Types.java revision 2838:218d589184d3
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; 35 36import javax.tools.JavaFileObject; 37 38import com.sun.tools.javac.code.Attribute.RetentionPolicy; 39import com.sun.tools.javac.code.Lint.LintCategory; 40import com.sun.tools.javac.code.Type.UndetVar.InferenceBound; 41import com.sun.tools.javac.comp.AttrContext; 42import com.sun.tools.javac.comp.Check; 43import com.sun.tools.javac.comp.Enter; 44import com.sun.tools.javac.comp.Env; 45import com.sun.tools.javac.util.*; 46 47import static com.sun.tools.javac.code.BoundKind.*; 48import static com.sun.tools.javac.code.Flags.*; 49import static com.sun.tools.javac.code.Kinds.Kind.*; 50import static com.sun.tools.javac.code.Scope.*; 51import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE; 52import static com.sun.tools.javac.code.Symbol.*; 53import static com.sun.tools.javac.code.Type.*; 54import static com.sun.tools.javac.code.TypeTag.*; 55import static com.sun.tools.javac.jvm.ClassFile.externalize; 56 57/** 58 * Utility class containing various operations on types. 59 * 60 * <p>Unless other names are more illustrative, the following naming 61 * conventions should be observed in this file: 62 * 63 * <dl> 64 * <dt>t</dt> 65 * <dd>If the first argument to an operation is a type, it should be named t.</dd> 66 * <dt>s</dt> 67 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd> 68 * <dt>ts</dt> 69 * <dd>If an operations takes a list of types, the first should be named ts.</dd> 70 * <dt>ss</dt> 71 * <dd>A second list of types should be named ss.</dd> 72 * </dl> 73 * 74 * <p><b>This is NOT part of any supported API. 75 * If you write code that depends on this, you do so at your own risk. 76 * This code and its internal interfaces are subject to change or 77 * deletion without notice.</b> 78 */ 79public class Types { 80 protected static final Context.Key<Types> typesKey = new Context.Key<>(); 81 82 final Symtab syms; 83 final JavacMessages messages; 84 final Names names; 85 final boolean allowObjectToPrimitiveCast; 86 final boolean allowDefaultMethods; 87 final Check chk; 88 final Enter enter; 89 JCDiagnostic.Factory diags; 90 List<Warner> warnStack = List.nil(); 91 final Name capturedName; 92 private final FunctionDescriptorLookupError functionDescriptorLookupError; 93 94 public final Warner noWarnings; 95 96 // <editor-fold defaultstate="collapsed" desc="Instantiating"> 97 public static Types instance(Context context) { 98 Types instance = context.get(typesKey); 99 if (instance == null) 100 instance = new Types(context); 101 return instance; 102 } 103 104 protected Types(Context context) { 105 context.put(typesKey, this); 106 syms = Symtab.instance(context); 107 names = Names.instance(context); 108 Source source = Source.instance(context); 109 allowObjectToPrimitiveCast = source.allowObjectToPrimitiveCast(); 110 allowDefaultMethods = source.allowDefaultMethods(); 111 chk = Check.instance(context); 112 enter = Enter.instance(context); 113 capturedName = names.fromString("<captured wildcard>"); 114 messages = JavacMessages.instance(context); 115 diags = JCDiagnostic.Factory.instance(context); 116 functionDescriptorLookupError = new FunctionDescriptorLookupError(); 117 noWarnings = new Warner(null); 118 } 119 // </editor-fold> 120 121 // <editor-fold defaultstate="collapsed" desc="bounds"> 122 /** 123 * Get a wildcard's upper bound, returning non-wildcards unchanged. 124 * @param t a type argument, either a wildcard or a type 125 */ 126 public Type wildUpperBound(Type t) { 127 if (t.hasTag(WILDCARD)) { 128 WildcardType w = (WildcardType) t; 129 if (w.isSuperBound()) 130 return w.bound == null ? syms.objectType : w.bound.bound; 131 else 132 return wildUpperBound(w.type); 133 } 134 else return t; 135 } 136 137 /** 138 * Get a capture variable's upper bound, returning other types unchanged. 139 * @param t a type 140 */ 141 public Type cvarUpperBound(Type t) { 142 if (t.hasTag(TYPEVAR)) { 143 TypeVar v = (TypeVar) t; 144 return v.isCaptured() ? cvarUpperBound(v.bound) : v; 145 } 146 else return t; 147 } 148 149 /** 150 * Get a wildcard's lower bound, returning non-wildcards unchanged. 151 * @param t a type argument, either a wildcard or a type 152 */ 153 public Type wildLowerBound(Type t) { 154 if (t.hasTag(WILDCARD)) { 155 WildcardType w = (WildcardType) t; 156 return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type); 157 } 158 else return t; 159 } 160 161 /** 162 * Get a capture variable's lower bound, returning other types unchanged. 163 * @param t a type 164 */ 165 public Type cvarLowerBound(Type t) { 166 if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) { 167 return cvarLowerBound(t.getLowerBound()); 168 } 169 else return t; 170 } 171 172 /** 173 * Recursively skip type-variables until a class/array type is found; capture conversion is then 174 * (optionally) applied to the resulting type. This is useful for i.e. computing a site that is 175 * suitable for a method lookup. 176 */ 177 public Type skipTypeVars(Type site, boolean capture) { 178 while (site.hasTag(TYPEVAR)) { 179 site = site.getUpperBound(); 180 } 181 return capture ? capture(site) : site; 182 } 183 // </editor-fold> 184 185 // <editor-fold defaultstate="collapsed" desc="isUnbounded"> 186 /** 187 * Checks that all the arguments to a class are unbounded 188 * wildcards or something else that doesn't make any restrictions 189 * on the arguments. If a class isUnbounded, a raw super- or 190 * subclass can be cast to it without a warning. 191 * @param t a type 192 * @return true iff the given type is unbounded or raw 193 */ 194 public boolean isUnbounded(Type t) { 195 return isUnbounded.visit(t); 196 } 197 // where 198 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() { 199 200 public Boolean visitType(Type t, Void ignored) { 201 return true; 202 } 203 204 @Override 205 public Boolean visitClassType(ClassType t, Void ignored) { 206 List<Type> parms = t.tsym.type.allparams(); 207 List<Type> args = t.allparams(); 208 while (parms.nonEmpty()) { 209 WildcardType unb = new WildcardType(syms.objectType, 210 BoundKind.UNBOUND, 211 syms.boundClass, 212 (TypeVar)parms.head); 213 if (!containsType(args.head, unb)) 214 return false; 215 parms = parms.tail; 216 args = args.tail; 217 } 218 return true; 219 } 220 }; 221 // </editor-fold> 222 223 // <editor-fold defaultstate="collapsed" desc="asSub"> 224 /** 225 * Return the least specific subtype of t that starts with symbol 226 * sym. If none exists, return null. The least specific subtype 227 * is determined as follows: 228 * 229 * <p>If there is exactly one parameterized instance of sym that is a 230 * subtype of t, that parameterized instance is returned.<br> 231 * Otherwise, if the plain type or raw type `sym' is a subtype of 232 * type t, the type `sym' itself is returned. Otherwise, null is 233 * returned. 234 */ 235 public Type asSub(Type t, Symbol sym) { 236 return asSub.visit(t, sym); 237 } 238 // where 239 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() { 240 241 public Type visitType(Type t, Symbol sym) { 242 return null; 243 } 244 245 @Override 246 public Type visitClassType(ClassType t, Symbol sym) { 247 if (t.tsym == sym) 248 return t; 249 Type base = asSuper(sym.type, t.tsym); 250 if (base == null) 251 return null; 252 ListBuffer<Type> from = new ListBuffer<>(); 253 ListBuffer<Type> to = new ListBuffer<>(); 254 try { 255 adapt(base, t, from, to); 256 } catch (AdaptFailure ex) { 257 return null; 258 } 259 Type res = subst(sym.type, from.toList(), to.toList()); 260 if (!isSubtype(res, t)) 261 return null; 262 ListBuffer<Type> openVars = new ListBuffer<>(); 263 for (List<Type> l = sym.type.allparams(); 264 l.nonEmpty(); l = l.tail) 265 if (res.contains(l.head) && !t.contains(l.head)) 266 openVars.append(l.head); 267 if (openVars.nonEmpty()) { 268 if (t.isRaw()) { 269 // The subtype of a raw type is raw 270 res = erasure(res); 271 } else { 272 // Unbound type arguments default to ? 273 List<Type> opens = openVars.toList(); 274 ListBuffer<Type> qs = new ListBuffer<>(); 275 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) { 276 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, 277 syms.boundClass, (TypeVar) iter.head)); 278 } 279 res = subst(res, opens, qs.toList()); 280 } 281 } 282 return res; 283 } 284 285 @Override 286 public Type visitErrorType(ErrorType t, Symbol sym) { 287 return t; 288 } 289 }; 290 // </editor-fold> 291 292 // <editor-fold defaultstate="collapsed" desc="isConvertible"> 293 /** 294 * Is t a subtype of or convertible via boxing/unboxing 295 * conversion to s? 296 */ 297 public boolean isConvertible(Type t, Type s, Warner warn) { 298 if (t.hasTag(ERROR)) { 299 return true; 300 } 301 boolean tPrimitive = t.isPrimitive(); 302 boolean sPrimitive = s.isPrimitive(); 303 if (tPrimitive == sPrimitive) { 304 return isSubtypeUnchecked(t, s, warn); 305 } 306 return tPrimitive 307 ? isSubtype(boxedClass(t).type, s) 308 : isSubtype(unboxedType(t), s); 309 } 310 311 /** 312 * Is t a subtype of or convertible via boxing/unboxing 313 * conversions to s? 314 */ 315 public boolean isConvertible(Type t, Type s) { 316 return isConvertible(t, s, noWarnings); 317 } 318 // </editor-fold> 319 320 // <editor-fold defaultstate="collapsed" desc="findSam"> 321 322 /** 323 * Exception used to report a function descriptor lookup failure. The exception 324 * wraps a diagnostic that can be used to generate more details error 325 * messages. 326 */ 327 public static class FunctionDescriptorLookupError extends RuntimeException { 328 private static final long serialVersionUID = 0; 329 330 JCDiagnostic diagnostic; 331 332 FunctionDescriptorLookupError() { 333 this.diagnostic = null; 334 } 335 336 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) { 337 this.diagnostic = diag; 338 return this; 339 } 340 341 public JCDiagnostic getDiagnostic() { 342 return diagnostic; 343 } 344 } 345 346 /** 347 * A cache that keeps track of function descriptors associated with given 348 * functional interfaces. 349 */ 350 class DescriptorCache { 351 352 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>(); 353 354 class FunctionDescriptor { 355 Symbol descSym; 356 357 FunctionDescriptor(Symbol descSym) { 358 this.descSym = descSym; 359 } 360 361 public Symbol getSymbol() { 362 return descSym; 363 } 364 365 public Type getType(Type site) { 366 site = removeWildcards(site); 367 if (!chk.checkValidGenericType(site)) { 368 //if the inferred functional interface type is not well-formed, 369 //or if it's not a subtype of the original target, issue an error 370 throw failure(diags.fragment("no.suitable.functional.intf.inst", site)); 371 } 372 return memberType(site, descSym); 373 } 374 } 375 376 class Entry { 377 final FunctionDescriptor cachedDescRes; 378 final int prevMark; 379 380 public Entry(FunctionDescriptor cachedDescRes, 381 int prevMark) { 382 this.cachedDescRes = cachedDescRes; 383 this.prevMark = prevMark; 384 } 385 386 boolean matches(int mark) { 387 return this.prevMark == mark; 388 } 389 } 390 391 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError { 392 Entry e = _map.get(origin); 393 CompoundScope members = membersClosure(origin.type, false); 394 if (e == null || 395 !e.matches(members.getMark())) { 396 FunctionDescriptor descRes = findDescriptorInternal(origin, members); 397 _map.put(origin, new Entry(descRes, members.getMark())); 398 return descRes; 399 } 400 else { 401 return e.cachedDescRes; 402 } 403 } 404 405 /** 406 * Compute the function descriptor associated with a given functional interface 407 */ 408 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin, 409 CompoundScope membersCache) throws FunctionDescriptorLookupError { 410 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0) { 411 //t must be an interface 412 throw failure("not.a.functional.intf", origin); 413 } 414 415 final ListBuffer<Symbol> abstracts = new ListBuffer<>(); 416 for (Symbol sym : membersCache.getSymbols(new DescriptorFilter(origin))) { 417 Type mtype = memberType(origin.type, sym); 418 if (abstracts.isEmpty() || 419 (sym.name == abstracts.first().name && 420 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) { 421 abstracts.append(sym); 422 } else { 423 //the target method(s) should be the only abstract members of t 424 throw failure("not.a.functional.intf.1", origin, 425 diags.fragment("incompatible.abstracts", Kinds.kindName(origin), origin)); 426 } 427 } 428 if (abstracts.isEmpty()) { 429 //t must define a suitable non-generic method 430 throw failure("not.a.functional.intf.1", origin, 431 diags.fragment("no.abstracts", Kinds.kindName(origin), origin)); 432 } else if (abstracts.size() == 1) { 433 return new FunctionDescriptor(abstracts.first()); 434 } else { // size > 1 435 FunctionDescriptor descRes = mergeDescriptors(origin, abstracts.toList()); 436 if (descRes == null) { 437 //we can get here if the functional interface is ill-formed 438 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>(); 439 for (Symbol desc : abstracts) { 440 String key = desc.type.getThrownTypes().nonEmpty() ? 441 "descriptor.throws" : "descriptor"; 442 descriptors.append(diags.fragment(key, desc.name, 443 desc.type.getParameterTypes(), 444 desc.type.getReturnType(), 445 desc.type.getThrownTypes())); 446 } 447 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors = 448 new JCDiagnostic.MultilineDiagnostic(diags.fragment("incompatible.descs.in.functional.intf", 449 Kinds.kindName(origin), origin), descriptors.toList()); 450 throw failure(incompatibleDescriptors); 451 } 452 return descRes; 453 } 454 } 455 456 /** 457 * Compute a synthetic type for the target descriptor given a list 458 * of override-equivalent methods in the functional interface type. 459 * The resulting method type is a method type that is override-equivalent 460 * and return-type substitutable with each method in the original list. 461 */ 462 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) { 463 //pick argument types - simply take the signature that is a 464 //subsignature of all other signatures in the list (as per JLS 8.4.2) 465 List<Symbol> mostSpecific = List.nil(); 466 outer: for (Symbol msym1 : methodSyms) { 467 Type mt1 = memberType(origin.type, msym1); 468 for (Symbol msym2 : methodSyms) { 469 Type mt2 = memberType(origin.type, msym2); 470 if (!isSubSignature(mt1, mt2)) { 471 continue outer; 472 } 473 } 474 mostSpecific = mostSpecific.prepend(msym1); 475 } 476 if (mostSpecific.isEmpty()) { 477 return null; 478 } 479 480 481 //pick return types - this is done in two phases: (i) first, the most 482 //specific return type is chosen using strict subtyping; if this fails, 483 //a second attempt is made using return type substitutability (see JLS 8.4.5) 484 boolean phase2 = false; 485 Symbol bestSoFar = null; 486 while (bestSoFar == null) { 487 outer: for (Symbol msym1 : mostSpecific) { 488 Type mt1 = memberType(origin.type, msym1); 489 for (Symbol msym2 : methodSyms) { 490 Type mt2 = memberType(origin.type, msym2); 491 if (phase2 ? 492 !returnTypeSubstitutable(mt1, mt2) : 493 !isSubtypeInternal(mt1.getReturnType(), mt2.getReturnType())) { 494 continue outer; 495 } 496 } 497 bestSoFar = msym1; 498 } 499 if (phase2) { 500 break; 501 } else { 502 phase2 = true; 503 } 504 } 505 if (bestSoFar == null) return null; 506 507 //merge thrown types - form the intersection of all the thrown types in 508 //all the signatures in the list 509 boolean toErase = !bestSoFar.type.hasTag(FORALL); 510 List<Type> thrown = null; 511 Type mt1 = memberType(origin.type, bestSoFar); 512 for (Symbol msym2 : methodSyms) { 513 Type mt2 = memberType(origin.type, msym2); 514 List<Type> thrown_mt2 = mt2.getThrownTypes(); 515 if (toErase) { 516 thrown_mt2 = erasure(thrown_mt2); 517 } else { 518 /* If bestSoFar is generic then all the methods are generic. 519 * The opposite is not true: a non generic method can override 520 * a generic method (raw override) so it's safe to cast mt1 and 521 * mt2 to ForAll. 522 */ 523 ForAll fa1 = (ForAll)mt1; 524 ForAll fa2 = (ForAll)mt2; 525 thrown_mt2 = subst(thrown_mt2, fa2.tvars, fa1.tvars); 526 } 527 thrown = (thrown == null) ? 528 thrown_mt2 : 529 chk.intersect(thrown_mt2, thrown); 530 } 531 532 final List<Type> thrown1 = thrown; 533 return new FunctionDescriptor(bestSoFar) { 534 @Override 535 public Type getType(Type origin) { 536 Type mt = memberType(origin, getSymbol()); 537 return createMethodTypeWithThrown(mt, thrown1); 538 } 539 }; 540 } 541 542 boolean isSubtypeInternal(Type s, Type t) { 543 return (s.isPrimitive() && t.isPrimitive()) ? 544 isSameType(t, s) : 545 isSubtype(s, t); 546 } 547 548 FunctionDescriptorLookupError failure(String msg, Object... args) { 549 return failure(diags.fragment(msg, args)); 550 } 551 552 FunctionDescriptorLookupError failure(JCDiagnostic diag) { 553 return functionDescriptorLookupError.setMessage(diag); 554 } 555 } 556 557 private DescriptorCache descCache = new DescriptorCache(); 558 559 /** 560 * Find the method descriptor associated to this class symbol - if the 561 * symbol 'origin' is not a functional interface, an exception is thrown. 562 */ 563 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError { 564 return descCache.get(origin).getSymbol(); 565 } 566 567 /** 568 * Find the type of the method descriptor associated to this class symbol - 569 * if the symbol 'origin' is not a functional interface, an exception is thrown. 570 */ 571 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError { 572 return descCache.get(origin.tsym).getType(origin); 573 } 574 575 /** 576 * Is given type a functional interface? 