Wed, 09 Apr 2008 13:41:45 +0100
5009937: hiding versus generics versus binary compatibility
Summary: missing implementation of JLS 8.4.8.3 (different arguments with same erasure not always triggering a compiler error)
Reviewed-by: jjg
1 /*
2 * Copyright 1999-2006 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 Name.Table names;
60 private final Log log;
61 private final Symtab syms;
62 private final Infer infer;
63 private final Target target;
64 private final Source source;
65 private final Types types;
66 private final boolean skipAnnotations;
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 = Name.Table.instance(context);
85 log = Log.instance(context);
86 syms = Symtab.instance(context);
87 infer = Infer.instance(context);
88 this.types = Types.instance(context);
89 Options options = Options.instance(context);
90 target = Target.instance(context);
91 source = Source.instance(context);
92 lint = Lint.instance(context);
93 treeinfo = TreeInfo.instance(context);
95 Source source = Source.instance(context);
96 allowGenerics = source.allowGenerics();
97 allowAnnotations = source.allowAnnotations();
98 complexInference = options.get("-complexinference") != null;
99 skipAnnotations = options.get("skipAnnotations") != null;
101 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
102 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
104 deprecationHandler = new MandatoryWarningHandler(log,verboseDeprecated, "deprecated");
105 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked, "unchecked");
106 }
108 /** Switch: generics enabled?
109 */
110 boolean allowGenerics;
112 /** Switch: annotations enabled?
113 */
114 boolean allowAnnotations;
116 /** Switch: -complexinference option set?
117 */
118 boolean complexInference;
120 /** A table mapping flat names of all compiled classes in this run to their
121 * symbols; maintained from outside.
122 */
123 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
125 /** A handler for messages about deprecated usage.
126 */
127 private MandatoryWarningHandler deprecationHandler;
129 /** A handler for messages about unchecked or unsafe usage.
130 */
131 private MandatoryWarningHandler uncheckedHandler;
134 /* *************************************************************************
135 * Errors and Warnings
136 **************************************************************************/
138 Lint setLint(Lint newLint) {
139 Lint prev = lint;
140 lint = newLint;
141 return prev;
142 }
144 /** Warn about deprecated symbol.
145 * @param pos Position to be used for error reporting.
146 * @param sym The deprecated symbol.
147 */
148 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
149 if (!lint.isSuppressed(LintCategory.DEPRECATION))
150 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
151 }
153 /** Warn about unchecked operation.
154 * @param pos Position to be used for error reporting.
155 * @param msg A string describing the problem.
156 */
157 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
158 if (!lint.isSuppressed(LintCategory.UNCHECKED))
159 uncheckedHandler.report(pos, msg, args);
160 }
162 /**
163 * Report any deferred diagnostics.
164 */
165 public void reportDeferredDiagnostics() {
166 deprecationHandler.reportDeferredDiagnostic();
167 uncheckedHandler.reportDeferredDiagnostic();
168 }
171 /** Report a failure to complete a class.
172 * @param pos Position to be used for error reporting.
173 * @param ex The failure to report.
174 */
175 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
176 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
177 if (ex instanceof ClassReader.BadClassFile) throw new Abort();
178 else return syms.errType;
179 }
181 /** Report a type error.
182 * @param pos Position to be used for error reporting.
183 * @param problem A string describing the error.
184 * @param found The type that was found.
185 * @param req The type that was required.
186 */
187 Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
188 log.error(pos, "prob.found.req",
189 problem, found, req);
190 return syms.errType;
191 }
193 Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
194 log.error(pos, "prob.found.req.1", problem, found, req, explanation);
195 return syms.errType;
196 }
198 /** Report an error that wrong type tag was found.
199 * @param pos Position to be used for error reporting.
200 * @param required An internationalized string describing the type tag
201 * required.
202 * @param found The type that was found.
203 */
204 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
205 log.error(pos, "type.found.req", found, required);
206 return syms.errType;
207 }
209 /** Report an error that symbol cannot be referenced before super
210 * has been called.
211 * @param pos Position to be used for error reporting.
212 * @param sym The referenced symbol.
213 */
214 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
215 log.error(pos, "cant.ref.before.ctor.called", sym);
216 }
218 /** Report duplicate declaration error.
219 */
220 void duplicateError(DiagnosticPosition pos, Symbol sym) {
221 if (!sym.type.isErroneous()) {
222 log.error(pos, "already.defined", sym, sym.location());
223 }
224 }
226 /** Report array/varargs duplicate declaration
227 */
228 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
229 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
230 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
231 }
232 }
234 /* ************************************************************************
235 * duplicate declaration checking
236 *************************************************************************/
238 /** Check that variable does not hide variable with same name in
239 * immediately enclosing local scope.
240 * @param pos Position for error reporting.
241 * @param v The symbol.
242 * @param s The scope.
243 */
244 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
245 if (s.next != null) {
246 for (Scope.Entry e = s.next.lookup(v.name);
247 e.scope != null && e.sym.owner == v.owner;
248 e = e.next()) {
249 if (e.sym.kind == VAR &&
250 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
251 v.name != names.error) {
252 duplicateError(pos, e.sym);
253 return;
254 }
255 }
256 }
257 }
259 /** Check that a class or interface does not hide a class or
260 * interface with same name in immediately enclosing local scope.
261 * @param pos Position for error reporting.
262 * @param c The symbol.
263 * @param s The scope.
264 */
265 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
266 if (s.next != null) {
267 for (Scope.Entry e = s.next.lookup(c.name);
268 e.scope != null && e.sym.owner == c.owner;
269 e = e.next()) {
270 if (e.sym.kind == TYP &&
271 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
272 c.name != names.error) {
273 duplicateError(pos, e.sym);
274 return;
275 }
276 }
277 }
278 }
280 /** Check that class does not have the same name as one of
281 * its enclosing classes, or as a class defined in its enclosing scope.
282 * return true if class is unique in its enclosing scope.
283 * @param pos Position for error reporting.
284 * @param name The class name.
285 * @param s The enclosing scope.
286 */
287 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
288 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
289 if (e.sym.kind == TYP && e.sym.name != names.error) {
290 duplicateError(pos, e.sym);
291 return false;
292 }
293 }
294 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
295 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
296 duplicateError(pos, sym);
297 return true;
298 }
299 }
300 return true;
301 }
303 /* *************************************************************************
304 * Class name generation
305 **************************************************************************/
307 /** Return name of local class.
308 * This is of the form <enclClass> $ n <classname>
309 * where
310 * enclClass is the flat name of the enclosing class,
311 * classname is the simple name of the local class
312 */
313 Name localClassName(ClassSymbol c) {
314 for (int i=1; ; i++) {
315 Name flatname = names.
316 fromString("" + c.owner.enclClass().flatname +
317 target.syntheticNameChar() + i +
318 c.name);
319 if (compiled.get(flatname) == null) return flatname;
320 }
321 }
323 /* *************************************************************************
324 * Type Checking
325 **************************************************************************/
327 /** Check that a given type is assignable to a given proto-type.
328 * If it is, return the type, otherwise return errType.
329 * @param pos Position to be used for error reporting.
330 * @param found The type that was found.
331 * @param req The type that was required.
332 */
333 Type checkType(DiagnosticPosition pos, Type found, Type req) {
334 if (req.tag == ERROR)
335 return req;
336 if (found.tag == FORALL)
337 return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
338 if (req.tag == NONE)
339 return found;
340 if (types.isAssignable(found, req, convertWarner(pos, found, req)))
341 return found;
342 if (found.tag <= DOUBLE && req.tag <= DOUBLE)
343 return typeError(pos, JCDiagnostic.fragment("possible.loss.of.precision"), found, req);
344 if (found.isSuperBound()) {
345 log.error(pos, "assignment.from.super-bound", found);
346 return syms.errType;
347 }
348 if (req.isExtendsBound()) {
349 log.error(pos, "assignment.to.extends-bound", req);
350 return syms.errType;
351 }
352 return typeError(pos, JCDiagnostic.fragment("incompatible.types"), found, req);
353 }
355 /** Instantiate polymorphic type to some prototype, unless
356 * prototype is `anyPoly' in which case polymorphic type
357 * is returned unchanged.
