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src/share/classes/com/sun/tools/javac/comp/Resolve.java@a2d422d480cb
src/share/classes/com/sun/tools/javac/comp/Resolve.java
Wed, 11 May 2011 13:10:57 +0200
- author
- mcimadamore
- date
- Wed, 11 May 2011 13:10:57 +0200
- changeset 1006
- a2d422d480cb
- parent 972
- 694ff82ca68e
- child 1059
- 0b5beb9562c6
- permissions
- -rw-r--r--
7042566: Regression: new ambiguity between varargs method
Summary: Erroneous ambiguity error when choosing most specific varargs method
Reviewed-by: jjg
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 Symbol mostSpecific;
771 if (types.returnTypeSubstitutable(mt1, mt2))
772 mostSpecific = m1;
773 else if (types.returnTypeSubstitutable(mt2, mt1))
774 mostSpecific = m2;
775 else {
776 // Theoretically, this can't happen, but it is possible
777 // due to error recovery or mixing incompatible class files
778 return ambiguityError(m1, m2);
779 }
780 List<Type> allThrown = chk.intersect(mt1.getThrownTypes(), mt2.getThrownTypes());
781 Type newSig = types.createMethodTypeWithThrown(mostSpecific.type, allThrown);
782 MethodSymbol result = new MethodSymbol(
783 mostSpecific.flags(),
784 mostSpecific.name,
785 newSig,
786 mostSpecific.owner) {
787 @Override
788 public MethodSymbol implementation(TypeSymbol origin, Types types, boolean checkResult) {
789 if (origin == site.tsym)
790 return this;
791 else
792 return super.implementation(origin, types, checkResult);
793 }
794 };
795 return result;
796 }
797 if (m1SignatureMoreSpecific) return m1;
798 if (m2SignatureMoreSpecific) return m2;
799 return ambiguityError(m1, m2);
800 case AMBIGUOUS:
801 AmbiguityError e = (AmbiguityError)m2;
802 Symbol err1 = mostSpecific(m1, e.sym, env, site, allowBoxing, useVarargs);
803 Symbol err2 = mostSpecific(m1, e.sym2, env, site, allowBoxing, useVarargs);
804 if (err1 == err2) return err1;
805 if (err1 == e.sym && err2 == e.sym2) return m2;
806 if (err1 instanceof AmbiguityError &&
807 err2 instanceof AmbiguityError &&
808 ((AmbiguityError)err1).sym == ((AmbiguityError)err2).sym)
809 return ambiguityError(m1, m2);
810 else
811 return ambiguityError(err1, err2);
812 default:
813 throw new AssertionError();
814 }
815 }
816 //where
817 private boolean signatureMoreSpecific(Env<AttrContext> env, Type site, Symbol m1, Symbol m2, boolean allowBoxing, boolean useVarargs) {
818 noteWarner.clear();
819 Type mtype1 = types.memberType(site, adjustVarargs(m1, m2, useVarargs));
820 Type mtype2 = instantiate(env, site, adjustVarargs(m2, m1, useVarargs),
821 types.lowerBoundArgtypes(mtype1), null,
822 allowBoxing, false, noteWarner);
823 return mtype2 != null &&
824 !noteWarner.hasLint(Lint.LintCategory.UNCHECKED);
825 }
826 //where
827 private Symbol adjustVarargs(Symbol to, Symbol from, boolean useVarargs) {
828 List<Type> fromArgs = from.type.getParameterTypes();
829 List<Type> toArgs = to.type.getParameterTypes();
830 if (useVarargs &&
831 (from.flags() & VARARGS) != 0 &&
832 (to.flags() & VARARGS) != 0) {
833 Type varargsTypeFrom = fromArgs.last();
834 Type varargsTypeTo = toArgs.last();
835 ListBuffer<Type> args = ListBuffer.lb();
836 if (toArgs.length() < fromArgs.length()) {
837 //if we are checking a varargs method 'from' against another varargs
838 //method 'to' (where arity of 'to' < arity of 'from') then expand signature
839 //of 'to' to 'fit' arity of 'from' (this means adding fake formals to 'to'
840 //until 'to' signature has the same arity as 'from')
841 while (fromArgs.head != varargsTypeFrom) {
842 args.append(toArgs.head == varargsTypeTo ? types.elemtype(varargsTypeTo) : toArgs.head);
843 fromArgs = fromArgs.tail;
844 toArgs = toArgs.head == varargsTypeTo ?
845 toArgs :
846 toArgs.tail;
847 }
848 } else {
849 //formal argument list is same as original list where last
850 //argument (array type) is removed
851 args.appendList(toArgs.reverse().tail.reverse());
852 }
853 //append varargs element type as last synthetic formal
854 args.append(types.elemtype(varargsTypeTo));
855 Type mtype = types.createMethodTypeWithParameters(to.type, args.toList());
856 return new MethodSymbol(to.flags_field & ~VARARGS, to.name, mtype, to.owner);
857 } else {
858 return to;
859 }
860 }
861 //where
862 Symbol ambiguityError(Symbol m1, Symbol m2) {
863 if (((m1.flags() | m2.flags()) & CLASH) != 0) {
864 return (m1.flags() & CLASH) == 0 ? m1 : m2;
865 } else {
866 return new AmbiguityError(m1, m2);
867 }
868 }
870 /** Find best qualified method matching given name, type and value
871 * arguments.
872 * @param env The current environment.
873 * @param site The original type from where the selection
874 * takes place.
875 * @param name The method's name.
876 * @param argtypes The method's value arguments.
877 * @param typeargtypes The method's type arguments
878 * @param allowBoxing Allow boxing conversions of arguments.
879 * @param useVarargs Box trailing arguments into an array for varargs.
880 */
881 Symbol findMethod(Env<AttrContext> env,
882 Type site,
883 Name name,
884 List<Type> argtypes,
885 List<Type> typeargtypes,
886 boolean allowBoxing,
887 boolean useVarargs,
888 boolean operator) {
889 Symbol bestSoFar = methodNotFound;
890 return findMethod(env,
891 site,
892 name,
893 argtypes,
894 typeargtypes,
895 site.tsym.type,
896 true,
897 bestSoFar,
898 allowBoxing,
899 useVarargs,
900 operator,
901 new HashSet<TypeSymbol>());
902 }
903 // where
904 private Symbol findMethod(Env<AttrContext> env,
905 Type site,
906 Name name,
907 List<Type> argtypes,
908 List<Type> typeargtypes,
909 Type intype,
910 boolean abstractok,
911 Symbol bestSoFar,
912 boolean allowBoxing,
913 boolean useVarargs,
914 boolean operator,
915 Set<TypeSymbol> seen) {
916 for (Type ct = intype; ct.tag == CLASS || ct.tag == TYPEVAR; ct = types.supertype(ct)) {
917 while (ct.tag == TYPEVAR)
918 ct = ct.getUpperBound();
919 ClassSymbol c = (ClassSymbol)ct.tsym;
920 if (!seen.add(c)) return bestSoFar;
921 if ((c.flags() & (ABSTRACT | INTERFACE | ENUM)) == 0)
922 abstractok = false;
923 for (Scope.Entry e = c.members().lookup(name);
924 e.scope != null;
925 e = e.next()) {
926 //- System.out.println(" e " + e.sym);
927 if (e.sym.kind == MTH &&
928 (e.sym.flags_field & SYNTHETIC) == 0) {
929 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
930 e.sym, bestSoFar,
931 allowBoxing,
932 useVarargs,
933 operator);
934 }
935 }
936 if (name == names.init)
937 break;
938 //- System.out.println(" - " + bestSoFar);
939 if (abstractok) {
940 Symbol concrete = methodNotFound;
941 if ((bestSoFar.flags() & ABSTRACT) == 0)
942 concrete = bestSoFar;
943 for (List<Type> l = types.interfaces(c.type);
944 l.nonEmpty();
945 l = l.tail) {
946 bestSoFar = findMethod(env, site, name, argtypes,
947 typeargtypes,
948 l.head, abstractok, bestSoFar,
949 allowBoxing, useVarargs, operator, seen);
950 }
951 if (concrete != bestSoFar &&
952 concrete.kind < ERR && bestSoFar.kind < ERR &&
953 types.isSubSignature(concrete.type, bestSoFar.type))
954 bestSoFar = concrete;
955 }
956 }
957 return bestSoFar;
958 }
960 /** Find unqualified method matching given name, type and value arguments.
