1 /*
2 * Copyright (c) 1999, 2014, 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
30 import javax.tools.JavaFileManager;
31
32 import com.sun.tools.javac.code.*;
33 import com.sun.tools.javac.code.Attribute.Compound;
34 import com.sun.tools.javac.jvm.*;
35 import com.sun.tools.javac.tree.*;
36 import com.sun.tools.javac.util.*;
37 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
38 import com.sun.tools.javac.util.List;
39
40 import com.sun.tools.javac.code.Lint;
41 import com.sun.tools.javac.code.Lint.LintCategory;
42 import com.sun.tools.javac.code.Type.*;
43 import com.sun.tools.javac.code.Symbol.*;
44 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
45 import com.sun.tools.javac.comp.Infer.InferenceContext;
46 import com.sun.tools.javac.comp.Infer.FreeTypeListener;
47 import com.sun.tools.javac.tree.JCTree.*;
48 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
49
50 import static com.sun.tools.javac.code.Flags.*;
51 import static com.sun.tools.javac.code.Flags.ANNOTATION;
52 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED;
53 import static com.sun.tools.javac.code.Kinds.*;
54 import static com.sun.tools.javac.code.TypeTag.*;
55 import static com.sun.tools.javac.code.TypeTag.WILDCARD;
56
57 import static com.sun.tools.javac.tree.JCTree.Tag.*;
58
59 /** Type checking helper class for the attribution phase.
60 *
61 * <p><b>This is NOT part of any supported API.
62 * If you write code that depends on this, you do so at your own risk.
63 * This code and its internal interfaces are subject to change or
64 * deletion without notice.</b>
65 */
66 public class Check {
67 protected static final Context.Key<Check> checkKey = new Context.Key<>();
68
69 private final Names names;
70 private final Log log;
71 private final Resolve rs;
72 private final Symtab syms;
73 private final Enter enter;
74 private final DeferredAttr deferredAttr;
75 private final Infer infer;
76 private final Types types;
77 private final JCDiagnostic.Factory diags;
78 private boolean warnOnSyntheticConflicts;
79 private boolean suppressAbortOnBadClassFile;
80 private boolean enableSunApiLintControl;
81 private final TreeInfo treeinfo;
82 private final JavaFileManager fileManager;
83 private final Profile profile;
84 private final boolean warnOnAccessToSensitiveMembers;
85
86 // The set of lint options currently in effect. It is initialized
87 // from the context, and then is set/reset as needed by Attr as it
88 // visits all the various parts of the trees during attribution.
89 private Lint lint;
90
91 // The method being analyzed in Attr - it is set/reset as needed by
92 // Attr as it visits new method declarations.
93 private MethodSymbol method;
94
95 public static Check instance(Context context) {
96 Check instance = context.get(checkKey);
97 if (instance == null)
98 instance = new Check(context);
99 return instance;
100 }
101
102 protected Check(Context context) {
103 context.put(checkKey, this);
104
105 names = Names.instance(context);
106 dfltTargetMeta = new Name[] { names.PACKAGE, names.TYPE,
107 names.FIELD, names.METHOD, names.CONSTRUCTOR,
108 names.ANNOTATION_TYPE, names.LOCAL_VARIABLE, names.PARAMETER};
109 log = Log.instance(context);
110 rs = Resolve.instance(context);
111 syms = Symtab.instance(context);
112 enter = Enter.instance(context);
113 deferredAttr = DeferredAttr.instance(context);
114 infer = Infer.instance(context);
115 types = Types.instance(context);
116 diags = JCDiagnostic.Factory.instance(context);
117 Options options = Options.instance(context);
118 lint = Lint.instance(context);
119 treeinfo = TreeInfo.instance(context);
120 fileManager = context.get(JavaFileManager.class);
121
122 Source source = Source.instance(context);
123 allowGenerics = source.allowGenerics();
124 allowVarargs = source.allowVarargs();
125 allowAnnotations = source.allowAnnotations();
126 allowCovariantReturns = source.allowCovariantReturns();
127 allowSimplifiedVarargs = source.allowSimplifiedVarargs();
128 allowDefaultMethods = source.allowDefaultMethods();
129 allowStrictMethodClashCheck = source.allowStrictMethodClashCheck();
130 complexInference = options.isSet("complexinference");
131 warnOnSyntheticConflicts = options.isSet("warnOnSyntheticConflicts");
132 suppressAbortOnBadClassFile = options.isSet("suppressAbortOnBadClassFile");
133 enableSunApiLintControl = options.isSet("enableSunApiLintControl");
134 warnOnAccessToSensitiveMembers = options.isSet("warnOnAccessToSensitiveMembers");
135
136 Target target = Target.instance(context);
137 syntheticNameChar = target.syntheticNameChar();
138
139 profile = Profile.instance(context);
140
141 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
142 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
143 boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
144 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
145
146 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
147 enforceMandatoryWarnings, "deprecated", LintCategory.DEPRECATION);
148 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
149 enforceMandatoryWarnings, "unchecked", LintCategory.UNCHECKED);
150 sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
151 enforceMandatoryWarnings, "sunapi", null);
152
153 deferredLintHandler = DeferredLintHandler.instance(context);
154 }
155
156 /** Switch: generics enabled?
157 */
158 boolean allowGenerics;
159
160 /** Switch: varargs enabled?
161 */
162 boolean allowVarargs;
163
164 /** Switch: annotations enabled?
165 */
166 boolean allowAnnotations;
167
168 /** Switch: covariant returns enabled?
169 */
170 boolean allowCovariantReturns;
171
172 /** Switch: simplified varargs enabled?
173 */
174 boolean allowSimplifiedVarargs;
175
176 /** Switch: default methods enabled?
177 */
178 boolean allowDefaultMethods;
179
180 /** Switch: should unrelated return types trigger a method clash?
181 */
182 boolean allowStrictMethodClashCheck;
183
184 /** Switch: -complexinference option set?
185 */
186 boolean complexInference;
187
188 /** Character for synthetic names
189 */
190 char syntheticNameChar;
191
192 /** A table mapping flat names of all compiled classes in this run to their
193 * symbols; maintained from outside.
194 */
195 public Map<Name,ClassSymbol> compiled = new HashMap<>();
196
197 /** A handler for messages about deprecated usage.
198 */
199 private MandatoryWarningHandler deprecationHandler;
200
201 /** A handler for messages about unchecked or unsafe usage.
202 */
203 private MandatoryWarningHandler uncheckedHandler;
204
205 /** A handler for messages about using proprietary API.
206 */
207 private MandatoryWarningHandler sunApiHandler;
208
209 /** A handler for deferred lint warnings.
210 */
211 private DeferredLintHandler deferredLintHandler;
212
213 /* *************************************************************************
214 * Errors and Warnings
215 **************************************************************************/
216
217 Lint setLint(Lint newLint) {
218 Lint prev = lint;
219 lint = newLint;
220 return prev;
221 }
222
223 MethodSymbol setMethod(MethodSymbol newMethod) {
224 MethodSymbol prev = method;
225 method = newMethod;
226 return prev;
227 }
228
229 /** Warn about deprecated symbol.
230 * @param pos Position to be used for error reporting.
231 * @param sym The deprecated symbol.
232 */
233 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
234 if (!lint.isSuppressed(LintCategory.DEPRECATION))
235 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
236 }
237
238 /** Warn about unchecked operation.
239 * @param pos Position to be used for error reporting.
240 * @param msg A string describing the problem.
241 */
242 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
243 if (!lint.isSuppressed(LintCategory.UNCHECKED))
244 uncheckedHandler.report(pos, msg, args);
245 }
246
247 /** Warn about unsafe vararg method decl.
248 * @param pos Position to be used for error reporting.
249 */
250 void warnUnsafeVararg(DiagnosticPosition pos, String key, Object... args) {
251 if (lint.isEnabled(LintCategory.VARARGS) && allowSimplifiedVarargs)
252 log.warning(LintCategory.VARARGS, pos, key, args);
253 }
254
255 /** Warn about using proprietary API.
256 * @param pos Position to be used for error reporting.
257 * @param msg A string describing the problem.
258 */
259 public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
260 if (!lint.isSuppressed(LintCategory.SUNAPI))
261 sunApiHandler.report(pos, msg, args);
262 }
263
264 public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
265 if (lint.isEnabled(LintCategory.STATIC))
266 log.warning(LintCategory.STATIC, pos, msg, args);
267 }
268
269 /**
270 * Report any deferred diagnostics.
271 */
272 public void reportDeferredDiagnostics() {
273 deprecationHandler.reportDeferredDiagnostic();
274 uncheckedHandler.reportDeferredDiagnostic();
275 sunApiHandler.reportDeferredDiagnostic();
276 }
277
278
279 /** Report a failure to complete a class.
280 * @param pos Position to be used for error reporting.
281 * @param ex The failure to report.
282 */
283 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
284 log.error(JCDiagnostic.DiagnosticFlag.NON_DEFERRABLE, pos, "cant.access", ex.sym, ex.getDetailValue());
285 if (ex instanceof ClassFinder.BadClassFile
286 && !suppressAbortOnBadClassFile) throw new Abort();
287 else return syms.errType;
288 }
289
290 /** Report an error that wrong type tag was found.
291 * @param pos Position to be used for error reporting.
292 * @param required An internationalized string describing the type tag
293 * required.
294 * @param found The type that was found.
295 */
296 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
297 // this error used to be raised by the parser,
298 // but has been delayed to this point:
299 if (found instanceof Type && ((Type)found).hasTag(VOID)) {
300 log.error(pos, "illegal.start.of.type");
301 return syms.errType;
302 }
303 log.error(pos, "type.found.req", found, required);
304 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
305 }
306
307 /** Report an error that symbol cannot be referenced before super
308 * has been called.
309 * @param pos Position to be used for error reporting.
310 * @param sym The referenced symbol.
311 */
312 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
313 log.error(pos, "cant.ref.before.ctor.called", sym);
314 }
315
316 /** Report duplicate declaration error.
317 */
318 void duplicateError(DiagnosticPosition pos, Symbol sym) {
319 if (!sym.type.isErroneous()) {
320 Symbol location = sym.location();
321 if (location.kind == MTH &&
322 ((MethodSymbol)location).isStaticOrInstanceInit()) {
323 log.error(pos, "already.defined.in.clinit", kindName(sym), sym,
324 kindName(sym.location()), kindName(sym.location().enclClass()),
325 sym.location().enclClass());
326 } else {
327 log.error(pos, "already.defined", kindName(sym), sym,
328 kindName(sym.location()), sym.location());
329 }
330 }
331 }
332
333 /** Report array/varargs duplicate declaration
334 */
335 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
336 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
337 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
338 }
339 }
340
341 /* ************************************************************************
342 * duplicate declaration checking
343 *************************************************************************/
344
345 /** Check that variable does not hide variable with same name in
346 * immediately enclosing local scope.
347 * @param pos Position for error reporting.
348 * @param v The symbol.
349 * @param s The scope.
350 */
351 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
352 if (s.next != null) {
353 for (Scope.Entry e = s.next.lookup(v.name);
354 e.scope != null && e.sym.owner == v.owner;
355 e = e.next()) {
356 if (e.sym.kind == VAR &&
357 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
358 v.name != names.error) {
359 duplicateError(pos, e.sym);
360 return;
361 }
362 }
363 }
364 }
365
366 /** Check that a class or interface does not hide a class or
367 * interface with same name in immediately enclosing local scope.
368 * @param pos Position for error reporting.
369 * @param c The symbol.
370 * @param s The scope.
371 */
372 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
373 if (s.next != null) {
374 for (Scope.Entry e = s.next.lookup(c.name);
375 e.scope != null && e.sym.owner == c.owner;
376 e = e.next()) {
377 if (e.sym.kind == TYP && !e.sym.type.hasTag(TYPEVAR) &&
378 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
379 c.name != names.error) {
380 duplicateError(pos, e.sym);
381 return;
382 }
383 }
384 }
385 }
386
387 /** Check that class does not have the same name as one of
388 * its enclosing classes, or as a class defined in its enclosing scope.
389 * return true if class is unique in its enclosing scope.
390 * @param pos Position for error reporting.
391 * @param name The class name.
392 * @param s The enclosing scope.
393 */
394 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
395 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
396 if (e.sym.kind == TYP && e.sym.name != names.error) {
397 duplicateError(pos, e.sym);
398 return false;
399 }
400 }
401 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
402 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
403 duplicateError(pos, sym);
404 return true;
405 }
406 }
407 return true;
408 }
409
410 /* *************************************************************************
411 * Class name generation
412 **************************************************************************/
413
414 /** Return name of local class.
415 * This is of the form {@code <enclClass> $ n <classname> }
416 * where
417 * enclClass is the flat name of the enclosing class,
418 * classname is the simple name of the local class
419 */
420 Name localClassName(ClassSymbol c) {
421 for (int i=1; ; i++) {
422 Name flatname = names.
423 fromString("" + c.owner.enclClass().flatname +
424 syntheticNameChar + i +
425 c.name);
426 if (compiled.get(flatname) == null) return flatname;
427 }
428 }
429
430 public void newRound() {
431 compiled.clear();
432 }
433
434 /* *************************************************************************
435 * Type Checking
436 **************************************************************************/
437
438 /**
439 * A check context is an object that can be used to perform compatibility
440 * checks - depending on the check context, meaning of 'compatibility' might
441 * vary significantly.
442 */
443 public interface CheckContext {
444 /**
445 * Is type 'found' compatible with type 'req' in given context
446 */
447 boolean compatible(Type found, Type req, Warner warn);
448 /**
449 * Report a check error
450 */
451 void report(DiagnosticPosition pos, JCDiagnostic details);
452 /**
453 * Obtain a warner for this check context
454 */
455 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req);
456
457 public Infer.InferenceContext inferenceContext();
458
459 public DeferredAttr.DeferredAttrContext deferredAttrContext();
460 }
461
462 /**
463 * This class represent a check context that is nested within another check
464 * context - useful to check sub-expressions. The default behavior simply
465 * redirects all method calls to the enclosing check context leveraging
466 * the forwarding pattern.
467 */
468 static class NestedCheckContext implements CheckContext {
469 CheckContext enclosingContext;
470
471 NestedCheckContext(CheckContext enclosingContext) {
472 this.enclosingContext = enclosingContext;
473 }
474
475 public boolean compatible(Type found, Type req, Warner warn) {
476 return enclosingContext.compatible(found, req, warn);
477 }
478
479 public void report(DiagnosticPosition pos, JCDiagnostic details) {
480 enclosingContext.report(pos, details);
481 }
482
483 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
484 return enclosingContext.checkWarner(pos, found, req);
485 }
486
487 public Infer.InferenceContext inferenceContext() {
488 return enclosingContext.inferenceContext();
489 }
490
491 public DeferredAttrContext deferredAttrContext() {
492 return enclosingContext.deferredAttrContext();
493 }
494 }
495
496 /**
497 * Check context to be used when evaluating assignment/return statements
498 */
499 CheckContext basicHandler = new CheckContext() {
500 public void report(DiagnosticPosition pos, JCDiagnostic details) {
501 log.error(pos, "prob.found.req", details);
502 }
503 public boolean compatible(Type found, Type req, Warner warn) {
504 return types.isAssignable(found, req, warn);
505 }
506
507 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
508 return convertWarner(pos, found, req);
509 }
510
511 public InferenceContext inferenceContext() {
512 return infer.emptyContext;
513 }
514
515 public DeferredAttrContext deferredAttrContext() {
516 return deferredAttr.emptyDeferredAttrContext;
517 }
518
519 @Override
520 public String toString() {
521 return "CheckContext: basicHandler";
522 }
523 };
524
525 /** Check that a given type is assignable to a given proto-type.
