1 /* 2 * Copyright (c) 2003, 2024, 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.code; 27 28 import java.lang.ref.SoftReference; 29 import java.util.HashSet; 30 import java.util.HashMap; 31 import java.util.Locale; 32 import java.util.Map; 33 import java.util.Optional; 34 import java.util.Set; 35 import java.util.WeakHashMap; 36 import java.util.function.BiPredicate; 37 import java.util.function.Function; 38 import java.util.function.Predicate; 39 import java.util.stream.Collector; 40 41 import javax.tools.JavaFileObject; 42 43 import com.sun.tools.javac.code.Attribute.RetentionPolicy; 44 import com.sun.tools.javac.code.Lint.LintCategory; 45 import com.sun.tools.javac.code.Source.Feature; 46 import com.sun.tools.javac.code.Type.UndetVar.InferenceBound; 47 import com.sun.tools.javac.code.TypeMetadata.Annotations; 48 import com.sun.tools.javac.comp.AttrContext; 49 import com.sun.tools.javac.comp.Check; 50 import com.sun.tools.javac.comp.Enter; 51 import com.sun.tools.javac.comp.Env; 52 import com.sun.tools.javac.comp.LambdaToMethod; 53 import com.sun.tools.javac.jvm.ClassFile; 54 import com.sun.tools.javac.util.*; 55 56 import static com.sun.tools.javac.code.BoundKind.*; 57 import static com.sun.tools.javac.code.Flags.*; 58 import static com.sun.tools.javac.code.Kinds.Kind.*; 59 import static com.sun.tools.javac.code.Scope.*; 60 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 61 import static com.sun.tools.javac.code.Symbol.*; 62 import static com.sun.tools.javac.code.Type.*; 63 import static com.sun.tools.javac.code.TypeTag.*; 64 import static com.sun.tools.javac.jvm.ClassFile.externalize; 65 import static com.sun.tools.javac.main.Option.DOE; 66 67 import com.sun.tools.javac.resources.CompilerProperties.Fragments; 68 69 /** 70 * Utility class containing various operations on types. 71 * 72 * <p>Unless other names are more illustrative, the following naming 73 * conventions should be observed in this file: 74 * 75 * <dl> 76 * <dt>t</dt> 77 * <dd>If the first argument to an operation is a type, it should be named t.</dd> 78 * <dt>s</dt> 79 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd> 80 * <dt>ts</dt> 81 * <dd>If an operations takes a list of types, the first should be named ts.</dd> 82 * <dt>ss</dt> 83 * <dd>A second list of types should be named ss.</dd> 84 * </dl> 85 * 86 * <p><b>This is NOT part of any supported API. 87 * If you write code that depends on this, you do so at your own risk. 88 * This code and its internal interfaces are subject to change or 89 * deletion without notice.</b> 90 */ 91 public class Types { 92 protected static final Context.Key<Types> typesKey = new Context.Key<>(); 93 94 final Symtab syms; 95 final JavacMessages messages; 96 final Names names; 97 final Check chk; 98 final Enter enter; 99 JCDiagnostic.Factory diags; 100 List<Warner> warnStack = List.nil(); 101 final Name capturedName; 102 103 public final Warner noWarnings; 104 public final boolean dumpStacktraceOnError; 105 106 // <editor-fold defaultstate="collapsed" desc="Instantiating"> 107 public static Types instance(Context context) { 108 Types instance = context.get(typesKey); 109 if (instance == null) 110 instance = new Types(context); 111 return instance; 112 } 113 114 @SuppressWarnings("this-escape") 115 protected Types(Context context) { 116 context.put(typesKey, this); 117 syms = Symtab.instance(context); 118 names = Names.instance(context); 119 Source source = Source.instance(context); 120 chk = Check.instance(context); 121 enter = Enter.instance(context); 122 capturedName = names.fromString("<captured wildcard>"); 123 messages = JavacMessages.instance(context); 124 diags = JCDiagnostic.Factory.instance(context); 125 noWarnings = new Warner(null); 126 Options options = Options.instance(context); 127 dumpStacktraceOnError = options.isSet("dev") || options.isSet(DOE); 128 } 129 // </editor-fold> 130 131 // <editor-fold defaultstate="collapsed" desc="bounds"> 132 /** 133 * Get a wildcard's upper bound, returning non-wildcards unchanged. 134 * @param t a type argument, either a wildcard or a type 135 */ 136 public Type wildUpperBound(Type t) { 137 if (t.hasTag(WILDCARD)) { 138 WildcardType w = (WildcardType) t; 139 if (w.isSuperBound()) 140 return w.bound == null ? syms.objectType : w.bound.getUpperBound(); 141 else 142 return wildUpperBound(w.type); 143 } 144 else return t; 145 } 146 147 /** 148 * Get a capture variable's upper bound, returning other types unchanged. 149 * @param t a type 150 */ 151 public Type cvarUpperBound(Type t) { 152 if (t.hasTag(TYPEVAR)) { 153 TypeVar v = (TypeVar) t; 154 return v.isCaptured() ? cvarUpperBound(v.getUpperBound()) : v; 155 } 156 else return t; 157 } 158 159 /** 160 * Get a wildcard's lower bound, returning non-wildcards unchanged. 161 * @param t a type argument, either a wildcard or a type 162 */ 163 public Type wildLowerBound(Type t) { 164 if (t.hasTag(WILDCARD)) { 165 WildcardType w = (WildcardType) t; 166 return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type); 167 } 168 else return t; 169 } 170 171 /** 172 * Get a capture variable's lower bound, returning other types unchanged. 173 * @param t a type 174 */ 175 public Type cvarLowerBound(Type t) { 176 if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) { 177 return cvarLowerBound(t.getLowerBound()); 178 } 179 else return t; 180 } 181 182 /** 183 * Recursively skip type-variables until a class/array type is found; capture conversion is then 184 * (optionally) applied to the resulting type. This is useful for i.e. computing a site that is 185 * suitable for a method lookup. 186 */ 187 public Type skipTypeVars(Type site, boolean capture) { 188 while (site.hasTag(TYPEVAR)) { 189 site = site.getUpperBound(); 190 } 191 return capture ? capture(site) : site; 192 } 193 // </editor-fold> 194 195 // <editor-fold defaultstate="collapsed" desc="projections"> 196 197 /** 198 * A projection kind. See {@link TypeProjection} 199 */ 200 enum ProjectionKind { 201 UPWARDS() { 202 @Override 203 ProjectionKind complement() { 204 return DOWNWARDS; 205 } 206 }, 207 DOWNWARDS() { 208 @Override 209 ProjectionKind complement() { 210 return UPWARDS; 211 } 212 }; 213 214 abstract ProjectionKind complement(); 215 } 216 217 /** 218 * This visitor performs upwards and downwards projections on types. 219 * 220 * A projection is defined as a function that takes a type T, a set of type variables V and that 221 * produces another type S. 222 * 223 * An upwards projection maps a type T into a type S such that (i) T has no variables in V, 224 * and (ii) S is an upper bound of T. 225 * 226 * A downwards projection maps a type T into a type S such that (i) T has no variables in V, 227 * and (ii) S is a lower bound of T. 228 * 229 * Note that projections are only allowed to touch variables in V. Therefore, it is possible for 230 * a projection to leave its input type unchanged if it does not contain any variables in V. 231 * 232 * Moreover, note that while an upwards projection is always defined (every type as an upper bound), 233 * a downwards projection is not always defined. 234 * 235 * Examples: 236 * 237 * {@code upwards(List<#CAP1>, [#CAP1]) = List<? extends String>, where #CAP1 <: String } 238 * {@code downwards(List<#CAP2>, [#CAP2]) = List<? super String>, where #CAP2 :> String } 239 * {@code upwards(List<#CAP1>, [#CAP2]) = List<#CAP1> } 240 * {@code downwards(List<#CAP1>, [#CAP1]) = not defined } 241 */ 242 class TypeProjection extends TypeMapping<ProjectionKind> { 243 244 List<Type> vars; 245 Set<Type> seen = new HashSet<>(); 246 247 public TypeProjection(List<Type> vars) { 248 this.vars = vars; 249 } 250 251 @Override 252 public Type visitClassType(ClassType t, ProjectionKind pkind) { 253 if (t.isCompound()) { 254 List<Type> components = directSupertypes(t); 255 List<Type> components1 = components.map(c -> c.map(this, pkind)); 256 if (components == components1) return t; 257 else return makeIntersectionType(components1); 258 } else { 259 Type outer = t.getEnclosingType(); 260 Type outer1 = visit(outer, pkind); 261 List<Type> typarams = t.getTypeArguments(); 262 List<Type> formals = t.tsym.type.getTypeArguments(); 263 ListBuffer<Type> typarams1 = new ListBuffer<>(); 264 boolean changed = false; 265 for (Type actual : typarams) { 266 Type t2 = mapTypeArgument(t, formals.head.getUpperBound(), actual, pkind); 267 if (t2.hasTag(BOT)) { 268 //not defined 269 return syms.botType; 270 } 271 typarams1.add(t2); 272 changed |= actual != t2; 273 formals = formals.tail; 274 } 275 if (outer1 == outer && !changed) return t; 276 else return new ClassType(outer1, typarams1.toList(), t.tsym, t.getMetadata()) { 277 @Override 278 protected boolean needsStripping() { 279 return true; 280 } 281 }; 282 } 283 } 284 285 @Override 286 public Type visitArrayType(ArrayType t, ProjectionKind s) { 287 Type elemtype = t.elemtype; 288 Type elemtype1 = visit(elemtype, s); 289 if (elemtype1 == elemtype) { 290 return t; 291 } else if (elemtype1.hasTag(BOT)) { 292 //undefined 293 return syms.botType; 294 } else { 295 return new ArrayType(elemtype1, t.tsym, t.metadata) { 296 @Override 297 protected boolean needsStripping() { 298 return true; 299 } 300 }; 301 } 302 } 303 304 @Override 305 public Type visitTypeVar(TypeVar t, ProjectionKind pkind) { 306 if (vars.contains(t)) { 307 if (seen.add(t)) { 308 try { 309 final Type bound; 310 switch (pkind) { 311 case UPWARDS: 312 bound = t.getUpperBound(); 313 break; 314 case DOWNWARDS: 315 bound = (t.getLowerBound() == null) ? 316 syms.botType : 317 t.getLowerBound(); 318 break; 319 default: 320 Assert.error(); 321 return null; 322 } 323 return bound.map(this, pkind); 324 } finally { 325 seen.remove(t); 326 } 327 } else { 328 //cycle 329 return pkind == ProjectionKind.UPWARDS ? 330 syms.objectType : syms.botType; 331 } 332 } else { 333 return t; 334 } 335 } 336 337 private Type mapTypeArgument(Type site, Type declaredBound, Type t, ProjectionKind pkind) { 338 return t.containsAny(vars) ? 339 t.map(new TypeArgumentProjection(site, declaredBound), pkind) : 340 t; 341 } 342 343 class TypeArgumentProjection extends TypeMapping<ProjectionKind> { 344 345 Type site; 346 Type declaredBound; 347 348 TypeArgumentProjection(Type site, Type declaredBound) { 349 this.site = site; 350 this.declaredBound = declaredBound; 351 } 352 353 @Override 354 public Type visitType(Type t, ProjectionKind pkind) { 355 //type argument is some type containing restricted vars 356 if (pkind == ProjectionKind.DOWNWARDS) { 357 //not defined 358 return syms.botType; 359 } 360 Type upper = t.map(TypeProjection.this, ProjectionKind.UPWARDS); 361 Type lower = t.map(TypeProjection.this, ProjectionKind.DOWNWARDS); 362 List<Type> formals = site.tsym.type.getTypeArguments(); 363 BoundKind bk; 364 Type bound; 365 if (!isSameType(upper, syms.objectType) && 366 (declaredBound.containsAny(formals) || 367 !isSubtype(declaredBound, upper))) { 368 bound = upper; 369 bk = EXTENDS; 370 } else if (!lower.hasTag(BOT)) { 371 bound = lower; 372 bk = SUPER; 373 } else { 374 bound = syms.objectType; 375 bk = UNBOUND; 376 } 377 return makeWildcard(bound, bk); 378 } 379 380 @Override 381 public Type visitWildcardType(WildcardType wt, ProjectionKind pkind) { 382 //type argument is some wildcard whose bound contains restricted vars 383 Type bound = syms.botType; 384 BoundKind bk = wt.kind; 385 switch (wt.kind) { 386 case EXTENDS: 387 bound = wt.type.map(TypeProjection.this, pkind); 388 if (bound.hasTag(BOT)) { 389 return syms.botType; 390 } 391 break; 392 case SUPER: 393 bound = wt.type.map(TypeProjection.this, pkind.complement()); 394 if (bound.hasTag(BOT)) { 395 bound = syms.objectType; 396 bk = UNBOUND; 397 } 398 break; 399 } 400 return makeWildcard(bound, bk); 401 } 402 403 private Type makeWildcard(Type bound, BoundKind bk) { 404 return new WildcardType(bound, bk, syms.boundClass) { 405 @Override 406 protected boolean needsStripping() { 407 return true; 408 } 409 }; 410 } 411 } 412 } 413 414 /** 415 * Computes an upward projection of given type, and vars. See {@link TypeProjection}. 416 * 417 * @param t the type to be projected 418 * @param vars the set of type variables to be mapped 419 * @return the type obtained as result of the projection 420 */ 421 public Type upward(Type t, List<Type> vars) { 422 return t.map(new TypeProjection(vars), ProjectionKind.UPWARDS); 423 } 424 425 /** 426 * Computes the set of captured variables mentioned in a given type. See {@link CaptureScanner}. 427 * This routine is typically used to computed the input set of variables to be used during 428 * an upwards projection (see {@link Types#upward(Type, List)}). 429 * 430 * @param t the type where occurrences of captured variables have to be found 431 * @return the set of captured variables found in t 432 */ 433 public List<Type> captures(Type t) { 434 CaptureScanner cs = new CaptureScanner(); 435 Set<Type> captures = new HashSet<>(); 436 cs.visit(t, captures); 437 return List.from(captures); 438 } 439 440 /** 441 * This visitor scans a type recursively looking for occurrences of captured type variables. 442 */ 443 class CaptureScanner extends SimpleVisitor<Void, Set<Type>> { 444 445 @Override 446 public Void visitType(Type t, Set<Type> types) { 447 return null; 448 } 449 450 @Override 451 public Void visitClassType(ClassType t, Set<Type> seen) { 452 if (t.isCompound()) { 453 directSupertypes(t).forEach(s -> visit(s, seen)); 454 } else { 455 t.allparams().forEach(ta -> visit(ta, seen)); 456 } 457 return null; 458 } 459 460 @Override 461 public Void visitArrayType(ArrayType t, Set<Type> seen) { 462 return visit(t.elemtype, seen); 463 } 464 465 @Override 466 public Void visitWildcardType(WildcardType t, Set<Type> seen) { 467 visit(t.type, seen); 468 return null; 469 } 470 471 @Override 472 public Void visitTypeVar(TypeVar t, Set<Type> seen) { 473 if ((t.tsym.flags() & Flags.SYNTHETIC) != 0 && seen.add(t)) { 474 visit(t.getUpperBound(), seen); 475 } 476 return null; 477 } 478 479 @Override 480 public Void visitCapturedType(CapturedType t, Set<Type> seen) { 481 if (seen.add(t)) { 482 visit(t.getUpperBound(), seen); 483 visit(t.getLowerBound(), seen); 484 } 485 return null; 486 } 487 } 488 489 // </editor-fold> 490 491 // <editor-fold defaultstate="collapsed" desc="isUnbounded"> 492 /** 493 * Checks that all the arguments to a class are unbounded 494 * wildcards or something else that doesn't make any restrictions 495 * on the arguments. If a class isUnbounded, a raw super- or 496 * subclass can be cast to it without a warning. 497 * @param t a type 498 * @return true iff the given type is unbounded or raw 499 */ 500 public boolean isUnbounded(Type t) { 501 return isUnbounded.visit(t); 502 } 503 // where 504 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() { 505 506 public Boolean visitType(Type t, Void ignored) { 507 return true; 508 } 509 510 @Override 511 public Boolean visitClassType(ClassType t, Void ignored) { 512 List<Type> parms = t.tsym.type.allparams(); 513 List<Type> args = t.allparams(); 514 while (parms.nonEmpty()) { 515 WildcardType unb = new WildcardType(syms.objectType, 516 BoundKind.UNBOUND, 517 syms.boundClass, 518 (TypeVar)parms.head); 519 if (!containsType(args.head, unb)) 520 return false; 521 parms = parms.tail; 522 args = args.tail; 523 } 524 return true; 525 } 526 }; 527 // </editor-fold> 528 529 // <editor-fold defaultstate="collapsed" desc="asSub"> 530 /** 531 * Return the least specific subtype of t that starts with symbol 532 * sym. If none exists, return null. The least specific subtype 533 * is determined as follows: 534 * 535 * <p>If there is exactly one parameterized instance of sym that is a 536 * subtype of t, that parameterized instance is returned.<br> 537 * Otherwise, if the plain type or raw type `sym' is a subtype of 538 * type t, the type `sym' itself is returned. Otherwise, null is 539 * returned. 540 */ 541 public Type asSub(Type t, Symbol sym) { 542 return asSub.visit(t, sym); 543 } 544 // where 545 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() { 546 547 public Type visitType(Type t, Symbol sym) { 548 return null; 549 } 550 551 @Override 552 public Type visitClassType(ClassType t, Symbol sym) { 553 if (t.tsym == sym) 554 return t; 555 Type base = asSuper(sym.type, t.tsym); 556 if (base == null) 557 return null; 558 ListBuffer<Type> from = new ListBuffer<>(); 559 ListBuffer<Type> to = new ListBuffer<>(); 560 try { 561 adapt(base, t, from, to); 562 } catch (AdaptFailure ex) { 563 return null; 564 } 565 Type res = subst(sym.type, from.toList(), to.toList()); 566 if (!isSubtype(res, t)) 567 return null; 568 ListBuffer<Type> openVars = new ListBuffer<>(); 569 for (List<Type> l = sym.type.allparams(); 570 l.nonEmpty(); l = l.tail) 571 if (res.contains(l.head) && !t.contains(l.head)) 572 openVars.append(l.head); 573 if (openVars.nonEmpty()) { 574 if (t.isRaw()) { 575 // The subtype of a raw type is raw 576 res = erasure(res); 577 } else { 578 // Unbound type arguments default to ? 579 List<Type> opens = openVars.toList(); 580 ListBuffer<Type> qs = new ListBuffer<>(); 581 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) { 582 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, 583 syms.boundClass, (TypeVar) iter.head)); 584 } 585 res = subst(res, opens, qs.toList()); 586 } 587 } 588 return res; 589 } 590 591 @Override 592 public Type visitErrorType(ErrorType t, Symbol sym) { 593 return t; 594 } 595 }; 596 // </editor-fold> 597 598 // <editor-fold defaultstate="collapsed" desc="isConvertible"> 599 /** 600 * Is t a subtype of or convertible via boxing/unboxing 601 * conversion to s? 602 */ 603 public boolean isConvertible(Type t, Type s, Warner warn) { 604 if (t.hasTag(ERROR)) { 605 return true; 606 } 607 boolean tPrimitive = t.isPrimitive(); 608 boolean sPrimitive = s.isPrimitive(); 609 if (tPrimitive == sPrimitive) { 610 return isSubtypeUnchecked(t, s, warn); 611 } 612 boolean tUndet = t.hasTag(UNDETVAR); 613 boolean sUndet = s.hasTag(UNDETVAR); 614 615 if (tUndet || sUndet) { 616 return tUndet ? 617 isSubtype(t, boxedTypeOrType(s)) : 618 isSubtype(boxedTypeOrType(t), s); 619 } 620 621 return tPrimitive 622 ? isSubtype(boxedClass(t).type, s) 623 : isSubtype(unboxedType(t), s); 624 } 625 626 /** 627 * Is t a subtype of or convertible via boxing/unboxing 628 * conversions to s? 629 */ 630 public boolean isConvertible(Type t, Type s) { 631 return isConvertible(t, s, noWarnings); 632 } 633 // </editor-fold> 634 635 // <editor-fold defaultstate="collapsed" desc="findSam"> 636 637 /** 638 * Exception used to report a function descriptor lookup failure. The exception 639 * wraps a diagnostic that can be used to generate more details error 640 * messages. 641 */ 642 public static class FunctionDescriptorLookupError extends CompilerInternalException { 643 private static final long serialVersionUID = 0; 644 645 transient JCDiagnostic diagnostic; 646 647 FunctionDescriptorLookupError(boolean dumpStackTraceOnError) { 648 super(dumpStackTraceOnError); 649 this.diagnostic = null; 650 } 651 652 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) { 653 this.diagnostic = diag; 654 return this; 655 } 656 657 public JCDiagnostic getDiagnostic() { 658 return diagnostic; 659 } 660 } 661 662 /** 663 * A cache that keeps track of function descriptors associated with given 664 * functional interfaces. 