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 *
017 */
018package org.apache.bcel.generic;
019
020/**
021 * Denotes an unparameterized instruction to load a value from a local
022 * variable, e.g. ILOAD.
023 *
024 */
025public abstract class LoadInstruction extends LocalVariableInstruction implements PushInstruction {
026
027    /**
028     * Empty constructor needed for Instruction.readInstruction.
029     * Not to be used otherwise.
030     * tag and length are defined in readInstruction and initFromFile, respectively.
031     */
032    LoadInstruction(final short canon_tag, final short c_tag) {
033        super(canon_tag, c_tag);
034    }
035
036
037    /**
038     * @param opcode Instruction opcode
039     * @param c_tag Instruction number for compact version, ALOAD_0, e.g.
040     * @param n local variable index (unsigned short)
041     */
042    protected LoadInstruction(final short opcode, final short c_tag, final int n) {
043        super(opcode, c_tag, n);
044    }
045
046
047    /**
048     * Call corresponding visitor method(s). The order is:
049     * Call visitor methods of implemented interfaces first, then
050     * call methods according to the class hierarchy in descending order,
051     * i.e., the most specific visitXXX() call comes last.
052     *
053     * @param v Visitor object
054     */
055    @Override
056    public void accept( final Visitor v ) {
057        v.visitStackProducer(this);
058        v.visitPushInstruction(this);
059        v.visitTypedInstruction(this);
060        v.visitLocalVariableInstruction(this);
061        v.visitLoadInstruction(this);
062    }
063}