Types.java revision 3158:aae35f1ac70b
1/* 2 * Copyright (c) 2003, 2015, 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 26package com.sun.tools.javac.code; 27 28import java.lang.ref.SoftReference; 29import java.util.HashSet; 30import java.util.HashMap; 31import java.util.Locale; 32import java.util.Map; 33import java.util.Set; 34import java.util.WeakHashMap; 35import java.util.function.BiPredicate; 36import java.util.stream.Collector; 37 38import javax.tools.JavaFileObject; 39 40import com.sun.tools.javac.code.Attribute.RetentionPolicy; 41import com.sun.tools.javac.code.Lint.LintCategory; 42import com.sun.tools.javac.code.Type.UndetVar.InferenceBound; 43import com.sun.tools.javac.code.TypeMetadata.Entry.Kind; 44import com.sun.tools.javac.comp.AttrContext; 45import com.sun.tools.javac.comp.Check; 46import com.sun.tools.javac.comp.Enter; 47import com.sun.tools.javac.comp.Env; 48import com.sun.tools.javac.util.*; 49 50import static com.sun.tools.javac.code.BoundKind.*; 51import static com.sun.tools.javac.code.Flags.*; 52import static com.sun.tools.javac.code.Kinds.Kind.*; 53import static com.sun.tools.javac.code.Scope.*; 54import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 55import static com.sun.tools.javac.code.Symbol.*; 56import static com.sun.tools.javac.code.Type.*; 57import static com.sun.tools.javac.code.TypeTag.*; 58import static com.sun.tools.javac.jvm.ClassFile.externalize; 59 60/** 61 * Utility class containing various operations on types. 62 * 63 * <p>Unless other names are more illustrative, the following naming 64 * conventions should be observed in this file: 65 * 66 * <dl> 67 * <dt>t</dt> 68 * <dd>If the first argument to an operation is a type, it should be named t.</dd> 69 * <dt>s</dt> 70 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd> 71 * <dt>ts</dt> 72 * <dd>If an operations takes a list of types, the first should be named ts.</dd> 73 * <dt>ss</dt> 74 * <dd>A second list of types should be named ss.</dd> 75 * </dl> 76 * 77 * <p><b>This is NOT part of any supported API. 78 * If you write code that depends on this, you do so at your own risk. 79 * This code and its internal interfaces are subject to change or 80 * deletion without notice.</b> 81 */ 82public class Types { 83 protected static final Context.Key<Types> typesKey = new Context.Key<>(); 84 85 final Symtab syms; 86 final JavacMessages messages; 87 final Names names; 88 final boolean allowObjectToPrimitiveCast; 89 final boolean allowDefaultMethods; 90 final Check chk; 91 final Enter enter; 92 JCDiagnostic.Factory diags; 93 List<Warner> warnStack = List.nil(); 94 final Name capturedName; 95 private final FunctionDescriptorLookupError functionDescriptorLookupError; 96 97 public final Warner noWarnings; 98 99 // <editor-fold defaultstate="collapsed" desc="Instantiating"> 100 public static Types instance(Context context) { 101 Types instance = context.get(typesKey); 102 if (instance == null) 103 instance = new Types(context); 104 return instance; 105 } 106 107 protected Types(Context context) { 108 context.put(typesKey, this); 109 syms = Symtab.instance(context); 110 names = Names.instance(context); 111 Source source = Source.instance(context); 112 allowObjectToPrimitiveCast = source.allowObjectToPrimitiveCast(); 113 allowDefaultMethods = source.allowDefaultMethods(); 114 chk = Check.instance(context); 115 enter = Enter.instance(context); 116 capturedName = names.fromString("<captured wildcard>"); 117 messages = JavacMessages.instance(context); 118 diags = JCDiagnostic.Factory.instance(context); 119 functionDescriptorLookupError = new FunctionDescriptorLookupError(); 120 noWarnings = new Warner(null); 121 } 122 // </editor-fold> 123 124 // <editor-fold defaultstate="collapsed" desc="bounds"> 125 /** 126 * Get a wildcard's upper bound, returning non-wildcards unchanged. 127 * @param t a type argument, either a wildcard or a type 128 */ 129 public Type wildUpperBound(Type t) { 130 if (t.hasTag(WILDCARD)) { 131 WildcardType w = (WildcardType) t; 132 if (w.isSuperBound()) 133 return w.bound == null ? syms.objectType : w.bound.bound; 134 else 135 return wildUpperBound(w.type); 136 } 137 else return t; 138 } 139 140 /** 141 * Get a capture variable's upper bound, returning other types unchanged. 142 * @param t a type 143 */ 144 public Type cvarUpperBound(Type t) { 145 if (t.hasTag(TYPEVAR)) { 146 TypeVar v = (TypeVar) t; 147 return v.isCaptured() ? cvarUpperBound(v.bound) : v; 148 } 149 else return t; 150 } 151 152 /** 153 * Get a wildcard's lower bound, returning non-wildcards unchanged. 154 * @param t a type argument, either a wildcard or a type 155 */ 156 public Type wildLowerBound(Type t) { 157 if (t.hasTag(WILDCARD)) { 158 WildcardType w = (WildcardType) t; 159 return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type); 160 } 161 else return t; 162 } 163 164 /** 165 * Get a capture variable's lower bound, returning other types unchanged. 166 * @param t a type 167 */ 168 public Type cvarLowerBound(Type t) { 169 if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) { 170 return cvarLowerBound(t.getLowerBound()); 171 } 172 else return t; 173 } 174 175 /** 176 * Recursively skip type-variables until a class/array type is found; capture conversion is then 177 * (optionally) applied to the resulting type. This is useful for i.e. computing a site that is 178 * suitable for a method lookup. 179 */ 180 public Type skipTypeVars(Type site, boolean capture) { 181 while (site.hasTag(TYPEVAR)) { 182 site = site.getUpperBound(); 183 } 184 return capture ? capture(site) : site; 185 } 186 // </editor-fold> 187 188 // <editor-fold defaultstate="collapsed" desc="isUnbounded"> 189 /** 190 * Checks that all the arguments to a class are unbounded 191 * wildcards or something else that doesn't make any restrictions 192 * on the arguments. If a class isUnbounded, a raw super- or 193 * subclass can be cast to it without a warning. 194 * @param t a type 195 * @return true iff the given type is unbounded or raw 196 */ 197 public boolean isUnbounded(Type t) { 198 return isUnbounded.visit(t); 199 } 200 // where 201 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() { 202 203 public Boolean visitType(Type t, Void ignored) { 204 return true; 205 } 206 207 @Override 208 public Boolean visitClassType(ClassType t, Void ignored) { 209 List<Type> parms = t.tsym.type.allparams(); 210 List<Type> args = t.allparams(); 211 while (parms.nonEmpty()) { 212 WildcardType unb = new WildcardType(syms.objectType, 213 BoundKind.UNBOUND, 214 syms.boundClass, 215 (TypeVar)parms.head); 216 if (!containsType(args.head, unb)) 217 return false; 218 parms = parms.tail; 219 args = args.tail; 220 } 221 return true; 222 } 223 }; 224 // </editor-fold> 225 226 // <editor-fold defaultstate="collapsed" desc="asSub"> 227 /** 228 * Return the least specific subtype of t that starts with symbol 229 * sym. If none exists, return null. The least specific subtype 230 * is determined as follows: 231 * 232 * <p>If there is exactly one parameterized instance of sym that is a 233 * subtype of t, that parameterized instance is returned.<br> 234 * Otherwise, if the plain type or raw type `sym' is a subtype of 235 * type t, the type `sym' itself is returned. Otherwise, null is 236 * returned. 237 */ 238 public Type asSub(Type t, Symbol sym) { 239 return asSub.visit(t, sym); 240 } 241 // where 242 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() { 243 244 public Type visitType(Type t, Symbol sym) { 245 return null; 246 } 247 248 @Override 249 public Type visitClassType(ClassType t, Symbol sym) { 250 if (t.tsym == sym) 251 return t; 252 Type base = asSuper(sym.type, t.tsym); 253 if (base == null) 254 return null; 255 ListBuffer<Type> from = new ListBuffer<>(); 256 ListBuffer<Type> to = new ListBuffer<>(); 257 try { 258 adapt(base, t, from, to); 259 } catch (AdaptFailure ex) { 260 return null; 261 } 262 Type res = subst(sym.type, from.toList(), to.toList()); 263 if (!isSubtype(res, t)) 264 return null; 265 ListBuffer<Type> openVars = new ListBuffer<>(); 266 for (List<Type> l = sym.type.allparams(); 267 l.nonEmpty(); l = l.tail) 268 if (res.contains(l.head) && !t.contains(l.head)) 269 openVars.append(l.head); 270 if (openVars.nonEmpty()) { 271 if (t.isRaw()) { 272 // The subtype of a raw type is raw 273 res = erasure(res); 274 } else { 275 // Unbound type arguments default to ? 276 List<Type> opens = openVars.toList(); 277 ListBuffer<Type> qs = new ListBuffer<>(); 278 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) { 279 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, 280 syms.boundClass, (TypeVar) iter.head)); 281 } 282 res = subst(res, opens, qs.toList()); 283 } 284 } 285 return res; 286 } 287 288 @Override 289 public Type visitErrorType(ErrorType t, Symbol sym) { 290 return t; 291 } 292 }; 293 // </editor-fold> 294 295 // <editor-fold defaultstate="collapsed" desc="isConvertible"> 296 /** 297 * Is t a subtype of or convertible via boxing/unboxing 298 * conversion to s? 299 */ 300 public boolean isConvertible(Type t, Type s, Warner warn) { 301 if (t.hasTag(ERROR)) { 302 return true; 303 } 304 boolean tPrimitive = t.isPrimitive(); 305 boolean sPrimitive = s.isPrimitive(); 306 if (tPrimitive == sPrimitive) { 307 return isSubtypeUnchecked(t, s, warn); 308 } 309 return tPrimitive 310 ? isSubtype(boxedClass(t).type, s) 311 : isSubtype(unboxedType(t), s); 312 } 313 314 /** 315 * Is t a subtype of or convertible via boxing/unboxing 316 * conversions to s? 317 */ 318 public boolean isConvertible(Type t, Type s) { 319 return isConvertible(t, s, noWarnings); 320 } 321 // </editor-fold> 322 323 // <editor-fold defaultstate="collapsed" desc="findSam"> 324 325 /** 326 * Exception used to report a function descriptor lookup failure. The exception 327 * wraps a diagnostic that can be used to generate more details error 328 * messages. 329 */ 330 public static class FunctionDescriptorLookupError extends RuntimeException { 331 private static final long serialVersionUID = 0; 332 333 JCDiagnostic diagnostic; 334 335 FunctionDescriptorLookupError() { 336 this.diagnostic = null; 337 } 338 339 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) { 340 this.diagnostic = diag; 341 return this; 342 } 343 344 public JCDiagnostic getDiagnostic() { 345 return diagnostic; 346 } 347 } 348 349 /** 350 * A cache that keeps track of function descriptors associated with given 351 * functional interfaces. 352 */ 353 class DescriptorCache { 354 355 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>(); 356 357 class FunctionDescriptor { 358 Symbol descSym; 359 360 FunctionDescriptor(Symbol descSym) { 361 this.descSym = descSym; 362 } 363 364 public Symbol getSymbol() { 365 return descSym; 366 } 367 368 public Type getType(Type site) { 369 site = removeWildcards(site); 370 if (!chk.checkValidGenericType(site)) { 371 //if the inferred functional interface type is not well-formed, 372 //or if it's not a subtype of the original target, issue an error 373 throw failure(diags.fragment("no.suitable.functional.intf.inst", site)); 374 } 375 return memberType(site, descSym); 376 } 377 } 378 379 class Entry { 380 final FunctionDescriptor cachedDescRes; 381 final int prevMark; 382 383 public Entry(FunctionDescriptor cachedDescRes, 384 int prevMark) { 385 this.cachedDescRes = cachedDescRes; 386 this.prevMark = prevMark; 387 } 388 389 boolean matches(int mark) { 390 return this.prevMark == mark; 391 } 392 } 393 394 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError { 395 Entry e = _map.get(origin); 396 CompoundScope members = membersClosure(origin.type, false); 397 if (e == null || 398 !e.matches(members.getMark())) { 399 FunctionDescriptor descRes = findDescriptorInternal(origin, members); 400 _map.put(origin, new Entry(descRes, members.getMark())); 401 return descRes; 402 } 403 else { 404 return e.cachedDescRes; 405 } 406 } 407 408 /** 409 * Compute the function descriptor associated with a given functional interface 410 */ 411 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin, 412 CompoundScope membersCache) throws FunctionDescriptorLookupError { 413 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0) { 414 //t must be an interface 415 throw failure("not.a.functional.intf", origin); 416 } 417 418 final ListBuffer<Symbol> abstracts = new ListBuffer<>(); 419 for (Symbol sym : membersCache.getSymbols(new DescriptorFilter(origin))) { 420 Type mtype = memberType(origin.type, sym); 421 if (abstracts.isEmpty() || 422 (sym.name == abstracts.first().name && 423 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) { 424 abstracts.append(sym); 425 } else { 426 //the target method(s) should be the only abstract members of t 427 throw failure("not.a.functional.intf.1", origin, 428 diags.fragment("incompatible.abstracts", Kinds.kindName(origin), origin)); 429 } 430 } 431 if (abstracts.isEmpty()) { 432 //t must define a suitable non-generic method 433 throw failure("not.a.functional.intf.1", origin, 434 diags.fragment("no.abstracts", Kinds.kindName(origin), origin)); 435 } else if (abstracts.size() == 1) { 436 return new FunctionDescriptor(abstracts.first()); 437 } else { // size > 1 438 FunctionDescriptor descRes = mergeDescriptors(origin, abstracts.toList()); 439 if (descRes == null) { 440 //we can get here if the functional interface is ill-formed 441 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>(); 442 for (Symbol desc : abstracts) { 443 String key = desc.type.getThrownTypes().nonEmpty() ? 444 "descriptor.throws" : "descriptor"; 445 descriptors.append(diags.fragment(key, desc.name, 446 desc.type.getParameterTypes(), 447 desc.type.getReturnType(), 448 desc.type.getThrownTypes())); 449 } 450 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors = 451 new JCDiagnostic.MultilineDiagnostic(diags.fragment("incompatible.descs.in.functional.intf", 452 Kinds.kindName(origin), origin), descriptors.toList()); 453 throw failure(incompatibleDescriptors); 454 } 455 return descRes; 456 } 457 } 458 459 /** 460 * Compute a synthetic type for the target descriptor given a list 461 * of override-equivalent methods in the functional interface type. 462 * The resulting method type is a method type that is override-equivalent 463 * and return-type substitutable with each method in the original list. 464 */ 465 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) { 466 //pick argument types - simply take the signature that is a 467 //subsignature of all other signatures in the list (as per JLS 8.4.2) 468 List<Symbol> mostSpecific = List.nil(); 469 outer: for (Symbol msym1 : methodSyms) { 470 Type mt1 = memberType(origin.type, msym1); 471 for (Symbol msym2 : methodSyms) { 472 Type mt2 = memberType(origin.type, msym2); 473 if (!isSubSignature(mt1, mt2)) { 474 continue outer; 475 } 476 } 477 mostSpecific = mostSpecific.prepend(msym1); 478 } 479 if (mostSpecific.isEmpty()) { 480 return null; 481 } 482 483 484 //pick return types - this is done in two phases: (i) first, the most 485 //specific return type is chosen using strict subtyping; if this fails, 486 //a second attempt is made using return type substitutability (see JLS 8.4.5) 487 boolean phase2 = false; 488 Symbol bestSoFar = null; 489 while (bestSoFar == null) { 490 outer: for (Symbol msym1 : mostSpecific) { 491 Type mt1 = memberType(origin.type, msym1); 492 for (Symbol msym2 : methodSyms) { 493 Type mt2 = memberType(origin.type, msym2); 494 if (phase2 ? 495 !returnTypeSubstitutable(mt1, mt2) : 496 !isSubtypeInternal(mt1.getReturnType(), mt2.getReturnType())) { 497 continue outer; 498 } 499 } 500 bestSoFar = msym1; 501 } 502 if (phase2) { 503 break; 504 } else { 505 phase2 = true; 506 } 507 } 508 if (bestSoFar == null) return null; 509 510 //merge thrown types - form the intersection of all the thrown types in 511 //all the signatures in the list 512 boolean toErase = !bestSoFar.type.hasTag(FORALL); 513 List<Type> thrown = null; 514 Type mt1 = memberType(origin.type, bestSoFar); 515 for (Symbol msym2 : methodSyms) { 516 Type mt2 = memberType(origin.type, msym2); 517 List<Type> thrown_mt2 = mt2.getThrownTypes(); 518 if (toErase) { 519 thrown_mt2 = erasure(thrown_mt2); 520 } else { 521 /* If bestSoFar is generic then all the methods are generic. 522 * The opposite is not true: a non generic method can override 523 * a generic method (raw override) so it's safe to cast mt1 and 524 * mt2 to ForAll. 525 */ 526 ForAll fa1 = (ForAll)mt1; 527 ForAll fa2 = (ForAll)mt2; 528 thrown_mt2 = subst(thrown_mt2, fa2.tvars, fa1.tvars); 529 } 530 thrown = (thrown == null) ? 531 thrown_mt2 : 532 chk.intersect(thrown_mt2, thrown); 533 } 534 535 final List<Type> thrown1 = thrown; 536 return new FunctionDescriptor(bestSoFar) { 537 @Override 538 public Type getType(Type origin) { 539 Type mt = memberType(origin, getSymbol()); 540 return createMethodTypeWithThrown(mt, thrown1); 541 } 542 }; 543 } 544 545 boolean isSubtypeInternal(Type s, Type t) { 546 return (s.isPrimitive() && t.isPrimitive()) ? 547 isSameType(t, s) : 548 isSubtype(s, t); 549 } 550 551 FunctionDescriptorLookupError failure(String msg, Object... args) { 552 return failure(diags.fragment(msg, args)); 553 } 554 555 FunctionDescriptorLookupError failure(JCDiagnostic diag) { 556 return functionDescriptorLookupError.setMessage(diag); 557 } 558 } 559 560 private DescriptorCache descCache = new DescriptorCache(); 561 562 /** 563 * Find the method descriptor associated to this class symbol - if the 564 * symbol 'origin' is not a functional interface, an exception is thrown. 565 */ 566 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError { 567 return descCache.get(origin).getSymbol(); 568 } 569 570 /** 571 * Find the type of the method descriptor associated to this class symbol - 572 * if the symbol 'origin' is not a functional interface, an exception is thrown. 573 */ 574 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError { 575 return descCache.get(origin.tsym).getType(origin); 576 } 577 578 /** 579 * Is given type a functional interface? 