577 */ 578 public boolean isFunctionalInterface(TypeSymbol tsym) { 579 try { 580 findDescriptorSymbol(tsym); 581 return true; 582 } catch (FunctionDescriptorLookupError ex) { 583 return false; 584 } 585 } 586 587 public boolean isFunctionalInterface(Type site) { 588 try { 589 findDescriptorType(site); 590 return true; 591 } catch (FunctionDescriptorLookupError ex) { 592 return false; 593 } 594 } 595 596 public Type removeWildcards(Type site) { 597 Type capturedSite = capture(site); 598 if (capturedSite != site) { 599 Type formalInterface = site.tsym.type; 600 ListBuffer<Type> typeargs = new ListBuffer<>(); 601 List<Type> actualTypeargs = site.getTypeArguments(); 602 List<Type> capturedTypeargs = capturedSite.getTypeArguments(); 603 //simply replace the wildcards with its bound 604 for (Type t : formalInterface.getTypeArguments()) { 605 if (actualTypeargs.head.hasTag(WILDCARD)) { 606 WildcardType wt = (WildcardType)actualTypeargs.head; 607 Type bound; 608 switch (wt.kind) { 609 case EXTENDS: 610 case UNBOUND: 611 CapturedType capVar = (CapturedType)capturedTypeargs.head; 612 //use declared bound if it doesn't depend on formal type-args 613 bound = capVar.bound.containsAny(capturedSite.getTypeArguments()) ? 614 wt.type : capVar.bound; 615 break; 616 default: 617 bound = wt.type; 618 } 619 typeargs.append(bound); 620 } else { 621 typeargs.append(actualTypeargs.head); 622 } 623 actualTypeargs = actualTypeargs.tail; 624 capturedTypeargs = capturedTypeargs.tail; 625 } 626 return subst(formalInterface, formalInterface.getTypeArguments(), typeargs.toList()); 627 } else { 628 return site; 629 } 630 } 631 632 /** 633 * Create a symbol for a class that implements a given functional interface 634 * and overrides its functional descriptor. This routine is used for two 635 * main purposes: (i) checking well-formedness of a functional interface; 636 * (ii) perform functional interface bridge calculation. 637 */ 638 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, List<Type> targets, long cflags) { 639 if (targets.isEmpty()) { 640 return null; 641 } 642 Symbol descSym = findDescriptorSymbol(targets.head.tsym); 643 Type descType = findDescriptorType(targets.head); 644 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass()); 645 csym.completer = null; 646 csym.members_field = WriteableScope.create(csym); 647 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym); 648 csym.members_field.enter(instDescSym); 649 Type.ClassType ctype = new Type.ClassType(Type.noType, List.<Type>nil(), csym); 650 ctype.supertype_field = syms.objectType; 651 ctype.interfaces_field = targets; 652 csym.type = ctype; 653 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile; 654 return csym; 655 } 656 657 /** 658 * Find the minimal set of methods that are overridden by the functional 659 * descriptor in 'origin'. All returned methods are assumed to have different 660 * erased signatures. 661 */ 662 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) { 663 Assert.check(isFunctionalInterface(origin)); 664 Symbol descSym = findDescriptorSymbol(origin); 665 CompoundScope members = membersClosure(origin.type, false); 666 ListBuffer<Symbol> overridden = new ListBuffer<>(); 667 outer: for (Symbol m2 : members.getSymbolsByName(descSym.name, bridgeFilter)) { 668 if (m2 == descSym) continue; 669 else if (descSym.overrides(m2, origin, Types.this, false)) { 670 for (Symbol m3 : overridden) { 671 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) || 672 (m3.overrides(m2, origin, Types.this, false) && 673 (pendingBridges((ClassSymbol)origin, m3.enclClass()) || 674 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) { 675 continue outer; 676 } 677 } 678 overridden.add(m2); 679 } 680 } 681 return overridden.toList(); 682 } 683 //where 684 private Filter<Symbol> bridgeFilter = new Filter<Symbol>() { 685 public boolean accepts(Symbol t) { 686 return t.kind == MTH && 687 t.name != names.init && 688 t.name != names.clinit && 689 (t.flags() & SYNTHETIC) == 0; 690 } 691 }; 692 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) { 693 //a symbol will be completed from a classfile if (a) symbol has 694 //an associated file object with CLASS kind and (b) the symbol has 695 //not been entered 696 if (origin.classfile != null && 697 origin.classfile.getKind() == JavaFileObject.Kind.CLASS && 698 enter.getEnv(origin) == null) { 699 return false; 700 } 701 if (origin == s) { 702 return true; 703 } 704 for (Type t : interfaces(origin.type)) { 705 if (pendingBridges((ClassSymbol)t.tsym, s)) { 706 return true; 707 } 708 } 709 return false; 710 } 711 // </editor-fold> 712 713 /** 714 * Scope filter used to skip methods that should be ignored (such as methods 715 * overridden by j.l.Object) during function interface conversion interface check 716 */ 717 class DescriptorFilter implements Filter<Symbol> { 718 719 TypeSymbol origin; 720 721 DescriptorFilter(TypeSymbol origin) { 722 this.origin = origin; 723 } 724 725 @Override 726 public boolean accepts(Symbol sym) { 727 return sym.kind == MTH && 728 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT && 729 !overridesObjectMethod(origin, sym) && 730 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0; 731 } 732 } 733 734 // <editor-fold defaultstate="collapsed" desc="isSubtype"> 735 /** 736 * Is t an unchecked subtype of s? 737 */ 738 public boolean isSubtypeUnchecked(Type t, Type s) { 739 return isSubtypeUnchecked(t, s, noWarnings); 740 } 741 /** 742 * Is t an unchecked subtype of s? 743 */ 744 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) { 745 boolean result = isSubtypeUncheckedInternal(t, s, warn); 746 if (result) { 747 checkUnsafeVarargsConversion(t, s, warn); 748 } 749 return result; 750 } 751 //where 752 private boolean isSubtypeUncheckedInternal(Type t, Type s, Warner warn) { 753 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) { 754 if (((ArrayType)t).elemtype.isPrimitive()) { 755 return isSameType(elemtype(t), elemtype(s)); 756 } else { 757 return isSubtypeUnchecked(elemtype(t), elemtype(s), warn); 758 } 759 } else if (isSubtype(t, s)) { 760 return true; 761 } else if (t.hasTag(TYPEVAR)) { 762 return isSubtypeUnchecked(t.getUpperBound(), s, warn); 763 } else if (!s.isRaw()) { 764 Type t2 = asSuper(t, s.tsym); 765 if (t2 != null && t2.isRaw()) { 766 if (isReifiable(s)) { 767 warn.silentWarn(LintCategory.UNCHECKED); 768 } else { 769 warn.warn(LintCategory.UNCHECKED); 770 } 771 return true; 772 } 773 } 774 return false; 775 } 776 777 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) { 778 if (!t.hasTag(ARRAY) || isReifiable(t)) { 779 return; 780 } 781 ArrayType from = (ArrayType)t; 782 boolean shouldWarn = false; 783 switch (s.getTag()) { 784 case ARRAY: 785 ArrayType to = (ArrayType)s; 786 shouldWarn = from.isVarargs() && 787 !to.isVarargs() && 788 !isReifiable(from); 789 break; 790 case CLASS: 791 shouldWarn = from.isVarargs(); 792 break; 793 } 794 if (shouldWarn) { 795 warn.warn(LintCategory.VARARGS); 796 } 797 } 798 799 /** 800 * Is t a subtype of s?<br> 801 * (not defined for Method and ForAll types) 802 */ 803 final public boolean isSubtype(Type t, Type s) { 804 return isSubtype(t, s, true); 805 } 806 final public boolean isSubtypeNoCapture(Type t, Type s) { 807 return isSubtype(t, s, false); 808 } 809 public boolean isSubtype(Type t, Type s, boolean capture) { 810 if (t == s) 811 return true; 812 if (s.isPartial()) 813 return isSuperType(s, t); 814 815 if (s.isCompound()) { 816 for (Type s2 : interfaces(s).prepend(supertype(s))) { 817 if (!isSubtype(t, s2, capture)) 818 return false; 819 } 820 return true; 821 } 822 823 // Generally, if 's' is a lower-bounded type variable, recur on lower bound; but 824 // for inference variables and intersections, we need to keep 's' 825 // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars) 826 if (!t.hasTag(UNDETVAR) && !t.isCompound()) { 827 // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s 828 Type lower = cvarLowerBound(wildLowerBound(s)); 829 if (s != lower && !lower.hasTag(BOT)) 830 return isSubtype(capture ? capture(t) : t, lower, false); 831 } 832 833 return isSubtype.visit(capture ? capture(t) : t, s); 834 } 835 // where 836 private TypeRelation isSubtype = new TypeRelation() 837 { 838 @Override 839 public Boolean visitType(Type t, Type s) { 840 switch (t.getTag()) { 841 case BYTE: 842 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag())); 843 case CHAR: 844 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag())); 845 case SHORT: case INT: case LONG: 846 case FLOAT: case DOUBLE: 847 return t.getTag().isSubRangeOf(s.getTag()); 848 case BOOLEAN: case VOID: 849 return t.hasTag(s.getTag()); 850 case TYPEVAR: 851 return isSubtypeNoCapture(t.getUpperBound(), s); 852 case BOT: 853 return 854 s.hasTag(BOT) || s.hasTag(CLASS) || 855 s.hasTag(ARRAY) || s.hasTag(TYPEVAR); 856 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495) 857 case NONE: 858 return false; 859 default: 860 throw new AssertionError("isSubtype " + t.getTag()); 861 } 862 } 863 864 private Set<TypePair> cache = new HashSet<>(); 865 866 private boolean containsTypeRecursive(Type t, Type s) { 867 TypePair pair = new TypePair(t, s); 868 if (cache.add(pair)) { 869 try { 870 return containsType(t.getTypeArguments(), 871 s.getTypeArguments()); 872 } finally { 873 cache.remove(pair); 874 } 875 } else { 876 return containsType(t.getTypeArguments(), 877 rewriteSupers(s).getTypeArguments()); 878 } 879 } 880 881 private Type rewriteSupers(Type t) { 882 if (!t.isParameterized()) 883 return t; 884 ListBuffer<Type> from = new ListBuffer<>(); 885 ListBuffer<Type> to = new ListBuffer<>(); 886 adaptSelf(t, from, to); 887 if (from.isEmpty()) 888 return t; 889 ListBuffer<Type> rewrite = new ListBuffer<>(); 890 boolean changed = false; 891 for (Type orig : to.toList()) { 892 Type s = rewriteSupers(orig); 893 if (s.isSuperBound() && !s.isExtendsBound()) { 894 s = new WildcardType(syms.objectType, 895 BoundKind.UNBOUND, 896 syms.boundClass, 897 s.getMetadata()); 898 changed = true; 899 } else if (s != orig) { 900 s = new WildcardType(wildUpperBound(s), 901 BoundKind.EXTENDS, 902 syms.boundClass, 903 s.getMetadata()); 904 changed = true; 905 } 906 rewrite.append(s); 907 } 908 if (changed) 909 return subst(t.tsym.type, from.toList(), rewrite.toList()); 910 else 911 return t; 912 } 913 914 @Override 915 public Boolean visitClassType(ClassType t, Type s) { 916 Type sup = asSuper(t, s.tsym); 917 if (sup == null) return false; 918 // If t is an intersection, sup might not be a class type 919 if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s); 920 return sup.tsym == s.tsym 921 // Check type variable containment 922 && (!s.isParameterized() || containsTypeRecursive(s, sup)) 923 && isSubtypeNoCapture(sup.getEnclosingType(), 924 s.getEnclosingType()); 925 } 926 927 @Override 928 public Boolean visitArrayType(ArrayType t, Type s) { 929 if (s.hasTag(ARRAY)) { 930 if (t.elemtype.isPrimitive()) 931 return isSameType(t.elemtype, elemtype(s)); 932 else 933 return isSubtypeNoCapture(t.elemtype, elemtype(s)); 934 } 935 936 if (s.hasTag(CLASS)) { 937 Name sname = s.tsym.getQualifiedName(); 938 return sname == names.java_lang_Object 939 || sname == names.java_lang_Cloneable 940 || sname == names.java_io_Serializable; 941 } 942 943 return false; 944 } 945 946 @Override 947 public Boolean visitUndetVar(UndetVar t, Type s) { 948 //todo: test against origin needed? or replace with substitution? 949 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) { 950 return true; 951 } else if (s.hasTag(BOT)) { 952 //if 's' is 'null' there's no instantiated type U for which 953 //U <: s (but 'null' itself, which is not a valid type) 954 return false; 955 } 956 957 t.addBound(InferenceBound.UPPER, s, Types.this); 958 return true; 959 } 960 961 @Override 962 public Boolean visitErrorType(ErrorType t, Type s) { 963 return true; 964 } 965 }; 966 967 /** 968 * Is t a subtype of every type in given list `ts'?<br> 969 * (not defined for Method and ForAll types)<br> 970 * Allows unchecked conversions. 971 */ 972 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) { 973 for (List<Type> l = ts; l.nonEmpty(); l = l.tail) 974 if (!isSubtypeUnchecked(t, l.head, warn)) 975 return false; 976 return true; 977 } 978 979 /** 980 * Are corresponding elements of ts subtypes of ss? If lists are 981 * of different length, return false. 982 */ 983 public boolean isSubtypes(List<Type> ts, List<Type> ss) { 984 while (ts.tail != null && ss.tail != null 985 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 986 isSubtype(ts.head, ss.head)) { 987 ts = ts.tail; 988 ss = ss.tail; 989 } 990 return ts.tail == null && ss.tail == null; 991 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 992 } 993 994 /** 995 * Are corresponding elements of ts subtypes of ss, allowing 996 * unchecked conversions? If lists are of different length, 997 * return false. 998 **/ 999 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) { 1000 while (ts.tail != null && ss.tail != null 1001 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1002 isSubtypeUnchecked(ts.head, ss.head, warn)) { 1003 ts = ts.tail; 1004 ss = ss.tail; 1005 } 1006 return ts.tail == null && ss.tail == null; 1007 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1008 } 1009 // </editor-fold> 1010 1011 // <editor-fold defaultstate="collapsed" desc="isSuperType"> 1012 /** 1013 * Is t a supertype of s? 1014 */ 1015 public boolean isSuperType(Type t, Type s) { 1016 switch (t.getTag()) { 1017 case ERROR: 1018 return true; 1019 case UNDETVAR: { 1020 UndetVar undet = (UndetVar)t; 1021 if (t == s || 1022 undet.qtype == s || 1023 s.hasTag(ERROR) || 1024 s.hasTag(BOT)) { 1025 return true; 1026 } 1027 undet.addBound(InferenceBound.LOWER, s, this); 1028 return true; 1029 } 1030 default: 1031 return isSubtype(s, t); 1032 } 1033 } 1034 // </editor-fold> 1035 1036 // <editor-fold defaultstate="collapsed" desc="isSameType"> 1037 /** 1038 * Are corresponding elements of the lists the same type? If 1039 * lists are of different length, return false. 1040 */ 1041 public boolean isSameTypes(List<Type> ts, List<Type> ss) { 1042 return isSameTypes(ts, ss, false); 1043 } 1044 public boolean isSameTypes(List<Type> ts, List<Type> ss, boolean strict) { 1045 while (ts.tail != null && ss.tail != null 1046 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && 1047 isSameType(ts.head, ss.head, strict)) { 1048 ts = ts.tail; 1049 ss = ss.tail; 1050 } 1051 return ts.tail == null && ss.tail == null; 1052 /*inlined: ts.isEmpty() && ss.isEmpty();*/ 1053 } 1054 1055 /** 1056 * A polymorphic signature method (JLS SE 7, 8.4.1) is a method that 1057 * (i) is declared in the java.lang.invoke.MethodHandle class, (ii) takes 1058 * a single variable arity parameter (iii) whose declared type is Object[], 1059 * (iv) has a return type of Object and (v) is native. 1060 */ 1061 public boolean isSignaturePolymorphic(MethodSymbol msym) { 1062 List<Type> argtypes = msym.type.getParameterTypes(); 1063 return (msym.flags_field & NATIVE) != 0 && 1064 msym.owner == syms.methodHandleType.tsym && 1065 argtypes.tail.tail == null && 1066 argtypes.head.hasTag(TypeTag.ARRAY) && 1067 msym.type.getReturnType().tsym == syms.objectType.tsym && 1068 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym; 1069 } 1070 1071 /** 1072 * Is t the same type as s? 1073 */ 1074 public boolean isSameType(Type t, Type s) { 1075 return isSameType(t, s, false); 1076 } 1077 public boolean isSameType(Type t, Type s, boolean strict) { 1078 return strict ? 1079 isSameTypeStrict.visit(t, s) : 1080 isSameTypeLoose.visit(t, s); 1081 } 1082 public boolean isSameAnnotatedType(Type t, Type s) { 1083 return isSameAnnotatedType.visit(t, s); 1084 } 1085 // where 1086 abstract class SameTypeVisitor extends TypeRelation { 1087 1088 public Boolean visitType(Type t, Type s) { 1089 if (t == 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 TypeRelation isSameAnnotatedType = new LooseSameTypeVisitor() { 1283 private Boolean compareAnnotations(Type t1, Type t2) { 1284 List<Attribute.TypeCompound> annos1 = t1.getAnnotationMirrors(); 1285 List<Attribute.TypeCompound> annos2 = t2.getAnnotationMirrors(); 1286 return annos1.containsAll(annos2) && annos2.containsAll(annos1); 1287 } 1288 1289 @Override 1290 public Boolean visitType(Type t, Type s) { 1291 return compareAnnotations(t, s) && super.visitType(t, s); 1292 } 1293 1294 @Override 1295 public Boolean visitWildcardType(WildcardType t, Type s) { 1296 return compareAnnotations(t, s) && super.visitWildcardType(t, s); 1297 } 1298 1299 @Override 1300 public Boolean visitClassType(ClassType t, Type s) { 1301 return compareAnnotations(t, s) && super.visitClassType(t, s); 1302 } 1303 1304 @Override 1305 public Boolean visitArrayType(ArrayType t, Type s) { 1306 return compareAnnotations(t, s) && super.visitArrayType(t, s); 1307 } 1308 1309 @Override 1310 public Boolean visitForAll(ForAll t, Type s) { 1311 return compareAnnotations(t, s) && super.visitForAll(t, s); 1312 } 1313 }; 1314 1315 // <editor-fold defaultstate="collapsed" desc="Contains Type"> 1316 public boolean containedBy(Type t, Type s) { 1317 switch (t.getTag()) { 1318 case UNDETVAR: 1319 if (s.hasTag(WILDCARD)) { 1320 UndetVar undetvar = (UndetVar)t; 1321 WildcardType wt = (WildcardType)s; 1322 switch(wt.kind) { 1323 case UNBOUND: 1324 break; 1325 case EXTENDS: { 1326 Type bound = wildUpperBound(s); 1327 undetvar.addBound(InferenceBound.UPPER, bound, this); 1328 break; 1329 } 1330 case SUPER: { 1331 Type bound = wildLowerBound(s); 1332 undetvar.addBound(InferenceBound.LOWER, bound, this); 1333 break; 1334 } 1335 } 1336 return true; 1337 } else { 1338 return isSameType(t, s); 1339 } 1340 case ERROR: 1341 return true; 1342 default: 1343 return containsType(s, t); 1344 } 1345 } 1346 1347 boolean containsType(List<Type> ts, List<Type> ss) { 1348 while (ts.nonEmpty() && ss.nonEmpty() 1349 && containsType(ts.head, ss.head)) { 1350 ts = ts.tail; 1351 ss = ss.tail; 1352 } 1353 return ts.isEmpty() && ss.isEmpty(); 1354 } 1355 1356 /** 1357 * Check if t contains s. 1358 * 1359 * <p>T contains S if: 1360 * 1361 * <p>{@code L(T) <: L(S) && U(S) <: U(T)} 1362 * 1363 * <p>This relation is only used by ClassType.isSubtype(), that 1364 * is, 1365 * 1366 * <p>{@code C<S> <: C<T> if T contains S.