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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  import com.sun.org.apache.bcel.internal.util.ByteSequence;
62  
63  /**
64   * TABLESWITCH - Switch within given range of values, i.e., low..high
65   *
66   * @author  <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
67   * @see SWITCH
68   */
69  public class TABLESWITCH extends Select {
70    /**
71     * Empty constructor needed for the Class.newInstance() statement in
72     * Instruction.readInstruction(). Not to be used otherwise.
73     */
74    TABLESWITCH() {}
75  
76    /**
77     * @param match sorted array of match values, match[0] must be low value,
78     * match[match_length - 1] high value
79     * @param targets where to branch for matched values
80     * @param target default branch
81     */
82    public TABLESWITCH(int[] match, InstructionHandle[] targets,
83                       InstructionHandle target) {
84      super(com.sun.org.apache.bcel.internal.Constants.TABLESWITCH, match, targets, target);
85  
86      length = (short)(13 + match_length * 4); /* Alignment remainder assumed
87                                                * 0 here, until dump time */
88      fixed_length = length;
89    }
90  
91    /**
92     * Dump instruction as byte code to stream out.
93     * @param out Output stream
94     */
95    public void dump(DataOutputStream out) throws IOException {
96      super.dump(out);
97  
98      int low = (match_length > 0)? match[0] : 0;
99      out.writeInt(low);
100 
101     int high = (match_length > 0)? match[match_length - 1] : 0;
102     out.writeInt(high);
103 
104     for(int i=0; i < match_length; i++)     // jump offsets
105       out.writeInt(indices[i] = getTargetOffset(targets[i]));
106   }
107 
108   /**
109    * Read needed data (e.g. index) from file.
110    */
111   protected void initFromFile(ByteSequence bytes, boolean wide) throws IOException
112   {
113     super.initFromFile(bytes, wide);
114 
115     int low    = bytes.readInt();
116     int high   = bytes.readInt();
117 
118     match_length = high - low + 1;
119     fixed_length = (short)(13 + match_length * 4);
120     length       = (short)(fixed_length + padding);
121 
122     match   = new int[match_length];
123     indices = new int[match_length];
124     targets = new InstructionHandle[match_length];
125 
126     for(int i=low; i <= high; i++)
127       match[i - low] = i;
128 
129     for(int i=0; i < match_length; i++) {
130       indices[i] = bytes.readInt();
131     }
132   }
133 
134 
135   /**
136    * Call corresponding visitor method(s). The order is:
137    * Call visitor methods of implemented interfaces first, then
138    * call methods according to the class hierarchy in descending order,
139    * i.e., the most specific visitXXX() call comes last.
140    *
141    * @param v Visitor object
142    */
143   public void accept(Visitor v) {
144     v.visitVariableLengthInstruction(this);
145     v.visitStackProducer(this);
146     v.visitBranchInstruction(this);
147     v.visitSelect(this);
148     v.visitTABLESWITCH(this);
149   }
150 }