1 /*
2 * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.code;
27
28 import java.lang.ref.SoftReference;
29 import java.util.HashSet;
30 import java.util.HashMap;
31 import java.util.Locale;
32 import java.util.Map;
33 import java.util.Optional;
34 import java.util.Set;
35 import java.util.WeakHashMap;
36 import java.util.function.BiPredicate;
37 import java.util.function.Function;
38 import java.util.function.Predicate;
39 import java.util.stream.Collector;
40
41 import javax.tools.JavaFileObject;
42
43 import com.sun.tools.javac.code.Attribute.RetentionPolicy;
44 import com.sun.tools.javac.code.Lint.LintCategory;
45 import com.sun.tools.javac.code.Source.Feature;
46 import com.sun.tools.javac.code.Type.UndetVar.InferenceBound;
47 import com.sun.tools.javac.code.TypeMetadata.Entry.Kind;
48 import com.sun.tools.javac.comp.AttrContext;
49 import com.sun.tools.javac.comp.Check;
50 import com.sun.tools.javac.comp.Enter;
51 import com.sun.tools.javac.comp.Env;
52 import com.sun.tools.javac.jvm.ClassFile;
53 import com.sun.tools.javac.util.*;
54
55 import static com.sun.tools.javac.code.BoundKind.*;
56 import static com.sun.tools.javac.code.Flags.*;
57 import static com.sun.tools.javac.code.Kinds.Kind.*;
58 import static com.sun.tools.javac.code.Scope.*;
59 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
60 import static com.sun.tools.javac.code.Symbol.*;
61 import static com.sun.tools.javac.code.Type.*;
62 import static com.sun.tools.javac.code.TypeTag.*;
63 import static com.sun.tools.javac.jvm.ClassFile.externalize;
64 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
65
66 /**
67 * Utility class containing various operations on types.
68 *
69 * <p>Unless other names are more illustrative, the following naming
70 * conventions should be observed in this file:
71 *
72 * <dl>
73 * <dt>t</dt>
74 * <dd>If the first argument to an operation is a type, it should be named t.</dd>
75 * <dt>s</dt>
76 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd>
77 * <dt>ts</dt>
78 * <dd>If an operations takes a list of types, the first should be named ts.</dd>
79 * <dt>ss</dt>
80 * <dd>A second list of types should be named ss.</dd>
81 * </dl>
82 *
83 * <p><b>This is NOT part of any supported API.
84 * If you write code that depends on this, you do so at your own risk.
85 * This code and its internal interfaces are subject to change or
86 * deletion without notice.</b>
87 */
88 public class Types {
89 protected static final Context.Key<Types> typesKey = new Context.Key<>();
90
91 final Symtab syms;
92 final JavacMessages messages;
93 final Names names;
94 final boolean allowPrimitiveClasses;
95 final Check chk;
96 final Enter enter;
97 JCDiagnostic.Factory diags;
98 List<Warner> warnStack = List.nil();
99 final Name capturedName;
100
101 public final Warner noWarnings;
102
103 // <editor-fold defaultstate="collapsed" desc="Instantiating">
104 public static Types instance(Context context) {
105 Types instance = context.get(typesKey);
106 if (instance == null)
107 instance = new Types(context);
108 return instance;
109 }
110
111 protected Types(Context context) {
112 context.put(typesKey, this);
113 syms = Symtab.instance(context);
114 names = Names.instance(context);
115 Source source = Source.instance(context);
116 chk = Check.instance(context);
117 enter = Enter.instance(context);
118 capturedName = names.fromString("<captured wildcard>");
119 messages = JavacMessages.instance(context);
120 diags = JCDiagnostic.Factory.instance(context);
121 noWarnings = new Warner(null);
122 Options options = Options.instance(context);
123 allowPrimitiveClasses = Feature.PRIMITIVE_CLASSES.allowedInSource(source) && options.isSet("enablePrimitiveClasses");
124 qualifiedSymbolCache = new HashMap<>();
125 }
126 // </editor-fold>
127
128 // <editor-fold defaultstate="collapsed" desc="bounds">
129 /**
130 * Get a wildcard's upper bound, returning non-wildcards unchanged.
131 * @param t a type argument, either a wildcard or a type
132 */
133 public Type wildUpperBound(Type t) {
134 if (t.hasTag(WILDCARD)) {
135 WildcardType w = (WildcardType) t;
136 if (w.isSuperBound())
137 return w.bound == null ? syms.objectType : w.bound.getUpperBound();
138 else
139 return wildUpperBound(w.type);
140 }
141 else return t;
142 }
143
144 /**
145 * Get a capture variable's upper bound, returning other types unchanged.
146 * @param t a type
147 */
148 public Type cvarUpperBound(Type t) {
149 if (t.hasTag(TYPEVAR)) {
150 TypeVar v = (TypeVar) t;
151 return v.isCaptured() ? cvarUpperBound(v.getUpperBound()) : v;
152 }
153 else return t;
154 }
155
156 /**
157 * Get a wildcard's lower bound, returning non-wildcards unchanged.
158 * @param t a type argument, either a wildcard or a type
159 */
160 public Type wildLowerBound(Type t) {
161 if (t.hasTag(WILDCARD)) {
162 WildcardType w = (WildcardType) t;
163 return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type);
164 }
165 else return t;
166 }
167
168 /**
169 * Get a capture variable's lower bound, returning other types unchanged.
170 * @param t a type
171 */
172 public Type cvarLowerBound(Type t) {
173 if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) {
174 return cvarLowerBound(t.getLowerBound());
175 }
176 else return t;
177 }
178
179 /**
180 * Recursively skip type-variables until a class/array type is found; capture conversion is then
181 * (optionally) applied to the resulting type. This is useful for i.e. computing a site that is
182 * suitable for a method lookup.
183 */
184 public Type skipTypeVars(Type site, boolean capture) {
185 while (site.hasTag(TYPEVAR)) {
186 site = site.getUpperBound();
187 }
188 return capture ? capture(site) : site;
189 }
190 // </editor-fold>
191
192 // <editor-fold defaultstate="collapsed" desc="projections">
193
194 /**
195 * A projection kind. See {@link TypeProjection}
196 */
197 enum ProjectionKind {
198 UPWARDS() {
199 @Override
200 ProjectionKind complement() {
201 return DOWNWARDS;
202 }
203 },
204 DOWNWARDS() {
205 @Override
206 ProjectionKind complement() {
207 return UPWARDS;
208 }
209 };
210
211 abstract ProjectionKind complement();
212 }
213
214 /**
215 * This visitor performs upwards and downwards projections on types.
216 *
217 * A projection is defined as a function that takes a type T, a set of type variables V and that
218 * produces another type S.
219 *
220 * An upwards projection maps a type T into a type S such that (i) T has no variables in V,
221 * and (ii) S is an upper bound of T.
222 *
223 * A downwards projection maps a type T into a type S such that (i) T has no variables in V,
224 * and (ii) S is a lower bound of T.
225 *
226 * Note that projections are only allowed to touch variables in V. Therefore, it is possible for
227 * a projection to leave its input type unchanged if it does not contain any variables in V.
228 *
229 * Moreover, note that while an upwards projection is always defined (every type as an upper bound),
230 * a downwards projection is not always defined.
231 *
232 * Examples:
233 *
234 * {@code upwards(List<#CAP1>, [#CAP1]) = List<? extends String>, where #CAP1 <: String }
235 * {@code downwards(List<#CAP2>, [#CAP2]) = List<? super String>, where #CAP2 :> String }
236 * {@code upwards(List<#CAP1>, [#CAP2]) = List<#CAP1> }
237 * {@code downwards(List<#CAP1>, [#CAP1]) = not defined }
238 */
239 class TypeProjection extends TypeMapping<ProjectionKind> {
240
241 List<Type> vars;
242 Set<Type> seen = new HashSet<>();
243
244 public TypeProjection(List<Type> vars) {
245 this.vars = vars;
246 }
247
248 @Override
249 public Type visitClassType(ClassType t, ProjectionKind pkind) {
250 if (t.isCompound()) {
251 List<Type> components = directSupertypes(t);
252 List<Type> components1 = components.map(c -> c.map(this, pkind));
253 if (components == components1) return t;
254 else return makeIntersectionType(components1);
255 } else {
256 Type outer = t.getEnclosingType();
257 Type outer1 = visit(outer, pkind);
258 List<Type> typarams = t.getTypeArguments();
259 List<Type> formals = t.tsym.type.getTypeArguments();
260 ListBuffer<Type> typarams1 = new ListBuffer<>();
261 boolean changed = false;
262 for (Type actual : typarams) {
263 Type t2 = mapTypeArgument(t, formals.head.getUpperBound(), actual, pkind);
264 if (t2.hasTag(BOT)) {
265 //not defined
266 return syms.botType;
267 }
268 typarams1.add(t2);
269 changed |= actual != t2;
270 formals = formals.tail;
271 }
272 if (outer1 == outer && !changed) return t;
273 else return new ClassType(outer1, typarams1.toList(), t.tsym, t.getMetadata(), t.getFlavor()) {
274 @Override
275 protected boolean needsStripping() {
276 return true;
277 }
278 };
279 }
280 }
281
282 @Override
283 public Type visitArrayType(ArrayType t, ProjectionKind s) {
284 Type elemtype = t.elemtype;
285 Type elemtype1 = visit(elemtype, s);
286 if (elemtype1 == elemtype) {
287 return t;
288 } else if (elemtype1.hasTag(BOT)) {
289 //undefined
290 return syms.botType;
291 } else {
292 return new ArrayType(elemtype1, t.tsym, t.metadata) {
293 @Override
294 protected boolean needsStripping() {
295 return true;
296 }
297 };
298 }
299 }
300
301 @Override
302 public Type visitTypeVar(TypeVar t, ProjectionKind pkind) {
303 if (vars.contains(t)) {
304 if (seen.add(t)) {
305 try {
306 final Type bound;
307 switch (pkind) {
308 case UPWARDS:
309 bound = t.getUpperBound();
310 break;
311 case DOWNWARDS:
312 bound = (t.getLowerBound() == null) ?
313 syms.botType :
314 t.getLowerBound();
315 break;
316 default:
317 Assert.error();
318 return null;
319 }
320 return bound.map(this, pkind);
321 } finally {
322 seen.remove(t);
323 }
324 } else {
325 //cycle
326 return pkind == ProjectionKind.UPWARDS ?
327 syms.objectType : syms.botType;
328 }
329 } else {
330 return t;
331 }
332 }
333
334 private Type mapTypeArgument(Type site, Type declaredBound, Type t, ProjectionKind pkind) {
335 return t.containsAny(vars) ?
336 t.map(new TypeArgumentProjection(site, declaredBound), pkind) :
337 t;
338 }
339
340 class TypeArgumentProjection extends TypeMapping<ProjectionKind> {
341
342 Type site;
343 Type declaredBound;
344
345 TypeArgumentProjection(Type site, Type declaredBound) {
346 this.site = site;
347 this.declaredBound = declaredBound;
348 }
349
350 @Override
351 public Type visitType(Type t, ProjectionKind pkind) {
352 //type argument is some type containing restricted vars
353 if (pkind == ProjectionKind.DOWNWARDS) {
354 //not defined
355 return syms.botType;
356 }
357 Type upper = t.map(TypeProjection.this, ProjectionKind.UPWARDS);
358 Type lower = t.map(TypeProjection.this, ProjectionKind.DOWNWARDS);
359 List<Type> formals = site.tsym.type.getTypeArguments();
360 BoundKind bk;
361 Type bound;
362 if (!isSameType(upper, syms.objectType) &&
363 (declaredBound.containsAny(formals) ||
364 !isSubtype(declaredBound, upper))) {
365 bound = upper;
366 bk = EXTENDS;
367 } else if (!lower.hasTag(BOT)) {
368 bound = lower;
369 bk = SUPER;
370 } else {
371 bound = syms.objectType;
372 bk = UNBOUND;
373 }
374 return makeWildcard(bound, bk);
375 }
376
377 @Override
378 public Type visitWildcardType(WildcardType wt, ProjectionKind pkind) {
379 //type argument is some wildcard whose bound contains restricted vars
380 Type bound = syms.botType;
381 BoundKind bk = wt.kind;
382 switch (wt.kind) {
383 case EXTENDS:
384 bound = wt.type.map(TypeProjection.this, pkind);
385 if (bound.hasTag(BOT)) {
386 return syms.botType;
387 }
388 break;
389 case SUPER:
390 bound = wt.type.map(TypeProjection.this, pkind.complement());
391 if (bound.hasTag(BOT)) {
392 bound = syms.objectType;
393 bk = UNBOUND;
394 }
395 break;
396 }
397 return makeWildcard(bound, bk);
398 }
399
400 private Type makeWildcard(Type bound, BoundKind bk) {
401 return new WildcardType(bound, bk, syms.boundClass) {
402 @Override
403 protected boolean needsStripping() {
404 return true;
405 }
406 };
407 }
408 }
409 }
410
411 /**
412 * Computes an upward projection of given type, and vars. See {@link TypeProjection}.
413 *
414 * @param t the type to be projected
415 * @param vars the set of type variables to be mapped
416 * @return the type obtained as result of the projection
417 */
418 public Type upward(Type t, List<Type> vars) {
419 return t.map(new TypeProjection(vars), ProjectionKind.UPWARDS);
420 }
421
422 /**
423 * Computes the set of captured variables mentioned in a given type. See {@link CaptureScanner}.
424 * This routine is typically used to computed the input set of variables to be used during
425 * an upwards projection (see {@link Types#upward(Type, List)}).
426 *
427 * @param t the type where occurrences of captured variables have to be found
428 * @return the set of captured variables found in t
429 */
430 public List<Type> captures(Type t) {
431 CaptureScanner cs = new CaptureScanner();
432 Set<Type> captures = new HashSet<>();
433 cs.visit(t, captures);
434 return List.from(captures);
435 }
436
437 /**
438 * This visitor scans a type recursively looking for occurrences of captured type variables.
439 */
440 class CaptureScanner extends SimpleVisitor<Void, Set<Type>> {
441
442 @Override
443 public Void visitType(Type t, Set<Type> types) {
444 return null;
445 }
446
447 @Override
448 public Void visitClassType(ClassType t, Set<Type> seen) {
449 if (t.isCompound()) {
450 directSupertypes(t).forEach(s -> visit(s, seen));
451 } else {
452 t.allparams().forEach(ta -> visit(ta, seen));
453 }
454 return null;
455 }
456
457 @Override
458 public Void visitArrayType(ArrayType t, Set<Type> seen) {
459 return visit(t.elemtype, seen);
460 }
461
462 @Override
463 public Void visitWildcardType(WildcardType t, Set<Type> seen) {
464 visit(t.type, seen);
465 return null;
466 }
467
468 @Override
469 public Void visitTypeVar(TypeVar t, Set<Type> seen) {
470 if ((t.tsym.flags() & Flags.SYNTHETIC) != 0 && seen.add(t)) {
471 visit(t.getUpperBound(), seen);
472 }
473 return null;
474 }
475
476 @Override
477 public Void visitCapturedType(CapturedType t, Set<Type> seen) {
478 if (seen.add(t)) {
479 visit(t.getUpperBound(), seen);
480 visit(t.getLowerBound(), seen);
481 }
482 return null;
483 }
484 }
485
486 // </editor-fold>
487
488 // <editor-fold defaultstate="collapsed" desc="isUnbounded">
489 /**
490 * Checks that all the arguments to a class are unbounded
491 * wildcards or something else that doesn't make any restrictions
492 * on the arguments. If a class isUnbounded, a raw super- or
493 * subclass can be cast to it without a warning.
494 * @param t a type
495 * @return true iff the given type is unbounded or raw
496 */
497 public boolean isUnbounded(Type t) {
498 return isUnbounded.visit(t);
499 }
500 // where
501 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() {
502
503 public Boolean visitType(Type t, Void ignored) {
504 return true;
505 }
506
507 @Override
508 public Boolean visitClassType(ClassType t, Void ignored) {
509 List<Type> parms = t.tsym.type.allparams();
510 List<Type> args = t.allparams();
511 while (parms.nonEmpty()) {
512 WildcardType unb = new WildcardType(syms.objectType,
513 BoundKind.UNBOUND,
514 syms.boundClass,
515 (TypeVar)parms.head);
516 if (!containsType(args.head, unb))
517 return false;
518 parms = parms.tail;
519 args = args.tail;
520 }
521 return true;
522 }
523 };
524 // </editor-fold>
525
526 // <editor-fold defaultstate="collapsed" desc="asSub">
527 /**
528 * Return the least specific subtype of t that starts with symbol
529 * sym. If none exists, return null. The least specific subtype
530 * is determined as follows:
531 *
532 * <p>If there is exactly one parameterized instance of sym that is a
533 * subtype of t, that parameterized instance is returned.<br>
534 * Otherwise, if the plain type or raw type `sym' is a subtype of
535 * type t, the type `sym' itself is returned. Otherwise, null is
536 * returned.
537 */
538 public Type asSub(Type t, Symbol sym) {
539 return asSub.visit(t, sym);
540 }
541 // where
542 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() {
543
544 public Type visitType(Type t, Symbol sym) {
545 return null;
546 }
547
548 @Override
549 public Type visitClassType(ClassType t, Symbol sym) {
550 if (t.tsym == sym)
551 return t;
552 Type base = asSuper(sym.type, t.tsym);
553 if (base == null)
554 return null;
555 ListBuffer<Type> from = new ListBuffer<>();
556 ListBuffer<Type> to = new ListBuffer<>();
557 try {
558 adapt(base, t, from, to);
559 } catch (AdaptFailure ex) {
560 return null;
561 }
562 Type res = subst(sym.type, from.toList(), to.toList());
563 if (!isSubtype(res, t))
564 return null;
565 ListBuffer<Type> openVars = new ListBuffer<>();
566 for (List<Type> l = sym.type.allparams();
567 l.nonEmpty(); l = l.tail)
568 if (res.contains(l.head) && !t.contains(l.head))
569 openVars.append(l.head);
570 if (openVars.nonEmpty()) {
571 if (t.isRaw()) {
572 // The subtype of a raw type is raw
573 res = erasure(res);
574 } else {
575 // Unbound type arguments default to ?
576 List<Type> opens = openVars.toList();
577 ListBuffer<Type> qs = new ListBuffer<>();
578 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) {
579 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND,
580 syms.boundClass, (TypeVar) iter.head));
581 }
582 res = subst(res, opens, qs.toList());
583 }
584 }
585 return res;
586 }
587
588 @Override
589 public Type visitErrorType(ErrorType t, Symbol sym) {
590 return t;
591 }
592 };
593 // </editor-fold>
594
595 // <editor-fold defaultstate="collapsed" desc="isConvertible">
596 /**
597 * Is t a subtype of or convertible via boxing/unboxing
598 * conversion to s?
599 */
600 public boolean isConvertible(Type t, Type s, Warner warn) {
601 if (t.hasTag(ERROR)) {
602 return true;
603 }
604
605 if (allowPrimitiveClasses) {
606 boolean tValue = t.isPrimitiveClass();
607 boolean sValue = s.isPrimitiveClass();
608 if (tValue != sValue) {
609 return tValue ?
610 isSubtype(t.referenceProjection(), s) :
611 !t.hasTag(BOT) && isSubtype(t, s.referenceProjection());
612 }
613 }
614
615 boolean tPrimitive = t.isPrimitive();
616 boolean sPrimitive = s.isPrimitive();
617 if (tPrimitive == sPrimitive) {
618 return isSubtypeUnchecked(t, s, warn);
619 }
620 boolean tUndet = t.hasTag(UNDETVAR);
621 boolean sUndet = s.hasTag(UNDETVAR);
622
623 if (tUndet || sUndet) {
624 return tUndet ?
625 isSubtype(t, boxedTypeOrType(s)) :
626 isSubtype(boxedTypeOrType(t), s);
627 }
628
629 return tPrimitive
630 ? isSubtype(boxedClass(t).type, s)
631 : isSubtype(unboxedType(t), s);
632 }
633
634 /**
635 * Is t a subtype of or convertible via boxing/unboxing
636 * conversions to s?
637 */
638 public boolean isConvertible(Type t, Type s) {
639 return isConvertible(t, s, noWarnings);
640 }
641 // </editor-fold>
642
643 // <editor-fold defaultstate="collapsed" desc="findSam">
644
645 /**
646 * Exception used to report a function descriptor lookup failure. The exception
647 * wraps a diagnostic that can be used to generate more details error
648 * messages.
649 */
650 public static class FunctionDescriptorLookupError extends RuntimeException {
651 private static final long serialVersionUID = 0;
652
653 transient JCDiagnostic diagnostic;
654
655 FunctionDescriptorLookupError() {
656 this.diagnostic = null;
657 }
658
659 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) {
660 this.diagnostic = diag;
661 return this;
662 }
663
664 public JCDiagnostic getDiagnostic() {
665 return diagnostic;
666 }
667
668 @Override
669 public Throwable fillInStackTrace() {
670 // This is an internal exception; the stack trace is irrelevant.
671 return this;
672 }
673 }
674
675 /**
676 * A cache that keeps track of function descriptors associated with given
677 * functional interfaces.