} 1367 * 1368 * <p>Because of F-bounds, this relation can lead to infinite 1369 * recursion. Thus we must somehow break that recursion. Notice 1370 * that containsType() is only called from ClassType.isSubtype(). 1371 * Since the arguments have already been checked against their 1372 * bounds, we know: 1373 * 1374 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)} 1375 * 1376 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)} 1377 * 1378 * @param t a type 1379 * @param s a type 1380 */ 1381 public boolean containsType(Type t, Type s) { 1382 return containsType.visit(t, s); 1383 } 1384 // where 1385 private TypeRelation containsType = new TypeRelation() { 1386 1387 public Boolean visitType(Type t, Type s) { 1388 if (s.isPartial()) 1389 return containedBy(s, t); 1390 else 1391 return isSameType(t, s); 1392 } 1393 1394// void debugContainsType(WildcardType t, Type s) { 1395// System.err.println(); 1396// System.err.format(" does %s contain %s?%n", t, s); 1397// System.err.format(" %s U(%s) <: U(%s) %s = %s%n", 1398// wildUpperBound(s), s, t, wildUpperBound(t), 1399// t.isSuperBound() 1400// || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t))); 1401// System.err.format(" %s L(%s) <: L(%s) %s = %s%n", 1402// wildLowerBound(t), t, s, wildLowerBound(s), 1403// t.isExtendsBound() 1404// || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))); 1405// System.err.println(); 1406// } 1407 1408 @Override 1409 public Boolean visitWildcardType(WildcardType t, Type s) { 1410 if (s.isPartial()) 1411 return containedBy(s, t); 1412 else { 1413// debugContainsType(t, s); 1414 return isSameWildcard(t, s) 1415 || isCaptureOf(s, t) 1416 || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) && 1417 (t.isSuperBound() || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t)))); 1418 } 1419 } 1420 1421 @Override 1422 public Boolean visitUndetVar(UndetVar t, Type s) { 1423 if (!s.hasTag(WILDCARD)) { 1424 return isSameType(t, s); 1425 } else { 1426 return false; 1427 } 1428 } 1429 1430 @Override 1431 public Boolean visitErrorType(ErrorType t, Type s) { 1432 return true; 1433 } 1434 }; 1435 1436 public boolean isCaptureOf(Type s, WildcardType t) { 1437 if (!s.hasTag(TYPEVAR) || !((TypeVar)s).isCaptured()) 1438 return false; 1439 return isSameWildcard(t, ((CapturedType)s).wildcard); 1440 } 1441 1442 public boolean isSameWildcard(WildcardType t, Type s) { 1443 if (!s.hasTag(WILDCARD)) 1444 return false; 1445 WildcardType w = (WildcardType)s; 1446 return w.kind == t.kind && w.type == t.type; 1447 } 1448 1449 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) { 1450 while (ts.nonEmpty() && ss.nonEmpty() 1451 && containsTypeEquivalent(ts.head, ss.head)) { 1452 ts = ts.tail; 1453 ss = ss.tail; 1454 } 1455 return ts.isEmpty() && ss.isEmpty(); 1456 } 1457 // </editor-fold> 1458 1459 // <editor-fold defaultstate="collapsed" desc="isCastable"> 1460 public boolean isCastable(Type t, Type s) { 1461 return isCastable(t, s, noWarnings); 1462 } 1463 1464 /** 1465 * Is t is castable to s?<br> 1466 * s is assumed to be an erased type.<br> 1467 * (not defined for Method and ForAll types). 1468 */ 1469 public boolean isCastable(Type t, Type s, Warner warn) { 1470 if (t == s) 1471 return true; 1472 1473 if (t.isPrimitive() != s.isPrimitive()) 1474 return (isConvertible(t, s, warn) 1475 || (allowObjectToPrimitiveCast && 1476 s.isPrimitive() && 1477 isSubtype(boxedClass(s).type, t))); 1478 if (warn != warnStack.head) { 1479 try { 1480 warnStack = warnStack.prepend(warn); 1481 checkUnsafeVarargsConversion(t, s, warn); 1482 return isCastable.visit(t,s); 1483 } finally { 1484 warnStack = warnStack.tail; 1485 } 1486 } else { 1487 return isCastable.visit(t,s); 1488 } 1489 } 1490 // where 1491 private TypeRelation isCastable = new TypeRelation() { 1492 1493 public Boolean visitType(Type t, Type s) { 1494 if (s.hasTag(ERROR)) 1495 return true; 1496 1497 switch (t.getTag()) { 1498 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: 1499 case DOUBLE: 1500 return s.isNumeric(); 1501 case BOOLEAN: 1502 return s.hasTag(BOOLEAN); 1503 case VOID: 1504 return false; 1505 case BOT: 1506 return isSubtype(t, s); 1507 default: 1508 throw new AssertionError(); 1509 } 1510 } 1511 1512 @Override 1513 public Boolean visitWildcardType(WildcardType t, Type s) { 1514 return isCastable(wildUpperBound(t), s, warnStack.head); 1515 } 1516 1517 @Override 1518 public Boolean visitClassType(ClassType t, Type s) { 1519 if (s.hasTag(ERROR) || s.hasTag(BOT)) 1520 return true; 1521 1522 if (s.hasTag(TYPEVAR)) { 1523 if (isCastable(t, s.getUpperBound(), noWarnings)) { 1524 warnStack.head.warn(LintCategory.UNCHECKED); 1525 return true; 1526 } else { 1527 return false; 1528 } 1529 } 1530 1531 if (t.isIntersection() || s.isIntersection()) { 1532 return !t.isIntersection() ? 1533 visitIntersectionType((IntersectionClassType)s, t, true) : 1534 visitIntersectionType((IntersectionClassType)t, s, false); 1535 } 1536 1537 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) { 1538 boolean upcast; 1539 if ((upcast = isSubtype(erasure(t), erasure(s))) 1540 || isSubtype(erasure(s), erasure(t))) { 1541 if (!upcast && s.hasTag(ARRAY)) { 1542 if (!isReifiable(s)) 1543 warnStack.head.warn(LintCategory.UNCHECKED); 1544 return true; 1545 } else if (s.isRaw()) { 1546 return true; 1547 } else if (t.isRaw()) { 1548 if (!isUnbounded(s)) 1549 warnStack.head.warn(LintCategory.UNCHECKED); 1550 return true; 1551 } 1552 // Assume |a| <: |b| 1553 final Type a = upcast ? t : s; 1554 final Type b = upcast ? s : t; 1555 final boolean HIGH = true; 1556 final boolean LOW = false; 1557 final boolean DONT_REWRITE_TYPEVARS = false; 1558 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS); 1559 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS); 1560 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS); 1561 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS); 1562 Type lowSub = asSub(bLow, aLow.tsym); 1563 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); 1564 if (highSub == null) { 1565 final boolean REWRITE_TYPEVARS = true; 1566 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS); 1567 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS); 1568 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS); 1569 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS); 1570 lowSub = asSub(bLow, aLow.tsym); 1571 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); 1572 } 1573 if (highSub != null) { 1574 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) { 1575 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym); 1576 } 1577 if (!disjointTypes(aHigh.allparams(), highSub.allparams()) 1578 && !disjointTypes(aHigh.allparams(), lowSub.allparams()) 1579 && !disjointTypes(aLow.allparams(), highSub.allparams()) 1580 && !disjointTypes(aLow.allparams(), lowSub.allparams())) { 1581 if (upcast ? giveWarning(a, b) : 1582 giveWarning(b, a)) 1583 warnStack.head.warn(LintCategory.UNCHECKED); 1584 return true; 1585 } 1586 } 1587 if (isReifiable(s)) 1588 return isSubtypeUnchecked(a, b); 1589 else 1590 return isSubtypeUnchecked(a, b, warnStack.head); 1591 } 1592 1593 // Sidecast 1594 if (s.hasTag(CLASS)) { 1595 if ((s.tsym.flags() & INTERFACE) != 0) { 1596 return ((t.tsym.flags() & FINAL) == 0) 1597 ? sideCast(t, s, warnStack.head) 1598 : sideCastFinal(t, s, warnStack.head); 1599 } else if ((t.tsym.flags() & INTERFACE) != 0) { 1600 return ((s.tsym.flags() & FINAL) == 0) 1601 ? sideCast(t, s, warnStack.head) 1602 : sideCastFinal(t, s, warnStack.head); 1603 } else { 1604 // unrelated class types 1605 return false; 1606 } 1607 } 1608 } 1609 return false; 1610 } 1611 1612 boolean visitIntersectionType(IntersectionClassType ict, Type s, boolean reverse) { 1613 Warner warn = noWarnings; 1614 for (Type c : ict.getComponents()) { 1615 warn.clear(); 1616 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn)) 1617 return false; 1618 } 1619 if (warn.hasLint(LintCategory.UNCHECKED)) 1620 warnStack.head.warn(LintCategory.UNCHECKED); 1621 return true; 1622 } 1623 1624 @Override 1625 public Boolean visitArrayType(ArrayType t, Type s) { 1626 switch (s.getTag()) { 1627 case ERROR: 1628 case BOT: 1629 return true; 1630 case TYPEVAR: 1631 if (isCastable(s, t, noWarnings)) { 1632 warnStack.head.warn(LintCategory.UNCHECKED); 1633 return true; 1634 } else { 1635 return false; 1636 } 1637 case CLASS: 1638 return isSubtype(t, s); 1639 case ARRAY: 1640 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) { 1641 return elemtype(t).hasTag(elemtype(s).getTag()); 1642 } else { 1643 return visit(elemtype(t), elemtype(s)); 1644 } 1645 default: 1646 return false; 1647 } 1648 } 1649 1650 @Override 1651 public Boolean visitTypeVar(TypeVar t, Type s) { 1652 switch (s.getTag()) { 1653 case ERROR: 1654 case BOT: 1655 return true; 1656 case TYPEVAR: 1657 if (isSubtype(t, s)) { 1658 return true; 1659 } else if (isCastable(t.bound, s, noWarnings)) { 1660 warnStack.head.warn(LintCategory.UNCHECKED); 1661 return true; 1662 } else { 1663 return false; 1664 } 1665 default: 1666 return isCastable(t.bound, s, warnStack.head); 1667 } 1668 } 1669 1670 @Override 1671 public Boolean visitErrorType(ErrorType t, Type s) { 1672 return true; 1673 } 1674 }; 1675 // </editor-fold> 1676 1677 // <editor-fold defaultstate="collapsed" desc="disjointTypes"> 1678 public boolean disjointTypes(List<Type> ts, List<Type> ss) { 1679 while (ts.tail != null && ss.tail != null) { 1680 if (disjointType(ts.head, ss.head)) return true; 1681 ts = ts.tail; 1682 ss = ss.tail; 1683 } 1684 return false; 1685 } 1686 1687 /** 1688 * Two types or wildcards are considered disjoint if it can be 1689 * proven that no type can be contained in both. It is 1690 * conservative in that it is allowed to say that two types are 1691 * not disjoint, even though they actually are. 1692 * 1693 * The type {@code C<X>} is castable to {@code C<Y>} exactly if 1694 * {@code X} and {@code Y} are not disjoint. 1695 */ 1696 public boolean disjointType(Type t, Type s) { 1697 return disjointType.visit(t, s); 1698 } 1699 // where 1700 private TypeRelation disjointType = new TypeRelation() { 1701 1702 private Set<TypePair> cache = new HashSet<>(); 1703 1704 @Override 1705 public Boolean visitType(Type t, Type s) { 1706 if (s.hasTag(WILDCARD)) 1707 return visit(s, t); 1708 else 1709 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t); 1710 } 1711 1712 private boolean isCastableRecursive(Type t, Type s) { 1713 TypePair pair = new TypePair(t, s); 1714 if (cache.add(pair)) { 1715 try { 1716 return Types.this.isCastable(t, s); 1717 } finally { 1718 cache.remove(pair); 1719 } 1720 } else { 1721 return true; 1722 } 1723 } 1724 1725 private boolean notSoftSubtypeRecursive(Type t, Type s) { 1726 TypePair pair = new TypePair(t, s); 1727 if (cache.add(pair)) { 1728 try { 1729 return Types.this.notSoftSubtype(t, s); 1730 } finally { 1731 cache.remove(pair); 1732 } 1733 } else { 1734 return false; 1735 } 1736 } 1737 1738 @Override 1739 public Boolean visitWildcardType(WildcardType t, Type s) { 1740 if (t.isUnbound()) 1741 return false; 1742 1743 if (!s.hasTag(WILDCARD)) { 1744 if (t.isExtendsBound()) 1745 return notSoftSubtypeRecursive(s, t.type); 1746 else 1747 return notSoftSubtypeRecursive(t.type, s); 1748 } 1749 1750 if (s.isUnbound()) 1751 return false; 1752 1753 if (t.isExtendsBound()) { 1754 if (s.isExtendsBound()) 1755 return !isCastableRecursive(t.type, wildUpperBound(s)); 1756 else if (s.isSuperBound()) 1757 return notSoftSubtypeRecursive(wildLowerBound(s), t.type); 1758 } else if (t.isSuperBound()) { 1759 if (s.isExtendsBound()) 1760 return notSoftSubtypeRecursive(t.type, wildUpperBound(s)); 1761 } 1762 return false; 1763 } 1764 }; 1765 // </editor-fold> 1766 1767 // <editor-fold defaultstate="collapsed" desc="cvarLowerBounds"> 1768 public List<Type> cvarLowerBounds(List<Type> ts) { 1769 return map(ts, cvarLowerBoundMapping); 1770 } 1771 private final Mapping cvarLowerBoundMapping = new Mapping("cvarLowerBound") { 1772 public Type apply(Type t) { 1773 return cvarLowerBound(t); 1774 } 1775 }; 1776 // </editor-fold> 1777 1778 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype"> 1779 /** 1780 * This relation answers the question: is impossible that 1781 * something of type `t' can be a subtype of `s'? This is 1782 * different from the question "is `t' not a subtype of `s'?" 1783 * when type variables are involved: Integer is not a subtype of T 1784 * where {@code <T extends Number>} but it is not true that Integer cannot 1785 * possibly be a subtype of T. 1786 */ 1787 public boolean notSoftSubtype(Type t, Type s) { 1788 if (t == s) return false; 1789 if (t.hasTag(TYPEVAR)) { 1790 TypeVar tv = (TypeVar) t; 1791 return !isCastable(tv.bound, 1792 relaxBound(s), 1793 noWarnings); 1794 } 1795 if (!s.hasTag(WILDCARD)) 1796 s = cvarUpperBound(s); 1797 1798 return !isSubtype(t, relaxBound(s)); 1799 } 1800 1801 private Type relaxBound(Type t) { 1802 return (t.hasTag(TYPEVAR)) ? 1803 rewriteQuantifiers(skipTypeVars(t, false), true, true) : 1804 t; 1805 } 1806 // </editor-fold> 1807 1808 // <editor-fold defaultstate="collapsed" desc="isReifiable"> 1809 public boolean isReifiable(Type t) { 1810 return isReifiable.visit(t); 1811 } 1812 // where 1813 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() { 1814 1815 public Boolean visitType(Type t, Void ignored) { 1816 return true; 1817 } 1818 1819 @Override 1820 public Boolean visitClassType(ClassType t, Void ignored) { 1821 if (t.isCompound()) 1822 return false; 1823 else { 1824 if (!t.isParameterized()) 1825 return true; 1826 1827 for (Type param : t.allparams()) { 1828 if (!param.isUnbound()) 1829 return false; 1830 } 1831 return true; 1832 } 1833 } 1834 1835 @Override 1836 public Boolean visitArrayType(ArrayType t, Void ignored) { 1837 return visit(t.elemtype); 1838 } 1839 1840 @Override 1841 public Boolean visitTypeVar(TypeVar t, Void ignored) { 1842 return false; 1843 } 1844 }; 1845 // </editor-fold> 1846 1847 // <editor-fold defaultstate="collapsed" desc="Array Utils"> 1848 public boolean isArray(Type t) { 1849 while (t.hasTag(WILDCARD)) 1850 t = wildUpperBound(t); 1851 return t.hasTag(ARRAY); 1852 } 1853 1854 /** 1855 * The element type of an array. 1856 */ 1857 public Type elemtype(Type t) { 1858 switch (t.getTag()) { 1859 case WILDCARD: 1860 return elemtype(wildUpperBound(t)); 1861 case ARRAY: 1862 return ((ArrayType)t).elemtype; 1863 case FORALL: 1864 return elemtype(((ForAll)t).qtype); 1865 case ERROR: 1866 return t; 1867 default: 1868 return null; 1869 } 1870 } 1871 1872 public Type elemtypeOrType(Type t) { 1873 Type elemtype = elemtype(t); 1874 return elemtype != null ? 1875 elemtype : 1876 t; 1877 } 1878 1879 /** 1880 * Mapping to take element type of an arraytype 1881 */ 1882 private Mapping elemTypeFun = new Mapping ("elemTypeFun") { 1883 public Type apply(Type t) { 1884 return elemtype(skipTypeVars(t, false)); 1885 } 1886 }; 1887 1888 /** 1889 * The number of dimensions of an array type. 1890 */ 1891 public int dimensions(Type t) { 1892 int result = 0; 1893 while (t.hasTag(ARRAY)) { 1894 result++; 1895 t = elemtype(t); 1896 } 1897 return result; 1898 } 1899 1900 /** 1901 * Returns an ArrayType with the component type t 1902 * 1903 * @param t The component type of the ArrayType 1904 * @return the ArrayType for the given component 1905 */ 1906 public ArrayType makeArrayType(Type t) { 1907 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) { 1908 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString()); 1909 } 1910 return new ArrayType(t, syms.arrayClass); 1911 } 1912 // </editor-fold> 1913 1914 // <editor-fold defaultstate="collapsed" desc="asSuper"> 1915 /** 1916 * Return the (most specific) base type of t that starts with the 1917 * given symbol. If none exists, return null. 1918 * 1919 * Caveat Emptor: Since javac represents the class of all arrays with a singleton 1920 * symbol Symtab.arrayClass, which by being a singleton cannot hold any discriminant, 1921 * this method could yield surprising answers when invoked on arrays. For example when 1922 * invoked with t being byte [] and sym being t.sym itself, asSuper would answer null. 1923 * 1924 * @param t a type 1925 * @param sym a symbol 1926 */ 1927 public Type asSuper(Type t, Symbol sym) { 1928 /* Some examples: 1929 * 1930 * (Enum<E>, Comparable) => Comparable<E> 1931 * (c.s.s.d.AttributeTree.ValueKind, Enum) => Enum<c.s.s.d.AttributeTree.ValueKind> 1932 * (c.s.s.t.ExpressionTree, c.s.s.t.Tree) => c.s.s.t.Tree 1933 * (j.u.List<capture#160 of ? extends c.s.s.d.DocTree>, Iterable) => 1934 * Iterable<capture#160 of ? extends c.s.s.d.DocTree> 1935 */ 1936 if (sym.type == syms.objectType) { //optimization 1937 return syms.objectType; 1938 } 1939 return asSuper.visit(t, sym); 1940 } 1941 // where 1942 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() { 1943 1944 public Type visitType(Type t, Symbol sym) { 1945 return null; 1946 } 1947 1948 @Override 1949 public Type visitClassType(ClassType t, Symbol sym) { 1950 if (t.tsym == sym) 1951 return t; 1952 1953 Type st = supertype(t); 1954 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) { 1955 Type x = asSuper(st, sym); 1956 if (x != null) 1957 return x; 1958 } 1959 if ((sym.flags() & INTERFACE) != 0) { 1960 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { 1961 if (!l.head.hasTag(ERROR)) { 