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src/share/classes/com/sun/tools/javac/comp/Check.java@4868a36f6fd8
src/share/classes/com/sun/tools/javac/comp/Check.java
Tue, 28 Dec 2010 15:54:52 -0800
- author
- ohair
- date
- Tue, 28 Dec 2010 15:54:52 -0800
- changeset 798
- 4868a36f6fd8
- parent 795
- 7b99f98b3035
- child 815
- d17f37522154
- permissions
- -rw-r--r--
6962318: Update copyright year
Reviewed-by: xdono
1 /*
2 * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
26 package com.sun.tools.javac.comp;
28 import 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 import static com.sun.tools.javac.main.OptionName.*;
50 /** Type checking helper class for the attribution phase.
51 *
52 * <p><b>This is NOT part of any supported API.
53 * If you write code that depends on this, you do so at your own risk.
54 * This code and its internal interfaces are subject to change or
55 * deletion without notice.</b>
56 */
57 public class Check {
58 protected static final Context.Key<Check> checkKey =
59 new Context.Key<Check>();
61 private final Names names;
62 private final Log log;
63 private final Symtab syms;
64 private final Enter enter;
65 private final Infer infer;
66 private final Types types;
67 private final JCDiagnostic.Factory diags;
68 private final boolean skipAnnotations;
69 private boolean warnOnSyntheticConflicts;
70 private boolean suppressAbortOnBadClassFile;
71 private final TreeInfo treeinfo;
73 // The set of lint options currently in effect. It is initialized
74 // from the context, and then is set/reset as needed by Attr as it
75 // visits all the various parts of the trees during attribution.
76 private Lint lint;
78 // The method being analyzed in Attr - it is set/reset as needed by
79 // Attr as it visits new method declarations.
80 private MethodSymbol method;
82 public static Check instance(Context context) {
83 Check instance = context.get(checkKey);
84 if (instance == null)
85 instance = new Check(context);
86 return instance;
87 }
89 protected Check(Context context) {
90 context.put(checkKey, this);
92 names = Names.instance(context);
93 log = Log.instance(context);
94 syms = Symtab.instance(context);
95 enter = Enter.instance(context);
96 infer = Infer.instance(context);
97 this.types = Types.instance(context);
98 diags = JCDiagnostic.Factory.instance(context);
99 Options options = Options.instance(context);
100 lint = Lint.instance(context);
101 treeinfo = TreeInfo.instance(context);
103 Source source = Source.instance(context);
104 allowGenerics = source.allowGenerics();
105 allowAnnotations = source.allowAnnotations();
106 allowCovariantReturns = source.allowCovariantReturns();
107 allowSimplifiedVarargs = source.allowSimplifiedVarargs();
108 complexInference = options.isSet(COMPLEXINFERENCE);
109 skipAnnotations = options.isSet("skipAnnotations");
110 warnOnSyntheticConflicts = options.isSet("warnOnSyntheticConflicts");
111 suppressAbortOnBadClassFile = options.isSet("suppressAbortOnBadClassFile");
113 Target target = Target.instance(context);
114 syntheticNameChar = target.syntheticNameChar();
116 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
117 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
118 boolean verboseVarargs = lint.isEnabled(LintCategory.VARARGS);
119 boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
120 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
122 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
123 enforceMandatoryWarnings, "deprecated", LintCategory.DEPRECATION);
124 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
125 enforceMandatoryWarnings, "unchecked", LintCategory.UNCHECKED);
126 unsafeVarargsHandler = new MandatoryWarningHandler(log, verboseVarargs,
127 enforceMandatoryWarnings, "varargs", LintCategory.VARARGS);
128 sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
129 enforceMandatoryWarnings, "sunapi", null);
130 }
132 /** Switch: generics enabled?
133 */
134 boolean allowGenerics;
136 /** Switch: annotations enabled?
137 */
138 boolean allowAnnotations;
140 /** Switch: covariant returns enabled?
141 */
142 boolean allowCovariantReturns;
144 /** Switch: simplified varargs enabled?
145 */
146 boolean allowSimplifiedVarargs;
148 /** Switch: -complexinference option set?
149 */
150 boolean complexInference;
152 /** Character for synthetic names
153 */
154 char syntheticNameChar;
156 /** A table mapping flat names of all compiled classes in this run to their
157 * symbols; maintained from outside.
158 */
159 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
161 /** A handler for messages about deprecated usage.
162 */
163 private MandatoryWarningHandler deprecationHandler;
165 /** A handler for messages about unchecked or unsafe usage.
166 */
167 private MandatoryWarningHandler uncheckedHandler;
169 /** A handler for messages about unchecked or unsafe vararg method decl.
170 */
171 private MandatoryWarningHandler unsafeVarargsHandler;
173 /** A handler for messages about using proprietary API.
174 */
175 private MandatoryWarningHandler sunApiHandler;
177 /* *************************************************************************
178 * Errors and Warnings
179 **************************************************************************/
181 Lint setLint(Lint newLint) {
182 Lint prev = lint;
183 lint = newLint;
184 return prev;
185 }
187 MethodSymbol setMethod(MethodSymbol newMethod) {
188 MethodSymbol prev = method;
189 method = newMethod;
190 return prev;
191 }
193 /** Warn about deprecated symbol.
194 * @param pos Position to be used for error reporting.
195 * @param sym The deprecated symbol.
196 */
197 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
198 if (!lint.isSuppressed(LintCategory.DEPRECATION))
199 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
200 }
202 /** Warn about unchecked operation.
203 * @param pos Position to be used for error reporting.
204 * @param msg A string describing the problem.
205 */
206 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
207 if (!lint.isSuppressed(LintCategory.UNCHECKED))
208 uncheckedHandler.report(pos, msg, args);
209 }
211 /** Warn about unsafe vararg method decl.
212 * @param pos Position to be used for error reporting.
213 * @param sym The deprecated symbol.
214 */
215 void warnUnsafeVararg(DiagnosticPosition pos, String key, Object... args) {
216 if (lint.isEnabled(LintCategory.VARARGS) && allowSimplifiedVarargs)
217 log.warning(LintCategory.VARARGS, pos, key, args);
218 }
220 /** Warn about using proprietary API.
221 * @param pos Position to be used for error reporting.
222 * @param msg A string describing the problem.
223 */
224 public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
225 if (!lint.isSuppressed(LintCategory.SUNAPI))
226 sunApiHandler.report(pos, msg, args);
227 }
229 public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
230 if (lint.isEnabled(LintCategory.STATIC))
231 log.warning(LintCategory.STATIC, pos, msg, args);
232 }
234 /**
235 * Report any deferred diagnostics.
236 */
237 public void reportDeferredDiagnostics() {
238 deprecationHandler.reportDeferredDiagnostic();
239 uncheckedHandler.reportDeferredDiagnostic();
240 sunApiHandler.reportDeferredDiagnostic();
241 }
244 /** Report a failure to complete a class.
245 * @param pos Position to be used for error reporting.
246 * @param ex The failure to report.
247 */
248 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
249 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
250 if (ex instanceof ClassReader.BadClassFile
251 && !suppressAbortOnBadClassFile) throw new Abort();
252 else return syms.errType;
253 }
255 /** Report a type error.
256 * @param pos Position to be used for error reporting.
257 * @param problem A string describing the error.
258 * @param found The type that was found.
259 * @param req The type that was required.
260 */
261 Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
262 log.error(pos, "prob.found.req",
263 problem, found, req);
264 return types.createErrorType(found);
265 }
267 Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
268 log.error(pos, "prob.found.req.1", problem, found, req, explanation);
269 return types.createErrorType(found);
270 }
272 /** Report an error that wrong type tag was found.
273 * @param pos Position to be used for error reporting.
274 * @param required An internationalized string describing the type tag
275 * required.
276 * @param found The type that was found.
277 */
278 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
279 // this error used to be raised by the parser,
280 // but has been delayed to this point:
281 if (found instanceof Type && ((Type)found).tag == VOID) {
282 log.error(pos, "illegal.start.of.type");
283 return syms.errType;
284 }
285 log.error(pos, "type.found.req", found, required);
286 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
287 }
289 /** Report an error that symbol cannot be referenced before super
290 * has been called.
291 * @param pos Position to be used for error reporting.
292 * @param sym The referenced symbol.
293 */
294 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
295 log.error(pos, "cant.ref.before.ctor.called", sym);
296 }
298 /** Report duplicate declaration error.
299 */
300 void duplicateError(DiagnosticPosition pos, Symbol sym) {
301 if (!sym.type.isErroneous()) {
302 log.error(pos, "already.defined", sym, sym.location());
303 }
304 }
306 /** Report array/varargs duplicate declaration
307 */
308 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
309 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
310 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
311 }
312 }
314 /* ************************************************************************
315 * duplicate declaration checking
316 *************************************************************************/
318 /** Check that variable does not hide variable with same name in
319 * immediately enclosing local scope.
320 * @param pos Position for error reporting.
321 * @param v The symbol.
322 * @param s The scope.
323 */
324 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
325 if (s.next != null) {
326 for (Scope.Entry e = s.next.lookup(v.name);
327 e.scope != null && e.sym.owner == v.owner;
328 e = e.next()) {
329 if (e.sym.kind == VAR &&
330 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
331 v.name != names.error) {
332 duplicateError(pos, e.sym);
333 return;
334 }
335 }
336 }
337 }
339 /** Check that a class or interface does not hide a class or
340 * interface with same name in immediately enclosing local scope.
341 * @param pos Position for error reporting.
342 * @param c The symbol.
343 * @param s The scope.
344 */
345 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
346 if (s.next != null) {
347 for (Scope.Entry e = s.next.lookup(c.name);
348 e.scope != null && e.sym.owner == c.owner;
349 e = e.next()) {
350 if (e.sym.kind == TYP && e.sym.type.tag != TYPEVAR &&
351 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
352 c.name != names.error) {
353 duplicateError(pos, e.sym);
354 return;
355 }
356 }
357 }
358 }
360 /** Check that class does not have the same name as one of
361 * its enclosing classes, or as a class defined in its enclosing scope.
362 * return true if class is unique in its enclosing scope.
363 * @param pos Position for error reporting.
364 * @param name The class name.
365 * @param s The enclosing scope.
366 */
367 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
368 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
369 if (e.sym.kind == TYP && e.sym.name != names.error) {
370 duplicateError(pos, e.sym);
371 return false;
372 }
373 }
374 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
375 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
376 duplicateError(pos, sym);
377 return true;
378 }
379 }
380 return true;
381 }
383 /* *************************************************************************
384 * Class name generation
385 **************************************************************************/
387 /** Return name of local class.
