Resolve.java revision 2830:414b82835861
1/* 2 * Copyright (c) 1999, 2014, 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.comp; 27 28import com.sun.tools.javac.api.Formattable.LocalizedString; 29import com.sun.tools.javac.code.*; 30import com.sun.tools.javac.code.Scope.WriteableScope; 31import com.sun.tools.javac.code.Symbol.*; 32import com.sun.tools.javac.code.Type.*; 33import com.sun.tools.javac.comp.Attr.ResultInfo; 34import com.sun.tools.javac.comp.Check.CheckContext; 35import com.sun.tools.javac.comp.DeferredAttr.AttrMode; 36import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext; 37import com.sun.tools.javac.comp.DeferredAttr.DeferredType; 38import com.sun.tools.javac.comp.Infer.InferenceContext; 39import com.sun.tools.javac.comp.Infer.FreeTypeListener; 40import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate; 41import com.sun.tools.javac.comp.Resolve.MethodResolutionDiagHelper.Template; 42import com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind; 43import com.sun.tools.javac.jvm.*; 44import com.sun.tools.javac.main.Option; 45import com.sun.tools.javac.tree.*; 46import com.sun.tools.javac.tree.JCTree.*; 47import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind; 48import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*; 49import com.sun.tools.javac.util.*; 50import com.sun.tools.javac.util.DefinedBy.Api; 51import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag; 52import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 53import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType; 54 55import java.util.Arrays; 56import java.util.Collection; 57import java.util.EnumSet; 58import java.util.Iterator; 59import java.util.LinkedHashMap; 60import java.util.Map; 61import java.util.function.BiPredicate; 62import java.util.stream.Stream; 63 64import javax.lang.model.element.ElementVisitor; 65 66import static com.sun.tools.javac.code.Flags.*; 67import static com.sun.tools.javac.code.Flags.BLOCK; 68import static com.sun.tools.javac.code.Flags.STATIC; 69import static com.sun.tools.javac.code.Kinds.*; 70import static com.sun.tools.javac.code.Kinds.Kind.*; 71import static com.sun.tools.javac.code.TypeTag.*; 72import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*; 73import static com.sun.tools.javac.tree.JCTree.Tag.*; 74 75/** Helper class for name resolution, used mostly by the attribution phase. 76 * 77 * <p><b>This is NOT part of any supported API. 78 * If you write code that depends on this, you do so at your own risk. 79 * This code and its internal interfaces are subject to change or 80 * deletion without notice.</b> 81 */ 82public class Resolve { 83 protected static final Context.Key<Resolve> resolveKey = new Context.Key<>(); 84 85 Names names; 86 Log log; 87 Symtab syms; 88 Attr attr; 89 DeferredAttr deferredAttr; 90 Check chk; 91 Infer infer; 92 ClassFinder finder; 93 Types types; 94 JCDiagnostic.Factory diags; 95 public final boolean allowMethodHandles; 96 public final boolean allowFunctionalInterfaceMostSpecific; 97 public final boolean checkVarargsAccessAfterResolution; 98 private final boolean debugResolve; 99 private final boolean compactMethodDiags; 100 final EnumSet<VerboseResolutionMode> verboseResolutionMode; 101 102 WriteableScope polymorphicSignatureScope; 103 104 protected Resolve(Context context) { 105 context.put(resolveKey, this); 106 syms = Symtab.instance(context); 107 108 varNotFound = new SymbolNotFoundError(ABSENT_VAR); 109 methodNotFound = new SymbolNotFoundError(ABSENT_MTH); 110 typeNotFound = new SymbolNotFoundError(ABSENT_TYP); 111 referenceNotFound = new ReferenceLookupResult(methodNotFound, null); 112 113 names = Names.instance(context); 114 log = Log.instance(context); 115 attr = Attr.instance(context); 116 deferredAttr = DeferredAttr.instance(context); 117 chk = Check.instance(context); 118 infer = Infer.instance(context); 119 finder = ClassFinder.instance(context); 120 types = Types.instance(context); 121 diags = JCDiagnostic.Factory.instance(context); 122 Source source = Source.instance(context); 123 Options options = Options.instance(context); 124 debugResolve = options.isSet("debugresolve"); 125 compactMethodDiags = options.isSet(Option.XDIAGS, "compact") || 126 options.isUnset(Option.XDIAGS) && options.isUnset("rawDiagnostics"); 127 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options); 128 Target target = Target.instance(context); 129 allowMethodHandles = target.hasMethodHandles(); 130 allowFunctionalInterfaceMostSpecific = source.allowFunctionalInterfaceMostSpecific(); 131 checkVarargsAccessAfterResolution = 132 source.allowPostApplicabilityVarargsAccessCheck(); 133 polymorphicSignatureScope = WriteableScope.create(syms.noSymbol); 134 135 inapplicableMethodException = new InapplicableMethodException(diags); 136 } 137 138 /** error symbols, which are returned when resolution fails 139 */ 140 private final SymbolNotFoundError varNotFound; 141 private final SymbolNotFoundError methodNotFound; 142 private final SymbolNotFoundError typeNotFound; 143 144 /** empty reference lookup result */ 145 private final ReferenceLookupResult referenceNotFound; 146 147 public static Resolve instance(Context context) { 148 Resolve instance = context.get(resolveKey); 149 if (instance == null) 150 instance = new Resolve(context); 151 return instance; 152 } 153 154 private static Symbol bestOf(Symbol s1, 155 Symbol s2) { 156 return s1.kind.betterThan(s2.kind) ? s1 : s2; 157 } 158 159 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support"> 160 enum VerboseResolutionMode { 161 SUCCESS("success"), 162 FAILURE("failure"), 163 APPLICABLE("applicable"), 164 INAPPLICABLE("inapplicable"), 165 DEFERRED_INST("deferred-inference"), 166 PREDEF("predef"), 167 OBJECT_INIT("object-init"), 168 INTERNAL("internal"); 169 170 final String opt; 171 172 private VerboseResolutionMode(String opt) { 173 this.opt = opt; 174 } 175 176 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) { 177 String s = opts.get("verboseResolution"); 178 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class); 179 if (s == null) return res; 180 if (s.contains("all")) { 181 res = EnumSet.allOf(VerboseResolutionMode.class); 182 } 183 Collection<String> args = Arrays.asList(s.split(",")); 184 for (VerboseResolutionMode mode : values()) { 185 if (args.contains(mode.opt)) { 186 res.add(mode); 187 } else if (args.contains("-" + mode.opt)) { 188 res.remove(mode); 189 } 190 } 191 return res; 192 } 193 } 194 195 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site, 196 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) { 197 boolean success = !bestSoFar.kind.isOverloadError(); 198 199 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) { 200 return; 201 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) { 202 return; 203 } 204 205 if (bestSoFar.name == names.init && 206 bestSoFar.owner == syms.objectType.tsym && 207 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) { 208 return; //skip diags for Object constructor resolution 209 } else if (site == syms.predefClass.type && 210 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) { 211 return; //skip spurious diags for predef symbols (i.e. operators) 212 } else if (currentResolutionContext.internalResolution && 213 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) { 214 return; 215 } 216 217 int pos = 0; 218 int mostSpecificPos = -1; 219 ListBuffer<JCDiagnostic> subDiags = new ListBuffer<>(); 220 for (Candidate c : currentResolutionContext.candidates) { 221 if (currentResolutionContext.step != c.step || 222 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) || 223 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) { 224 continue; 225 } else { 226 subDiags.append(c.isApplicable() ? 227 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) : 228 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details)); 229 if (c.sym == bestSoFar) 230 mostSpecificPos = pos; 231 pos++; 232 } 233 } 234 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1"; 235 List<Type> argtypes2 = Type.map(argtypes, 236 deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step)); 237 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name, 238 site.tsym, mostSpecificPos, currentResolutionContext.step, 239 methodArguments(argtypes2), 240 methodArguments(typeargtypes)); 241 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList()); 242 log.report(d); 243 } 244 245 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) { 246 JCDiagnostic subDiag = null; 247 if (sym.type.hasTag(FORALL)) { 248 subDiag = diags.fragment("partial.inst.sig", inst); 249 } 250 251 String key = subDiag == null ? 252 "applicable.method.found" : 253 "applicable.method.found.1"; 254 255 return diags.fragment(key, pos, sym, subDiag); 256 } 257 258 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) { 259 return diags.fragment("not.applicable.method.found", pos, sym, subDiag); 260 } 261 // </editor-fold> 262 263/* ************************************************************************ 264 * Identifier resolution 265 *************************************************************************/ 266 267 /** An environment is "static" if its static level is greater than 268 * the one of its outer environment 269 */ 270 protected static boolean isStatic(Env<AttrContext> env) { 271 return env.outer != null && env.info.staticLevel > env.outer.info.staticLevel; 272 } 273 274 /** An environment is an "initializer" if it is a constructor or 275 * an instance initializer. 276 */ 277 static boolean isInitializer(Env<AttrContext> env) { 278 Symbol owner = env.info.scope.owner; 279 return owner.isConstructor() || 280 owner.owner.kind == TYP && 281 (owner.kind == VAR || 282 owner.kind == MTH && (owner.flags() & BLOCK) != 0) && 283 (owner.flags() & STATIC) == 0; 284 } 285 286 /** Is class accessible in given evironment? 287 * @param env The current environment. 288 * @param c The class whose accessibility is checked. 289 */ 290 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) { 291 return isAccessible(env, c, false); 292 } 293 294 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) { 295 boolean isAccessible = false; 296 switch ((short)(c.flags() & AccessFlags)) { 297 case PRIVATE: 298 isAccessible = 299 env.enclClass.sym.outermostClass() == 300 c.owner.outermostClass(); 301 break; 302 case 0: 303 isAccessible = 304 env.toplevel.packge == c.owner // fast special case 305 || 306 env.toplevel.packge == c.packge() 307 || 308 // Hack: this case is added since synthesized default constructors 309 // of anonymous classes should be allowed to access 310 // classes which would be inaccessible otherwise. 311 env.enclMethod != null && 312 (env.enclMethod.mods.flags & ANONCONSTR) != 0; 313 break; 314 default: // error recovery 315 case PUBLIC: 316 isAccessible = true; 317 break; 318 case PROTECTED: 319 isAccessible = 320 env.toplevel.packge == c.owner // fast special case 321 || 322 env.toplevel.packge == c.packge() 323 || 324 isInnerSubClass(env.enclClass.sym, c.owner); 325 break; 326 } 327 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ? 328 isAccessible : 329 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner); 330 } 331 //where 332 /** Is given class a subclass of given base class, or an inner class 333 * of a subclass? 334 * Return null if no such class exists. 335 * @param c The class which is the subclass or is contained in it. 336 * @param base The base class 337 */ 338 private boolean isInnerSubClass(ClassSymbol c, Symbol base) { 339 while (c != null && !c.isSubClass(base, types)) { 340 c = c.owner.enclClass(); 341 } 342 return c != null; 343 } 344 345 boolean isAccessible(Env<AttrContext> env, Type t) { 346 return isAccessible(env, t, false); 347 } 348 349 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) { 350 return (t.hasTag(ARRAY)) 351 ? isAccessible(env, types.cvarUpperBound(types.elemtype(t))) 352 : isAccessible(env, t.tsym, checkInner); 353 } 354 355 /** Is symbol accessible as a member of given type in given environment? 356 * @param env The current environment. 357 * @param site The type of which the tested symbol is regarded 358 * as a member. 359 * @param sym The symbol. 360 */ 361 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) { 362 return isAccessible(env, site, sym, false); 363 } 364 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) { 365 if (sym.name == names.init && sym.owner != site.tsym) return false; 366 switch ((short)(sym.flags() & AccessFlags)) { 367 case PRIVATE: 368 return 369 (env.enclClass.sym == sym.owner // fast special case 370 || 371 env.enclClass.sym.outermostClass() == 372 sym.owner.outermostClass()) 373 && 374 sym.isInheritedIn(site.tsym, types); 375 case 0: 376 return 377 (env.toplevel.packge == sym.owner.owner // fast special case 378 || 379 env.toplevel.packge == sym.packge()) 380 && 381 isAccessible(env, site, checkInner) 382 && 383 sym.isInheritedIn(site.tsym, types) 384 && 385 notOverriddenIn(site, sym); 386 case PROTECTED: 387 return 388 (env.toplevel.packge == sym.owner.owner // fast special case 389 || 390 env.toplevel.packge == sym.packge() 391 || 392 isProtectedAccessible(sym, env.enclClass.sym, site) 393 || 394 // OK to select instance method or field from 'super' or type name 395 // (but type names should be disallowed elsewhere!) 396 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP) 397 && 398 isAccessible(env, site, checkInner) 399 && 400 notOverriddenIn(site, sym); 401 default: // this case includes erroneous combinations as well 402 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym); 403 } 404 } 405 //where 406 /* `sym' is accessible only if not overridden by 407 * another symbol which is a member of `site' 408 * (because, if it is overridden, `sym' is not strictly 409 * speaking a member of `site'). A polymorphic signature method 410 * cannot be overridden (e.g. MH.invokeExact(Object[])). 411 */ 412 private boolean notOverriddenIn(Type site, Symbol sym) { 413 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic()) 414 return true; 415 else { 416 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true); 417 return (s2 == null || s2 == sym || sym.owner == s2.owner || 418 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym))); 419 } 420 } 421 //where 422 /** Is given protected symbol accessible if it is selected from given site 423 * and the selection takes place in given class? 424 * @param sym The symbol with protected access 425 * @param c The class where the access takes place 426 * @site The type of the qualifier 427 */ 428 private 429 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) { 430 Type newSite = site.hasTag(TYPEVAR) ? site.getUpperBound() : site; 431 while (c != null && 432 !(c.isSubClass(sym.owner, types) && 433 (c.flags() & INTERFACE) == 0 && 434 // In JLS 2e 6.6.2.1, the subclass restriction applies 435 // only to instance fields and methods -- types are excluded 436 // regardless of whether they are declared 'static' or not. 437 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || newSite.tsym.isSubClass(c, types)))) 438 c = c.owner.enclClass(); 439 return c != null; 440 } 441 442 /** 443 * Performs a recursive scan of a type looking for accessibility problems 444 * from current attribution environment 445 */ 446 void checkAccessibleType(Env<AttrContext> env, Type t) { 447 accessibilityChecker.visit(t, env); 448 } 449 450 /** 451 * Accessibility type-visitor 452 */ 453 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker = 454 new Types.SimpleVisitor<Void, Env<AttrContext>>() { 455 456 void visit(List<Type> ts, Env<AttrContext> env) { 457 for (Type t : ts) { 458 visit(t, env); 459 } 460 } 461 462 public Void visitType(Type t, Env<AttrContext> env) { 463 return null; 464 } 465 466 @Override 467 public Void visitArrayType(ArrayType t, Env<AttrContext> env) { 468 visit(t.elemtype, env); 469 return null; 470 } 471 472 @Override 473 public Void visitClassType(ClassType t, Env<AttrContext> env) { 474 visit(t.getTypeArguments(), env); 475 if (!isAccessible(env, t, true)) { 476 accessBase(new AccessError(t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true); 477 } 478 return null; 479 } 480 481 @Override 482 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) { 483 visit(t.type, env); 484 return null; 485 } 486 487 @Override 488 public Void visitMethodType(MethodType t, Env<AttrContext> env) { 489 visit(t.getParameterTypes(), env); 490 visit(t.getReturnType(), env); 491 visit(t.getThrownTypes(), env); 492 return null; 493 } 494 }; 495 496 /** Try to instantiate the type of a method so that it fits 497 * given type arguments and argument types. If successful, return 498 * the method's instantiated type, else return null. 499 * The instantiation will take into account an additional leading 500 * formal parameter if the method is an instance method seen as a member 501 * of an under determined site. In this case, we treat site as an additional 502 * parameter and the parameters of the class containing the method as 503 * additional type variables that get instantiated. 504 * 505 * @param env The current environment 506 * @param site The type of which the method is a member. 507 * @param m The method symbol. 508 * @param argtypes The invocation's given value arguments. 509 * @param typeargtypes The invocation's given type arguments. 510 * @param allowBoxing Allow boxing conversions of arguments. 511 * @param useVarargs Box trailing arguments into an array for varargs. 512 */ 513 Type rawInstantiate(Env<AttrContext> env, 514 Type site, 515 Symbol m, 516 ResultInfo resultInfo, 517 List<Type> argtypes, 518 List<Type> typeargtypes, 519 boolean allowBoxing, 520 boolean useVarargs, 521 Warner warn) throws Infer.InferenceException { 522 Type mt = types.memberType(site, m); 523 // tvars is the list of formal type variables for which type arguments 524 // need to inferred. 