Mercurial > jdk8-mips64-public > langtools / file revision
src/share/classes/com/sun/tools/javac/comp/Check.java@87eb6edd4f21
src/share/classes/com/sun/tools/javac/comp/Check.java
Thu, 25 Feb 2010 09:42:35 -0800
- author
- jjg
- date
- Thu, 25 Feb 2010 09:42:35 -0800
- changeset 505
- 87eb6edd4f21
- parent 479
- da0e3e2dd3ef
- child 536
- 396b117c1743
- permissions
- -rw-r--r--
4880220: Add a warning when accessing a static method via an reference
Reviewed-by: darcy
1 /*
2 * Copyright 1999-2009 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
26 package com.sun.tools.javac.comp;
28 import java.util.*;
29 import java.util.Set;
31 import com.sun.tools.javac.code.*;
32 import com.sun.tools.javac.jvm.*;
33 import com.sun.tools.javac.tree.*;
34 import com.sun.tools.javac.util.*;
35 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
36 import com.sun.tools.javac.util.List;
38 import com.sun.tools.javac.tree.JCTree.*;
39 import com.sun.tools.javac.code.Lint;
40 import com.sun.tools.javac.code.Lint.LintCategory;
41 import com.sun.tools.javac.code.Type.*;
42 import com.sun.tools.javac.code.Symbol.*;
44 import static com.sun.tools.javac.code.Flags.*;
45 import static com.sun.tools.javac.code.Kinds.*;
46 import static com.sun.tools.javac.code.TypeTags.*;
48 /** Type checking helper class for the attribution phase.
49 *
50 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
51 * you write code that depends on this, you do so at your own risk.
52 * This code and its internal interfaces are subject to change or
53 * deletion without notice.</b>
54 */
55 public class Check {
56 protected static final Context.Key<Check> checkKey =
57 new Context.Key<Check>();
59 private final Names names;
60 private final Log log;
61 private final Symtab syms;
62 private final Infer infer;
63 private final Types types;
64 private final JCDiagnostic.Factory diags;
65 private final boolean skipAnnotations;
66 private boolean warnOnSyntheticConflicts;
67 private final TreeInfo treeinfo;
69 // The set of lint options currently in effect. It is initialized
70 // from the context, and then is set/reset as needed by Attr as it
71 // visits all the various parts of the trees during attribution.
72 private Lint lint;
74 public static Check instance(Context context) {
75 Check instance = context.get(checkKey);
76 if (instance == null)
77 instance = new Check(context);
78 return instance;
79 }
81 protected Check(Context context) {
82 context.put(checkKey, this);
84 names = Names.instance(context);
85 log = Log.instance(context);
86 syms = Symtab.instance(context);
87 infer = Infer.instance(context);
88 this.types = Types.instance(context);
89 diags = JCDiagnostic.Factory.instance(context);
90 Options options = Options.instance(context);
91 lint = Lint.instance(context);
92 treeinfo = TreeInfo.instance(context);
94 Source source = Source.instance(context);
95 allowGenerics = source.allowGenerics();
96 allowAnnotations = source.allowAnnotations();
97 allowCovariantReturns = source.allowCovariantReturns();
98 complexInference = options.get("-complexinference") != null;
99 skipAnnotations = options.get("skipAnnotations") != null;
100 warnOnSyntheticConflicts = options.get("warnOnSyntheticConflicts") != null;
102 Target target = Target.instance(context);
103 syntheticNameChar = target.syntheticNameChar();
105 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
106 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
107 boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
108 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
110 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
111 enforceMandatoryWarnings, "deprecated");
112 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
113 enforceMandatoryWarnings, "unchecked");
114 sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
115 enforceMandatoryWarnings, "sunapi");
116 }
118 /** Switch: generics enabled?
119 */
120 boolean allowGenerics;
122 /** Switch: annotations enabled?
123 */
124 boolean allowAnnotations;
126 /** Switch: covariant returns enabled?
127 */
128 boolean allowCovariantReturns;
130 /** Switch: -complexinference option set?
131 */
132 boolean complexInference;
134 /** Character for synthetic names
135 */
136 char syntheticNameChar;
138 /** A table mapping flat names of all compiled classes in this run to their
139 * symbols; maintained from outside.
140 */
141 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
143 /** A handler for messages about deprecated usage.
144 */
145 private MandatoryWarningHandler deprecationHandler;
147 /** A handler for messages about unchecked or unsafe usage.
148 */
149 private MandatoryWarningHandler uncheckedHandler;
151 /** A handler for messages about using Sun proprietary API.
152 */
153 private MandatoryWarningHandler sunApiHandler;
155 /* *************************************************************************
156 * Errors and Warnings
157 **************************************************************************/
159 Lint setLint(Lint newLint) {
160 Lint prev = lint;
161 lint = newLint;
162 return prev;
163 }
165 /** Warn about deprecated symbol.
166 * @param pos Position to be used for error reporting.
167 * @param sym The deprecated symbol.
168 */
169 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
170 if (!lint.isSuppressed(LintCategory.DEPRECATION))
171 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
172 }
174 /** Warn about unchecked operation.
175 * @param pos Position to be used for error reporting.
176 * @param msg A string describing the problem.
177 */
178 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
179 if (!lint.isSuppressed(LintCategory.UNCHECKED))
180 uncheckedHandler.report(pos, msg, args);
181 }
183 /** Warn about using Sun proprietary API.
184 * @param pos Position to be used for error reporting.
185 * @param msg A string describing the problem.
186 */
187 public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
188 if (!lint.isSuppressed(LintCategory.SUNAPI))
189 sunApiHandler.report(pos, msg, args);
190 }
192 public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
193 if (lint.isEnabled(LintCategory.STATIC))
194 log.warning(pos, msg, args);
195 }
197 /**
198 * Report any deferred diagnostics.
199 */
200 public void reportDeferredDiagnostics() {
201 deprecationHandler.reportDeferredDiagnostic();
202 uncheckedHandler.reportDeferredDiagnostic();
203 sunApiHandler.reportDeferredDiagnostic();
204 }
207 /** Report a failure to complete a class.
208 * @param pos Position to be used for error reporting.
209 * @param ex The failure to report.
210 */
211 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
212 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
213 if (ex instanceof ClassReader.BadClassFile) throw new Abort();
214 else return syms.errType;
215 }
217 /** Report a type error.
218 * @param pos Position to be used for error reporting.
219 * @param problem A string describing the error.
220 * @param found The type that was found.
221 * @param req The type that was required.
222 */
223 Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
224 log.error(pos, "prob.found.req",
225 problem, found, req);
226 return types.createErrorType(found);
227 }
229 Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
230 log.error(pos, "prob.found.req.1", problem, found, req, explanation);
231 return types.createErrorType(found);
232 }
234 /** Report an error that wrong type tag was found.
235 * @param pos Position to be used for error reporting.
236 * @param required An internationalized string describing the type tag
237 * required.
238 * @param found The type that was found.
239 */
240 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
241 // this error used to be raised by the parser,
242 // but has been delayed to this point:
243 if (found instanceof Type && ((Type)found).tag == VOID) {
244 log.error(pos, "illegal.start.of.type");
245 return syms.errType;
246 }
247 log.error(pos, "type.found.req", found, required);
248 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
249 }
251 /** Report an error that symbol cannot be referenced before super
252 * has been called.
253 * @param pos Position to be used for error reporting.
254 * @param sym The referenced symbol.
255 */
256 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
257 log.error(pos, "cant.ref.before.ctor.called", sym);
258 }
260 /** Report duplicate declaration error.
261 */
262 void duplicateError(DiagnosticPosition pos, Symbol sym) {
263 if (!sym.type.isErroneous()) {
264 log.error(pos, "already.defined", sym, sym.location());
265 }
266 }
268 /** Report array/varargs duplicate declaration
269 */
270 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
271 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
272 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
273 }
274 }
276 /* ************************************************************************
277 * duplicate declaration checking
278 *************************************************************************/
280 /** Check that variable does not hide variable with same name in
281 * immediately enclosing local scope.
282 * @param pos Position for error reporting.
283 * @param v The symbol.
284 * @param s The scope.
285 */
286 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
287 if (s.next != null) {
288 for (Scope.Entry e = s.next.lookup(v.name);
289 e.scope != null && e.sym.owner == v.owner;
290 e = e.next()) {
291 if (e.sym.kind == VAR &&
292 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
293 v.name != names.error) {
294 duplicateError(pos, e.sym);
295 return;
296 }
297 }
298 }
299 }
301 /** Check that a class or interface does not hide a class or
302 * interface with same name in immediately enclosing local scope.
303 * @param pos Position for error reporting.
304 * @param c The symbol.
305 * @param s The scope.
306 */
307 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
308 if (s.next != null) {
309 for (Scope.Entry e = s.next.lookup(c.name);
310 e.scope != null && e.sym.owner == c.owner;
311 e = e.next()) {
312 if (e.sym.kind == TYP &&
313 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
314 c.name != names.error) {
315 duplicateError(pos, e.sym);
316 return;
317 }
318 }
319 }
320 }
322 /** Check that class does not have the same name as one of
323 * its enclosing classes, or as a class defined in its enclosing scope.
324 * return true if class is unique in its enclosing scope.
325 * @param pos Position for error reporting.
326 * @param name The class name.
327 * @param s The enclosing scope.
