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#MODULE}, {@link ClassWriter#PACKAGE},
84 * {@link ClassWriter#MTYPE}, {@link ClassWriter#INDY}.
85 *
86 * MethodHandle constant 9 variations are stored using a range of 9 values
87 * from {@link ClassWriter#HANDLE_BASE} + 1 to
88 * {@link ClassWriter#HANDLE_BASE} + 9.
89 *
90 * Special Item types are used for Items that are stored in the ClassWriter
91 * {@link ClassWriter#typeTable}, instead of the constant pool, in order to
92 * avoid clashes with normal constant pool items in the ClassWriter constant
93 * pool's hash table. These special item types are
94 * {@link ClassWriter#TYPE_NORMAL}, {@link ClassWriter#TYPE_UNINIT} and
95 * {@link ClassWriter#TYPE_MERGED}.
96 */
97 int type;
98
99 /**
100 * Value of this item, for an integer item.
101 */
102 int intVal;
103
104 /**
105 * Value of this item, for a long item.
106 */
107 long longVal;
108
109 /**
110 * First part of the value of this item, for items that do not hold a
111 * primitive value.
112 */
113 String strVal1;
114
115 /**
116 * Second part of the value of this item, for items that do not hold a
117 * primitive value.
118 */
119 String strVal2;
120
121 /**
122 * Third part of the value of this item, for items that do not hold a
123 * primitive value.
124 */
125 String strVal3;
126
127 /**
128 * The hash code value of this constant pool item.
129 */
130 int hashCode;
131
132 /**
133 * Link to another constant pool item, used for collision lists in the
134 * constant pool's hash table.
135 */
136 Item next;
137
138 /**
139 * Constructs an uninitialized {@link Item}.
140 */
141 Item() {
142 }
143
144 /**
145 * Constructs an uninitialized {@link Item} for constant pool element at
146 * given position.
147 *
148 * @param index
149 * index of the item to be constructed.
150 */
151 Item(final int index) {
152 this.index = index;
153 }
154
155 /**
156 * Constructs a copy of the given item.
157 *
158 * @param index
159 * index of the item to be constructed.
160 * @param i
161 * the item that must be copied into the item to be constructed.
162 */
163 Item(final int index, final Item i) {
164 this.index = index;
165 type = i.type;
166 intVal = i.intVal;
167 longVal = i.longVal;
168 strVal1 = i.strVal1;
169 strVal2 = i.strVal2;
170 strVal3 = i.strVal3;
171 hashCode = i.hashCode;
172 }
173
174 /**
175 * Sets this item to an integer item.
176 *
177 * @param intVal
178 * the value of this item.
179 */
180 void set(final int intVal) {
181 this.type = ClassWriter.INT;
182 this.intVal = intVal;
183 this.hashCode = 0x7FFFFFFF & (type + intVal);
184 }
185
186 /**
187 * Sets this item to a long item.
188 *
189 * @param longVal
190 * the value of this item.
191 */
192 void set(final long longVal) {
193 this.type = ClassWriter.LONG;
194 this.longVal = longVal;
195 this.hashCode = 0x7FFFFFFF & (type + (int) longVal);
196 }
197
198 /**
199 * Sets this item to a float item.
200 *
201 * @param floatVal
202 * the value of this item.
203 */
204 void set(final float floatVal) {
205 this.type = ClassWriter.FLOAT;
206 this.intVal = Float.floatToRawIntBits(floatVal);
207 this.hashCode = 0x7FFFFFFF & (type + (int) floatVal);
208 }
209
210 /**
211 * Sets this item to a double item.
212 *
213 * @param doubleVal
214 * the value of this item.
215 */
216 void set(final double doubleVal) {
217 this.type = ClassWriter.DOUBLE;
218 this.longVal = Double.doubleToRawLongBits(doubleVal);
219 this.hashCode = 0x7FFFFFFF & (type + (int) doubleVal);
220 }
221
222 /**
223 * Sets this item to an item that do not hold a primitive value.
224 *
225 * @param type
226 * the type of this item.
227 * @param strVal1
228 * first part of the value of this item.
229 * @param strVal2
230 * second part of the value of this item.
231 * @param strVal3
232 * third part of the value of this item.
