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_IDENTITY = 0x0020;
109 public static final int ACC_BRIDGE = 0x0040;
110 public static final int ACC_VARARGS = 0x0080;
111 public static final int ACC_STRICT = 0x0800;
112 public static final int ACC_MODULE = 0x8000;
113
114 /* ***************************************
115 * Internal compiler flags (no bits in the lower 16).
116 *****************************************/
117
118 /** Flag is set if symbol is deprecated. See also DEPRECATED_REMOVAL.
119 */
120 public static final int DEPRECATED = 1<<17;
121
122 /** Flag is set for a variable symbol if the variable's definition
123 * has an initializer part.
124 */
125 public static final int HASINIT = 1<<18;
126
127 /** Flag is set for a class or interface whose instances have identity
128 * i.e. any concrete class not declared with the modifier `value'
129 * (a) abstract class not declared `value'
130 * (b) older class files with ACC_SUPER bit set
131 */
132 public static final int IDENTITY_TYPE = 1<<19;
133
134 /** Class is an implicitly declared top level class.
135 */
136 public static final int IMPLICIT_CLASS = 1<<23;
137
138 /** Flag is set for compiler-generated anonymous method symbols
139 * that `own' an initializer block.
140 */
141 public static final int BLOCK = 1<<20;
142
143 /** Marks a type as a value class */
144 public static final int VALUE_CLASS = 1<<20;
145
146 /** Flag is set for ClassSymbols that are being compiled from source.
147 */
148 public static final int FROM_SOURCE = 1<<21; //ClassSymbols
149
150 /** Flag is set for nested classes that do not access instance members
151 * or `this' of an outer class and therefore don't need to be passed
152 * a this$n reference. This value is currently set only for anonymous
153 * classes in superclass constructor calls.
154 * todo: use this value for optimizing away this$n parameters in
155 * other cases.
156 */
157 public static final int NOOUTERTHIS = 1<<22;
158
159 /** Flag is set for package symbols if a package has a member or
160 * directory and therefore exists.
161 */
162 public static final int EXISTS = 1<<23;
163
164 /** Flag is set for compiler-generated compound classes
165 * representing multiple variable bounds
166 */
167 public static final int COMPOUND = 1<<24;
168
169 /** Flag is set for class symbols if a class file was found for this class.
170 */
171 public static final int CLASS_SEEN = 1<<25;
172
173 /** Flag is set for class symbols if a source file was found for this
174 * class.
175 */
176 public static final int SOURCE_SEEN = 1<<26;
177
178 /* State flags (are reset during compilation).
179 */
180
181 /** Flag for class symbols is set and later re-set as a lock in
182 * Enter to detect cycles in the superclass/superinterface
183 * relations. Similarly for constructor call cycle detection in
184 * Attr.
185 */
186 public static final int LOCKED = 1<<27;
187
188 /** Flag for class symbols is set and later re-set to indicate that a class
189 * has been entered but has not yet been attributed.
190 */
191 public static final int UNATTRIBUTED = 1<<28;
192
193 /** Flag for synthesized default constructors of anonymous classes.
194 */
195 public static final int ANONCONSTR = 1<<29; //non-class members
196
197 /**
198 * Flag to indicate the superclasses of this ClassSymbol has been attributed.
199 */
200 public static final int SUPER_OWNER_ATTRIBUTED = 1<<29; //ClassSymbols
201
202 /** Flag for class symbols to indicate it has been checked and found
203 * acyclic.
204 */
205 public static final int ACYCLIC = 1<<30;
206
207 /** Flag that marks bridge methods.
208 */
209 public static final long BRIDGE = 1L<<31;
210
211 /** Flag that marks formal parameters.
212 */
213 public static final long PARAMETER = 1L<<33;
214
215 /** Flag that marks varargs methods.
216 */
217 public static final long VARARGS = 1L<<34;
218
219 /** Flag for annotation type symbols to indicate it has been
220 * checked and found acyclic.
221 */
222 public static final long ACYCLIC_ANN = 1L<<35;
223
224 /** Flag that marks a generated default constructor.
225 */
226 public static final long GENERATEDCONSTR = 1L<<36;
227
228 /** Flag that marks a hypothetical method that need not really be
229 * generated in the binary, but is present in the symbol table to
230 * simplify checking for erasure clashes - also used for 292 poly sig methods.