328 */
329 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
330 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
331 if (e.sym.kind == TYP && e.sym.name != names.error) {
332 duplicateError(pos, e.sym);
333 return false;
334 }
335 }
336 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
337 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
338 duplicateError(pos, sym);
339 return true;
340 }
341 }
342 return true;
343 }
345 /* *************************************************************************
346 * Class name generation
347 **************************************************************************/
349 /** Return name of local class.
350 * This is of the form <enclClass> $ n <classname>
351 * where
352 * enclClass is the flat name of the enclosing class,
353 * classname is the simple name of the local class
354 */
355 Name localClassName(ClassSymbol c) {
356 for (int i=1; ; i++) {
357 Name flatname = names.
358 fromString("" + c.owner.enclClass().flatname +
359 syntheticNameChar + i +
360 c.name);
361 if (compiled.get(flatname) == null) return flatname;
362 }
363 }
365 /* *************************************************************************
366 * Type Checking
367 **************************************************************************/
369 /** Check that a given type is assignable to a given proto-type.
370 * If it is, return the type, otherwise return errType.
371 * @param pos Position to be used for error reporting.
372 * @param found The type that was found.
373 * @param req The type that was required.
374 */
375 Type checkType(DiagnosticPosition pos, Type found, Type req) {
376 if (req.tag == ERROR)
377 return req;
378 if (req.tag == NONE)
379 return found;
380 if (types.isAssignable(found, req, convertWarner(pos, found, req)))
381 return found;
382 if (found.tag <= DOUBLE && req.tag <= DOUBLE)
383 return typeError(pos, diags.fragment("possible.loss.of.precision"), found, req);
384 if (found.isSuperBound()) {
385 log.error(pos, "assignment.from.super-bound", found);
386 return types.createErrorType(found);
387 }
388 if (req.isExtendsBound()) {
389 log.error(pos, "assignment.to.extends-bound", req);
390 return types.createErrorType(found);
391 }
392 return typeError(pos, diags.fragment("incompatible.types"), found, req);
393 }
395 Type checkReturnType(DiagnosticPosition pos, Type found, Type req) {
396 if (found.tag == FORALL) {
397 try {
398 return instantiatePoly(pos, (ForAll) found, req, convertWarner(pos, found, req));
399 } catch (Infer.NoInstanceException ex) {
400 if (ex.isAmbiguous) {
401 JCDiagnostic d = ex.getDiagnostic();
402 log.error(pos,
403 "undetermined.type" + (d != null ? ".1" : ""),
404 found, d);
405 return types.createErrorType(req);
406 } else {
407 JCDiagnostic d = ex.getDiagnostic();
408 return typeError(pos,
409 diags.fragment("incompatible.types" + (d != null ? ".1" : ""), d),
410 found, req);
411 }
412 } catch (Infer.InvalidInstanceException ex) {
413 JCDiagnostic d = ex.getDiagnostic();
414 log.error(pos, "invalid.inferred.types", ((ForAll)found).tvars, d);
415 return types.createErrorType(req);
416 }
417 } else {
418 return checkType(pos, found, req);
419 }
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 return infer.instantiateExpr(t, pt, warn);
436 }
437 }
439 /** Check that a given type can be cast to a given target type.
440 * Return the result of the cast.
441 * @param pos Position to be used for error reporting.
442 * @param found The type that is being cast.
443 * @param req The target type of the cast.
444 */
445 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
446 if (found.tag == FORALL) {
447 instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
448 return req;
449 } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
450 return req;
451 } else {
452 return typeError(pos,
453 diags.fragment("inconvertible.types"),
454 found, req);
455 }
456 }
457 //where
458 /** Is type a type variable, or a (possibly multi-dimensional) array of
459 * type variables?
460 */
461 boolean isTypeVar(Type t) {
462 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
463 }
465 /** Check that a type is within some bounds.
466 *
467 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
468 * type argument.
469 * @param pos Position to be used for error reporting.
470 * @param a The type that should be bounded by bs.
471 * @param bs The bound.
472 */
473 private void checkExtends(DiagnosticPosition pos, Type a, TypeVar bs) {
474 if (a.isUnbound()) {
475 return;
476 } else if (a.tag != WILDCARD) {
477 a = types.upperBound(a);
478 for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
479 if (!types.isSubtype(a, l.head)) {
480 log.error(pos, "not.within.bounds", a);
481 return;
482 }
483 }
484 } else if (a.isExtendsBound()) {
485 if (!types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings))
486 log.error(pos, "not.within.bounds", a);
487 } else if (a.isSuperBound()) {
488 if (types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound()))
489 log.error(pos, "not.within.bounds", a);
490 }
491 }
493 /** Check that a type is within some bounds.
494 *
495 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
496 * type argument.
497 * @param pos Position to be used for error reporting.
498 * @param a The type that should be bounded by bs.
499 * @param bs The bound.
500 */
501 private void checkCapture(JCTypeApply tree) {
502 List<JCExpression> args = tree.getTypeArguments();
503 for (Type arg : types.capture(tree.type).getTypeArguments()) {
504 if (arg.tag == TYPEVAR && arg.getUpperBound().isErroneous()) {
505 log.error(args.head.pos, "not.within.bounds", args.head.type);
506 break;
507 }
508 args = args.tail;
509 }
510 }
512 /** Check that type is different from 'void'.
513 * @param pos Position to be used for error reporting.
514 * @param t The type to be checked.
515 */
516 Type checkNonVoid(DiagnosticPosition pos, Type t) {
517 if (t.tag == VOID) {
518 log.error(pos, "void.not.allowed.here");
519 return types.createErrorType(t);
520 } else {
521 return t;
522 }
523 }
525 /** Check that type is a class or interface type.
526 * @param pos Position to be used for error reporting.
527 * @param t The type to be checked.
528 */
529 Type checkClassType(DiagnosticPosition pos, Type t) {
530 if (t.tag != CLASS && t.tag != ERROR)
531 return typeTagError(pos,
532 diags.fragment("type.req.class"),
533 (t.tag == TYPEVAR)
534 ? diags.fragment("type.parameter", t)
535 : t);
536 else
537 return t;
538 }
540 /** Check that type is a class or interface type.
541 * @param pos Position to be used for error reporting.
542 * @param t The type to be checked.
543 * @param noBounds True if type bounds are illegal here.
544 */
545 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
546 t = checkClassType(pos, t);
547 if (noBounds && t.isParameterized()) {
548 List<Type> args = t.getTypeArguments();
549 while (args.nonEmpty()) {
550 if (args.head.tag == WILDCARD)
551 return typeTagError(pos,
552 Log.getLocalizedString("type.req.exact"),
553 args.head);
554 args = args.tail;
555 }
556 }
557 return t;
558 }
560 /** Check that type is a valid type for a new expression. If the type contains
561 * some uninferred type variables, instantiate them exploiting the expected
562 * type.
563 *
564 * @param pos Position to be used for error reporting.
565 * @param t The type to be checked.
566 * @param noBounds True if type bounds are illegal here.
567 * @param pt Expected type (used with diamond operator)
568 */
569 Type checkNewClassType(DiagnosticPosition pos, Type t, boolean noBounds, Type pt) {
570 if (t.tag == FORALL) {
571 try {
572 t = instantiatePoly(pos, (ForAll)t, pt, Warner.noWarnings);
573 }
574 catch (Infer.NoInstanceException ex) {
575 JCDiagnostic d = ex.getDiagnostic();
576 log.error(pos, "cant.apply.diamond", t.getTypeArguments(), d);
577 return types.createErrorType(pt);
578 }
579 }
580 return checkClassType(pos, t, noBounds);
581 }
583 /** Check that type is a reifiable class, interface or array type.
584 * @param pos Position to be used for error reporting.
585 * @param t The type to be checked.
586 */
587 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
588 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
589 return typeTagError(pos,
590 diags.fragment("type.req.class.array"),
591 t);
592 } else if (!types.isReifiable(t)) {
593 log.error(pos, "illegal.generic.type.for.instof");
594 return types.createErrorType(t);
595 } else {
596 return t;
597 }
598 }
600 /** Check that type is a reference type, i.e. a class, interface or array type
601 * or a type variable.
602 * @param pos Position to be used for error reporting.
603 * @param t The type to be checked.
604 */
605 Type checkRefType(DiagnosticPosition pos, Type t) {
606 switch (t.tag) {
607 case CLASS:
608 case ARRAY:
609 case TYPEVAR:
610 case WILDCARD:
611 case ERROR:
612 return t;
613 default:
614 return typeTagError(pos,
615 diags.fragment("type.req.ref"),
616 t);
617 }
618 }
620 /** Check that each type is a reference type, i.e. a class, interface or array type
621 * or a type variable.
622 * @param trees Original trees, used for error reporting.
623 * @param types The types to be checked.
624 */
625 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
626 List<JCExpression> tl = trees;
627 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
628 l.head = checkRefType(tl.head.pos(), l.head);
629 tl = tl.tail;
630 }
631 return types;
632 }
634 /** Check that type is a null or reference type.
635 * @param pos Position to be used for error reporting.
636 * @param t The type to be checked.
637 */
638 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
639 switch (t.tag) {
640 case CLASS:
641 case ARRAY:
642 case TYPEVAR:
643 case WILDCARD:
644 case BOT:
645 case ERROR:
646 return t;
647 default:
648 return typeTagError(pos,
649 diags.fragment("type.req.ref"),
650 t);
651 }
652 }
654 /** Check that flag set does not contain elements of two conflicting sets. s
655 * Return true if it doesn't.
