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src/share/classes/com/sun/tools/javac/comp/Resolve.java@7873d37f5b37
src/share/classes/com/sun/tools/javac/comp/Resolve.java
Mon, 21 Jan 2013 20:13:56 +0000
- author
- mcimadamore
- date
- Mon, 21 Jan 2013 20:13:56 +0000
- changeset 1510
- 7873d37f5b37
- parent 1498
- 1afdf1f1472b
- child 1521
- 71f35e4b93a5
- permissions
- -rw-r--r--
8005244: Implement overload resolution as per latest spec EDR
Summary: Add support for stuck expressions and provisional applicability
Reviewed-by: jjg
1 /*
2 * Copyright (c) 1999, 2012, 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 */
26 package com.sun.tools.javac.comp;
28 import com.sun.tools.javac.api.Formattable.LocalizedString;
29 import com.sun.tools.javac.code.*;
30 import com.sun.tools.javac.code.Symbol.*;
31 import com.sun.tools.javac.code.Type.*;
32 import com.sun.tools.javac.comp.Attr.ResultInfo;
33 import com.sun.tools.javac.comp.Check.CheckContext;
34 import com.sun.tools.javac.comp.DeferredAttr.AttrMode;
35 import com.sun.tools.javac.comp.DeferredAttr.DeferredAttrContext;
36 import com.sun.tools.javac.comp.DeferredAttr.DeferredType;
37 import com.sun.tools.javac.comp.Infer.InferenceContext;
38 import com.sun.tools.javac.comp.Infer.InferenceContext.FreeTypeListener;
39 import com.sun.tools.javac.comp.Resolve.MethodResolutionContext.Candidate;
40 import com.sun.tools.javac.jvm.*;
41 import com.sun.tools.javac.tree.*;
42 import com.sun.tools.javac.tree.JCTree.*;
43 import com.sun.tools.javac.tree.JCTree.JCMemberReference.ReferenceKind;
44 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
45 import com.sun.tools.javac.util.*;
46 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
47 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
48 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
50 import java.util.Arrays;
51 import java.util.Collection;
52 import java.util.EnumMap;
53 import java.util.EnumSet;
54 import java.util.Iterator;
55 import java.util.LinkedHashMap;
56 import java.util.LinkedHashSet;
57 import java.util.Map;
58 import java.util.Set;
60 import javax.lang.model.element.ElementVisitor;
62 import static com.sun.tools.javac.code.Flags.*;
63 import static com.sun.tools.javac.code.Flags.BLOCK;
64 import static com.sun.tools.javac.code.Kinds.*;
65 import static com.sun.tools.javac.code.Kinds.ERRONEOUS;
66 import static com.sun.tools.javac.code.TypeTag.*;
67 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
68 import static com.sun.tools.javac.tree.JCTree.Tag.*;
70 /** Helper class for name resolution, used mostly by the attribution phase.
71 *
72 * <p><b>This is NOT part of any supported API.
73 * If you write code that depends on this, you do so at your own risk.
74 * This code and its internal interfaces are subject to change or
75 * deletion without notice.</b>
76 */
77 public class Resolve {
78 protected static final Context.Key<Resolve> resolveKey =
79 new Context.Key<Resolve>();
81 Names names;
82 Log log;
83 Symtab syms;
84 Attr attr;
85 DeferredAttr deferredAttr;
86 Check chk;
87 Infer infer;
88 ClassReader reader;
89 TreeInfo treeinfo;
90 Types types;
91 JCDiagnostic.Factory diags;
92 public final boolean boxingEnabled; // = source.allowBoxing();
93 public final boolean varargsEnabled; // = source.allowVarargs();
94 public final boolean allowMethodHandles;
95 public final boolean allowDefaultMethods;
96 public final boolean allowStructuralMostSpecific;
97 private final boolean debugResolve;
98 final EnumSet<VerboseResolutionMode> verboseResolutionMode;
100 Scope polymorphicSignatureScope;
102 protected Resolve(Context context) {
103 context.put(resolveKey, this);
104 syms = Symtab.instance(context);
106 varNotFound = new
107 SymbolNotFoundError(ABSENT_VAR);
108 methodNotFound = new
109 SymbolNotFoundError(ABSENT_MTH);
110 typeNotFound = new
111 SymbolNotFoundError(ABSENT_TYP);
113 names = Names.instance(context);
114 log = Log.instance(context);
115 attr = Attr.instance(context);
116 deferredAttr = DeferredAttr.instance(context);
117 chk = Check.instance(context);
118 infer = Infer.instance(context);
119 reader = ClassReader.instance(context);
120 treeinfo = TreeInfo.instance(context);
121 types = Types.instance(context);
122 diags = JCDiagnostic.Factory.instance(context);
123 Source source = Source.instance(context);
124 boxingEnabled = source.allowBoxing();
125 varargsEnabled = source.allowVarargs();
126 Options options = Options.instance(context);
127 debugResolve = options.isSet("debugresolve");
128 verboseResolutionMode = VerboseResolutionMode.getVerboseResolutionMode(options);
129 Target target = Target.instance(context);
130 allowMethodHandles = target.hasMethodHandles();
131 allowDefaultMethods = source.allowDefaultMethods();
132 allowStructuralMostSpecific = source.allowStructuralMostSpecific();
133 polymorphicSignatureScope = new Scope(syms.noSymbol);
135 inapplicableMethodException = new InapplicableMethodException(diags);
136 }
138 /** error symbols, which are returned when resolution fails
139 */
140 private final SymbolNotFoundError varNotFound;
141 private final SymbolNotFoundError methodNotFound;
142 private final SymbolNotFoundError typeNotFound;
144 public static Resolve instance(Context context) {
145 Resolve instance = context.get(resolveKey);
146 if (instance == null)
147 instance = new Resolve(context);
148 return instance;
149 }
151 // <editor-fold defaultstate="collapsed" desc="Verbose resolution diagnostics support">
152 enum VerboseResolutionMode {
153 SUCCESS("success"),
154 FAILURE("failure"),
155 APPLICABLE("applicable"),
156 INAPPLICABLE("inapplicable"),
157 DEFERRED_INST("deferred-inference"),
158 PREDEF("predef"),
159 OBJECT_INIT("object-init"),
160 INTERNAL("internal");
162 final String opt;
164 private VerboseResolutionMode(String opt) {
165 this.opt = opt;
166 }
168 static EnumSet<VerboseResolutionMode> getVerboseResolutionMode(Options opts) {
169 String s = opts.get("verboseResolution");
170 EnumSet<VerboseResolutionMode> res = EnumSet.noneOf(VerboseResolutionMode.class);
171 if (s == null) return res;
172 if (s.contains("all")) {
173 res = EnumSet.allOf(VerboseResolutionMode.class);
174 }
175 Collection<String> args = Arrays.asList(s.split(","));
176 for (VerboseResolutionMode mode : values()) {
177 if (args.contains(mode.opt)) {
178 res.add(mode);
179 } else if (args.contains("-" + mode.opt)) {
180 res.remove(mode);
181 }
182 }
183 return res;
184 }
185 }
187 void reportVerboseResolutionDiagnostic(DiagnosticPosition dpos, Name name, Type site,
188 List<Type> argtypes, List<Type> typeargtypes, Symbol bestSoFar) {
189 boolean success = bestSoFar.kind < ERRONEOUS;
191 if (success && !verboseResolutionMode.contains(VerboseResolutionMode.SUCCESS)) {
192 return;
193 } else if (!success && !verboseResolutionMode.contains(VerboseResolutionMode.FAILURE)) {
194 return;
195 }
197 if (bestSoFar.name == names.init &&
198 bestSoFar.owner == syms.objectType.tsym &&
199 !verboseResolutionMode.contains(VerboseResolutionMode.OBJECT_INIT)) {
200 return; //skip diags for Object constructor resolution
201 } else if (site == syms.predefClass.type &&
202 !verboseResolutionMode.contains(VerboseResolutionMode.PREDEF)) {
203 return; //skip spurious diags for predef symbols (i.e. operators)
204 } else if (currentResolutionContext.internalResolution &&
205 !verboseResolutionMode.contains(VerboseResolutionMode.INTERNAL)) {
206 return;
207 }
209 int pos = 0;
210 int mostSpecificPos = -1;
211 ListBuffer<JCDiagnostic> subDiags = ListBuffer.lb();
212 for (Candidate c : currentResolutionContext.candidates) {
213 if (currentResolutionContext.step != c.step ||
214 (c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.APPLICABLE)) ||
215 (!c.isApplicable() && !verboseResolutionMode.contains(VerboseResolutionMode.INAPPLICABLE))) {
216 continue;
217 } else {
218 subDiags.append(c.isApplicable() ?
219 getVerboseApplicableCandidateDiag(pos, c.sym, c.mtype) :
220 getVerboseInapplicableCandidateDiag(pos, c.sym, c.details));
221 if (c.sym == bestSoFar)
222 mostSpecificPos = pos;
223 pos++;
224 }
225 }
226 String key = success ? "verbose.resolve.multi" : "verbose.resolve.multi.1";
227 List<Type> argtypes2 = Type.map(argtypes,
228 deferredAttr.new RecoveryDeferredTypeMap(AttrMode.SPECULATIVE, bestSoFar, currentResolutionContext.step));
229 JCDiagnostic main = diags.note(log.currentSource(), dpos, key, name,
230 site.tsym, mostSpecificPos, currentResolutionContext.step,
231 methodArguments(argtypes2),
232 methodArguments(typeargtypes));
233 JCDiagnostic d = new JCDiagnostic.MultilineDiagnostic(main, subDiags.toList());
234 log.report(d);
235 }
237 JCDiagnostic getVerboseApplicableCandidateDiag(int pos, Symbol sym, Type inst) {
238 JCDiagnostic subDiag = null;
239 if (sym.type.hasTag(FORALL)) {
240 subDiag = diags.fragment("partial.inst.sig", inst);
241 }
243 String key = subDiag == null ?
244 "applicable.method.found" :
245 "applicable.method.found.1";
247 return diags.fragment(key, pos, sym, subDiag);
248 }
250 JCDiagnostic getVerboseInapplicableCandidateDiag(int pos, Symbol sym, JCDiagnostic subDiag) {
251 return diags.fragment("not.applicable.method.found", pos, sym, subDiag);
252 }
253 // </editor-fold>
255 /* ************************************************************************
256 * Identifier resolution
257 *************************************************************************/
259 /** An environment is "static" if its static level is greater than
260 * the one of its outer environment
261 */
262 protected static boolean isStatic(Env<AttrContext> env) {
263 return env.info.staticLevel > env.outer.info.staticLevel;
264 }
266 /** An environment is an "initializer" if it is a constructor or
267 * an instance initializer.
268 */
269 static boolean isInitializer(Env<AttrContext> env) {
270 Symbol owner = env.info.scope.owner;
271 return owner.isConstructor() ||
272 owner.owner.kind == TYP &&
273 (owner.kind == VAR ||
274 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
275 (owner.flags() & STATIC) == 0;
276 }
278 /** Is class accessible in given evironment?
279 * @param env The current environment.
280 * @param c The class whose accessibility is checked.
281 */
282 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
283 return isAccessible(env, c, false);
284 }
286 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
287 boolean isAccessible = false;
288 switch ((short)(c.flags() & AccessFlags)) {
289 case PRIVATE:
290 isAccessible =
291 env.enclClass.sym.outermostClass() ==
292 c.owner.outermostClass();
293 break;
294 case 0:
295 isAccessible =
296 env.toplevel.packge == c.owner // fast special case
297 ||
298 env.toplevel.packge == c.packge()
299 ||
300 // Hack: this case is added since synthesized default constructors
301 // of anonymous classes should be allowed to access
302 // classes which would be inaccessible otherwise.
303 env.enclMethod != null &&
304 (env.enclMethod.mods.flags & ANONCONSTR) != 0;
305 break;
306 default: // error recovery
307 case PUBLIC:
308 isAccessible = true;
309 break;
310 case PROTECTED:
311 isAccessible =
312 env.toplevel.packge == c.owner // fast special case
313 ||
314 env.toplevel.packge == c.packge()
315 ||
316 isInnerSubClass(env.enclClass.sym, c.owner);
317 break;
318 }
319 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
320 isAccessible :
321 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
322 }
323 //where
324 /** Is given class a subclass of given base class, or an inner class
325 * of a subclass?
326 * Return null if no such class exists.
327 * @param c The class which is the subclass or is contained in it.
328 * @param base The base class
329 */
330 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
331 while (c != null && !c.isSubClass(base, types)) {
332 c = c.owner.enclClass();
333 }
334 return c != null;
335 }
337 boolean isAccessible(Env<AttrContext> env, Type t) {
338 return isAccessible(env, t, false);
339 }
341 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
342 return (t.hasTag(ARRAY))
343 ? isAccessible(env, types.elemtype(t))
344 : isAccessible(env, t.tsym, checkInner);
345 }
347 /** Is symbol accessible as a member of given type in given evironment?
348 * @param env The current environment.
349 * @param site The type of which the tested symbol is regarded
350 * as a member.
351 * @param sym The symbol.
352 */
353 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
354 return isAccessible(env, site, sym, false);
355 }
356 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
357 if (sym.name == names.init && sym.owner != site.tsym) return false;
358 switch ((short)(sym.flags() & AccessFlags)) {
359 case PRIVATE:
360 return
361 (env.enclClass.sym == sym.owner // fast special case
362 ||
363 env.enclClass.sym.outermostClass() ==
364 sym.owner.outermostClass())
365 &&
366 sym.isInheritedIn(site.tsym, types);
367 case 0:
368 return
369 (env.toplevel.packge == sym.owner.owner // fast special case
370 ||
371 env.toplevel.packge == sym.packge())
372 &&
373 isAccessible(env, site, checkInner)
374 &&
375 sym.isInheritedIn(site.tsym, types)
376 &&
377 notOverriddenIn(site, sym);
378 case PROTECTED:
379 return
380 (env.toplevel.packge == sym.owner.owner // fast special case
381 ||
382 env.toplevel.packge == sym.packge()
383 ||
384 isProtectedAccessible(sym, env.enclClass.sym, site)
385 ||
386 // OK to select instance method or field from 'super' or type name
387 // (but type names should be disallowed elsewhere!)
388 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
389 &&
390 isAccessible(env, site, checkInner)
391 &&
392 notOverriddenIn(site, sym);
393 default: // this case includes erroneous combinations as well
394 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
395 }
396 }
397 //where
398 /* `sym' is accessible only if not overridden by
399 * another symbol which is a member of `site'
400 * (because, if it is overridden, `sym' is not strictly
401 * speaking a member of `site'). A polymorphic signature method
402 * cannot be overridden (e.g. MH.invokeExact(Object[])).
403 */
404 private boolean notOverriddenIn(Type site, Symbol sym) {
405 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
406 return true;
407 else {
408 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
409 return (s2 == null || s2 == sym || sym.owner == s2.owner ||
410 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
411 }
412 }
413 //where
414 /** Is given protected symbol accessible if it is selected from given site
415 * and the selection takes place in given class?
416 * @param sym The symbol with protected access
417 * @param c The class where the access takes place
418 * @site The type of the qualifier
419 */
420 private
421 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
422 while (c != null &&
423 !(c.isSubClass(sym.owner, types) &&
424 (c.flags() & INTERFACE) == 0 &&
425 // In JLS 2e 6.6.2.1, the subclass restriction applies
426 // only to instance fields and methods -- types are excluded
427 // regardless of whether they are declared 'static' or not.
428 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || site.tsym.isSubClass(c, types))))
429 c = c.owner.enclClass();
430 return c != null;
431 }
433 /**
434 * Performs a recursive scan of a type looking for accessibility problems
435 * from current attribution environment
436 */
437 void checkAccessibleType(Env<AttrContext> env, Type t) {
438 accessibilityChecker.visit(t, env);
439 }
441 /**
442 * Accessibility type-visitor
443 */
444 Types.SimpleVisitor<Void, Env<AttrContext>> accessibilityChecker =
445 new Types.SimpleVisitor<Void, Env<AttrContext>>() {
447 void visit(List<Type> ts, Env<AttrContext> env) {
448 for (Type t : ts) {
449 visit(t, env);
450 }
451 }
453 public Void visitType(Type t, Env<AttrContext> env) {
454 return null;
455 }
457 @Override
458 public Void visitArrayType(ArrayType t, Env<AttrContext> env) {
459 visit(t.elemtype, env);
460 return null;
461 }
463 @Override
464 public Void visitClassType(ClassType t, Env<AttrContext> env) {
465 visit(t.getTypeArguments(), env);
466 if (!isAccessible(env, t, true)) {
467 accessBase(new AccessError(t.tsym), env.tree.pos(), env.enclClass.sym, t, t.tsym.name, true);
468 }
469 return null;
470 }
472 @Override
473 public Void visitWildcardType(WildcardType t, Env<AttrContext> env) {
474 visit(t.type, env);
475 return null;
476 }
478 @Override
479 public Void visitMethodType(MethodType t, Env<AttrContext> env) {
480 visit(t.getParameterTypes(), env);
481 visit(t.getReturnType(), env);
482 visit(t.getThrownTypes(), env);
483 return null;
484 }
485 };
487 /** Try to instantiate the type of a method so that it fits
488 * given type arguments and argument types. If succesful, return
489 * the method's instantiated type, else return null.