525 List<Type> tvars = List.nil(); 526 if (typeargtypes == null) typeargtypes = List.nil(); 527 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) { 528 // This is not a polymorphic method, but typeargs are supplied 529 // which is fine, see JLS 15.12.2.1 530 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) { 531 ForAll pmt = (ForAll) mt; 532 if (typeargtypes.length() != pmt.tvars.length()) 533 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args 534 // Check type arguments are within bounds 535 List<Type> formals = pmt.tvars; 536 List<Type> actuals = typeargtypes; 537 while (formals.nonEmpty() && actuals.nonEmpty()) { 538 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head), 539 pmt.tvars, typeargtypes); 540 for (; bounds.nonEmpty(); bounds = bounds.tail) { 541 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn)) 542 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds); 543 } 544 formals = formals.tail; 545 actuals = actuals.tail; 546 } 547 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes); 548 } else if (mt.hasTag(FORALL)) { 549 ForAll pmt = (ForAll) mt; 550 List<Type> tvars1 = types.newInstances(pmt.tvars); 551 tvars = tvars.appendList(tvars1); 552 mt = types.subst(pmt.qtype, pmt.tvars, tvars1); 553 } 554 555 // find out whether we need to go the slow route via infer 556 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/ 557 for (List<Type> l = argtypes; 558 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded; 559 l = l.tail) { 560 if (l.head.hasTag(FORALL)) instNeeded = true; 561 } 562 563 if (instNeeded) { 564 return infer.instantiateMethod(env, 565 tvars, 566 (MethodType)mt, 567 resultInfo, 568 (MethodSymbol)m, 569 argtypes, 570 allowBoxing, 571 useVarargs, 572 currentResolutionContext, 573 warn); 574 } 575 576 DeferredAttr.DeferredAttrContext dc = currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn); 577 currentResolutionContext.methodCheck.argumentsAcceptable(env, dc, 578 argtypes, mt.getParameterTypes(), warn); 579 dc.complete(); 580 return mt; 581 } 582 583 Type checkMethod(Env<AttrContext> env, 584 Type site, 585 Symbol m, 586 ResultInfo resultInfo, 587 List<Type> argtypes, 588 List<Type> typeargtypes, 589 Warner warn) { 590 MethodResolutionContext prevContext = currentResolutionContext; 591 try { 592 currentResolutionContext = new MethodResolutionContext(); 593 currentResolutionContext.attrMode = DeferredAttr.AttrMode.CHECK; 594 if (env.tree.hasTag(JCTree.Tag.REFERENCE)) { 595 //method/constructor references need special check class 596 //to handle inference variables in 'argtypes' (might happen 597 //during an unsticking round) 598 currentResolutionContext.methodCheck = 599 new MethodReferenceCheck(resultInfo.checkContext.inferenceContext()); 600 } 601 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase; 602 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes, 603 step.isBoxingRequired(), step.isVarargsRequired(), warn); 604 } 605 finally { 606 currentResolutionContext = prevContext; 607 } 608 } 609 610 /** Same but returns null instead throwing a NoInstanceException 611 */ 612 Type instantiate(Env<AttrContext> env, 613 Type site, 614 Symbol m, 615 ResultInfo resultInfo, 616 List<Type> argtypes, 617 List<Type> typeargtypes, 618 boolean allowBoxing, 619 boolean useVarargs, 620 Warner warn) { 621 try { 622 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes, 623 allowBoxing, useVarargs, warn); 624 } catch (InapplicableMethodException ex) { 625 return null; 626 } 627 } 628 629 /** 630 * This interface defines an entry point that should be used to perform a 631 * method check. A method check usually consist in determining as to whether 632 * a set of types (actuals) is compatible with another set of types (formals). 633 * Since the notion of compatibility can vary depending on the circumstances, 634 * this interfaces allows to easily add new pluggable method check routines. 635 */ 636 interface MethodCheck { 637 /** 638 * Main method check routine. A method check usually consist in determining 639 * as to whether a set of types (actuals) is compatible with another set of 640 * types (formals). If an incompatibility is found, an unchecked exception 641 * is assumed to be thrown. 642 */ 643 void argumentsAcceptable(Env<AttrContext> env, 644 DeferredAttrContext deferredAttrContext, 645 List<Type> argtypes, 646 List<Type> formals, 647 Warner warn); 648 649 /** 650 * Retrieve the method check object that will be used during a 651 * most specific check. 652 */ 653 MethodCheck mostSpecificCheck(List<Type> actuals); 654 } 655 656 /** 657 * Helper enum defining all method check diagnostics (used by resolveMethodCheck). 658 */ 659 enum MethodCheckDiag { 660 /** 661 * Actuals and formals differs in length. 662 */ 663 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"), 664 /** 665 * An actual is incompatible with a formal. 666 */ 667 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"), 668 /** 669 * An actual is incompatible with the varargs element type. 670 */ 671 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"), 672 /** 673 * The varargs element type is inaccessible. 674 */ 675 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type"); 676 677 final String basicKey; 678 final String inferKey; 679 680 MethodCheckDiag(String basicKey, String inferKey) { 681 this.basicKey = basicKey; 682 this.inferKey = inferKey; 683 } 684 685 String regex() { 686 return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey); 687 } 688 } 689 690 /** 691 * Dummy method check object. All methods are deemed applicable, regardless 692 * of their formal parameter types. 693 */ 694 MethodCheck nilMethodCheck = new MethodCheck() { 695 public void argumentsAcceptable(Env<AttrContext> env, DeferredAttrContext deferredAttrContext, List<Type> argtypes, List<Type> formals, Warner warn) { 696 //do nothing - method always applicable regardless of actuals 697 } 698 699 public MethodCheck mostSpecificCheck(List<Type> actuals) { 700 return this; 701 } 702 }; 703 704 /** 705 * Base class for 'real' method checks. The class defines the logic for 706 * iterating through formals and actuals and provides and entry point 707 * that can be used by subclasses in order to define the actual check logic. 708 */ 709 abstract class AbstractMethodCheck implements MethodCheck { 710 @Override 711 public void argumentsAcceptable(final Env<AttrContext> env, 712 DeferredAttrContext deferredAttrContext, 713 List<Type> argtypes, 714 List<Type> formals, 715 Warner warn) { 716 //should we expand formals? 717 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired(); 718 List<JCExpression> trees = TreeInfo.args(env.tree); 719 720 //inference context used during this method check 721 InferenceContext inferenceContext = deferredAttrContext.inferenceContext; 722 723 Type varargsFormal = useVarargs ? formals.last() : null; 724 725 if (varargsFormal == null && 726 argtypes.size() != formals.size()) { 727 reportMC(env.tree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args 728 } 729 730 while (argtypes.nonEmpty() && formals.head != varargsFormal) { 731 DiagnosticPosition pos = trees != null ? trees.head : null; 732 checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn); 733 argtypes = argtypes.tail; 734 formals = formals.tail; 735 trees = trees != null ? trees.tail : trees; 736 } 737 738 if (formals.head != varargsFormal) { 739 reportMC(env.tree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args 740 } 741 742 if (useVarargs) { 743 //note: if applicability check is triggered by most specific test, 744 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5) 745 final Type elt = types.elemtype(varargsFormal); 746 while (argtypes.nonEmpty()) { 747 DiagnosticPosition pos = trees != null ? trees.head : null; 748 checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn); 749 argtypes = argtypes.tail; 750 trees = trees != null ? trees.tail : trees; 751 } 752 } 753 } 754 755 /** 756 * Does the actual argument conforms to the corresponding formal? 757 */ 758 abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn); 759 760 protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) { 761 boolean inferDiag = inferenceContext != infer.emptyContext; 762 InapplicableMethodException ex = inferDiag ? 763 infer.inferenceException : inapplicableMethodException; 764 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) { 765 Object[] args2 = new Object[args.length + 1]; 766 System.arraycopy(args, 0, args2, 1, args.length); 767 args2[0] = inferenceContext.inferenceVars(); 768 args = args2; 769 } 770 String key = inferDiag ? diag.inferKey : diag.basicKey; 771 throw ex.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args)); 772 } 773 774 public MethodCheck mostSpecificCheck(List<Type> actuals) { 775 return nilMethodCheck; 776 } 777 778 } 779 780 /** 781 * Arity-based method check. A method is applicable if the number of actuals 782 * supplied conforms to the method signature. 783 */ 784 MethodCheck arityMethodCheck = new AbstractMethodCheck() { 785 @Override 786 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) { 787 //do nothing - actual always compatible to formals 788 } 789 790 @Override 791 public String toString() { 792 return "arityMethodCheck"; 793 } 794 }; 795 796 List<Type> dummyArgs(int length) { 797 ListBuffer<Type> buf = new ListBuffer<>(); 798 for (int i = 0 ; i < length ; i++) { 799 buf.append(Type.noType); 800 } 801 return buf.toList(); 802 } 803 804 /** 805 * Main method applicability routine. Given a list of actual types A, 806 * a list of formal types F, determines whether the types in A are 807 * compatible (by method invocation conversion) with the types in F. 808 * 809 * Since this routine is shared between overload resolution and method 810 * type-inference, a (possibly empty) inference context is used to convert 811 * formal types to the corresponding 'undet' form ahead of a compatibility 812 * check so that constraints can be propagated and collected. 813 * 814 * Moreover, if one or more types in A is a deferred type, this routine uses 815 * DeferredAttr in order to perform deferred attribution. If one or more actual 816 * deferred types are stuck, they are placed in a queue and revisited later 817 * after the remainder of the arguments have been seen. If this is not sufficient 818 * to 'unstuck' the argument, a cyclic inference error is called out. 819 * 820 * A method check handler (see above) is used in order to report errors. 821 */ 822 MethodCheck resolveMethodCheck = new AbstractMethodCheck() { 823 824 @Override 825 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) { 826 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn); 827 mresult.check(pos, actual); 828 } 829 830 @Override 831 public void argumentsAcceptable(final Env<AttrContext> env, 832 DeferredAttrContext deferredAttrContext, 833 List<Type> argtypes, 834 List<Type> formals, 835 Warner warn) { 836 super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn); 837 //should we expand formals? 838 if (deferredAttrContext.phase.isVarargsRequired()) { 839 Type typeToCheck = null; 840 if (!checkVarargsAccessAfterResolution) { 841 typeToCheck = types.elemtype(formals.last()); 842 } else if (deferredAttrContext.mode == AttrMode.CHECK) { 843 typeToCheck = types.erasure(types.elemtype(formals.last())); 844 } 845 if (typeToCheck != null) { 846 varargsAccessible(env, typeToCheck, deferredAttrContext.inferenceContext); 847 } 848 } 849 } 850 851 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) { 852 if (inferenceContext.free(t)) { 853 inferenceContext.addFreeTypeListener(List.of(t), new FreeTypeListener() { 854 @Override 855 public void typesInferred(InferenceContext inferenceContext) { 856 varargsAccessible(env, inferenceContext.asInstType(t), inferenceContext); 857 } 858 }); 859 } else { 860 if (!isAccessible(env, t)) { 861 Symbol location = env.enclClass.sym; 862 reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location); 863 } 864 } 865 } 866 867 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to, 868 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) { 869 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) { 870 MethodCheckDiag methodDiag = varargsCheck ? 871 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH; 872 873 @Override 874 public void report(DiagnosticPosition pos, JCDiagnostic details) { 875 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details); 876 } 877 }; 878 return new MethodResultInfo(to, checkContext); 879 } 880 881 @Override 882 public MethodCheck mostSpecificCheck(List<Type> actuals) { 883 return new MostSpecificCheck(actuals); 884 } 885 886 @Override 887 public String toString() { 888 return "resolveMethodCheck"; 889 } 890 }; 891 892 /** 893 * This class handles method reference applicability checks; since during 894 * these checks it's sometime possible to have inference variables on 895 * the actual argument types list, the method applicability check must be 896 * extended so that inference variables are 'opened' as needed. 897 */ 898 class MethodReferenceCheck extends AbstractMethodCheck { 899 900 InferenceContext pendingInferenceContext; 901 902 MethodReferenceCheck(InferenceContext pendingInferenceContext) { 903 this.pendingInferenceContext = pendingInferenceContext; 904 } 905 906 @Override 907 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) { 908 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn); 909 mresult.check(pos, actual); 910 } 911 912 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to, 913 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) { 914 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) { 915 MethodCheckDiag methodDiag = varargsCheck ? 916 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH; 917 918 @Override 919 public boolean compatible(Type found, Type req, Warner warn) { 920 found = pendingInferenceContext.asUndetVar(found); 921 if (found.hasTag(UNDETVAR) && req.isPrimitive()) { 922 req = types.boxedClass(req).type; 923 } 924 return super.compatible(found, req, warn); 925 } 926 927 @Override 928 public void report(DiagnosticPosition pos, JCDiagnostic details) { 929 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details); 930 } 931 }; 932 return new MethodResultInfo(to, checkContext); 933 } 934 935 @Override 936 public MethodCheck mostSpecificCheck(List<Type> actuals) { 937 return new MostSpecificCheck(actuals); 938 } 939 940 @Override 941 public String toString() { 942 return "MethodReferenceCheck"; 943 } 944 } 945 946 /** 947 * Check context to be used during method applicability checks. A method check 948 * context might contain inference variables. 949 */ 950 abstract class MethodCheckContext implements CheckContext { 951 952 boolean strict; 953 DeferredAttrContext deferredAttrContext; 954 Warner rsWarner; 955 956 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) { 957 this.strict = strict; 958 this.deferredAttrContext = deferredAttrContext; 959 this.rsWarner = rsWarner; 960 } 961 962 public boolean compatible(Type found, Type req, Warner warn) { 963 InferenceContext inferenceContext = deferredAttrContext.inferenceContext; 964 return strict ? 965 types.isSubtypeUnchecked(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn) : 966 types.isConvertible(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn); 967 } 968 969 public void report(DiagnosticPosition pos, JCDiagnostic details) { 970 throw inapplicableMethodException.setMessage(details); 971 } 972 973 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) { 974 return rsWarner; 975 } 976 977 public InferenceContext inferenceContext() { 978 return deferredAttrContext.inferenceContext; 979 } 980 981 public DeferredAttrContext deferredAttrContext() { 982 return deferredAttrContext; 983 } 984 985 @Override 986 public String toString() { 987 return "MethodCheckContext"; 988 } 989 } 990 991 /** 992 * ResultInfo class to be used during method applicability checks. Check 993 * for deferred types goes through special path. 994 */ 995 class MethodResultInfo extends ResultInfo { 996 997 public MethodResultInfo(Type pt, CheckContext checkContext) { 998 attr.super(KindSelector.VAL, pt, checkContext); 999 } 1000 1001 @Override 1002 protected Type check(DiagnosticPosition pos, Type found) { 1003 if (found.hasTag(DEFERRED)) { 1004 DeferredType dt = (DeferredType)found; 1005 return dt.check(this); 1006 } else { 1007 Type uResult = U(found); 1008 Type capturedType = pos == null || pos.getTree() == null ? 1009 types.capture(uResult) : 1010 checkContext.inferenceContext() 1011 .cachedCapture(pos.getTree(), uResult, true); 1012 return super.check(pos, chk.checkNonVoid(pos, capturedType)); 1013 } 1014 } 1015 1016 /** 1017 * javac has a long-standing 'simplification' (see 6391995): 1018 * given an actual argument type, the method check is performed 1019 * on its upper bound. This leads to inconsistencies when an 1020 * argument type is checked against itself. For example, given 1021 * a type-variable T, it is not true that {@code U(T) <: T}, 1022 * so we need to guard against that. 1023 */ 1024 private Type U(Type found) { 1025 return found == pt ? 1026 found : types.cvarUpperBound(found); 1027 } 1028 1029 @Override 1030 protected MethodResultInfo dup(Type newPt) { 1031 return new MethodResultInfo(newPt, checkContext); 1032 } 1033 1034 @Override 1035 protected ResultInfo dup(CheckContext newContext) { 1036 return new MethodResultInfo(pt, newContext); 1037 } 1038 } 1039 1040 /** 1041 * Most specific method applicability routine. Given a list of actual types A, 1042 * a list of formal types F1, and a list of formal types F2, the routine determines 1043 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t. 1044 * argument types A. 1045 */ 1046 class MostSpecificCheck implements MethodCheck { 1047 1048 List<Type> actuals; 1049 1050 MostSpecificCheck(List<Type> actuals) { 1051 this.actuals = actuals; 1052 } 1053 1054 @Override 1055 public void argumentsAcceptable(final Env<AttrContext> env, 1056 DeferredAttrContext deferredAttrContext, 1057 List<Type> formals1, 1058 List<Type> formals2, 1059 Warner warn) { 1060 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired()); 1061 while (formals2.nonEmpty()) { 1062 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head); 1063 mresult.check(null, formals1.head); 1064 formals1 = formals1.tail; 1065 formals2 = formals2.tail; 1066 actuals = actuals.isEmpty() ? actuals : actuals.tail; 1067 } 1068 } 1069 1070 /** 1071 * Create a method check context to be used during the most specific applicability check 1072 */ 1073 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext, 1074 Warner rsWarner, Type actual) { 1075 return attr.new ResultInfo(KindSelector.VAL, to, 1076 new MostSpecificCheckContext(deferredAttrContext, rsWarner, actual)); 1077 } 1078 1079 /** 1080 * Subclass of method check context class that implements most specific 1081 * method conversion. If the actual type under analysis is a deferred type 1082 * a full blown structural analysis is carried out. 1083 */ 1084 class MostSpecificCheckContext extends MethodCheckContext { 1085 1086 Type actual; 1087 1088 public MostSpecificCheckContext(DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) { 1089 super(true, deferredAttrContext, rsWarner); 1090 this.actual = actual; 1091 } 1092 1093 public boolean compatible(Type found, Type req, Warner warn) { 1094 if (allowFunctionalInterfaceMostSpecific && 1095 unrelatedFunctionalInterfaces(found, req) && 1096 (actual != null && actual.getTag() == DEFERRED)) { 1097 DeferredType dt = (DeferredType) actual; 1098 DeferredType.SpeculativeCache.Entry e = 1099 dt.speculativeCache.get(deferredAttrContext.msym, deferredAttrContext.phase); 1100 if (e != null && e.speculativeTree != deferredAttr.stuckTree) { 1101 return functionalInterfaceMostSpecific(found, req, e.speculativeTree); 1102 } 1103 } 1104 return compatibleBySubtyping(found, req); 1105 } 1106 1107 private boolean compatibleBySubtyping(Type found, Type req) { 1108 if (!strict && found.isPrimitive() != req.isPrimitive()) { 1109 found = found.isPrimitive() ? types.boxedClass(found).type : types.unboxedType(found); 1110 } 1111 return types.isSubtypeNoCapture(found, deferredAttrContext.inferenceContext.asUndetVar(req)); 1112 } 1113 1114 /** Whether {@code t} and {@code s} are unrelated functional interface types. */ 1115 private boolean unrelatedFunctionalInterfaces(Type t, Type s) { 1116 return types.isFunctionalInterface(t.tsym) && 1117 types.isFunctionalInterface(s.tsym) && 1118 types.asSuper(t, s.tsym) == null && 1119 types.asSuper(s, t.tsym) == null; 1120 } 1121 1122 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */ 1123 private boolean functionalInterfaceMostSpecific(Type t, Type s, JCTree tree) { 1124 FunctionalInterfaceMostSpecificChecker msc = new FunctionalInterfaceMostSpecificChecker(t, s); 1125 msc.scan(tree); 1126 return msc.result; 1127 } 1128 1129 /** 1130 * Tests whether one functional interface type can be considered more specific 1131 * than another unrelated functional interface type for the scanned expression. 