1 /*
2 * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.comp;
27
28 import java.util.*;
29 import java.util.function.BiConsumer;
30 import java.util.function.BiPredicate;
31 import java.util.function.Consumer;
32 import java.util.function.Predicate;
33 import java.util.function.Supplier;
34 import java.util.function.ToIntBiFunction;
35 import java.util.stream.Collectors;
36 import java.util.stream.StreamSupport;
37
38 import javax.lang.model.element.ElementKind;
39 import javax.lang.model.element.NestingKind;
40 import javax.tools.JavaFileManager;
41
42 import com.sun.source.tree.CaseTree;
43 import com.sun.tools.javac.code.*;
44 import com.sun.tools.javac.code.Attribute.Compound;
45 import com.sun.tools.javac.code.Directive.ExportsDirective;
46 import com.sun.tools.javac.code.Directive.RequiresDirective;
47 import com.sun.tools.javac.code.Source.Feature;
48 import com.sun.tools.javac.comp.Annotate.AnnotationTypeMetadata;
49 import com.sun.tools.javac.jvm.*;
50 import com.sun.tools.javac.resources.CompilerProperties.Errors;
51 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
52 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
53 import com.sun.tools.javac.tree.*;
54 import com.sun.tools.javac.util.*;
55 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
56 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
57 import com.sun.tools.javac.util.JCDiagnostic.Error;
58 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
59 import com.sun.tools.javac.util.JCDiagnostic.Warning;
60 import com.sun.tools.javac.util.List;
61
62 import com.sun.tools.javac.code.Lint;
63 import com.sun.tools.javac.code.Lint.LintCategory;
64 import com.sun.tools.javac.code.Scope.WriteableScope;
65 import com.sun.tools.javac.code.Type.*;
66 import com.sun.tools.javac.code.Symbol.*;
67 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
68 import com.sun.tools.javac.tree.JCTree.*;
69
70 import static com.sun.tools.javac.code.Flags.*;
71 import static com.sun.tools.javac.code.Flags.ANNOTATION;
72 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED;
73 import static com.sun.tools.javac.code.Kinds.*;
74 import static com.sun.tools.javac.code.Kinds.Kind.*;
75 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
76 import static com.sun.tools.javac.code.Scope.LookupKind.RECURSIVE;
77 import static com.sun.tools.javac.code.TypeTag.*;
78 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
79
80 import static com.sun.tools.javac.tree.JCTree.Tag.*;
81 import javax.lang.model.element.Element;
82 import javax.lang.model.element.ExecutableElement;
83 import javax.lang.model.element.TypeElement;
84 import javax.lang.model.type.DeclaredType;
85 import javax.lang.model.type.TypeMirror;
86 import javax.lang.model.util.ElementFilter;
87 import javax.lang.model.util.ElementKindVisitor14;
88
89 /** Type checking helper class for the attribution phase.
90 *
91 * <p><b>This is NOT part of any supported API.
92 * If you write code that depends on this, you do so at your own risk.
93 * This code and its internal interfaces are subject to change or
94 * deletion without notice.</b>
95 */
96 public class Check {
97 protected static final Context.Key<Check> checkKey = new Context.Key<>();
98
99 // Flag bits indicating which item(s) chosen from a pair of items
100 private static final int FIRST = 0x01;
101 private static final int SECOND = 0x02;
102
103 private final Names names;
104 private final Log log;
105 private final Resolve rs;
106 private final Symtab syms;
107 private final Enter enter;
108 private final DeferredAttr deferredAttr;
109 private final Infer infer;
110 private final Types types;
111 private final TypeAnnotations typeAnnotations;
112 private final JCDiagnostic.Factory diags;
113 private final JavaFileManager fileManager;
114 private final Source source;
115 private final Target target;
116 private final Profile profile;
117 private final Preview preview;
118 private final boolean warnOnAnyAccessToMembers;
119
120 public boolean disablePreviewCheck;
121
122 // The set of lint options currently in effect. It is initialized
123 // from the context, and then is set/reset as needed by Attr as it
124 // visits all the various parts of the trees during attribution.
125 private Lint lint;
126
127 // The method being analyzed in Attr - it is set/reset as needed by
128 // Attr as it visits new method declarations.
129 private MethodSymbol method;
130
131 public static Check instance(Context context) {
132 Check instance = context.get(checkKey);
133 if (instance == null)
134 instance = new Check(context);
135 return instance;
136 }
137
138 @SuppressWarnings("this-escape")
139 protected Check(Context context) {
140 context.put(checkKey, this);
141
142 names = Names.instance(context);
143 log = Log.instance(context);
144 rs = Resolve.instance(context);
145 syms = Symtab.instance(context);
146 enter = Enter.instance(context);
147 deferredAttr = DeferredAttr.instance(context);
148 infer = Infer.instance(context);
149 types = Types.instance(context);
150 typeAnnotations = TypeAnnotations.instance(context);
151 diags = JCDiagnostic.Factory.instance(context);
152 Options options = Options.instance(context);
153 lint = Lint.instance(context);
154 fileManager = context.get(JavaFileManager.class);
155
156 source = Source.instance(context);
157 target = Target.instance(context);
158 warnOnAnyAccessToMembers = options.isSet("warnOnAccessToMembers");
159
160 disablePreviewCheck = false;
161
162 Target target = Target.instance(context);
163 syntheticNameChar = target.syntheticNameChar();
164
165 profile = Profile.instance(context);
166 preview = Preview.instance(context);
167
168 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
169 boolean verboseRemoval = lint.isEnabled(LintCategory.REMOVAL);
170 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
171 boolean enforceMandatoryWarnings = true;
172
173 deprecationHandler = new MandatoryWarningHandler(log, null, verboseDeprecated,
174 enforceMandatoryWarnings, "deprecated", LintCategory.DEPRECATION);
175 removalHandler = new MandatoryWarningHandler(log, null, verboseRemoval,
176 enforceMandatoryWarnings, "removal", LintCategory.REMOVAL);
177 uncheckedHandler = new MandatoryWarningHandler(log, null, verboseUnchecked,
178 enforceMandatoryWarnings, "unchecked", LintCategory.UNCHECKED);
179 sunApiHandler = new MandatoryWarningHandler(log, null, false,
180 enforceMandatoryWarnings, "sunapi", null);
181
182 deferredLintHandler = DeferredLintHandler.instance(context);
183
184 allowModules = Feature.MODULES.allowedInSource(source);
185 allowRecords = Feature.RECORDS.allowedInSource(source);
186 allowSealed = Feature.SEALED_CLASSES.allowedInSource(source);
187 }
188
189 /** Character for synthetic names
190 */
191 char syntheticNameChar;
192
193 /** A table mapping flat names of all compiled classes for each module in this run
194 * to their symbols; maintained from outside.
195 */
196 private Map<Pair<ModuleSymbol, Name>,ClassSymbol> compiled = new HashMap<>();
197
198 /** A handler for messages about deprecated usage.
199 */
200 private MandatoryWarningHandler deprecationHandler;
201
202 /** A handler for messages about deprecated-for-removal usage.
203 */
204 private MandatoryWarningHandler removalHandler;
205
206 /** A handler for messages about unchecked or unsafe usage.
207 */
208 private MandatoryWarningHandler uncheckedHandler;
209
210 /** A handler for messages about using proprietary API.
211 */
212 private MandatoryWarningHandler sunApiHandler;
213
214 /** A handler for deferred lint warnings.
215 */
216 private DeferredLintHandler deferredLintHandler;
217
218 /** Are modules allowed
219 */
220 private final boolean allowModules;
221
222 /** Are records allowed
223 */
224 private final boolean allowRecords;
225
226 /** Are sealed classes allowed
227 */
228 private final boolean allowSealed;
229
230 /* *************************************************************************
231 * Errors and Warnings
232 **************************************************************************/
233
234 Lint setLint(Lint newLint) {
235 Lint prev = lint;
236 lint = newLint;
237 return prev;
238 }
239
240 MethodSymbol setMethod(MethodSymbol newMethod) {
241 MethodSymbol prev = method;
242 method = newMethod;
243 return prev;
244 }
245
246 /** Warn about deprecated symbol.
247 * @param pos Position to be used for error reporting.
248 * @param sym The deprecated symbol.
249 */
250 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
251 if (sym.isDeprecatedForRemoval()) {
252 if (!lint.isSuppressed(LintCategory.REMOVAL)) {
253 if (sym.kind == MDL) {
254 removalHandler.report(pos, Warnings.HasBeenDeprecatedForRemovalModule(sym));
255 } else {
256 removalHandler.report(pos, Warnings.HasBeenDeprecatedForRemoval(sym, sym.location()));
257 }
258 }
259 } else if (!lint.isSuppressed(LintCategory.DEPRECATION)) {
260 if (sym.kind == MDL) {
261 deprecationHandler.report(pos, Warnings.HasBeenDeprecatedModule(sym));
262 } else {
263 deprecationHandler.report(pos, Warnings.HasBeenDeprecated(sym, sym.location()));
264 }
265 }
266 }
267
268 /** Log a preview warning.
269 * @param pos Position to be used for error reporting.
270 * @param msg A Warning describing the problem.
271 */
272 public void warnPreviewAPI(DiagnosticPosition pos, Warning warnKey) {
273 if (!lint.isSuppressed(LintCategory.PREVIEW))
274 preview.reportPreviewWarning(pos, warnKey);
275 }
276
277 /** Log a preview warning.
278 * @param pos Position to be used for error reporting.
279 * @param msg A Warning describing the problem.
280 */
281 public void warnDeclaredUsingPreview(DiagnosticPosition pos, Symbol sym) {
282 if (!lint.isSuppressed(LintCategory.PREVIEW))
283 preview.reportPreviewWarning(pos, Warnings.DeclaredUsingPreview(kindName(sym), sym));
284 }
285
286 /** Log a preview warning.
287 * @param pos Position to be used for error reporting.
288 * @param msg A Warning describing the problem.
289 */
290 public void warnRestrictedAPI(DiagnosticPosition pos, Symbol sym) {
291 if (lint.isEnabled(LintCategory.RESTRICTED))
292 log.warning(LintCategory.RESTRICTED, pos, Warnings.RestrictedMethod(sym.enclClass(), sym));
293 }
294
295 /** Warn about unchecked operation.
296 * @param pos Position to be used for error reporting.
297 * @param msg A string describing the problem.
298 */
299 public void warnUnchecked(DiagnosticPosition pos, Warning warnKey) {
300 if (!lint.isSuppressed(LintCategory.UNCHECKED))
301 uncheckedHandler.report(pos, warnKey);
302 }
303
304 /** Warn about unsafe vararg method decl.
305 * @param pos Position to be used for error reporting.
306 */
307 void warnUnsafeVararg(DiagnosticPosition pos, Warning warnKey) {
308 if (lint.isEnabled(LintCategory.VARARGS))
309 log.warning(LintCategory.VARARGS, pos, warnKey);
310 }
311
312 public void warnStatic(DiagnosticPosition pos, Warning warnKey) {
313 if (lint.isEnabled(LintCategory.STATIC))
314 log.warning(LintCategory.STATIC, pos, warnKey);
315 }
316
317 /** Warn about division by integer constant zero.
318 * @param pos Position to be used for error reporting.
319 */
320 void warnDivZero(DiagnosticPosition pos) {
321 if (lint.isEnabled(LintCategory.DIVZERO))
322 log.warning(LintCategory.DIVZERO, pos, Warnings.DivZero);
323 }
324
325 /**
326 * Report any deferred diagnostics.
327 */
328 public void reportDeferredDiagnostics() {
329 deprecationHandler.reportDeferredDiagnostic();
330 removalHandler.reportDeferredDiagnostic();
331 uncheckedHandler.reportDeferredDiagnostic();
332 sunApiHandler.reportDeferredDiagnostic();
333 }
334
335
336 /** Report a failure to complete a class.
337 * @param pos Position to be used for error reporting.
338 * @param ex The failure to report.
339 */
340 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
341 log.error(JCDiagnostic.DiagnosticFlag.NON_DEFERRABLE, pos, Errors.CantAccess(ex.sym, ex.getDetailValue()));
342 return syms.errType;
343 }
344
345 /** Report an error that wrong type tag was found.
346 * @param pos Position to be used for error reporting.
347 * @param required An internationalized string describing the type tag
348 * required.
349 * @param found The type that was found.
350 */
351 Type typeTagError(DiagnosticPosition pos, JCDiagnostic required, Object found) {
352 // this error used to be raised by the parser,
353 // but has been delayed to this point:
354 if (found instanceof Type type && type.hasTag(VOID)) {
355 log.error(pos, Errors.IllegalStartOfType);
356 return syms.errType;
357 }
358 log.error(pos, Errors.TypeFoundReq(found, required));
359 return types.createErrorType(found instanceof Type type ? type : syms.errType);
360 }
361
362 /** Report duplicate declaration error.
363 */
364 void duplicateError(DiagnosticPosition pos, Symbol sym) {
365 if (!sym.type.isErroneous()) {
366 Symbol location = sym.location();
367 if (location.kind == MTH &&
368 ((MethodSymbol)location).isStaticOrInstanceInit()) {
369 log.error(pos,
370 Errors.AlreadyDefinedInClinit(kindName(sym),
371 sym,
372 kindName(sym.location()),
373 kindName(sym.location().enclClass()),
374 sym.location().enclClass()));
375 } else {
376 /* dont error if this is a duplicated parameter of a generated canonical constructor
377 * as we should have issued an error for the duplicated fields
378 */
379 if (location.kind != MTH ||
380 ((sym.owner.flags_field & GENERATEDCONSTR) == 0) ||
381 ((sym.owner.flags_field & RECORD) == 0)) {
382 log.error(pos,
383 Errors.AlreadyDefined(kindName(sym),
384 sym,
385 kindName(sym.location()),
386 sym.location()));
387 }
388 }
389 }
390 }
391
392 /** Report array/varargs duplicate declaration
393 */
394 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
395 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
396 log.error(pos, Errors.ArrayAndVarargs(sym1, sym2, sym2.location()));
397 }
398 }
399
400 /* ************************************************************************
401 * duplicate declaration checking
402 *************************************************************************/
403
404 /** Check that variable does not hide variable with same name in
405 * immediately enclosing local scope.
406 * @param pos Position for error reporting.
407 * @param v The symbol.
408 * @param s The scope.
409 */
410 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
411 for (Symbol sym : s.getSymbolsByName(v.name)) {
412 if (sym.owner != v.owner) break;
413 if (sym.kind == VAR &&
414 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
415 v.name != names.error) {
416 duplicateError(pos, sym);
417 return;
418 }
419 }
420 }
421
422 /** Check that a class or interface does not hide a class or
423 * interface with same name in immediately enclosing local scope.
424 * @param pos Position for error reporting.
425 * @param c The symbol.
426 * @param s The scope.
427 */
428 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
429 for (Symbol sym : s.getSymbolsByName(c.name)) {
430 if (sym.owner != c.owner) break;
431 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR) &&
432 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
433 c.name != names.error) {
434 duplicateError(pos, sym);
435 return;
436 }
437 }
438 }
439
440 /** Check that class does not have the same name as one of
441 * its enclosing classes, or as a class defined in its enclosing scope.
442 * return true if class is unique in its enclosing scope.
443 * @param pos Position for error reporting.
444 * @param name The class name.
445 * @param s The enclosing scope.
446 */
447 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
448 for (Symbol sym : s.getSymbolsByName(name, NON_RECURSIVE)) {
449 if (sym.kind == TYP && sym.name != names.error) {
450 duplicateError(pos, sym);
451 return false;
452 }
453 }
454 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
455 if (sym.kind == TYP && sym.name == name && sym.name != names.error &&
456 !sym.isImplicit()) {
457 duplicateError(pos, sym);
458 return true;
459 }
460 }
461 return true;
462 }
463
464 /* *************************************************************************
465 * Class name generation
466 **************************************************************************/
467
468
469 private Map<Pair<Name, Name>, Integer> localClassNameIndexes = new HashMap<>();
470
471 /** Return name of local class.
472 * This is of the form {@code <enclClass> $ n <classname> }
473 * where
474 * enclClass is the flat name of the enclosing class,
475 * classname is the simple name of the local class
476 */
477 public Name localClassName(ClassSymbol c) {
478 Name enclFlatname = c.owner.enclClass().flatname;
479 String enclFlatnameStr = enclFlatname.toString();
480 Pair<Name, Name> key = new Pair<>(enclFlatname, c.name);
481 Integer index = localClassNameIndexes.get(key);
482 for (int i = (index == null) ? 1 : index; ; i++) {
483 Name flatname = names.fromString(enclFlatnameStr
484 + syntheticNameChar + i + c.name);
485 if (getCompiled(c.packge().modle, flatname) == null) {
486 localClassNameIndexes.put(key, i + 1);
487 return flatname;
488 }
489 }
490 }
491
492 public void clearLocalClassNameIndexes(ClassSymbol c) {
493 if (c.owner != null && c.owner.kind != NIL) {
494 localClassNameIndexes.remove(new Pair<>(
495 c.owner.enclClass().flatname, c.name));
496 }
497 }
498
499 public void newRound() {
500 compiled.clear();
501 localClassNameIndexes.clear();
502 }
503
504 public void clear() {
505 deprecationHandler.clear();
506 removalHandler.clear();
507 uncheckedHandler.clear();
508 sunApiHandler.clear();
509 }
510
511 public void putCompiled(ClassSymbol csym) {
512 compiled.put(Pair.of(csym.packge().modle, csym.flatname), csym);
513 }
514
515 public ClassSymbol getCompiled(ClassSymbol csym) {
516 return compiled.get(Pair.of(csym.packge().modle, csym.flatname));
517 }
518
519 public ClassSymbol getCompiled(ModuleSymbol msym, Name flatname) {
520 return compiled.get(Pair.of(msym, flatname));
521 }
522
523 public void removeCompiled(ClassSymbol csym) {
524 compiled.remove(Pair.of(csym.packge().modle, csym.flatname));
525 }
526
527 /* *************************************************************************
528 * Type Checking
529 **************************************************************************/
530
531 /**
532 * A check context is an object that can be used to perform compatibility
533 * checks - depending on the check context, meaning of 'compatibility' might
534 * vary significantly.
535 */
536 public interface CheckContext {
537 /**
538 * Is type 'found' compatible with type 'req' in given context
539 */
540 boolean compatible(Type found, Type req, Warner warn);
541 /**
542 * Report a check error
543 */
544 void report(DiagnosticPosition pos, JCDiagnostic details);
545 /**
546 * Obtain a warner for this check context
547 */
548 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req);
549
550 public InferenceContext inferenceContext();
551
552 public DeferredAttr.DeferredAttrContext deferredAttrContext();
553 }
554
555 /**
556 * This class represent a check context that is nested within another check
557 * context - useful to check sub-expressions. The default behavior simply
558 * redirects all method calls to the enclosing check context leveraging
559 * the forwarding pattern.
560 */
561 static class NestedCheckContext implements CheckContext {
562 CheckContext enclosingContext;
563
564 NestedCheckContext(CheckContext enclosingContext) {
565 this.enclosingContext = enclosingContext;
566 }
567
568 public boolean compatible(Type found, Type req, Warner warn) {
569 return enclosingContext.compatible(found, req, warn);
570 }
571
572 public void report(DiagnosticPosition pos, JCDiagnostic details) {
573 enclosingContext.report(pos, details);
574 }
575
576 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
577 return enclosingContext.checkWarner(pos, found, req);
578 }
579
580 public InferenceContext inferenceContext() {
581 return enclosingContext.inferenceContext();
582 }
583
584 public DeferredAttrContext deferredAttrContext() {
585 return enclosingContext.deferredAttrContext();
586 }
587 }
588
589 /**
590 * Check context to be used when evaluating assignment/return statements
591 */
592 CheckContext basicHandler = new CheckContext() {
593 public void report(DiagnosticPosition pos, JCDiagnostic details) {
594 log.error(pos, Errors.ProbFoundReq(details));
595 }
596 public boolean compatible(Type found, Type req, Warner warn) {
597 return types.isAssignable(found, req, warn);
598 }
599
600 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
601 return convertWarner(pos, found, req);
602 }
603
604 public InferenceContext inferenceContext() {
605 return infer.emptyContext;
606 }
607
608 public DeferredAttrContext deferredAttrContext() {
609 return deferredAttr.emptyDeferredAttrContext;
610 }
611
612 @Override
613 public String toString() {
614 return "CheckContext: basicHandler";
615 }
616 };
617
618 /** Check that a given type is assignable to a given proto-type.
619 * If it is, return the type, otherwise return errType.
620 * @param pos Position to be used for error reporting.
621 * @param found The type that was found.
622 * @param req The type that was required.
623 */
624 public Type checkType(DiagnosticPosition pos, Type found, Type req) {
625 return checkType(pos, found, req, basicHandler);
626 }
627
628 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) {
629 final InferenceContext inferenceContext = checkContext.inferenceContext();
630 if (inferenceContext.free(req) || inferenceContext.free(found)) {
631 inferenceContext.addFreeTypeListener(List.of(req, found),
632 solvedContext -> checkType(pos, solvedContext.asInstType(found), solvedContext.asInstType(req), checkContext));
633 }
634 if (req.hasTag(ERROR))
635 return req;
636 if (req.hasTag(NONE))
637 return found;
638 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) {
639 return found;
640 } else {
641 if (found.isNumeric() && req.isNumeric()) {
642 checkContext.report(pos, diags.fragment(Fragments.PossibleLossOfPrecision(found, req)));
643 return types.createErrorType(found);
644 }
645 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
646 return types.createErrorType(found);
647 }
648 }
649
650 /** Check that a given type can be cast to a given target type.
651 * Return the result of the cast.
652 * @param pos Position to be used for error reporting.
653 * @param found The type that is being cast.
654 * @param req The target type of the cast.
655 */
656 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
657 return checkCastable(pos, found, req, basicHandler);
658 }
659 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) {
660 if (types.isCastable(found, req, castWarner(pos, found, req))) {
661 return req;
662 } else {
663 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
664 return types.createErrorType(found);
665 }
666 }
667
668 /** Check for redundant casts (i.e. where source type is a subtype of target type)
669 * The problem should only be reported for non-292 cast
670 */
671 public void checkRedundantCast(Env<AttrContext> env, final JCTypeCast tree) {
672 if (!tree.type.isErroneous()
673 && types.isSameType(tree.expr.type, tree.clazz.type)
674 && !(ignoreAnnotatedCasts && TreeInfo.containsTypeAnnotation(tree.clazz))
675 && !is292targetTypeCast(tree)) {
676 deferredLintHandler.report(() -> {
677 if (lint.isEnabled(LintCategory.CAST))
678 log.warning(LintCategory.CAST,
679 tree.pos(), Warnings.RedundantCast(tree.clazz.type));
680 });
681 }
682 }
683 //where
684 private boolean is292targetTypeCast(JCTypeCast tree) {
685 boolean is292targetTypeCast = false;
686 JCExpression expr = TreeInfo.skipParens(tree.expr);
687 if (expr.hasTag(APPLY)) {
688 JCMethodInvocation apply = (JCMethodInvocation)expr;
689 Symbol sym = TreeInfo.symbol(apply.meth);
690 is292targetTypeCast = sym != null &&
691 sym.kind == MTH &&
692 (sym.flags() & HYPOTHETICAL) != 0;
693 }
694 return is292targetTypeCast;
695 }
696
697 private static final boolean ignoreAnnotatedCasts = true;
698
699 /** Check that a type is within some bounds.
700 *
701 * Used in TypeApply to verify that, e.g., X in {@code V<X>} is a valid
702 * type argument.
703 * @param a The type that should be bounded by bs.
704 * @param bound The bound.
705 */
706 private boolean checkExtends(Type a, Type bound) {
707 if (a.isUnbound()) {
708 return true;
709 } else if (!a.hasTag(WILDCARD)) {
710 a = types.cvarUpperBound(a);
711 return types.isSubtype(a, bound);
712 } else if (a.isExtendsBound()) {
713 return types.isCastable(bound, types.wildUpperBound(a), types.noWarnings);
714 } else if (a.isSuperBound()) {
715 return !types.notSoftSubtype(types.wildLowerBound(a), bound);
716 }
717 return true;
718 }
719
720 /** Check that type is different from 'void'.
