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src/share/classes/com/sun/tools/javac/comp/Check.java@27bae58329d5
src/share/classes/com/sun/tools/javac/comp/Check.java
Mon, 16 Aug 2010 14:56:23 +0100
- author
- mcimadamore
- date
- Mon, 16 Aug 2010 14:56:23 +0100
- changeset 634
- 27bae58329d5
- parent 632
- ea1930f4b789
- child 638
- d6fe0ea070aa
- permissions
- -rw-r--r--
6976649: javac does not enforce required annotation elements in arrays
Summary: type annotation should take advantage of recursive annotation checking
Reviewed-by: jjg
1 /*
2 * Copyright (c) 1999, 2009, 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 */
26 package com.sun.tools.javac.comp;
28 import com.sun.source.tree.AssignmentTree;
29 import java.util.*;
30 import java.util.Set;
32 import com.sun.tools.javac.code.*;
33 import com.sun.tools.javac.jvm.*;
34 import com.sun.tools.javac.tree.*;
35 import com.sun.tools.javac.util.*;
36 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
37 import com.sun.tools.javac.util.List;
39 import com.sun.tools.javac.tree.JCTree.*;
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.*;
45 import static com.sun.tools.javac.code.Flags.*;
46 import static com.sun.tools.javac.code.Kinds.*;
47 import static com.sun.tools.javac.code.TypeTags.*;
49 /** Type checking helper class for the attribution phase.
50 *
51 * <p><b>This is NOT part of any supported API.
52 * If you write code that depends on this, you do so at your own risk.
53 * This code and its internal interfaces are subject to change or
54 * deletion without notice.</b>
55 */
56 public class Check {
57 protected static final Context.Key<Check> checkKey =
58 new Context.Key<Check>();
60 private final Names names;
61 private final Log log;
62 private final Symtab syms;
63 private final Infer infer;
64 private final Types types;
65 private final JCDiagnostic.Factory diags;
66 private final boolean skipAnnotations;
67 private boolean warnOnSyntheticConflicts;
68 private boolean suppressAbortOnBadClassFile;
69 private final TreeInfo treeinfo;
71 // The set of lint options currently in effect. It is initialized
72 // from the context, and then is set/reset as needed by Attr as it
73 // visits all the various parts of the trees during attribution.
74 private Lint lint;
76 public static Check instance(Context context) {
77 Check instance = context.get(checkKey);
78 if (instance == null)
79 instance = new Check(context);
80 return instance;
81 }
83 protected Check(Context context) {
84 context.put(checkKey, this);
86 names = Names.instance(context);
87 log = Log.instance(context);
88 syms = Symtab.instance(context);
89 infer = Infer.instance(context);
90 this.types = Types.instance(context);
91 diags = JCDiagnostic.Factory.instance(context);
92 Options options = Options.instance(context);
93 lint = Lint.instance(context);
94 treeinfo = TreeInfo.instance(context);
96 Source source = Source.instance(context);
97 allowGenerics = source.allowGenerics();
98 allowAnnotations = source.allowAnnotations();
99 allowCovariantReturns = source.allowCovariantReturns();
100 complexInference = options.get("-complexinference") != null;
101 skipAnnotations = options.get("skipAnnotations") != null;
102 warnOnSyntheticConflicts = options.get("warnOnSyntheticConflicts") != null;
103 suppressAbortOnBadClassFile = options.get("suppressAbortOnBadClassFile") != null;
105 Target target = Target.instance(context);
106 syntheticNameChar = target.syntheticNameChar();
108 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
109 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
110 boolean verboseVarargs = lint.isEnabled(LintCategory.VARARGS);
111 boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
112 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
114 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
115 enforceMandatoryWarnings, "deprecated", LintCategory.DEPRECATION);
116 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
117 enforceMandatoryWarnings, "unchecked", LintCategory.UNCHECKED);
118 unsafeVarargsHandler = new MandatoryWarningHandler(log, verboseVarargs,
119 enforceMandatoryWarnings, "varargs", LintCategory.VARARGS);
120 sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
121 enforceMandatoryWarnings, "sunapi", null);
122 }
124 /** Switch: generics enabled?
125 */
126 boolean allowGenerics;
128 /** Switch: annotations enabled?
129 */
130 boolean allowAnnotations;
132 /** Switch: covariant returns enabled?
133 */
134 boolean allowCovariantReturns;
136 /** Switch: -complexinference option set?
137 */
138 boolean complexInference;
140 /** Character for synthetic names
141 */
142 char syntheticNameChar;
144 /** A table mapping flat names of all compiled classes in this run to their
145 * symbols; maintained from outside.
146 */
147 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
149 /** A handler for messages about deprecated usage.
150 */
151 private MandatoryWarningHandler deprecationHandler;
153 /** A handler for messages about unchecked or unsafe usage.
154 */
155 private MandatoryWarningHandler uncheckedHandler;
157 /** A handler for messages about unchecked or unsafe vararg method decl.
158 */
159 private MandatoryWarningHandler unsafeVarargsHandler;
161 /** A handler for messages about using proprietary API.
162 */
163 private MandatoryWarningHandler sunApiHandler;
165 /* *************************************************************************
166 * Errors and Warnings
167 **************************************************************************/
169 Lint setLint(Lint newLint) {
170 Lint prev = lint;
171 lint = newLint;
172 return prev;
173 }
175 /** Warn about deprecated symbol.
176 * @param pos Position to be used for error reporting.
177 * @param sym The deprecated symbol.
178 */
179 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
180 if (!lint.isSuppressed(LintCategory.DEPRECATION))
181 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
182 }
184 /** Warn about unchecked operation.
185 * @param pos Position to be used for error reporting.
186 * @param msg A string describing the problem.
187 */
188 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
189 if (!lint.isSuppressed(LintCategory.UNCHECKED))
190 uncheckedHandler.report(pos, msg, args);
191 }
193 /** Warn about unsafe vararg method decl.
194 * @param pos Position to be used for error reporting.
195 * @param sym The deprecated symbol.
196 */
197 void warnUnsafeVararg(DiagnosticPosition pos, Type elemType) {
198 if (!lint.isSuppressed(LintCategory.VARARGS))
199 unsafeVarargsHandler.report(pos, "varargs.non.reifiable.type", elemType);
200 }
202 /** Warn about using proprietary API.
203 * @param pos Position to be used for error reporting.
204 * @param msg A string describing the problem.
205 */
206 public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
207 if (!lint.isSuppressed(LintCategory.SUNAPI))
208 sunApiHandler.report(pos, msg, args);
209 }
211 public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
212 if (lint.isEnabled(LintCategory.STATIC))
213 log.warning(LintCategory.STATIC, pos, msg, args);
214 }
216 /**
217 * Report any deferred diagnostics.
218 */
219 public void reportDeferredDiagnostics() {
220 deprecationHandler.reportDeferredDiagnostic();
221 uncheckedHandler.reportDeferredDiagnostic();
222 unsafeVarargsHandler.reportDeferredDiagnostic();
223 sunApiHandler.reportDeferredDiagnostic();
224 }
227 /** Report a failure to complete a class.
228 * @param pos Position to be used for error reporting.
229 * @param ex The failure to report.
230 */
231 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
232 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
233 if (ex instanceof ClassReader.BadClassFile
234 && !suppressAbortOnBadClassFile) throw new Abort();
235 else return syms.errType;
236 }
238 /** Report a type error.
239 * @param pos Position to be used for error reporting.
240 * @param problem A string describing the error.
241 * @param found The type that was found.
242 * @param req The type that was required.
243 */
244 Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
245 log.error(pos, "prob.found.req",
246 problem, found, req);
247 return types.createErrorType(found);
248 }
250 Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
251 log.error(pos, "prob.found.req.1", problem, found, req, explanation);
252 return types.createErrorType(found);
253 }
255 /** Report an error that wrong type tag was found.
256 * @param pos Position to be used for error reporting.
257 * @param required An internationalized string describing the type tag
258 * required.
259 * @param found The type that was found.
260 */
261 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
262 // this error used to be raised by the parser,
263 // but has been delayed to this point:
264 if (found instanceof Type && ((Type)found).tag == VOID) {
265 log.error(pos, "illegal.start.of.type");
266 return syms.errType;
267 }
268 log.error(pos, "type.found.req", found, required);
269 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
270 }
272 /** Report an error that symbol cannot be referenced before super
273 * has been called.
274 * @param pos Position to be used for error reporting.
275 * @param sym The referenced symbol.
276 */
277 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
278 log.error(pos, "cant.ref.before.ctor.called", sym);
279 }
281 /** Report duplicate declaration error.
282 */
283 void duplicateError(DiagnosticPosition pos, Symbol sym) {
284 if (!sym.type.isErroneous()) {
285 log.error(pos, "already.defined", sym, sym.location());
286 }
287 }
289 /** Report array/varargs duplicate declaration
290 */
291 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
292 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
293 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
294 }
295 }
297 /* ************************************************************************
298 * duplicate declaration checking
299 *************************************************************************/
301 /** Check that variable does not hide variable with same name in
302 * immediately enclosing local scope.
303 * @param pos Position for error reporting.
304 * @param v The symbol.
305 * @param s The scope.
306 */
307 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
308 if (s.next != null) {
309 for (Scope.Entry e = s.next.lookup(v.name);
310 e.scope != null && e.sym.owner == v.owner;
311 e = e.next()) {
312 if (e.sym.kind == VAR &&
313 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
314 v.name != names.error) {
315 duplicateError(pos, e.sym);
316 return;
317 }
318 }
319 }
320 }
322 /** Check that a class or interface does not hide a class or
323 * interface with same name in immediately enclosing local scope.
324 * @param pos Position for error reporting.
325 * @param c The symbol.
326 * @param s The scope.
