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src/share/classes/com/sun/tools/javac/comp/Resolve.java@4a3b9801f7a0
src/share/classes/com/sun/tools/javac/comp/Resolve.java
Fri, 20 Jun 2008 11:25:03 +0100
- author
- mcimadamore
- date
- Fri, 20 Jun 2008 11:25:03 +0100
- changeset 59
- 4a3b9801f7a0
- parent 40
- 8852d96b593b
- child 54
- eaf608c64fec
- permissions
- -rw-r--r--
6294779: Problem with interface inheritance and covariant return types
Summary: Problematic overriding check when two methods defined in two distinct superinterfaces are overriden by an interface
Reviewed-by: jjg
1 /*
2 * Copyright 1999-2006 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any 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.*;
34 import com.sun.tools.javac.code.Type.*;
35 import com.sun.tools.javac.code.Symbol.*;
36 import com.sun.tools.javac.tree.JCTree.*;
38 import static com.sun.tools.javac.code.Flags.*;
39 import static com.sun.tools.javac.code.Kinds.*;
40 import static com.sun.tools.javac.code.TypeTags.*;
41 import javax.lang.model.element.ElementVisitor;
43 /** Helper class for name resolution, used mostly by the attribution phase.
44 *
45 * <p><b>This is NOT part of any API supported by Sun Microsystems. If
46 * you write code that depends on this, you do so at your own risk.
47 * This code and its internal interfaces are subject to change or
48 * deletion without notice.</b>
49 */
50 public class Resolve {
51 protected static final Context.Key<Resolve> resolveKey =
52 new Context.Key<Resolve>();
54 Name.Table names;
55 Log log;
56 Symtab syms;
57 Check chk;
58 Infer infer;
59 ClassReader reader;
60 TreeInfo treeinfo;
61 Types types;
62 public final boolean boxingEnabled; // = source.allowBoxing();
63 public final boolean varargsEnabled; // = source.allowVarargs();
64 private final boolean debugResolve;
66 public static Resolve instance(Context context) {
67 Resolve instance = context.get(resolveKey);
68 if (instance == null)
69 instance = new Resolve(context);
70 return instance;
71 }
73 protected Resolve(Context context) {
74 context.put(resolveKey, this);
75 syms = Symtab.instance(context);
77 varNotFound = new
78 ResolveError(ABSENT_VAR, syms.errSymbol, "variable not found");
79 wrongMethod = new
80 ResolveError(WRONG_MTH, syms.errSymbol, "method not found");
81 wrongMethods = new
82 ResolveError(WRONG_MTHS, syms.errSymbol, "wrong methods");
83 methodNotFound = new
84 ResolveError(ABSENT_MTH, syms.errSymbol, "method not found");
85 typeNotFound = new
86 ResolveError(ABSENT_TYP, syms.errSymbol, "type not found");
88 names = Name.Table.instance(context);
89 log = Log.instance(context);
90 chk = Check.instance(context);
91 infer = Infer.instance(context);
92 reader = ClassReader.instance(context);
93 treeinfo = TreeInfo.instance(context);
94 types = Types.instance(context);
95 Source source = Source.instance(context);
96 boxingEnabled = source.allowBoxing();
97 varargsEnabled = source.allowVarargs();
98 Options options = Options.instance(context);
99 debugResolve = options.get("debugresolve") != null;
100 }
102 /** error symbols, which are returned when resolution fails
103 */
104 final ResolveError varNotFound;
105 final ResolveError wrongMethod;
106 final ResolveError wrongMethods;
107 final ResolveError methodNotFound;
108 final ResolveError typeNotFound;
110 /* ************************************************************************
111 * Identifier resolution
112 *************************************************************************/
114 /** An environment is "static" if its static level is greater than
115 * the one of its outer environment
116 */
117 static boolean isStatic(Env<AttrContext> env) {
118 return env.info.staticLevel > env.outer.info.staticLevel;
119 }
121 /** An environment is an "initializer" if it is a constructor or
122 * an instance initializer.
123 */
124 static boolean isInitializer(Env<AttrContext> env) {
125 Symbol owner = env.info.scope.owner;
126 return owner.isConstructor() ||
127 owner.owner.kind == TYP &&
128 (owner.kind == VAR ||
129 owner.kind == MTH && (owner.flags() & BLOCK) != 0) &&
130 (owner.flags() & STATIC) == 0;
131 }
133 /** Is class accessible in given evironment?
134 * @param env The current environment.
135 * @param c The class whose accessibility is checked.
136 */
137 public boolean isAccessible(Env<AttrContext> env, TypeSymbol c) {
138 switch ((short)(c.flags() & AccessFlags)) {
139 case PRIVATE:
140 return
141 env.enclClass.sym.outermostClass() ==
142 c.owner.outermostClass();
143 case 0:
144 return
145 env.toplevel.packge == c.owner // fast special case
146 ||
147 env.toplevel.packge == c.packge()
148 ||
149 // Hack: this case is added since synthesized default constructors
150 // of anonymous classes should be allowed to access
151 // classes which would be inaccessible otherwise.
152 env.enclMethod != null &&
153 (env.enclMethod.mods.flags & ANONCONSTR) != 0;
154 default: // error recovery
155 case PUBLIC:
156 return true;
157 case PROTECTED:
158 return
159 env.toplevel.packge == c.owner // fast special case
160 ||
161 env.toplevel.packge == c.packge()
162 ||
163 isInnerSubClass(env.enclClass.sym, c.owner);
164 }
165 }
166 //where
167 /** Is given class a subclass of given base class, or an inner class
168 * of a subclass?
169 * Return null if no such class exists.
170 * @param c The class which is the subclass or is contained in it.
171 * @param base The base class
172 */
173 private boolean isInnerSubClass(ClassSymbol c, Symbol base) {
174 while (c != null && !c.isSubClass(base, types)) {
175 c = c.owner.enclClass();
176 }
177 return c != null;
178 }
180 boolean isAccessible(Env<AttrContext> env, Type t) {
181 return (t.tag == ARRAY)
182 ? isAccessible(env, types.elemtype(t))
183 : isAccessible(env, t.tsym);
184 }
186 /** Is symbol accessible as a member of given type in given evironment?
187 * @param env The current environment.
188 * @param site The type of which the tested symbol is regarded
189 * as a member.
190 * @param sym The symbol.
191 */
192 public boolean isAccessible(Env<AttrContext> env, Type site, Symbol sym) {
193 if (sym.name == names.init && sym.owner != site.tsym) return false;
194 ClassSymbol sub;
195 switch ((short)(sym.flags() & AccessFlags)) {
196 case PRIVATE:
197 return
198 (env.enclClass.sym == sym.owner // fast special case
199 ||
200 env.enclClass.sym.outermostClass() ==
201 sym.owner.outermostClass())
202 &&
203 sym.isInheritedIn(site.tsym, types);
204 case 0:
205 return
206 (env.toplevel.packge == sym.owner.owner // fast special case
207 ||
208 env.toplevel.packge == sym.packge())
209 &&
210 isAccessible(env, site)
211 &&
212 sym.isInheritedIn(site.tsym, types);
213 case PROTECTED:
214 return
215 (env.toplevel.packge == sym.owner.owner // fast special case
216 ||
217 env.toplevel.packge == sym.packge()
218 ||
219 isProtectedAccessible(sym, env.enclClass.sym, site)
220 ||
221 // OK to select instance method or field from 'super' or type name
222 // (but type names should be disallowed elsewhere!)
223 env.info.selectSuper && (sym.flags() & STATIC) == 0 && sym.kind != TYP)
224 &&
225 isAccessible(env, site)
226 &&
227 // `sym' is accessible only if not overridden by
228 // another symbol which is a member of `site'
229 // (because, if it is overridden, `sym' is not strictly
230 // speaking a member of `site'.)
231 (sym.kind != MTH || sym.isConstructor() || sym.isStatic() ||
232 ((MethodSymbol)sym).implementation(site.tsym, types, true) == sym);
233 default: // this case includes erroneous combinations as well
234 return isAccessible(env, site);
235 }
236 }
237 //where
238 /** Is given protected symbol accessible if it is selected from given site
239 * and the selection takes place in given class?
240 * @param sym The symbol with protected access
241 * @param c The class where the access takes place
242 * @site The type of the qualifier
243 */
244 private
245 boolean isProtectedAccessible(Symbol sym, ClassSymbol c, Type site) {
246 while (c != null &&
247 !(c.isSubClass(sym.owner, types) &&
248 (c.flags() & INTERFACE) == 0 &&
249 // In JLS 2e 6.6.2.1, the subclass restriction applies
250 // only to instance fields and methods -- types are excluded
251 // regardless of whether they are declared 'static' or not.