358 */
359 Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) {
360 if (pt == Infer.anyPoly && complexInference) {
361 return t;
362 } else if (pt == Infer.anyPoly || pt.tag == NONE) {
363 Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
364 return instantiatePoly(pos, t, newpt, warn);
365 } else if (pt.tag == ERROR) {
366 return pt;
367 } else {
368 try {
369 return infer.instantiateExpr(t, pt, warn);
370 } catch (Infer.NoInstanceException ex) {
371 if (ex.isAmbiguous) {
372 JCDiagnostic d = ex.getDiagnostic();
373 log.error(pos,
374 "undetermined.type" + (d!=null ? ".1" : ""),
375 t, d);
376 return syms.errType;
377 } else {
378 JCDiagnostic d = ex.getDiagnostic();
379 return typeError(pos,
380 JCDiagnostic.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
381 t, pt);
382 }
383 }
384 }
385 }
387 /** Check that a given type can be cast to a given target type.
388 * Return the result of the cast.
389 * @param pos Position to be used for error reporting.
390 * @param found The type that is being cast.
391 * @param req The target type of the cast.
392 */
393 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
394 if (found.tag == FORALL) {
395 instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
396 return req;
397 } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
398 return req;
399 } else {
400 return typeError(pos,
401 JCDiagnostic.fragment("inconvertible.types"),
402 found, req);
403 }
404 }
405 //where
406 /** Is type a type variable, or a (possibly multi-dimensional) array of
407 * type variables?
408 */
409 boolean isTypeVar(Type t) {
410 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
411 }
413 /** Check that a type is within some bounds.
414 *
415 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
416 * type argument.
417 * @param pos Position to be used for error reporting.
418 * @param a The type that should be bounded by bs.
419 * @param bs The bound.
420 */
421 private void checkExtends(DiagnosticPosition pos, Type a, TypeVar bs) {
422 if (a.isUnbound()) {
423 return;
424 } else if (a.tag != WILDCARD) {
425 a = types.upperBound(a);
426 for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
427 if (!types.isSubtype(a, l.head)) {
428 log.error(pos, "not.within.bounds", a);
429 return;
430 }
431 }
432 } else if (a.isExtendsBound()) {
433 if (!types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings))
434 log.error(pos, "not.within.bounds", a);
435 } else if (a.isSuperBound()) {
436 if (types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound()))
437 log.error(pos, "not.within.bounds", a);
438 }
439 }
441 /** Check that type is different from 'void'.
442 * @param pos Position to be used for error reporting.
443 * @param t The type to be checked.
444 */
445 Type checkNonVoid(DiagnosticPosition pos, Type t) {
446 if (t.tag == VOID) {
447 log.error(pos, "void.not.allowed.here");
448 return syms.errType;
449 } else {
450 return t;
451 }
452 }
454 /** Check that type is a class or interface type.
455 * @param pos Position to be used for error reporting.
456 * @param t The type to be checked.
457 */
458 Type checkClassType(DiagnosticPosition pos, Type t) {
459 if (t.tag != CLASS && t.tag != ERROR)
460 return typeTagError(pos,
461 JCDiagnostic.fragment("type.req.class"),
462 (t.tag == TYPEVAR)
463 ? JCDiagnostic.fragment("type.parameter", t)
464 : t);
465 else
466 return t;
467 }
469 /** Check that type is a class or interface type.
470 * @param pos Position to be used for error reporting.
471 * @param t The type to be checked.
472 * @param noBounds True if type bounds are illegal here.
473 */
474 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
475 t = checkClassType(pos, t);
476 if (noBounds && t.isParameterized()) {
477 List<Type> args = t.getTypeArguments();
478 while (args.nonEmpty()) {
479 if (args.head.tag == WILDCARD)
480 return typeTagError(pos,
481 log.getLocalizedString("type.req.exact"),
482 args.head);
483 args = args.tail;
484 }
485 }
486 return t;
487 }
489 /** Check that type is a reifiable class, interface or array type.
490 * @param pos Position to be used for error reporting.
491 * @param t The type to be checked.
492 */
493 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
494 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
495 return typeTagError(pos,
496 JCDiagnostic.fragment("type.req.class.array"),
497 t);
498 } else if (!types.isReifiable(t)) {
499 log.error(pos, "illegal.generic.type.for.instof");
500 return syms.errType;
501 } else {
502 return t;
503 }
504 }
506 /** Check that type is a reference type, i.e. a class, interface or array type
507 * or a type variable.
508 * @param pos Position to be used for error reporting.
509 * @param t The type to be checked.
510 */
511 Type checkRefType(DiagnosticPosition pos, Type t) {
512 switch (t.tag) {
513 case CLASS:
514 case ARRAY:
515 case TYPEVAR:
516 case WILDCARD:
517 case ERROR:
518 return t;
519 default:
520 return typeTagError(pos,
521 JCDiagnostic.fragment("type.req.ref"),
522 t);
523 }
524 }
526 /** Check that type is a null or reference type.
527 * @param pos Position to be used for error reporting.
528 * @param t The type to be checked.
529 */
530 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
531 switch (t.tag) {
532 case CLASS:
533 case ARRAY:
534 case TYPEVAR:
535 case WILDCARD:
536 case BOT:
537 case ERROR:
538 return t;
539 default:
540 return typeTagError(pos,
541 JCDiagnostic.fragment("type.req.ref"),
542 t);
543 }
544 }
546 /** Check that flag set does not contain elements of two conflicting sets. s
547 * Return true if it doesn't.
548 * @param pos Position to be used for error reporting.
549 * @param flags The set of flags to be checked.
550 * @param set1 Conflicting flags set #1.
551 * @param set2 Conflicting flags set #2.
552 */
553 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
554 if ((flags & set1) != 0 && (flags & set2) != 0) {
555 log.error(pos,
556 "illegal.combination.of.modifiers",
557 TreeInfo.flagNames(TreeInfo.firstFlag(flags & set1)),
558 TreeInfo.flagNames(TreeInfo.firstFlag(flags & set2)));
559 return false;
560 } else
561 return true;
562 }
564 /** Check that given modifiers are legal for given symbol and
565 * return modifiers together with any implicit modififiers for that symbol.
566 * Warning: we can't use flags() here since this method
567 * is called during class enter, when flags() would cause a premature
568 * completion.
569 * @param pos Position to be used for error reporting.
570 * @param flags The set of modifiers given in a definition.
571 * @param sym The defined symbol.
572 */
573 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
574 long mask;
575 long implicit = 0;
576 switch (sym.kind) {
577 case VAR:
578 if (sym.owner.kind != TYP)
579 mask = LocalVarFlags;
580 else if ((sym.owner.flags_field & INTERFACE) != 0)
581 mask = implicit = InterfaceVarFlags;
582 else
583 mask = VarFlags;
584 break;
585 case MTH:
586 if (sym.name == names.init) {
587 if ((sym.owner.flags_field & ENUM) != 0) {
588 // enum constructors cannot be declared public or
589 // protected and must be implicitly or explicitly
590 // private
591 implicit = PRIVATE;
592 mask = PRIVATE;
593 } else
594 mask = ConstructorFlags;
595 } else if ((sym.owner.flags_field & INTERFACE) != 0)
596 mask = implicit = InterfaceMethodFlags;
597 else {
598 mask = MethodFlags;
599 }
600 // Imply STRICTFP if owner has STRICTFP set.
601 if (((flags|implicit) & Flags.ABSTRACT) == 0)
602 implicit |= sym.owner.flags_field & STRICTFP;
603 break;
604 case TYP:
605 if (sym.isLocal()) {
606 mask = LocalClassFlags;
607 if (sym.name.len == 0) { // Anonymous class
608 // Anonymous classes in static methods are themselves static;
609 // that's why we admit STATIC here.
610 mask |= STATIC;
611 // JLS: Anonymous classes are final.
612 implicit |= FINAL;
613 }
614 if ((sym.owner.flags_field & STATIC) == 0 &&
615 (flags & ENUM) != 0)
616 log.error(pos, "enums.must.be.static");
617 } else if (sym.owner.kind == TYP) {
618 mask = MemberClassFlags;
619 if (sym.owner.owner.kind == PCK ||
620 (sym.owner.flags_field & STATIC) != 0)
621 mask |= STATIC;
622 else if ((flags & ENUM) != 0)
623 log.error(pos, "enums.must.be.static");
624 // Nested interfaces and enums are always STATIC (Spec ???)
