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src/share/classes/com/sun/tools/javac/comp/Check.java@899f7c3d9426
src/share/classes/com/sun/tools/javac/comp/Check.java
Thu, 03 Feb 2011 09:35:21 +0000
- author
- mcimadamore
- date
- Thu, 03 Feb 2011 09:35:21 +0000
- changeset 852
- 899f7c3d9426
- parent 845
- 5a43b245aed1
- child 853
- 875262e89b52
- permissions
- -rw-r--r--
6594914: @SuppressWarnings("deprecation") does not not work for the type of a variable
Summary: Lint warnings generated during MemberEnter might ignore @SuppressWarnings annotations
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 boolean enableSunApiLintControl;
72 private final TreeInfo treeinfo;
74 // The set of lint options currently in effect. It is initialized
75 // from the context, and then is set/reset as needed by Attr as it
76 // visits all the various parts of the trees during attribution.
77 private Lint lint;
79 // The method being analyzed in Attr - it is set/reset as needed by
80 // Attr as it visits new method declarations.
81 private MethodSymbol method;
83 public static Check instance(Context context) {
84 Check instance = context.get(checkKey);
85 if (instance == null)
86 instance = new Check(context);
87 return instance;
88 }
90 protected Check(Context context) {
91 context.put(checkKey, this);
93 names = Names.instance(context);
94 log = Log.instance(context);
95 syms = Symtab.instance(context);
96 enter = Enter.instance(context);
97 infer = Infer.instance(context);
98 this.types = Types.instance(context);
99 diags = JCDiagnostic.Factory.instance(context);
100 Options options = Options.instance(context);
101 lint = Lint.instance(context);
102 treeinfo = TreeInfo.instance(context);
104 Source source = Source.instance(context);
105 allowGenerics = source.allowGenerics();
106 allowAnnotations = source.allowAnnotations();
107 allowCovariantReturns = source.allowCovariantReturns();
108 allowSimplifiedVarargs = source.allowSimplifiedVarargs();
109 complexInference = options.isSet(COMPLEXINFERENCE);
110 skipAnnotations = options.isSet("skipAnnotations");
111 warnOnSyntheticConflicts = options.isSet("warnOnSyntheticConflicts");
112 suppressAbortOnBadClassFile = options.isSet("suppressAbortOnBadClassFile");
113 enableSunApiLintControl = options.isSet("enableSunApiLintControl");
115 Target target = Target.instance(context);
116 syntheticNameChar = target.syntheticNameChar();
118 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION);
119 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED);
120 boolean verboseSunApi = lint.isEnabled(LintCategory.SUNAPI);
121 boolean enforceMandatoryWarnings = source.enforceMandatoryWarnings();
123 deprecationHandler = new MandatoryWarningHandler(log, verboseDeprecated,
124 enforceMandatoryWarnings, "deprecated", LintCategory.DEPRECATION);
125 uncheckedHandler = new MandatoryWarningHandler(log, verboseUnchecked,
126 enforceMandatoryWarnings, "unchecked", LintCategory.UNCHECKED);
127 sunApiHandler = new MandatoryWarningHandler(log, verboseSunApi,
128 enforceMandatoryWarnings, "sunapi", null);
130 deferredLintHandler = DeferredLintHandler.immediateHandler;
131 }
133 /** Switch: generics enabled?
134 */
135 boolean allowGenerics;
137 /** Switch: annotations enabled?
138 */
139 boolean allowAnnotations;
141 /** Switch: covariant returns enabled?
142 */
143 boolean allowCovariantReturns;
145 /** Switch: simplified varargs enabled?
146 */
147 boolean allowSimplifiedVarargs;
149 /** Switch: -complexinference option set?
150 */
151 boolean complexInference;
153 /** Character for synthetic names
154 */
155 char syntheticNameChar;
157 /** A table mapping flat names of all compiled classes in this run to their
158 * symbols; maintained from outside.
159 */
160 public Map<Name,ClassSymbol> compiled = new HashMap<Name, ClassSymbol>();
162 /** A handler for messages about deprecated usage.
163 */
164 private MandatoryWarningHandler deprecationHandler;
166 /** A handler for messages about unchecked or unsafe usage.
167 */
168 private MandatoryWarningHandler uncheckedHandler;
170 /** A handler for messages about using proprietary API.
171 */
172 private MandatoryWarningHandler sunApiHandler;
174 /** A handler for deferred lint warnings.
175 */
176 private DeferredLintHandler deferredLintHandler;
178 /* *************************************************************************
179 * Errors and Warnings
180 **************************************************************************/
182 Lint setLint(Lint newLint) {
183 Lint prev = lint;
184 lint = newLint;
185 return prev;
186 }
188 DeferredLintHandler setDeferredLintHandler(DeferredLintHandler newDeferredLintHandler) {
189 DeferredLintHandler prev = deferredLintHandler;
190 deferredLintHandler = newDeferredLintHandler;
191 return prev;
192 }
194 MethodSymbol setMethod(MethodSymbol newMethod) {
195 MethodSymbol prev = method;
196 method = newMethod;
197 return prev;
198 }
200 /** Warn about deprecated symbol.
201 * @param pos Position to be used for error reporting.
202 * @param sym The deprecated symbol.
203 */
204 void warnDeprecated(DiagnosticPosition pos, Symbol sym) {
205 if (!lint.isSuppressed(LintCategory.DEPRECATION))
206 deprecationHandler.report(pos, "has.been.deprecated", sym, sym.location());
207 }
209 /** Warn about unchecked operation.
210 * @param pos Position to be used for error reporting.
211 * @param msg A string describing the problem.
212 */
213 public void warnUnchecked(DiagnosticPosition pos, String msg, Object... args) {
214 if (!lint.isSuppressed(LintCategory.UNCHECKED))
215 uncheckedHandler.report(pos, msg, args);
216 }
218 /** Warn about unsafe vararg method decl.
219 * @param pos Position to be used for error reporting.
220 * @param sym The deprecated symbol.
221 */
222 void warnUnsafeVararg(DiagnosticPosition pos, String key, Object... args) {
223 if (lint.isEnabled(LintCategory.VARARGS) && allowSimplifiedVarargs)
224 log.warning(LintCategory.VARARGS, pos, key, args);
225 }
227 /** Warn about using proprietary API.
228 * @param pos Position to be used for error reporting.
229 * @param msg A string describing the problem.
230 */
231 public void warnSunApi(DiagnosticPosition pos, String msg, Object... args) {
232 if (!lint.isSuppressed(LintCategory.SUNAPI))
233 sunApiHandler.report(pos, msg, args);
234 }
236 public void warnStatic(DiagnosticPosition pos, String msg, Object... args) {
237 if (lint.isEnabled(LintCategory.STATIC))
238 log.warning(LintCategory.STATIC, pos, msg, args);
239 }
241 /**
242 * Report any deferred diagnostics.
243 */
244 public void reportDeferredDiagnostics() {
245 deprecationHandler.reportDeferredDiagnostic();
246 uncheckedHandler.reportDeferredDiagnostic();
247 sunApiHandler.reportDeferredDiagnostic();
248 }
251 /** Report a failure to complete a class.
252 * @param pos Position to be used for error reporting.
253 * @param ex The failure to report.
254 */
255 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) {
256 log.error(pos, "cant.access", ex.sym, ex.getDetailValue());
257 if (ex instanceof ClassReader.BadClassFile
258 && !suppressAbortOnBadClassFile) throw new Abort();
259 else return syms.errType;
260 }
262 /** Report a type error.
263 * @param pos Position to be used for error reporting.
264 * @param problem A string describing the error.
265 * @param found The type that was found.
266 * @param req The type that was required.
267 */
268 Type typeError(DiagnosticPosition pos, Object problem, Type found, Type req) {
269 log.error(pos, "prob.found.req",
270 problem, found, req);
271 return types.createErrorType(found);
272 }
274 Type typeError(DiagnosticPosition pos, String problem, Type found, Type req, Object explanation) {
275 log.error(pos, "prob.found.req.1", problem, found, req, explanation);
276 return types.createErrorType(found);
277 }
279 /** Report an error that wrong type tag was found.
280 * @param pos Position to be used for error reporting.
281 * @param required An internationalized string describing the type tag
282 * required.
283 * @param found The type that was found.
284 */
285 Type typeTagError(DiagnosticPosition pos, Object required, Object found) {
286 // this error used to be raised by the parser,
287 // but has been delayed to this point:
288 if (found instanceof Type && ((Type)found).tag == VOID) {
289 log.error(pos, "illegal.start.of.type");
290 return syms.errType;
291 }
292 log.error(pos, "type.found.req", found, required);
293 return types.createErrorType(found instanceof Type ? (Type)found : syms.errType);
294 }
296 /** Report an error that symbol cannot be referenced before super
297 * has been called.
298 * @param pos Position to be used for error reporting.
299 * @param sym The referenced symbol.
300 */
301 void earlyRefError(DiagnosticPosition pos, Symbol sym) {
302 log.error(pos, "cant.ref.before.ctor.called", sym);
303 }
305 /** Report duplicate declaration error.
306 */
307 void duplicateError(DiagnosticPosition pos, Symbol sym) {
308 if (!sym.type.isErroneous()) {
309 log.error(pos, "already.defined", sym, sym.location());
310 }
311 }
313 /** Report array/varargs duplicate declaration
314 */
315 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
316 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
317 log.error(pos, "array.and.varargs", sym1, sym2, sym2.location());
318 }
319 }
321 /* ************************************************************************
322 * duplicate declaration checking
323 *************************************************************************/
325 /** Check that variable does not hide variable with same name in
326 * immediately enclosing local scope.
327 * @param pos Position for error reporting.
328 * @param v The symbol.
329 * @param s The scope.
330 */
331 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) {
332 if (s.next != null) {
333 for (Scope.Entry e = s.next.lookup(v.name);
334 e.scope != null && e.sym.owner == v.owner;
335 e = e.next()) {
336 if (e.sym.kind == VAR &&
337 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
338 v.name != names.error) {
339 duplicateError(pos, e.sym);
340 return;
341 }
342 }
343 }
344 }
346 /** Check that a class or interface does not hide a class or
347 * interface with same name in immediately enclosing local scope.
348 * @param pos Position for error reporting.
349 * @param c The symbol.
350 * @param s The scope.
351 */
352 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) {
353 if (s.next != null) {
354 for (Scope.Entry e = s.next.lookup(c.name);
355 e.scope != null && e.sym.owner == c.owner;
356 e = e.next()) {
357 if (e.sym.kind == TYP && e.sym.type.tag != TYPEVAR &&
358 (e.sym.owner.kind & (VAR | MTH)) != 0 &&
359 c.name != names.error) {
360 duplicateError(pos, e.sym);
361 return;
362 }
363 }
364 }
365 }
367 /** Check that class does not have the same name as one of
368 * its enclosing classes, or as a class defined in its enclosing scope.
369 * return true if class is unique in its enclosing scope.
370 * @param pos Position for error reporting.
371 * @param name The class name.
372 * @param s The enclosing scope.
373 */
374 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) {
375 for (Scope.Entry e = s.lookup(name); e.scope == s; e = e.next()) {
376 if (e.sym.kind == TYP && e.sym.name != names.error) {
377 duplicateError(pos, e.sym);
378 return false;
379 }
380 }
381 for (Symbol sym = s.owner; sym != null; sym = sym.owner) {
382 if (sym.kind == TYP && sym.name == name && sym.name != names.error) {
383 duplicateError(pos, sym);
384 return true;
385 }
386 }
387 return true;
388 }
390 /* *************************************************************************
391 * Class name generation
392 **************************************************************************/
394 /** Return name of local class.
395 * This is of the form <enclClass> $ n <classname>
396 * where
397 * enclClass is the flat name of the enclosing class,
398 * classname is the simple name of the local class
399 */
400 Name localClassName(ClassSymbol c) {
401 for (int i=1; ; i++) {
402 Name flatname = names.
403 fromString("" + c.owner.enclClass().flatname +
404 syntheticNameChar + i +
405 c.name);
406 if (compiled.get(flatname) == null) return flatname;
407 }
408 }
410 /* *************************************************************************
411 * Type Checking
412 **************************************************************************/
414 /** Check that a given type is assignable to a given proto-type.
