Resolve.java revision 3182:bdbad16dd9ac
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) { 293 294 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor 295 to refer to an inaccessible type 296 */ 297 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0) 298 return true; 299 300 boolean isAccessible = false; 301 switch ((short)(c.flags() & AccessFlags)) { 302 case PRIVATE: 303 isAccessible = 304 env.enclClass.sym.outermostClass() == 305 c.owner.outermostClass(); 306 break; 307 case 0: 308 isAccessible = 309 env.toplevel.packge == c.owner // fast special case 310 || 311 env.toplevel.packge == c.packge(); 312 break; 313 default: // error recovery 314 case PUBLIC: 315 isAccessible = true; 316 break; 317 case PROTECTED: 318 isAccessible = 319 env.toplevel.packge == c.owner // fast special case 320 || 321 env.toplevel.packge == c.packge() 322 || 323 isInnerSubClass(env.enclClass.sym, c.owner); 324 break; 325 } 326 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ? 327 isAccessible : 328 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner); 329 } 330 //where 331 /** Is given class a subclass of given base class, or an inner class 332 * of a subclass? 333 * Return null if no such class exists. 334 * @param c The class which is the subclass or is contained in it. 335 * @param base The base class 336 */ 337 private boolean isInnerSubClass(ClassSymbol c, Symbol base) { 338 while (c != null && !c.isSubClass(base, types)) { 339 c = c.owner.enclClass(); 340 } 341 return c != null; 342 } 343 344 boolean isAccessible(Env<AttrContext> env, Type t) { 345 return isAccessible(env, t, false); 346 } 347 348 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) { 349 return (t.hasTag(ARRAY)) 350 ? isAccessible(env, types.cvarUpperBound(types.elemtype(t))) 351 : isAccessible(env, t.tsym, checkInner); 352 } 353 354 /** Is symbol accessible as a member of given type in given environment? 355 * @param env The current environment. 356 * @param site The type of which the tested symbol is regarded 357 * as a member. 358 * @param sym The symbol. 359 */ 360 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) { 361 return isAccessible(env, site, sym, false); 362 } 363 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) { 364 if (sym.name == names.init && sym.owner != site.tsym) return false; 365 366 /* 15.9.5.1: Note that it is possible for the signature of the anonymous constructor 367 to refer to an inaccessible type 368 */ 369 if (env.enclMethod != null && (env.enclMethod.mods.flags & ANONCONSTR) != 0) 370 return true; 371 372 switch ((short)(sym.flags() & AccessFlags)) { 373 case PRIVATE: 374 return 375 (env.enclClass.sym == sym.owner // fast special case 376 || 377 env.enclClass.sym.outermostClass() == 378 sym.owner.outermostClass()) 379 && 380 sym.isInheritedIn(site.tsym, types); 381 case 0: 382 return 383 (env.toplevel.packge == sym.owner.owner // fast special case 384 || 385 env.toplevel.packge == sym.packge()) 386 && 387 isAccessible(env, site, checkInner) 388 && 389 sym.isInheritedIn(site.tsym, types) 390 && 391 notOverriddenIn(site, sym); 392 case PROTECTED: 393 return 394 (env.toplevel.packge == sym.owner.owner // fast special case 395 || 396 env.toplevel.packge == sym.packge() 397 || 398 isProtectedAccessible(sym, env.enclClass.sym, site) 399 || 400 // OK to select instance method or field from 'super' or type name 401 // (but type names should be disallowed elsewhere!) 402 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP) 403 && 404 isAccessible(env, site, checkInner) 405 && 406 notOverriddenIn(site, sym); 407 default: // this case includes erroneous combinations as well 408 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym); 409 } 410 } 411 //where 412 /* `sym' is accessible only if not overridden by 413 * another symbol which is a member of `site' 414 * (because, if it is overridden, `sym' is not strictly 415 * speaking a member of `site'). A polymorphic signature method 416 * cannot be overridden (e.g. MH.invokeExact(Object[])). 417 */ 418 private boolean notOverriddenIn(Type site, Symbol sym) { 419 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic()) 420 return true; 421 else { 422 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true); 423 return (s2 == null || s2 == sym || sym.owner == s2.owner || 424 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym))); 425 } 426 } 427 //where 428 /** Is given protected symbol accessible if it is selected from given site 429 * and the selection takes place in given class? 430 * @param sym The symbol with protected access 431 * @param c The class where the access takes place 432 * @site The type of the qualifier 433 */ 434 private 435 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) { 436 Type newSite = site.hasTag(TYPEVAR) ? site.getUpperBound() : site; 437 while (c != null && 438 !(c.isSubClass(sym.owner, types) && 439 (c.flags() & INTERFACE) == 0 && 440 // In JLS 2e 6.6.2.1, the subclass restriction applies 441 // only to instance fields and methods -- types are excluded 442 // regardless of whether they are declared 'static' or not. 443 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || newSite.tsym.isSubClass(c, types)))) 444 c = c.owner.enclClass(); 445 return c != null; 446 } 447 448 /** 449 * Performs a recursive scan of a type looking for accessibility problems 450 * from current attribution environment 451 */ 452 void checkAccessibleType(Env<AttrContext> env, Type t) { 453 accessibilityChecker.visit(t, env); 454 } 455 456 /** 457 * Accessibility type-visitor 458 */ 459 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker = 460 new Types.SimpleVisitor<Void, Env<AttrContext>>() { 461 462 void visit(List<Type> ts, Env<AttrContext> env) { 463 for (Type t : ts) { 464 visit(t, env); 465 } 466 } 467 468 public Void visitType(Type t, Env<AttrContext> env) { 469 return null; 470 } 471 472 @Override 473 public Void visitArrayType(ArrayType t, Env<AttrContext> env) { 474 visit(t.elemtype, env); 475 return null; 476 } 477 478 @Override 479 public Void visitClassType(ClassType t, Env<AttrContext> env) { 480 visit(t.getTypeArguments(), env); 481 if (!isAccessible(env, t, true)) { 482 accessBase(new AccessError(t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true); 483 } 484 return null; 485 } 486 487 @Override 488 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) { 489 visit(t.type, env); 490 return null; 491 } 492 493 @Override 494 public Void visitMethodType(MethodType t, Env<AttrContext> env) { 495 visit(t.getParameterTypes(), env); 496 visit(t.getReturnType(), env); 497 visit(t.getThrownTypes(), env); 498 return null; 499 } 500 }; 501 502 /** Try to instantiate the type of a method so that it fits 503 * given type arguments and argument types. If successful, return 504 * the method's instantiated type, else return null. 505 * The instantiation will take into account an additional leading 506 * formal parameter if the method is an instance method seen as a member 507 * of an under determined site. In this case, we treat site as an additional 508 * parameter and the parameters of the class containing the method as 509 * additional type variables that get instantiated. 510 * 511 * @param env The current environment 512 * @param site The type of which the method is a member. 513 * @param m The method symbol. 514 * @param argtypes The invocation's given value arguments. 515 * @param typeargtypes The invocation's given type arguments. 516 * @param allowBoxing Allow boxing conversions of arguments. 517 * @param useVarargs Box trailing arguments into an array for varargs. 518 */ 519 Type rawInstantiate(Env<AttrContext> env, 520 Type site, 521 Symbol m, 522 ResultInfo resultInfo, 523 List<Type> argtypes, 524 List<Type> typeargtypes, 525 boolean allowBoxing, 526 boolean useVarargs, 527 Warner warn) throws Infer.InferenceException { 528 Type mt = types.memberType(site, m); 529 // tvars is the list of formal type variables for which type arguments 530 // need to inferred. 531 List<Type> tvars = List.nil(); 532 if (typeargtypes == null) typeargtypes = List.nil(); 533 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) { 534 // This is not a polymorphic method, but typeargs are supplied 535 // which is fine, see JLS 15.12.2.1 536 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) { 537 ForAll pmt = (ForAll) mt; 538 if (typeargtypes.length() != pmt.tvars.length()) 539 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args 540 // Check type arguments are within bounds 541 List<Type> formals = pmt.tvars; 542 List<Type> actuals = typeargtypes; 543 while (formals.nonEmpty() && actuals.nonEmpty()) { 544 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head), 545 pmt.tvars, typeargtypes); 546 for (; bounds.nonEmpty(); bounds = bounds.tail) { 547 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn)) 548 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds); 549 } 550 formals = formals.tail; 551 actuals = actuals.tail; 552 } 553 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes); 554 } else if (mt.hasTag(FORALL)) { 555 ForAll pmt = (ForAll) mt; 556 List<Type> tvars1 = types.newInstances(pmt.tvars); 557 tvars = tvars.appendList(tvars1); 558 mt = types.subst(pmt.qtype, pmt.tvars, tvars1); 559 } 560 561 // find out whether we need to go the slow route via infer 562 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/ 563 for (List<Type> l = argtypes; 564 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded; 565 l = l.tail) { 566 if (l.head.hasTag(FORALL)) instNeeded = true; 567 } 568 569 if (instNeeded) { 570 return infer.instantiateMethod(env, 571 tvars, 572 (MethodType)mt, 573 resultInfo, 574 (MethodSymbol)m, 575 argtypes, 576 allowBoxing, 577 useVarargs, 578 currentResolutionContext, 579 warn); 580 } 581 582 DeferredAttr.DeferredAttrContext dc = currentResolutionContext.deferredAttrContext(m, infer.emptyContext, resultInfo, warn); 583 currentResolutionContext.methodCheck.argumentsAcceptable(env, dc, 584 argtypes, mt.getParameterTypes(), warn); 585 dc.complete(); 586 return mt; 587 } 588 589 Type checkMethod(Env<AttrContext> env, 590 Type site, 591 Symbol m, 592 ResultInfo resultInfo, 593 List<Type> argtypes, 594 List<Type> typeargtypes, 595 Warner warn) { 596 MethodResolutionContext prevContext = currentResolutionContext; 597 try { 598 currentResolutionContext = new MethodResolutionContext(); 599 currentResolutionContext.attrMode = (resultInfo.pt == Infer.anyPoly) ? 600 AttrMode.SPECULATIVE : DeferredAttr.AttrMode.CHECK; 601 if (env.tree.hasTag(JCTree.Tag.REFERENCE)) { 602 //method/constructor references need special check class 603 //to handle inference variables in 'argtypes' (might happen 604 //during an unsticking round) 605 currentResolutionContext.methodCheck = 606 new MethodReferenceCheck(resultInfo.checkContext.inferenceContext()); 607 } 608 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase; 609 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes, 610 step.isBoxingRequired(), step.isVarargsRequired(), warn); 611 } 612 finally { 613 currentResolutionContext = prevContext; 614 } 615 } 616 617 /** Same but returns null instead throwing a NoInstanceException 618 */ 619 Type instantiate(Env<AttrContext> env, 620 Type site, 621 Symbol m, 622 ResultInfo resultInfo, 623 List<Type> argtypes, 624 List<Type> typeargtypes, 625 boolean allowBoxing, 626 boolean useVarargs, 627 Warner warn) { 628 try { 629 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes, 630 allowBoxing, useVarargs, warn); 631 } catch (InapplicableMethodException ex) { 632 return null; 633 } 634 } 635 636 /** 637 * This interface defines an entry point that should be used to perform a 638 * method check. A method check usually consist in determining as to whether 639 * a set of types (actuals) is compatible with another set of types (formals). 640 * Since the notion of compatibility can vary depending on the circumstances, 641 * this interfaces allows to easily add new pluggable method check routines. 642 */ 643 interface MethodCheck { 644 /** 645 * Main method check routine. A method check usually consist in determining 646 * as to whether a set of types (actuals) is compatible with another set of 647 * types (formals). If an incompatibility is found, an unchecked exception 648 * is assumed to be thrown. 649 */ 650 void argumentsAcceptable(Env<AttrContext> env, 651 DeferredAttrContext deferredAttrContext, 652 List<Type> argtypes, 653 List<Type> formals, 654 Warner warn); 655 656 /** 657 * Retrieve the method check object that will be used during a 658 * most specific check. 659 */ 660 MethodCheck mostSpecificCheck(List<Type> actuals); 661 } 662 663 /** 664 * Helper enum defining all method check diagnostics (used by resolveMethodCheck). 665 */ 666 enum MethodCheckDiag { 667 /** 668 * Actuals and formals differs in length. 669 */ 670 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"), 671 /** 672 * An actual is incompatible with a formal. 673 */ 674 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"), 675 /** 676 * An actual is incompatible with the varargs element type. 677 */ 678 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"), 679 /** 680 * The varargs element type is inaccessible. 681 */ 682 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type"); 683 684 final String basicKey; 685 final String inferKey; 686 687 MethodCheckDiag(String basicKey, String inferKey) { 688 this.basicKey = basicKey; 689 this.inferKey = inferKey; 690 } 691 692 String regex() { 693 return String.format("([a-z]*\\.)*(%s|%s)", basicKey, inferKey); 694 } 695 } 696 697 /** 698 * Dummy method check object. All methods are deemed applicable, regardless 699 * of their formal parameter types. 700 */ 701 MethodCheck nilMethodCheck = new MethodCheck() { 702 public void argumentsAcceptable(Env<AttrContext> env, DeferredAttrContext deferredAttrContext, List<Type> argtypes, List<Type> formals, Warner warn) { 703 //do nothing - method always applicable regardless of actuals 704 } 705 706 public MethodCheck mostSpecificCheck(List<Type> actuals) { 707 return this; 708 } 709 }; 710 711 /** 712 * Base class for 'real' method checks. The class defines the logic for 713 * iterating through formals and actuals and provides and entry point 714 * that can be used by subclasses in order to define the actual check logic. 715 */ 716 abstract class AbstractMethodCheck implements MethodCheck { 717 @Override 718 public void argumentsAcceptable(final Env<AttrContext> env, 719 DeferredAttrContext deferredAttrContext, 720 List<Type> argtypes, 721 List<Type> formals, 722 Warner warn) { 723 //should we expand formals? 724 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired(); 725 JCTree callTree = treeForDiagnostics(env); 726 List<JCExpression> trees = TreeInfo.args(callTree); 727 728 //inference context used during this method check 729 InferenceContext inferenceContext = deferredAttrContext.inferenceContext; 730 731 Type varargsFormal = useVarargs ? formals.last() : null; 732 733 if (varargsFormal == null && 734 argtypes.size() != formals.size()) { 735 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args 736 } 737 738 while (argtypes.nonEmpty() && formals.head != varargsFormal) { 739 DiagnosticPosition pos = trees != null ? trees.head : null; 740 checkArg(pos, false, argtypes.head, formals.head, deferredAttrContext, warn); 741 argtypes = argtypes.tail; 742 formals = formals.tail; 743 trees = trees != null ? trees.tail : trees; 744 } 745 746 if (formals.head != varargsFormal) { 747 reportMC(callTree, MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args 748 } 749 750 if (useVarargs) { 751 //note: if applicability check is triggered by most specific test, 752 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5) 753 final Type elt = types.elemtype(varargsFormal); 754 while (argtypes.nonEmpty()) { 755 DiagnosticPosition pos = trees != null ? trees.head : null; 756 checkArg(pos, true, argtypes.head, elt, deferredAttrContext, warn); 757 argtypes = argtypes.tail; 758 trees = trees != null ? trees.tail : trees; 759 } 760 } 761 } 762 763 // where 764 private JCTree treeForDiagnostics(Env<AttrContext> env) { 765 return env.info.preferredTreeForDiagnostics != null ? env.info.preferredTreeForDiagnostics : env.tree; 766 } 767 768 /** 769 * Does the actual argument conforms to the corresponding formal? 770 */ 771 abstract void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn); 772 773 protected void reportMC(DiagnosticPosition pos, MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) { 774 boolean inferDiag = inferenceContext != infer.emptyContext; 775 InapplicableMethodException ex = inferDiag ? 776 infer.inferenceException : inapplicableMethodException; 777 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) { 778 Object[] args2 = new Object[args.length + 1]; 779 System.arraycopy(args, 0, args2, 1, args.length); 780 args2[0] = inferenceContext.inferenceVars(); 781 args = args2; 782 } 783 String key = inferDiag ? diag.inferKey : diag.basicKey; 784 throw ex.setMessage(diags.create(DiagnosticType.FRAGMENT, log.currentSource(), pos, key, args)); 785 } 786 787 public MethodCheck mostSpecificCheck(List<Type> actuals) { 788 return nilMethodCheck; 789 } 790 791 } 792 793 /** 794 * Arity-based method check. A method is applicable if the number of actuals 795 * supplied conforms to the method signature. 