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src/share/classes/com/sun/tools/javac/comp/Resolve.java@0b5beb9562c6
src/share/classes/com/sun/tools/javac/comp/Resolve.java
Wed, 27 Jul 2011 19:00:53 +0100
- author
- mcimadamore
- date
- Wed, 27 Jul 2011 19:00:53 +0100
- changeset 1059
- 0b5beb9562c6
- parent 1006
- a2d422d480cb
- child 1110
- 366c233eb838
- permissions
- -rw-r--r--
7062745: Regression: difference in overload resolution when two methods are maximally specific
Summary: Fix most specific when two methods are maximally specific and only one has non-raw return type
Reviewed-by: jjg, dlsmith
1 /*
2 * Copyright (c) 1999, 2011, 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.util.*;
29 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
30 import com.sun.tools.javac.code.*;
31 import com.sun.tools.javac.jvm.*;
32 import com.sun.tools.javac.tree.*;
33 import com.sun.tools.javac.api.Formattable.LocalizedString;
34 import static com.sun.tools.javac.comp.Resolve.MethodResolutionPhase.*;
36 import com.sun.tools.javac.code.Type.*;
37 import com.sun.tools.javac.code.Symbol.*;
38 import com.sun.tools.javac.tree.JCTree.*;
40 import static com.sun.tools.javac.code.Flags.*;
41 import static com.sun.tools.javac.code.Kinds.*;
42 import static com.sun.tools.javac.code.TypeTags.*;
43 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
44 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticType;
45 import javax.lang.model.element.ElementVisitor;
47 import java.util.Map;
48 import java.util.Set;
49 import java.util.HashMap;
50 import java.util.HashSet;
52 /** Helper class for name resolution, used mostly by the attribution phase.
53 *
54 * <p><b>This is NOT part of any supported API.
55 * If you write code that depends on this, you do so at your own risk.
56 * This code and its internal interfaces are subject to change or
57 * deletion without notice.</b>
58 */
59 public class Resolve {
60 protected static final Context.Key<Resolve> resolveKey =
61 new Context.Key<Resolve>();
63 Names names;
64 Log log;
65 Symtab syms;
66 Check chk;
67 Infer infer;
68 ClassReader reader;
69 TreeInfo treeinfo;
70 Types types;
71 JCDiagnostic.Factory diags;
72 public final boolean boxingEnabled; // = source.allowBoxing();
73 public final boolean varargsEnabled; // = source.allowVarargs();
74 public final boolean allowMethodHandles;
75 private final boolean debugResolve;
77 Scope polymorphicSignatureScope;
79 public static Resolve instance(Context context) {
80 Resolve instance = context.get(resolveKey);
81 if (instance == null)
82 instance = new Resolve(context);
83 return instance;
84 }
86 protected Resolve(Context context) {
87 context.put(resolveKey, this);
88 syms = Symtab.instance(context);
90 varNotFound = new
91 SymbolNotFoundError(ABSENT_VAR);
92 wrongMethod = new
93 InapplicableSymbolError(syms.errSymbol);
94 wrongMethods = new
95 InapplicableSymbolsError(syms.errSymbol);
96 methodNotFound = new
97 SymbolNotFoundError(ABSENT_MTH);
98 typeNotFound = new
99 SymbolNotFoundError(ABSENT_TYP);
101 names = Names.instance(context);
102 log = Log.instance(context);
103 chk = Check.instance(context);
104 infer = Infer.instance(context);
105 reader = ClassReader.instance(context);
106 treeinfo = TreeInfo.instance(context);
107 types = Types.instance(context);
108 diags = JCDiagnostic.Factory.instance(context);
109 Source source = Source.instance(context);
110 boxingEnabled = source.allowBoxing();
111 varargsEnabled = source.allowVarargs();
112 Options options = Options.instance(context);
113 debugResolve = options.isSet("debugresolve");
114 Target target = Target.instance(context);
115 allowMethodHandles = target.hasMethodHandles();
116 polymorphicSignatureScope = new Scope(syms.noSymbol);
118 inapplicableMethodException = new InapplicableMethodException(diags);
119 }
121 /** error symbols, which are returned when resolution fails
122 */
123 final SymbolNotFoundError varNotFound;
124 final InapplicableSymbolError wrongMethod;
125 final InapplicableSymbolsError wrongMethods;
126 final SymbolNotFoundError methodNotFound;
127 final SymbolNotFoundError typeNotFound;
129 /* ************************************************************************
130 * Identifier resolution
131 *************************************************************************/
133 /** An environment is "static" if its static level is greater than
134 * the one of its outer environment
135 */
136 static boolean isStatic(Env<AttrContext> env) {
137 return env.info.staticLevel > env.outer.info.staticLevel;
138 }
140 /** An environment is an "initializer" if it is a constructor or
141 * an instance initializer.
142 */
143 static boolean isInitializer(Env<AttrContext> env) {
144 Symbol owner = env.info.scope.owner;
145 return owner.isConstructor() ||
146 owner.owner.kind == TYP &&
147 (owner.kind == VAR ||
148 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
149 (owner.flags() & STATIC) == 0;
150 }
152 /** Is class accessible in given evironment?
153 * @param env The current environment.
154 * @param c The class whose accessibility is checked.
155 */
156 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
157 return isAccessible(env, c, false);
158 }
160 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c, boolean checkInner) {
161 boolean isAccessible = false;
162 switch ((short)(c.flags() & AccessFlags)) {
163 case PRIVATE:
164 isAccessible =
165 env.enclClass.sym.outermostClass() ==
166 c.owner.outermostClass();
167 break;
168 case 0:
169 isAccessible =
170 env.toplevel.packge == c.owner // fast special case
171 ||
172 env.toplevel.packge == c.packge()
173 ||
174 // Hack: this case is added since synthesized default constructors
175 // of anonymous classes should be allowed to access
176 // classes which would be inaccessible otherwise.
177 env.enclMethod != null &&
178 (env.enclMethod.mods.flags & ANONCONSTR) != 0;
179 break;
180 default: // error recovery
181 case PUBLIC:
182 isAccessible = true;
183 break;
184 case PROTECTED:
185 isAccessible =
186 env.toplevel.packge == c.owner // fast special case
187 ||
188 env.toplevel.packge == c.packge()
189 ||
190 isInnerSubClass(env.enclClass.sym, c.owner);
191 break;
192 }
193 return (checkInner == false || c.type.getEnclosingType() == Type.noType) ?
194 isAccessible :
195 isAccessible && isAccessible(env, c.type.getEnclosingType(), checkInner);
196 }
197 //where
198 /** Is given class a subclass of given base class, or an inner class
199 * of a subclass?
200 * Return null if no such class exists.
201 * @param c The class which is the subclass or is contained in it.
202 * @param base The base class
203 */
204 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
205 while (c != null && !c.isSubClass(base, types)) {
206 c = c.owner.enclClass();
207 }
208 return c != null;
209 }
211 boolean isAccessible(Env<AttrContext> env, Type t) {
212 return isAccessible(env, t, false);
213 }
215 boolean isAccessible(Env<AttrContext> env, Type t, boolean checkInner) {
216 return (t.tag == ARRAY)
217 ? isAccessible(env, types.elemtype(t))
218 : isAccessible(env, t.tsym, checkInner);
219 }
221 /** Is symbol accessible as a member of given type in given evironment?
222 * @param env The current environment.
223 * @param site The type of which the tested symbol is regarded
224 * as a member.
225 * @param sym The symbol.
226 */
227 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
228 return isAccessible(env, site, sym, false);
229 }
230 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym, boolean checkInner) {
231 if (sym.name == names.init && sym.owner != site.tsym) return false;
232 switch ((short)(sym.flags() & AccessFlags)) {
233 case PRIVATE:
234 return
235 (env.enclClass.sym == sym.owner // fast special case
236 ||
237 env.enclClass.sym.outermostClass() ==
238 sym.owner.outermostClass())
239 &&
240 sym.isInheritedIn(site.tsym, types);
241 case 0:
242 return
243 (env.toplevel.packge == sym.owner.owner // fast special case
244 ||
245 env.toplevel.packge == sym.packge())
246 &&
247 isAccessible(env, site, checkInner)
248 &&
249 sym.isInheritedIn(site.tsym, types)
250 &&
251 notOverriddenIn(site, sym);
252 case PROTECTED:
253 return
254 (env.toplevel.packge == sym.owner.owner // fast special case
255 ||
256 env.toplevel.packge == sym.packge()
257 ||
258 isProtectedAccessible(sym, env.enclClass.sym, site)
259 ||
260 // OK to select instance method or field from 'super' or type name
261 // (but type names should be disallowed elsewhere!)
262 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
263 &&
264 isAccessible(env, site, checkInner)
265 &&
266 notOverriddenIn(site, sym);
267 default: // this case includes erroneous combinations as well
268 return isAccessible(env, site, checkInner) && notOverriddenIn(site, sym);
269 }
270 }
271 //where
272 /* `sym' is accessible only if not overridden by
273 * another symbol which is a member of `site'
274 * (because, if it is overridden, `sym' is not strictly
275 * speaking a member of `site'). A polymorphic signature method
276 * cannot be overridden (e.g. MH.invokeExact(Object[])).
277 */
278 private boolean notOverriddenIn(Type site, Symbol sym) {
279 if (sym.kind != MTH || sym.isConstructor() || sym.isStatic())
280 return true;
281 else {
282 Symbol s2 = ((MethodSymbol)sym).implementation(site.tsym, types, true);
283 return (s2 == null || s2 == sym || sym.owner == s2.owner ||
284 s2.isPolymorphicSignatureGeneric() ||
285 !types.isSubSignature(types.memberType(site, s2), types.memberType(site, sym)));
286 }
287 }
288 //where
289 /** Is given protected symbol accessible if it is selected from given site
290 * and the selection takes place in given class?
291 * @param sym The symbol with protected access
292 * @param c The class where the access takes place
293 * @site The type of the qualifier
294 */
295 private
296 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
297 while (c != null &&
298 !(c.isSubClass(sym.owner, types) &&
299 (c.flags() & INTERFACE) == 0 &&
300 // In JLS 2e 6.6.2.1, the subclass restriction applies
301 // only to instance fields and methods -- types are excluded
302 // regardless of whether they are declared 'static' or not.
303 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || site.tsym.isSubClass(c, types))))
304 c = c.owner.enclClass();
305 return c != null;
306 }
308 /** Try to instantiate the type of a method so that it fits
309 * given type arguments and argument types. If succesful, return
310 * the method's instantiated type, else return null.
