1 /* 2 * Copyright (c) 1999, 2025, 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 */ 25 26 package com.sun.tools.javac.comp; 27 28 import java.util.*; 29 import java.util.function.BiConsumer; 30 import java.util.function.BiPredicate; 31 import java.util.function.Predicate; 32 import java.util.function.Supplier; 33 import java.util.function.ToIntBiFunction; 34 import java.util.stream.Collectors; 35 import java.util.stream.StreamSupport; 36 37 import javax.lang.model.element.ElementKind; 38 import javax.lang.model.element.NestingKind; 39 import javax.tools.JavaFileManager; 40 41 import com.sun.source.tree.CaseTree; 42 import com.sun.tools.javac.code.*; 43 import com.sun.tools.javac.code.Attribute.Compound; 44 import com.sun.tools.javac.code.Directive.ExportsDirective; 45 import com.sun.tools.javac.code.Directive.RequiresDirective; 46 import com.sun.tools.javac.code.Source.Feature; 47 import com.sun.tools.javac.comp.Annotate.AnnotationTypeMetadata; 48 import com.sun.tools.javac.jvm.*; 49 import com.sun.tools.javac.resources.CompilerProperties.Errors; 50 import com.sun.tools.javac.resources.CompilerProperties.Fragments; 51 import com.sun.tools.javac.resources.CompilerProperties.Warnings; 52 import com.sun.tools.javac.resources.CompilerProperties.LintWarnings; 53 import com.sun.tools.javac.tree.*; 54 import com.sun.tools.javac.util.*; 55 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag; 56 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 57 import com.sun.tools.javac.util.JCDiagnostic.Error; 58 import com.sun.tools.javac.util.JCDiagnostic.Fragment; 59 import com.sun.tools.javac.util.JCDiagnostic.LintWarning; 60 import com.sun.tools.javac.util.List; 61 62 import com.sun.tools.javac.code.Lint; 63 import com.sun.tools.javac.code.Lint.LintCategory; 64 import com.sun.tools.javac.code.Scope.WriteableScope; 65 import com.sun.tools.javac.code.Type.*; 66 import com.sun.tools.javac.code.Symbol.*; 67 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext; 68 import com.sun.tools.javac.tree.JCTree.*; 69 70 import static com.sun.tools.javac.code.Flags.*; 71 import static com.sun.tools.javac.code.Flags.ANNOTATION; 72 import static com.sun.tools.javac.code.Flags.SYNCHRONIZED; 73 import static com.sun.tools.javac.code.Kinds.*; 74 import static com.sun.tools.javac.code.Kinds.Kind.*; 75 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 76 import static com.sun.tools.javac.code.Scope.LookupKind.RECURSIVE; 77 import static com.sun.tools.javac.code.TypeTag.*; 78 import static com.sun.tools.javac.code.TypeTag.WILDCARD; 79 80 import static com.sun.tools.javac.tree.JCTree.Tag.*; 81 import javax.lang.model.element.Element; 82 import javax.lang.model.element.TypeElement; 83 import javax.lang.model.type.DeclaredType; 84 import javax.lang.model.util.ElementKindVisitor14; 85 86 /** Type checking helper class for the attribution phase. 87 * 88 * <p><b>This is NOT part of any supported API. 89 * If you write code that depends on this, you do so at your own risk. 90 * This code and its internal interfaces are subject to change or 91 * deletion without notice.</b> 92 */ 93 public class Check { 94 protected static final Context.Key<Check> checkKey = new Context.Key<>(); 95 96 // Flag bits indicating which item(s) chosen from a pair of items 97 private static final int FIRST = 0x01; 98 private static final int SECOND = 0x02; 99 100 private final Names names; 101 private final Log log; 102 private final Resolve rs; 103 private final Symtab syms; 104 private final Enter enter; 105 private final DeferredAttr deferredAttr; 106 private final Infer infer; 107 private final Types types; 108 private final TypeAnnotations typeAnnotations; 109 private final JCDiagnostic.Factory diags; 110 private final JavaFileManager fileManager; 111 private final Source source; 112 private final Target target; 113 private final Profile profile; 114 private final Preview preview; 115 private final boolean warnOnAnyAccessToMembers; 116 117 public boolean disablePreviewCheck; 118 119 // The set of lint options currently in effect. It is initialized 120 // from the context, and then is set/reset as needed by Attr as it 121 // visits all the various parts of the trees during attribution. 122 Lint lint; 123 124 // The method being analyzed in Attr - it is set/reset as needed by 125 // Attr as it visits new method declarations. 126 private MethodSymbol method; 127 128 public static Check instance(Context context) { 129 Check instance = context.get(checkKey); 130 if (instance == null) 131 instance = new Check(context); 132 return instance; 133 } 134 135 @SuppressWarnings("this-escape") 136 protected Check(Context context) { 137 context.put(checkKey, this); 138 139 names = Names.instance(context); 140 log = Log.instance(context); 141 rs = Resolve.instance(context); 142 syms = Symtab.instance(context); 143 enter = Enter.instance(context); 144 deferredAttr = DeferredAttr.instance(context); 145 infer = Infer.instance(context); 146 types = Types.instance(context); 147 typeAnnotations = TypeAnnotations.instance(context); 148 diags = JCDiagnostic.Factory.instance(context); 149 Options options = Options.instance(context); 150 lint = Lint.instance(context); 151 fileManager = context.get(JavaFileManager.class); 152 153 source = Source.instance(context); 154 target = Target.instance(context); 155 warnOnAnyAccessToMembers = options.isSet("warnOnAccessToMembers"); 156 157 disablePreviewCheck = false; 158 159 Target target = Target.instance(context); 160 syntheticNameChar = target.syntheticNameChar(); 161 162 profile = Profile.instance(context); 163 preview = Preview.instance(context); 164 165 boolean verboseDeprecated = lint.isEnabled(LintCategory.DEPRECATION); 166 boolean verboseRemoval = lint.isEnabled(LintCategory.REMOVAL); 167 boolean verboseUnchecked = lint.isEnabled(LintCategory.UNCHECKED); 168 boolean enforceMandatoryWarnings = true; 169 170 deprecationHandler = new MandatoryWarningHandler(log, null, verboseDeprecated, 171 enforceMandatoryWarnings, LintCategory.DEPRECATION, "deprecated"); 172 removalHandler = new MandatoryWarningHandler(log, null, verboseRemoval, 173 enforceMandatoryWarnings, LintCategory.REMOVAL); 174 uncheckedHandler = new MandatoryWarningHandler(log, null, verboseUnchecked, 175 enforceMandatoryWarnings, LintCategory.UNCHECKED); 176 177 deferredLintHandler = DeferredLintHandler.instance(context); 178 179 allowModules = Feature.MODULES.allowedInSource(source); 180 allowRecords = Feature.RECORDS.allowedInSource(source); 181 allowSealed = Feature.SEALED_CLASSES.allowedInSource(source); 182 allowValueClasses = (!preview.isPreview(Feature.VALUE_CLASSES) || preview.isEnabled()) && 183 Feature.VALUE_CLASSES.allowedInSource(source); 184 } 185 186 /** Character for synthetic names 187 */ 188 char syntheticNameChar; 189 190 /** A table mapping flat names of all compiled classes for each module in this run 191 * to their symbols; maintained from outside. 192 */ 193 private Map<Pair<ModuleSymbol, Name>,ClassSymbol> compiled = new HashMap<>(); 194 195 /** A handler for messages about deprecated usage. 196 */ 197 private MandatoryWarningHandler deprecationHandler; 198 199 /** A handler for messages about deprecated-for-removal usage. 200 */ 201 private MandatoryWarningHandler removalHandler; 202 203 /** A handler for messages about unchecked or unsafe usage. 204 */ 205 private MandatoryWarningHandler uncheckedHandler; 206 207 /** A handler for deferred lint warnings. 208 */ 209 private DeferredLintHandler deferredLintHandler; 210 211 /** Are modules allowed 212 */ 213 private final boolean allowModules; 214 215 /** Are records allowed 216 */ 217 private final boolean allowRecords; 218 219 /** Are sealed classes allowed 220 */ 221 private final boolean allowSealed; 222 223 /** Are value classes allowed 224 */ 225 private final boolean allowValueClasses; 226 227 /* ************************************************************************* 228 * Errors and Warnings 229 **************************************************************************/ 230 231 Lint setLint(Lint newLint) { 232 Lint prev = lint; 233 lint = newLint; 234 return prev; 235 } 236 237 MethodSymbol setMethod(MethodSymbol newMethod) { 238 MethodSymbol prev = method; 239 method = newMethod; 240 return prev; 241 } 242 243 /** Warn about deprecated symbol. 244 * @param pos Position to be used for error reporting. 245 * @param sym The deprecated symbol. 246 */ 247 void warnDeprecated(DiagnosticPosition pos, Symbol sym) { 248 if (sym.isDeprecatedForRemoval()) { 249 if (!lint.isSuppressed(LintCategory.REMOVAL)) { 250 if (sym.kind == MDL) { 251 removalHandler.report(pos, LintWarnings.HasBeenDeprecatedForRemovalModule(sym)); 252 } else { 253 removalHandler.report(pos, LintWarnings.HasBeenDeprecatedForRemoval(sym, sym.location())); 254 } 255 } 256 } else if (!lint.isSuppressed(LintCategory.DEPRECATION)) { 257 if (sym.kind == MDL) { 258 deprecationHandler.report(pos, LintWarnings.HasBeenDeprecatedModule(sym)); 259 } else { 260 deprecationHandler.report(pos, LintWarnings.HasBeenDeprecated(sym, sym.location())); 261 } 262 } 263 } 264 265 /** Log a preview warning. 266 * @param pos Position to be used for error reporting. 267 * @param msg A Warning describing the problem. 268 */ 269 public void warnPreviewAPI(DiagnosticPosition pos, LintWarning warnKey) { 270 if (!lint.isSuppressed(LintCategory.PREVIEW)) 271 preview.reportPreviewWarning(pos, warnKey); 272 } 273 274 /** Log a preview warning. 275 * @param pos Position to be used for error reporting. 276 * @param msg A Warning describing the problem. 277 */ 278 public void warnDeclaredUsingPreview(DiagnosticPosition pos, Symbol sym) { 279 if (!lint.isSuppressed(LintCategory.PREVIEW)) 280 preview.reportPreviewWarning(pos, LintWarnings.DeclaredUsingPreview(kindName(sym), sym)); 281 } 282 283 /** Log a preview warning. 284 * @param pos Position to be used for error reporting. 285 * @param msg A Warning describing the problem. 286 */ 287 public void warnRestrictedAPI(DiagnosticPosition pos, Symbol sym) { 288 lint.logIfEnabled(pos, LintWarnings.RestrictedMethod(sym.enclClass(), sym)); 289 } 290 291 /** Warn about unchecked operation. 292 * @param pos Position to be used for error reporting. 293 * @param msg A string describing the problem. 294 */ 295 public void warnUnchecked(DiagnosticPosition pos, LintWarning warnKey) { 296 if (!lint.isSuppressed(LintCategory.UNCHECKED)) 297 uncheckedHandler.report(pos, warnKey); 298 } 299 300 /** 301 * Report any deferred diagnostics. 302 */ 303 public void reportDeferredDiagnostics() { 304 deprecationHandler.reportDeferredDiagnostic(); 305 removalHandler.reportDeferredDiagnostic(); 306 uncheckedHandler.reportDeferredDiagnostic(); 307 } 308 309 310 /** Report a failure to complete a class. 311 * @param pos Position to be used for error reporting. 312 * @param ex The failure to report. 313 */ 314 public Type completionError(DiagnosticPosition pos, CompletionFailure ex) { 315 log.error(JCDiagnostic.DiagnosticFlag.NON_DEFERRABLE, pos, Errors.CantAccess(ex.sym, ex.getDetailValue())); 316 return syms.errType; 317 } 318 319 /** Report an error that wrong type tag was found. 320 * @param pos Position to be used for error reporting. 321 * @param required An internationalized string describing the type tag 322 * required. 323 * @param found The type that was found. 324 */ 325 Type typeTagError(DiagnosticPosition pos, JCDiagnostic required, Object found) { 326 // this error used to be raised by the parser, 327 // but has been delayed to this point: 328 if (found instanceof Type type && type.hasTag(VOID)) { 329 log.error(pos, Errors.IllegalStartOfType); 330 return syms.errType; 331 } 332 log.error(pos, Errors.TypeFoundReq(found, required)); 333 return types.createErrorType(found instanceof Type type ? type : syms.errType); 334 } 335 336 /** Report duplicate declaration error. 337 */ 338 void duplicateError(DiagnosticPosition pos, Symbol sym) { 339 if (!sym.type.isErroneous()) { 340 Symbol location = sym.location(); 341 if (location.kind == MTH && 342 ((MethodSymbol)location).isStaticOrInstanceInit()) { 343 log.error(pos, 344 Errors.AlreadyDefinedInClinit(kindName(sym), 345 sym, 346 kindName(sym.location()), 347 kindName(sym.location().enclClass()), 348 sym.location().enclClass())); 349 } else { 350 /* dont error if this is a duplicated parameter of a generated canonical constructor 351 * as we should have issued an error for the duplicated fields 352 */ 353 if (location.kind != MTH || 354 ((sym.owner.flags_field & GENERATEDCONSTR) == 0) || 355 ((sym.owner.flags_field & RECORD) == 0)) { 356 log.error(pos, 357 Errors.AlreadyDefined(kindName(sym), 358 sym, 359 kindName(sym.location()), 360 sym.location())); 361 } 362 } 363 } 364 } 365 366 /** Report array/varargs duplicate declaration 367 */ 368 void varargsDuplicateError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) { 369 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) { 370 log.error(pos, Errors.ArrayAndVarargs(sym1, sym2, sym2.location())); 371 } 372 } 373 374 /* ************************************************************************ 375 * duplicate declaration checking 376 *************************************************************************/ 377 378 /** Check that variable does not hide variable with same name in 379 * immediately enclosing local scope. 380 * @param pos Position for error reporting. 381 * @param v The symbol. 382 * @param s The scope. 383 */ 384 void checkTransparentVar(DiagnosticPosition pos, VarSymbol v, Scope s) { 385 for (Symbol sym : s.getSymbolsByName(v.name)) { 386 if (sym.owner != v.owner) break; 387 if (sym.kind == VAR && 388 sym.owner.kind.matches(KindSelector.VAL_MTH) && 389 v.name != names.error) { 390 duplicateError(pos, sym); 391 return; 392 } 393 } 394 } 395 396 /** Check that a class or interface does not hide a class or 397 * interface with same name in immediately enclosing local scope. 398 * @param pos Position for error reporting. 399 * @param c The symbol. 400 * @param s The scope. 401 */ 402 void checkTransparentClass(DiagnosticPosition pos, ClassSymbol c, Scope s) { 403 for (Symbol sym : s.getSymbolsByName(c.name)) { 404 if (sym.owner != c.owner) break; 405 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR) && 406 sym.owner.kind.matches(KindSelector.VAL_MTH) && 407 c.name != names.error) { 408 duplicateError(pos, sym); 409 return; 410 } 411 } 412 } 413 414 /** Check that class does not have the same name as one of 415 * its enclosing classes, or as a class defined in its enclosing scope. 416 * return true if class is unique in its enclosing scope. 417 * @param pos Position for error reporting. 418 * @param name The class name. 419 * @param s The enclosing scope. 420 */ 421 boolean checkUniqueClassName(DiagnosticPosition pos, Name name, Scope s) { 422 for (Symbol sym : s.getSymbolsByName(name, NON_RECURSIVE)) { 423 if (sym.kind == TYP && sym.name != names.error) { 424 duplicateError(pos, sym); 425 return false; 426 } 427 } 428 for (Symbol sym = s.owner; sym != null; sym = sym.owner) { 429 if (sym.kind == TYP && sym.name == name && sym.name != names.error && 430 !sym.isImplicit()) { 431 duplicateError(pos, sym); 432 return true; 433 } 434 } 435 return true; 436 } 437 438 /* ************************************************************************* 439 * Class name generation 440 **************************************************************************/ 441 442 443 private Map<Pair<Name, Name>, Integer> localClassNameIndexes = new HashMap<>(); 444 445 /** Return name of local class. 446 * This is of the form {@code <enclClass> $ n <classname> } 447 * where 448 * enclClass is the flat name of the enclosing class, 449 * classname is the simple name of the local class 450 */ 451 public Name localClassName(ClassSymbol c) { 452 Name enclFlatname = c.owner.enclClass().flatname; 453 String enclFlatnameStr = enclFlatname.toString(); 454 Pair<Name, Name> key = new Pair<>(enclFlatname, c.name); 455 Integer index = localClassNameIndexes.get(key); 456 for (int i = (index == null) ? 1 : index; ; i++) { 457 Name flatname = names.fromString(enclFlatnameStr 458 + syntheticNameChar + i + c.name); 459 if (getCompiled(c.packge().modle, flatname) == null) { 460 localClassNameIndexes.put(key, i + 1); 461 return flatname; 462 } 463 } 464 } 465 466 public void clearLocalClassNameIndexes(ClassSymbol c) { 467 if (c.owner != null && c.owner.kind != NIL) { 468 localClassNameIndexes.remove(new Pair<>( 469 c.owner.enclClass().flatname, c.name)); 470 } 471 } 472 473 public void newRound() { 474 compiled.clear(); 475 localClassNameIndexes.clear(); 476 } 477 478 public void clear() { 479 deprecationHandler.clear(); 480 removalHandler.clear(); 481 uncheckedHandler.clear(); 482 } 483 484 public void putCompiled(ClassSymbol csym) { 485 compiled.put(Pair.of(csym.packge().modle, csym.flatname), csym); 486 } 487 488 public ClassSymbol getCompiled(ClassSymbol csym) { 489 return compiled.get(Pair.of(csym.packge().modle, csym.flatname)); 490 } 491 492 public ClassSymbol getCompiled(ModuleSymbol msym, Name flatname) { 493 return compiled.get(Pair.of(msym, flatname)); 494 } 495 496 public void removeCompiled(ClassSymbol csym) { 497 compiled.remove(Pair.of(csym.packge().modle, csym.flatname)); 498 } 499 500 /* ************************************************************************* 501 * Type Checking 502 **************************************************************************/ 503 504 /** 505 * A check context is an object that can be used to perform compatibility 506 * checks - depending on the check context, meaning of 'compatibility' might 507 * vary significantly. 508 */ 509 public interface CheckContext { 510 /** 511 * Is type 'found' compatible with type 'req' in given context 512 */ 513 boolean compatible(Type found, Type req, Warner warn); 514 /** 515 * Report a check error 516 */ 517 void report(DiagnosticPosition pos, JCDiagnostic details); 518 /** 519 * Obtain a warner for this check context 520 */ 521 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req); 522 523 public InferenceContext inferenceContext(); 524 525 public DeferredAttr.DeferredAttrContext deferredAttrContext(); 526 } 527 528 /** 529 * This class represent a check context that is nested within another check 530 * context - useful to check sub-expressions. The default behavior simply 531 * redirects all method calls to the enclosing check context leveraging 532 * the forwarding pattern. 533 */ 534 static class NestedCheckContext implements CheckContext { 535 CheckContext enclosingContext; 536 537 NestedCheckContext(CheckContext enclosingContext) { 538 this.enclosingContext = enclosingContext; 539 } 540 541 public boolean compatible(Type found, Type req, Warner warn) { 542 return enclosingContext.compatible(found, req, warn); 543 } 544 545 public void report(DiagnosticPosition pos, JCDiagnostic details) { 546 enclosingContext.report(pos, details); 547 } 548 549 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) { 550 return enclosingContext.checkWarner(pos, found, req); 551 } 552 553 public InferenceContext inferenceContext() { 554 return enclosingContext.inferenceContext(); 555 } 556 557 public DeferredAttrContext deferredAttrContext() { 558 return enclosingContext.deferredAttrContext(); 559 } 560 } 561 562 /** 563 * Check context to be used when evaluating assignment/return statements 564 */ 565 CheckContext basicHandler = new CheckContext() { 566 public void report(DiagnosticPosition pos, JCDiagnostic details) { 567 log.error(pos, Errors.ProbFoundReq(details)); 568 } 569 public boolean compatible(Type found, Type req, Warner warn) { 570 return types.isAssignable(found, req, warn); 571 } 572 573 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) { 574 return convertWarner(pos, found, req); 575 } 576 577 public InferenceContext inferenceContext() { 578 return infer.emptyContext; 579 } 580 581 public DeferredAttrContext deferredAttrContext() { 582 return deferredAttr.emptyDeferredAttrContext; 583 } 584 585 @Override 586 public String toString() { 587 return "CheckContext: basicHandler"; 588 } 589 }; 590 591 /** Check that a given type is assignable to a given proto-type. 592 * If it is, return the type, otherwise return errType. 593 * @param pos Position to be used for error reporting. 594 * @param found The type that was found. 595 * @param req The type that was required. 596 */ 597 public Type checkType(DiagnosticPosition pos, Type found, Type req) { 598 return checkType(pos, found, req, basicHandler); 599 } 600 601 Type checkType(final DiagnosticPosition pos, final Type found, final Type req, final CheckContext checkContext) { 602 final InferenceContext inferenceContext = checkContext.inferenceContext(); 603 if (inferenceContext.free(req) || inferenceContext.free(found)) { 604 inferenceContext.addFreeTypeListener(List.of(req, found), 605 solvedContext -> checkType(pos, solvedContext.asInstType(found), solvedContext.asInstType(req), checkContext)); 606 } 607 if (req.hasTag(ERROR)) 608 return req; 609 if (req.hasTag(NONE)) 610 return found; 611 if (checkContext.compatible(found, req, checkContext.checkWarner(pos, found, req))) { 612 return found; 613 } else { 614 if (found.isNumeric() && req.isNumeric()) { 615 checkContext.report(pos, diags.fragment(Fragments.PossibleLossOfPrecision(found, req))); 616 return types.createErrorType(found); 617 } 618 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req))); 619 return types.createErrorType(found); 620 } 621 } 622 623 /** Check that a given type can be cast to a given target type. 624 * Return the result of the cast. 625 * @param pos Position to be used for error reporting. 626 * @param found The type that is being cast. 627 * @param req The target type of the cast. 628 */ 629 Type checkCastable(DiagnosticPosition pos, Type found, Type req) { 630 return checkCastable(pos, found, req, basicHandler); 631 } 632 Type checkCastable(DiagnosticPosition pos, Type found, Type req, CheckContext checkContext) { 633 if (types.isCastable(found, req, castWarner(pos, found, req))) { 634 return req; 635 } else { 636 checkContext.report(pos, diags.fragment(Fragments.InconvertibleTypes(found, req))); 637 return types.createErrorType(found); 638 } 639 } 640 641 /** Check for redundant casts (i.e. where source type is a subtype of target type) 642 * The problem should only be reported for non-292 cast 643 */ 644 public void checkRedundantCast(Env<AttrContext> env, final JCTypeCast tree) { 645 if (!tree.type.isErroneous() 646 && types.isSameType(tree.expr.type, tree.clazz.type) 647 && !(ignoreAnnotatedCasts && TreeInfo.containsTypeAnnotation(tree.clazz)) 648 && !is292targetTypeCast(tree)) { 649 deferredLintHandler.report(_l -> { 650 lint.logIfEnabled(tree.pos(), LintWarnings.RedundantCast(tree.clazz.type)); 651 }); 652 } 653 } 654 //where 655 private boolean is292targetTypeCast(JCTypeCast tree) { 656 boolean is292targetTypeCast = false; 657 JCExpression expr = TreeInfo.skipParens(tree.expr); 658 if (expr.hasTag(APPLY)) { 659 JCMethodInvocation apply = (JCMethodInvocation)expr; 660 Symbol sym = TreeInfo.symbol(apply.meth); 661 is292targetTypeCast = sym != null && 662 sym.kind == MTH && 663 (sym.flags() & HYPOTHETICAL) != 0; 664 } 665 return is292targetTypeCast; 666 } 667 668 private static final boolean ignoreAnnotatedCasts = true; 669 670 /** Check that a type is within some bounds. 671 * 672 * Used in TypeApply to verify that, e.g., X in {@code V<X>} is a valid 673 * type argument. 674 * @param a The type that should be bounded by bs. 675 * @param bound The bound. 676 */ 677 private boolean checkExtends(Type a, Type bound) { 678 if (a.isUnbound()) { 679 return true; 680 } else if (!a.hasTag(WILDCARD)) { 681 a = types.cvarUpperBound(a); 682 return types.isSubtype(a, bound); 683 } else if (a.isExtendsBound()) { 684 return types.isCastable(bound, types.wildUpperBound(a), types.noWarnings); 685 } else if (a.isSuperBound()) { 686 return !types.notSoftSubtype(types.wildLowerBound(a), bound); 687 } 688 return true; 689 } 690 691 /** Check that type is different from 'void'. 692 * @param pos Position to be used for error reporting. 693 * @param t The type to be checked. 694 */ 695 Type checkNonVoid(DiagnosticPosition pos, Type t) { 696 if (t.hasTag(VOID)) { 697 log.error(pos, Errors.VoidNotAllowedHere); 698 return types.createErrorType(t); 699 } else { 700 return t; 701 } 702 } 703 704 Type checkClassOrArrayType(DiagnosticPosition pos, Type t) { 705 if (!t.hasTag(CLASS) && !t.hasTag(ARRAY) && !t.hasTag(ERROR)) { 706 return typeTagError(pos, 707 diags.fragment(Fragments.TypeReqClassArray), 708 asTypeParam(t)); 709 } else { 710 return t; 711 } 712 } 713 714 /** Check that type is a class or interface type. 715 * @param pos Position to be used for error reporting. 716 * @param t The type to be checked. 717 */ 718 Type checkClassType(DiagnosticPosition pos, Type t) { 719 if (!t.hasTag(CLASS) && !t.hasTag(ERROR)) { 720 return typeTagError(pos, 721 diags.fragment(Fragments.TypeReqClass), 722 asTypeParam(t)); 723 } else { 724 return t; 725 } 726 } 727 //where 728 private Object asTypeParam(Type t) { 729 return (t.hasTag(TYPEVAR)) 730 ? diags.fragment(Fragments.TypeParameter(t)) 731 : t; 732 } 733 734 void checkConstraintsOfValueClass(JCClassDecl tree, ClassSymbol c) { 735 DiagnosticPosition pos = tree.pos(); 736 for (Type st : types.closure(c.type)) { 737 if (st == null || st.tsym == null || st.tsym.kind == ERR) 738 continue; 739 if (st.tsym == syms.objectType.tsym || st.tsym == syms.recordType.tsym || st.isInterface()) 740 continue; 741 if (!st.tsym.isAbstract()) { 742 if (c != st.tsym) { 743 log.error(pos, Errors.ConcreteSupertypeForValueClass(c, st)); 744 } 745 continue; 746 } 747 // dealing with an abstract value or value super class below. 