1 /* 2 * Copyright (c) 2003, 2022, 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.Entry.Kind; 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.jvm.ClassFile; 53 import com.sun.tools.javac.util.*; 54 55 import static com.sun.tools.javac.code.BoundKind.*; 56 import static com.sun.tools.javac.code.Flags.*; 57 import static com.sun.tools.javac.code.Kinds.Kind.*; 58 import static com.sun.tools.javac.code.Scope.*; 59 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 60 import static com.sun.tools.javac.code.Symbol.*; 61 import static com.sun.tools.javac.code.Type.*; 62 import static com.sun.tools.javac.code.TypeTag.*; 63 import static com.sun.tools.javac.jvm.ClassFile.externalize; 64 import com.sun.tools.javac.resources.CompilerProperties.Fragments; 65 66 /** 67 * Utility class containing various operations on types. 68 * 69 * <p>Unless other names are more illustrative, the following naming 70 * conventions should be observed in this file: 71 * 72 * <dl> 73 * <dt>t</dt> 74 * <dd>If the first argument to an operation is a type, it should be named t.</dd> 75 * <dt>s</dt> 76 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd> 77 * <dt>ts</dt> 78 * <dd>If an operations takes a list of types, the first should be named ts.</dd> 79 * <dt>ss</dt> 80 * <dd>A second list of types should be named ss.</dd> 81 * </dl> 82 * 83 * <p><b>This is NOT part of any supported API. 84 * If you write code that depends on this, you do so at your own risk. 85 * This code and its internal interfaces are subject to change or 86 * deletion without notice.</b> 87 */ 88 public class Types { 89 protected static final Context.Key<Types> typesKey = new Context.Key<>(); 90 91 final Symtab syms; 92 final JavacMessages messages; 93 final Names names; 94 final boolean allowPrimitiveClasses; 95 final Check chk; 96 final Enter enter; 97 JCDiagnostic.Factory diags; 98 List<Warner> warnStack = List.nil(); 99 final Name capturedName; 100 101 public final Warner noWarnings; 102 103 // <editor-fold defaultstate="collapsed" desc="Instantiating"> 104 public static Types instance(Context context) { 105 Types instance = context.get(typesKey); 106 if (instance == null) 107 instance = new Types(context); 108 return instance; 109 } 110 111 protected Types(Context context) { 112 context.put(typesKey, this); 113 syms = Symtab.instance(context); 114 names = Names.instance(context); 115 Source source = Source.instance(context); 116 chk = Check.instance(context); 117 enter = Enter.instance(context); 118 capturedName = names.fromString("<captured wildcard>"); 119 messages = JavacMessages.instance(context); 120 diags = JCDiagnostic.Factory.instance(context); 121 noWarnings = new Warner(null); 122 Options options = Options.instance(context); 123 allowPrimitiveClasses = Feature.PRIMITIVE_CLASSES.allowedInSource(source) && options.isSet("enablePrimitiveClasses"); 124 qualifiedSymbolCache = new HashMap<>(); 125 } 126 // </editor-fold> 127 128 // <editor-fold defaultstate="collapsed" desc="bounds"> 129 /** 130 * Get a wildcard's upper bound, returning non-wildcards unchanged. 131 * @param t a type argument, either a wildcard or a type 132 */ 133 public Type wildUpperBound(Type t) { 134 if (t.hasTag(WILDCARD)) { 135 WildcardType w = (WildcardType) t; 136 if (w.isSuperBound()) 137 return w.bound == null ? syms.objectType : w.bound.getUpperBound(); 138 else 139 return wildUpperBound(w.type); 140 } 141 else return t; 142 } 143 144 /** 145 * Get a capture variable's upper bound, returning other types unchanged. 146 * @param t a type 147 */ 148 public Type cvarUpperBound(Type t) { 149 if (t.hasTag(TYPEVAR)) { 150 TypeVar v = (TypeVar) t; 151 return v.isCaptured() ? cvarUpperBound(v.getUpperBound()) : v; 152 } 153 else return t; 154 } 155 156 /** 157 * Get a wildcard's lower bound, returning non-wildcards unchanged. 158 * @param t a type argument, either a wildcard or a type 159 */ 160 public Type wildLowerBound(Type t) { 161 if (t.hasTag(WILDCARD)) { 162 WildcardType w = (WildcardType) t; 163 return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type); 164 } 165 else return t; 166 } 167 168 /** 169 * Get a capture variable's lower bound, returning other types unchanged. 170 * @param t a type 171 */ 172 public Type cvarLowerBound(Type t) { 173 if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) { 174 return cvarLowerBound(t.getLowerBound()); 175 } 176 else return t; 177 } 178 179 /** 180 * Recursively skip type-variables until a class/array type is found; capture conversion is then 181 * (optionally) applied to the resulting type. This is useful for i.e. computing a site that is 182 * suitable for a method lookup. 183 */ 184 public Type skipTypeVars(Type site, boolean capture) { 185 while (site.hasTag(TYPEVAR)) { 186 site = site.getUpperBound(); 187 } 188 return capture ? capture(site) : site; 189 } 190 // </editor-fold> 191 192 // <editor-fold defaultstate="collapsed" desc="projections"> 193 194 /** 195 * A projection kind. See {@link TypeProjection} 196 */ 197 enum ProjectionKind { 198 UPWARDS() { 199 @Override 200 ProjectionKind complement() { 201 return DOWNWARDS; 202 } 203 }, 204 DOWNWARDS() { 205 @Override 206 ProjectionKind complement() { 207 return UPWARDS; 208 } 209 }; 210 211 abstract ProjectionKind complement(); 212 } 213 214 /** 215 * This visitor performs upwards and downwards projections on types. 216 * 217 * A projection is defined as a function that takes a type T, a set of type variables V and that 218 * produces another type S. 219 * 220 * An upwards projection maps a type T into a type S such that (i) T has no variables in V, 221 * and (ii) S is an upper bound of T. 222 * 223 * A downwards projection maps a type T into a type S such that (i) T has no variables in V, 224 * and (ii) S is a lower bound of T. 225 * 226 * Note that projections are only allowed to touch variables in V. Therefore, it is possible for 227 * a projection to leave its input type unchanged if it does not contain any variables in V. 228 * 229 * Moreover, note that while an upwards projection is always defined (every type as an upper bound), 230 * a downwards projection is not always defined. 231 * 232 * Examples: 233 * 234 * {@code upwards(List<#CAP1>, [#CAP1]) = List<? extends String>, where #CAP1 <: String } 235 * {@code downwards(List<#CAP2>, [#CAP2]) = List<? super String>, where #CAP2 :> String } 236 * {@code upwards(List<#CAP1>, [#CAP2]) = List<#CAP1> } 237 * {@code downwards(List<#CAP1>, [#CAP1]) = not defined } 238 */ 239 class TypeProjection extends TypeMapping<ProjectionKind> { 240 241 List<Type> vars; 242 Set<Type> seen = new HashSet<>(); 243 244 public TypeProjection(List<Type> vars) { 245 this.vars = vars; 246 } 247 248 @Override 249 public Type visitClassType(ClassType t, ProjectionKind pkind) { 250 if (t.isCompound()) { 251 List<Type> components = directSupertypes(t); 252 List<Type> components1 = components.map(c -> c.map(this, pkind)); 253 if (components == components1) return t; 254 else return makeIntersectionType(components1); 255 } else { 256 Type outer = t.getEnclosingType(); 257 Type outer1 = visit(outer, pkind); 258 List<Type> typarams = t.getTypeArguments(); 259 List<Type> formals = t.tsym.type.getTypeArguments(); 260 ListBuffer<Type> typarams1 = new ListBuffer<>(); 261 boolean changed = false; 262 for (Type actual : typarams) { 263 Type t2 = mapTypeArgument(t, formals.head.getUpperBound(), actual, pkind); 264 if (t2.hasTag(BOT)) { 265 //not defined 266 return syms.botType; 267 } 268 typarams1.add(t2); 269 changed |= actual != t2; 270 formals = formals.tail; 271 } 272 if (outer1 == outer && !changed) return t; 273 else return new ClassType(outer1, typarams1.toList(), t.tsym, t.getMetadata(), t.getFlavor()) { 274 @Override 275 protected boolean needsStripping() { 276 return true; 277 } 278 }; 279 } 280 } 281 282 @Override 283 public Type visitArrayType(ArrayType t, ProjectionKind s) { 284 Type elemtype = t.elemtype; 285 Type elemtype1 = visit(elemtype, s); 286 if (elemtype1 == elemtype) { 287 return t; 288 } else if (elemtype1.hasTag(BOT)) { 289 //undefined 290 return syms.botType; 291 } else { 292 return new ArrayType(elemtype1, t.tsym, t.metadata) { 293 @Override 294 protected boolean needsStripping() { 295 return true; 296 } 297 }; 298 } 299 } 300 301 @Override 302 public Type visitTypeVar(TypeVar t, ProjectionKind pkind) { 303 if (vars.contains(t)) { 304 if (seen.add(t)) { 305 try { 306 final Type bound; 307 switch (pkind) { 308 case UPWARDS: 309 bound = t.getUpperBound(); 310 break; 311 case DOWNWARDS: 312 bound = (t.getLowerBound() == null) ? 313 syms.botType : 314 t.getLowerBound(); 315 break; 316 default: 317 Assert.error(); 318 return null; 319 } 320 return bound.map(this, pkind); 321 } finally { 322 seen.remove(t); 323 } 324 } else { 325 //cycle 326 return pkind == ProjectionKind.UPWARDS ? 327 syms.objectType : syms.botType; 328 } 329 } else { 330 return t; 331 } 332 } 333 334 private Type mapTypeArgument(Type site, Type declaredBound, Type t, ProjectionKind pkind) { 335 return t.containsAny(vars) ? 336 t.map(new TypeArgumentProjection(site, declaredBound), pkind) : 337 t; 338 } 339 340 class TypeArgumentProjection extends TypeMapping<ProjectionKind> { 341 342 Type site; 343 Type declaredBound; 344 345 TypeArgumentProjection(Type site, Type declaredBound) { 346 this.site = site; 347 this.declaredBound = declaredBound; 348 } 349 350 @Override 351 public Type visitType(Type t, ProjectionKind pkind) { 352 //type argument is some type containing restricted vars 353 if (pkind == ProjectionKind.DOWNWARDS) { 354 //not defined 355 return syms.botType; 356 } 357 Type upper = t.map(TypeProjection.this, ProjectionKind.UPWARDS); 358 Type lower = t.map(TypeProjection.this, ProjectionKind.DOWNWARDS); 359 List<Type> formals = site.tsym.type.getTypeArguments(); 360 BoundKind bk; 361 Type bound; 362 if (!isSameType(upper, syms.objectType) && 363 (declaredBound.containsAny(formals) || 364 !isSubtype(declaredBound, upper))) { 365 bound = upper; 366 bk = EXTENDS; 367 } else if (!lower.hasTag(BOT)) { 368 bound = lower; 369 bk = SUPER; 370 } else { 371 bound = syms.objectType; 372 bk = UNBOUND; 373 } 374 return makeWildcard(bound, bk); 375 } 376 377 @Override 378 public Type visitWildcardType(WildcardType wt, ProjectionKind pkind) { 379 //type argument is some wildcard whose bound contains restricted vars 380 Type bound = syms.botType; 381 BoundKind bk = wt.kind; 382 switch (wt.kind) { 383 case EXTENDS: 384 bound = wt.type.map(TypeProjection.this, pkind); 385 if (bound.hasTag(BOT)) { 386 return syms.botType; 387 } 388 break; 389 case SUPER: 390 bound = wt.type.map(TypeProjection.this, pkind.complement()); 391 if (bound.hasTag(BOT)) { 392 bound = syms.objectType; 393 bk = UNBOUND; 394 } 395 break; 396 } 397 return makeWildcard(bound, bk); 398 } 399 400 private Type makeWildcard(Type bound, BoundKind bk) { 401 return new WildcardType(bound, bk, syms.boundClass) { 402 @Override 403 protected boolean needsStripping() { 404 return true; 405 } 406 }; 407 } 408 } 409 } 410 411 /** 412 * Computes an upward projection of given type, and vars. See {@link TypeProjection}. 413 * 414 * @param t the type to be projected 415 * @param vars the set of type variables to be mapped 416 * @return the type obtained as result of the projection 417 */ 418 public Type upward(Type t, List<Type> vars) { 419 return t.map(new TypeProjection(vars), ProjectionKind.UPWARDS); 420 } 421 422 /** 423 * Computes the set of captured variables mentioned in a given type. See {@link CaptureScanner}. 424 * This routine is typically used to computed the input set of variables to be used during 425 * an upwards projection (see {@link Types#upward(Type, List)}). 426 * 427 * @param t the type where occurrences of captured variables have to be found 428 * @return the set of captured variables found in t 429 */ 430 public List<Type> captures(Type t) { 431 CaptureScanner cs = new CaptureScanner(); 432 Set<Type> captures = new HashSet<>(); 433 cs.visit(t, captures); 434 return List.from(captures); 435 } 436 437 /** 438 * This visitor scans a type recursively looking for occurrences of captured type variables. 439 */ 440 class CaptureScanner extends SimpleVisitor<Void, Set<Type>> { 441 442 @Override 443 public Void visitType(Type t, Set<Type> types) { 444 return null; 445 } 446 447 @Override 448 public Void visitClassType(ClassType t, Set<Type> seen) { 449 if (t.isCompound()) { 450 directSupertypes(t).forEach(s -> visit(s, seen)); 451 } else { 452 t.allparams().forEach(ta -> visit(ta, seen)); 453 } 454 return null; 455 } 456 457 @Override 458 public Void visitArrayType(ArrayType t, Set<Type> seen) { 459 return visit(t.elemtype, seen); 460 } 461 462 @Override 463 public Void visitWildcardType(WildcardType t, Set<Type> seen) { 464 visit(t.type, seen); 465 return null; 466 } 467 468 @Override 469 public Void visitTypeVar(TypeVar t, Set<Type> seen) { 470 if ((t.tsym.flags() & Flags.SYNTHETIC) != 0 && seen.add(t)) { 471 visit(t.getUpperBound(), seen); 472 } 473 return null; 474 } 475 476 @Override 477 public Void visitCapturedType(CapturedType t, Set<Type> seen) { 478 if (seen.add(t)) { 479 visit(t.getUpperBound(), seen); 480 visit(t.getLowerBound(), seen); 481 } 482 return null; 483 } 484 } 485 486 // </editor-fold> 487 488 // <editor-fold defaultstate="collapsed" desc="isUnbounded"> 489 /** 490 * Checks that all the arguments to a class are unbounded 491 * wildcards or something else that doesn't make any restrictions 492 * on the arguments. If a class isUnbounded, a raw super- or 493 * subclass can be cast to it without a warning. 494 * @param t a type 495 * @return true iff the given type is unbounded or raw 496 */ 497 public boolean isUnbounded(Type t) { 498 return isUnbounded.visit(t); 499 } 500 // where 501 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() { 502 503 public Boolean visitType(Type t, Void ignored) { 504 return true; 505 } 506 507 @Override 508 public Boolean visitClassType(ClassType t, Void ignored) { 509 List<Type> parms = t.tsym.type.allparams(); 510 List<Type> args = t.allparams(); 511 while (parms.nonEmpty()) { 512 WildcardType unb = new WildcardType(syms.objectType, 513 BoundKind.UNBOUND, 514 syms.boundClass, 515 (TypeVar)parms.head); 516 if (!containsType(args.head, unb)) 517 return false; 518 parms = parms.tail; 519 args = args.tail; 520 } 521 return true; 522 } 523 }; 524 // </editor-fold> 525 526 // <editor-fold defaultstate="collapsed" desc="asSub"> 527 /** 528 * Return the least specific subtype of t that starts with symbol 529 * sym. If none exists, return null. The least specific subtype 530 * is determined as follows: 531 * 532 * <p>If there is exactly one parameterized instance of sym that is a 533 * subtype of t, that parameterized instance is returned.<br> 534 * Otherwise, if the plain type or raw type `sym' is a subtype of 535 * type t, the type `sym' itself is returned. Otherwise, null is 536 * returned. 537 */ 538 public Type asSub(Type t, Symbol sym) { 539 return asSub.visit(t, sym); 540 } 541 // where 542 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() { 543 544 public Type visitType(Type t, Symbol sym) { 545 return null; 546 } 547 548 @Override 549 public Type visitClassType(ClassType t, Symbol sym) { 550 if (t.tsym == sym) 551 return t; 552 Type base = asSuper(sym.type, t.tsym); 553 if (base == null) 554 return null; 555 ListBuffer<Type> from = new ListBuffer<>(); 556 ListBuffer<Type> to = new ListBuffer<>(); 557 try { 558 adapt(base, t, from, to); 559 } catch (AdaptFailure ex) { 560 return null; 561 } 562 Type res = subst(sym.type, from.toList(), to.toList()); 563 if (!isSubtype(res, t)) 564 return null; 565 ListBuffer<Type> openVars = new ListBuffer<>(); 566 for (List<Type> l = sym.type.allparams(); 567 l.nonEmpty(); l = l.tail) 568 if (res.contains(l.head) && !t.contains(l.head)) 569 openVars.append(l.head); 570 if (openVars.nonEmpty()) { 571 if (t.isRaw()) { 572 // The subtype of a raw type is raw 573 res = erasure(res); 574 } else { 575 // Unbound type arguments default to ? 576 List<Type> opens = openVars.toList(); 577 ListBuffer<Type> qs = new ListBuffer<>(); 578 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) { 579 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, 580 syms.boundClass, (TypeVar) iter.head)); 581 } 582 res = subst(res, opens, qs.toList()); 583 } 584 } 585 return res; 586 } 587 588 @Override 589 public Type visitErrorType(ErrorType t, Symbol sym) { 590 return t; 591 } 592 }; 593 // </editor-fold> 594 595 // <editor-fold defaultstate="collapsed" desc="isConvertible"> 596 /** 597 * Is t a subtype of or convertible via boxing/unboxing 598 * conversion to s? 599 */ 600 public boolean isConvertible(Type t, Type s, Warner warn) { 601 if (t.hasTag(ERROR)) { 602 return true; 603 } 604 605 if (allowPrimitiveClasses) { 606 boolean tValue = t.isPrimitiveClass(); 607 boolean sValue = s.isPrimitiveClass(); 608 if (tValue != sValue) { 609 return tValue ? 610 isSubtype(t.referenceProjection(), s) : 611 !t.hasTag(BOT) && isSubtype(t, s.referenceProjection()); 612 } 613 } 614 615 boolean tPrimitive = t.isPrimitive(); 616 boolean sPrimitive = s.isPrimitive(); 617 if (tPrimitive == sPrimitive) { 618 return isSubtypeUnchecked(t, s, warn); 619 } 620 boolean tUndet = t.hasTag(UNDETVAR); 621 boolean sUndet = s.hasTag(UNDETVAR); 622 623 if (tUndet || sUndet) { 624 return tUndet ? 625 isSubtype(t, boxedTypeOrType(s)) : 626 isSubtype(boxedTypeOrType(t), s); 627 } 628 629 return tPrimitive 630 ? isSubtype(boxedClass(t).type, s) 631 : isSubtype(unboxedType(t), s); 632 } 633 634 /** 635 * Is t a subtype of or convertible via boxing/unboxing 636 * conversions to s? 637 */ 638 public boolean isConvertible(Type t, Type s) { 639 return isConvertible(t, s, noWarnings); 640 } 641 // </editor-fold> 642 643 // <editor-fold defaultstate="collapsed" desc="findSam"> 644 645 /** 646 * Exception used to report a function descriptor lookup failure. The exception 647 * wraps a diagnostic that can be used to generate more details error 648 * messages. 649 */ 650 public static class FunctionDescriptorLookupError extends RuntimeException { 651 private static final long serialVersionUID = 0; 652 653 transient JCDiagnostic diagnostic; 654 655 FunctionDescriptorLookupError() { 656 this.diagnostic = null; 657 } 658 659 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) { 660 this.diagnostic = diag; 661 return this; 662 } 663 664 public JCDiagnostic getDiagnostic() { 665 return diagnostic; 666 } 667 668 @Override 669 public Throwable fillInStackTrace() { 670 // This is an internal exception; the stack trace is irrelevant. 671 return this; 672 } 673 } 674 675 /** 676 * A cache that keeps track of function descriptors associated with given 677 * functional interfaces. 678 */ 679 class DescriptorCache { 680 681 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>(); 682 683 class FunctionDescriptor { 684 Symbol descSym; 685 686 FunctionDescriptor(Symbol descSym) { 687 this.descSym = descSym; 688 } 689 690 public Symbol getSymbol() { 691 return descSym; 692 } 693 694 public Type getType(Type site) { 695 site = removeWildcards(site); 696 if (site.isIntersection()) { 697 IntersectionClassType ict = (IntersectionClassType)site; 698 for (Type component : ict.getExplicitComponents()) { 699 if (!chk.checkValidGenericType(component)) { 700 //if the inferred functional interface type is not well-formed, 701 //or if it's not a subtype of the original target, issue an error 702 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site))); 703 } 704 } 705 } else { 706 if (!chk.checkValidGenericType(site)) { 707 //if the inferred functional interface type is not well-formed, 708 //or if it's not a subtype of the original target, issue an error 709 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site))); 710 } 711 } 712 return memberType(site, descSym); 713 } 714 } 715 716 class Entry { 717 final FunctionDescriptor cachedDescRes; 718 final int prevMark; 719 720 public Entry(FunctionDescriptor cachedDescRes, 721 int prevMark) { 722 this.cachedDescRes = cachedDescRes; 723 this.prevMark = prevMark; 724 } 725 726 boolean matches(int mark) { 727 return this.prevMark == mark; 728 } 729 } 730 731 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError { 732 Entry e = _map.get(origin); 733 CompoundScope members = membersClosure(origin.type, false); 734 if (e == null || 735 !e.matches(members.getMark())) { 736 FunctionDescriptor descRes = findDescriptorInternal(origin, members); 737 _map.put(origin, new Entry(descRes, members.getMark())); 738 return descRes; 739 } 740 else { 741 return e.cachedDescRes; 742 } 743 } 744 745 /** 746 * Compute the function descriptor associated with a given functional interface 747 */ 748 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin, 749 CompoundScope membersCache) throws FunctionDescriptorLookupError { 750 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0 || origin.isSealed()) { 751 //t must be an interface 752 throw failure("not.a.functional.intf", origin); 753 } 754 755 final ListBuffer<Symbol> abstracts = new ListBuffer<>(); 756 for (Symbol sym : membersCache.getSymbols(new DescriptorFilter(origin))) { 757 Type mtype = memberType(origin.type, sym); 758 if (abstracts.isEmpty()) { 759 abstracts.append(sym); 760 } else if ((sym.name == abstracts.first().name && 761 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) { 762 if (!abstracts.stream().filter(msym -> msym.owner.isSubClass(sym.enclClass(), Types.this)) 763 .map(msym -> memberType(origin.type, msym)) 764 .anyMatch(abstractMType -> isSubSignature(abstractMType, mtype))) { 765 abstracts.append(sym); 766 } 767 } else { 768 //the target method(s) should be the only abstract members of t 769 throw failure("not.a.functional.intf.1", origin, 770 diags.fragment(Fragments.IncompatibleAbstracts(Kinds.kindName(origin), origin))); 771 } 772 } 773 if (abstracts.isEmpty()) { 774 //t must define a suitable non-generic method 775 throw failure("not.a.functional.intf.1", origin, 776 diags.fragment(Fragments.NoAbstracts(Kinds.kindName(origin), origin))); 777 } 778 FunctionDescriptor descRes; 779 if (abstracts.size() == 1) { 780 descRes = new FunctionDescriptor(abstracts.first()); 781 } else { // size > 1 782 descRes = mergeDescriptors(origin, abstracts.toList()); 783 if (descRes == null) { 784 //we can get here if the functional interface is ill-formed 785 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>(); 786 for (Symbol desc : abstracts) { 787 String key = desc.type.getThrownTypes().nonEmpty() ? 