1 /*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5 /*
6 * Licensed to the Apache Software Foundation (ASF) under one or more
7 * contributor license agreements. See the NOTICE file distributed with
8 * this work for additional information regarding copyright ownership.
9 * The ASF licenses this file to You under the Apache License, Version 2.0
10 * (the "License"); you may not use this file except in compliance with
11 * the License. You may obtain a copy of the License at
12 *
13 * http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing, software
16 * distributed under the License is distributed on an "AS IS" BASIS,
17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18 * See the License for the specific language governing permissions and
19 * limitations under the License.
20 */
21
22 package com.sun.org.apache.bcel.internal.classfile;
23
24
25 import com.sun.org.apache.bcel.internal.Constants;
26 import java.io.*;
27
28 /**
29 * This class represents colection of local variables in a
30 * method. This attribute is contained in the <em>Code</em> attribute.
31 *
32 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
33 * @see Code
34 * @see LocalVariable
35 */
36 public class LocalVariableTable extends Attribute {
37 private int local_variable_table_length; // Table of local
38 private LocalVariable[] local_variable_table; // variables
39
40 /**
41 * Initialize from another object. Note that both objects use the same
42 * references (shallow copy). Use copy() for a physical copy.
43 */
44 public LocalVariableTable(LocalVariableTable c) {
45 this(c.getNameIndex(), c.getLength(), c.getLocalVariableTable(),
46 c.getConstantPool());
47 }
48
49 /**
50 * @param name_index Index in constant pool to `LocalVariableTable'
51 * @param length Content length in bytes
52 * @param local_variable_table Table of local variables
53 * @param constant_pool Array of constants
54 */
55 public LocalVariableTable(int name_index, int length,
56 LocalVariable[] local_variable_table,
57 ConstantPool constant_pool)
58 {
59 super(Constants.ATTR_LOCAL_VARIABLE_TABLE, name_index, length, constant_pool);
60 setLocalVariableTable(local_variable_table);
61 }
62
63 /**
64 * Construct object from file stream.
65 * @param name_index Index in constant pool
66 * @param length Content length in bytes
67 * @param file Input stream
68 * @param constant_pool Array of constants
69 * @throws IOException
70 */
71 LocalVariableTable(int name_index, int length, DataInputStream file,
72 ConstantPool constant_pool) throws IOException
73 {
74 this(name_index, length, (LocalVariable[])null, constant_pool);
75
76 local_variable_table_length = (file.readUnsignedShort());
77 local_variable_table = new LocalVariable[local_variable_table_length];
78
79 for(int i=0; i < local_variable_table_length; i++)
80 local_variable_table[i] = new LocalVariable(file, constant_pool);
81 }
82
83 /**
84 * Called by objects that are traversing the nodes of the tree implicitely
85 * defined by the contents of a Java class. I.e., the hierarchy of methods,
86 * fields, attributes, etc. spawns a tree of objects.
87 *
88 * @param v Visitor object
89 */
90 public void accept(Visitor v) {
91 v.visitLocalVariableTable(this);
92 }
93
94 /**
95 * Dump local variable table attribute to file stream in binary format.
96 *
97 * @param file Output file stream
98 * @throws IOException
99 */
100 public final void dump(DataOutputStream file) throws IOException
101 {
102 super.dump(file);
103 file.writeShort(local_variable_table_length);
104 for(int i=0; i < local_variable_table_length; i++)
105 local_variable_table[i].dump(file);
106 }
107
108 /**
109 * @return Array of local variables of method.
110 */
111 public final LocalVariable[] getLocalVariableTable() {
112 return local_variable_table;
113 }
114
115 /** @return first matching variable using index
116 */
117 public final LocalVariable getLocalVariable(int index) {
118 for(int i=0; i < local_variable_table_length; i++)
119 if(local_variable_table[i].getIndex() == index)
120 return local_variable_table[i];
121
122 return null;
123 }
124
125 public final void setLocalVariableTable(LocalVariable[] local_variable_table)
126 {
127 this.local_variable_table = local_variable_table;
128 local_variable_table_length = (local_variable_table == null)? 0 :
129 local_variable_table.length;
130 }
131
132 /**
133 * @return String representation.
134 */
135 public final String toString() {
136 StringBuffer buf = new StringBuffer("");
137
138 for(int i=0; i < local_variable_table_length; i++) {
139 buf.append(local_variable_table[i].toString());
140
141 if(i < local_variable_table_length - 1)
142 buf.append('\n');
143 }
144
145 return buf.toString();
146 }
147
148 /**
149 * @return deep copy of this attribute
150 */
151 public Attribute copy(ConstantPool constant_pool) {
152 LocalVariableTable c = (LocalVariableTable)clone();
153
154 c.local_variable_table = new LocalVariable[local_variable_table_length];
155 for(int i=0; i < local_variable_table_length; i++)
156 c.local_variable_table[i] = local_variable_table[i].copy();
157
158 c.constant_pool = constant_pool;
159 return c;
160 }
161
162 public final int getTableLength() { return local_variable_table_length; }
163 }