Mercurial > jdk8-mips64-public > langtools / file revision
src/share/classes/com/sun/tools/javac/comp/Check.java@ce6175cfe11e
src/share/classes/com/sun/tools/javac/comp/Check.java
Mon, 24 Jan 2011 15:44:51 +0000
- author
- mcimadamore
- date
- Mon, 24 Jan 2011 15:44:51 +0000
- changeset 829
- ce6175cfe11e
- parent 828
- 19c900c703c6
- child 844
- 2088e674f0e0
- permissions
- -rw-r--r--
6968793: issues with diagnostics
Summary: several diagnostic improvements
Reviewed-by: jjg
1 /*
2 * Copyright (c) 1999, 2011, 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 boolean checkExtends(Type a, TypeVar bs) {
510 if (a.isUnbound()) {
511 return true;
512 } else if (a.tag != WILDCARD) {
513 a = types.upperBound(a);
514 return types.isSubtype(a, bs.bound);
515 } else if (a.isExtendsBound()) {
516 return types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings);
517 } else if (a.isSuperBound()) {
518 return !types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound());
519 }
520 return true;
521 }
523 /** Check that type is different from 'void'.
524 * @param pos Position to be used for error reporting.
525 * @param t The type to be checked.
526 */
527 Type checkNonVoid(DiagnosticPosition pos, Type t) {
528 if (t.tag == VOID) {
529 log.error(pos, "void.not.allowed.here");
530 return types.createErrorType(t);
531 } else {
532 return t;
533 }
534 }
536 /** Check that type is a class or interface type.
537 * @param pos Position to be used for error reporting.
538 * @param t The type to be checked.
539 */
540 Type checkClassType(DiagnosticPosition pos, Type t) {
541 if (t.tag != CLASS && t.tag != ERROR)
542 return typeTagError(pos,
543 diags.fragment("type.req.class"),
544 (t.tag == TYPEVAR)
545 ? diags.fragment("type.parameter", t)
546 : t);
547 else
548 return t;
549 }
551 /** Check that type is a class or interface type.
552 * @param pos Position to be used for error reporting.
553 * @param t The type to be checked.
554 * @param noBounds True if type bounds are illegal here.
555 */
556 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
557 t = checkClassType(pos, t);
558 if (noBounds && t.isParameterized()) {
559 List<Type> args = t.getTypeArguments();
560 while (args.nonEmpty()) {
561 if (args.head.tag == WILDCARD)
562 return typeTagError(pos,
563 diags.fragment("type.req.exact"),
564 args.head);
565 args = args.tail;
566 }
567 }
568 return t;
569 }
571 /** Check that type is a reifiable class, interface or array type.
572 * @param pos Position to be used for error reporting.
573 * @param t The type to be checked.
574 */
575 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
576 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
577 return typeTagError(pos,
578 diags.fragment("type.req.class.array"),
579 t);
580 } else if (!types.isReifiable(t)) {
581 log.error(pos, "illegal.generic.type.for.instof");
582 return types.createErrorType(t);
583 } else {
584 return t;
585 }
586 }
588 /** Check that type is a reference type, i.e. a class, interface or array type
589 * or a type variable.
590 * @param pos Position to be used for error reporting.
591 * @param t The type to be checked.
592 */
593 Type checkRefType(DiagnosticPosition pos, Type t) {
594 switch (t.tag) {
595 case CLASS:
596 case ARRAY:
597 case TYPEVAR:
598 case WILDCARD:
599 case ERROR:
600 return t;
601 default:
602 return typeTagError(pos,
603 diags.fragment("type.req.ref"),
604 t);
605 }
606 }
608 /** Check that each type is a reference type, i.e. a class, interface or array type
609 * or a type variable.
610 * @param trees Original trees, used for error reporting.
611 * @param types The types to be checked.
612 */
613 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
614 List<JCExpression> tl = trees;
615 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
616 l.head = checkRefType(tl.head.pos(), l.head);
617 tl = tl.tail;
618 }
619 return types;
620 }
622 /** Check that type is a null or reference type.
623 * @param pos Position to be used for error reporting.
624 * @param t The type to be checked.
625 */
626 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
627 switch (t.tag) {
628 case CLASS:
629 case ARRAY:
630 case TYPEVAR:
631 case WILDCARD:
632 case BOT:
633 case ERROR:
634 return t;
635 default:
636 return typeTagError(pos,
637 diags.fragment("type.req.ref"),
638 t);
639 }
640 }
642 /** Check that flag set does not contain elements of two conflicting sets. s
643 * Return true if it doesn't.
644 * @param pos Position to be used for error reporting.
645 * @param flags The set of flags to be checked.
646 * @param set1 Conflicting flags set #1.
647 * @param set2 Conflicting flags set #2.
648 */
649 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
650 if ((flags & set1) != 0 && (flags & set2) != 0) {
651 log.error(pos,
652 "illegal.combination.of.modifiers",
653 asFlagSet(TreeInfo.firstFlag(flags & set1)),
654 asFlagSet(TreeInfo.firstFlag(flags & set2)));
655 return false;
656 } else
657 return true;
658 }
660 /** Check that the type inferred using the diamond operator does not contain
661 * non-denotable types such as captured types or intersection types.
662 * @param t the type inferred using the diamond operator
663 */
664 List<Type> checkDiamond(ClassType t) {
665 DiamondTypeChecker dtc = new DiamondTypeChecker();
666 ListBuffer<Type> buf = ListBuffer.lb();
667 for (Type arg : t.getTypeArguments()) {
668 if (!dtc.visit(arg, null)) {
669 buf.append(arg);
670 }
671 }
672 return buf.toList();
673 }
675 static class DiamondTypeChecker extends Types.SimpleVisitor<Boolean, Void> {
676 public Boolean visitType(Type t, Void s) {
677 return true;
678 }
679 @Override
680 public Boolean visitClassType(ClassType t, Void s) {
681 if (t.isCompound()) {
682 return false;
683 }
684 for (Type targ : t.getTypeArguments()) {
685 if (!visit(targ, s)) {
686 return false;
687 }
688 }
689 return true;
690 }
691 @Override
692 public Boolean visitCapturedType(CapturedType t, Void s) {
693 return false;
694 }
695 }
697 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
698 MethodSymbol m = tree.sym;
699 if (!allowSimplifiedVarargs) return;
700 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
701 Type varargElemType = null;
702 if (m.isVarArgs()) {
703 varargElemType = types.elemtype(tree.params.last().type);
704 }
705 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
706 if (varargElemType != null) {
707 log.error(tree,
708 "varargs.invalid.trustme.anno",
709 syms.trustMeType.tsym,
710 diags.fragment("varargs.trustme.on.virtual.varargs", m));
711 } else {
712 log.error(tree,
713 "varargs.invalid.trustme.anno",
714 syms.trustMeType.tsym,
715 diags.fragment("varargs.trustme.on.non.varargs.meth", m));
716 }
717 } else if (hasTrustMeAnno && varargElemType != null &&
718 types.isReifiable(varargElemType)) {
719 warnUnsafeVararg(tree,
720 "varargs.redundant.trustme.anno",
721 syms.trustMeType.tsym,
722 diags.fragment("varargs.trustme.on.reifiable.varargs", varargElemType));
723 }
724 else if (!hasTrustMeAnno && varargElemType != null &&
725 !types.isReifiable(varargElemType)) {
726 warnUnchecked(tree.params.head.pos(), "unchecked.varargs.non.reifiable.type", varargElemType);
727 }
728 }
729 //where
730 private boolean isTrustMeAllowedOnMethod(Symbol s) {
731 return (s.flags() & VARARGS) != 0 &&
732 (s.isConstructor() ||
733 (s.flags() & (STATIC | FINAL)) != 0);
734 }
736 /**
737 * Check that vararg method call is sound
738 * @param pos Position to be used for error reporting.
739 * @param argtypes Actual arguments supplied to vararg method.
740 */
741 void checkVararg(DiagnosticPosition pos, List<Type> argtypes, Symbol msym) {
742 Type argtype = argtypes.last();
743 if (!types.isReifiable(argtype) &&
744 (!allowSimplifiedVarargs ||
745 msym.attribute(syms.trustMeType.tsym) == null ||
746 !isTrustMeAllowedOnMethod(msym))) {
747 warnUnchecked(pos,
748 "unchecked.generic.array.creation",
749 argtype);
750 }
751 }
753 /**
754 * Check that type 't' is a valid instantiation of a generic class
755 * (see JLS 4.5)
756 *
757 * @param t class type to be checked
758 * @return true if 't' is well-formed
759 */
760 public boolean checkValidGenericType(Type t) {
761 return firstIncompatibleTypeArg(t) == null;
762 }
763 //WHERE
764 private Type firstIncompatibleTypeArg(Type type) {
765 List<Type> formals = type.tsym.type.allparams();
766 List<Type> actuals = type.allparams();
767 List<Type> args = type.getTypeArguments();
768 List<Type> forms = type.tsym.type.getTypeArguments();
769 ListBuffer<Type> tvars_buf = new ListBuffer<Type>();
771 // For matching pairs of actual argument types `a' and
772 // formal type parameters with declared bound `b' ...