1962 Type x = asSuper(l.head, sym); 1963 if (x != null) 1964 return x; 1965 } 1966 } 1967 } 1968 return null; 1969 } 1970 1971 @Override 1972 public Type visitArrayType(ArrayType t, Symbol sym) { 1973 return isSubtype(t, sym.type) ? sym.type : null; 1974 } 1975 1976 @Override 1977 public Type visitTypeVar(TypeVar t, Symbol sym) { 1978 if (t.tsym == sym) 1979 return t; 1980 else 1981 return asSuper(t.bound, sym); 1982 } 1983 1984 @Override 1985 public Type visitErrorType(ErrorType t, Symbol sym) { 1986 return t; 1987 } 1988 }; 1989 1990 /** 1991 * Return the base type of t or any of its outer types that starts 1992 * with the given symbol. If none exists, return null. 1993 * 1994 * @param t a type 1995 * @param sym a symbol 1996 */ 1997 public Type asOuterSuper(Type t, Symbol sym) { 1998 switch (t.getTag()) { 1999 case CLASS: 2000 do { 2001 Type s = asSuper(t, sym); 2002 if (s != null) return s; 2003 t = t.getEnclosingType(); 2004 } while (t.hasTag(CLASS)); 2005 return null; 2006 case ARRAY: 2007 return isSubtype(t, sym.type) ? sym.type : null; 2008 case TYPEVAR: 2009 return asSuper(t, sym); 2010 case ERROR: 2011 return t; 2012 default: 2013 return null; 2014 } 2015 } 2016 2017 /** 2018 * Return the base type of t or any of its enclosing types that 2019 * starts with the given symbol. If none exists, return null. 2020 * 2021 * @param t a type 2022 * @param sym a symbol 2023 */ 2024 public Type asEnclosingSuper(Type t, Symbol sym) { 2025 switch (t.getTag()) { 2026 case CLASS: 2027 do { 2028 Type s = asSuper(t, sym); 2029 if (s != null) return s; 2030 Type outer = t.getEnclosingType(); 2031 t = (outer.hasTag(CLASS)) ? outer : 2032 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type : 2033 Type.noType; 2034 } while (t.hasTag(CLASS)); 2035 return null; 2036 case ARRAY: 2037 return isSubtype(t, sym.type) ? sym.type : null; 2038 case TYPEVAR: 2039 return asSuper(t, sym); 2040 case ERROR: 2041 return t; 2042 default: 2043 return null; 2044 } 2045 } 2046 // </editor-fold> 2047 2048 // <editor-fold defaultstate="collapsed" desc="memberType"> 2049 /** 2050 * The type of given symbol, seen as a member of t. 2051 * 2052 * @param t a type 2053 * @param sym a symbol 2054 */ 2055 public Type memberType(Type t, Symbol sym) { 2056 return (sym.flags() & STATIC) != 0 2057 ? sym.type 2058 : memberType.visit(t, sym); 2059 } 2060 // where 2061 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() { 2062 2063 public Type visitType(Type t, Symbol sym) { 2064 return sym.type; 2065 } 2066 2067 @Override 2068 public Type visitWildcardType(WildcardType t, Symbol sym) { 2069 return memberType(wildUpperBound(t), sym); 2070 } 2071 2072 @Override 2073 public Type visitClassType(ClassType t, Symbol sym) { 2074 Symbol owner = sym.owner; 2075 long flags = sym.flags(); 2076 if (((flags & STATIC) == 0) && owner.type.isParameterized()) { 2077 Type base = asOuterSuper(t, owner); 2078 //if t is an intersection type T = CT & I1 & I2 ... & In 2079 //its supertypes CT, I1, ... In might contain wildcards 2080 //so we need to go through capture conversion 2081 base = t.isCompound() ? capture(base) : base; 2082 if (base != null) { 2083 List<Type> ownerParams = owner.type.allparams(); 2084 List<Type> baseParams = base.allparams(); 2085 if (ownerParams.nonEmpty()) { 2086 if (baseParams.isEmpty()) { 2087 // then base is a raw type 2088 return erasure(sym.type); 2089 } else { 2090 return subst(sym.type, ownerParams, baseParams); 2091 } 2092 } 2093 } 2094 } 2095 return sym.type; 2096 } 2097 2098 @Override 2099 public Type visitTypeVar(TypeVar t, Symbol sym) { 2100 return memberType(t.bound, sym); 2101 } 2102 2103 @Override 2104 public Type visitErrorType(ErrorType t, Symbol sym) { 2105 return t; 2106 } 2107 }; 2108 // </editor-fold> 2109 2110 // <editor-fold defaultstate="collapsed" desc="isAssignable"> 2111 public boolean isAssignable(Type t, Type s) { 2112 return isAssignable(t, s, noWarnings); 2113 } 2114 2115 /** 2116 * Is t assignable to s?<br> 2117 * Equivalent to subtype except for constant values and raw 2118 * types.<br> 2119 * (not defined for Method and ForAll types) 2120 */ 2121 public boolean isAssignable(Type t, Type s, Warner warn) { 2122 if (t.hasTag(ERROR)) 2123 return true; 2124 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) { 2125 int value = ((Number)t.constValue()).intValue(); 2126 switch (s.getTag()) { 2127 case BYTE: 2128 if (Byte.MIN_VALUE <= value && value <= Byte.MAX_VALUE) 2129 return true; 2130 break; 2131 case CHAR: 2132 if (Character.MIN_VALUE <= value && value <= Character.MAX_VALUE) 2133 return true; 2134 break; 2135 case SHORT: 2136 if (Short.MIN_VALUE <= value && value <= Short.MAX_VALUE) 2137 return true; 2138 break; 2139 case INT: 2140 return true; 2141 case CLASS: 2142 switch (unboxedType(s).getTag()) { 2143 case BYTE: 2144 case CHAR: 2145 case SHORT: 2146 return isAssignable(t, unboxedType(s), warn); 2147 } 2148 break; 2149 } 2150 } 2151 return isConvertible(t, s, warn); 2152 } 2153 // </editor-fold> 2154 2155 // <editor-fold defaultstate="collapsed" desc="erasure"> 2156 /** 2157 * The erasure of t {@code |t|} -- the type that results when all 2158 * type parameters in t are deleted. 2159 */ 2160 public Type erasure(Type t) { 2161 return eraseNotNeeded(t)? t : erasure(t, false); 2162 } 2163 //where 2164 private boolean eraseNotNeeded(Type t) { 2165 // We don't want to erase primitive types and String type as that 2166 // operation is idempotent. Also, erasing these could result in loss 2167 // of information such as constant values attached to such types. 2168 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym); 2169 } 2170 2171 private Type erasure(Type t, boolean recurse) { 2172 if (t.isPrimitive()) { 2173 return t; /* fast special case */ 2174 } else { 2175 Type out = erasure.visit(t, recurse); 2176 return out; 2177 } 2178 } 2179 // where 2180 private SimpleVisitor<Type, Boolean> erasure = new SimpleVisitor<Type, Boolean>() { 2181 private Type combineMetadata(final Type ty, 2182 final TypeMetadata md) { 2183 if (!md.isEmpty()) { 2184 switch (ty.getKind()) { 2185 default: return ty.clone(ty.metadata.combine(md)); 2186 case OTHER: 2187 case UNION: 2188 case INTERSECTION: 2189 case PACKAGE: 2190 case EXECUTABLE: 2191 case NONE: 2192 case VOID: 2193 case ERROR: 2194 return ty; 2195 } 2196 } else { 2197 return ty; 2198 } 2199 } 2200 2201 public Type visitType(Type t, Boolean recurse) { 2202 if (t.isPrimitive()) 2203 return t; /*fast special case*/ 2204 else { 2205 Type erased = t.map(recurse ? erasureRecFun : erasureFun); 2206 return combineMetadata(erased, t.getMetadata()); 2207 } 2208 } 2209 2210 @Override 2211 public Type visitClassType(ClassType t, Boolean recurse) { 2212 Type erased = t.tsym.erasure(Types.this); 2213 if (recurse) { 2214 erased = new ErasedClassType(erased.getEnclosingType(),erased.tsym, t.getMetadata()); 2215 return erased; 2216 } else { 2217 return combineMetadata(erased, t.getMetadata()); 2218 } 2219 } 2220 2221 @Override 2222 public Type visitTypeVar(TypeVar t, Boolean recurse) { 2223 Type erased = erasure(t.bound, recurse); 2224 return combineMetadata(erased, t.getMetadata()); 2225 } 2226 2227 @Override 2228 public Type visitErrorType(ErrorType t, Boolean recurse) { 2229 return t; 2230 } 2231 }; 2232 2233 private Mapping erasureFun = new Mapping ("erasure") { 2234 public Type apply(Type t) { return erasure(t); } 2235 }; 2236 2237 private Mapping erasureRecFun = new Mapping ("erasureRecursive") { 2238 public Type apply(Type t) { return erasureRecursive(t); } 2239 }; 2240 2241 public List<Type> erasure(List<Type> ts) { 2242 return Type.map(ts, erasureFun); 2243 } 2244 2245 public Type erasureRecursive(Type t) { 2246 return erasure(t, true); 2247 } 2248 2249 public List<Type> erasureRecursive(List<Type> ts) { 2250 return Type.map(ts, erasureRecFun); 2251 } 2252 // </editor-fold> 2253 2254 // <editor-fold defaultstate="collapsed" desc="makeIntersectionType"> 2255 /** 2256 * Make an intersection type from non-empty list of types. The list should be ordered according to 2257 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. Note that this might cause a symbol completion. 2258 * Hence, this version of makeIntersectionType may not be called during a classfile read. 2259 * 2260 * @param bounds the types from which the intersection type is formed 2261 */ 2262 public IntersectionClassType makeIntersectionType(List<Type> bounds) { 2263 return makeIntersectionType(bounds, bounds.head.tsym.isInterface()); 2264 } 2265 2266 /** 2267 * Make an intersection type from non-empty list of types. The list should be ordered according to 2268 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. This does not cause symbol completion as 2269 * an extra parameter indicates as to whether all bounds are interfaces - in which case the 2270 * supertype is implicitly assumed to be 'Object'. 2271 * 2272 * @param bounds the types from which the intersection type is formed 2273 * @param allInterfaces are all bounds interface types? 2274 */ 2275 public IntersectionClassType makeIntersectionType(List<Type> bounds, boolean allInterfaces) { 2276 Assert.check(bounds.nonEmpty()); 2277 Type firstExplicitBound = bounds.head; 2278 if (allInterfaces) { 2279 bounds = bounds.prepend(syms.objectType); 2280 } 2281 ClassSymbol bc = 2282 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC, 2283 Type.moreInfo 2284 ? names.fromString(bounds.toString()) 2285 : names.empty, 2286 null, 2287 syms.noSymbol); 2288 IntersectionClassType intersectionType = new IntersectionClassType(bounds, bc, allInterfaces); 2289 bc.type = intersectionType; 2290 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ? 2291 syms.objectType : // error condition, recover 2292 erasure(firstExplicitBound); 2293 bc.members_field = WriteableScope.create(bc); 2294 return intersectionType; 2295 } 2296 // </editor-fold> 2297 2298 // <editor-fold defaultstate="collapsed" desc="supertype"> 2299 public Type supertype(Type t) { 2300 return supertype.visit(t); 2301 } 2302 // where 2303 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() { 2304 2305 public Type visitType(Type t, Void ignored) { 2306 // A note on wildcards: there is no good way to 2307 // determine a supertype for a super bounded wildcard. 2308 return Type.noType; 2309 } 2310 2311 @Override 2312 public Type visitClassType(ClassType t, Void ignored) { 2313 if (t.supertype_field == null) { 2314 Type supertype = ((ClassSymbol)t.tsym).getSuperclass(); 2315 // An interface has no superclass; its supertype is Object. 2316 if (t.isInterface()) 2317 supertype = ((ClassType)t.tsym.type).supertype_field; 2318 if (t.supertype_field == null) { 2319 List<Type> actuals = classBound(t).allparams(); 2320 List<Type> formals = t.tsym.type.allparams(); 2321 if (t.hasErasedSupertypes()) { 2322 t.supertype_field = erasureRecursive(supertype); 2323 } else if (formals.nonEmpty()) { 2324 t.supertype_field = subst(supertype, formals, actuals); 2325 } 2326 else { 2327 t.supertype_field = supertype; 2328 } 2329 } 2330 } 2331 return t.supertype_field; 2332 } 2333 2334 /** 2335 * The supertype is always a class type. If the type 2336 * variable's bounds start with a class type, this is also 2337 * the supertype. Otherwise, the supertype is 2338 * java.lang.Object. 2339 */ 2340 @Override 2341 public Type visitTypeVar(TypeVar t, Void ignored) { 2342 if (t.bound.hasTag(TYPEVAR) || 2343 (!t.bound.isCompound() && !t.bound.isInterface())) { 2344 return t.bound; 2345 } else { 2346 return supertype(t.bound); 2347 } 2348 } 2349 2350 @Override 2351 public Type visitArrayType(ArrayType t, Void ignored) { 2352 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType)) 2353 return arraySuperType(); 2354 else 2355 return new ArrayType(supertype(t.elemtype), t.tsym); 2356 } 2357 2358 @Override 2359 public Type visitErrorType(ErrorType t, Void ignored) { 2360 return Type.noType; 2361 } 2362 }; 2363 // </editor-fold> 2364 2365 // <editor-fold defaultstate="collapsed" desc="interfaces"> 2366 /** 2367 * Return the interfaces implemented by this class. 2368 */ 2369 public List<Type> interfaces(Type t) { 2370 return interfaces.visit(t); 2371 } 2372 // where 2373 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() { 2374 2375 public List<Type> visitType(Type t, Void ignored) { 2376 return List.nil(); 2377 } 2378 2379 @Override 2380 public List<Type> visitClassType(ClassType t, Void ignored) { 2381 if (t.interfaces_field == null) { 2382 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces(); 2383 if (t.interfaces_field == null) { 2384 // If t.interfaces_field is null, then t must 2385 // be a parameterized type (not to be confused 2386 // with a generic type declaration). 2387 // Terminology: 2388 // Parameterized type: List<String> 2389 // Generic type declaration: class List<E> { ... } 2390 // So t corresponds to List<String> and 2391 // t.tsym.type corresponds to List<E>. 2392 // The reason t must be parameterized type is 2393 // that completion will happen as a side 2394 // effect of calling 2395 // ClassSymbol.getInterfaces. Since 2396 // t.interfaces_field is null after 2397 // completion, we can assume that t is not the 2398 // type of a class/interface declaration. 2399 Assert.check(t != t.tsym.type, t); 2400 List<Type> actuals = t.allparams(); 2401 List<Type> formals = t.tsym.type.allparams(); 2402 if (t.hasErasedSupertypes()) { 2403 t.interfaces_field = erasureRecursive(interfaces); 2404 } else if (formals.nonEmpty()) { 2405 t.interfaces_field = subst(interfaces, formals, actuals); 2406 } 2407 else { 2408 t.interfaces_field = interfaces; 2409 } 2410 } 2411 } 2412 return t.interfaces_field; 2413 } 2414 2415 @Override 2416 public List<Type> visitTypeVar(TypeVar t, Void ignored) { 2417 if (t.bound.isCompound()) 2418 return interfaces(t.bound); 2419 2420 if (t.bound.isInterface()) 2421 return List.of(t.bound); 2422 2423 return List.nil(); 2424 } 2425 }; 2426 2427 public List<Type> directSupertypes(Type t) { 2428 return directSupertypes.visit(t); 2429 } 2430 // where 2431 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() { 2432 2433 public List<Type> visitType(final Type type, final Void ignored) { 2434 if (!type.isIntersection()) { 2435 final Type sup = supertype(type); 2436 return (sup == Type.noType || sup == type || sup == null) 2437 ? interfaces(type) 2438 : interfaces(type).prepend(sup); 2439 } else { 2440 return visitIntersectionType((IntersectionClassType) type); 2441 } 2442 } 2443 2444 private List<Type> visitIntersectionType(final IntersectionClassType it) { 2445 return it.getExplicitComponents(); 2446 } 2447 2448 }; 2449 2450 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) { 2451 for (Type i2 : interfaces(origin.type)) { 2452 if (isym == i2.tsym) return true; 2453 } 2454 return false; 2455 } 2456 // </editor-fold> 2457 2458 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw"> 2459 Map<Type,Boolean> isDerivedRawCache = new HashMap<>(); 2460 2461 public boolean isDerivedRaw(Type t) { 2462 Boolean result = isDerivedRawCache.get(t); 2463 if (result == null) { 2464 result = isDerivedRawInternal(t); 2465 isDerivedRawCache.put(t, result); 2466 } 2467 return result; 2468 } 2469 2470 public boolean isDerivedRawInternal(Type t) { 2471 if (t.isErroneous()) 2472 return false; 2473 return 2474 t.isRaw() || 2475 supertype(t) != Type.noType && isDerivedRaw(supertype(t)) || 2476 isDerivedRaw(interfaces(t)); 2477 } 2478 2479 public boolean isDerivedRaw(List<Type> ts) { 2480 List<Type> l = ts; 2481 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail; 2482 return l.nonEmpty(); 2483 } 2484 // </editor-fold> 2485 2486 // <editor-fold defaultstate="collapsed" desc="setBounds"> 2487 /** 2488 * Same as {@link Types#setBounds(TypeVar, List, boolean)}, except that third parameter is computed directly, 2489 * as follows: if all all bounds are interface types, the computed supertype is Object,otherwise 2490 * the supertype is simply left null (in this case, the supertype is assumed to be the head of 2491 * the bound list passed as second argument). Note that this check might cause a symbol completion. 2492 * Hence, this version of setBounds may not be called during a classfile read. 2493 * 2494 * @param t a type variable 2495 * @param bounds the bounds, must be nonempty 2496 */ 2497 public void setBounds(TypeVar t, List<Type> bounds) { 2498 setBounds(t, bounds, bounds.head.tsym.isInterface()); 2499 } 2500 2501 /** 2502 * Set the bounds field of the given type variable to reflect a (possibly multiple) list of bounds. 2503 * This does not cause symbol completion as an extra parameter indicates as to whether all bounds 2504 * are interfaces - in which case the supertype is implicitly assumed to be 'Object'. 2505 * 2506 * @param t a type variable 2507 * @param bounds the bounds, must be nonempty 2508 * @param allInterfaces are all bounds interface types? 2509 */ 2510 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) { 2511 t.bound = bounds.tail.isEmpty() ? 2512 bounds.head : 2513 makeIntersectionType(bounds, allInterfaces); 2514 t.rank_field = -1; 2515 } 2516 // </editor-fold> 2517 2518 // <editor-fold defaultstate="collapsed" desc="getBounds"> 2519 /** 2520 * Return list of bounds of the given type variable. 2521 */ 2522 public List<Type> getBounds(TypeVar t) { 2523 if (t.bound.hasTag(NONE)) 2524 return List.nil(); 2525 else if (t.bound.isErroneous() || !t.bound.isCompound()) 2526 return List.of(t.bound); 2527 else if ((erasure(t).tsym.flags() & INTERFACE) == 0) 2528 return interfaces(t).prepend(supertype(t)); 2529 else 2530 // No superclass was given in bounds. 2531 // In this case, supertype is Object, erasure is first interface. 