678 */
679 class DescriptorCache {
680
681 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>();
682
683 class FunctionDescriptor {
684 Symbol descSym;
685
686 FunctionDescriptor(Symbol descSym) {
687 this.descSym = descSym;
688 }
689
690 public Symbol getSymbol() {
691 return descSym;
692 }
693
694 public Type getType(Type site) {
695 site = removeWildcards(site);
696 if (site.isIntersection()) {
697 IntersectionClassType ict = (IntersectionClassType)site;
698 for (Type component : ict.getExplicitComponents()) {
699 if (!chk.checkValidGenericType(component)) {
700 //if the inferred functional interface type is not well-formed,
701 //or if it's not a subtype of the original target, issue an error
702 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site)));
703 }
704 }
705 } else {
706 if (!chk.checkValidGenericType(site)) {
707 //if the inferred functional interface type is not well-formed,
708 //or if it's not a subtype of the original target, issue an error
709 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site)));
710 }
711 }
712 return memberType(site, descSym);
713 }
714 }
715
716 class Entry {
717 final FunctionDescriptor cachedDescRes;
718 final int prevMark;
719
720 public Entry(FunctionDescriptor cachedDescRes,
721 int prevMark) {
722 this.cachedDescRes = cachedDescRes;
723 this.prevMark = prevMark;
724 }
725
726 boolean matches(int mark) {
727 return this.prevMark == mark;
728 }
729 }
730
731 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError {
732 Entry e = _map.get(origin);
733 CompoundScope members = membersClosure(origin.type, false);
734 if (e == null ||
735 !e.matches(members.getMark())) {
736 FunctionDescriptor descRes = findDescriptorInternal(origin, members);
737 _map.put(origin, new Entry(descRes, members.getMark()));
738 return descRes;
739 }
740 else {
741 return e.cachedDescRes;
742 }
743 }
744
745 /**
746 * Compute the function descriptor associated with a given functional interface
747 */
748 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin,
749 CompoundScope membersCache) throws FunctionDescriptorLookupError {
750 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0 || origin.isSealed()) {
751 //t must be an interface
752 throw failure("not.a.functional.intf", origin);
753 }
754
755 final ListBuffer<Symbol> abstracts = new ListBuffer<>();
756 for (Symbol sym : membersCache.getSymbols(new DescriptorFilter(origin))) {
757 Type mtype = memberType(origin.type, sym);
758 if (abstracts.isEmpty()) {
759 abstracts.append(sym);
760 } else if ((sym.name == abstracts.first().name &&
761 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) {
762 if (!abstracts.stream().filter(msym -> msym.owner.isSubClass(sym.enclClass(), Types.this))
763 .map(msym -> memberType(origin.type, msym))
764 .anyMatch(abstractMType -> isSubSignature(abstractMType, mtype))) {
765 abstracts.append(sym);
766 }
767 } else {
768 //the target method(s) should be the only abstract members of t
769 throw failure("not.a.functional.intf.1", origin,
770 diags.fragment(Fragments.IncompatibleAbstracts(Kinds.kindName(origin), origin)));
771 }
772 }
773 if (abstracts.isEmpty()) {
774 //t must define a suitable non-generic method
775 throw failure("not.a.functional.intf.1", origin,
776 diags.fragment(Fragments.NoAbstracts(Kinds.kindName(origin), origin)));
777 }
778 FunctionDescriptor descRes;
779 if (abstracts.size() == 1) {
780 descRes = new FunctionDescriptor(abstracts.first());
781 } else { // size > 1
782 descRes = mergeDescriptors(origin, abstracts.toList());
783 if (descRes == null) {
784 //we can get here if the functional interface is ill-formed
785 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>();
786 for (Symbol desc : abstracts) {
787 String key = desc.type.getThrownTypes().nonEmpty() ?
788 "descriptor.throws" : "descriptor";
789 descriptors.append(diags.fragment(key, desc.name,
790 desc.type.getParameterTypes(),
791 desc.type.getReturnType(),
792 desc.type.getThrownTypes()));
793 }
794 JCDiagnostic msg =
795 diags.fragment(Fragments.IncompatibleDescsInFunctionalIntf(Kinds.kindName(origin),
796 origin));
797 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors =
798 new JCDiagnostic.MultilineDiagnostic(msg, descriptors.toList());
799 throw failure(incompatibleDescriptors);
800 }
801 }
802 // an interface must be neither an identity interface nor a value interface to be functional.
803 List<Type> allInterfaces = closure(origin.type);
804 for (Type iface : allInterfaces) {
805 if (iface.isValueInterface()) {
806 throw failure("not.a.functional.intf.1", origin, diags.fragment(Fragments.ValueInterfaceNonfunctional));
807 }
808 if (iface.isIdentityInterface()) {
809 throw failure("not.a.functional.intf.1", origin, diags.fragment(Fragments.IdentityInterfaceNonfunctional));
810 }
811 }
812 return descRes;
813 }
814
815 /**
816 * Compute a synthetic type for the target descriptor given a list
817 * of override-equivalent methods in the functional interface type.
818 * The resulting method type is a method type that is override-equivalent
819 * and return-type substitutable with each method in the original list.
820 */
821 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) {
822 return mergeAbstracts(methodSyms, origin.type, false)
823 .map(bestSoFar -> new FunctionDescriptor(bestSoFar.baseSymbol()) {
824 @Override
825 public Type getType(Type origin) {
826 Type mt = memberType(origin, getSymbol());
827 return createMethodTypeWithThrown(mt, bestSoFar.type.getThrownTypes());
828 }
829 }).orElse(null);
830 }
831
832 FunctionDescriptorLookupError failure(String msg, Object... args) {
833 return failure(diags.fragment(msg, args));
834 }
835
836 FunctionDescriptorLookupError failure(JCDiagnostic diag) {
837 return new FunctionDescriptorLookupError().setMessage(diag);
838 }
839 }
840
841 private DescriptorCache descCache = new DescriptorCache();
842
843 /**
844 * Find the method descriptor associated to this class symbol - if the
845 * symbol 'origin' is not a functional interface, an exception is thrown.
846 */
847 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError {
848 return descCache.get(origin).getSymbol();
849 }
850
851 /**
852 * Find the type of the method descriptor associated to this class symbol -
853 * if the symbol 'origin' is not a functional interface, an exception is thrown.
854 */
855 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError {
856 return descCache.get(origin.tsym).getType(origin);
857 }
858
859 /**
860 * Is given type a functional interface?
861 */
862 public boolean isFunctionalInterface(TypeSymbol tsym) {
863 try {
864 findDescriptorSymbol(tsym);
865 return true;
866 } catch (FunctionDescriptorLookupError ex) {
867 return false;
868 }
869 }
870
871 public boolean isFunctionalInterface(Type site) {
872 try {
873 findDescriptorType(site);
874 return true;
875 } catch (FunctionDescriptorLookupError ex) {
876 return false;
877 }
878 }
879
880 public Type removeWildcards(Type site) {
881 if (site.getTypeArguments().stream().anyMatch(t -> t.hasTag(WILDCARD))) {
882 //compute non-wildcard parameterization - JLS 9.9
883 List<Type> actuals = site.getTypeArguments();
884 List<Type> formals = site.tsym.type.getTypeArguments();
885 ListBuffer<Type> targs = new ListBuffer<>();
886 for (Type formal : formals) {
887 Type actual = actuals.head;
888 Type bound = formal.getUpperBound();
889 if (actuals.head.hasTag(WILDCARD)) {
890 WildcardType wt = (WildcardType)actual;
891 //check that bound does not contain other formals
892 if (bound.containsAny(formals)) {
893 targs.add(wt.type);
894 } else {
895 //compute new type-argument based on declared bound and wildcard bound
896 switch (wt.kind) {
897 case UNBOUND:
898 targs.add(bound);
899 break;
900 case EXTENDS:
901 targs.add(glb(bound, wt.type));
902 break;
903 case SUPER:
904 targs.add(wt.type);
905 break;
906 default:
907 Assert.error("Cannot get here!");
908 }
909 }
910 } else {
911 //not a wildcard - the new type argument remains unchanged
912 targs.add(actual);
913 }
914 actuals = actuals.tail;
915 }
916 return subst(site.tsym.type, formals, targs.toList());
917 } else {
918 return site;
919 }
920 }
921
922 /**
923 * Create a symbol for a class that implements a given functional interface
924 * and overrides its functional descriptor. This routine is used for two
925 * main purposes: (i) checking well-formedness of a functional interface;
926 * (ii) perform functional interface bridge calculation.
927 */
928 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, Type target, long cflags) {
929 if (target == null || target == syms.unknownType) {
930 return null;
931 }
932 Symbol descSym = findDescriptorSymbol(target.tsym);
933 Type descType = findDescriptorType(target);
934 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass());
935 csym.completer = Completer.NULL_COMPLETER;
936 csym.members_field = WriteableScope.create(csym);
937 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym);
938 csym.members_field.enter(instDescSym);
939 Type.ClassType ctype = new Type.ClassType(Type.noType, List.nil(), csym);
940 ctype.supertype_field = syms.objectType;
941 ctype.interfaces_field = target.isIntersection() ?
942 directSupertypes(target) :
943 List.of(target);
944 csym.type = ctype;
945 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile;
946 return csym;
947 }
948
949 /**
950 * Find the minimal set of methods that are overridden by the functional
951 * descriptor in 'origin'. All returned methods are assumed to have different
952 * erased signatures.
953 */
954 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) {
955 Assert.check(isFunctionalInterface(origin));
956 Symbol descSym = findDescriptorSymbol(origin);
957 CompoundScope members = membersClosure(origin.type, false);
958 ListBuffer<Symbol> overridden = new ListBuffer<>();
959 outer: for (Symbol m2 : members.getSymbolsByName(descSym.name, bridgeFilter)) {
960 if (m2 == descSym) continue;
961 else if (descSym.overrides(m2, origin, Types.this, false)) {
962 for (Symbol m3 : overridden) {
963 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) ||
964 (m3.overrides(m2, origin, Types.this, false) &&
965 (pendingBridges((ClassSymbol)origin, m3.enclClass()) ||
966 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) {
967 continue outer;
968 }
969 }
970 overridden.add(m2);
971 }
972 }
973 return overridden.toList();
974 }
975 //where
976 // Use anonymous class instead of lambda expression intentionally,
977 // because the variable `names` has modifier: final.
978 private Predicate<Symbol> bridgeFilter = new Predicate<Symbol>() {
979 public boolean test(Symbol t) {
980 return t.kind == MTH &&
981 !names.isInitOrVNew(t.name) &&
982 t.name != names.clinit &&
983 (t.flags() & SYNTHETIC) == 0;
984 }
985 };
986
987 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) {
988 //a symbol will be completed from a classfile if (a) symbol has
989 //an associated file object with CLASS kind and (b) the symbol has
990 //not been entered
991 if (origin.classfile != null &&
992 origin.classfile.getKind() == JavaFileObject.Kind.CLASS &&
993 enter.getEnv(origin) == null) {
994 return false;
995 }
996 if (origin == s) {
997 return true;
998 }
999 for (Type t : interfaces(origin.type)) {
1000 if (pendingBridges((ClassSymbol)t.tsym, s)) {
1001 return true;
1002 }
1003 }
1004 return false;
1005 }
1006 // </editor-fold>
1007
1008 /**
1009 * Scope filter used to skip methods that should be ignored (such as methods
1010 * overridden by j.l.Object) during function interface conversion interface check
1011 */
1012 class DescriptorFilter implements Predicate<Symbol> {
1013
1014 TypeSymbol origin;
1015
1016 DescriptorFilter(TypeSymbol origin) {
1017 this.origin = origin;
1018 }
1019
1020 @Override
1021 public boolean test(Symbol sym) {
1022 return sym.kind == MTH &&
1023 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT &&
1024 !overridesObjectMethod(origin, sym) &&
1025 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0;
1026 }
1027 }
1028
1029 // <editor-fold defaultstate="collapsed" desc="isSubtype">
1030 /**
1031 * Is t an unchecked subtype of s?
1032 */
1033 public boolean isSubtypeUnchecked(Type t, Type s) {
1034 return isSubtypeUnchecked(t, s, noWarnings);
1035 }
1036 /**
1037 * Is t an unchecked subtype of s?
1038 */
1039 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) {
1040 boolean result = isSubtypeUncheckedInternal(t, s, true, warn);
1041 if (result) {
1042 checkUnsafeVarargsConversion(t, s, warn);
1043 }
1044 return result;
1045 }
1046 //where
1047 private boolean isSubtypeUncheckedInternal(Type t, Type s, boolean capture, Warner warn) {
1048 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) {
1049 if (((ArrayType)t).elemtype.isPrimitive()) {
1050 return isSameType(elemtype(t), elemtype(s));
1051 } else {
1052 // if T.ref <: S, then T[] <: S[]
1053 Type es = elemtype(s);
1054 Type et = elemtype(t);
1055 if (allowPrimitiveClasses) {
1056 if (et.isPrimitiveClass()) {
1057 et = et.referenceProjection();
1058 if (es.isPrimitiveClass())
1059 es = es.referenceProjection(); // V <: V, surely
1060 }
1061 }
1062 if (!isSubtypeUncheckedInternal(et, es, false, warn))
1063 return false;
1064 return true;
1065 }
1066 } else if (isSubtype(t, s, capture)) {
1067 return true;
1068 } else if (t.hasTag(TYPEVAR)) {
1069 return isSubtypeUncheckedInternal(t.getUpperBound(), s, false, warn);
1070 } else if (!s.isRaw()) {
1071 Type t2 = asSuper(t, s.tsym);
1072 if (t2 != null && t2.isRaw()) {
1073 if (isReifiable(s)) {
1074 warn.silentWarn(LintCategory.UNCHECKED);
1075 } else {
1076 warn.warn(LintCategory.UNCHECKED);
1077 }
1078 return true;
1079 }
1080 }
1081 return false;
1082 }
1083
1084 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) {
1085 if (!t.hasTag(ARRAY) || isReifiable(t)) {
1086 return;
1087 }
1088 ArrayType from = (ArrayType)t;
1089 boolean shouldWarn = false;
1090 switch (s.getTag()) {
1091 case ARRAY:
1092 ArrayType to = (ArrayType)s;
1093 shouldWarn = from.isVarargs() &&
1094 !to.isVarargs() &&
1095 !isReifiable(from);
1096 break;
1097 case CLASS:
1098 shouldWarn = from.isVarargs();
1099 break;
1100 }
1101 if (shouldWarn) {
1102 warn.warn(LintCategory.VARARGS);
1103 }
1104 }
1105
1106 /**
1107 * Is t a subtype of s?<br>
1108 * (not defined for Method and ForAll types)
1109 */
1110 public final boolean isSubtype(Type t, Type s) {
1111 return isSubtype(t, s, true);
1112 }
1113 public final boolean isSubtypeNoCapture(Type t, Type s) {
1114 return isSubtype(t, s, false);
1115 }
1116 public boolean isSubtype(Type t, Type s, boolean capture) {
1117 if (t.equalsIgnoreMetadata(s))
1118 return true;
1119 if (s.isPartial())
1120 return isSuperType(s, t);
1121
1122 if (s.isCompound()) {
1123 for (Type s2 : interfaces(s).prepend(supertype(s))) {
1124 if (!isSubtype(t, s2, capture))
1125 return false;
1126 }
1127 return true;
1128 }
1129
1130 // Generally, if 's' is a lower-bounded type variable, recur on lower bound; but
1131 // for inference variables and intersections, we need to keep 's'
1132 // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars)
1133 if (!t.hasTag(UNDETVAR) && !t.isCompound()) {
1134 // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s
1135 Type lower = cvarLowerBound(wildLowerBound(s));
1136 if (s != lower && !lower.hasTag(BOT))
1137 return isSubtype(capture ? capture(t) : t, lower, false);
1138 }
1139
1140 return isSubtype.visit(capture ? capture(t) : t, s);
1141 }
1142 // where
1143 private TypeRelation isSubtype = new TypeRelation()
1144 {
1145 @Override
1146 public Boolean visitType(Type t, Type s) {
1147 switch (t.getTag()) {
1148 case BYTE:
1149 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag()));
1150 case CHAR:
1151 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag()));
1152 case SHORT: case INT: case LONG:
1153 case FLOAT: case DOUBLE:
1154 return t.getTag().isSubRangeOf(s.getTag());
1155 case BOOLEAN: case VOID:
1156 return t.hasTag(s.getTag());
1157 case TYPEVAR:
1158 return isSubtypeNoCapture(t.getUpperBound(), s);
1159 case BOT:
1160 return
1161 s.hasTag(BOT) || (s.hasTag(CLASS) && (!allowPrimitiveClasses || !s.isPrimitiveClass())) ||
1162 s.hasTag(ARRAY) || s.hasTag(TYPEVAR);
1163 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495)
1164 case NONE:
1165 return false;
1166 default:
1167 throw new AssertionError("isSubtype " + t.getTag());
1168 }
1169 }
1170
1171 private Set<TypePair> cache = new HashSet<>();
1172
1173 private boolean containsTypeRecursive(Type t, Type s) {
1174 TypePair pair = new TypePair(t, s);
1175 if (cache.add(pair)) {
1176 try {
1177 return containsType(t.getTypeArguments(),
1178 s.getTypeArguments());
1179 } finally {
1180 cache.remove(pair);
1181 }
1182 } else {
1183 return containsType(t.getTypeArguments(),
1184 rewriteSupers(s).getTypeArguments());
1185 }
1186 }
1187
1188 private Type rewriteSupers(Type t) {
1189 if (!t.isParameterized())
1190 return t;
1191 ListBuffer<Type> from = new ListBuffer<>();
1192 ListBuffer<Type> to = new ListBuffer<>();
1193 adaptSelf(t, from, to);
1194 if (from.isEmpty())
1195 return t;
1196 ListBuffer<Type> rewrite = new ListBuffer<>();
1197 boolean changed = false;
1198 for (Type orig : to.toList()) {
1199 Type s = rewriteSupers(orig);
1200 if (s.isSuperBound() && !s.isExtendsBound()) {
1201 s = new WildcardType(syms.objectType,
1202 BoundKind.UNBOUND,
1203 syms.boundClass,
1204 s.getMetadata());
1205 changed = true;
1206 } else if (s != orig) {
1207 s = new WildcardType(wildUpperBound(s),
1208 BoundKind.EXTENDS,
1209 syms.boundClass,
1210 s.getMetadata());
1211 changed = true;
1212 }
1213 rewrite.append(s);
1214 }
1215 if (changed)
1216 return subst(t.tsym.type, from.toList(), rewrite.toList());
1217 else
1218 return t;
1219 }
1220
1221 @Override
1222 public Boolean visitClassType(ClassType t, Type s) {
1223 Type sup = asSuper(t, s.tsym);
1224 if (sup == null) return false;
1225 // If t is an intersection, sup might not be a class type
1226 if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s);
1227 return sup.tsym == s.tsym
1228 && (t.tsym != s.tsym || t.isReferenceProjection() == s.isReferenceProjection())
1229 // Check type variable containment
1230 && (!s.isParameterized() || containsTypeRecursive(s, sup))
1231 && isSubtypeNoCapture(sup.getEnclosingType(),
1232 s.getEnclosingType());
1233 }
1234
1235 @Override
1236 public Boolean visitArrayType(ArrayType t, Type s) {
1237 if (s.hasTag(ARRAY)) {
1238 if (t.elemtype.isPrimitive())
1239 return isSameType(t.elemtype, elemtype(s));
1240 else {
1241 // if T.ref <: S, then T[] <: S[]
1242 Type es = elemtype(s);
1243 Type et = elemtype(t);
1244 if (allowPrimitiveClasses && et.isPrimitiveClass()) {
1245 et = et.referenceProjection();
1246 if (es.isPrimitiveClass())
1247 es = es.referenceProjection(); // V <: V, surely
1248 }
1249 return isSubtypeNoCapture(et, es);
1250 }
1251 }
1252
1253 if (s.hasTag(CLASS)) {
1254 Name sname = s.tsym.getQualifiedName();
1255 return sname == names.java_lang_Object
1256 || sname == names.java_lang_Cloneable
1257 || sname == names.java_io_Serializable;
1258 }
1259
1260 return false;
1261 }
1262
1263 @Override
1264 public Boolean visitUndetVar(UndetVar t, Type s) {
1265 //todo: test against origin needed? or replace with substitution?
1266 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1267 return true;
1268 } else if (s.hasTag(BOT)) {
1269 //if 's' is 'null' there's no instantiated type U for which
1270 //U <: s (but 'null' itself, which is not a valid type)
1271 return false;
1272 }
1273
1274 t.addBound(InferenceBound.UPPER, s, Types.this);
1275 return true;
1276 }
1277
1278 @Override
1279 public Boolean visitErrorType(ErrorType t, Type s) {
1280 return true;
1281 }
1282 };
1283
1284 /**
1285 * Is t a subtype of every type in given list `ts'?<br>
1286 * (not defined for Method and ForAll types)<br>
1287 * Allows unchecked conversions.
1288 */
1289 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) {
1290 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1291 if (!isSubtypeUnchecked(t, l.head, warn))
1292 return false;
1293 return true;
1294 }
1295
1296 /**
1297 * Are corresponding elements of ts subtypes of ss? If lists are
1298 * of different length, return false.
1299 */
1300 public boolean isSubtypes(List<Type> ts, List<Type> ss) {
1301 while (ts.tail != null && ss.tail != null
1302 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1303 isSubtype(ts.head, ss.head)) {
1304 ts = ts.tail;
1305 ss = ss.tail;
1306 }
1307 return ts.tail == null && ss.tail == null;
1308 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1309 }
1310
1311 /**
1312 * Are corresponding elements of ts subtypes of ss, allowing
1313 * unchecked conversions? If lists are of different length,
1314 * return false.
1315 **/
1316 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) {
1317 while (ts.tail != null && ss.tail != null
1318 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1319 isSubtypeUnchecked(ts.head, ss.head, warn)) {
1320 ts = ts.tail;
1321 ss = ss.tail;
1322 }
1323 return ts.tail == null && ss.tail == null;
1324 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1325 }
1326 // </editor-fold>
1327
1328 // <editor-fold defaultstate="collapsed" desc="isSuperType">
1329 /**
1330 * Is t a supertype of s?
1331 */
1332 public boolean isSuperType(Type t, Type s) {
1333 switch (t.getTag()) {
1334 case ERROR:
1335 return true;
1336 case UNDETVAR: {
1337 UndetVar undet = (UndetVar)t;
1338 if (t == s ||
1339 undet.qtype == s ||
1340 s.hasTag(ERROR) ||
1341 s.hasTag(BOT)) {
1342 return true;
1343 }
1344 undet.addBound(InferenceBound.LOWER, s, this);
1345 return true;
1346 }
1347 default:
1348 return isSubtype(s, t);
1349 }
1350 }
1351 // </editor-fold>
1352
1353 // <editor-fold defaultstate="collapsed" desc="isSameType">
1354 /**
1355 * Are corresponding elements of the lists the same type? If
1356 * lists are of different length, return false.
1357 */
1358 public boolean isSameTypes(List<Type> ts, List<Type> ss) {
1359 while (ts.tail != null && ss.tail != null
1360 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1361 isSameType(ts.head, ss.head)) {
1362 ts = ts.tail;
1363 ss = ss.tail;
1364 }
1365 return ts.tail == null && ss.tail == null;
1366 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1367 }
1368
1369 /**
1370 * A polymorphic signature method (JLS 15.12.3) is a method that
1371 * (i) is declared in the java.lang.invoke.MethodHandle/VarHandle classes;
1372 * (ii) takes a single variable arity parameter;
1373 * (iii) whose declared type is Object[];
1374 * (iv) has any return type, Object signifying a polymorphic return type; and
1375 * (v) is native.
1376 */
1377 public boolean isSignaturePolymorphic(MethodSymbol msym) {
1378 List<Type> argtypes = msym.type.getParameterTypes();
1379 return (msym.flags_field & NATIVE) != 0 &&
1380 (msym.owner == syms.methodHandleType.tsym || msym.owner == syms.varHandleType.tsym) &&
1381 argtypes.length() == 1 &&
1382 argtypes.head.hasTag(TypeTag.ARRAY) &&
1383 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym;
1384 }
1385
1386 /**
1387 * Is t the same type as s?
1388 */
1389 public boolean isSameType(Type t, Type s) {
1390 return isSameTypeVisitor.visit(t, s);
1391 }
1392 // where
1393
1394 /**
1395 * Type-equality relation - type variables are considered
1396 * equals if they share the same object identity.
