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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: MULTIANEWARRAY.html 1021978 2017-12-09 17:38:21Z ggregory $
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 }