961 * @param env The current environment.
962 * @param name The method's name.
963 * @param argtypes The method's value arguments.
964 * @param typeargtypes The method's type arguments.
965 * @param allowBoxing Allow boxing conversions of arguments.
966 * @param useVarargs Box trailing arguments into an array for varargs.
967 */
968 Symbol findFun(Env<AttrContext> env, Name name,
969 List<Type> argtypes, List<Type> typeargtypes,
970 boolean allowBoxing, boolean useVarargs) {
971 Symbol bestSoFar = methodNotFound;
972 Symbol sym;
973 Env<AttrContext> env1 = env;
974 boolean staticOnly = false;
975 while (env1.outer != null) {
976 if (isStatic(env1)) staticOnly = true;
977 sym = findMethod(
978 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
979 allowBoxing, useVarargs, false);
980 if (sym.exists()) {
981 if (staticOnly &&
982 sym.kind == MTH &&
983 sym.owner.kind == TYP &&
984 (sym.flags() & STATIC) == 0) return new StaticError(sym);
985 else return sym;
986 } else if (sym.kind < bestSoFar.kind) {
987 bestSoFar = sym;
988 }
989 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
990 env1 = env1.outer;
991 }
993 sym = findMethod(env, syms.predefClass.type, name, argtypes,
994 typeargtypes, allowBoxing, useVarargs, false);
995 if (sym.exists())
996 return sym;
998 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
999 for (; e.scope != null; e = e.next()) {
1000 sym = e.sym;
1001 Type origin = e.getOrigin().owner.type;
1002 if (sym.kind == MTH) {
1003 if (e.sym.owner.type != origin)
1004 sym = sym.clone(e.getOrigin().owner);
1005 if (!isAccessible(env, origin, sym))
1006 sym = new AccessError(env, origin, sym);
1007 bestSoFar = selectBest(env, origin,
1008 argtypes, typeargtypes,
1009 sym, bestSoFar,
1010 allowBoxing, useVarargs, false);
1011 }
1012 }
1013 if (bestSoFar.exists())
1014 return bestSoFar;
1016 e = env.toplevel.starImportScope.lookup(name);
1017 for (; e.scope != null; e = e.next()) {
1018 sym = e.sym;
1019 Type origin = e.getOrigin().owner.type;
1020 if (sym.kind == MTH) {
1021 if (e.sym.owner.type != origin)
1022 sym = sym.clone(e.getOrigin().owner);
1023 if (!isAccessible(env, origin, sym))
1024 sym = new AccessError(env, origin, sym);
1025 bestSoFar = selectBest(env, origin,
1026 argtypes, typeargtypes,
1027 sym, bestSoFar,
1028 allowBoxing, useVarargs, false);
1029 }
1030 }
1031 return bestSoFar;
1032 }
1034 /** Load toplevel or member class with given fully qualified name and
1035 * verify that it is accessible.
1036 * @param env The current environment.
1037 * @param name The fully qualified name of the class to be loaded.
1038 */
1039 Symbol loadClass(Env<AttrContext> env, Name name) {
1040 try {
1041 ClassSymbol c = reader.loadClass(name);
1042 return isAccessible(env, c) ? c : new AccessError(c);
1043 } catch (ClassReader.BadClassFile err) {
1044 throw err;
1045 } catch (CompletionFailure ex) {
1046 return typeNotFound;
1047 }
1048 }
1050 /** Find qualified member type.
1051 * @param env The current environment.
1052 * @param site The original type from where the selection takes
1053 * place.
1054 * @param name The type's name.
1055 * @param c The class to search for the member type. This is
1056 * always a superclass or implemented interface of
1057 * site's class.
1058 */
1059 Symbol findMemberType(Env<AttrContext> env,
1060 Type site,
1061 Name name,
1062 TypeSymbol c) {
1063 Symbol bestSoFar = typeNotFound;
1064 Symbol sym;
1065 Scope.Entry e = c.members().lookup(name);
1066 while (e.scope != null) {
1067 if (e.sym.kind == TYP) {
1068 return isAccessible(env, site, e.sym)
1069 ? e.sym
1070 : new AccessError(env, site, e.sym);
1071 }
1072 e = e.next();
1073 }
1074 Type st = types.supertype(c.type);
1075 if (st != null && st.tag == CLASS) {
1076 sym = findMemberType(env, site, name, st.tsym);
1077 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1078 }
1079 for (List<Type> l = types.interfaces(c.type);
1080 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
1081 l = l.tail) {
1082 sym = findMemberType(env, site, name, l.head.tsym);
1083 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
1084 sym.owner != bestSoFar.owner)
1085 bestSoFar = new AmbiguityError(bestSoFar, sym);
1086 else if (sym.kind < bestSoFar.kind)
1087 bestSoFar = sym;
1088 }
1089 return bestSoFar;
1090 }
1092 /** Find a global type in given scope and load corresponding class.
1093 * @param env The current environment.
1094 * @param scope The scope in which to look for the type.
1095 * @param name The type's name.
1096 */
1097 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
1098 Symbol bestSoFar = typeNotFound;
1099 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
1100 Symbol sym = loadClass(env, e.sym.flatName());
1101 if (bestSoFar.kind == TYP && sym.kind == TYP &&
1102 bestSoFar != sym)
1103 return new AmbiguityError(bestSoFar, sym);
1104 else if (sym.kind < bestSoFar.kind)
1105 bestSoFar = sym;
1106 }
1107 return bestSoFar;
1108 }
1110 /** Find an unqualified type symbol.
1111 * @param env The current environment.
1112 * @param name The type's name.
1113 */
1114 Symbol findType(Env<AttrContext> env, Name name) {
1115 Symbol bestSoFar = typeNotFound;
1116 Symbol sym;
1117 boolean staticOnly = false;
1118 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
1119 if (isStatic(env1)) staticOnly = true;
1120 for (Scope.Entry e = env1.info.scope.lookup(name);
1121 e.scope != null;
1122 e = e.next()) {
1123 if (e.sym.kind == TYP) {
1124 if (staticOnly &&
1125 e.sym.type.tag == TYPEVAR &&
1126 e.sym.owner.kind == TYP) return new StaticError(e.sym);
1127 return e.sym;
1128 }
1129 }
1131 sym = findMemberType(env1, env1.enclClass.sym.type, name,
1132 env1.enclClass.sym);
1133 if (staticOnly && sym.kind == TYP &&
1134 sym.type.tag == CLASS &&
1135 sym.type.getEnclosingType().tag == CLASS &&
1136 env1.enclClass.sym.type.isParameterized() &&
1137 sym.type.getEnclosingType().isParameterized())
1138 return new StaticError(sym);
1139 else if (sym.exists()) return sym;
1140 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1142 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
1143 if ((encl.sym.flags() & STATIC) != 0)
1144 staticOnly = true;
1145 }
1147 if (env.tree.getTag() != JCTree.IMPORT) {
1148 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
1149 if (sym.exists()) return sym;
1150 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1152 sym = findGlobalType(env, env.toplevel.packge.members(), name);
1153 if (sym.exists()) return sym;
1154 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1156 sym = findGlobalType(env, env.toplevel.starImportScope, name);
1157 if (sym.exists()) return sym;
1158 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1159 }
1161 return bestSoFar;
1162 }
1164 /** Find an unqualified identifier which matches a specified kind set.
