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.comp;
27
28 import java.util.*;
29 import java.util.function.BiConsumer;
30 import java.util.function.BiPredicate;
31 import java.util.function.Function;
32 import java.util.function.Predicate;
33 import java.util.function.Supplier;
34 import java.util.function.ToIntBiFunction;
35 import java.util.stream.Collectors;
36 import java.util.stream.StreamSupport;
37
38 import javax.lang.model.element.ElementKind;
39 import javax.lang.model.element.NestingKind;
40 import javax.tools.JavaFileManager;
41
42 import com.sun.source.tree.CaseTree;
43 import com.sun.tools.javac.code.*;
44 import com.sun.tools.javac.code.Attribute.Compound;
45 import com.sun.tools.javac.code.Directive.ExportsDirective;
46 import com.sun.tools.javac.code.Directive.RequiresDirective;
47 import com.sun.tools.javac.code.Source.Feature;
48 import com.sun.tools.javac.comp.Annotate.AnnotationTypeMetadata;
49 import com.sun.tools.javac.jvm.*;
50 import com.sun.tools.javac.resources.CompilerProperties;
51 import com.sun.tools.javac.resources.CompilerProperties.Errors;
52 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
53 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
54 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings;
55 import com.sun.tools.javac.tree.*;
56 import com.sun.tools.javac.util.*;
57 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
58 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
59 import com.sun.tools.javac.util.JCDiagnostic.Error;
60 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
61 import com.sun.tools.javac.util.JCDiagnostic.LintWarning;
62 import com.sun.tools.javac.util.List;
63
64 import com.sun.tools.javac.code.Lint;
65 import com.sun.tools.javac.code.Lint.LintCategory;
66 import com.sun.tools.javac.code.Scope.WriteableScope;
67 import com.sun.tools.javac.code.Type.*;
68 import com.sun.tools.javac.code.Symbol.*;
69 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
70 import com.sun.tools.javac.tree.JCTree.*;
71
72 import static com.sun.tools.javac.code.Flags.*;
73 import static com.sun.tools.javac.code.Flags.ANNOTATION;
74 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED;
75 import static com.sun.tools.javac.code.Kinds.*;
76 import static com.sun.tools.javac.code.Kinds.Kind.*;
77 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
78 import static com.sun.tools.javac.code.Scope.LookupKind.RECURSIVE;
79 import static com.sun.tools.javac.code.TypeTag.*;
80 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
81
82 import static com.sun.tools.javac.tree.JCTree.Tag.*;
83 import javax.lang.model.element.Element;
84 import javax.lang.model.element.TypeElement;
85 import javax.lang.model.type.DeclaredType;
86 import javax.lang.model.util.ElementKindVisitor14;
87
88 /** Type checking helper class for the attribution phase.
89 *
90 * <p><b>This is NOT part of any supported API.
91 * If you write code that depends on this, you do so at your own risk.
92 * This code and its internal interfaces are subject to change or
93 * deletion without notice.</b>
94 */
95 public class Check {
96 protected static final Context.Key<Check> checkKey = new Context.Key<>();
97
98 // Flag bits indicating which item(s) chosen from a pair of items
99 private static final int FIRST = 0x01;
100 private static final int SECOND = 0x02;
101
102 private final Names names;
103 private final Log log;
104 private final Resolve rs;
105 private final Symtab syms;
106 private final Enter enter;
107 private final DeferredAttr deferredAttr;
108 private final Infer infer;
109 private final Types types;
110 private final TypeAnnotations typeAnnotations;
111 private final JCDiagnostic.Factory diags;
112 private final JavaFileManager fileManager;
113 private final Source source;
114 private final Target target;
115 private final Profile profile;
116 private final Preview preview;
117 private final boolean warnOnAnyAccessToMembers;
118
119 public boolean disablePreviewCheck;
120
121 // The set of lint options currently in effect. It is initialized
122 // from the context, and then is set/reset as needed by Attr as it
123 // visits all the various parts of the trees during attribution.
124 Lint lint;
125
126 // The method being analyzed in Attr - it is set/reset as needed by
127 // Attr as it visits new method declarations.
128 private MethodSymbol method;
129
130 public static Check instance(Context context) {
131 Check instance = context.get(checkKey);
132 if (instance == null)
133 instance = new Check(context);
134 return instance;
135 }
136
137 @SuppressWarnings("this-escape")
138 protected Check(Context context) {
139 context.put(checkKey, this);
140
141 names = Names.instance(context);
142 log = Log.instance(context);
143 rs = Resolve.instance(context);
144 syms = Symtab.instance(context);
145 enter = Enter.instance(context);
146 deferredAttr = DeferredAttr.instance(context);
147 infer = Infer.instance(context);
148 types = Types.instance(context);
149 typeAnnotations = TypeAnnotations.instance(context);
150 diags = JCDiagnostic.Factory.instance(context);
151 Options options = Options.instance(context);
152 lint = Lint.instance(context);
153 fileManager = context.get(JavaFileManager.class);
154
155 source = Source.instance(context);
156 target = Target.instance(context);
157 warnOnAnyAccessToMembers = options.isSet("warnOnAccessToMembers");
158
159 disablePreviewCheck = false;
160
161 Target target = Target.instance(context);
162 syntheticNameChar = target.syntheticNameChar();
163
164 profile = Profile.instance(context);
165 preview = Preview.instance(context);
166
167 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
168 boolean verboseRemoval = lint.isEnabled(LintCategory.REMOVAL);
169 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
170 boolean enforceMandatoryWarnings = true;
171
172 deprecationHandler = new MandatoryWarningHandler(log, null, verboseDeprecated,
173 enforceMandatoryWarnings, LintCategory.DEPRECATION, "deprecated");
174 removalHandler = new MandatoryWarningHandler(log, null, verboseRemoval,
175 enforceMandatoryWarnings, LintCategory.REMOVAL);
176 uncheckedHandler = new MandatoryWarningHandler(log, null, verboseUnchecked,
177 enforceMandatoryWarnings, LintCategory.UNCHECKED);
178
179 deferredLintHandler = DeferredLintHandler.instance(context);
180
181 allowModules = Feature.MODULES.allowedInSource(source);
182 allowRecords = Feature.RECORDS.allowedInSource(source);
183 allowSealed = Feature.SEALED_CLASSES.allowedInSource(source);
184 allowValueClasses = (!preview.isPreview(Feature.VALUE_CLASSES) || preview.isEnabled()) &&
185 Feature.VALUE_CLASSES.allowedInSource(source);
186 }
187
188 /** Character for synthetic names
189 */
190 char syntheticNameChar;
191
192 /** A table mapping flat names of all compiled classes for each module in this run
193 * to their symbols; maintained from outside.
194 */
195 private Map<Pair<ModuleSymbol, Name>,ClassSymbol> compiled = new HashMap<>();
196
197 /** A handler for messages about deprecated usage.
198 */
199 private MandatoryWarningHandler deprecationHandler;
200
201 /** A handler for messages about deprecated-for-removal usage.
202 */
203 private MandatoryWarningHandler removalHandler;
204
205 /** A handler for messages about unchecked or unsafe usage.
206 */
207 private MandatoryWarningHandler uncheckedHandler;
208
209 /** A handler for deferred lint warnings.
210 */
211 private DeferredLintHandler deferredLintHandler;
212
213 /** Are modules allowed
214 */
215 private final boolean allowModules;
216
217 /** Are records allowed
218 */
219 private final boolean allowRecords;
220
221 /** Are sealed classes allowed
222 */
223 private final boolean allowSealed;
224
225 /** Are value classes allowed
226 */
227 private final boolean allowValueClasses;
228
229 /** Whether to force suppression of deprecation and preview warnings.
230 * This happens when attributing import statements for JDK 9+.
231 * @see Feature#DEPRECATION_ON_IMPORT
232 */
233 private boolean importSuppression;
234
235 /* *************************************************************************
236 * Errors and Warnings
237 **************************************************************************/
238
239 Lint setLint(Lint newLint) {
240 Lint prev = lint;
241 lint = newLint;
242 return prev;
243 }
244
245 boolean setImportSuppression(boolean newImportSuppression) {
246 boolean prev = importSuppression;
247 importSuppression = newImportSuppression;
248 return prev;
249 }
250
251 MethodSymbol setMethod(MethodSymbol newMethod) {
252 MethodSymbol prev = method;
253 method = newMethod;
254 return prev;
255 }
256
257 /** Warn about deprecated symbol.
258 * @param pos Position to be used for error reporting.
259 * @param sym The deprecated symbol.
260 */
261 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
262 if (sym.isDeprecatedForRemoval()) {
263 if (!lint.isSuppressed(LintCategory.REMOVAL)) {
264 if (sym.kind == MDL) {
265 removalHandler.report(pos, LintWarnings.HasBeenDeprecatedForRemovalModule(sym));
266 } else {
267 removalHandler.report(pos, LintWarnings.HasBeenDeprecatedForRemoval(sym, sym.location()));
268 }
269 }
270 } else if (!lint.isSuppressed(LintCategory.DEPRECATION)) {
271 if (sym.kind == MDL) {
272 deprecationHandler.report(pos, LintWarnings.HasBeenDeprecatedModule(sym));
273 } else {
274 deprecationHandler.report(pos, LintWarnings.HasBeenDeprecated(sym, sym.location()));
275 }
276 }
277 }
278
279 /** Log a preview warning.
280 * @param pos Position to be used for error reporting.
281 * @param msg A Warning describing the problem.
282 */
283 public void warnPreviewAPI(DiagnosticPosition pos, LintWarning warnKey) {
284 if (!importSuppression && !lint.isSuppressed(LintCategory.PREVIEW))
285 preview.reportPreviewWarning(pos, warnKey);
286 }
287
288 /** Log a preview warning.
289 * @param pos Position to be used for error reporting.
290 * @param msg A Warning describing the problem.
291 */
292 public void warnRestrictedAPI(DiagnosticPosition pos, Symbol sym) {
293 lint.logIfEnabled(pos, LintWarnings.RestrictedMethod(sym.enclClass(), sym));
294 }
295
296 /** Warn about unchecked operation.
297 * @param pos Position to be used for error reporting.
298 * @param msg A string describing the problem.
299 */
300 public void warnUnchecked(DiagnosticPosition pos, LintWarning warnKey) {
301 if (!lint.isSuppressed(LintCategory.UNCHECKED))
302 uncheckedHandler.report(pos, warnKey);
303 }
304
305 /**
306 * Report any deferred diagnostics.
307 */
308 public void reportDeferredDiagnostics() {
309 deprecationHandler.reportDeferredDiagnostic();
310 removalHandler.reportDeferredDiagnostic();
311 uncheckedHandler.reportDeferredDiagnostic();
312 }
313
314
315 /** Report a failure to complete a class.
316 * @param pos Position to be used for error reporting.
317 * @param ex The failure to report.
318 */
319 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
320 log.error(JCDiagnostic.DiagnosticFlag.NON_DEFERRABLE, pos, Errors.CantAccess(ex.sym, ex.getDetailValue()));
321 return syms.errType;
322 }
323
324 /** Report an error that wrong type tag was found.
325 * @param pos Position to be used for error reporting.
326 * @param required An internationalized string describing the type tag
327 * required.
328 * @param found The type that was found.
329 */
330 Type typeTagError(DiagnosticPosition pos, JCDiagnostic required, Object found) {
331 // this error used to be raised by the parser,
332 // but has been delayed to this point:
333 if (found instanceof Type type && type.hasTag(VOID)) {
334 log.error(pos, Errors.IllegalStartOfType);
335 return syms.errType;
336 }
337 log.error(pos, Errors.TypeFoundReq(found, required));
338 return types.createErrorType(found instanceof Type type ? type : syms.errType);
339 }
340
341 /** Report duplicate declaration error.
342 */
343 void duplicateError(DiagnosticPosition pos, Symbol sym) {
344 if (!sym.type.isErroneous()) {
345 Symbol location = sym.location();
346 if (location.kind == MTH &&
347 ((MethodSymbol)location).isStaticOrInstanceInit()) {
348 log.error(pos,
349 Errors.AlreadyDefinedInClinit(kindName(sym),
350 sym,
351 kindName(sym.location()),
352 kindName(sym.location().enclClass()),
353 sym.location().enclClass()));
354 } else {
355 /* dont error if this is a duplicated parameter of a generated canonical constructor
356 * as we should have issued an error for the duplicated fields
357 */
358 if (location.kind != MTH ||
359 ((sym.owner.flags_field & GENERATEDCONSTR) == 0) ||
360 ((sym.owner.flags_field & RECORD) == 0)) {
361 log.error(pos,
362 Errors.AlreadyDefined(kindName(sym),
363 sym,
364 kindName(sym.location()),
365 sym.location()));
366 }
367 }
368 }
369 }
370
371 /** Report array/varargs duplicate declaration
372 */
373 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
374 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
375 log.error(pos, Errors.ArrayAndVarargs(sym1, sym2, sym2.location()));
376 }
377 }
378
379 /* ************************************************************************
380 * duplicate declaration checking
381 *************************************************************************/
382
383 /** Check that variable does not hide variable with same name in
384 * immediately enclosing local scope.
385 * @param pos Position for error reporting.
386 * @param v The symbol.
387 * @param s The scope.
388 */
389 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
390 for (Symbol sym : s.getSymbolsByName(v.name)) {
391 if (sym.owner != v.owner) break;
392 if (sym.kind == VAR &&
393 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
394 v.name != names.error) {
395 duplicateError(pos, sym);
396 return;
397 }
398 }
399 }
400
401 /** Check that a class or interface does not hide a class or
402 * interface with same name in immediately enclosing local scope.
403 * @param pos Position for error reporting.
404 * @param c The symbol.
405 * @param s The scope.
406 */
407 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
408 for (Symbol sym : s.getSymbolsByName(c.name)) {
409 if (sym.owner != c.owner) break;
410 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR) &&
411 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
412 c.name != names.error) {
413 duplicateError(pos, sym);
414 return;
415 }
416 }
417 }
418
419 /** Check that class does not have the same name as one of
420 * its enclosing classes, or as a class defined in its enclosing scope.
421 * return true if class is unique in its enclosing scope.
422 * @param pos Position for error reporting.
423 * @param name The class name.
424 * @param s The enclosing scope.
425 */
426 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
427 for (Symbol sym : s.getSymbolsByName(name, NON_RECURSIVE)) {
428 if (sym.kind == TYP && sym.name != names.error) {
429 duplicateError(pos, sym);
430 return false;
431 }
432 }
433 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
434 if (sym.kind == TYP && sym.name == name && sym.name != names.error &&
435 !sym.isImplicit()) {
436 duplicateError(pos, sym);
437 return true;
438 }
439 }
440 return true;
441 }
442
443 /* *************************************************************************
444 * Class name generation
445 **************************************************************************/
446
447
448 private Map<Pair<Name, Name>, Integer> localClassNameIndexes = new HashMap<>();
449
450 /** Return name of local class.
451 * This is of the form {@code <enclClass> $ n <classname> }
452 * where
453 * enclClass is the flat name of the enclosing class,
454 * classname is the simple name of the local class
455 */
456 public Name localClassName(ClassSymbol c) {
457 Name enclFlatname = c.owner.enclClass().flatname;
458 String enclFlatnameStr = enclFlatname.toString();
459 Pair<Name, Name> key = new Pair<>(enclFlatname, c.name);
460 Integer index = localClassNameIndexes.get(key);
461 for (int i = (index == null) ? 1 : index; ; i++) {
462 Name flatname = names.fromString(enclFlatnameStr
463 + syntheticNameChar + i + c.name);
464 if (getCompiled(c.packge().modle, flatname) == null) {
465 localClassNameIndexes.put(key, i + 1);
466 return flatname;
467 }
468 }
469 }
470
471 public void clearLocalClassNameIndexes(ClassSymbol c) {
472 if (c.owner != null && c.owner.kind != NIL) {
473 localClassNameIndexes.remove(new Pair<>(
474 c.owner.enclClass().flatname, c.name));
475 }
476 }
477
478 public void newRound() {
479 compiled.clear();
480 localClassNameIndexes.clear();
481 }
482
483 public void clear() {
484 deprecationHandler.clear();
485 removalHandler.clear();
486 uncheckedHandler.clear();
487 }
488
489 public void putCompiled(ClassSymbol csym) {
490 compiled.put(Pair.of(csym.packge().modle, csym.flatname), csym);
491 }
492
493 public ClassSymbol getCompiled(ClassSymbol csym) {
494 return compiled.get(Pair.of(csym.packge().modle, csym.flatname));
495 }
496
497 public ClassSymbol getCompiled(ModuleSymbol msym, Name flatname) {
498 return compiled.get(Pair.of(msym, flatname));
499 }
500
501 public void removeCompiled(ClassSymbol csym) {
502 compiled.remove(Pair.of(csym.packge().modle, csym.flatname));
503 }
504
505 /* *************************************************************************
506 * Type Checking
507 **************************************************************************/
508
509 /**
510 * A check context is an object that can be used to perform compatibility
511 * checks - depending on the check context, meaning of 'compatibility' might
512 * vary significantly.
513 */
514 public interface CheckContext {
515 /**
516 * Is type 'found' compatible with type 'req' in given context
517 */
518 boolean compatible(Type found, Type req, Warner warn);
519 /**
520 * Report a check error
521 */
522 void report(DiagnosticPosition pos, JCDiagnostic details);
523 /**
524 * Obtain a warner for this check context
525 */
526 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req);
527
528 public InferenceContext inferenceContext();
529
530 public DeferredAttr.DeferredAttrContext deferredAttrContext();
531 }
532
533 /**
534 * This class represent a check context that is nested within another check
535 * context - useful to check sub-expressions. The default behavior simply
536 * redirects all method calls to the enclosing check context leveraging
537 * the forwarding pattern.
538 */
539 static class NestedCheckContext implements CheckContext {
540 CheckContext enclosingContext;
541
542 NestedCheckContext(CheckContext enclosingContext) {
543 this.enclosingContext = enclosingContext;
544 }
545
546 public boolean compatible(Type found, Type req, Warner warn) {
547 return enclosingContext.compatible(found, req, warn);
548 }
549
550 public void report(DiagnosticPosition pos, JCDiagnostic details) {
551 enclosingContext.report(pos, details);
552 }
553
554 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
555 return enclosingContext.checkWarner(pos, found, req);
556 }
557
558 public InferenceContext inferenceContext() {
559 return enclosingContext.inferenceContext();
560 }
561
562 public DeferredAttrContext deferredAttrContext() {
563 return enclosingContext.deferredAttrContext();
564 }
565 }
566
567 /**
568 * Check context to be used when evaluating assignment/return statements
569 */
570 CheckContext basicHandler = new CheckContext() {
571 public void report(DiagnosticPosition pos, JCDiagnostic details) {
572 log.error(pos, Errors.ProbFoundReq(details));
573 }
574 public boolean compatible(Type found, Type req, Warner warn) {
575 return types.isAssignable(found, req, warn);
576 }
577
578 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
579 return convertWarner(pos, found, req);
580 }
581
582 public InferenceContext inferenceContext() {
583 return infer.emptyContext;
584 }
585
586 public DeferredAttrContext deferredAttrContext() {
587 return deferredAttr.emptyDeferredAttrContext;
588 }
589
590 @Override
591 public String toString() {
592 return "CheckContext: basicHandler";
593 }
594 };
595
596 /** Check that a given type is assignable to a given proto-type.
597 * If it is, return the type, otherwise return errType.
598 * @param pos Position to be used for error reporting.
599 * @param found The type that was found.
600 * @param req The type that was required.
601 */
602 public Type checkType(DiagnosticPosition pos, Type found, Type req) {
603 return checkType(pos, found, req, basicHandler);
604 }
605
606 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) {
607 final InferenceContext inferenceContext = checkContext.inferenceContext();
608 if (inferenceContext.free(req) || inferenceContext.free(found)) {
609 inferenceContext.addFreeTypeListener(List.of(req, found),
610 solvedContext -> checkType(pos, solvedContext.asInstType(found), solvedContext.asInstType(req), checkContext));
611 }
612 if (req.hasTag(ERROR))
613 return req;
614 if (req.hasTag(NONE))
615 return found;
616 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) {
617 return found;
618 } else {
619 if (found.isNumeric() && req.isNumeric()) {
620 checkContext.report(pos, diags.fragment(Fragments.PossibleLossOfPrecision(found, req)));
621 return types.createErrorType(found);
622 }
623 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
624 return types.createErrorType(found);
625 }
626 }
627
628 /** Check that a given type can be cast to a given target type.
629 * Return the result of the cast.
630 * @param pos Position to be used for error reporting.
631 * @param found The type that is being cast.
632 * @param req The target type of the cast.
633 */
634 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
635 return checkCastable(pos, found, req, basicHandler);
636 }
637 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) {
638 if (types.isCastable(found, req, castWarner(pos, found, req))) {
639 return req;
640 } else {
641 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
642 return types.createErrorType(found);
643 }
644 }
645
646 /** Check for redundant casts (i.e. where source type is a subtype of target type)
647 * The problem should only be reported for non-292 cast
648 */
649 public void checkRedundantCast(Env<AttrContext> env, final JCTypeCast tree) {
650 if (!tree.type.isErroneous()
651 && types.isSameType(tree.expr.type, tree.clazz.type)
652 && !(ignoreAnnotatedCasts && TreeInfo.containsTypeAnnotation(tree.clazz))
653 && !is292targetTypeCast(tree)) {
654 deferredLintHandler.report(_l -> {
655 lint.logIfEnabled(tree.pos(), LintWarnings.RedundantCast(tree.clazz.type));
656 });
657 }
658 }
659 //where
660 private boolean is292targetTypeCast(JCTypeCast tree) {
661 boolean is292targetTypeCast = false;
662 JCExpression expr = TreeInfo.skipParens(tree.expr);
663 if (expr.hasTag(APPLY)) {
664 JCMethodInvocation apply = (JCMethodInvocation)expr;
665 Symbol sym = TreeInfo.symbol(apply.meth);
666 is292targetTypeCast = sym != null &&
667 sym.kind == MTH &&
668 (sym.flags() & HYPOTHETICAL) != 0;
669 }
670 return is292targetTypeCast;
671 }
672
673 private static final boolean ignoreAnnotatedCasts = true;
674
675 /** Check that a type is within some bounds.
676 *
677 * Used in TypeApply to verify that, e.g., X in {@code V<X>} is a valid
678 * type argument.
679 * @param a The type that should be bounded by bs.
680 * @param bound The bound.
681 */
682 private boolean checkExtends(Type a, Type bound) {
683 if (a.isUnbound()) {
684 return true;
685 } else if (!a.hasTag(WILDCARD)) {
686 a = types.cvarUpperBound(a);
687 return types.isSubtype(a, bound);
688 } else if (a.isExtendsBound()) {
689 return types.isCastable(bound, types.wildUpperBound(a), types.noWarnings);
690 } else if (a.isSuperBound()) {
691 return !types.notSoftSubtype(types.wildLowerBound(a), bound);
692 }
693 return true;
694 }
695
696 /** Check that type is different from 'void'.
697 * @param pos Position to be used for error reporting.
698 * @param t The type to be checked.
699 */
700 Type checkNonVoid(DiagnosticPosition pos, Type t) {
701 if (t.hasTag(VOID)) {
702 log.error(pos, Errors.VoidNotAllowedHere);
703 return types.createErrorType(t);
704 } else {
705 return t;
706 }
707 }
708
709 Type checkClassOrArrayType(DiagnosticPosition pos, Type t) {
710 if (!t.hasTag(CLASS) && !t.hasTag(ARRAY) && !t.hasTag(ERROR)) {
711 return typeTagError(pos,
712 diags.fragment(Fragments.TypeReqClassArray),
713 asTypeParam(t));
714 } else {
715 return t;
716 }
717 }
718
719 /** Check that type is a class or interface type.
720 * @param pos Position to be used for error reporting.
721 * @param t The type to be checked.
722 */
723 Type checkClassType(DiagnosticPosition pos, Type t) {
724 if (!t.hasTag(CLASS) && !t.hasTag(ERROR)) {
725 return typeTagError(pos,
726 diags.fragment(Fragments.TypeReqClass),
727 asTypeParam(t));
728 } else {
729 return t;
730 }
731 }
732 //where
733 private Object asTypeParam(Type t) {
734 return (t.hasTag(TYPEVAR))
735 ? diags.fragment(Fragments.TypeParameter(t))
736 : t;
737 }
738
739 void checkConstraintsOfValueClass(JCClassDecl tree, ClassSymbol c) {
740 DiagnosticPosition pos = tree.pos();
741 for (Type st : types.closure(c.type)) {
742 if (st == null || st.tsym == null || st.tsym.kind == ERR)
743 continue;
744 if (st.tsym == syms.objectType.tsym || st.tsym == syms.recordType.tsym || st.isInterface())
745 continue;
746 if (!st.tsym.isAbstract()) {
747 if (c != st.tsym) {
748 log.error(pos, Errors.ConcreteSupertypeForValueClass(c, st));
749 }
750 continue;
751 }
752 // dealing with an abstract value or value super class below.
753 for (Symbol s : st.tsym.members().getSymbols(NON_RECURSIVE)) {
754 if (s.kind == MTH) {
755 if ((s.flags() & (SYNCHRONIZED | STATIC)) == SYNCHRONIZED) {
756 log.error(pos, Errors.SuperClassMethodCannotBeSynchronized(s, c, st));
757 }
758 break;
759 }
760 }
761 }
762 }
763
764 /** Check that type is a valid qualifier for a constructor reference expression
765 */
766 Type checkConstructorRefType(DiagnosticPosition pos, Type t) {
767 t = checkClassOrArrayType(pos, t);
768 if (t.hasTag(CLASS)) {
769 if ((t.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
770 log.error(pos, Errors.AbstractCantBeInstantiated(t.tsym));
771 t = types.createErrorType(t);
772 } else if ((t.tsym.flags() & ENUM) != 0) {
773 log.error(pos, Errors.EnumCantBeInstantiated);
774 t = types.createErrorType(t);
775 } else {
776 t = checkClassType(pos, t, true);
777 }
778 } else if (t.hasTag(ARRAY)) {
779 if (!types.isReifiable(((ArrayType)t).elemtype)) {
780 log.error(pos, Errors.GenericArrayCreation);
781 t = types.createErrorType(t);
782 }
783 }
784 return t;
785 }
786
787 /** Check that type is a class or interface type.
788 * @param pos Position to be used for error reporting.
789 * @param t The type to be checked.
790 * @param noBounds True if type bounds are illegal here.
791 */
792 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
793 t = checkClassType(pos, t);
794 if (noBounds && t.isParameterized()) {
795 List<Type> args = t.getTypeArguments();
796 while (args.nonEmpty()) {
797 if (args.head.hasTag(WILDCARD))
798 return typeTagError(pos,
799 diags.fragment(Fragments.TypeReqExact),
800 args.head);
801 args = args.tail;
802 }
803 }
804 return t;
805 }
806
807 /** Check that type is a reference type, i.e. a class, interface or array type
808 * or a type variable.
809 * @param pos Position to be used for error reporting.
810 * @param t The type to be checked.
811 */
812 Type checkRefType(DiagnosticPosition pos, Type t) {
813 if (t.isReference())
814 return t;
815 else
816 return typeTagError(pos,
817 diags.fragment(Fragments.TypeReqRef),
818 t);
819 }
820
821 /** Check that type is an identity type, i.e. not a value type.
822 * When not discernible statically, give it the benefit of doubt
823 * and defer to runtime.
824 *
825 * @param pos Position to be used for error reporting.
826 * @param t The type to be checked.
827 */
828 boolean checkIdentityType(DiagnosticPosition pos, Type t) {
829 if (t.hasTag(TYPEVAR)) {
830 t = types.skipTypeVars(t, false);
831 }
832 if (t.isIntersection()) {
833 IntersectionClassType ict = (IntersectionClassType)t;
834 boolean result = true;
835 for (Type component : ict.getExplicitComponents()) {
836 result &= checkIdentityType(pos, component);
837 }
838 return result;
839 }
840 if (t.isPrimitive() || (t.isValueClass() && !t.tsym.isAbstract())) {
841 typeTagError(pos, diags.fragment(Fragments.TypeReqIdentity), t);
842 return false;
843 }
844 return true;
845 }
846
847 /** Check that each type is a reference type, i.e. a class, interface or array type
848 * or a type variable.
849 * @param trees Original trees, used for error reporting.
850 * @param types The types to be checked.
851 */
852 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
853 List<JCExpression> tl = trees;
854 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
855 l.head = checkRefType(tl.head.pos(), l.head);
856 tl = tl.tail;
857 }
858 return types;
859 }
860
861 /** Check that type is a null or reference type.
862 * @param pos Position to be used for error reporting.
863 * @param t The type to be checked.
