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