721 * @param pos Position to be used for error reporting.
722 * @param t The type to be checked.
723 */
724 Type checkNonVoid(DiagnosticPosition pos, Type t) {
725 if (t.hasTag(VOID)) {
726 log.error(pos, Errors.VoidNotAllowedHere);
727 return types.createErrorType(t);
728 } else {
729 return t;
730 }
731 }
732
733 Type checkClassOrArrayType(DiagnosticPosition pos, Type t) {
734 if (!t.hasTag(CLASS) && !t.hasTag(ARRAY) && !t.hasTag(ERROR)) {
735 return typeTagError(pos,
736 diags.fragment(Fragments.TypeReqClassArray),
737 asTypeParam(t));
738 } else {
739 return t;
740 }
741 }
742
743 /** Check that type is a class or interface type.
744 * @param pos Position to be used for error reporting.
745 * @param t The type to be checked.
746 */
747 Type checkClassType(DiagnosticPosition pos, Type t) {
748 if (!t.hasTag(CLASS) && !t.hasTag(ERROR)) {
749 return typeTagError(pos,
750 diags.fragment(Fragments.TypeReqClass),
751 asTypeParam(t));
752 } else {
753 return t;
754 }
755 }
756 //where
757 private Object asTypeParam(Type t) {
758 return (t.hasTag(TYPEVAR))
759 ? diags.fragment(Fragments.TypeParameter(t))
760 : t;
761 }
762
763 void checkConstraintsOfValueClass(JCClassDecl tree, ClassSymbol c) {
764 DiagnosticPosition pos = tree.pos();
765 for (Type st : types.closure(c.type)) {
766 if (st == null || st.tsym == null || st.tsym.kind == ERR)
767 continue;
768 if (st.tsym == syms.objectType.tsym || st.tsym == syms.recordType.tsym || st.isInterface())
769 continue;
770 if (!st.tsym.isAbstract()) {
771 if (c != st.tsym) {
772 log.error(pos, Errors.ConcreteSupertypeForValueClass(c, st));
773 }
774 continue;
775 }
776 // dealing with an abstract value or value super class below.
777 for (Symbol s : st.tsym.members().getSymbols(NON_RECURSIVE)) {
778 if (s.kind == MTH) {
779 if ((s.flags() & (SYNCHRONIZED | STATIC)) == SYNCHRONIZED) {
780 log.error(pos, Errors.SuperClassMethodCannotBeSynchronized(s, c, st));
781 }
782 break;
783 }
784 }
785 }
786 }
787
788 /** Check that type is a valid qualifier for a constructor reference expression
789 */
790 Type checkConstructorRefType(DiagnosticPosition pos, Type t) {
791 t = checkClassOrArrayType(pos, t);
792 if (t.hasTag(CLASS)) {
793 if ((t.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
794 log.error(pos, Errors.AbstractCantBeInstantiated(t.tsym));
795 t = types.createErrorType(t);
796 } else if ((t.tsym.flags() & ENUM) != 0) {
797 log.error(pos, Errors.EnumCantBeInstantiated);
798 t = types.createErrorType(t);
799 } else {
800 t = checkClassType(pos, t, true);
801 }
802 } else if (t.hasTag(ARRAY)) {
803 if (!types.isReifiable(((ArrayType)t).elemtype)) {
804 log.error(pos, Errors.GenericArrayCreation);
805 t = types.createErrorType(t);
806 }
807 }
808 return t;
809 }
810
811 /** Check that type is a class or interface type.
812 * @param pos Position to be used for error reporting.
813 * @param t The type to be checked.
814 * @param noBounds True if type bounds are illegal here.
815 */
816 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
817 t = checkClassType(pos, t);
818 if (noBounds && t.isParameterized()) {
819 List<Type> args = t.getTypeArguments();
820 while (args.nonEmpty()) {
821 if (args.head.hasTag(WILDCARD))
822 return typeTagError(pos,
823 diags.fragment(Fragments.TypeReqExact),
824 args.head);
825 args = args.tail;
826 }
827 }
828 return t;
829 }
830
831 /** Check that type is a reference type, i.e. a class, interface or array type
832 * or a type variable.
833 * @param pos Position to be used for error reporting.
834 * @param t The type to be checked.
835 */
836 Type checkRefType(DiagnosticPosition pos, Type t) {
837 if (t.isReference())
838 return t;
839 else
840 return typeTagError(pos,
841 diags.fragment(Fragments.TypeReqRef),
842 t);
843 }
844
845 /** Check that type is an identity type, i.e. not a value type.
846 * When not discernible statically, give it the benefit of doubt
847 * and defer to runtime.
848 *
849 * @param pos Position to be used for error reporting.
850 * @param t The type to be checked.
851 */
852 void checkIdentityType(DiagnosticPosition pos, Type t) {
853 if (t.hasTag(TYPEVAR)) {
854 t = types.skipTypeVars(t, false);
855 }
856 if (t.isIntersection()) {
857 IntersectionClassType ict = (IntersectionClassType)t;
858 for (Type component : ict.getExplicitComponents()) {
859 checkIdentityType(pos, component);
860 }
861 return;
862 }
863 if (t.isPrimitive() || (t.isValueClass() && !t.tsym.isAbstract()))
864 typeTagError(pos, diags.fragment(Fragments.TypeReqIdentity), t);
865 }
866
867 /** Check that each type is a reference type, i.e. a class, interface or array type
868 * or a type variable.
869 * @param trees Original trees, used for error reporting.
870 * @param types The types to be checked.
871 */
872 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
873 List<JCExpression> tl = trees;
874 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
875 l.head = checkRefType(tl.head.pos(), l.head);
876 tl = tl.tail;
877 }
878 return types;
879 }
880
881 /** Check that type is a null or reference type.
882 * @param pos Position to be used for error reporting.
883 * @param t The type to be checked.
884 */
885 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
886 if (t.isReference() || t.hasTag(BOT))
887 return t;
888 else
889 return typeTagError(pos,
890 diags.fragment(Fragments.TypeReqRef),
891 t);
892 }
893
894 /** Check that flag set does not contain elements of two conflicting sets. s
895 * Return true if it doesn't.
896 * @param pos Position to be used for error reporting.
897 * @param flags The set of flags to be checked.
898 * @param set1 Conflicting flags set #1.
899 * @param set2 Conflicting flags set #2.
900 */
901 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
902 if ((flags & set1) != 0 && (flags & set2) != 0) {
903 log.error(pos,
904 Errors.IllegalCombinationOfModifiers(asFlagSet(TreeInfo.firstFlag(flags & set1)),
905 asFlagSet(TreeInfo.firstFlag(flags & set2))));
906 return false;
907 } else
908 return true;
909 }
910
911 /** Check that usage of diamond operator is correct (i.e. diamond should not
912 * be used with non-generic classes or in anonymous class creation expressions)
913 */
914 Type checkDiamond(JCNewClass tree, Type t) {
915 if (!TreeInfo.isDiamond(tree) ||
916 t.isErroneous()) {
917 return checkClassType(tree.clazz.pos(), t, true);
918 } else {
919 if (tree.def != null && !Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.allowedInSource(source)) {
920 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.clazz.pos(),
921 Errors.CantApplyDiamond1(t, Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.fragment(source.name)));
922 }
923 if (t.tsym.type.getTypeArguments().isEmpty()) {
924 log.error(tree.clazz.pos(),
925 Errors.CantApplyDiamond1(t,
926 Fragments.DiamondNonGeneric(t)));
927 return types.createErrorType(t);
928 } else if (tree.typeargs != null &&
929 tree.typeargs.nonEmpty()) {
930 log.error(tree.clazz.pos(),
931 Errors.CantApplyDiamond1(t,
932 Fragments.DiamondAndExplicitParams(t)));
933 return types.createErrorType(t);
934 } else {
935 return t;
936 }
937 }
938 }
939
940 /** Check that the type inferred using the diamond operator does not contain
941 * non-denotable types such as captured types or intersection types.
942 * @param t the type inferred using the diamond operator
943 * @return the (possibly empty) list of non-denotable types.
944 */
945 List<Type> checkDiamondDenotable(ClassType t) {
946 ListBuffer<Type> buf = new ListBuffer<>();
947 for (Type arg : t.allparams()) {
948 if (!checkDenotable(arg)) {
949 buf.append(arg);
950 }
951 }
952 return buf.toList();
953 }
954
955 public boolean checkDenotable(Type t) {
956 return denotableChecker.visit(t, null);
957 }
958 // where
959
960 /** diamondTypeChecker: A type visitor that descends down the given type looking for non-denotable
961 * types. The visit methods return false as soon as a non-denotable type is encountered and true
962 * otherwise.
963 */
964 private static final Types.SimpleVisitor<Boolean, Void> denotableChecker = new Types.SimpleVisitor<Boolean, Void>() {
965 @Override
966 public Boolean visitType(Type t, Void s) {
967 return true;
968 }
969 @Override
970 public Boolean visitClassType(ClassType t, Void s) {
971 if (t.isUnion() || t.isIntersection()) {
972 return false;
973 }
974 for (Type targ : t.allparams()) {
975 if (!visit(targ, s)) {
976 return false;
977 }
978 }
979 return true;
980 }
981
982 @Override
983 public Boolean visitTypeVar(TypeVar t, Void s) {
984 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
985 (i.e cannot have been produced by inference (18.4))
986 */
987 return (t.tsym.flags() & SYNTHETIC) == 0;
988 }
989
990 @Override
991 public Boolean visitCapturedType(CapturedType t, Void s) {
992 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
993 (i.e cannot have been produced by capture conversion (5.1.10))
994 */
995 return false;
996 }
997
998 @Override
999 public Boolean visitArrayType(ArrayType t, Void s) {
1000 return visit(t.elemtype, s);
1001 }
1002
1003 @Override
1004 public Boolean visitWildcardType(WildcardType t, Void s) {
1005 return visit(t.type, s);
1006 }
1007 };
1008
1009 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
1010 MethodSymbol m = tree.sym;
1011 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
1012 Type varargElemType = null;
1013 if (m.isVarArgs()) {
1014 varargElemType = types.elemtype(tree.params.last().type);
1015 }
1016 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
1017 if (varargElemType != null) {
1018 JCDiagnostic msg = Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ?
1019 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargs(m)) :
1020 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargsFinalOnly(m));
1021 log.error(tree,
1022 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
1023 msg));
1024 } else {
1025 log.error(tree,
1026 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
1027 Fragments.VarargsTrustmeOnNonVarargsMeth(m)));
1028 }
1029 } else if (hasTrustMeAnno && varargElemType != null &&
1030 types.isReifiable(varargElemType)) {
1031 warnUnsafeVararg(tree, Warnings.VarargsRedundantTrustmeAnno(
1032 syms.trustMeType.tsym,
1033 diags.fragment(Fragments.VarargsTrustmeOnReifiableVarargs(varargElemType))));
1034 }
1035 else if (!hasTrustMeAnno && varargElemType != null &&
1036 !types.isReifiable(varargElemType)) {
1037 warnUnchecked(tree.params.head.pos(), Warnings.UncheckedVarargsNonReifiableType(varargElemType));
1038 }
1039 }
1040 //where
1041 private boolean isTrustMeAllowedOnMethod(Symbol s) {
1042 return (s.flags() & VARARGS) != 0 &&
1043 (s.isConstructor() ||
1044 (s.flags() & (STATIC | FINAL |
1045 (Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ? PRIVATE : 0) )) != 0);
1046 }
1047
1048 Type checkLocalVarType(DiagnosticPosition pos, Type t, Name name) {
1049 //check that resulting type is not the null type
1050 if (t.hasTag(BOT)) {
1051 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferNull));
1052 return types.createErrorType(t);
1053 } else if (t.hasTag(VOID)) {
1054 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferVoid));
1055 return types.createErrorType(t);
1056 }
1057
1058 //upward project the initializer type
1059 return types.upward(t, types.captures(t)).baseType();
1060 }
1061
1062 Type checkMethod(final Type mtype,
1063 final Symbol sym,
1064 final Env<AttrContext> env,
1065 final List<JCExpression> argtrees,
1066 final List<Type> argtypes,
1067 final boolean useVarargs,
1068 InferenceContext inferenceContext) {
1069 // System.out.println("call : " + env.tree);
1070 // System.out.println("method : " + owntype);
1071 // System.out.println("actuals: " + argtypes);
1072 if (inferenceContext.free(mtype)) {
1073 inferenceContext.addFreeTypeListener(List.of(mtype),
1074 solvedContext -> checkMethod(solvedContext.asInstType(mtype), sym, env, argtrees, argtypes, useVarargs, solvedContext));
1075 return mtype;
1076 }
1077 Type owntype = mtype;
1078 List<Type> formals = owntype.getParameterTypes();
1079 List<Type> nonInferred = sym.type.getParameterTypes();
1080 if (nonInferred.length() != formals.length()) nonInferred = formals;
1081 Type last = useVarargs ? formals.last() : null;
1082 if (sym.name == names.init && sym.owner == syms.enumSym) {
1083 formals = formals.tail.tail;
1084 nonInferred = nonInferred.tail.tail;
1085 }
1086 if ((sym.flags() & ANONCONSTR_BASED) != 0) {
1087 formals = formals.tail;
1088 nonInferred = nonInferred.tail;
1089 }
1090 List<JCExpression> args = argtrees;
1091 if (args != null) {
1092 //this is null when type-checking a method reference
1093 while (formals.head != last) {
1094 JCTree arg = args.head;
1095 Warner warn = convertWarner(arg.pos(), arg.type, nonInferred.head);
1096 assertConvertible(arg, arg.type, formals.head, warn);
1097 args = args.tail;
1098 formals = formals.tail;
1099 nonInferred = nonInferred.tail;
1100 }
1101 if (useVarargs) {
1102 Type varArg = types.elemtype(last);
1103 while (args.tail != null) {
1104 JCTree arg = args.head;
1105 Warner warn = convertWarner(arg.pos(), arg.type, varArg);
1106 assertConvertible(arg, arg.type, varArg, warn);
1107 args = args.tail;
1108 }
1109 } else if ((sym.flags() & (VARARGS | SIGNATURE_POLYMORPHIC)) == VARARGS) {
1110 // non-varargs call to varargs method
1111 Type varParam = owntype.getParameterTypes().last();
1112 Type lastArg = argtypes.last();
1113 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
1114 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
1115 log.warning(argtrees.last().pos(),
1116 Warnings.InexactNonVarargsCall(types.elemtype(varParam),varParam));
1117 }
1118 }
1119 if (useVarargs) {
1120 Type argtype = owntype.getParameterTypes().last();
1121 if (!types.isReifiable(argtype) &&
1122 (sym.baseSymbol().attribute(syms.trustMeType.tsym) == null ||
1123 !isTrustMeAllowedOnMethod(sym))) {
1124 warnUnchecked(env.tree.pos(), Warnings.UncheckedGenericArrayCreation(argtype));
1125 }
1126 TreeInfo.setVarargsElement(env.tree, types.elemtype(argtype));
1127 }
1128 return owntype;
1129 }
1130 //where
1131 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
1132 if (types.isConvertible(actual, formal, warn))
1133 return;
1134
1135 if (formal.isCompound()
1136 && types.isSubtype(actual, types.supertype(formal))
1137 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
1138 return;
1139 }
1140
1141 /**
1142 * Check that type 't' is a valid instantiation of a generic class
1143 * (see JLS 4.5)
1144 *
1145 * @param t class type to be checked
1146 * @return true if 't' is well-formed
1147 */
1148 public boolean checkValidGenericType(Type t) {
1149 return firstIncompatibleTypeArg(t) == null;
1150 }
1151 //WHERE
1152 private Type firstIncompatibleTypeArg(Type type) {
1153 List<Type> formals = type.tsym.type.allparams();
1154 List<Type> actuals = type.allparams();
1155 List<Type> args = type.getTypeArguments();
1156 List<Type> forms = type.tsym.type.getTypeArguments();
1157 ListBuffer<Type> bounds_buf = new ListBuffer<>();
1158
1159 // For matching pairs of actual argument types `a' and
1160 // formal type parameters with declared bound `b' ...
1161 while (args.nonEmpty() && forms.nonEmpty()) {
1162 // exact type arguments needs to know their
1163 // bounds (for upper and lower bound
1164 // calculations). So we create new bounds where
1165 // type-parameters are replaced with actuals argument types.
1166 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals));
1167 args = args.tail;
1168 forms = forms.tail;
1169 }
1170
1171 args = type.getTypeArguments();
1172 List<Type> tvars_cap = types.substBounds(formals,
1173 formals,
1174 types.capture(type).allparams());
1175 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
1176 // Let the actual arguments know their bound
1177 args.head.withTypeVar((TypeVar)tvars_cap.head);
1178 args = args.tail;
1179 tvars_cap = tvars_cap.tail;
1180 }
1181
1182 args = type.getTypeArguments();
1183 List<Type> bounds = bounds_buf.toList();
1184
1185 while (args.nonEmpty() && bounds.nonEmpty()) {
1186 Type actual = args.head;
1187 if (!isTypeArgErroneous(actual) &&
1188 !bounds.head.isErroneous() &&
1189 !checkExtends(actual, bounds.head)) {
1190 return args.head;
1191 }
1192 args = args.tail;
1193 bounds = bounds.tail;
1194 }
1195
1196 args = type.getTypeArguments();
1197 bounds = bounds_buf.toList();
1198
1199 for (Type arg : types.capture(type).getTypeArguments()) {
1200 if (arg.hasTag(TYPEVAR) &&
1201 arg.getUpperBound().isErroneous() &&
1202 !bounds.head.isErroneous() &&
1203 !isTypeArgErroneous(args.head)) {
1204 return args.head;
1205 }
1206 bounds = bounds.tail;
1207 args = args.tail;
1208 }
1209
1210 return null;
1211 }
1212 //where
1213 boolean isTypeArgErroneous(Type t) {
1214 return isTypeArgErroneous.visit(t);
1215 }
1216
1217 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
1218 public Boolean visitType(Type t, Void s) {
1219 return t.isErroneous();
1220 }
1221 @Override
1222 public Boolean visitTypeVar(TypeVar t, Void s) {
1223 return visit(t.getUpperBound());
1224 }
1225 @Override
1226 public Boolean visitCapturedType(CapturedType t, Void s) {
1227 return visit(t.getUpperBound()) ||
1228 visit(t.getLowerBound());
1229 }
1230 @Override
1231 public Boolean visitWildcardType(WildcardType t, Void s) {
1232 return visit(t.type);
1233 }
1234 };
1235
1236 /** Check that given modifiers are legal for given symbol and
1237 * return modifiers together with any implicit modifiers for that symbol.
1238 * Warning: we can't use flags() here since this method
1239 * is called during class enter, when flags() would cause a premature
1240 * completion.
1241 * @param pos Position to be used for error reporting.
1242 * @param flags The set of modifiers given in a definition.
1243 * @param sym The defined symbol.
1244 */
1245 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
1246 long mask;
1247 long implicit = 0;
1248
1249 switch (sym.kind) {
1250 case VAR:
1251 if (TreeInfo.isReceiverParam(tree))
1252 mask = ReceiverParamFlags;
1253 else if (sym.owner.kind != TYP)
1254 mask = LocalVarFlags;
1255 else if ((sym.owner.flags_field & INTERFACE) != 0)
1256 mask = implicit = InterfaceVarFlags;
1257 else {
1258 boolean isInstanceFieldOfValueClass = sym.owner.type.isValueClass() && (flags & STATIC) == 0;
1259 mask = !isInstanceFieldOfValueClass ? VarFlags : ExtendedVarFlags;
1260 if (isInstanceFieldOfValueClass) {
1261 implicit |= FINAL | STRICT;
1262 }
1263 }
1264 break;
1265 case MTH:
1266 if (sym.name == names.init) {
1267 if ((sym.owner.flags_field & ENUM) != 0) {
1268 // enum constructors cannot be declared public or
1269 // protected and must be implicitly or explicitly
1270 // private
1271 implicit = PRIVATE;
1272 mask = PRIVATE;
1273 } else
1274 mask = ConstructorFlags;
1275 } else if ((sym.owner.flags_field & INTERFACE) != 0) {
1276 if ((sym.owner.flags_field & ANNOTATION) != 0) {
1277 mask = AnnotationTypeElementMask;
1278 implicit = PUBLIC | ABSTRACT;
1279 } else if ((flags & (DEFAULT | STATIC | PRIVATE)) != 0) {
1280 mask = InterfaceMethodMask;
1281 implicit = (flags & PRIVATE) != 0 ? 0 : PUBLIC;
1282 if ((flags & DEFAULT) != 0) {
1283 implicit |= ABSTRACT;
1284 }
1285 } else {
1286 mask = implicit = InterfaceMethodFlags;
1287 }
1288 } else if ((sym.owner.flags_field & RECORD) != 0) {
1289 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ?
1290 RecordMethodFlags & ~SYNCHRONIZED : RecordMethodFlags;
1291 } else {
1292 // value objects do not have an associated monitor/lock
1293 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ?
1294 MethodFlags & ~SYNCHRONIZED : MethodFlags;
1295 }
1296 if ((flags & STRICTFP) != 0) {
1297 warnOnExplicitStrictfp(pos);
1298 }
1299 // Imply STRICTFP if owner has STRICTFP set.
1300 if (((flags|implicit) & Flags.ABSTRACT) == 0 ||
1301 ((flags) & Flags.DEFAULT) != 0)
1302 implicit |= sym.owner.flags_field & STRICTFP;
1303 break;
1304 case TYP:
1305 if (sym.owner.kind.matches(KindSelector.VAL_MTH) ||
1306 (sym.isDirectlyOrIndirectlyLocal() && (flags & ANNOTATION) != 0)) {
1307 boolean implicitlyStatic = !sym.isAnonymous() &&
1308 ((flags & RECORD) != 0 || (flags & ENUM) != 0 || (flags & INTERFACE) != 0);
1309 boolean staticOrImplicitlyStatic = (flags & STATIC) != 0 || implicitlyStatic;
1310 // local statics are allowed only if records are allowed too
1311 mask = staticOrImplicitlyStatic && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedStaticLocalClassFlags : ExtendedLocalClassFlags;
1312 implicit = implicitlyStatic ? STATIC : implicit;
1313 } else if (sym.owner.kind == TYP) {
1314 // statics in inner classes are allowed only if records are allowed too
1315 mask = ((flags & STATIC) != 0) && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedMemberStaticClassFlags : ExtendedMemberClassFlags;
1316 if (sym.owner.owner.kind == PCK ||
1317 (sym.owner.flags_field & STATIC) != 0) {
1318 mask |= STATIC;
1319 } else if (!allowRecords && ((flags & ENUM) != 0 || (flags & RECORD) != 0)) {
1320 log.error(pos, Errors.StaticDeclarationNotAllowedInInnerClasses);
1321 }
1322 // Nested interfaces and enums are always STATIC (Spec ???)
1323 if ((flags & (INTERFACE | ENUM | RECORD)) != 0 ) implicit = STATIC;
1324 } else {
1325 mask = ExtendedClassFlags;
1326 }
1327 // Interfaces are always ABSTRACT
1328 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
1329
1330 if ((flags & (INTERFACE | VALUE_CLASS)) == 0) {
1331 implicit |= IDENTITY_TYPE;
1332 }
1333
1334 if ((flags & ENUM) != 0) {
1335 // enums can't be declared abstract, final, sealed or non-sealed or value
1336 mask &= ~(ABSTRACT | FINAL | SEALED | NON_SEALED | VALUE_CLASS);
1337 implicit |= implicitEnumFinalFlag(tree);
1338 }
1339 if ((flags & RECORD) != 0) {
1340 // records can't be declared abstract
1341 mask &= ~ABSTRACT;
1342 implicit |= FINAL;
1343 }
1344 if ((flags & STRICTFP) != 0) {
1345 warnOnExplicitStrictfp(pos);
1346 }
1347 // Imply STRICTFP if owner has STRICTFP set.
