1 /* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5 package com.sun.org.apache.bcel.internal.generic; 6 7 /* ==================================================================== 8 * The Apache Software License, Version 1.1 9 * 10 * Copyright (c) 2001 The Apache Software Foundation. All rights 11 * reserved. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 20 * 2. Redistributions in binary form must reproduce the above copyright 21 * notice, this list of conditions and the following disclaimer in 22 * the documentation and/or other materials provided with the 23 * distribution. 24 * 25 * 3. The end-user documentation included with the redistribution, 26 * if any, must include the following acknowledgment: 27 * "This product includes software developed by the 28 * Apache Software Foundation (http://www.apache.org/)." 29 * Alternately, this acknowledgment may appear in the software itself, 30 * if and wherever such third-party acknowledgments normally appear. 31 * 32 * 4. The names "Apache" and "Apache Software Foundation" and 33 * "Apache BCEL" must not be used to endorse or promote products 34 * derived from this software without prior written permission. For 35 * written permission, please contact apache@apache.org. 36 * 37 * 5. Products derived from this software may not be called "Apache", 38 * "Apache BCEL", nor may "Apache" appear in their name, without 39 * prior written permission of the Apache Software Foundation. 40 * 41 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED 42 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR 45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 52 * SUCH DAMAGE. 53 * ==================================================================== 54 * 55 * This software consists of voluntary contributions made by many 56 * individuals on behalf of the Apache Software Foundation. For more 57 * information on the Apache Software Foundation, please see 58 * <http://www.apache.org/>. 59 */ 60 import com.sun.org.apache.bcel.internal.ExceptionConstants; 61 /** 62 * CHECKCAST - Check whether object is of given type 63 * <PRE>Stack: ..., objectref -> ..., objectref</PRE> 64 * 65 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> 66 */ 67 public class CHECKCAST extends CPInstruction 68 implements LoadClass, ExceptionThrower, StackProducer, StackConsumer { 69 /** 70 * Empty constructor needed for the Class.newInstance() statement in 71 * Instruction.readInstruction(). Not to be used otherwise. 72 */ CHECKCAST()73 CHECKCAST() {} 74 75 /** Check whether object is of given type 76 * @param n index to class in constant pool 77 */ CHECKCAST(int index)78 public CHECKCAST(int index) { 79 super(com.sun.org.apache.bcel.internal.Constants.CHECKCAST, index); 80 } 81 82 /** @return exceptions this instruction may cause 83 */ getExceptions()84 public Class[] getExceptions() { 85 Class[] cs = new Class[1 + ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length]; 86 87 System.arraycopy(ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION, 0, 88 cs, 0, ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length); 89 cs[ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length] = 90 ExceptionConstants.CLASS_CAST_EXCEPTION; 91 return cs; 92 } 93 getLoadClassType(ConstantPoolGen cpg)94 public ObjectType getLoadClassType(ConstantPoolGen cpg) { 95 Type t = getType(cpg); 96 97 if(t instanceof ArrayType) 98 t = ((ArrayType) t).getBasicType(); 99 100 return (t instanceof ObjectType)? (ObjectType) t : null; 101 } 102 103 /** 104 * Call corresponding visitor method(s). The order is: 105 * Call visitor methods of implemented interfaces first, then 106 * call methods according to the class hierarchy in descending order, 107 * i.e., the most specific visitXXX() call comes last. 108 * 109 * @param v Visitor object 110 */ accept(Visitor v)111 public void accept(Visitor v) { 112 v.visitLoadClass(this); 113 v.visitExceptionThrower(this); 114 v.visitStackProducer(this); 115 v.visitStackConsumer(this); 116 v.visitTypedInstruction(this); 117 v.visitCPInstruction(this); 118 v.visitCHECKCAST(this); 119 } 120 } 121