1 /*
   2  * Copyright (c) 2013, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.jfr.internal.instrument;
  27 
  28 import java.lang.reflect.Method;
  29 import java.lang.reflect.Modifier;
  30 import java.util.List;
  31 
  32 import jdk.internal.org.objectweb.asm.ClassReader;
  33 import jdk.internal.org.objectweb.asm.ClassVisitor;
  34 import jdk.internal.org.objectweb.asm.MethodVisitor;
  35 import jdk.internal.org.objectweb.asm.Opcodes;
  36 import jdk.internal.org.objectweb.asm.Type;
  37 import jdk.internal.org.objectweb.asm.tree.ClassNode;
  38 import jdk.internal.org.objectweb.asm.tree.MethodNode;
  39 import jdk.jfr.internal.LogLevel;
  40 import jdk.jfr.internal.LogTag;
  41 import jdk.jfr.internal.Logger;
  42 
  43 @Deprecated
  44 final class JIInliner extends ClassVisitor {
  45     private final String targetClassName;
  46     private final String instrumentationClassName;
  47     private final ClassNode targetClassNode;
  48     private final List<Method> instrumentationMethods;
  49 
  50     /**
  51      * A ClassVisitor which will check all methods of the class it visits against the instrumentationMethods
  52      * list. If a method is on that list, the method will be further processed for inlining into that
  53      * method.
  54      */
  55     JIInliner(int api, ClassVisitor cv, String targetClassName, String instrumentationClassName,
  56             ClassReader targetClassReader,
  57             List<Method> instrumentationMethods) {
  58         super(api, cv);
  59         this.targetClassName = targetClassName;
  60         this.instrumentationClassName = instrumentationClassName;
  61         this.instrumentationMethods = instrumentationMethods;
  62 
  63         ClassNode cn = new ClassNode(Opcodes.ASM7);
  64         targetClassReader.accept(cn, ClassReader.EXPAND_FRAMES);
  65         this.targetClassNode = cn;
  66     }
  67 
  68     @Override
  69     public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
  70         MethodVisitor mv = super.visitMethod(access, name, desc, signature, exceptions);
  71 
  72         if (isInstrumentationMethod(name, desc)) {
  73             MethodNode methodToInline = findTargetMethodNode(name, desc);
  74             if (methodToInline == null) {
  75                 throw new IllegalArgumentException("Could not find the method to instrument in the target class");
  76             }
  77             if (Modifier.isNative(methodToInline.access)) {
  78                 throw new IllegalArgumentException("Cannot instrument native methods: " + targetClassNode.name + "." + methodToInline.name + methodToInline.desc);
  79             }
  80 
  81             Logger.log(LogTag.JFR_SYSTEM_BYTECODE, LogLevel.DEBUG, "Inliner processing method " + name + desc);
  82 
  83             JIMethodCallInliner mci = new JIMethodCallInliner(access,
  84                     desc,
  85                     mv,
  86                     methodToInline,
  87                     targetClassName,
  88                     instrumentationClassName);
  89             return mci;
  90         }
  91 
  92         return mv;
  93     }
  94 
  95     private boolean isInstrumentationMethod(String name, String desc) {
  96         for(Method m : instrumentationMethods) {
  97             if (m.getName().equals(name) && Type.getMethodDescriptor(m).equals(desc)) {
  98                 return true;
  99             }
 100         }
 101         return false;
 102     }
 103 
 104     private MethodNode findTargetMethodNode(String name, String desc) {
 105         for (MethodNode mn : targetClassNode.methods) {
 106             if (mn.desc.equals(desc) && mn.name.equals(name)) {
 107                 return mn;
 108             }
 109         }
 110         throw new IllegalArgumentException("could not find MethodNode for "
 111                 + name + desc);
 112     }
 113 }