1348 implicit |= sym.owner.flags_field & STRICTFP;
1349
1350 // concrete value classes are implicitly final
1351 if ((flags & (ABSTRACT | INTERFACE | VALUE_CLASS)) == VALUE_CLASS) {
1352 implicit |= FINAL;
1353 }
1354
1355 // TYPs can't be declared synchronized
1356 mask &= ~SYNCHRONIZED;
1357 break;
1358 default:
1359 throw new AssertionError();
1360 }
1361 long illegal = flags & ExtendedStandardFlags & ~mask;
1362 if (illegal != 0) {
1363 if ((illegal & INTERFACE) != 0) {
1364 log.error(pos, ((flags & ANNOTATION) != 0) ? Errors.AnnotationDeclNotAllowedHere : Errors.IntfNotAllowedHere);
1365 mask |= INTERFACE;
1366 }
1367 else {
1368 log.error(pos,
1369 Errors.ModNotAllowedHere(asFlagSet(illegal)));
1370 }
1371 }
1372 else if ((sym.kind == TYP ||
1373 // ISSUE: Disallowing abstract&private is no longer appropriate
1374 // in the presence of inner classes. Should it be deleted here?
1375 checkDisjoint(pos, flags,
1376 ABSTRACT,
1377 PRIVATE | STATIC | DEFAULT))
1378 &&
1379 checkDisjoint(pos, flags,
1380 STATIC | PRIVATE,
1381 DEFAULT)
1382 &&
1383 checkDisjoint(pos, flags,
1384 ABSTRACT | INTERFACE,
1385 FINAL | NATIVE | SYNCHRONIZED)
1386 &&
1387 checkDisjoint(pos, flags,
1388 INTERFACE,
1389 VALUE_CLASS)
1390 &&
1391 checkDisjoint(pos, flags,
1392 PUBLIC,
1393 PRIVATE | PROTECTED)
1394 &&
1395 checkDisjoint(pos, flags,
1396 PRIVATE,
1397 PUBLIC | PROTECTED)
1398 &&
1399 checkDisjoint(pos, (flags | implicit), // complain against volatile & implcitly final entities too.
1400 FINAL,
1401 VOLATILE)
1402 &&
1403 (sym.kind == TYP ||
1404 checkDisjoint(pos, flags,
1405 ABSTRACT | NATIVE,
1406 STRICTFP))
1407 && checkDisjoint(pos, flags,
1408 FINAL,
1409 SEALED | NON_SEALED)
1410 && checkDisjoint(pos, flags,
1411 SEALED,
1412 FINAL | NON_SEALED)
1413 && checkDisjoint(pos, flags,
1414 SEALED,
1415 ANNOTATION)
1416 && checkDisjoint(pos, flags,
1417 VALUE_CLASS,
1418 ANNOTATION)
1419 && checkDisjoint(pos, flags,
1420 VALUE_CLASS,
1421 NON_SEALED)
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(() -> {
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 (allowRecords && origin.isRecord()) {
2242 // let's find out if this is a user defined accessor in which case the @Override annotation is acceptable
2243 Optional<? extends RecordComponent> recordComponent = origin.getRecordComponents().stream()
2244 .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
2245 if (recordComponent.isPresent()) {
2246 return;
2247 }
2248 }
2249
2250 for (Type t = origin.type; t.hasTag(CLASS);
2251 t = types.supertype(t)) {
2252 if (t != origin.type) {
2253 checkOverride(tree, t, origin, m);
2254 }
2255 for (Type t2 : types.interfaces(t)) {
2256 checkOverride(tree, t2, origin, m);
2257 }
2258 }
2259
2260 final boolean explicitOverride = m.attribute(syms.overrideType.tsym) != null;
2261 // Check if this method must override a super method due to being annotated with @Override
2262 // or by virtue of being a member of a diamond inferred anonymous class. Latter case is to
2263 // be treated "as if as they were annotated" with @Override.
2264 boolean mustOverride = explicitOverride ||
2265 (env.info.isAnonymousDiamond && !m.isConstructor() && !m.isPrivate());
2266 if (mustOverride && !isOverrider(m)) {
2267 DiagnosticPosition pos = tree.pos();
2268 for (JCAnnotation a : tree.getModifiers().annotations) {
2269 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2270 pos = a.pos();
2271 break;
2272 }
2273 }
2274 log.error(pos,
2275 explicitOverride ? (m.isStatic() ? Errors.StaticMethodsCannotBeAnnotatedWithOverride : Errors.MethodDoesNotOverrideSuperclass) :
2276 Errors.AnonymousDiamondMethodDoesNotOverrideSuperclass(Fragments.DiamondAnonymousMethodsImplicitlyOverride));
2277 }
2278 }
2279
2280 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
2281 TypeSymbol c = site.tsym;
2282 for (Symbol sym : c.members().getSymbolsByName(m.name)) {
2283 if (m.overrides(sym, origin, types, false)) {
2284 if ((sym.flags() & ABSTRACT) == 0) {
2285 checkOverride(tree, m, (MethodSymbol)sym, origin);
2286 }
2287 }
2288 }
2289 }
2290
2291 private Predicate<Symbol> equalsHasCodeFilter = s -> MethodSymbol.implementation_filter.test(s) &&
2292 (s.flags() & BAD_OVERRIDE) == 0;
2293
2294 public void checkClassOverrideEqualsAndHashIfNeeded(DiagnosticPosition pos,
2295 ClassSymbol someClass) {
2296 /* At present, annotations cannot possibly have a method that is override
2297 * equivalent with Object.equals(Object) but in any case the condition is
2298 * fine for completeness.
2299 */
2300 if (someClass == (ClassSymbol)syms.objectType.tsym ||
2301 someClass.isInterface() || someClass.isEnum() ||
2302 (someClass.flags() & ANNOTATION) != 0 ||
2303 (someClass.flags() & ABSTRACT) != 0) return;
2304 //anonymous inner classes implementing interfaces need especial treatment
2305 if (someClass.isAnonymous()) {
2306 List<Type> interfaces = types.interfaces(someClass.type);
2307 if (interfaces != null && !interfaces.isEmpty() &&
2308 interfaces.head.tsym == syms.comparatorType.tsym) return;
2309 }
2310 checkClassOverrideEqualsAndHash(pos, someClass);
2311 }
2312
2313 private void checkClassOverrideEqualsAndHash(DiagnosticPosition pos,
2314 ClassSymbol someClass) {
2315 if (lint.isEnabled(LintCategory.OVERRIDES)) {
2316 MethodSymbol equalsAtObject = (MethodSymbol)syms.objectType
2317 .tsym.members().findFirst(names.equals);
2318 MethodSymbol hashCodeAtObject = (MethodSymbol)syms.objectType
2319 .tsym.members().findFirst(names.hashCode);
2320 MethodSymbol equalsImpl = types.implementation(equalsAtObject,
2321 someClass, false, equalsHasCodeFilter);
2322 boolean overridesEquals = equalsImpl != null &&
2323 equalsImpl.owner == someClass;
2324 boolean overridesHashCode = types.implementation(hashCodeAtObject,
2325 someClass, false, equalsHasCodeFilter) != hashCodeAtObject;
2326
2327 if (overridesEquals && !overridesHashCode) {
2328 log.warning(LintCategory.OVERRIDES, pos,
2329 Warnings.OverrideEqualsButNotHashcode(someClass));
2330 }
2331 }
2332 }
2333
2334 public void checkHasMain(DiagnosticPosition pos, ClassSymbol c) {
2335 boolean found = false;
2336
2337 for (Symbol sym : c.members().getSymbolsByName(names.main)) {
2338 if (sym.kind == MTH && (sym.flags() & PRIVATE) == 0) {
2339 MethodSymbol meth = (MethodSymbol)sym;
2340 if (!types.isSameType(meth.getReturnType(), syms.voidType)) {
2341 continue;
2342 }
2343 if (meth.params.isEmpty()) {
2344 found = true;
2345 break;
2346 }
2347 if (meth.params.size() != 1) {
2348 continue;
2349 }
2350 if (!types.isSameType(meth.params.head.type, types.makeArrayType(syms.stringType))) {
2351 continue;
2352 }
2353
2354 found = true;
2355 break;
2356 }
2357 }
2358
2359 if (!found) {
2360 log.error(pos, Errors.ImplicitClassDoesNotHaveMainMethod);
2361 }
2362 }
2363
2364 public void checkModuleName (JCModuleDecl tree) {
2365 Name moduleName = tree.sym.name;
2366 Assert.checkNonNull(moduleName);
2367 if (lint.isEnabled(LintCategory.MODULE)) {
2368 JCExpression qualId = tree.qualId;
2369 while (qualId != null) {
2370 Name componentName;
2371 DiagnosticPosition pos;
2372 switch (qualId.getTag()) {
2373 case SELECT:
2374 JCFieldAccess selectNode = ((JCFieldAccess) qualId);
2375 componentName = selectNode.name;
2376 pos = selectNode.pos();
2377 qualId = selectNode.selected;
2378 break;
2379 case IDENT:
2380 componentName = ((JCIdent) qualId).name;
2381 pos = qualId.pos();
2382 qualId = null;
2383 break;
2384 default:
2385 throw new AssertionError("Unexpected qualified identifier: " + qualId.toString());
2386 }
2387 if (componentName != null) {
2388 String moduleNameComponentString = componentName.toString();
2389 int nameLength = moduleNameComponentString.length();
2390 if (nameLength > 0 && Character.isDigit(moduleNameComponentString.charAt(nameLength - 1))) {
2391 log.warning(Lint.LintCategory.MODULE, pos, Warnings.PoorChoiceForModuleName(componentName));
2392 }
2393 }
2394 }
2395 }
2396 }
2397
2398 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
2399 ClashFilter cf = new ClashFilter(origin.type);
2400 return (cf.test(s1) &&
2401 cf.test(s2) &&
2402 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
2403 }
2404
2405
2406 /** Check that all abstract members of given class have definitions.
2407 * @param pos Position to be used for error reporting.
2408 * @param c The class.
2409 */
2410 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
2411 MethodSymbol undef = types.firstUnimplementedAbstract(c);
2412 if (undef != null) {
2413 MethodSymbol undef1 =
2414 new MethodSymbol(undef.flags(), undef.name,
2415 types.memberType(c.type, undef), undef.owner);
2416 log.error(pos,
2417 Errors.DoesNotOverrideAbstract(c, undef1, undef1.location()));
2418 }
2419 }
2420
2421 void checkNonCyclicDecl(JCClassDecl tree) {
2422 CycleChecker cc = new CycleChecker();
2423 cc.scan(tree);
2424 if (!cc.errorFound && !cc.partialCheck) {
2425 tree.sym.flags_field |= ACYCLIC;
2426 }
2427 }
2428
2429 class CycleChecker extends TreeScanner {
2430
2431 Set<Symbol> seenClasses = new HashSet<>();
2432 boolean errorFound = false;
2433 boolean partialCheck = false;
2434
2435 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
2436 if (sym != null && sym.kind == TYP) {
2437 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
2438 if (classEnv != null) {
2439 DiagnosticSource prevSource = log.currentSource();
2440 try {
2441 log.useSource(classEnv.toplevel.sourcefile);
2442 scan(classEnv.tree);
2443 }
2444 finally {
2445 log.useSource(prevSource.getFile());
2446 }
2447 } else if (sym.kind == TYP) {
2448 checkClass(pos, sym, List.nil());
2449 }
2450 } else if (sym == null || sym.kind != PCK) {
2451 //not completed yet
2452 partialCheck = true;
2453 }
2454 }
2455
2456 @Override
2457 public void visitSelect(JCFieldAccess tree) {
2458 super.visitSelect(tree);
2459 checkSymbol(tree.pos(), tree.sym);
2460 }
2461
2462 @Override
2463 public void visitIdent(JCIdent tree) {
2464 checkSymbol(tree.pos(), tree.sym);
2465 }
2466
2467 @Override
2468 public void visitTypeApply(JCTypeApply tree) {
2469 scan(tree.clazz);
2470 }
2471
2472 @Override
2473 public void visitTypeArray(JCArrayTypeTree tree) {
2474 scan(tree.elemtype);
2475 }
2476
2477 @Override
2478 public void visitClassDef(JCClassDecl tree) {
2479 List<JCTree> supertypes = List.nil();
2480 if (tree.getExtendsClause() != null) {
2481 supertypes = supertypes.prepend(tree.getExtendsClause());
2482 }
2483 if (tree.getImplementsClause() != null) {
2484 for (JCTree intf : tree.getImplementsClause()) {
2485 supertypes = supertypes.prepend(intf);
2486 }
2487 }
2488 checkClass(tree.pos(), tree.sym, supertypes);
2489 }
2490
2491 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
2492 if ((c.flags_field & ACYCLIC) != 0)
2493 return;
2494 if (seenClasses.contains(c)) {
2495 errorFound = true;
2496 noteCyclic(pos, (ClassSymbol)c);
2497 } else if (!c.type.isErroneous()) {
2498 try {
2499 seenClasses.add(c);
2500 if (c.type.hasTag(CLASS)) {
2501 if (supertypes.nonEmpty()) {
2502 scan(supertypes);
2503 }
2504 else {
2505 ClassType ct = (ClassType)c.type;
2506 if (ct.supertype_field == null ||
2507 ct.interfaces_field == null) {
2508 //not completed yet
2509 partialCheck = true;
2510 return;
2511 }
2512 checkSymbol(pos, ct.supertype_field.tsym);
2513 for (Type intf : ct.interfaces_field) {
2514 checkSymbol(pos, intf.tsym);
2515 }
2516 }
2517 if (c.owner.kind == TYP) {
2518 checkSymbol(pos, c.owner);
2519 }
2520 }
2521 } finally {
2522 seenClasses.remove(c);
2523 }
2524 }
2525 }
2526 }
2527
2528 /** Check for cyclic references. Issue an error if the
2529 * symbol of the type referred to has a LOCKED flag set.
2530 *
2531 * @param pos Position to be used for error reporting.
2532 * @param t The type referred to.
2533 */
2534 void checkNonCyclic(DiagnosticPosition pos, Type t) {
2535 checkNonCyclicInternal(pos, t);
2536 }
2537
2538
2539 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
2540 checkNonCyclic1(pos, t, List.nil());
2541 }
2542
2543 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
2544 final TypeVar tv;
2545 if (t.hasTag(TYPEVAR) && (t.tsym.flags() & UNATTRIBUTED) != 0)
2546 return;
2547 if (seen.contains(t)) {
2548 tv = (TypeVar)t;
2549 tv.setUpperBound(types.createErrorType(t));
2550 log.error(pos, Errors.CyclicInheritance(t));
2551 } else if (t.hasTag(TYPEVAR)) {
2552 tv = (TypeVar)t;
2553 seen = seen.prepend(tv);
2554 for (Type b : types.getBounds(tv))
2555 checkNonCyclic1(pos, b, seen);
2556 }
2557 }
2558
2559 /** Check for cyclic references. Issue an error if the
2560 * symbol of the type referred to has a LOCKED flag set.
2561 *
2562 * @param pos Position to be used for error reporting.
2563 * @param t The type referred to.
2564 * @return True if the check completed on all attributed classes
2565 */
2566 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
2567 boolean complete = true; // was the check complete?
2568 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
2569 Symbol c = t.tsym;
2570 if ((c.flags_field & ACYCLIC) != 0) return true;
2571
2572 if ((c.flags_field & LOCKED) != 0) {
2573 noteCyclic(pos, (ClassSymbol)c);
2574 } else if (!c.type.isErroneous()) {
2575 try {
2576 c.flags_field |= LOCKED;
2577 if (c.type.hasTag(CLASS)) {
2578 ClassType clazz = (ClassType)c.type;
2579 if (clazz.interfaces_field != null)
2580 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
2581 complete &= checkNonCyclicInternal(pos, l.head);
2582 if (clazz.supertype_field != null) {
2583 Type st = clazz.supertype_field;
2584 if (st != null && st.hasTag(CLASS))
2585 complete &= checkNonCyclicInternal(pos, st);
2586 }
2587 if (c.owner.kind == TYP)
2588 complete &= checkNonCyclicInternal(pos, c.owner.type);
2589 }
2590 } finally {
2591 c.flags_field &= ~LOCKED;
2592 }
2593 }
2594 if (complete)
2595 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.isCompleted();
2596 if (complete) c.flags_field |= ACYCLIC;
2597 return complete;
2598 }
2599
2600 /** Note that we found an inheritance cycle. */
2601 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
2602 log.error(pos, Errors.CyclicInheritance(c));
2603 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2604 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2605 Type st = types.supertype(c.type);
2606 if (st.hasTag(CLASS))
2607 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2608 c.type = types.createErrorType(c, c.type);
2609 c.flags_field |= ACYCLIC;
2610 }
2611
2612 /** Check that all methods which implement some
2613 * method conform to the method they implement.
2614 * @param tree The class definition whose members are checked.
2615 */
2616 void checkImplementations(JCClassDecl tree) {
2617 checkImplementations(tree, tree.sym, tree.sym);
2618 }
2619 //where
2620 /** Check that all methods which implement some
2621 * method in `ic' conform to the method they implement.
2622 */
2623 void checkImplementations(JCTree tree, ClassSymbol origin, ClassSymbol ic) {
2624 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2625 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2626 if ((lc.flags() & ABSTRACT) != 0) {
2627 for (Symbol sym : lc.members().getSymbols(NON_RECURSIVE)) {
2628 if (sym.kind == MTH &&
2629 (sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2630 MethodSymbol absmeth = (MethodSymbol)sym;
2631 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2632 if (implmeth != null && implmeth != absmeth &&
2633 (implmeth.owner.flags() & INTERFACE) ==
2634 (origin.flags() & INTERFACE)) {
2635 // don't check if implmeth is in a class, yet
2636 // origin is an interface. This case arises only
2637 // if implmeth is declared in Object. The reason is
2638 // that interfaces really don't inherit from
2639 // Object it's just that the compiler represents
2640 // things that way.
2641 checkOverride(tree, implmeth, absmeth, origin);
2642 }
2643 }
2644 }
2645 }
2646 }
2647 }
2648
2649 /** Check that all abstract methods implemented by a class are
2650 * mutually compatible.
2651 * @param pos Position to be used for error reporting.
2652 * @param c The class whose interfaces are checked.
2653 */
2654 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2655 List<Type> supertypes = types.interfaces(c);
2656 Type supertype = types.supertype(c);
2657 if (supertype.hasTag(CLASS) &&
2658 (supertype.tsym.flags() & ABSTRACT) != 0)
2659 supertypes = supertypes.prepend(supertype);
2660 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2661 if (!l.head.getTypeArguments().isEmpty() &&
2662 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2663 return;
2664 for (List<Type> m = supertypes; m != l; m = m.tail)
2665 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2666 return;
2667 }
2668 checkCompatibleConcretes(pos, c);
2669
2670 boolean cIsValue = (c.tsym.flags() & VALUE_CLASS) != 0;
2671 Type identitySuper = null, valueSuper = null;
2672 for (Type t : types.closure(c)) {
2673 if (t != c) {
2674 if ((t.tsym.flags() & IDENTITY_TYPE) != 0 && (t.tsym.flags() & VALUE_BASED) == 0)
2675 identitySuper = t;
2676 else if ((t.tsym.flags() & VALUE_CLASS) != 0)
2677 valueSuper = t;
2678 if (cIsValue && identitySuper != null && identitySuper.tsym != syms.objectType.tsym) { // Object is special
2679 log.error(pos, Errors.ValueTypeHasIdentitySuperType(c, identitySuper));
2680 break;
2681 }
2682 }
2683 }
2684 }
2685
2686 /** Check that all non-override equivalent methods accessible from 'site'
2687 * are mutually compatible (JLS 8.4.8/9.4.1).
2688 *
2689 * @param pos Position to be used for error reporting.
2690 * @param site The class whose methods are checked.
2691 * @param sym The method symbol to be checked.
2692 */
2693 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2694 ClashFilter cf = new ClashFilter(site);
2695 //for each method m1 that is overridden (directly or indirectly)
2696 //by method 'sym' in 'site'...
2697
2698 ArrayList<Symbol> symbolsByName = new ArrayList<>();
2699 types.membersClosure(site, false).getSymbolsByName(sym.name, cf).forEach(symbolsByName::add);
2700 for (Symbol m1 : symbolsByName) {
2701 if (!sym.overrides(m1, site.tsym, types, false)) {
2702 continue;
2703 }
2704
2705 //...check each method m2 that is a member of 'site'
2706 for (Symbol m2 : symbolsByName) {
2707 if (m2 == m1) continue;
2708 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2709 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2710 if (!types.isSubSignature(sym.type, types.memberType(site, m2)) &&
2711 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) {
2712 sym.flags_field |= CLASH;
2713 if (m1 == sym) {
2714 log.error(pos, Errors.NameClashSameErasureNoOverride(
2715 m1.name, types.memberType(site, m1).asMethodType().getParameterTypes(), m1.location(),
2716 m2.name, types.memberType(site, m2).asMethodType().getParameterTypes(), m2.location()));
2717 } else {
2718 ClassType ct = (ClassType)site;
2719 String kind = ct.isInterface() ? "interface" : "class";
2720 log.error(pos, Errors.NameClashSameErasureNoOverride1(
2721 kind,
2722 ct.tsym.name,
2723 m1.name,
2724 types.memberType(site, m1).asMethodType().getParameterTypes(),
2725 m1.location(),
2726 m2.name,
2727 types.memberType(site, m2).asMethodType().getParameterTypes(),
2728 m2.location()));
2729 }
2730 return;
2731 }
2732 }
2733 }
2734 }
2735
2736 /** Check that all static methods accessible from 'site' are
2737 * mutually compatible (JLS 8.4.8).
2738 *
2739 * @param pos Position to be used for error reporting.
2740 * @param site The class whose methods are checked.
2741 * @param sym The method symbol to be checked.
2742 */
2743 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2744 ClashFilter cf = new ClashFilter(site);
2745 //for each method m1 that is a member of 'site'...