748 for (Symbol s : st.tsym.members().getSymbols(NON_RECURSIVE)) { 749 if (s.kind == MTH) { 750 if ((s.flags() & (SYNCHRONIZED | STATIC)) == SYNCHRONIZED) { 751 log.error(pos, Errors.SuperClassMethodCannotBeSynchronized(s, c, st)); 752 } 753 break; 754 } 755 } 756 } 757 } 758 759 /** Check that type is a valid qualifier for a constructor reference expression 760 */ 761 Type checkConstructorRefType(DiagnosticPosition pos, Type t) { 762 t = checkClassOrArrayType(pos, t); 763 if (t.hasTag(CLASS)) { 764 if ((t.tsym.flags() & (ABSTRACT | INTERFACE)) != 0) { 765 log.error(pos, Errors.AbstractCantBeInstantiated(t.tsym)); 766 t = types.createErrorType(t); 767 } else if ((t.tsym.flags() & ENUM) != 0) { 768 log.error(pos, Errors.EnumCantBeInstantiated); 769 t = types.createErrorType(t); 770 } else { 771 t = checkClassType(pos, t, true); 772 } 773 } else if (t.hasTag(ARRAY)) { 774 if (!types.isReifiable(((ArrayType)t).elemtype)) { 775 log.error(pos, Errors.GenericArrayCreation); 776 t = types.createErrorType(t); 777 } 778 } 779 return t; 780 } 781 782 /** Check that type is a class or interface type. 783 * @param pos Position to be used for error reporting. 784 * @param t The type to be checked. 785 * @param noBounds True if type bounds are illegal here. 786 */ 787 Type checkClassType(DiagnosticPosition pos, Type t, boolean noBounds) { 788 t = checkClassType(pos, t); 789 if (noBounds && t.isParameterized()) { 790 List<Type> args = t.getTypeArguments(); 791 while (args.nonEmpty()) { 792 if (args.head.hasTag(WILDCARD)) 793 return typeTagError(pos, 794 diags.fragment(Fragments.TypeReqExact), 795 args.head); 796 args = args.tail; 797 } 798 } 799 return t; 800 } 801 802 /** Check that type is a reference type, i.e. a class, interface or array type 803 * or a type variable. 804 * @param pos Position to be used for error reporting. 805 * @param t The type to be checked. 806 */ 807 Type checkRefType(DiagnosticPosition pos, Type t) { 808 if (t.isReference()) 809 return t; 810 else 811 return typeTagError(pos, 812 diags.fragment(Fragments.TypeReqRef), 813 t); 814 } 815 816 /** Check that type is an identity type, i.e. not a value type. 817 * When not discernible statically, give it the benefit of doubt 818 * and defer to runtime. 819 * 820 * @param pos Position to be used for error reporting. 821 * @param t The type to be checked. 822 */ 823 boolean checkIdentityType(DiagnosticPosition pos, Type t) { 824 if (t.hasTag(TYPEVAR)) { 825 t = types.skipTypeVars(t, false); 826 } 827 if (t.isIntersection()) { 828 IntersectionClassType ict = (IntersectionClassType)t; 829 boolean result = true; 830 for (Type component : ict.getExplicitComponents()) { 831 result &= checkIdentityType(pos, component); 832 } 833 return result; 834 } 835 if (t.isPrimitive() || (t.isValueClass() && !t.tsym.isAbstract())) { 836 typeTagError(pos, diags.fragment(Fragments.TypeReqIdentity), t); 837 return false; 838 } 839 return true; 840 } 841 842 /** Check that each type is a reference type, i.e. a class, interface or array type 843 * or a type variable. 844 * @param trees Original trees, used for error reporting. 845 * @param types The types to be checked. 846 */ 847 List<Type> checkRefTypes(List<JCExpression> trees, List<Type> types) { 848 List<JCExpression> tl = trees; 849 for (List<Type> l = types; l.nonEmpty(); l = l.tail) { 850 l.head = checkRefType(tl.head.pos(), l.head); 851 tl = tl.tail; 852 } 853 return types; 854 } 855 856 /** Check that type is a null or reference type. 857 * @param pos Position to be used for error reporting. 858 * @param t The type to be checked. 859 */ 860 Type checkNullOrRefType(DiagnosticPosition pos, Type t) { 861 if (t.isReference() || t.hasTag(BOT)) 862 return t; 863 else 864 return typeTagError(pos, 865 diags.fragment(Fragments.TypeReqRef), 866 t); 867 } 868 869 /** Check that flag set does not contain elements of two conflicting sets. s 870 * Return true if it doesn't. 871 * @param pos Position to be used for error reporting. 872 * @param flags The set of flags to be checked. 873 * @param set1 Conflicting flags set #1. 874 * @param set2 Conflicting flags set #2. 875 */ 876 boolean checkDisjoint(DiagnosticPosition pos, long flags, long set1, long set2) { 877 if ((flags & set1) != 0 && (flags & set2) != 0) { 878 log.error(pos, 879 Errors.IllegalCombinationOfModifiers(asFlagSet(TreeInfo.firstFlag(flags & set1)), 880 asFlagSet(TreeInfo.firstFlag(flags & set2)))); 881 return false; 882 } else 883 return true; 884 } 885 886 /** Check that usage of diamond operator is correct (i.e. diamond should not 887 * be used with non-generic classes or in anonymous class creation expressions) 888 */ 889 Type checkDiamond(JCNewClass tree, Type t) { 890 if (!TreeInfo.isDiamond(tree) || 891 t.isErroneous()) { 892 return checkClassType(tree.clazz.pos(), t, true); 893 } else { 894 if (tree.def != null && !Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.allowedInSource(source)) { 895 log.error(DiagnosticFlag.SOURCE_LEVEL, tree.clazz.pos(), 896 Errors.CantApplyDiamond1(t, Feature.DIAMOND_WITH_ANONYMOUS_CLASS_CREATION.fragment(source.name))); 897 } 898 if (t.tsym.type.getTypeArguments().isEmpty()) { 899 log.error(tree.clazz.pos(), 900 Errors.CantApplyDiamond1(t, 901 Fragments.DiamondNonGeneric(t))); 902 return types.createErrorType(t); 903 } else if (tree.typeargs != null && 904 tree.typeargs.nonEmpty()) { 905 log.error(tree.clazz.pos(), 906 Errors.CantApplyDiamond1(t, 907 Fragments.DiamondAndExplicitParams(t))); 908 return types.createErrorType(t); 909 } else { 910 return t; 911 } 912 } 913 } 914 915 /** Check that the type inferred using the diamond operator does not contain 916 * non-denotable types such as captured types or intersection types. 917 * @param t the type inferred using the diamond operator 918 * @return the (possibly empty) list of non-denotable types. 919 */ 920 List<Type> checkDiamondDenotable(ClassType t) { 921 ListBuffer<Type> buf = new ListBuffer<>(); 922 for (Type arg : t.allparams()) { 923 if (!checkDenotable(arg)) { 924 buf.append(arg); 925 } 926 } 927 return buf.toList(); 928 } 929 930 public boolean checkDenotable(Type t) { 931 return denotableChecker.visit(t, null); 932 } 933 // where 934 935 /** diamondTypeChecker: A type visitor that descends down the given type looking for non-denotable 936 * types. The visit methods return false as soon as a non-denotable type is encountered and true 937 * otherwise. 938 */ 939 private static final Types.SimpleVisitor<Boolean, Void> denotableChecker = new Types.SimpleVisitor<Boolean, Void>() { 940 @Override 941 public Boolean visitType(Type t, Void s) { 942 return true; 943 } 944 @Override 945 public Boolean visitClassType(ClassType t, Void s) { 946 if (t.isUnion() || t.isIntersection()) { 947 return false; 948 } 949 for (Type targ : t.allparams()) { 950 if (!visit(targ, s)) { 951 return false; 952 } 953 } 954 return true; 955 } 956 957 @Override 958 public Boolean visitTypeVar(TypeVar t, Void s) { 959 /* Any type variable mentioned in the inferred type must have been declared as a type parameter 960 (i.e cannot have been produced by inference (18.4)) 961 */ 962 return (t.tsym.flags() & SYNTHETIC) == 0; 963 } 964 965 @Override 966 public Boolean visitCapturedType(CapturedType t, Void s) { 967 /* Any type variable mentioned in the inferred type must have been declared as a type parameter 968 (i.e cannot have been produced by capture conversion (5.1.10)) 969 */ 970 return false; 971 } 972 973 @Override 974 public Boolean visitArrayType(ArrayType t, Void s) { 975 return visit(t.elemtype, s); 976 } 977 978 @Override 979 public Boolean visitWildcardType(WildcardType t, Void s) { 980 return visit(t.type, s); 981 } 982 }; 983 984 void checkVarargsMethodDecl(Env<AttrContext> env, JCMethodDecl tree) { 985 MethodSymbol m = tree.sym; 986 boolean hasTrustMeAnno = m.attribute(syms.trustMeType.tsym) != null; 987 Type varargElemType = null; 988 if (m.isVarArgs()) { 989 varargElemType = types.elemtype(tree.params.last().type); 990 } 991 if (hasTrustMeAnno && !isTrustMeAllowedOnMethod(m)) { 992 if (varargElemType != null) { 993 JCDiagnostic msg = Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ? 994 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargs(m)) : 995 diags.fragment(Fragments.VarargsTrustmeOnVirtualVarargsFinalOnly(m)); 996 log.error(tree, 997 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym, 998 msg)); 999 } else { 1000 log.error(tree, 1001 Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym, 1002 Fragments.VarargsTrustmeOnNonVarargsMeth(m))); 1003 } 1004 } else if (hasTrustMeAnno && varargElemType != null && 1005 types.isReifiable(varargElemType)) { 1006 lint.logIfEnabled(tree, LintWarnings.VarargsRedundantTrustmeAnno( 1007 syms.trustMeType.tsym, 1008 diags.fragment(Fragments.VarargsTrustmeOnReifiableVarargs(varargElemType)))); 1009 } 1010 else if (!hasTrustMeAnno && varargElemType != null && 1011 !types.isReifiable(varargElemType)) { 1012 warnUnchecked(tree.params.head.pos(), LintWarnings.UncheckedVarargsNonReifiableType(varargElemType)); 1013 } 1014 } 1015 //where 1016 private boolean isTrustMeAllowedOnMethod(Symbol s) { 1017 return (s.flags() & VARARGS) != 0 && 1018 (s.isConstructor() || 1019 (s.flags() & (STATIC | FINAL | 1020 (Feature.PRIVATE_SAFE_VARARGS.allowedInSource(source) ? PRIVATE : 0) )) != 0); 1021 } 1022 1023 Type checkLocalVarType(DiagnosticPosition pos, Type t, Name name) { 1024 //check that resulting type is not the null type 1025 if (t.hasTag(BOT)) { 1026 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferNull)); 1027 return types.createErrorType(t); 1028 } else if (t.hasTag(VOID)) { 1029 log.error(pos, Errors.CantInferLocalVarType(name, Fragments.LocalCantInferVoid)); 1030 return types.createErrorType(t); 1031 } 1032 1033 //upward project the initializer type 1034 return types.upward(t, types.captures(t)).baseType(); 1035 } 1036 1037 Type checkMethod(final Type mtype, 1038 final Symbol sym, 1039 final Env<AttrContext> env, 1040 final List<JCExpression> argtrees, 1041 final List<Type> argtypes, 1042 final boolean useVarargs, 1043 InferenceContext inferenceContext) { 1044 // System.out.println("call : " + env.tree); 1045 // System.out.println("method : " + owntype); 1046 // System.out.println("actuals: " + argtypes); 1047 if (inferenceContext.free(mtype)) { 1048 inferenceContext.addFreeTypeListener(List.of(mtype), 1049 solvedContext -> checkMethod(solvedContext.asInstType(mtype), sym, env, argtrees, argtypes, useVarargs, solvedContext)); 1050 return mtype; 1051 } 1052 Type owntype = mtype; 1053 List<Type> formals = owntype.getParameterTypes(); 1054 List<Type> nonInferred = sym.type.getParameterTypes(); 1055 if (nonInferred.length() != formals.length()) nonInferred = formals; 1056 Type last = useVarargs ? formals.last() : null; 1057 if (sym.name == names.init && sym.owner == syms.enumSym) { 1058 formals = formals.tail.tail; 1059 nonInferred = nonInferred.tail.tail; 1060 } 1061 if ((sym.flags() & ANONCONSTR_BASED) != 0) { 1062 formals = formals.tail; 1063 nonInferred = nonInferred.tail; 1064 } 1065 List<JCExpression> args = argtrees; 1066 if (args != null) { 1067 //this is null when type-checking a method reference 1068 while (formals.head != last) { 1069 JCTree arg = args.head; 1070 Warner warn = convertWarner(arg.pos(), arg.type, nonInferred.head); 1071 assertConvertible(arg, arg.type, formals.head, warn); 1072 args = args.tail; 1073 formals = formals.tail; 1074 nonInferred = nonInferred.tail; 1075 } 1076 if (useVarargs) { 1077 Type varArg = types.elemtype(last); 1078 while (args.tail != null) { 1079 JCTree arg = args.head; 1080 Warner warn = convertWarner(arg.pos(), arg.type, varArg); 1081 assertConvertible(arg, arg.type, varArg, warn); 1082 args = args.tail; 1083 } 1084 } else if ((sym.flags() & (VARARGS | SIGNATURE_POLYMORPHIC)) == VARARGS) { 1085 // non-varargs call to varargs method 1086 Type varParam = owntype.getParameterTypes().last(); 1087 Type lastArg = argtypes.last(); 1088 if (types.isSubtypeUnchecked(lastArg, types.elemtype(varParam)) && 1089 !types.isSameType(types.erasure(varParam), types.erasure(lastArg))) 1090 log.warning(argtrees.last().pos(), 1091 Warnings.InexactNonVarargsCall(types.elemtype(varParam),varParam)); 1092 } 1093 } 1094 if (useVarargs) { 1095 Type argtype = owntype.getParameterTypes().last(); 1096 if (!types.isReifiable(argtype) && 1097 (sym.baseSymbol().attribute(syms.trustMeType.tsym) == null || 1098 !isTrustMeAllowedOnMethod(sym))) { 1099 warnUnchecked(env.tree.pos(), LintWarnings.UncheckedGenericArrayCreation(argtype)); 1100 } 1101 TreeInfo.setVarargsElement(env.tree, types.elemtype(argtype)); 1102 } 1103 return owntype; 1104 } 1105 //where 1106 private void assertConvertible(JCTree tree, Type actual, Type formal, Warner warn) { 1107 if (types.isConvertible(actual, formal, warn)) 1108 return; 1109 1110 if (formal.isCompound() 1111 && types.isSubtype(actual, types.supertype(formal)) 1112 && types.isSubtypeUnchecked(actual, types.interfaces(formal), warn)) 1113 return; 1114 } 1115 1116 /** 1117 * Check that type 't' is a valid instantiation of a generic class 1118 * (see JLS 4.5) 1119 * 1120 * @param t class type to be checked 1121 * @return true if 't' is well-formed 1122 */ 1123 public boolean checkValidGenericType(Type t) { 1124 return firstIncompatibleTypeArg(t) == null; 1125 } 1126 //WHERE 1127 private Type firstIncompatibleTypeArg(Type type) { 1128 List<Type> formals = type.tsym.type.allparams(); 1129 List<Type> actuals = type.allparams(); 1130 List<Type> args = type.getTypeArguments(); 1131 List<Type> forms = type.tsym.type.getTypeArguments(); 1132 ListBuffer<Type> bounds_buf = new ListBuffer<>(); 1133 1134 // For matching pairs of actual argument types `a' and 1135 // formal type parameters with declared bound `b' ... 1136 while (args.nonEmpty() && forms.nonEmpty()) { 1137 // exact type arguments needs to know their 1138 // bounds (for upper and lower bound 1139 // calculations). So we create new bounds where 1140 // type-parameters are replaced with actuals argument types. 1141 bounds_buf.append(types.subst(forms.head.getUpperBound(), formals, actuals)); 1142 args = args.tail; 1143 forms = forms.tail; 1144 } 1145 1146 args = type.getTypeArguments(); 1147 List<Type> tvars_cap = types.substBounds(formals, 1148 formals, 1149 types.capture(type).allparams()); 1150 while (args.nonEmpty() && tvars_cap.nonEmpty()) { 1151 // Let the actual arguments know their bound 1152 args.head.withTypeVar((TypeVar)tvars_cap.head); 1153 args = args.tail; 1154 tvars_cap = tvars_cap.tail; 1155 } 1156 1157 args = type.getTypeArguments(); 1158 List<Type> bounds = bounds_buf.toList(); 1159 1160 while (args.nonEmpty() && bounds.nonEmpty()) { 1161 Type actual = args.head; 1162 if (!isTypeArgErroneous(actual) && 1163 !bounds.head.isErroneous() && 1164 !checkExtends(actual, bounds.head)) { 1165 return args.head; 1166 } 1167 args = args.tail; 1168 bounds = bounds.tail; 1169 } 1170 1171 args = type.getTypeArguments(); 1172 bounds = bounds_buf.toList(); 1173 1174 for (Type arg : types.capture(type).getTypeArguments()) { 1175 if (arg.hasTag(TYPEVAR) && 1176 arg.getUpperBound().isErroneous() && 1177 !bounds.head.isErroneous() && 1178 !isTypeArgErroneous(args.head)) { 1179 return args.head; 1180 } 1181 bounds = bounds.tail; 1182 args = args.tail; 1183 } 1184 1185 return null; 1186 } 1187 //where 1188 boolean isTypeArgErroneous(Type t) { 1189 return isTypeArgErroneous.visit(t); 1190 } 1191 1192 Types.UnaryVisitor<Boolean> isTypeArgErroneous = new Types.UnaryVisitor<Boolean>() { 1193 public Boolean visitType(Type t, Void s) { 1194 return t.isErroneous(); 1195 } 1196 @Override 1197 public Boolean visitTypeVar(TypeVar t, Void s) { 1198 return visit(t.getUpperBound()); 1199 } 1200 @Override 1201 public Boolean visitCapturedType(CapturedType t, Void s) { 1202 return visit(t.getUpperBound()) || 1203 visit(t.getLowerBound()); 1204 } 1205 @Override 1206 public Boolean visitWildcardType(WildcardType t, Void s) { 1207 return visit(t.type); 1208 } 1209 }; 1210 1211 /** Check that given modifiers are legal for given symbol and 1212 * return modifiers together with any implicit modifiers for that symbol. 1213 * Warning: we can't use flags() here since this method 1214 * is called during class enter, when flags() would cause a premature 1215 * completion. 1216 * @param flags The set of modifiers given in a definition. 1217 * @param sym The defined symbol. 1218 * @param tree The declaration 1219 */ 1220 long checkFlags(long flags, Symbol sym, JCTree tree) { 1221 final DiagnosticPosition pos = tree.pos(); 1222 long mask; 1223 long implicit = 0; 1224 1225 switch (sym.kind) { 1226 case VAR: 1227 if (TreeInfo.isReceiverParam(tree)) 1228 mask = ReceiverParamFlags; 1229 else if (sym.owner.kind != TYP) 1230 mask = LocalVarFlags; 1231 else if ((sym.owner.flags_field & INTERFACE) != 0) 1232 mask = implicit = InterfaceVarFlags; 1233 else { 1234 boolean isInstanceFieldOfValueClass = sym.owner.type.isValueClass() && (flags & STATIC) == 0; 1235 mask = !isInstanceFieldOfValueClass ? VarFlags : ValueFieldFlags; 1236 if (isInstanceFieldOfValueClass) { 1237 implicit |= FINAL | STRICT; 1238 } 1239 } 1240 break; 1241 case MTH: 1242 if (sym.name == names.init) { 1243 if ((sym.owner.flags_field & ENUM) != 0) { 1244 // enum constructors cannot be declared public or 1245 // protected and must be implicitly or explicitly 1246 // private 1247 implicit = PRIVATE; 1248 mask = PRIVATE; 1249 } else 1250 mask = ConstructorFlags; 1251 } else if ((sym.owner.flags_field & INTERFACE) != 0) { 1252 if ((sym.owner.flags_field & ANNOTATION) != 0) { 1253 mask = AnnotationTypeElementMask; 1254 implicit = PUBLIC | ABSTRACT; 1255 } else if ((flags & (DEFAULT | STATIC | PRIVATE)) != 0) { 1256 mask = InterfaceMethodMask; 1257 implicit = (flags & PRIVATE) != 0 ? 0 : PUBLIC; 1258 if ((flags & DEFAULT) != 0) { 1259 implicit |= ABSTRACT; 1260 } 1261 } else { 1262 mask = implicit = InterfaceMethodFlags; 1263 } 1264 } else if ((sym.owner.flags_field & RECORD) != 0) { 1265 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ? 1266 RecordMethodFlags & ~SYNCHRONIZED : RecordMethodFlags; 1267 } else { 1268 // value objects do not have an associated monitor/lock 1269 mask = ((sym.owner.flags_field & VALUE_CLASS) != 0 && (flags & Flags.STATIC) == 0) ? 1270 MethodFlags & ~SYNCHRONIZED : MethodFlags; 1271 } 1272 if ((flags & STRICTFP) != 0) { 1273 warnOnExplicitStrictfp(tree); 1274 } 1275 // Imply STRICTFP if owner has STRICTFP set. 1276 if (((flags|implicit) & Flags.ABSTRACT) == 0 || 1277 ((flags) & Flags.DEFAULT) != 0) 1278 implicit |= sym.owner.flags_field & STRICTFP; 1279 break; 1280 case TYP: 1281 if (sym.owner.kind.matches(KindSelector.VAL_MTH) || 1282 (sym.isDirectlyOrIndirectlyLocal() && (flags & ANNOTATION) != 0)) { 1283 boolean implicitlyStatic = !sym.isAnonymous() && 1284 ((flags & RECORD) != 0 || (flags & ENUM) != 0 || (flags & INTERFACE) != 0); 1285 boolean staticOrImplicitlyStatic = (flags & STATIC) != 0 || implicitlyStatic; 1286 // local statics are allowed only if records are allowed too 1287 mask = staticOrImplicitlyStatic && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedStaticLocalClassFlags : ExtendedLocalClassFlags; 1288 implicit = implicitlyStatic ? STATIC : implicit; 1289 } else if (sym.owner.kind == TYP) { 1290 // statics in inner classes are allowed only if records are allowed too 1291 mask = ((flags & STATIC) != 0) && allowRecords && (flags & ANNOTATION) == 0 ? ExtendedMemberStaticClassFlags : ExtendedMemberClassFlags; 1292 if (sym.owner.owner.kind == PCK || 1293 (sym.owner.flags_field & STATIC) != 0) { 1294 mask |= STATIC; 1295 } else if (!allowRecords && ((flags & ENUM) != 0 || (flags & RECORD) != 0)) { 1296 log.error(pos, Errors.StaticDeclarationNotAllowedInInnerClasses); 1297 } 1298 // Nested interfaces and enums are always STATIC (Spec ???) 1299 if ((flags & (INTERFACE | ENUM | RECORD)) != 0 ) implicit = STATIC; 1300 } else { 1301 mask = ExtendedClassFlags; 1302 } 1303 if ((flags & (VALUE_CLASS | SEALED | ABSTRACT)) == (VALUE_CLASS | SEALED) || 1304 (flags & (VALUE_CLASS | NON_SEALED | ABSTRACT)) == (VALUE_CLASS | NON_SEALED)) { 1305 log.error(pos, Errors.NonAbstractValueClassCantBeSealedOrNonSealed); 1306 } 1307 // Interfaces are always ABSTRACT 1308 if ((flags & INTERFACE) != 0) implicit |= ABSTRACT; 1309 1310 if ((flags & (INTERFACE | VALUE_CLASS)) == 0) { 1311 implicit |= IDENTITY_TYPE; 1312 } 1313 1314 if ((flags & ENUM) != 0) { 1315 // enums can't be declared abstract, final, sealed or non-sealed or value 1316 mask &= ~(ABSTRACT | FINAL | SEALED | NON_SEALED | VALUE_CLASS); 1317 implicit |= implicitEnumFinalFlag(tree); 1318 } 1319 if ((flags & RECORD) != 0) { 1320 // records can't be declared abstract 1321 mask &= ~ABSTRACT; 1322 implicit |= FINAL; 1323 } 1324 if ((flags & STRICTFP) != 0) { 1325 warnOnExplicitStrictfp(tree); 1326 } 1327 // Imply STRICTFP if owner has STRICTFP set. 1328 implicit |= sym.owner.flags_field & STRICTFP; 1329 1330 // concrete value classes are implicitly final 1331 if ((flags & (ABSTRACT | INTERFACE | VALUE_CLASS)) == VALUE_CLASS) { 1332 implicit |= FINAL; 1333 } 1334 break; 1335 default: 1336 throw new AssertionError(); 1337 } 1338 long illegal = flags & ExtendedStandardFlags & ~mask; 1339 if (illegal != 0) { 1340 if ((illegal & INTERFACE) != 0) { 1341 log.error(pos, ((flags & ANNOTATION) != 0) ? Errors.AnnotationDeclNotAllowedHere : Errors.IntfNotAllowedHere); 1342 mask |= INTERFACE; 1343 } 1344 else { 1345 log.error(pos, 1346 Errors.ModNotAllowedHere(asFlagSet(illegal))); 1347 } 1348 } else if ((sym.kind == TYP || 1349 // ISSUE: Disallowing abstract&private is no longer appropriate 1350 // in the presence of inner classes. Should it be deleted here? 1351 checkDisjoint(pos, flags, 1352 ABSTRACT, 1353 PRIVATE | STATIC | DEFAULT)) 1354 && 1355 checkDisjoint(pos, flags, 1356 STATIC | PRIVATE, 1357 DEFAULT) 1358 && 1359 checkDisjoint(pos, flags, 1360 ABSTRACT | INTERFACE, 1361 FINAL | NATIVE | SYNCHRONIZED) 1362 && 1363 checkDisjoint(pos, flags, 1364 PUBLIC, 1365 PRIVATE | PROTECTED) 1366 && 1367 checkDisjoint(pos, flags, 1368 PRIVATE, 1369 PUBLIC | PROTECTED) 1370 && 1371 // we are using `implicit` here as instance fields of value classes are implicitly final 1372 checkDisjoint(pos, flags | implicit, 1373 FINAL, 1374 VOLATILE) 1375 && 1376 (sym.kind == TYP || 1377 checkDisjoint(pos, flags, 1378 ABSTRACT | NATIVE, 1379 STRICTFP)) 1380 && checkDisjoint(pos, flags, 1381 FINAL, 1382 SEALED | NON_SEALED) 1383 && checkDisjoint(pos, flags, 1384 SEALED, 1385 FINAL | NON_SEALED) 1386 && checkDisjoint(pos, flags, 1387 SEALED, 1388 ANNOTATION) 1389 && checkDisjoint(pos, flags, 1390 VALUE_CLASS, 1391 ANNOTATION) 1392 && checkDisjoint(pos, flags, 1393 VALUE_CLASS, 1394 INTERFACE) ) { 1395 // skip 1396 } 1397 return flags & (mask | ~ExtendedStandardFlags) | implicit; 1398 } 1399 1400 private void warnOnExplicitStrictfp(JCTree tree) { 1401 deferredLintHandler.push(tree); 1402 try { 1403 deferredLintHandler.report(_ -> lint.logIfEnabled(tree.pos(), LintWarnings.Strictfp)); 1404 } finally { 1405 deferredLintHandler.pop(); 1406 } 1407 } 1408 1409 1410 /** Determine if this enum should be implicitly final. 1411 * 1412 * If the enum has no specialized enum constants, it is final. 1413 * 1414 * If the enum does have specialized enum constants, it is 1415 * <i>not</i> final. 1416 */ 1417 private long implicitEnumFinalFlag(JCTree tree) { 1418 if (!tree.hasTag(CLASSDEF)) return 0; 1419 class SpecialTreeVisitor extends JCTree.Visitor { 1420 boolean specialized; 1421 SpecialTreeVisitor() { 1422 this.specialized = false; 1423 } 1424 1425 @Override 1426 public void visitTree(JCTree tree) { /* no-op */ } 1427 1428 @Override 1429 public void visitVarDef(JCVariableDecl tree) { 1430 if ((tree.mods.flags & ENUM) != 0) { 1431 if (tree.init instanceof JCNewClass newClass && newClass.def != null) { 1432 specialized = true; 1433 } 1434 } 1435 } 1436 } 1437 1438 SpecialTreeVisitor sts = new SpecialTreeVisitor(); 1439 JCClassDecl cdef = (JCClassDecl) tree; 1440 for (JCTree defs: cdef.defs) { 1441 defs.accept(sts); 1442 if (sts.specialized) return allowSealed ? SEALED : 0; 1443 } 1444 return FINAL; 1445 } 1446 1447 /* ************************************************************************* 1448 * Type Validation 1449 **************************************************************************/ 1450 1451 /** Validate a type expression. That is, 1452 * check that all type arguments of a parametric type are within 1453 * their bounds. This must be done in a second phase after type attribution 1454 * since a class might have a subclass as type parameter bound. E.g: 1455 * 1456 * <pre>{@code 1457 * class B<A extends C> { ... } 1458 * class C extends B<C> { ... } 1459 * }</pre> 1460 * 1461 * and we can't make sure that the bound is already attributed because 1462 * of possible cycles. 1463 * 1464 * Visitor method: Validate a type expression, if it is not null, catching 1465 * and reporting any completion failures. 1466 */ 1467 void validate(JCTree tree, Env<AttrContext> env) { 1468 validate(tree, env, true); 1469 } 1470 void validate(JCTree tree, Env<AttrContext> env, boolean checkRaw) { 1471 new Validator(env).validateTree(tree, checkRaw, true); 1472 } 1473 1474 /** Visitor method: Validate a list of type expressions. 1475 */ 1476 void validate(List<? extends JCTree> trees, Env<AttrContext> env) { 1477 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 1478 validate(l.head, env); 1479 } 1480 1481 /** A visitor class for type validation. 1482 */ 1483 class Validator extends JCTree.Visitor { 1484 1485 boolean checkRaw; 1486 boolean isOuter; 1487 Env<AttrContext> env; 1488 1489 Validator(Env<AttrContext> env) { 1490 this.env = env; 1491 } 1492 1493 @Override 1494 public void visitTypeArray(JCArrayTypeTree tree) { 1495 validateTree(tree.elemtype, checkRaw, isOuter); 1496 } 1497 1498 @Override 1499 public void visitTypeApply(JCTypeApply tree) { 1500 if (tree.type.hasTag(CLASS)) { 1501 List<JCExpression> args = tree.arguments; 1502 List<Type> forms = tree.type.tsym.type.getTypeArguments(); 1503 1504 Type incompatibleArg = firstIncompatibleTypeArg(tree.type); 1505 if (incompatibleArg != null) { 1506 for (JCTree arg : tree.arguments) { 1507 if (arg.type == incompatibleArg) { 1508 log.error(arg, Errors.NotWithinBounds(incompatibleArg, forms.head)); 1509 } 1510 forms = forms.tail; 1511 } 1512 } 1513 1514 forms = tree.type.tsym.type.getTypeArguments(); 1515 1516 boolean is_java_lang_Class = tree.type.tsym.flatName() == names.java_lang_Class; 1517 1518 // For matching pairs of actual argument types `a' and 1519 // formal type parameters with declared bound `b' ... 