580 */ 581 public boolean isFunctionalInterface(TypeSymbol tsym) { 582 try { 583 findDescriptorSymbol(tsym); 584 return true; 585 } catch (FunctionDescriptorLookupError ex) { 586 return false; 587 } 588 } 589 590 public boolean isFunctionalInterface(Type site) { 591 try { 592 findDescriptorType(site); 593 return true; 594 } catch (FunctionDescriptorLookupError ex) { 595 return false; 596 } 597 } 598 599 public Type removeWildcards(Type site) { 600 Type capturedSite = capture(site); 601 if (capturedSite != site) { 602 Type formalInterface = site.tsym.type; 603 ListBuffer<Type> typeargs = new ListBuffer<>(); 604 List<Type> actualTypeargs = site.getTypeArguments(); 605 List<Type> capturedTypeargs = capturedSite.getTypeArguments(); 606 //simply replace the wildcards with its bound 607 for (Type t : formalInterface.getTypeArguments()) { 608 if (actualTypeargs.head.hasTag(WILDCARD)) { 609 WildcardType wt = (WildcardType)actualTypeargs.head; 610 Type bound; 611 switch (wt.kind) { 612 case EXTENDS: 613 case UNBOUND: 614 CapturedType capVar = (CapturedType)capturedTypeargs.head; 615 //use declared bound if it doesn't depend on formal type-args 616 bound = capVar.bound.containsAny(capturedSite.getTypeArguments()) ? 617 wt.type : capVar.bound; 618 break; 619 default: 620 bound = wt.type; 621 } 622 typeargs.append(bound); 623 } else { 624 typeargs.append(actualTypeargs.head); 625 } 626 actualTypeargs = actualTypeargs.tail; 627 capturedTypeargs = capturedTypeargs.tail; 628 } 629 return subst(formalInterface, formalInterface.getTypeArguments(), typeargs.toList()); 630 } else { 631 return site; 632 } 633 } 634 635 /** 636 * Create a symbol for a class that implements a given functional interface 637 * and overrides its functional descriptor. This routine is used for two 638 * main purposes: (i) checking well-formedness of a functional interface; 639 * (ii) perform functional interface bridge calculation. 640 */ 641 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, List<Type> targets, long cflags) { 642 if (targets.isEmpty()) { 643 return null; 644 } 645 Symbol descSym = findDescriptorSymbol(targets.head.tsym); 646 Type descType = findDescriptorType(targets.head); 647 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass()); 648 csym.completer = Completer.NULL_COMPLETER; 649 csym.members_field = WriteableScope.create(csym); 650 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym); 651 csym.members_field.enter(instDescSym); 652 Type.ClassType ctype = new Type.ClassType(Type.noType, List.<Type>nil(), csym); 653 ctype.supertype_field = syms.objectType; 654 ctype.interfaces_field = targets; 655 csym.type = ctype; 656 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile; 657 return csym; 658 } 659 660 /** 661 * Find the minimal set of methods that are overridden by the functional 662 * descriptor in 'origin'. All returned methods are assumed to have different 663 * erased signatures. 664 */ 665 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) { 666 Assert.check(isFunctionalInterface(origin)); 667 Symbol descSym = findDescriptorSymbol(origin); 668 CompoundScope members = membersClosure(origin.type, false); 669 ListBuffer<Symbol> overridden = new ListBuffer<>(); 670 outer: for (Symbol m2 : members.getSymbolsByName(descSym.name, bridgeFilter)) { 671 if (m2 == descSym) continue; 672 else if (descSym.overrides(m2, origin, Types.this, false)) { 673 for (Symbol m3 : overridden) { 674 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) || 675 (m3.overrides(m2, origin, Types.this, false) && 676 (pendingBridges((ClassSymbol)origin, m3.enclClass()) || 677 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) { 678 continue outer; 679 } 680 } 681 overridden.add(m2); 682 } 683 } 684 return overridden.toList(); 685 } 686 //where 687 private Filter<Symbol> bridgeFilter = new Filter<Symbol>() { 688 public boolean accepts(Symbol t) { 689 return t.kind == MTH && 690 t.name != names.init && 691 t.name != names.clinit && 692 (t.flags() & SYNTHETIC) == 0; 693 } 694 }; 695 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) { 696 //a symbol will be completed from a classfile if (a) symbol has 697 //an associated file object with CLASS kind and (b) the symbol has 698 //not been entered 699 if (origin.classfile != null && 700 origin.classfile.getKind() == JavaFileObject.Kind.CLASS && 701 enter.getEnv(origin) == null) { 702 return false; 703 } 704 if (origin == s) { 705 return true; 706 } 707 for (Type t : interfaces(origin.type)) { 708 if (pendingBridges((ClassSymbol)t.tsym, s)) { 709 return true; 710 } 711 } 712 return false; 713 } 714 // </editor-fold> 715 716 /** 717 * Scope filter used to skip methods that should be ignored (such as methods 718 * overridden by j.l.Object) during function interface conversion interface check 719 */ 720 class DescriptorFilter implements Filter<Symbol> { 721 722 TypeSymbol origin; 723 724 DescriptorFilter(TypeSymbol origin) { 725 this.origin = origin; 726 } 727 728 @Override 729 public boolean accepts(Symbol sym) { 730 return sym.kind == MTH && 731 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT && 732 !overridesObjectMethod(origin, sym) && 733 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0; 734 } 735 } 736 737 // <editor-fold defaultstate="collapsed" desc="isSubtype"> 738 /** 739 * Is t an unchecked subtype of s? 740 */ 741 public boolean isSubtypeUnchecked(Type t, Type s) { 742 return isSubtypeUnchecked(t, s, noWarnings); 743 } 744 /** 745 * Is t an unchecked subtype of s? 746 */ 747 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) { 748 boolean result = isSubtypeUncheckedInternal(t, s, warn); 749 if (result) { 750 checkUnsafeVarargsConversion(t, s, warn); 751 } 752 return result; 753 } 754 //where 755 private boolean isSubtypeUncheckedInternal(Type t, Type s, Warner warn) { 756 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) { 757 if (((ArrayType)t).elemtype.isPrimitive()) { 758 return isSameType(elemtype(t), elemtype(s)); 759 } else { 760 return isSubtypeUnchecked(elemtype(t), elemtype(s), warn); 761 } 762 } else if (isSubtype(t, s)) { 763 return true; 764 } else if (t.hasTag(TYPEVAR)) { 765 return isSubtypeUnchecked(t.getUpperBound(), s, warn); 766 } else if (!s.isRaw()) { 767 Type t2 = asSuper(t, s.tsym); 768 if (t2 != null && t2.isRaw()) { 769 if (isReifiable(s)) { 770 warn.silentWarn(LintCategory.UNCHECKED); 771 } else { 772 warn.warn(LintCategory.UNCHECKED); 773 } 774 return true; 775 } 776 } 777 return false; 778 } 779 780 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) { 781 if (!t.hasTag(ARRAY) || isReifiable(t)) { 782 return; 783 } 784 ArrayType from = (ArrayType)t; 785 boolean shouldWarn = false; 786 switch (s.getTag()) { 787 case ARRAY: 788 ArrayType to = (ArrayType)s; 789 shouldWarn = from.isVarargs() && 790 !to.isVarargs() && 791 !isReifiable(from); 792 break; 793 case CLASS: 794 shouldWarn = from.isVarargs(); 795 break; 796 } 797 if (shouldWarn) { 798 warn.warn(LintCategory.VARARGS); 799 } 800 } 801 802 /** 803 * Is t a subtype of s?<br> 804 * (not defined for Method and ForAll types) 805 */ 806 final public boolean isSubtype(Type t, Type s) { 807 return isSubtype(t, s, true); 808 } 809 final public boolean isSubtypeNoCapture(Type t, Type s) { 810 return isSubtype(t, s, false); 811 } 812 public boolean isSubtype(Type t, Type s, boolean capture) { 813 if (t.equalsIgnoreMetadata(s)) 814 return true; 815 if (s.isPartial()) 816 return isSuperType(s, t); 817 818 if (s.isCompound()) { 819 for (Type s2 : interfaces(s).prepend(supertype(s))) { 820 if (!isSubtype(t, s2, capture)) 821 return false; 822 } 823 return true; 824 } 825 826 // Generally, if 's' is a lower-bounded type variable, recur on lower bound; but 827 // for inference variables and intersections, we need to keep 's' 828 // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars) 829 if (!t.hasTag(UNDETVAR) && !t.isCompound()) { 830 // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s 831 Type lower = cvarLowerBound(wildLowerBound(s)); 832 if (s != lower && !lower.hasTag(BOT)) 833 return isSubtype(capture ? capture(t) : t, lower, false); 834 } 835 836 return isSubtype.visit(capture ? capture(t) : t, s); 837 } 838 // where 839 private TypeRelation isSubtype = new TypeRelation() 840 { 841 @Override 842 public Boolean visitType(Type t, Type s) { 843 switch (t.getTag()) { 844 case BYTE: 845 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag())); 846 case CHAR: 847 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag())); 848 case SHORT: case INT: case LONG: 849 case FLOAT: case DOUBLE: 850 return t.getTag().isSubRangeOf(s.getTag()); 851 case BOOLEAN: case VOID: 852 return t.hasTag(s.getTag()); 853 case TYPEVAR: 854 return isSubtypeNoCapture(t.getUpperBound(), s); 855 case BOT: 856 return 857 s.hasTag(BOT) || s.hasTag(CLASS) || 858 s.hasTag(ARRAY) || s.hasTag(TYPEVAR); 859 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495) 860 case NONE: 861 return false; 862 default: 863 throw new AssertionError("isSubtype " + t.getTag()); 864 } 865 } 866 867 private Set<TypePair> cache = new HashSet<>(); 868 869 private boolean containsTypeRecursive(Type t, Type s) { 870 TypePair pair = new TypePair(t, s); 871 if (cache.add(pair)) { 872 try { 873 return containsType(t.getTypeArguments(), 874 s.getTypeArguments()); 875 } finally { 876 cache.remove(pair); 877 } 878 } else { 879 return containsType(t.getTypeArguments(), 880 rewriteSupers(s).getTypeArguments()); 881 } 882 } 883 884 private Type rewriteSupers(Type t) { 885 if (!t.isParameterized()) 886 return t; 887 ListBuffer<Type> from = new ListBuffer<>(); 888 ListBuffer<Type> to = new ListBuffer<>(); 889 adaptSelf(t, from, to); 890 if (from.isEmpty()) 891 return t; 892 ListBuffer<Type> rewrite = new ListBuffer<>(); 893 boolean changed = false; 894 for (Type orig : to.toList()) { 895 Type s = rewriteSupers(orig); 896 if (s.isSuperBound() && !s.isExtendsBound()) { 897 s = new WildcardType(syms.objectType, 898 BoundKind.UNBOUND, 899 syms.boundClass, 900 s.getMetadata()); 901 changed = true; 902 } else if (s != orig) { 903 s = new WildcardType(wildUpperBound(s), 904 BoundKind.EXTENDS, 905 syms.boundClass, 906 s.getMetadata()); 907 changed = true; 908 } 909 rewrite.append(s); 910 } 911 if (changed) 912 return subst(t.tsym.type, from.toList(), rewrite.toList()); 913 else 914 return t; 915 } 916 917 @Override 918 public Boolean visitClassType(ClassType t, Type s) { 919 Type sup = asSuper(t, s.tsym); 920 if (sup == null) return false; 921 // If t is an intersection, sup might not be a class type 922 if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s); 923 return sup.tsym == s.tsym 924 // Check type variable containment 925 && (!s.isParameterized() || containsTypeRecursive(s, sup)) 926 && isSubtypeNoCapture(sup.getEnclosingType(), 927 s.getEnclosingType()); 928 } 929 930 @Override 931 public Boolean visitArrayType(ArrayType t, Type s) { 932 if (s.hasTag(ARRAY)) { 933 if (t.elemtype.isPrimitive()) 934 return isSameType(t.elemtype, elemtype(s)); 935 else 936 return isSubtypeNoCapture(t.elemtype, elemtype(s)); 937 } 938 939 if (s.hasTag(CLASS)) { 940 Name sname = s.tsym.getQualifiedName(); 941 return sname == names.java_lang_Object 942 || sname == names.java_lang_Cloneable 943 || sname == names.java_io_Serializable; 944 } 945 946 return false; 947 } 948 949 @Override 950 public Boolean visitUndetVar(UndetVar t, Type s) { 951 //todo: test against origin needed? or replace with substitution? 952 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) { 953 return true; 954 } else if (s.hasTag(BOT)) { 955 //if 's' is 'null' there's no instantiated type U for which 956 //U <: s (but 'null' itself, which is not a valid type) 957 return false; 958 } 959 960 t.addBound(InferenceBound.UPPER, s, Types.this); 961 return true; 962 } 963 964 @Override 965 public Boolean visitErrorType(ErrorType t, Type s) { 966 return true; 967 } 968 }; 969 970 /** 971 * Is t a subtype of every type in given list `ts'?<br> 972 * (not defined for Method and ForAll types)<br> 973 * Allows unchecked conversions. 974 */ 975 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) { 976 for (List<Type> l = ts; l.nonEmpty(); l = l.tail) 977 if (!isSubtypeUnchecked(t, l.head, warn)) 978 return false; 979 return true; 980 } 981 982 /** 983 * Are corresponding elements of ts subtypes of ss? If lists are 984 * of different length, return false. 985 */ 986 public boolean isSubtypes(List<Type> ts, List<Type> ss) { 987 while (ts.tail != null && ss.tail != null 988 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 989 isSubtype(ts.head, ss.head)) { 990 ts = ts.tail; 991 ss = ss.tail; 992 } 993 return ts.tail == null && ss.tail == null; 994 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 995 } 996 997 /** 998 * Are corresponding elements of ts subtypes of ss, allowing 999 * unchecked conversions? If lists are of different length, 1000 * return false. 1001 **/ 1002 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) { 1003 while (ts.tail != null && ss.tail != null 1004 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1005 isSubtypeUnchecked(ts.head, ss.head, warn)) { 1006 ts = ts.tail; 1007 ss = ss.tail; 1008 } 1009 return ts.tail == null && ss.tail == null; 1010 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1011 } 1012 // </editor-fold> 1013 1014 // <editor-fold defaultstate="collapsed" desc="isSuperType"> 1015 /** 1016 * Is t a supertype of s? 1017 */ 1018 public boolean isSuperType(Type t, Type s) { 1019 switch (t.getTag()) { 1020 case ERROR: 1021 return true; 1022 case UNDETVAR: { 1023 UndetVar undet = (UndetVar)t; 1024 if (t == s || 1025 undet.qtype == s || 1026 s.hasTag(ERROR) || 1027 s.hasTag(BOT)) { 1028 return true; 1029 } 1030 undet.addBound(InferenceBound.LOWER, s, this); 1031 return true; 1032 } 1033 default: 1034 return isSubtype(s, t); 1035 } 1036 } 1037 // </editor-fold> 1038 1039 // <editor-fold defaultstate="collapsed" desc="isSameType"> 1040 /** 1041 * Are corresponding elements of the lists the same type? If 1042 * lists are of different length, return false. 1043 */ 1044 public boolean isSameTypes(List<Type> ts, List<Type> ss) { 1045 return isSameTypes(ts, ss, false); 1046 } 1047 public boolean isSameTypes(List<Type> ts, List<Type> ss, boolean strict) { 1048 while (ts.tail != null && ss.tail != null 1049 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1050 isSameType(ts.head, ss.head, strict)) { 1051 ts = ts.tail; 1052 ss = ss.tail; 1053 } 1054 return ts.tail == null && ss.tail == null; 1055 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1056 } 1057 1058 /** 1059 * A polymorphic signature method (JLS 15.12.3) is a method that 1060 * (i) is declared in the java.lang.invoke.MethodHandle class, (ii) takes 1061 * a single variable arity parameter (iii) whose declared type is Object[], 1062 * (iv) has a return type of Object and (v) is native. 1063 */ 1064 public boolean isSignaturePolymorphic(MethodSymbol msym) { 1065 List<Type> argtypes = msym.type.getParameterTypes(); 1066 return (msym.flags_field & NATIVE) != 0 && 1067 msym.owner == syms.methodHandleType.tsym && 1068 argtypes.tail.tail == null && 1069 argtypes.head.hasTag(TypeTag.ARRAY) && 1070 msym.type.getReturnType().tsym == syms.objectType.tsym && 1071 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym; 1072 } 1073 1074 /** 1075 * Is t the same type as s? 1076 */ 1077 public boolean isSameType(Type t, Type s) { 1078 return isSameType(t, s, false); 1079 } 1080 public boolean isSameType(Type t, Type s, boolean strict) { 1081 return strict ? 1082 isSameTypeStrict.visit(t, s) : 1083 isSameTypeLoose.visit(t, s); 1084 } 1085 // where 1086 abstract class SameTypeVisitor extends TypeRelation { 1087 1088 public Boolean visitType(Type t, Type s) { 1089 if (t.equalsIgnoreMetadata(s)) 1090 return true; 1091 1092 if (s.isPartial()) 1093 return visit(s, t); 1094 1095 switch (t.getTag()) { 1096 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: 1097 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE: 1098 return t.hasTag(s.getTag()); 1099 case TYPEVAR: { 1100 if (s.hasTag(TYPEVAR)) { 1101 //type-substitution does not preserve type-var types 1102 //check that type var symbols and bounds are indeed the same 1103 return sameTypeVars((TypeVar)t, (TypeVar)s); 1104 } 1105 else { 1106 //special case for s == ? super X, where upper(s) = u 1107 //check that u == t, where u has been set by Type.withTypeVar 1108 return s.isSuperBound() && 1109 !s.isExtendsBound() && 1110 visit(t, wildUpperBound(s)); 1111 } 1112 } 1113 default: 1114 throw new AssertionError("isSameType " + t.getTag()); 1115 } 1116 } 1117 1118 abstract boolean sameTypeVars(TypeVar tv1, TypeVar tv2); 1119 1120 @Override 1121 public Boolean visitWildcardType(WildcardType t, Type s) { 1122 if (s.isPartial()) 1123 return visit(s, t); 1124 else 1125 return false; 1126 } 1127 1128 @Override 1129 public Boolean visitClassType(ClassType t, Type s) { 1130 if (t == s) 1131 return true; 1132 1133 if (s.isPartial()) 1134 return visit(s, t); 1135 1136 if (s.isSuperBound() && !s.isExtendsBound()) 1137 return visit(t, wildUpperBound(s)) && visit(t, wildLowerBound(s)); 1138 1139 if (t.isCompound() && s.isCompound()) { 1140 if (!visit(supertype(t), supertype(s))) 1141 return false; 1142 1143 HashSet<UniqueType> set = new HashSet<>(); 1144 for (Type x : interfaces(t)) 1145 set.add(new UniqueType(x, Types.this)); 1146 for (Type x : interfaces(s)) { 1147 if (!set.remove(new UniqueType(x, Types.this))) 1148 return false; 1149 } 1150 return (set.isEmpty()); 1151 } 1152 return t.tsym == s.tsym 1153 && visit(t.getEnclosingType(), s.getEnclosingType()) 1154 && containsTypes(t.getTypeArguments(), s.getTypeArguments()); 1155 } 1156 1157 abstract protected boolean containsTypes(List<Type> ts1, List<Type> ts2); 1158 1159 @Override 1160 public Boolean visitArrayType(ArrayType t, Type s) { 1161 if (t == s) 1162 return true; 1163 1164 if (s.isPartial()) 1165 return visit(s, t); 1166 1167 return s.hasTag(ARRAY) 1168 && containsTypeEquivalent(t.elemtype, elemtype(s)); 1169 } 1170 1171 @Override 1172 public Boolean visitMethodType(MethodType t, Type s) { 1173 // isSameType for methods does not take thrown 1174 // exceptions into account! 1175 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType()); 1176 } 1177 1178 @Override 1179 public Boolean visitPackageType(PackageType t, Type s) { 1180 return t == s; 1181 } 1182 1183 @Override 1184 public Boolean visitForAll(ForAll t, Type s) { 1185 if (!s.hasTag(FORALL)) { 1186 return false; 1187 } 1188 1189 ForAll forAll = (ForAll)s; 1190 return hasSameBounds(t, forAll) 1191 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); 1192 } 1193 1194 @Override 1195 public Boolean visitUndetVar(UndetVar t, Type s) { 1196 if (s.hasTag(WILDCARD)) { 1197 // FIXME, this might be leftovers from before capture conversion 1198 return false; 1199 } 1200 1201 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) { 1202 return true; 1203 } 1204 1205 t.addBound(InferenceBound.EQ, s, Types.this); 1206 1207 return true; 1208 } 1209 1210 @Override 1211 public Boolean visitErrorType(ErrorType t, Type s) { 1212 return true; 1213 } 1214 } 1215 1216 /** 1217 * Standard type-equality relation - type variables are considered 1218 * equals if they share the same type symbol. 