1165 * @param env The current environment.
1166 * @param name The indentifier's name.
1167 * @param kind Indicates the possible symbol kinds
1168 * (a subset of VAL, TYP, PCK).
1169 */
1170 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
1171 Symbol bestSoFar = typeNotFound;
1172 Symbol sym;
1174 if ((kind & VAR) != 0) {
1175 sym = findVar(env, name);
1176 if (sym.exists()) return sym;
1177 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1178 }
1180 if ((kind & TYP) != 0) {
1181 sym = findType(env, name);
1182 if (sym.exists()) return sym;
1183 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1184 }
1186 if ((kind & PCK) != 0) return reader.enterPackage(name);
1187 else return bestSoFar;
1188 }
1190 /** Find an identifier in a package which matches a specified kind set.
1191 * @param env The current environment.
1192 * @param name The identifier's name.
1193 * @param kind Indicates the possible symbol kinds
1194 * (a nonempty subset of TYP, PCK).
1195 */
1196 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1197 Name name, int kind) {
1198 Name fullname = TypeSymbol.formFullName(name, pck);
1199 Symbol bestSoFar = typeNotFound;
1200 PackageSymbol pack = null;
1201 if ((kind & PCK) != 0) {
1202 pack = reader.enterPackage(fullname);
1203 if (pack.exists()) return pack;
1204 }
1205 if ((kind & TYP) != 0) {
1206 Symbol sym = loadClass(env, fullname);
1207 if (sym.exists()) {
1208 // don't allow programs to use flatnames
1209 if (name == sym.name) return sym;
1210 }
1211 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1212 }
1213 return (pack != null) ? pack : bestSoFar;
1214 }
1216 /** Find an identifier among the members of a given type `site'.
1217 * @param env The current environment.
1218 * @param site The type containing the symbol to be found.
1219 * @param name The identifier's name.
1220 * @param kind Indicates the possible symbol kinds
1221 * (a subset of VAL, TYP).
1222 */
1223 Symbol findIdentInType(Env<AttrContext> env, Type site,
1224 Name name, int kind) {
1225 Symbol bestSoFar = typeNotFound;
1226 Symbol sym;
1227 if ((kind & VAR) != 0) {
1228 sym = findField(env, site, name, site.tsym);
1229 if (sym.exists()) return sym;
1230 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1231 }
1233 if ((kind & TYP) != 0) {
1234 sym = findMemberType(env, site, name, site.tsym);
1235 if (sym.exists()) return sym;
1236 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1237 }
1238 return bestSoFar;
1239 }
1241 /* ***************************************************************************
1242 * Access checking
1243 * The following methods convert ResolveErrors to ErrorSymbols, issuing
1244 * an error message in the process
1245 ****************************************************************************/
1247 /** If `sym' is a bad symbol: report error and return errSymbol
1248 * else pass through unchanged,
1249 * additional arguments duplicate what has been used in trying to find the
1250 * symbol (--> flyweight pattern). This improves performance since we
1251 * expect misses to happen frequently.
1252 *
1253 * @param sym The symbol that was found, or a ResolveError.
1254 * @param pos The position to use for error reporting.
1255 * @param site The original type from where the selection took place.
1256 * @param name The symbol's name.
1257 * @param argtypes The invocation's value arguments,
1258 * if we looked for a method.
1259 * @param typeargtypes The invocation's type arguments,
1260 * if we looked for a method.
1261 */
1262 Symbol access(Symbol sym,
1263 DiagnosticPosition pos,
1264 Symbol location,
1265 Type site,
1266 Name name,
1267 boolean qualified,
1268 List<Type> argtypes,
1269 List<Type> typeargtypes) {
1270 if (sym.kind >= AMBIGUOUS) {
1271 ResolveError errSym = (ResolveError)sym;
1272 if (!site.isErroneous() &&
1273 !Type.isErroneous(argtypes) &&
1274 (typeargtypes==null || !Type.isErroneous(typeargtypes)))
1275 logResolveError(errSym, pos, location, site, name, argtypes, typeargtypes);
1276 sym = errSym.access(name, qualified ? site.tsym : syms.noSymbol);
1277 }
1278 return sym;
1279 }
1281 /** Same as original access(), but without location.
1282 */
1283 Symbol access(Symbol sym,
1284 DiagnosticPosition pos,
1285 Type site,
1286 Name name,
1287 boolean qualified,
1288 List<Type> argtypes,
1289 List<Type> typeargtypes) {
1290 return access(sym, pos, site.tsym, site, name, qualified, argtypes, typeargtypes);
1291 }
1293 /** Same as original access(), but without type arguments and arguments.
1294 */
1295 Symbol access(Symbol sym,
1296 DiagnosticPosition pos,
1297 Symbol location,
1298 Type site,
1299 Name name,
1300 boolean qualified) {
1301 if (sym.kind >= AMBIGUOUS)
1302 return access(sym, pos, location, site, name, qualified, List.<Type>nil(), null);
1303 else
1304 return sym;
1305 }
1307 /** Same as original access(), but without location, type arguments and arguments.
1308 */
1309 Symbol access(Symbol sym,
1310 DiagnosticPosition pos,
1311 Type site,
1312 Name name,
1313 boolean qualified) {
1314 return access(sym, pos, site.tsym, site, name, qualified);
1315 }
1317 /** Check that sym is not an abstract method.
1318 */
1319 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
1320 if ((sym.flags() & ABSTRACT) != 0)
1321 log.error(pos, "abstract.cant.be.accessed.directly",
1322 kindName(sym), sym, sym.location());
1323 }
1325 /* ***************************************************************************
1326 * Debugging
1327 ****************************************************************************/
1329 /** print all scopes starting with scope s and proceeding outwards.
1330 * used for debugging.
1331 */
1332 public void printscopes(Scope s) {
1333 while (s != null) {
1334 if (s.owner != null)
1335 System.err.print(s.owner + ": ");
1336 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
1337 if ((e.sym.flags() & ABSTRACT) != 0)
1338 System.err.print("abstract ");
1339 System.err.print(e.sym + " ");
1340 }
1341 System.err.println();
1342 s = s.next;
1343 }
1344 }
1346 void printscopes(Env<AttrContext> env) {
1347 while (env.outer != null) {
1348 System.err.println("------------------------------");
1349 printscopes(env.info.scope);
1350 env = env.outer;
1351 }
1352 }
1354 public void printscopes(Type t) {
1355 while (t.tag == CLASS) {
1356 printscopes(t.tsym.members());
1357 t = types.supertype(t);
1358 }
1359 }
1361 /* ***************************************************************************
1362 * Name resolution
1363 * Naming conventions are as for symbol lookup
1364 * Unlike the find... methods these methods will report access errors
1365 ****************************************************************************/
1367 /** Resolve an unqualified (non-method) identifier.