625 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
626 } else {
627 mask = ClassFlags;
628 }
629 // Interfaces are always ABSTRACT
630 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
632 if ((flags & ENUM) != 0) {
633 // enums can't be declared abstract or final
634 mask &= ~(ABSTRACT | FINAL);
635 implicit |= implicitEnumFinalFlag(tree);
636 }
637 // Imply STRICTFP if owner has STRICTFP set.
638 implicit |= sym.owner.flags_field & STRICTFP;
639 break;
640 default:
641 throw new AssertionError();
642 }
643 long illegal = flags & StandardFlags & ~mask;
644 if (illegal != 0) {
645 if ((illegal & INTERFACE) != 0) {
646 log.error(pos, "intf.not.allowed.here");
647 mask |= INTERFACE;
648 }
649 else {
650 log.error(pos,
651 "mod.not.allowed.here", TreeInfo.flagNames(illegal));
652 }
653 }
654 else if ((sym.kind == TYP ||
655 // ISSUE: Disallowing abstract&private is no longer appropriate
656 // in the presence of inner classes. Should it be deleted here?
657 checkDisjoint(pos, flags,
658 ABSTRACT,
659 PRIVATE | STATIC))
660 &&
661 checkDisjoint(pos, flags,
662 ABSTRACT | INTERFACE,
663 FINAL | NATIVE | SYNCHRONIZED)
664 &&
665 checkDisjoint(pos, flags,
666 PUBLIC,
667 PRIVATE | PROTECTED)
668 &&
669 checkDisjoint(pos, flags,
670 PRIVATE,
671 PUBLIC | PROTECTED)
672 &&
673 checkDisjoint(pos, flags,
674 FINAL,
675 VOLATILE)
676 &&
677 (sym.kind == TYP ||
678 checkDisjoint(pos, flags,
679 ABSTRACT | NATIVE,
680 STRICTFP))) {
681 // skip
682 }
683 return flags & (mask | ~StandardFlags) | implicit;
684 }
687 /** Determine if this enum should be implicitly final.
688 *
689 * If the enum has no specialized enum contants, it is final.
690 *
691 * If the enum does have specialized enum contants, it is
692 * <i>not</i> final.
693 */
694 private long implicitEnumFinalFlag(JCTree tree) {
695 if (tree.getTag() != JCTree.CLASSDEF) return 0;
696 class SpecialTreeVisitor extends JCTree.Visitor {
697 boolean specialized;
698 SpecialTreeVisitor() {
699 this.specialized = false;
700 };
702 public void visitTree(JCTree tree) { /* no-op */ }
704 public void visitVarDef(JCVariableDecl tree) {
705 if ((tree.mods.flags & ENUM) != 0) {
706 if (tree.init instanceof JCNewClass &&
707 ((JCNewClass) tree.init).def != null) {
708 specialized = true;
709 }
710 }
711 }
712 }
714 SpecialTreeVisitor sts = new SpecialTreeVisitor();
715 JCClassDecl cdef = (JCClassDecl) tree;
716 for (JCTree defs: cdef.defs) {
717 defs.accept(sts);
718 if (sts.specialized) return 0;
719 }
720 return FINAL;
721 }
723 /* *************************************************************************
724 * Type Validation
725 **************************************************************************/
727 /** Validate a type expression. That is,
728 * check that all type arguments of a parametric type are within
729 * their bounds. This must be done in a second phase after type attributon
730 * since a class might have a subclass as type parameter bound. E.g:
731 *
732 * class B<A extends C> { ... }
733 * class C extends B<C> { ... }
734 *
735 * and we can't make sure that the bound is already attributed because
736 * of possible cycles.
737 */
738 private Validator validator = new Validator();
740 /** Visitor method: Validate a type expression, if it is not null, catching
741 * and reporting any completion failures.
742 */
743 void validate(JCTree tree) {
744 try {
745 if (tree != null) tree.accept(validator);
746 } catch (CompletionFailure ex) {
747 completionError(tree.pos(), ex);
748 }
749 }
751 /** Visitor method: Validate a list of type expressions.
752 */
753 void validate(List<? extends JCTree> trees) {
754 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
755 validate(l.head);
756 }
758 /** Visitor method: Validate a list of type parameters.
759 */
760 void validateTypeParams(List<JCTypeParameter> trees) {
761 for (List<JCTypeParameter> l = trees; l.nonEmpty(); l = l.tail)
762 validate(l.head);
763 }
765 /** A visitor class for type validation.
766 */
767 class Validator extends JCTree.Visitor {
769 public void visitTypeArray(JCArrayTypeTree tree) {
770 validate(tree.elemtype);
771 }
773 public void visitTypeApply(JCTypeApply tree) {
774 if (tree.type.tag == CLASS) {
775 List<Type> formals = tree.type.tsym.type.getTypeArguments();
776 List<Type> actuals = tree.type.getTypeArguments();
777 List<JCExpression> args = tree.arguments;
778 List<Type> forms = formals;
779 ListBuffer<TypeVar> tvars_buf = new ListBuffer<TypeVar>();
781 // For matching pairs of actual argument types `a' and
782 // formal type parameters with declared bound `b' ...
783 while (args.nonEmpty() && forms.nonEmpty()) {
784 validate(args.head);
786 // exact type arguments needs to know their
787 // bounds (for upper and lower bound
788 // calculations). So we create new TypeVars with
789 // bounds substed with actuals.
790 tvars_buf.append(types.substBound(((TypeVar)forms.head),
791 formals,
792 Type.removeBounds(actuals)));
794 args = args.tail;
795 forms = forms.tail;
796 }
798 args = tree.arguments;
799 List<TypeVar> tvars = tvars_buf.toList();
800 while (args.nonEmpty() && tvars.nonEmpty()) {
801 // Let the actual arguments know their bound
802 args.head.type.withTypeVar(tvars.head);
803 args = args.tail;
804 tvars = tvars.tail;
805 }
807 args = tree.arguments;
808 tvars = tvars_buf.toList();
809 while (args.nonEmpty() && tvars.nonEmpty()) {
810 checkExtends(args.head.pos(),
811 args.head.type,
812 tvars.head);
813 args = args.tail;
814 tvars = tvars.tail;
815 }
817 // Check that this type is either fully parameterized, or
818 // not parameterized at all.
819 if (tree.type.getEnclosingType().isRaw())
820 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
821 if (tree.clazz.getTag() == JCTree.SELECT)
822 visitSelectInternal((JCFieldAccess)tree.clazz);
823 }
824 }
826 public void visitTypeParameter(JCTypeParameter tree) {
827 validate(tree.bounds);
828 checkClassBounds(tree.pos(), tree.type);
829 }
831 @Override
832 public void visitWildcard(JCWildcard tree) {
833 if (tree.inner != null)
834 validate(tree.inner);
835 }
837 public void visitSelect(JCFieldAccess tree) {
838 if (tree.type.tag == CLASS) {
839 visitSelectInternal(tree);
841 // Check that this type is either fully parameterized, or
842 // not parameterized at all.
843 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
844 log.error(tree.pos(), "improperly.formed.type.param.missing");
845 }
846 }
847 public void visitSelectInternal(JCFieldAccess tree) {
848 if (tree.type.getEnclosingType().tag != CLASS &&
849 tree.selected.type.isParameterized()) {
850 // The enclosing type is not a class, so we are
851 // looking at a static member type. However, the
852 // qualifying expression is parameterized.
853 log.error(tree.pos(), "cant.select.static.class.from.param.type");
854 } else {
855 // otherwise validate the rest of the expression
856 validate(tree.selected);
857 }
858 }
860 /** Default visitor method: do nothing.
861 */
862 public void visitTree(JCTree tree) {
863 }
864 }
866 /* *************************************************************************
867 * Exception checking
868 **************************************************************************/
870 /* The following methods treat classes as sets that contain
871 * the class itself and all their subclasses
872 */
874 /** Is given type a subtype of some of the types in given list?
875 */
876 boolean subset(Type t, List<Type> ts) {
877 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
878 if (types.isSubtype(t, l.head)) return true;
879 return false;
880 }
882 /** Is given type a subtype or supertype of
883 * some of the types in given list?
