1 /*
2 * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.lang.model;
27
28 import java.util.Collections;
29 import java.util.Set;
30 import java.util.HashSet;
31
32 /**
33 * Source versions of the Java™ programming language.
34 *
35 * See the appropriate edition of
36 * <cite>The Java™ Language Specification</cite>
37 * for information about a particular source version.
38 *
39 * <p>Note that additional source version constants will be added to
40 * model future releases of the language.
41 *
42 * @author Joseph D. Darcy
43 * @author Scott Seligman
44 * @author Peter von der Ahé
45 * @since 1.6
46 */
47 public enum SourceVersion {
48 /*
49 * Summary of language evolution
50 * 1.1: nested classes
51 * 1.2: strictfp
52 * 1.3: no changes
53 * 1.4: assert
54 * 1.5: annotations, generics, autoboxing, var-args...
55 * 1.6: no changes
56 * 1.7: diamond syntax, try-with-resources, etc.
57 * 1.8: lambda expressions and default methods
58 * 9: modules, small cleanups to 1.7 and 1.8 changes
59 * 10: local-variable type inference (var)
60 * 11: local-variable syntax for lambda parameters
61 * 12: no changes (switch expressions in preview)
62 * 13: TBD
63 */
64
65 /**
66 * The original version.
67 *
68 * The language described in
69 * <cite>The Java™ Language Specification, First Edition</cite>.
70 */
71 RELEASE_0,
72
73 /**
74 * The version recognized by the Java Platform 1.1.
75 *
76 * The language is {@code RELEASE_0} augmented with nested classes as described in the 1.1 update to
77 * <cite>The Java™ Language Specification, First Edition</cite>.
78 */
79 RELEASE_1,
80
81 /**
82 * The version recognized by the Java 2 Platform, Standard Edition,
83 * v 1.2.
84 *
85 * The language described in
86 * <cite>The Java™ Language Specification,
87 * Second Edition</cite>, which includes the {@code
88 * strictfp} modifier.
89 */
90 RELEASE_2,
91
92 /**
93 * The version recognized by the Java 2 Platform, Standard Edition,
94 * v 1.3.
95 *
96 * No major changes from {@code RELEASE_2}.
97 */
98 RELEASE_3,
99
100 /**
101 * The version recognized by the Java 2 Platform, Standard Edition,
102 * v 1.4.
103 *
104 * Added a simple assertion facility.
105 */
106 RELEASE_4,
107
108 /**
109 * The version recognized by the Java 2 Platform, Standard
110 * Edition 5.0.
111 *
112 * The language described in
113 * <cite>The Java™ Language Specification,
114 * Third Edition</cite>. First release to support
115 * generics, annotations, autoboxing, var-args, enhanced {@code
116 * for} loop, and hexadecimal floating-point literals.
117 */
118 RELEASE_5,
119
120 /**
121 * The version recognized by the Java Platform, Standard Edition
122 * 6.
123 *
124 * No major changes from {@code RELEASE_5}.
125 */
126 RELEASE_6,
127
128 /**
129 * The version recognized by the Java Platform, Standard Edition
130 * 7.
131 *
132 * Additions in this release include, diamond syntax for
133 * constructors, {@code try}-with-resources, strings in switch,
134 * binary literals, and multi-catch.
135 * @since 1.7
136 */
137 RELEASE_7,
138
139 /**
140 * The version recognized by the Java Platform, Standard Edition
141 * 8.
142 *
143 * Additions in this release include lambda expressions and default methods.
144 * @since 1.8
145 */
146 RELEASE_8,
147
148 /**
149 * The version recognized by the Java Platform, Standard Edition
150 * 9.
151 *
152 * Additions in this release include modules and removal of a
153 * single underscore from the set of legal identifier names.
154 *
155 * @since 9
156 */
157 RELEASE_9,
158
159 /**
160 * The version recognized by the Java Platform, Standard Edition
161 * 10.
162 *
163 * Additions in this release include local-variable type inference
164 * ({@code var}).
