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