1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 /*
26 * This file is available under and governed by the GNU General Public
27 * License version 2 only, as published by the Free Software Foundation.
28 * However, the following notice accompanied the original version of this
29 * file:
30 *
31 * ASM: a very small and fast Java bytecode manipulation framework
32 * Copyright (c) 2000-2011 INRIA, France Telecom
33 * All rights reserved.
34 *
35 * Redistribution and use in source and binary forms, with or without
36 * modification, are permitted provided that the following conditions
37 * are met:
38 * 1. Redistributions of source code must retain the above copyright
39 * notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 * notice, this list of conditions and the following disclaimer in the
42 * documentation and/or other materials provided with the distribution.
43 * 3. Neither the name of the copyright holders nor the names of its
44 * contributors may be used to endorse or promote products derived from
45 * this software without specific prior written permission.
46 *
47 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
48 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
51 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
52 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
53 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
54 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
55 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
56 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
57 * THE POSSIBILITY OF SUCH DAMAGE.
58 */
59 package jdk.internal.org.objectweb.asm;
60
61 /**
62 * A constant pool item. Constant pool items can be created with the 'newXXX'
63 * methods in the {@link ClassWriter} class.
64 *
65 * @author Eric Bruneton
66 */
67 final class Item {
68
69 /**
70 * Index of this item in the constant pool.
71 */
72 int index;
73
74 /**
75 * Type of this constant pool item. A single class is used to represent all
76 * constant pool item types, in order to minimize the bytecode size of this
77 * package. The value of this field is one of {@link ClassWriter#INT},
78 * {@link ClassWriter#LONG}, {@link ClassWriter#FLOAT},
79 * {@link ClassWriter#DOUBLE}, {@link ClassWriter#UTF8},
80 * {@link ClassWriter#STR}, {@link ClassWriter#CLASS},
81 * {@link ClassWriter#NAME_TYPE}, {@link ClassWriter#FIELD},
82 * {@link ClassWriter#METH}, {@link ClassWriter#IMETH},
83 * {@link ClassWriter#MTYPE}, {@link ClassWriter#INDY}.
84 *
85 * MethodHandle constant 9 variations are stored using a range of 9 values
86 * from {@link ClassWriter#HANDLE_BASE} + 1 to
87 * {@link ClassWriter#HANDLE_BASE} + 9.
88 *
89 * Special Item types are used for Items that are stored in the ClassWriter
90 * {@link ClassWriter#typeTable}, instead of the constant pool, in order to
91 * avoid clashes with normal constant pool items in the ClassWriter constant
92 * pool's hash table. These special item types are
93 * {@link ClassWriter#TYPE_NORMAL}, {@link ClassWriter#TYPE_UNINIT} and
94 * {@link ClassWriter#TYPE_MERGED}.
95 */
96 int type;
97
98 /**
99 * Value of this item, for an integer item.
100 */
101 int intVal;
102
103 /**
104 * Value of this item, for a long item.
105 */
106 long longVal;
107
108 /**
109 * First part of the value of this item, for items that do not hold a
110 * primitive value.
111 */
112 String strVal1;
113
114 /**
115 * Second part of the value of this item, for items that do not hold a
116 * primitive value.
117 */
118 String strVal2;
119
120 /**
121 * Third part of the value of this item, for items that do not hold a
122 * primitive value.
123 */
124 String strVal3;
125
126 /**
127 * The hash code value of this constant pool item.
128 */
129 int hashCode;
130
131 /**
132 * Link to another constant pool item, used for collision lists in the
133 * constant pool's hash table.
134 */
135 Item next;
136
137 /**
138 * Constructs an uninitialized {@link Item}.
139 */
140 Item() {
141 }
142
143 /**
144 * Constructs an uninitialized {@link Item} for constant pool element at
145 * given position.
146 *
147 * @param index
148 * index of the item to be constructed.
149 */
150 Item(final int index) {
151 this.index = index;
152 }
153
154 /**
155 * Constructs a copy of the given item.
156 *
157 * @param index
158 * index of the item to be constructed.
159 * @param i
160 * the item that must be copied into the item to be constructed.
161 */
162 Item(final int index, final Item i) {
163 this.index = index;
164 type = i.type;
165 intVal = i.intVal;
166 longVal = i.longVal;
167 strVal1 = i.strVal1;
168 strVal2 = i.strVal2;
169 strVal3 = i.strVal3;
170 hashCode = i.hashCode;
171 }
172
173 /**
174 * Sets this item to an integer item.
175 *
176 * @param intVal
177 * the value of this item.
178 */
179 void set(final int intVal) {
180 this.type = ClassWriter.INT;
181 this.intVal = intVal;
182 this.hashCode = 0x7FFFFFFF & (type + intVal);
183 }
184
185 /**
186 * Sets this item to a long item.
187 *
188 * @param longVal
189 * the value of this item.
190 */
191 void set(final long longVal) {
192 this.type = ClassWriter.LONG;
193 this.longVal = longVal;
194 this.hashCode = 0x7FFFFFFF & (type + (int) longVal);
195 }
196
197 /**
198 * Sets this item to a float item.