773 while (args.nonEmpty() && forms.nonEmpty()) {
774 // exact type arguments needs to know their
775 // bounds (for upper and lower bound
776 // calculations). So we create new TypeVars with
777 // bounds substed with actuals.
778 tvars_buf.append(types.substBound(((TypeVar)forms.head),
779 formals,
780 actuals));
781 args = args.tail;
782 forms = forms.tail;
783 }
785 args = type.getTypeArguments();
786 List<Type> tvars_cap = types.substBounds(formals,
787 formals,
788 types.capture(type).allparams());
789 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
790 // Let the actual arguments know their bound
791 args.head.withTypeVar((TypeVar)tvars_cap.head);
792 args = args.tail;
793 tvars_cap = tvars_cap.tail;
794 }
796 args = type.getTypeArguments();
797 List<Type> tvars = tvars_buf.toList();
799 while (args.nonEmpty() && tvars.nonEmpty()) {
800 Type actual = types.subst(args.head,
801 type.tsym.type.getTypeArguments(),
802 tvars_buf.toList());
803 if (!checkExtends(actual, (TypeVar)tvars.head) &&
804 !tvars.head.getUpperBound().isErroneous()) {
805 return args.head;
806 }
807 args = args.tail;
808 tvars = tvars.tail;
809 }
811 args = type.getTypeArguments();
812 tvars = tvars_buf.toList();
814 for (Type arg : types.capture(type).getTypeArguments()) {
815 if (arg.tag == TYPEVAR &&
816 arg.getUpperBound().isErroneous() &&
817 !tvars.head.getUpperBound().isErroneous()) {
818 return args.head;
819 }
820 tvars = tvars.tail;
821 }
823 return null;
824 }
826 /** Check that given modifiers are legal for given symbol and
827 * return modifiers together with any implicit modififiers for that symbol.
828 * Warning: we can't use flags() here since this method
829 * is called during class enter, when flags() would cause a premature
830 * completion.
831 * @param pos Position to be used for error reporting.
832 * @param flags The set of modifiers given in a definition.
833 * @param sym The defined symbol.
834 */
835 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
836 long mask;
837 long implicit = 0;
838 switch (sym.kind) {
839 case VAR:
840 if (sym.owner.kind != TYP)
841 mask = LocalVarFlags;
842 else if ((sym.owner.flags_field & INTERFACE) != 0)
843 mask = implicit = InterfaceVarFlags;
844 else
845 mask = VarFlags;
846 break;
847 case MTH:
848 if (sym.name == names.init) {
849 if ((sym.owner.flags_field & ENUM) != 0) {
850 // enum constructors cannot be declared public or
851 // protected and must be implicitly or explicitly
852 // private
853 implicit = PRIVATE;
854 mask = PRIVATE;
855 } else
856 mask = ConstructorFlags;
857 } else if ((sym.owner.flags_field & INTERFACE) != 0)
858 mask = implicit = InterfaceMethodFlags;
859 else {
860 mask = MethodFlags;
861 }
862 // Imply STRICTFP if owner has STRICTFP set.
863 if (((flags|implicit) & Flags.ABSTRACT) == 0)
864 implicit |= sym.owner.flags_field & STRICTFP;
865 break;
866 case TYP:
867 if (sym.isLocal()) {
868 mask = LocalClassFlags;
869 if (sym.name.isEmpty()) { // Anonymous class
870 // Anonymous classes in static methods are themselves static;
871 // that's why we admit STATIC here.
872 mask |= STATIC;
873 // JLS: Anonymous classes are final.
874 implicit |= FINAL;
875 }
876 if ((sym.owner.flags_field & STATIC) == 0 &&
877 (flags & ENUM) != 0)
878 log.error(pos, "enums.must.be.static");
879 } else if (sym.owner.kind == TYP) {
880 mask = MemberClassFlags;
881 if (sym.owner.owner.kind == PCK ||
882 (sym.owner.flags_field & STATIC) != 0)
883 mask |= STATIC;
884 else if ((flags & ENUM) != 0)
885 log.error(pos, "enums.must.be.static");
886 // Nested interfaces and enums are always STATIC (Spec ???)
887 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
888 } else {
889 mask = ClassFlags;
890 }
891 // Interfaces are always ABSTRACT
892 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
894 if ((flags & ENUM) != 0) {
895 // enums can't be declared abstract or final
896 mask &= ~(ABSTRACT | FINAL);
897 implicit |= implicitEnumFinalFlag(tree);
898 }
899 // Imply STRICTFP if owner has STRICTFP set.
900 implicit |= sym.owner.flags_field & STRICTFP;
901 break;
902 default:
903 throw new AssertionError();
904 }
905 long illegal = flags & StandardFlags & ~mask;
906 if (illegal != 0) {
907 if ((illegal & INTERFACE) != 0) {
908 log.error(pos, "intf.not.allowed.here");
909 mask |= INTERFACE;
910 }
911 else {
912 log.error(pos,
913 "mod.not.allowed.here", asFlagSet(illegal));
914 }
915 }
916 else if ((sym.kind == TYP ||
917 // ISSUE: Disallowing abstract&private is no longer appropriate
918 // in the presence of inner classes. Should it be deleted here?
919 checkDisjoint(pos, flags,
920 ABSTRACT,
921 PRIVATE | STATIC))
922 &&
923 checkDisjoint(pos, flags,
924 ABSTRACT | INTERFACE,
925 FINAL | NATIVE | SYNCHRONIZED)
926 &&
927 checkDisjoint(pos, flags,
928 PUBLIC,
929 PRIVATE | PROTECTED)
930 &&
931 checkDisjoint(pos, flags,
932 PRIVATE,
933 PUBLIC | PROTECTED)
934 &&
935 checkDisjoint(pos, flags,
936 FINAL,
937 VOLATILE)
938 &&
939 (sym.kind == TYP ||
940 checkDisjoint(pos, flags,
941 ABSTRACT | NATIVE,
942 STRICTFP))) {
943 // skip
944 }
945 return flags & (mask | ~StandardFlags) | implicit;
946 }
949 /** Determine if this enum should be implicitly final.
950 *
951 * If the enum has no specialized enum contants, it is final.
952 *
953 * If the enum does have specialized enum contants, it is
954 * <i>not</i> final.
955 */
956 private long implicitEnumFinalFlag(JCTree tree) {
957 if (tree.getTag() != JCTree.CLASSDEF) return 0;
958 class SpecialTreeVisitor extends JCTree.Visitor {
959 boolean specialized;
960 SpecialTreeVisitor() {
961 this.specialized = false;
962 };
964 @Override
965 public void visitTree(JCTree tree) { /* no-op */ }
967 @Override
968 public void visitVarDef(JCVariableDecl tree) {
969 if ((tree.mods.flags & ENUM) != 0) {
970 if (tree.init instanceof JCNewClass &&
971 ((JCNewClass) tree.init).def != null) {
972 specialized = true;
973 }
974 }
975 }
976 }
978 SpecialTreeVisitor sts = new SpecialTreeVisitor();
979 JCClassDecl cdef = (JCClassDecl) tree;
980 for (JCTree defs: cdef.defs) {
981 defs.accept(sts);
982 if (sts.specialized) return 0;
983 }
984 return FINAL;
985 }
987 /* *************************************************************************
988 * Type Validation
989 **************************************************************************/
991 /** Validate a type expression. That is,
992 * check that all type arguments of a parametric type are within
993 * their bounds. This must be done in a second phase after type attributon
994 * since a class might have a subclass as type parameter bound. E.g:
995 *
996 * class B<A extends C> { ... }
997 * class C extends B<C> { ... }
998 *
999 * and we can't make sure that the bound is already attributed because
1000 * of possible cycles.
1001 *
1002 * Visitor method: Validate a type expression, if it is not null, catching
1003 * and reporting any completion failures.
1004 */
1005 void validate(JCTree tree, Env<AttrContext> env) {
1006 validate(tree, env, true);
1007 }
1008 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1009 new Validator(env).validateTree(tree, checkRaw, true);
1010 }
1012 /** Visitor method: Validate a list of type expressions.
1013 */
1014 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1015 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1016 validate(l.head, env);
1017 }
1019 /** A visitor class for type validation.
