/*
 * 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;

/**
 * INSTANCEOF - Determine if object is of given type
 *
 * <PRE>
 * Stack: ..., objectref -&gt; ..., result
 * </PRE>
 */
public class INSTANCEOF extends CPInstruction implements LoadClass, ExceptionThrower, StackProducer, StackConsumer {

    /**
     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
     */
    INSTANCEOF() {
    }

    public INSTANCEOF(final int index) {
        super(com.sun.org.apache.bcel.internal.Const.INSTANCEOF, index);
    }

    /**
     * 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.visitINSTANCEOF(this);
    }

    @Override
    public Class<?>[] getExceptions() {
        return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_CLASS_AND_INTERFACE_RESOLUTION);
    }

    @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;
    }
}