388 * This is of the form <enclClass> $ n <classname>
389 * where
390 * enclClass is the flat name of the enclosing class,
391 * classname is the simple name of the local class
392 */
393 Name localClassName(ClassSymbol c) {
394 for (int i=1; ; i++) {
395 Name flatname = names.
396 fromString("" + c.owner.enclClass().flatname +
397 syntheticNameChar + i +
398 c.name);
399 if (compiled.get(flatname) == null) return flatname;
400 }
401 }
403 /* *************************************************************************
404 * Type Checking
405 **************************************************************************/
407 /** Check that a given type is assignable to a given proto-type.
408 * If it is, return the type, otherwise return errType.
409 * @param pos Position to be used for error reporting.
410 * @param found The type that was found.
411 * @param req The type that was required.
412 */
413 Type checkType(DiagnosticPosition pos, Type found, Type req) {
414 return checkType(pos, found, req, "incompatible.types");
415 }
417 Type checkType(DiagnosticPosition pos, Type found, Type req, String errKey) {
418 if (req.tag == ERROR)
419 return req;
420 if (found.tag == FORALL)
421 return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
422 if (req.tag == NONE)
423 return found;
424 if (types.isAssignable(found, req, convertWarner(pos, found, req)))
425 return found;
426 if (found.tag <= DOUBLE && req.tag <= DOUBLE)
427 return typeError(pos, diags.fragment("possible.loss.of.precision"), found, req);
428 if (found.isSuperBound()) {
429 log.error(pos, "assignment.from.super-bound", found);
430 return types.createErrorType(found);
431 }
432 if (req.isExtendsBound()) {
433 log.error(pos, "assignment.to.extends-bound", req);
434 return types.createErrorType(found);
435 }
436 return typeError(pos, diags.fragment(errKey), found, req);
437 }
439 /** Instantiate polymorphic type to some prototype, unless
440 * prototype is `anyPoly' in which case polymorphic type
441 * is returned unchanged.
442 */
443 Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) throws Infer.NoInstanceException {
444 if (pt == Infer.anyPoly && complexInference) {
445 return t;
446 } else if (pt == Infer.anyPoly || pt.tag == NONE) {
447 Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
448 return instantiatePoly(pos, t, newpt, warn);
449 } else if (pt.tag == ERROR) {
450 return pt;
451 } else {
452 try {
453 return infer.instantiateExpr(t, pt, warn);
454 } catch (Infer.NoInstanceException ex) {
455 if (ex.isAmbiguous) {
456 JCDiagnostic d = ex.getDiagnostic();
457 log.error(pos,
458 "undetermined.type" + (d!=null ? ".1" : ""),
459 t, d);
460 return types.createErrorType(pt);
461 } else {
462 JCDiagnostic d = ex.getDiagnostic();
463 return typeError(pos,
464 diags.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
465 t, pt);
466 }
467 } catch (Infer.InvalidInstanceException ex) {
468 JCDiagnostic d = ex.getDiagnostic();
469 log.error(pos, "invalid.inferred.types", t.tvars, d);
470 return types.createErrorType(pt);
471 }
472 }
473 }
475 /** Check that a given type can be cast to a given target type.
476 * Return the result of the cast.
477 * @param pos Position to be used for error reporting.
478 * @param found The type that is being cast.
479 * @param req The target type of the cast.
480 */
481 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
482 if (found.tag == FORALL) {
483 instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
484 return req;
485 } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
486 return req;
487 } else {
488 return typeError(pos,
489 diags.fragment("inconvertible.types"),
490 found, req);
491 }
492 }
493 //where
494 /** Is type a type variable, or a (possibly multi-dimensional) array of
495 * type variables?
496 */
497 boolean isTypeVar(Type t) {
498 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
499 }
501 /** Check that a type is within some bounds.
502 *
503 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
504 * type argument.
505 * @param pos Position to be used for error reporting.
506 * @param a The type that should be bounded by bs.
507 * @param bs The bound.
508 */
509 private void checkExtends(DiagnosticPosition pos, Type a, TypeVar bs) {
510 if (a.isUnbound()) {
511 return;
512 } else if (a.tag != WILDCARD) {
513 a = types.upperBound(a);
514 for (List<Type> l = types.getBounds(bs); l.nonEmpty(); l = l.tail) {
515 if (!types.isSubtype(a, l.head)) {
516 log.error(pos, "not.within.bounds", a);
517 return;
518 }
519 }
520 } else if (a.isExtendsBound()) {
521 if (!types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings))
522 log.error(pos, "not.within.bounds", a);
523 } else if (a.isSuperBound()) {
524 if (types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound()))
525 log.error(pos, "not.within.bounds", a);
526 }
527 }
529 /** Check that a type is within some bounds.
530 *
531 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
532 * type argument.
533 * @param pos Position to be used for error reporting.
534 * @param a The type that should be bounded by bs.
535 * @param bs The bound.
536 */
537 private void checkCapture(JCTypeApply tree) {
538 List<JCExpression> args = tree.getTypeArguments();
539 for (Type arg : types.capture(tree.type).getTypeArguments()) {
540 if (arg.tag == TYPEVAR && arg.getUpperBound().isErroneous()) {
541 log.error(args.head.pos, "not.within.bounds", args.head.type);
542 break;
543 }
544 args = args.tail;
545 }
546 }
548 /** Check that type is different from 'void'.
549 * @param pos Position to be used for error reporting.
550 * @param t The type to be checked.
551 */
552 Type checkNonVoid(DiagnosticPosition pos, Type t) {
553 if (t.tag == VOID) {
554 log.error(pos, "void.not.allowed.here");
555 return types.createErrorType(t);
556 } else {
557 return t;
558 }
559 }
561 /** Check that type is a class or interface type.
562 * @param pos Position to be used for error reporting.
563 * @param t The type to be checked.
564 */
565 Type checkClassType(DiagnosticPosition pos, Type t) {
566 if (t.tag != CLASS && t.tag != ERROR)
567 return typeTagError(pos,
568 diags.fragment("type.req.class"),
569 (t.tag == TYPEVAR)
570 ? diags.fragment("type.parameter", t)
571 : t);
572 else
573 return t;
574 }
576 /** Check that type is a class or interface type.
577 * @param pos Position to be used for error reporting.
578 * @param t The type to be checked.
579 * @param noBounds True if type bounds are illegal here.
580 */
581 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
582 t = checkClassType(pos, t);
583 if (noBounds && t.isParameterized()) {
584 List<Type> args = t.getTypeArguments();
585 while (args.nonEmpty()) {
586 if (args.head.tag == WILDCARD)
587 return typeTagError(pos,
588 diags.fragment("type.req.exact"),
589 args.head);
590 args = args.tail;
591 }
592 }
593 return t;
594 }
596 /** Check that type is a reifiable class, interface or array type.
597 * @param pos Position to be used for error reporting.
598 * @param t The type to be checked.
599 */
600 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
601 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
602 return typeTagError(pos,
603 diags.fragment("type.req.class.array"),
604 t);
605 } else if (!types.isReifiable(t)) {
606 log.error(pos, "illegal.generic.type.for.instof");
607 return types.createErrorType(t);
608 } else {
609 return t;
610 }
611 }
613 /** Check that type is a reference type, i.e. a class, interface or array type
614 * or a type variable.
615 * @param pos Position to be used for error reporting.
616 * @param t The type to be checked.
617 */
618 Type checkRefType(DiagnosticPosition pos, Type t) {
619 switch (t.tag) {
620 case CLASS:
621 case ARRAY:
622 case TYPEVAR:
623 case WILDCARD:
624 case ERROR:
625 return t;
626 default:
627 return typeTagError(pos,
628 diags.fragment("type.req.ref"),
629 t);
630 }
631 }
633 /** Check that each type is a reference type, i.e. a class, interface or array type
634 * or a type variable.
635 * @param trees Original trees, used for error reporting.
636 * @param types The types to be checked.
637 */
638 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
639 List<JCExpression> tl = trees;
640 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
641 l.head = checkRefType(tl.head.pos(), l.head);
642 tl = tl.tail;
643 }
644 return types;
645 }
647 /** Check that type is a null or reference type.
648 * @param pos Position to be used for error reporting.
649 * @param t The type to be checked.
650 */
651 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
652 switch (t.tag) {
653 case CLASS:
654 case ARRAY:
655 case TYPEVAR:
656 case WILDCARD:
657 case BOT:
658 case ERROR:
659 return t;
660 default:
661 return typeTagError(pos,
662 diags.fragment("type.req.ref"),
663 t);
664 }
665 }
667 /** Check that flag set does not contain elements of two conflicting sets. s
668 * Return true if it doesn't.
669 * @param pos Position to be used for error reporting.
670 * @param flags The set of flags to be checked.
671 * @param set1 Conflicting flags set #1.
672 * @param set2 Conflicting flags set #2.
673 */
674 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
675 if ((flags & set1) != 0 && (flags & set2) != 0) {
676 log.error(pos,
677 "illegal.combination.of.modifiers",
678 asFlagSet(TreeInfo.firstFlag(flags & set1)),
679 asFlagSet(TreeInfo.firstFlag(flags & set2)));
680 return false;
681 } else
682 return true;
683 }
685 /** Check that the type inferred using the diamond operator does not contain
686 * non-denotable types such as captured types or intersection types.
687 * @param t the type inferred using the diamond operator
688 */
689 List<Type> checkDiamond(ClassType t) {
690 DiamondTypeChecker dtc = new DiamondTypeChecker();
691 ListBuffer<Type> buf = ListBuffer.lb();
692 for (Type arg : t.getTypeArguments()) {
693 if (!dtc.visit(arg, null)) {
694 buf.append(arg);
695 }
696 }
697 return buf.toList();
698 }
700 static class DiamondTypeChecker extends Types.SimpleVisitor<Boolean, Void> {
701 public Boolean visitType(Type t, Void s) {
702 return true;
703 }
704 @Override
705 public Boolean visitClassType(ClassType t, Void s) {
706 if (t.isCompound()) {
707 return false;
708 }
709 for (Type targ : t.getTypeArguments()) {
710 if (!visit(targ, s)) {
711 return false;
712 }
713 }
714 return true;
715 }
716 @Override
717 public Boolean visitCapturedType(CapturedType t, Void s) {
718 return false;
719 }
720 }
722 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
723 MethodSymbol m = tree.sym;
724 if (!allowSimplifiedVarargs) return;
725 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
726 Type varargElemType = null;
727 if (m.isVarArgs()) {
728 varargElemType = types.elemtype(tree.params.last().type);
729 }
730 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
731 if (varargElemType != null) {
732 log.error(tree,
733 "varargs.invalid.trustme.anno",
734 syms.trustMeType.tsym,
735 diags.fragment("varargs.trustme.on.virtual.varargs", m));
736 } else {
737 log.error(tree,
738 "varargs.invalid.trustme.anno",
739 syms.trustMeType.tsym,
740 diags.fragment("varargs.trustme.on.non.varargs.meth", m));
741 }
742 } else if (hasTrustMeAnno && varargElemType != null &&
743 types.isReifiable(varargElemType)) {
744 warnUnsafeVararg(tree,
745 "varargs.redundant.trustme.anno",
746 syms.trustMeType.tsym,
747 diags.fragment("varargs.trustme.on.reifiable.varargs", varargElemType));
748 }
749 else if (!hasTrustMeAnno && varargElemType != null &&
750 !types.isReifiable(varargElemType)) {
751 warnUnchecked(tree.params.head.pos(), "unchecked.varargs.non.reifiable.type", varargElemType);
752 }
753 }
754 //where
755 private boolean isTrustMeAllowedOnMethod(Symbol s) {
756 return (s.flags() & VARARGS) != 0 &&
757 (s.isConstructor() ||
758 (s.flags() & (STATIC | FINAL)) != 0);
759 }
761 /**
762 * Check that vararg method call is sound
763 * @param pos Position to be used for error reporting.
