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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  */
     18 package org.apache.bcel.generic;
     19 
     20 import org.apache.bcel.Const;
     21 import org.apache.bcel.ExceptionConst;
     22 
     23 /**
     24  * Super class for the xRETURN family of instructions.
     25  *
     26  * @version $Id$
     27  */
     28 public abstract class ReturnInstruction extends Instruction implements ExceptionThrower,
     29         TypedInstruction, StackConsumer {
     30 
     31     /**
     32      * Empty constructor needed for Instruction.readInstruction.
     33      * Not to be used otherwise.
     34      */
     35     ReturnInstruction() {
     36     }
     37 
     38 
     39     /**
     40      * @param opcode of instruction
     41      */
     42     protected ReturnInstruction(final short opcode) {
     43         super(opcode, (short) 1);
     44     }
     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     @Override
     69     public Class<?>[] getExceptions() {
     70         return new Class[] {
     71             ExceptionConst.ILLEGAL_MONITOR_STATE
     72         };
     73     }
     74 
     75 
     76     /** @return type associated with the instruction
     77      */
     78     @Override
     79     public Type getType( final ConstantPoolGen cp ) {
     80         return getType();
     81     }
     82 }
     83