788 "descriptor.throws" : "descriptor"; 789 descriptors.append(diags.fragment(key, desc.name, 790 desc.type.getParameterTypes(), 791 desc.type.getReturnType(), 792 desc.type.getThrownTypes())); 793 } 794 JCDiagnostic msg = 795 diags.fragment(Fragments.IncompatibleDescsInFunctionalIntf(Kinds.kindName(origin), 796 origin)); 797 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors = 798 new JCDiagnostic.MultilineDiagnostic(msg, descriptors.toList()); 799 throw failure(incompatibleDescriptors); 800 } 801 } 802 // an interface must be neither an identity interface nor a value interface to be functional. 803 List<Type> allInterfaces = closure(origin.type); 804 for (Type iface : allInterfaces) { 805 if (iface.isValueInterface()) { 806 throw failure("not.a.functional.intf.1", origin, diags.fragment(Fragments.ValueInterfaceNonfunctional)); 807 } 808 if (iface.isIdentityInterface()) { 809 throw failure("not.a.functional.intf.1", origin, diags.fragment(Fragments.IdentityInterfaceNonfunctional)); 810 } 811 } 812 return descRes; 813 } 814 815 /** 816 * Compute a synthetic type for the target descriptor given a list 817 * of override-equivalent methods in the functional interface type. 818 * The resulting method type is a method type that is override-equivalent 819 * and return-type substitutable with each method in the original list. 820 */ 821 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) { 822 return mergeAbstracts(methodSyms, origin.type, false) 823 .map(bestSoFar -> new FunctionDescriptor(bestSoFar.baseSymbol()) { 824 @Override 825 public Type getType(Type origin) { 826 Type mt = memberType(origin, getSymbol()); 827 return createMethodTypeWithThrown(mt, bestSoFar.type.getThrownTypes()); 828 } 829 }).orElse(null); 830 } 831 832 FunctionDescriptorLookupError failure(String msg, Object... args) { 833 return failure(diags.fragment(msg, args)); 834 } 835 836 FunctionDescriptorLookupError failure(JCDiagnostic diag) { 837 return new FunctionDescriptorLookupError().setMessage(diag); 838 } 839 } 840 841 private DescriptorCache descCache = new DescriptorCache(); 842 843 /** 844 * Find the method descriptor associated to this class symbol - if the 845 * symbol 'origin' is not a functional interface, an exception is thrown. 846 */ 847 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError { 848 return descCache.get(origin).getSymbol(); 849 } 850 851 /** 852 * Find the type of the method descriptor associated to this class symbol - 853 * if the symbol 'origin' is not a functional interface, an exception is thrown. 854 */ 855 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError { 856 return descCache.get(origin.tsym).getType(origin); 857 } 858 859 /** 860 * Is given type a functional interface? 861 */ 862 public boolean isFunctionalInterface(TypeSymbol tsym) { 863 try { 864 findDescriptorSymbol(tsym); 865 return true; 866 } catch (FunctionDescriptorLookupError ex) { 867 return false; 868 } 869 } 870 871 public boolean isFunctionalInterface(Type site) { 872 try { 873 findDescriptorType(site); 874 return true; 875 } catch (FunctionDescriptorLookupError ex) { 876 return false; 877 } 878 } 879 880 public Type removeWildcards(Type site) { 881 if (site.getTypeArguments().stream().anyMatch(t -> t.hasTag(WILDCARD))) { 882 //compute non-wildcard parameterization - JLS 9.9 883 List<Type> actuals = site.getTypeArguments(); 884 List<Type> formals = site.tsym.type.getTypeArguments(); 885 ListBuffer<Type> targs = new ListBuffer<>(); 886 for (Type formal : formals) { 887 Type actual = actuals.head; 888 Type bound = formal.getUpperBound(); 889 if (actuals.head.hasTag(WILDCARD)) { 890 WildcardType wt = (WildcardType)actual; 891 //check that bound does not contain other formals 892 if (bound.containsAny(formals)) { 893 targs.add(wt.type); 894 } else { 895 //compute new type-argument based on declared bound and wildcard bound 896 switch (wt.kind) { 897 case UNBOUND: 898 targs.add(bound); 899 break; 900 case EXTENDS: 901 targs.add(glb(bound, wt.type)); 902 break; 903 case SUPER: 904 targs.add(wt.type); 905 break; 906 default: 907 Assert.error("Cannot get here!"); 908 } 909 } 910 } else { 911 //not a wildcard - the new type argument remains unchanged 912 targs.add(actual); 913 } 914 actuals = actuals.tail; 915 } 916 return subst(site.tsym.type, formals, targs.toList()); 917 } else { 918 return site; 919 } 920 } 921 922 /** 923 * Create a symbol for a class that implements a given functional interface 924 * and overrides its functional descriptor. This routine is used for two 925 * main purposes: (i) checking well-formedness of a functional interface; 926 * (ii) perform functional interface bridge calculation. 927 */ 928 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, Type target, long cflags) { 929 if (target == null || target == syms.unknownType) { 930 return null; 931 } 932 Symbol descSym = findDescriptorSymbol(target.tsym); 933 Type descType = findDescriptorType(target); 934 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass()); 935 csym.completer = Completer.NULL_COMPLETER; 936 csym.members_field = WriteableScope.create(csym); 937 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym); 938 csym.members_field.enter(instDescSym); 939 Type.ClassType ctype = new Type.ClassType(Type.noType, List.nil(), csym); 940 ctype.supertype_field = syms.objectType; 941 ctype.interfaces_field = target.isIntersection() ? 942 directSupertypes(target) : 943 List.of(target); 944 csym.type = ctype; 945 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile; 946 return csym; 947 } 948 949 /** 950 * Find the minimal set of methods that are overridden by the functional 951 * descriptor in 'origin'. All returned methods are assumed to have different 952 * erased signatures. 953 */ 954 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) { 955 Assert.check(isFunctionalInterface(origin)); 956 Symbol descSym = findDescriptorSymbol(origin); 957 CompoundScope members = membersClosure(origin.type, false); 958 ListBuffer<Symbol> overridden = new ListBuffer<>(); 959 outer: for (Symbol m2 : members.getSymbolsByName(descSym.name, bridgeFilter)) { 960 if (m2 == descSym) continue; 961 else if (descSym.overrides(m2, origin, Types.this, false)) { 962 for (Symbol m3 : overridden) { 963 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) || 964 (m3.overrides(m2, origin, Types.this, false) && 965 (pendingBridges((ClassSymbol)origin, m3.enclClass()) || 966 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) { 967 continue outer; 968 } 969 } 970 overridden.add(m2); 971 } 972 } 973 return overridden.toList(); 974 } 975 //where 976 // Use anonymous class instead of lambda expression intentionally, 977 // because the variable `names` has modifier: final. 978 private Predicate<Symbol> bridgeFilter = new Predicate<Symbol>() { 979 public boolean test(Symbol t) { 980 return t.kind == MTH && 981 !names.isInitOrVNew(t.name) && 982 t.name != names.clinit && 983 (t.flags() & SYNTHETIC) == 0; 984 } 985 }; 986 987 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) { 988 //a symbol will be completed from a classfile if (a) symbol has 989 //an associated file object with CLASS kind and (b) the symbol has 990 //not been entered 991 if (origin.classfile != null && 992 origin.classfile.getKind() == JavaFileObject.Kind.CLASS && 993 enter.getEnv(origin) == null) { 994 return false; 995 } 996 if (origin == s) { 997 return true; 998 } 999 for (Type t : interfaces(origin.type)) { 1000 if (pendingBridges((ClassSymbol)t.tsym, s)) { 1001 return true; 1002 } 1003 } 1004 return false; 1005 } 1006 // </editor-fold> 1007 1008 /** 1009 * Scope filter used to skip methods that should be ignored (such as methods 1010 * overridden by j.l.Object) during function interface conversion interface check 1011 */ 1012 class DescriptorFilter implements Predicate<Symbol> { 1013 1014 TypeSymbol origin; 1015 1016 DescriptorFilter(TypeSymbol origin) { 1017 this.origin = origin; 1018 } 1019 1020 @Override 1021 public boolean test(Symbol sym) { 1022 return sym.kind == MTH && 1023 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT && 1024 !overridesObjectMethod(origin, sym) && 1025 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0; 1026 } 1027 } 1028 1029 // <editor-fold defaultstate="collapsed" desc="isSubtype"> 1030 /** 1031 * Is t an unchecked subtype of s? 1032 */ 1033 public boolean isSubtypeUnchecked(Type t, Type s) { 1034 return isSubtypeUnchecked(t, s, noWarnings); 1035 } 1036 /** 1037 * Is t an unchecked subtype of s? 1038 */ 1039 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) { 1040 boolean result = isSubtypeUncheckedInternal(t, s, true, warn); 1041 if (result) { 1042 checkUnsafeVarargsConversion(t, s, warn); 1043 } 1044 return result; 1045 } 1046 //where 1047 private boolean isSubtypeUncheckedInternal(Type t, Type s, boolean capture, Warner warn) { 1048 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) { 1049 if (((ArrayType)t).elemtype.isPrimitive()) { 1050 return isSameType(elemtype(t), elemtype(s)); 1051 } else { 1052 // if T.ref <: S, then T[] <: S[] 1053 Type es = elemtype(s); 1054 Type et = elemtype(t); 1055 if (allowPrimitiveClasses) { 1056 if (et.isPrimitiveClass()) { 1057 et = et.referenceProjection(); 1058 if (es.isPrimitiveClass()) 1059 es = es.referenceProjection(); // V <: V, surely 1060 } 1061 } 1062 if (!isSubtypeUncheckedInternal(et, es, false, warn)) 1063 return false; 1064 return true; 1065 } 1066 } else if (isSubtype(t, s, capture)) { 1067 return true; 1068 } else if (t.hasTag(TYPEVAR)) { 1069 return isSubtypeUncheckedInternal(t.getUpperBound(), s, false, warn); 1070 } else if (!s.isRaw()) { 1071 Type t2 = asSuper(t, s.tsym); 1072 if (t2 != null && t2.isRaw()) { 1073 if (isReifiable(s)) { 1074 warn.silentWarn(LintCategory.UNCHECKED); 1075 } else { 1076 warn.warn(LintCategory.UNCHECKED); 1077 } 1078 return true; 1079 } 1080 } 1081 return false; 1082 } 1083 1084 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) { 1085 if (!t.hasTag(ARRAY) || isReifiable(t)) { 1086 return; 1087 } 1088 ArrayType from = (ArrayType)t; 1089 boolean shouldWarn = false; 1090 switch (s.getTag()) { 1091 case ARRAY: 1092 ArrayType to = (ArrayType)s; 1093 shouldWarn = from.isVarargs() && 1094 !to.isVarargs() && 1095 !isReifiable(from); 1096 break; 1097 case CLASS: 1098 shouldWarn = from.isVarargs(); 1099 break; 1100 } 1101 if (shouldWarn) { 1102 warn.warn(LintCategory.VARARGS); 1103 } 1104 } 1105 1106 /** 1107 * Is t a subtype of s?<br> 1108 * (not defined for Method and ForAll types) 1109 */ 1110 public final boolean isSubtype(Type t, Type s) { 1111 return isSubtype(t, s, true); 1112 } 1113 public final boolean isSubtypeNoCapture(Type t, Type s) { 1114 return isSubtype(t, s, false); 1115 } 1116 public boolean isSubtype(Type t, Type s, boolean capture) { 1117 if (t.equalsIgnoreMetadata(s)) 1118 return true; 1119 if (s.isPartial()) 1120 return isSuperType(s, t); 1121 1122 if (s.isCompound()) { 1123 for (Type s2 : interfaces(s).prepend(supertype(s))) { 1124 if (!isSubtype(t, s2, capture)) 1125 return false; 1126 } 1127 return true; 1128 } 1129 1130 // Generally, if 's' is a lower-bounded type variable, recur on lower bound; but 1131 // for inference variables and intersections, we need to keep 's' 1132 // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars) 1133 if (!t.hasTag(UNDETVAR) && !t.isCompound()) { 1134 // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s 1135 Type lower = cvarLowerBound(wildLowerBound(s)); 1136 if (s != lower && !lower.hasTag(BOT)) 1137 return isSubtype(capture ? capture(t) : t, lower, false); 1138 } 1139 1140 return isSubtype.visit(capture ? capture(t) : t, s); 1141 } 1142 // where 1143 private TypeRelation isSubtype = new TypeRelation() 1144 { 1145 @Override 1146 public Boolean visitType(Type t, Type s) { 1147 switch (t.getTag()) { 1148 case BYTE: 1149 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag())); 1150 case CHAR: 1151 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag())); 1152 case SHORT: case INT: case LONG: 1153 case FLOAT: case DOUBLE: 1154 return t.getTag().isSubRangeOf(s.getTag()); 1155 case BOOLEAN: case VOID: 1156 return t.hasTag(s.getTag()); 1157 case TYPEVAR: 1158 return isSubtypeNoCapture(t.getUpperBound(), s); 1159 case BOT: 1160 return 1161 s.hasTag(BOT) || (s.hasTag(CLASS) && (!allowPrimitiveClasses || !s.isPrimitiveClass())) || 1162 s.hasTag(ARRAY) || s.hasTag(TYPEVAR); 1163 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495) 1164 case NONE: 1165 return false; 1166 default: 1167 throw new AssertionError("isSubtype " + t.getTag()); 1168 } 1169 } 1170 1171 private Set<TypePair> cache = new HashSet<>(); 1172 1173 private boolean containsTypeRecursive(Type t, Type s) { 1174 TypePair pair = new TypePair(t, s); 1175 if (cache.add(pair)) { 1176 try { 1177 return containsType(t.getTypeArguments(), 1178 s.getTypeArguments()); 1179 } finally { 1180 cache.remove(pair); 1181 } 1182 } else { 1183 return containsType(t.getTypeArguments(), 1184 rewriteSupers(s).getTypeArguments()); 1185 } 1186 } 1187 1188 private Type rewriteSupers(Type t) { 1189 if (!t.isParameterized()) 1190 return t; 1191 ListBuffer<Type> from = new ListBuffer<>(); 1192 ListBuffer<Type> to = new ListBuffer<>(); 1193 adaptSelf(t, from, to); 1194 if (from.isEmpty()) 1195 return t; 1196 ListBuffer<Type> rewrite = new ListBuffer<>(); 1197 boolean changed = false; 1198 for (Type orig : to.toList()) { 1199 Type s = rewriteSupers(orig); 1200 if (s.isSuperBound() && !s.isExtendsBound()) { 1201 s = new WildcardType(syms.objectType, 1202 BoundKind.UNBOUND, 1203 syms.boundClass, 1204 s.getMetadata()); 1205 changed = true; 1206 } else if (s != orig) { 1207 s = new WildcardType(wildUpperBound(s), 1208 BoundKind.EXTENDS, 1209 syms.boundClass, 1210 s.getMetadata()); 1211 changed = true; 1212 } 1213 rewrite.append(s); 1214 } 1215 if (changed) 1216 return subst(t.tsym.type, from.toList(), rewrite.toList()); 1217 else 1218 return t; 1219 } 1220 1221 @Override 1222 public Boolean visitClassType(ClassType t, Type s) { 1223 Type sup = asSuper(t, s.tsym); 1224 if (sup == null) return false; 1225 // If t is an intersection, sup might not be a class type 1226 if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s); 1227 return sup.tsym == s.tsym 1228 && (t.tsym != s.tsym || t.isReferenceProjection() == s.isReferenceProjection()) 1229 // Check type variable containment 1230 && (!s.isParameterized() || containsTypeRecursive(s, sup)) 1231 && isSubtypeNoCapture(sup.getEnclosingType(), 1232 s.getEnclosingType()); 1233 } 1234 1235 @Override 1236 public Boolean visitArrayType(ArrayType t, Type s) { 1237 if (s.hasTag(ARRAY)) { 1238 if (t.elemtype.isPrimitive()) 1239 return isSameType(t.elemtype, elemtype(s)); 1240 else { 1241 // if T.ref <: S, then T[] <: S[] 1242 Type es = elemtype(s); 1243 Type et = elemtype(t); 1244 if (allowPrimitiveClasses && et.isPrimitiveClass()) { 1245 et = et.referenceProjection(); 1246 if (es.isPrimitiveClass()) 1247 es = es.referenceProjection(); // V <: V, surely 1248 } 1249 return isSubtypeNoCapture(et, es); 1250 } 1251 } 1252 1253 if (s.hasTag(CLASS)) { 1254 Name sname = s.tsym.getQualifiedName(); 1255 return sname == names.java_lang_Object 1256 || sname == names.java_lang_Cloneable 1257 || sname == names.java_io_Serializable; 1258 } 1259 1260 return false; 1261 } 1262 1263 @Override 1264 public Boolean visitUndetVar(UndetVar t, Type s) { 1265 //todo: test against origin needed? or replace with substitution? 1266 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) { 1267 return true; 1268 } else if (s.hasTag(BOT)) { 1269 //if 's' is 'null' there's no instantiated type U for which 1270 //U <: s (but 'null' itself, which is not a valid type) 1271 return false; 1272 } 1273 1274 t.addBound(InferenceBound.UPPER, s, Types.this); 1275 return true; 1276 } 1277 1278 @Override 1279 public Boolean visitErrorType(ErrorType t, Type s) { 1280 return true; 1281 } 1282 }; 1283 1284 /** 1285 * Is t a subtype of every type in given list `ts'?<br> 1286 * (not defined for Method and ForAll types)<br> 1287 * Allows unchecked conversions. 1288 */ 1289 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) { 1290 for (List<Type> l = ts; l.nonEmpty(); l = l.tail) 1291 if (!isSubtypeUnchecked(t, l.head, warn)) 1292 return false; 1293 return true; 1294 } 1295 1296 /** 1297 * Are corresponding elements of ts subtypes of ss? If lists are 1298 * of different length, return false. 1299 */ 1300 public boolean isSubtypes(List<Type> ts, List<Type> ss) { 1301 while (ts.tail != null && ss.tail != null 1302 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1303 isSubtype(ts.head, ss.head)) { 1304 ts = ts.tail; 1305 ss = ss.tail; 1306 } 1307 return ts.tail == null && ss.tail == null; 1308 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1309 } 1310 1311 /** 1312 * Are corresponding elements of ts subtypes of ss, allowing 1313 * unchecked conversions? If lists are of different length, 1314 * return false. 1315 **/ 1316 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) { 1317 while (ts.tail != null && ss.tail != null 1318 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1319 isSubtypeUnchecked(ts.head, ss.head, warn)) { 1320 ts = ts.tail; 1321 ss = ss.tail; 1322 } 1323 return ts.tail == null && ss.tail == null; 1324 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1325 } 1326 // </editor-fold> 1327 1328 // <editor-fold defaultstate="collapsed" desc="isSuperType"> 1329 /** 1330 * Is t a supertype of s? 1331 */ 1332 public boolean isSuperType(Type t, Type s) { 1333 switch (t.getTag()) { 1334 case ERROR: 1335 return true; 1336 case UNDETVAR: { 1337 UndetVar undet = (UndetVar)t; 1338 if (t == s || 1339 undet.qtype == s || 1340 s.hasTag(ERROR) || 1341 s.hasTag(BOT)) { 1342 return true; 1343 } 1344 undet.addBound(InferenceBound.LOWER, s, this); 1345 return true; 1346 } 1347 default: 1348 return isSubtype(s, t); 1349 } 1350 } 1351 // </editor-fold> 1352 1353 // <editor-fold defaultstate="collapsed" desc="isSameType"> 1354 /** 1355 * Are corresponding elements of the lists the same type? If 1356 * lists are of different length, return false. 1357 */ 1358 public boolean isSameTypes(List<Type> ts, List<Type> ss) { 1359 while (ts.tail != null && ss.tail != null 1360 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1361 isSameType(ts.head, ss.head)) { 1362 ts = ts.tail; 1363 ss = ss.tail; 1364 } 1365 return ts.tail == null && ss.tail == null; 1366 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1367 } 1368 1369 /** 1370 * A polymorphic signature method (JLS 15.12.3) is a method that 1371 * (i) is declared in the java.lang.invoke.MethodHandle/VarHandle classes; 1372 * (ii) takes a single variable arity parameter; 1373 * (iii) whose declared type is Object[]; 1374 * (iv) has any return type, Object signifying a polymorphic return type; and 1375 * (v) is native. 1376 */ 1377 public boolean isSignaturePolymorphic(MethodSymbol msym) { 1378 List<Type> argtypes = msym.type.getParameterTypes(); 1379 return (msym.flags_field & NATIVE) != 0 && 1380 (msym.owner == syms.methodHandleType.tsym || msym.owner == syms.varHandleType.tsym) && 1381 argtypes.length() == 1 && 1382 argtypes.head.hasTag(TypeTag.ARRAY) && 1383 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym; 1384 } 1385 1386 /** 1387 * Is t the same type as s? 1388 */ 1389 public boolean isSameType(Type t, Type s) { 1390 return isSameTypeVisitor.visit(t, s); 1391 } 1392 // where 1393 1394 /** 1395 * Type-equality relation - type variables are considered 1396 * equals if they share the same object identity. 