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 package org.apache.bcel.generic;
18
19 import java.io.DataOutputStream;
20 import java.io.IOException;
21
22 import org.apache.bcel.util.ByteSequence;
23
24 /**
25 * TABLESWITCH - Switch within given range of values, i.e., low..high
26 *
27 * @see SWITCH
28 */
29 public class TABLESWITCH extends Select {
30
31 /**
32 * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
33 */
34 TABLESWITCH() {
35 }
36
37 /**
38 * @param match sorted array of match values, match[0] must be low value, match[match_length - 1] high value
39 * @param targets where to branch for matched values
40 * @param defaultTarget default branch
41 */
42 public TABLESWITCH(final int[] match, final InstructionHandle[] targets, final InstructionHandle defaultTarget) {
43 super(org.apache.bcel.Const.TABLESWITCH, match, targets, defaultTarget);
44 /* Alignment remainder assumed 0 here, until dump time */
45 final short length = (short) (13 + getMatchLength() * 4);
46 super.setLength(length);
47 setFixedLength(length);
48 }
49
50 /**
51 * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
52 * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
53 *
54 * @param v Visitor object
55 */
56 @Override
57 public void accept(final Visitor v) {
58 v.visitVariableLengthInstruction(this);
59 v.visitStackConsumer(this);
60 v.visitBranchInstruction(this);
61 v.visitSelect(this);
62 v.visitTABLESWITCH(this);
63 }
64
65 /**
66 * Dump instruction as byte code to stream out.
67 *
68 * @param out Output stream
69 */
70 @Override
71 public void dump(final DataOutputStream out) throws IOException {
72 super.dump(out);
73 final int matchLength = getMatchLength();
74 final int low = matchLength > 0 ? super.getMatch(0) : 0;
75 out.writeInt(low);
76 final int high = matchLength > 0 ? super.getMatch(matchLength - 1) : 0;
77 out.writeInt(high);
78 for (int i = 0; i < matchLength; i++) {
79 out.writeInt(setIndices(i, getTargetOffset(super.getTarget(i))));
80 }
81 }
82
83 /**
84 * Read needed data (e.g. index) from file.
85 */
86 @Override
87 protected void initFromFile(final ByteSequence bytes, final boolean wide) throws IOException {
88 super.initFromFile(bytes, wide);
89 final int low = bytes.readInt();
90 final int high = bytes.readInt();
91 final int matchLength = high - low + 1;
92 setMatchLength(matchLength);
93 final short fixedLength = (short) (13 + matchLength * 4);
94 setFixedLength(fixedLength);
95 super.setLength((short) (fixedLength + super.getPadding()));
96 super.setMatches(new int[matchLength]);
97 super.setIndices(new int[matchLength]);
98 super.setTargets(new InstructionHandle[matchLength]);
99 for (int i = 0; i < matchLength; i++) {
100 super.setMatch(i, low + i);
101 super.setIndices(i, bytes.readInt());
102 }
103 }
104 }