884 */
885 boolean intersects(Type t, List<Type> ts) {
886 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
887 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
888 return false;
889 }
891 /** Add type set to given type list, unless it is a subclass of some class
892 * in the list.
893 */
894 List<Type> incl(Type t, List<Type> ts) {
895 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
896 }
898 /** Remove type set from type set list.
899 */
900 List<Type> excl(Type t, List<Type> ts) {
901 if (ts.isEmpty()) {
902 return ts;
903 } else {
904 List<Type> ts1 = excl(t, ts.tail);
905 if (types.isSubtype(ts.head, t)) return ts1;
906 else if (ts1 == ts.tail) return ts;
907 else return ts1.prepend(ts.head);
908 }
909 }
911 /** Form the union of two type set lists.
912 */
913 List<Type> union(List<Type> ts1, List<Type> ts2) {
914 List<Type> ts = ts1;
915 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
916 ts = incl(l.head, ts);
917 return ts;
918 }
920 /** Form the difference of two type lists.
921 */
922 List<Type> diff(List<Type> ts1, List<Type> ts2) {
923 List<Type> ts = ts1;
924 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
925 ts = excl(l.head, ts);
926 return ts;
927 }
929 /** Form the intersection of two type lists.
930 */
931 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
932 List<Type> ts = List.nil();
933 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
934 if (subset(l.head, ts2)) ts = incl(l.head, ts);
935 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
936 if (subset(l.head, ts1)) ts = incl(l.head, ts);
937 return ts;
938 }
940 /** Is exc an exception symbol that need not be declared?
941 */
942 boolean isUnchecked(ClassSymbol exc) {
943 return
944 exc.kind == ERR ||
945 exc.isSubClass(syms.errorType.tsym, types) ||
946 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
947 }
949 /** Is exc an exception type that need not be declared?
950 */
951 boolean isUnchecked(Type exc) {
952 return
953 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
954 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
955 exc.tag == BOT;
956 }
958 /** Same, but handling completion failures.
959 */
960 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
961 try {
962 return isUnchecked(exc);
963 } catch (CompletionFailure ex) {
964 completionError(pos, ex);
965 return true;
966 }
967 }
969 /** Is exc handled by given exception list?
970 */
971 boolean isHandled(Type exc, List<Type> handled) {
972 return isUnchecked(exc) || subset(exc, handled);
973 }
975 /** Return all exceptions in thrown list that are not in handled list.
976 * @param thrown The list of thrown exceptions.
977 * @param handled The list of handled exceptions.
978 */
979 List<Type> unHandled(List<Type> thrown, List<Type> handled) {
980 List<Type> unhandled = List.nil();
981 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
982 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
983 return unhandled;
984 }
986 /* *************************************************************************
987 * Overriding/Implementation checking
988 **************************************************************************/
990 /** The level of access protection given by a flag set,
991 * where PRIVATE is highest and PUBLIC is lowest.
992 */
993 static int protection(long flags) {
994 switch ((short)(flags & AccessFlags)) {
995 case PRIVATE: return 3;
996 case PROTECTED: return 1;
997 default:
998 case PUBLIC: return 0;
999 case 0: return 2;
1000 }
1001 }
1003 /** A string describing the access permission given by a flag set.
1004 * This always returns a space-separated list of Java Keywords.
1005 */
1006 private static String protectionString(long flags) {
1007 long flags1 = flags & AccessFlags;
1008 return (flags1 == 0) ? "package" : TreeInfo.flagNames(flags1);
1009 }
1011 /** A customized "cannot override" error message.
1012 * @param m The overriding method.
1013 * @param other The overridden method.
1014 * @return An internationalized string.
1015 */
1016 static Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1017 String key;
1018 if ((other.owner.flags() & INTERFACE) == 0)
1019 key = "cant.override";
1020 else if ((m.owner.flags() & INTERFACE) == 0)
1021 key = "cant.implement";
1022 else
1023 key = "clashes.with";
1024 return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
1025 }
1027 /** A customized "override" warning message.
1028 * @param m The overriding method.
1029 * @param other The overridden method.
1030 * @return An internationalized string.
1031 */
1032 static Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1033 String key;
1034 if ((other.owner.flags() & INTERFACE) == 0)
1035 key = "unchecked.override";
1036 else if ((m.owner.flags() & INTERFACE) == 0)
1037 key = "unchecked.implement";
1038 else
1039 key = "unchecked.clash.with";
1040 return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
1041 }
1043 /** A customized "override" warning message.
1044 * @param m The overriding method.
1045 * @param other The overridden method.
1046 * @return An internationalized string.
1047 */
1048 static Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1049 String key;
1050 if ((other.owner.flags() & INTERFACE) == 0)
1051 key = "varargs.override";
1052 else if ((m.owner.flags() & INTERFACE) == 0)
1053 key = "varargs.implement";
1054 else
1055 key = "varargs.clash.with";
1056 return JCDiagnostic.fragment(key, m, m.location(), other, other.location());
1057 }
1059 /** Check that this method conforms with overridden method 'other'.
1060 * where `origin' is the class where checking started.
1061 * Complications:
1062 * (1) Do not check overriding of synthetic methods
1063 * (reason: they might be final).
1064 * todo: check whether this is still necessary.
1065 * (2) Admit the case where an interface proxy throws fewer exceptions
1066 * than the method it implements. Augment the proxy methods with the
1067 * undeclared exceptions in this case.
1068 * (3) When generics are enabled, admit the case where an interface proxy
1069 * has a result type
1070 * extended by the result type of the method it implements.
1071 * Change the proxies result type to the smaller type in this case.
1072 *
1073 * @param tree The tree from which positions
1074 * are extracted for errors.
1075 * @param m The overriding method.
1076 * @param other The overridden method.
1077 * @param origin The class of which the overriding method
1078 * is a member.
1079 */
1080 void checkOverride(JCTree tree,
1081 MethodSymbol m,
1082 MethodSymbol other,
1083 ClassSymbol origin) {
1084 // Don't check overriding of synthetic methods or by bridge methods.
1085 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1086 return;
1087 }
1089 // Error if static method overrides instance method (JLS 8.4.6.2).
1090 if ((m.flags() & STATIC) != 0 &&
1091 (other.flags() & STATIC) == 0) {
1092 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1093 cannotOverride(m, other));
1094 return;
1095 }
1097 // Error if instance method overrides static or final
1098 // method (JLS 8.4.6.1).
1099 if ((other.flags() & FINAL) != 0 ||
1100 (m.flags() & STATIC) == 0 &&
1101 (other.flags() & STATIC) != 0) {
1102 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1103 cannotOverride(m, other),
1104 TreeInfo.flagNames(other.flags() & (FINAL | STATIC)));
1105 return;
1106 }
1108 if ((m.owner.flags() & ANNOTATION) != 0) {
1109 // handled in validateAnnotationMethod
1110 return;
1111 }
1113 // Error if overriding method has weaker access (JLS 8.4.6.3).
1114 if ((origin.flags() & INTERFACE) == 0 &&
1115 protection(m.flags()) > protection(other.flags())) {
1116 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1117 cannotOverride(m, other),
1118 protectionString(other.flags()));
1119 return;
1121 }
1123 Type mt = types.memberType(origin.type, m);
1124 Type ot = types.memberType(origin.type, other);
1125 // Error if overriding result type is different
1126 // (or, in the case of generics mode, not a subtype) of
1127 // overridden result type. We have to rename any type parameters
1128 // before comparing types.
1129 List<Type> mtvars = mt.getTypeArguments();
1130 List<Type> otvars = ot.getTypeArguments();
1131 Type mtres = mt.getReturnType();
1132 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1134 overrideWarner.warned = false;
1135 boolean resultTypesOK =
1136 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1137 if (!resultTypesOK) {
1138 if (!source.allowCovariantReturns() &&
1139 m.owner != origin &&
1140 m.owner.isSubClass(other.owner, types)) {
1141 // allow limited interoperability with covariant returns
1142 } else {
1143 typeError(TreeInfo.diagnosticPositionFor(m, tree),
1144 JCDiagnostic.fragment("override.incompatible.ret",
1145 cannotOverride(m, other)),
1146 mtres, otres);
1147 return;
1148 }
1149 } else if (overrideWarner.warned) {
1150 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1151 "prob.found.req",
1152 JCDiagnostic.fragment("override.unchecked.ret",
1153 uncheckedOverrides(m, other)),
1154 mtres, otres);
1155 }
1157 // Error if overriding method throws an exception not reported
1158 // by overridden method.