327 */
328 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
329 if (s.next != null) {
330 for (Scope.Entry e = s.next.lookup(c.name);
331 e.scope != null && e.sym.owner == c.owner;
332 e = e.next()) {
333 if (e.sym.kind == TYP &&
334 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
335 c.name != names.error) {
336 duplicateError(pos, e.sym);
337 return;
338 }
339 }
340 }
341 }
343 /** Check that class does not have the same name as one of
344 * its enclosing classes, or as a class defined in its enclosing scope.
345 * return true if class is unique in its enclosing scope.
346 * @param pos Position for error reporting.
347 * @param name The class name.
348 * @param s The enclosing scope.
349 */
350 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
351 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
352 if (e.sym.kind == TYP && e.sym.name != names.error) {
353 duplicateError(pos, e.sym);
354 return false;
355 }
356 }
357 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
358 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
359 duplicateError(pos, sym);
360 return true;
361 }
362 }
363 return true;
364 }
366 /* *************************************************************************
367 * Class name generation
368 **************************************************************************/
370 /** Return name of local class.
371 * This is of the form <enclClass> $ n <classname>
372 * where
373 * enclClass is the flat name of the enclosing class,
374 * classname is the simple name of the local class
375 */
376 Name localClassName(ClassSymbol c) {
377 for (int i=1; ; i++) {
378 Name flatname = names.
379 fromString("" + c.owner.enclClass().flatname +
380 syntheticNameChar + i +
381 c.name);
382 if (compiled.get(flatname) == null) return flatname;
383 }
384 }
386 /* *************************************************************************
387 * Type Checking
388 **************************************************************************/
390 /** Check that a given type is assignable to a given proto-type.
391 * If it is, return the type, otherwise return errType.
392 * @param pos Position to be used for error reporting.
393 * @param found The type that was found.
394 * @param req The type that was required.
395 */
396 Type checkType(DiagnosticPosition pos, Type found, Type req) {
397 return checkType(pos, found, req, "incompatible.types");
398 }
400 Type checkType(DiagnosticPosition pos, Type found, Type req, String errKey) {
401 if (req.tag == ERROR)
402 return req;
403 if (found.tag == FORALL)
404 return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
405 if (req.tag == NONE)
406 return found;
407 if (types.isAssignable(found, req, convertWarner(pos, found, req)))
408 return found;
409 if (found.tag <= DOUBLE && req.tag <= DOUBLE)
410 return typeError(pos, diags.fragment("possible.loss.of.precision"), found, req);
411 if (found.isSuperBound()) {
412 log.error(pos, "assignment.from.super-bound", found);
413 return types.createErrorType(found);
414 }
415 if (req.isExtendsBound()) {
416 log.error(pos, "assignment.to.extends-bound", req);
417 return types.createErrorType(found);
418 }
419 return typeError(pos, diags.fragment(errKey), found, req);
420 }
422 /** Instantiate polymorphic type to some prototype, unless
423 * prototype is `anyPoly' in which case polymorphic type
424 * is returned unchanged.
425 */
426 Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) throws Infer.NoInstanceException {
427 if (pt == Infer.anyPoly && complexInference) {
428 return t;
429 } else if (pt == Infer.anyPoly || pt.tag == NONE) {
430 Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
431 return instantiatePoly(pos, t, newpt, warn);
432 } else if (pt.tag == ERROR) {
433 return pt;
434 } else {
435 try {
436 return infer.instantiateExpr(t, pt, warn);
437 } catch (Infer.NoInstanceException ex) {
438 if (ex.isAmbiguous) {
439 JCDiagnostic d = ex.getDiagnostic();
440 log.error(pos,
441 "undetermined.type" + (d!=null ? ".1" : ""),
442 t, d);
443 return types.createErrorType(pt);
444 } else {
445 JCDiagnostic d = ex.getDiagnostic();
446 return typeError(pos,
447 diags.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
448 t, pt);
449 }
450 } catch (Infer.InvalidInstanceException ex) {
451 JCDiagnostic d = ex.getDiagnostic();
452 log.error(pos, "invalid.inferred.types", t.tvars, d);
453 return types.createErrorType(pt);
454 }
455 }
456 }
458 /** Check that a given type can be cast to a given target type.
459 * Return the result of the cast.
460 * @param pos Position to be used for error reporting.
461 * @param found The type that is being cast.
462 * @param req The target type of the cast.
463 */
464 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
465 if (found.tag == FORALL) {
466 instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
467 return req;
468 } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
469 return req;
470 } else {
471 return typeError(pos,
472 diags.fragment("inconvertible.types"),
473 found, req);
474 }
475 }
476 //where
477 /** Is type a type variable, or a (possibly multi-dimensional) array of
478 * type variables?
479 */
480 boolean isTypeVar(Type t) {
481 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
482 }
484 /** Check that a type is within some bounds.
485 *
486 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
487 * type argument.
488 * @param pos Position to be used for error reporting.
489 * @param a The type that should be bounded by bs.
490 * @param bs The bound.
491 */
492 private void checkExtends(DiagnosticPosition pos, Type a, TypeVar bs) {
493 if (a.isUnbound()) {
494 return;
495 } else if (a.tag != WILDCARD) {
496 a = types.upperBound(a);
497 for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
498 if (!types.isSubtype(a, l.head)) {
499 log.error(pos, "not.within.bounds", a);
500 return;
501 }
502 }
503 } else if (a.isExtendsBound()) {
504 if (!types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings))
505 log.error(pos, "not.within.bounds", a);
506 } else if (a.isSuperBound()) {
507 if (types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound()))
508 log.error(pos, "not.within.bounds", a);
509 }
510 }
512 /** Check that a type is within some bounds.
513 *
514 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
515 * type argument.
516 * @param pos Position to be used for error reporting.
517 * @param a The type that should be bounded by bs.
518 * @param bs The bound.
519 */
520 private void checkCapture(JCTypeApply tree) {
521 List<JCExpression> args = tree.getTypeArguments();
522 for (Type arg : types.capture(tree.type).getTypeArguments()) {
523 if (arg.tag == TYPEVAR && arg.getUpperBound().isErroneous()) {
524 log.error(args.head.pos, "not.within.bounds", args.head.type);
525 break;
526 }
527 args = args.tail;
528 }
529 }
531 /** Check that type is different from 'void'.
532 * @param pos Position to be used for error reporting.
533 * @param t The type to be checked.
534 */
535 Type checkNonVoid(DiagnosticPosition pos, Type t) {
536 if (t.tag == VOID) {
537 log.error(pos, "void.not.allowed.here");
538 return types.createErrorType(t);
539 } else {
540 return t;
541 }
542 }
544 /** Check that type is a class or interface type.
545 * @param pos Position to be used for error reporting.
546 * @param t The type to be checked.
547 */
548 Type checkClassType(DiagnosticPosition pos, Type t) {
549 if (t.tag != CLASS && t.tag != ERROR)
550 return typeTagError(pos,
551 diags.fragment("type.req.class"),
552 (t.tag == TYPEVAR)
553 ? diags.fragment("type.parameter", t)
554 : t);
555 else
556 return t;
557 }
559 /** Check that type is a class or interface type.
560 * @param pos Position to be used for error reporting.
561 * @param t The type to be checked.
562 * @param noBounds True if type bounds are illegal here.
563 */
564 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
565 t = checkClassType(pos, t);
566 if (noBounds && t.isParameterized()) {
567 List<Type> args = t.getTypeArguments();
568 while (args.nonEmpty()) {
569 if (args.head.tag == WILDCARD)
570 return typeTagError(pos,
571 diags.fragment("type.req.exact"),
572 args.head);
573 args = args.tail;
574 }
575 }
576 return t;
577 }
579 /** Check that type is a reifiable class, interface or array type.
580 * @param pos Position to be used for error reporting.
581 * @param t The type to be checked.
582 */
583 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
584 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
585 return typeTagError(pos,
586 diags.fragment("type.req.class.array"),
587 t);
588 } else if (!types.isReifiable(t)) {
589 log.error(pos, "illegal.generic.type.for.instof");
590 return types.createErrorType(t);
591 } else {
592 return t;
593 }
594 }
596 /** Check that type is a reference type, i.e. a class, interface or array type
597 * or a type variable.
598 * @param pos Position to be used for error reporting.
599 * @param t The type to be checked.
600 */
601 Type checkRefType(DiagnosticPosition pos, Type t) {
602 switch (t.tag) {
603 case CLASS:
604 case ARRAY:
605 case TYPEVAR:
606 case WILDCARD:
607 case ERROR:
608 return t;
609 default:
610 return typeTagError(pos,
611 diags.fragment("type.req.ref"),
612 t);
613 }
614 }
616 /** Check that each type is a reference type, i.e. a class, interface or array type
617 * or a type variable.
618 * @param trees Original trees, used for error reporting.
619 * @param types The types to be checked.
620 */
621 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
622 List<JCExpression> tl = trees;
623 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
624 l.head = checkRefType(tl.head.pos(), l.head);
625 tl = tl.tail;
626 }
627 return types;
628 }
630 /** Check that type is a null or reference type.
631 * @param pos Position to be used for error reporting.
632 * @param t The type to be checked.
633 */
634 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
635 switch (t.tag) {
636 case CLASS:
637 case ARRAY:
638 case TYPEVAR:
639 case WILDCARD:
640 case BOT:
641 case ERROR:
642 return t;
643 default:
644 return typeTagError(pos,
645 diags.fragment("type.req.ref"),
646 t);
647 }
648 }
650 /** Check that flag set does not contain elements of two conflicting sets. s
651 * Return true if it doesn't.
652 * @param pos Position to be used for error reporting.
653 * @param flags The set of flags to be checked.
654 * @param set1 Conflicting flags set #1.
655 * @param set2 Conflicting flags set #2.