311 * The instantiation will take into account an additional leading
312 * formal parameter if the method is an instance method seen as a member
313 * of un underdetermined site In this case, we treat site as an additional
314 * parameter and the parameters of the class containing the method as
315 * additional type variables that get instantiated.
316 *
317 * @param env The current environment
318 * @param site The type of which the method is a member.
319 * @param m The method symbol.
320 * @param argtypes The invocation's given value arguments.
321 * @param typeargtypes The invocation's given type arguments.
322 * @param allowBoxing Allow boxing conversions of arguments.
323 * @param useVarargs Box trailing arguments into an array for varargs.
324 */
325 Type rawInstantiate(Env<AttrContext> env,
326 Type site,
327 Symbol m,
328 List<Type> argtypes,
329 List<Type> typeargtypes,
330 boolean allowBoxing,
331 boolean useVarargs,
332 Warner warn)
333 throws Infer.InferenceException {
334 boolean polymorphicSignature = m.isPolymorphicSignatureGeneric() && allowMethodHandles;
335 if (useVarargs && (m.flags() & VARARGS) == 0)
336 throw inapplicableMethodException.setMessage();
337 Type mt = types.memberType(site, m);
339 // tvars is the list of formal type variables for which type arguments
340 // need to inferred.
341 List<Type> tvars = null;
342 if (env.info.tvars != null) {
343 tvars = types.newInstances(env.info.tvars);
344 mt = types.subst(mt, env.info.tvars, tvars);
345 }
346 if (typeargtypes == null) typeargtypes = List.nil();
347 if (mt.tag != FORALL && typeargtypes.nonEmpty()) {
348 // This is not a polymorphic method, but typeargs are supplied
349 // which is fine, see JLS 15.12.2.1
350 } else if (mt.tag == FORALL && typeargtypes.nonEmpty()) {
351 ForAll pmt = (ForAll) mt;
352 if (typeargtypes.length() != pmt.tvars.length())
353 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
354 // Check type arguments are within bounds
355 List<Type> formals = pmt.tvars;
356 List<Type> actuals = typeargtypes;
357 while (formals.nonEmpty() && actuals.nonEmpty()) {
358 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
359 pmt.tvars, typeargtypes);
360 for (; bounds.nonEmpty(); bounds = bounds.tail)
361 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
362 throw inapplicableMethodException.setMessage("explicit.param.do.not.conform.to.bounds",actuals.head, bounds);
363 formals = formals.tail;
364 actuals = actuals.tail;
365 }
366 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
367 } else if (mt.tag == FORALL) {
368 ForAll pmt = (ForAll) mt;
369 List<Type> tvars1 = types.newInstances(pmt.tvars);
370 tvars = tvars.appendList(tvars1);
371 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
372 }
374 // find out whether we need to go the slow route via infer
375 boolean instNeeded = tvars.tail != null || /*inlined: tvars.nonEmpty()*/
376 polymorphicSignature;
377 for (List<Type> l = argtypes;
378 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
379 l = l.tail) {
380 if (l.head.tag == FORALL) instNeeded = true;
381 }
383 if (instNeeded)
384 return polymorphicSignature ?
385 infer.instantiatePolymorphicSignatureInstance(env, site, m.name, (MethodSymbol)m, argtypes) :
386 infer.instantiateMethod(env,
387 tvars,
388 (MethodType)mt,
389 m,
390 argtypes,
391 allowBoxing,
392 useVarargs,
393 warn);
395 checkRawArgumentsAcceptable(env, argtypes, mt.getParameterTypes(),
396 allowBoxing, useVarargs, warn);
397 return mt;
398 }
400 /** Same but returns null instead throwing a NoInstanceException
401 */
402 Type instantiate(Env<AttrContext> env,
403 Type site,
404 Symbol m,
405 List<Type> argtypes,
406 List<Type> typeargtypes,
407 boolean allowBoxing,
408 boolean useVarargs,
409 Warner warn) {
410 try {
411 return rawInstantiate(env, site, m, argtypes, typeargtypes,
412 allowBoxing, useVarargs, warn);
413 } catch (InapplicableMethodException ex) {
414 return null;
415 }
416 }
418 /** Check if a parameter list accepts a list of args.
419 */
420 boolean argumentsAcceptable(Env<AttrContext> env,
421 List<Type> argtypes,
422 List<Type> formals,
423 boolean allowBoxing,
424 boolean useVarargs,
425 Warner warn) {
426 try {
427 checkRawArgumentsAcceptable(env, argtypes, formals, allowBoxing, useVarargs, warn);
428 return true;
429 } catch (InapplicableMethodException ex) {
430 return false;
431 }
432 }
433 void checkRawArgumentsAcceptable(Env<AttrContext> env,
434 List<Type> argtypes,
435 List<Type> formals,
436 boolean allowBoxing,
437 boolean useVarargs,
438 Warner warn) {
439 Type varargsFormal = useVarargs ? formals.last() : null;
440 if (varargsFormal == null &&
441 argtypes.size() != formals.size()) {
442 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
443 }
445 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
446 boolean works = allowBoxing
447 ? types.isConvertible(argtypes.head, formals.head, warn)
448 : types.isSubtypeUnchecked(argtypes.head, formals.head, warn);
449 if (!works)
450 throw inapplicableMethodException.setMessage("no.conforming.assignment.exists",
451 argtypes.head,
452 formals.head);
453 argtypes = argtypes.tail;
454 formals = formals.tail;
455 }
457 if (formals.head != varargsFormal)
458 throw inapplicableMethodException.setMessage("arg.length.mismatch"); // not enough args
460 if (useVarargs) {
461 Type elt = types.elemtype(varargsFormal);
462 while (argtypes.nonEmpty()) {
463 if (!types.isConvertible(argtypes.head, elt, warn))
464 throw inapplicableMethodException.setMessage("varargs.argument.mismatch",
465 argtypes.head,
466 elt);
467 argtypes = argtypes.tail;
468 }
469 //check varargs element type accessibility
470 if (!isAccessible(env, elt)) {
471 Symbol location = env.enclClass.sym;
472 throw inapplicableMethodException.setMessage("inaccessible.varargs.type",
473 elt,
474 Kinds.kindName(location),
475 location);
476 }
477 }
478 return;
479 }
480 // where
481 public static class InapplicableMethodException extends RuntimeException {
482 private static final long serialVersionUID = 0;
484 JCDiagnostic diagnostic;
485 JCDiagnostic.Factory diags;
487 InapplicableMethodException(JCDiagnostic.Factory diags) {
488 this.diagnostic = null;
489 this.diags = diags;
490 }
491 InapplicableMethodException setMessage() {
492 this.diagnostic = null;
493 return this;
494 }
495 InapplicableMethodException setMessage(String key) {
496 this.diagnostic = key != null ? diags.fragment(key) : null;
497 return this;
498 }
499 InapplicableMethodException setMessage(String key, Object... args) {
500 this.diagnostic = key != null ? diags.fragment(key, args) : null;
501 return this;
502 }
503 InapplicableMethodException setMessage(JCDiagnostic diag) {
504 this.diagnostic = diag;
505 return this;
506 }
508 public JCDiagnostic getDiagnostic() {
509 return diagnostic;
510 }
511 }
512 private final InapplicableMethodException inapplicableMethodException;
514 /* ***************************************************************************
515 * Symbol lookup
516 * the following naming conventions for arguments are used
517 *
518 * env is the environment where the symbol was mentioned
519 * site is the type of which the symbol is a member
520 * name is the symbol's name
521 * if no arguments are given
522 * argtypes are the value arguments, if we search for a method
523 *
524 * If no symbol was found, a ResolveError detailing the problem is returned.
525 ****************************************************************************/
527 /** Find field. Synthetic fields are always skipped.
528 * @param env The current environment.
529 * @param site The original type from where the selection takes place.
530 * @param name The name of the field.
531 * @param c The class to search for the field. This is always
532 * a superclass or implemented interface of site's class.
533 */
534 Symbol findField(Env<AttrContext> env,
535 Type site,
536 Name name,
537 TypeSymbol c) {
538 while (c.type.tag == TYPEVAR)
539 c = c.type.getUpperBound().tsym;
540 Symbol bestSoFar = varNotFound;
541 Symbol sym;
542 Scope.Entry e = c.members().lookup(name);
543 while (e.scope != null) {
544 if (e.sym.kind == VAR && (e.sym.flags_field & SYNTHETIC) == 0) {
545 return isAccessible(env, site, e.sym)
546 ? e.sym : new AccessError(env, site, e.sym);
547 }
548 e = e.next();
549 }
550 Type st = types.supertype(c.type);
551 if (st != null && (st.tag == CLASS || st.tag == TYPEVAR)) {
552 sym = findField(env, site, name, st.tsym);
553 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
554 }
555 for (List<Type> l = types.interfaces(c.type);
556 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
557 l = l.tail) {
558 sym = findField(env, site, name, l.head.tsym);
559 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
560 sym.owner != bestSoFar.owner)
561 bestSoFar = new AmbiguityError(bestSoFar, sym);
562 else if (sym.kind < bestSoFar.kind)
563 bestSoFar = sym;
564 }
565 return bestSoFar;
566 }
568 /** Resolve a field identifier, throw a fatal error if not found.
569 * @param pos The position to use for error reporting.
570 * @param env The environment current at the method invocation.
571 * @param site The type of the qualifying expression, in which
572 * identifier is searched.
573 * @param name The identifier's name.
574 */
575 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
576 Type site, Name name) {
577 Symbol sym = findField(env, site, name, site.tsym);
578 if (sym.kind == VAR) return (VarSymbol)sym;
579 else throw new FatalError(
580 diags.fragment("fatal.err.cant.locate.field",
581 name));
582 }
584 /** Find unqualified variable or field with given name.
585 * Synthetic fields always skipped.
586 * @param env The current environment.
587 * @param name The name of the variable or field.
