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 import java.io.DataInput;
25 import java.io.DataOutputStream;
26 import java.io.IOException;
27
28 import com.sun.org.apache.bcel.internal.Const;
29
30 /**
31 * This class represents colection of local variables in a
32 * method. This attribute is contained in the <em>Code</em> attribute.
33 *
34 * @version $Id: LocalVariableTable.java 1749603 2016-06-21 20:50:19Z ggregory $
35 * @see Code
36 * @see LocalVariable
37 */
38 public class LocalVariableTable extends Attribute {
39
40 private LocalVariable[] local_variable_table; // variables
41
42
43 /**
44 * Initialize from another object. Note that both objects use the same
45 * references (shallow copy). Use copy() for a physical copy.
46 */
47 public LocalVariableTable(final LocalVariableTable c) {
48 this(c.getNameIndex(), c.getLength(), c.getLocalVariableTable(), c.getConstantPool());
49 }
50
51
52 /**
53 * @param name_index Index in constant pool to `LocalVariableTable'
54 * @param length Content length in bytes
55 * @param local_variable_table Table of local variables
56 * @param constant_pool Array of constants
57 */
58 public LocalVariableTable(final int name_index, final int length, final LocalVariable[] local_variable_table,
59 final ConstantPool constant_pool) {
60 super(Const.ATTR_LOCAL_VARIABLE_TABLE, name_index, length, constant_pool);
61 this.local_variable_table = local_variable_table;
62 }
63
64
65 /**
66 * Construct object from input stream.
67 * @param name_index Index in constant pool
68 * @param length Content length in bytes
69 * @param input Input stream
70 * @param constant_pool Array of constants
71 * @throws IOException
72 */
73 LocalVariableTable(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool)
74 throws IOException {
75 this(name_index, length, (LocalVariable[]) null, constant_pool);
76 final int local_variable_table_length = input.readUnsignedShort();
77 local_variable_table = new LocalVariable[local_variable_table_length];
78 for (int i = 0; i < local_variable_table_length; i++) {
79 local_variable_table[i] = new LocalVariable(input, constant_pool);
80 }
81 }
82
83
84 /**
85 * Called by objects that are traversing the nodes of the tree implicitely
86 * defined by the contents of a Java class. I.e., the hierarchy of methods,
87 * fields, attributes, etc. spawns a tree of objects.
88 *
89 * @param v Visitor object
90 */
91 @Override
92 public void accept( final Visitor v ) {
93 v.visitLocalVariableTable(this);
94 }
95
96
97 /**
98 * Dump local variable table attribute to file stream in binary format.
99 *
100 * @param file Output file stream
101 * @throws IOException
102 */
103 @Override
104 public final void dump( final DataOutputStream file ) throws IOException {
105 super.dump(file);
106 file.writeShort(local_variable_table.length);
107 for (final LocalVariable variable : local_variable_table) {
108 variable.dump(file);
109 }
110 }
111
112
113 /**
114 * @return Array of local variables of method.
115 */
116 public final LocalVariable[] getLocalVariableTable() {
117 return local_variable_table;
118 }
119
120
121 /**
122 *
123 * @param index the variable slot
124 *
125 * @return the first LocalVariable that matches the slot or null if not found
126 *
127 * @deprecated since 5.2 because multiple variables can share the
128 * same slot, use getLocalVariable(int index, int pc) instead.
129 */
130 @java.lang.Deprecated
131 public final LocalVariable getLocalVariable( final int index ) {
132 for (final LocalVariable variable : local_variable_table) {
133 if (variable.getIndex() == index) {
134 return variable;
135 }
136 }
137 return null;
138 }
139
140
141 /**
142 *
143 * @param index the variable slot
144 * @param pc the current pc that this variable is alive
145 *
146 * @return the LocalVariable that matches or null if not found
147 */
148 public final LocalVariable getLocalVariable( final int index, final int pc ) {
149 for (final LocalVariable variable : local_variable_table) {
150 if (variable.getIndex() == index) {
151 final int start_pc = variable.getStartPC();
152 final int end_pc = start_pc + variable.getLength();
153 if ((pc >= start_pc) && (pc <= end_pc)) {
154 return variable;
155 }
156 }
157 }
158 return null;
159 }
160
161
162 public final void setLocalVariableTable( final LocalVariable[] local_variable_table ) {
163 this.local_variable_table = local_variable_table;
164 }
165
166
167 /**
168 * @return String representation.
169 */
170 @Override
171 public final String toString() {
172 final StringBuilder buf = new StringBuilder();
173 for (int i = 0; i < local_variable_table.length; i++) {
174 buf.append(local_variable_table[i]);
175 if (i < local_variable_table.length - 1) {
176 buf.append('\n');
177 }
178 }
179 return buf.toString();
180 }
181
182
183 /**
184 * @return deep copy of this attribute
185 */
186 @Override
187 public Attribute copy( final ConstantPool _constant_pool ) {
188 final LocalVariableTable c = (LocalVariableTable) clone();
189 c.local_variable_table = new LocalVariable[local_variable_table.length];
190 for (int i = 0; i < local_variable_table.length; i++) {
191 c.local_variable_table[i] = local_variable_table[i].copy();
192 }
193 c.setConstantPool(_constant_pool);
194 return c;
195 }
196
197
198 public final int getTableLength() {
199 return local_variable_table == null ? 0 : local_variable_table.length;
200 }
201 }