656 */
657 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
658 if ((flags & set1) != 0 && (flags & set2) != 0) {
659 log.error(pos,
660 "illegal.combination.of.modifiers",
661 asFlagSet(TreeInfo.firstFlag(flags & set1)),
662 asFlagSet(TreeInfo.firstFlag(flags & set2)));
663 return false;
664 } else
665 return true;
666 }
668 /** Check that the type inferred using the diamond operator does not contain
669 * non-denotable types such as captured types or intersection types.
670 * @param t the type inferred using the diamond operator
671 */
672 List<Type> checkDiamond(ClassType t) {
673 DiamondTypeChecker dtc = new DiamondTypeChecker();
674 ListBuffer<Type> buf = ListBuffer.lb();
675 for (Type arg : t.getTypeArguments()) {
676 if (!dtc.visit(arg, null)) {
677 buf.append(arg);
678 }
679 }
680 return buf.toList();
681 }
683 static class DiamondTypeChecker extends Types.SimpleVisitor<Boolean, Void> {
684 public Boolean visitType(Type t, Void s) {
685 return true;
686 }
687 @Override
688 public Boolean visitClassType(ClassType t, Void s) {
689 if (t.isCompound()) {
690 return false;
691 }
692 for (Type targ : t.getTypeArguments()) {
693 if (!visit(targ, s)) {
694 return false;
695 }
696 }
697 return true;
698 }
699 @Override
700 public Boolean visitCapturedType(CapturedType t, Void s) {
701 return false;
702 }
703 }
705 void checkVarargMethodDecl(JCMethodDecl tree) {
706 MethodSymbol m = tree.sym;
707 //check the element type of the vararg
708 if (m.isVarArgs()) {
709 Type varargElemType = types.elemtype(tree.params.last().type);
710 if (!types.isReifiable(varargElemType)) {
711 warnUnsafeVararg(tree.params.head.pos(), varargElemType);
712 }
713 }
714 }
716 /**
717 * Check that vararg method call is sound
718 * @param pos Position to be used for error reporting.
719 * @param argtypes Actual arguments supplied to vararg method.
720 */
721 void checkVararg(DiagnosticPosition pos, List<Type> argtypes, Symbol msym, Env<AttrContext> env) {
722 Env<AttrContext> calleeLintEnv = env;
723 while (calleeLintEnv.info.lint == null)
724 calleeLintEnv = calleeLintEnv.next;
725 Lint calleeLint = calleeLintEnv.info.lint.augment(msym.attributes_field, msym.flags());
726 Type argtype = argtypes.last();
727 if (!types.isReifiable(argtype) && !calleeLint.isSuppressed(Lint.LintCategory.VARARGS)) {
728 warnUnchecked(pos,
729 "unchecked.generic.array.creation",
730 argtype);
731 }
732 }
734 /** Check that given modifiers are legal for given symbol and
735 * return modifiers together with any implicit modififiers for that symbol.
736 * Warning: we can't use flags() here since this method
737 * is called during class enter, when flags() would cause a premature
738 * completion.
739 * @param pos Position to be used for error reporting.
740 * @param flags The set of modifiers given in a definition.
741 * @param sym The defined symbol.
742 */
743 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
744 long mask;
745 long implicit = 0;
746 switch (sym.kind) {
747 case VAR:
748 if (sym.owner.kind != TYP)
749 mask = LocalVarFlags;
750 else if ((sym.owner.flags_field & INTERFACE) != 0)
751 mask = implicit = InterfaceVarFlags;
752 else
753 mask = VarFlags;
754 break;
755 case MTH:
756 if (sym.name == names.init) {
757 if ((sym.owner.flags_field & ENUM) != 0) {
758 // enum constructors cannot be declared public or
759 // protected and must be implicitly or explicitly
760 // private
761 implicit = PRIVATE;
762 mask = PRIVATE;
763 } else
764 mask = ConstructorFlags;
765 } else if ((sym.owner.flags_field & INTERFACE) != 0)
766 mask = implicit = InterfaceMethodFlags;
767 else {
768 mask = MethodFlags;
769 }
770 // Imply STRICTFP if owner has STRICTFP set.
771 if (((flags|implicit) & Flags.ABSTRACT) == 0)
772 implicit |= sym.owner.flags_field & STRICTFP;
773 break;
774 case TYP:
775 if (sym.isLocal()) {
776 mask = LocalClassFlags;
777 if (sym.name.isEmpty()) { // Anonymous class
778 // Anonymous classes in static methods are themselves static;
779 // that's why we admit STATIC here.
780 mask |= STATIC;
781 // JLS: Anonymous classes are final.
782 implicit |= FINAL;
783 }
784 if ((sym.owner.flags_field & STATIC) == 0 &&
785 (flags & ENUM) != 0)
786 log.error(pos, "enums.must.be.static");
787 } else if (sym.owner.kind == TYP) {
788 mask = MemberClassFlags;
789 if (sym.owner.owner.kind == PCK ||
790 (sym.owner.flags_field & STATIC) != 0)
791 mask |= STATIC;
792 else if ((flags & ENUM) != 0)
793 log.error(pos, "enums.must.be.static");
794 // Nested interfaces and enums are always STATIC (Spec ???)
795 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
796 } else {
797 mask = ClassFlags;
798 }
799 // Interfaces are always ABSTRACT
800 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
802 if ((flags & ENUM) != 0) {
803 // enums can't be declared abstract or final
804 mask &= ~(ABSTRACT | FINAL);
805 implicit |= implicitEnumFinalFlag(tree);
806 }
807 // Imply STRICTFP if owner has STRICTFP set.
808 implicit |= sym.owner.flags_field & STRICTFP;
809 break;
810 default:
811 throw new AssertionError();
812 }
813 long illegal = flags & StandardFlags & ~mask;
814 if (illegal != 0) {
815 if ((illegal & INTERFACE) != 0) {
816 log.error(pos, "intf.not.allowed.here");
817 mask |= INTERFACE;
818 }
819 else {
820 log.error(pos,
821 "mod.not.allowed.here", asFlagSet(illegal));
822 }
823 }
824 else if ((sym.kind == TYP ||
825 // ISSUE: Disallowing abstract&private is no longer appropriate
826 // in the presence of inner classes. Should it be deleted here?
827 checkDisjoint(pos, flags,
828 ABSTRACT,
829 PRIVATE | STATIC))
830 &&
831 checkDisjoint(pos, flags,
832 ABSTRACT | INTERFACE,
833 FINAL | NATIVE | SYNCHRONIZED)
834 &&
835 checkDisjoint(pos, flags,
836 PUBLIC,
837 PRIVATE | PROTECTED)
838 &&
839 checkDisjoint(pos, flags,
840 PRIVATE,
841 PUBLIC | PROTECTED)
842 &&
843 checkDisjoint(pos, flags,
844 FINAL,
845 VOLATILE)
846 &&
847 (sym.kind == TYP ||
848 checkDisjoint(pos, flags,
849 ABSTRACT | NATIVE,
850 STRICTFP))) {
851 // skip
852 }
853 return flags & (mask | ~StandardFlags) | implicit;
854 }
857 /** Determine if this enum should be implicitly final.
858 *
859 * If the enum has no specialized enum contants, it is final.
860 *
861 * If the enum does have specialized enum contants, it is
862 * <i>not</i> final.
863 */
864 private long implicitEnumFinalFlag(JCTree tree) {
865 if (tree.getTag() != JCTree.CLASSDEF) return 0;
866 class SpecialTreeVisitor extends JCTree.Visitor {
867 boolean specialized;
868 SpecialTreeVisitor() {
869 this.specialized = false;
870 };
872 @Override
873 public void visitTree(JCTree tree) { /* no-op */ }
875 @Override
876 public void visitVarDef(JCVariableDecl tree) {
877 if ((tree.mods.flags & ENUM) != 0) {
878 if (tree.init instanceof JCNewClass &&
879 ((JCNewClass) tree.init).def != null) {
880 specialized = true;
881 }
882 }
883 }
884 }
886 SpecialTreeVisitor sts = new SpecialTreeVisitor();
887 JCClassDecl cdef = (JCClassDecl) tree;
888 for (JCTree defs: cdef.defs) {
889 defs.accept(sts);
890 if (sts.specialized) return 0;
891 }
892 return FINAL;
893 }
895 /* *************************************************************************
896 * Type Validation
897 **************************************************************************/
899 /** Validate a type expression. That is,
900 * check that all type arguments of a parametric type are within
901 * their bounds. This must be done in a second phase after type attributon
902 * since a class might have a subclass as type parameter bound. E.g:
903 *
904 * class B<A extends C> { ... }
905 * class C extends B<C> { ... }
906 *
907 * and we can't make sure that the bound is already attributed because
908 * of possible cycles.
909 */
910 private Validator validator = new Validator();
912 /** Visitor method: Validate a type expression, if it is not null, catching
913 * and reporting any completion failures.
914 */
915 void validate(JCTree tree, Env<AttrContext> env) {
916 try {
917 if (tree != null) {
918 validator.env = env;
919 tree.accept(validator);
920 checkRaw(tree, env);
921 }
922 } catch (CompletionFailure ex) {
923 completionError(tree.pos(), ex);
924 }
925 }
926 //where
927 void checkRaw(JCTree tree, Env<AttrContext> env) {
928 if (lint.isEnabled(Lint.LintCategory.RAW) &&
929 tree.type.tag == CLASS &&
930 !TreeInfo.isDiamond(tree) &&
931 !env.enclClass.name.isEmpty() && //anonymous or intersection
932 tree.type.isRaw()) {
933 log.warning(Lint.LintCategory.RAW,
934 tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
935 }
936 }
938 /** Visitor method: Validate a list of type expressions.
939 */
940 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
941 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
942 validate(l.head, env);
943 }
945 /** A visitor class for type validation.
