1 /*
2 * Copyright (c) 1999, 2025, 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 com.sun.tools.javac.code;
27
28 import java.util.Collections;
29 import java.util.EnumSet;
30 import java.util.Map;
31 import java.util.Set;
32 import java.util.concurrent.ConcurrentHashMap;
33 import java.util.stream.Collectors;
34
35 import javax.lang.model.element.Modifier;
36
37 import com.sun.tools.javac.util.Assert;
38 import com.sun.tools.javac.util.StringUtils;
39
40 /** Access flags and other modifiers for Java classes and members.
41 *
42 * <p><b>This is NOT part of any supported API.
43 * If you write code that depends on this, you do so at your own risk.
44 * This code and its internal interfaces are subject to change or
45 * deletion without notice.</b>
46 */
47 public class Flags {
48
49 private Flags() {} // uninstantiable
50
51 public static String toString(long flags) {
52 StringBuilder buf = new StringBuilder();
53 String sep = "";
54 for (Flag flag : asFlagSet(flags)) {
55 buf.append(sep);
56 buf.append(flag);
57 sep = " ";
58 }
59 return buf.toString();
60 }
61
62 public static EnumSet<Flag> asFlagSet(long flags) {
63 EnumSet<Flag> flagSet = EnumSet.noneOf(Flag.class);
64 for (Flag flag : Flag.values()) {
65 if ((flags & flag.value) != 0) {
66 flagSet.add(flag);
67 flags &= ~flag.value;
68 }
69 }
70 Assert.check(flags == 0);
71 return flagSet;
72 }
73
74 /* Standard Java flags.
75 */
76 public static final int PUBLIC = 1;
77 public static final int PRIVATE = 1<<1;
78 public static final int PROTECTED = 1<<2;
79 public static final int STATIC = 1<<3;
80 public static final int FINAL = 1<<4;
81 public static final int SYNCHRONIZED = 1<<5;
82 public static final int VOLATILE = 1<<6;
83 public static final int TRANSIENT = 1<<7;
84 public static final int NATIVE = 1<<8;
85 public static final int INTERFACE = 1<<9;
86 public static final int ABSTRACT = 1<<10;
87 public static final int STRICTFP = 1<<11;
88
89 /* Flag that marks a symbol synthetic, added in classfile v49.0. */
90 public static final int SYNTHETIC = 1<<12;
91
92 /** Flag that marks attribute interfaces, added in classfile v49.0. */
93 public static final int ANNOTATION = 1<<13;
94
95 /** An enumeration type or an enumeration constant, added in
96 * classfile v49.0. */
97 public static final int ENUM = 1<<14;
98
99 /** Added in SE8, represents constructs implicitly declared in source. */
100 public static final int MANDATED = 1<<15;
101
102 public static final int StandardFlags = 0x0fff;
103
104 // Because the following access flags are overloaded with other
105 // bit positions, we translate them when reading and writing class
106 // files into unique bits positions: ACC_SYNTHETIC <-> SYNTHETIC,
107 // for example.
108 public static final int ACC_SUPER = 0x0020;
109 public static final int ACC_BRIDGE = 0x0040;
110 public static final int ACC_VARARGS = 0x0080;
111 public static final int ACC_MODULE = 0x8000;
112
113 /* ***************************************
114 * Internal compiler flags (no bits in the lower 16).
115 *****************************************/
116
117 /** Flag is set if symbol is deprecated. See also DEPRECATED_REMOVAL.
118 */
119 public static final int DEPRECATED = 1<<17;
120
121 /** Flag is set for a variable symbol if the variable's definition
122 * has an initializer part.
123 */
124 public static final int HASINIT = 1<<18;
125
126 /** Class is an implicitly declared top level class.
127 */
128 public static final int IMPLICIT_CLASS = 1<<19;
129
130 /** Flag is set for compiler-generated anonymous method symbols
131 * that `own' an initializer block.
132 */
133 public static final int BLOCK = 1<<20;
134
135 /** Flag is set for ClassSymbols that are being compiled from source.
136 */
137 public static final int FROM_SOURCE = 1<<21; //ClassSymbols
138
139 /** Flag is set for nested classes that do not access instance members
140 * or `this' of an outer class and therefore don't need to be passed
141 * a this$n reference. This value is currently set only for anonymous
142 * classes in superclass constructor calls.
143 * todo: use this value for optimizing away this$n parameters in
144 * other cases.
145 */
146 public static final int NOOUTERTHIS = 1<<22;
147
148 /** Flag is set for package symbols if a package has a member or
149 * directory and therefore exists.