665 */ 666 class DescriptorCache { 667 668 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>(); 669 670 class FunctionDescriptor { 671 Symbol descSym; 672 673 FunctionDescriptor(Symbol descSym) { 674 this.descSym = descSym; 675 } 676 677 public Symbol getSymbol() { 678 return descSym; 679 } 680 681 public Type getType(Type site) { 682 site = removeWildcards(site); 683 if (site.isIntersection()) { 684 IntersectionClassType ict = (IntersectionClassType)site; 685 for (Type component : ict.getExplicitComponents()) { 686 if (!chk.checkValidGenericType(component)) { 687 //if the inferred functional interface type is not well-formed, 688 //or if it's not a subtype of the original target, issue an error 689 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site))); 690 } 691 } 692 } else { 693 if (!chk.checkValidGenericType(site)) { 694 //if the inferred functional interface type is not well-formed, 695 //or if it's not a subtype of the original target, issue an error 696 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site))); 697 } 698 } 699 return memberType(site, descSym); 700 } 701 } 702 703 class Entry { 704 final FunctionDescriptor cachedDescRes; 705 final int prevMark; 706 707 public Entry(FunctionDescriptor cachedDescRes, 708 int prevMark) { 709 this.cachedDescRes = cachedDescRes; 710 this.prevMark = prevMark; 711 } 712 713 boolean matches(int mark) { 714 return this.prevMark == mark; 715 } 716 } 717 718 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError { 719 Entry e = _map.get(origin); 720 CompoundScope members = membersClosure(origin.type, false); 721 if (e == null || 722 !e.matches(members.getMark())) { 723 FunctionDescriptor descRes = findDescriptorInternal(origin, members); 724 _map.put(origin, new Entry(descRes, members.getMark())); 725 return descRes; 726 } 727 else { 728 return e.cachedDescRes; 729 } 730 } 731 732 /** 733 * Compute the function descriptor associated with a given functional interface 734 */ 735 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin, 736 CompoundScope membersCache) throws FunctionDescriptorLookupError { 737 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0 || origin.isSealed()) { 738 //t must be an interface 739 throw failure("not.a.functional.intf", origin); 740 } 741 742 final ListBuffer<Symbol> abstracts = new ListBuffer<>(); 743 for (Symbol sym : membersCache.getSymbols(new DescriptorFilter(origin))) { 744 Type mtype = memberType(origin.type, sym); 745 if (abstracts.isEmpty()) { 746 abstracts.append(sym); 747 } else if ((sym.name == abstracts.first().name && 748 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) { 749 if (!abstracts.stream().filter(msym -> msym.owner.isSubClass(sym.enclClass(), Types.this)) 750 .map(msym -> memberType(origin.type, msym)) 751 .anyMatch(abstractMType -> isSubSignature(abstractMType, mtype))) { 752 abstracts.append(sym); 753 } 754 } else { 755 //the target method(s) should be the only abstract members of t 756 throw failure("not.a.functional.intf.1", origin, 757 diags.fragment(Fragments.IncompatibleAbstracts(Kinds.kindName(origin), origin))); 758 } 759 } 760 if (abstracts.isEmpty()) { 761 //t must define a suitable non-generic method 762 throw failure("not.a.functional.intf.1", origin, 763 diags.fragment(Fragments.NoAbstracts(Kinds.kindName(origin), origin))); 764 } else if (abstracts.size() == 1) { 765 return new FunctionDescriptor(abstracts.first()); 766 } else { // size > 1 767 FunctionDescriptor descRes = mergeDescriptors(origin, abstracts.toList()); 768 if (descRes == null) { 769 //we can get here if the functional interface is ill-formed 770 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>(); 771 for (Symbol desc : abstracts) { 772 String key = desc.type.getThrownTypes().nonEmpty() ? 773 "descriptor.throws" : "descriptor"; 774 descriptors.append(diags.fragment(key, desc.name, 775 desc.type.getParameterTypes(), 776 desc.type.getReturnType(), 777 desc.type.getThrownTypes())); 778 } 779 JCDiagnostic msg = 780 diags.fragment(Fragments.IncompatibleDescsInFunctionalIntf(Kinds.kindName(origin), 781 origin)); 782 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors = 783 new JCDiagnostic.MultilineDiagnostic(msg, descriptors.toList()); 784 throw failure(incompatibleDescriptors); 785 } 786 return descRes; 787 } 788 } 789 790 /** 791 * Compute a synthetic type for the target descriptor given a list 792 * of override-equivalent methods in the functional interface type. 793 * The resulting method type is a method type that is override-equivalent 794 * and return-type substitutable with each method in the original list. 795 */ 796 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) { 797 return mergeAbstracts(methodSyms, origin.type, false) 798 .map(bestSoFar -> new FunctionDescriptor(bestSoFar.baseSymbol()) { 799 @Override 800 public Type getType(Type origin) { 801 Type mt = memberType(origin, getSymbol()); 802 return createMethodTypeWithThrown(mt, bestSoFar.type.getThrownTypes()); 803 } 804 }).orElse(null); 805 } 806 807 FunctionDescriptorLookupError failure(String msg, Object... args) { 808 return failure(diags.fragment(msg, args)); 809 } 810 811 FunctionDescriptorLookupError failure(JCDiagnostic diag) { 812 return new FunctionDescriptorLookupError(Types.this.dumpStacktraceOnError).setMessage(diag); 813 } 814 } 815 816 private DescriptorCache descCache = new DescriptorCache(); 817 818 /** 819 * Find the method descriptor associated to this class symbol - if the 820 * symbol 'origin' is not a functional interface, an exception is thrown. 821 */ 822 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError { 823 return descCache.get(origin).getSymbol(); 824 } 825 826 /** 827 * Find the type of the method descriptor associated to this class symbol - 828 * if the symbol 'origin' is not a functional interface, an exception is thrown. 829 */ 830 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError { 831 return descCache.get(origin.tsym).getType(origin); 832 } 833 834 /** 835 * Is given type a functional interface? 836 */ 837 public boolean isFunctionalInterface(TypeSymbol tsym) { 838 try { 839 findDescriptorSymbol(tsym); 840 return true; 841 } catch (FunctionDescriptorLookupError ex) { 842 return false; 843 } 844 } 845 846 public boolean isFunctionalInterface(Type site) { 847 try { 848 findDescriptorType(site); 849 return true; 850 } catch (FunctionDescriptorLookupError ex) { 851 return false; 852 } 853 } 854 855 public Type removeWildcards(Type site) { 856 if (site.getTypeArguments().stream().anyMatch(t -> t.hasTag(WILDCARD))) { 857 //compute non-wildcard parameterization - JLS 9.9 858 List<Type> actuals = site.getTypeArguments(); 859 List<Type> formals = site.tsym.type.getTypeArguments(); 860 ListBuffer<Type> targs = new ListBuffer<>(); 861 for (Type formal : formals) { 862 Type actual = actuals.head; 863 Type bound = formal.getUpperBound(); 864 if (actuals.head.hasTag(WILDCARD)) { 865 WildcardType wt = (WildcardType)actual; 866 //check that bound does not contain other formals 867 if (bound.containsAny(formals)) { 868 targs.add(wt.type); 869 } else { 870 //compute new type-argument based on declared bound and wildcard bound 871 switch (wt.kind) { 872 case UNBOUND: 873 targs.add(bound); 874 break; 875 case EXTENDS: 876 targs.add(glb(bound, wt.type)); 877 break; 878 case SUPER: 879 targs.add(wt.type); 880 break; 881 default: 882 Assert.error("Cannot get here!"); 883 } 884 } 885 } else { 886 //not a wildcard - the new type argument remains unchanged 887 targs.add(actual); 888 } 889 actuals = actuals.tail; 890 } 891 return subst(site.tsym.type, formals, targs.toList()); 892 } else { 893 return site; 894 } 895 } 896 897 /** 898 * Create a symbol for a class that implements a given functional interface 899 * and overrides its functional descriptor. This routine is used for two 900 * main purposes: (i) checking well-formedness of a functional interface; 901 * (ii) perform functional interface bridge calculation. 902 */ 903 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, Type target, long cflags) { 904 if (target == null || target == syms.unknownType) { 905 return null; 906 } 907 Symbol descSym = findDescriptorSymbol(target.tsym); 908 Type descType = findDescriptorType(target); 909 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass()); 910 csym.completer = Completer.NULL_COMPLETER; 911 csym.members_field = WriteableScope.create(csym); 912 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym); 913 csym.members_field.enter(instDescSym); 914 Type.ClassType ctype = new Type.ClassType(Type.noType, List.nil(), csym); 915 ctype.supertype_field = syms.objectType; 916 ctype.interfaces_field = target.isIntersection() ? 917 directSupertypes(target) : 918 List.of(target); 919 csym.type = ctype; 920 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile; 921 return csym; 922 } 923 924 /** 925 * Find the minimal set of methods that are overridden by the functional 926 * descriptor in 'origin'. All returned methods are assumed to have different 927 * erased signatures. 928 */ 929 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) { 930 Assert.check(isFunctionalInterface(origin)); 931 Symbol descSym = findDescriptorSymbol(origin); 932 CompoundScope members = membersClosure(origin.type, false); 933 ListBuffer<Symbol> overridden = new ListBuffer<>(); 934 outer: for (Symbol m2 : members.getSymbolsByName(descSym.name, bridgeFilter)) { 935 if (m2 == descSym) continue; 936 else if (descSym.overrides(m2, origin, Types.this, false)) { 937 for (Symbol m3 : overridden) { 938 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) || 939 (m3.overrides(m2, origin, Types.this, false) && 940 (pendingBridges((ClassSymbol)origin, m3.enclClass()) || 941 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) { 942 continue outer; 943 } 944 } 945 overridden.add(m2); 946 } 947 } 948 return overridden.toList(); 949 } 950 //where 951 // Use anonymous class instead of lambda expression intentionally, 952 // because the variable `names` has modifier: final. 953 private Predicate<Symbol> bridgeFilter = new Predicate<Symbol>() { 954 public boolean test(Symbol t) { 955 return t.kind == MTH && 956 t.name != names.init && 957 t.name != names.clinit && 958 (t.flags() & SYNTHETIC) == 0; 959 } 960 }; 961 962 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) { 963 //a symbol will be completed from a classfile if (a) symbol has 964 //an associated file object with CLASS kind and (b) the symbol has 965 //not been entered 966 if (origin.classfile != null && 967 origin.classfile.getKind() == JavaFileObject.Kind.CLASS && 968 enter.getEnv(origin) == null) { 969 return false; 970 } 971 if (origin == s) { 972 return true; 973 } 974 for (Type t : interfaces(origin.type)) { 975 if (pendingBridges((ClassSymbol)t.tsym, s)) { 976 return true; 977 } 978 } 979 return false; 980 } 981 // </editor-fold> 982 983 /** 984 * Scope filter used to skip methods that should be ignored (such as methods 985 * overridden by j.l.Object) during function interface conversion interface check 986 */ 987 class DescriptorFilter implements Predicate<Symbol> { 988 989 TypeSymbol origin; 990 991 DescriptorFilter(TypeSymbol origin) { 992 this.origin = origin; 993 } 994 995 @Override 996 public boolean test(Symbol sym) { 997 return sym.kind == MTH && 998 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT && 999 !overridesObjectMethod(origin, sym) && 1000 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0; 1001 } 1002 } 1003 1004 // <editor-fold defaultstate="collapsed" desc="isSubtype"> 1005 /** 1006 * Is t an unchecked subtype of s? 1007 */ 1008 public boolean isSubtypeUnchecked(Type t, Type s) { 1009 return isSubtypeUnchecked(t, s, noWarnings); 1010 } 1011 /** 1012 * Is t an unchecked subtype of s? 1013 */ 1014 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) { 1015 boolean result = isSubtypeUncheckedInternal(t, s, true, warn); 1016 if (result) { 1017 checkUnsafeVarargsConversion(t, s, warn); 1018 } 1019 return result; 1020 } 1021 //where 1022 private boolean isSubtypeUncheckedInternal(Type t, Type s, boolean capture, Warner warn) { 1023 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) { 1024 if (((ArrayType)t).elemtype.isPrimitive()) { 1025 return isSameType(elemtype(t), elemtype(s)); 1026 } else { 1027 return isSubtypeUncheckedInternal(elemtype(t), elemtype(s), false, warn); 1028 } 1029 } else if (isSubtype(t, s, capture)) { 1030 return true; 1031 } else if (t.hasTag(TYPEVAR)) { 1032 return isSubtypeUncheckedInternal(t.getUpperBound(), s, false, warn); 1033 } else if (!s.isRaw()) { 1034 Type t2 = asSuper(t, s.tsym); 1035 if (t2 != null && t2.isRaw()) { 1036 if (isReifiable(s)) { 1037 warn.silentWarn(LintCategory.UNCHECKED); 1038 } else { 1039 warn.warn(LintCategory.UNCHECKED); 1040 } 1041 return true; 1042 } 1043 } 1044 return false; 1045 } 1046 1047 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) { 1048 if (!t.hasTag(ARRAY) || isReifiable(t)) { 1049 return; 1050 } 1051 ArrayType from = (ArrayType)t; 1052 boolean shouldWarn = false; 1053 switch (s.getTag()) { 1054 case ARRAY: 1055 ArrayType to = (ArrayType)s; 1056 shouldWarn = from.isVarargs() && 1057 !to.isVarargs() && 1058 !isReifiable(from); 1059 break; 1060 case CLASS: 1061 shouldWarn = from.isVarargs(); 1062 break; 1063 } 1064 if (shouldWarn) { 1065 warn.warn(LintCategory.VARARGS); 1066 } 1067 } 1068 1069 /** 1070 * Is t a subtype of s?<br> 1071 * (not defined for Method and ForAll types) 1072 */ 1073 public final boolean isSubtype(Type t, Type s) { 1074 return isSubtype(t, s, true); 1075 } 1076 public final boolean isSubtypeNoCapture(Type t, Type s) { 1077 return isSubtype(t, s, false); 1078 } 1079 public boolean isSubtype(Type t, Type s, boolean capture) { 1080 if (t.equalsIgnoreMetadata(s)) 1081 return true; 1082 if (s.isPartial()) 1083 return isSuperType(s, t); 1084 1085 if (s.isCompound()) { 1086 for (Type s2 : interfaces(s).prepend(supertype(s))) { 1087 if (!isSubtype(t, s2, capture)) 1088 return false; 1089 } 1090 return true; 1091 } 1092 1093 // Generally, if 's' is a lower-bounded type variable, recur on lower bound; but 1094 // for inference variables and intersections, we need to keep 's' 1095 // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars) 1096 if (!t.hasTag(UNDETVAR) && !t.isCompound()) { 1097 // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s 1098 Type lower = cvarLowerBound(wildLowerBound(s)); 1099 if (s != lower && !lower.hasTag(BOT)) 1100 return isSubtype(capture ? capture(t) : t, lower, false); 1101 } 1102 1103 return isSubtype.visit(capture ? capture(t) : t, s); 1104 } 1105 // where 1106 private TypeRelation isSubtype = new TypeRelation() 1107 { 1108 @Override 1109 public Boolean visitType(Type t, Type s) { 1110 switch (t.getTag()) { 1111 case BYTE: 1112 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag())); 1113 case CHAR: 1114 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag())); 1115 case SHORT: case INT: case LONG: 1116 case FLOAT: case DOUBLE: 1117 return t.getTag().isSubRangeOf(s.getTag()); 1118 case BOOLEAN: case VOID: 1119 return t.hasTag(s.getTag()); 1120 case TYPEVAR: 1121 return isSubtypeNoCapture(t.getUpperBound(), s); 1122 case BOT: 1123 return 1124 s.hasTag(BOT) || s.hasTag(CLASS) || 1125 s.hasTag(ARRAY) || s.hasTag(TYPEVAR); 1126 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495) 1127 case NONE: 1128 return false; 1129 default: 1130 throw new AssertionError("isSubtype " + t.getTag()); 1131 } 1132 } 1133 1134 private Set<TypePair> cache = new HashSet<>(); 1135 1136 private boolean containsTypeRecursive(Type t, Type s) { 1137 TypePair pair = new TypePair(t, s); 1138 if (cache.add(pair)) { 1139 try { 1140 return containsType(t.getTypeArguments(), 1141 s.getTypeArguments()); 1142 } finally { 1143 cache.remove(pair); 1144 } 1145 } else { 1146 return containsType(t.getTypeArguments(), 1147 rewriteSupers(s).getTypeArguments()); 1148 } 1149 } 1150 1151 private Type rewriteSupers(Type t) { 1152 if (!t.isParameterized()) 1153 return t; 1154 ListBuffer<Type> from = new ListBuffer<>(); 1155 ListBuffer<Type> to = new ListBuffer<>(); 1156 adaptSelf(t, from, to); 1157 if (from.isEmpty()) 1158 return t; 1159 ListBuffer<Type> rewrite = new ListBuffer<>(); 1160 boolean changed = false; 1161 for (Type orig : to.toList()) { 1162 Type s = rewriteSupers(orig); 1163 if (s.isSuperBound() && !s.isExtendsBound()) { 1164 s = new WildcardType(syms.objectType, 1165 BoundKind.UNBOUND, 1166 syms.boundClass, 1167 s.getMetadata()); 1168 changed = true; 1169 } else if (s != orig) { 1170 s = new WildcardType(wildUpperBound(s), 1171 BoundKind.EXTENDS, 1172 syms.boundClass, 1173 s.getMetadata()); 1174 changed = true; 1175 } 1176 rewrite.append(s); 1177 } 1178 if (changed) 1179 return subst(t.tsym.type, from.toList(), rewrite.toList()); 1180 else 1181 return t; 1182 } 1183 1184 @Override 1185 public Boolean visitClassType(ClassType t, Type s) { 1186 Type sup = asSuper(t, s.tsym); 1187 if (sup == null) return false; 1188 // If t is an intersection, sup might not be a class type 1189 if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s); 1190 return sup.tsym == s.tsym 1191 // Check type variable containment 1192 && (!s.isParameterized() || containsTypeRecursive(s, sup)) 1193 && isSubtypeNoCapture(sup.getEnclosingType(), 1194 s.getEnclosingType()); 1195 } 1196 1197 @Override 1198 public Boolean visitArrayType(ArrayType t, Type s) { 1199 if (s.hasTag(ARRAY)) { 1200 if (t.elemtype.isPrimitive()) 1201 return isSameType(t.elemtype, elemtype(s)); 1202 else 1203 return isSubtypeNoCapture(t.elemtype, elemtype(s)); 1204 } 1205 1206 if (s.hasTag(CLASS)) { 1207 Name sname = s.tsym.getQualifiedName(); 1208 return sname == names.java_lang_Object 1209 || sname == names.java_lang_Cloneable 1210 || sname == names.java_io_Serializable; 1211 } 1212 1213 return false; 1214 } 1215 1216 @Override 1217 public Boolean visitUndetVar(UndetVar t, Type s) { 1218 //todo: test against origin needed? or replace with substitution? 1219 if (t == s || t.qtype == s || s.hasTag(ERROR)) { 1220 return true; 1221 } else if (s.hasTag(BOT)) { 1222 //if 's' is 'null' there's no instantiated type U for which 1223 //U <: s (but 'null' itself, which is not a valid type) 1224 return false; 1225 } 1226 1227 t.addBound(InferenceBound.UPPER, s, Types.this); 1228 return true; 1229 } 1230 1231 @Override 1232 public Boolean visitErrorType(ErrorType t, Type s) { 1233 return true; 1234 } 1235 }; 1236 1237 /** 1238 * Is t a subtype of every type in given list `ts'?<br> 1239 * (not defined for Method and ForAll types)<br> 1240 * Allows unchecked conversions. 1241 */ 1242 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) { 1243 for (List<Type> l = ts; l.nonEmpty(); l = l.tail) 1244 if (!isSubtypeUnchecked(t, l.head, warn)) 1245 return false; 1246 return true; 1247 } 1248 1249 /** 1250 * Are corresponding elements of ts subtypes of ss? If lists are 1251 * of different length, return false. 1252 */ 1253 public boolean isSubtypes(List<Type> ts, List<Type> ss) { 1254 while (ts.tail != null && ss.tail != null 1255 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1256 isSubtype(ts.head, ss.head)) { 1257 ts = ts.tail; 1258 ss = ss.tail; 1259 } 1260 return ts.tail == null && ss.tail == null; 1261 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1262 } 1263 1264 /** 1265 * Are corresponding elements of ts subtypes of ss, allowing 1266 * unchecked conversions? If lists are of different length, 1267 * return false. 1268 **/ 1269 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) { 1270 while (ts.tail != null && ss.tail != null 1271 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1272 isSubtypeUnchecked(ts.head, ss.head, warn)) { 1273 ts = ts.tail; 1274 ss = ss.tail; 1275 } 1276 return ts.tail == null && ss.tail == null; 1277 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1278 } 1279 // </editor-fold> 1280 1281 // <editor-fold defaultstate="collapsed" desc="isSuperType"> 1282 /** 1283 * Is t a supertype of s? 1284 */ 1285 public boolean isSuperType(Type t, Type s) { 1286 switch (t.getTag()) { 1287 case ERROR: 1288 return true; 1289 case UNDETVAR: { 1290 UndetVar undet = (UndetVar)t; 1291 if (t == s || 1292 undet.qtype == s || 1293 s.hasTag(ERROR) || 1294 s.hasTag(BOT)) { 1295 return true; 1296 } 1297 undet.addBound(InferenceBound.LOWER, s, this); 1298 return true; 1299 } 1300 default: 1301 return isSubtype(s, t); 1302 } 1303 } 1304 // </editor-fold> 1305 1306 // <editor-fold defaultstate="collapsed" desc="isSameType"> 1307 /** 1308 * Are corresponding elements of the lists the same type? If 1309 * lists are of different length, return false. 1310 */ 1311 public boolean isSameTypes(List<Type> ts, List<Type> ss) { 1312 while (ts.tail != null && ss.tail != null 1313 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1314 isSameType(ts.head, ss.head)) { 1315 ts = ts.tail; 1316 ss = ss.tail; 1317 } 1318 return ts.tail == null && ss.tail == null; 1319 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1320 } 1321 1322 /** 1323 * A polymorphic signature method (JLS 15.12.3) is a method that 1324 * (i) is declared in the java.lang.invoke.MethodHandle/VarHandle classes; 1325 * (ii) takes a single variable arity parameter; 1326 * (iii) whose declared type is Object[]; 1327 * (iv) has any return type, Object signifying a polymorphic return type; and 1328 * (v) is native. 1329 */ 1330 public boolean isSignaturePolymorphic(MethodSymbol msym) { 1331 List<Type> argtypes = msym.type.getParameterTypes(); 1332 return (msym.flags_field & NATIVE) != 0 && 1333 (msym.owner == syms.methodHandleType.tsym || msym.owner == syms.varHandleType.tsym) && 1334 argtypes.length() == 1 && 1335 argtypes.head.hasTag(TypeTag.ARRAY) && 1336 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym; 1337 } 1338 1339 /** 1340 * Is t the same type as s? 1341 */ 1342 public boolean isSameType(Type t, Type s) { 1343 return isSameTypeVisitor.visit(t, s); 1344 } 1345 // where 1346 1347 /** 1348 * Type-equality relation - type variables are considered 1349 * equals if they share the same object identity. 