415 * If it is, return the type, otherwise return errType.
416 * @param pos Position to be used for error reporting.
417 * @param found The type that was found.
418 * @param req The type that was required.
419 */
420 Type checkType(DiagnosticPosition pos, Type found, Type req) {
421 return checkType(pos, found, req, "incompatible.types");
422 }
424 Type checkType(DiagnosticPosition pos, Type found, Type req, String errKey) {
425 if (req.tag == ERROR)
426 return req;
427 if (found.tag == FORALL)
428 return instantiatePoly(pos, (ForAll)found, req, convertWarner(pos, found, req));
429 if (req.tag == NONE)
430 return found;
431 if (types.isAssignable(found, req, convertWarner(pos, found, req)))
432 return found;
433 if (found.tag <= DOUBLE && req.tag <= DOUBLE)
434 return typeError(pos, diags.fragment("possible.loss.of.precision"), found, req);
435 if (found.isSuperBound()) {
436 log.error(pos, "assignment.from.super-bound", found);
437 return types.createErrorType(found);
438 }
439 if (req.isExtendsBound()) {
440 log.error(pos, "assignment.to.extends-bound", req);
441 return types.createErrorType(found);
442 }
443 return typeError(pos, diags.fragment(errKey), found, req);
444 }
446 /** Instantiate polymorphic type to some prototype, unless
447 * prototype is `anyPoly' in which case polymorphic type
448 * is returned unchanged.
449 */
450 Type instantiatePoly(DiagnosticPosition pos, ForAll t, Type pt, Warner warn) throws Infer.NoInstanceException {
451 if (pt == Infer.anyPoly && complexInference) {
452 return t;
453 } else if (pt == Infer.anyPoly || pt.tag == NONE) {
454 Type newpt = t.qtype.tag <= VOID ? t.qtype : syms.objectType;
455 return instantiatePoly(pos, t, newpt, warn);
456 } else if (pt.tag == ERROR) {
457 return pt;
458 } else {
459 try {
460 return infer.instantiateExpr(t, pt, warn);
461 } catch (Infer.NoInstanceException ex) {
462 if (ex.isAmbiguous) {
463 JCDiagnostic d = ex.getDiagnostic();
464 log.error(pos,
465 "undetermined.type" + (d!=null ? ".1" : ""),
466 t, d);
467 return types.createErrorType(pt);
468 } else {
469 JCDiagnostic d = ex.getDiagnostic();
470 return typeError(pos,
471 diags.fragment("incompatible.types" + (d!=null ? ".1" : ""), d),
472 t, pt);
473 }
474 } catch (Infer.InvalidInstanceException ex) {
475 JCDiagnostic d = ex.getDiagnostic();
476 log.error(pos, "invalid.inferred.types", t.tvars, d);
477 return types.createErrorType(pt);
478 }
479 }
480 }
482 /** Check that a given type can be cast to a given target type.
483 * Return the result of the cast.
484 * @param pos Position to be used for error reporting.
485 * @param found The type that is being cast.
486 * @param req The target type of the cast.
487 */
488 Type checkCastable(DiagnosticPosition pos, Type found, Type req) {
489 if (found.tag == FORALL) {
490 instantiatePoly(pos, (ForAll) found, req, castWarner(pos, found, req));
491 return req;
492 } else if (types.isCastable(found, req, castWarner(pos, found, req))) {
493 return req;
494 } else {
495 return typeError(pos,
496 diags.fragment("inconvertible.types"),
497 found, req);
498 }
499 }
500 //where
501 /** Is type a type variable, or a (possibly multi-dimensional) array of
502 * type variables?
503 */
504 boolean isTypeVar(Type t) {
505 return t.tag == TYPEVAR || t.tag == ARRAY && isTypeVar(types.elemtype(t));
506 }
508 /** Check that a type is within some bounds.
509 *
510 * Used in TypeApply to verify that, e.g., X in V<X> is a valid
511 * type argument.
512 * @param pos Position to be used for error reporting.
513 * @param a The type that should be bounded by bs.
514 * @param bs The bound.
515 */
516 private boolean checkExtends(Type a, TypeVar bs) {
517 if (a.isUnbound()) {
518 return true;
519 } else if (a.tag != WILDCARD) {
520 a = types.upperBound(a);
521 return types.isSubtype(a, bs.bound);
522 } else if (a.isExtendsBound()) {
523 return types.isCastable(bs.getUpperBound(), types.upperBound(a), Warner.noWarnings);
524 } else if (a.isSuperBound()) {
525 return !types.notSoftSubtype(types.lowerBound(a), bs.getUpperBound());
526 }
527 return true;
528 }
530 /** Check that type is different from 'void'.
531 * @param pos Position to be used for error reporting.
532 * @param t The type to be checked.
533 */
534 Type checkNonVoid(DiagnosticPosition pos, Type t) {
535 if (t.tag == VOID) {
536 log.error(pos, "void.not.allowed.here");
537 return types.createErrorType(t);
538 } else {
539 return t;
540 }
541 }
543 /** Check that type is a class or interface type.
544 * @param pos Position to be used for error reporting.
545 * @param t The type to be checked.
546 */
547 Type checkClassType(DiagnosticPosition pos, Type t) {
548 if (t.tag != CLASS && t.tag != ERROR)
549 return typeTagError(pos,
550 diags.fragment("type.req.class"),
551 (t.tag == TYPEVAR)
552 ? diags.fragment("type.parameter", t)
553 : t);
554 else
555 return t;
556 }
558 /** Check that type is a class or interface type.
559 * @param pos Position to be used for error reporting.
560 * @param t The type to be checked.
561 * @param noBounds True if type bounds are illegal here.
562 */
563 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) {
564 t = checkClassType(pos, t);
565 if (noBounds && t.isParameterized()) {
566 List<Type> args = t.getTypeArguments();
567 while (args.nonEmpty()) {
568 if (args.head.tag == WILDCARD)
569 return typeTagError(pos,
570 diags.fragment("type.req.exact"),
571 args.head);
572 args = args.tail;
573 }
574 }
575 return t;
576 }
578 /** Check that type is a reifiable class, interface or array type.
579 * @param pos Position to be used for error reporting.
580 * @param t The type to be checked.
581 */
582 Type checkReifiableReferenceType(DiagnosticPosition pos, Type t) {
583 if (t.tag != CLASS && t.tag != ARRAY && t.tag != ERROR) {
584 return typeTagError(pos,
585 diags.fragment("type.req.class.array"),
586 t);
587 } else if (!types.isReifiable(t)) {
588 log.error(pos, "illegal.generic.type.for.instof");
589 return types.createErrorType(t);
590 } else {
591 return t;
592 }
593 }
595 /** Check that type is a reference type, i.e. a class, interface or array type
596 * or a type variable.
597 * @param pos Position to be used for error reporting.
598 * @param t The type to be checked.
599 */
600 Type checkRefType(DiagnosticPosition pos, Type t) {
601 switch (t.tag) {
602 case CLASS:
603 case ARRAY:
604 case TYPEVAR:
605 case WILDCARD:
606 case ERROR:
607 return t;
608 default:
609 return typeTagError(pos,
610 diags.fragment("type.req.ref"),
611 t);
612 }
613 }
615 /** Check that each type is a reference type, i.e. a class, interface or array type
616 * or a type variable.
617 * @param trees Original trees, used for error reporting.
618 * @param types The types to be checked.
619 */
620 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) {
621 List<JCExpression> tl = trees;
622 for (List<Type> l = types; l.nonEmpty(); l = l.tail) {
623 l.head = checkRefType(tl.head.pos(), l.head);
624 tl = tl.tail;
625 }
626 return types;
627 }
629 /** Check that type is a null or reference type.
630 * @param pos Position to be used for error reporting.
631 * @param t The type to be checked.
632 */
633 Type checkNullOrRefType(DiagnosticPosition pos, Type t) {
634 switch (t.tag) {
635 case CLASS:
636 case ARRAY:
637 case TYPEVAR:
638 case WILDCARD:
639 case BOT:
640 case ERROR:
641 return t;
642 default:
643 return typeTagError(pos,
644 diags.fragment("type.req.ref"),
645 t);
646 }
647 }
649 /** Check that flag set does not contain elements of two conflicting sets. s
650 * Return true if it doesn't.
651 * @param pos Position to be used for error reporting.
652 * @param flags The set of flags to be checked.
653 * @param set1 Conflicting flags set #1.
654 * @param set2 Conflicting flags set #2.
655 */
656 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) {
657 if ((flags & set1) != 0 && (flags & set2) != 0) {
658 log.error(pos,
659 "illegal.combination.of.modifiers",
660 asFlagSet(TreeInfo.firstFlag(flags & set1)),
661 asFlagSet(TreeInfo.firstFlag(flags & set2)));
662 return false;
663 } else
664 return true;
665 }
667 /** Check that the type inferred using the diamond operator does not contain
668 * non-denotable types such as captured types or intersection types.
669 * @param t the type inferred using the diamond operator
670 */
671 List<Type> checkDiamond(ClassType t) {
672 DiamondTypeChecker dtc = new DiamondTypeChecker();
673 ListBuffer<Type> buf = ListBuffer.lb();
674 for (Type arg : t.getTypeArguments()) {
675 if (!dtc.visit(arg, null)) {
676 buf.append(arg);
677 }
678 }
679 return buf.toList();
680 }
682 static class DiamondTypeChecker extends Types.SimpleVisitor<Boolean, Void> {
683 public Boolean visitType(Type t, Void s) {
684 return true;
685 }
686 @Override
687 public Boolean visitClassType(ClassType t, Void s) {
688 if (t.isCompound()) {
689 return false;
690 }
691 for (Type targ : t.getTypeArguments()) {
692 if (!visit(targ, s)) {
693 return false;
694 }
695 }
696 return true;
697 }
698 @Override
699 public Boolean visitCapturedType(CapturedType t, Void s) {
700 return false;
701 }
702 }
704 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) {
705 MethodSymbol m = tree.sym;
706 if (!allowSimplifiedVarargs) return;
707 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null;
708 Type varargElemType = null;
709 if (m.isVarArgs()) {
710 varargElemType = types.elemtype(tree.params.last().type);
711 }
712 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) {
713 if (varargElemType != null) {
714 log.error(tree,
715 "varargs.invalid.trustme.anno",
716 syms.trustMeType.tsym,
717 diags.fragment("varargs.trustme.on.virtual.varargs", m));
718 } else {
719 log.error(tree,
720 "varargs.invalid.trustme.anno",
721 syms.trustMeType.tsym,
722 diags.fragment("varargs.trustme.on.non.varargs.meth", m));
723 }
724 } else if (hasTrustMeAnno && varargElemType != null &&
725 types.isReifiable(varargElemType)) {
726 warnUnsafeVararg(tree,
727 "varargs.redundant.trustme.anno",
728 syms.trustMeType.tsym,
729 diags.fragment("varargs.trustme.on.reifiable.varargs", varargElemType));
730 }
731 else if (!hasTrustMeAnno && varargElemType != null &&
732 !types.isReifiable(varargElemType)) {
733 warnUnchecked(tree.params.head.pos(), "unchecked.varargs.non.reifiable.type", varargElemType);
734 }
735 }
736 //where
737 private boolean isTrustMeAllowedOnMethod(Symbol s) {
738 return (s.flags() & VARARGS) != 0 &&
739 (s.isConstructor() ||
740 (s.flags() & (STATIC | FINAL)) != 0);
741 }
743 /**
744 * Check that vararg method call is sound
745 * @param pos Position to be used for error reporting.
746 * @param argtypes Actual arguments supplied to vararg method.