1020 */
1021 class Validator extends JCTree.Visitor {
1023 boolean isOuter;
1024 Env<AttrContext> env;
1026 Validator(Env<AttrContext> env) {
1027 this.env = env;
1028 }
1030 @Override
1031 public void visitTypeArray(JCArrayTypeTree tree) {
1032 tree.elemtype.accept(this);
1033 }
1035 @Override
1036 public void visitTypeApply(JCTypeApply tree) {
1037 if (tree.type.tag == CLASS) {
1038 List<JCExpression> args = tree.arguments;
1039 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1041 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1042 if (incompatibleArg != null) {
1043 for (JCTree arg : tree.arguments) {
1044 if (arg.type == incompatibleArg) {
1045 log.error(arg, "not.within.bounds", incompatibleArg, forms.head);
1046 }
1047 forms = forms.tail;
1048 }
1049 }
1051 forms = tree.type.tsym.type.getTypeArguments();
1053 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1055 // For matching pairs of actual argument types `a' and
1056 // formal type parameters with declared bound `b' ...
1057 while (args.nonEmpty() && forms.nonEmpty()) {
1058 validateTree(args.head,
1059 !(isOuter && is_java_lang_Class),
1060 false);
1061 args = args.tail;
1062 forms = forms.tail;
1063 }
1065 // Check that this type is either fully parameterized, or
1066 // not parameterized at all.
1067 if (tree.type.getEnclosingType().isRaw())
1068 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1069 if (tree.clazz.getTag() == JCTree.SELECT)
1070 visitSelectInternal((JCFieldAccess)tree.clazz);
1071 }
1072 }
1074 @Override
1075 public void visitTypeParameter(JCTypeParameter tree) {
1076 validateTrees(tree.bounds, true, isOuter);
1077 checkClassBounds(tree.pos(), tree.type);
1078 }
1080 @Override
1081 public void visitWildcard(JCWildcard tree) {
1082 if (tree.inner != null)
1083 validateTree(tree.inner, true, isOuter);
1084 }
1086 @Override
1087 public void visitSelect(JCFieldAccess tree) {
1088 if (tree.type.tag == CLASS) {
1089 visitSelectInternal(tree);
1091 // Check that this type is either fully parameterized, or
1092 // not parameterized at all.
1093 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1094 log.error(tree.pos(), "improperly.formed.type.param.missing");
1095 }
1096 }
1097 public void visitSelectInternal(JCFieldAccess tree) {
1098 if (tree.type.tsym.isStatic() &&
1099 tree.selected.type.isParameterized()) {
1100 // The enclosing type is not a class, so we are
1101 // looking at a static member type. However, the
1102 // qualifying expression is parameterized.
1103 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1104 } else {
1105 // otherwise validate the rest of the expression
1106 tree.selected.accept(this);
1107 }
1108 }
1110 /** Default visitor method: do nothing.
1111 */
1112 @Override
1113 public void visitTree(JCTree tree) {
1114 }
1116 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1117 try {
1118 if (tree != null) {
1119 this.isOuter = isOuter;
1120 tree.accept(this);
1121 if (checkRaw)
1122 checkRaw(tree, env);
1123 }
1124 } catch (CompletionFailure ex) {
1125 completionError(tree.pos(), ex);
1126 }
1127 }
1129 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1130 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1131 validateTree(l.head, checkRaw, isOuter);
1132 }
1134 void checkRaw(JCTree tree, Env<AttrContext> env) {
1135 if (lint.isEnabled(LintCategory.RAW) &&
1136 tree.type.tag == CLASS &&
1137 !TreeInfo.isDiamond(tree) &&
1138 !env.enclClass.name.isEmpty() && //anonymous or intersection
1139 tree.type.isRaw()) {
1140 log.warning(LintCategory.RAW,
1141 tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
1142 }
1143 }
1144 }
1146 /* *************************************************************************
1147 * Exception checking
1148 **************************************************************************/
1150 /* The following methods treat classes as sets that contain
1151 * the class itself and all their subclasses
1152 */
1154 /** Is given type a subtype of some of the types in given list?
1155 */
1156 boolean subset(Type t, List<Type> ts) {
1157 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1158 if (types.isSubtype(t, l.head)) return true;
1159 return false;
1160 }
1162 /** Is given type a subtype or supertype of
1163 * some of the types in given list?
1164 */
1165 boolean intersects(Type t, List<Type> ts) {
1166 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1167 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1168 return false;
1169 }
1171 /** Add type set to given type list, unless it is a subclass of some class
1172 * in the list.
1173 */
1174 List<Type> incl(Type t, List<Type> ts) {
1175 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1176 }
1178 /** Remove type set from type set list.
1179 */
1180 List<Type> excl(Type t, List<Type> ts) {
1181 if (ts.isEmpty()) {
1182 return ts;
1183 } else {
1184 List<Type> ts1 = excl(t, ts.tail);
1185 if (types.isSubtype(ts.head, t)) return ts1;
1186 else if (ts1 == ts.tail) return ts;
1187 else return ts1.prepend(ts.head);
1188 }
1189 }
1191 /** Form the union of two type set lists.
1192 */
1193 List<Type> union(List<Type> ts1, List<Type> ts2) {
1194 List<Type> ts = ts1;
1195 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1196 ts = incl(l.head, ts);
1197 return ts;
1198 }
1200 /** Form the difference of two type lists.
1201 */
1202 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1203 List<Type> ts = ts1;
1204 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1205 ts = excl(l.head, ts);
1206 return ts;
1207 }
1209 /** Form the intersection of two type lists.
1210 */
1211 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1212 List<Type> ts = List.nil();
1213 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1214 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1215 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1216 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1217 return ts;
1218 }
1220 /** Is exc an exception symbol that need not be declared?
1221 */
1222 boolean isUnchecked(ClassSymbol exc) {
1223 return
1224 exc.kind == ERR ||
1225 exc.isSubClass(syms.errorType.tsym, types) ||
1226 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1227 }
1229 /** Is exc an exception type that need not be declared?
1230 */
1231 boolean isUnchecked(Type exc) {
1232 return
1233 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
1234 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
1235 exc.tag == BOT;
1236 }
1238 /** Same, but handling completion failures.
1239 */
1240 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1241 try {
1242 return isUnchecked(exc);
1243 } catch (CompletionFailure ex) {
1244 completionError(pos, ex);
1245 return true;
1246 }
1247 }
1249 /** Is exc handled by given exception list?
1250 */
1251 boolean isHandled(Type exc, List<Type> handled) {
1252 return isUnchecked(exc) || subset(exc, handled);
1253 }
1255 /** Return all exceptions in thrown list that are not in handled list.
1256 * @param thrown The list of thrown exceptions.
1257 * @param handled The list of handled exceptions.
1258 */
1259 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1260 List<Type> unhandled = List.nil();
1261 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1262 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1263 return unhandled;
1264 }
1266 /* *************************************************************************
1267 * Overriding/Implementation checking
1268 **************************************************************************/
1270 /** The level of access protection given by a flag set,
1271 * where PRIVATE is highest and PUBLIC is lowest.
1272 */
1273 static int protection(long flags) {
1274 switch ((short)(flags & AccessFlags)) {
1275 case PRIVATE: return 3;
1276 case PROTECTED: return 1;
1277 default:
1278 case PUBLIC: return 0;
1279 case 0: return 2;
1280 }
1281 }
1283 /** A customized "cannot override" error message.
1284 * @param m The overriding method.
1285 * @param other The overridden method.
1286 * @return An internationalized string.
1287 */
1288 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1289 String key;
1290 if ((other.owner.flags() & INTERFACE) == 0)
1291 key = "cant.override";
1292 else if ((m.owner.flags() & INTERFACE) == 0)
1293 key = "cant.implement";
1294 else
1295 key = "clashes.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 uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1305 String key;
1306 if ((other.owner.flags() & INTERFACE) == 0)
1307 key = "unchecked.override";
1308 else if ((m.owner.flags() & INTERFACE) == 0)
1309 key = "unchecked.implement";
1310 else
1311 key = "unchecked.clash.with";
1312 return diags.fragment(key, m, m.location(), other, other.location());
1313 }
1315 /** A customized "override" warning message.
1316 * @param m The overriding method.
1317 * @param other The overridden method.
1318 * @return An internationalized string.
1319 */
1320 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1321 String key;
1322 if ((other.owner.flags() & INTERFACE) == 0)
1323 key = "varargs.override";
1324 else if ((m.owner.flags() & INTERFACE) == 0)
1325 key = "varargs.implement";
1326 else
1327 key = "varargs.clash.with";
1328 return diags.fragment(key, m, m.location(), other, other.location());
1329 }
1331 /** Check that this method conforms with overridden method 'other'.
1332 * where `origin' is the class where checking started.
1333 * Complications:
1334 * (1) Do not check overriding of synthetic methods
1335 * (reason: they might be final).
1336 * todo: check whether this is still necessary.
1337 * (2) Admit the case where an interface proxy throws fewer exceptions
1338 * than the method it implements. Augment the proxy methods with the
1339 * undeclared exceptions in this case.
1340 * (3) When generics are enabled, admit the case where an interface proxy
1341 * has a result type
1342 * extended by the result type of the method it implements.
1343 * Change the proxies result type to the smaller type in this case.
1344 *
1345 * @param tree The tree from which positions
1346 * are extracted for errors.
1347 * @param m The overriding method.
1348 * @param other The overridden method.
