Resolve.java revision 3023:3059496164ab
1/* 2 * Copyright (c) 1999, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26package com.sun.tools.javac.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.FreeTypeListener; 39import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate; 40import com.sun.tools.javac.comp.Resolve.MethodResolutionDiagHelper.Template; 41import com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind; 42import com.sun.tools.javac.jvm.*; 43import com.sun.tools.javac.main.Option; 44import com.sun.tools.javac.tree.*; 45import com.sun.tools.javac.tree.JCTree.*; 46import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind; 47import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*; 48import com.sun.tools.javac.util.*; 49import com.sun.tools.javac.util.DefinedBy.Api; 50import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag; 51import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition; 52import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType; 53 54import java.util.Arrays; 55import java.util.Collection; 56import java.util.EnumSet; 57import java.util.Iterator; 58import java.util.LinkedHashMap; 59import java.util.Map; 60import java.util.function.BiPredicate; 61import java.util.stream.Stream; 62 63import javax.lang.model.element.ElementVisitor; 64 65import static com.sun.tools.javac.code.Flags.*; 66import static com.sun.tools.javac.code.Flags.BLOCK; 67import static com.sun.tools.javac.code.Flags.STATIC; 68import static com.sun.tools.javac.code.Kinds.*; 69import static com.sun.tools.javac.code.Kinds.Kind.*; 70import static com.sun.tools.javac.code.TypeTag.*; 71import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*; 72import static com.sun.tools.javac.tree.JCTree.Tag.*; 73 74/** Helper class for name resolution, used mostly by the attribution phase. 75 * 76 * <p><b>This is NOT part of any supported API. 77 * If you write code that depends on this, you do so at your own risk. 78 * This code and its internal interfaces are subject to change or 79 * deletion without notice.</b> 80 */ 81public class Resolve { 82 protected static final Context.Key<Resolve> resolveKey = new Context.Key<>(); 83 84 Names names; 85 Log log; 86 Symtab syms; 87 Attr attr; 88 DeferredAttr deferredAttr; 89 Check chk; 90 Infer infer; 91 ClassFinder finder; 92 Types types; 93 JCDiagnostic.Factory diags; 94 public final boolean allowMethodHandles; 95 public final boolean allowFunctionalInterfaceMostSpecific; 96 public final boolean checkVarargsAccessAfterResolution; 97 private final boolean debugResolve; 98 private final boolean compactMethodDiags; 99 final EnumSet<VerboseResolutionMode> verboseResolutionMode; 100 101 WriteableScope polymorphicSignatureScope; 102 103 protected Resolve(Context context) { 104 context.put(resolveKey, this); 105 syms = Symtab.instance(context); 106 107 varNotFound = new SymbolNotFoundError(ABSENT_VAR); 108 methodNotFound = new SymbolNotFoundError(ABSENT_MTH); 109 typeNotFound = new SymbolNotFoundError(ABSENT_TYP); 110 referenceNotFound = new ReferenceLookupResult(methodNotFound, null); 111 112 names = Names.instance(context); 113 log = Log.instance(context); 114 attr = Attr.instance(context); 115 deferredAttr = DeferredAttr.instance(context); 116 chk = Check.instance(context); 117 infer = Infer.instance(context); 118 finder = ClassFinder.instance(context); 119 types = Types.instance(context); 120 diags = JCDiagnostic.Factory.instance(context); 121 Source source = Source.instance(context); 122 Options options = Options.instance(context); 123 debugResolve = options.isSet("debugresolve"); 124 compactMethodDiags = options.isSet(Option.XDIAGS, "compact") || 125 options.isUnset(Option.XDIAGS) && options.isUnset("rawDiagnostics"); 126 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options); 127 Target target = Target.instance(context); 128 allowMethodHandles = target.hasMethodHandles(); 129 allowFunctionalInterfaceMostSpecific = source.allowFunctionalInterfaceMostSpecific(); 130 checkVarargsAccessAfterResolution = 131 source.allowPostApplicabilityVarargsAccessCheck(); 132 polymorphicSignatureScope = WriteableScope.create(syms.noSymbol); 133 134 inapplicableMethodException = new InapplicableMethodException(diags); 135 } 136 137 /** error symbols, which are returned when resolution fails 138 */ 139 private final SymbolNotFoundError varNotFound; 140 private final SymbolNotFoundError methodNotFound; 141 private final SymbolNotFoundError typeNotFound; 142 143 /** empty reference lookup result */ 144 private final ReferenceLookupResult referenceNotFound; 145 146 public static Resolve instance(Context context) { 147 Resolve instance = context.get(resolveKey); 148 if (instance == null) 149 instance = new Resolve(context); 150 return instance; 151 } 152 153 private static Symbol bestOf(Symbol s1, 154 Symbol s2) { 155 return s1.kind.betterThan(s2.kind) ? s1 : s2; 156 } 157 158 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support"> 159 enum VerboseResolutionMode { 160 SUCCESS("success"), 161 FAILURE("failure"), 162 APPLICABLE("applicable"), 163 INAPPLICABLE("inapplicable"), 164 DEFERRED_INST("deferred-inference"), 165 PREDEF("predef"), 166 OBJECT_INIT("object-init"), 167 INTERNAL("internal"); 168 169 final String opt; 170 171 private VerboseResolutionMode(String opt) { 172 this.opt = opt; 173 } 174 175 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) { 176 String s = opts.get("verboseResolution"); 177 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class); 178 if (s == null) return res; 179 if (s.contains("all")) { 180 res = EnumSet.allOf(VerboseResolutionMode.class); 181 } 182 Collection<String> args = Arrays.asList(s.split(",")); 183 for (VerboseResolutionMode mode : values()) { 184 if (args.contains(mode.opt)) { 185 res.add(mode); 186 } else if (args.contains("-" + mode.opt)) { 187 res.remove(mode); 188 } 189 } 190 return res; 191 } 192 } 193 194 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site, 195 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) { 196 boolean success = !bestSoFar.kind.isResolutionError(); 197 198 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) { 199 return; 200 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) { 201 return; 202 } 203 204 if (bestSoFar.name == names.init && 205 bestSoFar.owner == syms.objectType.tsym && 206 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) { 207 return; //skip diags for Object constructor resolution 208 } else if (site == syms.predefClass.type && 209 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) { 210 return; //skip spurious diags for predef symbols (i.e. operators) 211 } else if (currentResolutionContext.internalResolution && 212 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) { 213 return; 214 } 215 216 int pos = 0; 217 int mostSpecificPos = -1; 218 ListBuffer<JCDiagnostic> subDiags = new ListBuffer<>(); 219 for (Candidate c : currentResolutionContext.candidates) { 220 if (currentResolutionContext.step != c.step || 221 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) || 222 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) { 223 continue; 224 } else { 225 subDiags.append(c.isApplicable() ? 226 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) : 227 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details)); 228 if (c.sym == bestSoFar) 229 mostSpecificPos = pos; 230 pos++; 231 } 232 } 233 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1"; 234 List<Type> argtypes2 = argtypes.map(deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step)); 235 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name, 236 site.tsym, mostSpecificPos, currentResolutionContext.step, 237 methodArguments(argtypes2), 238 methodArguments(typeargtypes)); 239 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList()); 240 log.report(d); 241 } 242 243 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) { 244 JCDiagnostic subDiag = null; 245 if (sym.type.hasTag(FORALL)) { 246 subDiag = diags.fragment("partial.inst.sig", inst); 247 } 248 249 String key = subDiag == null ? 250 "applicable.method.found" : 251 "applicable.method.found.1"; 252 253 return diags.fragment(key, pos, sym, subDiag); 254 } 255 256 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) { 257 return diags.fragment("not.applicable.method.found", pos, sym, subDiag); 258 } 259 // </editor-fold> 260 261/* ************************************************************************ 262 * Identifier resolution 263 *************************************************************************/ 264 265 /** An environment is "static" if its static level is greater than 266 * the one of its outer environment 267 */ 268 protected static boolean isStatic(Env<AttrContext> env) { 269 return env.outer != null && env.info.staticLevel > env.outer.info.staticLevel; 270 } 271 272 /** An environment is an "initializer" if it is a constructor or 273 * an instance initializer. 274 */ 275 static boolean isInitializer(Env<AttrContext> env) { 276 Symbol owner = env.info.scope.owner; 277 return owner.isConstructor() || 278 owner.owner.kind == TYP && 279 (owner.kind == VAR || 280 owner.kind == MTH && (owner.flags() & BLOCK) != 0) && 281 (owner.flags() & STATIC) == 0; 282 } 283 284 /** Is class accessible in given evironment? 285 * @param env The current environment. 286 * @param c The class whose accessibility is checked. 287 */ 288 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) { 289 return isAccessible(env, c, false); 290 } 291 292 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) { 293 boolean isAccessible = false; 294 switch ((short)(c.flags() & AccessFlags)) { 295 case PRIVATE: 296 isAccessible = 297 env.enclClass.sym.outermostClass() == 298 c.owner.outermostClass(); 299 break; 300 case 0: 301 isAccessible = 302 env.toplevel.packge == c.owner // fast special case 303 || 304 env.toplevel.packge == c.packge() 305 || 306 // Hack: this case is added since synthesized default constructors 307 // of anonymous classes should be allowed to access 308 // classes which would be inaccessible otherwise. 309 env.enclMethod != null && 310 (env.enclMethod.mods.flags & ANONCONSTR) != 0; 311 break; 312 default: // error recovery 313 case PUBLIC: 314 isAccessible = true; 315 break; 316 case PROTECTED: 317 isAccessible = 318 env.toplevel.packge == c.owner // fast special case 319 || 320 env.toplevel.packge == c.packge() 321 || 322 isInnerSubClass(env.enclClass.sym, c.owner); 323 break; 324 } 325 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ? 326 isAccessible : 327 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner); 328 } 329 //where 330 /** Is given class a subclass of given base class, or an inner class 331 * of a subclass? 332 * Return null if no such class exists. 333 * @param c The class which is the subclass or is contained in it. 334 * @param base The base class 335 */ 336 private boolean isInnerSubClass(ClassSymbol c, Symbol base) { 337 while (c != null && !c.isSubClass(base, types)) { 338 c = c.owner.enclClass(); 339 } 340 return c != null; 341 } 342 343 boolean isAccessible(Env<AttrContext> env, Type t) { 344 return isAccessible(env, t, false); 345 } 346 347 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) { 348 return (t.hasTag(ARRAY)) 349 ? isAccessible(env, types.cvarUpperBound(types.elemtype(t))) 350 : isAccessible(env, t.tsym, checkInner); 351 } 352 353 /** Is symbol accessible as a member of given type in given environment? 354 * @param env The current environment. 355 * @param site The type of which the tested symbol is regarded 356 * as a member. 357 * @param sym The symbol. 358 */ 359 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) { 360 return isAccessible(env, site, sym, false); 361 } 362 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) { 363 if (sym.name == names.init && sym.owner != site.tsym) return false; 364 switch ((short)(sym.flags() & AccessFlags)) { 365 case PRIVATE: 366 return 367 (env.enclClass.sym == sym.owner // fast special case 368 || 369 env.enclClass.sym.outermostClass() == 370 sym.owner.outermostClass()) 371 && 372 sym.isInheritedIn(site.tsym, types); 373 case 0: 374 return 375 (env.toplevel.packge == sym.owner.owner // fast special case 376 || 377 env.toplevel.packge == sym.packge()) 378 && 379 isAccessible(env, site, checkInner) 380 && 381 sym.isInheritedIn(site.tsym, types) 382 && 383 notOverriddenIn(site, sym); 384 case PROTECTED: 385 return 386 (env.toplevel.packge == sym.owner.owner // fast special case 387 || 388 env.toplevel.packge == sym.packge() 389 || 390 isProtectedAccessible(sym, env.enclClass.sym, site) 391 || 392 // OK to select instance method or field from 'super' or type name 393 // (but type names should be disallowed elsewhere!) 394 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP) 395 && 396 isAccessible(env, site, checkInner) 397 && 398 notOverriddenIn(site, sym); 399 default: // this case includes erroneous combinations as well 400 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym); 401 } 402 } 403 //where 404 /* `sym' is accessible only if not overridden by 405 * another symbol which is a member of `site' 406 * (because, if it is overridden, `sym' is not strictly 407 * speaking a member of `site'). A polymorphic signature method 408 * cannot be overridden (e.g. MH.invokeExact(Object[])). 409 */ 410 private boolean notOverriddenIn(Type site, Symbol sym) { 411 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic()) 412 return true; 413 else { 414 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true); 415 return (s2 == null || s2 == sym || sym.owner == s2.owner || 416 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym))); 417 } 418 } 419 //where 420 /** Is given protected symbol accessible if it is selected from given site 421 * and the selection takes place in given class? 