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 22 /** 23 * Returnaddress, the type JSR or JSR_W instructions push upon the stack. 24 * 25 * see vmspec2 �3.3.3 26 * @version $Id$ 27 */ 28 public class ReturnaddressType extends Type { 29 30 public static final ReturnaddressType NO_TARGET = new ReturnaddressType(); 31 private InstructionHandle returnTarget; 32 33 34 /** 35 * A Returnaddress [that doesn't know where to return to]. 36 */ ReturnaddressType()37 private ReturnaddressType() { 38 super(Const.T_ADDRESS, "<return address>"); 39 } 40 41 42 /** 43 * Creates a ReturnaddressType object with a target. 44 */ ReturnaddressType(final InstructionHandle returnTarget)45 public ReturnaddressType(final InstructionHandle returnTarget) { 46 super(Const.T_ADDRESS, "<return address targeting " + returnTarget + ">"); 47 this.returnTarget = returnTarget; 48 } 49 50 51 /** @return a hash code value for the object. 52 */ 53 @Override hashCode()54 public int hashCode() { 55 if (returnTarget == null) { 56 return 0; 57 } 58 return returnTarget.hashCode(); 59 } 60 61 62 /** 63 * Returns if the two Returnaddresses refer to the same target. 64 */ 65 @Override equals( final Object rat )66 public boolean equals( final Object rat ) { 67 if (!(rat instanceof ReturnaddressType)) { 68 return false; 69 } 70 final ReturnaddressType that = (ReturnaddressType) rat; 71 if (this.returnTarget == null || that.returnTarget == null) { 72 return that.returnTarget == this.returnTarget; 73 } 74 return that.returnTarget.equals(this.returnTarget); 75 } 76 77 78 /** 79 * @return the target of this ReturnaddressType 80 */ getTarget()81 public InstructionHandle getTarget() { 82 return returnTarget; 83 } 84 } 85