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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   *
17   */
18  package org.apache.bcel.generic;
19  
20  import java.io.DataOutputStream;
21  import java.io.IOException;
22  
23  import org.apache.bcel.util.ByteSequence;
24  
25  /**
26   * TABLESWITCH - Switch within given range of values, i.e., low..high
27   *
28   * @version $Id: TABLESWITCH.html 1021978 2017-12-09 17:38:21Z ggregory $
29   * @see SWITCH
30   */
31  public class TABLESWITCH extends Select {
32  
33      /**
34       * Empty constructor needed for Instruction.readInstruction.
35       * Not to be used otherwise.
36       */
37      TABLESWITCH() {
38      }
39  
40  
41      /**
42       * @param match sorted array of match values, match[0] must be low value,
43       * match[match_length - 1] high value
44       * @param targets where to branch for matched values
45       * @param defaultTarget default branch
46       */
47      public TABLESWITCH(final int[] match, final InstructionHandle[] targets, final InstructionHandle defaultTarget) {
48          super(org.apache.bcel.Const.TABLESWITCH, match, targets, defaultTarget);
49          /* Alignment remainder assumed 0 here, until dump time */
50          final short _length = (short) (13 + getMatch_length() * 4);
51          super.setLength(_length);
52          setFixed_length(_length);
53      }
54  
55  
56      /**
57       * Dump instruction as byte code to stream out.
58       * @param out Output stream
59       */
60      @Override
61      public void dump( final DataOutputStream out ) throws IOException {
62          super.dump(out);
63          final int _match_length = getMatch_length();
64          final int low = (_match_length > 0) ? super.getMatch(0) : 0;
65          out.writeInt(low);
66          final int high = (_match_length > 0) ? super.getMatch(_match_length - 1) : 0;
67          out.writeInt(high);
68          for (int i = 0; i < _match_length; i++) {
69              out.writeInt(setIndices(i, getTargetOffset(super.getTarget(i))));
70          }
71      }
72  
73  
74      /**
75       * Read needed data (e.g. index) from file.
76       */
77      @Override
78      protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException {
79          super.initFromFile(bytes, wide);
80          final int low = bytes.readInt();
81          final int high = bytes.readInt();
82          final int _match_length = high - low + 1;
83          setMatch_length(_match_length);
84          final short _fixed_length = (short) (13 + _match_length * 4);
85          setFixed_length(_fixed_length);
86          super.setLength((short) (_fixed_length + super.getPadding()));
87          super.setMatches(new int[_match_length]);
88          super.setIndices(new int[_match_length]);
89          super.setTargets(new InstructionHandle[_match_length]);
90          for (int i = 0; i < _match_length; i++) {
91              super.setMatch(i, low + i);
92              super.setIndices(i, bytes.readInt());
93          }
94      }
95  
96  
97      /**
98       * Call corresponding visitor method(s). The order is:
99       * Call visitor methods of implemented interfaces first, then
100      * call methods according to the class hierarchy in descending order,
101      * i.e., the most specific visitXXX() call comes last.
102      *
103      * @param v Visitor object
104      */
105     @Override
106     public void accept( final Visitor v ) {
107         v.visitVariableLengthInstruction(this);
108         v.visitStackConsumer(this);
109         v.visitBranchInstruction(this);
110         v.visitSelect(this);
111         v.visitTABLESWITCH(this);
112     }
113 }