1397 */
1398 TypeRelation isSameTypeVisitor = new TypeRelation() {
1399
1400 public Boolean visitType(Type t, Type s) {
1401 if (t.equalsIgnoreMetadata(s))
1402 return true;
1403
1404 if (s.isPartial())
1405 return visit(s, t);
1406
1407 switch (t.getTag()) {
1408 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1409 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE:
1410 return t.hasTag(s.getTag());
1411 case TYPEVAR: {
1412 if (s.hasTag(TYPEVAR)) {
1413 //type-substitution does not preserve type-var types
1414 //check that type var symbols and bounds are indeed the same
1415 return t == s;
1416 }
1417 else {
1418 //special case for s == ? super X, where upper(s) = u
1419 //check that u == t, where u has been set by Type.withTypeVar
1420 return s.isSuperBound() &&
1421 !s.isExtendsBound() &&
1422 visit(t, wildUpperBound(s));
1423 }
1424 }
1425 default:
1426 throw new AssertionError("isSameType " + t.getTag());
1427 }
1428 }
1429
1430 @Override
1431 public Boolean visitWildcardType(WildcardType t, Type s) {
1432 if (!s.hasTag(WILDCARD)) {
1433 return false;
1434 } else {
1435 WildcardType t2 = (WildcardType)s;
1436 return (t.kind == t2.kind || (t.isExtendsBound() && s.isExtendsBound())) &&
1437 isSameType(t.type, t2.type);
1438 }
1439 }
1440
1441 @Override
1442 public Boolean visitClassType(ClassType t, Type s) {
1443 if (t == s)
1444 return true;
1445
1446 if (s.isPartial())
1447 return visit(s, t);
1448
1449 if (s.isSuperBound() && !s.isExtendsBound())
1450 return visit(t, wildUpperBound(s)) && visit(t, wildLowerBound(s));
1451
1452 if (t.isCompound() && s.isCompound()) {
1453 if (!visit(supertype(t), supertype(s)))
1454 return false;
1455
1456 Map<Symbol,Type> tMap = new HashMap<>();
1457 for (Type ti : interfaces(t)) {
1458 if (tMap.containsKey(ti)) {
1459 throw new AssertionError("Malformed intersection");
1460 }
1461 tMap.put(ti.tsym, ti);
1462 }
1463 for (Type si : interfaces(s)) {
1464 if (!tMap.containsKey(si.tsym))
1465 return false;
1466 Type ti = tMap.remove(si.tsym);
1467 if (!visit(ti, si))
1468 return false;
1469 }
1470 return tMap.isEmpty();
1471 }
1472 return t.tsym == s.tsym
1473 && t.isReferenceProjection() == s.isReferenceProjection()
1474 && visit(getEnclosingType(t), getEnclosingType(s))
1475 && containsTypeEquivalent(t.getTypeArguments(), s.getTypeArguments());
1476 }
1477 // where
1478 private Type getEnclosingType(Type t) {
1479 Type et = t.getEnclosingType();
1480 if (et.isReferenceProjection()) {
1481 et = et.valueProjection();
1482 }
1483 return et;
1484 }
1485
1486 @Override
1487 public Boolean visitArrayType(ArrayType t, Type s) {
1488 if (t == s)
1489 return true;
1490
1491 if (s.isPartial())
1492 return visit(s, t);
1493
1494 return s.hasTag(ARRAY)
1495 && containsTypeEquivalent(t.elemtype, elemtype(s));
1496 }
1497
1498 @Override
1499 public Boolean visitMethodType(MethodType t, Type s) {
1500 // isSameType for methods does not take thrown
1501 // exceptions into account!
1502 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType());
1503 }
1504
1505 @Override
1506 public Boolean visitPackageType(PackageType t, Type s) {
1507 return t == s;
1508 }
1509
1510 @Override
1511 public Boolean visitForAll(ForAll t, Type s) {
1512 if (!s.hasTag(FORALL)) {
1513 return false;
1514 }
1515
1516 ForAll forAll = (ForAll)s;
1517 return hasSameBounds(t, forAll)
1518 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
1519 }
1520
1521 @Override
1522 public Boolean visitUndetVar(UndetVar t, Type s) {
1523 if (s.hasTag(WILDCARD)) {
1524 // FIXME, this might be leftovers from before capture conversion
1525 return false;
1526 }
1527
1528 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1529 return true;
1530 }
1531
1532 t.addBound(InferenceBound.EQ, s, Types.this);
1533
1534 return true;
1535 }
1536
1537 @Override
1538 public Boolean visitErrorType(ErrorType t, Type s) {
1539 return true;
1540 }
1541 };
1542
1543 // </editor-fold>
1544
1545 // <editor-fold defaultstate="collapsed" desc="Contains Type">
1546 public boolean containedBy(Type t, Type s) {
1547 switch (t.getTag()) {
1548 case UNDETVAR:
1549 if (s.hasTag(WILDCARD)) {
1550 UndetVar undetvar = (UndetVar)t;
1551 WildcardType wt = (WildcardType)s;
1552 switch(wt.kind) {
1553 case UNBOUND:
1554 break;
1555 case EXTENDS: {
1556 Type bound = wildUpperBound(s);
1557 undetvar.addBound(InferenceBound.UPPER, bound, this);
1558 break;
1559 }
1560 case SUPER: {
1561 Type bound = wildLowerBound(s);
1562 undetvar.addBound(InferenceBound.LOWER, bound, this);
1563 break;
1564 }
1565 }
1566 return true;
1567 } else {
1568 return isSameType(t, s);
1569 }
1570 case ERROR:
1571 return true;
1572 default:
1573 return containsType(s, t);
1574 }
1575 }
1576
1577 boolean containsType(List<Type> ts, List<Type> ss) {
1578 while (ts.nonEmpty() && ss.nonEmpty()
1579 && containsType(ts.head, ss.head)) {
1580 ts = ts.tail;
1581 ss = ss.tail;
1582 }
1583 return ts.isEmpty() && ss.isEmpty();
1584 }
1585
1586 /**
1587 * Check if t contains s.
1588 *
1589 * <p>T contains S if:
1590 *
1591 * <p>{@code L(T) <: L(S) && U(S) <: U(T)}
1592 *
1593 * <p>This relation is only used by ClassType.isSubtype(), that
1594 * is,
1595 *
1596 * <p>{@code C<S> <: C<T> if T contains S.}
1597 *
1598 * <p>Because of F-bounds, this relation can lead to infinite
1599 * recursion. Thus we must somehow break that recursion. Notice
1600 * that containsType() is only called from ClassType.isSubtype().
1601 * Since the arguments have already been checked against their
1602 * bounds, we know:
1603 *
1604 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)}
1605 *
1606 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)}
1607 *
1608 * @param t a type
1609 * @param s a type
1610 */
1611 public boolean containsType(Type t, Type s) {
1612 return containsType.visit(t, s);
1613 }
1614 // where
1615 private TypeRelation containsType = new TypeRelation() {
1616
1617 public Boolean visitType(Type t, Type s) {
1618 if (s.isPartial())
1619 return containedBy(s, t);
1620 else
1621 return isSameType(t, s);
1622 }
1623
1624 // void debugContainsType(WildcardType t, Type s) {
1625 // System.err.println();
1626 // System.err.format(" does %s contain %s?%n", t, s);
1627 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n",
1628 // wildUpperBound(s), s, t, wildUpperBound(t),
1629 // t.isSuperBound()
1630 // || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t)));
1631 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n",
1632 // wildLowerBound(t), t, s, wildLowerBound(s),
1633 // t.isExtendsBound()
1634 // || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s)));
1635 // System.err.println();
1636 // }
1637
1638 @Override
1639 public Boolean visitWildcardType(WildcardType t, Type s) {
1640 if (s.isPartial())
1641 return containedBy(s, t);
1642 else {
1643 // debugContainsType(t, s);
1644
1645 // ----------------------------------- Unspecified behavior ----------------
1646
1647 /* If a primitive class V implements an interface I, then does "? extends I" contain V?
1648 It seems widening must be applied here to answer yes to compile some common code
1649 patterns.
1650 */
1651
1652 // ---------------------------------------------------------------------------
1653 return isSameWildcard(t, s)
1654 || isCaptureOf(s, t)
1655 || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) &&
1656 (t.isSuperBound() || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t))));
1657 }
1658 }
1659
1660 @Override
1661 public Boolean visitUndetVar(UndetVar t, Type s) {
1662 if (!s.hasTag(WILDCARD)) {
1663 return isSameType(t, s);
1664 } else {
1665 return false;
1666 }
1667 }
1668
1669 @Override
1670 public Boolean visitErrorType(ErrorType t, Type s) {
1671 return true;
1672 }
1673 };
1674
1675 public boolean isCaptureOf(Type s, WildcardType t) {
1676 if (!s.hasTag(TYPEVAR) || !((TypeVar)s).isCaptured())
1677 return false;
1678 return isSameWildcard(t, ((CapturedType)s).wildcard);
1679 }
1680
1681 public boolean isSameWildcard(WildcardType t, Type s) {
1682 if (!s.hasTag(WILDCARD))
1683 return false;
1684 WildcardType w = (WildcardType)s;
1685 return w.kind == t.kind && w.type == t.type;
1686 }
1687
1688 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) {
1689 while (ts.nonEmpty() && ss.nonEmpty()
1690 && containsTypeEquivalent(ts.head, ss.head)) {
1691 ts = ts.tail;
1692 ss = ss.tail;
1693 }
1694 return ts.isEmpty() && ss.isEmpty();
1695 }
1696 // </editor-fold>
1697
1698 // <editor-fold defaultstate="collapsed" desc="isCastable">
1699 public boolean isCastable(Type t, Type s) {
1700 return isCastable(t, s, noWarnings);
1701 }
1702
1703 /**
1704 * Is t castable to s?<br>
1705 * s is assumed to be an erased type.<br>
1706 * (not defined for Method and ForAll types).
1707 */
1708 public boolean isCastable(Type t, Type s, Warner warn) {
1709 // if same type
1710 if (t == s)
1711 return true;
1712 // if one of the types is primitive
1713 if (t.isPrimitive() != s.isPrimitive()) {
1714 t = skipTypeVars(t, false);
1715 return (isConvertible(t, s, warn)
1716 || (s.isPrimitive() &&
1717 isSubtype(boxedClass(s).type, t)));
1718 }
1719 boolean result;
1720 if (warn != warnStack.head) {
1721 try {
1722 warnStack = warnStack.prepend(warn);
1723 checkUnsafeVarargsConversion(t, s, warn);
1724 result = isCastable.visit(t,s);
1725 } finally {
1726 warnStack = warnStack.tail;
1727 }
1728 } else {
1729 result = isCastable.visit(t,s);
1730 }
1731 if (result && t.hasTag(CLASS) && t.tsym.kind.matches(Kinds.KindSelector.TYP)
1732 && s.hasTag(CLASS) && s.tsym.kind.matches(Kinds.KindSelector.TYP)
1733 && (t.tsym.isSealed() || s.tsym.isSealed())) {
1734 return (t.isCompound() || s.isCompound()) ?
1735 true :
1736 !areDisjoint((ClassSymbol)t.tsym, (ClassSymbol)s.tsym);
1737 }
1738 return result;
1739 }
1740 // where
1741 private boolean areDisjoint(ClassSymbol ts, ClassSymbol ss) {
1742 if (isSubtype(erasure(ts.type.referenceProjectionOrSelf()), erasure(ss.type))) {
1743 return false;
1744 }
1745 // if both are classes or both are interfaces, shortcut
1746 if (ts.isInterface() == ss.isInterface() && isSubtype(erasure(ss.type), erasure(ts.type))) {
1747 return false;
1748 }
1749 if (ts.isInterface() && !ss.isInterface()) {
1750 /* so ts is interface but ss is a class
1751 * an interface is disjoint from a class if the class is disjoint form the interface
1752 */
1753 return areDisjoint(ss, ts);
1754 }
1755 // a final class that is not subtype of ss is disjoint
1756 if (!ts.isInterface() && ts.isFinal()) {
1757 return true;
1758 }
1759 // if at least one is sealed
1760 if (ts.isSealed() || ss.isSealed()) {
1761 // permitted subtypes have to be disjoint with the other symbol
1762 ClassSymbol sealedOne = ts.isSealed() ? ts : ss;
1763 ClassSymbol other = sealedOne == ts ? ss : ts;
1764 return sealedOne.permitted.stream().allMatch(sym -> areDisjoint((ClassSymbol)sym, other));
1765 }
1766 return false;
1767 }
1768
1769 private TypeRelation isCastable = new TypeRelation() {
1770
1771 public Boolean visitType(Type t, Type s) {
1772 if (s.hasTag(ERROR) || t.hasTag(NONE))
1773 return true;
1774
1775 switch (t.getTag()) {
1776 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1777 case DOUBLE:
1778 return s.isNumeric();
1779 case BOOLEAN:
1780 return s.hasTag(BOOLEAN);
1781 case VOID:
1782 return false;
1783 case BOT:
1784 return isSubtype(t, s);
1785 default:
1786 throw new AssertionError();
1787 }
1788 }
1789
1790 @Override
1791 public Boolean visitWildcardType(WildcardType t, Type s) {
1792 return isCastable(wildUpperBound(t), s, warnStack.head);
1793 }
1794
1795 @Override
1796 public Boolean visitClassType(ClassType t, Type s) {
1797 if (s.hasTag(ERROR) || (s.hasTag(BOT) && (!allowPrimitiveClasses || !t.isPrimitiveClass())))
1798 return true;
1799
1800 if (s.hasTag(TYPEVAR)) {
1801 if (isCastable(t, s.getUpperBound(), noWarnings)) {
1802 warnStack.head.warn(LintCategory.UNCHECKED);
1803 return true;
1804 } else {
1805 return false;
1806 }
1807 }
1808
1809 if (t.isCompound() || s.isCompound()) {
1810 return !t.isCompound() ?
1811 visitCompoundType((ClassType)s, t, true) :
1812 visitCompoundType(t, s, false);
1813 }
1814
1815 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) {
1816 if (allowPrimitiveClasses) {
1817 if (t.isPrimitiveClass()) {
1818 // (s) Value ? == (s) Value.ref
1819 t = t.referenceProjection();
1820 }
1821 if (s.isPrimitiveClass()) {
1822 // (Value) t ? == (Value.ref) t
1823 s = s.referenceProjection();
1824 }
1825 }
1826 boolean upcast;
1827 if ((upcast = isSubtype(erasure(t), erasure(s)))
1828 || isSubtype(erasure(s), erasure(t))) {
1829 if (!upcast && s.hasTag(ARRAY)) {
1830 if (!isReifiable(s))
1831 warnStack.head.warn(LintCategory.UNCHECKED);
1832 return true;
1833 } else if (s.isRaw()) {
1834 return true;
1835 } else if (t.isRaw()) {
1836 if (!isUnbounded(s))
1837 warnStack.head.warn(LintCategory.UNCHECKED);
1838 return true;
1839 }
1840 // Assume |a| <: |b|
1841 final Type a = upcast ? t : s;
1842 final Type b = upcast ? s : t;
1843 final boolean HIGH = true;
1844 final boolean LOW = false;
1845 final boolean DONT_REWRITE_TYPEVARS = false;
1846 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS);
1847 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS);
1848 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS);
1849 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS);
1850 Type lowSub = asSub(bLow, aLow.tsym);
1851 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1852 if (highSub == null) {
1853 final boolean REWRITE_TYPEVARS = true;
1854 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS);
1855 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS);
1856 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS);
1857 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS);
1858 lowSub = asSub(bLow, aLow.tsym);
1859 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1860 }
1861 if (highSub != null) {
1862 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) {
1863 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym);
1864 }
1865 if (!disjointTypes(aHigh.allparams(), highSub.allparams())
1866 && !disjointTypes(aHigh.allparams(), lowSub.allparams())
1867 && !disjointTypes(aLow.allparams(), highSub.allparams())
1868 && !disjointTypes(aLow.allparams(), lowSub.allparams())) {
1869 if (upcast ? giveWarning(a, b) :
1870 giveWarning(b, a))
1871 warnStack.head.warn(LintCategory.UNCHECKED);
1872 return true;
1873 }
1874 }
1875 if (isReifiable(s))
1876 return isSubtypeUnchecked(a, b);
1877 else
1878 return isSubtypeUnchecked(a, b, warnStack.head);
1879 }
1880
1881 // Sidecast
1882 if (s.hasTag(CLASS)) {
1883 if ((s.tsym.flags() & INTERFACE) != 0) {
1884 return ((t.tsym.flags() & FINAL) == 0)
1885 ? sideCast(t, s, warnStack.head)
1886 : sideCastFinal(t, s, warnStack.head);
1887 } else if ((t.tsym.flags() & INTERFACE) != 0) {
1888 return ((s.tsym.flags() & FINAL) == 0)
1889 ? sideCast(t, s, warnStack.head)
1890 : sideCastFinal(t, s, warnStack.head);
1891 } else {
1892 // unrelated class types
1893 return false;
1894 }
1895 }
1896 }
1897 return false;
1898 }
1899
1900 boolean visitCompoundType(ClassType ct, Type s, boolean reverse) {
1901 Warner warn = noWarnings;
1902 for (Type c : directSupertypes(ct)) {
1903 warn.clear();
1904 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn))
1905 return false;
1906 }
1907 if (warn.hasLint(LintCategory.UNCHECKED))
1908 warnStack.head.warn(LintCategory.UNCHECKED);
1909 return true;
1910 }
1911
1912 @Override
1913 public Boolean visitArrayType(ArrayType t, Type s) {
1914 switch (s.getTag()) {
1915 case ERROR:
1916 case BOT:
1917 return true;
1918 case TYPEVAR:
1919 if (isCastable(s, t, noWarnings)) {
1920 warnStack.head.warn(LintCategory.UNCHECKED);
1921 return true;
1922 } else {
1923 return false;
1924 }
1925 case CLASS:
1926 return isSubtype(t, s);
1927 case ARRAY:
1928 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) {
1929 return elemtype(t).hasTag(elemtype(s).getTag());
1930 } else {
1931 return isCastable(elemtype(t), elemtype(s), warnStack.head);
1932 }
1933 default:
1934 return false;
1935 }
1936 }
1937
1938 @Override
1939 public Boolean visitTypeVar(TypeVar t, Type s) {
1940 switch (s.getTag()) {
1941 case ERROR:
1942 case BOT:
1943 return true;
1944 case TYPEVAR:
1945 if (isSubtype(t, s)) {
1946 return true;
1947 } else if (isCastable(t.getUpperBound(), s, noWarnings)) {
1948 warnStack.head.warn(LintCategory.UNCHECKED);
1949 return true;
1950 } else {
1951 return false;
1952 }
1953 default:
1954 return isCastable(t.getUpperBound(), s, warnStack.head);
1955 }
1956 }
1957
1958 @Override
1959 public Boolean visitErrorType(ErrorType t, Type s) {
1960 return true;
1961 }
1962 };
1963 // </editor-fold>
1964
1965 // <editor-fold defaultstate="collapsed" desc="disjointTypes">
1966 public boolean disjointTypes(List<Type> ts, List<Type> ss) {
1967 while (ts.tail != null && ss.tail != null) {
1968 if (disjointType(ts.head, ss.head)) return true;
1969 ts = ts.tail;
1970 ss = ss.tail;
1971 }
1972 return false;
1973 }
1974
1975 /**
1976 * Two types or wildcards are considered disjoint if it can be
1977 * proven that no type can be contained in both. It is
1978 * conservative in that it is allowed to say that two types are
1979 * not disjoint, even though they actually are.
1980 *
1981 * The type {@code C<X>} is castable to {@code C<Y>} exactly if
1982 * {@code X} and {@code Y} are not disjoint.
1983 */
1984 public boolean disjointType(Type t, Type s) {
1985 return disjointType.visit(t, s);
1986 }
1987 // where
1988 private TypeRelation disjointType = new TypeRelation() {
1989
1990 private Set<TypePair> cache = new HashSet<>();
1991
1992 @Override
1993 public Boolean visitType(Type t, Type s) {
1994 if (s.hasTag(WILDCARD))
1995 return visit(s, t);
1996 else
1997 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t);
1998 }
1999
2000 private boolean isCastableRecursive(Type t, Type s) {
2001 TypePair pair = new TypePair(t, s);
2002 if (cache.add(pair)) {
2003 try {
2004 return Types.this.isCastable(t, s);
2005 } finally {
2006 cache.remove(pair);
2007 }
2008 } else {
2009 return true;
2010 }
2011 }
2012
2013 private boolean notSoftSubtypeRecursive(Type t, Type s) {
2014 TypePair pair = new TypePair(t, s);
2015 if (cache.add(pair)) {
2016 try {
2017 return Types.this.notSoftSubtype(t, s);
2018 } finally {
2019 cache.remove(pair);
2020 }
2021 } else {
2022 return false;
2023 }
2024 }
2025
2026 @Override
2027 public Boolean visitWildcardType(WildcardType t, Type s) {
2028 if (t.isUnbound())
2029 return false;
2030
2031 if (!s.hasTag(WILDCARD)) {
2032 if (t.isExtendsBound())
2033 return notSoftSubtypeRecursive(s, t.type);
2034 else
2035 return notSoftSubtypeRecursive(t.type, s);
2036 }
2037
2038 if (s.isUnbound())
2039 return false;
2040
2041 if (t.isExtendsBound()) {
2042 if (s.isExtendsBound())
2043 return !isCastableRecursive(t.type, wildUpperBound(s));
2044 else if (s.isSuperBound())
2045 return notSoftSubtypeRecursive(wildLowerBound(s), t.type);
2046 } else if (t.isSuperBound()) {
2047 if (s.isExtendsBound())
2048 return notSoftSubtypeRecursive(t.type, wildUpperBound(s));
2049 }
2050 return false;
2051 }
2052 };
2053 // </editor-fold>
2054
2055 // <editor-fold defaultstate="collapsed" desc="cvarLowerBounds">
2056 public List<Type> cvarLowerBounds(List<Type> ts) {
2057 return ts.map(cvarLowerBoundMapping);
2058 }
2059 private final TypeMapping<Void> cvarLowerBoundMapping = new TypeMapping<Void>() {
2060 @Override
2061 public Type visitCapturedType(CapturedType t, Void _unused) {
2062 return cvarLowerBound(t);
2063 }
2064 };
2065 // </editor-fold>
2066
2067 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype">
2068 /**
2069 * This relation answers the question: is impossible that
2070 * something of type `t' can be a subtype of `s'? This is
2071 * different from the question "is `t' not a subtype of `s'?"
2072 * when type variables are involved: Integer is not a subtype of T
2073 * where {@code <T extends Number>} but it is not true that Integer cannot
2074 * possibly be a subtype of T.
2075 */
2076 public boolean notSoftSubtype(Type t, Type s) {
2077 if (t == s) return false;
2078 if (t.hasTag(TYPEVAR)) {
2079 TypeVar tv = (TypeVar) t;
2080 return !isCastable(tv.getUpperBound(),
2081 relaxBound(s),
2082 noWarnings);
2083 }
2084 if (!s.hasTag(WILDCARD))
2085 s = cvarUpperBound(s);
2086
2087 return !isSubtype(t, relaxBound(s));
2088 }
2089
2090 private Type relaxBound(Type t) {
2091 return (t.hasTag(TYPEVAR)) ?