2532 return interfaces(t); 2533 } 2534 // </editor-fold> 2535 2536 // <editor-fold defaultstate="collapsed" desc="classBound"> 2537 /** 2538 * If the given type is a (possibly selected) type variable, 2539 * return the bounding class of this type, otherwise return the 2540 * type itself. 2541 */ 2542 public Type classBound(Type t) { 2543 return classBound.visit(t); 2544 } 2545 // where 2546 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() { 2547 2548 public Type visitType(Type t, Void ignored) { 2549 return t; 2550 } 2551 2552 @Override 2553 public Type visitClassType(ClassType t, Void ignored) { 2554 Type outer1 = classBound(t.getEnclosingType()); 2555 if (outer1 != t.getEnclosingType()) 2556 return new ClassType(outer1, t.getTypeArguments(), t.tsym, 2557 t.getMetadata()); 2558 else 2559 return t; 2560 } 2561 2562 @Override 2563 public Type visitTypeVar(TypeVar t, Void ignored) { 2564 return classBound(supertype(t)); 2565 } 2566 2567 @Override 2568 public Type visitErrorType(ErrorType t, Void ignored) { 2569 return t; 2570 } 2571 }; 2572 // </editor-fold> 2573 2574 // <editor-fold defaultstate="collapsed" desc="sub signature / override equivalence"> 2575 /** 2576 * Returns true iff the first signature is a <em>sub 2577 * signature</em> of the other. This is <b>not</b> an equivalence 2578 * relation. 2579 * 2580 * @jls section 8.4.2. 2581 * @see #overrideEquivalent(Type t, Type s) 2582 * @param t first signature (possibly raw). 2583 * @param s second signature (could be subjected to erasure). 2584 * @return true if t is a sub signature of s. 2585 */ 2586 public boolean isSubSignature(Type t, Type s) { 2587 return isSubSignature(t, s, true); 2588 } 2589 2590 public boolean isSubSignature(Type t, Type s, boolean strict) { 2591 return hasSameArgs(t, s, strict) || hasSameArgs(t, erasure(s), strict); 2592 } 2593 2594 /** 2595 * Returns true iff these signatures are related by <em>override 2596 * equivalence</em>. This is the natural extension of 2597 * isSubSignature to an equivalence relation. 2598 * 2599 * @jls section 8.4.2. 2600 * @see #isSubSignature(Type t, Type s) 2601 * @param t a signature (possible raw, could be subjected to 2602 * erasure). 2603 * @param s a signature (possible raw, could be subjected to 2604 * erasure). 2605 * @return true if either argument is a sub signature of the other. 2606 */ 2607 public boolean overrideEquivalent(Type t, Type s) { 2608 return hasSameArgs(t, s) || 2609 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s); 2610 } 2611 2612 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) { 2613 for (Symbol sym : syms.objectType.tsym.members().getSymbolsByName(msym.name)) { 2614 if (msym.overrides(sym, origin, Types.this, true)) { 2615 return true; 2616 } 2617 } 2618 return false; 2619 } 2620 2621 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site"> 2622 class ImplementationCache { 2623 2624 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map = new WeakHashMap<>(); 2625 2626 class Entry { 2627 final MethodSymbol cachedImpl; 2628 final Filter<Symbol> implFilter; 2629 final boolean checkResult; 2630 final int prevMark; 2631 2632 public Entry(MethodSymbol cachedImpl, 2633 Filter<Symbol> scopeFilter, 2634 boolean checkResult, 2635 int prevMark) { 2636 this.cachedImpl = cachedImpl; 2637 this.implFilter = scopeFilter; 2638 this.checkResult = checkResult; 2639 this.prevMark = prevMark; 2640 } 2641 2642 boolean matches(Filter<Symbol> scopeFilter, boolean checkResult, int mark) { 2643 return this.implFilter == scopeFilter && 2644 this.checkResult == checkResult && 2645 this.prevMark == mark; 2646 } 2647 } 2648 2649 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) { 2650 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms); 2651 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null; 2652 if (cache == null) { 2653 cache = new HashMap<>(); 2654 _map.put(ms, new SoftReference<>(cache)); 2655 } 2656 Entry e = cache.get(origin); 2657 CompoundScope members = membersClosure(origin.type, true); 2658 if (e == null || 2659 !e.matches(implFilter, checkResult, members.getMark())) { 2660 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter); 2661 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark())); 2662 return impl; 2663 } 2664 else { 2665 return e.cachedImpl; 2666 } 2667 } 2668 2669 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) { 2670 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) { 2671 t = skipTypeVars(t, false); 2672 TypeSymbol c = t.tsym; 2673 Symbol bestSoFar = null; 2674 for (Symbol sym : c.members().getSymbolsByName(ms.name, implFilter)) { 2675 if (sym != null && sym.overrides(ms, origin, Types.this, checkResult)) { 2676 bestSoFar = sym; 2677 if ((sym.flags() & ABSTRACT) == 0) { 2678 //if concrete impl is found, exit immediately 2679 break; 2680 } 2681 } 2682 } 2683 if (bestSoFar != null) { 2684 //return either the (only) concrete implementation or the first abstract one 2685 return (MethodSymbol)bestSoFar; 2686 } 2687 } 2688 return null; 2689 } 2690 } 2691 2692 private ImplementationCache implCache = new ImplementationCache(); 2693 2694 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) { 2695 return implCache.get(ms, origin, checkResult, implFilter); 2696 } 2697 // </editor-fold> 2698 2699 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site"> 2700 class MembersClosureCache extends SimpleVisitor<CompoundScope, Boolean> { 2701 2702 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>(); 2703 2704 class Entry { 2705 final boolean skipInterfaces; 2706 final CompoundScope compoundScope; 2707 2708 public Entry(boolean skipInterfaces, CompoundScope compoundScope) { 2709 this.skipInterfaces = skipInterfaces; 2710 this.compoundScope = compoundScope; 2711 } 2712 2713 boolean matches(boolean skipInterfaces) { 2714 return this.skipInterfaces == skipInterfaces; 2715 } 2716 } 2717 2718 List<TypeSymbol> seenTypes = List.nil(); 2719 2720 /** members closure visitor methods **/ 2721 2722 public CompoundScope visitType(Type t, Boolean skipInterface) { 2723 return null; 2724 } 2725 2726 @Override 2727 public CompoundScope visitClassType(ClassType t, Boolean skipInterface) { 2728 if (seenTypes.contains(t.tsym)) { 2729 //this is possible when an interface is implemented in multiple 2730 //superclasses, or when a classs hierarchy is circular - in such 2731 //cases we don't need to recurse (empty scope is returned) 2732 return new CompoundScope(t.tsym); 2733 } 2734 try { 2735 seenTypes = seenTypes.prepend(t.tsym); 2736 ClassSymbol csym = (ClassSymbol)t.tsym; 2737 Entry e = _map.get(csym); 2738 if (e == null || !e.matches(skipInterface)) { 2739 CompoundScope membersClosure = new CompoundScope(csym); 2740 if (!skipInterface) { 2741 for (Type i : interfaces(t)) { 2742 membersClosure.prependSubScope(visit(i, skipInterface)); 2743 } 2744 } 2745 membersClosure.prependSubScope(visit(supertype(t), skipInterface)); 2746 membersClosure.prependSubScope(csym.members()); 2747 e = new Entry(skipInterface, membersClosure); 2748 _map.put(csym, e); 2749 } 2750 return e.compoundScope; 2751 } 2752 finally { 2753 seenTypes = seenTypes.tail; 2754 } 2755 } 2756 2757 @Override 2758 public CompoundScope visitTypeVar(TypeVar t, Boolean skipInterface) { 2759 return visit(t.getUpperBound(), skipInterface); 2760 } 2761 } 2762 2763 private MembersClosureCache membersCache = new MembersClosureCache(); 2764 2765 public CompoundScope membersClosure(Type site, boolean skipInterface) { 2766 return membersCache.visit(site, skipInterface); 2767 } 2768 // </editor-fold> 2769 2770 2771 /** Return first abstract member of class `sym'. 2772 */ 2773 public MethodSymbol firstUnimplementedAbstract(ClassSymbol sym) { 2774 try { 2775 return firstUnimplementedAbstractImpl(sym, sym); 2776 } catch (CompletionFailure ex) { 2777 chk.completionError(enter.getEnv(sym).tree.pos(), ex); 2778 return null; 2779 } 2780 } 2781 //where: 2782 private MethodSymbol firstUnimplementedAbstractImpl(ClassSymbol impl, ClassSymbol c) { 2783 MethodSymbol undef = null; 2784 // Do not bother to search in classes that are not abstract, 2785 // since they cannot have abstract members. 2786 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) { 2787 Scope s = c.members(); 2788 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) { 2789 if (sym.kind == MTH && 2790 (sym.flags() & (ABSTRACT|IPROXY|DEFAULT)) == ABSTRACT) { 2791 MethodSymbol absmeth = (MethodSymbol)sym; 2792 MethodSymbol implmeth = absmeth.implementation(impl, this, true); 2793 if (implmeth == null || implmeth == absmeth) { 2794 //look for default implementations 2795 if (allowDefaultMethods) { 2796 MethodSymbol prov = interfaceCandidates(impl.type, absmeth).head; 2797 if (prov != null && prov.overrides(absmeth, impl, this, true)) { 2798 implmeth = prov; 2799 } 2800 } 2801 } 2802 if (implmeth == null || implmeth == absmeth) { 2803 undef = absmeth; 2804 break; 2805 } 2806 } 2807 } 2808 if (undef == null) { 2809 Type st = supertype(c.type); 2810 if (st.hasTag(CLASS)) 2811 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)st.tsym); 2812 } 2813 for (List<Type> l = interfaces(c.type); 2814 undef == null && l.nonEmpty(); 2815 l = l.tail) { 2816 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)l.head.tsym); 2817 } 2818 } 2819 return undef; 2820 } 2821 2822 2823 //where 2824 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) { 2825 Filter<Symbol> filter = new MethodFilter(ms, site); 2826 List<MethodSymbol> candidates = List.nil(); 2827 for (Symbol s : membersClosure(site, false).getSymbols(filter)) { 2828 if (!site.tsym.isInterface() && !s.owner.isInterface()) { 2829 return List.of((MethodSymbol)s); 2830 } else if (!candidates.contains(s)) { 2831 candidates = candidates.prepend((MethodSymbol)s); 2832 } 2833 } 2834 return prune(candidates); 2835 } 2836 2837 public List<MethodSymbol> prune(List<MethodSymbol> methods) { 2838 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>(); 2839 for (MethodSymbol m1 : methods) { 2840 boolean isMin_m1 = true; 2841 for (MethodSymbol m2 : methods) { 2842 if (m1 == m2) continue; 2843 if (m2.owner != m1.owner && 2844 asSuper(m2.owner.type, m1.owner) != null) { 2845 isMin_m1 = false; 2846 break; 2847 } 2848 } 2849 if (isMin_m1) 2850 methodsMin.append(m1); 2851 } 2852 return methodsMin.toList(); 2853 } 2854 // where 2855 private class MethodFilter implements Filter<Symbol> { 2856 2857 Symbol msym; 2858 Type site; 2859 2860 MethodFilter(Symbol msym, Type site) { 2861 this.msym = msym; 2862 this.site = site; 2863 } 2864 2865 public boolean accepts(Symbol s) { 2866 return s.kind == MTH && 2867 s.name == msym.name && 2868 (s.flags() & SYNTHETIC) == 0 && 2869 s.isInheritedIn(site.tsym, Types.this) && 2870 overrideEquivalent(memberType(site, s), memberType(site, msym)); 2871 } 2872 } 2873 // </editor-fold> 2874 2875 /** 2876 * Does t have the same arguments as s? It is assumed that both 2877 * types are (possibly polymorphic) method types. Monomorphic 2878 * method types "have the same arguments", if their argument lists 2879 * are equal. Polymorphic method types "have the same arguments", 2880 * if they have the same arguments after renaming all type 2881 * variables of one to corresponding type variables in the other, 2882 * where correspondence is by position in the type parameter list. 2883 */ 2884 public boolean hasSameArgs(Type t, Type s) { 2885 return hasSameArgs(t, s, true); 2886 } 2887 2888 public boolean hasSameArgs(Type t, Type s, boolean strict) { 2889 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict); 2890 } 2891 2892 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) { 2893 return hasSameArgs.visit(t, s); 2894 } 2895 // where 2896 private class HasSameArgs extends TypeRelation { 2897 2898 boolean strict; 2899 2900 public HasSameArgs(boolean strict) { 2901 this.strict = strict; 2902 } 2903 2904 public Boolean visitType(Type t, Type s) { 2905 throw new AssertionError(); 2906 } 2907 2908 @Override 2909 public Boolean visitMethodType(MethodType t, Type s) { 2910 return s.hasTag(METHOD) 2911 && containsTypeEquivalent(t.argtypes, s.getParameterTypes()); 2912 } 2913 2914 @Override 2915 public Boolean visitForAll(ForAll t, Type s) { 2916 if (!s.hasTag(FORALL)) 2917 return strict ? false : visitMethodType(t.asMethodType(), s); 2918 2919 ForAll forAll = (ForAll)s; 2920 return hasSameBounds(t, forAll) 2921 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); 2922 } 2923 2924 @Override 2925 public Boolean visitErrorType(ErrorType t, Type s) { 2926 return false; 2927 } 2928 } 2929 2930 TypeRelation hasSameArgs_strict = new HasSameArgs(true); 2931 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false); 2932 2933 // </editor-fold> 2934 2935 // <editor-fold defaultstate="collapsed" desc="subst"> 2936 public List<Type> subst(List<Type> ts, 2937 List<Type> from, 2938 List<Type> to) { 2939 return new Subst(from, to).subst(ts); 2940 } 2941 2942 /** 2943 * Substitute all occurrences of a type in `from' with the 2944 * corresponding type in `to' in 't'. Match lists `from' and `to' 2945 * from the right: If lists have different length, discard leading 2946 * elements of the longer list. 2947 */ 2948 public Type subst(Type t, List<Type> from, List<Type> to) { 2949 return new Subst(from, to).subst(t); 2950 } 2951 2952 private class Subst extends UnaryVisitor<Type> { 2953 List<Type> from; 2954 List<Type> to; 2955 2956 public Subst(List<Type> from, List<Type> to) { 2957 int fromLength = from.length(); 2958 int toLength = to.length(); 2959 while (fromLength > toLength) { 2960 fromLength--; 2961 from = from.tail; 2962 } 2963 while (fromLength < toLength) { 2964 toLength--; 2965 to = to.tail; 2966 } 2967 this.from = from; 2968 this.to = to; 2969 } 2970 2971 Type subst(Type t) { 2972 if (from.tail == null) 2973 return t; 2974 else 2975 return visit(t); 2976 } 2977 2978 List<Type> subst(List<Type> ts) { 2979 if (from.tail == null) 2980 return ts; 2981 boolean wild = false; 2982 if (ts.nonEmpty() && from.nonEmpty()) { 2983 Type head1 = subst(ts.head); 2984 List<Type> tail1 = subst(ts.tail); 2985 if (head1 != ts.head || tail1 != ts.tail) 2986 return tail1.prepend(head1); 2987 } 2988 return ts; 2989 } 2990 2991 public Type visitType(Type t, Void ignored) { 2992 return t; 2993 } 2994 2995 @Override 2996 public Type visitMethodType(MethodType t, Void ignored) { 2997 List<Type> argtypes = subst(t.argtypes); 2998 Type restype = subst(t.restype); 2999 List<Type> thrown = subst(t.thrown); 3000 if (argtypes == t.argtypes && 3001 restype == t.restype && 3002 thrown == t.thrown) 3003 return t; 3004 else 3005 return new MethodType(argtypes, restype, thrown, t.tsym); 3006 } 3007 3008 @Override 3009 public Type visitTypeVar(TypeVar t, Void ignored) { 3010 for (List<Type> from = this.from, to = this.to; 3011 from.nonEmpty(); 3012 from = from.tail, to = to.tail) { 3013 if (t == from.head) { 3014 return to.head.withTypeVar(t); 3015 } 3016 } 3017 return t; 3018 } 3019 3020 @Override 3021 public Type visitUndetVar(UndetVar t, Void ignored) { 3022 //do nothing - we should not replace inside undet variables 3023 return t; 3024 } 3025 3026 @Override 3027 public Type visitClassType(ClassType t, Void ignored) { 3028 if (!t.isCompound()) { 3029 List<Type> typarams = t.getTypeArguments(); 3030 List<Type> typarams1 = subst(typarams); 3031 Type outer = t.getEnclosingType(); 3032 Type outer1 = subst(outer); 3033 if (typarams1 == typarams && outer1 == outer) 3034 return t; 3035 else 3036 return new ClassType(outer1, typarams1, t.tsym, 3037 t.getMetadata()); 3038 } else { 3039 Type st = subst(supertype(t)); 3040 List<Type> is = subst(interfaces(t)); 3041 if (st == supertype(t) && is == interfaces(t)) 3042 return t; 3043 else 3044 return makeIntersectionType(is.prepend(st)); 3045 } 3046 } 3047 3048 @Override 3049 public Type visitWildcardType(WildcardType t, Void ignored) { 3050 Type bound = t.type; 3051 if (t.kind != BoundKind.UNBOUND) 3052 bound = subst(bound); 3053 if (bound == t.type) { 3054 return t; 3055 } else { 3056 if (t.isExtendsBound() && bound.isExtendsBound()) 3057 bound = wildUpperBound(bound); 3058 return new WildcardType(bound, t.kind, syms.boundClass, 3059 t.bound, t.getMetadata()); 3060 } 3061 } 3062 3063 @Override 3064 public Type visitArrayType(ArrayType t, Void ignored) { 3065 Type elemtype = subst(t.elemtype); 3066 if (elemtype == t.elemtype) 3067 return t; 3068 else 3069 return new ArrayType(elemtype, t.tsym, t.getMetadata()); 3070 } 3071 3072 @Override 3073 public Type visitForAll(ForAll t, Void ignored) { 3074 if (Type.containsAny(to, t.tvars)) { 3075 //perform alpha-renaming of free-variables in 't' 3076 //if 'to' types contain variables that are free in 't' 3077 List<Type> freevars = newInstances(t.tvars); 3078 t = new ForAll(freevars, 3079 Types.this.subst(t.qtype, t.tvars, freevars)); 3080 } 3081 List<Type> tvars1 = substBounds(t.tvars, from, to); 3082 Type qtype1 = subst(t.qtype); 3083 if (tvars1 == t.tvars && qtype1 == t.qtype) { 3084 return t; 3085 } else if (tvars1 == t.tvars) { 3086 return new ForAll(tvars1, qtype1); 3087 } else { 3088 return new ForAll(tvars1, 3089 Types.this.subst(qtype1, t.tvars, tvars1)); 3090 } 3091 } 3092 3093 @Override 3094 public Type visitErrorType(ErrorType t, Void ignored) { 3095 return t; 3096 } 3097 } 3098 3099 public List<Type> substBounds(List<Type> tvars, 3100 List<Type> from, 3101 List<Type> to) { 3102 if (tvars.isEmpty()) 3103 return tvars; 3104 ListBuffer<Type> newBoundsBuf = new ListBuffer<>(); 3105 boolean changed = false; 3106 // calculate new bounds 3107 for (Type t : tvars) { 3108 TypeVar tv = (TypeVar) t; 3109 Type bound = subst(tv.bound, from, to); 3110 if (bound != tv.bound) 3111 changed = true; 3112 newBoundsBuf.append(bound); 3113 } 3114 if (!changed) 3115 return tvars; 3116 ListBuffer<Type> newTvars = new ListBuffer<>(); 3117 // create new type variables without bounds 3118 for (Type t : tvars) { 3119 newTvars.append(new TypeVar(t.tsym, null, syms.botType, 3120 t.getMetadata())); 3121 } 3122 // the new bounds should use the new type variables in place 3123 // of the old 3124 List<Type> newBounds = newBoundsBuf.toList(); 3125 from = tvars; 3126 to = newTvars.toList(); 3127 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) { 3128 newBounds.head = subst(newBounds.head, from, to); 3129 } 3130 newBounds = newBoundsBuf.toList(); 3131 // set the bounds of new type variables to the new bounds 3132 for (Type t : newTvars.toList()) { 3133 TypeVar tv = (TypeVar) t; 3134 tv.bound = newBounds.head; 3135 newBounds = newBounds.tail; 3136 } 3137 return newTvars.toList(); 3138 } 3139 3140 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) { 3141 Type bound1 = subst(t.bound, from, to); 3142 if (bound1 == t.bound) 3143 return t; 3144 else { 3145 // create new type variable without bounds 3146 TypeVar tv = new TypeVar(t.tsym, null, syms.botType, 3147 t.getMetadata()); 3148 // the new bound should use the new type variable in place 3149 // of the old 3150 tv.bound = subst(bound1, List.