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     */
018    package 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     * @version $Id: LoadInstruction.java 1152072 2011-07-29 01:54:05Z dbrosius $
025     * @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
026     */
027    public abstract class LoadInstruction extends LocalVariableInstruction implements PushInstruction {
028    
029        private static final long serialVersionUID = 3661924741022212247L;
030    
031    
032        /**
033         * Empty constructor needed for the Class.newInstance() statement in
034         * Instruction.readInstruction(). Not to be used otherwise.
035         * tag and length are defined in readInstruction and initFromFile, respectively.
036         */
037        LoadInstruction(short canon_tag, short c_tag) {
038            super(canon_tag, c_tag);
039        }
040    
041    
042        /**
043         * @param opcode Instruction opcode
044         * @param c_tag Instruction number for compact version, ALOAD_0, e.g.
045         * @param n local variable index (unsigned short)
046         */
047        protected LoadInstruction(short opcode, short c_tag, int n) {
048            super(opcode, c_tag, n);
049        }
050    
051    
052        /**
053         * Call corresponding visitor method(s). The order is:
054         * Call visitor methods of implemented interfaces first, then
055         * call methods according to the class hierarchy in descending order,
056         * i.e., the most specific visitXXX() call comes last.
057         *
058         * @param v Visitor object
059         */
060        @Override
061        public void accept( Visitor v ) {
062            v.visitStackProducer(this);
063            v.visitPushInstruction(this);
064            v.visitTypedInstruction(this);
065            v.visitLocalVariableInstruction(this);
066            v.visitLoadInstruction(this);
067        }
068    }