1350 */ 1351 TypeRelation isSameTypeVisitor = new TypeRelation() { 1352 1353 public Boolean visitType(Type t, Type s) { 1354 if (t.equalsIgnoreMetadata(s)) 1355 return true; 1356 1357 if (s.isPartial()) 1358 return visit(s, t); 1359 1360 switch (t.getTag()) { 1361 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: 1362 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE: 1363 return t.hasTag(s.getTag()); 1364 case TYPEVAR: { 1365 if (s.hasTag(TYPEVAR)) { 1366 //type-substitution does not preserve type-var types 1367 //check that type var symbols and bounds are indeed the same 1368 return t == s; 1369 } 1370 else { 1371 //special case for s == ? super X, where upper(s) = u 1372 //check that u == t, where u has been set by Type.withTypeVar 1373 return s.isSuperBound() && 1374 !s.isExtendsBound() && 1375 visit(t, wildUpperBound(s)); 1376 } 1377 } 1378 default: 1379 throw new AssertionError("isSameType " + t.getTag()); 1380 } 1381 } 1382 1383 @Override 1384 public Boolean visitWildcardType(WildcardType t, Type s) { 1385 if (!s.hasTag(WILDCARD)) { 1386 return false; 1387 } else { 1388 WildcardType t2 = (WildcardType)s; 1389 return (t.kind == t2.kind || (t.isExtendsBound() && s.isExtendsBound())) && 1390 isSameType(t.type, t2.type); 1391 } 1392 } 1393 1394 @Override 1395 public Boolean visitClassType(ClassType t, Type s) { 1396 if (t == s) 1397 return true; 1398 1399 if (s.isPartial()) 1400 return visit(s, t); 1401 1402 if (s.isSuperBound() && !s.isExtendsBound()) 1403 return visit(t, wildUpperBound(s)) && visit(t, wildLowerBound(s)); 1404 1405 if (t.isCompound() && s.isCompound()) { 1406 if (!visit(supertype(t), supertype(s))) 1407 return false; 1408 1409 Map<Symbol,Type> tMap = new HashMap<>(); 1410 for (Type ti : interfaces(t)) { 1411 tMap.put(ti.tsym, ti); 1412 } 1413 for (Type si : interfaces(s)) { 1414 if (!tMap.containsKey(si.tsym)) 1415 return false; 1416 Type ti = tMap.remove(si.tsym); 1417 if (!visit(ti, si)) 1418 return false; 1419 } 1420 return tMap.isEmpty(); 1421 } 1422 return t.tsym == s.tsym 1423 && visit(t.getEnclosingType(), s.getEnclosingType()) 1424 && containsTypeEquivalent(t.getTypeArguments(), s.getTypeArguments()); 1425 } 1426 1427 @Override 1428 public Boolean visitArrayType(ArrayType t, Type s) { 1429 if (t == s) 1430 return true; 1431 1432 if (s.isPartial()) 1433 return visit(s, t); 1434 1435 return s.hasTag(ARRAY) 1436 && containsTypeEquivalent(t.elemtype, elemtype(s)); 1437 } 1438 1439 @Override 1440 public Boolean visitMethodType(MethodType t, Type s) { 1441 // isSameType for methods does not take thrown 1442 // exceptions into account! 1443 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType()); 1444 } 1445 1446 @Override 1447 public Boolean visitPackageType(PackageType t, Type s) { 1448 return t == s; 1449 } 1450 1451 @Override 1452 public Boolean visitForAll(ForAll t, Type s) { 1453 if (!s.hasTag(FORALL)) { 1454 return false; 1455 } 1456 1457 ForAll forAll = (ForAll)s; 1458 return hasSameBounds(t, forAll) 1459 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); 1460 } 1461 1462 @Override 1463 public Boolean visitUndetVar(UndetVar t, Type s) { 1464 if (s.hasTag(WILDCARD)) { 1465 // FIXME, this might be leftovers from before capture conversion 1466 return false; 1467 } 1468 1469 if (t == s || t.qtype == s || s.hasTag(ERROR)) { 1470 return true; 1471 } 1472 1473 t.addBound(InferenceBound.EQ, s, Types.this); 1474 1475 return true; 1476 } 1477 1478 @Override 1479 public Boolean visitErrorType(ErrorType t, Type s) { 1480 return true; 1481 } 1482 }; 1483 1484 // </editor-fold> 1485 1486 // <editor-fold defaultstate="collapsed" desc="Contains Type"> 1487 public boolean containedBy(Type t, Type s) { 1488 switch (t.getTag()) { 1489 case UNDETVAR: 1490 if (s.hasTag(WILDCARD)) { 1491 UndetVar undetvar = (UndetVar)t; 1492 WildcardType wt = (WildcardType)s; 1493 switch(wt.kind) { 1494 case UNBOUND: 1495 break; 1496 case EXTENDS: { 1497 Type bound = wildUpperBound(s); 1498 undetvar.addBound(InferenceBound.UPPER, bound, this); 1499 break; 1500 } 1501 case SUPER: { 1502 Type bound = wildLowerBound(s); 1503 undetvar.addBound(InferenceBound.LOWER, bound, this); 1504 break; 1505 } 1506 } 1507 return true; 1508 } else { 1509 return isSameType(t, s); 1510 } 1511 case ERROR: 1512 return true; 1513 default: 1514 return containsType(s, t); 1515 } 1516 } 1517 1518 boolean containsType(List<Type> ts, List<Type> ss) { 1519 while (ts.nonEmpty() && ss.nonEmpty() 1520 && containsType(ts.head, ss.head)) { 1521 ts = ts.tail; 1522 ss = ss.tail; 1523 } 1524 return ts.isEmpty() && ss.isEmpty(); 1525 } 1526 1527 /** 1528 * Check if t contains s. 1529 * 1530 * <p>T contains S if: 1531 * 1532 * <p>{@code L(T) <: L(S) && U(S) <: U(T)} 1533 * 1534 * <p>This relation is only used by ClassType.isSubtype(), that 1535 * is, 1536 * 1537 * <p>{@code C<S> <: C<T> if T contains S.} 1538 * 1539 * <p>Because of F-bounds, this relation can lead to infinite 1540 * recursion. Thus we must somehow break that recursion. Notice 1541 * that containsType() is only called from ClassType.isSubtype(). 1542 * Since the arguments have already been checked against their 1543 * bounds, we know: 1544 * 1545 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)} 1546 * 1547 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)} 1548 * 1549 * @param t a type 1550 * @param s a type 1551 */ 1552 public boolean containsType(Type t, Type s) { 1553 return containsType.visit(t, s); 1554 } 1555 // where 1556 private TypeRelation containsType = new TypeRelation() { 1557 1558 public Boolean visitType(Type t, Type s) { 1559 if (s.isPartial()) 1560 return containedBy(s, t); 1561 else 1562 return isSameType(t, s); 1563 } 1564 1565 // void debugContainsType(WildcardType t, Type s) { 1566 // System.err.println(); 1567 // System.err.format(" does %s contain %s?%n", t, s); 1568 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n", 1569 // wildUpperBound(s), s, t, wildUpperBound(t), 1570 // t.isSuperBound() 1571 // || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t))); 1572 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n", 1573 // wildLowerBound(t), t, s, wildLowerBound(s), 1574 // t.isExtendsBound() 1575 // || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))); 1576 // System.err.println(); 1577 // } 1578 1579 @Override 1580 public Boolean visitWildcardType(WildcardType t, Type s) { 1581 if (s.isPartial()) 1582 return containedBy(s, t); 1583 else { 1584 // debugContainsType(t, s); 1585 return isSameWildcard(t, s) 1586 || isCaptureOf(s, t) 1587 || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) && 1588 (t.isSuperBound() || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t)))); 1589 } 1590 } 1591 1592 @Override 1593 public Boolean visitUndetVar(UndetVar t, Type s) { 1594 if (!s.hasTag(WILDCARD)) { 1595 return isSameType(t, s); 1596 } else { 1597 return false; 1598 } 1599 } 1600 1601 @Override 1602 public Boolean visitErrorType(ErrorType t, Type s) { 1603 return true; 1604 } 1605 }; 1606 1607 public boolean isCaptureOf(Type s, WildcardType t) { 1608 if (!s.hasTag(TYPEVAR) || !((TypeVar)s).isCaptured()) 1609 return false; 1610 return isSameWildcard(t, ((CapturedType)s).wildcard); 1611 } 1612 1613 public boolean isSameWildcard(WildcardType t, Type s) { 1614 if (!s.hasTag(WILDCARD)) 1615 return false; 1616 WildcardType w = (WildcardType)s; 1617 return w.kind == t.kind && w.type == t.type; 1618 } 1619 1620 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) { 1621 while (ts.nonEmpty() && ss.nonEmpty() 1622 && containsTypeEquivalent(ts.head, ss.head)) { 1623 ts = ts.tail; 1624 ss = ss.tail; 1625 } 1626 return ts.isEmpty() && ss.isEmpty(); 1627 } 1628 // </editor-fold> 1629 1630 // <editor-fold defaultstate="collapsed" desc="isCastable"> 1631 public boolean isCastable(Type t, Type s) { 1632 return isCastable(t, s, noWarnings); 1633 } 1634 1635 /** 1636 * Is t castable to s?<br> 1637 * s is assumed to be an erased type.<br> 1638 * (not defined for Method and ForAll types). 1639 */ 1640 public boolean isCastable(Type t, Type s, Warner warn) { 1641 // if same type 1642 if (t == s) 1643 return true; 1644 // if one of the types is primitive 1645 if (t.isPrimitive() != s.isPrimitive()) { 1646 t = skipTypeVars(t, false); 1647 return (isConvertible(t, s, warn) 1648 || (s.isPrimitive() && 1649 isSubtype(boxedClass(s).type, t))); 1650 } 1651 boolean result; 1652 if (warn != warnStack.head) { 1653 try { 1654 warnStack = warnStack.prepend(warn); 1655 checkUnsafeVarargsConversion(t, s, warn); 1656 result = isCastable.visit(t,s); 1657 } finally { 1658 warnStack = warnStack.tail; 1659 } 1660 } else { 1661 result = isCastable.visit(t,s); 1662 } 1663 if (result && t.hasTag(CLASS) && t.tsym.kind.matches(Kinds.KindSelector.TYP) 1664 && s.hasTag(CLASS) && s.tsym.kind.matches(Kinds.KindSelector.TYP) 1665 && (t.tsym.isSealed() || s.tsym.isSealed())) { 1666 return (t.isCompound() || s.isCompound()) ? 1667 true : 1668 !(new DisjointChecker().areDisjoint((ClassSymbol)t.tsym, (ClassSymbol)s.tsym)); 1669 } 1670 return result; 1671 } 1672 // where 1673 class DisjointChecker { 1674 Set<Pair<ClassSymbol, ClassSymbol>> pairsSeen = new HashSet<>(); 1675 /* there are three cases for ts and ss: 1676 * - one is a class and the other one is an interface (case I) 1677 * - both are classes (case II) 1678 * - both are interfaces (case III) 1679 * all those cases are covered in JLS 23, section: "5.1.6.1 Allowed Narrowing Reference Conversion" 1680 */ 1681 private boolean areDisjoint(ClassSymbol ts, ClassSymbol ss) { 1682 Pair<ClassSymbol, ClassSymbol> newPair = new Pair<>(ts, ss); 1683 /* if we are seeing the same pair again then there is an issue with the sealed hierarchy 1684 * bail out, a detailed error will be reported downstream 1685 */ 1686 if (!pairsSeen.add(newPair)) 1687 return false; 1688 1689 if (ts.isInterface() != ss.isInterface()) { // case I: one is a class and the other one is an interface 1690 ClassSymbol isym = ts.isInterface() ? ts : ss; // isym is the interface and csym the class 1691 ClassSymbol csym = isym == ts ? ss : ts; 1692 if (!isSubtype(erasure(csym.type), erasure(isym.type))) { 1693 if (csym.isFinal()) { 1694 return true; 1695 } else if (csym.isSealed()) { 1696 return areDisjoint(isym, csym.getPermittedSubclasses()); 1697 } else if (isym.isSealed()) { 1698 // if the class is not final and not sealed then it has to be freely extensible 1699 return areDisjoint(csym, isym.getPermittedSubclasses()); 1700 } 1701 } // now both are classes or both are interfaces 1702 } else if (!ts.isInterface()) { // case II: both are classes 1703 return !isSubtype(erasure(ss.type), erasure(ts.type)) && !isSubtype(erasure(ts.type), erasure(ss.type)); 1704 } else { // case III: both are interfaces 1705 if (!isSubtype(erasure(ts.type), erasure(ss.type)) && !isSubtype(erasure(ss.type), erasure(ts.type))) { 1706 if (ts.isSealed()) { 1707 return areDisjoint(ss, ts.getPermittedSubclasses()); 1708 } else if (ss.isSealed()) { 1709 return areDisjoint(ts, ss.getPermittedSubclasses()); 1710 } 1711 } 1712 } 1713 // at this point we haven't been able to statically prove that the classes or interfaces are disjoint 1714 return false; 1715 } 1716 1717 boolean areDisjoint(ClassSymbol csym, List<Type> permittedSubtypes) { 1718 return permittedSubtypes.stream().allMatch(psubtype -> areDisjoint(csym, (ClassSymbol) psubtype.tsym)); 1719 } 1720 } 1721 1722 private TypeRelation isCastable = new TypeRelation() { 1723 1724 public Boolean visitType(Type t, Type s) { 1725 if (s.hasTag(ERROR) || t.hasTag(NONE)) 1726 return true; 1727 1728 switch (t.getTag()) { 1729 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: 1730 case DOUBLE: 1731 return s.isNumeric(); 1732 case BOOLEAN: 1733 return s.hasTag(BOOLEAN); 1734 case VOID: 1735 return false; 1736 case BOT: 1737 return isSubtype(t, s); 1738 default: 1739 throw new AssertionError(); 1740 } 1741 } 1742 1743 @Override 1744 public Boolean visitWildcardType(WildcardType t, Type s) { 1745 return isCastable(wildUpperBound(t), s, warnStack.head); 1746 } 1747 1748 @Override 1749 public Boolean visitClassType(ClassType t, Type s) { 1750 if (s.hasTag(ERROR) || s.hasTag(BOT)) 1751 return true; 1752 1753 if (s.hasTag(TYPEVAR)) { 1754 if (isCastable(t, s.getUpperBound(), noWarnings)) { 1755 warnStack.head.warn(LintCategory.UNCHECKED); 1756 return true; 1757 } else { 1758 return false; 1759 } 1760 } 1761 1762 if (t.isCompound() || s.isCompound()) { 1763 return !t.isCompound() ? 1764 visitCompoundType((ClassType)s, t, true) : 1765 visitCompoundType(t, s, false); 1766 } 1767 1768 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) { 1769 boolean upcast; 1770 if ((upcast = isSubtype(erasure(t), erasure(s))) 1771 || isSubtype(erasure(s), erasure(t))) { 1772 if (!upcast && s.hasTag(ARRAY)) { 1773 if (!isReifiable(s)) 1774 warnStack.head.warn(LintCategory.UNCHECKED); 1775 return true; 1776 } else if (s.isRaw()) { 1777 return true; 1778 } else if (t.isRaw()) { 1779 if (!isUnbounded(s)) 1780 warnStack.head.warn(LintCategory.UNCHECKED); 1781 return true; 1782 } 1783 // Assume |a| <: |b| 1784 final Type a = upcast ? t : s; 1785 final Type b = upcast ? s : t; 1786 final boolean HIGH = true; 1787 final boolean LOW = false; 1788 final boolean DONT_REWRITE_TYPEVARS = false; 1789 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS); 1790 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS); 1791 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS); 1792 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS); 1793 Type lowSub = asSub(bLow, aLow.tsym); 1794 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); 1795 if (highSub == null) { 1796 final boolean REWRITE_TYPEVARS = true; 1797 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS); 1798 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS); 1799 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS); 1800 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS); 1801 lowSub = asSub(bLow, aLow.tsym); 1802 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); 1803 } 1804 if (highSub != null) { 1805 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) { 1806 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym); 1807 } 1808 if (!disjointTypes(aHigh.allparams(), highSub.allparams()) 1809 && !disjointTypes(aHigh.allparams(), lowSub.allparams()) 1810 && !disjointTypes(aLow.allparams(), highSub.allparams()) 1811 && !disjointTypes(aLow.allparams(), lowSub.allparams())) { 1812 if (upcast ? giveWarning(a, b) : 1813 giveWarning(b, a)) 1814 warnStack.head.warn(LintCategory.UNCHECKED); 1815 return true; 1816 } 1817 } 1818 if (isReifiable(s)) 1819 return isSubtypeUnchecked(a, b); 1820 else 1821 return isSubtypeUnchecked(a, b, warnStack.head); 1822 } 1823 1824 // Sidecast 1825 if (s.hasTag(CLASS)) { 1826 if ((s.tsym.flags() & INTERFACE) != 0) { 1827 return ((t.tsym.flags() & FINAL) == 0) 1828 ? sideCast(t, s, warnStack.head) 1829 : sideCastFinal(t, s, warnStack.head); 1830 } else if ((t.tsym.flags() & INTERFACE) != 0) { 1831 return ((s.tsym.flags() & FINAL) == 0) 1832 ? sideCast(t, s, warnStack.head) 1833 : sideCastFinal(t, s, warnStack.head); 1834 } else { 1835 // unrelated class types 1836 return false; 1837 } 1838 } 1839 } 1840 return false; 1841 } 1842 1843 boolean visitCompoundType(ClassType ct, Type s, boolean reverse) { 1844 Warner warn = noWarnings; 1845 for (Type c : directSupertypes(ct)) { 1846 warn.clear(); 1847 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn)) 1848 return false; 1849 } 1850 if (warn.hasLint(LintCategory.UNCHECKED)) 1851 warnStack.head.warn(LintCategory.UNCHECKED); 1852 return true; 1853 } 1854 1855 @Override 1856 public Boolean visitArrayType(ArrayType t, Type s) { 1857 switch (s.getTag()) { 1858 case ERROR: 1859 case BOT: 1860 return true; 1861 case TYPEVAR: 1862 if (isCastable(s, t, noWarnings)) { 1863 warnStack.head.warn(LintCategory.UNCHECKED); 1864 return true; 1865 } else { 1866 return false; 1867 } 1868 case CLASS: 1869 return isSubtype(t, s); 1870 case ARRAY: 1871 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) { 1872 return elemtype(t).hasTag(elemtype(s).getTag()); 1873 } else { 1874 return isCastable(elemtype(t), elemtype(s), warnStack.head); 1875 } 1876 default: 1877 return false; 1878 } 1879 } 1880 1881 @Override 1882 public Boolean visitTypeVar(TypeVar t, Type s) { 1883 switch (s.getTag()) { 1884 case ERROR: 1885 case BOT: 1886 return true; 1887 case TYPEVAR: 1888 if (isSubtype(t, s)) { 1889 return true; 1890 } else if (isCastable(t.getUpperBound(), s, noWarnings)) { 1891 warnStack.head.warn(LintCategory.UNCHECKED); 1892 return true; 1893 } else { 1894 return false; 1895 } 1896 default: 1897 return isCastable(t.getUpperBound(), s, warnStack.head); 1898 } 1899 } 1900 1901 @Override 1902 public Boolean visitErrorType(ErrorType t, Type s) { 1903 return true; 1904 } 1905 }; 1906 // </editor-fold> 1907 1908 // <editor-fold defaultstate="collapsed" desc="disjointTypes"> 1909 public boolean disjointTypes(List<Type> ts, List<Type> ss) { 1910 while (ts.tail != null && ss.tail != null) { 1911 if (disjointType(ts.head, ss.head)) return true; 1912 ts = ts.tail; 1913 ss = ss.tail; 1914 } 1915 return false; 1916 } 1917 1918 /** 1919 * Two types or wildcards are considered disjoint if it can be 1920 * proven that no type can be contained in both. It is 1921 * conservative in that it is allowed to say that two types are 1922 * not disjoint, even though they actually are. 1923 * 1924 * The type {@code C<X>} is castable to {@code C<Y>} exactly if 1925 * {@code X} and {@code Y} are not disjoint. 1926 */ 1927 public boolean disjointType(Type t, Type s) { 1928 return disjointType.visit(t, s); 1929 } 1930 // where 1931 private TypeRelation disjointType = new TypeRelation() { 1932 1933 private Set<TypePair> cache = new HashSet<>(); 1934 1935 @Override 1936 public Boolean visitType(Type t, Type s) { 1937 if (s.hasTag(WILDCARD)) 1938 return visit(s, t); 1939 else 1940 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t); 1941 } 1942 1943 private boolean isCastableRecursive(Type t, Type s) { 1944 TypePair pair = new TypePair(t, s); 1945 if (cache.add(pair)) { 1946 try { 1947 return Types.this.isCastable(t, s); 1948 } finally { 1949 cache.remove(pair); 1950 } 1951 } else { 1952 return true; 1953 } 1954 } 1955 1956 private boolean notSoftSubtypeRecursive(Type t, Type s) { 1957 TypePair pair = new TypePair(t, s); 1958 if (cache.add(pair)) { 1959 try { 1960 return Types.this.notSoftSubtype(t, s); 1961 } finally { 1962 cache.remove(pair); 1963 } 1964 } else { 1965 return false; 1966 } 1967 } 1968 1969 @Override 1970 public Boolean visitWildcardType(WildcardType t, Type s) { 1971 if (t.isUnbound()) 1972 return false; 1973 1974 if (!s.hasTag(WILDCARD)) { 1975 if (t.isExtendsBound()) 1976 return notSoftSubtypeRecursive(s, t.type); 1977 else 1978 return notSoftSubtypeRecursive(t.type, s); 1979 } 1980 1981 if (s.isUnbound()) 1982 return false; 1983 1984 if (t.isExtendsBound()) { 1985 if (s.isExtendsBound()) 1986 return !isCastableRecursive(t.type, wildUpperBound(s)); 1987 else if (s.isSuperBound()) 1988 return notSoftSubtypeRecursive(wildLowerBound(s), t.type); 1989 } else if (t.isSuperBound()) { 1990 if (s.isExtendsBound()) 1991 return notSoftSubtypeRecursive(t.type, wildUpperBound(s)); 1992 } 1993 return false; 1994 } 1995 }; 1996 // </editor-fold> 1997 1998 // <editor-fold defaultstate="collapsed" desc="cvarLowerBounds"> 1999 public List<Type> cvarLowerBounds(List<Type> ts) { 2000 return ts.map(cvarLowerBoundMapping); 2001 } 2002 private final TypeMapping<Void> cvarLowerBoundMapping = new TypeMapping<Void>() { 2003 @Override 2004 public Type visitCapturedType(CapturedType t, Void _unused) { 2005 return cvarLowerBound(t); 2006 } 2007 }; 2008 // </editor-fold> 2009 2010 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype"> 2011 /** 2012 * This relation answers the question: is impossible that 2013 * something of type `t' can be a subtype of `s'? This is 2014 * different from the question "is `t' not a subtype of `s'?" 2015 * when type variables are involved: Integer is not a subtype of T 2016 * where {@code <T extends Number>} but it is not true that Integer cannot 2017 * possibly be a subtype of T. 2018 */ 2019 public boolean notSoftSubtype(Type t, Type s) { 2020 if (t == s) return false; 2021 if (t.hasTag(TYPEVAR)) { 2022 TypeVar tv = (TypeVar) t; 2023 return !isCastable(tv.getUpperBound(), 2024 relaxBound(s), 2025 noWarnings); 2026 } 2027 if (!s.hasTag(WILDCARD)) 2028 s = cvarUpperBound(s); 2029 2030 return !isSubtype(t, relaxBound(s)); 2031 } 2032 2033 private Type relaxBound(Type t) { 2034 return (t.hasTag(TYPEVAR)) ? 