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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 $Id$
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      */
TABLESWITCH()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      */
TABLESWITCH(final int[] match, final InstructionHandle[] targets, final InstructionHandle defaultTarget)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
dump( final DataOutputStream out )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
initFromFile( final ByteSequence bytes, final boolean wide )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
accept( final Visitor v )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 }
114