1 /*
   2  * reserved comment block
   3  * DO NOT REMOVE OR ALTER!
   4  */
   5 /*
   6  * Licensed to the Apache Software Foundation (ASF) under one or more
   7  * contributor license agreements.  See the NOTICE file distributed with
   8  * this work for additional information regarding copyright ownership.
   9  * The ASF licenses this file to You under the Apache License, Version 2.0
  10  * (the "License"); you may not use this file except in compliance with
  11  * the License.  You may obtain a copy of the License at
  12  *
  13  *      http://www.apache.org/licenses/LICENSE-2.0
  14  *
  15  * Unless required by applicable law or agreed to in writing, software
  16  * distributed under the License is distributed on an "AS IS" BASIS,
  17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  18  * See the License for the specific language governing permissions and
  19  * limitations under the License.
  20  */
  21 
  22 package com.sun.org.apache.bcel.internal.generic;
  23 
  24 import java.io.DataOutputStream;
  25 import java.io.IOException;
  26 
  27 /**
  28  * JSR - Jump to subroutine
  29  *
  30  * @version $Id$
  31  */
  32 public class JSR extends JsrInstruction implements VariableLengthInstruction {
  33 
  34     /**
  35      * Empty constructor needed for Instruction.readInstruction.
  36      * Not to be used otherwise.
  37      */
  38     JSR() {
  39     }
  40 
  41 
  42     public JSR(final InstructionHandle target) {
  43         super(com.sun.org.apache.bcel.internal.Const.JSR, target);
  44     }
  45 
  46 
  47     /**
  48      * Dump instruction as byte code to stream out.
  49      * @param out Output stream
  50      */
  51     @Override
  52     public void dump( final DataOutputStream out ) throws IOException {
  53         super.setIndex(getTargetOffset());
  54         if (super.getOpcode() == com.sun.org.apache.bcel.internal.Const.JSR) {
  55             super.dump(out);
  56         } else { // JSR_W
  57             super.setIndex(getTargetOffset());
  58             out.writeByte(super.getOpcode());
  59             out.writeInt(super.getIndex());
  60         }
  61     }
  62 
  63 
  64     @Override
  65     protected int updatePosition( final int offset, final int max_offset ) {
  66         final int i = getTargetOffset(); // Depending on old position value
  67         setPosition(getPosition() + offset); // Position may be shifted by preceding expansions
  68         if (Math.abs(i) >= (Short.MAX_VALUE - max_offset)) { // to large for short (estimate)
  69             super.setOpcode(com.sun.org.apache.bcel.internal.Const.JSR_W);
  70             final short old_length = (short) super.getLength();
  71             super.setLength(5);
  72             return super.getLength() - old_length;
  73         }
  74         return 0;
  75     }
  76 
  77 
  78     /**
  79      * Call corresponding visitor method(s). The order is:
  80      * Call visitor methods of implemented interfaces first, then
  81      * call methods according to the class hierarchy in descending order,
  82      * i.e., the most specific visitXXX() call comes last.
  83      *
  84      * @param v Visitor object
  85      */
  86     @Override
  87     public void accept( final Visitor v ) {
  88         v.visitStackProducer(this);
  89         v.visitVariableLengthInstruction(this);
  90         v.visitBranchInstruction(this);
  91         v.visitJsrInstruction(this);
  92         v.visitJSR(this);
  93     }
  94 }