1397 */ 1398 TypeRelation isSameTypeVisitor = new TypeRelation() { 1399 1400 public Boolean visitType(Type t, Type s) { 1401 if (t.equalsIgnoreMetadata(s)) 1402 return true; 1403 1404 if (s.isPartial()) 1405 return visit(s, t); 1406 1407 switch (t.getTag()) { 1408 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: 1409 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE: 1410 return t.hasTag(s.getTag()); 1411 case TYPEVAR: { 1412 if (s.hasTag(TYPEVAR)) { 1413 //type-substitution does not preserve type-var types 1414 //check that type var symbols and bounds are indeed the same 1415 return t == s; 1416 } 1417 else { 1418 //special case for s == ? super X, where upper(s) = u 1419 //check that u == t, where u has been set by Type.withTypeVar 1420 return s.isSuperBound() && 1421 !s.isExtendsBound() && 1422 visit(t, wildUpperBound(s)); 1423 } 1424 } 1425 default: 1426 throw new AssertionError("isSameType " + t.getTag()); 1427 } 1428 } 1429 1430 @Override 1431 public Boolean visitWildcardType(WildcardType t, Type s) { 1432 if (!s.hasTag(WILDCARD)) { 1433 return false; 1434 } else { 1435 WildcardType t2 = (WildcardType)s; 1436 return (t.kind == t2.kind || (t.isExtendsBound() && s.isExtendsBound())) && 1437 isSameType(t.type, t2.type); 1438 } 1439 } 1440 1441 @Override 1442 public Boolean visitClassType(ClassType t, Type s) { 1443 if (t == s) 1444 return true; 1445 1446 if (s.isPartial()) 1447 return visit(s, t); 1448 1449 if (s.isSuperBound() && !s.isExtendsBound()) 1450 return visit(t, wildUpperBound(s)) && visit(t, wildLowerBound(s)); 1451 1452 if (t.isCompound() && s.isCompound()) { 1453 if (!visit(supertype(t), supertype(s))) 1454 return false; 1455 1456 Map<Symbol,Type> tMap = new HashMap<>(); 1457 for (Type ti : interfaces(t)) { 1458 if (tMap.containsKey(ti)) { 1459 throw new AssertionError("Malformed intersection"); 1460 } 1461 tMap.put(ti.tsym, ti); 1462 } 1463 for (Type si : interfaces(s)) { 1464 if (!tMap.containsKey(si.tsym)) 1465 return false; 1466 Type ti = tMap.remove(si.tsym); 1467 if (!visit(ti, si)) 1468 return false; 1469 } 1470 return tMap.isEmpty(); 1471 } 1472 return t.tsym == s.tsym 1473 && t.isReferenceProjection() == s.isReferenceProjection() 1474 && visit(getEnclosingType(t), getEnclosingType(s)) 1475 && containsTypeEquivalent(t.getTypeArguments(), s.getTypeArguments()); 1476 } 1477 // where 1478 private Type getEnclosingType(Type t) { 1479 Type et = t.getEnclosingType(); 1480 if (et.isReferenceProjection()) { 1481 et = et.valueProjection(); 1482 } 1483 return et; 1484 } 1485 1486 @Override 1487 public Boolean visitArrayType(ArrayType t, Type s) { 1488 if (t == s) 1489 return true; 1490 1491 if (s.isPartial()) 1492 return visit(s, t); 1493 1494 return s.hasTag(ARRAY) 1495 && containsTypeEquivalent(t.elemtype, elemtype(s)); 1496 } 1497 1498 @Override 1499 public Boolean visitMethodType(MethodType t, Type s) { 1500 // isSameType for methods does not take thrown 1501 // exceptions into account! 1502 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType()); 1503 } 1504 1505 @Override 1506 public Boolean visitPackageType(PackageType t, Type s) { 1507 return t == s; 1508 } 1509 1510 @Override 1511 public Boolean visitForAll(ForAll t, Type s) { 1512 if (!s.hasTag(FORALL)) { 1513 return false; 1514 } 1515 1516 ForAll forAll = (ForAll)s; 1517 return hasSameBounds(t, forAll) 1518 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); 1519 } 1520 1521 @Override 1522 public Boolean visitUndetVar(UndetVar t, Type s) { 1523 if (s.hasTag(WILDCARD)) { 1524 // FIXME, this might be leftovers from before capture conversion 1525 return false; 1526 } 1527 1528 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) { 1529 return true; 1530 } 1531 1532 t.addBound(InferenceBound.EQ, s, Types.this); 1533 1534 return true; 1535 } 1536 1537 @Override 1538 public Boolean visitErrorType(ErrorType t, Type s) { 1539 return true; 1540 } 1541 }; 1542 1543 // </editor-fold> 1544 1545 // <editor-fold defaultstate="collapsed" desc="Contains Type"> 1546 public boolean containedBy(Type t, Type s) { 1547 switch (t.getTag()) { 1548 case UNDETVAR: 1549 if (s.hasTag(WILDCARD)) { 1550 UndetVar undetvar = (UndetVar)t; 1551 WildcardType wt = (WildcardType)s; 1552 switch(wt.kind) { 1553 case UNBOUND: 1554 break; 1555 case EXTENDS: { 1556 Type bound = wildUpperBound(s); 1557 undetvar.addBound(InferenceBound.UPPER, bound, this); 1558 break; 1559 } 1560 case SUPER: { 1561 Type bound = wildLowerBound(s); 1562 undetvar.addBound(InferenceBound.LOWER, bound, this); 1563 break; 1564 } 1565 } 1566 return true; 1567 } else { 1568 return isSameType(t, s); 1569 } 1570 case ERROR: 1571 return true; 1572 default: 1573 return containsType(s, t); 1574 } 1575 } 1576 1577 boolean containsType(List<Type> ts, List<Type> ss) { 1578 while (ts.nonEmpty() && ss.nonEmpty() 1579 && containsType(ts.head, ss.head)) { 1580 ts = ts.tail; 1581 ss = ss.tail; 1582 } 1583 return ts.isEmpty() && ss.isEmpty(); 1584 } 1585 1586 /** 1587 * Check if t contains s. 1588 * 1589 * <p>T contains S if: 1590 * 1591 * <p>{@code L(T) <: L(S) && U(S) <: U(T)} 1592 * 1593 * <p>This relation is only used by ClassType.isSubtype(), that 1594 * is, 1595 * 1596 * <p>{@code C<S> <: C<T> if T contains S.} 1597 * 1598 * <p>Because of F-bounds, this relation can lead to infinite 1599 * recursion. Thus we must somehow break that recursion. Notice 1600 * that containsType() is only called from ClassType.isSubtype(). 1601 * Since the arguments have already been checked against their 1602 * bounds, we know: 1603 * 1604 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)} 1605 * 1606 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)} 1607 * 1608 * @param t a type 1609 * @param s a type 1610 */ 1611 public boolean containsType(Type t, Type s) { 1612 return containsType.visit(t, s); 1613 } 1614 // where 1615 private TypeRelation containsType = new TypeRelation() { 1616 1617 public Boolean visitType(Type t, Type s) { 1618 if (s.isPartial()) 1619 return containedBy(s, t); 1620 else 1621 return isSameType(t, s); 1622 } 1623 1624 // void debugContainsType(WildcardType t, Type s) { 1625 // System.err.println(); 1626 // System.err.format(" does %s contain %s?%n", t, s); 1627 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n", 1628 // wildUpperBound(s), s, t, wildUpperBound(t), 1629 // t.isSuperBound() 1630 // || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t))); 1631 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n", 1632 // wildLowerBound(t), t, s, wildLowerBound(s), 1633 // t.isExtendsBound() 1634 // || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))); 1635 // System.err.println(); 1636 // } 1637 1638 @Override 1639 public Boolean visitWildcardType(WildcardType t, Type s) { 1640 if (s.isPartial()) 1641 return containedBy(s, t); 1642 else { 1643 // debugContainsType(t, s); 1644 1645 // ----------------------------------- Unspecified behavior ---------------- 1646 1647 /* If a primitive class V implements an interface I, then does "? extends I" contain V? 1648 It seems widening must be applied here to answer yes to compile some common code 1649 patterns. 1650 */ 1651 1652 // --------------------------------------------------------------------------- 1653 return isSameWildcard(t, s) 1654 || isCaptureOf(s, t) 1655 || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) && 1656 (t.isSuperBound() || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t)))); 1657 } 1658 } 1659 1660 @Override 1661 public Boolean visitUndetVar(UndetVar t, Type s) { 1662 if (!s.hasTag(WILDCARD)) { 1663 return isSameType(t, s); 1664 } else { 1665 return false; 1666 } 1667 } 1668 1669 @Override 1670 public Boolean visitErrorType(ErrorType t, Type s) { 1671 return true; 1672 } 1673 }; 1674 1675 public boolean isCaptureOf(Type s, WildcardType t) { 1676 if (!s.hasTag(TYPEVAR) || !((TypeVar)s).isCaptured()) 1677 return false; 1678 return isSameWildcard(t, ((CapturedType)s).wildcard); 1679 } 1680 1681 public boolean isSameWildcard(WildcardType t, Type s) { 1682 if (!s.hasTag(WILDCARD)) 1683 return false; 1684 WildcardType w = (WildcardType)s; 1685 return w.kind == t.kind && w.type == t.type; 1686 } 1687 1688 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) { 1689 while (ts.nonEmpty() && ss.nonEmpty() 1690 && containsTypeEquivalent(ts.head, ss.head)) { 1691 ts = ts.tail; 1692 ss = ss.tail; 1693 } 1694 return ts.isEmpty() && ss.isEmpty(); 1695 } 1696 // </editor-fold> 1697 1698 // <editor-fold defaultstate="collapsed" desc="isCastable"> 1699 public boolean isCastable(Type t, Type s) { 1700 return isCastable(t, s, noWarnings); 1701 } 1702 1703 /** 1704 * Is t castable to s?<br> 1705 * s is assumed to be an erased type.<br> 1706 * (not defined for Method and ForAll types). 1707 */ 1708 public boolean isCastable(Type t, Type s, Warner warn) { 1709 // if same type 1710 if (t == s) 1711 return true; 1712 // if one of the types is primitive 1713 if (t.isPrimitive() != s.isPrimitive()) { 1714 t = skipTypeVars(t, false); 1715 return (isConvertible(t, s, warn) 1716 || (s.isPrimitive() && 1717 isSubtype(boxedClass(s).type, t))); 1718 } 1719 boolean result; 1720 if (warn != warnStack.head) { 1721 try { 1722 warnStack = warnStack.prepend(warn); 1723 checkUnsafeVarargsConversion(t, s, warn); 1724 result = isCastable.visit(t,s); 1725 } finally { 1726 warnStack = warnStack.tail; 1727 } 1728 } else { 1729 result = isCastable.visit(t,s); 1730 } 1731 if (result && t.hasTag(CLASS) && t.tsym.kind.matches(Kinds.KindSelector.TYP) 1732 && s.hasTag(CLASS) && s.tsym.kind.matches(Kinds.KindSelector.TYP) 1733 && (t.tsym.isSealed() || s.tsym.isSealed())) { 1734 return (t.isCompound() || s.isCompound()) ? 1735 true : 1736 !areDisjoint((ClassSymbol)t.tsym, (ClassSymbol)s.tsym); 1737 } 1738 return result; 1739 } 1740 // where 1741 private boolean areDisjoint(ClassSymbol ts, ClassSymbol ss) { 1742 if (isSubtype(erasure(ts.type.referenceProjectionOrSelf()), erasure(ss.type))) { 1743 return false; 1744 } 1745 // if both are classes or both are interfaces, shortcut 1746 if (ts.isInterface() == ss.isInterface() && isSubtype(erasure(ss.type), erasure(ts.type))) { 1747 return false; 1748 } 1749 if (ts.isInterface() && !ss.isInterface()) { 1750 /* so ts is interface but ss is a class 1751 * an interface is disjoint from a class if the class is disjoint form the interface 1752 */ 1753 return areDisjoint(ss, ts); 1754 } 1755 // a final class that is not subtype of ss is disjoint 1756 if (!ts.isInterface() && ts.isFinal()) { 1757 return true; 1758 } 1759 // if at least one is sealed 1760 if (ts.isSealed() || ss.isSealed()) { 1761 // permitted subtypes have to be disjoint with the other symbol 1762 ClassSymbol sealedOne = ts.isSealed() ? ts : ss; 1763 ClassSymbol other = sealedOne == ts ? ss : ts; 1764 return sealedOne.permitted.stream().allMatch(sym -> areDisjoint((ClassSymbol)sym, other)); 1765 } 1766 return false; 1767 } 1768 1769 private TypeRelation isCastable = new TypeRelation() { 1770 1771 public Boolean visitType(Type t, Type s) { 1772 if (s.hasTag(ERROR) || t.hasTag(NONE)) 1773 return true; 1774 1775 switch (t.getTag()) { 1776 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: 1777 case DOUBLE: 1778 return s.isNumeric(); 1779 case BOOLEAN: 1780 return s.hasTag(BOOLEAN); 1781 case VOID: 1782 return false; 1783 case BOT: 1784 return isSubtype(t, s); 1785 default: 1786 throw new AssertionError(); 1787 } 1788 } 1789 1790 @Override 1791 public Boolean visitWildcardType(WildcardType t, Type s) { 1792 return isCastable(wildUpperBound(t), s, warnStack.head); 1793 } 1794 1795 @Override 1796 public Boolean visitClassType(ClassType t, Type s) { 1797 if (s.hasTag(ERROR) || (s.hasTag(BOT) && (!allowPrimitiveClasses || !t.isPrimitiveClass()))) 1798 return true; 1799 1800 if (s.hasTag(TYPEVAR)) { 1801 if (isCastable(t, s.getUpperBound(), noWarnings)) { 1802 warnStack.head.warn(LintCategory.UNCHECKED); 1803 return true; 1804 } else { 1805 return false; 1806 } 1807 } 1808 1809 if (t.isCompound() || s.isCompound()) { 1810 return !t.isCompound() ? 1811 visitCompoundType((ClassType)s, t, true) : 1812 visitCompoundType(t, s, false); 1813 } 1814 1815 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) { 1816 if (allowPrimitiveClasses) { 1817 if (t.isPrimitiveClass()) { 1818 // (s) Value ? == (s) Value.ref 1819 t = t.referenceProjection(); 1820 } 1821 if (s.isPrimitiveClass()) { 1822 // (Value) t ? == (Value.ref) t 1823 s = s.referenceProjection(); 1824 } 1825 } 1826 boolean upcast; 1827 if ((upcast = isSubtype(erasure(t), erasure(s))) 1828 || isSubtype(erasure(s), erasure(t))) { 1829 if (!upcast && s.hasTag(ARRAY)) { 1830 if (!isReifiable(s)) 1831 warnStack.head.warn(LintCategory.UNCHECKED); 1832 return true; 1833 } else if (s.isRaw()) { 1834 return true; 1835 } else if (t.isRaw()) { 1836 if (!isUnbounded(s)) 1837 warnStack.head.warn(LintCategory.UNCHECKED); 1838 return true; 1839 } 1840 // Assume |a| <: |b| 1841 final Type a = upcast ? t : s; 1842 final Type b = upcast ? s : t; 1843 final boolean HIGH = true; 1844 final boolean LOW = false; 1845 final boolean DONT_REWRITE_TYPEVARS = false; 1846 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS); 1847 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS); 1848 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS); 1849 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS); 1850 Type lowSub = asSub(bLow, aLow.tsym); 1851 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); 1852 if (highSub == null) { 1853 final boolean REWRITE_TYPEVARS = true; 1854 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS); 1855 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS); 1856 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS); 1857 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS); 1858 lowSub = asSub(bLow, aLow.tsym); 1859 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); 1860 } 1861 if (highSub != null) { 1862 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) { 1863 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym); 1864 } 1865 if (!disjointTypes(aHigh.allparams(), highSub.allparams()) 1866 && !disjointTypes(aHigh.allparams(), lowSub.allparams()) 1867 && !disjointTypes(aLow.allparams(), highSub.allparams()) 1868 && !disjointTypes(aLow.allparams(), lowSub.allparams())) { 1869 if (upcast ? giveWarning(a, b) : 1870 giveWarning(b, a)) 1871 warnStack.head.warn(LintCategory.UNCHECKED); 1872 return true; 1873 } 1874 } 1875 if (isReifiable(s)) 1876 return isSubtypeUnchecked(a, b); 1877 else 1878 return isSubtypeUnchecked(a, b, warnStack.head); 1879 } 1880 1881 // Sidecast 1882 if (s.hasTag(CLASS)) { 1883 if ((s.tsym.flags() & INTERFACE) != 0) { 1884 return ((t.tsym.flags() & FINAL) == 0) 1885 ? sideCast(t, s, warnStack.head) 1886 : sideCastFinal(t, s, warnStack.head); 1887 } else if ((t.tsym.flags() & INTERFACE) != 0) { 1888 return ((s.tsym.flags() & FINAL) == 0) 1889 ? sideCast(t, s, warnStack.head) 1890 : sideCastFinal(t, s, warnStack.head); 1891 } else { 1892 // unrelated class types 1893 return false; 1894 } 1895 } 1896 } 1897 return false; 1898 } 1899 1900 boolean visitCompoundType(ClassType ct, Type s, boolean reverse) { 1901 Warner warn = noWarnings; 1902 for (Type c : directSupertypes(ct)) { 1903 warn.clear(); 1904 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn)) 1905 return false; 1906 } 1907 if (warn.hasLint(LintCategory.UNCHECKED)) 1908 warnStack.head.warn(LintCategory.UNCHECKED); 1909 return true; 1910 } 1911 1912 @Override 1913 public Boolean visitArrayType(ArrayType t, Type s) { 1914 switch (s.getTag()) { 1915 case ERROR: 1916 case BOT: 1917 return true; 1918 case TYPEVAR: 1919 if (isCastable(s, t, noWarnings)) { 1920 warnStack.head.warn(LintCategory.UNCHECKED); 1921 return true; 1922 } else { 1923 return false; 1924 } 1925 case CLASS: 1926 return isSubtype(t, s); 1927 case ARRAY: 1928 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) { 1929 return elemtype(t).hasTag(elemtype(s).getTag()); 1930 } else { 1931 return isCastable(elemtype(t), elemtype(s), warnStack.head); 1932 } 1933 default: 1934 return false; 1935 } 1936 } 1937 1938 @Override 1939 public Boolean visitTypeVar(TypeVar t, Type s) { 1940 switch (s.getTag()) { 1941 case ERROR: 1942 case BOT: 1943 return true; 1944 case TYPEVAR: 1945 if (isSubtype(t, s)) { 1946 return true; 1947 } else if (isCastable(t.getUpperBound(), s, noWarnings)) { 1948 warnStack.head.warn(LintCategory.UNCHECKED); 1949 return true; 1950 } else { 1951 return false; 1952 } 1953 default: 1954 return isCastable(t.getUpperBound(), s, warnStack.head); 1955 } 1956 } 1957 1958 @Override 1959 public Boolean visitErrorType(ErrorType t, Type s) { 1960 return true; 1961 } 1962 }; 1963 // </editor-fold> 1964 1965 // <editor-fold defaultstate="collapsed" desc="disjointTypes"> 1966 public boolean disjointTypes(List<Type> ts, List<Type> ss) { 1967 while (ts.tail != null && ss.tail != null) { 1968 if (disjointType(ts.head, ss.head)) return true; 1969 ts = ts.tail; 1970 ss = ss.tail; 1971 } 1972 return false; 1973 } 1974 1975 /** 1976 * Two types or wildcards are considered disjoint if it can be 1977 * proven that no type can be contained in both. It is 1978 * conservative in that it is allowed to say that two types are 1979 * not disjoint, even though they actually are. 1980 * 1981 * The type {@code C<X>} is castable to {@code C<Y>} exactly if 1982 * {@code X} and {@code Y} are not disjoint. 1983 */ 1984 public boolean disjointType(Type t, Type s) { 1985 return disjointType.visit(t, s); 1986 } 1987 // where 1988 private TypeRelation disjointType = new TypeRelation() { 1989 1990 private Set<TypePair> cache = new HashSet<>(); 1991 1992 @Override 1993 public Boolean visitType(Type t, Type s) { 1994 if (s.hasTag(WILDCARD)) 1995 return visit(s, t); 1996 else 1997 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t); 1998 } 1999 2000 private boolean isCastableRecursive(Type t, Type s) { 2001 TypePair pair = new TypePair(t, s); 2002 if (cache.add(pair)) { 2003 try { 2004 return Types.this.isCastable(t, s); 2005 } finally { 2006 cache.remove(pair); 2007 } 2008 } else { 2009 return true; 2010 } 2011 } 2012 2013 private boolean notSoftSubtypeRecursive(Type t, Type s) { 2014 TypePair pair = new TypePair(t, s); 2015 if (cache.add(pair)) { 2016 try { 2017 return Types.this.notSoftSubtype(t, s); 2018 } finally { 2019 cache.remove(pair); 2020 } 2021 } else { 2022 return false; 2023 } 2024 } 2025 2026 @Override 2027 public Boolean visitWildcardType(WildcardType t, Type s) { 2028 if (t.isUnbound()) 2029 return false; 2030 2031 if (!s.hasTag(WILDCARD)) { 2032 if (t.isExtendsBound()) 2033 return notSoftSubtypeRecursive(s, t.type); 2034 else 2035 return notSoftSubtypeRecursive(t.type, s); 2036 } 2037 2038 if (s.isUnbound()) 2039 return false; 2040 2041 if (t.isExtendsBound()) { 2042 if (s.isExtendsBound()) 2043 return !isCastableRecursive(t.type, wildUpperBound(s)); 2044 else if (s.isSuperBound()) 2045 return notSoftSubtypeRecursive(wildLowerBound(s), t.type); 2046 } else if (t.isSuperBound()) { 2047 if (s.isExtendsBound()) 2048 return notSoftSubtypeRecursive(t.type, wildUpperBound(s)); 2049 } 2050 return false; 2051 } 2052 }; 2053 // </editor-fold> 2054 2055 // <editor-fold defaultstate="collapsed" desc="cvarLowerBounds"> 2056 public List<Type> cvarLowerBounds(List<Type> ts) { 2057 return ts.map(cvarLowerBoundMapping); 2058 } 2059 private final TypeMapping<Void> cvarLowerBoundMapping = new TypeMapping<Void>() { 2060 @Override 2061 public Type visitCapturedType(CapturedType t, Void _unused) { 2062 return cvarLowerBound(t); 2063 } 2064 }; 2065 // </editor-fold> 2066 2067 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype"> 2068 /** 2069 * This relation answers the question: is impossible that 2070 * something of type `t' can be a subtype of `s'? This is 2071 * different from the question "is `t' not a subtype of `s'?" 2072 * when type variables are involved: Integer is not a subtype of T 2073 * where {@code <T extends Number>} but it is not true that Integer cannot 2074 * possibly be a subtype of T. 2075 */ 2076 public boolean notSoftSubtype(Type t, Type s) { 2077 if (t == s) return false; 2078 if (t.hasTag(TYPEVAR)) { 2079 TypeVar tv = (TypeVar) t; 2080 return !isCastable(tv.getUpperBound(), 2081 relaxBound(s), 2082 noWarnings); 2083 } 2084 if (!s.hasTag(WILDCARD)) 2085 s = cvarUpperBound(s); 2086 2087 return !isSubtype(t, relaxBound(s)); 2088 } 2089 2090 private Type relaxBound(Type t) { 2091 return (t.hasTag(TYPEVAR)) ? 