1368 * @param pos The position to use for error reporting.
1369 * @param env The environment current at the identifier use.
1370 * @param name The identifier's name.
1371 * @param kind The set of admissible symbol kinds for the identifier.
1372 */
1373 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
1374 Name name, int kind) {
1375 return access(
1376 findIdent(env, name, kind),
1377 pos, env.enclClass.sym.type, name, false);
1378 }
1380 /** Resolve an unqualified method identifier.
1381 * @param pos The position to use for error reporting.
1382 * @param env The environment current at the method invocation.
1383 * @param name The identifier's name.
1384 * @param argtypes The types of the invocation's value arguments.
1385 * @param typeargtypes The types of the invocation's type arguments.
1386 */
1387 Symbol resolveMethod(DiagnosticPosition pos,
1388 Env<AttrContext> env,
1389 Name name,
1390 List<Type> argtypes,
1391 List<Type> typeargtypes) {
1392 Symbol sym = startResolution();
1393 List<MethodResolutionPhase> steps = methodResolutionSteps;
1394 while (steps.nonEmpty() &&
1395 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1396 sym.kind >= ERRONEOUS) {
1397 currentStep = steps.head;
1398 sym = findFun(env, name, argtypes, typeargtypes,
1399 steps.head.isBoxingRequired,
1400 env.info.varArgs = steps.head.isVarargsRequired);
1401 methodResolutionCache.put(steps.head, sym);
1402 steps = steps.tail;
1403 }
1404 if (sym.kind >= AMBIGUOUS) {//if nothing is found return the 'first' error
1405 MethodResolutionPhase errPhase =
1406 firstErroneousResolutionPhase();
1407 sym = access(methodResolutionCache.get(errPhase),
1408 pos, env.enclClass.sym.type, name, false, argtypes, typeargtypes);
1409 env.info.varArgs = errPhase.isVarargsRequired;
1410 }
1411 return sym;
1412 }
1414 private Symbol startResolution() {
1415 wrongMethod.clear();
1416 wrongMethods.clear();
1417 return methodNotFound;
1418 }
1420 /** Resolve a qualified method identifier
1421 * @param pos The position to use for error reporting.
1422 * @param env The environment current at the method invocation.
1423 * @param site The type of the qualifying expression, in which
1424 * identifier is searched.
1425 * @param name The identifier's name.
1426 * @param argtypes The types of the invocation's value arguments.
1427 * @param typeargtypes The types of the invocation's type arguments.
1428 */
1429 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
1430 Type site, Name name, List<Type> argtypes,
1431 List<Type> typeargtypes) {
1432 return resolveQualifiedMethod(pos, env, site.tsym, site, name, argtypes, typeargtypes);
1433 }
1434 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
1435 Symbol location, Type site, Name name, List<Type> argtypes,
1436 List<Type> typeargtypes) {
1437 Symbol sym = startResolution();
1438 List<MethodResolutionPhase> steps = methodResolutionSteps;
1439 while (steps.nonEmpty() &&
1440 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1441 sym.kind >= ERRONEOUS) {
1442 currentStep = steps.head;
1443 sym = findMethod(env, site, name, argtypes, typeargtypes,
1444 steps.head.isBoxingRequired(),
1445 env.info.varArgs = steps.head.isVarargsRequired(), false);
1446 methodResolutionCache.put(steps.head, sym);
1447 steps = steps.tail;
1448 }
1449 if (sym.kind >= AMBIGUOUS) {
1450 if (site.tsym.isPolymorphicSignatureGeneric()) {
1451 //polymorphic receiver - synthesize new method symbol
1452 env.info.varArgs = false;
1453 sym = findPolymorphicSignatureInstance(env,
1454 site, name, null, argtypes);
1455 }
1456 else {
1457 //if nothing is found return the 'first' error
1458 MethodResolutionPhase errPhase =
1459 firstErroneousResolutionPhase();
1460 sym = access(methodResolutionCache.get(errPhase),
1461 pos, location, site, name, true, argtypes, typeargtypes);
1462 env.info.varArgs = errPhase.isVarargsRequired;
1463 }
1464 } else if (allowMethodHandles && sym.isPolymorphicSignatureGeneric()) {
1465 //non-instantiated polymorphic signature - synthesize new method symbol
1466 env.info.varArgs = false;
1467 sym = findPolymorphicSignatureInstance(env,
1468 site, name, (MethodSymbol)sym, argtypes);
1469 }
1470 return sym;
1471 }
1473 /** Find or create an implicit method of exactly the given type (after erasure).
1474 * Searches in a side table, not the main scope of the site.
1475 * This emulates the lookup process required by JSR 292 in JVM.
1476 * @param env Attribution environment
1477 * @param site The original type from where the selection takes place.
1478 * @param name The method's name.
1479 * @param spMethod A template for the implicit method, or null.
1480 * @param argtypes The required argument types.
1481 * @param typeargtypes The required type arguments.
1482 */
1483 Symbol findPolymorphicSignatureInstance(Env<AttrContext> env, Type site,
1484 Name name,
1485 MethodSymbol spMethod, // sig. poly. method or null if none
1486 List<Type> argtypes) {
1487 Type mtype = infer.instantiatePolymorphicSignatureInstance(env,
1488 site, name, spMethod, argtypes);
1489 long flags = ABSTRACT | HYPOTHETICAL | POLYMORPHIC_SIGNATURE |
1490 (spMethod != null ?
1491 spMethod.flags() & Flags.AccessFlags :
1492 Flags.PUBLIC | Flags.STATIC);
1493 Symbol m = null;
1494 for (Scope.Entry e = polymorphicSignatureScope.lookup(name);
1495 e.scope != null;
1496 e = e.next()) {
1497 Symbol sym = e.sym;
1498 if (types.isSameType(mtype, sym.type) &&
1499 (sym.flags() & Flags.STATIC) == (flags & Flags.STATIC) &&
1500 types.isSameType(sym.owner.type, site)) {
1501 m = sym;
1502 break;
1503 }
1504 }
1505 if (m == null) {
1506 // create the desired method
1507 m = new MethodSymbol(flags, name, mtype, site.tsym);
1508 polymorphicSignatureScope.enter(m);
1509 }
1510 return m;
1511 }
1513 /** Resolve a qualified method identifier, throw a fatal error if not
1514 * found.
1515 * @param pos The position to use for error reporting.
1516 * @param env The environment current at the method invocation.
1517 * @param site The type of the qualifying expression, in which
1518 * identifier is searched.
1519 * @param name The identifier's name.
1520 * @param argtypes The types of the invocation's value arguments.
1521 * @param typeargtypes The types of the invocation's type arguments.
1522 */
1523 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
1524 Type site, Name name,
1525 List<Type> argtypes,
1526 List<Type> typeargtypes) {
1527 Symbol sym = resolveQualifiedMethod(
1528 pos, env, site.tsym, site, name, argtypes, typeargtypes);
1529 if (sym.kind == MTH) return (MethodSymbol)sym;
1530 else throw new FatalError(
1531 diags.fragment("fatal.err.cant.locate.meth",
1532 name));
1533 }
1535 /** Resolve constructor.
1536 * @param pos The position to use for error reporting.
1537 * @param env The environment current at the constructor invocation.
1538 * @param site The type of class for which a constructor is searched.