165 *
166 * @since 10
167 */
168 RELEASE_10,
169
170 /**
171 * The version recognized by the Java Platform, Standard Edition
172 * 11.
173 *
174 * Additions in this release include local-variable syntax for
175 * lambda parameters.
176 *
177 * @since 11
178 */
179 RELEASE_11,
180
181 /**
182 * The version recognized by the Java Platform, Standard Edition
183 * 12.
184 *
185 * @since 12
186 */
187 RELEASE_12,
188
189 /**
190 * The version recognized by the Java Platform, Standard Edition
191 * 13.
192 *
193 * @since 13
194 */
195 RELEASE_13;
196
197 // Note that when adding constants for newer releases, the
198 // behavior of latest() and latestSupported() must be updated too.
199
200 /**
201 * Returns the latest source version that can be modeled.
202 *
203 * @return the latest source version that can be modeled
204 */
205 public static SourceVersion latest() {
206 return RELEASE_13;
207 }
208
209 private static final SourceVersion latestSupported = getLatestSupported();
210
211 /*
212 * The integer to release enum constant implemented by this method
213 * assumes the JEP 322: "Time-Based Release Versioning" scheme is
214 * in effect. This scheme began in JDK 10. If the JDK versioning
215 * scheme is revised, this method may need to be updated
216 * accordingly.
217 */
218 private static SourceVersion getLatestSupported() {
219 int intVersion = Runtime.version().feature();
220 return (intVersion >= 11) ?
221 valueOf("RELEASE_" + Math.min(13, intVersion)):
222 RELEASE_10;
223 }
224
225 /**
226 * Returns the latest source version fully supported by the
227 * current execution environment. {@code RELEASE_9} or later must
228 * be returned.
229 *
230 * @apiNote This method is included alongside {@link latest} to
231 * allow situations where the language model API is running on a
232 * platform version different than the latest version modeled by
233 * the API to be identified. One way that sort of situation can
234 * occur is if a IDE or similar tool is using the API to model
235 * source version <i>N</i> while running on platform version
236 * (<i>N</i> - 1). Running in this configuration is
237 * supported by the API. Running an API on platform versions
238 * earlier than (<i>N</i> - 1) or later than <i>N</i>
239 * may or may not work as an implementation detail.
240 *
241 * @return the latest source version that is fully supported
242 */
243 public static SourceVersion latestSupported() {
244 return latestSupported;
245 }
246
247 /**
248 * Returns whether or not {@code name} is a syntactically valid
249 * identifier (simple name) or keyword in the latest source
250 * version. The method returns {@code true} if the name consists
251 * of an initial character for which {@link
252 * Character#isJavaIdentifierStart(int)} returns {@code true},
253 * followed only by characters for which {@link
254 * Character#isJavaIdentifierPart(int)} returns {@code true}.
255 * This pattern matches regular identifiers, keywords, restricted
256 * keywords, and the literals {@code "true"}, {@code "false"},
257 * {@code "null"}, and {@code "var"}.
258 *
259 * The method returns {@code false} for all other strings.
260 *
261 * @param name the string to check
262 * @return {@code true} if this string is a
263 * syntactically valid identifier or keyword, {@code false}
264 * otherwise.
265 */
266 public static boolean isIdentifier(CharSequence name) {
267 String id = name.toString();
268
269 if (id.length() == 0) {
270 return false;
271 }
272 int cp = id.codePointAt(0);
273 if (!Character.isJavaIdentifierStart(cp)) {
274 return false;
275 }
276 for (int i = Character.charCount(cp);
277 i < id.length();
278 i += Character.charCount(cp)) {
279 cp = id.codePointAt(i);
280 if (!Character.isJavaIdentifierPart(cp)) {
281 return false;
282 }
283 }
284 return true;
285 }
286
287 /**
288 * Returns whether or not {@code name} is a syntactically valid
289 * qualified name in the latest source version. Unlike {@link
290 * #isIdentifier isIdentifier}, this method returns {@code false}
291 * for keywords, boolean literals, and the null literal.