656 * @param pos Position to be used for error reporting.
657 * @param flags The set of flags to be checked.
658 * @param set1 Conflicting flags set #1.
659 * @param set2 Conflicting flags set #2.
660 */
661 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
662 if ((flags & set1) != 0 && (flags & set2) != 0) {
663 log.error(pos,
664 "illegal.combination.of.modifiers",
665 asFlagSet(TreeInfo.firstFlag(flags & set1)),
666 asFlagSet(TreeInfo.firstFlag(flags & set2)));
667 return false;
668 } else
669 return true;
670 }
672 /** Check that given modifiers are legal for given symbol and
673 * return modifiers together with any implicit modififiers for that symbol.
674 * Warning: we can't use flags() here since this method
675 * is called during class enter, when flags() would cause a premature
676 * completion.
677 * @param pos Position to be used for error reporting.
678 * @param flags The set of modifiers given in a definition.
679 * @param sym The defined symbol.
680 */
681 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
682 long mask;
683 long implicit = 0;
684 switch (sym.kind) {
685 case VAR:
686 if (sym.owner.kind != TYP)
687 mask = LocalVarFlags;
688 else if ((sym.owner.flags_field & INTERFACE) != 0)
689 mask = implicit = InterfaceVarFlags;
690 else
691 mask = VarFlags;
692 break;
693 case MTH:
694 if (sym.name == names.init) {
695 if ((sym.owner.flags_field & ENUM) != 0) {
696 // enum constructors cannot be declared public or
697 // protected and must be implicitly or explicitly
698 // private
699 implicit = PRIVATE;
700 mask = PRIVATE;
701 } else
702 mask = ConstructorFlags;
703 } else if ((sym.owner.flags_field & INTERFACE) != 0)
704 mask = implicit = InterfaceMethodFlags;
705 else {
706 mask = MethodFlags;
707 }
708 // Imply STRICTFP if owner has STRICTFP set.
709 if (((flags|implicit) & Flags.ABSTRACT) == 0)
710 implicit |= sym.owner.flags_field & STRICTFP;
711 break;
712 case TYP:
713 if (sym.isLocal()) {
714 mask = LocalClassFlags;
715 if (sym.name.isEmpty()) { // Anonymous class
716 // Anonymous classes in static methods are themselves static;
717 // that's why we admit STATIC here.
718 mask |= STATIC;
719 // JLS: Anonymous classes are final.
720 implicit |= FINAL;
721 }
722 if ((sym.owner.flags_field & STATIC) == 0 &&
723 (flags & ENUM) != 0)
724 log.error(pos, "enums.must.be.static");
725 } else if (sym.owner.kind == TYP) {
726 mask = MemberClassFlags;
727 if (sym.owner.owner.kind == PCK ||
728 (sym.owner.flags_field & STATIC) != 0)
729 mask |= STATIC;
730 else if ((flags & ENUM) != 0)
731 log.error(pos, "enums.must.be.static");
732 // Nested interfaces and enums are always STATIC (Spec ???)
733 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
734 } else {
735 mask = ClassFlags;
736 }
737 // Interfaces are always ABSTRACT
738 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
740 if ((flags & ENUM) != 0) {
741 // enums can't be declared abstract or final
742 mask &= ~(ABSTRACT | FINAL);
743 implicit |= implicitEnumFinalFlag(tree);
744 }
745 // Imply STRICTFP if owner has STRICTFP set.
746 implicit |= sym.owner.flags_field & STRICTFP;
747 break;
748 default:
749 throw new AssertionError();
750 }
751 long illegal = flags & StandardFlags & ~mask;
752 if (illegal != 0) {
753 if ((illegal & INTERFACE) != 0) {
754 log.error(pos, "intf.not.allowed.here");
755 mask |= INTERFACE;
756 }
757 else {
758 log.error(pos,
759 "mod.not.allowed.here", asFlagSet(illegal));
760 }
761 }
762 else if ((sym.kind == TYP ||
763 // ISSUE: Disallowing abstract&private is no longer appropriate
764 // in the presence of inner classes. Should it be deleted here?
765 checkDisjoint(pos, flags,
766 ABSTRACT,
767 PRIVATE | STATIC))
768 &&
769 checkDisjoint(pos, flags,
770 ABSTRACT | INTERFACE,
771 FINAL | NATIVE | SYNCHRONIZED)
772 &&
773 checkDisjoint(pos, flags,
774 PUBLIC,
775 PRIVATE | PROTECTED)
776 &&
777 checkDisjoint(pos, flags,
778 PRIVATE,
779 PUBLIC | PROTECTED)
780 &&
781 checkDisjoint(pos, flags,
782 FINAL,
783 VOLATILE)
784 &&
785 (sym.kind == TYP ||
786 checkDisjoint(pos, flags,
787 ABSTRACT | NATIVE,
788 STRICTFP))) {
789 // skip
790 }
791 return flags & (mask | ~StandardFlags) | implicit;
792 }
795 /** Determine if this enum should be implicitly final.
796 *
797 * If the enum has no specialized enum contants, it is final.
798 *
799 * If the enum does have specialized enum contants, it is
800 * <i>not</i> final.
801 */
802 private long implicitEnumFinalFlag(JCTree tree) {
803 if (tree.getTag() != JCTree.CLASSDEF) return 0;
804 class SpecialTreeVisitor extends JCTree.Visitor {
805 boolean specialized;
806 SpecialTreeVisitor() {
807 this.specialized = false;
808 };
810 @Override
811 public void visitTree(JCTree tree) { /* no-op */ }
813 @Override
814 public void visitVarDef(JCVariableDecl tree) {
815 if ((tree.mods.flags & ENUM) != 0) {
816 if (tree.init instanceof JCNewClass &&
817 ((JCNewClass) tree.init).def != null) {
818 specialized = true;
819 }
820 }
821 }
822 }
824 SpecialTreeVisitor sts = new SpecialTreeVisitor();
825 JCClassDecl cdef = (JCClassDecl) tree;
826 for (JCTree defs: cdef.defs) {
827 defs.accept(sts);
828 if (sts.specialized) return 0;
829 }
830 return FINAL;
831 }
833 /* *************************************************************************
834 * Type Validation
835 **************************************************************************/
837 /** Validate a type expression. That is,
838 * check that all type arguments of a parametric type are within
839 * their bounds. This must be done in a second phase after type attributon
840 * since a class might have a subclass as type parameter bound. E.g:
841 *
842 * class B<A extends C> { ... }
843 * class C extends B<C> { ... }
844 *
845 * and we can't make sure that the bound is already attributed because
846 * of possible cycles.
847 */
848 private Validator validator = new Validator();
850 /** Visitor method: Validate a type expression, if it is not null, catching
851 * and reporting any completion failures.
852 */
853 void validate(JCTree tree, Env<AttrContext> env) {
854 try {
855 if (tree != null) {
856 validator.env = env;
857 tree.accept(validator);
858 checkRaw(tree, env);
859 }
860 } catch (CompletionFailure ex) {
861 completionError(tree.pos(), ex);
862 }
863 }
864 //where
865 void checkRaw(JCTree tree, Env<AttrContext> env) {
866 if (lint.isEnabled(Lint.LintCategory.RAW) &&
867 tree.type.tag == CLASS &&
868 !env.enclClass.name.isEmpty() && //anonymous or intersection
869 tree.type.isRaw()) {
870 log.warning(tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
871 }
872 }
874 /** Visitor method: Validate a list of type expressions.
875 */
876 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
877 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
878 validate(l.head, env);
879 }
881 /** A visitor class for type validation.
882 */
883 class Validator extends JCTree.Visitor {
885 @Override
886 public void visitTypeArray(JCArrayTypeTree tree) {
887 validate(tree.elemtype, env);
888 }
890 @Override
891 public void visitTypeApply(JCTypeApply tree) {
892 if (tree.type.tag == CLASS) {
893 List<Type> formals = tree.type.tsym.type.allparams();
894 List<Type> actuals = tree.type.allparams();
895 List<JCExpression> args = tree.arguments;
896 List<Type> forms = tree.type.tsym.type.getTypeArguments();
897 ListBuffer<TypeVar> tvars_buf = new ListBuffer<TypeVar>();
899 // For matching pairs of actual argument types `a' and
900 // formal type parameters with declared bound `b' ...
901 while (args.nonEmpty() && forms.nonEmpty()) {
902 validate(args.head, env);
904 // exact type arguments needs to know their
905 // bounds (for upper and lower bound
906 // calculations). So we create new TypeVars with
907 // bounds substed with actuals.
908 tvars_buf.append(types.substBound(((TypeVar)forms.head),
909 formals,
910 actuals));
912 args = args.tail;
913 forms = forms.tail;
914 }
916 args = tree.arguments;
917 List<Type> tvars_cap = types.substBounds(formals,
918 formals,
919 types.capture(tree.type).allparams());
920 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
921 // Let the actual arguments know their bound
922 args.head.type.withTypeVar((TypeVar)tvars_cap.head);
923 args = args.tail;
924 tvars_cap = tvars_cap.tail;
925 }
927 args = tree.arguments;
928 List<TypeVar> tvars = tvars_buf.toList();
930 while (args.nonEmpty() && tvars.nonEmpty()) {
931 checkExtends(args.head.pos(),
932 args.head.type,
933 tvars.head);
934 args = args.tail;
935 tvars = tvars.tail;
936 }
938 checkCapture(tree);
939 }
940 if (tree.type.tag == CLASS || tree.type.tag == FORALL) {
941 // Check that this type is either fully parameterized, or
942 // not parameterized at all.