252 ((sym.flags() & STATIC) != 0 || sym.kind == TYP || site.tsym.isSubClass(c, types))))
253 c = c.owner.enclClass();
254 return c != null;
255 }
257 /** Try to instantiate the type of a method so that it fits
258 * given type arguments and argument types. If succesful, return
259 * the method's instantiated type, else return null.
260 * The instantiation will take into account an additional leading
261 * formal parameter if the method is an instance method seen as a member
262 * of un underdetermined site In this case, we treat site as an additional
263 * parameter and the parameters of the class containing the method as
264 * additional type variables that get instantiated.
265 *
266 * @param env The current environment
267 * @param site The type of which the method is a member.
268 * @param m The method symbol.
269 * @param argtypes The invocation's given value arguments.
270 * @param typeargtypes The invocation's given type arguments.
271 * @param allowBoxing Allow boxing conversions of arguments.
272 * @param useVarargs Box trailing arguments into an array for varargs.
273 */
274 Type rawInstantiate(Env<AttrContext> env,
275 Type site,
276 Symbol m,
277 List<Type> argtypes,
278 List<Type> typeargtypes,
279 boolean allowBoxing,
280 boolean useVarargs,
281 Warner warn)
282 throws Infer.NoInstanceException {
283 if (useVarargs && (m.flags() & VARARGS) == 0) return null;
284 Type mt = types.memberType(site, m);
286 // tvars is the list of formal type variables for which type arguments
287 // need to inferred.
288 List<Type> tvars = env.info.tvars;
289 if (typeargtypes == null) typeargtypes = List.nil();
290 if (mt.tag != FORALL && typeargtypes.nonEmpty()) {
291 // This is not a polymorphic method, but typeargs are supplied
292 // which is fine, see JLS3 15.12.2.1
293 } else if (mt.tag == FORALL && typeargtypes.nonEmpty()) {
294 ForAll pmt = (ForAll) mt;
295 if (typeargtypes.length() != pmt.tvars.length())
296 return null;
297 // Check type arguments are within bounds
298 List<Type> formals = pmt.tvars;
299 List<Type> actuals = typeargtypes;
300 while (formals.nonEmpty() && actuals.nonEmpty()) {
301 List<Type> bounds = types.subst(types.getBounds((TypeVar)formals.head),
302 pmt.tvars, typeargtypes);
303 for (; bounds.nonEmpty(); bounds = bounds.tail)
304 if (!types.isSubtypeUnchecked(actuals.head, bounds.head, warn))
305 return null;
306 formals = formals.tail;
307 actuals = actuals.tail;
308 }
309 mt = types.subst(pmt.qtype, pmt.tvars, typeargtypes);
310 } else if (mt.tag == FORALL) {
311 ForAll pmt = (ForAll) mt;
312 List<Type> tvars1 = types.newInstances(pmt.tvars);
313 tvars = tvars.appendList(tvars1);
314 mt = types.subst(pmt.qtype, pmt.tvars, tvars1);
315 }
317 // find out whether we need to go the slow route via infer
318 boolean instNeeded = tvars.tail != null/*inlined: tvars.nonEmpty()*/;
319 for (List<Type> l = argtypes;
320 l.tail != null/*inlined: l.nonEmpty()*/ && !instNeeded;
321 l = l.tail) {
322 if (l.head.tag == FORALL) instNeeded = true;
323 }
325 if (instNeeded)
326 return
327 infer.instantiateMethod(tvars,
328 (MethodType)mt,
329 argtypes,
330 allowBoxing,
331 useVarargs,
332 warn);
333 return
334 argumentsAcceptable(argtypes, mt.getParameterTypes(),
335 allowBoxing, useVarargs, warn)
336 ? mt
337 : null;
338 }
340 /** Same but returns null instead throwing a NoInstanceException
341 */
342 Type instantiate(Env<AttrContext> env,
343 Type site,
344 Symbol m,
345 List<Type> argtypes,
346 List<Type> typeargtypes,
347 boolean allowBoxing,
348 boolean useVarargs,
349 Warner warn) {
350 try {
351 return rawInstantiate(env, site, m, argtypes, typeargtypes,
352 allowBoxing, useVarargs, warn);
353 } catch (Infer.NoInstanceException ex) {
354 return null;
355 }
356 }
358 /** Check if a parameter list accepts a list of args.
359 */
360 boolean argumentsAcceptable(List<Type> argtypes,
361 List<Type> formals,
362 boolean allowBoxing,
363 boolean useVarargs,
364 Warner warn) {
365 Type varargsFormal = useVarargs ? formals.last() : null;
366 while (argtypes.nonEmpty() && formals.head != varargsFormal) {
367 boolean works = allowBoxing
368 ? types.isConvertible(argtypes.head, formals.head, warn)
369 : types.isSubtypeUnchecked(argtypes.head, formals.head, warn);
370 if (!works) return false;
371 argtypes = argtypes.tail;
372 formals = formals.tail;
373 }
374 if (formals.head != varargsFormal) return false; // not enough args
375 if (!useVarargs)
376 return argtypes.isEmpty();
377 Type elt = types.elemtype(varargsFormal);
378 while (argtypes.nonEmpty()) {
379 if (!types.isConvertible(argtypes.head, elt, warn))
380 return false;
381 argtypes = argtypes.tail;
382 }
383 return true;
384 }
386 /* ***************************************************************************
387 * Symbol lookup
388 * the following naming conventions for arguments are used
389 *
390 * env is the environment where the symbol was mentioned
391 * site is the type of which the symbol is a member
392 * name is the symbol's name
393 * if no arguments are given
394 * argtypes are the value arguments, if we search for a method
395 *
396 * If no symbol was found, a ResolveError detailing the problem is returned.
397 ****************************************************************************/
399 /** Find field. Synthetic fields are always skipped.
400 * @param env The current environment.
401 * @param site The original type from where the selection takes place.
402 * @param name The name of the field.
403 * @param c The class to search for the field. This is always
404 * a superclass or implemented interface of site's class.
405 */
406 Symbol findField(Env<AttrContext> env,
407 Type site,
408 Name name,
409 TypeSymbol c) {
410 while (c.type.tag == TYPEVAR)
411 c = c.type.getUpperBound().tsym;
412 Symbol bestSoFar = varNotFound;
413 Symbol sym;
414 Scope.Entry e = c.members().lookup(name);
415 while (e.scope != null) {
416 if (e.sym.kind == VAR && (e.sym.flags_field & SYNTHETIC) == 0) {
417 return isAccessible(env, site, e.sym)
418 ? e.sym : new AccessError(env, site, e.sym);
419 }
420 e = e.next();
421 }
422 Type st = types.supertype(c.type);
423 if (st != null && (st.tag == CLASS || st.tag == TYPEVAR)) {
424 sym = findField(env, site, name, st.tsym);
425 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
426 }
427 for (List<Type> l = types.interfaces(c.type);
428 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
429 l = l.tail) {
430 sym = findField(env, site, name, l.head.tsym);
431 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
432 sym.owner != bestSoFar.owner)
433 bestSoFar = new AmbiguityError(bestSoFar, sym);
434 else if (sym.kind < bestSoFar.kind)
435 bestSoFar = sym;
436 }
437 return bestSoFar;
438 }
440 /** Resolve a field identifier, throw a fatal error if not found.
441 * @param pos The position to use for error reporting.
442 * @param env The environment current at the method invocation.
443 * @param site The type of the qualifying expression, in which
444 * identifier is searched.
445 * @param name The identifier's name.
446 */
447 public VarSymbol resolveInternalField(DiagnosticPosition pos, Env<AttrContext> env,
448 Type site, Name name) {
449 Symbol sym = findField(env, site, name, site.tsym);
450 if (sym.kind == VAR) return (VarSymbol)sym;
451 else throw new FatalError(
452 JCDiagnostic.fragment("fatal.err.cant.locate.field",
453 name));
454 }
456 /** Find unqualified variable or field with given name.
457 * Synthetic fields always skipped.
458 * @param env The current environment.
459 * @param name The name of the variable or field.
