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 import java.io.*;
61 
62 /**
63  * JSR - Jump to subroutine
64  *
65  * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
66  */
67 public class JSR extends JsrInstruction implements VariableLengthInstruction {
68   /**
69    * Empty constructor needed for the Class.newInstance() statement in
70    * Instruction.readInstruction(). Not to be used otherwise.
71    */
JSR()72   JSR() {}
73 
JSR(InstructionHandle target)74   public JSR(InstructionHandle target) {
75     super(com.sun.org.apache.bcel.internal.Constants.JSR, target);
76   }
77 
78   /**
79    * Dump instruction as byte code to stream out.
80    * @param out Output stream
81    */
dump(DataOutputStream out)82   public void dump(DataOutputStream out) throws IOException {
83     index = getTargetOffset();
84     if(opcode == com.sun.org.apache.bcel.internal.Constants.JSR)
85       super.dump(out);
86     else { // JSR_W
87       index = getTargetOffset();
88       out.writeByte(opcode);
89       out.writeInt(index);
90     }
91   }
92 
updatePosition(int offset, int max_offset)93   protected int updatePosition(int offset, int max_offset) {
94     int i = getTargetOffset(); // Depending on old position value
95 
96     position += offset; // Position may be shifted by preceding expansions
97 
98     if(Math.abs(i) >= (32767 - max_offset)) { // to large for short (estimate)
99       opcode  = com.sun.org.apache.bcel.internal.Constants.JSR_W;
100       length = 5;
101       return 2; // 5 - 3
102     }
103 
104     return 0;
105   }
106 
107   /**
108    * Call corresponding visitor method(s). The order is:
109    * Call visitor methods of implemented interfaces first, then
110    * call methods according to the class hierarchy in descending order,
111    * i.e., the most specific visitXXX() call comes last.
112    *
113    * @param v Visitor object
114    */
accept(Visitor v)115   public void accept(Visitor v) {
116     v.visitStackProducer(this);
117     v.visitVariableLengthInstruction(this);
118     v.visitBranchInstruction(this);
119     v.visitJsrInstruction(this);
120     v.visitJSR(this);
121   }
122 }
123