764 * @param argtypes Actual arguments supplied to vararg method.
765 */
766 void checkVararg(DiagnosticPosition pos, List<Type> argtypes, Symbol msym) {
767 Type argtype = argtypes.last();
768 if (!types.isReifiable(argtype) &&
769 (!allowSimplifiedVarargs ||
770 msym.attribute(syms.trustMeType.tsym) == null ||
771 !isTrustMeAllowedOnMethod(msym))) {
772 warnUnchecked(pos,
773 "unchecked.generic.array.creation",
774 argtype);
775 }
776 }
778 /** Check that given modifiers are legal for given symbol and
779 * return modifiers together with any implicit modififiers for that symbol.
780 * Warning: we can't use flags() here since this method
781 * is called during class enter, when flags() would cause a premature
782 * completion.
783 * @param pos Position to be used for error reporting.
784 * @param flags The set of modifiers given in a definition.
785 * @param sym The defined symbol.
786 */
787 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
788 long mask;
789 long implicit = 0;
790 switch (sym.kind) {
791 case VAR:
792 if (sym.owner.kind != TYP)
793 mask = LocalVarFlags;
794 else if ((sym.owner.flags_field & INTERFACE) != 0)
795 mask = implicit = InterfaceVarFlags;
796 else
797 mask = VarFlags;
798 break;
799 case MTH:
800 if (sym.name == names.init) {
801 if ((sym.owner.flags_field & ENUM) != 0) {
802 // enum constructors cannot be declared public or
803 // protected and must be implicitly or explicitly
804 // private
805 implicit = PRIVATE;
806 mask = PRIVATE;
807 } else
808 mask = ConstructorFlags;
809 } else if ((sym.owner.flags_field & INTERFACE) != 0)
810 mask = implicit = InterfaceMethodFlags;
811 else {
812 mask = MethodFlags;
813 }
814 // Imply STRICTFP if owner has STRICTFP set.
815 if (((flags|implicit) & Flags.ABSTRACT) == 0)
816 implicit |= sym.owner.flags_field & STRICTFP;
817 break;
818 case TYP:
819 if (sym.isLocal()) {
820 mask = LocalClassFlags;
821 if (sym.name.isEmpty()) { // Anonymous class
822 // Anonymous classes in static methods are themselves static;
823 // that's why we admit STATIC here.
824 mask |= STATIC;
825 // JLS: Anonymous classes are final.
826 implicit |= FINAL;
827 }
828 if ((sym.owner.flags_field & STATIC) == 0 &&
829 (flags & ENUM) != 0)
830 log.error(pos, "enums.must.be.static");
831 } else if (sym.owner.kind == TYP) {
832 mask = MemberClassFlags;
833 if (sym.owner.owner.kind == PCK ||
834 (sym.owner.flags_field & STATIC) != 0)
835 mask |= STATIC;
836 else if ((flags & ENUM) != 0)
837 log.error(pos, "enums.must.be.static");
838 // Nested interfaces and enums are always STATIC (Spec ???)
839 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
840 } else {
841 mask = ClassFlags;
842 }
843 // Interfaces are always ABSTRACT
844 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
846 if ((flags & ENUM) != 0) {
847 // enums can't be declared abstract or final
848 mask &= ~(ABSTRACT | FINAL);
849 implicit |= implicitEnumFinalFlag(tree);
850 }
851 // Imply STRICTFP if owner has STRICTFP set.
852 implicit |= sym.owner.flags_field & STRICTFP;
853 break;
854 default:
855 throw new AssertionError();
856 }
857 long illegal = flags & StandardFlags & ~mask;
858 if (illegal != 0) {
859 if ((illegal & INTERFACE) != 0) {
860 log.error(pos, "intf.not.allowed.here");
861 mask |= INTERFACE;
862 }
863 else {
864 log.error(pos,
865 "mod.not.allowed.here", asFlagSet(illegal));
866 }
867 }
868 else if ((sym.kind == TYP ||
869 // ISSUE: Disallowing abstract&private is no longer appropriate
870 // in the presence of inner classes. Should it be deleted here?
871 checkDisjoint(pos, flags,
872 ABSTRACT,
873 PRIVATE | STATIC))
874 &&
875 checkDisjoint(pos, flags,
876 ABSTRACT | INTERFACE,
877 FINAL | NATIVE | SYNCHRONIZED)
878 &&
879 checkDisjoint(pos, flags,
880 PUBLIC,
881 PRIVATE | PROTECTED)
882 &&
883 checkDisjoint(pos, flags,
884 PRIVATE,
885 PUBLIC | PROTECTED)
886 &&
887 checkDisjoint(pos, flags,
888 FINAL,
889 VOLATILE)
890 &&
891 (sym.kind == TYP ||
892 checkDisjoint(pos, flags,
893 ABSTRACT | NATIVE,
894 STRICTFP))) {
895 // skip
896 }
897 return flags & (mask | ~StandardFlags) | implicit;
898 }
901 /** Determine if this enum should be implicitly final.
902 *
903 * If the enum has no specialized enum contants, it is final.
904 *
905 * If the enum does have specialized enum contants, it is
906 * <i>not</i> final.
907 */
908 private long implicitEnumFinalFlag(JCTree tree) {
909 if (tree.getTag() != JCTree.CLASSDEF) return 0;
910 class SpecialTreeVisitor extends JCTree.Visitor {
911 boolean specialized;
912 SpecialTreeVisitor() {
913 this.specialized = false;
914 };
916 @Override
917 public void visitTree(JCTree tree) { /* no-op */ }
919 @Override
920 public void visitVarDef(JCVariableDecl tree) {
921 if ((tree.mods.flags & ENUM) != 0) {
922 if (tree.init instanceof JCNewClass &&
923 ((JCNewClass) tree.init).def != null) {
924 specialized = true;
925 }
926 }
927 }
928 }
930 SpecialTreeVisitor sts = new SpecialTreeVisitor();
931 JCClassDecl cdef = (JCClassDecl) tree;
932 for (JCTree defs: cdef.defs) {
933 defs.accept(sts);
934 if (sts.specialized) return 0;
935 }
936 return FINAL;
937 }
939 /* *************************************************************************
940 * Type Validation
941 **************************************************************************/
943 /** Validate a type expression. That is,
944 * check that all type arguments of a parametric type are within
945 * their bounds. This must be done in a second phase after type attributon
946 * since a class might have a subclass as type parameter bound. E.g:
947 *
948 * class B<A extends C> { ... }
949 * class C extends B<C> { ... }
950 *
951 * and we can't make sure that the bound is already attributed because
952 * of possible cycles.
953 *
954 * Visitor method: Validate a type expression, if it is not null, catching
955 * and reporting any completion failures.
956 */
957 void validate(JCTree tree, Env<AttrContext> env) {
958 validate(tree, env, true);
959 }
960 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
961 new Validator(env).validateTree(tree, checkRaw, true);
962 }
964 /** Visitor method: Validate a list of type expressions.
965 */
966 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
967 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
968 validate(l.head, env);
969 }
971 /** A visitor class for type validation.
972 */
973 class Validator extends JCTree.Visitor {
975 boolean isOuter;
976 Env<AttrContext> env;
978 Validator(Env<AttrContext> env) {
979 this.env = env;
980 }
982 @Override
983 public void visitTypeArray(JCArrayTypeTree tree) {
984 tree.elemtype.accept(this);
985 }
987 @Override
988 public void visitTypeApply(JCTypeApply tree) {
989 if (tree.type.tag == CLASS) {
990 List<Type> formals = tree.type.tsym.type.allparams();
991 List<Type> actuals = tree.type.allparams();
992 List<JCExpression> args = tree.arguments;
993 List<Type> forms = tree.type.tsym.type.getTypeArguments();
994 ListBuffer<Type> tvars_buf = new ListBuffer<Type>();
996 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
998 // For matching pairs of actual argument types `a' and
999 // formal type parameters with declared bound `b' ...
1000 while (args.nonEmpty() && forms.nonEmpty()) {
1001 validateTree(args.head,
1002 !(isOuter && is_java_lang_Class),
1003 false);
1005 // exact type arguments needs to know their
1006 // bounds (for upper and lower bound
1007 // calculations). So we create new TypeVars with
1008 // bounds substed with actuals.
1009 tvars_buf.append(types.substBound(((TypeVar)forms.head),
1010 formals,
1011 actuals));
1013 args = args.tail;
1014 forms = forms.tail;
1015 }
1017 args = tree.arguments;
1018 List<Type> tvars_cap = types.substBounds(formals,
1019 formals,
1020 types.capture(tree.type).allparams());
1021 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
1022 // Let the actual arguments know their bound
1023 args.head.type.withTypeVar((TypeVar)tvars_cap.head);
1024 args = args.tail;
1025 tvars_cap = tvars_cap.tail;
1026 }
1028 args = tree.arguments;
1029 List<Type> tvars = tvars_buf.toList();
1031 while (args.nonEmpty() && tvars.nonEmpty()) {
1032 Type actual = types.subst(args.head.type,
1033 tree.type.tsym.type.getTypeArguments(),
1034 tvars_buf.toList());
1035 checkExtends(args.head.pos(),
1036 actual,
1037 (TypeVar)tvars.head);
1038 args = args.tail;
1039 tvars = tvars.tail;
1040 }
1042 checkCapture(tree);
1044 // Check that this type is either fully parameterized, or
1045 // not parameterized at all.