1219 */ 1220 TypeRelation isSameTypeLoose = new LooseSameTypeVisitor(); 1221 1222 private class LooseSameTypeVisitor extends SameTypeVisitor { 1223 1224 /** cache of the type-variable pairs being (recursively) tested. */ 1225 private Set<TypePair> cache = new HashSet<>(); 1226 1227 @Override 1228 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) { 1229 return tv1.tsym == tv2.tsym && checkSameBounds(tv1, tv2); 1230 } 1231 @Override 1232 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) { 1233 return containsTypeEquivalent(ts1, ts2); 1234 } 1235 1236 /** 1237 * Since type-variable bounds can be recursive, we need to protect against 1238 * infinite loops - where the same bounds are checked over and over recursively. 1239 */ 1240 private boolean checkSameBounds(TypeVar tv1, TypeVar tv2) { 1241 TypePair p = new TypePair(tv1, tv2, true); 1242 if (cache.add(p)) { 1243 try { 1244 return visit(tv1.getUpperBound(), tv2.getUpperBound()); 1245 } finally { 1246 cache.remove(p); 1247 } 1248 } else { 1249 return false; 1250 } 1251 } 1252 }; 1253 1254 /** 1255 * Strict type-equality relation - type variables are considered 1256 * equals if they share the same object identity. 1257 */ 1258 TypeRelation isSameTypeStrict = new SameTypeVisitor() { 1259 @Override 1260 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) { 1261 return tv1 == tv2; 1262 } 1263 @Override 1264 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) { 1265 return isSameTypes(ts1, ts2, true); 1266 } 1267 1268 @Override 1269 public Boolean visitWildcardType(WildcardType t, Type s) { 1270 if (!s.hasTag(WILDCARD)) { 1271 return false; 1272 } else { 1273 WildcardType t2 = (WildcardType)s; 1274 return t.kind == t2.kind && 1275 isSameType(t.type, t2.type, true); 1276 } 1277 } 1278 }; 1279 1280 // </editor-fold> 1281 1282 // <editor-fold defaultstate="collapsed" desc="Contains Type"> 1283 public boolean containedBy(Type t, Type s) { 1284 switch (t.getTag()) { 1285 case UNDETVAR: 1286 if (s.hasTag(WILDCARD)) { 1287 UndetVar undetvar = (UndetVar)t; 1288 WildcardType wt = (WildcardType)s; 1289 switch(wt.kind) { 1290 case UNBOUND: 1291 break; 1292 case EXTENDS: { 1293 Type bound = wildUpperBound(s); 1294 undetvar.addBound(InferenceBound.UPPER, bound, this); 1295 break; 1296 } 1297 case SUPER: { 1298 Type bound = wildLowerBound(s); 1299 undetvar.addBound(InferenceBound.LOWER, bound, this); 1300 break; 1301 } 1302 } 1303 return true; 1304 } else { 1305 return isSameType(t, s); 1306 } 1307 case ERROR: 1308 return true; 1309 default: 1310 return containsType(s, t); 1311 } 1312 } 1313 1314 boolean containsType(List<Type> ts, List<Type> ss) { 1315 while (ts.nonEmpty() && ss.nonEmpty() 1316 && containsType(ts.head, ss.head)) { 1317 ts = ts.tail; 1318 ss = ss.tail; 1319 } 1320 return ts.isEmpty() && ss.isEmpty(); 1321 } 1322 1323 /** 1324 * Check if t contains s. 1325 * 1326 * <p>T contains S if: 1327 * 1328 * <p>{@code L(T) <: L(S) && U(S) <: U(T)} 1329 * 1330 * <p>This relation is only used by ClassType.isSubtype(), that 1331 * is, 1332 * 1333 * <p>{@code C<S> <: C<T> if T contains S.} 1334 * 1335 * <p>Because of F-bounds, this relation can lead to infinite 1336 * recursion. Thus we must somehow break that recursion. Notice 1337 * that containsType() is only called from ClassType.isSubtype(). 1338 * Since the arguments have already been checked against their 1339 * bounds, we know: 1340 * 1341 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)} 1342 * 1343 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)} 1344 * 1345 * @param t a type 1346 * @param s a type 1347 */ 1348 public boolean containsType(Type t, Type s) { 1349 return containsType.visit(t, s); 1350 } 1351 // where 1352 private TypeRelation containsType = new TypeRelation() { 1353 1354 public Boolean visitType(Type t, Type s) { 1355 if (s.isPartial()) 1356 return containedBy(s, t); 1357 else 1358 return isSameType(t, s); 1359 } 1360 1361// void debugContainsType(WildcardType t, Type s) { 1362// System.err.println(); 1363// System.err.format(" does %s contain %s?%n", t, s); 1364// System.err.format(" %s U(%s) <: U(%s) %s = %s%n", 1365// wildUpperBound(s), s, t, wildUpperBound(t), 1366// t.isSuperBound() 1367// || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t))); 1368// System.err.format(" %s L(%s) <: L(%s) %s = %s%n", 1369// wildLowerBound(t), t, s, wildLowerBound(s), 1370// t.isExtendsBound() 1371// || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))); 1372// System.err.println(); 1373// } 1374 1375 @Override 1376 public Boolean visitWildcardType(WildcardType t, Type s) { 1377 if (s.isPartial()) 1378 return containedBy(s, t); 1379 else { 1380// debugContainsType(t, s); 1381 return isSameWildcard(t, s) 1382 || isCaptureOf(s, t) 1383 || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) && 1384 (t.isSuperBound() || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t)))); 1385 } 1386 } 1387 1388 @Override 1389 public Boolean visitUndetVar(UndetVar t, Type s) { 1390 if (!s.hasTag(WILDCARD)) { 1391 return isSameType(t, s); 1392 } else { 1393 return false; 1394 } 1395 } 1396 1397 @Override 1398 public Boolean visitErrorType(ErrorType t, Type s) { 1399 return true; 1400 } 1401 }; 1402 1403 public boolean isCaptureOf(Type s, WildcardType t) { 1404 if (!s.hasTag(TYPEVAR) || !((TypeVar)s).isCaptured()) 1405 return false; 1406 return isSameWildcard(t, ((CapturedType)s).wildcard); 1407 } 1408 1409 public boolean isSameWildcard(WildcardType t, Type s) { 1410 if (!s.hasTag(WILDCARD)) 1411 return false; 1412 WildcardType w = (WildcardType)s; 1413 return w.kind == t.kind && w.type == t.type; 1414 } 1415 1416 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) { 1417 while (ts.nonEmpty() && ss.nonEmpty() 1418 && containsTypeEquivalent(ts.head, ss.head)) { 1419 ts = ts.tail; 1420 ss = ss.tail; 1421 } 1422 return ts.isEmpty() && ss.isEmpty(); 1423 } 1424 // </editor-fold> 1425 1426 // <editor-fold defaultstate="collapsed" desc="isCastable"> 1427 public boolean isCastable(Type t, Type s) { 1428 return isCastable(t, s, noWarnings); 1429 } 1430 1431 /** 1432 * Is t is castable to s?<br> 1433 * s is assumed to be an erased type.<br> 1434 * (not defined for Method and ForAll types). 1435 */ 1436 public boolean isCastable(Type t, Type s, Warner warn) { 1437 if (t == s) 1438 return true; 1439 1440 if (t.isPrimitive() != s.isPrimitive()) 1441 return (isConvertible(t, s, warn) 1442 || (allowObjectToPrimitiveCast && 1443 s.isPrimitive() && 1444 isSubtype(boxedClass(s).type, t))); 1445 if (warn != warnStack.head) { 1446 try { 1447 warnStack = warnStack.prepend(warn); 1448 checkUnsafeVarargsConversion(t, s, warn); 1449 return isCastable.visit(t,s); 1450 } finally { 1451 warnStack = warnStack.tail; 1452 } 1453 } else { 1454 return isCastable.visit(t,s); 1455 } 1456 } 1457 // where 1458 private TypeRelation isCastable = new TypeRelation() { 1459 1460 public Boolean visitType(Type t, Type s) { 1461 if (s.hasTag(ERROR)) 1462 return true; 1463 1464 switch (t.getTag()) { 1465 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: 1466 case DOUBLE: 1467 return s.isNumeric(); 1468 case BOOLEAN: 1469 return s.hasTag(BOOLEAN); 1470 case VOID: 1471 return false; 1472 case BOT: 1473 return isSubtype(t, s); 1474 default: 1475 throw new AssertionError(); 1476 } 1477 } 1478 1479 @Override 1480 public Boolean visitWildcardType(WildcardType t, Type s) { 1481 return isCastable(wildUpperBound(t), s, warnStack.head); 1482 } 1483 1484 @Override 1485 public Boolean visitClassType(ClassType t, Type s) { 1486 if (s.hasTag(ERROR) || s.hasTag(BOT)) 1487 return true; 1488 1489 if (s.hasTag(TYPEVAR)) { 1490 if (isCastable(t, s.getUpperBound(), noWarnings)) { 1491 warnStack.head.warn(LintCategory.UNCHECKED); 1492 return true; 1493 } else { 1494 return false; 1495 } 1496 } 1497 1498 if (t.isCompound() || s.isCompound()) { 1499 return !t.isCompound() ? 1500 visitCompoundType((ClassType)s, t, true) : 1501 visitCompoundType(t, s, false); 1502 } 1503 1504 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) { 1505 boolean upcast; 1506 if ((upcast = isSubtype(erasure(t), erasure(s))) 1507 || isSubtype(erasure(s), erasure(t))) { 1508 if (!upcast && s.hasTag(ARRAY)) { 1509 if (!isReifiable(s)) 1510 warnStack.head.warn(LintCategory.UNCHECKED); 1511 return true; 1512 } else if (s.isRaw()) { 1513 return true; 1514 } else if (t.isRaw()) { 1515 if (!isUnbounded(s)) 1516 warnStack.head.warn(LintCategory.UNCHECKED); 1517 return true; 1518 } 1519 // Assume |a| <: |b| 1520 final Type a = upcast ? t : s; 1521 final Type b = upcast ? s : t; 1522 final boolean HIGH = true; 1523 final boolean LOW = false; 1524 final boolean DONT_REWRITE_TYPEVARS = false; 1525 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS); 1526 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS); 1527 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS); 1528 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS); 1529 Type lowSub = asSub(bLow, aLow.tsym); 1530 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); 1531 if (highSub == null) { 1532 final boolean REWRITE_TYPEVARS = true; 1533 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS); 1534 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS); 1535 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS); 1536 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS); 1537 lowSub = asSub(bLow, aLow.tsym); 1538 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); 1539 } 1540 if (highSub != null) { 1541 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) { 1542 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym); 1543 } 1544 if (!disjointTypes(aHigh.allparams(), highSub.allparams()) 1545 && !disjointTypes(aHigh.allparams(), lowSub.allparams()) 1546 && !disjointTypes(aLow.allparams(), highSub.allparams()) 1547 && !disjointTypes(aLow.allparams(), lowSub.allparams())) { 1548 if (upcast ? giveWarning(a, b) : 1549 giveWarning(b, a)) 1550 warnStack.head.warn(LintCategory.UNCHECKED); 1551 return true; 1552 } 1553 } 1554 if (isReifiable(s)) 1555 return isSubtypeUnchecked(a, b); 1556 else 1557 return isSubtypeUnchecked(a, b, warnStack.head); 1558 } 1559 1560 // Sidecast 1561 if (s.hasTag(CLASS)) { 1562 if ((s.tsym.flags() & INTERFACE) != 0) { 1563 return ((t.tsym.flags() & FINAL) == 0) 1564 ? sideCast(t, s, warnStack.head) 1565 : sideCastFinal(t, s, warnStack.head); 1566 } else if ((t.tsym.flags() & INTERFACE) != 0) { 1567 return ((s.tsym.flags() & FINAL) == 0) 1568 ? sideCast(t, s, warnStack.head) 1569 : sideCastFinal(t, s, warnStack.head); 1570 } else { 1571 // unrelated class types 1572 return false; 1573 } 1574 } 1575 } 1576 return false; 1577 } 1578 1579 boolean visitCompoundType(ClassType ct, Type s, boolean reverse) { 1580 Warner warn = noWarnings; 1581 for (Type c : directSupertypes(ct)) { 1582 warn.clear(); 1583 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn)) 1584 return false; 1585 } 1586 if (warn.hasLint(LintCategory.UNCHECKED)) 1587 warnStack.head.warn(LintCategory.UNCHECKED); 1588 return true; 1589 } 1590 1591 @Override 1592 public Boolean visitArrayType(ArrayType t, Type s) { 1593 switch (s.getTag()) { 1594 case ERROR: 1595 case BOT: 1596 return true; 1597 case TYPEVAR: 1598 if (isCastable(s, t, noWarnings)) { 1599 warnStack.head.warn(LintCategory.UNCHECKED); 1600 return true; 1601 } else { 1602 return false; 1603 } 1604 case CLASS: 1605 return isSubtype(t, s); 1606 case ARRAY: 1607 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) { 1608 return elemtype(t).hasTag(elemtype(s).getTag()); 1609 } else { 1610 return visit(elemtype(t), elemtype(s)); 1611 } 1612 default: 1613 return false; 1614 } 1615 } 1616 1617 @Override 1618 public Boolean visitTypeVar(TypeVar t, Type s) { 1619 switch (s.getTag()) { 1620 case ERROR: 1621 case BOT: 1622 return true; 1623 case TYPEVAR: 1624 if (isSubtype(t, s)) { 1625 return true; 1626 } else if (isCastable(t.bound, s, noWarnings)) { 1627 warnStack.head.warn(LintCategory.UNCHECKED); 1628 return true; 1629 } else { 1630 return false; 1631 } 1632 default: 1633 return isCastable(t.bound, s, warnStack.head); 1634 } 1635 } 1636 1637 @Override 1638 public Boolean visitErrorType(ErrorType t, Type s) { 1639 return true; 1640 } 1641 }; 1642 // </editor-fold> 1643 1644 // <editor-fold defaultstate="collapsed" desc="disjointTypes"> 1645 public boolean disjointTypes(List<Type> ts, List<Type> ss) { 1646 while (ts.tail != null && ss.tail != null) { 1647 if (disjointType(ts.head, ss.head)) return true; 1648 ts = ts.tail; 1649 ss = ss.tail; 1650 } 1651 return false; 1652 } 1653 1654 /** 1655 * Two types or wildcards are considered disjoint if it can be 1656 * proven that no type can be contained in both. It is 1657 * conservative in that it is allowed to say that two types are 1658 * not disjoint, even though they actually are. 1659 * 1660 * The type {@code C<X>} is castable to {@code C<Y>} exactly if 1661 * {@code X} and {@code Y} are not disjoint. 1662 */ 1663 public boolean disjointType(Type t, Type s) { 1664 return disjointType.visit(t, s); 1665 } 1666 // where 1667 private TypeRelation disjointType = new TypeRelation() { 1668 1669 private Set<TypePair> cache = new HashSet<>(); 1670 1671 @Override 1672 public Boolean visitType(Type t, Type s) { 1673 if (s.hasTag(WILDCARD)) 1674 return visit(s, t); 1675 else 1676 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t); 1677 } 1678 1679 private boolean isCastableRecursive(Type t, Type s) { 1680 TypePair pair = new TypePair(t, s); 1681 if (cache.add(pair)) { 1682 try { 1683 return Types.this.isCastable(t, s); 1684 } finally { 1685 cache.remove(pair); 1686 } 1687 } else { 1688 return true; 1689 } 1690 } 1691 1692 private boolean notSoftSubtypeRecursive(Type t, Type s) { 1693 TypePair pair = new TypePair(t, s); 1694 if (cache.add(pair)) { 1695 try { 1696 return Types.this.notSoftSubtype(t, s); 1697 } finally { 1698 cache.remove(pair); 1699 } 1700 } else { 1701 return false; 1702 } 1703 } 1704 1705 @Override 1706 public Boolean visitWildcardType(WildcardType t, Type s) { 1707 if (t.isUnbound()) 1708 return false; 1709 1710 if (!s.hasTag(WILDCARD)) { 1711 if (t.isExtendsBound()) 1712 return notSoftSubtypeRecursive(s, t.type); 1713 else 1714 return notSoftSubtypeRecursive(t.type, s); 1715 } 1716 1717 if (s.isUnbound()) 1718 return false; 1719 1720 if (t.isExtendsBound()) { 1721 if (s.isExtendsBound()) 1722 return !isCastableRecursive(t.type, wildUpperBound(s)); 1723 else if (s.isSuperBound()) 1724 return notSoftSubtypeRecursive(wildLowerBound(s), t.type); 1725 } else if (t.isSuperBound()) { 1726 if (s.isExtendsBound()) 1727 return notSoftSubtypeRecursive(t.type, wildUpperBound(s)); 1728 } 1729 return false; 1730 } 1731 }; 1732 // </editor-fold> 1733 1734 // <editor-fold defaultstate="collapsed" desc="cvarLowerBounds"> 1735 public List<Type> cvarLowerBounds(List<Type> ts) { 1736 return ts.map(cvarLowerBoundMapping); 1737 } 1738 private final TypeMapping<Void> cvarLowerBoundMapping = new TypeMapping<Void>() { 1739 @Override 1740 public Type visitCapturedType(CapturedType t, Void _unused) { 1741 return cvarLowerBound(t); 1742 } 1743 }; 1744 // </editor-fold> 1745 1746 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype"> 1747 /** 1748 * This relation answers the question: is impossible that 1749 * something of type `t' can be a subtype of `s'? This is 1750 * different from the question "is `t' not a subtype of `s'?" 1751 * when type variables are involved: Integer is not a subtype of T 1752 * where {@code <T extends Number>} but it is not true that Integer cannot 1753 * possibly be a subtype of T. 1754 */ 1755 public boolean notSoftSubtype(Type t, Type s) { 1756 if (t == s) return false; 1757 if (t.hasTag(TYPEVAR)) { 1758 TypeVar tv = (TypeVar) t; 1759 return !isCastable(tv.bound, 1760 relaxBound(s), 1761 noWarnings); 1762 } 1763 if (!s.hasTag(WILDCARD)) 1764 s = cvarUpperBound(s); 1765 1766 return !isSubtype(t, relaxBound(s)); 1767 } 1768 1769 private Type relaxBound(Type t) { 1770 return (t.hasTag(TYPEVAR)) ? 1771 rewriteQuantifiers(skipTypeVars(t, false), true, true) : 1772 t; 1773 } 1774 // </editor-fold> 1775 1776 // <editor-fold defaultstate="collapsed" desc="isReifiable"> 1777 public boolean isReifiable(Type t) { 1778 return isReifiable.visit(t); 1779 } 1780 // where 1781 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() { 1782 1783 public Boolean visitType(Type t, Void ignored) { 1784 return true; 1785 } 1786 1787 @Override 1788 public Boolean visitClassType(ClassType t, Void ignored) { 1789 if (t.isCompound()) 1790 return false; 1791 else { 1792 if (!t.isParameterized()) 1793 return true; 1794 1795 for (Type param : t.allparams()) { 1796 if (!param.isUnbound()) 1797 return false; 1798 } 1799 return true; 1800 } 1801 } 1802 1803 @Override 1804 public Boolean visitArrayType(ArrayType t, Void ignored) { 1805 return visit(t.elemtype); 1806 } 1807 1808 @Override 1809 public Boolean visitTypeVar(TypeVar t, Void ignored) { 1810 return false; 1811 } 1812 }; 1813 // </editor-fold> 1814 1815 // <editor-fold defaultstate="collapsed" desc="Array Utils"> 1816 public boolean isArray(Type t) { 1817 while (t.hasTag(WILDCARD)) 1818 t = wildUpperBound(t); 1819 return t.hasTag(ARRAY); 1820 } 1821 1822 /** 1823 * The element type of an array. 1824 */ 1825 public Type elemtype(Type t) { 1826 switch (t.getTag()) { 1827 case WILDCARD: 1828 return elemtype(wildUpperBound(t)); 1829 case ARRAY: 1830 return ((ArrayType)t).elemtype; 1831 case FORALL: 1832 return elemtype(((ForAll)t).qtype); 1833 case ERROR: 1834 return t; 1835 default: 1836 return null; 1837 } 1838 } 1839 1840 public Type elemtypeOrType(Type t) { 1841 Type elemtype = elemtype(t); 1842 return elemtype != null ? 