422 * @param sym The symbol with protected access 423 * @param c The class where the access takes place 424 * @site The type of the qualifier 425 */ 426 private 427 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) { 428 Type newSite = site.hasTag(TYPEVAR) ? site.getUpperBound() : site; 429 while (c != null && 430 !(c.isSubClass(sym.owner, types) && 431 (c.flags() & INTERFACE) == 0 && 432 // In JLS 2e 6.6.2.1, the subclass restriction applies 433 // only to instance fields and methods -- types are excluded 434 // regardless of whether they are declared 'static' or not. 435 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || newSite.tsym.isSubClass(c, types)))) 436 c = c.owner.enclClass(); 437 return c != null; 438 } 439 440 /** 441 * Performs a recursive scan of a type looking for accessibility problems 442 * from current attribution environment 443 */ 444 void checkAccessibleType(Env<AttrContext> env, Type t) { 445 accessibilityChecker.visit(t, env); 446 } 447 448 /** 449 * Accessibility type-visitor 450 */ 451 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker = 452 new Types.SimpleVisitor<Void, Env<AttrContext>>() { 453 454 void visit(List<Type> ts, Env<AttrContext> env) { 455 for (Type t : ts) { 456 visit(t, env); 457 } 458 } 459 460 public Void visitType(Type t, Env<AttrContext> env) { 461 return null; 462 } 463 464 @Override 465 public Void visitArrayType(ArrayType t, Env<AttrContext> env) { 466 visit(t.elemtype, env); 467 return null; 468 } 469 470 @Override 471 public Void visitClassType(ClassType t, Env<AttrContext> env) { 472 visit(t.getTypeArguments(), env); 473 if (!isAccessible(env, t, true)) { 474 accessBase(new AccessError(t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true); 475 } 476 return null; 477 } 478 479 @Override 480 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) { 481 visit(t.type, env); 482 return null; 483 } 484 485 @Override 486 public Void visitMethodType(MethodType t, Env<AttrContext> env) { 487 visit(t.getParameterTypes(), env); 488 visit(t.getReturnType(), env); 489 visit(t.getThrownTypes(), env); 490 return null; 491 } 492 }; 493 494 /** Try to instantiate the type of a method so that it fits 495 * given type arguments and argument types. If successful, return 496 * the method's instantiated type, else return null. 497 * The instantiation will take into account an additional leading 498 * formal parameter if the method is an instance method seen as a member 499 * of an under determined site. In this case, we treat site as an additional 500 * parameter and the parameters of the class containing the method as 501 * additional type variables that get instantiated. 502 * 503 * @param env The current environment 504 * @param site The type of which the method is a member. 505 * @param m The method symbol. 506 * @param argtypes The invocation's given value arguments. 507 * @param typeargtypes The invocation's given type arguments. 508 * @param allowBoxing Allow boxing conversions of arguments. 509 * @param useVarargs Box trailing arguments into an array for varargs. 510 */ 511 Type rawInstantiate(Env<AttrContext> env, 512 Type site, 513 Symbol m, 514 ResultInfo resultInfo, 515 List<Type> argtypes, 516 List<Type> typeargtypes, 517 boolean allowBoxing, 518 boolean useVarargs, 519 Warner warn) throws Infer.InferenceException { 520 Type mt = types.memberType(site, m); 521 // tvars is the list of formal type variables for which type arguments 522 // need to inferred. 523 List<Type> tvars = List.nil(); 524 if (typeargtypes == null) typeargtypes = List.nil(); 525 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) { 526 // This is not a polymorphic method, but typeargs are supplied 527 // which is fine, see JLS 15.12.2.1 528 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) { 529 ForAll pmt = (ForAll) mt; 530 if (typeargtypes.length() != pmt.tvars.length()) 531 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args 532 // Check type arguments are within bounds 533 List<Type> formals = pmt.tvars; 534 List<Type> actuals = typeargtypes; 535 while (formals.nonEmpty() && actuals.nonEmpty()) { 536 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head), 537 pmt.tvars, typeargtypes); 538 for (; bounds.nonEmpty(); bounds = bounds.tail) { 539 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn)) 540 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds); 541 } 542 formals = formals.tail; 543 actuals = actuals.tail; 544 } 545 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes); 546 } else if (mt.hasTag(FORALL)) { 547 ForAll pmt = (ForAll) mt; 548 List<Type> tvars1 = types.newInstances(pmt.tvars); 549 tvars = tvars.appendList(tvars1); 550 mt = types.subst(pmt.qtype, pmt.tvars, tvars1); 551 } 552 553 // find out whether we need to go the slow route via infer 554 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/ 555 for (List<Type> l = argtypes; 556 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded; 557 l = l.tail) { 558 if (l.head.hasTag(FORALL)) instNeeded = true; 559 } 560 561 if (instNeeded) { 562 return infer.instantiateMethod(env, 563 tvars, 564 (MethodType)mt, 565 resultInfo, 566 (MethodSymbol)m, 567 argtypes, 568 allowBoxing, 569 useVarargs, 570 currentResolutionContext, 571 warn); 572 } 573 574 DeferredAttr.DeferredAttrContext dc = currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn); 575 currentResolutionContext.methodCheck.argumentsAcceptable(env, dc, 576 argtypes, mt.getParameterTypes(), warn); 577 dc.complete(); 578 return mt; 579 } 580 581 Type checkMethod(Env<AttrContext> env, 582 Type site, 583 Symbol m, 584 ResultInfo resultInfo, 585 List<Type> argtypes, 586 List<Type> typeargtypes, 587 Warner warn) { 588 MethodResolutionContext prevContext = currentResolutionContext; 589 try { 590 currentResolutionContext = new MethodResolutionContext(); 591 currentResolutionContext.attrMode = DeferredAttr.AttrMode.CHECK; 592 if (env.tree.hasTag(JCTree.Tag.REFERENCE)) { 593 //method/constructor references need special check class 594 //to handle inference variables in 'argtypes' (might happen 595 //during an unsticking round) 596 currentResolutionContext.methodCheck = 597 new MethodReferenceCheck(resultInfo.checkContext.inferenceContext()); 598 } 599 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase; 600 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes, 601 step.isBoxingRequired(), step.isVarargsRequired(), warn); 602 } 603 finally { 604 currentResolutionContext = prevContext; 605 } 606 } 607 608 /** Same but returns null instead throwing a NoInstanceException 609 */ 610 Type instantiate(Env<AttrContext> env, 611 Type site, 612 Symbol m, 613 ResultInfo resultInfo, 614 List<Type> argtypes, 615 List<Type> typeargtypes, 616 boolean allowBoxing, 617 boolean useVarargs, 618 Warner warn) { 619 try { 620 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes, 621 allowBoxing, useVarargs, warn); 622 } catch (InapplicableMethodException ex) { 623 return null; 624 } 625 } 626 627 /** 628 * This interface defines an entry point that should be used to perform a 629 * method check. A method check usually consist in determining as to whether 630 * a set of types (actuals) is compatible with another set of types (formals). 631 * Since the notion of compatibility can vary depending on the circumstances, 632 * this interfaces allows to easily add new pluggable method check routines. 633 */ 634 interface MethodCheck { 635 /** 636 * Main method check routine. A method check usually consist in determining 637 * as to whether a set of types (actuals) is compatible with another set of 638 * types (formals). If an incompatibility is found, an unchecked exception 639 * is assumed to be thrown. 640 */ 641 void argumentsAcceptable(Env<AttrContext> env, 642 DeferredAttrContext deferredAttrContext, 643 List<Type> argtypes, 644 List<Type> formals, 645 Warner warn); 646 647 /** 648 * Retrieve the method check object that will be used during a 649 * most specific check. 650 */ 651 MethodCheck mostSpecificCheck(List<Type> actuals); 652 } 653 654 /** 655 * Helper enum defining all method check diagnostics (used by resolveMethodCheck). 656 */ 657 enum MethodCheckDiag { 658 /** 659 * Actuals and formals differs in length. 660 */ 661 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"), 662 /** 663 * An actual is incompatible with a formal. 664 */ 665 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"), 666 /** 667 * An actual is incompatible with the varargs element type. 668 */ 669 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"), 670 /** 671 * The varargs element type is inaccessible. 672 */ 673 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type"); 674 675 final String basicKey; 676 final String inferKey; 677 678 MethodCheckDiag(String basicKey, String inferKey) { 679 this.basicKey = basicKey; 680 this.inferKey = inferKey; 681 } 682 683 String regex() { 684 return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey); 685 } 686 } 687 688 /** 689 * Dummy method check object. All methods are deemed applicable, regardless 690 * of their formal parameter types. 691 */ 692 MethodCheck nilMethodCheck = new MethodCheck() { 693 public void argumentsAcceptable(Env<AttrContext> env, DeferredAttrContext deferredAttrContext, List<Type> argtypes, List<Type> formals, Warner warn) { 694 //do nothing - method always applicable regardless of actuals 695 } 696 697 public MethodCheck mostSpecificCheck(List<Type> actuals) { 698 return this; 699 } 700 }; 701 702 /** 703 * Base class for 'real' method checks. The class defines the logic for 704 * iterating through formals and actuals and provides and entry point 705 * that can be used by subclasses in order to define the actual check logic. 706 */ 707 abstract class AbstractMethodCheck implements MethodCheck { 708 @Override 709 public void argumentsAcceptable(final Env<AttrContext> env, 710 DeferredAttrContext deferredAttrContext, 711 List<Type> argtypes, 712 List<Type> formals, 713 Warner warn) { 714 //should we expand formals? 715 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired(); 716 List<JCExpression> trees = TreeInfo.args(env.tree); 717 718 //inference context used during this method check 719 InferenceContext inferenceContext = deferredAttrContext.inferenceContext; 720 721 Type varargsFormal = useVarargs ? formals.last() : null; 722 723 if (varargsFormal == null && 724 argtypes.size() != formals.size()) { 725 reportMC(env.tree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args 726 } 727 728 while (argtypes.nonEmpty() && formals.head != varargsFormal) { 729 DiagnosticPosition pos = trees != null ? trees.head : null; 730 checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn); 731 argtypes = argtypes.tail; 732 formals = formals.tail; 733 trees = trees != null ? trees.tail : trees; 734 } 735 736 if (formals.head != varargsFormal) { 737 reportMC(env.tree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args 738 } 739 740 if (useVarargs) { 741 //note: if applicability check is triggered by most specific test, 742 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5) 743 final Type elt = types.elemtype(varargsFormal); 744 while (argtypes.nonEmpty()) { 745 DiagnosticPosition pos = trees != null ? trees.head : null; 746 checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn); 747 argtypes = argtypes.tail; 748 trees = trees != null ? trees.tail : trees; 749 } 750 } 751 } 752 753 /** 754 * Does the actual argument conforms to the corresponding formal? 755 */ 756 abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn); 757 758 protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) { 759 boolean inferDiag = inferenceContext != infer.emptyContext; 760 InapplicableMethodException ex = inferDiag ? 761 infer.inferenceException : inapplicableMethodException; 762 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) { 763 Object[] args2 = new Object[args.length + 1]; 764 System.arraycopy(args, 0, args2, 1, args.length); 765 args2[0] = inferenceContext.inferenceVars(); 766 args = args2; 767 } 768 String key = inferDiag ? diag.inferKey : diag.basicKey; 769 throw ex.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args)); 770 } 771 772 public MethodCheck mostSpecificCheck(List<Type> actuals) { 773 return nilMethodCheck; 774 } 775 776 } 777 778 /** 779 * Arity-based method check. A method is applicable if the number of actuals 780 * supplied conforms to the method signature. 781 */ 782 MethodCheck arityMethodCheck = new AbstractMethodCheck() { 783 @Override 784 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) { 785 //do nothing - actual always compatible to formals 786 } 787 788 @Override 789 public String toString() { 790 return "arityMethodCheck"; 791 } 792 }; 793 794 List<Type> dummyArgs(int length) { 795 ListBuffer<Type> buf = new ListBuffer<>(); 796 for (int i = 0 ; i < length ; i++) { 797 buf.append(Type.noType); 798 } 799 return buf.toList(); 800 } 801 802 /** 803 * Main method applicability routine. Given a list of actual types A, 804 * a list of formal types F, determines whether the types in A are 805 * compatible (by method invocation conversion) with the types in F. 806 * 807 * Since this routine is shared between overload resolution and method 808 * type-inference, a (possibly empty) inference context is used to convert 809 * formal types to the corresponding 'undet' form ahead of a compatibility 810 * check so that constraints can be propagated and collected. 