TABLESWITCH xref

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    1   /*
    2    * Copyright  2000-2004 The Apache Software Foundation
    3    *
    4    *  Licensed under the Apache License, Version 2.0 (the "License");
    5    *  you may not use this file except in compliance with the License.
    6    *  You may obtain a copy of the License at
    7    *
    8    *      http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   *  Unless required by applicable law or agreed to in writing, software
    11   *  distributed under the License is distributed on an "AS IS" BASIS,
    12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   *  See the License for the specific language governing permissions and
    14   *  limitations under the License.
    15   *
    16   */
    17  package org.apache.bcel.generic;
    18
    19  import java.io.DataOutputStream;
    20  import java.io.IOException;
    21  import org.apache.bcel.util.ByteSequence;
    22
    23  /***
    24   * TABLESWITCH - Switch within given range of values, i.e., low..high
    25   *
    26   * @version $Id: TABLESWITCH.java 386056 2006-03-15 11:31:56Z tcurdt $
    27   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
    28   * @see SWITCH
    29   */
    30  public class TABLESWITCH extends Select {
    31
    32      /***
    33       * Empty constructor needed for the Class.newInstance() statement in
    34       * Instruction.readInstruction(). Not to be used otherwise.
    35       */
    36      TABLESWITCH() {
    37      }
    38
    39
    40      /***
    41       * @param match sorted array of match values, match[0] must be low value,
    42       * match[match_length - 1] high value
    43       * @param targets where to branch for matched values
    44       * @param defaultTarget default branch
    45       */
    46      public TABLESWITCH(int[] match, InstructionHandle[] targets, InstructionHandle defaultTarget) {
    47          super(org.apache.bcel.Constants.TABLESWITCH, match, targets, defaultTarget);
    48          length = (short) (13 + match_length * 4); /* Alignment remainder assumed
    49           * 0 here, until dump time */
    50          fixed_length = length;
    51      }
    52
    53
    54      /***
    55       * Dump instruction as byte code to stream out.
    56       * @param out Output stream
    57       */
    58      public void dump( DataOutputStream out ) throws IOException {
    59          super.dump(out);
    60          int low = (match_length > 0) ? match[0] : 0;
    61          out.writeInt(low);
    62          int high = (match_length > 0) ? match[match_length - 1] : 0;
    63          out.writeInt(high);
    64          for (int i = 0; i < match_length; i++) {
    65              out.writeInt(indices[i] = getTargetOffset(targets[i]));
    66          }
    67      }
    68
    69
    70      /***
    71       * Read needed data (e.g. index) from file.
    72       */
    73      protected void initFromFile( ByteSequence bytes, boolean wide ) throws IOException {
    74          super.initFromFile(bytes, wide);
    75          int low = bytes.readInt();
    76          int high = bytes.readInt();
    77          match_length = high - low + 1;
    78          fixed_length = (short) (13 + match_length * 4);
    79          length = (short) (fixed_length + padding);
    80          match = new int[match_length];
    81          indices = new int[match_length];
    82          targets = new InstructionHandle[match_length];
    83          for (int i = low; i <= high; i++) {
    84              match[i - low] = i;
    85          }
    86          for (int i = 0; i < match_length; i++) {
    87              indices[i] = bytes.readInt();
    88          }
    89      }
    90
    91
    92      /***
    93       * Call corresponding visitor method(s). The order is:
    94       * Call visitor methods of implemented interfaces first, then
    95       * call methods according to the class hierarchy in descending order,
    96       * i.e., the most specific visitXXX() call comes last.
    97       *
    98       * @param v Visitor object
    99       */
    100     public void accept( Visitor v ) {
    101         v.visitVariableLengthInstruction(this);
    102         v.visitStackProducer(this);
    103         v.visitBranchInstruction(this);
    104         v.visitSelect(this);
    105         v.visitTABLESWITCH(this);
    106     }
    107 }