864 */
865 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
866 if (t.isReference() || t.hasTag(BOT))
867 return t;
868 else
869 return typeTagError(pos,
870 diags.fragment(Fragments.TypeReqRef),
871 t);
872 }
873
874 /** Check that flag set does not contain elements of two conflicting sets. s
875 * Return true if it doesn't.
876 * @param pos Position to be used for error reporting.
877 * @param flags The set of flags to be checked.
878 * @param set1 Conflicting flags set #1.
879 * @param set2 Conflicting flags set #2.
880 */
881 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
882 if ((flags & set1) != 0 && (flags & set2) != 0) {
883 log.error(pos,
884 Errors.IllegalCombinationOfModifiers(asFlagSet(TreeInfo.firstFlag(flags & set1)),
885 asFlagSet(TreeInfo.firstFlag(flags & set2))));
886 return false;
887 } else
888 return true;
889 }
890
891 /** Check that usage of diamond operator is correct (i.e. diamond should not
892 * be used with non-generic classes or in anonymous class creation expressions)
893 */
894 Type checkDiamond(JCNewClass tree, Type t) {
895 if (!TreeInfo.isDiamond(tree) ||
896 t.isErroneous()) {
897 return checkClassType(tree.clazz.pos(), t, true);
898 } else {
899 if (tree.def != null && !Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.allowedInSource(source)) {
900 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.clazz.pos(),
901 Errors.CantApplyDiamond1(t, Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.fragment(source.name)));
902 }
903 if (t.tsym.type.getTypeArguments().isEmpty()) {
904 log.error(tree.clazz.pos(),
905 Errors.CantApplyDiamond1(t,
906 Fragments.DiamondNonGeneric(t)));
907 return types.createErrorType(t);
908 } else if (tree.typeargs != null &&
909 tree.typeargs.nonEmpty()) {
910 log.error(tree.clazz.pos(),
911 Errors.CantApplyDiamond1(t,
912 Fragments.DiamondAndExplicitParams(t)));
913 return types.createErrorType(t);
914 } else {
915 return t;
916 }
917 }
918 }
919
920 /** Check that the type inferred using the diamond operator does not contain
921 * non-denotable types such as captured types or intersection types.
922 * @param t the type inferred using the diamond operator
923 * @return the (possibly empty) list of non-denotable types.
924 */
925 List<Type> checkDiamondDenotable(ClassType t) {
926 ListBuffer<Type> buf = new ListBuffer<>();
927 for (Type arg : t.allparams()) {
928 if (!checkDenotable(arg)) {
929 buf.append(arg);
930 }
931 }
932 return buf.toList();
933 }
934
935 public boolean checkDenotable(Type t) {
936 return denotableChecker.visit(t, null);
937 }
938 // where
939
940 /** diamondTypeChecker: A type visitor that descends down the given type looking for non-denotable
941 * types. The visit methods return false as soon as a non-denotable type is encountered and true
942 * otherwise.
943 */
944 private static final Types.SimpleVisitor<Boolean, Void> denotableChecker = new Types.SimpleVisitor<Boolean, Void>() {
945 @Override
946 public Boolean visitType(Type t, Void s) {
947 return true;
948 }
949 @Override
950 public Boolean visitClassType(ClassType t, Void s) {
951 if (t.isUnion() || t.isIntersection()) {
952 return false;
953 }
954 for (Type targ : t.allparams()) {
955 if (!visit(targ, s)) {
956 return false;
957 }
958 }
959 return true;
960 }
961
962 @Override
963 public Boolean visitTypeVar(TypeVar t, Void s) {
964 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
965 (i.e cannot have been produced by inference (18.4))
966 */
967 return (t.tsym.flags() & SYNTHETIC) == 0;
968 }
969
970 @Override
971 public Boolean visitCapturedType(CapturedType t, Void s) {
972 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
973 (i.e cannot have been produced by capture conversion (5.1.10))
974 */
975 return false;
976 }
977
978 @Override
979 public Boolean visitArrayType(ArrayType t, Void s) {
980 return visit(t.elemtype, s);
981 }
982
983 @Override
984 public Boolean visitWildcardType(WildcardType t, Void s) {
985 return visit(t.type, s);
986 }
987 };
988
989 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
990 MethodSymbol m = tree.sym;
991 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
992 Type varargElemType = null;
993 if (m.isVarArgs()) {
994 varargElemType = types.elemtype(tree.params.last().type);
995 }
996 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
997 if (varargElemType != null) {
998 JCDiagnostic msg = Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ?
999 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargs(m)) :
1000 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargsFinalOnly(m));
1001 log.error(tree,
1002 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
1003 msg));
1004 } else {
1005 log.error(tree,
1006 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
1007 Fragments.VarargsTrustmeOnNonVarargsMeth(m)));
1008 }
1009 } else if (hasTrustMeAnno && varargElemType != null &&
1010 types.isReifiable(varargElemType)) {
1011 lint.logIfEnabled(tree, LintWarnings.VarargsRedundantTrustmeAnno(
1012 syms.trustMeType.tsym,
1013 diags.fragment(Fragments.VarargsTrustmeOnReifiableVarargs(varargElemType))));
1014 }
1015 else if (!hasTrustMeAnno && varargElemType != null &&
1016 !types.isReifiable(varargElemType)) {
1017 warnUnchecked(tree.params.head.pos(), LintWarnings.UncheckedVarargsNonReifiableType(varargElemType));
1018 }
1019 }
1020 //where
1021 private boolean isTrustMeAllowedOnMethod(Symbol s) {
1022 return (s.flags() & VARARGS) != 0 &&
1023 (s.isConstructor() ||
1024 (s.flags() & (STATIC | FINAL |
1025 (Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ? PRIVATE : 0) )) != 0);
1026 }
1027
1028 Type checkLocalVarType(DiagnosticPosition pos, Type t, Name name) {
1029 //check that resulting type is not the null type
1030 if (t.hasTag(BOT)) {
1031 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferNull));
1032 return types.createErrorType(t);
1033 } else if (t.hasTag(VOID)) {
1034 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferVoid));
1035 return types.createErrorType(t);
1036 }
1037
1038 //upward project the initializer type
1039 return types.upward(t, types.captures(t)).baseType();
1040 }
1041
1042 Type checkMethod(final Type mtype,
1043 final Symbol sym,
1044 final Env<AttrContext> env,
1045 final List<JCExpression> argtrees,
1046 final List<Type> argtypes,
1047 final boolean useVarargs,
1048 InferenceContext inferenceContext) {
1049 // System.out.println("call : " + env.tree);
1050 // System.out.println("method : " + owntype);
1051 // System.out.println("actuals: " + argtypes);
1052 if (inferenceContext.free(mtype)) {
1053 inferenceContext.addFreeTypeListener(List.of(mtype),
1054 solvedContext -> checkMethod(solvedContext.asInstType(mtype), sym, env, argtrees, argtypes, useVarargs, solvedContext));
1055 return mtype;
1056 }
1057 Type owntype = mtype;
1058 List<Type> formals = owntype.getParameterTypes();
1059 List<Type> nonInferred = sym.type.getParameterTypes();
1060 if (nonInferred.length() != formals.length()) nonInferred = formals;
1061 Type last = useVarargs ? formals.last() : null;
1062 if (sym.name == names.init && sym.owner == syms.enumSym) {
1063 formals = formals.tail.tail;
1064 nonInferred = nonInferred.tail.tail;
1065 }
1066 if ((sym.flags() & ANONCONSTR_BASED) != 0) {
1067 formals = formals.tail;
1068 nonInferred = nonInferred.tail;
1069 }
1070 List<JCExpression> args = argtrees;
1071 if (args != null) {
1072 //this is null when type-checking a method reference
1073 while (formals.head != last) {
1074 JCTree arg = args.head;
1075 Warner warn = convertWarner(arg.pos(), arg.type, nonInferred.head);
1076 assertConvertible(arg, arg.type, formals.head, warn);
1077 args = args.tail;
1078 formals = formals.tail;
1079 nonInferred = nonInferred.tail;
1080 }
1081 if (useVarargs) {
1082 Type varArg = types.elemtype(last);
1083 while (args.tail != null) {
1084 JCTree arg = args.head;
1085 Warner warn = convertWarner(arg.pos(), arg.type, varArg);
1086 assertConvertible(arg, arg.type, varArg, warn);
1087 args = args.tail;
1088 }
1089 } else if ((sym.flags() & (VARARGS | SIGNATURE_POLYMORPHIC)) == VARARGS) {
1090 // non-varargs call to varargs method
1091 Type varParam = owntype.getParameterTypes().last();
1092 Type lastArg = argtypes.last();
1093 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
1094 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
1095 log.warning(argtrees.last().pos(),
1096 Warnings.InexactNonVarargsCall(types.elemtype(varParam),varParam));
1097 }
1098 }
1099 if (useVarargs) {
1100 Type argtype = owntype.getParameterTypes().last();
1101 if (!types.isReifiable(argtype) &&
1102 (sym.baseSymbol().attribute(syms.trustMeType.tsym) == null ||
1103 !isTrustMeAllowedOnMethod(sym))) {
1104 warnUnchecked(env.tree.pos(), LintWarnings.UncheckedGenericArrayCreation(argtype));
1105 }
1106 TreeInfo.setVarargsElement(env.tree, types.elemtype(argtype));
1107 }
1108 return owntype;
1109 }
1110 //where
1111 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
1112 if (types.isConvertible(actual, formal, warn))
1113 return;
1114
1115 if (formal.isCompound()
1116 && types.isSubtype(actual, types.supertype(formal))
1117 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
1118 return;
1119 }
1120
1121 /**
1122 * Check that type 't' is a valid instantiation of a generic class
1123 * (see JLS 4.5)
1124 *
1125 * @param t class type to be checked
1126 * @return true if 't' is well-formed
1127 */
1128 public boolean checkValidGenericType(Type t) {
1129 return firstIncompatibleTypeArg(t) == null;
1130 }
1131 //WHERE
1132 private Type firstIncompatibleTypeArg(Type type) {
1133 List<Type> formals = type.tsym.type.allparams();
1134 List<Type> actuals = type.allparams();
1135 List<Type> args = type.getTypeArguments();
1136 List<Type> forms = type.tsym.type.getTypeArguments();
1137 ListBuffer<Type> bounds_buf = new ListBuffer<>();
1138
1139 // For matching pairs of actual argument types `a' and
1140 // formal type parameters with declared bound `b' ...
1141 while (args.nonEmpty() && forms.nonEmpty()) {
1142 // exact type arguments needs to know their
1143 // bounds (for upper and lower bound
1144 // calculations). So we create new bounds where
1145 // type-parameters are replaced with actuals argument types.
1146 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals));
1147 args = args.tail;
1148 forms = forms.tail;
1149 }
1150
1151 args = type.getTypeArguments();
1152 List<Type> tvars_cap = types.substBounds(formals,
1153 formals,
1154 types.capture(type).allparams());
1155 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
1156 // Let the actual arguments know their bound
1157 args.head.withTypeVar((TypeVar)tvars_cap.head);
1158 args = args.tail;
1159 tvars_cap = tvars_cap.tail;
1160 }
1161
1162 args = type.getTypeArguments();
1163 List<Type> bounds = bounds_buf.toList();
1164
1165 while (args.nonEmpty() && bounds.nonEmpty()) {
1166 Type actual = args.head;
1167 if (!isTypeArgErroneous(actual) &&
1168 !bounds.head.isErroneous() &&
1169 !checkExtends(actual, bounds.head)) {
1170 return args.head;
1171 }
1172 args = args.tail;
1173 bounds = bounds.tail;
1174 }
1175
1176 args = type.getTypeArguments();
1177 bounds = bounds_buf.toList();
1178
1179 for (Type arg : types.capture(type).getTypeArguments()) {
1180 if (arg.hasTag(TYPEVAR) &&
1181 arg.getUpperBound().isErroneous() &&
1182 !bounds.head.isErroneous() &&
1183 !isTypeArgErroneous(args.head)) {
1184 return args.head;
1185 }
1186 bounds = bounds.tail;
1187 args = args.tail;
1188 }
1189
1190 return null;
1191 }
1192 //where
1193 boolean isTypeArgErroneous(Type t) {
1194 return isTypeArgErroneous.visit(t);
1195 }
1196
1197 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
1198 public Boolean visitType(Type t, Void s) {
1199 return t.isErroneous();
1200 }
1201 @Override
1202 public Boolean visitTypeVar(TypeVar t, Void s) {
1203 return visit(t.getUpperBound());
1204 }
1205 @Override
1206 public Boolean visitCapturedType(CapturedType t, Void s) {
1207 return visit(t.getUpperBound()) ||
1208 visit(t.getLowerBound());
1209 }
1210 @Override
1211 public Boolean visitWildcardType(WildcardType t, Void s) {
1212 return visit(t.type);
1213 }
1214 };
1215
1216 /** Check that given modifiers are legal for given symbol and
1217 * return modifiers together with any implicit modifiers for that symbol.
1218 * Warning: we can't use flags() here since this method
1219 * is called during class enter, when flags() would cause a premature
1220 * completion.
1221 * @param flags The set of modifiers given in a definition.
1222 * @param sym The defined symbol.
1223 * @param tree The declaration
1224 */
1225 long checkFlags(long flags, Symbol sym, JCTree tree) {
1226 final DiagnosticPosition pos = tree.pos();
1227 long mask;
1228 long implicit = 0;
1229
1230 switch (sym.kind) {
1231 case VAR:
1232 if (TreeInfo.isReceiverParam(tree))
1233 mask = ReceiverParamFlags;
1234 else if (sym.owner.kind != TYP)
1235 mask = LocalVarFlags;
1236 else if ((sym.owner.flags_field & INTERFACE) != 0)
1237 mask = implicit = InterfaceVarFlags;
1238 else {
1239 boolean isInstanceField = (flags & STATIC) == 0;
1240 boolean isInstanceFieldOfValueClass = isInstanceField && sym.owner.type.isValueClass();
1241 boolean isRecordField = isInstanceField && (sym.owner.flags_field & RECORD) != 0;
1242 if (allowValueClasses && (isInstanceFieldOfValueClass || isRecordField)) {
1243 implicit |= FINAL | STRICT;
1244 mask = ValueFieldFlags;
1245 } else {
1246 mask = VarFlags;
1247 }
1248 }
1249 break;
1250 case MTH:
1251 if (sym.name == names.init) {
1252 if ((sym.owner.flags_field & ENUM) != 0) {
1253 // enum constructors cannot be declared public or
1254 // protected and must be implicitly or explicitly
1255 // private
1256 implicit = PRIVATE;
1257 mask = PRIVATE;
1258 } else
1259 mask = ConstructorFlags;
1260 } else if ((sym.owner.flags_field & INTERFACE) != 0) {
1261 if ((sym.owner.flags_field & ANNOTATION) != 0) {
1262 mask = AnnotationTypeElementMask;
1263 implicit = PUBLIC | ABSTRACT;
1264 } else if ((flags & (DEFAULT | STATIC | PRIVATE)) != 0) {
1265 mask = InterfaceMethodMask;
1266 implicit = (flags & PRIVATE) != 0 ? 0 : PUBLIC;
1267 if ((flags & DEFAULT) != 0) {
1268 implicit |= ABSTRACT;
1269 }
1270 } else {
1271 mask = implicit = InterfaceMethodFlags;
1272 }
1273 } else if ((sym.owner.flags_field & RECORD) != 0) {
1274 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ?
1275 RecordMethodFlags & ~SYNCHRONIZED : RecordMethodFlags;
1276 } else {
1277 // value objects do not have an associated monitor/lock
1278 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ?
1279 MethodFlags & ~SYNCHRONIZED : MethodFlags;
1280 }
1281 if ((flags & STRICTFP) != 0) {
1282 warnOnExplicitStrictfp(tree);
1283 }
1284 // Imply STRICTFP if owner has STRICTFP set.
1285 if (((flags|implicit) & Flags.ABSTRACT) == 0 ||
1286 ((flags) & Flags.DEFAULT) != 0)
1287 implicit |= sym.owner.flags_field & STRICTFP;
1288 break;
1289 case TYP:
1290 if (sym.owner.kind.matches(KindSelector.VAL_MTH) ||
1291 (sym.isDirectlyOrIndirectlyLocal() && (flags & ANNOTATION) != 0)) {
1292 boolean implicitlyStatic = !sym.isAnonymous() &&
1293 ((flags & RECORD) != 0 || (flags & ENUM) != 0 || (flags & INTERFACE) != 0);
1294 boolean staticOrImplicitlyStatic = (flags & STATIC) != 0 || implicitlyStatic;
1295 // local statics are allowed only if records are allowed too
1296 mask = staticOrImplicitlyStatic && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedStaticLocalClassFlags : ExtendedLocalClassFlags;
1297 implicit = implicitlyStatic ? STATIC : implicit;
1298 } else if (sym.owner.kind == TYP) {
1299 // statics in inner classes are allowed only if records are allowed too
1300 mask = ((flags & STATIC) != 0) && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedMemberStaticClassFlags : ExtendedMemberClassFlags;
1301 if (sym.owner.owner.kind == PCK ||
1302 (sym.owner.flags_field & STATIC) != 0) {
1303 mask |= STATIC;
1304 } else if (!allowRecords && ((flags & ENUM) != 0 || (flags & RECORD) != 0)) {
1305 log.error(pos, Errors.StaticDeclarationNotAllowedInInnerClasses);
1306 }
1307 // Nested interfaces and enums are always STATIC (Spec ???)
1308 if ((flags & (INTERFACE | ENUM | RECORD)) != 0 ) implicit = STATIC;
1309 } else {
1310 mask = ExtendedClassFlags;
1311 }
1312 if ((flags & (VALUE_CLASS | SEALED | ABSTRACT)) == (VALUE_CLASS | SEALED) ||
1313 (flags & (VALUE_CLASS | NON_SEALED | ABSTRACT)) == (VALUE_CLASS | NON_SEALED)) {
1314 log.error(pos, Errors.NonAbstractValueClassCantBeSealedOrNonSealed);
1315 }
1316 // Interfaces are always ABSTRACT
1317 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
1318
1319 if ((flags & (INTERFACE | VALUE_CLASS)) == 0) {
1320 implicit |= IDENTITY_TYPE;
1321 }
1322
1323 if ((flags & ENUM) != 0) {
1324 // enums can't be declared abstract, final, sealed or non-sealed or value
1325 mask &= ~(ABSTRACT | FINAL | SEALED | NON_SEALED | VALUE_CLASS);
1326 implicit |= implicitEnumFinalFlag(tree);
1327 }
1328 if ((flags & RECORD) != 0) {
1329 // records can't be declared abstract
1330 mask &= ~ABSTRACT;
1331 implicit |= FINAL;
1332 }
1333 if ((flags & STRICTFP) != 0) {
1334 warnOnExplicitStrictfp(tree);
1335 }
1336 // Imply STRICTFP if owner has STRICTFP set.
1337 implicit |= sym.owner.flags_field & STRICTFP;
1338
1339 // concrete value classes are implicitly final
1340 if ((flags & (ABSTRACT | INTERFACE | VALUE_CLASS)) == VALUE_CLASS) {
1341 implicit |= FINAL;
1342 }
1343 break;
1344 default:
1345 throw new AssertionError();
1346 }
1347 long illegal = flags & ExtendedStandardFlags & ~mask;
1348 if (illegal != 0) {
1349 if ((illegal & INTERFACE) != 0) {
1350 log.error(pos, ((flags & ANNOTATION) != 0) ? Errors.AnnotationDeclNotAllowedHere : Errors.IntfNotAllowedHere);
1351 mask |= INTERFACE;
1352 }
1353 else {
1354 log.error(pos,
1355 Errors.ModNotAllowedHere(asFlagSet(illegal)));
1356 }
1357 } else if ((sym.kind == TYP ||
1358 // ISSUE: Disallowing abstract&private is no longer appropriate
1359 // in the presence of inner classes. Should it be deleted here?
1360 checkDisjoint(pos, flags,
1361 ABSTRACT,
1362 PRIVATE | STATIC | DEFAULT))
1363 &&
1364 checkDisjoint(pos, flags,
1365 STATIC | PRIVATE,
1366 DEFAULT)
1367 &&
1368 checkDisjoint(pos, flags,
1369 ABSTRACT | INTERFACE,
1370 FINAL | NATIVE | SYNCHRONIZED)
1371 &&
1372 checkDisjoint(pos, flags,
1373 PUBLIC,
1374 PRIVATE | PROTECTED)
1375 &&
1376 checkDisjoint(pos, flags,
1377 PRIVATE,
1378 PUBLIC | PROTECTED)
1379 &&
1380 // we are using `implicit` here as instance fields of value classes are implicitly final
1381 checkDisjoint(pos, flags | implicit,
1382 FINAL,
1383 VOLATILE)
1384 &&
1385 (sym.kind == TYP ||
1386 checkDisjoint(pos, flags,
1387 ABSTRACT | NATIVE,
1388 STRICTFP))
1389 && checkDisjoint(pos, flags,
1390 FINAL,
1391 SEALED | NON_SEALED)
1392 && checkDisjoint(pos, flags,
1393 SEALED,
1394 FINAL | NON_SEALED)
1395 && checkDisjoint(pos, flags,
1396 SEALED,
1397 ANNOTATION)
1398 && checkDisjoint(pos, flags,
1399 VALUE_CLASS,
1400 ANNOTATION)
1401 && checkDisjoint(pos, flags,
1402 VALUE_CLASS,
1403 INTERFACE) ) {
1404 // skip
1405 }
1406 return flags & (mask | ~ExtendedStandardFlags) | implicit;
1407 }
1408
1409 private void warnOnExplicitStrictfp(JCTree tree) {
1410 deferredLintHandler.push(tree);
1411 try {
1412 deferredLintHandler.report(_ -> lint.logIfEnabled(tree.pos(), LintWarnings.Strictfp));
1413 } finally {
1414 deferredLintHandler.pop();
1415 }
1416 }
1417
1418
1419 /** Determine if this enum should be implicitly final.
1420 *
1421 * If the enum has no specialized enum constants, it is final.
1422 *
1423 * If the enum does have specialized enum constants, it is
1424 * <i>not</i> final.
1425 */
1426 private long implicitEnumFinalFlag(JCTree tree) {
1427 if (!tree.hasTag(CLASSDEF)) return 0;
1428 class SpecialTreeVisitor extends JCTree.Visitor {
1429 boolean specialized;
1430 SpecialTreeVisitor() {
1431 this.specialized = false;
1432 }
1433
1434 @Override
1435 public void visitTree(JCTree tree) { /* no-op */ }
1436
1437 @Override
1438 public void visitVarDef(JCVariableDecl tree) {
1439 if ((tree.mods.flags & ENUM) != 0) {
1440 if (tree.init instanceof JCNewClass newClass && newClass.def != null) {
1441 specialized = true;
1442 }
1443 }
1444 }
1445 }
1446
1447 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1448 JCClassDecl cdef = (JCClassDecl) tree;
1449 for (JCTree defs: cdef.defs) {
1450 defs.accept(sts);
1451 if (sts.specialized) return allowSealed ? SEALED : 0;
1452 }
1453 return FINAL;
1454 }
1455
1456 /* *************************************************************************
1457 * Type Validation
1458 **************************************************************************/
1459
1460 /** Validate a type expression. That is,
1461 * check that all type arguments of a parametric type are within
1462 * their bounds. This must be done in a second phase after type attribution
1463 * since a class might have a subclass as type parameter bound. E.g:
1464 *
1465 * <pre>{@code
1466 * class B<A extends C> { ... }
1467 * class C extends B<C> { ... }
1468 * }</pre>
1469 *
1470 * and we can't make sure that the bound is already attributed because
1471 * of possible cycles.
1472 *
1473 * Visitor method: Validate a type expression, if it is not null, catching
1474 * and reporting any completion failures.
1475 */
1476 void validate(JCTree tree, Env<AttrContext> env) {
1477 validate(tree, env, true);
1478 }
1479 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1480 new Validator(env).validateTree(tree, checkRaw, true);
1481 }
1482
1483 /** Visitor method: Validate a list of type expressions.
1484 */
1485 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1486 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1487 validate(l.head, env);
1488 }
1489
1490 /** A visitor class for type validation.
1491 */
1492 class Validator extends JCTree.Visitor {
1493
1494 boolean checkRaw;
1495 boolean isOuter;
1496 Env<AttrContext> env;
1497
1498 Validator(Env<AttrContext> env) {
1499 this.env = env;
1500 }
1501
1502 @Override
1503 public void visitTypeArray(JCArrayTypeTree tree) {
1504 validateTree(tree.elemtype, checkRaw, isOuter);
1505 }
1506
1507 @Override
1508 public void visitTypeApply(JCTypeApply tree) {
1509 if (tree.type.hasTag(CLASS)) {
1510 List<JCExpression> args = tree.arguments;
1511 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1512
1513 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1514 if (incompatibleArg != null) {
1515 for (JCTree arg : tree.arguments) {
1516 if (arg.type == incompatibleArg) {
1517 log.error(arg, Errors.NotWithinBounds(incompatibleArg, forms.head));
1518 }
1519 forms = forms.tail;
1520 }
1521 }
1522
1523 forms = tree.type.tsym.type.getTypeArguments();
1524
1525 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1526
1527 // For matching pairs of actual argument types `a' and
1528 // formal type parameters with declared bound `b' ...
1529 while (args.nonEmpty() && forms.nonEmpty()) {
1530 validateTree(args.head,
1531 !(isOuter && is_java_lang_Class),
1532 false);
1533 args = args.tail;
1534 forms = forms.tail;
1535 }
1536
1537 // Check that this type is either fully parameterized, or
1538 // not parameterized at all.
1539 if (tree.type.getEnclosingType().isRaw())
1540 log.error(tree.pos(), Errors.ImproperlyFormedTypeInnerRawParam);
1541 if (tree.clazz.hasTag(SELECT))
1542 visitSelectInternal((JCFieldAccess)tree.clazz);
1543 }
1544 }
1545
1546 @Override
1547 public void visitTypeParameter(JCTypeParameter tree) {
1548 validateTrees(tree.bounds, true, isOuter);
1549 checkClassBounds(tree.pos(), tree.type);
1550 }
1551
1552 @Override
1553 public void visitWildcard(JCWildcard tree) {
1554 if (tree.inner != null)
1555 validateTree(tree.inner, true, isOuter);
1556 }
1557
1558 @Override
1559 public void visitSelect(JCFieldAccess tree) {
1560 if (tree.type.hasTag(CLASS)) {
1561 visitSelectInternal(tree);
1562
1563 // Check that this type is either fully parameterized, or
1564 // not parameterized at all.
1565 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1566 log.error(tree.pos(), Errors.ImproperlyFormedTypeParamMissing);
1567 }
1568 }
1569
1570 public void visitSelectInternal(JCFieldAccess tree) {
1571 if (tree.type.tsym.isStatic() &&
1572 tree.selected.type.isParameterized()) {
1573 // The enclosing type is not a class, so we are
1574 // looking at a static member type. However, the
1575 // qualifying expression is parameterized.
1576 log.error(tree.pos(), Errors.CantSelectStaticClassFromParamType);
1577 } else {
1578 // otherwise validate the rest of the expression
1579 tree.selected.accept(this);
1580 }
1581 }
1582
1583 @Override
1584 public void visitAnnotatedType(JCAnnotatedType tree) {
1585 tree.underlyingType.accept(this);
1586 }
1587
1588 @Override
1589 public void visitTypeIdent(JCPrimitiveTypeTree that) {
1590 if (that.type.hasTag(TypeTag.VOID)) {
1591 log.error(that.pos(), Errors.VoidNotAllowedHere);
1592 }
1593 super.visitTypeIdent(that);
1594 }
1595
1596 /** Default visitor method: do nothing.
1597 */
1598 @Override
1599 public void visitTree(JCTree tree) {
1600 }
1601
1602 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1603 if (tree != null) {
1604 boolean prevCheckRaw = this.checkRaw;
1605 this.checkRaw = checkRaw;
1606 this.isOuter = isOuter;
1607
1608 try {
1609 tree.accept(this);
1610 if (checkRaw)
1611 checkRaw(tree, env);
1612 } catch (CompletionFailure ex) {
1613 completionError(tree.pos(), ex);
1614 } finally {
1615 this.checkRaw = prevCheckRaw;
1616 }
1617 }
1618 }
1619
1620 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1621 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1622 validateTree(l.head, checkRaw, isOuter);
1623 }
1624 }
1625
1626 void checkRaw(JCTree tree, Env<AttrContext> env) {
1627 if (tree.type.hasTag(CLASS) &&
1628 !TreeInfo.isDiamond(tree) &&
1629 !withinAnonConstr(env) &&
1630 tree.type.isRaw()) {
1631 lint.logIfEnabled(tree.pos(), LintWarnings.RawClassUse(tree.type, tree.type.tsym.type));
1632 }
1633 }
1634 //where
1635 private boolean withinAnonConstr(Env<AttrContext> env) {
1636 return env.enclClass.name.isEmpty() &&
1637 env.enclMethod != null && env.enclMethod.name == names.init;
1638 }
1639
1640 /* *************************************************************************
1641 * Exception checking
1642 **************************************************************************/
1643
1644 /* The following methods treat classes as sets that contain
1645 * the class itself and all their subclasses
1646 */
1647
1648 /** Is given type a subtype of some of the types in given list?