1132 */ 1133 class FunctionalInterfaceMostSpecificChecker extends DeferredAttr.PolyScanner { 1134 1135 final Type t; 1136 final Type s; 1137 boolean result; 1138 1139 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */ 1140 FunctionalInterfaceMostSpecificChecker(Type t, Type s) { 1141 this.t = t; 1142 this.s = s; 1143 result = true; 1144 } 1145 1146 @Override 1147 void skip(JCTree tree) { 1148 result &= false; 1149 } 1150 1151 @Override 1152 public void visitConditional(JCConditional tree) { 1153 scan(tree.truepart); 1154 scan(tree.falsepart); 1155 } 1156 1157 @Override 1158 public void visitReference(JCMemberReference tree) { 1159 Type desc_t = types.findDescriptorType(t); 1160 Type desc_s = types.findDescriptorType(s); 1161 // use inference variables here for more-specific inference (18.5.4) 1162 if (!types.isSameTypes(desc_t.getParameterTypes(), 1163 inferenceContext().asUndetVars(desc_s.getParameterTypes()))) { 1164 result &= false; 1165 } else { 1166 // compare return types 1167 Type ret_t = desc_t.getReturnType(); 1168 Type ret_s = desc_s.getReturnType(); 1169 if (ret_s.hasTag(VOID)) { 1170 result &= true; 1171 } else if (ret_t.hasTag(VOID)) { 1172 result &= false; 1173 } else if (ret_t.isPrimitive() != ret_s.isPrimitive()) { 1174 boolean retValIsPrimitive = 1175 tree.refPolyKind == PolyKind.STANDALONE && 1176 tree.sym.type.getReturnType().isPrimitive(); 1177 result &= (retValIsPrimitive == ret_t.isPrimitive()) && 1178 (retValIsPrimitive != ret_s.isPrimitive()); 1179 } else { 1180 result &= compatibleBySubtyping(ret_t, ret_s); 1181 } 1182 } 1183 } 1184 1185 @Override 1186 public void visitLambda(JCLambda tree) { 1187 Type desc_t = types.findDescriptorType(t); 1188 Type desc_s = types.findDescriptorType(s); 1189 // use inference variables here for more-specific inference (18.5.4) 1190 if (!types.isSameTypes(desc_t.getParameterTypes(), 1191 inferenceContext().asUndetVars(desc_s.getParameterTypes()))) { 1192 result &= false; 1193 } else { 1194 // compare return types 1195 Type ret_t = desc_t.getReturnType(); 1196 Type ret_s = desc_s.getReturnType(); 1197 if (ret_s.hasTag(VOID)) { 1198 result &= true; 1199 } else if (ret_t.hasTag(VOID)) { 1200 result &= false; 1201 } else if (unrelatedFunctionalInterfaces(ret_t, ret_s)) { 1202 for (JCExpression expr : lambdaResults(tree)) { 1203 result &= functionalInterfaceMostSpecific(ret_t, ret_s, expr); 1204 } 1205 } else if (ret_t.isPrimitive() != ret_s.isPrimitive()) { 1206 for (JCExpression expr : lambdaResults(tree)) { 1207 boolean retValIsPrimitive = expr.isStandalone() && expr.type.isPrimitive(); 1208 result &= (retValIsPrimitive == ret_t.isPrimitive()) && 1209 (retValIsPrimitive != ret_s.isPrimitive()); 1210 } 1211 } else { 1212 result &= compatibleBySubtyping(ret_t, ret_s); 1213 } 1214 } 1215 } 1216 //where 1217 1218 private List<JCExpression> lambdaResults(JCLambda lambda) { 1219 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) { 1220 return List.of((JCExpression) lambda.body); 1221 } else { 1222 final ListBuffer<JCExpression> buffer = new ListBuffer<>(); 1223 DeferredAttr.LambdaReturnScanner lambdaScanner = 1224 new DeferredAttr.LambdaReturnScanner() { 1225 @Override 1226 public void visitReturn(JCReturn tree) { 1227 if (tree.expr != null) { 1228 buffer.append(tree.expr); 1229 } 1230 } 1231 }; 1232 lambdaScanner.scan(lambda.body); 1233 return buffer.toList(); 1234 } 1235 } 1236 } 1237 1238 } 1239 1240 public MethodCheck mostSpecificCheck(List<Type> actuals) { 1241 Assert.error("Cannot get here!"); 1242 return null; 1243 } 1244 } 1245 1246 public static class InapplicableMethodException extends RuntimeException { 1247 private static final long serialVersionUID = 0; 1248 1249 JCDiagnostic diagnostic; 1250 JCDiagnostic.Factory diags; 1251 1252 InapplicableMethodException(JCDiagnostic.Factory diags) { 1253 this.diagnostic = null; 1254 this.diags = diags; 1255 } 1256 InapplicableMethodException setMessage() { 1257 return setMessage((JCDiagnostic)null); 1258 } 1259 InapplicableMethodException setMessage(String key) { 1260 return setMessage(key != null ? diags.fragment(key) : null); 1261 } 1262 InapplicableMethodException setMessage(String key, Object... args) { 1263 return setMessage(key != null ? diags.fragment(key, args) : null); 1264 } 1265 InapplicableMethodException setMessage(JCDiagnostic diag) { 1266 this.diagnostic = diag; 1267 return this; 1268 } 1269 1270 public JCDiagnostic getDiagnostic() { 1271 return diagnostic; 1272 } 1273 } 1274 private final InapplicableMethodException inapplicableMethodException; 1275 1276/* *************************************************************************** 1277 * Symbol lookup 1278 * the following naming conventions for arguments are used 1279 * 1280 * env is the environment where the symbol was mentioned 1281 * site is the type of which the symbol is a member 1282 * name is the symbol's name 1283 * if no arguments are given 1284 * argtypes are the value arguments, if we search for a method 1285 * 1286 * If no symbol was found, a ResolveError detailing the problem is returned. 1287 ****************************************************************************/ 1288 1289 /** Find field. Synthetic fields are always skipped. 1290 * @param env The current environment. 1291 * @param site The original type from where the selection takes place. 1292 * @param name The name of the field. 1293 * @param c The class to search for the field. This is always 1294 * a superclass or implemented interface of site's class. 1295 */ 1296 Symbol findField(Env<AttrContext> env, 1297 Type site, 1298 Name name, 1299 TypeSymbol c) { 1300 while (c.type.hasTag(TYPEVAR)) 1301 c = c.type.getUpperBound().tsym; 1302 Symbol bestSoFar = varNotFound; 1303 Symbol sym; 1304 for (Symbol s : c.members().getSymbolsByName(name)) { 1305 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) { 1306 return isAccessible(env, site, s) 1307 ? s : new AccessError(env, site, s); 1308 } 1309 } 1310 Type st = types.supertype(c.type); 1311 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) { 1312 sym = findField(env, site, name, st.tsym); 1313 bestSoFar = bestOf(bestSoFar, sym); 1314 } 1315 for (List<Type> l = types.interfaces(c.type); 1316 bestSoFar.kind != AMBIGUOUS && l.nonEmpty(); 1317 l = l.tail) { 1318 sym = findField(env, site, name, l.head.tsym); 1319 if (bestSoFar.exists() && sym.exists() && 1320 sym.owner != bestSoFar.owner) 1321 bestSoFar = new AmbiguityError(bestSoFar, sym); 1322 else 1323 bestSoFar = bestOf(bestSoFar, sym); 1324 } 1325 return bestSoFar; 1326 } 1327 1328 /** Resolve a field identifier, throw a fatal error if not found. 1329 * @param pos The position to use for error reporting. 1330 * @param env The environment current at the method invocation. 1331 * @param site The type of the qualifying expression, in which 1332 * identifier is searched. 1333 * @param name The identifier's name. 1334 */ 1335 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env, 1336 Type site, Name name) { 1337 Symbol sym = findField(env, site, name, site.tsym); 1338 if (sym.kind == VAR) return (VarSymbol)sym; 1339 else throw new FatalError( 1340 diags.fragment("fatal.err.cant.locate.field", 1341 name)); 1342 } 1343 1344 /** Find unqualified variable or field with given name. 1345 * Synthetic fields always skipped. 1346 * @param env The current environment. 1347 * @param name The name of the variable or field. 1348 */ 1349 Symbol findVar(Env<AttrContext> env, Name name) { 1350 Symbol bestSoFar = varNotFound; 1351 Env<AttrContext> env1 = env; 1352 boolean staticOnly = false; 1353 while (env1.outer != null) { 1354 Symbol sym = null; 1355 if (isStatic(env1)) staticOnly = true; 1356 for (Symbol s : env1.info.scope.getSymbolsByName(name)) { 1357 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) { 1358 sym = s; 1359 break; 1360 } 1361 } 1362 if (sym == null) { 1363 sym = findField(env1, env1.enclClass.sym.type, name, env1.enclClass.sym); 1364 } 1365 if (sym.exists()) { 1366 if (staticOnly && 1367 sym.kind == VAR && 1368 sym.owner.kind == TYP && 1369 (sym.flags() & STATIC) == 0) 1370 return new StaticError(sym); 1371 else 1372 return sym; 1373 } else { 1374 bestSoFar = bestOf(bestSoFar, sym); 1375 } 1376 1377 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true; 1378 env1 = env1.outer; 1379 } 1380 1381 Symbol sym = findField(env, syms.predefClass.type, name, syms.predefClass); 1382 if (sym.exists()) 1383 return sym; 1384 if (bestSoFar.exists()) 1385 return bestSoFar; 1386 1387 Symbol origin = null; 1388 for (Scope sc : new Scope[] { env.toplevel.namedImportScope, env.toplevel.starImportScope }) { 1389 for (Symbol currentSymbol : sc.getSymbolsByName(name)) { 1390 if (currentSymbol.kind != VAR) 1391 continue; 1392 // invariant: sym.kind == Symbol.Kind.VAR 1393 if (!bestSoFar.kind.isOverloadError() && 1394 currentSymbol.owner != bestSoFar.owner) 1395 return new AmbiguityError(bestSoFar, currentSymbol); 1396 else if (!bestSoFar.kind.betterThan(VAR)) { 1397 origin = sc.getOrigin(currentSymbol).owner; 1398 bestSoFar = isAccessible(env, origin.type, currentSymbol) 1399 ? currentSymbol : new AccessError(env, origin.type, currentSymbol); 1400 } 1401 } 1402 if (bestSoFar.exists()) break; 1403 } 1404 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type) 1405 return bestSoFar.clone(origin); 1406 else 1407 return bestSoFar; 1408 } 1409 1410 Warner noteWarner = new Warner(); 1411 1412 /** Select the best method for a call site among two choices. 1413 * @param env The current environment. 1414 * @param site The original type from where the 1415 * selection takes place. 1416 * @param argtypes The invocation's value arguments, 1417 * @param typeargtypes The invocation's type arguments, 1418 * @param sym Proposed new best match. 1419 * @param bestSoFar Previously found best match. 1420 * @param allowBoxing Allow boxing conversions of arguments. 1421 * @param useVarargs Box trailing arguments into an array for varargs. 1422 */ 1423 @SuppressWarnings("fallthrough") 1424 Symbol selectBest(Env<AttrContext> env, 1425 Type site, 1426 List<Type> argtypes, 1427 List<Type> typeargtypes, 1428 Symbol sym, 1429 Symbol bestSoFar, 1430 boolean allowBoxing, 1431 boolean useVarargs) { 1432 if (sym.kind == ERR || 1433 !sym.isInheritedIn(site.tsym, types)) { 1434 return bestSoFar; 1435 } else if (useVarargs && (sym.flags() & VARARGS) == 0) { 1436 return bestSoFar.kind.isOverloadError() ? 1437 new BadVarargsMethod((ResolveError)bestSoFar.baseSymbol()) : 1438 bestSoFar; 1439 } 1440 Assert.check(!sym.kind.isOverloadError()); 1441 try { 1442 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes, 1443 allowBoxing, useVarargs, types.noWarnings); 1444 currentResolutionContext.addApplicableCandidate(sym, mt); 1445 } catch (InapplicableMethodException ex) { 1446 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic()); 1447 switch (bestSoFar.kind) { 1448 case ABSENT_MTH: 1449 return new InapplicableSymbolError(currentResolutionContext); 1450 case WRONG_MTH: 1451 bestSoFar = new InapplicableSymbolsError(currentResolutionContext); 1452 default: 1453 return bestSoFar; 1454 } 1455 } 1456 if (!isAccessible(env, site, sym)) { 1457 return (bestSoFar.kind == ABSENT_MTH) 1458 ? new AccessError(env, site, sym) 1459 : bestSoFar; 1460 } 1461 return (bestSoFar.kind.isOverloadError() && bestSoFar.kind != AMBIGUOUS) 1462 ? sym 1463 : mostSpecific(argtypes, sym, bestSoFar, env, site, useVarargs); 1464 } 1465 1466 /* Return the most specific of the two methods for a call, 1467 * given that both are accessible and applicable. 1468 * @param m1 A new candidate for most specific. 1469 * @param m2 The previous most specific candidate. 1470 * @param env The current environment. 1471 * @param site The original type from where the selection 1472 * takes place. 1473 * @param allowBoxing Allow boxing conversions of arguments. 1474 * @param useVarargs Box trailing arguments into an array for varargs. 1475 */ 1476 Symbol mostSpecific(List<Type> argtypes, Symbol m1, 1477 Symbol m2, 1478 Env<AttrContext> env, 1479 final Type site, 1480 boolean useVarargs) { 1481 switch (m2.kind) { 1482 case MTH: 1483 if (m1 == m2) return m1; 1484 boolean m1SignatureMoreSpecific = 1485 signatureMoreSpecific(argtypes, env, site, m1, m2, useVarargs); 1486 boolean m2SignatureMoreSpecific = 1487 signatureMoreSpecific(argtypes, env, site, m2, m1, useVarargs); 1488 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) { 1489 Type mt1 = types.memberType(site, m1); 1490 Type mt2 = types.memberType(site, m2); 1491 if (!types.overrideEquivalent(mt1, mt2)) 1492 return ambiguityError(m1, m2); 1493 1494 // same signature; select (a) the non-bridge method, or 1495 // (b) the one that overrides the other, or (c) the concrete 1496 // one, or (d) merge both abstract signatures 1497 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE)) 1498 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1; 1499 1500 // if one overrides or hides the other, use it 1501 TypeSymbol m1Owner = (TypeSymbol)m1.owner; 1502 TypeSymbol m2Owner = (TypeSymbol)m2.owner; 1503 if (types.asSuper(m1Owner.type, m2Owner) != null && 1504 ((m1.owner.flags_field & INTERFACE) == 0 || 1505 (m2.owner.flags_field & INTERFACE) != 0) && 1506 m1.overrides(m2, m1Owner, types, false)) 1507 return m1; 1508 if (types.asSuper(m2Owner.type, m1Owner) != null && 1509 ((m2.owner.flags_field & INTERFACE) == 0 || 1510 (m1.owner.flags_field & INTERFACE) != 0) && 1511 m2.overrides(m1, m2Owner, types, false)) 1512 return m2; 1513 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0; 1514 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0; 1515 if (m1Abstract && !m2Abstract) return m2; 1516 if (m2Abstract && !m1Abstract) return m1; 1517 // both abstract or both concrete 1518 return ambiguityError(m1, m2); 1519 } 1520 if (m1SignatureMoreSpecific) return m1; 1521 if (m2SignatureMoreSpecific) return m2; 1522 return ambiguityError(m1, m2); 1523 case AMBIGUOUS: 1524 //compare m1 to ambiguous methods in m2 1525 AmbiguityError e = (AmbiguityError)m2.baseSymbol(); 1526 boolean m1MoreSpecificThanAnyAmbiguous = true; 1527 boolean allAmbiguousMoreSpecificThanM1 = true; 1528 for (Symbol s : e.ambiguousSyms) { 1529 Symbol moreSpecific = mostSpecific(argtypes, m1, s, env, site, useVarargs); 1530 m1MoreSpecificThanAnyAmbiguous &= moreSpecific == m1; 1531 allAmbiguousMoreSpecificThanM1 &= moreSpecific == s; 1532 } 1533 if (m1MoreSpecificThanAnyAmbiguous) 1534 return m1; 1535 //if m1 is more specific than some ambiguous methods, but other ambiguous methods are 1536 //more specific than m1, add it as a new ambiguous method: 1537 if (!allAmbiguousMoreSpecificThanM1) 1538 e.addAmbiguousSymbol(m1); 1539 return e; 1540 default: 1541 throw new AssertionError(); 1542 } 1543 } 1544 //where 1545 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean useVarargs) { 1546 noteWarner.clear(); 1547 int maxLength = Math.max( 1548 Math.max(m1.type.getParameterTypes().length(), actuals.length()), 1549 m2.type.getParameterTypes().length()); 1550 MethodResolutionContext prevResolutionContext = currentResolutionContext; 1551 try { 1552 currentResolutionContext = new MethodResolutionContext(); 1553 currentResolutionContext.step = prevResolutionContext.step; 1554 currentResolutionContext.methodCheck = 1555 prevResolutionContext.methodCheck.mostSpecificCheck(actuals); 1556 Type mst = instantiate(env, site, m2, null, 1557 adjustArgs(types.cvarLowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null, 1558 false, useVarargs, noteWarner); 1559 return mst != null && 1560 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED); 1561 } finally { 1562 currentResolutionContext = prevResolutionContext; 1563 } 1564 } 1565 1566 List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) { 1567 if ((msym.flags() & VARARGS) != 0 && allowVarargs) { 1568 Type varargsElem = types.elemtype(args.last()); 1569 if (varargsElem == null) { 1570 Assert.error("Bad varargs = " + args.last() + " " + msym); 1571 } 1572 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse(); 1573 while (newArgs.length() < length) { 1574 newArgs = newArgs.append(newArgs.last()); 1575 } 1576 return newArgs; 1577 } else { 1578 return args; 1579 } 1580 } 1581 //where 1582 Type mostSpecificReturnType(Type mt1, Type mt2) { 1583 Type rt1 = mt1.getReturnType(); 1584 Type rt2 = mt2.getReturnType(); 1585 1586 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL)) { 1587 //if both are generic methods, adjust return type ahead of subtyping check 1588 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments()); 1589 } 1590 //first use subtyping, then return type substitutability 1591 if (types.isSubtype(rt1, rt2)) { 1592 return mt1; 1593 } else if (types.isSubtype(rt2, rt1)) { 1594 return mt2; 1595 } else if (types.returnTypeSubstitutable(mt1, mt2)) { 1596 return mt1; 1597 } else if (types.returnTypeSubstitutable(mt2, mt1)) { 1598 return mt2; 1599 } else { 1600 return null; 1601 } 1602 } 1603 //where 1604 Symbol ambiguityError(Symbol m1, Symbol m2) { 1605 if (((m1.flags() | m2.flags()) & CLASH) != 0) { 1606 return (m1.flags() & CLASH) == 0 ? m1 : m2; 1607 } else { 1608 return new AmbiguityError(m1, m2); 1609 } 1610 } 1611 1612 Symbol findMethodInScope(Env<AttrContext> env, 1613 Type site, 1614 Name name, 1615 List<Type> argtypes, 1616 List<Type> typeargtypes, 1617 Scope sc, 1618 Symbol bestSoFar, 1619 boolean allowBoxing, 1620 boolean useVarargs, 1621 boolean abstractok) { 1622 for (Symbol s : sc.getSymbolsByName(name, new LookupFilter(abstractok))) { 1623 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s, 1624 bestSoFar, allowBoxing, useVarargs); 1625 } 1626 return bestSoFar; 1627 } 1628 //where 1629 class LookupFilter implements Filter<Symbol> { 1630 1631 boolean abstractOk; 1632 1633 LookupFilter(boolean abstractOk) { 1634 this.abstractOk = abstractOk; 1635 } 1636 1637 public boolean accepts(Symbol s) { 1638 long flags = s.flags(); 1639 return s.kind == MTH && 1640 (flags & SYNTHETIC) == 0 && 1641 (abstractOk || 1642 (flags & DEFAULT) != 0 || 1643 (flags & ABSTRACT) == 0); 1644 } 1645 } 1646 1647 /** Find best qualified method matching given name, type and value 1648 * arguments. 