1 /*
2 * Copyright (c) 1999, 2021, 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.Predicate;
31 import java.util.function.Supplier;
32
33 import javax.lang.model.element.ElementKind;
34 import javax.lang.model.element.NestingKind;
35 import javax.tools.JavaFileManager;
36
37 import com.sun.source.tree.CaseTree;
38 import com.sun.tools.javac.code.*;
39 import com.sun.tools.javac.code.Attribute.Compound;
40 import com.sun.tools.javac.code.Directive.ExportsDirective;
41 import com.sun.tools.javac.code.Directive.RequiresDirective;
42 import com.sun.tools.javac.code.Source.Feature;
43 import com.sun.tools.javac.comp.Annotate.AnnotationTypeMetadata;
44 import com.sun.tools.javac.jvm.*;
45 import com.sun.tools.javac.resources.CompilerProperties.Errors;
46 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
47 import com.sun.tools.javac.resources.CompilerProperties.Warnings;
48 import com.sun.tools.javac.tree.*;
49 import com.sun.tools.javac.util.*;
50 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
51 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
52 import com.sun.tools.javac.util.JCDiagnostic.Error;
53 import com.sun.tools.javac.util.JCDiagnostic.Fragment;
54 import com.sun.tools.javac.util.JCDiagnostic.Warning;
55 import com.sun.tools.javac.util.List;
56
57 import com.sun.tools.javac.code.Lint;
58 import com.sun.tools.javac.code.Lint.LintCategory;
59 import com.sun.tools.javac.code.Scope.WriteableScope;
60 import com.sun.tools.javac.code.Type.*;
61 import com.sun.tools.javac.code.Symbol.*;
62 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
63 import com.sun.tools.javac.tree.JCTree.*;
64
65 import static com.sun.tools.javac.code.Flags.*;
66 import static com.sun.tools.javac.code.Flags.ANNOTATION;
67 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED;
68 import static com.sun.tools.javac.code.Kinds.*;
69 import static com.sun.tools.javac.code.Kinds.Kind.*;
70 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
71 import static com.sun.tools.javac.code.TypeTag.*;
72 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
73
74 import static com.sun.tools.javac.tree.JCTree.Tag.*;
75 import javax.lang.model.element.Element;
76 import javax.lang.model.element.ExecutableElement;
77 import javax.lang.model.element.TypeElement;
78 import javax.lang.model.type.DeclaredType;
79 import javax.lang.model.type.TypeMirror;
80 import javax.lang.model.util.ElementFilter;
81 import javax.lang.model.util.ElementKindVisitor14;
82
83 /** Type checking helper class for the attribution phase.
84 *
85 * <p><b>This is NOT part of any supported API.
86 * If you write code that depends on this, you do so at your own risk.
87 * This code and its internal interfaces are subject to change or
88 * deletion without notice.</b>
89 */
90 public class Check {
91 protected static final Context.Key<Check> checkKey = new Context.Key<>();
92
93 private final Names names;
94 private final Log log;
95 private final Resolve rs;
96 private final Symtab syms;
97 private final Enter enter;
98 private final DeferredAttr deferredAttr;
99 private final Infer infer;
100 private final Types types;
101 private final TypeAnnotations typeAnnotations;
102 private final JCDiagnostic.Factory diags;
103 private final JavaFileManager fileManager;
104 private final Source source;
105 private final Target target;
106 private final Profile profile;
107 private final Preview preview;
108 private final boolean warnOnAnyAccessToMembers;
109
110 // The set of lint options currently in effect. It is initialized
111 // from the context, and then is set/reset as needed by Attr as it
112 // visits all the various parts of the trees during attribution.
113 private Lint lint;
114
115 // The method being analyzed in Attr - it is set/reset as needed by
116 // Attr as it visits new method declarations.
117 private MethodSymbol method;
118
119 public static Check instance(Context context) {
120 Check instance = context.get(checkKey);
121 if (instance == null)
122 instance = new Check(context);
123 return instance;
124 }
125
126 protected Check(Context context) {
127 context.put(checkKey, this);
128
129 names = Names.instance(context);
130 log = Log.instance(context);
131 rs = Resolve.instance(context);
132 syms = Symtab.instance(context);
133 enter = Enter.instance(context);
134 deferredAttr = DeferredAttr.instance(context);
135 infer = Infer.instance(context);
136 types = Types.instance(context);
137 typeAnnotations = TypeAnnotations.instance(context);
138 diags = JCDiagnostic.Factory.instance(context);
139 Options options = Options.instance(context);
140 lint = Lint.instance(context);
141 fileManager = context.get(JavaFileManager.class);
142
143 source = Source.instance(context);
144 target = Target.instance(context);
145 warnOnAnyAccessToMembers = options.isSet("warnOnAccessToMembers");
146 Target target = Target.instance(context);
147 syntheticNameChar = target.syntheticNameChar();
148
149 profile = Profile.instance(context);
150 preview = Preview.instance(context);
151
152 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
153 boolean verboseRemoval = lint.isEnabled(LintCategory.REMOVAL);
154 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
155 boolean enforceMandatoryWarnings = true;
156
157 deprecationHandler = new MandatoryWarningHandler(log, null, verboseDeprecated,
158 enforceMandatoryWarnings, "deprecated", LintCategory.DEPRECATION);
159 removalHandler = new MandatoryWarningHandler(log, null, verboseRemoval,
160 enforceMandatoryWarnings, "removal", LintCategory.REMOVAL);
161 uncheckedHandler = new MandatoryWarningHandler(log, null, verboseUnchecked,
162 enforceMandatoryWarnings, "unchecked", LintCategory.UNCHECKED);
163 sunApiHandler = new MandatoryWarningHandler(log, null, false,
164 enforceMandatoryWarnings, "sunapi", null);
165
166 deferredLintHandler = DeferredLintHandler.instance(context);
167
168 allowModules = Feature.MODULES.allowedInSource(source);
169 allowRecords = Feature.RECORDS.allowedInSource(source);
170 allowSealed = Feature.SEALED_CLASSES.allowedInSource(source);
171 }
172
173 /** Character for synthetic names
174 */
175 char syntheticNameChar;
176
177 /** A table mapping flat names of all compiled classes for each module in this run
178 * to their symbols; maintained from outside.
179 */
180 private Map<Pair<ModuleSymbol, Name>,ClassSymbol> compiled = new HashMap<>();
181
182 /** A handler for messages about deprecated usage.
183 */
184 private MandatoryWarningHandler deprecationHandler;
185
186 /** A handler for messages about deprecated-for-removal usage.
187 */
188 private MandatoryWarningHandler removalHandler;
189
190 /** A handler for messages about unchecked or unsafe usage.
191 */
192 private MandatoryWarningHandler uncheckedHandler;
193
194 /** A handler for messages about using proprietary API.
195 */
196 private MandatoryWarningHandler sunApiHandler;
197
198 /** A handler for deferred lint warnings.
199 */
200 private DeferredLintHandler deferredLintHandler;
201
202 /** Are modules allowed
203 */
204 private final boolean allowModules;
205
206 /** Are records allowed
207 */
208 private final boolean allowRecords;
209
210 /** Are sealed classes allowed
211 */
212 private final boolean allowSealed;
213
214 /* *************************************************************************
215 * Errors and Warnings
216 **************************************************************************/
217
218 Lint setLint(Lint newLint) {
219 Lint prev = lint;
220 lint = newLint;
221 return prev;
222 }
223
224 MethodSymbol setMethod(MethodSymbol newMethod) {
225 MethodSymbol prev = method;
226 method = newMethod;
227 return prev;
228 }
229
230 /** Warn about deprecated symbol.
231 * @param pos Position to be used for error reporting.
232 * @param sym The deprecated symbol.
233 */
234 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
235 if (sym.isDeprecatedForRemoval()) {
236 if (!lint.isSuppressed(LintCategory.REMOVAL)) {
237 if (sym.kind == MDL) {
238 removalHandler.report(pos, Warnings.HasBeenDeprecatedForRemovalModule(sym));
239 } else {
240 removalHandler.report(pos, Warnings.HasBeenDeprecatedForRemoval(sym, sym.location()));
241 }
242 }
243 } else if (!lint.isSuppressed(LintCategory.DEPRECATION)) {
244 if (sym.kind == MDL) {
245 deprecationHandler.report(pos, Warnings.HasBeenDeprecatedModule(sym));
246 } else {
247 deprecationHandler.report(pos, Warnings.HasBeenDeprecated(sym, sym.location()));
248 }
249 }
250 }
251
252 /** Log a preview warning.
253 * @param pos Position to be used for error reporting.
254 * @param msg A Warning describing the problem.
255 */
256 public void warnPreviewAPI(DiagnosticPosition pos, Warning warnKey) {
257 if (!lint.isSuppressed(LintCategory.PREVIEW))
258 preview.reportPreviewWarning(pos, warnKey);
259 }
260
261 /** Log a preview warning.
262 * @param pos Position to be used for error reporting.
263 * @param msg A Warning describing the problem.
264 */
265 public void warnDeclaredUsingPreview(DiagnosticPosition pos, Symbol sym) {
266 if (!lint.isSuppressed(LintCategory.PREVIEW))
267 preview.reportPreviewWarning(pos, Warnings.DeclaredUsingPreview(kindName(sym), sym));
268 }
269
270 /** Warn about unchecked operation.
271 * @param pos Position to be used for error reporting.
272 * @param msg A string describing the problem.
273 */
274 public void warnUnchecked(DiagnosticPosition pos, Warning warnKey) {
275 if (!lint.isSuppressed(LintCategory.UNCHECKED))
276 uncheckedHandler.report(pos, warnKey);
277 }
278
279 /** Warn about unsafe vararg method decl.
280 * @param pos Position to be used for error reporting.
281 */
282 void warnUnsafeVararg(DiagnosticPosition pos, Warning warnKey) {
283 if (lint.isEnabled(LintCategory.VARARGS))
284 log.warning(LintCategory.VARARGS, pos, warnKey);
285 }
286
287 public void warnStatic(DiagnosticPosition pos, Warning warnKey) {
288 if (lint.isEnabled(LintCategory.STATIC))
289 log.warning(LintCategory.STATIC, pos, warnKey);
290 }
291
292 /** Warn about division by integer constant zero.
293 * @param pos Position to be used for error reporting.
294 */
295 void warnDivZero(DiagnosticPosition pos) {
296 if (lint.isEnabled(LintCategory.DIVZERO))
297 log.warning(LintCategory.DIVZERO, pos, Warnings.DivZero);
298 }
299
300 /**
301 * Report any deferred diagnostics.
302 */
303 public void reportDeferredDiagnostics() {
304 deprecationHandler.reportDeferredDiagnostic();
305 removalHandler.reportDeferredDiagnostic();
306 uncheckedHandler.reportDeferredDiagnostic();
307 sunApiHandler.reportDeferredDiagnostic();
308 }
309
310
311 /** Report a failure to complete a class.
312 * @param pos Position to be used for error reporting.
313 * @param ex The failure to report.
314 */
315 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
316 log.error(JCDiagnostic.DiagnosticFlag.NON_DEFERRABLE, pos, Errors.CantAccess(ex.sym, ex.getDetailValue()));
317 return syms.errType;
318 }
319
320 /** Report an error that wrong type tag was found.
321 * @param pos Position to be used for error reporting.
322 * @param required An internationalized string describing the type tag
323 * required.
324 * @param found The type that was found.
325 */
326 Type typeTagError(DiagnosticPosition pos, JCDiagnostic required, Object found) {
327 // this error used to be raised by the parser,
328 // but has been delayed to this point:
329 if (found instanceof Type type && type.hasTag(VOID)) {
330 log.error(pos, Errors.IllegalStartOfType);
331 return syms.errType;
332 }
333 log.error(pos, Errors.TypeFoundReq(found, required));
334 return types.createErrorType(found instanceof Type type ? type : syms.errType);
335 }
336
337 /** Report an error that symbol cannot be referenced before super
338 * has been called.
339 * @param pos Position to be used for error reporting.
340 * @param sym The referenced symbol.
341 */
342 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
343 log.error(pos, Errors.CantRefBeforeCtorCalled(sym));
344 }
345
346 /** Report duplicate declaration error.
347 */
348 void duplicateError(DiagnosticPosition pos, Symbol sym) {
349 if (!sym.type.isErroneous()) {
350 Symbol location = sym.location();
351 if (location.kind == MTH &&
352 ((MethodSymbol)location).isStaticOrInstanceInit()) {
353 log.error(pos,
354 Errors.AlreadyDefinedInClinit(kindName(sym),
355 sym,
356 kindName(sym.location()),
357 kindName(sym.location().enclClass()),
358 sym.location().enclClass()));
359 } else {
360 /* dont error if this is a duplicated parameter of a generated canonical constructor
361 * as we should have issued an error for the duplicated fields
362 */
363 if (location.kind != MTH ||
364 ((sym.owner.flags_field & GENERATEDCONSTR) == 0) ||
365 ((sym.owner.flags_field & RECORD) == 0)) {
366 log.error(pos,
367 Errors.AlreadyDefined(kindName(sym),
368 sym,
369 kindName(sym.location()),
370 sym.location()));
371 }
372 }
373 }
374 }
375
376 /** Report array/varargs duplicate declaration
377 */
378 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
379 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
380 log.error(pos, Errors.ArrayAndVarargs(sym1, sym2, sym2.location()));
381 }
382 }
383
384 /* ************************************************************************
385 * duplicate declaration checking
386 *************************************************************************/
387
388 /** Check that variable does not hide variable with same name in
389 * immediately enclosing local scope.
390 * @param pos Position for error reporting.
391 * @param v The symbol.
392 * @param s The scope.
393 */
394 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
395 for (Symbol sym : s.getSymbolsByName(v.name)) {
396 if (sym.owner != v.owner) break;
397 if (sym.kind == VAR &&
398 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
399 v.name != names.error) {
400 duplicateError(pos, sym);
401 return;
402 }
403 }
404 }
405
406 /** Check that a class or interface does not hide a class or
407 * interface with same name in immediately enclosing local scope.
408 * @param pos Position for error reporting.
409 * @param c The symbol.
410 * @param s The scope.
411 */
412 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
413 for (Symbol sym : s.getSymbolsByName(c.name)) {
414 if (sym.owner != c.owner) break;
415 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR) &&
416 sym.owner.kind.matches(KindSelector.VAL_MTH) &&
417 c.name != names.error) {
418 duplicateError(pos, sym);
419 return;
420 }
421 }
422 }
423
424 /** Check that class does not have the same name as one of
425 * its enclosing classes, or as a class defined in its enclosing scope.
426 * return true if class is unique in its enclosing scope.
427 * @param pos Position for error reporting.
428 * @param name The class name.
429 * @param s The enclosing scope.
430 */
431 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
432 for (Symbol sym : s.getSymbolsByName(name, NON_RECURSIVE)) {
433 if (sym.kind == TYP && sym.name != names.error) {
434 duplicateError(pos, sym);
435 return false;
436 }
437 }
438 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
439 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
440 duplicateError(pos, sym);
441 return true;
442 }
443 }
444 return true;
445 }
446
447 /* *************************************************************************
448 * Class name generation
449 **************************************************************************/
450
451
452 private Map<Pair<Name, Name>, Integer> localClassNameIndexes = new HashMap<>();
453
454 /** Return name of local class.
455 * This is of the form {@code <enclClass> $ n <classname> }
456 * where
457 * enclClass is the flat name of the enclosing class,
458 * classname is the simple name of the local class
459 */
460 public Name localClassName(ClassSymbol c) {
461 Name enclFlatname = c.owner.enclClass().flatname;
462 String enclFlatnameStr = enclFlatname.toString();
463 Pair<Name, Name> key = new Pair<>(enclFlatname, c.name);
464 Integer index = localClassNameIndexes.get(key);
465 for (int i = (index == null) ? 1 : index; ; i++) {
466 Name flatname = names.fromString(enclFlatnameStr
467 + syntheticNameChar + i + c.name);
468 if (getCompiled(c.packge().modle, flatname) == null) {
469 localClassNameIndexes.put(key, i + 1);
470 return flatname;
471 }
472 }
473 }
474
475 public void clearLocalClassNameIndexes(ClassSymbol c) {
476 if (c.owner != null && c.owner.kind != NIL) {
477 localClassNameIndexes.remove(new Pair<>(
478 c.owner.enclClass().flatname, c.name));
479 }
480 }
481
482 public void newRound() {
483 compiled.clear();
484 localClassNameIndexes.clear();
485 }
486
487 public void clear() {
488 deprecationHandler.clear();
489 removalHandler.clear();
490 uncheckedHandler.clear();
491 sunApiHandler.clear();
492 }
493
494 public void putCompiled(ClassSymbol csym) {
495 compiled.put(Pair.of(csym.packge().modle, csym.flatname), csym);
496 }
497
498 public ClassSymbol getCompiled(ClassSymbol csym) {
499 return compiled.get(Pair.of(csym.packge().modle, csym.flatname));
500 }
501
502 public ClassSymbol getCompiled(ModuleSymbol msym, Name flatname) {
503 return compiled.get(Pair.of(msym, flatname));
504 }
505
506 public void removeCompiled(ClassSymbol csym) {
507 compiled.remove(Pair.of(csym.packge().modle, csym.flatname));
508 }
509
510 /* *************************************************************************
511 * Type Checking
512 **************************************************************************/
513
514 /**
515 * A check context is an object that can be used to perform compatibility
516 * checks - depending on the check context, meaning of 'compatibility' might
517 * vary significantly.
518 */
519 public interface CheckContext {
520 /**
521 * Is type 'found' compatible with type 'req' in given context
522 */
523 boolean compatible(Type found, Type req, Warner warn);
524 /**
525 * Report a check error
526 */
527 void report(DiagnosticPosition pos, JCDiagnostic details);
528 /**
529 * Obtain a warner for this check context
530 */
531 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req);
532
533 public InferenceContext inferenceContext();
534
535 public DeferredAttr.DeferredAttrContext deferredAttrContext();
536 }
537
538 /**
539 * This class represent a check context that is nested within another check
540 * context - useful to check sub-expressions. The default behavior simply
541 * redirects all method calls to the enclosing check context leveraging
542 * the forwarding pattern.
543 */
544 static class NestedCheckContext implements CheckContext {
545 CheckContext enclosingContext;
546
547 NestedCheckContext(CheckContext enclosingContext) {
548 this.enclosingContext = enclosingContext;
549 }
550
551 public boolean compatible(Type found, Type req, Warner warn) {
552 return enclosingContext.compatible(found, req, warn);
553 }
554
555 public void report(DiagnosticPosition pos, JCDiagnostic details) {
556 enclosingContext.report(pos, details);
557 }
558
559 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
560 return enclosingContext.checkWarner(pos, found, req);
561 }
562
563 public InferenceContext inferenceContext() {
564 return enclosingContext.inferenceContext();
565 }
566
567 public DeferredAttrContext deferredAttrContext() {
568 return enclosingContext.deferredAttrContext();
569 }
570 }
571
572 /**
573 * Check context to be used when evaluating assignment/return statements
574 */
575 CheckContext basicHandler = new CheckContext() {
576 public void report(DiagnosticPosition pos, JCDiagnostic details) {
577 log.error(pos, Errors.ProbFoundReq(details));
578 }
579 public boolean compatible(Type found, Type req, Warner warn) {
580 return types.isAssignable(found, req, warn);
581 }
582
583 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
584 return convertWarner(pos, found, req);
585 }
586
587 public InferenceContext inferenceContext() {
588 return infer.emptyContext;
589 }
590
591 public DeferredAttrContext deferredAttrContext() {
592 return deferredAttr.emptyDeferredAttrContext;
593 }
594
595 @Override
596 public String toString() {
597 return "CheckContext: basicHandler";
598 }
599 };
600
601 /** Check that a given type is assignable to a given proto-type.
602 * If it is, return the type, otherwise return errType.
603 * @param pos Position to be used for error reporting.
604 * @param found The type that was found.
605 * @param req The type that was required.
606 */
607 public Type checkType(DiagnosticPosition pos, Type found, Type req) {
608 return checkType(pos, found, req, basicHandler);
609 }
610
611 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) {
612 final InferenceContext inferenceContext = checkContext.inferenceContext();
613 if (inferenceContext.free(req) || inferenceContext.free(found)) {
614 inferenceContext.addFreeTypeListener(List.of(req, found),
615 solvedContext -> checkType(pos, solvedContext.asInstType(found), solvedContext.asInstType(req), checkContext));
616 } else {
617 if (found.hasTag(CLASS)) {
618 if (inferenceContext != infer.emptyContext)
619 checkParameterizationByPrimitiveClass(pos, found);
620 }
621 }
622 if (req.hasTag(ERROR))
623 return req;
624 if (req.hasTag(NONE))
625 return found;
626 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) {
627 return found;
628 } else {
629 if (found.isNumeric() && req.isNumeric()) {
630 checkContext.report(pos, diags.fragment(Fragments.PossibleLossOfPrecision(found, req)));
631 return types.createErrorType(found);
632 }
633 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
634 return types.createErrorType(found);
635 }
636 }
637
638 /** Check that a given type can be cast to a given target type.
639 * Return the result of the cast.
640 * @param pos Position to be used for error reporting.
641 * @param found The type that is being cast.
642 * @param req The target type of the cast.
643 */
644 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
645 return checkCastable(pos, found, req, basicHandler);
646 }
647 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) {
648 if (types.isCastable(found, req, castWarner(pos, found, req))) {
649 return req;
650 } else {
651 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req)));
652 return types.createErrorType(found);
653 }
654 }
655
656 /** Check for redundant casts (i.e. where source type is a subtype of target type)
657 * The problem should only be reported for non-292 cast
658 */
659 public void checkRedundantCast(Env<AttrContext> env, final JCTypeCast tree) {
660 if (!tree.type.isErroneous()
661 && types.isSameType(tree.expr.type, tree.clazz.type)
662 && !(ignoreAnnotatedCasts && TreeInfo.containsTypeAnnotation(tree.clazz))
663 && !is292targetTypeCast(tree)) {
664 deferredLintHandler.report(() -> {
665 if (lint.isEnabled(LintCategory.CAST))
666 log.warning(LintCategory.CAST,
667 tree.pos(), Warnings.RedundantCast(tree.clazz.type));
668 });
669 }
670 }
671 //where
672 private boolean is292targetTypeCast(JCTypeCast tree) {
673 boolean is292targetTypeCast = false;
674 JCExpression expr = TreeInfo.skipParens(tree.expr);
675 if (expr.hasTag(APPLY)) {
676 JCMethodInvocation apply = (JCMethodInvocation)expr;
677 Symbol sym = TreeInfo.symbol(apply.meth);
678 is292targetTypeCast = sym != null &&
679 sym.kind == MTH &&
680 (sym.flags() & HYPOTHETICAL) != 0;
681 }
682 return is292targetTypeCast;
683 }
684
685 private static final boolean ignoreAnnotatedCasts = true;
686
687 /** Check that a type is within some bounds.
688 *
689 * Used in TypeApply to verify that, e.g., X in {@code V<X>} is a valid
690 * type argument.
691 * @param a The type that should be bounded by bs.
692 * @param bound The bound.
693 */
694 private boolean checkExtends(Type a, Type bound) {
695 if (a.isUnbound()) {
696 return true;
697 } else if (!a.hasTag(WILDCARD)) {
698 a = types.cvarUpperBound(a);
699 return types.isSubtype(a, bound);
700 } else if (a.isExtendsBound()) {
701 return types.isCastable(bound, types.wildUpperBound(a), types.noWarnings);
702 } else if (a.isSuperBound()) {
703 return !types.notSoftSubtype(types.wildLowerBound(a), bound);
704 }
705 return true;
706 }
707
708 /** Check that type is different from 'void'.
709 * @param pos Position to be used for error reporting.
710 * @param t The type to be checked.
711 */
712 Type checkNonVoid(DiagnosticPosition pos, Type t) {
713 if (t.hasTag(VOID)) {
714 log.error(pos, Errors.VoidNotAllowedHere);
715 return types.createErrorType(t);
716 } else {
717 return t;
718 }
719 }
720
721 Type checkClassOrArrayType(DiagnosticPosition pos, Type t) {
722 if (!t.hasTag(CLASS) && !t.hasTag(ARRAY) && !t.hasTag(ERROR)) {
723 return typeTagError(pos,
724 diags.fragment(Fragments.TypeReqClassArray),
725 asTypeParam(t));
726 } else {
727 return t;
728 }
729 }
730
731 /** Check that type is a class or interface type.
732 * @param pos Position to be used for error reporting.
733 * @param t The type to be checked.
734 */
735 Type checkClassType(DiagnosticPosition pos, Type t) {
736 if (!t.hasTag(CLASS) && !t.hasTag(ERROR)) {
737 return typeTagError(pos,
738 diags.fragment(Fragments.TypeReqClass),
739 asTypeParam(t));
740 } else {
741 return t;
742 }
743 }
744 //where
745 private Object asTypeParam(Type t) {
746 return (t.hasTag(TYPEVAR))
747 ? diags.fragment(Fragments.TypeParameter(t))
748 : t;
749 }
750
751 void checkSuperConstraintsOfValueClass(DiagnosticPosition pos, ClassSymbol c) {
752 for(Type st = types.supertype(c.type); st != Type.noType; st = types.supertype(st)) {
753 if (st == null || st.tsym == null || st.tsym.kind == ERR)
754 return;
755 if (st.tsym == syms.objectType.tsym)
756 return;
757 if (!st.tsym.isAbstract()) {
758 log.error(pos, Errors.ConcreteSupertypeForValueClass(c, st));
759 }
760 if ((st.tsym.flags() & HASINITBLOCK) != 0) {
761 log.error(pos, Errors.SuperClassDeclaresInitBlock(c, st));
762 }
763 // No instance fields and no arged constructors both mean inner classes
764 // cannot be super classes for primitive classes.