460 */
461 Symbol findVar(Env<AttrContext> env, Name name) {
462 Symbol bestSoFar = varNotFound;
463 Symbol sym;
464 Env<AttrContext> env1 = env;
465 boolean staticOnly = false;
466 while (env1.outer != null) {
467 if (isStatic(env1)) staticOnly = true;
468 Scope.Entry e = env1.info.scope.lookup(name);
469 while (e.scope != null &&
470 (e.sym.kind != VAR ||
471 (e.sym.flags_field & SYNTHETIC) != 0))
472 e = e.next();
473 sym = (e.scope != null)
474 ? e.sym
475 : findField(
476 env1, env1.enclClass.sym.type, name, env1.enclClass.sym);
477 if (sym.exists()) {
478 if (staticOnly &&
479 sym.kind == VAR &&
480 sym.owner.kind == TYP &&
481 (sym.flags() & STATIC) == 0)
482 return new StaticError(sym);
483 else
484 return sym;
485 } else if (sym.kind < bestSoFar.kind) {
486 bestSoFar = sym;
487 }
489 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
490 env1 = env1.outer;
491 }
493 sym = findField(env, syms.predefClass.type, name, syms.predefClass);
494 if (sym.exists())
495 return sym;
496 if (bestSoFar.exists())
497 return bestSoFar;
499 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
500 for (; e.scope != null; e = e.next()) {
501 sym = e.sym;
502 Type origin = e.getOrigin().owner.type;
503 if (sym.kind == VAR) {
504 if (e.sym.owner.type != origin)
505 sym = sym.clone(e.getOrigin().owner);
506 return isAccessible(env, origin, sym)
507 ? sym : new AccessError(env, origin, sym);
508 }
509 }
511 Symbol origin = null;
512 e = env.toplevel.starImportScope.lookup(name);
513 for (; e.scope != null; e = e.next()) {
514 sym = e.sym;
515 if (sym.kind != VAR)
516 continue;
517 // invariant: sym.kind == VAR
518 if (bestSoFar.kind < AMBIGUOUS && sym.owner != bestSoFar.owner)
519 return new AmbiguityError(bestSoFar, sym);
520 else if (bestSoFar.kind >= VAR) {
521 origin = e.getOrigin().owner;
522 bestSoFar = isAccessible(env, origin.type, sym)
523 ? sym : new AccessError(env, origin.type, sym);
524 }
525 }
526 if (bestSoFar.kind == VAR && bestSoFar.owner.type != origin.type)
527 return bestSoFar.clone(origin);
528 else
529 return bestSoFar;
530 }
532 Warner noteWarner = new Warner();
534 /** Select the best method for a call site among two choices.
535 * @param env The current environment.
536 * @param site The original type from where the
537 * selection takes place.
538 * @param argtypes The invocation's value arguments,
539 * @param typeargtypes The invocation's type arguments,
540 * @param sym Proposed new best match.
541 * @param bestSoFar Previously found best match.
542 * @param allowBoxing Allow boxing conversions of arguments.
543 * @param useVarargs Box trailing arguments into an array for varargs.
544 */
545 Symbol selectBest(Env<AttrContext> env,
546 Type site,
547 List<Type> argtypes,
548 List<Type> typeargtypes,
549 Symbol sym,
550 Symbol bestSoFar,
551 boolean allowBoxing,
552 boolean useVarargs,
553 boolean operator) {
554 if (sym.kind == ERR) return bestSoFar;
555 if (!sym.isInheritedIn(site.tsym, types)) return bestSoFar;
556 assert sym.kind < AMBIGUOUS;
557 try {
558 if (rawInstantiate(env, site, sym, argtypes, typeargtypes,
559 allowBoxing, useVarargs, Warner.noWarnings) == null) {
560 // inapplicable
561 switch (bestSoFar.kind) {
562 case ABSENT_MTH: return wrongMethod.setWrongSym(sym);
563 case WRONG_MTH: return wrongMethods;
564 default: return bestSoFar;
565 }
566 }
567 } catch (Infer.NoInstanceException ex) {
568 switch (bestSoFar.kind) {
569 case ABSENT_MTH:
570 return wrongMethod.setWrongSym(sym, ex.getDiagnostic());
571 case WRONG_MTH:
572 return wrongMethods;
573 default:
574 return bestSoFar;
575 }
576 }
577 if (!isAccessible(env, site, sym)) {
578 return (bestSoFar.kind == ABSENT_MTH)
579 ? new AccessError(env, site, sym)
580 : bestSoFar;
581 }
582 return (bestSoFar.kind > AMBIGUOUS)
583 ? sym
584 : mostSpecific(sym, bestSoFar, env, site,
585 allowBoxing && operator, useVarargs);
586 }
588 /* Return the most specific of the two methods for a call,
589 * given that both are accessible and applicable.
590 * @param m1 A new candidate for most specific.
591 * @param m2 The previous most specific candidate.
592 * @param env The current environment.
593 * @param site The original type from where the selection
594 * takes place.
595 * @param allowBoxing Allow boxing conversions of arguments.
596 * @param useVarargs Box trailing arguments into an array for varargs.
597 */
598 Symbol mostSpecific(Symbol m1,
599 Symbol m2,
600 Env<AttrContext> env,
601 Type site,
602 boolean allowBoxing,
603 boolean useVarargs) {
604 switch (m2.kind) {
605 case MTH:
606 if (m1 == m2) return m1;
607 Type mt1 = types.memberType(site, m1);
608 noteWarner.unchecked = false;
609 boolean m1SignatureMoreSpecific =
610 (instantiate(env, site, m2, types.lowerBoundArgtypes(mt1), null,
611 allowBoxing, false, noteWarner) != null ||
612 useVarargs && instantiate(env, site, m2, types.lowerBoundArgtypes(mt1), null,
613 allowBoxing, true, noteWarner) != null) &&
614 !noteWarner.unchecked;
615 Type mt2 = types.memberType(site, m2);
616 noteWarner.unchecked = false;
617 boolean m2SignatureMoreSpecific =
618 (instantiate(env, site, m1, types.lowerBoundArgtypes(mt2), null,
619 allowBoxing, false, noteWarner) != null ||
620 useVarargs && instantiate(env, site, m1, types.lowerBoundArgtypes(mt2), null,
621 allowBoxing, true, noteWarner) != null) &&
622 !noteWarner.unchecked;
623 if (m1SignatureMoreSpecific && m2SignatureMoreSpecific) {
624 if (!types.overrideEquivalent(mt1, mt2))
625 return new AmbiguityError(m1, m2);
626 // same signature; select (a) the non-bridge method, or
627 // (b) the one that overrides the other, or (c) the concrete
628 // one, or (d) merge both abstract signatures
629 if ((m1.flags() & BRIDGE) != (m2.flags() & BRIDGE)) {
630 return ((m1.flags() & BRIDGE) != 0) ? m2 : m1;
631 }
632 // if one overrides or hides the other, use it
633 TypeSymbol m1Owner = (TypeSymbol)m1.owner;
634 TypeSymbol m2Owner = (TypeSymbol)m2.owner;
635 if (types.asSuper(m1Owner.type, m2Owner) != null &&
636 ((m1.owner.flags_field & INTERFACE) == 0 ||
637 (m2.owner.flags_field & INTERFACE) != 0) &&
638 m1.overrides(m2, m1Owner, types, false))
639 return m1;
640 if (types.asSuper(m2Owner.type, m1Owner) != null &&
641 ((m2.owner.flags_field & INTERFACE) == 0 ||
642 (m1.owner.flags_field & INTERFACE) != 0) &&
643 m2.overrides(m1, m2Owner, types, false))
644 return m2;
645 boolean m1Abstract = (m1.flags() & ABSTRACT) != 0;
646 boolean m2Abstract = (m2.flags() & ABSTRACT) != 0;
647 if (m1Abstract && !m2Abstract) return m2;
648 if (m2Abstract && !m1Abstract) return m1;
649 // both abstract or both concrete
650 if (!m1Abstract && !m2Abstract)
651 return new AmbiguityError(m1, m2);
652 // check for same erasure
653 if (!types.isSameType(m1.erasure(types), m2.erasure(types)))
654 return new AmbiguityError(m1, m2);
655 // both abstract, neither overridden; merge throws clause and result type
656 Symbol result;
657 Type result2 = mt2.getReturnType();;
658 if (mt2.tag == FORALL)
659 result2 = types.subst(result2, ((ForAll)mt2).tvars, ((ForAll)mt1).tvars);
660 if (types.isSubtype(mt1.getReturnType(), result2)) {
661 result = m1;
662 } else if (types.isSubtype(result2, mt1.getReturnType())) {
663 result = m2;
664 } else {
665 // Theoretically, this can't happen, but it is possible
666 // due to error recovery or mixing incompatible class files
667 return new AmbiguityError(m1, m2);
668 }
669 result = result.clone(result.owner);
670 result.type = (Type)result.type.clone();
671 result.type.setThrown(chk.intersect(mt1.getThrownTypes(),
672 mt2.getThrownTypes()));
673 return result;
674 }
675 if (m1SignatureMoreSpecific) return m1;
676 if (m2SignatureMoreSpecific) return m2;
677 return new AmbiguityError(m1, m2);
678 case AMBIGUOUS:
679 AmbiguityError e = (AmbiguityError)m2;
680 Symbol err1 = mostSpecific(m1, e.sym1, env, site, allowBoxing, useVarargs);
681 Symbol err2 = mostSpecific(m1, e.sym2, env, site, allowBoxing, useVarargs);
682 if (err1 == err2) return err1;
683 if (err1 == e.sym1 && err2 == e.sym2) return m2;
684 if (err1 instanceof AmbiguityError &&
685 err2 instanceof AmbiguityError &&
686 ((AmbiguityError)err1).sym1 == ((AmbiguityError)err2).sym1)
687 return new AmbiguityError(m1, m2);
688 else
689 return new AmbiguityError(err1, err2);
690 default:
691 throw new AssertionError();
692 }
693 }
695 /** Find best qualified method matching given name, type and value
696 * arguments.
