001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 *
017 */
018 package org.apache.bcel.generic;
019
020 import java.io.DataOutputStream;
021 import java.io.IOException;
022 import org.apache.bcel.util.ByteSequence;
023
024 /**
025 * TABLESWITCH - Switch within given range of values, i.e., low..high
026 *
027 * @version $Id: TABLESWITCH.java 1152072 2011-07-29 01:54:05Z dbrosius $
028 * @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
029 * @see SWITCH
030 */
031 public class TABLESWITCH extends Select {
032
033 private static final long serialVersionUID = -1178229029789923698L;
034
035
036 /**
037 * Empty constructor needed for the Class.newInstance() statement in
038 * Instruction.readInstruction(). Not to be used otherwise.
039 */
040 TABLESWITCH() {
041 }
042
043
044 /**
045 * @param match sorted array of match values, match[0] must be low value,
046 * match[match_length - 1] high value
047 * @param targets where to branch for matched values
048 * @param defaultTarget default branch
049 */
050 public TABLESWITCH(int[] match, InstructionHandle[] targets, InstructionHandle defaultTarget) {
051 super(org.apache.bcel.Constants.TABLESWITCH, match, targets, defaultTarget);
052 length = (short) (13 + match_length * 4); /* Alignment remainder assumed
053 * 0 here, until dump time */
054 fixed_length = length;
055 }
056
057
058 /**
059 * Dump instruction as byte code to stream out.
060 * @param out Output stream
061 */
062 @Override
063 public void dump( DataOutputStream out ) throws IOException {
064 super.dump(out);
065 int low = (match_length > 0) ? match[0] : 0;
066 out.writeInt(low);
067 int high = (match_length > 0) ? match[match_length - 1] : 0;
068 out.writeInt(high);
069 for (int i = 0; i < match_length; i++) {
070 out.writeInt(indices[i] = getTargetOffset(targets[i]));
071 }
072 }
073
074
075 /**
076 * Read needed data (e.g. index) from file.
077 */
078 @Override
079 protected void initFromFile( ByteSequence bytes, boolean wide ) throws IOException {
080 super.initFromFile(bytes, wide);
081 int low = bytes.readInt();
082 int high = bytes.readInt();
083 match_length = high - low + 1;
084 fixed_length = (short) (13 + match_length * 4);
085 length = (short) (fixed_length + padding);
086 match = new int[match_length];
087 indices = new int[match_length];
088 targets = new InstructionHandle[match_length];
089 for (int i = 0; i < match_length; i++) {
090 match[i] = low + i;
091 indices[i] = bytes.readInt();
092 }
093 }
094
095
096 /**
097 * Call corresponding visitor method(s). The order is:
098 * Call visitor methods of implemented interfaces first, then
099 * call methods according to the class hierarchy in descending order,
100 * i.e., the most specific visitXXX() call comes last.
101 *
102 * @param v Visitor object
103 */
104 @Override
105 public void accept( Visitor v ) {
106 v.visitVariableLengthInstruction(this);
107 v.visitStackConsumer(this);
108 v.visitBranchInstruction(this);
109 v.visitSelect(this);
110 v.visitTABLESWITCH(this);
111 }
112 }