2035 rewriteQuantifiers(skipTypeVars(t, false), true, true) : 2036 t; 2037 } 2038 // </editor-fold> 2039 2040 // <editor-fold defaultstate="collapsed" desc="isReifiable"> 2041 public boolean isReifiable(Type t) { 2042 return isReifiable.visit(t); 2043 } 2044 // where 2045 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() { 2046 2047 public Boolean visitType(Type t, Void ignored) { 2048 return true; 2049 } 2050 2051 @Override 2052 public Boolean visitClassType(ClassType t, Void ignored) { 2053 if (t.isCompound()) 2054 return false; 2055 else { 2056 if (!t.isParameterized()) 2057 return true; 2058 2059 for (Type param : t.allparams()) { 2060 if (!param.isUnbound()) 2061 return false; 2062 } 2063 return true; 2064 } 2065 } 2066 2067 @Override 2068 public Boolean visitArrayType(ArrayType t, Void ignored) { 2069 return visit(t.elemtype); 2070 } 2071 2072 @Override 2073 public Boolean visitTypeVar(TypeVar t, Void ignored) { 2074 return false; 2075 } 2076 }; 2077 // </editor-fold> 2078 2079 // <editor-fold defaultstate="collapsed" desc="Array Utils"> 2080 public boolean isArray(Type t) { 2081 while (t.hasTag(WILDCARD)) 2082 t = wildUpperBound(t); 2083 return t.hasTag(ARRAY); 2084 } 2085 2086 /** 2087 * The element type of an array. 2088 */ 2089 public Type elemtype(Type t) { 2090 switch (t.getTag()) { 2091 case WILDCARD: 2092 return elemtype(wildUpperBound(t)); 2093 case ARRAY: 2094 return ((ArrayType)t).elemtype; 2095 case FORALL: 2096 return elemtype(((ForAll)t).qtype); 2097 case ERROR: 2098 return t; 2099 default: 2100 return null; 2101 } 2102 } 2103 2104 public Type elemtypeOrType(Type t) { 2105 Type elemtype = elemtype(t); 2106 return elemtype != null ? 2107 elemtype : 2108 t; 2109 } 2110 2111 /** 2112 * Mapping to take element type of an arraytype 2113 */ 2114 private TypeMapping<Void> elemTypeFun = new TypeMapping<Void>() { 2115 @Override 2116 public Type visitArrayType(ArrayType t, Void _unused) { 2117 return t.elemtype; 2118 } 2119 2120 @Override 2121 public Type visitTypeVar(TypeVar t, Void _unused) { 2122 return visit(skipTypeVars(t, false)); 2123 } 2124 }; 2125 2126 /** 2127 * The number of dimensions of an array type. 2128 */ 2129 public int dimensions(Type t) { 2130 int result = 0; 2131 while (t.hasTag(ARRAY)) { 2132 result++; 2133 t = elemtype(t); 2134 } 2135 return result; 2136 } 2137 2138 /** 2139 * Returns an ArrayType with the component type t 2140 * 2141 * @param t The component type of the ArrayType 2142 * @return the ArrayType for the given component 2143 */ 2144 public ArrayType makeArrayType(Type t) { 2145 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) { 2146 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString()); 2147 } 2148 return new ArrayType(t, syms.arrayClass); 2149 } 2150 // </editor-fold> 2151 2152 // <editor-fold defaultstate="collapsed" desc="asSuper"> 2153 /** 2154 * Return the (most specific) base type of t that starts with the 2155 * given symbol. If none exists, return null. 2156 * 2157 * Caveat Emptor: Since javac represents the class of all arrays with a singleton 2158 * symbol Symtab.arrayClass, which by being a singleton cannot hold any discriminant, 2159 * this method could yield surprising answers when invoked on arrays. For example when 2160 * invoked with t being byte [] and sym being t.sym itself, asSuper would answer null. 2161 * 2162 * @param t a type 2163 * @param sym a symbol 2164 */ 2165 public Type asSuper(Type t, Symbol sym) { 2166 /* Some examples: 2167 * 2168 * (Enum<E>, Comparable) => Comparable<E> 2169 * (c.s.s.d.AttributeTree.ValueKind, Enum) => Enum<c.s.s.d.AttributeTree.ValueKind> 2170 * (c.s.s.t.ExpressionTree, c.s.s.t.Tree) => c.s.s.t.Tree 2171 * (j.u.List<capture#160 of ? extends c.s.s.d.DocTree>, Iterable) => 2172 * Iterable<capture#160 of ? extends c.s.s.d.DocTree> 2173 */ 2174 if (sym.type == syms.objectType) { //optimization 2175 return syms.objectType; 2176 } 2177 return asSuper.visit(t, sym); 2178 } 2179 // where 2180 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() { 2181 2182 private Set<Symbol> seenTypes = new HashSet<>(); 2183 2184 public Type visitType(Type t, Symbol sym) { 2185 return null; 2186 } 2187 2188 @Override 2189 public Type visitClassType(ClassType t, Symbol sym) { 2190 if (t.tsym == sym) 2191 return t; 2192 2193 Symbol c = t.tsym; 2194 if (!seenTypes.add(c)) { 2195 return null; 2196 } 2197 try { 2198 Type st = supertype(t); 2199 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) { 2200 Type x = asSuper(st, sym); 2201 if (x != null) 2202 return x; 2203 } 2204 if ((sym.flags() & INTERFACE) != 0) { 2205 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { 2206 if (!l.head.hasTag(ERROR)) { 2207 Type x = asSuper(l.head, sym); 2208 if (x != null) 2209 return x; 2210 } 2211 } 2212 } 2213 return null; 2214 } finally { 2215 seenTypes.remove(c); 2216 } 2217 } 2218 2219 @Override 2220 public Type visitArrayType(ArrayType t, Symbol sym) { 2221 return isSubtype(t, sym.type) ? sym.type : null; 2222 } 2223 2224 @Override 2225 public Type visitTypeVar(TypeVar t, Symbol sym) { 2226 if (t.tsym == sym) 2227 return t; 2228 else 2229 return asSuper(t.getUpperBound(), sym); 2230 } 2231 2232 @Override 2233 public Type visitErrorType(ErrorType t, Symbol sym) { 2234 return t; 2235 } 2236 }; 2237 2238 /** 2239 * Return the base type of t or any of its outer types that starts 2240 * with the given symbol. If none exists, return null. 2241 * 2242 * @param t a type 2243 * @param sym a symbol 2244 */ 2245 public Type asOuterSuper(Type t, Symbol sym) { 2246 switch (t.getTag()) { 2247 case CLASS: 2248 do { 2249 Type s = asSuper(t, sym); 2250 if (s != null) return s; 2251 t = t.getEnclosingType(); 2252 } while (t.hasTag(CLASS)); 2253 return null; 2254 case ARRAY: 2255 return isSubtype(t, sym.type) ? sym.type : null; 2256 case TYPEVAR: 2257 return asSuper(t, sym); 2258 case ERROR: 2259 return t; 2260 default: 2261 return null; 2262 } 2263 } 2264 2265 /** 2266 * Return the base type of t or any of its enclosing types that 2267 * starts with the given symbol. If none exists, return null. 2268 * 2269 * @param t a type 2270 * @param sym a symbol 2271 */ 2272 public Type asEnclosingSuper(Type t, Symbol sym) { 2273 switch (t.getTag()) { 2274 case CLASS: 2275 do { 2276 Type s = asSuper(t, sym); 2277 if (s != null) return s; 2278 Type outer = t.getEnclosingType(); 2279 t = (outer.hasTag(CLASS)) ? outer : 2280 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type : 2281 Type.noType; 2282 } while (t.hasTag(CLASS)); 2283 return null; 2284 case ARRAY: 2285 return isSubtype(t, sym.type) ? sym.type : null; 2286 case TYPEVAR: 2287 return asSuper(t, sym); 2288 case ERROR: 2289 return t; 2290 default: 2291 return null; 2292 } 2293 } 2294 // </editor-fold> 2295 2296 // <editor-fold defaultstate="collapsed" desc="memberType"> 2297 /** 2298 * The type of given symbol, seen as a member of t. 2299 * 2300 * @param t a type 2301 * @param sym a symbol 2302 */ 2303 public Type memberType(Type t, Symbol sym) { 2304 return (sym.flags() & STATIC) != 0 2305 ? sym.type 2306 : memberType.visit(t, sym); 2307 } 2308 // where 2309 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() { 2310 2311 public Type visitType(Type t, Symbol sym) { 2312 return sym.type; 2313 } 2314 2315 @Override 2316 public Type visitWildcardType(WildcardType t, Symbol sym) { 2317 return memberType(wildUpperBound(t), sym); 2318 } 2319 2320 @Override 2321 public Type visitClassType(ClassType t, Symbol sym) { 2322 Symbol owner = sym.owner; 2323 long flags = sym.flags(); 2324 if (((flags & STATIC) == 0) && owner.type.isParameterized()) { 2325 Type base = asOuterSuper(t, owner); 2326 //if t is an intersection type T = CT & I1 & I2 ... & In 2327 //its supertypes CT, I1, ... In might contain wildcards 2328 //so we need to go through capture conversion 2329 base = t.isCompound() ? capture(base) : base; 2330 if (base != null) { 2331 List<Type> ownerParams = owner.type.allparams(); 2332 List<Type> baseParams = base.allparams(); 2333 if (ownerParams.nonEmpty()) { 2334 if (baseParams.isEmpty()) { 2335 // then base is a raw type 2336 return erasure(sym.type); 2337 } else { 2338 return subst(sym.type, ownerParams, baseParams); 2339 } 2340 } 2341 } 2342 } 2343 return sym.type; 2344 } 2345 2346 @Override 2347 public Type visitTypeVar(TypeVar t, Symbol sym) { 2348 return memberType(t.getUpperBound(), sym); 2349 } 2350 2351 @Override 2352 public Type visitErrorType(ErrorType t, Symbol sym) { 2353 return t; 2354 } 2355 }; 2356 // </editor-fold> 2357 2358 // <editor-fold defaultstate="collapsed" desc="isAssignable"> 2359 public boolean isAssignable(Type t, Type s) { 2360 return isAssignable(t, s, noWarnings); 2361 } 2362 2363 /** 2364 * Is t assignable to s?<br> 2365 * Equivalent to subtype except for constant values and raw 2366 * types.<br> 2367 * (not defined for Method and ForAll types) 2368 */ 2369 public boolean isAssignable(Type t, Type s, Warner warn) { 2370 if (t.hasTag(ERROR)) 2371 return true; 2372 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) { 2373 int value = ((Number)t.constValue()).intValue(); 2374 switch (s.getTag()) { 2375 case BYTE: 2376 case CHAR: 2377 case SHORT: 2378 case INT: 2379 if (s.getTag().checkRange(value)) 2380 return true; 2381 break; 2382 case CLASS: 2383 switch (unboxedType(s).getTag()) { 2384 case BYTE: 2385 case CHAR: 2386 case SHORT: 2387 return isAssignable(t, unboxedType(s), warn); 2388 } 2389 break; 2390 } 2391 } 2392 return isConvertible(t, s, warn); 2393 } 2394 // </editor-fold> 2395 2396 // <editor-fold defaultstate="collapsed" desc="erasure"> 2397 /** 2398 * The erasure of t {@code |t|} -- the type that results when all 2399 * type parameters in t are deleted. 2400 */ 2401 public Type erasure(Type t) { 2402 return eraseNotNeeded(t) ? t : erasure(t, false); 2403 } 2404 //where 2405 private boolean eraseNotNeeded(Type t) { 2406 // We don't want to erase primitive types and String type as that 2407 // operation is idempotent. Also, erasing these could result in loss 2408 // of information such as constant values attached to such types. 2409 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym); 2410 } 2411 2412 private Type erasure(Type t, boolean recurse) { 2413 if (t.isPrimitive()) { 2414 return t; /* fast special case */ 2415 } else { 2416 Type out = erasure.visit(t, recurse); 2417 return out; 2418 } 2419 } 2420 // where 2421 private TypeMapping<Boolean> erasure = new StructuralTypeMapping<Boolean>() { 2422 @SuppressWarnings("fallthrough") 2423 private Type combineMetadata(final Type s, 2424 final Type t) { 2425 if (t.getMetadata().nonEmpty()) { 2426 switch (s.getTag()) { 2427 case CLASS: 2428 if (s instanceof UnionClassType || 2429 s instanceof IntersectionClassType) { 2430 return s; 2431 } 2432 //fall-through 2433 case BYTE, CHAR, SHORT, LONG, FLOAT, INT, DOUBLE, BOOLEAN, 2434 ARRAY, MODULE, TYPEVAR, WILDCARD, BOT: 2435 return s.dropMetadata(Annotations.class); 2436 case VOID, METHOD, PACKAGE, FORALL, DEFERRED, 2437 NONE, ERROR, UNDETVAR, UNINITIALIZED_THIS, 2438 UNINITIALIZED_OBJECT: 2439 return s; 2440 default: 2441 throw new AssertionError(s.getTag().name()); 2442 } 2443 } else { 2444 return s; 2445 } 2446 } 2447 2448 public Type visitType(Type t, Boolean recurse) { 2449 if (t.isPrimitive()) 2450 return t; /*fast special case*/ 2451 else { 2452 //other cases already handled 2453 return combineMetadata(t, t); 2454 } 2455 } 2456 2457 @Override 2458 public Type visitWildcardType(WildcardType t, Boolean recurse) { 2459 Type erased = erasure(wildUpperBound(t), recurse); 2460 return combineMetadata(erased, t); 2461 } 2462 2463 @Override 2464 public Type visitClassType(ClassType t, Boolean recurse) { 2465 Type erased = t.tsym.erasure(Types.this); 2466 if (recurse) { 2467 erased = new ErasedClassType(erased.getEnclosingType(),erased.tsym, 2468 t.dropMetadata(Annotations.class).getMetadata()); 2469 return erased; 2470 } else { 2471 return combineMetadata(erased, t); 2472 } 2473 } 2474 2475 @Override 2476 public Type visitTypeVar(TypeVar t, Boolean recurse) { 2477 Type erased = erasure(t.getUpperBound(), recurse); 2478 return combineMetadata(erased, t); 2479 } 2480 }; 2481 2482 public List<Type> erasure(List<Type> ts) { 2483 return erasure.visit(ts, false); 2484 } 2485 2486 public Type erasureRecursive(Type t) { 2487 return erasure(t, true); 2488 } 2489 2490 public List<Type> erasureRecursive(List<Type> ts) { 2491 return erasure.visit(ts, true); 2492 } 2493 // </editor-fold> 2494 2495 // <editor-fold defaultstate="collapsed" desc="makeIntersectionType"> 2496 /** 2497 * Make an intersection type from non-empty list of types. The list should be ordered according to 2498 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. Note that this might cause a symbol completion. 2499 * Hence, this version of makeIntersectionType may not be called during a classfile read. 2500 * 2501 * @param bounds the types from which the intersection type is formed 2502 */ 2503 public IntersectionClassType makeIntersectionType(List<Type> bounds) { 2504 return makeIntersectionType(bounds, bounds.head.tsym.isInterface()); 2505 } 2506 2507 /** 2508 * Make an intersection type from non-empty list of types. The list should be ordered according to 2509 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. This does not cause symbol completion as 2510 * an extra parameter indicates as to whether all bounds are interfaces - in which case the 2511 * supertype is implicitly assumed to be 'Object'. 2512 * 2513 * @param bounds the types from which the intersection type is formed 2514 * @param allInterfaces are all bounds interface types? 2515 */ 2516 public IntersectionClassType makeIntersectionType(List<Type> bounds, boolean allInterfaces) { 2517 Assert.check(bounds.nonEmpty()); 2518 Type firstExplicitBound = bounds.head; 2519 if (allInterfaces) { 2520 bounds = bounds.prepend(syms.objectType); 2521 } 2522 ClassSymbol bc = 2523 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC, 2524 Type.moreInfo 2525 ? names.fromString(bounds.toString()) 2526 : names.empty, 2527 null, 2528 syms.noSymbol); 2529 IntersectionClassType intersectionType = new IntersectionClassType(bounds, bc, allInterfaces); 2530 bc.type = intersectionType; 2531 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ? 2532 syms.objectType : // error condition, recover 2533 erasure(firstExplicitBound); 2534 bc.members_field = WriteableScope.create(bc); 2535 return intersectionType; 2536 } 2537 // </editor-fold> 2538 2539 // <editor-fold defaultstate="collapsed" desc="supertype"> 2540 public Type supertype(Type t) { 2541 return supertype.visit(t); 2542 } 2543 // where 2544 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() { 2545 2546 public Type visitType(Type t, Void ignored) { 2547 // A note on wildcards: there is no good way to 2548 // determine a supertype for a lower-bounded wildcard. 2549 return Type.noType; 2550 } 2551 2552 @Override 2553 public Type visitClassType(ClassType t, Void ignored) { 2554 if (t.supertype_field == null) { 2555 Type supertype = ((ClassSymbol)t.tsym).getSuperclass(); 2556 // An interface has no superclass; its supertype is Object. 2557 if (t.isInterface()) 2558 supertype = ((ClassType)t.tsym.type).supertype_field; 2559 if (t.supertype_field == null) { 2560 List<Type> actuals = classBound(t).allparams(); 2561 List<Type> formals = t.tsym.type.allparams(); 2562 if (t.hasErasedSupertypes()) { 2563 t.supertype_field = erasureRecursive(supertype); 2564 } else if (formals.nonEmpty()) { 2565 t.supertype_field = subst(supertype, formals, actuals); 2566 } 2567 else { 2568 t.supertype_field = supertype; 2569 } 2570 } 2571 } 2572 return t.supertype_field; 2573 } 2574 2575 /** 2576 * The supertype is always a class type. If the type 2577 * variable's bounds start with a class type, this is also 2578 * the supertype. Otherwise, the supertype is 2579 * java.lang.Object. 2580 */ 2581 @Override 2582 public Type visitTypeVar(TypeVar t, Void ignored) { 2583 if (t.getUpperBound().hasTag(TYPEVAR) || 2584 (!t.getUpperBound().isCompound() && !t.getUpperBound().isInterface())) { 2585 return t.getUpperBound(); 2586 } else { 2587 return supertype(t.getUpperBound()); 2588 } 2589 } 2590 2591 @Override 2592 public Type visitArrayType(ArrayType t, Void ignored) { 2593 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType)) 2594 return arraySuperType(); 2595 else 2596 return new ArrayType(supertype(t.elemtype), t.tsym); 2597 } 2598 2599 @Override 2600 public Type visitErrorType(ErrorType t, Void ignored) { 2601 return Type.noType; 2602 } 2603 }; 2604 // </editor-fold> 2605 2606 // <editor-fold defaultstate="collapsed" desc="interfaces"> 2607 /** 2608 * Return the interfaces implemented by this class. 2609 */ 2610 public List<Type> interfaces(Type t) { 2611 return interfaces.visit(t); 2612 } 2613 // where 2614 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() { 2615 2616 public List<Type> visitType(Type t, Void ignored) { 2617 return List.nil(); 2618 } 2619 2620 @Override 2621 public List<Type> visitClassType(ClassType t, Void ignored) { 2622 if (t.interfaces_field == null) { 2623 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces(); 2624 if (t.interfaces_field == null) { 2625 // If t.interfaces_field is null, then t must 2626 // be a parameterized type (not to be confused 2627 // with a generic type declaration). 2628 // Terminology: 2629 // Parameterized type: List<String> 2630 // Generic type declaration: class List<E> { ... } 2631 // So t corresponds to List<String> and 2632 // t.tsym.type corresponds to List<E>. 2633 // The reason t must be parameterized type is 2634 // that completion will happen as a side 2635 // effect of calling 2636 // ClassSymbol.getInterfaces. Since 2637 // t.interfaces_field is null after 2638 // completion, we can assume that t is not the 2639 // type of a class/interface declaration. 2640 Assert.check(t != t.tsym.type, t); 2641 List<Type> actuals = t.allparams(); 2642 List<Type> formals = t.tsym.type.allparams(); 2643 if (t.hasErasedSupertypes()) { 2644 t.interfaces_field = erasureRecursive(interfaces); 2645 } else if (formals.nonEmpty()) { 2646 t.interfaces_field = subst(interfaces, formals, actuals); 2647 } 2648 else { 2649 t.interfaces_field = interfaces; 2650 } 2651 } 2652 } 2653 return t.interfaces_field; 2654 } 2655 2656 @Override 2657 public List<Type> visitTypeVar(TypeVar t, Void ignored) { 2658 if (t.getUpperBound().isCompound()) 2659 return interfaces(t.getUpperBound()); 2660 2661 if (t.getUpperBound().isInterface()) 2662 return List.of(t.getUpperBound()); 2663 2664 return List.nil(); 2665 } 2666 }; 2667 2668 public List<Type> directSupertypes(Type t) { 2669 return directSupertypes.visit(t); 2670 } 2671 // where 2672 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() { 2673 2674 public List<Type> visitType(final Type type, final Void ignored) { 2675 if (!type.isIntersection()) { 2676 final Type sup = supertype(type); 2677 return (sup == Type.noType || sup == type || sup == null) 2678 ? interfaces(type) 2679 : interfaces(type).prepend(sup); 2680 } else { 2681 return ((IntersectionClassType)type).getExplicitComponents(); 2682 } 2683 } 2684 }; 2685 2686 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) { 2687 for (Type i2 : interfaces(origin.type)) { 2688 if (isym == i2.tsym) return true; 2689 } 2690 return false; 2691 } 2692 // </editor-fold> 2693 2694 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw"> 2695 Map<Type,Boolean> isDerivedRawCache = new HashMap<>(); 2696 2697 public boolean isDerivedRaw(Type t) { 2698 Boolean result = isDerivedRawCache.get(t); 2699 if (result == null) { 2700 result = isDerivedRawInternal(t); 2701 isDerivedRawCache.put(t, result); 2702 } 2703 return result; 2704 } 2705 2706 public boolean isDerivedRawInternal(Type t) { 2707 if (t.isErroneous()) 2708 return false; 2709 return 2710 t.isRaw() || 2711 supertype(t) != Type.noType && isDerivedRaw(supertype(t)) || 2712 isDerivedRaw(interfaces(t)); 2713 } 2714 2715 public boolean isDerivedRaw(List<Type> ts) { 2716 List<Type> l = ts; 2717 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail; 2718 return l.nonEmpty(); 2719 } 2720 // </editor-fold> 2721 2722 // <editor-fold defaultstate="collapsed" desc="setBounds"> 2723 /** 2724 * Same as {@link Types#setBounds(TypeVar, List, boolean)}, except that third parameter is computed directly, 2725 * as follows: if all all bounds are interface types, the computed supertype is Object,otherwise 2726 * the supertype is simply left null (in this case, the supertype is assumed to be the head of 2727 * the bound list passed as second argument). Note that this check might cause a symbol completion. 