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