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