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 a stack map attribute used for
32 * preverification of Java classes for the <a
33 * href="http://java.sun.com/j2me/"> Java 2 Micro Edition</a>
34 * (J2ME). This attribute is used by the <a
35 * href="http://java.sun.com/products/cldc/">KVM</a> and contained
36 * within the Code attribute of a method. See CLDC specification
37 * 5.3.1.2
38 *
39 * @version $Id$
40 * @see Code
41 * @see StackMapEntry
42 * @see StackMapType
43 */
44 public final class StackMap extends Attribute {
45
46 private StackMapEntry[] map; // Table of stack map entries
47
48
49 /*
50 * @param name_index Index of name
51 * @param length Content length in bytes
52 * @param map Table of stack map entries
53 * @param constant_pool Array of constants
54 */
55 public StackMap(final int name_index, final int length, final StackMapEntry[] map, final ConstantPool constant_pool) {
56 super(Const.ATTR_STACK_MAP, name_index, length, constant_pool);
57 this.map = map;
58 }
59
60
61 /**
62 * Construct object from input stream.
63 *
64 * @param name_index Index of name
65 * @param length Content length in bytes
66 * @param input Input stream
67 * @param constant_pool Array of constants
68 * @throws IOException
69 */
70 StackMap(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) throws IOException {
71 this(name_index, length, (StackMapEntry[]) null, constant_pool);
72 final int map_length = input.readUnsignedShort();
73 map = new StackMapEntry[map_length];
74 for (int i = 0; i < map_length; i++) {
75 map[i] = new StackMapEntry(input, constant_pool);
76 }
77 }
78
79
80 /**
81 * Dump stack map table attribute to file stream in binary format.
82 *
83 * @param file Output file stream
84 * @throws IOException
85 */
86 @Override
87 public final void dump( final DataOutputStream file ) throws IOException {
88 super.dump(file);
89 file.writeShort(map.length);
90 for (final StackMapEntry entry : map) {
91 entry.dump(file);
92 }
93 }
94
95
96 /**
97 * @return Array of stack map entries
98 */
99 public final StackMapEntry[] getStackMap() {
100 return map;
101 }
102
103
104 /**
105 * @param map Array of stack map entries
106 */
107 public final void setStackMap( final StackMapEntry[] map ) {
108 this.map = map;
109 int len = 2; // Length of 'number_of_entries' field prior to the array of stack maps
110 for (final StackMapEntry element : map) {
111 len += element.getMapEntrySize();
112 }
113 setLength(len);
114 }
115
116
117 /**
118 * @return String representation.
119 */
120 @Override
121 public final String toString() {
122 final StringBuilder buf = new StringBuilder("StackMap(");
123 for (int i = 0; i < map.length; i++) {
124 buf.append(map[i]);
125 if (i < map.length - 1) {
126 buf.append(", ");
127 }
128 }
129 buf.append(')');
130 return buf.toString();
131 }
132
133
134 /**
135 * @return deep copy of this attribute
136 */
137 @Override
138 public Attribute copy( final ConstantPool _constant_pool ) {
139 final StackMap c = (StackMap) clone();
140 c.map = new StackMapEntry[map.length];
141 for (int i = 0; i < map.length; i++) {
142 c.map[i] = map[i].copy();
143 }
144 c.setConstantPool(_constant_pool);
145 return c;
146 }
147
148
149 /**
150 * Called by objects that are traversing the nodes of the tree implicitely
151 * defined by the contents of a Java class. I.e., the hierarchy of methods,
152 * fields, attributes, etc. spawns a tree of objects.
153 *
154 * @param v Visitor object
155 */
156 @Override
157 public void accept( final Visitor v ) {
158 v.visitStackMap(this);
159 }
160
161
162 public final int getMapLength() {
163 return map == null ? 0 : map.length;
164 }
165 }