150 */
151 public static final int EXISTS = 1<<23;
152
153 /** Flag is set for compiler-generated compound classes
154 * representing multiple variable bounds
155 */
156 public static final int COMPOUND = 1<<24;
157
158 /** Flag is set for class symbols if a class file was found for this class.
159 */
160 public static final int CLASS_SEEN = 1<<25;
161
162 /** Flag is set for class symbols if a source file was found for this
163 * class.
164 */
165 public static final int SOURCE_SEEN = 1<<26;
166
167 /* State flags (are reset during compilation).
168 */
169
170 /** Flag for class symbols is set and later re-set as a lock in
171 * Enter to detect cycles in the superclass/superinterface
172 * relations. Similarly for constructor call cycle detection in
173 * Attr.
174 */
175 public static final int LOCKED = 1<<27;
176
177 /** Flag for class symbols is set and later re-set to indicate that a class
178 * has been entered but has not yet been attributed.
179 */
180 public static final int UNATTRIBUTED = 1<<28;
181
182 /** Flag for synthesized default constructors of anonymous classes.
183 */
184 public static final int ANONCONSTR = 1<<29; //non-class members
185
186 /**
187 * Flag to indicate the superclasses of this ClassSymbol has been attributed.
188 */
189 public static final int SUPER_OWNER_ATTRIBUTED = 1<<29; //ClassSymbols
190
191 /** Flag for class symbols to indicate it has been checked and found
192 * acyclic.
193 */
194 public static final int ACYCLIC = 1<<30;
195
196 /** Flag that marks bridge methods.
197 */
198 public static final long BRIDGE = 1L<<31;
199
200 /** Flag that marks formal parameters.
201 */
202 public static final long PARAMETER = 1L<<33;
203
204 /** Flag that marks varargs methods.
205 */
206 public static final long VARARGS = 1L<<34;
207
208 /** Flag for annotation type symbols to indicate it has been
209 * checked and found acyclic.
210 */
211 public static final long ACYCLIC_ANN = 1L<<35;
212
213 /** Flag that marks a generated default constructor.
214 */
215 public static final long GENERATEDCONSTR = 1L<<36;
216
217 /** Flag that marks a hypothetical method that need not really be
218 * generated in the binary, but is present in the symbol table to
219 * simplify checking for erasure clashes - also used for 292 poly sig methods.
220 */
221 public static final long HYPOTHETICAL = 1L<<37;
222
223 /**
224 * Flag that marks an internal proprietary class.
225 */
226 public static final long PROPRIETARY = 1L<<38;
227
228 /**
229 * Flag that marks a multi-catch parameter.
230 */
231 public static final long UNION = 1L<<39;
232
233 /**
234 * Flags an erroneous TypeSymbol as viable for recovery.
235 * TypeSymbols only.
236 */
237 public static final long RECOVERABLE = 1L<<40;
238
239 /**
240 * Flag that marks an 'effectively final' local variable.
241 */
242 public static final long EFFECTIVELY_FINAL = 1L<<41;
243
244 /**
245 * Flag that marks non-override equivalent methods with the same signature,
246 * or a conflicting match binding (BindingSymbol).
247 */
248 public static final long CLASH = 1L<<42;
249
250 /**
251 * Flag that marks either a default method or an interface containing default methods.
252 */
253 public static final long DEFAULT = 1L<<43;
254
255 /**
256 * Flag that marks class as auxiliary, ie a non-public class following
257 * the public class in a source file, that could block implicit compilation.
258 */
259 public static final long AUXILIARY = 1L<<44;
260
261 /**
262 * Flag that marks that a symbol is not available in the current profile
263 */
264 public static final long NOT_IN_PROFILE = 1L<<45;
265
266 /**
267 * Flag that indicates that an override error has been detected by Check.
268 */
269 public static final long BAD_OVERRIDE = 1L<<45;
270
271 /**
272 * Flag that indicates a signature polymorphic method (292).
273 */
274 public static final long SIGNATURE_POLYMORPHIC = 1L<<46;
275
276 /**
277 * Flag that indicates that an inference variable is used in a 'throws' clause.
278 */
279 public static final long THROWS = 1L<<47;
280
281 /*
282 * Currently available: Bit 48.