1520 while (args.nonEmpty() && forms.nonEmpty()) { 1521 validateTree(args.head, 1522 !(isOuter && is_java_lang_Class), 1523 false); 1524 args = args.tail; 1525 forms = forms.tail; 1526 } 1527 1528 // Check that this type is either fully parameterized, or 1529 // not parameterized at all. 1530 if (tree.type.getEnclosingType().isRaw()) 1531 log.error(tree.pos(), Errors.ImproperlyFormedTypeInnerRawParam); 1532 if (tree.clazz.hasTag(SELECT)) 1533 visitSelectInternal((JCFieldAccess)tree.clazz); 1534 } 1535 } 1536 1537 @Override 1538 public void visitTypeParameter(JCTypeParameter tree) { 1539 validateTrees(tree.bounds, true, isOuter); 1540 checkClassBounds(tree.pos(), tree.type); 1541 } 1542 1543 @Override 1544 public void visitWildcard(JCWildcard tree) { 1545 if (tree.inner != null) 1546 validateTree(tree.inner, true, isOuter); 1547 } 1548 1549 @Override 1550 public void visitSelect(JCFieldAccess tree) { 1551 if (tree.type.hasTag(CLASS)) { 1552 visitSelectInternal(tree); 1553 1554 // Check that this type is either fully parameterized, or 1555 // not parameterized at all. 1556 if (tree.selected.type.isParameterized() && tree.type.tsym.type.getTypeArguments().nonEmpty()) 1557 log.error(tree.pos(), Errors.ImproperlyFormedTypeParamMissing); 1558 } 1559 } 1560 1561 public void visitSelectInternal(JCFieldAccess tree) { 1562 if (tree.type.tsym.isStatic() && 1563 tree.selected.type.isParameterized()) { 1564 // The enclosing type is not a class, so we are 1565 // looking at a static member type. However, the 1566 // qualifying expression is parameterized. 1567 log.error(tree.pos(), Errors.CantSelectStaticClassFromParamType); 1568 } else { 1569 // otherwise validate the rest of the expression 1570 tree.selected.accept(this); 1571 } 1572 } 1573 1574 @Override 1575 public void visitAnnotatedType(JCAnnotatedType tree) { 1576 tree.underlyingType.accept(this); 1577 } 1578 1579 @Override 1580 public void visitTypeIdent(JCPrimitiveTypeTree that) { 1581 if (that.type.hasTag(TypeTag.VOID)) { 1582 log.error(that.pos(), Errors.VoidNotAllowedHere); 1583 } 1584 super.visitTypeIdent(that); 1585 } 1586 1587 /** Default visitor method: do nothing. 1588 */ 1589 @Override 1590 public void visitTree(JCTree tree) { 1591 } 1592 1593 public void validateTree(JCTree tree, boolean checkRaw, boolean isOuter) { 1594 if (tree != null) { 1595 boolean prevCheckRaw = this.checkRaw; 1596 this.checkRaw = checkRaw; 1597 this.isOuter = isOuter; 1598 1599 try { 1600 tree.accept(this); 1601 if (checkRaw) 1602 checkRaw(tree, env); 1603 } catch (CompletionFailure ex) { 1604 completionError(tree.pos(), ex); 1605 } finally { 1606 this.checkRaw = prevCheckRaw; 1607 } 1608 } 1609 } 1610 1611 public void validateTrees(List<? extends JCTree> trees, boolean checkRaw, boolean isOuter) { 1612 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail) 1613 validateTree(l.head, checkRaw, isOuter); 1614 } 1615 } 1616 1617 void checkRaw(JCTree tree, Env<AttrContext> env) { 1618 if (tree.type.hasTag(CLASS) && 1619 !TreeInfo.isDiamond(tree) && 1620 !withinAnonConstr(env) && 1621 tree.type.isRaw()) { 1622 lint.logIfEnabled(tree.pos(), LintWarnings.RawClassUse(tree.type, tree.type.tsym.type)); 1623 } 1624 } 1625 //where 1626 private boolean withinAnonConstr(Env<AttrContext> env) { 1627 return env.enclClass.name.isEmpty() && 1628 env.enclMethod != null && env.enclMethod.name == names.init; 1629 } 1630 1631 /* ************************************************************************* 1632 * Exception checking 1633 **************************************************************************/ 1634 1635 /* The following methods treat classes as sets that contain 1636 * the class itself and all their subclasses 1637 */ 1638 1639 /** Is given type a subtype of some of the types in given list? 1640 */ 1641 boolean subset(Type t, List<Type> ts) { 1642 for (List<Type> l = ts; l.nonEmpty(); l = l.tail) 1643 if (types.isSubtype(t, l.head)) return true; 1644 return false; 1645 } 1646 1647 /** Is given type a subtype or supertype of 1648 * some of the types in given list? 1649 */ 1650 boolean intersects(Type t, List<Type> ts) { 1651 for (List<Type> l = ts; l.nonEmpty(); l = l.tail) 1652 if (types.isSubtype(t, l.head) || types.isSubtype(l.head, t)) return true; 1653 return false; 1654 } 1655 1656 /** Add type set to given type list, unless it is a subclass of some class 1657 * in the list. 1658 */ 1659 List<Type> incl(Type t, List<Type> ts) { 1660 return subset(t, ts) ? ts : excl(t, ts).prepend(t); 1661 } 1662 1663 /** Remove type set from type set list. 1664 */ 1665 List<Type> excl(Type t, List<Type> ts) { 1666 if (ts.isEmpty()) { 1667 return ts; 1668 } else { 1669 List<Type> ts1 = excl(t, ts.tail); 1670 if (types.isSubtype(ts.head, t)) return ts1; 1671 else if (ts1 == ts.tail) return ts; 1672 else return ts1.prepend(ts.head); 1673 } 1674 } 1675 1676 /** Form the union of two type set lists. 1677 */ 1678 List<Type> union(List<Type> ts1, List<Type> ts2) { 1679 List<Type> ts = ts1; 1680 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail) 1681 ts = incl(l.head, ts); 1682 return ts; 1683 } 1684 1685 /** Form the difference of two type lists. 1686 */ 1687 List<Type> diff(List<Type> ts1, List<Type> ts2) { 1688 List<Type> ts = ts1; 1689 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail) 1690 ts = excl(l.head, ts); 1691 return ts; 1692 } 1693 1694 /** Form the intersection of two type lists. 1695 */ 1696 public List<Type> intersect(List<Type> ts1, List<Type> ts2) { 1697 List<Type> ts = List.nil(); 1698 for (List<Type> l = ts1; l.nonEmpty(); l = l.tail) 1699 if (subset(l.head, ts2)) ts = incl(l.head, ts); 1700 for (List<Type> l = ts2; l.nonEmpty(); l = l.tail) 1701 if (subset(l.head, ts1)) ts = incl(l.head, ts); 1702 return ts; 1703 } 1704 1705 /** Is exc an exception symbol that need not be declared? 1706 */ 1707 boolean isUnchecked(ClassSymbol exc) { 1708 return 1709 exc.kind == ERR || 1710 exc.isSubClass(syms.errorType.tsym, types) || 1711 exc.isSubClass(syms.runtimeExceptionType.tsym, types); 1712 } 1713 1714 /** Is exc an exception type that need not be declared? 1715 */ 1716 boolean isUnchecked(Type exc) { 1717 return 1718 (exc.hasTag(TYPEVAR)) ? isUnchecked(types.supertype(exc)) : 1719 (exc.hasTag(CLASS)) ? isUnchecked((ClassSymbol)exc.tsym) : 1720 exc.hasTag(BOT); 1721 } 1722 1723 boolean isChecked(Type exc) { 1724 return !isUnchecked(exc); 1725 } 1726 1727 /** Same, but handling completion failures. 1728 */ 1729 boolean isUnchecked(DiagnosticPosition pos, Type exc) { 1730 try { 1731 return isUnchecked(exc); 1732 } catch (CompletionFailure ex) { 1733 completionError(pos, ex); 1734 return true; 1735 } 1736 } 1737 1738 /** Is exc handled by given exception list? 1739 */ 1740 boolean isHandled(Type exc, List<Type> handled) { 1741 return isUnchecked(exc) || subset(exc, handled); 1742 } 1743 1744 /** Return all exceptions in thrown list that are not in handled list. 1745 * @param thrown The list of thrown exceptions. 1746 * @param handled The list of handled exceptions. 1747 */ 1748 List<Type> unhandled(List<Type> thrown, List<Type> handled) { 1749 List<Type> unhandled = List.nil(); 1750 for (List<Type> l = thrown; l.nonEmpty(); l = l.tail) 1751 if (!isHandled(l.head, handled)) unhandled = unhandled.prepend(l.head); 1752 return unhandled; 1753 } 1754 1755 /* ************************************************************************* 1756 * Overriding/Implementation checking 1757 **************************************************************************/ 1758 1759 /** The level of access protection given by a flag set, 1760 * where PRIVATE is highest and PUBLIC is lowest. 1761 */ 1762 static int protection(long flags) { 1763 switch ((short)(flags & AccessFlags)) { 1764 case PRIVATE: return 3; 1765 case PROTECTED: return 1; 1766 default: 1767 case PUBLIC: return 0; 1768 case 0: return 2; 1769 } 1770 } 1771 1772 /** A customized "cannot override" error message. 1773 * @param m The overriding method. 1774 * @param other The overridden method. 1775 * @return An internationalized string. 1776 */ 1777 Fragment cannotOverride(MethodSymbol m, MethodSymbol other) { 1778 Symbol mloc = m.location(); 1779 Symbol oloc = other.location(); 1780 1781 if ((other.owner.flags() & INTERFACE) == 0) 1782 return Fragments.CantOverride(m, mloc, other, oloc); 1783 else if ((m.owner.flags() & INTERFACE) == 0) 1784 return Fragments.CantImplement(m, mloc, other, oloc); 1785 else 1786 return Fragments.ClashesWith(m, mloc, other, oloc); 1787 } 1788 1789 /** A customized "override" warning message. 1790 * @param m The overriding method. 1791 * @param other The overridden method. 1792 * @return An internationalized string. 1793 */ 1794 Fragment uncheckedOverrides(MethodSymbol m, MethodSymbol other) { 1795 Symbol mloc = m.location(); 1796 Symbol oloc = other.location(); 1797 1798 if ((other.owner.flags() & INTERFACE) == 0) 1799 return Fragments.UncheckedOverride(m, mloc, other, oloc); 1800 else if ((m.owner.flags() & INTERFACE) == 0) 1801 return Fragments.UncheckedImplement(m, mloc, other, oloc); 1802 else 1803 return Fragments.UncheckedClashWith(m, mloc, other, oloc); 1804 } 1805 1806 /** A customized "override" warning message. 1807 * @param m The overriding method. 1808 * @param other The overridden method. 1809 * @return An internationalized string. 1810 */ 1811 Fragment varargsOverrides(MethodSymbol m, MethodSymbol other) { 1812 Symbol mloc = m.location(); 1813 Symbol oloc = other.location(); 1814 1815 if ((other.owner.flags() & INTERFACE) == 0) 1816 return Fragments.VarargsOverride(m, mloc, other, oloc); 1817 else if ((m.owner.flags() & INTERFACE) == 0) 1818 return Fragments.VarargsImplement(m, mloc, other, oloc); 1819 else 1820 return Fragments.VarargsClashWith(m, mloc, other, oloc); 1821 } 1822 1823 /** Check that this method conforms with overridden method 'other'. 1824 * where `origin' is the class where checking started. 1825 * Complications: 1826 * (1) Do not check overriding of synthetic methods 1827 * (reason: they might be final). 1828 * todo: check whether this is still necessary. 1829 * (2) Admit the case where an interface proxy throws fewer exceptions 1830 * than the method it implements. Augment the proxy methods with the 1831 * undeclared exceptions in this case. 1832 * (3) When generics are enabled, admit the case where an interface proxy 1833 * has a result type 1834 * extended by the result type of the method it implements. 1835 * Change the proxies result type to the smaller type in this case. 1836 * 1837 * @param tree The tree from which positions 1838 * are extracted for errors. 1839 * @param m The overriding method. 1840 * @param other The overridden method. 1841 * @param origin The class of which the overriding method 1842 * is a member. 1843 */ 1844 void checkOverride(JCTree tree, 1845 MethodSymbol m, 1846 MethodSymbol other, 1847 ClassSymbol origin) { 1848 // Don't check overriding of synthetic methods or by bridge methods. 1849 if ((m.flags() & (SYNTHETIC|BRIDGE)) != 0 || (other.flags() & SYNTHETIC) != 0) { 1850 return; 1851 } 1852 1853 // Error if static method overrides instance method (JLS 8.4.8.2). 1854 if ((m.flags() & STATIC) != 0 && 1855 (other.flags() & STATIC) == 0) { 1856 log.error(TreeInfo.diagnosticPositionFor(m, tree), 1857 Errors.OverrideStatic(cannotOverride(m, other))); 1858 m.flags_field |= BAD_OVERRIDE; 1859 return; 1860 } 1861 1862 // Error if instance method overrides static or final 1863 // method (JLS 8.4.8.1). 1864 if ((other.flags() & FINAL) != 0 || 1865 (m.flags() & STATIC) == 0 && 1866 (other.flags() & STATIC) != 0) { 1867 log.error(TreeInfo.diagnosticPositionFor(m, tree), 1868 Errors.OverrideMeth(cannotOverride(m, other), 1869 asFlagSet(other.flags() & (FINAL | STATIC)))); 1870 m.flags_field |= BAD_OVERRIDE; 1871 return; 1872 } 1873 1874 if ((m.owner.flags() & ANNOTATION) != 0) { 1875 // handled in validateAnnotationMethod 1876 return; 1877 } 1878 1879 // Error if overriding method has weaker access (JLS 8.4.8.3). 1880 if (protection(m.flags()) > protection(other.flags())) { 1881 log.error(TreeInfo.diagnosticPositionFor(m, tree), 1882 (other.flags() & AccessFlags) == 0 ? 1883 Errors.OverrideWeakerAccess(cannotOverride(m, other), 1884 "package") : 1885 Errors.OverrideWeakerAccess(cannotOverride(m, other), 1886 asFlagSet(other.flags() & AccessFlags))); 1887 m.flags_field |= BAD_OVERRIDE; 1888 return; 1889 } 1890 1891 if (shouldCheckPreview(m, other, origin)) { 1892 checkPreview(TreeInfo.diagnosticPositionFor(m, tree), 1893 m, origin.type, other); 1894 } 1895 1896 Type mt = types.memberType(origin.type, m); 1897 Type ot = types.memberType(origin.type, other); 1898 // Error if overriding result type is different 1899 // (or, in the case of generics mode, not a subtype) of 1900 // overridden result type. We have to rename any type parameters 1901 // before comparing types. 1902 List<Type> mtvars = mt.getTypeArguments(); 1903 List<Type> otvars = ot.getTypeArguments(); 1904 Type mtres = mt.getReturnType(); 1905 Type otres = types.subst(ot.getReturnType(), otvars, mtvars); 1906 1907 overrideWarner.clear(); 1908 boolean resultTypesOK = 1909 types.returnTypeSubstitutable(mt, ot, otres, overrideWarner); 1910 if (!resultTypesOK) { 1911 if ((m.flags() & STATIC) != 0 && (other.flags() & STATIC) != 0) { 1912 log.error(TreeInfo.diagnosticPositionFor(m, tree), 1913 Errors.OverrideIncompatibleRet(Fragments.CantHide(m, m.location(), other, 1914 other.location()), mtres, otres)); 1915 m.flags_field |= BAD_OVERRIDE; 1916 } else { 1917 log.error(TreeInfo.diagnosticPositionFor(m, tree), 1918 Errors.OverrideIncompatibleRet(cannotOverride(m, other), mtres, otres)); 1919 m.flags_field |= BAD_OVERRIDE; 1920 } 1921 return; 1922 } else if (overrideWarner.hasNonSilentLint(LintCategory.UNCHECKED)) { 1923 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree), 1924 LintWarnings.OverrideUncheckedRet(uncheckedOverrides(m, other), mtres, otres)); 1925 } 1926 1927 // Error if overriding method throws an exception not reported 1928 // by overridden method. 1929 List<Type> otthrown = types.subst(ot.getThrownTypes(), otvars, mtvars); 1930 List<Type> unhandledErased = unhandled(mt.getThrownTypes(), types.erasure(otthrown)); 1931 List<Type> unhandledUnerased = unhandled(mt.getThrownTypes(), otthrown); 1932 if (unhandledErased.nonEmpty()) { 1933 log.error(TreeInfo.diagnosticPositionFor(m, tree), 1934 Errors.OverrideMethDoesntThrow(cannotOverride(m, other), unhandledUnerased.head)); 1935 m.flags_field |= BAD_OVERRIDE; 1936 return; 1937 } 1938 else if (unhandledUnerased.nonEmpty()) { 1939 warnUnchecked(TreeInfo.diagnosticPositionFor(m, tree), 1940 LintWarnings.OverrideUncheckedThrown(cannotOverride(m, other), unhandledUnerased.head)); 1941 return; 1942 } 1943 1944 // Optional warning if varargs don't agree 1945 if ((((m.flags() ^ other.flags()) & Flags.VARARGS) != 0)) { 1946 lint.logIfEnabled(TreeInfo.diagnosticPositionFor(m, tree), 1947 ((m.flags() & Flags.VARARGS) != 0) 1948 ? LintWarnings.OverrideVarargsMissing(varargsOverrides(m, other)) 1949 : LintWarnings.OverrideVarargsExtra(varargsOverrides(m, other))); 1950 } 1951 1952 // Warn if instance method overrides bridge method (compiler spec ??) 1953 if ((other.flags() & BRIDGE) != 0) { 1954 log.warning(TreeInfo.diagnosticPositionFor(m, tree), 1955 Warnings.OverrideBridge(uncheckedOverrides(m, other))); 1956 } 1957 1958 // Warn if a deprecated method overridden by a non-deprecated one. 1959 if (!isDeprecatedOverrideIgnorable(other, origin)) { 1960 Lint prevLint = setLint(lint.augment(m)); 1961 try { 1962 checkDeprecated(() -> TreeInfo.diagnosticPositionFor(m, tree), m, other); 1963 } finally { 1964 setLint(prevLint); 1965 } 1966 } 1967 } 1968 // where 1969 private boolean shouldCheckPreview(MethodSymbol m, MethodSymbol other, ClassSymbol origin) { 1970 if (m.owner != origin || 1971 //performance - only do the expensive checks when the overridden method is a Preview API: 1972 ((other.flags() & PREVIEW_API) == 0 && 1973 (other.owner.flags() & PREVIEW_API) == 0)) { 1974 return false; 1975 } 1976 1977 for (Symbol s : types.membersClosure(origin.type, false).getSymbolsByName(m.name)) { 1978 if (m != s && m.overrides(s, origin, types, false)) { 1979 //only produce preview warnings or errors if "m" immediatelly overrides "other" 1980 //without intermediate overriding methods: 1981 return s == other; 1982 } 1983 } 1984 1985 return false; 1986 } 1987 private boolean isDeprecatedOverrideIgnorable(MethodSymbol m, ClassSymbol origin) { 1988 // If the method, m, is defined in an interface, then ignore the issue if the method 1989 // is only inherited via a supertype and also implemented in the supertype, 1990 // because in that case, we will rediscover the issue when examining the method 1991 // in the supertype. 1992 // If the method, m, is not defined in an interface, then the only time we need to 1993 // address the issue is when the method is the supertype implementation: any other 1994 // case, we will have dealt with when examining the supertype classes 1995 ClassSymbol mc = m.enclClass(); 1996 Type st = types.supertype(origin.type); 1997 if (!st.hasTag(CLASS)) 1998 return true; 1999 MethodSymbol stimpl = m.implementation((ClassSymbol)st.tsym, types, false); 2000 2001 if (mc != null && ((mc.flags() & INTERFACE) != 0)) { 2002 List<Type> intfs = types.interfaces(origin.type); 2003 return (intfs.contains(mc.type) ? false : (stimpl != null)); 2004 } 2005 else 2006 return (stimpl != m); 2007 } 2008 2009 2010 // used to check if there were any unchecked conversions 2011 Warner overrideWarner = new Warner(); 2012 2013 /** Check that a class does not inherit two concrete methods 2014 * with the same signature. 2015 * @param pos Position to be used for error reporting. 2016 * @param site The class type to be checked. 2017 */ 2018 public void checkCompatibleConcretes(DiagnosticPosition pos, Type site) { 2019 Type sup = types.supertype(site); 2020 if (!sup.hasTag(CLASS)) return; 2021 2022 for (Type t1 = sup; 2023 t1.hasTag(CLASS) && t1.tsym.type.isParameterized(); 2024 t1 = types.supertype(t1)) { 2025 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) { 2026 if (s1.kind != MTH || 2027 (s1.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 || 2028 !s1.isInheritedIn(site.tsym, types) || 2029 ((MethodSymbol)s1).implementation(site.tsym, 2030 types, 2031 true) != s1) 2032 continue; 2033 Type st1 = types.memberType(t1, s1); 2034 int s1ArgsLength = st1.getParameterTypes().length(); 2035 if (st1 == s1.type) continue; 2036 2037 for (Type t2 = sup; 2038 t2.hasTag(CLASS); 2039 t2 = types.supertype(t2)) { 2040 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) { 2041 if (s2 == s1 || 2042 s2.kind != MTH || 2043 (s2.flags() & (STATIC|SYNTHETIC|BRIDGE)) != 0 || 2044 s2.type.getParameterTypes().length() != s1ArgsLength || 2045 !s2.isInheritedIn(site.tsym, types) || 2046 ((MethodSymbol)s2).implementation(site.tsym, 2047 types, 2048 true) != s2) 2049 continue; 2050 Type st2 = types.memberType(t2, s2); 2051 if (types.overrideEquivalent(st1, st2)) 2052 log.error(pos, 2053 Errors.ConcreteInheritanceConflict(s1, t1, s2, t2, sup)); 2054 } 2055 } 2056 } 2057 } 2058 } 2059 2060 /** Check that classes (or interfaces) do not each define an abstract 2061 * method with same name and arguments but incompatible return types. 2062 * @param pos Position to be used for error reporting. 2063 * @param t1 The first argument type. 2064 * @param t2 The second argument type. 2065 */ 2066 public boolean checkCompatibleAbstracts(DiagnosticPosition pos, 2067 Type t1, 2068 Type t2, 2069 Type site) { 2070 if ((site.tsym.flags() & COMPOUND) != 0) { 2071 // special case for intersections: need to eliminate wildcards in supertypes 2072 t1 = types.capture(t1); 2073 t2 = types.capture(t2); 2074 } 2075 return firstIncompatibility(pos, t1, t2, site) == null; 2076 } 2077 2078 /** Return the first method which is defined with same args 2079 * but different return types in two given interfaces, or null if none 2080 * exists. 2081 * @param t1 The first type. 2082 * @param t2 The second type. 2083 * @param site The most derived type. 2084 * @return symbol from t2 that conflicts with one in t1. 2085 */ 2086 private Symbol firstIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) { 2087 Map<TypeSymbol,Type> interfaces1 = new HashMap<>(); 2088 closure(t1, interfaces1); 2089 Map<TypeSymbol,Type> interfaces2; 2090 if (t1 == t2) 2091 interfaces2 = interfaces1; 2092 else 2093 closure(t2, interfaces1, interfaces2 = new HashMap<>()); 2094 2095 for (Type t3 : interfaces1.values()) { 2096 for (Type t4 : interfaces2.values()) { 2097 Symbol s = firstDirectIncompatibility(pos, t3, t4, site); 2098 if (s != null) return s; 2099 } 2100 } 2101 return null; 2102 } 2103 2104 /** Compute all the supertypes of t, indexed by type symbol. */ 2105 private void closure(Type t, Map<TypeSymbol,Type> typeMap) { 2106 if (!t.hasTag(CLASS)) return; 2107 if (typeMap.put(t.tsym, t) == null) { 2108 closure(types.supertype(t), typeMap); 2109 for (Type i : types.interfaces(t)) 2110 closure(i, typeMap); 2111 } 2112 } 2113 2114 /** Compute all the supertypes of t, indexed by type symbol (except those in typesSkip). */ 2115 private void closure(Type t, Map<TypeSymbol,Type> typesSkip, Map<TypeSymbol,Type> typeMap) { 2116 if (!t.hasTag(CLASS)) return; 2117 if (typesSkip.get(t.tsym) != null) return; 2118 if (typeMap.put(t.tsym, t) == null) { 2119 closure(types.supertype(t), typesSkip, typeMap); 2120 for (Type i : types.interfaces(t)) 2121 closure(i, typesSkip, typeMap); 2122 } 2123 } 2124 2125 /** Return the first method in t2 that conflicts with a method from t1. */ 2126 private Symbol firstDirectIncompatibility(DiagnosticPosition pos, Type t1, Type t2, Type site) { 2127 for (Symbol s1 : t1.tsym.members().getSymbols(NON_RECURSIVE)) { 2128 Type st1 = null; 2129 if (s1.kind != MTH || !s1.isInheritedIn(site.tsym, types) || 2130 (s1.flags() & SYNTHETIC) != 0) continue; 2131 Symbol impl = ((MethodSymbol)s1).implementation(site.tsym, types, false); 2132 if (impl != null && (impl.flags() & ABSTRACT) == 0) continue; 2133 for (Symbol s2 : t2.tsym.members().getSymbolsByName(s1.name)) { 2134 if (s1 == s2) continue; 2135 if (s2.kind != MTH || !s2.isInheritedIn(site.tsym, types) || 2136 (s2.flags() & SYNTHETIC) != 0) continue; 2137 if (st1 == null) st1 = types.memberType(t1, s1); 2138 Type st2 = types.memberType(t2, s2); 2139 if (types.overrideEquivalent(st1, st2)) { 2140 List<Type> tvars1 = st1.getTypeArguments(); 2141 List<Type> tvars2 = st2.getTypeArguments(); 2142 Type rt1 = st1.getReturnType(); 2143 Type rt2 = types.subst(st2.getReturnType(), tvars2, tvars1); 2144 boolean compat = 2145 types.isSameType(rt1, rt2) || 2146 !rt1.isPrimitiveOrVoid() && 2147 !rt2.isPrimitiveOrVoid() && 2148 (types.covariantReturnType(rt1, rt2, types.noWarnings) || 2149 types.covariantReturnType(rt2, rt1, types.noWarnings)) || 2150 checkCommonOverriderIn(s1,s2,site); 2151 if (!compat) { 2152 if (types.isSameType(t1, t2)) { 2153 log.error(pos, Errors.IncompatibleDiffRetSameType(t1, 2154 s2.name, types.memberType(t2, s2).getParameterTypes())); 2155 } else { 2156 log.error(pos, Errors.TypesIncompatible(t1, t2, 2157 Fragments.IncompatibleDiffRet(s2.name, types.memberType(t2, s2).getParameterTypes()))); 2158 } 2159 return s2; 2160 } 2161 } else if (checkNameClash((ClassSymbol)site.tsym, s1, s2) && 2162 !checkCommonOverriderIn(s1, s2, site)) { 2163 log.error(pos, Errors.NameClashSameErasureNoOverride( 2164 s1.name, types.memberType(site, s1).asMethodType().getParameterTypes(), s1.location(), 2165 s2.name, types.memberType(site, s2).asMethodType().getParameterTypes(), s2.location())); 2166 return s2; 2167 } 2168 } 2169 } 2170 return null; 2171 } 2172 //WHERE 2173 boolean checkCommonOverriderIn(Symbol s1, Symbol s2, Type site) { 2174 Map<TypeSymbol,Type> supertypes = new HashMap<>(); 2175 Type st1 = types.memberType(site, s1); 2176 Type st2 = types.memberType(site, s2); 2177 closure(site, supertypes); 2178 for (Type t : supertypes.values()) { 2179 for (Symbol s3 : t.tsym.members().getSymbolsByName(s1.name)) { 2180 if (s3 == s1 || s3 == s2 || s3.kind != MTH || (s3.flags() & (BRIDGE|SYNTHETIC)) != 0) continue; 2181 Type st3 = types.memberType(site,s3); 2182 if (types.overrideEquivalent(st3, st1) && 2183 types.overrideEquivalent(st3, st2) && 2184 types.returnTypeSubstitutable(st3, st1) && 2185 types.returnTypeSubstitutable(st3, st2)) { 2186 return true; 2187 } 2188 } 2189 } 2190 return false; 2191 } 2192 2193 /** Check that a given method conforms with any method it overrides. 2194 * @param tree The tree from which positions are extracted 2195 * for errors. 2196 * @param m The overriding method. 2197 */ 2198 void checkOverride(Env<AttrContext> env, JCMethodDecl tree, MethodSymbol m) { 2199 ClassSymbol origin = (ClassSymbol)m.owner; 2200 if ((origin.flags() & ENUM) != 0 && names.finalize.equals(m.name)) { 2201 if (m.overrides(syms.enumFinalFinalize, origin, types, false)) { 2202 log.error(tree.pos(), Errors.EnumNoFinalize); 2203 return; 2204 } 2205 } 2206 if (allowValueClasses && origin.isValueClass() && names.finalize.equals(m.name)) { 2207 if (m.overrides(syms.objectFinalize, origin, types, false)) { 2208 log.warning(tree.pos(), Warnings.ValueFinalize); 2209 } 2210 } 2211 if (allowRecords && origin.isRecord()) { 2212 // let's find out if this is a user defined accessor in which case the @Override annotation is acceptable 2213 Optional<? extends RecordComponent> recordComponent = origin.getRecordComponents().stream() 2214 .filter(rc -> rc.accessor == tree.sym && (rc.accessor.flags_field & GENERATED_MEMBER) == 0).findFirst(); 2215 if (recordComponent.isPresent()) { 2216 return; 2217 } 2218 } 2219 2220 for (Type t = origin.type; t.hasTag(CLASS); 2221 t = types.supertype(t)) { 2222 if (t != origin.type) { 2223 checkOverride(tree, t, origin, m); 2224 } 2225 for (Type t2 : types.interfaces(t)) { 2226 checkOverride(tree, t2, origin, m); 2227 } 2228 } 2229 2230 final boolean explicitOverride = m.attribute(syms.overrideType.tsym) != null; 2231 // Check if this method must override a super method due to being annotated with @Override 2232 // or by virtue of being a member of a diamond inferred anonymous class. Latter case is to 2233 // be treated "as if as they were annotated" with @Override. 