490 * The instantiation will take into account an additional leading
491 * formal parameter if the method is an instance method seen as a member
492 * of un underdetermined site In this case, we treat site as an additional
493 * parameter and the parameters of the class containing the method as
494 * additional type variables that get instantiated.
495 *
496 * @param env The current environment
497 * @param site The type of which the method is a member.
498 * @param m The method symbol.
499 * @param argtypes The invocation's given value arguments.
500 * @param typeargtypes The invocation's given type arguments.
501 * @param allowBoxing Allow boxing conversions of arguments.
502 * @param useVarargs Box trailing arguments into an array for varargs.
503 */
504 Type rawInstantiate(Env<AttrContext> env,
505 Type site,
506 Symbol m,
507 ResultInfo resultInfo,
508 List<Type> argtypes,
509 List<Type> typeargtypes,
510 boolean allowBoxing,
511 boolean useVarargs,
512 MethodCheck methodCheck,
513 Warner warn) throws Infer.InferenceException {
515 Type mt = types.memberType(site, m);
516 // tvars is the list of formal type variables for which type arguments
517 // need to inferred.
518 List<Type> tvars = List.nil();
519 if (typeargtypes == null) typeargtypes = List.nil();
520 if (!mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
521 // This is not a polymorphic method, but typeargs are supplied
522 // which is fine, see JLS 15.12.2.1
523 } else if (mt.hasTag(FORALL) && typeargtypes.nonEmpty()) {
524 ForAll pmt = (ForAll) mt;
525 if (typeargtypes.length() != pmt.tvars.length())
526 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
527 // Check type arguments are within bounds
528 List<Type> formals = pmt.tvars;
529 List<Type> actuals = typeargtypes;
530 while (formals.nonEmpty() && actuals.nonEmpty()) {
531 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
532 pmt.tvars, typeargtypes);
533 for (; bounds.nonEmpty(); bounds = bounds.tail)
534 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
535 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds);
536 formals = formals.tail;
537 actuals = actuals.tail;
538 }
539 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
540 } else if (mt.hasTag(FORALL)) {
541 ForAll pmt = (ForAll) mt;
542 List<Type> tvars1 = types.newInstances(pmt.tvars);
543 tvars = tvars.appendList(tvars1);
544 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
545 }
547 // find out whether we need to go the slow route via infer
548 boolean instNeeded = tvars.tail != null; /*inlined: tvars.nonEmpty()*/
549 for (List<Type> l = argtypes;
550 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
551 l = l.tail) {
552 if (l.head.hasTag(FORALL)) instNeeded = true;
553 }
555 if (instNeeded)
556 return infer.instantiateMethod(env,
557 tvars,
558 (MethodType)mt,
559 resultInfo,
560 m,
561 argtypes,
562 allowBoxing,
563 useVarargs,
564 currentResolutionContext,
565 methodCheck,
566 warn);
568 methodCheck.argumentsAcceptable(env, currentResolutionContext.deferredAttrContext(m, infer.emptyContext),
569 argtypes, mt.getParameterTypes(), warn);
570 return mt;
571 }
573 Type checkMethod(Env<AttrContext> env,
574 Type site,
575 Symbol m,
576 ResultInfo resultInfo,
577 List<Type> argtypes,
578 List<Type> typeargtypes,
579 Warner warn) {
580 MethodResolutionContext prevContext = currentResolutionContext;
581 try {
582 currentResolutionContext = new MethodResolutionContext();
583 currentResolutionContext.attrMode = DeferredAttr.AttrMode.CHECK;
584 MethodResolutionPhase step = currentResolutionContext.step = env.info.pendingResolutionPhase;
585 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
586 step.isBoxingRequired(), step.isVarargsRequired(), resolveMethodCheck, warn);
587 }
588 finally {
589 currentResolutionContext = prevContext;
590 }
591 }
593 /** Same but returns null instead throwing a NoInstanceException
594 */
595 Type instantiate(Env<AttrContext> env,
596 Type site,
597 Symbol m,
598 ResultInfo resultInfo,
599 List<Type> argtypes,
600 List<Type> typeargtypes,
601 boolean allowBoxing,
602 boolean useVarargs,
603 MethodCheck methodCheck,
604 Warner warn) {
605 try {
606 return rawInstantiate(env, site, m, resultInfo, argtypes, typeargtypes,
607 allowBoxing, useVarargs, methodCheck, warn);
608 } catch (InapplicableMethodException ex) {
609 return null;
610 }
611 }
613 /**
614 * This interface defines an entry point that should be used to perform a
615 * method check. A method check usually consist in determining as to whether
616 * a set of types (actuals) is compatible with another set of types (formals).
617 * Since the notion of compatibility can vary depending on the circumstances,
618 * this interfaces allows to easily add new pluggable method check routines.
619 */
620 interface MethodCheck {
621 /**
622 * Main method check routine. A method check usually consist in determining
623 * as to whether a set of types (actuals) is compatible with another set of
624 * types (formals). If an incompatibility is found, an unchecked exception
625 * is assumed to be thrown.
626 */
627 void argumentsAcceptable(Env<AttrContext> env,
628 DeferredAttrContext deferredAttrContext,
629 List<Type> argtypes,
630 List<Type> formals,
631 Warner warn);
632 }
634 /**
635 * Helper enum defining all method check diagnostics (used by resolveMethodCheck).
636 */
637 enum MethodCheckDiag {
638 /**
639 * Actuals and formals differs in length.
640 */
641 ARITY_MISMATCH("arg.length.mismatch", "infer.arg.length.mismatch"),
642 /**
643 * An actual is incompatible with a formal.
644 */
645 ARG_MISMATCH("no.conforming.assignment.exists", "infer.no.conforming.assignment.exists"),
646 /**
647 * An actual is incompatible with the varargs element type.
648 */
649 VARARG_MISMATCH("varargs.argument.mismatch", "infer.varargs.argument.mismatch"),
650 /**
651 * The varargs element type is inaccessible.
652 */
653 INACCESSIBLE_VARARGS("inaccessible.varargs.type", "inaccessible.varargs.type");
655 final String basicKey;
656 final String inferKey;
658 MethodCheckDiag(String basicKey, String inferKey) {
659 this.basicKey = basicKey;
660 this.inferKey = inferKey;
661 }
662 }
664 /**
665 * Main method applicability routine. Given a list of actual types A,
666 * a list of formal types F, determines whether the types in A are
667 * compatible (by method invocation conversion) with the types in F.
668 *
669 * Since this routine is shared between overload resolution and method
670 * type-inference, a (possibly empty) inference context is used to convert
671 * formal types to the corresponding 'undet' form ahead of a compatibility
672 * check so that constraints can be propagated and collected.
673 *
674 * Moreover, if one or more types in A is a deferred type, this routine uses
675 * DeferredAttr in order to perform deferred attribution. If one or more actual
676 * deferred types are stuck, they are placed in a queue and revisited later
677 * after the remainder of the arguments have been seen. If this is not sufficient
678 * to 'unstuck' the argument, a cyclic inference error is called out.
679 *
680 * A method check handler (see above) is used in order to report errors.
681 */
682 MethodCheck resolveMethodCheck = new MethodCheck() {
683 @Override
684 public void argumentsAcceptable(final Env<AttrContext> env,
685 DeferredAttrContext deferredAttrContext,
686 List<Type> argtypes,
687 List<Type> formals,
688 Warner warn) {
689 //should we expand formals?
690 boolean useVarargs = deferredAttrContext.phase.isVarargsRequired();
692 //inference context used during this method check
693 InferenceContext inferenceContext = deferredAttrContext.inferenceContext;
695 Type varargsFormal = useVarargs ? formals.last() : null;
697 if (varargsFormal == null &&
698 argtypes.size() != formals.size()) {
699 report(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
700 }
702 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
703 ResultInfo mresult = methodCheckResult(false, formals.head, deferredAttrContext, warn);
704 mresult.check(null, argtypes.head);
705 argtypes = argtypes.tail;
706 formals = formals.tail;
707 }
709 if (formals.head != varargsFormal) {
710 report(MethodCheckDiag.ARITY_MISMATCH, inferenceContext); // not enough args
711 }
713 if (useVarargs) {
714 //note: if applicability check is triggered by most specific test,
715 //the last argument of a varargs is _not_ an array type (see JLS 15.12.2.5)
716 final Type elt = types.elemtype(varargsFormal);
717 ResultInfo mresult = methodCheckResult(true, elt, deferredAttrContext, warn);
718 while (argtypes.nonEmpty()) {
719 mresult.check(null, argtypes.head);
720 argtypes = argtypes.tail;
721 }
722 //check varargs element type accessibility
723 varargsAccessible(env, elt, inferenceContext);
724 }
725 }
727 private void report(MethodCheckDiag diag, InferenceContext inferenceContext, Object... args) {
728 boolean inferDiag = inferenceContext != infer.emptyContext;
729 InapplicableMethodException ex = inferDiag ?
730 infer.inferenceException : inapplicableMethodException;
731 if (inferDiag && (!diag.inferKey.equals(diag.basicKey))) {
732 Object[] args2 = new Object[args.length + 1];
733 System.arraycopy(args, 0, args2, 1, args.length);
734 args2[0] = inferenceContext.inferenceVars();
735 args = args2;
736 }
737 throw ex.setMessage(inferDiag ? diag.inferKey : diag.basicKey, args);
738 }
740 private void varargsAccessible(final Env<AttrContext> env, final Type t, final InferenceContext inferenceContext) {
741 if (inferenceContext.free(t)) {
742 inferenceContext.addFreeTypeListener(List.of(t), new FreeTypeListener() {
743 @Override
744 public void typesInferred(InferenceContext inferenceContext) {
745 varargsAccessible(env, inferenceContext.asInstType(t, types), inferenceContext);
746 }
747 });
748 } else {
749 if (!isAccessible(env, t)) {
750 Symbol location = env.enclClass.sym;
751 report(MethodCheckDiag.INACCESSIBLE_VARARGS, inferenceContext, t, Kinds.kindName(location), location);
752 }
753 }
754 }
756 private ResultInfo methodCheckResult(final boolean varargsCheck, Type to,
757 final DeferredAttr.DeferredAttrContext deferredAttrContext, Warner rsWarner) {
758 CheckContext checkContext = new MethodCheckContext(!deferredAttrContext.phase.isBoxingRequired(), deferredAttrContext, rsWarner) {
759 MethodCheckDiag methodDiag = varargsCheck ?
760 MethodCheckDiag.VARARG_MISMATCH : MethodCheckDiag.ARG_MISMATCH;
762 @Override
763 public void report(DiagnosticPosition pos, JCDiagnostic details) {
764 report(methodDiag, deferredAttrContext.inferenceContext, details);
765 }
766 };
767 return new MethodResultInfo(to, checkContext);
768 }
769 };
771 /**
772 * Check context to be used during method applicability checks. A method check
773 * context might contain inference variables.
774 */
775 abstract class MethodCheckContext implements CheckContext {
777 boolean strict;
778 DeferredAttrContext deferredAttrContext;
779 Warner rsWarner;
781 public MethodCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner) {
782 this.strict = strict;
783 this.deferredAttrContext = deferredAttrContext;
784 this.rsWarner = rsWarner;
785 }
787 public boolean compatible(Type found, Type req, Warner warn) {
788 return strict ?
789 types.isSubtypeUnchecked(found, deferredAttrContext.inferenceContext.asFree(req, types), warn) :
790 types.isConvertible(found, deferredAttrContext.inferenceContext.asFree(req, types), warn);
791 }
793 public void report(DiagnosticPosition pos, JCDiagnostic details) {
794 throw inapplicableMethodException.setMessage(details);
795 }
797 public Warner checkWarner(DiagnosticPosition pos, Type found, Type req) {
798 return rsWarner;
799 }
801 public InferenceContext inferenceContext() {
802 return deferredAttrContext.inferenceContext;
803 }
805 public DeferredAttrContext deferredAttrContext() {
806 return deferredAttrContext;
807 }
808 }
810 /**
811 * ResultInfo class to be used during method applicability checks. Check
812 * for deferred types goes through special path.
813 */
814 class MethodResultInfo extends ResultInfo {
816 public MethodResultInfo(Type pt, CheckContext checkContext) {
817 attr.super(VAL, pt, checkContext);
818 }
820 @Override
821 protected Type check(DiagnosticPosition pos, Type found) {
822 if (found.hasTag(DEFERRED)) {
823 DeferredType dt = (DeferredType)found;
824 return dt.check(this);
825 } else {
826 return super.check(pos, chk.checkNonVoid(pos, types.capture(types.upperBound(found.baseType()))));
827 }
828 }
830 @Override
831 protected MethodResultInfo dup(Type newPt) {
832 return new MethodResultInfo(newPt, checkContext);
833 }
835 @Override
836 protected ResultInfo dup(CheckContext newContext) {
837 return new MethodResultInfo(pt, newContext);
838 }
839 }
841 /**
842 * Most specific method applicability routine. Given a list of actual types A,
843 * a list of formal types F1, and a list of formal types F2, the routine determines
844 * as to whether the types in F1 can be considered more specific than those in F2 w.r.t.
845 * argument types A.
846 */
847 class MostSpecificCheck implements MethodCheck {
849 boolean strict;
850 List<Type> actuals;
852 MostSpecificCheck(boolean strict, List<Type> actuals) {
853 this.strict = strict;
854 this.actuals = actuals;
855 }
857 @Override
858 public void argumentsAcceptable(final Env<AttrContext> env,
859 DeferredAttrContext deferredAttrContext,
860 List<Type> formals1,
861 List<Type> formals2,
862 Warner warn) {
863 formals2 = adjustArgs(formals2, deferredAttrContext.msym, formals1.length(), deferredAttrContext.phase.isVarargsRequired());
864 while (formals2.nonEmpty()) {
865 ResultInfo mresult = methodCheckResult(formals2.head, deferredAttrContext, warn, actuals.head);
866 mresult.check(null, formals1.head);
867 formals1 = formals1.tail;
868 formals2 = formals2.tail;
869 actuals = actuals.isEmpty() ? actuals : actuals.tail;
870 }
871 }
873 /**
874 * Create a method check context to be used during the most specific applicability check
875 */
876 ResultInfo methodCheckResult(Type to, DeferredAttr.DeferredAttrContext deferredAttrContext,
877 Warner rsWarner, Type actual) {
878 return attr.new ResultInfo(Kinds.VAL, to,
879 new MostSpecificCheckContext(strict, deferredAttrContext, rsWarner, actual));
880 }
882 /**
883 * Subclass of method check context class that implements most specific
884 * method conversion. If the actual type under analysis is a deferred type
885 * a full blown structural analysis is carried out.
886 */
887 class MostSpecificCheckContext extends MethodCheckContext {
889 Type actual;
891 public MostSpecificCheckContext(boolean strict, DeferredAttrContext deferredAttrContext, Warner rsWarner, Type actual) {
892 super(strict, deferredAttrContext, rsWarner);
893 this.actual = actual;
894 }
896 public boolean compatible(Type found, Type req, Warner warn) {
897 if (!allowStructuralMostSpecific || actual == null) {
898 return super.compatible(found, req, warn);
899 } else {
900 switch (actual.getTag()) {
901 case DEFERRED:
902 DeferredType dt = (DeferredType) actual;
903 DeferredType.SpeculativeCache.Entry e = dt.speculativeCache.get(deferredAttrContext.msym, deferredAttrContext.phase);
904 return (e == null || e.speculativeTree == deferredAttr.stuckTree)
905 ? false : mostSpecific(found, req, e.speculativeTree, warn);
906 default:
907 return standaloneMostSpecific(found, req, actual, warn);
908 }
909 }
910 }
912 private boolean mostSpecific(Type t, Type s, JCTree tree, Warner warn) {
913 MostSpecificChecker msc = new MostSpecificChecker(t, s, warn);
914 msc.scan(tree);
915 return msc.result;
916 }
918 boolean polyMostSpecific(Type t1, Type t2, Warner warn) {
919 return (!t1.isPrimitive() && t2.isPrimitive())
920 ? true : super.compatible(t1, t2, warn);
921 }
923 boolean standaloneMostSpecific(Type t1, Type t2, Type exprType, Warner warn) {
924 return (exprType.isPrimitive() == t1.isPrimitive()
925 && exprType.isPrimitive() != t2.isPrimitive())
926 ? true : super.compatible(t1, t2, warn);
927 }
929 /**
930 * Structural checker for most specific.