283 */
284
285 /**
286 * Flag that marks a synthetic method body for a lambda expression
287 */
288 public static final long LAMBDA_METHOD = 1L<<49; //MethodSymbols only
289
290 /**
291 * Flag that marks a synthetic local capture field in a local/anon class
292 */
293 public static final long LOCAL_CAPTURE_FIELD = 1L<<49; //VarSymbols only
294
295 /**
296 * Flag to control recursion in TransTypes
297 */
298 public static final long TYPE_TRANSLATED = 1L<<50;
299
300 /**
301 * Flag to indicate class symbol is for module-info
302 */
303 public static final long MODULE = 1L<<51;
304
305 /**
306 * Flag to indicate the given ModuleSymbol is an automatic module.
307 */
308 public static final long AUTOMATIC_MODULE = 1L<<52; //ModuleSymbols only
309
310 /**
311 * Flag to indicate the given PackageSymbol contains any non-.java and non-.class resources.
312 */
313 public static final long HAS_RESOURCE = 1L<<52; //PackageSymbols only
314
315 /**
316 * Flag to indicate the given ParamSymbol has a user-friendly name filled.
317 */
318 public static final long NAME_FILLED = 1L<<52; //ParamSymbols only
319
320 /**
321 * Flag to indicate the given ModuleSymbol is a system module.
322 */
323 public static final long SYSTEM_MODULE = 1L<<53; //ModuleSymbols only
324
325 /**
326 * Flag to indicate the given ClassSymbol is a value based.
327 */
328 public static final long VALUE_BASED = 1L<<53; //ClassSymbols only
329
330 /**
331 * Flag to indicate the given symbol has a @Deprecated annotation.
332 */
333 public static final long DEPRECATED_ANNOTATION = 1L<<54;
334
335 /**
336 * Flag to indicate the given symbol has been deprecated and marked for removal.
337 */
338 public static final long DEPRECATED_REMOVAL = 1L<<55;
339
340 /**
341 * Flag to indicate the API element in question is for a preview API.
342 */
343 public static final long PREVIEW_API = 1L<<56; //any Symbol kind
344
345 /**
346 * Flag for synthesized default constructors of anonymous classes that have an enclosing expression.
347 */
348 public static final long ANONCONSTR_BASED = 1L<<57;
349
350 /**
351 * Flag that marks finalize block as body-only, should not be copied into catch clauses.
352 * Used to implement try-with-resources.
353 */
354 public static final long BODY_ONLY_FINALIZE = 1L<<17; //blocks only
355
356 /**
357 * Flag to indicate the API element in question is for a preview API.
358 */
359 public static final long PREVIEW_REFLECTIVE = 1L<<58; //any Symbol kind
360
361 /**
362 * Flag to indicate the given variable is a match binding variable.
363 */
364 public static final long MATCH_BINDING = 1L<<59;
365
366 /**
367 * A flag to indicate a match binding variable whose scope extends after the current statement.
368 */
369 public static final long MATCH_BINDING_TO_OUTER = 1L<<60;
370
371 /**
372 * Flag to indicate that a class is a record. The flag is also used to mark fields that are
373 * part of the state vector of a record and to mark the canonical constructor
374 */
375 public static final long RECORD = 1L<<61; // ClassSymbols, MethodSymbols and VarSymbols
376
377 /**
378 * Flag to mark a record constructor as a compact one
379 */
380 public static final long COMPACT_RECORD_CONSTRUCTOR = 1L<<51; // MethodSymbols only
381
382 /**
383 * Flag to mark a record field that was not initialized in the compact constructor
384 */
385 public static final long UNINITIALIZED_FIELD= 1L<<51; // VarSymbols only
386
387 /** Flag is set for compiler-generated record members, it could be applied to
388 * accessors and fields
389 */
390 public static final int GENERATED_MEMBER = 1<<24; // MethodSymbols and VarSymbols
391
392 /**
393 * Flag to indicate sealed class/interface declaration.
394 */
395 public static final long SEALED = 1L<<62; // ClassSymbols
396
397 /**
398 * Flag to indicate restricted method declaration.
399 */
400 public static final long RESTRICTED = 1L<<62; // MethodSymbols
401
402 /**
403 * Flag to indicate type annotations have been queued for field initializers.
404 */
405 public static final long FIELD_INIT_TYPE_ANNOTATIONS_QUEUED = 1L<<53; // VarSymbols
406
407 /**
408 * Flag to indicate that the class/interface was declared with the non-sealed modifier.
409 */
410 public static final long NON_SEALED = 1L<<63; // ClassSymbols
411
412 /**
413 * Describe modifier flags as they might appear in source code, i.e.,
414 * separated by spaces and in the order suggested by JLS 8.1.1.