811 * 812 * Moreover, if one or more types in A is a deferred type, this routine uses 813 * DeferredAttr in order to perform deferred attribution. If one or more actual 814 * deferred types are stuck, they are placed in a queue and revisited later 815 * after the remainder of the arguments have been seen. If this is not sufficient 816 * to 'unstuck' the argument, a cyclic inference error is called out. 817 * 818 * A method check handler (see above) is used in order to report errors. 819 */ 820 MethodCheck resolveMethodCheck = new AbstractMethodCheck() { 821 822 @Override 823 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) { 824 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn); 825 mresult.check(pos, actual); 826 } 827 828 @Override 829 public void argumentsAcceptable(final Env<AttrContext> env, 830 DeferredAttrContext deferredAttrContext, 831 List<Type> argtypes, 832 List<Type> formals, 833 Warner warn) { 834 super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn); 835 // should we check varargs element type accessibility? 836 if (deferredAttrContext.phase.isVarargsRequired()) { 837 if (deferredAttrContext.mode == AttrMode.CHECK || !checkVarargsAccessAfterResolution) { 838 varargsAccessible(env, types.elemtype(formals.last()), deferredAttrContext.inferenceContext); 839 } 840 } 841 } 842 843 /** 844 * Test that the runtime array element type corresponding to 't' is accessible. 't' should be the 845 * varargs element type of either the method invocation type signature (after inference completes) 846 * or the method declaration signature (before inference completes). 847 */ 848 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) { 849 if (inferenceContext.free(t)) { 850 inferenceContext.addFreeTypeListener(List.of(t), new FreeTypeListener() { 851 @Override 852 public void typesInferred(InferenceContext inferenceContext) { 853 varargsAccessible(env, inferenceContext.asInstType(t), inferenceContext); 854 } 855 }); 856 } else { 857 if (!isAccessible(env, types.erasure(t))) { 858 Symbol location = env.enclClass.sym; 859 reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location); 860 } 861 } 862 } 863 864 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to, 865 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) { 866 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) { 867 MethodCheckDiag methodDiag = varargsCheck ? 868 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH; 869 870 @Override 871 public void report(DiagnosticPosition pos, JCDiagnostic details) { 872 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details); 873 } 874 }; 875 return new MethodResultInfo(to, checkContext); 876 } 877 878 @Override 879 public MethodCheck mostSpecificCheck(List<Type> actuals) { 880 return new MostSpecificCheck(actuals); 881 } 882 883 @Override 884 public String toString() { 885 return "resolveMethodCheck"; 886 } 887 }; 888 889 /** 890 * This class handles method reference applicability checks; since during 891 * these checks it's sometime possible to have inference variables on 892 * the actual argument types list, the method applicability check must be 893 * extended so that inference variables are 'opened' as needed. 894 */ 895 class MethodReferenceCheck extends AbstractMethodCheck { 896 897 InferenceContext pendingInferenceContext; 898 899 MethodReferenceCheck(InferenceContext pendingInferenceContext) { 900 this.pendingInferenceContext = pendingInferenceContext; 901 } 902 903 @Override 904 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) { 905 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn); 906 mresult.check(pos, actual); 907 } 908 909 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to, 910 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) { 911 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) { 912 MethodCheckDiag methodDiag = varargsCheck ? 913 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH; 914 915 @Override 916 public boolean compatible(Type found, Type req, Warner warn) { 917 found = pendingInferenceContext.asUndetVar(found); 918 if (found.hasTag(UNDETVAR) && req.isPrimitive()) { 919 req = types.boxedClass(req).type; 920 } 921 return super.compatible(found, req, warn); 922 } 923 924 @Override 925 public void report(DiagnosticPosition pos, JCDiagnostic details) { 926 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details); 927 } 928 }; 929 return new MethodResultInfo(to, checkContext); 930 } 931 932 @Override 933 public MethodCheck mostSpecificCheck(List<Type> actuals) { 934 return new MostSpecificCheck(actuals); 935 } 936 937 @Override 938 public String toString() { 939 return "MethodReferenceCheck"; 940 } 941 } 942 943 /** 944 * Check context to be used during method applicability checks. A method check 945 * context might contain inference variables. 946 */ 947 abstract class MethodCheckContext implements CheckContext { 948 949 boolean strict; 950 DeferredAttrContext deferredAttrContext; 951 Warner rsWarner; 952 953 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) { 954 this.strict = strict; 955 this.deferredAttrContext = deferredAttrContext; 956 this.rsWarner = rsWarner; 957 } 958 959 public boolean compatible(Type found, Type req, Warner warn) { 960 InferenceContext inferenceContext = deferredAttrContext.inferenceContext; 961 return strict ? 962 types.isSubtypeUnchecked(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn) : 963 types.isConvertible(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn); 964 } 965 966 public void report(DiagnosticPosition pos, JCDiagnostic details) { 967 throw inapplicableMethodException.setMessage(details); 968 } 969 970 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) { 971 return rsWarner; 972 } 973 974 public InferenceContext inferenceContext() { 975 return deferredAttrContext.inferenceContext; 976 } 977 978 public DeferredAttrContext deferredAttrContext() { 979 return deferredAttrContext; 980 } 981 982 @Override 983 public String toString() { 984 return "MethodCheckContext"; 985 } 986 } 987 988 /** 989 * ResultInfo class to be used during method applicability checks. Check 990 * for deferred types goes through special path. 991 */ 992 class MethodResultInfo extends ResultInfo { 993 994 public MethodResultInfo(Type pt, CheckContext checkContext) { 995 attr.super(KindSelector.VAL, pt, checkContext); 996 } 997 998 @Override 999 protected Type check(DiagnosticPosition pos, Type found) { 1000 if (found.hasTag(DEFERRED)) { 1001 DeferredType dt = (DeferredType)found; 1002 return dt.check(this); 1003 } else { 1004 Type uResult = U(found); 1005 Type capturedType = pos == null || pos.getTree() == null ? 1006 types.capture(uResult) : 1007 checkContext.inferenceContext() 1008 .cachedCapture(pos.getTree(), uResult, true); 1009 return super.check(pos, chk.checkNonVoid(pos, capturedType)); 1010 } 1011 } 1012 1013 /** 1014 * javac has a long-standing 'simplification' (see 6391995): 1015 * given an actual argument type, the method check is performed 1016 * on its upper bound. This leads to inconsistencies when an 1017 * argument type is checked against itself. For example, given 1018 * a type-variable T, it is not true that {@code U(T) <: T}, 1019 * so we need to guard against that. 1020 */ 1021 private Type U(Type found) { 1022 return found == pt ? 1023 found : types.cvarUpperBound(found); 1024 } 1025 1026 @Override 1027 protected MethodResultInfo dup(Type newPt) { 1028 return new MethodResultInfo(newPt, checkContext); 1029 } 1030 1031 @Override 1032 protected ResultInfo dup(CheckContext newContext) { 1033 return new MethodResultInfo(pt, newContext); 1034 } 1035 } 1036 1037 /** 1038 * Most specific method applicability routine. Given a list of actual types A, 1039 * a list of formal types F1, and a list of formal types F2, the routine determines 1040 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t. 1041 * argument types A. 1042 */ 1043 class MostSpecificCheck implements MethodCheck { 1044 1045 List<Type> actuals; 1046 1047 MostSpecificCheck(List<Type> actuals) { 1048 this.actuals = actuals; 1049 } 1050 1051 @Override 1052 public void argumentsAcceptable(final Env<AttrContext> env, 1053 DeferredAttrContext deferredAttrContext, 1054 List<Type> formals1, 1055 List<Type> formals2, 1056 Warner warn) { 1057 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired()); 1058 while (formals2.nonEmpty()) { 1059 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head); 1060 mresult.check(null, formals1.head); 1061 formals1 = formals1.tail; 1062 formals2 = formals2.tail; 1063 actuals = actuals.isEmpty() ? actuals : actuals.tail; 1064 } 1065 } 1066 1067 /** 1068 * Create a method check context to be used during the most specific applicability check 1069 */ 1070 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext, 1071 Warner rsWarner, Type actual) { 1072 return attr.new ResultInfo(KindSelector.VAL, to, 1073 new MostSpecificCheckContext(deferredAttrContext, rsWarner, actual)); 1074 } 1075 1076 /** 1077 * Subclass of method check context class that implements most specific 1078 * method conversion. If the actual type under analysis is a deferred type 1079 * a full blown structural analysis is carried out. 1080 */ 1081 class MostSpecificCheckContext extends MethodCheckContext { 1082 1083 Type actual; 1084 1085 public MostSpecificCheckContext(DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) { 1086 super(true, deferredAttrContext, rsWarner); 1087 this.actual = actual; 1088 } 1089 1090 public boolean compatible(Type found, Type req, Warner warn) { 1091 if (allowFunctionalInterfaceMostSpecific && 1092 unrelatedFunctionalInterfaces(found, req) && 1093 (actual != null && actual.getTag() == DEFERRED)) { 1094 DeferredType dt = (DeferredType) actual; 1095 DeferredType.SpeculativeCache.Entry e = 1096 dt.speculativeCache.get(deferredAttrContext.msym, deferredAttrContext.phase); 1097 if (e != null && e.speculativeTree != deferredAttr.stuckTree) { 1098 return functionalInterfaceMostSpecific(found, req, e.speculativeTree); 1099 } 1100 } 1101 return compatibleBySubtyping(found, req); 1102 } 1103 1104 private boolean compatibleBySubtyping(Type found, Type req) { 1105 if (!strict && found.isPrimitive() != req.isPrimitive()) { 1106 found = found.isPrimitive() ? types.boxedClass(found).type : types.unboxedType(found); 1107 } 1108 return types.isSubtypeNoCapture(found, deferredAttrContext.inferenceContext.asUndetVar(req)); 1109 } 1110 1111 /** Whether {@code t} and {@code s} are unrelated functional interface types. */ 1112 private boolean unrelatedFunctionalInterfaces(Type t, Type s) { 1113 return types.isFunctionalInterface(t.tsym) && 1114 types.isFunctionalInterface(s.tsym) && 1115 types.asSuper(t, s.tsym) == null && 1116 types.asSuper(s, t.tsym) == null; 1117 } 1118 1119 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */ 1120 private boolean functionalInterfaceMostSpecific(Type t, Type s, JCTree tree) { 1121 FunctionalInterfaceMostSpecificChecker msc = new FunctionalInterfaceMostSpecificChecker(t, s); 1122 msc.scan(tree); 1123 return msc.result; 1124 } 1125 1126 /** 1127 * Tests whether one functional interface type can be considered more specific 1128 * than another unrelated functional interface type for the scanned expression. 1129 */ 1130 class FunctionalInterfaceMostSpecificChecker extends DeferredAttr.PolyScanner { 1131 1132 final Type t; 1133 final Type s; 1134 boolean result; 1135 1136 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */ 1137 FunctionalInterfaceMostSpecificChecker(Type t, Type s) { 1138 this.t = t; 1139 this.s = s; 1140 result = true; 1141 } 1142 1143 @Override 1144 void skip(JCTree tree) { 1145 result &= false; 1146 } 1147 1148 @Override 1149 public void visitConditional(JCConditional tree) { 1150 scan(tree.truepart); 1151 scan(tree.falsepart); 1152 } 1153 1154 @Override 1155 public void visitReference(JCMemberReference tree) { 1156 Type desc_t = types.findDescriptorType(t); 1157 Type desc_s = types.findDescriptorType(s); 1158 // use inference variables here for more-specific inference (18.5.4) 1159 if (!types.isSameTypes(desc_t.getParameterTypes(), 1160 inferenceContext().asUndetVars(desc_s.getParameterTypes()))) { 1161 result &= false; 1162 } else { 1163 // compare return types 1164 Type ret_t = desc_t.getReturnType(); 1165 Type ret_s = desc_s.getReturnType(); 1166 if (ret_s.hasTag(VOID)) { 1167 result &= true; 1168 } else if (ret_t.hasTag(VOID)) { 1169 result &= false; 1170 } else if (ret_t.isPrimitive() != ret_s.isPrimitive()) { 1171 boolean retValIsPrimitive = 1172 tree.refPolyKind == PolyKind.STANDALONE && 1173 tree.sym.type.getReturnType().isPrimitive(); 1174 result &= (retValIsPrimitive == ret_t.isPrimitive()) && 1175 (retValIsPrimitive != ret_s.isPrimitive()); 1176 } else { 1177 result &= compatibleBySubtyping(ret_t, ret_s); 1178 } 1179 } 1180 } 1181 1182 @Override 1183 public void visitLambda(JCLambda tree) { 1184 Type desc_t = types.findDescriptorType(t); 1185 Type desc_s = types.findDescriptorType(s); 1186 // use inference variables here for more-specific inference (18.5.4) 1187 if (!types.isSameTypes(desc_t.getParameterTypes(), 1188 inferenceContext().asUndetVars(desc_s.getParameterTypes()))) { 1189 result &= false; 1190 } else { 1191 // compare return types 1192 Type ret_t = desc_t.getReturnType(); 1193 Type ret_s = desc_s.getReturnType(); 1194 if (ret_s.hasTag(VOID)) { 1195 result &= true; 1196 } else if (ret_t.hasTag(VOID)) { 1197 result &= false; 1198 } else if (unrelatedFunctionalInterfaces(ret_t, ret_s)) { 1199 for (JCExpression expr : lambdaResults(tree)) { 1200 result &= functionalInterfaceMostSpecific(ret_t, ret_s, expr); 1201 } 1202 } else if (ret_t.isPrimitive() != ret_s.isPrimitive()) { 1203 for (JCExpression expr : lambdaResults(tree)) { 1204 boolean retValIsPrimitive = expr.isStandalone() && expr.type.isPrimitive(); 1205 result &= (retValIsPrimitive == ret_t.isPrimitive()) && 1206 (retValIsPrimitive != ret_s.isPrimitive()); 1207 } 1208 } else { 1209 result &= compatibleBySubtyping(ret_t, ret_s); 1210 } 1211 } 1212 } 1213 //where 1214 1215 private List<JCExpression> lambdaResults(JCLambda lambda) { 1216 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) { 1217 return List.of((JCExpression) lambda.body); 1218 } else { 1219 final ListBuffer<JCExpression> buffer = new ListBuffer<>(); 1220 DeferredAttr.LambdaReturnScanner lambdaScanner = 1221 new DeferredAttr.LambdaReturnScanner() { 1222 @Override 1223 public void visitReturn(JCReturn tree) { 1224 if (tree.expr != null) { 1225 buffer.append(tree.expr); 1226 } 1227 } 1228 }; 1229 lambdaScanner.scan(lambda.body); 1230 return buffer.toList(); 1231 } 1232 } 1233 } 1234 1235 } 1236 1237 public MethodCheck mostSpecificCheck(List<Type> actuals) { 1238 Assert.error("Cannot get here!"); 1239 return null; 1240 } 1241 } 1242 1243 public static class InapplicableMethodException extends RuntimeException { 1244 private static final long serialVersionUID = 0; 1245 1246 JCDiagnostic diagnostic; 1247 JCDiagnostic.Factory diags; 1248 1249 InapplicableMethodException(JCDiagnostic.Factory diags) { 1250 this.diagnostic = null; 1251 this.diags = diags; 1252 } 1253 InapplicableMethodException setMessage() { 1254 return setMessage((JCDiagnostic)null); 1255 } 1256 InapplicableMethodException setMessage(String key) { 1257 return setMessage(key != null ? diags.fragment(key) : null); 1258 } 1259 InapplicableMethodException setMessage(String key, Object... args) { 1260 return setMessage(key != null ? diags.fragment(key, args) : null); 1261 } 1262 InapplicableMethodException setMessage(JCDiagnostic diag) { 1263 this.diagnostic = diag; 1264 return this; 1265 } 1266 1267 public JCDiagnostic getDiagnostic() { 1268 return diagnostic; 1269 } 1270 } 1271 private final InapplicableMethodException inapplicableMethodException; 1272 1273/* *************************************************************************** 1274 * Symbol lookup 1275 * the following naming conventions for arguments are used 1276 * 1277 * env is the environment where the symbol was mentioned 1278 * site is the type of which the symbol is a member 1279 * name is the symbol's name 1280 * if no arguments are given 1281 * argtypes are the value arguments, if we search for a method 1282 * 1283 * If no symbol was found, a ResolveError detailing the problem is returned. 1284 ****************************************************************************/ 1285 1286 /** Find field. Synthetic fields are always skipped. 1287 * @param env The current environment. 1288 * @param site The original type from where the selection takes place. 1289 * @param name The name of the field. 1290 * @param c The class to search for the field. This is always 1291 * a superclass or implemented interface of site's class. 1292 */ 1293 Symbol findField(Env<AttrContext> env, 1294 Type site, 1295 Name name, 1296 TypeSymbol c) { 1297 while (c.type.hasTag(TYPEVAR)) 1298 c = c.type.getUpperBound().tsym; 1299 Symbol bestSoFar = varNotFound; 1300 Symbol sym; 1301 for (Symbol s : c.members().getSymbolsByName(name)) { 1302 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) { 1303 return isAccessible(env, site, s) 1304 ? s : new AccessError(env, site, s); 1305 } 1306 } 1307 Type st = types.supertype(c.type); 1308 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) { 1309 sym = findField(env, site, name, st.tsym); 1310 bestSoFar = bestOf(bestSoFar, sym); 1311 } 1312 for (List<Type> l = types.interfaces(c.type); 1313 bestSoFar.kind != AMBIGUOUS && l.nonEmpty(); 1314 l = l.tail) { 1315 sym = findField(env, site, name, l.head.tsym); 1316 if (bestSoFar.exists() && sym.exists() && 1317 sym.owner != bestSoFar.owner) 1318 bestSoFar = new AmbiguityError(bestSoFar, sym); 1319 else 1320 bestSoFar = bestOf(bestSoFar, sym); 1321 } 1322 return bestSoFar; 1323 } 1324 1325 /** Resolve a field identifier, throw a fatal error if not found. 1326 * @param pos The position to use for error reporting. 1327 * @param env The environment current at the method invocation. 1328 * @param site The type of the qualifying expression, in which 1329 * identifier is searched. 1330 * @param name The identifier's name. 1331 */ 1332 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env, 1333 Type site, Name name) { 1334 Symbol sym = findField(env, site, name, site.tsym); 1335 if (sym.kind == VAR) return (VarSymbol)sym; 1336 else throw new FatalError( 1337 diags.fragment("fatal.err.cant.locate.field", 1338 name)); 1339 } 1340 1341 /** Find unqualified variable or field with given name. 1342 * Synthetic fields always skipped. 1343 * @param env The current environment. 1344 * @param name The name of the variable or field. 1345 */ 1346 Symbol findVar(Env<AttrContext> env, Name name) { 1347 Symbol bestSoFar = varNotFound; 1348 Env<AttrContext> env1 = env; 1349 boolean staticOnly = false; 1350 while (env1.outer != null) { 1351 Symbol sym = null; 1352 if (isStatic(env1)) staticOnly = true; 1353 for (Symbol s : env1.info.scope.getSymbolsByName(name)) { 1354 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) { 1355 sym = s; 1356 break; 1357 } 1358 } 1359 if (sym == null) { 1360 sym = findField(env1, env1.enclClass.sym.type, name, env1.enclClass.sym); 1361 } 1362 if (sym.exists()) { 1363 if (staticOnly && 1364 sym.kind == VAR && 1365 sym.owner.kind == TYP && 1366 (sym.flags() & STATIC) == 0) 1367 return new StaticError(sym); 1368 else 1369 return sym; 1370 } else { 1371 bestSoFar = bestOf(bestSoFar, sym); 1372 } 1373 1374 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true; 1375 env1 = env1.outer; 1376 } 1377 1378 Symbol sym = findField(env, syms.predefClass.type, name, syms.predefClass); 1379 if (sym.exists()) 1380 return sym; 1381 if (bestSoFar.exists()) 1382 return bestSoFar; 1383 1384 Symbol origin = null; 1385 for (Scope sc : new Scope[] { env.toplevel.namedImportScope, env.toplevel.starImportScope }) { 1386 for (Symbol currentSymbol : sc.getSymbolsByName(name)) { 1387 if (currentSymbol.kind != VAR) 1388 continue; 1389 // invariant: sym.kind == Symbol.Kind.VAR 1390 if (!bestSoFar.kind.isResolutionError() && 1391 currentSymbol.owner != bestSoFar.owner) 1392 return new AmbiguityError(bestSoFar, currentSymbol); 1393 else if (!bestSoFar.kind.betterThan(VAR)) { 1394 origin = sc.getOrigin(currentSymbol).owner; 1395 bestSoFar = isAccessible(env, origin.type, currentSymbol) 1396 ? currentSymbol : new AccessError(env, origin.type, currentSymbol); 1397 } 1398 } 1399 if (bestSoFar.exists()) break; 1400 } 1401 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type) 1402 return bestSoFar.clone(origin); 1403 else 1404 return bestSoFar; 1405 } 1406 1407 Warner noteWarner = new Warner(); 1408 1409 /** Select the best method for a call site among two choices. 1410 * @param env The current environment. 1411 * @param site The original type from where the 1412 * selection takes place. 1413 * @param argtypes The invocation's value arguments, 1414 * @param typeargtypes The invocation's type arguments, 1415 * @param sym Proposed new best match. 1416 * @param bestSoFar Previously found best match. 1417 * @param allowBoxing Allow boxing conversions of arguments. 1418 * @param useVarargs Box trailing arguments into an array for varargs. 1419 */ 1420 @SuppressWarnings("fallthrough") 1421 Symbol selectBest(Env<AttrContext> env, 1422 Type site, 1423 List<Type> argtypes, 1424 List<Type> typeargtypes, 1425 Symbol sym, 1426 Symbol bestSoFar, 1427 boolean allowBoxing, 1428 boolean useVarargs) { 1429 if (sym.kind == ERR || 1430 !sym.isInheritedIn(site.tsym, types)) { 1431 return bestSoFar; 1432 } else if (useVarargs && (sym.flags() & VARARGS) == 0) { 1433 return bestSoFar.kind.isResolutionError() ? 1434 new BadVarargsMethod((ResolveError)bestSoFar.baseSymbol()) : 1435 bestSoFar; 1436 } 1437 Assert.check(!sym.kind.isResolutionError()); 1438 try { 1439 types.noWarnings.clear(); 1440 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes, 1441 allowBoxing, useVarargs, types.noWarnings); 1442 currentResolutionContext.addApplicableCandidate(sym, mt); 1443 } catch (InapplicableMethodException ex) { 1444 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic()); 1445 switch (bestSoFar.kind) { 1446 case ABSENT_MTH: 1447 return new InapplicableSymbolError(currentResolutionContext); 1448 case WRONG_MTH: 1449 bestSoFar = new InapplicableSymbolsError(currentResolutionContext); 1450 default: 1451 return bestSoFar; 1452 } 1453 } 1454 if (!isAccessible(env, site, sym)) { 1455 return (bestSoFar.kind == ABSENT_MTH) 1456 ? new AccessError(env, site, sym) 1457 : bestSoFar; 1458 } 1459 return (bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS) 1460 ? sym 1461 : mostSpecific(argtypes, sym, bestSoFar, env, site, useVarargs); 1462 } 1463 1464 /* Return the most specific of the two methods for a call, 1465 * given that both are accessible and applicable. 1466 * @param m1 A new candidate for most specific. 1467 * @param m2 The previous most specific candidate. 1468 * @param env The current environment. 1469 * @param site The original type from where the selection 1470 * takes place. 1471 * @param allowBoxing Allow boxing conversions of arguments. 1472 * @param useVarargs Box trailing arguments into an array for varargs. 1473 */ 1474 Symbol mostSpecific(List<Type> argtypes, Symbol m1, 1475 Symbol m2, 1476 Env<AttrContext> env, 1477 final Type site, 1478 boolean useVarargs) { 1479 switch (m2.kind) { 1480 case MTH: 1481 if (m1 == m2) return m1; 1482 boolean m1SignatureMoreSpecific = 1483 signatureMoreSpecific(argtypes, env, site, m1, m2, useVarargs); 1484 boolean m2SignatureMoreSpecific = 1485 signatureMoreSpecific(argtypes, env, site, m2, m1, useVarargs); 1486 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) { 1487 Type mt1 = types.memberType(site, m1); 1488 Type mt2 = types.memberType(site, m2); 1489 if (!types.overrideEquivalent(mt1, mt2)) 1490 return ambiguityError(m1, m2); 1491 1492 // same signature; select (a) the non-bridge method, or 1493 // (b) the one that overrides the other, or (c) the concrete 1494 // one, or (d) merge both abstract signatures 1495 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE)) 1496 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1; 1497 1498 // if one overrides or hides the other, use it 1499 TypeSymbol m1Owner = (TypeSymbol)m1.owner; 1500 TypeSymbol m2Owner = (TypeSymbol)m2.owner; 1501 if (types.asSuper(m1Owner.type, m2Owner) != null && 1502 ((m1.owner.flags_field & INTERFACE) == 0 || 1503 (m2.owner.flags_field & INTERFACE) != 0) && 1504 m1.overrides(m2, m1Owner, types, false)) 1505 return m1; 1506 if (types.asSuper(m2Owner.type, m1Owner) != null && 1507 ((m2.owner.flags_field & INTERFACE) == 0 || 1508 (m1.owner.flags_field & INTERFACE) != 0) && 1509 m2.overrides(m1, m2Owner, types, false)) 1510 return m2; 1511 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0; 1512 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0; 1513 if (m1Abstract && !m2Abstract) return m2; 1514 if (m2Abstract && !m1Abstract) return m1; 1515 // both abstract or both concrete 1516 return ambiguityError(m1, m2); 1517 } 1518 if (m1SignatureMoreSpecific) return m1; 1519 if (m2SignatureMoreSpecific) return m2; 1520 return ambiguityError(m1, m2); 1521 case AMBIGUOUS: 1522 //compare m1 to ambiguous methods in m2 1523 AmbiguityError e = (AmbiguityError)m2.baseSymbol(); 1524 boolean m1MoreSpecificThanAnyAmbiguous = true; 1525 boolean allAmbiguousMoreSpecificThanM1 = true; 1526 for (Symbol s : e.ambiguousSyms) { 1527 Symbol moreSpecific = mostSpecific(argtypes, m1, s, env, site, useVarargs); 1528 m1MoreSpecificThanAnyAmbiguous &= moreSpecific == m1; 1529 allAmbiguousMoreSpecificThanM1 &= moreSpecific == s; 1530 } 1531 if (m1MoreSpecificThanAnyAmbiguous) 1532 return m1; 1533 //if m1 is more specific than some ambiguous methods, but other ambiguous methods are 1534 //more specific than m1, add it as a new ambiguous method: 1535 if (!allAmbiguousMoreSpecificThanM1) 1536 e.addAmbiguousSymbol(m1); 1537 return e; 1538 default: 1539 throw new AssertionError(); 1540 } 1541 } 1542 //where 1543 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean useVarargs) { 1544 noteWarner.clear(); 1545 int maxLength = Math.max( 1546 Math.max(m1.type.getParameterTypes().length(), actuals.length()), 1547 m2.type.getParameterTypes().length()); 1548 MethodResolutionContext prevResolutionContext = currentResolutionContext; 1549 try { 1550 currentResolutionContext = new MethodResolutionContext(); 1551 currentResolutionContext.step = prevResolutionContext.step; 1552 currentResolutionContext.methodCheck = 1553 prevResolutionContext.methodCheck.mostSpecificCheck(actuals); 1554 Type mst = instantiate(env, site, m2, null, 1555 adjustArgs(types.cvarLowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null, 1556 false, useVarargs, noteWarner); 1557 return mst != null && 1558 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED); 1559 } finally { 1560 currentResolutionContext = prevResolutionContext; 1561 } 1562 } 1563 1564 List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) { 1565 if ((msym.flags() & VARARGS) != 0 && allowVarargs) { 