931 */
932 class MostSpecificChecker extends DeferredAttr.PolyScanner {
934 final Type t;
935 final Type s;
936 final Warner warn;
937 boolean result;
939 MostSpecificChecker(Type t, Type s, Warner warn) {
940 this.t = t;
941 this.s = s;
942 this.warn = warn;
943 result = true;
944 }
946 @Override
947 void skip(JCTree tree) {
948 result &= standaloneMostSpecific(t, s, tree.type, warn);
949 }
951 @Override
952 public void visitConditional(JCConditional tree) {
953 if (tree.polyKind == PolyKind.STANDALONE) {
954 result &= standaloneMostSpecific(t, s, tree.type, warn);
955 } else {
956 super.visitConditional(tree);
957 }
958 }
960 @Override
961 public void visitApply(JCMethodInvocation tree) {
962 result &= (tree.polyKind == PolyKind.STANDALONE)
963 ? standaloneMostSpecific(t, s, tree.type, warn)
964 : polyMostSpecific(t, s, warn);
965 }
967 @Override
968 public void visitNewClass(JCNewClass tree) {
969 result &= (tree.polyKind == PolyKind.STANDALONE)
970 ? standaloneMostSpecific(t, s, tree.type, warn)
971 : polyMostSpecific(t, s, warn);
972 }
974 @Override
975 public void visitReference(JCMemberReference tree) {
976 if (types.isFunctionalInterface(t.tsym) &&
977 types.isFunctionalInterface(s.tsym) &&
978 types.asSuper(t, s.tsym) == null &&
979 types.asSuper(s, t.tsym) == null) {
980 Type desc_t = types.findDescriptorType(t);
981 Type desc_s = types.findDescriptorType(s);
982 if (types.isSameTypes(desc_t.getParameterTypes(), desc_s.getParameterTypes())) {
983 if (!desc_s.getReturnType().hasTag(VOID)) {
984 //perform structural comparison
985 Type ret_t = desc_t.getReturnType();
986 Type ret_s = desc_s.getReturnType();
987 result &= ((tree.refPolyKind == PolyKind.STANDALONE)
988 ? standaloneMostSpecific(ret_t, ret_s, tree.type, warn)
989 : polyMostSpecific(ret_t, ret_s, warn));
990 } else {
991 return;
992 }
993 } else {
994 result &= false;
995 }
996 } else {
997 result &= MostSpecificCheckContext.super.compatible(t, s, warn);
998 }
999 }
1001 @Override
1002 public void visitLambda(JCLambda tree) {
1003 if (types.isFunctionalInterface(t.tsym) &&
1004 types.isFunctionalInterface(s.tsym) &&
1005 types.asSuper(t, s.tsym) == null &&
1006 types.asSuper(s, t.tsym) == null) {
1007 Type desc_t = types.findDescriptorType(t);
1008 Type desc_s = types.findDescriptorType(s);
1009 if (tree.paramKind == JCLambda.ParameterKind.EXPLICIT
1010 || types.isSameTypes(desc_t.getParameterTypes(), desc_s.getParameterTypes())) {
1011 if (!desc_s.getReturnType().hasTag(VOID)) {
1012 //perform structural comparison
1013 Type ret_t = desc_t.getReturnType();
1014 Type ret_s = desc_s.getReturnType();
1015 scanLambdaBody(tree, ret_t, ret_s);
1016 } else {
1017 return;
1018 }
1019 } else {
1020 result &= false;
1021 }
1022 } else {
1023 result &= MostSpecificCheckContext.super.compatible(t, s, warn);
1024 }
1025 }
1026 //where
1028 void scanLambdaBody(JCLambda lambda, final Type t, final Type s) {
1029 if (lambda.getBodyKind() == JCTree.JCLambda.BodyKind.EXPRESSION) {
1030 result &= MostSpecificCheckContext.this.mostSpecific(t, s, lambda.body, warn);
1031 } else {
1032 DeferredAttr.LambdaReturnScanner lambdaScanner =
1033 new DeferredAttr.LambdaReturnScanner() {
1034 @Override
1035 public void visitReturn(JCReturn tree) {
1036 if (tree.expr != null) {
1037 result &= MostSpecificCheckContext.this.mostSpecific(t, s, tree.expr, warn);
1038 }
1039 }
1040 };
1041 lambdaScanner.scan(lambda.body);
1042 }
1043 }
1044 }
1045 }
1046 }
1048 public static class InapplicableMethodException extends RuntimeException {
1049 private static final long serialVersionUID = 0;
1051 JCDiagnostic diagnostic;
1052 JCDiagnostic.Factory diags;
1054 InapplicableMethodException(JCDiagnostic.Factory diags) {
1055 this.diagnostic = null;
1056 this.diags = diags;
1057 }
1058 InapplicableMethodException setMessage() {
1059 return setMessage((JCDiagnostic)null);
1060 }
1061 InapplicableMethodException setMessage(String key) {
1062 return setMessage(key != null ? diags.fragment(key) : null);
1063 }
1064 InapplicableMethodException setMessage(String key, Object... args) {
1065 return setMessage(key != null ? diags.fragment(key, args) : null);
1066 }
1067 InapplicableMethodException setMessage(JCDiagnostic diag) {
1068 this.diagnostic = diag;
1069 return this;
1070 }
1072 public JCDiagnostic getDiagnostic() {
1073 return diagnostic;
1074 }
1075 }
1076 private final InapplicableMethodException inapplicableMethodException;
1078 /* ***************************************************************************
1079 * Symbol lookup
1080 * the following naming conventions for arguments are used
1081 *
1082 * env is the environment where the symbol was mentioned
1083 * site is the type of which the symbol is a member
1084 * name is the symbol's name
1085 * if no arguments are given
1086 * argtypes are the value arguments, if we search for a method
1087 *
1088 * If no symbol was found, a ResolveError detailing the problem is returned.
1089 ****************************************************************************/
1091 /** Find field. Synthetic fields are always skipped.
1092 * @param env The current environment.
1093 * @param site The original type from where the selection takes place.
1094 * @param name The name of the field.
1095 * @param c The class to search for the field. This is always
1096 * a superclass or implemented interface of site's class.
1097 */
1098 Symbol findField(Env<AttrContext> env,
1099 Type site,
1100 Name name,
1101 TypeSymbol c) {
1102 while (c.type.hasTag(TYPEVAR))
1103 c = c.type.getUpperBound().tsym;
1104 Symbol bestSoFar = varNotFound;
1105 Symbol sym;
1106 Scope.Entry e = c.members().lookup(name);
1107 while (e.scope != null) {
1108 if (e.sym.kind == VAR && (e.sym.flags_field & SYNTHETIC) == 0) {
1109 return isAccessible(env, site, e.sym)
1110 ? e.sym : new AccessError(env, site, e.sym);
1111 }
1112 e = e.next();
1113 }
1114 Type st = types.supertype(c.type);
1115 if (st != null && (st.hasTag(CLASS) || st.hasTag(TYPEVAR))) {
1116 sym = findField(env, site, name, st.tsym);
1117 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1118 }
1119 for (List<Type> l = types.interfaces(c.type);
1120 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1121 l = l.tail) {
1122 sym = findField(env, site, name, l.head.tsym);
1123 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1124 sym.owner != bestSoFar.owner)
1125 bestSoFar = new AmbiguityError(bestSoFar, sym);
1126 else if (sym.kind < bestSoFar.kind)
1127 bestSoFar = sym;
1128 }
1129 return bestSoFar;
1130 }
1132 /** Resolve a field identifier, throw a fatal error if not found.
1133 * @param pos The position to use for error reporting.
1134 * @param env The environment current at the method invocation.
1135 * @param site The type of the qualifying expression, in which
1136 * identifier is searched.
1137 * @param name The identifier's name.
1138 */
1139 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
1140 Type site, Name name) {
1141 Symbol sym = findField(env, site, name, site.tsym);
1142 if (sym.kind == VAR) return (VarSymbol)sym;
1143 else throw new FatalError(
1144 diags.fragment("fatal.err.cant.locate.field",
1145 name));
1146 }
1148 /** Find unqualified variable or field with given name.
1149 * Synthetic fields always skipped.
1150 * @param env The current environment.
1151 * @param name The name of the variable or field.
1152 */
1153 Symbol findVar(Env<AttrContext> env, Name name) {
1154 Symbol bestSoFar = varNotFound;
1155 Symbol sym;
1156 Env<AttrContext> env1 = env;
1157 boolean staticOnly = false;
1158 while (env1.outer != null) {
1159 if (isStatic(env1)) staticOnly = true;
1160 Scope.Entry e = env1.info.scope.lookup(name);
1161 while (e.scope != null &&
1162 (e.sym.kind != VAR ||
1163 (e.sym.flags_field & SYNTHETIC) != 0))
1164 e = e.next();
1165 sym = (e.scope != null)
1166 ? e.sym
1167 : findField(
1168 env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
1169 if (sym.exists()) {
1170 if (staticOnly &&
1171 sym.kind == VAR &&
1172 sym.owner.kind == TYP &&
1173 (sym.flags() & STATIC) == 0)
1174 return new StaticError(sym);
1175 else
1176 return sym;
1177 } else if (sym.kind < bestSoFar.kind) {
1178 bestSoFar = sym;
1179 }
1181 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1182 env1 = env1.outer;
1183 }
1185 sym = findField(env, syms.predefClass.type, name, syms.predefClass);
1186 if (sym.exists())
1187 return sym;
1188 if (bestSoFar.exists())
1189 return bestSoFar;
1191 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1192 for (; e.scope != null; e = e.next()) {
1193 sym = e.sym;
1194 Type origin = e.getOrigin().owner.type;
1195 if (sym.kind == VAR) {
1196 if (e.sym.owner.type != origin)
1197 sym = sym.clone(e.getOrigin().owner);
1198 return isAccessible(env, origin, sym)
1199 ? sym : new AccessError(env, origin, sym);
1200 }
1201 }
1203 Symbol origin = null;
1204 e = env.toplevel.starImportScope.lookup(name);
1205 for (; e.scope != null; e = e.next()) {
1206 sym = e.sym;
1207 if (sym.kind != VAR)
1208 continue;
1209 // invariant: sym.kind == VAR
1210 if (bestSoFar.kind < AMBIGUOUS && sym.owner != bestSoFar.owner)
1211 return new AmbiguityError(bestSoFar, sym);
1212 else if (bestSoFar.kind >= VAR) {
1213 origin = e.getOrigin().owner;
1214 bestSoFar = isAccessible(env, origin.type, sym)
1215 ? sym : new AccessError(env, origin.type, sym);
1216 }
1217 }
1218 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
1219 return bestSoFar.clone(origin);
1220 else
1221 return bestSoFar;
1222 }
1224 Warner noteWarner = new Warner();
1226 /** Select the best method for a call site among two choices.
1227 * @param env The current environment.
1228 * @param site The original type from where the
1229 * selection takes place.
1230 * @param argtypes The invocation's value arguments,
1231 * @param typeargtypes The invocation's type arguments,
1232 * @param sym Proposed new best match.
1233 * @param bestSoFar Previously found best match.
1234 * @param allowBoxing Allow boxing conversions of arguments.
1235 * @param useVarargs Box trailing arguments into an array for varargs.
1236 */
1237 @SuppressWarnings("fallthrough")
1238 Symbol selectBest(Env<AttrContext> env,
1239 Type site,
1240 List<Type> argtypes,
1241 List<Type> typeargtypes,
1242 Symbol sym,
1243 Symbol bestSoFar,
1244 boolean allowBoxing,
1245 boolean useVarargs,
1246 boolean operator) {
1247 if (sym.kind == ERR ||
1248 !sym.isInheritedIn(site.tsym, types) ||
1249 (useVarargs && (sym.flags() & VARARGS) == 0)) {
1250 return bestSoFar;
1251 }
1252 Assert.check(sym.kind < AMBIGUOUS);
1253 try {
1254 Type mt = rawInstantiate(env, site, sym, null, argtypes, typeargtypes,
1255 allowBoxing, useVarargs, resolveMethodCheck, types.noWarnings);
1256 if (!operator)
1257 currentResolutionContext.addApplicableCandidate(sym, mt);
1258 } catch (InapplicableMethodException ex) {
1259 if (!operator)
1260 currentResolutionContext.addInapplicableCandidate(sym, ex.getDiagnostic());
1261 switch (bestSoFar.kind) {
1262 case ABSENT_MTH:
1263 return new InapplicableSymbolError(currentResolutionContext);
1264 case WRONG_MTH:
1265 if (operator) return bestSoFar;
1266 bestSoFar = new InapplicableSymbolsError(currentResolutionContext);
1267 default:
1268 return bestSoFar;
1269 }
1270 }
1271 if (!isAccessible(env, site, sym)) {
1272 return (bestSoFar.kind == ABSENT_MTH)
1273 ? new AccessError(env, site, sym)
1274 : bestSoFar;
1275 }
1276 return (bestSoFar.kind > AMBIGUOUS)
1277 ? sym
1278 : mostSpecific(argtypes, sym, bestSoFar, env, site,
1279 allowBoxing && operator, useVarargs);
1280 }
1282 /* Return the most specific of the two methods for a call,
1283 * given that both are accessible and applicable.
1284 * @param m1 A new candidate for most specific.
1285 * @param m2 The previous most specific candidate.
1286 * @param env The current environment.
1287 * @param site The original type from where the selection
1288 * takes place.
1289 * @param allowBoxing Allow boxing conversions of arguments.
1290 * @param useVarargs Box trailing arguments into an array for varargs.