2092 rewriteQuantifiers(skipTypeVars(t, false), true, true) :
2093 t;
2094 }
2095 // </editor-fold>
2096
2097 // <editor-fold defaultstate="collapsed" desc="isReifiable">
2098 public boolean isReifiable(Type t) {
2099 return isReifiable.visit(t);
2100 }
2101 // where
2102 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() {
2103
2104 public Boolean visitType(Type t, Void ignored) {
2105 return true;
2106 }
2107
2108 @Override
2109 public Boolean visitClassType(ClassType t, Void ignored) {
2110 if (t.isCompound())
2111 return false;
2112 else {
2113 if (!t.isParameterized())
2114 return true;
2115
2116 for (Type param : t.allparams()) {
2117 if (!param.isUnbound())
2118 return false;
2119 }
2120 return true;
2121 }
2122 }
2123
2124 @Override
2125 public Boolean visitArrayType(ArrayType t, Void ignored) {
2126 return visit(t.elemtype);
2127 }
2128
2129 @Override
2130 public Boolean visitTypeVar(TypeVar t, Void ignored) {
2131 return false;
2132 }
2133 };
2134 // </editor-fold>
2135
2136 // <editor-fold defaultstate="collapsed" desc="Array Utils">
2137 public boolean isArray(Type t) {
2138 while (t.hasTag(WILDCARD))
2139 t = wildUpperBound(t);
2140 return t.hasTag(ARRAY);
2141 }
2142
2143 /**
2144 * The element type of an array.
2145 */
2146 public Type elemtype(Type t) {
2147 switch (t.getTag()) {
2148 case WILDCARD:
2149 return elemtype(wildUpperBound(t));
2150 case ARRAY:
2151 return ((ArrayType)t).elemtype;
2152 case FORALL:
2153 return elemtype(((ForAll)t).qtype);
2154 case ERROR:
2155 return t;
2156 default:
2157 return null;
2158 }
2159 }
2160
2161 public Type elemtypeOrType(Type t) {
2162 Type elemtype = elemtype(t);
2163 return elemtype != null ?
2164 elemtype :
2165 t;
2166 }
2167
2168 /**
2169 * Mapping to take element type of an arraytype
2170 */
2171 private TypeMapping<Void> elemTypeFun = new TypeMapping<Void>() {
2172 @Override
2173 public Type visitArrayType(ArrayType t, Void _unused) {
2174 return t.elemtype;
2175 }
2176
2177 @Override
2178 public Type visitTypeVar(TypeVar t, Void _unused) {
2179 return visit(skipTypeVars(t, false));
2180 }
2181 };
2182
2183 /**
2184 * The number of dimensions of an array type.
2185 */
2186 public int dimensions(Type t) {
2187 int result = 0;
2188 while (t.hasTag(ARRAY)) {
2189 result++;
2190 t = elemtype(t);
2191 }
2192 return result;
2193 }
2194
2195 /**
2196 * Returns an ArrayType with the component type t
2197 *
2198 * @param t The component type of the ArrayType
2199 * @return the ArrayType for the given component
2200 */
2201 public ArrayType makeArrayType(Type t) {
2202 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) {
2203 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString());
2204 }
2205 return new ArrayType(t, syms.arrayClass);
2206 }
2207 // </editor-fold>
2208
2209 // <editor-fold defaultstate="collapsed" desc="asSuper">
2210 /**
2211 * Return the (most specific) base type of t that starts with the
2212 * given symbol. If none exists, return null.
2213 *
2214 * Caveat Emptor: Since javac represents the class of all arrays with a singleton
2215 * symbol Symtab.arrayClass, which by being a singleton cannot hold any discriminant,
2216 * this method could yield surprising answers when invoked on arrays. For example when
2217 * invoked with t being byte [] and sym being t.sym itself, asSuper would answer null.
2218 *
2219 * Further caveats in Valhalla: There are two "hazards" we need to watch out for when using
2220 * this method.
2221 *
2222 * 1. Since Foo.ref and Foo.val share the same symbol, that of Foo.class, a call to
2223 * asSuper(Foo.ref.type, Foo.val.type.tsym) would return non-null. This MAY NOT BE correct
2224 * depending on the call site. Foo.val is NOT a super type of Foo.ref either in the language
2225 * model or in the VM's world view. An example of such an hazardous call used to exist in
2226 * Gen.visitTypeCast. When we emit code for (Foo) Foo.ref.instance a check for whether we
2227 * really need the cast cannot/shouldn't be gated on
2228 *
2229 * asSuper(tree.expr.type, tree.clazz.type.tsym) == null)
2230 *
2231 * but use !types.isSubtype(tree.expr.type, tree.clazz.type) which operates in terms of
2232 * types. When we operate in terms of symbols, there is a loss of type information leading
2233 * to a hazard. Whether a call to asSuper should be transformed into a isSubtype call is
2234 * tricky. isSubtype returns just a boolean while asSuper returns richer information which
2235 * may be required at the call site. Also where the concerned symbol corresponds to a
2236 * generic class, an asSuper call cannot be conveniently rewritten as an isSubtype call
2237 * (see that asSuper(ArrayList<String>.type, List<T>.tsym) != null while
2238 * isSubType(ArrayList<String>.type, List<T>.type) is false;) So care needs to be exercised.
2239 *
2240 * 2. Given a primitive class Foo, a call to asSuper(Foo.type, SuperclassOfFoo.tsym) and/or
2241 * a call to asSuper(Foo.type, SuperinterfaceOfFoo.tsym) would answer null. In many places
2242 * that is NOT what we want. An example of such a hazardous call used to occur in
2243 * Attr.visitForeachLoop when checking to make sure the for loop's control variable of a type
2244 * that implements Iterable: viz: types.asSuper(exprType, syms.iterableType.tsym);
2245 * These hazardous calls should be rewritten as
2246 * types.asSuper(exprType.referenceProjectionOrSelf(), syms.iterableType.tsym); instead.
2247 *
2248 * @param t a type
2249 * @param sym a symbol
2250 */
2251 public Type asSuper(Type t, Symbol sym) {
2252 /* Some examples:
2253 *
2254 * (Enum<E>, Comparable) => Comparable<E>
2255 * (c.s.s.d.AttributeTree.ValueKind, Enum) => Enum<c.s.s.d.AttributeTree.ValueKind>
2256 * (c.s.s.t.ExpressionTree, c.s.s.t.Tree) => c.s.s.t.Tree
2257 * (j.u.List<capture#160 of ? extends c.s.s.d.DocTree>, Iterable) =>
2258 * Iterable<capture#160 of ? extends c.s.s.d.DocTree>
2259 */
2260
2261 if (allowPrimitiveClasses && t.isPrimitiveClass()) {
2262 // No man may be an island, but the bell tolls for a value.
2263 return t.tsym == sym ? t : null;
2264 }
2265
2266 if (sym.type == syms.objectType) { //optimization
2267 return syms.objectType;
2268 }
2269 return asSuper.visit(t, sym);
2270 }
2271 // where
2272 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() {
2273
2274 private Set<Symbol> seenTypes = new HashSet<>();
2275
2276 public Type visitType(Type t, Symbol sym) {
2277 return null;
2278 }
2279
2280 @Override
2281 public Type visitClassType(ClassType t, Symbol sym) {
2282 if (t.tsym == sym)
2283 return t;
2284
2285 Symbol c = t.tsym;
2286 if (!seenTypes.add(c)) {
2287 return null;
2288 }
2289 try {
2290 Type st = supertype(t);
2291 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) {
2292 Type x = asSuper(st, sym);
2293 if (x != null)
2294 return x;
2295 }
2296 if ((sym.flags() & INTERFACE) != 0) {
2297 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
2298 if (!l.head.hasTag(ERROR)) {
2299 Type x = asSuper(l.head, sym);
2300 if (x != null)
2301 return x;
2302 }
2303 }
2304 }
2305 return null;
2306 } finally {
2307 seenTypes.remove(c);
2308 }
2309 }
2310
2311 @Override
2312 public Type visitArrayType(ArrayType t, Symbol sym) {
2313 return isSubtype(t, sym.type) ? sym.type : null;
2314 }
2315
2316 @Override
2317 public Type visitTypeVar(TypeVar t, Symbol sym) {
2318 if (t.tsym == sym)
2319 return t;
2320 else
2321 return asSuper(t.getUpperBound(), sym);
2322 }
2323
2324 @Override
2325 public Type visitErrorType(ErrorType t, Symbol sym) {
2326 return t;
2327 }
2328 };
2329
2330 /**
2331 * Return the base type of t or any of its outer types that starts
2332 * with the given symbol. If none exists, return null.
2333 *
2334 * @param t a type
2335 * @param sym a symbol
2336 */
2337 public Type asOuterSuper(Type t, Symbol sym) {
2338 switch (t.getTag()) {
2339 case CLASS:
2340 do {
2341 Type s = asSuper(t, sym);
2342 if (s != null) return s;
2343 t = t.getEnclosingType();
2344 } while (t.hasTag(CLASS));
2345 return null;
2346 case ARRAY:
2347 return isSubtype(t, sym.type) ? sym.type : null;
2348 case TYPEVAR:
2349 return asSuper(t, sym);
2350 case ERROR:
2351 return t;
2352 default:
2353 return null;
2354 }
2355 }
2356
2357 /**
2358 * Return the base type of t or any of its enclosing types that
2359 * starts with the given symbol. If none exists, return null.
2360 *
2361 * @param t a type
2362 * @param sym a symbol
2363 */
2364 public Type asEnclosingSuper(Type t, Symbol sym) {
2365 switch (t.getTag()) {
2366 case CLASS:
2367 do {
2368 Type s = asSuper(t, sym);
2369 if (s != null) return s;
2370 Type outer = t.getEnclosingType();
2371 t = (outer.hasTag(CLASS)) ? outer :
2372 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type :
2373 Type.noType;
2374 } while (t.hasTag(CLASS));
2375 return null;
2376 case ARRAY:
2377 return isSubtype(t, sym.type) ? sym.type : null;
2378 case TYPEVAR:
2379 return asSuper(t, sym);
2380 case ERROR:
2381 return t;
2382 default:
2383 return null;
2384 }
2385 }
2386 // </editor-fold>
2387
2388 // <editor-fold defaultstate="collapsed" desc="memberType">
2389 /**
2390 * The type of given symbol, seen as a member of t.
2391 *
2392 * @param t a type
2393 * @param sym a symbol
2394 */
2395 public Type memberType(Type t, Symbol sym) {
2396
2397 if ((sym.flags() & STATIC) != 0)
2398 return sym.type;
2399
2400 /* If any primitive class types are involved, switch over to the reference universe,
2401 where the hierarchy is navigable. V and V.ref have identical membership
2402 with no bridging needs.
2403 */
2404 if (allowPrimitiveClasses && t.isPrimitiveClass())
2405 t = t.referenceProjection();
2406
2407 return memberType.visit(t, sym);
2408 }
2409 // where
2410 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() {
2411
2412 public Type visitType(Type t, Symbol sym) {
2413 return sym.type;
2414 }
2415
2416 @Override
2417 public Type visitWildcardType(WildcardType t, Symbol sym) {
2418 return memberType(wildUpperBound(t), sym);
2419 }
2420
2421 @Override
2422 public Type visitClassType(ClassType t, Symbol sym) {
2423 Symbol owner = sym.owner;
2424 long flags = sym.flags();
2425 if (((flags & STATIC) == 0) && owner.type.isParameterized()) {
2426 Type base = asOuterSuper(t, owner);
2427 //if t is an intersection type T = CT & I1 & I2 ... & In
2428 //its supertypes CT, I1, ... In might contain wildcards
2429 //so we need to go through capture conversion
2430 base = t.isCompound() ? capture(base) : base;
2431 if (base != null) {
2432 List<Type> ownerParams = owner.type.allparams();
2433 List<Type> baseParams = base.allparams();
2434 if (ownerParams.nonEmpty()) {
2435 if (baseParams.isEmpty()) {
2436 // then base is a raw type
2437 return erasure(sym.type);
2438 } else {
2439 return subst(sym.type, ownerParams, baseParams);
2440 }
2441 }
2442 }
2443 }
2444 return sym.type;
2445 }
2446
2447 @Override
2448 public Type visitTypeVar(TypeVar t, Symbol sym) {
2449 return memberType(t.getUpperBound(), sym);
2450 }
2451
2452 @Override
2453 public Type visitErrorType(ErrorType t, Symbol sym) {
2454 return t;
2455 }
2456 };
2457 // </editor-fold>
2458
2459 // <editor-fold defaultstate="collapsed" desc="isAssignable">
2460 public boolean isAssignable(Type t, Type s) {
2461 return isAssignable(t, s, noWarnings);
2462 }
2463
2464 /**
2465 * Is t assignable to s?<br>
2466 * Equivalent to subtype except for constant values and raw
2467 * types.<br>
2468 * (not defined for Method and ForAll types)
2469 */
2470 public boolean isAssignable(Type t, Type s, Warner warn) {
2471 if (t.hasTag(ERROR))
2472 return true;
2473 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) {
2474 int value = ((Number)t.constValue()).intValue();
2475 switch (s.getTag()) {
2476 case BYTE:
2477 case CHAR:
2478 case SHORT:
2479 case INT:
2480 if (s.getTag().checkRange(value))
2481 return true;
2482 break;
2483 case CLASS:
2484 switch (unboxedType(s).getTag()) {
2485 case BYTE:
2486 case CHAR:
2487 case SHORT:
2488 return isAssignable(t, unboxedType(s), warn);
2489 }
2490 break;
2491 }
2492 }
2493 return isConvertible(t, s, warn);
2494 }
2495 // </editor-fold>
2496
2497 // <editor-fold defaultstate="collapsed" desc="erasure">
2498 /**
2499 * The erasure of t {@code |t|} -- the type that results when all
2500 * type parameters in t are deleted.
2501 */
2502 public Type erasure(Type t) {
2503 return eraseNotNeeded(t) ? t : erasure(t, false);
2504 }
2505 //where
2506 private boolean eraseNotNeeded(Type t) {
2507 // We don't want to erase primitive types and String type as that
2508 // operation is idempotent. Also, erasing these could result in loss
2509 // of information such as constant values attached to such types.
2510 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym);
2511 }
2512
2513 private Type erasure(Type t, boolean recurse) {
2514 if (t.isPrimitive()) {
2515 return t; /* fast special case */
2516 } else {
2517 Type out = erasure.visit(t, recurse);
2518 return out;
2519 }
2520 }
2521 // where
2522 private TypeMapping<Boolean> erasure = new StructuralTypeMapping<Boolean>() {
2523 private Type combineMetadata(final Type s,
2524 final Type t) {
2525 if (t.getMetadata() != TypeMetadata.EMPTY) {
2526 switch (s.getKind()) {
2527 case OTHER:
2528 case UNION:
2529 case INTERSECTION:
2530 case PACKAGE:
2531 case EXECUTABLE:
2532 case NONE:
2533 case VOID:
2534 case ERROR:
2535 return s;
2536 default: return s.cloneWithMetadata(s.getMetadata().without(Kind.ANNOTATIONS));
2537 }
2538 } else {
2539 return s;
2540 }
2541 }
2542
2543 public Type visitType(Type t, Boolean recurse) {
2544 if (t.isPrimitive())
2545 return t; /*fast special case*/
2546 else {
2547 //other cases already handled
2548 return combineMetadata(t, t);
2549 }
2550 }
2551
2552 @Override
2553 public Type visitWildcardType(WildcardType t, Boolean recurse) {
2554 Type erased = erasure(wildUpperBound(t), recurse);
2555 return combineMetadata(erased, t);
2556 }
2557
2558 @Override
2559 public Type visitClassType(ClassType t, Boolean recurse) {
2560 // erasure(projection(primitive)) = projection(erasure(primitive))
2561 Type erased = eraseClassType(t, recurse);
2562 if (erased.hasTag(CLASS) && t.flavor != erased.getFlavor()) {
2563 erased = new ClassType(erased.getEnclosingType(),
2564 List.nil(), erased.tsym,
2565 erased.getMetadata(), t.flavor);
2566 }
2567 return erased;
2568 }
2569 // where
2570 private Type eraseClassType(ClassType t, Boolean recurse) {
2571 Type erased = t.tsym.erasure(Types.this);
2572 if (recurse) {
2573 erased = new ErasedClassType(erased.getEnclosingType(), erased.tsym,
2574 t.getMetadata().without(Kind.ANNOTATIONS));
2575 return erased;
2576 } else {
2577 return combineMetadata(erased, t);
2578 }
2579 }
2580
2581 @Override
2582 public Type visitTypeVar(TypeVar t, Boolean recurse) {
2583 Type erased = erasure(t.getUpperBound(), recurse);
2584 return combineMetadata(erased, t);
2585 }
2586 };
2587
2588 public List<Type> erasure(List<Type> ts) {
2589 return erasure.visit(ts, false);
2590 }
2591
2592 public Type erasureRecursive(Type t) {
2593 return erasure(t, true);
2594 }
2595
2596 public List<Type> erasureRecursive(List<Type> ts) {
2597 return erasure.visit(ts, true);
2598 }
2599 // </editor-fold>
2600
2601 // <editor-fold defaultstate="collapsed" desc="makeIntersectionType">
2602 /**
2603 * Make an intersection type from non-empty list of types. The list should be ordered according to
2604 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. Note that this might cause a symbol completion.
2605 * Hence, this version of makeIntersectionType may not be called during a classfile read.
2606 *
2607 * @param bounds the types from which the intersection type is formed
2608 */
2609 public IntersectionClassType makeIntersectionType(List<Type> bounds) {
2610 return makeIntersectionType(bounds, bounds.head.tsym.isInterface());
2611 }
2612
2613 /**
2614 * Make an intersection type from non-empty list of types. The list should be ordered according to
2615 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. This does not cause symbol completion as
2616 * an extra parameter indicates as to whether all bounds are interfaces - in which case the
2617 * supertype is implicitly assumed to be 'Object'.
2618 *
2619 * @param bounds the types from which the intersection type is formed
2620 * @param allInterfaces are all bounds interface types?
2621 */
2622 public IntersectionClassType makeIntersectionType(List<Type> bounds, boolean allInterfaces) {
2623 Assert.check(bounds.nonEmpty());
2624 Type firstExplicitBound = bounds.head;
2625 if (allInterfaces) {
2626 bounds = bounds.prepend(syms.objectType);
2627 }
2628 ClassSymbol bc =
2629 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC,
2630 Type.moreInfo
2631 ? names.fromString(bounds.toString())
2632 : names.empty,
2633 null,
2634 syms.noSymbol);
2635 IntersectionClassType intersectionType = new IntersectionClassType(bounds, bc, allInterfaces);
2636 bc.type = intersectionType;
2637 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ?
2638 syms.objectType : // error condition, recover
2639 erasure(firstExplicitBound);
2640 bc.members_field = WriteableScope.create(bc);
2641 return intersectionType;
2642 }
2643 // </editor-fold>
2644
2645 // <editor-fold defaultstate="collapsed" desc="supertype">
2646 public Type supertype(Type t) {
2647 return supertype.visit(t);
2648 }
2649 // where
2650 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() {
2651
2652 public Type visitType(Type t, Void ignored) {
2653 // A note on wildcards: there is no good way to
2654 // determine a supertype for a lower-bounded wildcard.
2655 return Type.noType;
2656 }
2657
2658 @Override
2659 public Type visitClassType(ClassType t, Void ignored) {
2660 if (t.supertype_field == null) {
2661 Type supertype = ((ClassSymbol)t.tsym).getSuperclass();
2662 // An interface has no superclass; its supertype is Object.
2663 if (t.isInterface())
2664 supertype = ((ClassType)t.tsym.type).supertype_field;
2665 if (t.supertype_field == null) {
2666 List<Type> actuals = classBound(t).allparams();
2667 List<Type> formals = t.tsym.type.allparams();
2668 if (t.hasErasedSupertypes()) {
2669 t.supertype_field = erasureRecursive(supertype);
2670 } else if (formals.nonEmpty()) {
2671 t.supertype_field = subst(supertype, formals, actuals);
2672 }
2673 else {
2674 t.supertype_field = supertype;
2675 }
2676 }
2677 }
2678 return t.supertype_field;
2679 }
2680
2681 /**
2682 * The supertype is always a class type. If the type
2683 * variable's bounds start with a class type, this is also
2684 * the supertype. Otherwise, the supertype is
2685 * java.lang.Object.
2686 */
2687 @Override
2688 public Type visitTypeVar(TypeVar t, Void ignored) {
2689 if (t.getUpperBound().hasTag(TYPEVAR) ||
2690 (!t.getUpperBound().isCompound() && !t.getUpperBound().isInterface())) {
2691 return t.getUpperBound();
2692 } else {
2693 return supertype(t.getUpperBound());
2694 }
2695 }
2696
2697 @Override
2698 public Type visitArrayType(ArrayType t, Void ignored) {
2699 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType))
2700 return arraySuperType();
2701 else
2702 return new ArrayType(supertype(t.elemtype), t.tsym);
2703 }
2704
2705 @Override
2706 public Type visitErrorType(ErrorType t, Void ignored) {
2707 return Type.noType;
2708 }
2709 };
2710 // </editor-fold>
2711
2712 // <editor-fold defaultstate="collapsed" desc="interfaces">
2713 /**
2714 * Return the interfaces implemented by this class.
2715 */
2716 public List<Type> interfaces(Type t) {
2717 return interfaces.visit(t);
2718 }
2719 // where
2720 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() {
2721
2722 public List<Type> visitType(Type t, Void ignored) {
2723 return List.nil();
2724 }
2725
2726 @Override
2727 public List<Type> visitClassType(ClassType t, Void ignored) {
2728 if (t.interfaces_field == null) {
2729 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces();
2730 if (t.interfaces_field == null) {
2731 // If t.interfaces_field is null, then t must
2732 // be a parameterized type (not to be confused
2733 // with a generic type declaration).
2734 // Terminology:
2735 // Parameterized type: List<String>
2736 // Generic type declaration: class List<E> { ... }
2737 // So t corresponds to List<String> and
2738 // t.tsym.type corresponds to List<E>.
2739 // The reason t must be parameterized type is
2740 // that completion will happen as a side
2741 // effect of calling
2742 // ClassSymbol.getInterfaces. Since
2743 // t.interfaces_field is null after
2744 // completion, we can assume that t is not the
2745 // type of a class/interface declaration.
