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1   /*
2    * Copyright  2000-2004 The Apache Software Foundation
3    *
4    *  Licensed under the Apache License, Version 2.0 (the "License"); 
5    *  you may not use this file except in compliance with the License.
6    *  You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   *  Unless required by applicable law or agreed to in writing, software
11   *  distributed under the License is distributed on an "AS IS" BASIS,
12   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   *  See the License for the specific language governing permissions and
14   *  limitations under the License. 
15   *
16   */
17  package org.apache.bcel.generic;
18  
19  import java.io.DataOutputStream;
20  import java.io.IOException;
21  import org.apache.bcel.ExceptionConstants;
22  import org.apache.bcel.classfile.ConstantPool;
23  import org.apache.bcel.util.ByteSequence;
24  
25  /*** 
26   * MULTIANEWARRAY - Create new mutidimensional array of references
27   * <PRE>Stack: ..., count1, [count2, ...] -&gt; ..., arrayref</PRE>
28   *
29   * @version $Id: MULTIANEWARRAY.java 386056 2006-03-15 11:31:56Z tcurdt $
30   * @author  <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
31   */
32  public class MULTIANEWARRAY extends CPInstruction implements LoadClass, AllocationInstruction,
33          ExceptionThrower {
34  
35      private short dimensions;
36  
37  
38      /***
39       * Empty constructor needed for the Class.newInstance() statement in
40       * Instruction.readInstruction(). Not to be used otherwise.
41       */
42      MULTIANEWARRAY() {
43      }
44  
45  
46      public MULTIANEWARRAY(int index, short dimensions) {
47          super(org.apache.bcel.Constants.MULTIANEWARRAY, index);
48          if (dimensions < 1) {
49              throw new ClassGenException("Invalid dimensions value: " + dimensions);
50          }
51          this.dimensions = dimensions;
52          length = 4;
53      }
54  
55  
56      /***
57       * Dump instruction as byte code to stream out.
58       * @param out Output stream
59       */
60      public void dump( DataOutputStream out ) throws IOException {
61          out.writeByte(opcode);
62          out.writeShort(index);
63          out.writeByte(dimensions);
64      }
65  
66  
67      /***
68       * Read needed data (i.e., no. dimension) from file.
69       */
70      protected void initFromFile( ByteSequence bytes, boolean wide ) throws IOException {
71          super.initFromFile(bytes, wide);
72          dimensions = bytes.readByte();
73          length = 4;
74      }
75  
76  
77      /***
78       * @return number of dimensions to be created
79       */
80      public final short getDimensions() {
81          return dimensions;
82      }
83  
84  
85      /***
86       * @return mnemonic for instruction
87       */
88      public String toString( boolean verbose ) {
89          return super.toString(verbose) + " " + index + " " + dimensions;
90      }
91  
92  
93      /***
94       * @return mnemonic for instruction with symbolic references resolved
95       */
96      public String toString( ConstantPool cp ) {
97          return super.toString(cp) + " " + dimensions;
98      }
99  
100 
101     /***
102      * Also works for instructions whose stack effect depends on the
103      * constant pool entry they reference.
104      * @return Number of words consumed from stack by this instruction
105      */
106     public int consumeStack( ConstantPoolGen cpg ) {
107         return dimensions;
108     }
109 
110 
111     public Class[] getExceptions() {
112         Class[] cs = new Class[2 + ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length];
113         System.arraycopy(ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION, 0, cs, 0,
114                 ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length);
115         cs[ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length + 1] = ExceptionConstants.NEGATIVE_ARRAY_SIZE_EXCEPTION;
116         cs[ExceptionConstants.EXCS_CLASS_AND_INTERFACE_RESOLUTION.length] = ExceptionConstants.ILLEGAL_ACCESS_ERROR;
117         return cs;
118     }
119 
120 
121     public ObjectType getLoadClassType( ConstantPoolGen cpg ) {
122         Type t = getType(cpg);
123         if (t instanceof ArrayType) {
124             t = ((ArrayType) t).getBasicType();
125         }
126         return (t instanceof ObjectType) ? (ObjectType) t : null;
127     }
128 
129 
130     /***
131      * Call corresponding visitor method(s). The order is:
132      * Call visitor methods of implemented interfaces first, then
133      * call methods according to the class hierarchy in descending order,
134      * i.e., the most specific visitXXX() call comes last.
135      *
136      * @param v Visitor object
137      */
138     public void accept( Visitor v ) {
139         v.visitLoadClass(this);
140         v.visitAllocationInstruction(this);
141         v.visitExceptionThrower(this);
142         v.visitTypedInstruction(this);
143         v.visitCPInstruction(this);
144         v.visitMULTIANEWARRAY(this);
145     }
146 }