1349 * @param origin The class of which the overriding method
1350 * is a member.
1351 */
1352 void checkOverride(JCTree tree,
1353 MethodSymbol m,
1354 MethodSymbol other,
1355 ClassSymbol origin) {
1356 // Don't check overriding of synthetic methods or by bridge methods.
1357 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1358 return;
1359 }
1361 // Error if static method overrides instance method (JLS 8.4.6.2).
1362 if ((m.flags() & STATIC) != 0 &&
1363 (other.flags() & STATIC) == 0) {
1364 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1365 cannotOverride(m, other));
1366 return;
1367 }
1369 // Error if instance method overrides static or final
1370 // method (JLS 8.4.6.1).
1371 if ((other.flags() & FINAL) != 0 ||
1372 (m.flags() & STATIC) == 0 &&
1373 (other.flags() & STATIC) != 0) {
1374 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1375 cannotOverride(m, other),
1376 asFlagSet(other.flags() & (FINAL | STATIC)));
1377 return;
1378 }
1380 if ((m.owner.flags() & ANNOTATION) != 0) {
1381 // handled in validateAnnotationMethod
1382 return;
1383 }
1385 // Error if overriding method has weaker access (JLS 8.4.6.3).
1386 if ((origin.flags() & INTERFACE) == 0 &&
1387 protection(m.flags()) > protection(other.flags())) {
1388 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1389 cannotOverride(m, other),
1390 other.flags() == 0 ?
1391 Flag.PACKAGE :
1392 asFlagSet(other.flags() & AccessFlags));
1393 return;
1394 }
1396 Type mt = types.memberType(origin.type, m);
1397 Type ot = types.memberType(origin.type, other);
1398 // Error if overriding result type is different
1399 // (or, in the case of generics mode, not a subtype) of
1400 // overridden result type. We have to rename any type parameters
1401 // before comparing types.
1402 List<Type> mtvars = mt.getTypeArguments();
1403 List<Type> otvars = ot.getTypeArguments();
1404 Type mtres = mt.getReturnType();
1405 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1407 overrideWarner.clear();
1408 boolean resultTypesOK =
1409 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1410 if (!resultTypesOK) {
1411 if (!allowCovariantReturns &&
1412 m.owner != origin &&
1413 m.owner.isSubClass(other.owner, types)) {
1414 // allow limited interoperability with covariant returns
1415 } else {
1416 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1417 "override.incompatible.ret",
1418 cannotOverride(m, other),
1419 mtres, otres);
1420 return;
1421 }
1422 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1423 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1424 "override.unchecked.ret",
1425 uncheckedOverrides(m, other),
1426 mtres, otres);
1427 }
1429 // Error if overriding method throws an exception not reported
1430 // by overridden method.
1431 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1432 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1433 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1434 if (unhandledErased.nonEmpty()) {
1435 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1436 "override.meth.doesnt.throw",
1437 cannotOverride(m, other),
1438 unhandledUnerased.head);
1439 return;
1440 }
1441 else if (unhandledUnerased.nonEmpty()) {
1442 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1443 "override.unchecked.thrown",
1444 cannotOverride(m, other),
1445 unhandledUnerased.head);
1446 return;
1447 }
1449 // Optional warning if varargs don't agree
1450 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1451 && lint.isEnabled(LintCategory.OVERRIDES)) {
1452 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1453 ((m.flags() & Flags.VARARGS) != 0)
1454 ? "override.varargs.missing"
1455 : "override.varargs.extra",
1456 varargsOverrides(m, other));
1457 }
1459 // Warn if instance method overrides bridge method (compiler spec ??)
1460 if ((other.flags() & BRIDGE) != 0) {
1461 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1462 uncheckedOverrides(m, other));
1463 }
1465 // Warn if a deprecated method overridden by a non-deprecated one.
1466 if ((other.flags() & DEPRECATED) != 0
1467 && (m.flags() & DEPRECATED) == 0
1468 && m.outermostClass() != other.outermostClass()
1469 && !isDeprecatedOverrideIgnorable(other, origin)) {
1470 warnDeprecated(TreeInfo.diagnosticPositionFor(m, tree), other);
1471 }
1472 }
1473 // where
1474 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1475 // If the method, m, is defined in an interface, then ignore the issue if the method
1476 // is only inherited via a supertype and also implemented in the supertype,
1477 // because in that case, we will rediscover the issue when examining the method
1478 // in the supertype.
1479 // If the method, m, is not defined in an interface, then the only time we need to
1480 // address the issue is when the method is the supertype implemementation: any other
1481 // case, we will have dealt with when examining the supertype classes
1482 ClassSymbol mc = m.enclClass();
1483 Type st = types.supertype(origin.type);
1484 if (st.tag != CLASS)
1485 return true;
1486 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1488 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1489 List<Type> intfs = types.interfaces(origin.type);
1490 return (intfs.contains(mc.type) ? false : (stimpl != null));
1491 }
1492 else
1493 return (stimpl != m);
1494 }
1497 // used to check if there were any unchecked conversions
1498 Warner overrideWarner = new Warner();
1500 /** Check that a class does not inherit two concrete methods
1501 * with the same signature.
1502 * @param pos Position to be used for error reporting.
1503 * @param site The class type to be checked.
1504 */
1505 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1506 Type sup = types.supertype(site);
1507 if (sup.tag != CLASS) return;
1509 for (Type t1 = sup;
1510 t1.tsym.type.isParameterized();
1511 t1 = types.supertype(t1)) {
1512 for (Scope.Entry e1 = t1.tsym.members().elems;
1513 e1 != null;
1514 e1 = e1.sibling) {
1515 Symbol s1 = e1.sym;
1516 if (s1.kind != MTH ||
1517 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1518 !s1.isInheritedIn(site.tsym, types) ||
1519 ((MethodSymbol)s1).implementation(site.tsym,
1520 types,
1521 true) != s1)
1522 continue;
1523 Type st1 = types.memberType(t1, s1);
1524 int s1ArgsLength = st1.getParameterTypes().length();
1525 if (st1 == s1.type) continue;
1527 for (Type t2 = sup;
1528 t2.tag == CLASS;
1529 t2 = types.supertype(t2)) {
1530 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1531 e2.scope != null;
1532 e2 = e2.next()) {
1533 Symbol s2 = e2.sym;
1534 if (s2 == s1 ||
1535 s2.kind != MTH ||
1536 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1537 s2.type.getParameterTypes().length() != s1ArgsLength ||
1538 !s2.isInheritedIn(site.tsym, types) ||
1539 ((MethodSymbol)s2).implementation(site.tsym,
1540 types,
1541 true) != s2)
1542 continue;
1543 Type st2 = types.memberType(t2, s2);
1544 if (types.overrideEquivalent(st1, st2))
1545 log.error(pos, "concrete.inheritance.conflict",
1546 s1, t1, s2, t2, sup);
1547 }
1548 }
1549 }
1550 }
1551 }
1553 /** Check that classes (or interfaces) do not each define an abstract
1554 * method with same name and arguments but incompatible return types.
1555 * @param pos Position to be used for error reporting.
1556 * @param t1 The first argument type.
1557 * @param t2 The second argument type.
1558 */
1559 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1560 Type t1,
1561 Type t2) {
1562 return checkCompatibleAbstracts(pos, t1, t2,
1563 types.makeCompoundType(t1, t2));
1564 }
1566 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1567 Type t1,
1568 Type t2,
1569 Type site) {
1570 return firstIncompatibility(pos, t1, t2, site) == null;
1571 }
1573 /** Return the first method which is defined with same args
1574 * but different return types in two given interfaces, or null if none
1575 * exists.
1576 * @param t1 The first type.
1577 * @param t2 The second type.
1578 * @param site The most derived type.
1579 * @returns symbol from t2 that conflicts with one in t1.