943 if (tree.type.getEnclosingType().isRaw())
944 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
945 if (tree.clazz.getTag() == JCTree.SELECT)
946 visitSelectInternal((JCFieldAccess)tree.clazz);
947 }
948 }
950 @Override
951 public void visitTypeParameter(JCTypeParameter tree) {
952 validate(tree.bounds, env);
953 checkClassBounds(tree.pos(), tree.type);
954 }
956 @Override
957 public void visitWildcard(JCWildcard tree) {
958 if (tree.inner != null)
959 validate(tree.inner, env);
960 }
962 @Override
963 public void visitSelect(JCFieldAccess tree) {
964 if (tree.type.tag == CLASS) {
965 visitSelectInternal(tree);
967 // Check that this type is either fully parameterized, or
968 // not parameterized at all.
969 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
970 log.error(tree.pos(), "improperly.formed.type.param.missing");
971 }
972 }
973 public void visitSelectInternal(JCFieldAccess tree) {
974 if (tree.type.tsym.isStatic() &&
975 tree.selected.type.isParameterized()) {
976 // The enclosing type is not a class, so we are
977 // looking at a static member type. However, the
978 // qualifying expression is parameterized.
979 log.error(tree.pos(), "cant.select.static.class.from.param.type");
980 } else {
981 // otherwise validate the rest of the expression
982 tree.selected.accept(this);
983 }
984 }
986 @Override
987 public void visitAnnotatedType(JCAnnotatedType tree) {
988 tree.underlyingType.accept(this);
989 }
991 /** Default visitor method: do nothing.
992 */
993 @Override
994 public void visitTree(JCTree tree) {
995 }
997 Env<AttrContext> env;
998 }
1000 /* *************************************************************************
1001 * Exception checking
1002 **************************************************************************/
1004 /* The following methods treat classes as sets that contain
1005 * the class itself and all their subclasses
1006 */
1008 /** Is given type a subtype of some of the types in given list?
1009 */
1010 boolean subset(Type t, List<Type> ts) {
1011 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1012 if (types.isSubtype(t, l.head)) return true;
1013 return false;
1014 }
1016 /** Is given type a subtype or supertype of
1017 * some of the types in given list?
1018 */
1019 boolean intersects(Type t, List<Type> ts) {
1020 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1021 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1022 return false;
1023 }
1025 /** Add type set to given type list, unless it is a subclass of some class
1026 * in the list.
1027 */
1028 List<Type> incl(Type t, List<Type> ts) {
1029 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1030 }
1032 /** Remove type set from type set list.
1033 */
1034 List<Type> excl(Type t, List<Type> ts) {
1035 if (ts.isEmpty()) {
1036 return ts;
1037 } else {
1038 List<Type> ts1 = excl(t, ts.tail);
1039 if (types.isSubtype(ts.head, t)) return ts1;
1040 else if (ts1 == ts.tail) return ts;
1041 else return ts1.prepend(ts.head);
1042 }
1043 }
1045 /** Form the union of two type set lists.
1046 */
1047 List<Type> union(List<Type> ts1, List<Type> ts2) {
1048 List<Type> ts = ts1;
1049 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1050 ts = incl(l.head, ts);
1051 return ts;
1052 }
1054 /** Form the difference of two type lists.
1055 */
1056 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1057 List<Type> ts = ts1;
1058 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1059 ts = excl(l.head, ts);
1060 return ts;
1061 }
1063 /** Form the intersection of two type lists.
1064 */
1065 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1066 List<Type> ts = List.nil();
1067 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1068 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1069 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1070 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1071 return ts;
1072 }
1074 /** Is exc an exception symbol that need not be declared?
1075 */
1076 boolean isUnchecked(ClassSymbol exc) {
1077 return
1078 exc.kind == ERR ||
1079 exc.isSubClass(syms.errorType.tsym, types) ||
1080 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1081 }
1083 /** Is exc an exception type that need not be declared?
1084 */
1085 boolean isUnchecked(Type exc) {
1086 return
1087 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
1088 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
1089 exc.tag == BOT;
1090 }
1092 /** Same, but handling completion failures.
1093 */
1094 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1095 try {
1096 return isUnchecked(exc);
1097 } catch (CompletionFailure ex) {
1098 completionError(pos, ex);
1099 return true;
1100 }
1101 }
1103 /** Is exc handled by given exception list?
1104 */
1105 boolean isHandled(Type exc, List<Type> handled) {
1106 return isUnchecked(exc) || subset(exc, handled);
1107 }
1109 /** Return all exceptions in thrown list that are not in handled list.
1110 * @param thrown The list of thrown exceptions.
1111 * @param handled The list of handled exceptions.
1112 */
1113 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1114 List<Type> unhandled = List.nil();
1115 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1116 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1117 return unhandled;
1118 }
1120 /* *************************************************************************
1121 * Overriding/Implementation checking
1122 **************************************************************************/
1124 /** The level of access protection given by a flag set,
1125 * where PRIVATE is highest and PUBLIC is lowest.
1126 */
1127 static int protection(long flags) {
1128 switch ((short)(flags & AccessFlags)) {
1129 case PRIVATE: return 3;
1130 case PROTECTED: return 1;
1131 default:
1132 case PUBLIC: return 0;
1133 case 0: return 2;
1134 }
1135 }
1137 /** A customized "cannot override" error message.
1138 * @param m The overriding method.
1139 * @param other The overridden method.
1140 * @return An internationalized string.
1141 */
1142 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1143 String key;
1144 if ((other.owner.flags() & INTERFACE) == 0)
1145 key = "cant.override";
1146 else if ((m.owner.flags() & INTERFACE) == 0)
1147 key = "cant.implement";
1148 else
1149 key = "clashes.with";
1150 return diags.fragment(key, m, m.location(), other, other.location());
1151 }
1153 /** A customized "override" warning message.
1154 * @param m The overriding method.
1155 * @param other The overridden method.
1156 * @return An internationalized string.
1157 */
1158 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1159 String key;
1160 if ((other.owner.flags() & INTERFACE) == 0)
1161 key = "unchecked.override";
1162 else if ((m.owner.flags() & INTERFACE) == 0)
1163 key = "unchecked.implement";
1164 else
1165 key = "unchecked.clash.with";
1166 return diags.fragment(key, m, m.location(), other, other.location());
1167 }
1169 /** A customized "override" warning message.
1170 * @param m The overriding method.
1171 * @param other The overridden method.
1172 * @return An internationalized string.
1173 */
1174 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1175 String key;
1176 if ((other.owner.flags() & INTERFACE) == 0)
1177 key = "varargs.override";
1178 else if ((m.owner.flags() & INTERFACE) == 0)
1179 key = "varargs.implement";
1180 else
1181 key = "varargs.clash.with";
1182 return diags.fragment(key, m, m.location(), other, other.location());
1183 }
1185 /** Check that this method conforms with overridden method 'other'.
1186 * where `origin' is the class where checking started.
1187 * Complications:
1188 * (1) Do not check overriding of synthetic methods
1189 * (reason: they might be final).
1190 * todo: check whether this is still necessary.
1191 * (2) Admit the case where an interface proxy throws fewer exceptions
1192 * than the method it implements. Augment the proxy methods with the
1193 * undeclared exceptions in this case.
1194 * (3) When generics are enabled, admit the case where an interface proxy
1195 * has a result type
1196 * extended by the result type of the method it implements.
1197 * Change the proxies result type to the smaller type in this case.
1198 *
1199 * @param tree The tree from which positions
1200 * are extracted for errors.
1201 * @param m The overriding method.
1202 * @param other The overridden method.
1203 * @param origin The class of which the overriding method
1204 * is a member.
1205 */
1206 void checkOverride(JCTree tree,
1207 MethodSymbol m,
1208 MethodSymbol other,
1209 ClassSymbol origin) {
1210 // Don't check overriding of synthetic methods or by bridge methods.
1211 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1212 return;
1213 }
1215 // Error if static method overrides instance method (JLS 8.4.6.2).
1216 if ((m.flags() & STATIC) != 0 &&
1217 (other.flags() & STATIC) == 0) {
1218 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1219 cannotOverride(m, other));
1220 return;
1221 }
1223 // Error if instance method overrides static or final
1224 // method (JLS 8.4.6.1).
1225 if ((other.flags() & FINAL) != 0 ||
1226 (m.flags() & STATIC) == 0 &&
1227 (other.flags() & STATIC) != 0) {
1228 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1229 cannotOverride(m, other),
1230 asFlagSet(other.flags() & (FINAL | STATIC)));
1231 return;
1232 }
1234 if ((m.owner.flags() & ANNOTATION) != 0) {
1235 // handled in validateAnnotationMethod
1236 return;
1237 }
1239 // Error if overriding method has weaker access (JLS 8.4.6.3).
1240 if ((origin.flags() & INTERFACE) == 0 &&
1241 protection(m.flags()) > protection(other.flags())) {
1242 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1243 cannotOverride(m, other),
1244 other.flags() == 0 ?