697 * @param env The current environment.
698 * @param site The original type from where the selection
699 * takes place.
700 * @param name The method's name.
701 * @param argtypes The method's value arguments.
702 * @param typeargtypes The method's type arguments
703 * @param allowBoxing Allow boxing conversions of arguments.
704 * @param useVarargs Box trailing arguments into an array for varargs.
705 */
706 Symbol findMethod(Env<AttrContext> env,
707 Type site,
708 Name name,
709 List<Type> argtypes,
710 List<Type> typeargtypes,
711 boolean allowBoxing,
712 boolean useVarargs,
713 boolean operator) {
714 return findMethod(env,
715 site,
716 name,
717 argtypes,
718 typeargtypes,
719 site.tsym.type,
720 true,
721 methodNotFound,
722 allowBoxing,
723 useVarargs,
724 operator);
725 }
726 // where
727 private Symbol findMethod(Env<AttrContext> env,
728 Type site,
729 Name name,
730 List<Type> argtypes,
731 List<Type> typeargtypes,
732 Type intype,
733 boolean abstractok,
734 Symbol bestSoFar,
735 boolean allowBoxing,
736 boolean useVarargs,
737 boolean operator) {
738 for (Type ct = intype; ct.tag == CLASS || ct.tag == TYPEVAR; ct = types.supertype(ct)) {
739 while (ct.tag == TYPEVAR)
740 ct = ct.getUpperBound();
741 ClassSymbol c = (ClassSymbol)ct.tsym;
742 if ((c.flags() & (ABSTRACT | INTERFACE)) == 0)
743 abstractok = false;
744 for (Scope.Entry e = c.members().lookup(name);
745 e.scope != null;
746 e = e.next()) {
747 //- System.out.println(" e " + e.sym);
748 if (e.sym.kind == MTH &&
749 (e.sym.flags_field & SYNTHETIC) == 0) {
750 bestSoFar = selectBest(env, site, argtypes, typeargtypes,
751 e.sym, bestSoFar,
752 allowBoxing,
753 useVarargs,
754 operator);
755 }
756 }
757 //- System.out.println(" - " + bestSoFar);
758 if (abstractok) {
759 Symbol concrete = methodNotFound;
760 if ((bestSoFar.flags() & ABSTRACT) == 0)
761 concrete = bestSoFar;
762 for (List<Type> l = types.interfaces(c.type);
763 l.nonEmpty();
764 l = l.tail) {
765 bestSoFar = findMethod(env, site, name, argtypes,
766 typeargtypes,
767 l.head, abstractok, bestSoFar,
768 allowBoxing, useVarargs, operator);
769 }
770 if (concrete != bestSoFar &&
771 concrete.kind < ERR && bestSoFar.kind < ERR &&
772 types.isSubSignature(concrete.type, bestSoFar.type))
773 bestSoFar = concrete;
774 }
775 }
776 return bestSoFar;
777 }
779 /** Find unqualified method matching given name, type and value arguments.
780 * @param env The current environment.
781 * @param name The method's name.
782 * @param argtypes The method's value arguments.
783 * @param typeargtypes The method's type arguments.
784 * @param allowBoxing Allow boxing conversions of arguments.
785 * @param useVarargs Box trailing arguments into an array for varargs.
786 */
787 Symbol findFun(Env<AttrContext> env, Name name,
788 List<Type> argtypes, List<Type> typeargtypes,
789 boolean allowBoxing, boolean useVarargs) {
790 Symbol bestSoFar = methodNotFound;
791 Symbol sym;
792 Env<AttrContext> env1 = env;
793 boolean staticOnly = false;
794 while (env1.outer != null) {
795 if (isStatic(env1)) staticOnly = true;
796 sym = findMethod(
797 env1, env1.enclClass.sym.type, name, argtypes, typeargtypes,
798 allowBoxing, useVarargs, false);
799 if (sym.exists()) {
800 if (staticOnly &&
801 sym.kind == MTH &&
802 sym.owner.kind == TYP &&
803 (sym.flags() & STATIC) == 0) return new StaticError(sym);
804 else return sym;
805 } else if (sym.kind < bestSoFar.kind) {
806 bestSoFar = sym;
807 }
808 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
809 env1 = env1.outer;
810 }
812 sym = findMethod(env, syms.predefClass.type, name, argtypes,
813 typeargtypes, allowBoxing, useVarargs, false);
814 if (sym.exists())
815 return sym;
817 Scope.Entry e = env.toplevel.namedImportScope.lookup(name);
818 for (; e.scope != null; e = e.next()) {
819 sym = e.sym;
820 Type origin = e.getOrigin().owner.type;
821 if (sym.kind == MTH) {
822 if (e.sym.owner.type != origin)
823 sym = sym.clone(e.getOrigin().owner);
824 if (!isAccessible(env, origin, sym))
825 sym = new AccessError(env, origin, sym);
826 bestSoFar = selectBest(env, origin,
827 argtypes, typeargtypes,
828 sym, bestSoFar,
829 allowBoxing, useVarargs, false);
830 }
831 }
832 if (bestSoFar.exists())
833 return bestSoFar;
835 e = env.toplevel.starImportScope.lookup(name);
836 for (; e.scope != null; e = e.next()) {
837 sym = e.sym;
838 Type origin = e.getOrigin().owner.type;
839 if (sym.kind == MTH) {
840 if (e.sym.owner.type != origin)
841 sym = sym.clone(e.getOrigin().owner);
842 if (!isAccessible(env, origin, sym))
843 sym = new AccessError(env, origin, sym);
844 bestSoFar = selectBest(env, origin,
845 argtypes, typeargtypes,
846 sym, bestSoFar,
847 allowBoxing, useVarargs, false);
848 }
849 }
850 return bestSoFar;
851 }
853 /** Load toplevel or member class with given fully qualified name and
854 * verify that it is accessible.
855 * @param env The current environment.
856 * @param name The fully qualified name of the class to be loaded.
857 */
858 Symbol loadClass(Env<AttrContext> env, Name name) {
859 try {
860 ClassSymbol c = reader.loadClass(name);
861 return isAccessible(env, c) ? c : new AccessError(c);
862 } catch (ClassReader.BadClassFile err) {
863 throw err;
864 } catch (CompletionFailure ex) {
865 return typeNotFound;
866 }
867 }
869 /** Find qualified member type.
870 * @param env The current environment.
871 * @param site The original type from where the selection takes
872 * place.
873 * @param name The type's name.
874 * @param c The class to search for the member type. This is
875 * always a superclass or implemented interface of
876 * site's class.
877 */
878 Symbol findMemberType(Env<AttrContext> env,
879 Type site,
880 Name name,
881 TypeSymbol c) {
882 Symbol bestSoFar = typeNotFound;
883 Symbol sym;
884 Scope.Entry e = c.members().lookup(name);
885 while (e.scope != null) {
886 if (e.sym.kind == TYP) {
887 return isAccessible(env, site, e.sym)
888 ? e.sym
889 : new AccessError(env, site, e.sym);
890 }
891 e = e.next();
892 }
893 Type st = types.supertype(c.type);
894 if (st != null && st.tag == CLASS) {
895 sym = findMemberType(env, site, name, st.tsym);
896 if (sym.kind < bestSoFar.kind) bestSoFar = sym;
897 }
898 for (List<Type> l = types.interfaces(c.type);
899 bestSoFar.kind != AMBIGUOUS && l.nonEmpty();
900 l = l.tail) {
901 sym = findMemberType(env, site, name, l.head.tsym);
902 if (bestSoFar.kind < AMBIGUOUS && sym.kind < AMBIGUOUS &&
903 sym.owner != bestSoFar.owner)
904 bestSoFar = new AmbiguityError(bestSoFar, sym);
905 else if (sym.kind < bestSoFar.kind)
906 bestSoFar = sym;
907 }
908 return bestSoFar;
909 }
911 /** Find a global type in given scope and load corresponding class.
912 * @param env The current environment.
913 * @param scope The scope in which to look for the type.
914 * @param name The type's name.