796 */ 797 MethodCheck arityMethodCheck = new AbstractMethodCheck() { 798 @Override 799 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) { 800 //do nothing - actual always compatible to formals 801 } 802 803 @Override 804 public String toString() { 805 return "arityMethodCheck"; 806 } 807 }; 808 809 List<Type> dummyArgs(int length) { 810 ListBuffer<Type> buf = new ListBuffer<>(); 811 for (int i = 0 ; i < length ; i++) { 812 buf.append(Type.noType); 813 } 814 return buf.toList(); 815 } 816 817 /** 818 * Main method applicability routine. Given a list of actual types A, 819 * a list of formal types F, determines whether the types in A are 820 * compatible (by method invocation conversion) with the types in F. 821 * 822 * Since this routine is shared between overload resolution and method 823 * type-inference, a (possibly empty) inference context is used to convert 824 * formal types to the corresponding 'undet' form ahead of a compatibility 825 * check so that constraints can be propagated and collected. 826 * 827 * Moreover, if one or more types in A is a deferred type, this routine uses 828 * DeferredAttr in order to perform deferred attribution. If one or more actual 829 * deferred types are stuck, they are placed in a queue and revisited later 830 * after the remainder of the arguments have been seen. If this is not sufficient 831 * to 'unstuck' the argument, a cyclic inference error is called out. 832 * 833 * A method check handler (see above) is used in order to report errors. 834 */ 835 MethodCheck resolveMethodCheck = new AbstractMethodCheck() { 836 837 @Override 838 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) { 839 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn); 840 mresult.check(pos, actual); 841 } 842 843 @Override 844 public void argumentsAcceptable(final Env<AttrContext> env, 845 DeferredAttrContext deferredAttrContext, 846 List<Type> argtypes, 847 List<Type> formals, 848 Warner warn) { 849 super.argumentsAcceptable(env, deferredAttrContext, argtypes, formals, warn); 850 // should we check varargs element type accessibility? 851 if (deferredAttrContext.phase.isVarargsRequired()) { 852 if (deferredAttrContext.mode == AttrMode.CHECK || !checkVarargsAccessAfterResolution) { 853 varargsAccessible(env, types.elemtype(formals.last()), deferredAttrContext.inferenceContext); 854 } 855 } 856 } 857 858 /** 859 * Test that the runtime array element type corresponding to 't' is accessible. 't' should be the 860 * varargs element type of either the method invocation type signature (after inference completes) 861 * or the method declaration signature (before inference completes). 862 */ 863 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) { 864 if (inferenceContext.free(t)) { 865 inferenceContext.addFreeTypeListener(List.of(t), new FreeTypeListener() { 866 @Override 867 public void typesInferred(InferenceContext inferenceContext) { 868 varargsAccessible(env, inferenceContext.asInstType(t), inferenceContext); 869 } 870 }); 871 } else { 872 if (!isAccessible(env, types.erasure(t))) { 873 Symbol location = env.enclClass.sym; 874 reportMC(env.tree, MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location); 875 } 876 } 877 } 878 879 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to, 880 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) { 881 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) { 882 MethodCheckDiag methodDiag = varargsCheck ? 883 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH; 884 885 @Override 886 public void report(DiagnosticPosition pos, JCDiagnostic details) { 887 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details); 888 } 889 }; 890 return new MethodResultInfo(to, checkContext); 891 } 892 893 @Override 894 public MethodCheck mostSpecificCheck(List<Type> actuals) { 895 return new MostSpecificCheck(actuals); 896 } 897 898 @Override 899 public String toString() { 900 return "resolveMethodCheck"; 901 } 902 }; 903 904 /** 905 * This class handles method reference applicability checks; since during 906 * these checks it's sometime possible to have inference variables on 907 * the actual argument types list, the method applicability check must be 908 * extended so that inference variables are 'opened' as needed. 909 */ 910 class MethodReferenceCheck extends AbstractMethodCheck { 911 912 InferenceContext pendingInferenceContext; 913 914 MethodReferenceCheck(InferenceContext pendingInferenceContext) { 915 this.pendingInferenceContext = pendingInferenceContext; 916 } 917 918 @Override 919 void checkArg(DiagnosticPosition pos, boolean varargs, Type actual, Type formal, DeferredAttrContext deferredAttrContext, Warner warn) { 920 ResultInfo mresult = methodCheckResult(varargs, formal, deferredAttrContext, warn); 921 mresult.check(pos, actual); 922 } 923 924 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to, 925 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) { 926 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) { 927 MethodCheckDiag methodDiag = varargsCheck ? 928 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH; 929 930 @Override 931 public boolean compatible(Type found, Type req, Warner warn) { 932 found = pendingInferenceContext.asUndetVar(found); 933 if (found.hasTag(UNDETVAR) && req.isPrimitive()) { 934 req = types.boxedClass(req).type; 935 } 936 return super.compatible(found, req, warn); 937 } 938 939 @Override 940 public void report(DiagnosticPosition pos, JCDiagnostic details) { 941 reportMC(pos, methodDiag, deferredAttrContext.inferenceContext, details); 942 } 943 }; 944 return new MethodResultInfo(to, checkContext); 945 } 946 947 @Override 948 public MethodCheck mostSpecificCheck(List<Type> actuals) { 949 return new MostSpecificCheck(actuals); 950 } 951 952 @Override 953 public String toString() { 954 return "MethodReferenceCheck"; 955 } 956 } 957 958 /** 959 * Check context to be used during method applicability checks. A method check 960 * context might contain inference variables. 961 */ 962 abstract class MethodCheckContext implements CheckContext { 963 964 boolean strict; 965 DeferredAttrContext deferredAttrContext; 966 Warner rsWarner; 967 968 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) { 969 this.strict = strict; 970 this.deferredAttrContext = deferredAttrContext; 971 this.rsWarner = rsWarner; 972 } 973 974 public boolean compatible(Type found, Type req, Warner warn) { 975 InferenceContext inferenceContext = deferredAttrContext.inferenceContext; 976 return strict ? 977 types.isSubtypeUnchecked(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn) : 978 types.isConvertible(inferenceContext.asUndetVar(found), inferenceContext.asUndetVar(req), warn); 979 } 980 981 public void report(DiagnosticPosition pos, JCDiagnostic details) { 982 throw inapplicableMethodException.setMessage(details); 983 } 984 985 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) { 986 return rsWarner; 987 } 988 989 public InferenceContext inferenceContext() { 990 return deferredAttrContext.inferenceContext; 991 } 992 993 public DeferredAttrContext deferredAttrContext() { 994 return deferredAttrContext; 995 } 996 997 @Override 998 public String toString() { 999 return "MethodCheckContext"; 1000 } 1001 } 1002 1003 /** 1004 * ResultInfo class to be used during method applicability checks. Check 1005 * for deferred types goes through special path. 1006 */ 1007 class MethodResultInfo extends ResultInfo { 1008 1009 public MethodResultInfo(Type pt, CheckContext checkContext) { 1010 attr.super(KindSelector.VAL, pt, checkContext); 1011 } 1012 1013 @Override 1014 protected Type check(DiagnosticPosition pos, Type found) { 1015 if (found.hasTag(DEFERRED)) { 1016 DeferredType dt = (DeferredType)found; 1017 return dt.check(this); 1018 } else { 1019 Type uResult = U(found); 1020 Type capturedType = pos == null || pos.getTree() == null ? 1021 types.capture(uResult) : 1022 checkContext.inferenceContext() 1023 .cachedCapture(pos.getTree(), uResult, true); 1024 return super.check(pos, chk.checkNonVoid(pos, capturedType)); 1025 } 1026 } 1027 1028 /** 1029 * javac has a long-standing 'simplification' (see 6391995): 1030 * given an actual argument type, the method check is performed 1031 * on its upper bound. This leads to inconsistencies when an 1032 * argument type is checked against itself. For example, given 1033 * a type-variable T, it is not true that {@code U(T) <: T}, 1034 * so we need to guard against that. 1035 */ 1036 private Type U(Type found) { 1037 return found == pt ? 1038 found : types.cvarUpperBound(found); 1039 } 1040 1041 @Override 1042 protected MethodResultInfo dup(Type newPt) { 1043 return new MethodResultInfo(newPt, checkContext); 1044 } 1045 1046 @Override 1047 protected ResultInfo dup(CheckContext newContext) { 1048 return new MethodResultInfo(pt, newContext); 1049 } 1050 1051 @Override 1052 protected ResultInfo dup(Type newPt, CheckContext newContext) { 1053 return new MethodResultInfo(newPt, newContext); 1054 } 1055 } 1056 1057 /** 1058 * Most specific method applicability routine. Given a list of actual types A, 1059 * a list of formal types F1, and a list of formal types F2, the routine determines 1060 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t. 1061 * argument types A. 1062 */ 1063 class MostSpecificCheck implements MethodCheck { 1064 1065 List<Type> actuals; 1066 1067 MostSpecificCheck(List<Type> actuals) { 1068 this.actuals = actuals; 1069 } 1070 1071 @Override 1072 public void argumentsAcceptable(final Env<AttrContext> env, 1073 DeferredAttrContext deferredAttrContext, 1074 List<Type> formals1, 1075 List<Type> formals2, 1076 Warner warn) { 1077 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired()); 1078 while (formals2.nonEmpty()) { 1079 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head); 1080 mresult.check(null, formals1.head); 1081 formals1 = formals1.tail; 1082 formals2 = formals2.tail; 1083 actuals = actuals.isEmpty() ? actuals : actuals.tail; 1084 } 1085 } 1086 1087 /** 1088 * Create a method check context to be used during the most specific applicability check 1089 */ 1090 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext, 1091 Warner rsWarner, Type actual) { 1092 return attr.new ResultInfo(KindSelector.VAL, to, 1093 new MostSpecificCheckContext(deferredAttrContext, rsWarner, actual)); 1094 } 1095 1096 /** 1097 * Subclass of method check context class that implements most specific 1098 * method conversion. If the actual type under analysis is a deferred type 1099 * a full blown structural analysis is carried out. 1100 */ 1101 class MostSpecificCheckContext extends MethodCheckContext { 1102 1103 Type actual; 1104 1105 public MostSpecificCheckContext(DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) { 1106 super(true, deferredAttrContext, rsWarner); 1107 this.actual = actual; 1108 } 1109 1110 public boolean compatible(Type found, Type req, Warner warn) { 1111 if (allowFunctionalInterfaceMostSpecific && 1112 unrelatedFunctionalInterfaces(found, req) && 1113 (actual != null && actual.getTag() == DEFERRED)) { 1114 DeferredType dt = (DeferredType) actual; 1115 JCTree speculativeTree = dt.speculativeTree(deferredAttrContext); 1116 if (speculativeTree != deferredAttr.stuckTree) { 1117 return functionalInterfaceMostSpecific(found, req, speculativeTree); 1118 } 1119 } 1120 return compatibleBySubtyping(found, req); 1121 } 1122 1123 private boolean compatibleBySubtyping(Type found, Type req) { 1124 if (!strict && found.isPrimitive() != req.isPrimitive()) { 1125 found = found.isPrimitive() ? types.boxedClass(found).type : types.unboxedType(found); 1126 } 1127 return types.isSubtypeNoCapture(found, deferredAttrContext.inferenceContext.asUndetVar(req)); 1128 } 1129 1130 /** Whether {@code t} and {@code s} are unrelated functional interface types. */ 1131 private boolean unrelatedFunctionalInterfaces(Type t, Type s) { 1132 return types.isFunctionalInterface(t.tsym) && 1133 types.isFunctionalInterface(s.tsym) && 1134 types.asSuper(t, s.tsym) == null && 1135 types.asSuper(s, t.tsym) == null; 1136 } 1137 1138 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */ 1139 private boolean functionalInterfaceMostSpecific(Type t, Type s, JCTree tree) { 1140 FunctionalInterfaceMostSpecificChecker msc = new FunctionalInterfaceMostSpecificChecker(t, s); 1141 msc.scan(tree); 1142 return msc.result; 1143 } 1144 1145 /** 1146 * Tests whether one functional interface type can be considered more specific 1147 * than another unrelated functional interface type for the scanned expression. 1148 */ 1149 class FunctionalInterfaceMostSpecificChecker extends DeferredAttr.PolyScanner { 1150 1151 final Type t; 1152 final Type s; 1153 boolean result; 1154 1155 /** Parameters {@code t} and {@code s} are unrelated functional interface types. */ 1156 FunctionalInterfaceMostSpecificChecker(Type t, Type s) { 1157 this.t = t; 1158 this.s = s; 1159 result = true; 1160 } 1161 1162 @Override 1163 void skip(JCTree tree) { 1164 result &= false; 1165 } 1166 1167 @Override 1168 public void visitConditional(JCConditional tree) { 1169 scan(asExpr(tree.truepart)); 1170 scan(asExpr(tree.falsepart)); 1171 } 1172 1173 @Override 1174 public void visitReference(JCMemberReference tree) { 1175 Type desc_t = types.findDescriptorType(t); 1176 Type desc_s = types.findDescriptorType(s); 1177 // use inference variables here for more-specific inference (18.5.4) 1178 if (!types.isSameTypes(desc_t.getParameterTypes(), 1179 inferenceContext().asUndetVars(desc_s.getParameterTypes()))) { 1180 result &= false; 1181 } else { 1182 // compare return types 1183 Type ret_t = desc_t.getReturnType(); 1184 Type ret_s = desc_s.getReturnType(); 1185 if (ret_s.hasTag(VOID)) { 1186 result &= true; 1187 } else if (ret_t.hasTag(VOID)) { 1188 result &= false; 1189 } else if (ret_t.isPrimitive() != ret_s.isPrimitive()) { 1190 boolean retValIsPrimitive = 1191 tree.refPolyKind == PolyKind.STANDALONE && 1192 tree.sym.type.getReturnType().isPrimitive(); 1193 result &= (retValIsPrimitive == ret_t.isPrimitive()) && 1194 (retValIsPrimitive != ret_s.isPrimitive()); 1195 } else { 1196 result &= compatibleBySubtyping(ret_t, ret_s); 1197 } 1198 } 1199 } 1200 1201 @Override 1202 public void visitParens(JCParens tree) { 1203 scan(asExpr(tree.expr)); 1204 } 1205 1206 @Override 1207 public void visitLambda(JCLambda tree) { 1208 Type desc_t = types.findDescriptorType(t); 1209 Type desc_s = types.findDescriptorType(s); 1210 // use inference variables here for more-specific inference (18.5.4) 1211 if (!types.isSameTypes(desc_t.getParameterTypes(), 1212 inferenceContext().asUndetVars(desc_s.getParameterTypes()))) { 1213 result &= false; 1214 } else { 1215 // compare return types 1216 Type ret_t = desc_t.getReturnType(); 1217 Type ret_s = desc_s.getReturnType(); 1218 if (ret_s.hasTag(VOID)) { 1219 result &= true; 1220 } else if (ret_t.hasTag(VOID)) { 1221 result &= false; 1222 } else if (unrelatedFunctionalInterfaces(ret_t, ret_s)) { 1223 for (JCExpression expr : lambdaResults(tree)) { 1224 result &= functionalInterfaceMostSpecific(ret_t, ret_s, expr); 1225 } 1226 } else if (ret_t.isPrimitive() != ret_s.isPrimitive()) { 1227 for (JCExpression expr : lambdaResults(tree)) { 1228 boolean retValIsPrimitive = expr.isStandalone() && expr.type.isPrimitive(); 1229 result &= (retValIsPrimitive == ret_t.isPrimitive()) && 1230 (retValIsPrimitive != ret_s.isPrimitive()); 1231 } 1232 } else { 1233 result &= compatibleBySubtyping(ret_t, ret_s); 1234 } 1235 } 1236 } 1237 //where 1238 1239 private List<JCExpression> lambdaResults(JCLambda lambda) { 1240 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) { 1241 return List.of(asExpr((JCExpression) lambda.body)); 1242 } else { 1243 final ListBuffer<JCExpression> buffer = new ListBuffer<>(); 1244 DeferredAttr.LambdaReturnScanner lambdaScanner = 1245 new DeferredAttr.LambdaReturnScanner() { 1246 @Override 1247 public void visitReturn(JCReturn tree) { 1248 if (tree.expr != null) { 1249 buffer.append(asExpr(tree.expr)); 1250 } 1251 } 1252 }; 1253 lambdaScanner.scan(lambda.body); 1254 return buffer.toList(); 1255 } 1256 } 1257 1258 private JCExpression asExpr(JCExpression expr) { 1259 if (expr.type.hasTag(DEFERRED)) { 1260 JCTree speculativeTree = ((DeferredType)expr.type).speculativeTree(deferredAttrContext); 1261 if (speculativeTree != deferredAttr.stuckTree) { 1262 expr = (JCExpression)speculativeTree; 1263 } 1264 } 1265 return expr; 1266 } 1267 } 1268 1269 } 1270 1271 public MethodCheck mostSpecificCheck(List<Type> actuals) { 1272 Assert.error("Cannot get here!"); 1273 return null; 1274 } 1275 } 1276 1277 public static class InapplicableMethodException extends RuntimeException { 1278 private static final long serialVersionUID = 0; 1279 1280 JCDiagnostic diagnostic; 1281 JCDiagnostic.Factory diags; 1282 1283 InapplicableMethodException(JCDiagnostic.Factory diags) { 1284 this.diagnostic = null; 1285 this.diags = diags; 1286 } 1287 InapplicableMethodException setMessage() { 1288 return setMessage((JCDiagnostic)null); 1289 } 1290 InapplicableMethodException setMessage(String key) { 1291 return setMessage(key != null ? diags.fragment(key) : null); 1292 } 1293 InapplicableMethodException setMessage(String key, Object... args) { 1294 return setMessage(key != null ? diags.fragment(key, args) : null); 1295 } 1296 InapplicableMethodException setMessage(JCDiagnostic diag) { 1297 this.diagnostic = diag; 1298 return this; 1299 } 1300 1301 public JCDiagnostic getDiagnostic() { 1302 return diagnostic; 1303 } 1304 } 1305 private final InapplicableMethodException inapplicableMethodException; 1306 1307/* *************************************************************************** 1308 * Symbol lookup 1309 * the following naming conventions for arguments are used 1310 * 1311 * env is the environment where the symbol was mentioned 1312 * site is the type of which the symbol is a member 1313 * name is the symbol's name 1314 * if no arguments are given 1315 * argtypes are the value arguments, if we search for a method 1316 * 1317 * If no symbol was found, a ResolveError detailing the problem is returned. 1318 ****************************************************************************/ 1319 1320 /** Find field. Synthetic fields are always skipped. 1321 * @param env The current environment. 1322 * @param site The original type from where the selection takes place. 