2746 Assert.check(t != t.tsym.type, t);
2747 List<Type> actuals = t.allparams();
2748 List<Type> formals = t.tsym.type.allparams();
2749 if (t.hasErasedSupertypes()) {
2750 t.interfaces_field = erasureRecursive(interfaces);
2751 } else if (formals.nonEmpty()) {
2752 t.interfaces_field = subst(interfaces, formals, actuals);
2753 }
2754 else {
2755 t.interfaces_field = interfaces;
2756 }
2757 }
2758 }
2759 return t.interfaces_field;
2760 }
2761
2762 @Override
2763 public List<Type> visitTypeVar(TypeVar t, Void ignored) {
2764 if (t.getUpperBound().isCompound())
2765 return interfaces(t.getUpperBound());
2766
2767 if (t.getUpperBound().isInterface())
2768 return List.of(t.getUpperBound());
2769
2770 return List.nil();
2771 }
2772 };
2773
2774 public List<Type> directSupertypes(Type t) {
2775 return directSupertypes.visit(t);
2776 }
2777 // where
2778 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() {
2779
2780 public List<Type> visitType(final Type type, final Void ignored) {
2781 if (!type.isIntersection()) {
2782 final Type sup = supertype(type);
2783 return (sup == Type.noType || sup == type || sup == null)
2784 ? interfaces(type)
2785 : interfaces(type).prepend(sup);
2786 } else {
2787 return ((IntersectionClassType)type).getExplicitComponents();
2788 }
2789 }
2790 };
2791
2792 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) {
2793 for (Type i2 : interfaces(origin.type)) {
2794 if (isym == i2.tsym) return true;
2795 }
2796 return false;
2797 }
2798 // </editor-fold>
2799
2800 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw">
2801 Map<Type,Boolean> isDerivedRawCache = new HashMap<>();
2802
2803 public boolean isDerivedRaw(Type t) {
2804 Boolean result = isDerivedRawCache.get(t);
2805 if (result == null) {
2806 result = isDerivedRawInternal(t);
2807 isDerivedRawCache.put(t, result);
2808 }
2809 return result;
2810 }
2811
2812 public boolean isDerivedRawInternal(Type t) {
2813 if (t.isErroneous())
2814 return false;
2815 return
2816 t.isRaw() ||
2817 supertype(t) != Type.noType && isDerivedRaw(supertype(t)) ||
2818 isDerivedRaw(interfaces(t));
2819 }
2820
2821 public boolean isDerivedRaw(List<Type> ts) {
2822 List<Type> l = ts;
2823 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail;
2824 return l.nonEmpty();
2825 }
2826 // </editor-fold>
2827
2828 // <editor-fold defaultstate="collapsed" desc="setBounds">
2829 /**
2830 * Same as {@link Types#setBounds(TypeVar, List, boolean)}, except that third parameter is computed directly,
2831 * as follows: if all all bounds are interface types, the computed supertype is Object,otherwise
2832 * the supertype is simply left null (in this case, the supertype is assumed to be the head of
2833 * the bound list passed as second argument). Note that this check might cause a symbol completion.
2834 * Hence, this version of setBounds may not be called during a classfile read.
2835 *
2836 * @param t a type variable
2837 * @param bounds the bounds, must be nonempty
2838 */
2839 public void setBounds(TypeVar t, List<Type> bounds) {
2840 setBounds(t, bounds, bounds.head.tsym.isInterface());
2841 }
2842
2843 /**
2844 * Set the bounds field of the given type variable to reflect a (possibly multiple) list of bounds.
2845 * This does not cause symbol completion as an extra parameter indicates as to whether all bounds
2846 * are interfaces - in which case the supertype is implicitly assumed to be 'Object'.
2847 *
2848 * @param t a type variable
2849 * @param bounds the bounds, must be nonempty
2850 * @param allInterfaces are all bounds interface types?
2851 */
2852 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) {
2853 t.setUpperBound( bounds.tail.isEmpty() ?
2854 bounds.head :
2855 makeIntersectionType(bounds, allInterfaces) );
2856 t.rank_field = -1;
2857 }
2858 // </editor-fold>
2859
2860 // <editor-fold defaultstate="collapsed" desc="getBounds">
2861 /**
2862 * Return list of bounds of the given type variable.
2863 */
2864 public List<Type> getBounds(TypeVar t) {
2865 if (t.getUpperBound().hasTag(NONE))
2866 return List.nil();
2867 else if (t.getUpperBound().isErroneous() || !t.getUpperBound().isCompound())
2868 return List.of(t.getUpperBound());
2869 else if ((erasure(t).tsym.flags() & INTERFACE) == 0)
2870 return interfaces(t).prepend(supertype(t));
2871 else
2872 // No superclass was given in bounds.
2873 // In this case, supertype is Object, erasure is first interface.
2874 return interfaces(t);
2875 }
2876 // </editor-fold>
2877
2878 // <editor-fold defaultstate="collapsed" desc="classBound">
2879 /**
2880 * If the given type is a (possibly selected) type variable,
2881 * return the bounding class of this type, otherwise return the
2882 * type itself.
2883 */
2884 public Type classBound(Type t) {
2885 return classBound.visit(t);
2886 }
2887 // where
2888 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() {
2889
2890 public Type visitType(Type t, Void ignored) {
2891 return t;
2892 }
2893
2894 @Override
2895 public Type visitClassType(ClassType t, Void ignored) {
2896 Type outer1 = classBound(t.getEnclosingType());
2897 if (outer1 != t.getEnclosingType())
2898 return new ClassType(outer1, t.getTypeArguments(), t.tsym,
2899 t.getMetadata(), t.getFlavor());
2900 else
2901 return t;
2902 }
2903
2904 @Override
2905 public Type visitTypeVar(TypeVar t, Void ignored) {
2906 return classBound(supertype(t));
2907 }
2908
2909 @Override
2910 public Type visitErrorType(ErrorType t, Void ignored) {
2911 return t;
2912 }
2913 };
2914 // </editor-fold>
2915
2916 // <editor-fold defaultstate="collapsed" desc="subsignature / override equivalence">
2917 /**
2918 * Returns true iff the first signature is a <em>subsignature</em>
2919 * of the other. This is <b>not</b> an equivalence
2920 * relation.
2921 *
2922 * @jls 8.4.2 Method Signature
2923 * @see #overrideEquivalent(Type t, Type s)
2924 * @param t first signature (possibly raw).
2925 * @param s second signature (could be subjected to erasure).
2926 * @return true if t is a subsignature of s.
2927 */
2928 public boolean isSubSignature(Type t, Type s) {
2929 return hasSameArgs(t, s, true) || hasSameArgs(t, erasure(s), true);
2930 }
2931
2932 /**
2933 * Returns true iff these signatures are related by <em>override
2934 * equivalence</em>. This is the natural extension of
2935 * isSubSignature to an equivalence relation.
2936 *
2937 * @jls 8.4.2 Method Signature
2938 * @see #isSubSignature(Type t, Type s)
2939 * @param t a signature (possible raw, could be subjected to
2940 * erasure).
2941 * @param s a signature (possible raw, could be subjected to
2942 * erasure).
2943 * @return true if either argument is a subsignature of the other.
2944 */
2945 public boolean overrideEquivalent(Type t, Type s) {
2946 return hasSameArgs(t, s) ||
2947 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s);
2948 }
2949
2950 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) {
2951 for (Symbol sym : syms.objectType.tsym.members().getSymbolsByName(msym.name)) {
2952 if (msym.overrides(sym, origin, Types.this, true)) {
2953 return true;
2954 }
2955 }
2956 return false;
2957 }
2958
2959 /**
2960 * This enum defines the strategy for implementing most specific return type check
2961 * during the most specific and functional interface checks.
2962 */
2963 public enum MostSpecificReturnCheck {
2964 /**
2965 * Return r1 is more specific than r2 if {@code r1 <: r2}. Extra care required for (i) handling
2966 * method type variables (if either method is generic) and (ii) subtyping should be replaced
2967 * by type-equivalence for primitives. This is essentially an inlined version of
2968 * {@link Types#resultSubtype(Type, Type, Warner)}, where the assignability check has been
2969 * replaced with a strict subtyping check.
2970 */
2971 BASIC() {
2972 @Override
2973 public boolean test(Type mt1, Type mt2, Types types) {
2974 List<Type> tvars = mt1.getTypeArguments();
2975 List<Type> svars = mt2.getTypeArguments();
2976 Type t = mt1.getReturnType();
2977 Type s = types.subst(mt2.getReturnType(), svars, tvars);
2978 return types.isSameType(t, s) ||
2979 !t.isPrimitive() &&
2980 !s.isPrimitive() &&
2981 types.isSubtype(t, s);
2982 }
2983 },
2984 /**
2985 * Return r1 is more specific than r2 if r1 is return-type-substitutable for r2.
2986 */
2987 RTS() {
2988 @Override
2989 public boolean test(Type mt1, Type mt2, Types types) {
2990 return types.returnTypeSubstitutable(mt1, mt2);
2991 }
2992 };
2993
2994 public abstract boolean test(Type mt1, Type mt2, Types types);
2995 }
2996
2997 /**
2998 * Merge multiple abstract methods. The preferred method is a method that is a subsignature
2999 * of all the other signatures and whose return type is more specific {@see MostSpecificReturnCheck}.
3000 * The resulting preferred method has a thrown clause that is the intersection of the merged
3001 * methods' clauses.
3002 */
3003 public Optional<Symbol> mergeAbstracts(List<Symbol> ambiguousInOrder, Type site, boolean sigCheck) {
3004 //first check for preconditions
3005 boolean shouldErase = false;
3006 List<Type> erasedParams = ambiguousInOrder.head.erasure(this).getParameterTypes();
3007 for (Symbol s : ambiguousInOrder) {
3008 if ((s.flags() & ABSTRACT) == 0 ||
3009 (sigCheck && !isSameTypes(erasedParams, s.erasure(this).getParameterTypes()))) {
3010 return Optional.empty();
3011 } else if (s.type.hasTag(FORALL)) {
3012 shouldErase = true;
3013 }
3014 }
3015 //then merge abstracts
3016 for (MostSpecificReturnCheck mostSpecificReturnCheck : MostSpecificReturnCheck.values()) {
3017 outer: for (Symbol s : ambiguousInOrder) {
3018 Type mt = memberType(site, s);
3019 List<Type> allThrown = mt.getThrownTypes();
3020 for (Symbol s2 : ambiguousInOrder) {
3021 if (s != s2) {
3022 Type mt2 = memberType(site, s2);
3023 if (!isSubSignature(mt, mt2) ||
3024 !mostSpecificReturnCheck.test(mt, mt2, this)) {
3025 //ambiguity cannot be resolved
3026 continue outer;
3027 } else {
3028 List<Type> thrownTypes2 = mt2.getThrownTypes();
3029 if (!mt.hasTag(FORALL) && shouldErase) {
3030 thrownTypes2 = erasure(thrownTypes2);
3031 } else if (mt.hasTag(FORALL)) {
3032 //subsignature implies that if most specific is generic, then all other
3033 //methods are too
3034 Assert.check(mt2.hasTag(FORALL));
3035 // if both are generic methods, adjust thrown types ahead of intersection computation
3036 thrownTypes2 = subst(thrownTypes2, mt2.getTypeArguments(), mt.getTypeArguments());
3037 }
3038 allThrown = chk.intersect(allThrown, thrownTypes2);
3039 }
3040 }
3041 }
3042 return (allThrown == mt.getThrownTypes()) ?
3043 Optional.of(s) :
3044 Optional.of(new MethodSymbol(
3045 s.flags(),
3046 s.name,
3047 createMethodTypeWithThrown(s.type, allThrown),
3048 s.owner) {
3049 @Override
3050 public Symbol baseSymbol() {
3051 return s;
3052 }
3053 });
3054 }
3055 }
3056 return Optional.empty();
3057 }
3058
3059 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site">
3060 class ImplementationCache {
3061
3062 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map = new WeakHashMap<>();
3063
3064 class Entry {
3065 final MethodSymbol cachedImpl;
3066 final Predicate<Symbol> implFilter;
3067 final boolean checkResult;
3068 final int prevMark;
3069
3070 public Entry(MethodSymbol cachedImpl,
3071 Predicate<Symbol> scopeFilter,
3072 boolean checkResult,
3073 int prevMark) {
3074 this.cachedImpl = cachedImpl;
3075 this.implFilter = scopeFilter;
3076 this.checkResult = checkResult;
3077 this.prevMark = prevMark;
3078 }
3079
3080 boolean matches(Predicate<Symbol> scopeFilter, boolean checkResult, int mark) {
3081 return this.implFilter == scopeFilter &&
3082 this.checkResult == checkResult &&
3083 this.prevMark == mark;
3084 }
3085 }
3086
3087 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3088 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms);
3089 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null;
3090 if (cache == null) {
3091 cache = new HashMap<>();
3092 _map.put(ms, new SoftReference<>(cache));
3093 }
3094 Entry e = cache.get(origin);
3095 CompoundScope members = membersClosure(origin.type, true);
3096 if (e == null ||
3097 !e.matches(implFilter, checkResult, members.getMark())) {
3098 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter);
3099 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark()));
3100 return impl;
3101 }
3102 else {
3103 return e.cachedImpl;
3104 }
3105 }
3106
3107 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3108 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) {
3109 t = skipTypeVars(t, false);
3110 TypeSymbol c = t.tsym;
3111 Symbol bestSoFar = null;
3112 for (Symbol sym : c.members().getSymbolsByName(ms.name, implFilter)) {
3113 if (sym != null && sym.overrides(ms, origin, Types.this, checkResult)) {
3114 bestSoFar = sym;
3115 if ((sym.flags() & ABSTRACT) == 0) {
3116 //if concrete impl is found, exit immediately
3117 break;
3118 }
3119 }
3120 }
3121 if (bestSoFar != null) {
3122 //return either the (only) concrete implementation or the first abstract one
3123 return (MethodSymbol)bestSoFar;
3124 }
3125 }
3126 return null;
3127 }
3128 }
3129
3130 private ImplementationCache implCache = new ImplementationCache();
3131
3132 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3133 return implCache.get(ms, origin, checkResult, implFilter);
3134 }
3135 // </editor-fold>
3136
3137 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site">
3138 class MembersClosureCache extends SimpleVisitor<Scope.CompoundScope, Void> {
3139
3140 private Map<TypeSymbol, CompoundScope> _map = new HashMap<>();
3141
3142 Set<TypeSymbol> seenTypes = new HashSet<>();
3143
3144 class MembersScope extends CompoundScope {
3145
3146 CompoundScope scope;
3147
3148 public MembersScope(CompoundScope scope) {
3149 super(scope.owner);
3150 this.scope = scope;
3151 }
3152
3153 Predicate<Symbol> combine(Predicate<Symbol> sf) {
3154 return s -> !s.owner.isInterface() && (sf == null || sf.test(s));
3155 }
3156
3157 @Override
3158 public Iterable<Symbol> getSymbols(Predicate<Symbol> sf, LookupKind lookupKind) {
3159 return scope.getSymbols(combine(sf), lookupKind);
3160 }
3161
3162 @Override
3163 public Iterable<Symbol> getSymbolsByName(Name name, Predicate<Symbol> sf, LookupKind lookupKind) {
3164 return scope.getSymbolsByName(name, combine(sf), lookupKind);
3165 }
3166
3167 @Override
3168 public int getMark() {
3169 return scope.getMark();
3170 }
3171 }
3172
3173 CompoundScope nilScope;
3174
3175 /** members closure visitor methods **/
3176
3177 public CompoundScope visitType(Type t, Void _unused) {
3178 if (nilScope == null) {
3179 nilScope = new CompoundScope(syms.noSymbol);
3180 }
3181 return nilScope;
3182 }
3183
3184 @Override
3185 public CompoundScope visitClassType(ClassType t, Void _unused) {
3186 if (!seenTypes.add(t.tsym)) {
3187 //this is possible when an interface is implemented in multiple
3188 //superclasses, or when a class hierarchy is circular - in such
3189 //cases we don't need to recurse (empty scope is returned)
3190 return new CompoundScope(t.tsym);
3191 }
3192 try {
3193 seenTypes.add(t.tsym);
3194 ClassSymbol csym = (ClassSymbol)t.tsym;
3195 CompoundScope membersClosure = _map.get(csym);
3196 if (membersClosure == null) {
3197 membersClosure = new CompoundScope(csym);
3198 for (Type i : interfaces(t)) {
3199 membersClosure.prependSubScope(visit(i, null));
3200 }
3201 membersClosure.prependSubScope(visit(supertype(t), null));
3202 membersClosure.prependSubScope(csym.members());
3203 _map.put(csym, membersClosure);
3204 }
3205 return membersClosure;
3206 }
3207 finally {
3208 seenTypes.remove(t.tsym);
3209 }
3210 }
3211
3212 @Override
3213 public CompoundScope visitTypeVar(TypeVar t, Void _unused) {
3214 return visit(t.getUpperBound(), null);
3215 }
3216 }
3217
3218 private MembersClosureCache membersCache = new MembersClosureCache();
3219
3220 public CompoundScope membersClosure(Type site, boolean skipInterface) {
3221 CompoundScope cs = membersCache.visit(site, null);
3222 Assert.checkNonNull(cs, () -> "type " + site);
3223 return skipInterface ? membersCache.new MembersScope(cs) : cs;
3224 }
3225 // </editor-fold>
3226
3227
3228 /** Return first abstract member of class `sym'.
3229 */
3230 public MethodSymbol firstUnimplementedAbstract(ClassSymbol sym) {
3231 try {
3232 return firstUnimplementedAbstractImpl(sym, sym);
3233 } catch (CompletionFailure ex) {
3234 chk.completionError(enter.getEnv(sym).tree.pos(), ex);
3235 return null;
3236 }
3237 }
3238 //where:
3239 private MethodSymbol firstUnimplementedAbstractImpl(ClassSymbol impl, ClassSymbol c) {
3240 MethodSymbol undef = null;
3241 // Do not bother to search in classes that are not abstract,
3242 // since they cannot have abstract members.
3243 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
3244 Scope s = c.members();
3245 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) {
3246 if (sym.kind == MTH &&
3247 (sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
3248 MethodSymbol absmeth = (MethodSymbol)sym;
3249 MethodSymbol implmeth = absmeth.implementation(impl, this, true);
3250 if (implmeth == null || implmeth == absmeth) {
3251 //look for default implementations
3252 MethodSymbol prov = interfaceCandidates(impl.type, absmeth).head;
3253 if (prov != null && prov.overrides(absmeth, impl, this, true)) {
3254 implmeth = prov;
3255 }
3256 }
3257 if (implmeth == null || implmeth == absmeth) {
3258 undef = absmeth;
3259 break;
3260 }
3261 }
3262 }
3263 if (undef == null) {
3264 Type st = supertype(c.type);
3265 if (st.hasTag(CLASS))
3266 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)st.tsym);
3267 }
3268 for (List<Type> l = interfaces(c.type);
3269 undef == null && l.nonEmpty();
3270 l = l.tail) {
3271 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)l.head.tsym);
3272 }
3273 }
3274 return undef;
3275 }
3276
3277 public class CandidatesCache {
3278 public Map<Entry, List<MethodSymbol>> cache = new WeakHashMap<>();
3279
3280 class Entry {
3281 Type site;
3282 MethodSymbol msym;
3283
3284 Entry(Type site, MethodSymbol msym) {
3285 this.site = site;
3286 this.msym = msym;
3287 }
3288
3289 @Override
3290 public boolean equals(Object obj) {
3291 return (obj instanceof Entry entry)
3292 && entry.msym == msym
3293 && isSameType(site, entry.site);
3294 }
3295
3296 @Override
3297 public int hashCode() {
3298 return Types.this.hashCode(site) & ~msym.hashCode();
3299 }
3300 }
3301
3302 public List<MethodSymbol> get(Entry e) {
3303 return cache.get(e);
3304 }
3305
3306 public void put(Entry e, List<MethodSymbol> msymbols) {
3307 cache.put(e, msymbols);
3308 }
3309 }
3310
3311 public CandidatesCache candidatesCache = new CandidatesCache();
3312
3313 //where
3314 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) {
3315 CandidatesCache.Entry e = candidatesCache.new Entry(site, ms);
3316 List<MethodSymbol> candidates = candidatesCache.get(e);
3317 if (candidates == null) {
3318 Predicate<Symbol> filter = new MethodFilter(ms, site);
3319 List<MethodSymbol> candidates2 = List.nil();
3320 for (Symbol s : membersClosure(site, false).getSymbols(filter)) {
3321 if (!site.tsym.isInterface() && !s.owner.isInterface()) {
3322 return List.of((MethodSymbol)s);
3323 } else if (!candidates2.contains(s)) {
3324 candidates2 = candidates2.prepend((MethodSymbol)s);
3325 }
3326 }
3327 candidates = prune(candidates2);
3328 candidatesCache.put(e, candidates);
3329 }
3330 return candidates;
3331 }
3332
3333 public List<MethodSymbol> prune(List<MethodSymbol> methods) {
3334 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>();
3335 for (MethodSymbol m1 : methods) {
3336 boolean isMin_m1 = true;
3337 for (MethodSymbol m2 : methods) {
3338 if (m1 == m2) continue;
3339 if (m2.owner != m1.owner &&
3340 asSuper(m2.owner.type, m1.owner) != null) {
3341 isMin_m1 = false;
3342 break;
3343 }
3344 }
3345 if (isMin_m1)
3346 methodsMin.append(m1);
3347 }
3348 return methodsMin.toList();
3349 }
3350 // where
3351 private class MethodFilter implements Predicate<Symbol> {
3352
3353 Symbol msym;
3354 Type site;
3355
3356 MethodFilter(Symbol msym, Type site) {
3357 this.msym = msym;
3358 this.site = site;
3359 }
3360
3361 @Override
3362 public boolean test(Symbol s) {
3363 return s.kind == MTH &&
3364 s.name == msym.name &&
3365 (s.flags() & SYNTHETIC) == 0 &&
3366 s.isInheritedIn(site.tsym, Types.this) &&
3367 overrideEquivalent(memberType(site, s), memberType(site, msym));
3368 }
3369 }
3370 // </editor-fold>
3371
3372 /**
3373 * Does t have the same arguments as s? It is assumed that both
3374 * types are (possibly polymorphic) method types. Monomorphic
3375 * method types "have the same arguments", if their argument lists
3376 * are equal. Polymorphic method types "have the same arguments",
3377 * if they have the same arguments after renaming all type
3378 * variables of one to corresponding type variables in the other,
3379 * where correspondence is by position in the type parameter list.
3380 */
3381 public boolean hasSameArgs(Type t, Type s) {
3382 return hasSameArgs(t, s, true);
3383 }
3384
3385 public boolean hasSameArgs(Type t, Type s, boolean strict) {
3386 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict);
3387 }
3388
3389 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) {
3390 return hasSameArgs.visit(t, s);
3391 }
3392 // where
3393 private class HasSameArgs extends TypeRelation {
3394
3395 boolean strict;
3396
3397 public HasSameArgs(boolean strict) {
3398 this.strict = strict;
3399 }
3400
3401 public Boolean visitType(Type t, Type s) {
3402 throw new AssertionError();
3403 }
3404
3405 @Override
3406 public Boolean visitMethodType(MethodType t, Type s) {
3407 return s.hasTag(METHOD)
3408 && containsTypeEquivalent(t.argtypes, s.getParameterTypes());
3409 }
3410
3411 @Override
3412 public Boolean visitForAll(ForAll t, Type s) {
3413 if (!s.hasTag(FORALL))
3414 return strict ? false : visitMethodType(t.asMethodType(), s);
3415
3416 ForAll forAll = (ForAll)s;
3417 return hasSameBounds(t, forAll)
3418 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
3419 }
3420
3421 @Override
3422 public Boolean visitErrorType(ErrorType t, Type s) {
3423 return false;
3424 }
3425 }
3426
3427 TypeRelation hasSameArgs_strict = new HasSameArgs(true);
3428 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false);
3429
3430 // </editor-fold>
3431
3432 // <editor-fold defaultstate="collapsed" desc="subst">
3433 public List<Type> subst(List<Type> ts,
3434 List<Type> from,
3435 List<Type> to) {
3436 return ts.map(new Subst(from, to));
3437 }
3438
3439 /**
3440 * Substitute all occurrences of a type in `from' with the
3441 * corresponding type in `to' in 't'. Match lists `from' and `to'
3442 * from the right: If lists have different length, discard leading
3443 * elements of the longer list.
