| /* |
| * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * @test |
| * @bug 8076110 |
| * @summary Redefine running methods that have cached resolution errors |
| * @library /testlibrary |
| * @modules java.instrument |
| * java.base/jdk.internal.org.objectweb.asm |
| * @build RedefineClassHelper |
| * @run main RedefineClassHelper |
| * @run main/othervm -javaagent:redefineagent.jar RedefineRunningMethodsWithResolutionErrors |
| */ |
| |
| import jdk.internal.org.objectweb.asm.ClassWriter; |
| import jdk.internal.org.objectweb.asm.Label; |
| import jdk.internal.org.objectweb.asm.MethodVisitor; |
| import jdk.internal.org.objectweb.asm.Opcodes; |
| |
| import java.lang.reflect.InvocationTargetException; |
| |
| public class RedefineRunningMethodsWithResolutionErrors extends ClassLoader implements Opcodes { |
| |
| @Override |
| protected Class<?> findClass(String name) throws ClassNotFoundException { |
| if (name.equals("C")) { |
| byte[] b = loadC(false); |
| return defineClass(name, b, 0, b.length); |
| } else { |
| return super.findClass(name); |
| } |
| } |
| |
| private static byte[] loadC(boolean redefine) { |
| ClassWriter cw = new ClassWriter(0); |
| |
| cw.visit(52, ACC_SUPER | ACC_PUBLIC, "C", null, "java/lang/Object", null); |
| { |
| MethodVisitor mv; |
| |
| mv = cw.visitMethod(ACC_PUBLIC | ACC_STATIC, "m", "()V", null, null); |
| mv.visitCode(); |
| |
| // First time we run we will: |
| // 1) Cache resolution errors |
| // 2) Redefine the class / method |
| // 3) Try to read the resolution errors that were cached |
| // |
| // The redefined method will never run, throw error to be sure |
| if (redefine) { |
| createThrowRuntimeExceptionCode(mv, "The redefined method was called"); |
| } else { |
| createMethodBody(mv); |
| } |
| mv.visitMaxs(3, 0); |
| mv.visitEnd(); |
| } |
| cw.visitEnd(); |
| return cw.toByteArray(); |
| } |
| |
| private static void createMethodBody(MethodVisitor mv) { |
| Label classExists = new Label(); |
| |
| // Cache resolution errors |
| createLoadNonExistentClassCode(mv, classExists); |
| |
| // Redefine our own class and method |
| mv.visitMethodInsn(INVOKESTATIC, "RedefineRunningMethodsWithResolutionErrors", "redefine", "()V"); |
| |
| // Provoke the same error again to make sure the resolution error cache works |
| createLoadNonExistentClassCode(mv, classExists); |
| |
| // Test passed |
| mv.visitInsn(RETURN); |
| |
| mv.visitFrame(F_SAME, 0, new Object[0], 0, new Object[0]); |
| mv.visitLabel(classExists); |
| |
| createThrowRuntimeExceptionCode(mv, "Loaded class that shouldn't exist (\"NonExistentClass\")"); |
| } |
| |
| private static void createLoadNonExistentClassCode(MethodVisitor mv, Label classExists) { |
| Label tryLoadBegin = new Label(); |
| Label tryLoadEnd = new Label(); |
| Label catchLoadBlock = new Label(); |
| mv.visitTryCatchBlock(tryLoadBegin, tryLoadEnd, catchLoadBlock, "java/lang/NoClassDefFoundError"); |
| |
| // Try to load a class that does not exist to provoke resolution errors |
| mv.visitLabel(tryLoadBegin); |
| mv.visitMethodInsn(INVOKESTATIC, "NonExistentClass", "nonExistentMethod", "()V"); |
| mv.visitLabel(tryLoadEnd); |
| |
| // No NoClassDefFoundError means NonExistentClass existed, which shouldn't happen |
| mv.visitJumpInsn(GOTO, classExists); |
| |
| mv.visitFrame(F_SAME1, 0, new Object[0], 1, new Object[] { "java/lang/NoClassDefFoundError" }); |
| mv.visitLabel(catchLoadBlock); |
| |
| // Ignore the expected NoClassDefFoundError |
| mv.visitInsn(POP); |
| } |
| |
| private static void createThrowRuntimeExceptionCode(MethodVisitor mv, String msg) { |
| mv.visitTypeInsn(NEW, "java/lang/RuntimeException"); |
| mv.visitInsn(DUP); |
| mv.visitLdcInsn(msg); |
| mv.visitMethodInsn(INVOKESPECIAL, "java/lang/RuntimeException", "<init>", "(Ljava/lang/String;)V"); |
| mv.visitInsn(ATHROW); |
| } |
| |
| private static Class<?> c; |
| |
| public static void redefine() throws Exception { |
| RedefineClassHelper.redefineClass(c, loadC(true)); |
| } |
| |
| public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, IllegalAccessException, InvocationTargetException { |
| c = Class.forName("C", true, new RedefineRunningMethodsWithResolutionErrors()); |
| c.getMethod("m").invoke(null); |
| } |
| } |