2234 boolean mustOverride = explicitOverride || 2235 (env.info.isAnonymousDiamond && !m.isConstructor() && !m.isPrivate()); 2236 if (mustOverride && !isOverrider(m)) { 2237 DiagnosticPosition pos = tree.pos(); 2238 for (JCAnnotation a : tree.getModifiers().annotations) { 2239 if (a.annotationType.type.tsym == syms.overrideType.tsym) { 2240 pos = a.pos(); 2241 break; 2242 } 2243 } 2244 log.error(pos, 2245 explicitOverride ? (m.isStatic() ? Errors.StaticMethodsCannotBeAnnotatedWithOverride : Errors.MethodDoesNotOverrideSuperclass) : 2246 Errors.AnonymousDiamondMethodDoesNotOverrideSuperclass(Fragments.DiamondAnonymousMethodsImplicitlyOverride)); 2247 } 2248 } 2249 2250 void checkOverride(JCTree tree, Type site, ClassSymbol origin, MethodSymbol m) { 2251 TypeSymbol c = site.tsym; 2252 for (Symbol sym : c.members().getSymbolsByName(m.name)) { 2253 if (m.overrides(sym, origin, types, false)) { 2254 if ((sym.flags() & ABSTRACT) == 0) { 2255 checkOverride(tree, m, (MethodSymbol)sym, origin); 2256 } 2257 } 2258 } 2259 } 2260 2261 private Predicate<Symbol> equalsHasCodeFilter = s -> MethodSymbol.implementation_filter.test(s) && 2262 (s.flags() & BAD_OVERRIDE) == 0; 2263 2264 public void checkClassOverrideEqualsAndHashIfNeeded(DiagnosticPosition pos, 2265 ClassSymbol someClass) { 2266 /* At present, annotations cannot possibly have a method that is override 2267 * equivalent with Object.equals(Object) but in any case the condition is 2268 * fine for completeness. 2269 */ 2270 if (someClass == (ClassSymbol)syms.objectType.tsym || 2271 someClass.isInterface() || someClass.isEnum() || 2272 (someClass.flags() & ANNOTATION) != 0 || 2273 (someClass.flags() & ABSTRACT) != 0) return; 2274 //anonymous inner classes implementing interfaces need especial treatment 2275 if (someClass.isAnonymous()) { 2276 List<Type> interfaces = types.interfaces(someClass.type); 2277 if (interfaces != null && !interfaces.isEmpty() && 2278 interfaces.head.tsym == syms.comparatorType.tsym) return; 2279 } 2280 checkClassOverrideEqualsAndHash(pos, someClass); 2281 } 2282 2283 private void checkClassOverrideEqualsAndHash(DiagnosticPosition pos, 2284 ClassSymbol someClass) { 2285 if (lint.isEnabled(LintCategory.OVERRIDES)) { 2286 MethodSymbol equalsAtObject = (MethodSymbol)syms.objectType 2287 .tsym.members().findFirst(names.equals); 2288 MethodSymbol hashCodeAtObject = (MethodSymbol)syms.objectType 2289 .tsym.members().findFirst(names.hashCode); 2290 MethodSymbol equalsImpl = types.implementation(equalsAtObject, 2291 someClass, false, equalsHasCodeFilter); 2292 boolean overridesEquals = equalsImpl != null && 2293 equalsImpl.owner == someClass; 2294 boolean overridesHashCode = types.implementation(hashCodeAtObject, 2295 someClass, false, equalsHasCodeFilter) != hashCodeAtObject; 2296 2297 if (overridesEquals && !overridesHashCode) { 2298 log.warning(pos, 2299 LintWarnings.OverrideEqualsButNotHashcode(someClass)); 2300 } 2301 } 2302 } 2303 2304 public void checkHasMain(DiagnosticPosition pos, ClassSymbol c) { 2305 boolean found = false; 2306 2307 for (Symbol sym : c.members().getSymbolsByName(names.main)) { 2308 if (sym.kind == MTH && (sym.flags() & PRIVATE) == 0) { 2309 MethodSymbol meth = (MethodSymbol)sym; 2310 if (!types.isSameType(meth.getReturnType(), syms.voidType)) { 2311 continue; 2312 } 2313 if (meth.params.isEmpty()) { 2314 found = true; 2315 break; 2316 } 2317 if (meth.params.size() != 1) { 2318 continue; 2319 } 2320 if (!types.isSameType(meth.params.head.type, types.makeArrayType(syms.stringType))) { 2321 continue; 2322 } 2323 2324 found = true; 2325 break; 2326 } 2327 } 2328 2329 if (!found) { 2330 log.error(pos, Errors.ImplicitClassDoesNotHaveMainMethod); 2331 } 2332 } 2333 2334 public void checkModuleName (JCModuleDecl tree) { 2335 Name moduleName = tree.sym.name; 2336 Assert.checkNonNull(moduleName); 2337 if (lint.isEnabled(LintCategory.MODULE)) { 2338 JCExpression qualId = tree.qualId; 2339 while (qualId != null) { 2340 Name componentName; 2341 DiagnosticPosition pos; 2342 switch (qualId.getTag()) { 2343 case SELECT: 2344 JCFieldAccess selectNode = ((JCFieldAccess) qualId); 2345 componentName = selectNode.name; 2346 pos = selectNode.pos(); 2347 qualId = selectNode.selected; 2348 break; 2349 case IDENT: 2350 componentName = ((JCIdent) qualId).name; 2351 pos = qualId.pos(); 2352 qualId = null; 2353 break; 2354 default: 2355 throw new AssertionError("Unexpected qualified identifier: " + qualId.toString()); 2356 } 2357 if (componentName != null) { 2358 String moduleNameComponentString = componentName.toString(); 2359 int nameLength = moduleNameComponentString.length(); 2360 if (nameLength > 0 && Character.isDigit(moduleNameComponentString.charAt(nameLength - 1))) { 2361 log.warning(pos, LintWarnings.PoorChoiceForModuleName(componentName)); 2362 } 2363 } 2364 } 2365 } 2366 } 2367 2368 private boolean checkNameClash(ClassSymbol origin, Symbol s1, Symbol s2) { 2369 ClashFilter cf = new ClashFilter(origin.type); 2370 return (cf.test(s1) && 2371 cf.test(s2) && 2372 types.hasSameArgs(s1.erasure(types), s2.erasure(types))); 2373 } 2374 2375 2376 /** Check that all abstract members of given class have definitions. 2377 * @param pos Position to be used for error reporting. 2378 * @param c The class. 2379 */ 2380 void checkAllDefined(DiagnosticPosition pos, ClassSymbol c) { 2381 MethodSymbol undef = types.firstUnimplementedAbstract(c); 2382 if (undef != null) { 2383 MethodSymbol undef1 = 2384 new MethodSymbol(undef.flags(), undef.name, 2385 types.memberType(c.type, undef), undef.owner); 2386 log.error(pos, 2387 Errors.DoesNotOverrideAbstract(c, undef1, undef1.location())); 2388 } 2389 } 2390 2391 void checkNonCyclicDecl(JCClassDecl tree) { 2392 CycleChecker cc = new CycleChecker(); 2393 cc.scan(tree); 2394 if (!cc.errorFound && !cc.partialCheck) { 2395 tree.sym.flags_field |= ACYCLIC; 2396 } 2397 } 2398 2399 class CycleChecker extends TreeScanner { 2400 2401 Set<Symbol> seenClasses = new HashSet<>(); 2402 boolean errorFound = false; 2403 boolean partialCheck = false; 2404 2405 private void checkSymbol(DiagnosticPosition pos, Symbol sym) { 2406 if (sym != null && sym.kind == TYP) { 2407 Env<AttrContext> classEnv = enter.getEnv((TypeSymbol)sym); 2408 if (classEnv != null) { 2409 DiagnosticSource prevSource = log.currentSource(); 2410 try { 2411 log.useSource(classEnv.toplevel.sourcefile); 2412 scan(classEnv.tree); 2413 } 2414 finally { 2415 log.useSource(prevSource.getFile()); 2416 } 2417 } else if (sym.kind == TYP) { 2418 checkClass(pos, sym, List.nil()); 2419 } 2420 } else if (sym == null || sym.kind != PCK) { 2421 //not completed yet 2422 partialCheck = true; 2423 } 2424 } 2425 2426 @Override 2427 public void visitSelect(JCFieldAccess tree) { 2428 super.visitSelect(tree); 2429 checkSymbol(tree.pos(), tree.sym); 2430 } 2431 2432 @Override 2433 public void visitIdent(JCIdent tree) { 2434 checkSymbol(tree.pos(), tree.sym); 2435 } 2436 2437 @Override 2438 public void visitTypeApply(JCTypeApply tree) { 2439 scan(tree.clazz); 2440 } 2441 2442 @Override 2443 public void visitTypeArray(JCArrayTypeTree tree) { 2444 scan(tree.elemtype); 2445 } 2446 2447 @Override 2448 public void visitClassDef(JCClassDecl tree) { 2449 List<JCTree> supertypes = List.nil(); 2450 if (tree.getExtendsClause() != null) { 2451 supertypes = supertypes.prepend(tree.getExtendsClause()); 2452 } 2453 if (tree.getImplementsClause() != null) { 2454 for (JCTree intf : tree.getImplementsClause()) { 2455 supertypes = supertypes.prepend(intf); 2456 } 2457 } 2458 checkClass(tree.pos(), tree.sym, supertypes); 2459 } 2460 2461 void checkClass(DiagnosticPosition pos, Symbol c, List<JCTree> supertypes) { 2462 if ((c.flags_field & ACYCLIC) != 0) 2463 return; 2464 if (seenClasses.contains(c)) { 2465 errorFound = true; 2466 log.error(pos, Errors.CyclicInheritance(c)); 2467 seenClasses.stream() 2468 .filter(s -> !s.type.isErroneous()) 2469 .filter(ClassSymbol.class::isInstance) 2470 .map(ClassSymbol.class::cast) 2471 .forEach(Check.this::handleCyclic); 2472 } else if (!c.type.isErroneous()) { 2473 try { 2474 seenClasses.add(c); 2475 if (c.type.hasTag(CLASS)) { 2476 if (supertypes.nonEmpty()) { 2477 scan(supertypes); 2478 } 2479 else { 2480 ClassType ct = (ClassType)c.type; 2481 if (ct.supertype_field == null || 2482 ct.interfaces_field == null) { 2483 //not completed yet 2484 partialCheck = true; 2485 return; 2486 } 2487 checkSymbol(pos, ct.supertype_field.tsym); 2488 for (Type intf : ct.interfaces_field) { 2489 checkSymbol(pos, intf.tsym); 2490 } 2491 } 2492 if (c.owner.kind == TYP) { 2493 checkSymbol(pos, c.owner); 2494 } 2495 } 2496 } finally { 2497 seenClasses.remove(c); 2498 } 2499 } 2500 } 2501 } 2502 2503 /** Check for cyclic references. Issue an error if the 2504 * symbol of the type referred to has a LOCKED flag set. 2505 * 2506 * @param pos Position to be used for error reporting. 2507 * @param t The type referred to. 2508 */ 2509 void checkNonCyclic(DiagnosticPosition pos, Type t) { 2510 checkNonCyclicInternal(pos, t); 2511 } 2512 2513 2514 void checkNonCyclic(DiagnosticPosition pos, TypeVar t) { 2515 checkNonCyclic1(pos, t, List.nil()); 2516 } 2517 2518 private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) { 2519 final TypeVar tv; 2520 if (t.hasTag(TYPEVAR) && (t.tsym.flags() & UNATTRIBUTED) != 0) 2521 return; 2522 if (seen.contains(t)) { 2523 tv = (TypeVar)t; 2524 tv.setUpperBound(types.createErrorType(t)); 2525 log.error(pos, Errors.CyclicInheritance(t)); 2526 } else if (t.hasTag(TYPEVAR)) { 2527 tv = (TypeVar)t; 2528 seen = seen.prepend(tv); 2529 for (Type b : types.getBounds(tv)) 2530 checkNonCyclic1(pos, b, seen); 2531 } 2532 } 2533 2534 /** Check for cyclic references. Issue an error if the 2535 * symbol of the type referred to has a LOCKED flag set. 2536 * 2537 * @param pos Position to be used for error reporting. 2538 * @param t The type referred to. 2539 * @return True if the check completed on all attributed classes 2540 */ 2541 private boolean checkNonCyclicInternal(DiagnosticPosition pos, Type t) { 2542 boolean complete = true; // was the check complete? 2543 //- System.err.println("checkNonCyclicInternal("+t+");");//DEBUG 2544 Symbol c = t.tsym; 2545 if ((c.flags_field & ACYCLIC) != 0) return true; 2546 2547 if ((c.flags_field & LOCKED) != 0) { 2548 log.error(pos, Errors.CyclicInheritance(c)); 2549 handleCyclic((ClassSymbol)c); 2550 } else if (!c.type.isErroneous()) { 2551 try { 2552 c.flags_field |= LOCKED; 2553 if (c.type.hasTag(CLASS)) { 2554 ClassType clazz = (ClassType)c.type; 2555 if (clazz.interfaces_field != null) 2556 for (List<Type> l=clazz.interfaces_field; l.nonEmpty(); l=l.tail) 2557 complete &= checkNonCyclicInternal(pos, l.head); 2558 if (clazz.supertype_field != null) { 2559 Type st = clazz.supertype_field; 2560 if (st != null && st.hasTag(CLASS)) 2561 complete &= checkNonCyclicInternal(pos, st); 2562 } 2563 if (c.owner.kind == TYP) 2564 complete &= checkNonCyclicInternal(pos, c.owner.type); 2565 } 2566 } finally { 2567 c.flags_field &= ~LOCKED; 2568 } 2569 } 2570 if (complete) 2571 complete = ((c.flags_field & UNATTRIBUTED) == 0) && c.isCompleted(); 2572 if (complete) c.flags_field |= ACYCLIC; 2573 return complete; 2574 } 2575 2576 /** Handle finding an inheritance cycle on a class by setting 2577 * the class' and its supertypes' types to the error type. 2578 **/ 2579 private void handleCyclic(ClassSymbol c) { 2580 for (List<Type> l=types.interfaces(c.type); l.nonEmpty(); l=l.tail) 2581 l.head = types.createErrorType((ClassSymbol)l.head.tsym, Type.noType); 2582 Type st = types.supertype(c.type); 2583 if (st.hasTag(CLASS)) 2584 ((ClassType)c.type).supertype_field = types.createErrorType((ClassSymbol)st.tsym, Type.noType); 2585 c.type = types.createErrorType(c, c.type); 2586 c.flags_field |= ACYCLIC; 2587 } 2588 2589 /** Check that all methods which implement some 2590 * method conform to the method they implement. 2591 * @param tree The class definition whose members are checked. 2592 */ 2593 void checkImplementations(JCClassDecl tree) { 2594 checkImplementations(tree, tree.sym, tree.sym); 2595 } 2596 //where 2597 /** Check that all methods which implement some 2598 * method in `ic' conform to the method they implement. 2599 */ 2600 void checkImplementations(JCTree tree, ClassSymbol origin, ClassSymbol ic) { 2601 for (List<Type> l = types.closure(ic.type); l.nonEmpty(); l = l.tail) { 2602 ClassSymbol lc = (ClassSymbol)l.head.tsym; 2603 if ((lc.flags() & ABSTRACT) != 0) { 2604 for (Symbol sym : lc.members().getSymbols(NON_RECURSIVE)) { 2605 if (sym.kind == MTH && 2606 (sym.flags() & (STATIC|ABSTRACT)) == ABSTRACT) { 2607 MethodSymbol absmeth = (MethodSymbol)sym; 2608 MethodSymbol implmeth = absmeth.implementation(origin, types, false); 2609 if (implmeth != null && implmeth != absmeth && 2610 (implmeth.owner.flags() & INTERFACE) == 2611 (origin.flags() & INTERFACE)) { 2612 // don't check if implmeth is in a class, yet 2613 // origin is an interface. This case arises only 2614 // if implmeth is declared in Object. The reason is 2615 // that interfaces really don't inherit from 2616 // Object it's just that the compiler represents 2617 // things that way. 2618 checkOverride(tree, implmeth, absmeth, origin); 2619 } 2620 } 2621 } 2622 } 2623 } 2624 } 2625 2626 /** Check that all abstract methods implemented by a class are 2627 * mutually compatible. 2628 * @param pos Position to be used for error reporting. 2629 * @param c The class whose interfaces are checked. 2630 */ 2631 void checkCompatibleSupertypes(DiagnosticPosition pos, Type c) { 2632 List<Type> supertypes = types.interfaces(c); 2633 Type supertype = types.supertype(c); 2634 if (supertype.hasTag(CLASS) && 2635 (supertype.tsym.flags() & ABSTRACT) != 0) 2636 supertypes = supertypes.prepend(supertype); 2637 for (List<Type> l = supertypes; l.nonEmpty(); l = l.tail) { 2638 if (!l.head.getTypeArguments().isEmpty() && 2639 !checkCompatibleAbstracts(pos, l.head, l.head, c)) 2640 return; 2641 for (List<Type> m = supertypes; m != l; m = m.tail) 2642 if (!checkCompatibleAbstracts(pos, l.head, m.head, c)) 2643 return; 2644 } 2645 checkCompatibleConcretes(pos, c); 2646 2647 Type identitySuper = null; 2648 for (Type t : types.closure(c)) { 2649 if (t != c) { 2650 if (t.isIdentityClass() && (t.tsym.flags() & VALUE_BASED) == 0) 2651 identitySuper = t; 2652 if (c.isValueClass() && identitySuper != null && identitySuper.tsym != syms.objectType.tsym) { // Object is special 2653 log.error(pos, Errors.ValueTypeHasIdentitySuperType(c, identitySuper)); 2654 break; 2655 } 2656 } 2657 } 2658 } 2659 2660 /** Check that all non-override equivalent methods accessible from 'site' 2661 * are mutually compatible (JLS 8.4.8/9.4.1). 2662 * 2663 * @param pos Position to be used for error reporting. 2664 * @param site The class whose methods are checked. 2665 * @param sym The method symbol to be checked. 2666 */ 2667 void checkOverrideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) { 2668 ClashFilter cf = new ClashFilter(site); 2669 //for each method m1 that is overridden (directly or indirectly) 2670 //by method 'sym' in 'site'... 2671 2672 ArrayList<Symbol> symbolsByName = new ArrayList<>(); 2673 types.membersClosure(site, false).getSymbolsByName(sym.name, cf).forEach(symbolsByName::add); 2674 for (Symbol m1 : symbolsByName) { 2675 if (!sym.overrides(m1, site.tsym, types, false)) { 2676 continue; 2677 } 2678 2679 //...check each method m2 that is a member of 'site' 2680 for (Symbol m2 : symbolsByName) { 2681 if (m2 == m1) continue; 2682 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as 2683 //a member of 'site') and (ii) m1 has the same erasure as m2, issue an error 2684 if (!types.isSubSignature(sym.type, types.memberType(site, m2)) && 2685 types.hasSameArgs(m2.erasure(types), m1.erasure(types))) { 2686 sym.flags_field |= CLASH; 2687 if (m1 == sym) { 2688 log.error(pos, Errors.NameClashSameErasureNoOverride( 2689 m1.name, types.memberType(site, m1).asMethodType().getParameterTypes(), m1.location(), 2690 m2.name, types.memberType(site, m2).asMethodType().getParameterTypes(), m2.location())); 2691 } else { 2692 ClassType ct = (ClassType)site; 2693 String kind = ct.isInterface() ? "interface" : "class"; 2694 log.error(pos, Errors.NameClashSameErasureNoOverride1( 2695 kind, 2696 ct.tsym.name, 2697 m1.name, 2698 types.memberType(site, m1).asMethodType().getParameterTypes(), 2699 m1.location(), 2700 m2.name, 2701 types.memberType(site, m2).asMethodType().getParameterTypes(), 2702 m2.location())); 2703 } 2704 return; 2705 } 2706 } 2707 } 2708 } 2709 2710 /** Check that all static methods accessible from 'site' are 2711 * mutually compatible (JLS 8.4.8). 2712 * 2713 * @param pos Position to be used for error reporting. 2714 * @param site The class whose methods are checked. 2715 * @param sym The method symbol to be checked. 2716 */ 2717 void checkHideClashes(DiagnosticPosition pos, Type site, MethodSymbol sym) { 2718 ClashFilter cf = new ClashFilter(site); 2719 //for each method m1 that is a member of 'site'... 2720 for (Symbol s : types.membersClosure(site, true).getSymbolsByName(sym.name, cf)) { 2721 //if (i) the signature of 'sym' is not a subsignature of m1 (seen as 2722 //a member of 'site') and (ii) 'sym' has the same erasure as m1, issue an error 2723 if (!types.isSubSignature(sym.type, types.memberType(site, s))) { 2724 if (types.hasSameArgs(s.erasure(types), sym.erasure(types))) { 2725 log.error(pos, 2726 Errors.NameClashSameErasureNoHide(sym, sym.location(), s, s.location())); 2727 return; 2728 } 2729 } 2730 } 2731 } 2732 2733 //where 2734 private class ClashFilter implements Predicate<Symbol> { 2735 2736 Type site; 2737 2738 ClashFilter(Type site) { 2739 this.site = site; 2740 } 2741 2742 boolean shouldSkip(Symbol s) { 2743 return (s.flags() & CLASH) != 0 && 2744 s.owner == site.tsym; 2745 } 2746 2747 @Override 2748 public boolean test(Symbol s) { 2749 return s.kind == MTH && 2750 (s.flags() & SYNTHETIC) == 0 && 2751 !shouldSkip(s) && 2752 s.isInheritedIn(site.tsym, types) && 2753 !s.isConstructor(); 2754 } 2755 } 2756 2757 void checkDefaultMethodClashes(DiagnosticPosition pos, Type site) { 2758 DefaultMethodClashFilter dcf = new DefaultMethodClashFilter(site); 2759 for (Symbol m : types.membersClosure(site, false).getSymbols(dcf)) { 2760 Assert.check(m.kind == MTH); 2761 List<MethodSymbol> prov = types.interfaceCandidates(site, (MethodSymbol)m); 2762 if (prov.size() > 1) { 2763 ListBuffer<Symbol> abstracts = new ListBuffer<>(); 2764 ListBuffer<Symbol> defaults = new ListBuffer<>(); 2765 for (MethodSymbol provSym : prov) { 2766 if ((provSym.flags() & DEFAULT) != 0) { 2767 defaults = defaults.append(provSym); 2768 } else if ((provSym.flags() & ABSTRACT) != 0) { 2769 abstracts = abstracts.append(provSym); 2770 } 2771 if (defaults.nonEmpty() && defaults.size() + abstracts.size() >= 2) { 2772 //strong semantics - issue an error if two sibling interfaces 2773 //have two override-equivalent defaults - or if one is abstract 2774 //and the other is default 2775 Fragment diagKey; 2776 Symbol s1 = defaults.first(); 2777 Symbol s2; 2778 if (defaults.size() > 1) { 2779 s2 = defaults.toList().tail.head; 2780 diagKey = Fragments.IncompatibleUnrelatedDefaults(Kinds.kindName(site.tsym), site, 2781 m.name, types.memberType(site, m).getParameterTypes(), 2782 s1.location(), s2.location()); 2783 2784 } else { 2785 s2 = abstracts.first(); 2786 diagKey = Fragments.IncompatibleAbstractDefault(Kinds.kindName(site.tsym), site, 2787 m.name, types.memberType(site, m).getParameterTypes(), 2788 s1.location(), s2.location()); 2789 } 2790 log.error(pos, Errors.TypesIncompatible(s1.location().type, s2.location().type, diagKey)); 2791 break; 2792 } 2793 } 2794 } 2795 } 2796 } 2797 2798 //where 2799 private class DefaultMethodClashFilter implements Predicate<Symbol> { 2800 2801 Type site; 2802 2803 DefaultMethodClashFilter(Type site) { 2804 this.site = site; 2805 } 2806 2807 @Override 2808 public boolean test(Symbol s) { 2809 return s.kind == MTH && 2810 (s.flags() & DEFAULT) != 0 && 2811 s.isInheritedIn(site.tsym, types) && 2812 !s.isConstructor(); 2813 } 2814 } 2815 2816 /** Report warnings for potentially ambiguous method declarations in the given site. */ 2817 void checkPotentiallyAmbiguousOverloads(JCClassDecl tree, Type site) { 2818 2819 // Skip if warning not enabled 2820 if (!lint.isEnabled(LintCategory.OVERLOADS)) 2821 return; 2822 2823 // Gather all of site's methods, including overridden methods, grouped by name (except Object methods) 2824 List<java.util.List<MethodSymbol>> methodGroups = methodsGroupedByName(site, 2825 new PotentiallyAmbiguousFilter(site), ArrayList::new); 2826 2827 // Build the predicate that determines if site is responsible for an ambiguity 2828 BiPredicate<MethodSymbol, MethodSymbol> responsible = buildResponsiblePredicate(site, methodGroups); 2829 2830 // Now remove overridden methods from each group, leaving only site's actual members 2831 methodGroups.forEach(list -> removePreempted(list, (m1, m2) -> m1.overrides(m2, site.tsym, types, false))); 2832 2833 // Allow site's own declared methods (only) to apply @SuppressWarnings("overloads") 2834 methodGroups.forEach(list -> list.removeIf( 2835 m -> m.owner == site.tsym && !lint.augment(m).isEnabled(LintCategory.OVERLOADS))); 2836 2837 // Warn about ambiguous overload method pairs for which site is responsible 2838 methodGroups.forEach(list -> compareAndRemove(list, (m1, m2) -> { 2839 2840 // See if this is an ambiguous overload for which "site" is responsible 2841 if (!potentiallyAmbiguousOverload(site, m1, m2) || !responsible.test(m1, m2)) 2842 return 0; 2843 2844 // Locate the warning at one of the methods, if possible 2845 DiagnosticPosition pos = 2846 m1.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m1, tree) : 2847 m2.owner == site.tsym ? TreeInfo.diagnosticPositionFor(m2, tree) : 2848 tree.pos(); 2849 2850 // Log the warning 2851 log.warning(pos, 2852 LintWarnings.PotentiallyAmbiguousOverload( 2853 m1.asMemberOf(site, types), m1.location(), 2854 m2.asMemberOf(site, types), m2.location())); 2855 2856 // Don't warn again for either of these two methods 2857 return FIRST | SECOND; 2858 })); 2859 } 2860 2861 /** Build a predicate that determines, given two methods that are members of the given class, 2862 * whether the class should be held "responsible" if the methods are potentially ambiguous. 2863 * 2864 * Sometimes ambiguous methods are unavoidable because they're inherited from a supertype. 2865 * For example, any subtype of Spliterator.OfInt will have ambiguities for both 2866 * forEachRemaining() and tryAdvance() (in both cases the overloads are IntConsumer and 2867 * Consumer<? super Integer>). So we only want to "blame" a class when that class is 2868 * itself responsible for creating the ambiguity. We declare that a class C is "responsible" 2869 * for the ambiguity between two methods m1 and m2 if there is no direct supertype T of C 2870 * such that m1 and m2, or some overrides thereof, both exist in T and are ambiguous in T. 2871 * As an optimization, we first check if either method is declared in C and does not override 2872 * any other methods; in this case the class is definitely responsible. 2873 */ 2874 BiPredicate<MethodSymbol, MethodSymbol> buildResponsiblePredicate(Type site, 2875 List<? extends Collection<MethodSymbol>> methodGroups) { 2876 2877 // Define the "overrides" predicate 2878 BiPredicate<MethodSymbol, MethodSymbol> overrides = (m1, m2) -> m1.overrides(m2, site.tsym, types, false); 2879 2880 // Map each method declared in site to a list of the supertype method(s) it directly overrides 2881 HashMap<MethodSymbol, ArrayList<MethodSymbol>> overriddenMethodsMap = new HashMap<>(); 2882 methodGroups.forEach(list -> { 2883 for (MethodSymbol m : list) { 2884 2885 // Skip methods not declared in site 2886 if (m.owner != site.tsym) 2887 continue; 2888 2889 // Gather all supertype methods overridden by m, directly or indirectly 2890 ArrayList<MethodSymbol> overriddenMethods = list.stream() 2891 .filter(m2 -> m2 != m && overrides.test(m, m2)) 2892 .collect(Collectors.toCollection(ArrayList::new)); 2893 2894 // Eliminate non-direct overrides 2895 removePreempted(overriddenMethods, overrides); 2896 2897 // Add to map 2898 overriddenMethodsMap.put(m, overriddenMethods); 2899 } 2900 }); 2901 2902 // Build the predicate 2903 return (m1, m2) -> { 2904 2905 // Get corresponding supertype methods (if declared in site) 2906 java.util.List<MethodSymbol> overriddenMethods1 = overriddenMethodsMap.get(m1); 2907 java.util.List<MethodSymbol> overriddenMethods2 = overriddenMethodsMap.get(m2); 2908 2909 // Quick check for the case where a method was added by site itself 2910 if (overriddenMethods1 != null && overriddenMethods1.isEmpty()) 2911 return true; 2912 if (overriddenMethods2 != null && overriddenMethods2.isEmpty()) 2913 return true; 2914 2915 // Get each method's corresponding method(s) from supertypes of site 2916 java.util.List<MethodSymbol> supertypeMethods1 = overriddenMethods1 != null ? 2917 overriddenMethods1 : Collections.singletonList(m1); 2918 java.util.List<MethodSymbol> supertypeMethods2 = overriddenMethods2 != null ? 2919 overriddenMethods2 : Collections.singletonList(m2); 2920 2921 // See if we can blame some direct supertype instead 2922 return types.directSupertypes(site).stream() 2923 .filter(stype -> stype != syms.objectType) 2924 .map(stype -> stype.tsym.type) // view supertype in its original form 2925 .noneMatch(stype -> { 2926 for (MethodSymbol sm1 : supertypeMethods1) { 2927 if (!types.isSubtype(types.erasure(stype), types.erasure(sm1.owner.type))) 2928 continue; 2929 for (MethodSymbol sm2 : supertypeMethods2) { 2930 if (!types.isSubtype(types.erasure(stype), types.erasure(sm2.owner.type))) 2931 continue; 2932 if (potentiallyAmbiguousOverload(stype, sm1, sm2)) 2933 return true; 2934 } 2935 } 2936 return false; 2937 }); 2938 }; 2939 } 2940 2941 /** Gather all of site's methods, including overridden methods, grouped and sorted by name, 2942 * after applying the given filter. 