1159 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1160 List<Type> unhandled = unHandled(mt.getThrownTypes(), otthrown);
1161 if (unhandled.nonEmpty()) {
1162 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1163 "override.meth.doesnt.throw",
1164 cannotOverride(m, other),
1165 unhandled.head);
1166 return;
1167 }
1169 // Optional warning if varargs don't agree
1170 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1171 && lint.isEnabled(Lint.LintCategory.OVERRIDES)) {
1172 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1173 ((m.flags() & Flags.VARARGS) != 0)
1174 ? "override.varargs.missing"
1175 : "override.varargs.extra",
1176 varargsOverrides(m, other));
1177 }
1179 // Warn if instance method overrides bridge method (compiler spec ??)
1180 if ((other.flags() & BRIDGE) != 0) {
1181 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1182 uncheckedOverrides(m, other));
1183 }
1185 // Warn if a deprecated method overridden by a non-deprecated one.
1186 if ((other.flags() & DEPRECATED) != 0
1187 && (m.flags() & DEPRECATED) == 0
1188 && m.outermostClass() != other.outermostClass()
1189 && !isDeprecatedOverrideIgnorable(other, origin)) {
1190 warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
1191 }
1192 }
1193 // where
1194 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1195 // If the method, m, is defined in an interface, then ignore the issue if the method
1196 // is only inherited via a supertype and also implemented in the supertype,
1197 // because in that case, we will rediscover the issue when examining the method
1198 // in the supertype.
1199 // If the method, m, is not defined in an interface, then the only time we need to
1200 // address the issue is when the method is the supertype implemementation: any other
1201 // case, we will have dealt with when examining the supertype classes
1202 ClassSymbol mc = m.enclClass();
1203 Type st = types.supertype(origin.type);
1204 if (st.tag != CLASS)
1205 return true;
1206 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1208 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1209 List<Type> intfs = types.interfaces(origin.type);
1210 return (intfs.contains(mc.type) ? false : (stimpl != null));
1211 }
1212 else
1213 return (stimpl != m);
1214 }
1217 // used to check if there were any unchecked conversions
1218 Warner overrideWarner = new Warner();
1220 /** Check that a class does not inherit two concrete methods
1221 * with the same signature.
1222 * @param pos Position to be used for error reporting.
1223 * @param site The class type to be checked.
1224 */
1225 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1226 Type sup = types.supertype(site);
1227 if (sup.tag != CLASS) return;
1229 for (Type t1 = sup;
1230 t1.tsym.type.isParameterized();
1231 t1 = types.supertype(t1)) {
1232 for (Scope.Entry e1 = t1.tsym.members().elems;
1233 e1 != null;
1234 e1 = e1.sibling) {
1235 Symbol s1 = e1.sym;
1236 if (s1.kind != MTH ||
1237 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1238 !s1.isInheritedIn(site.tsym, types) ||
1239 ((MethodSymbol)s1).implementation(site.tsym,
1240 types,
1241 true) != s1)
1242 continue;
1243 Type st1 = types.memberType(t1, s1);
1244 int s1ArgsLength = st1.getParameterTypes().length();
1245 if (st1 == s1.type) continue;
1247 for (Type t2 = sup;
1248 t2.tag == CLASS;
1249 t2 = types.supertype(t2)) {
1250 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1251 e2.scope != null;
1252 e2 = e2.next()) {
1253 Symbol s2 = e2.sym;
1254 if (s2 == s1 ||
1255 s2.kind != MTH ||
1256 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1257 s2.type.getParameterTypes().length() != s1ArgsLength ||
1258 !s2.isInheritedIn(site.tsym, types) ||
1259 ((MethodSymbol)s2).implementation(site.tsym,
1260 types,
1261 true) != s2)
1262 continue;
1263 Type st2 = types.memberType(t2, s2);
1264 if (types.overrideEquivalent(st1, st2))
1265 log.error(pos, "concrete.inheritance.conflict",
1266 s1, t1, s2, t2, sup);
1267 }
1268 }
1269 }
1270 }
1271 }
1273 /** Check that classes (or interfaces) do not each define an abstract
1274 * method with same name and arguments but incompatible return types.
1275 * @param pos Position to be used for error reporting.
1276 * @param t1 The first argument type.
1277 * @param t2 The second argument type.
1278 */
1279 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1280 Type t1,
1281 Type t2) {
1282 return checkCompatibleAbstracts(pos, t1, t2,
1283 types.makeCompoundType(t1, t2));
1284 }
1286 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1287 Type t1,
1288 Type t2,
1289 Type site) {
1290 Symbol sym = firstIncompatibility(t1, t2, site);
1291 if (sym != null) {
1292 log.error(pos, "types.incompatible.diff.ret",
1293 t1, t2, sym.name +
1294 "(" + types.memberType(t2, sym).getParameterTypes() + ")");
1295 return false;
1296 }
1297 return true;
1298 }
1300 /** Return the first method which is defined with same args
1301 * but different return types in two given interfaces, or null if none
1302 * exists.
1303 * @param t1 The first type.
1304 * @param t2 The second type.
1305 * @param site The most derived type.
1306 * @returns symbol from t2 that conflicts with one in t1.
1307 */
1308 private Symbol firstIncompatibility(Type t1, Type t2, Type site) {
1309 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1310 closure(t1, interfaces1);
1311 Map<TypeSymbol,Type> interfaces2;
1312 if (t1 == t2)
1313 interfaces2 = interfaces1;
1314 else
1315 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1317 for (Type t3 : interfaces1.values()) {
1318 for (Type t4 : interfaces2.values()) {
1319 Symbol s = firstDirectIncompatibility(t3, t4, site);
1320 if (s != null) return s;
1321 }
1322 }
1323 return null;
1324 }
1326 /** Compute all the supertypes of t, indexed by type symbol. */
1327 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1328 if (t.tag != CLASS) return;
1329 if (typeMap.put(t.tsym, t) == null) {
1330 closure(types.supertype(t), typeMap);
1331 for (Type i : types.interfaces(t))
1332 closure(i, typeMap);
1333 }
1334 }
1336 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1337 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1338 if (t.tag != CLASS) return;
1339 if (typesSkip.get(t.tsym) != null) return;
1340 if (typeMap.put(t.tsym, t) == null) {
1341 closure(types.supertype(t), typesSkip, typeMap);
1342 for (Type i : types.interfaces(t))
1343 closure(i, typesSkip, typeMap);
1344 }
1345 }
1347 /** Return the first method in t2 that conflicts with a method from t1. */
1348 private Symbol firstDirectIncompatibility(Type t1, Type t2, Type site) {
1349 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1350 Symbol s1 = e1.sym;
1351 Type st1 = null;
1352 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1353 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1354 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1355 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1356 Symbol s2 = e2.sym;
1357 if (s1 == s2) continue;
1358 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1359 if (st1 == null) st1 = types.memberType(t1, s1);
1360 Type st2 = types.memberType(t2, s2);
1361 if (types.overrideEquivalent(st1, st2)) {
1362 List<Type> tvars1 = st1.getTypeArguments();
1363 List<Type> tvars2 = st2.getTypeArguments();
1364 Type rt1 = st1.getReturnType();
1365 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1366 boolean compat =
1367 types.isSameType(rt1, rt2) ||
1368 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1369 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1370 types.covariantReturnType(rt2, rt1, Warner.noWarnings));
1371 if (!compat) return s2;
1372 }
1373 }
1374 }
1375 return null;
1376 }
1378 /** Check that a given method conforms with any method it overrides.
1379 * @param tree The tree from which positions are extracted
1380 * for errors.
1381 * @param m The overriding method.
