1 /*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5 package com.sun.org.apache.bcel.internal.classfile;
6
7 /* ====================================================================
8 * The Apache Software License, Version 1.1
9 *
10 * Copyright (c) 2001 The Apache Software Foundation. All rights
11 * reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 *
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 *
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in
22 * the documentation and/or other materials provided with the
23 * distribution.
24 *
25 * 3. The end-user documentation included with the redistribution,
26 * if any, must include the following acknowledgment:
27 * "This product includes software developed by the
28 * Apache Software Foundation (http://www.apache.org/)."
29 * Alternately, this acknowledgment may appear in the software itself,
30 * if and wherever such third-party acknowledgments normally appear.
31 *
32 * 4. The names "Apache" and "Apache Software Foundation" and
33 * "Apache BCEL" must not be used to endorse or promote products
34 * derived from this software without prior written permission. For
35 * written permission, please contact apache@apache.org.
36 *
37 * 5. Products derived from this software may not be called "Apache",
38 * "Apache BCEL", nor may "Apache" appear in their name, without
39 * prior written permission of the Apache Software Foundation.
40 *
41 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
42 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 * ====================================================================
54 *
55 * This software consists of voluntary contributions made by many
56 * individuals on behalf of the Apache Software Foundation. For more
57 * information on the Apache Software Foundation, please see
58 * <http://www.apache.org/>.
59 */
60
61 import com.sun.org.apache.bcel.internal.Constants;
62 import java.io.*;
63
64 /**
65 * This class represents the type of a local variable or item on stack
66 * used in the StackMap entries.
67 *
68 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
69 * @see StackMapEntry
70 * @see StackMap
71 * @see Constants
72 */
73 public final class StackMapType implements Cloneable {
74 private byte type;
75 private int index = -1; // Index to CONSTANT_Class or offset
76 private ConstantPool constant_pool;
77
78 /**
79 * Construct object from file stream.
80 * @param file Input stream
81 * @throws IOException
82 */
83 StackMapType(DataInputStream file, ConstantPool constant_pool) throws IOException
84 {
85 this(file.readByte(), -1, constant_pool);
86
87 if(hasIndex())
88 setIndex(file.readShort());
89
90 setConstantPool(constant_pool);
91 }
92
93 /**
94 * @param type type tag as defined in the Constants interface
95 * @param index index to constant pool, or byte code offset
96 */
97 public StackMapType(byte type, int index, ConstantPool constant_pool) {
98 setType(type);
99 setIndex(index);
100 setConstantPool(constant_pool);
101 }
102
103 public void setType(byte t) {
104 if((t < Constants.ITEM_Bogus) || (t > Constants.ITEM_NewObject))
105 throw new RuntimeException("Illegal type for StackMapType: " + t);
106 type = t;
107 }
108
109 public byte getType() { return type; }
110 public void setIndex(int t) { index = t; }
111
112 /** @return index to constant pool if type == ITEM_Object, or offset
113 * in byte code, if type == ITEM_NewObject, and -1 otherwise
114 */
115 public int getIndex() { return index; }
116
117 /**
118 * Dump type entries to file.
119 *
120 * @param file Output file stream
121 * @throws IOException
122 */
123 public final void dump(DataOutputStream file) throws IOException
124 {
125 file.writeByte(type);
126 if(hasIndex())
127 file.writeShort(getIndex());
128 }
129
130 /** @return true, if type is either ITEM_Object or ITEM_NewObject
131 */
132 public final boolean hasIndex() {
133 return ((type == Constants.ITEM_Object) ||
134 (type == Constants.ITEM_NewObject));
135 }
136
137 private String printIndex() {
138 if(type == Constants.ITEM_Object)
139 return ", class=" + constant_pool.constantToString(index, Constants.CONSTANT_Class);
140 else if(type == Constants.ITEM_NewObject)
141 return ", offset=" + index;
142 else
143 return "";
144 }
145
146 /**
147 * @return String representation
148 */
149 public final String toString() {
150 return "(type=" + Constants.ITEM_NAMES[type] + printIndex() + ")";
151 }
152
153 /**
154 * @return deep copy of this object
155 */
156 public StackMapType copy() {
157 try {
158 return (StackMapType)clone();
159 } catch(CloneNotSupportedException e) {}
160
161 return null;
162 }
163
164 /**
165 * @return Constant pool used by this object.
166 */
167 public final ConstantPool getConstantPool() { return constant_pool; }
168
169 /**
170 * @param constant_pool Constant pool to be used for this object.
171 */
172 public final void setConstantPool(ConstantPool constant_pool) {
173 this.constant_pool = constant_pool;
174 }
175 }