2746 for (Symbol s : types.membersClosure(site, true).getSymbolsByName(sym.name, cf)) {
2747 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2748 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2749 if (!types.isSubSignature(sym.type, types.memberType(site, s))) {
2750 if (types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2751 log.error(pos,
2752 Errors.NameClashSameErasureNoHide(sym, sym.location(), s, s.location()));
2753 return;
2754 }
2755 }
2756 }
2757 }
2758
2759 //where
2760 private class ClashFilter implements Predicate<Symbol> {
2761
2762 Type site;
2763
2764 ClashFilter(Type site) {
2765 this.site = site;
2766 }
2767
2768 boolean shouldSkip(Symbol s) {
2769 return (s.flags() & CLASH) != 0 &&
2770 s.owner == site.tsym;
2771 }
2772
2773 @Override
2774 public boolean test(Symbol s) {
2775 return s.kind == MTH &&
2776 (s.flags() & SYNTHETIC) == 0 &&
2777 !shouldSkip(s) &&
2778 s.isInheritedIn(site.tsym, types) &&
2779 !s.isConstructor();
2780 }
2781 }
2782
2783 void checkDefaultMethodClashes(DiagnosticPosition pos, Type site) {
2784 DefaultMethodClashFilter dcf = new DefaultMethodClashFilter(site);
2785 for (Symbol m : types.membersClosure(site, false).getSymbols(dcf)) {
2786 Assert.check(m.kind == MTH);
2787 List<MethodSymbol> prov = types.interfaceCandidates(site, (MethodSymbol)m);
2788 if (prov.size() > 1) {
2789 ListBuffer<Symbol> abstracts = new ListBuffer<>();
2790 ListBuffer<Symbol> defaults = new ListBuffer<>();
2791 for (MethodSymbol provSym : prov) {
2792 if ((provSym.flags() & DEFAULT) != 0) {
2793 defaults = defaults.append(provSym);
2794 } else if ((provSym.flags() & ABSTRACT) != 0) {
2795 abstracts = abstracts.append(provSym);
2796 }
2797 if (defaults.nonEmpty() && defaults.size() + abstracts.size() >= 2) {
2798 //strong semantics - issue an error if two sibling interfaces
2799 //have two override-equivalent defaults - or if one is abstract
2800 //and the other is default
2801 Fragment diagKey;
2802 Symbol s1 = defaults.first();
2803 Symbol s2;
2804 if (defaults.size() > 1) {
2805 s2 = defaults.toList().tail.head;
2806 diagKey = Fragments.IncompatibleUnrelatedDefaults(Kinds.kindName(site.tsym), site,
2807 m.name, types.memberType(site, m).getParameterTypes(),
2808 s1.location(), s2.location());
2809
2810 } else {
2811 s2 = abstracts.first();
2812 diagKey = Fragments.IncompatibleAbstractDefault(Kinds.kindName(site.tsym), site,
2813 m.name, types.memberType(site, m).getParameterTypes(),
2814 s1.location(), s2.location());
2815 }
2816 log.error(pos, Errors.TypesIncompatible(s1.location().type, s2.location().type, diagKey));
2817 break;
2818 }
2819 }
2820 }
2821 }
2822 }
2823
2824 //where
2825 private class DefaultMethodClashFilter implements Predicate<Symbol> {
2826
2827 Type site;
2828
2829 DefaultMethodClashFilter(Type site) {
2830 this.site = site;
2831 }
2832
2833 @Override
2834 public boolean test(Symbol s) {
2835 return s.kind == MTH &&
2836 (s.flags() & DEFAULT) != 0 &&
2837 s.isInheritedIn(site.tsym, types) &&
2838 !s.isConstructor();
2839 }
2840 }
2841
2842 /** Report warnings for potentially ambiguous method declarations in the given site. */
2843 void checkPotentiallyAmbiguousOverloads(JCClassDecl tree, Type site) {
2844
2845 // Skip if warning not enabled
2846 if (!lint.isEnabled(LintCategory.OVERLOADS))
2847 return;
2848
2849 // Gather all of site's methods, including overridden methods, grouped by name (except Object methods)
2850 List<java.util.List<MethodSymbol>> methodGroups = methodsGroupedByName(site,
2851 new PotentiallyAmbiguousFilter(site), ArrayList::new);
2852
2853 // Build the predicate that determines if site is responsible for an ambiguity
2854 BiPredicate<MethodSymbol, MethodSymbol> responsible = buildResponsiblePredicate(site, methodGroups);
2855
2856 // Now remove overridden methods from each group, leaving only site's actual members
2857 methodGroups.forEach(list -> removePreempted(list, (m1, m2) -> m1.overrides(m2, site.tsym, types, false)));
2858
2859 // Allow site's own declared methods (only) to apply @SuppressWarnings("overloads")
2860 methodGroups.forEach(list -> list.removeIf(
2861 m -> m.owner == site.tsym && !lint.augment(m).isEnabled(LintCategory.OVERLOADS)));
2862
2863 // Warn about ambiguous overload method pairs for which site is responsible
2864 methodGroups.forEach(list -> compareAndRemove(list, (m1, m2) -> {
2865
2866 // See if this is an ambiguous overload for which "site" is responsible
2867 if (!potentiallyAmbiguousOverload(site, m1, m2) || !responsible.test(m1, m2))
2868 return 0;
2869
2870 // Locate the warning at one of the methods, if possible
2871 DiagnosticPosition pos =
2872 m1.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m1, tree) :
2873 m2.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m2, tree) :
2874 tree.pos();
2875
2876 // Log the warning
2877 log.warning(LintCategory.OVERLOADS, pos,
2878 Warnings.PotentiallyAmbiguousOverload(
2879 m1.asMemberOf(site, types), m1.location(),
2880 m2.asMemberOf(site, types), m2.location()));
2881
2882 // Don't warn again for either of these two methods
2883 return FIRST | SECOND;
2884 }));
2885 }
2886
2887 /** Build a predicate that determines, given two methods that are members of the given class,
2888 * whether the class should be held "responsible" if the methods are potentially ambiguous.
2889 *
2890 * Sometimes ambiguous methods are unavoidable because they're inherited from a supertype.
2891 * For example, any subtype of Spliterator.OfInt will have ambiguities for both
2892 * forEachRemaining() and tryAdvance() (in both cases the overloads are IntConsumer and
2893 * Consumer<? super Integer>). So we only want to "blame" a class when that class is
2894 * itself responsible for creating the ambiguity. We declare that a class C is "responsible"
2895 * for the ambiguity between two methods m1 and m2 if there is no direct supertype T of C
2896 * such that m1 and m2, or some overrides thereof, both exist in T and are ambiguous in T.
2897 * As an optimization, we first check if either method is declared in C and does not override
2898 * any other methods; in this case the class is definitely responsible.
2899 */
2900 BiPredicate<MethodSymbol, MethodSymbol> buildResponsiblePredicate(Type site,
2901 List<? extends Collection<MethodSymbol>> methodGroups) {
2902
2903 // Define the "overrides" predicate
2904 BiPredicate<MethodSymbol, MethodSymbol> overrides = (m1, m2) -> m1.overrides(m2, site.tsym, types, false);
2905
2906 // Map each method declared in site to a list of the supertype method(s) it directly overrides
2907 HashMap<MethodSymbol, ArrayList<MethodSymbol>> overriddenMethodsMap = new HashMap<>();
2908 methodGroups.forEach(list -> {
2909 for (MethodSymbol m : list) {
2910
2911 // Skip methods not declared in site
2912 if (m.owner != site.tsym)
2913 continue;
2914
2915 // Gather all supertype methods overridden by m, directly or indirectly
2916 ArrayList<MethodSymbol> overriddenMethods = list.stream()
2917 .filter(m2 -> m2 != m && overrides.test(m, m2))
2918 .collect(Collectors.toCollection(ArrayList::new));
2919
2920 // Eliminate non-direct overrides
2921 removePreempted(overriddenMethods, overrides);
2922
2923 // Add to map
2924 overriddenMethodsMap.put(m, overriddenMethods);
2925 }
2926 });
2927
2928 // Build the predicate
2929 return (m1, m2) -> {
2930
2931 // Get corresponding supertype methods (if declared in site)
2932 java.util.List<MethodSymbol> overriddenMethods1 = overriddenMethodsMap.get(m1);
2933 java.util.List<MethodSymbol> overriddenMethods2 = overriddenMethodsMap.get(m2);
2934
2935 // Quick check for the case where a method was added by site itself
2936 if (overriddenMethods1 != null && overriddenMethods1.isEmpty())
2937 return true;
2938 if (overriddenMethods2 != null && overriddenMethods2.isEmpty())
2939 return true;
2940
2941 // Get each method's corresponding method(s) from supertypes of site
2942 java.util.List<MethodSymbol> supertypeMethods1 = overriddenMethods1 != null ?
2943 overriddenMethods1 : Collections.singletonList(m1);
2944 java.util.List<MethodSymbol> supertypeMethods2 = overriddenMethods2 != null ?
2945 overriddenMethods2 : Collections.singletonList(m2);
2946
2947 // See if we can blame some direct supertype instead
2948 return types.directSupertypes(site).stream()
2949 .filter(stype -> stype != syms.objectType)
2950 .map(stype -> stype.tsym.type) // view supertype in its original form
2951 .noneMatch(stype -> {
2952 for (MethodSymbol sm1 : supertypeMethods1) {
2953 if (!types.isSubtype(types.erasure(stype), types.erasure(sm1.owner.type)))
2954 continue;
2955 for (MethodSymbol sm2 : supertypeMethods2) {
2956 if (!types.isSubtype(types.erasure(stype), types.erasure(sm2.owner.type)))
2957 continue;
2958 if (potentiallyAmbiguousOverload(stype, sm1, sm2))
2959 return true;
2960 }
2961 }
2962 return false;
2963 });
2964 };
2965 }
2966
2967 /** Gather all of site's methods, including overridden methods, grouped and sorted by name,
2968 * after applying the given filter.
2969 */
2970 <C extends Collection<MethodSymbol>> List<C> methodsGroupedByName(Type site,
2971 Predicate<Symbol> filter, Supplier<? extends C> groupMaker) {
2972 Iterable<Symbol> symbols = types.membersClosure(site, false).getSymbols(filter, RECURSIVE);
2973 return StreamSupport.stream(symbols.spliterator(), false)
2974 .map(MethodSymbol.class::cast)
2975 .collect(Collectors.groupingBy(m -> m.name, Collectors.toCollection(groupMaker)))
2976 .entrySet()
2977 .stream()
2978 .sorted(Comparator.comparing(e -> e.getKey().toString()))
2979 .map(Map.Entry::getValue)
2980 .collect(List.collector());
2981 }
2982
2983 /** Compare elements in a list pair-wise in order to remove some of them.
2984 * @param list mutable list of items
2985 * @param comparer returns flag bit(s) to remove FIRST and/or SECOND
2986 */
2987 <T> void compareAndRemove(java.util.List<T> list, ToIntBiFunction<? super T, ? super T> comparer) {
2988 for (int index1 = 0; index1 < list.size() - 1; index1++) {
2989 T item1 = list.get(index1);
2990 for (int index2 = index1 + 1; index2 < list.size(); index2++) {
2991 T item2 = list.get(index2);
2992 int flags = comparer.applyAsInt(item1, item2);
2993 if ((flags & SECOND) != 0)
2994 list.remove(index2--); // remove item2
2995 if ((flags & FIRST) != 0) {
2996 list.remove(index1--); // remove item1
2997 break;
2998 }
2999 }
3000 }
3001 }
3002
3003 /** Remove elements in a list that are preempted by some other element in the list.
3004 * @param list mutable list of items
3005 * @param preempts decides if one item preempts another, causing the second one to be removed
3006 */
3007 <T> void removePreempted(java.util.List<T> list, BiPredicate<? super T, ? super T> preempts) {
3008 compareAndRemove(list, (item1, item2) -> {
3009 int flags = 0;
3010 if (preempts.test(item1, item2))
3011 flags |= SECOND;
3012 if (preempts.test(item2, item1))
3013 flags |= FIRST;
3014 return flags;
3015 });
3016 }
3017
3018 /** Filters method candidates for the "potentially ambiguous method" check */
3019 class PotentiallyAmbiguousFilter extends ClashFilter {
3020
3021 PotentiallyAmbiguousFilter(Type site) {
3022 super(site);
3023 }
3024
3025 @Override
3026 boolean shouldSkip(Symbol s) {
3027 return s.owner.type.tsym == syms.objectType.tsym || super.shouldSkip(s);
3028 }
3029 }
3030
3031 /**
3032 * Report warnings for potentially ambiguous method declarations. Two declarations
3033 * are potentially ambiguous if they feature two unrelated functional interface
3034 * in same argument position (in which case, a call site passing an implicit
3035 * lambda would be ambiguous). This assumes they already have the same name.
3036 */
3037 boolean potentiallyAmbiguousOverload(Type site, MethodSymbol msym1, MethodSymbol msym2) {
3038 Assert.check(msym1.name == msym2.name);
3039 if (msym1 == msym2)
3040 return false;
3041 Type mt1 = types.memberType(site, msym1);
3042 Type mt2 = types.memberType(site, msym2);
3043 //if both generic methods, adjust type variables
3044 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL) &&
3045 types.hasSameBounds((ForAll)mt1, (ForAll)mt2)) {
3046 mt2 = types.subst(mt2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
3047 }
3048 //expand varargs methods if needed
3049 int maxLength = Math.max(mt1.getParameterTypes().length(), mt2.getParameterTypes().length());
3050 List<Type> args1 = rs.adjustArgs(mt1.getParameterTypes(), msym1, maxLength, true);
3051 List<Type> args2 = rs.adjustArgs(mt2.getParameterTypes(), msym2, maxLength, true);
3052 //if arities don't match, exit
3053 if (args1.length() != args2.length())
3054 return false;
3055 boolean potentiallyAmbiguous = false;
3056 while (args1.nonEmpty() && args2.nonEmpty()) {
3057 Type s = args1.head;
3058 Type t = args2.head;
3059 if (!types.isSubtype(t, s) && !types.isSubtype(s, t)) {
3060 if (types.isFunctionalInterface(s) && types.isFunctionalInterface(t) &&
3061 types.findDescriptorType(s).getParameterTypes().length() > 0 &&
3062 types.findDescriptorType(s).getParameterTypes().length() ==
3063 types.findDescriptorType(t).getParameterTypes().length()) {
3064 potentiallyAmbiguous = true;
3065 } else {
3066 return false;
3067 }
3068 }
3069 args1 = args1.tail;
3070 args2 = args2.tail;
3071 }
3072 return potentiallyAmbiguous;
3073 }
3074
3075 void checkAccessFromSerializableElement(final JCTree tree, boolean isLambda) {
3076 if (warnOnAnyAccessToMembers ||
3077 (lint.isEnabled(LintCategory.SERIAL) &&
3078 !lint.isSuppressed(LintCategory.SERIAL) &&
3079 isLambda)) {
3080 Symbol sym = TreeInfo.symbol(tree);
3081 if (!sym.kind.matches(KindSelector.VAL_MTH)) {
3082 return;
3083 }
3084
3085 if (sym.kind == VAR) {
3086 if ((sym.flags() & PARAMETER) != 0 ||
3087 sym.isDirectlyOrIndirectlyLocal() ||
3088 sym.name == names._this ||
3089 sym.name == names._super) {
3090 return;
3091 }
3092 }
3093
3094 if (!types.isSubtype(sym.owner.type, syms.serializableType) &&
3095 isEffectivelyNonPublic(sym)) {
3096 if (isLambda) {
3097 if (belongsToRestrictedPackage(sym)) {
3098 log.warning(LintCategory.SERIAL, tree.pos(),
3099 Warnings.AccessToMemberFromSerializableLambda(sym));
3100 }
3101 } else {
3102 log.warning(tree.pos(),
3103 Warnings.AccessToMemberFromSerializableElement(sym));
3104 }
3105 }
3106 }
3107 }
3108
3109 private boolean isEffectivelyNonPublic(Symbol sym) {
3110 if (sym.packge() == syms.rootPackage) {
3111 return false;
3112 }
3113
3114 while (sym.kind != PCK) {
3115 if ((sym.flags() & PUBLIC) == 0) {
3116 return true;
3117 }
3118 sym = sym.owner;
3119 }
3120 return false;
3121 }
3122
3123 private boolean belongsToRestrictedPackage(Symbol sym) {
3124 String fullName = sym.packge().fullname.toString();
3125 return fullName.startsWith("java.") ||
3126 fullName.startsWith("javax.") ||
3127 fullName.startsWith("sun.") ||
3128 fullName.contains(".internal.");
3129 }
3130
3131 /** Check that class c does not implement directly or indirectly
3132 * the same parameterized interface with two different argument lists.
3133 * @param pos Position to be used for error reporting.
3134 * @param type The type whose interfaces are checked.
3135 */
3136 void checkClassBounds(DiagnosticPosition pos, Type type) {
3137 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
3138 }
3139 //where
3140 /** Enter all interfaces of type `type' into the hash table `seensofar'
3141 * with their class symbol as key and their type as value. Make
3142 * sure no class is entered with two different types.
3143 */
3144 void checkClassBounds(DiagnosticPosition pos,
3145 Map<TypeSymbol,Type> seensofar,
3146 Type type) {
3147 if (type.isErroneous()) return;
3148 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
3149 Type it = l.head;
3150 if (type.hasTag(CLASS) && !it.hasTag(CLASS)) continue; // JLS 8.1.5
3151
3152 Type oldit = seensofar.put(it.tsym, it);
3153 if (oldit != null) {
3154 List<Type> oldparams = oldit.allparams();
3155 List<Type> newparams = it.allparams();
3156 if (!types.containsTypeEquivalent(oldparams, newparams))
3157 log.error(pos,
3158 Errors.CantInheritDiffArg(it.tsym,
3159 Type.toString(oldparams),
3160 Type.toString(newparams)));
3161 }
3162 checkClassBounds(pos, seensofar, it);
3163 }
3164 Type st = types.supertype(type);
3165 if (type.hasTag(CLASS) && !st.hasTag(CLASS)) return; // JLS 8.1.4
3166 if (st != Type.noType) checkClassBounds(pos, seensofar, st);
3167 }
3168
3169 /** Enter interface into into set.
3170 * If it existed already, issue a "repeated interface" error.
3171 */
3172 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Symbol> its) {
3173 if (its.contains(it.tsym))
3174 log.error(pos, Errors.RepeatedInterface);
3175 else {
3176 its.add(it.tsym);
3177 }
3178 }
3179
3180 /* *************************************************************************
3181 * Check annotations
3182 **************************************************************************/
3183
3184 /**
3185 * Recursively validate annotations values
3186 */
3187 void validateAnnotationTree(JCTree tree) {
3188 class AnnotationValidator extends TreeScanner {
3189 @Override
3190 public void visitAnnotation(JCAnnotation tree) {
3191 if (!tree.type.isErroneous() && tree.type.tsym.isAnnotationType()) {
3192 super.visitAnnotation(tree);
3193 validateAnnotation(tree);
3194 }
3195 }
3196 }
3197 tree.accept(new AnnotationValidator());
3198 }
3199
3200 /**
3201 * {@literal
3202 * Annotation types are restricted to primitives, String, an
3203 * enum, an annotation, Class, Class<?>, Class<? extends
3204 * Anything>, arrays of the preceding.
3205 * }
3206 */
3207 void validateAnnotationType(JCTree restype) {
3208 // restype may be null if an error occurred, so don't bother validating it
3209 if (restype != null) {
3210 validateAnnotationType(restype.pos(), restype.type);
3211 }
3212 }
3213
3214 void validateAnnotationType(DiagnosticPosition pos, Type type) {
3215 if (type.isPrimitive()) return;
3216 if (types.isSameType(type, syms.stringType)) return;
3217 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
3218 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
3219 if (types.cvarLowerBound(type).tsym == syms.classType.tsym) return;
3220 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
3221 validateAnnotationType(pos, types.elemtype(type));
3222 return;
3223 }
3224 log.error(pos, Errors.InvalidAnnotationMemberType);
3225 }
3226
3227 /**
3228 * "It is also a compile-time error if any method declared in an
3229 * annotation type has a signature that is override-equivalent to
3230 * that of any public or protected method declared in class Object
3231 * or in the interface annotation.Annotation."
3232 *
3233 * @jls 9.6 Annotation Types
3234 */
3235 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
3236 for (Type sup = syms.annotationType; sup.hasTag(CLASS); sup = types.supertype(sup)) {
3237 Scope s = sup.tsym.members();
3238 for (Symbol sym : s.getSymbolsByName(m.name)) {
3239 if (sym.kind == MTH &&
3240 (sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
3241 types.overrideEquivalent(m.type, sym.type))
3242 log.error(pos, Errors.IntfAnnotationMemberClash(sym, sup));
3243 }
3244 }
3245 }
3246
3247 /** Check the annotations of a symbol.
3248 */
3249 public void validateAnnotations(List<JCAnnotation> annotations, JCTree declarationTree, Symbol s) {
3250 for (JCAnnotation a : annotations)
3251 validateAnnotation(a, declarationTree, s);
3252 }
3253
3254 /** Check the type annotations.
3255 */
3256 public void validateTypeAnnotations(List<JCAnnotation> annotations, Symbol s, boolean isTypeParameter) {
3257 for (JCAnnotation a : annotations)
3258 validateTypeAnnotation(a, s, isTypeParameter);
3259 }
3260
3261 /** Check an annotation of a symbol.
3262 */
3263 private void validateAnnotation(JCAnnotation a, JCTree declarationTree, Symbol s) {
3264 /** NOTE: if annotation processors are present, annotation processing rounds can happen after this method,
3265 * this can impact in particular records for which annotations are forcibly propagated.
3266 */
3267 validateAnnotationTree(a);
3268 boolean isRecordMember = ((s.flags_field & RECORD) != 0 || s.enclClass() != null && s.enclClass().isRecord());
3269
3270 boolean isRecordField = (s.flags_field & RECORD) != 0 &&
3271 declarationTree.hasTag(VARDEF) &&
3272 s.owner.kind == TYP;
3273
3274 if (isRecordField) {
3275 // first we need to check if the annotation is applicable to records
3276 Name[] targets = getTargetNames(a);
3277 boolean appliesToRecords = false;
3278 for (Name target : targets) {
3279 appliesToRecords =
3280 target == names.FIELD ||
3281 target == names.PARAMETER ||
3282 target == names.METHOD ||
3283 target == names.TYPE_USE ||
3284 target == names.RECORD_COMPONENT;
3285 if (appliesToRecords) {
3286 break;
3287 }
3288 }
3289 if (!appliesToRecords) {
3290 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3291 } else {
3292 /* lets now find the annotations in the field that are targeted to record components and append them to
3293 * the corresponding record component
3294 */
3295 ClassSymbol recordClass = (ClassSymbol) s.owner;
3296 RecordComponent rc = recordClass.getRecordComponent((VarSymbol)s);
3297 SymbolMetadata metadata = rc.getMetadata();
3298 if (metadata == null || metadata.isEmpty()) {
3299 /* if not is empty then we have already been here, which is the case if multiple annotations are applied
3300 * to the record component declaration
3301 */
3302 rc.appendAttributes(s.getRawAttributes().stream().filter(anno ->
3303 Arrays.stream(getTargetNames(anno.type.tsym)).anyMatch(name -> name == names.RECORD_COMPONENT)
3304 ).collect(List.collector()));
3305
3306 JCVariableDecl fieldAST = (JCVariableDecl) declarationTree;
3307 for (JCAnnotation fieldAnnot : fieldAST.mods.annotations) {
3308 for (JCAnnotation rcAnnot : rc.declarationFor().mods.annotations) {
3309 if (rcAnnot.pos == fieldAnnot.pos) {
3310 rcAnnot.setType(fieldAnnot.type);
3311 break;
3312 }
3313 }
3314 }
3315
3316 /* At this point, we used to carry over any type annotations from the VARDEF to the record component, but
3317 * that is problematic, since we get here only when *some* annotation is applied to the SE5 (declaration)
3318 * annotation location, inadvertently failing to carry over the type annotations when the VarDef has no
3319 * annotations in the SE5 annotation location.
3320 *
3321 * Now type annotations are assigned to record components in a method that would execute irrespective of
3322 * whether there are SE5 annotations on a VarDef viz com.sun.tools.javac.code.TypeAnnotations.TypeAnnotationPositions.visitVarDef
3323 */
3324 }
3325 }
3326 }
3327
3328 /* the section below is tricky. Annotations applied to record components are propagated to the corresponding
3329 * record member so if an annotation has target: FIELD, it is propagated to the corresponding FIELD, if it has
3330 * target METHOD, it is propagated to the accessor and so on. But at the moment when method members are generated
3331 * there is no enough information to propagate only the right annotations. So all the annotations are propagated
3332 * to all the possible locations.
3333 *
3334 * At this point we need to remove all the annotations that are not in place before going on with the annotation
3335 * party. On top of the above there is the issue that there is no AST representing record components, just symbols
3336 * so the corresponding field has been holding all the annotations and it's metadata has been modified as if it
3337 * was both a field and a record component.
3338 *
3339 * So there are two places where we need to trim annotations from: the metadata of the symbol and / or the modifiers
3340 * in the AST. Whatever is in the metadata will be written to the class file, whatever is in the modifiers could
3341 * be see by annotation processors.
3342 *
3343 * The metadata contains both type annotations and declaration annotations. At this point of the game we don't
3344 * need to care about type annotations, they are all in the right place. But we could need to remove declaration
3345 * annotations. So for declaration annotations if they are not applicable to the record member, excluding type
3346 * annotations which are already correct, then we will remove it. For the AST modifiers if the annotation is not
3347 * applicable either as type annotation and or declaration annotation, only in that case it will be removed.
3348 *
3349 * So it could be that annotation is removed as a declaration annotation but it is kept in the AST modifier for
3350 * further inspection by annotation processors.
3351 *
3352 * For example:
3353 *
3354 * import java.lang.annotation.*;
3355 *
3356 * @Target({ElementType.TYPE_USE, ElementType.RECORD_COMPONENT})
3357 * @Retention(RetentionPolicy.RUNTIME)
3358 * @interface Anno { }
3359 *
3360 * record R(@Anno String s) {}
3361 *
3362 * at this point we will have for the case of the generated field:
3363 * - @Anno in the modifier
3364 * - @Anno as a type annotation
3365 * - @Anno as a declaration annotation
3366 *
3367 * the last one should be removed because the annotation has not FIELD as target but it was applied as a
3368 * declaration annotation because the field was being treated both as a field and as a record component
3369 * as we have already copied the annotations to the record component, now the field doesn't need to hold
3370 * annotations that are not intended for it anymore. Still @Anno has to be kept in the AST's modifiers as it
3371 * is applicable as a type annotation to the type of the field.