1291 */
1292 Symbol mostSpecific(List<Type> argtypes, Symbol m1,
1293 Symbol m2,
1294 Env<AttrContext> env,
1295 final Type site,
1296 boolean allowBoxing,
1297 boolean useVarargs) {
1298 switch (m2.kind) {
1299 case MTH:
1300 if (m1 == m2) return m1;
1301 boolean m1SignatureMoreSpecific =
1302 signatureMoreSpecific(argtypes, env, site, m1, m2, allowBoxing, useVarargs);
1303 boolean m2SignatureMoreSpecific =
1304 signatureMoreSpecific(argtypes, env, site, m2, m1, allowBoxing, useVarargs);
1305 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
1306 Type mt1 = types.memberType(site, m1);
1307 Type mt2 = types.memberType(site, m2);
1308 if (!types.overrideEquivalent(mt1, mt2))
1309 return ambiguityError(m1, m2);
1311 // same signature; select (a) the non-bridge method, or
1312 // (b) the one that overrides the other, or (c) the concrete
1313 // one, or (d) merge both abstract signatures
1314 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
1315 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
1317 // if one overrides or hides the other, use it
1318 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
1319 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
1320 if (types.asSuper(m1Owner.type, m2Owner) != null &&
1321 ((m1.owner.flags_field & INTERFACE) == 0 ||
1322 (m2.owner.flags_field & INTERFACE) != 0) &&
1323 m1.overrides(m2, m1Owner, types, false))
1324 return m1;
1325 if (types.asSuper(m2Owner.type, m1Owner) != null &&
1326 ((m2.owner.flags_field & INTERFACE) == 0 ||
1327 (m1.owner.flags_field & INTERFACE) != 0) &&
1328 m2.overrides(m1, m2Owner, types, false))
1329 return m2;
1330 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
1331 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
1332 if (m1Abstract && !m2Abstract) return m2;
1333 if (m2Abstract && !m1Abstract) return m1;
1334 // both abstract or both concrete
1335 return ambiguityError(m1, m2);
1336 }
1337 if (m1SignatureMoreSpecific) return m1;
1338 if (m2SignatureMoreSpecific) return m2;
1339 return ambiguityError(m1, m2);
1340 case AMBIGUOUS:
1341 //check if m1 is more specific than all ambiguous methods in m2
1342 AmbiguityError e = (AmbiguityError)m2;
1343 for (Symbol s : e.ambiguousSyms) {
1344 if (mostSpecific(argtypes, m1, s, env, site, allowBoxing, useVarargs) != m1) {
1345 return e.addAmbiguousSymbol(m1);
1346 }
1347 }
1348 return m1;
1349 default:
1350 throw new AssertionError();
1351 }
1352 }
1353 //where
1354 private boolean signatureMoreSpecific(List<Type> actuals, Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean allowBoxing, boolean useVarargs) {
1355 noteWarner.clear();
1356 int maxLength = Math.max(
1357 Math.max(m1.type.getParameterTypes().length(), actuals.length()),
1358 m2.type.getParameterTypes().length());
1359 Type mst = instantiate(env, site, m2, null,
1360 adjustArgs(types.lowerBounds(types.memberType(site, m1).getParameterTypes()), m1, maxLength, useVarargs), null,
1361 allowBoxing, useVarargs, new MostSpecificCheck(!allowBoxing, actuals), noteWarner);
1362 return mst != null &&
1363 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
1364 }
1365 private List<Type> adjustArgs(List<Type> args, Symbol msym, int length, boolean allowVarargs) {
1366 if ((msym.flags() & VARARGS) != 0 && allowVarargs) {
1367 Type varargsElem = types.elemtype(args.last());
1368 if (varargsElem == null) {
1369 Assert.error("Bad varargs = " + args.last() + " " + msym);
1370 }
1371 List<Type> newArgs = args.reverse().tail.prepend(varargsElem).reverse();
1372 while (newArgs.length() < length) {
1373 newArgs = newArgs.append(newArgs.last());
1374 }
1375 return newArgs;
1376 } else {
1377 return args;
1378 }
1379 }
1380 //where
1381 Type mostSpecificReturnType(Type mt1, Type mt2) {
1382 Type rt1 = mt1.getReturnType();
1383 Type rt2 = mt2.getReturnType();
1385 if (mt1.hasTag(FORALL) && mt2.hasTag(FORALL)) {
1386 //if both are generic methods, adjust return type ahead of subtyping check
1387 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments());
1388 }
1389 //first use subtyping, then return type substitutability
1390 if (types.isSubtype(rt1, rt2)) {
1391 return mt1;
1392 } else if (types.isSubtype(rt2, rt1)) {
1393 return mt2;
1394 } else if (types.returnTypeSubstitutable(mt1, mt2)) {
1395 return mt1;
1396 } else if (types.returnTypeSubstitutable(mt2, mt1)) {
1397 return mt2;
1398 } else {
1399 return null;
1400 }
1401 }
1402 //where
1403 Symbol ambiguityError(Symbol m1, Symbol m2) {
1404 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
1405 return (m1.flags() & CLASH) == 0 ? m1 : m2;
1406 } else {
1407 return new AmbiguityError(m1, m2);
1408 }
1409 }
1411 Symbol findMethodInScope(Env<AttrContext> env,
1412 Type site,
1413 Name name,
1414 List<Type> argtypes,
1415 List<Type> typeargtypes,
1416 Scope sc,
1417 Symbol bestSoFar,
1418 boolean allowBoxing,
1419 boolean useVarargs,
1420 boolean operator,
1421 boolean abstractok) {
1422 for (Symbol s : sc.getElementsByName(name, new LookupFilter(abstractok))) {
1423 bestSoFar = selectBest(env, site, argtypes, typeargtypes, s,
1424 bestSoFar, allowBoxing, useVarargs, operator);
1425 }
1426 return bestSoFar;
1427 }
1428 //where
1429 class LookupFilter implements Filter<Symbol> {
1431 boolean abstractOk;
1433 LookupFilter(boolean abstractOk) {
1434 this.abstractOk = abstractOk;
1435 }
1437 public boolean accepts(Symbol s) {
1438 long flags = s.flags();
1439 return s.kind == MTH &&
1440 (flags & SYNTHETIC) == 0 &&
1441 (abstractOk ||
1442 (flags & DEFAULT) != 0 ||
1443 (flags & ABSTRACT) == 0);
1444 }
1445 };
1447 /** Find best qualified method matching given name, type and value
1448 * arguments.
1449 * @param env The current environment.
1450 * @param site The original type from where the selection
1451 * takes place.
1452 * @param name The method's name.
1453 * @param argtypes The method's value arguments.
1454 * @param typeargtypes The method's type arguments
1455 * @param allowBoxing Allow boxing conversions of arguments.
1456 * @param useVarargs Box trailing arguments into an array for varargs.
1457 */
1458 Symbol findMethod(Env<AttrContext> env,
1459 Type site,
1460 Name name,
1461 List<Type> argtypes,
1462 List<Type> typeargtypes,
1463 boolean allowBoxing,
1464 boolean useVarargs,
1465 boolean operator) {
1466 Symbol bestSoFar = methodNotFound;
1467 bestSoFar = findMethod(env,
1468 site,
1469 name,
1470 argtypes,
1471 typeargtypes,
1472 site.tsym.type,
1473 bestSoFar,
1474 allowBoxing,
1475 useVarargs,
1476 operator);
1477 reportVerboseResolutionDiagnostic(env.tree.pos(), name, site, argtypes, typeargtypes, bestSoFar);
1478 return bestSoFar;
1479 }
1480 // where
1481 private Symbol findMethod(Env<AttrContext> env,
1482 Type site,
1483 Name name,
1484 List<Type> argtypes,
1485 List<Type> typeargtypes,
1486 Type intype,
1487 Symbol bestSoFar,
1488 boolean allowBoxing,
1489 boolean useVarargs,
1490 boolean operator) {
1491 @SuppressWarnings({"unchecked","rawtypes"})
1492 List<Type>[] itypes = (List<Type>[])new List[] { List.<Type>nil(), List.<Type>nil() };
1493 InterfaceLookupPhase iphase = InterfaceLookupPhase.ABSTRACT_OK;
1494 for (TypeSymbol s : superclasses(intype)) {
1495 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1496 s.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1497 if (name == names.init) return bestSoFar;
1498 iphase = (iphase == null) ? null : iphase.update(s, this);
1499 if (iphase != null) {
1500 for (Type itype : types.interfaces(s.type)) {
1501 itypes[iphase.ordinal()] = types.union(types.closure(itype), itypes[iphase.ordinal()]);
1502 }
1503 }
1504 }
1506 Symbol concrete = bestSoFar.kind < ERR &&
1507 (bestSoFar.flags() & ABSTRACT) == 0 ?
1508 bestSoFar : methodNotFound;
1510 for (InterfaceLookupPhase iphase2 : InterfaceLookupPhase.values()) {
1511 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK && !allowDefaultMethods) break;
1512 //keep searching for abstract methods
1513 for (Type itype : itypes[iphase2.ordinal()]) {
1514 if (!itype.isInterface()) continue; //skip j.l.Object (included by Types.closure())
1515 if (iphase2 == InterfaceLookupPhase.DEFAULT_OK &&
1516 (itype.tsym.flags() & DEFAULT) == 0) continue;
1517 bestSoFar = findMethodInScope(env, site, name, argtypes, typeargtypes,
1518 itype.tsym.members(), bestSoFar, allowBoxing, useVarargs, operator, true);
1519 if (concrete != bestSoFar &&
1520 concrete.kind < ERR && bestSoFar.kind < ERR &&
1521 types.isSubSignature(concrete.type, bestSoFar.type)) {
1522 //this is an hack - as javac does not do full membership checks
1523 //most specific ends up comparing abstract methods that might have
1524 //been implemented by some concrete method in a subclass and,
1525 //because of raw override, it is possible for an abstract method
1526 //to be more specific than the concrete method - so we need
1527 //to explicitly call that out (see CR 6178365)
1528 bestSoFar = concrete;
1529 }
1530 }
1531 }
1532 return bestSoFar;
1533 }
1535 enum InterfaceLookupPhase {
1536 ABSTRACT_OK() {
1537 @Override
1538 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1539 //We should not look for abstract methods if receiver is a concrete class
1540 //(as concrete classes are expected to implement all abstracts coming
1541 //from superinterfaces)
1542 if ((s.flags() & (ABSTRACT | INTERFACE | ENUM)) != 0) {
1543 return this;
1544 } else if (rs.allowDefaultMethods) {
1545 return DEFAULT_OK;
1546 } else {
1547 return null;
1548 }
1549 }
1550 },
1551 DEFAULT_OK() {
1552 @Override
1553 InterfaceLookupPhase update(Symbol s, Resolve rs) {
1554 return this;
1555 }
1556 };
1558 abstract InterfaceLookupPhase update(Symbol s, Resolve rs);
1559 }
1561 /**
1562 * Return an Iterable object to scan the superclasses of a given type.
1563 * It's crucial that the scan is done lazily, as we don't want to accidentally
1564 * access more supertypes than strictly needed (as this could trigger completion
1565 * errors if some of the not-needed supertypes are missing/ill-formed).
1566 */
1567 Iterable<TypeSymbol> superclasses(final Type intype) {
1568 return new Iterable<TypeSymbol>() {
1569 public Iterator<TypeSymbol> iterator() {
1570 return new Iterator<TypeSymbol>() {
1572 List<TypeSymbol> seen = List.nil();
1573 TypeSymbol currentSym = symbolFor(intype);
1574 TypeSymbol prevSym = null;
1576 public boolean hasNext() {
1577 if (currentSym == syms.noSymbol) {
1578 currentSym = symbolFor(types.supertype(prevSym.type));
1579 }
1580 return currentSym != null;
1581 }
1583 public TypeSymbol next() {
1584 prevSym = currentSym;
1585 currentSym = syms.noSymbol;
1586 Assert.check(prevSym != null || prevSym != syms.noSymbol);
1587 return prevSym;
1588 }
1590 public void remove() {
1591 throw new UnsupportedOperationException();
1592 }
1594 TypeSymbol symbolFor(Type t) {
1595 if (!t.hasTag(CLASS) &&
1596 !t.hasTag(TYPEVAR)) {
1597 return null;
1598 }
1599 while (t.hasTag(TYPEVAR))
1600 t = t.getUpperBound();
1601 if (seen.contains(t.tsym)) {
1602 //degenerate case in which we have a circular
1603 //class hierarchy - because of ill-formed classfiles
1604 return null;
1605 }
1606 seen = seen.prepend(t.tsym);
1607 return t.tsym;
1608 }
1609 };
1610 }
1611 };
1612 }
1614 /** Find unqualified method matching given name, type and value arguments.
1615 * @param env The current environment.
1616 * @param name The method's name.
1617 * @param argtypes The method's value arguments.
1618 * @param typeargtypes The method's type arguments.
1619 * @param allowBoxing Allow boxing conversions of arguments.
1620 * @param useVarargs Box trailing arguments into an array for varargs.
1621 */
1622 Symbol findFun(Env<AttrContext> env, Name name,
1623 List<Type> argtypes, List<Type> typeargtypes,
1624 boolean allowBoxing, boolean useVarargs) {
1625 Symbol bestSoFar = methodNotFound;
1626 Symbol sym;
1627 Env<AttrContext> env1 = env;
1628 boolean staticOnly = false;
1629 while (env1.outer != null) {
1630 if (isStatic(env1)) staticOnly = true;
1631 sym = findMethod(
1632 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
1633 allowBoxing, useVarargs, false);
1634 if (sym.exists()) {
1635 if (staticOnly &&
1636 sym.kind == MTH &&
1637 sym.owner.kind == TYP &&
1638 (sym.flags() & STATIC) == 0) return new StaticError(sym);
1639 else return sym;
1640 } else if (sym.kind < bestSoFar.kind) {
1641 bestSoFar = sym;
1642 }
1643 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1644 env1 = env1.outer;
1645 }
1647 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1648 typeargtypes, allowBoxing, useVarargs, false);
1649 if (sym.exists())
1650 return sym;
1652 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1653 for (; e.scope != null; e = e.next()) {
1654 sym = e.sym;
1655 Type origin = e.getOrigin().owner.type;
1656 if (sym.kind == MTH) {
1657 if (e.sym.owner.type != origin)
1658 sym = sym.clone(e.getOrigin().owner);
1659 if (!isAccessible(env, origin, sym))
1660 sym = new AccessError(env, origin, sym);
1661 bestSoFar = selectBest(env, origin,
1662 argtypes, typeargtypes,
1663 sym, bestSoFar,
1664 allowBoxing, useVarargs, false);
1665 }
1666 }
1667 if (bestSoFar.exists())
1668 return bestSoFar;
1670 e = env.toplevel.starImportScope.lookup(name);
1671 for (; e.scope != null; e = e.next()) {
1672 sym = e.sym;
1673 Type origin = e.getOrigin().owner.type;
1674 if (sym.kind == MTH) {
1675 if (e.sym.owner.type != origin)
1676 sym = sym.clone(e.getOrigin().owner);
1677 if (!isAccessible(env, origin, sym))
1678 sym = new AccessError(env, origin, sym);
1679 bestSoFar = selectBest(env, origin,
1680 argtypes, typeargtypes,
1681 sym, bestSoFar,
1682 allowBoxing, useVarargs, false);
1683 }
1684 }
1685 return bestSoFar;
1686 }
1688 /** Load toplevel or member class with given fully qualified name and
1689 * verify that it is accessible.
1690 * @param env The current environment.
1691 * @param name The fully qualified name of the class to be loaded.
1692 */
1693 Symbol loadClass(Env<AttrContext> env, Name name) {
1694 try {
1695 ClassSymbol c = reader.loadClass(name);
1696 return isAccessible(env, c) ? c : new AccessError(c);
1697 } catch (ClassReader.BadClassFile err) {
1698 throw err;
1699 } catch (CompletionFailure ex) {
1700 return typeNotFound;
1701 }
1702 }
1704 /** Find qualified member type.
1705 * @param env The current environment.
1706 * @param site The original type from where the selection takes
1707 * place.
1708 * @param name The type's name.
1709 * @param c The class to search for the member type. This is
1710 * always a superclass or implemented interface of
1711 * site's class.
1712 */
1713 Symbol findMemberType(Env<AttrContext> env,
1714 Type site,
1715 Name name,
1716 TypeSymbol c) {
1717 Symbol bestSoFar = typeNotFound;
1718 Symbol sym;
1719 Scope.Entry e = c.members().lookup(name);
1720 while (e.scope != null) {
1721 if (e.sym.kind == TYP) {
1722 return isAccessible(env, site, e.sym)
1723 ? e.sym
1724 : new AccessError(env, site, e.sym);
1725 }
1726 e = e.next();
1727 }
1728 Type st = types.supertype(c.type);
1729 if (st != null && st.hasTag(CLASS)) {
1730 sym = findMemberType(env, site, name, st.tsym);
1731 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1732 }
1733 for (List<Type> l = types.interfaces(c.type);
1734 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1735 l = l.tail) {
1736 sym = findMemberType(env, site, name, l.head.tsym);
1737 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1738 sym.owner != bestSoFar.owner)
1739 bestSoFar = new AmbiguityError(bestSoFar, sym);
1740 else if (sym.kind < bestSoFar.kind)
1741 bestSoFar = sym;
1742 }
1743 return bestSoFar;
1744 }
1746 /** Find a global type in given scope and load corresponding class.
1747 * @param env The current environment.
1748 * @param scope The scope in which to look for the type.
1749 * @param name The type's name.
1750 */
1751 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
1752 Symbol bestSoFar = typeNotFound;
1753 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
1754 Symbol sym = loadClass(env, e.sym.flatName());
1755 if (bestSoFar.kind == TYP && sym.kind == TYP &&
1756 bestSoFar != sym)
1757 return new AmbiguityError(bestSoFar, sym);
1758 else if (sym.kind < bestSoFar.kind)
1759 bestSoFar = sym;
1760 }
1761 return bestSoFar;
1762 }
1764 /** Find an unqualified type symbol.
1765 * @param env The current environment.
1766 * @param name The type's name.