946 */
947 class Validator extends JCTree.Visitor {
949 @Override
950 public void visitTypeArray(JCArrayTypeTree tree) {
951 validate(tree.elemtype, env);
952 }
954 @Override
955 public void visitTypeApply(JCTypeApply tree) {
956 if (tree.type.tag == CLASS) {
957 List<Type> formals = tree.type.tsym.type.allparams();
958 List<Type> actuals = tree.type.allparams();
959 List<JCExpression> args = tree.arguments;
960 List<Type> forms = tree.type.tsym.type.getTypeArguments();
961 ListBuffer<Type> tvars_buf = new ListBuffer<Type>();
963 // For matching pairs of actual argument types `a' and
964 // formal type parameters with declared bound `b' ...
965 while (args.nonEmpty() && forms.nonEmpty()) {
966 validate(args.head, env);
968 // exact type arguments needs to know their
969 // bounds (for upper and lower bound
970 // calculations). So we create new TypeVars with
971 // bounds substed with actuals.
972 tvars_buf.append(types.substBound(((TypeVar)forms.head),
973 formals,
974 actuals));
976 args = args.tail;
977 forms = forms.tail;
978 }
980 args = tree.arguments;
981 List<Type> tvars_cap = types.substBounds(formals,
982 formals,
983 types.capture(tree.type).allparams());
984 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
985 // Let the actual arguments know their bound
986 args.head.type.withTypeVar((TypeVar)tvars_cap.head);
987 args = args.tail;
988 tvars_cap = tvars_cap.tail;
989 }
991 args = tree.arguments;
992 List<Type> tvars = tvars_buf.toList();
994 while (args.nonEmpty() && tvars.nonEmpty()) {
995 Type actual = types.subst(args.head.type,
996 tree.type.tsym.type.getTypeArguments(),
997 tvars_buf.toList());
998 checkExtends(args.head.pos(),
999 actual,
1000 (TypeVar)tvars.head);
1001 args = args.tail;
1002 tvars = tvars.tail;
1003 }
1005 checkCapture(tree);
1007 // Check that this type is either fully parameterized, or
1008 // not parameterized at all.
1009 if (tree.type.getEnclosingType().isRaw())
1010 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1011 if (tree.clazz.getTag() == JCTree.SELECT)
1012 visitSelectInternal((JCFieldAccess)tree.clazz);
1013 }
1014 }
1016 @Override
1017 public void visitTypeParameter(JCTypeParameter tree) {
1018 validate(tree.bounds, env);
1019 checkClassBounds(tree.pos(), tree.type);
1020 }
1022 @Override
1023 public void visitWildcard(JCWildcard tree) {
1024 if (tree.inner != null)
1025 validate(tree.inner, env);
1026 }
1028 @Override
1029 public void visitSelect(JCFieldAccess tree) {
1030 if (tree.type.tag == CLASS) {
1031 visitSelectInternal(tree);
1033 // Check that this type is either fully parameterized, or
1034 // not parameterized at all.
1035 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1036 log.error(tree.pos(), "improperly.formed.type.param.missing");
1037 }
1038 }
1039 public void visitSelectInternal(JCFieldAccess tree) {
1040 if (tree.type.tsym.isStatic() &&
1041 tree.selected.type.isParameterized()) {
1042 // The enclosing type is not a class, so we are
1043 // looking at a static member type. However, the
1044 // qualifying expression is parameterized.
1045 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1046 } else {
1047 // otherwise validate the rest of the expression
1048 tree.selected.accept(this);
1049 }
1050 }
1052 @Override
1053 public void visitAnnotatedType(JCAnnotatedType tree) {
1054 tree.underlyingType.accept(this);
1055 }
1057 /** Default visitor method: do nothing.
1058 */
1059 @Override
1060 public void visitTree(JCTree tree) {
1061 }
1063 Env<AttrContext> env;
1064 }
1066 /* *************************************************************************
1067 * Exception checking
1068 **************************************************************************/
1070 /* The following methods treat classes as sets that contain
1071 * the class itself and all their subclasses
1072 */
1074 /** Is given type a subtype of some of the types in given list?
1075 */
1076 boolean subset(Type t, List<Type> ts) {
1077 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1078 if (types.isSubtype(t, l.head)) return true;
1079 return false;
1080 }
1082 /** Is given type a subtype or supertype of
1083 * some of the types in given list?
1084 */
1085 boolean intersects(Type t, List<Type> ts) {
1086 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1087 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1088 return false;
1089 }
1091 /** Add type set to given type list, unless it is a subclass of some class
1092 * in the list.
1093 */
1094 List<Type> incl(Type t, List<Type> ts) {
1095 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1096 }
1098 /** Remove type set from type set list.
1099 */
1100 List<Type> excl(Type t, List<Type> ts) {
1101 if (ts.isEmpty()) {
1102 return ts;
1103 } else {
1104 List<Type> ts1 = excl(t, ts.tail);
1105 if (types.isSubtype(ts.head, t)) return ts1;
1106 else if (ts1 == ts.tail) return ts;
1107 else return ts1.prepend(ts.head);
1108 }
1109 }
1111 /** Form the union of two type set lists.
1112 */
1113 List<Type> union(List<Type> ts1, List<Type> ts2) {
1114 List<Type> ts = ts1;
1115 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1116 ts = incl(l.head, ts);
1117 return ts;
1118 }
1120 /** Form the difference of two type lists.
1121 */
1122 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1123 List<Type> ts = ts1;
1124 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1125 ts = excl(l.head, ts);
1126 return ts;
1127 }
1129 /** Form the intersection of two type lists.
1130 */
1131 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1132 List<Type> ts = List.nil();
1133 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1134 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1135 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1136 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1137 return ts;
1138 }
1140 /** Is exc an exception symbol that need not be declared?
1141 */
1142 boolean isUnchecked(ClassSymbol exc) {
1143 return
1144 exc.kind == ERR ||
1145 exc.isSubClass(syms.errorType.tsym, types) ||
1146 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1147 }
1149 /** Is exc an exception type that need not be declared?
1150 */
1151 boolean isUnchecked(Type exc) {
1152 return
1153 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
1154 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
1155 exc.tag == BOT;
1156 }
1158 /** Same, but handling completion failures.
1159 */
1160 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1161 try {
1162 return isUnchecked(exc);
1163 } catch (CompletionFailure ex) {
1164 completionError(pos, ex);
1165 return true;
1166 }
1167 }
1169 /** Is exc handled by given exception list?
1170 */
1171 boolean isHandled(Type exc, List<Type> handled) {
1172 return isUnchecked(exc) || subset(exc, handled);
1173 }
1175 /** Return all exceptions in thrown list that are not in handled list.
1176 * @param thrown The list of thrown exceptions.
1177 * @param handled The list of handled exceptions.
1178 */
1179 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1180 List<Type> unhandled = List.nil();
1181 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1182 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1183 return unhandled;
1184 }
1186 /* *************************************************************************
1187 * Overriding/Implementation checking
1188 **************************************************************************/
1190 /** The level of access protection given by a flag set,
1191 * where PRIVATE is highest and PUBLIC is lowest.
1192 */
1193 static int protection(long flags) {
1194 switch ((short)(flags & AccessFlags)) {
1195 case PRIVATE: return 3;
1196 case PROTECTED: return 1;
1197 default:
1198 case PUBLIC: return 0;
1199 case 0: return 2;
1200 }
1201 }
1203 /** A customized "cannot override" error message.
1204 * @param m The overriding method.
1205 * @param other The overridden method.
1206 * @return An internationalized string.
1207 */
1208 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1209 String key;
1210 if ((other.owner.flags() & INTERFACE) == 0)
1211 key = "cant.override";
1212 else if ((m.owner.flags() & INTERFACE) == 0)
1213 key = "cant.implement";
1214 else
1215 key = "clashes.with";
1216 return diags.fragment(key, m, m.location(), other, other.location());
1217 }
1219 /** A customized "override" warning message.
1220 * @param m The overriding method.
1221 * @param other The overridden method.
1222 * @return An internationalized string.
1223 */
1224 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1225 String key;
1226 if ((other.owner.flags() & INTERFACE) == 0)
1227 key = "unchecked.override";
1228 else if ((m.owner.flags() & INTERFACE) == 0)
1229 key = "unchecked.implement";
1230 else
1231 key = "unchecked.clash.with";
1232 return diags.fragment(key, m, m.location(), other, other.location());
1233 }
1235 /** A customized "override" warning message.
1236 * @param m The overriding method.
1237 * @param other The overridden method.
1238 * @return An internationalized string.
1239 */
1240 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1241 String key;
1242 if ((other.owner.flags() & INTERFACE) == 0)
1243 key = "varargs.override";
1244 else if ((m.owner.flags() & INTERFACE) == 0)
1245 key = "varargs.implement";
1246 else
1247 key = "varargs.clash.with";
1248 return diags.fragment(key, m, m.location(), other, other.location());
1249 }
1251 /** Check that this method conforms with overridden method 'other'.
1252 * where `origin' is the class where checking started.
1253 * Complications:
1254 * (1) Do not check overriding of synthetic methods
1255 * (reason: they might be final).
1256 * todo: check whether this is still necessary.
1257 * (2) Admit the case where an interface proxy throws fewer exceptions
1258 * than the method it implements. Augment the proxy methods with the
1259 * undeclared exceptions in this case.
1260 * (3) When generics are enabled, admit the case where an interface proxy
1261 * has a result type
1262 * extended by the result type of the method it implements.
1263 * Change the proxies result type to the smaller type in this case.
1264 *
1265 * @param tree The tree from which positions
1266 * are extracted for errors.
1267 * @param m The overriding method.
1268 * @param other The overridden method.
1269 * @param origin The class of which the overriding method
1270 * is a member.
1271 */
1272 void checkOverride(JCTree tree,
1273 MethodSymbol m,
1274 MethodSymbol other,
1275 ClassSymbol origin) {
1276 // Don't check overriding of synthetic methods or by bridge methods.
1277 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1278 return;
1279 }
1281 // Error if static method overrides instance method (JLS 8.4.6.2).
