    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 *
    017 */
    018package org.apache.bcel.generic;
    019
    020import org.apache.bcel.Const;
    021import org.apache.bcel.ExceptionConst;
    022
    023/**
    024 * Super class for the xRETURN family of instructions.
    025 *
    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}