526 * If it is, return the type, otherwise return errType.
527 * @param pos Position to be used for error reporting.
528 * @param found The type that was found.
529 * @param req The type that was required.
530 */
531 Type checkType(DiagnosticPosition pos, Type found, Type req) {
532 return checkType(pos, found, req, basicHandler);
533 }
534
535 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) {
536 final Infer.InferenceContext inferenceContext = checkContext.inferenceContext();
537 if (inferenceContext.free(req)) {
538 inferenceContext.addFreeTypeListener(List.of(req), new FreeTypeListener() {
539 @Override
540 public void typesInferred(InferenceContext inferenceContext) {
541 checkType(pos, inferenceContext.asInstType(found), inferenceContext.asInstType(req), checkContext);
542 }
543 });
544 }
545 if (req.hasTag(ERROR))
546 return req;
547 if (req.hasTag(NONE))
548 return found;
549 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) {
550 return found;
551 } else {
552 if (found.isNumeric() && req.isNumeric()) {
553 checkContext.report(pos, diags.fragment("possible.loss.of.precision", found, req));
554 return types.createErrorType(found);
555 }
556 checkContext.report(pos, diags.fragment("inconvertible.types", found, req));
557 return types.createErrorType(found);
558 }
559 }
560
561 /** Check that a given type can be cast to a given target type.
562 * Return the result of the cast.
563 * @param pos Position to be used for error reporting.
564 * @param found The type that is being cast.
565 * @param req The target type of the cast.
566 */
567 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
568 return checkCastable(pos, found, req, basicHandler);
569 }
570 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) {
571 if (types.isCastable(found, req, castWarner(pos, found, req))) {
572 return req;
573 } else {
574 checkContext.report(pos, diags.fragment("inconvertible.types", found, req));
575 return types.createErrorType(found);
576 }
577 }
578
579 /** Check for redundant casts (i.e. where source type is a subtype of target type)
580 * The problem should only be reported for non-292 cast
581 */
582 public void checkRedundantCast(Env<AttrContext> env, final JCTypeCast tree) {
583 if (!tree.type.isErroneous()
584 && types.isSameType(tree.expr.type, tree.clazz.type)
585 && !(ignoreAnnotatedCasts && TreeInfo.containsTypeAnnotation(tree.clazz))
586 && !is292targetTypeCast(tree)) {
587 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
588 @Override
589 public void report() {
590 if (lint.isEnabled(Lint.LintCategory.CAST))
591 log.warning(Lint.LintCategory.CAST,
592 tree.pos(), "redundant.cast", tree.expr.type);
593 }
594 });
595 }
596 }
597 //where
598 private boolean is292targetTypeCast(JCTypeCast tree) {
599 boolean is292targetTypeCast = false;
600 JCExpression expr = TreeInfo.skipParens(tree.expr);
601 if (expr.hasTag(APPLY)) {
602 JCMethodInvocation apply = (JCMethodInvocation)expr;
603 Symbol sym = TreeInfo.symbol(apply.meth);
604 is292targetTypeCast = sym != null &&
605 sym.kind == MTH &&
606 (sym.flags() & HYPOTHETICAL) != 0;
607 }
608 return is292targetTypeCast;
609 }
610
611 private static final boolean ignoreAnnotatedCasts = true;
612
613 /** Check that a type is within some bounds.
614 *
615 * Used in TypeApply to verify that, e.g., X in {@code V<X>} is a valid
616 * type argument.
617 * @param a The type that should be bounded by bs.
618 * @param bound The bound.
619 */
620 private boolean checkExtends(Type a, Type bound) {
621 if (a.isUnbound()) {
622 return true;
623 } else if (!a.hasTag(WILDCARD)) {
624 a = types.cvarUpperBound(a);
625 return types.isSubtype(a, bound);
626 } else if (a.isExtendsBound()) {
627 return types.isCastable(bound, types.wildUpperBound(a), types.noWarnings);
628 } else if (a.isSuperBound()) {
629 return !types.notSoftSubtype(types.wildLowerBound(a), bound);
630 }
631 return true;
632 }
633
634 /** Check that type is different from 'void'.
635 * @param pos Position to be used for error reporting.
636 * @param t The type to be checked.
637 */
638 Type checkNonVoid(DiagnosticPosition pos, Type t) {
639 if (t.hasTag(VOID)) {
640 log.error(pos, "void.not.allowed.here");
641 return types.createErrorType(t);
642 } else {
643 return t;
644 }
645 }
646
647 Type checkClassOrArrayType(DiagnosticPosition pos, Type t) {
648 if (!t.hasTag(CLASS) && !t.hasTag(ARRAY) && !t.hasTag(ERROR)) {
649 return typeTagError(pos,
650 diags.fragment("type.req.class.array"),
651 asTypeParam(t));
652 } else {
653 return t;
654 }
655 }
656
657 /** Check that type is a class or interface type.
658 * @param pos Position to be used for error reporting.
659 * @param t The type to be checked.
660 */
661 Type checkClassType(DiagnosticPosition pos, Type t) {
662 if (!t.hasTag(CLASS) && !t.hasTag(ERROR)) {
663 return typeTagError(pos,
664 diags.fragment("type.req.class"),
665 asTypeParam(t));
666 } else {
667 return t;
668 }
669 }
670 //where
671 private Object asTypeParam(Type t) {
672 return (t.hasTag(TYPEVAR))
673 ? diags.fragment("type.parameter", t)
674 : t;
675 }
676
677 /** Check that type is a valid qualifier for a constructor reference expression
678 */
679 Type checkConstructorRefType(DiagnosticPosition pos, Type t) {
680 t = checkClassOrArrayType(pos, t);
681 if (t.hasTag(CLASS)) {
682 if ((t.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) {
683 log.error(pos, "abstract.cant.be.instantiated", t.tsym);
684 t = types.createErrorType(t);
685 } else if ((t.tsym.flags() & ENUM) != 0) {
686 log.error(pos, "enum.cant.be.instantiated");
687 t = types.createErrorType(t);
688 } else {
689 t = checkClassType(pos, t, true);
690 }
691 } else if (t.hasTag(ARRAY)) {
692 if (!types.isReifiable(((ArrayType)t).elemtype)) {
693 log.error(pos, "generic.array.creation");
694 t = types.createErrorType(t);
695 }
696 }
697 return t;
698 }
699
700 /** Check that type is a class or interface type.
701 * @param pos Position to be used for error reporting.
702 * @param t The type to be checked.
703 * @param noBounds True if type bounds are illegal here.
704 */
705 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
706 t = checkClassType(pos, t);
707 if (noBounds && t.isParameterized()) {
708 List<Type> args = t.getTypeArguments();
709 while (args.nonEmpty()) {
710 if (args.head.hasTag(WILDCARD))
711 return typeTagError(pos,
712 diags.fragment("type.req.exact"),
713 args.head);
714 args = args.tail;
715 }
716 }
717 return t;
718 }
719
720 /** Check that type is a reference type, i.e. a class, interface or array type
721 * or a type variable.
722 * @param pos Position to be used for error reporting.
723 * @param t The type to be checked.
724 */
725 Type checkRefType(DiagnosticPosition pos, Type t) {
726 if (t.isReference())
727 return t;
728 else
729 return typeTagError(pos,
730 diags.fragment("type.req.ref"),
731 t);
732 }
733
734 /** Check that each type is a reference type, i.e. a class, interface or array type
735 * or a type variable.
736 * @param trees Original trees, used for error reporting.
737 * @param types The types to be checked.
738 */
739 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
740 List<JCExpression> tl = trees;
741 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
742 l.head = checkRefType(tl.head.pos(), l.head);
743 tl = tl.tail;
744 }
745 return types;
746 }
747
748 /** Check that type is a null or reference type.
749 * @param pos Position to be used for error reporting.
750 * @param t The type to be checked.
751 */
752 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
753 if (t.isReference() || t.hasTag(BOT))
754 return t;
755 else
756 return typeTagError(pos,
757 diags.fragment("type.req.ref"),
758 t);
759 }
760
761 /** Check that flag set does not contain elements of two conflicting sets. s
762 * Return true if it doesn't.
763 * @param pos Position to be used for error reporting.
764 * @param flags The set of flags to be checked.
765 * @param set1 Conflicting flags set #1.
766 * @param set2 Conflicting flags set #2.
767 */
768 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
769 if ((flags & set1) != 0 && (flags & set2) != 0) {
770 log.error(pos,
771 "illegal.combination.of.modifiers",
772 asFlagSet(TreeInfo.firstFlag(flags & set1)),
773 asFlagSet(TreeInfo.firstFlag(flags & set2)));
774 return false;
775 } else
776 return true;
777 }
778
779 /** Check that usage of diamond operator is correct (i.e. diamond should not
780 * be used with non-generic classes or in anonymous class creation expressions)
781 */
782 Type checkDiamond(JCNewClass tree, Type t) {
783 if (!TreeInfo.isDiamond(tree) ||
784 t.isErroneous()) {
785 return checkClassType(tree.clazz.pos(), t, true);
786 } else if (tree.def != null) {
787 log.error(tree.clazz.pos(),
788 "cant.apply.diamond.1",
789 t, diags.fragment("diamond.and.anon.class", t));
790 return types.createErrorType(t);
791 } else if (t.tsym.type.getTypeArguments().isEmpty()) {
792 log.error(tree.clazz.pos(),
793 "cant.apply.diamond.1",
794 t, diags.fragment("diamond.non.generic", t));
795 return types.createErrorType(t);
796 } else if (tree.typeargs != null &&
797 tree.typeargs.nonEmpty()) {
798 log.error(tree.clazz.pos(),
799 "cant.apply.diamond.1",
800 t, diags.fragment("diamond.and.explicit.params", t));
801 return types.createErrorType(t);
802 } else {
803 return t;
804 }
805 }
806
807 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
808 MethodSymbol m = tree.sym;
809 if (!allowSimplifiedVarargs) return;
810 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
811 Type varargElemType = null;
812 if (m.isVarArgs()) {
813 varargElemType = types.elemtype(tree.params.last().type);
814 }
815 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
816 if (varargElemType != null) {
817 log.error(tree,
818 "varargs.invalid.trustme.anno",
819 syms.trustMeType.tsym,
820 diags.fragment("varargs.trustme.on.virtual.varargs", m));
821 } else {
822 log.error(tree,
823 "varargs.invalid.trustme.anno",
824 syms.trustMeType.tsym,
825 diags.fragment("varargs.trustme.on.non.varargs.meth", m));
826 }
827 } else if (hasTrustMeAnno && varargElemType != null &&
828 types.isReifiable(varargElemType)) {
829 warnUnsafeVararg(tree,
830 "varargs.redundant.trustme.anno",
831 syms.trustMeType.tsym,
832 diags.fragment("varargs.trustme.on.reifiable.varargs", varargElemType));
833 }
834 else if (!hasTrustMeAnno && varargElemType != null &&
835 !types.isReifiable(varargElemType)) {
836 warnUnchecked(tree.params.head.pos(), "unchecked.varargs.non.reifiable.type", varargElemType);
837 }
838 }
839 //where
840 private boolean isTrustMeAllowedOnMethod(Symbol s) {
841 return (s.flags() & VARARGS) != 0 &&
842 (s.isConstructor() ||
843 (s.flags() & (STATIC | FINAL)) != 0);
844 }
845
846 Type checkMethod(final Type mtype,
847 final Symbol sym,
848 final Env<AttrContext> env,
849 final List<JCExpression> argtrees,
850 final List<Type> argtypes,
851 final boolean useVarargs,
852 InferenceContext inferenceContext) {
853 // System.out.println("call : " + env.tree);
854 // System.out.println("method : " + owntype);
855 // System.out.println("actuals: " + argtypes);
856 if (inferenceContext.free(mtype)) {
857 inferenceContext.addFreeTypeListener(List.of(mtype), new FreeTypeListener() {
858 public void typesInferred(InferenceContext inferenceContext) {
859 checkMethod(inferenceContext.asInstType(mtype), sym, env, argtrees, argtypes, useVarargs, inferenceContext);
860 }
861 });
862 return mtype;
863 }
864 Type owntype = mtype;
865 List<Type> formals = owntype.getParameterTypes();
866 List<Type> nonInferred = sym.type.getParameterTypes();
867 if (nonInferred.length() != formals.length()) nonInferred = formals;
868 Type last = useVarargs ? formals.last() : null;
869 if (sym.name == names.init && sym.owner == syms.enumSym) {
870 formals = formals.tail.tail;
871 nonInferred = nonInferred.tail.tail;
872 }
873 List<JCExpression> args = argtrees;
874 if (args != null) {
875 //this is null when type-checking a method reference
876 while (formals.head != last) {
877 JCTree arg = args.head;
878 Warner warn = convertWarner(arg.pos(), arg.type, nonInferred.head);
879 assertConvertible(arg, arg.type, formals.head, warn);
880 args = args.tail;
881 formals = formals.tail;
882 nonInferred = nonInferred.tail;
883 }
884 if (useVarargs) {
885 Type varArg = types.elemtype(last);
886 while (args.tail != null) {
887 JCTree arg = args.head;
888 Warner warn = convertWarner(arg.pos(), arg.type, varArg);
889 assertConvertible(arg, arg.type, varArg, warn);
890 args = args.tail;
891 }
892 } else if ((sym.flags() & (VARARGS | SIGNATURE_POLYMORPHIC)) == VARARGS &&
893 allowVarargs) {
894 // non-varargs call to varargs method
895 Type varParam = owntype.getParameterTypes().last();
896 Type lastArg = argtypes.last();
897 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) &&
898 !types.isSameType(types.erasure(varParam), types.erasure(lastArg)))
899 log.warning(argtrees.last().pos(), "inexact.non-varargs.call",
900 types.elemtype(varParam), varParam);
901 }
902 }
903 if (useVarargs) {
904 Type argtype = owntype.getParameterTypes().last();
905 if (!types.isReifiable(argtype) &&
906 (!allowSimplifiedVarargs ||
907 sym.attribute(syms.trustMeType.tsym) == null ||
908 !isTrustMeAllowedOnMethod(sym))) {
909 warnUnchecked(env.tree.pos(),
910 "unchecked.generic.array.creation",
911 argtype);
912 }
913 if ((sym.baseSymbol().flags() & SIGNATURE_POLYMORPHIC) == 0) {
914 TreeInfo.setVarargsElement(env.tree, types.elemtype(argtype));
915 }
916 }
917 PolyKind pkind = (sym.type.hasTag(FORALL) &&
918 sym.type.getReturnType().containsAny(((ForAll)sym.type).tvars)) ?