415 */
416 public static String toSource(long flags) {
417 return asModifierSet(flags).stream()
418 .map(Modifier::toString)
419 .collect(Collectors.joining(" "));
420 }
421
422 /** Modifier masks.
423 */
424 public static final int
425 AccessFlags = PUBLIC | PROTECTED | PRIVATE,
426 LocalClassFlags = FINAL | ABSTRACT | STRICTFP | ENUM | SYNTHETIC,
427 StaticLocalFlags = LocalClassFlags | STATIC | INTERFACE,
428 MemberClassFlags = LocalClassFlags | INTERFACE | AccessFlags,
429 MemberStaticClassFlags = MemberClassFlags | STATIC,
430 ClassFlags = LocalClassFlags | INTERFACE | PUBLIC | ANNOTATION,
431 InterfaceVarFlags = FINAL | STATIC | PUBLIC,
432 VarFlags = AccessFlags | FINAL | STATIC |
433 VOLATILE | TRANSIENT | ENUM,
434 ConstructorFlags = AccessFlags,
435 InterfaceMethodFlags = ABSTRACT | PUBLIC,
436 MethodFlags = AccessFlags | ABSTRACT | STATIC | NATIVE |
437 SYNCHRONIZED | FINAL | STRICTFP,
438 RecordMethodFlags = AccessFlags | ABSTRACT | STATIC |
439 SYNCHRONIZED | FINAL | STRICTFP;
440 public static final long
441 ExtendedStandardFlags = (long)StandardFlags | DEFAULT | SEALED | NON_SEALED,
442 ExtendedMemberClassFlags = (long)MemberClassFlags | SEALED | NON_SEALED,
443 ExtendedMemberStaticClassFlags = (long) MemberStaticClassFlags | SEALED | NON_SEALED,
444 ExtendedClassFlags = (long)ClassFlags | SEALED | NON_SEALED,
445 ModifierFlags = ((long)StandardFlags & ~INTERFACE) | DEFAULT | SEALED | NON_SEALED,
446 InterfaceMethodMask = ABSTRACT | PRIVATE | STATIC | PUBLIC | STRICTFP | DEFAULT,
447 AnnotationTypeElementMask = ABSTRACT | PUBLIC,
448 LocalVarFlags = FINAL | PARAMETER,
449 ReceiverParamFlags = PARAMETER;
450
451 public static Set<Modifier> asModifierSet(long flags) {
452 Set<Modifier> modifiers = modifierSets.get(flags);
453 if (modifiers == null) {
454 modifiers = java.util.EnumSet.noneOf(Modifier.class);
455 if (0 != (flags & PUBLIC)) modifiers.add(Modifier.PUBLIC);
456 if (0 != (flags & PROTECTED)) modifiers.add(Modifier.PROTECTED);
457 if (0 != (flags & PRIVATE)) modifiers.add(Modifier.PRIVATE);
458 if (0 != (flags & ABSTRACT)) modifiers.add(Modifier.ABSTRACT);
459 if (0 != (flags & STATIC)) modifiers.add(Modifier.STATIC);
460 if (0 != (flags & SEALED)) modifiers.add(Modifier.SEALED);
461 if (0 != (flags & NON_SEALED))
462 modifiers.add(Modifier.NON_SEALED);
463 if (0 != (flags & FINAL)) modifiers.add(Modifier.FINAL);
464 if (0 != (flags & TRANSIENT)) modifiers.add(Modifier.TRANSIENT);
465 if (0 != (flags & VOLATILE)) modifiers.add(Modifier.VOLATILE);
466 if (0 != (flags & SYNCHRONIZED))
467 modifiers.add(Modifier.SYNCHRONIZED);
468 if (0 != (flags & NATIVE)) modifiers.add(Modifier.NATIVE);
469 if (0 != (flags & STRICTFP)) modifiers.add(Modifier.STRICTFP);
470 if (0 != (flags & DEFAULT)) modifiers.add(Modifier.DEFAULT);
471 modifiers = Collections.unmodifiableSet(modifiers);
472 modifierSets.put(flags, modifiers);
473 }
474 return modifiers;
475 }
476
477 // Cache of modifier sets.