1649 * @param env The current environment. 1650 * @param site The original type from where the selection 1651 * takes place. 1652 * @param name The method's name. 1653 * @param argtypes The method's value arguments. 1654 * @param typeargtypes The method's type arguments 1655 * @param allowBoxing Allow boxing conversions of arguments. 1656 * @param useVarargs Box trailing arguments into an array for varargs. 1657 */ 1658 Symbol findMethod(Env<AttrContext> env, 1659 Type site, 1660 Name name, 1661 List<Type> argtypes, 1662 List<Type> typeargtypes, 1663 boolean allowBoxing, 1664 boolean useVarargs) { 1665 Symbol bestSoFar = methodNotFound; 1666 bestSoFar = findMethod(env, 1667 site, 1668 name, 1669 argtypes, 1670 typeargtypes, 1671 site.tsym.type, 1672 bestSoFar, 1673 allowBoxing, 1674 useVarargs); 1675 return bestSoFar; 1676 } 1677 // where 1678 private Symbol findMethod(Env<AttrContext> env, 1679 Type site, 1680 Name name, 1681 List<Type> argtypes, 1682 List<Type> typeargtypes, 1683 Type intype, 1684 Symbol bestSoFar, 1685 boolean allowBoxing, 1686 boolean useVarargs) { 1687 @SuppressWarnings({"unchecked","rawtypes"}) 1688 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() }; 1689 1690 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK; 1691 for (TypeSymbol s : superclasses(intype)) { 1692 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes, 1693 s.members(), bestSoFar, allowBoxing, useVarargs, true); 1694 if (name == names.init) return bestSoFar; 1695 iphase = (iphase == null) ? null : iphase.update(s, this); 1696 if (iphase != null) { 1697 for (Type itype : types.interfaces(s.type)) { 1698 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]); 1699 } 1700 } 1701 } 1702 1703 Symbol concrete = bestSoFar.kind.isValid() && 1704 (bestSoFar.flags() & ABSTRACT) == 0 ? 1705 bestSoFar : methodNotFound; 1706 1707 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) { 1708 //keep searching for abstract methods 1709 for (Type itype : itypes[iphase2.ordinal()]) { 1710 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure()) 1711 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK && 1712 (itype.tsym.flags() & DEFAULT) == 0) continue; 1713 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes, 1714 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, true); 1715 if (concrete != bestSoFar && 1716 concrete.kind.isValid() && 1717 bestSoFar.kind.isValid() && 1718 types.isSubSignature(concrete.type, bestSoFar.type)) { 1719 //this is an hack - as javac does not do full membership checks 1720 //most specific ends up comparing abstract methods that might have 1721 //been implemented by some concrete method in a subclass and, 1722 //because of raw override, it is possible for an abstract method 1723 //to be more specific than the concrete method - so we need 1724 //to explicitly call that out (see CR 6178365) 1725 bestSoFar = concrete; 1726 } 1727 } 1728 } 1729 return bestSoFar; 1730 } 1731 1732 enum InterfaceLookupPhase { 1733 ABSTRACT_OK() { 1734 @Override 1735 InterfaceLookupPhase update(Symbol s, Resolve rs) { 1736 //We should not look for abstract methods if receiver is a concrete class 1737 //(as concrete classes are expected to implement all abstracts coming 1738 //from superinterfaces) 1739 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) { 1740 return this; 1741 } else { 1742 return DEFAULT_OK; 1743 } 1744 } 1745 }, 1746 DEFAULT_OK() { 1747 @Override 1748 InterfaceLookupPhase update(Symbol s, Resolve rs) { 1749 return this; 1750 } 1751 }; 1752 1753 abstract InterfaceLookupPhase update(Symbol s, Resolve rs); 1754 } 1755 1756 /** 1757 * Return an Iterable object to scan the superclasses of a given type. 1758 * It's crucial that the scan is done lazily, as we don't want to accidentally 1759 * access more supertypes than strictly needed (as this could trigger completion 1760 * errors if some of the not-needed supertypes are missing/ill-formed). 1761 */ 1762 Iterable<TypeSymbol> superclasses(final Type intype) { 1763 return new Iterable<TypeSymbol>() { 1764 public Iterator<TypeSymbol> iterator() { 1765 return new Iterator<TypeSymbol>() { 1766 1767 List<TypeSymbol> seen = List.nil(); 1768 TypeSymbol currentSym = symbolFor(intype); 1769 TypeSymbol prevSym = null; 1770 1771 public boolean hasNext() { 1772 if (currentSym == syms.noSymbol) { 1773 currentSym = symbolFor(types.supertype(prevSym.type)); 1774 } 1775 return currentSym != null; 1776 } 1777 1778 public TypeSymbol next() { 1779 prevSym = currentSym; 1780 currentSym = syms.noSymbol; 1781 Assert.check(prevSym != null || prevSym != syms.noSymbol); 1782 return prevSym; 1783 } 1784 1785 public void remove() { 1786 throw new UnsupportedOperationException(); 1787 } 1788 1789 TypeSymbol symbolFor(Type t) { 1790 if (!t.hasTag(CLASS) && 1791 !t.hasTag(TYPEVAR)) { 1792 return null; 1793 } 1794 while (t.hasTag(TYPEVAR)) 1795 t = t.getUpperBound(); 1796 if (seen.contains(t.tsym)) { 1797 //degenerate case in which we have a circular 1798 //class hierarchy - because of ill-formed classfiles 1799 return null; 1800 } 1801 seen = seen.prepend(t.tsym); 1802 return t.tsym; 1803 } 1804 }; 1805 } 1806 }; 1807 } 1808 1809 /** Find unqualified method matching given name, type and value arguments. 1810 * @param env The current environment. 1811 * @param name The method's name. 1812 * @param argtypes The method's value arguments. 1813 * @param typeargtypes The method's type arguments. 1814 * @param allowBoxing Allow boxing conversions of arguments. 1815 * @param useVarargs Box trailing arguments into an array for varargs. 1816 */ 1817 Symbol findFun(Env<AttrContext> env, Name name, 1818 List<Type> argtypes, List<Type> typeargtypes, 1819 boolean allowBoxing, boolean useVarargs) { 1820 Symbol bestSoFar = methodNotFound; 1821 Env<AttrContext> env1 = env; 1822 boolean staticOnly = false; 1823 while (env1.outer != null) { 1824 if (isStatic(env1)) staticOnly = true; 1825 Symbol sym = findMethod( 1826 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes, 1827 allowBoxing, useVarargs); 1828 if (sym.exists()) { 1829 if (staticOnly && 1830 sym.kind == MTH && 1831 sym.owner.kind == TYP && 1832 (sym.flags() & STATIC) == 0) return new StaticError(sym); 1833 else return sym; 1834 } else { 1835 bestSoFar = bestOf(bestSoFar, sym); 1836 } 1837 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true; 1838 env1 = env1.outer; 1839 } 1840 1841 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes, 1842 typeargtypes, allowBoxing, useVarargs); 1843 if (sym.exists()) 1844 return sym; 1845 1846 for (Symbol currentSym : env.toplevel.namedImportScope.getSymbolsByName(name)) { 1847 Symbol origin = env.toplevel.namedImportScope.getOrigin(currentSym).owner; 1848 if (currentSym.kind == MTH) { 1849 if (currentSym.owner.type != origin.type) 1850 currentSym = currentSym.clone(origin); 1851 if (!isAccessible(env, origin.type, currentSym)) 1852 currentSym = new AccessError(env, origin.type, currentSym); 1853 bestSoFar = selectBest(env, origin.type, 1854 argtypes, typeargtypes, 1855 currentSym, bestSoFar, 1856 allowBoxing, useVarargs); 1857 } 1858 } 1859 if (bestSoFar.exists()) 1860 return bestSoFar; 1861 1862 for (Symbol currentSym : env.toplevel.starImportScope.getSymbolsByName(name)) { 1863 Symbol origin = env.toplevel.starImportScope.getOrigin(currentSym).owner; 1864 if (currentSym.kind == MTH) { 1865 if (currentSym.owner.type != origin.type) 1866 currentSym = currentSym.clone(origin); 1867 if (!isAccessible(env, origin.type, currentSym)) 1868 currentSym = new AccessError(env, origin.type, currentSym); 1869 bestSoFar = selectBest(env, origin.type, 1870 argtypes, typeargtypes, 1871 currentSym, bestSoFar, 1872 allowBoxing, useVarargs); 1873 } 1874 } 1875 return bestSoFar; 1876 } 1877 1878 /** Load toplevel or member class with given fully qualified name and 1879 * verify that it is accessible. 1880 * @param env The current environment. 1881 * @param name The fully qualified name of the class to be loaded. 1882 */ 1883 Symbol loadClass(Env<AttrContext> env, Name name) { 1884 try { 1885 ClassSymbol c = finder.loadClass(name); 1886 return isAccessible(env, c) ? c : new AccessError(c); 1887 } catch (ClassFinder.BadClassFile err) { 1888 throw err; 1889 } catch (CompletionFailure ex) { 1890 return typeNotFound; 1891 } 1892 } 1893 1894 1895 /** 1896 * Find a type declared in a scope (not inherited). Return null 1897 * if none is found. 1898 * @param env The current environment. 1899 * @param site The original type from where the selection takes 1900 * place. 1901 * @param name The type's name. 1902 * @param c The class to search for the member type. This is 1903 * always a superclass or implemented interface of 1904 * site's class. 1905 */ 1906 Symbol findImmediateMemberType(Env<AttrContext> env, 1907 Type site, 1908 Name name, 1909 TypeSymbol c) { 1910 for (Symbol sym : c.members().getSymbolsByName(name)) { 1911 if (sym.kind == TYP) { 1912 return isAccessible(env, site, sym) 1913 ? sym 1914 : new AccessError(env, site, sym); 1915 } 1916 } 1917 return typeNotFound; 1918 } 1919 1920 /** Find a member type inherited from a superclass or interface. 1921 * @param env The current environment. 1922 * @param site The original type from where the selection takes 1923 * place. 1924 * @param name The type's name. 1925 * @param c The class to search for the member type. This is 1926 * always a superclass or implemented interface of 1927 * site's class. 1928 */ 1929 Symbol findInheritedMemberType(Env<AttrContext> env, 1930 Type site, 1931 Name name, 1932 TypeSymbol c) { 1933 Symbol bestSoFar = typeNotFound; 1934 Symbol sym; 1935 Type st = types.supertype(c.type); 1936 if (st != null && st.hasTag(CLASS)) { 1937 sym = findMemberType(env, site, name, st.tsym); 1938 bestSoFar = bestOf(bestSoFar, sym); 1939 } 1940 for (List<Type> l = types.interfaces(c.type); 1941 bestSoFar.kind != AMBIGUOUS && l.nonEmpty(); 1942 l = l.tail) { 1943 sym = findMemberType(env, site, name, l.head.tsym); 1944 if (!bestSoFar.kind.isOverloadError() && 1945 !sym.kind.isOverloadError() && 1946 sym.owner != bestSoFar.owner) 1947 bestSoFar = new AmbiguityError(bestSoFar, sym); 1948 else 1949 bestSoFar = bestOf(bestSoFar, sym); 1950 } 1951 return bestSoFar; 1952 } 1953 1954 /** Find qualified member type. 1955 * @param env The current environment. 1956 * @param site The original type from where the selection takes 1957 * place. 1958 * @param name The type's name. 1959 * @param c The class to search for the member type. This is 1960 * always a superclass or implemented interface of 1961 * site's class. 1962 */ 1963 Symbol findMemberType(Env<AttrContext> env, 1964 Type site, 1965 Name name, 1966 TypeSymbol c) { 1967 Symbol sym = findImmediateMemberType(env, site, name, c); 1968 1969 if (sym != typeNotFound) 1970 return sym; 1971 1972 return findInheritedMemberType(env, site, name, c); 1973 1974 } 1975 1976 /** Find a global type in given scope and load corresponding class. 1977 * @param env The current environment. 1978 * @param scope The scope in which to look for the type. 1979 * @param name The type's name. 1980 */ 1981 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) { 1982 Symbol bestSoFar = typeNotFound; 1983 for (Symbol s : scope.getSymbolsByName(name)) { 1984 Symbol sym = loadClass(env, s.flatName()); 1985 if (bestSoFar.kind == TYP && sym.kind == TYP && 1986 bestSoFar != sym) 1987 return new AmbiguityError(bestSoFar, sym); 1988 else 1989 bestSoFar = bestOf(bestSoFar, sym); 1990 } 1991 return bestSoFar; 1992 } 1993 1994 Symbol findTypeVar(Env<AttrContext> env, Name name, boolean staticOnly) { 1995 for (Symbol sym : env.info.scope.getSymbolsByName(name)) { 1996 if (sym.kind == TYP) { 1997 if (staticOnly && 1998 sym.type.hasTag(TYPEVAR) && 1999 sym.owner.kind == TYP) 2000 return new StaticError(sym); 2001 return sym; 2002 } 2003 } 2004 return typeNotFound; 2005 } 2006 2007 /** Find an unqualified type symbol. 2008 * @param env The current environment. 2009 * @param name The type's name. 2010 */ 2011 Symbol findType(Env<AttrContext> env, Name name) { 2012 Symbol bestSoFar = typeNotFound; 2013 Symbol sym; 2014 boolean staticOnly = false; 2015 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) { 2016 if (isStatic(env1)) staticOnly = true; 2017 // First, look for a type variable and the first member type 2018 final Symbol tyvar = findTypeVar(env1, name, staticOnly); 2019 sym = findImmediateMemberType(env1, env1.enclClass.sym.type, 2020 name, env1.enclClass.sym); 2021 2022 // Return the type variable if we have it, and have no 2023 // immediate member, OR the type variable is for a method. 2024 if (tyvar != typeNotFound) { 2025 if (env.baseClause || sym == typeNotFound || 2026 (tyvar.kind == TYP && tyvar.exists() && 2027 tyvar.owner.kind == MTH)) { 2028 return tyvar; 2029 } 2030 } 2031 2032 // If the environment is a class def, finish up, 2033 // otherwise, do the entire findMemberType 2034 if (sym == typeNotFound) 2035 sym = findInheritedMemberType(env1, env1.enclClass.sym.type, 2036 name, env1.enclClass.sym); 2037 2038 if (staticOnly && sym.kind == TYP && 2039 sym.type.hasTag(CLASS) && 2040 sym.type.getEnclosingType().hasTag(CLASS) && 2041 env1.enclClass.sym.type.isParameterized() && 2042 sym.type.getEnclosingType().isParameterized()) 2043 return new StaticError(sym); 2044 else if (sym.exists()) return sym; 2045 else bestSoFar = bestOf(bestSoFar, sym); 2046 2047 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass; 2048 if ((encl.sym.flags() & STATIC) != 0) 2049 staticOnly = true; 2050 } 2051 2052 if (!env.tree.hasTag(IMPORT)) { 2053 sym = findGlobalType(env, env.toplevel.namedImportScope, name); 2054 if (sym.exists()) return sym; 2055 else bestSoFar = bestOf(bestSoFar, sym); 2056 2057 sym = findGlobalType(env, env.toplevel.packge.members(), name); 2058 if (sym.exists()) return sym; 2059 else bestSoFar = bestOf(bestSoFar, sym); 2060 2061 sym = findGlobalType(env, env.toplevel.starImportScope, name); 2062 if (sym.exists()) return sym; 2063 else bestSoFar = bestOf(bestSoFar, sym); 2064 } 2065 2066 return bestSoFar; 2067 } 2068 2069 /** Find an unqualified identifier which matches a specified kind set. 2070 * @param env The current environment. 2071 * @param name The identifier's name. 2072 * @param kind Indicates the possible symbol kinds 2073 * (a subset of VAL, TYP, PCK). 2074 */ 2075 Symbol findIdent(Env<AttrContext> env, Name name, KindSelector kind) { 2076 Symbol bestSoFar = typeNotFound; 2077 Symbol sym; 2078 2079 if (kind.contains(KindSelector.VAL)) { 2080 sym = findVar(env, name); 2081 if (sym.exists()) return sym; 2082 else bestSoFar = bestOf(bestSoFar, sym); 2083 } 2084 2085 if (kind.contains(KindSelector.TYP)) { 2086 sym = findType(env, name); 2087 2088 if (sym.exists()) return sym; 2089 else bestSoFar = bestOf(bestSoFar, sym); 2090 } 2091 2092 if (kind.contains(KindSelector.PCK)) 2093 return syms.enterPackage(name); 2094 else return bestSoFar; 2095 } 2096 2097 /** Find an identifier in a package which matches a specified kind set. 2098 * @param env The current environment. 2099 * @param name The identifier's name. 2100 * @param kind Indicates the possible symbol kinds 2101 * (a nonempty subset of TYP, PCK). 2102 */ 2103 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck, 2104 Name name, KindSelector kind) { 2105 Name fullname = TypeSymbol.formFullName(name, pck); 2106 Symbol bestSoFar = typeNotFound; 2107 PackageSymbol pack = null; 2108 if (kind.contains(KindSelector.PCK)) { 2109 pack = syms.enterPackage(fullname); 2110 if (pack.exists()) return pack; 2111 } 2112 if (kind.contains(KindSelector.TYP)) { 2113 Symbol sym = loadClass(env, fullname); 2114 if (sym.exists()) { 2115 // don't allow programs to use flatnames 2116 if (name == sym.name) return sym; 2117 } 2118 else bestSoFar = bestOf(bestSoFar, sym); 2119 } 2120 return (pack != null) ? pack : bestSoFar; 2121 } 2122 2123 /** Find an identifier among the members of a given type `site'. 2124 * @param env The current environment. 2125 * @param site The type containing the symbol to be found. 2126 * @param name The identifier's name. 2127 * @param kind Indicates the possible symbol kinds 2128 * (a subset of VAL, TYP). 2129 */ 2130 Symbol findIdentInType(Env<AttrContext> env, Type site, 2131 Name name, KindSelector kind) { 2132 Symbol bestSoFar = typeNotFound; 2133 Symbol sym; 2134 if (kind.contains(KindSelector.VAL)) { 2135 sym = findField(env, site, name, site.tsym); 2136 if (sym.exists()) return sym; 2137 else bestSoFar = bestOf(bestSoFar, sym); 2138 } 2139 2140 if (kind.contains(KindSelector.TYP)) { 2141 sym = findMemberType(env, site, name, site.tsym); 2142 if (sym.exists()) return sym; 2143 else bestSoFar = bestOf(bestSoFar, sym); 2144 } 2145 return bestSoFar; 2146 } 2147 2148/* *************************************************************************** 2149 * Access checking 2150 * The following methods convert ResolveErrors to ErrorSymbols, issuing 2151 * an error message in the process 2152 ****************************************************************************/ 2153 2154 /** If `sym' is a bad symbol: report error and return errSymbol 2155 * else pass through unchanged, 2156 * additional arguments duplicate what has been used in trying to find the 2157 * symbol {@literal (--> flyweight pattern)}. This improves performance since we 2158 * expect misses to happen frequently. 2159 * 2160 * @param sym The symbol that was found, or a ResolveError. 2161 * @param pos The position to use for error reporting. 2162 * @param location The symbol the served as a context for this lookup 2163 * @param site The original type from where the selection took place. 2164 * @param name The symbol's name. 2165 * @param qualified Did we get here through a qualified expression resolution? 2166 * @param argtypes The invocation's value arguments, 2167 * if we looked for a method. 2168 * @param typeargtypes The invocation's type arguments, 2169 * if we looked for a method. 