Class<?> classBeingRedefined,

    68                           ProtectionDomain protectionDomain, byte[] classfileBuffer)

    69                 throws IllegalClassFormatException {

    70             ClassWriter cw = new ClassWriter(0);

    71             // Force an older ASM to force a bytecode update

    72             ClassVisitor cv = new DummyClassVisitor(ASM6, cw) { };

    73             ClassReader cr = new ClassReader(classfileBuffer);

    74             cr.accept(cv, 0);

    75             byte[] bytes = cw.toByteArray();

    76             return bytes;

    77         }

    78 

    79         public class DummyClassVisitor extends ClassVisitor {

    80 

    81             public DummyClassVisitor(int api, ClassVisitor cv) {

    82                 super(api, cv);

    83             }

    84 

    85             public void visit(

    86                     final int version,

    87                     final int access,

    88                     final String name,

    89                     final String signature,

    90                     final String superName,

    91                     final String[] interfaces) {

    92                 // Artificially lower to JDK 8 version to force a redefine

    93                 cv.visit(V1_8, access, name, signature, superName, interfaces);

    94             }

    95         }

    96 

    97         @Override public byte[] transform(ClassLoader loader, String className,

    98                                           Class<?> classBeingRedefined,

    99                                           ProtectionDomain protectionDomain, byte[] classfileBuffer)

   100                 throws IllegalClassFormatException {

   101 

   102             if (className.contains("java/lang/Object")) {

   103                 try {

   104                     // Here we remove and re-add the dummy fields. This shuffles the constant pool

   105                     return asm(loader, className, classBeingRedefined, protectionDomain, classfileBuffer);

   106                 } catch (Throwable e) {

   107                     // The retransform native code that called this method does not propagate

   108                     // exceptions. Instead of getting an uninformative generic error, catch

   109                     // problems here and print it, then exit.

   110                     e.printStackTrace();

   111                     System.exit(1);

   112                 }

   113             }

   114             return null;

   115         }

   116     }

   117 

   118     private static void buildAgent() {

   119         try {

   120             ClassFileInstaller.main("RedefineObject");

   121         } catch (Exception e) {

   122             throw new RuntimeException("Could not write agent classfile", e);

   123         }

   124 

   125         try {

   126             PrintWriter pw = new PrintWriter("MANIFEST.MF");

   127             pw.println("Premain-Class: RedefineObject");

   128             pw.println("Agent-Class: RedefineObject");

   129             pw.println("Can-Retransform-Classes: true");

   130             pw.close();

   131         } catch (FileNotFoundException e) {

   132             throw new RuntimeException("Could not write manifest file for the agent", e);

   133         }

   134 

   135         sun.tools.jar.Main jarTool = new sun.tools.jar.Main(System.out, System.err, "jar");

   136         if (!jarTool.run(new String[] { "-cmf", "MANIFEST.MF", "redefineagent.jar", "RedefineObject.class" })) {

   137             throw new RuntimeException("Could not write the agent jar file");

   138         }

   139     }

   140 

   141     public static void main(String[] args) throws Exception {

   142 

   143         int objHash = System.identityHashCode(Object.class);

   144         System.out.println("Object hashCode: " + objHash);

   145         if (args.length == 1 && args[0].equals("buildagent")) {

   146             buildAgent();

   147             return;

   148         }

   149 

   150         if (inst == null) {

   151             throw new RuntimeException("Instrumentation object was null");

   152         }

   153 

   154         try {

   155             inst.addTransformer(new RedefineObject.Transformer(), true);

   156             inst.retransformClasses(Object.class);

   157         } catch (UnmodifiableClassException e) {

   158             throw new RuntimeException(e);

   159         }

   160 

   161         // Exercise native methods on Object after transform

   162         Object b = new Object();

   163         b.hashCode();

   164 

   165         C c = new C();

   166         assertTrue(c.hashCode() != c.clone().hashCode() || c != c.clone());

   167         assertTrue(c.clone() instanceof C);

   168         c = (C)c.clone(); // native method on new Object

   169     }

   170 

   171     private static class C implements Cloneable {

   172         @Override

   173         protected Object clone() throws CloneNotSupportedException {

   174             return super.clone();

   175         }

   176     }

   177 }