1539 * @param argtypes The types of the constructor invocation's value
1540 * arguments.
1541 * @param typeargtypes The types of the constructor invocation's type
1542 * arguments.
1543 */
1544 Symbol resolveConstructor(DiagnosticPosition pos,
1545 Env<AttrContext> env,
1546 Type site,
1547 List<Type> argtypes,
1548 List<Type> typeargtypes) {
1549 Symbol sym = startResolution();
1550 List<MethodResolutionPhase> steps = methodResolutionSteps;
1551 while (steps.nonEmpty() &&
1552 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1553 sym.kind >= ERRONEOUS) {
1554 currentStep = steps.head;
1555 sym = resolveConstructor(pos, env, site, argtypes, typeargtypes,
1556 steps.head.isBoxingRequired(),
1557 env.info.varArgs = steps.head.isVarargsRequired());
1558 methodResolutionCache.put(steps.head, sym);
1559 steps = steps.tail;
1560 }
1561 if (sym.kind >= AMBIGUOUS) {//if nothing is found return the 'first' error
1562 MethodResolutionPhase errPhase = firstErroneousResolutionPhase();
1563 sym = access(methodResolutionCache.get(errPhase),
1564 pos, site, names.init, true, argtypes, typeargtypes);
1565 env.info.varArgs = errPhase.isVarargsRequired();
1566 }
1567 return sym;
1568 }
1570 /** Resolve constructor using diamond inference.
1571 * @param pos The position to use for error reporting.
1572 * @param env The environment current at the constructor invocation.
1573 * @param site The type of class for which a constructor is searched.
1574 * The scope of this class has been touched in attribution.
1575 * @param argtypes The types of the constructor invocation's value
1576 * arguments.
1577 * @param typeargtypes The types of the constructor invocation's type
1578 * arguments.
1579 */
1580 Symbol resolveDiamond(DiagnosticPosition pos,
1581 Env<AttrContext> env,
1582 Type site,
1583 List<Type> argtypes,
1584 List<Type> typeargtypes) {
1585 Symbol sym = startResolution();
1586 List<MethodResolutionPhase> steps = methodResolutionSteps;
1587 while (steps.nonEmpty() &&
1588 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
1589 sym.kind >= ERRONEOUS) {
1590 currentStep = steps.head;
1591 sym = resolveConstructor(pos, env, site, argtypes, typeargtypes,
1592 steps.head.isBoxingRequired(),
1593 env.info.varArgs = steps.head.isVarargsRequired());
1594 methodResolutionCache.put(steps.head, sym);
1595 steps = steps.tail;
1596 }
1597 if (sym.kind >= AMBIGUOUS) {
1598 final JCDiagnostic details = sym.kind == WRONG_MTH ?
1599 ((InapplicableSymbolError)sym).explanation :
1600 null;
1601 Symbol errSym = new ResolveError(WRONG_MTH, "diamond error") {
1602 @Override
1603 JCDiagnostic getDiagnostic(DiagnosticType dkind, DiagnosticPosition pos,
1604 Symbol location, Type site, Name name, List<Type> argtypes, List<Type> typeargtypes) {
1605 String key = details == null ?
1606 "cant.apply.diamond" :
1607 "cant.apply.diamond.1";
1608 return diags.create(dkind, log.currentSource(), pos, key,
1609 diags.fragment("diamond", site.tsym), details);
1610 }
1611 };
1612 MethodResolutionPhase errPhase = firstErroneousResolutionPhase();
1613 sym = access(errSym, pos, site, names.init, true, argtypes, typeargtypes);
1614 env.info.varArgs = errPhase.isVarargsRequired();
1615 }
1616 return sym;
1617 }
1619 /** Resolve constructor.
1620 * @param pos The position to use for error reporting.
1621 * @param env The environment current at the constructor invocation.
1622 * @param site The type of class for which a constructor is searched.
1623 * @param argtypes The types of the constructor invocation's value
1624 * arguments.
1625 * @param typeargtypes The types of the constructor invocation's type
1626 * arguments.
1627 * @param allowBoxing Allow boxing and varargs conversions.
1628 * @param useVarargs Box trailing arguments into an array for varargs.
1629 */
1630 Symbol resolveConstructor(DiagnosticPosition pos, Env<AttrContext> env,
1631 Type site, List<Type> argtypes,
1632 List<Type> typeargtypes,
1633 boolean allowBoxing,
1634 boolean useVarargs) {
1635 Symbol sym = findMethod(env, site,
1636 names.init, argtypes,
1637 typeargtypes, allowBoxing,
1638 useVarargs, false);
1639 chk.checkDeprecated(pos, env.info.scope.owner, sym);
1640 return sym;
1641 }
1643 /** Resolve a constructor, throw a fatal error if not found.
1644 * @param pos The position to use for error reporting.
1645 * @param env The environment current at the method invocation.
1646 * @param site The type to be constructed.
1647 * @param argtypes The types of the invocation's value arguments.
1648 * @param typeargtypes The types of the invocation's type arguments.
1649 */
1650 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
1651 Type site,
1652 List<Type> argtypes,
1653 List<Type> typeargtypes) {
1654 Symbol sym = resolveConstructor(
1655 pos, env, site, argtypes, typeargtypes);
1656 if (sym.kind == MTH) return (MethodSymbol)sym;
1657 else throw new FatalError(
1658 diags.fragment("fatal.err.cant.locate.ctor", site));
1659 }
1661 /** Resolve operator.
1662 * @param pos The position to use for error reporting.
1663 * @param optag The tag of the operation tree.
1664 * @param env The environment current at the operation.
1665 * @param argtypes The types of the operands.
1666 */
1667 Symbol resolveOperator(DiagnosticPosition pos, int optag,
1668 Env<AttrContext> env, List<Type> argtypes) {
1669 Name name = treeinfo.operatorName(optag);
1670 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
1671 null, false, false, true);
1672 if (boxingEnabled && sym.kind >= WRONG_MTHS)
1673 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1674 null, true, false, true);
1675 return access(sym, pos, env.enclClass.sym.type, name,
1676 false, argtypes, null);
1677 }
1679 /** Resolve operator.
1680 * @param pos The position to use for error reporting.
1681 * @param optag The tag of the operation tree.
1682 * @param env The environment current at the operation.
1683 * @param arg The type of the operand.
1684 */
1685 Symbol resolveUnaryOperator(DiagnosticPosition pos, int optag, Env<AttrContext> env, Type arg) {
1686 return resolveOperator(pos, optag, env, List.of(arg));
1687 }
1689 /** Resolve binary operator.
1690 * @param pos The position to use for error reporting.
1691 * @param optag The tag of the operation tree.
1692 * @param env The environment current at the operation.
1693 * @param left The types of the left operand.
1694 * @param right The types of the right operand.
1695 */
1696 Symbol resolveBinaryOperator(DiagnosticPosition pos,
1697 int optag,
1698 Env<AttrContext> env,
1699 Type left,
1700 Type right) {
1701 return resolveOperator(pos, optag, env, List.of(left, right));
1702 }
1704 /**
1705 * Resolve `c.name' where name == this or name == super.
1706 * @param pos The position to use for error reporting.
1707 * @param env The environment current at the expression.
1708 * @param c The qualifier.
1709 * @param name The identifier's name.