1382 */
1383 void checkOverride(JCTree tree, MethodSymbol m) {
1384 ClassSymbol origin = (ClassSymbol)m.owner;
1385 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1386 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1387 log.error(tree.pos(), "enum.no.finalize");
1388 return;
1389 }
1390 for (Type t = types.supertype(origin.type); t.tag == CLASS;
1391 t = types.supertype(t)) {
1392 TypeSymbol c = t.tsym;
1393 Scope.Entry e = c.members().lookup(m.name);
1394 while (e.scope != null) {
1395 if (m.overrides(e.sym, origin, types, false))
1396 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1397 else if (e.sym.isInheritedIn(origin, types) && !m.isConstructor()) {
1398 Type er1 = m.erasure(types);
1399 Type er2 = e.sym.erasure(types);
1400 if (types.isSameType(er1,er2)) {
1401 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1402 "name.clash.same.erasure.no.override",
1403 m, m.location(),
1404 e.sym, e.sym.location());
1405 }
1406 }
1407 e = e.next();
1408 }
1409 }
1410 }
1412 /** Check that all abstract members of given class have definitions.
1413 * @param pos Position to be used for error reporting.
1414 * @param c The class.
1415 */
1416 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1417 try {
1418 MethodSymbol undef = firstUndef(c, c);
1419 if (undef != null) {
1420 if ((c.flags() & ENUM) != 0 &&
1421 types.supertype(c.type).tsym == syms.enumSym &&
1422 (c.flags() & FINAL) == 0) {
1423 // add the ABSTRACT flag to an enum
1424 c.flags_field |= ABSTRACT;
1425 } else {
1426 MethodSymbol undef1 =
1427 new MethodSymbol(undef.flags(), undef.name,
1428 types.memberType(c.type, undef), undef.owner);
1429 log.error(pos, "does.not.override.abstract",
1430 c, undef1, undef1.location());
1431 }
1432 }
1433 } catch (CompletionFailure ex) {
1434 completionError(pos, ex);
1435 }
1436 }
1437 //where
1438 /** Return first abstract member of class `c' that is not defined
1439 * in `impl', null if there is none.
1440 */
1441 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1442 MethodSymbol undef = null;
1443 // Do not bother to search in classes that are not abstract,
1444 // since they cannot have abstract members.
1445 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1446 Scope s = c.members();
1447 for (Scope.Entry e = s.elems;
1448 undef == null && e != null;
1449 e = e.sibling) {
1450 if (e.sym.kind == MTH &&
1451 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1452 MethodSymbol absmeth = (MethodSymbol)e.sym;
1453 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1454 if (implmeth == null || implmeth == absmeth)
1455 undef = absmeth;
1456 }
1457 }
1458 if (undef == null) {
1459 Type st = types.supertype(c.type);
1460 if (st.tag == CLASS)
1461 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1462 }
1463 for (List<Type> l = types.interfaces(c.type);
1464 undef == null && l.nonEmpty();
1465 l = l.tail) {
1466 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1467 }
1468 }
1469 return undef;
1470 }
1472 /** Check for cyclic references. Issue an error if the
1473 * symbol of the type referred to has a LOCKED flag set.
1474 *
1475 * @param pos Position to be used for error reporting.
1476 * @param t The type referred to.
1477 */
1478 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1479 checkNonCyclicInternal(pos, t);
1480 }
1483 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1484 checkNonCyclic1(pos, t, new HashSet<TypeVar>());
1485 }
1487 private void checkNonCyclic1(DiagnosticPosition pos, Type t, Set<TypeVar> seen) {
1488 final TypeVar tv;
1489 if (seen.contains(t)) {
1490 tv = (TypeVar)t;
1491 tv.bound = new ErrorType();
1492 log.error(pos, "cyclic.inheritance", t);
1493 } else if (t.tag == TYPEVAR) {
1494 tv = (TypeVar)t;
1495 seen.add(tv);
1496 for (Type b : types.getBounds(tv))
1497 checkNonCyclic1(pos, b, seen);
1498 }
1499 }
1501 /** Check for cyclic references. Issue an error if the
1502 * symbol of the type referred to has a LOCKED flag set.
1503 *
1504 * @param pos Position to be used for error reporting.
1505 * @param t The type referred to.
1506 * @returns True if the check completed on all attributed classes
1507 */
1508 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1509 boolean complete = true; // was the check complete?
1510 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1511 Symbol c = t.tsym;
1512 if ((c.flags_field & ACYCLIC) != 0) return true;
1514 if ((c.flags_field & LOCKED) != 0) {
1515 noteCyclic(pos, (ClassSymbol)c);
1516 } else if (!c.type.isErroneous()) {
1517 try {
1518 c.flags_field |= LOCKED;
1519 if (c.type.tag == CLASS) {
1520 ClassType clazz = (ClassType)c.type;
1521 if (clazz.interfaces_field != null)
1522 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1523 complete &= checkNonCyclicInternal(pos, l.head);
1524 if (clazz.supertype_field != null) {
1525 Type st = clazz.supertype_field;
1526 if (st != null && st.tag == CLASS)
1527 complete &= checkNonCyclicInternal(pos, st);
1528 }
1529 if (c.owner.kind == TYP)
1530 complete &= checkNonCyclicInternal(pos, c.owner.type);
1531 }
1532 } finally {
1533 c.flags_field &= ~LOCKED;
1534 }
1535 }
1536 if (complete)
1537 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1538 if (complete) c.flags_field |= ACYCLIC;
1539 return complete;
1540 }
1542 /** Note that we found an inheritance cycle. */
1543 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1544 log.error(pos, "cyclic.inheritance", c);
1545 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1546 l.head = new ErrorType((ClassSymbol)l.head.tsym);
1547 Type st = types.supertype(c.type);
1548 if (st.tag == CLASS)
1549 ((ClassType)c.type).supertype_field = new ErrorType((ClassSymbol)st.tsym);
1550 c.type = new ErrorType(c);
1551 c.flags_field |= ACYCLIC;
1552 }
1554 /** Check that all methods which implement some
1555 * method conform to the method they implement.
1556 * @param tree The class definition whose members are checked.
1557 */
1558 void checkImplementations(JCClassDecl tree) {
1559 checkImplementations(tree, tree.sym);
1560 }
1561 //where
1562 /** Check that all methods which implement some
1563 * method in `ic' conform to the method they implement.
1564 */
1565 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
1566 ClassSymbol origin = tree.sym;
1567 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
1568 ClassSymbol lc = (ClassSymbol)l.head.tsym;
1569 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
1570 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
1571 if (e.sym.kind == MTH &&
1572 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
1573 MethodSymbol absmeth = (MethodSymbol)e.sym;
1574 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
1575 if (implmeth != null && implmeth != absmeth &&
1576 (implmeth.owner.flags() & INTERFACE) ==
1577 (origin.flags() & INTERFACE)) {
1578 // don't check if implmeth is in a class, yet
1579 // origin is an interface. This case arises only
1580 // if implmeth is declared in Object. The reason is
1581 // that interfaces really don't inherit from
1582 // Object it's just that the compiler represents
1583 // things that way.
1584 checkOverride(tree, implmeth, absmeth, origin);
1585 }
1586 }
1587 }
1588 }
1589 }
1590 }
1592 /** Check that all abstract methods implemented by a class are
1593 * mutually compatible.
1594 * @param pos Position to be used for error reporting.
1595 * @param c The class whose interfaces are checked.
1596 */
1597 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
1598 List<Type> supertypes = types.interfaces(c);
1599 Type supertype = types.supertype(c);
1600 if (supertype.tag == CLASS &&
1601 (supertype.tsym.flags() & ABSTRACT) != 0)
1602 supertypes = supertypes.prepend(supertype);
1603 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
1604 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
1605 !checkCompatibleAbstracts(pos, l.head, l.head, c))
1606 return;
1607 for (List<Type> m = supertypes; m != l; m = m.tail)
1608 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
1609 return;
1610 }
1611 checkCompatibleConcretes(pos, c);
1612 }
1614 /** Check that class c does not implement directly or indirectly
1615 * the same parameterized interface with two different argument lists.
1616 * @param pos Position to be used for error reporting.
1617 * @param type The type whose interfaces are checked.
1618 */
1619 void checkClassBounds(DiagnosticPosition pos, Type type) {
1620 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
1621 }
1622 //where
1623 /** Enter all interfaces of type `type' into the hash table `seensofar'
1624 * with their class symbol as key and their type as value. Make
1625 * sure no class is entered with two different types.