1843 elemtype : 1844 t; 1845 } 1846 1847 /** 1848 * Mapping to take element type of an arraytype 1849 */ 1850 private TypeMapping<Void> elemTypeFun = new TypeMapping<Void>() { 1851 @Override 1852 public Type visitArrayType(ArrayType t, Void _unused) { 1853 return t.elemtype; 1854 } 1855 1856 @Override 1857 public Type visitTypeVar(TypeVar t, Void _unused) { 1858 return visit(skipTypeVars(t, false)); 1859 } 1860 }; 1861 1862 /** 1863 * The number of dimensions of an array type. 1864 */ 1865 public int dimensions(Type t) { 1866 int result = 0; 1867 while (t.hasTag(ARRAY)) { 1868 result++; 1869 t = elemtype(t); 1870 } 1871 return result; 1872 } 1873 1874 /** 1875 * Returns an ArrayType with the component type t 1876 * 1877 * @param t The component type of the ArrayType 1878 * @return the ArrayType for the given component 1879 */ 1880 public ArrayType makeArrayType(Type t) { 1881 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) { 1882 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString()); 1883 } 1884 return new ArrayType(t, syms.arrayClass); 1885 } 1886 // </editor-fold> 1887 1888 // <editor-fold defaultstate="collapsed" desc="asSuper"> 1889 /** 1890 * Return the (most specific) base type of t that starts with the 1891 * given symbol. If none exists, return null. 1892 * 1893 * Caveat Emptor: Since javac represents the class of all arrays with a singleton 1894 * symbol Symtab.arrayClass, which by being a singleton cannot hold any discriminant, 1895 * this method could yield surprising answers when invoked on arrays. For example when 1896 * invoked with t being byte [] and sym being t.sym itself, asSuper would answer null. 1897 * 1898 * @param t a type 1899 * @param sym a symbol 1900 */ 1901 public Type asSuper(Type t, Symbol sym) { 1902 /* Some examples: 1903 * 1904 * (Enum<E>, Comparable) => Comparable<E> 1905 * (c.s.s.d.AttributeTree.ValueKind, Enum) => Enum<c.s.s.d.AttributeTree.ValueKind> 1906 * (c.s.s.t.ExpressionTree, c.s.s.t.Tree) => c.s.s.t.Tree 1907 * (j.u.List<capture#160 of ? extends c.s.s.d.DocTree>, Iterable) => 1908 * Iterable<capture#160 of ? extends c.s.s.d.DocTree> 1909 */ 1910 if (sym.type == syms.objectType) { //optimization 1911 return syms.objectType; 1912 } 1913 return asSuper.visit(t, sym); 1914 } 1915 // where 1916 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() { 1917 1918 public Type visitType(Type t, Symbol sym) { 1919 return null; 1920 } 1921 1922 @Override 1923 public Type visitClassType(ClassType t, Symbol sym) { 1924 if (t.tsym == sym) 1925 return t; 1926 1927 Type st = supertype(t); 1928 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) { 1929 Type x = asSuper(st, sym); 1930 if (x != null) 1931 return x; 1932 } 1933 if ((sym.flags() & INTERFACE) != 0) { 1934 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { 1935 if (!l.head.hasTag(ERROR)) { 1936 Type x = asSuper(l.head, sym); 1937 if (x != null) 1938 return x; 1939 } 1940 } 1941 } 1942 return null; 1943 } 1944 1945 @Override 1946 public Type visitArrayType(ArrayType t, Symbol sym) { 1947 return isSubtype(t, sym.type) ? sym.type : null; 1948 } 1949 1950 @Override 1951 public Type visitTypeVar(TypeVar t, Symbol sym) { 1952 if (t.tsym == sym) 1953 return t; 1954 else 1955 return asSuper(t.bound, sym); 1956 } 1957 1958 @Override 1959 public Type visitErrorType(ErrorType t, Symbol sym) { 1960 return t; 1961 } 1962 }; 1963 1964 /** 1965 * Return the base type of t or any of its outer types that starts 1966 * with the given symbol. If none exists, return null. 1967 * 1968 * @param t a type 1969 * @param sym a symbol 1970 */ 1971 public Type asOuterSuper(Type t, Symbol sym) { 1972 switch (t.getTag()) { 1973 case CLASS: 1974 do { 1975 Type s = asSuper(t, sym); 1976 if (s != null) return s; 1977 t = t.getEnclosingType(); 1978 } while (t.hasTag(CLASS)); 1979 return null; 1980 case ARRAY: 1981 return isSubtype(t, sym.type) ? sym.type : null; 1982 case TYPEVAR: 1983 return asSuper(t, sym); 1984 case ERROR: 1985 return t; 1986 default: 1987 return null; 1988 } 1989 } 1990 1991 /** 1992 * Return the base type of t or any of its enclosing types that 1993 * starts with the given symbol. If none exists, return null. 1994 * 1995 * @param t a type 1996 * @param sym a symbol 1997 */ 1998 public Type asEnclosingSuper(Type t, Symbol sym) { 1999 switch (t.getTag()) { 2000 case CLASS: 2001 do { 2002 Type s = asSuper(t, sym); 2003 if (s != null) return s; 2004 Type outer = t.getEnclosingType(); 2005 t = (outer.hasTag(CLASS)) ? outer : 2006 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type : 2007 Type.noType; 2008 } while (t.hasTag(CLASS)); 2009 return null; 2010 case ARRAY: 2011 return isSubtype(t, sym.type) ? sym.type : null; 2012 case TYPEVAR: 2013 return asSuper(t, sym); 2014 case ERROR: 2015 return t; 2016 default: 2017 return null; 2018 } 2019 } 2020 // </editor-fold> 2021 2022 // <editor-fold defaultstate="collapsed" desc="memberType"> 2023 /** 2024 * The type of given symbol, seen as a member of t. 2025 * 2026 * @param t a type 2027 * @param sym a symbol 2028 */ 2029 public Type memberType(Type t, Symbol sym) { 2030 return (sym.flags() & STATIC) != 0 2031 ? sym.type 2032 : memberType.visit(t, sym); 2033 } 2034 // where 2035 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() { 2036 2037 public Type visitType(Type t, Symbol sym) { 2038 return sym.type; 2039 } 2040 2041 @Override 2042 public Type visitWildcardType(WildcardType t, Symbol sym) { 2043 return memberType(wildUpperBound(t), sym); 2044 } 2045 2046 @Override 2047 public Type visitClassType(ClassType t, Symbol sym) { 2048 Symbol owner = sym.owner; 2049 long flags = sym.flags(); 2050 if (((flags & STATIC) == 0) && owner.type.isParameterized()) { 2051 Type base = asOuterSuper(t, owner); 2052 //if t is an intersection type T = CT & I1 & I2 ... & In 2053 //its supertypes CT, I1, ... In might contain wildcards 2054 //so we need to go through capture conversion 2055 base = t.isCompound() ? capture(base) : base; 2056 if (base != null) { 2057 List<Type> ownerParams = owner.type.allparams(); 2058 List<Type> baseParams = base.allparams(); 2059 if (ownerParams.nonEmpty()) { 2060 if (baseParams.isEmpty()) { 2061 // then base is a raw type 2062 return erasure(sym.type); 2063 } else { 2064 return subst(sym.type, ownerParams, baseParams); 2065 } 2066 } 2067 } 2068 } 2069 return sym.type; 2070 } 2071 2072 @Override 2073 public Type visitTypeVar(TypeVar t, Symbol sym) { 2074 return memberType(t.bound, sym); 2075 } 2076 2077 @Override 2078 public Type visitErrorType(ErrorType t, Symbol sym) { 2079 return t; 2080 } 2081 }; 2082 // </editor-fold> 2083 2084 // <editor-fold defaultstate="collapsed" desc="isAssignable"> 2085 public boolean isAssignable(Type t, Type s) { 2086 return isAssignable(t, s, noWarnings); 2087 } 2088 2089 /** 2090 * Is t assignable to s?<br> 2091 * Equivalent to subtype except for constant values and raw 2092 * types.<br> 2093 * (not defined for Method and ForAll types) 2094 */ 2095 public boolean isAssignable(Type t, Type s, Warner warn) { 2096 if (t.hasTag(ERROR)) 2097 return true; 2098 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) { 2099 int value = ((Number)t.constValue()).intValue(); 2100 switch (s.getTag()) { 2101 case BYTE: 2102 if (Byte.MIN_VALUE <= value && value <= Byte.MAX_VALUE) 2103 return true; 2104 break; 2105 case CHAR: 2106 if (Character.MIN_VALUE <= value && value <= Character.MAX_VALUE) 2107 return true; 2108 break; 2109 case SHORT: 2110 if (Short.MIN_VALUE <= value && value <= Short.MAX_VALUE) 2111 return true; 2112 break; 2113 case INT: 2114 return true; 2115 case CLASS: 2116 switch (unboxedType(s).getTag()) { 2117 case BYTE: 2118 case CHAR: 2119 case SHORT: 2120 return isAssignable(t, unboxedType(s), warn); 2121 } 2122 break; 2123 } 2124 } 2125 return isConvertible(t, s, warn); 2126 } 2127 // </editor-fold> 2128 2129 // <editor-fold defaultstate="collapsed" desc="erasure"> 2130 /** 2131 * The erasure of t {@code |t|} -- the type that results when all 2132 * type parameters in t are deleted. 2133 */ 2134 public Type erasure(Type t) { 2135 return eraseNotNeeded(t) ? t : erasure(t, false); 2136 } 2137 //where 2138 private boolean eraseNotNeeded(Type t) { 2139 // We don't want to erase primitive types and String type as that 2140 // operation is idempotent. Also, erasing these could result in loss 2141 // of information such as constant values attached to such types. 2142 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym); 2143 } 2144 2145 private Type erasure(Type t, boolean recurse) { 2146 if (t.isPrimitive()) { 2147 return t; /* fast special case */ 2148 } else { 2149 Type out = erasure.visit(t, recurse); 2150 return out; 2151 } 2152 } 2153 // where 2154 private TypeMapping<Boolean> erasure = new TypeMapping<Boolean>() { 2155 private Type combineMetadata(final Type s, 2156 final Type t) { 2157 if (t.getMetadata() != TypeMetadata.EMPTY) { 2158 switch (s.getKind()) { 2159 case OTHER: 2160 case UNION: 2161 case INTERSECTION: 2162 case PACKAGE: 2163 case EXECUTABLE: 2164 case NONE: 2165 case VOID: 2166 case ERROR: 2167 return s; 2168 default: return s.cloneWithMetadata(s.getMetadata().without(Kind.ANNOTATIONS)); 2169 } 2170 } else { 2171 return s; 2172 } 2173 } 2174 2175 public Type visitType(Type t, Boolean recurse) { 2176 if (t.isPrimitive()) 2177 return t; /*fast special case*/ 2178 else { 2179 //other cases already handled 2180 return combineMetadata(t, t); 2181 } 2182 } 2183 2184 @Override 2185 public Type visitWildcardType(WildcardType t, Boolean recurse) { 2186 Type erased = erasure(wildUpperBound(t), recurse); 2187 return combineMetadata(erased, t); 2188 } 2189 2190 @Override 2191 public Type visitClassType(ClassType t, Boolean recurse) { 2192 Type erased = t.tsym.erasure(Types.this); 2193 if (recurse) { 2194 erased = new ErasedClassType(erased.getEnclosingType(),erased.tsym, 2195 t.getMetadata().without(Kind.ANNOTATIONS)); 2196 return erased; 2197 } else { 2198 return combineMetadata(erased, t); 2199 } 2200 } 2201 2202 @Override 2203 public Type visitTypeVar(TypeVar t, Boolean recurse) { 2204 Type erased = erasure(t.bound, recurse); 2205 return combineMetadata(erased, t); 2206 } 2207 }; 2208 2209 public List<Type> erasure(List<Type> ts) { 2210 return erasure.visit(ts, false); 2211 } 2212 2213 public Type erasureRecursive(Type t) { 2214 return erasure(t, true); 2215 } 2216 2217 public List<Type> erasureRecursive(List<Type> ts) { 2218 return erasure.visit(ts, true); 2219 } 2220 // </editor-fold> 2221 2222 // <editor-fold defaultstate="collapsed" desc="makeIntersectionType"> 2223 /** 2224 * Make an intersection type from non-empty list of types. The list should be ordered according to 2225 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. Note that this might cause a symbol completion. 2226 * Hence, this version of makeIntersectionType may not be called during a classfile read. 2227 * 2228 * @param bounds the types from which the intersection type is formed 2229 */ 2230 public IntersectionClassType makeIntersectionType(List<Type> bounds) { 2231 return makeIntersectionType(bounds, bounds.head.tsym.isInterface()); 2232 } 2233 2234 /** 2235 * Make an intersection type from non-empty list of types. The list should be ordered according to 2236 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. This does not cause symbol completion as 2237 * an extra parameter indicates as to whether all bounds are interfaces - in which case the 2238 * supertype is implicitly assumed to be 'Object'. 2239 * 2240 * @param bounds the types from which the intersection type is formed 2241 * @param allInterfaces are all bounds interface types? 2242 */ 2243 public IntersectionClassType makeIntersectionType(List<Type> bounds, boolean allInterfaces) { 2244 Assert.check(bounds.nonEmpty()); 2245 Type firstExplicitBound = bounds.head; 2246 if (allInterfaces) { 2247 bounds = bounds.prepend(syms.objectType); 2248 } 2249 ClassSymbol bc = 2250 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC, 2251 Type.moreInfo 2252 ? names.fromString(bounds.toString()) 2253 : names.empty, 2254 null, 2255 syms.noSymbol); 2256 IntersectionClassType intersectionType = new IntersectionClassType(bounds, bc, allInterfaces); 2257 bc.type = intersectionType; 2258 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ? 2259 syms.objectType : // error condition, recover 2260 erasure(firstExplicitBound); 2261 bc.members_field = WriteableScope.create(bc); 2262 return intersectionType; 2263 } 2264 // </editor-fold> 2265 2266 // <editor-fold defaultstate="collapsed" desc="supertype"> 2267 public Type supertype(Type t) { 2268 return supertype.visit(t); 2269 } 2270 // where 2271 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() { 2272 2273 public Type visitType(Type t, Void ignored) { 2274 // A note on wildcards: there is no good way to 2275 // determine a supertype for a super bounded wildcard. 2276 return Type.noType; 2277 } 2278 2279 @Override 2280 public Type visitClassType(ClassType t, Void ignored) { 2281 if (t.supertype_field == null) { 2282 Type supertype = ((ClassSymbol)t.tsym).getSuperclass(); 2283 // An interface has no superclass; its supertype is Object. 2284 if (t.isInterface()) 2285 supertype = ((ClassType)t.tsym.type).supertype_field; 2286 if (t.supertype_field == null) { 2287 List<Type> actuals = classBound(t).allparams(); 2288 List<Type> formals = t.tsym.type.allparams(); 2289 if (t.hasErasedSupertypes()) { 2290 t.supertype_field = erasureRecursive(supertype); 2291 } else if (formals.nonEmpty()) { 2292 t.supertype_field = subst(supertype, formals, actuals); 2293 } 2294 else { 2295 t.supertype_field = supertype; 2296 } 2297 } 2298 } 2299 return t.supertype_field; 2300 } 2301 2302 /** 2303 * The supertype is always a class type. If the type 2304 * variable's bounds start with a class type, this is also 2305 * the supertype. Otherwise, the supertype is 2306 * java.lang.Object. 2307 */ 2308 @Override 2309 public Type visitTypeVar(TypeVar t, Void ignored) { 2310 if (t.bound.hasTag(TYPEVAR) || 2311 (!t.bound.isCompound() && !t.bound.isInterface())) { 2312 return t.bound; 2313 } else { 2314 return supertype(t.bound); 2315 } 2316 } 2317 2318 @Override 2319 public Type visitArrayType(ArrayType t, Void ignored) { 2320 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType)) 2321 return arraySuperType(); 2322 else 2323 return new ArrayType(supertype(t.elemtype), t.tsym); 2324 } 2325 2326 @Override 2327 public Type visitErrorType(ErrorType t, Void ignored) { 2328 return Type.noType; 2329 } 2330 }; 2331 // </editor-fold> 2332 2333 // <editor-fold defaultstate="collapsed" desc="interfaces"> 2334 /** 2335 * Return the interfaces implemented by this class. 2336 */ 2337 public List<Type> interfaces(Type t) { 2338 return interfaces.visit(t); 2339 } 2340 // where 2341 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() { 2342 2343 public List<Type> visitType(Type t, Void ignored) { 2344 return List.nil(); 2345 } 2346 2347 @Override 2348 public List<Type> visitClassType(ClassType t, Void ignored) { 2349 if (t.interfaces_field == null) { 2350 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces(); 2351 if (t.interfaces_field == null) { 2352 // If t.interfaces_field is null, then t must 2353 // be a parameterized type (not to be confused 2354 // with a generic type declaration). 2355 // Terminology: 2356 // Parameterized type: List<String> 2357 // Generic type declaration: class List<E> { ... } 2358 // So t corresponds to List<String> and 2359 // t.tsym.type corresponds to List<E>. 2360 // The reason t must be parameterized type is 2361 // that completion will happen as a side 2362 // effect of calling 2363 // ClassSymbol.getInterfaces. Since 2364 // t.interfaces_field is null after 2365 // completion, we can assume that t is not the 2366 // type of a class/interface declaration. 2367 Assert.check(t != t.tsym.type, t); 2368 List<Type> actuals = t.allparams(); 2369 List<Type> formals = t.tsym.type.allparams(); 2370 if (t.hasErasedSupertypes()) { 2371 t.interfaces_field = erasureRecursive(interfaces); 2372 } else if (formals.nonEmpty()) { 2373 t.interfaces_field = subst(interfaces, formals, actuals); 2374 } 2375 else { 2376 t.interfaces_field = interfaces; 2377 } 2378 } 2379 } 2380 return t.interfaces_field; 2381 } 2382 2383 @Override 2384 public List<Type> visitTypeVar(TypeVar t, Void ignored) { 2385 if (t.bound.isCompound()) 2386 return interfaces(t.bound); 2387 2388 if (t.bound.isInterface()) 2389 return List.of(t.bound); 2390 2391 return List.nil(); 2392 } 2393 }; 2394 2395 public List<Type> directSupertypes(Type t) { 2396 return directSupertypes.visit(t); 2397 } 2398 // where 2399 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() { 2400 2401 public List<Type> visitType(final Type type, final Void ignored) { 2402 if (!type.isIntersection()) { 2403 final Type sup = supertype(type); 2404 return (sup == Type.noType || sup == type || sup == null) 2405 ? interfaces(type) 2406 : interfaces(type).prepend(sup); 2407 } else { 2408 return ((IntersectionClassType)type).getExplicitComponents(); 2409 } 2410 } 2411 }; 2412 2413 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) { 2414 for (Type i2 : interfaces(origin.type)) { 2415 if (isym == i2.tsym) return true; 2416 } 2417 return false; 2418 } 2419 // </editor-fold> 2420 2421 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw"> 2422 Map<Type,Boolean> isDerivedRawCache = new HashMap<>(); 2423 2424 public boolean isDerivedRaw(Type t) { 2425 Boolean result = isDerivedRawCache.get(t); 2426 if (result == null) { 2427 result = isDerivedRawInternal(t); 2428 isDerivedRawCache.put(t, result); 2429 } 2430 return result; 2431 } 2432 2433 public boolean isDerivedRawInternal(Type t) { 2434 if (t.isErroneous()) 2435 return false; 2436 return 2437 t.isRaw() || 2438 supertype(t) != Type.noType && isDerivedRaw(supertype(t)) || 2439 isDerivedRaw(interfaces(t)); 2440 } 2441 2442 public boolean isDerivedRaw(List<Type> ts) { 2443 List<Type> l = ts; 2444 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail; 2445 return l.nonEmpty(); 2446 } 2447 // </editor-fold> 2448 2449 // <editor-fold defaultstate="collapsed" desc="setBounds"> 2450 /** 2451 * Same as {@link Types#setBounds(TypeVar, List, boolean)}, except that third parameter is computed directly, 2452 * as follows: if all all bounds are interface types, the computed supertype is Object,otherwise 2453 * the supertype is simply left null (in this case, the supertype is assumed to be the head of 2454 * the bound list passed as second argument). Note that this check might cause a symbol completion. 