747 */
748 void checkVararg(DiagnosticPosition pos, List<Type> argtypes, Symbol msym) {
749 Type argtype = argtypes.last();
750 if (!types.isReifiable(argtype) &&
751 (!allowSimplifiedVarargs ||
752 msym.attribute(syms.trustMeType.tsym) == null ||
753 !isTrustMeAllowedOnMethod(msym))) {
754 warnUnchecked(pos,
755 "unchecked.generic.array.creation",
756 argtype);
757 }
758 }
760 /**
761 * Check that type 't' is a valid instantiation of a generic class
762 * (see JLS 4.5)
763 *
764 * @param t class type to be checked
765 * @return true if 't' is well-formed
766 */
767 public boolean checkValidGenericType(Type t) {
768 return firstIncompatibleTypeArg(t) == null;
769 }
770 //WHERE
771 private Type firstIncompatibleTypeArg(Type type) {
772 List<Type> formals = type.tsym.type.allparams();
773 List<Type> actuals = type.allparams();
774 List<Type> args = type.getTypeArguments();
775 List<Type> forms = type.tsym.type.getTypeArguments();
776 ListBuffer<Type> tvars_buf = new ListBuffer<Type>();
778 // For matching pairs of actual argument types `a' and
779 // formal type parameters with declared bound `b' ...
780 while (args.nonEmpty() && forms.nonEmpty()) {
781 // exact type arguments needs to know their
782 // bounds (for upper and lower bound
783 // calculations). So we create new TypeVars with
784 // bounds substed with actuals.
785 tvars_buf.append(types.substBound(((TypeVar)forms.head),
786 formals,
787 actuals));
788 args = args.tail;
789 forms = forms.tail;
790 }
792 args = type.getTypeArguments();
793 List<Type> tvars_cap = types.substBounds(formals,
794 formals,
795 types.capture(type).allparams());
796 while (args.nonEmpty() && tvars_cap.nonEmpty()) {
797 // Let the actual arguments know their bound
798 args.head.withTypeVar((TypeVar)tvars_cap.head);
799 args = args.tail;
800 tvars_cap = tvars_cap.tail;
801 }
803 args = type.getTypeArguments();
804 List<Type> tvars = tvars_buf.toList();
806 while (args.nonEmpty() && tvars.nonEmpty()) {
807 Type actual = types.subst(args.head,
808 type.tsym.type.getTypeArguments(),
809 tvars_buf.toList());
810 if (!checkExtends(actual, (TypeVar)tvars.head) &&
811 !tvars.head.getUpperBound().isErroneous()) {
812 return args.head;
813 }
814 args = args.tail;
815 tvars = tvars.tail;
816 }
818 args = type.getTypeArguments();
819 tvars = tvars_buf.toList();
821 for (Type arg : types.capture(type).getTypeArguments()) {
822 if (arg.tag == TYPEVAR &&
823 arg.getUpperBound().isErroneous() &&
824 !tvars.head.getUpperBound().isErroneous()) {
825 return args.head;
826 }
827 tvars = tvars.tail;
828 }
830 return null;
831 }
833 /** Check that given modifiers are legal for given symbol and
834 * return modifiers together with any implicit modififiers for that symbol.
835 * Warning: we can't use flags() here since this method
836 * is called during class enter, when flags() would cause a premature
837 * completion.
838 * @param pos Position to be used for error reporting.
839 * @param flags The set of modifiers given in a definition.
840 * @param sym The defined symbol.
841 */
842 long checkFlags(DiagnosticPosition pos, long flags, Symbol sym, JCTree tree) {
843 long mask;
844 long implicit = 0;
845 switch (sym.kind) {
846 case VAR:
847 if (sym.owner.kind != TYP)
848 mask = LocalVarFlags;
849 else if ((sym.owner.flags_field & INTERFACE) != 0)
850 mask = implicit = InterfaceVarFlags;
851 else
852 mask = VarFlags;
853 break;
854 case MTH:
855 if (sym.name == names.init) {
856 if ((sym.owner.flags_field & ENUM) != 0) {
857 // enum constructors cannot be declared public or
858 // protected and must be implicitly or explicitly
859 // private
860 implicit = PRIVATE;
861 mask = PRIVATE;
862 } else
863 mask = ConstructorFlags;
864 } else if ((sym.owner.flags_field & INTERFACE) != 0)
865 mask = implicit = InterfaceMethodFlags;
866 else {
867 mask = MethodFlags;
868 }
869 // Imply STRICTFP if owner has STRICTFP set.
870 if (((flags|implicit) & Flags.ABSTRACT) == 0)
871 implicit |= sym.owner.flags_field & STRICTFP;
872 break;
873 case TYP:
874 if (sym.isLocal()) {
875 mask = LocalClassFlags;
876 if (sym.name.isEmpty()) { // Anonymous class
877 // Anonymous classes in static methods are themselves static;
878 // that's why we admit STATIC here.
879 mask |= STATIC;
880 // JLS: Anonymous classes are final.
881 implicit |= FINAL;
882 }
883 if ((sym.owner.flags_field & STATIC) == 0 &&
884 (flags & ENUM) != 0)
885 log.error(pos, "enums.must.be.static");
886 } else if (sym.owner.kind == TYP) {
887 mask = MemberClassFlags;
888 if (sym.owner.owner.kind == PCK ||
889 (sym.owner.flags_field & STATIC) != 0)
890 mask |= STATIC;
891 else if ((flags & ENUM) != 0)
892 log.error(pos, "enums.must.be.static");
893 // Nested interfaces and enums are always STATIC (Spec ???)
894 if ((flags & (INTERFACE | ENUM)) != 0 ) implicit = STATIC;
895 } else {
896 mask = ClassFlags;
897 }
898 // Interfaces are always ABSTRACT
899 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT;
901 if ((flags & ENUM) != 0) {
902 // enums can't be declared abstract or final
903 mask &= ~(ABSTRACT | FINAL);
904 implicit |= implicitEnumFinalFlag(tree);
905 }
906 // Imply STRICTFP if owner has STRICTFP set.
907 implicit |= sym.owner.flags_field & STRICTFP;
908 break;
909 default:
910 throw new AssertionError();
911 }
912 long illegal = flags & StandardFlags & ~mask;
913 if (illegal != 0) {
914 if ((illegal & INTERFACE) != 0) {
915 log.error(pos, "intf.not.allowed.here");
916 mask |= INTERFACE;
917 }
918 else {
919 log.error(pos,
920 "mod.not.allowed.here", asFlagSet(illegal));
921 }
922 }
923 else if ((sym.kind == TYP ||
924 // ISSUE: Disallowing abstract&private is no longer appropriate
925 // in the presence of inner classes. Should it be deleted here?
926 checkDisjoint(pos, flags,
927 ABSTRACT,
928 PRIVATE | STATIC))
929 &&
930 checkDisjoint(pos, flags,
931 ABSTRACT | INTERFACE,
932 FINAL | NATIVE | SYNCHRONIZED)
933 &&
934 checkDisjoint(pos, flags,
935 PUBLIC,
936 PRIVATE | PROTECTED)
937 &&
938 checkDisjoint(pos, flags,
939 PRIVATE,
940 PUBLIC | PROTECTED)
941 &&
942 checkDisjoint(pos, flags,
943 FINAL,
944 VOLATILE)
945 &&
946 (sym.kind == TYP ||
947 checkDisjoint(pos, flags,
948 ABSTRACT | NATIVE,
949 STRICTFP))) {
950 // skip
951 }
952 return flags & (mask | ~StandardFlags) | implicit;
953 }
956 /** Determine if this enum should be implicitly final.
957 *
958 * If the enum has no specialized enum contants, it is final.
959 *
960 * If the enum does have specialized enum contants, it is
961 * <i>not</i> final.
962 */
963 private long implicitEnumFinalFlag(JCTree tree) {
964 if (tree.getTag() != JCTree.CLASSDEF) return 0;
965 class SpecialTreeVisitor extends JCTree.Visitor {
966 boolean specialized;
967 SpecialTreeVisitor() {
968 this.specialized = false;
969 };
971 @Override
972 public void visitTree(JCTree tree) { /* no-op */ }
974 @Override
975 public void visitVarDef(JCVariableDecl tree) {
976 if ((tree.mods.flags & ENUM) != 0) {
977 if (tree.init instanceof JCNewClass &&
978 ((JCNewClass) tree.init).def != null) {
979 specialized = true;
980 }
981 }
982 }
983 }
985 SpecialTreeVisitor sts = new SpecialTreeVisitor();
986 JCClassDecl cdef = (JCClassDecl) tree;
987 for (JCTree defs: cdef.defs) {
988 defs.accept(sts);
989 if (sts.specialized) return 0;
990 }
991 return FINAL;
992 }
994 /* *************************************************************************
995 * Type Validation
996 **************************************************************************/
998 /** Validate a type expression. That is,
999 * check that all type arguments of a parametric type are within
1000 * their bounds. This must be done in a second phase after type attributon
1001 * since a class might have a subclass as type parameter bound. E.g:
1002 *
1003 * class B<A extends C> { ... }
1004 * class C extends B<C> { ... }
1005 *
1006 * and we can't make sure that the bound is already attributed because
1007 * of possible cycles.
1008 *
1009 * Visitor method: Validate a type expression, if it is not null, catching
1010 * and reporting any completion failures.
1011 */
1012 void validate(JCTree tree, Env<AttrContext> env) {
1013 validate(tree, env, true);
1014 }
1015 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) {
1016 new Validator(env).validateTree(tree, checkRaw, true);
1017 }
1019 /** Visitor method: Validate a list of type expressions.
1020 */
1021 void validate(List<? extends JCTree> trees, Env<AttrContext> env) {
1022 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1023 validate(l.head, env);
1024 }
1026 /** A visitor class for type validation.
1027 */
1028 class Validator extends JCTree.Visitor {
1030 boolean isOuter;
1031 Env<AttrContext> env;
1033 Validator(Env<AttrContext> env) {
1034 this.env = env;
1035 }
1037 @Override
1038 public void visitTypeArray(JCArrayTypeTree tree) {
1039 tree.elemtype.accept(this);
1040 }
1042 @Override
1043 public void visitTypeApply(JCTypeApply tree) {
1044 if (tree.type.tag == CLASS) {
1045 List<JCExpression> args = tree.arguments;
1046 List<Type> forms = tree.type.tsym.type.getTypeArguments();
1048 Type incompatibleArg = firstIncompatibleTypeArg(tree.type);
1049 if (incompatibleArg != null) {
1050 for (JCTree arg : tree.arguments) {
1051 if (arg.type == incompatibleArg) {
1052 log.error(arg, "not.within.bounds", incompatibleArg, forms.head);
1053 }
1054 forms = forms.tail;
1055 }
1056 }
1058 forms = tree.type.tsym.type.getTypeArguments();
1060 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class;
1062 // For matching pairs of actual argument types `a' and
1063 // formal type parameters with declared bound `b' ...
1064 while (args.nonEmpty() && forms.nonEmpty()) {
1065 validateTree(args.head,
1066 !(isOuter && is_java_lang_Class),
1067 false);
1068 args = args.tail;
1069 forms = forms.tail;
1070 }
1072 // Check that this type is either fully parameterized, or
1073 // not parameterized at all.
1074 if (tree.type.getEnclosingType().isRaw())
1075 log.error(tree.pos(), "improperly.formed.type.inner.raw.param");
1076 if (tree.clazz.getTag() == JCTree.SELECT)
1077 visitSelectInternal((JCFieldAccess)tree.clazz);
1078 }
1079 }
1081 @Override
1082 public void visitTypeParameter(JCTypeParameter tree) {
1083 validateTrees(tree.bounds, true, isOuter);
1084 checkClassBounds(tree.pos(), tree.type);
1085 }
1087 @Override
1088 public void visitWildcard(JCWildcard tree) {
1089 if (tree.inner != null)
1090 validateTree(tree.inner, true, isOuter);
1091 }
1093 @Override
1094 public void visitSelect(JCFieldAccess tree) {
1095 if (tree.type.tag == CLASS) {
1096 visitSelectInternal(tree);
1098 // Check that this type is either fully parameterized, or
1099 // not parameterized at all.
1100 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty())
1101 log.error(tree.pos(), "improperly.formed.type.param.missing");
1102 }
1103 }
1105 public void visitSelectInternal(JCFieldAccess tree) {
1106 if (tree.type.tsym.isStatic() &&
1107 tree.selected.type.isParameterized()) {
1108 // The enclosing type is not a class, so we are
1109 // looking at a static member type. However, the
1110 // qualifying expression is parameterized.
1111 log.error(tree.pos(), "cant.select.static.class.from.param.type");
1112 } else {
1113 // otherwise validate the rest of the expression
1114 tree.selected.accept(this);
1115 }
1116 }
1118 /** Default visitor method: do nothing.