1323 * @param name The name of the field. 1324 * @param c The class to search for the field. This is always 1325 * a superclass or implemented interface of site's class. 1326 */ 1327 Symbol findField(Env<AttrContext> env, 1328 Type site, 1329 Name name, 1330 TypeSymbol c) { 1331 while (c.type.hasTag(TYPEVAR)) 1332 c = c.type.getUpperBound().tsym; 1333 Symbol bestSoFar = varNotFound; 1334 Symbol sym; 1335 for (Symbol s : c.members().getSymbolsByName(name)) { 1336 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) { 1337 return isAccessible(env, site, s) 1338 ? s : new AccessError(env, site, s); 1339 } 1340 } 1341 Type st = types.supertype(c.type); 1342 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) { 1343 sym = findField(env, site, name, st.tsym); 1344 bestSoFar = bestOf(bestSoFar, sym); 1345 } 1346 for (List<Type> l = types.interfaces(c.type); 1347 bestSoFar.kind != AMBIGUOUS && l.nonEmpty(); 1348 l = l.tail) { 1349 sym = findField(env, site, name, l.head.tsym); 1350 if (bestSoFar.exists() && sym.exists() && 1351 sym.owner != bestSoFar.owner) 1352 bestSoFar = new AmbiguityError(bestSoFar, sym); 1353 else 1354 bestSoFar = bestOf(bestSoFar, sym); 1355 } 1356 return bestSoFar; 1357 } 1358 1359 /** Resolve a field identifier, throw a fatal error if not found. 1360 * @param pos The position to use for error reporting. 1361 * @param env The environment current at the method invocation. 1362 * @param site The type of the qualifying expression, in which 1363 * identifier is searched. 1364 * @param name The identifier's name. 1365 */ 1366 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env, 1367 Type site, Name name) { 1368 Symbol sym = findField(env, site, name, site.tsym); 1369 if (sym.kind == VAR) return (VarSymbol)sym; 1370 else throw new FatalError( 1371 diags.fragment("fatal.err.cant.locate.field", 1372 name)); 1373 } 1374 1375 /** Find unqualified variable or field with given name. 1376 * Synthetic fields always skipped. 1377 * @param env The current environment. 1378 * @param name The name of the variable or field. 1379 */ 1380 Symbol findVar(Env<AttrContext> env, Name name) { 1381 Symbol bestSoFar = varNotFound; 1382 Env<AttrContext> env1 = env; 1383 boolean staticOnly = false; 1384 while (env1.outer != null) { 1385 Symbol sym = null; 1386 if (isStatic(env1)) staticOnly = true; 1387 for (Symbol s : env1.info.scope.getSymbolsByName(name)) { 1388 if (s.kind == VAR && (s.flags_field & SYNTHETIC) == 0) { 1389 sym = s; 1390 break; 1391 } 1392 } 1393 if (sym == null) { 1394 sym = findField(env1, env1.enclClass.sym.type, name, env1.enclClass.sym); 1395 } 1396 if (sym.exists()) { 1397 if (staticOnly && 1398 sym.kind == VAR && 1399 sym.owner.kind == TYP && 1400 (sym.flags() & STATIC) == 0) 1401 return new StaticError(sym); 1402 else 1403 return sym; 1404 } else { 1405 bestSoFar = bestOf(bestSoFar, sym); 1406 } 1407 1408 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true; 1409 env1 = env1.outer; 1410 } 1411 1412 Symbol sym = findField(env, syms.predefClass.type, name, syms.predefClass); 1413 if (sym.exists()) 1414 return sym; 1415 if (bestSoFar.exists()) 1416 return bestSoFar; 1417 1418 Symbol origin = null; 1419 for (Scope sc : new Scope[] { env.toplevel.namedImportScope, env.toplevel.starImportScope }) { 1420 for (Symbol currentSymbol : sc.getSymbolsByName(name)) { 1421 if (currentSymbol.kind != VAR) 1422 continue; 1423 // invariant: sym.kind == Symbol.Kind.VAR 1424 if (!bestSoFar.kind.isResolutionError() && 1425 currentSymbol.owner != bestSoFar.owner) 1426 return new AmbiguityError(bestSoFar, currentSymbol); 1427 else if (!bestSoFar.kind.betterThan(VAR)) { 1428 origin = sc.getOrigin(currentSymbol).owner; 1429 bestSoFar = isAccessible(env, origin.type, currentSymbol) 1430 ? currentSymbol : new AccessError(env, origin.type, currentSymbol); 1431 } 1432 } 1433 if (bestSoFar.exists()) break; 1434 } 1435 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type) 1436 return bestSoFar.clone(origin); 1437 else 1438 return bestSoFar; 1439 } 1440 1441 Warner noteWarner = new Warner(); 1442 1443 /** Select the best method for a call site among two choices. 1444 * @param env The current environment. 1445 * @param site The original type from where the 1446 * selection takes place. 1447 * @param argtypes The invocation's value arguments, 1448 * @param typeargtypes The invocation's type arguments, 1449 * @param sym Proposed new best match. 1450 * @param bestSoFar Previously found best match. 1451 * @param allowBoxing Allow boxing conversions of arguments. 1452 * @param useVarargs Box trailing arguments into an array for varargs. 1453 */ 1454 @SuppressWarnings("fallthrough") 1455 Symbol selectBest(Env<AttrContext> env, 1456 Type site, 1457 List<Type> argtypes, 1458 List<Type> typeargtypes, 1459 Symbol sym, 1460 Symbol bestSoFar, 1461 boolean allowBoxing, 1462 boolean useVarargs) { 1463 if (sym.kind == ERR || 1464 !sym.isInheritedIn(site.tsym, types)) { 1465 return bestSoFar; 1466 } else if (useVarargs && (sym.flags() & VARARGS) == 0) { 1467 return bestSoFar.kind.isResolutionError() ? 1468 new BadVarargsMethod((ResolveError)bestSoFar.baseSymbol()) : 1469 bestSoFar; 1470 } 1471 Assert.check(!sym.kind.isResolutionError()); 1472 try { 1473 types.noWarnings.clear(); 1474 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes, 1475 allowBoxing, useVarargs, types.noWarnings); 1476 currentResolutionContext.addApplicableCandidate(sym, mt); 1477 } catch (InapplicableMethodException ex) { 1478 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic()); 1479 switch (bestSoFar.kind) { 1480 case ABSENT_MTH: 1481 return new InapplicableSymbolError(currentResolutionContext); 1482 case WRONG_MTH: 1483 bestSoFar = new InapplicableSymbolsError(currentResolutionContext); 1484 default: 1485 return bestSoFar; 1486 } 1487 } 1488 if (!isAccessible(env, site, sym)) { 1489 return (bestSoFar.kind == ABSENT_MTH) 1490 ? new AccessError(env, site, sym) 1491 : bestSoFar; 1492 } 1493 return (bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS) 1494 ? sym 1495 : mostSpecific(argtypes, sym, bestSoFar, env, site, useVarargs); 1496 } 1497 1498 /* Return the most specific of the two methods for a call, 1499 * given that both are accessible and applicable. 1500 * @param m1 A new candidate for most specific. 1501 * @param m2 The previous most specific candidate. 1502 * @param env The current environment. 1503 * @param site The original type from where the selection 1504 * takes place. 1505 * @param allowBoxing Allow boxing conversions of arguments. 1506 * @param useVarargs Box trailing arguments into an array for varargs. 1507 */ 1508 Symbol mostSpecific(List<Type> argtypes, Symbol m1, 1509 Symbol m2, 1510 Env<AttrContext> env, 1511 final Type site, 1512 boolean useVarargs) { 1513 switch (m2.kind) { 1514 case MTH: 1515 if (m1 == m2) return m1; 1516 boolean m1SignatureMoreSpecific = 1517 signatureMoreSpecific(argtypes, env, site, m1, m2, useVarargs); 1518 boolean m2SignatureMoreSpecific = 1519 signatureMoreSpecific(argtypes, env, site, m2, m1, useVarargs); 1520 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) { 1521 Type mt1 = types.memberType(site, m1); 1522 Type mt2 = types.memberType(site, m2); 1523 if (!types.overrideEquivalent(mt1, mt2)) 1524 return ambiguityError(m1, m2); 1525 1526 // same signature; select (a) the non-bridge method, or 1527 // (b) the one that overrides the other, or (c) the concrete 1528 // one, or (d) merge both abstract signatures 1529 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE)) 1530 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1; 1531 1532 // if one overrides or hides the other, use it 1533 TypeSymbol m1Owner = (TypeSymbol)m1.owner; 1534 TypeSymbol m2Owner = (TypeSymbol)m2.owner; 1535 if (types.asSuper(m1Owner.type, m2Owner) != null && 1536 ((m1.owner.flags_field & INTERFACE) == 0 || 1537 (m2.owner.flags_field & INTERFACE) != 0) && 1538 m1.overrides(m2, m1Owner, types, false)) 1539 return m1; 1540 if (types.asSuper(m2Owner.type, m1Owner) != null && 1541 ((m2.owner.flags_field & INTERFACE) == 0 || 1542 (m1.owner.flags_field & INTERFACE) != 0) && 1543 m2.overrides(m1, m2Owner, types, false)) 1544 return m2; 1545 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0; 1546 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0; 1547 if (m1Abstract && !m2Abstract) return m2; 1548 if (m2Abstract && !m1Abstract) return m1; 1549 // both abstract or both concrete 1550 return ambiguityError(m1, m2); 1551 } 1552 if (m1SignatureMoreSpecific) return m1; 1553 if (m2SignatureMoreSpecific) return m2; 1554 return ambiguityError(m1, m2); 1555 case AMBIGUOUS: 1556 //compare m1 to ambiguous methods in m2 1557 AmbiguityError e = (AmbiguityError)m2.baseSymbol(); 1558 boolean m1MoreSpecificThanAnyAmbiguous = true; 1559 boolean allAmbiguousMoreSpecificThanM1 = true; 1560 for (Symbol s : e.ambiguousSyms) { 1561 Symbol moreSpecific = mostSpecific(argtypes, m1, s, env, site, useVarargs); 1562 m1MoreSpecificThanAnyAmbiguous &= moreSpecific == m1; 1563 allAmbiguousMoreSpecificThanM1 &= moreSpecific == s; 1564 } 1565 if (m1MoreSpecificThanAnyAmbiguous) 1566 return m1; 1567 //if m1 is more specific than some ambiguous methods, but other ambiguous methods are 1568 //more specific than m1, add it as a new ambiguous method: 1569 if (!allAmbiguousMoreSpecificThanM1) 1570 e.addAmbiguousSymbol(m1); 1571 return e; 1572 default: 1573 throw new AssertionError(); 1574 } 1575 } 1576 //where 1577 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean useVarargs) { 1578 noteWarner.clear(); 1579 int maxLength = Math.max( 1580 Math.max(m1.type.getParameterTypes().length(), actuals.length()), 1581 m2.type.getParameterTypes().length()); 1582 MethodResolutionContext prevResolutionContext = currentResolutionContext; 1583 try { 1584 currentResolutionContext = new MethodResolutionContext(); 1585 currentResolutionContext.step = prevResolutionContext.step; 1586 currentResolutionContext.methodCheck = 1587 prevResolutionContext.methodCheck.mostSpecificCheck(actuals); 1588 Type mst = instantiate(env, site, m2, null, 1589 adjustArgs(types.cvarLowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null, 1590 false, useVarargs, noteWarner); 1591 return mst != null && 1592 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED); 1593 } finally { 1594 currentResolutionContext = prevResolutionContext; 1595 } 1596 } 1597 1598 List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) { 1599 if ((msym.flags() & VARARGS) != 0 && allowVarargs) { 1600 Type varargsElem = types.elemtype(args.last()); 1601 if (varargsElem == null) { 1602 Assert.error("Bad varargs = " + args.last() + " " + msym); 1603 } 1604 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse(); 1605 while (newArgs.length() < length) { 1606 newArgs = newArgs.append(newArgs.last()); 1607 } 1608 return newArgs; 1609 } else { 1610 return args; 1611 } 1612 } 1613 //where 1614 Type mostSpecificReturnType(Type mt1, Type mt2) { 1615 Type rt1 = mt1.getReturnType(); 1616 Type rt2 = mt2.getReturnType(); 1617 1618 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL)) { 1619 //if both are generic methods, adjust return type ahead of subtyping check 1620 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments()); 1621 } 1622 //first use subtyping, then return type substitutability 1623 if (types.isSubtype(rt1, rt2)) { 1624 return mt1; 1625 } else if (types.isSubtype(rt2, rt1)) { 1626 return mt2; 1627 } else if (types.returnTypeSubstitutable(mt1, mt2)) { 1628 return mt1; 1629 } else if (types.returnTypeSubstitutable(mt2, mt1)) { 1630 return mt2; 1631 } else { 1632 return null; 1633 } 1634 } 1635 //where 1636 Symbol ambiguityError(Symbol m1, Symbol m2) { 1637 if (((m1.flags() | m2.flags()) & CLASH) != 0) { 1638 return (m1.flags() & CLASH) == 0 ? m1 : m2; 1639 } else { 1640 return new AmbiguityError(m1, m2); 1641 } 1642 } 1643 1644 Symbol findMethodInScope(Env<AttrContext> env, 1645 Type site, 1646 Name name, 1647 List<Type> argtypes, 1648 List<Type> typeargtypes, 1649 Scope sc, 1650 Symbol bestSoFar, 1651 boolean allowBoxing, 1652 boolean useVarargs, 1653 boolean abstractok) { 1654 for (Symbol s : sc.getSymbolsByName(name, new LookupFilter(abstractok))) { 1655 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s, 1656 bestSoFar, allowBoxing, useVarargs); 1657 } 1658 return bestSoFar; 1659 } 1660 //where 1661 class LookupFilter implements Filter<Symbol> { 1662 1663 boolean abstractOk; 1664 1665 LookupFilter(boolean abstractOk) { 1666 this.abstractOk = abstractOk; 1667 } 1668 1669 public boolean accepts(Symbol s) { 1670 long flags = s.flags(); 1671 return s.kind == MTH && 1672 (flags & SYNTHETIC) == 0 && 1673 (abstractOk || 1674 (flags & DEFAULT) != 0 || 1675 (flags & ABSTRACT) == 0); 1676 } 1677 } 1678 1679 /** Find best qualified method matching given name, type and value 1680 * arguments. 1681 * @param env The current environment. 1682 * @param site The original type from where the selection 1683 * takes place. 1684 * @param name The method's name. 1685 * @param argtypes The method's value arguments. 1686 * @param typeargtypes The method's type arguments 1687 * @param allowBoxing Allow boxing conversions of arguments. 1688 * @param useVarargs Box trailing arguments into an array for varargs. 1689 */ 1690 Symbol findMethod(Env<AttrContext> env, 1691 Type site, 1692 Name name, 1693 List<Type> argtypes, 1694 List<Type> typeargtypes, 1695 boolean allowBoxing, 1696 boolean useVarargs) { 1697 Symbol bestSoFar = methodNotFound; 1698 bestSoFar = findMethod(env, 1699 site, 1700 name, 1701 argtypes, 1702 typeargtypes, 1703 site.tsym.type, 1704 bestSoFar, 1705 allowBoxing, 1706 useVarargs); 1707 return bestSoFar; 1708 } 1709 // where 1710 private Symbol findMethod(Env<AttrContext> env, 1711 Type site, 1712 Name name, 1713 List<Type> argtypes, 1714 List<Type> typeargtypes, 1715 Type intype, 1716 Symbol bestSoFar, 1717 boolean allowBoxing, 1718 boolean useVarargs) { 1719 @SuppressWarnings({"unchecked","rawtypes"}) 1720 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() }; 1721 1722 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK; 1723 for (TypeSymbol s : superclasses(intype)) { 1724 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes, 1725 s.members(), bestSoFar, allowBoxing, useVarargs, true); 1726 if (name == names.init) return bestSoFar; 1727 iphase = (iphase == null) ? null : iphase.update(s, this); 1728 if (iphase != null) { 1729 for (Type itype : types.interfaces(s.type)) { 1730 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]); 1731 } 1732 } 1733 } 1734 1735 Symbol concrete = bestSoFar.kind.isValid() && 1736 (bestSoFar.flags() & ABSTRACT) == 0 ? 1737 bestSoFar : methodNotFound; 1738 1739 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) { 1740 //keep searching for abstract methods 1741 for (Type itype : itypes[iphase2.ordinal()]) { 1742 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure()) 1743 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK && 1744 (itype.tsym.flags() & DEFAULT) == 0) continue; 1745 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes, 1746 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, true); 1747 if (concrete != bestSoFar && 1748 concrete.kind.isValid() && 1749 bestSoFar.kind.isValid() && 1750 types.isSubSignature(concrete.type, bestSoFar.type)) { 1751 //this is an hack - as javac does not do full membership checks 1752 //most specific ends up comparing abstract methods that might have 1753 //been implemented by some concrete method in a subclass and, 1754 //because of raw override, it is possible for an abstract method 1755 //to be more specific than the concrete method - so we need 1756 //to explicitly call that out (see CR 6178365) 1757 bestSoFar = concrete; 1758 } 1759 } 1760 } 1761 return bestSoFar; 1762 } 1763 1764 enum InterfaceLookupPhase { 1765 ABSTRACT_OK() { 1766 @Override 1767 InterfaceLookupPhase update(Symbol s, Resolve rs) { 1768 //We should not look for abstract methods if receiver is a concrete class 1769 //(as concrete classes are expected to implement all abstracts coming 1770 //from superinterfaces) 1771 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) { 1772 return this; 1773 } else { 1774 return DEFAULT_OK; 1775 } 1776 } 1777 }, 1778 DEFAULT_OK() { 1779 @Override 1780 InterfaceLookupPhase update(Symbol s, Resolve rs) { 1781 return this; 1782 } 1783 }; 1784 1785 abstract InterfaceLookupPhase update(Symbol s, Resolve rs); 1786 } 1787 1788 /** 1789 * Return an Iterable object to scan the superclasses of a given type. 1790 * It's crucial that the scan is done lazily, as we don't want to accidentally 1791 * access more supertypes than strictly needed (as this could trigger completion 1792 * errors if some of the not-needed supertypes are missing/ill-formed). 1793 */ 1794 Iterable<TypeSymbol> superclasses(final Type intype) { 1795 return new Iterable<TypeSymbol>() { 1796 public Iterator<TypeSymbol> iterator() { 1797 return new Iterator<TypeSymbol>() { 1798 1799 List<TypeSymbol> seen = List.nil(); 1800 TypeSymbol currentSym = symbolFor(intype); 1801 TypeSymbol prevSym = null; 1802 1803 public boolean hasNext() { 1804 if (currentSym == syms.noSymbol) { 1805 currentSym = symbolFor(types.supertype(prevSym.type)); 1806 } 1807 return currentSym != null; 1808 } 1809 1810 public TypeSymbol next() { 1811 prevSym = currentSym; 1812 currentSym = syms.noSymbol; 1813 Assert.check(prevSym != null || prevSym != syms.noSymbol); 1814 return prevSym; 1815 } 1816 1817 public void remove() { 1818 throw new UnsupportedOperationException(); 1819 } 1820 1821 TypeSymbol symbolFor(Type t) { 1822 if (!t.hasTag(CLASS) && 1823 !t.hasTag(TYPEVAR)) { 1824 return null; 1825 } 1826 t = types.skipTypeVars(t, false); 1827 if (seen.contains(t.tsym)) { 1828 //degenerate case in which we have a circular 1829 //class hierarchy - because of ill-formed classfiles 1830 return null; 1831 } 1832 seen = seen.prepend(t.tsym); 1833 return t.tsym; 1834 } 1835 }; 1836 } 1837 }; 1838 } 1839 1840 /** Find unqualified method matching given name, type and value arguments. 