915 */
916 Symbol findGlobalType(Env<AttrContext> env, Scope scope, Name name) {
917 Symbol bestSoFar = typeNotFound;
918 for (Scope.Entry e = scope.lookup(name); e.scope != null; e = e.next()) {
919 Symbol sym = loadClass(env, e.sym.flatName());
920 if (bestSoFar.kind == TYP && sym.kind == TYP &&
921 bestSoFar != sym)
922 return new AmbiguityError(bestSoFar, sym);
923 else if (sym.kind < bestSoFar.kind)
924 bestSoFar = sym;
925 }
926 return bestSoFar;
927 }
929 /** Find an unqualified type symbol.
930 * @param env The current environment.
931 * @param name The type's name.
932 */
933 Symbol findType(Env<AttrContext> env, Name name) {
934 Symbol bestSoFar = typeNotFound;
935 Symbol sym;
936 boolean staticOnly = false;
937 for (Env<AttrContext> env1 = env; env1.outer != null; env1 = env1.outer) {
938 if (isStatic(env1)) staticOnly = true;
939 for (Scope.Entry e = env1.info.scope.lookup(name);
940 e.scope != null;
941 e = e.next()) {
942 if (e.sym.kind == TYP) {
943 if (staticOnly &&
944 e.sym.type.tag == TYPEVAR &&
945 e.sym.owner.kind == TYP) return new StaticError(e.sym);
946 return e.sym;
947 }
948 }
950 sym = findMemberType(env1, env1.enclClass.sym.type, name,
951 env1.enclClass.sym);
952 if (staticOnly && sym.kind == TYP &&
953 sym.type.tag == CLASS &&
954 sym.type.getEnclosingType().tag == CLASS &&
955 env1.enclClass.sym.type.isParameterized() &&
956 sym.type.getEnclosingType().isParameterized())
957 return new StaticError(sym);
958 else if (sym.exists()) return sym;
959 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
961 JCClassDecl encl = env1.baseClause ? (JCClassDecl)env1.tree : env1.enclClass;
962 if ((encl.sym.flags() & STATIC) != 0)
963 staticOnly = true;
964 }
966 if (env.tree.getTag() != JCTree.IMPORT) {
967 sym = findGlobalType(env, env.toplevel.namedImportScope, name);
968 if (sym.exists()) return sym;
969 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
971 sym = findGlobalType(env, env.toplevel.packge.members(), name);
972 if (sym.exists()) return sym;
973 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
975 sym = findGlobalType(env, env.toplevel.starImportScope, name);
976 if (sym.exists()) return sym;
977 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
978 }
980 return bestSoFar;
981 }
983 /** Find an unqualified identifier which matches a specified kind set.
984 * @param env The current environment.
985 * @param name The indentifier's name.
986 * @param kind Indicates the possible symbol kinds
987 * (a subset of VAL, TYP, PCK).
988 */
989 Symbol findIdent(Env<AttrContext> env, Name name, int kind) {
990 Symbol bestSoFar = typeNotFound;
991 Symbol sym;
993 if ((kind & VAR) != 0) {
994 sym = findVar(env, name);
995 if (sym.exists()) return sym;
996 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
997 }
999 if ((kind & TYP) != 0) {
1000 sym = findType(env, name);
1001 if (sym.exists()) return sym;
1002 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1003 }
1005 if ((kind & PCK) != 0) return reader.enterPackage(name);
1006 else return bestSoFar;
1007 }
1009 /** Find an identifier in a package which matches a specified kind set.
1010 * @param env The current environment.
1011 * @param name The identifier's name.
1012 * @param kind Indicates the possible symbol kinds
1013 * (a nonempty subset of TYP, PCK).
1014 */
1015 Symbol findIdentInPackage(Env<AttrContext> env, TypeSymbol pck,
1016 Name name, int kind) {
1017 Name fullname = TypeSymbol.formFullName(name, pck);
1018 Symbol bestSoFar = typeNotFound;
1019 PackageSymbol pack = null;
1020 if ((kind & PCK) != 0) {
1021 pack = reader.enterPackage(fullname);
1022 if (pack.exists()) return pack;
1023 }
1024 if ((kind & TYP) != 0) {
1025 Symbol sym = loadClass(env, fullname);
1026 if (sym.exists()) {
1027 // don't allow programs to use flatnames
1028 if (name == sym.name) return sym;
1029 }
1030 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1031 }
1032 return (pack != null) ? pack : bestSoFar;
1033 }
1035 /** Find an identifier among the members of a given type `site'.
1036 * @param env The current environment.
1037 * @param site The type containing the symbol to be found.
1038 * @param name The identifier's name.
1039 * @param kind Indicates the possible symbol kinds
1040 * (a subset of VAL, TYP).
1041 */
1042 Symbol findIdentInType(Env<AttrContext> env, Type site,
1043 Name name, int kind) {
1044 Symbol bestSoFar = typeNotFound;
1045 Symbol sym;
1046 if ((kind & VAR) != 0) {
1047 sym = findField(env, site, name, site.tsym);
1048 if (sym.exists()) return sym;
1049 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1050 }
1052 if ((kind & TYP) != 0) {
1053 sym = findMemberType(env, site, name, site.tsym);
1054 if (sym.exists()) return sym;
1055 else if (sym.kind < bestSoFar.kind) bestSoFar = sym;
1056 }
1057 return bestSoFar;
1058 }
1060 /* ***************************************************************************
1061 * Access checking
1062 * The following methods convert ResolveErrors to ErrorSymbols, issuing
1063 * an error message in the process
1064 ****************************************************************************/
1066 /** If `sym' is a bad symbol: report error and return errSymbol
1067 * else pass through unchanged,
1068 * additional arguments duplicate what has been used in trying to find the
1069 * symbol (--> flyweight pattern). This improves performance since we
1070 * expect misses to happen frequently.
1071 *
1072 * @param sym The symbol that was found, or a ResolveError.
1073 * @param pos The position to use for error reporting.
1074 * @param site The original type from where the selection took place.
1075 * @param name The symbol's name.
1076 * @param argtypes The invocation's value arguments,
1077 * if we looked for a method.
1078 * @param typeargtypes The invocation's type arguments,
1079 * if we looked for a method.
1080 */
1081 Symbol access(Symbol sym,
1082 DiagnosticPosition pos,
1083 Type site,
1084 Name name,
1085 boolean qualified,
1086 List<Type> argtypes,
1087 List<Type> typeargtypes) {
1088 if (sym.kind >= AMBIGUOUS) {
1089 // printscopes(site.tsym.members());//DEBUG
1090 if (!site.isErroneous() &&
1091 !Type.isErroneous(argtypes) &&
1092 (typeargtypes==null || !Type.isErroneous(typeargtypes)))
1093 ((ResolveError)sym).report(log, pos, site, name, argtypes, typeargtypes);
1094 do {
1095 sym = ((ResolveError)sym).sym;
1096 } while (sym.kind >= AMBIGUOUS);
1097 if (sym == syms.errSymbol // preserve the symbol name through errors
1098 || ((sym.kind & ERRONEOUS) == 0 // make sure an error symbol is returned
1099 && (sym.kind & TYP) != 0))
1100 sym = new ErrorType(name, qualified?site.tsym:syms.noSymbol).tsym;
1101 }
1102 return sym;
1103 }
1105 /** Same as above, but without type arguments and arguments.
1106 */
1107 Symbol access(Symbol sym,
1108 DiagnosticPosition pos,
1109 Type site,
1110 Name name,
1111 boolean qualified) {
1112 if (sym.kind >= AMBIGUOUS)
1113 return access(sym, pos, site, name, qualified, List.<Type>nil(), null);
1114 else
1115 return sym;
1116 }
1118 /** Check that sym is not an abstract method.
1119 */
1120 void checkNonAbstract(DiagnosticPosition pos, Symbol sym) {
1121 if ((sym.flags() & ABSTRACT) != 0)
1122 log.error(pos, "abstract.cant.be.accessed.directly",
1123 kindName(sym), sym, sym.location());
1124 }
1126 /* ***************************************************************************
1127 * Debugging
1128 ****************************************************************************/
1130 /** print all scopes starting with scope s and proceeding outwards.
1131 * used for debugging.
1132 */
1133 public void printscopes(Scope s) {
1134 while (s != null) {
1135 if (s.owner != null)
1136 System.err.print(s.owner + ": ");
1137 for (Scope.Entry e = s.elems; e != null; e = e.sibling) {
1138 if ((e.sym.flags() & ABSTRACT) != 0)
1139 System.err.print("abstract ");
1140 System.err.print(e.sym + " ");
1141 }
1142 System.err.println();
1143 s = s.next;
1144 }
1145 }
1147 void printscopes(Env<AttrContext> env) {
1148 while (env.outer != null) {
1149 System.err.println("------------------------------");
1150 printscopes(env.info.scope);
1151 env = env.outer;
1152 }
1153 }
1155 public void printscopes(Type t) {
1156 while (t.tag == CLASS) {
1157 printscopes(t.tsym.members());
1158 t = types.supertype(t);
1159 }
1160 }
1162 /* ***************************************************************************
1163 * Name resolution
1164 * Naming conventions are as for symbol lookup
1165 * Unlike the find... methods these methods will report access errors
1166 ****************************************************************************/
1168 /** Resolve an unqualified (non-method) identifier.