1245 Flag.PACKAGE :
1246 asFlagSet(other.flags() & AccessFlags));
1247 return;
1248 }
1250 Type mt = types.memberType(origin.type, m);
1251 Type ot = types.memberType(origin.type, other);
1252 // Error if overriding result type is different
1253 // (or, in the case of generics mode, not a subtype) of
1254 // overridden result type. We have to rename any type parameters
1255 // before comparing types.
1256 List<Type> mtvars = mt.getTypeArguments();
1257 List<Type> otvars = ot.getTypeArguments();
1258 Type mtres = mt.getReturnType();
1259 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1261 overrideWarner.warned = false;
1262 boolean resultTypesOK =
1263 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1264 if (!resultTypesOK) {
1265 if (!allowCovariantReturns &&
1266 m.owner != origin &&
1267 m.owner.isSubClass(other.owner, types)) {
1268 // allow limited interoperability with covariant returns
1269 } else {
1270 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1271 "override.incompatible.ret",
1272 cannotOverride(m, other),
1273 mtres, otres);
1274 return;
1275 }
1276 } else if (overrideWarner.warned) {
1277 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1278 "override.unchecked.ret",
1279 uncheckedOverrides(m, other),
1280 mtres, otres);
1281 }
1283 // Error if overriding method throws an exception not reported
1284 // by overridden method.
1285 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1286 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1287 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1288 if (unhandledErased.nonEmpty()) {
1289 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1290 "override.meth.doesnt.throw",
1291 cannotOverride(m, other),
1292 unhandledUnerased.head);
1293 return;
1294 }
1295 else if (unhandledUnerased.nonEmpty()) {
1296 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1297 "override.unchecked.thrown",
1298 cannotOverride(m, other),
1299 unhandledUnerased.head);
1300 return;
1301 }
1303 // Optional warning if varargs don't agree
1304 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1305 && lint.isEnabled(Lint.LintCategory.OVERRIDES)) {
1306 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1307 ((m.flags() & Flags.VARARGS) != 0)
1308 ? "override.varargs.missing"
1309 : "override.varargs.extra",
1310 varargsOverrides(m, other));
1311 }
1313 // Warn if instance method overrides bridge method (compiler spec ??)
1314 if ((other.flags() & BRIDGE) != 0) {
1315 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1316 uncheckedOverrides(m, other));
1317 }
1319 // Warn if a deprecated method overridden by a non-deprecated one.
1320 if ((other.flags() & DEPRECATED) != 0
1321 && (m.flags() & DEPRECATED) == 0
1322 && m.outermostClass() != other.outermostClass()
1323 && !isDeprecatedOverrideIgnorable(other, origin)) {
1324 warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
1325 }
1326 }
1327 // where
1328 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1329 // If the method, m, is defined in an interface, then ignore the issue if the method
1330 // is only inherited via a supertype and also implemented in the supertype,
1331 // because in that case, we will rediscover the issue when examining the method
1332 // in the supertype.
1333 // If the method, m, is not defined in an interface, then the only time we need to
1334 // address the issue is when the method is the supertype implemementation: any other
1335 // case, we will have dealt with when examining the supertype classes
1336 ClassSymbol mc = m.enclClass();
1337 Type st = types.supertype(origin.type);
1338 if (st.tag != CLASS)
1339 return true;
1340 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1342 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1343 List<Type> intfs = types.interfaces(origin.type);
1344 return (intfs.contains(mc.type) ? false : (stimpl != null));
1345 }
1346 else
1347 return (stimpl != m);
1348 }
1351 // used to check if there were any unchecked conversions
1352 Warner overrideWarner = new Warner();
1354 /** Check that a class does not inherit two concrete methods
1355 * with the same signature.
1356 * @param pos Position to be used for error reporting.
1357 * @param site The class type to be checked.
1358 */
1359 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1360 Type sup = types.supertype(site);
1361 if (sup.tag != CLASS) return;
1363 for (Type t1 = sup;
1364 t1.tsym.type.isParameterized();
1365 t1 = types.supertype(t1)) {
1366 for (Scope.Entry e1 = t1.tsym.members().elems;
1367 e1 != null;
1368 e1 = e1.sibling) {
1369 Symbol s1 = e1.sym;
1370 if (s1.kind != MTH ||
1371 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1372 !s1.isInheritedIn(site.tsym, types) ||
1373 ((MethodSymbol)s1).implementation(site.tsym,
1374 types,
1375 true) != s1)
1376 continue;
1377 Type st1 = types.memberType(t1, s1);
1378 int s1ArgsLength = st1.getParameterTypes().length();
1379 if (st1 == s1.type) continue;
1381 for (Type t2 = sup;
1382 t2.tag == CLASS;
1383 t2 = types.supertype(t2)) {
1384 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1385 e2.scope != null;
1386 e2 = e2.next()) {
1387 Symbol s2 = e2.sym;
1388 if (s2 == s1 ||
1389 s2.kind != MTH ||
1390 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1391 s2.type.getParameterTypes().length() != s1ArgsLength ||
1392 !s2.isInheritedIn(site.tsym, types) ||
1393 ((MethodSymbol)s2).implementation(site.tsym,
1394 types,
1395 true) != s2)
1396 continue;
1397 Type st2 = types.memberType(t2, s2);
1398 if (types.overrideEquivalent(st1, st2))
1399 log.error(pos, "concrete.inheritance.conflict",
1400 s1, t1, s2, t2, sup);
1401 }
1402 }
1403 }
1404 }
1405 }
1407 /** Check that classes (or interfaces) do not each define an abstract
1408 * method with same name and arguments but incompatible return types.
1409 * @param pos Position to be used for error reporting.
1410 * @param t1 The first argument type.
1411 * @param t2 The second argument type.
1412 */
1413 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1414 Type t1,
1415 Type t2) {
1416 return checkCompatibleAbstracts(pos, t1, t2,
1417 types.makeCompoundType(t1, t2));
1418 }
1420 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1421 Type t1,
1422 Type t2,
1423 Type site) {
1424 Symbol sym = firstIncompatibility(t1, t2, site);
1425 if (sym != null) {
1426 log.error(pos, "types.incompatible.diff.ret",
1427 t1, t2, sym.name +
1428 "(" + types.memberType(t2, sym).getParameterTypes() + ")");
1429 return false;
1430 }
1431 return true;
1432 }
1434 /** Return the first method which is defined with same args
1435 * but different return types in two given interfaces, or null if none
1436 * exists.
1437 * @param t1 The first type.
1438 * @param t2 The second type.
1439 * @param site The most derived type.
1440 * @returns symbol from t2 that conflicts with one in t1.
1441 */
1442 private Symbol firstIncompatibility(Type t1, Type t2, Type site) {
1443 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1444 closure(t1, interfaces1);
1445 Map<TypeSymbol,Type> interfaces2;
1446 if (t1 == t2)
1447 interfaces2 = interfaces1;
1448 else
1449 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1451 for (Type t3 : interfaces1.values()) {
1452 for (Type t4 : interfaces2.values()) {
1453 Symbol s = firstDirectIncompatibility(t3, t4, site);
1454 if (s != null) return s;
1455 }
1456 }
1457 return null;
1458 }
1460 /** Compute all the supertypes of t, indexed by type symbol. */
1461 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1462 if (t.tag != CLASS) return;
1463 if (typeMap.put(t.tsym, t) == null) {
1464 closure(types.supertype(t), typeMap);
1465 for (Type i : types.interfaces(t))
1466 closure(i, typeMap);
1467 }
1468 }
1470 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1471 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1472 if (t.tag != CLASS) return;
1473 if (typesSkip.get(t.tsym) != null) return;
1474 if (typeMap.put(t.tsym, t) == null) {
1475 closure(types.supertype(t), typesSkip, typeMap);
1476 for (Type i : types.interfaces(t))
1477 closure(i, typesSkip, typeMap);
1478 }
1479 }
1481 /** Return the first method in t2 that conflicts with a method from t1. */
1482 private Symbol firstDirectIncompatibility(Type t1, Type t2, Type site) {
1483 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1484 Symbol s1 = e1.sym;
1485 Type st1 = null;
1486 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1487 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1488 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1489 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1490 Symbol s2 = e2.sym;
1491 if (s1 == s2) continue;
1492 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1493 if (st1 == null) st1 = types.memberType(t1, s1);
1494 Type st2 = types.memberType(t2, s2);
1495 if (types.overrideEquivalent(st1, st2)) {
1496 List<Type> tvars1 = st1.getTypeArguments();
1497 List<Type> tvars2 = st2.getTypeArguments();
1498 Type rt1 = st1.getReturnType();
1499 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1500 boolean compat =
1501 types.isSameType(rt1, rt2) ||
1502 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1503 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1504 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1505 checkCommonOverriderIn(s1,s2,site);
1506 if (!compat) return s2;
1507 }
1508 }
1509 }
1510 return null;
1511 }
1512 //WHERE
1513 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1514 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1515 Type st1 = types.memberType(site, s1);
1516 Type st2 = types.memberType(site, s2);
1517 closure(site, supertypes);
1518 for (Type t : supertypes.values()) {
1519 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1520 Symbol s3 = e.sym;
1521 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1522 Type st3 = types.memberType(site,s3);
1523 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1524 if (s3.owner == site.tsym) {
1525 return true;
1526 }
1527 List<Type> tvars1 = st1.getTypeArguments();
1528 List<Type> tvars2 = st2.getTypeArguments();
1529 List<Type> tvars3 = st3.getTypeArguments();
1530 Type rt1 = st1.getReturnType();
1531 Type rt2 = st2.getReturnType();
1532 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1533 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1534 boolean compat =
1535 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1536 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1537 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1538 if (compat)
1539 return true;
1540 }
1541 }
1542 }
1543 return false;
1544 }
1546 /** Check that a given method conforms with any method it overrides.