1767 */
1768 Symbol findType(Env<AttrContext> env, Name name) {
1769 Symbol bestSoFar = typeNotFound;
1770 Symbol sym;
1771 boolean staticOnly = false;
1772 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
1773 if (isStatic(env1)) staticOnly = true;
1774 for (Scope.Entry e = env1.info.scope.lookup(name);
1775 e.scope != null;
1776 e = e.next()) {
1777 if (e.sym.kind == TYP) {
1778 if (staticOnly &&
1779 e.sym.type.hasTag(TYPEVAR) &&
1780 e.sym.owner.kind == TYP) return new StaticError(e.sym);
1781 return e.sym;
1782 }
1783 }
1785 sym = findMemberType(env1, env1.enclClass.sym.type, name,
1786 env1.enclClass.sym);
1787 if (staticOnly && sym.kind == TYP &&
1788 sym.type.hasTag(CLASS) &&
1789 sym.type.getEnclosingType().hasTag(CLASS) &&
1790 env1.enclClass.sym.type.isParameterized() &&
1791 sym.type.getEnclosingType().isParameterized())
1792 return new StaticError(sym);
1793 else if (sym.exists()) return sym;
1794 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1796 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
1797 if ((encl.sym.flags() & STATIC) != 0)
1798 staticOnly = true;
1799 }
1801 if (!env.tree.hasTag(IMPORT)) {
1802 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
1803 if (sym.exists()) return sym;
1804 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1806 sym = findGlobalType(env, env.toplevel.packge.members(), name);
1807 if (sym.exists()) return sym;
1808 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1810 sym = findGlobalType(env, env.toplevel.starImportScope, name);
1811 if (sym.exists()) return sym;
1812 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1813 }
1815 return bestSoFar;
1816 }
1818 /** Find an unqualified identifier which matches a specified kind set.
1819 * @param env The current environment.
1820 * @param name The identifier's name.
1821 * @param kind Indicates the possible symbol kinds
1822 * (a subset of VAL, TYP, PCK).
1823 */
1824 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
1825 Symbol bestSoFar = typeNotFound;
1826 Symbol sym;
1828 if ((kind & VAR) != 0) {
1829 sym = findVar(env, name);
1830 if (sym.exists()) return sym;
1831 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1832 }
1834 if ((kind & TYP) != 0) {
1835 sym = findType(env, name);
1836 if (sym.kind==TYP) {
1837 reportDependence(env.enclClass.sym, sym);
1838 }
1839 if (sym.exists()) return sym;
1840 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1841 }
1843 if ((kind & PCK) != 0) return reader.enterPackage(name);
1844 else return bestSoFar;
1845 }
1847 /** Report dependencies.
1848 * @param from The enclosing class sym
1849 * @param to The found identifier that the class depends on.
1850 */
1851 public void reportDependence(Symbol from, Symbol to) {
1852 // Override if you want to collect the reported dependencies.
1853 }
1855 /** Find an identifier in a package which matches a specified kind set.
1856 * @param env The current environment.
1857 * @param name The identifier's name.
1858 * @param kind Indicates the possible symbol kinds
1859 * (a nonempty subset of TYP, PCK).
1860 */
1861 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1862 Name name, int kind) {
1863 Name fullname = TypeSymbol.formFullName(name, pck);
1864 Symbol bestSoFar = typeNotFound;
1865 PackageSymbol pack = null;
1866 if ((kind & PCK) != 0) {
1867 pack = reader.enterPackage(fullname);
1868 if (pack.exists()) return pack;
1869 }
1870 if ((kind & TYP) != 0) {
1871 Symbol sym = loadClass(env, fullname);
1872 if (sym.exists()) {
1873 // don't allow programs to use flatnames
1874 if (name == sym.name) return sym;
1875 }
1876 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1877 }
1878 return (pack != null) ? pack : bestSoFar;
1879 }
1881 /** Find an identifier among the members of a given type `site'.
1882 * @param env The current environment.
1883 * @param site The type containing the symbol to be found.
1884 * @param name The identifier's name.
1885 * @param kind Indicates the possible symbol kinds
1886 * (a subset of VAL, TYP).
1887 */
1888 Symbol findIdentInType(Env<AttrContext> env, Type site,
1889 Name name, int kind) {
1890 Symbol bestSoFar = typeNotFound;
1891 Symbol sym;
1892 if ((kind & VAR) != 0) {
1893 sym = findField(env, site, name, site.tsym);
1894 if (sym.exists()) return sym;
1895 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1896 }
1898 if ((kind & TYP) != 0) {
1899 sym = findMemberType(env, site, name, site.tsym);
1900 if (sym.exists()) return sym;
1901 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1902 }
1903 return bestSoFar;
1904 }
1906 /* ***************************************************************************
1907 * Access checking
1908 * The following methods convert ResolveErrors to ErrorSymbols, issuing
1909 * an error message in the process
1910 ****************************************************************************/
1912 /** If `sym' is a bad symbol: report error and return errSymbol
1913 * else pass through unchanged,
1914 * additional arguments duplicate what has been used in trying to find the
1915 * symbol {@literal (--> flyweight pattern)}. This improves performance since we
1916 * expect misses to happen frequently.
1917 *
1918 * @param sym The symbol that was found, or a ResolveError.
1919 * @param pos The position to use for error reporting.
1920 * @param location The symbol the served as a context for this lookup
1921 * @param site The original type from where the selection took place.
1922 * @param name The symbol's name.
1923 * @param qualified Did we get here through a qualified expression resolution?
1924 * @param argtypes The invocation's value arguments,
1925 * if we looked for a method.
1926 * @param typeargtypes The invocation's type arguments,
1927 * if we looked for a method.
1928 * @param logResolveHelper helper class used to log resolve errors
1929 */
1930 Symbol accessInternal(Symbol sym,
1931 DiagnosticPosition pos,
1932 Symbol location,
1933 Type site,
1934 Name name,
1935 boolean qualified,
1936 List<Type> argtypes,
1937 List<Type> typeargtypes,
1938 LogResolveHelper logResolveHelper) {
1939 if (sym.kind >= AMBIGUOUS) {
1940 ResolveError errSym = (ResolveError)sym;
1941 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
1942 argtypes = logResolveHelper.getArgumentTypes(errSym, sym, name, argtypes);
1943 if (logResolveHelper.resolveDiagnosticNeeded(site, argtypes, typeargtypes)) {
1944 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
1945 }
1946 }
1947 return sym;
1948 }
1950 /**
1951 * Variant of the generalized access routine, to be used for generating method
1952 * resolution diagnostics
1953 */
1954 Symbol accessMethod(Symbol sym,
1955 DiagnosticPosition pos,
1956 Symbol location,
1957 Type site,
1958 Name name,
1959 boolean qualified,
1960 List<Type> argtypes,
1961 List<Type> typeargtypes) {
1962 return accessInternal(sym, pos, location, site, name, qualified, argtypes, typeargtypes, methodLogResolveHelper);
1963 }
1965 /** Same as original accessMethod(), but without location.
1966 */
1967 Symbol accessMethod(Symbol sym,
1968 DiagnosticPosition pos,
1969 Type site,
1970 Name name,
1971 boolean qualified,
1972 List<Type> argtypes,
1973 List<Type> typeargtypes) {
1974 return accessMethod(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
1975 }
1977 /**
1978 * Variant of the generalized access routine, to be used for generating variable,
1979 * type resolution diagnostics
1980 */
1981 Symbol accessBase(Symbol sym,
1982 DiagnosticPosition pos,
1983 Symbol location,
1984 Type site,
1985 Name name,
1986 boolean qualified) {
1987 return accessInternal(sym, pos, location, site, name, qualified, List.<Type>nil(), null, basicLogResolveHelper);
1988 }
1990 /** Same as original accessBase(), but without location.
1991 */
1992 Symbol accessBase(Symbol sym,
1993 DiagnosticPosition pos,
1994 Type site,
1995 Name name,
1996 boolean qualified) {
1997 return accessBase(sym, pos, site.tsym, site, name, qualified);
1998 }
2000 interface LogResolveHelper {
2001 boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes);
2002 List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes);
2003 }
2005 LogResolveHelper basicLogResolveHelper = new LogResolveHelper() {
2006 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2007 return !site.isErroneous();
2008 }
2009 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2010 return argtypes;
2011 }
2012 };
2014 LogResolveHelper methodLogResolveHelper = new LogResolveHelper() {
2015 public boolean resolveDiagnosticNeeded(Type site, List<Type> argtypes, List<Type> typeargtypes) {
2016 return !site.isErroneous() &&
2017 !Type.isErroneous(argtypes) &&
2018 (typeargtypes == null || !Type.isErroneous(typeargtypes));
2019 }
2020 public List<Type> getArgumentTypes(ResolveError errSym, Symbol accessedSym, Name name, List<Type> argtypes) {
2021 return (syms.operatorNames.contains(name)) ?
2022 argtypes :
2023 Type.map(argtypes, new ResolveDeferredRecoveryMap(accessedSym));
2024 }
2026 class ResolveDeferredRecoveryMap extends DeferredAttr.RecoveryDeferredTypeMap {
2028 public ResolveDeferredRecoveryMap(Symbol msym) {
2029 deferredAttr.super(AttrMode.SPECULATIVE, msym, currentResolutionContext.step);
2030 }
2032 @Override
2033 protected Type typeOf(DeferredType dt) {
2034 Type res = super.typeOf(dt);
2035 if (!res.isErroneous()) {
2036 switch (TreeInfo.skipParens(dt.tree).getTag()) {
2037 case LAMBDA:
2038 case REFERENCE:
2039 return dt;
2040 case CONDEXPR:
2041 return res == Type.recoveryType ?
2042 dt : res;
2043 }
2044 }
2045 return res;
2046 }
2047 }
2048 };
2050 /** Check that sym is not an abstract method.
2051 */
2052 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
2053 if ((sym.flags() & ABSTRACT) != 0 && (sym.flags() & DEFAULT) == 0)
2054 log.error(pos, "abstract.cant.be.accessed.directly",
2055 kindName(sym), sym, sym.location());
2056 }
2058 /* ***************************************************************************
2059 * Debugging
2060 ****************************************************************************/
2062 /** print all scopes starting with scope s and proceeding outwards.
2063 * used for debugging.
2064 */
2065 public void printscopes(Scope s) {
2066 while (s != null) {
2067 if (s.owner != null)
2068 System.err.print(s.owner + ": ");
2069 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
2070 if ((e.sym.flags() & ABSTRACT) != 0)
2071 System.err.print("abstract ");
2072 System.err.print(e.sym + " ");
2073 }
2074 System.err.println();
2075 s = s.next;
2076 }
2077 }
2079 void printscopes(Env<AttrContext> env) {
2080 while (env.outer != null) {
2081 System.err.println("------------------------------");
2082 printscopes(env.info.scope);
2083 env = env.outer;
2084 }
2085 }
2087 public void printscopes(Type t) {
2088 while (t.hasTag(CLASS)) {
2089 printscopes(t.tsym.members());
2090 t = types.supertype(t);
2091 }
2092 }
2094 /* ***************************************************************************
2095 * Name resolution
2096 * Naming conventions are as for symbol lookup
2097 * Unlike the find... methods these methods will report access errors
2098 ****************************************************************************/
2100 /** Resolve an unqualified (non-method) identifier.
2101 * @param pos The position to use for error reporting.
2102 * @param env The environment current at the identifier use.
2103 * @param name The identifier's name.
2104 * @param kind The set of admissible symbol kinds for the identifier.
2105 */
2106 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
2107 Name name, int kind) {
2108 return accessBase(
2109 findIdent(env, name, kind),
2110 pos, env.enclClass.sym.type, name, false);
2111 }
2113 /** Resolve an unqualified method identifier.
2114 * @param pos The position to use for error reporting.
2115 * @param env The environment current at the method invocation.
2116 * @param name The identifier's name.
2117 * @param argtypes The types of the invocation's value arguments.
2118 * @param typeargtypes The types of the invocation's type arguments.
2119 */
2120 Symbol resolveMethod(DiagnosticPosition pos,
2121 Env<AttrContext> env,
2122 Name name,
2123 List<Type> argtypes,
2124 List<Type> typeargtypes) {
2125 return lookupMethod(env, pos, env.enclClass.sym, new BasicLookupHelper(name, env.enclClass.sym.type, argtypes, typeargtypes) {
2126 @Override
2127 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2128 return findFun(env, name, argtypes, typeargtypes,
2129 phase.isBoxingRequired(),
2130 phase.isVarargsRequired());
2131 }
2132 });
2133 }
2135 /** Resolve a qualified method identifier
2136 * @param pos The position to use for error reporting.
2137 * @param env The environment current at the method invocation.
2138 * @param site The type of the qualifying expression, in which
2139 * identifier is searched.
2140 * @param name The identifier's name.
2141 * @param argtypes The types of the invocation's value arguments.
2142 * @param typeargtypes The types of the invocation's type arguments.
2143 */
2144 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2145 Type site, Name name, List<Type> argtypes,
2146 List<Type> typeargtypes) {
2147 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
2148 }
2149 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
2150 Symbol location, Type site, Name name, List<Type> argtypes,
2151 List<Type> typeargtypes) {
2152 return resolveQualifiedMethod(new MethodResolutionContext(), pos, env, location, site, name, argtypes, typeargtypes);
2153 }
2154 private Symbol resolveQualifiedMethod(MethodResolutionContext resolveContext,
2155 DiagnosticPosition pos, Env<AttrContext> env,
2156 Symbol location, Type site, Name name, List<Type> argtypes,
2157 List<Type> typeargtypes) {
2158 return lookupMethod(env, pos, location, resolveContext, new BasicLookupHelper(name, site, argtypes, typeargtypes) {
2159 @Override
2160 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2161 return findMethod(env, site, name, argtypes, typeargtypes,
2162 phase.isBoxingRequired(),
2163 phase.isVarargsRequired(), false);
2164 }
2165 @Override
2166 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2167 if (sym.kind >= AMBIGUOUS) {
2168 sym = super.access(env, pos, location, sym);
2169 } else if (allowMethodHandles) {
2170 MethodSymbol msym = (MethodSymbol)sym;
2171 if (msym.isSignaturePolymorphic(types)) {
2172 return findPolymorphicSignatureInstance(env, sym, argtypes);
2173 }
2174 }
2175 return sym;
2176 }
2177 });
2178 }
2180 /** Find or create an implicit method of exactly the given type (after erasure).
2181 * Searches in a side table, not the main scope of the site.
2182 * This emulates the lookup process required by JSR 292 in JVM.
2183 * @param env Attribution environment
2184 * @param spMethod signature polymorphic method - i.e. MH.invokeExact
2185 * @param argtypes The required argument types
2186 */
2187 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env,
2188 final Symbol spMethod,
2189 List<Type> argtypes) {
2190 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
2191 (MethodSymbol)spMethod, currentResolutionContext, argtypes);
2192 for (Symbol sym : polymorphicSignatureScope.getElementsByName(spMethod.name)) {
2193 if (types.isSameType(mtype, sym.type)) {
2194 return sym;
2195 }
2196 }
2198 // create the desired method
2199 long flags = ABSTRACT | HYPOTHETICAL | spMethod.flags() & Flags.AccessFlags;
2200 Symbol msym = new MethodSymbol(flags, spMethod.name, mtype, spMethod.owner) {
2201 @Override
2202 public Symbol baseSymbol() {
2203 return spMethod;
2204 }
2205 };
2206 polymorphicSignatureScope.enter(msym);
2207 return msym;
2208 }
2210 /** Resolve a qualified method identifier, throw a fatal error if not
2211 * found.
2212 * @param pos The position to use for error reporting.
2213 * @param env The environment current at the method invocation.
2214 * @param site The type of the qualifying expression, in which
2215 * identifier is searched.
2216 * @param name The identifier's name.
2217 * @param argtypes The types of the invocation's value arguments.
2218 * @param typeargtypes The types of the invocation's type arguments.
2219 */
2220 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
2221 Type site, Name name,
2222 List<Type> argtypes,
2223 List<Type> typeargtypes) {
2224 MethodResolutionContext resolveContext = new MethodResolutionContext();
2225 resolveContext.internalResolution = true;
2226 Symbol sym = resolveQualifiedMethod(resolveContext, pos, env, site.tsym,
2227 site, name, argtypes, typeargtypes);
2228 if (sym.kind == MTH) return (MethodSymbol)sym;
2229 else throw new FatalError(
2230 diags.fragment("fatal.err.cant.locate.meth",
2231 name));
2232 }
2234 /** Resolve constructor.
2235 * @param pos The position to use for error reporting.
2236 * @param env The environment current at the constructor invocation.
2237 * @param site The type of class for which a constructor is searched.
2238 * @param argtypes The types of the constructor invocation's value
2239 * arguments.
2240 * @param typeargtypes The types of the constructor invocation's type
2241 * arguments.