3444 */
3445 public Type subst(Type t, List<Type> from, List<Type> to) {
3446 return t.map(new Subst(from, to));
3447 }
3448
3449 private class Subst extends StructuralTypeMapping<Void> {
3450 List<Type> from;
3451 List<Type> to;
3452
3453 public Subst(List<Type> from, List<Type> to) {
3454 int fromLength = from.length();
3455 int toLength = to.length();
3456 while (fromLength > toLength) {
3457 fromLength--;
3458 from = from.tail;
3459 }
3460 while (fromLength < toLength) {
3461 toLength--;
3462 to = to.tail;
3463 }
3464 this.from = from;
3465 this.to = to;
3466 }
3467
3468 @Override
3469 public Type visitTypeVar(TypeVar t, Void ignored) {
3470 for (List<Type> from = this.from, to = this.to;
3471 from.nonEmpty();
3472 from = from.tail, to = to.tail) {
3473 if (t.equalsIgnoreMetadata(from.head)) {
3474 return to.head.withTypeVar(t);
3475 }
3476 }
3477 return t;
3478 }
3479
3480 @Override
3481 public Type visitClassType(ClassType t, Void ignored) {
3482 if (!t.isCompound()) {
3483 return super.visitClassType(t, ignored);
3484 } else {
3485 Type st = visit(supertype(t));
3486 List<Type> is = visit(interfaces(t), ignored);
3487 if (st == supertype(t) && is == interfaces(t))
3488 return t;
3489 else
3490 return makeIntersectionType(is.prepend(st));
3491 }
3492 }
3493
3494 @Override
3495 public Type visitWildcardType(WildcardType t, Void ignored) {
3496 WildcardType t2 = (WildcardType)super.visitWildcardType(t, ignored);
3497 if (t2 != t && t.isExtendsBound() && t2.type.isExtendsBound()) {
3498 t2.type = wildUpperBound(t2.type);
3499 }
3500 return t2;
3501 }
3502
3503 @Override
3504 public Type visitForAll(ForAll t, Void ignored) {
3505 if (Type.containsAny(to, t.tvars)) {
3506 //perform alpha-renaming of free-variables in 't'
3507 //if 'to' types contain variables that are free in 't'
3508 List<Type> freevars = newInstances(t.tvars);
3509 t = new ForAll(freevars,
3510 Types.this.subst(t.qtype, t.tvars, freevars));
3511 }
3512 List<Type> tvars1 = substBounds(t.tvars, from, to);
3513 Type qtype1 = visit(t.qtype);
3514 if (tvars1 == t.tvars && qtype1 == t.qtype) {
3515 return t;
3516 } else if (tvars1 == t.tvars) {
3517 return new ForAll(tvars1, qtype1) {
3518 @Override
3519 public boolean needsStripping() {
3520 return true;
3521 }
3522 };
3523 } else {
3524 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1)) {
3525 @Override
3526 public boolean needsStripping() {
3527 return true;
3528 }
3529 };
3530 }
3531 }
3532 }
3533
3534 public List<Type> substBounds(List<Type> tvars,
3535 List<Type> from,
3536 List<Type> to) {
3537 if (tvars.isEmpty())
3538 return tvars;
3539 ListBuffer<Type> newBoundsBuf = new ListBuffer<>();
3540 boolean changed = false;
3541 // calculate new bounds
3542 for (Type t : tvars) {
3543 TypeVar tv = (TypeVar) t;
3544 Type bound = subst(tv.getUpperBound(), from, to);
3545 if (bound != tv.getUpperBound())
3546 changed = true;
3547 newBoundsBuf.append(bound);
3548 }
3549 if (!changed)
3550 return tvars;
3551 ListBuffer<Type> newTvars = new ListBuffer<>();
3552 // create new type variables without bounds
3553 for (Type t : tvars) {
3554 newTvars.append(new TypeVar(t.tsym, null, syms.botType,
3555 t.getMetadata()));
3556 }
3557 // the new bounds should use the new type variables in place
3558 // of the old
3559 List<Type> newBounds = newBoundsBuf.toList();
3560 from = tvars;
3561 to = newTvars.toList();
3562 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) {
3563 newBounds.head = subst(newBounds.head, from, to);
3564 }
3565 newBounds = newBoundsBuf.toList();
3566 // set the bounds of new type variables to the new bounds
3567 for (Type t : newTvars.toList()) {
3568 TypeVar tv = (TypeVar) t;
3569 tv.setUpperBound( newBounds.head );
3570 newBounds = newBounds.tail;
3571 }
3572 return newTvars.toList();
3573 }
3574
3575 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) {
3576 Type bound1 = subst(t.getUpperBound(), from, to);
3577 if (bound1 == t.getUpperBound())
3578 return t;
3579 else {
3580 // create new type variable without bounds
3581 TypeVar tv = new TypeVar(t.tsym, null, syms.botType,
3582 t.getMetadata());
3583 // the new bound should use the new type variable in place
3584 // of the old
3585 tv.setUpperBound( subst(bound1, List.of(t), List.of(tv)) );
3586 return tv;
3587 }
3588 }
3589 // </editor-fold>
3590
3591 // <editor-fold defaultstate="collapsed" desc="hasSameBounds">
3592 /**
3593 * Does t have the same bounds for quantified variables as s?
3594 */
3595 public boolean hasSameBounds(ForAll t, ForAll s) {
3596 List<Type> l1 = t.tvars;
3597 List<Type> l2 = s.tvars;
3598 while (l1.nonEmpty() && l2.nonEmpty() &&
3599 isSameType(l1.head.getUpperBound(),
3600 subst(l2.head.getUpperBound(),
3601 s.tvars,
3602 t.tvars))) {
3603 l1 = l1.tail;
3604 l2 = l2.tail;
3605 }
3606 return l1.isEmpty() && l2.isEmpty();
3607 }
3608 // </editor-fold>
3609
3610 // <editor-fold defaultstate="collapsed" desc="newInstances">
3611 /** Create new vector of type variables from list of variables
3612 * changing all recursive bounds from old to new list.
3613 */
3614 public List<Type> newInstances(List<Type> tvars) {
3615 List<Type> tvars1 = tvars.map(newInstanceFun);
3616 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) {
3617 TypeVar tv = (TypeVar) l.head;
3618 tv.setUpperBound( subst(tv.getUpperBound(), tvars, tvars1) );
3619 }
3620 return tvars1;
3621 }
3622 private static final TypeMapping<Void> newInstanceFun = new TypeMapping<Void>() {
3623 @Override
3624 public TypeVar visitTypeVar(TypeVar t, Void _unused) {
3625 return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound(), t.getMetadata());
3626 }
3627 };
3628 // </editor-fold>
3629
3630 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) {
3631 return original.accept(methodWithParameters, newParams);
3632 }
3633 // where
3634 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() {
3635 public Type visitType(Type t, List<Type> newParams) {
3636 throw new IllegalArgumentException("Not a method type: " + t);
3637 }
3638 public Type visitMethodType(MethodType t, List<Type> newParams) {
3639 return new MethodType(newParams, t.restype, t.thrown, t.tsym);
3640 }
3641 public Type visitForAll(ForAll t, List<Type> newParams) {
3642 return new ForAll(t.tvars, t.qtype.accept(this, newParams));
3643 }
3644 };
3645
3646 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) {
3647 return original.accept(methodWithThrown, newThrown);
3648 }
3649 // where
3650 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() {
3651 public Type visitType(Type t, List<Type> newThrown) {
3652 throw new IllegalArgumentException("Not a method type: " + t);
3653 }
3654 public Type visitMethodType(MethodType t, List<Type> newThrown) {
3655 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym);
3656 }
3657 public Type visitForAll(ForAll t, List<Type> newThrown) {
3658 return new ForAll(t.tvars, t.qtype.accept(this, newThrown));
3659 }
3660 };
3661
3662 public Type createMethodTypeWithReturn(Type original, Type newReturn) {
3663 return original.accept(methodWithReturn, newReturn);
3664 }
3665 // where
3666 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() {
3667 public Type visitType(Type t, Type newReturn) {
3668 throw new IllegalArgumentException("Not a method type: " + t);
3669 }
3670 public Type visitMethodType(MethodType t, Type newReturn) {
3671 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym) {
3672 @Override
3673 public Type baseType() {
3674 return t;
3675 }
3676 };
3677 }
3678 public Type visitForAll(ForAll t, Type newReturn) {
3679 return new ForAll(t.tvars, t.qtype.accept(this, newReturn)) {
3680 @Override
3681 public Type baseType() {
3682 return t;
3683 }
3684 };
3685 }
3686 };
3687
3688 // <editor-fold defaultstate="collapsed" desc="createErrorType">
3689 public Type createErrorType(Type originalType) {
3690 return new ErrorType(originalType, syms.errSymbol);
3691 }
3692
3693 public Type createErrorType(ClassSymbol c, Type originalType) {
3694 return new ErrorType(c, originalType);
3695 }
3696
3697 public Type createErrorType(Name name, TypeSymbol container, Type originalType) {
3698 return new ErrorType(name, container, originalType);
3699 }
3700 // </editor-fold>
3701
3702 // <editor-fold defaultstate="collapsed" desc="rank">
3703 /**
3704 * The rank of a class is the length of the longest path between
3705 * the class and java.lang.Object in the class inheritance
3706 * graph. Undefined for all but reference types.
3707 */
3708 public int rank(Type t) {
3709 switch(t.getTag()) {
3710 case CLASS: {
3711 ClassType cls = (ClassType)t;
3712 if (cls.rank_field < 0) {
3713 Name fullname = cls.tsym.getQualifiedName();
3714 if (fullname == names.java_lang_Object)
3715 cls.rank_field = 0;
3716 else {
3717 int r = rank(supertype(cls));
3718 for (List<Type> l = interfaces(cls);
3719 l.nonEmpty();
3720 l = l.tail) {
3721 if (rank(l.head) > r)
3722 r = rank(l.head);
3723 }
3724 cls.rank_field = r + 1;
3725 }
3726 }
3727 return cls.rank_field;
3728 }
3729 case TYPEVAR: {
3730 TypeVar tvar = (TypeVar)t;
3731 if (tvar.rank_field < 0) {
3732 int r = rank(supertype(tvar));
3733 for (List<Type> l = interfaces(tvar);
3734 l.nonEmpty();
3735 l = l.tail) {
3736 if (rank(l.head) > r) r = rank(l.head);
3737 }
3738 tvar.rank_field = r + 1;
3739 }
3740 return tvar.rank_field;
3741 }
3742 case ERROR:
3743 case NONE:
3744 return 0;
3745 default:
3746 throw new AssertionError();
3747 }
3748 }
3749 // </editor-fold>
3750
3751 /** Cache the symbol to reflect the qualifying type.
3752 * key: corresponding type
3753 * value: qualified symbol
3754 */
3755 private Map<Type, Symbol> qualifiedSymbolCache;
3756
3757 public void clearQualifiedSymbolCache() {
3758 qualifiedSymbolCache.clear();
3759 }
3760
3761 /** Construct a symbol to reflect the qualifying type that should
3762 * appear in the byte code as per JLS 13.1.
3763 *
3764 * For {@literal target >= 1.2}: Clone a method with the qualifier as owner (except
3765 * for those cases where we need to work around VM bugs).
3766 *
3767 * For {@literal target <= 1.1}: If qualified variable or method is defined in a
3768 * non-accessible class, clone it with the qualifier class as owner.
3769 *
3770 * @param sym The accessed symbol
3771 * @param site The qualifier's type.
3772 */
3773 public Symbol binaryQualifier(Symbol sym, Type site) {
3774
3775 if (site.hasTag(ARRAY)) {
3776 if (sym == syms.lengthVar ||
3777 sym.owner != syms.arrayClass)
3778 return sym;
3779 // array clone can be qualified by the array type in later targets
3780 Symbol qualifier;
3781 if ((qualifier = qualifiedSymbolCache.get(site)) == null) {
3782 qualifier = new ClassSymbol(Flags.PUBLIC, site.tsym.name, site, syms.noSymbol);
3783 qualifiedSymbolCache.put(site, qualifier);
3784 }
3785 return sym.clone(qualifier);
3786 }
3787
3788 if (sym.owner == site.tsym ||
3789 (sym.flags() & (STATIC | SYNTHETIC)) == (STATIC | SYNTHETIC)) {
3790 return sym;
3791 }
3792
3793 // leave alone methods inherited from Object
3794 // JLS 13.1.
3795 if (sym.owner == syms.objectType.tsym)
3796 return sym;
3797
3798 return sym.clone(site.tsym);
3799 }
3800
3801 /**
3802 * Helper method for generating a string representation of a given type
3803 * accordingly to a given locale
3804 */
3805 public String toString(Type t, Locale locale) {
3806 return Printer.createStandardPrinter(messages).visit(t, locale);
3807 }
3808
3809 /**
3810 * Helper method for generating a string representation of a given type
3811 * accordingly to a given locale
3812 */
3813 public String toString(Symbol t, Locale locale) {
3814 return Printer.createStandardPrinter(messages).visit(t, locale);
3815 }
3816
3817 // <editor-fold defaultstate="collapsed" desc="toString">
3818 /**
3819 * This toString is slightly more descriptive than the one on Type.
3820 *
3821 * @deprecated Types.toString(Type t, Locale l) provides better support
3822 * for localization
3823 */
3824 @Deprecated
3825 public String toString(Type t) {
3826 if (t.hasTag(FORALL)) {
3827 ForAll forAll = (ForAll)t;
3828 return typaramsString(forAll.tvars) + forAll.qtype;
3829 }
3830 return "" + t;
3831 }
3832 // where
3833 private String typaramsString(List<Type> tvars) {
3834 StringBuilder s = new StringBuilder();
3835 s.append('<');
3836 boolean first = true;
3837 for (Type t : tvars) {
3838 if (!first) s.append(", ");
3839 first = false;
3840 appendTyparamString(((TypeVar)t), s);
3841 }
3842 s.append('>');
3843 return s.toString();
3844 }
3845 private void appendTyparamString(TypeVar t, StringBuilder buf) {
3846 buf.append(t);
3847 if (t.getUpperBound() == null ||
3848 t.getUpperBound().tsym.getQualifiedName() == names.java_lang_Object)
3849 return;
3850 buf.append(" extends "); // Java syntax; no need for i18n
3851 Type bound = t.getUpperBound();
3852 if (!bound.isCompound()) {
3853 buf.append(bound);
3854 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) {
3855 buf.append(supertype(t));
3856 for (Type intf : interfaces(t)) {
3857 buf.append('&');
3858 buf.append(intf);
3859 }
3860 } else {
3861 // No superclass was given in bounds.
3862 // In this case, supertype is Object, erasure is first interface.
3863 boolean first = true;
3864 for (Type intf : interfaces(t)) {
3865 if (!first) buf.append('&');
3866 first = false;
3867 buf.append(intf);
3868 }
3869 }
3870 }
3871 // </editor-fold>
3872
3873 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types">
3874 /**
3875 * A cache for closures.
3876 *
3877 * <p>A closure is a list of all the supertypes and interfaces of
3878 * a class or interface type, ordered by ClassSymbol.precedes
3879 * (that is, subclasses come first, arbitrary but fixed
3880 * otherwise).
3881 */
3882 private Map<Type,List<Type>> closureCache = new HashMap<>();
3883
3884 /**
3885 * Returns the closure of a class or interface type.
3886 */
3887 public List<Type> closure(Type t) {
3888 List<Type> cl = closureCache.get(t);
3889 if (cl == null) {
3890 Type st = supertype(t);
3891 if (!t.isCompound()) {
3892 if (st.hasTag(CLASS)) {
3893 cl = insert(closure(st), t);
3894 } else if (st.hasTag(TYPEVAR)) {
3895 cl = closure(st).prepend(t);
3896 } else {
3897 cl = List.of(t);
3898 }
3899 } else {
3900 cl = closure(supertype(t));
3901 }
3902 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail)
3903 cl = union(cl, closure(l.head));
3904 closureCache.put(t, cl);
3905 }
3906 return cl;
3907 }
3908
3909 /**
3910 * Collect types into a new closure (using a @code{ClosureHolder})
3911 */
3912 public Collector<Type, ClosureHolder, List<Type>> closureCollector(boolean minClosure, BiPredicate<Type, Type> shouldSkip) {
3913 return Collector.of(() -> new ClosureHolder(minClosure, shouldSkip),
3914 ClosureHolder::add,
3915 ClosureHolder::merge,
3916 ClosureHolder::closure);
3917 }
3918 //where
3919 class ClosureHolder {
3920 List<Type> closure;
3921 final boolean minClosure;
3922 final BiPredicate<Type, Type> shouldSkip;
3923
3924 ClosureHolder(boolean minClosure, BiPredicate<Type, Type> shouldSkip) {
3925 this.closure = List.nil();
3926 this.minClosure = minClosure;
3927 this.shouldSkip = shouldSkip;
3928 }
3929
3930 void add(Type type) {
3931 closure = insert(closure, type, shouldSkip);
3932 }
3933
3934 ClosureHolder merge(ClosureHolder other) {
3935 closure = union(closure, other.closure, shouldSkip);
3936 return this;
3937 }
3938
3939 List<Type> closure() {
3940 return minClosure ? closureMin(closure) : closure;
3941 }
3942 }
3943
3944 BiPredicate<Type, Type> basicClosureSkip = (t1, t2) -> t1.tsym == t2.tsym;
3945
3946 /**
3947 * Insert a type in a closure
3948 */
3949 public List<Type> insert(List<Type> cl, Type t, BiPredicate<Type, Type> shouldSkip) {
3950 if (cl.isEmpty()) {
3951 return cl.prepend(t);
3952 } else if (shouldSkip.test(t, cl.head)) {
3953 return cl;
3954 } else if (t.tsym.precedes(cl.head.tsym, this)) {
3955 return cl.prepend(t);
3956 } else {
3957 // t comes after head, or the two are unrelated
3958 return insert(cl.tail, t, shouldSkip).prepend(cl.head);
3959 }
3960 }
3961
3962 public List<Type> insert(List<Type> cl, Type t) {
3963 return insert(cl, t, basicClosureSkip);
3964 }
3965
3966 /**
3967 * Form the union of two closures
3968 */
3969 public List<Type> union(List<Type> cl1, List<Type> cl2, BiPredicate<Type, Type> shouldSkip) {
3970 if (cl1.isEmpty()) {
3971 return cl2;
3972 } else if (cl2.isEmpty()) {
3973 return cl1;
3974 } else if (shouldSkip.test(cl1.head, cl2.head)) {
3975 return union(cl1.tail, cl2.tail, shouldSkip).prepend(cl1.head);
3976 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) {
3977 return union(cl1, cl2.tail, shouldSkip).prepend(cl2.head);
3978 } else {
3979 return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head);
3980 }
3981 }
3982
3983 public List<Type> union(List<Type> cl1, List<Type> cl2) {
3984 return union(cl1, cl2, basicClosureSkip);
3985 }
3986
3987 /**
3988 * Intersect two closures
3989 */
3990 public List<Type> intersect(List<Type> cl1, List<Type> cl2) {
3991 if (cl1 == cl2)
3992 return cl1;
3993 if (cl1.isEmpty() || cl2.isEmpty())
3994 return List.nil();
3995 if (cl1.head.tsym.precedes(cl2.head.tsym, this))
3996 return intersect(cl1.tail, cl2);
3997 if (cl2.head.tsym.precedes(cl1.head.tsym, this))
3998 return intersect(cl1, cl2.tail);
3999 if (isSameType(cl1.head, cl2.head))
4000 return intersect(cl1.tail, cl2.tail).prepend(cl1.head);
4001 if (cl1.head.tsym == cl2.head.tsym &&
4002 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) {
4003 if (cl1.head.isParameterized() && cl2.head.isParameterized()) {
4004 Type merge = merge(cl1.head,cl2.head);
4005 return intersect(cl1.tail, cl2.tail).prepend(merge);
4006 }
4007 if (cl1.head.isRaw() || cl2.head.isRaw())
4008 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head));
4009 }
4010 return intersect(cl1.tail, cl2.tail);
4011 }
4012 // where
4013 class TypePair {
4014 final Type t1;
4015 final Type t2;;
4016
4017 TypePair(Type t1, Type t2) {
4018 this.t1 = t1;
4019 this.t2 = t2;
4020 }
4021 @Override
4022 public int hashCode() {
4023 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2);
4024 }
4025 @Override
4026 public boolean equals(Object obj) {
4027 return (obj instanceof TypePair typePair)
4028 && isSameType(t1, typePair.t1)
4029 && isSameType(t2, typePair.t2);
4030 }
4031 }
4032 Set<TypePair> mergeCache = new HashSet<>();
4033 private Type merge(Type c1, Type c2) {
4034 ClassType class1 = (ClassType) c1;
4035 List<Type> act1 = class1.getTypeArguments();
4036 ClassType class2 = (ClassType) c2;
4037 List<Type> act2 = class2.getTypeArguments();
4038 ListBuffer<Type> merged = new ListBuffer<>();
4039 List<Type> typarams = class1.tsym.type.getTypeArguments();
4040
4041 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) {
4042 if (containsType(act1.head, act2.head)) {
4043 merged.append(act1.head);
4044 } else if (containsType(act2.head, act1.head)) {
4045 merged.append(act2.head);
4046 } else {
4047 TypePair pair = new TypePair(c1, c2);
4048 Type m;
4049 if (mergeCache.add(pair)) {
4050 m = new WildcardType(lub(wildUpperBound(act1.head),
4051 wildUpperBound(act2.head)),
4052 BoundKind.EXTENDS,
4053 syms.boundClass);
4054 mergeCache.remove(pair);
4055 } else {
4056 m = new WildcardType(syms.objectType,
4057 BoundKind.UNBOUND,
4058 syms.boundClass);
4059 }
4060 merged.append(m.withTypeVar(typarams.head));
4061 }
4062 act1 = act1.tail;
4063 act2 = act2.tail;
4064 typarams = typarams.tail;
4065 }
4066 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty());
4067 // There is no spec detailing how type annotations are to
4068 // be inherited. So set it to noAnnotations for now
4069 return new ClassType(class1.getEnclosingType(), merged.toList(),
4070 class1.tsym, TypeMetadata.EMPTY, class1.getFlavor());
4071 }
4072
4073 /**
4074 * Return the minimum type of a closure, a compound type if no
4075 * unique minimum exists.
