1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * 
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * The contents of this file are subject to the terms of either the Universal Permissive License
   7  * v 1.0 as shown at http://oss.oracle.com/licenses/upl
   8  *
   9  * or the following license:
  10  *
  11  * Redistribution and use in source and binary forms, with or without modification, are permitted
  12  * provided that the following conditions are met:
  13  * 
  14  * 1. Redistributions of source code must retain the above copyright notice, this list of conditions
  15  * and the following disclaimer.
  16  * 
  17  * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
  18  * conditions and the following disclaimer in the documentation and/or other materials provided with
  19  * the distribution.
  20  * 
  21  * 3. Neither the name of the copyright holder nor the names of its contributors may be used to
  22  * endorse or promote products derived from this software without specific prior written permission.
  23  * 
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
  25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  26  * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
  27  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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  31  * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33 package org.openjdk.jmc.agent.jfr.impl;
  34 
  35 import java.security.ProtectionDomain;
  36 import java.util.logging.Level;
  37 
  38 import org.objectweb.asm.ClassVisitor;
  39 import org.objectweb.asm.ClassWriter;
  40 import org.objectweb.asm.MethodVisitor;
  41 import org.objectweb.asm.Opcodes;
  42 import org.openjdk.jmc.agent.Agent;
  43 import org.openjdk.jmc.agent.jfr.JFRTransformDescriptor;
  44 import org.openjdk.jmc.agent.util.TypeUtils;
  45 
  46 public class JFRClassVisitor extends ClassVisitor implements Opcodes {
  47         private final JFRTransformDescriptor transformDescriptor;
  48         private final ClassLoader definingClassLoader;
  49         private final ProtectionDomain protectionDomain;
  50 
  51         public JFRClassVisitor(ClassWriter cv, JFRTransformDescriptor descriptor, ClassLoader definingLoader,
  52                         ProtectionDomain protectionDomain) {
  53                 super(Opcodes.ASM5, cv);
  54                 this.transformDescriptor = descriptor;
  55                 this.definingClassLoader = definingLoader;
  56                 this.protectionDomain = protectionDomain;
  57         }
  58 
  59         @Override
  60         public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
  61                 MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
  62                 if (name.equals(transformDescriptor.getMethod().getName())
  63                                 && desc.equals(transformDescriptor.getMethod().getSignature())) {
  64                         return new JFRMethodAdvisor(transformDescriptor, Opcodes.ASM5, mv, access, name, desc);
  65                 }
  66                 return mv;
  67         }
  68 
  69         @Override
  70         public void visitEnd() {
  71                 try {
  72                         Class<?> c = generateEventClass();
  73                         Agent.getLogger().log(Level.FINE, "Generated " + c);
  74                 } catch (Throwable t) {
  75                         Agent.getLogger().log(Level.SEVERE, "Failed to generate event class for " + transformDescriptor.toString(), //$NON-NLS-1$
  76                                         t);
  77                 }
  78                 super.visitEnd();
  79         }
  80 
  81         private Class<?> generateEventClass() throws Exception {
  82                 byte[] eventClass = JFREventClassGenerator.generateEventClass(transformDescriptor);
  83                 return TypeUtils.getUnsafe().defineClass(transformDescriptor.getEventClassName(), eventClass, 0,
  84                                 eventClass.length, definingClassLoader, protectionDomain);
  85         }
  86 
  87 }