2455 * Hence, this version of setBounds may not be called during a classfile read. 2456 * 2457 * @param t a type variable 2458 * @param bounds the bounds, must be nonempty 2459 */ 2460 public void setBounds(TypeVar t, List<Type> bounds) { 2461 setBounds(t, bounds, bounds.head.tsym.isInterface()); 2462 } 2463 2464 /** 2465 * Set the bounds field of the given type variable to reflect a (possibly multiple) list of bounds. 2466 * This does not cause symbol completion as an extra parameter indicates as to whether all bounds 2467 * are interfaces - in which case the supertype is implicitly assumed to be 'Object'. 2468 * 2469 * @param t a type variable 2470 * @param bounds the bounds, must be nonempty 2471 * @param allInterfaces are all bounds interface types? 2472 */ 2473 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) { 2474 t.bound = bounds.tail.isEmpty() ? 2475 bounds.head : 2476 makeIntersectionType(bounds, allInterfaces); 2477 t.rank_field = -1; 2478 } 2479 // </editor-fold> 2480 2481 // <editor-fold defaultstate="collapsed" desc="getBounds"> 2482 /** 2483 * Return list of bounds of the given type variable. 2484 */ 2485 public List<Type> getBounds(TypeVar t) { 2486 if (t.bound.hasTag(NONE)) 2487 return List.nil(); 2488 else if (t.bound.isErroneous() || !t.bound.isCompound()) 2489 return List.of(t.bound); 2490 else if ((erasure(t).tsym.flags() & INTERFACE) == 0) 2491 return interfaces(t).prepend(supertype(t)); 2492 else 2493 // No superclass was given in bounds. 2494 // In this case, supertype is Object, erasure is first interface. 2495 return interfaces(t); 2496 } 2497 // </editor-fold> 2498 2499 // <editor-fold defaultstate="collapsed" desc="classBound"> 2500 /** 2501 * If the given type is a (possibly selected) type variable, 2502 * return the bounding class of this type, otherwise return the 2503 * type itself. 2504 */ 2505 public Type classBound(Type t) { 2506 return classBound.visit(t); 2507 } 2508 // where 2509 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() { 2510 2511 public Type visitType(Type t, Void ignored) { 2512 return t; 2513 } 2514 2515 @Override 2516 public Type visitClassType(ClassType t, Void ignored) { 2517 Type outer1 = classBound(t.getEnclosingType()); 2518 if (outer1 != t.getEnclosingType()) 2519 return new ClassType(outer1, t.getTypeArguments(), t.tsym, 2520 t.getMetadata()); 2521 else 2522 return t; 2523 } 2524 2525 @Override 2526 public Type visitTypeVar(TypeVar t, Void ignored) { 2527 return classBound(supertype(t)); 2528 } 2529 2530 @Override 2531 public Type visitErrorType(ErrorType t, Void ignored) { 2532 return t; 2533 } 2534 }; 2535 // </editor-fold> 2536 2537 // <editor-fold defaultstate="collapsed" desc="sub signature / override equivalence"> 2538 /** 2539 * Returns true iff the first signature is a <em>sub 2540 * signature</em> of the other. This is <b>not</b> an equivalence 2541 * relation. 2542 * 2543 * @jls section 8.4.2. 2544 * @see #overrideEquivalent(Type t, Type s) 2545 * @param t first signature (possibly raw). 2546 * @param s second signature (could be subjected to erasure). 2547 * @return true if t is a sub signature of s. 2548 */ 2549 public boolean isSubSignature(Type t, Type s) { 2550 return isSubSignature(t, s, true); 2551 } 2552 2553 public boolean isSubSignature(Type t, Type s, boolean strict) { 2554 return hasSameArgs(t, s, strict) || hasSameArgs(t, erasure(s), strict); 2555 } 2556 2557 /** 2558 * Returns true iff these signatures are related by <em>override 2559 * equivalence</em>. This is the natural extension of 2560 * isSubSignature to an equivalence relation. 2561 * 2562 * @jls section 8.4.2. 2563 * @see #isSubSignature(Type t, Type s) 2564 * @param t a signature (possible raw, could be subjected to 2565 * erasure). 2566 * @param s a signature (possible raw, could be subjected to 2567 * erasure). 2568 * @return true if either argument is a sub signature of the other. 2569 */ 2570 public boolean overrideEquivalent(Type t, Type s) { 2571 return hasSameArgs(t, s) || 2572 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s); 2573 } 2574 2575 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) { 2576 for (Symbol sym : syms.objectType.tsym.members().getSymbolsByName(msym.name)) { 2577 if (msym.overrides(sym, origin, Types.this, true)) { 2578 return true; 2579 } 2580 } 2581 return false; 2582 } 2583 2584 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site"> 2585 class ImplementationCache { 2586 2587 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map = new WeakHashMap<>(); 2588 2589 class Entry { 2590 final MethodSymbol cachedImpl; 2591 final Filter<Symbol> implFilter; 2592 final boolean checkResult; 2593 final int prevMark; 2594 2595 public Entry(MethodSymbol cachedImpl, 2596 Filter<Symbol> scopeFilter, 2597 boolean checkResult, 2598 int prevMark) { 2599 this.cachedImpl = cachedImpl; 2600 this.implFilter = scopeFilter; 2601 this.checkResult = checkResult; 2602 this.prevMark = prevMark; 2603 } 2604 2605 boolean matches(Filter<Symbol> scopeFilter, boolean checkResult, int mark) { 2606 return this.implFilter == scopeFilter && 2607 this.checkResult == checkResult && 2608 this.prevMark == mark; 2609 } 2610 } 2611 2612 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) { 2613 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms); 2614 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null; 2615 if (cache == null) { 2616 cache = new HashMap<>(); 2617 _map.put(ms, new SoftReference<>(cache)); 2618 } 2619 Entry e = cache.get(origin); 2620 CompoundScope members = membersClosure(origin.type, true); 2621 if (e == null || 2622 !e.matches(implFilter, checkResult, members.getMark())) { 2623 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter); 2624 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark())); 2625 return impl; 2626 } 2627 else { 2628 return e.cachedImpl; 2629 } 2630 } 2631 2632 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) { 2633 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) { 2634 t = skipTypeVars(t, false); 2635 TypeSymbol c = t.tsym; 2636 Symbol bestSoFar = null; 2637 for (Symbol sym : c.members().getSymbolsByName(ms.name, implFilter)) { 2638 if (sym != null && sym.overrides(ms, origin, Types.this, checkResult)) { 2639 bestSoFar = sym; 2640 if ((sym.flags() & ABSTRACT) == 0) { 2641 //if concrete impl is found, exit immediately 2642 break; 2643 } 2644 } 2645 } 2646 if (bestSoFar != null) { 2647 //return either the (only) concrete implementation or the first abstract one 2648 return (MethodSymbol)bestSoFar; 2649 } 2650 } 2651 return null; 2652 } 2653 } 2654 2655 private ImplementationCache implCache = new ImplementationCache(); 2656 2657 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) { 2658 return implCache.get(ms, origin, checkResult, implFilter); 2659 } 2660 // </editor-fold> 2661 2662 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site"> 2663 class MembersClosureCache extends SimpleVisitor<Scope.CompoundScope, Void> { 2664 2665 private Map<TypeSymbol, CompoundScope> _map = new HashMap<>(); 2666 2667 Set<TypeSymbol> seenTypes = new HashSet<>(); 2668 2669 class MembersScope extends CompoundScope { 2670 2671 CompoundScope scope; 2672 2673 public MembersScope(CompoundScope scope) { 2674 super(scope.owner); 2675 this.scope = scope; 2676 } 2677 2678 Filter<Symbol> combine(Filter<Symbol> sf) { 2679 return s -> !s.owner.isInterface() && (sf == null || sf.accepts(s)); 2680 } 2681 2682 @Override 2683 public Iterable<Symbol> getSymbols(Filter<Symbol> sf, LookupKind lookupKind) { 2684 return scope.getSymbols(combine(sf), lookupKind); 2685 } 2686 2687 @Override 2688 public Iterable<Symbol> getSymbolsByName(Name name, Filter<Symbol> sf, LookupKind lookupKind) { 2689 return scope.getSymbolsByName(name, combine(sf), lookupKind); 2690 } 2691 2692 @Override 2693 public int getMark() { 2694 return scope.getMark(); 2695 } 2696 } 2697 2698 CompoundScope nilScope; 2699 2700 /** members closure visitor methods **/ 2701 2702 public CompoundScope visitType(Type t, Void _unused) { 2703 if (nilScope == null) { 2704 nilScope = new CompoundScope(syms.noSymbol); 2705 } 2706 return nilScope; 2707 } 2708 2709 @Override 2710 public CompoundScope visitClassType(ClassType t, Void _unused) { 2711 if (!seenTypes.add(t.tsym)) { 2712 //this is possible when an interface is implemented in multiple 2713 //superclasses, or when a class hierarchy is circular - in such 2714 //cases we don't need to recurse (empty scope is returned) 2715 return new CompoundScope(t.tsym); 2716 } 2717 try { 2718 seenTypes.add(t.tsym); 2719 ClassSymbol csym = (ClassSymbol)t.tsym; 2720 CompoundScope membersClosure = _map.get(csym); 2721 if (membersClosure == null) { 2722 membersClosure = new CompoundScope(csym); 2723 for (Type i : interfaces(t)) { 2724 membersClosure.prependSubScope(visit(i, null)); 2725 } 2726 membersClosure.prependSubScope(visit(supertype(t), null)); 2727 membersClosure.prependSubScope(csym.members()); 2728 _map.put(csym, membersClosure); 2729 } 2730 return membersClosure; 2731 } 2732 finally { 2733 seenTypes.remove(t.tsym); 2734 } 2735 } 2736 2737 @Override 2738 public CompoundScope visitTypeVar(TypeVar t, Void _unused) { 2739 return visit(t.getUpperBound(), null); 2740 } 2741 } 2742 2743 private MembersClosureCache membersCache = new MembersClosureCache(); 2744 2745 public CompoundScope membersClosure(Type site, boolean skipInterface) { 2746 CompoundScope cs = membersCache.visit(site, null); 2747 Assert.checkNonNull(cs, () -> "type " + site); 2748 return skipInterface ? membersCache.new MembersScope(cs) : cs; 2749 } 2750 // </editor-fold> 2751 2752 2753 /** Return first abstract member of class `sym'. 2754 */ 2755 public MethodSymbol firstUnimplementedAbstract(ClassSymbol sym) { 2756 try { 2757 return firstUnimplementedAbstractImpl(sym, sym); 2758 } catch (CompletionFailure ex) { 2759 chk.completionError(enter.getEnv(sym).tree.pos(), ex); 2760 return null; 2761 } 2762 } 2763 //where: 2764 private MethodSymbol firstUnimplementedAbstractImpl(ClassSymbol impl, ClassSymbol c) { 2765 MethodSymbol undef = null; 2766 // Do not bother to search in classes that are not abstract, 2767 // since they cannot have abstract members. 2768 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) { 2769 Scope s = c.members(); 2770 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) { 2771 if (sym.kind == MTH && 2772 (sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) { 2773 MethodSymbol absmeth = (MethodSymbol)sym; 2774 MethodSymbol implmeth = absmeth.implementation(impl, this, true); 2775 if (implmeth == null || implmeth == absmeth) { 2776 //look for default implementations 2777 if (allowDefaultMethods) { 2778 MethodSymbol prov = interfaceCandidates(impl.type, absmeth).head; 2779 if (prov != null && prov.overrides(absmeth, impl, this, true)) { 2780 implmeth = prov; 2781 } 2782 } 2783 } 2784 if (implmeth == null || implmeth == absmeth) { 2785 undef = absmeth; 2786 break; 2787 } 2788 } 2789 } 2790 if (undef == null) { 2791 Type st = supertype(c.type); 2792 if (st.hasTag(CLASS)) 2793 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)st.tsym); 2794 } 2795 for (List<Type> l = interfaces(c.type); 2796 undef == null && l.nonEmpty(); 2797 l = l.tail) { 2798 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)l.head.tsym); 2799 } 2800 } 2801 return undef; 2802 } 2803 2804 2805 //where 2806 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) { 2807 Filter<Symbol> filter = new MethodFilter(ms, site); 2808 List<MethodSymbol> candidates = List.nil(); 2809 for (Symbol s : membersClosure(site, false).getSymbols(filter)) { 2810 if (!site.tsym.isInterface() && !s.owner.isInterface()) { 2811 return List.of((MethodSymbol)s); 2812 } else if (!candidates.contains(s)) { 2813 candidates = candidates.prepend((MethodSymbol)s); 2814 } 2815 } 2816 return prune(candidates); 2817 } 2818 2819 public List<MethodSymbol> prune(List<MethodSymbol> methods) { 2820 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>(); 2821 for (MethodSymbol m1 : methods) { 2822 boolean isMin_m1 = true; 2823 for (MethodSymbol m2 : methods) { 2824 if (m1 == m2) continue; 2825 if (m2.owner != m1.owner && 2826 asSuper(m2.owner.type, m1.owner) != null) { 2827 isMin_m1 = false; 2828 break; 2829 } 2830 } 2831 if (isMin_m1) 2832 methodsMin.append(m1); 2833 } 2834 return methodsMin.toList(); 2835 } 2836 // where 2837 private class MethodFilter implements Filter<Symbol> { 2838 2839 Symbol msym; 2840 Type site; 2841 2842 MethodFilter(Symbol msym, Type site) { 2843 this.msym = msym; 2844 this.site = site; 2845 } 2846 2847 public boolean accepts(Symbol s) { 2848 return s.kind == MTH && 2849 s.name == msym.name && 2850 (s.flags() & SYNTHETIC) == 0 && 2851 s.isInheritedIn(site.tsym, Types.this) && 2852 overrideEquivalent(memberType(site, s), memberType(site, msym)); 2853 } 2854 } 2855 // </editor-fold> 2856 2857 /** 2858 * Does t have the same arguments as s? It is assumed that both 2859 * types are (possibly polymorphic) method types. Monomorphic 2860 * method types "have the same arguments", if their argument lists 2861 * are equal. Polymorphic method types "have the same arguments", 2862 * if they have the same arguments after renaming all type 2863 * variables of one to corresponding type variables in the other, 2864 * where correspondence is by position in the type parameter list. 2865 */ 2866 public boolean hasSameArgs(Type t, Type s) { 2867 return hasSameArgs(t, s, true); 2868 } 2869 2870 public boolean hasSameArgs(Type t, Type s, boolean strict) { 2871 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict); 2872 } 2873 2874 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) { 2875 return hasSameArgs.visit(t, s); 2876 } 2877 // where 2878 private class HasSameArgs extends TypeRelation { 2879 2880 boolean strict; 2881 2882 public HasSameArgs(boolean strict) { 2883 this.strict = strict; 2884 } 2885 2886 public Boolean visitType(Type t, Type s) { 2887 throw new AssertionError(); 2888 } 2889 2890 @Override 2891 public Boolean visitMethodType(MethodType t, Type s) { 2892 return s.hasTag(METHOD) 2893 && containsTypeEquivalent(t.argtypes, s.getParameterTypes()); 2894 } 2895 2896 @Override 2897 public Boolean visitForAll(ForAll t, Type s) { 2898 if (!s.hasTag(FORALL)) 2899 return strict ? false : visitMethodType(t.asMethodType(), s); 2900 2901 ForAll forAll = (ForAll)s; 2902 return hasSameBounds(t, forAll) 2903 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); 2904 } 2905 2906 @Override 2907 public Boolean visitErrorType(ErrorType t, Type s) { 2908 return false; 2909 } 2910 } 2911 2912 TypeRelation hasSameArgs_strict = new HasSameArgs(true); 2913 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false); 2914 2915 // </editor-fold> 2916 2917 // <editor-fold defaultstate="collapsed" desc="subst"> 2918 public List<Type> subst(List<Type> ts, 2919 List<Type> from, 2920 List<Type> to) { 2921 return ts.map(new Subst(from, to)); 2922 } 2923 2924 /** 2925 * Substitute all occurrences of a type in `from' with the 2926 * corresponding type in `to' in 't'. Match lists `from' and `to' 2927 * from the right: If lists have different length, discard leading 2928 * elements of the longer list. 2929 */ 2930 public Type subst(Type t, List<Type> from, List<Type> to) { 2931 return t.map(new Subst(from, to)); 2932 } 2933 2934 private class Subst extends TypeMapping<Void> { 2935 List<Type> from; 2936 List<Type> to; 2937 2938 public Subst(List<Type> from, List<Type> to) { 2939 int fromLength = from.length(); 2940 int toLength = to.length(); 2941 while (fromLength > toLength) { 2942 fromLength--; 2943 from = from.tail; 2944 } 2945 while (fromLength < toLength) { 2946 toLength--; 2947 to = to.tail; 2948 } 2949 this.from = from; 2950 this.to = to; 2951 } 2952 2953 @Override 2954 public Type visitTypeVar(TypeVar t, Void ignored) { 2955 for (List<Type> from = this.from, to = this.to; 2956 from.nonEmpty(); 2957 from = from.tail, to = to.tail) { 2958 if (t.equalsIgnoreMetadata(from.head)) { 2959 return to.head.withTypeVar(t); 2960 } 2961 } 2962 return t; 2963 } 2964 2965 @Override 2966 public Type visitClassType(ClassType t, Void ignored) { 2967 if (!t.isCompound()) { 2968 return super.visitClassType(t, ignored); 2969 } else { 2970 Type st = visit(supertype(t)); 2971 List<Type> is = visit(interfaces(t), ignored); 2972 if (st == supertype(t) && is == interfaces(t)) 2973 return t; 2974 else 2975 return makeIntersectionType(is.prepend(st)); 2976 } 2977 } 2978 2979 @Override 2980 public Type visitWildcardType(WildcardType t, Void ignored) { 2981 WildcardType t2 = (WildcardType)super.visitWildcardType(t, ignored); 2982 if (t2 != t && t.isExtendsBound() && t2.type.isExtendsBound()) { 2983 t2.type = wildUpperBound(t2.type); 2984 } 2985 return t2; 2986 } 2987 2988 @Override 2989 public Type visitForAll(ForAll t, Void ignored) { 2990 if (Type.containsAny(to, t.tvars)) { 2991 //perform alpha-renaming of free-variables in 't' 2992 //if 'to' types contain variables that are free in 't' 2993 List<Type> freevars = newInstances(t.tvars); 2994 t = new ForAll(freevars, 2995 Types.this.subst(t.qtype, t.tvars, freevars)); 2996 } 2997 List<Type> tvars1 = substBounds(t.tvars, from, to); 2998 Type qtype1 = visit(t.qtype); 2999 if (tvars1 == t.tvars && qtype1 == t.qtype) { 3000 return t; 3001 } else if (tvars1 == t.tvars) { 3002 return new ForAll(tvars1, qtype1) { 3003 @Override 3004 public boolean needsStripping() { 3005 return true; 3006 } 3007 }; 3008 } else { 3009 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1)) { 3010 @Override 3011 public boolean needsStripping() { 3012 return true; 3013 } 3014 }; 3015 } 3016 } 3017 } 3018 3019 public List<Type> substBounds(List<Type> tvars, 3020 List<Type> from, 3021 List<Type> to) { 3022 if (tvars.isEmpty()) 3023 return tvars; 3024 ListBuffer<Type> newBoundsBuf = new ListBuffer<>(); 3025 boolean changed = false; 3026 // calculate new bounds 3027 for (Type t : tvars) { 3028 TypeVar tv = (TypeVar) t; 3029 Type bound = subst(tv.bound, from, to); 3030 if (bound != tv.bound) 3031 changed = true; 3032 newBoundsBuf.append(bound); 3033 } 3034 if (!changed) 3035 return tvars; 3036 ListBuffer<Type> newTvars = new ListBuffer<>(); 3037 // create new type variables without bounds 3038 for (Type t : tvars) { 3039 newTvars.append(new TypeVar(t.tsym, null, syms.botType, 3040 t.getMetadata())); 3041 } 3042 // the new bounds should use the new type variables in place 3043 // of the old 3044 List<Type> newBounds = newBoundsBuf.toList(); 3045 from = tvars; 3046 to = newTvars.toList(); 3047 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) { 3048 newBounds.head = subst(newBounds.head, from, to); 3049 } 3050 newBounds = newBoundsBuf.toList(); 3051 // set the bounds of new type variables to the new bounds 3052 for (Type t : newTvars.toList()) { 3053 TypeVar tv = (TypeVar) t; 3054 tv.bound = newBounds.head; 3055 newBounds = newBounds.tail; 3056 } 3057 return newTvars.toList(); 3058 } 3059 3060 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) { 3061 Type bound1 = subst(t.bound, from, to); 3062 if (bound1 == t.bound) 3063 return t; 3064 else { 3065 // create new type variable without bounds 3066 TypeVar tv = new TypeVar(t.tsym, null, syms.botType, 3067 t.getMetadata()); 3068 // the new bound should use the new type variable in place 3069 // of the old 3070 tv.bound = subst(bound1, List.