1 /*
2 * Copyright (c) 1999, 2023, 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;
300
301 /**
302 * Flag to control recursion in TransTypes
303 */
304 public static final long TYPE_TRANSLATED = 1L<<50;
305
306 /**
307 * Flag to indicate class symbol is for module-info
308 */
309 public static final long MODULE = 1L<<51;
310
311 /**
312 * Flag to indicate the given ModuleSymbol is an automatic module.
313 */
314 public static final long AUTOMATIC_MODULE = 1L<<52; //ModuleSymbols only
315
316 /**
317 * Flag to indicate the given PackageSymbol contains any non-.java and non-.class resources.
318 */
319 public static final long HAS_RESOURCE = 1L<<52; //PackageSymbols only
320
321 /**
322 * Flag to indicate the given ParamSymbol has a user-friendly name filled.
323 */
324 public static final long NAME_FILLED = 1L<<52; //ParamSymbols only
325
326 /**
327 * Flag to indicate the given ModuleSymbol is a system module.
328 */
329 public static final long SYSTEM_MODULE = 1L<<53; //ModuleSymbols only
330
331 /**
332 * Flag to indicate the given ClassSymbol is a value based.
333 */
334 public static final long VALUE_BASED = 1L<<53; //ClassSymbols only
335
336 /**
337 * Flag to indicate the given ClassSymbol is a value based.
338 */
339 public static final long MIGRATED_VALUE_CLASS = 1L<<57; //ClassSymbols only
340
341 /**
342 * Flag to indicate the given symbol has a @Deprecated annotation.
343 */
344 public static final long DEPRECATED_ANNOTATION = 1L<<54;
345
346 /**
347 * Flag to indicate the given symbol has been deprecated and marked for removal.
348 */
349 public static final long DEPRECATED_REMOVAL = 1L<<55;
350
351 /**
352 * Flag to indicate the API element in question is for a preview API.
353 */
354 public static final long PREVIEW_API = 1L<<56; //any Symbol kind
355
356 /**
357 * Flag for synthesized default constructors of anonymous classes that have an enclosing expression.
358 */
359 public static final long ANONCONSTR_BASED = 1L<<57;
360
361 /**
362 * Flag that marks finalize block as body-only, should not be copied into catch clauses.
363 * Used to implement try-with-resources.
364 */
365 public static final long BODY_ONLY_FINALIZE = 1L<<17; //blocks only
366
367 /**
368 * Flag to indicate the API element in question is for a preview API.
369 */
370 public static final long PREVIEW_REFLECTIVE = 1L<<58; //any Symbol kind
371
372 /**
373 * Flag to indicate the given variable is a match binding variable.
374 */
375 public static final long MATCH_BINDING = 1L<<59;
376
377 /**
378 * A flag to indicate a match binding variable whose scope extends after the current statement.
379 */
380 public static final long MATCH_BINDING_TO_OUTER = 1L<<60;
381
382 /**
383 * Flag to indicate that a class is a record. The flag is also used to mark fields that are
384 * part of the state vector of a record and to mark the canonical constructor
385 */
386 public static final long RECORD = 1L<<61; // ClassSymbols, MethodSymbols and VarSymbols
387
388 /**
389 * Flag to mark a record constructor as a compact one
390 */
391 public static final long COMPACT_RECORD_CONSTRUCTOR = 1L<<51; // MethodSymbols only
392
393 /**
394 * Flag to mark a record field that was not initialized in the compact constructor
395 */
396 public static final long UNINITIALIZED_FIELD= 1L<<51; // VarSymbols only
397
398 /** Flag is set for compiler-generated record members, it could be applied to
399 * accessors and fields
400 */
401 public static final int GENERATED_MEMBER = 1<<24; // MethodSymbols and VarSymbols
402
403 /**
404 * Flag to indicate sealed class/interface declaration.
405 */
406 public static final long SEALED = 1L<<62; // ClassSymbols
407
408 /**
409 * Flag to indicate restricted method declaration.
410 */
411 public static final long RESTRICTED = 1L<<62; // MethodSymbols
412
413 /**
414 * Flag to indicate that the class/interface was declared with the non-sealed modifier.
415 */
416 public static final long NON_SEALED = 1L<<63; // ClassSymbols
417
418 /**
419 * Flag to indicate that a field is strict
420 */
421 public static final long STRICT = 1L<<53; // VarSymbols
422
423 /**
424 * Describe modifier flags as they might appear in source code, i.e.,
425 * separated by spaces and in the order suggested by JLS 8.1.1.
426 */
427 public static String toSource(long flags) {
428 return asModifierSet(flags).stream()
429 .map(Modifier::toString)
430 .collect(Collectors.joining(" "));
431 }
432
433 /** Modifier masks.