1580 */
1581 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1582 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1583 closure(t1, interfaces1);
1584 Map<TypeSymbol,Type> interfaces2;
1585 if (t1 == t2)
1586 interfaces2 = interfaces1;
1587 else
1588 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1590 for (Type t3 : interfaces1.values()) {
1591 for (Type t4 : interfaces2.values()) {
1592 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
1593 if (s != null) return s;
1594 }
1595 }
1596 return null;
1597 }
1599 /** Compute all the supertypes of t, indexed by type symbol. */
1600 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1601 if (t.tag != CLASS) return;
1602 if (typeMap.put(t.tsym, t) == null) {
1603 closure(types.supertype(t), typeMap);
1604 for (Type i : types.interfaces(t))
1605 closure(i, typeMap);
1606 }
1607 }
1609 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1610 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1611 if (t.tag != CLASS) return;
1612 if (typesSkip.get(t.tsym) != null) return;
1613 if (typeMap.put(t.tsym, t) == null) {
1614 closure(types.supertype(t), typesSkip, typeMap);
1615 for (Type i : types.interfaces(t))
1616 closure(i, typesSkip, typeMap);
1617 }
1618 }
1620 /** Return the first method in t2 that conflicts with a method from t1. */
1621 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1622 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1623 Symbol s1 = e1.sym;
1624 Type st1 = null;
1625 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1626 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1627 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1628 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1629 Symbol s2 = e2.sym;
1630 if (s1 == s2) continue;
1631 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1632 if (st1 == null) st1 = types.memberType(t1, s1);
1633 Type st2 = types.memberType(t2, s2);
1634 if (types.overrideEquivalent(st1, st2)) {
1635 List<Type> tvars1 = st1.getTypeArguments();
1636 List<Type> tvars2 = st2.getTypeArguments();
1637 Type rt1 = st1.getReturnType();
1638 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1639 boolean compat =
1640 types.isSameType(rt1, rt2) ||
1641 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1642 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1643 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1644 checkCommonOverriderIn(s1,s2,site);
1645 if (!compat) {
1646 log.error(pos, "types.incompatible.diff.ret",
1647 t1, t2, s2.name +
1648 "(" + types.memberType(t2, s2).getParameterTypes() + ")");
1649 return s2;
1650 }
1651 } else if (!checkNameClash((ClassSymbol)site.tsym, s1, s2)) {
1652 log.error(pos,
1653 "name.clash.same.erasure.no.override",
1654 s1, s1.location(),
1655 s2, s2.location());
1656 return s2;
1657 }
1658 }
1659 }
1660 return null;
1661 }
1662 //WHERE
1663 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1664 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1665 Type st1 = types.memberType(site, s1);
1666 Type st2 = types.memberType(site, s2);
1667 closure(site, supertypes);
1668 for (Type t : supertypes.values()) {
1669 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1670 Symbol s3 = e.sym;
1671 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1672 Type st3 = types.memberType(site,s3);
1673 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1674 if (s3.owner == site.tsym) {
1675 return true;
1676 }
1677 List<Type> tvars1 = st1.getTypeArguments();
1678 List<Type> tvars2 = st2.getTypeArguments();
1679 List<Type> tvars3 = st3.getTypeArguments();
1680 Type rt1 = st1.getReturnType();
1681 Type rt2 = st2.getReturnType();
1682 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1683 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1684 boolean compat =
1685 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1686 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1687 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1688 if (compat)
1689 return true;
1690 }
1691 }
1692 }
1693 return false;
1694 }
1696 /** Check that a given method conforms with any method it overrides.
1697 * @param tree The tree from which positions are extracted
1698 * for errors.
1699 * @param m The overriding method.
1700 */
1701 void checkOverride(JCTree tree, MethodSymbol m) {
1702 ClassSymbol origin = (ClassSymbol)m.owner;
1703 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1704 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1705 log.error(tree.pos(), "enum.no.finalize");
1706 return;
1707 }
1708 for (Type t = origin.type; t.tag == CLASS;
1709 t = types.supertype(t)) {
1710 if (t != origin.type) {
1711 checkOverride(tree, t, origin, m);
1712 }
1713 for (Type t2 : types.interfaces(t)) {
1714 checkOverride(tree, t2, origin, m);
1715 }
1716 }
1717 }
1719 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
1720 TypeSymbol c = site.tsym;
1721 Scope.Entry e = c.members().lookup(m.name);
1722 while (e.scope != null) {
1723 if (m.overrides(e.sym, origin, types, false)) {
1724 if ((e.sym.flags() & ABSTRACT) == 0) {
1725 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1726 }
1727 }
1728 e = e.next();
1729 }
1730 }
1732 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
1733 if (s1.kind == MTH &&
1734 s1.isInheritedIn(origin, types) &&
1735 (s1.flags() & SYNTHETIC) == 0 &&
1736 !s2.isConstructor()) {
1737 Type er1 = s2.erasure(types);
1738 Type er2 = s1.erasure(types);
1739 if (types.isSameTypes(er1.getParameterTypes(),
1740 er2.getParameterTypes())) {
1741 return false;
1742 }
1743 }
1744 return true;
1745 }
1748 /** Check that all abstract members of given class have definitions.
1749 * @param pos Position to be used for error reporting.
1750 * @param c The class.
1751 */
1752 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1753 try {
1754 MethodSymbol undef = firstUndef(c, c);
1755 if (undef != null) {
1756 if ((c.flags() & ENUM) != 0 &&
1757 types.supertype(c.type).tsym == syms.enumSym &&
1758 (c.flags() & FINAL) == 0) {
1759 // add the ABSTRACT flag to an enum
1760 c.flags_field |= ABSTRACT;
1761 } else {
1762 MethodSymbol undef1 =
1763 new MethodSymbol(undef.flags(), undef.name,
1764 types.memberType(c.type, undef), undef.owner);
1765 log.error(pos, "does.not.override.abstract",
1766 c, undef1, undef1.location());
1767 }
1768 }
1769 } catch (CompletionFailure ex) {
1770 completionError(pos, ex);
1771 }
1772 }
1773 //where
1774 /** Return first abstract member of class `c' that is not defined
1775 * in `impl', null if there is none.
1776 */
1777 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1778 MethodSymbol undef = null;
1779 // Do not bother to search in classes that are not abstract,
1780 // since they cannot have abstract members.
1781 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1782 Scope s = c.members();
1783 for (Scope.Entry e = s.elems;
1784 undef == null && e != null;
1785 e = e.sibling) {
1786 if (e.sym.kind == MTH &&
1787 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1788 MethodSymbol absmeth = (MethodSymbol)e.sym;
1789 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1790 if (implmeth == null || implmeth == absmeth)
1791 undef = absmeth;
1792 }
1793 }
1794 if (undef == null) {
1795 Type st = types.supertype(c.type);
1796 if (st.tag == CLASS)
1797 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1798 }
1799 for (List<Type> l = types.interfaces(c.type);
1800 undef == null && l.nonEmpty();
1801 l = l.tail) {
1802 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1803 }
1804 }
1805 return undef;
1806 }
1808 void checkNonCyclicDecl(JCClassDecl tree) {
1809 CycleChecker cc = new CycleChecker();
1810 cc.scan(tree);
1811 if (!cc.errorFound && !cc.partialCheck) {
1812 tree.sym.flags_field |= ACYCLIC;
1813 }
1814 }
1816 class CycleChecker extends TreeScanner {
1818 List<Symbol> seenClasses = List.nil();
1819 boolean errorFound = false;
1820 boolean partialCheck = false;
1822 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
1823 if (sym != null && sym.kind == TYP) {
1824 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
1825 if (classEnv != null) {
1826 DiagnosticSource prevSource = log.currentSource();
1827 try {
1828 log.useSource(classEnv.toplevel.sourcefile);
1829 scan(classEnv.tree);
1830 }
1831 finally {
1832 log.useSource(prevSource.getFile());
1833 }
1834 } else if (sym.kind == TYP) {
1835 checkClass(pos, sym, List.<JCTree>nil());
1836 }
1837 } else {
1838 //not completed yet
1839 partialCheck = true;
1840 }
1841 }
1843 @Override
1844 public void visitSelect(JCFieldAccess tree) {
1845 super.visitSelect(tree);
1846 checkSymbol(tree.pos(), tree.sym);
1847 }
1849 @Override
1850 public void visitIdent(JCIdent tree) {
1851 checkSymbol(tree.pos(), tree.sym);
1852 }
1854 @Override
1855 public void visitTypeApply(JCTypeApply tree) {
1856 scan(tree.clazz);
1857 }
1859 @Override
1860 public void visitTypeArray(JCArrayTypeTree tree) {
1861 scan(tree.elemtype);
1862 }
1864 @Override
1865 public void visitClassDef(JCClassDecl tree) {
1866 List<JCTree> supertypes = List.nil();
1867 if (tree.getExtendsClause() != null) {
1868 supertypes = supertypes.prepend(tree.getExtendsClause());
1869 }
1870 if (tree.getImplementsClause() != null) {
1871 for (JCTree intf : tree.getImplementsClause()) {
1872 supertypes = supertypes.prepend(intf);
1873 }
1874 }
1875 checkClass(tree.pos(), tree.sym, supertypes);
1876 }
1878 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
1879 if ((c.flags_field & ACYCLIC) != 0)
1880 return;
1881 if (seenClasses.contains(c)) {
1882 errorFound = true;
1883 noteCyclic(pos, (ClassSymbol)c);
1884 } else if (!c.type.isErroneous()) {
1885 try {
1886 seenClasses = seenClasses.prepend(c);
1887 if (c.type.tag == CLASS) {
1888 if (supertypes.nonEmpty()) {
1889 scan(supertypes);
1890 }
1891 else {
1892 ClassType ct = (ClassType)c.type;
1893 if (ct.supertype_field == null ||
1894 ct.interfaces_field == null) {
1895 //not completed yet
1896 partialCheck = true;
1897 return;
1898 }
1899 checkSymbol(pos, ct.supertype_field.tsym);
1900 for (Type intf : ct.interfaces_field) {
1901 checkSymbol(pos, intf.tsym);
1902 }
1903 }
1904 if (c.owner.kind == TYP) {
1905 checkSymbol(pos, c.owner);
1906 }
1907 }
1908 } finally {
1909 seenClasses = seenClasses.tail;
1910 }
1911 }
1912 }
1913 }
1915 /** Check for cyclic references. Issue an error if the
1916 * symbol of the type referred to has a LOCKED flag set.