3372 */
3373
3374 if (a.type.tsym.isAnnotationType()) {
3375 Optional<Set<Name>> applicableTargetsOp = getApplicableTargets(a, s);
3376 if (!applicableTargetsOp.isEmpty()) {
3377 Set<Name> applicableTargets = applicableTargetsOp.get();
3378 boolean notApplicableOrIsTypeUseOnly = applicableTargets.isEmpty() ||
3379 applicableTargets.size() == 1 && applicableTargets.contains(names.TYPE_USE);
3380 boolean isCompGeneratedRecordElement = isRecordMember && (s.flags_field & Flags.GENERATED_MEMBER) != 0;
3381 boolean isCompRecordElementWithNonApplicableDeclAnno = isCompGeneratedRecordElement && notApplicableOrIsTypeUseOnly;
3382
3383 if (applicableTargets.isEmpty() || isCompRecordElementWithNonApplicableDeclAnno) {
3384 if (isCompRecordElementWithNonApplicableDeclAnno) {
3385 /* so we have found an annotation that is not applicable to a record member that was generated by the
3386 * compiler. This was intentionally done at TypeEnter, now is the moment strip away the annotations
3387 * that are not applicable to the given record member
3388 */
3389 JCModifiers modifiers = TreeInfo.getModifiers(declarationTree);
3390 /* lets first remove the annotation from the modifier if it is not applicable, we have to check again as
3391 * it could be a type annotation
3392 */
3393 if (modifiers != null && applicableTargets.isEmpty()) {
3394 ListBuffer<JCAnnotation> newAnnotations = new ListBuffer<>();
3395 for (JCAnnotation anno : modifiers.annotations) {
3396 if (anno != a) {
3397 newAnnotations.add(anno);
3398 }
3399 }
3400 modifiers.annotations = newAnnotations.toList();
3401 }
3402 // now lets remove it from the symbol
3403 s.getMetadata().removeDeclarationMetadata(a.attribute);
3404 } else {
3405 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3406 }
3407 }
3408 /* if we are seeing the @SafeVarargs annotation applied to a compiler generated accessor,
3409 * then this is an error as we know that no compiler generated accessor will be a varargs
3410 * method, better to fail asap
3411 */
3412 if (isCompGeneratedRecordElement && !isRecordField && a.type.tsym == syms.trustMeType.tsym && declarationTree.hasTag(METHODDEF)) {
3413 log.error(a.pos(), Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym, Fragments.VarargsTrustmeOnNonVarargsAccessor(s)));
3414 }
3415 }
3416 }
3417
3418 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
3419 if (s.kind != TYP) {
3420 log.error(a.pos(), Errors.BadFunctionalIntfAnno);
3421 } else if (!s.isInterface() || (s.flags() & ANNOTATION) != 0) {
3422 log.error(a.pos(), Errors.BadFunctionalIntfAnno1(Fragments.NotAFunctionalIntf(s)));
3423 }
3424 }
3425 }
3426
3427 public void validateTypeAnnotation(JCAnnotation a, Symbol s, boolean isTypeParameter) {
3428 Assert.checkNonNull(a.type);
3429 // we just want to validate that the anotation doesn't have any wrong target
3430 if (s != null) getApplicableTargets(a, s);
3431 validateAnnotationTree(a);
3432
3433 if (a.hasTag(TYPE_ANNOTATION) &&
3434 !a.annotationType.type.isErroneous() &&
3435 !isTypeAnnotation(a, isTypeParameter)) {
3436 log.error(a.pos(), Errors.AnnotationTypeNotApplicableToType(a.type));
3437 }
3438 }
3439
3440 /**
3441 * Validate the proposed container 'repeatable' on the
3442 * annotation type symbol 's'. Report errors at position
3443 * 'pos'.
3444 *
3445 * @param s The (annotation)type declaration annotated with a @Repeatable
3446 * @param repeatable the @Repeatable on 's'
3447 * @param pos where to report errors
3448 */
3449 public void validateRepeatable(TypeSymbol s, Attribute.Compound repeatable, DiagnosticPosition pos) {
3450 Assert.check(types.isSameType(repeatable.type, syms.repeatableType));
3451
3452 Type t = null;
3453 List<Pair<MethodSymbol,Attribute>> l = repeatable.values;
3454 if (!l.isEmpty()) {
3455 Assert.check(l.head.fst.name == names.value);
3456 if (l.head.snd instanceof Attribute.Class) {
3457 t = ((Attribute.Class)l.head.snd).getValue();
3458 }
3459 }
3460
3461 if (t == null) {
3462 // errors should already have been reported during Annotate
3463 return;
3464 }
3465
3466 validateValue(t.tsym, s, pos);
3467 validateRetention(t.tsym, s, pos);
3468 validateDocumented(t.tsym, s, pos);
3469 validateInherited(t.tsym, s, pos);
3470 validateTarget(t.tsym, s, pos);
3471 validateDefault(t.tsym, pos);
3472 }
3473
3474 private void validateValue(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3475 Symbol sym = container.members().findFirst(names.value);
3476 if (sym != null && sym.kind == MTH) {
3477 MethodSymbol m = (MethodSymbol) sym;
3478 Type ret = m.getReturnType();
3479 if (!(ret.hasTag(ARRAY) && types.isSameType(((ArrayType)ret).elemtype, contained.type))) {
3480 log.error(pos,
3481 Errors.InvalidRepeatableAnnotationValueReturn(container,
3482 ret,
3483 types.makeArrayType(contained.type)));
3484 }
3485 } else {
3486 log.error(pos, Errors.InvalidRepeatableAnnotationNoValue(container));
3487 }
3488 }
3489
3490 private void validateRetention(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3491 Attribute.RetentionPolicy containerRetention = types.getRetention(container);
3492 Attribute.RetentionPolicy containedRetention = types.getRetention(contained);
3493
3494 boolean error = false;
3495 switch (containedRetention) {
3496 case RUNTIME:
3497 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) {
3498 error = true;
3499 }
3500 break;
3501 case CLASS:
3502 if (containerRetention == Attribute.RetentionPolicy.SOURCE) {
3503 error = true;
3504 }
3505 }
3506 if (error ) {
3507 log.error(pos,
3508 Errors.InvalidRepeatableAnnotationRetention(container,
3509 containerRetention.name(),
3510 contained,
3511 containedRetention.name()));
3512 }
3513 }
3514
3515 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) {
3516 if (contained.attribute(syms.documentedType.tsym) != null) {
3517 if (container.attribute(syms.documentedType.tsym) == null) {
3518 log.error(pos, Errors.InvalidRepeatableAnnotationNotDocumented(container, contained));
3519 }
3520 }
3521 }
3522
3523 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) {
3524 if (contained.attribute(syms.inheritedType.tsym) != null) {
3525 if (container.attribute(syms.inheritedType.tsym) == null) {
3526 log.error(pos, Errors.InvalidRepeatableAnnotationNotInherited(container, contained));
3527 }
3528 }
3529 }
3530
3531 private void validateTarget(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3532 // The set of targets the container is applicable to must be a subset
3533 // (with respect to annotation target semantics) of the set of targets
3534 // the contained is applicable to. The target sets may be implicit or
3535 // explicit.
3536
3537 Set<Name> containerTargets;
3538 Attribute.Array containerTarget = getAttributeTargetAttribute(container);
3539 if (containerTarget == null) {
3540 containerTargets = getDefaultTargetSet();
3541 } else {
3542 containerTargets = new HashSet<>();
3543 for (Attribute app : containerTarget.values) {
3544 if (!(app instanceof Attribute.Enum attributeEnum)) {
3545 continue; // recovery
3546 }
3547 containerTargets.add(attributeEnum.value.name);
3548 }
3549 }
3550
3551 Set<Name> containedTargets;
3552 Attribute.Array containedTarget = getAttributeTargetAttribute(contained);
3553 if (containedTarget == null) {
3554 containedTargets = getDefaultTargetSet();
3555 } else {
3556 containedTargets = new HashSet<>();
3557 for (Attribute app : containedTarget.values) {
3558 if (!(app instanceof Attribute.Enum attributeEnum)) {
3559 continue; // recovery
3560 }
3561 containedTargets.add(attributeEnum.value.name);
3562 }
3563 }
3564
3565 if (!isTargetSubsetOf(containerTargets, containedTargets)) {
3566 log.error(pos, Errors.InvalidRepeatableAnnotationIncompatibleTarget(container, contained));
3567 }
3568 }
3569
3570 /* get a set of names for the default target */
3571 private Set<Name> getDefaultTargetSet() {
3572 if (defaultTargets == null) {
3573 defaultTargets = Set.of(defaultTargetMetaInfo());
3574 }
3575
3576 return defaultTargets;
3577 }
3578 private Set<Name> defaultTargets;
3579
3580
3581 /** Checks that s is a subset of t, with respect to ElementType
3582 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE},
3583 * and {TYPE_USE} covers the set {ANNOTATION_TYPE, TYPE, TYPE_USE,
3584 * TYPE_PARAMETER}.
3585 */
3586 private boolean isTargetSubsetOf(Set<Name> s, Set<Name> t) {
3587 // Check that all elements in s are present in t
3588 for (Name n2 : s) {
3589 boolean currentElementOk = false;
3590 for (Name n1 : t) {
3591 if (n1 == n2) {
3592 currentElementOk = true;
3593 break;
3594 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) {
3595 currentElementOk = true;
3596 break;
3597 } else if (n1 == names.TYPE_USE &&
3598 (n2 == names.TYPE ||
3599 n2 == names.ANNOTATION_TYPE ||
3600 n2 == names.TYPE_PARAMETER)) {
3601 currentElementOk = true;
3602 break;
3603 }
3604 }
3605 if (!currentElementOk)
3606 return false;
3607 }
3608 return true;
3609 }
3610
3611 private void validateDefault(Symbol container, DiagnosticPosition pos) {
3612 // validate that all other elements of containing type has defaults
3613 Scope scope = container.members();
3614 for(Symbol elm : scope.getSymbols()) {
3615 if (elm.name != names.value &&
3616 elm.kind == MTH &&
3617 ((MethodSymbol)elm).defaultValue == null) {
3618 log.error(pos,
3619 Errors.InvalidRepeatableAnnotationElemNondefault(container, elm));
3620 }
3621 }
3622 }
3623
3624 /** Is s a method symbol that overrides a method in a superclass? */
3625 boolean isOverrider(Symbol s) {
3626 if (s.kind != MTH || s.isStatic())
3627 return false;
3628 MethodSymbol m = (MethodSymbol)s;
3629 TypeSymbol owner = (TypeSymbol)m.owner;
3630 for (Type sup : types.closure(owner.type)) {
3631 if (sup == owner.type)
3632 continue; // skip "this"
3633 Scope scope = sup.tsym.members();
3634 for (Symbol sym : scope.getSymbolsByName(m.name)) {
3635 if (!sym.isStatic() && m.overrides(sym, owner, types, true))
3636 return true;
3637 }
3638 }
3639 return false;
3640 }
3641
3642 /** Is the annotation applicable to types? */
3643 protected boolean isTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
3644 List<Attribute> targets = typeAnnotations.annotationTargets(a.annotationType.type.tsym);
3645 return (targets == null) ?
3646 (Feature.NO_TARGET_ANNOTATION_APPLICABILITY.allowedInSource(source) && isTypeParameter) :
3647 targets.stream()
3648 .anyMatch(attr -> isTypeAnnotation(attr, isTypeParameter));
3649 }
3650 //where
3651 boolean isTypeAnnotation(Attribute a, boolean isTypeParameter) {
3652 Attribute.Enum e = (Attribute.Enum)a;
3653 return (e.value.name == names.TYPE_USE ||
3654 (isTypeParameter && e.value.name == names.TYPE_PARAMETER));
3655 }
3656
3657 /** Is the annotation applicable to the symbol? */
3658 Name[] getTargetNames(JCAnnotation a) {
3659 return getTargetNames(a.annotationType.type.tsym);
3660 }
3661
3662 public Name[] getTargetNames(TypeSymbol annoSym) {
3663 Attribute.Array arr = getAttributeTargetAttribute(annoSym);
3664 Name[] targets;
3665 if (arr == null) {
3666 targets = defaultTargetMetaInfo();
3667 } else {
3668 // TODO: can we optimize this?
3669 targets = new Name[arr.values.length];
3670 for (int i=0; i<arr.values.length; ++i) {
3671 Attribute app = arr.values[i];
3672 if (!(app instanceof Attribute.Enum attributeEnum)) {
3673 return new Name[0];
3674 }
3675 targets[i] = attributeEnum.value.name;
3676 }
3677 }
3678 return targets;
3679 }
3680
3681 boolean annotationApplicable(JCAnnotation a, Symbol s) {
3682 Optional<Set<Name>> targets = getApplicableTargets(a, s);
3683 /* the optional could be empty if the annotation is unknown in that case
3684 * we return that it is applicable and if it is erroneous that should imply
3685 * an error at the declaration site
3686 */
3687 return targets.isEmpty() || targets.isPresent() && !targets.get().isEmpty();
3688 }
3689
3690 Optional<Set<Name>> getApplicableTargets(JCAnnotation a, Symbol s) {
3691 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym);
3692 Name[] targets;
3693 Set<Name> applicableTargets = new HashSet<>();
3694
3695 if (arr == null) {
3696 targets = defaultTargetMetaInfo();
3697 } else {
3698 // TODO: can we optimize this?
3699 targets = new Name[arr.values.length];
3700 for (int i=0; i<arr.values.length; ++i) {
3701 Attribute app = arr.values[i];
3702 if (!(app instanceof Attribute.Enum attributeEnum)) {
3703 // recovery
3704 return Optional.empty();
3705 }
3706 targets[i] = attributeEnum.value.name;
3707 }
3708 }
3709 for (Name target : targets) {
3710 if (target == names.TYPE) {
3711 if (s.kind == TYP)
3712 applicableTargets.add(names.TYPE);
3713 } else if (target == names.FIELD) {
3714 if (s.kind == VAR && s.owner.kind != MTH)
3715 applicableTargets.add(names.FIELD);
3716 } else if (target == names.RECORD_COMPONENT) {
3717 if (s.getKind() == ElementKind.RECORD_COMPONENT) {
3718 applicableTargets.add(names.RECORD_COMPONENT);
3719 }
3720 } else if (target == names.METHOD) {
3721 if (s.kind == MTH && !s.isConstructor())
3722 applicableTargets.add(names.METHOD);
3723 } else if (target == names.PARAMETER) {
3724 if (s.kind == VAR &&
3725 (s.owner.kind == MTH && (s.flags() & PARAMETER) != 0)) {
3726 applicableTargets.add(names.PARAMETER);
3727 }
3728 } else if (target == names.CONSTRUCTOR) {
3729 if (s.kind == MTH && s.isConstructor())
3730 applicableTargets.add(names.CONSTRUCTOR);
3731 } else if (target == names.LOCAL_VARIABLE) {
3732 if (s.kind == VAR && s.owner.kind == MTH &&
3733 (s.flags() & PARAMETER) == 0) {
3734 applicableTargets.add(names.LOCAL_VARIABLE);
3735 }
3736 } else if (target == names.ANNOTATION_TYPE) {
3737 if (s.kind == TYP && (s.flags() & ANNOTATION) != 0) {
3738 applicableTargets.add(names.ANNOTATION_TYPE);
3739 }
3740 } else if (target == names.PACKAGE) {
3741 if (s.kind == PCK)
3742 applicableTargets.add(names.PACKAGE);
3743 } else if (target == names.TYPE_USE) {
3744 if (s.kind == VAR && s.owner.kind == MTH && s.type.hasTag(NONE)) {
3745 //cannot type annotate implicitly typed locals
3746 continue;
3747 } else if (s.kind == TYP || s.kind == VAR ||
3748 (s.kind == MTH && !s.isConstructor() &&
3749 !s.type.getReturnType().hasTag(VOID)) ||
3750 (s.kind == MTH && s.isConstructor())) {
3751 applicableTargets.add(names.TYPE_USE);
3752 }
3753 } else if (target == names.TYPE_PARAMETER) {
3754 if (s.kind == TYP && s.type.hasTag(TYPEVAR))
3755 applicableTargets.add(names.TYPE_PARAMETER);
3756 } else if (target == names.MODULE) {
3757 if (s.kind == MDL)
3758 applicableTargets.add(names.MODULE);
3759 } else {
3760 log.error(a, Errors.AnnotationUnrecognizedAttributeName(a.type, target));
3761 return Optional.empty(); // Unknown ElementType
3762 }
3763 }
3764 return Optional.of(applicableTargets);
3765 }
3766
3767 Attribute.Array getAttributeTargetAttribute(TypeSymbol s) {
3768 Attribute.Compound atTarget = s.getAnnotationTypeMetadata().getTarget();
3769 if (atTarget == null) return null; // ok, is applicable
3770 Attribute atValue = atTarget.member(names.value);
3771 return (atValue instanceof Attribute.Array attributeArray) ? attributeArray : null;
3772 }
3773
3774 private Name[] dfltTargetMeta;
3775 private Name[] defaultTargetMetaInfo() {
3776 if (dfltTargetMeta == null) {
3777 ArrayList<Name> defaultTargets = new ArrayList<>();
3778 defaultTargets.add(names.PACKAGE);
3779 defaultTargets.add(names.TYPE);
3780 defaultTargets.add(names.FIELD);
3781 defaultTargets.add(names.METHOD);
3782 defaultTargets.add(names.CONSTRUCTOR);
3783 defaultTargets.add(names.ANNOTATION_TYPE);
3784 defaultTargets.add(names.LOCAL_VARIABLE);
3785 defaultTargets.add(names.PARAMETER);
3786 if (allowRecords) {
3787 defaultTargets.add(names.RECORD_COMPONENT);
3788 }
3789 if (allowModules) {
3790 defaultTargets.add(names.MODULE);
3791 }
3792 dfltTargetMeta = defaultTargets.toArray(new Name[0]);
3793 }
3794 return dfltTargetMeta;
3795 }
3796
3797 /** Check an annotation value.
3798 *
3799 * @param a The annotation tree to check
3800 * @return true if this annotation tree is valid, otherwise false
3801 */
3802 public boolean validateAnnotationDeferErrors(JCAnnotation a) {
3803 boolean res = false;
3804 final Log.DiagnosticHandler diagHandler = new Log.DiscardDiagnosticHandler(log);
3805 try {
3806 res = validateAnnotation(a);
3807 } finally {
3808 log.popDiagnosticHandler(diagHandler);
3809 }
3810 return res;
3811 }
3812
3813 private boolean validateAnnotation(JCAnnotation a) {
3814 boolean isValid = true;
3815 AnnotationTypeMetadata metadata = a.annotationType.type.tsym.getAnnotationTypeMetadata();
3816
3817 // collect an inventory of the annotation elements
3818 Set<MethodSymbol> elements = metadata.getAnnotationElements();
3819
3820 // remove the ones that are assigned values
3821 for (JCTree arg : a.args) {
3822 if (!arg.hasTag(ASSIGN)) continue; // recovery
3823 JCAssign assign = (JCAssign)arg;
3824 Symbol m = TreeInfo.symbol(assign.lhs);
3825 if (m == null || m.type.isErroneous()) continue;
3826 if (!elements.remove(m)) {
3827 isValid = false;
3828 log.error(assign.lhs.pos(),
3829 Errors.DuplicateAnnotationMemberValue(m.name, a.type));
3830 }
3831 }
3832
3833 // all the remaining ones better have default values
3834 List<Name> missingDefaults = List.nil();
3835 Set<MethodSymbol> membersWithDefault = metadata.getAnnotationElementsWithDefault();
3836 for (MethodSymbol m : elements) {
3837 if (m.type.isErroneous())
3838 continue;
3839
3840 if (!membersWithDefault.contains(m))
3841 missingDefaults = missingDefaults.append(m.name);
3842 }
3843 missingDefaults = missingDefaults.reverse();
3844 if (missingDefaults.nonEmpty()) {
3845 isValid = false;
3846 Error errorKey = (missingDefaults.size() > 1)
3847 ? Errors.AnnotationMissingDefaultValue1(a.type, missingDefaults)
3848 : Errors.AnnotationMissingDefaultValue(a.type, missingDefaults);
3849 log.error(a.pos(), errorKey);
3850 }
3851
3852 return isValid && validateTargetAnnotationValue(a);
3853 }
3854
3855 /* Validate the special java.lang.annotation.Target annotation */
3856 boolean validateTargetAnnotationValue(JCAnnotation a) {
3857 // special case: java.lang.annotation.Target must not have
3858 // repeated values in its value member
3859 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
3860 a.args.tail == null)
3861 return true;
3862
3863 boolean isValid = true;
3864 if (!a.args.head.hasTag(ASSIGN)) return false; // error recovery
3865 JCAssign assign = (JCAssign) a.args.head;
3866 Symbol m = TreeInfo.symbol(assign.lhs);
3867 if (m.name != names.value) return false;
3868 JCTree rhs = assign.rhs;
3869 if (!rhs.hasTag(NEWARRAY)) return false;
3870 JCNewArray na = (JCNewArray) rhs;
3871 Set<Symbol> targets = new HashSet<>();
3872 for (JCTree elem : na.elems) {
3873 if (!targets.add(TreeInfo.symbol(elem))) {
3874 isValid = false;
3875 log.error(elem.pos(), Errors.RepeatedAnnotationTarget);
3876 }
3877 }
3878 return isValid;
3879 }
3880
3881 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
3882 if (lint.isEnabled(LintCategory.DEP_ANN) && s.isDeprecatableViaAnnotation() &&
3883 (s.flags() & DEPRECATED) != 0 &&
3884 !syms.deprecatedType.isErroneous() &&
3885 s.attribute(syms.deprecatedType.tsym) == null) {
3886 log.warning(LintCategory.DEP_ANN,
3887 pos, Warnings.MissingDeprecatedAnnotation);
3888 }
3889 // Note: @Deprecated has no effect on local variables, parameters and package decls.
3890 if (lint.isEnabled(LintCategory.DEPRECATION) && !s.isDeprecatableViaAnnotation()) {
3891 if (!syms.deprecatedType.isErroneous() && s.attribute(syms.deprecatedType.tsym) != null) {
3892 log.warning(LintCategory.DEPRECATION, pos,
3893 Warnings.DeprecatedAnnotationHasNoEffect(Kinds.kindName(s)));
3894 }
3895 }
3896 }
3897
3898 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
3899 checkDeprecated(() -> pos, other, s);
3900 }
3901
3902 void checkDeprecated(Supplier<DiagnosticPosition> pos, final Symbol other, final Symbol s) {
3903 if ( (s.isDeprecatedForRemoval()
3904 || s.isDeprecated() && !other.isDeprecated())
3905 && (s.outermostClass() != other.outermostClass() || s.outermostClass() == null)
3906 && s.kind != Kind.PCK) {
3907 deferredLintHandler.report(() -> warnDeprecated(pos.get(), s));
3908 }
3909 }
3910
3911 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
3912 if ((s.flags() & PROPRIETARY) != 0) {
3913 deferredLintHandler.report(() -> {
3914 log.mandatoryWarning(pos, Warnings.SunProprietary(s));
3915 });
3916 }
3917 }
3918
3919 void checkProfile(final DiagnosticPosition pos, final Symbol s) {
3920 if (profile != Profile.DEFAULT && (s.flags() & NOT_IN_PROFILE) != 0) {
3921 log.error(pos, Errors.NotInProfile(s, profile));
3922 }
3923 }
3924
3925 void checkPreview(DiagnosticPosition pos, Symbol other, Symbol s) {
3926 if ((s.flags() & PREVIEW_API) != 0 && !preview.participatesInPreview(syms, other, s) && !disablePreviewCheck) {
3927 if ((s.flags() & PREVIEW_REFLECTIVE) == 0) {
3928 if (!preview.isEnabled()) {
3929 log.error(pos, Errors.IsPreview(s));
3930 } else {
3931 preview.markUsesPreview(pos);
3932 deferredLintHandler.report(() -> warnPreviewAPI(pos, Warnings.IsPreview(s)));
3933 }
3934 } else {
3935 deferredLintHandler.report(() -> warnPreviewAPI(pos, Warnings.IsPreviewReflective(s)));
3936 }
3937 }
3938 if (preview.declaredUsingPreviewFeature(s)) {
3939 if (preview.isEnabled()) {
3940 //for preview disabled do presumably so not need to do anything?