1119 */
1120 @Override
1121 public void visitTree(JCTree tree) {
1122 }
1124 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) {
1125 try {
1126 if (tree != null) {
1127 this.isOuter = isOuter;
1128 tree.accept(this);
1129 if (checkRaw)
1130 checkRaw(tree, env);
1131 }
1132 } catch (CompletionFailure ex) {
1133 completionError(tree.pos(), ex);
1134 }
1135 }
1137 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) {
1138 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
1139 validateTree(l.head, checkRaw, isOuter);
1140 }
1142 void checkRaw(JCTree tree, Env<AttrContext> env) {
1143 if (lint.isEnabled(LintCategory.RAW) &&
1144 tree.type.tag == CLASS &&
1145 !TreeInfo.isDiamond(tree) &&
1146 !env.enclClass.name.isEmpty() && //anonymous or intersection
1147 tree.type.isRaw()) {
1148 log.warning(LintCategory.RAW,
1149 tree.pos(), "raw.class.use", tree.type, tree.type.tsym.type);
1150 }
1151 }
1152 }
1154 /* *************************************************************************
1155 * Exception checking
1156 **************************************************************************/
1158 /* The following methods treat classes as sets that contain
1159 * the class itself and all their subclasses
1160 */
1162 /** Is given type a subtype of some of the types in given list?
1163 */
1164 boolean subset(Type t, List<Type> ts) {
1165 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1166 if (types.isSubtype(t, l.head)) return true;
1167 return false;
1168 }
1170 /** Is given type a subtype or supertype of
1171 * some of the types in given list?
1172 */
1173 boolean intersects(Type t, List<Type> ts) {
1174 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1175 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true;
1176 return false;
1177 }
1179 /** Add type set to given type list, unless it is a subclass of some class
1180 * in the list.
1181 */
1182 List<Type> incl(Type t, List<Type> ts) {
1183 return subset(t, ts) ? ts : excl(t, ts).prepend(t);
1184 }
1186 /** Remove type set from type set list.
1187 */
1188 List<Type> excl(Type t, List<Type> ts) {
1189 if (ts.isEmpty()) {
1190 return ts;
1191 } else {
1192 List<Type> ts1 = excl(t, ts.tail);
1193 if (types.isSubtype(ts.head, t)) return ts1;
1194 else if (ts1 == ts.tail) return ts;
1195 else return ts1.prepend(ts.head);
1196 }
1197 }
1199 /** Form the union of two type set lists.
1200 */
1201 List<Type> union(List<Type> ts1, List<Type> ts2) {
1202 List<Type> ts = ts1;
1203 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1204 ts = incl(l.head, ts);
1205 return ts;
1206 }
1208 /** Form the difference of two type lists.
1209 */
1210 List<Type> diff(List<Type> ts1, List<Type> ts2) {
1211 List<Type> ts = ts1;
1212 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1213 ts = excl(l.head, ts);
1214 return ts;
1215 }
1217 /** Form the intersection of two type lists.
1218 */
1219 public List<Type> intersect(List<Type> ts1, List<Type> ts2) {
1220 List<Type> ts = List.nil();
1221 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail)
1222 if (subset(l.head, ts2)) ts = incl(l.head, ts);
1223 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail)
1224 if (subset(l.head, ts1)) ts = incl(l.head, ts);
1225 return ts;
1226 }
1228 /** Is exc an exception symbol that need not be declared?
1229 */
1230 boolean isUnchecked(ClassSymbol exc) {
1231 return
1232 exc.kind == ERR ||
1233 exc.isSubClass(syms.errorType.tsym, types) ||
1234 exc.isSubClass(syms.runtimeExceptionType.tsym, types);
1235 }
1237 /** Is exc an exception type that need not be declared?
1238 */
1239 boolean isUnchecked(Type exc) {
1240 return
1241 (exc.tag == TYPEVAR) ? isUnchecked(types.supertype(exc)) :
1242 (exc.tag == CLASS) ? isUnchecked((ClassSymbol)exc.tsym) :
1243 exc.tag == BOT;
1244 }
1246 /** Same, but handling completion failures.
1247 */
1248 boolean isUnchecked(DiagnosticPosition pos, Type exc) {
1249 try {
1250 return isUnchecked(exc);
1251 } catch (CompletionFailure ex) {
1252 completionError(pos, ex);
1253 return true;
1254 }
1255 }
1257 /** Is exc handled by given exception list?
1258 */
1259 boolean isHandled(Type exc, List<Type> handled) {
1260 return isUnchecked(exc) || subset(exc, handled);
1261 }
1263 /** Return all exceptions in thrown list that are not in handled list.
1264 * @param thrown The list of thrown exceptions.
1265 * @param handled The list of handled exceptions.
1266 */
1267 List<Type> unhandled(List<Type> thrown, List<Type> handled) {
1268 List<Type> unhandled = List.nil();
1269 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail)
1270 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head);
1271 return unhandled;
1272 }
1274 /* *************************************************************************
1275 * Overriding/Implementation checking
1276 **************************************************************************/
1278 /** The level of access protection given by a flag set,
1279 * where PRIVATE is highest and PUBLIC is lowest.
1280 */
1281 static int protection(long flags) {
1282 switch ((short)(flags & AccessFlags)) {
1283 case PRIVATE: return 3;
1284 case PROTECTED: return 1;
1285 default:
1286 case PUBLIC: return 0;
1287 case 0: return 2;
1288 }
1289 }
1291 /** A customized "cannot override" error message.
1292 * @param m The overriding method.
1293 * @param other The overridden method.
1294 * @return An internationalized string.
1295 */
1296 Object cannotOverride(MethodSymbol m, MethodSymbol other) {
1297 String key;
1298 if ((other.owner.flags() & INTERFACE) == 0)
1299 key = "cant.override";
1300 else if ((m.owner.flags() & INTERFACE) == 0)
1301 key = "cant.implement";
1302 else
1303 key = "clashes.with";
1304 return diags.fragment(key, m, m.location(), other, other.location());
1305 }
1307 /** A customized "override" warning message.
1308 * @param m The overriding method.
1309 * @param other The overridden method.
1310 * @return An internationalized string.
1311 */
1312 Object uncheckedOverrides(MethodSymbol m, MethodSymbol other) {
1313 String key;
1314 if ((other.owner.flags() & INTERFACE) == 0)
1315 key = "unchecked.override";
1316 else if ((m.owner.flags() & INTERFACE) == 0)
1317 key = "unchecked.implement";
1318 else
1319 key = "unchecked.clash.with";
1320 return diags.fragment(key, m, m.location(), other, other.location());
1321 }
1323 /** A customized "override" warning message.
1324 * @param m The overriding method.
1325 * @param other The overridden method.
1326 * @return An internationalized string.
1327 */
1328 Object varargsOverrides(MethodSymbol m, MethodSymbol other) {
1329 String key;
1330 if ((other.owner.flags() & INTERFACE) == 0)
1331 key = "varargs.override";
1332 else if ((m.owner.flags() & INTERFACE) == 0)
1333 key = "varargs.implement";
1334 else
1335 key = "varargs.clash.with";
1336 return diags.fragment(key, m, m.location(), other, other.location());
1337 }
1339 /** Check that this method conforms with overridden method 'other'.
1340 * where `origin' is the class where checking started.
1341 * Complications:
1342 * (1) Do not check overriding of synthetic methods
1343 * (reason: they might be final).
1344 * todo: check whether this is still necessary.
1345 * (2) Admit the case where an interface proxy throws fewer exceptions
1346 * than the method it implements. Augment the proxy methods with the
1347 * undeclared exceptions in this case.
1348 * (3) When generics are enabled, admit the case where an interface proxy
1349 * has a result type
1350 * extended by the result type of the method it implements.
1351 * Change the proxies result type to the smaller type in this case.
1352 *
1353 * @param tree The tree from which positions
1354 * are extracted for errors.
1355 * @param m The overriding method.
1356 * @param other The overridden method.
1357 * @param origin The class of which the overriding method
1358 * is a member.
1359 */
1360 void checkOverride(JCTree tree,
1361 MethodSymbol m,
1362 MethodSymbol other,
1363 ClassSymbol origin) {
1364 // Don't check overriding of synthetic methods or by bridge methods.
1365 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) {
1366 return;
1367 }
1369 // Error if static method overrides instance method (JLS 8.4.6.2).
1370 if ((m.flags() & STATIC) != 0 &&
1371 (other.flags() & STATIC) == 0) {
1372 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.static",
1373 cannotOverride(m, other));
1374 return;
1375 }
1377 // Error if instance method overrides static or final
1378 // method (JLS 8.4.6.1).
1379 if ((other.flags() & FINAL) != 0 ||
1380 (m.flags() & STATIC) == 0 &&
1381 (other.flags() & STATIC) != 0) {
1382 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.meth",
1383 cannotOverride(m, other),
1384 asFlagSet(other.flags() & (FINAL | STATIC)));
1385 return;
1386 }
1388 if ((m.owner.flags() & ANNOTATION) != 0) {
1389 // handled in validateAnnotationMethod
1390 return;
1391 }
1393 // Error if overriding method has weaker access (JLS 8.4.6.3).
1394 if ((origin.flags() & INTERFACE) == 0 &&
1395 protection(m.flags()) > protection(other.flags())) {
1396 log.error(TreeInfo.diagnosticPositionFor(m, tree), "override.weaker.access",
1397 cannotOverride(m, other),
1398 other.flags() == 0 ?
1399 Flag.PACKAGE :
1400 asFlagSet(other.flags() & AccessFlags));
1401 return;
1402 }
1404 Type mt = types.memberType(origin.type, m);
1405 Type ot = types.memberType(origin.type, other);
1406 // Error if overriding result type is different
1407 // (or, in the case of generics mode, not a subtype) of
1408 // overridden result type. We have to rename any type parameters
1409 // before comparing types.
1410 List<Type> mtvars = mt.getTypeArguments();
1411 List<Type> otvars = ot.getTypeArguments();
1412 Type mtres = mt.getReturnType();
1413 Type otres = types.subst(ot.getReturnType(), otvars, mtvars);
1415 overrideWarner.clear();
1416 boolean resultTypesOK =
1417 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner);
1418 if (!resultTypesOK) {
1419 if (!allowCovariantReturns &&
1420 m.owner != origin &&
1421 m.owner.isSubClass(other.owner, types)) {
1422 // allow limited interoperability with covariant returns
1423 } else {
1424 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1425 "override.incompatible.ret",
1426 cannotOverride(m, other),
1427 mtres, otres);
1428 return;
1429 }
1430 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) {
1431 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1432 "override.unchecked.ret",
1433 uncheckedOverrides(m, other),
1434 mtres, otres);
1435 }
1437 // Error if overriding method throws an exception not reported
1438 // by overridden method.
1439 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars);
1440 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown));
1441 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown);
1442 if (unhandledErased.nonEmpty()) {
1443 log.error(TreeInfo.diagnosticPositionFor(m, tree),
1444 "override.meth.doesnt.throw",
1445 cannotOverride(m, other),
1446 unhandledUnerased.head);
1447 return;
1448 }
1449 else if (unhandledUnerased.nonEmpty()) {
1450 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree),
1451 "override.unchecked.thrown",
1452 cannotOverride(m, other),
1453 unhandledUnerased.head);
1454 return;
1455 }
1457 // Optional warning if varargs don't agree
1458 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)
1459 && lint.isEnabled(LintCategory.OVERRIDES)) {
1460 log.warning(TreeInfo.diagnosticPositionFor(m, tree),
1461 ((m.flags() & Flags.VARARGS) != 0)
1462 ? "override.varargs.missing"
1463 : "override.varargs.extra",
1464 varargsOverrides(m, other));
1465 }
1467 // Warn if instance method overrides bridge method (compiler spec ??)
1468 if ((other.flags() & BRIDGE) != 0) {
1469 log.warning(TreeInfo.diagnosticPositionFor(m, tree), "override.bridge",
1470 uncheckedOverrides(m, other));
1471 }
1473 // Warn if a deprecated method overridden by a non-deprecated one.