2170 * @param logResolveHelper helper class used to log resolve errors 2171 */ 2172 Symbol accessInternal(Symbol sym, 2173 DiagnosticPosition pos, 2174 Symbol location, 2175 Type site, 2176 Name name, 2177 boolean qualified, 2178 List<Type> argtypes, 2179 List<Type> typeargtypes, 2180 LogResolveHelper logResolveHelper) { 2181 if (sym.kind.isOverloadError()) { 2182 ResolveError errSym = (ResolveError)sym.baseSymbol(); 2183 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol); 2184 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes); 2185 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) { 2186 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes); 2187 } 2188 } 2189 return sym; 2190 } 2191 2192 /** 2193 * Variant of the generalized access routine, to be used for generating method 2194 * resolution diagnostics 2195 */ 2196 Symbol accessMethod(Symbol sym, 2197 DiagnosticPosition pos, 2198 Symbol location, 2199 Type site, 2200 Name name, 2201 boolean qualified, 2202 List<Type> argtypes, 2203 List<Type> typeargtypes) { 2204 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper); 2205 } 2206 2207 /** Same as original accessMethod(), but without location. 2208 */ 2209 Symbol accessMethod(Symbol sym, 2210 DiagnosticPosition pos, 2211 Type site, 2212 Name name, 2213 boolean qualified, 2214 List<Type> argtypes, 2215 List<Type> typeargtypes) { 2216 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes); 2217 } 2218 2219 /** 2220 * Variant of the generalized access routine, to be used for generating variable, 2221 * type resolution diagnostics 2222 */ 2223 Symbol accessBase(Symbol sym, 2224 DiagnosticPosition pos, 2225 Symbol location, 2226 Type site, 2227 Name name, 2228 boolean qualified) { 2229 return accessInternal(sym, pos, location, site, name, qualified, List.<Type>nil(), null, basicLogResolveHelper); 2230 } 2231 2232 /** Same as original accessBase(), but without location. 2233 */ 2234 Symbol accessBase(Symbol sym, 2235 DiagnosticPosition pos, 2236 Type site, 2237 Name name, 2238 boolean qualified) { 2239 return accessBase(sym, pos, site.tsym, site, name, qualified); 2240 } 2241 2242 interface LogResolveHelper { 2243 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes); 2244 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes); 2245 } 2246 2247 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() { 2248 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) { 2249 return !site.isErroneous(); 2250 } 2251 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) { 2252 return argtypes; 2253 } 2254 }; 2255 2256 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() { 2257 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) { 2258 return !site.isErroneous() && 2259 !Type.isErroneous(argtypes) && 2260 (typeargtypes == null || !Type.isErroneous(typeargtypes)); 2261 } 2262 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) { 2263 return Type.map(argtypes, new ResolveDeferredRecoveryMap(AttrMode.SPECULATIVE, accessedSym, currentResolutionContext.step)); 2264 } 2265 }; 2266 2267 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap { 2268 2269 public ResolveDeferredRecoveryMap(AttrMode mode, Symbol msym, MethodResolutionPhase step) { 2270 deferredAttr.super(mode, msym, step); 2271 } 2272 2273 @Override 2274 protected Type typeOf(DeferredType dt) { 2275 Type res = super.typeOf(dt); 2276 if (!res.isErroneous()) { 2277 switch (TreeInfo.skipParens(dt.tree).getTag()) { 2278 case LAMBDA: 2279 case REFERENCE: 2280 return dt; 2281 case CONDEXPR: 2282 return res == Type.recoveryType ? 2283 dt : res; 2284 } 2285 } 2286 return res; 2287 } 2288 } 2289 2290 /** Check that sym is not an abstract method. 2291 */ 2292 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) { 2293 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0) 2294 log.error(pos, "abstract.cant.be.accessed.directly", 2295 kindName(sym), sym, sym.location()); 2296 } 2297 2298/* *************************************************************************** 2299 * Name resolution 2300 * Naming conventions are as for symbol lookup 2301 * Unlike the find... methods these methods will report access errors 2302 ****************************************************************************/ 2303 2304 /** Resolve an unqualified (non-method) identifier. 2305 * @param pos The position to use for error reporting. 2306 * @param env The environment current at the identifier use. 2307 * @param name The identifier's name. 2308 * @param kind The set of admissible symbol kinds for the identifier. 2309 */ 2310 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env, 2311 Name name, KindSelector kind) { 2312 return accessBase( 2313 findIdent(env, name, kind), 2314 pos, env.enclClass.sym.type, name, false); 2315 } 2316 2317 /** Resolve an unqualified method identifier. 2318 * @param pos The position to use for error reporting. 2319 * @param env The environment current at the method invocation. 2320 * @param name The identifier's name. 2321 * @param argtypes The types of the invocation's value arguments. 2322 * @param typeargtypes The types of the invocation's type arguments. 2323 */ 2324 Symbol resolveMethod(DiagnosticPosition pos, 2325 Env<AttrContext> env, 2326 Name name, 2327 List<Type> argtypes, 2328 List<Type> typeargtypes) { 2329 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck, 2330 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) { 2331 @Override 2332 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2333 return findFun(env, name, argtypes, typeargtypes, 2334 phase.isBoxingRequired(), 2335 phase.isVarargsRequired()); 2336 }}); 2337 } 2338 2339 /** Resolve a qualified method identifier 2340 * @param pos The position to use for error reporting. 2341 * @param env The environment current at the method invocation. 2342 * @param site The type of the qualifying expression, in which 2343 * identifier is searched. 2344 * @param name The identifier's name. 2345 * @param argtypes The types of the invocation's value arguments. 2346 * @param typeargtypes The types of the invocation's type arguments. 2347 */ 2348 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env, 2349 Type site, Name name, List<Type> argtypes, 2350 List<Type> typeargtypes) { 2351 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes); 2352 } 2353 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env, 2354 Symbol location, Type site, Name name, List<Type> argtypes, 2355 List<Type> typeargtypes) { 2356 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes); 2357 } 2358 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext, 2359 DiagnosticPosition pos, Env<AttrContext> env, 2360 Symbol location, Type site, Name name, List<Type> argtypes, 2361 List<Type> typeargtypes) { 2362 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) { 2363 @Override 2364 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2365 return findMethod(env, site, name, argtypes, typeargtypes, 2366 phase.isBoxingRequired(), 2367 phase.isVarargsRequired()); 2368 } 2369 @Override 2370 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 2371 if (sym.kind.isOverloadError()) { 2372 sym = super.access(env, pos, location, sym); 2373 } else if (allowMethodHandles) { 2374 MethodSymbol msym = (MethodSymbol)sym; 2375 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) { 2376 return findPolymorphicSignatureInstance(env, sym, argtypes); 2377 } 2378 } 2379 return sym; 2380 } 2381 }); 2382 } 2383 2384 /** Find or create an implicit method of exactly the given type (after erasure). 2385 * Searches in a side table, not the main scope of the site. 2386 * This emulates the lookup process required by JSR 292 in JVM. 2387 * @param env Attribution environment 2388 * @param spMethod signature polymorphic method - i.e. MH.invokeExact 2389 * @param argtypes The required argument types 2390 */ 2391 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env, 2392 final Symbol spMethod, 2393 List<Type> argtypes) { 2394 Type mtype = infer.instantiatePolymorphicSignatureInstance(env, 2395 (MethodSymbol)spMethod, currentResolutionContext, argtypes); 2396 for (Symbol sym : polymorphicSignatureScope.getSymbolsByName(spMethod.name)) { 2397 if (types.isSameType(mtype, sym.type)) { 2398 return sym; 2399 } 2400 } 2401 2402 // create the desired method 2403 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags; 2404 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) { 2405 @Override 2406 public Symbol baseSymbol() { 2407 return spMethod; 2408 } 2409 }; 2410 polymorphicSignatureScope.enter(msym); 2411 return msym; 2412 } 2413 2414 /** Resolve a qualified method identifier, throw a fatal error if not 2415 * found. 2416 * @param pos The position to use for error reporting. 2417 * @param env The environment current at the method invocation. 2418 * @param site The type of the qualifying expression, in which 2419 * identifier is searched. 2420 * @param name The identifier's name. 2421 * @param argtypes The types of the invocation's value arguments. 2422 * @param typeargtypes The types of the invocation's type arguments. 2423 */ 2424 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env, 2425 Type site, Name name, 2426 List<Type> argtypes, 2427 List<Type> typeargtypes) { 2428 MethodResolutionContext resolveContext = new MethodResolutionContext(); 2429 resolveContext.internalResolution = true; 2430 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym, 2431 site, name, argtypes, typeargtypes); 2432 if (sym.kind == MTH) return (MethodSymbol)sym; 2433 else throw new FatalError( 2434 diags.fragment("fatal.err.cant.locate.meth", 2435 name)); 2436 } 2437 2438 /** Resolve constructor. 2439 * @param pos The position to use for error reporting. 2440 * @param env The environment current at the constructor invocation. 2441 * @param site The type of class for which a constructor is searched. 2442 * @param argtypes The types of the constructor invocation's value 2443 * arguments. 2444 * @param typeargtypes The types of the constructor invocation's type 2445 * arguments. 2446 */ 2447 Symbol resolveConstructor(DiagnosticPosition pos, 2448 Env<AttrContext> env, 2449 Type site, 2450 List<Type> argtypes, 2451 List<Type> typeargtypes) { 2452 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes); 2453 } 2454 2455 private Symbol resolveConstructor(MethodResolutionContext resolveContext, 2456 final DiagnosticPosition pos, 2457 Env<AttrContext> env, 2458 Type site, 2459 List<Type> argtypes, 2460 List<Type> typeargtypes) { 2461 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) { 2462 @Override 2463 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2464 return findConstructor(pos, env, site, argtypes, typeargtypes, 2465 phase.isBoxingRequired(), 2466 phase.isVarargsRequired()); 2467 } 2468 }); 2469 } 2470 2471 /** Resolve a constructor, throw a fatal error if not found. 2472 * @param pos The position to use for error reporting. 2473 * @param env The environment current at the method invocation. 2474 * @param site The type to be constructed. 2475 * @param argtypes The types of the invocation's value arguments. 2476 * @param typeargtypes The types of the invocation's type arguments. 2477 */ 2478 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env, 2479 Type site, 2480 List<Type> argtypes, 2481 List<Type> typeargtypes) { 2482 MethodResolutionContext resolveContext = new MethodResolutionContext(); 2483 resolveContext.internalResolution = true; 2484 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes); 2485 if (sym.kind == MTH) return (MethodSymbol)sym; 2486 else throw new FatalError( 2487 diags.fragment("fatal.err.cant.locate.ctor", site)); 2488 } 2489 2490 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env, 2491 Type site, List<Type> argtypes, 2492 List<Type> typeargtypes, 2493 boolean allowBoxing, 2494 boolean useVarargs) { 2495 Symbol sym = findMethod(env, site, 2496 names.init, argtypes, 2497 typeargtypes, allowBoxing, 2498 useVarargs); 2499 chk.checkDeprecated(pos, env.info.scope.owner, sym); 2500 return sym; 2501 } 2502 2503 /** Resolve constructor using diamond inference. 2504 * @param pos The position to use for error reporting. 2505 * @param env The environment current at the constructor invocation. 2506 * @param site The type of class for which a constructor is searched. 2507 * The scope of this class has been touched in attribution. 2508 * @param argtypes The types of the constructor invocation's value 2509 * arguments. 2510 * @param typeargtypes The types of the constructor invocation's type 2511 * arguments. 2512 */ 2513 Symbol resolveDiamond(DiagnosticPosition pos, 2514 Env<AttrContext> env, 2515 Type site, 2516 List<Type> argtypes, 2517 List<Type> typeargtypes) { 2518 return lookupMethod(env, pos, site.tsym, resolveMethodCheck, 2519 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) { 2520 @Override 2521 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2522 return findDiamond(env, site, argtypes, typeargtypes, 2523 phase.isBoxingRequired(), 2524 phase.isVarargsRequired()); 2525 } 2526 @Override 2527 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 2528 if (sym.kind.isOverloadError()) { 2529 if (sym.kind != WRONG_MTH && 2530 sym.kind != WRONG_MTHS) { 2531 sym = super.access(env, pos, location, sym); 2532 } else { 2533 final JCDiagnostic details = sym.kind == WRONG_MTH ? 2534 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd : 2535 null; 2536 sym = new DiamondError(sym, currentResolutionContext); 2537 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes); 2538 env.info.pendingResolutionPhase = currentResolutionContext.step; 2539 } 2540 } 2541 return sym; 2542 }}); 2543 } 2544 2545 /** This method scans all the constructor symbol in a given class scope - 2546 * assuming that the original scope contains a constructor of the kind: 2547 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo, 2548 * a method check is executed against the modified constructor type: 2549 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond 2550 * inference. The inferred return type of the synthetic constructor IS 2551 * the inferred type for the diamond operator. 2552 */ 2553 private Symbol findDiamond(Env<AttrContext> env, 2554 Type site, 2555 List<Type> argtypes, 2556 List<Type> typeargtypes, 2557 boolean allowBoxing, 2558 boolean useVarargs) { 2559 Symbol bestSoFar = methodNotFound; 2560 for (final Symbol sym : site.tsym.members().getSymbolsByName(names.init)) { 2561 //- System.out.println(" e " + e.sym); 2562 if (sym.kind == MTH && 2563 (sym.flags_field & SYNTHETIC) == 0) { 2564 List<Type> oldParams = sym.type.hasTag(FORALL) ? 2565 ((ForAll)sym.type).tvars : 2566 List.<Type>nil(); 2567 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams), 2568 types.createMethodTypeWithReturn(sym.type.asMethodType(), site)); 2569 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) { 2570 @Override 2571 public Symbol baseSymbol() { 2572 return sym; 2573 } 2574 }; 2575 bestSoFar = selectBest(env, site, argtypes, typeargtypes, 2576 newConstr, 2577 bestSoFar, 2578 allowBoxing, 2579 useVarargs); 2580 } 2581 } 2582 return bestSoFar; 2583 } 2584 2585 Symbol getMemberReference(DiagnosticPosition pos, 2586 Env<AttrContext> env, 2587 JCMemberReference referenceTree, 2588 Type site, 2589 Name name) { 2590 2591 site = types.capture(site); 2592 2593 ReferenceLookupHelper lookupHelper = makeReferenceLookupHelper( 2594 referenceTree, site, name, List.<Type>nil(), null, VARARITY); 2595 2596 Env<AttrContext> newEnv = env.dup(env.tree, env.info.dup()); 2597 Symbol sym = lookupMethod(newEnv, env.tree.pos(), site.tsym, 2598 nilMethodCheck, lookupHelper); 2599 2600 env.info.pendingResolutionPhase = newEnv.info.pendingResolutionPhase; 2601 2602 return sym; 2603 } 2604 2605 ReferenceLookupHelper makeReferenceLookupHelper(JCMemberReference referenceTree, 2606 Type site, 2607 Name name, 2608 List<Type> argtypes, 2609 List<Type> typeargtypes, 2610 MethodResolutionPhase maxPhase) { 2611 if (!name.equals(names.init)) { 2612 //method reference 2613 return new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase); 2614 } else if (site.hasTag(ARRAY)) { 2615 //array constructor reference 2616 return new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase); 2617 } else { 2618 //class constructor reference 2619 return new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase); 2620 } 2621 } 2622 2623 /** 2624 * Resolution of member references is typically done as a single 2625 * overload resolution step, where the argument types A are inferred from 2626 * the target functional descriptor. 2627 * 2628 * If the member reference is a method reference with a type qualifier, 2629 * a two-step lookup process is performed. The first step uses the 2630 * expected argument list A, while the second step discards the first 2631 * type from A (which is treated as a receiver type). 2632 * 2633 * There are two cases in which inference is performed: (i) if the member 2634 * reference is a constructor reference and the qualifier type is raw - in 2635 * which case diamond inference is used to infer a parameterization for the 2636 * type qualifier; (ii) if the member reference is an unbound reference 2637 * where the type qualifier is raw - in that case, during the unbound lookup 2638 * the receiver argument type is used to infer an instantiation for the raw 2639 * qualifier type. 2640 * 2641 * When a multi-step resolution process is exploited, the process of picking 2642 * the resulting symbol is delegated to an helper class {@link com.sun.tools.javac.comp.Resolve.ReferenceChooser}. 2643 * 2644 * This routine returns a pair (T,S), where S is the member reference symbol, 2645 * and T is the type of the class in which S is defined. This is necessary as 2646 * the type T might be dynamically inferred (i.e. if constructor reference 2647 * has a raw qualifier). 2648 */ 2649 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(Env<AttrContext> env, 2650 JCMemberReference referenceTree, 2651 Type site, 2652 Name name, 2653 List<Type> argtypes, 2654 List<Type> typeargtypes, 2655 MethodCheck methodCheck, 2656 InferenceContext inferenceContext, 2657 ReferenceChooser referenceChooser) { 2658 2659 site = types.capture(site); 2660 ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper( 2661 referenceTree, site, name, argtypes, typeargtypes, VARARITY); 2662 2663 //step 1 - bound lookup 2664 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup()); 2665 MethodResolutionContext boundSearchResolveContext = new MethodResolutionContext(); 2666 boundSearchResolveContext.methodCheck = methodCheck; 2667 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(), 2668 site.tsym, boundSearchResolveContext, boundLookupHelper); 2669 ReferenceLookupResult boundRes = new ReferenceLookupResult(boundSym, boundSearchResolveContext); 2670 2671 //step 2 - unbound lookup 2672 Symbol unboundSym = methodNotFound; 2673 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup()); 2674 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext); 2675 ReferenceLookupResult unboundRes = referenceNotFound; 2676 if (unboundLookupHelper != null) { 2677 MethodResolutionContext unboundSearchResolveContext = 2678 new MethodResolutionContext(); 2679 unboundSearchResolveContext.methodCheck = methodCheck; 2680 unboundSym = lookupMethod(unboundEnv, env.tree.pos(), 2681 site.tsym, unboundSearchResolveContext, unboundLookupHelper); 2682 unboundRes = new ReferenceLookupResult(unboundSym, unboundSearchResolveContext); 2683 } 2684 2685 //merge results 2686 Pair<Symbol, ReferenceLookupHelper> res; 2687 Symbol bestSym = referenceChooser.result(boundRes, unboundRes); 2688 res = new Pair<>(bestSym, 2689 bestSym == unboundSym ? unboundLookupHelper : boundLookupHelper); 2690 env.info.pendingResolutionPhase = bestSym == unboundSym ? 