1917 *
1918 * @param pos Position to be used for error reporting.
1919 * @param t The type referred to.
1920 */
1921 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1922 checkNonCyclicInternal(pos, t);
1923 }
1926 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1927 checkNonCyclic1(pos, t, List.<TypeVar>nil());
1928 }
1930 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
1931 final TypeVar tv;
1932 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1933 return;
1934 if (seen.contains(t)) {
1935 tv = (TypeVar)t;
1936 tv.bound = types.createErrorType(t);
1937 log.error(pos, "cyclic.inheritance", t);
1938 } else if (t.tag == TYPEVAR) {
1939 tv = (TypeVar)t;
1940 seen = seen.prepend(tv);
1941 for (Type b : types.getBounds(tv))
1942 checkNonCyclic1(pos, b, seen);
1943 }
1944 }
1946 /** Check for cyclic references. Issue an error if the
1947 * symbol of the type referred to has a LOCKED flag set.
1948 *
1949 * @param pos Position to be used for error reporting.
1950 * @param t The type referred to.
1951 * @returns True if the check completed on all attributed classes
1952 */
1953 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1954 boolean complete = true; // was the check complete?
1955 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1956 Symbol c = t.tsym;
1957 if ((c.flags_field & ACYCLIC) != 0) return true;
1959 if ((c.flags_field & LOCKED) != 0) {
1960 noteCyclic(pos, (ClassSymbol)c);
1961 } else if (!c.type.isErroneous()) {
1962 try {
1963 c.flags_field |= LOCKED;
1964 if (c.type.tag == CLASS) {
1965 ClassType clazz = (ClassType)c.type;
1966 if (clazz.interfaces_field != null)
1967 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1968 complete &= checkNonCyclicInternal(pos, l.head);
1969 if (clazz.supertype_field != null) {
1970 Type st = clazz.supertype_field;
1971 if (st != null && st.tag == CLASS)
1972 complete &= checkNonCyclicInternal(pos, st);
1973 }
1974 if (c.owner.kind == TYP)
1975 complete &= checkNonCyclicInternal(pos, c.owner.type);
1976 }
1977 } finally {
1978 c.flags_field &= ~LOCKED;
1979 }
1980 }
1981 if (complete)
1982 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1983 if (complete) c.flags_field |= ACYCLIC;
1984 return complete;
1985 }
1987 /** Note that we found an inheritance cycle. */
1988 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1989 log.error(pos, "cyclic.inheritance", c);
1990 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1991 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
1992 Type st = types.supertype(c.type);
1993 if (st.tag == CLASS)
1994 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
1995 c.type = types.createErrorType(c, c.type);
1996 c.flags_field |= ACYCLIC;
1997 }
1999 /** Check that all methods which implement some
2000 * method conform to the method they implement.
2001 * @param tree The class definition whose members are checked.
2002 */
2003 void checkImplementations(JCClassDecl tree) {
2004 checkImplementations(tree, tree.sym);
2005 }
2006 //where
2007 /** Check that all methods which implement some
2008 * method in `ic' conform to the method they implement.
2009 */
2010 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
2011 ClassSymbol origin = tree.sym;
2012 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2013 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2014 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
2015 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
2016 if (e.sym.kind == MTH &&
2017 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2018 MethodSymbol absmeth = (MethodSymbol)e.sym;
2019 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2020 if (implmeth != null && implmeth != absmeth &&
2021 (implmeth.owner.flags() & INTERFACE) ==
2022 (origin.flags() & INTERFACE)) {
2023 // don't check if implmeth is in a class, yet
2024 // origin is an interface. This case arises only
2025 // if implmeth is declared in Object. The reason is
2026 // that interfaces really don't inherit from
2027 // Object it's just that the compiler represents
2028 // things that way.
2029 checkOverride(tree, implmeth, absmeth, origin);
2030 }
2031 }
2032 }
2033 }
2034 }
2035 }
2037 /** Check that all abstract methods implemented by a class are
2038 * mutually compatible.
2039 * @param pos Position to be used for error reporting.
2040 * @param c The class whose interfaces are checked.
2041 */
2042 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2043 List<Type> supertypes = types.interfaces(c);
2044 Type supertype = types.supertype(c);
2045 if (supertype.tag == CLASS &&
2046 (supertype.tsym.flags() & ABSTRACT) != 0)
2047 supertypes = supertypes.prepend(supertype);
2048 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2049 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
2050 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2051 return;
2052 for (List<Type> m = supertypes; m != l; m = m.tail)
2053 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2054 return;
2055 }
2056 checkCompatibleConcretes(pos, c);
2057 }
2059 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
2060 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
2061 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
2062 // VM allows methods and variables with differing types
2063 if (sym.kind == e.sym.kind &&
2064 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
2065 sym != e.sym &&
2066 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
2067 (sym.flags() & IPROXY) == 0 && (e.sym.flags() & IPROXY) == 0 &&
2068 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
2069 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
2070 return;
2071 }
2072 }
2073 }
2074 }
2076 /** Check that all non-override equivalent methods accessible from 'site'
2077 * are mutually compatible (JLS 8.4.8/9.4.1).
2078 *
2079 * @param pos Position to be used for error reporting.
2080 * @param site The class whose methods are checked.
2081 * @param sym The method symbol to be checked.
2082 */
2083 void checkClashes(DiagnosticPosition pos, Type site, Symbol sym) {
2084 List<Type> supertypes = types.closure(site);
2085 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2086 for (List<Type> m = supertypes; m.nonEmpty(); m = m.tail) {
2087 checkClashes(pos, l.head, m.head, site, sym);
2088 }
2089 }
2090 }
2092 /** Reports an error whenever 'sym' seen as a member of type 't1' clashes with
2093 * some unrelated method defined in 't2'.
2094 */
2095 private void checkClashes(DiagnosticPosition pos, Type t1, Type t2, Type site, Symbol s1) {
2096 ClashFilter cf = new ClashFilter(site);
2097 s1 = ((MethodSymbol)s1).implementedIn(t1.tsym, types);
2098 if (s1 == null) return;
2099 Type st1 = types.memberType(site, s1);
2100 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name, cf); e2.scope != null; e2 = e2.next(cf)) {
2101 Symbol s2 = e2.sym;
2102 if (s1 == s2) continue;
2103 Type st2 = types.memberType(site, s2);
2104 if (!types.overrideEquivalent(st1, st2) &&
2105 !checkNameClash((ClassSymbol)site.tsym, s1, s2)) {
2106 log.error(pos,
2107 "name.clash.same.erasure.no.override",
2108 s1, s1.location(),
2109 s2, s2.location());
2110 }
2111 }
2112 }
2113 //where
2114 private class ClashFilter implements Filter<Symbol> {
2116 Type site;
2118 ClashFilter(Type site) {
2119 this.site = site;
2120 }
2122 public boolean accepts(Symbol s) {
2123 return s.kind == MTH &&
2124 (s.flags() & SYNTHETIC) == 0 &&
2125 s.isInheritedIn(site.tsym, types) &&
2126 !s.isConstructor();
2127 }
2128 }
2130 /** Report a conflict between a user symbol and a synthetic symbol.
2131 */
2132 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
2133 if (!sym.type.isErroneous()) {
2134 if (warnOnSyntheticConflicts) {
2135 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
2136 }
2137 else {
2138 log.error(pos, "synthetic.name.conflict", sym, sym.location());
2139 }
2140 }
2141 }
2143 /** Check that class c does not implement directly or indirectly
2144 * the same parameterized interface with two different argument lists.
2145 * @param pos Position to be used for error reporting.
2146 * @param type The type whose interfaces are checked.
2147 */
2148 void checkClassBounds(DiagnosticPosition pos, Type type) {
2149 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
2150 }
2151 //where
2152 /** Enter all interfaces of type `type' into the hash table `seensofar'
2153 * with their class symbol as key and their type as value. Make
2154 * sure no class is entered with two different types.
2155 */
2156 void checkClassBounds(DiagnosticPosition pos,
2157 Map<TypeSymbol,Type> seensofar,
2158 Type type) {
2159 if (type.isErroneous()) return;
2160 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
2161 Type it = l.head;
2162 Type oldit = seensofar.put(it.tsym, it);
2163 if (oldit != null) {
2164 List<Type> oldparams = oldit.allparams();
2165 List<Type> newparams = it.allparams();
2166 if (!types.containsTypeEquivalent(oldparams, newparams))
2167 log.error(pos, "cant.inherit.diff.arg",
2168 it.tsym, Type.toString(oldparams),
2169 Type.toString(newparams));
2170 }
2171 checkClassBounds(pos, seensofar, it);
2172 }
2173 Type st = types.supertype(type);
2174 if (st != null) checkClassBounds(pos, seensofar, st);
2175 }
2177 /** Enter interface into into set.