1046 if (tree.type.getEnclosingType().isRaw())
1047 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1048 if (tree.clazz.getTag() == JCTree.SELECT)
1049 visitSelectInternal((JCFieldAccess)tree.clazz);
1050 }
1051 }
1053 @Override
1054 public void visitTypeParameter(JCTypeParameter tree) {
1055 validateTrees(tree.bounds, true, isOuter);
1056 checkClassBounds(tree.pos(), tree.type);
1057 }
1059 @Override
1060 public void visitWildcard(JCWildcard tree) {
1061 if (tree.inner != null)
1062 validateTree(tree.inner, true, isOuter);
1063 }
1065 @Override
1066 public void visitSelect(JCFieldAccess tree) {
1067 if (tree.type.tag == CLASS) {
1068 visitSelectInternal(tree);
1070 // Check that this type is either fully parameterized, or
1071 // not parameterized at all.
1072 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1073 log.error(tree.pos(), "improperly.formed.type.param.missing");
1074 }
1075 }
1076 public void visitSelectInternal(JCFieldAccess tree) {
1077 if (tree.type.tsym.isStatic() &&
1078 tree.selected.type.isParameterized()) {
1079 // The enclosing type is not a class, so we are
1080 // looking at a static member type. However, the
1081 // qualifying expression is parameterized.
1082 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1083 } else {
1084 // otherwise validate the rest of the expression
1085 tree.selected.accept(this);
1086 }
1087 }
1089 @Override
1090 public void visitAnnotatedType(JCAnnotatedType tree) {
1091 tree.underlyingType.accept(this);
1092 }
1094 /** Default visitor method: do nothing.
1095 */
1096 @Override
1097 public void visitTree(JCTree tree) {
1098 }
1100 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1101 try {
1102 if (tree != null) {
1103 this.isOuter = isOuter;
1104 tree.accept(this);
1105 if (checkRaw)
1106 checkRaw(tree, env);
1107 }
1108 } catch (CompletionFailure ex) {
1109 completionError(tree.pos(), ex);
1110 }
1111 }
1113 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1114 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1115 validateTree(l.head, checkRaw, isOuter);
1116 }
1118 void checkRaw(JCTree tree, Env<AttrContext> env) {
1119 if (lint.isEnabled(LintCategory.RAW) &&
1120 tree.type.tag == CLASS &&
1121 !TreeInfo.isDiamond(tree) &&
1122 !env.enclClass.name.isEmpty() && //anonymous or intersection
1123 tree.type.isRaw()) {
1124 log.warning(LintCategory.RAW,
1125 tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
1126 }
1127 }
1128 }
1130 /* *************************************************************************
1131 * Exception checking
1132 **************************************************************************/
1134 /* The following methods treat classes as sets that contain
1135 * the class itself and all their subclasses
1136 */
1138 /** Is given type a subtype of some of the types in given list?
1139 */
1140 boolean subset(Type t, List<Type> ts) {
1141 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1142 if (types.isSubtype(t, l.head)) return true;
1143 return false;
1144 }
1146 /** Is given type a subtype or supertype of
1147 * some of the types in given list?
1148 */
1149 boolean intersects(Type t, List<Type> ts) {
1150 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1151 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1152 return false;
1153 }
1155 /** Add type set to given type list, unless it is a subclass of some class
1156 * in the list.
1157 */
1158 List<Type> incl(Type t, List<Type> ts) {
1159 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1160 }
1162 /** Remove type set from type set list.
1163 */
1164 List<Type> excl(Type t, List<Type> ts) {
1165 if (ts.isEmpty()) {
1166 return ts;
1167 } else {
1168 List<Type> ts1 = excl(t, ts.tail);
1169 if (types.isSubtype(ts.head, t)) return ts1;
1170 else if (ts1 == ts.tail) return ts;
1171 else return ts1.prepend(ts.head);
1172 }
1173 }
1175 /** Form the union of two type set lists.
1176 */
1177 List<Type> union(List<Type> ts1, List<Type> ts2) {
1178 List<Type> ts = ts1;
1179 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1180 ts = incl(l.head, ts);
1181 return ts;
1182 }
1184 /** Form the difference of two type lists.
1185 */
1186 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1187 List<Type> ts = ts1;
1188 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1189 ts = excl(l.head, ts);
1190 return ts;
1191 }
1193 /** Form the intersection of two type lists.
1194 */
1195 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1196 List<Type> ts = List.nil();
1197 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1198 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1199 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1200 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1201 return ts;
1202 }
1204 /** Is exc an exception symbol that need not be declared?
1205 */
1206 boolean isUnchecked(ClassSymbol exc) {
1207 return
1208 exc.kind == ERR ||
1209 exc.isSubClass(syms.errorType.tsym, types) ||
1210 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1211 }
1213 /** Is exc an exception type that need not be declared?
1214 */
1215 boolean isUnchecked(Type exc) {
1216 return
1217 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
1218 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
1219 exc.tag == BOT;
1220 }
1222 /** Same, but handling completion failures.
1223 */
1224 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1225 try {
1226 return isUnchecked(exc);
1227 } catch (CompletionFailure ex) {
1228 completionError(pos, ex);
1229 return true;
1230 }
1231 }
1233 /** Is exc handled by given exception list?
1234 */
1235 boolean isHandled(Type exc, List<Type> handled) {
1236 return isUnchecked(exc) || subset(exc, handled);
1237 }
1239 /** Return all exceptions in thrown list that are not in handled list.
1240 * @param thrown The list of thrown exceptions.
1241 * @param handled The list of handled exceptions.
1242 */
1243 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1244 List<Type> unhandled = List.nil();
1245 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1246 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1247 return unhandled;
1248 }
1250 /* *************************************************************************
1251 * Overriding/Implementation checking
1252 **************************************************************************/
1254 /** The level of access protection given by a flag set,
1255 * where PRIVATE is highest and PUBLIC is lowest.
1256 */
1257 static int protection(long flags) {
1258 switch ((short)(flags & AccessFlags)) {
1259 case PRIVATE: return 3;
1260 case PROTECTED: return 1;
1261 default:
1262 case PUBLIC: return 0;
1263 case 0: return 2;
1264 }
1265 }
1267 /** A customized "cannot override" error message.
1268 * @param m The overriding method.
1269 * @param other The overridden method.
1270 * @return An internationalized string.
1271 */
1272 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1273 String key;
1274 if ((other.owner.flags() & INTERFACE) == 0)
1275 key = "cant.override";
1276 else if ((m.owner.flags() & INTERFACE) == 0)
1277 key = "cant.implement";
1278 else
1279 key = "clashes.with";
1280 return diags.fragment(key, m, m.location(), other, other.location());
1281 }
1283 /** A customized "override" warning message.
1284 * @param m The overriding method.
1285 * @param other The overridden method.
1286 * @return An internationalized string.
1287 */
1288 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1289 String key;
1290 if ((other.owner.flags() & INTERFACE) == 0)
1291 key = "unchecked.override";
1292 else if ((m.owner.flags() & INTERFACE) == 0)
1293 key = "unchecked.implement";
1294 else
1295 key = "unchecked.clash.with";
1296 return diags.fragment(key, m, m.location(), other, other.location());
1297 }
1299 /** A customized "override" warning message.
1300 * @param m The overriding method.
1301 * @param other The overridden method.
1302 * @return An internationalized string.
1303 */
1304 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1305 String key;
1306 if ((other.owner.flags() & INTERFACE) == 0)
1307 key = "varargs.override";
1308 else if ((m.owner.flags() & INTERFACE) == 0)
1309 key = "varargs.implement";
1310 else
1311 key = "varargs.clash.with";
1312 return diags.fragment(key, m, m.location(), other, other.location());
1313 }
1315 /** Check that this method conforms with overridden method 'other'.
1316 * where `origin' is the class where checking started.
1317 * Complications:
1318 * (1) Do not check overriding of synthetic methods
1319 * (reason: they might be final).
1320 * todo: check whether this is still necessary.
1321 * (2) Admit the case where an interface proxy throws fewer exceptions
1322 * than the method it implements. Augment the proxy methods with the
1323 * undeclared exceptions in this case.
1324 * (3) When generics are enabled, admit the case where an interface proxy
1325 * has a result type
1326 * extended by the result type of the method it implements.
1327 * Change the proxies result type to the smaller type in this case.
1328 *
1329 * @param tree The tree from which positions
1330 * are extracted for errors.
1331 * @param m The overriding method.
1332 * @param other The overridden method.
1333 * @param origin The class of which the overriding method
1334 * is a member.
1335 */
1336 void checkOverride(JCTree tree,
1337 MethodSymbol m,
1338 MethodSymbol other,
1339 ClassSymbol origin) {
1340 // Don't check overriding of synthetic methods or by bridge methods.
1341 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1342 return;
1343 }
1345 // Error if static method overrides instance method (JLS 8.4.6.2).
1346 if ((m.flags() & STATIC) != 0 &&
1347 (other.flags() & STATIC) == 0) {
1348 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1349 cannotOverride(m, other));
1350 return;
1351 }
1353 // Error if instance method overrides static or final
1354 // method (JLS 8.4.6.1).
1355 if ((other.flags() & FINAL) != 0 ||
1356 (m.flags() & STATIC) == 0 &&
1357 (other.flags() & STATIC) != 0) {
1358 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1359 cannotOverride(m, other),
1360 asFlagSet(other.flags() & (FINAL | STATIC)));
1361 return;
1362 }
1364 if ((m.owner.flags() & ANNOTATION) != 0) {
1365 // handled in validateAnnotationMethod
1366 return;
1367 }
1369 // Error if overriding method has weaker access (JLS 8.4.6.3).
1370 if ((origin.flags() & INTERFACE) == 0 &&
1371 protection(m.flags()) > protection(other.flags())) {
1372 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1373 cannotOverride(m, other),
1374 other.flags() == 0 ?
1375 Flag.PACKAGE :
1376 asFlagSet(other.flags() & AccessFlags));
1377 return;
1378 }
1380 Type mt = types.memberType(origin.type, m);
1381 Type ot = types.memberType(origin.type, other);
1382 // Error if overriding result type is different
1383 // (or, in the case of generics mode, not a subtype) of
1384 // overridden result type. We have to rename any type parameters
1385 // before comparing types.
1386 List<Type> mtvars = mt.getTypeArguments();
1387 List<Type> otvars = ot.getTypeArguments();
1388 Type mtres = mt.getReturnType();
1389 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1391 overrideWarner.clear();
1392 boolean resultTypesOK =
1393 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1394 if (!resultTypesOK) {
1395 if (!allowCovariantReturns &&
1396 m.owner != origin &&
1397 m.owner.isSubClass(other.owner, types)) {
1398 // allow limited interoperability with covariant returns
1399 } else {
1400 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1401 "override.incompatible.ret",
1402 cannotOverride(m, other),
1403 mtres, otres);
1404 return;
1405 }
1406 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1407 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1408 "override.unchecked.ret",
1409 uncheckedOverrides(m, other),
1410 mtres, otres);
1411 }
1413 // Error if overriding method throws an exception not reported
1414 // by overridden method.