1282 if ((m.flags() & STATIC) != 0 &&
1283 (other.flags() & STATIC) == 0) {
1284 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1285 cannotOverride(m, other));
1286 return;
1287 }
1289 // Error if instance method overrides static or final
1290 // method (JLS 8.4.6.1).
1291 if ((other.flags() & FINAL) != 0 ||
1292 (m.flags() & STATIC) == 0 &&
1293 (other.flags() & STATIC) != 0) {
1294 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1295 cannotOverride(m, other),
1296 asFlagSet(other.flags() & (FINAL | STATIC)));
1297 return;
1298 }
1300 if ((m.owner.flags() & ANNOTATION) != 0) {
1301 // handled in validateAnnotationMethod
1302 return;
1303 }
1305 // Error if overriding method has weaker access (JLS 8.4.6.3).
1306 if ((origin.flags() & INTERFACE) == 0 &&
1307 protection(m.flags()) > protection(other.flags())) {
1308 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1309 cannotOverride(m, other),
1310 other.flags() == 0 ?
1311 Flag.PACKAGE :
1312 asFlagSet(other.flags() & AccessFlags));
1313 return;
1314 }
1316 Type mt = types.memberType(origin.type, m);
1317 Type ot = types.memberType(origin.type, other);
1318 // Error if overriding result type is different
1319 // (or, in the case of generics mode, not a subtype) of
1320 // overridden result type. We have to rename any type parameters
1321 // before comparing types.
1322 List<Type> mtvars = mt.getTypeArguments();
1323 List<Type> otvars = ot.getTypeArguments();
1324 Type mtres = mt.getReturnType();
1325 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1327 overrideWarner.warned = false;
1328 boolean resultTypesOK =
1329 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1330 if (!resultTypesOK) {
1331 if (!allowCovariantReturns &&
1332 m.owner != origin &&
1333 m.owner.isSubClass(other.owner, types)) {
1334 // allow limited interoperability with covariant returns
1335 } else {
1336 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1337 "override.incompatible.ret",
1338 cannotOverride(m, other),
1339 mtres, otres);
1340 return;
1341 }
1342 } else if (overrideWarner.warned) {
1343 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1344 "override.unchecked.ret",
1345 uncheckedOverrides(m, other),
1346 mtres, otres);
1347 }
1349 // Error if overriding method throws an exception not reported
1350 // by overridden method.
1351 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1352 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1353 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1354 if (unhandledErased.nonEmpty()) {
1355 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1356 "override.meth.doesnt.throw",
1357 cannotOverride(m, other),
1358 unhandledUnerased.head);
1359 return;
1360 }
1361 else if (unhandledUnerased.nonEmpty()) {
1362 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1363 "override.unchecked.thrown",
1364 cannotOverride(m, other),
1365 unhandledUnerased.head);
1366 return;
1367 }
1369 // Optional warning if varargs don't agree
1370 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1371 && lint.isEnabled(Lint.LintCategory.OVERRIDES)) {
1372 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1373 ((m.flags() & Flags.VARARGS) != 0)
1374 ? "override.varargs.missing"
1375 : "override.varargs.extra",
1376 varargsOverrides(m, other));
1377 }
1379 // Warn if instance method overrides bridge method (compiler spec ??)
1380 if ((other.flags() & BRIDGE) != 0) {
1381 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1382 uncheckedOverrides(m, other));
1383 }
1385 // Warn if a deprecated method overridden by a non-deprecated one.
1386 if ((other.flags() & DEPRECATED) != 0
1387 && (m.flags() & DEPRECATED) == 0
1388 && m.outermostClass() != other.outermostClass()
1389 && !isDeprecatedOverrideIgnorable(other, origin)) {
1390 warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
1391 }
1392 }
1393 // where
1394 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1395 // If the method, m, is defined in an interface, then ignore the issue if the method
1396 // is only inherited via a supertype and also implemented in the supertype,
1397 // because in that case, we will rediscover the issue when examining the method
1398 // in the supertype.
1399 // If the method, m, is not defined in an interface, then the only time we need to
1400 // address the issue is when the method is the supertype implemementation: any other
1401 // case, we will have dealt with when examining the supertype classes
1402 ClassSymbol mc = m.enclClass();
1403 Type st = types.supertype(origin.type);
1404 if (st.tag != CLASS)
1405 return true;
1406 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1408 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1409 List<Type> intfs = types.interfaces(origin.type);
1410 return (intfs.contains(mc.type) ? false : (stimpl != null));
1411 }
1412 else
1413 return (stimpl != m);
1414 }
1417 // used to check if there were any unchecked conversions
1418 Warner overrideWarner = new Warner();
1420 /** Check that a class does not inherit two concrete methods
1421 * with the same signature.
1422 * @param pos Position to be used for error reporting.
1423 * @param site The class type to be checked.
1424 */
1425 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1426 Type sup = types.supertype(site);
1427 if (sup.tag != CLASS) return;
1429 for (Type t1 = sup;
1430 t1.tsym.type.isParameterized();
1431 t1 = types.supertype(t1)) {
1432 for (Scope.Entry e1 = t1.tsym.members().elems;
1433 e1 != null;
1434 e1 = e1.sibling) {
1435 Symbol s1 = e1.sym;
1436 if (s1.kind != MTH ||
1437 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1438 !s1.isInheritedIn(site.tsym, types) ||
1439 ((MethodSymbol)s1).implementation(site.tsym,
1440 types,
1441 true) != s1)
1442 continue;
1443 Type st1 = types.memberType(t1, s1);
1444 int s1ArgsLength = st1.getParameterTypes().length();
1445 if (st1 == s1.type) continue;
1447 for (Type t2 = sup;
1448 t2.tag == CLASS;
1449 t2 = types.supertype(t2)) {
1450 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1451 e2.scope != null;
1452 e2 = e2.next()) {
1453 Symbol s2 = e2.sym;
1454 if (s2 == s1 ||
1455 s2.kind != MTH ||
1456 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1457 s2.type.getParameterTypes().length() != s1ArgsLength ||
1458 !s2.isInheritedIn(site.tsym, types) ||
1459 ((MethodSymbol)s2).implementation(site.tsym,
1460 types,
1461 true) != s2)
1462 continue;
1463 Type st2 = types.memberType(t2, s2);
1464 if (types.overrideEquivalent(st1, st2))
1465 log.error(pos, "concrete.inheritance.conflict",
1466 s1, t1, s2, t2, sup);
1467 }
1468 }
1469 }
1470 }
1471 }
1473 /** Check that classes (or interfaces) do not each define an abstract
1474 * method with same name and arguments but incompatible return types.
1475 * @param pos Position to be used for error reporting.
1476 * @param t1 The first argument type.
1477 * @param t2 The second argument type.
1478 */
1479 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1480 Type t1,
1481 Type t2) {
1482 return checkCompatibleAbstracts(pos, t1, t2,
1483 types.makeCompoundType(t1, t2));
1484 }
1486 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1487 Type t1,
1488 Type t2,
1489 Type site) {
1490 Symbol sym = firstIncompatibility(t1, t2, site);
1491 if (sym != null) {
1492 log.error(pos, "types.incompatible.diff.ret",
1493 t1, t2, sym.name +
1494 "(" + types.memberType(t2, sym).getParameterTypes() + ")");
1495 return false;
1496 }
1497 return true;
1498 }
1500 /** Return the first method which is defined with same args
1501 * but different return types in two given interfaces, or null if none
1502 * exists.
1503 * @param t1 The first type.
1504 * @param t2 The second type.
1505 * @param site The most derived type.
1506 * @returns symbol from t2 that conflicts with one in t1.
1507 */
1508 private Symbol firstIncompatibility(Type t1, Type t2, Type site) {
1509 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1510 closure(t1, interfaces1);
1511 Map<TypeSymbol,Type> interfaces2;
1512 if (t1 == t2)
1513 interfaces2 = interfaces1;
1514 else
1515 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1517 for (Type t3 : interfaces1.values()) {
1518 for (Type t4 : interfaces2.values()) {
1519 Symbol s = firstDirectIncompatibility(t3, t4, site);
1520 if (s != null) return s;
1521 }
1522 }
1523 return null;
1524 }
1526 /** Compute all the supertypes of t, indexed by type symbol. */
1527 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1528 if (t.tag != CLASS) return;
1529 if (typeMap.put(t.tsym, t) == null) {
1530 closure(types.supertype(t), typeMap);
1531 for (Type i : types.interfaces(t))
1532 closure(i, typeMap);
1533 }
1534 }
1536 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1537 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1538 if (t.tag != CLASS) return;
1539 if (typesSkip.get(t.tsym) != null) return;
1540 if (typeMap.put(t.tsym, t) == null) {
1541 closure(types.supertype(t), typesSkip, typeMap);
1542 for (Type i : types.interfaces(t))
1543 closure(i, typesSkip, typeMap);
1544 }
1545 }
1547 /** Return the first method in t2 that conflicts with a method from t1. */
1548 private Symbol firstDirectIncompatibility(Type t1, Type t2, Type site) {
1549 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1550 Symbol s1 = e1.sym;
1551 Type st1 = null;
1552 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1553 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1554 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1555 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1556 Symbol s2 = e2.sym;
1557 if (s1 == s2) continue;
1558 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1559 if (st1 == null) st1 = types.memberType(t1, s1);
1560 Type st2 = types.memberType(t2, s2);
1561 if (types.overrideEquivalent(st1, st2)) {
1562 List<Type> tvars1 = st1.getTypeArguments();
1563 List<Type> tvars2 = st2.getTypeArguments();
1564 Type rt1 = st1.getReturnType();
1565 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1566 boolean compat =
1567 types.isSameType(rt1, rt2) ||
1568 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1569 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1570 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1571 checkCommonOverriderIn(s1,s2,site);
1572 if (!compat) return s2;
1573 }
1574 }
1575 }
1576 return null;
1577 }
1578 //WHERE
1579 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1580 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1581 Type st1 = types.memberType(site, s1);
1582 Type st2 = types.memberType(site, s2);
1583 closure(site, supertypes);
1584 for (Type t : supertypes.values()) {
1585 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1586 Symbol s3 = e.sym;
1587 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1588 Type st3 = types.memberType(site,s3);
1589 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1590 if (s3.owner == site.tsym) {
1591 return true;
1592 }
1593 List<Type> tvars1 = st1.getTypeArguments();
1594 List<Type> tvars2 = st2.getTypeArguments();
1595 List<Type> tvars3 = st3.getTypeArguments();
1596 Type rt1 = st1.getReturnType();
1597 Type rt2 = st2.getReturnType();
1598 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1599 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1600 boolean compat =
1601 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1602 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1603 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1604 if (compat)
1605 return true;
1606 }
1607 }
1608 }
1609 return false;
1610 }
1612 /** Check that a given method conforms with any method it overrides.