1169 * @param pos The position to use for error reporting.
1170 * @param env The environment current at the identifier use.
1171 * @param name The identifier's name.
1172 * @param kind The set of admissible symbol kinds for the identifier.
1173 */
1174 Symbol resolveIdent(DiagnosticPosition pos, Env<AttrContext> env,
1175 Name name, int kind) {
1176 return access(
1177 findIdent(env, name, kind),
1178 pos, env.enclClass.sym.type, name, false);
1179 }
1181 /** Resolve an unqualified method identifier.
1182 * @param pos The position to use for error reporting.
1183 * @param env The environment current at the method invocation.
1184 * @param name The identifier's name.
1185 * @param argtypes The types of the invocation's value arguments.
1186 * @param typeargtypes The types of the invocation's type arguments.
1187 */
1188 Symbol resolveMethod(DiagnosticPosition pos,
1189 Env<AttrContext> env,
1190 Name name,
1191 List<Type> argtypes,
1192 List<Type> typeargtypes) {
1193 Symbol sym = findFun(env, name, argtypes, typeargtypes, false, env.info.varArgs=false);
1194 if (varargsEnabled && sym.kind >= WRONG_MTHS) {
1195 sym = findFun(env, name, argtypes, typeargtypes, true, false);
1196 if (sym.kind >= WRONG_MTHS)
1197 sym = findFun(env, name, argtypes, typeargtypes, true, env.info.varArgs=true);
1198 }
1199 if (sym.kind >= AMBIGUOUS) {
1200 sym = access(
1201 sym, pos, env.enclClass.sym.type, name, false, argtypes, typeargtypes);
1202 }
1203 return sym;
1204 }
1206 /** Resolve a qualified method identifier
1207 * @param pos The position to use for error reporting.
1208 * @param env The environment current at the method invocation.
1209 * @param site The type of the qualifying expression, in which
1210 * identifier is searched.
1211 * @param name The identifier's name.
1212 * @param argtypes The types of the invocation's value arguments.
1213 * @param typeargtypes The types of the invocation's type arguments.
1214 */
1215 Symbol resolveQualifiedMethod(DiagnosticPosition pos, Env<AttrContext> env,
1216 Type site, Name name, List<Type> argtypes,
1217 List<Type> typeargtypes) {
1218 Symbol sym = findMethod(env, site, name, argtypes, typeargtypes, false,
1219 env.info.varArgs=false, false);
1220 if (varargsEnabled && sym.kind >= WRONG_MTHS) {
1221 sym = findMethod(env, site, name, argtypes, typeargtypes, true,
1222 false, false);
1223 if (sym.kind >= WRONG_MTHS)
1224 sym = findMethod(env, site, name, argtypes, typeargtypes, true,
1225 env.info.varArgs=true, false);
1226 }
1227 if (sym.kind >= AMBIGUOUS) {
1228 sym = access(sym, pos, site, name, true, argtypes, typeargtypes);
1229 }
1230 return sym;
1231 }
1233 /** Resolve a qualified method identifier, throw a fatal error if not
1234 * found.
1235 * @param pos The position to use for error reporting.
1236 * @param env The environment current at the method invocation.
1237 * @param site The type of the qualifying expression, in which
1238 * identifier is searched.
1239 * @param name The identifier's name.
1240 * @param argtypes The types of the invocation's value arguments.
1241 * @param typeargtypes The types of the invocation's type arguments.
1242 */
1243 public MethodSymbol resolveInternalMethod(DiagnosticPosition pos, Env<AttrContext> env,
1244 Type site, Name name,
1245 List<Type> argtypes,
1246 List<Type> typeargtypes) {
1247 Symbol sym = resolveQualifiedMethod(
1248 pos, env, site, name, argtypes, typeargtypes);
1249 if (sym.kind == MTH) return (MethodSymbol)sym;
1250 else throw new FatalError(
1251 JCDiagnostic.fragment("fatal.err.cant.locate.meth",
1252 name));
1253 }
1255 /** Resolve constructor.
1256 * @param pos The position to use for error reporting.
1257 * @param env The environment current at the constructor invocation.
1258 * @param site The type of class for which a constructor is searched.
1259 * @param argtypes The types of the constructor invocation's value
1260 * arguments.
1261 * @param typeargtypes The types of the constructor invocation's type
1262 * arguments.
1263 */
1264 Symbol resolveConstructor(DiagnosticPosition pos,
1265 Env<AttrContext> env,
1266 Type site,
1267 List<Type> argtypes,
1268 List<Type> typeargtypes) {
1269 Symbol sym = resolveConstructor(pos, env, site, argtypes, typeargtypes, false, env.info.varArgs=false);
1270 if (varargsEnabled && sym.kind >= WRONG_MTHS) {
1271 sym = resolveConstructor(pos, env, site, argtypes, typeargtypes, true, false);
1272 if (sym.kind >= WRONG_MTHS)
1273 sym = resolveConstructor(pos, env, site, argtypes, typeargtypes, true, env.info.varArgs=true);
1274 }
1275 if (sym.kind >= AMBIGUOUS) {
1276 sym = access(sym, pos, site, names.init, true, argtypes, typeargtypes);
1277 }
1278 return sym;
1279 }
1281 /** Resolve constructor.
1282 * @param pos The position to use for error reporting.
1283 * @param env The environment current at the constructor invocation.
1284 * @param site The type of class for which a constructor is searched.
1285 * @param argtypes The types of the constructor invocation's value
1286 * arguments.
1287 * @param typeargtypes The types of the constructor invocation's type
1288 * arguments.
1289 * @param allowBoxing Allow boxing and varargs conversions.
1290 * @param useVarargs Box trailing arguments into an array for varargs.
1291 */
1292 Symbol resolveConstructor(DiagnosticPosition pos, Env<AttrContext> env,
1293 Type site, List<Type> argtypes,
1294 List<Type> typeargtypes,
1295 boolean allowBoxing,
1296 boolean useVarargs) {
1297 Symbol sym = findMethod(env, site,
1298 names.init, argtypes,
1299 typeargtypes, allowBoxing,
1300 useVarargs, false);
1301 if ((sym.flags() & DEPRECATED) != 0 &&
1302 (env.info.scope.owner.flags() & DEPRECATED) == 0 &&
1303 env.info.scope.owner.outermostClass() != sym.outermostClass())
1304 chk.warnDeprecated(pos, sym);
1305 return sym;
1306 }
1308 /** Resolve a constructor, throw a fatal error if not found.
1309 * @param pos The position to use for error reporting.
1310 * @param env The environment current at the method invocation.
1311 * @param site The type to be constructed.
1312 * @param argtypes The types of the invocation's value arguments.
1313 * @param typeargtypes The types of the invocation's type arguments.
1314 */
1315 public MethodSymbol resolveInternalConstructor(DiagnosticPosition pos, Env<AttrContext> env,
1316 Type site,
1317 List<Type> argtypes,
1318 List<Type> typeargtypes) {
1319 Symbol sym = resolveConstructor(
1320 pos, env, site, argtypes, typeargtypes);
1321 if (sym.kind == MTH) return (MethodSymbol)sym;
1322 else throw new FatalError(
1323 JCDiagnostic.fragment("fatal.err.cant.locate.ctor", site));
1324 }
1326 /** Resolve operator.
1327 * @param pos The position to use for error reporting.
1328 * @param optag The tag of the operation tree.
1329 * @param env The environment current at the operation.
1330 * @param argtypes The types of the operands.
1331 */
1332 Symbol resolveOperator(DiagnosticPosition pos, int optag,
1333 Env<AttrContext> env, List<Type> argtypes) {
1334 Name name = treeinfo.operatorName(optag);
1335 Symbol sym = findMethod(env, syms.predefClass.type, name, argtypes,
1336 null, false, false, true);
1337 if (boxingEnabled && sym.kind >= WRONG_MTHS)
1338 sym = findMethod(env, syms.predefClass.type, name, argtypes,
1339 null, true, false, true);
1340 return access(sym, pos, env.enclClass.sym.type, name,
1341 false, argtypes, null);
1342 }
1344 /** Resolve operator.
1345 * @param pos The position to use for error reporting.
1346 * @param optag The tag of the operation tree.
1347 * @param env The environment current at the operation.
1348 * @param arg The type of the operand.
1349 */
1350 Symbol resolveUnaryOperator(DiagnosticPosition pos, int optag, Env<AttrContext> env, Type arg) {
1351 return resolveOperator(pos, optag, env, List.of(arg));
1352 }
1354 /** Resolve binary operator.