1415 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1416 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1417 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1418 if (unhandledErased.nonEmpty()) {
1419 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1420 "override.meth.doesnt.throw",
1421 cannotOverride(m, other),
1422 unhandledUnerased.head);
1423 return;
1424 }
1425 else if (unhandledUnerased.nonEmpty()) {
1426 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1427 "override.unchecked.thrown",
1428 cannotOverride(m, other),
1429 unhandledUnerased.head);
1430 return;
1431 }
1433 // Optional warning if varargs don't agree
1434 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1435 && lint.isEnabled(LintCategory.OVERRIDES)) {
1436 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1437 ((m.flags() & Flags.VARARGS) != 0)
1438 ? "override.varargs.missing"
1439 : "override.varargs.extra",
1440 varargsOverrides(m, other));
1441 }
1443 // Warn if instance method overrides bridge method (compiler spec ??)
1444 if ((other.flags() & BRIDGE) != 0) {
1445 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1446 uncheckedOverrides(m, other));
1447 }
1449 // Warn if a deprecated method overridden by a non-deprecated one.
1450 if ((other.flags() & DEPRECATED) != 0
1451 && (m.flags() & DEPRECATED) == 0
1452 && m.outermostClass() != other.outermostClass()
1453 && !isDeprecatedOverrideIgnorable(other, origin)) {
1454 warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
1455 }
1456 }
1457 // where
1458 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1459 // If the method, m, is defined in an interface, then ignore the issue if the method
1460 // is only inherited via a supertype and also implemented in the supertype,
1461 // because in that case, we will rediscover the issue when examining the method
1462 // in the supertype.
1463 // If the method, m, is not defined in an interface, then the only time we need to
1464 // address the issue is when the method is the supertype implemementation: any other
1465 // case, we will have dealt with when examining the supertype classes
1466 ClassSymbol mc = m.enclClass();
1467 Type st = types.supertype(origin.type);
1468 if (st.tag != CLASS)
1469 return true;
1470 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1472 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1473 List<Type> intfs = types.interfaces(origin.type);
1474 return (intfs.contains(mc.type) ? false : (stimpl != null));
1475 }
1476 else
1477 return (stimpl != m);
1478 }
1481 // used to check if there were any unchecked conversions
1482 Warner overrideWarner = new Warner();
1484 /** Check that a class does not inherit two concrete methods
1485 * with the same signature.
1486 * @param pos Position to be used for error reporting.
1487 * @param site The class type to be checked.
1488 */
1489 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1490 Type sup = types.supertype(site);
1491 if (sup.tag != CLASS) return;
1493 for (Type t1 = sup;
1494 t1.tsym.type.isParameterized();
1495 t1 = types.supertype(t1)) {
1496 for (Scope.Entry e1 = t1.tsym.members().elems;
1497 e1 != null;
1498 e1 = e1.sibling) {
1499 Symbol s1 = e1.sym;
1500 if (s1.kind != MTH ||
1501 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1502 !s1.isInheritedIn(site.tsym, types) ||
1503 ((MethodSymbol)s1).implementation(site.tsym,
1504 types,
1505 true) != s1)
1506 continue;
1507 Type st1 = types.memberType(t1, s1);
1508 int s1ArgsLength = st1.getParameterTypes().length();
1509 if (st1 == s1.type) continue;
1511 for (Type t2 = sup;
1512 t2.tag == CLASS;
1513 t2 = types.supertype(t2)) {
1514 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1515 e2.scope != null;
1516 e2 = e2.next()) {
1517 Symbol s2 = e2.sym;
1518 if (s2 == s1 ||
1519 s2.kind != MTH ||
1520 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1521 s2.type.getParameterTypes().length() != s1ArgsLength ||
1522 !s2.isInheritedIn(site.tsym, types) ||
1523 ((MethodSymbol)s2).implementation(site.tsym,
1524 types,
1525 true) != s2)
1526 continue;
1527 Type st2 = types.memberType(t2, s2);
1528 if (types.overrideEquivalent(st1, st2))
1529 log.error(pos, "concrete.inheritance.conflict",
1530 s1, t1, s2, t2, sup);
1531 }
1532 }
1533 }
1534 }
1535 }
1537 /** Check that classes (or interfaces) do not each define an abstract
1538 * method with same name and arguments but incompatible return types.
1539 * @param pos Position to be used for error reporting.
1540 * @param t1 The first argument type.
1541 * @param t2 The second argument type.
1542 */
1543 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1544 Type t1,
1545 Type t2) {
1546 return checkCompatibleAbstracts(pos, t1, t2,
1547 types.makeCompoundType(t1, t2));
1548 }
1550 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1551 Type t1,
1552 Type t2,
1553 Type site) {
1554 return firstIncompatibility(pos, t1, t2, site) == null;
1555 }
1557 /** Return the first method which is defined with same args
1558 * but different return types in two given interfaces, or null if none
1559 * exists.
1560 * @param t1 The first type.
1561 * @param t2 The second type.
1562 * @param site The most derived type.
1563 * @returns symbol from t2 that conflicts with one in t1.
1564 */
1565 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1566 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1567 closure(t1, interfaces1);
1568 Map<TypeSymbol,Type> interfaces2;
1569 if (t1 == t2)
1570 interfaces2 = interfaces1;
1571 else
1572 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1574 for (Type t3 : interfaces1.values()) {
1575 for (Type t4 : interfaces2.values()) {
1576 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
1577 if (s != null) return s;
1578 }
1579 }
1580 return null;
1581 }
1583 /** Compute all the supertypes of t, indexed by type symbol. */
1584 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1585 if (t.tag != CLASS) return;
1586 if (typeMap.put(t.tsym, t) == null) {
1587 closure(types.supertype(t), typeMap);
1588 for (Type i : types.interfaces(t))
1589 closure(i, typeMap);
1590 }
1591 }
1593 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1594 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1595 if (t.tag != CLASS) return;
1596 if (typesSkip.get(t.tsym) != null) return;
1597 if (typeMap.put(t.tsym, t) == null) {
1598 closure(types.supertype(t), typesSkip, typeMap);
1599 for (Type i : types.interfaces(t))
1600 closure(i, typesSkip, typeMap);
1601 }
1602 }
1604 /** Return the first method in t2 that conflicts with a method from t1. */
1605 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1606 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1607 Symbol s1 = e1.sym;
1608 Type st1 = null;
1609 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1610 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1611 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1612 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1613 Symbol s2 = e2.sym;
1614 if (s1 == s2) continue;
1615 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1616 if (st1 == null) st1 = types.memberType(t1, s1);
1617 Type st2 = types.memberType(t2, s2);
1618 if (types.overrideEquivalent(st1, st2)) {
1619 List<Type> tvars1 = st1.getTypeArguments();
1620 List<Type> tvars2 = st2.getTypeArguments();
1621 Type rt1 = st1.getReturnType();
1622 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1623 boolean compat =
1624 types.isSameType(rt1, rt2) ||
1625 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1626 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1627 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1628 checkCommonOverriderIn(s1,s2,site);
1629 if (!compat) {
1630 log.error(pos, "types.incompatible.diff.ret",
1631 t1, t2, s2.name +
1632 "(" + types.memberType(t2, s2).getParameterTypes() + ")");
1633 return s2;
1634 }
1635 } else if (!checkNameClash((ClassSymbol)site.tsym, s1, s2)) {
1636 log.error(pos,
1637 "name.clash.same.erasure.no.override",
1638 s1, s1.location(),
1639 s2, s2.location());
1640 return s2;
1641 }
1642 }
1643 }
1644 return null;
1645 }
1646 //WHERE
1647 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1648 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1649 Type st1 = types.memberType(site, s1);
1650 Type st2 = types.memberType(site, s2);
1651 closure(site, supertypes);
1652 for (Type t : supertypes.values()) {
1653 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1654 Symbol s3 = e.sym;
1655 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1656 Type st3 = types.memberType(site,s3);
1657 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1658 if (s3.owner == site.tsym) {
1659 return true;
1660 }
1661 List<Type> tvars1 = st1.getTypeArguments();
1662 List<Type> tvars2 = st2.getTypeArguments();
1663 List<Type> tvars3 = st3.getTypeArguments();
1664 Type rt1 = st1.getReturnType();
1665 Type rt2 = st2.getReturnType();
1666 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1667 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1668 boolean compat =
1669 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1670 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1671 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1672 if (compat)
1673 return true;
1674 }
1675 }
1676 }
1677 return false;
1678 }
1680 /** Check that a given method conforms with any method it overrides.
1681 * @param tree The tree from which positions are extracted
1682 * for errors.
1683 * @param m The overriding method.
1684 */
1685 void checkOverride(JCTree tree, MethodSymbol m) {
1686 ClassSymbol origin = (ClassSymbol)m.owner;
1687 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1688 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1689 log.error(tree.pos(), "enum.no.finalize");
1690 return;
1691 }
1692 for (Type t = origin.type; t.tag == CLASS;
1693 t = types.supertype(t)) {
1694 if (t != origin.type) {
1695 checkOverride(tree, t, origin, m);
1696 }
1697 for (Type t2 : types.interfaces(t)) {
1698 checkOverride(tree, t2, origin, m);
1699 }
1700 }
1701 }
1703 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
1704 TypeSymbol c = site.tsym;
1705 Scope.Entry e = c.members().lookup(m.name);
1706 while (e.scope != null) {
1707 if (m.overrides(e.sym, origin, types, false)) {
1708 if ((e.sym.flags() & ABSTRACT) == 0) {
1709 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1710 }
1711 }
1712 e = e.next();
1713 }
1714 }
1716 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
1717 if (s1.kind == MTH &&
1718 s1.isInheritedIn(origin, types) &&
1719 (s1.flags() & SYNTHETIC) == 0 &&
1720 !s2.isConstructor()) {
1721 Type er1 = s2.erasure(types);
1722 Type er2 = s1.erasure(types);
1723 if (types.isSameTypes(er1.getParameterTypes(),
1724 er2.getParameterTypes())) {
1725 return false;
1726 }
1727 }
1728 return true;
1729 }
1732 /** Check that all abstract members of given class have definitions.
1733 * @param pos Position to be used for error reporting.
1734 * @param c The class.
1735 */
1736 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1737 try {
1738 MethodSymbol undef = firstUndef(c, c);
1739 if (undef != null) {
1740 if ((c.flags() & ENUM) != 0 &&
1741 types.supertype(c.type).tsym == syms.enumSym &&
1742 (c.flags() & FINAL) == 0) {
1743 // add the ABSTRACT flag to an enum
1744 c.flags_field |= ABSTRACT;
1745 } else {
1746 MethodSymbol undef1 =
1747 new MethodSymbol(undef.flags(), undef.name,
1748 types.memberType(c.type, undef), undef.owner);
1749 log.error(pos, "does.not.override.abstract",
1750 c, undef1, undef1.location());
1751 }
1752 }
1753 } catch (CompletionFailure ex) {
1754 completionError(pos, ex);
1755 }
1756 }
1757 //where
1758 /** Return first abstract member of class `c' that is not defined
1759 * in `impl', null if there is none.