765 Type encl = st.getEnclosingType();
766 if (encl != null && encl.hasTag(CLASS)) {
767 log.error(pos, Errors.SuperClassCannotBeInner(c, st));
768 }
769 for (Symbol s : st.tsym.members().getSymbols(NON_RECURSIVE)) {
770 switch (s.kind) {
771 case VAR:
772 if ((s.flags() & STATIC) == 0) {
773 log.error(pos, Errors.SuperFieldNotAllowed(s, c, st));
774 }
775 break;
776 case MTH:
777 if ((s.flags() & SYNCHRONIZED) != 0) {
778 log.error(pos, Errors.SuperMethodCannotBeSynchronized(s, c, st));
779 } else if (s.isConstructor()) {
780 MethodSymbol m = (MethodSymbol)s;
781 if (m.getParameters().size() > 0) {
782 log.error(pos, Errors.SuperConstructorCannotTakeArguments(m, c, st));
783 } else {
784 if ((m.flags() & (GENERATEDCONSTR | EMPTYNOARGCONSTR)) == 0) {
785 log.error(pos, Errors.SuperNoArgConstructorMustBeEmpty(m, c, st));
786 }
787 }
788 }
789 break;
790 }
791 }
792 }
793 }
794
795 /** Check that type is a valid qualifier for a constructor reference expression
796 */
797 Type checkConstructorRefType(JCExpression expr, Type t) {
798 t = checkClassOrArrayType(expr, t);
799 if (t.hasTag(CLASS)) {
800 if ((t.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
801 log.error(expr, Errors.AbstractCantBeInstantiated(t.tsym));
802 t = types.createErrorType(t);
803 } else if ((t.tsym.flags() & ENUM) != 0) {
804 log.error(expr, Errors.EnumCantBeInstantiated);
805 t = types.createErrorType(t);
806 } else {
807 // Projection types may not be mentioned in constructor references
808 if (expr.hasTag(SELECT)) {
809 JCFieldAccess fieldAccess = (JCFieldAccess) expr;
810 if (fieldAccess.selected.type.isPrimitiveClass() &&
811 (fieldAccess.name == names.ref || fieldAccess.name == names.val)) {
812 log.error(expr, Errors.ProjectionCantBeInstantiated);
813 t = types.createErrorType(t);
814 }
815 }
816 t = checkClassType(expr, t, true);
817 }
818 } else if (t.hasTag(ARRAY)) {
819 if (!types.isReifiable(((ArrayType)t).elemtype)) {
820 log.error(expr, Errors.GenericArrayCreation);
821 t = types.createErrorType(t);
822 }
823 }
824 return t;
825 }
826
827 /** Check that type is a class or interface type.
828 * @param pos Position to be used for error reporting.
829 * @param t The type to be checked.
830 * @param noBounds True if type bounds are illegal here.
831 */
832 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
833 t = checkClassType(pos, t);
834 if (noBounds && t.isParameterized()) {
835 List<Type> args = t.getTypeArguments();
836 while (args.nonEmpty()) {
837 if (args.head.hasTag(WILDCARD))
838 return typeTagError(pos,
839 diags.fragment(Fragments.TypeReqExact),
840 args.head);
841 args = args.tail;
842 }
843 }
844 return t;
845 }
846
847 /** Check that type is a reference type, i.e. a class, interface or array type
848 * or a type variable.
849 * @param pos Position to be used for error reporting.
850 * @param t The type to be checked.
851 * @param primitiveClassOK If false, a primitive class does not qualify
852 */
853 Type checkRefType(DiagnosticPosition pos, Type t, boolean primitiveClassOK) {
854 if (t.isReference() && (primitiveClassOK || !types.isPrimitiveClass(t)))
855 return t;
856 else
857 return typeTagError(pos,
858 diags.fragment(Fragments.TypeReqRef),
859 t);
860 }
861
862 /** Check that type is an identity type, i.e. not a primitive type
863 * nor its reference projection. When not discernible statically,
864 * give it the benefit of doubt and defer to runtime.
865 *
866 * @param pos Position to be used for error reporting.
867 * @param t The type to be checked.
868 */
869 Type checkIdentityType(DiagnosticPosition pos, Type t) {
870
871 if (t.isPrimitive() || t.isValueClass() || t.isReferenceProjection())
872 return typeTagError(pos,
873 diags.fragment(Fragments.TypeReqIdentity),
874 t);
875
876 /* Not appropriate to check
877 * if (types.asSuper(t, syms.identityObjectType.tsym) != null)
878 * since jlO, interface types and abstract types may fail that check
879 * at compile time.
880 */
881
882 return t;
883 }
884
885 /** Check that type is a reference type, i.e. a class, interface or array type
886 * or a type variable.
887 * @param pos Position to be used for error reporting.
888 * @param t The type to be checked.
889 */
890 Type checkRefType(DiagnosticPosition pos, Type t) {
891 return checkRefType(pos, t, true);
892 }
893
894 /** Check that each type is a reference type, i.e. a class, interface or array type
895 * or a type variable.
896 * @param trees Original trees, used for error reporting.
897 * @param types The types to be checked.
898 */
899 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
900 List<JCExpression> tl = trees;
901 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
902 l.head = checkRefType(tl.head.pos(), l.head, false);
903 tl = tl.tail;
904 }
905 return types;
906 }
907
908 /** Check that type is a null or reference type.
909 * @param pos Position to be used for error reporting.
910 * @param t The type to be checked.
911 */
912 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
913 if (t.isReference() || t.hasTag(BOT))
914 return t;
915 else
916 return typeTagError(pos,
917 diags.fragment(Fragments.TypeReqRef),
918 t);
919 }
920
921 /** Check that flag set does not contain elements of two conflicting sets. s
922 * Return true if it doesn't.
923 * @param pos Position to be used for error reporting.
924 * @param flags The set of flags to be checked.
925 * @param set1 Conflicting flags set #1.
926 * @param set2 Conflicting flags set #2.
927 */
928 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
929 if ((flags & set1) != 0 && (flags & set2) != 0) {
930 log.error(pos,
931 Errors.IllegalCombinationOfModifiers(asFlagSet(TreeInfo.firstFlag(flags & set1)),
932 asFlagSet(TreeInfo.firstFlag(flags & set2))));
933 return false;
934 } else
935 return true;
936 }
937
938 void checkParameterizationByPrimitiveClass(DiagnosticPosition pos, Type t) {
939 parameterizationByPrimitiveClassChecker.visit(t, pos);
940 }
941
942 /** parameterizationByPrimitiveClassChecker: A type visitor that descends down the given type looking for instances of primitive classes
943 * being used as type arguments and issues error against those usages.
944 */
945 private final Types.SimpleVisitor<Void, DiagnosticPosition> parameterizationByPrimitiveClassChecker =
946 new Types.SimpleVisitor<Void, DiagnosticPosition>() {
947
948 @Override
949 public Void visitType(Type t, DiagnosticPosition pos) {
950 return null;
951 }
952
953 @Override
954 public Void visitClassType(ClassType t, DiagnosticPosition pos) {
955 for (Type targ : t.allparams()) {
956 if (types.isPrimitiveClass(targ)) {
957 log.error(pos, Errors.GenericParameterizationWithPrimitiveClass(t));
958 }
959 visit(targ, pos);
960 }
961 return null;
962 }
963
964 @Override
965 public Void visitTypeVar(TypeVar t, DiagnosticPosition pos) {
966 return null;
967 }
968
969 @Override
970 public Void visitCapturedType(CapturedType t, DiagnosticPosition pos) {
971 return null;
972 }
973
974 @Override
975 public Void visitArrayType(ArrayType t, DiagnosticPosition pos) {
976 return visit(t.elemtype, pos);
977 }
978
979 @Override
980 public Void visitWildcardType(WildcardType t, DiagnosticPosition pos) {
981 return visit(t.type, pos);
982 }
983 };
984
985
986
987 /** Check that usage of diamond operator is correct (i.e. diamond should not
988 * be used with non-generic classes or in anonymous class creation expressions)
989 */
990 Type checkDiamond(JCNewClass tree, Type t) {
991 if (!TreeInfo.isDiamond(tree) ||
992 t.isErroneous()) {
993 return checkClassType(tree.clazz.pos(), t, true);
994 } else {
995 if (tree.def != null && !Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.allowedInSource(source)) {
996 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.clazz.pos(),
997 Errors.CantApplyDiamond1(t, Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.fragment(source.name)));
998 }
999 if (t.tsym.type.getTypeArguments().isEmpty()) {
1000 log.error(tree.clazz.pos(),
1001 Errors.CantApplyDiamond1(t,
1002 Fragments.DiamondNonGeneric(t)));
1003 return types.createErrorType(t);
1004 } else if (tree.typeargs != null &&
1005 tree.typeargs.nonEmpty()) {
1006 log.error(tree.clazz.pos(),
1007 Errors.CantApplyDiamond1(t,
1008 Fragments.DiamondAndExplicitParams(t)));
1009 return types.createErrorType(t);
1010 } else {
1011 return t;
1012 }
1013 }
1014 }
1015
1016 /** Check that the type inferred using the diamond operator does not contain
1017 * non-denotable types such as captured types or intersection types.
1018 * @param t the type inferred using the diamond operator
1019 * @return the (possibly empty) list of non-denotable types.
1020 */
1021 List<Type> checkDiamondDenotable(ClassType t) {
1022 ListBuffer<Type> buf = new ListBuffer<>();
1023 for (Type arg : t.allparams()) {
1024 if (!checkDenotable(arg)) {
1025 buf.append(arg);
1026 }
1027 }
1028 return buf.toList();
1029 }
1030
1031 public boolean checkDenotable(Type t) {
1032 return denotableChecker.visit(t, null);
1033 }
1034 // where
1035
1036 /** diamondTypeChecker: A type visitor that descends down the given type looking for non-denotable
1037 * types. The visit methods return false as soon as a non-denotable type is encountered and true
1038 * otherwise.
1039 */
1040 private static final Types.SimpleVisitor<Boolean, Void> denotableChecker = new Types.SimpleVisitor<Boolean, Void>() {
1041 @Override
1042 public Boolean visitType(Type t, Void s) {
1043 return true;
1044 }
1045 @Override
1046 public Boolean visitClassType(ClassType t, Void s) {
1047 if (t.isUnion() || t.isIntersection()) {
1048 return false;
1049 }
1050 for (Type targ : t.allparams()) {
1051 if (!visit(targ, s)) {
1052 return false;
1053 }
1054 }
1055 return true;
1056 }
1057
1058 @Override
1059 public Boolean visitTypeVar(TypeVar t, Void s) {
1060 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
1061 (i.e cannot have been produced by inference (18.4))
1062 */
1063 return (t.tsym.flags() & SYNTHETIC) == 0;
1064 }
1065
1066 @Override
1067 public Boolean visitCapturedType(CapturedType t, Void s) {
1068 /* Any type variable mentioned in the inferred type must have been declared as a type parameter
1069 (i.e cannot have been produced by capture conversion (5.1.10))
1070 */
1071 return false;
1072 }
1073
1074 @Override
1075 public Boolean visitArrayType(ArrayType t, Void s) {
1076 return visit(t.elemtype, s);
1077 }
1078
1079 @Override
1080 public Boolean visitWildcardType(WildcardType t, Void s) {
1081 return visit(t.type, s);
1082 }
1083 };
1084
1085 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
1086 MethodSymbol m = tree.sym;
1087 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
1088 Type varargElemType = null;
1089 if (m.isVarArgs()) {
1090 varargElemType = types.elemtype(tree.params.last().type);
1091 }
1092 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
1093 if (varargElemType != null) {
1094 JCDiagnostic msg = Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ?
1095 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargs(m)) :
1096 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargsFinalOnly(m));
1097 log.error(tree,
1098 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
1099 msg));
1100 } else {
1101 log.error(tree,
1102 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym,
1103 Fragments.VarargsTrustmeOnNonVarargsMeth(m)));
1104 }
1105 } else if (hasTrustMeAnno && varargElemType != null &&
1106 types.isReifiable(varargElemType)) {
1107 warnUnsafeVararg(tree, Warnings.VarargsRedundantTrustmeAnno(
1108 syms.trustMeType.tsym,
1109 diags.fragment(Fragments.VarargsTrustmeOnReifiableVarargs(varargElemType))));
1110 }
1111 else if (!hasTrustMeAnno && varargElemType != null &&
1112 !types.isReifiable(varargElemType)) {
1113 warnUnchecked(tree.params.head.pos(), Warnings.UncheckedVarargsNonReifiableType(varargElemType));
1114 }
1115 }
1116 //where
1117 private boolean isTrustMeAllowedOnMethod(Symbol s) {
1118 return (s.flags() & VARARGS) != 0 &&
1119 (s.isConstructor() ||
1120 (s.flags() & (STATIC | FINAL |
1121 (Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ? PRIVATE : 0) )) != 0);
1122 }
1123
1124 Type checkLocalVarType(DiagnosticPosition pos, Type t, Name name) {
1125 //check that resulting type is not the null type
1126 if (t.hasTag(BOT)) {
1127 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferNull));
1128 return types.createErrorType(t);
1129 } else if (t.hasTag(VOID)) {
1130 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferVoid));
1131 return types.createErrorType(t);
1132 }
1133
1134 //upward project the initializer type
1135 Type varType = types.upward(t, types.captures(t));
1136 if (varType.hasTag(CLASS)) {
1137 checkParameterizationByPrimitiveClass(pos, varType);
1138 }
1139 return varType;
1140 }
1141
1142 public void checkForSuspectClassLiteralComparison(
1143 final JCBinary tree,
1144 final Type leftType,
1145 final Type rightType) {
1146
1147 if (lint.isEnabled(LintCategory.MIGRATION)) {
1148 if (isInvocationOfGetClass(tree.lhs) && isClassOfSomeInterface(rightType) ||
1149 isInvocationOfGetClass(tree.rhs) && isClassOfSomeInterface(leftType)) {
1150 log.warning(LintCategory.MIGRATION, tree.pos(), Warnings.GetClassComparedWithInterface);
1151 }
1152 }
1153 }
1154 //where
1155 private boolean isClassOfSomeInterface(Type someClass) {
1156 if (someClass.tsym.flatName() == names.java_lang_Class) {
1157 List<Type> arguments = someClass.getTypeArguments();
1158 if (arguments.length() == 1) {
1159 return arguments.head.isInterface();
1160 }
1161 }
1162 return false;
1163 }
1164 //where
1165 private boolean isInvocationOfGetClass(JCExpression tree) {
1166 tree = TreeInfo.skipParens(tree);
1167 if (tree.hasTag(APPLY)) {
1168 JCMethodInvocation apply = (JCMethodInvocation)tree;
1169 MethodSymbol msym = (MethodSymbol)TreeInfo.symbol(apply.meth);
1170 return msym.name == names.getClass && msym.implementedIn(syms.objectType.tsym, types) != null;
1171 }
1172 return false;
1173 }
1174
1175 Type checkMethod(final Type mtype,
1176 final Symbol sym,
1177 final Env<AttrContext> env,
1178 final List<JCExpression> argtrees,
1179 final List<Type> argtypes,
1180 final boolean useVarargs,
1181 InferenceContext inferenceContext) {
1182 // System.out.println("call : " + env.tree);
1183 // System.out.println("method : " + owntype);
1184 // System.out.println("actuals: " + argtypes);
1185 if (inferenceContext.free(mtype)) {
1186 inferenceContext.addFreeTypeListener(List.of(mtype),
1187 solvedContext -> checkMethod(solvedContext.asInstType(mtype), sym, env, argtrees, argtypes, useVarargs, solvedContext));
1188 return mtype;
1189 }
1190 Type owntype = mtype;
1191 List<Type> formals = owntype.getParameterTypes();
1192 List<Type> nonInferred = sym.type.getParameterTypes();
1193 if (nonInferred.length() != formals.length()) nonInferred = formals;
1194 Type last = useVarargs ? formals.last() : null;
1195 if (sym.name == names.init && sym.owner == syms.enumSym) {
1196 formals = formals.tail.tail;
1197 nonInferred = nonInferred.tail.tail;
1198 }
1199 if ((sym.flags() & ANONCONSTR_BASED) != 0) {
1200 formals = formals.tail;
1201 nonInferred = nonInferred.tail;
1202 }
1203 List<JCExpression> args = argtrees;
1204 if (args != null) {
1205 //this is null when type-checking a method reference
1206 while (formals.head != last) {
1207 JCTree arg = args.head;
1208 Warner warn = convertWarner(arg.pos(), arg.type, nonInferred.head);
1209 assertConvertible(arg, arg.type, formals.head, warn);
1210 args = args.tail;
1211 formals = formals.tail;
1212 nonInferred = nonInferred.tail;
1213 }
1214 if (useVarargs) {
1215 Type varArg = types.elemtype(last);
1216 while (args.tail != null) {
1217 JCTree arg = args.head;
1218 Warner warn = convertWarner(arg.pos(), arg.type, varArg);
1219 assertConvertible(arg, arg.type, varArg, warn);
1220 args = args.tail;
1221 }
1222 } else if ((sym.flags() & (VARARGS | SIGNATURE_POLYMORPHIC)) == VARARGS) {
1223 // non-varargs call to varargs method
1224 Type varParam = owntype.getParameterTypes().last();
1225 Type lastArg = argtypes.last();
1226 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
1227 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
1228 log.warning(argtrees.last().pos(),
1229 Warnings.InexactNonVarargsCall(types.elemtype(varParam),varParam));
1230 }
1231 }
1232 if (useVarargs) {
1233 Type argtype = owntype.getParameterTypes().last();
1234 if (!types.isReifiable(argtype) &&
1235 (sym.baseSymbol().attribute(syms.trustMeType.tsym) == null ||
1236 !isTrustMeAllowedOnMethod(sym))) {
1237 warnUnchecked(env.tree.pos(), Warnings.UncheckedGenericArrayCreation(argtype));
1238 }
1239 TreeInfo.setVarargsElement(env.tree, types.elemtype(argtype));
1240 }
1241 return owntype;
1242 }
1243 //where
1244 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
1245 if (types.isConvertible(actual, formal, warn))
1246 return;
1247
1248 if (formal.isCompound()
1249 && types.isSubtype(actual, types.supertype(formal))
1250 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
1251 return;
1252 }
1253
1254 /**
1255 * Check that type 't' is a valid instantiation of a generic class
1256 * (see JLS 4.5)
1257 *
1258 * @param t class type to be checked
1259 * @return true if 't' is well-formed
1260 */
1261 public boolean checkValidGenericType(Type t) {
1262 return firstIncompatibleTypeArg(t) == null;
1263 }
1264 //WHERE
1265 private Type firstIncompatibleTypeArg(Type type) {
1266 List<Type> formals = type.tsym.type.allparams();
1267 List<Type> actuals = type.allparams();
1268 List<Type> args = type.getTypeArguments();
1269 List<Type> forms = type.tsym.type.getTypeArguments();
1270 ListBuffer<Type> bounds_buf = new ListBuffer<>();
1271
1272 // For matching pairs of actual argument types `a' and
1273 // formal type parameters with declared bound `b' ...
1274 while (args.nonEmpty() && forms.nonEmpty()) {
1275 // exact type arguments needs to know their
1276 // bounds (for upper and lower bound
1277 // calculations). So we create new bounds where
1278 // type-parameters are replaced with actuals argument types.
1279 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals));
1280 args = args.tail;
1281 forms = forms.tail;
1282 }
1283
1284 args = type.getTypeArguments();
1285 List<Type> tvars_cap = types.substBounds(formals,
1286 formals,
1287 types.capture(type).allparams());
1288 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
1289 // Let the actual arguments know their bound
1290 args.head.withTypeVar((TypeVar)tvars_cap.head);
1291 args = args.tail;
1292 tvars_cap = tvars_cap.tail;
1293 }
1294
1295 args = type.getTypeArguments();
1296 List<Type> bounds = bounds_buf.toList();
1297
1298 while (args.nonEmpty() && bounds.nonEmpty()) {
1299 Type actual = args.head;
1300 if (!isTypeArgErroneous(actual) &&
1301 !bounds.head.isErroneous() &&
1302 !checkExtends(actual, bounds.head)) {
1303 return args.head;
1304 }
1305 args = args.tail;
1306 bounds = bounds.tail;
1307 }
1308
1309 args = type.getTypeArguments();
1310 bounds = bounds_buf.toList();
1311
1312 for (Type arg : types.capture(type).getTypeArguments()) {
1313 if (arg.hasTag(TYPEVAR) &&
1314 arg.getUpperBound().isErroneous() &&
1315 !bounds.head.isErroneous() &&
1316 !isTypeArgErroneous(args.head)) {
1317 return args.head;
1318 }
1319 bounds = bounds.tail;
1320 args = args.tail;
1321 }
1322
1323 return null;
1324 }
1325 //where
1326 boolean isTypeArgErroneous(Type t) {
1327 return isTypeArgErroneous.visit(t);
1328 }
1329
1330 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
1331 public Boolean visitType(Type t, Void s) {
1332 return t.isErroneous();
1333 }
1334 @Override
1335 public Boolean visitTypeVar(TypeVar t, Void s) {
1336 return visit(t.getUpperBound());
1337 }
1338 @Override
1339 public Boolean visitCapturedType(CapturedType t, Void s) {
1340 return visit(t.getUpperBound()) ||
1341 visit(t.getLowerBound());
1342 }
1343 @Override
1344 public Boolean visitWildcardType(WildcardType t, Void s) {
1345 return visit(t.type);
1346 }
1347 };
1348
1349 /** Check that given modifiers are legal for given symbol and
1350 * return modifiers together with any implicit modifiers for that symbol.
1351 * Warning: we can't use flags() here since this method
1352 * is called during class enter, when flags() would cause a premature
1353 * completion.
1354 * @param pos Position to be used for error reporting.
1355 * @param flags The set of modifiers given in a definition.
1356 * @param sym The defined symbol.
1357 */
1358 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
1359 long mask;
1360 long implicit = 0;
1361
1362 switch (sym.kind) {
1363 case VAR:
1364 if (TreeInfo.isReceiverParam(tree))
1365 mask = ReceiverParamFlags;
1366 else if (sym.owner.kind != TYP)
1367 mask = LocalVarFlags;
1368 else if ((sym.owner.flags_field & INTERFACE) != 0)
1369 mask = implicit = InterfaceVarFlags;
1370 else {
1371 mask = VarFlags;
1372 if (types.isValueClass(sym.owner.type) && (flags & STATIC) == 0) {
1373 implicit |= FINAL;
1374 }
1375 }
1376 break;
1377 case MTH:
1378 if (sym.name == names.init) {
1379 if ((sym.owner.flags_field & ENUM) != 0) {
1380 // enum constructors cannot be declared public or
1381 // protected and must be implicitly or explicitly
1382 // private
1383 implicit = PRIVATE;
1384 mask = PRIVATE;
1385 } else
1386 mask = ConstructorFlags;
1387 } else if ((sym.owner.flags_field & INTERFACE) != 0) {
1388 if ((sym.owner.flags_field & ANNOTATION) != 0) {
1389 mask = AnnotationTypeElementMask;
1390 implicit = PUBLIC | ABSTRACT;
1391 } else if ((flags & (DEFAULT | STATIC | PRIVATE)) != 0) {
1392 mask = InterfaceMethodMask;
1393 implicit = (flags & PRIVATE) != 0 ? 0 : PUBLIC;
1394 if ((flags & DEFAULT) != 0) {
1395 implicit |= ABSTRACT;
1396 }
1397 } else {
1398 mask = implicit = InterfaceMethodFlags;
1399 }
1400 } else if ((sym.owner.flags_field & RECORD) != 0) {
1401 mask = RecordMethodFlags;
1402 // FIXME: We tolerate synchronized methods in value records
1403 } else {
1404 // value objects do not have an associated monitor/lock
1405 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ?
1406 MethodFlags & ~SYNCHRONIZED : MethodFlags;
1407 }
1408 if ((flags & STRICTFP) != 0) {
1409 warnOnExplicitStrictfp(pos);
1410 }
1411 // Imply STRICTFP if owner has STRICTFP set.