233 */
234 @SuppressWarnings("fallthrough")
235 void set(final int type, final String strVal1, final String strVal2,
236 final String strVal3) {
237 this.type = type;
238 this.strVal1 = strVal1;
239 this.strVal2 = strVal2;
240 this.strVal3 = strVal3;
241 switch (type) {
242 case ClassWriter.CLASS:
243 this.intVal = 0; // intVal of a class must be zero, see visitInnerClass
244 case ClassWriter.UTF8:
245 case ClassWriter.STR:
246 case ClassWriter.MTYPE:
247 case ClassWriter.MODULE:
248 case ClassWriter.PACKAGE:
249 case ClassWriter.TYPE_NORMAL:
250 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode());
251 return;
252 case ClassWriter.NAME_TYPE: {
253 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()
254 * strVal2.hashCode());
255 return;
256 }
257 // ClassWriter.FIELD:
258 // ClassWriter.METH:
259 // ClassWriter.IMETH:
260 // ClassWriter.HANDLE_BASE + 1..9
261 default:
262 hashCode = 0x7FFFFFFF & (type + strVal1.hashCode()
263 * strVal2.hashCode() * strVal3.hashCode());
264 }
265 }
266
267 /**
268 * Sets the item to an InvokeDynamic item.
269 *
270 * @param name
271 * invokedynamic's name.
272 * @param desc
273 * invokedynamic's desc.
274 * @param bsmIndex
275 * zero based index into the class attribute BootrapMethods.
276 */
277 void set(String name, String desc, int bsmIndex) {
278 this.type = ClassWriter.INDY;
279 this.longVal = bsmIndex;
280 this.strVal1 = name;
281 this.strVal2 = desc;
282 this.hashCode = 0x7FFFFFFF & (ClassWriter.INDY + bsmIndex
283 * strVal1.hashCode() * strVal2.hashCode());
284 }
285
286 /**
287 * Sets the item to a BootstrapMethod item.
288 *
289 * @param position
290 * position in byte in the class attribute BootrapMethods.
291 * @param hashCode
292 * hashcode of the item. This hashcode is processed from the
293 * hashcode of the bootstrap method and the hashcode of all
294 * bootstrap arguments.
295 */
296 void set(int position, int hashCode) {
297 this.type = ClassWriter.BSM;
298 this.intVal = position;
299 this.hashCode = hashCode;
300 }
301
302 /**
303 * Indicates if the given item is equal to this one. <i>This method assumes
304 * that the two items have the same {@link #type}</i>.
305 *
306 * @param i
307 * the item to be compared to this one. Both items must have the
308 * same {@link #type}.
309 * @return <tt>true</tt> if the given item if equal to this one,
310 * <tt>false</tt> otherwise.
311 */
312 boolean isEqualTo(final Item i) {
313 switch (type) {
314 case ClassWriter.UTF8:
315 case ClassWriter.STR:
316 case ClassWriter.CLASS:
317 case ClassWriter.MODULE:
318 case ClassWriter.PACKAGE:
319 case ClassWriter.MTYPE:
320 case ClassWriter.TYPE_NORMAL:
321 return i.strVal1.equals(strVal1);
322 case ClassWriter.TYPE_MERGED:
323 case ClassWriter.LONG:
324 case ClassWriter.DOUBLE:
325 return i.longVal == longVal;
326 case ClassWriter.INT:
327 case ClassWriter.FLOAT:
328 return i.intVal == intVal;
329 case ClassWriter.TYPE_UNINIT:
330 return i.intVal == intVal && i.strVal1.equals(strVal1);
331 case ClassWriter.NAME_TYPE:
332 return i.strVal1.equals(strVal1) && i.strVal2.equals(strVal2);
333 case ClassWriter.INDY: {
334 return i.longVal == longVal && i.strVal1.equals(strVal1)
335 && i.strVal2.equals(strVal2);
336 }
337 // case ClassWriter.FIELD:
338 // case ClassWriter.METH:
339 // case ClassWriter.IMETH:
340 // case ClassWriter.HANDLE_BASE + 1..9
341 default:
342 return i.strVal1.equals(strVal1) && i.strVal2.equals(strVal2)
343 && i.strVal3.equals(strVal3);
344 }
345 }
346
347 }