1760 */
1761 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1762 MethodSymbol undef = null;
1763 // Do not bother to search in classes that are not abstract,
1764 // since they cannot have abstract members.
1765 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1766 Scope s = c.members();
1767 for (Scope.Entry e = s.elems;
1768 undef == null && e != null;
1769 e = e.sibling) {
1770 if (e.sym.kind == MTH &&
1771 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1772 MethodSymbol absmeth = (MethodSymbol)e.sym;
1773 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1774 if (implmeth == null || implmeth == absmeth)
1775 undef = absmeth;
1776 }
1777 }
1778 if (undef == null) {
1779 Type st = types.supertype(c.type);
1780 if (st.tag == CLASS)
1781 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1782 }
1783 for (List<Type> l = types.interfaces(c.type);
1784 undef == null && l.nonEmpty();
1785 l = l.tail) {
1786 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1787 }
1788 }
1789 return undef;
1790 }
1792 void checkNonCyclicDecl(JCClassDecl tree) {
1793 CycleChecker cc = new CycleChecker();
1794 cc.scan(tree);
1795 if (!cc.errorFound && !cc.partialCheck) {
1796 tree.sym.flags_field |= ACYCLIC;
1797 }
1798 }
1800 class CycleChecker extends TreeScanner {
1802 List<Symbol> seenClasses = List.nil();
1803 boolean errorFound = false;
1804 boolean partialCheck = false;
1806 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
1807 if (sym != null && sym.kind == TYP) {
1808 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
1809 if (classEnv != null) {
1810 DiagnosticSource prevSource = log.currentSource();
1811 try {
1812 log.useSource(classEnv.toplevel.sourcefile);
1813 scan(classEnv.tree);
1814 }
1815 finally {
1816 log.useSource(prevSource.getFile());
1817 }
1818 } else if (sym.kind == TYP) {
1819 checkClass(pos, sym, List.<JCTree>nil());
1820 }
1821 } else {
1822 //not completed yet
1823 partialCheck = true;
1824 }
1825 }
1827 @Override
1828 public void visitSelect(JCFieldAccess tree) {
1829 super.visitSelect(tree);
1830 checkSymbol(tree.pos(), tree.sym);
1831 }
1833 @Override
1834 public void visitIdent(JCIdent tree) {
1835 checkSymbol(tree.pos(), tree.sym);
1836 }
1838 @Override
1839 public void visitTypeApply(JCTypeApply tree) {
1840 scan(tree.clazz);
1841 }
1843 @Override
1844 public void visitTypeArray(JCArrayTypeTree tree) {
1845 scan(tree.elemtype);
1846 }
1848 @Override
1849 public void visitClassDef(JCClassDecl tree) {
1850 List<JCTree> supertypes = List.nil();
1851 if (tree.getExtendsClause() != null) {
1852 supertypes = supertypes.prepend(tree.getExtendsClause());
1853 }
1854 if (tree.getImplementsClause() != null) {
1855 for (JCTree intf : tree.getImplementsClause()) {
1856 supertypes = supertypes.prepend(intf);
1857 }
1858 }
1859 checkClass(tree.pos(), tree.sym, supertypes);
1860 }
1862 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
1863 if ((c.flags_field & ACYCLIC) != 0)
1864 return;
1865 if (seenClasses.contains(c)) {
1866 errorFound = true;
1867 noteCyclic(pos, (ClassSymbol)c);
1868 } else if (!c.type.isErroneous()) {
1869 try {
1870 seenClasses = seenClasses.prepend(c);
1871 if (c.type.tag == CLASS) {
1872 if (supertypes.nonEmpty()) {
1873 scan(supertypes);
1874 }
1875 else {
1876 ClassType ct = (ClassType)c.type;
1877 if (ct.supertype_field == null ||
1878 ct.interfaces_field == null) {
1879 //not completed yet
1880 partialCheck = true;
1881 return;
1882 }
1883 checkSymbol(pos, ct.supertype_field.tsym);
1884 for (Type intf : ct.interfaces_field) {
1885 checkSymbol(pos, intf.tsym);
1886 }
1887 }
1888 if (c.owner.kind == TYP) {
1889 checkSymbol(pos, c.owner);
1890 }
1891 }
1892 } finally {
1893 seenClasses = seenClasses.tail;
1894 }
1895 }
1896 }
1897 }
1899 /** Check for cyclic references. Issue an error if the
1900 * symbol of the type referred to has a LOCKED flag set.
1901 *
1902 * @param pos Position to be used for error reporting.
1903 * @param t The type referred to.
1904 */
1905 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1906 checkNonCyclicInternal(pos, t);
1907 }
1910 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1911 checkNonCyclic1(pos, t, List.<TypeVar>nil());
1912 }
1914 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
1915 final TypeVar tv;
1916 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1917 return;
1918 if (seen.contains(t)) {
1919 tv = (TypeVar)t;
1920 tv.bound = types.createErrorType(t);
1921 log.error(pos, "cyclic.inheritance", t);
1922 } else if (t.tag == TYPEVAR) {
1923 tv = (TypeVar)t;
1924 seen = seen.prepend(tv);
1925 for (Type b : types.getBounds(tv))
1926 checkNonCyclic1(pos, b, seen);
1927 }
1928 }
1930 /** Check for cyclic references. Issue an error if the
1931 * symbol of the type referred to has a LOCKED flag set.
1932 *
1933 * @param pos Position to be used for error reporting.
1934 * @param t The type referred to.
1935 * @returns True if the check completed on all attributed classes
1936 */
1937 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1938 boolean complete = true; // was the check complete?
1939 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1940 Symbol c = t.tsym;
1941 if ((c.flags_field & ACYCLIC) != 0) return true;
1943 if ((c.flags_field & LOCKED) != 0) {
1944 noteCyclic(pos, (ClassSymbol)c);
1945 } else if (!c.type.isErroneous()) {
1946 try {
1947 c.flags_field |= LOCKED;
1948 if (c.type.tag == CLASS) {
1949 ClassType clazz = (ClassType)c.type;
1950 if (clazz.interfaces_field != null)
1951 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1952 complete &= checkNonCyclicInternal(pos, l.head);
1953 if (clazz.supertype_field != null) {
1954 Type st = clazz.supertype_field;
1955 if (st != null && st.tag == CLASS)
1956 complete &= checkNonCyclicInternal(pos, st);
1957 }
1958 if (c.owner.kind == TYP)
1959 complete &= checkNonCyclicInternal(pos, c.owner.type);
1960 }
1961 } finally {
1962 c.flags_field &= ~LOCKED;
1963 }
1964 }
1965 if (complete)
1966 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1967 if (complete) c.flags_field |= ACYCLIC;
1968 return complete;
1969 }
1971 /** Note that we found an inheritance cycle. */
1972 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1973 log.error(pos, "cyclic.inheritance", c);
1974 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1975 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
1976 Type st = types.supertype(c.type);
1977 if (st.tag == CLASS)
1978 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
1979 c.type = types.createErrorType(c, c.type);
1980 c.flags_field |= ACYCLIC;
1981 }
1983 /** Check that all methods which implement some
1984 * method conform to the method they implement.
1985 * @param tree The class definition whose members are checked.
1986 */
1987 void checkImplementations(JCClassDecl tree) {
1988 checkImplementations(tree, tree.sym);
1989 }
1990 //where
1991 /** Check that all methods which implement some
1992 * method in `ic' conform to the method they implement.
1993 */
1994 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
1995 ClassSymbol origin = tree.sym;
1996 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
1997 ClassSymbol lc = (ClassSymbol)l.head.tsym;
1998 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
1999 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
2000 if (e.sym.kind == MTH &&
2001 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2002 MethodSymbol absmeth = (MethodSymbol)e.sym;
2003 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2004 if (implmeth != null && implmeth != absmeth &&
2005 (implmeth.owner.flags() & INTERFACE) ==
2006 (origin.flags() & INTERFACE)) {
2007 // don't check if implmeth is in a class, yet
2008 // origin is an interface. This case arises only
2009 // if implmeth is declared in Object. The reason is
2010 // that interfaces really don't inherit from
2011 // Object it's just that the compiler represents
2012 // things that way.
2013 checkOverride(tree, implmeth, absmeth, origin);
2014 }
2015 }
2016 }
2017 }
2018 }
2019 }
2021 /** Check that all abstract methods implemented by a class are
2022 * mutually compatible.
2023 * @param pos Position to be used for error reporting.
2024 * @param c The class whose interfaces are checked.
2025 */
2026 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2027 List<Type> supertypes = types.interfaces(c);
2028 Type supertype = types.supertype(c);
2029 if (supertype.tag == CLASS &&
2030 (supertype.tsym.flags() & ABSTRACT) != 0)
2031 supertypes = supertypes.prepend(supertype);
2032 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2033 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
2034 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2035 return;
2036 for (List<Type> m = supertypes; m != l; m = m.tail)
2037 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2038 return;
2039 }
2040 checkCompatibleConcretes(pos, c);
2041 }
2043 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
2044 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
2045 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
2046 // VM allows methods and variables with differing types
2047 if (sym.kind == e.sym.kind &&
2048 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
2049 sym != e.sym &&
2050 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
2051 (sym.flags() & IPROXY) == 0 && (e.sym.flags() & IPROXY) == 0 &&
2052 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
2053 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
2054 return;
2055 }
2056 }
2057 }
2058 }
2060 /** Check that all non-override equivalent methods accessible from 'site'
2061 * are mutually compatible (JLS 8.4.8/9.4.1).
2062 *
2063 * @param pos Position to be used for error reporting.
2064 * @param site The class whose methods are checked.
2065 * @param sym The method symbol to be checked.
2066 */
2067 void checkClashes(DiagnosticPosition pos, Type site, Symbol sym) {
2068 List<Type> supertypes = types.closure(site);
2069 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2070 for (List<Type> m = supertypes; m.nonEmpty(); m = m.tail) {
2071 checkClashes(pos, l.head, m.head, site, sym);
2072 }
2073 }
2074 }
2076 /** Reports an error whenever 'sym' seen as a member of type 't1' clashes with
2077 * some unrelated method defined in 't2'.