<Type>of(t), List.<Type>of(tv)); 3071 return tv; 3072 } 3073 } 3074 // </editor-fold> 3075 3076 // <editor-fold defaultstate="collapsed" desc="hasSameBounds"> 3077 /** 3078 * Does t have the same bounds for quantified variables as s? 3079 */ 3080 public boolean hasSameBounds(ForAll t, ForAll s) { 3081 List<Type> l1 = t.tvars; 3082 List<Type> l2 = s.tvars; 3083 while (l1.nonEmpty() && l2.nonEmpty() && 3084 isSameType(l1.head.getUpperBound(), 3085 subst(l2.head.getUpperBound(), 3086 s.tvars, 3087 t.tvars))) { 3088 l1 = l1.tail; 3089 l2 = l2.tail; 3090 } 3091 return l1.isEmpty() && l2.isEmpty(); 3092 } 3093 // </editor-fold> 3094 3095 // <editor-fold defaultstate="collapsed" desc="newInstances"> 3096 /** Create new vector of type variables from list of variables 3097 * changing all recursive bounds from old to new list. 3098 */ 3099 public List<Type> newInstances(List<Type> tvars) { 3100 List<Type> tvars1 = tvars.map(newInstanceFun); 3101 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) { 3102 TypeVar tv = (TypeVar) l.head; 3103 tv.bound = subst(tv.bound, tvars, tvars1); 3104 } 3105 return tvars1; 3106 } 3107 private static final TypeMapping<Void> newInstanceFun = new TypeMapping<Void>() { 3108 @Override 3109 public TypeVar visitTypeVar(TypeVar t, Void _unused) { 3110 return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound(), t.getMetadata()); 3111 } 3112 }; 3113 // </editor-fold> 3114 3115 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) { 3116 return original.accept(methodWithParameters, newParams); 3117 } 3118 // where 3119 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() { 3120 public Type visitType(Type t, List<Type> newParams) { 3121 throw new IllegalArgumentException("Not a method type: " + t); 3122 } 3123 public Type visitMethodType(MethodType t, List<Type> newParams) { 3124 return new MethodType(newParams, t.restype, t.thrown, t.tsym); 3125 } 3126 public Type visitForAll(ForAll t, List<Type> newParams) { 3127 return new ForAll(t.tvars, t.qtype.accept(this, newParams)); 3128 } 3129 }; 3130 3131 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) { 3132 return original.accept(methodWithThrown, newThrown); 3133 } 3134 // where 3135 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() { 3136 public Type visitType(Type t, List<Type> newThrown) { 3137 throw new IllegalArgumentException("Not a method type: " + t); 3138 } 3139 public Type visitMethodType(MethodType t, List<Type> newThrown) { 3140 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym); 3141 } 3142 public Type visitForAll(ForAll t, List<Type> newThrown) { 3143 return new ForAll(t.tvars, t.qtype.accept(this, newThrown)); 3144 } 3145 }; 3146 3147 public Type createMethodTypeWithReturn(Type original, Type newReturn) { 3148 return original.accept(methodWithReturn, newReturn); 3149 } 3150 // where 3151 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() { 3152 public Type visitType(Type t, Type newReturn) { 3153 throw new IllegalArgumentException("Not a method type: " + t); 3154 } 3155 public Type visitMethodType(MethodType t, Type newReturn) { 3156 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym) { 3157 @Override 3158 public Type baseType() { 3159 return t; 3160 } 3161 }; 3162 } 3163 public Type visitForAll(ForAll t, Type newReturn) { 3164 return new ForAll(t.tvars, t.qtype.accept(this, newReturn)) { 3165 @Override 3166 public Type baseType() { 3167 return t; 3168 } 3169 }; 3170 } 3171 }; 3172 3173 // <editor-fold defaultstate="collapsed" desc="createErrorType"> 3174 public Type createErrorType(Type originalType) { 3175 return new ErrorType(originalType, syms.errSymbol); 3176 } 3177 3178 public Type createErrorType(ClassSymbol c, Type originalType) { 3179 return new ErrorType(c, originalType); 3180 } 3181 3182 public Type createErrorType(Name name, TypeSymbol container, Type originalType) { 3183 return new ErrorType(name, container, originalType); 3184 } 3185 // </editor-fold> 3186 3187 // <editor-fold defaultstate="collapsed" desc="rank"> 3188 /** 3189 * The rank of a class is the length of the longest path between 3190 * the class and java.lang.Object in the class inheritance 3191 * graph. Undefined for all but reference types. 3192 */ 3193 public int rank(Type t) { 3194 switch(t.getTag()) { 3195 case CLASS: { 3196 ClassType cls = (ClassType)t; 3197 if (cls.rank_field < 0) { 3198 Name fullname = cls.tsym.getQualifiedName(); 3199 if (fullname == names.java_lang_Object) 3200 cls.rank_field = 0; 3201 else { 3202 int r = rank(supertype(cls)); 3203 for (List<Type> l = interfaces(cls); 3204 l.nonEmpty(); 3205 l = l.tail) { 3206 if (rank(l.head) > r) 3207 r = rank(l.head); 3208 } 3209 cls.rank_field = r + 1; 3210 } 3211 } 3212 return cls.rank_field; 3213 } 3214 case TYPEVAR: { 3215 TypeVar tvar = (TypeVar)t; 3216 if (tvar.rank_field < 0) { 3217 int r = rank(supertype(tvar)); 3218 for (List<Type> l = interfaces(tvar); 3219 l.nonEmpty(); 3220 l = l.tail) { 3221 if (rank(l.head) > r) r = rank(l.head); 3222 } 3223 tvar.rank_field = r + 1; 3224 } 3225 return tvar.rank_field; 3226 } 3227 case ERROR: 3228 case NONE: 3229 return 0; 3230 default: 3231 throw new AssertionError(); 3232 } 3233 } 3234 // </editor-fold> 3235 3236 /** 3237 * Helper method for generating a string representation of a given type 3238 * accordingly to a given locale 3239 */ 3240 public String toString(Type t, Locale locale) { 3241 return Printer.createStandardPrinter(messages).visit(t, locale); 3242 } 3243 3244 /** 3245 * Helper method for generating a string representation of a given type 3246 * accordingly to a given locale 3247 */ 3248 public String toString(Symbol t, Locale locale) { 3249 return Printer.createStandardPrinter(messages).visit(t, locale); 3250 } 3251 3252 // <editor-fold defaultstate="collapsed" desc="toString"> 3253 /** 3254 * This toString is slightly more descriptive than the one on Type. 3255 * 3256 * @deprecated Types.toString(Type t, Locale l) provides better support 3257 * for localization 3258 */ 3259 @Deprecated 3260 public String toString(Type t) { 3261 if (t.hasTag(FORALL)) { 3262 ForAll forAll = (ForAll)t; 3263 return typaramsString(forAll.tvars) + forAll.qtype; 3264 } 3265 return "" + t; 3266 } 3267 // where 3268 private String typaramsString(List<Type> tvars) { 3269 StringBuilder s = new StringBuilder(); 3270 s.append('<'); 3271 boolean first = true; 3272 for (Type t : tvars) { 3273 if (!first) s.append(", "); 3274 first = false; 3275 appendTyparamString(((TypeVar)t), s); 3276 } 3277 s.append('>'); 3278 return s.toString(); 3279 } 3280 private void appendTyparamString(TypeVar t, StringBuilder buf) { 3281 buf.append(t); 3282 if (t.bound == null || 3283 t.bound.tsym.getQualifiedName() == names.java_lang_Object) 3284 return; 3285 buf.append(" extends "); // Java syntax; no need for i18n 3286 Type bound = t.bound; 3287 if (!bound.isCompound()) { 3288 buf.append(bound); 3289 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) { 3290 buf.append(supertype(t)); 3291 for (Type intf : interfaces(t)) { 3292 buf.append('&'); 3293 buf.append(intf); 3294 } 3295 } else { 3296 // No superclass was given in bounds. 3297 // In this case, supertype is Object, erasure is first interface. 3298 boolean first = true; 3299 for (Type intf : interfaces(t)) { 3300 if (!first) buf.append('&'); 3301 first = false; 3302 buf.append(intf); 3303 } 3304 } 3305 } 3306 // </editor-fold> 3307 3308 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types"> 3309 /** 3310 * A cache for closures. 3311 * 3312 * <p>A closure is a list of all the supertypes and interfaces of 3313 * a class or interface type, ordered by ClassSymbol.precedes 3314 * (that is, subclasses come first, arbitrary but fixed 3315 * otherwise). 3316 */ 3317 private Map<Type,List<Type>> closureCache = new HashMap<>(); 3318 3319 /** 3320 * Returns the closure of a class or interface type. 3321 */ 3322 public List<Type> closure(Type t) { 3323 List<Type> cl = closureCache.get(t); 3324 if (cl == null) { 3325 Type st = supertype(t); 3326 if (!t.isCompound()) { 3327 if (st.hasTag(CLASS)) { 3328 cl = insert(closure(st), t); 3329 } else if (st.hasTag(TYPEVAR)) { 3330 cl = closure(st).prepend(t); 3331 } else { 3332 cl = List.of(t); 3333 } 3334 } else { 3335 cl = closure(supertype(t)); 3336 } 3337 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) 3338 cl = union(cl, closure(l.head)); 3339 closureCache.put(t, cl); 3340 } 3341 return cl; 3342 } 3343 3344 /** 3345 * Collect types into a new closure (using a @code{ClosureHolder}) 3346 */ 3347 public Collector<Type, ClosureHolder, List<Type>> closureCollector(boolean minClosure, BiPredicate<Type, Type> shouldSkip) { 3348 return Collector.of(() -> new ClosureHolder(minClosure, shouldSkip), 3349 ClosureHolder::add, 3350 ClosureHolder::merge, 3351 ClosureHolder::closure); 3352 } 3353 //where 3354 class ClosureHolder { 3355 List<Type> closure; 3356 final boolean minClosure; 3357 final BiPredicate<Type, Type> shouldSkip; 3358 3359 ClosureHolder(boolean minClosure, BiPredicate<Type, Type> shouldSkip) { 3360 this.closure = List.nil(); 3361 this.minClosure = minClosure; 3362 this.shouldSkip = shouldSkip; 3363 } 3364 3365 void add(Type type) { 3366 closure = insert(closure, type, shouldSkip); 3367 } 3368 3369 ClosureHolder merge(ClosureHolder other) { 3370 closure = union(closure, other.closure, shouldSkip); 3371 return this; 3372 } 3373 3374 List<Type> closure() { 3375 return minClosure ? closureMin(closure) : closure; 3376 } 3377 } 3378 3379 BiPredicate<Type, Type> basicClosureSkip = (t1, t2) -> t1.tsym == t2.tsym; 3380 3381 /** 3382 * Insert a type in a closure 3383 */ 3384 public List<Type> insert(List<Type> cl, Type t, BiPredicate<Type, Type> shouldSkip) { 3385 if (cl.isEmpty()) { 3386 return cl.prepend(t); 3387 } else if (shouldSkip.test(t, cl.head)) { 3388 return cl; 3389 } else if (t.tsym.precedes(cl.head.tsym, this)) { 3390 return cl.prepend(t); 3391 } else { 3392 // t comes after head, or the two are unrelated 3393 return insert(cl.tail, t, shouldSkip).prepend(cl.head); 3394 } 3395 } 3396 3397 public List<Type> insert(List<Type> cl, Type t) { 3398 return insert(cl, t, basicClosureSkip); 3399 } 3400 3401 /** 3402 * Form the union of two closures 3403 */ 3404 public List<Type> union(List<Type> cl1, List<Type> cl2, BiPredicate<Type, Type> shouldSkip) { 3405 if (cl1.isEmpty()) { 3406 return cl2; 3407 } else if (cl2.isEmpty()) { 3408 return cl1; 3409 } else if (shouldSkip.test(cl1.head, cl2.head)) { 3410 return union(cl1.tail, cl2.tail, shouldSkip).prepend(cl1.head); 3411 } else if (cl1.head.tsym.precedes(cl2.head.tsym, this)) { 3412 return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head); 3413 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) { 3414 return union(cl1, cl2.tail, shouldSkip).prepend(cl2.head); 3415 } else { 3416 // unrelated types 3417 return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head); 3418 } 3419 } 3420 3421 public List<Type> union(List<Type> cl1, List<Type> cl2) { 3422 return union(cl1, cl2, basicClosureSkip); 3423 } 3424 3425 /** 3426 * Intersect two closures 3427 */ 3428 public List<Type> intersect(List<Type> cl1, List<Type> cl2) { 3429 if (cl1 == cl2) 3430 return cl1; 3431 if (cl1.isEmpty() || cl2.isEmpty()) 3432 return List.nil(); 3433 if (cl1.head.tsym.precedes(cl2.head.tsym, this)) 3434 return intersect(cl1.tail, cl2); 3435 if (cl2.head.tsym.precedes(cl1.head.tsym, this)) 3436 return intersect(cl1, cl2.tail); 3437 if (isSameType(cl1.head, cl2.head)) 3438 return intersect(cl1.tail, cl2.tail).prepend(cl1.head); 3439 if (cl1.head.tsym == cl2.head.tsym && 3440 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) { 3441 if (cl1.head.isParameterized() && cl2.head.isParameterized()) { 3442 Type merge = merge(cl1.head,cl2.head); 3443 return intersect(cl1.tail, cl2.tail).prepend(merge); 3444 } 3445 if (cl1.head.isRaw() || cl2.head.isRaw()) 3446 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head)); 3447 } 3448 return intersect(cl1.tail, cl2.tail); 3449 } 3450 // where 3451 class TypePair { 3452 final Type t1; 3453 final Type t2; 3454 boolean strict; 3455 3456 TypePair(Type t1, Type t2) { 3457 this(t1, t2, false); 3458 } 3459 3460 TypePair(Type t1, Type t2, boolean strict) { 3461 this.t1 = t1; 3462 this.t2 = t2; 3463 this.strict = strict; 3464 } 3465 @Override 3466 public int hashCode() { 3467 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2); 3468 } 3469 @Override 3470 public boolean equals(Object obj) { 3471 if (!(obj instanceof TypePair)) 3472 return false; 3473 TypePair typePair = (TypePair)obj; 3474 return isSameType(t1, typePair.t1, strict) 3475 && isSameType(t2, typePair.t2, strict); 3476 } 3477 } 3478 Set<TypePair> mergeCache = new HashSet<>(); 3479 private Type merge(Type c1, Type c2) { 3480 ClassType class1 = (ClassType) c1; 3481 List<Type> act1 = class1.getTypeArguments(); 3482 ClassType class2 = (ClassType) c2; 3483 List<Type> act2 = class2.getTypeArguments(); 3484 ListBuffer<Type> merged = new ListBuffer<>(); 3485 List<Type> typarams = class1.tsym.type.getTypeArguments(); 3486 3487 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) { 3488 if (containsType(act1.head, act2.head)) { 3489 merged.append(act1.head); 3490 } else if (containsType(act2.head, act1.head)) { 3491 merged.append(act2.head); 3492 } else { 3493 TypePair pair = new TypePair(c1, c2); 3494 Type m; 3495 if (mergeCache.add(pair)) { 3496 m = new WildcardType(lub(wildUpperBound(act1.head), 3497 wildUpperBound(act2.head)), 3498 BoundKind.EXTENDS, 3499 syms.boundClass); 3500 mergeCache.remove(pair); 3501 } else { 3502 m = new WildcardType(syms.objectType, 3503 BoundKind.UNBOUND, 3504 syms.boundClass); 3505 } 3506 merged.append(m.withTypeVar(typarams.head)); 3507 } 3508 act1 = act1.tail; 3509 act2 = act2.tail; 3510 typarams = typarams.tail; 3511 } 3512 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty()); 3513 // There is no spec detailing how type annotations are to 3514 // be inherited. So set it to noAnnotations for now 3515 return new ClassType(class1.getEnclosingType(), merged.toList(), 3516 class1.tsym); 3517 } 3518 3519 /** 3520 * Return the minimum type of a closure, a compound type if no 3521 * unique minimum exists. 3522 */ 3523 private Type compoundMin(List<Type> cl) { 3524 if (cl.isEmpty()) return syms.objectType; 3525 List<Type> compound = closureMin(cl); 3526 if (compound.isEmpty()) 3527 return null; 3528 else if (compound.tail.isEmpty()) 3529 return compound.head; 3530 else 3531 return makeIntersectionType(compound); 3532 } 3533 3534 /** 3535 * Return the minimum types of a closure, suitable for computing 3536 * compoundMin or glb. 3537 */ 3538 private List<Type> closureMin(List<Type> cl) { 3539 ListBuffer<Type> classes = new ListBuffer<>(); 3540 ListBuffer<Type> interfaces = new ListBuffer<>(); 3541 Set<Type> toSkip = new HashSet<>(); 3542 while (!cl.isEmpty()) { 3543 Type current = cl.head; 3544 boolean keep = !toSkip.contains(current); 3545 if (keep && current.hasTag(TYPEVAR)) { 3546 // skip lower-bounded variables with a subtype in cl.tail 3547 for (Type t : cl.tail) { 3548 if (isSubtypeNoCapture(t, current)) { 3549 keep = false; 3550 break; 3551 } 3552 } 3553 } 3554 if (keep) { 3555 if (current.isInterface()) 3556 interfaces.append(current); 3557 else 3558 classes.append(current); 3559 for (Type t : cl.tail) { 3560 // skip supertypes of 'current' in cl.tail 3561 if (isSubtypeNoCapture(current, t)) 3562 toSkip.add(t); 3563 } 3564 } 3565 cl = cl.tail; 3566 } 3567 return classes.appendList(interfaces).toList(); 3568 } 3569 3570 /** 3571 * Return the least upper bound of list of types. if the lub does 3572 * not exist return null. 3573 */ 3574 public Type lub(List<Type> ts) { 3575 return lub(ts.toArray(new Type[ts.length()])); 3576 } 3577 3578 /** 3579 * Return the least upper bound (lub) of set of types. If the lub 3580 * does not exist return the type of null (bottom). 3581 */ 3582 public Type lub(Type... ts) { 3583 final int UNKNOWN_BOUND = 0; 3584 final int ARRAY_BOUND = 1; 3585 final int CLASS_BOUND = 2; 3586 3587 int[] kinds = new int[ts.length]; 3588 3589 int boundkind = UNKNOWN_BOUND; 3590 for (int i = 0 ; i < ts.length ; i++) { 3591 Type t = ts[i]; 3592 switch (t.getTag()) { 3593 case CLASS: 3594 boundkind |= kinds[i] = CLASS_BOUND; 3595 break; 3596 case ARRAY: 3597 boundkind |= kinds[i] = ARRAY_BOUND; 3598 break; 3599 case TYPEVAR: 3600 do { 3601 t = t.getUpperBound(); 3602 } while (t.hasTag(TYPEVAR)); 3603 if (t.hasTag(ARRAY)) { 3604 boundkind |= kinds[i] = ARRAY_BOUND; 3605 } else { 3606 boundkind |= kinds[i] = CLASS_BOUND; 3607 } 3608 break; 3609 default: 3610 kinds[i] = UNKNOWN_BOUND; 3611 if (t.isPrimitive()) 3612 return syms.errType; 3613 } 3614 } 3615 switch (boundkind) { 3616 case 0: 3617 return syms.botType; 3618 3619 case ARRAY_BOUND: 3620 // calculate lub(A[], B[]) 3621 Type[] elements = new Type[ts.length]; 3622 for (int i = 0 ; i < ts.length ; i++) { 3623 Type elem = elements[i] = elemTypeFun.apply(ts[i]); 3624 if (elem.isPrimitive()) { 3625 // if a primitive type is found, then return 3626 // arraySuperType unless all the types are the 3627 // same 3628 Type first = ts[0]; 3629 for (int j = 1 ; j < ts.length ; j++) { 3630 if (!isSameType(first, ts[j])) { 3631 // lub(int[], B[]) is Cloneable & Serializable 3632 return arraySuperType(); 3633 } 3634 } 3635 // all the array types are the same, return one 3636 // lub(int[], int[]) is int[] 3637 return first; 3638 } 3639 } 3640 // lub(A[], B[]) is lub(A, B)[] 3641 return new ArrayType(lub(elements), syms.arrayClass); 3642 3643 case CLASS_BOUND: 3644 // calculate lub(A, B) 3645 int startIdx = 0; 3646 for (int i = 0; i < ts.length ; i++) { 3647 Type t = ts[i]; 3648 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) { 3649 break; 3650 } else { 3651 startIdx++; 3652 } 3653 } 3654 Assert.check(startIdx < ts.length); 3655 //step 1 - compute erased candidate set (EC) 3656 List<Type> cl = erasedSupertypes(ts[startIdx]); 3657 for (int i = startIdx + 1 ; i < ts.length ; i++) { 3658 Type t = ts[i]; 3659 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) 3660 cl = intersect(cl, erasedSupertypes(t)); 3661 } 3662 //step 2 - compute minimal erased candidate set (MEC) 3663 List<Type> mec = closureMin(cl); 3664 //step 3 - for each element G in MEC, compute lci(Inv(G)) 3665 List<Type> candidates = List.nil(); 3666 for (Type erasedSupertype : mec) { 3667 List<Type> lci = List.of(asSuper(ts[startIdx], erasedSupertype.tsym)); 3668 for (int i = startIdx + 1 ; i < ts.length ; i++) { 3669 Type superType = asSuper(ts[i], erasedSupertype.tsym); 3670 lci = intersect(lci, superType != null ? List.of(superType) : List.