4076 */
4077 private Type compoundMin(List<Type> cl) {
4078 if (cl.isEmpty()) return syms.objectType;
4079 List<Type> compound = closureMin(cl);
4080 if (compound.isEmpty())
4081 return null;
4082 else if (compound.tail.isEmpty())
4083 return compound.head;
4084 else
4085 return makeIntersectionType(compound);
4086 }
4087
4088 /**
4089 * Return the minimum types of a closure, suitable for computing
4090 * compoundMin or glb.
4091 */
4092 private List<Type> closureMin(List<Type> cl) {
4093 ListBuffer<Type> classes = new ListBuffer<>();
4094 ListBuffer<Type> interfaces = new ListBuffer<>();
4095 Set<Type> toSkip = new HashSet<>();
4096 while (!cl.isEmpty()) {
4097 Type current = cl.head;
4098 boolean keep = !toSkip.contains(current);
4099 if (keep && current.hasTag(TYPEVAR)) {
4100 // skip lower-bounded variables with a subtype in cl.tail
4101 for (Type t : cl.tail) {
4102 if (isSubtypeNoCapture(t, current)) {
4103 keep = false;
4104 break;
4105 }
4106 }
4107 }
4108 if (keep) {
4109 if (current.isInterface())
4110 interfaces.append(current);
4111 else
4112 classes.append(current);
4113 for (Type t : cl.tail) {
4114 // skip supertypes of 'current' in cl.tail
4115 if (isSubtypeNoCapture(current, t))
4116 toSkip.add(t);
4117 }
4118 }
4119 cl = cl.tail;
4120 }
4121 return classes.appendList(interfaces).toList();
4122 }
4123
4124 /**
4125 * Return the least upper bound of list of types. if the lub does
4126 * not exist return null.
4127 */
4128 public Type lub(List<Type> ts) {
4129 return lub(ts.toArray(new Type[ts.length()]));
4130 }
4131
4132 /**
4133 * Return the least upper bound (lub) of set of types. If the lub
4134 * does not exist return the type of null (bottom).
4135 */
4136 public Type lub(Type... ts) {
4137 final int UNKNOWN_BOUND = 0;
4138 final int ARRAY_BOUND = 1;
4139 final int CLASS_BOUND = 2;
4140
4141 int[] kinds = new int[ts.length];
4142
4143 int boundkind = UNKNOWN_BOUND;
4144 for (int i = 0 ; i < ts.length ; i++) {
4145 Type t = ts[i];
4146 switch (t.getTag()) {
4147 case CLASS:
4148 boundkind |= kinds[i] = CLASS_BOUND;
4149 break;
4150 case ARRAY:
4151 boundkind |= kinds[i] = ARRAY_BOUND;
4152 break;
4153 case TYPEVAR:
4154 do {
4155 t = t.getUpperBound();
4156 } while (t.hasTag(TYPEVAR));
4157 if (t.hasTag(ARRAY)) {
4158 boundkind |= kinds[i] = ARRAY_BOUND;
4159 } else {
4160 boundkind |= kinds[i] = CLASS_BOUND;
4161 }
4162 break;
4163 default:
4164 kinds[i] = UNKNOWN_BOUND;
4165 if (t.isPrimitive())
4166 return syms.errType;
4167 }
4168 }
4169 switch (boundkind) {
4170 case 0:
4171 return syms.botType;
4172
4173 case ARRAY_BOUND:
4174 // calculate lub(A[], B[])
4175 Type[] elements = new Type[ts.length];
4176 for (int i = 0 ; i < ts.length ; i++) {
4177 Type elem = elements[i] = elemTypeFun.apply(ts[i]);
4178 if (elem.isPrimitive()) {
4179 // if a primitive type is found, then return
4180 // arraySuperType unless all the types are the
4181 // same
4182 Type first = ts[0];
4183 for (int j = 1 ; j < ts.length ; j++) {
4184 if (!isSameType(first, ts[j])) {
4185 // lub(int[], B[]) is Cloneable & Serializable
4186 return arraySuperType();
4187 }
4188 }
4189 // all the array types are the same, return one
4190 // lub(int[], int[]) is int[]
4191 return first;
4192 }
4193 }
4194 // lub(A[], B[]) is lub(A, B)[]
4195 return new ArrayType(lub(elements), syms.arrayClass);
4196
4197 case CLASS_BOUND:
4198 // calculate lub(A, B)
4199 int startIdx = 0;
4200 for (int i = 0; i < ts.length ; i++) {
4201 Type t = ts[i];
4202 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) {
4203 break;
4204 } else {
4205 startIdx++;
4206 }
4207 }
4208 Assert.check(startIdx < ts.length);
4209 //step 1 - compute erased candidate set (EC)
4210 List<Type> cl = erasedSupertypes(ts[startIdx]);
4211 for (int i = startIdx + 1 ; i < ts.length ; i++) {
4212 Type t = ts[i];
4213 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR))
4214 cl = intersect(cl, erasedSupertypes(t));
4215 }
4216 //step 2 - compute minimal erased candidate set (MEC)
4217 List<Type> mec = closureMin(cl);
4218 //step 3 - for each element G in MEC, compute lci(Inv(G))
4219 List<Type> candidates = List.nil();
4220 for (Type erasedSupertype : mec) {
4221 List<Type> lci = List.of(asSuper(ts[startIdx], erasedSupertype.tsym));
4222 for (int i = startIdx + 1 ; i < ts.length ; i++) {
4223 Type superType = asSuper(ts[i], erasedSupertype.tsym);
4224 lci = intersect(lci, superType != null ? List.of(superType) : List.nil());
4225 }
4226 candidates = candidates.appendList(lci);
4227 }
4228 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that
4229 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn))
4230 return compoundMin(candidates);
4231
4232 default:
4233 // calculate lub(A, B[])
4234 List<Type> classes = List.of(arraySuperType());
4235 for (int i = 0 ; i < ts.length ; i++) {
4236 if (kinds[i] != ARRAY_BOUND) // Filter out any arrays
4237 classes = classes.prepend(ts[i]);
4238 }
4239 // lub(A, B[]) is lub(A, arraySuperType)
4240 return lub(classes);
4241 }
4242 }
4243 // where
4244 List<Type> erasedSupertypes(Type t) {
4245 ListBuffer<Type> buf = new ListBuffer<>();
4246 for (Type sup : closure(t)) {
4247 if (sup.hasTag(TYPEVAR)) {
4248 buf.append(sup);
4249 } else {
4250 buf.append(erasure(sup));
4251 }
4252 }
4253 return buf.toList();
4254 }
4255
4256 private Type arraySuperType;
4257 private Type arraySuperType() {
4258 // initialized lazily to avoid problems during compiler startup
4259 if (arraySuperType == null) {
4260 // JLS 10.8: all arrays implement Cloneable and Serializable.
4261 arraySuperType = makeIntersectionType(List.of(syms.serializableType,
4262 syms.cloneableType), true);
4263 }
4264 return arraySuperType;
4265 }
4266 // </editor-fold>
4267
4268 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound">
4269 public Type glb(List<Type> ts) {
4270 Type t1 = ts.head;
4271 for (Type t2 : ts.tail) {
4272 if (t1.isErroneous())
4273 return t1;
4274 t1 = glb(t1, t2);
4275 }
4276 return t1;
4277 }
4278 //where
4279 public Type glb(Type t, Type s) {
4280 if (s == null)
4281 return t;
4282 else if (t.isPrimitive() || s.isPrimitive())
4283 return syms.errType;
4284 else if (isSubtypeNoCapture(t, s))
4285 return t;
4286 else if (isSubtypeNoCapture(s, t))
4287 return s;
4288
4289 List<Type> closure = union(closure(t), closure(s));
4290 return glbFlattened(closure, t);
4291 }
4292 //where
4293 /**
4294 * Perform glb for a list of non-primitive, non-error, non-compound types;
4295 * redundant elements are removed. Bounds should be ordered according to
4296 * {@link Symbol#precedes(TypeSymbol,Types)}.
4297 *
4298 * @param flatBounds List of type to glb
4299 * @param errT Original type to use if the result is an error type
4300 */
4301 private Type glbFlattened(List<Type> flatBounds, Type errT) {
4302 List<Type> bounds = closureMin(flatBounds);
4303
4304 if (bounds.isEmpty()) { // length == 0
4305 return syms.objectType;
4306 } else if (bounds.tail.isEmpty()) { // length == 1
4307 return bounds.head;
4308 } else { // length > 1
4309 int classCount = 0;
4310 List<Type> cvars = List.nil();
4311 List<Type> lowers = List.nil();
4312 for (Type bound : bounds) {
4313 if (!bound.isInterface()) {
4314 classCount++;
4315 Type lower = cvarLowerBound(bound);
4316 if (bound != lower && !lower.hasTag(BOT)) {
4317 cvars = cvars.append(bound);
4318 lowers = lowers.append(lower);
4319 }
4320 }
4321 }
4322 if (classCount > 1) {
4323 if (lowers.isEmpty()) {
4324 return createErrorType(errT);
4325 } else {
4326 // try again with lower bounds included instead of capture variables
4327 List<Type> newBounds = bounds.diff(cvars).appendList(lowers);
4328 return glb(newBounds);
4329 }
4330 }
4331 }
4332 return makeIntersectionType(bounds);
4333 }
4334 // </editor-fold>
4335
4336 // <editor-fold defaultstate="collapsed" desc="hashCode">
4337 /**
4338 * Compute a hash code on a type.
4339 */
4340 public int hashCode(Type t) {
4341 return hashCode(t, false);
4342 }
4343
4344 public int hashCode(Type t, boolean strict) {
4345 return strict ?
4346 hashCodeStrictVisitor.visit(t) :
4347 hashCodeVisitor.visit(t);
4348 }
4349 // where
4350 private static final HashCodeVisitor hashCodeVisitor = new HashCodeVisitor();
4351 private static final HashCodeVisitor hashCodeStrictVisitor = new HashCodeVisitor() {
4352 @Override
4353 public Integer visitTypeVar(TypeVar t, Void ignored) {
4354 return System.identityHashCode(t);
4355 }
4356 };
4357
4358 private static class HashCodeVisitor extends UnaryVisitor<Integer> {
4359 public Integer visitType(Type t, Void ignored) {
4360 return t.getTag().ordinal();
4361 }
4362
4363 @Override
4364 public Integer visitClassType(ClassType t, Void ignored) {
4365 int result = visit(t.getEnclosingType());
4366 result *= 127;
4367 result += t.tsym.flatName().hashCode();
4368 for (Type s : t.getTypeArguments()) {
4369 result *= 127;
4370 result += visit(s);
4371 }
4372 return result;
4373 }
4374
4375 @Override
4376 public Integer visitMethodType(MethodType t, Void ignored) {
4377 int h = METHOD.ordinal();
4378 for (List<Type> thisargs = t.argtypes;
4379 thisargs.tail != null;
4380 thisargs = thisargs.tail)
4381 h = (h << 5) + visit(thisargs.head);
4382 return (h << 5) + visit(t.restype);
4383 }
4384
4385 @Override
4386 public Integer visitWildcardType(WildcardType t, Void ignored) {
4387 int result = t.kind.hashCode();
4388 if (t.type != null) {
4389 result *= 127;
4390 result += visit(t.type);
4391 }
4392 return result;
4393 }
4394
4395 @Override
4396 public Integer visitArrayType(ArrayType t, Void ignored) {
4397 return visit(t.elemtype) + 12;
4398 }
4399
4400 @Override
4401 public Integer visitTypeVar(TypeVar t, Void ignored) {
4402 return System.identityHashCode(t);
4403 }
4404
4405 @Override
4406 public Integer visitUndetVar(UndetVar t, Void ignored) {
4407 return System.identityHashCode(t);
4408 }
4409
4410 @Override
4411 public Integer visitErrorType(ErrorType t, Void ignored) {
4412 return 0;
4413 }
4414 }
4415 // </editor-fold>
4416
4417 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable">
4418 /**
4419 * Does t have a result that is a subtype of the result type of s,
4420 * suitable for covariant returns? It is assumed that both types
4421 * are (possibly polymorphic) method types. Monomorphic method
4422 * types are handled in the obvious way. Polymorphic method types
4423 * require renaming all type variables of one to corresponding
4424 * type variables in the other, where correspondence is by
4425 * position in the type parameter list. */
4426 public boolean resultSubtype(Type t, Type s, Warner warner) {
4427 List<Type> tvars = t.getTypeArguments();
4428 List<Type> svars = s.getTypeArguments();
4429 Type tres = t.getReturnType();
4430 Type sres = subst(s.getReturnType(), svars, tvars);
4431 return covariantReturnType(tres, sres, warner);
4432 }
4433
4434 /**
4435 * Return-Type-Substitutable.
4436 * @jls 8.4.5 Method Result
4437 */
4438 public boolean returnTypeSubstitutable(Type r1, Type r2) {
4439 if (hasSameArgs(r1, r2))
4440 return resultSubtype(r1, r2, noWarnings);
4441 else
4442 return covariantReturnType(r1.getReturnType(),
4443 erasure(r2.getReturnType()),
4444 noWarnings);
4445 }
4446
4447 public boolean returnTypeSubstitutable(Type r1,
4448 Type r2, Type r2res,
4449 Warner warner) {
4450 if (isSameType(r1.getReturnType(), r2res))
4451 return true;
4452 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive())
4453 return false;
4454
4455 if (hasSameArgs(r1, r2))
4456 return covariantReturnType(r1.getReturnType(), r2res, warner);
4457 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner))
4458 return true;
4459 if (!isSubtype(r1.getReturnType(), erasure(r2res)))
4460 return false;
4461 warner.warn(LintCategory.UNCHECKED);
4462 return true;
4463 }
4464
4465 /**
4466 * Is t an appropriate return type in an overrider for a
4467 * method that returns s?
4468 */
4469 public boolean covariantReturnType(Type t, Type s, Warner warner) {
4470 return
4471 isSameType(t, s) ||
4472 !t.isPrimitive() &&
4473 !s.isPrimitive() &&
4474 isAssignable(t, s, warner);
4475 }
4476 // </editor-fold>
4477
4478 // <editor-fold defaultstate="collapsed" desc="Box/unbox support">
4479 /**
4480 * Return the class that boxes the given primitive.
4481 */
4482 public ClassSymbol boxedClass(Type t) {
4483 return syms.enterClass(syms.java_base, syms.boxedName[t.getTag().ordinal()]);
4484 }
4485
4486 /**
4487 * Return the boxed type if 't' is primitive, otherwise return 't' itself.
4488 */
4489 public Type boxedTypeOrType(Type t) {
4490 return t.isPrimitive() ?
4491 boxedClass(t).type :
4492 t;
4493 }
4494
4495 /**
4496 * Return the primitive type corresponding to a boxed type.
4497 */
4498 public Type unboxedType(Type t) {
4499 if (t.hasTag(ERROR))
4500 return Type.noType;
4501 for (int i=0; i<syms.boxedName.length; i++) {
4502 Name box = syms.boxedName[i];
4503 if (box != null &&
4504 asSuper(t, syms.enterClass(syms.java_base, box)) != null)
4505 return syms.typeOfTag[i];
4506 }
4507 return Type.noType;
4508 }
4509
4510 /**
4511 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself.
4512 */
4513 public Type unboxedTypeOrType(Type t) {
4514 Type unboxedType = unboxedType(t);
4515 return unboxedType.hasTag(NONE) ? t : unboxedType;
4516 }
4517 // </editor-fold>
4518
4519 // <editor-fold defaultstate="collapsed" desc="Capture conversion">
4520 /*
4521 * JLS 5.1.10 Capture Conversion:
4522 *
4523 * Let G name a generic type declaration with n formal type
4524 * parameters A1 ... An with corresponding bounds U1 ... Un. There
4525 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>,
4526 * where, for 1 <= i <= n:
4527 *
4528 * + If Ti is a wildcard type argument (4.5.1) of the form ? then
4529 * Si is a fresh type variable whose upper bound is
4530 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null
4531 * type.
4532 *
4533 * + If Ti is a wildcard type argument of the form ? extends Bi,
4534 * then Si is a fresh type variable whose upper bound is
4535 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is
4536 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is
4537 * a compile-time error if for any two classes (not interfaces)
4538 * Vi and Vj,Vi is not a subclass of Vj or vice versa.
4539 *
4540 * + If Ti is a wildcard type argument of the form ? super Bi,
4541 * then Si is a fresh type variable whose upper bound is
4542 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi.
4543 *
4544 * + Otherwise, Si = Ti.
4545 *
4546 * Capture conversion on any type other than a parameterized type
4547 * (4.5) acts as an identity conversion (5.1.1). Capture
4548 * conversions never require a special action at run time and
4549 * therefore never throw an exception at run time.
4550 *
4551 * Capture conversion is not applied recursively.
4552 */
4553 /**
4554 * Capture conversion as specified by the JLS.
4555 */
4556
4557 public List<Type> capture(List<Type> ts) {
4558 List<Type> buf = List.nil();
4559 for (Type t : ts) {
4560 buf = buf.prepend(capture(t));
4561 }
4562 return buf.reverse();
4563 }
4564
4565 public Type capture(Type t) {
4566 if (!t.hasTag(CLASS)) {
4567 return t;
4568 }
4569 if (t.getEnclosingType() != Type.noType) {
4570 Type capturedEncl = capture(t.getEnclosingType());
4571 if (capturedEncl != t.getEnclosingType()) {
4572 Type type1 = memberType(capturedEncl, t.tsym);
4573 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments());
4574 }
4575 }
4576 ClassType cls = (ClassType)t;
4577 if (cls.isRaw() || !cls.isParameterized())
4578 return cls;
4579
4580 ClassType G = (ClassType)cls.asElement().asType();
4581 List<Type> A = G.getTypeArguments();
4582 List<Type> T = cls.getTypeArguments();
4583 List<Type> S = freshTypeVariables(T);
4584
4585 List<Type> currentA = A;
4586 List<Type> currentT = T;
4587 List<Type> currentS = S;
4588 boolean captured = false;
4589 while (!currentA.isEmpty() &&
4590 !currentT.isEmpty() &&
4591 !currentS.isEmpty()) {
4592 if (currentS.head != currentT.head) {
4593 captured = true;
4594 WildcardType Ti = (WildcardType)currentT.head;
4595 Type Ui = currentA.head.getUpperBound();
4596 CapturedType Si = (CapturedType)currentS.head;
4597 if (Ui == null)
4598 Ui = syms.objectType;
4599 switch (Ti.kind) {
4600 case UNBOUND:
4601 Si.setUpperBound( subst(Ui, A, S) );
4602 Si.lower = syms.botType;
4603 break;
4604 case EXTENDS:
4605 Si.setUpperBound( glb(Ti.getExtendsBound(), subst(Ui, A, S)) );
4606 Si.lower = syms.botType;
4607 break;
4608 case SUPER:
4609 Si.setUpperBound( subst(Ui, A, S) );
4610 Si.lower = Ti.getSuperBound();
4611 break;
4612 }
4613 Type tmpBound = Si.getUpperBound().hasTag(UNDETVAR) ? ((UndetVar)Si.getUpperBound()).qtype : Si.getUpperBound();
4614 Type tmpLower = Si.lower.hasTag(UNDETVAR) ? ((UndetVar)Si.lower).qtype : Si.lower;
4615 if (!Si.getUpperBound().hasTag(ERROR) &&
4616 !Si.lower.hasTag(ERROR) &&
4617 isSameType(tmpBound, tmpLower)) {
4618 currentS.head = Si.getUpperBound();
4619 }
4620 }
4621 currentA = currentA.tail;
4622 currentT = currentT.tail;
4623 currentS = currentS.tail;
4624 }
4625 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty())
4626 return erasure(t); // some "rare" type involved
4627
4628 if (captured)
4629 return new ClassType(cls.getEnclosingType(), S, cls.tsym,
4630 cls.getMetadata(), cls.getFlavor());
4631 else
4632 return t;
4633 }
4634 // where
4635 public List<Type> freshTypeVariables(List<Type> types) {
4636 ListBuffer<Type> result = new ListBuffer<>();
4637 for (Type t : types) {
4638 if (t.hasTag(WILDCARD)) {
4639 Type bound = ((WildcardType)t).getExtendsBound();
4640 if (bound == null)
4641 bound = syms.objectType;
4642 result.append(new CapturedType(capturedName,
4643 syms.noSymbol,
4644 bound,
4645 syms.botType,
4646 (WildcardType)t));
4647 } else {
4648 result.append(t);
4649 }
4650 }
4651 return result.toList();
4652 }
4653 // </editor-fold>
4654
4655 // <editor-fold defaultstate="collapsed" desc="Internal utility methods">
4656 private boolean sideCast(Type from, Type to, Warner warn) {
4657 // We are casting from type $from$ to type $to$, which are
4658 // non-final unrelated types. This method
4659 // tries to reject a cast by transferring type parameters
4660 // from $to$ to $from$ by common superinterfaces.
4661 boolean reverse = false;
4662 Type target = to;
4663 if ((to.tsym.flags() & INTERFACE) == 0) {
4664 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4665 reverse = true;
4666 to = from;
4667 from = target;
4668 }
4669 List<Type> commonSupers = superClosure(to, erasure(from));
4670 boolean giveWarning = commonSupers.isEmpty();
4671 // The arguments to the supers could be unified here to
4672 // get a more accurate analysis
4673 while (commonSupers.nonEmpty()) {
4674 Type t1 = asSuper(from, commonSupers.head.tsym);
4675 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym);
4676 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4677 return false;
4678 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2));
4679 commonSupers = commonSupers.tail;
4680 }
4681 if (giveWarning && !isReifiable(reverse ? from : to))
4682 warn.warn(LintCategory.UNCHECKED);
4683 return true;
4684 }
4685
4686 private boolean sideCastFinal(Type from, Type to, Warner warn) {
4687 // We are casting from type $from$ to type $to$, which are
4688 // unrelated types one of which is final and the other of
4689 // which is an interface. This method
4690 // tries to reject a cast by transferring type parameters
4691 // from the final class to the interface.
4692 boolean reverse = false;
4693 Type target = to;
4694 if ((to.tsym.flags() & INTERFACE) == 0) {
4695 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4696 reverse = true;
4697 to = from;
4698 from = target;
4699 }
4700 Assert.check((from.tsym.flags() & FINAL) != 0);
4701 Type t1 = asSuper(from, to.tsym);
4702 if (t1 == null) return false;
4703 Type t2 = to;
4704 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4705 return false;
4706 if (!isReifiable(target) &&
4707 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)))
4708 warn.warn(LintCategory.UNCHECKED);
4709 return true;
4710 }
4711
4712 private boolean giveWarning(Type from, Type to) {
4713 List<Type> bounds = to.isCompound() ?
4714 directSupertypes(to) : List.of(to);
4715 for (Type b : bounds) {
4716 Type subFrom = asSub(from, b.tsym);
4717 if (b.isParameterized() &&
4718 (!(isUnbounded(b) ||
4719 isSubtype(from, b) ||
4720 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) {
4721 return true;
4722 }
4723 }
4724 return false;
4725 }
4726
4727 private List<Type> superClosure(Type t, Type s) {
4728 List<Type> cl = List.nil();
4729 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
4730 if (isSubtype(s, erasure(l.head))) {
4731 cl = insert(cl, l.head);
4732 } else {
4733 cl = union(cl, superClosure(l.head, s));
4734 }
4735 }
4736 return cl;
4737 }
4738
4739 private boolean containsTypeEquivalent(Type t, Type s) {
4740 return isSameType(t, s) || // shortcut
4741 containsType(t, s) && containsType(s, t);
4742 }
4743
4744 // <editor-fold defaultstate="collapsed" desc="adapt">
4745 /**
4746 * Adapt a type by computing a substitution which maps a source
4747 * type to a target type.
