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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.ExceptionConst;
21  
22  /**
23   * INSTANCEOF - Determine if object is of given type
24   * <PRE>Stack: ..., objectref -&gt; ..., result</PRE>
25   *
26   */
27  public class INSTANCEOF extends CPInstruction implements LoadClass, ExceptionThrower,
28          StackProducer, StackConsumer {
29  
30      /**
31       * Empty constructor needed for Instruction.readInstruction.
32       * Not to be used otherwise.
33       */
34      INSTANCEOF() {
35      }
36  
37  
38      public INSTANCEOF(final int index) {
39          super(org.apache.bcel.Const.INSTANCEOF, index);
40      }
41  
42  
43      @Override
44      public Class<?>[] getExceptions() {
45          return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_CLASS_AND_INTERFACE_RESOLUTION);
46      }
47  
48  
49      @Override
50      public ObjectType getLoadClassType( final ConstantPoolGen cpg ) {
51          Type t = getType(cpg);
52          if (t instanceof ArrayType) {
53              t = ((ArrayType) t).getBasicType();
54          }
55          return (t instanceof ObjectType="../../../../org/apache/bcel/generic/ObjectType.html#ObjectType">ObjectType) ? (ObjectType) t : null;
56      }
57  
58  
59      /**
60       * Call corresponding visitor method(s). The order is:
61       * Call visitor methods of implemented interfaces first, then
62       * call methods according to the class hierarchy in descending order,
63       * i.e., the most specific visitXXX() call comes last.
64       *
65       * @param v Visitor object
66       */
67      @Override
68      public void accept( final Visitor v ) {
69          v.visitLoadClass(this);
70          v.visitExceptionThrower(this);
71          v.visitStackProducer(this);
72          v.visitStackConsumer(this);
73          v.visitTypedInstruction(this);
74          v.visitCPInstruction(this);
75          v.visitINSTANCEOF(this);
76      }
77  }