919 PolyKind.POLY : PolyKind.STANDALONE;
920 TreeInfo.setPolyKind(env.tree, pkind);
921 return owntype;
922 }
923 //where
924 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) {
925 if (types.isConvertible(actual, formal, warn))
926 return;
927
928 if (formal.isCompound()
929 && types.isSubtype(actual, types.supertype(formal))
930 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn))
931 return;
932 }
933
934 /**
935 * Check that type 't' is a valid instantiation of a generic class
936 * (see JLS 4.5)
937 *
938 * @param t class type to be checked
939 * @return true if 't' is well-formed
940 */
941 public boolean checkValidGenericType(Type t) {
942 return firstIncompatibleTypeArg(t) == null;
943 }
944 //WHERE
945 private Type firstIncompatibleTypeArg(Type type) {
946 List<Type> formals = type.tsym.type.allparams();
947 List<Type> actuals = type.allparams();
948 List<Type> args = type.getTypeArguments();
949 List<Type> forms = type.tsym.type.getTypeArguments();
950 ListBuffer<Type> bounds_buf = new ListBuffer<>();
951
952 // For matching pairs of actual argument types `a' and
953 // formal type parameters with declared bound `b' ...
954 while (args.nonEmpty() && forms.nonEmpty()) {
955 // exact type arguments needs to know their
956 // bounds (for upper and lower bound
957 // calculations). So we create new bounds where
958 // type-parameters are replaced with actuals argument types.
959 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals));
960 args = args.tail;
961 forms = forms.tail;
962 }
963
964 args = type.getTypeArguments();
965 List<Type> tvars_cap = types.substBounds(formals,
966 formals,
967 types.capture(type).allparams());
968 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
969 // Let the actual arguments know their bound
970 args.head.withTypeVar((TypeVar)tvars_cap.head);
971 args = args.tail;
972 tvars_cap = tvars_cap.tail;
973 }
974
975 args = type.getTypeArguments();
976 List<Type> bounds = bounds_buf.toList();
977
978 while (args.nonEmpty() && bounds.nonEmpty()) {
979 Type actual = args.head;
980 if (!isTypeArgErroneous(actual) &&
981 !bounds.head.isErroneous() &&
982 !checkExtends(actual, bounds.head)) {
983 return args.head;
984 }
985 args = args.tail;
986 bounds = bounds.tail;
987 }
988
989 args = type.getTypeArguments();
990 bounds = bounds_buf.toList();
991
992 for (Type arg : types.capture(type).getTypeArguments()) {
993 if (arg.hasTag(TYPEVAR) &&
994 arg.getUpperBound().isErroneous() &&
995 !bounds.head.isErroneous() &&
996 !isTypeArgErroneous(args.head)) {
997 return args.head;
998 }
999 bounds = bounds.tail;
1000 args = args.tail;
1001 }
1002
1003 return null;
1004 }
1005 //where
1006 boolean isTypeArgErroneous(Type t) {
1007 return isTypeArgErroneous.visit(t);
1008 }
1009
1010 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() {
1011 public Boolean visitType(Type t, Void s) {
1012 return t.isErroneous();
1013 }
1014 @Override
1015 public Boolean visitTypeVar(TypeVar t, Void s) {
1016 return visit(t.getUpperBound());
1017 }
1018 @Override
1019 public Boolean visitCapturedType(CapturedType t, Void s) {
1020 return visit(t.getUpperBound()) ||
1021 visit(t.getLowerBound());
1022 }
1023 @Override
1024 public Boolean visitWildcardType(WildcardType t, Void s) {
1025 return visit(t.type);
1026 }
1027 };
1028
1029 /** Check that given modifiers are legal for given symbol and
1030 * return modifiers together with any implicit modifiers for that symbol.
1031 * Warning: we can't use flags() here since this method
1032 * is called during class enter, when flags() would cause a premature
1033 * completion.
1034 * @param pos Position to be used for error reporting.
1035 * @param flags The set of modifiers given in a definition.
1036 * @param sym The defined symbol.
1037 */
1038 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
1039 long mask;
1040 long implicit = 0;
1041
1042 switch (sym.kind) {
1043 case VAR:
1044 if (TreeInfo.isReceiverParam(tree))
1045 mask = ReceiverParamFlags;
1046 else if (sym.owner.kind != TYP)
1047 mask = LocalVarFlags;
1048 else if ((sym.owner.flags_field & INTERFACE) != 0)
1049 mask = implicit = InterfaceVarFlags;
1050 else
1051 mask = VarFlags;
1052 break;
1053 case MTH:
1054 if (sym.name == names.init) {
1055 if ((sym.owner.flags_field & ENUM) != 0) {
1056 // enum constructors cannot be declared public or
1057 // protected and must be implicitly or explicitly
1058 // private
1059 implicit = PRIVATE;
1060 mask = PRIVATE;
1061 } else
1062 mask = ConstructorFlags;
1063 } else if ((sym.owner.flags_field & INTERFACE) != 0) {
1064 if ((sym.owner.flags_field & ANNOTATION) != 0) {
1065 mask = AnnotationTypeElementMask;
1066 implicit = PUBLIC | ABSTRACT;
1067 } else if ((flags & (DEFAULT | STATIC)) != 0) {
1068 mask = InterfaceMethodMask;
1069 implicit = PUBLIC;
1070 if ((flags & DEFAULT) != 0) {
1071 implicit |= ABSTRACT;
1072 }
1073 } else {
1074 mask = implicit = InterfaceMethodFlags;
1075 }
1076 } else {
1077 mask = MethodFlags;
1078 }
1079 // Imply STRICTFP if owner has STRICTFP set.
1080 if (((flags|implicit) & Flags.ABSTRACT) == 0 ||
1081 ((flags) & Flags.DEFAULT) != 0)
1082 implicit |= sym.owner.flags_field & STRICTFP;
1083 break;
1084 case TYP:
1085 if (sym.isLocal()) {
1086 mask = LocalClassFlags;
1087 if (sym.name.isEmpty()) { // Anonymous class
1088 // JLS: Anonymous classes are final.
1089 implicit |= FINAL;
1090 }
1091 if ((sym.owner.flags_field & STATIC) == 0 &&
1092 (flags & ENUM) != 0)
1093 log.error(pos, "enums.must.be.static");
1094 } else if (sym.owner.kind == TYP) {
1095 mask = MemberClassFlags;
1096 if (sym.owner.owner.kind == PCK ||
1097 (sym.owner.flags_field & STATIC) != 0)
1098 mask |= STATIC;
1099 else if ((flags & ENUM) != 0)
1100 log.error(pos, "enums.must.be.static");
1101 // Nested interfaces and enums are always STATIC (Spec ???)
1102 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
1103 } else {
1104 mask = ClassFlags;
1105 }
1106 // Interfaces are always ABSTRACT
1107 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
1108
1109 if ((flags & ENUM) != 0) {
1110 // enums can't be declared abstract or final
1111 mask &= ~(ABSTRACT | FINAL);
1112 implicit |= implicitEnumFinalFlag(tree);
1113 }
1114 // Imply STRICTFP if owner has STRICTFP set.
1115 implicit |= sym.owner.flags_field & STRICTFP;
1116 break;
1117 default:
1118 throw new AssertionError();
1119 }
1120 long illegal = flags & ExtendedStandardFlags & ~mask;
1121 if (illegal != 0) {
1122 if ((illegal & INTERFACE) != 0) {
1123 log.error(pos, "intf.not.allowed.here");
1124 mask |= INTERFACE;
1125 }
1126 else {
1127 log.error(pos,
1128 "mod.not.allowed.here", asFlagSet(illegal));
1129 }
1130 }
1131 else if ((sym.kind == TYP ||
1132 // ISSUE: Disallowing abstract&private is no longer appropriate
1133 // in the presence of inner classes. Should it be deleted here?
1134 checkDisjoint(pos, flags,
1135 ABSTRACT,
1136 PRIVATE | STATIC | DEFAULT))
1137 &&
1138 checkDisjoint(pos, flags,
1139 STATIC,
1140 DEFAULT)
1141 &&
1142 checkDisjoint(pos, flags,
1143 ABSTRACT | INTERFACE,
1144 FINAL | NATIVE | SYNCHRONIZED)
1145 &&
1146 checkDisjoint(pos, flags,
1147 PUBLIC,
1148 PRIVATE | PROTECTED)
1149 &&
1150 checkDisjoint(pos, flags,
1151 PRIVATE,
1152 PUBLIC | PROTECTED)
1153 &&
1154 checkDisjoint(pos, flags,
1155 FINAL,
1156 VOLATILE)
1157 &&
1158 (sym.kind == TYP ||
1159 checkDisjoint(pos, flags,
1160 ABSTRACT | NATIVE,
1161 STRICTFP))) {
1162 // skip
1163 }
1164 return flags & (mask | ~ExtendedStandardFlags) | implicit;
1165 }
1166
1167
1168 /** Determine if this enum should be implicitly final.
1169 *
1170 * If the enum has no specialized enum contants, it is final.
1171 *
1172 * If the enum does have specialized enum contants, it is
1173 * <i>not</i> final.
1174 */
1175 private long implicitEnumFinalFlag(JCTree tree) {
1176 if (!tree.hasTag(CLASSDEF)) return 0;
1177 class SpecialTreeVisitor extends JCTree.Visitor {
1178 boolean specialized;
1179 SpecialTreeVisitor() {
1180 this.specialized = false;
1181 }
1182
1183 @Override
1184 public void visitTree(JCTree tree) { /* no-op */ }
1185
1186 @Override
1187 public void visitVarDef(JCVariableDecl tree) {
1188 if ((tree.mods.flags & ENUM) != 0) {
1189 if (tree.init instanceof JCNewClass &&
1190 ((JCNewClass) tree.init).def != null) {
1191 specialized = true;
1192 }
1193 }
1194 }
1195 }
1196
1197 SpecialTreeVisitor sts = new SpecialTreeVisitor();
1198 JCClassDecl cdef = (JCClassDecl) tree;
1199 for (JCTree defs: cdef.defs) {
1200 defs.accept(sts);
1201 if (sts.specialized) return 0;
1202 }
1203 return FINAL;
1204 }
1205
1206 /* *************************************************************************
1207 * Type Validation
1208 **************************************************************************/
1209
1210 /** Validate a type expression. That is,
1211 * check that all type arguments of a parametric type are within
1212 * their bounds. This must be done in a second phase after type attribution
1213 * since a class might have a subclass as type parameter bound. E.g:
1214 *
1215 * <pre>{@code
1216 * class B<A extends C> { ... }
1217 * class C extends B<C> { ... }
1218 * }</pre>
1219 *
1220 * and we can't make sure that the bound is already attributed because
1221 * of possible cycles.
1222 *
1223 * Visitor method: Validate a type expression, if it is not null, catching
1224 * and reporting any completion failures.
1225 */
1226 void validate(JCTree tree, Env<AttrContext> env) {
1227 validate(tree, env, true);
1228 }
1229 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1230 new Validator(env).validateTree(tree, checkRaw, true);
1231 }
1232
1233 /** Visitor method: Validate a list of type expressions.
1234 */
1235 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1236 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1237 validate(l.head, env);
1238 }
1239
1240 /** A visitor class for type validation.
1241 */
1242 class Validator extends JCTree.Visitor {
1243
1244 boolean checkRaw;
1245 boolean isOuter;
1246 Env<AttrContext> env;
1247
1248 Validator(Env<AttrContext> env) {
1249 this.env = env;
1250 }
1251
1252 @Override
1253 public void visitTypeArray(JCArrayTypeTree tree) {
1254 validateTree(tree.elemtype, checkRaw, isOuter);
1255 }
1256
1257 @Override
1258 public void visitTypeApply(JCTypeApply tree) {
1259 if (tree.type.hasTag(CLASS)) {
1260 List<JCExpression> args = tree.arguments;
1261 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1262
1263 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1264 if (incompatibleArg != null) {
1265 for (JCTree arg : tree.arguments) {
1266 if (arg.type == incompatibleArg) {
1267 log.error(arg, "not.within.bounds", incompatibleArg, forms.head);
1268 }
1269 forms = forms.tail;
1270 }
1271 }
1272
1273 forms = tree.type.tsym.type.getTypeArguments();
1274
1275 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1276
1277 // For matching pairs of actual argument types `a' and
1278 // formal type parameters with declared bound `b' ...
1279 while (args.nonEmpty() && forms.nonEmpty()) {
1280 validateTree(args.head,
1281 !(isOuter && is_java_lang_Class),
1282 false);
1283 args = args.tail;
1284 forms = forms.tail;
1285 }
1286
1287 // Check that this type is either fully parameterized, or
1288 // not parameterized at all.
1289 if (tree.type.getEnclosingType().isRaw())
1290 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1291 if (tree.clazz.hasTag(SELECT))
1292 visitSelectInternal((JCFieldAccess)tree.clazz);
1293 }
1294 }
1295
1296 @Override
1297 public void visitTypeParameter(JCTypeParameter tree) {
1298 validateTrees(tree.bounds, true, isOuter);
1299 checkClassBounds(tree.pos(), tree.type);
1300 }
1301
1302 @Override
1303 public void visitWildcard(JCWildcard tree) {
1304 if (tree.inner != null)
1305 validateTree(tree.inner, true, isOuter);
1306 }
1307
1308 @Override
1309 public void visitSelect(JCFieldAccess tree) {
1310 if (tree.type.hasTag(CLASS)) {
1311 visitSelectInternal(tree);
1312
1313 // Check that this type is either fully parameterized, or
1314 // not parameterized at all.
1315 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1316 log.error(tree.pos(), "improperly.formed.type.param.missing");
1317 }
1318 }
1319
1320 public void visitSelectInternal(JCFieldAccess tree) {
1321 if (tree.type.tsym.isStatic() &&
1322 tree.selected.type.isParameterized()) {
1323 // The enclosing type is not a class, so we are
1324 // looking at a static member type. However, the
1325 // qualifying expression is parameterized.
1326 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1327 } else {
1328 // otherwise validate the rest of the expression
1329 tree.selected.accept(this);
1330 }
1331 }
1332
1333 @Override
1334 public void visitAnnotatedType(JCAnnotatedType tree) {
1335 tree.underlyingType.accept(this);
1336 }
1337
1338 @Override
1339 public void visitTypeIdent(JCPrimitiveTypeTree that) {
1340 if (that.type.hasTag(TypeTag.VOID)) {
1341 log.error(that.pos(), "void.not.allowed.here");
1342 }
1343 super.visitTypeIdent(that);
1344 }
1345
1346 /** Default visitor method: do nothing.
1347 */
1348 @Override
1349 public void visitTree(JCTree tree) {
1350 }
1351
1352 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1353 if (tree != null) {
1354 boolean prevCheckRaw = this.checkRaw;
1355 this.checkRaw = checkRaw;
1356 this.isOuter = isOuter;
1357
1358 try {
1359 tree.accept(this);
1360 if (checkRaw)
1361 checkRaw(tree, env);
1362 } catch (CompletionFailure ex) {
1363 completionError(tree.pos(), ex);
1364 } finally {
1365 this.checkRaw = prevCheckRaw;
1366 }
1367 }
1368 }
1369
1370 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1371 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1372 validateTree(l.head, checkRaw, isOuter);
1373 }
1374 }
1375
1376 void checkRaw(JCTree tree, Env<AttrContext> env) {
1377 if (lint.isEnabled(LintCategory.RAW) &&
1378 tree.type.hasTag(CLASS) &&
1379 !TreeInfo.isDiamond(tree) &&
1380 !withinAnonConstr(env) &&
1381 tree.type.isRaw()) {
1382 log.warning(LintCategory.RAW,
1383 tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
1384 }
1385 }
1386 //where
1387 private boolean withinAnonConstr(Env<AttrContext> env) {
1388 return env.enclClass.name.isEmpty() &&
1389 env.enclMethod != null && env.enclMethod.name == names.init;
1390 }
1391
1392 /* *************************************************************************
1393 * Exception checking
1394 **************************************************************************/
1395
1396 /* The following methods treat classes as sets that contain
1397 * the class itself and all their subclasses
1398 */
1399
1400 /** Is given type a subtype of some of the types in given list?
