alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

Java example source code file (BytecodeDisassembler.java)

This example Java source code file (BytecodeDisassembler.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

bytecode, bytecodedisassembler, bytecodestream, class, constructor, exception, hashmap, integer, map, method, object, reflection, util

The BytecodeDisassembler.java Java example source code

/*
 * Copyright (c) 2002, 2012, 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.
 *
 */

package sun.jvm.hotspot.interpreter;

import java.util.*;
import java.lang.reflect.Constructor;
import sun.jvm.hotspot.oops.*;
import sun.jvm.hotspot.utilities.*;

public class BytecodeDisassembler {
   private Method method;

   private static Map bytecode2Class = new HashMap(); // Map<int, Class>

   private static void addBytecodeClass(int bytecode, Class clazz) {
      bytecode2Class.put(new Integer(bytecode), clazz);
   }

   private static Class getBytecodeClass(int bytecode) {
      return (Class) bytecode2Class.get(new Integer(bytecode));
   }

   static {
      addBytecodeClass(Bytecodes._anewarray, BytecodeANewArray.class);
      addBytecodeClass(Bytecodes._bipush, BytecodeBipush.class);
      addBytecodeClass(Bytecodes._checkcast, BytecodeCheckCast.class);
      addBytecodeClass(Bytecodes._getfield, BytecodeGetField.class);
      addBytecodeClass(Bytecodes._getstatic, BytecodeGetStatic.class);
      addBytecodeClass(Bytecodes._goto, BytecodeGoto.class);
      addBytecodeClass(Bytecodes._goto_w, BytecodeGotoW.class);
      addBytecodeClass(Bytecodes._ifeq, BytecodeIf.class);
      addBytecodeClass(Bytecodes._ifne, BytecodeIf.class);
      addBytecodeClass(Bytecodes._iflt, BytecodeIf.class);
      addBytecodeClass(Bytecodes._ifge, BytecodeIf.class);
      addBytecodeClass(Bytecodes._ifgt, BytecodeIf.class);
      addBytecodeClass(Bytecodes._ifle, BytecodeIf.class);
      addBytecodeClass(Bytecodes._if_icmpeq, BytecodeIf.class);
      addBytecodeClass(Bytecodes._if_icmpne, BytecodeIf.class);
      addBytecodeClass(Bytecodes._if_icmplt, BytecodeIf.class);
      addBytecodeClass(Bytecodes._if_icmpge, BytecodeIf.class);
      addBytecodeClass(Bytecodes._if_icmpgt, BytecodeIf.class);
      addBytecodeClass(Bytecodes._if_icmple, BytecodeIf.class);
      addBytecodeClass(Bytecodes._if_acmpeq, BytecodeIf.class);
      addBytecodeClass(Bytecodes._if_acmpne, BytecodeIf.class);
      addBytecodeClass(Bytecodes._ifnull, BytecodeIf.class);
      addBytecodeClass(Bytecodes._ifnonnull, BytecodeIf.class);
      addBytecodeClass(Bytecodes._iinc, BytecodeIinc.class);
      addBytecodeClass(Bytecodes._instanceof, BytecodeInstanceOf.class);
      addBytecodeClass(Bytecodes._invokevirtual, BytecodeInvoke.class);
      addBytecodeClass(Bytecodes._invokestatic, BytecodeInvoke.class);
      addBytecodeClass(Bytecodes._invokespecial, BytecodeInvoke.class);
      addBytecodeClass(Bytecodes._invokeinterface, BytecodeInvoke.class);
      addBytecodeClass(Bytecodes._invokedynamic, BytecodeInvoke.class);
      addBytecodeClass(Bytecodes._jsr, BytecodeJsr.class);
      addBytecodeClass(Bytecodes._jsr_w, BytecodeJsrW.class);
      addBytecodeClass(Bytecodes._iload, BytecodeLoad.class);
      addBytecodeClass(Bytecodes._lload, BytecodeLoad.class);
      addBytecodeClass(Bytecodes._fload, BytecodeLoad.class);
      addBytecodeClass(Bytecodes._dload, BytecodeLoad.class);
      addBytecodeClass(Bytecodes._aload, BytecodeLoad.class);
      addBytecodeClass(Bytecodes._ldc,   BytecodeLoadConstant.class);
      addBytecodeClass(Bytecodes._ldc_w, BytecodeLoadConstant.class);
      addBytecodeClass(Bytecodes._ldc2_w, BytecodeLoadConstant.class);
      addBytecodeClass(Bytecodes._lookupswitch, BytecodeLookupswitch.class);
      addBytecodeClass(Bytecodes._multianewarray, BytecodeMultiANewArray.class);
      addBytecodeClass(Bytecodes._new, BytecodeNew.class);
      addBytecodeClass(Bytecodes._newarray, BytecodeNewArray.class);
      addBytecodeClass(Bytecodes._putfield, BytecodePutField.class);
      addBytecodeClass(Bytecodes._putstatic, BytecodePutStatic.class);
      addBytecodeClass(Bytecodes._ret, BytecodeRet.class);
      addBytecodeClass(Bytecodes._sipush, BytecodeSipush.class);
      addBytecodeClass(Bytecodes._istore, BytecodeStore.class);
      addBytecodeClass(Bytecodes._lstore, BytecodeStore.class);
      addBytecodeClass(Bytecodes._fstore, BytecodeStore.class);
      addBytecodeClass(Bytecodes._dstore, BytecodeStore.class);
      addBytecodeClass(Bytecodes._astore, BytecodeStore.class);
      addBytecodeClass(Bytecodes._tableswitch, BytecodeTableswitch.class);
   }

   public BytecodeDisassembler(Method method) {
      this.method = method;
   }

   public Method getMethod() {
      return method;
   }

   public void decode(BytecodeVisitor visitor) {
      visitor.prologue(method);

      BytecodeStream stream = new BytecodeStream(method);
      int javacode = Bytecodes._illegal;
      while ( (javacode = stream.next()) != Bytecodes._illegal) {
         // look for special Bytecode class
         int bci = stream.bci();
         int hotspotcode = method.getBytecodeOrBPAt(bci);
         Class clazz = getBytecodeClass(javacode);
         if (clazz == null) {
            // check for fast_(i|a)_access_0
            clazz = getBytecodeClass(hotspotcode);
            if (clazz == null) {
               // use generic bytecode class
               clazz = Bytecode.class;
            }
         }

         // All bytecode classes must have a constructor with signature
         // (Lsun/jvm/hotspot/oops/Method;I)V

         Constructor cstr = null;
         try {
            cstr = clazz.getDeclaredConstructor(new Class[] { Method.class, Integer.TYPE });
         } catch(NoSuchMethodException nomethod) {
            if (Assert.ASSERTS_ENABLED) {
               Assert.that(false, "Bytecode class without proper constructor!");
            }
         }

         Bytecode bytecodeObj = null;
         try {
            bytecodeObj = (Bytecode)cstr.newInstance(new Object[] { method, new Integer(bci) });
         } catch (Exception exp) {
            if (Assert.ASSERTS_ENABLED) {
               Assert.that(false, "Bytecode instance of class "
                           + clazz.getName() + " can not be created!");
            }
         }

         if (stream.isWide()) {
            visitor.visit(new Bytecode(method, bci - 1));
         }

         try {
            visitor.visit(bytecodeObj);
         } catch(ClassCastException castfail) {
             castfail.printStackTrace();
             System.err.println(method.getAddress() + " " + bci);
         }
      }

      visitor.epilogue();
   }
}

Other Java examples (source code examples)

Here is a short list of links related to this Java BytecodeDisassembler.java source code file:

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.