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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   https://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.bcel.generic;
20  
21  import org.apache.bcel.Const;
22  import org.apache.bcel.ExceptionConst;
23  
24  /**
25   * Super class for the xRETURN family of instructions.
26   */
27  public abstract class ReturnInstruction extends Instruction implements ExceptionThrower, TypedInstruction, StackConsumer {
28  
29      /**
30       * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
31       */
32      ReturnInstruction() {
33      }
34  
35      /**
36       * @param opcode of instruction
37       */
38      protected ReturnInstruction(final short opcode) {
39          super(opcode, (short) 1);
40      }
41  
42      @Override
43      public Class<?>[] getExceptions() {
44          return new Class[] {ExceptionConst.ILLEGAL_MONITOR_STATE};
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       * @return type associated with the instruction
69       */
70      @Override
71      public Type getType(final ConstantPoolGen cp) {
72          return getType();
73      }
74  }