1547 * @param tree The tree from which positions are extracted
1548 * for errors.
1549 * @param m The overriding method.
1550 */
1551 void checkOverride(JCTree tree, MethodSymbol m) {
1552 ClassSymbol origin = (ClassSymbol)m.owner;
1553 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1554 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1555 log.error(tree.pos(), "enum.no.finalize");
1556 return;
1557 }
1558 for (Type t = types.supertype(origin.type); t.tag == CLASS;
1559 t = types.supertype(t)) {
1560 TypeSymbol c = t.tsym;
1561 Scope.Entry e = c.members().lookup(m.name);
1562 while (e.scope != null) {
1563 if (m.overrides(e.sym, origin, types, false))
1564 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1565 else if (e.sym.kind == MTH &&
1566 e.sym.isInheritedIn(origin, types) &&
1567 (e.sym.flags() & SYNTHETIC) == 0 &&
1568 !m.isConstructor()) {
1569 Type er1 = m.erasure(types);
1570 Type er2 = e.sym.erasure(types);
1571 if (types.isSameTypes(er1.getParameterTypes(),
1572 er2.getParameterTypes())) {
1573 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1574 "name.clash.same.erasure.no.override",
1575 m, m.location(),
1576 e.sym, e.sym.location());
1577 }
1578 }
1579 e = e.next();
1580 }
1581 }
1582 }
1584 /** Check that all abstract members of given class have definitions.
1585 * @param pos Position to be used for error reporting.
1586 * @param c The class.
1587 */
1588 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1589 try {
1590 MethodSymbol undef = firstUndef(c, c);
1591 if (undef != null) {
1592 if ((c.flags() & ENUM) != 0 &&
1593 types.supertype(c.type).tsym == syms.enumSym &&
1594 (c.flags() & FINAL) == 0) {
1595 // add the ABSTRACT flag to an enum
1596 c.flags_field |= ABSTRACT;
1597 } else {
1598 MethodSymbol undef1 =
1599 new MethodSymbol(undef.flags(), undef.name,
1600 types.memberType(c.type, undef), undef.owner);
1601 log.error(pos, "does.not.override.abstract",
1602 c, undef1, undef1.location());
1603 }
1604 }
1605 } catch (CompletionFailure ex) {
1606 completionError(pos, ex);
1607 }
1608 }
1609 //where
1610 /** Return first abstract member of class `c' that is not defined
1611 * in `impl', null if there is none.
1612 */
1613 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1614 MethodSymbol undef = null;
1615 // Do not bother to search in classes that are not abstract,
1616 // since they cannot have abstract members.
1617 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1618 Scope s = c.members();
1619 for (Scope.Entry e = s.elems;
1620 undef == null && e != null;
1621 e = e.sibling) {
1622 if (e.sym.kind == MTH &&
1623 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1624 MethodSymbol absmeth = (MethodSymbol)e.sym;
1625 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1626 if (implmeth == null || implmeth == absmeth)
1627 undef = absmeth;
1628 }
1629 }
1630 if (undef == null) {
1631 Type st = types.supertype(c.type);
1632 if (st.tag == CLASS)
1633 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1634 }
1635 for (List<Type> l = types.interfaces(c.type);
1636 undef == null && l.nonEmpty();
1637 l = l.tail) {
1638 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1639 }
1640 }
1641 return undef;
1642 }
1644 /** Check for cyclic references. Issue an error if the
1645 * symbol of the type referred to has a LOCKED flag set.
1646 *
1647 * @param pos Position to be used for error reporting.
1648 * @param t The type referred to.
1649 */
1650 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1651 checkNonCyclicInternal(pos, t);
1652 }
1655 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1656 checkNonCyclic1(pos, t, List.<TypeVar>nil());
1657 }
1659 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
1660 final TypeVar tv;
1661 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1662 return;
1663 if (seen.contains(t)) {
1664 tv = (TypeVar)t;
1665 tv.bound = types.createErrorType(t);
1666 log.error(pos, "cyclic.inheritance", t);
1667 } else if (t.tag == TYPEVAR) {
1668 tv = (TypeVar)t;
1669 seen = seen.prepend(tv);
1670 for (Type b : types.getBounds(tv))
1671 checkNonCyclic1(pos, b, seen);
1672 }
1673 }
1675 /** Check for cyclic references. Issue an error if the
1676 * symbol of the type referred to has a LOCKED flag set.
1677 *
1678 * @param pos Position to be used for error reporting.
1679 * @param t The type referred to.
1680 * @returns True if the check completed on all attributed classes
1681 */
1682 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1683 boolean complete = true; // was the check complete?
1684 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1685 Symbol c = t.tsym;
1686 if ((c.flags_field & ACYCLIC) != 0) return true;
1688 if ((c.flags_field & LOCKED) != 0) {
1689 noteCyclic(pos, (ClassSymbol)c);
1690 } else if (!c.type.isErroneous()) {
1691 try {
1692 c.flags_field |= LOCKED;
1693 if (c.type.tag == CLASS) {
1694 ClassType clazz = (ClassType)c.type;
1695 if (clazz.interfaces_field != null)
1696 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1697 complete &= checkNonCyclicInternal(pos, l.head);
1698 if (clazz.supertype_field != null) {
1699 Type st = clazz.supertype_field;
1700 if (st != null && st.tag == CLASS)
1701 complete &= checkNonCyclicInternal(pos, st);
1702 }
1703 if (c.owner.kind == TYP)
1704 complete &= checkNonCyclicInternal(pos, c.owner.type);
1705 }
1706 } finally {
1707 c.flags_field &= ~LOCKED;
1708 }
1709 }
1710 if (complete)
1711 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1712 if (complete) c.flags_field |= ACYCLIC;
1713 return complete;
1714 }
1716 /** Note that we found an inheritance cycle. */
1717 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1718 log.error(pos, "cyclic.inheritance", c);
1719 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1720 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
1721 Type st = types.supertype(c.type);
1722 if (st.tag == CLASS)
1723 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
1724 c.type = types.createErrorType(c, c.type);
1725 c.flags_field |= ACYCLIC;
1726 }
1728 /** Check that all methods which implement some
1729 * method conform to the method they implement.
1730 * @param tree The class definition whose members are checked.
1731 */
1732 void checkImplementations(JCClassDecl tree) {
1733 checkImplementations(tree, tree.sym);
1734 }
1735 //where
1736 /** Check that all methods which implement some
1737 * method in `ic' conform to the method they implement.
1738 */
1739 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
1740 ClassSymbol origin = tree.sym;
1741 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
1742 ClassSymbol lc = (ClassSymbol)l.head.tsym;
1743 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
1744 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
1745 if (e.sym.kind == MTH &&
1746 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
1747 MethodSymbol absmeth = (MethodSymbol)e.sym;
1748 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
1749 if (implmeth != null && implmeth != absmeth &&
1750 (implmeth.owner.flags() & INTERFACE) ==
1751 (origin.flags() & INTERFACE)) {
1752 // don't check if implmeth is in a class, yet
1753 // origin is an interface. This case arises only
1754 // if implmeth is declared in Object. The reason is
1755 // that interfaces really don't inherit from
1756 // Object it's just that the compiler represents
1757 // things that way.
1758 checkOverride(tree, implmeth, absmeth, origin);
1759 }
1760 }
1761 }
1762 }
1763 }
1764 }
1766 /** Check that all abstract methods implemented by a class are
1767 * mutually compatible.
1768 * @param pos Position to be used for error reporting.
1769 * @param c The class whose interfaces are checked.
1770 */
1771 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
1772 List<Type> supertypes = types.interfaces(c);
1773 Type supertype = types.supertype(c);
1774 if (supertype.tag == CLASS &&
1775 (supertype.tsym.flags() & ABSTRACT) != 0)
1776 supertypes = supertypes.prepend(supertype);
1777 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
1778 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
1779 !checkCompatibleAbstracts(pos, l.head, l.head, c))
1780 return;
1781 for (List<Type> m = supertypes; m != l; m = m.tail)
1782 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
1783 return;
1784 }
1785 checkCompatibleConcretes(pos, c);
1786 }
1788 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
1789 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
1790 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
1791 // VM allows methods and variables with differing types
1792 if (sym.kind == e.sym.kind &&
1793 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
1794 sym != e.sym &&
1795 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
1796 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
1797 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
1798 return;
1799 }
1800 }
1801 }
1802 }
1804 /** Report a conflict between a user symbol and a synthetic symbol.
1805 */
1806 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
1807 if (!sym.type.isErroneous()) {
1808 if (warnOnSyntheticConflicts) {
1809 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
1810 }
1811 else {
1812 log.error(pos, "synthetic.name.conflict", sym, sym.location());
1813 }
1814 }
1815 }
1817 /** Check that class c does not implement directly or indirectly
1818 * the same parameterized interface with two different argument lists.
1819 * @param pos Position to be used for error reporting.
1820 * @param type The type whose interfaces are checked.