1613 * @param tree The tree from which positions are extracted
1614 * for errors.
1615 * @param m The overriding method.
1616 */
1617 void checkOverride(JCTree tree, MethodSymbol m) {
1618 ClassSymbol origin = (ClassSymbol)m.owner;
1619 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1620 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1621 log.error(tree.pos(), "enum.no.finalize");
1622 return;
1623 }
1624 for (Type t = types.supertype(origin.type); t.tag == CLASS;
1625 t = types.supertype(t)) {
1626 TypeSymbol c = t.tsym;
1627 Scope.Entry e = c.members().lookup(m.name);
1628 while (e.scope != null) {
1629 if (m.overrides(e.sym, origin, types, false))
1630 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1631 else if (e.sym.kind == MTH &&
1632 e.sym.isInheritedIn(origin, types) &&
1633 (e.sym.flags() & SYNTHETIC) == 0 &&
1634 !m.isConstructor()) {
1635 Type er1 = m.erasure(types);
1636 Type er2 = e.sym.erasure(types);
1637 if (types.isSameTypes(er1.getParameterTypes(),
1638 er2.getParameterTypes())) {
1639 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1640 "name.clash.same.erasure.no.override",
1641 m, m.location(),
1642 e.sym, e.sym.location());
1643 }
1644 }
1645 e = e.next();
1646 }
1647 }
1648 }
1650 /** Check that all abstract members of given class have definitions.
1651 * @param pos Position to be used for error reporting.
1652 * @param c The class.
1653 */
1654 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1655 try {
1656 MethodSymbol undef = firstUndef(c, c);
1657 if (undef != null) {
1658 if ((c.flags() & ENUM) != 0 &&
1659 types.supertype(c.type).tsym == syms.enumSym &&
1660 (c.flags() & FINAL) == 0) {
1661 // add the ABSTRACT flag to an enum
1662 c.flags_field |= ABSTRACT;
1663 } else {
1664 MethodSymbol undef1 =
1665 new MethodSymbol(undef.flags(), undef.name,
1666 types.memberType(c.type, undef), undef.owner);
1667 log.error(pos, "does.not.override.abstract",
1668 c, undef1, undef1.location());
1669 }
1670 }
1671 } catch (CompletionFailure ex) {
1672 completionError(pos, ex);
1673 }
1674 }
1675 //where
1676 /** Return first abstract member of class `c' that is not defined
1677 * in `impl', null if there is none.
1678 */
1679 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1680 MethodSymbol undef = null;
1681 // Do not bother to search in classes that are not abstract,
1682 // since they cannot have abstract members.
1683 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1684 Scope s = c.members();
1685 for (Scope.Entry e = s.elems;
1686 undef == null && e != null;
1687 e = e.sibling) {
1688 if (e.sym.kind == MTH &&
1689 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1690 MethodSymbol absmeth = (MethodSymbol)e.sym;
1691 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1692 if (implmeth == null || implmeth == absmeth)
1693 undef = absmeth;
1694 }
1695 }
1696 if (undef == null) {
1697 Type st = types.supertype(c.type);
1698 if (st.tag == CLASS)
1699 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1700 }
1701 for (List<Type> l = types.interfaces(c.type);
1702 undef == null && l.nonEmpty();
1703 l = l.tail) {
1704 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1705 }
1706 }
1707 return undef;
1708 }
1710 /** Check for cyclic references. Issue an error if the
1711 * symbol of the type referred to has a LOCKED flag set.
1712 *
1713 * @param pos Position to be used for error reporting.
1714 * @param t The type referred to.
1715 */
1716 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1717 checkNonCyclicInternal(pos, t);
1718 }
1721 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1722 checkNonCyclic1(pos, t, List.<TypeVar>nil());
1723 }
1725 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
1726 final TypeVar tv;
1727 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1728 return;
1729 if (seen.contains(t)) {
1730 tv = (TypeVar)t;
1731 tv.bound = types.createErrorType(t);
1732 log.error(pos, "cyclic.inheritance", t);
1733 } else if (t.tag == TYPEVAR) {
1734 tv = (TypeVar)t;
1735 seen = seen.prepend(tv);
1736 for (Type b : types.getBounds(tv))
1737 checkNonCyclic1(pos, b, seen);
1738 }
1739 }
1741 /** Check for cyclic references. Issue an error if the
1742 * symbol of the type referred to has a LOCKED flag set.
1743 *
1744 * @param pos Position to be used for error reporting.
1745 * @param t The type referred to.
1746 * @returns True if the check completed on all attributed classes
1747 */
1748 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1749 boolean complete = true; // was the check complete?
1750 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1751 Symbol c = t.tsym;
1752 if ((c.flags_field & ACYCLIC) != 0) return true;
1754 if ((c.flags_field & LOCKED) != 0) {
1755 noteCyclic(pos, (ClassSymbol)c);
1756 } else if (!c.type.isErroneous()) {
1757 try {
1758 c.flags_field |= LOCKED;
1759 if (c.type.tag == CLASS) {
1760 ClassType clazz = (ClassType)c.type;
1761 if (clazz.interfaces_field != null)
1762 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1763 complete &= checkNonCyclicInternal(pos, l.head);
1764 if (clazz.supertype_field != null) {
1765 Type st = clazz.supertype_field;
1766 if (st != null && st.tag == CLASS)
1767 complete &= checkNonCyclicInternal(pos, st);
1768 }
1769 if (c.owner.kind == TYP)
1770 complete &= checkNonCyclicInternal(pos, c.owner.type);
1771 }
1772 } finally {
1773 c.flags_field &= ~LOCKED;
1774 }
1775 }
1776 if (complete)
1777 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1778 if (complete) c.flags_field |= ACYCLIC;
1779 return complete;
1780 }
1782 /** Note that we found an inheritance cycle. */
1783 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1784 log.error(pos, "cyclic.inheritance", c);
1785 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1786 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
1787 Type st = types.supertype(c.type);
1788 if (st.tag == CLASS)
1789 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
1790 c.type = types.createErrorType(c, c.type);
1791 c.flags_field |= ACYCLIC;
1792 }
1794 /** Check that all methods which implement some
1795 * method conform to the method they implement.
1796 * @param tree The class definition whose members are checked.
1797 */
1798 void checkImplementations(JCClassDecl tree) {
1799 checkImplementations(tree, tree.sym);
1800 }
1801 //where
1802 /** Check that all methods which implement some
1803 * method in `ic' conform to the method they implement.
1804 */
1805 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
1806 ClassSymbol origin = tree.sym;
1807 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
1808 ClassSymbol lc = (ClassSymbol)l.head.tsym;
1809 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
1810 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
1811 if (e.sym.kind == MTH &&
1812 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
1813 MethodSymbol absmeth = (MethodSymbol)e.sym;
1814 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
1815 if (implmeth != null && implmeth != absmeth &&
1816 (implmeth.owner.flags() & INTERFACE) ==
1817 (origin.flags() & INTERFACE)) {
1818 // don't check if implmeth is in a class, yet
1819 // origin is an interface. This case arises only
1820 // if implmeth is declared in Object. The reason is
1821 // that interfaces really don't inherit from
1822 // Object it's just that the compiler represents
1823 // things that way.
1824 checkOverride(tree, implmeth, absmeth, origin);
1825 }
1826 }
1827 }
1828 }
1829 }
1830 }
1832 /** Check that all abstract methods implemented by a class are
1833 * mutually compatible.
1834 * @param pos Position to be used for error reporting.
1835 * @param c The class whose interfaces are checked.
1836 */
1837 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
1838 List<Type> supertypes = types.interfaces(c);
1839 Type supertype = types.supertype(c);
1840 if (supertype.tag == CLASS &&
1841 (supertype.tsym.flags() & ABSTRACT) != 0)
1842 supertypes = supertypes.prepend(supertype);
1843 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
1844 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
1845 !checkCompatibleAbstracts(pos, l.head, l.head, c))
1846 return;
1847 for (List<Type> m = supertypes; m != l; m = m.tail)
1848 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
1849 return;
1850 }
1851 checkCompatibleConcretes(pos, c);
1852 }
1854 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
1855 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
1856 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
1857 // VM allows methods and variables with differing types
1858 if (sym.kind == e.sym.kind &&
1859 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
1860 sym != e.sym &&
1861 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
1862 (sym.flags() & IPROXY) == 0 && (e.sym.flags() & IPROXY) == 0 &&
1863 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
1864 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
1865 return;
1866 }
1867 }
1868 }
1869 }
1871 /** Report a conflict between a user symbol and a synthetic symbol.
1872 */
1873 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
1874 if (!sym.type.isErroneous()) {
1875 if (warnOnSyntheticConflicts) {
1876 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
1877 }
1878 else {
1879 log.error(pos, "synthetic.name.conflict", sym, sym.location());
1880 }
1881 }
1882 }
1884 /** Check that class c does not implement directly or indirectly
1885 * the same parameterized interface with two different argument lists.
1886 * @param pos Position to be used for error reporting.