588 */
589 Symbol findVar(Env<AttrContext> env, Name name) {
590 Symbol bestSoFar = varNotFound;
591 Symbol sym;
592 Env<AttrContext> env1 = env;
593 boolean staticOnly = false;
594 while (env1.outer != null) {
595 if (isStatic(env1)) staticOnly = true;
596 Scope.Entry e = env1.info.scope.lookup(name);
597 while (e.scope != null &&
598 (e.sym.kind != VAR ||
599 (e.sym.flags_field & SYNTHETIC) != 0))
600 e = e.next();
601 sym = (e.scope != null)
602 ? e.sym
603 : findField(
604 env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
605 if (sym.exists()) {
606 if (staticOnly &&
607 sym.kind == VAR &&
608 sym.owner.kind == TYP &&
609 (sym.flags() & STATIC) == 0)
610 return new StaticError(sym);
611 else
612 return sym;
613 } else if (sym.kind < bestSoFar.kind) {
614 bestSoFar = sym;
615 }
617 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
618 env1 = env1.outer;
619 }
621 sym = findField(env, syms.predefClass.type, name, syms.predefClass);
622 if (sym.exists())
623 return sym;
624 if (bestSoFar.exists())
625 return bestSoFar;
627 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
628 for (; e.scope != null; e = e.next()) {
629 sym = e.sym;
630 Type origin = e.getOrigin().owner.type;
631 if (sym.kind == VAR) {
632 if (e.sym.owner.type != origin)
633 sym = sym.clone(e.getOrigin().owner);
634 return isAccessible(env, origin, sym)
635 ? sym : new AccessError(env, origin, sym);
636 }
637 }
639 Symbol origin = null;
640 e = env.toplevel.starImportScope.lookup(name);
641 for (; e.scope != null; e = e.next()) {
642 sym = e.sym;
643 if (sym.kind != VAR)
644 continue;
645 // invariant: sym.kind == VAR
646 if (bestSoFar.kind < AMBIGUOUS && sym.owner != bestSoFar.owner)
647 return new AmbiguityError(bestSoFar, sym);
648 else if (bestSoFar.kind >= VAR) {
649 origin = e.getOrigin().owner;
650 bestSoFar = isAccessible(env, origin.type, sym)
651 ? sym : new AccessError(env, origin.type, sym);
652 }
653 }
654 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
655 return bestSoFar.clone(origin);
656 else
657 return bestSoFar;
658 }
660 Warner noteWarner = new Warner();
662 /** Select the best method for a call site among two choices.
663 * @param env The current environment.
664 * @param site The original type from where the
665 * selection takes place.
666 * @param argtypes The invocation's value arguments,
667 * @param typeargtypes The invocation's type arguments,
668 * @param sym Proposed new best match.
669 * @param bestSoFar Previously found best match.
670 * @param allowBoxing Allow boxing conversions of arguments.
671 * @param useVarargs Box trailing arguments into an array for varargs.
672 */
673 @SuppressWarnings("fallthrough")
674 Symbol selectBest(Env<AttrContext> env,
675 Type site,
676 List<Type> argtypes,
677 List<Type> typeargtypes,
678 Symbol sym,
679 Symbol bestSoFar,
680 boolean allowBoxing,
681 boolean useVarargs,
682 boolean operator) {
683 if (sym.kind == ERR) return bestSoFar;
684 if (!sym.isInheritedIn(site.tsym, types)) return bestSoFar;
685 Assert.check(sym.kind < AMBIGUOUS);
686 try {
687 rawInstantiate(env, site, sym, argtypes, typeargtypes,
688 allowBoxing, useVarargs, Warner.noWarnings);
689 } catch (InapplicableMethodException ex) {
690 switch (bestSoFar.kind) {
691 case ABSENT_MTH:
692 return wrongMethod.setWrongSym(sym, ex.getDiagnostic());
693 case WRONG_MTH:
694 wrongMethods.addCandidate(currentStep, wrongMethod.sym, wrongMethod.explanation);
695 case WRONG_MTHS:
696 return wrongMethods.addCandidate(currentStep, sym, ex.getDiagnostic());
697 default:
698 return bestSoFar;
699 }
700 }
701 if (!isAccessible(env, site, sym)) {
702 return (bestSoFar.kind == ABSENT_MTH)
703 ? new AccessError(env, site, sym)
704 : bestSoFar;
705 }
706 return (bestSoFar.kind > AMBIGUOUS)
707 ? sym
708 : mostSpecific(sym, bestSoFar, env, site,
709 allowBoxing && operator, useVarargs);
710 }
712 /* Return the most specific of the two methods for a call,
713 * given that both are accessible and applicable.
714 * @param m1 A new candidate for most specific.
715 * @param m2 The previous most specific candidate.
716 * @param env The current environment.
717 * @param site The original type from where the selection
718 * takes place.
719 * @param allowBoxing Allow boxing conversions of arguments.
720 * @param useVarargs Box trailing arguments into an array for varargs.
721 */
722 Symbol mostSpecific(Symbol m1,
723 Symbol m2,
724 Env<AttrContext> env,
725 final Type site,
726 boolean allowBoxing,
727 boolean useVarargs) {
728 switch (m2.kind) {
729 case MTH:
730 if (m1 == m2) return m1;
731 boolean m1SignatureMoreSpecific = signatureMoreSpecific(env, site, m1, m2, allowBoxing, useVarargs);
732 boolean m2SignatureMoreSpecific = signatureMoreSpecific(env, site, m2, m1, allowBoxing, useVarargs);
733 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
734 Type mt1 = types.memberType(site, m1);
735 Type mt2 = types.memberType(site, m2);
736 if (!types.overrideEquivalent(mt1, mt2))
737 return ambiguityError(m1, m2);
739 // same signature; select (a) the non-bridge method, or
740 // (b) the one that overrides the other, or (c) the concrete
741 // one, or (d) merge both abstract signatures
742 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE))
743 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
745 // if one overrides or hides the other, use it
746 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
747 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
748 if (types.asSuper(m1Owner.type, m2Owner) != null &&
749 ((m1.owner.flags_field & INTERFACE) == 0 ||
750 (m2.owner.flags_field & INTERFACE) != 0) &&
751 m1.overrides(m2, m1Owner, types, false))
752 return m1;
753 if (types.asSuper(m2Owner.type, m1Owner) != null &&
754 ((m2.owner.flags_field & INTERFACE) == 0 ||
755 (m1.owner.flags_field & INTERFACE) != 0) &&
756 m2.overrides(m1, m2Owner, types, false))
757 return m2;
758 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
759 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
760 if (m1Abstract && !m2Abstract) return m2;
761 if (m2Abstract && !m1Abstract) return m1;
762 // both abstract or both concrete
763 if (!m1Abstract && !m2Abstract)
764 return ambiguityError(m1, m2);
765 // check that both signatures have the same erasure
766 if (!types.isSameTypes(m1.erasure(types).getParameterTypes(),
767 m2.erasure(types).getParameterTypes()))
768 return ambiguityError(m1, m2);
769 // both abstract, neither overridden; merge throws clause and result type
770 Type mst = mostSpecificReturnType(mt1, mt2);
771 if (mst == null) {
772 // Theoretically, this can't happen, but it is possible
773 // due to error recovery or mixing incompatible class files
774 return ambiguityError(m1, m2);
775 }
776 Symbol mostSpecific = mst == mt1 ? m1 : m2;
777 List<Type> allThrown = chk.intersect(mt1.getThrownTypes(), mt2.getThrownTypes());
778 Type newSig = types.createMethodTypeWithThrown(mostSpecific.type, allThrown);
779 MethodSymbol result = new MethodSymbol(
780 mostSpecific.flags(),
781 mostSpecific.name,
782 newSig,
783 mostSpecific.owner) {
784 @Override
785 public MethodSymbol implementation(TypeSymbol origin, Types types, boolean checkResult) {
786 if (origin == site.tsym)
787 return this;
788 else
789 return super.implementation(origin, types, checkResult);
790 }
791 };
792 return result;
793 }
794 if (m1SignatureMoreSpecific) return m1;
795 if (m2SignatureMoreSpecific) return m2;
796 return ambiguityError(m1, m2);
797 case AMBIGUOUS:
798 AmbiguityError e = (AmbiguityError)m2;
799 Symbol err1 = mostSpecific(m1, e.sym, env, site, allowBoxing, useVarargs);
800 Symbol err2 = mostSpecific(m1, e.sym2, env, site, allowBoxing, useVarargs);
801 if (err1 == err2) return err1;
802 if (err1 == e.sym && err2 == e.sym2) return m2;
803 if (err1 instanceof AmbiguityError &&
804 err2 instanceof AmbiguityError &&
805 ((AmbiguityError)err1).sym == ((AmbiguityError)err2).sym)
806 return ambiguityError(m1, m2);
807 else
808 return ambiguityError(err1, err2);
809 default:
810 throw new AssertionError();
811 }
812 }
813 //where
814 private boolean signatureMoreSpecific(Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean allowBoxing, boolean useVarargs) {
815 noteWarner.clear();
816 Type mtype1 = types.memberType(site, adjustVarargs(m1, m2, useVarargs));
817 Type mtype2 = instantiate(env, site, adjustVarargs(m2, m1, useVarargs),
818 types.lowerBoundArgtypes(mtype1), null,
819 allowBoxing, false, noteWarner);
820 return mtype2 != null &&
821 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
822 }
823 //where
824 private Symbol adjustVarargs(Symbol to, Symbol from, boolean useVarargs) {
825 List<Type> fromArgs = from.type.getParameterTypes();
826 List<Type> toArgs = to.type.getParameterTypes();
827 if (useVarargs &&
828 (from.flags() & VARARGS) != 0 &&
829 (to.flags() & VARARGS) != 0) {
830 Type varargsTypeFrom = fromArgs.last();
831 Type varargsTypeTo = toArgs.last();
832 ListBuffer<Type> args = ListBuffer.lb();
833 if (toArgs.length() < fromArgs.length()) {
834 //if we are checking a varargs method 'from' against another varargs
835 //method 'to' (where arity of 'to' < arity of 'from') then expand signature
836 //of 'to' to 'fit' arity of 'from' (this means adding fake formals to 'to'
837 //until 'to' signature has the same arity as 'from')
838 while (fromArgs.head != varargsTypeFrom) {
839 args.append(toArgs.head == varargsTypeTo ? types.elemtype(varargsTypeTo) : toArgs.head);
840 fromArgs = fromArgs.tail;
841 toArgs = toArgs.head == varargsTypeTo ?