2078 */
2079 private void checkClashes(DiagnosticPosition pos, Type t1, Type t2, Type site, Symbol s1) {
2080 ClashFilter cf = new ClashFilter(site);
2081 s1 = ((MethodSymbol)s1).implementedIn(t1.tsym, types);
2082 if (s1 == null) return;
2083 Type st1 = types.memberType(site, s1);
2084 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name, cf); e2.scope != null; e2 = e2.next(cf)) {
2085 Symbol s2 = e2.sym;
2086 if (s1 == s2) continue;
2087 Type st2 = types.memberType(site, s2);
2088 if (!types.overrideEquivalent(st1, st2) &&
2089 !checkNameClash((ClassSymbol)site.tsym, s1, s2)) {
2090 log.error(pos,
2091 "name.clash.same.erasure.no.override",
2092 s1, s1.location(),
2093 s2, s2.location());
2094 }
2095 }
2096 }
2097 //where
2098 private class ClashFilter implements Filter<Symbol> {
2100 Type site;
2102 ClashFilter(Type site) {
2103 this.site = site;
2104 }
2106 public boolean accepts(Symbol s) {
2107 return s.kind == MTH &&
2108 (s.flags() & SYNTHETIC) == 0 &&
2109 s.isInheritedIn(site.tsym, types) &&
2110 !s.isConstructor();
2111 }
2112 }
2114 /** Report a conflict between a user symbol and a synthetic symbol.
2115 */
2116 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
2117 if (!sym.type.isErroneous()) {
2118 if (warnOnSyntheticConflicts) {
2119 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
2120 }
2121 else {
2122 log.error(pos, "synthetic.name.conflict", sym, sym.location());
2123 }
2124 }
2125 }
2127 /** Check that class c does not implement directly or indirectly
2128 * the same parameterized interface with two different argument lists.
2129 * @param pos Position to be used for error reporting.
2130 * @param type The type whose interfaces are checked.
2131 */
2132 void checkClassBounds(DiagnosticPosition pos, Type type) {
2133 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
2134 }
2135 //where
2136 /** Enter all interfaces of type `type' into the hash table `seensofar'
2137 * with their class symbol as key and their type as value. Make
2138 * sure no class is entered with two different types.
2139 */
2140 void checkClassBounds(DiagnosticPosition pos,
2141 Map<TypeSymbol,Type> seensofar,
2142 Type type) {
2143 if (type.isErroneous()) return;
2144 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
2145 Type it = l.head;
2146 Type oldit = seensofar.put(it.tsym, it);
2147 if (oldit != null) {
2148 List<Type> oldparams = oldit.allparams();
2149 List<Type> newparams = it.allparams();
2150 if (!types.containsTypeEquivalent(oldparams, newparams))
2151 log.error(pos, "cant.inherit.diff.arg",
2152 it.tsym, Type.toString(oldparams),
2153 Type.toString(newparams));
2154 }
2155 checkClassBounds(pos, seensofar, it);
2156 }
2157 Type st = types.supertype(type);
2158 if (st != null) checkClassBounds(pos, seensofar, st);
2159 }
2161 /** Enter interface into into set.
2162 * If it existed already, issue a "repeated interface" error.
2163 */
2164 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
2165 if (its.contains(it))
2166 log.error(pos, "repeated.interface");
2167 else {
2168 its.add(it);
2169 }
2170 }
2172 /* *************************************************************************
2173 * Check annotations
2174 **************************************************************************/
2176 /**
2177 * Recursively validate annotations values
2178 */
2179 void validateAnnotationTree(JCTree tree) {
2180 class AnnotationValidator extends TreeScanner {
2181 @Override
2182 public void visitAnnotation(JCAnnotation tree) {
2183 super.visitAnnotation(tree);
2184 validateAnnotation(tree);
2185 }
2186 }
2187 tree.accept(new AnnotationValidator());
2188 }
2190 /** Annotation types are restricted to primitives, String, an
2191 * enum, an annotation, Class, Class<?>, Class<? extends
2192 * Anything>, arrays of the preceding.
2193 */
2194 void validateAnnotationType(JCTree restype) {
2195 // restype may be null if an error occurred, so don't bother validating it
2196 if (restype != null) {
2197 validateAnnotationType(restype.pos(), restype.type);
2198 }
2199 }
2201 void validateAnnotationType(DiagnosticPosition pos, Type type) {
2202 if (type.isPrimitive()) return;
2203 if (types.isSameType(type, syms.stringType)) return;
2204 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
2205 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
2206 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
2207 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
2208 validateAnnotationType(pos, types.elemtype(type));
2209 return;
2210 }
2211 log.error(pos, "invalid.annotation.member.type");
2212 }
2214 /**
2215 * "It is also a compile-time error if any method declared in an
2216 * annotation type has a signature that is override-equivalent to
2217 * that of any public or protected method declared in class Object
2218 * or in the interface annotation.Annotation."
2219 *
2220 * @jls3 9.6 Annotation Types
2221 */
2222 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
2223 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
2224 Scope s = sup.tsym.members();
2225 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
2226 if (e.sym.kind == MTH &&
2227 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
2228 types.overrideEquivalent(m.type, e.sym.type))
2229 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
2230 }
2231 }
2232 }
2234 /** Check the annotations of a symbol.
2235 */
2236 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
2237 if (skipAnnotations) return;
2238 for (JCAnnotation a : annotations)
2239 validateAnnotation(a, s);
2240 }
2242 /** Check the type annotations
2243 */
2244 public void validateTypeAnnotations(List<JCTypeAnnotation> annotations, boolean isTypeParameter) {
2245 if (skipAnnotations) return;
2246 for (JCTypeAnnotation a : annotations)
2247 validateTypeAnnotation(a, isTypeParameter);
2248 }
2250 /** Check an annotation of a symbol.
2251 */
2252 public void validateAnnotation(JCAnnotation a, Symbol s) {
2253 validateAnnotationTree(a);
2255 if (!annotationApplicable(a, s))
2256 log.error(a.pos(), "annotation.type.not.applicable");
2258 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2259 if (!isOverrider(s))
2260 log.error(a.pos(), "method.does.not.override.superclass");
2261 }
2262 }
2264 public void validateTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
2265 if (a.type == null)
2266 throw new AssertionError("annotation tree hasn't been attributed yet: " + a);
2267 validateAnnotationTree(a);
2269 if (!isTypeAnnotation(a, isTypeParameter))
2270 log.error(a.pos(), "annotation.type.not.applicable");
2271 }
2273 /** Is s a method symbol that overrides a method in a superclass? */
2274 boolean isOverrider(Symbol s) {
2275 if (s.kind != MTH || s.isStatic())
2276 return false;
2277 MethodSymbol m = (MethodSymbol)s;
2278 TypeSymbol owner = (TypeSymbol)m.owner;
2279 for (Type sup : types.closure(owner.type)) {
2280 if (sup == owner.type)
2281 continue; // skip "this"
2282 Scope scope = sup.tsym.members();
2283 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
2284 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
2285 return true;
2286 }
2287 }
2288 return false;
2289 }
2291 /** Is the annotation applicable to type annotations */
2292 boolean isTypeAnnotation(JCTypeAnnotation a, boolean isTypeParameter) {
2293 Attribute.Compound atTarget =
2294 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2295 if (atTarget == null) return true;
2296 Attribute atValue = atTarget.member(names.value);
2297 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2298 Attribute.Array arr = (Attribute.Array) atValue;
2299 for (Attribute app : arr.values) {
2300 if (!(app instanceof Attribute.Enum)) return true; // recovery
2301 Attribute.Enum e = (Attribute.Enum) app;
2302 if (!isTypeParameter && e.value.name == names.TYPE_USE)
2303 return true;
2304 else if (isTypeParameter && e.value.name == names.TYPE_PARAMETER)
2305 return true;
2306 }
2307 return false;
2308 }
2310 /** Is the annotation applicable to the symbol? */
2311 boolean annotationApplicable(JCAnnotation a, Symbol s) {
2312 Attribute.Compound atTarget =
2313 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2314 if (atTarget == null) return true;
2315 Attribute atValue = atTarget.member(names.value);
2316 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2317 Attribute.Array arr = (Attribute.Array) atValue;
2318 for (Attribute app : arr.values) {
2319 if (!(app instanceof Attribute.Enum)) return true; // recovery
2320 Attribute.Enum e = (Attribute.Enum) app;
2321 if (e.value.name == names.TYPE)
2322 { if (s.kind == TYP) return true; }
2323 else if (e.value.name == names.FIELD)
2324 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
2325 else if (e.value.name == names.METHOD)
2326 { if (s.kind == MTH && !s.isConstructor()) return true; }
2327 else if (e.value.name == names.PARAMETER)
2328 { if (s.kind == VAR &&
2329 s.owner.kind == MTH &&
2330 (s.flags() & PARAMETER) != 0)
2331 return true;
2332 }
2333 else if (e.value.name == names.CONSTRUCTOR)
2334 { if (s.kind == MTH && s.isConstructor()) return true; }
2335 else if (e.value.name == names.LOCAL_VARIABLE)
2336 { if (s.kind == VAR && s.owner.kind == MTH &&
2337 (s.flags() & PARAMETER) == 0)
2338 return true;
2339 }
2340 else if (e.value.name == names.ANNOTATION_TYPE)
2341 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
2342 return true;
2343 }
2344 else if (e.value.name == names.PACKAGE)
2345 { if (s.kind == PCK) return true; }
2346 else if (e.value.name == names.TYPE_USE)
2347 { if (s.kind == TYP ||
2348 s.kind == VAR ||
2349 (s.kind == MTH && !s.isConstructor() &&
2350 s.type.getReturnType().tag != VOID))
2351 return true;
2352 }
2353 else
2354 return true; // recovery
2355 }
2356 return false;
2357 }
2359 /** Check an annotation value.