434 */
435 public static final int
436 AccessFlags = PUBLIC | PROTECTED | PRIVATE,
437 LocalClassFlags = FINAL | ABSTRACT | STRICTFP | ENUM | SYNTHETIC | IDENTITY_TYPE,
438 StaticLocalClassFlags = LocalClassFlags | STATIC | INTERFACE,
439 MemberClassFlags = LocalClassFlags | INTERFACE | AccessFlags,
440 MemberStaticClassFlags = MemberClassFlags | STATIC,
441 ClassFlags = LocalClassFlags | INTERFACE | PUBLIC | ANNOTATION,
442 InterfaceVarFlags = FINAL | STATIC | PUBLIC,
443 VarFlags = AccessFlags | FINAL | STATIC |
444 VOLATILE | TRANSIENT | ENUM,
445 ConstructorFlags = AccessFlags,
446 InterfaceMethodFlags = ABSTRACT | PUBLIC,
447 MethodFlags = AccessFlags | ABSTRACT | STATIC | NATIVE |
448 SYNCHRONIZED | FINAL | STRICTFP,
449 RecordMethodFlags = AccessFlags | ABSTRACT | STATIC |
450 SYNCHRONIZED | FINAL | STRICTFP;
451 public static final long
452 ExtendedStandardFlags = (long)StandardFlags | DEFAULT | SEALED | NON_SEALED | VALUE_CLASS,
453 ExtendedMemberClassFlags = (long)MemberClassFlags | SEALED | NON_SEALED | VALUE_CLASS,
454 ExtendedMemberStaticClassFlags = (long) MemberStaticClassFlags | SEALED | NON_SEALED | VALUE_CLASS,
455 ExtendedClassFlags = (long)ClassFlags | SEALED | NON_SEALED | VALUE_CLASS,
456 ExtendedLocalClassFlags = (long) LocalClassFlags | VALUE_CLASS,
457 ExtendedStaticLocalClassFlags = (long) StaticLocalClassFlags | VALUE_CLASS,
458 ExtendedVarFlags = (long) VarFlags | STRICT,
459 ModifierFlags = ((long)StandardFlags & ~INTERFACE) | DEFAULT | SEALED | NON_SEALED | VALUE_CLASS,
460 InterfaceMethodMask = ABSTRACT | PRIVATE | STATIC | PUBLIC | STRICTFP | DEFAULT,
461 AnnotationTypeElementMask = ABSTRACT | PUBLIC,
462 LocalVarFlags = FINAL | PARAMETER,
463 ReceiverParamFlags = PARAMETER;
464
465 public static Set<Modifier> asModifierSet(long flags) {
466 Set<Modifier> modifiers = modifierSets.get(flags);
467 if (modifiers == null) {
468 modifiers = java.util.EnumSet.noneOf(Modifier.class);
469 if (0 != (flags & PUBLIC)) modifiers.add(Modifier.PUBLIC);
470 if (0 != (flags & PROTECTED)) modifiers.add(Modifier.PROTECTED);
471 if (0 != (flags & PRIVATE)) modifiers.add(Modifier.PRIVATE);
472 if (0 != (flags & ABSTRACT)) modifiers.add(Modifier.ABSTRACT);
473 if (0 != (flags & STATIC)) modifiers.add(Modifier.STATIC);
474 if (0 != (flags & SEALED)) modifiers.add(Modifier.SEALED);
475 if (0 != (flags & NON_SEALED))
476 modifiers.add(Modifier.NON_SEALED);
477 if (0 != (flags & FINAL)) modifiers.add(Modifier.FINAL);
478 if (0 != (flags & TRANSIENT)) modifiers.add(Modifier.TRANSIENT);
479 if (0 != (flags & VOLATILE)) modifiers.add(Modifier.VOLATILE);
480 if (0 != (flags & SYNCHRONIZED))
481 modifiers.add(Modifier.SYNCHRONIZED);
482 if (0 != (flags & NATIVE)) modifiers.add(Modifier.NATIVE);
483 if (0 != (flags & STRICTFP)) modifiers.add(Modifier.STRICTFP);
484 if (0 != (flags & DEFAULT)) modifiers.add(Modifier.DEFAULT);
485 if (0 != (flags & VALUE_CLASS)) modifiers.add(Modifier.VALUE);
486 modifiers = Collections.unmodifiableSet(modifiers);
487 modifierSets.put(flags, modifiers);
488 }
489 return modifiers;
490 }
491
492 // Cache of modifier sets.