1566 Type varargsElem = types.elemtype(args.last()); 1567 if (varargsElem == null) { 1568 Assert.error("Bad varargs = " + args.last() + " " + msym); 1569 } 1570 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse(); 1571 while (newArgs.length() < length) { 1572 newArgs = newArgs.append(newArgs.last()); 1573 } 1574 return newArgs; 1575 } else { 1576 return args; 1577 } 1578 } 1579 //where 1580 Type mostSpecificReturnType(Type mt1, Type mt2) { 1581 Type rt1 = mt1.getReturnType(); 1582 Type rt2 = mt2.getReturnType(); 1583 1584 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL)) { 1585 //if both are generic methods, adjust return type ahead of subtyping check 1586 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments()); 1587 } 1588 //first use subtyping, then return type substitutability 1589 if (types.isSubtype(rt1, rt2)) { 1590 return mt1; 1591 } else if (types.isSubtype(rt2, rt1)) { 1592 return mt2; 1593 } else if (types.returnTypeSubstitutable(mt1, mt2)) { 1594 return mt1; 1595 } else if (types.returnTypeSubstitutable(mt2, mt1)) { 1596 return mt2; 1597 } else { 1598 return null; 1599 } 1600 } 1601 //where 1602 Symbol ambiguityError(Symbol m1, Symbol m2) { 1603 if (((m1.flags() | m2.flags()) & CLASH) != 0) { 1604 return (m1.flags() & CLASH) == 0 ? m1 : m2; 1605 } else { 1606 return new AmbiguityError(m1, m2); 1607 } 1608 } 1609 1610 Symbol findMethodInScope(Env<AttrContext> env, 1611 Type site, 1612 Name name, 1613 List<Type> argtypes, 1614 List<Type> typeargtypes, 1615 Scope sc, 1616 Symbol bestSoFar, 1617 boolean allowBoxing, 1618 boolean useVarargs, 1619 boolean abstractok) { 1620 for (Symbol s : sc.getSymbolsByName(name, new LookupFilter(abstractok))) { 1621 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s, 1622 bestSoFar, allowBoxing, useVarargs); 1623 } 1624 return bestSoFar; 1625 } 1626 //where 1627 class LookupFilter implements Filter<Symbol> { 1628 1629 boolean abstractOk; 1630 1631 LookupFilter(boolean abstractOk) { 1632 this.abstractOk = abstractOk; 1633 } 1634 1635 public boolean accepts(Symbol s) { 1636 long flags = s.flags(); 1637 return s.kind == MTH && 1638 (flags & SYNTHETIC) == 0 && 1639 (abstractOk || 1640 (flags & DEFAULT) != 0 || 1641 (flags & ABSTRACT) == 0); 1642 } 1643 } 1644 1645 /** Find best qualified method matching given name, type and value 1646 * arguments. 1647 * @param env The current environment. 1648 * @param site The original type from where the selection 1649 * takes place. 1650 * @param name The method's name. 1651 * @param argtypes The method's value arguments. 1652 * @param typeargtypes The method's type arguments 1653 * @param allowBoxing Allow boxing conversions of arguments. 1654 * @param useVarargs Box trailing arguments into an array for varargs. 1655 */ 1656 Symbol findMethod(Env<AttrContext> env, 1657 Type site, 1658 Name name, 1659 List<Type> argtypes, 1660 List<Type> typeargtypes, 1661 boolean allowBoxing, 1662 boolean useVarargs) { 1663 Symbol bestSoFar = methodNotFound; 1664 bestSoFar = findMethod(env, 1665 site, 1666 name, 1667 argtypes, 1668 typeargtypes, 1669 site.tsym.type, 1670 bestSoFar, 1671 allowBoxing, 1672 useVarargs); 1673 return bestSoFar; 1674 } 1675 // where 1676 private Symbol findMethod(Env<AttrContext> env, 1677 Type site, 1678 Name name, 1679 List<Type> argtypes, 1680 List<Type> typeargtypes, 1681 Type intype, 1682 Symbol bestSoFar, 1683 boolean allowBoxing, 1684 boolean useVarargs) { 1685 @SuppressWarnings({"unchecked","rawtypes"}) 1686 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() }; 1687 1688 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK; 1689 for (TypeSymbol s : superclasses(intype)) { 1690 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes, 1691 s.members(), bestSoFar, allowBoxing, useVarargs, true); 1692 if (name == names.init) return bestSoFar; 1693 iphase = (iphase == null) ? null : iphase.update(s, this); 1694 if (iphase != null) { 1695 for (Type itype : types.interfaces(s.type)) { 1696 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]); 1697 } 1698 } 1699 } 1700 1701 Symbol concrete = bestSoFar.kind.isValid() && 1702 (bestSoFar.flags() & ABSTRACT) == 0 ? 1703 bestSoFar : methodNotFound; 1704 1705 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) { 1706 //keep searching for abstract methods 1707 for (Type itype : itypes[iphase2.ordinal()]) { 1708 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure()) 1709 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK && 1710 (itype.tsym.flags() & DEFAULT) == 0) continue; 1711 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes, 1712 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, true); 1713 if (concrete != bestSoFar && 1714 concrete.kind.isValid() && 1715 bestSoFar.kind.isValid() && 1716 types.isSubSignature(concrete.type, bestSoFar.type)) { 1717 //this is an hack - as javac does not do full membership checks 1718 //most specific ends up comparing abstract methods that might have 1719 //been implemented by some concrete method in a subclass and, 1720 //because of raw override, it is possible for an abstract method 1721 //to be more specific than the concrete method - so we need 1722 //to explicitly call that out (see CR 6178365) 1723 bestSoFar = concrete; 1724 } 1725 } 1726 } 1727 return bestSoFar; 1728 } 1729 1730 enum InterfaceLookupPhase { 1731 ABSTRACT_OK() { 1732 @Override 1733 InterfaceLookupPhase update(Symbol s, Resolve rs) { 1734 //We should not look for abstract methods if receiver is a concrete class 1735 //(as concrete classes are expected to implement all abstracts coming 1736 //from superinterfaces) 1737 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) { 1738 return this; 1739 } else { 1740 return DEFAULT_OK; 1741 } 1742 } 1743 }, 1744 DEFAULT_OK() { 1745 @Override 1746 InterfaceLookupPhase update(Symbol s, Resolve rs) { 1747 return this; 1748 } 1749 }; 1750 1751 abstract InterfaceLookupPhase update(Symbol s, Resolve rs); 1752 } 1753 1754 /** 1755 * Return an Iterable object to scan the superclasses of a given type. 1756 * It's crucial that the scan is done lazily, as we don't want to accidentally 1757 * access more supertypes than strictly needed (as this could trigger completion 1758 * errors if some of the not-needed supertypes are missing/ill-formed). 1759 */ 1760 Iterable<TypeSymbol> superclasses(final Type intype) { 1761 return new Iterable<TypeSymbol>() { 1762 public Iterator<TypeSymbol> iterator() { 1763 return new Iterator<TypeSymbol>() { 1764 1765 List<TypeSymbol> seen = List.nil(); 1766 TypeSymbol currentSym = symbolFor(intype); 1767 TypeSymbol prevSym = null; 1768 1769 public boolean hasNext() { 1770 if (currentSym == syms.noSymbol) { 1771 currentSym = symbolFor(types.supertype(prevSym.type)); 1772 } 1773 return currentSym != null; 1774 } 1775 1776 public TypeSymbol next() { 1777 prevSym = currentSym; 1778 currentSym = syms.noSymbol; 1779 Assert.check(prevSym != null || prevSym != syms.noSymbol); 1780 return prevSym; 1781 } 1782 1783 public void remove() { 1784 throw new UnsupportedOperationException(); 1785 } 1786 1787 TypeSymbol symbolFor(Type t) { 1788 if (!t.hasTag(CLASS) && 1789 !t.hasTag(TYPEVAR)) { 1790 return null; 1791 } 1792 t = types.skipTypeVars(t, false); 1793 if (seen.contains(t.tsym)) { 1794 //degenerate case in which we have a circular 1795 //class hierarchy - because of ill-formed classfiles 1796 return null; 1797 } 1798 seen = seen.prepend(t.tsym); 1799 return t.tsym; 1800 } 1801 }; 1802 } 1803 }; 1804 } 1805 1806 /** Find unqualified method matching given name, type and value arguments. 1807 * @param env The current environment. 1808 * @param name The method's name. 1809 * @param argtypes The method's value arguments. 1810 * @param typeargtypes The method's type arguments. 1811 * @param allowBoxing Allow boxing conversions of arguments. 1812 * @param useVarargs Box trailing arguments into an array for varargs. 1813 */ 1814 Symbol findFun(Env<AttrContext> env, Name name, 1815 List<Type> argtypes, List<Type> typeargtypes, 1816 boolean allowBoxing, boolean useVarargs) { 1817 Symbol bestSoFar = methodNotFound; 1818 Env<AttrContext> env1 = env; 1819 boolean staticOnly = false; 1820 while (env1.outer != null) { 1821 if (isStatic(env1)) staticOnly = true; 1822 Symbol sym = findMethod( 1823 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes, 1824 allowBoxing, useVarargs); 1825 if (sym.exists()) { 1826 if (staticOnly && 1827 sym.kind == MTH && 1828 sym.owner.kind == TYP && 1829 (sym.flags() & STATIC) == 0) return new StaticError(sym); 1830 else return sym; 1831 } else { 1832 bestSoFar = bestOf(bestSoFar, sym); 1833 } 1834 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true; 1835 env1 = env1.outer; 1836 } 1837 1838 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes, 1839 typeargtypes, allowBoxing, useVarargs); 1840 if (sym.exists()) 1841 return sym; 1842 1843 for (Symbol currentSym : env.toplevel.namedImportScope.getSymbolsByName(name)) { 1844 Symbol origin = env.toplevel.namedImportScope.getOrigin(currentSym).owner; 1845 if (currentSym.kind == MTH) { 1846 if (currentSym.owner.type != origin.type) 1847 currentSym = currentSym.clone(origin); 1848 if (!isAccessible(env, origin.type, currentSym)) 1849 currentSym = new AccessError(env, origin.type, currentSym); 1850 bestSoFar = selectBest(env, origin.type, 1851 argtypes, typeargtypes, 1852 currentSym, bestSoFar, 1853 allowBoxing, useVarargs); 1854 } 1855 } 1856 if (bestSoFar.exists()) 1857 return bestSoFar; 1858 1859 for (Symbol currentSym : env.toplevel.starImportScope.getSymbolsByName(name)) { 1860 Symbol origin = env.toplevel.starImportScope.getOrigin(currentSym).owner; 1861 if (currentSym.kind == MTH) { 1862 if (currentSym.owner.type != origin.type) 1863 currentSym = currentSym.clone(origin); 1864 if (!isAccessible(env, origin.type, currentSym)) 1865 currentSym = new AccessError(env, origin.type, currentSym); 1866 bestSoFar = selectBest(env, origin.type, 1867 argtypes, typeargtypes, 1868 currentSym, bestSoFar, 1869 allowBoxing, useVarargs); 1870 } 1871 } 1872 return bestSoFar; 1873 } 1874 1875 /** Load toplevel or member class with given fully qualified name and 1876 * verify that it is accessible. 1877 * @param env The current environment. 1878 * @param name The fully qualified name of the class to be loaded. 1879 */ 1880 Symbol loadClass(Env<AttrContext> env, Name name) { 1881 try { 1882 ClassSymbol c = finder.loadClass(name); 1883 return isAccessible(env, c) ? c : new AccessError(c); 1884 } catch (ClassFinder.BadClassFile err) { 1885 throw err; 1886 } catch (CompletionFailure ex) { 1887 return typeNotFound; 1888 } 1889 } 1890 1891 1892 /** 1893 * Find a type declared in a scope (not inherited). Return null 1894 * if none is found. 1895 * @param env The current environment. 1896 * @param site The original type from where the selection takes 1897 * place. 1898 * @param name The type's name. 1899 * @param c The class to search for the member type. This is 1900 * always a superclass or implemented interface of 1901 * site's class. 1902 */ 1903 Symbol findImmediateMemberType(Env<AttrContext> env, 1904 Type site, 1905 Name name, 1906 TypeSymbol c) { 1907 for (Symbol sym : c.members().getSymbolsByName(name)) { 1908 if (sym.kind == TYP) { 1909 return isAccessible(env, site, sym) 1910 ? sym 1911 : new AccessError(env, site, sym); 1912 } 1913 } 1914 return typeNotFound; 1915 } 1916 1917 /** Find a member type inherited from a superclass or interface. 1918 * @param env The current environment. 1919 * @param site The original type from where the selection takes 1920 * place. 1921 * @param name The type's name. 1922 * @param c The class to search for the member type. This is 1923 * always a superclass or implemented interface of 1924 * site's class. 1925 */ 1926 Symbol findInheritedMemberType(Env<AttrContext> env, 1927 Type site, 1928 Name name, 1929 TypeSymbol c) { 1930 Symbol bestSoFar = typeNotFound; 1931 Symbol sym; 1932 Type st = types.supertype(c.type); 1933 if (st != null && st.hasTag(CLASS)) { 1934 sym = findMemberType(env, site, name, st.tsym); 1935 bestSoFar = bestOf(bestSoFar, sym); 1936 } 1937 for (List<Type> l = types.interfaces(c.type); 1938 bestSoFar.kind != AMBIGUOUS && l.nonEmpty(); 1939 l = l.tail) { 1940 sym = findMemberType(env, site, name, l.head.tsym); 1941 if (!bestSoFar.kind.isResolutionError() && 1942 !sym.kind.isResolutionError() && 1943 sym.owner != bestSoFar.owner) 1944 bestSoFar = new AmbiguityError(bestSoFar, sym); 1945 else 1946 bestSoFar = bestOf(bestSoFar, sym); 1947 } 1948 return bestSoFar; 1949 } 1950 1951 /** Find qualified member type. 1952 * @param env The current environment. 1953 * @param site The original type from where the selection takes 1954 * place. 1955 * @param name The type's name. 1956 * @param c The class to search for the member type. This is 1957 * always a superclass or implemented interface of 1958 * site's class. 1959 */ 1960 Symbol findMemberType(Env<AttrContext> env, 1961 Type site, 1962 Name name, 1963 TypeSymbol c) { 1964 Symbol sym = findImmediateMemberType(env, site, name, c); 1965 1966 if (sym != typeNotFound) 1967 return sym; 1968 1969 return findInheritedMemberType(env, site, name, c); 1970 1971 } 1972 1973 /** Find a global type in given scope and load corresponding class. 1974 * @param env The current environment. 