1401 */
1402 boolean subset(Type t, List<Type> ts) {
1403 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1404 if (types.isSubtype(t, l.head)) return true;
1405 return false;
1406 }
1407
1408 /** Is given type a subtype or supertype of
1409 * some of the types in given list?
1410 */
1411 boolean intersects(Type t, List<Type> ts) {
1412 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1413 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1414 return false;
1415 }
1416
1417 /** Add type set to given type list, unless it is a subclass of some class
1418 * in the list.
1419 */
1420 List<Type> incl(Type t, List<Type> ts) {
1421 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1422 }
1423
1424 /** Remove type set from type set list.
1425 */
1426 List<Type> excl(Type t, List<Type> ts) {
1427 if (ts.isEmpty()) {
1428 return ts;
1429 } else {
1430 List<Type> ts1 = excl(t, ts.tail);
1431 if (types.isSubtype(ts.head, t)) return ts1;
1432 else if (ts1 == ts.tail) return ts;
1433 else return ts1.prepend(ts.head);
1434 }
1435 }
1436
1437 /** Form the union of two type set lists.
1438 */
1439 List<Type> union(List<Type> ts1, List<Type> ts2) {
1440 List<Type> ts = ts1;
1441 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1442 ts = incl(l.head, ts);
1443 return ts;
1444 }
1445
1446 /** Form the difference of two type lists.
1447 */
1448 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1449 List<Type> ts = ts1;
1450 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1451 ts = excl(l.head, ts);
1452 return ts;
1453 }
1454
1455 /** Form the intersection of two type lists.
1456 */
1457 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1458 List<Type> ts = List.nil();
1459 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1460 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1461 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1462 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1463 return ts;
1464 }
1465
1466 /** Is exc an exception symbol that need not be declared?
1467 */
1468 boolean isUnchecked(ClassSymbol exc) {
1469 return
1470 exc.kind == ERR ||
1471 exc.isSubClass(syms.errorType.tsym, types) ||
1472 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1473 }
1474
1475 /** Is exc an exception type that need not be declared?
1476 */
1477 boolean isUnchecked(Type exc) {
1478 return
1479 (exc.hasTag(TYPEVAR)) ? isUnchecked(types.supertype(exc)) :
1480 (exc.hasTag(CLASS)) ? isUnchecked((ClassSymbol)exc.tsym) :
1481 exc.hasTag(BOT);
1482 }
1483
1484 /** Same, but handling completion failures.
1485 */
1486 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1487 try {
1488 return isUnchecked(exc);
1489 } catch (CompletionFailure ex) {
1490 completionError(pos, ex);
1491 return true;
1492 }
1493 }
1494
1495 /** Is exc handled by given exception list?
1496 */
1497 boolean isHandled(Type exc, List<Type> handled) {
1498 return isUnchecked(exc) || subset(exc, handled);
1499 }
1500
1501 /** Return all exceptions in thrown list that are not in handled list.
1502 * @param thrown The list of thrown exceptions.
1503 * @param handled The list of handled exceptions.
1504 */
1505 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1506 List<Type> unhandled = List.nil();
1507 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1508 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1509 return unhandled;
1510 }
1511
1512 /* *************************************************************************
1513 * Overriding/Implementation checking
1514 **************************************************************************/
1515
1516 /** The level of access protection given by a flag set,
1517 * where PRIVATE is highest and PUBLIC is lowest.
1518 */
1519 static int protection(long flags) {
1520 switch ((short)(flags & AccessFlags)) {
1521 case PRIVATE: return 3;
1522 case PROTECTED: return 1;
1523 default:
1524 case PUBLIC: return 0;
1525 case 0: return 2;
1526 }
1527 }
1528
1529 /** A customized "cannot override" error message.
1530 * @param m The overriding method.
1531 * @param other The overridden method.
1532 * @return An internationalized string.
1533 */
1534 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1535 String key;
1536 if ((other.owner.flags() & INTERFACE) == 0)
1537 key = "cant.override";
1538 else if ((m.owner.flags() & INTERFACE) == 0)
1539 key = "cant.implement";
1540 else
1541 key = "clashes.with";
1542 return diags.fragment(key, m, m.location(), other, other.location());
1543 }
1544
1545 /** A customized "override" warning message.
1546 * @param m The overriding method.
1547 * @param other The overridden method.
1548 * @return An internationalized string.
1549 */
1550 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1551 String key;
1552 if ((other.owner.flags() & INTERFACE) == 0)
1553 key = "unchecked.override";
1554 else if ((m.owner.flags() & INTERFACE) == 0)
1555 key = "unchecked.implement";
1556 else
1557 key = "unchecked.clash.with";
1558 return diags.fragment(key, m, m.location(), other, other.location());
1559 }
1560
1561 /** A customized "override" warning message.
1562 * @param m The overriding method.
1563 * @param other The overridden method.
1564 * @return An internationalized string.
1565 */
1566 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1567 String key;
1568 if ((other.owner.flags() & INTERFACE) == 0)
1569 key = "varargs.override";
1570 else if ((m.owner.flags() & INTERFACE) == 0)
1571 key = "varargs.implement";
1572 else
1573 key = "varargs.clash.with";
1574 return diags.fragment(key, m, m.location(), other, other.location());
1575 }
1576
1577 /** Check that this method conforms with overridden method 'other'.
1578 * where `origin' is the class where checking started.
1579 * Complications:
1580 * (1) Do not check overriding of synthetic methods
1581 * (reason: they might be final).
1582 * todo: check whether this is still necessary.
1583 * (2) Admit the case where an interface proxy throws fewer exceptions
1584 * than the method it implements. Augment the proxy methods with the
1585 * undeclared exceptions in this case.
1586 * (3) When generics are enabled, admit the case where an interface proxy
1587 * has a result type
1588 * extended by the result type of the method it implements.
1589 * Change the proxies result type to the smaller type in this case.
1590 *
1591 * @param tree The tree from which positions
1592 * are extracted for errors.
1593 * @param m The overriding method.
1594 * @param other The overridden method.
1595 * @param origin The class of which the overriding method
1596 * is a member.
1597 */
1598 void checkOverride(JCTree tree,
1599 MethodSymbol m,
1600 MethodSymbol other,
1601 ClassSymbol origin) {
1602 // Don't check overriding of synthetic methods or by bridge methods.
1603 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1604 return;
1605 }
1606
1607 // Error if static method overrides instance method (JLS 8.4.6.2).
1608 if ((m.flags() & STATIC) != 0 &&
1609 (other.flags() & STATIC) == 0) {
1610 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1611 cannotOverride(m, other));
1612 m.flags_field |= BAD_OVERRIDE;
1613 return;
1614 }
1615
1616 // Error if instance method overrides static or final
1617 // method (JLS 8.4.6.1).
1618 if ((other.flags() & FINAL) != 0 ||
1619 (m.flags() & STATIC) == 0 &&
1620 (other.flags() & STATIC) != 0) {
1621 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1622 cannotOverride(m, other),
1623 asFlagSet(other.flags() & (FINAL | STATIC)));
1624 m.flags_field |= BAD_OVERRIDE;
1625 return;
1626 }
1627
1628 if ((m.owner.flags() & ANNOTATION) != 0) {
1629 // handled in validateAnnotationMethod
1630 return;
1631 }
1632
1633 // Error if overriding method has weaker access (JLS 8.4.6.3).
1634 if ((origin.flags() & INTERFACE) == 0 &&
1635 protection(m.flags()) > protection(other.flags())) {
1636 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1637 cannotOverride(m, other),
1638 (other.flags() & AccessFlags) == 0 ?
1639 "package" :
1640 asFlagSet(other.flags() & AccessFlags));
1641 m.flags_field |= BAD_OVERRIDE;
1642 return;
1643 }
1644
1645 Type mt = types.memberType(origin.type, m);
1646 Type ot = types.memberType(origin.type, other);
1647 // Error if overriding result type is different
1648 // (or, in the case of generics mode, not a subtype) of
1649 // overridden result type. We have to rename any type parameters
1650 // before comparing types.
1651 List<Type> mtvars = mt.getTypeArguments();
1652 List<Type> otvars = ot.getTypeArguments();
1653 Type mtres = mt.getReturnType();
1654 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1655
1656 overrideWarner.clear();
1657 boolean resultTypesOK =
1658 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1659 if (!resultTypesOK) {
1660 if (!allowCovariantReturns &&
1661 m.owner != origin &&
1662 m.owner.isSubClass(other.owner, types)) {
1663 // allow limited interoperability with covariant returns
1664 } else {
1665 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1666 "override.incompatible.ret",
1667 cannotOverride(m, other),
1668 mtres, otres);
1669 m.flags_field |= BAD_OVERRIDE;
1670 return;
1671 }
1672 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1673 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1674 "override.unchecked.ret",
1675 uncheckedOverrides(m, other),
1676 mtres, otres);
1677 }
1678
1679 // Error if overriding method throws an exception not reported
1680 // by overridden method.
1681 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1682 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1683 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1684 if (unhandledErased.nonEmpty()) {
1685 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1686 "override.meth.doesnt.throw",
1687 cannotOverride(m, other),
1688 unhandledUnerased.head);
1689 m.flags_field |= BAD_OVERRIDE;
1690 return;
1691 }
1692 else if (unhandledUnerased.nonEmpty()) {
1693 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1694 "override.unchecked.thrown",
1695 cannotOverride(m, other),
1696 unhandledUnerased.head);
1697 return;
1698 }
1699
1700 // Optional warning if varargs don't agree
1701 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1702 && lint.isEnabled(LintCategory.OVERRIDES)) {
1703 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1704 ((m.flags() & Flags.VARARGS) != 0)
1705 ? "override.varargs.missing"
1706 : "override.varargs.extra",
1707 varargsOverrides(m, other));
1708 }
1709
1710 // Warn if instance method overrides bridge method (compiler spec ??)
1711 if ((other.flags() & BRIDGE) != 0) {
1712 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1713 uncheckedOverrides(m, other));
1714 }
1715
1716 // Warn if a deprecated method overridden by a non-deprecated one.
1717 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1718 Lint prevLint = setLint(lint.augment(m));
1719 try {
1720 checkDeprecated(TreeInfo.diagnosticPositionFor(m, tree), m, other);
1721 } finally {
1722 setLint(prevLint);
1723 }
1724 }
1725 }
1726 // where
1727 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1728 // If the method, m, is defined in an interface, then ignore the issue if the method
1729 // is only inherited via a supertype and also implemented in the supertype,
1730 // because in that case, we will rediscover the issue when examining the method
1731 // in the supertype.
1732 // If the method, m, is not defined in an interface, then the only time we need to
1733 // address the issue is when the method is the supertype implemementation: any other
1734 // case, we will have dealt with when examining the supertype classes
1735 ClassSymbol mc = m.enclClass();
1736 Type st = types.supertype(origin.type);
1737 if (!st.hasTag(CLASS))
1738 return true;
1739 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1740
1741 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1742 List<Type> intfs = types.interfaces(origin.type);
1743 return (intfs.contains(mc.type) ? false : (stimpl != null));
1744 }
1745 else
1746 return (stimpl != m);
1747 }
1748
1749
1750 // used to check if there were any unchecked conversions
1751 Warner overrideWarner = new Warner();
1752
1753 /** Check that a class does not inherit two concrete methods
1754 * with the same signature.
1755 * @param pos Position to be used for error reporting.
1756 * @param site The class type to be checked.
1757 */
1758 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1759 Type sup = types.supertype(site);
1760 if (!sup.hasTag(CLASS)) return;
1761
1762 for (Type t1 = sup;
1763 t1.hasTag(CLASS) && t1.tsym.type.isParameterized();
1764 t1 = types.supertype(t1)) {
1765 for (Scope.Entry e1 = t1.tsym.members().elems;
1766 e1 != null;
1767 e1 = e1.sibling) {
1768 Symbol s1 = e1.sym;
1769 if (s1.kind != MTH ||
1770 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1771 !s1.isInheritedIn(site.tsym, types) ||
1772 ((MethodSymbol)s1).implementation(site.tsym,
1773 types,
1774 true) != s1)
1775 continue;
1776 Type st1 = types.memberType(t1, s1);
1777 int s1ArgsLength = st1.getParameterTypes().length();
1778 if (st1 == s1.type) continue;
1779
1780 for (Type t2 = sup;
1781 t2.hasTag(CLASS);
1782 t2 = types.supertype(t2)) {
1783 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1784 e2.scope != null;
1785 e2 = e2.next()) {
1786 Symbol s2 = e2.sym;
1787 if (s2 == s1 ||
1788 s2.kind != MTH ||
1789 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1790 s2.type.getParameterTypes().length() != s1ArgsLength ||
1791 !s2.isInheritedIn(site.tsym, types) ||
1792 ((MethodSymbol)s2).implementation(site.tsym,
1793 types,
1794 true) != s2)
1795 continue;
1796 Type st2 = types.memberType(t2, s2);
1797 if (types.overrideEquivalent(st1, st2))
1798 log.error(pos, "concrete.inheritance.conflict",
1799 s1, t1, s2, t2, sup);
1800 }
1801 }
1802 }
1803 }
1804 }
1805
1806 /** Check that classes (or interfaces) do not each define an abstract
1807 * method with same name and arguments but incompatible return types.
1808 * @param pos Position to be used for error reporting.
1809 * @param t1 The first argument type.
1810 * @param t2 The second argument type.
1811 */
1812 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1813 Type t1,
1814 Type t2) {
1815 return checkCompatibleAbstracts(pos, t1, t2,
1816 types.makeCompoundType(t1, t2));
1817 }
1818
1819 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1820 Type t1,
1821 Type t2,
1822 Type site) {
1823 if ((site.tsym.flags() & COMPOUND) != 0) {
1824 // special case for intersections: need to eliminate wildcards in supertypes
1825 t1 = types.capture(t1);
1826 t2 = types.capture(t2);
1827 }
1828 return firstIncompatibility(pos, t1, t2, site) == null;
1829 }
1830
1831 /** Return the first method which is defined with same args
1832 * but different return types in two given interfaces, or null if none
1833 * exists.
1834 * @param t1 The first type.
1835 * @param t2 The second type.
1836 * @param site The most derived type.
1837 * @returns symbol from t2 that conflicts with one in t1.