2691 unboundEnv.info.pendingResolutionPhase : 2692 boundEnv.info.pendingResolutionPhase; 2693 2694 return res; 2695 } 2696 2697 /** 2698 * This class is used to represent a method reference lookup result. It keeps track of two 2699 * things: (i) the symbol found during a method reference lookup and (ii) the static kind 2700 * of the lookup (see {@link com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind}). 2701 */ 2702 static class ReferenceLookupResult { 2703 2704 /** 2705 * Static kind associated with a method reference lookup. Erroneous lookups end up with 2706 * the UNDEFINED kind; successful lookups will end up with either STATIC, NON_STATIC, 2707 * depending on whether all applicable candidates are static or non-static methods, 2708 * respectively. If a successful lookup has both static and non-static applicable methods, 2709 * its kind is set to BOTH. 2710 */ 2711 enum StaticKind { 2712 STATIC, 2713 NON_STATIC, 2714 BOTH, 2715 UNDEFINED; 2716 2717 /** 2718 * Retrieve the static kind associated with a given (method) symbol. 2719 */ 2720 static StaticKind from(Symbol s) { 2721 return s.isStatic() ? 2722 STATIC : NON_STATIC; 2723 } 2724 2725 /** 2726 * Merge two static kinds together. 2727 */ 2728 static StaticKind reduce(StaticKind sk1, StaticKind sk2) { 2729 if (sk1 == UNDEFINED) { 2730 return sk2; 2731 } else if (sk2 == UNDEFINED) { 2732 return sk1; 2733 } else { 2734 return sk1 == sk2 ? sk1 : BOTH; 2735 } 2736 } 2737 } 2738 2739 /** The static kind. */ 2740 StaticKind staticKind; 2741 2742 /** The lookup result. */ 2743 Symbol sym; 2744 2745 ReferenceLookupResult(Symbol sym, MethodResolutionContext resolutionContext) { 2746 this.staticKind = staticKind(sym, resolutionContext); 2747 this.sym = sym; 2748 } 2749 2750 private StaticKind staticKind(Symbol sym, MethodResolutionContext resolutionContext) { 2751 switch (sym.kind) { 2752 case MTH: 2753 case AMBIGUOUS: 2754 return resolutionContext.candidates.stream() 2755 .filter(c -> c.isApplicable() && c.step == resolutionContext.step) 2756 .map(c -> StaticKind.from(c.sym)) 2757 .reduce(StaticKind::reduce) 2758 .orElse(StaticKind.UNDEFINED); 2759 case HIDDEN: 2760 return StaticKind.from(((AccessError)sym).sym); 2761 default: 2762 return StaticKind.UNDEFINED; 2763 } 2764 } 2765 2766 /** 2767 * Does this result corresponds to a successful lookup (i.e. one where a method has been found?) 2768 */ 2769 boolean isSuccess() { 2770 return staticKind != StaticKind.UNDEFINED; 2771 } 2772 2773 /** 2774 * Does this result have given static kind? 2775 */ 2776 boolean hasKind(StaticKind sk) { 2777 return this.staticKind == sk; 2778 } 2779 2780 /** 2781 * Error recovery helper: can this lookup result be ignored (for the purpose of returning 2782 * some 'better' result) ? 2783 */ 2784 boolean canIgnore() { 2785 switch (sym.kind) { 2786 case ABSENT_MTH: 2787 return true; 2788 case WRONG_MTH: 2789 InapplicableSymbolError errSym = 2790 (InapplicableSymbolError)sym.baseSymbol(); 2791 return new Template(MethodCheckDiag.ARITY_MISMATCH.regex()) 2792 .matches(errSym.errCandidate().snd); 2793 case WRONG_MTHS: 2794 InapplicableSymbolsError errSyms = 2795 (InapplicableSymbolsError)sym.baseSymbol(); 2796 return errSyms.filterCandidates(errSyms.mapCandidates()).isEmpty(); 2797 default: 2798 return false; 2799 } 2800 } 2801 } 2802 2803 /** 2804 * This abstract class embodies the logic that converts one (bound lookup) or two (unbound lookup) 2805 * {@code ReferenceLookupResult} objects into a (@code Symbol), which is then regarded as the 2806 * result of method reference resolution. 2807 */ 2808 abstract class ReferenceChooser { 2809 /** 2810 * Generate a result from a pair of lookup result objects. This method delegates to the 2811 * appropriate result generation routine. 2812 */ 2813 Symbol result(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) { 2814 return unboundRes != referenceNotFound ? 2815 unboundResult(boundRes, unboundRes) : 2816 boundResult(boundRes); 2817 } 2818 2819 /** 2820 * Generate a symbol from a given bound lookup result. 2821 */ 2822 abstract Symbol boundResult(ReferenceLookupResult boundRes); 2823 2824 /** 2825 * Generate a symbol from a pair of bound/unbound lookup results. 2826 */ 2827 abstract Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes); 2828 } 2829 2830 /** 2831 * This chooser implements the selection strategy used during a full lookup; this logic 2832 * is described in JLS SE 8 (15.3.2). 2833 */ 2834 ReferenceChooser basicReferenceChooser = new ReferenceChooser() { 2835 2836 @Override 2837 Symbol boundResult(ReferenceLookupResult boundRes) { 2838 return !boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC) ? 2839 boundRes.sym : //the search produces a non-static method 2840 new BadMethodReferenceError(boundRes.sym, false); 2841 } 2842 2843 @Override 2844 Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) { 2845 if (boundRes.hasKind(StaticKind.STATIC) && 2846 (!unboundRes.isSuccess() || unboundRes.hasKind(StaticKind.STATIC))) { 2847 //the first search produces a static method and no non-static method is applicable 2848 //during the second search 2849 return boundRes.sym; 2850 } else if (unboundRes.hasKind(StaticKind.NON_STATIC) && 2851 (!boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC))) { 2852 //the second search produces a non-static method and no static method is applicable 2853 //during the first search 2854 return unboundRes.sym; 2855 } else if (boundRes.isSuccess() && unboundRes.isSuccess()) { 2856 //both searches produce some result; ambiguity (error recovery) 2857 return ambiguityError(boundRes.sym, unboundRes.sym); 2858 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) { 2859 //Both searches failed to produce a result with correct staticness (i.e. first search 2860 //produces an non-static method). Alternatively, a given search produced a result 2861 //with the right staticness, but the other search has applicable methods with wrong 2862 //staticness (error recovery) 2863 return new BadMethodReferenceError(boundRes.isSuccess() ? boundRes.sym : unboundRes.sym, true); 2864 } else { 2865 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery) 2866 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ? 2867 unboundRes.sym : boundRes.sym; 2868 } 2869 } 2870 }; 2871 2872 /** 2873 * This chooser implements the selection strategy used during an arity-based lookup; this logic 2874 * is described in JLS SE 8 (15.12.2.1). 2875 */ 2876 ReferenceChooser structuralReferenceChooser = new ReferenceChooser() { 2877 2878 @Override 2879 Symbol boundResult(ReferenceLookupResult boundRes) { 2880 return (!boundRes.isSuccess() || !boundRes.hasKind(StaticKind.STATIC)) ? 2881 boundRes.sym : //the search has at least one applicable non-static method 2882 new BadMethodReferenceError(boundRes.sym, false); 2883 } 2884 2885 @Override 2886 Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) { 2887 if (boundRes.isSuccess() && !boundRes.hasKind(StaticKind.NON_STATIC)) { 2888 //the first serach has at least one applicable static method 2889 return boundRes.sym; 2890 } else if (unboundRes.isSuccess() && !unboundRes.hasKind(StaticKind.STATIC)) { 2891 //the second search has at least one applicable non-static method 2892 return unboundRes.sym; 2893 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) { 2894 //either the first search produces a non-static method, or second search produces 2895 //a non-static method (error recovery) 2896 return new BadMethodReferenceError(boundRes.isSuccess() ? boundRes.sym : unboundRes.sym, true); 2897 } else { 2898 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery) 2899 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ? 2900 unboundRes.sym : boundRes.sym; 2901 } 2902 } 2903 }; 2904 2905 /** 2906 * Helper for defining custom method-like lookup logic; a lookup helper 2907 * provides hooks for (i) the actual lookup logic and (ii) accessing the 2908 * lookup result (this step might result in compiler diagnostics to be generated) 2909 */ 2910 abstract class LookupHelper { 2911 2912 /** name of the symbol to lookup */ 2913 Name name; 2914 2915 /** location in which the lookup takes place */ 2916 Type site; 2917 2918 /** actual types used during the lookup */ 2919 List<Type> argtypes; 2920 2921 /** type arguments used during the lookup */ 2922 List<Type> typeargtypes; 2923 2924 /** Max overload resolution phase handled by this helper */ 2925 MethodResolutionPhase maxPhase; 2926 2927 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 2928 this.name = name; 2929 this.site = site; 2930 this.argtypes = argtypes; 2931 this.typeargtypes = typeargtypes; 2932 this.maxPhase = maxPhase; 2933 } 2934 2935 /** 2936 * Should lookup stop at given phase with given result 2937 */ 2938 final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) { 2939 return phase.ordinal() > maxPhase.ordinal() || 2940 !sym.kind.isOverloadError() || sym.kind == AMBIGUOUS; 2941 } 2942 2943 /** 2944 * Search for a symbol under a given overload resolution phase - this method 2945 * is usually called several times, once per each overload resolution phase 2946 */ 2947 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase); 2948 2949 /** 2950 * Dump overload resolution info 2951 */ 2952 void debug(DiagnosticPosition pos, Symbol sym) { 2953 //do nothing 2954 } 2955 2956 /** 2957 * Validate the result of the lookup 2958 */ 2959 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym); 2960 } 2961 2962 abstract class BasicLookupHelper extends LookupHelper { 2963 2964 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) { 2965 this(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY); 2966 } 2967 2968 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 2969 super(name, site, argtypes, typeargtypes, maxPhase); 2970 } 2971 2972 @Override 2973 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2974 Symbol sym = doLookup(env, phase); 2975 if (sym.kind == AMBIGUOUS) { 2976 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol(); 2977 sym = a_err.mergeAbstracts(site); 2978 } 2979 return sym; 2980 } 2981 2982 abstract Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase); 2983 2984 @Override 2985 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 2986 if (sym.kind.isOverloadError()) { 2987 //if nothing is found return the 'first' error 2988 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes); 2989 } 2990 return sym; 2991 } 2992 2993 @Override 2994 void debug(DiagnosticPosition pos, Symbol sym) { 2995 reportVerboseResolutionDiagnostic(pos, name, site, argtypes, typeargtypes, sym); 2996 } 2997 } 2998 2999 /** 3000 * Helper class for member reference lookup. A reference lookup helper 3001 * defines the basic logic for member reference lookup; a method gives 3002 * access to an 'unbound' helper used to perform an unbound member 3003 * reference lookup. 3004 */ 3005 abstract class ReferenceLookupHelper extends LookupHelper { 3006 3007 /** The member reference tree */ 3008 JCMemberReference referenceTree; 3009 3010 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site, 3011 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3012 super(name, site, argtypes, typeargtypes, maxPhase); 3013 this.referenceTree = referenceTree; 3014 } 3015 3016 /** 3017 * Returns an unbound version of this lookup helper. By default, this 3018 * method returns an dummy lookup helper. 3019 */ 3020 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3021 return null; 3022 } 3023 3024 /** 3025 * Get the kind of the member reference 3026 */ 3027 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym); 3028 3029 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 3030 if (sym.kind == AMBIGUOUS) { 3031 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol(); 3032 sym = a_err.mergeAbstracts(site); 3033 } 3034 //skip error reporting 3035 return sym; 3036 } 3037 } 3038 3039 /** 3040 * Helper class for method reference lookup. The lookup logic is based 3041 * upon Resolve.findMethod; in certain cases, this helper class has a 3042 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper). 3043 * In such cases, non-static lookup results are thrown away. 3044 */ 3045 class MethodReferenceLookupHelper extends ReferenceLookupHelper { 3046 3047 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site, 3048 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3049 super(referenceTree, name, site, argtypes, typeargtypes, maxPhase); 3050 } 3051 3052 @Override 3053 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3054 return findMethod(env, site, name, argtypes, typeargtypes, 3055 phase.isBoxingRequired(), phase.isVarargsRequired()); 3056 } 3057 3058 @Override 3059 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3060 if (TreeInfo.isStaticSelector(referenceTree.expr, names)) { 3061 if (argtypes.nonEmpty() && 3062 (argtypes.head.hasTag(NONE) || 3063 types.isSubtypeUnchecked(inferenceContext.asUndetVar(argtypes.head), site))) { 3064 return new UnboundMethodReferenceLookupHelper(referenceTree, name, 3065 site, argtypes, typeargtypes, maxPhase); 3066 } else { 3067 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) { 3068 @Override 3069 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3070 return this; 3071 } 3072 3073 @Override 3074 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3075 return methodNotFound; 3076 } 3077 3078 @Override 3079 ReferenceKind referenceKind(Symbol sym) { 3080 Assert.error(); 3081 return null; 3082 } 3083 }; 3084 } 3085 } else { 3086 return super.unboundLookup(inferenceContext); 3087 } 3088 } 3089 3090 @Override 3091 ReferenceKind referenceKind(Symbol sym) { 3092 if (sym.isStatic()) { 3093 return ReferenceKind.STATIC; 3094 } else { 3095 Name selName = TreeInfo.name(referenceTree.getQualifierExpression()); 3096 return selName != null && selName == names._super ? 3097 ReferenceKind.SUPER : 3098 ReferenceKind.BOUND; 3099 } 3100 } 3101 } 3102 3103 /** 3104 * Helper class for unbound method reference lookup. Essentially the same 3105 * as the basic method reference lookup helper; main difference is that static 3106 * lookup results are thrown away. If qualifier type is raw, an attempt to 3107 * infer a parameterized type is made using the first actual argument (that 3108 * would otherwise be ignored during the lookup). 3109 */ 3110 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper { 3111 3112 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site, 3113 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3114 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase); 3115 if (site.isRaw() && !argtypes.head.hasTag(NONE)) { 3116 Type asSuperSite = types.asSuper(argtypes.head, site.tsym); 3117 this.site = types.capture(asSuperSite); 3118 } 3119 } 3120 3121 @Override 3122 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3123 return this; 3124 } 3125 3126 @Override 3127 ReferenceKind referenceKind(Symbol sym) { 3128 return ReferenceKind.UNBOUND; 3129 } 3130 } 3131 3132 /** 3133 * Helper class for array constructor lookup; an array constructor lookup 3134 * is simulated by looking up a method that returns the array type specified 3135 * as qualifier, and that accepts a single int parameter (size of the array). 3136 */ 3137 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper { 3138 3139 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes, 3140 List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3141 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase); 3142 } 3143 3144 @Override 3145 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3146 WriteableScope sc = WriteableScope.create(syms.arrayClass); 3147 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym); 3148 arrayConstr.type = new MethodType(List.<Type>of(syms.intType), site, List.<Type>nil(), syms.methodClass); 3149 sc.enter(arrayConstr); 3150 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false); 3151 } 3152 3153 @Override 3154 ReferenceKind referenceKind(Symbol sym) { 3155 return ReferenceKind.ARRAY_CTOR; 3156 } 3157 } 3158 3159 /** 3160 * Helper class for constructor reference lookup. The lookup logic is based 3161 * upon either Resolve.findMethod or Resolve.findDiamond - depending on 3162 * whether the constructor reference needs diamond inference (this is the case 3163 * if the qualifier type is raw). A special erroneous symbol is returned 3164 * if the lookup returns the constructor of an inner class and there's no 3165 * enclosing instance in scope. 3166 */ 3167 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper { 3168 3169 boolean needsInference; 3170 3171 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes, 3172 List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3173 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase); 3174 if (site.isRaw()) { 3175 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym, site.getMetadata()); 3176 needsInference = true; 3177 } 3178 } 3179 3180 @Override 3181 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3182 Symbol sym = needsInference ? 3183 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) : 3184 findMethod(env, site, name, argtypes, typeargtypes, 3185 phase.isBoxingRequired(), phase.isVarargsRequired()); 3186 return (sym.kind != MTH || 3187 site.getEnclosingType().hasTag(NONE) || 3188 hasEnclosingInstance(env, site)) ? 3189 sym : new BadConstructorReferenceError(sym); 3190 } 3191 3192 @Override 3193 ReferenceKind referenceKind(Symbol sym) { 3194 return site.getEnclosingType().hasTag(NONE) ? 3195 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER; 3196 } 3197 } 3198 3199 /** 3200 * Main overload resolution routine. On each overload resolution step, a 3201 * lookup helper class is used to perform the method/constructor lookup; 3202 * at the end of the lookup, the helper is used to validate the results 3203 * (this last step might trigger overload resolution diagnostics). 