493 private static final Map<Long, Set<Modifier>> modifierSets = new ConcurrentHashMap<>(64);
494
495 public static boolean isStatic(Symbol symbol) {
496 return (symbol.flags() & STATIC) != 0;
497 }
498
499 public static boolean isEnum(Symbol symbol) {
500 return (symbol.flags() & ENUM) != 0;
501 }
502
503 public static boolean isConstant(Symbol.VarSymbol symbol) {
504 return symbol.getConstValue() != null;
505 }
506
507 public enum Flag {
508 PUBLIC(Flags.PUBLIC),
509 PRIVATE(Flags.PRIVATE),
510 PROTECTED(Flags.PROTECTED),
511 STATIC(Flags.STATIC),
512 FINAL(Flags.FINAL),
513 SYNCHRONIZED(Flags.SYNCHRONIZED),
514 VOLATILE(Flags.VOLATILE),
515 TRANSIENT(Flags.TRANSIENT),
516 NATIVE(Flags.NATIVE),
517 INTERFACE(Flags.INTERFACE),
518 ABSTRACT(Flags.ABSTRACT),
519 DEFAULT(Flags.DEFAULT),
520 STRICTFP(Flags.STRICTFP),
521 BRIDGE(Flags.BRIDGE),
522 SYNTHETIC(Flags.SYNTHETIC),
523 ANNOTATION(Flags.ANNOTATION),
524 DEPRECATED(Flags.DEPRECATED),
525 HASINIT(Flags.HASINIT),
526 IDENTITY_TYPE(Flags.IDENTITY_TYPE) {
527 @Override
528 public String toString() {
529 return "identity";
530 }
531 },
532 VALUE(Flags.VALUE_CLASS),
533 IMPLICIT_CLASS(Flags.IMPLICIT_CLASS),
534 BLOCK(Flags.BLOCK),
535 FROM_SOURCE(Flags.FROM_SOURCE),
536 ENUM(Flags.ENUM),
537 MANDATED(Flags.MANDATED),
538 NOOUTERTHIS(Flags.NOOUTERTHIS),
539 EXISTS(Flags.EXISTS),
540 COMPOUND(Flags.COMPOUND),
541 CLASS_SEEN(Flags.CLASS_SEEN),
542 SOURCE_SEEN(Flags.SOURCE_SEEN),
543 LOCKED(Flags.LOCKED),
544 UNATTRIBUTED(Flags.UNATTRIBUTED),
545 ANONCONSTR(Flags.ANONCONSTR),
546 ACYCLIC(Flags.ACYCLIC),
547 PARAMETER(Flags.PARAMETER),
548 VARARGS(Flags.VARARGS),
549 ACYCLIC_ANN(Flags.ACYCLIC_ANN),
550 GENERATEDCONSTR(Flags.GENERATEDCONSTR),
551 HYPOTHETICAL(Flags.HYPOTHETICAL),
552 PROPRIETARY(Flags.PROPRIETARY),
553 UNION(Flags.UNION),
554 EFFECTIVELY_FINAL(Flags.EFFECTIVELY_FINAL),
555 CLASH(Flags.CLASH),
556 AUXILIARY(Flags.AUXILIARY),
557 NOT_IN_PROFILE(Flags.NOT_IN_PROFILE),
558 BAD_OVERRIDE(Flags.BAD_OVERRIDE),
559 SIGNATURE_POLYMORPHIC(Flags.SIGNATURE_POLYMORPHIC),
560 THROWS(Flags.THROWS),
561 LAMBDA_METHOD(Flags.LAMBDA_METHOD),
562 TYPE_TRANSLATED(Flags.TYPE_TRANSLATED),
563 MODULE(Flags.MODULE),
564 AUTOMATIC_MODULE(Flags.AUTOMATIC_MODULE),
565 SYSTEM_MODULE(Flags.SYSTEM_MODULE),
566 DEPRECATED_ANNOTATION(Flags.DEPRECATED_ANNOTATION),
567 DEPRECATED_REMOVAL(Flags.DEPRECATED_REMOVAL),
568 HAS_RESOURCE(Flags.HAS_RESOURCE),
569 // Bit 48 is currently available
570 ANONCONSTR_BASED(Flags.ANONCONSTR_BASED),
571 NAME_FILLED(Flags.NAME_FILLED),
572 PREVIEW_API(Flags.PREVIEW_API),
573 PREVIEW_REFLECTIVE(Flags.PREVIEW_REFLECTIVE),
574 MATCH_BINDING(Flags.MATCH_BINDING),
575 MATCH_BINDING_TO_OUTER(Flags.MATCH_BINDING_TO_OUTER),
576 RECORD(Flags.RECORD),
577 RECOVERABLE(Flags.RECOVERABLE),
578 SEALED(Flags.SEALED),
579 NON_SEALED(Flags.NON_SEALED) {
580 @Override
581 public String toString() {
582 return "non-sealed";
583 }
584 },
585 STRICT(Flags.STRICT);
586
587 Flag(long flag) {
588 this.value = flag;
589 this.lowercaseName = StringUtils.toLowerCase(name());
590 }
591
592 @Override
593 public String toString() {
594 return lowercaseName;
595 }
596
597 final long value;
598 final String lowercaseName;
599 }
600
601 }