2728 * Hence, this version of setBounds may not be called during a classfile read. 2729 * 2730 * @param t a type variable 2731 * @param bounds the bounds, must be nonempty 2732 */ 2733 public void setBounds(TypeVar t, List<Type> bounds) { 2734 setBounds(t, bounds, bounds.head.tsym.isInterface()); 2735 } 2736 2737 /** 2738 * Set the bounds field of the given type variable to reflect a (possibly multiple) list of bounds. 2739 * This does not cause symbol completion as an extra parameter indicates as to whether all bounds 2740 * are interfaces - in which case the supertype is implicitly assumed to be 'Object'. 2741 * 2742 * @param t a type variable 2743 * @param bounds the bounds, must be nonempty 2744 * @param allInterfaces are all bounds interface types? 2745 */ 2746 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) { 2747 t.setUpperBound( bounds.tail.isEmpty() ? 2748 bounds.head : 2749 makeIntersectionType(bounds, allInterfaces) ); 2750 t.rank_field = -1; 2751 } 2752 // </editor-fold> 2753 2754 // <editor-fold defaultstate="collapsed" desc="getBounds"> 2755 /** 2756 * Return list of bounds of the given type variable. 2757 */ 2758 public List<Type> getBounds(TypeVar t) { 2759 if (t.getUpperBound().hasTag(NONE)) 2760 return List.nil(); 2761 else if (t.getUpperBound().isErroneous() || !t.getUpperBound().isCompound()) 2762 return List.of(t.getUpperBound()); 2763 else if ((erasure(t).tsym.flags() & INTERFACE) == 0) 2764 return interfaces(t).prepend(supertype(t)); 2765 else 2766 // No superclass was given in bounds. 2767 // In this case, supertype is Object, erasure is first interface. 2768 return interfaces(t); 2769 } 2770 // </editor-fold> 2771 2772 // <editor-fold defaultstate="collapsed" desc="classBound"> 2773 /** 2774 * If the given type is a (possibly selected) type variable, 2775 * return the bounding class of this type, otherwise return the 2776 * type itself. 2777 */ 2778 public Type classBound(Type t) { 2779 return classBound.visit(t); 2780 } 2781 // where 2782 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() { 2783 2784 public Type visitType(Type t, Void ignored) { 2785 return t; 2786 } 2787 2788 @Override 2789 public Type visitClassType(ClassType t, Void ignored) { 2790 Type outer1 = classBound(t.getEnclosingType()); 2791 if (outer1 != t.getEnclosingType()) 2792 return new ClassType(outer1, t.getTypeArguments(), t.tsym, 2793 t.getMetadata()); 2794 else 2795 return t; 2796 } 2797 2798 @Override 2799 public Type visitTypeVar(TypeVar t, Void ignored) { 2800 return classBound(supertype(t)); 2801 } 2802 2803 @Override 2804 public Type visitErrorType(ErrorType t, Void ignored) { 2805 return t; 2806 } 2807 }; 2808 // </editor-fold> 2809 2810 // <editor-fold defaultstate="collapsed" desc="subsignature / override equivalence"> 2811 /** 2812 * Returns true iff the first signature is a <em>subsignature</em> 2813 * of the other. This is <b>not</b> an equivalence 2814 * relation. 2815 * 2816 * @jls 8.4.2 Method Signature 2817 * @see #overrideEquivalent(Type t, Type s) 2818 * @param t first signature (possibly raw). 2819 * @param s second signature (could be subjected to erasure). 2820 * @return true if t is a subsignature of s. 2821 */ 2822 public boolean isSubSignature(Type t, Type s) { 2823 return hasSameArgs(t, s, true) || hasSameArgs(t, erasure(s), true); 2824 } 2825 2826 /** 2827 * Returns true iff these signatures are related by <em>override 2828 * equivalence</em>. This is the natural extension of 2829 * isSubSignature to an equivalence relation. 2830 * 2831 * @jls 8.4.2 Method Signature 2832 * @see #isSubSignature(Type t, Type s) 2833 * @param t a signature (possible raw, could be subjected to 2834 * erasure). 2835 * @param s a signature (possible raw, could be subjected to 2836 * erasure). 2837 * @return true if either argument is a subsignature of the other. 2838 */ 2839 public boolean overrideEquivalent(Type t, Type s) { 2840 return hasSameArgs(t, s) || 2841 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s); 2842 } 2843 2844 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) { 2845 for (Symbol sym : syms.objectType.tsym.members().getSymbolsByName(msym.name)) { 2846 if (msym.overrides(sym, origin, Types.this, true)) { 2847 return true; 2848 } 2849 } 2850 return false; 2851 } 2852 2853 /** 2854 * This enum defines the strategy for implementing most specific return type check 2855 * during the most specific and functional interface checks. 2856 */ 2857 public enum MostSpecificReturnCheck { 2858 /** 2859 * Return r1 is more specific than r2 if {@code r1 <: r2}. Extra care required for (i) handling 2860 * method type variables (if either method is generic) and (ii) subtyping should be replaced 2861 * by type-equivalence for primitives. This is essentially an inlined version of 2862 * {@link Types#resultSubtype(Type, Type, Warner)}, where the assignability check has been 2863 * replaced with a strict subtyping check. 2864 */ 2865 BASIC() { 2866 @Override 2867 public boolean test(Type mt1, Type mt2, Types types) { 2868 List<Type> tvars = mt1.getTypeArguments(); 2869 List<Type> svars = mt2.getTypeArguments(); 2870 Type t = mt1.getReturnType(); 2871 Type s = types.subst(mt2.getReturnType(), svars, tvars); 2872 return types.isSameType(t, s) || 2873 !t.isPrimitive() && 2874 !s.isPrimitive() && 2875 types.isSubtype(t, s); 2876 } 2877 }, 2878 /** 2879 * Return r1 is more specific than r2 if r1 is return-type-substitutable for r2. 2880 */ 2881 RTS() { 2882 @Override 2883 public boolean test(Type mt1, Type mt2, Types types) { 2884 return types.returnTypeSubstitutable(mt1, mt2); 2885 } 2886 }; 2887 2888 public abstract boolean test(Type mt1, Type mt2, Types types); 2889 } 2890 2891 /** 2892 * Merge multiple abstract methods. The preferred method is a method that is a subsignature 2893 * of all the other signatures and whose return type is more specific {@link MostSpecificReturnCheck}. 2894 * The resulting preferred method has a throws clause that is the intersection of the merged 2895 * methods' clauses. 2896 */ 2897 public Optional<Symbol> mergeAbstracts(List<Symbol> ambiguousInOrder, Type site, boolean sigCheck) { 2898 //first check for preconditions 2899 boolean shouldErase = false; 2900 List<Type> erasedParams = ambiguousInOrder.head.erasure(this).getParameterTypes(); 2901 for (Symbol s : ambiguousInOrder) { 2902 if ((s.flags() & ABSTRACT) == 0 || 2903 (sigCheck && !isSameTypes(erasedParams, s.erasure(this).getParameterTypes()))) { 2904 return Optional.empty(); 2905 } else if (s.type.hasTag(FORALL)) { 2906 shouldErase = true; 2907 } 2908 } 2909 //then merge abstracts 2910 for (MostSpecificReturnCheck mostSpecificReturnCheck : MostSpecificReturnCheck.values()) { 2911 outer: for (Symbol s : ambiguousInOrder) { 2912 Type mt = memberType(site, s); 2913 List<Type> allThrown = mt.getThrownTypes(); 2914 for (Symbol s2 : ambiguousInOrder) { 2915 if (s != s2) { 2916 Type mt2 = memberType(site, s2); 2917 if (!isSubSignature(mt, mt2) || 2918 !mostSpecificReturnCheck.test(mt, mt2, this)) { 2919 //ambiguity cannot be resolved 2920 continue outer; 2921 } else { 2922 List<Type> thrownTypes2 = mt2.getThrownTypes(); 2923 if (!mt.hasTag(FORALL) && shouldErase) { 2924 thrownTypes2 = erasure(thrownTypes2); 2925 } else if (mt.hasTag(FORALL)) { 2926 //subsignature implies that if most specific is generic, then all other 2927 //methods are too 2928 Assert.check(mt2.hasTag(FORALL)); 2929 // if both are generic methods, adjust thrown types ahead of intersection computation 2930 thrownTypes2 = subst(thrownTypes2, mt2.getTypeArguments(), mt.getTypeArguments()); 2931 } 2932 allThrown = chk.intersect(allThrown, thrownTypes2); 2933 } 2934 } 2935 } 2936 return (allThrown == mt.getThrownTypes()) ? 2937 Optional.of(s) : 2938 Optional.of(new MethodSymbol( 2939 s.flags(), 2940 s.name, 2941 createMethodTypeWithThrown(s.type, allThrown), 2942 s.owner) { 2943 @Override 2944 public Symbol baseSymbol() { 2945 return s; 2946 } 2947 }); 2948 } 2949 } 2950 return Optional.empty(); 2951 } 2952 2953 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site"> 2954 class ImplementationCache { 2955 2956 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map = new WeakHashMap<>(); 2957 2958 class Entry { 2959 final MethodSymbol cachedImpl; 2960 final Predicate<Symbol> implFilter; 2961 final boolean checkResult; 2962 final int prevMark; 2963 2964 public Entry(MethodSymbol cachedImpl, 2965 Predicate<Symbol> scopeFilter, 2966 boolean checkResult, 2967 int prevMark) { 2968 this.cachedImpl = cachedImpl; 2969 this.implFilter = scopeFilter; 2970 this.checkResult = checkResult; 2971 this.prevMark = prevMark; 2972 } 2973 2974 boolean matches(Predicate<Symbol> scopeFilter, boolean checkResult, int mark) { 2975 return this.implFilter == scopeFilter && 2976 this.checkResult == checkResult && 2977 this.prevMark == mark; 2978 } 2979 } 2980 2981 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) { 2982 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms); 2983 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null; 2984 if (cache == null) { 2985 cache = new HashMap<>(); 2986 _map.put(ms, new SoftReference<>(cache)); 2987 } 2988 Entry e = cache.get(origin); 2989 CompoundScope members = membersClosure(origin.type, true); 2990 if (e == null || 2991 !e.matches(implFilter, checkResult, members.getMark())) { 2992 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter); 2993 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark())); 2994 return impl; 2995 } 2996 else { 2997 return e.cachedImpl; 2998 } 2999 } 3000 3001 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) { 3002 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) { 3003 t = skipTypeVars(t, false); 3004 TypeSymbol c = t.tsym; 3005 Symbol bestSoFar = null; 3006 for (Symbol sym : c.members().getSymbolsByName(ms.name, implFilter)) { 3007 if (sym != null && sym.overrides(ms, origin, Types.this, checkResult)) { 3008 bestSoFar = sym; 3009 if ((sym.flags() & ABSTRACT) == 0) { 3010 //if concrete impl is found, exit immediately 3011 break; 3012 } 3013 } 3014 } 3015 if (bestSoFar != null) { 3016 //return either the (only) concrete implementation or the first abstract one 3017 return (MethodSymbol)bestSoFar; 3018 } 3019 } 3020 return null; 3021 } 3022 } 3023 3024 private ImplementationCache implCache = new ImplementationCache(); 3025 3026 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) { 3027 return implCache.get(ms, origin, checkResult, implFilter); 3028 } 3029 // </editor-fold> 3030 3031 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site"> 3032 class MembersClosureCache extends SimpleVisitor<Scope.CompoundScope, Void> { 3033 3034 private Map<TypeSymbol, CompoundScope> _map = new HashMap<>(); 3035 3036 Set<TypeSymbol> seenTypes = new HashSet<>(); 3037 3038 class MembersScope extends CompoundScope { 3039 3040 CompoundScope scope; 3041 3042 public MembersScope(CompoundScope scope) { 3043 super(scope.owner); 3044 this.scope = scope; 3045 } 3046 3047 Predicate<Symbol> combine(Predicate<Symbol> sf) { 3048 return s -> !s.owner.isInterface() && (sf == null || sf.test(s)); 3049 } 3050 3051 @Override 3052 public Iterable<Symbol> getSymbols(Predicate<Symbol> sf, LookupKind lookupKind) { 3053 return scope.getSymbols(combine(sf), lookupKind); 3054 } 3055 3056 @Override 3057 public Iterable<Symbol> getSymbolsByName(Name name, Predicate<Symbol> sf, LookupKind lookupKind) { 3058 return scope.getSymbolsByName(name, combine(sf), lookupKind); 3059 } 3060 3061 @Override 3062 public int getMark() { 3063 return scope.getMark(); 3064 } 3065 } 3066 3067 CompoundScope nilScope; 3068 3069 /** members closure visitor methods **/ 3070 3071 public CompoundScope visitType(Type t, Void _unused) { 3072 if (nilScope == null) { 3073 nilScope = new CompoundScope(syms.noSymbol); 3074 } 3075 return nilScope; 3076 } 3077 3078 @Override 3079 public CompoundScope visitClassType(ClassType t, Void _unused) { 3080 if (!seenTypes.add(t.tsym)) { 3081 //this is possible when an interface is implemented in multiple 3082 //superclasses, or when a class hierarchy is circular - in such 3083 //cases we don't need to recurse (empty scope is returned) 3084 return new CompoundScope(t.tsym); 3085 } 3086 try { 3087 seenTypes.add(t.tsym); 3088 ClassSymbol csym = (ClassSymbol)t.tsym; 3089 CompoundScope membersClosure = _map.get(csym); 3090 if (membersClosure == null) { 3091 membersClosure = new CompoundScope(csym); 3092 for (Type i : interfaces(t)) { 3093 membersClosure.prependSubScope(visit(i, null)); 3094 } 3095 membersClosure.prependSubScope(visit(supertype(t), null)); 3096 membersClosure.prependSubScope(csym.members()); 3097 _map.put(csym, membersClosure); 3098 } 3099 return membersClosure; 3100 } 3101 finally { 3102 seenTypes.remove(t.tsym); 3103 } 3104 } 3105 3106 @Override 3107 public CompoundScope visitTypeVar(TypeVar t, Void _unused) { 3108 return visit(t.getUpperBound(), null); 3109 } 3110 } 3111 3112 private MembersClosureCache membersCache = new MembersClosureCache(); 3113 3114 public CompoundScope membersClosure(Type site, boolean skipInterface) { 3115 CompoundScope cs = membersCache.visit(site, null); 3116 Assert.checkNonNull(cs, () -> "type " + site); 3117 return skipInterface ? membersCache.new MembersScope(cs) : cs; 3118 } 3119 // </editor-fold> 3120 3121 3122 /** Return first abstract member of class `sym'. 3123 */ 3124 public MethodSymbol firstUnimplementedAbstract(ClassSymbol sym) { 3125 try { 3126 return firstUnimplementedAbstractImpl(sym, sym); 3127 } catch (CompletionFailure ex) { 3128 chk.completionError(enter.getEnv(sym).tree.pos(), ex); 3129 return null; 3130 } 3131 } 3132 //where: 3133 private MethodSymbol firstUnimplementedAbstractImpl(ClassSymbol impl, ClassSymbol c) { 3134 MethodSymbol undef = null; 3135 // Do not bother to search in classes that are not abstract, 3136 // since they cannot have abstract members. 3137 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) { 3138 Scope s = c.members(); 3139 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) { 3140 if (sym.kind == MTH && 3141 (sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) { 3142 MethodSymbol absmeth = (MethodSymbol)sym; 3143 MethodSymbol implmeth = absmeth.implementation(impl, this, true); 3144 if (implmeth == null || implmeth == absmeth) { 3145 //look for default implementations 3146 MethodSymbol prov = interfaceCandidates(impl.type, absmeth).head; 3147 if (prov != null && prov.overrides(absmeth, impl, this, true)) { 3148 implmeth = prov; 3149 } 3150 } 3151 if (implmeth == null || implmeth == absmeth) { 3152 undef = absmeth; 3153 break; 3154 } 3155 } 3156 } 3157 if (undef == null) { 3158 Type st = supertype(c.type); 3159 if (st.hasTag(CLASS)) 3160 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)st.tsym); 3161 } 3162 for (List<Type> l = interfaces(c.type); 3163 undef == null && l.nonEmpty(); 3164 l = l.tail) { 3165 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)l.head.tsym); 3166 } 3167 } 3168 return undef; 3169 } 3170 3171 public class CandidatesCache { 3172 public Map<Entry, List<MethodSymbol>> cache = new WeakHashMap<>(); 3173 3174 class Entry { 3175 Type site; 3176 MethodSymbol msym; 3177 3178 Entry(Type site, MethodSymbol msym) { 3179 this.site = site; 3180 this.msym = msym; 3181 } 3182 3183 @Override 3184 public boolean equals(Object obj) { 3185 return (obj instanceof Entry entry) 3186 && entry.msym == msym 3187 && isSameType(site, entry.site); 3188 } 3189 3190 @Override 3191 public int hashCode() { 3192 return Types.this.hashCode(site) & ~msym.hashCode(); 3193 } 3194 } 3195 3196 public List<MethodSymbol> get(Entry e) { 3197 return cache.get(e); 3198 } 3199 3200 public void put(Entry e, List<MethodSymbol> msymbols) { 3201 cache.put(e, msymbols); 3202 } 3203 } 3204 3205 public CandidatesCache candidatesCache = new CandidatesCache(); 3206 3207 //where 3208 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) { 3209 CandidatesCache.Entry e = candidatesCache.new Entry(site, ms); 3210 List<MethodSymbol> candidates = candidatesCache.get(e); 3211 if (candidates == null) { 3212 Predicate<Symbol> filter = new MethodFilter(ms, site); 3213 List<MethodSymbol> candidates2 = List.nil(); 3214 for (Symbol s : membersClosure(site, false).getSymbols(filter)) { 3215 if (!site.tsym.isInterface() && !s.owner.isInterface()) { 3216 return List.of((MethodSymbol)s); 3217 } else if (!candidates2.contains(s)) { 3218 candidates2 = candidates2.prepend((MethodSymbol)s); 3219 } 3220 } 3221 candidates = prune(candidates2); 3222 candidatesCache.put(e, candidates); 3223 } 3224 return candidates; 3225 } 3226 3227 public List<MethodSymbol> prune(List<MethodSymbol> methods) { 3228 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>(); 3229 for (MethodSymbol m1 : methods) { 3230 boolean isMin_m1 = true; 3231 for (MethodSymbol m2 : methods) { 3232 if (m1 == m2) continue; 3233 if (m2.owner != m1.owner && 3234 asSuper(m2.owner.type, m1.owner) != null) { 3235 isMin_m1 = false; 3236 break; 3237 } 3238 } 3239 if (isMin_m1) 3240 methodsMin.append(m1); 3241 } 3242 return methodsMin.toList(); 3243 } 3244 // where 3245 private class MethodFilter implements Predicate<Symbol> { 3246 3247 Symbol msym; 3248 Type site; 3249 3250 MethodFilter(Symbol msym, Type site) { 3251 this.msym = msym; 3252 this.site = site; 3253 } 3254 3255 @Override 3256 public boolean test(Symbol s) { 3257 return s.kind == MTH && 3258 s.name == msym.name && 3259 (s.flags() & SYNTHETIC) == 0 && 3260 s.isInheritedIn(site.tsym, Types.this) && 3261 overrideEquivalent(memberType(site, s), memberType(site, msym)); 3262 } 3263 } 3264 // </editor-fold> 3265 3266 /** 3267 * Does t have the same arguments as s? It is assumed that both 3268 * types are (possibly polymorphic) method types. Monomorphic 3269 * method types "have the same arguments", if their argument lists 3270 * are equal. Polymorphic method types "have the same arguments", 3271 * if they have the same arguments after renaming all type 3272 * variables of one to corresponding type variables in the other, 3273 * where correspondence is by position in the type parameter list. 3274 */ 3275 public boolean hasSameArgs(Type t, Type s) { 3276 return hasSameArgs(t, s, true); 3277 } 3278 3279 public boolean hasSameArgs(Type t, Type s, boolean strict) { 3280 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict); 3281 } 3282 3283 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) { 3284 return hasSameArgs.visit(t, s); 3285 } 3286 // where 3287 private class HasSameArgs extends TypeRelation { 3288 3289 boolean strict; 3290 3291 public HasSameArgs(boolean strict) { 3292 this.strict = strict; 3293 } 3294 3295 public Boolean visitType(Type t, Type s) { 3296 throw new AssertionError(); 3297 } 3298 3299 @Override 3300 public Boolean visitMethodType(MethodType t, Type s) { 3301 return s.hasTag(METHOD) 3302 && containsTypeEquivalent(t.argtypes, s.getParameterTypes()); 3303 } 3304 3305 @Override 3306 public Boolean visitForAll(ForAll t, Type s) { 3307 if (!s.hasTag(FORALL)) 3308 return strict ? false : visitMethodType(t.asMethodType(), s); 3309 3310 ForAll forAll = (ForAll)s; 3311 return hasSameBounds(t, forAll) 3312 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); 3313 } 3314 3315 @Override 3316 public Boolean visitErrorType(ErrorType t, Type s) { 3317 return false; 3318 } 3319 } 3320 3321 TypeRelation hasSameArgs_strict = new HasSameArgs(true); 3322 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false); 3323 3324 // </editor-fold> 3325 3326 // <editor-fold defaultstate="collapsed" desc="subst"> 3327 public List<Type> subst(List<Type> ts, 3328 List<Type> from, 3329 List<Type> to) { 3330 return ts.map(new Subst(from, to)); 3331 } 3332 3333 /** 3334 * Substitute all occurrences of a type in `from' with the 3335 * corresponding type in `to' in 't'. Match lists `from' and `to' 3336 * from the right: If lists have different length, discard leading 3337 * elements of the longer list. 3338 */ 3339 public Type subst(Type t, List<Type> from, List<Type> to) { 3340 return t.map(new Subst(from, to)); 3341 } 3342 3343 /* this class won't substitute all types for example UndetVars are never substituted, this is 3344 * by design as UndetVars are used locally during inference and shouldn't escape from inference routines, 3345 * some specialized applications could need a tailored solution 3346 */ 3347 private class Subst extends StructuralTypeMapping<Void> { 3348 List<Type> from; 3349 List<Type> to; 3350 3351 public Subst(List<Type> from, List<Type> to) { 3352 int fromLength = from.length(); 3353 int toLength = to.length(); 3354 while (fromLength > toLength) { 3355 fromLength--; 3356 from = from.tail; 3357 } 3358 while (fromLength < toLength) { 3359 toLength--; 3360 to = to.tail; 3361 } 3362 this.from = from; 3363 this.to = to; 3364 } 3365 3366 @Override 3367 public Type visitTypeVar(TypeVar t, Void ignored) { 3368 for (List<Type> from = this.from, to = this.to; 3369 from.nonEmpty(); 3370 from = from.tail, to = to.tail) { 3371 if (t.equalsIgnoreMetadata(from.head)) { 3372 return to.head.withTypeVar(t); 3373 } 3374 } 3375 return t; 3376 } 3377 3378 @Override 3379 public Type visitClassType(ClassType t, Void ignored) { 3380 if (!t.isCompound()) { 3381 return super.visitClassType(t, ignored); 3382 } else { 3383 Type st = visit(supertype(t)); 3384 List<Type> is = visit(interfaces(t), ignored); 3385 if (st == supertype(t) && is == interfaces(t)) 3386 return t; 3387 else 3388 return makeIntersectionType(is.prepend(st)); 3389 } 3390 } 3391 3392 @Override 3393 public Type visitWildcardType(WildcardType t, Void ignored) { 3394 WildcardType t2 = (WildcardType)super.visitWildcardType(t, ignored); 3395 if (t2 != t && t.isExtendsBound() && t2.type.isExtendsBound()) { 3396 t2.type = wildUpperBound(t2.type); 3397 } 3398 return t2; 3399 } 3400 3401 @Override 3402 public Type visitForAll(ForAll t, Void ignored) { 3403 if (Type.containsAny(to, t.tvars)) { 3404 //perform alpha-renaming of free-variables in 't' 3405 //if 'to' types contain variables that are free in 't' 3406 List<Type> freevars = newInstances(t.tvars); 3407 t = new ForAll(freevars, 3408 Types.this.subst(t.qtype, t.tvars, freevars)); 3409 } 3410 List<Type> tvars1 = substBounds(t.tvars, from, to); 3411 Type qtype1 = visit(t.qtype); 3412 if (tvars1 == t.tvars && qtype1 == t.qtype) { 3413 return t; 3414 } else if (tvars1 == t.tvars) { 3415 return new ForAll(tvars1, qtype1) { 3416 @Override 3417 public boolean needsStripping() { 3418 return true; 3419 } 3420 }; 3421 } else { 3422 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1)) { 3423 @Override 3424 public boolean needsStripping() { 3425 return true; 3426 } 3427 }; 3428 } 3429 } 3430 } 3431 3432 public List<Type> substBounds(List<Type> tvars, 3433 List<Type> from, 3434 List<Type> to) { 3435 if (tvars.isEmpty()) 3436 return tvars; 3437 ListBuffer<Type> newBoundsBuf = new ListBuffer<>(); 3438 boolean changed = false; 3439 // calculate new bounds 3440 for (Type t : tvars) { 3441 TypeVar tv = (TypeVar) t; 3442 Type bound = subst(tv.getUpperBound(), from, to); 3443 if (bound != tv.getUpperBound()) 3444 changed = true; 3445 newBoundsBuf.append(bound); 3446 } 3447 if (!changed) 3448 return tvars; 3449 ListBuffer<Type> newTvars = new ListBuffer<>(); 3450 // create new type variables without bounds 3451 for (Type t : tvars) { 3452 newTvars.append(new TypeVar(t.tsym, null, syms.botType, 3453 t.getMetadata())); 3454 } 3455 // the new bounds should use the new type variables in place 3456 // of the old 3457 List<Type> newBounds = newBoundsBuf.toList(); 3458 from = tvars; 3459 to = newTvars.toList(); 3460 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) { 3461 newBounds.head = subst(newBounds.head, from, to); 3462 } 3463 newBounds = newBoundsBuf.toList(); 3464 // set the bounds of new type variables to the new bounds 3465 for (Type t : newTvars.toList()) { 3466 TypeVar tv = (TypeVar) t; 3467 tv.setUpperBound( newBounds.head ); 3468 newBounds = newBounds.tail; 3469 } 3470 return newTvars.toList(); 3471 } 3472 3473 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) { 3474 Type bound1 = subst(t.getUpperBound(), from, to); 3475 if (bound1 == t.getUpperBound()) 3476 return t; 3477 else { 3478 // create new type variable without bounds 3479 TypeVar tv = new TypeVar(t.tsym, null, syms.botType, 3480 t.getMetadata()); 3481 // the new bound should use the new type variable in place 3482 // of the old 3483 tv.setUpperBound( subst(bound1, List.of(t), List.of(tv)) ); 3484 return tv; 3485 } 3486 } 3487 // </editor-fold> 3488 3489 // <editor-fold defaultstate="collapsed" desc="hasSameBounds"> 3490 /** 3491 * Does t have the same bounds for quantified variables as s? 3492 */ 3493 public boolean hasSameBounds(ForAll t, ForAll s) { 3494 List<Type> l1 = t.tvars; 3495 List<Type> l2 = s.tvars; 3496 while (l1.nonEmpty() && l2.nonEmpty() && 3497 isSameType(l1.head.getUpperBound(), 3498 subst(l2.head.getUpperBound(), 3499 s.tvars, 3500 t.tvars))) { 3501 l1 = l1.tail; 3502 l2 = l2.tail; 3503 } 3504 return l1.isEmpty() && l2.isEmpty(); 3505 } 3506 // </editor-fold> 3507 3508 // <editor-fold defaultstate="collapsed" desc="newInstances"> 3509 /** Create new vector of type variables from list of variables 3510 * changing all recursive bounds from old to new list. 3511 */ 3512 public List<Type> newInstances(List<Type> tvars) { 3513 List<Type> tvars1 = tvars.map(newInstanceFun); 3514 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) { 3515 TypeVar tv = (TypeVar) l.head; 3516 tv.setUpperBound( subst(tv.getUpperBound(), tvars, tvars1) ); 3517 } 3518 return tvars1; 3519 } 3520 private static final TypeMapping<Void> newInstanceFun = new TypeMapping<Void>() { 3521 @Override 3522 public TypeVar visitTypeVar(TypeVar t, Void _unused) { 3523 return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound(), t.getMetadata()); 3524 } 3525 }; 3526 // </editor-fold> 3527 3528 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) { 3529 return original.accept(methodWithParameters, newParams); 3530 } 3531 // where 3532 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() { 3533 public Type visitType(Type t, List<Type> newParams) { 3534 throw new IllegalArgumentException("Not a method type: " + t); 3535 } 3536 public Type visitMethodType(MethodType t, List<Type> newParams) { 3537 return new MethodType(newParams, t.restype, t.thrown, t.tsym); 3538 } 3539 public Type visitForAll(ForAll t, List<Type> newParams) { 3540 return new ForAll(t.tvars, t.qtype.accept(this, newParams)); 3541 } 3542 }; 3543 3544 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) { 3545 return original.accept(methodWithThrown, newThrown); 3546 } 3547 // where 3548 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() { 3549 public Type visitType(Type t, List<Type> newThrown) { 3550 throw new IllegalArgumentException("Not a method type: " + t); 3551 } 3552 public Type visitMethodType(MethodType t, List<Type> newThrown) { 3553 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym); 3554 } 3555 public Type visitForAll(ForAll t, List<Type> newThrown) { 3556 return new ForAll(t.tvars, t.qtype.accept(this, newThrown)); 3557 } 3558 }; 3559 3560 public Type createMethodTypeWithReturn(Type original, Type newReturn) { 3561 return original.accept(methodWithReturn, newReturn); 3562 } 3563 // where 3564 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() { 3565 public Type visitType(Type t, Type newReturn) { 3566 throw new IllegalArgumentException("Not a method type: " + t); 3567 } 3568 public Type visitMethodType(MethodType t, Type newReturn) { 3569 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym) { 3570 @Override 3571 public Type baseType() { 3572 return t; 3573 } 3574 }; 3575 } 3576 public Type visitForAll(ForAll t, Type newReturn) { 3577 return new ForAll(t.tvars, t.qtype.accept(this, newReturn)) { 3578 @Override 3579 public Type baseType() { 3580 return t; 3581 } 3582 }; 3583 } 3584 }; 3585 3586 // <editor-fold defaultstate="collapsed" desc="createErrorType"> 3587 public Type createErrorType(Type originalType) { 3588 return new ErrorType(originalType, syms.errSymbol); 3589 } 3590 3591 public Type createErrorType(ClassSymbol c, Type originalType) { 3592 return new ErrorType(c, originalType); 3593 } 3594 3595 public Type createErrorType(Name name, TypeSymbol container, Type originalType) { 3596 return new ErrorType(name, container, originalType); 3597 } 3598 // </editor-fold> 3599 3600 // <editor-fold defaultstate="collapsed" desc="rank"> 3601 /** 3602 * The rank of a class is the length of the longest path between 3603 * the class and java.lang.Object in the class inheritance 3604 * graph. Undefined for all but reference types. 3605 */ 3606 public int rank(Type t) { 3607 switch(t.getTag()) { 3608 case CLASS: { 3609 ClassType cls = (ClassType)t; 3610 if (cls.rank_field < 0) { 3611 Name fullname = cls.tsym.getQualifiedName(); 3612 if (fullname == names.java_lang_Object) 3613 cls.rank_field = 0; 3614 else { 3615 int r = rank(supertype(cls)); 3616 for (List<Type> l = interfaces(cls); 3617 l.nonEmpty(); 3618 l = l.tail) { 3619 if (rank(l.head) > r) 3620 r = rank(l.head); 3621 } 3622 cls.rank_field = r + 1; 3623 } 3624 } 3625 return cls.rank_field; 3626 } 3627 case TYPEVAR: { 3628 TypeVar tvar = (TypeVar)t; 3629 if (tvar.rank_field < 0) { 3630 int r = rank(supertype(tvar)); 3631 for (List<Type> l = interfaces(tvar); 3632 l.nonEmpty(); 3633 l = l.tail) { 3634 if (rank(l.head) > r) r = rank(l.head); 3635 } 3636 tvar.rank_field = r + 1; 3637 } 3638 return tvar.rank_field; 3639 } 3640 case ERROR: 3641 case NONE: 3642 return 0; 3643 default: 3644 throw new AssertionError(); 3645 } 3646 } 3647 // </editor-fold> 3648 3649 /** 3650 * Helper method for generating a string representation of a given type 3651 * accordingly to a given locale 3652 */ 3653 public String toString(Type t, Locale locale) { 3654 return Printer.createStandardPrinter(messages).visit(t, locale); 3655 } 3656 3657 /** 3658 * Helper method for generating a string representation of a given type 3659 * accordingly to a given locale 3660 */ 3661 public String toString(Symbol t, Locale locale) { 3662 return Printer.createStandardPrinter(messages).visit(t, locale); 3663 } 3664 3665 // <editor-fold defaultstate="collapsed" desc="toString"> 3666 /** 3667 * This toString is slightly more descriptive than the one on Type. 3668 * 3669 * @deprecated Types.toString(Type t, Locale l) provides better support 3670 * for localization 3671 */ 3672 @Deprecated 3673 public String toString(Type t) { 3674 if (t.hasTag(FORALL)) { 3675 ForAll forAll = (ForAll)t; 3676 return typaramsString(forAll.tvars) + forAll.qtype; 3677 } 3678 return "" + t; 3679 } 3680 // where 3681 private String typaramsString(List<Type> tvars) { 3682 StringBuilder s = new StringBuilder(); 3683 s.append('<'); 3684 boolean first = true; 3685 for (Type t : tvars) { 3686 if (!first) s.append(", "); 3687 first = false; 3688 appendTyparamString(((TypeVar)t), s); 3689 } 3690 s.append('>'); 3691 return s.toString(); 3692 } 3693 private void appendTyparamString(TypeVar t, StringBuilder buf) { 3694 buf.append(t); 3695 if (t.getUpperBound() == null || 3696 t.getUpperBound().tsym.getQualifiedName() == names.java_lang_Object) 3697 return; 3698 buf.append(" extends "); // Java syntax; no need for i18n 3699 Type bound = t.getUpperBound(); 3700 if (!bound.isCompound()) { 3701 buf.append(bound); 3702 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) { 3703 buf.append(supertype(t)); 3704 for (Type intf : interfaces(t)) { 3705 buf.append('&'); 3706 buf.append(intf); 3707 } 3708 } else { 3709 // No superclass was given in bounds. 3710 // In this case, supertype is Object, erasure is first interface. 3711 boolean first = true; 3712 for (Type intf : interfaces(t)) { 3713 if (!first) buf.append('&'); 3714 first = false; 3715 buf.append(intf); 3716 } 3717 } 3718 } 3719 // </editor-fold> 3720 3721 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types"> 3722 /** 3723 * A cache for closures. 3724 * 3725 * <p>A closure is a list of all the supertypes and interfaces of 3726 * a class or interface type, ordered by ClassSymbol.precedes 3727 * (that is, subclasses come first, arbitrarily but fixed 3728 * otherwise). 3729 */ 3730 private Map<Type,List<Type>> closureCache = new HashMap<>(); 3731 3732 /** 3733 * Returns the closure of a class or interface type. 3734 */ 3735 public List<Type> closure(Type t) { 3736 List<Type> cl = closureCache.get(t); 3737 if (cl == null) { 3738 Type st = supertype(t); 3739 if (!t.isCompound()) { 3740 if (st.hasTag(CLASS)) { 3741 cl = insert(closure(st), t); 3742 } else if (st.hasTag(TYPEVAR)) { 3743 cl = closure(st).prepend(t); 3744 } else { 3745 cl = List.of(t); 3746 } 3747 } else { 3748 cl = closure(supertype(t)); 3749 } 3750 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) 3751 cl = union(cl, closure(l.head)); 3752 closureCache.put(t, cl); 3753 } 3754 return cl; 3755 } 3756 3757 /** 3758 * Collect types into a new closure (using a {@code ClosureHolder}) 3759 */ 3760 public Collector<Type, ClosureHolder, List<Type>> closureCollector(boolean minClosure, BiPredicate<Type, Type> shouldSkip) { 3761 return Collector.of(() -> new ClosureHolder(minClosure, shouldSkip), 3762 ClosureHolder::add, 3763 ClosureHolder::merge, 3764 ClosureHolder::closure); 3765 } 3766 //where 3767 class ClosureHolder { 3768 List<Type> closure; 3769 final boolean minClosure; 3770 final BiPredicate<Type, Type> shouldSkip; 3771 3772 ClosureHolder(boolean minClosure, BiPredicate<Type, Type> shouldSkip) { 3773 this.closure = List.nil(); 3774 this.minClosure = minClosure; 3775 this.shouldSkip = shouldSkip; 3776 } 3777 3778 void add(Type type) { 3779 closure = insert(closure, type, shouldSkip); 3780 } 3781 3782 ClosureHolder merge(ClosureHolder other) { 3783 closure = union(closure, other.closure, shouldSkip); 3784 return this; 3785 } 3786 3787 List<Type> closure() { 3788 return minClosure ? closureMin(closure) : closure; 3789 } 3790 } 3791 3792 BiPredicate<Type, Type> basicClosureSkip = (t1, t2) -> t1.tsym == t2.tsym; 3793 3794 /** 3795 * Insert a type in a closure 3796 */ 3797 public List<Type> insert(List<Type> cl, Type t, BiPredicate<Type, Type> shouldSkip) { 3798 if (cl.isEmpty()) { 3799 return cl.prepend(t); 3800 } else if (shouldSkip.test(t, cl.head)) { 3801 return cl; 3802 } else if (t.tsym.precedes(cl.head.tsym, this)) { 3803 return cl.prepend(t); 3804 } else { 3805 // t comes after head, or the two are unrelated 3806 return insert(cl.tail, t, shouldSkip).prepend(cl.head); 3807 } 3808 } 3809 3810 public List<Type> insert(List<Type> cl, Type t) { 3811 return insert(cl, t, basicClosureSkip); 3812 } 3813 3814 /** 3815 * Form the union of two closures 3816 */ 3817 public List<Type> union(List<Type> cl1, List<Type> cl2, BiPredicate<Type, Type> shouldSkip) { 3818 if (cl1.isEmpty()) { 3819 return cl2; 3820 } else if (cl2.isEmpty()) { 3821 return cl1; 3822 } else if (shouldSkip.test(cl1.head, cl2.head)) { 3823 return union(cl1.tail, cl2.tail, shouldSkip).prepend(cl1.head); 3824 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) { 3825 return union(cl1, cl2.tail, shouldSkip).prepend(cl2.head); 3826 } else { 3827 return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head); 3828 } 3829 } 3830 3831 public List<Type> union(List<Type> cl1, List<Type> cl2) { 3832 return union(cl1, cl2, basicClosureSkip); 3833 } 3834 3835 /** 3836 * Intersect two closures 3837 */ 3838 public List<Type> intersect(List<Type> cl1, List<Type> cl2) { 3839 if (cl1 == cl2) 3840 return cl1; 3841 if (cl1.isEmpty() || cl2.isEmpty()) 3842 return List.nil(); 3843 if (cl1.head.tsym.precedes(cl2.head.tsym, this)) 3844 return intersect(cl1.tail, cl2); 3845 if (cl2.head.tsym.precedes(cl1.head.tsym, this)) 3846 return intersect(cl1, cl2.tail); 3847 if (isSameType(cl1.head, cl2.head)) 3848 return intersect(cl1.tail, cl2.tail).prepend(cl1.head); 3849 if (cl1.head.tsym == cl2.head.tsym && 3850 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) { 3851 if (cl1.head.isParameterized() && cl2.head.isParameterized()) { 3852 Type merge = merge(cl1.head,cl2.head); 3853 return intersect(cl1.tail, cl2.tail).prepend(merge); 3854 } 3855 if (cl1.head.isRaw() || cl2.head.isRaw()) 3856 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head)); 3857 } 3858 return intersect(cl1.tail, cl2.tail); 3859 } 3860 // where 3861 class TypePair { 3862 final Type t1; 3863 final Type t2;; 3864 3865 TypePair(Type t1, Type t2) { 3866 this.t1 = t1; 3867 this.t2 = t2; 3868 } 3869 @Override 3870 public int hashCode() { 3871 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2); 3872 } 3873 @Override 3874 public boolean equals(Object obj) { 3875 return (obj instanceof TypePair typePair) 3876 && isSameType(t1, typePair.t1) 3877 && isSameType(t2, typePair.t2); 3878 } 3879 } 3880 Set<TypePair> mergeCache = new HashSet<>(); 3881 private Type merge(Type c1, Type c2) { 3882 ClassType class1 = (ClassType) c1; 3883 List<Type> act1 = class1.getTypeArguments(); 3884 ClassType class2 = (ClassType) c2; 3885 List<Type> act2 = class2.getTypeArguments(); 3886 ListBuffer<Type> merged = new ListBuffer<>(); 3887 List<Type> typarams = class1.tsym.type.getTypeArguments(); 3888 3889 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) { 3890 if (containsType(act1.head, act2.head)) { 3891 merged.append(act1.head); 3892 } else if (containsType(act2.head, act1.head)) { 3893 merged.append(act2.head); 3894 } else { 3895 TypePair pair = new TypePair(c1, c2); 3896 Type m; 3897 if (mergeCache.add(pair)) { 3898 m = new WildcardType(lub(wildUpperBound(act1.head), 3899 wildUpperBound(act2.head)), 3900 BoundKind.EXTENDS, 3901 syms.boundClass); 3902 mergeCache.remove(pair); 3903 } else { 3904 m = new WildcardType(syms.objectType, 3905 BoundKind.UNBOUND, 3906 syms.boundClass); 3907 } 3908 merged.append(m.withTypeVar(typarams.head)); 3909 } 3910 act1 = act1.tail; 3911 act2 = act2.tail; 3912 typarams = typarams.tail; 3913 } 3914 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty()); 3915 // There is no spec detailing how type annotations are to 3916 // be inherited. So set it to noAnnotations for now 3917 return new ClassType(class1.getEnclosingType(), merged.toList(), 3918 class1.tsym); 3919 } 3920 3921 /** 3922 * Return the minimum type of a closure, a compound type if no 3923 * unique minimum exists. 3924 */ 3925 private Type compoundMin(List<Type> cl) { 3926 if (cl.isEmpty()) return syms.objectType; 3927 List<Type> compound = closureMin(cl); 3928 if (compound.isEmpty()) 3929 return null; 3930 else if (compound.tail.isEmpty()) 3931 return compound.head; 3932 else 3933 return makeIntersectionType(compound); 3934 } 3935 3936 /** 3937 * Return the minimum types of a closure, suitable for computing 3938 * compoundMin or glb. 3939 */ 3940 private List<Type> closureMin(List<Type> cl) { 3941 ListBuffer<Type> classes = new ListBuffer<>(); 3942 ListBuffer<Type> interfaces = new ListBuffer<>(); 3943 Set<Type> toSkip = new HashSet<>(); 3944 while (!cl.isEmpty()) { 3945 Type current = cl.head; 3946 boolean keep = !toSkip.contains(current); 3947 if (keep && current.hasTag(TYPEVAR)) { 3948 // skip lower-bounded variables with a subtype in cl.tail 3949 for (Type t : cl.tail) { 3950 if (isSubtypeNoCapture(t, current)) { 3951 keep = false; 3952 break; 3953 } 3954 } 3955 } 3956 if (keep) { 3957 if (current.isInterface()) 3958 interfaces.append(current); 3959 else 3960 classes.append(current); 3961 for (Type t : cl.tail) { 3962 // skip supertypes of 'current' in cl.tail 3963 if (isSubtypeNoCapture(current, t)) 3964 toSkip.add(t); 3965 } 3966 } 3967 cl = cl.tail; 3968 } 3969 return classes.appendList(interfaces).toList(); 3970 } 3971 3972 /** 3973 * Return the least upper bound of list of types. if the lub does 3974 * not exist return null. 3975 */ 3976 public Type lub(List<Type> ts) { 3977 return lub(ts.toArray(new Type[ts.length()])); 3978 } 3979 3980 /** 3981 * Return the least upper bound (lub) of set of types. If the lub 3982 * does not exist return the type of null (bottom). 