1474 if (!isDeprecatedOverrideIgnorable(other, origin)) {
1475 checkDeprecated(TreeInfo.diagnosticPositionFor(m, tree), m, other);
1476 }
1477 }
1478 // where
1479 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) {
1480 // If the method, m, is defined in an interface, then ignore the issue if the method
1481 // is only inherited via a supertype and also implemented in the supertype,
1482 // because in that case, we will rediscover the issue when examining the method
1483 // in the supertype.
1484 // If the method, m, is not defined in an interface, then the only time we need to
1485 // address the issue is when the method is the supertype implemementation: any other
1486 // case, we will have dealt with when examining the supertype classes
1487 ClassSymbol mc = m.enclClass();
1488 Type st = types.supertype(origin.type);
1489 if (st.tag != CLASS)
1490 return true;
1491 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false);
1493 if (mc != null && ((mc.flags() & INTERFACE) != 0)) {
1494 List<Type> intfs = types.interfaces(origin.type);
1495 return (intfs.contains(mc.type) ? false : (stimpl != null));
1496 }
1497 else
1498 return (stimpl != m);
1499 }
1502 // used to check if there were any unchecked conversions
1503 Warner overrideWarner = new Warner();
1505 /** Check that a class does not inherit two concrete methods
1506 * with the same signature.
1507 * @param pos Position to be used for error reporting.
1508 * @param site The class type to be checked.
1509 */
1510 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) {
1511 Type sup = types.supertype(site);
1512 if (sup.tag != CLASS) return;
1514 for (Type t1 = sup;
1515 t1.tsym.type.isParameterized();
1516 t1 = types.supertype(t1)) {
1517 for (Scope.Entry e1 = t1.tsym.members().elems;
1518 e1 != null;
1519 e1 = e1.sibling) {
1520 Symbol s1 = e1.sym;
1521 if (s1.kind != MTH ||
1522 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1523 !s1.isInheritedIn(site.tsym, types) ||
1524 ((MethodSymbol)s1).implementation(site.tsym,
1525 types,
1526 true) != s1)
1527 continue;
1528 Type st1 = types.memberType(t1, s1);
1529 int s1ArgsLength = st1.getParameterTypes().length();
1530 if (st1 == s1.type) continue;
1532 for (Type t2 = sup;
1533 t2.tag == CLASS;
1534 t2 = types.supertype(t2)) {
1535 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name);
1536 e2.scope != null;
1537 e2 = e2.next()) {
1538 Symbol s2 = e2.sym;
1539 if (s2 == s1 ||
1540 s2.kind != MTH ||
1541 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 ||
1542 s2.type.getParameterTypes().length() != s1ArgsLength ||
1543 !s2.isInheritedIn(site.tsym, types) ||
1544 ((MethodSymbol)s2).implementation(site.tsym,
1545 types,
1546 true) != s2)
1547 continue;
1548 Type st2 = types.memberType(t2, s2);
1549 if (types.overrideEquivalent(st1, st2))
1550 log.error(pos, "concrete.inheritance.conflict",
1551 s1, t1, s2, t2, sup);
1552 }
1553 }
1554 }
1555 }
1556 }
1558 /** Check that classes (or interfaces) do not each define an abstract
1559 * method with same name and arguments but incompatible return types.
1560 * @param pos Position to be used for error reporting.
1561 * @param t1 The first argument type.
1562 * @param t2 The second argument type.
1563 */
1564 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1565 Type t1,
1566 Type t2) {
1567 return checkCompatibleAbstracts(pos, t1, t2,
1568 types.makeCompoundType(t1, t2));
1569 }
1571 public boolean checkCompatibleAbstracts(DiagnosticPosition pos,
1572 Type t1,
1573 Type t2,
1574 Type site) {
1575 return firstIncompatibility(pos, t1, t2, site) == null;
1576 }
1578 /** Return the first method which is defined with same args
1579 * but different return types in two given interfaces, or null if none
1580 * exists.
1581 * @param t1 The first type.
1582 * @param t2 The second type.
1583 * @param site The most derived type.
1584 * @returns symbol from t2 that conflicts with one in t1.
1585 */
1586 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1587 Map<TypeSymbol,Type> interfaces1 = new HashMap<TypeSymbol,Type>();
1588 closure(t1, interfaces1);
1589 Map<TypeSymbol,Type> interfaces2;
1590 if (t1 == t2)
1591 interfaces2 = interfaces1;
1592 else
1593 closure(t2, interfaces1, interfaces2 = new HashMap<TypeSymbol,Type>());
1595 for (Type t3 : interfaces1.values()) {
1596 for (Type t4 : interfaces2.values()) {
1597 Symbol s = firstDirectIncompatibility(pos, t3, t4, site);
1598 if (s != null) return s;
1599 }
1600 }
1601 return null;
1602 }
1604 /** Compute all the supertypes of t, indexed by type symbol. */
1605 private void closure(Type t, Map<TypeSymbol,Type> typeMap) {
1606 if (t.tag != CLASS) return;
1607 if (typeMap.put(t.tsym, t) == null) {
1608 closure(types.supertype(t), typeMap);
1609 for (Type i : types.interfaces(t))
1610 closure(i, typeMap);
1611 }
1612 }
1614 /** Compute all the supertypes of t, indexed by type symbol (except thise in typesSkip). */
1615 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) {
1616 if (t.tag != CLASS) return;
1617 if (typesSkip.get(t.tsym) != null) return;
1618 if (typeMap.put(t.tsym, t) == null) {
1619 closure(types.supertype(t), typesSkip, typeMap);
1620 for (Type i : types.interfaces(t))
1621 closure(i, typesSkip, typeMap);
1622 }
1623 }
1625 /** Return the first method in t2 that conflicts with a method from t1. */
1626 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) {
1627 for (Scope.Entry e1 = t1.tsym.members().elems; e1 != null; e1 = e1.sibling) {
1628 Symbol s1 = e1.sym;
1629 Type st1 = null;
1630 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types)) continue;
1631 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false);
1632 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue;
1633 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name); e2.scope != null; e2 = e2.next()) {
1634 Symbol s2 = e2.sym;
1635 if (s1 == s2) continue;
1636 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types)) continue;
1637 if (st1 == null) st1 = types.memberType(t1, s1);
1638 Type st2 = types.memberType(t2, s2);
1639 if (types.overrideEquivalent(st1, st2)) {
1640 List<Type> tvars1 = st1.getTypeArguments();
1641 List<Type> tvars2 = st2.getTypeArguments();
1642 Type rt1 = st1.getReturnType();
1643 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1);
1644 boolean compat =
1645 types.isSameType(rt1, rt2) ||
1646 rt1.tag >= CLASS && rt2.tag >= CLASS &&
1647 (types.covariantReturnType(rt1, rt2, Warner.noWarnings) ||
1648 types.covariantReturnType(rt2, rt1, Warner.noWarnings)) ||
1649 checkCommonOverriderIn(s1,s2,site);
1650 if (!compat) {
1651 log.error(pos, "types.incompatible.diff.ret",
1652 t1, t2, s2.name +
1653 "(" + types.memberType(t2, s2).getParameterTypes() + ")");
1654 return s2;
1655 }
1656 } else if (!checkNameClash((ClassSymbol)site.tsym, s1, s2)) {
1657 log.error(pos,
1658 "name.clash.same.erasure.no.override",
1659 s1, s1.location(),
1660 s2, s2.location());
1661 return s2;
1662 }
1663 }
1664 }
1665 return null;
1666 }
1667 //WHERE
1668 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) {
1669 Map<TypeSymbol,Type> supertypes = new HashMap<TypeSymbol,Type>();
1670 Type st1 = types.memberType(site, s1);
1671 Type st2 = types.memberType(site, s2);
1672 closure(site, supertypes);
1673 for (Type t : supertypes.values()) {
1674 for (Scope.Entry e = t.tsym.members().lookup(s1.name); e.scope != null; e = e.next()) {
1675 Symbol s3 = e.sym;
1676 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue;
1677 Type st3 = types.memberType(site,s3);
1678 if (types.overrideEquivalent(st3, st1) && types.overrideEquivalent(st3, st2)) {
1679 if (s3.owner == site.tsym) {
1680 return true;
1681 }
1682 List<Type> tvars1 = st1.getTypeArguments();
1683 List<Type> tvars2 = st2.getTypeArguments();
1684 List<Type> tvars3 = st3.getTypeArguments();
1685 Type rt1 = st1.getReturnType();
1686 Type rt2 = st2.getReturnType();
1687 Type rt13 = types.subst(st3.getReturnType(), tvars3, tvars1);
1688 Type rt23 = types.subst(st3.getReturnType(), tvars3, tvars2);
1689 boolean compat =
1690 rt13.tag >= CLASS && rt23.tag >= CLASS &&
1691 (types.covariantReturnType(rt13, rt1, Warner.noWarnings) &&
1692 types.covariantReturnType(rt23, rt2, Warner.noWarnings));
1693 if (compat)
1694 return true;
1695 }
1696 }
1697 }
1698 return false;
1699 }
1701 /** Check that a given method conforms with any method it overrides.
1702 * @param tree The tree from which positions are extracted
1703 * for errors.
1704 * @param m The overriding method.
1705 */
1706 void checkOverride(JCTree tree, MethodSymbol m) {
1707 ClassSymbol origin = (ClassSymbol)m.owner;
1708 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name))
1709 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) {
1710 log.error(tree.pos(), "enum.no.finalize");
1711 return;
1712 }
1713 for (Type t = origin.type; t.tag == CLASS;
1714 t = types.supertype(t)) {
1715 if (t != origin.type) {
1716 checkOverride(tree, t, origin, m);
1717 }
1718 for (Type t2 : types.interfaces(t)) {
1719 checkOverride(tree, t2, origin, m);
1720 }
1721 }
1722 }
1724 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) {
1725 TypeSymbol c = site.tsym;
1726 Scope.Entry e = c.members().lookup(m.name);
1727 while (e.scope != null) {
1728 if (m.overrides(e.sym, origin, types, false)) {
1729 if ((e.sym.flags() & ABSTRACT) == 0) {
1730 checkOverride(tree, m, (MethodSymbol)e.sym, origin);
1731 }
1732 }
1733 e = e.next();
1734 }
1735 }
1737 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) {
1738 if (s1.kind == MTH &&
1739 s1.isInheritedIn(origin, types) &&
1740 (s1.flags() & SYNTHETIC) == 0 &&
1741 !s2.isConstructor()) {
1742 Type er1 = s2.erasure(types);
1743 Type er2 = s1.erasure(types);
1744 if (types.isSameTypes(er1.getParameterTypes(),
1745 er2.getParameterTypes())) {
1746 return false;
1747 }
1748 }
1749 return true;
1750 }
1753 /** Check that all abstract members of given class have definitions.
1754 * @param pos Position to be used for error reporting.
1755 * @param c The class.
1756 */
1757 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) {
1758 try {
1759 MethodSymbol undef = firstUndef(c, c);
1760 if (undef != null) {
1761 if ((c.flags() & ENUM) != 0 &&
1762 types.supertype(c.type).tsym == syms.enumSym &&
1763 (c.flags() & FINAL) == 0) {
1764 // add the ABSTRACT flag to an enum
1765 c.flags_field |= ABSTRACT;
1766 } else {
1767 MethodSymbol undef1 =
1768 new MethodSymbol(undef.flags(), undef.name,
1769 types.memberType(c.type, undef), undef.owner);
1770 log.error(pos, "does.not.override.abstract",
1771 c, undef1, undef1.location());
1772 }
1773 }
1774 } catch (CompletionFailure ex) {
1775 completionError(pos, ex);
1776 }
1777 }
1778 //where
1779 /** Return first abstract member of class `c' that is not defined
1780 * in `impl', null if there is none.
1781 */
1782 private MethodSymbol firstUndef(ClassSymbol impl, ClassSymbol c) {
1783 MethodSymbol undef = null;
1784 // Do not bother to search in classes that are not abstract,
1785 // since they cannot have abstract members.
