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
22package com.sun.org.apache.bcel.internal.generic;
23
24import com.sun.org.apache.bcel.internal.ExceptionConst;
25
26/**
27 * CHECKCAST - Check whether object is of given type
28 * <PRE>Stack: ..., objectref -&gt; ..., objectref</PRE>
29 *
30 * @version $Id: CHECKCAST.java 1747278 2016-06-07 17:28:43Z britter $
31 */
32public class CHECKCAST extends CPInstruction implements LoadClass, ExceptionThrower, StackProducer,
33        StackConsumer {
34
35    /**
36     * Empty constructor needed for the Class.newInstance() statement in
37     * Instruction.readInstruction(). Not to be used otherwise.
38     */
39    CHECKCAST() {
40    }
41
42
43    /** Check whether object is of given type
44     * @param index index to class in constant pool
45     */
46    public CHECKCAST(final int index) {
47        super(com.sun.org.apache.bcel.internal.Const.CHECKCAST, index);
48    }
49
50
51    /** @return exceptions this instruction may cause
52     */
53    @Override
54    public Class<?>[] getExceptions() {
55        return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_CLASS_AND_INTERFACE_RESOLUTION,
56            ExceptionConst.CLASS_CAST_EXCEPTION);
57    }
58
59
60    @Override
61    public ObjectType getLoadClassType( final ConstantPoolGen cpg ) {
62        Type t = getType(cpg);
63        if (t instanceof ArrayType) {
64            t = ((ArrayType) t).getBasicType();
65        }
66        return (t instanceof ObjectType) ? (ObjectType) t : null;
67    }
68
69
70    /**
71     * Call corresponding visitor method(s). The order is:
72     * Call visitor methods of implemented interfaces first, then
73     * call methods according to the class hierarchy in descending order,
74     * i.e., the most specific visitXXX() call comes last.
75     *
76     * @param v Visitor object
77     */
78    @Override
79    public void accept( final Visitor v ) {
80        v.visitLoadClass(this);
81        v.visitExceptionThrower(this);
82        v.visitStackProducer(this);
83        v.visitStackConsumer(this);
84        v.visitTypedInstruction(this);
85        v.visitCPInstruction(this);
86        v.visitCHECKCAST(this);
87    }
88}
89