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 * 025 * <PRE> 026 * Stack: ..., objectref -> ..., result 027 * </PRE> 028 * 029 */ 030public class INSTANCEOF extends CPInstruction implements LoadClass, ExceptionThrower, StackProducer, StackConsumer { 031 032 /** 033 * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise. 034 */ 035 INSTANCEOF() { 036 } 037 038 public INSTANCEOF(final int index) { 039 super(org.apache.bcel.Const.INSTANCEOF, index); 040 } 041 042 /** 043 * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call 044 * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last. 045 * 046 * @param v Visitor object 047 */ 048 @Override 049 public void accept(final Visitor v) { 050 v.visitLoadClass(this); 051 v.visitExceptionThrower(this); 052 v.visitStackProducer(this); 053 v.visitStackConsumer(this); 054 v.visitTypedInstruction(this); 055 v.visitCPInstruction(this); 056 v.visitINSTANCEOF(this); 057 } 058 059 @Override 060 public Class<?>[] getExceptions() { 061 return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_CLASS_AND_INTERFACE_RESOLUTION); 062 } 063 064 @Override 065 public ObjectType getLoadClassType(final ConstantPoolGen cpg) { 066 Type t = getType(cpg); 067 if (t instanceof ArrayType) { 068 t = ((ArrayType) t).getBasicType(); 069 } 070 return t instanceof ObjectType ? (ObjectType) t : null; 071 } 072}