231 */
232 public static final long HYPOTHETICAL = 1L<<37;
233
234 /**
235 * Flag that marks an internal proprietary class.
236 */
237 public static final long PROPRIETARY = 1L<<38;
238
239 /**
240 * Flag that marks a multi-catch parameter.
241 */
242 public static final long UNION = 1L<<39;
243
244 /**
245 * Flags an erroneous TypeSymbol as viable for recovery.
246 * TypeSymbols only.
247 */
248 public static final long RECOVERABLE = 1L<<40;
249
250 /**
251 * Flag that marks an 'effectively final' local variable.
252 */
253 public static final long EFFECTIVELY_FINAL = 1L<<41;
254
255 /**
256 * Flag that marks non-override equivalent methods with the same signature,
257 * or a conflicting match binding (BindingSymbol).
258 */
259 public static final long CLASH = 1L<<42;
260
261 /**
262 * Flag that marks either a default method or an interface containing default methods.
263 */
264 public static final long DEFAULT = 1L<<43;
265
266 /**
267 * Flag that marks class as auxiliary, ie a non-public class following
268 * the public class in a source file, that could block implicit compilation.
269 */
270 public static final long AUXILIARY = 1L<<44;
271
272 /**
273 * Flag that marks that a symbol is not available in the current profile
274 */
275 public static final long NOT_IN_PROFILE = 1L<<45;
276
277 /**
278 * Flag that indicates that an override error has been detected by Check.
279 */
280 public static final long BAD_OVERRIDE = 1L<<45;
281
282 /**
283 * Flag that indicates a signature polymorphic method (292).
284 */
285 public static final long SIGNATURE_POLYMORPHIC = 1L<<46;
286
287 /**
288 * Flag that indicates that an inference variable is used in a 'throws' clause.
289 */
290 public static final long THROWS = 1L<<47;
291
292 /*
293 * Currently available: Bit 48.
294 */
295
296 /**
297 * Flag that marks a synthetic method body for a lambda expression
298 */
299 public static final long LAMBDA_METHOD = 1L<<49; //MethodSymbols only
300
301 /**
302 * Flag that marks a synthetic local capture field in a local/anon class
303 */
304 public static final long LOCAL_CAPTURE_FIELD = 1L<<49; //VarSymbols only
305
306 /**
307 * Flag to control recursion in TransTypes
308 */
309 public static final long TYPE_TRANSLATED = 1L<<50;
310
311 /**
312 * Flag to indicate class symbol is for module-info
313 */
314 public static final long MODULE = 1L<<51;
315
316 /**
317 * Flag to indicate the given ModuleSymbol is an automatic module.
318 */
319 public static final long AUTOMATIC_MODULE = 1L<<52; //ModuleSymbols only
320
321 /**
322 * Flag to indicate the given PackageSymbol contains any non-.java and non-.class resources.
323 */
324 public static final long HAS_RESOURCE = 1L<<52; //PackageSymbols only
325
326 /**
327 * Flag to indicate the given ParamSymbol has a user-friendly name filled.
328 */
329 public static final long NAME_FILLED = 1L<<52; //ParamSymbols only
330
331 /**
332 * Flag to indicate the given ModuleSymbol is a system module.
333 */
334 public static final long SYSTEM_MODULE = 1L<<53; //ModuleSymbols only
335
336 /**
337 * Flag to indicate the given ClassSymbol is a value based.
338 */
339 public static final long VALUE_BASED = 1L<<53; //ClassSymbols only
340
341 /**
342 * Flag to indicate the given ClassSymbol is a value based.
343 */
344 public static final long MIGRATED_VALUE_CLASS = 1L<<57; //ClassSymbols only
345
346 /**
347 * Flag to indicate the given symbol has a @Deprecated annotation.
348 */
349 public static final long DEPRECATED_ANNOTATION = 1L<<54;
350
351 /**
352 * Flag to indicate the given symbol has been deprecated and marked for removal.
353 */
354 public static final long DEPRECATED_REMOVAL = 1L<<55;
355
356 /**
357 * Flag to indicate the API element in question is for a preview API.
358 */
359 public static final long PREVIEW_API = 1L<<56; //any Symbol kind
360
361 /**
362 * Flag for synthesized default constructors of anonymous classes that have an enclosing expression.