478 private static final Map<Long, Set<Modifier>> modifierSets = new ConcurrentHashMap<>(64);
479
480 public static boolean isStatic(Symbol symbol) {
481 return (symbol.flags() & STATIC) != 0;
482 }
483
484 public static boolean isEnum(Symbol symbol) {
485 return (symbol.flags() & ENUM) != 0;
486 }
487
488 public static boolean isConstant(Symbol.VarSymbol symbol) {
489 return symbol.getConstValue() != null;
490 }
491
492
493 public enum Flag {
494 PUBLIC(Flags.PUBLIC),
495 PRIVATE(Flags.PRIVATE),
496 PROTECTED(Flags.PROTECTED),
497 STATIC(Flags.STATIC),
498 FINAL(Flags.FINAL),
499 SYNCHRONIZED(Flags.SYNCHRONIZED),
500 VOLATILE(Flags.VOLATILE),
501 TRANSIENT(Flags.TRANSIENT),
502 NATIVE(Flags.NATIVE),
503 INTERFACE(Flags.INTERFACE),
504 ABSTRACT(Flags.ABSTRACT),
505 DEFAULT(Flags.DEFAULT),
506 STRICTFP(Flags.STRICTFP),
507 BRIDGE(Flags.BRIDGE),
508 SYNTHETIC(Flags.SYNTHETIC),
509 ANNOTATION(Flags.ANNOTATION),
510 DEPRECATED(Flags.DEPRECATED),
511 HASINIT(Flags.HASINIT),
512 IMPLICIT_CLASS(Flags.IMPLICIT_CLASS),
513 BLOCK(Flags.BLOCK),
514 FROM_SOURCE(Flags.FROM_SOURCE),
515 ENUM(Flags.ENUM),
516 MANDATED(Flags.MANDATED),
517 NOOUTERTHIS(Flags.NOOUTERTHIS),
518 EXISTS(Flags.EXISTS),
519 COMPOUND(Flags.COMPOUND),
520 CLASS_SEEN(Flags.CLASS_SEEN),
521 SOURCE_SEEN(Flags.SOURCE_SEEN),
522 LOCKED(Flags.LOCKED),
523 UNATTRIBUTED(Flags.UNATTRIBUTED),
524 ANONCONSTR(Flags.ANONCONSTR),
525 ACYCLIC(Flags.ACYCLIC),
526 PARAMETER(Flags.PARAMETER),
527 VARARGS(Flags.VARARGS),
528 ACYCLIC_ANN(Flags.ACYCLIC_ANN),
529 GENERATEDCONSTR(Flags.GENERATEDCONSTR),
530 HYPOTHETICAL(Flags.HYPOTHETICAL),
531 PROPRIETARY(Flags.PROPRIETARY),
532 UNION(Flags.UNION),
533 EFFECTIVELY_FINAL(Flags.EFFECTIVELY_FINAL),
534 CLASH(Flags.CLASH),
535 AUXILIARY(Flags.AUXILIARY),
536 NOT_IN_PROFILE(Flags.NOT_IN_PROFILE),
537 BAD_OVERRIDE(Flags.BAD_OVERRIDE),
538 SIGNATURE_POLYMORPHIC(Flags.SIGNATURE_POLYMORPHIC),
539 THROWS(Flags.THROWS),
540 LAMBDA_METHOD(Flags.LAMBDA_METHOD),
541 TYPE_TRANSLATED(Flags.TYPE_TRANSLATED),
542 MODULE(Flags.MODULE),
543 AUTOMATIC_MODULE(Flags.AUTOMATIC_MODULE),
544 SYSTEM_MODULE(Flags.SYSTEM_MODULE),
545 DEPRECATED_ANNOTATION(Flags.DEPRECATED_ANNOTATION),
546 DEPRECATED_REMOVAL(Flags.DEPRECATED_REMOVAL),
547 HAS_RESOURCE(Flags.HAS_RESOURCE),
548 // Bit 48 is currently available
549 ANONCONSTR_BASED(Flags.ANONCONSTR_BASED),
550 NAME_FILLED(Flags.NAME_FILLED),
551 PREVIEW_API(Flags.PREVIEW_API),
552 PREVIEW_REFLECTIVE(Flags.PREVIEW_REFLECTIVE),
553 MATCH_BINDING(Flags.MATCH_BINDING),
554 MATCH_BINDING_TO_OUTER(Flags.MATCH_BINDING_TO_OUTER),
555 RECORD(Flags.RECORD),
556 RECOVERABLE(Flags.RECOVERABLE),
557 SEALED(Flags.SEALED),
558 NON_SEALED(Flags.NON_SEALED) {
559 @Override
560 public String toString() {
561 return "non-sealed";
562 }
563 };
564
565 Flag(long flag) {
566 this.value = flag;
567 this.lowercaseName = StringUtils.toLowerCase(name());
568 }
569
570 @Override
571 public String toString() {
572 return lowercaseName;
573 }
574
575 final long value;
576 final String lowercaseName;
577 }
578
579 }