<Type>nil()); 3671 } 3672 candidates = candidates.appendList(lci); 3673 } 3674 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that 3675 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn)) 3676 return compoundMin(candidates); 3677 3678 default: 3679 // calculate lub(A, B[]) 3680 List<Type> classes = List.of(arraySuperType()); 3681 for (int i = 0 ; i < ts.length ; i++) { 3682 if (kinds[i] != ARRAY_BOUND) // Filter out any arrays 3683 classes = classes.prepend(ts[i]); 3684 } 3685 // lub(A, B[]) is lub(A, arraySuperType) 3686 return lub(classes); 3687 } 3688 } 3689 // where 3690 List<Type> erasedSupertypes(Type t) { 3691 ListBuffer<Type> buf = new ListBuffer<>(); 3692 for (Type sup : closure(t)) { 3693 if (sup.hasTag(TYPEVAR)) { 3694 buf.append(sup); 3695 } else { 3696 buf.append(erasure(sup)); 3697 } 3698 } 3699 return buf.toList(); 3700 } 3701 3702 private Type arraySuperType = null; 3703 private Type arraySuperType() { 3704 // initialized lazily to avoid problems during compiler startup 3705 if (arraySuperType == null) { 3706 synchronized (this) { 3707 if (arraySuperType == null) { 3708 // JLS 10.8: all arrays implement Cloneable and Serializable. 3709 arraySuperType = makeIntersectionType(List.of(syms.serializableType, 3710 syms.cloneableType), true); 3711 } 3712 } 3713 } 3714 return arraySuperType; 3715 } 3716 // </editor-fold> 3717 3718 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound"> 3719 public Type glb(List<Type> ts) { 3720 Type t1 = ts.head; 3721 for (Type t2 : ts.tail) { 3722 if (t1.isErroneous()) 3723 return t1; 3724 t1 = glb(t1, t2); 3725 } 3726 return t1; 3727 } 3728 //where 3729 public Type glb(Type t, Type s) { 3730 if (s == null) 3731 return t; 3732 else if (t.isPrimitive() || s.isPrimitive()) 3733 return syms.errType; 3734 else if (isSubtypeNoCapture(t, s)) 3735 return t; 3736 else if (isSubtypeNoCapture(s, t)) 3737 return s; 3738 3739 List<Type> closure = union(closure(t), closure(s)); 3740 return glbFlattened(closure, t); 3741 } 3742 //where 3743 /** 3744 * Perform glb for a list of non-primitive, non-error, non-compound types; 3745 * redundant elements are removed. Bounds should be ordered according to 3746 * {@link Symbol#precedes(TypeSymbol,Types)}. 3747 * 3748 * @param flatBounds List of type to glb 3749 * @param errT Original type to use if the result is an error type 3750 */ 3751 private Type glbFlattened(List<Type> flatBounds, Type errT) { 3752 List<Type> bounds = closureMin(flatBounds); 3753 3754 if (bounds.isEmpty()) { // length == 0 3755 return syms.objectType; 3756 } else if (bounds.tail.isEmpty()) { // length == 1 3757 return bounds.head; 3758 } else { // length > 1 3759 int classCount = 0; 3760 List<Type> lowers = List.nil(); 3761 for (Type bound : bounds) { 3762 if (!bound.isInterface()) { 3763 classCount++; 3764 Type lower = cvarLowerBound(bound); 3765 if (bound != lower && !lower.hasTag(BOT)) 3766 lowers = insert(lowers, lower); 3767 } 3768 } 3769 if (classCount > 1) { 3770 if (lowers.isEmpty()) 3771 return createErrorType(errT); 3772 else 3773 return glbFlattened(union(bounds, lowers), errT); 3774 } 3775 } 3776 return makeIntersectionType(bounds); 3777 } 3778 // </editor-fold> 3779 3780 // <editor-fold defaultstate="collapsed" desc="hashCode"> 3781 /** 3782 * Compute a hash code on a type. 3783 */ 3784 public int hashCode(Type t) { 3785 return hashCode(t, false); 3786 } 3787 3788 public int hashCode(Type t, boolean strict) { 3789 return strict ? 3790 hashCodeStrictVisitor.visit(t) : 3791 hashCodeVisitor.visit(t); 3792 } 3793 // where 3794 private static final HashCodeVisitor hashCodeVisitor = new HashCodeVisitor(); 3795 private static final HashCodeVisitor hashCodeStrictVisitor = new HashCodeVisitor() { 3796 @Override 3797 public Integer visitTypeVar(TypeVar t, Void ignored) { 3798 return System.identityHashCode(t); 3799 } 3800 }; 3801 3802 private static class HashCodeVisitor extends UnaryVisitor<Integer> { 3803 public Integer visitType(Type t, Void ignored) { 3804 return t.getTag().ordinal(); 3805 } 3806 3807 @Override 3808 public Integer visitClassType(ClassType t, Void ignored) { 3809 int result = visit(t.getEnclosingType()); 3810 result *= 127; 3811 result += t.tsym.flatName().hashCode(); 3812 for (Type s : t.getTypeArguments()) { 3813 result *= 127; 3814 result += visit(s); 3815 } 3816 return result; 3817 } 3818 3819 @Override 3820 public Integer visitMethodType(MethodType t, Void ignored) { 3821 int h = METHOD.ordinal(); 3822 for (List<Type> thisargs = t.argtypes; 3823 thisargs.tail != null; 3824 thisargs = thisargs.tail) 3825 h = (h << 5) + visit(thisargs.head); 3826 return (h << 5) + visit(t.restype); 3827 } 3828 3829 @Override 3830 public Integer visitWildcardType(WildcardType t, Void ignored) { 3831 int result = t.kind.hashCode(); 3832 if (t.type != null) { 3833 result *= 127; 3834 result += visit(t.type); 3835 } 3836 return result; 3837 } 3838 3839 @Override 3840 public Integer visitArrayType(ArrayType t, Void ignored) { 3841 return visit(t.elemtype) + 12; 3842 } 3843 3844 @Override 3845 public Integer visitTypeVar(TypeVar t, Void ignored) { 3846 return System.identityHashCode(t); 3847 } 3848 3849 @Override 3850 public Integer visitUndetVar(UndetVar t, Void ignored) { 3851 return System.identityHashCode(t); 3852 } 3853 3854 @Override 3855 public Integer visitErrorType(ErrorType t, Void ignored) { 3856 return 0; 3857 } 3858 } 3859 // </editor-fold> 3860 3861 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable"> 3862 /** 3863 * Does t have a result that is a subtype of the result type of s, 3864 * suitable for covariant returns? It is assumed that both types 3865 * are (possibly polymorphic) method types. Monomorphic method 3866 * types are handled in the obvious way. Polymorphic method types 3867 * require renaming all type variables of one to corresponding 3868 * type variables in the other, where correspondence is by 3869 * position in the type parameter list. */ 3870 public boolean resultSubtype(Type t, Type s, Warner warner) { 3871 List<Type> tvars = t.getTypeArguments(); 3872 List<Type> svars = s.getTypeArguments(); 3873 Type tres = t.getReturnType(); 3874 Type sres = subst(s.getReturnType(), svars, tvars); 3875 return covariantReturnType(tres, sres, warner); 3876 } 3877 3878 /** 3879 * Return-Type-Substitutable. 3880 * @jls section 8.4.5 3881 */ 3882 public boolean returnTypeSubstitutable(Type r1, Type r2) { 3883 if (hasSameArgs(r1, r2)) 3884 return resultSubtype(r1, r2, noWarnings); 3885 else 3886 return covariantReturnType(r1.getReturnType(), 3887 erasure(r2.getReturnType()), 3888 noWarnings); 3889 } 3890 3891 public boolean returnTypeSubstitutable(Type r1, 3892 Type r2, Type r2res, 3893 Warner warner) { 3894 if (isSameType(r1.getReturnType(), r2res)) 3895 return true; 3896 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive()) 3897 return false; 3898 3899 if (hasSameArgs(r1, r2)) 3900 return covariantReturnType(r1.getReturnType(), r2res, warner); 3901 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner)) 3902 return true; 3903 if (!isSubtype(r1.getReturnType(), erasure(r2res))) 3904 return false; 3905 warner.warn(LintCategory.UNCHECKED); 3906 return true; 3907 } 3908 3909 /** 3910 * Is t an appropriate return type in an overrider for a 3911 * method that returns s? 3912 */ 3913 public boolean covariantReturnType(Type t, Type s, Warner warner) { 3914 return 3915 isSameType(t, s) || 3916 !t.isPrimitive() && 3917 !s.isPrimitive() && 3918 isAssignable(t, s, warner); 3919 } 3920 // </editor-fold> 3921 3922 // <editor-fold defaultstate="collapsed" desc="Box/unbox support"> 3923 /** 3924 * Return the class that boxes the given primitive. 3925 */ 3926 public ClassSymbol boxedClass(Type t) { 3927 return syms.enterClass(syms.boxedName[t.getTag().ordinal()]); 3928 } 3929 3930 /** 3931 * Return the boxed type if 't' is primitive, otherwise return 't' itself. 3932 */ 3933 public Type boxedTypeOrType(Type t) { 3934 return t.isPrimitive() ? 3935 boxedClass(t).type : 3936 t; 3937 } 3938 3939 /** 3940 * Return the primitive type corresponding to a boxed type. 3941 */ 3942 public Type unboxedType(Type t) { 3943 for (int i=0; i<syms.boxedName.length; i++) { 3944 Name box = syms.boxedName[i]; 3945 if (box != null && 3946 asSuper(t, syms.enterClass(box)) != null) 3947 return syms.typeOfTag[i]; 3948 } 3949 return Type.noType; 3950 } 3951 3952 /** 3953 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself. 3954 */ 3955 public Type unboxedTypeOrType(Type t) { 3956 Type unboxedType = unboxedType(t); 3957 return unboxedType.hasTag(NONE) ? t : unboxedType; 3958 } 3959 // </editor-fold> 3960 3961 // <editor-fold defaultstate="collapsed" desc="Capture conversion"> 3962 /* 3963 * JLS 5.1.10 Capture Conversion: 3964 * 3965 * Let G name a generic type declaration with n formal type 3966 * parameters A1 ... An with corresponding bounds U1 ... Un. There 3967 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>, 3968 * where, for 1 <= i <= n: 3969 * 3970 * + If Ti is a wildcard type argument (4.5.1) of the form ? then 3971 * Si is a fresh type variable whose upper bound is 3972 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null 3973 * type. 3974 * 3975 * + If Ti is a wildcard type argument of the form ? extends Bi, 3976 * then Si is a fresh type variable whose upper bound is 3977 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is 3978 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is 3979 * a compile-time error if for any two classes (not interfaces) 3980 * Vi and Vj,Vi is not a subclass of Vj or vice versa. 3981 * 3982 * + If Ti is a wildcard type argument of the form ? super Bi, 3983 * then Si is a fresh type variable whose upper bound is 3984 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi. 3985 * 3986 * + Otherwise, Si = Ti. 3987 * 3988 * Capture conversion on any type other than a parameterized type 3989 * (4.5) acts as an identity conversion (5.1.1). Capture 3990 * conversions never require a special action at run time and 3991 * therefore never throw an exception at run time. 3992 * 3993 * Capture conversion is not applied recursively. 3994 */ 3995 /** 3996 * Capture conversion as specified by the JLS. 3997 */ 3998 3999 public List<Type> capture(List<Type> ts) { 4000 List<Type> buf = List.nil(); 4001 for (Type t : ts) { 4002 buf = buf.prepend(capture(t)); 4003 } 4004 return buf.reverse(); 4005 } 4006 4007 public Type capture(Type t) { 4008 if (!t.hasTag(CLASS)) { 4009 return t; 4010 } 4011 if (t.getEnclosingType() != Type.noType) { 4012 Type capturedEncl = capture(t.getEnclosingType()); 4013 if (capturedEncl != t.getEnclosingType()) { 4014 Type type1 = memberType(capturedEncl, t.tsym); 4015 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments()); 4016 } 4017 } 4018 ClassType cls = (ClassType)t; 4019 if (cls.isRaw() || !cls.isParameterized()) 4020 return cls; 4021 4022 ClassType G = (ClassType)cls.asElement().asType(); 4023 List<Type> A = G.getTypeArguments(); 4024 List<Type> T = cls.getTypeArguments(); 4025 List<Type> S = freshTypeVariables(T); 4026 4027 List<Type> currentA = A; 4028 List<Type> currentT = T; 4029 List<Type> currentS = S; 4030 boolean captured = false; 4031 while (!currentA.isEmpty() && 4032 !currentT.isEmpty() && 4033 !currentS.isEmpty()) { 4034 if (currentS.head != currentT.head) { 4035 captured = true; 4036 WildcardType Ti = (WildcardType)currentT.head; 4037 Type Ui = currentA.head.getUpperBound(); 4038 CapturedType Si = (CapturedType)currentS.head; 4039 if (Ui == null) 4040 Ui = syms.objectType; 4041 switch (Ti.kind) { 4042 case UNBOUND: 4043 Si.bound = subst(Ui, A, S); 4044 Si.lower = syms.botType; 4045 break; 4046 case EXTENDS: 4047 Si.bound = glb(Ti.getExtendsBound(), subst(Ui, A, S)); 4048 Si.lower = syms.botType; 4049 break; 4050 case SUPER: 4051 Si.bound = subst(Ui, A, S); 4052 Si.lower = Ti.getSuperBound(); 4053 break; 4054 } 4055 Type tmpBound = Si.bound.hasTag(UNDETVAR) ? ((UndetVar)Si.bound).qtype : Si.bound; 4056 Type tmpLower = Si.lower.hasTag(UNDETVAR) ? ((UndetVar)Si.lower).qtype : Si.lower; 4057 if (!Si.bound.hasTag(ERROR) && 4058 !Si.lower.hasTag(ERROR) && 4059 isSameType(tmpBound, tmpLower, false)) { 4060 currentS.head = Si.bound; 4061 } 4062 } 4063 currentA = currentA.tail; 4064 currentT = currentT.tail; 4065 currentS = currentS.tail; 4066 } 4067 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty()) 4068 return erasure(t); // some "rare" type involved 4069 4070 if (captured) 4071 return new ClassType(cls.getEnclosingType(), S, cls.tsym, 4072 cls.getMetadata()); 4073 else 4074 return t; 4075 } 4076 // where 4077 public List<Type> freshTypeVariables(List<Type> types) { 4078 ListBuffer<Type> result = new ListBuffer<>(); 4079 for (Type t : types) { 4080 if (t.hasTag(WILDCARD)) { 4081 Type bound = ((WildcardType)t).getExtendsBound(); 4082 if (bound == null) 4083 bound = syms.objectType; 4084 result.append(new CapturedType(capturedName, 4085 syms.noSymbol, 4086 bound, 4087 syms.botType, 4088 (WildcardType)t)); 4089 } else { 4090 result.append(t); 4091 } 4092 } 4093 return result.toList(); 4094 } 4095 // </editor-fold> 4096 4097 // <editor-fold defaultstate="collapsed" desc="Internal utility methods"> 4098 private boolean sideCast(Type from, Type to, Warner warn) { 4099 // We are casting from type $from$ to type $to$, which are 4100 // non-final unrelated types. This method 4101 // tries to reject a cast by transferring type parameters 4102 // from $to$ to $from$ by common superinterfaces. 4103 boolean reverse = false; 4104 Type target = to; 4105 if ((to.tsym.flags() & INTERFACE) == 0) { 4106 Assert.check((from.tsym.flags() & INTERFACE) != 0); 4107 reverse = true; 4108 to = from; 4109 from = target; 4110 } 4111 List<Type> commonSupers = superClosure(to, erasure(from)); 4112 boolean giveWarning = commonSupers.isEmpty(); 4113 // The arguments to the supers could be unified here to 4114 // get a more accurate analysis 4115 while (commonSupers.nonEmpty()) { 4116 Type t1 = asSuper(from, commonSupers.head.tsym); 4117 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym); 4118 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) 4119 return false; 4120 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)); 4121 commonSupers = commonSupers.tail; 4122 } 4123 if (giveWarning && !isReifiable(reverse ? from : to)) 4124 warn.warn(LintCategory.UNCHECKED); 4125 return true; 4126 } 4127 4128 private boolean sideCastFinal(Type from, Type to, Warner warn) { 4129 // We are casting from type $from$ to type $to$, which are 4130 // unrelated types one of which is final and the other of 4131 // which is an interface. This method 4132 // tries to reject a cast by transferring type parameters 4133 // from the final class to the interface. 4134 boolean reverse = false; 4135 Type target = to; 4136 if ((to.tsym.flags() & INTERFACE) == 0) { 4137 Assert.check((from.tsym.flags() & INTERFACE) != 0); 4138 reverse = true; 4139 to = from; 4140 from = target; 4141 } 4142 Assert.check((from.tsym.flags() & FINAL) != 0); 4143 Type t1 = asSuper(from, to.tsym); 4144 if (t1 == null) return false; 4145 Type t2 = to; 4146 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) 4147 return false; 4148 if (!isReifiable(target) && 4149 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2))) 4150 warn.warn(LintCategory.UNCHECKED); 4151 return true; 4152 } 4153 4154 private boolean giveWarning(Type from, Type to) { 4155 List<Type> bounds = to.isCompound() ? 4156 directSupertypes(to) : List.of(to); 4157 for (Type b : bounds) { 4158 Type subFrom = asSub(from, b.tsym); 4159 if (b.isParameterized() && 4160 (!(isUnbounded(b) || 4161 isSubtype(from, b) || 4162 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) { 4163 return true; 4164 } 4165 } 4166 return false; 4167 } 4168 4169 private List<Type> superClosure(Type t, Type s) { 4170 List<Type> cl = List.nil(); 4171 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { 4172 if (isSubtype(s, erasure(l.head))) { 4173 cl = insert(cl, l.head); 4174 } else { 4175 cl = union(cl, superClosure(l.head, s)); 4176 } 4177 } 4178 return cl; 4179 } 4180 4181 private boolean containsTypeEquivalent(Type t, Type s) { 4182 return isSameType(t, s) || // shortcut 4183 containsType(t, s) && containsType(s, t); 4184 } 4185 4186 // <editor-fold defaultstate="collapsed" desc="adapt"> 4187 /** 4188 * Adapt a type by computing a substitution which maps a source 4189 * type to a target type. 4190 * 4191 * @param source the source type 4192 * @param target the target type 4193 * @param from the type variables of the computed substitution 4194 * @param to the types of the computed substitution. 