1626 */
1627 void checkClassBounds(DiagnosticPosition pos,
1628 Map<TypeSymbol,Type> seensofar,
1629 Type type) {
1630 if (type.isErroneous()) return;
1631 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
1632 Type it = l.head;
1633 Type oldit = seensofar.put(it.tsym, it);
1634 if (oldit != null) {
1635 List<Type> oldparams = oldit.allparams();
1636 List<Type> newparams = it.allparams();
1637 if (!types.containsTypeEquivalent(oldparams, newparams))
1638 log.error(pos, "cant.inherit.diff.arg",
1639 it.tsym, Type.toString(oldparams),
1640 Type.toString(newparams));
1641 }
1642 checkClassBounds(pos, seensofar, it);
1643 }
1644 Type st = types.supertype(type);
1645 if (st != null) checkClassBounds(pos, seensofar, st);
1646 }
1648 /** Enter interface into into set.
1649 * If it existed already, issue a "repeated interface" error.
1650 */
1651 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
1652 if (its.contains(it))
1653 log.error(pos, "repeated.interface");
1654 else {
1655 its.add(it);
1656 }
1657 }
1659 /* *************************************************************************
1660 * Check annotations
1661 **************************************************************************/
1663 /** Annotation types are restricted to primitives, String, an
1664 * enum, an annotation, Class, Class<?>, Class<? extends
1665 * Anything>, arrays of the preceding.
1666 */
1667 void validateAnnotationType(JCTree restype) {
1668 // restype may be null if an error occurred, so don't bother validating it
1669 if (restype != null) {
1670 validateAnnotationType(restype.pos(), restype.type);
1671 }
1672 }
1674 void validateAnnotationType(DiagnosticPosition pos, Type type) {
1675 if (type.isPrimitive()) return;
1676 if (types.isSameType(type, syms.stringType)) return;
1677 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
1678 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
1679 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
1680 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
1681 validateAnnotationType(pos, types.elemtype(type));
1682 return;
1683 }
1684 log.error(pos, "invalid.annotation.member.type");
1685 }
1687 /**
1688 * "It is also a compile-time error if any method declared in an
1689 * annotation type has a signature that is override-equivalent to
1690 * that of any public or protected method declared in class Object
1691 * or in the interface annotation.Annotation."
1692 *
1693 * @jls3 9.6 Annotation Types
1694 */
1695 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
1696 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
1697 Scope s = sup.tsym.members();
1698 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
1699 if (e.sym.kind == MTH &&
1700 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
1701 types.overrideEquivalent(m.type, e.sym.type))
1702 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
1703 }
1704 }
1705 }
1707 /** Check the annotations of a symbol.
1708 */
1709 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
1710 if (skipAnnotations) return;
1711 for (JCAnnotation a : annotations)
1712 validateAnnotation(a, s);
1713 }
1715 /** Check an annotation of a symbol.
1716 */
1717 public void validateAnnotation(JCAnnotation a, Symbol s) {
1718 validateAnnotation(a);
1720 if (!annotationApplicable(a, s))
1721 log.error(a.pos(), "annotation.type.not.applicable");
1723 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
1724 if (!isOverrider(s))
1725 log.error(a.pos(), "method.does.not.override.superclass");
1726 }
1727 }
1729 /** Is s a method symbol that overrides a method in a superclass? */
1730 boolean isOverrider(Symbol s) {
1731 if (s.kind != MTH || s.isStatic())
1732 return false;
1733 MethodSymbol m = (MethodSymbol)s;
1734 TypeSymbol owner = (TypeSymbol)m.owner;
1735 for (Type sup : types.closure(owner.type)) {
1736 if (sup == owner.type)
1737 continue; // skip "this"
1738 Scope scope = sup.tsym.members();
1739 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
1740 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
1741 return true;
1742 }
1743 }
1744 return false;
1745 }
1747 /** Is the annotation applicable to the symbol? */
1748 boolean annotationApplicable(JCAnnotation a, Symbol s) {
1749 Attribute.Compound atTarget =
1750 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
1751 if (atTarget == null) return true;
1752 Attribute atValue = atTarget.member(names.value);
1753 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
1754 Attribute.Array arr = (Attribute.Array) atValue;
1755 for (Attribute app : arr.values) {
1756 if (!(app instanceof Attribute.Enum)) return true; // recovery
1757 Attribute.Enum e = (Attribute.Enum) app;
1758 if (e.value.name == names.TYPE)
1759 { if (s.kind == TYP) return true; }
1760 else if (e.value.name == names.FIELD)
1761 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
1762 else if (e.value.name == names.METHOD)
1763 { if (s.kind == MTH && !s.isConstructor()) return true; }
1764 else if (e.value.name == names.PARAMETER)
1765 { if (s.kind == VAR &&
1766 s.owner.kind == MTH &&
1767 (s.flags() & PARAMETER) != 0)
1768 return true;
1769 }
1770 else if (e.value.name == names.CONSTRUCTOR)
1771 { if (s.kind == MTH && s.isConstructor()) return true; }
1772 else if (e.value.name == names.LOCAL_VARIABLE)
1773 { if (s.kind == VAR && s.owner.kind == MTH &&
1774 (s.flags() & PARAMETER) == 0)
1775 return true;
1776 }
1777 else if (e.value.name == names.ANNOTATION_TYPE)
1778 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
1779 return true;
1780 }
1781 else if (e.value.name == names.PACKAGE)
1782 { if (s.kind == PCK) return true; }
1783 else
1784 return true; // recovery
1785 }
1786 return false;
1787 }
1789 /** Check an annotation value.
1790 */
1791 public void validateAnnotation(JCAnnotation a) {
1792 if (a.type.isErroneous()) return;
1794 // collect an inventory of the members
1795 Set<MethodSymbol> members = new HashSet<MethodSymbol>();
1796 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
1797 e != null;
1798 e = e.sibling)
1799 if (e.sym.kind == MTH)
1800 members.add((MethodSymbol) e.sym);
1802 // count them off as they're annotated
1803 for (JCTree arg : a.args) {
1804 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
1805 JCAssign assign = (JCAssign) arg;
1806 Symbol m = TreeInfo.symbol(assign.lhs);
1807 if (m == null || m.type.isErroneous()) continue;
1808 if (!members.remove(m))
1809 log.error(arg.pos(), "duplicate.annotation.member.value",
1810 m.name, a.type);
1811 if (assign.rhs.getTag() == ANNOTATION)
1812 validateAnnotation((JCAnnotation)assign.rhs);
1813 }
1815 // all the remaining ones better have default values
1816 for (MethodSymbol m : members)
1817 if (m.defaultValue == null && !m.type.isErroneous())
1818 log.error(a.pos(), "annotation.missing.default.value",
1819 a.type, m.name);
1821 // special case: java.lang.annotation.Target must not have
1822 // repeated values in its value member
1823 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
1824 a.args.tail == null)
1825 return;
1827 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
1828 JCAssign assign = (JCAssign) a.args.head;
1829 Symbol m = TreeInfo.symbol(assign.lhs);
1830 if (m.name != names.value) return;
1831 JCTree rhs = assign.rhs;
1832 if (rhs.getTag() != JCTree.NEWARRAY) return;
1833 JCNewArray na = (JCNewArray) rhs;
1834 Set<Symbol> targets = new HashSet<Symbol>();
1835 for (JCTree elem : na.elems) {
1836 if (!targets.add(TreeInfo.symbol(elem))) {
1837 log.error(elem.pos(), "repeated.annotation.target");
1838 }
1839 }
1840 }
1842 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
1843 if (allowAnnotations &&
1844 lint.isEnabled(Lint.LintCategory.DEP_ANN) &&
1845 (s.flags() & DEPRECATED) != 0 &&
1846 !syms.deprecatedType.isErroneous() &&
1847 s.attribute(syms.deprecatedType.tsym) == null) {
1848 log.warning(pos, "missing.deprecated.annotation");
1849 }
1850 }
1852 /* *************************************************************************
1853 * Check for recursive annotation elements.
1854 **************************************************************************/
1856 /** Check for cycles in the graph of annotation elements.