842 toArgs :
843 toArgs.tail;
844 }
845 } else {
846 //formal argument list is same as original list where last
847 //argument (array type) is removed
848 args.appendList(toArgs.reverse().tail.reverse());
849 }
850 //append varargs element type as last synthetic formal
851 args.append(types.elemtype(varargsTypeTo));
852 Type mtype = types.createMethodTypeWithParameters(to.type, args.toList());
853 return new MethodSymbol(to.flags_field & ~VARARGS, to.name, mtype, to.owner);
854 } else {
855 return to;
856 }
857 }
858 //where
859 Type mostSpecificReturnType(Type mt1, Type mt2) {
860 Type rt1 = mt1.getReturnType();
861 Type rt2 = mt2.getReturnType();
863 if (mt1.tag == FORALL && mt2.tag == FORALL) {
864 //if both are generic methods, adjust return type ahead of subtyping check
865 rt1 = types.subst(rt1, mt1.getTypeArguments(), mt2.getTypeArguments());
866 }
867 //first use subtyping, then return type substitutability
868 if (types.isSubtype(rt1, rt2)) {
869 return mt1;
870 } else if (types.isSubtype(rt2, rt1)) {
871 return mt2;
872 } else if (types.returnTypeSubstitutable(mt1, mt2)) {
873 return mt1;
874 } else if (types.returnTypeSubstitutable(mt2, mt1)) {
875 return mt2;
876 } else {
877 return null;
878 }
879 }
880 //where
881 Symbol ambiguityError(Symbol m1, Symbol m2) {
882 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
883 return (m1.flags() & CLASH) == 0 ? m1 : m2;
884 } else {
885 return new AmbiguityError(m1, m2);
886 }
887 }
889 /** Find best qualified method matching given name, type and value
890 * arguments.
891 * @param env The current environment.
892 * @param site The original type from where the selection
893 * takes place.
894 * @param name The method's name.
895 * @param argtypes The method's value arguments.
896 * @param typeargtypes The method's type arguments
897 * @param allowBoxing Allow boxing conversions of arguments.
898 * @param useVarargs Box trailing arguments into an array for varargs.
899 */
900 Symbol findMethod(Env<AttrContext> env,
901 Type site,
902 Name name,
903 List<Type> argtypes,
904 List<Type> typeargtypes,
905 boolean allowBoxing,
906 boolean useVarargs,
907 boolean operator) {
908 Symbol bestSoFar = methodNotFound;
909 return findMethod(env,
910 site,
911 name,
912 argtypes,
913 typeargtypes,
914 site.tsym.type,
915 true,
916 bestSoFar,
917 allowBoxing,
918 useVarargs,
919 operator,
920 new HashSet<TypeSymbol>());
921 }
922 // where
923 private Symbol findMethod(Env<AttrContext> env,
924 Type site,
925 Name name,
926 List<Type> argtypes,
927 List<Type> typeargtypes,
928 Type intype,
929 boolean abstractok,
930 Symbol bestSoFar,
931 boolean allowBoxing,
932 boolean useVarargs,
933 boolean operator,
934 Set<TypeSymbol> seen) {
935 for (Type ct = intype; ct.tag == CLASS || ct.tag == TYPEVAR; ct = types.supertype(ct)) {
936 while (ct.tag == TYPEVAR)
937 ct = ct.getUpperBound();
938 ClassSymbol c = (ClassSymbol)ct.tsym;
939 if (!seen.add(c)) return bestSoFar;
940 if ((c.flags() & (ABSTRACT | INTERFACE | ENUM)) == 0)
941 abstractok = false;
942 for (Scope.Entry e = c.members().lookup(name);
943 e.scope != null;
944 e = e.next()) {
945 //- System.out.println(" e " + e.sym);
946 if (e.sym.kind == MTH &&
947 (e.sym.flags_field & SYNTHETIC) == 0) {
948 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
949 e.sym, bestSoFar,
950 allowBoxing,
951 useVarargs,
952 operator);
953 }
954 }
955 if (name == names.init)
956 break;
957 //- System.out.println(" - " + bestSoFar);
958 if (abstractok) {
959 Symbol concrete = methodNotFound;
960 if ((bestSoFar.flags() & ABSTRACT) == 0)
961 concrete = bestSoFar;
962 for (List<Type> l = types.interfaces(c.type);
963 l.nonEmpty();
964 l = l.tail) {
965 bestSoFar = findMethod(env, site, name, argtypes,
966 typeargtypes,
967 l.head, abstractok, bestSoFar,
968 allowBoxing, useVarargs, operator, seen);
969 }
970 if (concrete != bestSoFar &&
971 concrete.kind < ERR && bestSoFar.kind < ERR &&
972 types.isSubSignature(concrete.type, bestSoFar.type))
973 bestSoFar = concrete;
974 }
975 }
976 return bestSoFar;
977 }
979 /** Find unqualified method matching given name, type and value arguments.
980 * @param env The current environment.
981 * @param name The method's name.
982 * @param argtypes The method's value arguments.
983 * @param typeargtypes The method's type arguments.
984 * @param allowBoxing Allow boxing conversions of arguments.
985 * @param useVarargs Box trailing arguments into an array for varargs.
986 */
987 Symbol findFun(Env<AttrContext> env, Name name,
988 List<Type> argtypes, List<Type> typeargtypes,
989 boolean allowBoxing, boolean useVarargs) {
990 Symbol bestSoFar = methodNotFound;
991 Symbol sym;
992 Env<AttrContext> env1 = env;
993 boolean staticOnly = false;
994 while (env1.outer != null) {
995 if (isStatic(env1)) staticOnly = true;
996 sym = findMethod(
997 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
998 allowBoxing, useVarargs, false);
999 if (sym.exists()) {
1000 if (staticOnly &&
1001 sym.kind == MTH &&
1002 sym.owner.kind == TYP &&
1003 (sym.flags() & STATIC) == 0) return new StaticError(sym);
1004 else return sym;
1005 } else if (sym.kind < bestSoFar.kind) {
1006 bestSoFar = sym;
1007 }
1008 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1009 env1 = env1.outer;
1010 }
1012 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1013 typeargtypes, allowBoxing, useVarargs, false);
1014 if (sym.exists())
1015 return sym;
1017 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
1018 for (; e.scope != null; e = e.next()) {
1019 sym = e.sym;
1020 Type origin = e.getOrigin().owner.type;
1021 if (sym.kind == MTH) {
1022 if (e.sym.owner.type != origin)
1023 sym = sym.clone(e.getOrigin().owner);
1024 if (!isAccessible(env, origin, sym))
1025 sym = new AccessError(env, origin, sym);
1026 bestSoFar = selectBest(env, origin,
1027 argtypes, typeargtypes,
1028 sym, bestSoFar,
1029 allowBoxing, useVarargs, false);
1030 }
1031 }
1032 if (bestSoFar.exists())
1033 return bestSoFar;
1035 e = env.toplevel.starImportScope.lookup(name);
1036 for (; e.scope != null; e = e.next()) {
1037 sym = e.sym;
1038 Type origin = e.getOrigin().owner.type;
1039 if (sym.kind == MTH) {
1040 if (e.sym.owner.type != origin)
1041 sym = sym.clone(e.getOrigin().owner);
1042 if (!isAccessible(env, origin, sym))
1043 sym = new AccessError(env, origin, sym);
1044 bestSoFar = selectBest(env, origin,
1045 argtypes, typeargtypes,
1046 sym, bestSoFar,
1047 allowBoxing, useVarargs, false);
1048 }
1049 }
1050 return bestSoFar;
1051 }
1053 /** Load toplevel or member class with given fully qualified name and
1054 * verify that it is accessible.
1055 * @param env The current environment.
1056 * @param name The fully qualified name of the class to be loaded.
1057 */
1058 Symbol loadClass(Env<AttrContext> env, Name name) {
1059 try {
1060 ClassSymbol c = reader.loadClass(name);
1061 return isAccessible(env, c) ? c : new AccessError(c);
1062 } catch (ClassReader.BadClassFile err) {
1063 throw err;
1064 } catch (CompletionFailure ex) {
1065 return typeNotFound;
1066 }
1067 }
1069 /** Find qualified member type.
1070 * @param env The current environment.
1071 * @param site The original type from where the selection takes
1072 * place.
1073 * @param name The type's name.
1074 * @param c The class to search for the member type. This is
1075 * always a superclass or implemented interface of
1076 * site's class.
1077 */
1078 Symbol findMemberType(Env<AttrContext> env,
1079 Type site,
1080 Name name,
1081 TypeSymbol c) {
1082 Symbol bestSoFar = typeNotFound;
1083 Symbol sym;
1084 Scope.Entry e = c.members().lookup(name);
1085 while (e.scope != null) {
1086 if (e.sym.kind == TYP) {
1087 return isAccessible(env, site, e.sym)
1088 ? e.sym
1089 : new AccessError(env, site, e.sym);
1090 }
1091 e = e.next();
1092 }
1093 Type st = types.supertype(c.type);
1094 if (st != null && st.tag == CLASS) {
1095 sym = findMemberType(env, site, name, st.tsym);
1096 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1097 }
1098 for (List<Type> l = types.interfaces(c.type);
1099 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1100 l = l.tail) {
1101 sym = findMemberType(env, site, name, l.head.tsym);
1102 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1103 sym.owner != bestSoFar.owner)
1104 bestSoFar = new AmbiguityError(bestSoFar, sym);
1105 else if (sym.kind < bestSoFar.kind)
1106 bestSoFar = sym;
1107 }
1108 return bestSoFar;
1109 }
1111 /** Find a global type in given scope and load corresponding class.
1112 * @param env The current environment.
1113 * @param scope The scope in which to look for the type.
1114 * @param name The type's name.
1115 */
1116 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
1117 Symbol bestSoFar = typeNotFound;
1118 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
1119 Symbol sym = loadClass(env, e.sym.flatName());
1120 if (bestSoFar.kind == TYP && sym.kind == TYP &&
1121 bestSoFar != sym)
1122 return new AmbiguityError(bestSoFar, sym);
1123 else if (sym.kind < bestSoFar.kind)
1124 bestSoFar = sym;
1125 }
1126 return bestSoFar;
1127 }
1129 /** Find an unqualified type symbol.
1130 * @param env The current environment.
1131 * @param name The type's name.