1838 */
1839 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1840 Map<TypeSymbol,Type> interfaces1 = new HashMap<>();
1841 closure(t1, interfaces1);
1842 Map<TypeSymbol,Type> interfaces2;
1843 if (t1 == t2)
1844 interfaces2 = interfaces1;
1845 else
1846 closure(t2, interfaces1, interfaces2 = new HashMap<>());
1847
1848 for (Type t3 : interfaces1.values()) {
1849 for (Type t4 : interfaces2.values()) {
1850 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
1851 if (s != null) return s;
1852 }
1853 }
1854 return null;
1855 }
1856
1857 /** Compute all the supertypes of t, indexed by type symbol. */
1858 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1859 if (!t.hasTag(CLASS)) return;
1860 if (typeMap.put(t.tsym, t) == null) {
1861 closure(types.supertype(t), typeMap);
1862 for (Type i : types.interfaces(t))
1863 closure(i, typeMap);
1864 }
1865 }
1866
1867 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1868 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1869 if (!t.hasTag(CLASS)) return;
1870 if (typesSkip.get(t.tsym) != null) return;
1871 if (typeMap.put(t.tsym, t) == null) {
1872 closure(types.supertype(t), typesSkip, typeMap);
1873 for (Type i : types.interfaces(t))
1874 closure(i, typesSkip, typeMap);
1875 }
1876 }
1877
1878 /** Return the first method in t2 that conflicts with a method from t1. */
1879 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1880 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1881 Symbol s1 = e1.sym;
1882 Type st1 = null;
1883 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types) ||
1884 (s1.flags() & SYNTHETIC) != 0) continue;
1885 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1886 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1887 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1888 Symbol s2 = e2.sym;
1889 if (s1 == s2) continue;
1890 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types) ||
1891 (s2.flags() & SYNTHETIC) != 0) continue;
1892 if (st1 == null) st1 = types.memberType(t1, s1);
1893 Type st2 = types.memberType(t2, s2);
1894 if (types.overrideEquivalent(st1, st2)) {
1895 List<Type> tvars1 = st1.getTypeArguments();
1896 List<Type> tvars2 = st2.getTypeArguments();
1897 Type rt1 = st1.getReturnType();
1898 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1899 boolean compat =
1900 types.isSameType(rt1, rt2) ||
1901 !rt1.isPrimitiveOrVoid() &&
1902 !rt2.isPrimitiveOrVoid() &&
1903 (types.covariantReturnType(rt1, rt2, types.noWarnings) ||
1904 types.covariantReturnType(rt2, rt1, types.noWarnings)) ||
1905 checkCommonOverriderIn(s1,s2,site);
1906 if (!compat) {
1907 log.error(pos, "types.incompatible.diff.ret",
1908 t1, t2, s2.name +
1909 "(" + types.memberType(t2, s2).getParameterTypes() + ")");
1910 return s2;
1911 }
1912 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) &&
1913 !checkCommonOverriderIn(s1, s2, site)) {
1914 log.error(pos,
1915 "name.clash.same.erasure.no.override",
1916 s1, s1.location(),
1917 s2, s2.location());
1918 return s2;
1919 }
1920 }
1921 }
1922 return null;
1923 }
1924 //WHERE
1925 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1926 Map<TypeSymbol,Type> supertypes = new HashMap<>();
1927 Type st1 = types.memberType(site, s1);
1928 Type st2 = types.memberType(site, s2);
1929 closure(site, supertypes);
1930 for (Type t : supertypes.values()) {
1931 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1932 Symbol s3 = e.sym;
1933 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1934 Type st3 = types.memberType(site,s3);
1935 if (types.overrideEquivalent(st3, st1) &&
1936 types.overrideEquivalent(st3, st2) &&
1937 types.returnTypeSubstitutable(st3, st1) &&
1938 types.returnTypeSubstitutable(st3, st2)) {
1939 return true;
1940 }
1941 }
1942 }
1943 return false;
1944 }
1945
1946 /** Check that a given method conforms with any method it overrides.
1947 * @param tree The tree from which positions are extracted
1948 * for errors.
1949 * @param m The overriding method.
1950 */
1951 void checkOverride(JCMethodDecl tree, MethodSymbol m) {
1952 ClassSymbol origin = (ClassSymbol)m.owner;
1953 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1954 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1955 log.error(tree.pos(), "enum.no.finalize");
1956 return;
1957 }
1958 for (Type t = origin.type; t.hasTag(CLASS);
1959 t = types.supertype(t)) {
1960 if (t != origin.type) {
1961 checkOverride(tree, t, origin, m);
1962 }
1963 for (Type t2 : types.interfaces(t)) {
1964 checkOverride(tree, t2, origin, m);
1965 }
1966 }
1967
1968 if (m.attribute(syms.overrideType.tsym) != null && !isOverrider(m)) {
1969 DiagnosticPosition pos = tree.pos();
1970 for (JCAnnotation a : tree.getModifiers().annotations) {
1971 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
1972 pos = a.pos();
1973 break;
1974 }
1975 }
1976 log.error(pos, "method.does.not.override.superclass");
1977 }
1978 }
1979
1980 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
1981 TypeSymbol c = site.tsym;
1982 Scope.Entry e = c.members().lookup(m.name);
1983 while (e.scope != null) {
1984 if (m.overrides(e.sym, origin, types, false)) {
1985 if ((e.sym.flags() & ABSTRACT) == 0) {
1986 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1987 }
1988 }
1989 e = e.next();
1990 }
1991 }
1992
1993 private Filter<Symbol> equalsHasCodeFilter = new Filter<Symbol>() {
1994 public boolean accepts(Symbol s) {
1995 return MethodSymbol.implementation_filter.accepts(s) &&
1996 (s.flags() & BAD_OVERRIDE) == 0;
1997
1998 }
1999 };
2000
2001 public void checkClassOverrideEqualsAndHashIfNeeded(DiagnosticPosition pos,
2002 ClassSymbol someClass) {
2003 /* At present, annotations cannot possibly have a method that is override
2004 * equivalent with Object.equals(Object) but in any case the condition is
2005 * fine for completeness.
2006 */
2007 if (someClass == (ClassSymbol)syms.objectType.tsym ||
2008 someClass.isInterface() || someClass.isEnum() ||
2009 (someClass.flags() & ANNOTATION) != 0 ||
2010 (someClass.flags() & ABSTRACT) != 0) return;
2011 //anonymous inner classes implementing interfaces need especial treatment
2012 if (someClass.isAnonymous()) {
2013 List<Type> interfaces = types.interfaces(someClass.type);
2014 if (interfaces != null && !interfaces.isEmpty() &&
2015 interfaces.head.tsym == syms.comparatorType.tsym) return;
2016 }
2017 checkClassOverrideEqualsAndHash(pos, someClass);
2018 }
2019
2020 private void checkClassOverrideEqualsAndHash(DiagnosticPosition pos,
2021 ClassSymbol someClass) {
2022 if (lint.isEnabled(LintCategory.OVERRIDES)) {
2023 MethodSymbol equalsAtObject = (MethodSymbol)syms.objectType
2024 .tsym.members().lookup(names.equals).sym;
2025 MethodSymbol hashCodeAtObject = (MethodSymbol)syms.objectType
2026 .tsym.members().lookup(names.hashCode).sym;
2027 boolean overridesEquals = types.implementation(equalsAtObject,
2028 someClass, false, equalsHasCodeFilter).owner == someClass;
2029 boolean overridesHashCode = types.implementation(hashCodeAtObject,
2030 someClass, false, equalsHasCodeFilter) != hashCodeAtObject;
2031
2032 if (overridesEquals && !overridesHashCode) {
2033 log.warning(LintCategory.OVERRIDES, pos,
2034 "override.equals.but.not.hashcode", someClass);
2035 }
2036 }
2037 }
2038
2039 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
2040 ClashFilter cf = new ClashFilter(origin.type);
2041 return (cf.accepts(s1) &&
2042 cf.accepts(s2) &&
2043 types.hasSameArgs(s1.erasure(types), s2.erasure(types)));
2044 }
2045
2046
2047 /** Check that all abstract members of given class have definitions.
2048 * @param pos Position to be used for error reporting.
2049 * @param c The class.
2050 */
2051 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
2052 try {
2053 MethodSymbol undef = firstUndef(c, c);
2054 if (undef != null) {
2055 if ((c.flags() & ENUM) != 0 &&
2056 types.supertype(c.type).tsym == syms.enumSym &&
2057 (c.flags() & FINAL) == 0) {
2058 // add the ABSTRACT flag to an enum
2059 c.flags_field |= ABSTRACT;
2060 } else {
2061 MethodSymbol undef1 =
2062 new MethodSymbol(undef.flags(), undef.name,
2063 types.memberType(c.type, undef), undef.owner);
2064 log.error(pos, "does.not.override.abstract",
2065 c, undef1, undef1.location());
2066 }
2067 }
2068 } catch (CompletionFailure ex) {
2069 completionError(pos, ex);
2070 }
2071 }
2072 //where
2073 /** Return first abstract member of class `c' that is not defined
2074 * in `impl', null if there is none.
2075 */
2076 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
2077 MethodSymbol undef = null;
2078 // Do not bother to search in classes that are not abstract,
2079 // since they cannot have abstract members.
2080 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
2081 Scope s = c.members();
2082 for (Scope.Entry e = s.elems;
2083 undef == null && e != null;
2084 e = e.sibling) {
2085 if (e.sym.kind == MTH &&
2086 (e.sym.flags() & (ABSTRACT|IPROXY|DEFAULT)) == ABSTRACT) {
2087 MethodSymbol absmeth = (MethodSymbol)e.sym;
2088 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
2089 if (implmeth == null || implmeth == absmeth) {
2090 //look for default implementations
2091 if (allowDefaultMethods) {
2092 MethodSymbol prov = types.interfaceCandidates(impl.type, absmeth).head;
2093 if (prov != null && prov.overrides(absmeth, impl, types, true)) {
2094 implmeth = prov;
2095 }
2096 }
2097 }
2098 if (implmeth == null || implmeth == absmeth) {
2099 undef = absmeth;
2100 }
2101 }
2102 }
2103 if (undef == null) {
2104 Type st = types.supertype(c.type);
2105 if (st.hasTag(CLASS))
2106 undef = firstUndef(impl, (ClassSymbol)st.tsym);
2107 }
2108 for (List<Type> l = types.interfaces(c.type);
2109 undef == null && l.nonEmpty();
2110 l = l.tail) {
2111 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
2112 }
2113 }
2114 return undef;
2115 }
2116
2117 void checkNonCyclicDecl(JCClassDecl tree) {
2118 CycleChecker cc = new CycleChecker();
2119 cc.scan(tree);
2120 if (!cc.errorFound && !cc.partialCheck) {
2121 tree.sym.flags_field |= ACYCLIC;
2122 }
2123 }
2124
2125 class CycleChecker extends TreeScanner {
2126
2127 List<Symbol> seenClasses = List.nil();
2128 boolean errorFound = false;
2129 boolean partialCheck = false;
2130
2131 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
2132 if (sym != null && sym.kind == TYP) {
2133 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
2134 if (classEnv != null) {
2135 DiagnosticSource prevSource = log.currentSource();
2136 try {
2137 log.useSource(classEnv.toplevel.sourcefile);
2138 scan(classEnv.tree);
2139 }
2140 finally {
2141 log.useSource(prevSource.getFile());
2142 }
2143 } else if (sym.kind == TYP) {
2144 checkClass(pos, sym, List.<JCTree>nil());
2145 }
2146 } else {
2147 //not completed yet
2148 partialCheck = true;
2149 }
2150 }
2151
2152 @Override
2153 public void visitSelect(JCFieldAccess tree) {
2154 super.visitSelect(tree);
2155 checkSymbol(tree.pos(), tree.sym);
2156 }
2157
2158 @Override
2159 public void visitIdent(JCIdent tree) {
2160 checkSymbol(tree.pos(), tree.sym);
2161 }
2162
2163 @Override
2164 public void visitTypeApply(JCTypeApply tree) {
2165 scan(tree.clazz);
2166 }
2167
2168 @Override
2169 public void visitTypeArray(JCArrayTypeTree tree) {
2170 scan(tree.elemtype);
2171 }
2172
2173 @Override
2174 public void visitClassDef(JCClassDecl tree) {
2175 List<JCTree> supertypes = List.nil();
2176 if (tree.getExtendsClause() != null) {
2177 supertypes = supertypes.prepend(tree.getExtendsClause());
2178 }
2179 if (tree.getImplementsClause() != null) {
2180 for (JCTree intf : tree.getImplementsClause()) {
2181 supertypes = supertypes.prepend(intf);
2182 }
2183 }
2184 checkClass(tree.pos(), tree.sym, supertypes);
2185 }
2186
2187 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
2188 if ((c.flags_field & ACYCLIC) != 0)
2189 return;
2190 if (seenClasses.contains(c)) {
2191 errorFound = true;
2192 noteCyclic(pos, (ClassSymbol)c);
2193 } else if (!c.type.isErroneous()) {
2194 try {
2195 seenClasses = seenClasses.prepend(c);
2196 if (c.type.hasTag(CLASS)) {
2197 if (supertypes.nonEmpty()) {
2198 scan(supertypes);
2199 }
2200 else {
2201 ClassType ct = (ClassType)c.type;
2202 if (ct.supertype_field == null ||
2203 ct.interfaces_field == null) {
2204 //not completed yet
2205 partialCheck = true;
2206 return;
2207 }
2208 checkSymbol(pos, ct.supertype_field.tsym);
2209 for (Type intf : ct.interfaces_field) {
2210 checkSymbol(pos, intf.tsym);
2211 }
2212 }
2213 if (c.owner.kind == TYP) {
2214 checkSymbol(pos, c.owner);
2215 }
2216 }
2217 } finally {
2218 seenClasses = seenClasses.tail;
2219 }
2220 }
2221 }
2222 }
2223
2224 /** Check for cyclic references. Issue an error if the
2225 * symbol of the type referred to has a LOCKED flag set.
2226 *
2227 * @param pos Position to be used for error reporting.
2228 * @param t The type referred to.
2229 */
2230 void checkNonCyclic(DiagnosticPosition pos, Type t) {
2231 checkNonCyclicInternal(pos, t);
2232 }
2233
2234
2235 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
2236 checkNonCyclic1(pos, t, List.<TypeVar>nil());
2237 }
2238
2239 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
2240 final TypeVar tv;
2241 if (t.hasTag(TYPEVAR) && (t.tsym.flags() & UNATTRIBUTED) != 0)
2242 return;
2243 if (seen.contains(t)) {
2244 tv = (TypeVar)t;
2245 tv.bound = types.createErrorType(t);
2246 log.error(pos, "cyclic.inheritance", t);
2247 } else if (t.hasTag(TYPEVAR)) {
2248 tv = (TypeVar)t;
2249 seen = seen.prepend(tv);
2250 for (Type b : types.getBounds(tv))
2251 checkNonCyclic1(pos, b, seen);
2252 }
2253 }
2254
2255 /** Check for cyclic references. Issue an error if the
2256 * symbol of the type referred to has a LOCKED flag set.
2257 *
2258 * @param pos Position to be used for error reporting.
2259 * @param t The type referred to.
2260 * @returns True if the check completed on all attributed classes
2261 */
2262 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
2263 boolean complete = true; // was the check complete?
2264 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
2265 Symbol c = t.tsym;
2266 if ((c.flags_field & ACYCLIC) != 0) return true;
2267
2268 if ((c.flags_field & LOCKED) != 0) {
2269 noteCyclic(pos, (ClassSymbol)c);
2270 } else if (!c.type.isErroneous()) {
2271 try {
2272 c.flags_field |= LOCKED;
2273 if (c.type.hasTag(CLASS)) {
2274 ClassType clazz = (ClassType)c.type;
2275 if (clazz.interfaces_field != null)
2276 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
2277 complete &= checkNonCyclicInternal(pos, l.head);
2278 if (clazz.supertype_field != null) {
2279 Type st = clazz.supertype_field;
2280 if (st != null && st.hasTag(CLASS))
2281 complete &= checkNonCyclicInternal(pos, st);
2282 }
2283 if (c.owner.kind == TYP)
2284 complete &= checkNonCyclicInternal(pos, c.owner.type);
2285 }
2286 } finally {
2287 c.flags_field &= ~LOCKED;
2288 }
2289 }
2290 if (complete)
2291 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
2292 if (complete) c.flags_field |= ACYCLIC;
2293 return complete;
2294 }
2295
2296 /** Note that we found an inheritance cycle. */
2297 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
2298 log.error(pos, "cyclic.inheritance", c);
2299 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
2300 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
2301 Type st = types.supertype(c.type);
2302 if (st.hasTag(CLASS))
2303 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2304 c.type = types.createErrorType(c, c.type);
2305 c.flags_field |= ACYCLIC;
2306 }
2307
2308 /** Check that all methods which implement some
2309 * method conform to the method they implement.
