001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.bcel.generic;
020
021import org.apache.bcel.Const;
022import org.apache.bcel.ExceptionConst;
023
024/**
025 * Super class for the xRETURN family of instructions.
026 */
027public abstract class ReturnInstruction extends Instruction implements ExceptionThrower, TypedInstruction, StackConsumer {
028
029    /**
030     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
031     */
032    ReturnInstruction() {
033    }
034
035    /**
036     * @param opcode of instruction
037     */
038    protected ReturnInstruction(final short opcode) {
039        super(opcode, (short) 1);
040    }
041
042    @Override
043    public Class<?>[] getExceptions() {
044        return new Class[] {ExceptionConst.ILLEGAL_MONITOR_STATE};
045    }
046
047    public Type getType() {
048        final short opcode = super.getOpcode();
049        switch (opcode) {
050        case Const.IRETURN:
051            return Type.INT;
052        case Const.LRETURN:
053            return Type.LONG;
054        case Const.FRETURN:
055            return Type.FLOAT;
056        case Const.DRETURN:
057            return Type.DOUBLE;
058        case Const.ARETURN:
059            return Type.OBJECT;
060        case Const.RETURN:
061            return Type.VOID;
062        default: // Never reached
063            throw new ClassGenException("Unknown type " + opcode);
064        }
065    }
066
067    /**
068     * @return type associated with the instruction
069     */
070    @Override
071    public Type getType(final ConstantPoolGen cp) {
072        return getType();
073    }
074}