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 * Constructs a ReturnInstruction.
37 *
38 * @param opcode of instruction.
39 */
40 protected ReturnInstruction(final short opcode) {
41 super(opcode, (short) 1);
42 }
43
44 @Override
45 public Class<?>[] getExceptions() {
46 return new Class[] {ExceptionConst.ILLEGAL_MONITOR_STATE};
47 }
48
49 /**
50 * Gets the type of the returned value.
51 *
52 * @return The type.
53 */
54 public Type getType() {
55 final short opcode = super.getOpcode();
56 switch (opcode) {
57 case Const.IRETURN:
58 return Type.INT;
59 case Const.LRETURN:
60 return Type.LONG;
61 case Const.FRETURN:
62 return Type.FLOAT;
63 case Const.DRETURN:
64 return Type.DOUBLE;
65 case Const.ARETURN:
66 return Type.OBJECT;
67 case Const.RETURN:
68 return Type.VOID;
69 default: // Never reached
70 throw new ClassGenException("Unknown type " + opcode);
71 }
72 }
73
74 /**
75 * @return type associated with the instruction.
76 */
77 @Override
78 public Type getType(final ConstantPoolGen cp) {
79 return getType();
80 }
81 }