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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   */
18  package org.apache.bcel.generic;
19  
20  import org.apache.bcel.Const;
21  import org.apache.bcel.ExceptionConst;
22  
23  /**
24   * Super class for the xRETURN family of instructions.
25   *
26   * @version $Id: ReturnInstruction.html 1021978 2017-12-09 17:38:21Z ggregory $
27   */
28  public abstract class ReturnInstruction extends Instruction implements ExceptionThrower,
29          TypedInstruction, StackConsumer {
30  
31      /**
32       * Empty constructor needed for Instruction.readInstruction.
33       * Not to be used otherwise.
34       */
35      ReturnInstruction() {
36      }
37  
38  
39      /**
40       * @param opcode of instruction
41       */
42      protected ReturnInstruction(final short opcode) {
43          super(opcode, (short) 1);
44      }
45  
46  
47      public Type getType() {
48          final short _opcode = super.getOpcode();
49          switch (_opcode) {
50              case Const.IRETURN:
51                  return Type.INT;
52              case Const.LRETURN:
53                  return Type.LONG;
54              case Const.FRETURN:
55                  return Type.FLOAT;
56              case Const.DRETURN:
57                  return Type.DOUBLE;
58              case Const.ARETURN:
59                  return Type.OBJECT;
60              case Const.RETURN:
61                  return Type.VOID;
62              default: // Never reached
63                  throw new ClassGenException("Unknown type " + _opcode);
64          }
65      }
66  
67  
68      @Override
69      public Class<?>[] getExceptions() {
70          return new Class[] {
71              ExceptionConst.ILLEGAL_MONITOR_STATE
72          };
73      }
74  
75  
76      /** @return type associated with the instruction
77       */
78      @Override
79      public Type getType( final ConstantPoolGen cp ) {
80          return getType();
81      }
82  }