1 /*
   2  * Copyright (c) 2012, 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 static jdk.internal.org.objectweb.asm.Opcodes.ACONST_NULL;
  29 import static jdk.internal.org.objectweb.asm.Opcodes.ALOAD;
  30 import static jdk.internal.org.objectweb.asm.Opcodes.INVOKESTATIC;
  31 import static jdk.internal.org.objectweb.asm.Opcodes.RETURN;
  32 import jdk.internal.org.objectweb.asm.MethodVisitor;
  33 import jdk.internal.org.objectweb.asm.Opcodes;
  34 
  35 final class ConstructorWriter extends MethodVisitor {
  36 
  37     private boolean useInputParameter;
  38     private String shortClassName;
  39     private String fullClassName;
  40 
  41     ConstructorWriter(Class<?> classToChange, boolean useInputParameter) {
  42         super(Opcodes.ASM7);
  43         this.useInputParameter = useInputParameter;
  44         shortClassName = classToChange.getSimpleName();
  45         fullClassName = classToChange.getName().replace('.', '/');
  46     }
  47 
  48     @Override
  49     public void visitInsn(int opcode)
  50     {
  51         if (opcode == RETURN) {
  52             if (useInputParameter) {
  53                 useInput();
  54             } else {
  55                 noInput();
  56             }
  57         }
  58         mv.visitInsn(opcode);
  59     }
  60     @SuppressWarnings("deprecation")
  61     private void useInput()
  62     {
  63         //Load 'this' from local variable 0
  64         //Load first input parameter
  65         //Invoke ThrowableTracer.traceCLASS(this, parameter) for current class
  66         mv.visitVarInsn(ALOAD, 0);
  67         mv.visitVarInsn(ALOAD, 1);
  68         mv.visitMethodInsn(INVOKESTATIC, "jdk/jfr/internal/instrument/ThrowableTracer",
  69                 "trace" + shortClassName, "(L" + fullClassName +
  70                 ";Ljava/lang/String;)V");
  71     }
  72 
  73     @SuppressWarnings("deprecation")
  74     private void noInput()
  75     {
  76         //Load 'this' from local variable 0
  77         //Load ""
  78         //Invoke ThrowableTracer.traceCLASS(this, "") for current class
  79         mv.visitVarInsn(ALOAD, 0);
  80         mv.visitInsn(ACONST_NULL);
  81         mv.visitMethodInsn(INVOKESTATIC, "jdk/jfr/internal/instrument/ThrowableTracer",
  82                 "trace" + shortClassName, "(L" + fullClassName +
  83                 ";Ljava/lang/String;)V");
  84     }
  85 
  86     public void setMethodVisitor(MethodVisitor mv) {
  87         this.mv = mv;
  88     }
  89 }