2310 * @param tree The class definition whose members are checked.
2311 */
2312 void checkImplementations(JCClassDecl tree) {
2313 checkImplementations(tree, tree.sym, tree.sym);
2314 }
2315 //where
2316 /** Check that all methods which implement some
2317 * method in `ic' conform to the method they implement.
2318 */
2319 void checkImplementations(JCTree tree, ClassSymbol origin, ClassSymbol ic) {
2320 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2321 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2322 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
2323 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
2324 if (e.sym.kind == MTH &&
2325 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2326 MethodSymbol absmeth = (MethodSymbol)e.sym;
2327 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2328 if (implmeth != null && implmeth != absmeth &&
2329 (implmeth.owner.flags() & INTERFACE) ==
2330 (origin.flags() & INTERFACE)) {
2331 // don't check if implmeth is in a class, yet
2332 // origin is an interface. This case arises only
2333 // if implmeth is declared in Object. The reason is
2334 // that interfaces really don't inherit from
2335 // Object it's just that the compiler represents
2336 // things that way.
2337 checkOverride(tree, implmeth, absmeth, origin);
2338 }
2339 }
2340 }
2341 }
2342 }
2343 }
2344
2345 /** Check that all abstract methods implemented by a class are
2346 * mutually compatible.
2347 * @param pos Position to be used for error reporting.
2348 * @param c The class whose interfaces are checked.
2349 */
2350 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2351 List<Type> supertypes = types.interfaces(c);
2352 Type supertype = types.supertype(c);
2353 if (supertype.hasTag(CLASS) &&
2354 (supertype.tsym.flags() & ABSTRACT) != 0)
2355 supertypes = supertypes.prepend(supertype);
2356 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2357 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
2358 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2359 return;
2360 for (List<Type> m = supertypes; m != l; m = m.tail)
2361 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2362 return;
2363 }
2364 checkCompatibleConcretes(pos, c);
2365 }
2366
2367 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
2368 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
2369 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
2370 // VM allows methods and variables with differing types
2371 if (sym.kind == e.sym.kind &&
2372 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
2373 sym != e.sym &&
2374 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
2375 (sym.flags() & IPROXY) == 0 && (e.sym.flags() & IPROXY) == 0 &&
2376 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
2377 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
2378 return;
2379 }
2380 }
2381 }
2382 }
2383
2384 /** Check that all non-override equivalent methods accessible from 'site'
2385 * are mutually compatible (JLS 8.4.8/9.4.1).
2386 *
2387 * @param pos Position to be used for error reporting.
2388 * @param site The class whose methods are checked.
2389 * @param sym The method symbol to be checked.
2390 */
2391 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2392 ClashFilter cf = new ClashFilter(site);
2393 //for each method m1 that is overridden (directly or indirectly)
2394 //by method 'sym' in 'site'...
2395
2396 List<MethodSymbol> potentiallyAmbiguousList = List.nil();
2397 boolean overridesAny = false;
2398 for (Symbol m1 : types.membersClosure(site, false).getElementsByName(sym.name, cf)) {
2399 if (!sym.overrides(m1, site.tsym, types, false)) {
2400 if (m1 == sym) {
2401 continue;
2402 }
2403
2404 if (!overridesAny) {
2405 potentiallyAmbiguousList = potentiallyAmbiguousList.prepend((MethodSymbol)m1);
2406 }
2407 continue;
2408 }
2409
2410 if (m1 != sym) {
2411 overridesAny = true;
2412 potentiallyAmbiguousList = List.nil();
2413 }
2414
2415 //...check each method m2 that is a member of 'site'
2416 for (Symbol m2 : types.membersClosure(site, false).getElementsByName(sym.name, cf)) {
2417 if (m2 == m1) continue;
2418 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2419 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error
2420 if (!types.isSubSignature(sym.type, types.memberType(site, m2), allowStrictMethodClashCheck) &&
2421 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) {
2422 sym.flags_field |= CLASH;
2423 String key = m1 == sym ?
2424 "name.clash.same.erasure.no.override" :
2425 "name.clash.same.erasure.no.override.1";
2426 log.error(pos,
2427 key,
2428 sym, sym.location(),
2429 m2, m2.location(),
2430 m1, m1.location());
2431 return;
2432 }
2433 }
2434 }
2435
2436 if (!overridesAny) {
2437 for (MethodSymbol m: potentiallyAmbiguousList) {
2438 checkPotentiallyAmbiguousOverloads(pos, site, sym, m);
2439 }
2440 }
2441 }
2442
2443 /** Check that all static methods accessible from 'site' are
2444 * mutually compatible (JLS 8.4.8).
2445 *
2446 * @param pos Position to be used for error reporting.
2447 * @param site The class whose methods are checked.
2448 * @param sym The method symbol to be checked.
2449 */
2450 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) {
2451 ClashFilter cf = new ClashFilter(site);
2452 //for each method m1 that is a member of 'site'...
2453 for (Symbol s : types.membersClosure(site, true).getElementsByName(sym.name, cf)) {
2454 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as
2455 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error
2456 if (!types.isSubSignature(sym.type, types.memberType(site, s), allowStrictMethodClashCheck)) {
2457 if (types.hasSameArgs(s.erasure(types), sym.erasure(types))) {
2458 log.error(pos,
2459 "name.clash.same.erasure.no.hide",
2460 sym, sym.location(),
2461 s, s.location());
2462 return;
2463 } else {
2464 checkPotentiallyAmbiguousOverloads(pos, site, sym, (MethodSymbol)s);
2465 }
2466 }
2467 }
2468 }
2469
2470 //where
2471 private class ClashFilter implements Filter<Symbol> {
2472
2473 Type site;
2474
2475 ClashFilter(Type site) {
2476 this.site = site;
2477 }
2478
2479 boolean shouldSkip(Symbol s) {
2480 return (s.flags() & CLASH) != 0 &&
2481 s.owner == site.tsym;
2482 }
2483
2484 public boolean accepts(Symbol s) {
2485 return s.kind == MTH &&
2486 (s.flags() & SYNTHETIC) == 0 &&
2487 !shouldSkip(s) &&
2488 s.isInheritedIn(site.tsym, types) &&
2489 !s.isConstructor();
2490 }
2491 }
2492
2493 void checkDefaultMethodClashes(DiagnosticPosition pos, Type site) {
2494 DefaultMethodClashFilter dcf = new DefaultMethodClashFilter(site);
2495 for (Symbol m : types.membersClosure(site, false).getElements(dcf)) {
2496 Assert.check(m.kind == MTH);
2497 List<MethodSymbol> prov = types.interfaceCandidates(site, (MethodSymbol)m);
2498 if (prov.size() > 1) {
2499 ListBuffer<Symbol> abstracts = new ListBuffer<>();
2500 ListBuffer<Symbol> defaults = new ListBuffer<>();
2501 for (MethodSymbol provSym : prov) {
2502 if ((provSym.flags() & DEFAULT) != 0) {
2503 defaults = defaults.append(provSym);
2504 } else if ((provSym.flags() & ABSTRACT) != 0) {
2505 abstracts = abstracts.append(provSym);
2506 }
2507 if (defaults.nonEmpty() && defaults.size() + abstracts.size() >= 2) {
2508 //strong semantics - issue an error if two sibling interfaces
2509 //have two override-equivalent defaults - or if one is abstract
2510 //and the other is default
2511 String errKey;
2512 Symbol s1 = defaults.first();
2513 Symbol s2;
2514 if (defaults.size() > 1) {
2515 errKey = "types.incompatible.unrelated.defaults";
2516 s2 = defaults.toList().tail.head;
2517 } else {
2518 errKey = "types.incompatible.abstract.default";
2519 s2 = abstracts.first();
2520 }
2521 log.error(pos, errKey,
2522 Kinds.kindName(site.tsym), site,
2523 m.name, types.memberType(site, m).getParameterTypes(),
2524 s1.location(), s2.location());
2525 break;
2526 }
2527 }
2528 }
2529 }
2530 }
2531
2532 //where
2533 private class DefaultMethodClashFilter implements Filter<Symbol> {
2534
2535 Type site;
2536
2537 DefaultMethodClashFilter(Type site) {
2538 this.site = site;
2539 }
2540
2541 public boolean accepts(Symbol s) {
2542 return s.kind == MTH &&
2543 (s.flags() & DEFAULT) != 0 &&
2544 s.isInheritedIn(site.tsym, types) &&
2545 !s.isConstructor();
2546 }
2547 }
2548
2549 /**
2550 * Report warnings for potentially ambiguous method declarations. Two declarations
2551 * are potentially ambiguous if they feature two unrelated functional interface
2552 * in same argument position (in which case, a call site passing an implicit
2553 * lambda would be ambiguous).
2554 */
2555 void checkPotentiallyAmbiguousOverloads(DiagnosticPosition pos, Type site,
2556 MethodSymbol msym1, MethodSymbol msym2) {
2557 if (msym1 != msym2 &&
2558 allowDefaultMethods &&
2559 lint.isEnabled(LintCategory.OVERLOADS) &&
2560 (msym1.flags() & POTENTIALLY_AMBIGUOUS) == 0 &&
2561 (msym2.flags() & POTENTIALLY_AMBIGUOUS) == 0) {
2562 Type mt1 = types.memberType(site, msym1);
2563 Type mt2 = types.memberType(site, msym2);
2564 //if both generic methods, adjust type variables
2565 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL) &&
2566 types.hasSameBounds((ForAll)mt1, (ForAll)mt2)) {
2567 mt2 = types.subst(mt2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
2568 }
2569 //expand varargs methods if needed
2570 int maxLength = Math.max(mt1.getParameterTypes().length(), mt2.getParameterTypes().length());
2571 List<Type> args1 = rs.adjustArgs(mt1.getParameterTypes(), msym1, maxLength, true);
2572 List<Type> args2 = rs.adjustArgs(mt2.getParameterTypes(), msym2, maxLength, true);
2573 //if arities don't match, exit
2574 if (args1.length() != args2.length()) return;
2575 boolean potentiallyAmbiguous = false;
2576 while (args1.nonEmpty() && args2.nonEmpty()) {
2577 Type s = args1.head;
2578 Type t = args2.head;
2579 if (!types.isSubtype(t, s) && !types.isSubtype(s, t)) {
2580 if (types.isFunctionalInterface(s) && types.isFunctionalInterface(t) &&
2581 types.findDescriptorType(s).getParameterTypes().length() > 0 &&
2582 types.findDescriptorType(s).getParameterTypes().length() ==
2583 types.findDescriptorType(t).getParameterTypes().length()) {
2584 potentiallyAmbiguous = true;
2585 } else {
2586 break;
2587 }
2588 }
2589 args1 = args1.tail;
2590 args2 = args2.tail;
2591 }
2592 if (potentiallyAmbiguous) {
2593 //we found two incompatible functional interfaces with same arity
2594 //this means a call site passing an implicit lambda would be ambigiuous
2595 msym1.flags_field |= POTENTIALLY_AMBIGUOUS;
2596 msym2.flags_field |= POTENTIALLY_AMBIGUOUS;
2597 log.warning(LintCategory.OVERLOADS, pos, "potentially.ambiguous.overload",
2598 msym1, msym1.location(),
2599 msym2, msym2.location());
2600 return;
2601 }
2602 }
2603 }
2604
2605 void checkElemAccessFromSerializableLambda(final JCTree tree) {
2606 if (warnOnAccessToSensitiveMembers) {
2607 Symbol sym = TreeInfo.symbol(tree);
2608 if ((sym.kind & (VAR | MTH)) == 0) {
2609 return;
2610 }
2611
2612 if (sym.kind == VAR) {
2613 if ((sym.flags() & PARAMETER) != 0 ||
2614 sym.isLocal() ||
2615 sym.name == names._this ||
2616 sym.name == names._super) {
2617 return;
2618 }
2619 }
2620
2621 if (!types.isSubtype(sym.owner.type, syms.serializableType) &&
2622 isEffectivelyNonPublic(sym)) {
2623 log.warning(tree.pos(),
2624 "access.to.sensitive.member.from.serializable.element", sym);
2625 }
2626 }
2627 }
2628
2629 private boolean isEffectivelyNonPublic(Symbol sym) {
2630 if (sym.packge() == syms.rootPackage) {
2631 return false;
2632 }
2633
2634 while (sym.kind != Kinds.PCK) {
2635 if ((sym.flags() & PUBLIC) == 0) {
2636 return true;
2637 }
2638 sym = sym.owner;
2639 }
2640 return false;
2641 }
2642
2643 /** Report a conflict between a user symbol and a synthetic symbol.
2644 */
2645 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
2646 if (!sym.type.isErroneous()) {
2647 if (warnOnSyntheticConflicts) {
2648 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
2649 }
2650 else {
2651 log.error(pos, "synthetic.name.conflict", sym, sym.location());
2652 }
2653 }
2654 }
2655
2656 /** Check that class c does not implement directly or indirectly
2657 * the same parameterized interface with two different argument lists.
2658 * @param pos Position to be used for error reporting.
2659 * @param type The type whose interfaces are checked.
2660 */
2661 void checkClassBounds(DiagnosticPosition pos, Type type) {
2662 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
2663 }
2664 //where
2665 /** Enter all interfaces of type `type' into the hash table `seensofar'
2666 * with their class symbol as key and their type as value. Make
2667 * sure no class is entered with two different types.
2668 */
2669 void checkClassBounds(DiagnosticPosition pos,
2670 Map<TypeSymbol,Type> seensofar,
2671 Type type) {
2672 if (type.isErroneous()) return;
2673 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
2674 Type it = l.head;
2675 Type oldit = seensofar.put(it.tsym, it);
2676 if (oldit != null) {
2677 List<Type> oldparams = oldit.allparams();
2678 List<Type> newparams = it.allparams();
2679 if (!types.containsTypeEquivalent(oldparams, newparams))
2680 log.error(pos, "cant.inherit.diff.arg",
2681 it.tsym, Type.toString(oldparams),
2682 Type.toString(newparams));
2683 }
2684 checkClassBounds(pos, seensofar, it);
2685 }
2686 Type st = types.supertype(type);
2687 if (st != null) checkClassBounds(pos, seensofar, st);
2688 }
2689
2690 /** Enter interface into into set.
2691 * If it existed already, issue a "repeated interface" error.
2692 */
2693 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
2694 if (its.contains(it))
2695 log.error(pos, "repeated.interface");
2696 else {
2697 its.add(it);
2698 }
2699 }
2700
2701 /* *************************************************************************
2702 * Check annotations
2703 **************************************************************************/
2704
2705 /**
2706 * Recursively validate annotations values
2707 */
2708 void validateAnnotationTree(JCTree tree) {
2709 class AnnotationValidator extends TreeScanner {
2710 @Override
2711 public void visitAnnotation(JCAnnotation tree) {
2712 if (!tree.type.isErroneous()) {
2713 super.visitAnnotation(tree);
2714 validateAnnotation(tree);
2715 }
2716 }
2717 }
2718 tree.accept(new AnnotationValidator());
2719 }
2720
2721 /**
2722 * {@literal
2723 * Annotation types are restricted to primitives, String, an
2724 * enum, an annotation, Class, Class<?>, Class<? extends
2725 * Anything>, arrays of the preceding.