1786 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
1787 Scope s = c.members();
1788 for (Scope.Entry e = s.elems;
1789 undef == null && e != null;
1790 e = e.sibling) {
1791 if (e.sym.kind == MTH &&
1792 (e.sym.flags() & (ABSTRACT|IPROXY)) == ABSTRACT) {
1793 MethodSymbol absmeth = (MethodSymbol)e.sym;
1794 MethodSymbol implmeth = absmeth.implementation(impl, types, true);
1795 if (implmeth == null || implmeth == absmeth)
1796 undef = absmeth;
1797 }
1798 }
1799 if (undef == null) {
1800 Type st = types.supertype(c.type);
1801 if (st.tag == CLASS)
1802 undef = firstUndef(impl, (ClassSymbol)st.tsym);
1803 }
1804 for (List<Type> l = types.interfaces(c.type);
1805 undef == null && l.nonEmpty();
1806 l = l.tail) {
1807 undef = firstUndef(impl, (ClassSymbol)l.head.tsym);
1808 }
1809 }
1810 return undef;
1811 }
1813 void checkNonCyclicDecl(JCClassDecl tree) {
1814 CycleChecker cc = new CycleChecker();
1815 cc.scan(tree);
1816 if (!cc.errorFound && !cc.partialCheck) {
1817 tree.sym.flags_field |= ACYCLIC;
1818 }
1819 }
1821 class CycleChecker extends TreeScanner {
1823 List<Symbol> seenClasses = List.nil();
1824 boolean errorFound = false;
1825 boolean partialCheck = false;
1827 private void checkSymbol(DiagnosticPosition pos, Symbol sym) {
1828 if (sym != null && sym.kind == TYP) {
1829 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym);
1830 if (classEnv != null) {
1831 DiagnosticSource prevSource = log.currentSource();
1832 try {
1833 log.useSource(classEnv.toplevel.sourcefile);
1834 scan(classEnv.tree);
1835 }
1836 finally {
1837 log.useSource(prevSource.getFile());
1838 }
1839 } else if (sym.kind == TYP) {
1840 checkClass(pos, sym, List.<JCTree>nil());
1841 }
1842 } else {
1843 //not completed yet
1844 partialCheck = true;
1845 }
1846 }
1848 @Override
1849 public void visitSelect(JCFieldAccess tree) {
1850 super.visitSelect(tree);
1851 checkSymbol(tree.pos(), tree.sym);
1852 }
1854 @Override
1855 public void visitIdent(JCIdent tree) {
1856 checkSymbol(tree.pos(), tree.sym);
1857 }
1859 @Override
1860 public void visitTypeApply(JCTypeApply tree) {
1861 scan(tree.clazz);
1862 }
1864 @Override
1865 public void visitTypeArray(JCArrayTypeTree tree) {
1866 scan(tree.elemtype);
1867 }
1869 @Override
1870 public void visitClassDef(JCClassDecl tree) {
1871 List<JCTree> supertypes = List.nil();
1872 if (tree.getExtendsClause() != null) {
1873 supertypes = supertypes.prepend(tree.getExtendsClause());
1874 }
1875 if (tree.getImplementsClause() != null) {
1876 for (JCTree intf : tree.getImplementsClause()) {
1877 supertypes = supertypes.prepend(intf);
1878 }
1879 }
1880 checkClass(tree.pos(), tree.sym, supertypes);
1881 }
1883 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) {
1884 if ((c.flags_field & ACYCLIC) != 0)
1885 return;
1886 if (seenClasses.contains(c)) {
1887 errorFound = true;
1888 noteCyclic(pos, (ClassSymbol)c);
1889 } else if (!c.type.isErroneous()) {
1890 try {
1891 seenClasses = seenClasses.prepend(c);
1892 if (c.type.tag == CLASS) {
1893 if (supertypes.nonEmpty()) {
1894 scan(supertypes);
1895 }
1896 else {
1897 ClassType ct = (ClassType)c.type;
1898 if (ct.supertype_field == null ||
1899 ct.interfaces_field == null) {
1900 //not completed yet
1901 partialCheck = true;
1902 return;
1903 }
1904 checkSymbol(pos, ct.supertype_field.tsym);
1905 for (Type intf : ct.interfaces_field) {
1906 checkSymbol(pos, intf.tsym);
1907 }
1908 }
1909 if (c.owner.kind == TYP) {
1910 checkSymbol(pos, c.owner);
1911 }
1912 }
1913 } finally {
1914 seenClasses = seenClasses.tail;
1915 }
1916 }
1917 }
1918 }
1920 /** Check for cyclic references. Issue an error if the
1921 * symbol of the type referred to has a LOCKED flag set.
1922 *
1923 * @param pos Position to be used for error reporting.
1924 * @param t The type referred to.
1925 */
1926 void checkNonCyclic(DiagnosticPosition pos, Type t) {
1927 checkNonCyclicInternal(pos, t);
1928 }
1931 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
1932 checkNonCyclic1(pos, t, List.<TypeVar>nil());
1933 }
1935 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
1936 final TypeVar tv;
1937 if (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
1938 return;
1939 if (seen.contains(t)) {
1940 tv = (TypeVar)t;
1941 tv.bound = types.createErrorType(t);
1942 log.error(pos, "cyclic.inheritance", t);
1943 } else if (t.tag == TYPEVAR) {
1944 tv = (TypeVar)t;
1945 seen = seen.prepend(tv);
1946 for (Type b : types.getBounds(tv))
1947 checkNonCyclic1(pos, b, seen);
1948 }
1949 }
1951 /** Check for cyclic references. Issue an error if the
1952 * symbol of the type referred to has a LOCKED flag set.
1953 *
1954 * @param pos Position to be used for error reporting.
1955 * @param t The type referred to.
1956 * @returns True if the check completed on all attributed classes
1957 */
1958 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) {
1959 boolean complete = true; // was the check complete?
1960 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG
1961 Symbol c = t.tsym;
1962 if ((c.flags_field & ACYCLIC) != 0) return true;
1964 if ((c.flags_field & LOCKED) != 0) {
1965 noteCyclic(pos, (ClassSymbol)c);
1966 } else if (!c.type.isErroneous()) {
1967 try {
1968 c.flags_field |= LOCKED;
1969 if (c.type.tag == CLASS) {
1970 ClassType clazz = (ClassType)c.type;
1971 if (clazz.interfaces_field != null)
1972 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail)
1973 complete &= checkNonCyclicInternal(pos, l.head);
1974 if (clazz.supertype_field != null) {
1975 Type st = clazz.supertype_field;
1976 if (st != null && st.tag == CLASS)
1977 complete &= checkNonCyclicInternal(pos, st);
1978 }
1979 if (c.owner.kind == TYP)
1980 complete &= checkNonCyclicInternal(pos, c.owner.type);
1981 }
1982 } finally {
1983 c.flags_field &= ~LOCKED;
1984 }
1985 }
1986 if (complete)
1987 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.completer == null;
1988 if (complete) c.flags_field |= ACYCLIC;
1989 return complete;
1990 }
1992 /** Note that we found an inheritance cycle. */
1993 private void noteCyclic(DiagnosticPosition pos, ClassSymbol c) {
1994 log.error(pos, "cyclic.inheritance", c);
1995 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail)
1996 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType);
1997 Type st = types.supertype(c.type);
1998 if (st.tag == CLASS)
1999 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType);
2000 c.type = types.createErrorType(c, c.type);
2001 c.flags_field |= ACYCLIC;
2002 }
2004 /** Check that all methods which implement some
2005 * method conform to the method they implement.
2006 * @param tree The class definition whose members are checked.
2007 */
2008 void checkImplementations(JCClassDecl tree) {
2009 checkImplementations(tree, tree.sym);
2010 }
2011 //where
2012 /** Check that all methods which implement some
2013 * method in `ic' conform to the method they implement.
2014 */
2015 void checkImplementations(JCClassDecl tree, ClassSymbol ic) {
2016 ClassSymbol origin = tree.sym;
2017 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) {
2018 ClassSymbol lc = (ClassSymbol)l.head.tsym;
2019 if ((allowGenerics || origin != lc) && (lc.flags() & ABSTRACT) != 0) {
2020 for (Scope.Entry e=lc.members().elems; e != null; e=e.sibling) {
2021 if (e.sym.kind == MTH &&
2022 (e.sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) {
2023 MethodSymbol absmeth = (MethodSymbol)e.sym;
2024 MethodSymbol implmeth = absmeth.implementation(origin, types, false);
2025 if (implmeth != null && implmeth != absmeth &&
2026 (implmeth.owner.flags() & INTERFACE) ==
2027 (origin.flags() & INTERFACE)) {
2028 // don't check if implmeth is in a class, yet
2029 // origin is an interface. This case arises only
2030 // if implmeth is declared in Object. The reason is
2031 // that interfaces really don't inherit from
2032 // Object it's just that the compiler represents
2033 // things that way.
2034 checkOverride(tree, implmeth, absmeth, origin);
2035 }
2036 }
2037 }
2038 }
2039 }
2040 }
2042 /** Check that all abstract methods implemented by a class are
2043 * mutually compatible.
2044 * @param pos Position to be used for error reporting.
2045 * @param c The class whose interfaces are checked.
2046 */
2047 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) {
2048 List<Type> supertypes = types.interfaces(c);
2049 Type supertype = types.supertype(c);
2050 if (supertype.tag == CLASS &&
2051 (supertype.tsym.flags() & ABSTRACT) != 0)
2052 supertypes = supertypes.prepend(supertype);
2053 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2054 if (allowGenerics && !l.head.getTypeArguments().isEmpty() &&
2055 !checkCompatibleAbstracts(pos, l.head, l.head, c))
2056 return;
2057 for (List<Type> m = supertypes; m != l; m = m.tail)
2058 if (!checkCompatibleAbstracts(pos, l.head, m.head, c))
2059 return;
2060 }
2061 checkCompatibleConcretes(pos, c);
2062 }
2064 void checkConflicts(DiagnosticPosition pos, Symbol sym, TypeSymbol c) {
2065 for (Type ct = c.type; ct != Type.noType ; ct = types.supertype(ct)) {
2066 for (Scope.Entry e = ct.tsym.members().lookup(sym.name); e.scope == ct.tsym.members(); e = e.next()) {
2067 // VM allows methods and variables with differing types
2068 if (sym.kind == e.sym.kind &&
2069 types.isSameType(types.erasure(sym.type), types.erasure(e.sym.type)) &&
2070 sym != e.sym &&
2071 (sym.flags() & Flags.SYNTHETIC) != (e.sym.flags() & Flags.SYNTHETIC) &&
2072 (sym.flags() & IPROXY) == 0 && (e.sym.flags() & IPROXY) == 0 &&
2073 (sym.flags() & BRIDGE) == 0 && (e.sym.flags() & BRIDGE) == 0) {
2074 syntheticError(pos, (e.sym.flags() & SYNTHETIC) == 0 ? e.sym : sym);
2075 return;
2076 }
2077 }
2078 }
2079 }
2081 /** Check that all non-override equivalent methods accessible from 'site'
2082 * are mutually compatible (JLS 8.4.8/9.4.1).
2083 *
2084 * @param pos Position to be used for error reporting.
2085 * @param site The class whose methods are checked.
2086 * @param sym The method symbol to be checked.
2087 */
2088 void checkClashes(DiagnosticPosition pos, Type site, Symbol sym) {
2089 List<Type> supertypes = types.closure(site);
2090 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) {
2091 for (List<Type> m = supertypes; m.nonEmpty(); m = m.tail) {
2092 checkClashes(pos, l.head, m.head, site, sym);
2093 }
2094 }
2095 }
2097 /** Reports an error whenever 'sym' seen as a member of type 't1' clashes with
2098 * some unrelated method defined in 't2'.
2099 */
2100 private void checkClashes(DiagnosticPosition pos, Type t1, Type t2, Type site, Symbol s1) {
2101 ClashFilter cf = new ClashFilter(site);
2102 s1 = ((MethodSymbol)s1).implementedIn(t1.tsym, types);
2103 if (s1 == null) return;
2104 Type st1 = types.memberType(site, s1);
2105 for (Scope.Entry e2 = t2.tsym.members().lookup(s1.name, cf); e2.scope != null; e2 = e2.next(cf)) {
2106 Symbol s2 = e2.sym;
2107 if (s1 == s2) continue;
2108 Type st2 = types.memberType(site, s2);
2109 if (!types.overrideEquivalent(st1, st2) &&
2110 !checkNameClash((ClassSymbol)site.tsym, s1, s2)) {
2111 log.error(pos,
2112 "name.clash.same.erasure.no.override",
2113 s1, s1.location(),
2114 s2, s2.location());
2115 }
2116 }
2117 }
2118 //where
2119 private class ClashFilter implements Filter<Symbol> {
2121 Type site;
2123 ClashFilter(Type site) {
2124 this.site = site;
2125 }
2127 public boolean accepts(Symbol s) {
2128 return s.kind == MTH &&
2129 (s.flags() & (SYNTHETIC | CLASH)) == 0 &&
2130 s.isInheritedIn(site.tsym, types) &&
2131 !s.isConstructor();
2132 }
2133 }
2135 /** Report a conflict between a user symbol and a synthetic symbol.
