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