1 /*
   2  * reserved comment block
   3  * DO NOT REMOVE OR ALTER!
   4  */
   5 package com.sun.org.apache.bcel.internal.generic;
   6 
   7 /* ====================================================================
   8  * The Apache Software License, Version 1.1
   9  *
  10  * Copyright (c) 2001 The Apache Software Foundation.  All rights
  11  * reserved.
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  *
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  *
  20  * 2. Redistributions in binary form must reproduce the above copyright
  21  *    notice, this list of conditions and the following disclaimer in
  22  *    the documentation and/or other materials provided with the
  23  *    distribution.
  24  *
  25  * 3. The end-user documentation included with the redistribution,
  26  *    if any, must include the following acknowledgment:
  27  *       "This product includes software developed by the
  28  *        Apache Software Foundation (http://www.apache.org/)."
  29  *    Alternately, this acknowledgment may appear in the software itself,
  30  *    if and wherever such third-party acknowledgments normally appear.
  31  *
  32  * 4. The names "Apache" and "Apache Software Foundation" and
  33  *    "Apache BCEL" must not be used to endorse or promote products
  34  *    derived from this software without prior written permission. For
  35  *    written permission, please contact apache@apache.org.
  36  *
  37  * 5. Products derived from this software may not be called "Apache",
  38  *    "Apache BCEL", nor may "Apache" appear in their name, without
  39  *    prior written permission of the Apache Software Foundation.
  40  *
  41  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
  42  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  43  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  44  * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
  45  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  46  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  47  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  48  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  49  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  50  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  51  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  52  * SUCH DAMAGE.
  53  * ====================================================================
  54  *
  55  * This software consists of voluntary contributions made by many
  56  * individuals on behalf of the Apache Software Foundation.  For more
  57  * information on the Apache Software Foundation, please see
  58  * <http://www.apache.org/>.
  59  */
  60 
  61 import com.sun.org.apache.bcel.internal.Constants;
  62 import com.sun.org.apache.bcel.internal.ExceptionConstants;
  63 
  64 /**
  65  * GETFIELD - Fetch field from object
  66  * <PRE>Stack: ..., objectref -&gt; ..., value</PRE>
  67  * OR
  68  * <PRE>Stack: ..., objectref -&gt; ..., value.word1, value.word2</PRE>
  69  *
  70  * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
  71  */
  72 public class GETFIELD extends FieldInstruction
  73   implements ExceptionThrower, StackConsumer, StackProducer {
  74   /**
  75    * Empty constructor needed for the Class.newInstance() statement in
  76    * Instruction.readInstruction(). Not to be used otherwise.
  77    */
  78   GETFIELD() {}
  79 
  80   public GETFIELD(int index) {
  81     super(Constants.GETFIELD, index);
  82   }
  83 
  84   public int produceStack(ConstantPoolGen cpg) { return getFieldSize(cpg); }
  85 
  86   public Class[] getExceptions() {
  87     Class[] cs = new Class[2 + ExceptionConstants.EXCS_FIELD_AND_METHOD_RESOLUTION.length];
  88 
  89     System.arraycopy(ExceptionConstants.EXCS_FIELD_AND_METHOD_RESOLUTION, 0,
  90                      cs, 0, ExceptionConstants.EXCS_FIELD_AND_METHOD_RESOLUTION.length);
  91 
  92     cs[ExceptionConstants.EXCS_FIELD_AND_METHOD_RESOLUTION.length+1] =
  93       ExceptionConstants.INCOMPATIBLE_CLASS_CHANGE_ERROR;
  94     cs[ExceptionConstants.EXCS_FIELD_AND_METHOD_RESOLUTION.length] =
  95       ExceptionConstants.NULL_POINTER_EXCEPTION;
  96 
  97     return cs;
  98   }
  99 
 100 
 101   /**
 102    * Call corresponding visitor method(s). The order is:
 103    * Call visitor methods of implemented interfaces first, then
 104    * call methods according to the class hierarchy in descending order,
 105    * i.e., the most specific visitXXX() call comes last.
 106    *
 107    * @param v Visitor object
 108    */
 109   public void accept(Visitor v) {
 110     v.visitExceptionThrower(this);
 111     v.visitStackConsumer(this);
 112     v.visitStackProducer(this);
 113     v.visitTypedInstruction(this);
 114     v.visitLoadClass(this);
 115     v.visitCPInstruction(this);
 116     v.visitFieldOrMethod(this);
 117     v.visitFieldInstruction(this);
 118     v.visitGETFIELD(this);
 119   }
 120 }