3983 */ 3984 public Type lub(Type... ts) { 3985 final int UNKNOWN_BOUND = 0; 3986 final int ARRAY_BOUND = 1; 3987 final int CLASS_BOUND = 2; 3988 3989 int[] kinds = new int[ts.length]; 3990 3991 int boundkind = UNKNOWN_BOUND; 3992 for (int i = 0 ; i < ts.length ; i++) { 3993 Type t = ts[i]; 3994 switch (t.getTag()) { 3995 case CLASS: 3996 boundkind |= kinds[i] = CLASS_BOUND; 3997 break; 3998 case ARRAY: 3999 boundkind |= kinds[i] = ARRAY_BOUND; 4000 break; 4001 case TYPEVAR: 4002 do { 4003 t = t.getUpperBound(); 4004 } while (t.hasTag(TYPEVAR)); 4005 if (t.hasTag(ARRAY)) { 4006 boundkind |= kinds[i] = ARRAY_BOUND; 4007 } else { 4008 boundkind |= kinds[i] = CLASS_BOUND; 4009 } 4010 break; 4011 default: 4012 kinds[i] = UNKNOWN_BOUND; 4013 if (t.isPrimitive()) 4014 return syms.errType; 4015 } 4016 } 4017 switch (boundkind) { 4018 case 0: 4019 return syms.botType; 4020 4021 case ARRAY_BOUND: 4022 // calculate lub(A[], B[]) 4023 Type[] elements = new Type[ts.length]; 4024 for (int i = 0 ; i < ts.length ; i++) { 4025 Type elem = elements[i] = elemTypeFun.apply(ts[i]); 4026 if (elem.isPrimitive()) { 4027 // if a primitive type is found, then return 4028 // arraySuperType unless all the types are the 4029 // same 4030 Type first = ts[0]; 4031 for (int j = 1 ; j < ts.length ; j++) { 4032 if (!isSameType(first, ts[j])) { 4033 // lub(int[], B[]) is Cloneable & Serializable 4034 return arraySuperType(); 4035 } 4036 } 4037 // all the array types are the same, return one 4038 // lub(int[], int[]) is int[] 4039 return first; 4040 } 4041 } 4042 // lub(A[], B[]) is lub(A, B)[] 4043 return new ArrayType(lub(elements), syms.arrayClass); 4044 4045 case CLASS_BOUND: 4046 // calculate lub(A, B) 4047 int startIdx = 0; 4048 for (int i = 0; i < ts.length ; i++) { 4049 Type t = ts[i]; 4050 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) { 4051 break; 4052 } else { 4053 startIdx++; 4054 } 4055 } 4056 Assert.check(startIdx < ts.length); 4057 //step 1 - compute erased candidate set (EC) 4058 List<Type> cl = erasedSupertypes(ts[startIdx]); 4059 for (int i = startIdx + 1 ; i < ts.length ; i++) { 4060 Type t = ts[i]; 4061 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) 4062 cl = intersect(cl, erasedSupertypes(t)); 4063 } 4064 //step 2 - compute minimal erased candidate set (MEC) 4065 List<Type> mec = closureMin(cl); 4066 //step 3 - for each element G in MEC, compute lci(Inv(G)) 4067 List<Type> candidates = List.nil(); 4068 for (Type erasedSupertype : mec) { 4069 List<Type> lci = List.of(asSuper(ts[startIdx], erasedSupertype.tsym)); 4070 for (int i = startIdx + 1 ; i < ts.length ; i++) { 4071 Type superType = asSuper(ts[i], erasedSupertype.tsym); 4072 lci = intersect(lci, superType != null ? List.of(superType) : List.nil()); 4073 } 4074 candidates = candidates.appendList(lci); 4075 } 4076 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that 4077 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn)) 4078 return compoundMin(candidates); 4079 4080 default: 4081 // calculate lub(A, B[]) 4082 List<Type> classes = List.of(arraySuperType()); 4083 for (int i = 0 ; i < ts.length ; i++) { 4084 if (kinds[i] != ARRAY_BOUND) // Filter out any arrays 4085 classes = classes.prepend(ts[i]); 4086 } 4087 // lub(A, B[]) is lub(A, arraySuperType) 4088 return lub(classes); 4089 } 4090 } 4091 // where 4092 List<Type> erasedSupertypes(Type t) { 4093 ListBuffer<Type> buf = new ListBuffer<>(); 4094 for (Type sup : closure(t)) { 4095 if (sup.hasTag(TYPEVAR)) { 4096 buf.append(sup); 4097 } else { 4098 buf.append(erasure(sup)); 4099 } 4100 } 4101 return buf.toList(); 4102 } 4103 4104 private Type arraySuperType; 4105 private Type arraySuperType() { 4106 // initialized lazily to avoid problems during compiler startup 4107 if (arraySuperType == null) { 4108 // JLS 10.8: all arrays implement Cloneable and Serializable. 4109 arraySuperType = makeIntersectionType(List.of(syms.serializableType, 4110 syms.cloneableType), true); 4111 } 4112 return arraySuperType; 4113 } 4114 // </editor-fold> 4115 4116 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound"> 4117 public Type glb(List<Type> ts) { 4118 Type t1 = ts.head; 4119 for (Type t2 : ts.tail) { 4120 if (t1.isErroneous()) 4121 return t1; 4122 t1 = glb(t1, t2); 4123 } 4124 return t1; 4125 } 4126 //where 4127 public Type glb(Type t, Type s) { 4128 if (s == null) 4129 return t; 4130 else if (t.isPrimitive() || s.isPrimitive()) 4131 return syms.errType; 4132 else if (isSubtypeNoCapture(t, s)) 4133 return t; 4134 else if (isSubtypeNoCapture(s, t)) 4135 return s; 4136 4137 List<Type> closure = union(closure(t), closure(s)); 4138 return glbFlattened(closure, t); 4139 } 4140 //where 4141 /** 4142 * Perform glb for a list of non-primitive, non-error, non-compound types; 4143 * redundant elements are removed. Bounds should be ordered according to 4144 * {@link Symbol#precedes(TypeSymbol,Types)}. 4145 * 4146 * @param flatBounds List of type to glb 4147 * @param errT Original type to use if the result is an error type 4148 */ 4149 private Type glbFlattened(List<Type> flatBounds, Type errT) { 4150 List<Type> bounds = closureMin(flatBounds); 4151 4152 if (bounds.isEmpty()) { // length == 0 4153 return syms.objectType; 4154 } else if (bounds.tail.isEmpty()) { // length == 1 4155 return bounds.head; 4156 } else { // length > 1 4157 int classCount = 0; 4158 List<Type> cvars = List.nil(); 4159 List<Type> lowers = List.nil(); 4160 for (Type bound : bounds) { 4161 if (!bound.isInterface()) { 4162 classCount++; 4163 Type lower = cvarLowerBound(bound); 4164 if (bound != lower && !lower.hasTag(BOT)) { 4165 cvars = cvars.append(bound); 4166 lowers = lowers.append(lower); 4167 } 4168 } 4169 } 4170 if (classCount > 1) { 4171 if (lowers.isEmpty()) { 4172 return createErrorType(errT); 4173 } else { 4174 // try again with lower bounds included instead of capture variables 4175 List<Type> newBounds = bounds.diff(cvars).appendList(lowers); 4176 return glb(newBounds); 4177 } 4178 } 4179 } 4180 return makeIntersectionType(bounds); 4181 } 4182 // </editor-fold> 4183 4184 // <editor-fold defaultstate="collapsed" desc="hashCode"> 4185 /** 4186 * Compute a hash code on a type. 4187 */ 4188 public int hashCode(Type t) { 4189 return hashCode(t, false); 4190 } 4191 4192 public int hashCode(Type t, boolean strict) { 4193 return strict ? 4194 hashCodeStrictVisitor.visit(t) : 4195 hashCodeVisitor.visit(t); 4196 } 4197 // where 4198 private static final HashCodeVisitor hashCodeVisitor = new HashCodeVisitor(); 4199 private static final HashCodeVisitor hashCodeStrictVisitor = new HashCodeVisitor() { 4200 @Override 4201 public Integer visitTypeVar(TypeVar t, Void ignored) { 4202 return System.identityHashCode(t); 4203 } 4204 }; 4205 4206 private static class HashCodeVisitor extends UnaryVisitor<Integer> { 4207 public Integer visitType(Type t, Void ignored) { 4208 return t.getTag().ordinal(); 4209 } 4210 4211 @Override 4212 public Integer visitClassType(ClassType t, Void ignored) { 4213 int result = visit(t.getEnclosingType()); 4214 result *= 127; 4215 result += t.tsym.flatName().hashCode(); 4216 for (Type s : t.getTypeArguments()) { 4217 result *= 127; 4218 result += visit(s); 4219 } 4220 return result; 4221 } 4222 4223 @Override 4224 public Integer visitMethodType(MethodType t, Void ignored) { 4225 int h = METHOD.ordinal(); 4226 for (List<Type> thisargs = t.argtypes; 4227 thisargs.tail != null; 4228 thisargs = thisargs.tail) 4229 h = (h << 5) + visit(thisargs.head); 4230 return (h << 5) + visit(t.restype); 4231 } 4232 4233 @Override 4234 public Integer visitWildcardType(WildcardType t, Void ignored) { 4235 int result = t.kind.hashCode(); 4236 if (t.type != null) { 4237 result *= 127; 4238 result += visit(t.type); 4239 } 4240 return result; 4241 } 4242 4243 @Override 4244 public Integer visitArrayType(ArrayType t, Void ignored) { 4245 return visit(t.elemtype) + 12; 4246 } 4247 4248 @Override 4249 public Integer visitTypeVar(TypeVar t, Void ignored) { 4250 return System.identityHashCode(t); 4251 } 4252 4253 @Override 4254 public Integer visitUndetVar(UndetVar t, Void ignored) { 4255 return System.identityHashCode(t); 4256 } 4257 4258 @Override 4259 public Integer visitErrorType(ErrorType t, Void ignored) { 4260 return 0; 4261 } 4262 } 4263 // </editor-fold> 4264 4265 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable"> 4266 /** 4267 * Does t have a result that is a subtype of the result type of s, 4268 * suitable for covariant returns? It is assumed that both types 4269 * are (possibly polymorphic) method types. Monomorphic method 4270 * types are handled in the obvious way. Polymorphic method types 4271 * require renaming all type variables of one to corresponding 4272 * type variables in the other, where correspondence is by 4273 * position in the type parameter list. */ 4274 public boolean resultSubtype(Type t, Type s, Warner warner) { 4275 List<Type> tvars = t.getTypeArguments(); 4276 List<Type> svars = s.getTypeArguments(); 4277 Type tres = t.getReturnType(); 4278 Type sres = subst(s.getReturnType(), svars, tvars); 4279 return covariantReturnType(tres, sres, warner); 4280 } 4281 4282 /** 4283 * Return-Type-Substitutable. 4284 * @jls 8.4.5 Method Result 4285 */ 4286 public boolean returnTypeSubstitutable(Type r1, Type r2) { 4287 if (hasSameArgs(r1, r2)) 4288 return resultSubtype(r1, r2, noWarnings); 4289 else 4290 return covariantReturnType(r1.getReturnType(), 4291 erasure(r2.getReturnType()), 4292 noWarnings); 4293 } 4294 4295 public boolean returnTypeSubstitutable(Type r1, 4296 Type r2, Type r2res, 4297 Warner warner) { 4298 if (isSameType(r1.getReturnType(), r2res)) 4299 return true; 4300 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive()) 4301 return false; 4302 4303 if (hasSameArgs(r1, r2)) 4304 return covariantReturnType(r1.getReturnType(), r2res, warner); 4305 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner)) 4306 return true; 4307 if (!isSubtype(r1.getReturnType(), erasure(r2res))) 4308 return false; 4309 warner.warn(LintCategory.UNCHECKED); 4310 return true; 4311 } 4312 4313 /** 4314 * Is t an appropriate return type in an overrider for a 4315 * method that returns s? 4316 */ 4317 public boolean covariantReturnType(Type t, Type s, Warner warner) { 4318 return 4319 isSameType(t, s) || 4320 !t.isPrimitive() && 4321 !s.isPrimitive() && 4322 isAssignable(t, s, warner); 4323 } 4324 // </editor-fold> 4325 4326 // <editor-fold defaultstate="collapsed" desc="Box/unbox support"> 4327 /** 4328 * Return the class that boxes the given primitive. 4329 */ 4330 public ClassSymbol boxedClass(Type t) { 4331 return syms.enterClass(syms.java_base, syms.boxedName[t.getTag().ordinal()]); 4332 } 4333 4334 /** 4335 * Return the boxed type if 't' is primitive, otherwise return 't' itself. 4336 */ 4337 public Type boxedTypeOrType(Type t) { 4338 return t.isPrimitive() ? 4339 boxedClass(t).type : 4340 t; 4341 } 4342 4343 /** 4344 * Return the primitive type corresponding to a boxed type. 4345 */ 4346 public Type unboxedType(Type t) { 4347 if (t.hasTag(ERROR)) 4348 return Type.noType; 4349 for (int i=0; i<syms.boxedName.length; i++) { 4350 Name box = syms.boxedName[i]; 4351 if (box != null && 4352 asSuper(t, syms.enterClass(syms.java_base, box)) != null) 4353 return syms.typeOfTag[i]; 4354 } 4355 return Type.noType; 4356 } 4357 4358 /** 4359 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself. 4360 */ 4361 public Type unboxedTypeOrType(Type t) { 4362 Type unboxedType = unboxedType(t); 4363 return unboxedType.hasTag(NONE) ? t : unboxedType; 4364 } 4365 // </editor-fold> 4366 4367 // <editor-fold defaultstate="collapsed" desc="Capture conversion"> 4368 /* 4369 * JLS 5.1.10 Capture Conversion: 4370 * 4371 * Let G name a generic type declaration with n formal type 4372 * parameters A1 ... An with corresponding bounds U1 ... Un. There 4373 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>, 4374 * where, for 1 <= i <= n: 4375 * 4376 * + If Ti is a wildcard type argument (4.5.1) of the form ? then 4377 * Si is a fresh type variable whose upper bound is 4378 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null 4379 * type. 4380 * 4381 * + If Ti is a wildcard type argument of the form ? extends Bi, 4382 * then Si is a fresh type variable whose upper bound is 4383 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is 4384 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is 4385 * a compile-time error if for any two classes (not interfaces) 4386 * Vi and Vj,Vi is not a subclass of Vj or vice versa. 4387 * 4388 * + If Ti is a wildcard type argument of the form ? super Bi, 4389 * then Si is a fresh type variable whose upper bound is 4390 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi. 4391 * 4392 * + Otherwise, Si = Ti. 4393 * 4394 * Capture conversion on any type other than a parameterized type 4395 * (4.5) acts as an identity conversion (5.1.1). Capture 4396 * conversions never require a special action at run time and 4397 * therefore never throw an exception at run time. 4398 * 4399 * Capture conversion is not applied recursively. 4400 */ 4401 /** 4402 * Capture conversion as specified by the JLS. 4403 */ 4404 4405 public List<Type> capture(List<Type> ts) { 4406 List<Type> buf = List.nil(); 4407 for (Type t : ts) { 4408 buf = buf.prepend(capture(t)); 4409 } 4410 return buf.reverse(); 4411 } 4412 4413 public Type capture(Type t) { 4414 if (!t.hasTag(CLASS)) { 4415 return t; 4416 } 4417 if (t.getEnclosingType() != Type.noType) { 4418 Type capturedEncl = capture(t.getEnclosingType()); 4419 if (capturedEncl != t.getEnclosingType()) { 4420 Type type1 = memberType(capturedEncl, t.tsym); 4421 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments()); 4422 } 4423 } 4424 ClassType cls = (ClassType)t; 4425 if (cls.isRaw() || !cls.isParameterized()) 4426 return cls; 4427 4428 ClassType G = (ClassType)cls.asElement().asType(); 4429 List<Type> A = G.getTypeArguments(); 4430 List<Type> T = cls.getTypeArguments(); 4431 List<Type> S = freshTypeVariables(T); 4432 4433 List<Type> currentA = A; 4434 List<Type> currentT = T; 4435 List<Type> currentS = S; 4436 boolean captured = false; 4437 while (!currentA.isEmpty() && 4438 !currentT.isEmpty() && 4439 !currentS.isEmpty()) { 4440 if (currentS.head != currentT.head) { 4441 captured = true; 4442 WildcardType Ti = (WildcardType)currentT.head; 4443 Type Ui = currentA.head.getUpperBound(); 4444 CapturedType Si = (CapturedType)currentS.head; 4445 if (Ui == null) 4446 Ui = syms.objectType; 4447 switch (Ti.kind) { 4448 case UNBOUND: 4449 Si.setUpperBound( subst(Ui, A, S) ); 4450 Si.lower = syms.botType; 4451 break; 4452 case EXTENDS: 4453 Si.setUpperBound( glb(Ti.getExtendsBound(), subst(Ui, A, S)) ); 4454 Si.lower = syms.botType; 4455 break; 4456 case SUPER: 4457 Si.setUpperBound( subst(Ui, A, S) ); 4458 Si.lower = Ti.getSuperBound(); 4459 break; 4460 } 4461 Type tmpBound = Si.getUpperBound().hasTag(UNDETVAR) ? ((UndetVar)Si.getUpperBound()).qtype : Si.getUpperBound(); 4462 Type tmpLower = Si.lower.hasTag(UNDETVAR) ? ((UndetVar)Si.lower).qtype : Si.lower; 4463 if (!Si.getUpperBound().hasTag(ERROR) && 4464 !Si.lower.hasTag(ERROR) && 4465 isSameType(tmpBound, tmpLower)) { 4466 currentS.head = Si.getUpperBound(); 4467 } 4468 } 4469 currentA = currentA.tail; 4470 currentT = currentT.tail; 4471 currentS = currentS.tail; 4472 } 4473 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty()) 4474 return erasure(t); // some "rare" type involved 4475 4476 if (captured) 4477 return new ClassType(cls.getEnclosingType(), S, cls.tsym, 4478 cls.getMetadata()); 4479 else 4480 return t; 4481 } 4482 // where 4483 public List<Type> freshTypeVariables(List<Type> types) { 4484 ListBuffer<Type> result = new ListBuffer<>(); 4485 for (Type t : types) { 4486 if (t.hasTag(WILDCARD)) { 4487 Type bound = ((WildcardType)t).getExtendsBound(); 4488 if (bound == null) 4489 bound = syms.objectType; 4490 result.append(new CapturedType(capturedName, 4491 syms.noSymbol, 4492 bound, 4493 syms.botType, 4494 (WildcardType)t)); 4495 } else { 4496 result.append(t); 4497 } 4498 } 4499 return result.toList(); 4500 } 4501 // </editor-fold> 4502 4503 // <editor-fold defaultstate="collapsed" desc="Internal utility methods"> 4504 private boolean sideCast(Type from, Type to, Warner warn) { 4505 // We are casting from type $from$ to type $to$, which are 4506 // non-final unrelated types. This method 4507 // tries to reject a cast by transferring type parameters 4508 // from $to$ to $from$ by common superinterfaces. 4509 boolean reverse = false; 4510 Type target = to; 4511 if ((to.tsym.flags() & INTERFACE) == 0) { 4512 Assert.check((from.tsym.flags() & INTERFACE) != 0); 4513 reverse = true; 4514 to = from; 4515 from = target; 4516 } 4517 List<Type> commonSupers = superClosure(to, erasure(from)); 4518 boolean giveWarning = commonSupers.isEmpty(); 4519 // The arguments to the supers could be unified here to 4520 // get a more accurate analysis 4521 while (commonSupers.nonEmpty()) { 4522 Type t1 = asSuper(from, commonSupers.head.tsym); 4523 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym); 4524 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) 4525 return false; 4526 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)); 4527 commonSupers = commonSupers.tail; 4528 } 4529 if (giveWarning && !isReifiable(reverse ? from : to)) 4530 warn.warn(LintCategory.UNCHECKED); 4531 return true; 4532 } 4533 4534 private boolean sideCastFinal(Type from, Type to, Warner warn) { 4535 // We are casting from type $from$ to type $to$, which are 4536 // unrelated types one of which is final and the other of 4537 // which is an interface. This method 4538 // tries to reject a cast by transferring type parameters 4539 // from the final class to the interface. 4540 boolean reverse = false; 4541 Type target = to; 4542 if ((to.tsym.flags() & INTERFACE) == 0) { 4543 Assert.check((from.tsym.flags() & INTERFACE) != 0); 4544 reverse = true; 4545 to = from; 4546 from = target; 4547 } 4548 Assert.check((from.tsym.flags() & FINAL) != 0); 4549 Type t1 = asSuper(from, to.tsym); 4550 if (t1 == null) return false; 4551 Type t2 = to; 4552 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) 4553 return false; 4554 if (!isReifiable(target) && 4555 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2))) 4556 warn.warn(LintCategory.UNCHECKED); 4557 return true; 4558 } 4559 4560 private boolean giveWarning(Type from, Type to) { 4561 List<Type> bounds = to.isCompound() ? 4562 directSupertypes(to) : List.of(to); 4563 for (Type b : bounds) { 4564 Type subFrom = asSub(from, b.tsym); 4565 if (b.isParameterized() && 4566 (!(isUnbounded(b) || 4567 isSubtype(from, b) || 4568 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) { 4569 return true; 4570 } 4571 } 4572 return false; 4573 } 4574 4575 private List<Type> superClosure(Type t, Type s) { 4576 List<Type> cl = List.nil(); 4577 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { 4578 if (isSubtype(s, erasure(l.head))) { 4579 cl = insert(cl, l.head); 4580 } else { 4581 cl = union(cl, superClosure(l.head, s)); 4582 } 4583 } 4584 return cl; 4585 } 4586 4587 private boolean containsTypeEquivalent(Type t, Type s) { 4588 return isSameType(t, s) || // shortcut 4589 containsType(t, s) && containsType(s, t); 4590 } 4591 4592 // <editor-fold defaultstate="collapsed" desc="adapt"> 4593 /** 4594 * Adapt a type by computing a substitution which maps a source 4595 * type to a target type. 4596 * 4597 * @param source the source type 4598 * @param target the target type 4599 * @param from the type variables of the computed substitution 4600 * @param to the types of the computed substitution. 4601 */ 4602 public void adapt(Type source, 4603 Type target, 4604 ListBuffer<Type> from, 4605 ListBuffer<Type> to) throws AdaptFailure { 4606 new Adapter(from, to).adapt(source, target); 4607 } 4608 4609 class Adapter extends SimpleVisitor<Void, Type> { 4610 4611 ListBuffer<Type> from; 4612 ListBuffer<Type> to; 4613 Map<Symbol,Type> mapping; 4614 4615 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) { 4616 this.from = from; 4617 this.to = to; 4618 mapping = new HashMap<>(); 4619 } 4620 4621 public void adapt(Type source, Type target) throws AdaptFailure { 4622 visit(source, target); 4623 List<Type> fromList = from.toList(); 4624 List<Type> toList = to.toList(); 4625 while (!fromList.isEmpty()) { 4626 Type val = mapping.get(fromList.head.tsym); 4627 if (toList.head != val) 4628 toList.head = val; 4629 fromList = fromList.tail; 4630 toList = toList.tail; 4631 } 4632 } 4633 4634 @Override 4635 public Void visitClassType(ClassType source, Type target) throws AdaptFailure { 4636 if (target.hasTag(CLASS)) 4637 adaptRecursive(source.allparams(), target.allparams()); 4638 return null; 4639 } 4640 4641 @Override 4642 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure { 4643 if (target.hasTag(ARRAY)) 4644 adaptRecursive(elemtype(source), elemtype(target)); 4645 return null; 4646 } 4647 4648 @Override 4649 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure { 4650 if (source.isExtendsBound()) 4651 adaptRecursive(wildUpperBound(source), wildUpperBound(target)); 4652 else if (source.isSuperBound()) 4653 adaptRecursive(wildLowerBound(source), wildLowerBound(target)); 4654 return null; 4655 } 4656 4657 @Override 4658 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure { 4659 // Check to see if there is 4660 // already a mapping for $source$, in which case 4661 // the old mapping will be merged with the new 4662 Type val = mapping.get(source.tsym); 4663 if (val != null) { 4664 if (val.isSuperBound() && target.isSuperBound()) { 4665 val = isSubtype(wildLowerBound(val), wildLowerBound(target)) 4666 ? target : val; 4667 } else if (val.isExtendsBound() && target.isExtendsBound()) { 4668 val = isSubtype(wildUpperBound(val), wildUpperBound(target)) 4669 ? val : target; 4670 } else if (!isSameType(val, target)) { 4671 throw new AdaptFailure(); 4672 } 4673 } else { 4674 val = target; 4675 from.append(source); 4676 to.append(target); 4677 } 4678 mapping.put(source.tsym, val); 4679 return null; 4680 } 4681 4682 @Override 4683 public Void visitType(Type source, Type target) { 4684 return null; 4685 } 4686 4687 private Set<TypePair> cache = new HashSet<>(); 4688 4689 private void adaptRecursive(Type source, Type target) { 4690 TypePair pair = new TypePair(source, target); 4691 if (cache.add(pair)) { 4692 try { 4693 visit(source, target); 4694 } finally { 4695 cache.remove(pair); 4696 } 4697 } 4698 } 4699 4700 private void adaptRecursive(List<Type> source, List<Type> target) { 4701 if (source.length() == target.length()) { 4702 while (source.nonEmpty()) { 4703 adaptRecursive(source.head, target.head); 4704 source = source.tail; 4705 target = target.tail; 4706 } 4707 } 4708 } 4709 } 4710 4711 public static class AdaptFailure extends RuntimeException { 4712 static final long serialVersionUID = -7490231548272701566L; 4713 } 4714 4715 private void adaptSelf(Type t, 4716 ListBuffer<Type> from, 4717 ListBuffer<Type> to) { 4718 try { 4719 //if (t.tsym.type != t) 4720 adapt(t.tsym.type, t, from, to); 4721 } catch (AdaptFailure ex) { 4722 // Adapt should never fail calculating a mapping from 4723 // t.tsym.type to t as there can be no merge problem. 