3204 */ 3205 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) { 3206 MethodResolutionContext resolveContext = new MethodResolutionContext(); 3207 resolveContext.methodCheck = methodCheck; 3208 return lookupMethod(env, pos, location, resolveContext, lookupHelper); 3209 } 3210 3211 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, 3212 MethodResolutionContext resolveContext, LookupHelper lookupHelper) { 3213 MethodResolutionContext prevResolutionContext = currentResolutionContext; 3214 try { 3215 Symbol bestSoFar = methodNotFound; 3216 currentResolutionContext = resolveContext; 3217 for (MethodResolutionPhase phase : methodResolutionSteps) { 3218 if (lookupHelper.shouldStop(bestSoFar, phase)) 3219 break; 3220 MethodResolutionPhase prevPhase = currentResolutionContext.step; 3221 Symbol prevBest = bestSoFar; 3222 currentResolutionContext.step = phase; 3223 Symbol sym = lookupHelper.lookup(env, phase); 3224 lookupHelper.debug(pos, sym); 3225 bestSoFar = phase.mergeResults(bestSoFar, sym); 3226 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase; 3227 } 3228 return lookupHelper.access(env, pos, location, bestSoFar); 3229 } finally { 3230 currentResolutionContext = prevResolutionContext; 3231 } 3232 } 3233 3234 /** 3235 * Resolve `c.name' where name == this or name == super. 3236 * @param pos The position to use for error reporting. 3237 * @param env The environment current at the expression. 3238 * @param c The qualifier. 3239 * @param name The identifier's name. 3240 */ 3241 Symbol resolveSelf(DiagnosticPosition pos, 3242 Env<AttrContext> env, 3243 TypeSymbol c, 3244 Name name) { 3245 Env<AttrContext> env1 = env; 3246 boolean staticOnly = false; 3247 while (env1.outer != null) { 3248 if (isStatic(env1)) staticOnly = true; 3249 if (env1.enclClass.sym == c) { 3250 Symbol sym = env1.info.scope.findFirst(name); 3251 if (sym != null) { 3252 if (staticOnly) sym = new StaticError(sym); 3253 return accessBase(sym, pos, env.enclClass.sym.type, 3254 name, true); 3255 } 3256 } 3257 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true; 3258 env1 = env1.outer; 3259 } 3260 if (c.isInterface() && 3261 name == names._super && !isStatic(env) && 3262 types.isDirectSuperInterface(c, env.enclClass.sym)) { 3263 //this might be a default super call if one of the superinterfaces is 'c' 3264 for (Type t : pruneInterfaces(env.enclClass.type)) { 3265 if (t.tsym == c) { 3266 env.info.defaultSuperCallSite = t; 3267 return new VarSymbol(0, names._super, 3268 types.asSuper(env.enclClass.type, c), env.enclClass.sym); 3269 } 3270 } 3271 //find a direct superinterface that is a subtype of 'c' 3272 for (Type i : types.interfaces(env.enclClass.type)) { 3273 if (i.tsym.isSubClass(c, types) && i.tsym != c) { 3274 log.error(pos, "illegal.default.super.call", c, 3275 diags.fragment("redundant.supertype", c, i)); 3276 return syms.errSymbol; 3277 } 3278 } 3279 Assert.error(); 3280 } 3281 log.error(pos, "not.encl.class", c); 3282 return syms.errSymbol; 3283 } 3284 //where 3285 private List<Type> pruneInterfaces(Type t) { 3286 ListBuffer<Type> result = new ListBuffer<>(); 3287 for (Type t1 : types.interfaces(t)) { 3288 boolean shouldAdd = true; 3289 for (Type t2 : types.interfaces(t)) { 3290 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) { 3291 shouldAdd = false; 3292 } 3293 } 3294 if (shouldAdd) { 3295 result.append(t1); 3296 } 3297 } 3298 return result.toList(); 3299 } 3300 3301 3302 /** 3303 * Resolve `c.this' for an enclosing class c that contains the 3304 * named member. 3305 * @param pos The position to use for error reporting. 3306 * @param env The environment current at the expression. 3307 * @param member The member that must be contained in the result. 3308 */ 3309 Symbol resolveSelfContaining(DiagnosticPosition pos, 3310 Env<AttrContext> env, 3311 Symbol member, 3312 boolean isSuperCall) { 3313 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall); 3314 if (sym == null) { 3315 log.error(pos, "encl.class.required", member); 3316 return syms.errSymbol; 3317 } else { 3318 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true); 3319 } 3320 } 3321 3322 boolean hasEnclosingInstance(Env<AttrContext> env, Type type) { 3323 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false); 3324 return encl != null && !encl.kind.isOverloadError(); 3325 } 3326 3327 private Symbol resolveSelfContainingInternal(Env<AttrContext> env, 3328 Symbol member, 3329 boolean isSuperCall) { 3330 Name name = names._this; 3331 Env<AttrContext> env1 = isSuperCall ? env.outer : env; 3332 boolean staticOnly = false; 3333 if (env1 != null) { 3334 while (env1 != null && env1.outer != null) { 3335 if (isStatic(env1)) staticOnly = true; 3336 if (env1.enclClass.sym.isSubClass(member.owner, types)) { 3337 Symbol sym = env1.info.scope.findFirst(name); 3338 if (sym != null) { 3339 if (staticOnly) sym = new StaticError(sym); 3340 return sym; 3341 } 3342 } 3343 if ((env1.enclClass.sym.flags() & STATIC) != 0) 3344 staticOnly = true; 3345 env1 = env1.outer; 3346 } 3347 } 3348 return null; 3349 } 3350 3351 /** 3352 * Resolve an appropriate implicit this instance for t's container. 3353 * JLS 8.8.5.1 and 15.9.2 3354 */ 3355 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) { 3356 return resolveImplicitThis(pos, env, t, false); 3357 } 3358 3359 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) { 3360 Type thisType = (t.tsym.owner.kind.matches(KindSelector.VAL_MTH) 3361 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this) 3362 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type; 3363 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym) 3364 log.error(pos, "cant.ref.before.ctor.called", "this"); 3365 return thisType; 3366 } 3367 3368/* *************************************************************************** 3369 * ResolveError classes, indicating error situations when accessing symbols 3370 ****************************************************************************/ 3371 3372 //used by TransTypes when checking target type of synthetic cast 3373 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) { 3374 AccessError error = new AccessError(env, env.enclClass.type, type.tsym); 3375 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null); 3376 } 3377 //where 3378 private void logResolveError(ResolveError error, 3379 DiagnosticPosition pos, 3380 Symbol location, 3381 Type site, 3382 Name name, 3383 List<Type> argtypes, 3384 List<Type> typeargtypes) { 3385 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR, 3386 pos, location, site, name, argtypes, typeargtypes); 3387 if (d != null) { 3388 d.setFlag(DiagnosticFlag.RESOLVE_ERROR); 3389 log.report(d); 3390 } 3391 } 3392 3393 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args"); 3394 3395 public Object methodArguments(List<Type> argtypes) { 3396 if (argtypes == null || argtypes.isEmpty()) { 3397 return noArgs; 3398 } else { 3399 ListBuffer<Object> diagArgs = new ListBuffer<>(); 3400 for (Type t : argtypes) { 3401 if (t.hasTag(DEFERRED)) { 3402 diagArgs.append(((DeferredAttr.DeferredType)t).tree); 3403 } else { 3404 diagArgs.append(t); 3405 } 3406 } 3407 return diagArgs; 3408 } 3409 } 3410 3411 /** 3412 * Root class for resolution errors. Subclass of ResolveError 3413 * represent a different kinds of resolution error - as such they must 3414 * specify how they map into concrete compiler diagnostics. 3415 */ 3416 abstract class ResolveError extends Symbol { 3417 3418 /** The name of the kind of error, for debugging only. */ 3419 final String debugName; 3420 3421 ResolveError(Kind kind, String debugName) { 3422 super(kind, 0, null, null, null); 3423 this.debugName = debugName; 3424 } 3425 3426 @Override @DefinedBy(Api.LANGUAGE_MODEL) 3427 public <R, P> R accept(ElementVisitor<R, P> v, P p) { 3428 throw new AssertionError(); 3429 } 3430 3431 @Override 3432 public String toString() { 3433 return debugName; 3434 } 3435 3436 @Override 3437 public boolean exists() { 3438 return false; 3439 } 3440 3441 @Override 3442 public boolean isStatic() { 3443 return false; 3444 } 3445 3446 /** 3447 * Create an external representation for this erroneous symbol to be 3448 * used during attribution - by default this returns the symbol of a 3449 * brand new error type which stores the original type found 3450 * during resolution. 3451 * 3452 * @param name the name used during resolution 3453 * @param location the location from which the symbol is accessed 3454 */ 3455 protected Symbol access(Name name, TypeSymbol location) { 3456 return types.createErrorType(name, location, syms.errSymbol.type).tsym; 3457 } 3458 3459 /** 3460 * Create a diagnostic representing this resolution error. 3461 * 3462 * @param dkind The kind of the diagnostic to be created (e.g error). 3463 * @param pos The position to be used for error reporting. 3464 * @param site The original type from where the selection took place. 3465 * @param name The name of the symbol to be resolved. 3466 * @param argtypes The invocation's value arguments, 3467 * if we looked for a method. 3468 * @param typeargtypes The invocation's type arguments, 3469 * if we looked for a method. 3470 */ 3471 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3472 DiagnosticPosition pos, 3473 Symbol location, 3474 Type site, 3475 Name name, 3476 List<Type> argtypes, 3477 List<Type> typeargtypes); 3478 } 3479 3480 /** 3481 * This class is the root class of all resolution errors caused by 3482 * an invalid symbol being found during resolution. 3483 */ 3484 abstract class InvalidSymbolError extends ResolveError { 3485 3486 /** The invalid symbol found during resolution */ 3487 Symbol sym; 3488 3489 InvalidSymbolError(Kind kind, Symbol sym, String debugName) { 3490 super(kind, debugName); 3491 this.sym = sym; 3492 } 3493 3494 @Override 3495 public boolean exists() { 3496 return true; 3497 } 3498 3499 @Override 3500 public String toString() { 3501 return super.toString() + " wrongSym=" + sym; 3502 } 3503 3504 @Override 3505 public Symbol access(Name name, TypeSymbol location) { 3506 if (!sym.kind.isOverloadError() && sym.kind.matches(KindSelector.TYP)) 3507 return types.createErrorType(name, location, sym.type).tsym; 3508 else 3509 return sym; 3510 } 3511 } 3512 3513 /** 3514 * InvalidSymbolError error class indicating that a symbol matching a 3515 * given name does not exists in a given site. 3516 */ 3517 class SymbolNotFoundError extends ResolveError { 3518 3519 SymbolNotFoundError(Kind kind) { 3520 this(kind, "symbol not found error"); 3521 } 3522 3523 SymbolNotFoundError(Kind kind, String debugName) { 3524 super(kind, debugName); 3525 } 3526 3527 @Override 3528 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3529 DiagnosticPosition pos, 3530 Symbol location, 3531 Type site, 3532 Name name, 3533 List<Type> argtypes, 3534 List<Type> typeargtypes) { 3535 argtypes = argtypes == null ? List.<Type>nil() : argtypes; 3536 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes; 3537 if (name == names.error) 3538 return null; 3539 3540 boolean hasLocation = false; 3541 if (location == null) { 3542 location = site.tsym; 3543 } 3544 if (!location.name.isEmpty()) { 3545 if (location.kind == PCK && !site.tsym.exists()) { 3546 return diags.create(dkind, log.currentSource(), pos, 3547 "doesnt.exist", location); 3548 } 3549 hasLocation = !location.name.equals(names._this) && 3550 !location.name.equals(names._super); 3551 } 3552 boolean isConstructor = name == names.init; 3553 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : kind.absentKind(); 3554 Name idname = isConstructor ? site.tsym.name : name; 3555 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation); 3556 if (hasLocation) { 3557 return diags.create(dkind, log.currentSource(), pos, 3558 errKey, kindname, idname, //symbol kindname, name 3559 typeargtypes, args(argtypes), //type parameters and arguments (if any) 3560 getLocationDiag(location, site)); //location kindname, type 3561 } 3562 else { 3563 return diags.create(dkind, log.currentSource(), pos, 3564 errKey, kindname, idname, //symbol kindname, name 3565 typeargtypes, args(argtypes)); //type parameters and arguments (if any) 3566 } 3567 } 3568 //where 3569 private Object args(List<Type> args) { 3570 return args.isEmpty() ? args : methodArguments(args); 3571 } 3572 3573 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) { 3574 String key = "cant.resolve"; 3575 String suffix = hasLocation ? ".location" : ""; 3576 switch (kindname) { 3577 case METHOD: 3578 case CONSTRUCTOR: { 3579 suffix += ".args"; 3580 suffix += hasTypeArgs ? ".params" : ""; 3581 } 3582 } 3583 return key + suffix; 3584 } 3585 private JCDiagnostic getLocationDiag(Symbol location, Type site) { 3586 if (location.kind == VAR) { 3587 return diags.fragment("location.1", 3588 kindName(location), 3589 location, 3590 location.type); 3591 } else { 3592 return diags.fragment("location", 3593 typeKindName(site), 3594 site, 3595 null); 3596 } 3597 } 3598 } 3599 3600 /** 3601 * InvalidSymbolError error class indicating that a given symbol 3602 * (either a method, a constructor or an operand) is not applicable 3603 * given an actual arguments/type argument list. 3604 */ 3605 class InapplicableSymbolError extends ResolveError { 3606 3607 protected MethodResolutionContext resolveContext; 3608 3609 InapplicableSymbolError(MethodResolutionContext context) { 3610 this(WRONG_MTH, "inapplicable symbol error", context); 3611 } 3612 3613 protected InapplicableSymbolError(Kind kind, String debugName, MethodResolutionContext context) { 3614 super(kind, debugName); 3615 this.resolveContext = context; 3616 } 3617 3618 @Override 3619 public String toString() { 3620 return super.toString(); 3621 } 3622 3623 @Override 3624 public boolean exists() { 3625 return true; 3626 } 3627 3628 @Override 3629 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3630 DiagnosticPosition pos, 3631 Symbol location, 3632 Type site, 3633 Name name, 3634 List<Type> argtypes, 3635 List<Type> typeargtypes) { 3636 if (name == names.error) 3637 return null; 3638 3639 Pair<Symbol, JCDiagnostic> c = errCandidate(); 3640 if (compactMethodDiags) { 3641 JCDiagnostic simpleDiag = 3642 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, c.snd); 3643 if (simpleDiag != null) { 3644 return simpleDiag; 3645 } 3646 } 3647 Symbol ws = c.fst.asMemberOf(site, types); 3648 return diags.create(dkind, log.currentSource(), pos, 3649 "cant.apply.symbol", 3650 kindName(ws), 3651 ws.name == names.init ? ws.owner.name : ws.name, 3652 methodArguments(ws.type.getParameterTypes()), 3653 methodArguments(argtypes), 3654 kindName(ws.owner), 3655 ws.owner.type, 3656 c.snd); 3657 } 3658 3659 @Override 3660 public Symbol access(Name name, TypeSymbol location) { 3661 return types.createErrorType(name, location, syms.errSymbol.type).tsym; 3662 } 3663 3664 protected Pair<Symbol, JCDiagnostic> errCandidate() { 3665 Candidate bestSoFar = null; 3666 for (Candidate c : resolveContext.candidates) { 3667 if (c.isApplicable()) continue; 3668 bestSoFar = c; 3669 } 3670 Assert.checkNonNull(bestSoFar); 3671 return new Pair<>(bestSoFar.sym, bestSoFar.details); 3672 } 3673 } 3674 3675 /** 3676 * ResolveError error class indicating that a symbol (either methods, constructors or operand) 3677 * is not applicable given an actual arguments/type argument list. 3678 */ 3679 class InapplicableSymbolsError extends InapplicableSymbolError { 3680 3681 InapplicableSymbolsError(MethodResolutionContext context) { 3682 super(WRONG_MTHS, "inapplicable symbols", context); 3683 } 3684 3685 @Override 3686 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3687 DiagnosticPosition pos, 3688 Symbol location, 3689 Type site, 3690 Name name, 3691 List<Type> argtypes, 3692 List<Type> typeargtypes) { 3693 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates(); 3694 Map<Symbol, JCDiagnostic> filteredCandidates = compactMethodDiags ? 3695 filterCandidates(candidatesMap) : 3696 mapCandidates(); 3697 if (filteredCandidates.isEmpty()) { 3698 filteredCandidates = candidatesMap; 3699 } 3700 boolean truncatedDiag = candidatesMap.size() != filteredCandidates.size(); 3701 if (filteredCandidates.size() > 1) { 3702 JCDiagnostic err = diags.create(dkind, 3703 null, 3704 truncatedDiag ? 3705 EnumSet.of(DiagnosticFlag.COMPRESSED) : 3706 EnumSet.noneOf(DiagnosticFlag.class), 3707 log.currentSource(), 3708 pos, 3709 "cant.apply.symbols", 3710 name == names.init ? KindName.CONSTRUCTOR : kind.absentKind(), 3711 name == names.init ? site.tsym.name : name, 3712 methodArguments(argtypes)); 3713 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(filteredCandidates, site)); 3714 } else if (filteredCandidates.size() == 1) { 3715 Map.Entry<Symbol, JCDiagnostic> _e = 3716 filteredCandidates.entrySet().iterator().next(); 3717 final Pair<Symbol, JCDiagnostic> p = new Pair<>(_e.getKey(), _e.getValue()); 3718 JCDiagnostic d = new InapplicableSymbolError(resolveContext) { 3719 @Override 3720 protected Pair<Symbol, JCDiagnostic> errCandidate() { 3721 return p; 3722 } 3723 }.getDiagnostic(dkind, pos, 3724 location, site, name, argtypes, typeargtypes); 3725 if (truncatedDiag) { 3726 d.setFlag(DiagnosticFlag.COMPRESSED); 3727 } 3728 return d; 3729 } else { 3730 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos, 3731 location, site, name, argtypes, typeargtypes); 3732 } 3733 } 3734 //where 3735 private Map<Symbol, JCDiagnostic> mapCandidates() { 3736 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<>(); 3737 for (Candidate c : resolveContext.candidates) { 3738 if (c.isApplicable()) continue; 3739 candidates.put(c.sym, c.details); 3740 } 3741 return candidates; 3742 } 3743 3744 Map<Symbol, JCDiagnostic> filterCandidates(Map<Symbol, JCDiagnostic> candidatesMap) { 3745 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<>(); 3746 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) { 3747 JCDiagnostic d = _entry.getValue(); 3748 if (!new Template(MethodCheckDiag.ARITY_MISMATCH.regex()).matches(d)) { 3749 candidates.put(_entry.getKey(), d); 3750 } 3751 } 3752 return candidates; 3753 } 3754 3755 private List<JCDiagnostic> candidateDetails(Map<Symbol, JCDiagnostic> candidatesMap, Type site) { 3756 List<JCDiagnostic> details = List.nil(); 3757 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) { 3758 Symbol sym = _entry.getKey(); 3759 JCDiagnostic detailDiag = diags.fragment("inapplicable.method", 3760 Kinds.kindName(sym), 3761 sym.location(site, types), 3762 sym.asMemberOf(site, types), 3763 _entry.getValue()); 3764 details = details.prepend(detailDiag); 3765 } 3766 //typically members are visited in reverse order (see Scope) 3767 //so we need to reverse the candidate list so that candidates 3768 //conform to source order 3769 return details; 3770 } 3771 } 3772 3773 /** 3774 * DiamondError error class indicating that a constructor symbol is not applicable 3775 * given an actual arguments/type argument list using diamond inference. 