1841 * @param env The current environment. 1842 * @param name The method's name. 1843 * @param argtypes The method's value arguments. 1844 * @param typeargtypes The method's type arguments. 1845 * @param allowBoxing Allow boxing conversions of arguments. 1846 * @param useVarargs Box trailing arguments into an array for varargs. 1847 */ 1848 Symbol findFun(Env<AttrContext> env, Name name, 1849 List<Type> argtypes, List<Type> typeargtypes, 1850 boolean allowBoxing, boolean useVarargs) { 1851 Symbol bestSoFar = methodNotFound; 1852 Env<AttrContext> env1 = env; 1853 boolean staticOnly = false; 1854 while (env1.outer != null) { 1855 if (isStatic(env1)) staticOnly = true; 1856 Assert.check(env1.info.preferredTreeForDiagnostics == null); 1857 env1.info.preferredTreeForDiagnostics = env.tree; 1858 try { 1859 Symbol sym = findMethod( 1860 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes, 1861 allowBoxing, useVarargs); 1862 if (sym.exists()) { 1863 if (staticOnly && 1864 sym.kind == MTH && 1865 sym.owner.kind == TYP && 1866 (sym.flags() & STATIC) == 0) return new StaticError(sym); 1867 else return sym; 1868 } else { 1869 bestSoFar = bestOf(bestSoFar, sym); 1870 } 1871 } finally { 1872 env1.info.preferredTreeForDiagnostics = null; 1873 } 1874 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true; 1875 env1 = env1.outer; 1876 } 1877 1878 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes, 1879 typeargtypes, allowBoxing, useVarargs); 1880 if (sym.exists()) 1881 return sym; 1882 1883 for (Symbol currentSym : env.toplevel.namedImportScope.getSymbolsByName(name)) { 1884 Symbol origin = env.toplevel.namedImportScope.getOrigin(currentSym).owner; 1885 if (currentSym.kind == MTH) { 1886 if (currentSym.owner.type != origin.type) 1887 currentSym = currentSym.clone(origin); 1888 if (!isAccessible(env, origin.type, currentSym)) 1889 currentSym = new AccessError(env, origin.type, currentSym); 1890 bestSoFar = selectBest(env, origin.type, 1891 argtypes, typeargtypes, 1892 currentSym, bestSoFar, 1893 allowBoxing, useVarargs); 1894 } 1895 } 1896 if (bestSoFar.exists()) 1897 return bestSoFar; 1898 1899 for (Symbol currentSym : env.toplevel.starImportScope.getSymbolsByName(name)) { 1900 Symbol origin = env.toplevel.starImportScope.getOrigin(currentSym).owner; 1901 if (currentSym.kind == MTH) { 1902 if (currentSym.owner.type != origin.type) 1903 currentSym = currentSym.clone(origin); 1904 if (!isAccessible(env, origin.type, currentSym)) 1905 currentSym = new AccessError(env, origin.type, currentSym); 1906 bestSoFar = selectBest(env, origin.type, 1907 argtypes, typeargtypes, 1908 currentSym, bestSoFar, 1909 allowBoxing, useVarargs); 1910 } 1911 } 1912 return bestSoFar; 1913 } 1914 1915 /** Load toplevel or member class with given fully qualified name and 1916 * verify that it is accessible. 1917 * @param env The current environment. 1918 * @param name The fully qualified name of the class to be loaded. 1919 */ 1920 Symbol loadClass(Env<AttrContext> env, Name name) { 1921 try { 1922 ClassSymbol c = finder.loadClass(name); 1923 return isAccessible(env, c) ? c : new AccessError(c); 1924 } catch (ClassFinder.BadClassFile err) { 1925 throw err; 1926 } catch (CompletionFailure ex) { 1927 return typeNotFound; 1928 } 1929 } 1930 1931 1932 /** 1933 * Find a type declared in a scope (not inherited). Return null 1934 * if none is found. 1935 * @param env The current environment. 1936 * @param site The original type from where the selection takes 1937 * place. 1938 * @param name The type's name. 1939 * @param c The class to search for the member type. This is 1940 * always a superclass or implemented interface of 1941 * site's class. 1942 */ 1943 Symbol findImmediateMemberType(Env<AttrContext> env, 1944 Type site, 1945 Name name, 1946 TypeSymbol c) { 1947 for (Symbol sym : c.members().getSymbolsByName(name)) { 1948 if (sym.kind == TYP) { 1949 return isAccessible(env, site, sym) 1950 ? sym 1951 : new AccessError(env, site, sym); 1952 } 1953 } 1954 return typeNotFound; 1955 } 1956 1957 /** Find a member type inherited from a superclass or interface. 1958 * @param env The current environment. 1959 * @param site The original type from where the selection takes 1960 * place. 1961 * @param name The type's name. 1962 * @param c The class to search for the member type. This is 1963 * always a superclass or implemented interface of 1964 * site's class. 1965 */ 1966 Symbol findInheritedMemberType(Env<AttrContext> env, 1967 Type site, 1968 Name name, 1969 TypeSymbol c) { 1970 Symbol bestSoFar = typeNotFound; 1971 Symbol sym; 1972 Type st = types.supertype(c.type); 1973 if (st != null && st.hasTag(CLASS)) { 1974 sym = findMemberType(env, site, name, st.tsym); 1975 bestSoFar = bestOf(bestSoFar, sym); 1976 } 1977 for (List<Type> l = types.interfaces(c.type); 1978 bestSoFar.kind != AMBIGUOUS && l.nonEmpty(); 1979 l = l.tail) { 1980 sym = findMemberType(env, site, name, l.head.tsym); 1981 if (!bestSoFar.kind.isResolutionError() && 1982 !sym.kind.isResolutionError() && 1983 sym.owner != bestSoFar.owner) 1984 bestSoFar = new AmbiguityError(bestSoFar, sym); 1985 else 1986 bestSoFar = bestOf(bestSoFar, sym); 1987 } 1988 return bestSoFar; 1989 } 1990 1991 /** Find qualified member type. 1992 * @param env The current environment. 1993 * @param site The original type from where the selection takes 1994 * place. 1995 * @param name The type's name. 1996 * @param c The class to search for the member type. This is 1997 * always a superclass or implemented interface of 1998 * site's class. 1999 */ 2000 Symbol findMemberType(Env<AttrContext> env, 2001 Type site, 2002 Name name, 2003 TypeSymbol c) { 2004 Symbol sym = findImmediateMemberType(env, site, name, c); 2005 2006 if (sym != typeNotFound) 2007 return sym; 2008 2009 return findInheritedMemberType(env, site, name, c); 2010 2011 } 2012 2013 /** Find a global type in given scope and load corresponding class. 2014 * @param env The current environment. 2015 * @param scope The scope in which to look for the type. 2016 * @param name The type's name. 2017 */ 2018 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) { 2019 Symbol bestSoFar = typeNotFound; 2020 for (Symbol s : scope.getSymbolsByName(name)) { 2021 Symbol sym = loadClass(env, s.flatName()); 2022 if (bestSoFar.kind == TYP && sym.kind == TYP && 2023 bestSoFar != sym) 2024 return new AmbiguityError(bestSoFar, sym); 2025 else 2026 bestSoFar = bestOf(bestSoFar, sym); 2027 } 2028 return bestSoFar; 2029 } 2030 2031 Symbol findTypeVar(Env<AttrContext> env, Name name, boolean staticOnly) { 2032 for (Symbol sym : env.info.scope.getSymbolsByName(name)) { 2033 if (sym.kind == TYP) { 2034 if (staticOnly && 2035 sym.type.hasTag(TYPEVAR) && 2036 sym.owner.kind == TYP) 2037 return new StaticError(sym); 2038 return sym; 2039 } 2040 } 2041 return typeNotFound; 2042 } 2043 2044 /** Find an unqualified type symbol. 2045 * @param env The current environment. 2046 * @param name The type's name. 2047 */ 2048 Symbol findType(Env<AttrContext> env, Name name) { 2049 if (name == names.empty) 2050 return typeNotFound; // do not allow inadvertent "lookup" of anonymous types 2051 Symbol bestSoFar = typeNotFound; 2052 Symbol sym; 2053 boolean staticOnly = false; 2054 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) { 2055 if (isStatic(env1)) staticOnly = true; 2056 // First, look for a type variable and the first member type 2057 final Symbol tyvar = findTypeVar(env1, name, staticOnly); 2058 sym = findImmediateMemberType(env1, env1.enclClass.sym.type, 2059 name, env1.enclClass.sym); 2060 2061 // Return the type variable if we have it, and have no 2062 // immediate member, OR the type variable is for a method. 2063 if (tyvar != typeNotFound) { 2064 if (env.baseClause || sym == typeNotFound || 2065 (tyvar.kind == TYP && tyvar.exists() && 2066 tyvar.owner.kind == MTH)) { 2067 return tyvar; 2068 } 2069 } 2070 2071 // If the environment is a class def, finish up, 2072 // otherwise, do the entire findMemberType 2073 if (sym == typeNotFound) 2074 sym = findInheritedMemberType(env1, env1.enclClass.sym.type, 2075 name, env1.enclClass.sym); 2076 2077 if (staticOnly && sym.kind == TYP && 2078 sym.type.hasTag(CLASS) && 2079 sym.type.getEnclosingType().hasTag(CLASS) && 2080 env1.enclClass.sym.type.isParameterized() && 2081 sym.type.getEnclosingType().isParameterized()) 2082 return new StaticError(sym); 2083 else if (sym.exists()) return sym; 2084 else bestSoFar = bestOf(bestSoFar, sym); 2085 2086 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass; 2087 if ((encl.sym.flags() & STATIC) != 0) 2088 staticOnly = true; 2089 } 2090 2091 if (!env.tree.hasTag(IMPORT)) { 2092 sym = findGlobalType(env, env.toplevel.namedImportScope, name); 2093 if (sym.exists()) return sym; 2094 else bestSoFar = bestOf(bestSoFar, sym); 2095 2096 sym = findGlobalType(env, env.toplevel.packge.members(), name); 2097 if (sym.exists()) return sym; 2098 else bestSoFar = bestOf(bestSoFar, sym); 2099 2100 sym = findGlobalType(env, env.toplevel.starImportScope, name); 2101 if (sym.exists()) return sym; 2102 else bestSoFar = bestOf(bestSoFar, sym); 2103 } 2104 2105 return bestSoFar; 2106 } 2107 2108 /** Find an unqualified identifier which matches a specified kind set. 2109 * @param env The current environment. 2110 * @param name The identifier's name. 2111 * @param kind Indicates the possible symbol kinds 2112 * (a subset of VAL, TYP, PCK). 2113 */ 2114 Symbol findIdent(Env<AttrContext> env, Name name, KindSelector kind) { 2115 Symbol bestSoFar = typeNotFound; 2116 Symbol sym; 2117 2118 if (kind.contains(KindSelector.VAL)) { 2119 sym = findVar(env, name); 2120 if (sym.exists()) return sym; 2121 else bestSoFar = bestOf(bestSoFar, sym); 2122 } 2123 2124 if (kind.contains(KindSelector.TYP)) { 2125 sym = findType(env, name); 2126 2127 if (sym.exists()) return sym; 2128 else bestSoFar = bestOf(bestSoFar, sym); 2129 } 2130 2131 if (kind.contains(KindSelector.PCK)) 2132 return syms.enterPackage(name); 2133 else return bestSoFar; 2134 } 2135 2136 /** Find an identifier in a package which matches a specified kind set. 2137 * @param env The current environment. 2138 * @param name The identifier's name. 2139 * @param kind Indicates the possible symbol kinds 2140 * (a nonempty subset of TYP, PCK). 2141 */ 2142 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck, 2143 Name name, KindSelector kind) { 2144 Name fullname = TypeSymbol.formFullName(name, pck); 2145 Symbol bestSoFar = typeNotFound; 2146 PackageSymbol pack = null; 2147 if (kind.contains(KindSelector.PCK)) { 2148 pack = syms.enterPackage(fullname); 2149 if (pack.exists()) return pack; 2150 } 2151 if (kind.contains(KindSelector.TYP)) { 2152 Symbol sym = loadClass(env, fullname); 2153 if (sym.exists()) { 2154 // don't allow programs to use flatnames 2155 if (name == sym.name) return sym; 2156 } 2157 else bestSoFar = bestOf(bestSoFar, sym); 2158 } 2159 return (pack != null) ? pack : bestSoFar; 2160 } 2161 2162 /** Find an identifier among the members of a given type `site'. 2163 * @param env The current environment. 2164 * @param site The type containing the symbol to be found. 2165 * @param name The identifier's name. 2166 * @param kind Indicates the possible symbol kinds 2167 * (a subset of VAL, TYP). 2168 */ 2169 Symbol findIdentInType(Env<AttrContext> env, Type site, 2170 Name name, KindSelector kind) { 2171 Symbol bestSoFar = typeNotFound; 2172 Symbol sym; 2173 if (kind.contains(KindSelector.VAL)) { 2174 sym = findField(env, site, name, site.tsym); 2175 if (sym.exists()) return sym; 2176 else bestSoFar = bestOf(bestSoFar, sym); 2177 } 2178 2179 if (kind.contains(KindSelector.TYP)) { 2180 sym = findMemberType(env, site, name, site.tsym); 2181 if (sym.exists()) return sym; 2182 else bestSoFar = bestOf(bestSoFar, sym); 2183 } 2184 return bestSoFar; 2185 } 2186 2187/* *************************************************************************** 2188 * Access checking 2189 * The following methods convert ResolveErrors to ErrorSymbols, issuing 2190 * an error message in the process 2191 ****************************************************************************/ 2192 2193 /** If `sym' is a bad symbol: report error and return errSymbol 2194 * else pass through unchanged, 2195 * additional arguments duplicate what has been used in trying to find the 2196 * symbol {@literal (--> flyweight pattern)}. This improves performance since we 2197 * expect misses to happen frequently. 2198 * 2199 * @param sym The symbol that was found, or a ResolveError. 2200 * @param pos The position to use for error reporting. 2201 * @param location The symbol the served as a context for this lookup 2202 * @param site The original type from where the selection took place. 2203 * @param name The symbol's name. 2204 * @param qualified Did we get here through a qualified expression resolution? 2205 * @param argtypes The invocation's value arguments, 2206 * if we looked for a method. 2207 * @param typeargtypes The invocation's type arguments, 2208 * if we looked for a method. 2209 * @param logResolveHelper helper class used to log resolve errors 2210 */ 2211 Symbol accessInternal(Symbol sym, 2212 DiagnosticPosition pos, 2213 Symbol location, 2214 Type site, 2215 Name name, 2216 boolean qualified, 2217 List<Type> argtypes, 2218 List<Type> typeargtypes, 2219 LogResolveHelper logResolveHelper) { 2220 if (sym.kind.isResolutionError()) { 2221 ResolveError errSym = (ResolveError)sym.baseSymbol(); 2222 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol); 2223 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes); 2224 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) { 2225 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes); 2226 } 2227 } 2228 return sym; 2229 } 2230 2231 /** 2232 * Variant of the generalized access routine, to be used for generating method 2233 * resolution diagnostics 2234 */ 2235 Symbol accessMethod(Symbol sym, 2236 DiagnosticPosition pos, 2237 Symbol location, 2238 Type site, 2239 Name name, 2240 boolean qualified, 2241 List<Type> argtypes, 2242 List<Type> typeargtypes) { 2243 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper); 2244 } 2245 2246 /** Same as original accessMethod(), but without location. 2247 */ 2248 Symbol accessMethod(Symbol sym, 2249 DiagnosticPosition pos, 2250 Type site, 2251 Name name, 2252 boolean qualified, 2253 List<Type> argtypes, 2254 List<Type> typeargtypes) { 2255 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes); 2256 } 2257 2258 /** 2259 * Variant of the generalized access routine, to be used for generating variable, 2260 * type resolution diagnostics 2261 */ 2262 Symbol accessBase(Symbol sym, 2263 DiagnosticPosition pos, 2264 Symbol location, 2265 Type site, 2266 Name name, 2267 boolean qualified) { 2268 return accessInternal(sym, pos, location, site, name, qualified, List.<Type>nil(), null, basicLogResolveHelper); 2269 } 2270 2271 /** Same as original accessBase(), but without location. 2272 */ 2273 Symbol accessBase(Symbol sym, 2274 DiagnosticPosition pos, 2275 Type site, 2276 Name name, 2277 boolean qualified) { 2278 return accessBase(sym, pos, site.tsym, site, name, qualified); 2279 } 2280 2281 interface LogResolveHelper { 2282 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes); 2283 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes); 2284 } 2285 2286 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() { 2287 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) { 2288 return !site.isErroneous(); 2289 } 2290 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) { 2291 return argtypes; 2292 } 2293 }; 2294 2295 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() { 2296 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) { 2297 return !site.isErroneous() && 2298 !Type.isErroneous(argtypes) && 2299 (typeargtypes == null || !Type.isErroneous(typeargtypes)); 2300 } 2301 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) { 2302 return argtypes.map(new ResolveDeferredRecoveryMap(AttrMode.SPECULATIVE, accessedSym, currentResolutionContext.step)); 2303 } 2304 }; 2305 2306 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap { 2307 2308 public ResolveDeferredRecoveryMap(AttrMode mode, Symbol msym, MethodResolutionPhase step) { 2309 deferredAttr.super(mode, msym, step); 2310 } 2311 2312 @Override 2313 protected Type typeOf(DeferredType dt) { 2314 Type res = super.typeOf(dt); 2315 if (!res.isErroneous()) { 2316 switch (TreeInfo.skipParens(dt.tree).getTag()) { 2317 case LAMBDA: 2318 case REFERENCE: 2319 return dt; 2320 case CONDEXPR: 2321 return res == Type.recoveryType ? 2322 dt : res; 2323 } 2324 } 2325 return res; 2326 } 2327 } 2328 2329 /** Check that sym is not an abstract method. 2330 */ 2331 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) { 2332 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0) 2333 log.error(pos, "abstract.cant.be.accessed.directly", 2334 kindName(sym), sym, sym.location()); 2335 } 2336 2337/* *************************************************************************** 2338 * Name resolution 2339 * Naming conventions are as for symbol lookup 2340 * Unlike the find... methods these methods will report access errors 2341 ****************************************************************************/ 2342 2343 /** Resolve an unqualified (non-method) identifier. 2344 * @param pos The position to use for error reporting. 2345 * @param env The environment current at the identifier use. 2346 * @param name The identifier's name. 2347 * @param kind The set of admissible symbol kinds for the identifier. 2348 */ 2349 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env, 2350 Name name, KindSelector kind) { 2351 return accessBase( 2352 findIdent(env, name, kind), 2353 pos, env.enclClass.sym.type, name, false); 2354 } 2355 2356 /** Resolve an unqualified method identifier. 