1649 */
1650 boolean subset(Type t, List<Type> ts) {
1651 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1652 if (types.isSubtype(t, l.head)) return true;
1653 return false;
1654 }
1655
1656 /** Is given type a subtype or supertype of
1657 * some of the types in given list?
1658 */
1659 boolean intersects(Type t, List<Type> ts) {
1660 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1661 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1662 return false;
1663 }
1664
1665 /** Add type set to given type list, unless it is a subclass of some class
1666 * in the list.
1667 */
1668 List<Type> incl(Type t, List<Type> ts) {
1669 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1670 }
1671
1672 /** Remove type set from type set list.
1673 */
1674 List<Type> excl(Type t, List<Type> ts) {
1675 if (ts.isEmpty()) {
1676 return ts;
1677 } else {
1678 List<Type> ts1 = excl(t, ts.tail);
1679 if (types.isSubtype(ts.head, t)) return ts1;
1680 else if (ts1 == ts.tail) return ts;
1681 else return ts1.prepend(ts.head);
1682 }
1683 }
1684
1685 /** Form the union of two type set lists.
1686 */
1687 List<Type> union(List<Type> ts1, List<Type> ts2) {
1688 List<Type> ts = ts1;
1689 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1690 ts = incl(l.head, ts);
1691 return ts;
1692 }
1693
1694 /** Form the difference of two type lists.
1695 */
1696 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1697 List<Type> ts = ts1;
1698 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1699 ts = excl(l.head, ts);
1700 return ts;
1701 }
1702
1703 /** Form the intersection of two type lists.
1704 */
1705 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1706 List<Type> ts = List.nil();
1707 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1708 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1709 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1710 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1711 return ts;
1712 }
1713
1714 /** Is exc an exception symbol that need not be declared?
1715 */
1716 boolean isUnchecked(ClassSymbol exc) {
1717 return
1718 exc.kind == ERR ||
1719 exc.isSubClass(syms.errorType.tsym, types) ||
1720 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1721 }
1722
1723 /** Is exc an exception type that need not be declared?
1724 */
1725 boolean isUnchecked(Type exc) {
1726 return
1727 (exc.hasTag(TYPEVAR)) ? isUnchecked(types.supertype(exc)) :
1728 (exc.hasTag(CLASS)) ? isUnchecked((ClassSymbol)exc.tsym) :
1729 exc.hasTag(BOT);
1730 }
1731
1732 boolean isChecked(Type exc) {
1733 return !isUnchecked(exc);
1734 }
1735
1736 /** Same, but handling completion failures.
1737 */
1738 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1739 try {
1740 return isUnchecked(exc);
1741 } catch (CompletionFailure ex) {
1742 completionError(pos, ex);
1743 return true;
1744 }
1745 }
1746
1747 /** Is exc handled by given exception list?
1748 */
1749 boolean isHandled(Type exc, List<Type> handled) {
1750 return isUnchecked(exc) || subset(exc, handled);
1751 }
1752
1753 /** Return all exceptions in thrown list that are not in handled list.
1754 * @param thrown The list of thrown exceptions.
1755 * @param handled The list of handled exceptions.
1756 */
1757 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1758 List<Type> unhandled = List.nil();
1759 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1760 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1761 return unhandled;
1762 }
1763
1764 /* *************************************************************************
1765 * Overriding/Implementation checking
1766 **************************************************************************/
1767
1768 /** The level of access protection given by a flag set,
1769 * where PRIVATE is highest and PUBLIC is lowest.
1770 */
1771 static int protection(long flags) {
1772 switch ((short)(flags & AccessFlags)) {
1773 case PRIVATE: return 3;
1774 case PROTECTED: return 1;
1775 default:
1776 case PUBLIC: return 0;
1777 case 0: return 2;
1778 }
1779 }
1780
1781 /** A customized "cannot override" error message.
1782 * @param m The overriding method.
1783 * @param other The overridden method.
1784 * @return An internationalized string.
1785 */
1786 Fragment cannotOverride(MethodSymbol m, MethodSymbol other) {
1787 Symbol mloc = m.location();
1788 Symbol oloc = other.location();
1789
1790 if ((other.owner.flags() & INTERFACE) == 0)
1791 return Fragments.CantOverride(m, mloc, other, oloc);
1792 else if ((m.owner.flags() & INTERFACE) == 0)
1793 return Fragments.CantImplement(m, mloc, other, oloc);
1794 else
1795 return Fragments.ClashesWith(m, mloc, other, oloc);
1796 }
1797
1798 /** A customized "override" warning message.
1799 * @param m The overriding method.
1800 * @param other The overridden method.
1801 * @return An internationalized string.
1802 */
1803 Fragment uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1804 Symbol mloc = m.location();
1805 Symbol oloc = other.location();
1806
1807 if ((other.owner.flags() & INTERFACE) == 0)
1808 return Fragments.UncheckedOverride(m, mloc, other, oloc);
1809 else if ((m.owner.flags() & INTERFACE) == 0)
1810 return Fragments.UncheckedImplement(m, mloc, other, oloc);
1811 else
1812 return Fragments.UncheckedClashWith(m, mloc, other, oloc);
1813 }
1814
1815 /** A customized "override" warning message.
1816 * @param m The overriding method.
1817 * @param other The overridden method.
1818 * @return An internationalized string.
1819 */
1820 Fragment varargsOverrides(MethodSymbol m, MethodSymbol other) {
1821 Symbol mloc = m.location();
1822 Symbol oloc = other.location();
1823
1824 if ((other.owner.flags() & INTERFACE) == 0)
1825 return Fragments.VarargsOverride(m, mloc, other, oloc);
1826 else if ((m.owner.flags() & INTERFACE) == 0)
1827 return Fragments.VarargsImplement(m, mloc, other, oloc);
1828 else
1829 return Fragments.VarargsClashWith(m, mloc, other, oloc);
1830 }
1831
1832 /** Check that this method conforms with overridden method 'other'.
1833 * where `origin' is the class where checking started.
1834 * Complications:
1835 * (1) Do not check overriding of synthetic methods
1836 * (reason: they might be final).
1837 * todo: check whether this is still necessary.
1838 * (2) Admit the case where an interface proxy throws fewer exceptions
1839 * than the method it implements. Augment the proxy methods with the
1840 * undeclared exceptions in this case.
1841 * (3) When generics are enabled, admit the case where an interface proxy
1842 * has a result type
1843 * extended by the result type of the method it implements.
1844 * Change the proxies result type to the smaller type in this case.
1845 *
1846 * @param tree The tree from which positions
1847 * are extracted for errors.
1848 * @param m The overriding method.
1849 * @param other The overridden method.
1850 * @param origin The class of which the overriding method
1851 * is a member.
1852 */
1853 void checkOverride(JCTree tree,
1854 MethodSymbol m,
1855 MethodSymbol other,
1856 ClassSymbol origin) {
1857 // Don't check overriding of synthetic methods or by bridge methods.
1858 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1859 return;
1860 }
1861
1862 // Error if static method overrides instance method (JLS 8.4.8.2).
1863 if ((m.flags() & STATIC) != 0 &&
1864 (other.flags() & STATIC) == 0) {
1865 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1866 Errors.OverrideStatic(cannotOverride(m, other)));
1867 m.flags_field |= BAD_OVERRIDE;
1868 return;
1869 }
1870
1871 // Error if instance method overrides static or final
1872 // method (JLS 8.4.8.1).
1873 if ((other.flags() & FINAL) != 0 ||
1874 (m.flags() & STATIC) == 0 &&
1875 (other.flags() & STATIC) != 0) {
1876 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1877 Errors.OverrideMeth(cannotOverride(m, other),
1878 asFlagSet(other.flags() & (FINAL | STATIC))));
1879 m.flags_field |= BAD_OVERRIDE;
1880 return;
1881 }
1882
1883 if ((m.owner.flags() & ANNOTATION) != 0) {
1884 // handled in validateAnnotationMethod
1885 return;
1886 }
1887
1888 // Error if overriding method has weaker access (JLS 8.4.8.3).
1889 if (protection(m.flags()) > protection(other.flags())) {
1890 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1891 (other.flags() & AccessFlags) == 0 ?
1892 Errors.OverrideWeakerAccess(cannotOverride(m, other),
1893 "package") :
1894 Errors.OverrideWeakerAccess(cannotOverride(m, other),
1895 asFlagSet(other.flags() & AccessFlags)));
1896 m.flags_field |= BAD_OVERRIDE;
1897 return;
1898 }
1899
1900 if (shouldCheckPreview(m, other, origin)) {
1901 checkPreview(TreeInfo.diagnosticPositionFor(m, tree),
1902 m, origin.type, other);
1903 }
1904
1905 Type mt = types.memberType(origin.type, m);
1906 Type ot = types.memberType(origin.type, other);
1907 // Error if overriding result type is different
1908 // (or, in the case of generics mode, not a subtype) of
1909 // overridden result type. We have to rename any type parameters
1910 // before comparing types.
1911 List<Type> mtvars = mt.getTypeArguments();
1912 List<Type> otvars = ot.getTypeArguments();
1913 Type mtres = mt.getReturnType();
1914 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1915
1916 overrideWarner.clear();
1917 boolean resultTypesOK =
1918 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1919 if (!resultTypesOK) {
1920 if ((m.flags() & STATIC) != 0 && (other.flags() & STATIC) != 0) {
1921 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1922 Errors.OverrideIncompatibleRet(Fragments.CantHide(m, m.location(), other,
1923 other.location()), mtres, otres));
1924 m.flags_field |= BAD_OVERRIDE;
1925 } else {
1926 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1927 Errors.OverrideIncompatibleRet(cannotOverride(m, other), mtres, otres));
1928 m.flags_field |= BAD_OVERRIDE;
1929 }
1930 return;
1931 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1932 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1933 LintWarnings.OverrideUncheckedRet(uncheckedOverrides(m, other), mtres, otres));
1934 }
1935
1936 // Error if overriding method throws an exception not reported
1937 // by overridden method.
1938 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1939 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1940 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1941 if (unhandledErased.nonEmpty()) {
1942 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1943 Errors.OverrideMethDoesntThrow(cannotOverride(m, other), unhandledUnerased.head));
1944 m.flags_field |= BAD_OVERRIDE;
1945 return;
1946 }
1947 else if (unhandledUnerased.nonEmpty()) {
1948 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1949 LintWarnings.OverrideUncheckedThrown(cannotOverride(m, other), unhandledUnerased.head));
1950 return;
1951 }
1952
1953 // Optional warning if varargs don't agree
1954 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)) {
1955 lint.logIfEnabled(TreeInfo.diagnosticPositionFor(m, tree),
1956 ((m.flags() & Flags.VARARGS) != 0)
1957 ? LintWarnings.OverrideVarargsMissing(varargsOverrides(m, other))
1958 : LintWarnings.OverrideVarargsExtra(varargsOverrides(m, other)));
1959 }
1960
1961 // Warn if instance method overrides bridge method (compiler spec ??)
1962 if ((other.flags() & BRIDGE) != 0) {
1963 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1964 Warnings.OverrideBridge(uncheckedOverrides(m, other)));
1965 }
1966
1967 // Warn if a deprecated method overridden by a non-deprecated one.
1968 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1969 Lint prevLint = setLint(lint.augment(m));
1970 try {
1971 checkDeprecated(() -> TreeInfo.diagnosticPositionFor(m, tree), m, other);
1972 } finally {
1973 setLint(prevLint);
1974 }
1975 }
1976 }
1977 // where
1978 private boolean shouldCheckPreview(MethodSymbol m, MethodSymbol other, ClassSymbol origin) {
1979 if (m.owner != origin ||
1980 //performance - only do the expensive checks when the overridden method is a Preview API:
1981 ((other.flags() & PREVIEW_API) == 0 &&
1982 (other.owner.flags() & PREVIEW_API) == 0)) {
1983 return false;
1984 }
1985
1986 for (Symbol s : types.membersClosure(origin.type, false).getSymbolsByName(m.name)) {
1987 if (m != s && m.overrides(s, origin, types, false)) {
1988 //only produce preview warnings or errors if "m" immediatelly overrides "other"
1989 //without intermediate overriding methods:
1990 return s == other;
1991 }
1992 }
1993
1994 return false;
1995 }
1996 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1997 // If the method, m, is defined in an interface, then ignore the issue if the method
1998 // is only inherited via a supertype and also implemented in the supertype,
1999 // because in that case, we will rediscover the issue when examining the method
2000 // in the supertype.
2001 // If the method, m, is not defined in an interface, then the only time we need to
2002 // address the issue is when the method is the supertype implementation: any other
2003 // case, we will have dealt with when examining the supertype classes
2004 ClassSymbol mc = m.enclClass();
2005 Type st = types.supertype(origin.type);
2006 if (!st.hasTag(CLASS))
2007 return true;
2008 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
2009
2010 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
2011 List<Type> intfs = types.interfaces(origin.type);
2012 return (intfs.contains(mc.type) ? false : (stimpl != null));
2013 }
2014 else
2015 return (stimpl != m);
2016 }
2017
2018
2019 // used to check if there were any unchecked conversions
2020 Warner overrideWarner = new Warner();
2021
2022 /** Check that a class does not inherit two concrete methods
2023 * with the same signature.
2024 * @param pos Position to be used for error reporting.
2025 * @param site The class type to be checked.
2026 */
2027 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
2028 Type sup = types.supertype(site);
2029 if (!sup.hasTag(CLASS)) return;
2030
2031 for (Type t1 = sup;
2032 t1.hasTag(CLASS) && t1.tsym.type.isParameterized();
2033 t1 = types.supertype(t1)) {
2034 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
2035 if (s1.kind != MTH ||
2036 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
2037 !s1.isInheritedIn(site.tsym, types) ||
2038 ((MethodSymbol)s1).implementation(site.tsym,
2039 types,
2040 true) != s1)
2041 continue;
2042 Type st1 = types.memberType(t1, s1);
2043 int s1ArgsLength = st1.getParameterTypes().length();
2044 if (st1 == s1.type) continue;
2045
2046 for (Type t2 = sup;
2047 t2.hasTag(CLASS);
2048 t2 = types.supertype(t2)) {
2049 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
2050 if (s2 == s1 ||
2051 s2.kind != MTH ||
2052 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
2053 s2.type.getParameterTypes().length() != s1ArgsLength ||
2054 !s2.isInheritedIn(site.tsym, types) ||
2055 ((MethodSymbol)s2).implementation(site.tsym,
2056 types,
2057 true) != s2)
2058 continue;
2059 Type st2 = types.memberType(t2, s2);
2060 if (types.overrideEquivalent(st1, st2))
2061 log.error(pos,
2062 Errors.ConcreteInheritanceConflict(s1, t1, s2, t2, sup));
2063 }
2064 }
2065 }
2066 }
2067 }
2068
2069 /** Check that classes (or interfaces) do not each define an abstract
2070 * method with same name and arguments but incompatible return types.
2071 * @param pos Position to be used for error reporting.
2072 * @param t1 The first argument type.
2073 * @param t2 The second argument type.
2074 */
2075 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
2076 Type t1,
2077 Type t2,
2078 Type site) {
2079 if ((site.tsym.flags() & COMPOUND) != 0) {
2080 // special case for intersections: need to eliminate wildcards in supertypes
2081 t1 = types.capture(t1);
2082 t2 = types.capture(t2);
2083 }
2084 return firstIncompatibility(pos, t1, t2, site) == null;
2085 }
2086
2087 /** Return the first method which is defined with same args
2088 * but different return types in two given interfaces, or null if none
2089 * exists.
2090 * @param t1 The first type.
2091 * @param t2 The second type.
2092 * @param site The most derived type.
2093 * @return symbol from t2 that conflicts with one in t1.
2094 */
2095 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
2096 Map<TypeSymbol,Type> interfaces1 = new HashMap<>();
2097 closure(t1, interfaces1);
2098 Map<TypeSymbol,Type> interfaces2;
2099 if (t1 == t2)
2100 interfaces2 = interfaces1;
2101 else
2102 closure(t2, interfaces1, interfaces2 = new HashMap<>());
2103
2104 for (Type t3 : interfaces1.values()) {
2105 for (Type t4 : interfaces2.values()) {
2106 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
2107 if (s != null) return s;
2108 }
2109 }
2110 return null;
2111 }
2112
2113 /** Compute all the supertypes of t, indexed by type symbol. */
2114 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
2115 if (!t.hasTag(CLASS)) return;
2116 if (typeMap.put(t.tsym, t) == null) {
2117 closure(types.supertype(t), typeMap);
2118 for (Type i : types.interfaces(t))
2119 closure(i, typeMap);
2120 }
2121 }
2122
2123 /** Compute all the supertypes of t, indexed by type symbol (except those in typesSkip). */
2124 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
2125 if (!t.hasTag(CLASS)) return;
2126 if (typesSkip.get(t.tsym) != null) return;
2127 if (typeMap.put(t.tsym, t) == null) {
2128 closure(types.supertype(t), typesSkip, typeMap);
2129 for (Type i : types.interfaces(t))
2130 closure(i, typesSkip, typeMap);
2131 }
2132 }
2133
2134 /** Return the first method in t2 that conflicts with a method from t1. */
2135 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
2136 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
2137 Type st1 = null;
2138 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types) ||
2139 (s1.flags() & SYNTHETIC) != 0) continue;
2140 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
2141 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
2142 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
2143 if (s1 == s2) continue;
2144 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types) ||
2145 (s2.flags() & SYNTHETIC) != 0) continue;
2146 if (st1 == null) st1 = types.memberType(t1, s1);
2147 Type st2 = types.memberType(t2, s2);
2148 if (types.overrideEquivalent(st1, st2)) {
2149 List<Type> tvars1 = st1.getTypeArguments();
2150 List<Type> tvars2 = st2.getTypeArguments();
2151 Type rt1 = st1.getReturnType();
2152 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
2153 boolean compat =
2154 types.isSameType(rt1, rt2) ||
2155 !rt1.isPrimitiveOrVoid() &&
2156 !rt2.isPrimitiveOrVoid() &&
2157 (types.covariantReturnType(rt1, rt2, types.noWarnings) ||
2158 types.covariantReturnType(rt2, rt1, types.noWarnings)) ||
2159 checkCommonOverriderIn(s1,s2,site);
2160 if (!compat) {
2161 if (types.isSameType(t1, t2)) {
2162 log.error(pos, Errors.IncompatibleDiffRetSameType(t1,
2163 s2.name, types.memberType(t2, s2).getParameterTypes()));
2164 } else {
2165 log.error(pos, Errors.TypesIncompatible(t1, t2,
2166 Fragments.IncompatibleDiffRet(s2.name, types.memberType(t2, s2).getParameterTypes())));
2167 }
2168 return s2;
2169 }
2170 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) &&
2171 !checkCommonOverriderIn(s1, s2, site)) {
2172 log.error(pos, Errors.NameClashSameErasureNoOverride(
2173 s1.name, types.memberType(site, s1).asMethodType().getParameterTypes(), s1.location(),
2174 s2.name, types.memberType(site, s2).asMethodType().getParameterTypes(), s2.location()));
2175 return s2;
2176 }
2177 }
2178 }
2179 return null;
2180 }
2181 //WHERE
2182 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
2183 Map<TypeSymbol,Type> supertypes = new HashMap<>();
2184 Type st1 = types.memberType(site, s1);
2185 Type st2 = types.memberType(site, s2);
2186 closure(site, supertypes);
2187 for (Type t : supertypes.values()) {
2188 for (Symbol s3 : t.tsym.members().getSymbolsByName(s1.name)) {
2189 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
2190 Type st3 = types.memberType(site,s3);
2191 if (types.overrideEquivalent(st3, st1) &&
2192 types.overrideEquivalent(st3, st2) &&
2193 types.returnTypeSubstitutable(st3, st1) &&
2194 types.returnTypeSubstitutable(st3, st2)) {
2195 return true;
2196 }
2197 }
2198 }
2199 return false;
2200 }
2201
2202 /** Check that a given method conforms with any method it overrides.
2203 * @param tree The tree from which positions are extracted
2204 * for errors.
2205 * @param m The overriding method.
2206 */
2207 void checkOverride(Env<AttrContext> env, JCMethodDecl tree, MethodSymbol m) {
2208 ClassSymbol origin = (ClassSymbol)m.owner;
2209 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name)) {
2210 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
2211 log.error(tree.pos(), Errors.EnumNoFinalize);
2212 return;
2213 }
2214 }
2215 if (allowValueClasses && origin.isValueClass() && names.finalize.equals(m.name)) {
2216 if (m.overrides(syms.objectFinalize, origin, types, false)) {
2217 log.warning(tree.pos(), Warnings.ValueFinalize);
2218 }
2219 }
2220 if (allowRecords && origin.isRecord()) {
2221 // let's find out if this is a user defined accessor in which case the @Override annotation is acceptable
2222 Optional<? extends RecordComponent> recordComponent = origin.getRecordComponents().stream()
2223 .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
2224 if (recordComponent.isPresent()) {
2225 return;
2226 }
2227 }
2228
2229 for (Type t = origin.type; t.hasTag(CLASS);
2230 t = types.supertype(t)) {
2231 if (t != origin.type) {
2232 checkOverride(tree, t, origin, m);
2233 }
2234 for (Type t2 : types.interfaces(t)) {
2235 checkOverride(tree, t2, origin, m);
2236 }
2237 }
2238
2239 final boolean explicitOverride = m.attribute(syms.overrideType.tsym) != null;
2240 // Check if this method must override a super method due to being annotated with @Override
2241 // or by virtue of being a member of a diamond inferred anonymous class. Latter case is to
2242 // be treated "as if as they were annotated" with @Override.
2243 boolean mustOverride = explicitOverride ||
2244 (env.info.isAnonymousDiamond && !m.isConstructor() && !m.isPrivate());
2245 if (mustOverride && !isOverrider(m)) {
2246 DiagnosticPosition pos = tree.pos();
2247 for (JCAnnotation a : tree.getModifiers().annotations) {
2248 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2249 pos = a.pos();
2250 break;
2251 }
2252 }
2253 log.error(pos,
2254 explicitOverride ? (m.isStatic() ? Errors.StaticMethodsCannotBeAnnotatedWithOverride : Errors.MethodDoesNotOverrideSuperclass) :
2255 Errors.AnonymousDiamondMethodDoesNotOverrideSuperclass(Fragments.DiamondAnonymousMethodsImplicitlyOverride));
2256 }
2257 }
2258
2259 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
2260 TypeSymbol c = site.tsym;
2261 for (Symbol sym : c.members().getSymbolsByName(m.name)) {
2262 if (m.overrides(sym, origin, types, false)) {
2263 if ((sym.flags() & ABSTRACT) == 0) {
2264 checkOverride(tree, m, (MethodSymbol)sym, origin);
2265 }
2266 }
2267 }
2268 }
2269
2270 private Predicate<Symbol> equalsHasCodeFilter = s -> MethodSymbol.implementation_filter.test(s) &&
2271 (s.flags() & BAD_OVERRIDE) == 0;
2272
2273 public void checkClassOverrideEqualsAndHashIfNeeded(DiagnosticPosition pos,
2274 ClassSymbol someClass) {
2275 /* At present, annotations cannot possibly have a method that is override
2276 * equivalent with Object.equals(Object) but in any case the condition is
2277 * fine for completeness.
2278 */
2279 if (someClass == (ClassSymbol)syms.objectType.tsym ||
2280 someClass.isInterface() || someClass.isEnum() ||
2281 (someClass.flags() & ANNOTATION) != 0 ||
2282 (someClass.flags() & ABSTRACT) != 0) return;
2283 //anonymous inner classes implementing interfaces need especial treatment
2284 if (someClass.isAnonymous()) {
2285 List<Type> interfaces = types.interfaces(someClass.type);
2286 if (interfaces != null && !interfaces.isEmpty() &&
2287 interfaces.head.tsym == syms.comparatorType.tsym) return;
2288 }
2289 checkClassOverrideEqualsAndHash(pos, someClass);
2290 }
2291
2292 private void checkClassOverrideEqualsAndHash(DiagnosticPosition pos,
2293 ClassSymbol someClass) {
2294 if (lint.isEnabled(LintCategory.OVERRIDES)) {
2295 MethodSymbol equalsAtObject = (MethodSymbol)syms.objectType
2296 .tsym.members().findFirst(names.equals);
2297 MethodSymbol hashCodeAtObject = (MethodSymbol)syms.objectType
2298 .tsym.members().findFirst(names.hashCode);
2299 MethodSymbol equalsImpl = types.implementation(equalsAtObject,
2300 someClass, false, equalsHasCodeFilter);
2301 boolean overridesEquals = equalsImpl != null &&
2302 equalsImpl.owner == someClass;
2303 boolean overridesHashCode = types.implementation(hashCodeAtObject,
2304 someClass, false, equalsHasCodeFilter) != hashCodeAtObject;
2305
2306 if (overridesEquals && !overridesHashCode) {
2307 log.warning(pos,
2308 LintWarnings.OverrideEqualsButNotHashcode(someClass));
2309 }
2310 }
2311 }
2312
2313 public void checkHasMain(DiagnosticPosition pos, ClassSymbol c) {
2314 boolean found = false;
2315
2316 for (Symbol sym : c.members().getSymbolsByName(names.main)) {
2317 if (sym.kind == MTH && (sym.flags() & PRIVATE) == 0) {
2318 MethodSymbol meth = (MethodSymbol)sym;
2319 if (!types.isSameType(meth.getReturnType(), syms.voidType)) {
2320 continue;
2321 }
2322 if (meth.params.isEmpty()) {
2323 found = true;
2324 break;
2325 }
2326 if (meth.params.size() != 1) {
2327 continue;
2328 }
2329 if (!types.isSameType(meth.params.head.type, types.makeArrayType(syms.stringType))) {
2330 continue;
2331 }
2332
2333 found = true;
2334 break;
2335 }
2336 }
2337
2338 if (!found) {
2339 log.error(pos, Errors.ImplicitClassDoesNotHaveMainMethod);
2340 }
2341 }
2342
2343 public void checkModuleName (JCModuleDecl tree) {
2344 Name moduleName = tree.sym.name;
2345 Assert.checkNonNull(moduleName);
2346 if (lint.isEnabled(LintCategory.MODULE)) {
2347 JCExpression qualId = tree.qualId;
2348 while (qualId != null) {
2349 Name componentName;
2350 DiagnosticPosition pos;
2351 switch (qualId.getTag()) {
2352 case SELECT:
2353 JCFieldAccess selectNode = ((JCFieldAccess) qualId);
2354 componentName = selectNode.name;
2355 pos = selectNode.pos();
2356 qualId = selectNode.selected;
2357 break;
2358 case IDENT:
2359 componentName = ((JCIdent) qualId).name;
2360 pos = qualId.pos();
2361 qualId = null;
2362 break;
2363 default:
2364 throw new AssertionError("Unexpected qualified identifier: " + qualId.toString());
2365 }
2366 if (componentName != null) {
2367 String moduleNameComponentString = componentName.toString();
2368 int nameLength = moduleNameComponentString.length();
2369 if (nameLength > 0 && Character.isDigit(moduleNameComponentString.charAt(nameLength - 1))) {
2370 log.warning(pos, LintWarnings.PoorChoiceForModuleName(componentName));
2371 }
2372 }
2373 }
2374 }
2375 }
2376
2377 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
2378 ClashFilter cf = new ClashFilter(origin.type);
2379 return (cf.test(s1) &&
2380 cf.test(s2) &&
2381 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
2382 }
2383
2384
2385 /** Check that all abstract members of given class have definitions.
2386 * @param pos Position to be used for error reporting.
2387 * @param c The class.