4748 *
4749 * @param source the source type
4750 * @param target the target type
4751 * @param from the type variables of the computed substitution
4752 * @param to the types of the computed substitution.
4753 */
4754 public void adapt(Type source,
4755 Type target,
4756 ListBuffer<Type> from,
4757 ListBuffer<Type> to) throws AdaptFailure {
4758 new Adapter(from, to).adapt(source, target);
4759 }
4760
4761 class Adapter extends SimpleVisitor<Void, Type> {
4762
4763 ListBuffer<Type> from;
4764 ListBuffer<Type> to;
4765 Map<Symbol,Type> mapping;
4766
4767 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) {
4768 this.from = from;
4769 this.to = to;
4770 mapping = new HashMap<>();
4771 }
4772
4773 public void adapt(Type source, Type target) throws AdaptFailure {
4774 visit(source, target);
4775 List<Type> fromList = from.toList();
4776 List<Type> toList = to.toList();
4777 while (!fromList.isEmpty()) {
4778 Type val = mapping.get(fromList.head.tsym);
4779 if (toList.head != val)
4780 toList.head = val;
4781 fromList = fromList.tail;
4782 toList = toList.tail;
4783 }
4784 }
4785
4786 @Override
4787 public Void visitClassType(ClassType source, Type target) throws AdaptFailure {
4788 if (target.hasTag(CLASS))
4789 adaptRecursive(source.allparams(), target.allparams());
4790 return null;
4791 }
4792
4793 @Override
4794 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure {
4795 if (target.hasTag(ARRAY))
4796 adaptRecursive(elemtype(source), elemtype(target));
4797 return null;
4798 }
4799
4800 @Override
4801 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure {
4802 if (source.isExtendsBound())
4803 adaptRecursive(wildUpperBound(source), wildUpperBound(target));
4804 else if (source.isSuperBound())
4805 adaptRecursive(wildLowerBound(source), wildLowerBound(target));
4806 return null;
4807 }
4808
4809 @Override
4810 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure {
4811 // Check to see if there is
4812 // already a mapping for $source$, in which case
4813 // the old mapping will be merged with the new
4814 Type val = mapping.get(source.tsym);
4815 if (val != null) {
4816 if (val.isSuperBound() && target.isSuperBound()) {
4817 val = isSubtype(wildLowerBound(val), wildLowerBound(target))
4818 ? target : val;
4819 } else if (val.isExtendsBound() && target.isExtendsBound()) {
4820 val = isSubtype(wildUpperBound(val), wildUpperBound(target))
4821 ? val : target;
4822 } else if (!isSameType(val, target)) {
4823 throw new AdaptFailure();
4824 }
4825 } else {
4826 val = target;
4827 from.append(source);
4828 to.append(target);
4829 }
4830 mapping.put(source.tsym, val);
4831 return null;
4832 }
4833
4834 @Override
4835 public Void visitType(Type source, Type target) {
4836 return null;
4837 }
4838
4839 private Set<TypePair> cache = new HashSet<>();
4840
4841 private void adaptRecursive(Type source, Type target) {
4842 TypePair pair = new TypePair(source, target);
4843 if (cache.add(pair)) {
4844 try {
4845 visit(source, target);
4846 } finally {
4847 cache.remove(pair);
4848 }
4849 }
4850 }
4851
4852 private void adaptRecursive(List<Type> source, List<Type> target) {
4853 if (source.length() == target.length()) {
4854 while (source.nonEmpty()) {
4855 adaptRecursive(source.head, target.head);
4856 source = source.tail;
4857 target = target.tail;
4858 }
4859 }
4860 }
4861 }
4862
4863 public static class AdaptFailure extends RuntimeException {
4864 static final long serialVersionUID = -7490231548272701566L;
4865 }
4866
4867 private void adaptSelf(Type t,
4868 ListBuffer<Type> from,
4869 ListBuffer<Type> to) {
4870 try {
4871 //if (t.tsym.type != t)
4872 adapt(t.tsym.type, t, from, to);
4873 } catch (AdaptFailure ex) {
4874 // Adapt should never fail calculating a mapping from
4875 // t.tsym.type to t as there can be no merge problem.
4876 throw new AssertionError(ex);
4877 }
4878 }
4879 // </editor-fold>
4880
4881 /**
4882 * Rewrite all type variables (universal quantifiers) in the given
4883 * type to wildcards (existential quantifiers). This is used to
4884 * determine if a cast is allowed. For example, if high is true
4885 * and {@code T <: Number}, then {@code List<T>} is rewritten to
4886 * {@code List<? extends Number>}. Since {@code List<Integer> <:
4887 * List<? extends Number>} a {@code List<T>} can be cast to {@code
4888 * List<Integer>} with a warning.
4889 * @param t a type
4890 * @param high if true return an upper bound; otherwise a lower
4891 * bound
4892 * @param rewriteTypeVars only rewrite captured wildcards if false;
4893 * otherwise rewrite all type variables
4894 * @return the type rewritten with wildcards (existential
4895 * quantifiers) only
4896 */
4897 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) {
4898 return new Rewriter(high, rewriteTypeVars).visit(t);
4899 }
4900
4901 class Rewriter extends UnaryVisitor<Type> {
4902
4903 boolean high;
4904 boolean rewriteTypeVars;
4905
4906 Rewriter(boolean high, boolean rewriteTypeVars) {
4907 this.high = high;
4908 this.rewriteTypeVars = rewriteTypeVars;
4909 }
4910
4911 @Override
4912 public Type visitClassType(ClassType t, Void s) {
4913 ListBuffer<Type> rewritten = new ListBuffer<>();
4914 boolean changed = false;
4915 for (Type arg : t.allparams()) {
4916 Type bound = visit(arg);
4917 if (arg != bound) {
4918 changed = true;
4919 }
4920 rewritten.append(bound);
4921 }
4922 if (changed)
4923 return subst(t.tsym.type,
4924 t.tsym.type.allparams(),
4925 rewritten.toList());
4926 else
4927 return t;
4928 }
4929
4930 public Type visitType(Type t, Void s) {
4931 return t;
4932 }
4933
4934 @Override
4935 public Type visitCapturedType(CapturedType t, Void s) {
4936 Type w_bound = t.wildcard.type;
4937 Type bound = w_bound.contains(t) ?
4938 erasure(w_bound) :
4939 visit(w_bound);
4940 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind);
4941 }
4942
4943 @Override
4944 public Type visitTypeVar(TypeVar t, Void s) {
4945 if (rewriteTypeVars) {
4946 Type bound = t.getUpperBound().contains(t) ?
4947 erasure(t.getUpperBound()) :
4948 visit(t.getUpperBound());
4949 return rewriteAsWildcardType(bound, t, EXTENDS);
4950 } else {
4951 return t;
4952 }
4953 }
4954
4955 @Override
4956 public Type visitWildcardType(WildcardType t, Void s) {
4957 Type bound2 = visit(t.type);
4958 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind);
4959 }
4960
4961 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) {
4962 switch (bk) {
4963 case EXTENDS: return high ?
4964 makeExtendsWildcard(B(bound), formal) :
4965 makeExtendsWildcard(syms.objectType, formal);
4966 case SUPER: return high ?
4967 makeSuperWildcard(syms.botType, formal) :
4968 makeSuperWildcard(B(bound), formal);
4969 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal);
4970 default:
4971 Assert.error("Invalid bound kind " + bk);
4972 return null;
4973 }
4974 }
4975
4976 Type B(Type t) {
4977 while (t.hasTag(WILDCARD)) {
4978 WildcardType w = (WildcardType)t;
4979 t = high ?
4980 w.getExtendsBound() :
4981 w.getSuperBound();
4982 if (t == null) {
4983 t = high ? syms.objectType : syms.botType;
4984 }
4985 }
4986 return t;
4987 }
4988 }
4989
4990
4991 /**
4992 * Create a wildcard with the given upper (extends) bound; create
4993 * an unbounded wildcard if bound is Object.
4994 *
4995 * @param bound the upper bound
4996 * @param formal the formal type parameter that will be
4997 * substituted by the wildcard
4998 */
4999 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) {
5000 if (bound == syms.objectType) {
5001 return new WildcardType(syms.objectType,
5002 BoundKind.UNBOUND,
5003 syms.boundClass,
5004 formal);
5005 } else {
5006 return new WildcardType(bound,
5007 BoundKind.EXTENDS,
5008 syms.boundClass,
5009 formal);
5010 }
5011 }
5012
5013 /**
5014 * Create a wildcard with the given lower (super) bound; create an
5015 * unbounded wildcard if bound is bottom (type of {@code null}).
5016 *
5017 * @param bound the lower bound
5018 * @param formal the formal type parameter that will be
5019 * substituted by the wildcard
5020 */
5021 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) {
5022 if (bound.hasTag(BOT)) {
5023 return new WildcardType(syms.objectType,
5024 BoundKind.UNBOUND,
5025 syms.boundClass,
5026 formal);
5027 } else {
5028 return new WildcardType(bound,
5029 BoundKind.SUPER,
5030 syms.boundClass,
5031 formal);
5032 }
5033 }
5034
5035 /**
5036 * A wrapper for a type that allows use in sets.
5037 */
5038 public static class UniqueType {
5039 public final Type type;
5040 final Types types;
5041 private boolean encodeTypeSig;
5042
5043 public UniqueType(Type type, Types types, boolean encodeTypeSig) {
5044 this.type = type;
5045 this.types = types;
5046 this.encodeTypeSig = encodeTypeSig;
5047 }
5048
5049 public UniqueType(Type type, Types types) {
5050 this(type, types, true);
5051 }
5052
5053 public int hashCode() {
5054 return types.hashCode(type);
5055 }
5056
5057 public boolean equals(Object obj) {
5058 return (obj instanceof UniqueType uniqueType) &&
5059 types.isSameType(type, uniqueType.type);
5060 }
5061
5062 public boolean encodeTypeSig() {
5063 return encodeTypeSig;
5064 }
5065
5066 public String toString() {
5067 return type.toString();
5068 }
5069
5070 }
5071 // </editor-fold>
5072
5073 // <editor-fold defaultstate="collapsed" desc="Visitors">
5074 /**
5075 * A default visitor for types. All visitor methods except
5076 * visitType are implemented by delegating to visitType. Concrete
5077 * subclasses must provide an implementation of visitType and can
5078 * override other methods as needed.
5079 *
5080 * @param <R> the return type of the operation implemented by this
5081 * visitor; use Void if no return type is needed.
5082 * @param <S> the type of the second argument (the first being the
5083 * type itself) of the operation implemented by this visitor; use
5084 * Void if a second argument is not needed.
5085 */
5086 public abstract static class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> {
5087 public final R visit(Type t, S s) { return t.accept(this, s); }
5088 public R visitClassType(ClassType t, S s) { return visitType(t, s); }
5089 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); }
5090 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); }
5091 public R visitMethodType(MethodType t, S s) { return visitType(t, s); }
5092 public R visitPackageType(PackageType t, S s) { return visitType(t, s); }
5093 public R visitModuleType(ModuleType t, S s) { return visitType(t, s); }
5094 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); }
5095 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); }
5096 public R visitForAll(ForAll t, S s) { return visitType(t, s); }
5097 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); }
5098 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); }
5099 }
5100
5101 /**
5102 * A default visitor for symbols. All visitor methods except
5103 * visitSymbol are implemented by delegating to visitSymbol. Concrete
5104 * subclasses must provide an implementation of visitSymbol and can
5105 * override other methods as needed.
5106 *
5107 * @param <R> the return type of the operation implemented by this
5108 * visitor; use Void if no return type is needed.
5109 * @param <S> the type of the second argument (the first being the
5110 * symbol itself) of the operation implemented by this visitor; use
5111 * Void if a second argument is not needed.
5112 */
5113 public abstract static class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> {
5114 public final R visit(Symbol s, S arg) { return s.accept(this, arg); }
5115 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); }
5116 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); }
5117 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); }
5118 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); }
5119 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); }
5120 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); }
5121 }
5122
5123 /**
5124 * A <em>simple</em> visitor for types. This visitor is simple as
5125 * captured wildcards, for-all types (generic methods), and
5126 * undetermined type variables (part of inference) are hidden.
5127 * Captured wildcards are hidden by treating them as type
5128 * variables and the rest are hidden by visiting their qtypes.
5129 *
5130 * @param <R> the return type of the operation implemented by this
5131 * visitor; use Void if no return type is needed.
5132 * @param <S> the type of the second argument (the first being the
5133 * type itself) of the operation implemented by this visitor; use
5134 * Void if a second argument is not needed.
5135 */
5136 public abstract static class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> {
5137 @Override
5138 public R visitCapturedType(CapturedType t, S s) {
5139 return visitTypeVar(t, s);
5140 }
5141 @Override
5142 public R visitForAll(ForAll t, S s) {
5143 return visit(t.qtype, s);
5144 }
5145 @Override
5146 public R visitUndetVar(UndetVar t, S s) {
5147 return visit(t.qtype, s);
5148 }
5149 }
5150
5151 /**
5152 * A plain relation on types. That is a 2-ary function on the
5153 * form Type × Type → Boolean.
5154 * <!-- In plain text: Type x Type -> Boolean -->
5155 */
5156 public abstract static class TypeRelation extends SimpleVisitor<Boolean,Type> {}
5157
5158 /**
5159 * A convenience visitor for implementing operations that only
5160 * require one argument (the type itself), that is, unary
5161 * operations.
5162 *
5163 * @param <R> the return type of the operation implemented by this
5164 * visitor; use Void if no return type is needed.
5165 */
5166 public abstract static class UnaryVisitor<R> extends SimpleVisitor<R,Void> {
5167 public final R visit(Type t) { return t.accept(this, null); }
5168 }
5169
5170 /**
5171 * A visitor for implementing a mapping from types to types. The
5172 * default behavior of this class is to implement the identity
5173 * mapping (mapping a type to itself). This can be overridden in
5174 * subclasses.
5175 *
5176 * @param <S> the type of the second argument (the first being the
5177 * type itself) of this mapping; use Void if a second argument is
5178 * not needed.
5179 */
5180 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> {
5181 public final Type visit(Type t) { return t.accept(this, null); }
5182 public Type visitType(Type t, S s) { return t; }
5183 }
5184
5185 /**
5186 * An abstract class for mappings from types to types (see {@link Type#map(TypeMapping)}.
5187 * This class implements the functional interface {@code Function}, that allows it to be used
5188 * fluently in stream-like processing.
5189 */
5190 public static class TypeMapping<S> extends MapVisitor<S> implements Function<Type, Type> {
5191 @Override
5192 public Type apply(Type type) { return visit(type); }
5193
5194 List<Type> visit(List<Type> ts, S s) {
5195 return ts.map(t -> visit(t, s));
5196 }
5197
5198 @Override
5199 public Type visitCapturedType(CapturedType t, S s) {
5200 return visitTypeVar(t, s);
5201 }
5202 }
5203 // </editor-fold>
5204
5205
5206 // <editor-fold defaultstate="collapsed" desc="Annotation support">
5207
5208 public RetentionPolicy getRetention(Attribute.Compound a) {
5209 return getRetention(a.type.tsym);
5210 }
5211
5212 public RetentionPolicy getRetention(TypeSymbol sym) {
5213 RetentionPolicy vis = RetentionPolicy.CLASS; // the default
5214 Attribute.Compound c = sym.attribute(syms.retentionType.tsym);
5215 if (c != null) {
5216 Attribute value = c.member(names.value);
5217 if (value != null && value instanceof Attribute.Enum attributeEnum) {
5218 Name levelName = attributeEnum.value.name;
5219 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE;
5220 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS;
5221 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME;
5222 else ;// /* fail soft */ throw new AssertionError(levelName);
5223 }
5224 }
5225 return vis;
5226 }
5227 // </editor-fold>
5228
5229 // <editor-fold defaultstate="collapsed" desc="Signature Generation">
5230
5231 public abstract static class SignatureGenerator {
5232
5233 public static class InvalidSignatureException extends RuntimeException {
5234 private static final long serialVersionUID = 0;
5235
5236 private final transient Type type;
5237
5238 InvalidSignatureException(Type type) {
5239 this.type = type;
5240 }
5241
5242 public Type type() {
5243 return type;
5244 }
5245
5246 @Override
5247 public Throwable fillInStackTrace() {
5248 // This is an internal exception; the stack trace is irrelevant.
5249 return this;
5250 }
5251 }
5252
5253 private final Types types;
5254
5255 protected abstract void append(char ch);
5256 protected abstract void append(byte[] ba);
5257 protected abstract void append(Name name);
5258 protected void classReference(ClassSymbol c) { /* by default: no-op */ }
5259
5260 protected SignatureGenerator(Types types) {
5261 this.types = types;
5262 }
5263
5264 protected void reportIllegalSignature(Type t) {
5265 throw new InvalidSignatureException(t);
5266 }
5267
5268 /**
5269 * Assemble signature of given type in string buffer.
5270 */
5271 public void assembleSig(Type type) {
5272 switch (type.getTag()) {
5273 case BYTE:
5274 append('B');
5275 break;
5276 case SHORT:
5277 append('S');
5278 break;
5279 case CHAR:
5280 append('C');
5281 break;
5282 case INT:
5283 append('I');
5284 break;
5285 case LONG:
5286 append('J');
5287 break;
5288 case FLOAT:
5289 append('F');
5290 break;
5291 case DOUBLE:
5292 append('D');
5293 break;
5294 case BOOLEAN:
5295 append('Z');
5296 break;
5297 case VOID:
5298 append('V');
5299 break;
5300 case CLASS:
5301 if (type.isCompound()) {
5302 reportIllegalSignature(type);
5303 }
5304 if (types.allowPrimitiveClasses && type.isPrimitiveClass())
5305 append('Q');
5306 else
5307 append('L');
5308 assembleClassSig(type);
5309 append(';');
5310 break;
5311 case ARRAY:
5312 ArrayType at = (ArrayType) type;
5313 append('[');
5314 assembleSig(at.elemtype);
5315 break;
5316 case METHOD:
5317 MethodType mt = (MethodType) type;
5318 append('(');
5319 assembleSig(mt.argtypes);
5320 append(')');
5321 assembleSig(mt.restype);
5322 if (hasTypeVar(mt.thrown)) {
5323 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) {
5324 append('^');
5325 assembleSig(l.head);
5326 }
5327 }
5328 break;
5329 case WILDCARD: {
5330 Type.WildcardType ta = (Type.WildcardType) type;
5331 switch (ta.kind) {
5332 case SUPER:
5333 append('-');
5334 assembleSig(ta.type);
5335 break;
5336 case EXTENDS:
5337 append('+');
5338 assembleSig(ta.type);
5339 break;
5340 case UNBOUND:
5341 append('*');
5342 break;
5343 default:
5344 throw new AssertionError(ta.kind);
5345 }
5346 break;
5347 }
5348 case TYPEVAR:
5349 if (((TypeVar)type).isCaptured()) {
5350 reportIllegalSignature(type);
5351 }
5352 append('T');
5353 append(type.tsym.name);
5354 append(';');
5355 break;
5356 case FORALL:
5357 Type.ForAll ft = (Type.ForAll) type;
5358 assembleParamsSig(ft.tvars);
5359 assembleSig(ft.qtype);
5360 break;
5361 default:
5362 throw new AssertionError("typeSig " + type.getTag());
5363 }
5364 }
5365
5366 public boolean hasTypeVar(List<Type> l) {
5367 while (l.nonEmpty()) {
5368 if (l.head.hasTag(TypeTag.TYPEVAR)) {
5369 return true;
5370 }
5371 l = l.tail;
5372 }
5373 return false;
5374 }
5375
5376 public void assembleClassSig(Type type) {
5377 ClassType ct = (ClassType) type;
5378 ClassSymbol c = (ClassSymbol) ct.tsym;
5379 classReference(c);
5380 Type outer = ct.getEnclosingType();
5381 if (outer.allparams().nonEmpty()) {
5382 boolean rawOuter =
5383 c.owner.kind == MTH || // either a local class
5384 c.name == types.names.empty; // or anonymous
5385 assembleClassSig(rawOuter
5386 ? types.erasure(outer)
5387 : outer);
5388 append(rawOuter ? '$' : '.');
5389 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname));
5390 append(rawOuter
5391 ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength())
5392 : c.name);
5393 } else {
5394 append(externalize(c.flatname));
5395 }
5396 if (ct.getTypeArguments().nonEmpty()) {
5397 append('<');
5398 assembleSig(ct.getTypeArguments());
5399 append('>');
5400 }
5401 }
5402
5403 public void assembleParamsSig(List<Type> typarams) {
5404 append('<');
5405 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) {
5406 Type.TypeVar tvar = (Type.TypeVar) ts.head;
5407 append(tvar.tsym.name);
5408 List<Type> bounds = types.getBounds(tvar);
5409 if ((bounds.head.tsym.flags() & INTERFACE) != 0) {
5410 append(':');
5411 }
5412 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) {
5413 append(':');
5414 assembleSig(l.head);
5415 }
5416 }
5417 append('>');
5418 }
5419
5420 public void assembleSig(List<Type> types) {
5421 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) {
5422 assembleSig(ts.head);
5423 }
5424 }
5425 }
5426
5427 public Type constantType(LoadableConstant c) {
5428 switch (c.poolTag()) {
5429 case ClassFile.CONSTANT_Class:
5430 return syms.classType;
5431 case ClassFile.CONSTANT_String:
5432 return syms.stringType;
5433 case ClassFile.CONSTANT_Integer:
5434 return syms.intType;
5435 case ClassFile.CONSTANT_Float:
5436 return syms.floatType;
5437 case ClassFile.CONSTANT_Long:
5438 return syms.longType;
5439 case ClassFile.CONSTANT_Double:
5440 return syms.doubleType;
5441 case ClassFile.CONSTANT_MethodHandle:
5442 return syms.methodHandleType;
5443 case ClassFile.CONSTANT_MethodType:
5444 return syms.methodTypeType;
5445 case ClassFile.CONSTANT_Dynamic:
5446 return ((DynamicVarSymbol)c).type;
5447 default:
5448 throw new AssertionError("Not a loadable constant: " + c.poolTag());
5449 }
5450 }
5451 // </editor-fold>
5452
5453 public void newRound() {
5454 descCache._map.clear();
5455 isDerivedRawCache.clear();
5456 implCache._map.clear();
5457 membersCache._map.clear();
5458 closureCache.clear();
5459 }
5460 }