2357 * @param pos The position to use for error reporting. 2358 * @param env The environment current at the method invocation. 2359 * @param name The identifier's name. 2360 * @param argtypes The types of the invocation's value arguments. 2361 * @param typeargtypes The types of the invocation's type arguments. 2362 */ 2363 Symbol resolveMethod(DiagnosticPosition pos, 2364 Env<AttrContext> env, 2365 Name name, 2366 List<Type> argtypes, 2367 List<Type> typeargtypes) { 2368 return lookupMethod(env, pos, env.enclClass.sym, resolveMethodCheck, 2369 new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) { 2370 @Override 2371 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2372 return findFun(env, name, argtypes, typeargtypes, 2373 phase.isBoxingRequired(), 2374 phase.isVarargsRequired()); 2375 }}); 2376 } 2377 2378 /** Resolve a qualified method identifier 2379 * @param pos The position to use for error reporting. 2380 * @param env The environment current at the method invocation. 2381 * @param site The type of the qualifying expression, in which 2382 * identifier is searched. 2383 * @param name The identifier's name. 2384 * @param argtypes The types of the invocation's value arguments. 2385 * @param typeargtypes The types of the invocation's type arguments. 2386 */ 2387 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env, 2388 Type site, Name name, List<Type> argtypes, 2389 List<Type> typeargtypes) { 2390 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes); 2391 } 2392 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env, 2393 Symbol location, Type site, Name name, List<Type> argtypes, 2394 List<Type> typeargtypes) { 2395 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes); 2396 } 2397 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext, 2398 DiagnosticPosition pos, Env<AttrContext> env, 2399 Symbol location, Type site, Name name, List<Type> argtypes, 2400 List<Type> typeargtypes) { 2401 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) { 2402 @Override 2403 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2404 return findMethod(env, site, name, argtypes, typeargtypes, 2405 phase.isBoxingRequired(), 2406 phase.isVarargsRequired()); 2407 } 2408 @Override 2409 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 2410 if (sym.kind.isResolutionError()) { 2411 sym = super.access(env, pos, location, sym); 2412 } else if (allowMethodHandles) { 2413 MethodSymbol msym = (MethodSymbol)sym; 2414 if ((msym.flags() & SIGNATURE_POLYMORPHIC) != 0) { 2415 return findPolymorphicSignatureInstance(env, sym, argtypes); 2416 } 2417 } 2418 return sym; 2419 } 2420 }); 2421 } 2422 2423 /** Find or create an implicit method of exactly the given type (after erasure). 2424 * Searches in a side table, not the main scope of the site. 2425 * This emulates the lookup process required by JSR 292 in JVM. 2426 * @param env Attribution environment 2427 * @param spMethod signature polymorphic method - i.e. MH.invokeExact 2428 * @param argtypes The required argument types 2429 */ 2430 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env, 2431 final Symbol spMethod, 2432 List<Type> argtypes) { 2433 Type mtype = infer.instantiatePolymorphicSignatureInstance(env, 2434 (MethodSymbol)spMethod, currentResolutionContext, argtypes); 2435 for (Symbol sym : polymorphicSignatureScope.getSymbolsByName(spMethod.name)) { 2436 if (types.isSameType(mtype, sym.type)) { 2437 return sym; 2438 } 2439 } 2440 2441 // create the desired method 2442 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags; 2443 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) { 2444 @Override 2445 public Symbol baseSymbol() { 2446 return spMethod; 2447 } 2448 }; 2449 if (!mtype.isErroneous()) { // Cache only if kosher. 2450 polymorphicSignatureScope.enter(msym); 2451 } 2452 return msym; 2453 } 2454 2455 /** Resolve a qualified method identifier, throw a fatal error if not 2456 * found. 2457 * @param pos The position to use for error reporting. 2458 * @param env The environment current at the method invocation. 2459 * @param site The type of the qualifying expression, in which 2460 * identifier is searched. 2461 * @param name The identifier's name. 2462 * @param argtypes The types of the invocation's value arguments. 2463 * @param typeargtypes The types of the invocation's type arguments. 2464 */ 2465 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env, 2466 Type site, Name name, 2467 List<Type> argtypes, 2468 List<Type> typeargtypes) { 2469 MethodResolutionContext resolveContext = new MethodResolutionContext(); 2470 resolveContext.internalResolution = true; 2471 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym, 2472 site, name, argtypes, typeargtypes); 2473 if (sym.kind == MTH) return (MethodSymbol)sym; 2474 else throw new FatalError( 2475 diags.fragment("fatal.err.cant.locate.meth", 2476 name)); 2477 } 2478 2479 /** Resolve constructor. 2480 * @param pos The position to use for error reporting. 2481 * @param env The environment current at the constructor invocation. 2482 * @param site The type of class for which a constructor is searched. 2483 * @param argtypes The types of the constructor invocation's value 2484 * arguments. 2485 * @param typeargtypes The types of the constructor invocation's type 2486 * arguments. 2487 */ 2488 Symbol resolveConstructor(DiagnosticPosition pos, 2489 Env<AttrContext> env, 2490 Type site, 2491 List<Type> argtypes, 2492 List<Type> typeargtypes) { 2493 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes); 2494 } 2495 2496 private Symbol resolveConstructor(MethodResolutionContext resolveContext, 2497 final DiagnosticPosition pos, 2498 Env<AttrContext> env, 2499 Type site, 2500 List<Type> argtypes, 2501 List<Type> typeargtypes) { 2502 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) { 2503 @Override 2504 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2505 return findConstructor(pos, env, site, argtypes, typeargtypes, 2506 phase.isBoxingRequired(), 2507 phase.isVarargsRequired()); 2508 } 2509 }); 2510 } 2511 2512 /** Resolve a constructor, throw a fatal error if not found. 2513 * @param pos The position to use for error reporting. 2514 * @param env The environment current at the method invocation. 2515 * @param site The type to be constructed. 2516 * @param argtypes The types of the invocation's value arguments. 2517 * @param typeargtypes The types of the invocation's type arguments. 2518 */ 2519 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env, 2520 Type site, 2521 List<Type> argtypes, 2522 List<Type> typeargtypes) { 2523 MethodResolutionContext resolveContext = new MethodResolutionContext(); 2524 resolveContext.internalResolution = true; 2525 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes); 2526 if (sym.kind == MTH) return (MethodSymbol)sym; 2527 else throw new FatalError( 2528 diags.fragment("fatal.err.cant.locate.ctor", site)); 2529 } 2530 2531 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env, 2532 Type site, List<Type> argtypes, 2533 List<Type> typeargtypes, 2534 boolean allowBoxing, 2535 boolean useVarargs) { 2536 Symbol sym = findMethod(env, site, 2537 names.init, argtypes, 2538 typeargtypes, allowBoxing, 2539 useVarargs); 2540 chk.checkDeprecated(pos, env.info.scope.owner, sym); 2541 return sym; 2542 } 2543 2544 /** Resolve constructor using diamond inference. 2545 * @param pos The position to use for error reporting. 2546 * @param env The environment current at the constructor invocation. 2547 * @param site The type of class for which a constructor is searched. 2548 * The scope of this class has been touched in attribution. 2549 * @param argtypes The types of the constructor invocation's value 2550 * arguments. 2551 * @param typeargtypes The types of the constructor invocation's type 2552 * arguments. 2553 */ 2554 Symbol resolveDiamond(DiagnosticPosition pos, 2555 Env<AttrContext> env, 2556 Type site, 2557 List<Type> argtypes, 2558 List<Type> typeargtypes) { 2559 return lookupMethod(env, pos, site.tsym, resolveMethodCheck, 2560 new BasicLookupHelper(names.init, site, argtypes, typeargtypes) { 2561 @Override 2562 Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase) { 2563 return findDiamond(env, site, argtypes, typeargtypes, 2564 phase.isBoxingRequired(), 2565 phase.isVarargsRequired()); 2566 } 2567 @Override 2568 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 2569 if (sym.kind.isResolutionError()) { 2570 if (sym.kind != WRONG_MTH && 2571 sym.kind != WRONG_MTHS) { 2572 sym = super.access(env, pos, location, sym); 2573 } else { 2574 final JCDiagnostic details = sym.kind == WRONG_MTH ? 2575 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd : 2576 null; 2577 sym = new DiamondError(sym, currentResolutionContext); 2578 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes); 2579 env.info.pendingResolutionPhase = currentResolutionContext.step; 2580 } 2581 } 2582 return sym; 2583 }}); 2584 } 2585 2586 /** This method scans all the constructor symbol in a given class scope - 2587 * assuming that the original scope contains a constructor of the kind: 2588 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo, 2589 * a method check is executed against the modified constructor type: 2590 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond 2591 * inference. The inferred return type of the synthetic constructor IS 2592 * the inferred type for the diamond operator. 2593 */ 2594 private Symbol findDiamond(Env<AttrContext> env, 2595 Type site, 2596 List<Type> argtypes, 2597 List<Type> typeargtypes, 2598 boolean allowBoxing, 2599 boolean useVarargs) { 2600 Symbol bestSoFar = methodNotFound; 2601 TypeSymbol tsym = site.tsym.isInterface() ? syms.objectType.tsym : site.tsym; 2602 for (final Symbol sym : tsym.members().getSymbolsByName(names.init)) { 2603 //- System.out.println(" e " + e.sym); 2604 if (sym.kind == MTH && 2605 (sym.flags_field & SYNTHETIC) == 0) { 2606 List<Type> oldParams = sym.type.hasTag(FORALL) ? 2607 ((ForAll)sym.type).tvars : 2608 List.<Type>nil(); 2609 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams), 2610 types.createMethodTypeWithReturn(sym.type.asMethodType(), site)); 2611 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) { 2612 @Override 2613 public Symbol baseSymbol() { 2614 return sym; 2615 } 2616 }; 2617 bestSoFar = selectBest(env, site, argtypes, typeargtypes, 2618 newConstr, 2619 bestSoFar, 2620 allowBoxing, 2621 useVarargs); 2622 } 2623 } 2624 return bestSoFar; 2625 } 2626 2627 Symbol getMemberReference(DiagnosticPosition pos, 2628 Env<AttrContext> env, 2629 JCMemberReference referenceTree, 2630 Type site, 2631 Name name) { 2632 2633 site = types.capture(site); 2634 2635 ReferenceLookupHelper lookupHelper = makeReferenceLookupHelper( 2636 referenceTree, site, name, List.<Type>nil(), null, VARARITY); 2637 2638 Env<AttrContext> newEnv = env.dup(env.tree, env.info.dup()); 2639 Symbol sym = lookupMethod(newEnv, env.tree.pos(), site.tsym, 2640 nilMethodCheck, lookupHelper); 2641 2642 env.info.pendingResolutionPhase = newEnv.info.pendingResolutionPhase; 2643 2644 return sym; 2645 } 2646 2647 ReferenceLookupHelper makeReferenceLookupHelper(JCMemberReference referenceTree, 2648 Type site, 2649 Name name, 2650 List<Type> argtypes, 2651 List<Type> typeargtypes, 2652 MethodResolutionPhase maxPhase) { 2653 if (!name.equals(names.init)) { 2654 //method reference 2655 return new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase); 2656 } else if (site.hasTag(ARRAY)) { 2657 //array constructor reference 2658 return new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase); 2659 } else { 2660 //class constructor reference 2661 return new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase); 2662 } 2663 } 2664 2665 /** 2666 * Resolution of member references is typically done as a single 2667 * overload resolution step, where the argument types A are inferred from 2668 * the target functional descriptor. 2669 * 2670 * If the member reference is a method reference with a type qualifier, 2671 * a two-step lookup process is performed. The first step uses the 2672 * expected argument list A, while the second step discards the first 2673 * type from A (which is treated as a receiver type). 2674 * 2675 * There are two cases in which inference is performed: (i) if the member 2676 * reference is a constructor reference and the qualifier type is raw - in 2677 * which case diamond inference is used to infer a parameterization for the 2678 * type qualifier; (ii) if the member reference is an unbound reference 2679 * where the type qualifier is raw - in that case, during the unbound lookup 2680 * the receiver argument type is used to infer an instantiation for the raw 2681 * qualifier type. 2682 * 2683 * When a multi-step resolution process is exploited, the process of picking 2684 * the resulting symbol is delegated to an helper class {@link com.sun.tools.javac.comp.Resolve.ReferenceChooser}. 2685 * 2686 * This routine returns a pair (T,S), where S is the member reference symbol, 2687 * and T is the type of the class in which S is defined. This is necessary as 2688 * the type T might be dynamically inferred (i.e. if constructor reference 2689 * has a raw qualifier). 2690 */ 2691 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(Env<AttrContext> env, 2692 JCMemberReference referenceTree, 2693 Type site, 2694 Name name, 2695 List<Type> argtypes, 2696 List<Type> typeargtypes, 2697 MethodCheck methodCheck, 2698 InferenceContext inferenceContext, 2699 ReferenceChooser referenceChooser) { 2700 2701 //step 1 - bound lookup 2702 ReferenceLookupHelper boundLookupHelper = makeReferenceLookupHelper( 2703 referenceTree, site, name, argtypes, typeargtypes, VARARITY); 2704 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup()); 2705 MethodResolutionContext boundSearchResolveContext = new MethodResolutionContext(); 2706 boundSearchResolveContext.methodCheck = methodCheck; 2707 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(), 2708 site.tsym, boundSearchResolveContext, boundLookupHelper); 2709 ReferenceLookupResult boundRes = new ReferenceLookupResult(boundSym, boundSearchResolveContext); 2710 2711 //step 2 - unbound lookup 2712 Symbol unboundSym = methodNotFound; 2713 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup()); 2714 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup(inferenceContext); 2715 ReferenceLookupResult unboundRes = referenceNotFound; 2716 if (unboundLookupHelper != null) { 2717 MethodResolutionContext unboundSearchResolveContext = 2718 new MethodResolutionContext(); 2719 unboundSearchResolveContext.methodCheck = methodCheck; 2720 unboundSym = lookupMethod(unboundEnv, env.tree.pos(), 2721 site.tsym, unboundSearchResolveContext, unboundLookupHelper); 2722 unboundRes = new ReferenceLookupResult(unboundSym, unboundSearchResolveContext); 2723 } 2724 2725 //merge results 2726 Pair<Symbol, ReferenceLookupHelper> res; 2727 Symbol bestSym = referenceChooser.result(boundRes, unboundRes); 2728 res = new Pair<>(bestSym, 2729 bestSym == unboundSym ? unboundLookupHelper : boundLookupHelper); 2730 env.info.pendingResolutionPhase = bestSym == unboundSym ? 2731 unboundEnv.info.pendingResolutionPhase : 2732 boundEnv.info.pendingResolutionPhase; 2733 2734 return res; 2735 } 2736 2737 /** 2738 * This class is used to represent a method reference lookup result. It keeps track of two 2739 * things: (i) the symbol found during a method reference lookup and (ii) the static kind 2740 * of the lookup (see {@link com.sun.tools.javac.comp.Resolve.ReferenceLookupResult.StaticKind}). 2741 */ 2742 static class ReferenceLookupResult { 2743 2744 /** 2745 * Static kind associated with a method reference lookup. Erroneous lookups end up with 2746 * the UNDEFINED kind; successful lookups will end up with either STATIC, NON_STATIC, 2747 * depending on whether all applicable candidates are static or non-static methods, 2748 * respectively. If a successful lookup has both static and non-static applicable methods, 2749 * its kind is set to BOTH. 2750 */ 2751 enum StaticKind { 2752 STATIC, 2753 NON_STATIC, 2754 BOTH, 2755 UNDEFINED; 2756 2757 /** 2758 * Retrieve the static kind associated with a given (method) symbol. 2759 */ 2760 static StaticKind from(Symbol s) { 2761 return s.isStatic() ? 2762 STATIC : NON_STATIC; 2763 } 2764 2765 /** 2766 * Merge two static kinds together. 2767 */ 2768 static StaticKind reduce(StaticKind sk1, StaticKind sk2) { 2769 if (sk1 == UNDEFINED) { 2770 return sk2; 2771 } else if (sk2 == UNDEFINED) { 2772 return sk1; 2773 } else { 2774 return sk1 == sk2 ? sk1 : BOTH; 2775 } 2776 } 2777 } 2778 2779 /** The static kind. */ 2780 StaticKind staticKind; 2781 2782 /** The lookup result. */ 2783 Symbol sym; 2784 2785 ReferenceLookupResult(Symbol sym, MethodResolutionContext resolutionContext) { 2786 this.staticKind = staticKind(sym, resolutionContext); 2787 this.sym = sym; 2788 } 2789 2790 private StaticKind staticKind(Symbol sym, MethodResolutionContext resolutionContext) { 2791 switch (sym.kind) { 2792 case MTH: 2793 case AMBIGUOUS: 2794 return resolutionContext.candidates.stream() 2795 .filter(c -> c.isApplicable() && c.step == resolutionContext.step) 2796 .map(c -> StaticKind.from(c.sym)) 2797 .reduce(StaticKind::reduce) 2798 .orElse(StaticKind.UNDEFINED); 2799 default: 2800 return StaticKind.UNDEFINED; 2801 } 2802 } 2803 2804 /** 2805 * Does this result corresponds to a successful lookup (i.e. one where a method has been found?) 2806 */ 2807 boolean isSuccess() { 2808 return staticKind != StaticKind.UNDEFINED; 2809 } 2810 2811 /** 2812 * Does this result have given static kind? 2813 */ 2814 boolean hasKind(StaticKind sk) { 2815 return this.staticKind == sk; 2816 } 2817 2818 /** 2819 * Error recovery helper: can this lookup result be ignored (for the purpose of returning 2820 * some 'better' result) ? 