3941 //If "s" is compiled from source, then there was an error for it already;
3942 //if "s" is from classfile, there already was an error for the classfile.
3943 preview.markUsesPreview(pos);
3944 deferredLintHandler.report(() -> warnDeclaredUsingPreview(pos, s));
3945 }
3946 }
3947 }
3948
3949 void checkRestricted(DiagnosticPosition pos, Symbol s) {
3950 if (s.kind == MTH && (s.flags() & RESTRICTED) != 0) {
3951 deferredLintHandler.report(() -> warnRestrictedAPI(pos, s));
3952 }
3953 }
3954
3955 /* *************************************************************************
3956 * Check for recursive annotation elements.
3957 **************************************************************************/
3958
3959 /** Check for cycles in the graph of annotation elements.
3960 */
3961 void checkNonCyclicElements(JCClassDecl tree) {
3962 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
3963 Assert.check((tree.sym.flags_field & LOCKED) == 0);
3964 try {
3965 tree.sym.flags_field |= LOCKED;
3966 for (JCTree def : tree.defs) {
3967 if (!def.hasTag(METHODDEF)) continue;
3968 JCMethodDecl meth = (JCMethodDecl)def;
3969 checkAnnotationResType(meth.pos(), meth.restype.type);
3970 }
3971 } finally {
3972 tree.sym.flags_field &= ~LOCKED;
3973 tree.sym.flags_field |= ACYCLIC_ANN;
3974 }
3975 }
3976
3977 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
3978 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
3979 return;
3980 if ((tsym.flags_field & LOCKED) != 0) {
3981 log.error(pos, Errors.CyclicAnnotationElement(tsym));
3982 return;
3983 }
3984 try {
3985 tsym.flags_field |= LOCKED;
3986 for (Symbol s : tsym.members().getSymbols(NON_RECURSIVE)) {
3987 if (s.kind != MTH)
3988 continue;
3989 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
3990 }
3991 } finally {
3992 tsym.flags_field &= ~LOCKED;
3993 tsym.flags_field |= ACYCLIC_ANN;
3994 }
3995 }
3996
3997 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
3998 switch (type.getTag()) {
3999 case CLASS:
4000 if ((type.tsym.flags() & ANNOTATION) != 0)
4001 checkNonCyclicElementsInternal(pos, type.tsym);
4002 break;
4003 case ARRAY:
4004 checkAnnotationResType(pos, types.elemtype(type));
4005 break;
4006 default:
4007 break; // int etc
4008 }
4009 }
4010
4011 /* *************************************************************************
4012 * Check for cycles in the constructor call graph.
4013 **************************************************************************/
4014
4015 /** Check for cycles in the graph of constructors calling other
4016 * constructors.
4017 */
4018 void checkCyclicConstructors(JCClassDecl tree) {
4019 // use LinkedHashMap so we generate errors deterministically
4020 Map<Symbol,Symbol> callMap = new LinkedHashMap<>();
4021
4022 // enter each constructor this-call into the map
4023 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
4024 if (!TreeInfo.isConstructor(l.head))
4025 continue;
4026 JCMethodDecl meth = (JCMethodDecl)l.head;
4027 JCMethodInvocation app = TreeInfo.findConstructorCall(meth);
4028 if (app != null && TreeInfo.name(app.meth) == names._this) {
4029 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
4030 } else {
4031 meth.sym.flags_field |= ACYCLIC;
4032 }
4033 }
4034
4035 // Check for cycles in the map
4036 Symbol[] ctors = new Symbol[0];
4037 ctors = callMap.keySet().toArray(ctors);
4038 for (Symbol caller : ctors) {
4039 checkCyclicConstructor(tree, caller, callMap);
4040 }
4041 }
4042
4043 /** Look in the map to see if the given constructor is part of a
4044 * call cycle.
4045 */
4046 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
4047 Map<Symbol,Symbol> callMap) {
4048 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
4049 if ((ctor.flags_field & LOCKED) != 0) {
4050 log.error(TreeInfo.diagnosticPositionFor(ctor, tree, false, t -> t.hasTag(IDENT)),
4051 Errors.RecursiveCtorInvocation);
4052 } else {
4053 ctor.flags_field |= LOCKED;
4054 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
4055 ctor.flags_field &= ~LOCKED;
4056 }
4057 ctor.flags_field |= ACYCLIC;
4058 }
4059 }
4060
4061 /* *************************************************************************
4062 * Verify the proper placement of super()/this() calls.
4063 *
4064 * - super()/this() may only appear in constructors
4065 * - There must be at most one super()/this() call per constructor
4066 * - The super()/this() call, if any, must be a top-level statement in the
4067 * constructor, i.e., not nested inside any other statement or block
4068 * - There must be no return statements prior to the super()/this() call
4069 **************************************************************************/
4070
4071 void checkSuperInitCalls(JCClassDecl tree) {
4072 new SuperThisChecker().check(tree);
4073 }
4074
4075 private class SuperThisChecker extends TreeScanner {
4076
4077 // Match this scan stack: 1=JCMethodDecl, 2=JCExpressionStatement, 3=JCMethodInvocation
4078 private static final int MATCH_SCAN_DEPTH = 3;
4079
4080 private boolean constructor; // is this method a constructor?
4081 private boolean firstStatement; // at the first statement in method?
4082 private JCReturn earlyReturn; // first return prior to the super()/init(), if any
4083 private Name initCall; // whichever of "super" or "init" we've seen already
4084 private int scanDepth; // current scan recursion depth in method body
4085
4086 public void check(JCClassDecl classDef) {
4087 scan(classDef.defs);
4088 }
4089
4090 @Override
4091 public void visitMethodDef(JCMethodDecl tree) {
4092 Assert.check(!constructor);
4093 Assert.check(earlyReturn == null);
4094 Assert.check(initCall == null);
4095 Assert.check(scanDepth == 1);
4096
4097 // Initialize state for this method
4098 constructor = TreeInfo.isConstructor(tree);
4099 try {
4100
4101 // Scan method body
4102 if (tree.body != null) {
4103 firstStatement = true;
4104 for (List<JCStatement> l = tree.body.stats; l.nonEmpty(); l = l.tail) {
4105 scan(l.head);
4106 firstStatement = false;
4107 }
4108 }
4109
4110 // Verify no 'return' seen prior to an explicit super()/this() call
4111 if (constructor && earlyReturn != null && initCall != null)
4112 log.error(earlyReturn.pos(), Errors.ReturnBeforeSuperclassInitialized);
4113 } finally {
4114 firstStatement = false;
4115 constructor = false;
4116 earlyReturn = null;
4117 initCall = null;
4118 }
4119 }
4120
4121 @Override
4122 public void scan(JCTree tree) {
4123 scanDepth++;
4124 try {
4125 super.scan(tree);
4126 } finally {
4127 scanDepth--;
4128 }
4129 }
4130
4131 @Override
4132 public void visitApply(JCMethodInvocation apply) {
4133 do {
4134
4135 // Is this a super() or this() call?
4136 Name methodName = TreeInfo.name(apply.meth);
4137 if (methodName != names._super && methodName != names._this)
4138 break;
4139
4140 // super()/this() calls must only appear in a constructor
4141 if (!constructor) {
4142 log.error(apply.pos(), Errors.CallMustOnlyAppearInCtor);
4143 break;
4144 }
4145
4146 // super()/this() calls must be a top level statement
4147 if (scanDepth != MATCH_SCAN_DEPTH) {
4148 log.error(apply.pos(), Errors.CtorCallsNotAllowedHere);
4149 break;
4150 }
4151
4152 // super()/this() calls must not appear more than once
4153 if (initCall != null) {
4154 log.error(apply.pos(), Errors.RedundantSuperclassInit);
4155 break;
4156 }
4157
4158 // valhalla is using this feature so commenting this code for now so that the
4159 // build doesn't depend on preview code
4160 // If super()/this() isn't first, require "statements before super()" feature
4161 /*if (!firstStatement) {
4162 preview.checkSourceLevel(apply.pos(), Feature.SUPER_INIT);
4163 }*/
4164
4165 // We found a legitimate super()/this() call; remember it
4166 initCall = methodName;
4167 } while (false);
4168
4169 // Proceed
4170 super.visitApply(apply);
4171 }
4172
4173 @Override
4174 public void visitReturn(JCReturn tree) {
4175 if (constructor && initCall == null && earlyReturn == null)
4176 earlyReturn = tree; // we have seen a return but not (yet) a super()/this()
4177 super.visitReturn(tree);
4178 }
4179
4180 @Override
4181 public void visitClassDef(JCClassDecl tree) {
4182 // don't descend any further
4183 }
4184 }
4185
4186 /* *************************************************************************
4187 * Miscellaneous
4188 **************************************************************************/
4189
4190 /**
4191 * Check for division by integer constant zero
4192 * @param pos Position for error reporting.
4193 * @param operator The operator for the expression
4194 * @param operand The right hand operand for the expression
4195 */
4196 void checkDivZero(final DiagnosticPosition pos, Symbol operator, Type operand) {
4197 if (operand.constValue() != null
4198 && operand.getTag().isSubRangeOf(LONG)
4199 && ((Number) (operand.constValue())).longValue() == 0) {
4200 int opc = ((OperatorSymbol)operator).opcode;
4201 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
4202 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
4203 deferredLintHandler.report(() -> warnDivZero(pos));
4204 }
4205 }
4206 }
4207
4208 /**
4209 * Check for possible loss of precission
4210 * @param pos Position for error reporting.
4211 * @param found The computed type of the tree
4212 * @param req The computed type of the tree
4213 */
4214 void checkLossOfPrecision(final DiagnosticPosition pos, Type found, Type req) {
4215 if (found.isNumeric() && req.isNumeric() && !types.isAssignable(found, req)) {
4216 deferredLintHandler.report(() -> {
4217 if (lint.isEnabled(LintCategory.LOSSY_CONVERSIONS))
4218 log.warning(LintCategory.LOSSY_CONVERSIONS,
4219 pos, Warnings.PossibleLossOfPrecision(found, req));
4220 });
4221 }
4222 }
4223
4224 /**
4225 * Check for empty statements after if
4226 */
4227 void checkEmptyIf(JCIf tree) {
4228 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null &&
4229 lint.isEnabled(LintCategory.EMPTY))
4230 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), Warnings.EmptyIf);
4231 }
4232
4233 /** Check that symbol is unique in given scope.
4234 * @param pos Position for error reporting.
4235 * @param sym The symbol.
4236 * @param s The scope.
4237 */
4238 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
4239 if (sym.type.isErroneous())
4240 return true;
4241 if (sym.owner.name == names.any) return false;
4242 for (Symbol byName : s.getSymbolsByName(sym.name, NON_RECURSIVE)) {
4243 if (sym != byName &&
4244 (byName.flags() & CLASH) == 0 &&
4245 sym.kind == byName.kind &&
4246 sym.name != names.error &&
4247 (sym.kind != MTH ||
4248 types.hasSameArgs(sym.type, byName.type) ||
4249 types.hasSameArgs(types.erasure(sym.type), types.erasure(byName.type)))) {
4250 if ((sym.flags() & VARARGS) != (byName.flags() & VARARGS)) {
4251 sym.flags_field |= CLASH;
4252 varargsDuplicateError(pos, sym, byName);
4253 return true;
4254 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, byName.type, false)) {
4255 duplicateErasureError(pos, sym, byName);
4256 sym.flags_field |= CLASH;
4257 return true;
4258 } else if ((sym.flags() & MATCH_BINDING) != 0 &&
4259 (byName.flags() & MATCH_BINDING) != 0 &&
4260 (byName.flags() & MATCH_BINDING_TO_OUTER) == 0) {
4261 if (!sym.type.isErroneous()) {
4262 log.error(pos, Errors.MatchBindingExists);
4263 sym.flags_field |= CLASH;
4264 }
4265 return false;
4266 } else {
4267 duplicateError(pos, byName);
4268 return false;
4269 }
4270 }
4271 }
4272 return true;
4273 }
4274
4275 /** Report duplicate declaration error.
4276 */
4277 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
4278 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
4279 log.error(pos, Errors.NameClashSameErasure(sym1, sym2));
4280 }
4281 }
4282
4283 /**Check that types imported through the ordinary imports don't clash with types imported
4284 * by other (static or ordinary) imports. Note that two static imports may import two clashing
4285 * types without an error on the imports.
4286 * @param toplevel The toplevel tree for which the test should be performed.
4287 */
4288 void checkImportsUnique(JCCompilationUnit toplevel) {
4289 WriteableScope ordinallyImportedSoFar = WriteableScope.create(toplevel.packge);
4290 WriteableScope staticallyImportedSoFar = WriteableScope.create(toplevel.packge);
4291 WriteableScope topLevelScope = toplevel.toplevelScope;
4292
4293 for (JCTree def : toplevel.defs) {
4294 if (!def.hasTag(IMPORT))
4295 continue;
4296
4297 JCImport imp = (JCImport) def;
4298
4299 if (imp.importScope == null)
4300 continue;
4301
4302 for (Symbol sym : imp.importScope.getSymbols(sym -> sym.kind == TYP)) {
4303 if (imp.isStatic()) {
4304 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, true);
4305 staticallyImportedSoFar.enter(sym);
4306 } else {
4307 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, false);
4308 ordinallyImportedSoFar.enter(sym);
4309 }
4310 }
4311
4312 imp.importScope = null;
4313 }
4314 }
4315
4316 /** Check that single-type import is not already imported or top-level defined,
4317 * but make an exception for two single-type imports which denote the same type.
4318 * @param pos Position for error reporting.
4319 * @param ordinallyImportedSoFar A Scope containing types imported so far through
4320 * ordinary imports.
4321 * @param staticallyImportedSoFar A Scope containing types imported so far through
4322 * static imports.
4323 * @param topLevelScope The current file's top-level Scope
4324 * @param sym The symbol.
4325 * @param staticImport Whether or not this was a static import
4326 */
4327 private boolean checkUniqueImport(DiagnosticPosition pos, Scope ordinallyImportedSoFar,
4328 Scope staticallyImportedSoFar, Scope topLevelScope,
4329 Symbol sym, boolean staticImport) {
4330 Predicate<Symbol> duplicates = candidate -> candidate != sym && !candidate.type.isErroneous();
4331 Symbol ordinaryClashing = ordinallyImportedSoFar.findFirst(sym.name, duplicates);
4332 Symbol staticClashing = null;
4333 if (ordinaryClashing == null && !staticImport) {
4334 staticClashing = staticallyImportedSoFar.findFirst(sym.name, duplicates);
4335 }
4336 if (ordinaryClashing != null || staticClashing != null) {
4337 if (ordinaryClashing != null)
4338 log.error(pos, Errors.AlreadyDefinedSingleImport(ordinaryClashing));
4339 else
4340 log.error(pos, Errors.AlreadyDefinedStaticSingleImport(staticClashing));
4341 return false;
4342 }
4343 Symbol clashing = topLevelScope.findFirst(sym.name, duplicates);
4344 if (clashing != null) {
4345 log.error(pos, Errors.AlreadyDefinedThisUnit(clashing));
4346 return false;
4347 }
4348 return true;
4349 }
4350
4351 /** Check that a qualified name is in canonical form (for import decls).
4352 */
4353 public void checkCanonical(JCTree tree) {
4354 if (!isCanonical(tree))
4355 log.error(tree.pos(),
4356 Errors.ImportRequiresCanonical(TreeInfo.symbol(tree)));
4357 }
4358 // where
4359 private boolean isCanonical(JCTree tree) {
4360 while (tree.hasTag(SELECT)) {
4361 JCFieldAccess s = (JCFieldAccess) tree;
4362 if (s.sym.owner.getQualifiedName() != TreeInfo.symbol(s.selected).getQualifiedName())
4363 return false;
4364 tree = s.selected;
4365 }
4366 return true;
4367 }
4368
4369 /** Check that an auxiliary class is not accessed from any other file than its own.
4370 */
4371 void checkForBadAuxiliaryClassAccess(DiagnosticPosition pos, Env<AttrContext> env, ClassSymbol c) {
4372 if (lint.isEnabled(Lint.LintCategory.AUXILIARYCLASS) &&
4373 (c.flags() & AUXILIARY) != 0 &&
4374 rs.isAccessible(env, c) &&
4375 !fileManager.isSameFile(c.sourcefile, env.toplevel.sourcefile))
4376 {
4377 log.warning(pos,
4378 Warnings.AuxiliaryClassAccessedFromOutsideOfItsSourceFile(c, c.sourcefile));
4379 }
4380 }
4381
4382 /**
4383 * Check for a default constructor in an exported package.
4384 */
4385 void checkDefaultConstructor(ClassSymbol c, DiagnosticPosition pos) {
4386 if (lint.isEnabled(LintCategory.MISSING_EXPLICIT_CTOR) &&
4387 ((c.flags() & (ENUM | RECORD)) == 0) &&
4388 !c.isAnonymous() &&
4389 ((c.flags() & (PUBLIC | PROTECTED)) != 0) &&
4390 Feature.MODULES.allowedInSource(source)) {
4391 NestingKind nestingKind = c.getNestingKind();
4392 switch (nestingKind) {
4393 case ANONYMOUS,
4394 LOCAL -> {return;}
4395 case TOP_LEVEL -> {;} // No additional checks needed
4396 case MEMBER -> {
4397 // For nested member classes, all the enclosing
4398 // classes must be public or protected.
4399 Symbol owner = c.owner;
4400 while (owner != null && owner.kind == TYP) {
4401 if ((owner.flags() & (PUBLIC | PROTECTED)) == 0)
4402 return;
4403 owner = owner.owner;
4404 }
4405 }
4406 }
4407
4408 // Only check classes in named packages exported by its module
4409 PackageSymbol pkg = c.packge();
4410 if (!pkg.isUnnamed()) {
4411 ModuleSymbol modle = pkg.modle;
4412 for (ExportsDirective exportDir : modle.exports) {
4413 // Report warning only if the containing
4414 // package is unconditionally exported
4415 if (exportDir.packge.equals(pkg)) {
4416 if (exportDir.modules == null || exportDir.modules.isEmpty()) {
4417 // Warning may be suppressed by
4418 // annotations; check again for being
4419 // enabled in the deferred context.
4420 deferredLintHandler.report(() -> {
4421 if (lint.isEnabled(LintCategory.MISSING_EXPLICIT_CTOR))
4422 log.warning(LintCategory.MISSING_EXPLICIT_CTOR,
4423 pos, Warnings.MissingExplicitCtor(c, pkg, modle));
4424 });
4425 } else {
4426 return;
4427 }
4428 }
4429 }
4430 }
4431 }
4432 return;
4433 }
4434
4435 private class ConversionWarner extends Warner {
4436 final String uncheckedKey;
4437 final Type found;
4438 final Type expected;
4439 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
4440 super(pos);
4441 this.uncheckedKey = uncheckedKey;
4442 this.found = found;
4443 this.expected = expected;
4444 }
4445
4446 @Override
4447 public void warn(LintCategory lint) {
4448 boolean warned = this.warned;
4449 super.warn(lint);
4450 if (warned) return; // suppress redundant diagnostics
4451 switch (lint) {
4452 case UNCHECKED:
4453 Check.this.warnUnchecked(pos(), Warnings.ProbFoundReq(diags.fragment(uncheckedKey), found, expected));
4454 break;
4455 case VARARGS:
4456 if (method != null &&
4457 method.attribute(syms.trustMeType.tsym) != null &&
4458 isTrustMeAllowedOnMethod(method) &&
4459 !types.isReifiable(method.type.getParameterTypes().last())) {
4460 Check.this.warnUnsafeVararg(pos(), Warnings.VarargsUnsafeUseVarargsParam(method.params.last()));
4461 }
4462 break;
4463 default:
4464 throw new AssertionError("Unexpected lint: " + lint);
4465 }
4466 }
4467 }
4468
4469 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
4470 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
4471 }
4472
4473 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
4474 return new ConversionWarner(pos, "unchecked.assign", found, expected);
4475 }
4476
4477 public void checkFunctionalInterface(JCClassDecl tree, ClassSymbol cs) {
4478 Compound functionalType = cs.attribute(syms.functionalInterfaceType.tsym);
4479
4480 if (functionalType != null) {
4481 try {
4482 types.findDescriptorSymbol((TypeSymbol)cs);
4483 } catch (Types.FunctionDescriptorLookupError ex) {
4484 DiagnosticPosition pos = tree.pos();
4485 for (JCAnnotation a : tree.getModifiers().annotations) {
4486 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
4487 pos = a.pos();
4488 break;
4489 }
4490 }
4491 log.error(pos, Errors.BadFunctionalIntfAnno1(ex.getDiagnostic()));
4492 }
4493 }
4494 }
4495
4496 public void checkImportsResolvable(final JCCompilationUnit toplevel) {
4497 for (final JCImport imp : toplevel.getImports()) {
4498 if (!imp.staticImport || !imp.qualid.hasTag(SELECT))
4499 continue;
4500 final JCFieldAccess select = imp.qualid;
4501 final Symbol origin;
4502 if (select.name == names.asterisk || (origin = TreeInfo.symbol(select.selected)) == null || origin.kind != TYP)
4503 continue;
4504
4505 TypeSymbol site = (TypeSymbol) TreeInfo.symbol(select.selected);
4506 if (!checkTypeContainsImportableElement(site, site, toplevel.packge, select.name, new HashSet<Symbol>())) {
4507 log.error(imp.pos(),
4508 Errors.CantResolveLocation(KindName.STATIC,
4509 select.name,
4510 null,
4511 null,
4512 Fragments.Location(kindName(site),
4513 site,
4514 null)));
4515 }
4516 }
4517 }
4518
4519 // Check that packages imported are in scope (JLS 7.4.3, 6.3, 6.5.3.1, 6.5.3.2)
4520 public void checkImportedPackagesObservable(final JCCompilationUnit toplevel) {
4521 OUTER: for (JCImport imp : toplevel.getImports()) {
4522 if (!imp.staticImport && TreeInfo.name(imp.qualid) == names.asterisk) {
4523 TypeSymbol tsym = imp.qualid.selected.type.tsym;
4524 if (tsym.kind == PCK && tsym.members().isEmpty() &&
4525 !(Feature.IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES.allowedInSource(source) && tsym.exists())) {
4526 log.error(DiagnosticFlag.RESOLVE_ERROR, imp.pos, Errors.DoesntExist(tsym));
4527 }
4528 }
4529 }
4530 }
4531
4532 private boolean checkTypeContainsImportableElement(TypeSymbol tsym, TypeSymbol origin, PackageSymbol packge, Name name, Set<Symbol> processed) {
4533 if (tsym == null || !processed.add(tsym))
4534 return false;
4535
4536 // also search through inherited names
4537 if (checkTypeContainsImportableElement(types.supertype(tsym.type).tsym, origin, packge, name, processed))
4538 return true;
4539
4540 for (Type t : types.interfaces(tsym.type))
4541 if (checkTypeContainsImportableElement(t.tsym, origin, packge, name, processed))
4542 return true;
4543
4544 for (Symbol sym : tsym.members().getSymbolsByName(name)) {
4545 if (sym.isStatic() &&
4546 importAccessible(sym, packge) &&
4547 sym.isMemberOf(origin, types)) {
4548 return true;
4549 }
4550 }
4551
4552 return false;
4553 }
4554
4555 // is the sym accessible everywhere in packge?