<Type>of(t), List.<Type>of(tv)); 3151 return tv; 3152 } 3153 } 3154 // </editor-fold> 3155 3156 // <editor-fold defaultstate="collapsed" desc="hasSameBounds"> 3157 /** 3158 * Does t have the same bounds for quantified variables as s? 3159 */ 3160 public boolean hasSameBounds(ForAll t, ForAll s) { 3161 List<Type> l1 = t.tvars; 3162 List<Type> l2 = s.tvars; 3163 while (l1.nonEmpty() && l2.nonEmpty() && 3164 isSameType(l1.head.getUpperBound(), 3165 subst(l2.head.getUpperBound(), 3166 s.tvars, 3167 t.tvars))) { 3168 l1 = l1.tail; 3169 l2 = l2.tail; 3170 } 3171 return l1.isEmpty() && l2.isEmpty(); 3172 } 3173 // </editor-fold> 3174 3175 // <editor-fold defaultstate="collapsed" desc="newInstances"> 3176 /** Create new vector of type variables from list of variables 3177 * changing all recursive bounds from old to new list. 3178 */ 3179 public List<Type> newInstances(List<Type> tvars) { 3180 List<Type> tvars1 = Type.map(tvars, newInstanceFun); 3181 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) { 3182 TypeVar tv = (TypeVar) l.head; 3183 tv.bound = subst(tv.bound, tvars, tvars1); 3184 } 3185 return tvars1; 3186 } 3187 private static final Mapping newInstanceFun = new Mapping("newInstanceFun") { 3188 public Type apply(Type t) { return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound(), t.getMetadata()); } 3189 }; 3190 // </editor-fold> 3191 3192 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) { 3193 return original.accept(methodWithParameters, newParams); 3194 } 3195 // where 3196 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() { 3197 public Type visitType(Type t, List<Type> newParams) { 3198 throw new IllegalArgumentException("Not a method type: " + t); 3199 } 3200 public Type visitMethodType(MethodType t, List<Type> newParams) { 3201 return new MethodType(newParams, t.restype, t.thrown, t.tsym); 3202 } 3203 public Type visitForAll(ForAll t, List<Type> newParams) { 3204 return new ForAll(t.tvars, t.qtype.accept(this, newParams)); 3205 } 3206 }; 3207 3208 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) { 3209 return original.accept(methodWithThrown, newThrown); 3210 } 3211 // where 3212 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() { 3213 public Type visitType(Type t, List<Type> newThrown) { 3214 throw new IllegalArgumentException("Not a method type: " + t); 3215 } 3216 public Type visitMethodType(MethodType t, List<Type> newThrown) { 3217 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym); 3218 } 3219 public Type visitForAll(ForAll t, List<Type> newThrown) { 3220 return new ForAll(t.tvars, t.qtype.accept(this, newThrown)); 3221 } 3222 }; 3223 3224 public Type createMethodTypeWithReturn(Type original, Type newReturn) { 3225 return original.accept(methodWithReturn, newReturn); 3226 } 3227 // where 3228 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() { 3229 public Type visitType(Type t, Type newReturn) { 3230 throw new IllegalArgumentException("Not a method type: " + t); 3231 } 3232 public Type visitMethodType(MethodType t, Type newReturn) { 3233 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym); 3234 } 3235 public Type visitForAll(ForAll t, Type newReturn) { 3236 return new ForAll(t.tvars, t.qtype.accept(this, newReturn)); 3237 } 3238 }; 3239 3240 // <editor-fold defaultstate="collapsed" desc="createErrorType"> 3241 public Type createErrorType(Type originalType) { 3242 return new ErrorType(originalType, syms.errSymbol); 3243 } 3244 3245 public Type createErrorType(ClassSymbol c, Type originalType) { 3246 return new ErrorType(c, originalType); 3247 } 3248 3249 public Type createErrorType(Name name, TypeSymbol container, Type originalType) { 3250 return new ErrorType(name, container, originalType); 3251 } 3252 // </editor-fold> 3253 3254 // <editor-fold defaultstate="collapsed" desc="rank"> 3255 /** 3256 * The rank of a class is the length of the longest path between 3257 * the class and java.lang.Object in the class inheritance 3258 * graph. Undefined for all but reference types. 3259 */ 3260 public int rank(Type t) { 3261 switch(t.getTag()) { 3262 case CLASS: { 3263 ClassType cls = (ClassType)t; 3264 if (cls.rank_field < 0) { 3265 Name fullname = cls.tsym.getQualifiedName(); 3266 if (fullname == names.java_lang_Object) 3267 cls.rank_field = 0; 3268 else { 3269 int r = rank(supertype(cls)); 3270 for (List<Type> l = interfaces(cls); 3271 l.nonEmpty(); 3272 l = l.tail) { 3273 if (rank(l.head) > r) 3274 r = rank(l.head); 3275 } 3276 cls.rank_field = r + 1; 3277 } 3278 } 3279 return cls.rank_field; 3280 } 3281 case TYPEVAR: { 3282 TypeVar tvar = (TypeVar)t; 3283 if (tvar.rank_field < 0) { 3284 int r = rank(supertype(tvar)); 3285 for (List<Type> l = interfaces(tvar); 3286 l.nonEmpty(); 3287 l = l.tail) { 3288 if (rank(l.head) > r) r = rank(l.head); 3289 } 3290 tvar.rank_field = r + 1; 3291 } 3292 return tvar.rank_field; 3293 } 3294 case ERROR: 3295 case NONE: 3296 return 0; 3297 default: 3298 throw new AssertionError(); 3299 } 3300 } 3301 // </editor-fold> 3302 3303 /** 3304 * Helper method for generating a string representation of a given type 3305 * accordingly to a given locale 3306 */ 3307 public String toString(Type t, Locale locale) { 3308 return Printer.createStandardPrinter(messages).visit(t, locale); 3309 } 3310 3311 /** 3312 * Helper method for generating a string representation of a given type 3313 * accordingly to a given locale 3314 */ 3315 public String toString(Symbol t, Locale locale) { 3316 return Printer.createStandardPrinter(messages).visit(t, locale); 3317 } 3318 3319 // <editor-fold defaultstate="collapsed" desc="toString"> 3320 /** 3321 * This toString is slightly more descriptive than the one on Type. 3322 * 3323 * @deprecated Types.toString(Type t, Locale l) provides better support 3324 * for localization 3325 */ 3326 @Deprecated 3327 public String toString(Type t) { 3328 if (t.hasTag(FORALL)) { 3329 ForAll forAll = (ForAll)t; 3330 return typaramsString(forAll.tvars) + forAll.qtype; 3331 } 3332 return "" + t; 3333 } 3334 // where 3335 private String typaramsString(List<Type> tvars) { 3336 StringBuilder s = new StringBuilder(); 3337 s.append('<'); 3338 boolean first = true; 3339 for (Type t : tvars) { 3340 if (!first) s.append(", "); 3341 first = false; 3342 appendTyparamString(((TypeVar)t), s); 3343 } 3344 s.append('>'); 3345 return s.toString(); 3346 } 3347 private void appendTyparamString(TypeVar t, StringBuilder buf) { 3348 buf.append(t); 3349 if (t.bound == null || 3350 t.bound.tsym.getQualifiedName() == names.java_lang_Object) 3351 return; 3352 buf.append(" extends "); // Java syntax; no need for i18n 3353 Type bound = t.bound; 3354 if (!bound.isCompound()) { 3355 buf.append(bound); 3356 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) { 3357 buf.append(supertype(t)); 3358 for (Type intf : interfaces(t)) { 3359 buf.append('&'); 3360 buf.append(intf); 3361 } 3362 } else { 3363 // No superclass was given in bounds. 3364 // In this case, supertype is Object, erasure is first interface. 3365 boolean first = true; 3366 for (Type intf : interfaces(t)) { 3367 if (!first) buf.append('&'); 3368 first = false; 3369 buf.append(intf); 3370 } 3371 } 3372 } 3373 // </editor-fold> 3374 3375 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types"> 3376 /** 3377 * A cache for closures. 3378 * 3379 * <p>A closure is a list of all the supertypes and interfaces of 3380 * a class or interface type, ordered by ClassSymbol.precedes 3381 * (that is, subclasses come first, arbitrary but fixed 3382 * otherwise). 3383 */ 3384 private Map<Type,List<Type>> closureCache = new HashMap<>(); 3385 3386 /** 3387 * Returns the closure of a class or interface type. 3388 */ 3389 public List<Type> closure(Type t) { 3390 List<Type> cl = closureCache.get(t); 3391 if (cl == null) { 3392 Type st = supertype(t); 3393 if (!t.isCompound()) { 3394 if (st.hasTag(CLASS)) { 3395 cl = insert(closure(st), t); 3396 } else if (st.hasTag(TYPEVAR)) { 3397 cl = closure(st).prepend(t); 3398 } else { 3399 cl = List.of(t); 3400 } 3401 } else { 3402 cl = closure(supertype(t)); 3403 } 3404 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) 3405 cl = union(cl, closure(l.head)); 3406 closureCache.put(t, cl); 3407 } 3408 return cl; 3409 } 3410 3411 /** 3412 * Insert a type in a closure 3413 */ 3414 public List<Type> insert(List<Type> cl, Type t) { 3415 if (cl.isEmpty()) { 3416 return cl.prepend(t); 3417 } else if (t.tsym == cl.head.tsym) { 3418 return cl; 3419 } else if (t.tsym.precedes(cl.head.tsym, this)) { 3420 return cl.prepend(t); 3421 } else { 3422 // t comes after head, or the two are unrelated 3423 return insert(cl.tail, t).prepend(cl.head); 3424 } 3425 } 3426 3427 /** 3428 * Form the union of two closures 3429 */ 3430 public List<Type> union(List<Type> cl1, List<Type> cl2) { 3431 if (cl1.isEmpty()) { 3432 return cl2; 3433 } else if (cl2.isEmpty()) { 3434 return cl1; 3435 } else if (cl1.head.tsym == cl2.head.tsym) { 3436 return union(cl1.tail, cl2.tail).prepend(cl1.head); 3437 } else if (cl1.head.tsym.precedes(cl2.head.tsym, this)) { 3438 return union(cl1.tail, cl2).prepend(cl1.head); 3439 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) { 3440 return union(cl1, cl2.tail).prepend(cl2.head); 3441 } else { 3442 // unrelated types 3443 return union(cl1.tail, cl2).prepend(cl1.head); 3444 } 3445 } 3446 3447 /** 3448 * Intersect two closures 3449 */ 3450 public List<Type> intersect(List<Type> cl1, List<Type> cl2) { 3451 if (cl1 == cl2) 3452 return cl1; 3453 if (cl1.isEmpty() || cl2.isEmpty()) 3454 return List.nil(); 3455 if (cl1.head.tsym.precedes(cl2.head.tsym, this)) 3456 return intersect(cl1.tail, cl2); 3457 if (cl2.head.tsym.precedes(cl1.head.tsym, this)) 3458 return intersect(cl1, cl2.tail); 3459 if (isSameType(cl1.head, cl2.head)) 3460 return intersect(cl1.tail, cl2.tail).prepend(cl1.head); 3461 if (cl1.head.tsym == cl2.head.tsym && 3462 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) { 3463 if (cl1.head.isParameterized() && cl2.head.isParameterized()) { 3464 Type merge = merge(cl1.head,cl2.head); 3465 return intersect(cl1.tail, cl2.tail).prepend(merge); 3466 } 3467 if (cl1.head.isRaw() || cl2.head.isRaw()) 3468 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head)); 3469 } 3470 return intersect(cl1.tail, cl2.tail); 3471 } 3472 // where 3473 class TypePair { 3474 final Type t1; 3475 final Type t2; 3476 boolean strict; 3477 3478 TypePair(Type t1, Type t2) { 3479 this(t1, t2, false); 3480 } 3481 3482 TypePair(Type t1, Type t2, boolean strict) { 3483 this.t1 = t1; 3484 this.t2 = t2; 3485 this.strict = strict; 3486 } 3487 @Override 3488 public int hashCode() { 3489 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2); 3490 } 3491 @Override 3492 public boolean equals(Object obj) { 3493 if (!(obj instanceof TypePair)) 3494 return false; 3495 TypePair typePair = (TypePair)obj; 3496 return isSameType(t1, typePair.t1, strict) 3497 && isSameType(t2, typePair.t2, strict); 3498 } 3499 } 3500 Set<TypePair> mergeCache = new HashSet<>(); 3501 private Type merge(Type c1, Type c2) { 3502 ClassType class1 = (ClassType) c1; 3503 List<Type> act1 = class1.getTypeArguments(); 3504 ClassType class2 = (ClassType) c2; 3505 List<Type> act2 = class2.getTypeArguments(); 3506 ListBuffer<Type> merged = new ListBuffer<>(); 3507 List<Type> typarams = class1.tsym.type.getTypeArguments(); 3508 3509 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) { 3510 if (containsType(act1.head, act2.head)) { 3511 merged.append(act1.head); 3512 } else if (containsType(act2.head, act1.head)) { 3513 merged.append(act2.head); 3514 } else { 3515 TypePair pair = new TypePair(c1, c2); 3516 Type m; 3517 if (mergeCache.add(pair)) { 3518 m = new WildcardType(lub(wildUpperBound(act1.head), 3519 wildUpperBound(act2.head)), 3520 BoundKind.EXTENDS, 3521 syms.boundClass); 3522 mergeCache.remove(pair); 3523 } else { 3524 m = new WildcardType(syms.objectType, 3525 BoundKind.UNBOUND, 3526 syms.boundClass); 3527 } 3528 merged.append(m.withTypeVar(typarams.head)); 3529 } 3530 act1 = act1.tail; 3531 act2 = act2.tail; 3532 typarams = typarams.tail; 3533 } 3534 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty()); 3535 // There is no spec detailing how type annotations are to 3536 // be inherited. So set it to noAnnotations for now 3537 return new ClassType(class1.getEnclosingType(), merged.toList(), 3538 class1.tsym); 3539 } 3540 3541 /** 3542 * Return the minimum type of a closure, a compound type if no 3543 * unique minimum exists. 3544 */ 3545 private Type compoundMin(List<Type> cl) { 3546 if (cl.isEmpty()) return syms.objectType; 3547 List<Type> compound = closureMin(cl); 3548 if (compound.isEmpty()) 3549 return null; 3550 else if (compound.tail.isEmpty()) 3551 return compound.head; 3552 else 3553 return makeIntersectionType(compound); 3554 } 3555 3556 /** 3557 * Return the minimum types of a closure, suitable for computing 3558 * compoundMin or glb. 3559 */ 3560 private List<Type> closureMin(List<Type> cl) { 3561 ListBuffer<Type> classes = new ListBuffer<>(); 3562 ListBuffer<Type> interfaces = new ListBuffer<>(); 3563 Set<Type> toSkip = new HashSet<>(); 3564 while (!cl.isEmpty()) { 3565 Type current = cl.head; 3566 boolean keep = !toSkip.contains(current); 3567 if (keep && current.hasTag(TYPEVAR)) { 3568 // skip lower-bounded variables with a subtype in cl.tail 3569 for (Type t : cl.tail) { 3570 if (isSubtypeNoCapture(t, current)) { 3571 keep = false; 3572 break; 3573 } 3574 } 3575 } 3576 if (keep) { 3577 if (current.isInterface()) 3578 interfaces.append(current); 3579 else 3580 classes.append(current); 3581 for (Type t : cl.tail) { 3582 // skip supertypes of 'current' in cl.tail 3583 if (isSubtypeNoCapture(current, t)) 3584 toSkip.add(t); 3585 } 3586 } 3587 cl = cl.tail; 3588 } 3589 return classes.appendList(interfaces).toList(); 3590 } 3591 3592 /** 3593 * Return the least upper bound of list of types. if the lub does 3594 * not exist return null. 3595 */ 3596 public Type lub(List<Type> ts) { 3597 return lub(ts.toArray(new Type[ts.length()])); 3598 } 3599 3600 /** 3601 * Return the least upper bound (lub) of set of types. If the lub 3602 * does not exist return the type of null (bottom). 3603 */ 3604 public Type lub(Type... ts) { 3605 final int UNKNOWN_BOUND = 0; 3606 final int ARRAY_BOUND = 1; 3607 final int CLASS_BOUND = 2; 3608 3609 int[] kinds = new int[ts.length]; 3610 3611 int boundkind = UNKNOWN_BOUND; 3612 for (int i = 0 ; i < ts.length ; i++) { 3613 Type t = ts[i]; 3614 switch (t.getTag()) { 3615 case CLASS: 3616 boundkind |= kinds[i] = CLASS_BOUND; 3617 break; 3618 case ARRAY: 3619 boundkind |= kinds[i] = ARRAY_BOUND; 3620 break; 3621 case TYPEVAR: 3622 do { 3623 t = t.getUpperBound(); 3624 } while (t.hasTag(TYPEVAR)); 3625 if (t.hasTag(ARRAY)) { 3626 boundkind |= kinds[i] = ARRAY_BOUND; 3627 } else { 3628 boundkind |= kinds[i] = CLASS_BOUND; 3629 } 3630 break; 3631 default: 3632 kinds[i] = UNKNOWN_BOUND; 3633 if (t.isPrimitive()) 3634 return syms.errType; 3635 } 3636 } 3637 switch (boundkind) { 3638 case 0: 3639 return syms.botType; 3640 3641 case ARRAY_BOUND: 3642 // calculate lub(A[], B[]) 3643 Type[] elements = new Type[ts.length]; 3644 for (int i = 0 ; i < ts.length ; i++) { 3645 Type elem = elements[i] = elemTypeFun.apply(ts[i]); 3646 if (elem.isPrimitive()) { 3647 // if a primitive type is found, then return 3648 // arraySuperType unless all the types are the 3649 // same 3650 Type first = ts[0]; 3651 for (int j = 1 ; j < ts.length ; j++) { 3652 if (!isSameType(first, ts[j])) { 3653 // lub(int[], B[]) is Cloneable & Serializable 3654 return arraySuperType(); 3655 } 3656 } 3657 // all the array types are the same, return one 3658 // lub(int[], int[]) is int[] 3659 return first; 3660 } 3661 } 3662 // lub(A[], B[]) is lub(A, B)[] 3663 return new ArrayType(lub(elements), syms.arrayClass); 3664 3665 case CLASS_BOUND: 3666 // calculate lub(A, B) 3667 int startIdx = 0; 3668 for (int i = 0; i < ts.length ; i++) { 3669 Type t = ts[i]; 3670 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) { 3671 break; 3672 } else { 3673 startIdx++; 3674 } 3675 } 3676 Assert.check(startIdx < ts.length); 3677 //step 1 - compute erased candidate set (EC) 3678 List<Type> cl = erasedSupertypes(ts[startIdx]); 3679 for (int i = startIdx + 1 ; i < ts.length ; i++) { 3680 Type t = ts[i]; 3681 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) 3682 cl = intersect(cl, erasedSupertypes(t)); 3683 } 3684 //step 2 - compute minimal erased candidate set (MEC) 3685 List<Type> mec = closureMin(cl); 3686 //step 3 - for each element G in MEC, compute lci(Inv(G)) 3687 List<Type> candidates = List.nil(); 3688 for (Type erasedSupertype : mec) { 3689 List<Type> lci = List.of(asSuper(ts[startIdx], erasedSupertype.tsym)); 3690 for (int i = startIdx + 1 ; i < ts.length ; i++) { 3691 Type superType = asSuper(ts[i], erasedSupertype.tsym); 3692 lci = intersect(lci, superType != null ? List.of(superType) : List.