1710 */
1711 Symbol resolveSelf(DiagnosticPosition pos,
1712 Env<AttrContext> env,
1713 TypeSymbol c,
1714 Name name) {
1715 Env<AttrContext> env1 = env;
1716 boolean staticOnly = false;
1717 while (env1.outer != null) {
1718 if (isStatic(env1)) staticOnly = true;
1719 if (env1.enclClass.sym == c) {
1720 Symbol sym = env1.info.scope.lookup(name).sym;
1721 if (sym != null) {
1722 if (staticOnly) sym = new StaticError(sym);
1723 return access(sym, pos, env.enclClass.sym.type,
1724 name, true);
1725 }
1726 }
1727 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1728 env1 = env1.outer;
1729 }
1730 log.error(pos, "not.encl.class", c);
1731 return syms.errSymbol;
1732 }
1734 /**
1735 * Resolve `c.this' for an enclosing class c that contains the
1736 * named member.
1737 * @param pos The position to use for error reporting.
1738 * @param env The environment current at the expression.
1739 * @param member The member that must be contained in the result.
1740 */
1741 Symbol resolveSelfContaining(DiagnosticPosition pos,
1742 Env<AttrContext> env,
1743 Symbol member,
1744 boolean isSuperCall) {
1745 Name name = names._this;
1746 Env<AttrContext> env1 = isSuperCall ? env.outer : env;
1747 boolean staticOnly = false;
1748 if (env1 != null) {
1749 while (env1 != null && env1.outer != null) {
1750 if (isStatic(env1)) staticOnly = true;
1751 if (env1.enclClass.sym.isSubClass(member.owner, types)) {
1752 Symbol sym = env1.info.scope.lookup(name).sym;
1753 if (sym != null) {
1754 if (staticOnly) sym = new StaticError(sym);
1755 return access(sym, pos, env.enclClass.sym.type,
1756 name, true);
1757 }
1758 }
1759 if ((env1.enclClass.sym.flags() & STATIC) != 0)
1760 staticOnly = true;
1761 env1 = env1.outer;
1762 }
1763 }
1764 log.error(pos, "encl.class.required", member);
1765 return syms.errSymbol;
1766 }
1768 /**
1769 * Resolve an appropriate implicit this instance for t's container.
1770 * JLS 8.8.5.1 and 15.9.2
1771 */
1772 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
1773 return resolveImplicitThis(pos, env, t, false);
1774 }
1776 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t, boolean isSuperCall) {
1777 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
1778 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
1779 : resolveSelfContaining(pos, env, t.tsym, isSuperCall)).type;
1780 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
1781 log.error(pos, "cant.ref.before.ctor.called", "this");
1782 return thisType;
1783 }
1785 /* ***************************************************************************
1786 * ResolveError classes, indicating error situations when accessing symbols
1787 ****************************************************************************/
1789 public void logAccessError(Env<AttrContext> env, JCTree tree, Type type) {
1790 AccessError error = new AccessError(env, type.getEnclosingType(), type.tsym);
1791 logResolveError(error, tree.pos(), type.getEnclosingType().tsym, type.getEnclosingType(), null, null, null);
1792 }
1793 //where
1794 private void logResolveError(ResolveError error,
1795 DiagnosticPosition pos,
1796 Symbol location,
1797 Type site,
1798 Name name,
1799 List<Type> argtypes,
1800 List<Type> typeargtypes) {
1801 JCDiagnostic d = error.getDiagnostic(JCDiagnostic.DiagnosticType.ERROR,
1802 pos, location, site, name, argtypes, typeargtypes);
1803 if (d != null) {
1804 d.setFlag(DiagnosticFlag.RESOLVE_ERROR);
1805 log.report(d);
1806 }
1807 }
1809 private final LocalizedString noArgs = new LocalizedString("compiler.misc.no.args");
1811 public Object methodArguments(List<Type> argtypes) {
1812 return argtypes.isEmpty() ? noArgs : argtypes;
1813 }
1815 /**
1816 * Root class for resolution errors. Subclass of ResolveError
1817 * represent a different kinds of resolution error - as such they must
1818 * specify how they map into concrete compiler diagnostics.
1819 */
1820 private abstract class ResolveError extends Symbol {
1822 /** The name of the kind of error, for debugging only. */
1823 final String debugName;
1825 ResolveError(int kind, String debugName) {
1826 super(kind, 0, null, null, null);
1827 this.debugName = debugName;
1828 }
1830 @Override
1831 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
1832 throw new AssertionError();
1833 }
1835 @Override
1836 public String toString() {
1837 return debugName;
1838 }
1840 @Override
1841 public boolean exists() {
1842 return false;
1843 }
1845 /**
1846 * Create an external representation for this erroneous symbol to be
1847 * used during attribution - by default this returns the symbol of a
1848 * brand new error type which stores the original type found
1849 * during resolution.
1850 *
1851 * @param name the name used during resolution
1852 * @param location the location from which the symbol is accessed
1853 */
1854 protected Symbol access(Name name, TypeSymbol location) {
1855 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
1856 }
1858 /**
1859 * Create a diagnostic representing this resolution error.
1860 *
1861 * @param dkind The kind of the diagnostic to be created (e.g error).
1862 * @param pos The position to be used for error reporting.
1863 * @param site The original type from where the selection took place.
1864 * @param name The name of the symbol to be resolved.
1865 * @param argtypes The invocation's value arguments,
1866 * if we looked for a method.
1867 * @param typeargtypes The invocation's type arguments,
1868 * if we looked for a method.
1869 */
1870 abstract JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
1871 DiagnosticPosition pos,
1872 Symbol location,
1873 Type site,
1874 Name name,
1875 List<Type> argtypes,
1876 List<Type> typeargtypes);
1878 /**
1879 * A name designates an operator if it consists
1880 * of a non-empty sequence of operator symbols +-~!/*%&|^<>=
1881 */
1882 boolean isOperator(Name name) {
1883 int i = 0;
1884 while (i < name.getByteLength() &&
1885 "+-~!*/%&|^<>=".indexOf(name.getByteAt(i)) >= 0) i++;
1886 return i > 0 && i == name.getByteLength();
1887 }
1888 }
1890 /**
1891 * This class is the root class of all resolution errors caused by
1892 * an invalid symbol being found during resolution.
1893 */
1894 abstract class InvalidSymbolError extends ResolveError {
1896 /** The invalid symbol found during resolution */
1897 Symbol sym;
1899 InvalidSymbolError(int kind, Symbol sym, String debugName) {
1900 super(kind, debugName);
1901 this.sym = sym;
1902 }
1904 @Override
1905 public boolean exists() {
1906 return true;
1907 }
1909 @Override
1910 public String toString() {
1911 return super.toString() + " wrongSym=" + sym;
1912 }
1914 @Override
1915 public Symbol access(Name name, TypeSymbol location) {
1916 if (sym.kind >= AMBIGUOUS)
1917 return ((ResolveError)sym).access(name, location);
1918 else if ((sym.kind & ERRONEOUS) == 0 && (sym.kind & TYP) != 0)
1919 return types.createErrorType(name, location, sym.type).tsym;
1920 else
1921 return sym;
1922 }
1923 }
1925 /**
1926 * InvalidSymbolError error class indicating that a symbol matching a
1927 * given name does not exists in a given site.