1821 */
1822 void checkClassBounds(DiagnosticPosition pos, Type type) {
1823 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
1824 }
1825 //where
1826 /** Enter all interfaces of type `type' into the hash table `seensofar'
1827 * with their class symbol as key and their type as value. Make
1828 * sure no class is entered with two different types.
1829 */
1830 void checkClassBounds(DiagnosticPosition pos,
1831 Map<TypeSymbol,Type> seensofar,
1832 Type type) {
1833 if (type.isErroneous()) return;
1834 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
1835 Type it = l.head;
1836 Type oldit = seensofar.put(it.tsym, it);
1837 if (oldit != null) {
1838 List<Type> oldparams = oldit.allparams();
1839 List<Type> newparams = it.allparams();
1840 if (!types.containsTypeEquivalent(oldparams, newparams))
1841 log.error(pos, "cant.inherit.diff.arg",
1842 it.tsym, Type.toString(oldparams),
1843 Type.toString(newparams));
1844 }
1845 checkClassBounds(pos, seensofar, it);
1846 }
1847 Type st = types.supertype(type);
1848 if (st != null) checkClassBounds(pos, seensofar, st);
1849 }
1851 /** Enter interface into into set.
1852 * If it existed already, issue a "repeated interface" error.
1853 */
1854 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
1855 if (its.contains(it))
1856 log.error(pos, "repeated.interface");
1857 else {
1858 its.add(it);
1859 }
1860 }
1862 /* *************************************************************************
1863 * Check annotations
1864 **************************************************************************/
1866 /** Annotation types are restricted to primitives, String, an
1867 * enum, an annotation, Class, Class<?>, Class<? extends
1868 * Anything>, arrays of the preceding.
1869 */
1870 void validateAnnotationType(JCTree restype) {
1871 // restype may be null if an error occurred, so don't bother validating it
1872 if (restype != null) {
1873 validateAnnotationType(restype.pos(), restype.type);
1874 }
1875 }
1877 void validateAnnotationType(DiagnosticPosition pos, Type type) {
1878 if (type.isPrimitive()) return;
1879 if (types.isSameType(type, syms.stringType)) return;
1880 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
1881 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
1882 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
1883 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
1884 validateAnnotationType(pos, types.elemtype(type));
1885 return;
1886 }
1887 log.error(pos, "invalid.annotation.member.type");
1888 }
1890 /**
1891 * "It is also a compile-time error if any method declared in an
1892 * annotation type has a signature that is override-equivalent to
1893 * that of any public or protected method declared in class Object
1894 * or in the interface annotation.Annotation."
1895 *
1896 * @jls3 9.6 Annotation Types
1897 */
1898 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
1899 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
1900 Scope s = sup.tsym.members();
1901 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
1902 if (e.sym.kind == MTH &&
1903 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
1904 types.overrideEquivalent(m.type, e.sym.type))
1905 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
1906 }
1907 }
1908 }
1910 /** Check the annotations of a symbol.
1911 */
1912 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
1913 if (skipAnnotations) return;
1914 for (JCAnnotation a : annotations)
1915 validateAnnotation(a, s);
1916 }
1918 /** Check the type annotations
1919 */
1920 public void validateTypeAnnotations(List<JCTypeAnnotation> annotations, boolean isTypeParameter) {
1921 if (skipAnnotations) return;
1922 for (JCTypeAnnotation a : annotations)
1923 validateTypeAnnotation(a, isTypeParameter);
1924 }
1926 /** Check an annotation of a symbol.
1927 */
1928 public void validateAnnotation(JCAnnotation a, Symbol s) {
1929 validateAnnotation(a);
1931 if (!annotationApplicable(a, s))
1932 log.error(a.pos(), "annotation.type.not.applicable");
1934 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
1935 if (!isOverrider(s))
1936 log.error(a.pos(), "method.does.not.override.superclass");
1937 }
1938 }
1940 public void validateTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
1941 if (a.type == null)
1942 throw new AssertionError("annotation tree hasn't been attributed yet: " + a);
1943 validateAnnotation(a);
1945 if (!isTypeAnnotation(a, isTypeParameter))
1946 log.error(a.pos(), "annotation.type.not.applicable");
1947 }
1949 /** Is s a method symbol that overrides a method in a superclass? */
1950 boolean isOverrider(Symbol s) {
1951 if (s.kind != MTH || s.isStatic())
1952 return false;
1953 MethodSymbol m = (MethodSymbol)s;
1954 TypeSymbol owner = (TypeSymbol)m.owner;
1955 for (Type sup : types.closure(owner.type)) {
1956 if (sup == owner.type)
1957 continue; // skip "this"
1958 Scope scope = sup.tsym.members();
1959 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
1960 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
1961 return true;
1962 }
1963 }
1964 return false;
1965 }
1967 /** Is the annotation applicable to type annotations */
1968 boolean isTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
1969 Attribute.Compound atTarget =
1970 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
1971 if (atTarget == null) return true;
1972 Attribute atValue = atTarget.member(names.value);
1973 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
1974 Attribute.Array arr = (Attribute.Array) atValue;
1975 for (Attribute app : arr.values) {
1976 if (!(app instanceof Attribute.Enum)) return true; // recovery
1977 Attribute.Enum e = (Attribute.Enum) app;
1978 if (!isTypeParameter && e.value.name == names.TYPE_USE)
1979 return true;
1980 else if (isTypeParameter && e.value.name == names.TYPE_PARAMETER)
1981 return true;
1982 }
1983 return false;
1984 }
1986 /** Is the annotation applicable to the symbol? */
1987 boolean annotationApplicable(JCAnnotation a, Symbol s) {
1988 Attribute.Compound atTarget =
1989 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
1990 if (atTarget == null) return true;
1991 Attribute atValue = atTarget.member(names.value);
1992 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
1993 Attribute.Array arr = (Attribute.Array) atValue;
1994 for (Attribute app : arr.values) {
1995 if (!(app instanceof Attribute.Enum)) return true; // recovery
1996 Attribute.Enum e = (Attribute.Enum) app;
1997 if (e.value.name == names.TYPE)
1998 { if (s.kind == TYP) return true; }
1999 else if (e.value.name == names.FIELD)
2000 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
2001 else if (e.value.name == names.METHOD)
2002 { if (s.kind == MTH && !s.isConstructor()) return true; }
2003 else if (e.value.name == names.PARAMETER)
2004 { if (s.kind == VAR &&
2005 s.owner.kind == MTH &&
2006 (s.flags() & PARAMETER) != 0)
2007 return true;
2008 }
2009 else if (e.value.name == names.CONSTRUCTOR)
2010 { if (s.kind == MTH && s.isConstructor()) return true; }
2011 else if (e.value.name == names.LOCAL_VARIABLE)
2012 { if (s.kind == VAR && s.owner.kind == MTH &&
2013 (s.flags() & PARAMETER) == 0)
2014 return true;
2015 }
2016 else if (e.value.name == names.ANNOTATION_TYPE)
2017 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
2018 return true;
2019 }
2020 else if (e.value.name == names.PACKAGE)
2021 { if (s.kind == PCK) return true; }
2022 else if (e.value.name == names.TYPE_USE)
2023 { if (s.kind == TYP ||
2024 s.kind == VAR ||
2025 (s.kind == MTH && !s.isConstructor() &&
2026 s.type.getReturnType().tag != VOID))
2027 return true;
2028 }
2029 else
2030 return true; // recovery
2031 }
2032 return false;
2033 }
2035 /** Check an annotation value.
2036 */
2037 public void validateAnnotation(JCAnnotation a) {
2038 if (a.type.isErroneous()) return;
2040 // collect an inventory of the members
2041 Set<MethodSymbol> members = new HashSet<MethodSymbol>();
2042 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
2043 e != null;
2044 e = e.sibling)
2045 if (e.sym.kind == MTH)
2046 members.add((MethodSymbol) e.sym);
2048 // count them off as they're annotated
2049 for (JCTree arg : a.args) {
2050 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
2051 JCAssign assign = (JCAssign) arg;
2052 Symbol m = TreeInfo.symbol(assign.lhs);
2053 if (m == null || m.type.isErroneous()) continue;
2054 if (!members.remove(m))
2055 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
2056 m.name, a.type);
2057 if (assign.rhs.getTag() == ANNOTATION)
2058 validateAnnotation((JCAnnotation)assign.rhs);
2059 }
2061 // all the remaining ones better have default values
2062 for (MethodSymbol m : members)
2063 if (m.defaultValue == null && !m.type.isErroneous())
2064 log.error(a.pos(), "annotation.missing.default.value",
2065 a.type, m.name);
2067 // special case: java.lang.annotation.Target must not have
2068 // repeated values in its value member
2069 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
2070 a.args.tail == null)
2071 return;
2073 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
2074 JCAssign assign = (JCAssign) a.args.head;
2075 Symbol m = TreeInfo.symbol(assign.lhs);
2076 if (m.name != names.value) return;
2077 JCTree rhs = assign.rhs;
2078 if (rhs.getTag() != JCTree.NEWARRAY) return;
2079 JCNewArray na = (JCNewArray) rhs;
2080 Set<Symbol> targets = new HashSet<Symbol>();
2081 for (JCTree elem : na.elems) {
2082 if (!targets.add(TreeInfo.symbol(elem))) {
2083 log.error(elem.pos(), "repeated.annotation.target");
2084 }
2085 }
2086 }
2088 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
2089 if (allowAnnotations &&
2090 lint.isEnabled(Lint.LintCategory.DEP_ANN) &&
2091 (s.flags() & DEPRECATED) != 0 &&
2092 !syms.deprecatedType.isErroneous() &&
2093 s.attribute(syms.deprecatedType.tsym) == null) {
2094 log.warning(pos, "missing.deprecated.annotation");
2095 }
2096 }
2098 /* *************************************************************************
2099 * Check for recursive annotation elements.