1412 if (((flags|implicit) & Flags.ABSTRACT) == 0 ||
1413 ((flags) & Flags.DEFAULT) != 0)
1414 implicit |= sym.owner.flags_field & STRICTFP;
1415 break;
1416 case TYP:
1417 if (sym.owner.kind.matches(KindSelector.VAL_MTH) ||
1418 (sym.isDirectlyOrIndirectlyLocal() && (flags & ANNOTATION) != 0)) {
1419 boolean implicitlyStatic = !sym.isAnonymous() &&
1420 ((flags & RECORD) != 0 || (flags & ENUM) != 0 || (flags & INTERFACE) != 0);
1421 boolean staticOrImplicitlyStatic = (flags & STATIC) != 0 || implicitlyStatic;
1422 // local statics are allowed only if records are allowed too
1423 mask = staticOrImplicitlyStatic && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedStaticLocalClassFlags : ExtendedLocalClassFlags;
1424 implicit = implicitlyStatic ? STATIC : implicit;
1425 } else if (sym.owner.kind == TYP) {
1426 // statics in inner classes are allowed only if records are allowed too
1427 mask = ((flags & STATIC) != 0) && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedMemberStaticClassFlags : ExtendedMemberClassFlags;
1428 if (sym.owner.owner.kind == PCK ||
1429 (sym.owner.flags_field & STATIC) != 0) {
1430 mask |= STATIC;
1431 } else if (!allowRecords && ((flags & ENUM) != 0 || (flags & RECORD) != 0)) {
1432 log.error(pos, Errors.StaticDeclarationNotAllowedInInnerClasses);
1433 }
1434 // Nested interfaces and enums are always STATIC (Spec ???)
1435 if ((flags & (INTERFACE | ENUM | RECORD)) != 0 ) implicit = STATIC;
1436 } else {
1437 mask = ExtendedClassFlags;
1438 }
1439 // Interfaces are always ABSTRACT
1440 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
1441
1442 if ((flags & ENUM) != 0) {
1443 // enums can't be declared abstract, final, sealed or non-sealed or primitive/value
1444 mask &= ~(ABSTRACT | FINAL | SEALED | NON_SEALED | PRIMITIVE_CLASS | VALUE_CLASS);
1445 implicit |= implicitEnumFinalFlag(tree);
1446 }
1447 if ((flags & RECORD) != 0) {
1448 // records can't be declared abstract
1449 mask &= ~ABSTRACT;
1450 implicit |= FINAL;
1451 }
1452 if ((flags & STRICTFP) != 0) {
1453 warnOnExplicitStrictfp(pos);
1454 }
1455 // Imply STRICTFP if owner has STRICTFP set.
1456 implicit |= sym.owner.flags_field & STRICTFP;
1457
1458 // primitive classes are implicitly final value classes.
1459 if ((flags & PRIMITIVE_CLASS) != 0)
1460 implicit |= VALUE_CLASS | FINAL;
1461
1462 // value classes are implicitly final
1463 if ((flags & VALUE_CLASS) != 0)
1464 implicit |= FINAL;
1465
1466 break;
1467 default:
1468 throw new AssertionError();
1469 }
1470 long illegal = flags & ExtendedStandardFlags & ~mask;
1471 if (illegal != 0) {
1472 if ((illegal & INTERFACE) != 0) {
1473 log.error(pos, ((flags & ANNOTATION) != 0) ? Errors.AnnotationDeclNotAllowedHere : Errors.IntfNotAllowedHere);
1474 mask |= INTERFACE;
1475 }
1476 else {
1477 log.error(pos,
1478 Errors.ModNotAllowedHere(asFlagSet(illegal)));
1479 }
1480 }
1481 else if ((sym.kind == TYP ||
1482 // ISSUE: Disallowing abstract&private is no longer appropriate
1483 // in the presence of inner classes. Should it be deleted here?
1484 checkDisjoint(pos, flags,
1485 ABSTRACT,
1486 PRIVATE | STATIC | DEFAULT))
1487 &&
1488 checkDisjoint(pos, flags,
1489 STATIC | PRIVATE,
1490 DEFAULT)
1491 &&
1492 checkDisjoint(pos, flags,
1493 ABSTRACT | INTERFACE,
1494 FINAL | NATIVE | SYNCHRONIZED | PRIMITIVE_CLASS | VALUE_CLASS)
1495 &&
1496 checkDisjoint(pos, flags,
1497 PUBLIC,
1498 PRIVATE | PROTECTED)
1499 &&
1500 checkDisjoint(pos, flags,
1501 PRIVATE,
1502 PUBLIC | PROTECTED)
1503 &&
1504 checkDisjoint(pos, (flags | implicit), // complain against volatile & implcitly final entities too.
1505 FINAL,
1506 VOLATILE)
1507 &&
1508 (sym.kind == TYP ||
1509 checkDisjoint(pos, flags,
1510 ABSTRACT | NATIVE,
1511 STRICTFP))
1512 && checkDisjoint(pos, flags,
1513 FINAL,
1514 SEALED | NON_SEALED)
1515 && checkDisjoint(pos, flags,
1516 SEALED,
1517 FINAL | NON_SEALED)
1518 && checkDisjoint(pos, flags,
1519 SEALED,
1520 ANNOTATION)) {
1521 // skip
1522 }
1523 return flags & (mask | ~ExtendedStandardFlags) | implicit;
1524 }
1525
1526 private void warnOnExplicitStrictfp(DiagnosticPosition pos) {
1527 DiagnosticPosition prevLintPos = deferredLintHandler.setPos(pos);
1528 try {
1529 deferredLintHandler.report(() -> {
1530 if (lint.isEnabled(LintCategory.STRICTFP)) {
1531 log.warning(LintCategory.STRICTFP,
1532 pos, Warnings.Strictfp); }
1533 });
1534 } finally {
1535 deferredLintHandler.setPos(prevLintPos);
1536 }
1537 }
1538
1539
1540 /** Determine if this enum should be implicitly final.
1541 *
1542 * If the enum has no specialized enum constants, it is final.
1543 *
1544 * If the enum does have specialized enum constants, it is
1545 * <i>not</i> final.
1546 */
1547 private long implicitEnumFinalFlag(JCTree tree) {
1548 if (!tree.hasTag(CLASSDEF)) return 0;
1549 class SpecialTreeVisitor extends JCTree.Visitor {
1550 boolean specialized;
1551 SpecialTreeVisitor() {
1552 this.specialized = false;
1553 }
1554
1555 @Override
1556 public void visitTree(JCTree tree) { /* no-op */ }
1557
1558 @Override
1559 public void visitVarDef(JCVariableDecl tree) {
1560 if ((tree.mods.flags & ENUM) != 0) {
1561 if (tree.init instanceof JCNewClass newClass && newClass.def != null) {
1562 specialized = true;
1563 }
1564 }
1565 }
1566 }
1567
1568 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1569 JCClassDecl cdef = (JCClassDecl) tree;
1570 for (JCTree defs: cdef.defs) {
1571 defs.accept(sts);
1572 if (sts.specialized) return allowSealed ? SEALED : 0;
1573 }
1574 return FINAL;
1575 }
1576
1577 /* *************************************************************************
1578 * Type Validation
1579 **************************************************************************/
1580
1581 /** Validate a type expression. That is,
1582 * check that all type arguments of a parametric type are within
1583 * their bounds. This must be done in a second phase after type attribution
1584 * since a class might have a subclass as type parameter bound. E.g:
1585 *
1586 * <pre>{@code
1587 * class B<A extends C> { ... }
1588 * class C extends B<C> { ... }
1589 * }</pre>
1590 *
1591 * and we can't make sure that the bound is already attributed because
1592 * of possible cycles.
1593 *
1594 * Visitor method: Validate a type expression, if it is not null, catching
1595 * and reporting any completion failures.
1596 */
1597 void validate(JCTree tree, Env<AttrContext> env) {
1598 validate(tree, env, true);
1599 }
1600 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1601 new Validator(env).validateTree(tree, checkRaw, true);
1602 }
1603
1604 /** Visitor method: Validate a list of type expressions.
1605 */
1606 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1607 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1608 validate(l.head, env);
1609 }
1610
1611 /** A visitor class for type validation.
1612 */
1613 class Validator extends JCTree.Visitor {
1614
1615 boolean checkRaw;
1616 boolean isOuter;
1617 Env<AttrContext> env;
1618
1619 Validator(Env<AttrContext> env) {
1620 this.env = env;
1621 }
1622
1623 @Override
1624 public void visitTypeArray(JCArrayTypeTree tree) {
1625 validateTree(tree.elemtype, checkRaw, isOuter);
1626 }
1627
1628 @Override
1629 public void visitTypeApply(JCTypeApply tree) {
1630 if (tree.type.hasTag(CLASS)) {
1631 List<JCExpression> args = tree.arguments;
1632 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1633
1634 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1635 if (incompatibleArg != null) {
1636 for (JCTree arg : tree.arguments) {
1637 if (arg.type == incompatibleArg) {
1638 log.error(arg, Errors.NotWithinBounds(incompatibleArg, forms.head));
1639 }
1640 forms = forms.tail;
1641 }
1642 }
1643
1644 forms = tree.type.tsym.type.getTypeArguments();
1645
1646 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1647
1648 // For matching pairs of actual argument types `a' and
1649 // formal type parameters with declared bound `b' ...
1650 while (args.nonEmpty() && forms.nonEmpty()) {
1651 validateTree(args.head,
1652 !(isOuter && is_java_lang_Class),
1653 false);
1654 args = args.tail;
1655 forms = forms.tail;
1656 }
1657
1658 // Check that this type is either fully parameterized, or
1659 // not parameterized at all.
1660 if (tree.type.getEnclosingType().isRaw())
1661 log.error(tree.pos(), Errors.ImproperlyFormedTypeInnerRawParam);
1662 if (tree.clazz.hasTag(SELECT))
1663 visitSelectInternal((JCFieldAccess)tree.clazz);
1664 }
1665 }
1666
1667 @Override
1668 public void visitTypeParameter(JCTypeParameter tree) {
1669 validateTrees(tree.bounds, true, isOuter);
1670 checkClassBounds(tree.pos(), tree.type);
1671 }
1672
1673 @Override
1674 public void visitWildcard(JCWildcard tree) {
1675 if (tree.inner != null)
1676 validateTree(tree.inner, true, isOuter);
1677 }
1678
1679 @Override
1680 public void visitSelect(JCFieldAccess tree) {
1681 if (tree.type.hasTag(CLASS)) {
1682 visitSelectInternal(tree);
1683
1684 // Check that this type is either fully parameterized, or
1685 // not parameterized at all.
1686 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1687 log.error(tree.pos(), Errors.ImproperlyFormedTypeParamMissing);
1688 }
1689 }
1690
1691 public void visitSelectInternal(JCFieldAccess tree) {
1692 if (tree.type.tsym.isStatic() &&
1693 tree.selected.type.isParameterized() &&
1694 (tree.name != names.ref || !tree.type.isReferenceProjection())) {
1695 // The enclosing type is not a class, so we are
1696 // looking at a static member type. However, the
1697 // qualifying expression is parameterized.
1698 // Tolerate the pseudo-select V.ref: V<T>.ref will be static if V<T> is and
1699 // should not be confused as selecting a static member of a parameterized type.
1700 log.error(tree.pos(), Errors.CantSelectStaticClassFromParamType);
1701 } else {
1702 // otherwise validate the rest of the expression
1703 tree.selected.accept(this);
1704 }
1705 }
1706
1707 @Override
1708 public void visitAnnotatedType(JCAnnotatedType tree) {
1709 tree.underlyingType.accept(this);
1710 }
1711
1712 @Override
1713 public void visitTypeIdent(JCPrimitiveTypeTree that) {
1714 if (that.type.hasTag(TypeTag.VOID)) {
1715 log.error(that.pos(), Errors.VoidNotAllowedHere);
1716 }
1717 super.visitTypeIdent(that);
1718 }
1719
1720 /** Default visitor method: do nothing.
1721 */
1722 @Override
1723 public void visitTree(JCTree tree) {
1724 }
1725
1726 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1727 if (tree != null) {
1728 boolean prevCheckRaw = this.checkRaw;
1729 this.checkRaw = checkRaw;
1730 this.isOuter = isOuter;
1731
1732 try {
1733 tree.accept(this);
1734 if (checkRaw)
1735 checkRaw(tree, env);
1736 } catch (CompletionFailure ex) {
1737 completionError(tree.pos(), ex);
1738 } finally {
1739 this.checkRaw = prevCheckRaw;
1740 }
1741 }
1742 }
1743
1744 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1745 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1746 validateTree(l.head, checkRaw, isOuter);
1747 }
1748 }
1749
1750 void checkRaw(JCTree tree, Env<AttrContext> env) {
1751 if (lint.isEnabled(LintCategory.RAW) &&
1752 tree.type.hasTag(CLASS) &&
1753 !TreeInfo.isDiamond(tree) &&
1754 !withinAnonConstr(env) &&
1755 tree.type.isRaw()) {
1756 log.warning(LintCategory.RAW,
1757 tree.pos(), Warnings.RawClassUse(tree.type, tree.type.tsym.type));
1758 }
1759 }
1760 //where
1761 private boolean withinAnonConstr(Env<AttrContext> env) {
1762 return env.enclClass.name.isEmpty() &&
1763 env.enclMethod != null && env.enclMethod.name == names.init;
1764 }
1765
1766 /* *************************************************************************
1767 * Exception checking
1768 **************************************************************************/
1769
1770 /* The following methods treat classes as sets that contain
1771 * the class itself and all their subclasses
1772 */
1773
1774 /** Is given type a subtype of some of the types in given list?
1775 */
1776 boolean subset(Type t, List<Type> ts) {
1777 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1778 if (types.isSubtype(t, l.head)) return true;
1779 return false;
1780 }
1781
1782 /** Is given type a subtype or supertype of
1783 * some of the types in given list?
1784 */
1785 boolean intersects(Type t, List<Type> ts) {
1786 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1787 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1788 return false;
1789 }
1790
1791 /** Add type set to given type list, unless it is a subclass of some class
1792 * in the list.
1793 */
1794 List<Type> incl(Type t, List<Type> ts) {
1795 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1796 }
1797
1798 /** Remove type set from type set list.
1799 */
1800 List<Type> excl(Type t, List<Type> ts) {
1801 if (ts.isEmpty()) {
1802 return ts;
1803 } else {
1804 List<Type> ts1 = excl(t, ts.tail);
1805 if (types.isSubtype(ts.head, t)) return ts1;
1806 else if (ts1 == ts.tail) return ts;
1807 else return ts1.prepend(ts.head);
1808 }
1809 }
1810
1811 /** Form the union of two type set lists.
1812 */
1813 List<Type> union(List<Type> ts1, List<Type> ts2) {
1814 List<Type> ts = ts1;
1815 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1816 ts = incl(l.head, ts);
1817 return ts;
1818 }
1819
1820 /** Form the difference of two type lists.
1821 */
1822 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1823 List<Type> ts = ts1;
1824 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1825 ts = excl(l.head, ts);
1826 return ts;
1827 }
1828
1829 /** Form the intersection of two type lists.
1830 */
1831 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1832 List<Type> ts = List.nil();
1833 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1834 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1835 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1836 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1837 return ts;
1838 }
1839
1840 /** Is exc an exception symbol that need not be declared?
1841 */
1842 boolean isUnchecked(ClassSymbol exc) {
1843 return
1844 exc.kind == ERR ||
1845 exc.isSubClass(syms.errorType.tsym, types) ||
1846 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1847 }
1848
1849 /** Is exc an exception type that need not be declared?
1850 */
1851 boolean isUnchecked(Type exc) {
1852 return
1853 (exc.hasTag(TYPEVAR)) ? isUnchecked(types.supertype(exc)) :
1854 (exc.hasTag(CLASS)) ? isUnchecked((ClassSymbol)exc.tsym) :
1855 exc.hasTag(BOT);
1856 }
1857
1858 boolean isChecked(Type exc) {
1859 return !isUnchecked(exc);
1860 }
1861
1862 /** Same, but handling completion failures.
1863 */
1864 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1865 try {
1866 return isUnchecked(exc);
1867 } catch (CompletionFailure ex) {
1868 completionError(pos, ex);
1869 return true;
1870 }
1871 }
1872
1873 /** Is exc handled by given exception list?
1874 */
1875 boolean isHandled(Type exc, List<Type> handled) {
1876 return isUnchecked(exc) || subset(exc, handled);
1877 }
1878
1879 /** Return all exceptions in thrown list that are not in handled list.
1880 * @param thrown The list of thrown exceptions.
1881 * @param handled The list of handled exceptions.
1882 */
1883 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1884 List<Type> unhandled = List.nil();
1885 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1886 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1887 return unhandled;
1888 }
1889
1890 /* *************************************************************************
1891 * Overriding/Implementation checking
1892 **************************************************************************/
1893
1894 /** The level of access protection given by a flag set,
1895 * where PRIVATE is highest and PUBLIC is lowest.
1896 */
1897 static int protection(long flags) {
1898 switch ((short)(flags & AccessFlags)) {
1899 case PRIVATE: return 3;
1900 case PROTECTED: return 1;
1901 default:
1902 case PUBLIC: return 0;
1903 case 0: return 2;
1904 }
1905 }
1906
1907 /** A customized "cannot override" error message.
1908 * @param m The overriding method.
1909 * @param other The overridden method.
1910 * @return An internationalized string.
1911 */
1912 Fragment cannotOverride(MethodSymbol m, MethodSymbol other) {
1913 Symbol mloc = m.location();
1914 Symbol oloc = other.location();
1915
1916 if ((other.owner.flags() & INTERFACE) == 0)
1917 return Fragments.CantOverride(m, mloc, other, oloc);
1918 else if ((m.owner.flags() & INTERFACE) == 0)
1919 return Fragments.CantImplement(m, mloc, other, oloc);
1920 else
1921 return Fragments.ClashesWith(m, mloc, other, oloc);
1922 }
1923
1924 /** A customized "override" warning message.
1925 * @param m The overriding method.
1926 * @param other The overridden method.
1927 * @return An internationalized string.
1928 */
1929 Fragment uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1930 Symbol mloc = m.location();
1931 Symbol oloc = other.location();
1932
1933 if ((other.owner.flags() & INTERFACE) == 0)
1934 return Fragments.UncheckedOverride(m, mloc, other, oloc);
1935 else if ((m.owner.flags() & INTERFACE) == 0)
1936 return Fragments.UncheckedImplement(m, mloc, other, oloc);
1937 else
1938 return Fragments.UncheckedClashWith(m, mloc, other, oloc);
1939 }
1940
1941 /** A customized "override" warning message.
1942 * @param m The overriding method.
1943 * @param other The overridden method.
1944 * @return An internationalized string.
1945 */
1946 Fragment varargsOverrides(MethodSymbol m, MethodSymbol other) {
1947 Symbol mloc = m.location();
1948 Symbol oloc = other.location();
1949
1950 if ((other.owner.flags() & INTERFACE) == 0)
1951 return Fragments.VarargsOverride(m, mloc, other, oloc);
1952 else if ((m.owner.flags() & INTERFACE) == 0)
1953 return Fragments.VarargsImplement(m, mloc, other, oloc);
1954 else
1955 return Fragments.VarargsClashWith(m, mloc, other, oloc);
1956 }
1957
1958 /** Check that this method conforms with overridden method 'other'.
1959 * where `origin' is the class where checking started.
1960 * Complications:
1961 * (1) Do not check overriding of synthetic methods
1962 * (reason: they might be final).
1963 * todo: check whether this is still necessary.
1964 * (2) Admit the case where an interface proxy throws fewer exceptions
1965 * than the method it implements. Augment the proxy methods with the
1966 * undeclared exceptions in this case.
1967 * (3) When generics are enabled, admit the case where an interface proxy
1968 * has a result type
1969 * extended by the result type of the method it implements.
1970 * Change the proxies result type to the smaller type in this case.
1971 *
1972 * @param tree The tree from which positions
1973 * are extracted for errors.
1974 * @param m The overriding method.
1975 * @param other The overridden method.
1976 * @param origin The class of which the overriding method
1977 * is a member.
1978 */
1979 void checkOverride(JCTree tree,
1980 MethodSymbol m,
1981 MethodSymbol other,
1982 ClassSymbol origin) {
1983 // Don't check overriding of synthetic methods or by bridge methods.
1984 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1985 return;
1986 }
1987
1988 // Error if static method overrides instance method (JLS 8.4.6.2).
1989 if ((m.flags() & STATIC) != 0 &&
1990 (other.flags() & STATIC) == 0) {
1991 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1992 Errors.OverrideStatic(cannotOverride(m, other)));
1993 m.flags_field |= BAD_OVERRIDE;
1994 return;
1995 }
1996
1997 // Error if instance method overrides static or final
1998 // method (JLS 8.4.6.1).
1999 if ((other.flags() & FINAL) != 0 ||
2000 (m.flags() & STATIC) == 0 &&
2001 (other.flags() & STATIC) != 0) {
2002 log.error(TreeInfo.diagnosticPositionFor(m, tree),
2003 Errors.OverrideMeth(cannotOverride(m, other),
2004 asFlagSet(other.flags() & (FINAL | STATIC))));
2005 m.flags_field |= BAD_OVERRIDE;
2006 return;
2007 }
2008
2009 if ((m.owner.flags() & ANNOTATION) != 0) {
2010 // handled in validateAnnotationMethod
2011 return;
2012 }
2013
2014 // Error if overriding method has weaker access (JLS 8.4.6.3).
2015 if (protection(m.flags()) > protection(other.flags())) {
2016 log.error(TreeInfo.diagnosticPositionFor(m, tree),
2017 (other.flags() & AccessFlags) == 0 ?
2018 Errors.OverrideWeakerAccess(cannotOverride(m, other),
2019 "package") :
2020 Errors.OverrideWeakerAccess(cannotOverride(m, other),
2021 asFlagSet(other.flags() & AccessFlags)));
2022 m.flags_field |= BAD_OVERRIDE;
2023 return;
2024 }
2025
2026 if (origin.isValueClass() && other.owner == syms.objectType.tsym && m.type.getParameterTypes().size() == 0) {
2027 if (m.name == names.finalize) {
2028 log.error(TreeInfo.diagnosticPositionFor(m, tree),
2029 Errors.ValueClassMayNotOverride(m.name));
2030 m.flags_field |= BAD_OVERRIDE;
2031 return;
2032 }
2033 }
2034
2035 Type mt = types.memberType(origin.type, m);
2036 Type ot = types.memberType(origin.type, other);
2037 // Error if overriding result type is different
2038 // (or, in the case of generics mode, not a subtype) of
2039 // overridden result type. We have to rename any type parameters
2040 // before comparing types.
2041 List<Type> mtvars = mt.getTypeArguments();
2042 List<Type> otvars = ot.getTypeArguments();
2043 Type mtres = mt.getReturnType();
2044 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
2045
2046 overrideWarner.clear();
2047 boolean resultTypesOK =
2048 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
2049 if (!resultTypesOK) {
2050 if ((m.flags() & STATIC) != 0 && (other.flags() & STATIC) != 0) {
2051 log.error(TreeInfo.diagnosticPositionFor(m, tree),
2052 Errors.OverrideIncompatibleRet(Fragments.CantHide(m, m.location(), other,
2053 other.location()), mtres, otres));
2054 m.flags_field |= BAD_OVERRIDE;
2055 } else {
2056 log.error(TreeInfo.diagnosticPositionFor(m, tree),
2057 Errors.OverrideIncompatibleRet(cannotOverride(m, other), mtres, otres));
2058 m.flags_field |= BAD_OVERRIDE;
2059 }
2060 return;
2061 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
2062 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
2063 Warnings.OverrideUncheckedRet(uncheckedOverrides(m, other), mtres, otres));
2064 }
2065
2066 // Error if overriding method throws an exception not reported
2067 // by overridden method.
2068 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
2069 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
2070 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
2071 if (unhandledErased.nonEmpty()) {
2072 log.error(TreeInfo.diagnosticPositionFor(m, tree),
2073 Errors.OverrideMethDoesntThrow(cannotOverride(m, other), unhandledUnerased.head));
2074 m.flags_field |= BAD_OVERRIDE;
2075 return;
2076 }
2077 else if (unhandledUnerased.nonEmpty()) {
2078 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
2079 Warnings.OverrideUncheckedThrown(cannotOverride(m, other), unhandledUnerased.head));
2080 return;
2081 }
2082
2083 // Optional warning if varargs don't agree
2084 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
2085 && lint.isEnabled(LintCategory.OVERRIDES)) {
2086 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
2087 ((m.flags() & Flags.VARARGS) != 0)
2088 ? Warnings.OverrideVarargsMissing(varargsOverrides(m, other))
2089 : Warnings.OverrideVarargsExtra(varargsOverrides(m, other)));
2090 }
2091
2092 // Warn if instance method overrides bridge method (compiler spec ??)
2093 if ((other.flags() & BRIDGE) != 0) {
2094 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
2095 Warnings.OverrideBridge(uncheckedOverrides(m, other)));
2096 }
2097
2098 // Warn if a deprecated method overridden by a non-deprecated one.
2099 if (!isDeprecatedOverrideIgnorable(other, origin)) {
2100 Lint prevLint = setLint(lint.augment(m));
2101 try {
2102 checkDeprecated(() -> TreeInfo.diagnosticPositionFor(m, tree), m, other);
2103 } finally {
2104 setLint(prevLint);
2105 }
2106 }
2107 }
2108 // where
2109 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
2110 // If the method, m, is defined in an interface, then ignore the issue if the method
2111 // is only inherited via a supertype and also implemented in the supertype,
2112 // because in that case, we will rediscover the issue when examining the method
2113 // in the supertype.