2092 rewriteQuantifiers(skipTypeVars(t, false), true, true) : 2093 t; 2094 } 2095 // </editor-fold> 2096 2097 // <editor-fold defaultstate="collapsed" desc="isReifiable"> 2098 public boolean isReifiable(Type t) { 2099 return isReifiable.visit(t); 2100 } 2101 // where 2102 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() { 2103 2104 public Boolean visitType(Type t, Void ignored) { 2105 return true; 2106 } 2107 2108 @Override 2109 public Boolean visitClassType(ClassType t, Void ignored) { 2110 if (t.isCompound()) 2111 return false; 2112 else { 2113 if (!t.isParameterized()) 2114 return true; 2115 2116 for (Type param : t.allparams()) { 2117 if (!param.isUnbound()) 2118 return false; 2119 } 2120 return true; 2121 } 2122 } 2123 2124 @Override 2125 public Boolean visitArrayType(ArrayType t, Void ignored) { 2126 return visit(t.elemtype); 2127 } 2128 2129 @Override 2130 public Boolean visitTypeVar(TypeVar t, Void ignored) { 2131 return false; 2132 } 2133 }; 2134 // </editor-fold> 2135 2136 // <editor-fold defaultstate="collapsed" desc="Array Utils"> 2137 public boolean isArray(Type t) { 2138 while (t.hasTag(WILDCARD)) 2139 t = wildUpperBound(t); 2140 return t.hasTag(ARRAY); 2141 } 2142 2143 /** 2144 * The element type of an array. 2145 */ 2146 public Type elemtype(Type t) { 2147 switch (t.getTag()) { 2148 case WILDCARD: 2149 return elemtype(wildUpperBound(t)); 2150 case ARRAY: 2151 return ((ArrayType)t).elemtype; 2152 case FORALL: 2153 return elemtype(((ForAll)t).qtype); 2154 case ERROR: 2155 return t; 2156 default: 2157 return null; 2158 } 2159 } 2160 2161 public Type elemtypeOrType(Type t) { 2162 Type elemtype = elemtype(t); 2163 return elemtype != null ? 2164 elemtype : 2165 t; 2166 } 2167 2168 /** 2169 * Mapping to take element type of an arraytype 2170 */ 2171 private TypeMapping<Void> elemTypeFun = new TypeMapping<Void>() { 2172 @Override 2173 public Type visitArrayType(ArrayType t, Void _unused) { 2174 return t.elemtype; 2175 } 2176 2177 @Override 2178 public Type visitTypeVar(TypeVar t, Void _unused) { 2179 return visit(skipTypeVars(t, false)); 2180 } 2181 }; 2182 2183 /** 2184 * The number of dimensions of an array type. 2185 */ 2186 public int dimensions(Type t) { 2187 int result = 0; 2188 while (t.hasTag(ARRAY)) { 2189 result++; 2190 t = elemtype(t); 2191 } 2192 return result; 2193 } 2194 2195 /** 2196 * Returns an ArrayType with the component type t 2197 * 2198 * @param t The component type of the ArrayType 2199 * @return the ArrayType for the given component 2200 */ 2201 public ArrayType makeArrayType(Type t) { 2202 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) { 2203 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString()); 2204 } 2205 return new ArrayType(t, syms.arrayClass); 2206 } 2207 // </editor-fold> 2208 2209 // <editor-fold defaultstate="collapsed" desc="asSuper"> 2210 /** 2211 * Return the (most specific) base type of t that starts with the 2212 * given symbol. If none exists, return null. 2213 * 2214 * Caveat Emptor: Since javac represents the class of all arrays with a singleton 2215 * symbol Symtab.arrayClass, which by being a singleton cannot hold any discriminant, 2216 * this method could yield surprising answers when invoked on arrays. For example when 2217 * invoked with t being byte [] and sym being t.sym itself, asSuper would answer null. 2218 * 2219 * Further caveats in Valhalla: There are two "hazards" we need to watch out for when using 2220 * this method. 2221 * 2222 * 1. Since Foo.ref and Foo.val share the same symbol, that of Foo.class, a call to 2223 * asSuper(Foo.ref.type, Foo.val.type.tsym) would return non-null. This MAY NOT BE correct 2224 * depending on the call site. Foo.val is NOT a super type of Foo.ref either in the language 2225 * model or in the VM's world view. An example of such an hazardous call used to exist in 2226 * Gen.visitTypeCast. When we emit code for (Foo) Foo.ref.instance a check for whether we 2227 * really need the cast cannot/shouldn't be gated on 2228 * 2229 * asSuper(tree.expr.type, tree.clazz.type.tsym) == null) 2230 * 2231 * but use !types.isSubtype(tree.expr.type, tree.clazz.type) which operates in terms of 2232 * types. When we operate in terms of symbols, there is a loss of type information leading 2233 * to a hazard. Whether a call to asSuper should be transformed into a isSubtype call is 2234 * tricky. isSubtype returns just a boolean while asSuper returns richer information which 2235 * may be required at the call site. Also where the concerned symbol corresponds to a 2236 * generic class, an asSuper call cannot be conveniently rewritten as an isSubtype call 2237 * (see that asSuper(ArrayList<String>.type, List<T>.tsym) != null while 2238 * isSubType(ArrayList<String>.type, List<T>.type) is false;) So care needs to be exercised. 2239 * 2240 * 2. Given a primitive class Foo, a call to asSuper(Foo.type, SuperclassOfFoo.tsym) and/or 2241 * a call to asSuper(Foo.type, SuperinterfaceOfFoo.tsym) would answer null. In many places 2242 * that is NOT what we want. An example of such a hazardous call used to occur in 2243 * Attr.visitForeachLoop when checking to make sure the for loop's control variable of a type 2244 * that implements Iterable: viz: types.asSuper(exprType, syms.iterableType.tsym); 2245 * These hazardous calls should be rewritten as 2246 * types.asSuper(exprType.referenceProjectionOrSelf(), syms.iterableType.tsym); instead. 2247 * 2248 * @param t a type 2249 * @param sym a symbol 2250 */ 2251 public Type asSuper(Type t, Symbol sym) { 2252 /* Some examples: 2253 * 2254 * (Enum<E>, Comparable) => Comparable<E> 2255 * (c.s.s.d.AttributeTree.ValueKind, Enum) => Enum<c.s.s.d.AttributeTree.ValueKind> 2256 * (c.s.s.t.ExpressionTree, c.s.s.t.Tree) => c.s.s.t.Tree 2257 * (j.u.List<capture#160 of ? extends c.s.s.d.DocTree>, Iterable) => 2258 * Iterable<capture#160 of ? extends c.s.s.d.DocTree> 2259 */ 2260 2261 if (allowPrimitiveClasses && t.isPrimitiveClass()) { 2262 // No man may be an island, but the bell tolls for a value. 2263 return t.tsym == sym ? t : null; 2264 } 2265 2266 if (sym.type == syms.objectType) { //optimization 2267 return syms.objectType; 2268 } 2269 return asSuper.visit(t, sym); 2270 } 2271 // where 2272 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() { 2273 2274 private Set<Symbol> seenTypes = new HashSet<>(); 2275 2276 public Type visitType(Type t, Symbol sym) { 2277 return null; 2278 } 2279 2280 @Override 2281 public Type visitClassType(ClassType t, Symbol sym) { 2282 if (t.tsym == sym) 2283 return t; 2284 2285 Symbol c = t.tsym; 2286 if (!seenTypes.add(c)) { 2287 return null; 2288 } 2289 try { 2290 Type st = supertype(t); 2291 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) { 2292 Type x = asSuper(st, sym); 2293 if (x != null) 2294 return x; 2295 } 2296 if ((sym.flags() & INTERFACE) != 0) { 2297 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { 2298 if (!l.head.hasTag(ERROR)) { 2299 Type x = asSuper(l.head, sym); 2300 if (x != null) 2301 return x; 2302 } 2303 } 2304 } 2305 return null; 2306 } finally { 2307 seenTypes.remove(c); 2308 } 2309 } 2310 2311 @Override 2312 public Type visitArrayType(ArrayType t, Symbol sym) { 2313 return isSubtype(t, sym.type) ? sym.type : null; 2314 } 2315 2316 @Override 2317 public Type visitTypeVar(TypeVar t, Symbol sym) { 2318 if (t.tsym == sym) 2319 return t; 2320 else 2321 return asSuper(t.getUpperBound(), sym); 2322 } 2323 2324 @Override 2325 public Type visitErrorType(ErrorType t, Symbol sym) { 2326 return t; 2327 } 2328 }; 2329 2330 /** 2331 * Return the base type of t or any of its outer types that starts 2332 * with the given symbol. If none exists, return null. 2333 * 2334 * @param t a type 2335 * @param sym a symbol 2336 */ 2337 public Type asOuterSuper(Type t, Symbol sym) { 2338 switch (t.getTag()) { 2339 case CLASS: 2340 do { 2341 Type s = asSuper(t, sym); 2342 if (s != null) return s; 2343 t = t.getEnclosingType(); 2344 } while (t.hasTag(CLASS)); 2345 return null; 2346 case ARRAY: 2347 return isSubtype(t, sym.type) ? sym.type : null; 2348 case TYPEVAR: 2349 return asSuper(t, sym); 2350 case ERROR: 2351 return t; 2352 default: 2353 return null; 2354 } 2355 } 2356 2357 /** 2358 * Return the base type of t or any of its enclosing types that 2359 * starts with the given symbol. If none exists, return null. 2360 * 2361 * @param t a type 2362 * @param sym a symbol 2363 */ 2364 public Type asEnclosingSuper(Type t, Symbol sym) { 2365 switch (t.getTag()) { 2366 case CLASS: 2367 do { 2368 Type s = asSuper(t, sym); 2369 if (s != null) return s; 2370 Type outer = t.getEnclosingType(); 2371 t = (outer.hasTag(CLASS)) ? outer : 2372 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type : 2373 Type.noType; 2374 } while (t.hasTag(CLASS)); 2375 return null; 2376 case ARRAY: 2377 return isSubtype(t, sym.type) ? sym.type : null; 2378 case TYPEVAR: 2379 return asSuper(t, sym); 2380 case ERROR: 2381 return t; 2382 default: 2383 return null; 2384 } 2385 } 2386 // </editor-fold> 2387 2388 // <editor-fold defaultstate="collapsed" desc="memberType"> 2389 /** 2390 * The type of given symbol, seen as a member of t. 2391 * 2392 * @param t a type 2393 * @param sym a symbol 2394 */ 2395 public Type memberType(Type t, Symbol sym) { 2396 2397 if ((sym.flags() & STATIC) != 0) 2398 return sym.type; 2399 2400 /* If any primitive class types are involved, switch over to the reference universe, 2401 where the hierarchy is navigable. V and V.ref have identical membership 2402 with no bridging needs. 2403 */ 2404 if (allowPrimitiveClasses && t.isPrimitiveClass()) 2405 t = t.referenceProjection(); 2406 2407 return memberType.visit(t, sym); 2408 } 2409 // where 2410 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() { 2411 2412 public Type visitType(Type t, Symbol sym) { 2413 return sym.type; 2414 } 2415 2416 @Override 2417 public Type visitWildcardType(WildcardType t, Symbol sym) { 2418 return memberType(wildUpperBound(t), sym); 2419 } 2420 2421 @Override 2422 public Type visitClassType(ClassType t, Symbol sym) { 2423 Symbol owner = sym.owner; 2424 long flags = sym.flags(); 2425 if (((flags & STATIC) == 0) && owner.type.isParameterized()) { 2426 Type base = asOuterSuper(t, owner); 2427 //if t is an intersection type T = CT & I1 & I2 ... & In 2428 //its supertypes CT, I1, ... In might contain wildcards 2429 //so we need to go through capture conversion 2430 base = t.isCompound() ? capture(base) : base; 2431 if (base != null) { 2432 List<Type> ownerParams = owner.type.allparams(); 2433 List<Type> baseParams = base.allparams(); 2434 if (ownerParams.nonEmpty()) { 2435 if (baseParams.isEmpty()) { 2436 // then base is a raw type 2437 return erasure(sym.type); 2438 } else { 2439 return subst(sym.type, ownerParams, baseParams); 2440 } 2441 } 2442 } 2443 } 2444 return sym.type; 2445 } 2446 2447 @Override 2448 public Type visitTypeVar(TypeVar t, Symbol sym) { 2449 return memberType(t.getUpperBound(), sym); 2450 } 2451 2452 @Override 2453 public Type visitErrorType(ErrorType t, Symbol sym) { 2454 return t; 2455 } 2456 }; 2457 // </editor-fold> 2458 2459 // <editor-fold defaultstate="collapsed" desc="isAssignable"> 2460 public boolean isAssignable(Type t, Type s) { 2461 return isAssignable(t, s, noWarnings); 2462 } 2463 2464 /** 2465 * Is t assignable to s?<br> 2466 * Equivalent to subtype except for constant values and raw 2467 * types.<br> 2468 * (not defined for Method and ForAll types) 2469 */ 2470 public boolean isAssignable(Type t, Type s, Warner warn) { 2471 if (t.hasTag(ERROR)) 2472 return true; 2473 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) { 2474 int value = ((Number)t.constValue()).intValue(); 2475 switch (s.getTag()) { 2476 case BYTE: 2477 case CHAR: 2478 case SHORT: 2479 case INT: 2480 if (s.getTag().checkRange(value)) 2481 return true; 2482 break; 2483 case CLASS: 2484 switch (unboxedType(s).getTag()) { 2485 case BYTE: 2486 case CHAR: 2487 case SHORT: 2488 return isAssignable(t, unboxedType(s), warn); 2489 } 2490 break; 2491 } 2492 } 2493 return isConvertible(t, s, warn); 2494 } 2495 // </editor-fold> 2496 2497 // <editor-fold defaultstate="collapsed" desc="erasure"> 2498 /** 2499 * The erasure of t {@code |t|} -- the type that results when all 2500 * type parameters in t are deleted. 2501 */ 2502 public Type erasure(Type t) { 2503 return eraseNotNeeded(t) ? t : erasure(t, false); 2504 } 2505 //where 2506 private boolean eraseNotNeeded(Type t) { 2507 // We don't want to erase primitive types and String type as that 2508 // operation is idempotent. Also, erasing these could result in loss 2509 // of information such as constant values attached to such types. 2510 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym); 2511 } 2512 2513 private Type erasure(Type t, boolean recurse) { 2514 if (t.isPrimitive()) { 2515 return t; /* fast special case */ 2516 } else { 2517 Type out = erasure.visit(t, recurse); 2518 return out; 2519 } 2520 } 2521 // where 2522 private TypeMapping<Boolean> erasure = new StructuralTypeMapping<Boolean>() { 2523 private Type combineMetadata(final Type s, 2524 final Type t) { 2525 if (t.getMetadata() != TypeMetadata.EMPTY) { 2526 switch (s.getKind()) { 2527 case OTHER: 2528 case UNION: 2529 case INTERSECTION: 2530 case PACKAGE: 2531 case EXECUTABLE: 2532 case NONE: 2533 case VOID: 2534 case ERROR: 2535 return s; 2536 default: return s.cloneWithMetadata(s.getMetadata().without(Kind.ANNOTATIONS)); 2537 } 2538 } else { 2539 return s; 2540 } 2541 } 2542 2543 public Type visitType(Type t, Boolean recurse) { 2544 if (t.isPrimitive()) 2545 return t; /*fast special case*/ 2546 else { 2547 //other cases already handled 2548 return combineMetadata(t, t); 2549 } 2550 } 2551 2552 @Override 2553 public Type visitWildcardType(WildcardType t, Boolean recurse) { 2554 Type erased = erasure(wildUpperBound(t), recurse); 2555 return combineMetadata(erased, t); 2556 } 2557 2558 @Override 2559 public Type visitClassType(ClassType t, Boolean recurse) { 2560 // erasure(projection(primitive)) = projection(erasure(primitive)) 2561 Type erased = eraseClassType(t, recurse); 2562 if (erased.hasTag(CLASS) && t.flavor != erased.getFlavor()) { 2563 erased = new ClassType(erased.getEnclosingType(), 2564 List.nil(), erased.tsym, 2565 erased.getMetadata(), t.flavor); 2566 } 2567 return erased; 2568 } 2569 // where 2570 private Type eraseClassType(ClassType t, Boolean recurse) { 2571 Type erased = t.tsym.erasure(Types.this); 2572 if (recurse) { 2573 erased = new ErasedClassType(erased.getEnclosingType(), erased.tsym, 2574 t.getMetadata().without(Kind.ANNOTATIONS)); 2575 return erased; 2576 } else { 2577 return combineMetadata(erased, t); 2578 } 2579 } 2580 2581 @Override 2582 public Type visitTypeVar(TypeVar t, Boolean recurse) { 2583 Type erased = erasure(t.getUpperBound(), recurse); 2584 return combineMetadata(erased, t); 2585 } 2586 }; 2587 2588 public List<Type> erasure(List<Type> ts) { 2589 return erasure.visit(ts, false); 2590 } 2591 2592 public Type erasureRecursive(Type t) { 2593 return erasure(t, true); 2594 } 2595 2596 public List<Type> erasureRecursive(List<Type> ts) { 2597 return erasure.visit(ts, true); 2598 } 2599 // </editor-fold> 2600 2601 // <editor-fold defaultstate="collapsed" desc="makeIntersectionType"> 2602 /** 2603 * Make an intersection type from non-empty list of types. The list should be ordered according to 2604 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. Note that this might cause a symbol completion. 2605 * Hence, this version of makeIntersectionType may not be called during a classfile read. 2606 * 2607 * @param bounds the types from which the intersection type is formed 2608 */ 2609 public IntersectionClassType makeIntersectionType(List<Type> bounds) { 2610 return makeIntersectionType(bounds, bounds.head.tsym.isInterface()); 2611 } 2612 2613 /** 2614 * Make an intersection type from non-empty list of types. The list should be ordered according to 2615 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. This does not cause symbol completion as 2616 * an extra parameter indicates as to whether all bounds are interfaces - in which case the 2617 * supertype is implicitly assumed to be 'Object'. 2618 * 2619 * @param bounds the types from which the intersection type is formed 2620 * @param allInterfaces are all bounds interface types? 2621 */ 2622 public IntersectionClassType makeIntersectionType(List<Type> bounds, boolean allInterfaces) { 2623 Assert.check(bounds.nonEmpty()); 2624 Type firstExplicitBound = bounds.head; 2625 if (allInterfaces) { 2626 bounds = bounds.prepend(syms.objectType); 2627 } 2628 ClassSymbol bc = 2629 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC, 2630 Type.moreInfo 2631 ? names.fromString(bounds.toString()) 2632 : names.empty, 2633 null, 2634 syms.noSymbol); 2635 IntersectionClassType intersectionType = new IntersectionClassType(bounds, bc, allInterfaces); 2636 bc.type = intersectionType; 2637 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ? 2638 syms.objectType : // error condition, recover 2639 erasure(firstExplicitBound); 2640 bc.members_field = WriteableScope.create(bc); 2641 return intersectionType; 2642 } 2643 // </editor-fold> 2644 2645 // <editor-fold defaultstate="collapsed" desc="supertype"> 2646 public Type supertype(Type t) { 2647 return supertype.visit(t); 2648 } 2649 // where 2650 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() { 2651 2652 public Type visitType(Type t, Void ignored) { 2653 // A note on wildcards: there is no good way to 2654 // determine a supertype for a lower-bounded wildcard. 2655 return Type.noType; 2656 } 2657 2658 @Override 2659 public Type visitClassType(ClassType t, Void ignored) { 2660 if (t.supertype_field == null) { 2661 Type supertype = ((ClassSymbol)t.tsym).getSuperclass(); 2662 // An interface has no superclass; its supertype is Object. 2663 if (t.isInterface()) 2664 supertype = ((ClassType)t.tsym.type).supertype_field; 2665 if (t.supertype_field == null) { 2666 List<Type> actuals = classBound(t).allparams(); 2667 List<Type> formals = t.tsym.type.allparams(); 2668 if (t.hasErasedSupertypes()) { 2669 t.supertype_field = erasureRecursive(supertype); 2670 } else if (formals.nonEmpty()) { 2671 t.supertype_field = subst(supertype, formals, actuals); 2672 } 2673 else { 2674 t.supertype_field = supertype; 2675 } 2676 } 2677 } 2678 return t.supertype_field; 2679 } 2680 2681 /** 2682 * The supertype is always a class type. If the type 2683 * variable's bounds start with a class type, this is also 2684 * the supertype. Otherwise, the supertype is 2685 * java.lang.Object. 2686 */ 2687 @Override 2688 public Type visitTypeVar(TypeVar t, Void ignored) { 2689 if (t.getUpperBound().hasTag(TYPEVAR) || 2690 (!t.getUpperBound().isCompound() && !t.getUpperBound().isInterface())) { 2691 return t.getUpperBound(); 2692 } else { 2693 return supertype(t.getUpperBound()); 2694 } 2695 } 2696 2697 @Override 2698 public Type visitArrayType(ArrayType t, Void ignored) { 2699 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType)) 2700 return arraySuperType(); 2701 else 2702 return new ArrayType(supertype(t.elemtype), t.tsym); 2703 } 2704 2705 @Override 2706 public Type visitErrorType(ErrorType t, Void ignored) { 2707 return Type.noType; 2708 } 2709 }; 2710 // </editor-fold> 2711 2712 // <editor-fold defaultstate="collapsed" desc="interfaces"> 2713 /** 2714 * Return the interfaces implemented by this class. 2715 */ 2716 public List<Type> interfaces(Type t) { 2717 return interfaces.visit(t); 2718 } 2719 // where 2720 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() { 2721 2722 public List<Type> visitType(Type t, Void ignored) { 2723 return List.nil(); 2724 } 2725 2726 @Override 2727 public List<Type> visitClassType(ClassType t, Void ignored) { 2728 if (t.interfaces_field == null) { 2729 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces(); 2730 if (t.interfaces_field == null) { 2731 // If t.interfaces_field is null, then t must 2732 // be a parameterized type (not to be confused 2733 // with a generic type declaration). 2734 // Terminology: 2735 // Parameterized type: List<String> 2736 // Generic type declaration: class List<E> { ... } 2737 // So t corresponds to List<String> and 2738 // t.tsym.type corresponds to List<E>. 2739 // The reason t must be parameterized type is 2740 // that completion will happen as a side 2741 // effect of calling 2742 // ClassSymbol.getInterfaces. Since 2743 // t.interfaces_field is null after 2744 // completion, we can assume that t is not the 2745 // type of a class/interface declaration. 