1132 */
1133 Symbol findType(Env<AttrContext> env, Name name) {
1134 Symbol bestSoFar = typeNotFound;
1135 Symbol sym;
1136 boolean staticOnly = false;
1137 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
1138 if (isStatic(env1)) staticOnly = true;
1139 for (Scope.Entry e = env1.info.scope.lookup(name);
1140 e.scope != null;
1141 e = e.next()) {
1142 if (e.sym.kind == TYP) {
1143 if (staticOnly &&
1144 e.sym.type.tag == TYPEVAR &&
1145 e.sym.owner.kind == TYP) return new StaticError(e.sym);
1146 return e.sym;
1147 }
1148 }
1150 sym = findMemberType(env1, env1.enclClass.sym.type, name,
1151 env1.enclClass.sym);
1152 if (staticOnly && sym.kind == TYP &&
1153 sym.type.tag == CLASS &&
1154 sym.type.getEnclosingType().tag == CLASS &&
1155 env1.enclClass.sym.type.isParameterized() &&
1156 sym.type.getEnclosingType().isParameterized())
1157 return new StaticError(sym);
1158 else if (sym.exists()) return sym;
1159 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1161 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
1162 if ((encl.sym.flags() & STATIC) != 0)
1163 staticOnly = true;
1164 }
1166 if (env.tree.getTag() != JCTree.IMPORT) {
1167 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
1168 if (sym.exists()) return sym;
1169 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1171 sym = findGlobalType(env, env.toplevel.packge.members(), name);
1172 if (sym.exists()) return sym;
1173 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1175 sym = findGlobalType(env, env.toplevel.starImportScope, name);
1176 if (sym.exists()) return sym;
1177 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1178 }
1180 return bestSoFar;
1181 }
1183 /** Find an unqualified identifier which matches a specified kind set.
1184 * @param env The current environment.
1185 * @param name The indentifier's name.
1186 * @param kind Indicates the possible symbol kinds
1187 * (a subset of VAL, TYP, PCK).
1188 */
1189 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
1190 Symbol bestSoFar = typeNotFound;
1191 Symbol sym;
1193 if ((kind & VAR) != 0) {
1194 sym = findVar(env, name);
1195 if (sym.exists()) return sym;
1196 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1197 }
1199 if ((kind & TYP) != 0) {
1200 sym = findType(env, name);
1201 if (sym.exists()) return sym;
1202 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1203 }
1205 if ((kind & PCK) != 0) return reader.enterPackage(name);
1206 else return bestSoFar;
1207 }
1209 /** Find an identifier in a package which matches a specified kind set.
1210 * @param env The current environment.
1211 * @param name The identifier's name.
1212 * @param kind Indicates the possible symbol kinds
1213 * (a nonempty subset of TYP, PCK).
1214 */
1215 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1216 Name name, int kind) {
1217 Name fullname = TypeSymbol.formFullName(name, pck);
1218 Symbol bestSoFar = typeNotFound;
1219 PackageSymbol pack = null;
1220 if ((kind & PCK) != 0) {
1221 pack = reader.enterPackage(fullname);
1222 if (pack.exists()) return pack;
1223 }
1224 if ((kind & TYP) != 0) {
1225 Symbol sym = loadClass(env, fullname);
1226 if (sym.exists()) {
1227 // don't allow programs to use flatnames
1228 if (name == sym.name) return sym;
1229 }
1230 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1231 }
1232 return (pack != null) ? pack : bestSoFar;
1233 }
1235 /** Find an identifier among the members of a given type `site'.
1236 * @param env The current environment.
1237 * @param site The type containing the symbol to be found.
1238 * @param name The identifier's name.
1239 * @param kind Indicates the possible symbol kinds
1240 * (a subset of VAL, TYP).
1241 */
1242 Symbol findIdentInType(Env<AttrContext> env, Type site,
1243 Name name, int kind) {
1244 Symbol bestSoFar = typeNotFound;
1245 Symbol sym;
1246 if ((kind & VAR) != 0) {
1247 sym = findField(env, site, name, site.tsym);
1248 if (sym.exists()) return sym;
1249 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1250 }
1252 if ((kind & TYP) != 0) {
1253 sym = findMemberType(env, site, name, site.tsym);
1254 if (sym.exists()) return sym;
1255 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1256 }
1257 return bestSoFar;
1258 }
1260 /* ***************************************************************************
1261 * Access checking
1262 * The following methods convert ResolveErrors to ErrorSymbols, issuing
1263 * an error message in the process
1264 ****************************************************************************/
1266 /** If `sym' is a bad symbol: report error and return errSymbol
1267 * else pass through unchanged,
1268 * additional arguments duplicate what has been used in trying to find the
1269 * symbol (--> flyweight pattern). This improves performance since we
1270 * expect misses to happen frequently.
1271 *
1272 * @param sym The symbol that was found, or a ResolveError.
1273 * @param pos The position to use for error reporting.
1274 * @param site The original type from where the selection took place.
1275 * @param name The symbol's name.
1276 * @param argtypes The invocation's value arguments,
1277 * if we looked for a method.
1278 * @param typeargtypes The invocation's type arguments,
1279 * if we looked for a method.
1280 */
1281 Symbol access(Symbol sym,
1282 DiagnosticPosition pos,
1283 Symbol location,
1284 Type site,
1285 Name name,
1286 boolean qualified,
1287 List<Type> argtypes,
1288 List<Type> typeargtypes) {
1289 if (sym.kind >= AMBIGUOUS) {
1290 ResolveError errSym = (ResolveError)sym;
1291 if (!site.isErroneous() &&
1292 !Type.isErroneous(argtypes) &&
1293 (typeargtypes==null || !Type.isErroneous(typeargtypes)))
1294 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
1295 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
1296 }
1297 return sym;
1298 }
1300 /** Same as original access(), but without location.
1301 */
1302 Symbol access(Symbol sym,
1303 DiagnosticPosition pos,
1304 Type site,
1305 Name name,
1306 boolean qualified,
1307 List<Type> argtypes,
1308 List<Type> typeargtypes) {
1309 return access(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
1310 }
1312 /** Same as original access(), but without type arguments and arguments.
1313 */
1314 Symbol access(Symbol sym,
1315 DiagnosticPosition pos,
1316 Symbol location,
1317 Type site,
1318 Name name,
1319 boolean qualified) {
1320 if (sym.kind >= AMBIGUOUS)
1321 return access(sym, pos, location, site, name, qualified, List.<Type>nil(), null);
1322 else
1323 return sym;
1324 }
1326 /** Same as original access(), but without location, type arguments and arguments.
1327 */
1328 Symbol access(Symbol sym,
1329 DiagnosticPosition pos,
1330 Type site,
1331 Name name,
1332 boolean qualified) {
1333 return access(sym, pos, site.tsym, site, name, qualified);
1334 }
1336 /** Check that sym is not an abstract method.
1337 */
1338 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
1339 if ((sym.flags() & ABSTRACT) != 0)
1340 log.error(pos, "abstract.cant.be.accessed.directly",
1341 kindName(sym), sym, sym.location());
1342 }
1344 /* ***************************************************************************
1345 * Debugging
1346 ****************************************************************************/
1348 /** print all scopes starting with scope s and proceeding outwards.
1349 * used for debugging.
1350 */
1351 public void printscopes(Scope s) {
1352 while (s != null) {
1353 if (s.owner != null)
1354 System.err.print(s.owner + ": ");
1355 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
1356 if ((e.sym.flags() & ABSTRACT) != 0)
1357 System.err.print("abstract ");
1358 System.err.print(e.sym + " ");
1359 }
1360 System.err.println();
1361 s = s.next;
1362 }
1363 }
1365 void printscopes(Env<AttrContext> env) {
1366 while (env.outer != null) {
1367 System.err.println("------------------------------");
1368 printscopes(env.info.scope);
1369 env = env.outer;
1370 }
1371 }
1373 public void printscopes(Type t) {
1374 while (t.tag == CLASS) {
1375 printscopes(t.tsym.members());
1376 t = types.supertype(t);
1377 }
1378 }
1380 /* ***************************************************************************
1381 * Name resolution
1382 * Naming conventions are as for symbol lookup
1383 * Unlike the find... methods these methods will report access errors
1384 ****************************************************************************/
1386 /** Resolve an unqualified (non-method) identifier.
1387 * @param pos The position to use for error reporting.
1388 * @param env The environment current at the identifier use.
1389 * @param name The identifier's name.
1390 * @param kind The set of admissible symbol kinds for the identifier.
1391 */
1392 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
1393 Name name, int kind) {
1394 return access(
1395 findIdent(env, name, kind),
1396 pos, env.enclClass.sym.type, name, false);
1397 }
1399 /** Resolve an unqualified method identifier.
1400 * @param pos The position to use for error reporting.
1401 * @param env The environment current at the method invocation.
1402 * @param name The identifier's name.
1403 * @param argtypes The types of the invocation's value arguments.
1404 * @param typeargtypes The types of the invocation's type arguments.
1405 */
1406 Symbol resolveMethod(DiagnosticPosition pos,
1407 Env<AttrContext> env,
1408 Name name,
1409 List<Type> argtypes,
1410 List<Type> typeargtypes) {
1411 Symbol sym = startResolution();
1412 List<MethodResolutionPhase> steps = methodResolutionSteps;
1413 while (steps.nonEmpty() &&
1414 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1415 sym.kind >= ERRONEOUS) {
1416 currentStep = steps.head;
1417 sym = findFun(env, name, argtypes, typeargtypes,
1418 steps.head.isBoxingRequired,
1419 env.info.varArgs = steps.head.isVarargsRequired);
1420 methodResolutionCache.put(steps.head, sym);
1421 steps = steps.tail;
1422 }
1423 if (sym.kind >= AMBIGUOUS) {//if nothing is found return the 'first' error
1424 MethodResolutionPhase errPhase =
1425 firstErroneousResolutionPhase();
1426 sym = access(methodResolutionCache.get(errPhase),
1427 pos, env.enclClass.sym.type, name, false, argtypes, typeargtypes);
1428 env.info.varArgs = errPhase.isVarargsRequired;
1429 }
1430 return sym;
1431 }
1433 private Symbol startResolution() {
1434 wrongMethod.clear();
1435 wrongMethods.clear();
1436 return methodNotFound;
1437 }
1439 /** Resolve a qualified method identifier
1440 * @param pos The position to use for error reporting.
1441 * @param env The environment current at the method invocation.
1442 * @param site The type of the qualifying expression, in which
1443 * identifier is searched.
1444 * @param name The identifier's name.
1445 * @param argtypes The types of the invocation's value arguments.
1446 * @param typeargtypes The types of the invocation's type arguments.