2943 */ 2944 <C extends Collection<MethodSymbol>> List<C> methodsGroupedByName(Type site, 2945 Predicate<Symbol> filter, Supplier<? extends C> groupMaker) { 2946 Iterable<Symbol> symbols = types.membersClosure(site, false).getSymbols(filter, RECURSIVE); 2947 return StreamSupport.stream(symbols.spliterator(), false) 2948 .map(MethodSymbol.class::cast) 2949 .collect(Collectors.groupingBy(m -> m.name, Collectors.toCollection(groupMaker))) 2950 .entrySet() 2951 .stream() 2952 .sorted(Comparator.comparing(e -> e.getKey().toString())) 2953 .map(Map.Entry::getValue) 2954 .collect(List.collector()); 2955 } 2956 2957 /** Compare elements in a list pair-wise in order to remove some of them. 2958 * @param list mutable list of items 2959 * @param comparer returns flag bit(s) to remove FIRST and/or SECOND 2960 */ 2961 <T> void compareAndRemove(java.util.List<T> list, ToIntBiFunction<? super T, ? super T> comparer) { 2962 for (int index1 = 0; index1 < list.size() - 1; index1++) { 2963 T item1 = list.get(index1); 2964 for (int index2 = index1 + 1; index2 < list.size(); index2++) { 2965 T item2 = list.get(index2); 2966 int flags = comparer.applyAsInt(item1, item2); 2967 if ((flags & SECOND) != 0) 2968 list.remove(index2--); // remove item2 2969 if ((flags & FIRST) != 0) { 2970 list.remove(index1--); // remove item1 2971 break; 2972 } 2973 } 2974 } 2975 } 2976 2977 /** Remove elements in a list that are preempted by some other element in the list. 2978 * @param list mutable list of items 2979 * @param preempts decides if one item preempts another, causing the second one to be removed 2980 */ 2981 <T> void removePreempted(java.util.List<T> list, BiPredicate<? super T, ? super T> preempts) { 2982 compareAndRemove(list, (item1, item2) -> { 2983 int flags = 0; 2984 if (preempts.test(item1, item2)) 2985 flags |= SECOND; 2986 if (preempts.test(item2, item1)) 2987 flags |= FIRST; 2988 return flags; 2989 }); 2990 } 2991 2992 /** Filters method candidates for the "potentially ambiguous method" check */ 2993 class PotentiallyAmbiguousFilter extends ClashFilter { 2994 2995 PotentiallyAmbiguousFilter(Type site) { 2996 super(site); 2997 } 2998 2999 @Override 3000 boolean shouldSkip(Symbol s) { 3001 return s.owner.type.tsym == syms.objectType.tsym || super.shouldSkip(s); 3002 } 3003 } 3004 3005 /** 3006 * Report warnings for potentially ambiguous method declarations. Two declarations 3007 * are potentially ambiguous if they feature two unrelated functional interface 3008 * in same argument position (in which case, a call site passing an implicit 3009 * lambda would be ambiguous). This assumes they already have the same name. 3010 */ 3011 boolean potentiallyAmbiguousOverload(Type site, MethodSymbol msym1, MethodSymbol msym2) { 3012 Assert.check(msym1.name == msym2.name); 3013 if (msym1 == msym2) 3014 return false; 3015 Type mt1 = types.memberType(site, msym1); 3016 Type mt2 = types.memberType(site, msym2); 3017 //if both generic methods, adjust type variables 3018 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL) && 3019 types.hasSameBounds((ForAll)mt1, (ForAll)mt2)) { 3020 mt2 = types.subst(mt2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars); 3021 } 3022 //expand varargs methods if needed 3023 int maxLength = Math.max(mt1.getParameterTypes().length(), mt2.getParameterTypes().length()); 3024 List<Type> args1 = rs.adjustArgs(mt1.getParameterTypes(), msym1, maxLength, true); 3025 List<Type> args2 = rs.adjustArgs(mt2.getParameterTypes(), msym2, maxLength, true); 3026 //if arities don't match, exit 3027 if (args1.length() != args2.length()) 3028 return false; 3029 boolean potentiallyAmbiguous = false; 3030 while (args1.nonEmpty() && args2.nonEmpty()) { 3031 Type s = args1.head; 3032 Type t = args2.head; 3033 if (!types.isSubtype(t, s) && !types.isSubtype(s, t)) { 3034 if (types.isFunctionalInterface(s) && types.isFunctionalInterface(t) && 3035 types.findDescriptorType(s).getParameterTypes().length() > 0 && 3036 types.findDescriptorType(s).getParameterTypes().length() == 3037 types.findDescriptorType(t).getParameterTypes().length()) { 3038 potentiallyAmbiguous = true; 3039 } else { 3040 return false; 3041 } 3042 } 3043 args1 = args1.tail; 3044 args2 = args2.tail; 3045 } 3046 return potentiallyAmbiguous; 3047 } 3048 3049 // Apply special flag "-XDwarnOnAccessToMembers" which turns on just this particular warning for all types of access 3050 void checkAccessFromSerializableElement(final JCTree tree, boolean isLambda) { 3051 final Lint prevLint = setLint(warnOnAnyAccessToMembers ? lint.enable(LintCategory.SERIAL) : lint); 3052 try { 3053 if (warnOnAnyAccessToMembers || isLambda) 3054 checkAccessFromSerializableElementInner(tree, isLambda); 3055 } finally { 3056 setLint(prevLint); 3057 } 3058 } 3059 3060 private void checkAccessFromSerializableElementInner(final JCTree tree, boolean isLambda) { 3061 if (lint.isEnabled(LintCategory.SERIAL)) { 3062 Symbol sym = TreeInfo.symbol(tree); 3063 if (!sym.kind.matches(KindSelector.VAL_MTH)) { 3064 return; 3065 } 3066 3067 if (sym.kind == VAR) { 3068 if ((sym.flags() & PARAMETER) != 0 || 3069 sym.isDirectlyOrIndirectlyLocal() || 3070 sym.name == names._this || 3071 sym.name == names._super) { 3072 return; 3073 } 3074 } 3075 3076 if (!types.isSubtype(sym.owner.type, syms.serializableType) && 3077 isEffectivelyNonPublic(sym)) { 3078 if (isLambda) { 3079 if (belongsToRestrictedPackage(sym)) { 3080 log.warning(tree.pos(), 3081 LintWarnings.AccessToMemberFromSerializableLambda(sym)); 3082 } 3083 } else { 3084 log.warning(tree.pos(), 3085 LintWarnings.AccessToMemberFromSerializableElement(sym)); 3086 } 3087 } 3088 } 3089 } 3090 3091 private boolean isEffectivelyNonPublic(Symbol sym) { 3092 if (sym.packge() == syms.rootPackage) { 3093 return false; 3094 } 3095 3096 while (sym.kind != PCK) { 3097 if ((sym.flags() & PUBLIC) == 0) { 3098 return true; 3099 } 3100 sym = sym.owner; 3101 } 3102 return false; 3103 } 3104 3105 private boolean belongsToRestrictedPackage(Symbol sym) { 3106 String fullName = sym.packge().fullname.toString(); 3107 return fullName.startsWith("java.") || 3108 fullName.startsWith("javax.") || 3109 fullName.startsWith("sun.") || 3110 fullName.contains(".internal."); 3111 } 3112 3113 /** Check that class c does not implement directly or indirectly 3114 * the same parameterized interface with two different argument lists. 3115 * @param pos Position to be used for error reporting. 3116 * @param type The type whose interfaces are checked. 3117 */ 3118 void checkClassBounds(DiagnosticPosition pos, Type type) { 3119 checkClassBounds(pos, new HashMap<TypeSymbol,Type>(), type); 3120 } 3121 //where 3122 /** Enter all interfaces of type `type' into the hash table `seensofar' 3123 * with their class symbol as key and their type as value. Make 3124 * sure no class is entered with two different types. 3125 */ 3126 void checkClassBounds(DiagnosticPosition pos, 3127 Map<TypeSymbol,Type> seensofar, 3128 Type type) { 3129 if (type.isErroneous()) return; 3130 for (List<Type> l = types.interfaces(type); l.nonEmpty(); l = l.tail) { 3131 Type it = l.head; 3132 if (type.hasTag(CLASS) && !it.hasTag(CLASS)) continue; // JLS 8.1.5 3133 3134 Type oldit = seensofar.put(it.tsym, it); 3135 if (oldit != null) { 3136 List<Type> oldparams = oldit.allparams(); 3137 List<Type> newparams = it.allparams(); 3138 if (!types.containsTypeEquivalent(oldparams, newparams)) 3139 log.error(pos, 3140 Errors.CantInheritDiffArg(it.tsym, 3141 Type.toString(oldparams), 3142 Type.toString(newparams))); 3143 } 3144 checkClassBounds(pos, seensofar, it); 3145 } 3146 Type st = types.supertype(type); 3147 if (type.hasTag(CLASS) && !st.hasTag(CLASS)) return; // JLS 8.1.4 3148 if (st != Type.noType) checkClassBounds(pos, seensofar, st); 3149 } 3150 3151 /** Enter interface into into set. 3152 * If it existed already, issue a "repeated interface" error. 3153 */ 3154 void checkNotRepeated(DiagnosticPosition pos, Type it, Set<Symbol> its) { 3155 if (its.contains(it.tsym)) 3156 log.error(pos, Errors.RepeatedInterface); 3157 else { 3158 its.add(it.tsym); 3159 } 3160 } 3161 3162 /* ************************************************************************* 3163 * Check annotations 3164 **************************************************************************/ 3165 3166 /** 3167 * Recursively validate annotations values 3168 */ 3169 void validateAnnotationTree(JCTree tree) { 3170 class AnnotationValidator extends TreeScanner { 3171 @Override 3172 public void visitAnnotation(JCAnnotation tree) { 3173 if (!tree.type.isErroneous() && tree.type.tsym.isAnnotationType()) { 3174 super.visitAnnotation(tree); 3175 validateAnnotation(tree); 3176 } 3177 } 3178 } 3179 tree.accept(new AnnotationValidator()); 3180 } 3181 3182 /** 3183 * {@literal 3184 * Annotation types are restricted to primitives, String, an 3185 * enum, an annotation, Class, Class<?>, Class<? extends 3186 * Anything>, arrays of the preceding. 3187 * } 3188 */ 3189 void validateAnnotationType(JCTree restype) { 3190 // restype may be null if an error occurred, so don't bother validating it 3191 if (restype != null) { 3192 validateAnnotationType(restype.pos(), restype.type); 3193 } 3194 } 3195 3196 void validateAnnotationType(DiagnosticPosition pos, Type type) { 3197 if (type.isPrimitive()) return; 3198 if (types.isSameType(type, syms.stringType)) return; 3199 if ((type.tsym.flags() & Flags.ENUM) != 0) return; 3200 if ((type.tsym.flags() & Flags.ANNOTATION) != 0) return; 3201 if (types.cvarLowerBound(type).tsym == syms.classType.tsym) return; 3202 if (types.isArray(type) && !types.isArray(types.elemtype(type))) { 3203 validateAnnotationType(pos, types.elemtype(type)); 3204 return; 3205 } 3206 log.error(pos, Errors.InvalidAnnotationMemberType); 3207 } 3208 3209 /** 3210 * "It is also a compile-time error if any method declared in an 3211 * annotation type has a signature that is override-equivalent to 3212 * that of any public or protected method declared in class Object 3213 * or in the interface annotation.Annotation." 3214 * 3215 * @jls 9.6 Annotation Types 3216 */ 3217 void validateAnnotationMethod(DiagnosticPosition pos, MethodSymbol m) { 3218 for (Type sup = syms.annotationType; sup.hasTag(CLASS); sup = types.supertype(sup)) { 3219 Scope s = sup.tsym.members(); 3220 for (Symbol sym : s.getSymbolsByName(m.name)) { 3221 if (sym.kind == MTH && 3222 (sym.flags() & (PUBLIC | PROTECTED)) != 0 && 3223 types.overrideEquivalent(m.type, sym.type)) 3224 log.error(pos, Errors.IntfAnnotationMemberClash(sym, sup)); 3225 } 3226 } 3227 } 3228 3229 /** Check the annotations of a symbol. 3230 */ 3231 public void validateAnnotations(List<JCAnnotation> annotations, JCTree declarationTree, Symbol s) { 3232 for (JCAnnotation a : annotations) 3233 validateAnnotation(a, declarationTree, s); 3234 } 3235 3236 /** Check the type annotations. 3237 */ 3238 public void validateTypeAnnotations(List<JCAnnotation> annotations, Symbol s, boolean isTypeParameter) { 3239 for (JCAnnotation a : annotations) 3240 validateTypeAnnotation(a, s, isTypeParameter); 3241 } 3242 3243 /** Check an annotation of a symbol. 3244 */ 3245 private void validateAnnotation(JCAnnotation a, JCTree declarationTree, Symbol s) { 3246 /** NOTE: if annotation processors are present, annotation processing rounds can happen after this method, 3247 * this can impact in particular records for which annotations are forcibly propagated. 3248 */ 3249 validateAnnotationTree(a); 3250 boolean isRecordMember = ((s.flags_field & RECORD) != 0 || s.enclClass() != null && s.enclClass().isRecord()); 3251 3252 boolean isRecordField = (s.flags_field & RECORD) != 0 && 3253 declarationTree.hasTag(VARDEF) && 3254 s.owner.kind == TYP; 3255 3256 if (isRecordField) { 3257 // first we need to check if the annotation is applicable to records 3258 Name[] targets = getTargetNames(a); 3259 boolean appliesToRecords = false; 3260 for (Name target : targets) { 3261 appliesToRecords = 3262 target == names.FIELD || 3263 target == names.PARAMETER || 3264 target == names.METHOD || 3265 target == names.TYPE_USE || 3266 target == names.RECORD_COMPONENT; 3267 if (appliesToRecords) { 3268 break; 3269 } 3270 } 3271 if (!appliesToRecords) { 3272 log.error(a.pos(), Errors.AnnotationTypeNotApplicable); 3273 } else { 3274 /* lets now find the annotations in the field that are targeted to record components and append them to 3275 * the corresponding record component 3276 */ 3277 ClassSymbol recordClass = (ClassSymbol) s.owner; 3278 RecordComponent rc = recordClass.getRecordComponent((VarSymbol)s); 3279 SymbolMetadata metadata = rc.getMetadata(); 3280 if (metadata == null || metadata.isEmpty()) { 3281 /* if not is empty then we have already been here, which is the case if multiple annotations are applied 3282 * to the record component declaration 3283 */ 3284 rc.appendAttributes(s.getRawAttributes().stream().filter(anno -> 3285 Arrays.stream(getTargetNames(anno.type.tsym)).anyMatch(name -> name == names.RECORD_COMPONENT) 3286 ).collect(List.collector())); 3287 3288 JCVariableDecl fieldAST = (JCVariableDecl) declarationTree; 3289 for (JCAnnotation fieldAnnot : fieldAST.mods.annotations) { 3290 for (JCAnnotation rcAnnot : rc.declarationFor().mods.annotations) { 3291 if (rcAnnot.pos == fieldAnnot.pos) { 3292 rcAnnot.setType(fieldAnnot.type); 3293 break; 3294 } 3295 } 3296 } 3297 3298 /* At this point, we used to carry over any type annotations from the VARDEF to the record component, but 3299 * that is problematic, since we get here only when *some* annotation is applied to the SE5 (declaration) 3300 * annotation location, inadvertently failing to carry over the type annotations when the VarDef has no 3301 * annotations in the SE5 annotation location. 3302 * 3303 * Now type annotations are assigned to record components in a method that would execute irrespective of 3304 * whether there are SE5 annotations on a VarDef viz com.sun.tools.javac.code.TypeAnnotations.TypeAnnotationPositions.visitVarDef 3305 */ 3306 } 3307 } 3308 } 3309 3310 /* the section below is tricky. Annotations applied to record components are propagated to the corresponding 3311 * record member so if an annotation has target: FIELD, it is propagated to the corresponding FIELD, if it has 3312 * target METHOD, it is propagated to the accessor and so on. But at the moment when method members are generated 3313 * there is no enough information to propagate only the right annotations. So all the annotations are propagated 3314 * to all the possible locations. 3315 * 3316 * At this point we need to remove all the annotations that are not in place before going on with the annotation 3317 * party. On top of the above there is the issue that there is no AST representing record components, just symbols 3318 * so the corresponding field has been holding all the annotations and it's metadata has been modified as if it 3319 * was both a field and a record component. 3320 * 3321 * So there are two places where we need to trim annotations from: the metadata of the symbol and / or the modifiers 3322 * in the AST. Whatever is in the metadata will be written to the class file, whatever is in the modifiers could 3323 * be see by annotation processors. 3324 * 3325 * The metadata contains both type annotations and declaration annotations. At this point of the game we don't 3326 * need to care about type annotations, they are all in the right place. But we could need to remove declaration 3327 * annotations. So for declaration annotations if they are not applicable to the record member, excluding type 3328 * annotations which are already correct, then we will remove it. For the AST modifiers if the annotation is not 3329 * applicable either as type annotation and or declaration annotation, only in that case it will be removed. 3330 * 3331 * So it could be that annotation is removed as a declaration annotation but it is kept in the AST modifier for 3332 * further inspection by annotation processors. 3333 * 3334 * For example: 3335 * 3336 * import java.lang.annotation.*; 3337 * 3338 * @Target({ElementType.TYPE_USE, ElementType.RECORD_COMPONENT}) 3339 * @Retention(RetentionPolicy.RUNTIME) 3340 * @interface Anno { } 3341 * 3342 * record R(@Anno String s) {} 3343 * 3344 * at this point we will have for the case of the generated field: 3345 * - @Anno in the modifier 3346 * - @Anno as a type annotation 3347 * - @Anno as a declaration annotation 3348 * 3349 * the last one should be removed because the annotation has not FIELD as target but it was applied as a 3350 * declaration annotation because the field was being treated both as a field and as a record component 3351 * as we have already copied the annotations to the record component, now the field doesn't need to hold 3352 * annotations that are not intended for it anymore. Still @Anno has to be kept in the AST's modifiers as it 3353 * is applicable as a type annotation to the type of the field. 3354 */ 3355 3356 if (a.type.tsym.isAnnotationType()) { 3357 Optional<Set<Name>> applicableTargetsOp = getApplicableTargets(a, s); 3358 if (!applicableTargetsOp.isEmpty()) { 3359 Set<Name> applicableTargets = applicableTargetsOp.get(); 3360 boolean notApplicableOrIsTypeUseOnly = applicableTargets.isEmpty() || 3361 applicableTargets.size() == 1 && applicableTargets.contains(names.TYPE_USE); 3362 boolean isCompGeneratedRecordElement = isRecordMember && (s.flags_field & Flags.GENERATED_MEMBER) != 0; 3363 boolean isCompRecordElementWithNonApplicableDeclAnno = isCompGeneratedRecordElement && notApplicableOrIsTypeUseOnly; 3364 3365 if (applicableTargets.isEmpty() || isCompRecordElementWithNonApplicableDeclAnno) { 3366 if (isCompRecordElementWithNonApplicableDeclAnno) { 3367 /* so we have found an annotation that is not applicable to a record member that was generated by the 3368 * compiler. This was intentionally done at TypeEnter, now is the moment strip away the annotations 3369 * that are not applicable to the given record member 3370 */ 3371 JCModifiers modifiers = TreeInfo.getModifiers(declarationTree); 3372 /* lets first remove the annotation from the modifier if it is not applicable, we have to check again as 3373 * it could be a type annotation 3374 */ 3375 if (modifiers != null && applicableTargets.isEmpty()) { 3376 ListBuffer<JCAnnotation> newAnnotations = new ListBuffer<>(); 3377 for (JCAnnotation anno : modifiers.annotations) { 3378 if (anno != a) { 3379 newAnnotations.add(anno); 3380 } 3381 } 3382 modifiers.annotations = newAnnotations.toList(); 3383 } 3384 // now lets remove it from the symbol 3385 s.getMetadata().removeDeclarationMetadata(a.attribute); 3386 } else { 3387 log.error(a.pos(), Errors.AnnotationTypeNotApplicable); 3388 } 3389 } 3390 /* if we are seeing the @SafeVarargs annotation applied to a compiler generated accessor, 3391 * then this is an error as we know that no compiler generated accessor will be a varargs 3392 * method, better to fail asap 3393 */ 3394 if (isCompGeneratedRecordElement && !isRecordField && a.type.tsym == syms.trustMeType.tsym && declarationTree.hasTag(METHODDEF)) { 3395 log.error(a.pos(), Errors.VarargsInvalidTrustmeAnno(syms.trustMeType.tsym, Fragments.VarargsTrustmeOnNonVarargsAccessor(s))); 3396 } 3397 } 3398 } 3399 3400 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) { 3401 if (s.kind != TYP) { 3402 log.error(a.pos(), Errors.BadFunctionalIntfAnno); 3403 } else if (!s.isInterface() || (s.flags() & ANNOTATION) != 0) { 3404 log.error(a.pos(), Errors.BadFunctionalIntfAnno1(Fragments.NotAFunctionalIntf(s))); 3405 } 3406 } 3407 } 3408 3409 public void validateTypeAnnotation(JCAnnotation a, Symbol s, boolean isTypeParameter) { 3410 Assert.checkNonNull(a.type); 3411 // we just want to validate that the anotation doesn't have any wrong target 3412 if (s != null) getApplicableTargets(a, s); 3413 validateAnnotationTree(a); 3414 3415 if (a.hasTag(TYPE_ANNOTATION) && 3416 !a.annotationType.type.isErroneous() && 3417 !isTypeAnnotation(a, isTypeParameter)) { 3418 log.error(a.pos(), Errors.AnnotationTypeNotApplicableToType(a.type)); 3419 } 3420 } 3421 3422 /** 3423 * Validate the proposed container 'repeatable' on the 3424 * annotation type symbol 's'. Report errors at position 3425 * 'pos'. 3426 * 3427 * @param s The (annotation)type declaration annotated with a @Repeatable 3428 * @param repeatable the @Repeatable on 's' 3429 * @param pos where to report errors 3430 */ 3431 public void validateRepeatable(TypeSymbol s, Attribute.Compound repeatable, DiagnosticPosition pos) { 3432 Assert.check(types.isSameType(repeatable.type, syms.repeatableType)); 3433 3434 Type t = null; 3435 List<Pair<MethodSymbol,Attribute>> l = repeatable.values; 3436 if (!l.isEmpty()) { 3437 Assert.check(l.head.fst.name == names.value); 3438 if (l.head.snd instanceof Attribute.Class) { 3439 t = ((Attribute.Class)l.head.snd).getValue(); 3440 } 3441 } 3442 3443 if (t == null) { 3444 // errors should already have been reported during Annotate 3445 return; 3446 } 3447 3448 validateValue(t.tsym, s, pos); 3449 validateRetention(t.tsym, s, pos); 3450 validateDocumented(t.tsym, s, pos); 3451 validateInherited(t.tsym, s, pos); 3452 validateTarget(t.tsym, s, pos); 3453 validateDefault(t.tsym, pos); 3454 } 3455 3456 private void validateValue(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) { 3457 Symbol sym = container.members().findFirst(names.value); 3458 if (sym != null && sym.kind == MTH) { 3459 MethodSymbol m = (MethodSymbol) sym; 3460 Type ret = m.getReturnType(); 3461 if (!(ret.hasTag(ARRAY) && types.isSameType(((ArrayType)ret).elemtype, contained.type))) { 3462 log.error(pos, 3463 Errors.InvalidRepeatableAnnotationValueReturn(container, 3464 ret, 3465 types.makeArrayType(contained.type))); 3466 } 3467 } else { 3468 log.error(pos, Errors.InvalidRepeatableAnnotationNoValue(container)); 3469 } 3470 } 3471 3472 private void validateRetention(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) { 3473 Attribute.RetentionPolicy containerRetention = types.getRetention(container); 3474 Attribute.RetentionPolicy containedRetention = types.getRetention(contained); 3475 3476 boolean error = false; 3477 switch (containedRetention) { 3478 case RUNTIME: 3479 if (containerRetention != Attribute.RetentionPolicy.RUNTIME) { 3480 error = true; 3481 } 3482 break; 3483 case CLASS: 3484 if (containerRetention == Attribute.RetentionPolicy.SOURCE) { 3485 error = true; 3486 } 3487 } 3488 if (error ) { 3489 log.error(pos, 3490 Errors.InvalidRepeatableAnnotationRetention(container, 3491 containerRetention.name(), 3492 contained, 3493 containedRetention.name())); 3494 } 3495 } 3496 3497 private void validateDocumented(Symbol container, Symbol contained, DiagnosticPosition pos) { 3498 if (contained.attribute(syms.documentedType.tsym) != null) { 3499 if (container.attribute(syms.documentedType.tsym) == null) { 3500 log.error(pos, Errors.InvalidRepeatableAnnotationNotDocumented(container, contained)); 3501 } 3502 } 3503 } 3504 3505 private void validateInherited(Symbol container, Symbol contained, DiagnosticPosition pos) { 3506 if (contained.attribute(syms.inheritedType.tsym) != null) { 3507 if (container.attribute(syms.inheritedType.tsym) == null) { 3508 log.error(pos, Errors.InvalidRepeatableAnnotationNotInherited(container, contained)); 3509 } 3510 } 3511 } 3512 3513 private void validateTarget(TypeSymbol container, TypeSymbol contained, DiagnosticPosition pos) { 3514 // The set of targets the container is applicable to must be a subset 3515 // (with respect to annotation target semantics) of the set of targets 3516 // the contained is applicable to. The target sets may be implicit or 3517 // explicit. 3518 3519 Set<Name> containerTargets; 3520 Attribute.Array containerTarget = getAttributeTargetAttribute(container); 3521 if (containerTarget == null) { 3522 containerTargets = getDefaultTargetSet(); 3523 } else { 3524 containerTargets = new HashSet<>(); 3525 for (Attribute app : containerTarget.values) { 3526 if (!(app instanceof Attribute.Enum attributeEnum)) { 3527 continue; // recovery 3528 } 3529 containerTargets.add(attributeEnum.value.name); 3530 } 3531 } 3532 3533 Set<Name> containedTargets; 3534 Attribute.Array containedTarget = getAttributeTargetAttribute(contained); 3535 if (containedTarget == null) { 3536 containedTargets = getDefaultTargetSet(); 3537 } else { 3538 containedTargets = new HashSet<>(); 3539 for (Attribute app : containedTarget.values) { 3540 if (!(app instanceof Attribute.Enum attributeEnum)) { 3541 continue; // recovery 3542 } 3543 containedTargets.add(attributeEnum.value.name); 3544 } 3545 } 3546 3547 if (!isTargetSubsetOf(containerTargets, containedTargets)) { 3548 log.error(pos, Errors.InvalidRepeatableAnnotationIncompatibleTarget(container, contained)); 3549 } 3550 } 3551 3552 /* get a set of names for the default target */ 3553 private Set<Name> getDefaultTargetSet() { 3554 if (defaultTargets == null) { 3555 defaultTargets = Set.of(defaultTargetMetaInfo()); 3556 } 3557 3558 return defaultTargets; 3559 } 3560 private Set<Name> defaultTargets; 3561 3562 3563 /** Checks that s is a subset of t, with respect to ElementType 3564 * semantics, specifically {ANNOTATION_TYPE} is a subset of {TYPE}, 3565 * and {TYPE_USE} covers the set {ANNOTATION_TYPE, TYPE, TYPE_USE, 3566 * TYPE_PARAMETER}. 