1975 * @param scope The scope in which to look for the type. 1976 * @param name The type's name. 1977 */ 1978 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) { 1979 Symbol bestSoFar = typeNotFound; 1980 for (Symbol s : scope.getSymbolsByName(name)) { 1981 Symbol sym = loadClass(env, s.flatName()); 1982 if (bestSoFar.kind == TYP && sym.kind == TYP && 1983 bestSoFar != sym) 1984 return new AmbiguityError(bestSoFar, sym); 1985 else 1986 bestSoFar = bestOf(bestSoFar, sym); 1987 } 1988 return bestSoFar; 1989 } 1990 1991 Symbol findTypeVar(Env<AttrContext> env, Name name, boolean staticOnly) { 1992 for (Symbol sym : env.info.scope.getSymbolsByName(name)) { 1993 if (sym.kind == TYP) { 1994 if (staticOnly && 1995 sym.type.hasTag(TYPEVAR) && 1996 sym.owner.kind == TYP) 1997 return new StaticError(sym); 1998 return sym; 1999 } 2000 } 2001 return typeNotFound; 2002 } 2003 2004 /** Find an unqualified type symbol. 2005 * @param env The current environment. 2006 * @param name The type's name. 2007 */ 2008 Symbol findType(Env<AttrContext> env, Name name) { 2009 if (name == names.empty) 2010 return typeNotFound; // do not allow inadvertent "lookup" of anonymous types 2011 Symbol bestSoFar = typeNotFound; 2012 Symbol sym; 2013 boolean staticOnly = false; 2014 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) { 2015 if (isStatic(env1)) staticOnly = true; 2016 // First, look for a type variable and the first member type 2017 final Symbol tyvar = findTypeVar(env1, name, staticOnly); 2018 sym = findImmediateMemberType(env1, env1.enclClass.sym.type, 2019 name, env1.enclClass.sym); 2020 2021 // Return the type variable if we have it, and have no 2022 // immediate member, OR the type variable is for a method. 2023 if (tyvar != typeNotFound) { 2024 if (env.baseClause || sym == typeNotFound || 2025 (tyvar.kind == TYP && tyvar.exists() && 2026 tyvar.owner.kind == MTH)) { 2027 return tyvar; 2028 } 2029 } 2030 2031 // If the environment is a class def, finish up, 2032 // otherwise, do the entire findMemberType 2033 if (sym == typeNotFound) 2034 sym = findInheritedMemberType(env1, env1.enclClass.sym.type, 2035 name, env1.enclClass.sym); 2036 2037 if (staticOnly && sym.kind == TYP && 2038 sym.type.hasTag(CLASS) && 2039 sym.type.getEnclosingType().hasTag(CLASS) && 2040 env1.enclClass.sym.type.isParameterized() && 2041 sym.type.getEnclosingType().isParameterized()) 2042 return new StaticError(sym); 2043 else if (sym.exists()) return sym; 2044 else bestSoFar = bestOf(bestSoFar, sym); 2045 2046 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass; 2047 if ((encl.sym.flags() & STATIC) != 0) 2048 staticOnly = true; 2049 } 2050 2051 if (!env.tree.hasTag(IMPORT)) { 2052 sym = findGlobalType(env, env.toplevel.namedImportScope, name); 2053 if (sym.exists()) return sym; 2054 else bestSoFar = bestOf(bestSoFar, sym); 2055 2056 sym = findGlobalType(env, env.toplevel.packge.members(), name); 2057 if (sym.exists()) return sym; 2058 else bestSoFar = bestOf(bestSoFar, sym); 2059 2060 sym = findGlobalType(env, env.toplevel.starImportScope, name); 2061 if (sym.exists()) return sym; 2062 else bestSoFar = bestOf(bestSoFar, sym); 2063 } 2064 2065 return bestSoFar; 2066 } 2067 2068 /** Find an unqualified identifier which matches a specified kind set. 2069 * @param env The current environment. 2070 * @param name The identifier's name. 2071 * @param kind Indicates the possible symbol kinds 2072 * (a subset of VAL, TYP, PCK). 2073 */ 2074 Symbol findIdent(Env<AttrContext> env, Name name, KindSelector kind) { 2075 Symbol bestSoFar = typeNotFound; 2076 Symbol sym; 2077 2078 if (kind.contains(KindSelector.VAL)) { 2079 sym = findVar(env, name); 2080 if (sym.exists()) return sym; 2081 else bestSoFar = bestOf(bestSoFar, sym); 2082 } 2083 2084 if (kind.contains(KindSelector.TYP)) { 2085 sym = findType(env, name); 2086 2087 if (sym.exists()) return sym; 2088 else bestSoFar = bestOf(bestSoFar, sym); 2089 } 2090 2091 if (kind.contains(KindSelector.PCK)) 2092 return syms.enterPackage(name); 2093 else return bestSoFar; 2094 } 2095 2096 /** Find an identifier in a package which matches a specified kind set. 2097 * @param env The current environment. 2098 * @param name The identifier's name. 2099 * @param kind Indicates the possible symbol kinds 2100 * (a nonempty subset of TYP, PCK). 2101 */ 2102 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck, 2103 Name name, KindSelector kind) { 2104 Name fullname = TypeSymbol.formFullName(name, pck); 2105 Symbol bestSoFar = typeNotFound; 2106 PackageSymbol pack = null; 2107 if (kind.contains(KindSelector.PCK)) { 2108 pack = syms.enterPackage(fullname); 2109 if (pack.exists()) return pack; 2110 } 2111 if (kind.contains(KindSelector.TYP)) { 2112 Symbol sym = loadClass(env, fullname); 2113 if (sym.exists()) { 2114 // don't allow programs to use flatnames 2115 if (name == sym.name) return sym; 2116 } 2117 else bestSoFar = bestOf(bestSoFar, sym); 2118 } 2119 return (pack != null) ? pack : bestSoFar; 2120 } 2121 2122 /** Find an identifier among the members of a given type `site'. 2123 * @param env The current environment. 2124 * @param site The type containing the symbol to be found. 2125 * @param name The identifier's name. 2126 * @param kind Indicates the possible symbol kinds 2127 * (a subset of VAL, TYP). 2128 */ 2129 Symbol findIdentInType(Env<AttrContext> env, Type site, 2130 Name name, KindSelector kind) { 2131 Symbol bestSoFar = typeNotFound; 2132 Symbol sym; 2133 if (kind.contains(KindSelector.VAL)) { 2134 sym = findField(env, site, name, site.tsym); 2135 if (sym.exists()) return sym; 2136 else bestSoFar = bestOf(bestSoFar, sym); 2137 } 2138 2139 if (kind.contains(KindSelector.TYP)) { 2140 sym = findMemberType(env, site, name, site.tsym); 2141 if (sym.exists()) return sym; 2142 else bestSoFar = bestOf(bestSoFar, sym); 2143 } 2144 return bestSoFar; 2145 } 2146 2147/* *************************************************************************** 2148 * Access checking 2149 * The following methods convert ResolveErrors to ErrorSymbols, issuing 2150 * an error message in the process 2151 ****************************************************************************/ 2152 2153 /** If `sym' is a bad symbol: report error and return errSymbol 2154 * else pass through unchanged, 2155 * additional arguments duplicate what has been used in trying to find the 2156 * symbol {@literal (--> flyweight pattern)}. This improves performance since we 2157 * expect misses to happen frequently. 2158 * 2159 * @param sym The symbol that was found, or a ResolveError. 2160 * @param pos The position to use for error reporting. 2161 * @param location The symbol the served as a context for this lookup 2162 * @param site The original type from where the selection took place. 2163 * @param name The symbol's name. 2164 * @param qualified Did we get here through a qualified expression resolution? 2165 * @param argtypes The invocation's value arguments, 2166 * if we looked for a method. 2167 * @param typeargtypes The invocation's type arguments, 2168 * if we looked for a method. 2169 * @param logResolveHelper helper class used to log resolve errors 2170 */ 2171 Symbol accessInternal(Symbol sym, 2172 DiagnosticPosition pos, 2173 Symbol location, 2174 Type site, 2175 Name name, 2176 boolean qualified, 2177 List<Type> argtypes, 2178 List<Type> typeargtypes, 2179 LogResolveHelper logResolveHelper) { 2180 if (sym.kind.isResolutionError()) { 2181 ResolveError errSym = (ResolveError)sym.baseSymbol(); 2182 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol); 2183 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes); 2184 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) { 2185 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes); 2186 } 2187 } 2188 return sym; 2189 } 2190 2191 /** 2192 * Variant of the generalized access routine, to be used for generating method 2193 * resolution diagnostics 2194 */ 2195 Symbol accessMethod(Symbol sym, 2196 DiagnosticPosition pos, 2197 Symbol location, 2198 Type site, 2199 Name name, 2200 boolean qualified, 2201 List<Type> argtypes, 2202 List<Type> typeargtypes) { 2203 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper); 2204 } 2205 2206 /** Same as original accessMethod(), but without location. 2207 */ 2208 Symbol accessMethod(Symbol sym, 2209 DiagnosticPosition pos, 2210 Type site, 2211 Name name, 2212 boolean qualified, 2213 List<Type> argtypes, 2214 List<Type> typeargtypes) { 2215 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes); 2216 } 2217 2218 /** 2219 * Variant of the generalized access routine, to be used for generating variable, 2220 * type resolution diagnostics 2221 */ 2222 Symbol accessBase(Symbol sym, 2223 DiagnosticPosition pos, 2224 Symbol location, 2225 Type site, 2226 Name name, 2227 boolean qualified) { 2228 return accessInternal(sym, pos, location, site, name, qualified, List.<Type>nil(), null, basicLogResolveHelper); 2229 } 2230 2231 /** Same as original accessBase(), but without location. 2232 */ 2233 Symbol accessBase(Symbol sym, 2234 DiagnosticPosition pos, 2235 Type site, 2236 Name name, 2237 boolean qualified) { 2238 return accessBase(sym, pos, site.tsym, site, name, qualified); 2239 } 2240 2241 interface LogResolveHelper { 2242 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes); 2243 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes); 2244 } 2245 2246 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() { 2247 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) { 2248 return !site.isErroneous(); 2249 } 2250 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) { 2251 return argtypes; 2252 } 2253 }; 2254 2255 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() { 2256 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) { 2257 return !site.isErroneous() && 2258 !Type.isErroneous(argtypes) && 2259 (typeargtypes == null || !Type.isErroneous(typeargtypes)); 2260 } 2261 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) { 2262 return argtypes.map(new ResolveDeferredRecoveryMap(AttrMode.SPECULATIVE, accessedSym, currentResolutionContext.step)); 2263 } 2264 }; 2265 2266 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap { 2267 2268 public ResolveDeferredRecoveryMap(AttrMode mode, Symbol msym, MethodResolutionPhase step) { 2269 deferredAttr.super(mode, msym, step); 2270 } 2271 2272 @Override 2273 protected Type typeOf(DeferredType dt) { 2274 Type res = super.typeOf(dt); 2275 if (!res.isErroneous()) { 2276 switch (TreeInfo.skipParens(dt.tree).getTag()) { 2277 case LAMBDA: 2278 case REFERENCE: 2279 return dt; 2280 case CONDEXPR: 2281 return res == Type.recoveryType ? 2282 dt : res; 2283 } 2284 } 2285 return res; 2286 } 2287 } 2288 2289 /** Check that sym is not an abstract method. 2290 */ 2291 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) { 2292 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0) 2293 log.error(pos, "abstract.cant.be.accessed.directly", 2294 kindName(sym), sym, sym.location()); 2295 } 2296 2297/* *************************************************************************** 2298 * Name resolution 2299 * Naming conventions are as for symbol lookup 2300 * Unlike the find... methods these methods will report access errors 2301 ****************************************************************************/ 2302 2303 /** Resolve an unqualified (non-method) identifier. 2304 * @param pos The position to use for error reporting. 2305 * @param env The environment current at the identifier use. 2306 * @param name The identifier's name. 2307 * @param kind The set of admissible symbol kinds for the identifier. 2308 */ 2309 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env, 2310 Name name, KindSelector kind) { 2311 return accessBase( 2312 findIdent(env, name, kind), 2313 pos, env.enclClass.sym.type, name, false); 2314 } 2315 2316 /** Resolve an unqualified method identifier. 2317 * @param pos The position to use for error reporting. 2318 * @param env The environment current at the method invocation. 2319 * @param name The identifier's name. 2320 * @param argtypes The types of the invocation's value arguments. 2321 * @param typeargtypes The types of the invocation's type arguments. 2322 */ 2323 Symbol resolveMethod(DiagnosticPosition pos, 2324 Env<AttrContext> env, 2325 Name name, 2326 List<Type> argtypes, 2327 List<Type> typeargtypes) { 2328 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck, 2329 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) { 2330 @Override 2331 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2332 return findFun(env, name, argtypes, typeargtypes, 2333 phase.isBoxingRequired(), 2334 phase.isVarargsRequired()); 2335 }}); 2336 } 2337 2338 /** Resolve a qualified method identifier 2339 * @param pos The position to use for error reporting. 2340 * @param env The environment current at the method invocation. 2341 * @param site The type of the qualifying expression, in which 2342 * identifier is searched. 2343 * @param name The identifier's name. 2344 * @param argtypes The types of the invocation's value arguments. 2345 * @param typeargtypes The types of the invocation's type arguments. 2346 */ 2347 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env, 2348 Type site, Name name, List<Type> argtypes, 2349 List<Type> typeargtypes) { 2350 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes); 2351 } 2352 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env, 2353 Symbol location, Type site, Name name, List<Type> argtypes, 2354 List<Type> typeargtypes) { 2355 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes); 2356 } 2357 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext, 2358 DiagnosticPosition pos, Env<AttrContext> env, 2359 Symbol location, Type site, Name name, List<Type> argtypes, 2360 List<Type> typeargtypes) { 2361 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) { 2362 @Override 2363 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2364 return findMethod(env, site, name, argtypes, typeargtypes, 2365 phase.isBoxingRequired(), 2366 phase.isVarargsRequired()); 2367 } 2368 @Override 2369 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 2370 if (sym.kind.isResolutionError()) { 2371 sym = super.access(env, pos, location, sym); 2372 } else if (allowMethodHandles) { 2373 MethodSymbol msym = (MethodSymbol)sym; 2374 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) { 2375 return findPolymorphicSignatureInstance(env, sym, argtypes); 2376 } 2377 } 2378 return sym; 2379 } 2380 }); 2381 } 2382 2383 /** Find or create an implicit method of exactly the given type (after erasure). 