2178 * If it existed already, issue a "repeated interface" error.
2179 */
2180 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
2181 if (its.contains(it))
2182 log.error(pos, "repeated.interface");
2183 else {
2184 its.add(it);
2185 }
2186 }
2188 /* *************************************************************************
2189 * Check annotations
2190 **************************************************************************/
2192 /**
2193 * Recursively validate annotations values
2194 */
2195 void validateAnnotationTree(JCTree tree) {
2196 class AnnotationValidator extends TreeScanner {
2197 @Override
2198 public void visitAnnotation(JCAnnotation tree) {
2199 super.visitAnnotation(tree);
2200 validateAnnotation(tree);
2201 }
2202 }
2203 tree.accept(new AnnotationValidator());
2204 }
2206 /** Annotation types are restricted to primitives, String, an
2207 * enum, an annotation, Class, Class<?>, Class<? extends
2208 * Anything>, arrays of the preceding.
2209 */
2210 void validateAnnotationType(JCTree restype) {
2211 // restype may be null if an error occurred, so don't bother validating it
2212 if (restype != null) {
2213 validateAnnotationType(restype.pos(), restype.type);
2214 }
2215 }
2217 void validateAnnotationType(DiagnosticPosition pos, Type type) {
2218 if (type.isPrimitive()) return;
2219 if (types.isSameType(type, syms.stringType)) return;
2220 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
2221 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
2222 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
2223 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
2224 validateAnnotationType(pos, types.elemtype(type));
2225 return;
2226 }
2227 log.error(pos, "invalid.annotation.member.type");
2228 }
2230 /**
2231 * "It is also a compile-time error if any method declared in an
2232 * annotation type has a signature that is override-equivalent to
2233 * that of any public or protected method declared in class Object
2234 * or in the interface annotation.Annotation."
2235 *
2236 * @jls3 9.6 Annotation Types
2237 */
2238 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
2239 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
2240 Scope s = sup.tsym.members();
2241 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
2242 if (e.sym.kind == MTH &&
2243 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
2244 types.overrideEquivalent(m.type, e.sym.type))
2245 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
2246 }
2247 }
2248 }
2250 /** Check the annotations of a symbol.
2251 */
2252 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
2253 if (skipAnnotations) return;
2254 for (JCAnnotation a : annotations)
2255 validateAnnotation(a, s);
2256 }
2258 /** Check an annotation of a symbol.
2259 */
2260 public void validateAnnotation(JCAnnotation a, Symbol s) {
2261 validateAnnotationTree(a);
2263 if (!annotationApplicable(a, s))
2264 log.error(a.pos(), "annotation.type.not.applicable");
2266 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2267 if (!isOverrider(s))
2268 log.error(a.pos(), "method.does.not.override.superclass");
2269 }
2270 }
2272 /** Is s a method symbol that overrides a method in a superclass? */
2273 boolean isOverrider(Symbol s) {
2274 if (s.kind != MTH || s.isStatic())
2275 return false;
2276 MethodSymbol m = (MethodSymbol)s;
2277 TypeSymbol owner = (TypeSymbol)m.owner;
2278 for (Type sup : types.closure(owner.type)) {
2279 if (sup == owner.type)
2280 continue; // skip "this"
2281 Scope scope = sup.tsym.members();
2282 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
2283 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
2284 return true;
2285 }
2286 }
2287 return false;
2288 }
2290 /** Is the annotation applicable to the symbol? */
2291 boolean annotationApplicable(JCAnnotation a, Symbol s) {
2292 Attribute.Compound atTarget =
2293 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2294 if (atTarget == null) return true;
2295 Attribute atValue = atTarget.member(names.value);
2296 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2297 Attribute.Array arr = (Attribute.Array) atValue;
2298 for (Attribute app : arr.values) {
2299 if (!(app instanceof Attribute.Enum)) return true; // recovery
2300 Attribute.Enum e = (Attribute.Enum) app;
2301 if (e.value.name == names.TYPE)
2302 { if (s.kind == TYP) return true; }
2303 else if (e.value.name == names.FIELD)
2304 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
2305 else if (e.value.name == names.METHOD)
2306 { if (s.kind == MTH && !s.isConstructor()) return true; }
2307 else if (e.value.name == names.PARAMETER)
2308 { if (s.kind == VAR &&
2309 s.owner.kind == MTH &&
2310 (s.flags() & PARAMETER) != 0)
2311 return true;
2312 }
2313 else if (e.value.name == names.CONSTRUCTOR)
2314 { if (s.kind == MTH && s.isConstructor()) return true; }
2315 else if (e.value.name == names.LOCAL_VARIABLE)
2316 { if (s.kind == VAR && s.owner.kind == MTH &&
2317 (s.flags() & PARAMETER) == 0)
2318 return true;
2319 }
2320 else if (e.value.name == names.ANNOTATION_TYPE)
2321 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
2322 return true;
2323 }
2324 else if (e.value.name == names.PACKAGE)
2325 { if (s.kind == PCK) return true; }
2326 else if (e.value.name == names.TYPE_USE)
2327 { if (s.kind == TYP ||
2328 s.kind == VAR ||
2329 (s.kind == MTH && !s.isConstructor() &&
2330 s.type.getReturnType().tag != VOID))
2331 return true;
2332 }
2333 else
2334 return true; // recovery
2335 }
2336 return false;
2337 }
2339 /** Check an annotation value.
2340 */
2341 public void validateAnnotation(JCAnnotation a) {
2342 if (a.type.isErroneous()) return;
2344 // collect an inventory of the members (sorted alphabetically)
2345 Set<MethodSymbol> members = new TreeSet<MethodSymbol>(new Comparator<Symbol>() {
2346 public int compare(Symbol t, Symbol t1) {
2347 return t.name.compareTo(t1.name);
2348 }
2349 });
2350 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
2351 e != null;
2352 e = e.sibling)
2353 if (e.sym.kind == MTH)
2354 members.add((MethodSymbol) e.sym);
2356 // count them off as they're annotated
2357 for (JCTree arg : a.args) {
2358 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
2359 JCAssign assign = (JCAssign) arg;
2360 Symbol m = TreeInfo.symbol(assign.lhs);
2361 if (m == null || m.type.isErroneous()) continue;
2362 if (!members.remove(m))
2363 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
2364 m.name, a.type);
2365 }
2367 // all the remaining ones better have default values
2368 ListBuffer<Name> missingDefaults = ListBuffer.lb();
2369 for (MethodSymbol m : members) {
2370 if (m.defaultValue == null && !m.type.isErroneous()) {
2371 missingDefaults.append(m.name);
2372 }
2373 }
2374 if (missingDefaults.nonEmpty()) {
2375 String key = (missingDefaults.size() > 1)
2376 ? "annotation.missing.default.value.1"
2377 : "annotation.missing.default.value";
2378 log.error(a.pos(), key, a.type, missingDefaults);
2379 }
2381 // special case: java.lang.annotation.Target must not have
2382 // repeated values in its value member
2383 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
2384 a.args.tail == null)
2385 return;
2387 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
2388 JCAssign assign = (JCAssign) a.args.head;
2389 Symbol m = TreeInfo.symbol(assign.lhs);
2390 if (m.name != names.value) return;
2391 JCTree rhs = assign.rhs;
2392 if (rhs.getTag() != JCTree.NEWARRAY) return;
2393 JCNewArray na = (JCNewArray) rhs;
2394 Set<Symbol> targets = new HashSet<Symbol>();
2395 for (JCTree elem : na.elems) {
2396 if (!targets.add(TreeInfo.symbol(elem))) {
2397 log.error(elem.pos(), "repeated.annotation.target");
2398 }
2399 }
2400 }
2402 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
2403 if (allowAnnotations &&
2404 lint.isEnabled(LintCategory.DEP_ANN) &&
2405 (s.flags() & DEPRECATED) != 0 &&
2406 !syms.deprecatedType.isErroneous() &&
2407 s.attribute(syms.deprecatedType.tsym) == null) {
2408 log.warning(LintCategory.DEP_ANN,
2409 pos, "missing.deprecated.annotation");
2410 }
2411 }
2413 /* *************************************************************************
2414 * Check for recursive annotation elements.
2415 **************************************************************************/
2417 /** Check for cycles in the graph of annotation elements.