2114 // If the method, m, is not defined in an interface, then the only time we need to
2115 // address the issue is when the method is the supertype implementation: any other
2116 // case, we will have dealt with when examining the supertype classes
2117 ClassSymbol mc = m.enclClass();
2118 Type st = types.supertype(origin.type);
2119 if (!st.hasTag(CLASS))
2120 return true;
2121 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
2122
2123 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
2124 List<Type> intfs = types.interfaces(origin.type);
2125 return (intfs.contains(mc.type) ? false : (stimpl != null));
2126 }
2127 else
2128 return (stimpl != m);
2129 }
2130
2131
2132 // used to check if there were any unchecked conversions
2133 Warner overrideWarner = new Warner();
2134
2135 /** Check that a class does not inherit two concrete methods
2136 * with the same signature.
2137 * @param pos Position to be used for error reporting.
2138 * @param site The class type to be checked.
2139 */
2140 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
2141 Type sup = types.supertype(site);
2142 if (!sup.hasTag(CLASS)) return;
2143
2144 for (Type t1 = sup;
2145 t1.hasTag(CLASS) && t1.tsym.type.isParameterized();
2146 t1 = types.supertype(t1)) {
2147 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
2148 if (s1.kind != MTH ||
2149 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
2150 !s1.isInheritedIn(site.tsym, types) ||
2151 ((MethodSymbol)s1).implementation(site.tsym,
2152 types,
2153 true) != s1)
2154 continue;
2155 Type st1 = types.memberType(t1, s1);
2156 int s1ArgsLength = st1.getParameterTypes().length();
2157 if (st1 == s1.type) continue;
2158
2159 for (Type t2 = sup;
2160 t2.hasTag(CLASS);
2161 t2 = types.supertype(t2)) {
2162 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
2163 if (s2 == s1 ||
2164 s2.kind != MTH ||
2165 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
2166 s2.type.getParameterTypes().length() != s1ArgsLength ||
2167 !s2.isInheritedIn(site.tsym, types) ||
2168 ((MethodSymbol)s2).implementation(site.tsym,
2169 types,
2170 true) != s2)
2171 continue;
2172 Type st2 = types.memberType(t2, s2);
2173 if (types.overrideEquivalent(st1, st2))
2174 log.error(pos,
2175 Errors.ConcreteInheritanceConflict(s1, t1, s2, t2, sup));
2176 }
2177 }
2178 }
2179 }
2180 }
2181
2182 /** Check that classes (or interfaces) do not each define an abstract
2183 * method with same name and arguments but incompatible return types.
2184 * @param pos Position to be used for error reporting.
2185 * @param t1 The first argument type.
2186 * @param t2 The second argument type.
2187 */
2188 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
2189 Type t1,
2190 Type t2,
2191 Type site) {
2192 if ((site.tsym.flags() & COMPOUND) != 0) {
2193 // special case for intersections: need to eliminate wildcards in supertypes
2194 t1 = types.capture(t1);
2195 t2 = types.capture(t2);
2196 }
2197 return firstIncompatibility(pos, t1, t2, site) == null;
2198 }
2199
2200 /** Return the first method which is defined with same args
2201 * but different return types in two given interfaces, or null if none
2202 * exists.
2203 * @param t1 The first type.
2204 * @param t2 The second type.
2205 * @param site The most derived type.
2206 * @return symbol from t2 that conflicts with one in t1.
2207 */
2208 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
2209 Map<TypeSymbol,Type> interfaces1 = new HashMap<>();
2210 closure(t1, interfaces1);
2211 Map<TypeSymbol,Type> interfaces2;
2212 if (t1 == t2)
2213 interfaces2 = interfaces1;
2214 else
2215 closure(t2, interfaces1, interfaces2 = new HashMap<>());
2216
2217 for (Type t3 : interfaces1.values()) {
2218 for (Type t4 : interfaces2.values()) {
2219 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
2220 if (s != null) return s;
2221 }
2222 }
2223 return null;
2224 }
2225
2226 /** Compute all the supertypes of t, indexed by type symbol. */
2227 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
2228 if (!t.hasTag(CLASS)) return;
2229 if (typeMap.put(t.tsym, t) == null) {
2230 closure(types.supertype(t), typeMap);
2231 for (Type i : types.interfaces(t))
2232 closure(i, typeMap);
2233 }
2234 }
2235
2236 /** Compute all the supertypes of t, indexed by type symbol (except those in typesSkip). */
2237 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
2238 if (!t.hasTag(CLASS)) return;
2239 if (typesSkip.get(t.tsym) != null) return;
2240 if (typeMap.put(t.tsym, t) == null) {
2241 closure(types.supertype(t), typesSkip, typeMap);
2242 for (Type i : types.interfaces(t))
2243 closure(i, typesSkip, typeMap);
2244 }
2245 }
2246
2247 /** Return the first method in t2 that conflicts with a method from t1. */
2248 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
2249 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) {
2250 Type st1 = null;
2251 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types) ||
2252 (s1.flags() & SYNTHETIC) != 0) continue;
2253 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
2254 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
2255 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) {
2256 if (s1 == s2) continue;
2257 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types) ||
2258 (s2.flags() & SYNTHETIC) != 0) continue;
2259 if (st1 == null) st1 = types.memberType(t1, s1);
2260 Type st2 = types.memberType(t2, s2);
2261 if (types.overrideEquivalent(st1, st2)) {
2262 List<Type> tvars1 = st1.getTypeArguments();
2263 List<Type> tvars2 = st2.getTypeArguments();
2264 Type rt1 = st1.getReturnType();
2265 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
2266 boolean compat =
2267 types.isSameType(rt1, rt2) ||
2268 !rt1.isPrimitiveOrVoid() &&
2269 !rt2.isPrimitiveOrVoid() &&
2270 (types.covariantReturnType(rt1, rt2, types.noWarnings) ||
2271 types.covariantReturnType(rt2, rt1, types.noWarnings)) ||
2272 checkCommonOverriderIn(s1,s2,site);
2273 if (!compat) {
2274 log.error(pos, Errors.TypesIncompatible(t1, t2,
2275 Fragments.IncompatibleDiffRet(s2.name, types.memberType(t2, s2).getParameterTypes())));
2276 return s2;
2277 }
2278 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) &&
2279 !checkCommonOverriderIn(s1, s2, site)) {
2280 log.error(pos, Errors.NameClashSameErasureNoOverride(
2281 s1.name, types.memberType(site, s1).asMethodType().getParameterTypes(), s1.location(),
2282 s2.name, types.memberType(site, s2).asMethodType().getParameterTypes(), s2.location()));
2283 return s2;
2284 }
2285 }
2286 }
2287 return null;
2288 }
2289 //WHERE
2290 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
2291 Map<TypeSymbol,Type> supertypes = new HashMap<>();
2292 Type st1 = types.memberType(site, s1);
2293 Type st2 = types.memberType(site, s2);
2294 closure(site, supertypes);
2295 for (Type t : supertypes.values()) {
2296 for (Symbol s3 : t.tsym.members().getSymbolsByName(s1.name)) {
2297 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
2298 Type st3 = types.memberType(site,s3);
2299 if (types.overrideEquivalent(st3, st1) &&
2300 types.overrideEquivalent(st3, st2) &&
2301 types.returnTypeSubstitutable(st3, st1) &&
2302 types.returnTypeSubstitutable(st3, st2)) {
2303 return true;
2304 }
2305 }
2306 }
2307 return false;
2308 }
2309
2310 /** Check that a given method conforms with any method it overrides.
2311 * @param tree The tree from which positions are extracted
2312 * for errors.
2313 * @param m The overriding method.
2314 */
2315 void checkOverride(Env<AttrContext> env, JCMethodDecl tree, MethodSymbol m) {
2316 ClassSymbol origin = (ClassSymbol)m.owner;
2317 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name)) {
2318 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
2319 log.error(tree.pos(), Errors.EnumNoFinalize);
2320 return;
2321 }
2322 }
2323 if (allowRecords && origin.isRecord()) {
2324 // let's find out if this is a user defined accessor in which case the @Override annotation is acceptable
2325 Optional<? extends RecordComponent> recordComponent = origin.getRecordComponents().stream()
2326 .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst();
2327 if (recordComponent.isPresent()) {
2328 return;
2329 }
2330 }
2331
2332 for (Type t = origin.type; t.hasTag(CLASS);
2333 t = types.supertype(t)) {
2334 if (t != origin.type) {
2335 checkOverride(tree, t, origin, m);
2336 }
2337 for (Type t2 : types.interfaces(t)) {
2338 checkOverride(tree, t2, origin, m);
2339 }
2340 }
2341
2342 final boolean explicitOverride = m.attribute(syms.overrideType.tsym) != null;
2343 // Check if this method must override a super method due to being annotated with @Override
2344 // or by virtue of being a member of a diamond inferred anonymous class. Latter case is to
2345 // be treated "as if as they were annotated" with @Override.
2346 boolean mustOverride = explicitOverride ||
2347 (env.info.isAnonymousDiamond && !m.isConstructor() && !m.isPrivate() &&
2348 (!m.owner.isPrimitiveClass() || (tree.body.flags & SYNTHETIC) == 0));
2349 if (mustOverride && !isOverrider(m)) {
2350 DiagnosticPosition pos = tree.pos();
2351 for (JCAnnotation a : tree.getModifiers().annotations) {
2352 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2353 pos = a.pos();
2354 break;
2355 }
2356 }
2357 log.error(pos,
2358 explicitOverride ? (m.isStatic() ? Errors.StaticMethodsCannotBeAnnotatedWithOverride : Errors.MethodDoesNotOverrideSuperclass) :
2359 Errors.AnonymousDiamondMethodDoesNotOverrideSuperclass(Fragments.DiamondAnonymousMethodsImplicitlyOverride));
2360 }
2361 }
2362
2363 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
2364 TypeSymbol c = site.tsym;
2365 for (Symbol sym : c.members().getSymbolsByName(m.name)) {
2366 if (m.overrides(sym, origin, types, false)) {
2367 if ((sym.flags() & ABSTRACT) == 0) {
2368 checkOverride(tree, m, (MethodSymbol)sym, origin);
2369 }
2370 }
2371 }
2372 }
2373
2374 private Predicate<Symbol> equalsHasCodeFilter = s -> MethodSymbol.implementation_filter.test(s) &&
2375 (s.flags() & BAD_OVERRIDE) == 0;
2376
2377 public void checkClassOverrideEqualsAndHashIfNeeded(DiagnosticPosition pos,
2378 ClassSymbol someClass) {
2379 /* At present, annotations cannot possibly have a method that is override
2380 * equivalent with Object.equals(Object) but in any case the condition is
2381 * fine for completeness.
2382 */
2383 if (someClass == (ClassSymbol)syms.objectType.tsym ||
2384 someClass.isInterface() || someClass.isEnum() ||
2385 (someClass.flags() & ANNOTATION) != 0 ||
2386 (someClass.flags() & ABSTRACT) != 0) return;
2387 //anonymous inner classes implementing interfaces need especial treatment
2388 if (someClass.isAnonymous()) {
2389 List<Type> interfaces = types.interfaces(someClass.type);
2390 if (interfaces != null && !interfaces.isEmpty() &&
2391 interfaces.head.tsym == syms.comparatorType.tsym) return;
2392 }
2393 checkClassOverrideEqualsAndHash(pos, someClass);
2394 }
2395
2396 private void checkClassOverrideEqualsAndHash(DiagnosticPosition pos,
2397 ClassSymbol someClass) {
2398 if (lint.isEnabled(LintCategory.OVERRIDES)) {
2399 MethodSymbol equalsAtObject = (MethodSymbol)syms.objectType
2400 .tsym.members().findFirst(names.equals);
2401 MethodSymbol hashCodeAtObject = (MethodSymbol)syms.objectType
2402 .tsym.members().findFirst(names.hashCode);
2403 MethodSymbol equalsImpl = types.implementation(equalsAtObject,
2404 someClass, false, equalsHasCodeFilter);
2405 boolean overridesEquals = equalsImpl != null &&
2406 equalsImpl.owner == someClass;
2407 boolean overridesHashCode = types.implementation(hashCodeAtObject,
2408 someClass, false, equalsHasCodeFilter) != hashCodeAtObject;
2409
2410 if (overridesEquals && !overridesHashCode) {
2411 log.warning(LintCategory.OVERRIDES, pos,
2412 Warnings.OverrideEqualsButNotHashcode(someClass));
2413 }
2414 }
2415 }
2416
2417 public void checkModuleName (JCModuleDecl tree) {
2418 Name moduleName = tree.sym.name;
2419 Assert.checkNonNull(moduleName);
2420 if (lint.isEnabled(LintCategory.MODULE)) {
2421 JCExpression qualId = tree.qualId;
2422 while (qualId != null) {
2423 Name componentName;
2424 DiagnosticPosition pos;
2425 switch (qualId.getTag()) {
2426 case SELECT:
2427 JCFieldAccess selectNode = ((JCFieldAccess) qualId);
2428 componentName = selectNode.name;
2429 pos = selectNode.pos();
2430 qualId = selectNode.selected;
2431 break;
2432 case IDENT:
2433 componentName = ((JCIdent) qualId).name;
2434 pos = qualId.pos();
2435 qualId = null;
2436 break;
2437 default:
2438 throw new AssertionError("Unexpected qualified identifier: " + qualId.toString());
2439 }
2440 if (componentName != null) {
2441 String moduleNameComponentString = componentName.toString();
2442 int nameLength = moduleNameComponentString.length();
2443 if (nameLength > 0 && Character.isDigit(moduleNameComponentString.charAt(nameLength - 1))) {
2444 log.warning(Lint.LintCategory.MODULE, pos, Warnings.PoorChoiceForModuleName(componentName));
2445 }
2446 }
2447 }
2448 }
2449 }
2450
2451 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
2452 ClashFilter cf = new ClashFilter(origin.type);
2453 return (cf.test(s1) &&
2454 cf.test(s2) &&
2455 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
2456 }
2457
2458
2459 /** Check that all abstract members of given class have definitions.
2460 * @param pos Position to be used for error reporting.
2461 * @param c The class.
2462 */
2463 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
2464 MethodSymbol undef = types.firstUnimplementedAbstract(c);
2465 if (undef != null) {
2466 MethodSymbol undef1 =
2467 new MethodSymbol(undef.flags(), undef.name,
2468 types.memberType(c.type, undef), undef.owner);
2469 log.error(pos,
2470 Errors.DoesNotOverrideAbstract(c, undef1, undef1.location()));
2471 }
2472 }
2473
2474 // A primitive class cannot contain a field of its own type either or indirectly.
2475 void checkNonCyclicMembership(JCClassDecl tree) {
2476 Assert.check((tree.sym.flags_field & LOCKED) == 0);
2477 try {
2478 tree.sym.flags_field |= LOCKED;
2479 for (List<? extends JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2480 if (l.head.hasTag(VARDEF)) {
2481 JCVariableDecl field = (JCVariableDecl) l.head;
2482 if (cyclePossible(field.sym)) {
2483 checkNonCyclicMembership((ClassSymbol) field.type.tsym, field.pos());
2484 }
2485 }
2486 }
2487 } finally {
2488 tree.sym.flags_field &= ~LOCKED;
2489 }
2490
2491 }
2492 // where
2493 private void checkNonCyclicMembership(ClassSymbol c, DiagnosticPosition pos) {
2494 if ((c.flags_field & LOCKED) != 0) {
2495 log.error(pos, Errors.CyclicPrimitiveClassMembership(c));
2496 return;
2497 }
2498 try {
2499 c.flags_field |= LOCKED;
2500 for (Symbol fld : c.members().getSymbols(s -> s.kind == VAR && cyclePossible((VarSymbol) s), NON_RECURSIVE)) {
2501 checkNonCyclicMembership((ClassSymbol) fld.type.tsym, pos);
2502 }
2503 } finally {
2504 c.flags_field &= ~LOCKED;
2505 }
2506 }
2507 // where
2508 private boolean cyclePossible(VarSymbol symbol) {
2509 return (symbol.flags() & STATIC) == 0 && types.isPrimitiveClass(symbol.type);
2510 }
2511
2512 void checkNonCyclicDecl(JCClassDecl tree) {
2513 CycleChecker cc = new CycleChecker();
2514 cc.scan(tree);
2515 if (!cc.errorFound && !cc.partialCheck) {
2516 tree.sym.flags_field |= ACYCLIC;
2517 }
2518 }
2519
2520 class CycleChecker extends TreeScanner {
2521
2522 Set<Symbol> seenClasses = new HashSet<>();
2523 boolean errorFound = false;
2524 boolean partialCheck = false;
2525
2526 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
2527 if (sym != null && sym.kind == TYP) {
2528 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
2529 if (classEnv != null) {
2530 DiagnosticSource prevSource = log.currentSource();
2531 try {
2532 log.useSource(classEnv.toplevel.sourcefile);
2533 scan(classEnv.tree);
2534 }
2535 finally {
2536 log.useSource(prevSource.getFile());
2537 }
2538 } else if (sym.kind == TYP) {
2539 checkClass(pos, sym, List.nil());
2540 }
2541 } else if (sym == null || sym.kind != PCK) {
2542 //not completed yet
2543 partialCheck = true;
2544 }
2545 }
2546
2547 @Override
2548 public void visitSelect(JCFieldAccess tree) {
2549 super.visitSelect(tree);
2550 checkSymbol(tree.pos(), tree.sym);
2551 }
2552
2553 @Override
2554 public void visitIdent(JCIdent tree) {
2555 checkSymbol(tree.pos(), tree.sym);
2556 }
2557
2558 @Override
2559 public void visitTypeApply(JCTypeApply tree) {
2560 scan(tree.clazz);
2561 }
2562
2563 @Override
2564 public void visitTypeArray(JCArrayTypeTree tree) {
2565 scan(tree.elemtype);
2566 }
2567
2568 @Override
2569 public void visitClassDef(JCClassDecl tree) {
2570 List<JCTree> supertypes = List.nil();
2571 if (tree.getExtendsClause() != null) {
2572 supertypes = supertypes.prepend(tree.getExtendsClause());
2573 }
2574 if (tree.getImplementsClause() != null) {
2575 for (JCTree intf : tree.getImplementsClause()) {
2576 supertypes = supertypes.prepend(intf);
2577 }
2578 }
2579 checkClass(tree.pos(), tree.sym, supertypes);
2580 }
2581
2582 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
2583 if ((c.flags_field & ACYCLIC) != 0)
2584 return;
2585 if (seenClasses.contains(c)) {
2586 errorFound = true;
2587 noteCyclic(pos, (ClassSymbol)c);
2588 } else if (!c.type.isErroneous()) {
2589 try {
2590 seenClasses.add(c);
2591 if (c.type.hasTag(CLASS)) {
2592 if (supertypes.nonEmpty()) {
2593 scan(supertypes);
2594 }
2595 else {
2596 ClassType ct = (ClassType)c.type;
2597 if (ct.supertype_field == null ||
2598 ct.interfaces_field == null) {
2599 //not completed yet
2600 partialCheck = true;
2601 return;
2602 }
2603 checkSymbol(pos, ct.supertype_field.tsym);
2604 for (Type intf : ct.interfaces_field) {
2605 checkSymbol(pos, intf.tsym);
2606 }
2607 }
2608 if (c.owner.kind == TYP) {
2609 checkSymbol(pos, c.owner);
2610 }
2611 }
2612 } finally {
2613 seenClasses.remove(c);
2614 }
2615 }
2616 }
2617 }
2618
2619 /** Check for cyclic references. Issue an error if the
2620 * symbol of the type referred to has a LOCKED flag set.
2621 *
2622 * @param pos Position to be used for error reporting.
2623 * @param t The type referred to.
2624 */
2625 void checkNonCyclic(DiagnosticPosition pos, Type t) {
2626 checkNonCyclicInternal(pos, t);
2627 }
2628
2629
2630 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
2631 checkNonCyclic1(pos, t, List.nil());
2632 }
2633
2634 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
2635 final TypeVar tv;
2636 if (t.hasTag(TYPEVAR) && (t.tsym.flags() & UNATTRIBUTED) != 0)
2637 return;
2638 if (seen.contains(t)) {
2639 tv = (TypeVar)t;
2640 tv.setUpperBound(types.createErrorType(t));
2641 log.error(pos, Errors.CyclicInheritance(t));
2642 } else if (t.hasTag(TYPEVAR)) {
2643 tv = (TypeVar)t;
2644 seen = seen.prepend(tv);
2645 for (Type b : types.getBounds(tv))
2646 checkNonCyclic1(pos, b, seen);
2647 }
2648 }
2649
2650 /** Check for cyclic references. Issue an error if the
2651 * symbol of the type referred to has a LOCKED flag set.
2652 *
2653 * @param pos Position to be used for error reporting.
2654 * @param t The type referred to.
2655 * @returns True if the check completed on all attributed classes
2656 */
2657 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
2658 boolean complete = true; // was the check complete?
2659 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
2660 Symbol c = t.tsym;
2661 if ((c.flags_field & ACYCLIC) != 0) return true;
2662
2663 if ((c.flags_field & LOCKED) != 0) {
2664 noteCyclic(pos, (ClassSymbol)c);
2665 } else if (!c.type.isErroneous()) {
2666 try {
2667 c.flags_field |= LOCKED;
2668 if (c.type.hasTag(CLASS)) {
2669 ClassType clazz = (ClassType)c.type;
2670 if (clazz.interfaces_field != null)
2671 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
2672 complete &= checkNonCyclicInternal(pos, l.head);
2673 if (clazz.supertype_field != null) {
2674 Type st = clazz.supertype_field;
2675 if (st != null && st.hasTag(CLASS))
2676 complete &= checkNonCyclicInternal(pos, st);
2677 }
2678 if (c.owner.kind == TYP)
2679 complete &= checkNonCyclicInternal(pos, c.owner.type);
2680 }
2681 } finally {
2682 c.flags_field &= ~LOCKED;
2683 }
2684 }
2685 if (complete)
2686 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.isCompleted();
2687 if (complete) c.flags_field |= ACYCLIC;
2688 return complete;
2689 }
2690
2691 /** Note that we found an inheritance cycle. */
2692 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
2693 log.error(pos, Errors.CyclicInheritance(c));
2694 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2695 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2696 Type st = types.supertype(c.type);
2697 if (st.hasTag(CLASS))
2698 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2699 c.type = types.createErrorType(c, c.type);
2700 c.flags_field |= ACYCLIC;
2701 }
2702
2703 /** Check that all methods which implement some
2704 * method conform to the method they implement.
2705 * @param tree The class definition whose members are checked.
2706 */
2707 void checkImplementations(JCClassDecl tree) {
2708 checkImplementations(tree, tree.sym, tree.sym);
2709 }
2710 //where
2711 /** Check that all methods which implement some
2712 * method in `ic' conform to the method they implement.
2713 */
2714 void checkImplementations(JCTree tree, ClassSymbol origin, ClassSymbol ic) {
2715 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2716 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2717 if ((lc.flags() & ABSTRACT) != 0) {
2718 for (Symbol sym : lc.members().getSymbols(NON_RECURSIVE)) {
2719 if (sym.kind == MTH &&
2720 (sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2721 MethodSymbol absmeth = (MethodSymbol)sym;
2722 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2723 if (implmeth != null && implmeth != absmeth &&
2724 (implmeth.owner.flags() & INTERFACE) ==
2725 (origin.flags() & INTERFACE)) {
2726 // don't check if implmeth is in a class, yet
2727 // origin is an interface. This case arises only
2728 // if implmeth is declared in Object. The reason is
2729 // that interfaces really don't inherit from
2730 // Object it's just that the compiler represents
2731 // things that way.
2732 checkOverride(tree, implmeth, absmeth, origin);
2733 }
2734 }
2735 }
2736 }
2737 }
2738 }
2739
2740 /** Check that all abstract methods implemented by a class are
2741 * mutually compatible.
2742 * @param pos Position to be used for error reporting.
2743 * @param c The class whose interfaces are checked.
2744 */
2745 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2746 List<Type> supertypes = types.interfaces(c);
2747 Type supertype = types.supertype(c);
2748 if (supertype.hasTag(CLASS) &&
2749 (supertype.tsym.flags() & ABSTRACT) != 0)
2750 supertypes = supertypes.prepend(supertype);
2751 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2752 if (!l.head.getTypeArguments().isEmpty() &&
2753 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2754 return;
2755 for (List<Type> m = supertypes; m != l; m = m.tail)
2756 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2757 return;
2758 }
2759 checkCompatibleConcretes(pos, c);
2760
2761 boolean implementsIdentityObject = types.asSuper(c.referenceProjectionOrSelf(), syms.identityObjectType.tsym) != null;
2762 boolean implementsValueObject = types.asSuper(c.referenceProjectionOrSelf(), syms.valueObjectType.tsym) != null;
2763 if (c.isValueClass() && implementsIdentityObject) {
2764 log.error(pos, Errors.ValueClassMustNotImplementIdentityObject(c));
2765 } else if (implementsValueObject && !c.isValueClass() && !c.isReferenceProjection() && !c.tsym.isInterface() && !c.tsym.isAbstract()) {
2766 log.error(pos, Errors.IdentityClassMustNotImplementValueObject(c));
2767 } else if (implementsValueObject && implementsIdentityObject) {
2768 log.error(pos, Errors.MutuallyIncompatibleSuperInterfaces(c));
2769 }
2770 }
2771
2772 /** Check that all non-override equivalent methods accessible from 'site'
2773 * are mutually compatible (JLS 8.4.8/9.4.1).