2821 */ 2822 boolean canIgnore() { 2823 switch (sym.kind) { 2824 case ABSENT_MTH: 2825 return true; 2826 case WRONG_MTH: 2827 InapplicableSymbolError errSym = 2828 (InapplicableSymbolError)sym.baseSymbol(); 2829 return new Template(MethodCheckDiag.ARITY_MISMATCH.regex()) 2830 .matches(errSym.errCandidate().snd); 2831 case WRONG_MTHS: 2832 InapplicableSymbolsError errSyms = 2833 (InapplicableSymbolsError)sym.baseSymbol(); 2834 return errSyms.filterCandidates(errSyms.mapCandidates()).isEmpty(); 2835 default: 2836 return false; 2837 } 2838 } 2839 } 2840 2841 /** 2842 * This abstract class embodies the logic that converts one (bound lookup) or two (unbound lookup) 2843 * {@code ReferenceLookupResult} objects into a (@code Symbol), which is then regarded as the 2844 * result of method reference resolution. 2845 */ 2846 abstract class ReferenceChooser { 2847 /** 2848 * Generate a result from a pair of lookup result objects. This method delegates to the 2849 * appropriate result generation routine. 2850 */ 2851 Symbol result(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) { 2852 return unboundRes != referenceNotFound ? 2853 unboundResult(boundRes, unboundRes) : 2854 boundResult(boundRes); 2855 } 2856 2857 /** 2858 * Generate a symbol from a given bound lookup result. 2859 */ 2860 abstract Symbol boundResult(ReferenceLookupResult boundRes); 2861 2862 /** 2863 * Generate a symbol from a pair of bound/unbound lookup results. 2864 */ 2865 abstract Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes); 2866 } 2867 2868 /** 2869 * This chooser implements the selection strategy used during a full lookup; this logic 2870 * is described in JLS SE 8 (15.3.2). 2871 */ 2872 ReferenceChooser basicReferenceChooser = new ReferenceChooser() { 2873 2874 @Override 2875 Symbol boundResult(ReferenceLookupResult boundRes) { 2876 return !boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC) ? 2877 boundRes.sym : //the search produces a non-static method 2878 new BadMethodReferenceError(boundRes.sym, false); 2879 } 2880 2881 @Override 2882 Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) { 2883 if (boundRes.hasKind(StaticKind.STATIC) && 2884 (!unboundRes.isSuccess() || unboundRes.hasKind(StaticKind.STATIC))) { 2885 //the first search produces a static method and no non-static method is applicable 2886 //during the second search 2887 return boundRes.sym; 2888 } else if (unboundRes.hasKind(StaticKind.NON_STATIC) && 2889 (!boundRes.isSuccess() || boundRes.hasKind(StaticKind.NON_STATIC))) { 2890 //the second search produces a non-static method and no static method is applicable 2891 //during the first search 2892 return unboundRes.sym; 2893 } else if (boundRes.isSuccess() && unboundRes.isSuccess()) { 2894 //both searches produce some result; ambiguity (error recovery) 2895 return ambiguityError(boundRes.sym, unboundRes.sym); 2896 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) { 2897 //Both searches failed to produce a result with correct staticness (i.e. first search 2898 //produces an non-static method). Alternatively, a given search produced a result 2899 //with the right staticness, but the other search has applicable methods with wrong 2900 //staticness (error recovery) 2901 return new BadMethodReferenceError(boundRes.isSuccess() ? boundRes.sym : unboundRes.sym, true); 2902 } else { 2903 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery) 2904 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ? 2905 unboundRes.sym : boundRes.sym; 2906 } 2907 } 2908 }; 2909 2910 /** 2911 * This chooser implements the selection strategy used during an arity-based lookup; this logic 2912 * is described in JLS SE 8 (15.12.2.1). 2913 */ 2914 ReferenceChooser structuralReferenceChooser = new ReferenceChooser() { 2915 2916 @Override 2917 Symbol boundResult(ReferenceLookupResult boundRes) { 2918 return (!boundRes.isSuccess() || !boundRes.hasKind(StaticKind.STATIC)) ? 2919 boundRes.sym : //the search has at least one applicable non-static method 2920 new BadMethodReferenceError(boundRes.sym, false); 2921 } 2922 2923 @Override 2924 Symbol unboundResult(ReferenceLookupResult boundRes, ReferenceLookupResult unboundRes) { 2925 if (boundRes.isSuccess() && !boundRes.hasKind(StaticKind.NON_STATIC)) { 2926 //the first serach has at least one applicable static method 2927 return boundRes.sym; 2928 } else if (unboundRes.isSuccess() && !unboundRes.hasKind(StaticKind.STATIC)) { 2929 //the second search has at least one applicable non-static method 2930 return unboundRes.sym; 2931 } else if (boundRes.isSuccess() || unboundRes.isSuccess()) { 2932 //either the first search produces a non-static method, or second search produces 2933 //a non-static method (error recovery) 2934 return new BadMethodReferenceError(boundRes.isSuccess() ? boundRes.sym : unboundRes.sym, true); 2935 } else { 2936 //both searches fail to produce a result - pick 'better' error using heuristics (error recovery) 2937 return (boundRes.canIgnore() && !unboundRes.canIgnore()) ? 2938 unboundRes.sym : boundRes.sym; 2939 } 2940 } 2941 }; 2942 2943 /** 2944 * Helper for defining custom method-like lookup logic; a lookup helper 2945 * provides hooks for (i) the actual lookup logic and (ii) accessing the 2946 * lookup result (this step might result in compiler diagnostics to be generated) 2947 */ 2948 abstract class LookupHelper { 2949 2950 /** name of the symbol to lookup */ 2951 Name name; 2952 2953 /** location in which the lookup takes place */ 2954 Type site; 2955 2956 /** actual types used during the lookup */ 2957 List<Type> argtypes; 2958 2959 /** type arguments used during the lookup */ 2960 List<Type> typeargtypes; 2961 2962 /** Max overload resolution phase handled by this helper */ 2963 MethodResolutionPhase maxPhase; 2964 2965 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 2966 this.name = name; 2967 this.site = site; 2968 this.argtypes = argtypes; 2969 this.typeargtypes = typeargtypes; 2970 this.maxPhase = maxPhase; 2971 } 2972 2973 /** 2974 * Should lookup stop at given phase with given result 2975 */ 2976 final boolean shouldStop(Symbol sym, MethodResolutionPhase phase) { 2977 return phase.ordinal() > maxPhase.ordinal() || 2978 !sym.kind.isResolutionError() || sym.kind == AMBIGUOUS; 2979 } 2980 2981 /** 2982 * Search for a symbol under a given overload resolution phase - this method 2983 * is usually called several times, once per each overload resolution phase 2984 */ 2985 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase); 2986 2987 /** 2988 * Dump overload resolution info 2989 */ 2990 void debug(DiagnosticPosition pos, Symbol sym) { 2991 //do nothing 2992 } 2993 2994 /** 2995 * Validate the result of the lookup 2996 */ 2997 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym); 2998 } 2999 3000 abstract class BasicLookupHelper extends LookupHelper { 3001 3002 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) { 3003 this(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY); 3004 } 3005 3006 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3007 super(name, site, argtypes, typeargtypes, maxPhase); 3008 } 3009 3010 @Override 3011 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3012 Symbol sym = doLookup(env, phase); 3013 if (sym.kind == AMBIGUOUS) { 3014 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol(); 3015 sym = a_err.mergeAbstracts(site); 3016 } 3017 return sym; 3018 } 3019 3020 abstract Symbol doLookup(Env<AttrContext> env, MethodResolutionPhase phase); 3021 3022 @Override 3023 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 3024 if (sym.kind.isResolutionError()) { 3025 //if nothing is found return the 'first' error 3026 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes); 3027 } 3028 return sym; 3029 } 3030 3031 @Override 3032 void debug(DiagnosticPosition pos, Symbol sym) { 3033 reportVerboseResolutionDiagnostic(pos, name, site, argtypes, typeargtypes, sym); 3034 } 3035 } 3036 3037 /** 3038 * Helper class for member reference lookup. A reference lookup helper 3039 * defines the basic logic for member reference lookup; a method gives 3040 * access to an 'unbound' helper used to perform an unbound member 3041 * reference lookup. 3042 */ 3043 abstract class ReferenceLookupHelper extends LookupHelper { 3044 3045 /** The member reference tree */ 3046 JCMemberReference referenceTree; 3047 3048 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site, 3049 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3050 super(name, site, argtypes, typeargtypes, maxPhase); 3051 this.referenceTree = referenceTree; 3052 } 3053 3054 /** 3055 * Returns an unbound version of this lookup helper. By default, this 3056 * method returns an dummy lookup helper. 3057 */ 3058 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3059 return null; 3060 } 3061 3062 /** 3063 * Get the kind of the member reference 3064 */ 3065 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym); 3066 3067 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) { 3068 if (sym.kind == AMBIGUOUS) { 3069 AmbiguityError a_err = (AmbiguityError)sym.baseSymbol(); 3070 sym = a_err.mergeAbstracts(site); 3071 } 3072 //skip error reporting 3073 return sym; 3074 } 3075 } 3076 3077 /** 3078 * Helper class for method reference lookup. The lookup logic is based 3079 * upon Resolve.findMethod; in certain cases, this helper class has a 3080 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper). 3081 * In such cases, non-static lookup results are thrown away. 3082 */ 3083 class MethodReferenceLookupHelper extends ReferenceLookupHelper { 3084 3085 /** The original method reference lookup site. */ 3086 Type originalSite; 3087 3088 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site, 3089 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3090 super(referenceTree, name, types.skipTypeVars(site, true), argtypes, typeargtypes, maxPhase); 3091 this.originalSite = site; 3092 } 3093 3094 @Override 3095 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3096 return findMethod(env, site, name, argtypes, typeargtypes, 3097 phase.isBoxingRequired(), phase.isVarargsRequired()); 3098 } 3099 3100 @Override 3101 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3102 if (TreeInfo.isStaticSelector(referenceTree.expr, names)) { 3103 if (argtypes.nonEmpty() && 3104 (argtypes.head.hasTag(NONE) || 3105 types.isSubtypeUnchecked(inferenceContext.asUndetVar(argtypes.head), site))) { 3106 return new UnboundMethodReferenceLookupHelper(referenceTree, name, 3107 originalSite, argtypes, typeargtypes, maxPhase); 3108 } else { 3109 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) { 3110 @Override 3111 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3112 return this; 3113 } 3114 3115 @Override 3116 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3117 return methodNotFound; 3118 } 3119 3120 @Override 3121 ReferenceKind referenceKind(Symbol sym) { 3122 Assert.error(); 3123 return null; 3124 } 3125 }; 3126 } 3127 } else { 3128 return super.unboundLookup(inferenceContext); 3129 } 3130 } 3131 3132 @Override 3133 ReferenceKind referenceKind(Symbol sym) { 3134 if (sym.isStatic()) { 3135 return ReferenceKind.STATIC; 3136 } else { 3137 Name selName = TreeInfo.name(referenceTree.getQualifierExpression()); 3138 return selName != null && selName == names._super ? 3139 ReferenceKind.SUPER : 3140 ReferenceKind.BOUND; 3141 } 3142 } 3143 } 3144 3145 /** 3146 * Helper class for unbound method reference lookup. Essentially the same 3147 * as the basic method reference lookup helper; main difference is that static 3148 * lookup results are thrown away. If qualifier type is raw, an attempt to 3149 * infer a parameterized type is made using the first actual argument (that 3150 * would otherwise be ignored during the lookup). 3151 */ 3152 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper { 3153 3154 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site, 3155 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3156 super(referenceTree, name, site, argtypes.tail, typeargtypes, maxPhase); 3157 if (site.isRaw() && !argtypes.head.hasTag(NONE)) { 3158 Type asSuperSite = types.asSuper(argtypes.head, site.tsym); 3159 this.site = types.skipTypeVars(asSuperSite, true); 3160 } 3161 } 3162 3163 @Override 3164 ReferenceLookupHelper unboundLookup(InferenceContext inferenceContext) { 3165 return this; 3166 } 3167 3168 @Override 3169 ReferenceKind referenceKind(Symbol sym) { 3170 return ReferenceKind.UNBOUND; 3171 } 3172 } 3173 3174 /** 3175 * Helper class for array constructor lookup; an array constructor lookup 3176 * is simulated by looking up a method that returns the array type specified 3177 * as qualifier, and that accepts a single int parameter (size of the array). 3178 */ 3179 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper { 3180 3181 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes, 3182 List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3183 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase); 3184 } 3185 3186 @Override 3187 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3188 WriteableScope sc = WriteableScope.create(syms.arrayClass); 3189 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym); 3190 arrayConstr.type = new MethodType(List.<Type>of(syms.intType), site, List.<Type>nil(), syms.methodClass); 3191 sc.enter(arrayConstr); 3192 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false); 3193 } 3194 3195 @Override 3196 ReferenceKind referenceKind(Symbol sym) { 3197 return ReferenceKind.ARRAY_CTOR; 3198 } 3199 } 3200 3201 /** 3202 * Helper class for constructor reference lookup. The lookup logic is based 3203 * upon either Resolve.findMethod or Resolve.findDiamond - depending on 3204 * whether the constructor reference needs diamond inference (this is the case 3205 * if the qualifier type is raw). A special erroneous symbol is returned 3206 * if the lookup returns the constructor of an inner class and there's no 3207 * enclosing instance in scope. 3208 */ 3209 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper { 3210 3211 boolean needsInference; 3212 3213 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes, 3214 List<Type> typeargtypes, MethodResolutionPhase maxPhase) { 3215 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase); 3216 if (site.isRaw()) { 3217 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym, site.getMetadata()); 3218 needsInference = true; 3219 } 3220 } 3221 3222 @Override 3223 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) { 3224 Symbol sym = needsInference ? 3225 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) : 3226 findMethod(env, site, name, argtypes, typeargtypes, 3227 phase.isBoxingRequired(), phase.isVarargsRequired()); 3228 return enclosingInstanceMissing(env, site) ? new BadConstructorReferenceError(sym) : sym; 3229 } 3230 3231 @Override 3232 ReferenceKind referenceKind(Symbol sym) { 3233 return site.getEnclosingType().hasTag(NONE) ? 3234 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER; 3235 } 3236 } 3237 3238 /** 3239 * Main overload resolution routine. On each overload resolution step, a 3240 * lookup helper class is used to perform the method/constructor lookup; 3241 * at the end of the lookup, the helper is used to validate the results 3242 * (this last step might trigger overload resolution diagnostics). 3243 */ 3244 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, MethodCheck methodCheck, LookupHelper lookupHelper) { 3245 MethodResolutionContext resolveContext = new MethodResolutionContext(); 3246 resolveContext.methodCheck = methodCheck; 3247 return lookupMethod(env, pos, location, resolveContext, lookupHelper); 3248 } 3249 3250 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, 3251 MethodResolutionContext resolveContext, LookupHelper lookupHelper) { 3252 MethodResolutionContext prevResolutionContext = currentResolutionContext; 3253 try { 3254 Symbol bestSoFar = methodNotFound; 3255 currentResolutionContext = resolveContext; 3256 for (MethodResolutionPhase phase : methodResolutionSteps) { 3257 if (lookupHelper.shouldStop(bestSoFar, phase)) 3258 break; 3259 MethodResolutionPhase prevPhase = currentResolutionContext.step; 3260 Symbol prevBest = bestSoFar; 3261 currentResolutionContext.step = phase; 3262 Symbol sym = lookupHelper.lookup(env, phase); 3263 lookupHelper.debug(pos, sym); 3264 bestSoFar = phase.mergeResults(bestSoFar, sym); 3265 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase; 3266 } 3267 return lookupHelper.access(env, pos, location, bestSoFar); 3268 } finally { 3269 currentResolutionContext = prevResolutionContext; 3270 } 3271 } 3272 3273 /** 3274 * Resolve `c.name' where name == this or name == super. 3275 * @param pos The position to use for error reporting. 3276 * @param env The environment current at the expression. 3277 * @param c The qualifier. 