2242 */
2243 Symbol resolveConstructor(DiagnosticPosition pos,
2244 Env<AttrContext> env,
2245 Type site,
2246 List<Type> argtypes,
2247 List<Type> typeargtypes) {
2248 return resolveConstructor(new MethodResolutionContext(), pos, env, site, argtypes, typeargtypes);
2249 }
2251 private Symbol resolveConstructor(MethodResolutionContext resolveContext,
2252 final DiagnosticPosition pos,
2253 Env<AttrContext> env,
2254 Type site,
2255 List<Type> argtypes,
2256 List<Type> typeargtypes) {
2257 return lookupMethod(env, pos, site.tsym, resolveContext, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2258 @Override
2259 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2260 return findConstructor(pos, env, site, argtypes, typeargtypes,
2261 phase.isBoxingRequired(),
2262 phase.isVarargsRequired());
2263 }
2264 });
2265 }
2267 /** Resolve a constructor, throw a fatal error if not found.
2268 * @param pos The position to use for error reporting.
2269 * @param env The environment current at the method invocation.
2270 * @param site The type to be constructed.
2271 * @param argtypes The types of the invocation's value arguments.
2272 * @param typeargtypes The types of the invocation's type arguments.
2273 */
2274 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2275 Type site,
2276 List<Type> argtypes,
2277 List<Type> typeargtypes) {
2278 MethodResolutionContext resolveContext = new MethodResolutionContext();
2279 resolveContext.internalResolution = true;
2280 Symbol sym = resolveConstructor(resolveContext, pos, env, site, argtypes, typeargtypes);
2281 if (sym.kind == MTH) return (MethodSymbol)sym;
2282 else throw new FatalError(
2283 diags.fragment("fatal.err.cant.locate.ctor", site));
2284 }
2286 Symbol findConstructor(DiagnosticPosition pos, Env<AttrContext> env,
2287 Type site, List<Type> argtypes,
2288 List<Type> typeargtypes,
2289 boolean allowBoxing,
2290 boolean useVarargs) {
2291 Symbol sym = findMethod(env, site,
2292 names.init, argtypes,
2293 typeargtypes, allowBoxing,
2294 useVarargs, false);
2295 chk.checkDeprecated(pos, env.info.scope.owner, sym);
2296 return sym;
2297 }
2299 /** Resolve constructor using diamond inference.
2300 * @param pos The position to use for error reporting.
2301 * @param env The environment current at the constructor invocation.
2302 * @param site The type of class for which a constructor is searched.
2303 * The scope of this class has been touched in attribution.
2304 * @param argtypes The types of the constructor invocation's value
2305 * arguments.
2306 * @param typeargtypes The types of the constructor invocation's type
2307 * arguments.
2308 */
2309 Symbol resolveDiamond(DiagnosticPosition pos,
2310 Env<AttrContext> env,
2311 Type site,
2312 List<Type> argtypes,
2313 List<Type> typeargtypes) {
2314 return lookupMethod(env, pos, site.tsym, new BasicLookupHelper(names.init, site, argtypes, typeargtypes) {
2315 @Override
2316 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2317 return findDiamond(env, site, argtypes, typeargtypes,
2318 phase.isBoxingRequired(),
2319 phase.isVarargsRequired());
2320 }
2321 @Override
2322 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2323 if (sym.kind >= AMBIGUOUS) {
2324 final JCDiagnostic details = sym.kind == WRONG_MTH ?
2325 ((InapplicableSymbolError)sym).errCandidate().details :
2326 null;
2327 sym = new InapplicableSymbolError(sym.kind, "diamondError", currentResolutionContext) {
2328 @Override
2329 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
2330 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2331 String key = details == null ?
2332 "cant.apply.diamond" :
2333 "cant.apply.diamond.1";
2334 return diags.create(dkind, log.currentSource(), pos, key,
2335 diags.fragment("diamond", site.tsym), details);
2336 }
2337 };
2338 sym = accessMethod(sym, pos, site, names.init, true, argtypes, typeargtypes);
2339 env.info.pendingResolutionPhase = currentResolutionContext.step;
2340 }
2341 return sym;
2342 }
2343 });
2344 }
2346 /** This method scans all the constructor symbol in a given class scope -
2347 * assuming that the original scope contains a constructor of the kind:
2348 * {@code Foo(X x, Y y)}, where X,Y are class type-variables declared in Foo,
2349 * a method check is executed against the modified constructor type:
2350 * {@code <X,Y>Foo<X,Y>(X x, Y y)}. This is crucial in order to enable diamond
2351 * inference. The inferred return type of the synthetic constructor IS
2352 * the inferred type for the diamond operator.
2353 */
2354 private Symbol findDiamond(Env<AttrContext> env,
2355 Type site,
2356 List<Type> argtypes,
2357 List<Type> typeargtypes,
2358 boolean allowBoxing,
2359 boolean useVarargs) {
2360 Symbol bestSoFar = methodNotFound;
2361 for (Scope.Entry e = site.tsym.members().lookup(names.init);
2362 e.scope != null;
2363 e = e.next()) {
2364 final Symbol sym = e.sym;
2365 //- System.out.println(" e " + e.sym);
2366 if (sym.kind == MTH &&
2367 (sym.flags_field & SYNTHETIC) == 0) {
2368 List<Type> oldParams = e.sym.type.hasTag(FORALL) ?
2369 ((ForAll)sym.type).tvars :
2370 List.<Type>nil();
2371 Type constrType = new ForAll(site.tsym.type.getTypeArguments().appendList(oldParams),
2372 types.createMethodTypeWithReturn(sym.type.asMethodType(), site));
2373 MethodSymbol newConstr = new MethodSymbol(sym.flags(), names.init, constrType, site.tsym) {
2374 @Override
2375 public Symbol baseSymbol() {
2376 return sym;
2377 }
2378 };
2379 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
2380 newConstr,
2381 bestSoFar,
2382 allowBoxing,
2383 useVarargs,
2384 false);
2385 }
2386 }
2387 return bestSoFar;
2388 }
2392 /** Resolve operator.
2393 * @param pos The position to use for error reporting.
2394 * @param optag The tag of the operation tree.
2395 * @param env The environment current at the operation.
2396 * @param argtypes The types of the operands.
2397 */
2398 Symbol resolveOperator(DiagnosticPosition pos, JCTree.Tag optag,
2399 Env<AttrContext> env, List<Type> argtypes) {
2400 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2401 try {
2402 currentResolutionContext = new MethodResolutionContext();
2403 Name name = treeinfo.operatorName(optag);
2404 env.info.pendingResolutionPhase = currentResolutionContext.step = BASIC;
2405 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
2406 null, false, false, true);
2407 if (boxingEnabled && sym.kind >= WRONG_MTHS)
2408 env.info.pendingResolutionPhase = currentResolutionContext.step = BOX;
2409 sym = findMethod(env, syms.predefClass.type, name, argtypes,
2410 null, true, false, true);
2411 return accessMethod(sym, pos, env.enclClass.sym.type, name,
2412 false, argtypes, null);
2413 }
2414 finally {
2415 currentResolutionContext = prevResolutionContext;
2416 }
2417 }
2419 /** Resolve operator.
2420 * @param pos The position to use for error reporting.
2421 * @param optag The tag of the operation tree.
2422 * @param env The environment current at the operation.
2423 * @param arg The type of the operand.
2424 */
2425 Symbol resolveUnaryOperator(DiagnosticPosition pos, JCTree.Tag optag, Env<AttrContext> env, Type arg) {
2426 return resolveOperator(pos, optag, env, List.of(arg));
2427 }
2429 /** Resolve binary operator.
2430 * @param pos The position to use for error reporting.
2431 * @param optag The tag of the operation tree.
2432 * @param env The environment current at the operation.
2433 * @param left The types of the left operand.
2434 * @param right The types of the right operand.
2435 */
2436 Symbol resolveBinaryOperator(DiagnosticPosition pos,
2437 JCTree.Tag optag,
2438 Env<AttrContext> env,
2439 Type left,
2440 Type right) {
2441 return resolveOperator(pos, optag, env, List.of(left, right));
2442 }
2444 /**
2445 * Resolution of member references is typically done as a single
2446 * overload resolution step, where the argument types A are inferred from
2447 * the target functional descriptor.
2448 *
2449 * If the member reference is a method reference with a type qualifier,
2450 * a two-step lookup process is performed. The first step uses the
2451 * expected argument list A, while the second step discards the first
2452 * type from A (which is treated as a receiver type).
2453 *
2454 * There are two cases in which inference is performed: (i) if the member
2455 * reference is a constructor reference and the qualifier type is raw - in
2456 * which case diamond inference is used to infer a parameterization for the
2457 * type qualifier; (ii) if the member reference is an unbound reference
2458 * where the type qualifier is raw - in that case, during the unbound lookup
2459 * the receiver argument type is used to infer an instantiation for the raw
2460 * qualifier type.
2461 *
2462 * When a multi-step resolution process is exploited, it is an error
2463 * if two candidates are found (ambiguity).
2464 *
2465 * This routine returns a pair (T,S), where S is the member reference symbol,
2466 * and T is the type of the class in which S is defined. This is necessary as
2467 * the type T might be dynamically inferred (i.e. if constructor reference
2468 * has a raw qualifier).
2469 */
2470 Pair<Symbol, ReferenceLookupHelper> resolveMemberReference(DiagnosticPosition pos,
2471 Env<AttrContext> env,
2472 JCMemberReference referenceTree,
2473 Type site,
2474 Name name, List<Type> argtypes,
2475 List<Type> typeargtypes,
2476 boolean boxingAllowed) {
2477 MethodResolutionPhase maxPhase = boxingAllowed ? VARARITY : BASIC;
2479 ReferenceLookupHelper boundLookupHelper;
2480 if (!name.equals(names.init)) {
2481 //method reference
2482 boundLookupHelper =
2483 new MethodReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2484 } else if (site.hasTag(ARRAY)) {
2485 //array constructor reference
2486 boundLookupHelper =
2487 new ArrayConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2488 } else {
2489 //class constructor reference
2490 boundLookupHelper =
2491 new ConstructorReferenceLookupHelper(referenceTree, site, argtypes, typeargtypes, maxPhase);
2492 }
2494 //step 1 - bound lookup
2495 Env<AttrContext> boundEnv = env.dup(env.tree, env.info.dup());
2496 Symbol boundSym = lookupMethod(boundEnv, env.tree.pos(), site.tsym, boundLookupHelper);
2498 //step 2 - unbound lookup
2499 ReferenceLookupHelper unboundLookupHelper = boundLookupHelper.unboundLookup();
2500 Env<AttrContext> unboundEnv = env.dup(env.tree, env.info.dup());
2501 Symbol unboundSym = lookupMethod(unboundEnv, env.tree.pos(), site.tsym, unboundLookupHelper);
2503 //merge results
2504 Pair<Symbol, ReferenceLookupHelper> res;
2505 if (unboundSym.kind != MTH) {
2506 res = new Pair<Symbol, ReferenceLookupHelper>(boundSym, boundLookupHelper);
2507 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2508 } else if (boundSym.kind == MTH) {
2509 res = new Pair<Symbol, ReferenceLookupHelper>(ambiguityError(boundSym, unboundSym), boundLookupHelper);
2510 env.info.pendingResolutionPhase = boundEnv.info.pendingResolutionPhase;
2511 } else {
2512 res = new Pair<Symbol, ReferenceLookupHelper>(unboundSym, unboundLookupHelper);
2513 env.info.pendingResolutionPhase = unboundEnv.info.pendingResolutionPhase;
2514 }
2516 return res;
2517 }
2519 /**
2520 * Helper for defining custom method-like lookup logic; a lookup helper
2521 * provides hooks for (i) the actual lookup logic and (ii) accessing the
2522 * lookup result (this step might result in compiler diagnostics to be generated)
2523 */
2524 abstract class LookupHelper {
2526 /** name of the symbol to lookup */
2527 Name name;
2529 /** location in which the lookup takes place */
2530 Type site;
2532 /** actual types used during the lookup */
2533 List<Type> argtypes;
2535 /** type arguments used during the lookup */
2536 List<Type> typeargtypes;
2538 /** Max overload resolution phase handled by this helper */
2539 MethodResolutionPhase maxPhase;
2541 LookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2542 this.name = name;
2543 this.site = site;
2544 this.argtypes = argtypes;
2545 this.typeargtypes = typeargtypes;
2546 this.maxPhase = maxPhase;
2547 }
2549 /**
2550 * Should lookup stop at given phase with given result
2551 */
2552 protected boolean shouldStop(Symbol sym, MethodResolutionPhase phase) {
2553 return phase.ordinal() > maxPhase.ordinal() ||
2554 sym.kind < ERRONEOUS || sym.kind == AMBIGUOUS;
2555 }
2557 /**
2558 * Search for a symbol under a given overload resolution phase - this method
2559 * is usually called several times, once per each overload resolution phase
2560 */
2561 abstract Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase);
2563 /**
2564 * Validate the result of the lookup
2565 */
2566 abstract Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym);
2567 }
2569 abstract class BasicLookupHelper extends LookupHelper {
2571 BasicLookupHelper(Name name, Type site, List<Type> argtypes, List<Type> typeargtypes) {
2572 super(name, site, argtypes, typeargtypes, MethodResolutionPhase.VARARITY);
2573 }
2575 @Override
2576 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2577 if (sym.kind == AMBIGUOUS) {
2578 AmbiguityError a_err = (AmbiguityError)sym;
2579 sym = a_err.mergeAbstracts(site);
2580 }
2581 if (sym.kind >= AMBIGUOUS) {
2582 //if nothing is found return the 'first' error
2583 sym = accessMethod(sym, pos, location, site, name, true, argtypes, typeargtypes);
2584 }
2585 return sym;
2586 }
2587 }
2589 /**
2590 * Helper class for member reference lookup. A reference lookup helper
2591 * defines the basic logic for member reference lookup; a method gives
2592 * access to an 'unbound' helper used to perform an unbound member
2593 * reference lookup.
2594 */
2595 abstract class ReferenceLookupHelper extends LookupHelper {
2597 /** The member reference tree */
2598 JCMemberReference referenceTree;
2600 ReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2601 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2602 super(name, site, argtypes, typeargtypes, maxPhase);
2603 this.referenceTree = referenceTree;
2605 }
2607 /**
2608 * Returns an unbound version of this lookup helper. By default, this
2609 * method returns an dummy lookup helper.
2610 */
2611 ReferenceLookupHelper unboundLookup() {
2612 //dummy loopkup helper that always return 'methodNotFound'
2613 return new ReferenceLookupHelper(referenceTree, name, site, argtypes, typeargtypes, maxPhase) {
2614 @Override
2615 ReferenceLookupHelper unboundLookup() {
2616 return this;
2617 }
2618 @Override
2619 Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2620 return methodNotFound;
2621 }
2622 @Override
2623 ReferenceKind referenceKind(Symbol sym) {
2624 Assert.error();
2625 return null;
2626 }
2627 };
2628 }
2630 /**
2631 * Get the kind of the member reference
2632 */
2633 abstract JCMemberReference.ReferenceKind referenceKind(Symbol sym);
2635 Symbol access(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, Symbol sym) {
2636 if (sym.kind == AMBIGUOUS) {
2637 AmbiguityError a_err = (AmbiguityError)sym;
2638 sym = a_err.mergeAbstracts(site);
2639 }
2640 //skip error reporting
2641 return sym;
2642 }
2643 }
2645 /**
2646 * Helper class for method reference lookup. The lookup logic is based
2647 * upon Resolve.findMethod; in certain cases, this helper class has a
2648 * corresponding unbound helper class (see UnboundMethodReferenceLookupHelper).
2649 * In such cases, non-static lookup results are thrown away.
2650 */
2651 class MethodReferenceLookupHelper extends ReferenceLookupHelper {
2653 MethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2654 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2655 super(referenceTree, name, site, argtypes, typeargtypes, maxPhase);
2656 }
2658 protected Symbol lookupReferenceInternal(Env<AttrContext> env, MethodResolutionPhase phase) {
2659 return findMethod(env, site, name, argtypes, typeargtypes,
2660 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2661 }
2663 protected Symbol adjustLookupResult(Env<AttrContext> env, Symbol sym) {
2664 return !TreeInfo.isStaticSelector(referenceTree.expr, names) ||
2665 sym.kind != MTH ||
2666 sym.isStatic() ? sym : new StaticError(sym);
2667 }
2669 @Override
2670 final Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2671 return adjustLookupResult(env, lookupReferenceInternal(env, phase));
2672 }
2674 @Override
2675 ReferenceLookupHelper unboundLookup() {
2676 if (TreeInfo.isStaticSelector(referenceTree.expr, names) &&
2677 argtypes.nonEmpty() &&
2678 types.isSubtypeUnchecked(argtypes.head, site)) {
2679 return new UnboundMethodReferenceLookupHelper(referenceTree, name,
2680 site, argtypes, typeargtypes, maxPhase);
2681 } else {
2682 return super.unboundLookup();
2683 }
2684 }
2686 @Override
2687 ReferenceKind referenceKind(Symbol sym) {
2688 if (sym.isStatic()) {
2689 return ReferenceKind.STATIC;
2690 } else {
2691 Name selName = TreeInfo.name(referenceTree.getQualifierExpression());
2692 return selName != null && selName == names._super ?