292 *
293 * This method returns {@code true} for <i>restricted
294 * keywords</i> and {@code "var"}.
295 *
296 * @param name the string to check
297 * @return {@code true} if this string is a
298 * syntactically valid name, {@code false} otherwise.
299 * @jls 3.9 Keywords
300 * @jls 6.2 Names and Identifiers
301 */
302 public static boolean isName(CharSequence name) {
303 return isName(name, latest());
304 }
305
306 /**
307 * Returns whether or not {@code name} is a syntactically valid
308 * qualified name in the given source version. Unlike {@link
309 * #isIdentifier isIdentifier}, this method returns {@code false}
310 * for keywords, boolean literals, and the null literal.
311 *
312 * This method returns {@code true} for <i>restricted
313 * keywords</i> and {@code "var"}.
314 *
315 * @param name the string to check
316 * @param version the version to use
317 * @return {@code true} if this string is a
318 * syntactically valid name, {@code false} otherwise.
319 * @jls 3.9 Keywords
320 * @jls 6.2 Names and Identifiers
321 * @since 9
322 */
323 public static boolean isName(CharSequence name, SourceVersion version) {
324 String id = name.toString();
325
326 for(String s : id.split("\\.", -1)) {
327 if (!isIdentifier(s) || isKeyword(s, version))
328 return false;
329 }
330 return true;
331 }
332
333 /**
334 * Returns whether or not {@code s} is a keyword, boolean literal,
335 * or null literal in the latest source version.
336 * This method returns {@code false} for <i>restricted
337 * keywords</i> and {@code "var"}.
338 *
339 * @param s the string to check
340 * @return {@code true} if {@code s} is a keyword, or boolean
341 * literal, or null literal, {@code false} otherwise.
342 * @jls 3.9 Keywords
343 * @jls 3.10.3 Boolean Literals
344 * @jls 3.10.7 The Null Literal
345 */
346 public static boolean isKeyword(CharSequence s) {
347 return isKeyword(s, latest());
348 }
349
350 /**
351 * Returns whether or not {@code s} is a keyword, boolean literal,
352 * or null literal in the given source version.
353 * This method returns {@code false} for <i>restricted
354 * keywords</i> and {@code "var"}.
355 *
356 * @param s the string to check
357 * @param version the version to use
358 * @return {@code true} if {@code s} is a keyword, or boolean
359 * literal, or null literal, {@code false} otherwise.
360 * @jls 3.9 Keywords
361 * @jls 3.10.3 Boolean Literals
362 * @jls 3.10.7 The Null Literal
363 * @since 9
364 */
365 public static boolean isKeyword(CharSequence s, SourceVersion version) {
366 String id = s.toString();
367 switch(id) {
368 // A trip through history
369 case "strictfp":
370 return version.compareTo(RELEASE_2) >= 0;
371
372 case "assert":
373 return version.compareTo(RELEASE_4) >= 0;
374
375 case "enum":
376 return version.compareTo(RELEASE_5) >= 0;
377
378 case "_":
379 return version.compareTo(RELEASE_9) >= 0;
380
381 // Keywords common across versions
382
383 // Modifiers
384 case "public": case "protected": case "private":
385 case "abstract": case "static": case "final":
386 case "transient": case "volatile": case "synchronized":
387 case "native":
388
389 // Declarations
390 case "class": case "interface": case "extends":
391 case "package": case "throws": case "implements":
392
393 // Primitive types and void
394 case "boolean": case "byte": case "char":
395 case "short": case "int": case "long":
396 case "float": case "double":
397 case "void":
398
399 // Control flow
400 case "if": case "else":
401 case "try": case "catch": case "finally":
402 case "do": case "while":
403 case "for": case "continue":
404 case "switch": case "case": case "default":
405 case "break": case "throw": case "return":
406
407 // Other keywords
408 case "this": case "new": case "super":
409 case "import": case "instanceof":
410
411 // Forbidden!
412 case "goto": case "const":
413
414 // literals
415 case "null": case "true": case "false":
416 return true;
417
418 default:
419 return false;
420 }
421 }
422 }