2100 **************************************************************************/
2102 /** Check for cycles in the graph of annotation elements.
2103 */
2104 void checkNonCyclicElements(JCClassDecl tree) {
2105 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
2106 assert (tree.sym.flags_field & LOCKED) == 0;
2107 try {
2108 tree.sym.flags_field |= LOCKED;
2109 for (JCTree def : tree.defs) {
2110 if (def.getTag() != JCTree.METHODDEF) continue;
2111 JCMethodDecl meth = (JCMethodDecl)def;
2112 checkAnnotationResType(meth.pos(), meth.restype.type);
2113 }
2114 } finally {
2115 tree.sym.flags_field &= ~LOCKED;
2116 tree.sym.flags_field |= ACYCLIC_ANN;
2117 }
2118 }
2120 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
2121 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
2122 return;
2123 if ((tsym.flags_field & LOCKED) != 0) {
2124 log.error(pos, "cyclic.annotation.element");
2125 return;
2126 }
2127 try {
2128 tsym.flags_field |= LOCKED;
2129 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
2130 Symbol s = e.sym;
2131 if (s.kind != Kinds.MTH)
2132 continue;
2133 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
2134 }
2135 } finally {
2136 tsym.flags_field &= ~LOCKED;
2137 tsym.flags_field |= ACYCLIC_ANN;
2138 }
2139 }
2141 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
2142 switch (type.tag) {
2143 case TypeTags.CLASS:
2144 if ((type.tsym.flags() & ANNOTATION) != 0)
2145 checkNonCyclicElementsInternal(pos, type.tsym);
2146 break;
2147 case TypeTags.ARRAY:
2148 checkAnnotationResType(pos, types.elemtype(type));
2149 break;
2150 default:
2151 break; // int etc
2152 }
2153 }
2155 /* *************************************************************************
2156 * Check for cycles in the constructor call graph.
2157 **************************************************************************/
2159 /** Check for cycles in the graph of constructors calling other
2160 * constructors.
2161 */
2162 void checkCyclicConstructors(JCClassDecl tree) {
2163 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
2165 // enter each constructor this-call into the map
2166 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2167 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
2168 if (app == null) continue;
2169 JCMethodDecl meth = (JCMethodDecl) l.head;
2170 if (TreeInfo.name(app.meth) == names._this) {
2171 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
2172 } else {
2173 meth.sym.flags_field |= ACYCLIC;
2174 }
2175 }
2177 // Check for cycles in the map
2178 Symbol[] ctors = new Symbol[0];
2179 ctors = callMap.keySet().toArray(ctors);
2180 for (Symbol caller : ctors) {
2181 checkCyclicConstructor(tree, caller, callMap);
2182 }
2183 }
2185 /** Look in the map to see if the given constructor is part of a
2186 * call cycle.
2187 */
2188 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2189 Map<Symbol,Symbol> callMap) {
2190 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2191 if ((ctor.flags_field & LOCKED) != 0) {
2192 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2193 "recursive.ctor.invocation");
2194 } else {
2195 ctor.flags_field |= LOCKED;
2196 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2197 ctor.flags_field &= ~LOCKED;
2198 }
2199 ctor.flags_field |= ACYCLIC;
2200 }
2201 }
2203 /* *************************************************************************
2204 * Miscellaneous
2205 **************************************************************************/
2207 /**
2208 * Return the opcode of the operator but emit an error if it is an
2209 * error.
2210 * @param pos position for error reporting.
2211 * @param operator an operator
2212 * @param tag a tree tag
2213 * @param left type of left hand side
2214 * @param right type of right hand side
2215 */
2216 int checkOperator(DiagnosticPosition pos,
2217 OperatorSymbol operator,
2218 int tag,
2219 Type left,
2220 Type right) {
2221 if (operator.opcode == ByteCodes.error) {
2222 log.error(pos,
2223 "operator.cant.be.applied",
2224 treeinfo.operatorName(tag),
2225 List.of(left, right));
2226 }
2227 return operator.opcode;
2228 }
2231 /**
2232 * Check for division by integer constant zero
2233 * @param pos Position for error reporting.
2234 * @param operator The operator for the expression
2235 * @param operand The right hand operand for the expression
2236 */
2237 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2238 if (operand.constValue() != null
2239 && lint.isEnabled(Lint.LintCategory.DIVZERO)
2240 && operand.tag <= LONG
2241 && ((Number) (operand.constValue())).longValue() == 0) {
2242 int opc = ((OperatorSymbol)operator).opcode;
2243 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2244 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2245 log.warning(pos, "div.zero");
2246 }
2247 }
2248 }
2250 /**
2251 * Check for empty statements after if
2252 */
2253 void checkEmptyIf(JCIf tree) {
2254 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(Lint.LintCategory.EMPTY))
2255 log.warning(tree.thenpart.pos(), "empty.if");
2256 }
2258 /** Check that symbol is unique in given scope.
2259 * @param pos Position for error reporting.
2260 * @param sym The symbol.
2261 * @param s The scope.
2262 */
2263 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2264 if (sym.type.isErroneous())
2265 return true;
2266 if (sym.owner.name == names.any) return false;
2267 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2268 if (sym != e.sym &&
2269 sym.kind == e.sym.kind &&
2270 sym.name != names.error &&
2271 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
2272 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
2273 varargsDuplicateError(pos, sym, e.sym);
2274 else if (sym.kind == MTH && !types.overrideEquivalent(sym.type, e.sym.type))
2275 duplicateErasureError(pos, sym, e.sym);
2276 else
2277 duplicateError(pos, e.sym);
2278 return false;
2279 }
2280 }
2281 return true;
2282 }
2283 //where
2284 /** Report duplicate declaration error.
2285 */
2286 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
2287 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
2288 log.error(pos, "name.clash.same.erasure", sym1, sym2);
2289 }
2290 }
2292 /** Check that single-type import is not already imported or top-level defined,
2293 * but make an exception for two single-type imports which denote the same type.
2294 * @param pos Position for error reporting.
2295 * @param sym The symbol.
2296 * @param s The scope
2297 */
2298 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2299 return checkUniqueImport(pos, sym, s, false);
2300 }
2302 /** Check that static single-type import is not already imported or top-level defined,
2303 * but make an exception for two single-type imports which denote the same type.
2304 * @param pos Position for error reporting.
2305 * @param sym The symbol.
2306 * @param s The scope
2307 * @param staticImport Whether or not this was a static import
2308 */
2309 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2310 return checkUniqueImport(pos, sym, s, true);
2311 }
2313 /** Check that single-type import is not already imported or top-level defined,
2314 * but make an exception for two single-type imports which denote the same type.
2315 * @param pos Position for error reporting.
2316 * @param sym The symbol.
2317 * @param s The scope.
2318 * @param staticImport Whether or not this was a static import
2319 */
2320 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2321 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2322 // is encountered class entered via a class declaration?
2323 boolean isClassDecl = e.scope == s;
2324 if ((isClassDecl || sym != e.sym) &&
2325 sym.kind == e.sym.kind &&
2326 sym.name != names.error) {
2327 if (!e.sym.type.isErroneous()) {
2328 String what = e.sym.toString();
2329 if (!isClassDecl) {
2330 if (staticImport)
2331 log.error(pos, "already.defined.static.single.import", what);
2332 else
2333 log.error(pos, "already.defined.single.import", what);
2334 }
2335 else if (sym != e.sym)
2336 log.error(pos, "already.defined.this.unit", what);
2337 }
2338 return false;
2339 }
2340 }
2341 return true;
2342 }
2344 /** Check that a qualified name is in canonical form (for import decls).
2345 */
2346 public void checkCanonical(JCTree tree) {
2347 if (!isCanonical(tree))
2348 log.error(tree.pos(), "import.requires.canonical",
2349 TreeInfo.symbol(tree));
2350 }
2351 // where
2352 private boolean isCanonical(JCTree tree) {
2353 while (tree.getTag() == JCTree.SELECT) {
2354 JCFieldAccess s = (JCFieldAccess) tree;
2355 if (s.sym.owner != TreeInfo.symbol(s.selected))
2356 return false;
2357 tree = s.selected;
2358 }
2359 return true;
2360 }
2362 private class ConversionWarner extends Warner {
2363 final String key;
2364 final Type found;
2365 final Type expected;
2366 public ConversionWarner(DiagnosticPosition pos, String key, Type found, Type expected) {
2367 super(pos);
2368 this.key = key;
2369 this.found = found;
2370 this.expected = expected;
2371 }
2373 @Override
2374 public void warnUnchecked() {
2375 boolean warned = this.warned;
2376 super.warnUnchecked();
2377 if (warned) return; // suppress redundant diagnostics
2378 Object problem = diags.fragment(key);
2379 Check.this.warnUnchecked(pos(), "prob.found.req", problem, found, expected);
2380 }
2381 }
2383 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2384 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2385 }
2387 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2388 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2389 }
2390 }