2746 Assert.check(t != t.tsym.type, t); 2747 List<Type> actuals = t.allparams(); 2748 List<Type> formals = t.tsym.type.allparams(); 2749 if (t.hasErasedSupertypes()) { 2750 t.interfaces_field = erasureRecursive(interfaces); 2751 } else if (formals.nonEmpty()) { 2752 t.interfaces_field = subst(interfaces, formals, actuals); 2753 } 2754 else { 2755 t.interfaces_field = interfaces; 2756 } 2757 } 2758 } 2759 return t.interfaces_field; 2760 } 2761 2762 @Override 2763 public List<Type> visitTypeVar(TypeVar t, Void ignored) { 2764 if (t.getUpperBound().isCompound()) 2765 return interfaces(t.getUpperBound()); 2766 2767 if (t.getUpperBound().isInterface()) 2768 return List.of(t.getUpperBound()); 2769 2770 return List.nil(); 2771 } 2772 }; 2773 2774 public List<Type> directSupertypes(Type t) { 2775 return directSupertypes.visit(t); 2776 } 2777 // where 2778 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() { 2779 2780 public List<Type> visitType(final Type type, final Void ignored) { 2781 if (!type.isIntersection()) { 2782 final Type sup = supertype(type); 2783 return (sup == Type.noType || sup == type || sup == null) 2784 ? interfaces(type) 2785 : interfaces(type).prepend(sup); 2786 } else { 2787 return ((IntersectionClassType)type).getExplicitComponents(); 2788 } 2789 } 2790 }; 2791 2792 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) { 2793 for (Type i2 : interfaces(origin.type)) { 2794 if (isym == i2.tsym) return true; 2795 } 2796 return false; 2797 } 2798 // </editor-fold> 2799 2800 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw"> 2801 Map<Type,Boolean> isDerivedRawCache = new HashMap<>(); 2802 2803 public boolean isDerivedRaw(Type t) { 2804 Boolean result = isDerivedRawCache.get(t); 2805 if (result == null) { 2806 result = isDerivedRawInternal(t); 2807 isDerivedRawCache.put(t, result); 2808 } 2809 return result; 2810 } 2811 2812 public boolean isDerivedRawInternal(Type t) { 2813 if (t.isErroneous()) 2814 return false; 2815 return 2816 t.isRaw() || 2817 supertype(t) != Type.noType && isDerivedRaw(supertype(t)) || 2818 isDerivedRaw(interfaces(t)); 2819 } 2820 2821 public boolean isDerivedRaw(List<Type> ts) { 2822 List<Type> l = ts; 2823 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail; 2824 return l.nonEmpty(); 2825 } 2826 // </editor-fold> 2827 2828 // <editor-fold defaultstate="collapsed" desc="setBounds"> 2829 /** 2830 * Same as {@link Types#setBounds(TypeVar, List, boolean)}, except that third parameter is computed directly, 2831 * as follows: if all all bounds are interface types, the computed supertype is Object,otherwise 2832 * the supertype is simply left null (in this case, the supertype is assumed to be the head of 2833 * the bound list passed as second argument). Note that this check might cause a symbol completion. 2834 * Hence, this version of setBounds may not be called during a classfile read. 2835 * 2836 * @param t a type variable 2837 * @param bounds the bounds, must be nonempty 2838 */ 2839 public void setBounds(TypeVar t, List<Type> bounds) { 2840 setBounds(t, bounds, bounds.head.tsym.isInterface()); 2841 } 2842 2843 /** 2844 * Set the bounds field of the given type variable to reflect a (possibly multiple) list of bounds. 2845 * This does not cause symbol completion as an extra parameter indicates as to whether all bounds 2846 * are interfaces - in which case the supertype is implicitly assumed to be 'Object'. 2847 * 2848 * @param t a type variable 2849 * @param bounds the bounds, must be nonempty 2850 * @param allInterfaces are all bounds interface types? 2851 */ 2852 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) { 2853 t.setUpperBound( bounds.tail.isEmpty() ? 2854 bounds.head : 2855 makeIntersectionType(bounds, allInterfaces) ); 2856 t.rank_field = -1; 2857 } 2858 // </editor-fold> 2859 2860 // <editor-fold defaultstate="collapsed" desc="getBounds"> 2861 /** 2862 * Return list of bounds of the given type variable. 2863 */ 2864 public List<Type> getBounds(TypeVar t) { 2865 if (t.getUpperBound().hasTag(NONE)) 2866 return List.nil(); 2867 else if (t.getUpperBound().isErroneous() || !t.getUpperBound().isCompound()) 2868 return List.of(t.getUpperBound()); 2869 else if ((erasure(t).tsym.flags() & INTERFACE) == 0) 2870 return interfaces(t).prepend(supertype(t)); 2871 else 2872 // No superclass was given in bounds. 2873 // In this case, supertype is Object, erasure is first interface. 2874 return interfaces(t); 2875 } 2876 // </editor-fold> 2877 2878 // <editor-fold defaultstate="collapsed" desc="classBound"> 2879 /** 2880 * If the given type is a (possibly selected) type variable, 2881 * return the bounding class of this type, otherwise return the 2882 * type itself. 2883 */ 2884 public Type classBound(Type t) { 2885 return classBound.visit(t); 2886 } 2887 // where 2888 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() { 2889 2890 public Type visitType(Type t, Void ignored) { 2891 return t; 2892 } 2893 2894 @Override 2895 public Type visitClassType(ClassType t, Void ignored) { 2896 Type outer1 = classBound(t.getEnclosingType()); 2897 if (outer1 != t.getEnclosingType()) 2898 return new ClassType(outer1, t.getTypeArguments(), t.tsym, 2899 t.getMetadata(), t.getFlavor()); 2900 else 2901 return t; 2902 } 2903 2904 @Override 2905 public Type visitTypeVar(TypeVar t, Void ignored) { 2906 return classBound(supertype(t)); 2907 } 2908 2909 @Override 2910 public Type visitErrorType(ErrorType t, Void ignored) { 2911 return t; 2912 } 2913 }; 2914 // </editor-fold> 2915 2916 // <editor-fold defaultstate="collapsed" desc="subsignature / override equivalence"> 2917 /** 2918 * Returns true iff the first signature is a <em>subsignature</em> 2919 * of the other. This is <b>not</b> an equivalence 2920 * relation. 2921 * 2922 * @jls 8.4.2 Method Signature 2923 * @see #overrideEquivalent(Type t, Type s) 2924 * @param t first signature (possibly raw). 2925 * @param s second signature (could be subjected to erasure). 2926 * @return true if t is a subsignature of s. 2927 */ 2928 public boolean isSubSignature(Type t, Type s) { 2929 return hasSameArgs(t, s, true) || hasSameArgs(t, erasure(s), true); 2930 } 2931 2932 /** 2933 * Returns true iff these signatures are related by <em>override 2934 * equivalence</em>. This is the natural extension of 2935 * isSubSignature to an equivalence relation. 2936 * 2937 * @jls 8.4.2 Method Signature 2938 * @see #isSubSignature(Type t, Type s) 2939 * @param t a signature (possible raw, could be subjected to 2940 * erasure). 2941 * @param s a signature (possible raw, could be subjected to 2942 * erasure). 2943 * @return true if either argument is a subsignature of the other. 2944 */ 2945 public boolean overrideEquivalent(Type t, Type s) { 2946 return hasSameArgs(t, s) || 2947 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s); 2948 } 2949 2950 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) { 2951 for (Symbol sym : syms.objectType.tsym.members().getSymbolsByName(msym.name)) { 2952 if (msym.overrides(sym, origin, Types.this, true)) { 2953 return true; 2954 } 2955 } 2956 return false; 2957 } 2958 2959 /** 2960 * This enum defines the strategy for implementing most specific return type check 2961 * during the most specific and functional interface checks. 2962 */ 2963 public enum MostSpecificReturnCheck { 2964 /** 2965 * Return r1 is more specific than r2 if {@code r1 <: r2}. Extra care required for (i) handling 2966 * method type variables (if either method is generic) and (ii) subtyping should be replaced 2967 * by type-equivalence for primitives. This is essentially an inlined version of 2968 * {@link Types#resultSubtype(Type, Type, Warner)}, where the assignability check has been 2969 * replaced with a strict subtyping check. 2970 */ 2971 BASIC() { 2972 @Override 2973 public boolean test(Type mt1, Type mt2, Types types) { 2974 List<Type> tvars = mt1.getTypeArguments(); 2975 List<Type> svars = mt2.getTypeArguments(); 2976 Type t = mt1.getReturnType(); 2977 Type s = types.subst(mt2.getReturnType(), svars, tvars); 2978 return types.isSameType(t, s) || 2979 !t.isPrimitive() && 2980 !s.isPrimitive() && 2981 types.isSubtype(t, s); 2982 } 2983 }, 2984 /** 2985 * Return r1 is more specific than r2 if r1 is return-type-substitutable for r2. 2986 */ 2987 RTS() { 2988 @Override 2989 public boolean test(Type mt1, Type mt2, Types types) { 2990 return types.returnTypeSubstitutable(mt1, mt2); 2991 } 2992 }; 2993 2994 public abstract boolean test(Type mt1, Type mt2, Types types); 2995 } 2996 2997 /** 2998 * Merge multiple abstract methods. The preferred method is a method that is a subsignature 2999 * of all the other signatures and whose return type is more specific {@see MostSpecificReturnCheck}. 3000 * The resulting preferred method has a thrown clause that is the intersection of the merged 3001 * methods' clauses. 3002 */ 3003 public Optional<Symbol> mergeAbstracts(List<Symbol> ambiguousInOrder, Type site, boolean sigCheck) { 3004 //first check for preconditions 3005 boolean shouldErase = false; 3006 List<Type> erasedParams = ambiguousInOrder.head.erasure(this).getParameterTypes(); 3007 for (Symbol s : ambiguousInOrder) { 3008 if ((s.flags() & ABSTRACT) == 0 || 3009 (sigCheck && !isSameTypes(erasedParams, s.erasure(this).getParameterTypes()))) { 3010 return Optional.empty(); 3011 } else if (s.type.hasTag(FORALL)) { 3012 shouldErase = true; 3013 } 3014 } 3015 //then merge abstracts 3016 for (MostSpecificReturnCheck mostSpecificReturnCheck : MostSpecificReturnCheck.values()) { 3017 outer: for (Symbol s : ambiguousInOrder) { 3018 Type mt = memberType(site, s); 3019 List<Type> allThrown = mt.getThrownTypes(); 3020 for (Symbol s2 : ambiguousInOrder) { 3021 if (s != s2) { 3022 Type mt2 = memberType(site, s2); 3023 if (!isSubSignature(mt, mt2) || 3024 !mostSpecificReturnCheck.test(mt, mt2, this)) { 3025 //ambiguity cannot be resolved 3026 continue outer; 3027 } else { 3028 List<Type> thrownTypes2 = mt2.getThrownTypes(); 3029 if (!mt.hasTag(FORALL) && shouldErase) { 3030 thrownTypes2 = erasure(thrownTypes2); 3031 } else if (mt.hasTag(FORALL)) { 3032 //subsignature implies that if most specific is generic, then all other 3033 //methods are too 3034 Assert.check(mt2.hasTag(FORALL)); 3035 // if both are generic methods, adjust thrown types ahead of intersection computation 3036 thrownTypes2 = subst(thrownTypes2, mt2.getTypeArguments(), mt.getTypeArguments()); 3037 } 3038 allThrown = chk.intersect(allThrown, thrownTypes2); 3039 } 3040 } 3041 } 3042 return (allThrown == mt.getThrownTypes()) ? 3043 Optional.of(s) : 3044 Optional.of(new MethodSymbol( 3045 s.flags(), 3046 s.name, 3047 createMethodTypeWithThrown(s.type, allThrown), 3048 s.owner) { 3049 @Override 3050 public Symbol baseSymbol() { 3051 return s; 3052 } 3053 }); 3054 } 3055 } 3056 return Optional.empty(); 3057 } 3058 3059 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site"> 3060 class ImplementationCache { 3061 3062 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map = new WeakHashMap<>(); 3063 3064 class Entry { 3065 final MethodSymbol cachedImpl; 3066 final Predicate<Symbol> implFilter; 3067 final boolean checkResult; 3068 final int prevMark; 3069 3070 public Entry(MethodSymbol cachedImpl, 3071 Predicate<Symbol> scopeFilter, 3072 boolean checkResult, 3073 int prevMark) { 3074 this.cachedImpl = cachedImpl; 3075 this.implFilter = scopeFilter; 3076 this.checkResult = checkResult; 3077 this.prevMark = prevMark; 3078 } 3079 3080 boolean matches(Predicate<Symbol> scopeFilter, boolean checkResult, int mark) { 3081 return this.implFilter == scopeFilter && 3082 this.checkResult == checkResult && 3083 this.prevMark == mark; 3084 } 3085 } 3086 3087 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) { 3088 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms); 3089 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null; 3090 if (cache == null) { 3091 cache = new HashMap<>(); 3092 _map.put(ms, new SoftReference<>(cache)); 3093 } 3094 Entry e = cache.get(origin); 3095 CompoundScope members = membersClosure(origin.type, true); 3096 if (e == null || 3097 !e.matches(implFilter, checkResult, members.getMark())) { 3098 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter); 3099 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark())); 3100 return impl; 3101 } 3102 else { 3103 return e.cachedImpl; 3104 } 3105 } 3106 3107 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) { 3108 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) { 3109 t = skipTypeVars(t, false); 3110 TypeSymbol c = t.tsym; 3111 Symbol bestSoFar = null; 3112 for (Symbol sym : c.members().getSymbolsByName(ms.name, implFilter)) { 3113 if (sym != null && sym.overrides(ms, origin, Types.this, checkResult)) { 3114 bestSoFar = sym; 3115 if ((sym.flags() & ABSTRACT) == 0) { 3116 //if concrete impl is found, exit immediately 3117 break; 3118 } 3119 } 3120 } 3121 if (bestSoFar != null) { 3122 //return either the (only) concrete implementation or the first abstract one 3123 return (MethodSymbol)bestSoFar; 3124 } 3125 } 3126 return null; 3127 } 3128 } 3129 3130 private ImplementationCache implCache = new ImplementationCache(); 3131 3132 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) { 3133 return implCache.get(ms, origin, checkResult, implFilter); 3134 } 3135 // </editor-fold> 3136 3137 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site"> 3138 class MembersClosureCache extends SimpleVisitor<Scope.CompoundScope, Void> { 3139 3140 private Map<TypeSymbol, CompoundScope> _map = new HashMap<>(); 3141 3142 Set<TypeSymbol> seenTypes = new HashSet<>(); 3143 3144 class MembersScope extends CompoundScope { 3145 3146 CompoundScope scope; 3147 3148 public MembersScope(CompoundScope scope) { 3149 super(scope.owner); 3150 this.scope = scope; 3151 } 3152 3153 Predicate<Symbol> combine(Predicate<Symbol> sf) { 3154 return s -> !s.owner.isInterface() && (sf == null || sf.test(s)); 3155 } 3156 3157 @Override 3158 public Iterable<Symbol> getSymbols(Predicate<Symbol> sf, LookupKind lookupKind) { 3159 return scope.getSymbols(combine(sf), lookupKind); 3160 } 3161 3162 @Override 3163 public Iterable<Symbol> getSymbolsByName(Name name, Predicate<Symbol> sf, LookupKind lookupKind) { 3164 return scope.getSymbolsByName(name, combine(sf), lookupKind); 3165 } 3166 3167 @Override 3168 public int getMark() { 3169 return scope.getMark(); 3170 } 3171 } 3172 3173 CompoundScope nilScope; 3174 3175 /** members closure visitor methods **/ 3176 3177 public CompoundScope visitType(Type t, Void _unused) { 3178 if (nilScope == null) { 3179 nilScope = new CompoundScope(syms.noSymbol); 3180 } 3181 return nilScope; 3182 } 3183 3184 @Override 3185 public CompoundScope visitClassType(ClassType t, Void _unused) { 3186 if (!seenTypes.add(t.tsym)) { 3187 //this is possible when an interface is implemented in multiple 3188 //superclasses, or when a class hierarchy is circular - in such 3189 //cases we don't need to recurse (empty scope is returned) 3190 return new CompoundScope(t.tsym); 3191 } 3192 try { 3193 seenTypes.add(t.tsym); 3194 ClassSymbol csym = (ClassSymbol)t.tsym; 3195 CompoundScope membersClosure = _map.get(csym); 3196 if (membersClosure == null) { 3197 membersClosure = new CompoundScope(csym); 3198 for (Type i : interfaces(t)) { 3199 membersClosure.prependSubScope(visit(i, null)); 3200 } 3201 membersClosure.prependSubScope(visit(supertype(t), null)); 3202 membersClosure.prependSubScope(csym.members()); 3203 _map.put(csym, membersClosure); 3204 } 3205 return membersClosure; 3206 } 3207 finally { 3208 seenTypes.remove(t.tsym); 3209 } 3210 } 3211 3212 @Override 3213 public CompoundScope visitTypeVar(TypeVar t, Void _unused) { 3214 return visit(t.getUpperBound(), null); 3215 } 3216 } 3217 3218 private MembersClosureCache membersCache = new MembersClosureCache(); 3219 3220 public CompoundScope membersClosure(Type site, boolean skipInterface) { 3221 CompoundScope cs = membersCache.visit(site, null); 3222 Assert.checkNonNull(cs, () -> "type " + site); 3223 return skipInterface ? membersCache.new MembersScope(cs) : cs; 3224 } 3225 // </editor-fold> 3226 3227 3228 /** Return first abstract member of class `sym'. 3229 */ 3230 public MethodSymbol firstUnimplementedAbstract(ClassSymbol sym) { 3231 try { 3232 return firstUnimplementedAbstractImpl(sym, sym); 3233 } catch (CompletionFailure ex) { 3234 chk.completionError(enter.getEnv(sym).tree.pos(), ex); 3235 return null; 3236 } 3237 } 3238 //where: 3239 private MethodSymbol firstUnimplementedAbstractImpl(ClassSymbol impl, ClassSymbol c) { 3240 MethodSymbol undef = null; 3241 // Do not bother to search in classes that are not abstract, 3242 // since they cannot have abstract members. 3243 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) { 3244 Scope s = c.members(); 3245 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) { 3246 if (sym.kind == MTH && 3247 (sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) { 3248 MethodSymbol absmeth = (MethodSymbol)sym; 3249 MethodSymbol implmeth = absmeth.implementation(impl, this, true); 3250 if (implmeth == null || implmeth == absmeth) { 3251 //look for default implementations 3252 MethodSymbol prov = interfaceCandidates(impl.type, absmeth).head; 3253 if (prov != null && prov.overrides(absmeth, impl, this, true)) { 3254 implmeth = prov; 3255 } 3256 } 3257 if (implmeth == null || implmeth == absmeth) { 3258 undef = absmeth; 3259 break; 3260 } 3261 } 3262 } 3263 if (undef == null) { 3264 Type st = supertype(c.type); 3265 if (st.hasTag(CLASS)) 3266 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)st.tsym); 3267 } 3268 for (List<Type> l = interfaces(c.type); 3269 undef == null && l.nonEmpty(); 3270 l = l.tail) { 3271 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)l.head.tsym); 3272 } 3273 } 3274 return undef; 3275 } 3276 3277 public class CandidatesCache { 3278 public Map<Entry, List<MethodSymbol>> cache = new WeakHashMap<>(); 3279 3280 class Entry { 3281 Type site; 3282 MethodSymbol msym; 3283 3284 Entry(Type site, MethodSymbol msym) { 3285 this.site = site; 3286 this.msym = msym; 3287 } 3288 3289 @Override 3290 public boolean equals(Object obj) { 3291 return (obj instanceof Entry entry) 3292 && entry.msym == msym 3293 && isSameType(site, entry.site); 3294 } 3295 3296 @Override 3297 public int hashCode() { 3298 return Types.this.hashCode(site) & ~msym.hashCode(); 3299 } 3300 } 3301 3302 public List<MethodSymbol> get(Entry e) { 3303 return cache.get(e); 3304 } 3305 3306 public void put(Entry e, List<MethodSymbol> msymbols) { 3307 cache.put(e, msymbols); 3308 } 3309 } 3310 3311 public CandidatesCache candidatesCache = new CandidatesCache(); 3312 3313 //where 3314 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) { 3315 CandidatesCache.Entry e = candidatesCache.new Entry(site, ms); 3316 List<MethodSymbol> candidates = candidatesCache.get(e); 3317 if (candidates == null) { 3318 Predicate<Symbol> filter = new MethodFilter(ms, site); 3319 List<MethodSymbol> candidates2 = List.nil(); 3320 for (Symbol s : membersClosure(site, false).getSymbols(filter)) { 3321 if (!site.tsym.isInterface() && !s.owner.isInterface()) { 3322 return List.of((MethodSymbol)s); 3323 } else if (!candidates2.contains(s)) { 3324 candidates2 = candidates2.prepend((MethodSymbol)s); 3325 } 3326 } 3327 candidates = prune(candidates2); 3328 candidatesCache.put(e, candidates); 3329 } 3330 return candidates; 3331 } 3332 3333 public List<MethodSymbol> prune(List<MethodSymbol> methods) { 3334 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>(); 3335 for (MethodSymbol m1 : methods) { 3336 boolean isMin_m1 = true; 3337 for (MethodSymbol m2 : methods) { 3338 if (m1 == m2) continue; 3339 if (m2.owner != m1.owner && 3340 asSuper(m2.owner.type, m1.owner) != null) { 3341 isMin_m1 = false; 3342 break; 3343 } 3344 } 3345 if (isMin_m1) 3346 methodsMin.append(m1); 3347 } 3348 return methodsMin.toList(); 3349 } 3350 // where 3351 private class MethodFilter implements Predicate<Symbol> { 3352 3353 Symbol msym; 3354 Type site; 3355 3356 MethodFilter(Symbol msym, Type site) { 3357 this.msym = msym; 3358 this.site = site; 3359 } 3360 3361 @Override 3362 public boolean test(Symbol s) { 3363 return s.kind == MTH && 3364 s.name == msym.name && 3365 (s.flags() & SYNTHETIC) == 0 && 3366 s.isInheritedIn(site.tsym, Types.this) && 3367 overrideEquivalent(memberType(site, s), memberType(site, msym)); 3368 } 3369 } 3370 // </editor-fold> 3371 3372 /** 3373 * Does t have the same arguments as s? It is assumed that both 3374 * types are (possibly polymorphic) method types. Monomorphic 3375 * method types "have the same arguments", if their argument lists 3376 * are equal. Polymorphic method types "have the same arguments", 3377 * if they have the same arguments after renaming all type 3378 * variables of one to corresponding type variables in the other, 3379 * where correspondence is by position in the type parameter list. 3380 */ 3381 public boolean hasSameArgs(Type t, Type s) { 3382 return hasSameArgs(t, s, true); 3383 } 3384 3385 public boolean hasSameArgs(Type t, Type s, boolean strict) { 3386 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict); 3387 } 3388 3389 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) { 3390 return hasSameArgs.visit(t, s); 3391 } 3392 // where 3393 private class HasSameArgs extends TypeRelation { 3394 3395 boolean strict; 3396 3397 public HasSameArgs(boolean strict) { 3398 this.strict = strict; 3399 } 3400 3401 public Boolean visitType(Type t, Type s) { 3402 throw new AssertionError(); 3403 } 3404 3405 @Override 3406 public Boolean visitMethodType(MethodType t, Type s) { 3407 return s.hasTag(METHOD) 3408 && containsTypeEquivalent(t.argtypes, s.getParameterTypes()); 3409 } 3410 3411 @Override 3412 public Boolean visitForAll(ForAll t, Type s) { 3413 if (!s.hasTag(FORALL)) 3414 return strict ? false : visitMethodType(t.asMethodType(), s); 3415 3416 ForAll forAll = (ForAll)s; 3417 return hasSameBounds(t, forAll) 3418 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); 3419 } 3420 3421 @Override 3422 public Boolean visitErrorType(ErrorType t, Type s) { 3423 return false; 3424 } 3425 } 3426 3427 TypeRelation hasSameArgs_strict = new HasSameArgs(true); 3428 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false); 3429 3430 // </editor-fold> 3431 3432 // <editor-fold defaultstate="collapsed" desc="subst"> 3433 public List<Type> subst(List<Type> ts, 3434 List<Type> from, 3435 List<Type> to) { 3436 return ts.map(new Subst(from, to)); 3437 } 3438 3439 /** 3440 * Substitute all occurrences of a type in `from' with the 3441 * corresponding type in `to' in 't'. Match lists `from' and `to' 3442 * from the right: If lists have different length, discard leading 3443 * elements of the longer list. 3444 */ 3445 public Type subst(Type t, List<Type> from, List<Type> to) { 3446 return t.map(new Subst(from, to)); 3447 } 3448 3449 private class Subst extends StructuralTypeMapping<Void> { 3450 List<Type> from; 3451 List<Type> to; 3452 3453 public Subst(List<Type> from, List<Type> to) { 3454 int fromLength = from.length(); 3455 int toLength = to.length(); 3456 while (fromLength > toLength) { 3457 fromLength--; 3458 from = from.tail; 3459 } 3460 while (fromLength < toLength) { 3461 toLength--; 3462 to = to.tail; 3463 } 3464 this.from = from; 3465 this.to = to; 3466 } 3467 3468 @Override 3469 public Type visitTypeVar(TypeVar t, Void ignored) { 3470 for (List<Type> from = this.from, to = this.to; 3471 from.nonEmpty(); 3472 from = from.tail, to = to.tail) { 3473 if (t.equalsIgnoreMetadata(from.head)) { 3474 return to.head.withTypeVar(t); 3475 } 3476 } 3477 return t; 3478 } 3479 3480 @Override 3481 public Type visitClassType(ClassType t, Void ignored) { 3482 if (!t.isCompound()) { 3483 return super.visitClassType(t, ignored); 3484 } else { 3485 Type st = visit(supertype(t)); 3486 List<Type> is = visit(interfaces(t), ignored); 3487 if (st == supertype(t) && is == interfaces(t)) 3488 return t; 3489 else 3490 return makeIntersectionType(is.prepend(st)); 3491 } 3492 } 3493 3494 @Override 3495 public Type visitWildcardType(WildcardType t, Void ignored) { 3496 WildcardType t2 = (WildcardType)super.visitWildcardType(t, ignored); 3497 if (t2 != t && t.isExtendsBound() && t2.type.isExtendsBound()) { 3498 t2.type = wildUpperBound(t2.type); 3499 } 3500 return t2; 3501 } 3502 3503 @Override 3504 public Type visitForAll(ForAll t, Void ignored) { 3505 if (Type.containsAny(to, t.tvars)) { 3506 //perform alpha-renaming of free-variables in 't' 3507 //if 'to' types contain variables that are free in 't' 3508 List<Type> freevars = newInstances(t.tvars); 3509 t = new ForAll(freevars, 3510 Types.this.subst(t.qtype, t.tvars, freevars)); 3511 } 3512 List<Type> tvars1 = substBounds(t.tvars, from, to); 3513 Type qtype1 = visit(t.qtype); 3514 if (tvars1 == t.tvars && qtype1 == t.qtype) { 3515 return t; 3516 } else if (tvars1 == t.tvars) { 3517 return new ForAll(tvars1, qtype1) { 3518 @Override 3519 public boolean needsStripping() { 3520 return true; 3521 } 3522 }; 3523 } else { 3524 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1)) { 3525 @Override 3526 public boolean needsStripping() { 3527 return true; 3528 } 3529 }; 3530 } 3531 } 3532 } 3533 3534 public List<Type> substBounds(List<Type> tvars, 3535 List<Type> from, 3536 List<Type> to) { 3537 if (tvars.isEmpty()) 3538 return tvars; 3539 ListBuffer<Type> newBoundsBuf = new ListBuffer<>(); 3540 boolean changed = false; 3541 // calculate new bounds 3542 for (Type t : tvars) { 3543 TypeVar tv = (TypeVar) t; 3544 Type bound = subst(tv.getUpperBound(), from, to); 3545 if (bound != tv.getUpperBound()) 3546 changed = true; 3547 newBoundsBuf.append(bound); 3548 } 3549 if (!changed) 3550 return tvars; 3551 ListBuffer<Type> newTvars = new ListBuffer<>(); 3552 // create new type variables without bounds 3553 for (Type t : tvars) { 3554 newTvars.append(new TypeVar(t.tsym, null, syms.botType, 3555 t.getMetadata())); 3556 } 3557 // the new bounds should use the new type variables in place 3558 // of the old 3559 List<Type> newBounds = newBoundsBuf.toList(); 3560 from = tvars; 3561 to = newTvars.toList(); 3562 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) { 3563 newBounds.head = subst(newBounds.head, from, to); 3564 } 3565 newBounds = newBoundsBuf.toList(); 3566 // set the bounds of new type variables to the new bounds 3567 for (Type t : newTvars.toList()) { 3568 TypeVar tv = (TypeVar) t; 3569 tv.setUpperBound( newBounds.head ); 3570 newBounds = newBounds.tail; 3571 } 3572 return newTvars.toList(); 3573 } 3574 3575 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) { 3576 Type bound1 = subst(t.getUpperBound(), from, to); 3577 if (bound1 == t.getUpperBound()) 3578 return t; 3579 else { 3580 // create new type variable without bounds 3581 TypeVar tv = new TypeVar(t.tsym, null, syms.botType, 3582 t.getMetadata()); 3583 // the new bound should use the new type variable in place 3584 // of the old 3585 tv.setUpperBound( subst(bound1, List.of(t), List.of(tv)) ); 3586 return tv; 3587 } 3588 } 3589 // </editor-fold> 3590 3591 // <editor-fold defaultstate="collapsed" desc="hasSameBounds"> 3592 /** 3593 * Does t have the same bounds for quantified variables as s? 3594 */ 3595 public boolean hasSameBounds(ForAll t, ForAll s) { 3596 List<Type> l1 = t.tvars; 3597 List<Type> l2 = s.tvars; 3598 while (l1.nonEmpty() && l2.nonEmpty() && 3599 isSameType(l1.head.getUpperBound(), 3600 subst(l2.head.getUpperBound(), 3601 s.tvars, 3602 t.tvars))) { 3603 l1 = l1.tail; 3604 l2 = l2.tail; 3605 } 3606 return l1.isEmpty() && l2.isEmpty(); 3607 } 3608 // </editor-fold> 3609 3610 // <editor-fold defaultstate="collapsed" desc="newInstances"> 3611 /** Create new vector of type variables from list of variables 3612 * changing all recursive bounds from old to new list. 3613 */ 3614 public List<Type> newInstances(List<Type> tvars) { 3615 List<Type> tvars1 = tvars.map(newInstanceFun); 3616 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) { 3617 TypeVar tv = (TypeVar) l.head; 3618 tv.setUpperBound( subst(tv.getUpperBound(), tvars, tvars1) ); 3619 } 3620 return tvars1; 3621 } 3622 private static final TypeMapping<Void> newInstanceFun = new TypeMapping<Void>() { 3623 @Override 3624 public TypeVar visitTypeVar(TypeVar t, Void _unused) { 3625 return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound(), t.getMetadata()); 3626 } 3627 }; 3628 // </editor-fold> 3629 3630 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) { 3631 return original.accept(methodWithParameters, newParams); 3632 } 3633 // where 3634 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() { 3635 public Type visitType(Type t, List<Type> newParams) { 3636 throw new IllegalArgumentException("Not a method type: " + t); 3637 } 3638 public Type visitMethodType(MethodType t, List<Type> newParams) { 3639 return new MethodType(newParams, t.restype, t.thrown, t.tsym); 3640 } 3641 public Type visitForAll(ForAll t, List<Type> newParams) { 3642 return new ForAll(t.tvars, t.qtype.accept(this, newParams)); 3643 } 3644 }; 3645 3646 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) { 3647 return original.accept(methodWithThrown, newThrown); 3648 } 3649 // where 3650 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() { 3651 public Type visitType(Type t, List<Type> newThrown) { 3652 throw new IllegalArgumentException("Not a method type: " + t); 3653 } 3654 public Type visitMethodType(MethodType t, List<Type> newThrown) { 3655 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym); 3656 } 3657 public Type visitForAll(ForAll t, List<Type> newThrown) { 3658 return new ForAll(t.tvars, t.qtype.accept(this, newThrown)); 3659 } 3660 }; 3661 3662 public Type createMethodTypeWithReturn(Type original, Type newReturn) { 3663 return original.accept(methodWithReturn, newReturn); 3664 } 3665 // where 3666 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() { 3667 public Type visitType(Type t, Type newReturn) { 3668 throw new IllegalArgumentException("Not a method type: " + t); 3669 } 3670 public Type visitMethodType(MethodType t, Type newReturn) { 3671 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym) { 3672 @Override 3673 public Type baseType() { 3674 return t; 3675 } 3676 }; 3677 } 3678 public Type visitForAll(ForAll t, Type newReturn) { 3679 return new ForAll(t.tvars, t.qtype.accept(this, newReturn)) { 3680 @Override 3681 public Type baseType() { 3682 return t; 3683 } 3684 }; 3685 } 3686 }; 3687 3688 // <editor-fold defaultstate="collapsed" desc="createErrorType"> 3689 public Type createErrorType(Type originalType) { 3690 return new ErrorType(originalType, syms.errSymbol); 3691 } 3692 3693 public Type createErrorType(ClassSymbol c, Type originalType) { 3694 return new ErrorType(c, originalType); 3695 } 3696 3697 public Type createErrorType(Name name, TypeSymbol container, Type originalType) { 3698 return new ErrorType(name, container, originalType); 3699 } 3700 // </editor-fold> 3701 3702 // <editor-fold defaultstate="collapsed" desc="rank"> 3703 /** 3704 * The rank of a class is the length of the longest path between 3705 * the class and java.lang.Object in the class inheritance 3706 * graph. Undefined for all but reference types. 3707 */ 3708 public int rank(Type t) { 3709 switch(t.getTag()) { 3710 case CLASS: { 3711 ClassType cls = (ClassType)t; 3712 if (cls.rank_field < 0) { 3713 Name fullname = cls.tsym.getQualifiedName(); 3714 if (fullname == names.java_lang_Object) 3715 cls.rank_field = 0; 3716 else { 3717 int r = rank(supertype(cls)); 3718 for (List<Type> l = interfaces(cls); 3719 l.nonEmpty(); 3720 l = l.tail) { 3721 if (rank(l.head) > r) 3722 r = rank(l.head); 3723 } 3724 cls.rank_field = r + 1; 3725 } 3726 } 3727 return cls.rank_field; 3728 } 3729 case TYPEVAR: { 3730 TypeVar tvar = (TypeVar)t; 3731 if (tvar.rank_field < 0) { 3732 int r = rank(supertype(tvar)); 3733 for (List<Type> l = interfaces(tvar); 3734 l.nonEmpty(); 3735 l = l.tail) { 3736 if (rank(l.head) > r) r = rank(l.head); 3737 } 3738 tvar.rank_field = r + 1; 3739 } 3740 return tvar.rank_field; 3741 } 3742 case ERROR: 3743 case NONE: 3744 return 0; 3745 default: 3746 throw new AssertionError(); 3747 } 3748 } 3749 // </editor-fold> 3750 3751 /** Cache the symbol to reflect the qualifying type. 3752 * key: corresponding type 3753 * value: qualified symbol 3754 */ 3755 private Map<Type, Symbol> qualifiedSymbolCache; 3756 3757 public void clearQualifiedSymbolCache() { 3758 qualifiedSymbolCache.clear(); 3759 } 3760 3761 /** Construct a symbol to reflect the qualifying type that should 3762 * appear in the byte code as per JLS 13.1. 3763 * 3764 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except 3765 * for those cases where we need to work around VM bugs). 3766 * 3767 * For {@literal target <= 1.1}: If qualified variable or method is defined in a 3768 * non-accessible class, clone it with the qualifier class as owner. 3769 * 3770 * @param sym The accessed symbol 3771 * @param site The qualifier's type. 3772 */ 3773 public Symbol binaryQualifier(Symbol sym, Type site) { 3774 3775 if (site.hasTag(ARRAY)) { 3776 if (sym == syms.lengthVar || 3777 sym.owner != syms.arrayClass) 3778 return sym; 3779 // array clone can be qualified by the array type in later targets 3780 Symbol qualifier; 3781 if ((qualifier = qualifiedSymbolCache.get(site)) == null) { 3782 qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, site, syms.noSymbol); 3783 qualifiedSymbolCache.put(site, qualifier); 3784 } 3785 return sym.clone(qualifier); 3786 } 3787 3788 if (sym.owner == site.tsym || 3789 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) { 3790 return sym; 3791 } 3792 3793 // leave alone methods inherited from Object 3794 // JLS 13.1. 3795 if (sym.owner == syms.objectType.tsym) 3796 return sym; 3797 3798 return sym.clone(site.tsym); 3799 } 3800 3801 /** 3802 * Helper method for generating a string representation of a given type 3803 * accordingly to a given locale 3804 */ 3805 public String toString(Type t, Locale locale) { 3806 return Printer.createStandardPrinter(messages).visit(t, locale); 3807 } 3808 3809 /** 3810 * Helper method for generating a string representation of a given type 3811 * accordingly to a given locale 3812 */ 3813 public String toString(Symbol t, Locale locale) { 3814 return Printer.createStandardPrinter(messages).visit(t, locale); 3815 } 3816 3817 // <editor-fold defaultstate="collapsed" desc="toString"> 3818 /** 3819 * This toString is slightly more descriptive than the one on Type. 3820 * 3821 * @deprecated Types.toString(Type t, Locale l) provides better support 3822 * for localization 3823 */ 3824 @Deprecated 3825 public String toString(Type t) { 3826 if (t.hasTag(FORALL)) { 3827 ForAll forAll = (ForAll)t; 3828 return typaramsString(forAll.tvars) + forAll.qtype; 3829 } 3830 return "" + t; 3831 } 3832 // where 3833 private String typaramsString(List<Type> tvars) { 3834 StringBuilder s = new StringBuilder(); 3835 s.append('<'); 3836 boolean first = true; 3837 for (Type t : tvars) { 3838 if (!first) s.append(", "); 3839 first = false; 3840 appendTyparamString(((TypeVar)t), s); 3841 } 3842 s.append('>'); 3843 return s.toString(); 3844 } 3845 private void appendTyparamString(TypeVar t, StringBuilder buf) { 3846 buf.append(t); 3847 if (t.getUpperBound() == null || 3848 t.getUpperBound().tsym.getQualifiedName() == names.java_lang_Object) 3849 return; 3850 buf.append(" extends "); // Java syntax; no need for i18n 3851 Type bound = t.getUpperBound(); 3852 if (!bound.isCompound()) { 3853 buf.append(bound); 3854 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) { 3855 buf.append(supertype(t)); 3856 for (Type intf : interfaces(t)) { 3857 buf.append('&'); 3858 buf.append(intf); 3859 } 3860 } else { 3861 // No superclass was given in bounds. 3862 // In this case, supertype is Object, erasure is first interface. 3863 boolean first = true; 3864 for (Type intf : interfaces(t)) { 3865 if (!first) buf.append('&'); 3866 first = false; 3867 buf.append(intf); 3868 } 3869 } 3870 } 3871 // </editor-fold> 3872 3873 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types"> 3874 /** 3875 * A cache for closures. 3876 * 3877 * <p>A closure is a list of all the supertypes and interfaces of 3878 * a class or interface type, ordered by ClassSymbol.precedes 3879 * (that is, subclasses come first, arbitrary but fixed 3880 * otherwise). 3881 */ 3882 private Map<Type,List<Type>> closureCache = new HashMap<>(); 3883 3884 /** 3885 * Returns the closure of a class or interface type. 3886 */ 3887 public List<Type> closure(Type t) { 3888 List<Type> cl = closureCache.get(t); 3889 if (cl == null) { 3890 Type st = supertype(t); 3891 if (!t.isCompound()) { 3892 if (st.hasTag(CLASS)) { 3893 cl = insert(closure(st), t); 3894 } else if (st.hasTag(TYPEVAR)) { 3895 cl = closure(st).prepend(t); 3896 } else { 3897 cl = List.of(t); 3898 } 3899 } else { 3900 cl = closure(supertype(t)); 3901 } 3902 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) 3903 cl = union(cl, closure(l.head)); 3904 closureCache.put(t, cl); 3905 } 3906 return cl; 3907 } 3908 3909 /** 3910 * Collect types into a new closure (using a @code{ClosureHolder}) 3911 */ 3912 public Collector<Type, ClosureHolder, List<Type>> closureCollector(boolean minClosure, BiPredicate<Type, Type> shouldSkip) { 3913 return Collector.of(() -> new ClosureHolder(minClosure, shouldSkip), 3914 ClosureHolder::add, 3915 ClosureHolder::merge, 3916 ClosureHolder::closure); 3917 } 3918 //where 3919 class ClosureHolder { 3920 List<Type> closure; 3921 final boolean minClosure; 3922 final BiPredicate<Type, Type> shouldSkip; 3923 3924 ClosureHolder(boolean minClosure, BiPredicate<Type, Type> shouldSkip) { 3925 this.closure = List.nil(); 3926 this.minClosure = minClosure; 3927 this.shouldSkip = shouldSkip; 3928 } 3929 3930 void add(Type type) { 3931 closure = insert(closure, type, shouldSkip); 3932 } 3933 3934 ClosureHolder merge(ClosureHolder other) { 3935 closure = union(closure, other.closure, shouldSkip); 3936 return this; 3937 } 3938 3939 List<Type> closure() { 3940 return minClosure ? closureMin(closure) : closure; 3941 } 3942 } 3943 3944 BiPredicate<Type, Type> basicClosureSkip = (t1, t2) -> t1.tsym == t2.tsym; 3945 3946 /** 3947 * Insert a type in a closure 3948 */ 3949 public List<Type> insert(List<Type> cl, Type t, BiPredicate<Type, Type> shouldSkip) { 3950 if (cl.isEmpty()) { 3951 return cl.prepend(t); 3952 } else if (shouldSkip.test(t, cl.head)) { 3953 return cl; 3954 } else if (t.tsym.precedes(cl.head.tsym, this)) { 3955 return cl.prepend(t); 3956 } else { 3957 // t comes after head, or the two are unrelated 3958 return insert(cl.tail, t, shouldSkip).prepend(cl.head); 3959 } 3960 } 3961 3962 public List<Type> insert(List<Type> cl, Type t) { 3963 return insert(cl, t, basicClosureSkip); 3964 } 3965 3966 /** 3967 * Form the union of two closures 3968 */ 3969 public List<Type> union(List<Type> cl1, List<Type> cl2, BiPredicate<Type, Type> shouldSkip) { 3970 if (cl1.isEmpty()) { 3971 return cl2; 3972 } else if (cl2.isEmpty()) { 3973 return cl1; 3974 } else if (shouldSkip.test(cl1.head, cl2.head)) { 3975 return union(cl1.tail, cl2.tail, shouldSkip).prepend(cl1.head); 3976 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) { 3977 return union(cl1, cl2.tail, shouldSkip).prepend(cl2.head); 3978 } else { 3979 return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head); 3980 } 3981 } 3982 3983 public List<Type> union(List<Type> cl1, List<Type> cl2) { 3984 return union(cl1, cl2, basicClosureSkip); 3985 } 3986 3987 /** 3988 * Intersect two closures 3989 */ 3990 public List<Type> intersect(List<Type> cl1, List<Type> cl2) { 3991 if (cl1 == cl2) 3992 return cl1; 3993 if (cl1.isEmpty() || cl2.isEmpty()) 3994 return List.nil(); 3995 if (cl1.head.tsym.precedes(cl2.head.tsym, this)) 3996 return intersect(cl1.tail, cl2); 3997 if (cl2.head.tsym.precedes(cl1.head.tsym, this)) 3998 return intersect(cl1, cl2.tail); 3999 if (isSameType(cl1.head, cl2.head)) 4000 return intersect(cl1.tail, cl2.tail).prepend(cl1.head); 4001 if (cl1.head.tsym == cl2.head.tsym && 4002 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) { 4003 if (cl1.head.isParameterized() && cl2.head.isParameterized()) { 4004 Type merge = merge(cl1.head,cl2.head); 4005 return intersect(cl1.tail, cl2.tail).prepend(merge); 4006 } 4007 if (cl1.head.isRaw() || cl2.head.isRaw()) 4008 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head)); 4009 } 4010 return intersect(cl1.tail, cl2.tail); 4011 } 4012 // where 4013 class TypePair { 4014 final Type t1; 4015 final Type t2;; 4016 4017 TypePair(Type t1, Type t2) { 4018 this.t1 = t1; 4019 this.t2 = t2; 4020 } 4021 @Override 4022 public int hashCode() { 4023 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2); 4024 } 4025 @Override 4026 public boolean equals(Object obj) { 4027 return (obj instanceof TypePair typePair) 4028 && isSameType(t1, typePair.t1) 4029 && isSameType(t2, typePair.t2); 4030 } 4031 } 4032 Set<TypePair> mergeCache = new HashSet<>(); 4033 private Type merge(Type c1, Type c2) { 4034 ClassType class1 = (ClassType) c1; 4035 List<Type> act1 = class1.getTypeArguments(); 4036 ClassType class2 = (ClassType) c2; 4037 List<Type> act2 = class2.getTypeArguments(); 4038 ListBuffer<Type> merged = new ListBuffer<>(); 4039 List<Type> typarams = class1.tsym.type.getTypeArguments(); 4040 4041 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) { 4042 if (containsType(act1.head, act2.head)) { 4043 merged.append(act1.head); 4044 } else if (containsType(act2.head, act1.head)) { 4045 merged.append(act2.head); 4046 } else { 4047 TypePair pair = new TypePair(c1, c2); 4048 Type m; 4049 if (mergeCache.add(pair)) { 4050 m = new WildcardType(lub(wildUpperBound(act1.head), 4051 wildUpperBound(act2.head)), 4052 BoundKind.EXTENDS, 4053 syms.boundClass); 4054 mergeCache.remove(pair); 4055 } else { 4056 m = new WildcardType(syms.objectType, 4057 BoundKind.UNBOUND, 4058 syms.boundClass); 4059 } 4060 merged.append(m.withTypeVar(typarams.head)); 4061 } 4062 act1 = act1.tail; 4063 act2 = act2.tail; 4064 typarams = typarams.tail; 4065 } 4066 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty()); 4067 // There is no spec detailing how type annotations are to 4068 // be inherited. So set it to noAnnotations for now 4069 return new ClassType(class1.getEnclosingType(), merged.toList(), 4070 class1.tsym, TypeMetadata.EMPTY, class1.getFlavor()); 4071 } 4072 4073 /** 4074 * Return the minimum type of a closure, a compound type if no 4075 * unique minimum exists. 