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      1 /*
      2  * Licensed to the Apache Software Foundation (ASF) under one or more
      3  * contributor license agreements.  See the NOTICE file distributed with
      4  * this work for additional information regarding copyright ownership.
      5  * The ASF licenses this file to You under the Apache License, Version 2.0
      6  * (the "License"); you may not use this file except in compliance with
      7  * the License.  You may obtain a copy of the License at
      8  *
      9  *      http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  *  Unless required by applicable law or agreed to in writing, software
     12  *  distributed under the License is distributed on an "AS IS" BASIS,
     13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  *  See the License for the specific language governing permissions and
     15  *  limitations under the License.
     16  *
     17  */
     18 package org.apache.bcel.generic;
     19 
     20 import java.io.DataOutputStream;
     21 import java.io.IOException;
     22 
     23 import org.apache.bcel.ExceptionConst;
     24 import org.apache.bcel.classfile.ConstantPool;
     25 import org.apache.bcel.util.ByteSequence;
     26 
     27 /**
     28  * MULTIANEWARRAY - Create new mutidimensional array of references
     29  * <PRE>Stack: ..., count1, [count2, ...] -&gt; ..., arrayref</PRE>
     30  *
     31  * @version $Id$
     32  */
     33 public class MULTIANEWARRAY extends CPInstruction implements LoadClass, AllocationInstruction,
     34         ExceptionThrower {
     35 
     36     private short dimensions;
     37 
     38 
     39     /**
     40      * Empty constructor needed for Instruction.readInstruction.
     41      * Not to be used otherwise.
     42      */
     43     MULTIANEWARRAY() {
     44     }
     45 
     46 
     47     public MULTIANEWARRAY(final int index, final short dimensions) {
     48         super(org.apache.bcel.Const.MULTIANEWARRAY, index);
     49         if (dimensions < 1) {
     50             throw new ClassGenException("Invalid dimensions value: " + dimensions);
     51         }
     52         this.dimensions = dimensions;
     53         super.setLength(4);
     54     }
     55 
     56 
     57     /**
     58      * Dump instruction as byte code to stream out.
     59      * @param out Output stream
     60      */
     61     @Override
     62     public void dump( final DataOutputStream out ) throws IOException {
     63         out.writeByte(super.getOpcode());
     64         out.writeShort(super.getIndex());
     65         out.writeByte(dimensions);
     66     }
     67 
     68 
     69     /**
     70      * Read needed data (i.e., no. dimension) from file.
     71      */
     72     @Override
     73     protected void initFromFile( final ByteSequence bytes, final boolean wide ) throws IOException {
     74         super.initFromFile(bytes, wide);
     75         dimensions = bytes.readByte();
     76         super.setLength(4);
     77     }
     78 
     79 
     80     /**
     81      * @return number of dimensions to be created
     82      */
     83     public final short getDimensions() {
     84         return dimensions;
     85     }
     86 
     87 
     88     /**
     89      * @return mnemonic for instruction
     90      */
     91     @Override
     92     public String toString( final boolean verbose ) {
     93         return super.toString(verbose) + " " + super.getIndex() + " " + dimensions;
     94     }
     95 
     96 
     97     /**
     98      * @return mnemonic for instruction with symbolic references resolved
     99      */
    100     @Override
    101     public String toString( final ConstantPool cp ) {
    102         return super.toString(cp) + " " + dimensions;
    103     }
    104 
    105 
    106     /**
    107      * Also works for instructions whose stack effect depends on the
    108      * constant pool entry they reference.
    109      * @return Number of words consumed from stack by this instruction
    110      */
    111     @Override
    112     public int consumeStack( final ConstantPoolGen cpg ) {
    113         return dimensions;
    114     }
    115 
    116 
    117     @Override
    118     public Class<?>[] getExceptions() {
    119         return ExceptionConst.createExceptions(ExceptionConst.EXCS.EXCS_CLASS_AND_INTERFACE_RESOLUTION,
    120             ExceptionConst.ILLEGAL_ACCESS_ERROR,
    121             ExceptionConst.NEGATIVE_ARRAY_SIZE_EXCEPTION);
    122     }
    123 
    124 
    125     @Override
    126     public ObjectType getLoadClassType( final ConstantPoolGen cpg ) {
    127         Type t = getType(cpg);
    128         if (t instanceof ArrayType) {
    129             t = ((ArrayType) t).getBasicType();
    130         }
    131         return (t instanceof ObjectType) ? (ObjectType) t : null;
    132     }
    133 
    134 
    135     /**
    136      * Call corresponding visitor method(s). The order is:
    137      * Call visitor methods of implemented interfaces first, then
    138      * call methods according to the class hierarchy in descending order,
    139      * i.e., the most specific visitXXX() call comes last.
    140      *
    141      * @param v Visitor object
    142      */
    143     @Override
    144     public void accept( final Visitor v ) {
    145         v.visitLoadClass(this);
    146         v.visitAllocationInstruction(this);
    147         v.visitExceptionThrower(this);
    148         v.visitTypedInstruction(this);
    149         v.visitCPInstruction(this);
    150         v.visitMULTIANEWARRAY(this);
    151     }
    152 }
    153