3776 */ 3777 class DiamondError extends InapplicableSymbolError { 3778 3779 Symbol sym; 3780 3781 public DiamondError(Symbol sym, MethodResolutionContext context) { 3782 super(sym.kind, "diamondError", context); 3783 this.sym = sym; 3784 } 3785 3786 JCDiagnostic getDetails() { 3787 return (sym.kind == WRONG_MTH) ? 3788 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd : 3789 null; 3790 } 3791 3792 @Override 3793 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, 3794 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) { 3795 JCDiagnostic details = getDetails(); 3796 if (details != null && compactMethodDiags) { 3797 JCDiagnostic simpleDiag = 3798 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, details); 3799 if (simpleDiag != null) { 3800 return simpleDiag; 3801 } 3802 } 3803 String key = details == null ? 3804 "cant.apply.diamond" : 3805 "cant.apply.diamond.1"; 3806 return diags.create(dkind, log.currentSource(), pos, key, 3807 diags.fragment("diamond", site.tsym), details); 3808 } 3809 } 3810 3811 /** 3812 * An InvalidSymbolError error class indicating that a symbol is not 3813 * accessible from a given site 3814 */ 3815 class AccessError extends InvalidSymbolError { 3816 3817 private Env<AttrContext> env; 3818 private Type site; 3819 3820 AccessError(Symbol sym) { 3821 this(null, null, sym); 3822 } 3823 3824 AccessError(Env<AttrContext> env, Type site, Symbol sym) { 3825 super(HIDDEN, sym, "access error"); 3826 this.env = env; 3827 this.site = site; 3828 if (debugResolve) 3829 log.error("proc.messager", sym + " @ " + site + " is inaccessible."); 3830 } 3831 3832 @Override 3833 public boolean exists() { 3834 return false; 3835 } 3836 3837 @Override 3838 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3839 DiagnosticPosition pos, 3840 Symbol location, 3841 Type site, 3842 Name name, 3843 List<Type> argtypes, 3844 List<Type> typeargtypes) { 3845 if (sym.owner.type.hasTag(ERROR)) 3846 return null; 3847 3848 if (sym.name == names.init && sym.owner != site.tsym) { 3849 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, 3850 pos, location, site, name, argtypes, typeargtypes); 3851 } 3852 else if ((sym.flags() & PUBLIC) != 0 3853 || (env != null && this.site != null 3854 && !isAccessible(env, this.site))) { 3855 return diags.create(dkind, log.currentSource(), 3856 pos, "not.def.access.class.intf.cant.access", 3857 sym, sym.location()); 3858 } 3859 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) { 3860 return diags.create(dkind, log.currentSource(), 3861 pos, "report.access", sym, 3862 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)), 3863 sym.location()); 3864 } 3865 else { 3866 return diags.create(dkind, log.currentSource(), 3867 pos, "not.def.public.cant.access", sym, sym.location()); 3868 } 3869 } 3870 } 3871 3872 /** 3873 * InvalidSymbolError error class indicating that an instance member 3874 * has erroneously been accessed from a static context. 3875 */ 3876 class StaticError extends InvalidSymbolError { 3877 3878 StaticError(Symbol sym) { 3879 super(STATICERR, sym, "static error"); 3880 } 3881 3882 @Override 3883 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3884 DiagnosticPosition pos, 3885 Symbol location, 3886 Type site, 3887 Name name, 3888 List<Type> argtypes, 3889 List<Type> typeargtypes) { 3890 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS)) 3891 ? types.erasure(sym.type).tsym 3892 : sym); 3893 return diags.create(dkind, log.currentSource(), pos, 3894 "non-static.cant.be.ref", kindName(sym), errSym); 3895 } 3896 } 3897 3898 /** 3899 * InvalidSymbolError error class indicating that a pair of symbols 3900 * (either methods, constructors or operands) are ambiguous 3901 * given an actual arguments/type argument list. 3902 */ 3903 class AmbiguityError extends ResolveError { 3904 3905 /** The other maximally specific symbol */ 3906 List<Symbol> ambiguousSyms = List.nil(); 3907 3908 @Override 3909 public boolean exists() { 3910 return true; 3911 } 3912 3913 AmbiguityError(Symbol sym1, Symbol sym2) { 3914 super(AMBIGUOUS, "ambiguity error"); 3915 ambiguousSyms = flatten(sym2).appendList(flatten(sym1)); 3916 } 3917 3918 private List<Symbol> flatten(Symbol sym) { 3919 if (sym.kind == AMBIGUOUS) { 3920 return ((AmbiguityError)sym.baseSymbol()).ambiguousSyms; 3921 } else { 3922 return List.of(sym); 3923 } 3924 } 3925 3926 AmbiguityError addAmbiguousSymbol(Symbol s) { 3927 ambiguousSyms = ambiguousSyms.prepend(s); 3928 return this; 3929 } 3930 3931 @Override 3932 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3933 DiagnosticPosition pos, 3934 Symbol location, 3935 Type site, 3936 Name name, 3937 List<Type> argtypes, 3938 List<Type> typeargtypes) { 3939 List<Symbol> diagSyms = ambiguousSyms.reverse(); 3940 Symbol s1 = diagSyms.head; 3941 Symbol s2 = diagSyms.tail.head; 3942 Name sname = s1.name; 3943 if (sname == names.init) sname = s1.owner.name; 3944 return diags.create(dkind, log.currentSource(), 3945 pos, "ref.ambiguous", sname, 3946 kindName(s1), 3947 s1, 3948 s1.location(site, types), 3949 kindName(s2), 3950 s2, 3951 s2.location(site, types)); 3952 } 3953 3954 /** 3955 * If multiple applicable methods are found during overload and none of them 3956 * is more specific than the others, attempt to merge their signatures. 3957 */ 3958 Symbol mergeAbstracts(Type site) { 3959 List<Symbol> ambiguousInOrder = ambiguousSyms.reverse(); 3960 for (Symbol s : ambiguousInOrder) { 3961 Type mt = types.memberType(site, s); 3962 boolean found = true; 3963 List<Type> allThrown = mt.getThrownTypes(); 3964 for (Symbol s2 : ambiguousInOrder) { 3965 Type mt2 = types.memberType(site, s2); 3966 if ((s2.flags() & ABSTRACT) == 0 || 3967 !types.overrideEquivalent(mt, mt2) || 3968 !types.isSameTypes(s.erasure(types).getParameterTypes(), 3969 s2.erasure(types).getParameterTypes())) { 3970 //ambiguity cannot be resolved 3971 return this; 3972 } 3973 Type mst = mostSpecificReturnType(mt, mt2); 3974 if (mst == null || mst != mt) { 3975 found = false; 3976 break; 3977 } 3978 allThrown = chk.intersect(allThrown, mt2.getThrownTypes()); 3979 } 3980 if (found) { 3981 //all ambiguous methods were abstract and one method had 3982 //most specific return type then others 3983 return (allThrown == mt.getThrownTypes()) ? 3984 s : new MethodSymbol( 3985 s.flags(), 3986 s.name, 3987 types.createMethodTypeWithThrown(s.type, allThrown), 3988 s.owner); 3989 } 3990 } 3991 return this; 3992 } 3993 3994 @Override 3995 protected Symbol access(Name name, TypeSymbol location) { 3996 Symbol firstAmbiguity = ambiguousSyms.last(); 3997 return firstAmbiguity.kind == TYP ? 3998 types.createErrorType(name, location, firstAmbiguity.type).tsym : 3999 firstAmbiguity; 4000 } 4001 } 4002 4003 class BadVarargsMethod extends ResolveError { 4004 4005 ResolveError delegatedError; 4006 4007 BadVarargsMethod(ResolveError delegatedError) { 4008 super(delegatedError.kind, "badVarargs"); 4009 this.delegatedError = delegatedError; 4010 } 4011 4012 @Override 4013 public Symbol baseSymbol() { 4014 return delegatedError.baseSymbol(); 4015 } 4016 4017 @Override 4018 protected Symbol access(Name name, TypeSymbol location) { 4019 return delegatedError.access(name, location); 4020 } 4021 4022 @Override 4023 public boolean exists() { 4024 return true; 4025 } 4026 4027 @Override 4028 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) { 4029 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes); 4030 } 4031 } 4032 4033 /** 4034 * BadMethodReferenceError error class indicating that a method reference symbol has been found, 4035 * but with the wrong staticness. 4036 */ 4037 class BadMethodReferenceError extends StaticError { 4038 4039 boolean unboundLookup; 4040 4041 public BadMethodReferenceError(Symbol sym, boolean unboundLookup) { 4042 super(sym); 4043 this.unboundLookup = unboundLookup; 4044 } 4045 4046 @Override 4047 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) { 4048 final String key; 4049 if (!unboundLookup) { 4050 key = "bad.static.method.in.bound.lookup"; 4051 } else if (sym.isStatic()) { 4052 key = "bad.static.method.in.unbound.lookup"; 4053 } else { 4054 key = "bad.instance.method.in.unbound.lookup"; 4055 } 4056 return sym.kind.isOverloadError() ? 4057 ((ResolveError)sym).getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes) : 4058 diags.create(dkind, log.currentSource(), pos, key, Kinds.kindName(sym), sym); 4059 } 4060 } 4061 4062 /** 4063 * BadConstructorReferenceError error class indicating that a constructor reference symbol has been found, 4064 * but pointing to a class for which an enclosing instance is not available. 4065 */ 4066 class BadConstructorReferenceError extends InvalidSymbolError { 4067 4068 public BadConstructorReferenceError(Symbol sym) { 4069 super(MISSING_ENCL, sym, "BadConstructorReferenceError"); 4070 } 4071 4072 @Override 4073 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) { 4074 return diags.create(dkind, log.currentSource(), pos, 4075 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType()); 4076 } 4077 } 4078 4079 /** 4080 * Helper class for method resolution diagnostic simplification. 4081 * Certain resolution diagnostic are rewritten as simpler diagnostic 4082 * where the enclosing resolution diagnostic (i.e. 'inapplicable method') 4083 * is stripped away, as it doesn't carry additional info. The logic 4084 * for matching a given diagnostic is given in terms of a template 4085 * hierarchy: a diagnostic template can be specified programmatically, 4086 * so that only certain diagnostics are matched. Each templete is then 4087 * associated with a rewriter object that carries out the task of rewtiting 4088 * the diagnostic to a simpler one. 4089 */ 4090 static class MethodResolutionDiagHelper { 4091 4092 /** 4093 * A diagnostic rewriter transforms a method resolution diagnostic 4094 * into a simpler one 4095 */ 4096 interface DiagnosticRewriter { 4097 JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags, 4098 DiagnosticPosition preferedPos, DiagnosticSource preferredSource, 4099 DiagnosticType preferredKind, JCDiagnostic d); 4100 } 4101 4102 /** 4103 * A diagnostic template is made up of two ingredients: (i) a regular 4104 * expression for matching a diagnostic key and (ii) a list of sub-templates 4105 * for matching diagnostic arguments. 4106 */ 4107 static class Template { 4108 4109 /** regex used to match diag key */ 4110 String regex; 4111 4112 /** templates used to match diagnostic args */ 4113 Template[] subTemplates; 4114 4115 Template(String key, Template... subTemplates) { 4116 this.regex = key; 4117 this.subTemplates = subTemplates; 4118 } 4119 4120 /** 4121 * Returns true if the regex matches the diagnostic key and if 4122 * all diagnostic arguments are matches by corresponding sub-templates. 4123 */ 4124 boolean matches(Object o) { 4125 JCDiagnostic d = (JCDiagnostic)o; 4126 Object[] args = d.getArgs(); 4127 if (!d.getCode().matches(regex) || 4128 subTemplates.length != d.getArgs().length) { 4129 return false; 4130 } 4131 for (int i = 0; i < args.length ; i++) { 4132 if (!subTemplates[i].matches(args[i])) { 4133 return false; 4134 } 4135 } 4136 return true; 4137 } 4138 } 4139 4140 /** 4141 * Common rewriter for all argument mismatch simplifications. 4142 */ 4143 static class ArgMismatchRewriter implements DiagnosticRewriter { 4144 4145 /** the index of the subdiagnostic to be used as primary. */ 4146 int causeIndex; 4147 4148 public ArgMismatchRewriter(int causeIndex) { 4149 this.causeIndex = causeIndex; 4150 } 4151 4152 @Override 4153 public JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags, 4154 DiagnosticPosition preferedPos, DiagnosticSource preferredSource, 4155 DiagnosticType preferredKind, JCDiagnostic d) { 4156 JCDiagnostic cause = (JCDiagnostic)d.getArgs()[causeIndex]; 4157 return diags.create(preferredKind, preferredSource, d.getDiagnosticPosition(), 4158 "prob.found.req", cause); 4159 } 4160 } 4161 4162 /** a dummy template that match any diagnostic argument */ 4163 static final Template skip = new Template("") { 4164 @Override 4165 boolean matches(Object d) { 4166 return true; 4167 } 4168 }; 4169 4170 /** template for matching inference-free arguments mismatch failures */ 4171 static final Template argMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip); 4172 4173 /** template for matching inference related arguments mismatch failures */ 4174 static final Template inferArgMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip, skip) { 4175 @Override 4176 boolean matches(Object o) { 4177 if (!super.matches(o)) { 4178 return false; 4179 } 4180 JCDiagnostic d = (JCDiagnostic)o; 4181 @SuppressWarnings("unchecked") 4182 List<Type> tvars = (List<Type>)d.getArgs()[0]; 4183 return !containsAny(d, tvars); 4184 } 4185 4186 BiPredicate<Object, List<Type>> containsPredicate = (o, ts) -> { 4187 if (o instanceof Type) { 4188 return ((Type)o).containsAny(ts); 4189 } else if (o instanceof JCDiagnostic) { 4190 return containsAny((JCDiagnostic)o, ts); 4191 } else { 4192 return false; 4193 } 4194 }; 4195 4196 boolean containsAny(JCDiagnostic d, List<Type> ts) { 4197 return Stream.of(d.getArgs()) 4198 .anyMatch(o -> containsPredicate.test(o, ts)); 4199 } 4200 }; 4201 4202 /** rewriter map used for method resolution simplification */ 4203 static final Map<Template, DiagnosticRewriter> rewriters = new LinkedHashMap<>(); 4204 4205 static { 4206 rewriters.put(argMismatchTemplate, new ArgMismatchRewriter(0)); 4207 rewriters.put(inferArgMismatchTemplate, new ArgMismatchRewriter(1)); 4208 } 4209 4210 /** 4211 * Main entry point for diagnostic rewriting - given a diagnostic, see if any templates matches it, 4212 * and rewrite it accordingly. 4213 */ 4214 static JCDiagnostic rewrite(JCDiagnostic.Factory diags, DiagnosticPosition pos, DiagnosticSource source, 4215 DiagnosticType dkind, JCDiagnostic d) { 4216 for (Map.Entry<Template, DiagnosticRewriter> _entry : rewriters.entrySet()) { 4217 if (_entry.getKey().matches(d)) { 4218 JCDiagnostic simpleDiag = 4219 _entry.getValue().rewriteDiagnostic(diags, pos, source, dkind, d); 4220 simpleDiag.setFlag(DiagnosticFlag.COMPRESSED); 4221 return simpleDiag; 4222 } 4223 } 4224 return null; 4225 } 4226 } 4227 4228 enum MethodResolutionPhase { 4229 BASIC(false, false), 4230 BOX(true, false), 4231 VARARITY(true, true) { 4232 @Override 4233 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) { 4234 //Check invariants (see {@code LookupHelper.shouldStop}) 4235 Assert.check(bestSoFar.kind.isOverloadError() && bestSoFar.kind != AMBIGUOUS); 4236 if (!sym.kind.isOverloadError()) { 4237 //varargs resolution successful 4238 return sym; 4239 } else { 4240 //pick best error 4241 switch (bestSoFar.kind) { 4242 case WRONG_MTH: 4243 case WRONG_MTHS: 4244 //Override previous errors if they were caused by argument mismatch. 4245 //This generally means preferring current symbols - but we need to pay 4246 //attention to the fact that the varargs lookup returns 'less' candidates 4247 //than the previous rounds, and adjust that accordingly. 4248 switch (sym.kind) { 4249 case WRONG_MTH: 4250 //if the previous round matched more than one method, return that 4251 //result instead 4252 return bestSoFar.kind == WRONG_MTHS ? 4253 bestSoFar : sym; 4254 case ABSENT_MTH: 4255 //do not override erroneous symbol if the arity lookup did not 4256 //match any method 4257 return bestSoFar; 4258 case WRONG_MTHS: 4259 default: 4260 //safe to override 4261 return sym; 4262 } 4263 default: 4264 //otherwise, return first error 4265 return bestSoFar; 4266 } 4267 } 4268 } 4269 }; 4270 4271 final boolean isBoxingRequired; 4272 final boolean isVarargsRequired; 4273 4274 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) { 4275 this.isBoxingRequired = isBoxingRequired; 4276 this.isVarargsRequired = isVarargsRequired; 4277 } 4278 4279 public boolean isBoxingRequired() { 4280 return isBoxingRequired; 4281 } 4282 4283 public boolean isVarargsRequired() { 4284 return isVarargsRequired; 4285 } 4286 4287 public Symbol mergeResults(Symbol prev, Symbol sym) { 4288 return sym; 4289 } 4290 } 4291 4292 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY); 4293 4294 /** 4295 * A resolution context is used to keep track of intermediate results of 4296 * overload resolution, such as list of method that are not applicable 4297 * (used to generate more precise diagnostics) and so on. Resolution contexts 4298 * can be nested - this means that when each overload resolution routine should 4299 * work within the resolution context it created. 4300 */ 4301 class MethodResolutionContext { 4302 4303 private List<Candidate> candidates = List.nil(); 4304 4305 MethodResolutionPhase step = null; 4306 4307 MethodCheck methodCheck = resolveMethodCheck; 4308 4309 private boolean internalResolution = false; 4310 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE; 4311 4312 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) { 4313 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null); 4314 candidates = candidates.append(c); 4315 } 4316 4317 void addApplicableCandidate(Symbol sym, Type mtype) { 4318 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype); 4319 candidates = candidates.append(c); 4320 } 4321 4322 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) { 4323 DeferredAttrContext parent = (pendingResult == null) 4324 ? deferredAttr.emptyDeferredAttrContext 4325 : pendingResult.checkContext.deferredAttrContext(); 4326 return deferredAttr.new DeferredAttrContext(attrMode, sym, step, 4327 inferenceContext, parent, warn); 4328 } 4329 4330 /** 4331 * This class represents an overload resolution candidate. There are two 4332 * kinds of candidates: applicable methods and inapplicable methods; 4333 * applicable methods have a pointer to the instantiated method type, 4334 * while inapplicable candidates contain further details about the 4335 * reason why the method has been considered inapplicable. 4336 */ 4337 @SuppressWarnings("overrides") 4338 class Candidate { 4339 4340 final MethodResolutionPhase step; 4341 final Symbol sym; 4342 final JCDiagnostic details; 4343 final Type mtype; 4344 4345 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) { 4346 this.step = step; 4347 this.sym = sym; 4348 this.details = details; 4349 this.mtype = mtype; 4350 } 4351 4352 @Override 4353 public boolean equals(Object o) { 4354 if (o instanceof Candidate) { 4355 Symbol s1 = this.sym; 4356 Symbol s2 = ((Candidate)o).sym; 4357 if ((s1 != s2 && 4358 (s1.overrides(s2, s1.owner.type.tsym, types, false) || 4359 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) || 4360 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner)) 4361 return true; 4362 } 4363 return false; 4364 } 4365 4366 boolean isApplicable() { 4367 return mtype != null; 4368 } 4369 } 4370 4371 DeferredAttr.AttrMode attrMode() { 4372 return attrMode; 4373 } 4374 4375 boolean internal() { 4376 return internalResolution; 4377 } 4378 } 4379 4380 MethodResolutionContext currentResolutionContext = null; 4381} 4382