3567 */ 3568 private boolean isTargetSubsetOf(Set<Name> s, Set<Name> t) { 3569 // Check that all elements in s are present in t 3570 for (Name n2 : s) { 3571 boolean currentElementOk = false; 3572 for (Name n1 : t) { 3573 if (n1 == n2) { 3574 currentElementOk = true; 3575 break; 3576 } else if (n1 == names.TYPE && n2 == names.ANNOTATION_TYPE) { 3577 currentElementOk = true; 3578 break; 3579 } else if (n1 == names.TYPE_USE && 3580 (n2 == names.TYPE || 3581 n2 == names.ANNOTATION_TYPE || 3582 n2 == names.TYPE_PARAMETER)) { 3583 currentElementOk = true; 3584 break; 3585 } 3586 } 3587 if (!currentElementOk) 3588 return false; 3589 } 3590 return true; 3591 } 3592 3593 private void validateDefault(Symbol container, DiagnosticPosition pos) { 3594 // validate that all other elements of containing type has defaults 3595 Scope scope = container.members(); 3596 for(Symbol elm : scope.getSymbols()) { 3597 if (elm.name != names.value && 3598 elm.kind == MTH && 3599 ((MethodSymbol)elm).defaultValue == null) { 3600 log.error(pos, 3601 Errors.InvalidRepeatableAnnotationElemNondefault(container, elm)); 3602 } 3603 } 3604 } 3605 3606 /** Is s a method symbol that overrides a method in a superclass? */ 3607 boolean isOverrider(Symbol s) { 3608 if (s.kind != MTH || s.isStatic()) 3609 return false; 3610 MethodSymbol m = (MethodSymbol)s; 3611 TypeSymbol owner = (TypeSymbol)m.owner; 3612 for (Type sup : types.closure(owner.type)) { 3613 if (sup == owner.type) 3614 continue; // skip "this" 3615 Scope scope = sup.tsym.members(); 3616 for (Symbol sym : scope.getSymbolsByName(m.name)) { 3617 if (!sym.isStatic() && m.overrides(sym, owner, types, true)) 3618 return true; 3619 } 3620 } 3621 return false; 3622 } 3623 3624 /** Is the annotation applicable to types? */ 3625 protected boolean isTypeAnnotation(JCAnnotation a, boolean isTypeParameter) { 3626 List<Attribute> targets = typeAnnotations.annotationTargets(a.annotationType.type.tsym); 3627 return (targets == null) ? 3628 (Feature.NO_TARGET_ANNOTATION_APPLICABILITY.allowedInSource(source) && isTypeParameter) : 3629 targets.stream() 3630 .anyMatch(attr -> isTypeAnnotation(attr, isTypeParameter)); 3631 } 3632 //where 3633 boolean isTypeAnnotation(Attribute a, boolean isTypeParameter) { 3634 Attribute.Enum e = (Attribute.Enum)a; 3635 return (e.value.name == names.TYPE_USE || 3636 (isTypeParameter && e.value.name == names.TYPE_PARAMETER)); 3637 } 3638 3639 /** Is the annotation applicable to the symbol? */ 3640 Name[] getTargetNames(JCAnnotation a) { 3641 return getTargetNames(a.annotationType.type.tsym); 3642 } 3643 3644 public Name[] getTargetNames(TypeSymbol annoSym) { 3645 Attribute.Array arr = getAttributeTargetAttribute(annoSym); 3646 Name[] targets; 3647 if (arr == null) { 3648 targets = defaultTargetMetaInfo(); 3649 } else { 3650 // TODO: can we optimize this? 3651 targets = new Name[arr.values.length]; 3652 for (int i=0; i<arr.values.length; ++i) { 3653 Attribute app = arr.values[i]; 3654 if (!(app instanceof Attribute.Enum attributeEnum)) { 3655 return new Name[0]; 3656 } 3657 targets[i] = attributeEnum.value.name; 3658 } 3659 } 3660 return targets; 3661 } 3662 3663 boolean annotationApplicable(JCAnnotation a, Symbol s) { 3664 Optional<Set<Name>> targets = getApplicableTargets(a, s); 3665 /* the optional could be empty if the annotation is unknown in that case 3666 * we return that it is applicable and if it is erroneous that should imply 3667 * an error at the declaration site 3668 */ 3669 return targets.isEmpty() || targets.isPresent() && !targets.get().isEmpty(); 3670 } 3671 3672 Optional<Set<Name>> getApplicableTargets(JCAnnotation a, Symbol s) { 3673 Attribute.Array arr = getAttributeTargetAttribute(a.annotationType.type.tsym); 3674 Name[] targets; 3675 Set<Name> applicableTargets = new HashSet<>(); 3676 3677 if (arr == null) { 3678 targets = defaultTargetMetaInfo(); 3679 } else { 3680 // TODO: can we optimize this? 3681 targets = new Name[arr.values.length]; 3682 for (int i=0; i<arr.values.length; ++i) { 3683 Attribute app = arr.values[i]; 3684 if (!(app instanceof Attribute.Enum attributeEnum)) { 3685 // recovery 3686 return Optional.empty(); 3687 } 3688 targets[i] = attributeEnum.value.name; 3689 } 3690 } 3691 for (Name target : targets) { 3692 if (target == names.TYPE) { 3693 if (s.kind == TYP) 3694 applicableTargets.add(names.TYPE); 3695 } else if (target == names.FIELD) { 3696 if (s.kind == VAR && s.owner.kind != MTH) 3697 applicableTargets.add(names.FIELD); 3698 } else if (target == names.RECORD_COMPONENT) { 3699 if (s.getKind() == ElementKind.RECORD_COMPONENT) { 3700 applicableTargets.add(names.RECORD_COMPONENT); 3701 } 3702 } else if (target == names.METHOD) { 3703 if (s.kind == MTH && !s.isConstructor()) 3704 applicableTargets.add(names.METHOD); 3705 } else if (target == names.PARAMETER) { 3706 if (s.kind == VAR && 3707 (s.owner.kind == MTH && (s.flags() & PARAMETER) != 0)) { 3708 applicableTargets.add(names.PARAMETER); 3709 } 3710 } else if (target == names.CONSTRUCTOR) { 3711 if (s.kind == MTH && s.isConstructor()) 3712 applicableTargets.add(names.CONSTRUCTOR); 3713 } else if (target == names.LOCAL_VARIABLE) { 3714 if (s.kind == VAR && s.owner.kind == MTH && 3715 (s.flags() & PARAMETER) == 0) { 3716 applicableTargets.add(names.LOCAL_VARIABLE); 3717 } 3718 } else if (target == names.ANNOTATION_TYPE) { 3719 if (s.kind == TYP && (s.flags() & ANNOTATION) != 0) { 3720 applicableTargets.add(names.ANNOTATION_TYPE); 3721 } 3722 } else if (target == names.PACKAGE) { 3723 if (s.kind == PCK) 3724 applicableTargets.add(names.PACKAGE); 3725 } else if (target == names.TYPE_USE) { 3726 if (s.kind == VAR && s.owner.kind == MTH && s.type.hasTag(NONE)) { 3727 //cannot type annotate implicitly typed locals 3728 continue; 3729 } else if (s.kind == TYP || s.kind == VAR || 3730 (s.kind == MTH && !s.isConstructor() && 3731 !s.type.getReturnType().hasTag(VOID)) || 3732 (s.kind == MTH && s.isConstructor())) { 3733 applicableTargets.add(names.TYPE_USE); 3734 } 3735 } else if (target == names.TYPE_PARAMETER) { 3736 if (s.kind == TYP && s.type.hasTag(TYPEVAR)) 3737 applicableTargets.add(names.TYPE_PARAMETER); 3738 } else if (target == names.MODULE) { 3739 if (s.kind == MDL) 3740 applicableTargets.add(names.MODULE); 3741 } else { 3742 log.error(a, Errors.AnnotationUnrecognizedAttributeName(a.type, target)); 3743 return Optional.empty(); // Unknown ElementType 3744 } 3745 } 3746 return Optional.of(applicableTargets); 3747 } 3748 3749 Attribute.Array getAttributeTargetAttribute(TypeSymbol s) { 3750 Attribute.Compound atTarget = s.getAnnotationTypeMetadata().getTarget(); 3751 if (atTarget == null) return null; // ok, is applicable 3752 Attribute atValue = atTarget.member(names.value); 3753 return (atValue instanceof Attribute.Array attributeArray) ? attributeArray : null; 3754 } 3755 3756 private Name[] dfltTargetMeta; 3757 private Name[] defaultTargetMetaInfo() { 3758 if (dfltTargetMeta == null) { 3759 ArrayList<Name> defaultTargets = new ArrayList<>(); 3760 defaultTargets.add(names.PACKAGE); 3761 defaultTargets.add(names.TYPE); 3762 defaultTargets.add(names.FIELD); 3763 defaultTargets.add(names.METHOD); 3764 defaultTargets.add(names.CONSTRUCTOR); 3765 defaultTargets.add(names.ANNOTATION_TYPE); 3766 defaultTargets.add(names.LOCAL_VARIABLE); 3767 defaultTargets.add(names.PARAMETER); 3768 if (allowRecords) { 3769 defaultTargets.add(names.RECORD_COMPONENT); 3770 } 3771 if (allowModules) { 3772 defaultTargets.add(names.MODULE); 3773 } 3774 dfltTargetMeta = defaultTargets.toArray(new Name[0]); 3775 } 3776 return dfltTargetMeta; 3777 } 3778 3779 /** Check an annotation value. 3780 * 3781 * @param a The annotation tree to check 3782 * @return true if this annotation tree is valid, otherwise false 3783 */ 3784 public boolean validateAnnotationDeferErrors(JCAnnotation a) { 3785 boolean res = false; 3786 final Log.DiagnosticHandler diagHandler = new Log.DiscardDiagnosticHandler(log); 3787 try { 3788 res = validateAnnotation(a); 3789 } finally { 3790 log.popDiagnosticHandler(diagHandler); 3791 } 3792 return res; 3793 } 3794 3795 private boolean validateAnnotation(JCAnnotation a) { 3796 boolean isValid = true; 3797 AnnotationTypeMetadata metadata = a.annotationType.type.tsym.getAnnotationTypeMetadata(); 3798 3799 // collect an inventory of the annotation elements 3800 Set<MethodSymbol> elements = metadata.getAnnotationElements(); 3801 3802 // remove the ones that are assigned values 3803 for (JCTree arg : a.args) { 3804 if (!arg.hasTag(ASSIGN)) continue; // recovery 3805 JCAssign assign = (JCAssign)arg; 3806 Symbol m = TreeInfo.symbol(assign.lhs); 3807 if (m == null || m.type.isErroneous()) continue; 3808 if (!elements.remove(m)) { 3809 isValid = false; 3810 log.error(assign.lhs.pos(), 3811 Errors.DuplicateAnnotationMemberValue(m.name, a.type)); 3812 } 3813 } 3814 3815 // all the remaining ones better have default values 3816 List<Name> missingDefaults = List.nil(); 3817 Set<MethodSymbol> membersWithDefault = metadata.getAnnotationElementsWithDefault(); 3818 for (MethodSymbol m : elements) { 3819 if (m.type.isErroneous()) 3820 continue; 3821 3822 if (!membersWithDefault.contains(m)) 3823 missingDefaults = missingDefaults.append(m.name); 3824 } 3825 missingDefaults = missingDefaults.reverse(); 3826 if (missingDefaults.nonEmpty()) { 3827 isValid = false; 3828 Error errorKey = (missingDefaults.size() > 1) 3829 ? Errors.AnnotationMissingDefaultValue1(a.type, missingDefaults) 3830 : Errors.AnnotationMissingDefaultValue(a.type, missingDefaults); 3831 log.error(a.pos(), errorKey); 3832 } 3833 3834 return isValid && validateTargetAnnotationValue(a); 3835 } 3836 3837 /* Validate the special java.lang.annotation.Target annotation */ 3838 boolean validateTargetAnnotationValue(JCAnnotation a) { 3839 // special case: java.lang.annotation.Target must not have 3840 // repeated values in its value member 3841 if (a.annotationType.type.tsym != syms.annotationTargetType.tsym || 3842 a.args.tail == null) 3843 return true; 3844 3845 boolean isValid = true; 3846 if (!a.args.head.hasTag(ASSIGN)) return false; // error recovery 3847 JCAssign assign = (JCAssign) a.args.head; 3848 Symbol m = TreeInfo.symbol(assign.lhs); 3849 if (m.name != names.value) return false; 3850 JCTree rhs = assign.rhs; 3851 if (!rhs.hasTag(NEWARRAY)) return false; 3852 JCNewArray na = (JCNewArray) rhs; 3853 Set<Symbol> targets = new HashSet<>(); 3854 for (JCTree elem : na.elems) { 3855 if (!targets.add(TreeInfo.symbol(elem))) { 3856 isValid = false; 3857 log.error(elem.pos(), Errors.RepeatedAnnotationTarget); 3858 } 3859 } 3860 return isValid; 3861 } 3862 3863 void checkDeprecatedAnnotation(DiagnosticPosition pos, Symbol s) { 3864 if (lint.isEnabled(LintCategory.DEP_ANN) && s.isDeprecatableViaAnnotation() && 3865 (s.flags() & DEPRECATED) != 0 && 3866 !syms.deprecatedType.isErroneous() && 3867 s.attribute(syms.deprecatedType.tsym) == null) { 3868 log.warning(pos, LintWarnings.MissingDeprecatedAnnotation); 3869 } 3870 // Note: @Deprecated has no effect on local variables, parameters and package decls. 3871 if (lint.isEnabled(LintCategory.DEPRECATION) && !s.isDeprecatableViaAnnotation()) { 3872 if (!syms.deprecatedType.isErroneous() && s.attribute(syms.deprecatedType.tsym) != null) { 3873 log.warning(pos, 3874 LintWarnings.DeprecatedAnnotationHasNoEffect(Kinds.kindName(s))); 3875 } 3876 } 3877 } 3878 3879 void checkDeprecated(final DiagnosticPosition pos, final Symbol other, final Symbol s) { 3880 checkDeprecated(() -> pos, other, s); 3881 } 3882 3883 void checkDeprecated(Supplier<DiagnosticPosition> pos, final Symbol other, final Symbol s) { 3884 if ( (s.isDeprecatedForRemoval() 3885 || s.isDeprecated() && !other.isDeprecated()) 3886 && (s.outermostClass() != other.outermostClass() || s.outermostClass() == null) 3887 && s.kind != Kind.PCK) { 3888 deferredLintHandler.report(_l -> warnDeprecated(pos.get(), s)); 3889 } 3890 } 3891 3892 void checkSunAPI(final DiagnosticPosition pos, final Symbol s) { 3893 if ((s.flags() & PROPRIETARY) != 0) { 3894 deferredLintHandler.report(_l -> { 3895 log.mandatoryWarning(pos, Warnings.SunProprietary(s)); 3896 }); 3897 } 3898 } 3899 3900 void checkProfile(final DiagnosticPosition pos, final Symbol s) { 3901 if (profile != Profile.DEFAULT && (s.flags() & NOT_IN_PROFILE) != 0) { 3902 log.error(pos, Errors.NotInProfile(s, profile)); 3903 } 3904 } 3905 3906 void checkPreview(DiagnosticPosition pos, Symbol other, Symbol s) { 3907 checkPreview(pos, other, Type.noType, s); 3908 } 3909 3910 void checkPreview(DiagnosticPosition pos, Symbol other, Type site, Symbol s) { 3911 boolean sIsPreview; 3912 Symbol previewSymbol; 3913 if ((s.flags() & PREVIEW_API) != 0) { 3914 sIsPreview = true; 3915 previewSymbol= s; 3916 } else if ((s.kind == Kind.MTH || s.kind == Kind.VAR) && 3917 site.tsym != null && 3918 (site.tsym.flags() & PREVIEW_API) == 0 && 3919 (s.owner.flags() & PREVIEW_API) != 0) { 3920 //calling a method, or using a field, whose owner is a preview, but 3921 //using a site that is not a preview. Also produce an error or warning: 3922 sIsPreview = true; 3923 previewSymbol = s.owner; 3924 } else { 3925 sIsPreview = false; 3926 previewSymbol = null; 3927 } 3928 if (sIsPreview && !preview.participatesInPreview(syms, other, s) && !disablePreviewCheck) { 3929 if ((previewSymbol.flags() & PREVIEW_REFLECTIVE) == 0) { 3930 if (!preview.isEnabled()) { 3931 log.error(pos, Errors.IsPreview(s)); 3932 } else { 3933 preview.markUsesPreview(pos); 3934 deferredLintHandler.report(_l -> warnPreviewAPI(pos, LintWarnings.IsPreview(s))); 3935 } 3936 } else { 3937 deferredLintHandler.report(_l -> warnPreviewAPI(pos, LintWarnings.IsPreviewReflective(s))); 3938 } 3939 } 3940 if (preview.declaredUsingPreviewFeature(s)) { 3941 if (preview.isEnabled()) { 3942 //for preview disabled do presumably so not need to do anything? 3943 //If "s" is compiled from source, then there was an error for it already; 3944 //if "s" is from classfile, there already was an error for the classfile. 3945 preview.markUsesPreview(pos); 3946 deferredLintHandler.report(_l -> warnDeclaredUsingPreview(pos, s)); 3947 } 3948 } 3949 } 3950 3951 void checkRestricted(DiagnosticPosition pos, Symbol s) { 3952 if (s.kind == MTH && (s.flags() & RESTRICTED) != 0) { 3953 deferredLintHandler.report(_l -> warnRestrictedAPI(pos, s)); 3954 } 3955 } 3956 3957 /* ************************************************************************* 3958 * Check for recursive annotation elements. 3959 **************************************************************************/ 3960 3961 /** Check for cycles in the graph of annotation elements. 3962 */ 3963 void checkNonCyclicElements(JCClassDecl tree) { 3964 if ((tree.sym.flags_field & ANNOTATION) == 0) return; 3965 Assert.check((tree.sym.flags_field & LOCKED) == 0); 3966 try { 3967 tree.sym.flags_field |= LOCKED; 3968 for (JCTree def : tree.defs) { 3969 if (!def.hasTag(METHODDEF)) continue; 3970 JCMethodDecl meth = (JCMethodDecl)def; 3971 checkAnnotationResType(meth.pos(), meth.restype.type); 3972 } 3973 } finally { 3974 tree.sym.flags_field &= ~LOCKED; 3975 tree.sym.flags_field |= ACYCLIC_ANN; 3976 } 3977 } 3978 3979 void checkNonCyclicElementsInternal(DiagnosticPosition pos, TypeSymbol tsym) { 3980 if ((tsym.flags_field & ACYCLIC_ANN) != 0) 3981 return; 3982 if ((tsym.flags_field & LOCKED) != 0) { 3983 log.error(pos, Errors.CyclicAnnotationElement(tsym)); 3984 return; 3985 } 3986 try { 3987 tsym.flags_field |= LOCKED; 3988 for (Symbol s : tsym.members().getSymbols(NON_RECURSIVE)) { 3989 if (s.kind != MTH) 3990 continue; 3991 checkAnnotationResType(pos, ((MethodSymbol)s).type.getReturnType()); 3992 } 3993 } finally { 3994 tsym.flags_field &= ~LOCKED; 3995 tsym.flags_field |= ACYCLIC_ANN; 3996 } 3997 } 3998 3999 void checkAnnotationResType(DiagnosticPosition pos, Type type) { 4000 switch (type.getTag()) { 4001 case CLASS: 4002 if ((type.tsym.flags() & ANNOTATION) != 0) 4003 checkNonCyclicElementsInternal(pos, type.tsym); 4004 break; 4005 case ARRAY: 4006 checkAnnotationResType(pos, types.elemtype(type)); 4007 break; 4008 default: 4009 break; // int etc 4010 } 4011 } 4012 4013 /* ************************************************************************* 4014 * Check for cycles in the constructor call graph. 4015 **************************************************************************/ 4016 4017 /** Check for cycles in the graph of constructors calling other 4018 * constructors. 4019 */ 4020 void checkCyclicConstructors(JCClassDecl tree) { 4021 // use LinkedHashMap so we generate errors deterministically 4022 Map<Symbol,Symbol> callMap = new LinkedHashMap<>(); 4023 4024 // enter each constructor this-call into the map 4025 for (List<JCTree> l = tree.defs; l.nonEmpty(); l = l.tail) { 4026 if (!TreeInfo.isConstructor(l.head)) 4027 continue; 4028 JCMethodDecl meth = (JCMethodDecl)l.head; 4029 JCMethodInvocation app = TreeInfo.findConstructorCall(meth); 4030 if (app != null && TreeInfo.name(app.meth) == names._this) { 4031 callMap.put(meth.sym, TreeInfo.symbol(app.meth)); 4032 } else { 4033 meth.sym.flags_field |= ACYCLIC; 4034 } 4035 } 4036 4037 // Check for cycles in the map 4038 Symbol[] ctors = new Symbol[0]; 4039 ctors = callMap.keySet().toArray(ctors); 4040 for (Symbol caller : ctors) { 4041 checkCyclicConstructor(tree, caller, callMap); 4042 } 4043 } 4044 4045 /** Look in the map to see if the given constructor is part of a 4046 * call cycle. 4047 */ 4048 private void checkCyclicConstructor(JCClassDecl tree, Symbol ctor, 4049 Map<Symbol,Symbol> callMap) { 4050 if (ctor != null && (ctor.flags_field & ACYCLIC) == 0) { 4051 if ((ctor.flags_field & LOCKED) != 0) { 4052 log.error(TreeInfo.diagnosticPositionFor(ctor, tree, false, t -> t.hasTag(IDENT)), 4053 Errors.RecursiveCtorInvocation); 4054 } else { 4055 ctor.flags_field |= LOCKED; 4056 checkCyclicConstructor(tree, callMap.remove(ctor), callMap); 4057 ctor.flags_field &= ~LOCKED; 4058 } 4059 ctor.flags_field |= ACYCLIC; 4060 } 4061 } 4062 4063 /* ************************************************************************* 4064 * Verify the proper placement of super()/this() calls. 4065 * 4066 * - super()/this() may only appear in constructors 4067 * - There must be at most one super()/this() call per constructor 4068 * - The super()/this() call, if any, must be a top-level statement in the 4069 * constructor, i.e., not nested inside any other statement or block 4070 * - There must be no return statements prior to the super()/this() call 4071 **************************************************************************/ 4072 4073 void checkSuperInitCalls(JCClassDecl tree) { 4074 new SuperThisChecker().check(tree); 4075 } 4076 4077 private class SuperThisChecker extends TreeScanner { 4078 4079 // Match this scan stack: 1=JCMethodDecl, 2=JCExpressionStatement, 3=JCMethodInvocation 4080 private static final int MATCH_SCAN_DEPTH = 3; 4081 4082 private boolean constructor; // is this method a constructor? 4083 private boolean firstStatement; // at the first statement in method? 4084 private JCReturn earlyReturn; // first return prior to the super()/init(), if any 4085 private Name initCall; // whichever of "super" or "init" we've seen already 4086 private int scanDepth; // current scan recursion depth in method body 4087 4088 public void check(JCClassDecl classDef) { 4089 scan(classDef.defs); 4090 } 4091 4092 @Override 4093 public void visitMethodDef(JCMethodDecl tree) { 4094 Assert.check(!constructor); 4095 Assert.check(earlyReturn == null); 4096 Assert.check(initCall == null); 4097 Assert.check(scanDepth == 1); 4098 4099 // Initialize state for this method 4100 constructor = TreeInfo.isConstructor(tree); 4101 try { 4102 4103 // Scan method body 4104 if (tree.body != null) { 4105 firstStatement = true; 4106 for (List<JCStatement> l = tree.body.stats; l.nonEmpty(); l = l.tail) { 4107 scan(l.head); 4108 firstStatement = false; 4109 } 4110 } 4111 4112 // Verify no 'return' seen prior to an explicit super()/this() call 4113 if (constructor && earlyReturn != null && initCall != null) 4114 log.error(earlyReturn.pos(), Errors.ReturnBeforeSuperclassInitialized); 4115 } finally { 4116 firstStatement = false; 4117 constructor = false; 4118 earlyReturn = null; 4119 initCall = null; 4120 } 4121 } 4122 4123 @Override 4124 public void scan(JCTree tree) { 4125 scanDepth++; 4126 try { 4127 super.scan(tree); 4128 } finally { 4129 scanDepth--; 4130 } 4131 } 4132 4133 @Override 4134 public void visitApply(JCMethodInvocation apply) { 4135 do { 4136 4137 // Is this a super() or this() call? 4138 Name methodName = TreeInfo.name(apply.meth); 4139 if (methodName != names._super && methodName != names._this) 4140 break; 4141 4142 // super()/this() calls must only appear in a constructor 4143 if (!constructor) { 4144 log.error(apply.pos(), Errors.CallMustOnlyAppearInCtor); 4145 break; 4146 } 4147 4148 // super()/this() calls must be a top level statement 4149 if (scanDepth != MATCH_SCAN_DEPTH) { 4150 log.error(apply.pos(), Errors.CtorCallsNotAllowedHere); 4151 break; 4152 } 4153 4154 // super()/this() calls must not appear more than once 4155 if (initCall != null) { 4156 log.error(apply.pos(), Errors.RedundantSuperclassInit); 4157 break; 4158 } 4159 4160 // If super()/this() isn't first, require flexible constructors feature 4161 if (!firstStatement) 4162 preview.checkSourceLevel(apply.pos(), Feature.FLEXIBLE_CONSTRUCTORS); 4163 4164 // We found a legitimate super()/this() call; remember it 4165 initCall = methodName; 4166 } while (false); 4167 4168 // Proceed 4169 super.visitApply(apply); 4170 } 4171 4172 @Override 4173 public void visitReturn(JCReturn tree) { 4174 if (constructor && initCall == null && earlyReturn == null) 4175 earlyReturn = tree; // we have seen a return but not (yet) a super()/this() 4176 super.visitReturn(tree); 4177 } 4178 4179 @Override 4180 public void visitClassDef(JCClassDecl tree) { 4181 // don't descend any further 4182 } 4183 4184 @Override 4185 public void visitLambda(JCLambda tree) { 4186 final boolean constructorPrev = constructor; 4187 final boolean firstStatementPrev = firstStatement; 4188 final JCReturn earlyReturnPrev = earlyReturn; 4189 final Name initCallPrev = initCall; 4190 final int scanDepthPrev = scanDepth; 4191 constructor = false; 4192 firstStatement = false; 4193 earlyReturn = null; 4194 initCall = null; 4195 scanDepth = 0; 4196 try { 4197 super.visitLambda(tree); 4198 } finally { 4199 constructor = constructorPrev; 4200 firstStatement = firstStatementPrev; 4201 earlyReturn = earlyReturnPrev; 4202 initCall = initCallPrev; 4203 scanDepth = scanDepthPrev; 4204 } 4205 } 4206 } 4207 4208 /* ************************************************************************* 4209 * Miscellaneous 4210 **************************************************************************/ 4211 4212 /** 4213 * Check for division by integer constant zero 4214 * @param pos Position for error reporting. 4215 * @param operator The operator for the expression 4216 * @param operand The right hand operand for the expression 4217 */ 4218 void checkDivZero(final DiagnosticPosition pos, Symbol operator, Type operand) { 4219 if (operand.constValue() != null 4220 && operand.getTag().isSubRangeOf(LONG) 4221 && ((Number) (operand.constValue())).longValue() == 0) { 4222 int opc = ((OperatorSymbol)operator).opcode; 4223 if (opc == ByteCodes.idiv || opc == ByteCodes.imod 4224 || opc == ByteCodes.ldiv || opc == ByteCodes.lmod) { 4225 deferredLintHandler.report(_ -> lint.logIfEnabled(pos, LintWarnings.DivZero)); 4226 } 4227 } 4228 } 4229 4230 /** 4231 * Check for possible loss of precission 4232 * @param pos Position for error reporting. 4233 * @param found The computed type of the tree 4234 * @param req The computed type of the tree 4235 */ 4236 void checkLossOfPrecision(final DiagnosticPosition pos, Type found, Type req) { 4237 if (found.isNumeric() && req.isNumeric() && !types.isAssignable(found, req)) { 4238 deferredLintHandler.report(_ -> 4239 lint.logIfEnabled(pos, LintWarnings.PossibleLossOfPrecision(found, req))); 4240 } 4241 } 4242 4243 /** 4244 * Check for empty statements after if 4245 */ 4246 void checkEmptyIf(JCIf tree) { 4247 if (tree.thenpart.hasTag(SKIP) && tree.elsepart == null) { 4248 lint.logIfEnabled(tree.thenpart.pos(), LintWarnings.EmptyIf); 4249 } 4250 } 4251 4252 /** Check that symbol is unique in given scope. 4253 * @param pos Position for error reporting. 4254 * @param sym The symbol. 4255 * @param s The scope. 4256 */ 4257 boolean checkUnique(DiagnosticPosition pos, Symbol sym, Scope s) { 4258 if (sym.type.isErroneous()) 4259 return true; 4260 if (sym.owner.name == names.any) return false; 4261 for (Symbol byName : s.getSymbolsByName(sym.name, NON_RECURSIVE)) { 4262 if (sym != byName && 4263 (byName.flags() & CLASH) == 0 && 4264 sym.kind == byName.kind && 4265 sym.name != names.error && 4266 (sym.kind != MTH || 4267 types.hasSameArgs(sym.type, byName.type) || 4268 types.hasSameArgs(types.erasure(sym.type), types.erasure(byName.type)))) { 4269 if ((sym.flags() & VARARGS) != (byName.flags() & VARARGS)) { 4270 sym.flags_field |= CLASH; 4271 varargsDuplicateError(pos, sym, byName); 4272 return true; 4273 } else if (sym.kind == MTH && !types.hasSameArgs(sym.type, byName.type, false)) { 4274 duplicateErasureError(pos, sym, byName); 4275 sym.flags_field |= CLASH; 4276 return true; 4277 } else if ((sym.flags() & MATCH_BINDING) != 0 && 4278 (byName.flags() & MATCH_BINDING) != 0 && 4279 (byName.flags() & MATCH_BINDING_TO_OUTER) == 0) { 4280 if (!sym.type.isErroneous()) { 4281 log.error(pos, Errors.MatchBindingExists); 4282 sym.flags_field |= CLASH; 4283 } 4284 return false; 4285 } else { 4286 duplicateError(pos, byName); 4287 return false; 4288 } 4289 } 4290 } 4291 return true; 4292 } 4293 4294 /** Report duplicate declaration error. 4295 */ 4296 void duplicateErasureError(DiagnosticPosition pos, Symbol sym1, Symbol sym2) { 4297 if (!sym1.type.isErroneous() && !sym2.type.isErroneous()) { 4298 log.error(pos, Errors.NameClashSameErasure(sym1, sym2)); 4299 } 4300 } 4301 4302 /**Check that types imported through the ordinary imports don't clash with types imported 4303 * by other (static or ordinary) imports. Note that two static imports may import two clashing 4304 * types without an error on the imports. 4305 * @param toplevel The toplevel tree for which the test should be performed. 