2726 * }
2727 */
2728 void validateAnnotationType(JCTree restype) {
2729 // restype may be null if an error occurred, so don't bother validating it
2730 if (restype != null) {
2731 validateAnnotationType(restype.pos(), restype.type);
2732 }
2733 }
2734
2735 void validateAnnotationType(DiagnosticPosition pos, Type type) {
2736 if (type.isPrimitive()) return;
2737 if (types.isSameType(type, syms.stringType)) return;
2738 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
2739 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
2740 if (types.cvarLowerBound(type).tsym == syms.classType.tsym) return;
2741 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
2742 validateAnnotationType(pos, types.elemtype(type));
2743 return;
2744 }
2745 log.error(pos, "invalid.annotation.member.type");
2746 }
2747
2748 /**
2749 * "It is also a compile-time error if any method declared in an
2750 * annotation type has a signature that is override-equivalent to
2751 * that of any public or protected method declared in class Object
2752 * or in the interface annotation.Annotation."
2753 *
2754 * @jls 9.6 Annotation Types
2755 */
2756 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
2757 for (Type sup = syms.annotationType; sup.hasTag(CLASS); sup = types.supertype(sup)) {
2758 Scope s = sup.tsym.members();
2759 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
2760 if (e.sym.kind == MTH &&
2761 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
2762 types.overrideEquivalent(m.type, e.sym.type))
2763 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
2764 }
2765 }
2766 }
2767
2768 /** Check the annotations of a symbol.
2769 */
2770 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
2771 for (JCAnnotation a : annotations)
2772 validateAnnotation(a, s);
2773 }
2774
2775 /** Check the type annotations.
2776 */
2777 public void validateTypeAnnotations(List<JCAnnotation> annotations, boolean isTypeParameter) {
2778 for (JCAnnotation a : annotations)
2779 validateTypeAnnotation(a, isTypeParameter);
2780 }
2781
2782 /** Check an annotation of a symbol.
2783 */
2784 private void validateAnnotation(JCAnnotation a, Symbol s) {
2785 validateAnnotationTree(a);
2786
2787 if (!annotationApplicable(a, s))
2788 log.error(a.pos(), "annotation.type.not.applicable");
2789
2790 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
2791 if (s.kind != TYP) {
2792 log.error(a.pos(), "bad.functional.intf.anno");
2793 } else if (!s.isInterface() || (s.flags() & ANNOTATION) != 0) {
2794 log.error(a.pos(), "bad.functional.intf.anno.1", diags.fragment("not.a.functional.intf", s));
2795 }
2796 }
2797 }
2798
2799 public void validateTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
2800 Assert.checkNonNull(a.type, "annotation tree hasn't been attributed yet: " + a);
2801 validateAnnotationTree(a);
2802
2803 if (a.hasTag(TYPE_ANNOTATION) &&
2804 !a.annotationType.type.isErroneous() &&
2805 !isTypeAnnotation(a, isTypeParameter)) {
2806 log.error(a.pos(), "annotation.type.not.applicable");
2807 }
2808 }
2809
2810 /**
2811 * Validate the proposed container 'repeatable' on the
2812 * annotation type symbol 's'. Report errors at position
2813 * 'pos'.
2814 *
2815 * @param s The (annotation)type declaration annotated with a @Repeatable
2816 * @param repeatable the @Repeatable on 's'
2817 * @param pos where to report errors
2818 */
2819 public void validateRepeatable(TypeSymbol s, Attribute.Compound repeatable, DiagnosticPosition pos) {
2820 Assert.check(types.isSameType(repeatable.type, syms.repeatableType));
2821
2822 Type t = null;
2823 List<Pair<MethodSymbol,Attribute>> l = repeatable.values;
2824 if (!l.isEmpty()) {
2825 Assert.check(l.head.fst.name == names.value);
2826 t = ((Attribute.Class)l.head.snd).getValue();
2827 }
2828
2829 if (t == null) {
2830 // errors should already have been reported during Annotate
2831 return;
2832 }
2833
2834 validateValue(t.tsym, s, pos);
2835 validateRetention(t.tsym, s, pos);
2836 validateDocumented(t.tsym, s, pos);
2837 validateInherited(t.tsym, s, pos);
2838 validateTarget(t.tsym, s, pos);
2839 validateDefault(t.tsym, pos);
2840 }
2841
2842 private void validateValue(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) {
2843 Scope.Entry e = container.members().lookup(names.value);
2844 if (e.scope != null && e.sym.kind == MTH) {
2845 MethodSymbol m = (MethodSymbol) e.sym;
2846 Type ret = m.getReturnType();
2847 if (!(ret.hasTag(ARRAY) && types.isSameType(((ArrayType)ret).elemtype, contained.type))) {
2848 log.error(pos, "invalid.repeatable.annotation.value.return",
2849 container, ret, types.makeArrayType(contained.type));
2850 }
2851 } else {
2852 log.error(pos, "invalid.repeatable.annotation.no.value", container);
2853 }
2854 }
2855
2856 private void validateRetention(Symbol container, Symbol contained, DiagnosticPosition pos) {
2857 Attribute.RetentionPolicy containerRetention = types.getRetention(container);
2858 Attribute.RetentionPolicy containedRetention = types.getRetention(contained);
2859
2860 boolean error = false;
2861 switch (containedRetention) {
2862 case RUNTIME:
2863 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) {
2864 error = true;
2865 }
2866 break;
2867 case CLASS:
2868 if (containerRetention == Attribute.RetentionPolicy.SOURCE) {
2869 error = true;
2870 }
2871 }
2872 if (error ) {
2873 log.error(pos, "invalid.repeatable.annotation.retention",
2874 container, containerRetention,
2875 contained, containedRetention);
2876 }
2877 }
2878
2879 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) {
2880 if (contained.attribute(syms.documentedType.tsym) != null) {
2881 if (container.attribute(syms.documentedType.tsym) == null) {
2882 log.error(pos, "invalid.repeatable.annotation.not.documented", container, contained);
2883 }
2884 }
2885 }
2886
2887 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) {
2888 if (contained.attribute(syms.inheritedType.tsym) != null) {
2889 if (container.attribute(syms.inheritedType.tsym) == null) {
2890 log.error(pos, "invalid.repeatable.annotation.not.inherited", container, contained);
2891 }
2892 }
2893 }
2894
2895 private void validateTarget(Symbol container, Symbol contained, DiagnosticPosition pos) {
2896 // The set of targets the container is applicable to must be a subset
2897 // (with respect to annotation target semantics) of the set of targets
2898 // the contained is applicable to. The target sets may be implicit or
2899 // explicit.
2900
2901 Set<Name> containerTargets;
2902 Attribute.Array containerTarget = getAttributeTargetAttribute(container);
2903 if (containerTarget == null) {
2904 containerTargets = getDefaultTargetSet();
2905 } else {
2906 containerTargets = new HashSet<>();
2907 for (Attribute app : containerTarget.values) {
2908 if (!(app instanceof Attribute.Enum)) {
2909 continue; // recovery
2910 }
2911 Attribute.Enum e = (Attribute.Enum)app;
2912 containerTargets.add(e.value.name);
2913 }
2914 }
2915
2916 Set<Name> containedTargets;
2917 Attribute.Array containedTarget = getAttributeTargetAttribute(contained);
2918 if (containedTarget == null) {
2919 containedTargets = getDefaultTargetSet();
2920 } else {
2921 containedTargets = new HashSet<>();
2922 for (Attribute app : containedTarget.values) {
2923 if (!(app instanceof Attribute.Enum)) {
2924 continue; // recovery
2925 }
2926 Attribute.Enum e = (Attribute.Enum)app;
2927 containedTargets.add(e.value.name);
2928 }
2929 }
2930
2931 if (!isTargetSubsetOf(containerTargets, containedTargets)) {
2932 log.error(pos, "invalid.repeatable.annotation.incompatible.target", container, contained);
2933 }
2934 }
2935
2936 /* get a set of names for the default target */
2937 private Set<Name> getDefaultTargetSet() {
2938 if (defaultTargets == null) {
2939 Set<Name> targets = new HashSet<>();
2940 targets.add(names.ANNOTATION_TYPE);
2941 targets.add(names.CONSTRUCTOR);
2942 targets.add(names.FIELD);
2943 targets.add(names.LOCAL_VARIABLE);
2944 targets.add(names.METHOD);
2945 targets.add(names.PACKAGE);
2946 targets.add(names.PARAMETER);
2947 targets.add(names.TYPE);
2948
2949 defaultTargets = java.util.Collections.unmodifiableSet(targets);
2950 }
2951
2952 return defaultTargets;
2953 }
2954 private Set<Name> defaultTargets;
2955
2956
2957 /** Checks that s is a subset of t, with respect to ElementType
2958 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE},
2959 * and {TYPE_USE} covers the set {ANNOTATION_TYPE, TYPE, TYPE_USE,
2960 * TYPE_PARAMETER}.
2961 */
2962 private boolean isTargetSubsetOf(Set<Name> s, Set<Name> t) {
2963 // Check that all elements in s are present in t
2964 for (Name n2 : s) {
2965 boolean currentElementOk = false;
2966 for (Name n1 : t) {
2967 if (n1 == n2) {
2968 currentElementOk = true;
2969 break;
2970 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) {
2971 currentElementOk = true;
2972 break;
2973 } else if (n1 == names.TYPE_USE &&
2974 (n2 == names.TYPE ||
2975 n2 == names.ANNOTATION_TYPE ||
2976 n2 == names.TYPE_PARAMETER)) {
2977 currentElementOk = true;
2978 break;
2979 }
2980 }
2981 if (!currentElementOk)
2982 return false;
2983 }
2984 return true;
2985 }
2986
2987 private void validateDefault(Symbol container, DiagnosticPosition pos) {
2988 // validate that all other elements of containing type has defaults
2989 Scope scope = container.members();
2990 for(Symbol elm : scope.getElements()) {
2991 if (elm.name != names.value &&
2992 elm.kind == Kinds.MTH &&
2993 ((MethodSymbol)elm).defaultValue == null) {
2994 log.error(pos,
2995 "invalid.repeatable.annotation.elem.nondefault",
2996 container,
2997 elm);
2998 }
2999 }
3000 }
3001
3002 /** Is s a method symbol that overrides a method in a superclass? */
3003 boolean isOverrider(Symbol s) {
3004 if (s.kind != MTH || s.isStatic())
3005 return false;
3006 MethodSymbol m = (MethodSymbol)s;
3007 TypeSymbol owner = (TypeSymbol)m.owner;
3008 for (Type sup : types.closure(owner.type)) {
3009 if (sup == owner.type)
3010 continue; // skip "this"
3011 Scope scope = sup.tsym.members();
3012 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
3013 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
3014 return true;
3015 }
3016 }
3017 return false;
3018 }
3019
3020 /** Is the annotation applicable to types? */
3021 protected boolean isTypeAnnotation(JCAnnotation a, boolean isTypeParameter) {
3022 Attribute.Compound atTarget =
3023 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
3024 if (atTarget == null) {
3025 // An annotation without @Target is not a type annotation.
3026 return false;
3027 }
3028
3029 Attribute atValue = atTarget.member(names.value);
3030 if (!(atValue instanceof Attribute.Array)) {
3031 return false; // error recovery
3032 }
3033
3034 Attribute.Array arr = (Attribute.Array) atValue;
3035 for (Attribute app : arr.values) {
3036 if (!(app instanceof Attribute.Enum)) {
3037 return false; // recovery
3038 }
3039 Attribute.Enum e = (Attribute.Enum) app;
3040
3041 if (e.value.name == names.TYPE_USE)
3042 return true;
3043 else if (isTypeParameter && e.value.name == names.TYPE_PARAMETER)
3044 return true;
3045 }
3046 return false;
3047 }
3048
3049 /** Is the annotation applicable to the symbol? */
3050 boolean annotationApplicable(JCAnnotation a, Symbol s) {
3051 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym);
3052 Name[] targets;
3053
3054 if (arr == null) {
3055 targets = defaultTargetMetaInfo(a, s);
3056 } else {
3057 // TODO: can we optimize this?
3058 targets = new Name[arr.values.length];
3059 for (int i=0; i<arr.values.length; ++i) {
3060 Attribute app = arr.values[i];
3061 if (!(app instanceof Attribute.Enum)) {
3062 return true; // recovery
3063 }
3064 Attribute.Enum e = (Attribute.Enum) app;
3065 targets[i] = e.value.name;
3066 }
3067 }
3068 for (Name target : targets) {
3069 if (target == names.TYPE)
3070 { if (s.kind == TYP) return true; }
3071 else if (target == names.FIELD)
3072 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
3073 else if (target == names.METHOD)
3074 { if (s.kind == MTH && !s.isConstructor()) return true; }
3075 else if (target == names.PARAMETER)
3076 { if (s.kind == VAR &&
3077 s.owner.kind == MTH &&
3078 (s.flags() & PARAMETER) != 0)
3079 return true;
3080 }
3081 else if (target == names.CONSTRUCTOR)
3082 { if (s.kind == MTH && s.isConstructor()) return true; }
3083 else if (target == names.LOCAL_VARIABLE)
3084 { if (s.kind == VAR && s.owner.kind == MTH &&
3085 (s.flags() & PARAMETER) == 0)
3086 return true;
3087 }
3088 else if (target == names.ANNOTATION_TYPE)
3089 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
3090 return true;
3091 }
3092 else if (target == names.PACKAGE)
3093 { if (s.kind == PCK) return true; }
3094 else if (target == names.TYPE_USE)
3095 { if (s.kind == TYP ||
3096 s.kind == VAR ||
3097 (s.kind == MTH && !s.isConstructor() &&
3098 !s.type.getReturnType().hasTag(VOID)) ||
3099 (s.kind == MTH && s.isConstructor()))
3100 return true;
3101 }
3102 else if (target == names.TYPE_PARAMETER)
3103 { if (s.kind == TYP && s.type.hasTag(TYPEVAR))
3104 return true;
3105 }
3106 else
3107 return true; // recovery
3108 }
3109 return false;
3110 }
3111
3112
3113 Attribute.Array getAttributeTargetAttribute(Symbol s) {
3114 Attribute.Compound atTarget =
3115 s.attribute(syms.annotationTargetType.tsym);
3116 if (atTarget == null) return null; // ok, is applicable
3117 Attribute atValue = atTarget.member(names.value);
3118 if (!(atValue instanceof Attribute.Array)) return null; // error recovery
3119 return (Attribute.Array) atValue;
3120 }
3121
3122 private final Name[] dfltTargetMeta;
3123 private Name[] defaultTargetMetaInfo(JCAnnotation a, Symbol s) {
3124 return dfltTargetMeta;
3125 }
3126
3127 /** Check an annotation value.
