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: TBD
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 private static SourceVersion getLatestSupported() {
212 try {
213 String specVersion = System.getProperty("java.specification.version");
214
215 switch (specVersion) {
216 case "13":
217 return RELEASE_13;
218 case "12":
219 return RELEASE_12;
220 case "11":
221 return RELEASE_11;
222 case "10":
223 return RELEASE_10;
224 case "9":
225 return RELEASE_9;
226 case "1.8":
227 return RELEASE_8;
228 case "1.7":
229 return RELEASE_7;
230 case "1.6":
231 return RELEASE_6;
232 }
233 } catch (SecurityException se) {}
234
235 return RELEASE_5;
236 }
237
238 /**
239 * Returns the latest source version fully supported by the
240 * current execution environment. {@code RELEASE_5} or later must
241 * be returned.
242 *
243 * @return the latest source version that is fully supported
244 */
245 public static SourceVersion latestSupported() {
246 return latestSupported;
247 }
248
249 /**
250 * Returns whether or not {@code name} is a syntactically valid
251 * identifier (simple name) or keyword in the latest source
252 * version. The method returns {@code true} if the name consists
253 * of an initial character for which {@link
254 * Character#isJavaIdentifierStart(int)} returns {@code true},
255 * followed only by characters for which {@link
256 * Character#isJavaIdentifierPart(int)} returns {@code true}.
257 * This pattern matches regular identifiers, keywords, restricted
258 * keywords, and the literals {@code "true"}, {@code "false"},
259 * {@code "null"}, and {@code "var"}.
260 *
261 * The method returns {@code false} for all other strings.
262 *
263 * @param name the string to check
264 * @return {@code true} if this string is a
265 * syntactically valid identifier or keyword, {@code false}
266 * otherwise.
267 */
268 public static boolean isIdentifier(CharSequence name) {
269 String id = name.toString();
270
271 if (id.length() == 0) {
272 return false;
273 }
274 int cp = id.codePointAt(0);
275 if (!Character.isJavaIdentifierStart(cp)) {
276 return false;
277 }
278 for (int i = Character.charCount(cp);
279 i < id.length();
280 i += Character.charCount(cp)) {
281 cp = id.codePointAt(i);
282 if (!Character.isJavaIdentifierPart(cp)) {
283 return false;
284 }
285 }
286 return true;
287 }
288
289 /**
290 * Returns whether or not {@code name} is a syntactically valid
291 * qualified name in the latest source version. Unlike {@link
292 * #isIdentifier isIdentifier}, this method returns {@code false}
293 * for keywords, boolean literals, and the null literal.
294 *
295 * This method returns {@code true} for <i>restricted
296 * keywords</i> and {@code "var"}.
297 *
298 * @param name the string to check
299 * @return {@code true} if this string is a
300 * syntactically valid name, {@code false} otherwise.
301 * @jls 3.9 Keywords
302 * @jls 6.2 Names and Identifiers
303 */
304 public static boolean isName(CharSequence name) {
305 return isName(name, latest());
306 }
307
308 /**
309 * Returns whether or not {@code name} is a syntactically valid
310 * qualified name in the given source version. Unlike {@link
311 * #isIdentifier isIdentifier}, this method returns {@code false}
312 * for keywords, boolean literals, and the null literal.
313 *
314 * This method returns {@code true} for <i>restricted
315 * keywords</i> and {@code "var"}.
316 *
317 * @param name the string to check
318 * @param version the version to use
319 * @return {@code true} if this string is a
320 * syntactically valid name, {@code false} otherwise.
321 * @jls 3.9 Keywords
322 * @jls 6.2 Names and Identifiers
323 * @since 9
324 */
325 public static boolean isName(CharSequence name, SourceVersion version) {
326 String id = name.toString();
327
328 for(String s : id.split("\\.", -1)) {
329 if (!isIdentifier(s) || isKeyword(s, version))
330 return false;
331 }
332 return true;
333 }
334
335 /**
336 * Returns whether or not {@code s} is a keyword, boolean literal,
337 * or null literal in the latest source version.
338 * This method returns {@code false} for <i>restricted
339 * keywords</i> and {@code "var"}.
340 *
341 * @param s the string to check
342 * @return {@code true} if {@code s} is a keyword, or boolean
343 * literal, or null literal, {@code false} otherwise.
344 * @jls 3.9 Keywords
345 * @jls 3.10.3 Boolean Literals
346 * @jls 3.10.7 The Null Literal
347 */
348 public static boolean isKeyword(CharSequence s) {
349 return isKeyword(s, latest());
350 }
351
352 /**
353 * Returns whether or not {@code s} is a keyword, boolean literal,
354 * or null literal in the given source version.
355 * This method returns {@code false} for <i>restricted
356 * keywords</i> and {@code "var"}.
357 *
358 * @param s the string to check
359 * @param version the version to use
360 * @return {@code true} if {@code s} is a keyword, or boolean
361 * literal, or null literal, {@code false} otherwise.
362 * @jls 3.9 Keywords
363 * @jls 3.10.3 Boolean Literals
364 * @jls 3.10.7 The Null Literal
365 * @since 9
366 */
367 public static boolean isKeyword(CharSequence s, SourceVersion version) {
368 String id = s.toString();
369 switch(id) {
370 // A trip through history
371 case "strictfp":
372 return version.compareTo(RELEASE_2) >= 0;
373
374 case "assert":
375 return version.compareTo(RELEASE_4) >= 0;
376
377 case "enum":
378 return version.compareTo(RELEASE_5) >= 0;
379
380 case "_":
381 return version.compareTo(RELEASE_9) >= 0;
382
383 // Keywords common across versions
384
385 // Modifiers
386 case "public": case "protected": case "private":
387 case "abstract": case "static": case "final":
388 case "transient": case "volatile": case "synchronized":
389 case "native":
390
391 // Declarations
392 case "class": case "interface": case "extends":
393 case "package": case "throws": case "implements":
394
395 // Primitive types and void
396 case "boolean": case "byte": case "char":
397 case "short": case "int": case "long":
398 case "float": case "double":
399 case "void":
400
401 // Control flow
402 case "if": case "else":
403 case "try": case "catch": case "finally":
404 case "do": case "while":
405 case "for": case "continue":
406 case "switch": case "case": case "default":
407 case "break": case "throw": case "return":
408
409 // Other keywords
410 case "this": case "new": case "super":
411 case "import": case "instanceof":
412
413 // Forbidden!
414 case "goto": case "const":
415
416 // literals
417 case "null": case "true": case "false":
418 return true;
419
420 default:
421 return false;
422 }
423 }
424 }