4306 */ 4307 void checkImportsUnique(JCCompilationUnit toplevel) { 4308 WriteableScope ordinallyImportedSoFar = WriteableScope.create(toplevel.packge); 4309 WriteableScope staticallyImportedSoFar = WriteableScope.create(toplevel.packge); 4310 WriteableScope topLevelScope = toplevel.toplevelScope; 4311 4312 for (JCTree def : toplevel.defs) { 4313 if (!def.hasTag(IMPORT)) 4314 continue; 4315 4316 JCImport imp = (JCImport) def; 4317 4318 if (imp.importScope == null) 4319 continue; 4320 4321 for (Symbol sym : imp.importScope.getSymbols(sym -> sym.kind == TYP)) { 4322 if (imp.isStatic()) { 4323 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, true); 4324 staticallyImportedSoFar.enter(sym); 4325 } else { 4326 checkUniqueImport(imp.pos(), ordinallyImportedSoFar, staticallyImportedSoFar, topLevelScope, sym, false); 4327 ordinallyImportedSoFar.enter(sym); 4328 } 4329 } 4330 4331 imp.importScope = null; 4332 } 4333 } 4334 4335 /** Check that single-type import is not already imported or top-level defined, 4336 * but make an exception for two single-type imports which denote the same type. 4337 * @param pos Position for error reporting. 4338 * @param ordinallyImportedSoFar A Scope containing types imported so far through 4339 * ordinary imports. 4340 * @param staticallyImportedSoFar A Scope containing types imported so far through 4341 * static imports. 4342 * @param topLevelScope The current file's top-level Scope 4343 * @param sym The symbol. 4344 * @param staticImport Whether or not this was a static import 4345 */ 4346 private boolean checkUniqueImport(DiagnosticPosition pos, Scope ordinallyImportedSoFar, 4347 Scope staticallyImportedSoFar, Scope topLevelScope, 4348 Symbol sym, boolean staticImport) { 4349 Predicate<Symbol> duplicates = candidate -> candidate != sym && !candidate.type.isErroneous(); 4350 Symbol ordinaryClashing = ordinallyImportedSoFar.findFirst(sym.name, duplicates); 4351 Symbol staticClashing = null; 4352 if (ordinaryClashing == null && !staticImport) { 4353 staticClashing = staticallyImportedSoFar.findFirst(sym.name, duplicates); 4354 } 4355 if (ordinaryClashing != null || staticClashing != null) { 4356 if (ordinaryClashing != null) 4357 log.error(pos, Errors.AlreadyDefinedSingleImport(ordinaryClashing)); 4358 else 4359 log.error(pos, Errors.AlreadyDefinedStaticSingleImport(staticClashing)); 4360 return false; 4361 } 4362 Symbol clashing = topLevelScope.findFirst(sym.name, duplicates); 4363 if (clashing != null) { 4364 log.error(pos, Errors.AlreadyDefinedThisUnit(clashing)); 4365 return false; 4366 } 4367 return true; 4368 } 4369 4370 /** Check that a qualified name is in canonical form (for import decls). 4371 */ 4372 public void checkCanonical(JCTree tree) { 4373 if (!isCanonical(tree)) 4374 log.error(tree.pos(), 4375 Errors.ImportRequiresCanonical(TreeInfo.symbol(tree))); 4376 } 4377 // where 4378 private boolean isCanonical(JCTree tree) { 4379 while (tree.hasTag(SELECT)) { 4380 JCFieldAccess s = (JCFieldAccess) tree; 4381 if (s.sym.owner.getQualifiedName() != TreeInfo.symbol(s.selected).getQualifiedName()) 4382 return false; 4383 tree = s.selected; 4384 } 4385 return true; 4386 } 4387 4388 /** Check that an auxiliary class is not accessed from any other file than its own. 4389 */ 4390 void checkForBadAuxiliaryClassAccess(DiagnosticPosition pos, Env<AttrContext> env, ClassSymbol c) { 4391 if ((c.flags() & AUXILIARY) != 0 && 4392 rs.isAccessible(env, c) && 4393 !fileManager.isSameFile(c.sourcefile, env.toplevel.sourcefile)) 4394 { 4395 lint.logIfEnabled(pos, 4396 LintWarnings.AuxiliaryClassAccessedFromOutsideOfItsSourceFile(c, c.sourcefile)); 4397 } 4398 } 4399 4400 /** 4401 * Check for a default constructor in an exported package. 4402 */ 4403 void checkDefaultConstructor(ClassSymbol c, DiagnosticPosition pos) { 4404 if (lint.isEnabled(LintCategory.MISSING_EXPLICIT_CTOR) && 4405 ((c.flags() & (ENUM | RECORD)) == 0) && 4406 !c.isAnonymous() && 4407 ((c.flags() & (PUBLIC | PROTECTED)) != 0) && 4408 Feature.MODULES.allowedInSource(source)) { 4409 NestingKind nestingKind = c.getNestingKind(); 4410 switch (nestingKind) { 4411 case ANONYMOUS, 4412 LOCAL -> {return;} 4413 case TOP_LEVEL -> {;} // No additional checks needed 4414 case MEMBER -> { 4415 // For nested member classes, all the enclosing 4416 // classes must be public or protected. 4417 Symbol owner = c.owner; 4418 while (owner != null && owner.kind == TYP) { 4419 if ((owner.flags() & (PUBLIC | PROTECTED)) == 0) 4420 return; 4421 owner = owner.owner; 4422 } 4423 } 4424 } 4425 4426 // Only check classes in named packages exported by its module 4427 PackageSymbol pkg = c.packge(); 4428 if (!pkg.isUnnamed()) { 4429 ModuleSymbol modle = pkg.modle; 4430 for (ExportsDirective exportDir : modle.exports) { 4431 // Report warning only if the containing 4432 // package is unconditionally exported 4433 if (exportDir.packge.equals(pkg)) { 4434 if (exportDir.modules == null || exportDir.modules.isEmpty()) { 4435 // Warning may be suppressed by 4436 // annotations; check again for being 4437 // enabled in the deferred context. 4438 deferredLintHandler.report(_ -> 4439 lint.logIfEnabled(pos, LintWarnings.MissingExplicitCtor(c, pkg, modle))); 4440 } else { 4441 return; 4442 } 4443 } 4444 } 4445 } 4446 } 4447 return; 4448 } 4449 4450 private class ConversionWarner extends Warner { 4451 final String uncheckedKey; 4452 final Type found; 4453 final Type expected; 4454 public ConversionWarner(DiagnosticPosition pos, String uncheckedKey, Type found, Type expected) { 4455 super(pos); 4456 this.uncheckedKey = uncheckedKey; 4457 this.found = found; 4458 this.expected = expected; 4459 } 4460 4461 @Override 4462 public void warn(LintCategory lint) { 4463 boolean warned = this.warned; 4464 super.warn(lint); 4465 if (warned) return; // suppress redundant diagnostics 4466 switch (lint) { 4467 case UNCHECKED: 4468 Check.this.warnUnchecked(pos(), LintWarnings.ProbFoundReq(diags.fragment(uncheckedKey), found, expected)); 4469 break; 4470 case VARARGS: 4471 if (method != null && 4472 method.attribute(syms.trustMeType.tsym) != null && 4473 isTrustMeAllowedOnMethod(method) && 4474 !types.isReifiable(method.type.getParameterTypes().last())) { 4475 Check.this.lint.logIfEnabled(pos(), LintWarnings.VarargsUnsafeUseVarargsParam(method.params.last())); 4476 } 4477 break; 4478 default: 4479 throw new AssertionError("Unexpected lint: " + lint); 4480 } 4481 } 4482 } 4483 4484 public Warner castWarner(DiagnosticPosition pos, Type found, Type expected) { 4485 return new ConversionWarner(pos, "unchecked.cast.to.type", found, expected); 4486 } 4487 4488 public Warner convertWarner(DiagnosticPosition pos, Type found, Type expected) { 4489 return new ConversionWarner(pos, "unchecked.assign", found, expected); 4490 } 4491 4492 public void checkFunctionalInterface(JCClassDecl tree, ClassSymbol cs) { 4493 Compound functionalType = cs.attribute(syms.functionalInterfaceType.tsym); 4494 4495 if (functionalType != null) { 4496 try { 4497 types.findDescriptorSymbol((TypeSymbol)cs); 4498 } catch (Types.FunctionDescriptorLookupError ex) { 4499 DiagnosticPosition pos = tree.pos(); 4500 for (JCAnnotation a : tree.getModifiers().annotations) { 4501 if (a.annotationType.type.tsym == syms.functionalInterfaceType.tsym) { 4502 pos = a.pos(); 4503 break; 4504 } 4505 } 4506 log.error(pos, Errors.BadFunctionalIntfAnno1(ex.getDiagnostic())); 4507 } 4508 } 4509 } 4510 4511 public void checkImportsResolvable(final JCCompilationUnit toplevel) { 4512 for (final JCImportBase impBase : toplevel.getImports()) { 4513 if (!(impBase instanceof JCImport imp)) 4514 continue; 4515 if (!imp.staticImport || !imp.qualid.hasTag(SELECT)) 4516 continue; 4517 final JCFieldAccess select = imp.qualid; 4518 final Symbol origin; 4519 if (select.name == names.asterisk || (origin = TreeInfo.symbol(select.selected)) == null || origin.kind != TYP) 4520 continue; 4521 4522 TypeSymbol site = (TypeSymbol) TreeInfo.symbol(select.selected); 4523 if (!checkTypeContainsImportableElement(site, site, toplevel.packge, select.name, new HashSet<Symbol>())) { 4524 log.error(imp.pos(), 4525 Errors.CantResolveLocation(KindName.STATIC, 4526 select.name, 4527 null, 4528 null, 4529 Fragments.Location(kindName(site), 4530 site, 4531 null))); 4532 } 4533 } 4534 } 4535 4536 // Check that packages imported are in scope (JLS 7.4.3, 6.3, 6.5.3.1, 6.5.3.2) 4537 public void checkImportedPackagesObservable(final JCCompilationUnit toplevel) { 4538 OUTER: for (JCImportBase impBase : toplevel.getImports()) { 4539 if (impBase instanceof JCImport imp && !imp.staticImport && 4540 TreeInfo.name(imp.qualid) == names.asterisk) { 4541 TypeSymbol tsym = imp.qualid.selected.type.tsym; 4542 if (tsym.kind == PCK && tsym.members().isEmpty() && 4543 !(Feature.IMPORT_ON_DEMAND_OBSERVABLE_PACKAGES.allowedInSource(source) && tsym.exists())) { 4544 log.error(DiagnosticFlag.RESOLVE_ERROR, imp.qualid.selected.pos(), Errors.DoesntExist(tsym)); 4545 } 4546 } 4547 } 4548 } 4549 4550 private boolean checkTypeContainsImportableElement(TypeSymbol tsym, TypeSymbol origin, PackageSymbol packge, Name name, Set<Symbol> processed) { 4551 if (tsym == null || !processed.add(tsym)) 4552 return false; 4553 4554 // also search through inherited names 4555 if (checkTypeContainsImportableElement(types.supertype(tsym.type).tsym, origin, packge, name, processed)) 4556 return true; 4557 4558 for (Type t : types.interfaces(tsym.type)) 4559 if (checkTypeContainsImportableElement(t.tsym, origin, packge, name, processed)) 4560 return true; 4561 4562 for (Symbol sym : tsym.members().getSymbolsByName(name)) { 4563 if (sym.isStatic() && 4564 importAccessible(sym, packge) && 4565 sym.isMemberOf(origin, types)) { 4566 return true; 4567 } 4568 } 4569 4570 return false; 4571 } 4572 4573 // is the sym accessible everywhere in packge? 4574 public boolean importAccessible(Symbol sym, PackageSymbol packge) { 4575 try { 4576 int flags = (int)(sym.flags() & AccessFlags); 4577 switch (flags) { 4578 default: 4579 case PUBLIC: 4580 return true; 4581 case PRIVATE: 4582 return false; 4583 case 0: 4584 case PROTECTED: 4585 return sym.packge() == packge; 4586 } 4587 } catch (ClassFinder.BadClassFile err) { 4588 throw err; 4589 } catch (CompletionFailure ex) { 4590 return false; 4591 } 4592 } 4593 4594 public void checkLeaksNotAccessible(Env<AttrContext> env, JCClassDecl check) { 4595 JCCompilationUnit toplevel = env.toplevel; 4596 4597 if ( toplevel.modle == syms.unnamedModule 4598 || toplevel.modle == syms.noModule 4599 || (check.sym.flags() & COMPOUND) != 0) { 4600 return ; 4601 } 4602 4603 ExportsDirective currentExport = findExport(toplevel.packge); 4604 4605 if ( currentExport == null //not exported 4606 || currentExport.modules != null) //don't check classes in qualified export 4607 return ; 4608 4609 new TreeScanner() { 4610 Lint lint = env.info.lint; 4611 boolean inSuperType; 4612 4613 @Override 4614 public void visitBlock(JCBlock tree) { 4615 } 4616 @Override 4617 public void visitMethodDef(JCMethodDecl tree) { 4618 if (!isAPISymbol(tree.sym)) 4619 return; 4620 Lint prevLint = lint; 4621 try { 4622 lint = lint.augment(tree.sym); 4623 if (lint.isEnabled(LintCategory.EXPORTS)) { 4624 super.visitMethodDef(tree); 4625 } 4626 } finally { 4627 lint = prevLint; 4628 } 4629 } 4630 @Override 4631 public void visitVarDef(JCVariableDecl tree) { 4632 if (!isAPISymbol(tree.sym) && tree.sym.owner.kind != MTH) 4633 return; 4634 Lint prevLint = lint; 4635 try { 4636 lint = lint.augment(tree.sym); 4637 if (lint.isEnabled(LintCategory.EXPORTS)) { 4638 scan(tree.mods); 4639 scan(tree.vartype); 4640 } 4641 } finally { 4642 lint = prevLint; 4643 } 4644 } 4645 @Override 4646 public void visitClassDef(JCClassDecl tree) { 4647 if (tree != check) 4648 return ; 4649 4650 if (!isAPISymbol(tree.sym)) 4651 return ; 4652 4653 Lint prevLint = lint; 4654 try { 4655 lint = lint.augment(tree.sym); 4656 if (lint.isEnabled(LintCategory.EXPORTS)) { 4657 scan(tree.mods); 4658 scan(tree.typarams); 4659 try { 4660 inSuperType = true; 4661 scan(tree.extending); 4662 scan(tree.implementing); 4663 } finally { 4664 inSuperType = false; 4665 } 4666 scan(tree.defs); 4667 } 4668 } finally { 4669 lint = prevLint; 4670 } 4671 } 4672 @Override 4673 public void visitTypeApply(JCTypeApply tree) { 4674 scan(tree.clazz); 4675 boolean oldInSuperType = inSuperType; 4676 try { 4677 inSuperType = false; 4678 scan(tree.arguments); 4679 } finally { 4680 inSuperType = oldInSuperType; 4681 } 4682 } 4683 @Override 4684 public void visitIdent(JCIdent tree) { 4685 Symbol sym = TreeInfo.symbol(tree); 4686 if (sym.kind == TYP && !sym.type.hasTag(TYPEVAR)) { 4687 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType); 4688 } 4689 } 4690 4691 @Override 4692 public void visitSelect(JCFieldAccess tree) { 4693 Symbol sym = TreeInfo.symbol(tree); 4694 Symbol sitesym = TreeInfo.symbol(tree.selected); 4695 if (sym.kind == TYP && sitesym.kind == PCK) { 4696 checkVisible(tree.pos(), sym, toplevel.packge, inSuperType); 4697 } else { 4698 super.visitSelect(tree); 4699 } 4700 } 4701 4702 @Override 4703 public void visitAnnotation(JCAnnotation tree) { 4704 if (tree.attribute.type.tsym.getAnnotation(java.lang.annotation.Documented.class) != null) 4705 super.visitAnnotation(tree); 4706 } 4707 4708 }.scan(check); 4709 } 4710 //where: 4711 private ExportsDirective findExport(PackageSymbol pack) { 4712 for (ExportsDirective d : pack.modle.exports) { 4713 if (d.packge == pack) 4714 return d; 4715 } 4716 4717 return null; 4718 } 4719 private boolean isAPISymbol(Symbol sym) { 4720 while (sym.kind != PCK) { 4721 if ((sym.flags() & Flags.PUBLIC) == 0 && (sym.flags() & Flags.PROTECTED) == 0) { 4722 return false; 4723 } 4724 sym = sym.owner; 4725 } 4726 return true; 4727 } 4728 private void checkVisible(DiagnosticPosition pos, Symbol what, PackageSymbol inPackage, boolean inSuperType) { 4729 if (!isAPISymbol(what) && !inSuperType) { //package private/private element 4730 log.warning(pos, LintWarnings.LeaksNotAccessible(kindName(what), what, what.packge().modle)); 4731 return ; 4732 } 4733 4734 PackageSymbol whatPackage = what.packge(); 4735 ExportsDirective whatExport = findExport(whatPackage); 4736 ExportsDirective inExport = findExport(inPackage); 4737 4738 if (whatExport == null) { //package not exported: 4739 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexported(kindName(what), what, what.packge().modle)); 4740 return ; 4741 } 4742 4743 if (whatExport.modules != null) { 4744 if (inExport.modules == null || !whatExport.modules.containsAll(inExport.modules)) { 4745 log.warning(pos, LintWarnings.LeaksNotAccessibleUnexportedQualified(kindName(what), what, what.packge().modle)); 4746 } 4747 } 4748 4749 if (whatPackage.modle != inPackage.modle && whatPackage.modle != syms.java_base) { 4750 //check that relativeTo.modle requires transitive what.modle, somehow: 4751 List<ModuleSymbol> todo = List.of(inPackage.modle); 4752 4753 while (todo.nonEmpty()) { 4754 ModuleSymbol current = todo.head; 4755 todo = todo.tail; 4756 if (current == whatPackage.modle) 4757 return ; //OK 4758 if ((current.flags() & Flags.AUTOMATIC_MODULE) != 0) 4759 continue; //for automatic modules, don't look into their dependencies 4760 for (RequiresDirective req : current.requires) { 4761 if (req.isTransitive()) { 4762 todo = todo.prepend(req.module); 4763 } 4764 } 4765 } 4766 4767 log.warning(pos, LintWarnings.LeaksNotAccessibleNotRequiredTransitive(kindName(what), what, what.packge().modle)); 4768 } 4769 } 4770 4771 void checkModuleExists(final DiagnosticPosition pos, ModuleSymbol msym) { 4772 if (msym.kind != MDL) { 4773 deferredLintHandler.report(_ -> 4774 lint.logIfEnabled(pos, LintWarnings.ModuleNotFound(msym))); 4775 } 4776 } 4777 4778 void checkPackageExistsForOpens(final DiagnosticPosition pos, PackageSymbol packge) { 4779 if (packge.members().isEmpty() && 4780 ((packge.flags() & Flags.HAS_RESOURCE) == 0)) { 4781 deferredLintHandler.report(_ -> 4782 lint.logIfEnabled(pos, LintWarnings.PackageEmptyOrNotFound(packge))); 4783 } 4784 } 4785 4786 void checkModuleRequires(final DiagnosticPosition pos, final RequiresDirective rd) { 4787 if ((rd.module.flags() & Flags.AUTOMATIC_MODULE) != 0) { 4788 deferredLintHandler.report(_ -> { 4789 if (rd.isTransitive() && lint.isEnabled(LintCategory.REQUIRES_TRANSITIVE_AUTOMATIC)) { 4790 log.warning(pos, LintWarnings.RequiresTransitiveAutomatic); 4791 } else { 4792 lint.logIfEnabled(pos, LintWarnings.RequiresAutomatic); 4793 } 4794 }); 4795 } 4796 } 4797 4798 /** 4799 * Verify the case labels conform to the constraints. Checks constraints related 4800 * combinations of patterns and other labels. 4801 * 4802 * @param cases the cases that should be checked. 4803 */ 4804 void checkSwitchCaseStructure(List<JCCase> cases) { 4805 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) { 4806 JCCase c = l.head; 4807 if (c.labels.head instanceof JCConstantCaseLabel constLabel) { 4808 if (TreeInfo.isNull(constLabel.expr)) { 4809 if (c.labels.tail.nonEmpty()) { 4810 if (c.labels.tail.head instanceof JCDefaultCaseLabel defLabel) { 4811 if (c.labels.tail.tail.nonEmpty()) { 4812 log.error(c.labels.tail.tail.head.pos(), Errors.InvalidCaseLabelCombination); 4813 } 4814 } else { 4815 log.error(c.labels.tail.head.pos(), Errors.InvalidCaseLabelCombination); 4816 } 4817 } 4818 } else { 4819 for (JCCaseLabel label : c.labels.tail) { 4820 if (!(label instanceof JCConstantCaseLabel) || TreeInfo.isNullCaseLabel(label)) { 4821 log.error(label.pos(), Errors.InvalidCaseLabelCombination); 4822 break; 4823 } 4824 } 4825 } 4826 } else if (c.labels.tail.nonEmpty()) { 4827 var patterCaseLabels = c.labels.stream().filter(ll -> ll instanceof JCPatternCaseLabel).map(cl -> (JCPatternCaseLabel)cl); 4828 var allUnderscore = patterCaseLabels.allMatch(pcl -> !hasBindings(pcl.getPattern())); 4829 4830 if (!allUnderscore) { 4831 log.error(c.labels.tail.head.pos(), Errors.FlowsThroughFromPattern); 4832 } 4833 4834 boolean allPatternCaseLabels = c.labels.stream().allMatch(p -> p instanceof JCPatternCaseLabel); 4835 4836 if (allPatternCaseLabels) { 4837 preview.checkSourceLevel(c.labels.tail.head.pos(), Feature.UNNAMED_VARIABLES); 4838 } 4839 4840 for (JCCaseLabel label : c.labels.tail) { 4841 if (label instanceof JCConstantCaseLabel) { 4842 log.error(label.pos(), Errors.InvalidCaseLabelCombination); 4843 break; 4844 } 4845 } 4846 } 4847 } 4848 4849 boolean isCaseStatementGroup = cases.nonEmpty() && 4850 cases.head.caseKind == CaseTree.CaseKind.STATEMENT; 4851 4852 if (isCaseStatementGroup) { 4853 boolean previousCompletessNormally = false; 4854 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) { 4855 JCCase c = l.head; 4856 if (previousCompletessNormally && 4857 c.stats.nonEmpty() && 4858 c.labels.head instanceof JCPatternCaseLabel patternLabel && 4859 (hasBindings(patternLabel.pat) || hasBindings(c.guard))) { 4860 log.error(c.labels.head.pos(), Errors.FlowsThroughToPattern); 4861 } else if (c.stats.isEmpty() && 4862 c.labels.head instanceof JCPatternCaseLabel patternLabel && 4863 (hasBindings(patternLabel.pat) || hasBindings(c.guard)) && 4864 hasStatements(l.tail)) { 4865 log.error(c.labels.head.pos(), Errors.FlowsThroughFromPattern); 4866 } 4867 previousCompletessNormally = c.completesNormally; 4868 } 4869 } 4870 } 4871 4872 boolean hasBindings(JCTree p) { 4873 boolean[] bindings = new boolean[1]; 4874 4875 new TreeScanner() { 4876 @Override 4877 public void visitBindingPattern(JCBindingPattern tree) { 4878 bindings[0] = !tree.var.sym.isUnnamedVariable(); 4879 super.visitBindingPattern(tree); 4880 } 4881 }.scan(p); 4882 4883 return bindings[0]; 4884 } 4885 4886 boolean hasStatements(List<JCCase> cases) { 4887 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) { 4888 if (l.head.stats.nonEmpty()) { 4889 return true; 4890 } 4891 } 4892 4893 return false; 4894 } 4895 void checkSwitchCaseLabelDominated(JCCaseLabel unconditionalCaseLabel, List<JCCase> cases) { 4896 List<Pair<JCCase, JCCaseLabel>> caseLabels = List.nil(); 4897 boolean seenDefault = false; 4898 boolean seenDefaultLabel = false; 4899 boolean warnDominatedByDefault = false; 4900 boolean unconditionalFound = false; 4901 4902 for (List<JCCase> l = cases; l.nonEmpty(); l = l.tail) { 4903 JCCase c = l.head; 4904 for (JCCaseLabel label : c.labels) { 4905 if (label.hasTag(DEFAULTCASELABEL)) { 4906 seenDefault = true; 4907 seenDefaultLabel |= 4908 TreeInfo.isNullCaseLabel(c.labels.head); 4909 continue; 4910 } 4911 if (TreeInfo.isNullCaseLabel(label)) { 4912 if (seenDefault) { 4913 log.error(label.pos(), Errors.PatternDominated); 4914 } 4915 continue; 4916 } 4917 if (seenDefault && !warnDominatedByDefault) { 4918 if (label.hasTag(PATTERNCASELABEL) || 4919 (label instanceof JCConstantCaseLabel && seenDefaultLabel)) { 4920 log.error(label.pos(), Errors.PatternDominated); 4921 warnDominatedByDefault = true; 4922 } 4923 } 4924 Type currentType = labelType(label); 4925 for (Pair<JCCase, JCCaseLabel> caseAndLabel : caseLabels) { 4926 JCCase testCase = caseAndLabel.fst; 4927 JCCaseLabel testCaseLabel = caseAndLabel.snd; 4928 Type testType = labelType(testCaseLabel); 4929 boolean dominated = false; 4930 if (types.isUnconditionallyExact(currentType, testType) && 4931 !currentType.hasTag(ERROR) && !testType.hasTag(ERROR)) { 4932 //the current label is potentially dominated by the existing (test) label, check: 4933 if (label instanceof JCConstantCaseLabel) { 4934 dominated |= !(testCaseLabel instanceof JCConstantCaseLabel) && 4935 TreeInfo.unguardedCase(testCase); 4936 } else if (label instanceof JCPatternCaseLabel patternCL && 4937 testCaseLabel instanceof JCPatternCaseLabel testPatternCaseLabel && 4938 (testCase.equals(c) || TreeInfo.unguardedCase(testCase))) { 4939 dominated = patternDominated(testPatternCaseLabel.pat, 4940 patternCL.pat); 4941 } 4942 } 4943 4944 if (dominated) { 4945 log.error(label.pos(), Errors.PatternDominated); 4946 } 4947 } 4948 caseLabels = caseLabels.prepend(Pair.of(c, label)); 4949 } 4950 } 4951 } 4952 //where: 4953 private Type labelType(JCCaseLabel label) { 4954 return types.erasure(switch (label.getTag()) { 4955 case PATTERNCASELABEL -> ((JCPatternCaseLabel) label).pat.type; 4956 case CONSTANTCASELABEL -> ((JCConstantCaseLabel) label).expr.type; 4957 default -> throw Assert.error("Unexpected tree kind: " + label.getTag()); 4958 }); 4959 } 4960 private boolean patternDominated(JCPattern existingPattern, JCPattern currentPattern) { 4961 Type existingPatternType = types.erasure(existingPattern.type); 4962 Type currentPatternType = types.erasure(currentPattern.type); 4963 if (!types.isUnconditionallyExact(currentPatternType, existingPatternType)) { 4964 return false; 4965 } 4966 if (currentPattern instanceof JCBindingPattern || 4967 currentPattern instanceof JCAnyPattern) { 4968 return existingPattern instanceof JCBindingPattern || 4969 existingPattern instanceof JCAnyPattern; 4970 } else if (currentPattern instanceof JCRecordPattern currentRecordPattern) { 4971 if (existingPattern instanceof JCBindingPattern || 4972 existingPattern instanceof JCAnyPattern) { 4973 return true; 4974 } else if (existingPattern instanceof JCRecordPattern existingRecordPattern) { 4975 List<JCPattern> existingNested = existingRecordPattern.nested; 4976 List<JCPattern> currentNested = currentRecordPattern.nested; 4977 if (existingNested.size() != currentNested.size()) { 4978 return false; 4979 } 4980 while (existingNested.nonEmpty()) { 4981 if (!patternDominated(existingNested.head, currentNested.head)) { 4982 return false; 4983 } 4984 existingNested = existingNested.tail; 4985 currentNested = currentNested.tail; 4986 } 4987 return true; 4988 } else { 4989 Assert.error("Unknown pattern: " + existingPattern.getTag()); 4990 } 4991 } else { 4992 Assert.error("Unknown pattern: " + currentPattern.getTag()); 4993 } 4994 return false; 4995 } 4996 4997 /** check if a type is a subtype of Externalizable, if that is available. */ 4998 boolean isExternalizable(Type t) { 4999 try { 5000 syms.externalizableType.complete(); 5001 } catch (CompletionFailure e) { 5002 return false; 5003 } 5004 return types.isSubtype(t, syms.externalizableType); 5005 } 5006 5007 /** 5008 * Check structure of serialization declarations. 5009 */ 5010 public void checkSerialStructure(Env<AttrContext> env, JCClassDecl tree, ClassSymbol c) { 5011 (new SerialTypeVisitor(env)).visit(c, tree); 5012 } 5013 5014 /** 5015 * This visitor will warn if a serialization-related field or 5016 * method is declared in a suspicious or incorrect way. In 5017 * particular, it will warn for cases where the runtime 5018 * serialization mechanism will silently ignore a mis-declared 5019 * entity. 5020 * 5021 * Distinguished serialization-related fields and methods: 5022 * 5023 * Methods: 5024 * 5025 * private void writeObject(ObjectOutputStream stream) throws IOException 5026 * ANY-ACCESS-MODIFIER Object writeReplace() throws ObjectStreamException 5027 * 5028 * private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException 5029 * private void readObjectNoData() throws ObjectStreamException 5030 * ANY-ACCESS-MODIFIER Object readResolve() throws ObjectStreamException 5031 * 5032 * Fields: 5033 * 5034 * private static final long serialVersionUID 5035 * private static final ObjectStreamField[] serialPersistentFields 5036 * 5037 * Externalizable: methods defined on the interface 5038 * public void writeExternal(ObjectOutput) throws IOException 5039 * public void readExternal(ObjectInput) throws IOException 5040 */ 5041 private class SerialTypeVisitor extends ElementKindVisitor14<Void, JCClassDecl> { 5042 Env<AttrContext> env; 5043 SerialTypeVisitor(Env<AttrContext> env) { 5044 this.lint = Check.this.lint; 5045 this.env = env; 5046 } 5047 5048 private static final Set<String> serialMethodNames = 5049 Set.of("writeObject", "writeReplace", 5050 "readObject", "readObjectNoData", 5051 "readResolve"); 5052 5053 private static final Set<String> serialFieldNames = 5054 Set.of("serialVersionUID", "serialPersistentFields"); 5055 5056 // Type of serialPersistentFields 5057 private final Type OSF_TYPE = new Type.ArrayType(syms.objectStreamFieldType, syms.arrayClass); 5058 5059 Lint lint; 5060 5061 @Override 5062 public Void defaultAction(Element e, JCClassDecl p) { 5063 throw new IllegalArgumentException(Objects.requireNonNullElse(e.toString(), "")); 5064 } 5065 5066 @Override 5067 public Void visitType(TypeElement e, JCClassDecl p) { 5068 runUnderLint(e, p, (symbol, param) -> super.visitType(symbol, param)); 5069 return null; 5070 } 5071 5072 @Override 5073 public Void visitTypeAsClass(TypeElement e, 5074 JCClassDecl p) { 5075 // Anonymous classes filtered out by caller. 