2418 */
2419 void checkNonCyclicElements(JCClassDecl tree) {
2420 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
2421 Assert.check((tree.sym.flags_field & LOCKED) == 0);
2422 try {
2423 tree.sym.flags_field |= LOCKED;
2424 for (JCTree def : tree.defs) {
2425 if (def.getTag() != JCTree.METHODDEF) continue;
2426 JCMethodDecl meth = (JCMethodDecl)def;
2427 checkAnnotationResType(meth.pos(), meth.restype.type);
2428 }
2429 } finally {
2430 tree.sym.flags_field &= ~LOCKED;
2431 tree.sym.flags_field |= ACYCLIC_ANN;
2432 }
2433 }
2435 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
2436 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
2437 return;
2438 if ((tsym.flags_field & LOCKED) != 0) {
2439 log.error(pos, "cyclic.annotation.element");
2440 return;
2441 }
2442 try {
2443 tsym.flags_field |= LOCKED;
2444 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
2445 Symbol s = e.sym;
2446 if (s.kind != Kinds.MTH)
2447 continue;
2448 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
2449 }
2450 } finally {
2451 tsym.flags_field &= ~LOCKED;
2452 tsym.flags_field |= ACYCLIC_ANN;
2453 }
2454 }
2456 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
2457 switch (type.tag) {
2458 case TypeTags.CLASS:
2459 if ((type.tsym.flags() & ANNOTATION) != 0)
2460 checkNonCyclicElementsInternal(pos, type.tsym);
2461 break;
2462 case TypeTags.ARRAY:
2463 checkAnnotationResType(pos, types.elemtype(type));
2464 break;
2465 default:
2466 break; // int etc
2467 }
2468 }
2470 /* *************************************************************************
2471 * Check for cycles in the constructor call graph.
2472 **************************************************************************/
2474 /** Check for cycles in the graph of constructors calling other
2475 * constructors.
2476 */
2477 void checkCyclicConstructors(JCClassDecl tree) {
2478 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
2480 // enter each constructor this-call into the map
2481 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2482 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
2483 if (app == null) continue;
2484 JCMethodDecl meth = (JCMethodDecl) l.head;
2485 if (TreeInfo.name(app.meth) == names._this) {
2486 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
2487 } else {
2488 meth.sym.flags_field |= ACYCLIC;
2489 }
2490 }
2492 // Check for cycles in the map
2493 Symbol[] ctors = new Symbol[0];
2494 ctors = callMap.keySet().toArray(ctors);
2495 for (Symbol caller : ctors) {
2496 checkCyclicConstructor(tree, caller, callMap);
2497 }
2498 }
2500 /** Look in the map to see if the given constructor is part of a
2501 * call cycle.
2502 */
2503 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2504 Map<Symbol,Symbol> callMap) {
2505 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2506 if ((ctor.flags_field & LOCKED) != 0) {
2507 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2508 "recursive.ctor.invocation");
2509 } else {
2510 ctor.flags_field |= LOCKED;
2511 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2512 ctor.flags_field &= ~LOCKED;
2513 }
2514 ctor.flags_field |= ACYCLIC;
2515 }
2516 }
2518 /* *************************************************************************
2519 * Miscellaneous
2520 **************************************************************************/
2522 /**
2523 * Return the opcode of the operator but emit an error if it is an
2524 * error.
2525 * @param pos position for error reporting.
2526 * @param operator an operator
2527 * @param tag a tree tag
2528 * @param left type of left hand side
2529 * @param right type of right hand side
2530 */
2531 int checkOperator(DiagnosticPosition pos,
2532 OperatorSymbol operator,
2533 int tag,
2534 Type left,
2535 Type right) {
2536 if (operator.opcode == ByteCodes.error) {
2537 log.error(pos,
2538 "operator.cant.be.applied",
2539 treeinfo.operatorName(tag),
2540 List.of(left, right));
2541 }
2542 return operator.opcode;
2543 }
2546 /**
2547 * Check for division by integer constant zero
2548 * @param pos Position for error reporting.
2549 * @param operator The operator for the expression
2550 * @param operand The right hand operand for the expression
2551 */
2552 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2553 if (operand.constValue() != null
2554 && lint.isEnabled(LintCategory.DIVZERO)
2555 && operand.tag <= LONG
2556 && ((Number) (operand.constValue())).longValue() == 0) {
2557 int opc = ((OperatorSymbol)operator).opcode;
2558 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2559 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2560 log.warning(LintCategory.DIVZERO, pos, "div.zero");
2561 }
2562 }
2563 }
2565 /**
2566 * Check for empty statements after if
2567 */
2568 void checkEmptyIf(JCIf tree) {
2569 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(LintCategory.EMPTY))
2570 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), "empty.if");
2571 }
2573 /** Check that symbol is unique in given scope.
2574 * @param pos Position for error reporting.
2575 * @param sym The symbol.
2576 * @param s The scope.
2577 */
2578 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2579 if (sym.type.isErroneous())
2580 return true;
2581 if (sym.owner.name == names.any) return false;
2582 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2583 if (sym != e.sym &&
2584 sym.kind == e.sym.kind &&
2585 sym.name != names.error &&
2586 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
2587 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS))
2588 varargsDuplicateError(pos, sym, e.sym);
2589 else if (sym.kind == MTH && !types.overrideEquivalent(sym.type, e.sym.type))
2590 duplicateErasureError(pos, sym, e.sym);
2591 else
2592 duplicateError(pos, e.sym);
2593 return false;
2594 }
2595 }
2596 return true;
2597 }
2598 //where
2599 /** Report duplicate declaration error.
2600 */
2601 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
2602 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
2603 log.error(pos, "name.clash.same.erasure", sym1, sym2);
2604 }
2605 }
2607 /** Check that single-type import is not already imported or top-level defined,
2608 * but make an exception for two single-type imports which denote the same type.
2609 * @param pos Position for error reporting.
2610 * @param sym The symbol.
2611 * @param s The scope
2612 */
2613 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2614 return checkUniqueImport(pos, sym, s, false);
2615 }
2617 /** Check that static single-type import is not already imported or top-level defined,
2618 * but make an exception for two single-type imports which denote the same type.
2619 * @param pos Position for error reporting.
2620 * @param sym The symbol.
2621 * @param s The scope
2622 * @param staticImport Whether or not this was a static import
2623 */
2624 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2625 return checkUniqueImport(pos, sym, s, true);
2626 }
2628 /** Check that single-type import is not already imported or top-level defined,
2629 * but make an exception for two single-type imports which denote the same type.
2630 * @param pos Position for error reporting.
2631 * @param sym The symbol.
2632 * @param s The scope.
2633 * @param staticImport Whether or not this was a static import
2634 */
2635 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2636 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2637 // is encountered class entered via a class declaration?
2638 boolean isClassDecl = e.scope == s;
2639 if ((isClassDecl || sym != e.sym) &&
2640 sym.kind == e.sym.kind &&
2641 sym.name != names.error) {
2642 if (!e.sym.type.isErroneous()) {
2643 String what = e.sym.toString();
2644 if (!isClassDecl) {
2645 if (staticImport)
2646 log.error(pos, "already.defined.static.single.import", what);
2647 else
2648 log.error(pos, "already.defined.single.import", what);
2649 }
2650 else if (sym != e.sym)
2651 log.error(pos, "already.defined.this.unit", what);
2652 }
2653 return false;
2654 }
2655 }
2656 return true;
2657 }
2659 /** Check that a qualified name is in canonical form (for import decls).
2660 */
2661 public void checkCanonical(JCTree tree) {
2662 if (!isCanonical(tree))
2663 log.error(tree.pos(), "import.requires.canonical",
2664 TreeInfo.symbol(tree));
2665 }
2666 // where
2667 private boolean isCanonical(JCTree tree) {
2668 while (tree.getTag() == JCTree.SELECT) {
2669 JCFieldAccess s = (JCFieldAccess) tree;
2670 if (s.sym.owner != TreeInfo.symbol(s.selected))
2671 return false;
2672 tree = s.selected;
2673 }
2674 return true;
2675 }
2677 private class ConversionWarner extends Warner {
2678 final String uncheckedKey;
2679 final Type found;
2680 final Type expected;
2681 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
2682 super(pos);
2683 this.uncheckedKey = uncheckedKey;
2684 this.found = found;
2685 this.expected = expected;
2686 }
2688 @Override
2689 public void warn(LintCategory lint) {
2690 boolean warned = this.warned;
2691 super.warn(lint);
2692 if (warned) return; // suppress redundant diagnostics
2693 switch (lint) {
2694 case UNCHECKED:
2695 Check.this.warnUnchecked(pos(), "prob.found.req", diags.fragment(uncheckedKey), found, expected);
2696 break;
2697 case VARARGS:
2698 if (method != null &&
2699 method.attribute(syms.trustMeType.tsym) != null &&
2700 isTrustMeAllowedOnMethod(method) &&
2701 !types.isReifiable(method.type.getParameterTypes().last())) {
2702 Check.this.warnUnsafeVararg(pos(), "varargs.unsafe.use.varargs.param", method.params.last());
2703 }
2704 break;
2705 default:
2706 throw new AssertionError("Unexpected lint: " + lint);
2707 }
2708 }
2709 }
2711 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2712 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2713 }
2715 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2716 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2717 }
2718 }