2774 *
2775 * @param pos Position to be used for error reporting.
2776 * @param site The class whose methods are checked.
2777 * @param sym The method symbol to be checked.
2778 */
2779 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2780 ClashFilter cf = new ClashFilter(site);
2781 //for each method m1 that is overridden (directly or indirectly)
2782 //by method 'sym' in 'site'...
2783
2784 List<MethodSymbol> potentiallyAmbiguousList = List.nil();
2785 boolean overridesAny = false;
2786 ArrayList<Symbol> symbolsByName = new ArrayList<>();
2787 types.membersClosure(site, false).getSymbolsByName(sym.name, cf).forEach(symbolsByName::add);
2788 for (Symbol m1 : symbolsByName) {
2789 if (!sym.overrides(m1, site.tsym, types, false)) {
2790 if (m1 == sym) {
2791 continue;
2792 }
2793
2794 if (!overridesAny) {
2795 potentiallyAmbiguousList = potentiallyAmbiguousList.prepend((MethodSymbol)m1);
2796 }
2797 continue;
2798 }
2799
2800 if (m1 != sym) {
2801 overridesAny = true;
2802 potentiallyAmbiguousList = List.nil();
2803 }
2804
2805 //...check each method m2 that is a member of 'site'
2806 for (Symbol m2 : symbolsByName) {
2807 if (m2 == m1) continue;
2808 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2809 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2810 if (!types.isSubSignature(sym.type, types.memberType(site, m2), Feature.STRICT_METHOD_CLASH_CHECK.allowedInSource(source)) &&
2811 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) {
2812 sym.flags_field |= CLASH;
2813 if (m1 == sym) {
2814 log.error(pos, Errors.NameClashSameErasureNoOverride(
2815 m1.name, types.memberType(site, m1).asMethodType().getParameterTypes(), m1.location(),
2816 m2.name, types.memberType(site, m2).asMethodType().getParameterTypes(), m2.location()));
2817 } else {
2818 ClassType ct = (ClassType)site;
2819 String kind = ct.isInterface() ? "interface" : "class";
2820 log.error(pos, Errors.NameClashSameErasureNoOverride1(
2821 kind,
2822 ct.tsym.name,
2823 m1.name,
2824 types.memberType(site, m1).asMethodType().getParameterTypes(),
2825 m1.location(),
2826 m2.name,
2827 types.memberType(site, m2).asMethodType().getParameterTypes(),
2828 m2.location()));
2829 }
2830 return;
2831 }
2832 }
2833 }
2834
2835 if (!overridesAny) {
2836 for (MethodSymbol m: potentiallyAmbiguousList) {
2837 checkPotentiallyAmbiguousOverloads(pos, site, sym, m);
2838 }
2839 }
2840 }
2841
2842 /** Check that all static methods accessible from 'site' are
2843 * mutually compatible (JLS 8.4.8).
2844 *
2845 * @param pos Position to be used for error reporting.
2846 * @param site The class whose methods are checked.
2847 * @param sym The method symbol to be checked.
2848 */
2849 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2850 ClashFilter cf = new ClashFilter(site);
2851 //for each method m1 that is a member of 'site'...
2852 for (Symbol s : types.membersClosure(site, true).getSymbolsByName(sym.name, cf)) {
2853 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2854 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2855 if (!types.isSubSignature(sym.type, types.memberType(site, s), Feature.STRICT_METHOD_CLASH_CHECK.allowedInSource(source))) {
2856 if (types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2857 log.error(pos,
2858 Errors.NameClashSameErasureNoHide(sym, sym.location(), s, s.location()));
2859 return;
2860 } else {
2861 checkPotentiallyAmbiguousOverloads(pos, site, sym, (MethodSymbol)s);
2862 }
2863 }
2864 }
2865 }
2866
2867 //where
2868 private class ClashFilter implements Predicate<Symbol> {
2869
2870 Type site;
2871
2872 ClashFilter(Type site) {
2873 this.site = site;
2874 }
2875
2876 boolean shouldSkip(Symbol s) {
2877 return (s.flags() & CLASH) != 0 &&
2878 s.owner == site.tsym;
2879 }
2880
2881 @Override
2882 public boolean test(Symbol s) {
2883 return s.kind == MTH &&
2884 (s.flags() & SYNTHETIC) == 0 &&
2885 !shouldSkip(s) &&
2886 s.isInheritedIn(site.tsym, types) &&
2887 !s.isConstructor();
2888 }
2889 }
2890
2891 void checkDefaultMethodClashes(DiagnosticPosition pos, Type site) {
2892 DefaultMethodClashFilter dcf = new DefaultMethodClashFilter(site);
2893 for (Symbol m : types.membersClosure(site, false).getSymbols(dcf)) {
2894 Assert.check(m.kind == MTH);
2895 List<MethodSymbol> prov = types.interfaceCandidates(site, (MethodSymbol)m);
2896 if (prov.size() > 1) {
2897 ListBuffer<Symbol> abstracts = new ListBuffer<>();
2898 ListBuffer<Symbol> defaults = new ListBuffer<>();
2899 for (MethodSymbol provSym : prov) {
2900 if ((provSym.flags() & DEFAULT) != 0) {
2901 defaults = defaults.append(provSym);
2902 } else if ((provSym.flags() & ABSTRACT) != 0) {
2903 abstracts = abstracts.append(provSym);
2904 }
2905 if (defaults.nonEmpty() && defaults.size() + abstracts.size() >= 2) {
2906 //strong semantics - issue an error if two sibling interfaces
2907 //have two override-equivalent defaults - or if one is abstract
2908 //and the other is default
2909 Fragment diagKey;
2910 Symbol s1 = defaults.first();
2911 Symbol s2;
2912 if (defaults.size() > 1) {
2913 s2 = defaults.toList().tail.head;
2914 diagKey = Fragments.IncompatibleUnrelatedDefaults(Kinds.kindName(site.tsym), site,
2915 m.name, types.memberType(site, m).getParameterTypes(),
2916 s1.location(), s2.location());
2917
2918 } else {
2919 s2 = abstracts.first();
2920 diagKey = Fragments.IncompatibleAbstractDefault(Kinds.kindName(site.tsym), site,
2921 m.name, types.memberType(site, m).getParameterTypes(),
2922 s1.location(), s2.location());
2923 }
2924 log.error(pos, Errors.TypesIncompatible(s1.location().type, s2.location().type, diagKey));
2925 break;
2926 }
2927 }
2928 }
2929 }
2930 }
2931
2932 //where
2933 private class DefaultMethodClashFilter implements Predicate<Symbol> {
2934
2935 Type site;
2936
2937 DefaultMethodClashFilter(Type site) {
2938 this.site = site;
2939 }
2940
2941 @Override
2942 public boolean test(Symbol s) {
2943 return s.kind == MTH &&
2944 (s.flags() & DEFAULT) != 0 &&
2945 s.isInheritedIn(site.tsym, types) &&
2946 !s.isConstructor();
2947 }
2948 }
2949
2950 /**
2951 * Report warnings for potentially ambiguous method declarations. Two declarations
2952 * are potentially ambiguous if they feature two unrelated functional interface
2953 * in same argument position (in which case, a call site passing an implicit
2954 * lambda would be ambiguous).
2955 */
2956 void checkPotentiallyAmbiguousOverloads(DiagnosticPosition pos, Type site,
2957 MethodSymbol msym1, MethodSymbol msym2) {
2958 if (msym1 != msym2 &&
2959 Feature.DEFAULT_METHODS.allowedInSource(source) &&
2960 lint.isEnabled(LintCategory.OVERLOADS) &&
2961 (msym1.flags() & POTENTIALLY_AMBIGUOUS) == 0 &&
2962 (msym2.flags() & POTENTIALLY_AMBIGUOUS) == 0) {
2963 Type mt1 = types.memberType(site, msym1);
2964 Type mt2 = types.memberType(site, msym2);
2965 //if both generic methods, adjust type variables
2966 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL) &&
2967 types.hasSameBounds((ForAll)mt1, (ForAll)mt2)) {
2968 mt2 = types.subst(mt2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
2969 }
2970 //expand varargs methods if needed
2971 int maxLength = Math.max(mt1.getParameterTypes().length(), mt2.getParameterTypes().length());
2972 List<Type> args1 = rs.adjustArgs(mt1.getParameterTypes(), msym1, maxLength, true);
2973 List<Type> args2 = rs.adjustArgs(mt2.getParameterTypes(), msym2, maxLength, true);
2974 //if arities don't match, exit
2975 if (args1.length() != args2.length()) return;
2976 boolean potentiallyAmbiguous = false;
2977 while (args1.nonEmpty() && args2.nonEmpty()) {
2978 Type s = args1.head;
2979 Type t = args2.head;
2980 if (!types.isSubtype(t, s) && !types.isSubtype(s, t)) {
2981 if (types.isFunctionalInterface(s) && types.isFunctionalInterface(t) &&
2982 types.findDescriptorType(s).getParameterTypes().length() > 0 &&
2983 types.findDescriptorType(s).getParameterTypes().length() ==
2984 types.findDescriptorType(t).getParameterTypes().length()) {
2985 potentiallyAmbiguous = true;
2986 } else {
2987 return;
2988 }
2989 }
2990 args1 = args1.tail;
2991 args2 = args2.tail;
2992 }
2993 if (potentiallyAmbiguous) {
2994 //we found two incompatible functional interfaces with same arity
2995 //this means a call site passing an implicit lambda would be ambiguous
2996 msym1.flags_field |= POTENTIALLY_AMBIGUOUS;
2997 msym2.flags_field |= POTENTIALLY_AMBIGUOUS;
2998 log.warning(LintCategory.OVERLOADS, pos,
2999 Warnings.PotentiallyAmbiguousOverload(msym1, msym1.location(),
3000 msym2, msym2.location()));
3001 return;
3002 }
3003 }
3004 }
3005
3006 void checkAccessFromSerializableElement(final JCTree tree, boolean isLambda) {
3007 if (warnOnAnyAccessToMembers ||
3008 (lint.isEnabled(LintCategory.SERIAL) &&
3009 !lint.isSuppressed(LintCategory.SERIAL) &&
3010 isLambda)) {
3011 Symbol sym = TreeInfo.symbol(tree);
3012 if (!sym.kind.matches(KindSelector.VAL_MTH)) {
3013 return;
3014 }
3015
3016 if (sym.kind == VAR) {
3017 if ((sym.flags() & PARAMETER) != 0 ||
3018 sym.isDirectlyOrIndirectlyLocal() ||
3019 sym.name == names._this ||
3020 sym.name == names._super) {
3021 return;
3022 }
3023 }
3024
3025 if (!types.isSubtype(sym.owner.type, syms.serializableType) &&
3026 isEffectivelyNonPublic(sym)) {
3027 if (isLambda) {
3028 if (belongsToRestrictedPackage(sym)) {
3029 log.warning(LintCategory.SERIAL, tree.pos(),
3030 Warnings.AccessToMemberFromSerializableLambda(sym));
3031 }
3032 } else {
3033 log.warning(tree.pos(),
3034 Warnings.AccessToMemberFromSerializableElement(sym));
3035 }
3036 }
3037 }
3038 }
3039
3040 private boolean isEffectivelyNonPublic(Symbol sym) {
3041 if (sym.packge() == syms.rootPackage) {
3042 return false;
3043 }
3044
3045 while (sym.kind != PCK) {
3046 if ((sym.flags() & PUBLIC) == 0) {
3047 return true;
3048 }
3049 sym = sym.owner;
3050 }
3051 return false;
3052 }
3053
3054 private boolean belongsToRestrictedPackage(Symbol sym) {
3055 String fullName = sym.packge().fullname.toString();
3056 return fullName.startsWith("java.") ||
3057 fullName.startsWith("javax.") ||
3058 fullName.startsWith("sun.") ||
3059 fullName.contains(".internal.");
3060 }
3061
3062 /** Check that class c does not implement directly or indirectly
3063 * the same parameterized interface with two different argument lists.
3064 * @param pos Position to be used for error reporting.
3065 * @param type The type whose interfaces are checked.
3066 */
3067 void checkClassBounds(DiagnosticPosition pos, Type type) {
3068 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
3069 }
3070 //where
3071 /** Enter all interfaces of type `type' into the hash table `seensofar'
3072 * with their class symbol as key and their type as value. Make
3073 * sure no class is entered with two different types.
3074 */
3075 void checkClassBounds(DiagnosticPosition pos,
3076 Map<TypeSymbol,Type> seensofar,
3077 Type type) {
3078 if (type.isErroneous()) return;
3079 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
3080 Type it = l.head;
3081 if (type.hasTag(CLASS) && !it.hasTag(CLASS)) continue; // JLS 8.1.5
3082
3083 Type oldit = seensofar.put(it.tsym, it);
3084 if (oldit != null) {
3085 List<Type> oldparams = oldit.allparams();
3086 List<Type> newparams = it.allparams();
3087 if (!types.containsTypeEquivalent(oldparams, newparams))
3088 log.error(pos,
3089 Errors.CantInheritDiffArg(it.tsym,
3090 Type.toString(oldparams),
3091 Type.toString(newparams)));
3092 }
3093 checkClassBounds(pos, seensofar, it);
3094 }
3095 Type st = types.supertype(type);
3096 if (type.hasTag(CLASS) && !st.hasTag(CLASS)) return; // JLS 8.1.4
3097 if (st != Type.noType) checkClassBounds(pos, seensofar, st);
3098 }
3099
3100 /** Enter interface into into set.
3101 * If it existed already, issue a "repeated interface" error.
3102 */
3103 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
3104 if (its.contains(it))
3105 log.error(pos, Errors.RepeatedInterface);
3106 else {
3107 its.add(it);
3108 }
3109 }
3110
3111 /* *************************************************************************
3112 * Check annotations
3113 **************************************************************************/
3114
3115 /**
3116 * Recursively validate annotations values
3117 */
3118 void validateAnnotationTree(JCTree tree) {
3119 class AnnotationValidator extends TreeScanner {
3120 @Override
3121 public void visitAnnotation(JCAnnotation tree) {
3122 if (!tree.type.isErroneous() && tree.type.tsym.isAnnotationType()) {
3123 super.visitAnnotation(tree);
3124 validateAnnotation(tree);
3125 }
3126 }
3127 }
3128 tree.accept(new AnnotationValidator());
3129 }
3130
3131 /**
3132 * {@literal
3133 * Annotation types are restricted to primitives, String, an
3134 * enum, an annotation, Class, Class<?>, Class<? extends
3135 * Anything>, arrays of the preceding.
3136 * }
3137 */
3138 void validateAnnotationType(JCTree restype) {
3139 // restype may be null if an error occurred, so don't bother validating it
3140 if (restype != null) {
3141 validateAnnotationType(restype.pos(), restype.type);
3142 }
3143 }
3144
3145 void validateAnnotationType(DiagnosticPosition pos, Type type) {
3146 if (type.isPrimitive()) return;
3147 if (types.isSameType(type, syms.stringType)) return;
3148 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
3149 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
3150 if (types.cvarLowerBound(type).tsym == syms.classType.tsym) return;
3151 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
3152 validateAnnotationType(pos, types.elemtype(type));
3153 return;
3154 }
3155 log.error(pos, Errors.InvalidAnnotationMemberType);
3156 }
3157
3158 /**
3159 * "It is also a compile-time error if any method declared in an
3160 * annotation type has a signature that is override-equivalent to
3161 * that of any public or protected method declared in class Object
3162 * or in the interface annotation.Annotation."
3163 *
3164 * @jls 9.6 Annotation Types
3165 */
3166 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
3167 for (Type sup = syms.annotationType; sup.hasTag(CLASS); sup = types.supertype(sup)) {
3168 Scope s = sup.tsym.members();
3169 for (Symbol sym : s.getSymbolsByName(m.name)) {
3170 if (sym.kind == MTH &&
3171 (sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
3172 types.overrideEquivalent(m.type, sym.type))
3173 log.error(pos, Errors.IntfAnnotationMemberClash(sym, sup));
3174 }
3175 }
3176 }
3177
3178 /** Check the annotations of a symbol.
3179 */
3180 public void validateAnnotations(List<JCAnnotation> annotations, JCTree declarationTree, Symbol s) {
3181 for (JCAnnotation a : annotations)
3182 validateAnnotation(a, declarationTree, s);
3183 }
3184
3185 /** Check the type annotations.
3186 */
3187 public void validateTypeAnnotations(List<JCAnnotation> annotations, boolean isTypeParameter) {
3188 for (JCAnnotation a : annotations)
3189 validateTypeAnnotation(a, isTypeParameter);
3190 }
3191
3192 /** Check an annotation of a symbol.
3193 */
3194 private void validateAnnotation(JCAnnotation a, JCTree declarationTree, Symbol s) {
3195 validateAnnotationTree(a);
3196 boolean isRecordMember = ((s.flags_field & RECORD) != 0 || s.enclClass() != null && s.enclClass().isRecord());
3197
3198 boolean isRecordField = (s.flags_field & RECORD) != 0 &&
3199 declarationTree.hasTag(VARDEF) &&
3200 s.owner.kind == TYP;
3201
3202 if (isRecordField) {
3203 // first we need to check if the annotation is applicable to records
3204 Name[] targets = getTargetNames(a);
3205 boolean appliesToRecords = false;
3206 for (Name target : targets) {
3207 appliesToRecords =
3208 target == names.FIELD ||
3209 target == names.PARAMETER ||
3210 target == names.METHOD ||
3211 target == names.TYPE_USE ||
3212 target == names.RECORD_COMPONENT;
3213 if (appliesToRecords) {
3214 break;
3215 }
3216 }
3217 if (!appliesToRecords) {
3218 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3219 } else {
3220 /* lets now find the annotations in the field that are targeted to record components and append them to
3221 * the corresponding record component
3222 */
3223 ClassSymbol recordClass = (ClassSymbol) s.owner;
3224 RecordComponent rc = recordClass.getRecordComponent((VarSymbol)s);
3225 SymbolMetadata metadata = rc.getMetadata();
3226 if (metadata == null || metadata.isEmpty()) {
3227 /* if not is empty then we have already been here, which is the case if multiple annotations are applied
3228 * to the record component declaration
3229 */
3230 rc.appendAttributes(s.getRawAttributes().stream().filter(anno ->
3231 Arrays.stream(getTargetNames(anno.type.tsym)).anyMatch(name -> name == names.RECORD_COMPONENT)
3232 ).collect(List.collector()));
3233 rc.setTypeAttributes(s.getRawTypeAttributes());
3234 // to get all the type annotations applied to the type
3235 rc.type = s.type;
3236 }
3237 }
3238 }
3239
3240 /* the section below is tricky. Annotations applied to record components are propagated to the corresponding
3241 * record member so if an annotation has target: FIELD, it is propagated to the corresponding FIELD, if it has
3242 * target METHOD, it is propagated to the accessor and so on. But at the moment when method members are generated
3243 * there is no enough information to propagate only the right annotations. So all the annotations are propagated
3244 * to all the possible locations.
3245 *
3246 * At this point we need to remove all the annotations that are not in place before going on with the annotation
3247 * party. On top of the above there is the issue that there is no AST representing record components, just symbols
3248 * so the corresponding field has been holding all the annotations and it's metadata has been modified as if it
3249 * was both a field and a record component.
3250 *
3251 * So there are two places where we need to trim annotations from: the metadata of the symbol and / or the modifiers
3252 * in the AST. Whatever is in the metadata will be written to the class file, whatever is in the modifiers could
3253 * be see by annotation processors.
3254 *
3255 * The metadata contains both type annotations and declaration annotations. At this point of the game we don't
3256 * need to care about type annotations, they are all in the right place. But we could need to remove declaration
3257 * annotations. So for declaration annotations if they are not applicable to the record member, excluding type
3258 * annotations which are already correct, then we will remove it. For the AST modifiers if the annotation is not
3259 * applicable either as type annotation and or declaration annotation, only in that case it will be removed.
3260 *
3261 * So it could be that annotation is removed as a declaration annotation but it is kept in the AST modifier for
3262 * further inspection by annotation processors.
3263 *
3264 * For example:
3265 *
3266 * import java.lang.annotation.*;
3267 *
3268 * @Target({ElementType.TYPE_USE, ElementType.RECORD_COMPONENT})
3269 * @Retention(RetentionPolicy.RUNTIME)
3270 * @interface Anno { }
3271 *
3272 * record R(@Anno String s) {}
3273 *
3274 * at this point we will have for the case of the generated field:
3275 * - @Anno in the modifier
3276 * - @Anno as a type annotation
3277 * - @Anno as a declaration annotation
3278 *
3279 * the last one should be removed because the annotation has not FIELD as target but it was applied as a
3280 * declaration annotation because the field was being treated both as a field and as a record component
3281 * as we have already copied the annotations to the record component, now the field doesn't need to hold
3282 * annotations that are not intended for it anymore. Still @Anno has to be kept in the AST's modifiers as it
3283 * is applicable as a type annotation to the type of the field.
3284 */
3285
3286 if (a.type.tsym.isAnnotationType()) {
3287 Optional<Set<Name>> applicableTargetsOp = getApplicableTargets(a, s);
3288 if (!applicableTargetsOp.isEmpty()) {
3289 Set<Name> applicableTargets = applicableTargetsOp.get();
3290 boolean notApplicableOrIsTypeUseOnly = applicableTargets.isEmpty() ||
3291 applicableTargets.size() == 1 && applicableTargets.contains(names.TYPE_USE);
3292 boolean isCompGeneratedRecordElement = isRecordMember && (s.flags_field & Flags.GENERATED_MEMBER) != 0;
3293 boolean isCompRecordElementWithNonApplicableDeclAnno = isCompGeneratedRecordElement && notApplicableOrIsTypeUseOnly;
3294
3295 if (applicableTargets.isEmpty() || isCompRecordElementWithNonApplicableDeclAnno) {
3296 if (isCompRecordElementWithNonApplicableDeclAnno) {
3297 /* so we have found an annotation that is not applicable to a record member that was generated by the
3298 * compiler. This was intentionally done at TypeEnter, now is the moment strip away the annotations
3299 * that are not applicable to the given record member
3300 */
3301 JCModifiers modifiers = TreeInfo.getModifiers(declarationTree);
3302 /* lets first remove the annotation from the modifier if it is not applicable, we have to check again as
3303 * it could be a type annotation
3304 */
3305 if (modifiers != null && applicableTargets.isEmpty()) {
3306 ListBuffer<JCAnnotation> newAnnotations = new ListBuffer<>();
3307 for (JCAnnotation anno : modifiers.annotations) {
3308 if (anno != a) {
3309 newAnnotations.add(anno);
3310 }
3311 }
3312 modifiers.annotations = newAnnotations.toList();
3313 }
3314 // now lets remove it from the symbol
3315 s.getMetadata().removeDeclarationMetadata(a.attribute);
3316 } else {
3317 log.error(a.pos(), Errors.AnnotationTypeNotApplicable);
3318 }
3319 }
3320 /* if we are seeing the @SafeVarargs annotation applied to a compiler generated accessor,
3321 * then this is an error as we know that no compiler generated accessor will be a varargs
3322 * method, better to fail asap
3323 */
3324 if (isCompGeneratedRecordElement && !isRecordField && a.type.tsym == syms.trustMeType.tsym && declarationTree.hasTag(METHODDEF)) {
3325 log.error(a.pos(), Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym, Fragments.VarargsTrustmeOnNonVarargsAccessor(s)));
3326 }
3327 }
3328 }
3329
3330 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
3331 if (s.kind != TYP) {
3332 log.error(a.pos(), Errors.BadFunctionalIntfAnno);
3333 } else if (!s.isInterface() || (s.flags() & ANNOTATION) != 0) {
3334 log.error(a.pos(), Errors.BadFunctionalIntfAnno1(Fragments.NotAFunctionalIntf(s)));
3335 }
3336 }
3337 }
3338
3339 public void validateTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
3340 Assert.checkNonNull(a.type);
3341 validateAnnotationTree(a);
3342
3343 if (a.hasTag(TYPE_ANNOTATION) &&
3344 !a.annotationType.type.isErroneous() &&
3345 !isTypeAnnotation(a, isTypeParameter)) {
3346 log.error(a.pos(), Errors.AnnotationTypeNotApplicableToType(a.type));
3347 }
3348 }
3349
3350 /**
3351 * Validate the proposed container 'repeatable' on the
3352 * annotation type symbol 's'. Report errors at position
3353 * 'pos'.
