/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

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package com.sun.org.apache.bcel.internal.generic;

import com.sun.org.apache.bcel.internal.ExceptionConst;

/**

 * CHECKCAST - Check whether object is of given type

 * <PRE>Stack: ..., objectref -&gt; ..., objectref</PRE>

 *

 */

public class CHECKCAST extends CPInstruction implements LoadClass, ExceptionThrower, StackProducer,

        StackConsumer {

    /**

     * Empty constructor needed for Instruction.readInstruction.

     * Not to be used otherwise.

     */

    CHECKCAST() {

    }

    /** Check whether object is of given type

     * @param index index to class in constant pool

     */

    public CHECKCAST(final int index) {

        super(com.sun.org.apache.bcel.internal.Const.CHECKCAST, index);

    }

    /** @return exceptions this instruction may cause

     */

    @Override

    public Class<?>[] getExceptions() {

        return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_CLASS_AND_INTERFACE_RESOLUTION,

            ExceptionConst.CLASS_CAST_EXCEPTION);

    }

    @Override

    public ObjectType getLoadClassType( final ConstantPoolGen cpg ) {

        Type t = getType(cpg);

        if (t instanceof ArrayType) {

            t = ((ArrayType) t).getBasicType();

        }

        return (t instanceof ObjectType) ? (ObjectType) t : null;

    }

    /**

     * Call corresponding visitor method(s). The order is:

     * Call visitor methods of implemented interfaces first, then

     * call methods according to the class hierarchy in descending order,

     * i.e., the most specific visitXXX() call comes last.

     *

     * @param v Visitor object

     */

    @Override

    public void accept( final Visitor v ) {

        v.visitLoadClass(this);

        v.visitExceptionThrower(this);

        v.visitStackProducer(this);

        v.visitStackConsumer(this);

        v.visitTypedInstruction(this);

        v.visitCPInstruction(this);

        v.visitCHECKCAST(this);

    }

}