1857 */
1858 void checkNonCyclicElements(JCClassDecl tree) {
1859 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
1860 assert (tree.sym.flags_field & LOCKED) == 0;
1861 try {
1862 tree.sym.flags_field |= LOCKED;
1863 for (JCTree def : tree.defs) {
1864 if (def.getTag() != JCTree.METHODDEF) continue;
1865 JCMethodDecl meth = (JCMethodDecl)def;
1866 checkAnnotationResType(meth.pos(), meth.restype.type);
1867 }
1868 } finally {
1869 tree.sym.flags_field &= ~LOCKED;
1870 tree.sym.flags_field |= ACYCLIC_ANN;
1871 }
1872 }
1874 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
1875 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
1876 return;
1877 if ((tsym.flags_field & LOCKED) != 0) {
1878 log.error(pos, "cyclic.annotation.element");
1879 return;
1880 }
1881 try {
1882 tsym.flags_field |= LOCKED;
1883 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
1884 Symbol s = e.sym;
1885 if (s.kind != Kinds.MTH)
1886 continue;
1887 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
1888 }
1889 } finally {
1890 tsym.flags_field &= ~LOCKED;
1891 tsym.flags_field |= ACYCLIC_ANN;
1892 }
1893 }
1895 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
1896 switch (type.tag) {
1897 case TypeTags.CLASS:
1898 if ((type.tsym.flags() & ANNOTATION) != 0)
1899 checkNonCyclicElementsInternal(pos, type.tsym);
1900 break;
1901 case TypeTags.ARRAY:
1902 checkAnnotationResType(pos, types.elemtype(type));
1903 break;
1904 default:
1905 break; // int etc
1906 }
1907 }
1909 /* *************************************************************************
1910 * Check for cycles in the constructor call graph.
1911 **************************************************************************/
1913 /** Check for cycles in the graph of constructors calling other
1914 * constructors.
1915 */
1916 void checkCyclicConstructors(JCClassDecl tree) {
1917 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
1919 // enter each constructor this-call into the map
1920 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
1921 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
1922 if (app == null) continue;
1923 JCMethodDecl meth = (JCMethodDecl) l.head;
1924 if (TreeInfo.name(app.meth) == names._this) {
1925 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
1926 } else {
1927 meth.sym.flags_field |= ACYCLIC;
1928 }
1929 }
1931 // Check for cycles in the map
1932 Symbol[] ctors = new Symbol[0];
1933 ctors = callMap.keySet().toArray(ctors);
1934 for (Symbol caller : ctors) {
1935 checkCyclicConstructor(tree, caller, callMap);
1936 }
1937 }
1939 /** Look in the map to see if the given constructor is part of a
1940 * call cycle.
1941 */
1942 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
1943 Map<Symbol,Symbol> callMap) {
1944 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
1945 if ((ctor.flags_field & LOCKED) != 0) {
1946 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
1947 "recursive.ctor.invocation");
1948 } else {
1949 ctor.flags_field |= LOCKED;
1950 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
1951 ctor.flags_field &= ~LOCKED;
1952 }
1953 ctor.flags_field |= ACYCLIC;
1954 }
1955 }
1957 /* *************************************************************************
1958 * Miscellaneous
1959 **************************************************************************/
1961 /**
1962 * Return the opcode of the operator but emit an error if it is an
1963 * error.
1964 * @param pos position for error reporting.
1965 * @param operator an operator
1966 * @param tag a tree tag
1967 * @param left type of left hand side
1968 * @param right type of right hand side
1969 */
1970 int checkOperator(DiagnosticPosition pos,
1971 OperatorSymbol operator,
1972 int tag,
1973 Type left,
1974 Type right) {
1975 if (operator.opcode == ByteCodes.error) {
1976 log.error(pos,
1977 "operator.cant.be.applied",
1978 treeinfo.operatorName(tag),
1979 left + "," + right);
1980 }
1981 return operator.opcode;
1982 }
1985 /**
1986 * Check for division by integer constant zero
1987 * @param pos Position for error reporting.
1988 * @param operator The operator for the expression
1989 * @param operand The right hand operand for the expression
1990 */
1991 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
1992 if (operand.constValue() != null
1993 && lint.isEnabled(Lint.LintCategory.DIVZERO)
1994 && operand.tag <= LONG
1995 && ((Number) (operand.constValue())).longValue() == 0) {
1996 int opc = ((OperatorSymbol)operator).opcode;
1997 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
1998 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
1999 log.warning(pos, "div.zero");
2000 }
2001 }
2002 }
2004 /**
2005 * Check for empty statements after if
2006 */
2007 void checkEmptyIf(JCIf tree) {
2008 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(Lint.LintCategory.EMPTY))
2009 log.warning(tree.thenpart.pos(), "empty.if");
2010 }
2012 /** Check that symbol is unique in given scope.
2013 * @param pos Position for error reporting.
2014 * @param sym The symbol.
2015 * @param s The scope.
2016 */
2017 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2018 if (sym.type.isErroneous())
2019 return true;
2020 if (sym.owner.name == names.any) return false;
2021 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2022 if (sym != e.sym &&
2023 sym.kind == e.sym.kind &&
2024 sym.name != names.error &&
2025 (sym.kind != MTH || types.overrideEquivalent(sym.type, e.sym.type))) {
2026 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
2027 varargsDuplicateError(pos, sym, e.sym);
2028 else
2029 duplicateError(pos, e.sym);
2030 return false;
2031 }
2032 }
2033 return true;
2034 }
2036 /** Check that single-type import is not already imported or top-level defined,
2037 * but make an exception for two single-type imports which denote the same type.
2038 * @param pos Position for error reporting.
2039 * @param sym The symbol.
2040 * @param s The scope
2041 */
2042 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2043 return checkUniqueImport(pos, sym, s, false);
2044 }
2046 /** Check that static single-type import is not already imported or top-level defined,
2047 * but make an exception for two single-type imports which denote the same type.
2048 * @param pos Position for error reporting.
2049 * @param sym The symbol.
2050 * @param s The scope
2051 * @param staticImport Whether or not this was a static import
2052 */
2053 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2054 return checkUniqueImport(pos, sym, s, true);
2055 }
2057 /** Check that single-type import is not already imported or top-level defined,
2058 * but make an exception for two single-type imports which denote the same type.
2059 * @param pos Position for error reporting.
2060 * @param sym The symbol.
2061 * @param s The scope.
2062 * @param staticImport Whether or not this was a static import
2063 */
2064 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2065 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2066 // is encountered class entered via a class declaration?
2067 boolean isClassDecl = e.scope == s;
2068 if ((isClassDecl || sym != e.sym) &&
2069 sym.kind == e.sym.kind &&
2070 sym.name != names.error) {
2071 if (!e.sym.type.isErroneous()) {
2072 String what = e.sym.toString();
2073 if (!isClassDecl) {
2074 if (staticImport)
2075 log.error(pos, "already.defined.static.single.import", what);
2076 else
2077 log.error(pos, "already.defined.single.import", what);
2078 }
2079 else if (sym != e.sym)
2080 log.error(pos, "already.defined.this.unit", what);
2081 }
2082 return false;
2083 }
2084 }
2085 return true;
2086 }
2088 /** Check that a qualified name is in canonical form (for import decls).
2089 */
2090 public void checkCanonical(JCTree tree) {
2091 if (!isCanonical(tree))
2092 log.error(tree.pos(), "import.requires.canonical",
2093 TreeInfo.symbol(tree));
2094 }
2095 // where
2096 private boolean isCanonical(JCTree tree) {
2097 while (tree.getTag() == JCTree.SELECT) {
2098 JCFieldAccess s = (JCFieldAccess) tree;
2099 if (s.sym.owner != TreeInfo.symbol(s.selected))
2100 return false;
2101 tree = s.selected;
2102 }
2103 return true;
2104 }
2106 private class ConversionWarner extends Warner {
2107 final String key;
2108 final Type found;
2109 final Type expected;
2110 public ConversionWarner(DiagnosticPosition pos, String key, Type found, Type expected) {
2111 super(pos);
2112 this.key = key;
2113 this.found = found;
2114 this.expected = expected;
2115 }
2117 public void warnUnchecked() {
2118 boolean warned = this.warned;
2119 super.warnUnchecked();
2120 if (warned) return; // suppress redundant diagnostics
2121 Object problem = JCDiagnostic.fragment(key);
2122 Check.this.warnUnchecked(pos(), "prob.found.req", problem, found, expected);
2123 }
2124 }
2126 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2127 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2128 }
2130 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2131 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2132 }
2133 }