3354 *
3355 * @param s The (annotation)type declaration annotated with a @Repeatable
3356 * @param repeatable the @Repeatable on 's'
3357 * @param pos where to report errors
3358 */
3359 public void validateRepeatable(TypeSymbol s, Attribute.Compound repeatable, DiagnosticPosition pos) {
3360 Assert.check(types.isSameType(repeatable.type, syms.repeatableType));
3361
3362 Type t = null;
3363 List<Pair<MethodSymbol,Attribute>> l = repeatable.values;
3364 if (!l.isEmpty()) {
3365 Assert.check(l.head.fst.name == names.value);
3366 if (l.head.snd instanceof Attribute.Class) {
3367 t = ((Attribute.Class)l.head.snd).getValue();
3368 }
3369 }
3370
3371 if (t == null) {
3372 // errors should already have been reported during Annotate
3373 return;
3374 }
3375
3376 validateValue(t.tsym, s, pos);
3377 validateRetention(t.tsym, s, pos);
3378 validateDocumented(t.tsym, s, pos);
3379 validateInherited(t.tsym, s, pos);
3380 validateTarget(t.tsym, s, pos);
3381 validateDefault(t.tsym, pos);
3382 }
3383
3384 private void validateValue(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3385 Symbol sym = container.members().findFirst(names.value);
3386 if (sym != null && sym.kind == MTH) {
3387 MethodSymbol m = (MethodSymbol) sym;
3388 Type ret = m.getReturnType();
3389 if (!(ret.hasTag(ARRAY) && types.isSameType(((ArrayType)ret).elemtype, contained.type))) {
3390 log.error(pos,
3391 Errors.InvalidRepeatableAnnotationValueReturn(container,
3392 ret,
3393 types.makeArrayType(contained.type)));
3394 }
3395 } else {
3396 log.error(pos, Errors.InvalidRepeatableAnnotationNoValue(container));
3397 }
3398 }
3399
3400 private void validateRetention(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3401 Attribute.RetentionPolicy containerRetention = types.getRetention(container);
3402 Attribute.RetentionPolicy containedRetention = types.getRetention(contained);
3403
3404 boolean error = false;
3405 switch (containedRetention) {
3406 case RUNTIME:
3407 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) {
3408 error = true;
3409 }
3410 break;
3411 case CLASS:
3412 if (containerRetention == Attribute.RetentionPolicy.SOURCE) {
3413 error = true;
3414 }
3415 }
3416 if (error ) {
3417 log.error(pos,
3418 Errors.InvalidRepeatableAnnotationRetention(container,
3419 containerRetention.name(),
3420 contained,
3421 containedRetention.name()));
3422 }
3423 }
3424
3425 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) {
3426 if (contained.attribute(syms.documentedType.tsym) != null) {
3427 if (container.attribute(syms.documentedType.tsym) == null) {
3428 log.error(pos, Errors.InvalidRepeatableAnnotationNotDocumented(container, contained));
3429 }
3430 }
3431 }
3432
3433 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) {
3434 if (contained.attribute(syms.inheritedType.tsym) != null) {
3435 if (container.attribute(syms.inheritedType.tsym) == null) {
3436 log.error(pos, Errors.InvalidRepeatableAnnotationNotInherited(container, contained));
3437 }
3438 }
3439 }
3440
3441 private void validateTarget(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
3442 // The set of targets the container is applicable to must be a subset
3443 // (with respect to annotation target semantics) of the set of targets
3444 // the contained is applicable to. The target sets may be implicit or
3445 // explicit.
3446
3447 Set<Name> containerTargets;
3448 Attribute.Array containerTarget = getAttributeTargetAttribute(container);
3449 if (containerTarget == null) {
3450 containerTargets = getDefaultTargetSet();
3451 } else {
3452 containerTargets = new HashSet<>();
3453 for (Attribute app : containerTarget.values) {
3454 if (!(app instanceof Attribute.Enum attributeEnum)) {
3455 continue; // recovery
3456 }
3457 containerTargets.add(attributeEnum.value.name);
3458 }
3459 }
3460
3461 Set<Name> containedTargets;
3462 Attribute.Array containedTarget = getAttributeTargetAttribute(contained);
3463 if (containedTarget == null) {
3464 containedTargets = getDefaultTargetSet();
3465 } else {
3466 containedTargets = new HashSet<>();
3467 for (Attribute app : containedTarget.values) {
3468 if (!(app instanceof Attribute.Enum attributeEnum)) {
3469 continue; // recovery
3470 }
3471 containedTargets.add(attributeEnum.value.name);
3472 }
3473 }
3474
3475 if (!isTargetSubsetOf(containerTargets, containedTargets)) {
3476 log.error(pos, Errors.InvalidRepeatableAnnotationIncompatibleTarget(container, contained));
3477 }
3478 }
3479
3480 /* get a set of names for the default target */
3481 private Set<Name> getDefaultTargetSet() {
3482 if (defaultTargets == null) {
3483 defaultTargets = Set.of(defaultTargetMetaInfo());
3484 }
3485
3486 return defaultTargets;
3487 }
3488 private Set<Name> defaultTargets;
3489
3490
3491 /** Checks that s is a subset of t, with respect to ElementType
3492 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE},
3493 * and {TYPE_USE} covers the set {ANNOTATION_TYPE, TYPE, TYPE_USE,
3494 * TYPE_PARAMETER}.
3495 */
3496 private boolean isTargetSubsetOf(Set<Name> s, Set<Name> t) {
3497 // Check that all elements in s are present in t
3498 for (Name n2 : s) {
3499 boolean currentElementOk = false;
3500 for (Name n1 : t) {
3501 if (n1 == n2) {
3502 currentElementOk = true;
3503 break;
3504 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) {
3505 currentElementOk = true;
3506 break;
3507 } else if (n1 == names.TYPE_USE &&
3508 (n2 == names.TYPE ||
3509 n2 == names.ANNOTATION_TYPE ||
3510 n2 == names.TYPE_PARAMETER)) {
3511 currentElementOk = true;
3512 break;
3513 }
3514 }
3515 if (!currentElementOk)
3516 return false;
3517 }
3518 return true;
3519 }
3520
3521 private void validateDefault(Symbol container, DiagnosticPosition pos) {
3522 // validate that all other elements of containing type has defaults
3523 Scope scope = container.members();
3524 for(Symbol elm : scope.getSymbols()) {
3525 if (elm.name != names.value &&
3526 elm.kind == MTH &&
3527 ((MethodSymbol)elm).defaultValue == null) {
3528 log.error(pos,
3529 Errors.InvalidRepeatableAnnotationElemNondefault(container, elm));
3530 }
3531 }
3532 }
3533
3534 /** Is s a method symbol that overrides a method in a superclass? */
3535 boolean isOverrider(Symbol s) {
3536 if (s.kind != MTH || s.isStatic())
3537 return false;
3538 MethodSymbol m = (MethodSymbol)s;
3539 TypeSymbol owner = (TypeSymbol)m.owner;
3540 for (Type sup : types.closure(owner.type)) {
3541 if (sup == owner.type)
3542 continue; // skip "this"
3543 Scope scope = sup.tsym.members();
3544 for (Symbol sym : scope.getSymbolsByName(m.name)) {
3545 if (!sym.isStatic() && m.overrides(sym, owner, types, true))
3546 return true;
3547 }
3548 }
3549 return false;
3550 }
3551
3552 /** Is the annotation applicable to types? */
3553 protected boolean isTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
3554 List<Attribute> targets = typeAnnotations.annotationTargets(a.annotationType.type.tsym);
3555 return (targets == null) ?
3556 false :
3557 targets.stream()
3558 .anyMatch(attr -> isTypeAnnotation(attr, isTypeParameter));
3559 }
3560 //where
3561 boolean isTypeAnnotation(Attribute a, boolean isTypeParameter) {
3562 Attribute.Enum e = (Attribute.Enum)a;
3563 return (e.value.name == names.TYPE_USE ||
3564 (isTypeParameter && e.value.name == names.TYPE_PARAMETER));
3565 }
3566
3567 /** Is the annotation applicable to the symbol? */
3568 Name[] getTargetNames(JCAnnotation a) {
3569 return getTargetNames(a.annotationType.type.tsym);
3570 }
3571
3572 public Name[] getTargetNames(TypeSymbol annoSym) {
3573 Attribute.Array arr = getAttributeTargetAttribute(annoSym);
3574 Name[] targets;
3575 if (arr == null) {
3576 targets = defaultTargetMetaInfo();
3577 } else {
3578 // TODO: can we optimize this?
3579 targets = new Name[arr.values.length];
3580 for (int i=0; i<arr.values.length; ++i) {
3581 Attribute app = arr.values[i];
3582 if (!(app instanceof Attribute.Enum attributeEnum)) {
3583 return new Name[0];
3584 }
3585 targets[i] = attributeEnum.value.name;
3586 }
3587 }
3588 return targets;
3589 }
3590
3591 boolean annotationApplicable(JCAnnotation a, Symbol s) {
3592 Optional<Set<Name>> targets = getApplicableTargets(a, s);
3593 /* the optional could be emtpy if the annotation is unknown in that case
3594 * we return that it is applicable and if it is erroneous that should imply
3595 * an error at the declaration site
3596 */
3597 return targets.isEmpty() || targets.isPresent() && !targets.get().isEmpty();
3598 }
3599
3600 Optional<Set<Name>> getApplicableTargets(JCAnnotation a, Symbol s) {
3601 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym);
3602 Name[] targets;
3603 Set<Name> applicableTargets = new HashSet<>();
3604
3605 if (arr == null) {
3606 targets = defaultTargetMetaInfo();
3607 } else {
3608 // TODO: can we optimize this?
3609 targets = new Name[arr.values.length];
3610 for (int i=0; i<arr.values.length; ++i) {
3611 Attribute app = arr.values[i];
3612 if (!(app instanceof Attribute.Enum attributeEnum)) {
3613 // recovery
3614 return Optional.empty();
3615 }
3616 targets[i] = attributeEnum.value.name;
3617 }
3618 }
3619 for (Name target : targets) {
3620 if (target == names.TYPE) {
3621 if (s.kind == TYP)
3622 applicableTargets.add(names.TYPE);
3623 } else if (target == names.FIELD) {
3624 if (s.kind == VAR && s.owner.kind != MTH)
3625 applicableTargets.add(names.FIELD);
3626 } else if (target == names.RECORD_COMPONENT) {
3627 if (s.getKind() == ElementKind.RECORD_COMPONENT) {
3628 applicableTargets.add(names.RECORD_COMPONENT);
3629 }
3630 } else if (target == names.METHOD) {
3631 if (s.kind == MTH && !s.isConstructor())
3632 applicableTargets.add(names.METHOD);
3633 } else if (target == names.PARAMETER) {
3634 if (s.kind == VAR &&
3635 (s.owner.kind == MTH && (s.flags() & PARAMETER) != 0)) {
3636 applicableTargets.add(names.PARAMETER);
3637 }
3638 } else if (target == names.CONSTRUCTOR) {
3639 if (s.kind == MTH && s.isConstructor())
3640 applicableTargets.add(names.CONSTRUCTOR);
3641 } else if (target == names.LOCAL_VARIABLE) {
3642 if (s.kind == VAR && s.owner.kind == MTH &&
3643 (s.flags() & PARAMETER) == 0) {
3644 applicableTargets.add(names.LOCAL_VARIABLE);
3645 }
3646 } else if (target == names.ANNOTATION_TYPE) {
3647 if (s.kind == TYP && (s.flags() & ANNOTATION) != 0) {
3648 applicableTargets.add(names.ANNOTATION_TYPE);
3649 }
3650 } else if (target == names.PACKAGE) {
3651 if (s.kind == PCK)
3652 applicableTargets.add(names.PACKAGE);
3653 } else if (target == names.TYPE_USE) {
3654 if (s.kind == VAR && s.owner.kind == MTH && s.type.hasTag(NONE)) {
3655 //cannot type annotate implicitly typed locals
3656 continue;
3657 } else if (s.kind == TYP || s.kind == VAR ||
3658 (s.kind == MTH && !s.isConstructor() &&
3659 !s.type.getReturnType().hasTag(VOID)) ||
3660 (s.kind == MTH && s.isConstructor())) {
3661 applicableTargets.add(names.TYPE_USE);
3662 }
3663 } else if (target == names.TYPE_PARAMETER) {
3664 if (s.kind == TYP && s.type.hasTag(TYPEVAR))
3665 applicableTargets.add(names.TYPE_PARAMETER);
3666 } else if (target == names.MODULE) {
3667 if (s.kind == MDL)
3668 applicableTargets.add(names.MODULE);
3669 } else
3670 return Optional.empty(); // Unknown ElementType. This should be an error at declaration site,
3671 // assume applicable.
3672 }
3673 return Optional.of(applicableTargets);
3674 }
3675
3676 Attribute.Array getAttributeTargetAttribute(TypeSymbol s) {
3677 Attribute.Compound atTarget = s.getAnnotationTypeMetadata().getTarget();
3678 if (atTarget == null) return null; // ok, is applicable
3679 Attribute atValue = atTarget.member(names.value);
3680 return (atValue instanceof Attribute.Array attributeArray) ? attributeArray : null;
3681 }
3682
3683 private Name[] dfltTargetMeta;
3684 private Name[] defaultTargetMetaInfo() {
3685 if (dfltTargetMeta == null) {
3686 ArrayList<Name> defaultTargets = new ArrayList<>();
3687 defaultTargets.add(names.PACKAGE);
3688 defaultTargets.add(names.TYPE);
3689 defaultTargets.add(names.FIELD);
3690 defaultTargets.add(names.METHOD);
3691 defaultTargets.add(names.CONSTRUCTOR);
3692 defaultTargets.add(names.ANNOTATION_TYPE);
3693 defaultTargets.add(names.LOCAL_VARIABLE);
3694 defaultTargets.add(names.PARAMETER);
3695 if (allowRecords) {
3696 defaultTargets.add(names.RECORD_COMPONENT);
3697 }
3698 if (allowModules) {
3699 defaultTargets.add(names.MODULE);
3700 }
3701 dfltTargetMeta = defaultTargets.toArray(new Name[0]);
3702 }
3703 return dfltTargetMeta;
3704 }
3705
3706 /** Check an annotation value.
3707 *
3708 * @param a The annotation tree to check
3709 * @return true if this annotation tree is valid, otherwise false
3710 */
3711 public boolean validateAnnotationDeferErrors(JCAnnotation a) {
3712 boolean res = false;
3713 final Log.DiagnosticHandler diagHandler = new Log.DiscardDiagnosticHandler(log);
3714 try {
3715 res = validateAnnotation(a);
3716 } finally {
3717 log.popDiagnosticHandler(diagHandler);
3718 }
3719 return res;
3720 }
3721
3722 private boolean validateAnnotation(JCAnnotation a) {
3723 boolean isValid = true;
3724 AnnotationTypeMetadata metadata = a.annotationType.type.tsym.getAnnotationTypeMetadata();
3725
3726 // collect an inventory of the annotation elements
3727 Set<MethodSymbol> elements = metadata.getAnnotationElements();
3728
3729 // remove the ones that are assigned values
3730 for (JCTree arg : a.args) {
3731 if (!arg.hasTag(ASSIGN)) continue; // recovery
3732 JCAssign assign = (JCAssign)arg;
3733 Symbol m = TreeInfo.symbol(assign.lhs);
3734 if (m == null || m.type.isErroneous()) continue;
3735 if (!elements.remove(m)) {
3736 isValid = false;
3737 log.error(assign.lhs.pos(),
3738 Errors.DuplicateAnnotationMemberValue(m.name, a.type));
3739 }
3740 }
3741
3742 // all the remaining ones better have default values
3743 List<Name> missingDefaults = List.nil();
3744 Set<MethodSymbol> membersWithDefault = metadata.getAnnotationElementsWithDefault();
3745 for (MethodSymbol m : elements) {
3746 if (m.type.isErroneous())
3747 continue;
3748
3749 if (!membersWithDefault.contains(m))
3750 missingDefaults = missingDefaults.append(m.name);
3751 }
3752 missingDefaults = missingDefaults.reverse();
3753 if (missingDefaults.nonEmpty()) {
3754 isValid = false;
3755 Error errorKey = (missingDefaults.size() > 1)
3756 ? Errors.AnnotationMissingDefaultValue1(a.type, missingDefaults)
3757 : Errors.AnnotationMissingDefaultValue(a.type, missingDefaults);
3758 log.error(a.pos(), errorKey);
3759 }
3760
3761 return isValid && validateTargetAnnotationValue(a);
3762 }
3763
3764 /* Validate the special java.lang.annotation.Target annotation */
3765 boolean validateTargetAnnotationValue(JCAnnotation a) {
3766 // special case: java.lang.annotation.Target must not have
3767 // repeated values in its value member
3768 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
3769 a.args.tail == null)
3770 return true;
3771
3772 boolean isValid = true;
3773 if (!a.args.head.hasTag(ASSIGN)) return false; // error recovery
3774 JCAssign assign = (JCAssign) a.args.head;
3775 Symbol m = TreeInfo.symbol(assign.lhs);
3776 if (m.name != names.value) return false;
3777 JCTree rhs = assign.rhs;
3778 if (!rhs.hasTag(NEWARRAY)) return false;
3779 JCNewArray na = (JCNewArray) rhs;
3780 Set<Symbol> targets = new HashSet<>();
3781 for (JCTree elem : na.elems) {
3782 if (!targets.add(TreeInfo.symbol(elem))) {
3783 isValid = false;
3784 log.error(elem.pos(), Errors.RepeatedAnnotationTarget);
3785 }
3786 }
3787 return isValid;
3788 }
3789
3790 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
3791 if (lint.isEnabled(LintCategory.DEP_ANN) && s.isDeprecatableViaAnnotation() &&
3792 (s.flags() & DEPRECATED) != 0 &&
3793 !syms.deprecatedType.isErroneous() &&
3794 s.attribute(syms.deprecatedType.tsym) == null) {
3795 log.warning(LintCategory.DEP_ANN,
3796 pos, Warnings.MissingDeprecatedAnnotation);
3797 }
3798 // Note: @Deprecated has no effect on local variables, parameters and package decls.
3799 if (lint.isEnabled(LintCategory.DEPRECATION) && !s.isDeprecatableViaAnnotation()) {
3800 if (!syms.deprecatedType.isErroneous() && s.attribute(syms.deprecatedType.tsym) != null) {
3801 log.warning(LintCategory.DEPRECATION, pos,
3802 Warnings.DeprecatedAnnotationHasNoEffect(Kinds.kindName(s)));
3803 }
3804 }
3805 }
3806
3807 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
3808 checkDeprecated(() -> pos, other, s);
3809 }
3810
3811 void checkDeprecated(Supplier<DiagnosticPosition> pos, final Symbol other, final Symbol s) {
3812 if ( (s.isDeprecatedForRemoval()
3813 || s.isDeprecated() && !other.isDeprecated())
3814 && (s.outermostClass() != other.outermostClass() || s.outermostClass() == null)
3815 && s.kind != Kind.PCK) {
3816 deferredLintHandler.report(() -> warnDeprecated(pos.get(), s));
3817 }
3818 }
3819
3820 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
3821 if ((s.flags() & PROPRIETARY) != 0) {
3822 deferredLintHandler.report(() -> {
3823 log.mandatoryWarning(pos, Warnings.SunProprietary(s));
3824 });
3825 }
3826 }
3827
3828 void checkProfile(final DiagnosticPosition pos, final Symbol s) {
3829 if (profile != Profile.DEFAULT && (s.flags() & NOT_IN_PROFILE) != 0) {
3830 log.error(pos, Errors.NotInProfile(s, profile));
3831 }
3832 }
3833
3834 void checkPreview(DiagnosticPosition pos, Symbol other, Symbol s) {
3835 if ((s.flags() & PREVIEW_API) != 0 && s.packge().modle != other.packge().modle) {
3836 if ((s.flags() & PREVIEW_REFLECTIVE) == 0) {
3837 if (!preview.isEnabled()) {
3838 log.error(pos, Errors.IsPreview(s));
3839 } else {
3840 preview.markUsesPreview(pos);
3841 deferredLintHandler.report(() -> warnPreviewAPI(pos, Warnings.IsPreview(s)));
3842 }
3843 } else {
3844 deferredLintHandler.report(() -> warnPreviewAPI(pos, Warnings.IsPreviewReflective(s)));
3845 }
3846 }
3847 if (preview.declaredUsingPreviewFeature(s)) {
3848 if (preview.isEnabled()) {
3849 //for preview disabled do presumably so not need to do anything?
3850 //If "s" is compiled from source, then there was an error for it already;
3851 //if "s" is from classfile, there already was an error for the classfile.
3852 preview.markUsesPreview(pos);
3853 deferredLintHandler.report(() -> warnDeclaredUsingPreview(pos, s));
3854 }
3855 }
3856 }
3857
3858 /* *************************************************************************
3859 * Check for recursive annotation elements.
3860 **************************************************************************/
3861
3862 /** Check for cycles in the graph of annotation elements.
3863 */
3864 void checkNonCyclicElements(JCClassDecl tree) {
3865 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
3866 Assert.check((tree.sym.flags_field & LOCKED) == 0);
3867 try {
3868 tree.sym.flags_field |= LOCKED;
3869 for (JCTree def : tree.defs) {
3870 if (!def.hasTag(METHODDEF)) continue;
3871 JCMethodDecl meth = (JCMethodDecl)def;
3872 checkAnnotationResType(meth.pos(), meth.restype.type);
3873 }
3874 } finally {
3875 tree.sym.flags_field &= ~LOCKED;
3876 tree.sym.flags_field |= ACYCLIC_ANN;
3877 }
3878 }
3879
3880 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
3881 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
3882 return;
3883 if ((tsym.flags_field & LOCKED) != 0) {
3884 log.error(pos, Errors.CyclicAnnotationElement(tsym));
3885 return;
3886 }
3887 try {
3888 tsym.flags_field |= LOCKED;
3889 for (Symbol s : tsym.members().getSymbols(NON_RECURSIVE)) {
3890 if (s.kind != MTH)
3891 continue;
3892 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
3893 }
3894 } finally {
3895 tsym.flags_field &= ~LOCKED;
3896 tsym.flags_field |= ACYCLIC_ANN;
3897 }
3898 }
3899
3900 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
3901 switch (type.getTag()) {
3902 case CLASS:
3903 if ((type.tsym.flags() & ANNOTATION) != 0)
3904 checkNonCyclicElementsInternal(pos, type.tsym);
3905 break;
3906 case ARRAY:
3907 checkAnnotationResType(pos, types.elemtype(type));
3908 break;
3909 default:
3910 break; // int etc
3911 }
3912 }
3913
3914 /* *************************************************************************
3915 * Check for cycles in the constructor call graph.
3916 **************************************************************************/
3917
3918 /** Check for cycles in the graph of constructors calling other
3919 * constructors.
3920 */
3921 void checkCyclicConstructors(JCClassDecl tree) {
3922 Map<Symbol,Symbol> callMap = new HashMap<>();
3923
3924 // enter each constructor this-call into the map
3925 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3926 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
3927 if (app == null) continue;
3928 JCMethodDecl meth = (JCMethodDecl) l.head;
3929 if (TreeInfo.name(app.meth) == names._this) {
3930 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
3931 } else {
3932 meth.sym.flags_field |= ACYCLIC;
3933 }
3934 }
3935
3936 // Check for cycles in the map
3937 Symbol[] ctors = new Symbol[0];
3938 ctors = callMap.keySet().toArray(ctors);
3939 for (Symbol caller : ctors) {
3940 checkCyclicConstructor(tree, caller, callMap);
3941 }
3942 }
3943
3944 /** Look in the map to see if the given constructor is part of a
3945 * call cycle.
3946 */
3947 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
3948 Map<Symbol,Symbol> callMap) {
3949 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
3950 if ((ctor.flags_field & LOCKED) != 0) {
3951 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
3952 Errors.RecursiveCtorInvocation);
3953 } else {
3954 ctor.flags_field |= LOCKED;
3955 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
3956 ctor.flags_field &= ~LOCKED;
3957 }
3958 ctor.flags_field |= ACYCLIC;
3959 }
3960 }
3961
3962 /* *************************************************************************
3963 * Miscellaneous
3964 **************************************************************************/
3965
3966 /**
3967 * Check for division by integer constant zero
3968 * @param pos Position for error reporting.
3969 * @param operator The operator for the expression
3970 * @param operand The right hand operand for the expression
3971 */
3972 void checkDivZero(final DiagnosticPosition pos, Symbol operator, Type operand) {
3973 if (operand.constValue() != null
3974 && operand.getTag().isSubRangeOf(LONG)
3975 && ((Number) (operand.constValue())).longValue() == 0) {
3976 int opc = ((OperatorSymbol)operator).opcode;
3977 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
3978 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
3979 deferredLintHandler.report(() -> warnDivZero(pos));
3980 }
3981 }
3982 }
3983
3984 /**
3985 * Check for empty statements after if
3986 */
3987 void checkEmptyIf(JCIf tree) {
3988 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null &&
3989 lint.isEnabled(LintCategory.EMPTY))
3990 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), Warnings.EmptyIf);
3991 }
3992
3993 /** Check that symbol is unique in given scope.
3994 * @param pos Position for error reporting.
3995 * @param sym The symbol.
3996 * @param s The scope.