3128 *
3129 * @param a The annotation tree to check
3130 * @return true if this annotation tree is valid, otherwise false
3131 */
3132 public boolean validateAnnotationDeferErrors(JCAnnotation a) {
3133 boolean res = false;
3134 final Log.DiagnosticHandler diagHandler = new Log.DiscardDiagnosticHandler(log);
3135 try {
3136 res = validateAnnotation(a);
3137 } finally {
3138 log.popDiagnosticHandler(diagHandler);
3139 }
3140 return res;
3141 }
3142
3143 private boolean validateAnnotation(JCAnnotation a) {
3144 boolean isValid = true;
3145 // collect an inventory of the annotation elements
3146 Set<MethodSymbol> members = new LinkedHashSet<>();
3147 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
3148 e != null;
3149 e = e.sibling)
3150 if (e.sym.kind == MTH && e.sym.name != names.clinit &&
3151 (e.sym.flags() & SYNTHETIC) == 0)
3152 members.add((MethodSymbol) e.sym);
3153
3154 // remove the ones that are assigned values
3155 for (JCTree arg : a.args) {
3156 if (!arg.hasTag(ASSIGN)) continue; // recovery
3157 JCAssign assign = (JCAssign) arg;
3158 Symbol m = TreeInfo.symbol(assign.lhs);
3159 if (m == null || m.type.isErroneous()) continue;
3160 if (!members.remove(m)) {
3161 isValid = false;
3162 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
3163 m.name, a.type);
3164 }
3165 }
3166
3167 // all the remaining ones better have default values
3168 List<Name> missingDefaults = List.nil();
3169 for (MethodSymbol m : members) {
3170 if (m.defaultValue == null && !m.type.isErroneous()) {
3171 missingDefaults = missingDefaults.append(m.name);
3172 }
3173 }
3174 missingDefaults = missingDefaults.reverse();
3175 if (missingDefaults.nonEmpty()) {
3176 isValid = false;
3177 String key = (missingDefaults.size() > 1)
3178 ? "annotation.missing.default.value.1"
3179 : "annotation.missing.default.value";
3180 log.error(a.pos(), key, a.type, missingDefaults);
3181 }
3182
3183 // special case: java.lang.annotation.Target must not have
3184 // repeated values in its value member
3185 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
3186 a.args.tail == null)
3187 return isValid;
3188
3189 if (!a.args.head.hasTag(ASSIGN)) return false; // error recovery
3190 JCAssign assign = (JCAssign) a.args.head;
3191 Symbol m = TreeInfo.symbol(assign.lhs);
3192 if (m.name != names.value) return false;
3193 JCTree rhs = assign.rhs;
3194 if (!rhs.hasTag(NEWARRAY)) return false;
3195 JCNewArray na = (JCNewArray) rhs;
3196 Set<Symbol> targets = new HashSet<>();
3197 for (JCTree elem : na.elems) {
3198 if (!targets.add(TreeInfo.symbol(elem))) {
3199 isValid = false;
3200 log.error(elem.pos(), "repeated.annotation.target");
3201 }
3202 }
3203 return isValid;
3204 }
3205
3206 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
3207 if (allowAnnotations &&
3208 lint.isEnabled(LintCategory.DEP_ANN) &&
3209 (s.flags() & DEPRECATED) != 0 &&
3210 !syms.deprecatedType.isErroneous() &&
3211 s.attribute(syms.deprecatedType.tsym) == null) {
3212 log.warning(LintCategory.DEP_ANN,
3213 pos, "missing.deprecated.annotation");
3214 }
3215 }
3216
3217 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
3218 if ((s.flags() & DEPRECATED) != 0 &&
3219 (other.flags() & DEPRECATED) == 0 &&
3220 s.outermostClass() != other.outermostClass()) {
3221 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
3222 @Override
3223 public void report() {
3224 warnDeprecated(pos, s);
3225 }
3226 });
3227 }
3228 }
3229
3230 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
3231 if ((s.flags() & PROPRIETARY) != 0) {
3232 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
3233 public void report() {
3234 if (enableSunApiLintControl)
3235 warnSunApi(pos, "sun.proprietary", s);
3236 else
3237 log.mandatoryWarning(pos, "sun.proprietary", s);
3238 }
3239 });
3240 }
3241 }
3242
3243 void checkProfile(final DiagnosticPosition pos, final Symbol s) {
3244 if (profile != Profile.DEFAULT && (s.flags() & NOT_IN_PROFILE) != 0) {
3245 log.error(pos, "not.in.profile", s, profile);
3246 }
3247 }
3248
3249 /* *************************************************************************
3250 * Check for recursive annotation elements.
3251 **************************************************************************/
3252
3253 /** Check for cycles in the graph of annotation elements.
3254 */
3255 void checkNonCyclicElements(JCClassDecl tree) {
3256 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
3257 Assert.check((tree.sym.flags_field & LOCKED) == 0);
3258 try {
3259 tree.sym.flags_field |= LOCKED;
3260 for (JCTree def : tree.defs) {
3261 if (!def.hasTag(METHODDEF)) continue;
3262 JCMethodDecl meth = (JCMethodDecl)def;
3263 checkAnnotationResType(meth.pos(), meth.restype.type);
3264 }
3265 } finally {
3266 tree.sym.flags_field &= ~LOCKED;
3267 tree.sym.flags_field |= ACYCLIC_ANN;
3268 }
3269 }
3270
3271 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
3272 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
3273 return;
3274 if ((tsym.flags_field & LOCKED) != 0) {
3275 log.error(pos, "cyclic.annotation.element");
3276 return;
3277 }
3278 try {
3279 tsym.flags_field |= LOCKED;
3280 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
3281 Symbol s = e.sym;
3282 if (s.kind != Kinds.MTH)
3283 continue;
3284 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
3285 }
3286 } finally {
3287 tsym.flags_field &= ~LOCKED;
3288 tsym.flags_field |= ACYCLIC_ANN;
3289 }
3290 }
3291
3292 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
3293 switch (type.getTag()) {
3294 case CLASS:
3295 if ((type.tsym.flags() & ANNOTATION) != 0)
3296 checkNonCyclicElementsInternal(pos, type.tsym);
3297 break;
3298 case ARRAY:
3299 checkAnnotationResType(pos, types.elemtype(type));
3300 break;
3301 default:
3302 break; // int etc
3303 }
3304 }
3305
3306 /* *************************************************************************
3307 * Check for cycles in the constructor call graph.
3308 **************************************************************************/
3309
3310 /** Check for cycles in the graph of constructors calling other
3311 * constructors.
3312 */
3313 void checkCyclicConstructors(JCClassDecl tree) {
3314 Map<Symbol,Symbol> callMap = new HashMap<>();
3315
3316 // enter each constructor this-call into the map
3317 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
3318 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
3319 if (app == null) continue;
3320 JCMethodDecl meth = (JCMethodDecl) l.head;
3321 if (TreeInfo.name(app.meth) == names._this) {
3322 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
3323 } else {
3324 meth.sym.flags_field |= ACYCLIC;
3325 }
3326 }
3327
3328 // Check for cycles in the map
3329 Symbol[] ctors = new Symbol[0];
3330 ctors = callMap.keySet().toArray(ctors);
3331 for (Symbol caller : ctors) {
3332 checkCyclicConstructor(tree, caller, callMap);
3333 }
3334 }
3335
3336 /** Look in the map to see if the given constructor is part of a
3337 * call cycle.
3338 */
3339 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
3340 Map<Symbol,Symbol> callMap) {
3341 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
3342 if ((ctor.flags_field & LOCKED) != 0) {
3343 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
3344 "recursive.ctor.invocation");
3345 } else {
3346 ctor.flags_field |= LOCKED;
3347 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
3348 ctor.flags_field &= ~LOCKED;
3349 }
3350 ctor.flags_field |= ACYCLIC;
3351 }
3352 }
3353
3354 /* *************************************************************************
3355 * Miscellaneous
3356 **************************************************************************/
3357
3358 /**
3359 * Return the opcode of the operator but emit an error if it is an
3360 * error.
3361 * @param pos position for error reporting.
3362 * @param operator an operator
3363 * @param tag a tree tag
3364 * @param left type of left hand side
3365 * @param right type of right hand side
3366 */
3367 int checkOperator(DiagnosticPosition pos,
3368 OperatorSymbol operator,
3369 JCTree.Tag tag,
3370 Type left,
3371 Type right) {
3372 if (operator.opcode == ByteCodes.error) {
3373 log.error(pos,
3374 "operator.cant.be.applied.1",
3375 treeinfo.operatorName(tag),
3376 left, right);
3377 }
3378 return operator.opcode;
3379 }
3380
3381
3382 /**
3383 * Check for division by integer constant zero
3384 * @param pos Position for error reporting.
3385 * @param operator The operator for the expression
3386 * @param operand The right hand operand for the expression
3387 */
3388 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
3389 if (operand.constValue() != null
3390 && lint.isEnabled(LintCategory.DIVZERO)
3391 && operand.getTag().isSubRangeOf(LONG)
3392 && ((Number) (operand.constValue())).longValue() == 0) {
3393 int opc = ((OperatorSymbol)operator).opcode;
3394 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
3395 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
3396 log.warning(LintCategory.DIVZERO, pos, "div.zero");
3397 }
3398 }
3399 }
3400
3401 /**
3402 * Check for empty statements after if
3403 */
3404 void checkEmptyIf(JCIf tree) {
3405 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null &&
3406 lint.isEnabled(LintCategory.EMPTY))
3407 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), "empty.if");
3408 }
3409
3410 /** Check that symbol is unique in given scope.
3411 * @param pos Position for error reporting.
3412 * @param sym The symbol.
3413 * @param s The scope.
3414 */
3415 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
3416 if (sym.type.isErroneous())
3417 return true;
3418 if (sym.owner.name == names.any) return false;
3419 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
3420 if (sym != e.sym &&
3421 (e.sym.flags() & CLASH) == 0 &&
3422 sym.kind == e.sym.kind &&
3423 sym.name != names.error &&
3424 (sym.kind != MTH ||
3425 types.hasSameArgs(sym.type, e.sym.type) ||
3426 types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
3427 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS)) {
3428 varargsDuplicateError(pos, sym, e.sym);
3429 return true;
3430 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, e.sym.type, false)) {
3431 duplicateErasureError(pos, sym, e.sym);
3432 sym.flags_field |= CLASH;
3433 return true;
3434 } else {
3435 duplicateError(pos, e.sym);
3436 return false;
3437 }
3438 }
3439 }
3440 return true;
3441 }
3442
3443 /** Report duplicate declaration error.
3444 */
3445 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
3446 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
3447 log.error(pos, "name.clash.same.erasure", sym1, sym2);
3448 }
3449 }
3450
3451 /** Check that single-type import is not already imported or top-level defined,
3452 * but make an exception for two single-type imports which denote the same type.
3453 * @param pos Position for error reporting.
3454 * @param sym The symbol.
3455 * @param s The scope
3456 */
3457 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
3458 return checkUniqueImport(pos, sym, s, false);
3459 }
3460
3461 /** Check that static single-type import is not already imported or top-level defined,
3462 * but make an exception for two single-type imports which denote the same type.
3463 * @param pos Position for error reporting.
3464 * @param sym The symbol.
3465 * @param s The scope
3466 */
3467 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
3468 return checkUniqueImport(pos, sym, s, true);
3469 }
3470
3471 /** Check that single-type import is not already imported or top-level defined,
3472 * but make an exception for two single-type imports which denote the same type.
3473 * @param pos Position for error reporting.
3474 * @param sym The symbol.
3475 * @param s The scope.
3476 * @param staticImport Whether or not this was a static import
3477 */
3478 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
3479 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
3480 // is encountered class entered via a class declaration?
3481 boolean isClassDecl = e.scope == s;
3482 if ((isClassDecl || sym != e.sym) &&
3483 sym.kind == e.sym.kind &&
3484 sym.name != names.error &&
3485 (!staticImport || !e.isStaticallyImported())) {
3486 if (!e.sym.type.isErroneous()) {
3487 if (!isClassDecl) {
3488 if (staticImport)
3489 log.error(pos, "already.defined.static.single.import", e.sym);
3490 else
3491 log.error(pos, "already.defined.single.import", e.sym);
3492 }
3493 else if (sym != e.sym)
3494 log.error(pos, "already.defined.this.unit", e.sym);
3495 }
3496 return false;
3497 }
3498 }
3499 return true;
3500 }
3501
3502 /** Check that a qualified name is in canonical form (for import decls).
3503 */
3504 public void checkCanonical(JCTree tree) {
3505 if (!isCanonical(tree))
3506 log.error(tree.pos(), "import.requires.canonical",
3507 TreeInfo.symbol(tree));
3508 }
3509 // where
3510 private boolean isCanonical(JCTree tree) {
3511 while (tree.hasTag(SELECT)) {
3512 JCFieldAccess s = (JCFieldAccess) tree;
3513 if (s.sym.owner != TreeInfo.symbol(s.selected))
3514 return false;
3515 tree = s.selected;
3516 }
3517 return true;
3518 }
3519
3520 /** Check that an auxiliary class is not accessed from any other file than its own.
3521 */
3522 void checkForBadAuxiliaryClassAccess(DiagnosticPosition pos, Env<AttrContext> env, ClassSymbol c) {
3523 if (lint.isEnabled(Lint.LintCategory.AUXILIARYCLASS) &&
3524 (c.flags() & AUXILIARY) != 0 &&
3525 rs.isAccessible(env, c) &&
3526 !fileManager.isSameFile(c.sourcefile, env.toplevel.sourcefile))
3527 {
3528 log.warning(pos, "auxiliary.class.accessed.from.outside.of.its.source.file",
3529 c, c.sourcefile);
3530 }
3531 }
3532
3533 private class ConversionWarner extends Warner {
3534 final String uncheckedKey;
3535 final Type found;
3536 final Type expected;
3537 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
3538 super(pos);
3539 this.uncheckedKey = uncheckedKey;
3540 this.found = found;
3541 this.expected = expected;
3542 }
3543
3544 @Override
3545 public void warn(LintCategory lint) {
3546 boolean warned = this.warned;
3547 super.warn(lint);
3548 if (warned) return; // suppress redundant diagnostics
3549 switch (lint) {
3550 case UNCHECKED:
3551 Check.this.warnUnchecked(pos(), "prob.found.req", diags.fragment(uncheckedKey), found, expected);
3552 break;
3553 case VARARGS:
3554 if (method != null &&
3555 method.attribute(syms.trustMeType.tsym) != null &&
3556 isTrustMeAllowedOnMethod(method) &&
3557 !types.isReifiable(method.type.getParameterTypes().last())) {
3558 Check.this.warnUnsafeVararg(pos(), "varargs.unsafe.use.varargs.param", method.params.last());
3559 }
3560 break;
3561 default:
3562 throw new AssertionError("Unexpected lint: " + lint);
3563 }
3564 }
3565 }
3566
3567 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
3568 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
3569 }
3570
3571 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
3572 return new ConversionWarner(pos, "unchecked.assign", found, expected);
3573 }
3574
3575 public void checkFunctionalInterface(JCClassDecl tree, ClassSymbol cs) {
3576 Compound functionalType = cs.attribute(syms.functionalInterfaceType.tsym);
3577
3578 if (functionalType != null) {
3579 try {
3580 types.findDescriptorSymbol((TypeSymbol)cs);
3581 } catch (Types.FunctionDescriptorLookupError ex) {
3582 DiagnosticPosition pos = tree.pos();
3583 for (JCAnnotation a : tree.getModifiers().annotations) {
3584 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) {
3585 pos = a.pos();
3586 break;
3587 }
3588 }
3589 log.error(pos, "bad.functional.intf.anno.1", ex.getDiagnostic());
3590 }
3591 }
3592 }
3593 }