<Type>nil()); 3693 } 3694 candidates = candidates.appendList(lci); 3695 } 3696 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that 3697 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn)) 3698 return compoundMin(candidates); 3699 3700 default: 3701 // calculate lub(A, B[]) 3702 List<Type> classes = List.of(arraySuperType()); 3703 for (int i = 0 ; i < ts.length ; i++) { 3704 if (kinds[i] != ARRAY_BOUND) // Filter out any arrays 3705 classes = classes.prepend(ts[i]); 3706 } 3707 // lub(A, B[]) is lub(A, arraySuperType) 3708 return lub(classes); 3709 } 3710 } 3711 // where 3712 List<Type> erasedSupertypes(Type t) { 3713 ListBuffer<Type> buf = new ListBuffer<>(); 3714 for (Type sup : closure(t)) { 3715 if (sup.hasTag(TYPEVAR)) { 3716 buf.append(sup); 3717 } else { 3718 buf.append(erasure(sup)); 3719 } 3720 } 3721 return buf.toList(); 3722 } 3723 3724 private Type arraySuperType = null; 3725 private Type arraySuperType() { 3726 // initialized lazily to avoid problems during compiler startup 3727 if (arraySuperType == null) { 3728 synchronized (this) { 3729 if (arraySuperType == null) { 3730 // JLS 10.8: all arrays implement Cloneable and Serializable. 3731 arraySuperType = makeIntersectionType(List.of(syms.serializableType, 3732 syms.cloneableType), true); 3733 } 3734 } 3735 } 3736 return arraySuperType; 3737 } 3738 // </editor-fold> 3739 3740 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound"> 3741 public Type glb(List<Type> ts) { 3742 Type t1 = ts.head; 3743 for (Type t2 : ts.tail) { 3744 if (t1.isErroneous()) 3745 return t1; 3746 t1 = glb(t1, t2); 3747 } 3748 return t1; 3749 } 3750 //where 3751 public Type glb(Type t, Type s) { 3752 if (s == null) 3753 return t; 3754 else if (t.isPrimitive() || s.isPrimitive()) 3755 return syms.errType; 3756 else if (isSubtypeNoCapture(t, s)) 3757 return t; 3758 else if (isSubtypeNoCapture(s, t)) 3759 return s; 3760 3761 List<Type> closure = union(closure(t), closure(s)); 3762 return glbFlattened(closure, t); 3763 } 3764 //where 3765 /** 3766 * Perform glb for a list of non-primitive, non-error, non-compound types; 3767 * redundant elements are removed. Bounds should be ordered according to 3768 * {@link Symbol#precedes(TypeSymbol,Types)}. 3769 * 3770 * @param flatBounds List of type to glb 3771 * @param errT Original type to use if the result is an error type 3772 */ 3773 private Type glbFlattened(List<Type> flatBounds, Type errT) { 3774 List<Type> bounds = closureMin(flatBounds); 3775 3776 if (bounds.isEmpty()) { // length == 0 3777 return syms.objectType; 3778 } else if (bounds.tail.isEmpty()) { // length == 1 3779 return bounds.head; 3780 } else { // length > 1 3781 int classCount = 0; 3782 List<Type> lowers = List.nil(); 3783 for (Type bound : bounds) { 3784 if (!bound.isInterface()) { 3785 classCount++; 3786 Type lower = cvarLowerBound(bound); 3787 if (bound != lower && !lower.hasTag(BOT)) 3788 lowers = insert(lowers, lower); 3789 } 3790 } 3791 if (classCount > 1) { 3792 if (lowers.isEmpty()) 3793 return createErrorType(errT); 3794 else 3795 return glbFlattened(union(bounds, lowers), errT); 3796 } 3797 } 3798 return makeIntersectionType(bounds); 3799 } 3800 // </editor-fold> 3801 3802 // <editor-fold defaultstate="collapsed" desc="hashCode"> 3803 /** 3804 * Compute a hash code on a type. 3805 */ 3806 public int hashCode(Type t) { 3807 return hashCode.visit(t); 3808 } 3809 // where 3810 private static final UnaryVisitor<Integer> hashCode = new UnaryVisitor<Integer>() { 3811 3812 public Integer visitType(Type t, Void ignored) { 3813 return t.getTag().ordinal(); 3814 } 3815 3816 @Override 3817 public Integer visitClassType(ClassType t, Void ignored) { 3818 int result = visit(t.getEnclosingType()); 3819 result *= 127; 3820 result += t.tsym.flatName().hashCode(); 3821 for (Type s : t.getTypeArguments()) { 3822 result *= 127; 3823 result += visit(s); 3824 } 3825 return result; 3826 } 3827 3828 @Override 3829 public Integer visitMethodType(MethodType t, Void ignored) { 3830 int h = METHOD.ordinal(); 3831 for (List<Type> thisargs = t.argtypes; 3832 thisargs.tail != null; 3833 thisargs = thisargs.tail) 3834 h = (h << 5) + visit(thisargs.head); 3835 return (h << 5) + visit(t.restype); 3836 } 3837 3838 @Override 3839 public Integer visitWildcardType(WildcardType t, Void ignored) { 3840 int result = t.kind.hashCode(); 3841 if (t.type != null) { 3842 result *= 127; 3843 result += visit(t.type); 3844 } 3845 return result; 3846 } 3847 3848 @Override 3849 public Integer visitArrayType(ArrayType t, Void ignored) { 3850 return visit(t.elemtype) + 12; 3851 } 3852 3853 @Override 3854 public Integer visitTypeVar(TypeVar t, Void ignored) { 3855 return System.identityHashCode(t.tsym); 3856 } 3857 3858 @Override 3859 public Integer visitUndetVar(UndetVar t, Void ignored) { 3860 return System.identityHashCode(t); 3861 } 3862 3863 @Override 3864 public Integer visitErrorType(ErrorType t, Void ignored) { 3865 return 0; 3866 } 3867 }; 3868 // </editor-fold> 3869 3870 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable"> 3871 /** 3872 * Does t have a result that is a subtype of the result type of s, 3873 * suitable for covariant returns? It is assumed that both types 3874 * are (possibly polymorphic) method types. Monomorphic method 3875 * types are handled in the obvious way. Polymorphic method types 3876 * require renaming all type variables of one to corresponding 3877 * type variables in the other, where correspondence is by 3878 * position in the type parameter list. */ 3879 public boolean resultSubtype(Type t, Type s, Warner warner) { 3880 List<Type> tvars = t.getTypeArguments(); 3881 List<Type> svars = s.getTypeArguments(); 3882 Type tres = t.getReturnType(); 3883 Type sres = subst(s.getReturnType(), svars, tvars); 3884 return covariantReturnType(tres, sres, warner); 3885 } 3886 3887 /** 3888 * Return-Type-Substitutable. 3889 * @jls section 8.4.5 3890 */ 3891 public boolean returnTypeSubstitutable(Type r1, Type r2) { 3892 if (hasSameArgs(r1, r2)) 3893 return resultSubtype(r1, r2, noWarnings); 3894 else 3895 return covariantReturnType(r1.getReturnType(), 3896 erasure(r2.getReturnType()), 3897 noWarnings); 3898 } 3899 3900 public boolean returnTypeSubstitutable(Type r1, 3901 Type r2, Type r2res, 3902 Warner warner) { 3903 if (isSameType(r1.getReturnType(), r2res)) 3904 return true; 3905 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive()) 3906 return false; 3907 3908 if (hasSameArgs(r1, r2)) 3909 return covariantReturnType(r1.getReturnType(), r2res, warner); 3910 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner)) 3911 return true; 3912 if (!isSubtype(r1.getReturnType(), erasure(r2res))) 3913 return false; 3914 warner.warn(LintCategory.UNCHECKED); 3915 return true; 3916 } 3917 3918 /** 3919 * Is t an appropriate return type in an overrider for a 3920 * method that returns s? 3921 */ 3922 public boolean covariantReturnType(Type t, Type s, Warner warner) { 3923 return 3924 isSameType(t, s) || 3925 !t.isPrimitive() && 3926 !s.isPrimitive() && 3927 isAssignable(t, s, warner); 3928 } 3929 // </editor-fold> 3930 3931 // <editor-fold defaultstate="collapsed" desc="Box/unbox support"> 3932 /** 3933 * Return the class that boxes the given primitive. 3934 */ 3935 public ClassSymbol boxedClass(Type t) { 3936 return syms.enterClass(syms.boxedName[t.getTag().ordinal()]); 3937 } 3938 3939 /** 3940 * Return the boxed type if 't' is primitive, otherwise return 't' itself. 3941 */ 3942 public Type boxedTypeOrType(Type t) { 3943 return t.isPrimitive() ? 3944 boxedClass(t).type : 3945 t; 3946 } 3947 3948 /** 3949 * Return the primitive type corresponding to a boxed type. 3950 */ 3951 public Type unboxedType(Type t) { 3952 for (int i=0; i<syms.boxedName.length; i++) { 3953 Name box = syms.boxedName[i]; 3954 if (box != null && 3955 asSuper(t, syms.enterClass(box)) != null) 3956 return syms.typeOfTag[i]; 3957 } 3958 return Type.noType; 3959 } 3960 3961 /** 3962 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself. 3963 */ 3964 public Type unboxedTypeOrType(Type t) { 3965 Type unboxedType = unboxedType(t); 3966 return unboxedType.hasTag(NONE) ? t : unboxedType; 3967 } 3968 // </editor-fold> 3969 3970 // <editor-fold defaultstate="collapsed" desc="Capture conversion"> 3971 /* 3972 * JLS 5.1.10 Capture Conversion: 3973 * 3974 * Let G name a generic type declaration with n formal type 3975 * parameters A1 ... An with corresponding bounds U1 ... Un. There 3976 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>, 3977 * where, for 1 <= i <= n: 3978 * 3979 * + If Ti is a wildcard type argument (4.5.1) of the form ? then 3980 * Si is a fresh type variable whose upper bound is 3981 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null 3982 * type. 3983 * 3984 * + If Ti is a wildcard type argument of the form ? extends Bi, 3985 * then Si is a fresh type variable whose upper bound is 3986 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is 3987 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is 3988 * a compile-time error if for any two classes (not interfaces) 3989 * Vi and Vj,Vi is not a subclass of Vj or vice versa. 3990 * 3991 * + If Ti is a wildcard type argument of the form ? super Bi, 3992 * then Si is a fresh type variable whose upper bound is 3993 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi. 3994 * 3995 * + Otherwise, Si = Ti. 3996 * 3997 * Capture conversion on any type other than a parameterized type 3998 * (4.5) acts as an identity conversion (5.1.1). Capture 3999 * conversions never require a special action at run time and 4000 * therefore never throw an exception at run time. 4001 * 4002 * Capture conversion is not applied recursively. 4003 */ 4004 /** 4005 * Capture conversion as specified by the JLS. 4006 */ 4007 4008 public List<Type> capture(List<Type> ts) { 4009 List<Type> buf = List.nil(); 4010 for (Type t : ts) { 4011 buf = buf.prepend(capture(t)); 4012 } 4013 return buf.reverse(); 4014 } 4015 4016 public Type capture(Type t) { 4017 if (!t.hasTag(CLASS)) { 4018 return t; 4019 } 4020 if (t.getEnclosingType() != Type.noType) { 4021 Type capturedEncl = capture(t.getEnclosingType()); 4022 if (capturedEncl != t.getEnclosingType()) { 4023 Type type1 = memberType(capturedEncl, t.tsym); 4024 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments()); 4025 } 4026 } 4027 ClassType cls = (ClassType)t; 4028 if (cls.isRaw() || !cls.isParameterized()) 4029 return cls; 4030 4031 ClassType G = (ClassType)cls.asElement().asType(); 4032 List<Type> A = G.getTypeArguments(); 4033 List<Type> T = cls.getTypeArguments(); 4034 List<Type> S = freshTypeVariables(T); 4035 4036 List<Type> currentA = A; 4037 List<Type> currentT = T; 4038 List<Type> currentS = S; 4039 boolean captured = false; 4040 while (!currentA.isEmpty() && 4041 !currentT.isEmpty() && 4042 !currentS.isEmpty()) { 4043 if (currentS.head != currentT.head) { 4044 captured = true; 4045 WildcardType Ti = (WildcardType)currentT.head; 4046 Type Ui = currentA.head.getUpperBound(); 4047 CapturedType Si = (CapturedType)currentS.head; 4048 if (Ui == null) 4049 Ui = syms.objectType; 4050 switch (Ti.kind) { 4051 case UNBOUND: 4052 Si.bound = subst(Ui, A, S); 4053 Si.lower = syms.botType; 4054 break; 4055 case EXTENDS: 4056 Si.bound = glb(Ti.getExtendsBound(), subst(Ui, A, S)); 4057 Si.lower = syms.botType; 4058 break; 4059 case SUPER: 4060 Si.bound = subst(Ui, A, S); 4061 Si.lower = Ti.getSuperBound(); 4062 break; 4063 } 4064 Type tmpBound = Si.bound.hasTag(UNDETVAR) ? ((UndetVar)Si.bound).qtype : Si.bound; 4065 Type tmpLower = Si.lower.hasTag(UNDETVAR) ? ((UndetVar)Si.lower).qtype : Si.lower; 4066 if (!Si.bound.hasTag(ERROR) && 4067 !Si.lower.hasTag(ERROR) && 4068 isSameType(tmpBound, tmpLower, false)) { 4069 currentS.head = Si.bound; 4070 } 4071 } 4072 currentA = currentA.tail; 4073 currentT = currentT.tail; 4074 currentS = currentS.tail; 4075 } 4076 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty()) 4077 return erasure(t); // some "rare" type involved 4078 4079 if (captured) 4080 return new ClassType(cls.getEnclosingType(), S, cls.tsym, 4081 cls.getMetadata()); 4082 else 4083 return t; 4084 } 4085 // where 4086 public List<Type> freshTypeVariables(List<Type> types) { 4087 ListBuffer<Type> result = new ListBuffer<>(); 4088 for (Type t : types) { 4089 if (t.hasTag(WILDCARD)) { 4090 Type bound = ((WildcardType)t).getExtendsBound(); 4091 if (bound == null) 4092 bound = syms.objectType; 4093 result.append(new CapturedType(capturedName, 4094 syms.noSymbol, 4095 bound, 4096 syms.botType, 4097 (WildcardType)t)); 4098 } else { 4099 result.append(t); 4100 } 4101 } 4102 return result.toList(); 4103 } 4104 // </editor-fold> 4105 4106 // <editor-fold defaultstate="collapsed" desc="Internal utility methods"> 4107 private boolean sideCast(Type from, Type to, Warner warn) { 4108 // We are casting from type $from$ to type $to$, which are 4109 // non-final unrelated types. This method 4110 // tries to reject a cast by transferring type parameters 4111 // from $to$ to $from$ by common superinterfaces. 4112 boolean reverse = false; 4113 Type target = to; 4114 if ((to.tsym.flags() & INTERFACE) == 0) { 4115 Assert.check((from.tsym.flags() & INTERFACE) != 0); 4116 reverse = true; 4117 to = from; 4118 from = target; 4119 } 4120 List<Type> commonSupers = superClosure(to, erasure(from)); 4121 boolean giveWarning = commonSupers.isEmpty(); 4122 // The arguments to the supers could be unified here to 4123 // get a more accurate analysis 4124 while (commonSupers.nonEmpty()) { 4125 Type t1 = asSuper(from, commonSupers.head.tsym); 4126 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym); 4127 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) 4128 return false; 4129 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)); 4130 commonSupers = commonSupers.tail; 4131 } 4132 if (giveWarning && !isReifiable(reverse ? from : to)) 4133 warn.warn(LintCategory.UNCHECKED); 4134 return true; 4135 } 4136 4137 private boolean sideCastFinal(Type from, Type to, Warner warn) { 4138 // We are casting from type $from$ to type $to$, which are 4139 // unrelated types one of which is final and the other of 4140 // which is an interface. This method 4141 // tries to reject a cast by transferring type parameters 4142 // from the final class to the interface. 4143 boolean reverse = false; 4144 Type target = to; 4145 if ((to.tsym.flags() & INTERFACE) == 0) { 4146 Assert.check((from.tsym.flags() & INTERFACE) != 0); 4147 reverse = true; 4148 to = from; 4149 from = target; 4150 } 4151 Assert.check((from.tsym.flags() & FINAL) != 0); 4152 Type t1 = asSuper(from, to.tsym); 4153 if (t1 == null) return false; 4154 Type t2 = to; 4155 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) 4156 return false; 4157 if (!isReifiable(target) && 4158 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2))) 4159 warn.warn(LintCategory.UNCHECKED); 4160 return true; 4161 } 4162 4163 private boolean giveWarning(Type from, Type to) { 4164 List<Type> bounds = to.isCompound() ? 4165 ((IntersectionClassType)to).getComponents() : List.of(to); 4166 for (Type b : bounds) { 4167 Type subFrom = asSub(from, b.tsym); 4168 if (b.isParameterized() && 4169 (!(isUnbounded(b) || 4170 isSubtype(from, b) || 4171 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) { 4172 return true; 4173 } 4174 } 4175 return false; 4176 } 4177 4178 private List<Type> superClosure(Type t, Type s) { 4179 List<Type> cl = List.nil(); 4180 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { 4181 if (isSubtype(s, erasure(l.head))) { 4182 cl = insert(cl, l.head); 4183 } else { 4184 cl = union(cl, superClosure(l.head, s)); 4185 } 4186 } 4187 return cl; 4188 } 4189 4190 private boolean containsTypeEquivalent(Type t, Type s) { 4191 return 4192 isSameType(t, s) || // shortcut 4193 containsType(t, s) && containsType(s, t); 4194 } 4195 4196 // <editor-fold defaultstate="collapsed" desc="adapt"> 4197 /** 4198 * Adapt a type by computing a substitution which maps a source 4199 * type to a target type. 4200 * 4201 * @param source the source type 4202 * @param target the target type 4203 * @param from the type variables of the computed substitution 4204 * @param to the types of the computed substitution. 