3278 * @param name The identifier's name. 3279 */ 3280 Symbol resolveSelf(DiagnosticPosition pos, 3281 Env<AttrContext> env, 3282 TypeSymbol c, 3283 Name name) { 3284 Env<AttrContext> env1 = env; 3285 boolean staticOnly = false; 3286 while (env1.outer != null) { 3287 if (isStatic(env1)) staticOnly = true; 3288 if (env1.enclClass.sym == c) { 3289 Symbol sym = env1.info.scope.findFirst(name); 3290 if (sym != null) { 3291 if (staticOnly) sym = new StaticError(sym); 3292 return accessBase(sym, pos, env.enclClass.sym.type, 3293 name, true); 3294 } 3295 } 3296 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true; 3297 env1 = env1.outer; 3298 } 3299 if (c.isInterface() && 3300 name == names._super && !isStatic(env) && 3301 types.isDirectSuperInterface(c, env.enclClass.sym)) { 3302 //this might be a default super call if one of the superinterfaces is 'c' 3303 for (Type t : pruneInterfaces(env.enclClass.type)) { 3304 if (t.tsym == c) { 3305 env.info.defaultSuperCallSite = t; 3306 return new VarSymbol(0, names._super, 3307 types.asSuper(env.enclClass.type, c), env.enclClass.sym); 3308 } 3309 } 3310 //find a direct superinterface that is a subtype of 'c' 3311 for (Type i : types.interfaces(env.enclClass.type)) { 3312 if (i.tsym.isSubClass(c, types) && i.tsym != c) { 3313 log.error(pos, "illegal.default.super.call", c, 3314 diags.fragment("redundant.supertype", c, i)); 3315 return syms.errSymbol; 3316 } 3317 } 3318 Assert.error(); 3319 } 3320 log.error(pos, "not.encl.class", c); 3321 return syms.errSymbol; 3322 } 3323 //where 3324 private List<Type> pruneInterfaces(Type t) { 3325 ListBuffer<Type> result = new ListBuffer<>(); 3326 for (Type t1 : types.interfaces(t)) { 3327 boolean shouldAdd = true; 3328 for (Type t2 : types.interfaces(t)) { 3329 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) { 3330 shouldAdd = false; 3331 } 3332 } 3333 if (shouldAdd) { 3334 result.append(t1); 3335 } 3336 } 3337 return result.toList(); 3338 } 3339 3340 3341 /** 3342 * Resolve `c.this' for an enclosing class c that contains the 3343 * named member. 3344 * @param pos The position to use for error reporting. 3345 * @param env The environment current at the expression. 3346 * @param member The member that must be contained in the result. 3347 */ 3348 Symbol resolveSelfContaining(DiagnosticPosition pos, 3349 Env<AttrContext> env, 3350 Symbol member, 3351 boolean isSuperCall) { 3352 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall); 3353 if (sym == null) { 3354 log.error(pos, "encl.class.required", member); 3355 return syms.errSymbol; 3356 } else { 3357 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true); 3358 } 3359 } 3360 3361 boolean enclosingInstanceMissing(Env<AttrContext> env, Type type) { 3362 if (type.hasTag(CLASS) && type.getEnclosingType().hasTag(CLASS)) { 3363 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false); 3364 return encl == null || encl.kind.isResolutionError(); 3365 } 3366 return false; 3367 } 3368 3369 private Symbol resolveSelfContainingInternal(Env<AttrContext> env, 3370 Symbol member, 3371 boolean isSuperCall) { 3372 Name name = names._this; 3373 Env<AttrContext> env1 = isSuperCall ? env.outer : env; 3374 boolean staticOnly = false; 3375 if (env1 != null) { 3376 while (env1 != null && env1.outer != null) { 3377 if (isStatic(env1)) staticOnly = true; 3378 if (env1.enclClass.sym.isSubClass(member.owner.enclClass(), types)) { 3379 Symbol sym = env1.info.scope.findFirst(name); 3380 if (sym != null) { 3381 if (staticOnly) sym = new StaticError(sym); 3382 return sym; 3383 } 3384 } 3385 if ((env1.enclClass.sym.flags() & STATIC) != 0) 3386 staticOnly = true; 3387 env1 = env1.outer; 3388 } 3389 } 3390 return null; 3391 } 3392 3393 /** 3394 * Resolve an appropriate implicit this instance for t's container. 3395 * JLS 8.8.5.1 and 15.9.2 3396 */ 3397 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) { 3398 return resolveImplicitThis(pos, env, t, false); 3399 } 3400 3401 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) { 3402 Type thisType = (t.tsym.owner.kind.matches(KindSelector.VAL_MTH) 3403 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this) 3404 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type; 3405 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym) 3406 log.error(pos, "cant.ref.before.ctor.called", "this"); 3407 return thisType; 3408 } 3409 3410/* *************************************************************************** 3411 * ResolveError classes, indicating error situations when accessing symbols 3412 ****************************************************************************/ 3413 3414 //used by TransTypes when checking target type of synthetic cast 3415 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) { 3416 AccessError error = new AccessError(env, env.enclClass.type, type.tsym); 3417 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null); 3418 } 3419 //where 3420 private void logResolveError(ResolveError error, 3421 DiagnosticPosition pos, 3422 Symbol location, 3423 Type site, 3424 Name name, 3425 List<Type> argtypes, 3426 List<Type> typeargtypes) { 3427 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR, 3428 pos, location, site, name, argtypes, typeargtypes); 3429 if (d != null) { 3430 d.setFlag(DiagnosticFlag.RESOLVE_ERROR); 3431 log.report(d); 3432 } 3433 } 3434 3435 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args"); 3436 3437 public Object methodArguments(List<Type> argtypes) { 3438 if (argtypes == null || argtypes.isEmpty()) { 3439 return noArgs; 3440 } else { 3441 ListBuffer<Object> diagArgs = new ListBuffer<>(); 3442 for (Type t : argtypes) { 3443 if (t.hasTag(DEFERRED)) { 3444 diagArgs.append(((DeferredAttr.DeferredType)t).tree); 3445 } else { 3446 diagArgs.append(t); 3447 } 3448 } 3449 return diagArgs; 3450 } 3451 } 3452 3453 /** 3454 * Root class for resolution errors. Subclass of ResolveError 3455 * represent a different kinds of resolution error - as such they must 3456 * specify how they map into concrete compiler diagnostics. 3457 */ 3458 abstract class ResolveError extends Symbol { 3459 3460 /** The name of the kind of error, for debugging only. */ 3461 final String debugName; 3462 3463 ResolveError(Kind kind, String debugName) { 3464 super(kind, 0, null, null, null); 3465 this.debugName = debugName; 3466 } 3467 3468 @Override @DefinedBy(Api.LANGUAGE_MODEL) 3469 public <R, P> R accept(ElementVisitor<R, P> v, P p) { 3470 throw new AssertionError(); 3471 } 3472 3473 @Override 3474 public String toString() { 3475 return debugName; 3476 } 3477 3478 @Override 3479 public boolean exists() { 3480 return false; 3481 } 3482 3483 @Override 3484 public boolean isStatic() { 3485 return false; 3486 } 3487 3488 /** 3489 * Create an external representation for this erroneous symbol to be 3490 * used during attribution - by default this returns the symbol of a 3491 * brand new error type which stores the original type found 3492 * during resolution. 3493 * 3494 * @param name the name used during resolution 3495 * @param location the location from which the symbol is accessed 3496 */ 3497 protected Symbol access(Name name, TypeSymbol location) { 3498 return types.createErrorType(name, location, syms.errSymbol.type).tsym; 3499 } 3500 3501 /** 3502 * Create a diagnostic representing this resolution error. 3503 * 3504 * @param dkind The kind of the diagnostic to be created (e.g error). 3505 * @param pos The position to be used for error reporting. 3506 * @param site The original type from where the selection took place. 3507 * @param name The name of the symbol to be resolved. 3508 * @param argtypes The invocation's value arguments, 3509 * if we looked for a method. 3510 * @param typeargtypes The invocation's type arguments, 3511 * if we looked for a method. 3512 */ 3513 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3514 DiagnosticPosition pos, 3515 Symbol location, 3516 Type site, 3517 Name name, 3518 List<Type> argtypes, 3519 List<Type> typeargtypes); 3520 } 3521 3522 /** 3523 * This class is the root class of all resolution errors caused by 3524 * an invalid symbol being found during resolution. 3525 */ 3526 abstract class InvalidSymbolError extends ResolveError { 3527 3528 /** The invalid symbol found during resolution */ 3529 Symbol sym; 3530 3531 InvalidSymbolError(Kind kind, Symbol sym, String debugName) { 3532 super(kind, debugName); 3533 this.sym = sym; 3534 } 3535 3536 @Override 3537 public boolean exists() { 3538 return true; 3539 } 3540 3541 @Override 3542 public String toString() { 3543 return super.toString() + " wrongSym=" + sym; 3544 } 3545 3546 @Override 3547 public Symbol access(Name name, TypeSymbol location) { 3548 if (!sym.kind.isResolutionError() && sym.kind.matches(KindSelector.TYP)) 3549 return types.createErrorType(name, location, sym.type).tsym; 3550 else 3551 return sym; 3552 } 3553 } 3554 3555 /** 3556 * InvalidSymbolError error class indicating that a symbol matching a 3557 * given name does not exists in a given site. 3558 */ 3559 class SymbolNotFoundError extends ResolveError { 3560 3561 SymbolNotFoundError(Kind kind) { 3562 this(kind, "symbol not found error"); 3563 } 3564 3565 SymbolNotFoundError(Kind kind, String debugName) { 3566 super(kind, debugName); 3567 } 3568 3569 @Override 3570 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3571 DiagnosticPosition pos, 3572 Symbol location, 3573 Type site, 3574 Name name, 3575 List<Type> argtypes, 3576 List<Type> typeargtypes) { 3577 argtypes = argtypes == null ? List.<Type>nil() : argtypes; 3578 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes; 3579 if (name == names.error) 3580 return null; 3581 3582 boolean hasLocation = false; 3583 if (location == null) { 3584 location = site.tsym; 3585 } 3586 if (!location.name.isEmpty()) { 3587 if (location.kind == PCK && !site.tsym.exists()) { 3588 return diags.create(dkind, log.currentSource(), pos, 3589 "doesnt.exist", location); 3590 } 3591 hasLocation = !location.name.equals(names._this) && 3592 !location.name.equals(names._super); 3593 } 3594 boolean isConstructor = name == names.init; 3595 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : kind.absentKind(); 3596 Name idname = isConstructor ? site.tsym.name : name; 3597 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation); 3598 if (hasLocation) { 3599 return diags.create(dkind, log.currentSource(), pos, 3600 errKey, kindname, idname, //symbol kindname, name 3601 typeargtypes, args(argtypes), //type parameters and arguments (if any) 3602 getLocationDiag(location, site)); //location kindname, type 3603 } 3604 else { 3605 return diags.create(dkind, log.currentSource(), pos, 3606 errKey, kindname, idname, //symbol kindname, name 3607 typeargtypes, args(argtypes)); //type parameters and arguments (if any) 3608 } 3609 } 3610 //where 3611 private Object args(List<Type> args) { 3612 return args.isEmpty() ? args : methodArguments(args); 3613 } 3614 3615 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) { 3616 String key = "cant.resolve"; 3617 String suffix = hasLocation ? ".location" : ""; 3618 switch (kindname) { 3619 case METHOD: 3620 case CONSTRUCTOR: { 3621 suffix += ".args"; 3622 suffix += hasTypeArgs ? ".params" : ""; 3623 } 3624 } 3625 return key + suffix; 3626 } 3627 private JCDiagnostic getLocationDiag(Symbol location, Type site) { 3628 if (location.kind == VAR) { 3629 return diags.fragment("location.1", 3630 kindName(location), 3631 location, 3632 location.type); 3633 } else { 3634 return diags.fragment("location", 3635 typeKindName(site), 3636 site, 3637 null); 3638 } 3639 } 3640 } 3641 3642 /** 3643 * InvalidSymbolError error class indicating that a given symbol 3644 * (either a method, a constructor or an operand) is not applicable 3645 * given an actual arguments/type argument list. 3646 */ 3647 class InapplicableSymbolError extends ResolveError { 3648 3649 protected MethodResolutionContext resolveContext; 3650 3651 InapplicableSymbolError(MethodResolutionContext context) { 3652 this(WRONG_MTH, "inapplicable symbol error", context); 3653 } 3654 3655 protected InapplicableSymbolError(Kind kind, String debugName, MethodResolutionContext context) { 3656 super(kind, debugName); 3657 this.resolveContext = context; 3658 } 3659 3660 @Override 3661 public String toString() { 3662 return super.toString(); 3663 } 3664 3665 @Override 3666 public boolean exists() { 3667 return true; 3668 } 3669 3670 @Override 3671 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3672 DiagnosticPosition pos, 3673 Symbol location, 3674 Type site, 3675 Name name, 3676 List<Type> argtypes, 3677 List<Type> typeargtypes) { 3678 if (name == names.error) 3679 return null; 3680 3681 Pair<Symbol, JCDiagnostic> c = errCandidate(); 3682 if (compactMethodDiags) { 3683 JCDiagnostic simpleDiag = 3684 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, c.snd); 3685 if (simpleDiag != null) { 3686 return simpleDiag; 3687 } 3688 } 3689 Symbol ws = c.fst.asMemberOf(site, types); 3690 return diags.create(dkind, log.currentSource(), pos, 3691 "cant.apply.symbol", 3692 kindName(ws), 3693 ws.name == names.init ? ws.owner.name : ws.name, 3694 methodArguments(ws.type.getParameterTypes()), 3695 methodArguments(argtypes), 3696 kindName(ws.owner), 3697 ws.owner.type, 3698 c.snd); 3699 } 3700 3701 @Override 3702 public Symbol access(Name name, TypeSymbol location) { 3703 return types.createErrorType(name, location, syms.errSymbol.type).tsym; 3704 } 3705 3706 protected Pair<Symbol, JCDiagnostic> errCandidate() { 3707 Candidate bestSoFar = null; 3708 for (Candidate c : resolveContext.candidates) { 3709 if (c.isApplicable()) continue; 3710 bestSoFar = c; 3711 } 3712 Assert.checkNonNull(bestSoFar); 3713 return new Pair<>(bestSoFar.sym, bestSoFar.details); 3714 } 3715 } 3716 3717 /** 3718 * ResolveError error class indicating that a symbol (either methods, constructors or operand) 3719 * is not applicable given an actual arguments/type argument list. 3720 */ 3721 class InapplicableSymbolsError extends InapplicableSymbolError { 3722 3723 InapplicableSymbolsError(MethodResolutionContext context) { 3724 super(WRONG_MTHS, "inapplicable symbols", context); 3725 } 3726 3727 @Override 3728 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3729 DiagnosticPosition pos, 3730 Symbol location, 3731 Type site, 3732 Name name, 3733 List<Type> argtypes, 3734 List<Type> typeargtypes) { 3735 Map<Symbol, JCDiagnostic> candidatesMap = mapCandidates(); 3736 Map<Symbol, JCDiagnostic> filteredCandidates = compactMethodDiags ? 3737 filterCandidates(candidatesMap) : 3738 mapCandidates(); 3739 if (filteredCandidates.isEmpty()) { 3740 filteredCandidates = candidatesMap; 3741 } 3742 boolean truncatedDiag = candidatesMap.size() != filteredCandidates.size(); 3743 if (filteredCandidates.size() > 1) { 3744 JCDiagnostic err = diags.create(dkind, 3745 null, 3746 truncatedDiag ? 3747 EnumSet.of(DiagnosticFlag.COMPRESSED) : 3748 EnumSet.noneOf(DiagnosticFlag.class), 3749 log.currentSource(), 3750 pos, 3751 "cant.apply.symbols", 3752 name == names.init ? KindName.CONSTRUCTOR : kind.absentKind(), 3753 name == names.init ? site.tsym.name : name, 3754 methodArguments(argtypes)); 3755 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(filteredCandidates, site)); 3756 } else if (filteredCandidates.size() == 1) { 3757 Map.Entry<Symbol, JCDiagnostic> _e = 3758 filteredCandidates.entrySet().iterator().next(); 3759 final Pair<Symbol, JCDiagnostic> p = new Pair<>(_e.getKey(), _e.getValue()); 3760 JCDiagnostic d = new InapplicableSymbolError(resolveContext) { 3761 @Override 3762 protected Pair<Symbol, JCDiagnostic> errCandidate() { 3763 return p; 3764 } 3765 }.getDiagnostic(dkind, pos, 3766 location, site, name, argtypes, typeargtypes); 3767 if (truncatedDiag) { 3768 d.setFlag(DiagnosticFlag.COMPRESSED); 3769 } 3770 return d; 3771 } else { 3772 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos, 3773 location, site, name, argtypes, typeargtypes); 3774 } 3775 } 3776 //where 3777 private Map<Symbol, JCDiagnostic> mapCandidates() { 3778 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<>(); 3779 for (Candidate c : resolveContext.candidates) { 3780 if (c.isApplicable()) continue; 3781 candidates.put(c.sym, c.details); 3782 } 3783 return candidates; 3784 } 3785 3786 Map<Symbol, JCDiagnostic> filterCandidates(Map<Symbol, JCDiagnostic> candidatesMap) { 3787 Map<Symbol, JCDiagnostic> candidates = new LinkedHashMap<>(); 3788 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) { 3789 JCDiagnostic d = _entry.getValue(); 3790 if (!new Template(MethodCheckDiag.ARITY_MISMATCH.regex()).matches(d)) { 3791 candidates.put(_entry.getKey(), d); 3792 } 3793 } 3794 return candidates; 3795 } 3796 3797 private List<JCDiagnostic> candidateDetails(Map<Symbol, JCDiagnostic> candidatesMap, Type site) { 3798 List<JCDiagnostic> details = List.nil(); 3799 for (Map.Entry<Symbol, JCDiagnostic> _entry : candidatesMap.entrySet()) { 3800 Symbol sym = _entry.getKey(); 3801 JCDiagnostic detailDiag = diags.fragment("inapplicable.method", 3802 Kinds.kindName(sym), 3803 sym.location(site, types), 3804 sym.asMemberOf(site, types), 3805 _entry.getValue()); 3806 details = details.prepend(detailDiag); 3807 } 3808 //typically members are visited in reverse order (see Scope) 3809 //so we need to reverse the candidate list so that candidates 3810 //conform to source order 3811 return details; 3812 } 3813 } 3814 3815 /** 3816 * DiamondError error class indicating that a constructor symbol is not applicable 3817 * given an actual arguments/type argument list using diamond inference. 3818 */ 3819 class DiamondError extends InapplicableSymbolError { 3820 3821 Symbol sym; 3822 3823 public DiamondError(Symbol sym, MethodResolutionContext context) { 3824 super(sym.kind, "diamondError", context); 3825 this.sym = sym; 3826 } 3827 3828 JCDiagnostic getDetails() { 3829 return (sym.kind == WRONG_MTH) ? 3830 ((InapplicableSymbolError)sym.baseSymbol()).errCandidate().snd : 3831 null; 3832 } 3833 3834 @Override 3835 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, 3836 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) { 3837 JCDiagnostic details = getDetails(); 3838 if (details != null && compactMethodDiags) { 3839 JCDiagnostic simpleDiag = 3840 MethodResolutionDiagHelper.rewrite(diags, pos, log.currentSource(), dkind, details); 3841 if (simpleDiag != null) { 3842 return simpleDiag; 3843 } 3844 } 3845 String key = details == null ? 