2384 * Searches in a side table, not the main scope of the site. 2385 * This emulates the lookup process required by JSR 292 in JVM. 2386 * @param env Attribution environment 2387 * @param spMethod signature polymorphic method - i.e. MH.invokeExact 2388 * @param argtypes The required argument types 2389 */ 2390 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env, 2391 final Symbol spMethod, 2392 List<Type> argtypes) { 2393 Type mtype = infer.instantiatePolymorphicSignatureInstance(env, 2394 (MethodSymbol)spMethod, currentResolutionContext, argtypes); 2395 for (Symbol sym : polymorphicSignatureScope.getSymbolsByName(spMethod.name)) { 2396 if (types.isSameType(mtype, sym.type)) { 2397 return sym; 2398 } 2399 } 2400 2401 // create the desired method 2402 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags; 2403 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) { 2404 @Override 2405 public Symbol baseSymbol() { 2406 return spMethod; 2407 } 2408 }; 2409 polymorphicSignatureScope.enter(msym); 2410 return msym; 2411 } 2412 2413 /** Resolve a qualified method identifier, throw a fatal error if not 2414 * found. 2415 * @param pos The position to use for error reporting. 2416 * @param env The environment current at the method invocation. 2417 * @param site The type of the qualifying expression, in which 2418 * identifier is searched. 2419 * @param name The identifier's name. 2420 * @param argtypes The types of the invocation's value arguments. 2421 * @param typeargtypes The types of the invocation's type arguments. 2422 */ 2423 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env, 2424 Type site, Name name, 2425 List<Type> argtypes, 2426 List<Type> typeargtypes) { 2427 MethodResolutionContext resolveContext = new MethodResolutionContext(); 2428 resolveContext.internalResolution = true; 2429 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym, 2430 site, name, argtypes, typeargtypes); 2431 if (sym.kind == MTH) return (MethodSymbol)sym; 2432 else throw new FatalError( 2433 diags.fragment("fatal.err.cant.locate.meth", 2434 name)); 2435 } 2436 2437 /** Resolve constructor. 2438 * @param pos The position to use for error reporting. 2439 * @param env The environment current at the constructor invocation. 2440 * @param site The type of class for which a constructor is searched. 2441 * @param argtypes The types of the constructor invocation's value 2442 * arguments. 2443 * @param typeargtypes The types of the constructor invocation's type 2444 * arguments. 2445 */ 2446 Symbol resolveConstructor(DiagnosticPosition pos, 2447 Env<AttrContext> env, 2448 Type site, 2449 List<Type> argtypes, 2450 List<Type> typeargtypes) { 2451 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes); 2452 } 2453 2454 private Symbol resolveConstructor(MethodResolutionContext resolveContext, 2455 final DiagnosticPosition pos, 2456 Env<AttrContext> env, 2457 Type site, 2458 List<Type> argtypes, 2459 List<Type> typeargtypes) { 2460 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) { 2461 @Override 2462 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2463 return findConstructor(pos, env, site, argtypes, typeargtypes, 2464 phase.isBoxingRequired(), 2465 phase.isVarargsRequired()); 2466 } 2467 }); 2468 } 2469 2470 /** Resolve a constructor, throw a fatal error if not found. 2471 * @param pos The position to use for error reporting. 2472 * @param env The environment current at the method invocation. 2473 * @param site The type to be constructed. 2474 * @param argtypes The types of the invocation's value arguments. 2475 * @param typeargtypes The types of the invocation's type arguments. 2476 */ 2477 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env, 2478 Type site, 2479 List<Type> argtypes, 2480 List<Type> typeargtypes) { 2481 MethodResolutionContext resolveContext = new MethodResolutionContext(); 2482 resolveContext.internalResolution = true; 2483 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes); 2484 if (sym.kind == MTH) return (MethodSymbol)sym; 2485 else throw new FatalError( 2486 diags.fragment("fatal.err.cant.locate.ctor", site)); 2487 } 2488 2489 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env, 2490 Type site, List<Type> argtypes, 2491 List<Type> typeargtypes, 2492 boolean allowBoxing, 2493 boolean useVarargs) { 2494 Symbol sym = findMethod(env, site, 2495 names.init, argtypes, 2496 typeargtypes, allowBoxing, 2497 useVarargs); 2498 chk.checkDeprecated(pos, env.info.scope.owner, sym); 2499 return sym; 2500 } 2501 2502 /** Resolve constructor using diamond inference. 2503 * @param pos The position to use for error reporting. 2504 * @param env The environment current at the constructor invocation. 2505 * @param site The type of class for which a constructor is searched. 2506 * The scope of this class has been touched in attribution. 2507 * @param argtypes The types of the constructor invocation's value 2508 * arguments. 2509 * @param typeargtypes The types of the constructor invocation's type 2510 * arguments. 2511 */ 2512 Symbol resolveDiamond(DiagnosticPosition pos, 2513 Env<AttrContext> env, 2514 Type site, 2515 List<Type> argtypes, 2516 List<Type> typeargtypes) { 2517 return lookupMethod(env, pos, site.tsym, resolveMethodCheck, 2518 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) { 2519 @Override 2520 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2521 return findDiamond(env, site, argtypes, typeargtypes, 2522 phase.isBoxingRequired(), 2523 phase.isVarargsRequired()); 2524 } 2525 @Override 2526 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 2527 if (sym.kind.isResolutionError()) { 2528 if (sym.kind != WRONG_MTH && 2529 sym.kind != WRONG_MTHS) { 2530 sym = super.access(env, pos, location, sym); 2531 } else { 2532 final JCDiagnostic details = sym.kind == WRONG_MTH ? 2533 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd : 2534 null; 2535 sym = new DiamondError(sym, currentResolutionContext); 2536 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes); 2537 env.info.pendingResolutionPhase = currentResolutionContext.step; 2538 } 2539 } 2540 return sym; 2541 }}); 2542 } 2543 2544 /** This method scans all the constructor symbol in a given class scope - 2545 * assuming that the original scope contains a constructor of the kind: 2546 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo, 2547 * a method check is executed against the modified constructor type: 2548 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond 2549 * inference. The inferred return type of the synthetic constructor IS 2550 * the inferred type for the diamond operator. 2551 */ 2552 private Symbol findDiamond(Env<AttrContext> env, 2553 Type site, 2554 List<Type> argtypes, 2555 List<Type> typeargtypes, 2556 boolean allowBoxing, 2557 boolean useVarargs) { 2558 Symbol bestSoFar = methodNotFound; 2559 TypeSymbol tsym = site.tsym.isInterface() ? syms.objectType.tsym : site.tsym; 2560 for (final Symbol sym : 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 //step 1 - bound lookup 2660 ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper( 2661 referenceTree, site, name, argtypes, typeargtypes, VARARITY); 2662 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup()); 2663 MethodResolutionContext boundSearchResolveContext = new MethodResolutionContext(); 2664 boundSearchResolveContext.methodCheck = methodCheck; 2665 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(), 2666 site.tsym, boundSearchResolveContext, boundLookupHelper); 2667 ReferenceLookupResult boundRes = new ReferenceLookupResult(boundSym, boundSearchResolveContext); 2668 2669 //step 2 - unbound lookup 2670 Symbol unboundSym = methodNotFound; 2671 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup()); 2672 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext); 2673 ReferenceLookupResult unboundRes = referenceNotFound; 2674 if (unboundLookupHelper != null) { 2675 MethodResolutionContext unboundSearchResolveContext = 2676 new MethodResolutionContext(); 2677 unboundSearchResolveContext.methodCheck = methodCheck; 2678 unboundSym = lookupMethod(unboundEnv, env.tree.pos(), 2679 site.tsym, unboundSearchResolveContext, unboundLookupHelper); 2680 unboundRes = new ReferenceLookupResult(unboundSym, unboundSearchResolveContext); 2681 } 2682 2683 //merge results 2684 Pair<Symbol, ReferenceLookupHelper> res; 2685 Symbol bestSym = referenceChooser.result(boundRes, unboundRes); 2686 res = new Pair<>(bestSym, 2687 bestSym == unboundSym ? unboundLookupHelper : boundLookupHelper); 2688 env.info.pendingResolutionPhase = bestSym == unboundSym ? 2689 unboundEnv.info.pendingResolutionPhase : 2690 boundEnv.info.pendingResolutionPhase; 2691 2692 return res; 2693 } 2694 2695 /** 2696 * This class is used to represent a method reference lookup result. It keeps track of two 2697 * things: (i) the symbol found during a method reference lookup and (ii) the static kind 2698 * of the lookup (see {@link com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind}). 2699 */ 2700 static class ReferenceLookupResult { 2701 2702 /** 2703 * Static kind associated with a method reference lookup. Erroneous lookups end up with 2704 * the UNDEFINED kind; successful lookups will end up with either STATIC, NON_STATIC, 2705 * depending on whether all applicable candidates are static or non-static methods, 2706 * respectively. If a successful lookup has both static and non-static applicable methods, 2707 * its kind is set to BOTH. 2708 */ 2709 enum StaticKind { 2710 STATIC, 2711 NON_STATIC, 2712 BOTH, 2713 UNDEFINED; 2714 2715 /** 2716 * Retrieve the static kind associated with a given (method) symbol. 2717 */ 2718 static StaticKind from(Symbol s) { 2719 return s.isStatic() ? 2720 STATIC : NON_STATIC; 2721 } 2722 2723 /** 2724 * Merge two static kinds together. 2725 */ 2726 static StaticKind reduce(StaticKind sk1, StaticKind sk2) { 2727 if (sk1 == UNDEFINED) { 2728 return sk2; 2729 } else if (sk2 == UNDEFINED) { 2730 return sk1; 2731 } else { 2732 return sk1 == sk2 ? sk1 : BOTH; 2733 } 2734 } 2735 } 2736 2737 /** The static kind. */ 2738 StaticKind staticKind; 2739 2740 /** The lookup result. */ 2741 Symbol sym; 2742 2743 ReferenceLookupResult(Symbol sym, MethodResolutionContext resolutionContext) { 2744 this.staticKind = staticKind(sym, resolutionContext); 2745 this.sym = sym; 2746 } 2747 2748 private StaticKind staticKind(Symbol sym, MethodResolutionContext resolutionContext) { 2749 switch (sym.kind) { 2750 case MTH: 2751 case AMBIGUOUS: 2752 return resolutionContext.candidates.stream() 2753 .filter(c -> c.isApplicable() && c.step == resolutionContext.step) 2754 .map(c -> StaticKind.from(c.sym)) 2755 .reduce(StaticKind::reduce) 2756 .orElse(StaticKind.UNDEFINED); 2757 case HIDDEN: 2758 return StaticKind.from(((AccessError)sym).sym); 2759 default: 2760 return StaticKind.UNDEFINED; 2761 } 2762 } 2763 2764 /** 2765 * Does this result corresponds to a successful lookup (i.e. one where a method has been found?) 2766 */ 2767 boolean isSuccess() { 2768 return staticKind != StaticKind.UNDEFINED; 2769 } 2770 2771 /** 2772 * Does this result have given static kind? 2773 */ 2774 boolean hasKind(StaticKind sk) { 2775 return this.staticKind == sk; 2776 } 2777 2778 /** 2779 * Error recovery helper: can this lookup result be ignored (for the purpose of returning 2780 * some 'better' result) ? 2781 */ 2782 boolean canIgnore() { 2783 switch (sym.kind) { 2784 case ABSENT_MTH: 2785 return true; 2786 case WRONG_MTH: 2787 InapplicableSymbolError errSym = 2788 (InapplicableSymbolError)sym.baseSymbol(); 2789 return new Template(MethodCheckDiag.ARITY_MISMATCH.regex()) 2790 .matches(errSym.errCandidate().snd); 2791 case WRONG_MTHS: 2792 InapplicableSymbolsError errSyms = 2793 (InapplicableSymbolsError)sym.baseSymbol(); 2794 return errSyms.filterCandidates(errSyms.mapCandidates()).isEmpty(); 2795 default: 2796 return false; 2797 } 2798 } 2799 } 2800 2801 /** 2802 * This abstract class embodies the logic that converts one (bound lookup) or two (unbound lookup) 2803 * {@code ReferenceLookupResult} objects into a (@code Symbol), which is then regarded as the 2804 * result of method reference resolution. 2805 */ 2806 abstract class ReferenceChooser { 2807 /** 2808 * Generate a result from a pair of lookup result objects. This method delegates to the 2809 * appropriate result generation routine. 2810 */ 2811 Symbol result(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) { 2812 return unboundRes != referenceNotFound ? 2813 unboundResult(boundRes, unboundRes) : 2814 boundResult(boundRes); 2815 } 2816 2817 /** 2818 * Generate a symbol from a given bound lookup result. 2819 */ 2820 abstract Symbol boundResult(ReferenceLookupResult boundRes); 2821 2822 /** 2823 * Generate a symbol from a pair of bound/unbound lookup results. 