1447 */
1448 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
1449 Type site, Name name, List<Type> argtypes,
1450 List<Type> typeargtypes) {
1451 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
1452 }
1453 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
1454 Symbol location, Type site, Name name, List<Type> argtypes,
1455 List<Type> typeargtypes) {
1456 Symbol sym = startResolution();
1457 List<MethodResolutionPhase> steps = methodResolutionSteps;
1458 while (steps.nonEmpty() &&
1459 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1460 sym.kind >= ERRONEOUS) {
1461 currentStep = steps.head;
1462 sym = findMethod(env, site, name, argtypes, typeargtypes,
1463 steps.head.isBoxingRequired(),
1464 env.info.varArgs = steps.head.isVarargsRequired(), false);
1465 methodResolutionCache.put(steps.head, sym);
1466 steps = steps.tail;
1467 }
1468 if (sym.kind >= AMBIGUOUS) {
1469 if (site.tsym.isPolymorphicSignatureGeneric()) {
1470 //polymorphic receiver - synthesize new method symbol
1471 env.info.varArgs = false;
1472 sym = findPolymorphicSignatureInstance(env,
1473 site, name, null, argtypes);
1474 }
1475 else {
1476 //if nothing is found return the 'first' error
1477 MethodResolutionPhase errPhase =
1478 firstErroneousResolutionPhase();
1479 sym = access(methodResolutionCache.get(errPhase),
1480 pos, location, site, name, true, argtypes, typeargtypes);
1481 env.info.varArgs = errPhase.isVarargsRequired;
1482 }
1483 } else if (allowMethodHandles && sym.isPolymorphicSignatureGeneric()) {
1484 //non-instantiated polymorphic signature - synthesize new method symbol
1485 env.info.varArgs = false;
1486 sym = findPolymorphicSignatureInstance(env,
1487 site, name, (MethodSymbol)sym, argtypes);
1488 }
1489 return sym;
1490 }
1492 /** Find or create an implicit method of exactly the given type (after erasure).
1493 * Searches in a side table, not the main scope of the site.
1494 * This emulates the lookup process required by JSR 292 in JVM.
1495 * @param env Attribution environment
1496 * @param site The original type from where the selection takes place.
1497 * @param name The method's name.
1498 * @param spMethod A template for the implicit method, or null.
1499 * @param argtypes The required argument types.
1500 * @param typeargtypes The required type arguments.
1501 */
1502 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env, Type site,
1503 Name name,
1504 MethodSymbol spMethod, // sig. poly. method or null if none
1505 List<Type> argtypes) {
1506 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
1507 site, name, spMethod, argtypes);
1508 long flags = ABSTRACT | HYPOTHETICAL | POLYMORPHIC_SIGNATURE |
1509 (spMethod != null ?
1510 spMethod.flags() & Flags.AccessFlags :
1511 Flags.PUBLIC | Flags.STATIC);
1512 Symbol m = null;
1513 for (Scope.Entry e = polymorphicSignatureScope.lookup(name);
1514 e.scope != null;
1515 e = e.next()) {
1516 Symbol sym = e.sym;
1517 if (types.isSameType(mtype, sym.type) &&
1518 (sym.flags() & Flags.STATIC) == (flags & Flags.STATIC) &&
1519 types.isSameType(sym.owner.type, site)) {
1520 m = sym;
1521 break;
1522 }
1523 }
1524 if (m == null) {
1525 // create the desired method
1526 m = new MethodSymbol(flags, name, mtype, site.tsym);
1527 polymorphicSignatureScope.enter(m);
1528 }
1529 return m;
1530 }
1532 /** Resolve a qualified method identifier, throw a fatal error if not
1533 * found.
1534 * @param pos The position to use for error reporting.
1535 * @param env The environment current at the method invocation.
1536 * @param site The type of the qualifying expression, in which
1537 * identifier is searched.
1538 * @param name The identifier's name.
1539 * @param argtypes The types of the invocation's value arguments.
1540 * @param typeargtypes The types of the invocation's type arguments.
1541 */
1542 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
1543 Type site, Name name,
1544 List<Type> argtypes,
1545 List<Type> typeargtypes) {
1546 Symbol sym = resolveQualifiedMethod(
1547 pos, env, site.tsym, site, name, argtypes, typeargtypes);
1548 if (sym.kind == MTH) return (MethodSymbol)sym;
1549 else throw new FatalError(
1550 diags.fragment("fatal.err.cant.locate.meth",
1551 name));
1552 }
1554 /** Resolve constructor.
1555 * @param pos The position to use for error reporting.
1556 * @param env The environment current at the constructor invocation.
1557 * @param site The type of class for which a constructor is searched.
1558 * @param argtypes The types of the constructor invocation's value
1559 * arguments.
1560 * @param typeargtypes The types of the constructor invocation's type
1561 * arguments.
1562 */
1563 Symbol resolveConstructor(DiagnosticPosition pos,
1564 Env<AttrContext> env,
1565 Type site,
1566 List<Type> argtypes,
1567 List<Type> typeargtypes) {
1568 Symbol sym = startResolution();
1569 List<MethodResolutionPhase> steps = methodResolutionSteps;
1570 while (steps.nonEmpty() &&
1571 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1572 sym.kind >= ERRONEOUS) {
1573 currentStep = steps.head;
1574 sym = resolveConstructor(pos, env, site, argtypes, typeargtypes,
1575 steps.head.isBoxingRequired(),
1576 env.info.varArgs = steps.head.isVarargsRequired());
1577 methodResolutionCache.put(steps.head, sym);
1578 steps = steps.tail;
1579 }
1580 if (sym.kind >= AMBIGUOUS) {//if nothing is found return the 'first' error
1581 MethodResolutionPhase errPhase = firstErroneousResolutionPhase();
1582 sym = access(methodResolutionCache.get(errPhase),
1583 pos, site, names.init, true, argtypes, typeargtypes);
1584 env.info.varArgs = errPhase.isVarargsRequired();
1585 }
1586 return sym;
1587 }
1589 /** Resolve constructor using diamond inference.
1590 * @param pos The position to use for error reporting.
1591 * @param env The environment current at the constructor invocation.
1592 * @param site The type of class for which a constructor is searched.
1593 * The scope of this class has been touched in attribution.
1594 * @param argtypes The types of the constructor invocation's value
1595 * arguments.
1596 * @param typeargtypes The types of the constructor invocation's type
1597 * arguments.
1598 */
1599 Symbol resolveDiamond(DiagnosticPosition pos,
1600 Env<AttrContext> env,
1601 Type site,
1602 List<Type> argtypes,
1603 List<Type> typeargtypes) {
1604 Symbol sym = startResolution();
1605 List<MethodResolutionPhase> steps = methodResolutionSteps;
1606 while (steps.nonEmpty() &&
1607 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1608 sym.kind >= ERRONEOUS) {
1609 currentStep = steps.head;
1610 sym = resolveConstructor(pos, env, site, argtypes, typeargtypes,
1611 steps.head.isBoxingRequired(),
1612 env.info.varArgs = steps.head.isVarargsRequired());
1613 methodResolutionCache.put(steps.head, sym);
1614 steps = steps.tail;
1615 }
1616 if (sym.kind >= AMBIGUOUS) {
1617 final JCDiagnostic details = sym.kind == WRONG_MTH ?
1618 ((InapplicableSymbolError)sym).explanation :
1619 null;
1620 Symbol errSym = new ResolveError(WRONG_MTH, "diamond error") {
1621 @Override
1622 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
1623 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
1624 String key = details == null ?
1625 "cant.apply.diamond" :
1626 "cant.apply.diamond.1";
1627 return diags.create(dkind, log.currentSource(), pos, key,
1628 diags.fragment("diamond", site.tsym), details);
1629 }
1630 };
1631 MethodResolutionPhase errPhase = firstErroneousResolutionPhase();
1632 sym = access(errSym, pos, site, names.init, true, argtypes, typeargtypes);
1633 env.info.varArgs = errPhase.isVarargsRequired();
1634 }
1635 return sym;
1636 }
1638 /** Resolve constructor.
1639 * @param pos The position to use for error reporting.
1640 * @param env The environment current at the constructor invocation.
1641 * @param site The type of class for which a constructor is searched.
1642 * @param argtypes The types of the constructor invocation's value
1643 * arguments.
1644 * @param typeargtypes The types of the constructor invocation's type
1645 * arguments.
1646 * @param allowBoxing Allow boxing and varargs conversions.
1647 * @param useVarargs Box trailing arguments into an array for varargs.
1648 */
1649 Symbol resolveConstructor(DiagnosticPosition pos, Env<AttrContext> env,
1650 Type site, List<Type> argtypes,
1651 List<Type> typeargtypes,
1652 boolean allowBoxing,
1653 boolean useVarargs) {
1654 Symbol sym = findMethod(env, site,
1655 names.init, argtypes,
1656 typeargtypes, allowBoxing,
1657 useVarargs, false);
1658 chk.checkDeprecated(pos, env.info.scope.owner, sym);
1659 return sym;
1660 }
1662 /** Resolve a constructor, throw a fatal error if not found.
1663 * @param pos The position to use for error reporting.
1664 * @param env The environment current at the method invocation.
1665 * @param site The type to be constructed.
1666 * @param argtypes The types of the invocation's value arguments.
1667 * @param typeargtypes The types of the invocation's type arguments.
1668 */
1669 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
1670 Type site,
1671 List<Type> argtypes,
1672 List<Type> typeargtypes) {
1673 Symbol sym = resolveConstructor(
1674 pos, env, site, argtypes, typeargtypes);
1675 if (sym.kind == MTH) return (MethodSymbol)sym;
1676 else throw new FatalError(
1677 diags.fragment("fatal.err.cant.locate.ctor", site));
1678 }
1680 /** Resolve operator.
1681 * @param pos The position to use for error reporting.
1682 * @param optag The tag of the operation tree.
1683 * @param env The environment current at the operation.
1684 * @param argtypes The types of the operands.
1685 */
1686 Symbol resolveOperator(DiagnosticPosition pos, int optag,
1687 Env<AttrContext> env, List<Type> argtypes) {
1688 Name name = treeinfo.operatorName(optag);
1689 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
1690 null, false, false, true);
1691 if (boxingEnabled && sym.kind >= WRONG_MTHS)
1692 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1693 null, true, false, true);
1694 return access(sym, pos, env.enclClass.sym.type, name,
1695 false, argtypes, null);
1696 }
1698 /** Resolve operator.
1699 * @param pos The position to use for error reporting.
1700 * @param optag The tag of the operation tree.
1701 * @param env The environment current at the operation.
1702 * @param arg The type of the operand.
1703 */
1704 Symbol resolveUnaryOperator(DiagnosticPosition pos, int optag, Env<AttrContext> env, Type arg) {
1705 return resolveOperator(pos, optag, env, List.of(arg));
1706 }
1708 /** Resolve binary operator.
1709 * @param pos The position to use for error reporting.
1710 * @param optag The tag of the operation tree.
1711 * @param env The environment current at the operation.
1712 * @param left The types of the left operand.
1713 * @param right The types of the right operand.