2693 ReferenceKind.SUPER :
2694 ReferenceKind.BOUND;
2695 }
2696 }
2697 }
2699 /**
2700 * Helper class for unbound method reference lookup. Essentially the same
2701 * as the basic method reference lookup helper; main difference is that static
2702 * lookup results are thrown away. If qualifier type is raw, an attempt to
2703 * infer a parameterized type is made using the first actual argument (that
2704 * would otherwise be ignored during the lookup).
2705 */
2706 class UnboundMethodReferenceLookupHelper extends MethodReferenceLookupHelper {
2708 UnboundMethodReferenceLookupHelper(JCMemberReference referenceTree, Name name, Type site,
2709 List<Type> argtypes, List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2710 super(referenceTree, name,
2711 site.isRaw() ? types.asSuper(argtypes.head, site.tsym) : site,
2712 argtypes.tail, typeargtypes, maxPhase);
2713 }
2715 @Override
2716 protected Symbol adjustLookupResult(Env<AttrContext> env, Symbol sym) {
2717 return sym.kind != MTH || !sym.isStatic() ? sym : new StaticError(sym);
2718 }
2720 @Override
2721 ReferenceLookupHelper unboundLookup() {
2722 return this;
2723 }
2725 @Override
2726 ReferenceKind referenceKind(Symbol sym) {
2727 return ReferenceKind.UNBOUND;
2728 }
2729 }
2731 /**
2732 * Helper class for array constructor lookup; an array constructor lookup
2733 * is simulated by looking up a method that returns the array type specified
2734 * as qualifier, and that accepts a single int parameter (size of the array).
2735 */
2736 class ArrayConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2738 ArrayConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2739 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2740 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2741 }
2743 @Override
2744 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2745 Scope sc = new Scope(syms.arrayClass);
2746 MethodSymbol arrayConstr = new MethodSymbol(PUBLIC, name, null, site.tsym);
2747 arrayConstr.type = new MethodType(List.of(syms.intType), site, List.<Type>nil(), syms.methodClass);
2748 sc.enter(arrayConstr);
2749 return findMethodInScope(env, site, name, argtypes, typeargtypes, sc, methodNotFound, phase.isBoxingRequired(), phase.isVarargsRequired(), false, false);
2750 }
2752 @Override
2753 ReferenceKind referenceKind(Symbol sym) {
2754 return ReferenceKind.ARRAY_CTOR;
2755 }
2756 }
2758 /**
2759 * Helper class for constructor reference lookup. The lookup logic is based
2760 * upon either Resolve.findMethod or Resolve.findDiamond - depending on
2761 * whether the constructor reference needs diamond inference (this is the case
2762 * if the qualifier type is raw). A special erroneous symbol is returned
2763 * if the lookup returns the constructor of an inner class and there's no
2764 * enclosing instance in scope.
2765 */
2766 class ConstructorReferenceLookupHelper extends ReferenceLookupHelper {
2768 boolean needsInference;
2770 ConstructorReferenceLookupHelper(JCMemberReference referenceTree, Type site, List<Type> argtypes,
2771 List<Type> typeargtypes, MethodResolutionPhase maxPhase) {
2772 super(referenceTree, names.init, site, argtypes, typeargtypes, maxPhase);
2773 if (site.isRaw()) {
2774 this.site = new ClassType(site.getEnclosingType(), site.tsym.type.getTypeArguments(), site.tsym);
2775 needsInference = true;
2776 }
2777 }
2779 @Override
2780 protected Symbol lookup(Env<AttrContext> env, MethodResolutionPhase phase) {
2781 Symbol sym = needsInference ?
2782 findDiamond(env, site, argtypes, typeargtypes, phase.isBoxingRequired(), phase.isVarargsRequired()) :
2783 findMethod(env, site, name, argtypes, typeargtypes,
2784 phase.isBoxingRequired(), phase.isVarargsRequired(), syms.operatorNames.contains(name));
2785 return sym.kind != MTH ||
2786 site.getEnclosingType().hasTag(NONE) ||
2787 hasEnclosingInstance(env, site) ?
2788 sym : new InvalidSymbolError(Kinds.MISSING_ENCL, sym, null) {
2789 @Override
2790 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos, Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
2791 return diags.create(dkind, log.currentSource(), pos,
2792 "cant.access.inner.cls.constr", site.tsym.name, argtypes, site.getEnclosingType());
2793 }
2794 };
2795 }
2797 @Override
2798 ReferenceKind referenceKind(Symbol sym) {
2799 return site.getEnclosingType().hasTag(NONE) ?
2800 ReferenceKind.TOPLEVEL : ReferenceKind.IMPLICIT_INNER;
2801 }
2802 }
2804 /**
2805 * Main overload resolution routine. On each overload resolution step, a
2806 * lookup helper class is used to perform the method/constructor lookup;
2807 * at the end of the lookup, the helper is used to validate the results
2808 * (this last step might trigger overload resolution diagnostics).
2809 */
2810 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location, LookupHelper lookupHelper) {
2811 return lookupMethod(env, pos, location, new MethodResolutionContext(), lookupHelper);
2812 }
2814 Symbol lookupMethod(Env<AttrContext> env, DiagnosticPosition pos, Symbol location,
2815 MethodResolutionContext resolveContext, LookupHelper lookupHelper) {
2816 MethodResolutionContext prevResolutionContext = currentResolutionContext;
2817 try {
2818 Symbol bestSoFar = methodNotFound;
2819 currentResolutionContext = resolveContext;
2820 for (MethodResolutionPhase phase : methodResolutionSteps) {
2821 if (!phase.isApplicable(boxingEnabled, varargsEnabled) ||
2822 lookupHelper.shouldStop(bestSoFar, phase)) break;
2823 MethodResolutionPhase prevPhase = currentResolutionContext.step;
2824 Symbol prevBest = bestSoFar;
2825 currentResolutionContext.step = phase;
2826 bestSoFar = phase.mergeResults(bestSoFar, lookupHelper.lookup(env, phase));
2827 env.info.pendingResolutionPhase = (prevBest == bestSoFar) ? prevPhase : phase;
2828 }
2829 return lookupHelper.access(env, pos, location, bestSoFar);
2830 } finally {
2831 currentResolutionContext = prevResolutionContext;
2832 }
2833 }
2835 /**
2836 * Resolve `c.name' where name == this or name == super.
2837 * @param pos The position to use for error reporting.
2838 * @param env The environment current at the expression.
2839 * @param c The qualifier.
2840 * @param name The identifier's name.
2841 */
2842 Symbol resolveSelf(DiagnosticPosition pos,
2843 Env<AttrContext> env,
2844 TypeSymbol c,
2845 Name name) {
2846 Env<AttrContext> env1 = env;
2847 boolean staticOnly = false;
2848 while (env1.outer != null) {
2849 if (isStatic(env1)) staticOnly = true;
2850 if (env1.enclClass.sym == c) {
2851 Symbol sym = env1.info.scope.lookup(name).sym;
2852 if (sym != null) {
2853 if (staticOnly) sym = new StaticError(sym);
2854 return accessBase(sym, pos, env.enclClass.sym.type,
2855 name, true);
2856 }
2857 }
2858 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
2859 env1 = env1.outer;
2860 }
2861 if (allowDefaultMethods && c.isInterface() &&
2862 name == names._super && !isStatic(env) &&
2863 types.isDirectSuperInterface(c, env.enclClass.sym)) {
2864 //this might be a default super call if one of the superinterfaces is 'c'
2865 for (Type t : pruneInterfaces(env.enclClass.type)) {
2866 if (t.tsym == c) {
2867 env.info.defaultSuperCallSite = t;
2868 return new VarSymbol(0, names._super,
2869 types.asSuper(env.enclClass.type, c), env.enclClass.sym);
2870 }
2871 }
2872 //find a direct superinterface that is a subtype of 'c'
2873 for (Type i : types.interfaces(env.enclClass.type)) {
2874 if (i.tsym.isSubClass(c, types) && i.tsym != c) {
2875 log.error(pos, "illegal.default.super.call", c,
2876 diags.fragment("redundant.supertype", c, i));
2877 return syms.errSymbol;
2878 }
2879 }
2880 Assert.error();
2881 }
2882 log.error(pos, "not.encl.class", c);
2883 return syms.errSymbol;
2884 }
2885 //where
2886 private List<Type> pruneInterfaces(Type t) {
2887 ListBuffer<Type> result = ListBuffer.lb();
2888 for (Type t1 : types.interfaces(t)) {
2889 boolean shouldAdd = true;
2890 for (Type t2 : types.interfaces(t)) {
2891 if (t1 != t2 && types.isSubtypeNoCapture(t2, t1)) {
2892 shouldAdd = false;
2893 }
2894 }
2895 if (shouldAdd) {
2896 result.append(t1);
2897 }
2898 }
2899 return result.toList();
2900 }
2903 /**
2904 * Resolve `c.this' for an enclosing class c that contains the
2905 * named member.
2906 * @param pos The position to use for error reporting.
2907 * @param env The environment current at the expression.
2908 * @param member The member that must be contained in the result.
2909 */
2910 Symbol resolveSelfContaining(DiagnosticPosition pos,
2911 Env<AttrContext> env,
2912 Symbol member,
2913 boolean isSuperCall) {
2914 Symbol sym = resolveSelfContainingInternal(env, member, isSuperCall);
2915 if (sym == null) {
2916 log.error(pos, "encl.class.required", member);
2917 return syms.errSymbol;
2918 } else {
2919 return accessBase(sym, pos, env.enclClass.sym.type, sym.name, true);
2920 }
2921 }
2923 boolean hasEnclosingInstance(Env<AttrContext> env, Type type) {
2924 Symbol encl = resolveSelfContainingInternal(env, type.tsym, false);
2925 return encl != null && encl.kind < ERRONEOUS;
2926 }
2928 private Symbol resolveSelfContainingInternal(Env<AttrContext> env,
2929 Symbol member,
2930 boolean isSuperCall) {
2931 Name name = names._this;
2932 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
2933 boolean staticOnly = false;
2934 if (env1 != null) {
2935 while (env1 != null && env1.outer != null) {
2936 if (isStatic(env1)) staticOnly = true;
2937 if (env1.enclClass.sym.isSubClass(member.owner, types)) {
2938 Symbol sym = env1.info.scope.lookup(name).sym;
2939 if (sym != null) {
2940 if (staticOnly) sym = new StaticError(sym);
2941 return sym;
2942 }
2943 }
2944 if ((env1.enclClass.sym.flags() & STATIC) != 0)
2945 staticOnly = true;
2946 env1 = env1.outer;
2947 }
2948 }
2949 return null;
2950 }
2952 /**
2953 * Resolve an appropriate implicit this instance for t's container.
2954 * JLS 8.8.5.1 and 15.9.2
2955 */
2956 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
2957 return resolveImplicitThis(pos, env, t, false);
2958 }
2960 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
2961 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
2962 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
2963 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
2964 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
2965 log.error(pos, "cant.ref.before.ctor.called", "this");
2966 return thisType;
2967 }
2969 /* ***************************************************************************
2970 * ResolveError classes, indicating error situations when accessing symbols
2971 ****************************************************************************/
2973 //used by TransTypes when checking target type of synthetic cast
2974 public void logAccessErrorInternal(Env<AttrContext> env, JCTree tree, Type type) {
2975 AccessError error = new AccessError(env, env.enclClass.type, type.tsym);
2976 logResolveError(error, tree.pos(), env.enclClass.sym, env.enclClass.type, null, null, null);
2977 }
2978 //where
2979 private void logResolveError(ResolveError error,
2980 DiagnosticPosition pos,
2981 Symbol location,
2982 Type site,
2983 Name name,
2984 List<Type> argtypes,
2985 List<Type> typeargtypes) {
2986 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
2987 pos, location, site, name, argtypes, typeargtypes);
2988 if (d != null) {
2989 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
2990 log.report(d);
2991 }
2992 }
2994 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
2996 public Object methodArguments(List<Type> argtypes) {
2997 if (argtypes == null || argtypes.isEmpty()) {
2998 return noArgs;
2999 } else {
3000 ListBuffer<Object> diagArgs = ListBuffer.lb();
3001 for (Type t : argtypes) {
3002 if (t.hasTag(DEFERRED)) {
3003 diagArgs.append(((DeferredAttr.DeferredType)t).tree);
3004 } else {
3005 diagArgs.append(t);
3006 }
3007 }
3008 return diagArgs;
3009 }
3010 }
3012 /**
3013 * Root class for resolution errors. Subclass of ResolveError
3014 * represent a different kinds of resolution error - as such they must
3015 * specify how they map into concrete compiler diagnostics.
3016 */
3017 abstract class ResolveError extends Symbol {
3019 /** The name of the kind of error, for debugging only. */
3020 final String debugName;
3022 ResolveError(int kind, String debugName) {
3023 super(kind, 0, null, null, null);
3024 this.debugName = debugName;
3025 }
3027 @Override
3028 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
3029 throw new AssertionError();
3030 }
3032 @Override
3033 public String toString() {
3034 return debugName;
3035 }
3037 @Override
3038 public boolean exists() {
3039 return false;
3040 }
3042 /**
3043 * Create an external representation for this erroneous symbol to be
3044 * used during attribution - by default this returns the symbol of a
3045 * brand new error type which stores the original type found
3046 * during resolution.
3047 *
3048 * @param name the name used during resolution
3049 * @param location the location from which the symbol is accessed
3050 */
3051 protected Symbol access(Name name, TypeSymbol location) {
3052 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3053 }
3055 /**
3056 * Create a diagnostic representing this resolution error.
3057 *
3058 * @param dkind The kind of the diagnostic to be created (e.g error).
3059 * @param pos The position to be used for error reporting.
3060 * @param site The original type from where the selection took place.
3061 * @param name The name of the symbol to be resolved.
3062 * @param argtypes The invocation's value arguments,
3063 * if we looked for a method.
3064 * @param typeargtypes The invocation's type arguments,
3065 * if we looked for a method.
3066 */
3067 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3068 DiagnosticPosition pos,
3069 Symbol location,
3070 Type site,
3071 Name name,
3072 List<Type> argtypes,
3073 List<Type> typeargtypes);
3074 }
3076 /**
3077 * This class is the root class of all resolution errors caused by
3078 * an invalid symbol being found during resolution.
3079 */
3080 abstract class InvalidSymbolError extends ResolveError {
3082 /** The invalid symbol found during resolution */
3083 Symbol sym;
3085 InvalidSymbolError(int kind, Symbol sym, String debugName) {
3086 super(kind, debugName);
3087 this.sym = sym;
3088 }
3090 @Override
3091 public boolean exists() {
3092 return true;
3093 }
3095 @Override
3096 public String toString() {
3097 return super.toString() + " wrongSym=" + sym;
3098 }
3100 @Override
3101 public Symbol access(Name name, TypeSymbol location) {
3102 if ((sym.kind & ERRONEOUS) == 0 && (sym.kind & TYP) != 0)
3103 return types.createErrorType(name, location, sym.type).tsym;
3104 else
3105 return sym;
3106 }
3107 }
3109 /**
3110 * InvalidSymbolError error class indicating that a symbol matching a
3111 * given name does not exists in a given site.