3846 "cant.apply.diamond" : 3847 "cant.apply.diamond.1"; 3848 return diags.create(dkind, log.currentSource(), pos, key, 3849 diags.fragment("diamond", site.tsym), details); 3850 } 3851 } 3852 3853 /** 3854 * An InvalidSymbolError error class indicating that a symbol is not 3855 * accessible from a given site 3856 */ 3857 class AccessError extends InvalidSymbolError { 3858 3859 private Env<AttrContext> env; 3860 private Type site; 3861 3862 AccessError(Symbol sym) { 3863 this(null, null, sym); 3864 } 3865 3866 AccessError(Env<AttrContext> env, Type site, Symbol sym) { 3867 super(HIDDEN, sym, "access error"); 3868 this.env = env; 3869 this.site = site; 3870 if (debugResolve) 3871 log.error("proc.messager", sym + " @ " + site + " is inaccessible."); 3872 } 3873 3874 @Override 3875 public boolean exists() { 3876 return false; 3877 } 3878 3879 @Override 3880 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3881 DiagnosticPosition pos, 3882 Symbol location, 3883 Type site, 3884 Name name, 3885 List<Type> argtypes, 3886 List<Type> typeargtypes) { 3887 if (sym.owner.type.hasTag(ERROR)) 3888 return null; 3889 3890 if (sym.name == names.init && sym.owner != site.tsym) { 3891 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, 3892 pos, location, site, name, argtypes, typeargtypes); 3893 } 3894 else if ((sym.flags() & PUBLIC) != 0 3895 || (env != null && this.site != null 3896 && !isAccessible(env, this.site))) { 3897 return diags.create(dkind, log.currentSource(), 3898 pos, "not.def.access.class.intf.cant.access", 3899 sym, sym.location()); 3900 } 3901 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) { 3902 return diags.create(dkind, log.currentSource(), 3903 pos, "report.access", sym, 3904 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)), 3905 sym.location()); 3906 } 3907 else { 3908 return diags.create(dkind, log.currentSource(), 3909 pos, "not.def.public.cant.access", sym, sym.location()); 3910 } 3911 } 3912 } 3913 3914 /** 3915 * InvalidSymbolError error class indicating that an instance member 3916 * has erroneously been accessed from a static context. 3917 */ 3918 class StaticError extends InvalidSymbolError { 3919 3920 StaticError(Symbol sym) { 3921 super(STATICERR, sym, "static error"); 3922 } 3923 3924 @Override 3925 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3926 DiagnosticPosition pos, 3927 Symbol location, 3928 Type site, 3929 Name name, 3930 List<Type> argtypes, 3931 List<Type> typeargtypes) { 3932 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS)) 3933 ? types.erasure(sym.type).tsym 3934 : sym); 3935 return diags.create(dkind, log.currentSource(), pos, 3936 "non-static.cant.be.ref", kindName(sym), errSym); 3937 } 3938 } 3939 3940 /** 3941 * InvalidSymbolError error class indicating that a pair of symbols 3942 * (either methods, constructors or operands) are ambiguous 3943 * given an actual arguments/type argument list. 3944 */ 3945 class AmbiguityError extends ResolveError { 3946 3947 /** The other maximally specific symbol */ 3948 List<Symbol> ambiguousSyms = List.nil(); 3949 3950 @Override 3951 public boolean exists() { 3952 return true; 3953 } 3954 3955 AmbiguityError(Symbol sym1, Symbol sym2) { 3956 super(AMBIGUOUS, "ambiguity error"); 3957 ambiguousSyms = flatten(sym2).appendList(flatten(sym1)); 3958 } 3959 3960 private List<Symbol> flatten(Symbol sym) { 3961 if (sym.kind == AMBIGUOUS) { 3962 return ((AmbiguityError)sym.baseSymbol()).ambiguousSyms; 3963 } else { 3964 return List.of(sym); 3965 } 3966 } 3967 3968 AmbiguityError addAmbiguousSymbol(Symbol s) { 3969 ambiguousSyms = ambiguousSyms.prepend(s); 3970 return this; 3971 } 3972 3973 @Override 3974 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind, 3975 DiagnosticPosition pos, 3976 Symbol location, 3977 Type site, 3978 Name name, 3979 List<Type> argtypes, 3980 List<Type> typeargtypes) { 3981 List<Symbol> diagSyms = ambiguousSyms.reverse(); 3982 Symbol s1 = diagSyms.head; 3983 Symbol s2 = diagSyms.tail.head; 3984 Name sname = s1.name; 3985 if (sname == names.init) sname = s1.owner.name; 3986 return diags.create(dkind, log.currentSource(), 3987 pos, "ref.ambiguous", sname, 3988 kindName(s1), 3989 s1, 3990 s1.location(site, types), 3991 kindName(s2), 3992 s2, 3993 s2.location(site, types)); 3994 } 3995 3996 /** 3997 * If multiple applicable methods are found during overload and none of them 3998 * is more specific than the others, attempt to merge their signatures. 3999 */ 4000 Symbol mergeAbstracts(Type site) { 4001 List<Symbol> ambiguousInOrder = ambiguousSyms.reverse(); 4002 for (Symbol s : ambiguousInOrder) { 4003 Type mt = types.memberType(site, s); 4004 boolean found = true; 4005 List<Type> allThrown = mt.getThrownTypes(); 4006 for (Symbol s2 : ambiguousInOrder) { 4007 Type mt2 = types.memberType(site, s2); 4008 if ((s2.flags() & ABSTRACT) == 0 || 4009 !types.overrideEquivalent(mt, mt2) || 4010 !types.isSameTypes(s.erasure(types).getParameterTypes(), 4011 s2.erasure(types).getParameterTypes())) { 4012 //ambiguity cannot be resolved 4013 return this; 4014 } 4015 Type mst = mostSpecificReturnType(mt, mt2); 4016 if (mst == null || mst != mt) { 4017 found = false; 4018 break; 4019 } 4020 allThrown = chk.intersect(allThrown, mt2.getThrownTypes()); 4021 } 4022 if (found) { 4023 //all ambiguous methods were abstract and one method had 4024 //most specific return type then others 4025 return (allThrown == mt.getThrownTypes()) ? 4026 s : new MethodSymbol( 4027 s.flags(), 4028 s.name, 4029 types.createMethodTypeWithThrown(s.type, allThrown), 4030 s.owner); 4031 } 4032 } 4033 return this; 4034 } 4035 4036 @Override 4037 protected Symbol access(Name name, TypeSymbol location) { 4038 Symbol firstAmbiguity = ambiguousSyms.last(); 4039 return firstAmbiguity.kind == TYP ? 4040 types.createErrorType(name, location, firstAmbiguity.type).tsym : 4041 firstAmbiguity; 4042 } 4043 } 4044 4045 class BadVarargsMethod extends ResolveError { 4046 4047 ResolveError delegatedError; 4048 4049 BadVarargsMethod(ResolveError delegatedError) { 4050 super(delegatedError.kind, "badVarargs"); 4051 this.delegatedError = delegatedError; 4052 } 4053 4054 @Override 4055 public Symbol baseSymbol() { 4056 return delegatedError.baseSymbol(); 4057 } 4058 4059 @Override 4060 protected Symbol access(Name name, TypeSymbol location) { 4061 return delegatedError.access(name, location); 4062 } 4063 4064 @Override 4065 public boolean exists() { 4066 return true; 4067 } 4068 4069 @Override 4070 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) { 4071 return delegatedError.getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes); 4072 } 4073 } 4074 4075 /** 4076 * BadMethodReferenceError error class indicating that a method reference symbol has been found, 4077 * but with the wrong staticness. 4078 */ 4079 class BadMethodReferenceError extends StaticError { 4080 4081 boolean unboundLookup; 4082 4083 public BadMethodReferenceError(Symbol sym, boolean unboundLookup) { 4084 super(sym); 4085 this.unboundLookup = unboundLookup; 4086 } 4087 4088 @Override 4089 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) { 4090 final String key; 4091 if (!unboundLookup) { 4092 key = "bad.static.method.in.bound.lookup"; 4093 } else if (sym.isStatic()) { 4094 key = "bad.static.method.in.unbound.lookup"; 4095 } else { 4096 key = "bad.instance.method.in.unbound.lookup"; 4097 } 4098 return sym.kind.isResolutionError() ? 4099 ((ResolveError)sym).getDiagnostic(dkind, pos, location, site, name, argtypes, typeargtypes) : 4100 diags.create(dkind, log.currentSource(), pos, key, Kinds.kindName(sym), sym); 4101 } 4102 } 4103 4104 /** 4105 * BadConstructorReferenceError error class indicating that a constructor reference symbol has been found, 4106 * but pointing to a class for which an enclosing instance is not available. 4107 */ 4108 class BadConstructorReferenceError extends InvalidSymbolError { 4109 4110 public BadConstructorReferenceError(Symbol sym) { 4111 super(MISSING_ENCL, sym, "BadConstructorReferenceError"); 4112 } 4113 4114 @Override 4115 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) { 4116 return diags.create(dkind, log.currentSource(), pos, 4117 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType()); 4118 } 4119 } 4120 4121 /** 4122 * Helper class for method resolution diagnostic simplification. 4123 * Certain resolution diagnostic are rewritten as simpler diagnostic 4124 * where the enclosing resolution diagnostic (i.e. 'inapplicable method') 4125 * is stripped away, as it doesn't carry additional info. The logic 4126 * for matching a given diagnostic is given in terms of a template 4127 * hierarchy: a diagnostic template can be specified programmatically, 4128 * so that only certain diagnostics are matched. Each templete is then 4129 * associated with a rewriter object that carries out the task of rewtiting 4130 * the diagnostic to a simpler one. 4131 */ 4132 static class MethodResolutionDiagHelper { 4133 4134 /** 4135 * A diagnostic rewriter transforms a method resolution diagnostic 4136 * into a simpler one 4137 */ 4138 interface DiagnosticRewriter { 4139 JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags, 4140 DiagnosticPosition preferedPos, DiagnosticSource preferredSource, 4141 DiagnosticType preferredKind, JCDiagnostic d); 4142 } 4143 4144 /** 4145 * A diagnostic template is made up of two ingredients: (i) a regular 4146 * expression for matching a diagnostic key and (ii) a list of sub-templates 4147 * for matching diagnostic arguments. 4148 */ 4149 static class Template { 4150 4151 /** regex used to match diag key */ 4152 String regex; 4153 4154 /** templates used to match diagnostic args */ 4155 Template[] subTemplates; 4156 4157 Template(String key, Template... subTemplates) { 4158 this.regex = key; 4159 this.subTemplates = subTemplates; 4160 } 4161 4162 /** 4163 * Returns true if the regex matches the diagnostic key and if 4164 * all diagnostic arguments are matches by corresponding sub-templates. 4165 */ 4166 boolean matches(Object o) { 4167 JCDiagnostic d = (JCDiagnostic)o; 4168 Object[] args = d.getArgs(); 4169 if (!d.getCode().matches(regex) || 4170 subTemplates.length != d.getArgs().length) { 4171 return false; 4172 } 4173 for (int i = 0; i < args.length ; i++) { 4174 if (!subTemplates[i].matches(args[i])) { 4175 return false; 4176 } 4177 } 4178 return true; 4179 } 4180 } 4181 4182 /** 4183 * Common rewriter for all argument mismatch simplifications. 4184 */ 4185 static class ArgMismatchRewriter implements DiagnosticRewriter { 4186 4187 /** the index of the subdiagnostic to be used as primary. */ 4188 int causeIndex; 4189 4190 public ArgMismatchRewriter(int causeIndex) { 4191 this.causeIndex = causeIndex; 4192 } 4193 4194 @Override 4195 public JCDiagnostic rewriteDiagnostic(JCDiagnostic.Factory diags, 4196 DiagnosticPosition preferedPos, DiagnosticSource preferredSource, 4197 DiagnosticType preferredKind, JCDiagnostic d) { 4198 JCDiagnostic cause = (JCDiagnostic)d.getArgs()[causeIndex]; 4199 DiagnosticPosition pos = d.getDiagnosticPosition(); 4200 if (pos == null) { 4201 pos = preferedPos; 4202 } 4203 return diags.create(preferredKind, preferredSource, pos, 4204 "prob.found.req", cause); 4205 } 4206 } 4207 4208 /** a dummy template that match any diagnostic argument */ 4209 static final Template skip = new Template("") { 4210 @Override 4211 boolean matches(Object d) { 4212 return true; 4213 } 4214 }; 4215 4216 /** template for matching inference-free arguments mismatch failures */ 4217 static final Template argMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip); 4218 4219 /** template for matching inference related arguments mismatch failures */ 4220 static final Template inferArgMismatchTemplate = new Template(MethodCheckDiag.ARG_MISMATCH.regex(), skip, skip) { 4221 @Override 4222 boolean matches(Object o) { 4223 if (!super.matches(o)) { 4224 return false; 4225 } 4226 JCDiagnostic d = (JCDiagnostic)o; 4227 @SuppressWarnings("unchecked") 4228 List<Type> tvars = (List<Type>)d.getArgs()[0]; 4229 return !containsAny(d, tvars); 4230 } 4231 4232 BiPredicate<Object, List<Type>> containsPredicate = (o, ts) -> { 4233 if (o instanceof Type) { 4234 return ((Type)o).containsAny(ts); 4235 } else if (o instanceof JCDiagnostic) { 4236 return containsAny((JCDiagnostic)o, ts); 4237 } else { 4238 return false; 4239 } 4240 }; 4241 4242 boolean containsAny(JCDiagnostic d, List<Type> ts) { 4243 return Stream.of(d.getArgs()) 4244 .anyMatch(o -> containsPredicate.test(o, ts)); 4245 } 4246 }; 4247 4248 /** rewriter map used for method resolution simplification */ 4249 static final Map<Template, DiagnosticRewriter> rewriters = new LinkedHashMap<>(); 4250 4251 static { 4252 rewriters.put(argMismatchTemplate, new ArgMismatchRewriter(0)); 4253 rewriters.put(inferArgMismatchTemplate, new ArgMismatchRewriter(1)); 4254 } 4255 4256 /** 4257 * Main entry point for diagnostic rewriting - given a diagnostic, see if any templates matches it, 4258 * and rewrite it accordingly. 4259 */ 4260 static JCDiagnostic rewrite(JCDiagnostic.Factory diags, DiagnosticPosition pos, DiagnosticSource source, 4261 DiagnosticType dkind, JCDiagnostic d) { 4262 for (Map.Entry<Template, DiagnosticRewriter> _entry : rewriters.entrySet()) { 4263 if (_entry.getKey().matches(d)) { 4264 JCDiagnostic simpleDiag = 4265 _entry.getValue().rewriteDiagnostic(diags, pos, source, dkind, d); 4266 simpleDiag.setFlag(DiagnosticFlag.COMPRESSED); 4267 return simpleDiag; 4268 } 4269 } 4270 return null; 4271 } 4272 } 4273 4274 enum MethodResolutionPhase { 4275 BASIC(false, false), 4276 BOX(true, false), 4277 VARARITY(true, true) { 4278 @Override 4279 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) { 4280 //Check invariants (see {@code LookupHelper.shouldStop}) 4281 Assert.check(bestSoFar.kind.isResolutionError() && bestSoFar.kind != AMBIGUOUS); 4282 if (!sym.kind.isResolutionError()) { 4283 //varargs resolution successful 4284 return sym; 4285 } else { 4286 //pick best error 4287 switch (bestSoFar.kind) { 4288 case WRONG_MTH: 4289 case WRONG_MTHS: 4290 //Override previous errors if they were caused by argument mismatch. 4291 //This generally means preferring current symbols - but we need to pay 4292 //attention to the fact that the varargs lookup returns 'less' candidates 4293 //than the previous rounds, and adjust that accordingly. 4294 switch (sym.kind) { 4295 case WRONG_MTH: 4296 //if the previous round matched more than one method, return that 4297 //result instead 4298 return bestSoFar.kind == WRONG_MTHS ? 4299 bestSoFar : sym; 4300 case ABSENT_MTH: 4301 //do not override erroneous symbol if the arity lookup did not 4302 //match any method 4303 return bestSoFar; 4304 case WRONG_MTHS: 4305 default: 4306 //safe to override 4307 return sym; 4308 } 4309 default: 4310 //otherwise, return first error 4311 return bestSoFar; 4312 } 4313 } 4314 } 4315 }; 4316 4317 final boolean isBoxingRequired; 4318 final boolean isVarargsRequired; 4319 4320 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) { 4321 this.isBoxingRequired = isBoxingRequired; 4322 this.isVarargsRequired = isVarargsRequired; 4323 } 4324 4325 public boolean isBoxingRequired() { 4326 return isBoxingRequired; 4327 } 4328 4329 public boolean isVarargsRequired() { 4330 return isVarargsRequired; 4331 } 4332 4333 public Symbol mergeResults(Symbol prev, Symbol sym) { 4334 return sym; 4335 } 4336 } 4337 4338 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY); 4339 4340 /** 4341 * A resolution context is used to keep track of intermediate results of 4342 * overload resolution, such as list of method that are not applicable 4343 * (used to generate more precise diagnostics) and so on. Resolution contexts 4344 * can be nested - this means that when each overload resolution routine should 4345 * work within the resolution context it created. 4346 */ 4347 class MethodResolutionContext { 4348 4349 private List<Candidate> candidates = List.nil(); 4350 4351 MethodResolutionPhase step = null; 4352 4353 MethodCheck methodCheck = resolveMethodCheck; 4354 4355 private boolean internalResolution = false; 4356 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE; 4357 4358 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) { 4359 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null); 4360 candidates = candidates.append(c); 4361 } 4362 4363 void addApplicableCandidate(Symbol sym, Type mtype) { 4364 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype); 4365 candidates = candidates.append(c); 4366 } 4367 4368 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext, ResultInfo pendingResult, Warner warn) { 4369 DeferredAttrContext parent = (pendingResult == null) 4370 ? deferredAttr.emptyDeferredAttrContext 4371 : pendingResult.checkContext.deferredAttrContext(); 4372 return deferredAttr.new DeferredAttrContext(attrMode, sym, step, 4373 inferenceContext, parent, warn); 4374 } 4375 4376 /** 4377 * This class represents an overload resolution candidate. There are two 4378 * kinds of candidates: applicable methods and inapplicable methods; 4379 * applicable methods have a pointer to the instantiated method type, 4380 * while inapplicable candidates contain further details about the 4381 * reason why the method has been considered inapplicable. 4382 */ 4383 @SuppressWarnings("overrides") 4384 class Candidate { 4385 4386 final MethodResolutionPhase step; 4387 final Symbol sym; 4388 final JCDiagnostic details; 4389 final Type mtype; 4390 4391 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) { 4392 this.step = step; 4393 this.sym = sym; 4394 this.details = details; 4395 this.mtype = mtype; 4396 } 4397 4398 @Override 4399 public boolean equals(Object o) { 4400 if (o instanceof Candidate) { 4401 Symbol s1 = this.sym; 4402 Symbol s2 = ((Candidate)o).sym; 4403 if ((s1 != s2 && 4404 (s1.overrides(s2, s1.owner.type.tsym, types, false) || 4405 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) || 4406 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner)) 4407 return true; 4408 } 4409 return false; 4410 } 4411 4412 boolean isApplicable() { 4413 return mtype != null; 4414 } 4415 } 4416 4417 DeferredAttr.AttrMode attrMode() { 4418 return attrMode; 4419 } 4420 4421 boolean internal() { 4422 return internalResolution; 4423 } 4424 } 4425 4426 MethodResolutionContext currentResolutionContext = null; 4427} 4428