1355 * @param pos The position to use for error reporting.
1356 * @param optag The tag of the operation tree.
1357 * @param env The environment current at the operation.
1358 * @param left The types of the left operand.
1359 * @param right The types of the right operand.
1360 */
1361 Symbol resolveBinaryOperator(DiagnosticPosition pos,
1362 int optag,
1363 Env<AttrContext> env,
1364 Type left,
1365 Type right) {
1366 return resolveOperator(pos, optag, env, List.of(left, right));
1367 }
1369 /**
1370 * Resolve `c.name' where name == this or name == super.
1371 * @param pos The position to use for error reporting.
1372 * @param env The environment current at the expression.
1373 * @param c The qualifier.
1374 * @param name The identifier's name.
1375 */
1376 Symbol resolveSelf(DiagnosticPosition pos,
1377 Env<AttrContext> env,
1378 TypeSymbol c,
1379 Name name) {
1380 Env<AttrContext> env1 = env;
1381 boolean staticOnly = false;
1382 while (env1.outer != null) {
1383 if (isStatic(env1)) staticOnly = true;
1384 if (env1.enclClass.sym == c) {
1385 Symbol sym = env1.info.scope.lookup(name).sym;
1386 if (sym != null) {
1387 if (staticOnly) sym = new StaticError(sym);
1388 return access(sym, pos, env.enclClass.sym.type,
1389 name, true);
1390 }
1391 }
1392 if ((env1.enclClass.sym.flags() & STATIC) != 0) staticOnly = true;
1393 env1 = env1.outer;
1394 }
1395 log.error(pos, "not.encl.class", c);
1396 return syms.errSymbol;
1397 }
1399 /**
1400 * Resolve `c.this' for an enclosing class c that contains the
1401 * named member.
1402 * @param pos The position to use for error reporting.
1403 * @param env The environment current at the expression.
1404 * @param member The member that must be contained in the result.
1405 */
1406 Symbol resolveSelfContaining(DiagnosticPosition pos,
1407 Env<AttrContext> env,
1408 Symbol member) {
1409 Name name = names._this;
1410 Env<AttrContext> env1 = env;
1411 boolean staticOnly = false;
1412 while (env1.outer != null) {
1413 if (isStatic(env1)) staticOnly = true;
1414 if (env1.enclClass.sym.isSubClass(member.owner, types) &&
1415 isAccessible(env, env1.enclClass.sym.type, member)) {
1416 Symbol sym = env1.info.scope.lookup(name).sym;
1417 if (sym != null) {
1418 if (staticOnly) sym = new StaticError(sym);
1419 return access(sym, pos, env.enclClass.sym.type,
1420 name, true);
1421 }
1422 }
1423 if ((env1.enclClass.sym.flags() & STATIC) != 0)
1424 staticOnly = true;
1425 env1 = env1.outer;
1426 }
1427 log.error(pos, "encl.class.required", member);
1428 return syms.errSymbol;
1429 }
1431 /**
1432 * Resolve an appropriate implicit this instance for t's container.
1433 * JLS2 8.8.5.1 and 15.9.2
1434 */
1435 Type resolveImplicitThis(DiagnosticPosition pos, Env<AttrContext> env, Type t) {
1436 Type thisType = (((t.tsym.owner.kind & (MTH|VAR)) != 0)
1437 ? resolveSelf(pos, env, t.getEnclosingType().tsym, names._this)
1438 : resolveSelfContaining(pos, env, t.tsym)).type;
1439 if (env.info.isSelfCall && thisType.tsym == env.enclClass.sym)
1440 log.error(pos, "cant.ref.before.ctor.called", "this");
1441 return thisType;
1442 }
1444 /* ***************************************************************************
1445 * Methods related to kinds
1446 ****************************************************************************/
1448 /** A localized string describing a given kind.
1449 */
1450 static JCDiagnostic kindName(int kind) {
1451 switch (kind) {
1452 case PCK: return JCDiagnostic.fragment("kindname.package");
1453 case TYP: return JCDiagnostic.fragment("kindname.class");
1454 case VAR: return JCDiagnostic.fragment("kindname.variable");
1455 case VAL: return JCDiagnostic.fragment("kindname.value");
1456 case MTH: return JCDiagnostic.fragment("kindname.method");
1457 default : return JCDiagnostic.fragment("kindname",
1458 Integer.toString(kind)); //debug
1459 }
1460 }
1462 static JCDiagnostic kindName(Symbol sym) {
1463 switch (sym.getKind()) {
1464 case PACKAGE:
1465 return JCDiagnostic.fragment("kindname.package");
1467 case ENUM:
1468 case ANNOTATION_TYPE:
1469 case INTERFACE:
1470 case CLASS:
1471 return JCDiagnostic.fragment("kindname.class");
1473 case TYPE_PARAMETER:
1474 return JCDiagnostic.fragment("kindname.type.variable");
1476 case ENUM_CONSTANT:
1477 case FIELD:
1478 case PARAMETER:
1479 case LOCAL_VARIABLE:
1480 case EXCEPTION_PARAMETER:
1481 return JCDiagnostic.fragment("kindname.variable");
1483 case METHOD:
1484 case CONSTRUCTOR:
1485 case STATIC_INIT:
1486 case INSTANCE_INIT:
1487 return JCDiagnostic.fragment("kindname.method");
1489 default:
1490 if (sym.kind == VAL)
1491 // I don't think this can happen but it can't harm
1492 // playing it safe --ahe
1493 return JCDiagnostic.fragment("kindname.value");
1494 else
1495 return JCDiagnostic.fragment("kindname", sym.getKind()); // debug
1496 }
1497 }
1499 /** A localized string describing a given set of kinds.
1500 */
1501 static JCDiagnostic kindNames(int kind) {
1502 StringBuffer key = new StringBuffer();
1503 key.append("kindname");
1504 if ((kind & VAL) != 0)
1505 key.append(((kind & VAL) == VAR) ? ".variable" : ".value");
1506 if ((kind & MTH) != 0) key.append(".method");
1507 if ((kind & TYP) != 0) key.append(".class");
1508 if ((kind & PCK) != 0) key.append(".package");
1509 return JCDiagnostic.fragment(key.toString(), kind);
1510 }
1512 /** A localized string describing the kind -- either class or interface --
1513 * of a given type.
1514 */
1515 static JCDiagnostic typeKindName(Type t) {
1516 if (t.tag == TYPEVAR ||
1517 t.tag == CLASS && (t.tsym.flags() & COMPOUND) != 0)
1518 return JCDiagnostic.fragment("kindname.type.variable.bound");
1519 else if (t.tag == PACKAGE)
1520 return JCDiagnostic.fragment("kindname.package");
1521 else if ((t.tsym.flags_field & ANNOTATION) != 0)
1522 return JCDiagnostic.fragment("kindname.annotation");
1523 else if ((t.tsym.flags_field & INTERFACE) != 0)
1524 return JCDiagnostic.fragment("kindname.interface");
1525 else
1526 return JCDiagnostic.fragment("kindname.class");
1527 }
1529 /** A localized string describing the kind of a missing symbol, given an
1530 * error kind.
1531 */
1532 static JCDiagnostic absentKindName(int kind) {
1533 switch (kind) {
1534 case ABSENT_VAR:
1535 return JCDiagnostic.fragment("kindname.variable");
1536 case WRONG_MTHS: case WRONG_MTH: case ABSENT_MTH:
1537 return JCDiagnostic.fragment("kindname.method");
1538 case ABSENT_TYP:
1539 return JCDiagnostic.fragment("kindname.class");
1540 default:
1541 return JCDiagnostic.fragment("kindname", kind);
1542 }
1543 }
1545 /* ***************************************************************************
1546 * ResolveError classes, indicating error situations when accessing symbols
1547 ****************************************************************************/
1549 public void logAccessError(Env<AttrContext> env, JCTree tree, Type type) {
1550 AccessError error = new AccessError(env, type.getEnclosingType(), type.tsym);
1551 error.report(log, tree.pos(), type.getEnclosingType(), null, null, null);
1552 }
1554 /** Root class for resolve errors.
1555 * Instances of this class indicate "Symbol not found".
1556 * Instances of subclass indicate other errors.
1557 */
1558 private class ResolveError extends Symbol {
1560 ResolveError(int kind, Symbol sym, String debugName) {
1561 super(kind, 0, null, null, null);
1562 this.debugName = debugName;
1563 this.sym = sym;
1564 }
1566 /** The name of the kind of error, for debugging only.
1567 */
1568 final String debugName;
1570 /** The symbol that was determined by resolution, or errSymbol if none
1571 * was found.
1572 */
1573 final Symbol sym;
1575 /** The symbol that was a close mismatch, or null if none was found.