4195 */ 4196 public void adapt(Type source, 4197 Type target, 4198 ListBuffer<Type> from, 4199 ListBuffer<Type> to) throws AdaptFailure { 4200 new Adapter(from, to).adapt(source, target); 4201 } 4202 4203 class Adapter extends SimpleVisitor<Void, Type> { 4204 4205 ListBuffer<Type> from; 4206 ListBuffer<Type> to; 4207 Map<Symbol,Type> mapping; 4208 4209 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) { 4210 this.from = from; 4211 this.to = to; 4212 mapping = new HashMap<>(); 4213 } 4214 4215 public void adapt(Type source, Type target) throws AdaptFailure { 4216 visit(source, target); 4217 List<Type> fromList = from.toList(); 4218 List<Type> toList = to.toList(); 4219 while (!fromList.isEmpty()) { 4220 Type val = mapping.get(fromList.head.tsym); 4221 if (toList.head != val) 4222 toList.head = val; 4223 fromList = fromList.tail; 4224 toList = toList.tail; 4225 } 4226 } 4227 4228 @Override 4229 public Void visitClassType(ClassType source, Type target) throws AdaptFailure { 4230 if (target.hasTag(CLASS)) 4231 adaptRecursive(source.allparams(), target.allparams()); 4232 return null; 4233 } 4234 4235 @Override 4236 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure { 4237 if (target.hasTag(ARRAY)) 4238 adaptRecursive(elemtype(source), elemtype(target)); 4239 return null; 4240 } 4241 4242 @Override 4243 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure { 4244 if (source.isExtendsBound()) 4245 adaptRecursive(wildUpperBound(source), wildUpperBound(target)); 4246 else if (source.isSuperBound()) 4247 adaptRecursive(wildLowerBound(source), wildLowerBound(target)); 4248 return null; 4249 } 4250 4251 @Override 4252 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure { 4253 // Check to see if there is 4254 // already a mapping for $source$, in which case 4255 // the old mapping will be merged with the new 4256 Type val = mapping.get(source.tsym); 4257 if (val != null) { 4258 if (val.isSuperBound() && target.isSuperBound()) { 4259 val = isSubtype(wildLowerBound(val), wildLowerBound(target)) 4260 ? target : val; 4261 } else if (val.isExtendsBound() && target.isExtendsBound()) { 4262 val = isSubtype(wildUpperBound(val), wildUpperBound(target)) 4263 ? val : target; 4264 } else if (!isSameType(val, target)) { 4265 throw new AdaptFailure(); 4266 } 4267 } else { 4268 val = target; 4269 from.append(source); 4270 to.append(target); 4271 } 4272 mapping.put(source.tsym, val); 4273 return null; 4274 } 4275 4276 @Override 4277 public Void visitType(Type source, Type target) { 4278 return null; 4279 } 4280 4281 private Set<TypePair> cache = new HashSet<>(); 4282 4283 private void adaptRecursive(Type source, Type target) { 4284 TypePair pair = new TypePair(source, target); 4285 if (cache.add(pair)) { 4286 try { 4287 visit(source, target); 4288 } finally { 4289 cache.remove(pair); 4290 } 4291 } 4292 } 4293 4294 private void adaptRecursive(List<Type> source, List<Type> target) { 4295 if (source.length() == target.length()) { 4296 while (source.nonEmpty()) { 4297 adaptRecursive(source.head, target.head); 4298 source = source.tail; 4299 target = target.tail; 4300 } 4301 } 4302 } 4303 } 4304 4305 public static class AdaptFailure extends RuntimeException { 4306 static final long serialVersionUID = -7490231548272701566L; 4307 } 4308 4309 private void adaptSelf(Type t, 4310 ListBuffer<Type> from, 4311 ListBuffer<Type> to) { 4312 try { 4313 //if (t.tsym.type != t) 4314 adapt(t.tsym.type, t, from, to); 4315 } catch (AdaptFailure ex) { 4316 // Adapt should never fail calculating a mapping from 4317 // t.tsym.type to t as there can be no merge problem. 4318 throw new AssertionError(ex); 4319 } 4320 } 4321 // </editor-fold> 4322 4323 /** 4324 * Rewrite all type variables (universal quantifiers) in the given 4325 * type to wildcards (existential quantifiers). This is used to 4326 * determine if a cast is allowed. For example, if high is true 4327 * and {@code T <: Number}, then {@code List<T>} is rewritten to 4328 * {@code List<? extends Number>}. Since {@code List<Integer> <: 4329 * List<? extends Number>} a {@code List<T>} can be cast to {@code 4330 * List<Integer>} with a warning. 4331 * @param t a type 4332 * @param high if true return an upper bound; otherwise a lower 4333 * bound 4334 * @param rewriteTypeVars only rewrite captured wildcards if false; 4335 * otherwise rewrite all type variables 4336 * @return the type rewritten with wildcards (existential 4337 * quantifiers) only 4338 */ 4339 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) { 4340 return new Rewriter(high, rewriteTypeVars).visit(t); 4341 } 4342 4343 class Rewriter extends UnaryVisitor<Type> { 4344 4345 boolean high; 4346 boolean rewriteTypeVars; 4347 4348 Rewriter(boolean high, boolean rewriteTypeVars) { 4349 this.high = high; 4350 this.rewriteTypeVars = rewriteTypeVars; 4351 } 4352 4353 @Override 4354 public Type visitClassType(ClassType t, Void s) { 4355 ListBuffer<Type> rewritten = new ListBuffer<>(); 4356 boolean changed = false; 4357 for (Type arg : t.allparams()) { 4358 Type bound = visit(arg); 4359 if (arg != bound) { 4360 changed = true; 4361 } 4362 rewritten.append(bound); 4363 } 4364 if (changed) 4365 return subst(t.tsym.type, 4366 t.tsym.type.allparams(), 4367 rewritten.toList()); 4368 else 4369 return t; 4370 } 4371 4372 public Type visitType(Type t, Void s) { 4373 return t; 4374 } 4375 4376 @Override 4377 public Type visitCapturedType(CapturedType t, Void s) { 4378 Type w_bound = t.wildcard.type; 4379 Type bound = w_bound.contains(t) ? 4380 erasure(w_bound) : 4381 visit(w_bound); 4382 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind); 4383 } 4384 4385 @Override 4386 public Type visitTypeVar(TypeVar t, Void s) { 4387 if (rewriteTypeVars) { 4388 Type bound = t.bound.contains(t) ? 4389 erasure(t.bound) : 4390 visit(t.bound); 4391 return rewriteAsWildcardType(bound, t, EXTENDS); 4392 } else { 4393 return t; 4394 } 4395 } 4396 4397 @Override 4398 public Type visitWildcardType(WildcardType t, Void s) { 4399 Type bound2 = visit(t.type); 4400 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind); 4401 } 4402 4403 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) { 4404 switch (bk) { 4405 case EXTENDS: return high ? 4406 makeExtendsWildcard(B(bound), formal) : 4407 makeExtendsWildcard(syms.objectType, formal); 4408 case SUPER: return high ? 4409 makeSuperWildcard(syms.botType, formal) : 4410 makeSuperWildcard(B(bound), formal); 4411 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal); 4412 default: 4413 Assert.error("Invalid bound kind " + bk); 4414 return null; 4415 } 4416 } 4417 4418 Type B(Type t) { 4419 while (t.hasTag(WILDCARD)) { 4420 WildcardType w = (WildcardType)t; 4421 t = high ? 4422 w.getExtendsBound() : 4423 w.getSuperBound(); 4424 if (t == null) { 4425 t = high ? syms.objectType : syms.botType; 4426 } 4427 } 4428 return t; 4429 } 4430 } 4431 4432 4433 /** 4434 * Create a wildcard with the given upper (extends) bound; create 4435 * an unbounded wildcard if bound is Object. 4436 * 4437 * @param bound the upper bound 4438 * @param formal the formal type parameter that will be 4439 * substituted by the wildcard 4440 */ 4441 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) { 4442 if (bound == syms.objectType) { 4443 return new WildcardType(syms.objectType, 4444 BoundKind.UNBOUND, 4445 syms.boundClass, 4446 formal); 4447 } else { 4448 return new WildcardType(bound, 4449 BoundKind.EXTENDS, 4450 syms.boundClass, 4451 formal); 4452 } 4453 } 4454 4455 /** 4456 * Create a wildcard with the given lower (super) bound; create an 4457 * unbounded wildcard if bound is bottom (type of {@code null}). 4458 * 4459 * @param bound the lower bound 4460 * @param formal the formal type parameter that will be 4461 * substituted by the wildcard 4462 */ 4463 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) { 4464 if (bound.hasTag(BOT)) { 4465 return new WildcardType(syms.objectType, 4466 BoundKind.UNBOUND, 4467 syms.boundClass, 4468 formal); 4469 } else { 4470 return new WildcardType(bound, 4471 BoundKind.SUPER, 4472 syms.boundClass, 4473 formal); 4474 } 4475 } 4476 4477 /** 4478 * A wrapper for a type that allows use in sets. 4479 */ 4480 public static class UniqueType { 4481 public final Type type; 4482 final Types types; 4483 4484 public UniqueType(Type type, Types types) { 4485 this.type = type; 4486 this.types = types; 4487 } 4488 4489 public int hashCode() { 4490 return types.hashCode(type); 4491 } 4492 4493 public boolean equals(Object obj) { 4494 return (obj instanceof UniqueType) && 4495 types.isSameType(type, ((UniqueType)obj).type); 4496 } 4497 4498 public String toString() { 4499 return type.toString(); 4500 } 4501 4502 } 4503 // </editor-fold> 4504 4505 // <editor-fold defaultstate="collapsed" desc="Visitors"> 4506 /** 4507 * A default visitor for types. All visitor methods except 4508 * visitType are implemented by delegating to visitType. Concrete 4509 * subclasses must provide an implementation of visitType and can 4510 * override other methods as needed. 4511 * 4512 * @param <R> the return type of the operation implemented by this 4513 * visitor; use Void if no return type is needed. 4514 * @param <S> the type of the second argument (the first being the 4515 * type itself) of the operation implemented by this visitor; use 4516 * Void if a second argument is not needed. 4517 */ 4518 public static abstract class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> { 4519 final public R visit(Type t, S s) { return t.accept(this, s); } 4520 public R visitClassType(ClassType t, S s) { return visitType(t, s); } 4521 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); } 4522 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); } 4523 public R visitMethodType(MethodType t, S s) { return visitType(t, s); } 4524 public R visitPackageType(PackageType t, S s) { return visitType(t, s); } 4525 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); } 4526 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); } 4527 public R visitForAll(ForAll t, S s) { return visitType(t, s); } 4528 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); } 4529 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); } 4530 } 4531 4532 /** 4533 * A default visitor for symbols. All visitor methods except 4534 * visitSymbol are implemented by delegating to visitSymbol. Concrete 4535 * subclasses must provide an implementation of visitSymbol and can 4536 * override other methods as needed. 4537 * 4538 * @param <R> the return type of the operation implemented by this 4539 * visitor; use Void if no return type is needed. 4540 * @param <S> the type of the second argument (the first being the 4541 * symbol itself) of the operation implemented by this visitor; use 4542 * Void if a second argument is not needed. 4543 */ 4544 public static abstract class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> { 4545 final public R visit(Symbol s, S arg) { return s.accept(this, arg); } 4546 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); } 4547 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); } 4548 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); } 4549 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); } 4550 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); } 4551 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); } 4552 } 4553 4554 /** 4555 * A <em>simple</em> visitor for types. This visitor is simple as 4556 * captured wildcards, for-all types (generic methods), and 4557 * undetermined type variables (part of inference) are hidden. 4558 * Captured wildcards are hidden by treating them as type 4559 * variables and the rest are hidden by visiting their qtypes. 4560 * 4561 * @param <R> the return type of the operation implemented by this 4562 * visitor; use Void if no return type is needed. 4563 * @param <S> the type of the second argument (the first being the 4564 * type itself) of the operation implemented by this visitor; use 4565 * Void if a second argument is not needed. 4566 */ 4567 public static abstract class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> { 4568 @Override 4569 public R visitCapturedType(CapturedType t, S s) { 4570 return visitTypeVar(t, s); 4571 } 4572 @Override 4573 public R visitForAll(ForAll t, S s) { 4574 return visit(t.qtype, s); 4575 } 4576 @Override 4577 public R visitUndetVar(UndetVar t, S s) { 4578 return visit(t.qtype, s); 4579 } 4580 } 4581 4582 /** 4583 * A plain relation on types. That is a 2-ary function on the 4584 * form Type × Type → Boolean. 4585 * <!-- In plain text: Type x Type -> Boolean --> 4586 */ 4587 public static abstract class TypeRelation extends SimpleVisitor<Boolean,Type> {} 4588 4589 /** 4590 * A convenience visitor for implementing operations that only 4591 * require one argument (the type itself), that is, unary 4592 * operations. 4593 * 4594 * @param <R> the return type of the operation implemented by this 4595 * visitor; use Void if no return type is needed. 4596 */ 4597 public static abstract class UnaryVisitor<R> extends SimpleVisitor<R,Void> { 4598 final public R visit(Type t) { return t.accept(this, null); } 4599 } 4600 4601 /** 4602 * A visitor for implementing a mapping from types to types. The 4603 * default behavior of this class is to implement the identity 4604 * mapping (mapping a type to itself). This can be overridden in 4605 * subclasses. 4606 * 4607 * @param <S> the type of the second argument (the first being the 4608 * type itself) of this mapping; use Void if a second argument is 4609 * not needed. 4610 */ 4611 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> { 4612 final public Type visit(Type t) { return t.accept(this, null); } 4613 public Type visitType(Type t, S s) { return t; } 4614 } 4615 // </editor-fold> 4616 4617 4618 // <editor-fold defaultstate="collapsed" desc="Annotation support"> 4619 4620 public RetentionPolicy getRetention(Attribute.Compound a) { 4621 return getRetention(a.type.tsym); 4622 } 4623 4624 public RetentionPolicy getRetention(TypeSymbol sym) { 4625 RetentionPolicy vis = RetentionPolicy.CLASS; // the default 4626 Attribute.Compound c = sym.attribute(syms.retentionType.tsym); 4627 if (c != null) { 4628 Attribute value = c.member(names.value); 4629 if (value != null && value instanceof Attribute.Enum) { 4630 Name levelName = ((Attribute.Enum)value).value.name; 4631 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE; 4632 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS; 4633 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME; 4634 else ;// /* fail soft */ throw new AssertionError(levelName); 4635 } 4636 } 4637 return vis; 4638 } 4639 // </editor-fold> 4640 4641 // <editor-fold defaultstate="collapsed" desc="Signature Generation"> 4642 4643 public static abstract class SignatureGenerator { 4644 4645 private final Types types; 4646 4647 protected abstract void append(char ch); 4648 protected abstract void append(byte[] ba); 4649 protected abstract void append(Name name); 4650 protected void classReference(ClassSymbol c) { /* by default: no-op */ } 4651 4652 protected SignatureGenerator(Types types) { 4653 this.types = types; 4654 } 4655 4656 /** 4657 * Assemble signature of given type in string buffer. 4658 */ 4659 public void assembleSig(Type type) { 4660 switch (type.getTag()) { 4661 case BYTE: 4662 append('B'); 4663 break; 4664 case SHORT: 4665 append('S'); 4666 break; 4667 case CHAR: 4668 append('C'); 4669 break; 4670 case INT: 4671 append('I'); 4672 break; 4673 case LONG: 4674 append('J'); 4675 break; 4676 case FLOAT: 4677 append('F'); 4678 break; 4679 case DOUBLE: 4680 append('D'); 4681 break; 4682 case BOOLEAN: 4683 append('Z'); 4684 break; 4685 case VOID: 4686 append('V'); 4687 break; 4688 case CLASS: 4689 append('L'); 4690 assembleClassSig(type); 4691 append(';'); 4692 break; 4693 case ARRAY: 4694 ArrayType at = (ArrayType) type; 4695 append('['); 4696 assembleSig(at.elemtype); 4697 break; 4698 case METHOD: 4699 MethodType mt = (MethodType) type; 4700 append('('); 4701 assembleSig(mt.argtypes); 4702 append(')'); 4703 assembleSig(mt.restype); 4704 if (hasTypeVar(mt.thrown)) { 4705 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) { 4706 append('^'); 4707 assembleSig(l.head); 4708 } 4709 } 4710 break; 4711 case WILDCARD: { 4712 Type.WildcardType ta = (Type.WildcardType) type; 4713 switch (ta.kind) { 4714 case SUPER: 4715 append('-'); 4716 assembleSig(ta.type); 4717 break; 4718 case EXTENDS: 4719 append('+'); 4720 assembleSig(ta.type); 4721 break; 4722 case UNBOUND: 4723 append('*'); 4724 break; 4725 default: 4726 throw new AssertionError(ta.kind); 4727 } 4728 break; 4729 } 4730 case TYPEVAR: 4731 append('T'); 4732 append(type.tsym.name); 4733 append(';'); 4734 break; 4735 case FORALL: 4736 Type.ForAll ft = (Type.ForAll) type; 4737 assembleParamsSig(ft.tvars); 4738 assembleSig(ft.qtype); 4739 break; 4740 default: 4741 throw new AssertionError("typeSig " + type.getTag()); 4742 } 4743 } 4744 4745 public boolean hasTypeVar(List<Type> l) { 4746 while (l.nonEmpty()) { 4747 if (l.head.hasTag(TypeTag.TYPEVAR)) { 4748 return true; 4749 } 4750 l = l.tail; 4751 } 4752 return false; 4753 } 4754 4755 public void assembleClassSig(Type type) { 4756 ClassType ct = (ClassType) type; 4757 ClassSymbol c = (ClassSymbol) ct.tsym; 4758 classReference(c); 4759 Type outer = ct.getEnclosingType(); 4760 if (outer.allparams().nonEmpty()) { 4761 boolean rawOuter = 4762 c.owner.kind == MTH || // either a local class 4763 c.name == types.names.empty; // or anonymous 4764 assembleClassSig(rawOuter 4765 ? types.erasure(outer) 4766 : outer); 4767 append(rawOuter ? '$' : '.'); 4768 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname)); 4769 append(rawOuter 4770 ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength()) 4771 : c.name); 4772 } else { 4773 append(externalize(c.flatname)); 4774 } 4775 if (ct.getTypeArguments().nonEmpty()) { 4776 append('<'); 4777 assembleSig(ct.getTypeArguments()); 4778 append('>'); 4779 } 4780 } 4781 4782 public void assembleParamsSig(List<Type> typarams) { 4783 append('<'); 4784 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) { 4785 Type.TypeVar tvar = (Type.TypeVar) ts.head; 4786 append(tvar.tsym.name); 4787 List<Type> bounds = types.getBounds(tvar); 4788 if ((bounds.head.tsym.flags() & INTERFACE) != 0) { 4789 append(':'); 4790 } 4791 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) { 4792 append(':'); 4793 assembleSig(l.head); 4794 } 4795 } 4796 append('>'); 4797 } 4798 4799 private void assembleSig(List<Type> types) { 4800 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) { 4801 assembleSig(ts.head); 4802 } 4803 } 4804 } 4805 // </editor-fold> 4806 4807 public void newRound() { 4808 descCache._map.clear(); 4809 isDerivedRawCache.clear(); 4810 implCache._map.clear(); 4811 membersCache._map.clear(); 4812 closureCache.clear(); 4813 } 4814} 4815