4205 */ 4206 public void adapt(Type source, 4207 Type target, 4208 ListBuffer<Type> from, 4209 ListBuffer<Type> to) throws AdaptFailure { 4210 new Adapter(from, to).adapt(source, target); 4211 } 4212 4213 class Adapter extends SimpleVisitor<Void, Type> { 4214 4215 ListBuffer<Type> from; 4216 ListBuffer<Type> to; 4217 Map<Symbol,Type> mapping; 4218 4219 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) { 4220 this.from = from; 4221 this.to = to; 4222 mapping = new HashMap<>(); 4223 } 4224 4225 public void adapt(Type source, Type target) throws AdaptFailure { 4226 visit(source, target); 4227 List<Type> fromList = from.toList(); 4228 List<Type> toList = to.toList(); 4229 while (!fromList.isEmpty()) { 4230 Type val = mapping.get(fromList.head.tsym); 4231 if (toList.head != val) 4232 toList.head = val; 4233 fromList = fromList.tail; 4234 toList = toList.tail; 4235 } 4236 } 4237 4238 @Override 4239 public Void visitClassType(ClassType source, Type target) throws AdaptFailure { 4240 if (target.hasTag(CLASS)) 4241 adaptRecursive(source.allparams(), target.allparams()); 4242 return null; 4243 } 4244 4245 @Override 4246 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure { 4247 if (target.hasTag(ARRAY)) 4248 adaptRecursive(elemtype(source), elemtype(target)); 4249 return null; 4250 } 4251 4252 @Override 4253 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure { 4254 if (source.isExtendsBound()) 4255 adaptRecursive(wildUpperBound(source), wildUpperBound(target)); 4256 else if (source.isSuperBound()) 4257 adaptRecursive(wildLowerBound(source), wildLowerBound(target)); 4258 return null; 4259 } 4260 4261 @Override 4262 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure { 4263 // Check to see if there is 4264 // already a mapping for $source$, in which case 4265 // the old mapping will be merged with the new 4266 Type val = mapping.get(source.tsym); 4267 if (val != null) { 4268 if (val.isSuperBound() && target.isSuperBound()) { 4269 val = isSubtype(wildLowerBound(val), wildLowerBound(target)) 4270 ? target : val; 4271 } else if (val.isExtendsBound() && target.isExtendsBound()) { 4272 val = isSubtype(wildUpperBound(val), wildUpperBound(target)) 4273 ? val : target; 4274 } else if (!isSameType(val, target)) { 4275 throw new AdaptFailure(); 4276 } 4277 } else { 4278 val = target; 4279 from.append(source); 4280 to.append(target); 4281 } 4282 mapping.put(source.tsym, val); 4283 return null; 4284 } 4285 4286 @Override 4287 public Void visitType(Type source, Type target) { 4288 return null; 4289 } 4290 4291 private Set<TypePair> cache = new HashSet<>(); 4292 4293 private void adaptRecursive(Type source, Type target) { 4294 TypePair pair = new TypePair(source, target); 4295 if (cache.add(pair)) { 4296 try { 4297 visit(source, target); 4298 } finally { 4299 cache.remove(pair); 4300 } 4301 } 4302 } 4303 4304 private void adaptRecursive(List<Type> source, List<Type> target) { 4305 if (source.length() == target.length()) { 4306 while (source.nonEmpty()) { 4307 adaptRecursive(source.head, target.head); 4308 source = source.tail; 4309 target = target.tail; 4310 } 4311 } 4312 } 4313 } 4314 4315 public static class AdaptFailure extends RuntimeException { 4316 static final long serialVersionUID = -7490231548272701566L; 4317 } 4318 4319 private void adaptSelf(Type t, 4320 ListBuffer<Type> from, 4321 ListBuffer<Type> to) { 4322 try { 4323 //if (t.tsym.type != t) 4324 adapt(t.tsym.type, t, from, to); 4325 } catch (AdaptFailure ex) { 4326 // Adapt should never fail calculating a mapping from 4327 // t.tsym.type to t as there can be no merge problem. 4328 throw new AssertionError(ex); 4329 } 4330 } 4331 // </editor-fold> 4332 4333 /** 4334 * Rewrite all type variables (universal quantifiers) in the given 4335 * type to wildcards (existential quantifiers). This is used to 4336 * determine if a cast is allowed. For example, if high is true 4337 * and {@code T <: Number}, then {@code List<T>} is rewritten to 4338 * {@code List<? extends Number>}. Since {@code List<Integer> <: 4339 * List<? extends Number>} a {@code List<T>} can be cast to {@code 4340 * List<Integer>} with a warning. 4341 * @param t a type 4342 * @param high if true return an upper bound; otherwise a lower 4343 * bound 4344 * @param rewriteTypeVars only rewrite captured wildcards if false; 4345 * otherwise rewrite all type variables 4346 * @return the type rewritten with wildcards (existential 4347 * quantifiers) only 4348 */ 4349 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) { 4350 return new Rewriter(high, rewriteTypeVars).visit(t); 4351 } 4352 4353 class Rewriter extends UnaryVisitor<Type> { 4354 4355 boolean high; 4356 boolean rewriteTypeVars; 4357 4358 Rewriter(boolean high, boolean rewriteTypeVars) { 4359 this.high = high; 4360 this.rewriteTypeVars = rewriteTypeVars; 4361 } 4362 4363 @Override 4364 public Type visitClassType(ClassType t, Void s) { 4365 ListBuffer<Type> rewritten = new ListBuffer<>(); 4366 boolean changed = false; 4367 for (Type arg : t.allparams()) { 4368 Type bound = visit(arg); 4369 if (arg != bound) { 4370 changed = true; 4371 } 4372 rewritten.append(bound); 4373 } 4374 if (changed) 4375 return subst(t.tsym.type, 4376 t.tsym.type.allparams(), 4377 rewritten.toList()); 4378 else 4379 return t; 4380 } 4381 4382 public Type visitType(Type t, Void s) { 4383 return t; 4384 } 4385 4386 @Override 4387 public Type visitCapturedType(CapturedType t, Void s) { 4388 Type w_bound = t.wildcard.type; 4389 Type bound = w_bound.contains(t) ? 4390 erasure(w_bound) : 4391 visit(w_bound); 4392 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind); 4393 } 4394 4395 @Override 4396 public Type visitTypeVar(TypeVar t, Void s) { 4397 if (rewriteTypeVars) { 4398 Type bound = t.bound.contains(t) ? 4399 erasure(t.bound) : 4400 visit(t.bound); 4401 return rewriteAsWildcardType(bound, t, EXTENDS); 4402 } else { 4403 return t; 4404 } 4405 } 4406 4407 @Override 4408 public Type visitWildcardType(WildcardType t, Void s) { 4409 Type bound2 = visit(t.type); 4410 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind); 4411 } 4412 4413 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) { 4414 switch (bk) { 4415 case EXTENDS: return high ? 4416 makeExtendsWildcard(B(bound), formal) : 4417 makeExtendsWildcard(syms.objectType, formal); 4418 case SUPER: return high ? 4419 makeSuperWildcard(syms.botType, formal) : 4420 makeSuperWildcard(B(bound), formal); 4421 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal); 4422 default: 4423 Assert.error("Invalid bound kind " + bk); 4424 return null; 4425 } 4426 } 4427 4428 Type B(Type t) { 4429 while (t.hasTag(WILDCARD)) { 4430 WildcardType w = (WildcardType)t; 4431 t = high ? 4432 w.getExtendsBound() : 4433 w.getSuperBound(); 4434 if (t == null) { 4435 t = high ? syms.objectType : syms.botType; 4436 } 4437 } 4438 return t; 4439 } 4440 } 4441 4442 4443 /** 4444 * Create a wildcard with the given upper (extends) bound; create 4445 * an unbounded wildcard if bound is Object. 4446 * 4447 * @param bound the upper bound 4448 * @param formal the formal type parameter that will be 4449 * substituted by the wildcard 4450 */ 4451 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) { 4452 if (bound == syms.objectType) { 4453 return new WildcardType(syms.objectType, 4454 BoundKind.UNBOUND, 4455 syms.boundClass, 4456 formal); 4457 } else { 4458 return new WildcardType(bound, 4459 BoundKind.EXTENDS, 4460 syms.boundClass, 4461 formal); 4462 } 4463 } 4464 4465 /** 4466 * Create a wildcard with the given lower (super) bound; create an 4467 * unbounded wildcard if bound is bottom (type of {@code null}). 4468 * 4469 * @param bound the lower bound 4470 * @param formal the formal type parameter that will be 4471 * substituted by the wildcard 4472 */ 4473 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) { 4474 if (bound.hasTag(BOT)) { 4475 return new WildcardType(syms.objectType, 4476 BoundKind.UNBOUND, 4477 syms.boundClass, 4478 formal); 4479 } else { 4480 return new WildcardType(bound, 4481 BoundKind.SUPER, 4482 syms.boundClass, 4483 formal); 4484 } 4485 } 4486 4487 /** 4488 * A wrapper for a type that allows use in sets. 4489 */ 4490 public static class UniqueType { 4491 public final Type type; 4492 final Types types; 4493 4494 public UniqueType(Type type, Types types) { 4495 this.type = type; 4496 this.types = types; 4497 } 4498 4499 public int hashCode() { 4500 return types.hashCode(type); 4501 } 4502 4503 public boolean equals(Object obj) { 4504 return (obj instanceof UniqueType) && 4505 types.isSameType(type, ((UniqueType)obj).type); 4506 } 4507 4508 public String toString() { 4509 return type.toString(); 4510 } 4511 4512 } 4513 // </editor-fold> 4514 4515 // <editor-fold defaultstate="collapsed" desc="Visitors"> 4516 /** 4517 * A default visitor for types. All visitor methods except 4518 * visitType are implemented by delegating to visitType. Concrete 4519 * subclasses must provide an implementation of visitType and can 4520 * override other methods as needed. 4521 * 4522 * @param <R> the return type of the operation implemented by this 4523 * visitor; use Void if no return type is needed. 4524 * @param <S> the type of the second argument (the first being the 4525 * type itself) of the operation implemented by this visitor; use 4526 * Void if a second argument is not needed. 4527 */ 4528 public static abstract class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> { 4529 final public R visit(Type t, S s) { return t.accept(this, s); } 4530 public R visitClassType(ClassType t, S s) { return visitType(t, s); } 4531 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); } 4532 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); } 4533 public R visitMethodType(MethodType t, S s) { return visitType(t, s); } 4534 public R visitPackageType(PackageType t, S s) { return visitType(t, s); } 4535 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); } 4536 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); } 4537 public R visitForAll(ForAll t, S s) { return visitType(t, s); } 4538 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); } 4539 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); } 4540 } 4541 4542 /** 4543 * A default visitor for symbols. All visitor methods except 4544 * visitSymbol are implemented by delegating to visitSymbol. Concrete 4545 * subclasses must provide an implementation of visitSymbol and can 4546 * override other methods as needed. 4547 * 4548 * @param <R> the return type of the operation implemented by this 4549 * visitor; use Void if no return type is needed. 4550 * @param <S> the type of the second argument (the first being the 4551 * symbol itself) of the operation implemented by this visitor; use 4552 * Void if a second argument is not needed. 4553 */ 4554 public static abstract class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> { 4555 final public R visit(Symbol s, S arg) { return s.accept(this, arg); } 4556 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); } 4557 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); } 4558 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); } 4559 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); } 4560 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); } 4561 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); } 4562 } 4563 4564 /** 4565 * A <em>simple</em> visitor for types. This visitor is simple as 4566 * captured wildcards, for-all types (generic methods), and 4567 * undetermined type variables (part of inference) are hidden. 4568 * Captured wildcards are hidden by treating them as type 4569 * variables and the rest are hidden by visiting their qtypes. 4570 * 4571 * @param <R> the return type of the operation implemented by this 4572 * visitor; use Void if no return type is needed. 4573 * @param <S> the type of the second argument (the first being the 4574 * type itself) of the operation implemented by this visitor; use 4575 * Void if a second argument is not needed. 4576 */ 4577 public static abstract class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> { 4578 @Override 4579 public R visitCapturedType(CapturedType t, S s) { 4580 return visitTypeVar(t, s); 4581 } 4582 @Override 4583 public R visitForAll(ForAll t, S s) { 4584 return visit(t.qtype, s); 4585 } 4586 @Override 4587 public R visitUndetVar(UndetVar t, S s) { 4588 return visit(t.qtype, s); 4589 } 4590 } 4591 4592 /** 4593 * A plain relation on types. That is a 2-ary function on the 4594 * form Type × Type → Boolean. 4595 * <!-- In plain text: Type x Type -> Boolean --> 4596 */ 4597 public static abstract class TypeRelation extends SimpleVisitor<Boolean,Type> {} 4598 4599 /** 4600 * A convenience visitor for implementing operations that only 4601 * require one argument (the type itself), that is, unary 4602 * operations. 4603 * 4604 * @param <R> the return type of the operation implemented by this 4605 * visitor; use Void if no return type is needed. 4606 */ 4607 public static abstract class UnaryVisitor<R> extends SimpleVisitor<R,Void> { 4608 final public R visit(Type t) { return t.accept(this, null); } 4609 } 4610 4611 /** 4612 * A visitor for implementing a mapping from types to types. The 4613 * default behavior of this class is to implement the identity 4614 * mapping (mapping a type to itself). This can be overridden in 4615 * subclasses. 4616 * 4617 * @param <S> the type of the second argument (the first being the 4618 * type itself) of this mapping; use Void if a second argument is 4619 * not needed. 4620 */ 4621 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> { 4622 final public Type visit(Type t) { return t.accept(this, null); } 4623 public Type visitType(Type t, S s) { return t; } 4624 } 4625 // </editor-fold> 4626 4627 4628 // <editor-fold defaultstate="collapsed" desc="Annotation support"> 4629 4630 public RetentionPolicy getRetention(Attribute.Compound a) { 4631 return getRetention(a.type.tsym); 4632 } 4633 4634 public RetentionPolicy getRetention(Symbol sym) { 4635 RetentionPolicy vis = RetentionPolicy.CLASS; // the default 4636 Attribute.Compound c = sym.attribute(syms.retentionType.tsym); 4637 if (c != null) { 4638 Attribute value = c.member(names.value); 4639 if (value != null && value instanceof Attribute.Enum) { 4640 Name levelName = ((Attribute.Enum)value).value.name; 4641 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE; 4642 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS; 4643 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME; 4644 else ;// /* fail soft */ throw new AssertionError(levelName); 4645 } 4646 } 4647 return vis; 4648 } 4649 // </editor-fold> 4650 4651 // <editor-fold defaultstate="collapsed" desc="Signature Generation"> 4652 4653 public static abstract class SignatureGenerator { 4654 4655 private final Types types; 4656 4657 protected abstract void append(char ch); 4658 protected abstract void append(byte[] ba); 4659 protected abstract void append(Name name); 4660 protected void classReference(ClassSymbol c) { /* by default: no-op */ } 4661 4662 protected SignatureGenerator(Types types) { 4663 this.types = types; 4664 } 4665 4666 /** 4667 * Assemble signature of given type in string buffer. 4668 */ 4669 public void assembleSig(Type type) { 4670 switch (type.getTag()) { 4671 case BYTE: 4672 append('B'); 4673 break; 4674 case SHORT: 4675 append('S'); 4676 break; 4677 case CHAR: 4678 append('C'); 4679 break; 4680 case INT: 4681 append('I'); 4682 break; 4683 case LONG: 4684 append('J'); 4685 break; 4686 case FLOAT: 4687 append('F'); 4688 break; 4689 case DOUBLE: 4690 append('D'); 4691 break; 4692 case BOOLEAN: 4693 append('Z'); 4694 break; 4695 case VOID: 4696 append('V'); 4697 break; 4698 case CLASS: 4699 append('L'); 4700 assembleClassSig(type); 4701 append(';'); 4702 break; 4703 case ARRAY: 4704 ArrayType at = (ArrayType) type; 4705 append('['); 4706 assembleSig(at.elemtype); 4707 break; 4708 case METHOD: 4709 MethodType mt = (MethodType) type; 4710 append('('); 4711 assembleSig(mt.argtypes); 4712 append(')'); 4713 assembleSig(mt.restype); 4714 if (hasTypeVar(mt.thrown)) { 4715 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) { 4716 append('^'); 4717 assembleSig(l.head); 4718 } 4719 } 4720 break; 4721 case WILDCARD: { 4722 Type.WildcardType ta = (Type.WildcardType) type; 4723 switch (ta.kind) { 4724 case SUPER: 4725 append('-'); 4726 assembleSig(ta.type); 4727 break; 4728 case EXTENDS: 4729 append('+'); 4730 assembleSig(ta.type); 4731 break; 4732 case UNBOUND: 4733 append('*'); 4734 break; 4735 default: 4736 throw new AssertionError(ta.kind); 4737 } 4738 break; 4739 } 4740 case TYPEVAR: 4741 append('T'); 4742 append(type.tsym.name); 4743 append(';'); 4744 break; 4745 case FORALL: 4746 Type.ForAll ft = (Type.ForAll) type; 4747 assembleParamsSig(ft.tvars); 4748 assembleSig(ft.qtype); 4749 break; 4750 default: 4751 throw new AssertionError("typeSig " + type.getTag()); 4752 } 4753 } 4754 4755 public boolean hasTypeVar(List<Type> l) { 4756 while (l.nonEmpty()) { 4757 if (l.head.hasTag(TypeTag.TYPEVAR)) { 4758 return true; 4759 } 4760 l = l.tail; 4761 } 4762 return false; 4763 } 4764 4765 public void assembleClassSig(Type type) { 4766 ClassType ct = (ClassType) type; 4767 ClassSymbol c = (ClassSymbol) ct.tsym; 4768 classReference(c); 4769 Type outer = ct.getEnclosingType(); 4770 if (outer.allparams().nonEmpty()) { 4771 boolean rawOuter = 4772 c.owner.kind == MTH || // either a local class 4773 c.name == types.names.empty; // or anonymous 4774 assembleClassSig(rawOuter 4775 ? types.erasure(outer) 4776 : outer); 4777 append(rawOuter ? '$' : '.'); 4778 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname)); 4779 append(rawOuter 4780 ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength()) 4781 : c.name); 4782 } else { 4783 append(externalize(c.flatname)); 4784 } 4785 if (ct.getTypeArguments().nonEmpty()) { 4786 append('<'); 4787 assembleSig(ct.getTypeArguments()); 4788 append('>'); 4789 } 4790 } 4791 4792 public void assembleParamsSig(List<Type> typarams) { 4793 append('<'); 4794 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) { 4795 Type.TypeVar tvar = (Type.TypeVar) ts.head; 4796 append(tvar.tsym.name); 4797 List<Type> bounds = types.getBounds(tvar); 4798 if ((bounds.head.tsym.flags() & INTERFACE) != 0) { 4799 append(':'); 4800 } 4801 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) { 4802 append(':'); 4803 assembleSig(l.head); 4804 } 4805 } 4806 append('>'); 4807 } 4808 4809 private void assembleSig(List<Type> types) { 4810 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) { 4811 assembleSig(ts.head); 4812 } 4813 } 4814 } 4815 // </editor-fold> 4816 4817 public void newRound() { 4818 descCache._map.clear(); 4819 isDerivedRawCache.clear(); 4820 implCache._map.clear(); 4821 membersCache._map.clear(); 4822 closureCache.clear(); 4823 } 4824} 4825