1714 */
1715 Symbol resolveBinaryOperator(DiagnosticPosition pos,
1716 int optag,
1717 Env<AttrContext> env,
1718 Type left,
1719 Type right) {
1720 return resolveOperator(pos, optag, env, List.of(left, right));
1721 }
1723 /**
1724 * Resolve `c.name' where name == this or name == super.
1725 * @param pos The position to use for error reporting.
1726 * @param env The environment current at the expression.
1727 * @param c The qualifier.
1728 * @param name The identifier's name.
1729 */
1730 Symbol resolveSelf(DiagnosticPosition pos,
1731 Env<AttrContext> env,
1732 TypeSymbol c,
1733 Name name) {
1734 Env<AttrContext> env1 = env;
1735 boolean staticOnly = false;
1736 while (env1.outer != null) {
1737 if (isStatic(env1)) staticOnly = true;
1738 if (env1.enclClass.sym == c) {
1739 Symbol sym = env1.info.scope.lookup(name).sym;
1740 if (sym != null) {
1741 if (staticOnly) sym = new StaticError(sym);
1742 return access(sym, pos, env.enclClass.sym.type,
1743 name, true);
1744 }
1745 }
1746 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1747 env1 = env1.outer;
1748 }
1749 log.error(pos, "not.encl.class", c);
1750 return syms.errSymbol;
1751 }
1753 /**
1754 * Resolve `c.this' for an enclosing class c that contains the
1755 * named member.
1756 * @param pos The position to use for error reporting.
1757 * @param env The environment current at the expression.
1758 * @param member The member that must be contained in the result.
1759 */
1760 Symbol resolveSelfContaining(DiagnosticPosition pos,
1761 Env<AttrContext> env,
1762 Symbol member,
1763 boolean isSuperCall) {
1764 Name name = names._this;
1765 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
1766 boolean staticOnly = false;
1767 if (env1 != null) {
1768 while (env1 != null && env1.outer != null) {
1769 if (isStatic(env1)) staticOnly = true;
1770 if (env1.enclClass.sym.isSubClass(member.owner, types)) {
1771 Symbol sym = env1.info.scope.lookup(name).sym;
1772 if (sym != null) {
1773 if (staticOnly) sym = new StaticError(sym);
1774 return access(sym, pos, env.enclClass.sym.type,
1775 name, true);
1776 }
1777 }
1778 if ((env1.enclClass.sym.flags() & STATIC) != 0)
1779 staticOnly = true;
1780 env1 = env1.outer;
1781 }
1782 }
1783 log.error(pos, "encl.class.required", member);
1784 return syms.errSymbol;
1785 }
1787 /**
1788 * Resolve an appropriate implicit this instance for t's container.
1789 * JLS 8.8.5.1 and 15.9.2
1790 */
1791 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
1792 return resolveImplicitThis(pos, env, t, false);
1793 }
1795 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
1796 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
1797 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
1798 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
1799 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
1800 log.error(pos, "cant.ref.before.ctor.called", "this");
1801 return thisType;
1802 }
1804 /* ***************************************************************************
1805 * ResolveError classes, indicating error situations when accessing symbols
1806 ****************************************************************************/
1808 public void logAccessError(Env<AttrContext> env, JCTree tree, Type type) {
1809 AccessError error = new AccessError(env, type.getEnclosingType(), type.tsym);
1810 logResolveError(error, tree.pos(), type.getEnclosingType().tsym, type.getEnclosingType(), null, null, null);
1811 }
1812 //where
1813 private void logResolveError(ResolveError error,
1814 DiagnosticPosition pos,
1815 Symbol location,
1816 Type site,
1817 Name name,
1818 List<Type> argtypes,
1819 List<Type> typeargtypes) {
1820 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
1821 pos, location, site, name, argtypes, typeargtypes);
1822 if (d != null) {
1823 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
1824 log.report(d);
1825 }
1826 }
1828 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
1830 public Object methodArguments(List<Type> argtypes) {
1831 return argtypes.isEmpty() ? noArgs : argtypes;
1832 }
1834 /**
1835 * Root class for resolution errors. Subclass of ResolveError
1836 * represent a different kinds of resolution error - as such they must
1837 * specify how they map into concrete compiler diagnostics.
1838 */
1839 private abstract class ResolveError extends Symbol {
1841 /** The name of the kind of error, for debugging only. */
1842 final String debugName;
1844 ResolveError(int kind, String debugName) {
1845 super(kind, 0, null, null, null);
1846 this.debugName = debugName;
1847 }
1849 @Override
1850 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
1851 throw new AssertionError();
1852 }
1854 @Override
1855 public String toString() {
1856 return debugName;
1857 }
1859 @Override
1860 public boolean exists() {
1861 return false;
1862 }
1864 /**
1865 * Create an external representation for this erroneous symbol to be
1866 * used during attribution - by default this returns the symbol of a
1867 * brand new error type which stores the original type found
1868 * during resolution.
1869 *
1870 * @param name the name used during resolution
1871 * @param location the location from which the symbol is accessed
1872 */
1873 protected Symbol access(Name name, TypeSymbol location) {
1874 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
1875 }
1877 /**
1878 * Create a diagnostic representing this resolution error.
1879 *
1880 * @param dkind The kind of the diagnostic to be created (e.g error).
1881 * @param pos The position to be used for error reporting.
1882 * @param site The original type from where the selection took place.
1883 * @param name The name of the symbol to be resolved.
1884 * @param argtypes The invocation's value arguments,
1885 * if we looked for a method.
1886 * @param typeargtypes The invocation's type arguments,
1887 * if we looked for a method.
1888 */
1889 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
1890 DiagnosticPosition pos,
1891 Symbol location,
1892 Type site,
1893 Name name,
1894 List<Type> argtypes,
1895 List<Type> typeargtypes);
1897 /**
1898 * A name designates an operator if it consists
1899 * of a non-empty sequence of operator symbols +-~!/*%&|^<>=
1900 */
1901 boolean isOperator(Name name) {
1902 int i = 0;
1903 while (i < name.getByteLength() &&
1904 "+-~!*/%&|^<>=".indexOf(name.getByteAt(i)) >= 0) i++;
1905 return i > 0 && i == name.getByteLength();
1906 }
1907 }
1909 /**
1910 * This class is the root class of all resolution errors caused by
1911 * an invalid symbol being found during resolution.
1912 */
1913 abstract class InvalidSymbolError extends ResolveError {
1915 /** The invalid symbol found during resolution */
1916 Symbol sym;
1918 InvalidSymbolError(int kind, Symbol sym, String debugName) {
1919 super(kind, debugName);
1920 this.sym = sym;
1921 }
1923 @Override
1924 public boolean exists() {
1925 return true;
1926 }
1928 @Override
1929 public String toString() {
1930 return super.toString() + " wrongSym=" + sym;
1931 }
1933 @Override
1934 public Symbol access(Name name, TypeSymbol location) {
1935 if (sym.kind >= AMBIGUOUS)
1936 return ((ResolveError)sym).access(name, location);
1937 else if ((sym.kind & ERRONEOUS) == 0 && (sym.kind & TYP) != 0)
1938 return types.createErrorType(name, location, sym.type).tsym;
1939 else
1940 return sym;
1941 }
1942 }
1944 /**
1945 * InvalidSymbolError error class indicating that a symbol matching a
1946 * given name does not exists in a given site.
1947 */
1948 class SymbolNotFoundError extends ResolveError {
1950 SymbolNotFoundError(int kind) {
1951 super(kind, "symbol not found error");
1952 }
1954 @Override
1955 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
1956 DiagnosticPosition pos,
1957 Symbol location,
1958 Type site,
1959 Name name,
1960 List<Type> argtypes,
1961 List<Type> typeargtypes) {
1962 argtypes = argtypes == null ? List.<Type>nil() : argtypes;
1963 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes;
1964 if (name == names.error)
1965 return null;
1967 if (isOperator(name)) {
1968 boolean isUnaryOp = argtypes.size() == 1;
1969 String key = argtypes.size() == 1 ?
1970 "operator.cant.be.applied" :
1971 "operator.cant.be.applied.1";
1972 Type first = argtypes.head;
1973 Type second = !isUnaryOp ? argtypes.tail.head : null;
1974 return diags.create(dkind, log.currentSource(), pos,
1975 key, name, first, second);
1976 }
1977 boolean hasLocation = false;
1978 if (location == null) {
1979 location = site.tsym;
1980 }
1981 if (!location.name.isEmpty()) {
1982 if (location.kind == PCK && !site.tsym.exists()) {
1983 return diags.create(dkind, log.currentSource(), pos,
1984 "doesnt.exist", location);
1985 }
1986 hasLocation = !location.name.equals(names._this) &&
1987 !location.name.equals(names._super);
1988 }
1989 boolean isConstructor = kind == ABSENT_MTH &&
1990 name == names.table.names.init;
1991 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : absentKind(kind);
1992 Name idname = isConstructor ? site.tsym.name : name;
1993 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
1994 if (hasLocation) {
1995 return diags.create(dkind, log.currentSource(), pos,
1996 errKey, kindname, idname, //symbol kindname, name
1997 typeargtypes, argtypes, //type parameters and arguments (if any)
1998 getLocationDiag(location, site)); //location kindname, type
1999 }
2000 else {
2001 return diags.create(dkind, log.currentSource(), pos,
2002 errKey, kindname, idname, //symbol kindname, name
2003 typeargtypes, argtypes); //type parameters and arguments (if any)
2004 }
2005 }
2006 //where
2007 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
2008 String key = "cant.resolve";
2009 String suffix = hasLocation ? ".location" : "";
2010 switch (kindname) {
2011 case METHOD:
2012 case CONSTRUCTOR: {
2013 suffix += ".args";
2014 suffix += hasTypeArgs ? ".params" : "";
2015 }
2016 }
2017 return key + suffix;
2018 }
2019 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
2020 if (location.kind == VAR) {
2021 return diags.fragment("location.1",
2022 kindName(location),
2023 location,
2024 location.type);
2025 } else {
2026 return diags.fragment("location",
2027 typeKindName(site),
2028 site,
2029 null);
2030 }
2031 }
2032 }
2034 /**
2035 * InvalidSymbolError error class indicating that a given symbol
2036 * (either a method, a constructor or an operand) is not applicable
2037 * given an actual arguments/type argument list.
2038 */
2039 class InapplicableSymbolError extends InvalidSymbolError {
2041 /** An auxiliary explanation set in case of instantiation errors. */
2042 JCDiagnostic explanation;
2044 InapplicableSymbolError(Symbol sym) {
2045 super(WRONG_MTH, sym, "inapplicable symbol error");
2046 }
2048 /** Update sym and explanation and return this.
