    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 */
    017package org.apache.bcel.generic;
    018
    019/**
    020 * IFNULL - Branch if reference is not null
    021 *
    022 * <PRE>
    023 * Stack: ..., reference -&gt; ...
    024 * </PRE>
    025 */
    026public class IFNULL extends IfInstruction {
    027
    028    /**
    029     * Empty constructor needed for Instruction.readInstruction. Not to be used otherwise.
    030     */
    031    IFNULL() {
    032    }
    033
    034    public IFNULL(final InstructionHandle target) {
    035        super(org.apache.bcel.Const.IFNULL, target);
    036    }
    037
    038    /**
    039     * Call corresponding visitor method(s). The order is: Call visitor methods of implemented interfaces first, then call
    040     * methods according to the class hierarchy in descending order, i.e., the most specific visitXXX() call comes last.
    041     *
    042     * @param v Visitor object
    043     */
    044    @Override
    045    public void accept(final Visitor v) {
    046        v.visitStackConsumer(this);
    047        v.visitBranchInstruction(this);
    048        v.visitIfInstruction(this);
    049        v.visitIFNULL(this);
    050    }
    051
    052    /**
    053     * @return negation of instruction
    054     */
    055    @Override
    056    public IfInstruction negate() {
    057        return new IFNONNULL(super.getTarget());
    058    }
    059}