2388 */
2389 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
2390 MethodSymbol undef = types.firstUnimplementedAbstract(c);
2391 if (undef != null) {
2392 MethodSymbol undef1 =
2393 new MethodSymbol(undef.flags(), undef.name,
2394 types.memberType(c.type, undef), undef.owner);
2395 log.error(pos,
2396 Errors.DoesNotOverrideAbstract(c, undef1, undef1.location()));
2397 }
2398 }
2399
2400 void checkNonCyclicDecl(JCClassDecl tree) {
2401 CycleChecker cc = new CycleChecker();
2402 cc.scan(tree);
2403 if (!cc.errorFound && !cc.partialCheck) {
2404 tree.sym.flags_field |= ACYCLIC;
2405 }
2406 }
2407
2408 class CycleChecker extends TreeScanner {
2409
2410 Set<Symbol> seenClasses = new HashSet<>();
2411 boolean errorFound = false;
2412 boolean partialCheck = false;
2413
2414 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
2415 if (sym != null && sym.kind == TYP) {
2416 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
2417 if (classEnv != null) {
2418 DiagnosticSource prevSource = log.currentSource();
2419 try {
2420 log.useSource(classEnv.toplevel.sourcefile);
2421 scan(classEnv.tree);
2422 }
2423 finally {
2424 log.useSource(prevSource.getFile());
2425 }
2426 } else if (sym.kind == TYP) {
2427 checkClass(pos, sym, List.nil());
2428 }
2429 } else if (sym == null || sym.kind != PCK) {
2430 //not completed yet
2431 partialCheck = true;
2432 }
2433 }
2434
2435 @Override
2436 public void visitSelect(JCFieldAccess tree) {
2437 super.visitSelect(tree);
2438 checkSymbol(tree.pos(), tree.sym);
2439 }
2440
2441 @Override
2442 public void visitIdent(JCIdent tree) {
2443 checkSymbol(tree.pos(), tree.sym);
2444 }
2445
2446 @Override
2447 public void visitTypeApply(JCTypeApply tree) {
2448 scan(tree.clazz);
2449 }
2450
2451 @Override
2452 public void visitTypeArray(JCArrayTypeTree tree) {
2453 scan(tree.elemtype);
2454 }
2455
2456 @Override
2457 public void visitClassDef(JCClassDecl tree) {
2458 List<JCTree> supertypes = List.nil();
2459 if (tree.getExtendsClause() != null) {
2460 supertypes = supertypes.prepend(tree.getExtendsClause());
2461 }
2462 if (tree.getImplementsClause() != null) {
2463 for (JCTree intf : tree.getImplementsClause()) {
2464 supertypes = supertypes.prepend(intf);
2465 }
2466 }
2467 checkClass(tree.pos(), tree.sym, supertypes);
2468 }
2469
2470 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
2471 if ((c.flags_field & ACYCLIC) != 0)
2472 return;
2473 if (seenClasses.contains(c)) {
2474 errorFound = true;
2475 log.error(pos, Errors.CyclicInheritance(c));
2476 seenClasses.stream()
2477 .filter(s -> !s.type.isErroneous())
2478 .filter(ClassSymbol.class::isInstance)
2479 .map(ClassSymbol.class::cast)
2480 .forEach(Check.this::handleCyclic);
2481 } else if (!c.type.isErroneous()) {
2482 try {
2483 seenClasses.add(c);
2484 if (c.type.hasTag(CLASS)) {
2485 if (supertypes.nonEmpty()) {
2486 scan(supertypes);
2487 }
2488 else {
2489 ClassType ct = (ClassType)c.type;
2490 if (ct.supertype_field == null ||
2491 ct.interfaces_field == null) {
2492 //not completed yet
2493 partialCheck = true;
2494 return;
2495 }
2496 checkSymbol(pos, ct.supertype_field.tsym);
2497 for (Type intf : ct.interfaces_field) {
2498 checkSymbol(pos, intf.tsym);
2499 }
2500 }
2501 if (c.owner.kind == TYP) {
2502 checkSymbol(pos, c.owner);
2503 }
2504 }
2505 } finally {
2506 seenClasses.remove(c);
2507 }
2508 }
2509 }
2510 }
2511
2512 /** Check for cyclic references. Issue an error if the
2513 * symbol of the type referred to has a LOCKED flag set.
2514 *
2515 * @param pos Position to be used for error reporting.
2516 * @param t The type referred to.
2517 */
2518 void checkNonCyclic(DiagnosticPosition pos, Type t) {
2519 checkNonCyclicInternal(pos, t);
2520 }
2521
2522
2523 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
2524 checkNonCyclic1(pos, t, List.nil());
2525 }
2526
2527 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
2528 final TypeVar tv;
2529 if (t.hasTag(TYPEVAR) && (t.tsym.flags() & UNATTRIBUTED) != 0)
2530 return;
2531 if (seen.contains(t)) {
2532 tv = (TypeVar)t;
2533 tv.setUpperBound(types.createErrorType(t));
2534 log.error(pos, Errors.CyclicInheritance(t));
2535 } else if (t.hasTag(TYPEVAR)) {
2536 tv = (TypeVar)t;
2537 seen = seen.prepend(tv);
2538 for (Type b : types.getBounds(tv))
2539 checkNonCyclic1(pos, b, seen);
2540 }
2541 }
2542
2543 /** Check for cyclic references. Issue an error if the
2544 * symbol of the type referred to has a LOCKED flag set.
2545 *
2546 * @param pos Position to be used for error reporting.
2547 * @param t The type referred to.
2548 * @return True if the check completed on all attributed classes
2549 */
2550 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
2551 boolean complete = true; // was the check complete?
2552 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
2553 Symbol c = t.tsym;
2554 if ((c.flags_field & ACYCLIC) != 0) return true;
2555
2556 if ((c.flags_field & LOCKED) != 0) {
2557 log.error(pos, Errors.CyclicInheritance(c));
2558 handleCyclic((ClassSymbol)c);
2559 } else if (!c.type.isErroneous()) {
2560 try {
2561 c.flags_field |= LOCKED;
2562 if (c.type.hasTag(CLASS)) {
2563 ClassType clazz = (ClassType)c.type;
2564 if (clazz.interfaces_field != null)
2565 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
2566 complete &= checkNonCyclicInternal(pos, l.head);
2567 if (clazz.supertype_field != null) {
2568 Type st = clazz.supertype_field;
2569 if (st != null && st.hasTag(CLASS))
2570 complete &= checkNonCyclicInternal(pos, st);
2571 }
2572 if (c.owner.kind == TYP)
2573 complete &= checkNonCyclicInternal(pos, c.owner.type);
2574 }
2575 } finally {
2576 c.flags_field &= ~LOCKED;
2577 }
2578 }
2579 if (complete)
2580 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.isCompleted();
2581 if (complete) c.flags_field |= ACYCLIC;
2582 return complete;
2583 }
2584
2585 /** Handle finding an inheritance cycle on a class by setting
2586 * the class' and its supertypes' types to the error type.
2587 **/
2588 private void handleCyclic(ClassSymbol c) {
2589 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2590 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2591 Type st = types.supertype(c.type);
2592 if (st.hasTag(CLASS))
2593 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2594 c.type = types.createErrorType(c, c.type);
2595 c.flags_field |= ACYCLIC;
2596 }
2597
2598 /** Check that all methods which implement some
2599 * method conform to the method they implement.
2600 * @param tree The class definition whose members are checked.
2601 */
2602 void checkImplementations(JCClassDecl tree) {
2603 checkImplementations(tree, tree.sym, tree.sym);
2604 }
2605 //where
2606 /** Check that all methods which implement some
2607 * method in `ic' conform to the method they implement.
2608 */
2609 void checkImplementations(JCTree tree, ClassSymbol origin, ClassSymbol ic) {
2610 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2611 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2612 if ((lc.flags() & ABSTRACT) != 0) {
2613 for (Symbol sym : lc.members().getSymbols(NON_RECURSIVE)) {
2614 if (sym.kind == MTH &&
2615 (sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2616 MethodSymbol absmeth = (MethodSymbol)sym;
2617 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2618 if (implmeth != null && implmeth != absmeth &&
2619 (implmeth.owner.flags() & INTERFACE) ==
2620 (origin.flags() & INTERFACE)) {
2621 // don't check if implmeth is in a class, yet
2622 // origin is an interface. This case arises only
2623 // if implmeth is declared in Object. The reason is
2624 // that interfaces really don't inherit from
2625 // Object it's just that the compiler represents
2626 // things that way.
2627 checkOverride(tree, implmeth, absmeth, origin);
2628 }
2629 }
2630 }
2631 }
2632 }
2633 }
2634
2635 /** Check that all abstract methods implemented by a class are
2636 * mutually compatible.
2637 * @param pos Position to be used for error reporting.
2638 * @param c The class whose interfaces are checked.
2639 */
2640 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2641 List<Type> supertypes = types.interfaces(c);
2642 Type supertype = types.supertype(c);
2643 if (supertype.hasTag(CLASS) &&
2644 (supertype.tsym.flags() & ABSTRACT) != 0)
2645 supertypes = supertypes.prepend(supertype);
2646 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2647 if (!l.head.getTypeArguments().isEmpty() &&
2648 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2649 return;
2650 for (List<Type> m = supertypes; m != l; m = m.tail)
2651 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2652 return;
2653 }
2654 checkCompatibleConcretes(pos, c);
2655
2656 Type identitySuper = null;
2657 for (Type t : types.closure(c)) {
2658 if (t != c) {
2659 if (t.isIdentityClass() && (t.tsym.flags() & VALUE_BASED) == 0)
2660 identitySuper = t;
2661 if (c.isValueClass() && identitySuper != null && identitySuper.tsym != syms.objectType.tsym) { // Object is special
2662 log.error(pos, Errors.ValueTypeHasIdentitySuperType(c, identitySuper));
2663 break;
2664 }
2665 }
2666 }
2667 }
2668
2669 /** Check that all non-override equivalent methods accessible from 'site'
2670 * are mutually compatible (JLS 8.4.8/9.4.1).
2671 *
2672 * @param pos Position to be used for error reporting.
2673 * @param site The class whose methods are checked.
2674 * @param sym The method symbol to be checked.
2675 */
2676 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2677 ClashFilter cf = new ClashFilter(site);
2678 //for each method m1 that is overridden (directly or indirectly)
2679 //by method 'sym' in 'site'...
2680
2681 ArrayList<Symbol> symbolsByName = new ArrayList<>();
2682 types.membersClosure(site, false).getSymbolsByName(sym.name, cf).forEach(symbolsByName::add);
2683 for (Symbol m1 : symbolsByName) {
2684 if (!sym.overrides(m1, site.tsym, types, false)) {
2685 continue;
2686 }
2687
2688 //...check each method m2 that is a member of 'site'
2689 for (Symbol m2 : symbolsByName) {
2690 if (m2 == m1) continue;
2691 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2692 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2693 if (!types.isSubSignature(sym.type, types.memberType(site, m2)) &&
2694 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) {
2695 sym.flags_field |= CLASH;
2696 if (m1 == sym) {
2697 log.error(pos, Errors.NameClashSameErasureNoOverride(
2698 m1.name, types.memberType(site, m1).asMethodType().getParameterTypes(), m1.location(),
2699 m2.name, types.memberType(site, m2).asMethodType().getParameterTypes(), m2.location()));
2700 } else {
2701 ClassType ct = (ClassType)site;
2702 String kind = ct.isInterface() ? "interface" : "class";
2703 log.error(pos, Errors.NameClashSameErasureNoOverride1(
2704 kind,
2705 ct.tsym.name,
2706 m1.name,
2707 types.memberType(site, m1).asMethodType().getParameterTypes(),
2708 m1.location(),
2709 m2.name,
2710 types.memberType(site, m2).asMethodType().getParameterTypes(),
2711 m2.location()));
2712 }
2713 return;
2714 }
2715 }
2716 }
2717 }
2718
2719 /** Check that all static methods accessible from 'site' are
2720 * mutually compatible (JLS 8.4.8).
2721 *
2722 * @param pos Position to be used for error reporting.
2723 * @param site The class whose methods are checked.
2724 * @param sym The method symbol to be checked.
2725 */
2726 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2727 ClashFilter cf = new ClashFilter(site);
2728 //for each method m1 that is a member of 'site'...
2729 for (Symbol s : types.membersClosure(site, true).getSymbolsByName(sym.name, cf)) {
2730 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2731 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2732 if (!types.isSubSignature(sym.type, types.memberType(site, s))) {
2733 if (types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2734 log.error(pos,
2735 Errors.NameClashSameErasureNoHide(sym, sym.location(), s, s.location()));
2736 return;
2737 }
2738 }
2739 }
2740 }
2741
2742 //where
2743 private class ClashFilter implements Predicate<Symbol> {
2744
2745 Type site;
2746
2747 ClashFilter(Type site) {
2748 this.site = site;
2749 }
2750
2751 boolean shouldSkip(Symbol s) {
2752 return (s.flags() & CLASH) != 0 &&
2753 s.owner == site.tsym;
2754 }
2755
2756 @Override
2757 public boolean test(Symbol s) {
2758 return s.kind == MTH &&
2759 (s.flags() & SYNTHETIC) == 0 &&
2760 !shouldSkip(s) &&
2761 s.isInheritedIn(site.tsym, types) &&
2762 !s.isConstructor();
2763 }
2764 }
2765
2766 void checkDefaultMethodClashes(DiagnosticPosition pos, Type site) {
2767 DefaultMethodClashFilter dcf = new DefaultMethodClashFilter(site);
2768 for (Symbol m : types.membersClosure(site, false).getSymbols(dcf)) {
2769 Assert.check(m.kind == MTH);
2770 List<MethodSymbol> prov = types.interfaceCandidates(site, (MethodSymbol)m);
2771 if (prov.size() > 1) {
2772 ListBuffer<Symbol> abstracts = new ListBuffer<>();
2773 ListBuffer<Symbol> defaults = new ListBuffer<>();
2774 for (MethodSymbol provSym : prov) {
2775 if ((provSym.flags() & DEFAULT) != 0) {
2776 defaults = defaults.append(provSym);
2777 } else if ((provSym.flags() & ABSTRACT) != 0) {
2778 abstracts = abstracts.append(provSym);
2779 }
2780 if (defaults.nonEmpty() && defaults.size() + abstracts.size() >= 2) {
2781 //strong semantics - issue an error if two sibling interfaces
2782 //have two override-equivalent defaults - or if one is abstract
2783 //and the other is default
2784 Fragment diagKey;
2785 Symbol s1 = defaults.first();
2786 Symbol s2;
2787 if (defaults.size() > 1) {
2788 s2 = defaults.toList().tail.head;
2789 diagKey = Fragments.IncompatibleUnrelatedDefaults(Kinds.kindName(site.tsym), site,
2790 m.name, types.memberType(site, m).getParameterTypes(),
2791 s1.location(), s2.location());
2792
2793 } else {
2794 s2 = abstracts.first();
2795 diagKey = Fragments.IncompatibleAbstractDefault(Kinds.kindName(site.tsym), site,
2796 m.name, types.memberType(site, m).getParameterTypes(),
2797 s1.location(), s2.location());
2798 }
2799 log.error(pos, Errors.TypesIncompatible(s1.location().type, s2.location().type, diagKey));
2800 break;
2801 }
2802 }
2803 }
2804 }
2805 }
2806
2807 //where
2808 private class DefaultMethodClashFilter implements Predicate<Symbol> {
2809
2810 Type site;
2811
2812 DefaultMethodClashFilter(Type site) {
2813 this.site = site;
2814 }
2815
2816 @Override
2817 public boolean test(Symbol s) {
2818 return s.kind == MTH &&
2819 (s.flags() & DEFAULT) != 0 &&
2820 s.isInheritedIn(site.tsym, types) &&
2821 !s.isConstructor();
2822 }
2823 }
2824
2825 /** Report warnings for potentially ambiguous method declarations in the given site. */
2826 void checkPotentiallyAmbiguousOverloads(JCClassDecl tree, Type site) {
2827
2828 // Skip if warning not enabled
2829 if (!lint.isEnabled(LintCategory.OVERLOADS))
2830 return;
2831
2832 // Gather all of site's methods, including overridden methods, grouped by name (except Object methods)
2833 List<java.util.List<MethodSymbol>> methodGroups = methodsGroupedByName(site,
2834 new PotentiallyAmbiguousFilter(site), ArrayList::new);
2835
2836 // Build the predicate that determines if site is responsible for an ambiguity
2837 BiPredicate<MethodSymbol, MethodSymbol> responsible = buildResponsiblePredicate(site, methodGroups);
2838
2839 // Now remove overridden methods from each group, leaving only site's actual members
2840 methodGroups.forEach(list -> removePreempted(list, (m1, m2) -> m1.overrides(m2, site.tsym, types, false)));
2841
2842 // Allow site's own declared methods (only) to apply @SuppressWarnings("overloads")
2843 methodGroups.forEach(list -> list.removeIf(
2844 m -> m.owner == site.tsym && !lint.augment(m).isEnabled(LintCategory.OVERLOADS)));
2845
2846 // Warn about ambiguous overload method pairs for which site is responsible
2847 methodGroups.forEach(list -> compareAndRemove(list, (m1, m2) -> {
2848
2849 // See if this is an ambiguous overload for which "site" is responsible
2850 if (!potentiallyAmbiguousOverload(site, m1, m2) || !responsible.test(m1, m2))
2851 return 0;
2852
2853 // Locate the warning at one of the methods, if possible
2854 DiagnosticPosition pos =
2855 m1.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m1, tree) :
2856 m2.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m2, tree) :
2857 tree.pos();
2858
2859 // Log the warning
2860 log.warning(pos,
2861 LintWarnings.PotentiallyAmbiguousOverload(
2862 m1.asMemberOf(site, types), m1.location(),
2863 m2.asMemberOf(site, types), m2.location()));
2864
2865 // Don't warn again for either of these two methods
2866 return FIRST | SECOND;
2867 }));
2868 }
2869
2870 /** Build a predicate that determines, given two methods that are members of the given class,
2871 * whether the class should be held "responsible" if the methods are potentially ambiguous.
2872 *
2873 * Sometimes ambiguous methods are unavoidable because they're inherited from a supertype.
2874 * For example, any subtype of Spliterator.OfInt will have ambiguities for both
2875 * forEachRemaining() and tryAdvance() (in both cases the overloads are IntConsumer and
2876 * Consumer<? super Integer>). So we only want to "blame" a class when that class is
2877 * itself responsible for creating the ambiguity. We declare that a class C is "responsible"
2878 * for the ambiguity between two methods m1 and m2 if there is no direct supertype T of C
2879 * such that m1 and m2, or some overrides thereof, both exist in T and are ambiguous in T.
2880 * As an optimization, we first check if either method is declared in C and does not override
2881 * any other methods; in this case the class is definitely responsible.
2882 */
2883 BiPredicate<MethodSymbol, MethodSymbol> buildResponsiblePredicate(Type site,
2884 List<? extends Collection<MethodSymbol>> methodGroups) {
2885
2886 // Define the "overrides" predicate
2887 BiPredicate<MethodSymbol, MethodSymbol> overrides = (m1, m2) -> m1.overrides(m2, site.tsym, types, false);
2888
2889 // Map each method declared in site to a list of the supertype method(s) it directly overrides
2890 HashMap<MethodSymbol, ArrayList<MethodSymbol>> overriddenMethodsMap = new HashMap<>();
2891 methodGroups.forEach(list -> {
2892 for (MethodSymbol m : list) {
2893
2894 // Skip methods not declared in site
2895 if (m.owner != site.tsym)
2896 continue;
2897
2898 // Gather all supertype methods overridden by m, directly or indirectly
2899 ArrayList<MethodSymbol> overriddenMethods = list.stream()
2900 .filter(m2 -> m2 != m && overrides.test(m, m2))
2901 .collect(Collectors.toCollection(ArrayList::new));
2902
2903 // Eliminate non-direct overrides
2904 removePreempted(overriddenMethods, overrides);
2905
2906 // Add to map
2907 overriddenMethodsMap.put(m, overriddenMethods);
2908 }
2909 });
2910
2911 // Build the predicate
2912 return (m1, m2) -> {
2913
2914 // Get corresponding supertype methods (if declared in site)
2915 java.util.List<MethodSymbol> overriddenMethods1 = overriddenMethodsMap.get(m1);
2916 java.util.List<MethodSymbol> overriddenMethods2 = overriddenMethodsMap.get(m2);
2917
2918 // Quick check for the case where a method was added by site itself
2919 if (overriddenMethods1 != null && overriddenMethods1.isEmpty())
2920 return true;
2921 if (overriddenMethods2 != null && overriddenMethods2.isEmpty())
2922 return true;
2923
2924 // Get each method's corresponding method(s) from supertypes of site
2925 java.util.List<MethodSymbol> supertypeMethods1 = overriddenMethods1 != null ?
2926 overriddenMethods1 : Collections.singletonList(m1);
2927 java.util.List<MethodSymbol> supertypeMethods2 = overriddenMethods2 != null ?
2928 overriddenMethods2 : Collections.singletonList(m2);
2929
2930 // See if we can blame some direct supertype instead
2931 return types.directSupertypes(site).stream()
2932 .filter(stype -> stype != syms.objectType)
2933 .map(stype -> stype.tsym.type) // view supertype in its original form
2934 .noneMatch(stype -> {
2935 for (MethodSymbol sm1 : supertypeMethods1) {
2936 if (!types.isSubtype(types.erasure(stype), types.erasure(sm1.owner.type)))
2937 continue;
2938 for (MethodSymbol sm2 : supertypeMethods2) {
2939 if (!types.isSubtype(types.erasure(stype), types.erasure(sm2.owner.type)))
2940 continue;
2941 if (potentiallyAmbiguousOverload(stype, sm1, sm2))
2942 return true;
2943 }
2944 }
2945 return false;
2946 });
2947 };
2948 }
2949
2950 /** Gather all of site's methods, including overridden methods, grouped and sorted by name,
2951 * after applying the given filter.
2952 */
2953 <C extends Collection<MethodSymbol>> List<C> methodsGroupedByName(Type site,
2954 Predicate<Symbol> filter, Supplier<? extends C> groupMaker) {
2955 Iterable<Symbol> symbols = types.membersClosure(site, false).getSymbols(filter, RECURSIVE);
2956 return StreamSupport.stream(symbols.spliterator(), false)
2957 .map(MethodSymbol.class::cast)
2958 .collect(Collectors.groupingBy(m -> m.name, Collectors.toCollection(groupMaker)))
2959 .entrySet()
2960 .stream()
2961 .sorted(Comparator.comparing(e -> e.getKey().toString()))
2962 .map(Map.Entry::getValue)
2963 .collect(List.collector());
2964 }
2965
2966 /** Compare elements in a list pair-wise in order to remove some of them.
2967 * @param list mutable list of items
2968 * @param comparer returns flag bit(s) to remove FIRST and/or SECOND
2969 */
2970 <T> void compareAndRemove(java.util.List<T> list, ToIntBiFunction<? super T, ? super T> comparer) {
2971 for (int index1 = 0; index1 < list.size() - 1; index1++) {
2972 T item1 = list.get(index1);
2973 for (int index2 = index1 + 1; index2 < list.size(); index2++) {
2974 T item2 = list.get(index2);
2975 int flags = comparer.applyAsInt(item1, item2);
2976 if ((flags & SECOND) != 0)
2977 list.remove(index2--); // remove item2
2978 if ((flags & FIRST) != 0) {
2979 list.remove(index1--); // remove item1
2980 break;
2981 }
2982 }
2983 }
2984 }
2985
2986 /** Remove elements in a list that are preempted by some other element in the list.
2987 * @param list mutable list of items
2988 * @param preempts decides if one item preempts another, causing the second one to be removed
2989 */
2990 <T> void removePreempted(java.util.List<T> list, BiPredicate<? super T, ? super T> preempts) {
2991 compareAndRemove(list, (item1, item2) -> {
2992 int flags = 0;
2993 if (preempts.test(item1, item2))
2994 flags |= SECOND;
2995 if (preempts.test(item2, item1))
2996 flags |= FIRST;
2997 return flags;
2998 });
2999 }
3000
3001 /** Filters method candidates for the "potentially ambiguous method" check */
3002 class PotentiallyAmbiguousFilter extends ClashFilter {
3003
3004 PotentiallyAmbiguousFilter(Type site) {
3005 super(site);
3006 }
3007
3008 @Override
3009 boolean shouldSkip(Symbol s) {
3010 return s.owner.type.tsym == syms.objectType.tsym || super.shouldSkip(s);
3011 }
3012 }
3013
3014 /**
3015 * Report warnings for potentially ambiguous method declarations. Two declarations
3016 * are potentially ambiguous if they feature two unrelated functional interface
3017 * in same argument position (in which case, a call site passing an implicit
3018 * lambda would be ambiguous). This assumes they already have the same name.
3019 */
3020 boolean potentiallyAmbiguousOverload(Type site, MethodSymbol msym1, MethodSymbol msym2) {
3021 Assert.check(msym1.name == msym2.name);
3022 if (msym1 == msym2)
3023 return false;
3024 Type mt1 = types.memberType(site, msym1);
3025 Type mt2 = types.memberType(site, msym2);
3026 //if both generic methods, adjust type variables
3027 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL) &&
3028 types.hasSameBounds((ForAll)mt1, (ForAll)mt2)) {
3029 mt2 = types.subst(mt2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
3030 }
3031 //expand varargs methods if needed
3032 int maxLength = Math.max(mt1.getParameterTypes().length(), mt2.getParameterTypes().length());
3033 List<Type> args1 = rs.adjustArgs(mt1.getParameterTypes(), msym1, maxLength, true);
3034 List<Type> args2 = rs.adjustArgs(mt2.getParameterTypes(), msym2, maxLength, true);
3035 //if arities don't match, exit
3036 if (args1.length() != args2.length())
3037 return false;
3038 boolean potentiallyAmbiguous = false;
3039 while (args1.nonEmpty() && args2.nonEmpty()) {
3040 Type s = args1.head;
3041 Type t = args2.head;
3042 if (!types.isSubtype(t, s) && !types.isSubtype(s, t)) {
3043 if (types.isFunctionalInterface(s) && types.isFunctionalInterface(t) &&
3044 types.findDescriptorType(s).getParameterTypes().length() > 0 &&
3045 types.findDescriptorType(s).getParameterTypes().length() ==
3046 types.findDescriptorType(t).getParameterTypes().length()) {
3047 potentiallyAmbiguous = true;
3048 } else {
3049 return false;
3050 }
3051 }
3052 args1 = args1.tail;
3053 args2 = args2.tail;
3054 }
3055 return potentiallyAmbiguous;
3056 }
3057
3058 // Apply special flag "-XDwarnOnAccessToMembers" which turns on just this particular warning for all types of access
3059 void checkAccessFromSerializableElement(final JCTree tree, boolean isLambda) {
3060 final Lint prevLint = setLint(warnOnAnyAccessToMembers ? lint.enable(LintCategory.SERIAL) : lint);
3061 try {
3062 if (warnOnAnyAccessToMembers || isLambda)
3063 checkAccessFromSerializableElementInner(tree, isLambda);
3064 } finally {
3065 setLint(prevLint);
3066 }
3067 }
3068
3069 private void checkAccessFromSerializableElementInner(final JCTree tree, boolean isLambda) {
3070 if (lint.isEnabled(LintCategory.SERIAL)) {
3071 Symbol sym = TreeInfo.symbol(tree);
3072 if (!sym.kind.matches(KindSelector.VAL_MTH)) {
3073 return;
3074 }
3075
3076 if (sym.kind == VAR) {
3077 if ((sym.flags() & PARAMETER) != 0 ||
3078 sym.isDirectlyOrIndirectlyLocal() ||
3079 sym.name == names._this ||
3080 sym.name == names._super) {
3081 return;
3082 }
3083 }
3084
3085 if (!types.isSubtype(sym.owner.type, syms.serializableType) &&
3086 isEffectivelyNonPublic(sym)) {
3087 if (isLambda) {
3088 if (belongsToRestrictedPackage(sym)) {
3089 log.warning(tree.pos(),
3090 LintWarnings.AccessToMemberFromSerializableLambda(sym));
3091 }
3092 } else {
3093 log.warning(tree.pos(),
3094 LintWarnings.AccessToMemberFromSerializableElement(sym));
3095 }
3096 }
3097 }
3098 }
3099
3100 private boolean isEffectivelyNonPublic(Symbol sym) {
3101 if (sym.packge() == syms.rootPackage) {
3102 return false;
3103 }
3104
3105 while (sym.kind != PCK) {
3106 if ((sym.flags() & PUBLIC) == 0) {
3107 return true;
3108 }
3109 sym = sym.owner;
3110 }
3111 return false;
3112 }
3113
3114 private boolean belongsToRestrictedPackage(Symbol sym) {
3115 String fullName = sym.packge().fullname.toString();
3116 return fullName.startsWith("java.") ||
3117 fullName.startsWith("javax.") ||
3118 fullName.startsWith("sun.") ||
3119 fullName.contains(".internal.");
3120 }
3121
3122 /** Check that class c does not implement directly or indirectly
3123 * the same parameterized interface with two different argument lists.
3124 * @param pos Position to be used for error reporting.
3125 * @param type The type whose interfaces are checked.
3126 */
3127 void checkClassBounds(DiagnosticPosition pos, Type type) {
3128 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
3129 }
3130 //where
3131 /** Enter all interfaces of type `type' into the hash table `seensofar'
3132 * with their class symbol as key and their type as value. Make
3133 * sure no class is entered with two different types.