1928 */
1929 class SymbolNotFoundError extends ResolveError {
1931 SymbolNotFoundError(int kind) {
1932 super(kind, "symbol not found error");
1933 }
1935 @Override
1936 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
1937 DiagnosticPosition pos,
1938 Symbol location,
1939 Type site,
1940 Name name,
1941 List<Type> argtypes,
1942 List<Type> typeargtypes) {
1943 argtypes = argtypes == null ? List.<Type>nil() : argtypes;
1944 typeargtypes = typeargtypes == null ? List.<Type>nil() : typeargtypes;
1945 if (name == names.error)
1946 return null;
1948 if (isOperator(name)) {
1949 boolean isUnaryOp = argtypes.size() == 1;
1950 String key = argtypes.size() == 1 ?
1951 "operator.cant.be.applied" :
1952 "operator.cant.be.applied.1";
1953 Type first = argtypes.head;
1954 Type second = !isUnaryOp ? argtypes.tail.head : null;
1955 return diags.create(dkind, log.currentSource(), pos,
1956 key, name, first, second);
1957 }
1958 boolean hasLocation = false;
1959 if (location == null) {
1960 location = site.tsym;
1961 }
1962 if (!location.name.isEmpty()) {
1963 if (location.kind == PCK && !site.tsym.exists()) {
1964 return diags.create(dkind, log.currentSource(), pos,
1965 "doesnt.exist", location);
1966 }
1967 hasLocation = !location.name.equals(names._this) &&
1968 !location.name.equals(names._super);
1969 }
1970 boolean isConstructor = kind == ABSENT_MTH &&
1971 name == names.table.names.init;
1972 KindName kindname = isConstructor ? KindName.CONSTRUCTOR : absentKind(kind);
1973 Name idname = isConstructor ? site.tsym.name : name;
1974 String errKey = getErrorKey(kindname, typeargtypes.nonEmpty(), hasLocation);
1975 if (hasLocation) {
1976 return diags.create(dkind, log.currentSource(), pos,
1977 errKey, kindname, idname, //symbol kindname, name
1978 typeargtypes, argtypes, //type parameters and arguments (if any)
1979 getLocationDiag(location, site)); //location kindname, type
1980 }
1981 else {
1982 return diags.create(dkind, log.currentSource(), pos,
1983 errKey, kindname, idname, //symbol kindname, name
1984 typeargtypes, argtypes); //type parameters and arguments (if any)
1985 }
1986 }
1987 //where
1988 private String getErrorKey(KindName kindname, boolean hasTypeArgs, boolean hasLocation) {
1989 String key = "cant.resolve";
1990 String suffix = hasLocation ? ".location" : "";
1991 switch (kindname) {
1992 case METHOD:
1993 case CONSTRUCTOR: {
1994 suffix += ".args";
1995 suffix += hasTypeArgs ? ".params" : "";
1996 }
1997 }
1998 return key + suffix;
1999 }
2000 private JCDiagnostic getLocationDiag(Symbol location, Type site) {
2001 if (location.kind == VAR) {
2002 return diags.fragment("location.1",
2003 kindName(location),
2004 location,
2005 location.type);
2006 } else {
2007 return diags.fragment("location",
2008 typeKindName(site),
2009 site,
2010 null);
2011 }
2012 }
2013 }
2015 /**
2016 * InvalidSymbolError error class indicating that a given symbol
2017 * (either a method, a constructor or an operand) is not applicable
2018 * given an actual arguments/type argument list.
2019 */
2020 class InapplicableSymbolError extends InvalidSymbolError {
2022 /** An auxiliary explanation set in case of instantiation errors. */
2023 JCDiagnostic explanation;
2025 InapplicableSymbolError(Symbol sym) {
2026 super(WRONG_MTH, sym, "inapplicable symbol error");
2027 }
2029 /** Update sym and explanation and return this.
2030 */
2031 InapplicableSymbolError setWrongSym(Symbol sym, JCDiagnostic explanation) {
2032 this.sym = sym;
2033 if (this.sym == sym && explanation != null)
2034 this.explanation = explanation; //update the details
2035 return this;
2036 }
2038 /** Update sym and return this.
2039 */
2040 InapplicableSymbolError setWrongSym(Symbol sym) {
2041 this.sym = sym;
2042 return this;
2043 }
2045 @Override
2046 public String toString() {
2047 return super.toString() + " explanation=" + explanation;
2048 }
2050 @Override
2051 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2052 DiagnosticPosition pos,
2053 Symbol location,
2054 Type site,
2055 Name name,
2056 List<Type> argtypes,
2057 List<Type> typeargtypes) {
2058 if (name == names.error)
2059 return null;
2061 if (isOperator(name)) {
2062 boolean isUnaryOp = argtypes.size() == 1;
2063 String key = argtypes.size() == 1 ?
2064 "operator.cant.be.applied" :
2065 "operator.cant.be.applied.1";
2066 Type first = argtypes.head;
2067 Type second = !isUnaryOp ? argtypes.tail.head : null;
2068 return diags.create(dkind, log.currentSource(), pos,
2069 key, name, first, second);
2070 }
2071 else {
2072 Symbol ws = sym.asMemberOf(site, types);
2073 return diags.create(dkind, log.currentSource(), pos,
2074 "cant.apply.symbol" + (explanation != null ? ".1" : ""),
2075 kindName(ws),
2076 ws.name == names.init ? ws.owner.name : ws.name,
2077 methodArguments(ws.type.getParameterTypes()),
2078 methodArguments(argtypes),
2079 kindName(ws.owner),
2080 ws.owner.type,
2081 explanation);
2082 }
2083 }
2085 void clear() {
2086 explanation = null;
2087 }
2089 @Override
2090 public Symbol access(Name name, TypeSymbol location) {
2091 return types.createErrorType(name, location, syms.errSymbol.type).tsym;
2092 }
2093 }
2095 /**
2096 * ResolveError error class indicating that a set of symbols
2097 * (either methods, constructors or operands) is not applicable
2098 * given an actual arguments/type argument list.
2099 */
2100 class InapplicableSymbolsError extends ResolveError {
2102 private List<Candidate> candidates = List.nil();
2104 InapplicableSymbolsError(Symbol sym) {
2105 super(WRONG_MTHS, "inapplicable symbols");
2106 }
2108 @Override
2109 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2110 DiagnosticPosition pos,
2111 Symbol location,
2112 Type site,
2113 Name name,
2114 List<Type> argtypes,
2115 List<Type> typeargtypes) {
2116 if (candidates.nonEmpty()) {
2117 JCDiagnostic err = diags.create(dkind,
2118 log.currentSource(),
2119 pos,
2120 "cant.apply.symbols",
2121 name == names.init ? KindName.CONSTRUCTOR : absentKind(kind),
2122 getName(),
2123 argtypes);
2124 return new JCDiagnostic.MultilineDiagnostic(err, candidateDetails(site));
2125 } else {
2126 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind, pos,
2127 location, site, name, argtypes, typeargtypes);
2128 }
2129 }
2131 //where
2132 List<JCDiagnostic> candidateDetails(Type site) {
2133 List<JCDiagnostic> details = List.nil();
2134 for (Candidate c : candidates)
2135 details = details.prepend(c.getDiagnostic(site));
2136 return details.reverse();
2137 }
2139 Symbol addCandidate(MethodResolutionPhase currentStep, Symbol sym, JCDiagnostic details) {
2140 Candidate c = new Candidate(currentStep, sym, details);
2141 if (c.isValid() && !candidates.contains(c))
2142 candidates = candidates.append(c);
2143 return this;
2144 }
2146 void clear() {
2147 candidates = List.nil();
2148 }
2150 private Name getName() {
2151 Symbol sym = candidates.head.sym;
2152 return sym.name == names.init ?
