001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 * 017 */ 018package org.apache.bcel.generic; 019 020import org.apache.bcel.ExceptionConst; 021 022/** 023 * INSTANCEOF - Determine if object is of given type 024 * <PRE>Stack: ..., objectref -> ..., result</PRE> 025 * 026 */ 027public class INSTANCEOF extends CPInstruction implements LoadClass, ExceptionThrower, 028 StackProducer, StackConsumer { 029 030 /** 031 * Empty constructor needed for Instruction.readInstruction. 032 * Not to be used otherwise. 033 */ 034 INSTANCEOF() { 035 } 036 037 038 public INSTANCEOF(final int index) { 039 super(org.apache.bcel.Const.INSTANCEOF, index); 040 } 041 042 043 @Override 044 public Class<?>[] getExceptions() { 045 return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_CLASS_AND_INTERFACE_RESOLUTION); 046 } 047 048 049 @Override 050 public ObjectType getLoadClassType( final ConstantPoolGen cpg ) { 051 Type t = getType(cpg); 052 if (t instanceof ArrayType) { 053 t = ((ArrayType) t).getBasicType(); 054 } 055 return (t instanceof ObjectType) ? (ObjectType) t : null; 056 } 057 058 059 /** 060 * Call corresponding visitor method(s). The order is: 061 * Call visitor methods of implemented interfaces first, then 062 * call methods according to the class hierarchy in descending order, 063 * i.e., the most specific visitXXX() call comes last. 064 * 065 * @param v Visitor object 066 */ 067 @Override 068 public void accept( final Visitor v ) { 069 v.visitLoadClass(this); 070 v.visitExceptionThrower(this); 071 v.visitStackProducer(this); 072 v.visitStackConsumer(this); 073 v.visitTypedInstruction(this); 074 v.visitCPInstruction(this); 075 v.visitINSTANCEOF(this); 076 } 077}