[jboss-cvs] javassist/src/main/javassist/convert ...

[Shigeru Chiba]

  User: chiba   
  Date: 08/09/08 06:56:50

  Added:       src/main/javassist/convert  TransformNewClass.java
  Log:
  implemented CodeConverter.replaceNew(CtClass,CtClass)
  
  Revision  Changes    Path
  1.1      date: 2008/09/08 10:56:50;  author: chiba;  state: Exp;javassist/src/main/javassist/convert/TransformNewClass.java
  
  Index: TransformNewClass.java
  ===================================================================
  /*
   * Javassist, a Java-bytecode translator toolkit.
   * Copyright (C) 1999-2007 Shigeru Chiba. All Rights Reserved.
   *
   * The contents of this file are subject to the Mozilla Public License Version
   * 1.1 (the "License"); you may not use this file except in compliance with
   * the License.  Alternatively, the contents of this file may be used under
   * the terms of the GNU Lesser General Public License Version 2.1 or later.
   *
   * Software distributed under the License is distributed on an "AS IS" basis,
   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
   * for the specific language governing rights and limitations under the
   * License.
   */
  
  package javassist.convert;
  
  import javassist.bytecode.*;
  import javassist.CtClass;
  import javassist.CannotCompileException;
  
  final public class TransformNewClass extends Transformer {
      private int nested;
      private String classname, newClassName;
      private int newClassIndex, newMethodNTIndex, newMethodIndex;
  
      public TransformNewClass(Transformer next,
                               String classname, String newClassName) {
          super(next);
          this.classname = classname;
          this.newClassName = newClassName;
      }
  
      public void initialize(ConstPool cp, CodeAttribute attr) {
          nested = 0;
          newClassIndex = newMethodNTIndex = newMethodIndex = 0;
      }
  
      /**
       * Modifies a sequence of
       *    NEW classname
       *    DUP
       *    ...
       *    INVOKESPECIAL classname:method
       */
      public int transform(CtClass clazz, int pos, CodeIterator iterator,
                           ConstPool cp) throws CannotCompileException
      {
          int index;
          int c = iterator.byteAt(pos);
          if (c == NEW) {
              index = iterator.u16bitAt(pos + 1);
              if (cp.getClassInfo(index).equals(classname)) {
                  if (iterator.byteAt(pos + 3) != DUP)
                      throw new CannotCompileException(
                                  "NEW followed by no DUP was found");
  
                  if (newClassIndex == 0)
                      newClassIndex = cp.addClassInfo(newClassName);
  
                  iterator.write16bit(newClassIndex, pos + 1);
                  ++nested;
              }
          }
          else if (c == INVOKESPECIAL) {
              index = iterator.u16bitAt(pos + 1);
              int typedesc = cp.isConstructor(classname, index);
              if (typedesc != 0 && nested > 0) {
                  int nt = cp.getMethodrefNameAndType(index);
                  if (newMethodNTIndex != nt) {
                      newMethodNTIndex = nt;
                      newMethodIndex = cp.addMethodrefInfo(newClassIndex, nt);
                  }
  
                  iterator.write16bit(newMethodIndex, pos + 1);
                  --nested;
              }
          }
  
          return pos;
      }
  }