3112 */
3113 class SymbolNotFoundError extends ResolveError {
3115 SymbolNotFoundError(int kind) {
3116 super(kind, "symbol not found error");
3117 }
3119 @Override
3120 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3121 DiagnosticPosition pos,
3122 Symbol location,
3123 Type site,
3124 Name name,
3125 List<Type> argtypes,
3126 List<Type> typeargtypes) {
3127 argtypes = argtypes == null ? List.<Type>nil() : argtypes;
3128 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes;
3129 if (name == names.error)
3130 return null;
3132 if (syms.operatorNames.contains(name)) {
3133 boolean isUnaryOp = argtypes.size() == 1;
3134 String key = argtypes.size() == 1 ?
3135 "operator.cant.be.applied" :
3136 "operator.cant.be.applied.1";
3137 Type first = argtypes.head;
3138 Type second = !isUnaryOp ? argtypes.tail.head : null;
3139 return diags.create(dkind, log.currentSource(), pos,
3140 key, name, first, second);
3141 }
3142 boolean hasLocation = false;
3143 if (location == null) {
3144 location = site.tsym;
3145 }
3146 if (!location.name.isEmpty()) {
3147 if (location.kind == PCK && !site.tsym.exists()) {
3148 return diags.create(dkind, log.currentSource(), pos,
3149 "doesnt.exist", location);
3150 }
3151 hasLocation = !location.name.equals(names._this) &&
3152 !location.name.equals(names._super);
3153 }
3154 boolean isConstructor = kind == ABSENT_MTH && name == names.init;
3155 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : absentKind(kind);
3156 Name idname = isConstructor ? site.tsym.name : name;
3157 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
3158 if (hasLocation) {
3159 return diags.create(dkind, log.currentSource(), pos,
3160 errKey, kindname, idname, //symbol kindname, name
3161 typeargtypes, args(argtypes), //type parameters and arguments (if any)
3162 getLocationDiag(location, site)); //location kindname, type
3163 }
3164 else {
3165 return diags.create(dkind, log.currentSource(), pos,
3166 errKey, kindname, idname, //symbol kindname, name
3167 typeargtypes, args(argtypes)); //type parameters and arguments (if any)
3168 }
3169 }
3170 //where
3171 private Object args(List<Type> args) {
3172 return args.isEmpty() ? args : methodArguments(args);
3173 }
3175 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
3176 String key = "cant.resolve";
3177 String suffix = hasLocation ? ".location" : "";
3178 switch (kindname) {
3179 case METHOD:
3180 case CONSTRUCTOR: {
3181 suffix += ".args";
3182 suffix += hasTypeArgs ? ".params" : "";
3183 }
3184 }
3185 return key + suffix;
3186 }
3187 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
3188 if (location.kind == VAR) {
3189 return diags.fragment("location.1",
3190 kindName(location),
3191 location,
3192 location.type);
3193 } else {
3194 return diags.fragment("location",
3195 typeKindName(site),
3196 site,
3197 null);
3198 }
3199 }
3200 }
3202 /**
3203 * InvalidSymbolError error class indicating that a given symbol
3204 * (either a method, a constructor or an operand) is not applicable
3205 * given an actual arguments/type argument list.
3206 */
3207 class InapplicableSymbolError extends ResolveError {
3209 protected MethodResolutionContext resolveContext;
3211 InapplicableSymbolError(MethodResolutionContext context) {
3212 this(WRONG_MTH, "inapplicable symbol error", context);
3213 }
3215 protected InapplicableSymbolError(int kind, String debugName, MethodResolutionContext context) {
3216 super(kind, debugName);
3217 this.resolveContext = context;
3218 }
3220 @Override
3221 public String toString() {
3222 return super.toString();
3223 }
3225 @Override
3226 public boolean exists() {
3227 return true;
3228 }
3230 @Override
3231 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3232 DiagnosticPosition pos,
3233 Symbol location,
3234 Type site,
3235 Name name,
3236 List<Type> argtypes,
3237 List<Type> typeargtypes) {
3238 if (name == names.error)
3239 return null;
3241 if (syms.operatorNames.contains(name)) {
3242 boolean isUnaryOp = argtypes.size() == 1;
3243 String key = argtypes.size() == 1 ?
3244 "operator.cant.be.applied" :
3245 "operator.cant.be.applied.1";
3246 Type first = argtypes.head;
3247 Type second = !isUnaryOp ? argtypes.tail.head : null;
3248 return diags.create(dkind, log.currentSource(), pos,
3249 key, name, first, second);
3250 }
3251 else {
3252 Candidate c = errCandidate();
3253 Symbol ws = c.sym.asMemberOf(site, types);
3254 return diags.create(dkind, log.currentSource(), pos,
3255 "cant.apply.symbol",
3256 kindName(ws),
3257 ws.name == names.init ? ws.owner.name : ws.name,
3258 methodArguments(ws.type.getParameterTypes()),
3259 methodArguments(argtypes),
3260 kindName(ws.owner),
3261 ws.owner.type,
3262 c.details);
3263 }
3264 }
3266 @Override
3267 public Symbol access(Name name, TypeSymbol location) {
3268 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
3269 }
3271 private Candidate errCandidate() {
3272 Candidate bestSoFar = null;
3273 for (Candidate c : resolveContext.candidates) {
3274 if (c.isApplicable()) continue;
3275 bestSoFar = c;
3276 }
3277 Assert.checkNonNull(bestSoFar);
3278 return bestSoFar;
3279 }
3280 }
3282 /**
3283 * ResolveError error class indicating that a set of symbols
3284 * (either methods, constructors or operands) is not applicable
3285 * given an actual arguments/type argument list.
3286 */
3287 class InapplicableSymbolsError extends InapplicableSymbolError {
3289 InapplicableSymbolsError(MethodResolutionContext context) {
3290 super(WRONG_MTHS, "inapplicable symbols", context);
3291 }
3293 @Override
3294 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3295 DiagnosticPosition pos,
3296 Symbol location,
3297 Type site,
3298 Name name,
3299 List<Type> argtypes,
3300 List<Type> typeargtypes) {
3301 if (!resolveContext.candidates.isEmpty()) {
3302 JCDiagnostic err = diags.create(dkind,
3303 log.currentSource(),
3304 pos,
3305 "cant.apply.symbols",
3306 name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
3307 name == names.init ? site.tsym.name : name,
3308 methodArguments(argtypes));
3309 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(site));
3310 } else {
3311 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
3312 location, site, name, argtypes, typeargtypes);
3313 }
3314 }
3316 //where
3317 List<JCDiagnostic> candidateDetails(Type site) {
3318 Map<Symbol, JCDiagnostic> details = new LinkedHashMap<Symbol, JCDiagnostic>();
3319 for (Candidate c : resolveContext.candidates) {
3320 if (c.isApplicable()) continue;
3321 JCDiagnostic detailDiag = diags.fragment("inapplicable.method",
3322 Kinds.kindName(c.sym),
3323 c.sym.location(site, types),
3324 c.sym.asMemberOf(site, types),
3325 c.details);
3326 details.put(c.sym, detailDiag);
3327 }
3328 return List.from(details.values());
3329 }
3330 }
3332 /**
3333 * An InvalidSymbolError error class indicating that a symbol is not
3334 * accessible from a given site
3335 */
3336 class AccessError extends InvalidSymbolError {
3338 private Env<AttrContext> env;
3339 private Type site;
3341 AccessError(Symbol sym) {
3342 this(null, null, sym);
3343 }
3345 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
3346 super(HIDDEN, sym, "access error");
3347 this.env = env;
3348 this.site = site;
3349 if (debugResolve)
3350 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
3351 }
3353 @Override
3354 public boolean exists() {
3355 return false;
3356 }
3358 @Override
3359 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3360 DiagnosticPosition pos,
3361 Symbol location,
3362 Type site,
3363 Name name,
3364 List<Type> argtypes,
3365 List<Type> typeargtypes) {
3366 if (sym.owner.type.hasTag(ERROR))
3367 return null;
3369 if (sym.name == names.init && sym.owner != site.tsym) {
3370 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
3371 pos, location, site, name, argtypes, typeargtypes);
3372 }
3373 else if ((sym.flags() & PUBLIC) != 0
3374 || (env != null && this.site != null
3375 && !isAccessible(env, this.site))) {
3376 return diags.create(dkind, log.currentSource(),
3377 pos, "not.def.access.class.intf.cant.access",
3378 sym, sym.location());
3379 }
3380 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
3381 return diags.create(dkind, log.currentSource(),
3382 pos, "report.access", sym,
3383 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
3384 sym.location());
3385 }
3386 else {
3387 return diags.create(dkind, log.currentSource(),
3388 pos, "not.def.public.cant.access", sym, sym.location());
3389 }
3390 }
3391 }
3393 /**
3394 * InvalidSymbolError error class indicating that an instance member
3395 * has erroneously been accessed from a static context.
3396 */
3397 class StaticError extends InvalidSymbolError {
3399 StaticError(Symbol sym) {
3400 super(STATICERR, sym, "static error");
3401 }
3403 @Override
3404 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3405 DiagnosticPosition pos,
3406 Symbol location,
3407 Type site,
3408 Name name,
3409 List<Type> argtypes,
3410 List<Type> typeargtypes) {
3411 Symbol errSym = ((sym.kind == TYP && sym.type.hasTag(CLASS))
3412 ? types.erasure(sym.type).tsym
3413 : sym);
3414 return diags.create(dkind, log.currentSource(), pos,
3415 "non-static.cant.be.ref", kindName(sym), errSym);
3416 }
3417 }
3419 /**
3420 * InvalidSymbolError error class indicating that a pair of symbols
3421 * (either methods, constructors or operands) are ambiguous
3422 * given an actual arguments/type argument list.
3423 */
3424 class AmbiguityError extends ResolveError {
3426 /** The other maximally specific symbol */
3427 List<Symbol> ambiguousSyms = List.nil();
3429 @Override
3430 public boolean exists() {
3431 return true;
3432 }
3434 AmbiguityError(Symbol sym1, Symbol sym2) {
3435 super(AMBIGUOUS, "ambiguity error");
3436 ambiguousSyms = flatten(sym2).appendList(flatten(sym1));
3437 }
3439 private List<Symbol> flatten(Symbol sym) {
3440 if (sym.kind == AMBIGUOUS) {
3441 return ((AmbiguityError)sym).ambiguousSyms;
3442 } else {
3443 return List.of(sym);
3444 }
3445 }
3447 AmbiguityError addAmbiguousSymbol(Symbol s) {
3448 ambiguousSyms = ambiguousSyms.prepend(s);
3449 return this;
3450 }
3452 @Override
3453 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
3454 DiagnosticPosition pos,
3455 Symbol location,
3456 Type site,
3457 Name name,
3458 List<Type> argtypes,
3459 List<Type> typeargtypes) {
3460 List<Symbol> diagSyms = ambiguousSyms.reverse();
3461 Symbol s1 = diagSyms.head;
3462 Symbol s2 = diagSyms.tail.head;
3463 Name sname = s1.name;
3464 if (sname == names.init) sname = s1.owner.name;
3465 return diags.create(dkind, log.currentSource(),
3466 pos, "ref.ambiguous", sname,
3467 kindName(s1),
3468 s1,
3469 s1.location(site, types),
3470 kindName(s2),
3471 s2,
3472 s2.location(site, types));
3473 }
3475 /**
3476 * If multiple applicable methods are found during overload and none of them
3477 * is more specific than the others, attempt to merge their signatures.
3478 */
3479 Symbol mergeAbstracts(Type site) {
3480 Symbol fst = ambiguousSyms.last();
3481 Symbol res = fst;
3482 for (Symbol s : ambiguousSyms.reverse()) {
3483 Type mt1 = types.memberType(site, res);
3484 Type mt2 = types.memberType(site, s);
3485 if ((s.flags() & ABSTRACT) == 0 ||
3486 !types.overrideEquivalent(mt1, mt2) ||
3487 !types.isSameTypes(fst.erasure(types).getParameterTypes(),
3488 s.erasure(types).getParameterTypes())) {
3489 //ambiguity cannot be resolved
3490 return this;
3491 } else {
3492 Type mst = mostSpecificReturnType(mt1, mt2);
3493 if (mst == null) {
3494 // Theoretically, this can't happen, but it is possible
3495 // due to error recovery or mixing incompatible class files
3496 return this;
3497 }
3498 Symbol mostSpecific = mst == mt1 ? res : s;
3499 List<Type> allThrown = chk.intersect(mt1.getThrownTypes(), mt2.getThrownTypes());
3500 Type newSig = types.createMethodTypeWithThrown(mostSpecific.type, allThrown);
3501 res = new MethodSymbol(
3502 mostSpecific.flags(),
3503 mostSpecific.name,
3504 newSig,
3505 mostSpecific.owner);
3506 }
3507 }
3508 return res;
3509 }
3511 @Override
3512 protected Symbol access(Name name, TypeSymbol location) {
3513 Symbol firstAmbiguity = ambiguousSyms.last();
3514 return firstAmbiguity.kind == TYP ?
3515 types.createErrorType(name, location, firstAmbiguity.type).tsym :
3516 firstAmbiguity;
3517 }
3518 }
3520 enum MethodResolutionPhase {
3521 BASIC(false, false),
3522 BOX(true, false),
3523 VARARITY(true, true) {
3524 @Override
3525 public Symbol mergeResults(Symbol bestSoFar, Symbol sym) {
3526 switch (sym.kind) {
3527 case WRONG_MTH:
3528 return (bestSoFar.kind == WRONG_MTH || bestSoFar.kind == WRONG_MTHS) ?
3529 bestSoFar :
3530 sym;
3531 case ABSENT_MTH:
3532 return bestSoFar;
3533 default:
3534 return sym;
3535 }
3536 }
3537 };
3539 final boolean isBoxingRequired;
3540 final boolean isVarargsRequired;
3542 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
3543 this.isBoxingRequired = isBoxingRequired;
3544 this.isVarargsRequired = isVarargsRequired;
3545 }
3547 public boolean isBoxingRequired() {
3548 return isBoxingRequired;
3549 }
3551 public boolean isVarargsRequired() {
3552 return isVarargsRequired;
3553 }
3555 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
3556 return (varargsEnabled || !isVarargsRequired) &&
3557 (boxingEnabled || !isBoxingRequired);
3558 }
3560 public Symbol mergeResults(Symbol prev, Symbol sym) {
3561 return sym;
3562 }
3563 }
3565 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
3567 /**
3568 * A resolution context is used to keep track of intermediate results of
3569 * overload resolution, such as list of method that are not applicable
3570 * (used to generate more precise diagnostics) and so on. Resolution contexts
3571 * can be nested - this means that when each overload resolution routine should
3572 * work within the resolution context it created.
3573 */
3574 class MethodResolutionContext {
3576 private List<Candidate> candidates = List.nil();
3578 MethodResolutionPhase step = null;
3580 private boolean internalResolution = false;
3581 private DeferredAttr.AttrMode attrMode = DeferredAttr.AttrMode.SPECULATIVE;
3583 void addInapplicableCandidate(Symbol sym, JCDiagnostic details) {
3584 Candidate c = new Candidate(currentResolutionContext.step, sym, details, null);
3585 candidates = candidates.append(c);
3586 }
3588 void addApplicableCandidate(Symbol sym, Type mtype) {
3589 Candidate c = new Candidate(currentResolutionContext.step, sym, null, mtype);
3590 candidates = candidates.append(c);
3591 }
3593 DeferredAttrContext deferredAttrContext(Symbol sym, InferenceContext inferenceContext) {
3594 return deferredAttr.new DeferredAttrContext(attrMode, sym, step, inferenceContext);
3595 }
3597 /**
3598 * This class represents an overload resolution candidate. There are two
3599 * kinds of candidates: applicable methods and inapplicable methods;
3600 * applicable methods have a pointer to the instantiated method type,
3601 * while inapplicable candidates contain further details about the
3602 * reason why the method has been considered inapplicable.
3603 */
3604 class Candidate {
3606 final MethodResolutionPhase step;
3607 final Symbol sym;
3608 final JCDiagnostic details;
3609 final Type mtype;
3611 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details, Type mtype) {
3612 this.step = step;
3613 this.sym = sym;
3614 this.details = details;
3615 this.mtype = mtype;
3616 }
3618 @Override
3619 public boolean equals(Object o) {
3620 if (o instanceof Candidate) {
3621 Symbol s1 = this.sym;
3622 Symbol s2 = ((Candidate)o).sym;
3623 if ((s1 != s2 &&
3624 (s1.overrides(s2, s1.owner.type.tsym, types, false) ||
3625 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) ||
3626 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner))
3627 return true;
3628 }
3629 return false;
3630 }
3632 boolean isApplicable() {
3633 return mtype != null;
3634 }
3635 }
3637 DeferredAttr.AttrMode attrMode() {
3638 return attrMode;
3639 }
3641 boolean internal() {
3642 return internalResolution;
3643 }
3644 }
3646 MethodResolutionContext currentResolutionContext = null;
3647 }