3134 */
3135 void checkClassBounds(DiagnosticPosition pos,
3136 Map<TypeSymbol,Type> seensofar,
3137 Type type) {
3138 if (type.isErroneous()) return;
3139 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
3140 Type it = l.head;
3141 if (type.hasTag(CLASS) && !it.hasTag(CLASS)) continue; // JLS 8.1.5
3142
3143 Type oldit = seensofar.put(it.tsym, it);
3144 if (oldit != null) {
3145 List<Type> oldparams = oldit.allparams();
3146 List<Type> newparams = it.allparams();
3147 if (!types.containsTypeEquivalent(oldparams, newparams))
3148 log.error(pos,
3149 Errors.CantInheritDiffArg(it.tsym,
3150 Type.toString(oldparams),
3151 Type.toString(newparams)));
3152 }
3153 checkClassBounds(pos, seensofar, it);
3154 }
3155 Type st = types.supertype(type);
3156 if (type.hasTag(CLASS) && !st.hasTag(CLASS)) return; // JLS 8.1.4
3157 if (st != Type.noType) checkClassBounds(pos, seensofar, st);
3158 }
3159
3160 /** Enter interface into into set.
3161 * If it existed already, issue a "repeated interface" error.
3162 */
3163 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Symbol> its) {
3164 if (its.contains(it.tsym))
3165 log.error(pos, Errors.RepeatedInterface);
3166 else {
3167 its.add(it.tsym);
3168 }
3169 }
3170
3171 /* *************************************************************************
3172 * Check annotations
3173 **************************************************************************/
3174
3175 /**
3176 * Recursively validate annotations values
3177 */
3178 void validateAnnotationTree(JCTree tree) {
3179 class AnnotationValidator extends TreeScanner {
3180 @Override
3181 public void visitAnnotation(JCAnnotation tree) {
3182 if (!tree.type.isErroneous() && tree.type.tsym.isAnnotationType()) {
3183 super.visitAnnotation(tree);
3184 validateAnnotation(tree);
3185 }
3186 }
3187 }
3188 tree.accept(new AnnotationValidator());
3189 }
3190
3191 /**
3192 * {@literal
3193 * Annotation types are restricted to primitives, String, an
3194 * enum, an annotation, Class, Class<?>, Class<? extends
3195 * Anything>, arrays of the preceding.
3196 * }
3197 */
3198 void validateAnnotationType(JCTree restype) {
3199 // restype may be null if an error occurred, so don't bother validating it
3200 if (restype != null) {
3201 validateAnnotationType(restype.pos(), restype.type);
3202 }
3203 }
3204
3205 void validateAnnotationType(DiagnosticPosition pos, Type type) {
3206 if (type.isPrimitive()) return;
3207 if (types.isSameType(type, syms.stringType)) return;
3208 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
3209 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
3210 if (types.cvarLowerBound(type).tsym == syms.classType.tsym) return;
3211 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
3212 validateAnnotationType(pos, types.elemtype(type));
3213 return;
3214 }
3215 log.error(pos, Errors.InvalidAnnotationMemberType);
3216 }
3217
3218 /**
3219 * "It is also a compile-time error if any method declared in an
3220 * annotation type has a signature that is override-equivalent to
3221 * that of any public or protected method declared in class Object
3222 * or in the interface annotation.Annotation."
3223 *
3224 * @jls 9.6 Annotation Types
3225 */
3226 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
3227 for (Type sup = syms.annotationType; sup.hasTag(CLASS); sup = types.supertype(sup)) {
3228 Scope s = sup.tsym.members();
3229 for (Symbol sym : s.getSymbolsByName(m.name)) {
3230 if (sym.kind == MTH &&
3231 (sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
3232 types.overrideEquivalent(m.type, sym.type))
3233 log.error(pos, Errors.IntfAnnotationMemberClash(sym, sup));
3234 }
3235 }
3236 }
3237
3238 /** Check the annotations of a symbol.
3239 */
3240 public void validateAnnotations(List<JCAnnotation> annotations, JCTree declarationTree, Symbol s) {
3241 for (JCAnnotation a : annotations)
3242 validateAnnotation(a, declarationTree, s);
3243 }
3244
3245 /** Check the type annotations.
3246 */
3247 public void validateTypeAnnotations(List<JCAnnotation> annotations, Symbol s, boolean isTypeParameter) {
3248 for (JCAnnotation a : annotations)
3249 validateTypeAnnotation(a, s, isTypeParameter);
3250 }
3251
3252 /** Check an annotation of a symbol.
3253 */
3254 private void validateAnnotation(JCAnnotation a, JCTree declarationTree, Symbol s) {
3255 /** NOTE: if annotation processors are present, annotation processing rounds can happen after this method,
3256 * this can impact in particular records for which annotations are forcibly propagated.
3257 */
3258 validateAnnotationTree(a);
3259 boolean isRecordMember = ((s.flags_field & RECORD) != 0 || s.enclClass() != null && s.enclClass().isRecord());
3260
3261 boolean isRecordField = (s.flags_field & RECORD) != 0 &&
3262 declarationTree.hasTag(VARDEF) &&
3263 s.owner.kind == TYP;
3264
3265 if (isRecordField) {
3266 // first we need to check if the annotation is applicable to records
3267 Name[] targets = getTargetNames(a);
3268 boolean appliesToRecords = false;
3269 for (Name target : targets) {
3270 appliesToRecords =
3271 target == names.FIELD ||
3272 target == names.PARAMETER ||
3273 target == names.METHOD ||
3274 target == names.TYPE_USE ||
3275 target == names.RECORD_COMPONENT;
3276 if (appliesToRecords) {
3277 break;
3278 }
3279 }
3280 if (!appliesToRecords) {
3281 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3282 } else {
3283 /* lets now find the annotations in the field that are targeted to record components and append them to
3284 * the corresponding record component
3285 */
3286 ClassSymbol recordClass = (ClassSymbol) s.owner;
3287 RecordComponent rc = recordClass.getRecordComponent((VarSymbol)s);
3288 SymbolMetadata metadata = rc.getMetadata();
3289 if (metadata == null || metadata.isEmpty()) {
3290 /* if not is empty then we have already been here, which is the case if multiple annotations are applied
3291 * to the record component declaration
3292 */
3293 rc.appendAttributes(s.getRawAttributes().stream().filter(anno ->
3294 Arrays.stream(getTargetNames(anno.type.tsym)).anyMatch(name -> name == names.RECORD_COMPONENT)
3295 ).collect(List.collector()));
3296
3297 JCVariableDecl fieldAST = (JCVariableDecl) declarationTree;
3298 for (JCAnnotation fieldAnnot : fieldAST.mods.annotations) {
3299 for (JCAnnotation rcAnnot : rc.declarationFor().mods.annotations) {
3300 if (rcAnnot.pos == fieldAnnot.pos) {
3301 rcAnnot.setType(fieldAnnot.type);
3302 break;
3303 }
3304 }
3305 }
3306
3307 /* At this point, we used to carry over any type annotations from the VARDEF to the record component, but
3308 * that is problematic, since we get here only when *some* annotation is applied to the SE5 (declaration)
3309 * annotation location, inadvertently failing to carry over the type annotations when the VarDef has no
3310 * annotations in the SE5 annotation location.
3311 *
3312 * Now type annotations are assigned to record components in a method that would execute irrespective of
3313 * whether there are SE5 annotations on a VarDef viz com.sun.tools.javac.code.TypeAnnotations.TypeAnnotationPositions.visitVarDef
3314 */
3315 }
3316 }
3317 }
3318
3319 /* the section below is tricky. Annotations applied to record components are propagated to the corresponding
3320 * record member so if an annotation has target: FIELD, it is propagated to the corresponding FIELD, if it has
3321 * target METHOD, it is propagated to the accessor and so on. But at the moment when method members are generated
3322 * there is no enough information to propagate only the right annotations. So all the annotations are propagated
3323 * to all the possible locations.
3324 *
3325 * At this point we need to remove all the annotations that are not in place before going on with the annotation
3326 * party. On top of the above there is the issue that there is no AST representing record components, just symbols
3327 * so the corresponding field has been holding all the annotations and it's metadata has been modified as if it
3328 * was both a field and a record component.
3329 *
3330 * So there are two places where we need to trim annotations from: the metadata of the symbol and / or the modifiers
3331 * in the AST. Whatever is in the metadata will be written to the class file, whatever is in the modifiers could
3332 * be see by annotation processors.
3333 *
3334 * The metadata contains both type annotations and declaration annotations. At this point of the game we don't
3335 * need to care about type annotations, they are all in the right place. But we could need to remove declaration
3336 * annotations. So for declaration annotations if they are not applicable to the record member, excluding type
3337 * annotations which are already correct, then we will remove it. For the AST modifiers if the annotation is not
3338 * applicable either as type annotation and or declaration annotation, only in that case it will be removed.
3339 *
3340 * So it could be that annotation is removed as a declaration annotation but it is kept in the AST modifier for
3341 * further inspection by annotation processors.
3342 *
3343 * For example:
3344 *
3345 * import java.lang.annotation.*;
3346 *
3347 * @Target({ElementType.TYPE_USE, ElementType.RECORD_COMPONENT})
3348 * @Retention(RetentionPolicy.RUNTIME)
3349 * @interface Anno { }
3350 *
3351 * record R(@Anno String s) {}
3352 *
3353 * at this point we will have for the case of the generated field:
3354 * - @Anno in the modifier
3355 * - @Anno as a type annotation
3356 * - @Anno as a declaration annotation
3357 *
3358 * the last one should be removed because the annotation has not FIELD as target but it was applied as a
3359 * declaration annotation because the field was being treated both as a field and as a record component
3360 * as we have already copied the annotations to the record component, now the field doesn't need to hold
3361 * annotations that are not intended for it anymore. Still @Anno has to be kept in the AST's modifiers as it
3362 * is applicable as a type annotation to the type of the field.
3363 */
3364
3365 if (a.type.tsym.isAnnotationType()) {
3366 Optional<Set<Name>> applicableTargetsOp = getApplicableTargets(a, s);
3367 if (!applicableTargetsOp.isEmpty()) {
3368 Set<Name> applicableTargets = applicableTargetsOp.get();
3369 boolean notApplicableOrIsTypeUseOnly = applicableTargets.isEmpty() ||
3370 applicableTargets.size() == 1 && applicableTargets.contains(names.TYPE_USE);
3371 boolean isCompGeneratedRecordElement = isRecordMember && (s.flags_field & Flags.GENERATED_MEMBER) != 0;
3372 boolean isCompRecordElementWithNonApplicableDeclAnno = isCompGeneratedRecordElement && notApplicableOrIsTypeUseOnly;
3373
3374 if (applicableTargets.isEmpty() || isCompRecordElementWithNonApplicableDeclAnno) {
3375 if (isCompRecordElementWithNonApplicableDeclAnno) {
3376 /* so we have found an annotation that is not applicable to a record member that was generated by the
3377 * compiler. This was intentionally done at TypeEnter, now is the moment strip away the annotations
3378 * that are not applicable to the given record member
3379 */
3380 JCModifiers modifiers = TreeInfo.getModifiers(declarationTree);
3381 /* lets first remove the annotation from the modifier if it is not applicable, we have to check again as
3382 * it could be a type annotation
3383 */
3384 if (modifiers != null && applicableTargets.isEmpty()) {
3385 ListBuffer<JCAnnotation> newAnnotations = new ListBuffer<>();
3386 for (JCAnnotation anno : modifiers.annotations) {
3387 if (anno != a) {
3388 newAnnotations.add(anno);
3389 }
3390 }
3391 modifiers.annotations = newAnnotations.toList();
3392 }
3393 // now lets remove it from the symbol
3394 s.getMetadata().removeDeclarationMetadata(a.attribute);
3395 } else {
3396 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3397 }
3398 }
3399 /* if we are seeing the @SafeVarargs annotation applied to a compiler generated accessor,
3400 * then this is an error as we know that no compiler generated accessor will be a varargs
3401 * method, better to fail asap
3402 */
3403 if (isCompGeneratedRecordElement && !isRecordField && a.type.tsym == syms.trustMeType.tsym && declarationTree.hasTag(METHODDEF)) {
3404 log.error(a.pos(), Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym, Fragments.VarargsTrustmeOnNonVarargsAccessor(s)));
3405 }
3406 }
3407 }
3408
3409 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
3410 if (s.kind != TYP) {
3411 log.error(a.pos(), Errors.BadFunctionalIntfAnno);
3412 } else if (!s.isInterface() || (s.flags() & ANNOTATION) != 0) {
3413 log.error(a.pos(), Errors.BadFunctionalIntfAnno1(Fragments.NotAFunctionalIntf(s)));
3414 }
3415 }
3416 }
3417
3418 public void validateTypeAnnotation(JCAnnotation a, Symbol s, boolean isTypeParameter) {
3419 Assert.checkNonNull(a.type);
3420 // we just want to validate that the anotation doesn't have any wrong target
3421 if (s != null) getApplicableTargets(a, s);
3422 validateAnnotationTree(a);
3423
3424 if (a.hasTag(TYPE_ANNOTATION) &&
3425 !a.annotationType.type.isErroneous() &&
3426 !isTypeAnnotation(a, isTypeParameter)) {
3427 log.error(a.pos(), Errors.AnnotationTypeNotApplicableToType(a.type));
3428 }
3429 }
3430
3431 /**
3432 * Validate the proposed container 'repeatable' on the
3433 * annotation type symbol 's'. Report errors at position
3434 * 'pos'.
3435 *
3436 * @param s The (annotation)type declaration annotated with a @Repeatable
3437 * @param repeatable the @Repeatable on 's'
3438 * @param pos where to report errors
3439 */
3440 public void validateRepeatable(TypeSymbol s, Attribute.Compound repeatable, DiagnosticPosition pos) {
3441 Assert.check(types.isSameType(repeatable.type, syms.repeatableType));
3442
3443 Type t = null;
3444 List<Pair<MethodSymbol,Attribute>> l = repeatable.values;
3445 if (!l.isEmpty()) {
3446 Assert.check(l.head.fst.name == names.value);
3447 if (l.head.snd instanceof Attribute.Class) {
3448 t = ((Attribute.Class)l.head.snd).getValue();
3449 }
3450 }
3451
3452 if (t == null) {
3453 // errors should already have been reported during Annotate
3454 return;
3455 }
3456
3457 validateValue(t.tsym, s, pos);
3458 validateRetention(t.tsym, s, pos);
3459 validateDocumented(t.tsym, s, pos);
3460 validateInherited(t.tsym, s, pos);
3461 validateTarget(t.tsym, s, pos);
3462 validateDefault(t.tsym, pos);
3463 }
3464
3465 private void validateValue(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3466 Symbol sym = container.members().findFirst(names.value);
3467 if (sym != null && sym.kind == MTH) {
3468 MethodSymbol m = (MethodSymbol) sym;
3469 Type ret = m.getReturnType();
3470 if (!(ret.hasTag(ARRAY) && types.isSameType(((ArrayType)ret).elemtype, contained.type))) {
3471 log.error(pos,
3472 Errors.InvalidRepeatableAnnotationValueReturn(container,
3473 ret,
3474 types.makeArrayType(contained.type)));
3475 }
3476 } else {
3477 log.error(pos, Errors.InvalidRepeatableAnnotationNoValue(container));
3478 }
3479 }
3480
3481 private void validateRetention(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3482 Attribute.RetentionPolicy containerRetention = types.getRetention(container);
3483 Attribute.RetentionPolicy containedRetention = types.getRetention(contained);
3484
3485 boolean error = false;
3486 switch (containedRetention) {
3487 case RUNTIME:
3488 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) {
3489 error = true;
3490 }
3491 break;
3492 case CLASS:
3493 if (containerRetention == Attribute.RetentionPolicy.SOURCE) {
3494 error = true;
3495 }
3496 }
3497 if (error ) {
3498 log.error(pos,
3499 Errors.InvalidRepeatableAnnotationRetention(container,
3500 containerRetention.name(),
3501 contained,
3502 containedRetention.name()));
3503 }
3504 }
3505
3506 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) {
3507 if (contained.attribute(syms.documentedType.tsym) != null) {
3508 if (container.attribute(syms.documentedType.tsym) == null) {
3509 log.error(pos, Errors.InvalidRepeatableAnnotationNotDocumented(container, contained));
3510 }
3511 }
3512 }
3513
3514 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) {
3515 if (contained.attribute(syms.inheritedType.tsym) != null) {
3516 if (container.attribute(syms.inheritedType.tsym) == null) {
3517 log.error(pos, Errors.InvalidRepeatableAnnotationNotInherited(container, contained));
3518 }
3519 }
3520 }
3521
3522 private void validateTarget(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3523 // The set of targets the container is applicable to must be a subset
3524 // (with respect to annotation target semantics) of the set of targets
3525 // the contained is applicable to. The target sets may be implicit or
3526 // explicit.
3527
3528 Set<Name> containerTargets;
3529 Attribute.Array containerTarget = getAttributeTargetAttribute(container);
3530 if (containerTarget == null) {
3531 containerTargets = getDefaultTargetSet();
3532 } else {
3533 containerTargets = new HashSet<>();
3534 for (Attribute app : containerTarget.values) {
3535 if (!(app instanceof Attribute.Enum attributeEnum)) {
3536 continue; // recovery
3537 }
3538 containerTargets.add(attributeEnum.value.name);
3539 }
3540 }
3541
3542 Set<Name> containedTargets;
3543 Attribute.Array containedTarget = getAttributeTargetAttribute(contained);
3544 if (containedTarget == null) {
3545 containedTargets = getDefaultTargetSet();
3546 } else {
3547 containedTargets = new HashSet<>();
3548 for (Attribute app : containedTarget.values) {
3549 if (!(app instanceof Attribute.Enum attributeEnum)) {
3550 continue; // recovery
3551 }
3552 containedTargets.add(attributeEnum.value.name);
3553 }
3554 }
3555
3556 if (!isTargetSubsetOf(containerTargets, containedTargets)) {
3557 log.error(pos, Errors.InvalidRepeatableAnnotationIncompatibleTarget(container, contained));
3558 }
3559 }
3560
3561 /* get a set of names for the default target */
3562 private Set<Name> getDefaultTargetSet() {
3563 if (defaultTargets == null) {
3564 defaultTargets = Set.of(defaultTargetMetaInfo());
3565 }
3566
3567 return defaultTargets;
3568 }
3569 private Set<Name> defaultTargets;
3570
3571
3572 /** Checks that s is a subset of t, with respect to ElementType
3573 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE},
3574 * and {TYPE_USE} covers the set {ANNOTATION_TYPE, TYPE, TYPE_USE,
3575 * TYPE_PARAMETER}.
3576 */
3577 private boolean isTargetSubsetOf(Set<Name> s, Set<Name> t) {
3578 // Check that all elements in s are present in t
3579 for (Name n2 : s) {
3580 boolean currentElementOk = false;
3581 for (Name n1 : t) {
3582 if (n1 == n2) {
3583 currentElementOk = true;
3584 break;
3585 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) {
3586 currentElementOk = true;
3587 break;
3588 } else if (n1 == names.TYPE_USE &&
3589 (n2 == names.TYPE ||
3590 n2 == names.ANNOTATION_TYPE ||
3591 n2 == names.TYPE_PARAMETER)) {
3592 currentElementOk = true;
3593 break;
3594 }
3595 }
3596 if (!currentElementOk)
3597 return false;
3598 }
3599 return true;
3600 }
3601
3602 private void validateDefault(Symbol container, DiagnosticPosition pos) {
3603 // validate that all other elements of containing type has defaults
3604 Scope scope = container.members();
3605 for(Symbol elm : scope.getSymbols()) {
3606 if (elm.name != names.value &&
3607 elm.kind == MTH &&
3608 ((MethodSymbol)elm).defaultValue == null) {
3609 log.error(pos,
3610 Errors.InvalidRepeatableAnnotationElemNondefault(container, elm));
3611 }
3612 }
3613 }
3614
3615 /** Is s a method symbol that overrides a method in a superclass? */
3616 boolean isOverrider(Symbol s) {
3617 if (s.kind != MTH || s.isStatic())
3618 return false;
3619 MethodSymbol m = (MethodSymbol)s;
3620 TypeSymbol owner = (TypeSymbol)m.owner;
3621 for (Type sup : types.closure(owner.type)) {
3622 if (sup == owner.type)
3623 continue; // skip "this"
3624 Scope scope = sup.tsym.members();
3625 for (Symbol sym : scope.getSymbolsByName(m.name)) {
3626 if (!sym.isStatic() && m.overrides(sym, owner, types, true))
3627 return true;
3628 }
3629 }
3630 return false;
3631 }
3632
3633 /** Is the annotation applicable to types? */
3634 protected boolean isTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
3635 List<Attribute> targets = typeAnnotations.annotationTargets(a.annotationType.type.tsym);
3636 return (targets == null) ?
3637 (Feature.NO_TARGET_ANNOTATION_APPLICABILITY.allowedInSource(source) && isTypeParameter) :
3638 targets.stream()
3639 .anyMatch(attr -> isTypeAnnotation(attr, isTypeParameter));
3640 }
3641 //where
3642 boolean isTypeAnnotation(Attribute a, boolean isTypeParameter) {
3643 Attribute.Enum e = (Attribute.Enum)a;
3644 return (e.value.name == names.TYPE_USE ||
3645 (isTypeParameter && e.value.name == names.TYPE_PARAMETER));
3646 }
3647
3648 /** Is the annotation applicable to the symbol? */
3649 Name[] getTargetNames(JCAnnotation a) {
3650 return getTargetNames(a.annotationType.type.tsym);
3651 }
3652
3653 public Name[] getTargetNames(TypeSymbol annoSym) {
3654 Attribute.Array arr = getAttributeTargetAttribute(annoSym);
3655 Name[] targets;
3656 if (arr == null) {
3657 targets = defaultTargetMetaInfo();
3658 } else {
3659 // TODO: can we optimize this?
3660 targets = new Name[arr.values.length];
3661 for (int i=0; i<arr.values.length; ++i) {
3662 Attribute app = arr.values[i];
3663 if (!(app instanceof Attribute.Enum attributeEnum)) {
3664 return new Name[0];
3665 }
3666 targets[i] = attributeEnum.value.name;
3667 }
3668 }
3669 return targets;
3670 }
3671
3672 boolean annotationApplicable(JCAnnotation a, Symbol s) {
3673 Optional<Set<Name>> targets = getApplicableTargets(a, s);
3674 /* the optional could be empty if the annotation is unknown in that case
3675 * we return that it is applicable and if it is erroneous that should imply
3676 * an error at the declaration site
3677 */
3678 return targets.isEmpty() || targets.isPresent() && !targets.get().isEmpty();
3679 }
3680
3681 Optional<Set<Name>> getApplicableTargets(JCAnnotation a, Symbol s) {
3682 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym);
3683 Name[] targets;
3684 Set<Name> applicableTargets = new HashSet<>();
3685
3686 if (arr == null) {
3687 targets = defaultTargetMetaInfo();
3688 } else {
3689 // TODO: can we optimize this?
3690 targets = new Name[arr.values.length];
3691 for (int i=0; i<arr.values.length; ++i) {
3692 Attribute app = arr.values[i];
3693 if (!(app instanceof Attribute.Enum attributeEnum)) {
3694 // recovery
3695 return Optional.empty();
3696 }
3697 targets[i] = attributeEnum.value.name;
3698 }
3699 }
3700 for (Name target : targets) {
3701 if (target == names.TYPE) {
3702 if (s.kind == TYP)
3703 applicableTargets.add(names.TYPE);
3704 } else if (target == names.FIELD) {
3705 if (s.kind == VAR && s.owner.kind != MTH)
3706 applicableTargets.add(names.FIELD);
3707 } else if (target == names.RECORD_COMPONENT) {
3708 if (s.getKind() == ElementKind.RECORD_COMPONENT) {
3709 applicableTargets.add(names.RECORD_COMPONENT);
3710 }
3711 } else if (target == names.METHOD) {
3712 if (s.kind == MTH && !s.isConstructor())
3713 applicableTargets.add(names.METHOD);
3714 } else if (target == names.PARAMETER) {
3715 if (s.kind == VAR &&
3716 (s.owner.kind == MTH && (s.flags() & PARAMETER) != 0)) {
3717 applicableTargets.add(names.PARAMETER);
3718 }
3719 } else if (target == names.CONSTRUCTOR) {
3720 if (s.kind == MTH && s.isConstructor())
3721 applicableTargets.add(names.CONSTRUCTOR);
3722 } else if (target == names.LOCAL_VARIABLE) {
3723 if (s.kind == VAR && s.owner.kind == MTH &&
3724 (s.flags() & PARAMETER) == 0) {
3725 applicableTargets.add(names.LOCAL_VARIABLE);
3726 }
3727 } else if (target == names.ANNOTATION_TYPE) {
3728 if (s.kind == TYP && (s.flags() & ANNOTATION) != 0) {
3729 applicableTargets.add(names.ANNOTATION_TYPE);
3730 }
3731 } else if (target == names.PACKAGE) {
3732 if (s.kind == PCK)
3733 applicableTargets.add(names.PACKAGE);
3734 } else if (target == names.TYPE_USE) {
3735 if (s.kind == VAR && s.owner.kind == MTH && s.type.hasTag(NONE)) {
3736 //cannot type annotate implicitly typed locals
3737 continue;
3738 } else if (s.kind == TYP || s.kind == VAR ||
3739 (s.kind == MTH && !s.isConstructor() &&
3740 !s.type.getReturnType().hasTag(VOID)) ||
3741 (s.kind == MTH && s.isConstructor())) {
3742 applicableTargets.add(names.TYPE_USE);
3743 }
3744 } else if (target == names.TYPE_PARAMETER) {
3745 if (s.kind == TYP && s.type.hasTag(TYPEVAR))
3746 applicableTargets.add(names.TYPE_PARAMETER);
3747 } else if (target == names.MODULE) {
3748 if (s.kind == MDL)
3749 applicableTargets.add(names.MODULE);
3750 } else {
3751 log.error(a, Errors.AnnotationUnrecognizedAttributeName(a.type, target));
3752 return Optional.empty(); // Unknown ElementType
3753 }
3754 }
3755 return Optional.of(applicableTargets);
3756 }
3757
3758 Attribute.Array getAttributeTargetAttribute(TypeSymbol s) {
3759 Attribute.Compound atTarget = s.getAnnotationTypeMetadata().getTarget();
3760 if (atTarget == null) return null; // ok, is applicable
3761 Attribute atValue = atTarget.member(names.value);
3762 return (atValue instanceof Attribute.Array attributeArray) ? attributeArray : null;
3763 }
3764
3765 private Name[] dfltTargetMeta;
3766 private Name[] defaultTargetMetaInfo() {
3767 if (dfltTargetMeta == null) {
3768 ArrayList<Name> defaultTargets = new ArrayList<>();
3769 defaultTargets.add(names.PACKAGE);
3770 defaultTargets.add(names.TYPE);
3771 defaultTargets.add(names.FIELD);
3772 defaultTargets.add(names.METHOD);
3773 defaultTargets.add(names.CONSTRUCTOR);
3774 defaultTargets.add(names.ANNOTATION_TYPE);
3775 defaultTargets.add(names.LOCAL_VARIABLE);
3776 defaultTargets.add(names.PARAMETER);
3777 if (allowRecords) {
3778 defaultTargets.add(names.RECORD_COMPONENT);
3779 }
3780 if (allowModules) {
3781 defaultTargets.add(names.MODULE);
3782 }
3783 dfltTargetMeta = defaultTargets.toArray(new Name[0]);
3784 }
3785 return dfltTargetMeta;
3786 }
3787
3788 /** Check an annotation value.
