1 /*
   2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
   3  */
   4 /*
   5  * Licensed to the Apache Software Foundation (ASF) under one or more
   6  * contributor license agreements.  See the NOTICE file distributed with
   7  * this work for additional information regarding copyright ownership.
   8  * The ASF licenses this file to You under the Apache License, Version 2.0
   9  * (the "License"); you may not use this file except in compliance with
  10  * the License.  You may obtain a copy of the License at
  11  *
  12  *      http://www.apache.org/licenses/LICENSE-2.0
  13  *
  14  * Unless required by applicable law or agreed to in writing, software
  15  * distributed under the License is distributed on an "AS IS" BASIS,
  16  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  17  * See the License for the specific language governing permissions and
  18  * limitations under the License.
  19  */
  20 
  21 package com.sun.org.apache.bcel.internal.generic;
  22 
  23 import com.sun.org.apache.bcel.internal.Const;
  24 import com.sun.org.apache.bcel.internal.ExceptionConst;
  25 
  26 /**
  27  * Super class for the xRETURN family of instructions.
  28  *
  29  * @version $Id: ReturnInstruction.java 1747278 2016-06-07 17:28:43Z britter $
  30  * @LastModified: Oct 2017
  31  */
  32 public abstract class ReturnInstruction extends Instruction implements ExceptionThrower,
  33         TypedInstruction, StackConsumer {
  34 
  35     /**
  36      * Empty constructor needed for the Class.newInstance() statement in
  37      * Instruction.readInstruction(). Not to be used otherwise.
  38      */
  39     ReturnInstruction() {
  40     }
  41 
  42 
  43     /**
  44      * @param opcode of instruction
  45      */
  46     protected ReturnInstruction(final short opcode) {
  47         super(opcode, (short) 1);
  48     }
  49 
  50 
  51     public Type getType() {
  52         final short _opcode = super.getOpcode();
  53         switch (_opcode) {
  54             case Const.IRETURN:
  55                 return Type.INT;
  56             case Const.LRETURN:
  57                 return Type.LONG;
  58             case Const.FRETURN:
  59                 return Type.FLOAT;
  60             case Const.DRETURN:
  61                 return Type.DOUBLE;
  62             case Const.ARETURN:
  63                 return Type.OBJECT;
  64             case Const.RETURN:
  65                 return Type.VOID;
  66             default: // Never reached
  67                 throw new ClassGenException("Unknown type " + _opcode);
  68         }
  69     }
  70 
  71 
  72     @Override
  73     public Class<?>[] getExceptions() {
  74         return new Class<?>[] {
  75             ExceptionConst.ILLEGAL_MONITOR_STATE
  76         };
  77     }
  78 
  79 
  80     /** @return type associated with the instruction
  81      */
  82     @Override
  83     public Type getType( final ConstantPoolGen cp ) {
  84         return getType();
  85     }
  86 }