1576 * wrongSym is currently set if a simgle method with the correct name, but
1577 * the wrong parameters was found.
1578 */
1579 Symbol wrongSym;
1581 /** An auxiliary explanation set in case of instantiation errors.
1582 */
1583 JCDiagnostic explanation;
1586 public <R, P> R accept(ElementVisitor<R, P> v, P p) {
1587 throw new AssertionError();
1588 }
1590 /** Print the (debug only) name of the kind of error.
1591 */
1592 public String toString() {
1593 return debugName + " wrongSym=" + wrongSym + " explanation=" + explanation;
1594 }
1596 /** Update wrongSym and explanation and return this.
1597 */
1598 ResolveError setWrongSym(Symbol sym, JCDiagnostic explanation) {
1599 this.wrongSym = sym;
1600 this.explanation = explanation;
1601 return this;
1602 }
1604 /** Update wrongSym and return this.
1605 */
1606 ResolveError setWrongSym(Symbol sym) {
1607 this.wrongSym = sym;
1608 this.explanation = null;
1609 return this;
1610 }
1612 public boolean exists() {
1613 switch (kind) {
1614 case HIDDEN:
1615 case ABSENT_VAR:
1616 case ABSENT_MTH:
1617 case ABSENT_TYP:
1618 return false;
1619 default:
1620 return true;
1621 }
1622 }
1624 /** Report error.
1625 * @param log The error log to be used for error reporting.
1626 * @param pos The position to be used for error reporting.
1627 * @param site The original type from where the selection took place.
1628 * @param name The name of the symbol to be resolved.
1629 * @param argtypes The invocation's value arguments,
1630 * if we looked for a method.
1631 * @param typeargtypes The invocation's type arguments,
1632 * if we looked for a method.
1633 */
1634 void report(Log log, DiagnosticPosition pos, Type site, Name name,
1635 List<Type> argtypes, List<Type> typeargtypes) {
1636 if (name != name.table.error) {
1637 JCDiagnostic kindname = absentKindName(kind);
1638 String idname = name.toString();
1639 String args = "";
1640 String typeargs = "";
1641 if (kind >= WRONG_MTHS && kind <= ABSENT_MTH) {
1642 if (isOperator(name)) {
1643 log.error(pos, "operator.cant.be.applied",
1644 name, Type.toString(argtypes));
1645 return;
1646 }
1647 if (name == name.table.init) {
1648 kindname = JCDiagnostic.fragment("kindname.constructor");
1649 idname = site.tsym.name.toString();
1650 }
1651 args = "(" + Type.toString(argtypes) + ")";
1652 if (typeargtypes != null && typeargtypes.nonEmpty())
1653 typeargs = "<" + Type.toString(typeargtypes) + ">";
1654 }
1655 if (kind == WRONG_MTH) {
1656 log.error(pos,
1657 "cant.apply.symbol" + (explanation != null ? ".1" : ""),
1658 wrongSym.asMemberOf(site, types),
1659 wrongSym.location(site, types),
1660 typeargs,
1661 Type.toString(argtypes),
1662 explanation);
1663 } else if (site.tsym.name.len != 0) {
1664 if (site.tsym.kind == PCK && !site.tsym.exists())
1665 log.error(pos, "doesnt.exist", site.tsym);
1666 else
1667 log.error(pos, "cant.resolve.location",
1668 kindname, idname, args, typeargs,
1669 typeKindName(site), site);
1670 } else {
1671 log.error(pos, "cant.resolve", kindname, idname, args, typeargs);
1672 }
1673 }
1674 }
1675 //where
1676 /** A name designates an operator if it consists
1677 * of a non-empty sequence of operator symbols +-~!/*%&|^<>=
1678 */
1679 boolean isOperator(Name name) {
1680 int i = 0;
1681 while (i < name.len &&
1682 "+-~!*/%&|^<>=".indexOf(name.byteAt(i)) >= 0) i++;
1683 return i > 0 && i == name.len;
1684 }
1685 }
1687 /** Resolve error class indicating that a symbol is not accessible.
1688 */
1689 class AccessError extends ResolveError {
1691 AccessError(Symbol sym) {
1692 this(null, null, sym);
1693 }
1695 AccessError(Env<AttrContext> env, Type site, Symbol sym) {
1696 super(HIDDEN, sym, "access error");
1697 this.env = env;
1698 this.site = site;
1699 if (debugResolve)
1700 log.error("proc.messager", sym + " @ " + site + " is inaccessible.");
1701 }
1703 private Env<AttrContext> env;
1704 private Type site;
1706 /** Report error.
1707 * @param log The error log to be used for error reporting.
1708 * @param pos The position to be used for error reporting.
1709 * @param site The original type from where the selection took place.
1710 * @param name The name of the symbol to be resolved.
1711 * @param argtypes The invocation's value arguments,
1712 * if we looked for a method.
1713 * @param typeargtypes The invocation's type arguments,
1714 * if we looked for a method.
1715 */
1716 void report(Log log, DiagnosticPosition pos, Type site, Name name,
1717 List<Type> argtypes, List<Type> typeargtypes) {
1718 if (sym.owner.type.tag != ERROR) {
1719 if (sym.name == sym.name.table.init && sym.owner != site.tsym)
1720 new ResolveError(ABSENT_MTH, sym.owner, "absent method " + sym).report(
1721 log, pos, site, name, argtypes, typeargtypes);
1722 if ((sym.flags() & PUBLIC) != 0
1723 || (env != null && this.site != null
1724 && !isAccessible(env, this.site)))
1725 log.error(pos, "not.def.access.class.intf.cant.access",
1726 sym, sym.location());
1727 else if ((sym.flags() & (PRIVATE | PROTECTED)) != 0)
1728 log.error(pos, "report.access", sym,
1729 TreeInfo.flagNames(sym.flags() & (PRIVATE | PROTECTED)),
1730 sym.location());
1731 else
1732 log.error(pos, "not.def.public.cant.access",
1733 sym, sym.location());
1734 }
1735 }
1736 }
1738 /** Resolve error class indicating that an instance member was accessed
1739 * from a static context.
1740 */
1741 class StaticError extends ResolveError {
1742 StaticError(Symbol sym) {
1743 super(STATICERR, sym, "static error");
1744 }
1746 /** Report error.
1747 * @param log The error log to be used for error reporting.
1748 * @param pos The position to be used for error reporting.
1749 * @param site The original type from where the selection took place.
1750 * @param name The name of the symbol to be resolved.
1751 * @param argtypes The invocation's value arguments,
1752 * if we looked for a method.
1753 * @param typeargtypes The invocation's type arguments,
1754 * if we looked for a method.
1755 */
1756 void report(Log log,
1757 DiagnosticPosition pos,
1758 Type site,
1759 Name name,
1760 List<Type> argtypes,
1761 List<Type> typeargtypes) {
1762 String symstr = ((sym.kind == TYP && sym.type.tag == CLASS)
1763 ? types.erasure(sym.type)
1764 : sym).toString();
1765 log.error(pos, "non-static.cant.be.ref",
1766 kindName(sym), symstr);
1767 }
1768 }
1770 /** Resolve error class indicating an ambiguous reference.
1771 */
1772 class AmbiguityError extends ResolveError {
1773 Symbol sym1;
1774 Symbol sym2;
1776 AmbiguityError(Symbol sym1, Symbol sym2) {
1777 super(AMBIGUOUS, sym1, "ambiguity error");
1778 this.sym1 = sym1;
1779 this.sym2 = sym2;
1780 }
1782 /** Report error.
1783 * @param log The error log to be used for error reporting.
1784 * @param pos The position to be used for error reporting.
1785 * @param site The original type from where the selection took place.
1786 * @param name The name of the symbol to be resolved.
1787 * @param argtypes The invocation's value arguments,
1788 * if we looked for a method.
1789 * @param typeargtypes The invocation's type arguments,
1790 * if we looked for a method.
1791 */
1792 void report(Log log, DiagnosticPosition pos, Type site, Name name,
1793 List<Type> argtypes, List<Type> typeargtypes) {
1794 AmbiguityError pair = this;
1795 while (true) {
1796 if (pair.sym1.kind == AMBIGUOUS)
1797 pair = (AmbiguityError)pair.sym1;
1798 else if (pair.sym2.kind == AMBIGUOUS)
1799 pair = (AmbiguityError)pair.sym2;
1800 else break;
1801 }
1802 Name sname = pair.sym1.name;
1803 if (sname == sname.table.init) sname = pair.sym1.owner.name;
1804 log.error(pos, "ref.ambiguous", sname,
1805 kindName(pair.sym1),
1806 pair.sym1,
1807 pair.sym1.location(site, types),
1808 kindName(pair.sym2),
1809 pair.sym2,
1810 pair.sym2.location(site, types));
1811 }
1812 }
1813 }