4724 throw new AssertionError(ex); 4725 } 4726 } 4727 // </editor-fold> 4728 4729 /** 4730 * Rewrite all type variables (universal quantifiers) in the given 4731 * type to wildcards (existential quantifiers). This is used to 4732 * determine if a cast is allowed. For example, if high is true 4733 * and {@code T <: Number}, then {@code List<T>} is rewritten to 4734 * {@code List<? extends Number>}. Since {@code List<Integer> <: 4735 * List<? extends Number>} a {@code List<T>} can be cast to {@code 4736 * List<Integer>} with a warning. 4737 * @param t a type 4738 * @param high if true return an upper bound; otherwise a lower 4739 * bound 4740 * @param rewriteTypeVars only rewrite captured wildcards if false; 4741 * otherwise rewrite all type variables 4742 * @return the type rewritten with wildcards (existential 4743 * quantifiers) only 4744 */ 4745 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) { 4746 return new Rewriter(high, rewriteTypeVars).visit(t); 4747 } 4748 4749 class Rewriter extends UnaryVisitor<Type> { 4750 4751 boolean high; 4752 boolean rewriteTypeVars; 4753 // map to avoid visiting same type argument twice, like in Foo<T>.Bar<T> 4754 Map<Type, Type> argMap = new HashMap<>(); 4755 // cycle detection within an argument, see JDK-8324809 4756 Set<Type> seen = new HashSet<>(); 4757 4758 Rewriter(boolean high, boolean rewriteTypeVars) { 4759 this.high = high; 4760 this.rewriteTypeVars = rewriteTypeVars; 4761 } 4762 4763 @Override 4764 public Type visitClassType(ClassType t, Void s) { 4765 ListBuffer<Type> rewritten = new ListBuffer<>(); 4766 boolean changed = false; 4767 for (Type arg : t.allparams()) { 4768 Type bound = argMap.get(arg); 4769 if (bound == null) { 4770 argMap.put(arg, bound = visit(arg)); 4771 } 4772 if (arg != bound) { 4773 changed = true; 4774 } 4775 rewritten.append(bound); 4776 } 4777 if (changed) 4778 return subst(t.tsym.type, 4779 t.tsym.type.allparams(), 4780 rewritten.toList()); 4781 else 4782 return t; 4783 } 4784 4785 public Type visitType(Type t, Void s) { 4786 return t; 4787 } 4788 4789 @Override 4790 public Type visitCapturedType(CapturedType t, Void s) { 4791 Type w_bound = t.wildcard.type; 4792 Type bound = w_bound.contains(t) ? 4793 erasure(w_bound) : 4794 visit(w_bound); 4795 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind); 4796 } 4797 4798 @Override 4799 public Type visitTypeVar(TypeVar t, Void s) { 4800 if (seen.add(t)) { 4801 if (rewriteTypeVars) { 4802 Type bound = t.getUpperBound().contains(t) ? 4803 erasure(t.getUpperBound()) : 4804 visit(t.getUpperBound()); 4805 return rewriteAsWildcardType(bound, t, EXTENDS); 4806 } else { 4807 return t; 4808 } 4809 } else { 4810 return rewriteTypeVars ? makeExtendsWildcard(syms.objectType, t) : t; 4811 } 4812 } 4813 4814 @Override 4815 public Type visitWildcardType(WildcardType t, Void s) { 4816 Type bound2 = visit(t.type); 4817 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind); 4818 } 4819 4820 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) { 4821 switch (bk) { 4822 case EXTENDS: return high ? 4823 makeExtendsWildcard(B(bound), formal) : 4824 makeExtendsWildcard(syms.objectType, formal); 4825 case SUPER: return high ? 4826 makeSuperWildcard(syms.botType, formal) : 4827 makeSuperWildcard(B(bound), formal); 4828 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal); 4829 default: 4830 Assert.error("Invalid bound kind " + bk); 4831 return null; 4832 } 4833 } 4834 4835 Type B(Type t) { 4836 while (t.hasTag(WILDCARD)) { 4837 WildcardType w = (WildcardType)t; 4838 t = high ? 4839 w.getExtendsBound() : 4840 w.getSuperBound(); 4841 if (t == null) { 4842 t = high ? syms.objectType : syms.botType; 4843 } 4844 } 4845 return t; 4846 } 4847 } 4848 4849 4850 /** 4851 * Create a wildcard with the given upper (extends) bound; create 4852 * an unbounded wildcard if bound is Object. 4853 * 4854 * @param bound the upper bound 4855 * @param formal the formal type parameter that will be 4856 * substituted by the wildcard 4857 */ 4858 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) { 4859 if (bound == syms.objectType) { 4860 return new WildcardType(syms.objectType, 4861 BoundKind.UNBOUND, 4862 syms.boundClass, 4863 formal); 4864 } else { 4865 return new WildcardType(bound, 4866 BoundKind.EXTENDS, 4867 syms.boundClass, 4868 formal); 4869 } 4870 } 4871 4872 /** 4873 * Create a wildcard with the given lower (super) bound; create an 4874 * unbounded wildcard if bound is bottom (type of {@code null}). 4875 * 4876 * @param bound the lower bound 4877 * @param formal the formal type parameter that will be 4878 * substituted by the wildcard 4879 */ 4880 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) { 4881 if (bound.hasTag(BOT)) { 4882 return new WildcardType(syms.objectType, 4883 BoundKind.UNBOUND, 4884 syms.boundClass, 4885 formal); 4886 } else { 4887 return new WildcardType(bound, 4888 BoundKind.SUPER, 4889 syms.boundClass, 4890 formal); 4891 } 4892 } 4893 4894 /** 4895 * A wrapper for a type that allows use in sets. 4896 */ 4897 public static class UniqueType { 4898 public final Type type; 4899 final Types types; 4900 4901 public UniqueType(Type type, Types types) { 4902 this.type = type; 4903 this.types = types; 4904 } 4905 4906 public int hashCode() { 4907 return types.hashCode(type); 4908 } 4909 4910 public boolean equals(Object obj) { 4911 return (obj instanceof UniqueType uniqueType) && 4912 types.isSameType(type, uniqueType.type); 4913 } 4914 4915 public String toString() { 4916 return type.toString(); 4917 } 4918 4919 } 4920 // </editor-fold> 4921 4922 // <editor-fold defaultstate="collapsed" desc="Visitors"> 4923 /** 4924 * A default visitor for types. All visitor methods except 4925 * visitType are implemented by delegating to visitType. Concrete 4926 * subclasses must provide an implementation of visitType and can 4927 * override other methods as needed. 4928 * 4929 * @param <R> the return type of the operation implemented by this 4930 * visitor; use Void if no return type is needed. 4931 * @param <S> the type of the second argument (the first being the 4932 * type itself) of the operation implemented by this visitor; use 4933 * Void if a second argument is not needed. 4934 */ 4935 public abstract static class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> { 4936 public final R visit(Type t, S s) { return t.accept(this, s); } 4937 public R visitClassType(ClassType t, S s) { return visitType(t, s); } 4938 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); } 4939 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); } 4940 public R visitMethodType(MethodType t, S s) { return visitType(t, s); } 4941 public R visitPackageType(PackageType t, S s) { return visitType(t, s); } 4942 public R visitModuleType(ModuleType t, S s) { return visitType(t, s); } 4943 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); } 4944 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); } 4945 public R visitForAll(ForAll t, S s) { return visitType(t, s); } 4946 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); } 4947 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); } 4948 } 4949 4950 /** 4951 * A default visitor for symbols. All visitor methods except 4952 * visitSymbol are implemented by delegating to visitSymbol. Concrete 4953 * subclasses must provide an implementation of visitSymbol and can 4954 * override other methods as needed. 4955 * 4956 * @param <R> the return type of the operation implemented by this 4957 * visitor; use Void if no return type is needed. 4958 * @param <S> the type of the second argument (the first being the 4959 * symbol itself) of the operation implemented by this visitor; use 4960 * Void if a second argument is not needed. 4961 */ 4962 public abstract static class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> { 4963 public final R visit(Symbol s, S arg) { return s.accept(this, arg); } 4964 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); } 4965 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); } 4966 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); } 4967 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); } 4968 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); } 4969 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); } 4970 } 4971 4972 /** 4973 * A <em>simple</em> visitor for types. This visitor is simple as 4974 * captured wildcards, for-all types (generic methods), and 4975 * undetermined type variables (part of inference) are hidden. 4976 * Captured wildcards are hidden by treating them as type 4977 * variables and the rest are hidden by visiting their qtypes. 4978 * 4979 * @param <R> the return type of the operation implemented by this 4980 * visitor; use Void if no return type is needed. 4981 * @param <S> the type of the second argument (the first being the 4982 * type itself) of the operation implemented by this visitor; use 4983 * Void if a second argument is not needed. 4984 */ 4985 public abstract static class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> { 4986 @Override 4987 public R visitCapturedType(CapturedType t, S s) { 4988 return visitTypeVar(t, s); 4989 } 4990 @Override 4991 public R visitForAll(ForAll t, S s) { 4992 return visit(t.qtype, s); 4993 } 4994 @Override 4995 public R visitUndetVar(UndetVar t, S s) { 4996 return visit(t.qtype, s); 4997 } 4998 } 4999 5000 /** 5001 * A plain relation on types. That is a 2-ary function on the 5002 * form Type × Type → Boolean. 5003 * <!-- In plain text: Type x Type -> Boolean --> 5004 */ 5005 public abstract static class TypeRelation extends SimpleVisitor<Boolean,Type> {} 5006 5007 /** 5008 * A convenience visitor for implementing operations that only 5009 * require one argument (the type itself), that is, unary 5010 * operations. 5011 * 5012 * @param <R> the return type of the operation implemented by this 5013 * visitor; use Void if no return type is needed. 5014 */ 5015 public abstract static class UnaryVisitor<R> extends SimpleVisitor<R,Void> { 5016 public final R visit(Type t) { return t.accept(this, null); } 5017 } 5018 5019 /** 5020 * A visitor for implementing a mapping from types to types. The 5021 * default behavior of this class is to implement the identity 5022 * mapping (mapping a type to itself). This can be overridden in 5023 * subclasses. 5024 * 5025 * @param <S> the type of the second argument (the first being the 5026 * type itself) of this mapping; use Void if a second argument is 5027 * not needed. 5028 */ 5029 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> { 5030 public final Type visit(Type t) { return t.accept(this, null); } 5031 public Type visitType(Type t, S s) { return t; } 5032 } 5033 5034 /** 5035 * An abstract class for mappings from types to types (see {@link Type#map(TypeMapping)}. 5036 * This class implements the functional interface {@code Function}, that allows it to be used 5037 * fluently in stream-like processing. 5038 */ 5039 public static class TypeMapping<S> extends MapVisitor<S> implements Function<Type, Type> { 5040 @Override 5041 public Type apply(Type type) { return visit(type); } 5042 5043 List<Type> visit(List<Type> ts, S s) { 5044 return ts.map(t -> visit(t, s)); 5045 } 5046 5047 @Override 5048 public Type visitCapturedType(CapturedType t, S s) { 5049 return visitTypeVar(t, s); 5050 } 5051 } 5052 // </editor-fold> 5053 5054 // <editor-fold defaultstate="collapsed" desc="Unconditionality"> 5055 /** Check unconditionality between any combination of reference or primitive types. 5056 * 5057 * Rules: 5058 * an identity conversion 5059 * a widening reference conversion 5060 * a widening primitive conversion (delegates to `checkUnconditionallyExactPrimitives`) 5061 * a boxing conversion 5062 * a boxing conversion followed by a widening reference conversion 5063 * 5064 * @param source Source primitive or reference type 5065 * @param target Target primitive or reference type 5066 */ 5067 public boolean isUnconditionallyExact(Type source, Type target) { 5068 if (isSameType(source, target)) { 5069 return true; 5070 } 5071 5072 return target.isPrimitive() 5073 ? isUnconditionallyExactPrimitives(source, target) 5074 : isSubtype(boxedTypeOrType(erasure(source)), target); 5075 } 5076 5077 /** Check unconditionality between primitive types. 5078 * 5079 * - widening from one integral type to another, 5080 * - widening from one floating point type to another, 5081 * - widening from byte, short, or char to a floating point type, 5082 * - widening from int to double. 5083 * 5084 * @param selectorType Type of selector 5085 * @param targetType Target type 5086 */ 5087 public boolean isUnconditionallyExactPrimitives(Type selectorType, Type targetType) { 5088 if (isSameType(selectorType, targetType)) { 5089 return true; 5090 } 5091 5092 return (selectorType.isPrimitive() && targetType.isPrimitive()) && 5093 ((selectorType.hasTag(BYTE) && !targetType.hasTag(CHAR)) || 5094 (selectorType.hasTag(SHORT) && (selectorType.getTag().isStrictSubRangeOf(targetType.getTag()))) || 5095 (selectorType.hasTag(CHAR) && (selectorType.getTag().isStrictSubRangeOf(targetType.getTag()))) || 5096 (selectorType.hasTag(INT) && (targetType.hasTag(DOUBLE) || targetType.hasTag(LONG))) || 5097 (selectorType.hasTag(FLOAT) && (selectorType.getTag().isStrictSubRangeOf(targetType.getTag())))); 5098 } 5099 // </editor-fold> 5100 5101 // <editor-fold defaultstate="collapsed" desc="Annotation support"> 5102 5103 public RetentionPolicy getRetention(Attribute.Compound a) { 5104 return getRetention(a.type.tsym); 5105 } 5106 5107 public RetentionPolicy getRetention(TypeSymbol sym) { 5108 RetentionPolicy vis = RetentionPolicy.CLASS; // the default 5109 Attribute.Compound c = sym.attribute(syms.retentionType.tsym); 5110 if (c != null) { 5111 Attribute value = c.member(names.value); 5112 if (value != null && value instanceof Attribute.Enum attributeEnum) { 5113 Name levelName = attributeEnum.value.name; 5114 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE; 5115 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS; 5116 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME; 5117 else ;// /* fail soft */ throw new AssertionError(levelName); 5118 } 5119 } 5120 return vis; 5121 } 5122 // </editor-fold> 5123 5124 // <editor-fold defaultstate="collapsed" desc="Signature Generation"> 5125 5126 public abstract class SignatureGenerator { 5127 5128 public class InvalidSignatureException extends CompilerInternalException { 5129 private static final long serialVersionUID = 0; 5130 5131 private final transient Type type; 5132 5133 InvalidSignatureException(Type type, boolean dumpStackTraceOnError) { 5134 super(dumpStackTraceOnError); 5135 this.type = type; 5136 } 5137 5138 public Type type() { 5139 return type; 5140 } 5141 } 5142 5143 protected abstract void append(char ch); 5144 protected abstract void append(byte[] ba); 5145 protected abstract void append(Name name); 5146 protected void classReference(ClassSymbol c) { /* by default: no-op */ } 5147 5148 protected void reportIllegalSignature(Type t) { 5149 throw new InvalidSignatureException(t, Types.this.dumpStacktraceOnError); 5150 } 5151 5152 /** 5153 * Assemble signature of given type in string buffer. 5154 */ 5155 public void assembleSig(Type type) { 5156 switch (type.getTag()) { 5157 case BYTE: 5158 append('B'); 5159 break; 5160 case SHORT: 5161 append('S'); 5162 break; 5163 case CHAR: 5164 append('C'); 5165 break; 5166 case INT: 5167 append('I'); 5168 break; 5169 case LONG: 5170 append('J'); 5171 break; 5172 case FLOAT: 5173 append('F'); 5174 break; 5175 case DOUBLE: 5176 append('D'); 5177 break; 5178 case BOOLEAN: 5179 append('Z'); 5180 break; 5181 case VOID: 5182 append('V'); 5183 break; 5184 case CLASS: 5185 if (type.isCompound()) { 5186 reportIllegalSignature(type); 5187 } 5188 append('L'); 5189 assembleClassSig(type); 5190 append(';'); 5191 break; 5192 case ARRAY: 5193 ArrayType at = (ArrayType) type; 5194 append('['); 5195 assembleSig(at.elemtype); 5196 break; 5197 case METHOD: 5198 MethodType mt = (MethodType) type; 5199 append('('); 5200 assembleSig(mt.argtypes); 5201 append(')'); 5202 assembleSig(mt.restype); 5203 if (hasTypeVar(mt.thrown)) { 5204 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) { 5205 append('^'); 5206 assembleSig(l.head); 5207 } 5208 } 5209 break; 5210 case WILDCARD: { 5211 Type.WildcardType ta = (Type.WildcardType) type; 5212 switch (ta.kind) { 5213 case SUPER: 5214 append('-'); 5215 assembleSig(ta.type); 5216 break; 5217 case EXTENDS: 5218 append('+'); 5219 assembleSig(ta.type); 5220 break; 5221 case UNBOUND: 5222 append('*'); 5223 break; 5224 default: 5225 throw new AssertionError(ta.kind); 5226 } 5227 break; 5228 } 5229 case TYPEVAR: 5230 if (((TypeVar)type).isCaptured()) { 5231 reportIllegalSignature(type); 5232 } 5233 append('T'); 5234 append(type.tsym.name); 5235 append(';'); 5236 break; 5237 case FORALL: 5238 Type.ForAll ft = (Type.ForAll) type; 5239 assembleParamsSig(ft.tvars); 5240 assembleSig(ft.qtype); 5241 break; 5242 default: 5243 throw new AssertionError("typeSig " + type.getTag()); 5244 } 5245 } 5246 5247 public boolean hasTypeVar(List<Type> l) { 5248 while (l.nonEmpty()) { 5249 if (l.head.hasTag(TypeTag.TYPEVAR)) { 5250 return true; 5251 } 5252 l = l.tail; 5253 } 5254 return false; 5255 } 5256 5257 public void assembleClassSig(Type type) { 5258 ClassType ct = (ClassType) type; 5259 ClassSymbol c = (ClassSymbol) ct.tsym; 5260 classReference(c); 5261 Type outer = ct.getEnclosingType(); 5262 if (outer.allparams().nonEmpty()) { 5263 boolean rawOuter = 5264 c.owner.kind == MTH || // either a local class 5265 c.name == Types.this.names.empty; // or anonymous 5266 assembleClassSig(rawOuter 5267 ? Types.this.erasure(outer) 5268 : outer); 5269 append(rawOuter ? '$' : '.'); 5270 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname)); 5271 append(rawOuter 5272 ? c.flatname.subName(c.owner.enclClass().flatname.length() + 1) 5273 : c.name); 5274 } else { 5275 append(externalize(c.flatname)); 5276 } 5277 if (ct.getTypeArguments().nonEmpty()) { 5278 append('<'); 5279 assembleSig(ct.getTypeArguments()); 5280 append('>'); 5281 } 5282 } 5283 5284 public void assembleParamsSig(List<Type> typarams) { 5285 append('<'); 5286 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) { 5287 Type.TypeVar tvar = (Type.TypeVar) ts.head; 5288 append(tvar.tsym.name); 5289 List<Type> bounds = Types.this.getBounds(tvar); 5290 if ((bounds.head.tsym.flags() & INTERFACE) != 0) { 5291 append(':'); 5292 } 5293 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) { 5294 append(':'); 5295 assembleSig(l.head); 5296 } 5297 } 5298 append('>'); 5299 } 5300 5301 public void assembleSig(List<Type> types) { 5302 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) { 5303 assembleSig(ts.head); 5304 } 5305 } 5306 } 5307 5308 public Type constantType(LoadableConstant c) { 5309 switch (c.poolTag()) { 5310 case ClassFile.CONSTANT_Class: 5311 return syms.classType; 5312 case ClassFile.CONSTANT_String: 5313 return syms.stringType; 5314 case ClassFile.CONSTANT_Integer: 5315 return syms.intType; 5316 case ClassFile.CONSTANT_Float: 5317 return syms.floatType; 5318 case ClassFile.CONSTANT_Long: 5319 return syms.longType; 5320 case ClassFile.CONSTANT_Double: 5321 return syms.doubleType; 5322 case ClassFile.CONSTANT_MethodHandle: 5323 return syms.methodHandleType; 5324 case ClassFile.CONSTANT_MethodType: 5325 return syms.methodTypeType; 5326 case ClassFile.CONSTANT_Dynamic: 5327 return ((DynamicVarSymbol)c).type; 5328 default: 5329 throw new AssertionError("Not a loadable constant: " + c.poolTag()); 5330 } 5331 } 5332 // </editor-fold> 5333 5334 public void newRound() { 5335 descCache._map.clear(); 5336 isDerivedRawCache.clear(); 5337 implCache._map.clear(); 5338 membersCache._map.clear(); 5339 closureCache.clear(); 5340 } 5341 } --- EOF ---