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
020import java.io.DataOutputStream;
021import java.io.IOException;
022
023import org.apache.bcel.ExceptionConst;
024import org.apache.bcel.classfile.ConstantPool;
025import org.apache.bcel.util.ByteSequence;
026
027/**
028 * MULTIANEWARRAY - Create new mutidimensional array of references
029 * <PRE>Stack: ..., count1, [count2, ...] -&gt; ..., arrayref</PRE>
030 *
031 */
032public class MULTIANEWARRAY extends CPInstruction implements LoadClass, AllocationInstruction,
033        ExceptionThrower {
034
035    private short dimensions;
036
037
038    /**
039     * Empty constructor needed for Instruction.readInstruction.
040     * Not to be used otherwise.
041     */
042    MULTIANEWARRAY() {
043    }
044
045
046    public MULTIANEWARRAY(final int index, final short dimensions) {
047        super(org.apache.bcel.Const.MULTIANEWARRAY, index);
048        if (dimensions < 1) {
049            throw new ClassGenException("Invalid dimensions value: " + dimensions);
050        }
051        this.dimensions = dimensions;
052        super.setLength(4);
053    }
054
055
056    /**
057     * Dump instruction as byte code to stream out.
058     * @param out Output stream
059     */
060    @Override
061    public void dump( final DataOutputStream out ) throws IOException {
062        out.writeByte(super.getOpcode());
063        out.writeShort(super.getIndex());
064        out.writeByte(dimensions);
065    }
066
067
068    /**
069     * Read needed data (i.e., no. dimension) from file.
070     */
071    @Override
072    protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException {
073        super.initFromFile(bytes, wide);
074        dimensions = bytes.readByte();
075        super.setLength(4);
076    }
077
078
079    /**
080     * @return number of dimensions to be created
081     */
082    public final short getDimensions() {
083        return dimensions;
084    }
085
086
087    /**
088     * @return mnemonic for instruction
089     */
090    @Override
091    public String toString( final boolean verbose ) {
092        return super.toString(verbose) + " " + super.getIndex() + " " + dimensions;
093    }
094
095
096    /**
097     * @return mnemonic for instruction with symbolic references resolved
098     */
099    @Override
100    public String toString( final ConstantPool cp ) {
101        return super.toString(cp) + " " + dimensions;
102    }
103
104
105    /**
106     * Also works for instructions whose stack effect depends on the
107     * constant pool entry they reference.
108     * @return Number of words consumed from stack by this instruction
109     */
110    @Override
111    public int consumeStack( final ConstantPoolGen cpg ) {
112        return dimensions;
113    }
114
115
116    @Override
117    public Class<?>[] getExceptions() {
118        return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_CLASS_AND_INTERFACE_RESOLUTION,
119            ExceptionConst.ILLEGAL_ACCESS_ERROR,
120            ExceptionConst.NEGATIVE_ARRAY_SIZE_EXCEPTION);
121    }
122
123
124    @Override
125    public ObjectType getLoadClassType( final ConstantPoolGen cpg ) {
126        Type t = getType(cpg);
127        if (t instanceof ArrayType) {
128            t = ((ArrayType) t).getBasicType();
129        }
130        return (t instanceof ObjectType) ? (ObjectType) t : null;
131    }
132
133
134    /**
135     * Call corresponding visitor method(s). The order is:
136     * Call visitor methods of implemented interfaces first, then
137     * call methods according to the class hierarchy in descending order,
138     * i.e., the most specific visitXXX() call comes last.
139     *
140     * @param v Visitor object
141     */
142    @Override
143    public void accept( final Visitor v ) {
144        v.visitLoadClass(this);
145        v.visitAllocationInstruction(this);
146        v.visitExceptionThrower(this);
147        v.visitTypedInstruction(this);
148        v.visitCPInstruction(this);
149        v.visitMULTIANEWARRAY(this);
150    }
151}