4076 */ 4077 private Type compoundMin(List<Type> cl) { 4078 if (cl.isEmpty()) return syms.objectType; 4079 List<Type> compound = closureMin(cl); 4080 if (compound.isEmpty()) 4081 return null; 4082 else if (compound.tail.isEmpty()) 4083 return compound.head; 4084 else 4085 return makeIntersectionType(compound); 4086 } 4087 4088 /** 4089 * Return the minimum types of a closure, suitable for computing 4090 * compoundMin or glb. 4091 */ 4092 private List<Type> closureMin(List<Type> cl) { 4093 ListBuffer<Type> classes = new ListBuffer<>(); 4094 ListBuffer<Type> interfaces = new ListBuffer<>(); 4095 Set<Type> toSkip = new HashSet<>(); 4096 while (!cl.isEmpty()) { 4097 Type current = cl.head; 4098 boolean keep = !toSkip.contains(current); 4099 if (keep && current.hasTag(TYPEVAR)) { 4100 // skip lower-bounded variables with a subtype in cl.tail 4101 for (Type t : cl.tail) { 4102 if (isSubtypeNoCapture(t, current)) { 4103 keep = false; 4104 break; 4105 } 4106 } 4107 } 4108 if (keep) { 4109 if (current.isInterface()) 4110 interfaces.append(current); 4111 else 4112 classes.append(current); 4113 for (Type t : cl.tail) { 4114 // skip supertypes of 'current' in cl.tail 4115 if (isSubtypeNoCapture(current, t)) 4116 toSkip.add(t); 4117 } 4118 } 4119 cl = cl.tail; 4120 } 4121 return classes.appendList(interfaces).toList(); 4122 } 4123 4124 /** 4125 * Return the least upper bound of list of types. if the lub does 4126 * not exist return null. 4127 */ 4128 public Type lub(List<Type> ts) { 4129 return lub(ts.toArray(new Type[ts.length()])); 4130 } 4131 4132 /** 4133 * Return the least upper bound (lub) of set of types. If the lub 4134 * does not exist return the type of null (bottom). 4135 */ 4136 public Type lub(Type... ts) { 4137 final int UNKNOWN_BOUND = 0; 4138 final int ARRAY_BOUND = 1; 4139 final int CLASS_BOUND = 2; 4140 4141 int[] kinds = new int[ts.length]; 4142 4143 int boundkind = UNKNOWN_BOUND; 4144 for (int i = 0 ; i < ts.length ; i++) { 4145 Type t = ts[i]; 4146 switch (t.getTag()) { 4147 case CLASS: 4148 boundkind |= kinds[i] = CLASS_BOUND; 4149 break; 4150 case ARRAY: 4151 boundkind |= kinds[i] = ARRAY_BOUND; 4152 break; 4153 case TYPEVAR: 4154 do { 4155 t = t.getUpperBound(); 4156 } while (t.hasTag(TYPEVAR)); 4157 if (t.hasTag(ARRAY)) { 4158 boundkind |= kinds[i] = ARRAY_BOUND; 4159 } else { 4160 boundkind |= kinds[i] = CLASS_BOUND; 4161 } 4162 break; 4163 default: 4164 kinds[i] = UNKNOWN_BOUND; 4165 if (t.isPrimitive()) 4166 return syms.errType; 4167 } 4168 } 4169 switch (boundkind) { 4170 case 0: 4171 return syms.botType; 4172 4173 case ARRAY_BOUND: 4174 // calculate lub(A[], B[]) 4175 Type[] elements = new Type[ts.length]; 4176 for (int i = 0 ; i < ts.length ; i++) { 4177 Type elem = elements[i] = elemTypeFun.apply(ts[i]); 4178 if (elem.isPrimitive()) { 4179 // if a primitive type is found, then return 4180 // arraySuperType unless all the types are the 4181 // same 4182 Type first = ts[0]; 4183 for (int j = 1 ; j < ts.length ; j++) { 4184 if (!isSameType(first, ts[j])) { 4185 // lub(int[], B[]) is Cloneable & Serializable 4186 return arraySuperType(); 4187 } 4188 } 4189 // all the array types are the same, return one 4190 // lub(int[], int[]) is int[] 4191 return first; 4192 } 4193 } 4194 // lub(A[], B[]) is lub(A, B)[] 4195 return new ArrayType(lub(elements), syms.arrayClass); 4196 4197 case CLASS_BOUND: 4198 // calculate lub(A, B) 4199 int startIdx = 0; 4200 for (int i = 0; i < ts.length ; i++) { 4201 Type t = ts[i]; 4202 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) { 4203 break; 4204 } else { 4205 startIdx++; 4206 } 4207 } 4208 Assert.check(startIdx < ts.length); 4209 //step 1 - compute erased candidate set (EC) 4210 List<Type> cl = erasedSupertypes(ts[startIdx]); 4211 for (int i = startIdx + 1 ; i < ts.length ; i++) { 4212 Type t = ts[i]; 4213 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) 4214 cl = intersect(cl, erasedSupertypes(t)); 4215 } 4216 //step 2 - compute minimal erased candidate set (MEC) 4217 List<Type> mec = closureMin(cl); 4218 //step 3 - for each element G in MEC, compute lci(Inv(G)) 4219 List<Type> candidates = List.nil(); 4220 for (Type erasedSupertype : mec) { 4221 List<Type> lci = List.of(asSuper(ts[startIdx], erasedSupertype.tsym)); 4222 for (int i = startIdx + 1 ; i < ts.length ; i++) { 4223 Type superType = asSuper(ts[i], erasedSupertype.tsym); 4224 lci = intersect(lci, superType != null ? List.of(superType) : List.nil()); 4225 } 4226 candidates = candidates.appendList(lci); 4227 } 4228 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that 4229 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn)) 4230 return compoundMin(candidates); 4231 4232 default: 4233 // calculate lub(A, B[]) 4234 List<Type> classes = List.of(arraySuperType()); 4235 for (int i = 0 ; i < ts.length ; i++) { 4236 if (kinds[i] != ARRAY_BOUND) // Filter out any arrays 4237 classes = classes.prepend(ts[i]); 4238 } 4239 // lub(A, B[]) is lub(A, arraySuperType) 4240 return lub(classes); 4241 } 4242 } 4243 // where 4244 List<Type> erasedSupertypes(Type t) { 4245 ListBuffer<Type> buf = new ListBuffer<>(); 4246 for (Type sup : closure(t)) { 4247 if (sup.hasTag(TYPEVAR)) { 4248 buf.append(sup); 4249 } else { 4250 buf.append(erasure(sup)); 4251 } 4252 } 4253 return buf.toList(); 4254 } 4255 4256 private Type arraySuperType; 4257 private Type arraySuperType() { 4258 // initialized lazily to avoid problems during compiler startup 4259 if (arraySuperType == null) { 4260 // JLS 10.8: all arrays implement Cloneable and Serializable. 4261 arraySuperType = makeIntersectionType(List.of(syms.serializableType, 4262 syms.cloneableType), true); 4263 } 4264 return arraySuperType; 4265 } 4266 // </editor-fold> 4267 4268 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound"> 4269 public Type glb(List<Type> ts) { 4270 Type t1 = ts.head; 4271 for (Type t2 : ts.tail) { 4272 if (t1.isErroneous()) 4273 return t1; 4274 t1 = glb(t1, t2); 4275 } 4276 return t1; 4277 } 4278 //where 4279 public Type glb(Type t, Type s) { 4280 if (s == null) 4281 return t; 4282 else if (t.isPrimitive() || s.isPrimitive()) 4283 return syms.errType; 4284 else if (isSubtypeNoCapture(t, s)) 4285 return t; 4286 else if (isSubtypeNoCapture(s, t)) 4287 return s; 4288 4289 List<Type> closure = union(closure(t), closure(s)); 4290 return glbFlattened(closure, t); 4291 } 4292 //where 4293 /** 4294 * Perform glb for a list of non-primitive, non-error, non-compound types; 4295 * redundant elements are removed. Bounds should be ordered according to 4296 * {@link Symbol#precedes(TypeSymbol,Types)}. 4297 * 4298 * @param flatBounds List of type to glb 4299 * @param errT Original type to use if the result is an error type 4300 */ 4301 private Type glbFlattened(List<Type> flatBounds, Type errT) { 4302 List<Type> bounds = closureMin(flatBounds); 4303 4304 if (bounds.isEmpty()) { // length == 0 4305 return syms.objectType; 4306 } else if (bounds.tail.isEmpty()) { // length == 1 4307 return bounds.head; 4308 } else { // length > 1 4309 int classCount = 0; 4310 List<Type> cvars = List.nil(); 4311 List<Type> lowers = List.nil(); 4312 for (Type bound : bounds) { 4313 if (!bound.isInterface()) { 4314 classCount++; 4315 Type lower = cvarLowerBound(bound); 4316 if (bound != lower && !lower.hasTag(BOT)) { 4317 cvars = cvars.append(bound); 4318 lowers = lowers.append(lower); 4319 } 4320 } 4321 } 4322 if (classCount > 1) { 4323 if (lowers.isEmpty()) { 4324 return createErrorType(errT); 4325 } else { 4326 // try again with lower bounds included instead of capture variables 4327 List<Type> newBounds = bounds.diff(cvars).appendList(lowers); 4328 return glb(newBounds); 4329 } 4330 } 4331 } 4332 return makeIntersectionType(bounds); 4333 } 4334 // </editor-fold> 4335 4336 // <editor-fold defaultstate="collapsed" desc="hashCode"> 4337 /** 4338 * Compute a hash code on a type. 4339 */ 4340 public int hashCode(Type t) { 4341 return hashCode(t, false); 4342 } 4343 4344 public int hashCode(Type t, boolean strict) { 4345 return strict ? 4346 hashCodeStrictVisitor.visit(t) : 4347 hashCodeVisitor.visit(t); 4348 } 4349 // where 4350 private static final HashCodeVisitor hashCodeVisitor = new HashCodeVisitor(); 4351 private static final HashCodeVisitor hashCodeStrictVisitor = new HashCodeVisitor() { 4352 @Override 4353 public Integer visitTypeVar(TypeVar t, Void ignored) { 4354 return System.identityHashCode(t); 4355 } 4356 }; 4357 4358 private static class HashCodeVisitor extends UnaryVisitor<Integer> { 4359 public Integer visitType(Type t, Void ignored) { 4360 return t.getTag().ordinal(); 4361 } 4362 4363 @Override 4364 public Integer visitClassType(ClassType t, Void ignored) { 4365 int result = visit(t.getEnclosingType()); 4366 result *= 127; 4367 result += t.tsym.flatName().hashCode(); 4368 for (Type s : t.getTypeArguments()) { 4369 result *= 127; 4370 result += visit(s); 4371 } 4372 return result; 4373 } 4374 4375 @Override 4376 public Integer visitMethodType(MethodType t, Void ignored) { 4377 int h = METHOD.ordinal(); 4378 for (List<Type> thisargs = t.argtypes; 4379 thisargs.tail != null; 4380 thisargs = thisargs.tail) 4381 h = (h << 5) + visit(thisargs.head); 4382 return (h << 5) + visit(t.restype); 4383 } 4384 4385 @Override 4386 public Integer visitWildcardType(WildcardType t, Void ignored) { 4387 int result = t.kind.hashCode(); 4388 if (t.type != null) { 4389 result *= 127; 4390 result += visit(t.type); 4391 } 4392 return result; 4393 } 4394 4395 @Override 4396 public Integer visitArrayType(ArrayType t, Void ignored) { 4397 return visit(t.elemtype) + 12; 4398 } 4399 4400 @Override 4401 public Integer visitTypeVar(TypeVar t, Void ignored) { 4402 return System.identityHashCode(t); 4403 } 4404 4405 @Override 4406 public Integer visitUndetVar(UndetVar t, Void ignored) { 4407 return System.identityHashCode(t); 4408 } 4409 4410 @Override 4411 public Integer visitErrorType(ErrorType t, Void ignored) { 4412 return 0; 4413 } 4414 } 4415 // </editor-fold> 4416 4417 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable"> 4418 /** 4419 * Does t have a result that is a subtype of the result type of s, 4420 * suitable for covariant returns? It is assumed that both types 4421 * are (possibly polymorphic) method types. Monomorphic method 4422 * types are handled in the obvious way. Polymorphic method types 4423 * require renaming all type variables of one to corresponding 4424 * type variables in the other, where correspondence is by 4425 * position in the type parameter list. */ 4426 public boolean resultSubtype(Type t, Type s, Warner warner) { 4427 List<Type> tvars = t.getTypeArguments(); 4428 List<Type> svars = s.getTypeArguments(); 4429 Type tres = t.getReturnType(); 4430 Type sres = subst(s.getReturnType(), svars, tvars); 4431 return covariantReturnType(tres, sres, warner); 4432 } 4433 4434 /** 4435 * Return-Type-Substitutable. 4436 * @jls 8.4.5 Method Result 4437 */ 4438 public boolean returnTypeSubstitutable(Type r1, Type r2) { 4439 if (hasSameArgs(r1, r2)) 4440 return resultSubtype(r1, r2, noWarnings); 4441 else 4442 return covariantReturnType(r1.getReturnType(), 4443 erasure(r2.getReturnType()), 4444 noWarnings); 4445 } 4446 4447 public boolean returnTypeSubstitutable(Type r1, 4448 Type r2, Type r2res, 4449 Warner warner) { 4450 if (isSameType(r1.getReturnType(), r2res)) 4451 return true; 4452 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive()) 4453 return false; 4454 4455 if (hasSameArgs(r1, r2)) 4456 return covariantReturnType(r1.getReturnType(), r2res, warner); 4457 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner)) 4458 return true; 4459 if (!isSubtype(r1.getReturnType(), erasure(r2res))) 4460 return false; 4461 warner.warn(LintCategory.UNCHECKED); 4462 return true; 4463 } 4464 4465 /** 4466 * Is t an appropriate return type in an overrider for a 4467 * method that returns s? 4468 */ 4469 public boolean covariantReturnType(Type t, Type s, Warner warner) { 4470 return 4471 isSameType(t, s) || 4472 !t.isPrimitive() && 4473 !s.isPrimitive() && 4474 isAssignable(t, s, warner); 4475 } 4476 // </editor-fold> 4477 4478 // <editor-fold defaultstate="collapsed" desc="Box/unbox support"> 4479 /** 4480 * Return the class that boxes the given primitive. 4481 */ 4482 public ClassSymbol boxedClass(Type t) { 4483 return syms.enterClass(syms.java_base, syms.boxedName[t.getTag().ordinal()]); 4484 } 4485 4486 /** 4487 * Return the boxed type if 't' is primitive, otherwise return 't' itself. 4488 */ 4489 public Type boxedTypeOrType(Type t) { 4490 return t.isPrimitive() ? 4491 boxedClass(t).type : 4492 t; 4493 } 4494 4495 /** 4496 * Return the primitive type corresponding to a boxed type. 4497 */ 4498 public Type unboxedType(Type t) { 4499 if (t.hasTag(ERROR)) 4500 return Type.noType; 4501 for (int i=0; i<syms.boxedName.length; i++) { 4502 Name box = syms.boxedName[i]; 4503 if (box != null && 4504 asSuper(t, syms.enterClass(syms.java_base, box)) != null) 4505 return syms.typeOfTag[i]; 4506 } 4507 return Type.noType; 4508 } 4509 4510 /** 4511 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself. 4512 */ 4513 public Type unboxedTypeOrType(Type t) { 4514 Type unboxedType = unboxedType(t); 4515 return unboxedType.hasTag(NONE) ? t : unboxedType; 4516 } 4517 // </editor-fold> 4518 4519 // <editor-fold defaultstate="collapsed" desc="Capture conversion"> 4520 /* 4521 * JLS 5.1.10 Capture Conversion: 4522 * 4523 * Let G name a generic type declaration with n formal type 4524 * parameters A1 ... An with corresponding bounds U1 ... Un. There 4525 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>, 4526 * where, for 1 <= i <= n: 4527 * 4528 * + If Ti is a wildcard type argument (4.5.1) of the form ? then 4529 * Si is a fresh type variable whose upper bound is 4530 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null 4531 * type. 4532 * 4533 * + If Ti is a wildcard type argument of the form ? extends Bi, 4534 * then Si is a fresh type variable whose upper bound is 4535 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is 4536 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is 4537 * a compile-time error if for any two classes (not interfaces) 4538 * Vi and Vj,Vi is not a subclass of Vj or vice versa. 4539 * 4540 * + If Ti is a wildcard type argument of the form ? super Bi, 4541 * then Si is a fresh type variable whose upper bound is 4542 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi. 4543 * 4544 * + Otherwise, Si = Ti. 4545 * 4546 * Capture conversion on any type other than a parameterized type 4547 * (4.5) acts as an identity conversion (5.1.1). Capture 4548 * conversions never require a special action at run time and 4549 * therefore never throw an exception at run time. 4550 * 4551 * Capture conversion is not applied recursively. 4552 */ 4553 /** 4554 * Capture conversion as specified by the JLS. 4555 */ 4556 4557 public List<Type> capture(List<Type> ts) { 4558 List<Type> buf = List.nil(); 4559 for (Type t : ts) { 4560 buf = buf.prepend(capture(t)); 4561 } 4562 return buf.reverse(); 4563 } 4564 4565 public Type capture(Type t) { 4566 if (!t.hasTag(CLASS)) { 4567 return t; 4568 } 4569 if (t.getEnclosingType() != Type.noType) { 4570 Type capturedEncl = capture(t.getEnclosingType()); 4571 if (capturedEncl != t.getEnclosingType()) { 4572 Type type1 = memberType(capturedEncl, t.tsym); 4573 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments()); 4574 } 4575 } 4576 ClassType cls = (ClassType)t; 4577 if (cls.isRaw() || !cls.isParameterized()) 4578 return cls; 4579 4580 ClassType G = (ClassType)cls.asElement().asType(); 4581 List<Type> A = G.getTypeArguments(); 4582 List<Type> T = cls.getTypeArguments(); 4583 List<Type> S = freshTypeVariables(T); 4584 4585 List<Type> currentA = A; 4586 List<Type> currentT = T; 4587 List<Type> currentS = S; 4588 boolean captured = false; 4589 while (!currentA.isEmpty() && 4590 !currentT.isEmpty() && 4591 !currentS.isEmpty()) { 4592 if (currentS.head != currentT.head) { 4593 captured = true; 4594 WildcardType Ti = (WildcardType)currentT.head; 4595 Type Ui = currentA.head.getUpperBound(); 4596 CapturedType Si = (CapturedType)currentS.head; 4597 if (Ui == null) 4598 Ui = syms.objectType; 4599 switch (Ti.kind) { 4600 case UNBOUND: 4601 Si.setUpperBound( subst(Ui, A, S) ); 4602 Si.lower = syms.botType; 4603 break; 4604 case EXTENDS: 4605 Si.setUpperBound( glb(Ti.getExtendsBound(), subst(Ui, A, S)) ); 4606 Si.lower = syms.botType; 4607 break; 4608 case SUPER: 4609 Si.setUpperBound( subst(Ui, A, S) ); 4610 Si.lower = Ti.getSuperBound(); 4611 break; 4612 } 4613 Type tmpBound = Si.getUpperBound().hasTag(UNDETVAR) ? ((UndetVar)Si.getUpperBound()).qtype : Si.getUpperBound(); 4614 Type tmpLower = Si.lower.hasTag(UNDETVAR) ? ((UndetVar)Si.lower).qtype : Si.lower; 4615 if (!Si.getUpperBound().hasTag(ERROR) && 4616 !Si.lower.hasTag(ERROR) && 4617 isSameType(tmpBound, tmpLower)) { 4618 currentS.head = Si.getUpperBound(); 4619 } 4620 } 4621 currentA = currentA.tail; 4622 currentT = currentT.tail; 4623 currentS = currentS.tail; 4624 } 4625 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty()) 4626 return erasure(t); // some "rare" type involved 4627 4628 if (captured) 4629 return new ClassType(cls.getEnclosingType(), S, cls.tsym, 4630 cls.getMetadata(), cls.getFlavor()); 4631 else 4632 return t; 4633 } 4634 // where 4635 public List<Type> freshTypeVariables(List<Type> types) { 4636 ListBuffer<Type> result = new ListBuffer<>(); 4637 for (Type t : types) { 4638 if (t.hasTag(WILDCARD)) { 4639 Type bound = ((WildcardType)t).getExtendsBound(); 4640 if (bound == null) 4641 bound = syms.objectType; 4642 result.append(new CapturedType(capturedName, 4643 syms.noSymbol, 4644 bound, 4645 syms.botType, 4646 (WildcardType)t)); 4647 } else { 4648 result.append(t); 4649 } 4650 } 4651 return result.toList(); 4652 } 4653 // </editor-fold> 4654 4655 // <editor-fold defaultstate="collapsed" desc="Internal utility methods"> 4656 private boolean sideCast(Type from, Type to, Warner warn) { 4657 // We are casting from type $from$ to type $to$, which are 4658 // non-final unrelated types. This method 4659 // tries to reject a cast by transferring type parameters 4660 // from $to$ to $from$ by common superinterfaces. 4661 boolean reverse = false; 4662 Type target = to; 4663 if ((to.tsym.flags() & INTERFACE) == 0) { 4664 Assert.check((from.tsym.flags() & INTERFACE) != 0); 4665 reverse = true; 4666 to = from; 4667 from = target; 4668 } 4669 List<Type> commonSupers = superClosure(to, erasure(from)); 4670 boolean giveWarning = commonSupers.isEmpty(); 4671 // The arguments to the supers could be unified here to 4672 // get a more accurate analysis 4673 while (commonSupers.nonEmpty()) { 4674 Type t1 = asSuper(from, commonSupers.head.tsym); 4675 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym); 4676 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) 4677 return false; 4678 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)); 4679 commonSupers = commonSupers.tail; 4680 } 4681 if (giveWarning && !isReifiable(reverse ? from : to)) 4682 warn.warn(LintCategory.UNCHECKED); 4683 return true; 4684 } 4685 4686 private boolean sideCastFinal(Type from, Type to, Warner warn) { 4687 // We are casting from type $from$ to type $to$, which are 4688 // unrelated types one of which is final and the other of 4689 // which is an interface. This method 4690 // tries to reject a cast by transferring type parameters 4691 // from the final class to the interface. 4692 boolean reverse = false; 4693 Type target = to; 4694 if ((to.tsym.flags() & INTERFACE) == 0) { 4695 Assert.check((from.tsym.flags() & INTERFACE) != 0); 4696 reverse = true; 4697 to = from; 4698 from = target; 4699 } 4700 Assert.check((from.tsym.flags() & FINAL) != 0); 4701 Type t1 = asSuper(from, to.tsym); 4702 if (t1 == null) return false; 4703 Type t2 = to; 4704 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) 4705 return false; 4706 if (!isReifiable(target) && 4707 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2))) 4708 warn.warn(LintCategory.UNCHECKED); 4709 return true; 4710 } 4711 4712 private boolean giveWarning(Type from, Type to) { 4713 List<Type> bounds = to.isCompound() ? 4714 directSupertypes(to) : List.of(to); 4715 for (Type b : bounds) { 4716 Type subFrom = asSub(from, b.tsym); 4717 if (b.isParameterized() && 4718 (!(isUnbounded(b) || 4719 isSubtype(from, b) || 4720 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) { 4721 return true; 4722 } 4723 } 4724 return false; 4725 } 4726 4727 private List<Type> superClosure(Type t, Type s) { 4728 List<Type> cl = List.nil(); 4729 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { 4730 if (isSubtype(s, erasure(l.head))) { 4731 cl = insert(cl, l.head); 4732 } else { 4733 cl = union(cl, superClosure(l.head, s)); 4734 } 4735 } 4736 return cl; 4737 } 4738 4739 private boolean containsTypeEquivalent(Type t, Type s) { 4740 return isSameType(t, s) || // shortcut 4741 containsType(t, s) && containsType(s, t); 4742 } 4743 4744 // <editor-fold defaultstate="collapsed" desc="adapt"> 4745 /** 4746 * Adapt a type by computing a substitution which maps a source 4747 * type to a target type. 4748 * 4749 * @param source the source type 4750 * @param target the target type 4751 * @param from the type variables of the computed substitution 4752 * @param to the types of the computed substitution. 