2153 sym.owner.name :
2154 sym.name;
2155 }
2157 private class Candidate {
2159 final MethodResolutionPhase step;
2160 final Symbol sym;
2161 final JCDiagnostic details;
2163 private Candidate(MethodResolutionPhase step, Symbol sym, JCDiagnostic details) {
2164 this.step = step;
2165 this.sym = sym;
2166 this.details = details;
2167 }
2169 JCDiagnostic getDiagnostic(Type site) {
2170 return diags.fragment("inapplicable.method",
2171 Kinds.kindName(sym),
2172 sym.location(site, types),
2173 sym.asMemberOf(site, types),
2174 details);
2175 }
2177 @Override
2178 public boolean equals(Object o) {
2179 if (o instanceof Candidate) {
2180 Symbol s1 = this.sym;
2181 Symbol s2 = ((Candidate)o).sym;
2182 if ((s1 != s2 &&
2183 (s1.overrides(s2, s1.owner.type.tsym, types, false) ||
2184 (s2.overrides(s1, s2.owner.type.tsym, types, false)))) ||
2185 ((s1.isConstructor() || s2.isConstructor()) && s1.owner != s2.owner))
2186 return true;
2187 }
2188 return false;
2189 }
2191 boolean isValid() {
2192 return (((sym.flags() & VARARGS) != 0 && step == VARARITY) ||
2193 (sym.flags() & VARARGS) == 0 && step == (boxingEnabled ? BOX : BASIC));
2194 }
2195 }
2196 }
2198 /**
2199 * An InvalidSymbolError error class indicating that a symbol is not
2200 * accessible from a given site
2201 */
2202 class AccessError extends InvalidSymbolError {
2204 private Env<AttrContext> env;
2205 private Type site;
2207 AccessError(Symbol sym) {
2208 this(null, null, sym);
2209 }
2211 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
2212 super(HIDDEN, sym, "access error");
2213 this.env = env;
2214 this.site = site;
2215 if (debugResolve)
2216 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
2217 }
2219 @Override
2220 public boolean exists() {
2221 return false;
2222 }
2224 @Override
2225 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2226 DiagnosticPosition pos,
2227 Symbol location,
2228 Type site,
2229 Name name,
2230 List<Type> argtypes,
2231 List<Type> typeargtypes) {
2232 if (sym.owner.type.tag == ERROR)
2233 return null;
2235 if (sym.name == names.init && sym.owner != site.tsym) {
2236 return new SymbolNotFoundError(ABSENT_MTH).getDiagnostic(dkind,
2237 pos, location, site, name, argtypes, typeargtypes);
2238 }
2239 else if ((sym.flags() & PUBLIC) != 0
2240 || (env != null && this.site != null
2241 && !isAccessible(env, this.site))) {
2242 return diags.create(dkind, log.currentSource(),
2243 pos, "not.def.access.class.intf.cant.access",
2244 sym, sym.location());
2245 }
2246 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0) {
2247 return diags.create(dkind, log.currentSource(),
2248 pos, "report.access", sym,
2249 asFlagSet(sym.flags() & (PRIVATE | PROTECTED)),
2250 sym.location());
2251 }
2252 else {
2253 return diags.create(dkind, log.currentSource(),
2254 pos, "not.def.public.cant.access", sym, sym.location());
2255 }
2256 }
2257 }
2259 /**
2260 * InvalidSymbolError error class indicating that an instance member
2261 * has erroneously been accessed from a static context.
2262 */
2263 class StaticError extends InvalidSymbolError {
2265 StaticError(Symbol sym) {
2266 super(STATICERR, sym, "static error");
2267 }
2269 @Override
2270 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2271 DiagnosticPosition pos,
2272 Symbol location,
2273 Type site,
2274 Name name,
2275 List<Type> argtypes,
2276 List<Type> typeargtypes) {
2277 Symbol errSym = ((sym.kind == TYP && sym.type.tag == CLASS)
2278 ? types.erasure(sym.type).tsym
2279 : sym);
2280 return diags.create(dkind, log.currentSource(), pos,
2281 "non-static.cant.be.ref", kindName(sym), errSym);
2282 }
2283 }
2285 /**
2286 * InvalidSymbolError error class indicating that a pair of symbols
2287 * (either methods, constructors or operands) are ambiguous
2288 * given an actual arguments/type argument list.
2289 */
2290 class AmbiguityError extends InvalidSymbolError {
2292 /** The other maximally specific symbol */
2293 Symbol sym2;
2295 AmbiguityError(Symbol sym1, Symbol sym2) {
2296 super(AMBIGUOUS, sym1, "ambiguity error");
2297 this.sym2 = sym2;
2298 }
2300 @Override
2301 JCDiagnostic getDiagnostic(JCDiagnostic.DiagnosticType dkind,
2302 DiagnosticPosition pos,
2303 Symbol location,
2304 Type site,
2305 Name name,
2306 List<Type> argtypes,
2307 List<Type> typeargtypes) {
2308 AmbiguityError pair = this;
2309 while (true) {
2310 if (pair.sym.kind == AMBIGUOUS)
2311 pair = (AmbiguityError)pair.sym;
2312 else if (pair.sym2.kind == AMBIGUOUS)
2313 pair = (AmbiguityError)pair.sym2;
2314 else break;
2315 }
2316 Name sname = pair.sym.name;
2317 if (sname == names.init) sname = pair.sym.owner.name;
2318 return diags.create(dkind, log.currentSource(),
2319 pos, "ref.ambiguous", sname,
2320 kindName(pair.sym),
2321 pair.sym,
2322 pair.sym.location(site, types),
2323 kindName(pair.sym2),
2324 pair.sym2,
2325 pair.sym2.location(site, types));
2326 }
2327 }
2329 enum MethodResolutionPhase {
2330 BASIC(false, false),
2331 BOX(true, false),
2332 VARARITY(true, true);
2334 boolean isBoxingRequired;
2335 boolean isVarargsRequired;
2337 MethodResolutionPhase(boolean isBoxingRequired, boolean isVarargsRequired) {
2338 this.isBoxingRequired = isBoxingRequired;
2339 this.isVarargsRequired = isVarargsRequired;
2340 }
2342 public boolean isBoxingRequired() {
2343 return isBoxingRequired;
2344 }
2346 public boolean isVarargsRequired() {
2347 return isVarargsRequired;
2348 }
2350 public boolean isApplicable(boolean boxingEnabled, boolean varargsEnabled) {
2351 return (varargsEnabled || !isVarargsRequired) &&
2352 (boxingEnabled || !isBoxingRequired);
2353 }
2354 }
2356 private Map<MethodResolutionPhase, Symbol> methodResolutionCache =
2357 new HashMap<MethodResolutionPhase, Symbol>(MethodResolutionPhase.values().length);
2359 final List<MethodResolutionPhase> methodResolutionSteps = List.of(BASIC, BOX, VARARITY);
2361 private MethodResolutionPhase currentStep = null;
2363 private MethodResolutionPhase firstErroneousResolutionPhase() {
2364 MethodResolutionPhase bestSoFar = BASIC;
2365 Symbol sym = methodNotFound;
2366 List<MethodResolutionPhase> steps = methodResolutionSteps;
2367 while (steps.nonEmpty() &&
2368 steps.head.isApplicable(boxingEnabled, varargsEnabled) &&
2369 sym.kind >= WRONG_MTHS) {
2370 sym = methodResolutionCache.get(steps.head);
2371 bestSoFar = steps.head;
2372 steps = steps.tail;
2373 }
2374 return bestSoFar;
2375 }
2376 }