2360 */
2361 public void validateAnnotation(JCAnnotation a) {
2362 if (a.type.isErroneous()) return;
2364 // collect an inventory of the members (sorted alphabetically)
2365 Set<MethodSymbol> members = new TreeSet<MethodSymbol>(new Comparator<Symbol>() {
2366 public int compare(Symbol t, Symbol t1) {
2367 return t.name.compareTo(t1.name);
2368 }
2369 });
2370 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
2371 e != null;
2372 e = e.sibling)
2373 if (e.sym.kind == MTH)
2374 members.add((MethodSymbol) e.sym);
2376 // count them off as they're annotated
2377 for (JCTree arg : a.args) {
2378 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
2379 JCAssign assign = (JCAssign) arg;
2380 Symbol m = TreeInfo.symbol(assign.lhs);
2381 if (m == null || m.type.isErroneous()) continue;
2382 if (!members.remove(m))
2383 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
2384 m.name, a.type);
2385 }
2387 // all the remaining ones better have default values
2388 ListBuffer<Name> missingDefaults = ListBuffer.lb();
2389 for (MethodSymbol m : members) {
2390 if (m.defaultValue == null && !m.type.isErroneous()) {
2391 missingDefaults.append(m.name);
2392 }
2393 }
2394 if (missingDefaults.nonEmpty()) {
2395 String key = (missingDefaults.size() > 1)
2396 ? "annotation.missing.default.value.1"
2397 : "annotation.missing.default.value";
2398 log.error(a.pos(), key, a.type, missingDefaults);
2399 }
2401 // special case: java.lang.annotation.Target must not have
2402 // repeated values in its value member
2403 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
2404 a.args.tail == null)
2405 return;
2407 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
2408 JCAssign assign = (JCAssign) a.args.head;
2409 Symbol m = TreeInfo.symbol(assign.lhs);
2410 if (m.name != names.value) return;
2411 JCTree rhs = assign.rhs;
2412 if (rhs.getTag() != JCTree.NEWARRAY) return;
2413 JCNewArray na = (JCNewArray) rhs;
2414 Set<Symbol> targets = new HashSet<Symbol>();
2415 for (JCTree elem : na.elems) {
2416 if (!targets.add(TreeInfo.symbol(elem))) {
2417 log.error(elem.pos(), "repeated.annotation.target");
2418 }
2419 }
2420 }
2422 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
2423 if (allowAnnotations &&
2424 lint.isEnabled(LintCategory.DEP_ANN) &&
2425 (s.flags() & DEPRECATED) != 0 &&
2426 !syms.deprecatedType.isErroneous() &&
2427 s.attribute(syms.deprecatedType.tsym) == null) {
2428 log.warning(LintCategory.DEP_ANN,
2429 pos, "missing.deprecated.annotation");
2430 }
2431 }
2433 /* *************************************************************************
2434 * Check for recursive annotation elements.
2435 **************************************************************************/
2437 /** Check for cycles in the graph of annotation elements.
2438 */
2439 void checkNonCyclicElements(JCClassDecl tree) {
2440 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
2441 assert (tree.sym.flags_field & LOCKED) == 0;
2442 try {
2443 tree.sym.flags_field |= LOCKED;
2444 for (JCTree def : tree.defs) {
2445 if (def.getTag() != JCTree.METHODDEF) continue;
2446 JCMethodDecl meth = (JCMethodDecl)def;
2447 checkAnnotationResType(meth.pos(), meth.restype.type);
2448 }
2449 } finally {
2450 tree.sym.flags_field &= ~LOCKED;
2451 tree.sym.flags_field |= ACYCLIC_ANN;
2452 }
2453 }
2455 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
2456 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
2457 return;
2458 if ((tsym.flags_field & LOCKED) != 0) {
2459 log.error(pos, "cyclic.annotation.element");
2460 return;
2461 }
2462 try {
2463 tsym.flags_field |= LOCKED;
2464 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
2465 Symbol s = e.sym;
2466 if (s.kind != Kinds.MTH)
2467 continue;
2468 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
2469 }
2470 } finally {
2471 tsym.flags_field &= ~LOCKED;
2472 tsym.flags_field |= ACYCLIC_ANN;
2473 }
2474 }
2476 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
2477 switch (type.tag) {
2478 case TypeTags.CLASS:
2479 if ((type.tsym.flags() & ANNOTATION) != 0)
2480 checkNonCyclicElementsInternal(pos, type.tsym);
2481 break;
2482 case TypeTags.ARRAY:
2483 checkAnnotationResType(pos, types.elemtype(type));
2484 break;
2485 default:
2486 break; // int etc
2487 }
2488 }
2490 /* *************************************************************************
2491 * Check for cycles in the constructor call graph.
2492 **************************************************************************/
2494 /** Check for cycles in the graph of constructors calling other
2495 * constructors.
2496 */
2497 void checkCyclicConstructors(JCClassDecl tree) {
2498 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
2500 // enter each constructor this-call into the map
2501 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2502 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
2503 if (app == null) continue;
2504 JCMethodDecl meth = (JCMethodDecl) l.head;
2505 if (TreeInfo.name(app.meth) == names._this) {
2506 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
2507 } else {
2508 meth.sym.flags_field |= ACYCLIC;
2509 }
2510 }
2512 // Check for cycles in the map
2513 Symbol[] ctors = new Symbol[0];
2514 ctors = callMap.keySet().toArray(ctors);
2515 for (Symbol caller : ctors) {
2516 checkCyclicConstructor(tree, caller, callMap);
2517 }
2518 }
2520 /** Look in the map to see if the given constructor is part of a
2521 * call cycle.
2522 */
2523 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2524 Map<Symbol,Symbol> callMap) {
2525 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2526 if ((ctor.flags_field & LOCKED) != 0) {
2527 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2528 "recursive.ctor.invocation");
2529 } else {
2530 ctor.flags_field |= LOCKED;
2531 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2532 ctor.flags_field &= ~LOCKED;
2533 }
2534 ctor.flags_field |= ACYCLIC;
2535 }
2536 }
2538 /* *************************************************************************
2539 * Miscellaneous
2540 **************************************************************************/
2542 /**
2543 * Return the opcode of the operator but emit an error if it is an
2544 * error.
2545 * @param pos position for error reporting.
2546 * @param operator an operator
2547 * @param tag a tree tag
2548 * @param left type of left hand side
2549 * @param right type of right hand side
2550 */
2551 int checkOperator(DiagnosticPosition pos,
2552 OperatorSymbol operator,
2553 int tag,
2554 Type left,
2555 Type right) {
2556 if (operator.opcode == ByteCodes.error) {
2557 log.error(pos,
2558 "operator.cant.be.applied",
2559 treeinfo.operatorName(tag),
2560 List.of(left, right));
2561 }
2562 return operator.opcode;
2563 }
2566 /**
2567 * Check for division by integer constant zero
2568 * @param pos Position for error reporting.
2569 * @param operator The operator for the expression
2570 * @param operand The right hand operand for the expression
2571 */
2572 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2573 if (operand.constValue() != null
2574 && lint.isEnabled(LintCategory.DIVZERO)
2575 && operand.tag <= LONG
2576 && ((Number) (operand.constValue())).longValue() == 0) {
2577 int opc = ((OperatorSymbol)operator).opcode;
2578 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2579 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2580 log.warning(LintCategory.DIVZERO, pos, "div.zero");
2581 }
2582 }
2583 }
2585 /**
2586 * Check for empty statements after if
2587 */
2588 void checkEmptyIf(JCIf tree) {
2589 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(LintCategory.EMPTY))
2590 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), "empty.if");
2591 }
2593 /** Check that symbol is unique in given scope.
2594 * @param pos Position for error reporting.
2595 * @param sym The symbol.
2596 * @param s The scope.
2597 */
2598 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2599 if (sym.type.isErroneous())
2600 return true;
2601 if (sym.owner.name == names.any) return false;
2602 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2603 if (sym != e.sym &&
2604 sym.kind == e.sym.kind &&
2605 sym.name != names.error &&
2606 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
2607 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
2608 varargsDuplicateError(pos, sym, e.sym);
2609 else if (sym.kind == MTH && !types.overrideEquivalent(sym.type, e.sym.type))
2610 duplicateErasureError(pos, sym, e.sym);
2611 else
2612 duplicateError(pos, e.sym);
2613 return false;
2614 }
2615 }
2616 return true;
2617 }
2618 //where
2619 /** Report duplicate declaration error.
2620 */
2621 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
2622 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
2623 log.error(pos, "name.clash.same.erasure", sym1, sym2);
2624 }
2625 }
2627 /** Check that single-type import is not already imported or top-level defined,
2628 * but make an exception for two single-type imports which denote the same type.
2629 * @param pos Position for error reporting.
2630 * @param sym The symbol.
2631 * @param s The scope
2632 */
2633 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2634 return checkUniqueImport(pos, sym, s, false);
2635 }
2637 /** Check that static single-type import is not already imported or top-level defined,
2638 * but make an exception for two single-type imports which denote the same type.
2639 * @param pos Position for error reporting.
2640 * @param sym The symbol.
2641 * @param s The scope
2642 * @param staticImport Whether or not this was a static import
2643 */
2644 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2645 return checkUniqueImport(pos, sym, s, true);
2646 }
2648 /** Check that single-type import is not already imported or top-level defined,
2649 * but make an exception for two single-type imports which denote the same type.
2650 * @param pos Position for error reporting.
2651 * @param sym The symbol.
2652 * @param s The scope.
2653 * @param staticImport Whether or not this was a static import
2654 */
2655 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2656 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2657 // is encountered class entered via a class declaration?
2658 boolean isClassDecl = e.scope == s;
2659 if ((isClassDecl || sym != e.sym) &&
2660 sym.kind == e.sym.kind &&
2661 sym.name != names.error) {
2662 if (!e.sym.type.isErroneous()) {
2663 String what = e.sym.toString();
2664 if (!isClassDecl) {
2665 if (staticImport)
2666 log.error(pos, "already.defined.static.single.import", what);
2667 else
2668 log.error(pos, "already.defined.single.import", what);
2669 }
2670 else if (sym != e.sym)
2671 log.error(pos, "already.defined.this.unit", what);
2672 }
2673 return false;
2674 }
2675 }
2676 return true;
2677 }
2679 /** Check that a qualified name is in canonical form (for import decls).
2680 */
2681 public void checkCanonical(JCTree tree) {
2682 if (!isCanonical(tree))
2683 log.error(tree.pos(), "import.requires.canonical",
2684 TreeInfo.symbol(tree));
2685 }
2686 // where
2687 private boolean isCanonical(JCTree tree) {
2688 while (tree.getTag() == JCTree.SELECT) {
2689 JCFieldAccess s = (JCFieldAccess) tree;
2690 if (s.sym.owner != TreeInfo.symbol(s.selected))
2691 return false;
2692 tree = s.selected;
2693 }
2694 return true;
2695 }
2697 private class ConversionWarner extends Warner {
2698 final String uncheckedKey;
2699 final Type found;
2700 final Type expected;
2701 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
2702 super(pos);
2703 this.uncheckedKey = uncheckedKey;
2704 this.found = found;
2705 this.expected = expected;
2706 }
2708 @Override
2709 public void warn(LintCategory lint) {
2710 boolean warned = this.warned;
2711 super.warn(lint);
2712 if (warned) return; // suppress redundant diagnostics
2713 switch (lint) {
2714 case UNCHECKED:
2715 Check.this.warnUnchecked(pos(), "prob.found.req", diags.fragment(uncheckedKey), found, expected);
2716 break;
2717 case VARARGS:
2718 if (method != null &&
2719 method.attribute(syms.trustMeType.tsym) != null &&
2720 isTrustMeAllowedOnMethod(method) &&
2721 !types.isReifiable(method.type.getParameterTypes().last())) {
2722 Check.this.warnUnsafeVararg(pos(), "varargs.unsafe.use.varargs.param", method.params.last());
2723 }
2724 break;
2725 default:
2726 throw new AssertionError("Unexpected lint: " + lint);
2727 }
2728 }
2729 }
2731 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2732 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2733 }
2735 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2736 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2737 }
2738 }