3997 */
3998 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
3999 if (sym.type.isErroneous())
4000 return true;
4001 if (sym.owner.name == names.any) return false;
4002 for (Symbol byName : s.getSymbolsByName(sym.name, NON_RECURSIVE)) {
4003 if (sym != byName &&
4004 (byName.flags() & CLASH) == 0 &&
4005 sym.kind == byName.kind &&
4006 sym.name != names.error &&
4007 (sym.kind != MTH ||
4008 types.hasSameArgs(sym.type, byName.type) ||
4009 types.hasSameArgs(types.erasure(sym.type), types.erasure(byName.type)))) {
4010 if ((sym.flags() & VARARGS) != (byName.flags() & VARARGS)) {
4011 sym.flags_field |= CLASH;
4012 varargsDuplicateError(pos, sym, byName);
4013 return true;
4014 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, byName.type, false)) {
4015 duplicateErasureError(pos, sym, byName);
4016 sym.flags_field |= CLASH;
4017 return true;
4018 } else if ((sym.flags() & MATCH_BINDING) != 0 &&
4019 (byName.flags() & MATCH_BINDING) != 0 &&
4020 (byName.flags() & MATCH_BINDING_TO_OUTER) == 0) {
4021 if (!sym.type.isErroneous()) {
4022 log.error(pos, Errors.MatchBindingExists);
4023 sym.flags_field |= CLASH;
4024 }
4025 return false;
4026 } else {
4027 duplicateError(pos, byName);
4028 return false;
4029 }
4030 }
4031 }
4032 return true;
4033 }
4034
4035 /** Report duplicate declaration error.
4036 */
4037 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
4038 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
4039 log.error(pos, Errors.NameClashSameErasure(sym1, sym2));
4040 }
4041 }
4042
4043 /**Check that types imported through the ordinary imports don't clash with types imported
4044 * by other (static or ordinary) imports. Note that two static imports may import two clashing
4045 * types without an error on the imports.
4046 * @param toplevel The toplevel tree for which the test should be performed.
4047 */
4048 void checkImportsUnique(JCCompilationUnit toplevel) {
4049 WriteableScope ordinallyImportedSoFar = WriteableScope.create(toplevel.packge);
4050 WriteableScope staticallyImportedSoFar = WriteableScope.create(toplevel.packge);
4051 WriteableScope topLevelScope = toplevel.toplevelScope;
4052
4053 for (JCTree def : toplevel.defs) {
4054 if (!def.hasTag(IMPORT))
4055 continue;
4056
4057 JCImport imp = (JCImport) def;
4058
4059 if (imp.importScope == null)
4060 continue;
4061
4062 for (Symbol sym : imp.importScope.getSymbols(sym -> sym.kind == TYP)) {
4063 if (imp.isStatic()) {
4064 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, true);
4065 staticallyImportedSoFar.enter(sym);
4066 } else {
4067 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, false);
4068 ordinallyImportedSoFar.enter(sym);
4069 }
4070 }
4071
4072 imp.importScope = null;
4073 }
4074 }
4075
4076 /** Check that single-type import is not already imported or top-level defined,
4077 * but make an exception for two single-type imports which denote the same type.
4078 * @param pos Position for error reporting.
4079 * @param ordinallyImportedSoFar A Scope containing types imported so far through
4080 * ordinary imports.
4081 * @param staticallyImportedSoFar A Scope containing types imported so far through
4082 * static imports.
4083 * @param topLevelScope The current file's top-level Scope
4084 * @param sym The symbol.
4085 * @param staticImport Whether or not this was a static import
4086 */
4087 private boolean checkUniqueImport(DiagnosticPosition pos, Scope ordinallyImportedSoFar,
4088 Scope staticallyImportedSoFar, Scope topLevelScope,
4089 Symbol sym, boolean staticImport) {
4090 Predicate<Symbol> duplicates = candidate -> candidate != sym && !candidate.type.isErroneous();
4091 Symbol ordinaryClashing = ordinallyImportedSoFar.findFirst(sym.name, duplicates);
4092 Symbol staticClashing = null;
4093 if (ordinaryClashing == null && !staticImport) {
4094 staticClashing = staticallyImportedSoFar.findFirst(sym.name, duplicates);
4095 }
4096 if (ordinaryClashing != null || staticClashing != null) {
4097 if (ordinaryClashing != null)
4098 log.error(pos, Errors.AlreadyDefinedSingleImport(ordinaryClashing));
4099 else
4100 log.error(pos, Errors.AlreadyDefinedStaticSingleImport(staticClashing));
4101 return false;
4102 }
4103 Symbol clashing = topLevelScope.findFirst(sym.name, duplicates);
4104 if (clashing != null) {
4105 log.error(pos, Errors.AlreadyDefinedThisUnit(clashing));
4106 return false;
4107 }
4108 return true;
4109 }
4110
4111 /** Check that a qualified name is in canonical form (for import decls).
4112 */
4113 public void checkCanonical(JCTree tree) {
4114 if (!isCanonical(tree))
4115 log.error(tree.pos(),
4116 Errors.ImportRequiresCanonical(TreeInfo.symbol(tree)));
4117 }
4118 // where
4119 private boolean isCanonical(JCTree tree) {
4120 while (tree.hasTag(SELECT)) {
4121 JCFieldAccess s = (JCFieldAccess) tree;
4122 if (s.sym.owner.getQualifiedName() != TreeInfo.symbol(s.selected).getQualifiedName())
4123 return false;
4124 tree = s.selected;
4125 }
4126 return true;
4127 }
4128
4129 /** Check that an auxiliary class is not accessed from any other file than its own.
4130 */
4131 void checkForBadAuxiliaryClassAccess(DiagnosticPosition pos, Env<AttrContext> env, ClassSymbol c) {
4132 if (lint.isEnabled(Lint.LintCategory.AUXILIARYCLASS) &&
4133 (c.flags() & AUXILIARY) != 0 &&
4134 rs.isAccessible(env, c) &&
4135 !fileManager.isSameFile(c.sourcefile, env.toplevel.sourcefile))
4136 {
4137 log.warning(pos,
4138 Warnings.AuxiliaryClassAccessedFromOutsideOfItsSourceFile(c, c.sourcefile));
4139 }
4140 }
4141
4142 /**
4143 * Check for a default constructor in an exported package.
4144 */
4145 void checkDefaultConstructor(ClassSymbol c, DiagnosticPosition pos) {
4146 if (lint.isEnabled(LintCategory.MISSING_EXPLICIT_CTOR) &&
4147 ((c.flags() & (ENUM | RECORD)) == 0) &&
4148 !c.isAnonymous() &&
4149 ((c.flags() & (PUBLIC | PROTECTED)) != 0) &&
4150 Feature.MODULES.allowedInSource(source)) {
4151 NestingKind nestingKind = c.getNestingKind();
4152 switch (nestingKind) {
4153 case ANONYMOUS,
4154 LOCAL -> {return;}
4155 case TOP_LEVEL -> {;} // No additional checks needed
4156 case MEMBER -> {
4157 // For nested member classes, all the enclosing
4158 // classes must be public or protected.
4159 Symbol owner = c.owner;
4160 while (owner != null && owner.kind == TYP) {
4161 if ((owner.flags() & (PUBLIC | PROTECTED)) == 0)
4162 return;
4163 owner = owner.owner;
4164 }
4165 }
4166 }
4167
4168 // Only check classes in named packages exported by its module
4169 PackageSymbol pkg = c.packge();
4170 if (!pkg.isUnnamed()) {
4171 ModuleSymbol modle = pkg.modle;
4172 for (ExportsDirective exportDir : modle.exports) {
4173 // Report warning only if the containing
4174 // package is unconditionally exported
4175 if (exportDir.packge.equals(pkg)) {
4176 if (exportDir.modules == null || exportDir.modules.isEmpty()) {
4177 // Warning may be suppressed by
4178 // annotations; check again for being
4179 // enabled in the deferred context.
4180 deferredLintHandler.report(() -> {
4181 if (lint.isEnabled(LintCategory.MISSING_EXPLICIT_CTOR))
4182 log.warning(LintCategory.MISSING_EXPLICIT_CTOR,
4183 pos, Warnings.MissingExplicitCtor(c, pkg, modle));
4184 });
4185 } else {
4186 return;
4187 }
4188 }
4189 }
4190 }
4191 }
4192 return;
4193 }
4194
4195 private class ConversionWarner extends Warner {
4196 final String uncheckedKey;
4197 final Type found;
4198 final Type expected;
4199 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
4200 super(pos);
4201 this.uncheckedKey = uncheckedKey;
4202 this.found = found;
4203 this.expected = expected;
4204 }
4205
4206 @Override
4207 public void warn(LintCategory lint) {
4208 boolean warned = this.warned;
4209 super.warn(lint);
4210 if (warned) return; // suppress redundant diagnostics
4211 switch (lint) {
4212 case UNCHECKED:
4213 Check.this.warnUnchecked(pos(), Warnings.ProbFoundReq(diags.fragment(uncheckedKey), found, expected));
4214 break;
4215 case VARARGS:
4216 if (method != null &&
4217 method.attribute(syms.trustMeType.tsym) != null &&
4218 isTrustMeAllowedOnMethod(method) &&
4219 !types.isReifiable(method.type.getParameterTypes().last())) {
4220 Check.this.warnUnsafeVararg(pos(), Warnings.VarargsUnsafeUseVarargsParam(method.params.last()));
4221 }
4222 break;
4223 default:
4224 throw new AssertionError("Unexpected lint: " + lint);
4225 }
4226 }
4227 }
4228
4229 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
4230 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
4231 }
4232
4233 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
4234 return new ConversionWarner(pos, "unchecked.assign", found, expected);
4235 }
4236
4237 public void checkFunctionalInterface(JCClassDecl tree, ClassSymbol cs) {
4238 Compound functionalType = cs.attribute(syms.functionalInterfaceType.tsym);
4239
4240 if (functionalType != null) {
4241 try {
4242 types.findDescriptorSymbol((TypeSymbol)cs);
4243 } catch (Types.FunctionDescriptorLookupError ex) {
4244 DiagnosticPosition pos = tree.pos();
4245 for (JCAnnotation a : tree.getModifiers().annotations) {
4246 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
4247 pos = a.pos();
4248 break;
4249 }
4250 }
4251 log.error(pos, Errors.BadFunctionalIntfAnno1(ex.getDiagnostic()));
4252 }
4253 }
4254 }
4255
4256 public void checkImportsResolvable(final JCCompilationUnit toplevel) {
4257 for (final JCImport imp : toplevel.getImports()) {
4258 if (!imp.staticImport || !imp.qualid.hasTag(SELECT))
4259 continue;
4260 final JCFieldAccess select = (JCFieldAccess) imp.qualid;
4261 final Symbol origin;
4262 if (select.name == names.asterisk || (origin = TreeInfo.symbol(select.selected)) == null || origin.kind != TYP)
4263 continue;
4264
4265 TypeSymbol site = (TypeSymbol) TreeInfo.symbol(select.selected);
4266 if (!checkTypeContainsImportableElement(site, site, toplevel.packge, select.name, new HashSet<Symbol>())) {
4267 log.error(imp.pos(),
4268 Errors.CantResolveLocation(KindName.STATIC,
4269 select.name,
4270 null,
4271 null,
4272 Fragments.Location(kindName(site),
4273 site,
4274 null)));
4275 }
4276 }
4277 }
4278
4279 // Check that packages imported are in scope (JLS 7.4.3, 6.3, 6.5.3.1, 6.5.3.2)
4280 public void checkImportedPackagesObservable(final JCCompilationUnit toplevel) {
4281 OUTER: for (JCImport imp : toplevel.getImports()) {
4282 if (!imp.staticImport && TreeInfo.name(imp.qualid) == names.asterisk) {
4283 TypeSymbol tsym = ((JCFieldAccess)imp.qualid).selected.type.tsym;
4284 if (tsym.kind == PCK && tsym.members().isEmpty() &&
4285 !(Feature.IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES.allowedInSource(source) && tsym.exists())) {
4286 log.error(DiagnosticFlag.RESOLVE_ERROR, imp.pos, Errors.DoesntExist(tsym));
4287 }
4288 }
4289 }
4290 }
4291
4292 private boolean checkTypeContainsImportableElement(TypeSymbol tsym, TypeSymbol origin, PackageSymbol packge, Name name, Set<Symbol> processed) {
4293 if (tsym == null || !processed.add(tsym))
4294 return false;
4295
4296 // also search through inherited names
4297 if (checkTypeContainsImportableElement(types.supertype(tsym.type).tsym, origin, packge, name, processed))
4298 return true;
4299
4300 for (Type t : types.interfaces(tsym.type))
4301 if (checkTypeContainsImportableElement(t.tsym, origin, packge, name, processed))
4302 return true;
4303
4304 for (Symbol sym : tsym.members().getSymbolsByName(name)) {
4305 if (sym.isStatic() &&
4306 importAccessible(sym, packge) &&
4307 sym.isMemberOf(origin, types)) {
4308 return true;
4309 }
4310 }
4311
4312 return false;
4313 }
4314
4315 // is the sym accessible everywhere in packge?
4316 public boolean importAccessible(Symbol sym, PackageSymbol packge) {
4317 try {
4318 int flags = (int)(sym.flags() & AccessFlags);
4319 switch (flags) {
4320 default:
4321 case PUBLIC:
4322 return true;
4323 case PRIVATE:
4324 return false;
4325 case 0:
4326 case PROTECTED:
4327 return sym.packge() == packge;
4328 }
4329 } catch (ClassFinder.BadClassFile err) {
4330 throw err;
4331 } catch (CompletionFailure ex) {
4332 return false;
4333 }
4334 }
4335
4336 public void checkLeaksNotAccessible(Env<AttrContext> env, JCClassDecl check) {
4337 JCCompilationUnit toplevel = env.toplevel;
4338
4339 if ( toplevel.modle == syms.unnamedModule
4340 || toplevel.modle == syms.noModule
4341 || (check.sym.flags() & COMPOUND) != 0) {
4342 return ;
4343 }
4344
4345 ExportsDirective currentExport = findExport(toplevel.packge);
4346
4347 if ( currentExport == null //not exported
4348 || currentExport.modules != null) //don't check classes in qualified export
4349 return ;
4350
4351 new TreeScanner() {
4352 Lint lint = env.info.lint;
4353 boolean inSuperType;
4354
4355 @Override
4356 public void visitBlock(JCBlock tree) {
4357 }
4358 @Override
4359 public void visitMethodDef(JCMethodDecl tree) {
4360 if (!isAPISymbol(tree.sym))
4361 return;
4362 Lint prevLint = lint;
4363 try {
4364 lint = lint.augment(tree.sym);
4365 if (lint.isEnabled(LintCategory.EXPORTS)) {
4366 super.visitMethodDef(tree);
4367 }
4368 } finally {
4369 lint = prevLint;
4370 }
4371 }
4372 @Override
4373 public void visitVarDef(JCVariableDecl tree) {
4374 if (!isAPISymbol(tree.sym) && tree.sym.owner.kind != MTH)
4375 return;
4376 Lint prevLint = lint;
4377 try {
4378 lint = lint.augment(tree.sym);
4379 if (lint.isEnabled(LintCategory.EXPORTS)) {
4380 scan(tree.mods);
4381 scan(tree.vartype);
4382 }
4383 } finally {
4384 lint = prevLint;
4385 }
4386 }
4387 @Override
4388 public void visitClassDef(JCClassDecl tree) {
4389 if (tree != check)
4390 return ;
4391
4392 if (!isAPISymbol(tree.sym))
4393 return ;
4394
4395 Lint prevLint = lint;
4396 try {
4397 lint = lint.augment(tree.sym);
4398 if (lint.isEnabled(LintCategory.EXPORTS)) {
4399 scan(tree.mods);
4400 scan(tree.typarams);
4401 try {
4402 inSuperType = true;
4403 scan(tree.extending);
4404 scan(tree.implementing);
4405 } finally {
4406 inSuperType = false;
4407 }
4408 scan(tree.defs);
4409 }
4410 } finally {
4411 lint = prevLint;
4412 }
4413 }
4414 @Override
4415 public void visitTypeApply(JCTypeApply tree) {
4416 scan(tree.clazz);
4417 boolean oldInSuperType = inSuperType;
4418 try {
4419 inSuperType = false;
4420 scan(tree.arguments);
4421 } finally {
4422 inSuperType = oldInSuperType;
4423 }
4424 }
4425 @Override
4426 public void visitIdent(JCIdent tree) {
4427 Symbol sym = TreeInfo.symbol(tree);
4428 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR)) {
4429 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4430 }
4431 }
4432
4433 @Override
4434 public void visitSelect(JCFieldAccess tree) {
4435 Symbol sym = TreeInfo.symbol(tree);
4436 Symbol sitesym = TreeInfo.symbol(tree.selected);
4437 if (sym.kind == TYP && sitesym.kind == PCK) {
4438 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType);
4439 } else {
4440 super.visitSelect(tree);
4441 }
4442 }
4443
4444 @Override
4445 public void visitAnnotation(JCAnnotation tree) {
4446 if (tree.attribute.type.tsym.getAnnotation(java.lang.annotation.Documented.class) != null)
4447 super.visitAnnotation(tree);
4448 }
4449
4450 }.scan(check);
4451 }
4452 //where:
4453 private ExportsDirective findExport(PackageSymbol pack) {
4454 for (ExportsDirective d : pack.modle.exports) {
4455 if (d.packge == pack)
4456 return d;
4457 }
4458
4459 return null;
4460 }
4461 private boolean isAPISymbol(Symbol sym) {
4462 while (sym.kind != PCK) {
4463 if ((sym.flags() & Flags.PUBLIC) == 0 && (sym.flags() & Flags.PROTECTED) == 0) {
4464 return false;
4465 }
4466 sym = sym.owner;
4467 }
4468 return true;
4469 }
4470 private void checkVisible(DiagnosticPosition pos, Symbol what, PackageSymbol inPackage, boolean inSuperType) {
4471 if (!isAPISymbol(what) && !inSuperType) { //package private/private element
4472 log.warning(LintCategory.EXPORTS, pos, Warnings.LeaksNotAccessible(kindName(what), what, what.packge().modle));
4473 return ;
4474 }
4475
4476 PackageSymbol whatPackage = what.packge();
4477 ExportsDirective whatExport = findExport(whatPackage);
4478 ExportsDirective inExport = findExport(inPackage);
4479
4480 if (whatExport == null) { //package not exported:
4481 log.warning(LintCategory.EXPORTS, pos, Warnings.LeaksNotAccessibleUnexported(kindName(what), what, what.packge().modle));
4482 return ;
4483 }
4484
4485 if (whatExport.modules != null) {
4486 if (inExport.modules == null || !whatExport.modules.containsAll(inExport.modules)) {
4487 log.warning(LintCategory.EXPORTS, pos, Warnings.LeaksNotAccessibleUnexportedQualified(kindName(what), what, what.packge().modle));
4488 }
4489 }
4490
4491 if (whatPackage.modle != inPackage.modle && whatPackage.modle != syms.java_base) {
4492 //check that relativeTo.modle requires transitive what.modle, somehow:
4493 List<ModuleSymbol> todo = List.of(inPackage.modle);
4494
4495 while (todo.nonEmpty()) {
4496 ModuleSymbol current = todo.head;
4497 todo = todo.tail;
4498 if (current == whatPackage.modle)
4499 return ; //OK
4500 if ((current.flags() & Flags.AUTOMATIC_MODULE) != 0)
4501 continue; //for automatic modules, don't look into their dependencies
4502 for (RequiresDirective req : current.requires) {
4503 if (req.isTransitive()) {
4504 todo = todo.prepend(req.module);
4505 }
4506 }
4507 }
4508
4509 log.warning(LintCategory.EXPORTS, pos, Warnings.LeaksNotAccessibleNotRequiredTransitive(kindName(what), what, what.packge().modle));
4510 }
4511 }
4512
4513 void checkModuleExists(final DiagnosticPosition pos, ModuleSymbol msym) {
4514 if (msym.kind != MDL) {
4515 deferredLintHandler.report(() -> {
4516 if (lint.isEnabled(LintCategory.MODULE))
4517 log.warning(LintCategory.MODULE, pos, Warnings.ModuleNotFound(msym));
4518 });
4519 }
4520 }
4521
4522 void checkPackageExistsForOpens(final DiagnosticPosition pos, PackageSymbol packge) {
4523 if (packge.members().isEmpty() &&
4524 ((packge.flags() & Flags.HAS_RESOURCE) == 0)) {
4525 deferredLintHandler.report(() -> {
4526 if (lint.isEnabled(LintCategory.OPENS))
4527 log.warning(pos, Warnings.PackageEmptyOrNotFound(packge));
4528 });
4529 }
4530 }
4531
4532 void checkModuleRequires(final DiagnosticPosition pos, final RequiresDirective rd) {
4533 if ((rd.module.flags() & Flags.AUTOMATIC_MODULE) != 0) {
4534 deferredLintHandler.report(() -> {
4535 if (rd.isTransitive() && lint.isEnabled(LintCategory.REQUIRES_TRANSITIVE_AUTOMATIC)) {
4536 log.warning(pos, Warnings.RequiresTransitiveAutomatic);
4537 } else if (lint.isEnabled(LintCategory.REQUIRES_AUTOMATIC)) {
4538 log.warning(pos, Warnings.RequiresAutomatic);
4539 }
4540 });
4541 }
4542 }
4543
4544 /**
4545 * Verify the case labels conform to the constraints. Checks constraints related
4546 * combinations of patterns and other labels.
4547 *
4548 * @param cases the cases that should be checked.
4549 */
4550 void checkSwitchCaseStructure(List<JCCase> cases) {
4551 boolean wasConstant = false; // Seen a constant in the same case label
4552 boolean wasDefault = false; // Seen a default in the same case label
4553 boolean wasNullPattern = false; // Seen a null pattern in the same case label,
4554 //or fall through from a null pattern
4555 boolean wasPattern = false; // Seen a pattern in the same case label
4556 //or fall through from a pattern
4557 boolean wasTypePattern = false; // Seen a pattern in the same case label
4558 //or fall through from a type pattern
4559 boolean wasNonEmptyFallThrough = false;
4560 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) {
4561 JCCase c = l.head;
4562 for (JCCaseLabel pat : c.labels) {
4563 if (pat.isExpression()) {
4564 JCExpression expr = (JCExpression) pat;
4565 if (TreeInfo.isNull(expr)) {
4566 if (wasPattern && !wasTypePattern && !wasNonEmptyFallThrough) {
4567 log.error(pat.pos(), Errors.FlowsThroughFromPattern);
4568 }
4569 wasNullPattern = true;
4570 } else {
4571 if (wasPattern && !wasNonEmptyFallThrough) {
4572 log.error(pat.pos(), Errors.FlowsThroughFromPattern);
4573 }
4574 wasConstant = true;
4575 }
4576 } else if (pat.hasTag(DEFAULTCASELABEL)) {
4577 if (wasPattern && !wasNonEmptyFallThrough) {
4578 log.error(pat.pos(), Errors.FlowsThroughFromPattern);
4579 }
4580 wasDefault = true;
4581 } else {
4582 boolean isTypePattern = pat.hasTag(BINDINGPATTERN);
4583 if (wasPattern || wasConstant || wasDefault ||
4584 (wasNullPattern && (!isTypePattern || wasNonEmptyFallThrough))) {
4585 log.error(pat.pos(), Errors.FlowsThroughToPattern);
4586 }
4587 wasPattern = true;
4588 wasTypePattern = isTypePattern;
4589 }
4590 }
4591
4592 boolean completesNormally = c.caseKind == CaseTree.CaseKind.STATEMENT ? c.completesNormally
4593 : false;
4594
4595 if (c.stats.nonEmpty()) {
4596 wasConstant = false;
4597 wasDefault = false;
4598 wasNullPattern &= completesNormally;
4599 wasPattern &= completesNormally;
4600 wasTypePattern &= completesNormally;
4601 }
4602
4603 wasNonEmptyFallThrough = c.stats.nonEmpty() && completesNormally;
4604 }
4605 }
4606
4607 /** check if a type is a subtype of Externalizable, if that is available. */
4608 boolean isExternalizable(Type t) {
4609 try {
4610 syms.externalizableType.complete();
4611 }
4612 catch (CompletionFailure e) {
4613 return false;
4614 }
4615 return types.isSubtype(t, syms.externalizableType);
4616 }
4617
4618 /**
4619 * Check structure of serialization declarations.
4620 */
4621 public void checkSerialStructure(JCClassDecl tree, ClassSymbol c) {
4622 (new SerialTypeVisitor()).visit(c, tree);
4623 }
4624
4625 /**
4626 * This visitor will warn if a serialization-related field or
4627 * method is declared in a suspicious or incorrect way. In
4628 * particular, it will warn for cases where the runtime
4629 * serialization mechanism will silently ignore a mis-declared
4630 * entity.