363 */
364 public static final long ANONCONSTR_BASED = 1L<<57;
365
366 /**
367 * Flag that marks finalize block as body-only, should not be copied into catch clauses.
368 * Used to implement try-with-resources.
369 */
370 public static final long BODY_ONLY_FINALIZE = 1L<<17; //blocks only
371
372 /**
373 * Flag to indicate the API element in question is for a preview API.
374 */
375 public static final long PREVIEW_REFLECTIVE = 1L<<58; //any Symbol kind
376
377 /**
378 * Flag to indicate the given variable is a match binding variable.
379 */
380 public static final long MATCH_BINDING = 1L<<59;
381
382 /**
383 * A flag to indicate a match binding variable whose scope extends after the current statement.
384 */
385 public static final long MATCH_BINDING_TO_OUTER = 1L<<60;
386
387 /**
388 * Flag to indicate that a class is a record. The flag is also used to mark fields that are
389 * part of the state vector of a record and to mark the canonical constructor
390 */
391 public static final long RECORD = 1L<<61; // ClassSymbols, MethodSymbols and VarSymbols
392
393 /**
394 * Flag to mark a record constructor as a compact one
395 */
396 public static final long COMPACT_RECORD_CONSTRUCTOR = 1L<<51; // MethodSymbols only
397
398 /**
399 * Flag to mark a record field that was not initialized in the compact constructor
400 */
401 public static final long UNINITIALIZED_FIELD= 1L<<51; // VarSymbols only
402
403 /** Flag is set for compiler-generated record members, it could be applied to
404 * accessors and fields
405 */
406 public static final int GENERATED_MEMBER = 1<<24; // MethodSymbols and VarSymbols
407
408 /**
409 * Flag to indicate sealed class/interface declaration.
410 */
411 public static final long SEALED = 1L<<62; // ClassSymbols
412
413 /**
414 * Flag to indicate restricted method declaration.
415 */
416 public static final long RESTRICTED = 1L<<62; // MethodSymbols
417
418 /**
419 * Flag to indicate type annotations have been queued for field initializers.
420 */
421 public static final long FIELD_INIT_TYPE_ANNOTATIONS_QUEUED = 1L<<53; // VarSymbols
422
423 /**
424 * Flag to indicate that the class/interface was declared with the non-sealed modifier.
425 */
426 public static final long NON_SEALED = 1L<<63; // ClassSymbols
427
428 /**
429 * Flag to indicate that a class has at least one strict field
430 */
431 public static final long HAS_STRICT = 1L<<52; // ClassSymbols, temporary hack
432
433 /**
434 * Flag to indicate that a field is strict
435 */
436 public static final long STRICT = 1L<<53; // VarSymbols
437
438 /**
439 * Describe modifier flags as they might appear in source code, i.e.,
440 * separated by spaces and in the order suggested by JLS 8.1.1.
441 */
442 public static String toSource(long flags) {
443 return asModifierSet(flags).stream()
444 .map(Modifier::toString)
445 .collect(Collectors.joining(" "));
446 }
447
448 /** Modifier masks.