1887 * @param type The type whose interfaces are checked.
1888 */
1889 void checkClassBounds(DiagnosticPosition pos, Type type) {
1890 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
1891 }
1892 //where
1893 /** Enter all interfaces of type `type' into the hash table `seensofar'
1894 * with their class symbol as key and their type as value. Make
1895 * sure no class is entered with two different types.
1896 */
1897 void checkClassBounds(DiagnosticPosition pos,
1898 Map<TypeSymbol,Type> seensofar,
1899 Type type) {
1900 if (type.isErroneous()) return;
1901 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
1902 Type it = l.head;
1903 Type oldit = seensofar.put(it.tsym, it);
1904 if (oldit != null) {
1905 List<Type> oldparams = oldit.allparams();
1906 List<Type> newparams = it.allparams();
1907 if (!types.containsTypeEquivalent(oldparams, newparams))
1908 log.error(pos, "cant.inherit.diff.arg",
1909 it.tsym, Type.toString(oldparams),
1910 Type.toString(newparams));
1911 }
1912 checkClassBounds(pos, seensofar, it);
1913 }
1914 Type st = types.supertype(type);
1915 if (st != null) checkClassBounds(pos, seensofar, st);
1916 }
1918 /** Enter interface into into set.
1919 * If it existed already, issue a "repeated interface" error.
1920 */
1921 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
1922 if (its.contains(it))
1923 log.error(pos, "repeated.interface");
1924 else {
1925 its.add(it);
1926 }
1927 }
1929 /* *************************************************************************
1930 * Check annotations
1931 **************************************************************************/
1933 /**
1934 * Recursively validate annotations values
1935 */
1936 void validateAnnotationTree(JCTree tree) {
1937 class AnnotationValidator extends TreeScanner {
1938 @Override
1939 public void visitAnnotation(JCAnnotation tree) {
1940 super.visitAnnotation(tree);
1941 validateAnnotation(tree);
1942 }
1943 }
1944 tree.accept(new AnnotationValidator());
1945 }
1947 /** Annotation types are restricted to primitives, String, an
1948 * enum, an annotation, Class, Class<?>, Class<? extends
1949 * Anything>, arrays of the preceding.
1950 */
1951 void validateAnnotationType(JCTree restype) {
1952 // restype may be null if an error occurred, so don't bother validating it
1953 if (restype != null) {
1954 validateAnnotationType(restype.pos(), restype.type);
1955 }
1956 }
1958 void validateAnnotationType(DiagnosticPosition pos, Type type) {
1959 if (type.isPrimitive()) return;
1960 if (types.isSameType(type, syms.stringType)) return;
1961 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
1962 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
1963 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
1964 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
1965 validateAnnotationType(pos, types.elemtype(type));
1966 return;
1967 }
1968 log.error(pos, "invalid.annotation.member.type");
1969 }
1971 /**
1972 * "It is also a compile-time error if any method declared in an
1973 * annotation type has a signature that is override-equivalent to
1974 * that of any public or protected method declared in class Object
1975 * or in the interface annotation.Annotation."
1976 *
1977 * @jls3 9.6 Annotation Types
1978 */
1979 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
1980 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
1981 Scope s = sup.tsym.members();
1982 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
1983 if (e.sym.kind == MTH &&
1984 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
1985 types.overrideEquivalent(m.type, e.sym.type))
1986 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
1987 }
1988 }
1989 }
1991 /** Check the annotations of a symbol.
1992 */
1993 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
1994 if (skipAnnotations) return;
1995 for (JCAnnotation a : annotations)
1996 validateAnnotation(a, s);
1997 }
1999 /** Check the type annotations
2000 */
2001 public void validateTypeAnnotations(List<JCTypeAnnotation> annotations, boolean isTypeParameter) {
2002 if (skipAnnotations) return;
2003 for (JCTypeAnnotation a : annotations)
2004 validateTypeAnnotation(a, isTypeParameter);
2005 }
2007 /** Check an annotation of a symbol.
2008 */
2009 public void validateAnnotation(JCAnnotation a, Symbol s) {
2010 validateAnnotationTree(a);
2012 if (!annotationApplicable(a, s))
2013 log.error(a.pos(), "annotation.type.not.applicable");
2015 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2016 if (!isOverrider(s))
2017 log.error(a.pos(), "method.does.not.override.superclass");
2018 }
2019 }
2021 public void validateTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
2022 if (a.type == null)
2023 throw new AssertionError("annotation tree hasn't been attributed yet: " + a);
2024 validateAnnotationTree(a);
2026 if (!isTypeAnnotation(a, isTypeParameter))
2027 log.error(a.pos(), "annotation.type.not.applicable");
2028 }
2030 /** Is s a method symbol that overrides a method in a superclass? */
2031 boolean isOverrider(Symbol s) {
2032 if (s.kind != MTH || s.isStatic())
2033 return false;
2034 MethodSymbol m = (MethodSymbol)s;
2035 TypeSymbol owner = (TypeSymbol)m.owner;
2036 for (Type sup : types.closure(owner.type)) {
2037 if (sup == owner.type)
2038 continue; // skip "this"
2039 Scope scope = sup.tsym.members();
2040 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
2041 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
2042 return true;
2043 }
2044 }
2045 return false;
2046 }
2048 /** Is the annotation applicable to type annotations */
2049 boolean isTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
2050 Attribute.Compound atTarget =
2051 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2052 if (atTarget == null) return true;
2053 Attribute atValue = atTarget.member(names.value);
2054 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2055 Attribute.Array arr = (Attribute.Array) atValue;
2056 for (Attribute app : arr.values) {
2057 if (!(app instanceof Attribute.Enum)) return true; // recovery
2058 Attribute.Enum e = (Attribute.Enum) app;
2059 if (!isTypeParameter && e.value.name == names.TYPE_USE)
2060 return true;
2061 else if (isTypeParameter && e.value.name == names.TYPE_PARAMETER)
2062 return true;
2063 }
2064 return false;
2065 }
2067 /** Is the annotation applicable to the symbol? */
2068 boolean annotationApplicable(JCAnnotation a, Symbol s) {
2069 Attribute.Compound atTarget =
2070 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2071 if (atTarget == null) return true;
2072 Attribute atValue = atTarget.member(names.value);
2073 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2074 Attribute.Array arr = (Attribute.Array) atValue;
2075 for (Attribute app : arr.values) {
2076 if (!(app instanceof Attribute.Enum)) return true; // recovery
2077 Attribute.Enum e = (Attribute.Enum) app;
2078 if (e.value.name == names.TYPE)
2079 { if (s.kind == TYP) return true; }
2080 else if (e.value.name == names.FIELD)
2081 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
2082 else if (e.value.name == names.METHOD)
2083 { if (s.kind == MTH && !s.isConstructor()) return true; }
2084 else if (e.value.name == names.PARAMETER)
2085 { if (s.kind == VAR &&
2086 s.owner.kind == MTH &&
2087 (s.flags() & PARAMETER) != 0)
2088 return true;
2089 }
2090 else if (e.value.name == names.CONSTRUCTOR)
2091 { if (s.kind == MTH && s.isConstructor()) return true; }
2092 else if (e.value.name == names.LOCAL_VARIABLE)
2093 { if (s.kind == VAR && s.owner.kind == MTH &&
2094 (s.flags() & PARAMETER) == 0)
2095 return true;
2096 }
2097 else if (e.value.name == names.ANNOTATION_TYPE)
2098 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
2099 return true;
2100 }
2101 else if (e.value.name == names.PACKAGE)
2102 { if (s.kind == PCK) return true; }
2103 else if (e.value.name == names.TYPE_USE)
2104 { if (s.kind == TYP ||
2105 s.kind == VAR ||
2106 (s.kind == MTH && !s.isConstructor() &&
2107 s.type.getReturnType().tag != VOID))
2108 return true;
2109 }
2110 else
2111 return true; // recovery
2112 }
2113 return false;
2114 }
2116 /** Check an annotation value.
2117 */
2118 public void validateAnnotation(JCAnnotation a) {
2119 if (a.type.isErroneous()) return;
2121 // collect an inventory of the members (sorted alphabetically)
2122 Set<MethodSymbol> members = new TreeSet<MethodSymbol>(new Comparator<Symbol>() {
2123 public int compare(Symbol t, Symbol t1) {
2124 return t.name.compareTo(t1.name);
2125 }
2126 });
2127 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
2128 e != null;
2129 e = e.sibling)
2130 if (e.sym.kind == MTH)
2131 members.add((MethodSymbol) e.sym);
2133 // count them off as they're annotated
2134 for (JCTree arg : a.args) {
2135 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
2136 JCAssign assign = (JCAssign) arg;
2137 Symbol m = TreeInfo.symbol(assign.lhs);
2138 if (m == null || m.type.isErroneous()) continue;
2139 if (!members.remove(m))
2140 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
2141 m.name, a.type);
2142 }
2144 // all the remaining ones better have default values
2145 ListBuffer<Name> missingDefaults = ListBuffer.lb();
2146 for (MethodSymbol m : members) {
2147 if (m.defaultValue == null && !m.type.isErroneous()) {
2148 missingDefaults.append(m.name);
2149 }
2150 }
2151 if (missingDefaults.nonEmpty()) {
2152 String key = (missingDefaults.size() > 1)
2153 ? "annotation.missing.default.value.1"
2154 : "annotation.missing.default.value";
2155 log.error(a.pos(), key, a.type, missingDefaults);
2156 }
2158 // special case: java.lang.annotation.Target must not have
2159 // repeated values in its value member
2160 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
2161 a.args.tail == null)
2162 return;
2164 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
2165 JCAssign assign = (JCAssign) a.args.head;
2166 Symbol m = TreeInfo.symbol(assign.lhs);
2167 if (m.name != names.value) return;
2168 JCTree rhs = assign.rhs;
2169 if (rhs.getTag() != JCTree.NEWARRAY) return;
2170 JCNewArray na = (JCNewArray) rhs;
2171 Set<Symbol> targets = new HashSet<Symbol>();
2172 for (JCTree elem : na.elems) {
2173 if (!targets.add(TreeInfo.symbol(elem))) {
2174 log.error(elem.pos(), "repeated.annotation.target");
2175 }
2176 }
2177 }
2179 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
2180 if (allowAnnotations &&
2181 lint.isEnabled(Lint.LintCategory.DEP_ANN) &&
2182 (s.flags() & DEPRECATED) != 0 &&
2183 !syms.deprecatedType.isErroneous() &&
2184 s.attribute(syms.deprecatedType.tsym) == null) {
2185 log.warning(Lint.LintCategory.DEP_ANN,
2186 pos, "missing.deprecated.annotation");
2187 }
2188 }
2190 /* *************************************************************************
2191 * Check for recursive annotation elements.