5076 5077 ClassSymbol c = (ClassSymbol)e; 5078 5079 checkCtorAccess(p, c); 5080 5081 // Check for missing serialVersionUID; check *not* done 5082 // for enums or records. 5083 VarSymbol svuidSym = null; 5084 for (Symbol sym : c.members().getSymbolsByName(names.serialVersionUID)) { 5085 if (sym.kind == VAR) { 5086 svuidSym = (VarSymbol)sym; 5087 break; 5088 } 5089 } 5090 5091 if (svuidSym == null) { 5092 log.warning(p.pos(), LintWarnings.MissingSVUID(c)); 5093 } 5094 5095 // Check for serialPersistentFields to gate checks for 5096 // non-serializable non-transient instance fields 5097 boolean serialPersistentFieldsPresent = 5098 c.members() 5099 .getSymbolsByName(names.serialPersistentFields, sym -> sym.kind == VAR) 5100 .iterator() 5101 .hasNext(); 5102 5103 // Check declarations of serialization-related methods and 5104 // fields 5105 final boolean[] hasWriteReplace = {false}; 5106 for(Symbol el : c.getEnclosedElements()) { 5107 runUnderLint(el, p, (enclosed, tree) -> { 5108 String name = null; 5109 switch(enclosed.getKind()) { 5110 case FIELD -> { 5111 if (!serialPersistentFieldsPresent) { 5112 var flags = enclosed.flags(); 5113 if ( ((flags & TRANSIENT) == 0) && 5114 ((flags & STATIC) == 0)) { 5115 Type varType = enclosed.asType(); 5116 if (!canBeSerialized(varType)) { 5117 // Note per JLS arrays are 5118 // serializable even if the 5119 // component type is not. 5120 log.warning( 5121 TreeInfo.diagnosticPositionFor(enclosed, tree), 5122 LintWarnings.NonSerializableInstanceField); 5123 } else if (varType.hasTag(ARRAY)) { 5124 ArrayType arrayType = (ArrayType)varType; 5125 Type elementType = arrayType.elemtype; 5126 while (elementType.hasTag(ARRAY)) { 5127 arrayType = (ArrayType)elementType; 5128 elementType = arrayType.elemtype; 5129 } 5130 if (!canBeSerialized(elementType)) { 5131 log.warning( 5132 TreeInfo.diagnosticPositionFor(enclosed, tree), 5133 LintWarnings.NonSerializableInstanceFieldArray(elementType)); 5134 } 5135 } 5136 } 5137 } 5138 5139 name = enclosed.getSimpleName().toString(); 5140 if (serialFieldNames.contains(name)) { 5141 VarSymbol field = (VarSymbol)enclosed; 5142 switch (name) { 5143 case "serialVersionUID" -> checkSerialVersionUID(tree, e, field); 5144 case "serialPersistentFields" -> checkSerialPersistentFields(tree, e, field); 5145 default -> throw new AssertionError(); 5146 } 5147 } 5148 } 5149 5150 // Correctly checking the serialization-related 5151 // methods is subtle. For the methods declared to be 5152 // private or directly declared in the class, the 5153 // enclosed elements of the class can be checked in 5154 // turn. However, writeReplace and readResolve can be 5155 // declared in a superclass and inherited. Note that 5156 // the runtime lookup walks the superclass chain 5157 // looking for writeReplace/readResolve via 5158 // Class.getDeclaredMethod. This differs from calling 5159 // Elements.getAllMembers(TypeElement) as the latter 5160 // will also pull in default methods from 5161 // superinterfaces. In other words, the runtime checks 5162 // (which long predate default methods on interfaces) 5163 // do not admit the possibility of inheriting methods 5164 // this way, a difference from general inheritance. 5165 5166 // The current implementation just checks the enclosed 5167 // elements and does not directly check the inherited 5168 // methods. If all the types are being checked this is 5169 // less of a concern; however, there are cases that 5170 // could be missed. In particular, readResolve and 5171 // writeReplace could, in principle, by inherited from 5172 // a non-serializable superclass and thus not checked 5173 // even if compiled with a serializable child class. 5174 case METHOD -> { 5175 var method = (MethodSymbol)enclosed; 5176 name = method.getSimpleName().toString(); 5177 if (serialMethodNames.contains(name)) { 5178 switch (name) { 5179 case "writeObject" -> checkWriteObject(tree, e, method); 5180 case "writeReplace" -> {hasWriteReplace[0] = true; hasAppropriateWriteReplace(tree, method, true);} 5181 case "readObject" -> checkReadObject(tree,e, method); 5182 case "readObjectNoData" -> checkReadObjectNoData(tree, e, method); 5183 case "readResolve" -> checkReadResolve(tree, e, method); 5184 default -> throw new AssertionError(); 5185 } 5186 } 5187 } 5188 } 5189 }); 5190 } 5191 if (!hasWriteReplace[0] && 5192 (c.isValueClass() || hasAbstractValueSuperClass(c, Set.of(syms.numberType.tsym))) && 5193 !c.isAbstract() && !c.isRecord() && 5194 types.unboxedType(c.type) == Type.noType) { 5195 // we need to check if the class is inheriting an appropriate writeReplace method 5196 MethodSymbol ms = null; 5197 Log.DiagnosticHandler discardHandler = new Log.DiscardDiagnosticHandler(log); 5198 try { 5199 ms = rs.resolveInternalMethod(env.tree, env, c.type, names.writeReplace, List.nil(), List.nil()); 5200 } catch (FatalError fe) { 5201 // ignore no method was found 5202 } finally { 5203 log.popDiagnosticHandler(discardHandler); 5204 } 5205 if (ms == null || !hasAppropriateWriteReplace(p, ms, false)) { 5206 log.warning(p.pos(), 5207 c.isValueClass() ? LintWarnings.SerializableValueClassWithoutWriteReplace1 : 5208 LintWarnings.SerializableValueClassWithoutWriteReplace2); 5209 } 5210 } 5211 return null; 5212 } 5213 5214 boolean canBeSerialized(Type type) { 5215 return type.isPrimitive() || rs.isSerializable(type); 5216 } 5217 5218 private boolean hasAbstractValueSuperClass(Symbol c, Set<Symbol> excluding) { 5219 while (c.getKind() == ElementKind.CLASS) { 5220 Type sup = ((ClassSymbol)c).getSuperclass(); 5221 if (!sup.hasTag(CLASS) || sup.isErroneous() || 5222 sup.tsym == syms.objectType.tsym) { 5223 return false; 5224 } 5225 // if it is a value super class it has to be abstract 5226 if (sup.isValueClass() && !excluding.contains(sup.tsym)) { 5227 return true; 5228 } 5229 c = sup.tsym; 5230 } 5231 return false; 5232 } 5233 5234 /** 5235 * Check that Externalizable class needs a public no-arg 5236 * constructor. 5237 * 5238 * Check that a Serializable class has access to the no-arg 5239 * constructor of its first nonserializable superclass. 5240 */ 5241 private void checkCtorAccess(JCClassDecl tree, ClassSymbol c) { 5242 if (isExternalizable(c.type)) { 5243 for(var sym : c.getEnclosedElements()) { 5244 if (sym.isConstructor() && 5245 ((sym.flags() & PUBLIC) == PUBLIC)) { 5246 if (((MethodSymbol)sym).getParameters().isEmpty()) { 5247 return; 5248 } 5249 } 5250 } 5251 log.warning(tree.pos(), 5252 LintWarnings.ExternalizableMissingPublicNoArgCtor); 5253 } else { 5254 // Approximate access to the no-arg constructor up in 5255 // the superclass chain by checking that the 5256 // constructor is not private. This may not handle 5257 // some cross-package situations correctly. 5258 Type superClass = c.getSuperclass(); 5259 // java.lang.Object is *not* Serializable so this loop 5260 // should terminate. 5261 while (rs.isSerializable(superClass) ) { 5262 try { 5263 superClass = (Type)((TypeElement)(((DeclaredType)superClass)).asElement()).getSuperclass(); 5264 } catch(ClassCastException cce) { 5265 return ; // Don't try to recover 5266 } 5267 } 5268 // Non-Serializable superclass 5269 try { 5270 ClassSymbol supertype = ((ClassSymbol)(((DeclaredType)superClass).asElement())); 5271 for(var sym : supertype.getEnclosedElements()) { 5272 if (sym.isConstructor()) { 5273 MethodSymbol ctor = (MethodSymbol)sym; 5274 if (ctor.getParameters().isEmpty()) { 5275 if (((ctor.flags() & PRIVATE) == PRIVATE) || 5276 // Handle nested classes and implicit this$0 5277 (supertype.getNestingKind() == NestingKind.MEMBER && 5278 ((supertype.flags() & STATIC) == 0))) 5279 log.warning(tree.pos(), 5280 LintWarnings.SerializableMissingAccessNoArgCtor(supertype.getQualifiedName())); 5281 } 5282 } 5283 } 5284 } catch (ClassCastException cce) { 5285 return ; // Don't try to recover 5286 } 5287 return; 5288 } 5289 } 5290 5291 private void checkSerialVersionUID(JCClassDecl tree, Element e, VarSymbol svuid) { 5292 // To be effective, serialVersionUID must be marked static 5293 // and final, but private is recommended. But alas, in 5294 // practice there are many non-private serialVersionUID 5295 // fields. 5296 if ((svuid.flags() & (STATIC | FINAL)) != 5297 (STATIC | FINAL)) { 5298 log.warning( 5299 TreeInfo.diagnosticPositionFor(svuid, tree), 5300 LintWarnings.ImproperSVUID((Symbol)e)); 5301 } 5302 5303 // check svuid has type long 5304 if (!svuid.type.hasTag(LONG)) { 5305 log.warning( 5306 TreeInfo.diagnosticPositionFor(svuid, tree), 5307 LintWarnings.LongSVUID((Symbol)e)); 5308 } 5309 5310 if (svuid.getConstValue() == null) 5311 log.warning( 5312 TreeInfo.diagnosticPositionFor(svuid, tree), 5313 LintWarnings.ConstantSVUID((Symbol)e)); 5314 } 5315 5316 private void checkSerialPersistentFields(JCClassDecl tree, Element e, VarSymbol spf) { 5317 // To be effective, serialPersisentFields must be private, static, and final. 5318 if ((spf.flags() & (PRIVATE | STATIC | FINAL)) != 5319 (PRIVATE | STATIC | FINAL)) { 5320 log.warning( 5321 TreeInfo.diagnosticPositionFor(spf, tree), 5322 LintWarnings.ImproperSPF); 5323 } 5324 5325 if (!types.isSameType(spf.type, OSF_TYPE)) { 5326 log.warning( 5327 TreeInfo.diagnosticPositionFor(spf, tree), 5328 LintWarnings.OSFArraySPF); 5329 } 5330 5331 if (isExternalizable((Type)(e.asType()))) { 5332 log.warning( 5333 TreeInfo.diagnosticPositionFor(spf, tree), 5334 LintWarnings.IneffectualSerialFieldExternalizable); 5335 } 5336 5337 // Warn if serialPersistentFields is initialized to a 5338 // literal null. 5339 JCTree spfDecl = TreeInfo.declarationFor(spf, tree); 5340 if (spfDecl != null && spfDecl.getTag() == VARDEF) { 5341 JCVariableDecl variableDef = (JCVariableDecl) spfDecl; 5342 JCExpression initExpr = variableDef.init; 5343 if (initExpr != null && TreeInfo.isNull(initExpr)) { 5344 log.warning(initExpr.pos(), 5345 LintWarnings.SPFNullInit); 5346 } 5347 } 5348 } 5349 5350 private void checkWriteObject(JCClassDecl tree, Element e, MethodSymbol method) { 5351 // The "synchronized" modifier is seen in the wild on 5352 // readObject and writeObject methods and is generally 5353 // innocuous. 5354 5355 // private void writeObject(ObjectOutputStream stream) throws IOException 5356 checkPrivateNonStaticMethod(tree, method); 5357 isExpectedReturnType(tree, method, syms.voidType, true); 5358 checkOneArg(tree, e, method, syms.objectOutputStreamType); 5359 hasExpectedExceptions(tree, method, true, syms.ioExceptionType); 5360 checkExternalizable(tree, e, method); 5361 } 5362 5363 private boolean hasAppropriateWriteReplace(JCClassDecl tree, MethodSymbol method, boolean warn) { 5364 // ANY-ACCESS-MODIFIER Object writeReplace() throws 5365 // ObjectStreamException 5366 5367 // Excluding abstract, could have a more complicated 5368 // rule based on abstract-ness of the class 5369 return isConcreteInstanceMethod(tree, method, warn) && 5370 isExpectedReturnType(tree, method, syms.objectType, warn) && 5371 hasNoArgs(tree, method, warn) && 5372 hasExpectedExceptions(tree, method, warn, syms.objectStreamExceptionType); 5373 } 5374 5375 private void checkReadObject(JCClassDecl tree, Element e, MethodSymbol method) { 5376 // The "synchronized" modifier is seen in the wild on 5377 // readObject and writeObject methods and is generally 5378 // innocuous. 5379 5380 // private void readObject(ObjectInputStream stream) 5381 // throws IOException, ClassNotFoundException 5382 checkPrivateNonStaticMethod(tree, method); 5383 isExpectedReturnType(tree, method, syms.voidType, true); 5384 checkOneArg(tree, e, method, syms.objectInputStreamType); 5385 hasExpectedExceptions(tree, method, true, syms.ioExceptionType, syms.classNotFoundExceptionType); 5386 checkExternalizable(tree, e, method); 5387 } 5388 5389 private void checkReadObjectNoData(JCClassDecl tree, Element e, MethodSymbol method) { 5390 // private void readObjectNoData() throws ObjectStreamException 5391 checkPrivateNonStaticMethod(tree, method); 5392 isExpectedReturnType(tree, method, syms.voidType, true); 5393 hasNoArgs(tree, method, true); 5394 hasExpectedExceptions(tree, method, true, syms.objectStreamExceptionType); 5395 checkExternalizable(tree, e, method); 5396 } 5397 5398 private void checkReadResolve(JCClassDecl tree, Element e, MethodSymbol method) { 5399 // ANY-ACCESS-MODIFIER Object readResolve() 5400 // throws ObjectStreamException 5401 5402 // Excluding abstract, could have a more complicated 5403 // rule based on abstract-ness of the class 5404 isConcreteInstanceMethod(tree, method, true); 5405 isExpectedReturnType(tree, method, syms.objectType, true); 5406 hasNoArgs(tree, method, true); 5407 hasExpectedExceptions(tree, method, true, syms.objectStreamExceptionType); 5408 } 5409 5410 private void checkWriteExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) { 5411 //public void writeExternal(ObjectOutput) throws IOException 5412 checkExternMethodRecord(tree, e, method, syms.objectOutputType, isExtern); 5413 } 5414 5415 private void checkReadExternalRecord(JCClassDecl tree, Element e, MethodSymbol method, boolean isExtern) { 5416 // public void readExternal(ObjectInput) throws IOException 5417 checkExternMethodRecord(tree, e, method, syms.objectInputType, isExtern); 5418 } 5419 5420 private void checkExternMethodRecord(JCClassDecl tree, Element e, MethodSymbol method, Type argType, 5421 boolean isExtern) { 5422 if (isExtern && isExternMethod(tree, e, method, argType)) { 5423 log.warning( 5424 TreeInfo.diagnosticPositionFor(method, tree), 5425 LintWarnings.IneffectualExternalizableMethodRecord(method.getSimpleName().toString())); 5426 } 5427 } 5428 5429 void checkPrivateNonStaticMethod(JCClassDecl tree, MethodSymbol method) { 5430 var flags = method.flags(); 5431 if ((flags & PRIVATE) == 0) { 5432 log.warning( 5433 TreeInfo.diagnosticPositionFor(method, tree), 5434 LintWarnings.SerialMethodNotPrivate(method.getSimpleName())); 5435 } 5436 5437 if ((flags & STATIC) != 0) { 5438 log.warning( 5439 TreeInfo.diagnosticPositionFor(method, tree), 5440 LintWarnings.SerialMethodStatic(method.getSimpleName())); 5441 } 5442 } 5443 5444 /** 5445 * Per section 1.12 "Serialization of Enum Constants" of 5446 * the serialization specification, due to the special 5447 * serialization handling of enums, any writeObject, 5448 * readObject, writeReplace, and readResolve methods are 5449 * ignored as are serialPersistentFields and 5450 * serialVersionUID fields. 5451 */ 5452 @Override 5453 public Void visitTypeAsEnum(TypeElement e, 5454 JCClassDecl p) { 5455 boolean isExtern = isExternalizable((Type)e.asType()); 5456 for(Element el : e.getEnclosedElements()) { 5457 runUnderLint(el, p, (enclosed, tree) -> { 5458 String name = enclosed.getSimpleName().toString(); 5459 switch(enclosed.getKind()) { 5460 case FIELD -> { 5461 var field = (VarSymbol)enclosed; 5462 if (serialFieldNames.contains(name)) { 5463 log.warning( 5464 TreeInfo.diagnosticPositionFor(field, tree), 5465 LintWarnings.IneffectualSerialFieldEnum(name)); 5466 } 5467 } 5468 5469 case METHOD -> { 5470 var method = (MethodSymbol)enclosed; 5471 if (serialMethodNames.contains(name)) { 5472 log.warning( 5473 TreeInfo.diagnosticPositionFor(method, tree), 5474 LintWarnings.IneffectualSerialMethodEnum(name)); 5475 } 5476 5477 if (isExtern) { 5478 switch(name) { 5479 case "writeExternal" -> checkWriteExternalEnum(tree, e, method); 5480 case "readExternal" -> checkReadExternalEnum(tree, e, method); 5481 } 5482 } 5483 } 5484 5485 // Also perform checks on any class bodies of enum constants, see JLS 8.9.1. 5486 case ENUM_CONSTANT -> { 5487 var field = (VarSymbol)enclosed; 5488 JCVariableDecl decl = (JCVariableDecl) TreeInfo.declarationFor(field, p); 5489 if (decl.init instanceof JCNewClass nc && nc.def != null) { 5490 ClassSymbol enumConstantType = nc.def.sym; 5491 visitTypeAsEnum(enumConstantType, p); 5492 } 5493 } 5494 5495 }}); 5496 } 5497 return null; 5498 } 5499 5500 private void checkWriteExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) { 5501 //public void writeExternal(ObjectOutput) throws IOException 5502 checkExternMethodEnum(tree, e, method, syms.objectOutputType); 5503 } 5504 5505 private void checkReadExternalEnum(JCClassDecl tree, Element e, MethodSymbol method) { 5506 // public void readExternal(ObjectInput) throws IOException 5507 checkExternMethodEnum(tree, e, method, syms.objectInputType); 5508 } 5509 5510 private void checkExternMethodEnum(JCClassDecl tree, Element e, MethodSymbol method, Type argType) { 5511 if (isExternMethod(tree, e, method, argType)) { 5512 log.warning( 5513 TreeInfo.diagnosticPositionFor(method, tree), 5514 LintWarnings.IneffectualExternMethodEnum(method.getSimpleName().toString())); 5515 } 5516 } 5517 5518 private boolean isExternMethod(JCClassDecl tree, Element e, MethodSymbol method, Type argType) { 5519 long flags = method.flags(); 5520 Type rtype = method.getReturnType(); 5521 5522 // Not necessary to check throws clause in this context 5523 return (flags & PUBLIC) != 0 && (flags & STATIC) == 0 && 5524 types.isSameType(syms.voidType, rtype) && 5525 hasExactlyOneArgWithType(tree, e, method, argType); 5526 } 5527 5528 /** 5529 * Most serialization-related fields and methods on interfaces 5530 * are ineffectual or problematic. 5531 */ 5532 @Override 5533 public Void visitTypeAsInterface(TypeElement e, 5534 JCClassDecl p) { 5535 for(Element el : e.getEnclosedElements()) { 5536 runUnderLint(el, p, (enclosed, tree) -> { 5537 String name = null; 5538 switch(enclosed.getKind()) { 5539 case FIELD -> { 5540 var field = (VarSymbol)enclosed; 5541 name = field.getSimpleName().toString(); 5542 switch(name) { 5543 case "serialPersistentFields" -> { 5544 log.warning( 5545 TreeInfo.diagnosticPositionFor(field, tree), 5546 LintWarnings.IneffectualSerialFieldInterface); 5547 } 5548 5549 case "serialVersionUID" -> { 5550 checkSerialVersionUID(tree, e, field); 5551 } 5552 } 5553 } 5554 5555 case METHOD -> { 5556 var method = (MethodSymbol)enclosed; 5557 name = enclosed.getSimpleName().toString(); 5558 if (serialMethodNames.contains(name)) { 5559 switch (name) { 5560 case 5561 "readObject", 5562 "readObjectNoData", 5563 "writeObject" -> checkPrivateMethod(tree, e, method); 5564 5565 case 5566 "writeReplace", 5567 "readResolve" -> checkDefaultIneffective(tree, e, method); 5568 5569 default -> throw new AssertionError(); 5570 } 5571 5572 } 5573 }} 5574 }); 5575 } 5576 5577 return null; 5578 } 5579 5580 private void checkPrivateMethod(JCClassDecl tree, 5581 Element e, 5582 MethodSymbol method) { 5583 if ((method.flags() & PRIVATE) == 0) { 5584 log.warning( 5585 TreeInfo.diagnosticPositionFor(method, tree), 5586 LintWarnings.NonPrivateMethodWeakerAccess); 5587 } 5588 } 5589 5590 private void checkDefaultIneffective(JCClassDecl tree, 5591 Element e, 5592 MethodSymbol method) { 5593 if ((method.flags() & DEFAULT) == DEFAULT) { 5594 log.warning( 5595 TreeInfo.diagnosticPositionFor(method, tree), 5596 LintWarnings.DefaultIneffective); 5597 5598 } 5599 } 5600 5601 @Override 5602 public Void visitTypeAsAnnotationType(TypeElement e, 5603 JCClassDecl p) { 5604 // Per the JLS, annotation types are not serializeable 5605 return null; 5606 } 5607 5608 /** 5609 * From the Java Object Serialization Specification, 1.13 5610 * Serialization of Records: 5611 * 5612 * "The process by which record objects are serialized or 5613 * externalized cannot be customized; any class-specific 5614 * writeObject, readObject, readObjectNoData, writeExternal, 5615 * and readExternal methods defined by record classes are 5616 * ignored during serialization and deserialization. However, 5617 * a substitute object to be serialized or a designate 5618 * replacement may be specified, by the writeReplace and 5619 * readResolve methods, respectively. Any 5620 * serialPersistentFields field declaration is 5621 * ignored. Documenting serializable fields and data for 5622 * record classes is unnecessary, since there is no variation 5623 * in the serial form, other than whether a substitute or 5624 * replacement object is used. The serialVersionUID of a 5625 * record class is 0L unless explicitly declared. The 5626 * requirement for matching serialVersionUID values is waived 5627 * for record classes." 5628 */ 5629 @Override 5630 public Void visitTypeAsRecord(TypeElement e, 5631 JCClassDecl p) { 5632 boolean isExtern = isExternalizable((Type)e.asType()); 5633 for(Element el : e.getEnclosedElements()) { 5634 runUnderLint(el, p, (enclosed, tree) -> { 5635 String name = enclosed.getSimpleName().toString(); 5636 switch(enclosed.getKind()) { 5637 case FIELD -> { 5638 var field = (VarSymbol)enclosed; 5639 switch(name) { 5640 case "serialPersistentFields" -> { 5641 log.warning( 5642 TreeInfo.diagnosticPositionFor(field, tree), 5643 LintWarnings.IneffectualSerialFieldRecord); 5644 } 5645 5646 case "serialVersionUID" -> { 5647 // Could generate additional warning that 5648 // svuid value is not checked to match for 5649 // records. 5650 checkSerialVersionUID(tree, e, field); 5651 }} 5652 } 5653 5654 case METHOD -> { 5655 var method = (MethodSymbol)enclosed; 5656 switch(name) { 5657 case "writeReplace" -> hasAppropriateWriteReplace(tree, method, true); 5658 case "readResolve" -> checkReadResolve(tree, e, method); 5659 5660 case "writeExternal" -> checkWriteExternalRecord(tree, e, method, isExtern); 5661 case "readExternal" -> checkReadExternalRecord(tree, e, method, isExtern); 5662 5663 default -> { 5664 if (serialMethodNames.contains(name)) { 5665 log.warning( 5666 TreeInfo.diagnosticPositionFor(method, tree), 5667 LintWarnings.IneffectualSerialMethodRecord(name)); 5668 } 5669 }} 5670 }}}); 5671 } 5672 return null; 5673 } 5674 5675 boolean isConcreteInstanceMethod(JCClassDecl tree, 5676 MethodSymbol method, 5677 boolean warn) { 5678 if ((method.flags() & (STATIC | ABSTRACT)) != 0) { 5679 if (warn) { 5680 log.warning( 5681 TreeInfo.diagnosticPositionFor(method, tree), 5682 LintWarnings.SerialConcreteInstanceMethod(method.getSimpleName())); 5683 } 5684 return false; 5685 } 5686 return true; 5687 } 5688 5689 private boolean isExpectedReturnType(JCClassDecl tree, 5690 MethodSymbol method, 5691 Type expectedReturnType, 5692 boolean warn) { 5693 // Note: there may be complications checking writeReplace 5694 // and readResolve since they return Object and could, in 5695 // principle, have covariant overrides and any synthetic 5696 // bridge method would not be represented here for 5697 // checking. 5698 Type rtype = method.getReturnType(); 5699 if (!types.isSameType(expectedReturnType, rtype)) { 5700 if (warn) { 5701 log.warning( 5702 TreeInfo.diagnosticPositionFor(method, tree), 5703 LintWarnings.SerialMethodUnexpectedReturnType(method.getSimpleName(), 5704 rtype, expectedReturnType)); 5705 } 5706 return false; 5707 } 5708 return true; 5709 } 5710 5711 private void checkOneArg(JCClassDecl tree, 5712 Element enclosing, 5713 MethodSymbol method, 5714 Type expectedType) { 5715 String name = method.getSimpleName().toString(); 5716 5717 var parameters= method.getParameters(); 5718 5719 if (parameters.size() != 1) { 5720 log.warning( 5721 TreeInfo.diagnosticPositionFor(method, tree), 5722 LintWarnings.SerialMethodOneArg(method.getSimpleName(), parameters.size())); 5723 return; 5724 } 5725 5726 Type parameterType = parameters.get(0).asType(); 5727 if (!types.isSameType(parameterType, expectedType)) { 5728 log.warning( 5729 TreeInfo.diagnosticPositionFor(method, tree), 5730 LintWarnings.SerialMethodParameterType(method.getSimpleName(), 5731 expectedType, 5732 parameterType)); 5733 } 5734 } 5735 5736 private boolean hasExactlyOneArgWithType(JCClassDecl tree, 5737 Element enclosing, 5738 MethodSymbol method, 5739 Type expectedType) { 5740 var parameters = method.getParameters(); 5741 return (parameters.size() == 1) && 5742 types.isSameType(parameters.get(0).asType(), expectedType); 5743 } 5744 5745 5746 boolean hasNoArgs(JCClassDecl tree, MethodSymbol method, boolean warn) { 5747 var parameters = method.getParameters(); 5748 if (!parameters.isEmpty()) { 5749 if (warn) { 5750 log.warning( 5751 TreeInfo.diagnosticPositionFor(parameters.get(0), tree), 5752 LintWarnings.SerialMethodNoArgs(method.getSimpleName())); 5753 } 5754 return false; 5755 } 5756 return true; 5757 } 5758 5759 private void checkExternalizable(JCClassDecl tree, Element enclosing, MethodSymbol method) { 5760 // If the enclosing class is externalizable, warn for the method 5761 if (isExternalizable((Type)enclosing.asType())) { 5762 log.warning( 5763 TreeInfo.diagnosticPositionFor(method, tree), 5764 LintWarnings.IneffectualSerialMethodExternalizable(method.getSimpleName())); 5765 } 5766 return; 5767 } 5768 5769 private boolean hasExpectedExceptions(JCClassDecl tree, 5770 MethodSymbol method, 5771 boolean warn, 5772 Type... declaredExceptions) { 5773 for (Type thrownType: method.getThrownTypes()) { 5774 // For each exception in the throws clause of the 5775 // method, if not an Error and not a RuntimeException, 5776 // check if the exception is a subtype of a declared 5777 // exception from the throws clause of the 5778 // serialization method in question. 5779 if (types.isSubtype(thrownType, syms.runtimeExceptionType) || 5780 types.isSubtype(thrownType, syms.errorType) ) { 5781 continue; 5782 } else { 5783 boolean declared = false; 5784 for (Type declaredException : declaredExceptions) { 5785 if (types.isSubtype(thrownType, declaredException)) { 5786 declared = true; 5787 continue; 5788 } 5789 } 5790 if (!declared) { 5791 if (warn) { 5792 log.warning( 5793 TreeInfo.diagnosticPositionFor(method, tree), 5794 LintWarnings.SerialMethodUnexpectedException(method.getSimpleName(), 5795 thrownType)); 5796 } 5797 return false; 5798 } 5799 } 5800 } 5801 return true; 5802 } 5803 5804 private <E extends Element> Void runUnderLint(E symbol, JCClassDecl p, BiConsumer<E, JCClassDecl> task) { 5805 Lint prevLint = lint; 5806 try { 5807 lint = lint.augment((Symbol) symbol); 5808 5809 if (lint.isEnabled(LintCategory.SERIAL)) { 5810 task.accept(symbol, p); 5811 } 5812 5813 return null; 5814 } finally { 5815 lint = prevLint; 5816 } 5817 } 5818 5819 } 5820 5821 }