3789 *
3790 * @param a The annotation tree to check
3791 * @return true if this annotation tree is valid, otherwise false
3792 */
3793 public boolean validateAnnotationDeferErrors(JCAnnotation a) {
3794 boolean res = false;
3795 final Log.DiagnosticHandler diagHandler = log.new DiscardDiagnosticHandler();
3796 try {
3797 res = validateAnnotation(a);
3798 } finally {
3799 log.popDiagnosticHandler(diagHandler);
3800 }
3801 return res;
3802 }
3803
3804 private boolean validateAnnotation(JCAnnotation a) {
3805 boolean isValid = true;
3806 AnnotationTypeMetadata metadata = a.annotationType.type.tsym.getAnnotationTypeMetadata();
3807
3808 // collect an inventory of the annotation elements
3809 Set<MethodSymbol> elements = metadata.getAnnotationElements();
3810
3811 // remove the ones that are assigned values
3812 for (JCTree arg : a.args) {
3813 if (!arg.hasTag(ASSIGN)) continue; // recovery
3814 JCAssign assign = (JCAssign)arg;
3815 Symbol m = TreeInfo.symbol(assign.lhs);
3816 if (m == null || m.type.isErroneous()) continue;
3817 if (!elements.remove(m)) {
3818 isValid = false;
3819 log.error(assign.lhs.pos(),
3820 Errors.DuplicateAnnotationMemberValue(m.name, a.type));
3821 }
3822 }
3823
3824 // all the remaining ones better have default values
3825 List<Name> missingDefaults = List.nil();
3826 Set<MethodSymbol> membersWithDefault = metadata.getAnnotationElementsWithDefault();
3827 for (MethodSymbol m : elements) {
3828 if (m.type.isErroneous())
3829 continue;
3830
3831 if (!membersWithDefault.contains(m))
3832 missingDefaults = missingDefaults.append(m.name);
3833 }
3834 missingDefaults = missingDefaults.reverse();
3835 if (missingDefaults.nonEmpty()) {
3836 isValid = false;
3837 Error errorKey = (missingDefaults.size() > 1)
3838 ? Errors.AnnotationMissingDefaultValue1(a.type, missingDefaults)
3839 : Errors.AnnotationMissingDefaultValue(a.type, missingDefaults);
3840 log.error(a.pos(), errorKey);
3841 }
3842
3843 return isValid && validateTargetAnnotationValue(a);
3844 }
3845
3846 /* Validate the special java.lang.annotation.Target annotation */
3847 boolean validateTargetAnnotationValue(JCAnnotation a) {
3848 // special case: java.lang.annotation.Target must not have
3849 // repeated values in its value member
3850 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
3851 a.args.tail == null)
3852 return true;
3853
3854 boolean isValid = true;
3855 if (!a.args.head.hasTag(ASSIGN)) return false; // error recovery
3856 JCAssign assign = (JCAssign) a.args.head;
3857 Symbol m = TreeInfo.symbol(assign.lhs);
3858 if (m.name != names.value) return false;
3859 JCTree rhs = assign.rhs;
3860 if (!rhs.hasTag(NEWARRAY)) return false;
3861 JCNewArray na = (JCNewArray) rhs;
3862 Set<Symbol> targets = new HashSet<>();
3863 for (JCTree elem : na.elems) {
3864 if (!targets.add(TreeInfo.symbol(elem))) {
3865 isValid = false;
3866 log.error(elem.pos(), Errors.RepeatedAnnotationTarget);
3867 }
3868 }
3869 return isValid;
3870 }
3871
3872 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
3873 if (lint.isEnabled(LintCategory.DEP_ANN) && s.isDeprecatableViaAnnotation() &&
3874 (s.flags() & DEPRECATED) != 0 &&
3875 !syms.deprecatedType.isErroneous() &&
3876 s.attribute(syms.deprecatedType.tsym) == null) {
3877 log.warning(pos, LintWarnings.MissingDeprecatedAnnotation);
3878 }
3879 // Note: @Deprecated has no effect on local variables, parameters and package decls.
3880 if (lint.isEnabled(LintCategory.DEPRECATION) && !s.isDeprecatableViaAnnotation()) {
3881 if (!syms.deprecatedType.isErroneous() && s.attribute(syms.deprecatedType.tsym) != null) {
3882 log.warning(pos,
3883 LintWarnings.DeprecatedAnnotationHasNoEffect(Kinds.kindName(s)));
3884 }
3885 }
3886 }
3887
3888 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
3889 checkDeprecated(() -> pos, other, s);
3890 }
3891
3892 void checkDeprecated(Supplier<DiagnosticPosition> pos, final Symbol other, final Symbol s) {
3893 if (!importSuppression
3894 && (s.isDeprecatedForRemoval() || s.isDeprecated() && !other.isDeprecated())
3895 && (s.outermostClass() != other.outermostClass() || s.outermostClass() == null)
3896 && s.kind != Kind.PCK) {
3897 deferredLintHandler.report(_l -> warnDeprecated(pos.get(), s));
3898 }
3899 }
3900
3901 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
3902 if ((s.flags() & PROPRIETARY) != 0) {
3903 deferredLintHandler.report(_l -> {
3904 log.mandatoryWarning(pos, Warnings.SunProprietary(s));
3905 });
3906 }
3907 }
3908
3909 void checkProfile(final DiagnosticPosition pos, final Symbol s) {
3910 if (profile != Profile.DEFAULT && (s.flags() & NOT_IN_PROFILE) != 0) {
3911 log.error(pos, Errors.NotInProfile(s, profile));
3912 }
3913 }
3914
3915 void checkPreview(DiagnosticPosition pos, Symbol other, Symbol s) {
3916 checkPreview(pos, other, Type.noType, s);
3917 }
3918
3919 void checkPreview(DiagnosticPosition pos, Symbol other, Type site, Symbol s) {
3920 boolean sIsPreview;
3921 Symbol previewSymbol;
3922 if ((s.flags() & PREVIEW_API) != 0) {
3923 sIsPreview = true;
3924 previewSymbol= s;
3925 } else if ((s.kind == Kind.MTH || s.kind == Kind.VAR) &&
3926 site.tsym != null &&
3927 (site.tsym.flags() & PREVIEW_API) == 0 &&
3928 (s.owner.flags() & PREVIEW_API) != 0) {
3929 //calling a method, or using a field, whose owner is a preview, but
3930 //using a site that is not a preview. Also produce an error or warning:
3931 sIsPreview = true;
3932 previewSymbol = s.owner;
3933 } else {
3934 sIsPreview = false;
3935 previewSymbol = null;
3936 }
3937 if (sIsPreview && !preview.participatesInPreview(syms, other, s) && !disablePreviewCheck) {
3938 if ((previewSymbol.flags() & PREVIEW_REFLECTIVE) == 0) {
3939 if (!preview.isEnabled()) {
3940 log.error(pos, Errors.IsPreview(s));
3941 } else {
3942 preview.markUsesPreview(pos);
3943 warnPreviewAPI(pos, LintWarnings.IsPreview(s));
3944 }
3945 } else {
3946 warnPreviewAPI(pos, LintWarnings.IsPreviewReflective(s));
3947 }
3948 }
3949 if (preview.declaredUsingPreviewFeature(s)) {
3950 if (preview.isEnabled()) {
3951 //for preview disabled do presumably so not need to do anything?
3952 //If "s" is compiled from source, then there was an error for it already;
3953 //if "s" is from classfile, there already was an error for the classfile.
3954 preview.markUsesPreview(pos);
3955 warnPreviewAPI(pos, LintWarnings.DeclaredUsingPreview(kindName(s), s));
3956 }
3957 }
3958 }
3959
3960 void checkRestricted(DiagnosticPosition pos, Symbol s) {
3961 if (s.kind == MTH && (s.flags() & RESTRICTED) != 0) {
3962 deferredLintHandler.report(_l -> warnRestrictedAPI(pos, s));
3963 }
3964 }
3965
3966 /* *************************************************************************
3967 * Check for recursive annotation elements.
3968 **************************************************************************/
3969
3970 /** Check for cycles in the graph of annotation elements.
3971 */
3972 void checkNonCyclicElements(JCClassDecl tree) {
3973 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
3974 Assert.check((tree.sym.flags_field & LOCKED) == 0);
3975 try {
3976 tree.sym.flags_field |= LOCKED;
3977 for (JCTree def : tree.defs) {
3978 if (!def.hasTag(METHODDEF)) continue;
3979 JCMethodDecl meth = (JCMethodDecl)def;
3980 checkAnnotationResType(meth.pos(), meth.restype.type);
3981 }
3982 } finally {
3983 tree.sym.flags_field &= ~LOCKED;
3984 tree.sym.flags_field |= ACYCLIC_ANN;
3985 }
3986 }
3987
3988 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
3989 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
3990 return;
3991 if ((tsym.flags_field & LOCKED) != 0) {
3992 log.error(pos, Errors.CyclicAnnotationElement(tsym));
3993 return;
3994 }
3995 try {
3996 tsym.flags_field |= LOCKED;
3997 for (Symbol s : tsym.members().getSymbols(NON_RECURSIVE)) {
3998 if (s.kind != MTH)
3999 continue;
4000 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
4001 }
4002 } finally {
4003 tsym.flags_field &= ~LOCKED;
4004 tsym.flags_field |= ACYCLIC_ANN;
4005 }
4006 }
4007
4008 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
4009 switch (type.getTag()) {
4010 case CLASS:
4011 if ((type.tsym.flags() & ANNOTATION) != 0)
4012 checkNonCyclicElementsInternal(pos, type.tsym);
4013 break;
4014 case ARRAY:
4015 checkAnnotationResType(pos, types.elemtype(type));
4016 break;
4017 default:
4018 break; // int etc
4019 }
4020 }
4021
4022 /* *************************************************************************
4023 * Check for cycles in the constructor call graph.
4024 **************************************************************************/
4025
4026 /** Check for cycles in the graph of constructors calling other
4027 * constructors.
4028 */
4029 void checkCyclicConstructors(JCClassDecl tree) {
4030 // use LinkedHashMap so we generate errors deterministically
4031 Map<Symbol,Symbol> callMap = new LinkedHashMap<>();
4032
4033 // enter each constructor this-call into the map
4034 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
4035 if (!TreeInfo.isConstructor(l.head))
4036 continue;
4037 JCMethodDecl meth = (JCMethodDecl)l.head;
4038 JCMethodInvocation app = TreeInfo.findConstructorCall(meth);
4039 if (app != null && TreeInfo.name(app.meth) == names._this) {
4040 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
4041 } else {
4042 meth.sym.flags_field |= ACYCLIC;
4043 }
4044 }
4045
4046 // Check for cycles in the map
4047 Symbol[] ctors = new Symbol[0];
4048 ctors = callMap.keySet().toArray(ctors);
4049 for (Symbol caller : ctors) {
4050 checkCyclicConstructor(tree, caller, callMap);
4051 }
4052 }
4053
4054 /** Look in the map to see if the given constructor is part of a
4055 * call cycle.
4056 */
4057 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
4058 Map<Symbol,Symbol> callMap) {
4059 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
4060 if ((ctor.flags_field & LOCKED) != 0) {
4061 log.error(TreeInfo.diagnosticPositionFor(ctor, tree, false, t -> t.hasTag(IDENT)),
4062 Errors.RecursiveCtorInvocation);
4063 } else {
4064 ctor.flags_field |= LOCKED;
4065 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
4066 ctor.flags_field &= ~LOCKED;
4067 }
4068 ctor.flags_field |= ACYCLIC;
4069 }
4070 }
4071
4072 /* *************************************************************************
4073 * Verify the proper placement of super()/this() calls.
4074 *
4075 * - super()/this() may only appear in constructors
4076 * - There must be at most one super()/this() call per constructor
4077 * - The super()/this() call, if any, must be a top-level statement in the
4078 * constructor, i.e., not nested inside any other statement or block
4079 * - There must be no return statements prior to the super()/this() call
4080 **************************************************************************/
4081
4082 void checkSuperInitCalls(JCClassDecl tree) {
4083 new SuperThisChecker().check(tree);
4084 }
4085
4086 private class SuperThisChecker extends TreeScanner {
4087
4088 // Match this scan stack: 1=JCMethodDecl, 2=JCExpressionStatement, 3=JCMethodInvocation
4089 private static final int MATCH_SCAN_DEPTH = 3;
4090
4091 private boolean constructor; // is this method a constructor?
4092 private boolean firstStatement; // at the first statement in method?
4093 private JCReturn earlyReturn; // first return prior to the super()/init(), if any
4094 private Name initCall; // whichever of "super" or "init" we've seen already
4095 private int scanDepth; // current scan recursion depth in method body
4096
4097 public void check(JCClassDecl classDef) {
4098 scan(classDef.defs);
4099 }
4100
4101 @Override
4102 public void visitMethodDef(JCMethodDecl tree) {
4103 Assert.check(!constructor);
4104 Assert.check(earlyReturn == null);
4105 Assert.check(initCall == null);
4106 Assert.check(scanDepth == 1);
4107
4108 // Initialize state for this method
4109 constructor = TreeInfo.isConstructor(tree);
4110 try {
4111
4112 // Scan method body
4113 if (tree.body != null) {
4114 firstStatement = true;
4115 for (List<JCStatement> l = tree.body.stats; l.nonEmpty(); l = l.tail) {
4116 scan(l.head);
4117 firstStatement = false;
4118 }
4119 }
4120
4121 // Verify no 'return' seen prior to an explicit super()/this() call
4122 if (constructor && earlyReturn != null && initCall != null)
4123 log.error(earlyReturn.pos(), Errors.ReturnBeforeSuperclassInitialized);
4124 } finally {
4125 firstStatement = false;
4126 constructor = false;
4127 earlyReturn = null;
4128 initCall = null;
4129 }
4130 }
4131
4132 @Override
4133 public void scan(JCTree tree) {
4134 scanDepth++;
4135 try {
4136 super.scan(tree);
4137 } finally {
4138 scanDepth--;
4139 }
4140 }
4141
4142 @Override
4143 public void visitApply(JCMethodInvocation apply) {
4144 do {
4145
4146 // Is this a super() or this() call?
4147 Name methodName = TreeInfo.name(apply.meth);
4148 if (methodName != names._super && methodName != names._this)
4149 break;
4150
4151 // super()/this() calls must only appear in a constructor
4152 if (!constructor) {
4153 log.error(apply.pos(), Errors.CallMustOnlyAppearInCtor);
4154 break;
4155 }
4156
4157 // super()/this() calls must be a top level statement
4158 if (scanDepth != MATCH_SCAN_DEPTH) {
4159 log.error(apply.pos(), Errors.CtorCallsNotAllowedHere);
4160 break;
4161 }
4162
4163 // super()/this() calls must not appear more than once
4164 if (initCall != null) {
4165 log.error(apply.pos(), Errors.RedundantSuperclassInit);
4166 break;
4167 }
4168
4169 // If super()/this() isn't first, require flexible constructors feature
4170 if (!firstStatement)
4171 preview.checkSourceLevel(apply.pos(), Feature.FLEXIBLE_CONSTRUCTORS);
4172
4173 // We found a legitimate super()/this() call; remember it
4174 initCall = methodName;
4175 } while (false);
4176
4177 // Proceed
4178 super.visitApply(apply);
4179 }
4180
4181 @Override
4182 public void visitReturn(JCReturn tree) {
4183 if (constructor && initCall == null && earlyReturn == null)
4184 earlyReturn = tree; // we have seen a return but not (yet) a super()/this()
4185 super.visitReturn(tree);
4186 }
4187
4188 @Override
4189 public void visitClassDef(JCClassDecl tree) {
4190 // don't descend any further
4191 }
4192
4193 @Override
4194 public void visitLambda(JCLambda tree) {
4195 final boolean constructorPrev = constructor;
4196 final boolean firstStatementPrev = firstStatement;
4197 final JCReturn earlyReturnPrev = earlyReturn;
4198 final Name initCallPrev = initCall;
4199 final int scanDepthPrev = scanDepth;
4200 constructor = false;
4201 firstStatement = false;
4202 earlyReturn = null;
4203 initCall = null;
4204 scanDepth = 0;
4205 try {
4206 super.visitLambda(tree);
4207 } finally {
4208 constructor = constructorPrev;
4209 firstStatement = firstStatementPrev;
4210 earlyReturn = earlyReturnPrev;
4211 initCall = initCallPrev;
4212 scanDepth = scanDepthPrev;
4213 }
4214 }
4215 }
4216
4217 /* *************************************************************************
4218 * Miscellaneous
4219 **************************************************************************/
4220
4221 /**
4222 * Check for division by integer constant zero
4223 * @param pos Position for error reporting.
4224 * @param operator The operator for the expression
4225 * @param operand The right hand operand for the expression
4226 */
4227 void checkDivZero(final DiagnosticPosition pos, Symbol operator, Type operand) {
4228 if (operand.constValue() != null
4229 && operand.getTag().isSubRangeOf(LONG)
4230 && ((Number) (operand.constValue())).longValue() == 0) {
4231 int opc = ((OperatorSymbol)operator).opcode;
4232 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
4233 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
4234 deferredLintHandler.report(_ -> lint.logIfEnabled(pos, LintWarnings.DivZero));
4235 }
4236 }
4237 }
4238
4239 /**
4240 * Check for possible loss of precission
4241 * @param pos Position for error reporting.
4242 * @param found The computed type of the tree
4243 * @param req The computed type of the tree
4244 */
4245 void checkLossOfPrecision(final DiagnosticPosition pos, Type found, Type req) {
4246 if (found.isNumeric() && req.isNumeric() && !types.isAssignable(found, req)) {
4247 deferredLintHandler.report(_ ->
4248 lint.logIfEnabled(pos, LintWarnings.PossibleLossOfPrecision(found, req)));
4249 }
4250 }
4251
4252 /**
4253 * Check for empty statements after if
4254 */
4255 void checkEmptyIf(JCIf tree) {
4256 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null) {
4257 lint.logIfEnabled(tree.thenpart.pos(), LintWarnings.EmptyIf);
4258 }
4259 }
4260
4261 /** Check that symbol is unique in given scope.
4262 * @param pos Position for error reporting.
4263 * @param sym The symbol.
4264 * @param s The scope.
4265 */
4266 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
4267 if (sym.type.isErroneous())
4268 return true;
4269 if (sym.owner.name == names.any) return false;
4270 for (Symbol byName : s.getSymbolsByName(sym.name, NON_RECURSIVE)) {
4271 if (sym != byName &&
4272 (byName.flags() & CLASH) == 0 &&
4273 sym.kind == byName.kind &&
4274 sym.name != names.error &&
4275 (sym.kind != MTH ||
4276 types.hasSameArgs(sym.type, byName.type) ||
4277 types.hasSameArgs(types.erasure(sym.type), types.erasure(byName.type)))) {
4278 if ((sym.flags() & VARARGS) != (byName.flags() & VARARGS)) {
4279 sym.flags_field |= CLASH;
4280 varargsDuplicateError(pos, sym, byName);
4281 return true;
4282 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, byName.type, false)) {
4283 duplicateErasureError(pos, sym, byName);
4284 sym.flags_field |= CLASH;
4285 return true;
4286 } else if ((sym.flags() & MATCH_BINDING) != 0 &&
4287 (byName.flags() & MATCH_BINDING) != 0 &&
4288 (byName.flags() & MATCH_BINDING_TO_OUTER) == 0) {
4289 if (!sym.type.isErroneous()) {
4290 log.error(pos, Errors.MatchBindingExists);
4291 sym.flags_field |= CLASH;
4292 }
4293 return false;
4294 } else {
4295 duplicateError(pos, byName);
4296 return false;
4297 }
4298 }
4299 }
4300 return true;
4301 }
4302
4303 /** Report duplicate declaration error.
4304 */
4305 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
4306 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
4307 log.error(pos, Errors.NameClashSameErasure(sym1, sym2));
4308 }
4309 }
4310
4311 /**Check that types imported through the ordinary imports don't clash with types imported
4312 * by other (static or ordinary) imports. Note that two static imports may import two clashing
4313 * types without an error on the imports.
4314 * @param toplevel The toplevel tree for which the test should be performed.
4315 */
4316 void checkImportsUnique(JCCompilationUnit toplevel) {
4317 WriteableScope ordinallyImportedSoFar = WriteableScope.create(toplevel.packge);
4318 WriteableScope staticallyImportedSoFar = WriteableScope.create(toplevel.packge);
4319 WriteableScope topLevelScope = toplevel.toplevelScope;
4320
4321 for (JCTree def : toplevel.defs) {
4322 if (!def.hasTag(IMPORT))
4323 continue;
4324
4325 JCImport imp = (JCImport) def;
4326
4327 if (imp.importScope == null)
4328 continue;
4329
4330 for (Symbol sym : imp.importScope.getSymbols(sym -> sym.kind == TYP)) {
4331 if (imp.isStatic()) {
4332 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, true);
4333 staticallyImportedSoFar.enter(sym);
4334 } else {
4335 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, false);
4336 ordinallyImportedSoFar.enter(sym);
4337 }
4338 }
4339
4340 imp.importScope = null;
4341 }
4342 }
4343
4344 /** Check that single-type import is not already imported or top-level defined,
4345 * but make an exception for two single-type imports which denote the same type.
4346 * @param pos Position for error reporting.
4347 * @param ordinallyImportedSoFar A Scope containing types imported so far through
4348 * ordinary imports.
4349 * @param staticallyImportedSoFar A Scope containing types imported so far through
4350 * static imports.
4351 * @param topLevelScope The current file's top-level Scope
4352 * @param sym The symbol.
4353 * @param staticImport Whether or not this was a static import
4354 */
4355 private boolean checkUniqueImport(DiagnosticPosition pos, Scope ordinallyImportedSoFar,
4356 Scope staticallyImportedSoFar, Scope topLevelScope,
4357 Symbol sym, boolean staticImport) {
4358 Predicate<Symbol> duplicates = candidate -> candidate != sym && !candidate.type.isErroneous();
4359 Symbol ordinaryClashing = ordinallyImportedSoFar.findFirst(sym.name, duplicates);
4360 Symbol staticClashing = null;
4361 if (ordinaryClashing == null && !staticImport) {
4362 staticClashing = staticallyImportedSoFar.findFirst(sym.name, duplicates);
4363 }
4364 if (ordinaryClashing != null || staticClashing != null) {
4365 if (ordinaryClashing != null)
4366 log.error(pos, Errors.AlreadyDefinedSingleImport(ordinaryClashing));
4367 else
4368 log.error(pos, Errors.AlreadyDefinedStaticSingleImport(staticClashing));
4369 return false;
4370 }
4371 Symbol clashing = topLevelScope.findFirst(sym.name, duplicates);
4372 if (clashing != null) {
4373 log.error(pos, Errors.AlreadyDefinedThisUnit(clashing));
4374 return false;
4375 }
4376 return true;
4377 }
4378
4379 /** Check that a qualified name is in canonical form (for import decls).
4380 */
4381 public void checkCanonical(JCTree tree) {
4382 if (!isCanonical(tree))
4383 log.error(tree.pos(),
4384 Errors.ImportRequiresCanonical(TreeInfo.symbol(tree)));
4385 }
4386 // where
4387 private boolean isCanonical(JCTree tree) {
4388 while (tree.hasTag(SELECT)) {
4389 JCFieldAccess s = (JCFieldAccess) tree;
4390 if (s.sym.owner.getQualifiedName() != TreeInfo.symbol(s.selected).getQualifiedName())
4391 return false;
4392 tree = s.selected;
4393 }
4394 return true;
4395 }
4396
4397 /** Check that an auxiliary class is not accessed from any other file than its own.
4398 */
4399 void checkForBadAuxiliaryClassAccess(DiagnosticPosition pos, Env<AttrContext> env, ClassSymbol c) {
4400 if ((c.flags() & AUXILIARY) != 0 &&
4401 rs.isAccessible(env, c) &&
4402 !fileManager.isSameFile(c.sourcefile, env.toplevel.sourcefile))
4403 {
4404 lint.logIfEnabled(pos,
4405 LintWarnings.AuxiliaryClassAccessedFromOutsideOfItsSourceFile(c, c.sourcefile));
4406 }
4407 }
4408
4409 /**
4410 * Check for a default constructor in an exported package.
4411 */
4412 void checkDefaultConstructor(ClassSymbol c, DiagnosticPosition pos) {
4413 if (lint.isEnabled(LintCategory.MISSING_EXPLICIT_CTOR) &&
4414 ((c.flags() & (ENUM | RECORD)) == 0) &&
4415 !c.isAnonymous() &&
4416 ((c.flags() & (PUBLIC | PROTECTED)) != 0) &&
4417 Feature.MODULES.allowedInSource(source)) {
4418 NestingKind nestingKind = c.getNestingKind();
4419 switch (nestingKind) {
4420 case ANONYMOUS,
4421 LOCAL -> {return;}
4422 case TOP_LEVEL -> {;} // No additional checks needed
4423 case MEMBER -> {
4424 // For nested member classes, all the enclosing
4425 // classes must be public or protected.
4426 Symbol owner = c.owner;
4427 while (owner != null && owner.kind == TYP) {
4428 if ((owner.flags() & (PUBLIC | PROTECTED)) == 0)
4429 return;
4430 owner = owner.owner;
4431 }
4432 }
4433 }
4434
4435 // Only check classes in named packages exported by its module
4436 PackageSymbol pkg = c.packge();
4437 if (!pkg.isUnnamed()) {
4438 ModuleSymbol modle = pkg.modle;
4439 for (ExportsDirective exportDir : modle.exports) {
4440 // Report warning only if the containing
4441 // package is unconditionally exported
4442 if (exportDir.packge.equals(pkg)) {
4443 if (exportDir.modules == null || exportDir.modules.isEmpty()) {
4444 // Warning may be suppressed by
4445 // annotations; check again for being
4446 // enabled in the deferred context.
4447 deferredLintHandler.report(_ ->
4448 lint.logIfEnabled(pos, LintWarnings.MissingExplicitCtor(c, pkg, modle)));
4449 } else {
4450 return;
4451 }
4452 }
4453 }
4454 }
4455 }
4456 return;
4457 }
4458
4459 private class ConversionWarner extends Warner {
4460 final String uncheckedKey;
4461 final Type found;
4462 final Type expected;
4463 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
4464 super(pos);
4465 this.uncheckedKey = uncheckedKey;
4466 this.found = found;
4467 this.expected = expected;
4468 }
4469
4470 @Override
4471 public void warn(LintCategory lint) {
4472 boolean warned = this.warned;
4473 super.warn(lint);
4474 if (warned) return; // suppress redundant diagnostics
4475 switch (lint) {
4476 case UNCHECKED:
4477 Check.this.warnUnchecked(pos(), LintWarnings.ProbFoundReq(diags.fragment(uncheckedKey), found, expected));
4478 break;
4479 case VARARGS:
4480 if (method != null &&
4481 method.attribute(syms.trustMeType.tsym) != null &&
4482 isTrustMeAllowedOnMethod(method) &&
4483 !types.isReifiable(method.type.getParameterTypes().last())) {
4484 Check.this.lint.logIfEnabled(pos(), LintWarnings.VarargsUnsafeUseVarargsParam(method.params.last()));
4485 }
4486 break;
4487 default:
4488 throw new AssertionError("Unexpected lint: " + lint);
4489 }
4490 }
4491 }
4492
4493 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
4494 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
4495 }
4496
4497 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
4498 return new ConversionWarner(pos, "unchecked.assign", found, expected);
4499 }
4500
4501 public void checkFunctionalInterface(JCClassDecl tree, ClassSymbol cs) {
4502 Compound functionalType = cs.attribute(syms.functionalInterfaceType.tsym);
4503
4504 if (functionalType != null) {
4505 try {
4506 types.findDescriptorSymbol((TypeSymbol)cs);
4507 } catch (Types.FunctionDescriptorLookupError ex) {
4508 DiagnosticPosition pos = tree.pos();
4509 for (JCAnnotation a : tree.getModifiers().annotations) {
4510 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
4511 pos = a.pos();
4512 break;
4513 }
4514 }
4515 log.error(pos, Errors.BadFunctionalIntfAnno1(ex.getDiagnostic()));
4516 }
4517 }
4518 }
4519
4520 public void checkImportsResolvable(final JCCompilationUnit toplevel) {
4521 for (final JCImportBase impBase : toplevel.getImports()) {
4522 if (!(impBase instanceof JCImport imp))
4523 continue;
4524 if (!imp.staticImport || !imp.qualid.hasTag(SELECT))
4525 continue;
4526 final JCFieldAccess select = imp.qualid;
4527 final Symbol origin;
4528 if (select.name == names.asterisk || (origin = TreeInfo.symbol(select.selected)) == null || origin.kind != TYP)
4529 continue;
4530
4531 TypeSymbol site = (TypeSymbol) TreeInfo.symbol(select.selected);
4532 if (!checkTypeContainsImportableElement(site, site, toplevel.packge, select.name, new HashSet<Symbol>())) {
4533 log.error(imp.pos(),
4534 Errors.CantResolveLocation(KindName.STATIC,
4535 select.name,
4536 null,
4537 null,
4538 Fragments.Location(kindName(site),
4539 site,
4540 null)));
4541 }
4542 }
4543 }
4544
4545 // Check that packages imported are in scope (JLS 7.4.3, 6.3, 6.5.3.1, 6.5.3.2)
4546 public void checkImportedPackagesObservable(final JCCompilationUnit toplevel) {
4547 OUTER: for (JCImportBase impBase : toplevel.getImports()) {
4548 if (impBase instanceof JCImport imp && !imp.staticImport &&
4549 TreeInfo.name(imp.qualid) == names.asterisk) {
4550 TypeSymbol tsym = imp.qualid.selected.type.tsym;
4551 if (tsym.kind == PCK && tsym.members().isEmpty() &&
4552 !(Feature.IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES.allowedInSource(source) && tsym.exists())) {
4553 log.error(DiagnosticFlag.RESOLVE_ERROR, imp.qualid.selected.pos(), Errors.DoesntExist(tsym));
4554 }
4555 }
4556 }
4557 }
4558
4559 private boolean checkTypeContainsImportableElement(TypeSymbol tsym, TypeSymbol origin, PackageSymbol packge, Name name, Set<Symbol> processed) {
4560 if (tsym == null || !processed.add(tsym))
4561 return false;
4562
4563 // also search through inherited names
4564 if (checkTypeContainsImportableElement(types.supertype(tsym.type).tsym, origin, packge, name, processed))
4565 return true;
4566
4567 for (Type t : types.interfaces(tsym.type))
4568 if (checkTypeContainsImportableElement(t.tsym, origin, packge, name, processed))
4569 return true;
4570
4571 for (Symbol sym : tsym.members().getSymbolsByName(name)) {
4572 if (sym.isStatic() &&
4573 importAccessible(sym, packge) &&
4574 sym.isMemberOf(origin, types)) {
4575 return true;
4576 }
4577 }
4578
4579 return false;
4580 }
4581
4582 // is the sym accessible everywhere in packge?