2192 **************************************************************************/
2194 /** Check for cycles in the graph of annotation elements.
2195 */
2196 void checkNonCyclicElements(JCClassDecl tree) {
2197 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
2198 assert (tree.sym.flags_field & LOCKED) == 0;
2199 try {
2200 tree.sym.flags_field |= LOCKED;
2201 for (JCTree def : tree.defs) {
2202 if (def.getTag() != JCTree.METHODDEF) continue;
2203 JCMethodDecl meth = (JCMethodDecl)def;
2204 checkAnnotationResType(meth.pos(), meth.restype.type);
2205 }
2206 } finally {
2207 tree.sym.flags_field &= ~LOCKED;
2208 tree.sym.flags_field |= ACYCLIC_ANN;
2209 }
2210 }
2212 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
2213 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
2214 return;
2215 if ((tsym.flags_field & LOCKED) != 0) {
2216 log.error(pos, "cyclic.annotation.element");
2217 return;
2218 }
2219 try {
2220 tsym.flags_field |= LOCKED;
2221 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
2222 Symbol s = e.sym;
2223 if (s.kind != Kinds.MTH)
2224 continue;
2225 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
2226 }
2227 } finally {
2228 tsym.flags_field &= ~LOCKED;
2229 tsym.flags_field |= ACYCLIC_ANN;
2230 }
2231 }
2233 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
2234 switch (type.tag) {
2235 case TypeTags.CLASS:
2236 if ((type.tsym.flags() & ANNOTATION) != 0)
2237 checkNonCyclicElementsInternal(pos, type.tsym);
2238 break;
2239 case TypeTags.ARRAY:
2240 checkAnnotationResType(pos, types.elemtype(type));
2241 break;
2242 default:
2243 break; // int etc
2244 }
2245 }
2247 /* *************************************************************************
2248 * Check for cycles in the constructor call graph.
2249 **************************************************************************/
2251 /** Check for cycles in the graph of constructors calling other
2252 * constructors.
2253 */
2254 void checkCyclicConstructors(JCClassDecl tree) {
2255 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
2257 // enter each constructor this-call into the map
2258 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2259 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
2260 if (app == null) continue;
2261 JCMethodDecl meth = (JCMethodDecl) l.head;
2262 if (TreeInfo.name(app.meth) == names._this) {
2263 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
2264 } else {
2265 meth.sym.flags_field |= ACYCLIC;
2266 }
2267 }
2269 // Check for cycles in the map
2270 Symbol[] ctors = new Symbol[0];
2271 ctors = callMap.keySet().toArray(ctors);
2272 for (Symbol caller : ctors) {
2273 checkCyclicConstructor(tree, caller, callMap);
2274 }
2275 }
2277 /** Look in the map to see if the given constructor is part of a
2278 * call cycle.
2279 */
2280 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2281 Map<Symbol,Symbol> callMap) {
2282 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2283 if ((ctor.flags_field & LOCKED) != 0) {
2284 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2285 "recursive.ctor.invocation");
2286 } else {
2287 ctor.flags_field |= LOCKED;
2288 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2289 ctor.flags_field &= ~LOCKED;
2290 }
2291 ctor.flags_field |= ACYCLIC;
2292 }
2293 }
2295 /* *************************************************************************
2296 * Miscellaneous
2297 **************************************************************************/
2299 /**
2300 * Return the opcode of the operator but emit an error if it is an
2301 * error.
2302 * @param pos position for error reporting.
2303 * @param operator an operator
2304 * @param tag a tree tag
2305 * @param left type of left hand side
2306 * @param right type of right hand side
2307 */
2308 int checkOperator(DiagnosticPosition pos,
2309 OperatorSymbol operator,
2310 int tag,
2311 Type left,
2312 Type right) {
2313 if (operator.opcode == ByteCodes.error) {
2314 log.error(pos,
2315 "operator.cant.be.applied",
2316 treeinfo.operatorName(tag),
2317 List.of(left, right));
2318 }
2319 return operator.opcode;
2320 }
2323 /**
2324 * Check for division by integer constant zero
2325 * @param pos Position for error reporting.
2326 * @param operator The operator for the expression
2327 * @param operand The right hand operand for the expression
2328 */
2329 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2330 if (operand.constValue() != null
2331 && lint.isEnabled(Lint.LintCategory.DIVZERO)
2332 && operand.tag <= LONG
2333 && ((Number) (operand.constValue())).longValue() == 0) {
2334 int opc = ((OperatorSymbol)operator).opcode;
2335 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2336 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2337 log.warning(Lint.LintCategory.DIVZERO, pos, "div.zero");
2338 }
2339 }
2340 }
2342 /**
2343 * Check for empty statements after if
2344 */
2345 void checkEmptyIf(JCIf tree) {
2346 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(Lint.LintCategory.EMPTY))
2347 log.warning(Lint.LintCategory.EMPTY, tree.thenpart.pos(), "empty.if");
2348 }
2350 /** Check that symbol is unique in given scope.
2351 * @param pos Position for error reporting.
2352 * @param sym The symbol.
2353 * @param s The scope.
2354 */
2355 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2356 if (sym.type.isErroneous())
2357 return true;
2358 if (sym.owner.name == names.any) return false;
2359 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2360 if (sym != e.sym &&
2361 sym.kind == e.sym.kind &&
2362 sym.name != names.error &&
2363 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
2364 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
2365 varargsDuplicateError(pos, sym, e.sym);
2366 else if (sym.kind == MTH && !types.overrideEquivalent(sym.type, e.sym.type))
2367 duplicateErasureError(pos, sym, e.sym);
2368 else
2369 duplicateError(pos, e.sym);
2370 return false;
2371 }
2372 }
2373 return true;
2374 }
2375 //where
2376 /** Report duplicate declaration error.
2377 */
2378 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
2379 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
2380 log.error(pos, "name.clash.same.erasure", sym1, sym2);
2381 }
2382 }
2384 /** Check that single-type import is not already imported or top-level defined,
2385 * but make an exception for two single-type imports which denote the same type.
2386 * @param pos Position for error reporting.
2387 * @param sym The symbol.
2388 * @param s The scope
2389 */
2390 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2391 return checkUniqueImport(pos, sym, s, false);
2392 }
2394 /** Check that static single-type import is not already imported or top-level defined,
2395 * but make an exception for two single-type imports which denote the same type.
2396 * @param pos Position for error reporting.
2397 * @param sym The symbol.
2398 * @param s The scope
2399 * @param staticImport Whether or not this was a static import
2400 */
2401 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2402 return checkUniqueImport(pos, sym, s, true);
2403 }
2405 /** Check that single-type import is not already imported or top-level defined,
2406 * but make an exception for two single-type imports which denote the same type.
2407 * @param pos Position for error reporting.
2408 * @param sym The symbol.
2409 * @param s The scope.
2410 * @param staticImport Whether or not this was a static import
2411 */
2412 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2413 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2414 // is encountered class entered via a class declaration?
2415 boolean isClassDecl = e.scope == s;
2416 if ((isClassDecl || sym != e.sym) &&
2417 sym.kind == e.sym.kind &&
2418 sym.name != names.error) {
2419 if (!e.sym.type.isErroneous()) {
2420 String what = e.sym.toString();
2421 if (!isClassDecl) {
2422 if (staticImport)
2423 log.error(pos, "already.defined.static.single.import", what);
2424 else
2425 log.error(pos, "already.defined.single.import", what);
2426 }
2427 else if (sym != e.sym)
2428 log.error(pos, "already.defined.this.unit", what);
2429 }
2430 return false;
2431 }
2432 }
2433 return true;
2434 }
2436 /** Check that a qualified name is in canonical form (for import decls).
2437 */
2438 public void checkCanonical(JCTree tree) {
2439 if (!isCanonical(tree))
2440 log.error(tree.pos(), "import.requires.canonical",
2441 TreeInfo.symbol(tree));
2442 }
2443 // where
2444 private boolean isCanonical(JCTree tree) {
2445 while (tree.getTag() == JCTree.SELECT) {
2446 JCFieldAccess s = (JCFieldAccess) tree;
2447 if (s.sym.owner != TreeInfo.symbol(s.selected))
2448 return false;
2449 tree = s.selected;
2450 }
2451 return true;
2452 }
2454 private class ConversionWarner extends Warner {
2455 final String key;
2456 final Type found;
2457 final Type expected;
2458 public ConversionWarner(DiagnosticPosition pos, String key, Type found, Type expected) {
2459 super(pos);
2460 this.key = key;
2461 this.found = found;
2462 this.expected = expected;
2463 }
2465 @Override
2466 public void warnUnchecked() {
2467 boolean warned = this.warned;
2468 super.warnUnchecked();
2469 if (warned) return; // suppress redundant diagnostics
2470 Object problem = diags.fragment(key);
2471 Check.this.warnUnchecked(pos(), "prob.found.req", problem, found, expected);
2472 }
2473 }
2475 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2476 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2477 }
2479 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2480 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2481 }
2482 }