449 */
450 public static final int
451 AccessFlags = PUBLIC | PROTECTED | PRIVATE,
452 LocalClassFlags = FINAL | ABSTRACT | STRICTFP | ENUM | SYNTHETIC | IDENTITY_TYPE,
453 StaticLocalClassFlags = LocalClassFlags | STATIC | INTERFACE,
454 MemberClassFlags = LocalClassFlags | INTERFACE | AccessFlags,
455 MemberStaticClassFlags = MemberClassFlags | STATIC,
456 ClassFlags = LocalClassFlags | INTERFACE | PUBLIC | ANNOTATION,
457 InterfaceVarFlags = FINAL | STATIC | PUBLIC,
458 VarFlags = AccessFlags | FINAL | STATIC |
459 VOLATILE | TRANSIENT | ENUM,
460 ConstructorFlags = AccessFlags,
461 InterfaceMethodFlags = ABSTRACT | PUBLIC,
462 MethodFlags = AccessFlags | ABSTRACT | STATIC | NATIVE |
463 SYNCHRONIZED | FINAL | STRICTFP,
464 RecordMethodFlags = AccessFlags | ABSTRACT | STATIC |
465 SYNCHRONIZED | FINAL | STRICTFP;
466 public static final long
467 ExtendedStandardFlags = (long)StandardFlags | DEFAULT | SEALED | NON_SEALED | VALUE_CLASS,
468 ExtendedMemberClassFlags = (long)MemberClassFlags | SEALED | NON_SEALED | VALUE_CLASS,
469 ExtendedMemberStaticClassFlags = (long) MemberStaticClassFlags | SEALED | NON_SEALED | VALUE_CLASS,
470 ExtendedClassFlags = (long)ClassFlags | SEALED | NON_SEALED | VALUE_CLASS,
471 ExtendedLocalClassFlags = (long) LocalClassFlags | VALUE_CLASS,
472 ExtendedStaticLocalClassFlags = (long) StaticLocalClassFlags | VALUE_CLASS,
473 ValueFieldFlags = (long) VarFlags | STRICT | FINAL,
474 ModifierFlags = ((long)StandardFlags & ~INTERFACE) | DEFAULT | SEALED | NON_SEALED | VALUE_CLASS,
475 InterfaceMethodMask = ABSTRACT | PRIVATE | STATIC | PUBLIC | STRICTFP | DEFAULT,
476 AnnotationTypeElementMask = ABSTRACT | PUBLIC,
477 LocalVarFlags = FINAL | PARAMETER,
478 ReceiverParamFlags = PARAMETER;
479
480 public static Set<Modifier> asModifierSet(long flags) {
481 Set<Modifier> modifiers = modifierSets.get(flags);
482 if (modifiers == null) {
483 modifiers = java.util.EnumSet.noneOf(Modifier.class);
484 if (0 != (flags & PUBLIC)) modifiers.add(Modifier.PUBLIC);
485 if (0 != (flags & PROTECTED)) modifiers.add(Modifier.PROTECTED);
486 if (0 != (flags & PRIVATE)) modifiers.add(Modifier.PRIVATE);
487 if (0 != (flags & ABSTRACT)) modifiers.add(Modifier.ABSTRACT);
488 if (0 != (flags & STATIC)) modifiers.add(Modifier.STATIC);
489 if (0 != (flags & SEALED)) modifiers.add(Modifier.SEALED);
490 if (0 != (flags & NON_SEALED))
491 modifiers.add(Modifier.NON_SEALED);
492 if (0 != (flags & FINAL)) modifiers.add(Modifier.FINAL);
493 if (0 != (flags & TRANSIENT)) modifiers.add(Modifier.TRANSIENT);
494 if (0 != (flags & VOLATILE)) modifiers.add(Modifier.VOLATILE);
495 if (0 != (flags & SYNCHRONIZED))
496 modifiers.add(Modifier.SYNCHRONIZED);
497 if (0 != (flags & NATIVE)) modifiers.add(Modifier.NATIVE);
498 if (0 != (flags & STRICTFP)) modifiers.add(Modifier.STRICTFP);
499 if (0 != (flags & DEFAULT)) modifiers.add(Modifier.DEFAULT);
500 if (0 != (flags & VALUE_CLASS)) modifiers.add(Modifier.VALUE);
501 modifiers = Collections.unmodifiableSet(modifiers);
502 modifierSets.put(flags, modifiers);
503 }
504 return modifiers;
505 }
506
507 // Cache of modifier sets.