2136 */
2137 private void syntheticError(DiagnosticPosition pos, Symbol sym) {
2138 if (!sym.type.isErroneous()) {
2139 if (warnOnSyntheticConflicts) {
2140 log.warning(pos, "synthetic.name.conflict", sym, sym.location());
2141 }
2142 else {
2143 log.error(pos, "synthetic.name.conflict", sym, sym.location());
2144 }
2145 }
2146 }
2148 /** Check that class c does not implement directly or indirectly
2149 * the same parameterized interface with two different argument lists.
2150 * @param pos Position to be used for error reporting.
2151 * @param type The type whose interfaces are checked.
2152 */
2153 void checkClassBounds(DiagnosticPosition pos, Type type) {
2154 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type);
2155 }
2156 //where
2157 /** Enter all interfaces of type `type' into the hash table `seensofar'
2158 * with their class symbol as key and their type as value. Make
2159 * sure no class is entered with two different types.
2160 */
2161 void checkClassBounds(DiagnosticPosition pos,
2162 Map<TypeSymbol,Type> seensofar,
2163 Type type) {
2164 if (type.isErroneous()) return;
2165 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) {
2166 Type it = l.head;
2167 Type oldit = seensofar.put(it.tsym, it);
2168 if (oldit != null) {
2169 List<Type> oldparams = oldit.allparams();
2170 List<Type> newparams = it.allparams();
2171 if (!types.containsTypeEquivalent(oldparams, newparams))
2172 log.error(pos, "cant.inherit.diff.arg",
2173 it.tsym, Type.toString(oldparams),
2174 Type.toString(newparams));
2175 }
2176 checkClassBounds(pos, seensofar, it);
2177 }
2178 Type st = types.supertype(type);
2179 if (st != null) checkClassBounds(pos, seensofar, st);
2180 }
2182 /** Enter interface into into set.
2183 * If it existed already, issue a "repeated interface" error.
2184 */
2185 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Type> its) {
2186 if (its.contains(it))
2187 log.error(pos, "repeated.interface");
2188 else {
2189 its.add(it);
2190 }
2191 }
2193 /* *************************************************************************
2194 * Check annotations
2195 **************************************************************************/
2197 /**
2198 * Recursively validate annotations values
2199 */
2200 void validateAnnotationTree(JCTree tree) {
2201 class AnnotationValidator extends TreeScanner {
2202 @Override
2203 public void visitAnnotation(JCAnnotation tree) {
2204 super.visitAnnotation(tree);
2205 validateAnnotation(tree);
2206 }
2207 }
2208 tree.accept(new AnnotationValidator());
2209 }
2211 /** Annotation types are restricted to primitives, String, an
2212 * enum, an annotation, Class, Class<?>, Class<? extends
2213 * Anything>, arrays of the preceding.
2214 */
2215 void validateAnnotationType(JCTree restype) {
2216 // restype may be null if an error occurred, so don't bother validating it
2217 if (restype != null) {
2218 validateAnnotationType(restype.pos(), restype.type);
2219 }
2220 }
2222 void validateAnnotationType(DiagnosticPosition pos, Type type) {
2223 if (type.isPrimitive()) return;
2224 if (types.isSameType(type, syms.stringType)) return;
2225 if ((type.tsym.flags() & Flags.ENUM) != 0) return;
2226 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return;
2227 if (types.lowerBound(type).tsym == syms.classType.tsym) return;
2228 if (types.isArray(type) && !types.isArray(types.elemtype(type))) {
2229 validateAnnotationType(pos, types.elemtype(type));
2230 return;
2231 }
2232 log.error(pos, "invalid.annotation.member.type");
2233 }
2235 /**
2236 * "It is also a compile-time error if any method declared in an
2237 * annotation type has a signature that is override-equivalent to
2238 * that of any public or protected method declared in class Object
2239 * or in the interface annotation.Annotation."
2240 *
2241 * @jls3 9.6 Annotation Types
2242 */
2243 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) {
2244 for (Type sup = syms.annotationType; sup.tag == CLASS; sup = types.supertype(sup)) {
2245 Scope s = sup.tsym.members();
2246 for (Scope.Entry e = s.lookup(m.name); e.scope != null; e = e.next()) {
2247 if (e.sym.kind == MTH &&
2248 (e.sym.flags() & (PUBLIC | PROTECTED)) != 0 &&
2249 types.overrideEquivalent(m.type, e.sym.type))
2250 log.error(pos, "intf.annotation.member.clash", e.sym, sup);
2251 }
2252 }
2253 }
2255 /** Check the annotations of a symbol.
2256 */
2257 public void validateAnnotations(List<JCAnnotation> annotations, Symbol s) {
2258 if (skipAnnotations) return;
2259 for (JCAnnotation a : annotations)
2260 validateAnnotation(a, s);
2261 }
2263 /** Check an annotation of a symbol.
2264 */
2265 public void validateAnnotation(JCAnnotation a, Symbol s) {
2266 validateAnnotationTree(a);
2268 if (!annotationApplicable(a, s))
2269 log.error(a.pos(), "annotation.type.not.applicable");
2271 if (a.annotationType.type.tsym == syms.overrideType.tsym) {
2272 if (!isOverrider(s))
2273 log.error(a.pos(), "method.does.not.override.superclass");
2274 }
2275 }
2277 /** Is s a method symbol that overrides a method in a superclass? */
2278 boolean isOverrider(Symbol s) {
2279 if (s.kind != MTH || s.isStatic())
2280 return false;
2281 MethodSymbol m = (MethodSymbol)s;
2282 TypeSymbol owner = (TypeSymbol)m.owner;
2283 for (Type sup : types.closure(owner.type)) {
2284 if (sup == owner.type)
2285 continue; // skip "this"
2286 Scope scope = sup.tsym.members();
2287 for (Scope.Entry e = scope.lookup(m.name); e.scope != null; e = e.next()) {
2288 if (!e.sym.isStatic() && m.overrides(e.sym, owner, types, true))
2289 return true;
2290 }
2291 }
2292 return false;
2293 }
2295 /** Is the annotation applicable to the symbol? */
2296 boolean annotationApplicable(JCAnnotation a, Symbol s) {
2297 Attribute.Compound atTarget =
2298 a.annotationType.type.tsym.attribute(syms.annotationTargetType.tsym);
2299 if (atTarget == null) return true;
2300 Attribute atValue = atTarget.member(names.value);
2301 if (!(atValue instanceof Attribute.Array)) return true; // error recovery
2302 Attribute.Array arr = (Attribute.Array) atValue;
2303 for (Attribute app : arr.values) {
2304 if (!(app instanceof Attribute.Enum)) return true; // recovery
2305 Attribute.Enum e = (Attribute.Enum) app;
2306 if (e.value.name == names.TYPE)
2307 { if (s.kind == TYP) return true; }
2308 else if (e.value.name == names.FIELD)
2309 { if (s.kind == VAR && s.owner.kind != MTH) return true; }
2310 else if (e.value.name == names.METHOD)
2311 { if (s.kind == MTH && !s.isConstructor()) return true; }
2312 else if (e.value.name == names.PARAMETER)
2313 { if (s.kind == VAR &&
2314 s.owner.kind == MTH &&
2315 (s.flags() & PARAMETER) != 0)
2316 return true;
2317 }
2318 else if (e.value.name == names.CONSTRUCTOR)
2319 { if (s.kind == MTH && s.isConstructor()) return true; }
2320 else if (e.value.name == names.LOCAL_VARIABLE)
2321 { if (s.kind == VAR && s.owner.kind == MTH &&
2322 (s.flags() & PARAMETER) == 0)
2323 return true;
2324 }
2325 else if (e.value.name == names.ANNOTATION_TYPE)
2326 { if (s.kind == TYP && (s.flags() & ANNOTATION) != 0)
2327 return true;
2328 }
2329 else if (e.value.name == names.PACKAGE)
2330 { if (s.kind == PCK) return true; }
2331 else if (e.value.name == names.TYPE_USE)
2332 { if (s.kind == TYP ||
2333 s.kind == VAR ||
2334 (s.kind == MTH && !s.isConstructor() &&
2335 s.type.getReturnType().tag != VOID))
2336 return true;
2337 }
2338 else
2339 return true; // recovery
2340 }
2341 return false;
2342 }
2344 /** Check an annotation value.
2345 */
2346 public void validateAnnotation(JCAnnotation a) {
2347 if (a.type.isErroneous()) return;
2349 // collect an inventory of the members (sorted alphabetically)
2350 Set<MethodSymbol> members = new TreeSet<MethodSymbol>(new Comparator<Symbol>() {
2351 public int compare(Symbol t, Symbol t1) {
2352 return t.name.compareTo(t1.name);
2353 }
2354 });
2355 for (Scope.Entry e = a.annotationType.type.tsym.members().elems;
2356 e != null;
2357 e = e.sibling)
2358 if (e.sym.kind == MTH)
2359 members.add((MethodSymbol) e.sym);
2361 // count them off as they're annotated
2362 for (JCTree arg : a.args) {
2363 if (arg.getTag() != JCTree.ASSIGN) continue; // recovery
2364 JCAssign assign = (JCAssign) arg;
2365 Symbol m = TreeInfo.symbol(assign.lhs);
2366 if (m == null || m.type.isErroneous()) continue;
2367 if (!members.remove(m))
2368 log.error(assign.lhs.pos(), "duplicate.annotation.member.value",
2369 m.name, a.type);
2370 }
2372 // all the remaining ones better have default values
2373 ListBuffer<Name> missingDefaults = ListBuffer.lb();
2374 for (MethodSymbol m : members) {
2375 if (m.defaultValue == null && !m.type.isErroneous()) {
2376 missingDefaults.append(m.name);
2377 }
2378 }
2379 if (missingDefaults.nonEmpty()) {
2380 String key = (missingDefaults.size() > 1)
2381 ? "annotation.missing.default.value.1"
2382 : "annotation.missing.default.value";
2383 log.error(a.pos(), key, a.type, missingDefaults);
2384 }
2386 // special case: java.lang.annotation.Target must not have
2387 // repeated values in its value member
2388 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym ||
2389 a.args.tail == null)
2390 return;
2392 if (a.args.head.getTag() != JCTree.ASSIGN) return; // error recovery
2393 JCAssign assign = (JCAssign) a.args.head;
2394 Symbol m = TreeInfo.symbol(assign.lhs);
2395 if (m.name != names.value) return;
2396 JCTree rhs = assign.rhs;
2397 if (rhs.getTag() != JCTree.NEWARRAY) return;
2398 JCNewArray na = (JCNewArray) rhs;
2399 Set<Symbol> targets = new HashSet<Symbol>();
2400 for (JCTree elem : na.elems) {
2401 if (!targets.add(TreeInfo.symbol(elem))) {
2402 log.error(elem.pos(), "repeated.annotation.target");
2403 }
2404 }
2405 }
2407 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) {
2408 if (allowAnnotations &&
2409 lint.isEnabled(LintCategory.DEP_ANN) &&
2410 (s.flags() & DEPRECATED) != 0 &&
2411 !syms.deprecatedType.isErroneous() &&
2412 s.attribute(syms.deprecatedType.tsym) == null) {
2413 log.warning(LintCategory.DEP_ANN,
2414 pos, "missing.deprecated.annotation");
2415 }
2416 }
2418 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) {
2419 if ((s.flags() & DEPRECATED) != 0 &&
2420 (other.flags() & DEPRECATED) == 0 &&
2421 s.outermostClass() != other.outermostClass()) {
2422 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
2423 @Override
2424 public void report() {
2425 warnDeprecated(pos, s);
2426 }
2427 });
2428 };
2429 }
2431 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) {
2432 if ((s.flags() & PROPRIETARY) != 0) {
2433 deferredLintHandler.report(new DeferredLintHandler.LintLogger() {
2434 public void report() {
2435 if (enableSunApiLintControl)
2436 warnSunApi(pos, "sun.proprietary", s);
2437 else
2438 log.strictWarning(pos, "sun.proprietary", s);
2439 }
2440 });
2441 }
2442 }
2444 /* *************************************************************************
2445 * Check for recursive annotation elements.