2049 */
2050 InapplicableSymbolError setWrongSym(Symbol sym, JCDiagnostic explanation) {
2051 this.sym = sym;
2052 if (this.sym == sym && explanation != null)
2053 this.explanation = explanation; //update the details
2054 return this;
2055 }
2057 /** Update sym and return this.
2058 */
2059 InapplicableSymbolError setWrongSym(Symbol sym) {
2060 this.sym = sym;
2061 return this;
2062 }
2064 @Override
2065 public String toString() {
2066 return super.toString() + " explanation=" + explanation;
2067 }
2069 @Override
2070 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2071 DiagnosticPosition pos,
2072 Symbol location,
2073 Type site,
2074 Name name,
2075 List<Type> argtypes,
2076 List<Type> typeargtypes) {
2077 if (name == names.error)
2078 return null;
2080 if (isOperator(name)) {
2081 boolean isUnaryOp = argtypes.size() == 1;
2082 String key = argtypes.size() == 1 ?
2083 "operator.cant.be.applied" :
2084 "operator.cant.be.applied.1";
2085 Type first = argtypes.head;
2086 Type second = !isUnaryOp ? argtypes.tail.head : null;
2087 return diags.create(dkind, log.currentSource(), pos,
2088 key, name, first, second);
2089 }
2090 else {
2091 Symbol ws = sym.asMemberOf(site, types);
2092 return diags.create(dkind, log.currentSource(), pos,
2093 "cant.apply.symbol" + (explanation != null ? ".1" : ""),
2094 kindName(ws),
2095 ws.name == names.init ? ws.owner.name : ws.name,
2096 methodArguments(ws.type.getParameterTypes()),
2097 methodArguments(argtypes),
2098 kindName(ws.owner),
2099 ws.owner.type,
2100 explanation);
2101 }
2102 }
2104 void clear() {
2105 explanation = null;
2106 }
2108 @Override
2109 public Symbol access(Name name, TypeSymbol location) {
2110 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
2111 }
2112 }
2114 /**
2115 * ResolveError error class indicating that a set of symbols
2116 * (either methods, constructors or operands) is not applicable
2117 * given an actual arguments/type argument list.
2118 */
2119 class InapplicableSymbolsError extends ResolveError {
2121 private List<Candidate> candidates = List.nil();
2123 InapplicableSymbolsError(Symbol sym) {
2124 super(WRONG_MTHS, "inapplicable symbols");
2125 }
2127 @Override
2128 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2129 DiagnosticPosition pos,
2130 Symbol location,
2131 Type site,
2132 Name name,
2133 List<Type> argtypes,
2134 List<Type> typeargtypes) {
2135 if (candidates.nonEmpty()) {
2136 JCDiagnostic err = diags.create(dkind,
2137 log.currentSource(),
2138 pos,
2139 "cant.apply.symbols",
2140 name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
2141 getName(),
2142 argtypes);
2143 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(site));
2144 } else {
2145 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
2146 location, site, name, argtypes, typeargtypes);
2147 }
2148 }
2150 //where
2151 List<JCDiagnostic> candidateDetails(Type site) {
2152 List<JCDiagnostic> details = List.nil();
2153 for (Candidate c : candidates)
2154 details = details.prepend(c.getDiagnostic(site));
2155 return details.reverse();
2156 }
2158 Symbol addCandidate(MethodResolutionPhase currentStep, Symbol sym, JCDiagnostic details) {
2159 Candidate c = new Candidate(currentStep, sym, details);
2160 if (c.isValid() && !candidates.contains(c))
2161 candidates = candidates.append(c);
2162 return this;
2163 }
2165 void clear() {
2166 candidates = List.nil();
2167 }
2169 private Name getName() {
2170 Symbol sym = candidates.head.sym;
2171 return sym.name == names.init ?
2172 sym.owner.name :
2173 sym.name;
2174 }
2176 private class Candidate {
2178 final MethodResolutionPhase step;
2179 final Symbol sym;
2180 final JCDiagnostic details;
2182 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details) {
2183 this.step = step;
2184 this.sym = sym;
2185 this.details = details;
2186 }
2188 JCDiagnostic getDiagnostic(Type site) {
2189 return diags.fragment("inapplicable.method",
2190 Kinds.kindName(sym),
2191 sym.location(site, types),
2192 sym.asMemberOf(site, types),
2193 details);
2194 }
2196 @Override
2197 public boolean equals(Object o) {
2198 if (o instanceof Candidate) {
2199 Symbol s1 = this.sym;
2200 Symbol s2 = ((Candidate)o).sym;
2201 if ((s1 != s2 &&
2202 (s1.overrides(s2, s1.owner.type.tsym, types, false) ||
2203 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) ||
2204 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner))
2205 return true;
2206 }
2207 return false;
2208 }
2210 boolean isValid() {
2211 return (((sym.flags() & VARARGS) != 0 && step == VARARITY) ||
2212 (sym.flags() & VARARGS) == 0 && step == (boxingEnabled ? BOX : BASIC));
2213 }
2214 }
2215 }
2217 /**
2218 * An InvalidSymbolError error class indicating that a symbol is not
2219 * accessible from a given site
2220 */
2221 class AccessError extends InvalidSymbolError {
2223 private Env<AttrContext> env;
2224 private Type site;
2226 AccessError(Symbol sym) {
2227 this(null, null, sym);
2228 }
2230 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
2231 super(HIDDEN, sym, "access error");
2232 this.env = env;
2233 this.site = site;
2234 if (debugResolve)
2235 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
2236 }
2238 @Override
2239 public boolean exists() {
2240 return false;
2241 }
2243 @Override
2244 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2245 DiagnosticPosition pos,
2246 Symbol location,
2247 Type site,
2248 Name name,
2249 List<Type> argtypes,
2250 List<Type> typeargtypes) {
2251 if (sym.owner.type.tag == ERROR)
2252 return null;
2254 if (sym.name == names.init && sym.owner != site.tsym) {
2255 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
2256 pos, location, site, name, argtypes, typeargtypes);
2257 }
2258 else if ((sym.flags() & PUBLIC) != 0
2259 || (env != null && this.site != null
2260 && !isAccessible(env, this.site))) {
2261 return diags.create(dkind, log.currentSource(),
2262 pos, "not.def.access.class.intf.cant.access",
2263 sym, sym.location());
2264 }
2265 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
2266 return diags.create(dkind, log.currentSource(),
2267 pos, "report.access", sym,
2268 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
2269 sym.location());
2270 }
2271 else {
2272 return diags.create(dkind, log.currentSource(),
2273 pos, "not.def.public.cant.access", sym, sym.location());
2274 }
2275 }
2276 }
2278 /**
2279 * InvalidSymbolError error class indicating that an instance member
2280 * has erroneously been accessed from a static context.
2281 */
2282 class StaticError extends InvalidSymbolError {
2284 StaticError(Symbol sym) {
2285 super(STATICERR, sym, "static error");
2286 }
2288 @Override
2289 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2290 DiagnosticPosition pos,
2291 Symbol location,
2292 Type site,
2293 Name name,
2294 List<Type> argtypes,
2295 List<Type> typeargtypes) {
2296 Symbol errSym = ((sym.kind == TYP && sym.type.tag == CLASS)
2297 ? types.erasure(sym.type).tsym
2298 : sym);
2299 return diags.create(dkind, log.currentSource(), pos,
2300 "non-static.cant.be.ref", kindName(sym), errSym);
2301 }
2302 }
2304 /**
2305 * InvalidSymbolError error class indicating that a pair of symbols
2306 * (either methods, constructors or operands) are ambiguous
2307 * given an actual arguments/type argument list.
2308 */
2309 class AmbiguityError extends InvalidSymbolError {
2311 /** The other maximally specific symbol */
2312 Symbol sym2;
2314 AmbiguityError(Symbol sym1, Symbol sym2) {
2315 super(AMBIGUOUS, sym1, "ambiguity error");
2316 this.sym2 = sym2;
2317 }
2319 @Override
2320 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2321 DiagnosticPosition pos,
2322 Symbol location,
2323 Type site,
2324 Name name,
2325 List<Type> argtypes,
2326 List<Type> typeargtypes) {
2327 AmbiguityError pair = this;
2328 while (true) {
2329 if (pair.sym.kind == AMBIGUOUS)
2330 pair = (AmbiguityError)pair.sym;
2331 else if (pair.sym2.kind == AMBIGUOUS)
2332 pair = (AmbiguityError)pair.sym2;
2333 else break;
2334 }
2335 Name sname = pair.sym.name;
2336 if (sname == names.init) sname = pair.sym.owner.name;
2337 return diags.create(dkind, log.currentSource(),
2338 pos, "ref.ambiguous", sname,
2339 kindName(pair.sym),
2340 pair.sym,
2341 pair.sym.location(site, types),
2342 kindName(pair.sym2),
2343 pair.sym2,
2344 pair.sym2.location(site, types));
2345 }
2346 }
2348 enum MethodResolutionPhase {
2349 BASIC(false, false),
2350 BOX(true, false),
2351 VARARITY(true, true);
2353 boolean isBoxingRequired;
2354 boolean isVarargsRequired;
2356 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
2357 this.isBoxingRequired = isBoxingRequired;
2358 this.isVarargsRequired = isVarargsRequired;
2359 }
2361 public boolean isBoxingRequired() {
2362 return isBoxingRequired;
2363 }
2365 public boolean isVarargsRequired() {
2366 return isVarargsRequired;
2367 }
2369 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
2370 return (varargsEnabled || !isVarargsRequired) &&
2371 (boxingEnabled || !isBoxingRequired);
2372 }
2373 }
2375 private Map<MethodResolutionPhase, Symbol> methodResolutionCache =
2376 new HashMap<MethodResolutionPhase, Symbol>(MethodResolutionPhase.values().length);
2378 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
2380 private MethodResolutionPhase currentStep = null;
2382 private MethodResolutionPhase firstErroneousResolutionPhase() {
2383 MethodResolutionPhase bestSoFar = BASIC;
2384 Symbol sym = methodNotFound;
2385 List<MethodResolutionPhase> steps = methodResolutionSteps;
2386 while (steps.nonEmpty() &&
2387 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
2388 sym.kind >= WRONG_MTHS) {
2389 sym = methodResolutionCache.get(steps.head);
2390 bestSoFar = steps.head;
2391 steps = steps.tail;
2392 }
2393 return bestSoFar;
2394 }
2395 }