4556 public boolean importAccessible(Symbol sym, PackageSymbol packge) {
4557 try {
4558 int flags = (int)(sym.flags() & AccessFlags);
4559 switch (flags) {
4560 default:
4561 case PUBLIC:
4562 return true;
4563 case PRIVATE:
4564 return false;
4565 case 0:
4566 case PROTECTED:
4567 return sym.packge() == packge;
4568 }
4569 } catch (ClassFinder.BadClassFile err) {
4570 throw err;
4571 } catch (CompletionFailure ex) {
4572 return false;
4573 }
4574 }
4575
4576 public Type checkProcessorType(JCExpression processor, Type resultType, Env<AttrContext> env) {
4577 Type processorType = processor.type;
4578 Type interfaceType = types.asSuper(processorType, syms.processorType.tsym);
4579
4580 if (interfaceType != null) {
4581 List<Type> typeArguments = interfaceType.getTypeArguments();
4582
4583 if (typeArguments.size() == 2) {
4584 resultType = typeArguments.head;
4585 } else {
4586 resultType = syms.objectType;
4587 }
4588 } else {
4589 log.error(DiagnosticFlag.RESOLVE_ERROR, processor.pos,
4590 Errors.NotAProcessorType(processorType.tsym));
4591 }
4592
4593 return resultType;
4594 }
4595
4596 public void checkLeaksNotAccessible(Env<AttrContext> env, JCClassDecl check) {
4597 JCCompilationUnit toplevel = env.toplevel;
4598
4599 if ( toplevel.modle == syms.unnamedModule
4600 || toplevel.modle == syms.noModule
4601 || (check.sym.flags() & COMPOUND) != 0) {
4602 return ;
4603 }
4604
4605 ExportsDirective currentExport = findExport(toplevel.packge);
4606
4607 if ( currentExport == null //not exported
4608 || currentExport.modules != null) //don't check classes in qualified export
4609 return ;
4610
4611 new TreeScanner() {
4612 Lint lint = env.info.lint;
4613 boolean inSuperType;
4614
4615 @Override
4616 public void visitBlock(JCBlock tree) {
4617 }
4618 @Override
4619 public void visitMethodDef(JCMethodDecl tree) {
4620 if (!isAPISymbol(tree.sym))
4621 return;
4622 Lint prevLint = lint;
4623 try {
4624 lint = lint.augment(tree.sym);
4625 if (lint.isEnabled(LintCategory.EXPORTS)) {
4626 super.visitMethodDef(tree);
4627 }
4628 } finally {
4629 lint = prevLint;
4630 }
4631 }
4632 @Override
4633 public void visitVarDef(JCVariableDecl tree) {
4634 if (!isAPISymbol(tree.sym) && tree.sym.owner.kind != MTH)
4635 return;
4636 Lint prevLint = lint;
4637 try {
4638 lint = lint.augment(tree.sym);
4639 if (lint.isEnabled(LintCategory.EXPORTS)) {
4640 scan(tree.mods);
4641 scan(tree.vartype);
4642 }
4643 } finally {
4644 lint = prevLint;
4645 }
4646 }
4647 @Override
4648 public void visitClassDef(JCClassDecl tree) {
4649 if (tree != check)
4650 return ;
4651
4652 if (!isAPISymbol(tree.sym))
4653 return ;
4654
4655 Lint prevLint = lint;
4656 try {
4657 lint = lint.augment(tree.sym);
4658 if (lint.isEnabled(LintCategory.EXPORTS)) {
4659 scan(tree.mods);
4660 scan(tree.typarams);
4661 try {
4662 inSuperType = true;
4663 scan(tree.extending);
4664 scan(tree.implementing);
4665 } finally {
4666 inSuperType = false;
4667 }
4668 scan(tree.defs);
4669 }
4670 } finally {
4671 lint = prevLint;
4672 }
4673 }
4674 @Override
4675 public void visitTypeApply(JCTypeApply tree) {
4676 scan(tree.clazz);
4677 boolean oldInSuperType = inSuperType;
4678 try {
4679 inSuperType = false;
4680 scan(tree.arguments);
4681 } finally {
4682 inSuperType = oldInSuperType;
4683 }
4684 }
4685 @Override
4686 public void visitIdent(JCIdent tree) {
4687 Symbol sym = TreeInfo.symbol(tree);
4688 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR)) {
4689 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4690 }
4691 }
4692
4693 @Override
4694 public void visitSelect(JCFieldAccess tree) {
4695 Symbol sym = TreeInfo.symbol(tree);
4696 Symbol sitesym = TreeInfo.symbol(tree.selected);
4697 if (sym.kind == TYP && sitesym.kind == PCK) {
4698 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4699 } else {
4700 super.visitSelect(tree);
4701 }
4702 }
4703
4704 @Override
4705 public void visitAnnotation(JCAnnotation tree) {
4706 if (tree.attribute.type.tsym.getAnnotation(java.lang.annotation.Documented.class) != null)
4707 super.visitAnnotation(tree);
4708 }
4709
4710 }.scan(check);
4711 }
4712 //where:
4713 private ExportsDirective findExport(PackageSymbol pack) {
4714 for (ExportsDirective d : pack.modle.exports) {
4715 if (d.packge == pack)
4716 return d;
4717 }
4718
4719 return null;
4720 }
4721 private boolean isAPISymbol(Symbol sym) {
4722 while (sym.kind != PCK) {
4723 if ((sym.flags() & Flags.PUBLIC) == 0 && (sym.flags() & Flags.PROTECTED) == 0) {
4724 return false;
4725 }
4726 sym = sym.owner;
4727 }
4728 return true;
4729 }
4730 private void checkVisible(DiagnosticPosition pos, Symbol what, PackageSymbol inPackage, boolean inSuperType) {
4731 if (!isAPISymbol(what) && !inSuperType) { //package private/private element
4732 log.warning(LintCategory.EXPORTS, pos, Warnings.LeaksNotAccessible(kindName(what), what, what.packge().modle));
4733 return ;
4734 }
4735
4736 PackageSymbol whatPackage = what.packge();
4737 ExportsDirective whatExport = findExport(whatPackage);
4738 ExportsDirective inExport = findExport(inPackage);
4739
4740 if (whatExport == null) { //package not exported:
4741 log.warning(LintCategory.EXPORTS, pos, Warnings.LeaksNotAccessibleUnexported(kindName(what), what, what.packge().modle));
4742 return ;
4743 }
4744
4745 if (whatExport.modules != null) {
4746 if (inExport.modules == null || !whatExport.modules.containsAll(inExport.modules)) {
4747 log.warning(LintCategory.EXPORTS, pos, Warnings.LeaksNotAccessibleUnexportedQualified(kindName(what), what, what.packge().modle));
4748 }
4749 }
4750
4751 if (whatPackage.modle != inPackage.modle && whatPackage.modle != syms.java_base) {
4752 //check that relativeTo.modle requires transitive what.modle, somehow:
4753 List<ModuleSymbol> todo = List.of(inPackage.modle);
4754
4755 while (todo.nonEmpty()) {
4756 ModuleSymbol current = todo.head;
4757 todo = todo.tail;
4758 if (current == whatPackage.modle)
4759 return ; //OK
4760 if ((current.flags() & Flags.AUTOMATIC_MODULE) != 0)
4761 continue; //for automatic modules, don't look into their dependencies
4762 for (RequiresDirective req : current.requires) {
4763 if (req.isTransitive()) {
4764 todo = todo.prepend(req.module);
4765 }
4766 }
4767 }
4768
4769 log.warning(LintCategory.EXPORTS, pos, Warnings.LeaksNotAccessibleNotRequiredTransitive(kindName(what), what, what.packge().modle));
4770 }
4771 }
4772
4773 void checkModuleExists(final DiagnosticPosition pos, ModuleSymbol msym) {
4774 if (msym.kind != MDL) {
4775 deferredLintHandler.report(() -> {
4776 if (lint.isEnabled(LintCategory.MODULE))
4777 log.warning(LintCategory.MODULE, pos, Warnings.ModuleNotFound(msym));
4778 });
4779 }
4780 }
4781
4782 void checkPackageExistsForOpens(final DiagnosticPosition pos, PackageSymbol packge) {
4783 if (packge.members().isEmpty() &&
4784 ((packge.flags() & Flags.HAS_RESOURCE) == 0)) {
4785 deferredLintHandler.report(() -> {
4786 if (lint.isEnabled(LintCategory.OPENS))
4787 log.warning(pos, Warnings.PackageEmptyOrNotFound(packge));
4788 });
4789 }
4790 }
4791
4792 void checkModuleRequires(final DiagnosticPosition pos, final RequiresDirective rd) {
4793 if ((rd.module.flags() & Flags.AUTOMATIC_MODULE) != 0) {
4794 deferredLintHandler.report(() -> {
4795 if (rd.isTransitive() && lint.isEnabled(LintCategory.REQUIRES_TRANSITIVE_AUTOMATIC)) {
4796 log.warning(pos, Warnings.RequiresTransitiveAutomatic);
4797 } else if (lint.isEnabled(LintCategory.REQUIRES_AUTOMATIC)) {
4798 log.warning(pos, Warnings.RequiresAutomatic);
4799 }
4800 });
4801 }
4802 }
4803
4804 /**
4805 * Verify the case labels conform to the constraints. Checks constraints related
4806 * combinations of patterns and other labels.
4807 *
4808 * @param cases the cases that should be checked.
4809 */
4810 void checkSwitchCaseStructure(List<JCCase> cases) {
4811 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4812 JCCase c = l.head;
4813 if (c.labels.head instanceof JCConstantCaseLabel constLabel) {
4814 if (TreeInfo.isNull(constLabel.expr)) {
4815 if (c.labels.tail.nonEmpty()) {
4816 if (c.labels.tail.head instanceof JCDefaultCaseLabel defLabel) {
4817 if (c.labels.tail.tail.nonEmpty()) {
4818 log.error(c.labels.tail.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4819 }
4820 } else {
4821 log.error(c.labels.tail.head.pos(), Errors.InvalidCaseLabelCombination);
4822 }
4823 }
4824 } else {
4825 for (JCCaseLabel label : c.labels.tail) {
4826 if (!(label instanceof JCConstantCaseLabel) || TreeInfo.isNullCaseLabel(label)) {
4827 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4828 break;
4829 }
4830 }
4831 }
4832 } else if (c.labels.tail.nonEmpty()) {
4833 var patterCaseLabels = c.labels.stream().filter(ll -> ll instanceof JCPatternCaseLabel).map(cl -> (JCPatternCaseLabel)cl);
4834 var allUnderscore = patterCaseLabels.allMatch(pcl -> !hasBindings(pcl.getPattern()));
4835
4836 if (!allUnderscore) {
4837 log.error(c.labels.tail.head.pos(), Errors.FlowsThroughFromPattern);
4838 }
4839
4840 boolean allPatternCaseLabels = c.labels.stream().allMatch(p -> p instanceof JCPatternCaseLabel);
4841
4842 if (allPatternCaseLabels) {
4843 preview.checkSourceLevel(c.labels.tail.head.pos(), Feature.UNNAMED_VARIABLES);
4844 }
4845
4846 for (JCCaseLabel label : c.labels.tail) {
4847 if (label instanceof JCConstantCaseLabel) {
4848 log.error(label.pos(), Errors.InvalidCaseLabelCombination);
4849 break;
4850 }
4851 }
4852 }
4853 }
4854
4855 boolean isCaseStatementGroup = cases.nonEmpty() &&
4856 cases.head.caseKind == CaseTree.CaseKind.STATEMENT;
4857
4858 if (isCaseStatementGroup) {
4859 boolean previousCompletessNormally = false;
4860 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4861 JCCase c = l.head;
4862 if (previousCompletessNormally &&
4863 c.stats.nonEmpty() &&
4864 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4865 (hasBindings(patternLabel.pat) || hasBindings(c.guard))) {
4866 log.error(c.labels.head.pos(), Errors.FlowsThroughToPattern);
4867 } else if (c.stats.isEmpty() &&
4868 c.labels.head instanceof JCPatternCaseLabel patternLabel &&
4869 (hasBindings(patternLabel.pat) || hasBindings(c.guard)) &&
4870 hasStatements(l.tail)) {
4871 log.error(c.labels.head.pos(), Errors.FlowsThroughFromPattern);
4872 }
4873 previousCompletessNormally = c.completesNormally;
4874 }
4875 }
4876 }
4877
4878 boolean hasBindings(JCTree p) {
4879 boolean[] bindings = new boolean[1];
4880
4881 new TreeScanner() {
4882 @Override
4883 public void visitBindingPattern(JCBindingPattern tree) {
4884 bindings[0] = !tree.var.sym.isUnnamedVariable();
4885 super.visitBindingPattern(tree);
4886 }
4887 }.scan(p);
4888
4889 return bindings[0];
4890 }
4891
4892 boolean hasStatements(List<JCCase> cases) {
4893 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4894 if (l.head.stats.nonEmpty()) {
4895 return true;
4896 }
4897 }
4898
4899 return false;
4900 }
4901 void checkSwitchCaseLabelDominated(List<JCCase> cases) {
4902 List<Pair<JCCase, JCCaseLabel>> caseLabels = List.nil();
4903 boolean seenDefault = false;
4904 boolean seenDefaultLabel = false;
4905 boolean warnDominatedByDefault = false;
4906 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4907 JCCase c = l.head;
4908 for (JCCaseLabel label : c.labels) {
4909 if (label.hasTag(DEFAULTCASELABEL)) {
4910 seenDefault = true;
4911 seenDefaultLabel |=
4912 TreeInfo.isNullCaseLabel(c.labels.head);
4913 continue;
4914 }
4915 if (TreeInfo.isNullCaseLabel(label)) {
4916 if (seenDefault) {
4917 log.error(label.pos(), Errors.PatternDominated);
4918 }
4919 continue;
4920 }
4921 if (seenDefault && !warnDominatedByDefault) {
4922 if (label.hasTag(PATTERNCASELABEL) ||
4923 (label instanceof JCConstantCaseLabel && seenDefaultLabel)) {
4924 log.error(label.pos(), Errors.PatternDominated);
4925 warnDominatedByDefault = true;
4926 }
4927 }
4928 Type currentType = labelType(label);
4929 for (Pair<JCCase, JCCaseLabel> caseAndLabel : caseLabels) {
4930 JCCase testCase = caseAndLabel.fst;
4931 JCCaseLabel testCaseLabel = caseAndLabel.snd;
4932 Type testType = labelType(testCaseLabel);
4933 if (types.isSubtype(currentType, testType) &&
4934 !currentType.hasTag(ERROR) && !testType.hasTag(ERROR)) {
4935 //the current label is potentially dominated by the existing (test) label, check:
4936 boolean dominated = false;
4937 if (label instanceof JCConstantCaseLabel) {
4938 dominated |= !(testCaseLabel instanceof JCConstantCaseLabel) &&
4939 TreeInfo.unguardedCase(testCase);
4940 } else if (label instanceof JCPatternCaseLabel patternCL &&
4941 testCaseLabel instanceof JCPatternCaseLabel testPatternCaseLabel &&
4942 (testCase.equals(c) || TreeInfo.unguardedCase(testCase))) {
4943 dominated = patternDominated(testPatternCaseLabel.pat,
4944 patternCL.pat);
4945 }
4946 if (dominated) {
4947 log.error(label.pos(), Errors.PatternDominated);
4948 }
4949 }
4950 }
4951 caseLabels = caseLabels.prepend(Pair.of(c, label));
4952 }
4953 }
4954 }
4955 //where:
4956 private Type labelType(JCCaseLabel label) {
4957 return types.erasure(switch (label.getTag()) {
4958 case PATTERNCASELABEL -> ((JCPatternCaseLabel) label).pat.type;
4959 case CONSTANTCASELABEL -> types.boxedTypeOrType(((JCConstantCaseLabel) label).expr.type);
4960 default -> throw Assert.error("Unexpected tree kind: " + label.getTag());
4961 });
4962 }
4963 private boolean patternDominated(JCPattern existingPattern, JCPattern currentPattern) {
4964 Type existingPatternType = types.erasure(existingPattern.type);
4965 Type currentPatternType = types.erasure(currentPattern.type);
4966 if (existingPatternType.isPrimitive() ^ currentPatternType.isPrimitive()) {
4967 return false;
4968 }
4969 if (existingPatternType.isPrimitive()) {
4970 return types.isSameType(existingPatternType, currentPatternType);
4971 } else {
4972 if (!types.isSubtype(currentPatternType, existingPatternType)) {
4973 return false;
4974 }
4975 }
4976 if (currentPattern instanceof JCBindingPattern ||
4977 currentPattern instanceof JCAnyPattern) {
4978 return existingPattern instanceof JCBindingPattern ||
4979 existingPattern instanceof JCAnyPattern;
4980 } else if (currentPattern instanceof JCRecordPattern currentRecordPattern) {
4981 if (existingPattern instanceof JCBindingPattern ||
4982 existingPattern instanceof JCAnyPattern) {
4983 return true;
4984 } else if (existingPattern instanceof JCRecordPattern existingRecordPattern) {
4985 List<JCPattern> existingNested = existingRecordPattern.nested;
4986 List<JCPattern> currentNested = currentRecordPattern.nested;
4987 if (existingNested.size() != currentNested.size()) {
4988 return false;
4989 }
4990 while (existingNested.nonEmpty()) {
4991 if (!patternDominated(existingNested.head, currentNested.head)) {
4992 return false;
4993 }
4994 existingNested = existingNested.tail;
4995 currentNested = currentNested.tail;
4996 }
4997 return true;
4998 } else {
4999 Assert.error("Unknown pattern: " + existingPattern.getTag());
5000 }
5001 } else {
5002 Assert.error("Unknown pattern: " + currentPattern.getTag());
5003 }
5004 return false;
5005 }
5006
5007 /** check if a type is a subtype of Externalizable, if that is available. */
5008 boolean isExternalizable(Type t) {
5009 try {
5010 syms.externalizableType.complete();
5011 } catch (CompletionFailure e) {
5012 return false;
5013 }
5014 return types.isSubtype(t, syms.externalizableType);
5015 }
5016
5017 /**
5018 * Check structure of serialization declarations.
5019 */
5020 public void checkSerialStructure(JCClassDecl tree, ClassSymbol c) {
5021 (new SerialTypeVisitor()).visit(c, tree);
5022 }
5023
5024 /**
5025 * This visitor will warn if a serialization-related field or
5026 * method is declared in a suspicious or incorrect way. In
5027 * particular, it will warn for cases where the runtime
5028 * serialization mechanism will silently ignore a mis-declared
5029 * entity.
5030 *
5031 * Distinguished serialization-related fields and methods:
5032 *
5033 * Methods:
5034 *
5035 * private void writeObject(ObjectOutputStream stream) throws IOException
5036 * ANY-ACCESS-MODIFIER Object writeReplace() throws ObjectStreamException
5037 *
5038 * private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException
5039 * private void readObjectNoData() throws ObjectStreamException
5040 * ANY-ACCESS-MODIFIER Object readResolve() throws ObjectStreamException
5041 *
5042 * Fields:
5043 *
5044 * private static final long serialVersionUID
5045 * private static final ObjectStreamField[] serialPersistentFields
5046 *
5047 * Externalizable: methods defined on the interface
5048 * public void writeExternal(ObjectOutput) throws IOException
5049 * public void readExternal(ObjectInput) throws IOException
5050 */
5051 private class SerialTypeVisitor extends ElementKindVisitor14<Void, JCClassDecl> {
5052 SerialTypeVisitor() {
5053 this.lint = Check.this.lint;
5054 }
5055
5056 private static final Set<String> serialMethodNames =
5057 Set.of("writeObject", "writeReplace",
5058 "readObject", "readObjectNoData",
5059 "readResolve");
5060
5061 private static final Set<String> serialFieldNames =
5062 Set.of("serialVersionUID", "serialPersistentFields");
5063
5064 // Type of serialPersistentFields
5065 private final Type OSF_TYPE = new Type.ArrayType(syms.objectStreamFieldType, syms.arrayClass);
5066
5067 Lint lint;
5068
5069 @Override
5070 public Void defaultAction(Element e, JCClassDecl p) {
5071 throw new IllegalArgumentException(Objects.requireNonNullElse(e.toString(), ""));
5072 }
5073
5074 @Override
5075 public Void visitType(TypeElement e, JCClassDecl p) {
5076 runUnderLint(e, p, (symbol, param) -> super.visitType(symbol, param));
5077 return null;
5078 }
5079
5080 @Override
5081 public Void visitTypeAsClass(TypeElement e,
5082 JCClassDecl p) {
5083 // Anonymous classes filtered out by caller.
5084
5085 ClassSymbol c = (ClassSymbol)e;
5086
5087 checkCtorAccess(p, c);
5088
5089 // Check for missing serialVersionUID; check *not* done
5090 // for enums or records.
5091 VarSymbol svuidSym = null;
5092 for (Symbol sym : c.members().getSymbolsByName(names.serialVersionUID)) {
5093 if (sym.kind == VAR) {
5094 svuidSym = (VarSymbol)sym;
5095 break;
5096 }
5097 }
5098
5099 if (svuidSym == null) {
5100 log.warning(LintCategory.SERIAL, p.pos(), Warnings.MissingSVUID(c));
5101 }
5102
5103 // Check for serialPersistentFields to gate checks for
5104 // non-serializable non-transient instance fields
5105 boolean serialPersistentFieldsPresent =
5106 c.members()
5107 .getSymbolsByName(names.serialPersistentFields, sym -> sym.kind == VAR)
5108 .iterator()
5109 .hasNext();
5110
5111 // Check declarations of serialization-related methods and
5112 // fields
5113 for(Symbol el : c.getEnclosedElements()) {
5114 runUnderLint(el, p, (enclosed, tree) -> {
5115 String name = null;
5116 switch(enclosed.getKind()) {
5117 case FIELD -> {
5118 if (!serialPersistentFieldsPresent) {
5119 var flags = enclosed.flags();
5120 if ( ((flags & TRANSIENT) == 0) &&
5121 ((flags & STATIC) == 0)) {
5122 Type varType = enclosed.asType();
5123 if (!canBeSerialized(varType)) {
5124 // Note per JLS arrays are
5125 // serializable even if the
5126 // component type is not.
5127 log.warning(LintCategory.SERIAL,
5128 TreeInfo.diagnosticPositionFor(enclosed, tree),
5129 Warnings.NonSerializableInstanceField);
5130 } else if (varType.hasTag(ARRAY)) {
5131 ArrayType arrayType = (ArrayType)varType;
5132 Type elementType = arrayType.elemtype;
5133 while (elementType.hasTag(ARRAY)) {
5134 arrayType = (ArrayType)elementType;
5135 elementType = arrayType.elemtype;
5136 }
5137 if (!canBeSerialized(elementType)) {
5138 log.warning(LintCategory.SERIAL,
5139 TreeInfo.diagnosticPositionFor(enclosed, tree),
5140 Warnings.NonSerializableInstanceFieldArray(elementType));
5141 }
5142 }
5143 }
5144 }
5145
5146 name = enclosed.getSimpleName().toString();
5147 if (serialFieldNames.contains(name)) {
5148 VarSymbol field = (VarSymbol)enclosed;
5149 switch (name) {
5150 case "serialVersionUID" -> checkSerialVersionUID(tree, e, field);
5151 case "serialPersistentFields" -> checkSerialPersistentFields(tree, e, field);
5152 default -> throw new AssertionError();
5153 }
5154 }
5155 }
5156
5157 // Correctly checking the serialization-related
5158 // methods is subtle. For the methods declared to be
5159 // private or directly declared in the class, the
5160 // enclosed elements of the class can be checked in
5161 // turn. However, writeReplace and readResolve can be
5162 // declared in a superclass and inherited. Note that
5163 // the runtime lookup walks the superclass chain
5164 // looking for writeReplace/readResolve via
5165 // Class.getDeclaredMethod. This differs from calling
5166 // Elements.getAllMembers(TypeElement) as the latter
5167 // will also pull in default methods from
5168 // superinterfaces. In other words, the runtime checks
5169 // (which long predate default methods on interfaces)
5170 // do not admit the possibility of inheriting methods
5171 // this way, a difference from general inheritance.