4583 public boolean importAccessible(Symbol sym, PackageSymbol packge) {
4584 try {
4585 int flags = (int)(sym.flags() & AccessFlags);
4586 switch (flags) {
4587 default:
4588 case PUBLIC:
4589 return true;
4590 case PRIVATE:
4591 return false;
4592 case 0:
4593 case PROTECTED:
4594 return sym.packge() == packge;
4595 }
4596 } catch (ClassFinder.BadClassFile err) {
4597 throw err;
4598 } catch (CompletionFailure ex) {
4599 return false;
4600 }
4601 }
4602
4603 public void checkLeaksNotAccessible(Env<AttrContext> env, JCClassDecl check) {
4604 JCCompilationUnit toplevel = env.toplevel;
4605
4606 if ( toplevel.modle == syms.unnamedModule
4607 || toplevel.modle == syms.noModule
4608 || (check.sym.flags() & COMPOUND) != 0) {
4609 return ;
4610 }
4611
4612 ExportsDirective currentExport = findExport(toplevel.packge);
4613
4614 if ( currentExport == null //not exported
4615 || currentExport.modules != null) //don't check classes in qualified export
4616 return ;
4617
4618 new TreeScanner() {
4619 Lint lint = env.info.lint;
4620 boolean inSuperType;
4621
4622 @Override
4623 public void visitBlock(JCBlock tree) {
4624 }
4625 @Override
4626 public void visitMethodDef(JCMethodDecl tree) {
4627 if (!isAPISymbol(tree.sym))
4628 return;
4629 Lint prevLint = lint;
4630 try {
4631 lint = lint.augment(tree.sym);
4632 if (lint.isEnabled(LintCategory.EXPORTS)) {
4633 super.visitMethodDef(tree);
4634 }
4635 } finally {
4636 lint = prevLint;
4637 }
4638 }
4639 @Override
4640 public void visitVarDef(JCVariableDecl tree) {
4641 if (!isAPISymbol(tree.sym) && tree.sym.owner.kind != MTH)
4642 return;
4643 Lint prevLint = lint;
4644 try {
4645 lint = lint.augment(tree.sym);
4646 if (lint.isEnabled(LintCategory.EXPORTS)) {
4647 scan(tree.mods);
4648 scan(tree.vartype);
4649 }
4650 } finally {
4651 lint = prevLint;
4652 }
4653 }
4654 @Override
4655 public void visitClassDef(JCClassDecl tree) {
4656 if (tree != check)
4657 return ;
4658
4659 if (!isAPISymbol(tree.sym))
4660 return ;
4661
4662 Lint prevLint = lint;
4663 try {
4664 lint = lint.augment(tree.sym);
4665 if (lint.isEnabled(LintCategory.EXPORTS)) {
4666 scan(tree.mods);
4667 scan(tree.typarams);
4668 try {
4669 inSuperType = true;
4670 scan(tree.extending);
4671 scan(tree.implementing);
4672 } finally {
4673 inSuperType = false;
4674 }
4675 scan(tree.defs);
4676 }
4677 } finally {
4678 lint = prevLint;
4679 }
4680 }
4681 @Override
4682 public void visitTypeApply(JCTypeApply tree) {
4683 scan(tree.clazz);
4684 boolean oldInSuperType = inSuperType;
4685 try {
4686 inSuperType = false;
4687 scan(tree.arguments);
4688 } finally {
4689 inSuperType = oldInSuperType;
4690 }
4691 }
4692 @Override
4693 public void visitIdent(JCIdent tree) {
4694 Symbol sym = TreeInfo.symbol(tree);
4695 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR)) {
4696 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4697 }
4698 }
4699
4700 @Override
4701 public void visitSelect(JCFieldAccess tree) {
4702 Symbol sym = TreeInfo.symbol(tree);
4703 Symbol sitesym = TreeInfo.symbol(tree.selected);
4704 if (sym.kind == TYP && sitesym.kind == PCK) {
4705 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4706 } else {
4707 super.visitSelect(tree);
4708 }
4709 }
4710
4711 @Override
4712 public void visitAnnotation(JCAnnotation tree) {
4713 if (tree.attribute.type.tsym.getAnnotation(java.lang.annotation.Documented.class) != null)
4714 super.visitAnnotation(tree);
4715 }
4716
4717 }.scan(check);
4718 }
4719 //where:
4720 private ExportsDirective findExport(PackageSymbol pack) {
4721 for (ExportsDirective d : pack.modle.exports) {
4722 if (d.packge == pack)
4723 return d;
4724 }
4725
4726 return null;
4727 }
4728 private boolean isAPISymbol(Symbol sym) {
4729 while (sym.kind != PCK) {
4730 if ((sym.flags() & Flags.PUBLIC) == 0 && (sym.flags() & Flags.PROTECTED) == 0) {
4731 return false;
4732 }
4733 sym = sym.owner;
4734 }
4735 return true;
4736 }
4737 private void checkVisible(DiagnosticPosition pos, Symbol what, PackageSymbol inPackage, boolean inSuperType) {
4738 if (!isAPISymbol(what) && !inSuperType) { //package private/private element
4739 log.warning(pos, LintWarnings.LeaksNotAccessible(kindName(what), what, what.packge().modle));
4740 return ;
4741 }
4742
4743 PackageSymbol whatPackage = what.packge();
4744 ExportsDirective whatExport = findExport(whatPackage);
4745 ExportsDirective inExport = findExport(inPackage);
4746
4747 if (whatExport == null) { //package not exported:
4748 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexported(kindName(what), what, what.packge().modle));
4749 return ;
4750 }
4751
4752 if (whatExport.modules != null) {
4753 if (inExport.modules == null || !whatExport.modules.containsAll(inExport.modules)) {
4754 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexportedQualified(kindName(what), what, what.packge().modle));
4755 }
4756 }
4757
4758 if (whatPackage.modle != inPackage.modle && whatPackage.modle != syms.java_base) {
4759 //check that relativeTo.modle requires transitive what.modle, somehow:
4760 List<ModuleSymbol> todo = List.of(inPackage.modle);
4761
4762 while (todo.nonEmpty()) {
4763 ModuleSymbol current = todo.head;
4764 todo = todo.tail;
4765 if (current == whatPackage.modle)
4766 return ; //OK
4767 if ((current.flags() & Flags.AUTOMATIC_MODULE) != 0)
4768 continue; //for automatic modules, don't look into their dependencies
4769 for (RequiresDirective req : current.requires) {
4770 if (req.isTransitive()) {
4771 todo = todo.prepend(req.module);
4772 }
4773 }
4774 }
4775
4776 log.warning(pos, LintWarnings.LeaksNotAccessibleNotRequiredTransitive(kindName(what), what, what.packge().modle));
4777 }
4778 }
4779
4780 void checkModuleExists(final DiagnosticPosition pos, ModuleSymbol msym) {
4781 if (msym.kind != MDL) {
4782 deferredLintHandler.report(_ ->
4783 lint.logIfEnabled(pos, LintWarnings.ModuleNotFound(msym)));
4784 }
4785 }
4786
4787 void checkPackageExistsForOpens(final DiagnosticPosition pos, PackageSymbol packge) {
4788 if (packge.members().isEmpty() &&
4789 ((packge.flags() & Flags.HAS_RESOURCE) == 0)) {
4790 deferredLintHandler.report(_ ->
4791 lint.logIfEnabled(pos, LintWarnings.PackageEmptyOrNotFound(packge)));
4792 }
4793 }
4794
4795 void checkModuleRequires(final DiagnosticPosition pos, final RequiresDirective rd) {
4796 if ((rd.module.flags() & Flags.AUTOMATIC_MODULE) != 0) {
4797 deferredLintHandler.report(_ -> {
4798 if (rd.isTransitive() && lint.isEnabled(LintCategory.REQUIRES_TRANSITIVE_AUTOMATIC)) {
4799 log.warning(pos, LintWarnings.RequiresTransitiveAutomatic);
4800 } else {
4801 lint.logIfEnabled(pos, LintWarnings.RequiresAutomatic);
4802 }
4803 });
4804 }
4805 }
4806
4807 /**
4808 * Verify the case labels conform to the constraints. Checks constraints related
4809 * combinations of patterns and other labels.
4810 *
4811 * @param cases the cases that should be checked.
4812 */
4813 void checkSwitchCaseStructure(List<JCCase> cases) {
4814 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4815 JCCase c = l.head;
4816 if (c.labels.head instanceof JCConstantCaseLabel constLabel) {
4817 if (TreeInfo.isNull(constLabel.expr)) {
4818 if (c.labels.tail.nonEmpty()) {
4819 if (c.labels.tail.head instanceof JCDefaultCaseLabel defLabel) {
4820 if (c.labels.tail.tail.nonEmpty()) {
4821 log.error(c.labels.tail.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4822 }
4823 } else {
4824 log.error(c.labels.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4825 }
4826 }
4827 } else {
4828 for (JCCaseLabel label : c.labels.tail) {
4829 if (!(label instanceof JCConstantCaseLabel) || TreeInfo.isNullCaseLabel(label)) {
4830 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4831 break;
4832 }
4833 }
4834 }
4835 } else if (c.labels.tail.nonEmpty()) {
4836 var patterCaseLabels = c.labels.stream().filter(ll -> ll instanceof JCPatternCaseLabel).map(cl -> (JCPatternCaseLabel)cl);
4837 var allUnderscore = patterCaseLabels.allMatch(pcl -> !hasBindings(pcl.getPattern()));
4838
4839 if (!allUnderscore) {
4840 log.error(c.labels.tail.head.pos(), Errors.FlowsThroughFromPattern);
4841 }
4842
4843 boolean allPatternCaseLabels = c.labels.stream().allMatch(p -> p instanceof JCPatternCaseLabel);
4844
4845 if (allPatternCaseLabels) {
4846 preview.checkSourceLevel(c.labels.tail.head.pos(), Feature.UNNAMED_VARIABLES);
4847 }
4848
4849 for (JCCaseLabel label : c.labels.tail) {
4850 if (label instanceof JCConstantCaseLabel) {
4851 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4852 break;
4853 }
4854 }
4855 }
4856 }
4857
4858 boolean isCaseStatementGroup = cases.nonEmpty() &&
4859 cases.head.caseKind == CaseTree.CaseKind.STATEMENT;
4860
4861 if (isCaseStatementGroup) {
4862 boolean previousCompletessNormally = false;
4863 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4864 JCCase c = l.head;
4865 if (previousCompletessNormally &&
4866 c.stats.nonEmpty() &&
4867 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4868 (hasBindings(patternLabel.pat) || hasBindings(c.guard))) {
4869 log.error(c.labels.head.pos(), Errors.FlowsThroughToPattern);
4870 } else if (c.stats.isEmpty() &&
4871 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4872 (hasBindings(patternLabel.pat) || hasBindings(c.guard)) &&
4873 hasStatements(l.tail)) {
4874 log.error(c.labels.head.pos(), Errors.FlowsThroughFromPattern);
4875 }
4876 previousCompletessNormally = c.completesNormally;
4877 }
4878 }
4879 }
4880
4881 boolean hasBindings(JCTree p) {
4882 boolean[] bindings = new boolean[1];
4883
4884 new TreeScanner() {
4885 @Override
4886 public void visitBindingPattern(JCBindingPattern tree) {
4887 bindings[0] |= !tree.var.sym.isUnnamedVariable();
4888 super.visitBindingPattern(tree);
4889 }
4890 }.scan(p);
4891
4892 return bindings[0];
4893 }
4894
4895 boolean hasStatements(List<JCCase> cases) {
4896 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4897 if (l.head.stats.nonEmpty()) {
4898 return true;
4899 }
4900 }
4901
4902 return false;
4903 }
4904 void checkSwitchCaseLabelDominated(JCCaseLabel unconditionalCaseLabel, List<JCCase> cases) {
4905 List<Pair<JCCase, JCCaseLabel>> caseLabels = List.nil();
4906 boolean seenDefault = false;
4907 boolean seenDefaultLabel = false;
4908 boolean warnDominatedByDefault = false;
4909 boolean unconditionalFound = false;
4910
4911 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4912 JCCase c = l.head;
4913 for (JCCaseLabel label : c.labels) {
4914 if (label.hasTag(DEFAULTCASELABEL)) {
4915 seenDefault = true;
4916 seenDefaultLabel |=
4917 TreeInfo.isNullCaseLabel(c.labels.head);
4918 continue;
4919 }
4920 if (TreeInfo.isNullCaseLabel(label)) {
4921 if (seenDefault) {
4922 log.error(label.pos(), Errors.PatternDominated);
4923 }
4924 continue;
4925 }
4926 if (seenDefault && !warnDominatedByDefault) {
4927 if (label.hasTag(PATTERNCASELABEL) ||
4928 (label instanceof JCConstantCaseLabel && seenDefaultLabel)) {
4929 log.error(label.pos(), Errors.PatternDominated);
4930 warnDominatedByDefault = true;
4931 }
4932 }
4933 Type currentType = labelType(label);
4934 for (Pair<JCCase, JCCaseLabel> caseAndLabel : caseLabels) {
4935 JCCase testCase = caseAndLabel.fst;
4936 JCCaseLabel testCaseLabel = caseAndLabel.snd;
4937 Type testType = labelType(testCaseLabel);
4938 boolean dominated = false;
4939 if (types.isUnconditionallyExact(currentType, testType) &&
4940 !currentType.hasTag(ERROR) && !testType.hasTag(ERROR)) {
4941 //the current label is potentially dominated by the existing (test) label, check:
4942 if (label instanceof JCConstantCaseLabel) {
4943 dominated |= !(testCaseLabel instanceof JCConstantCaseLabel) &&
4944 TreeInfo.unguardedCase(testCase);
4945 } else if (label instanceof JCPatternCaseLabel patternCL &&
4946 testCaseLabel instanceof JCPatternCaseLabel testPatternCaseLabel &&
4947 (testCase.equals(c) || TreeInfo.unguardedCase(testCase))) {
4948 dominated = patternDominated(testPatternCaseLabel.pat,
4949 patternCL.pat);
4950 }
4951 }
4952
4953 if (dominated) {
4954 log.error(label.pos(), Errors.PatternDominated);
4955 }
4956 }
4957 caseLabels = caseLabels.prepend(Pair.of(c, label));
4958 }
4959 }
4960 }
4961 //where:
4962 private Type labelType(JCCaseLabel label) {
4963 return types.erasure(switch (label.getTag()) {
4964 case PATTERNCASELABEL -> ((JCPatternCaseLabel) label).pat.type;
4965 case CONSTANTCASELABEL -> ((JCConstantCaseLabel) label).expr.type;
4966 default -> throw Assert.error("Unexpected tree kind: " + label.getTag());
4967 });
4968 }
4969 private boolean patternDominated(JCPattern existingPattern, JCPattern currentPattern) {
4970 Type existingPatternType = types.erasure(existingPattern.type);
4971 Type currentPatternType = types.erasure(currentPattern.type);
4972 if (!types.isUnconditionallyExact(currentPatternType, existingPatternType)) {
4973 return false;
4974 }
4975 if (currentPattern instanceof JCBindingPattern ||
4976 currentPattern instanceof JCAnyPattern) {
4977 return existingPattern instanceof JCBindingPattern ||
4978 existingPattern instanceof JCAnyPattern;
4979 } else if (currentPattern instanceof JCRecordPattern currentRecordPattern) {
4980 if (existingPattern instanceof JCBindingPattern ||
4981 existingPattern instanceof JCAnyPattern) {
4982 return true;
4983 } else if (existingPattern instanceof JCRecordPattern existingRecordPattern) {
4984 List<JCPattern> existingNested = existingRecordPattern.nested;
4985 List<JCPattern> currentNested = currentRecordPattern.nested;
4986 if (existingNested.size() != currentNested.size()) {
4987 return false;
4988 }
4989 while (existingNested.nonEmpty()) {
4990 if (!patternDominated(existingNested.head, currentNested.head)) {
4991 return false;
4992 }
4993 existingNested = existingNested.tail;
4994 currentNested = currentNested.tail;
4995 }
4996 return true;
4997 } else {
4998 Assert.error("Unknown pattern: " + existingPattern.getTag());
4999 }
5000 } else {
5001 Assert.error("Unknown pattern: " + currentPattern.getTag());
5002 }
5003 return false;
5004 }
5005
5006 /** check if a type is a subtype of Externalizable, if that is available. */
5007 boolean isExternalizable(Type t) {
5008 try {
5009 syms.externalizableType.complete();
5010 } catch (CompletionFailure e) {
5011 return false;
5012 }
5013 return types.isSubtype(t, syms.externalizableType);
5014 }
5015
5016 /**
5017 * Check structure of serialization declarations.
5018 */
5019 public void checkSerialStructure(Env<AttrContext> env, JCClassDecl tree, ClassSymbol c) {
5020 (new SerialTypeVisitor(env)).visit(c, tree);
5021 }
5022
5023 /**
5024 * This visitor will warn if a serialization-related field or
5025 * method is declared in a suspicious or incorrect way. In
5026 * particular, it will warn for cases where the runtime
5027 * serialization mechanism will silently ignore a mis-declared
5028 * entity.
5029 *
5030 * Distinguished serialization-related fields and methods:
5031 *
5032 * Methods:
5033 *
5034 * private void writeObject(ObjectOutputStream stream) throws IOException
5035 * ANY-ACCESS-MODIFIER Object writeReplace() throws ObjectStreamException
5036 *
5037 * private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException
5038 * private void readObjectNoData() throws ObjectStreamException
5039 * ANY-ACCESS-MODIFIER Object readResolve() throws ObjectStreamException
5040 *
5041 * Fields:
5042 *
5043 * private static final long serialVersionUID
5044 * private static final ObjectStreamField[] serialPersistentFields
5045 *
5046 * Externalizable: methods defined on the interface
5047 * public void writeExternal(ObjectOutput) throws IOException
5048 * public void readExternal(ObjectInput) throws IOException
5049 */
5050 private class SerialTypeVisitor extends ElementKindVisitor14<Void, JCClassDecl> {
5051 Env<AttrContext> env;
5052 SerialTypeVisitor(Env<AttrContext> env) {
5053 this.lint = Check.this.lint;
5054 this.env = env;
5055 }
5056
5057 private static final Set<String> serialMethodNames =
5058 Set.of("writeObject", "writeReplace",
5059 "readObject", "readObjectNoData",
5060 "readResolve");
5061
5062 private static final Set<String> serialFieldNames =
5063 Set.of("serialVersionUID", "serialPersistentFields");
5064
5065 // Type of serialPersistentFields
5066 private final Type OSF_TYPE = new Type.ArrayType(syms.objectStreamFieldType, syms.arrayClass);
5067
5068 Lint lint;
5069
5070 @Override
5071 public Void defaultAction(Element e, JCClassDecl p) {
5072 throw new IllegalArgumentException(Objects.requireNonNullElse(e.toString(), ""));
5073 }
5074
5075 @Override
5076 public Void visitType(TypeElement e, JCClassDecl p) {
5077 runUnderLint(e, p, (symbol, param) -> super.visitType(symbol, param));
5078 return null;
5079 }
5080
5081 @Override
5082 public Void visitTypeAsClass(TypeElement e,
5083 JCClassDecl p) {
5084 // Anonymous classes filtered out by caller.
5085
5086 ClassSymbol c = (ClassSymbol)e;
5087
5088 checkCtorAccess(p, c);
5089
5090 // Check for missing serialVersionUID; check *not* done
5091 // for enums or records.
5092 VarSymbol svuidSym = null;
5093 for (Symbol sym : c.members().getSymbolsByName(names.serialVersionUID)) {
5094 if (sym.kind == VAR) {
5095 svuidSym = (VarSymbol)sym;
5096 break;
5097 }
5098 }
5099
5100 if (svuidSym == null) {
5101 log.warning(p.pos(), LintWarnings.MissingSVUID(c));
5102 }
5103
5104 // Check for serialPersistentFields to gate checks for
5105 // non-serializable non-transient instance fields
5106 boolean serialPersistentFieldsPresent =
5107 c.members()
5108 .getSymbolsByName(names.serialPersistentFields, sym -> sym.kind == VAR)
5109 .iterator()
5110 .hasNext();
5111
5112 // Check declarations of serialization-related methods and
5113 // fields
5114 final boolean[] hasWriteReplace = {false};
5115 for(Symbol el : c.getEnclosedElements()) {
5116 runUnderLint(el, p, (enclosed, tree) -> {
5117 String name = null;
5118 switch(enclosed.getKind()) {
5119 case FIELD -> {
5120 if (!serialPersistentFieldsPresent) {
5121 var flags = enclosed.flags();
5122 if ( ((flags & TRANSIENT) == 0) &&
5123 ((flags & STATIC) == 0)) {
5124 Type varType = enclosed.asType();
5125 if (!canBeSerialized(varType)) {
5126 // Note per JLS arrays are
5127 // serializable even if the
5128 // component type is not.
5129 log.warning(
5130 TreeInfo.diagnosticPositionFor(enclosed, tree),
5131 LintWarnings.NonSerializableInstanceField);
5132 } else if (varType.hasTag(ARRAY)) {
5133 ArrayType arrayType = (ArrayType)varType;
5134 Type elementType = arrayType.elemtype;
5135 while (elementType.hasTag(ARRAY)) {
5136 arrayType = (ArrayType)elementType;
5137 elementType = arrayType.elemtype;
5138 }
5139 if (!canBeSerialized(elementType)) {
5140 log.warning(
5141 TreeInfo.diagnosticPositionFor(enclosed, tree),
5142 LintWarnings.NonSerializableInstanceFieldArray(elementType));
5143 }
5144 }
5145 }
5146 }
5147
5148 name = enclosed.getSimpleName().toString();
5149 if (serialFieldNames.contains(name)) {
5150 VarSymbol field = (VarSymbol)enclosed;
5151 switch (name) {
5152 case "serialVersionUID" -> checkSerialVersionUID(tree, e, field);
5153 case "serialPersistentFields" -> checkSerialPersistentFields(tree, e, field);
5154 default -> throw new AssertionError();
5155 }
5156 }
5157 }
5158
5159 // Correctly checking the serialization-related
5160 // methods is subtle. For the methods declared to be
5161 // private or directly declared in the class, the
5162 // enclosed elements of the class can be checked in
5163 // turn. However, writeReplace and readResolve can be
5164 // declared in a superclass and inherited. Note that
5165 // the runtime lookup walks the superclass chain
5166 // looking for writeReplace/readResolve via
5167 // Class.getDeclaredMethod. This differs from calling
5168 // Elements.getAllMembers(TypeElement) as the latter
5169 // will also pull in default methods from
5170 // superinterfaces. In other words, the runtime checks
5171 // (which long predate default methods on interfaces)
5172 // do not admit the possibility of inheriting methods
5173 // this way, a difference from general inheritance.
5174
5175 // The current implementation just checks the enclosed
5176 // elements and does not directly check the inherited
5177 // methods. If all the types are being checked this is
5178 // less of a concern; however, there are cases that
5179 // could be missed. In particular, readResolve and
5180 // writeReplace could, in principle, by inherited from
5181 // a non-serializable superclass and thus not checked
5182 // even if compiled with a serializable child class.
5183 case METHOD -> {
5184 var method = (MethodSymbol)enclosed;
5185 name = method.getSimpleName().toString();
5186 if (serialMethodNames.contains(name)) {
5187 switch (name) {
5188 case "writeObject" -> checkWriteObject(tree, e, method);
5189 case "writeReplace" -> {hasWriteReplace[0] = true; hasAppropriateWriteReplace(tree, method, true);}
5190 case "readObject" -> checkReadObject(tree,e, method);
5191 case "readObjectNoData" -> checkReadObjectNoData(tree, e, method);
5192 case "readResolve" -> checkReadResolve(tree, e, method);
5193 default -> throw new AssertionError();
5194 }
5195 }
5196 }
5197 }
5198 });
5199 }
5200 if (!hasWriteReplace[0] &&
5201 (c.isValueClass() || hasAbstractValueSuperClass(c, Set.of(syms.numberType.tsym))) &&
5202 !c.isAbstract() && !c.isRecord() &&
5203 types.unboxedType(c.type) == Type.noType) {
5204 // we need to check if the class is inheriting an appropriate writeReplace method
5205 MethodSymbol ms = null;
5206 Log.DiagnosticHandler discardHandler = log.new DiscardDiagnosticHandler();
5207 try {
5208 ms = rs.resolveInternalMethod(env.tree, env, c.type, names.writeReplace, List.nil(), List.nil());
5209 } catch (FatalError fe) {
5210 // ignore no method was found
5211 } finally {
5212 log.popDiagnosticHandler(discardHandler);
5213 }
5214 if (ms == null || !hasAppropriateWriteReplace(p, ms, false)) {
5215 log.warning(p.pos(),
5216 c.isValueClass() ? LintWarnings.SerializableValueClassWithoutWriteReplace1 :
5217 LintWarnings.SerializableValueClassWithoutWriteReplace2);
5218 }
5219 }
5220 return null;
5221 }
5222
5223 boolean canBeSerialized(Type type) {
5224 return type.isPrimitive() || rs.isSerializable(type);
5225 }
5226
5227 private boolean hasAbstractValueSuperClass(Symbol c, Set<Symbol> excluding) {
5228 while (c.getKind() == ElementKind.CLASS) {
5229 Type sup = ((ClassSymbol)c).getSuperclass();
5230 if (!sup.hasTag(CLASS) || sup.isErroneous() ||
5231 sup.tsym == syms.objectType.tsym) {
5232 return false;
5233 }
5234 // if it is a value super class it has to be abstract
5235 if (sup.isValueClass() && !excluding.contains(sup.tsym)) {
5236 return true;
5237 }
5238 c = sup.tsym;
5239 }
5240 return false;
5241 }
5242
5243 /**
5244 * Check that Externalizable class needs a public no-arg
5245 * constructor.
5246 *
5247 * Check that a Serializable class has access to the no-arg
5248 * constructor of its first nonserializable superclass.
5249 */
5250 private void checkCtorAccess(JCClassDecl tree, ClassSymbol c) {
5251 if (isExternalizable(c.type)) {
5252 for(var sym : c.getEnclosedElements()) {
5253 if (sym.isConstructor() &&
5254 ((sym.flags() & PUBLIC) == PUBLIC)) {
5255 if (((MethodSymbol)sym).getParameters().isEmpty()) {
5256 return;
5257 }
5258 }
5259 }
5260 log.warning(tree.pos(),
5261 LintWarnings.ExternalizableMissingPublicNoArgCtor);
5262 } else {
5263 // Approximate access to the no-arg constructor up in
5264 // the superclass chain by checking that the
5265 // constructor is not private. This may not handle
5266 // some cross-package situations correctly.
5267 Type superClass = c.getSuperclass();
5268 // java.lang.Object is *not* Serializable so this loop
5269 // should terminate.
5270 while (rs.isSerializable(superClass) ) {
5271 try {
5272 superClass = (Type)((TypeElement)(((DeclaredType)superClass)).asElement()).getSuperclass();
5273 } catch(ClassCastException cce) {
5274 return ; // Don't try to recover
5275 }
5276 }
5277 // Non-Serializable superclass
5278 try {
5279 ClassSymbol supertype = ((ClassSymbol)(((DeclaredType)superClass).asElement()));
5280 for(var sym : supertype.getEnclosedElements()) {
5281 if (sym.isConstructor()) {
5282 MethodSymbol ctor = (MethodSymbol)sym;
5283 if (ctor.getParameters().isEmpty()) {
5284 if (((ctor.flags() & PRIVATE) == PRIVATE) ||
5285 // Handle nested classes and implicit this$0
5286 (supertype.getNestingKind() == NestingKind.MEMBER &&
5287 ((supertype.flags() & STATIC) == 0)))
5288 log.warning(tree.pos(),
5289 LintWarnings.SerializableMissingAccessNoArgCtor(supertype.getQualifiedName()));
5290 }
5291 }
5292 }
5293 } catch (ClassCastException cce) {
5294 return ; // Don't try to recover
5295 }
5296 return;
5297 }
5298 }
5299
5300 private void checkSerialVersionUID(JCClassDecl tree, Element e, VarSymbol svuid) {
5301 // To be effective, serialVersionUID must be marked static
5302 // and final, but private is recommended. But alas, in
5303 // practice there are many non-private serialVersionUID
5304 // fields.
