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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 org.apache.bcel.Constants;
    20  import org.apache.bcel.ExceptionConstants;
    21
    22  /***
    23   * Super class for the xRETURN family of instructions.
    24   *
    25   * @version $Id: ReturnInstruction.java 386056 2006-03-15 11:31:56Z tcurdt $
    26   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
    27   */
    28  public abstract class ReturnInstruction extends Instruction implements ExceptionThrower,
    29          TypedInstruction, StackConsumer {
    30
    31      /***
    32       * Empty constructor needed for the Class.newInstance() statement in
    33       * Instruction.readInstruction(). Not to be used otherwise.
    34       */
    35      ReturnInstruction() {
    36      }
    37
    38
    39      /***
    40       * @param opcode of instruction
    41       */
    42      protected ReturnInstruction(short opcode) {
    43          super(opcode, (short) 1);
    44      }
    45
    46
    47      public Type getType() {
    48          switch (opcode) {
    49              case Constants.IRETURN:
    50                  return Type.INT;
    51              case Constants.LRETURN:
    52                  return Type.LONG;
    53              case Constants.FRETURN:
    54                  return Type.FLOAT;
    55              case Constants.DRETURN:
    56                  return Type.DOUBLE;
    57              case Constants.ARETURN:
    58                  return Type.OBJECT;
    59              case Constants.RETURN:
    60                  return Type.VOID;
    61              default: // Never reached
    62                  throw new ClassGenException("Unknown type " + opcode);
    63          }
    64      }
    65
    66
    67      public Class[] getExceptions() {
    68          return new Class[] {
    69              ExceptionConstants.ILLEGAL_MONITOR_STATE
    70          };
    71      }
    72
    73
    74      /*** @return type associated with the instruction
    75       */
    76      public Type getType( ConstantPoolGen cp ) {
    77          return getType();
    78      }
    79  }