5172
5173 // The current implementation just checks the enclosed
5174 // elements and does not directly check the inherited
5175 // methods. If all the types are being checked this is
5176 // less of a concern; however, there are cases that
5177 // could be missed. In particular, readResolve and
5178 // writeReplace could, in principle, by inherited from
5179 // a non-serializable superclass and thus not checked
5180 // even if compiled with a serializable child class.
5181 case METHOD -> {
5182 var method = (MethodSymbol)enclosed;
5183 name = method.getSimpleName().toString();
5184 if (serialMethodNames.contains(name)) {
5185 switch (name) {
5186 case "writeObject" -> checkWriteObject(tree, e, method);
5187 case "writeReplace" -> checkWriteReplace(tree,e, method);
5188 case "readObject" -> checkReadObject(tree,e, method);
5189 case "readObjectNoData" -> checkReadObjectNoData(tree, e, method);
5190 case "readResolve" -> checkReadResolve(tree, e, method);
5191 default -> throw new AssertionError();
5192 }
5193 }
5194 }
5195 }
5196 });
5197 }
5198
5199 return null;
5200 }
5201
5202 boolean canBeSerialized(Type type) {
5203 return type.isPrimitive() || rs.isSerializable(type);
5204 }
5205
5206 /**
5207 * Check that Externalizable class needs a public no-arg
5208 * constructor.
5209 *
5210 * Check that a Serializable class has access to the no-arg
5211 * constructor of its first nonserializable superclass.
5212 */
5213 private void checkCtorAccess(JCClassDecl tree, ClassSymbol c) {
5214 if (isExternalizable(c.type)) {
5215 for(var sym : c.getEnclosedElements()) {
5216 if (sym.isConstructor() &&
5217 ((sym.flags() & PUBLIC) == PUBLIC)) {
5218 if (((MethodSymbol)sym).getParameters().isEmpty()) {
5219 return;
5220 }
5221 }
5222 }
5223 log.warning(LintCategory.SERIAL, tree.pos(),
5224 Warnings.ExternalizableMissingPublicNoArgCtor);
5225 } else {
5226 // Approximate access to the no-arg constructor up in
5227 // the superclass chain by checking that the
5228 // constructor is not private. This may not handle
5229 // some cross-package situations correctly.
5230 Type superClass = c.getSuperclass();
5231 // java.lang.Object is *not* Serializable so this loop
5232 // should terminate.
5233 while (rs.isSerializable(superClass) ) {
5234 try {
5235 superClass = (Type)((TypeElement)(((DeclaredType)superClass)).asElement()).getSuperclass();
5236 } catch(ClassCastException cce) {
5237 return ; // Don't try to recover
5238 }
5239 }
5240 // Non-Serializable superclass
5241 try {
5242 ClassSymbol supertype = ((ClassSymbol)(((DeclaredType)superClass).asElement()));
5243 for(var sym : supertype.getEnclosedElements()) {
5244 if (sym.isConstructor()) {
5245 MethodSymbol ctor = (MethodSymbol)sym;
5246 if (ctor.getParameters().isEmpty()) {
5247 if (((ctor.flags() & PRIVATE) == PRIVATE) ||
5248 // Handle nested classes and implicit this$0
5249 (supertype.getNestingKind() == NestingKind.MEMBER &&
5250 ((supertype.flags() & STATIC) == 0)))
5251 log.warning(LintCategory.SERIAL, tree.pos(),
5252 Warnings.SerializableMissingAccessNoArgCtor(supertype.getQualifiedName()));
5253 }
5254 }
5255 }
5256 } catch (ClassCastException cce) {
5257 return ; // Don't try to recover
5258 }
5259 return;
5260 }
5261 }
5262
5263 private void checkSerialVersionUID(JCClassDecl tree, Element e, VarSymbol svuid) {
5264 // To be effective, serialVersionUID must be marked static
5265 // and final, but private is recommended. But alas, in
5266 // practice there are many non-private serialVersionUID
5267 // fields.
5268 if ((svuid.flags() & (STATIC | FINAL)) !=
5269 (STATIC | FINAL)) {
5270 log.warning(LintCategory.SERIAL,
5271 TreeInfo.diagnosticPositionFor(svuid, tree),
5272 Warnings.ImproperSVUID((Symbol)e));
5273 }
5274
5275 // check svuid has type long
5276 if (!svuid.type.hasTag(LONG)) {
5277 log.warning(LintCategory.SERIAL,
5278 TreeInfo.diagnosticPositionFor(svuid, tree),
5279 Warnings.LongSVUID((Symbol)e));
5280 }
5281
5282 if (svuid.getConstValue() == null)
5283 log.warning(LintCategory.SERIAL,
5284 TreeInfo.diagnosticPositionFor(svuid, tree),
5285 Warnings.ConstantSVUID((Symbol)e));
5286 }
5287
5288 private void checkSerialPersistentFields(JCClassDecl tree, Element e, VarSymbol spf) {
5289 // To be effective, serialPersisentFields must be private, static, and final.
5290 if ((spf.flags() & (PRIVATE | STATIC | FINAL)) !=
5291 (PRIVATE | STATIC | FINAL)) {
5292 log.warning(LintCategory.SERIAL,
5293 TreeInfo.diagnosticPositionFor(spf, tree),
5294 Warnings.ImproperSPF);
5295 }
5296
5297 if (!types.isSameType(spf.type, OSF_TYPE)) {
5298 log.warning(LintCategory.SERIAL,
5299 TreeInfo.diagnosticPositionFor(spf, tree),
5300 Warnings.OSFArraySPF);
5301 }
5302
5303 if (isExternalizable((Type)(e.asType()))) {
5304 log.warning(LintCategory.SERIAL,
5305 TreeInfo.diagnosticPositionFor(spf, tree),
5306 Warnings.IneffectualSerialFieldExternalizable);
5307 }
5308
5309 // Warn if serialPersistentFields is initialized to a
5310 // literal null.
5311 JCTree spfDecl = TreeInfo.declarationFor(spf, tree);
5312 if (spfDecl != null && spfDecl.getTag() == VARDEF) {
5313 JCVariableDecl variableDef = (JCVariableDecl) spfDecl;
5314 JCExpression initExpr = variableDef.init;
5315 if (initExpr != null && TreeInfo.isNull(initExpr)) {
5316 log.warning(LintCategory.SERIAL, initExpr.pos(),
5317 Warnings.SPFNullInit);
5318 }
5319 }
5320 }
5321
5322 private void checkWriteObject(JCClassDecl tree, Element e, MethodSymbol method) {
5323 // The "synchronized" modifier is seen in the wild on
5324 // readObject and writeObject methods and is generally
5325 // innocuous.
5326
5327 // private void writeObject(ObjectOutputStream stream) throws IOException
5328 checkPrivateNonStaticMethod(tree, method);
5329 checkReturnType(tree, e, method, syms.voidType);
5330 checkOneArg(tree, e, method, syms.objectOutputStreamType);
5331 checkExceptions(tree, e, method, syms.ioExceptionType);
5332 checkExternalizable(tree, e, method);
5333 }
5334
5335 private void checkWriteReplace(JCClassDecl tree, Element e, MethodSymbol method) {
5336 // ANY-ACCESS-MODIFIER Object writeReplace() throws
5337 // ObjectStreamException
5338
5339 // Excluding abstract, could have a more complicated
5340 // rule based on abstract-ness of the class
5341 checkConcreteInstanceMethod(tree, e, method);
5342 checkReturnType(tree, e, method, syms.objectType);
5343 checkNoArgs(tree, e, method);
5344 checkExceptions(tree, e, method, syms.objectStreamExceptionType);
5345 }
5346
5347 private void checkReadObject(JCClassDecl tree, Element e, MethodSymbol method) {
5348 // The "synchronized" modifier is seen in the wild on
5349 // readObject and writeObject methods and is generally
5350 // innocuous.
5351
5352 // private void readObject(ObjectInputStream stream)
5353 // throws IOException, ClassNotFoundException
5354 checkPrivateNonStaticMethod(tree, method);
5355 checkReturnType(tree, e, method, syms.voidType);
5356 checkOneArg(tree, e, method, syms.objectInputStreamType);
5357 checkExceptions(tree, e, method, syms.ioExceptionType, syms.classNotFoundExceptionType);
5358 checkExternalizable(tree, e, method);
5359 }
5360
5361 private void checkReadObjectNoData(JCClassDecl tree, Element e, MethodSymbol method) {
5362 // private void readObjectNoData() throws ObjectStreamException
5363 checkPrivateNonStaticMethod(tree, method);
5364 checkReturnType(tree, e, method, syms.voidType);
5365 checkNoArgs(tree, e, method);
5366 checkExceptions(tree, e, method, syms.objectStreamExceptionType);
5367 checkExternalizable(tree, e, method);
5368 }
5369
5370 private void checkReadResolve(JCClassDecl tree, Element e, MethodSymbol method) {
5371 // ANY-ACCESS-MODIFIER Object readResolve()
5372 // throws ObjectStreamException
5373
5374 // Excluding abstract, could have a more complicated
5375 // rule based on abstract-ness of the class
5376 checkConcreteInstanceMethod(tree, e, method);
5377 checkReturnType(tree,e, method, syms.objectType);
5378 checkNoArgs(tree, e, method);
5379 checkExceptions(tree, e, method, syms.objectStreamExceptionType);
5380 }
5381
5382 private void checkWriteExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5383 //public void writeExternal(ObjectOutput) throws IOException
5384 checkExternMethodRecord(tree, e, method, syms.objectOutputType, isExtern);
5385 }
5386
5387 private void checkReadExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) {
5388 // public void readExternal(ObjectInput) throws IOException
5389 checkExternMethodRecord(tree, e, method, syms.objectInputType, isExtern);
5390 }
5391
5392 private void checkExternMethodRecord(JCClassDecl tree, Element e, MethodSymbol method, Type argType,
5393 boolean isExtern) {
5394 if (isExtern && isExternMethod(tree, e, method, argType)) {
5395 log.warning(LintCategory.SERIAL,
5396 TreeInfo.diagnosticPositionFor(method, tree),
5397 Warnings.IneffectualExternalizableMethodRecord(method.getSimpleName().toString()));
5398 }
5399 }
5400
5401 void checkPrivateNonStaticMethod(JCClassDecl tree, MethodSymbol method) {
5402 var flags = method.flags();
5403 if ((flags & PRIVATE) == 0) {
5404 log.warning(LintCategory.SERIAL,
5405 TreeInfo.diagnosticPositionFor(method, tree),
5406 Warnings.SerialMethodNotPrivate(method.getSimpleName()));
5407 }
5408
5409 if ((flags & STATIC) != 0) {
5410 log.warning(LintCategory.SERIAL,
5411 TreeInfo.diagnosticPositionFor(method, tree),
5412 Warnings.SerialMethodStatic(method.getSimpleName()));
5413 }
5414 }
5415
5416 /**
5417 * Per section 1.12 "Serialization of Enum Constants" of
5418 * the serialization specification, due to the special
5419 * serialization handling of enums, any writeObject,
5420 * readObject, writeReplace, and readResolve methods are
5421 * ignored as are serialPersistentFields and
5422 * serialVersionUID fields.
5423 */
5424 @Override
5425 public Void visitTypeAsEnum(TypeElement e,
5426 JCClassDecl p) {
5427 boolean isExtern = isExternalizable((Type)e.asType());
5428 for(Element el : e.getEnclosedElements()) {
5429 runUnderLint(el, p, (enclosed, tree) -> {
5430 String name = enclosed.getSimpleName().toString();
5431 switch(enclosed.getKind()) {
5432 case FIELD -> {
5433 var field = (VarSymbol)enclosed;
5434 if (serialFieldNames.contains(name)) {
5435 log.warning(LintCategory.SERIAL,
5436 TreeInfo.diagnosticPositionFor(field, tree),
5437 Warnings.IneffectualSerialFieldEnum(name));
5438 }
5439 }
5440
5441 case METHOD -> {
5442 var method = (MethodSymbol)enclosed;
5443 if (serialMethodNames.contains(name)) {
5444 log.warning(LintCategory.SERIAL,
5445 TreeInfo.diagnosticPositionFor(method, tree),
5446 Warnings.IneffectualSerialMethodEnum(name));
5447 }
5448
5449 if (isExtern) {
5450 switch(name) {
5451 case "writeExternal" -> checkWriteExternalEnum(tree, e, method);
5452 case "readExternal" -> checkReadExternalEnum(tree, e, method);
5453 }
5454 }
5455 }
5456
5457 // Also perform checks on any class bodies of enum constants, see JLS 8.9.1.
5458 case ENUM_CONSTANT -> {
5459 var field = (VarSymbol)enclosed;
5460 JCVariableDecl decl = (JCVariableDecl) TreeInfo.declarationFor(field, p);
5461 if (decl.init instanceof JCNewClass nc && nc.def != null) {
5462 ClassSymbol enumConstantType = nc.def.sym;
5463 visitTypeAsEnum(enumConstantType, p);
5464 }
5465 }
5466
5467 }});
5468 }
5469 return null;
5470 }
5471
5472 private void checkWriteExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5473 //public void writeExternal(ObjectOutput) throws IOException
5474 checkExternMethodEnum(tree, e, method, syms.objectOutputType);
5475 }
5476
5477 private void checkReadExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) {
5478 // public void readExternal(ObjectInput) throws IOException
5479 checkExternMethodEnum(tree, e, method, syms.objectInputType);
5480 }
5481
5482 private void checkExternMethodEnum(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5483 if (isExternMethod(tree, e, method, argType)) {
5484 log.warning(LintCategory.SERIAL,
5485 TreeInfo.diagnosticPositionFor(method, tree),
5486 Warnings.IneffectualExternMethodEnum(method.getSimpleName().toString()));
5487 }
5488 }
5489
5490 private boolean isExternMethod(JCClassDecl tree, Element e, MethodSymbol method, Type argType) {
5491 long flags = method.flags();
5492 Type rtype = method.getReturnType();
5493
5494 // Not necessary to check throws clause in this context
5495 return (flags & PUBLIC) != 0 && (flags & STATIC) == 0 &&
5496 types.isSameType(syms.voidType, rtype) &&
5497 hasExactlyOneArgWithType(tree, e, method, argType);
5498 }
5499
5500 /**
5501 * Most serialization-related fields and methods on interfaces
5502 * are ineffectual or problematic.
5503 */
5504 @Override
5505 public Void visitTypeAsInterface(TypeElement e,
5506 JCClassDecl p) {
5507 for(Element el : e.getEnclosedElements()) {
5508 runUnderLint(el, p, (enclosed, tree) -> {
5509 String name = null;
5510 switch(enclosed.getKind()) {
5511 case FIELD -> {
5512 var field = (VarSymbol)enclosed;
5513 name = field.getSimpleName().toString();
5514 switch(name) {
5515 case "serialPersistentFields" -> {
5516 log.warning(LintCategory.SERIAL,
5517 TreeInfo.diagnosticPositionFor(field, tree),
5518 Warnings.IneffectualSerialFieldInterface);
5519 }
5520
5521 case "serialVersionUID" -> {
5522 checkSerialVersionUID(tree, e, field);
5523 }
5524 }
5525 }
5526
5527 case METHOD -> {
5528 var method = (MethodSymbol)enclosed;
5529 name = enclosed.getSimpleName().toString();
5530 if (serialMethodNames.contains(name)) {
5531 switch (name) {
5532 case
5533 "readObject",
5534 "readObjectNoData",
5535 "writeObject" -> checkPrivateMethod(tree, e, method);
5536
5537 case
5538 "writeReplace",
5539 "readResolve" -> checkDefaultIneffective(tree, e, method);
5540
5541 default -> throw new AssertionError();
5542 }
5543
5544 }
5545 }}
5546 });
5547 }
5548
5549 return null;
5550 }
5551
5552 private void checkPrivateMethod(JCClassDecl tree,
5553 Element e,
5554 MethodSymbol method) {
5555 if ((method.flags() & PRIVATE) == 0) {
5556 log.warning(LintCategory.SERIAL,
5557 TreeInfo.diagnosticPositionFor(method, tree),
5558 Warnings.NonPrivateMethodWeakerAccess);
5559 }
5560 }
5561
5562 private void checkDefaultIneffective(JCClassDecl tree,
5563 Element e,
5564 MethodSymbol method) {
5565 if ((method.flags() & DEFAULT) == DEFAULT) {
5566 log.warning(LintCategory.SERIAL,
5567 TreeInfo.diagnosticPositionFor(method, tree),
5568 Warnings.DefaultIneffective);
5569
5570 }
5571 }
5572
5573 @Override
5574 public Void visitTypeAsAnnotationType(TypeElement e,
5575 JCClassDecl p) {
5576 // Per the JLS, annotation types are not serializeable
5577 return null;
5578 }
5579
5580 /**
5581 * From the Java Object Serialization Specification, 1.13
5582 * Serialization of Records:
5583 *
5584 * "The process by which record objects are serialized or
5585 * externalized cannot be customized; any class-specific
5586 * writeObject, readObject, readObjectNoData, writeExternal,
5587 * and readExternal methods defined by record classes are
5588 * ignored during serialization and deserialization. However,
5589 * a substitute object to be serialized or a designate
5590 * replacement may be specified, by the writeReplace and
5591 * readResolve methods, respectively. Any
5592 * serialPersistentFields field declaration is
5593 * ignored. Documenting serializable fields and data for
5594 * record classes is unnecessary, since there is no variation
5595 * in the serial form, other than whether a substitute or
5596 * replacement object is used. The serialVersionUID of a
5597 * record class is 0L unless explicitly declared. The
5598 * requirement for matching serialVersionUID values is waived
5599 * for record classes."
5600 */
5601 @Override
5602 public Void visitTypeAsRecord(TypeElement e,
5603 JCClassDecl p) {
5604 boolean isExtern = isExternalizable((Type)e.asType());
5605 for(Element el : e.getEnclosedElements()) {
5606 runUnderLint(el, p, (enclosed, tree) -> {
5607 String name = enclosed.getSimpleName().toString();
5608 switch(enclosed.getKind()) {
5609 case FIELD -> {
5610 var field = (VarSymbol)enclosed;
5611 switch(name) {
5612 case "serialPersistentFields" -> {
5613 log.warning(LintCategory.SERIAL,
5614 TreeInfo.diagnosticPositionFor(field, tree),
5615 Warnings.IneffectualSerialFieldRecord);
5616 }
5617
5618 case "serialVersionUID" -> {
5619 // Could generate additional warning that
5620 // svuid value is not checked to match for
5621 // records.
5622 checkSerialVersionUID(tree, e, field);
5623 }}
5624 }
5625
5626 case METHOD -> {
5627 var method = (MethodSymbol)enclosed;
5628 switch(name) {
5629 case "writeReplace" -> checkWriteReplace(tree, e, method);
5630 case "readResolve" -> checkReadResolve(tree, e, method);
5631
5632 case "writeExternal" -> checkWriteExternalRecord(tree, e, method, isExtern);
5633 case "readExternal" -> checkReadExternalRecord(tree, e, method, isExtern);
5634
5635 default -> {
5636 if (serialMethodNames.contains(name)) {
5637 log.warning(LintCategory.SERIAL,
5638 TreeInfo.diagnosticPositionFor(method, tree),
5639 Warnings.IneffectualSerialMethodRecord(name));
5640 }
5641 }}
5642 }}});
5643 }
5644 return null;
5645 }
5646
5647 void checkConcreteInstanceMethod(JCClassDecl tree,
5648 Element enclosing,
5649 MethodSymbol method) {
5650 if ((method.flags() & (STATIC | ABSTRACT)) != 0) {
5651 log.warning(LintCategory.SERIAL,
5652 TreeInfo.diagnosticPositionFor(method, tree),
5653 Warnings.SerialConcreteInstanceMethod(method.getSimpleName()));
5654 }
5655 }
5656
5657 private void checkReturnType(JCClassDecl tree,
5658 Element enclosing,
5659 MethodSymbol method,
5660 Type expectedReturnType) {
5661 // Note: there may be complications checking writeReplace
5662 // and readResolve since they return Object and could, in
5663 // principle, have covariant overrides and any synthetic
5664 // bridge method would not be represented here for
5665 // checking.
5666 Type rtype = method.getReturnType();
5667 if (!types.isSameType(expectedReturnType, rtype)) {
5668 log.warning(LintCategory.SERIAL,
5669 TreeInfo.diagnosticPositionFor(method, tree),
5670 Warnings.SerialMethodUnexpectedReturnType(method.getSimpleName(),
5671 rtype, expectedReturnType));
5672 }
5673 }
5674
5675 private void checkOneArg(JCClassDecl tree,
5676 Element enclosing,
5677 MethodSymbol method,
5678 Type expectedType) {
5679 String name = method.getSimpleName().toString();
5680
5681 var parameters= method.getParameters();
5682
5683 if (parameters.size() != 1) {
5684 log.warning(LintCategory.SERIAL,
5685 TreeInfo.diagnosticPositionFor(method, tree),
5686 Warnings.SerialMethodOneArg(method.getSimpleName(), parameters.size()));
5687 return;
5688 }
5689
5690 Type parameterType = parameters.get(0).asType();
5691 if (!types.isSameType(parameterType, expectedType)) {
5692 log.warning(LintCategory.SERIAL,
5693 TreeInfo.diagnosticPositionFor(method, tree),
5694 Warnings.SerialMethodParameterType(method.getSimpleName(),
5695 expectedType,
5696 parameterType));
5697 }
5698 }
5699
5700 private boolean hasExactlyOneArgWithType(JCClassDecl tree,
5701 Element enclosing,
5702 MethodSymbol method,
5703 Type expectedType) {
5704 var parameters = method.getParameters();
5705 return (parameters.size() == 1) &&
5706 types.isSameType(parameters.get(0).asType(), expectedType);
5707 }
5708
5709
5710 private void checkNoArgs(JCClassDecl tree, Element enclosing, MethodSymbol method) {
5711 var parameters = method.getParameters();
5712 if (!parameters.isEmpty()) {
5713 log.warning(LintCategory.SERIAL,
5714 TreeInfo.diagnosticPositionFor(parameters.get(0), tree),
5715 Warnings.SerialMethodNoArgs(method.getSimpleName()));
5716 }
5717 }
5718
5719 private void checkExternalizable(JCClassDecl tree, Element enclosing, MethodSymbol method) {
5720 // If the enclosing class is externalizable, warn for the method
5721 if (isExternalizable((Type)enclosing.asType())) {
5722 log.warning(LintCategory.SERIAL,
5723 TreeInfo.diagnosticPositionFor(method, tree),
5724 Warnings.IneffectualSerialMethodExternalizable(method.getSimpleName()));
5725 }
5726 return;
5727 }
5728
5729 private void checkExceptions(JCClassDecl tree,
5730 Element enclosing,
5731 MethodSymbol method,
5732 Type... declaredExceptions) {
5733 for (Type thrownType: method.getThrownTypes()) {
5734 // For each exception in the throws clause of the
5735 // method, if not an Error and not a RuntimeException,
5736 // check if the exception is a subtype of a declared
5737 // exception from the throws clause of the
5738 // serialization method in question.
5739 if (types.isSubtype(thrownType, syms.runtimeExceptionType) ||
5740 types.isSubtype(thrownType, syms.errorType) ) {
5741 continue;
5742 } else {
5743 boolean declared = false;
5744 for (Type declaredException : declaredExceptions) {
5745 if (types.isSubtype(thrownType, declaredException)) {
5746 declared = true;
5747 continue;
5748 }
5749 }
5750 if (!declared) {
5751 log.warning(LintCategory.SERIAL,
5752 TreeInfo.diagnosticPositionFor(method, tree),
5753 Warnings.SerialMethodUnexpectedException(method.getSimpleName(),
5754 thrownType));
5755 }
5756 }
5757 }
5758 return;
5759 }
5760
5761 private <E extends Element> Void runUnderLint(E symbol, JCClassDecl p, BiConsumer<E, JCClassDecl> task) {
5762 Lint prevLint = lint;
5763 try {
5764 lint = lint.augment((Symbol) symbol);
5765
5766 if (lint.isEnabled(LintCategory.SERIAL)) {
5767 task.accept(symbol, p);
5768 }
5769
5770 return null;
5771 } finally {
5772 lint = prevLint;
5773 }
5774 }
5775
5776 }
5777
5778 }