199 *
200 * @param floatVal
201 * the value of this item.
202 */
203 void set(final float floatVal) {
204 this.type = ClassWriter.FLOAT;
205 this.intVal = Float.floatToRawIntBits(floatVal);
206 this.hashCode = 0x7FFFFFFF & (type + (int) floatVal);
207 }
208
209 /**
210 * Sets this item to a double item.
211 *
212 * @param doubleVal
213 * the value of this item.
214 */
215 void set(final double doubleVal) {
216 this.type = ClassWriter.DOUBLE;
217 this.longVal = Double.doubleToRawLongBits(doubleVal);
218 this.hashCode = 0x7FFFFFFF & (type + (int) doubleVal);
219 }
220
221 /**
222 * Sets this item to an item that do not hold a primitive value.
223 *
224 * @param type
225 * the type of this item.
226 * @param strVal1
227 * first part of the value of this item.
228 * @param strVal2
229 * second part of the value of this item.
230 * @param strVal3
231 * third part of the value of this item.
232 */
233 @SuppressWarnings("fallthrough")
234 void set(final int type, final String strVal1, final String strVal2,
235 final String strVal3) {
236 this.type = type;
237 this.strVal1 = strVal1;
238 this.strVal2 = strVal2;
239 this.strVal3 = strVal3;
240 switch (type) {
241 case ClassWriter.CLASS:
242 case ClassWriter.MODULE:
243 case ClassWriter.PACKAGE:
244 this.intVal = 0; // intVal of a class must be zero, see visitInnerClass
245 case ClassWriter.UTF8:
246 case ClassWriter.STR:
247 case ClassWriter.MTYPE:
248 case ClassWriter.TYPE_NORMAL:
249 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode());
250 return;
251 case ClassWriter.NAME_TYPE: {
252 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()
253 * strVal2.hashCode());
254 return;
255 }
256 // ClassWriter.FIELD:
257 // ClassWriter.METH:
258 // ClassWriter.IMETH:
259 // ClassWriter.HANDLE_BASE + 1..9
260 default:
261 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()
262 * strVal2.hashCode() * strVal3.hashCode());
263 }
264 }
265
266 /**
267 * Sets the item to an InvokeDynamic item.
268 *
269 * @param name
270 * invokedynamic's name.
271 * @param desc
272 * invokedynamic's desc.
273 * @param bsmIndex
274 * zero based index into the class attribute BootrapMethods.
275 */
276 void set(String name, String desc, int bsmIndex) {
277 this.type = ClassWriter.INDY;
278 this.longVal = bsmIndex;
279 this.strVal1 = name;
280 this.strVal2 = desc;
281 this.hashCode = 0x7FFFFFFF & (ClassWriter.INDY + bsmIndex
282 * strVal1.hashCode() * strVal2.hashCode());
283 }
284
285 /**
286 * Sets the item to a BootstrapMethod item.
287 *
288 * @param position
289 * position in byte in the class attribute BootrapMethods.
290 * @param hashCode
291 * hashcode of the item. This hashcode is processed from the
292 * hashcode of the bootstrap method and the hashcode of all
293 * bootstrap arguments.
294 */
295 void set(int position, int hashCode) {
296 this.type = ClassWriter.BSM;
297 this.intVal = position;
298 this.hashCode = hashCode;
299 }
300
301 /**
302 * Indicates if the given item is equal to this one. <i>This method assumes
303 * that the two items have the same {@link #type}</i>.
304 *
305 * @param i
306 * the item to be compared to this one. Both items must have the
307 * same {@link #type}.
308 * @return <tt>true</tt> if the given item if equal to this one,
309 * <tt>false</tt> otherwise.
310 */
311 boolean isEqualTo(final Item i) {
312 switch (type) {
313 case ClassWriter.UTF8:
314 case ClassWriter.STR:
315 case ClassWriter.CLASS:
316 case ClassWriter.MODULE:
317 case ClassWriter.PACKAGE:
318 case ClassWriter.MTYPE:
319 case ClassWriter.TYPE_NORMAL:
320 return i.strVal1.equals(strVal1);
321 case ClassWriter.TYPE_MERGED:
322 case ClassWriter.LONG:
323 case ClassWriter.DOUBLE:
324 return i.longVal == longVal;
325 case ClassWriter.INT:
326 case ClassWriter.FLOAT:
327 return i.intVal == intVal;
328 case ClassWriter.TYPE_UNINIT:
329 return i.intVal == intVal && i.strVal1.equals(strVal1);
330 case ClassWriter.NAME_TYPE:
331 return i.strVal1.equals(strVal1) && i.strVal2.equals(strVal2);
332 case ClassWriter.INDY: {
333 return i.longVal == longVal && i.strVal1.equals(strVal1)
334 && i.strVal2.equals(strVal2);
335 }
336 // case ClassWriter.FIELD:
337 // case ClassWriter.METH:
338 // case ClassWriter.IMETH:
339 // case ClassWriter.HANDLE_BASE + 1..9
340 default:
341 return i.strVal1.equals(strVal1) && i.strVal2.equals(strVal2)
342 && i.strVal3.equals(strVal3);
343 }
344 }
345
346 }