4631 *
4632 * Distinguished serialization-related fields and methods:
4633 *
4634 * Methods:
4635 *
4636 * private void writeObject(ObjectOutputStream stream) throws IOException
4637 * ANY-ACCESS-MODIFIER Object writeReplace() throws ObjectStreamException
4638 *
4639 * private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException
4640 * private void readObjectNoData() throws ObjectStreamException
4641 * ANY-ACCESS-MODIFIER Object readResolve() throws ObjectStreamException
4642 *
4643 * Fields:
4644 *
4645 * private static final long serialVersionUID
4646 * private static final ObjectStreamField[] serialPersistentFields
4647 *
4648 * Externalizable: methods defined on the interface
4649 * public void writeExternal(ObjectOutput) throws IOException
4650 * public void readExternal(ObjectInput) throws IOException
4651 */
4652 private class SerialTypeVisitor extends ElementKindVisitor14<Void, JCClassDecl> {
4653 SerialTypeVisitor() {
4654 this.lint = Check.this.lint;
4655 }
4656
4657 private static final Set<String> serialMethodNames =
4658 Set.of("writeObject", "writeReplace",
4659 "readObject", "readObjectNoData",
4660 "readResolve");
4661
4662 private static final Set<String> serialFieldNames =
4663 Set.of("serialVersionUID", "serialPersistentFields");
4664
4665 // Type of serialPersistentFields
4666 private final Type OSF_TYPE = new Type.ArrayType(syms.objectStreamFieldType, syms.arrayClass);
4667
4668 Lint lint;
4669
4670 @Override
4671 public Void defaultAction(Element e, JCClassDecl p) {
4672 throw new IllegalArgumentException(Objects.requireNonNullElse(e.toString(), ""));
4673 }
4674
4675 @Override
4676 public Void visitType(TypeElement e, JCClassDecl p) {
4677 runUnderLint(e, p, (symbol, param) -> super.visitType(symbol, param));
4678 return null;
4679 }
4680
4681 @Override
4682 public Void visitTypeAsClass(TypeElement e,
4683 JCClassDecl p) {
4684 // Anonymous classes filtered out by caller.
4685
4686 ClassSymbol c = (ClassSymbol)e;
4687
4688 checkCtorAccess(p, c);
4689
4690 // Check for missing serialVersionUID; check *not* done
4691 // for enums or records.
4692 VarSymbol svuidSym = null;
4693 for (Symbol sym : c.members().getSymbolsByName(names.serialVersionUID)) {
4694 if (sym.kind == VAR) {
4695 svuidSym = (VarSymbol)sym;
4696 break;
4697 }
4698 }
4699
4700 if (svuidSym == null) {
4701 log.warning(LintCategory.SERIAL, p.pos(), Warnings.MissingSVUID(c));
4702 }
4703
4704 // Check for serialPersistentFields to gate checks for
4705 // non-serializable non-transient instance fields
4706 boolean serialPersistentFieldsPresent =
4707 c.members()
4708 .getSymbolsByName(names.serialPersistentFields, sym -> sym.kind == VAR)
4709 .iterator()
4710 .hasNext();
4711
4712 // Check declarations of serialization-related methods and
4713 // fields
4714 for(Symbol el : c.getEnclosedElements()) {
4715 runUnderLint(el, p, (enclosed, tree) -> {
4716 String name = null;
4717 switch(enclosed.getKind()) {
4718 case FIELD -> {
4719 if (!serialPersistentFieldsPresent) {
4720 var flags = enclosed.flags();
4721 if ( ((flags & TRANSIENT) == 0) &&
4722 ((flags & STATIC) == 0)) {
4723 Type varType = enclosed.asType();
4724 if (!canBeSerialized(varType)) {
4725 // Note per JLS arrays are
4726 // serializable even if the
4727 // component type is not.
4728 log.warning(LintCategory.SERIAL,
4729 TreeInfo.diagnosticPositionFor(enclosed, tree),
4730 Warnings.NonSerializableInstanceField);
4731 } else if (varType.hasTag(ARRAY)) {
4732 ArrayType arrayType = (ArrayType)varType;
4733 Type elementType = arrayType.elemtype;
4734 while (elementType.hasTag(ARRAY)) {
4735 arrayType = (ArrayType)elementType;
4736 elementType = arrayType.elemtype;
4737 }
4738 if (!canBeSerialized(elementType)) {
4739 log.warning(LintCategory.SERIAL,
4740 TreeInfo.diagnosticPositionFor(enclosed, tree),
4741 Warnings.NonSerializableInstanceFieldArray(elementType));
4742 }
4743 }
4744 }
4745 }
4746
4747 name = enclosed.getSimpleName().toString();
4748 if (serialFieldNames.contains(name)) {
4749 VarSymbol field = (VarSymbol)enclosed;
4750 switch (name) {
4751 case "serialVersionUID" -> checkSerialVersionUID(tree, e, field);
4752 case "serialPersistentFields" -> checkSerialPersistentFields(tree, e, field);
4753 default -> throw new AssertionError();
4754 }
4755 }
4756 }
4757
4758 // Correctly checking the serialization-related
4759 // methods is subtle. For the methods declared to be
4760 // private or directly declared in the class, the
4761 // enclosed elements of the class can be checked in
4762 // turn. However, writeReplace and readResolve can be
4763 // declared in a superclass and inherited. Note that
4764 // the runtime lookup walks the superclass chain
4765 // looking for writeReplace/readResolve via
4766 // Class.getDeclaredMethod. This differs from calling
4767 // Elements.getAllMembers(TypeElement) as the latter
4768 // will also pull in default methods from
4769 // superinterfaces. In other words, the runtime checks
4770 // (which long predate default methods on interfaces)
4771 // do not admit the possibility of inheriting methods
4772 // this way, a difference from general inheritance.
4773
4774 // The current implementation just checks the enclosed
4775 // elements and does not directly check the inherited
4776 // methods. If all the types are being checked this is
4777 // less of a concern; however, there are cases that
4778 // could be missed. In particular, readResolve and
4779 // writeReplace could, in principle, by inherited from
4780 // a non-serializable superclass and thus not checked
4781 // even if compiled with a serializable child class.
4782 case METHOD -> {
4783 var method = (MethodSymbol)enclosed;
4784 name = method.getSimpleName().toString();
4785 if (serialMethodNames.contains(name)) {
4786 switch (name) {
4787 case "writeObject" -> checkWriteObject(tree, e, method);
4788 case "writeReplace" -> checkWriteReplace(tree,e, method);
4789 case "readObject" -> checkReadObject(tree,e, method);
4790 case "readObjectNoData" -> checkReadObjectNoData(tree, e, method);
4791 case "readResolve" -> checkReadResolve(tree, e, method);
4792 default -> throw new AssertionError();
4793 }
4794 }
4795 }
4796 }
4797 });
4798 }
4799
4800 return null;
4801 }
4802
4803 boolean canBeSerialized(Type type) {
4804 return type.isPrimitive() || rs.isSerializable(type);
4805 }
4806
4807 /**
4808 * Check that Externalizable class needs a public no-arg
4809 * constructor.
4810 *
4811 * Check that a Serializable class has access to the no-arg
4812 * constructor of its first nonserializable superclass.
4813 */
4814 private void checkCtorAccess(JCClassDecl tree, ClassSymbol c) {
4815 if (isExternalizable(c.type)) {
4816 for(var sym : c.getEnclosedElements()) {
4817 if (sym.isConstructor() &&
4818 ((sym.flags() & PUBLIC) == PUBLIC)) {
4819 if (((MethodSymbol)sym).getParameters().isEmpty()) {
4820 return;
4821 }
4822 }
4823 }
4824 log.warning(LintCategory.SERIAL, tree.pos(),
4825 Warnings.ExternalizableMissingPublicNoArgCtor);
4826 } else {
4827 // Approximate access to the no-arg constructor up in
4828 // the superclass chain by checking that the
4829 // constructor is not private. This may not handle
4830 // some cross-package situations correctly.
4831 Type superClass = c.getSuperclass();
4832 // java.lang.Object is *not* Serializable so this loop
4833 // should terminate.
4834 while (rs.isSerializable(superClass) ) {
4835 try {
4836 superClass = (Type)((TypeElement)(((DeclaredType)superClass)).asElement()).getSuperclass();
4837 } catch(ClassCastException cce) {
4838 return ; // Don't try to recover
4839 }
4840 }
4841 // Non-Serializable super class
4842 try {
4843 ClassSymbol supertype = ((ClassSymbol)(((DeclaredType)superClass).asElement()));
4844 for(var sym : supertype.getEnclosedElements()) {
4845 if (sym.isConstructor()) {
4846 MethodSymbol ctor = (MethodSymbol)sym;
4847 if (ctor.getParameters().isEmpty()) {
4848 if (((ctor.flags() & PRIVATE) == PRIVATE) ||
4849 // Handle nested classes and implicit this$0
4850 (supertype.getNestingKind() == NestingKind.MEMBER &&
4851 ((supertype.flags() & STATIC) == 0)))
4852 log.warning(LintCategory.SERIAL, tree.pos(),
4853 Warnings.SerializableMissingAccessNoArgCtor(supertype.getQualifiedName()));
4854 }
4855 }
4856 }
4857 } catch (ClassCastException cce) {
4858 return ; // Don't try to recover
4859 }
4860 return;
4861 }
4862 }
4863
4864 private void checkSerialVersionUID(JCClassDecl tree, Element e, VarSymbol svuid) {
4865 // To be effective, serialVersionUID must be marked static
4866 // and final, but private is recommended. But alas, in
4867 // practice there are many non-private serialVersionUID
4868 // fields.
4869 if ((svuid.flags() & (STATIC | FINAL)) !=
4870 (STATIC | FINAL)) {
4871 log.warning(LintCategory.SERIAL,
4872 TreeInfo.diagnosticPositionFor(svuid, tree),
4873 Warnings.ImproperSVUID((Symbol)e));
4874 }
4875
4876 // check svuid has type long
4877 if (!svuid.type.hasTag(LONG)) {
4878 log.warning(LintCategory.SERIAL,
4879 TreeInfo.diagnosticPositionFor(svuid, tree),
4880 Warnings.LongSVUID((Symbol)e));
4881 }
4882
4883 if (svuid.getConstValue() == null)
4884 log.warning(LintCategory.SERIAL,
4885 TreeInfo.diagnosticPositionFor(svuid, tree),
4886 Warnings.ConstantSVUID((Symbol)e));
4887 }
4888
4889 private void checkSerialPersistentFields(JCClassDecl tree, Element e, VarSymbol spf) {
4890 // To be effective, serialPersisentFields must be private, static, and final.
4891 if ((spf.flags() & (PRIVATE | STATIC | FINAL)) !=
4892 (PRIVATE | STATIC | FINAL)) {
4893 log.warning(LintCategory.SERIAL,
4894 TreeInfo.diagnosticPositionFor(spf, tree), Warnings.ImproperSPF);
4895 }
4896
4897 if (!types.isSameType(spf.type, OSF_TYPE)) {
4898 log.warning(LintCategory.SERIAL,
4899 TreeInfo.diagnosticPositionFor(spf, tree), Warnings.OSFArraySPF);
4900 }
4901
4902 if (isExternalizable((Type)(e.asType()))) {
4903 log.warning(LintCategory.SERIAL, tree.pos(),
4904 Warnings.IneffectualSerialFieldExternalizable);
4905 }
4906
4907 // Warn if serialPersistentFields is initialized to a
4908 // literal null.
4909 JCTree spfDecl = TreeInfo.declarationFor(spf, tree);
4910 if (spfDecl != null && spfDecl.getTag() == VARDEF) {
4911 JCVariableDecl variableDef = (JCVariableDecl) spfDecl;
4912 JCExpression initExpr = variableDef.init;
4913 if (initExpr != null && TreeInfo.isNull(initExpr)) {
4914 log.warning(LintCategory.SERIAL, initExpr.pos(),
4915 Warnings.SPFNullInit);
4916 }
4917 }
4918 }
4919
4920 private void checkWriteObject(JCClassDecl tree, Element e, MethodSymbol method) {
4921 // The "synchronized" modifier is seen in the wild on
4922 // readObject and writeObject methods and is generally
4923 // innocuous.
4924
4925 // private void writeObject(ObjectOutputStream stream) throws IOException
4926 checkPrivateNonStaticMethod(tree, method);
4927 checkReturnType(tree, e, method, syms.voidType);
4928 checkOneArg(tree, e, method, syms.objectOutputStreamType);
4929 checkExceptions(tree, e, method, syms.ioExceptionType);
4930 checkExternalizable(tree, e, method);
4931 }
4932
4933 private void checkWriteReplace(JCClassDecl tree, Element e, MethodSymbol method) {
4934 // ANY-ACCESS-MODIFIER Object writeReplace() throws
4935 // ObjectStreamException
4936
4937 // Excluding abstract, could have a more complicated
4938 // rule based on abstract-ness of the class
4939 checkConcreteInstanceMethod(tree, e, method);
4940 checkReturnType(tree, e, method, syms.objectType);
4941 checkNoArgs(tree, e, method);
4942 checkExceptions(tree, e, method, syms.objectStreamExceptionType);
4943 }
4944
4945 private void checkReadObject(JCClassDecl tree, Element e, MethodSymbol method) {
4946 // The "synchronized" modifier is seen in the wild on
4947 // readObject and writeObject methods and is generally
4948 // innocuous.
4949
4950 // private void readObject(ObjectInputStream stream)
4951 // throws IOException, ClassNotFoundException
4952 checkPrivateNonStaticMethod(tree, method);
4953 checkReturnType(tree, e, method, syms.voidType);
4954 checkOneArg(tree, e, method, syms.objectInputStreamType);
4955 checkExceptions(tree, e, method, syms.ioExceptionType, syms.classNotFoundExceptionType);
4956 checkExternalizable(tree, e, method);
4957 }
4958
4959 private void checkReadObjectNoData(JCClassDecl tree, Element e, MethodSymbol method) {
4960 // private void readObjectNoData() throws ObjectStreamException
4961 checkPrivateNonStaticMethod(tree, method);
4962 checkReturnType(tree, e, method, syms.voidType);
4963 checkNoArgs(tree, e, method);
4964 checkExceptions(tree, e, method, syms.objectStreamExceptionType);
4965 checkExternalizable(tree, e, method);
4966 }
4967
4968 private void checkReadResolve(JCClassDecl tree, Element e, MethodSymbol method) {
4969 // ANY-ACCESS-MODIFIER Object readResolve()
4970 // throws ObjectStreamException
4971
4972 // Excluding abstract, could have a more complicated
4973 // rule based on abstract-ness of the class
4974 checkConcreteInstanceMethod(tree, e, method);
4975 checkReturnType(tree,e, method, syms.objectType);
4976 checkNoArgs(tree, e, method);
4977 checkExceptions(tree, e, method, syms.objectStreamExceptionType);
4978 }
4979
4980 void checkPrivateNonStaticMethod(JCClassDecl tree, MethodSymbol method) {
4981 var flags = method.flags();
4982 if ((flags & PRIVATE) == 0) {
4983 log.warning(LintCategory.SERIAL,
4984 TreeInfo.diagnosticPositionFor(method, tree),
4985 Warnings.SerialMethodNotPrivate(method.getSimpleName()));
4986 }
4987
4988 if ((flags & STATIC) != 0) {
4989 log.warning(LintCategory.SERIAL,
4990 TreeInfo.diagnosticPositionFor(method, tree),
4991 Warnings.SerialMethodStatic(method.getSimpleName()));
4992 }
4993 }
4994
4995 /**
4996 * Per section 1.12 "Serialization of Enum Constants" of
4997 * the serialization specification, due to the special
4998 * serialization handling of enums, any writeObject,
4999 * readObject, writeReplace, and readResolve methods are
5000 * ignored as are serialPersistentFields and
5001 * serialVersionUID fields.
5002 */
5003 @Override
5004 public Void visitTypeAsEnum(TypeElement e,
5005 JCClassDecl p) {
5006 for(Element el : e.getEnclosedElements()) {
5007 runUnderLint(el, p, (enclosed, tree) -> {
5008 String name = enclosed.getSimpleName().toString();
5009 switch(enclosed.getKind()) {
5010 case FIELD -> {
5011 if (serialFieldNames.contains(name)) {
5012 log.warning(LintCategory.SERIAL, tree.pos(),
5013 Warnings.IneffectualSerialFieldEnum(name));
5014 }
5015 }
5016
5017 case METHOD -> {
5018 if (serialMethodNames.contains(name)) {
5019 log.warning(LintCategory.SERIAL, tree.pos(),
5020 Warnings.IneffectualSerialMethodEnum(name));
5021 }
5022 }
5023 }
5024 });
5025 }
5026 return null;
5027 }
5028
5029 /**
5030 * Most serialization-related fields and methods on interfaces
5031 * are ineffectual or problematic.
5032 */
5033 @Override
5034 public Void visitTypeAsInterface(TypeElement e,
5035 JCClassDecl p) {
5036 for(Element el : e.getEnclosedElements()) {
5037 runUnderLint(el, p, (enclosed, tree) -> {
5038 String name = null;
5039 switch(enclosed.getKind()) {
5040 case FIELD -> {
5041 var field = (VarSymbol)enclosed;
5042 name = field.getSimpleName().toString();
5043 switch(name) {
5044 case "serialPersistentFields" -> {
5045 log.warning(LintCategory.SERIAL,
5046 TreeInfo.diagnosticPositionFor(field, tree),
5047 Warnings.IneffectualSerialFieldInterface);
5048 }
5049
5050 case "serialVersionUID" -> {
5051 checkSerialVersionUID(tree, e, field);
5052 }
5053 }
5054 }
5055
5056 case METHOD -> {
5057 var method = (MethodSymbol)enclosed;
5058 name = enclosed.getSimpleName().toString();
5059 if (serialMethodNames.contains(name)) {
5060 switch (name) {
5061 case
5062 "readObject",
5063 "readObjectNoData",
5064 "writeObject" -> checkPrivateMethod(tree, e, method);
5065
5066 case
5067 "writeReplace",
5068 "readResolve" -> checkDefaultIneffective(tree, e, method);
5069
5070 default -> throw new AssertionError();
5071 }
5072
5073 }
5074 }
5075 }
5076 });
5077 }
5078
5079 return null;
5080 }
5081
5082 private void checkPrivateMethod(JCClassDecl tree,
5083 Element e,
5084 MethodSymbol method) {
5085 if ((method.flags() & PRIVATE) == 0) {
5086 log.warning(LintCategory.SERIAL,
5087 TreeInfo.diagnosticPositionFor(method, tree),
5088 Warnings.NonPrivateMethodWeakerAccess);
5089 }
5090 }
5091
5092 private void checkDefaultIneffective(JCClassDecl tree,
5093 Element e,
5094 MethodSymbol method) {
5095 if ((method.flags() & DEFAULT) == DEFAULT) {
5096 log.warning(LintCategory.SERIAL,
5097 TreeInfo.diagnosticPositionFor(method, tree),
5098 Warnings.DefaultIneffective);
5099
5100 }
5101 }
5102
5103 @Override
5104 public Void visitTypeAsAnnotationType(TypeElement e,
5105 JCClassDecl p) {
5106 // Per the JLS, annotation types are not serializeable
5107 return null;
5108 }
5109
5110 /**
5111 * From the Java Object Serialization Specification, 1.13
5112 * Serialization of Records:
5113 *
5114 * "The process by which record objects are serialized or
5115 * externalized cannot be customized; any class-specific
5116 * writeObject, readObject, readObjectNoData, writeExternal,
5117 * and readExternal methods defined by record classes are
5118 * ignored during serialization and deserialization. However,
5119 * a substitute object to be serialized or a designate
5120 * replacement may be specified, by the writeReplace and
5121 * readResolve methods, respectively. Any
5122 * serialPersistentFields field declaration is
5123 * ignored. Documenting serializable fields and data for
5124 * record classes is unnecessary, since there is no variation
5125 * in the serial form, other than whether a substitute or
5126 * replacement object is used. The serialVersionUID of a
5127 * record class is 0L unless explicitly declared. The
5128 * requirement for matching serialVersionUID values is waived
5129 * for record classes."
5130 */
5131 @Override
5132 public Void visitTypeAsRecord(TypeElement e,
5133 JCClassDecl p) {
5134 for(Element el : e.getEnclosedElements()) {
5135 runUnderLint(el, p, (enclosed, tree) -> {
5136 String name = enclosed.getSimpleName().toString();
5137 switch(enclosed.getKind()) {
5138 case FIELD -> {
5139 switch(name) {
5140 case "serialPersistentFields" -> {
5141 log.warning(LintCategory.SERIAL, tree.pos(),
5142 Warnings.IneffectualSerialFieldRecord);
5143 }
5144
5145 case "serialVersionUID" -> {
5146 // Could generate additional warning that
5147 // svuid value is not checked to match for
5148 // records.
5149 checkSerialVersionUID(tree, e, (VarSymbol)enclosed);
5150 }
5151
5152 }
5153 }
5154
5155 case METHOD -> {
5156 var method = (MethodSymbol)enclosed;
5157 switch(name) {
5158 case "writeReplace" -> checkWriteReplace(tree, e, method);
5159 case "readResolve" -> checkReadResolve(tree, e, method);
5160 default -> {
5161 if (serialMethodNames.contains(name)) {
5162 log.warning(LintCategory.SERIAL, tree.pos(),
5163 Warnings.IneffectualSerialMethodRecord(name));
5164 }
5165 }
5166 }
5167
5168 }
5169 }
5170 });
5171 }
5172 return null;
5173 }
5174
5175 void checkConcreteInstanceMethod(JCClassDecl tree,
5176 Element enclosing,
5177 MethodSymbol method) {
5178 if ((method.flags() & (STATIC | ABSTRACT)) != 0) {
5179 log.warning(LintCategory.SERIAL,
5180 TreeInfo.diagnosticPositionFor(method, tree),
5181 Warnings.SerialConcreteInstanceMethod(method.getSimpleName()));
5182 }
5183 }
5184
5185 private void checkReturnType(JCClassDecl tree,
5186 Element enclosing,
5187 MethodSymbol method,
5188 Type expectedReturnType) {
5189 // Note: there may be complications checking writeReplace
5190 // and readResolve since they return Object and could, in
5191 // principle, have covariant overrides and any synthetic
5192 // bridge method would not be represented here for
5193 // checking.
5194 Type rtype = method.getReturnType();
5195 if (!types.isSameType(expectedReturnType, rtype)) {
5196 log.warning(LintCategory.SERIAL,
5197 TreeInfo.diagnosticPositionFor(method, tree),
5198 Warnings.SerialMethodUnexpectedReturnType(method.getSimpleName(),
5199 rtype, expectedReturnType));
5200 }
5201 }
5202
5203 private void checkOneArg(JCClassDecl tree,
5204 Element enclosing,
5205 MethodSymbol method,
5206 Type expectedType) {
5207 String name = method.getSimpleName().toString();
5208
5209 var parameters= method.getParameters();
5210
5211 if (parameters.size() != 1) {
5212 log.warning(LintCategory.SERIAL,
5213 TreeInfo.diagnosticPositionFor(method, tree),
5214 Warnings.SerialMethodOneArg(method.getSimpleName(), parameters.size()));
5215 return;
5216 }
5217
5218 Type parameterType = parameters.get(0).asType();
5219 if (!types.isSameType(parameterType, expectedType)) {
5220 log.warning(LintCategory.SERIAL,
5221 TreeInfo.diagnosticPositionFor(method, tree),
5222 Warnings.SerialMethodParameterType(method.getSimpleName(),
5223 expectedType,
5224 parameterType));
5225 }
5226 }
5227
5228 private void checkNoArgs(JCClassDecl tree, Element enclosing, MethodSymbol method) {
5229 var parameters = method.getParameters();
5230 if (!parameters.isEmpty()) {
5231 log.warning(LintCategory.SERIAL,
5232 TreeInfo.diagnosticPositionFor(parameters.get(0), tree),
5233 Warnings.SerialMethodNoArgs(method.getSimpleName()));
5234 }
5235 }
5236
5237 private void checkExternalizable(JCClassDecl tree, Element enclosing, MethodSymbol method) {
5238 // If the enclosing class is externalizable, warn for the method
5239 if (isExternalizable((Type)enclosing.asType())) {
5240 log.warning(LintCategory.SERIAL, tree.pos(),
5241 Warnings.IneffectualSerialMethodExternalizable(method.getSimpleName()));
5242 }
5243 return;
5244 }
5245
5246 private void checkExceptions(JCClassDecl tree,
5247 Element enclosing,
5248 MethodSymbol method,
5249 Type... declaredExceptions) {
5250 for (Type thrownType: method.getThrownTypes()) {
5251 // For each exception in the throws clause of the
5252 // method, if not an Error and not a RuntimeException,
5253 // check if the exception is a subtype of a declared
5254 // exception from the throws clause of the
5255 // serialization method in question.
5256 if (types.isSubtype(thrownType, syms.runtimeExceptionType) ||
5257 types.isSubtype(thrownType, syms.errorType) ) {
5258 continue;
5259 } else {
5260 boolean declared = false;
5261 for (Type declaredException : declaredExceptions) {
5262 if (types.isSubtype(thrownType, declaredException)) {
5263 declared = true;
5264 continue;
5265 }
5266 }
5267 if (!declared) {
5268 log.warning(LintCategory.SERIAL,
5269 TreeInfo.diagnosticPositionFor(method, tree),
5270 Warnings.SerialMethodUnexpectedException(method.getSimpleName(),
5271 thrownType));
5272 }
5273 }
5274 }
5275 return;
5276 }
5277
5278 private <E extends Element> Void runUnderLint(E symbol, JCClassDecl p, BiConsumer<E, JCClassDecl> task) {
5279 Lint prevLint = lint;
5280 try {
5281 lint = lint.augment((Symbol) symbol);
5282
5283 if (lint.isEnabled(LintCategory.SERIAL)) {
5284 task.accept(symbol, p);
5285 }
5286
5287 return null;
5288 } finally {
5289 lint = prevLint;
5290 }
5291 }
5292
5293 }
5294
5295 }