2824 */ 2825 abstract Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes); 2826 } 2827 2828 /** 2829 * This chooser implements the selection strategy used during a full lookup; this logic 2830 * is described in JLS SE 8 (15.3.2). 2831 */ 2832 ReferenceChooser basicReferenceChooser = new ReferenceChooser() { 2833 2834 @Override 2835 Symbol boundResult(ReferenceLookupResult boundRes) { 2836 return !boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC) ? 2837 boundRes.sym : //the search produces a non-static method 2838 new BadMethodReferenceError(boundRes.sym, false); 2839 } 2840 2841 @Override 2842 Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) { 2843 if (boundRes.hasKind(StaticKind.STATIC) && 2844 (!unboundRes.isSuccess() || unboundRes.hasKind(StaticKind.STATIC))) { 2845 //the first search produces a static method and no non-static method is applicable 2846 //during the second search 2847 return boundRes.sym; 2848 } else if (unboundRes.hasKind(StaticKind.NON_STATIC) && 2849 (!boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC))) { 2850 //the second search produces a non-static method and no static method is applicable 2851 //during the first search 2852 return unboundRes.sym; 2853 } else if (boundRes.isSuccess() && unboundRes.isSuccess()) { 2854 //both searches produce some result; ambiguity (error recovery) 2855 return ambiguityError(boundRes.sym, unboundRes.sym); 2856 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) { 2857 //Both searches failed to produce a result with correct staticness (i.e. first search 2858 //produces an non-static method). Alternatively, a given search produced a result 2859 //with the right staticness, but the other search has applicable methods with wrong 2860 //staticness (error recovery) 2861 return new BadMethodReferenceError(boundRes.isSuccess() ? boundRes.sym : unboundRes.sym, true); 2862 } else { 2863 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery) 2864 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ? 2865 unboundRes.sym : boundRes.sym; 2866 } 2867 } 2868 }; 2869 2870 /** 2871 * This chooser implements the selection strategy used during an arity-based lookup; this logic 2872 * is described in JLS SE 8 (15.12.2.1). 2873 */ 2874 ReferenceChooser structuralReferenceChooser = new ReferenceChooser() { 2875 2876 @Override 2877 Symbol boundResult(ReferenceLookupResult boundRes) { 2878 return (!boundRes.isSuccess() || !boundRes.hasKind(StaticKind.STATIC)) ? 2879 boundRes.sym : //the search has at least one applicable non-static method 2880 new BadMethodReferenceError(boundRes.sym, false); 2881 } 2882 2883 @Override 2884 Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) { 2885 if (boundRes.isSuccess() && !boundRes.hasKind(StaticKind.NON_STATIC)) { 2886 //the first serach has at least one applicable static method 2887 return boundRes.sym; 2888 } else if (unboundRes.isSuccess() && !unboundRes.hasKind(StaticKind.STATIC)) { 2889 //the second search has at least one applicable non-static method 2890 return unboundRes.sym; 2891 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) { 2892 //either the first search produces a non-static method, or second search produces 2893 //a non-static method (error recovery) 2894 return new BadMethodReferenceError(boundRes.isSuccess() ? boundRes.sym : unboundRes.sym, true); 2895 } else { 2896 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery) 2897 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ? 2898 unboundRes.sym : boundRes.sym; 2899 } 2900 } 2901 }; 2902 2903 /** 2904 * Helper for defining custom method-like lookup logic; a lookup helper 2905 * provides hooks for (i) the actual lookup logic and (ii) accessing the 2906 * lookup result (this step might result in compiler diagnostics to be generated) 2907 */ 2908 abstract class LookupHelper { 2909 2910 /** name of the symbol to lookup */ 2911 Name name; 2912 2913 /** location in which the lookup takes place */ 2914 Type site; 2915 2916 /** actual types used during the lookup */ 2917 List<Type> argtypes; 2918 2919 /** type arguments used during the lookup */ 2920 List<Type> typeargtypes; 2921 2922 /** Max overload resolution phase handled by this helper */ 2923 MethodResolutionPhase maxPhase; 2924 2925 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 2926 this.name = name; 2927 this.site = site; 2928 this.argtypes = argtypes; 2929 this.typeargtypes = typeargtypes; 2930 this.maxPhase = maxPhase; 2931 } 2932 2933 /** 2934 * Should lookup stop at given phase with given result 2935 */ 2936 final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) { 2937 return phase.ordinal() > maxPhase.ordinal() || 2938 !sym.kind.isResolutionError() || sym.kind == AMBIGUOUS; 2939 } 2940 2941 /** 2942 * Search for a symbol under a given overload resolution phase - this method 2943 * is usually called several times, once per each overload resolution phase 2944 */ 2945 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase); 2946 2947 /** 2948 * Dump overload resolution info 2949 */ 2950 void debug(DiagnosticPosition pos, Symbol sym) { 2951 //do nothing 2952 } 2953 2954 /** 2955 * Validate the result of the lookup 2956 */ 2957 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym); 2958 } 2959 2960 abstract class BasicLookupHelper extends LookupHelper { 2961 2962 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) { 2963 this(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY); 2964 } 2965 2966 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 2967 super(name, site, argtypes, typeargtypes, maxPhase); 2968 } 2969 2970 @Override 2971 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2972 Symbol sym = doLookup(env, phase); 2973 if (sym.kind == AMBIGUOUS) { 2974 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol(); 2975 sym = a_err.mergeAbstracts(site); 2976 } 2977 return sym; 2978 } 2979 2980 abstract Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase); 2981 2982 @Override 2983 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 2984 if (sym.kind.isResolutionError()) { 2985 //if nothing is found return the 'first' error 2986 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes); 2987 } 2988 return sym; 2989 } 2990 2991 @Override 2992 void debug(DiagnosticPosition pos, Symbol sym) { 2993 reportVerboseResolutionDiagnostic(pos, name, site, argtypes, typeargtypes, sym); 2994 } 2995 } 2996 2997 /** 2998 * Helper class for member reference lookup. A reference lookup helper 2999 * defines the basic logic for member reference lookup; a method gives 3000 * access to an 'unbound' helper used to perform an unbound member 3001 * reference lookup. 3002 */ 3003 abstract class ReferenceLookupHelper extends LookupHelper { 3004 3005 /** The member reference tree */ 3006 JCMemberReference referenceTree; 3007 3008 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site, 3009 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3010 super(name, site, argtypes, typeargtypes, maxPhase); 3011 this.referenceTree = referenceTree; 3012 } 3013 3014 /** 3015 * Returns an unbound version of this lookup helper. By default, this 3016 * method returns an dummy lookup helper. 3017 */ 3018 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3019 return null; 3020 } 3021 3022 /** 3023 * Get the kind of the member reference 3024 */ 3025 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym); 3026 3027 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 3028 if (sym.kind == AMBIGUOUS) { 3029 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol(); 3030 sym = a_err.mergeAbstracts(site); 3031 } 3032 //skip error reporting 3033 return sym; 3034 } 3035 } 3036 3037 /** 3038 * Helper class for method reference lookup. The lookup logic is based 3039 * upon Resolve.findMethod; in certain cases, this helper class has a 3040 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper). 3041 * In such cases, non-static lookup results are thrown away. 3042 */ 3043 class MethodReferenceLookupHelper extends ReferenceLookupHelper { 3044 3045 /** The original method reference lookup site. */ 3046 Type originalSite; 3047 3048 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site, 3049 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3050 super(referenceTree, name, types.skipTypeVars(site, true), argtypes, typeargtypes, maxPhase); 3051 this.originalSite = site; 3052 } 3053 3054 @Override 3055 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3056 return findMethod(env, site, name, argtypes, typeargtypes, 3057 phase.isBoxingRequired(), phase.isVarargsRequired()); 3058 } 3059 3060 @Override 3061 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3062 if (TreeInfo.isStaticSelector(referenceTree.expr, names)) { 3063 if (argtypes.nonEmpty() && 3064 (argtypes.head.hasTag(NONE) || 3065 types.isSubtypeUnchecked(inferenceContext.asUndetVar(argtypes.head), site))) { 3066 return new UnboundMethodReferenceLookupHelper(referenceTree, name, 3067 originalSite, argtypes, typeargtypes, maxPhase); 3068 } else { 3069 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) { 3070 @Override 3071 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3072 return this; 3073 } 3074 3075 @Override 3076 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3077 return methodNotFound; 3078 } 3079 3080 @Override 3081 ReferenceKind referenceKind(Symbol sym) { 3082 Assert.error(); 3083 return null; 3084 } 3085 }; 3086 } 3087 } else { 3088 return super.unboundLookup(inferenceContext); 3089 } 3090 } 3091 3092 @Override 3093 ReferenceKind referenceKind(Symbol sym) { 3094 if (sym.isStatic()) { 3095 return ReferenceKind.STATIC; 3096 } else { 3097 Name selName = TreeInfo.name(referenceTree.getQualifierExpression()); 3098 return selName != null && selName == names._super ? 3099 ReferenceKind.SUPER : 3100 ReferenceKind.BOUND; 3101 } 3102 } 3103 } 3104 3105 /** 3106 * Helper class for unbound method reference lookup. Essentially the same 3107 * as the basic method reference lookup helper; main difference is that static 3108 * lookup results are thrown away. If qualifier type is raw, an attempt to 3109 * infer a parameterized type is made using the first actual argument (that 3110 * would otherwise be ignored during the lookup). 3111 */ 3112 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper { 3113 3114 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site, 3115 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3116 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase); 3117 if (site.isRaw() && !argtypes.head.hasTag(NONE)) { 3118 Type asSuperSite = types.asSuper(argtypes.head, site.tsym); 3119 this.site = types.skipTypeVars(asSuperSite, true); 3120 } 3121 } 3122 3123 @Override 3124 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3125 return this; 3126 } 3127 3128 @Override 3129 ReferenceKind referenceKind(Symbol sym) { 3130 return ReferenceKind.UNBOUND; 3131 } 3132 } 3133 3134 /** 3135 * Helper class for array constructor lookup; an array constructor lookup 3136 * is simulated by looking up a method that returns the array type specified 3137 * as qualifier, and that accepts a single int parameter (size of the array). 3138 */ 3139 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper { 3140 3141 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes, 3142 List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3143 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase); 3144 } 3145 3146 @Override 3147 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3148 WriteableScope sc = WriteableScope.create(syms.arrayClass); 3149 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym); 3150 arrayConstr.type = new MethodType(List.<Type>of(syms.intType), site, List.<Type>nil(), syms.methodClass); 3151 sc.enter(arrayConstr); 3152 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false); 3153 } 3154 3155 @Override 3156 ReferenceKind referenceKind(Symbol sym) { 3157 return ReferenceKind.ARRAY_CTOR; 3158 } 3159 } 3160 3161 /** 3162 * Helper class for constructor reference lookup. The lookup logic is based 3163 * upon either Resolve.findMethod or Resolve.findDiamond - depending on 3164 * whether the constructor reference needs diamond inference (this is the case 3165 * if the qualifier type is raw). A special erroneous symbol is returned 3166 * if the lookup returns the constructor of an inner class and there's no 3167 * enclosing instance in scope. 3168 */ 3169 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper { 3170 3171 boolean needsInference; 3172 3173 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes, 3174 List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3175 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase); 3176 if (site.isRaw()) { 3177 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym, site.getMetadata()); 3178 needsInference = true; 3179 } 3180 } 3181 3182 @Override 3183 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3184 Symbol sym = needsInference ? 3185 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) : 3186 findMethod(env, site, name, argtypes, typeargtypes, 3187 phase.isBoxingRequired(), phase.isVarargsRequired()); 3188 return site.getEnclosingType().hasTag(CLASS) && !hasEnclosingInstance(env, site) ? 3189 new BadConstructorReferenceError(sym) : 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.isResolutionError(); 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.isResolutionError() && 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.isResolutionError() ? 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.isResolutionError() && bestSoFar.kind != AMBIGUOUS); 4236 if (!sym.kind.isResolutionError()) { 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