4753 */ 4754 public void adapt(Type source, 4755 Type target, 4756 ListBuffer<Type> from, 4757 ListBuffer<Type> to) throws AdaptFailure { 4758 new Adapter(from, to).adapt(source, target); 4759 } 4760 4761 class Adapter extends SimpleVisitor<Void, Type> { 4762 4763 ListBuffer<Type> from; 4764 ListBuffer<Type> to; 4765 Map<Symbol,Type> mapping; 4766 4767 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) { 4768 this.from = from; 4769 this.to = to; 4770 mapping = new HashMap<>(); 4771 } 4772 4773 public void adapt(Type source, Type target) throws AdaptFailure { 4774 visit(source, target); 4775 List<Type> fromList = from.toList(); 4776 List<Type> toList = to.toList(); 4777 while (!fromList.isEmpty()) { 4778 Type val = mapping.get(fromList.head.tsym); 4779 if (toList.head != val) 4780 toList.head = val; 4781 fromList = fromList.tail; 4782 toList = toList.tail; 4783 } 4784 } 4785 4786 @Override 4787 public Void visitClassType(ClassType source, Type target) throws AdaptFailure { 4788 if (target.hasTag(CLASS)) 4789 adaptRecursive(source.allparams(), target.allparams()); 4790 return null; 4791 } 4792 4793 @Override 4794 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure { 4795 if (target.hasTag(ARRAY)) 4796 adaptRecursive(elemtype(source), elemtype(target)); 4797 return null; 4798 } 4799 4800 @Override 4801 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure { 4802 if (source.isExtendsBound()) 4803 adaptRecursive(wildUpperBound(source), wildUpperBound(target)); 4804 else if (source.isSuperBound()) 4805 adaptRecursive(wildLowerBound(source), wildLowerBound(target)); 4806 return null; 4807 } 4808 4809 @Override 4810 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure { 4811 // Check to see if there is 4812 // already a mapping for $source$, in which case 4813 // the old mapping will be merged with the new 4814 Type val = mapping.get(source.tsym); 4815 if (val != null) { 4816 if (val.isSuperBound() && target.isSuperBound()) { 4817 val = isSubtype(wildLowerBound(val), wildLowerBound(target)) 4818 ? target : val; 4819 } else if (val.isExtendsBound() && target.isExtendsBound()) { 4820 val = isSubtype(wildUpperBound(val), wildUpperBound(target)) 4821 ? val : target; 4822 } else if (!isSameType(val, target)) { 4823 throw new AdaptFailure(); 4824 } 4825 } else { 4826 val = target; 4827 from.append(source); 4828 to.append(target); 4829 } 4830 mapping.put(source.tsym, val); 4831 return null; 4832 } 4833 4834 @Override 4835 public Void visitType(Type source, Type target) { 4836 return null; 4837 } 4838 4839 private Set<TypePair> cache = new HashSet<>(); 4840 4841 private void adaptRecursive(Type source, Type target) { 4842 TypePair pair = new TypePair(source, target); 4843 if (cache.add(pair)) { 4844 try { 4845 visit(source, target); 4846 } finally { 4847 cache.remove(pair); 4848 } 4849 } 4850 } 4851 4852 private void adaptRecursive(List<Type> source, List<Type> target) { 4853 if (source.length() == target.length()) { 4854 while (source.nonEmpty()) { 4855 adaptRecursive(source.head, target.head); 4856 source = source.tail; 4857 target = target.tail; 4858 } 4859 } 4860 } 4861 } 4862 4863 public static class AdaptFailure extends RuntimeException { 4864 static final long serialVersionUID = -7490231548272701566L; 4865 } 4866 4867 private void adaptSelf(Type t, 4868 ListBuffer<Type> from, 4869 ListBuffer<Type> to) { 4870 try { 4871 //if (t.tsym.type != t) 4872 adapt(t.tsym.type, t, from, to); 4873 } catch (AdaptFailure ex) { 4874 // Adapt should never fail calculating a mapping from 4875 // t.tsym.type to t as there can be no merge problem. 4876 throw new AssertionError(ex); 4877 } 4878 } 4879 // </editor-fold> 4880 4881 /** 4882 * Rewrite all type variables (universal quantifiers) in the given 4883 * type to wildcards (existential quantifiers). This is used to 4884 * determine if a cast is allowed. For example, if high is true 4885 * and {@code T <: Number}, then {@code List<T>} is rewritten to 4886 * {@code List<? extends Number>}. Since {@code List<Integer> <: 4887 * List<? extends Number>} a {@code List<T>} can be cast to {@code 4888 * List<Integer>} with a warning. 4889 * @param t a type 4890 * @param high if true return an upper bound; otherwise a lower 4891 * bound 4892 * @param rewriteTypeVars only rewrite captured wildcards if false; 4893 * otherwise rewrite all type variables 4894 * @return the type rewritten with wildcards (existential 4895 * quantifiers) only 4896 */ 4897 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) { 4898 return new Rewriter(high, rewriteTypeVars).visit(t); 4899 } 4900 4901 class Rewriter extends UnaryVisitor<Type> { 4902 4903 boolean high; 4904 boolean rewriteTypeVars; 4905 4906 Rewriter(boolean high, boolean rewriteTypeVars) { 4907 this.high = high; 4908 this.rewriteTypeVars = rewriteTypeVars; 4909 } 4910 4911 @Override 4912 public Type visitClassType(ClassType t, Void s) { 4913 ListBuffer<Type> rewritten = new ListBuffer<>(); 4914 boolean changed = false; 4915 for (Type arg : t.allparams()) { 4916 Type bound = visit(arg); 4917 if (arg != bound) { 4918 changed = true; 4919 } 4920 rewritten.append(bound); 4921 } 4922 if (changed) 4923 return subst(t.tsym.type, 4924 t.tsym.type.allparams(), 4925 rewritten.toList()); 4926 else 4927 return t; 4928 } 4929 4930 public Type visitType(Type t, Void s) { 4931 return t; 4932 } 4933 4934 @Override 4935 public Type visitCapturedType(CapturedType t, Void s) { 4936 Type w_bound = t.wildcard.type; 4937 Type bound = w_bound.contains(t) ? 4938 erasure(w_bound) : 4939 visit(w_bound); 4940 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind); 4941 } 4942 4943 @Override 4944 public Type visitTypeVar(TypeVar t, Void s) { 4945 if (rewriteTypeVars) { 4946 Type bound = t.getUpperBound().contains(t) ? 4947 erasure(t.getUpperBound()) : 4948 visit(t.getUpperBound()); 4949 return rewriteAsWildcardType(bound, t, EXTENDS); 4950 } else { 4951 return t; 4952 } 4953 } 4954 4955 @Override 4956 public Type visitWildcardType(WildcardType t, Void s) { 4957 Type bound2 = visit(t.type); 4958 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind); 4959 } 4960 4961 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) { 4962 switch (bk) { 4963 case EXTENDS: return high ? 4964 makeExtendsWildcard(B(bound), formal) : 4965 makeExtendsWildcard(syms.objectType, formal); 4966 case SUPER: return high ? 4967 makeSuperWildcard(syms.botType, formal) : 4968 makeSuperWildcard(B(bound), formal); 4969 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal); 4970 default: 4971 Assert.error("Invalid bound kind " + bk); 4972 return null; 4973 } 4974 } 4975 4976 Type B(Type t) { 4977 while (t.hasTag(WILDCARD)) { 4978 WildcardType w = (WildcardType)t; 4979 t = high ? 4980 w.getExtendsBound() : 4981 w.getSuperBound(); 4982 if (t == null) { 4983 t = high ? syms.objectType : syms.botType; 4984 } 4985 } 4986 return t; 4987 } 4988 } 4989 4990 4991 /** 4992 * Create a wildcard with the given upper (extends) bound; create 4993 * an unbounded wildcard if bound is Object. 4994 * 4995 * @param bound the upper bound 4996 * @param formal the formal type parameter that will be 4997 * substituted by the wildcard 4998 */ 4999 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) { 5000 if (bound == syms.objectType) { 5001 return new WildcardType(syms.objectType, 5002 BoundKind.UNBOUND, 5003 syms.boundClass, 5004 formal); 5005 } else { 5006 return new WildcardType(bound, 5007 BoundKind.EXTENDS, 5008 syms.boundClass, 5009 formal); 5010 } 5011 } 5012 5013 /** 5014 * Create a wildcard with the given lower (super) bound; create an 5015 * unbounded wildcard if bound is bottom (type of {@code null}). 5016 * 5017 * @param bound the lower bound 5018 * @param formal the formal type parameter that will be 5019 * substituted by the wildcard 5020 */ 5021 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) { 5022 if (bound.hasTag(BOT)) { 5023 return new WildcardType(syms.objectType, 5024 BoundKind.UNBOUND, 5025 syms.boundClass, 5026 formal); 5027 } else { 5028 return new WildcardType(bound, 5029 BoundKind.SUPER, 5030 syms.boundClass, 5031 formal); 5032 } 5033 } 5034 5035 /** 5036 * A wrapper for a type that allows use in sets. 5037 */ 5038 public static class UniqueType { 5039 public final Type type; 5040 final Types types; 5041 private boolean encodeTypeSig; 5042 5043 public UniqueType(Type type, Types types, boolean encodeTypeSig) { 5044 this.type = type; 5045 this.types = types; 5046 this.encodeTypeSig = encodeTypeSig; 5047 } 5048 5049 public UniqueType(Type type, Types types) { 5050 this(type, types, true); 5051 } 5052 5053 public int hashCode() { 5054 return types.hashCode(type); 5055 } 5056 5057 public boolean equals(Object obj) { 5058 return (obj instanceof UniqueType uniqueType) && 5059 types.isSameType(type, uniqueType.type); 5060 } 5061 5062 public boolean encodeTypeSig() { 5063 return encodeTypeSig; 5064 } 5065 5066 public String toString() { 5067 return type.toString(); 5068 } 5069 5070 } 5071 // </editor-fold> 5072 5073 // <editor-fold defaultstate="collapsed" desc="Visitors"> 5074 /** 5075 * A default visitor for types. All visitor methods except 5076 * visitType are implemented by delegating to visitType. Concrete 5077 * subclasses must provide an implementation of visitType and can 5078 * override other methods as needed. 5079 * 5080 * @param <R> the return type of the operation implemented by this 5081 * visitor; use Void if no return type is needed. 5082 * @param <S> the type of the second argument (the first being the 5083 * type itself) of the operation implemented by this visitor; use 5084 * Void if a second argument is not needed. 5085 */ 5086 public abstract static class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> { 5087 public final R visit(Type t, S s) { return t.accept(this, s); } 5088 public R visitClassType(ClassType t, S s) { return visitType(t, s); } 5089 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); } 5090 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); } 5091 public R visitMethodType(MethodType t, S s) { return visitType(t, s); } 5092 public R visitPackageType(PackageType t, S s) { return visitType(t, s); } 5093 public R visitModuleType(ModuleType t, S s) { return visitType(t, s); } 5094 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); } 5095 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); } 5096 public R visitForAll(ForAll t, S s) { return visitType(t, s); } 5097 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); } 5098 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); } 5099 } 5100 5101 /** 5102 * A default visitor for symbols. All visitor methods except 5103 * visitSymbol are implemented by delegating to visitSymbol. Concrete 5104 * subclasses must provide an implementation of visitSymbol and can 5105 * override other methods as needed. 5106 * 5107 * @param <R> the return type of the operation implemented by this 5108 * visitor; use Void if no return type is needed. 5109 * @param <S> the type of the second argument (the first being the 5110 * symbol itself) of the operation implemented by this visitor; use 5111 * Void if a second argument is not needed. 5112 */ 5113 public abstract static class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> { 5114 public final R visit(Symbol s, S arg) { return s.accept(this, arg); } 5115 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); } 5116 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); } 5117 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); } 5118 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); } 5119 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); } 5120 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); } 5121 } 5122 5123 /** 5124 * A <em>simple</em> visitor for types. This visitor is simple as 5125 * captured wildcards, for-all types (generic methods), and 5126 * undetermined type variables (part of inference) are hidden. 5127 * Captured wildcards are hidden by treating them as type 5128 * variables and the rest are hidden by visiting their qtypes. 5129 * 5130 * @param <R> the return type of the operation implemented by this 5131 * visitor; use Void if no return type is needed. 5132 * @param <S> the type of the second argument (the first being the 5133 * type itself) of the operation implemented by this visitor; use 5134 * Void if a second argument is not needed. 5135 */ 5136 public abstract static class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> { 5137 @Override 5138 public R visitCapturedType(CapturedType t, S s) { 5139 return visitTypeVar(t, s); 5140 } 5141 @Override 5142 public R visitForAll(ForAll t, S s) { 5143 return visit(t.qtype, s); 5144 } 5145 @Override 5146 public R visitUndetVar(UndetVar t, S s) { 5147 return visit(t.qtype, s); 5148 } 5149 } 5150 5151 /** 5152 * A plain relation on types. That is a 2-ary function on the 5153 * form Type × Type → Boolean. 5154 * <!-- In plain text: Type x Type -> Boolean --> 5155 */ 5156 public abstract static class TypeRelation extends SimpleVisitor<Boolean,Type> {} 5157 5158 /** 5159 * A convenience visitor for implementing operations that only 5160 * require one argument (the type itself), that is, unary 5161 * operations. 5162 * 5163 * @param <R> the return type of the operation implemented by this 5164 * visitor; use Void if no return type is needed. 5165 */ 5166 public abstract static class UnaryVisitor<R> extends SimpleVisitor<R,Void> { 5167 public final R visit(Type t) { return t.accept(this, null); } 5168 } 5169 5170 /** 5171 * A visitor for implementing a mapping from types to types. The 5172 * default behavior of this class is to implement the identity 5173 * mapping (mapping a type to itself). This can be overridden in 5174 * subclasses. 5175 * 5176 * @param <S> the type of the second argument (the first being the 5177 * type itself) of this mapping; use Void if a second argument is 5178 * not needed. 5179 */ 5180 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> { 5181 public final Type visit(Type t) { return t.accept(this, null); } 5182 public Type visitType(Type t, S s) { return t; } 5183 } 5184 5185 /** 5186 * An abstract class for mappings from types to types (see {@link Type#map(TypeMapping)}. 5187 * This class implements the functional interface {@code Function}, that allows it to be used 5188 * fluently in stream-like processing. 5189 */ 5190 public static class TypeMapping<S> extends MapVisitor<S> implements Function<Type, Type> { 5191 @Override 5192 public Type apply(Type type) { return visit(type); } 5193 5194 List<Type> visit(List<Type> ts, S s) { 5195 return ts.map(t -> visit(t, s)); 5196 } 5197 5198 @Override 5199 public Type visitCapturedType(CapturedType t, S s) { 5200 return visitTypeVar(t, s); 5201 } 5202 } 5203 // </editor-fold> 5204 5205 5206 // <editor-fold defaultstate="collapsed" desc="Annotation support"> 5207 5208 public RetentionPolicy getRetention(Attribute.Compound a) { 5209 return getRetention(a.type.tsym); 5210 } 5211 5212 public RetentionPolicy getRetention(TypeSymbol sym) { 5213 RetentionPolicy vis = RetentionPolicy.CLASS; // the default 5214 Attribute.Compound c = sym.attribute(syms.retentionType.tsym); 5215 if (c != null) { 5216 Attribute value = c.member(names.value); 5217 if (value != null && value instanceof Attribute.Enum attributeEnum) { 5218 Name levelName = attributeEnum.value.name; 5219 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE; 5220 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS; 5221 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME; 5222 else ;// /* fail soft */ throw new AssertionError(levelName); 5223 } 5224 } 5225 return vis; 5226 } 5227 // </editor-fold> 5228 5229 // <editor-fold defaultstate="collapsed" desc="Signature Generation"> 5230 5231 public abstract static class SignatureGenerator { 5232 5233 public static class InvalidSignatureException extends RuntimeException { 5234 private static final long serialVersionUID = 0; 5235 5236 private final transient Type type; 5237 5238 InvalidSignatureException(Type type) { 5239 this.type = type; 5240 } 5241 5242 public Type type() { 5243 return type; 5244 } 5245 5246 @Override 5247 public Throwable fillInStackTrace() { 5248 // This is an internal exception; the stack trace is irrelevant. 5249 return this; 5250 } 5251 } 5252 5253 private final Types types; 5254 5255 protected abstract void append(char ch); 5256 protected abstract void append(byte[] ba); 5257 protected abstract void append(Name name); 5258 protected void classReference(ClassSymbol c) { /* by default: no-op */ } 5259 5260 protected SignatureGenerator(Types types) { 5261 this.types = types; 5262 } 5263 5264 protected void reportIllegalSignature(Type t) { 5265 throw new InvalidSignatureException(t); 5266 } 5267 5268 /** 5269 * Assemble signature of given type in string buffer. 5270 */ 5271 public void assembleSig(Type type) { 5272 switch (type.getTag()) { 5273 case BYTE: 5274 append('B'); 5275 break; 5276 case SHORT: 5277 append('S'); 5278 break; 5279 case CHAR: 5280 append('C'); 5281 break; 5282 case INT: 5283 append('I'); 5284 break; 5285 case LONG: 5286 append('J'); 5287 break; 5288 case FLOAT: 5289 append('F'); 5290 break; 5291 case DOUBLE: 5292 append('D'); 5293 break; 5294 case BOOLEAN: 5295 append('Z'); 5296 break; 5297 case VOID: 5298 append('V'); 5299 break; 5300 case CLASS: 5301 if (type.isCompound()) { 5302 reportIllegalSignature(type); 5303 } 5304 if (types.allowPrimitiveClasses && type.isPrimitiveClass()) 5305 append('Q'); 5306 else 5307 append('L'); 5308 assembleClassSig(type); 5309 append(';'); 5310 break; 5311 case ARRAY: 5312 ArrayType at = (ArrayType) type; 5313 append('['); 5314 assembleSig(at.elemtype); 5315 break; 5316 case METHOD: 5317 MethodType mt = (MethodType) type; 5318 append('('); 5319 assembleSig(mt.argtypes); 5320 append(')'); 5321 assembleSig(mt.restype); 5322 if (hasTypeVar(mt.thrown)) { 5323 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) { 5324 append('^'); 5325 assembleSig(l.head); 5326 } 5327 } 5328 break; 5329 case WILDCARD: { 5330 Type.WildcardType ta = (Type.WildcardType) type; 5331 switch (ta.kind) { 5332 case SUPER: 5333 append('-'); 5334 assembleSig(ta.type); 5335 break; 5336 case EXTENDS: 5337 append('+'); 5338 assembleSig(ta.type); 5339 break; 5340 case UNBOUND: 5341 append('*'); 5342 break; 5343 default: 5344 throw new AssertionError(ta.kind); 5345 } 5346 break; 5347 } 5348 case TYPEVAR: 5349 if (((TypeVar)type).isCaptured()) { 5350 reportIllegalSignature(type); 5351 } 5352 append('T'); 5353 append(type.tsym.name); 5354 append(';'); 5355 break; 5356 case FORALL: 5357 Type.ForAll ft = (Type.ForAll) type; 5358 assembleParamsSig(ft.tvars); 5359 assembleSig(ft.qtype); 5360 break; 5361 default: 5362 throw new AssertionError("typeSig " + type.getTag()); 5363 } 5364 } 5365 5366 public boolean hasTypeVar(List<Type> l) { 5367 while (l.nonEmpty()) { 5368 if (l.head.hasTag(TypeTag.TYPEVAR)) { 5369 return true; 5370 } 5371 l = l.tail; 5372 } 5373 return false; 5374 } 5375 5376 public void assembleClassSig(Type type) { 5377 ClassType ct = (ClassType) type; 5378 ClassSymbol c = (ClassSymbol) ct.tsym; 5379 classReference(c); 5380 Type outer = ct.getEnclosingType(); 5381 if (outer.allparams().nonEmpty()) { 5382 boolean rawOuter = 5383 c.owner.kind == MTH || // either a local class 5384 c.name == types.names.empty; // or anonymous 5385 assembleClassSig(rawOuter 5386 ? types.erasure(outer) 5387 : outer); 5388 append(rawOuter ? '$' : '.'); 5389 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname)); 5390 append(rawOuter 5391 ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength()) 5392 : c.name); 5393 } else { 5394 append(externalize(c.flatname)); 5395 } 5396 if (ct.getTypeArguments().nonEmpty()) { 5397 append('<'); 5398 assembleSig(ct.getTypeArguments()); 5399 append('>'); 5400 } 5401 } 5402 5403 public void assembleParamsSig(List<Type> typarams) { 5404 append('<'); 5405 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) { 5406 Type.TypeVar tvar = (Type.TypeVar) ts.head; 5407 append(tvar.tsym.name); 5408 List<Type> bounds = types.getBounds(tvar); 5409 if ((bounds.head.tsym.flags() & INTERFACE) != 0) { 5410 append(':'); 5411 } 5412 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) { 5413 append(':'); 5414 assembleSig(l.head); 5415 } 5416 } 5417 append('>'); 5418 } 5419 5420 public void assembleSig(List<Type> types) { 5421 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) { 5422 assembleSig(ts.head); 5423 } 5424 } 5425 } 5426 5427 public Type constantType(LoadableConstant c) { 5428 switch (c.poolTag()) { 5429 case ClassFile.CONSTANT_Class: 5430 return syms.classType; 5431 case ClassFile.CONSTANT_String: 5432 return syms.stringType; 5433 case ClassFile.CONSTANT_Integer: 5434 return syms.intType; 5435 case ClassFile.CONSTANT_Float: 5436 return syms.floatType; 5437 case ClassFile.CONSTANT_Long: 5438 return syms.longType; 5439 case ClassFile.CONSTANT_Double: 5440 return syms.doubleType; 5441 case ClassFile.CONSTANT_MethodHandle: 5442 return syms.methodHandleType; 5443 case ClassFile.CONSTANT_MethodType: 5444 return syms.methodTypeType; 5445 case ClassFile.CONSTANT_Dynamic: 5446 return ((DynamicVarSymbol)c).type; 5447 default: 5448 throw new AssertionError("Not a loadable constant: " + c.poolTag()); 5449 } 5450 } 5451 // </editor-fold> 5452 5453 public void newRound() { 5454 descCache._map.clear(); 5455 isDerivedRawCache.clear(); 5456 implCache._map.clear(); 5457 membersCache._map.clear(); 5458 closureCache.clear(); 5459 } 5460 }