2446 **************************************************************************/
2448 /** Check for cycles in the graph of annotation elements.
2449 */
2450 void checkNonCyclicElements(JCClassDecl tree) {
2451 if ((tree.sym.flags_field & ANNOTATION) == 0) return;
2452 Assert.check((tree.sym.flags_field & LOCKED) == 0);
2453 try {
2454 tree.sym.flags_field |= LOCKED;
2455 for (JCTree def : tree.defs) {
2456 if (def.getTag() != JCTree.METHODDEF) continue;
2457 JCMethodDecl meth = (JCMethodDecl)def;
2458 checkAnnotationResType(meth.pos(), meth.restype.type);
2459 }
2460 } finally {
2461 tree.sym.flags_field &= ~LOCKED;
2462 tree.sym.flags_field |= ACYCLIC_ANN;
2463 }
2464 }
2466 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) {
2467 if ((tsym.flags_field & ACYCLIC_ANN) != 0)
2468 return;
2469 if ((tsym.flags_field & LOCKED) != 0) {
2470 log.error(pos, "cyclic.annotation.element");
2471 return;
2472 }
2473 try {
2474 tsym.flags_field |= LOCKED;
2475 for (Scope.Entry e = tsym.members().elems; e != null; e = e.sibling) {
2476 Symbol s = e.sym;
2477 if (s.kind != Kinds.MTH)
2478 continue;
2479 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType());
2480 }
2481 } finally {
2482 tsym.flags_field &= ~LOCKED;
2483 tsym.flags_field |= ACYCLIC_ANN;
2484 }
2485 }
2487 void checkAnnotationResType(DiagnosticPosition pos, Type type) {
2488 switch (type.tag) {
2489 case TypeTags.CLASS:
2490 if ((type.tsym.flags() & ANNOTATION) != 0)
2491 checkNonCyclicElementsInternal(pos, type.tsym);
2492 break;
2493 case TypeTags.ARRAY:
2494 checkAnnotationResType(pos, types.elemtype(type));
2495 break;
2496 default:
2497 break; // int etc
2498 }
2499 }
2501 /* *************************************************************************
2502 * Check for cycles in the constructor call graph.
2503 **************************************************************************/
2505 /** Check for cycles in the graph of constructors calling other
2506 * constructors.
2507 */
2508 void checkCyclicConstructors(JCClassDecl tree) {
2509 Map<Symbol,Symbol> callMap = new HashMap<Symbol, Symbol>();
2511 // enter each constructor this-call into the map
2512 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) {
2513 JCMethodInvocation app = TreeInfo.firstConstructorCall(l.head);
2514 if (app == null) continue;
2515 JCMethodDecl meth = (JCMethodDecl) l.head;
2516 if (TreeInfo.name(app.meth) == names._this) {
2517 callMap.put(meth.sym, TreeInfo.symbol(app.meth));
2518 } else {
2519 meth.sym.flags_field |= ACYCLIC;
2520 }
2521 }
2523 // Check for cycles in the map
2524 Symbol[] ctors = new Symbol[0];
2525 ctors = callMap.keySet().toArray(ctors);
2526 for (Symbol caller : ctors) {
2527 checkCyclicConstructor(tree, caller, callMap);
2528 }
2529 }
2531 /** Look in the map to see if the given constructor is part of a
2532 * call cycle.
2533 */
2534 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor,
2535 Map<Symbol,Symbol> callMap) {
2536 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) {
2537 if ((ctor.flags_field & LOCKED) != 0) {
2538 log.error(TreeInfo.diagnosticPositionFor(ctor, tree),
2539 "recursive.ctor.invocation");
2540 } else {
2541 ctor.flags_field |= LOCKED;
2542 checkCyclicConstructor(tree, callMap.remove(ctor), callMap);
2543 ctor.flags_field &= ~LOCKED;
2544 }
2545 ctor.flags_field |= ACYCLIC;
2546 }
2547 }
2549 /* *************************************************************************
2550 * Miscellaneous
2551 **************************************************************************/
2553 /**
2554 * Return the opcode of the operator but emit an error if it is an
2555 * error.
2556 * @param pos position for error reporting.
2557 * @param operator an operator
2558 * @param tag a tree tag
2559 * @param left type of left hand side
2560 * @param right type of right hand side
2561 */
2562 int checkOperator(DiagnosticPosition pos,
2563 OperatorSymbol operator,
2564 int tag,
2565 Type left,
2566 Type right) {
2567 if (operator.opcode == ByteCodes.error) {
2568 log.error(pos,
2569 "operator.cant.be.applied",
2570 treeinfo.operatorName(tag),
2571 List.of(left, right));
2572 }
2573 return operator.opcode;
2574 }
2577 /**
2578 * Check for division by integer constant zero
2579 * @param pos Position for error reporting.
2580 * @param operator The operator for the expression
2581 * @param operand The right hand operand for the expression
2582 */
2583 void checkDivZero(DiagnosticPosition pos, Symbol operator, Type operand) {
2584 if (operand.constValue() != null
2585 && lint.isEnabled(LintCategory.DIVZERO)
2586 && operand.tag <= LONG
2587 && ((Number) (operand.constValue())).longValue() == 0) {
2588 int opc = ((OperatorSymbol)operator).opcode;
2589 if (opc == ByteCodes.idiv || opc == ByteCodes.imod
2590 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) {
2591 log.warning(LintCategory.DIVZERO, pos, "div.zero");
2592 }
2593 }
2594 }
2596 /**
2597 * Check for empty statements after if
2598 */
2599 void checkEmptyIf(JCIf tree) {
2600 if (tree.thenpart.getTag() == JCTree.SKIP && tree.elsepart == null && lint.isEnabled(LintCategory.EMPTY))
2601 log.warning(LintCategory.EMPTY, tree.thenpart.pos(), "empty.if");
2602 }
2604 /** Check that symbol is unique in given scope.
2605 * @param pos Position for error reporting.
2606 * @param sym The symbol.
2607 * @param s The scope.
2608 */
2609 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) {
2610 if (sym.type.isErroneous())
2611 return true;
2612 if (sym.owner.name == names.any) return false;
2613 for (Scope.Entry e = s.lookup(sym.name); e.scope == s; e = e.next()) {
2614 if (sym != e.sym &&
2615 (e.sym.flags() & CLASH) == 0 &&
2616 sym.kind == e.sym.kind &&
2617 sym.name != names.error &&
2618 (sym.kind != MTH || types.hasSameArgs(types.erasure(sym.type), types.erasure(e.sym.type)))) {
2619 if ((sym.flags() & VARARGS) != (e.sym.flags() & VARARGS)) {
2620 varargsDuplicateError(pos, sym, e.sym);
2621 return true;
2622 } else if (sym.kind == MTH && !hasSameSignature(sym.type, e.sym.type)) {
2623 duplicateErasureError(pos, sym, e.sym);
2624 sym.flags_field |= CLASH;
2625 return true;
2626 } else {
2627 duplicateError(pos, e.sym);
2628 return false;
2629 }
2630 }
2631 }
2632 return true;
2633 }
2634 //where
2635 boolean hasSameSignature(Type mt1, Type mt2) {
2636 if (mt1.tag == FORALL && mt2.tag == FORALL) {
2637 ForAll fa1 = (ForAll)mt1;
2638 ForAll fa2 = (ForAll)mt2;
2639 mt2 = types.subst(fa2, fa2.tvars, fa1.tvars);
2640 }
2641 return types.hasSameArgs(mt1.asMethodType(), mt2.asMethodType());
2642 }
2644 /** Report duplicate declaration error.
2645 */
2646 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) {
2647 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) {
2648 log.error(pos, "name.clash.same.erasure", sym1, sym2);
2649 }
2650 }
2652 /** Check that single-type import is not already imported or top-level defined,
2653 * but make an exception for two single-type imports which denote the same type.
2654 * @param pos Position for error reporting.
2655 * @param sym The symbol.
2656 * @param s The scope
2657 */
2658 boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2659 return checkUniqueImport(pos, sym, s, false);
2660 }
2662 /** Check that static single-type import is not already imported or top-level defined,
2663 * but make an exception for two single-type imports which denote the same type.
2664 * @param pos Position for error reporting.
2665 * @param sym The symbol.
2666 * @param s The scope
2667 * @param staticImport Whether or not this was a static import
2668 */
2669 boolean checkUniqueStaticImport(DiagnosticPosition pos, Symbol sym, Scope s) {
2670 return checkUniqueImport(pos, sym, s, true);
2671 }
2673 /** Check that single-type import is not already imported or top-level defined,
2674 * but make an exception for two single-type imports which denote the same type.
2675 * @param pos Position for error reporting.
2676 * @param sym The symbol.
2677 * @param s The scope.
2678 * @param staticImport Whether or not this was a static import
2679 */
2680 private boolean checkUniqueImport(DiagnosticPosition pos, Symbol sym, Scope s, boolean staticImport) {
2681 for (Scope.Entry e = s.lookup(sym.name); e.scope != null; e = e.next()) {
2682 // is encountered class entered via a class declaration?
2683 boolean isClassDecl = e.scope == s;
2684 if ((isClassDecl || sym != e.sym) &&
2685 sym.kind == e.sym.kind &&
2686 sym.name != names.error) {
2687 if (!e.sym.type.isErroneous()) {
2688 String what = e.sym.toString();
2689 if (!isClassDecl) {
2690 if (staticImport)
2691 log.error(pos, "already.defined.static.single.import", what);
2692 else
2693 log.error(pos, "already.defined.single.import", what);
2694 }
2695 else if (sym != e.sym)
2696 log.error(pos, "already.defined.this.unit", what);
2697 }
2698 return false;
2699 }
2700 }
2701 return true;
2702 }
2704 /** Check that a qualified name is in canonical form (for import decls).
2705 */
2706 public void checkCanonical(JCTree tree) {
2707 if (!isCanonical(tree))
2708 log.error(tree.pos(), "import.requires.canonical",
2709 TreeInfo.symbol(tree));
2710 }
2711 // where
2712 private boolean isCanonical(JCTree tree) {
2713 while (tree.getTag() == JCTree.SELECT) {
2714 JCFieldAccess s = (JCFieldAccess) tree;
2715 if (s.sym.owner != TreeInfo.symbol(s.selected))
2716 return false;
2717 tree = s.selected;
2718 }
2719 return true;
2720 }
2722 private class ConversionWarner extends Warner {
2723 final String uncheckedKey;
2724 final Type found;
2725 final Type expected;
2726 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) {
2727 super(pos);
2728 this.uncheckedKey = uncheckedKey;
2729 this.found = found;
2730 this.expected = expected;
2731 }
2733 @Override
2734 public void warn(LintCategory lint) {
2735 boolean warned = this.warned;
2736 super.warn(lint);
2737 if (warned) return; // suppress redundant diagnostics
2738 switch (lint) {
2739 case UNCHECKED:
2740 Check.this.warnUnchecked(pos(), "prob.found.req", diags.fragment(uncheckedKey), found, expected);
2741 break;
2742 case VARARGS:
2743 if (method != null &&
2744 method.attribute(syms.trustMeType.tsym) != null &&
2745 isTrustMeAllowedOnMethod(method) &&
2746 !types.isReifiable(method.type.getParameterTypes().last())) {
2747 Check.this.warnUnsafeVararg(pos(), "varargs.unsafe.use.varargs.param", method.params.last());
2748 }
2749 break;
2750 default:
2751 throw new AssertionError("Unexpected lint: " + lint);
2752 }
2753 }
2754 }
2756 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) {
2757 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected);
2758 }
2760 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) {
2761 return new ConversionWarner(pos, "unchecked.assign", found, expected);
2762 }
2763 }