508 private static final Map<Long, Set<Modifier>> modifierSets = new ConcurrentHashMap<>(64);
509
510 public static boolean isStatic(Symbol symbol) {
511 return (symbol.flags() & STATIC) != 0;
512 }
513
514 public static boolean isEnum(Symbol symbol) {
515 return (symbol.flags() & ENUM) != 0;
516 }
517
518 public static boolean isConstant(Symbol.VarSymbol symbol) {
519 return symbol.getConstValue() != null;
520 }
521
522 public enum Flag {
523 PUBLIC(Flags.PUBLIC),
524 PRIVATE(Flags.PRIVATE),
525 PROTECTED(Flags.PROTECTED),
526 STATIC(Flags.STATIC),
527 FINAL(Flags.FINAL),
528 SYNCHRONIZED(Flags.SYNCHRONIZED),
529 VOLATILE(Flags.VOLATILE),
530 TRANSIENT(Flags.TRANSIENT),
531 NATIVE(Flags.NATIVE),
532 INTERFACE(Flags.INTERFACE),
533 ABSTRACT(Flags.ABSTRACT),
534 DEFAULT(Flags.DEFAULT),
535 STRICTFP(Flags.STRICTFP),
536 BRIDGE(Flags.BRIDGE),
537 SYNTHETIC(Flags.SYNTHETIC),
538 ANNOTATION(Flags.ANNOTATION),
539 DEPRECATED(Flags.DEPRECATED),
540 HASINIT(Flags.HASINIT),
541 IDENTITY_TYPE(Flags.IDENTITY_TYPE) {
542 @Override
543 public String toString() {
544 return "identity";
545 }
546 },
547 VALUE(Flags.VALUE_CLASS),
548 IMPLICIT_CLASS(Flags.IMPLICIT_CLASS),
549 BLOCK(Flags.BLOCK),
550 FROM_SOURCE(Flags.FROM_SOURCE),
551 ENUM(Flags.ENUM),
552 MANDATED(Flags.MANDATED),
553 NOOUTERTHIS(Flags.NOOUTERTHIS),
554 EXISTS(Flags.EXISTS),
555 COMPOUND(Flags.COMPOUND),
556 CLASS_SEEN(Flags.CLASS_SEEN),
557 SOURCE_SEEN(Flags.SOURCE_SEEN),
558 LOCKED(Flags.LOCKED),
559 UNATTRIBUTED(Flags.UNATTRIBUTED),
560 ANONCONSTR(Flags.ANONCONSTR),
561 ACYCLIC(Flags.ACYCLIC),
562 PARAMETER(Flags.PARAMETER),
563 VARARGS(Flags.VARARGS),
564 ACYCLIC_ANN(Flags.ACYCLIC_ANN),
565 GENERATEDCONSTR(Flags.GENERATEDCONSTR),
566 HYPOTHETICAL(Flags.HYPOTHETICAL),
567 PROPRIETARY(Flags.PROPRIETARY),
568 UNION(Flags.UNION),
569 EFFECTIVELY_FINAL(Flags.EFFECTIVELY_FINAL),
570 CLASH(Flags.CLASH),
571 AUXILIARY(Flags.AUXILIARY),
572 NOT_IN_PROFILE(Flags.NOT_IN_PROFILE),
573 BAD_OVERRIDE(Flags.BAD_OVERRIDE),
574 SIGNATURE_POLYMORPHIC(Flags.SIGNATURE_POLYMORPHIC),
575 THROWS(Flags.THROWS),
576 LAMBDA_METHOD(Flags.LAMBDA_METHOD),
577 TYPE_TRANSLATED(Flags.TYPE_TRANSLATED),
578 MODULE(Flags.MODULE),
579 AUTOMATIC_MODULE(Flags.AUTOMATIC_MODULE),
580 SYSTEM_MODULE(Flags.SYSTEM_MODULE),
581 DEPRECATED_ANNOTATION(Flags.DEPRECATED_ANNOTATION),
582 DEPRECATED_REMOVAL(Flags.DEPRECATED_REMOVAL),
583 HAS_RESOURCE(Flags.HAS_RESOURCE),
584 // Bit 48 is currently available
585 ANONCONSTR_BASED(Flags.ANONCONSTR_BASED),
586 NAME_FILLED(Flags.NAME_FILLED),
587 PREVIEW_API(Flags.PREVIEW_API),
588 PREVIEW_REFLECTIVE(Flags.PREVIEW_REFLECTIVE),
589 MATCH_BINDING(Flags.MATCH_BINDING),
590 MATCH_BINDING_TO_OUTER(Flags.MATCH_BINDING_TO_OUTER),
591 RECORD(Flags.RECORD),
592 RECOVERABLE(Flags.RECOVERABLE),
593 SEALED(Flags.SEALED),
594 NON_SEALED(Flags.NON_SEALED) {
595 @Override
596 public String toString() {
597 return "non-sealed";
598 }
599 },
600 STRICT(Flags.STRICT);
601
602 Flag(long flag) {
603 this.value = flag;
604 this.lowercaseName = StringUtils.toLowerCase(name());
605 }
606
607 @Override
608 public String toString() {
609 return lowercaseName;
610 }
611
612 final long value;
613 final String lowercaseName;
614 }
615
616 }