1 /* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5 /* 6 * Licensed to the Apache Software Foundation (ASF) under one or more 7 * contributor license agreements. See the NOTICE file distributed with 8 * this work for additional information regarding copyright ownership. 9 * The ASF licenses this file to You under the Apache License, Version 2.0 10 * (the "License"); you may not use this file except in compliance with 11 * the License. You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, software 16 * distributed under the License is distributed on an "AS IS" BASIS, 17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 18 * See the License for the specific language governing permissions and 19 * limitations under the License. 20 */ 21 22 package com.sun.org.apache.bcel.internal.generic; 23 24 import com.sun.org.apache.bcel.internal.ExceptionConstants; 25 /** 26 * CHECKCAST - Check whether object is of given type 27 * <PRE>Stack: ..., objectref -> ..., objectref</PRE> 28 * 29 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A> 30 */ 31 public class CHECKCAST extends CPInstruction 32 implements LoadClass, ExceptionThrower, StackProducer, StackConsumer { 33 /** 34 * Empty constructor needed for the Class.newInstance() statement in 35 * Instruction.readInstruction(). Not to be used otherwise. 36 */ 37 CHECKCAST() {} 38 39 /** Check whether object is of given type 40 * @param n index to class in constant pool 41 */ 42 public CHECKCAST(int index) { 43 super(com.sun.org.apache.bcel.internal.Constants.CHECKCAST, index); 44 } 45 46 /** @return exceptions this instruction may cause 47 */ 48 public Class[] getExceptions() { 49 Class[] cs = new Class[1 + ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length]; 50 51 System.arraycopy(ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION, 0, 52 cs, 0, ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length); 53 cs[ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length] = 54 ExceptionConstants.CLASS_CAST_EXCEPTION; 55 return cs; 56 } 57 58 public ObjectType getLoadClassType(ConstantPoolGen cpg) { 59 Type t = getType(cpg); 60 61 if(t instanceof ArrayType) 62 t = ((ArrayType) t).getBasicType(); 63 64 return (t instanceof ObjectType)? (ObjectType) t : null; 65 } 66 67 /** 68 * Call corresponding visitor method(s). The order is: 69 * Call visitor methods of implemented interfaces first, then 70 * call methods according to the class hierarchy in descending order, 71 * i.e., the most specific visitXXX() call comes last. 72 * 73 * @param v Visitor object 74 */ 75 public void accept(Visitor v) { 76 v.visitLoadClass(this); 77 v.visitExceptionThrower(this); 78 v.visitStackProducer(this); 79 v.visitStackConsumer(this); 80 v.visitTypedInstruction(this); 81 v.visitCPInstruction(this); 82 v.visitCHECKCAST(this); 83 } 84 }