5305 if ((svuid.flags() & (STATIC | FINAL)) !=
5306 (STATIC | FINAL)) {
5307 log.warning(
5308 TreeInfo.diagnosticPositionFor(svuid, tree),
5309 LintWarnings.ImproperSVUID((Symbol)e));
5310 }
5311
5312 // check svuid has type long
5313 if (!svuid.type.hasTag(LONG)) {
5314 log.warning(
5315 TreeInfo.diagnosticPositionFor(svuid, tree),
5316 LintWarnings.LongSVUID((Symbol)e));
5317 }
5318
5319 if (svuid.getConstValue() == null)
5320 log.warning(
5321 TreeInfo.diagnosticPositionFor(svuid, tree),
5322 LintWarnings.ConstantSVUID((Symbol)e));
5323 }
5324
5325 private void checkSerialPersistentFields(JCClassDecl tree, Element e, VarSymbol spf) {
5326 // To be effective, serialPersisentFields must be private, static, and final.
5327 if ((spf.flags() & (PRIVATE | STATIC | FINAL)) !=
5328 (PRIVATE | STATIC | FINAL)) {
5329 log.warning(
5330 TreeInfo.diagnosticPositionFor(spf, tree),
5331 LintWarnings.ImproperSPF);
5332 }
5333
5334 if (!types.isSameType(spf.type, OSF_TYPE)) {
5335 log.warning(
5336 TreeInfo.diagnosticPositionFor(spf, tree),
5337 LintWarnings.OSFArraySPF);
5338 }
5339
5340 if (isExternalizable((Type)(e.asType()))) {
5341 log.warning(
5342 TreeInfo.diagnosticPositionFor(spf, tree),
5343 LintWarnings.IneffectualSerialFieldExternalizable);
5344 }
5345
5346 // Warn if serialPersistentFields is initialized to a
5347 // literal null.
5348 JCTree spfDecl = TreeInfo.declarationFor(spf, tree);
5349 if (spfDecl != null && spfDecl.getTag() == VARDEF) {
5350 JCVariableDecl variableDef = (JCVariableDecl) spfDecl;
5351 JCExpression initExpr = variableDef.init;
5352 if (initExpr != null && TreeInfo.isNull(initExpr)) {
5353 log.warning(initExpr.pos(),
5354 LintWarnings.SPFNullInit);
5355 }
5356 }
5357 }
5358
5359 private void checkWriteObject(JCClassDecl tree, Element e, MethodSymbol method) {
5360 // The "synchronized" modifier is seen in the wild on
5361 // readObject and writeObject methods and is generally
5362 // innocuous.
5363
5364 // private void writeObject(ObjectOutputStream stream) throws IOException
5365 checkPrivateNonStaticMethod(tree, method);
5366 isExpectedReturnType(tree, method, syms.voidType, true);
5367 checkOneArg(tree, e, method, syms.objectOutputStreamType);
5368 hasExpectedExceptions(tree, method, true, syms.ioExceptionType);
5369 checkExternalizable(tree, e, method);
5370 }
5371
5372 private boolean hasAppropriateWriteReplace(JCClassDecl tree, MethodSymbol method, boolean warn) {
5373 // ANY-ACCESS-MODIFIER Object writeReplace() throws
5374 // ObjectStreamException
5375
5376 // Excluding abstract, could have a more complicated
5377 // rule based on abstract-ness of the class
5378 return isConcreteInstanceMethod(tree, method, warn) &&
5379 isExpectedReturnType(tree, method, syms.objectType, warn) &&
5380 hasNoArgs(tree, method, warn) &&
5381 hasExpectedExceptions(tree, method, warn, syms.objectStreamExceptionType);
5382 }
5383
5384 private void checkReadObject(JCClassDecl tree, Element e, MethodSymbol method) {
5385 // The "synchronized" modifier is seen in the wild on
5386 // readObject and writeObject methods and is generally
5387 // innocuous.
5388
5389 // private void readObject(ObjectInputStream stream)
5390 // throws IOException, ClassNotFoundException
5391 checkPrivateNonStaticMethod(tree, method);
5392 isExpectedReturnType(tree, method, syms.voidType, true);
5393 checkOneArg(tree, e, method, syms.objectInputStreamType);
5394 hasExpectedExceptions(tree, method, true, syms.ioExceptionType, syms.classNotFoundExceptionType);
5395 checkExternalizable(tree, e, method);
5396 }
5397
5398 private void checkReadObjectNoData(JCClassDecl tree, Element e, MethodSymbol method) {
5399 // private void readObjectNoData() throws ObjectStreamException
5400 checkPrivateNonStaticMethod(tree, method);
5401 isExpectedReturnType(tree, method, syms.voidType, true);
5402 hasNoArgs(tree, method, true);
5403 hasExpectedExceptions(tree, method, true, syms.objectStreamExceptionType);
5404 checkExternalizable(tree, e, method);
5405 }
5406
5407 private void checkReadResolve(JCClassDecl tree, Element e, MethodSymbol method) {
5408 // ANY-ACCESS-MODIFIER Object readResolve()
5409 // throws ObjectStreamException
5410
5411 // Excluding abstract, could have a more complicated
5412 // rule based on abstract-ness of the class
5413 isConcreteInstanceMethod(tree, method, true);
5414 isExpectedReturnType(tree, method, syms.objectType, true);
5415 hasNoArgs(tree, method, true);
5416 hasExpectedExceptions(tree, method, true, syms.objectStreamExceptionType);
5417 }
5418
5419 private void checkWriteExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5420 //public void writeExternal(ObjectOutput) throws IOException
5421 checkExternMethodRecord(tree, e, method, syms.objectOutputType, isExtern);
5422 }
5423
5424 private void checkReadExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5425 // public void readExternal(ObjectInput) throws IOException
5426 checkExternMethodRecord(tree, e, method, syms.objectInputType, isExtern);
5427 }
5428
5429 private void checkExternMethodRecord(JCClassDecl tree, Element e, MethodSymbol method, Type argType,
5430 boolean isExtern) {
5431 if (isExtern && isExternMethod(tree, e, method, argType)) {
5432 log.warning(
5433 TreeInfo.diagnosticPositionFor(method, tree),
5434 LintWarnings.IneffectualExternalizableMethodRecord(method.getSimpleName().toString()));
5435 }
5436 }
5437
5438 void checkPrivateNonStaticMethod(JCClassDecl tree, MethodSymbol method) {
5439 var flags = method.flags();
5440 if ((flags & PRIVATE) == 0) {
5441 log.warning(
5442 TreeInfo.diagnosticPositionFor(method, tree),
5443 LintWarnings.SerialMethodNotPrivate(method.getSimpleName()));
5444 }
5445
5446 if ((flags & STATIC) != 0) {
5447 log.warning(
5448 TreeInfo.diagnosticPositionFor(method, tree),
5449 LintWarnings.SerialMethodStatic(method.getSimpleName()));
5450 }
5451 }
5452
5453 /**
5454 * Per section 1.12 "Serialization of Enum Constants" of
5455 * the serialization specification, due to the special
5456 * serialization handling of enums, any writeObject,
5457 * readObject, writeReplace, and readResolve methods are
5458 * ignored as are serialPersistentFields and
5459 * serialVersionUID fields.
5460 */
5461 @Override
5462 public Void visitTypeAsEnum(TypeElement e,
5463 JCClassDecl p) {
5464 boolean isExtern = isExternalizable((Type)e.asType());
5465 for(Element el : e.getEnclosedElements()) {
5466 runUnderLint(el, p, (enclosed, tree) -> {
5467 String name = enclosed.getSimpleName().toString();
5468 switch(enclosed.getKind()) {
5469 case FIELD -> {
5470 var field = (VarSymbol)enclosed;
5471 if (serialFieldNames.contains(name)) {
5472 log.warning(
5473 TreeInfo.diagnosticPositionFor(field, tree),
5474 LintWarnings.IneffectualSerialFieldEnum(name));
5475 }
5476 }
5477
5478 case METHOD -> {
5479 var method = (MethodSymbol)enclosed;
5480 if (serialMethodNames.contains(name)) {
5481 log.warning(
5482 TreeInfo.diagnosticPositionFor(method, tree),
5483 LintWarnings.IneffectualSerialMethodEnum(name));
5484 }
5485
5486 if (isExtern) {
5487 switch(name) {
5488 case "writeExternal" -> checkWriteExternalEnum(tree, e, method);
5489 case "readExternal" -> checkReadExternalEnum(tree, e, method);
5490 }
5491 }
5492 }
5493
5494 // Also perform checks on any class bodies of enum constants, see JLS 8.9.1.
5495 case ENUM_CONSTANT -> {
5496 var field = (VarSymbol)enclosed;
5497 JCVariableDecl decl = (JCVariableDecl) TreeInfo.declarationFor(field, p);
5498 if (decl.init instanceof JCNewClass nc && nc.def != null) {
5499 ClassSymbol enumConstantType = nc.def.sym;
5500 visitTypeAsEnum(enumConstantType, p);
5501 }
5502 }
5503
5504 }});
5505 }
5506 return null;
5507 }
5508
5509 private void checkWriteExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5510 //public void writeExternal(ObjectOutput) throws IOException
5511 checkExternMethodEnum(tree, e, method, syms.objectOutputType);
5512 }
5513
5514 private void checkReadExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5515 // public void readExternal(ObjectInput) throws IOException
5516 checkExternMethodEnum(tree, e, method, syms.objectInputType);
5517 }
5518
5519 private void checkExternMethodEnum(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5520 if (isExternMethod(tree, e, method, argType)) {
5521 log.warning(
5522 TreeInfo.diagnosticPositionFor(method, tree),
5523 LintWarnings.IneffectualExternMethodEnum(method.getSimpleName().toString()));
5524 }
5525 }
5526
5527 private boolean isExternMethod(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5528 long flags = method.flags();
5529 Type rtype = method.getReturnType();
5530
5531 // Not necessary to check throws clause in this context
5532 return (flags & PUBLIC) != 0 && (flags & STATIC) == 0 &&
5533 types.isSameType(syms.voidType, rtype) &&
5534 hasExactlyOneArgWithType(tree, e, method, argType);
5535 }
5536
5537 /**
5538 * Most serialization-related fields and methods on interfaces
5539 * are ineffectual or problematic.
5540 */
5541 @Override
5542 public Void visitTypeAsInterface(TypeElement e,
5543 JCClassDecl p) {
5544 for(Element el : e.getEnclosedElements()) {
5545 runUnderLint(el, p, (enclosed, tree) -> {
5546 String name = null;
5547 switch(enclosed.getKind()) {
5548 case FIELD -> {
5549 var field = (VarSymbol)enclosed;
5550 name = field.getSimpleName().toString();
5551 switch(name) {
5552 case "serialPersistentFields" -> {
5553 log.warning(
5554 TreeInfo.diagnosticPositionFor(field, tree),
5555 LintWarnings.IneffectualSerialFieldInterface);
5556 }
5557
5558 case "serialVersionUID" -> {
5559 checkSerialVersionUID(tree, e, field);
5560 }
5561 }
5562 }
5563
5564 case METHOD -> {
5565 var method = (MethodSymbol)enclosed;
5566 name = enclosed.getSimpleName().toString();
5567 if (serialMethodNames.contains(name)) {
5568 switch (name) {
5569 case
5570 "readObject",
5571 "readObjectNoData",
5572 "writeObject" -> checkPrivateMethod(tree, e, method);
5573
5574 case
5575 "writeReplace",
5576 "readResolve" -> checkDefaultIneffective(tree, e, method);
5577
5578 default -> throw new AssertionError();
5579 }
5580
5581 }
5582 }}
5583 });
5584 }
5585
5586 return null;
5587 }
5588
5589 private void checkPrivateMethod(JCClassDecl tree,
5590 Element e,
5591 MethodSymbol method) {
5592 if ((method.flags() & PRIVATE) == 0) {
5593 log.warning(
5594 TreeInfo.diagnosticPositionFor(method, tree),
5595 LintWarnings.NonPrivateMethodWeakerAccess);
5596 }
5597 }
5598
5599 private void checkDefaultIneffective(JCClassDecl tree,
5600 Element e,
5601 MethodSymbol method) {
5602 if ((method.flags() & DEFAULT) == DEFAULT) {
5603 log.warning(
5604 TreeInfo.diagnosticPositionFor(method, tree),
5605 LintWarnings.DefaultIneffective);
5606
5607 }
5608 }
5609
5610 @Override
5611 public Void visitTypeAsAnnotationType(TypeElement e,
5612 JCClassDecl p) {
5613 // Per the JLS, annotation types are not serializeable
5614 return null;
5615 }
5616
5617 /**
5618 * From the Java Object Serialization Specification, 1.13
5619 * Serialization of Records:
5620 *
5621 * "The process by which record objects are serialized or
5622 * externalized cannot be customized; any class-specific
5623 * writeObject, readObject, readObjectNoData, writeExternal,
5624 * and readExternal methods defined by record classes are
5625 * ignored during serialization and deserialization. However,
5626 * a substitute object to be serialized or a designate
5627 * replacement may be specified, by the writeReplace and
5628 * readResolve methods, respectively. Any
5629 * serialPersistentFields field declaration is
5630 * ignored. Documenting serializable fields and data for
5631 * record classes is unnecessary, since there is no variation
5632 * in the serial form, other than whether a substitute or
5633 * replacement object is used. The serialVersionUID of a
5634 * record class is 0L unless explicitly declared. The
5635 * requirement for matching serialVersionUID values is waived
5636 * for record classes."
5637 */
5638 @Override
5639 public Void visitTypeAsRecord(TypeElement e,
5640 JCClassDecl p) {
5641 boolean isExtern = isExternalizable((Type)e.asType());
5642 for(Element el : e.getEnclosedElements()) {
5643 runUnderLint(el, p, (enclosed, tree) -> {
5644 String name = enclosed.getSimpleName().toString();
5645 switch(enclosed.getKind()) {
5646 case FIELD -> {
5647 var field = (VarSymbol)enclosed;
5648 switch(name) {
5649 case "serialPersistentFields" -> {
5650 log.warning(
5651 TreeInfo.diagnosticPositionFor(field, tree),
5652 LintWarnings.IneffectualSerialFieldRecord);
5653 }
5654
5655 case "serialVersionUID" -> {
5656 // Could generate additional warning that
5657 // svuid value is not checked to match for
5658 // records.
5659 checkSerialVersionUID(tree, e, field);
5660 }}
5661 }
5662
5663 case METHOD -> {
5664 var method = (MethodSymbol)enclosed;
5665 switch(name) {
5666 case "writeReplace" -> hasAppropriateWriteReplace(tree, method, true);
5667 case "readResolve" -> checkReadResolve(tree, e, method);
5668
5669 case "writeExternal" -> checkWriteExternalRecord(tree, e, method, isExtern);
5670 case "readExternal" -> checkReadExternalRecord(tree, e, method, isExtern);
5671
5672 default -> {
5673 if (serialMethodNames.contains(name)) {
5674 log.warning(
5675 TreeInfo.diagnosticPositionFor(method, tree),
5676 LintWarnings.IneffectualSerialMethodRecord(name));
5677 }
5678 }}
5679 }}});
5680 }
5681 return null;
5682 }
5683
5684 boolean isConcreteInstanceMethod(JCClassDecl tree,
5685 MethodSymbol method,
5686 boolean warn) {
5687 if ((method.flags() & (STATIC | ABSTRACT)) != 0) {
5688 if (warn) {
5689 log.warning(
5690 TreeInfo.diagnosticPositionFor(method, tree),
5691 LintWarnings.SerialConcreteInstanceMethod(method.getSimpleName()));
5692 }
5693 return false;
5694 }
5695 return true;
5696 }
5697
5698 private boolean isExpectedReturnType(JCClassDecl tree,
5699 MethodSymbol method,
5700 Type expectedReturnType,
5701 boolean warn) {
5702 // Note: there may be complications checking writeReplace
5703 // and readResolve since they return Object and could, in
5704 // principle, have covariant overrides and any synthetic
5705 // bridge method would not be represented here for
5706 // checking.
5707 Type rtype = method.getReturnType();
5708 if (!types.isSameType(expectedReturnType, rtype)) {
5709 if (warn) {
5710 log.warning(
5711 TreeInfo.diagnosticPositionFor(method, tree),
5712 LintWarnings.SerialMethodUnexpectedReturnType(method.getSimpleName(),
5713 rtype, expectedReturnType));
5714 }
5715 return false;
5716 }
5717 return true;
5718 }
5719
5720 private void checkOneArg(JCClassDecl tree,
5721 Element enclosing,
5722 MethodSymbol method,
5723 Type expectedType) {
5724 String name = method.getSimpleName().toString();
5725
5726 var parameters= method.getParameters();
5727
5728 if (parameters.size() != 1) {
5729 log.warning(
5730 TreeInfo.diagnosticPositionFor(method, tree),
5731 LintWarnings.SerialMethodOneArg(method.getSimpleName(), parameters.size()));
5732 return;
5733 }
5734
5735 Type parameterType = parameters.get(0).asType();
5736 if (!types.isSameType(parameterType, expectedType)) {
5737 log.warning(
5738 TreeInfo.diagnosticPositionFor(method, tree),
5739 LintWarnings.SerialMethodParameterType(method.getSimpleName(),
5740 expectedType,
5741 parameterType));
5742 }
5743 }
5744
5745 private boolean hasExactlyOneArgWithType(JCClassDecl tree,
5746 Element enclosing,
5747 MethodSymbol method,
5748 Type expectedType) {
5749 var parameters = method.getParameters();
5750 return (parameters.size() == 1) &&
5751 types.isSameType(parameters.get(0).asType(), expectedType);
5752 }
5753
5754
5755 boolean hasNoArgs(JCClassDecl tree, MethodSymbol method, boolean warn) {
5756 var parameters = method.getParameters();
5757 if (!parameters.isEmpty()) {
5758 if (warn) {
5759 log.warning(
5760 TreeInfo.diagnosticPositionFor(parameters.get(0), tree),
5761 LintWarnings.SerialMethodNoArgs(method.getSimpleName()));
5762 }
5763 return false;
5764 }
5765 return true;
5766 }
5767
5768 private void checkExternalizable(JCClassDecl tree, Element enclosing, MethodSymbol method) {
5769 // If the enclosing class is externalizable, warn for the method
5770 if (isExternalizable((Type)enclosing.asType())) {
5771 log.warning(
5772 TreeInfo.diagnosticPositionFor(method, tree),
5773 LintWarnings.IneffectualSerialMethodExternalizable(method.getSimpleName()));
5774 }
5775 return;
5776 }
5777
5778 private boolean hasExpectedExceptions(JCClassDecl tree,
5779 MethodSymbol method,
5780 boolean warn,
5781 Type... declaredExceptions) {
5782 for (Type thrownType: method.getThrownTypes()) {
5783 // For each exception in the throws clause of the
5784 // method, if not an Error and not a RuntimeException,
5785 // check if the exception is a subtype of a declared
5786 // exception from the throws clause of the
5787 // serialization method in question.
5788 if (types.isSubtype(thrownType, syms.runtimeExceptionType) ||
5789 types.isSubtype(thrownType, syms.errorType) ) {
5790 continue;
5791 } else {
5792 boolean declared = false;
5793 for (Type declaredException : declaredExceptions) {
5794 if (types.isSubtype(thrownType, declaredException)) {
5795 declared = true;
5796 continue;
5797 }
5798 }
5799 if (!declared) {
5800 if (warn) {
5801 log.warning(
5802 TreeInfo.diagnosticPositionFor(method, tree),
5803 LintWarnings.SerialMethodUnexpectedException(method.getSimpleName(),
5804 thrownType));
5805 }
5806 return false;
5807 }
5808 }
5809 }
5810 return true;
5811 }
5812
5813 private <E extends Element> Void runUnderLint(E symbol, JCClassDecl p, BiConsumer<E, JCClassDecl> task) {
5814 Lint prevLint = lint;
5815 try {
5816 lint = lint.augment((Symbol) symbol);
5817
5818 if (lint.isEnabled(LintCategory.SERIAL)) {
5819 task.accept(symbol, p);
5820 }
5821
5822 return null;
5823 } finally {
5824 lint = prevLint;
5825 }
5826 }
5827
5828 }
5829
5830 void checkRequiresIdentity(JCTree tree, Lint lint) {
5831 switch (tree) {
5832 case JCClassDecl classDecl -> {
5833 Type st = types.supertype(classDecl.sym.type);
5834 if (st != null &&
5835 // no need to recheck j.l.Object, shortcut,
5836 st.tsym != syms.objectType.tsym &&
5837 // this one could be null, no explicit extends
5838 classDecl.extending != null) {
5839 checkIfIdentityIsExpected(classDecl.extending.pos(), st, lint);
5840 }
5841 for (JCExpression intrface: classDecl.implementing) {
5842 checkIfIdentityIsExpected(intrface.pos(), intrface.type, lint);
5843 }
5844 for (JCTypeParameter tp : classDecl.typarams) {
5845 checkIfIdentityIsExpected(tp.pos(), tp.type, lint);
5846 }
5847 }
5848 case JCVariableDecl variableDecl -> {
5849 if (variableDecl.vartype != null &&
5850 (variableDecl.sym.flags_field & RECORD) == 0 ||
5851 (variableDecl.sym.flags_field & ~(Flags.PARAMETER | RECORD | GENERATED_MEMBER)) != 0) {
5852 /* we don't want to warn twice so if this variable is a compiler generated parameter of
5853 * a canonical record constructor, we don't want to issue a warning as we will warn the
5854 * corresponding compiler generated private record field anyways
5855 */
5856 checkIfIdentityIsExpected(variableDecl.vartype.pos(), variableDecl.vartype.type, lint);
5857 }
5858 }
5859 case JCTypeCast typeCast -> checkIfIdentityIsExpected(typeCast.clazz.pos(), typeCast.clazz.type, lint);
5860 case JCBindingPattern bindingPattern -> {
5861 if (bindingPattern.var.vartype != null) {
5862 checkIfIdentityIsExpected(bindingPattern.var.vartype.pos(), bindingPattern.var.vartype.type, lint);
5863 }
5864 }
5865 case JCMethodDecl methodDecl -> {
5866 for (JCTypeParameter tp : methodDecl.typarams) {
5867 checkIfIdentityIsExpected(tp.pos(), tp.type, lint);
5868 }
5869 if (methodDecl.restype != null && !methodDecl.restype.type.hasTag(VOID)) {
5870 checkIfIdentityIsExpected(methodDecl.restype.pos(), methodDecl.restype.type, lint);
5871 }
5872 }
5873 case JCMemberReference mref -> {
5874 checkIfIdentityIsExpected(mref.expr.pos(), mref.target, lint);
5875 checkIfTypeParamsRequiresIdentity(mref.sym.getMetadata(), mref.typeargs, lint);
5876 }
5877 case JCPolyExpression poly
5878 when (poly instanceof JCNewClass || poly instanceof JCMethodInvocation) -> {
5879 if (poly instanceof JCNewClass newClass) {
5880 checkIfIdentityIsExpected(newClass.clazz.pos(), newClass.clazz.type, lint);
5881 }
5882 List<JCExpression> argExps = poly instanceof JCNewClass ?
5883 ((JCNewClass)poly).args :
5884 ((JCMethodInvocation)poly).args;
5885 Symbol msym = TreeInfo.symbolFor(poly);
5886 if (msym != null) {
5887 if (!argExps.isEmpty() && msym instanceof MethodSymbol ms && ms.params != null) {
5888 VarSymbol lastParam = ms.params.head;
5889 for (VarSymbol param: ms.params) {
5890 if ((param.flags_field & REQUIRES_IDENTITY) != 0 && argExps.head.type.isValueBased()) {
5891 lint.logIfEnabled(argExps.head.pos(), LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5892 }
5893 lastParam = param;
5894 argExps = argExps.tail;
5895 }
5896 while (argExps != null && !argExps.isEmpty() && lastParam != null) {
5897 if ((lastParam.flags_field & REQUIRES_IDENTITY) != 0 && argExps.head.type.isValueBased()) {
5898 lint.logIfEnabled(argExps.head.pos(), LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5899 }
5900 argExps = argExps.tail;
5901 }
5902 }
5903 checkIfTypeParamsRequiresIdentity(
5904 msym.getMetadata(),
5905 poly instanceof JCNewClass ?
5906 ((JCNewClass)poly).typeargs :
5907 ((JCMethodInvocation)poly).typeargs,
5908 lint);
5909 }
5910 }
5911 default -> throw new AssertionError("unexpected tree " + tree);
5912 }
5913 }
5914
5915 /** Check if a type required an identity class
5916 */
5917 private boolean checkIfIdentityIsExpected(DiagnosticPosition pos, Type t, Lint lint) {
5918 if (t != null &&
5919 lint != null &&
5920 lint.isEnabled(LintCategory.IDENTITY)) {
5921 RequiresIdentityVisitor requiresIdentityVisitor = new RequiresIdentityVisitor();
5922 // we need to avoid recursion due to self referencing type vars or captures, this is why we need a set
5923 requiresIdentityVisitor.visit(t, new HashSet<>());
5924 if (requiresIdentityVisitor.requiresWarning) {
5925 lint.logIfEnabled(pos, LintWarnings.AttemptToUseValueBasedWhereIdentityExpected);
5926 return true;
5927 }
5928 }
5929 return false;
5930 }
5931
5932 // where
5933 private class RequiresIdentityVisitor extends Types.SimpleVisitor<Void, Set<Type>> {
5934 boolean requiresWarning = false;
5935
5936 @Override
5937 public Void visitType(Type t, Set<Type> seen) {
5938 return null;
5939 }
5940
5941 @Override
5942 public Void visitWildcardType(WildcardType t, Set<Type> seen) {
5943 return visit(t.type, seen);
5944 }
5945
5946 @Override
5947 public Void visitTypeVar(TypeVar t, Set<Type> seen) {
5948 if (seen.add(t)) {
5949 visit(t.getUpperBound(), seen);
5950 }
5951 return null;
5952 }
5953
5954 @Override
5955 public Void visitCapturedType(CapturedType t, Set<Type> seen) {
5956 if (seen.add(t)) {
5957 visit(t.getUpperBound(), seen);
5958 visit(t.getLowerBound(), seen);
5959 }
5960 return null;
5961 }
5962
5963 @Override
5964 public Void visitArrayType(ArrayType t, Set<Type> seen) {
5965 return visit(t.elemtype, seen);
5966 }
5967
5968 @Override
5969 public Void visitClassType(ClassType t, Set<Type> seen) {
5970 if (t != null && t.tsym != null) {
5971 SymbolMetadata sm = t.tsym.getMetadata();
5972 if (sm != null && !t.getTypeArguments().isEmpty()) {
5973 if (sm.getTypeAttributes().stream()
5974 .filter(ta -> isRequiresIdentityAnnotation(ta.type.tsym) &&
5975 t.getTypeArguments().get(ta.position.parameter_index) != null &&
5976 t.getTypeArguments().get(ta.position.parameter_index).isValueBased()).findAny().isPresent()) {
5977 requiresWarning = true;
5978 return null;
5979 }
5980 }
5981 }
5982 visit(t.getEnclosingType(), seen);
5983 for (Type targ : t.getTypeArguments()) {
5984 visit(targ, seen);
5985 }
5986 return null;
5987 }
5988 } // RequiresIdentityVisitor
5989
5990 private void checkIfTypeParamsRequiresIdentity(SymbolMetadata sm,
5991 List<JCExpression> typeParamTrees,
5992 Lint lint) {
5993 if (typeParamTrees != null && !typeParamTrees.isEmpty()) {
5994 for (JCExpression targ : typeParamTrees) {
5995 checkIfIdentityIsExpected(targ.pos(), targ.type, lint);
5996 }
5997 if (sm != null)
5998 sm.getTypeAttributes().stream()
5999 .filter(ta -> isRequiresIdentityAnnotation(ta.type.tsym) &&
6000 typeParamTrees.get(ta.position.parameter_index).type != null &&
6001 typeParamTrees.get(ta.position.parameter_index).type.isValueBased())
6002 .forEach(ta -> lint.logIfEnabled(typeParamTrees.get(ta.position.parameter_index).pos(),
6003 CompilerProperties.LintWarnings.AttemptToUseValueBasedWhereIdentityExpected));
6004 }
6005 }
6006
6007 private boolean isRequiresIdentityAnnotation(TypeSymbol annoType) {
6008 return annoType == syms.requiresIdentityType.tsym ||
6009 annoType.flatName() == syms.requiresIdentityInternalType.tsym.flatName();
6010 }
6011 }