1 /*
2 * Copyright (c) 2003, 2021, 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.ClassType.Flavor;
47 import com.sun.tools.javac.code.Type.UndetVar.InferenceBound;
48 import com.sun.tools.javac.code.TypeMetadata.Entry.Kind;
49 import com.sun.tools.javac.comp.AttrContext;
50 import com.sun.tools.javac.comp.Check;
51 import com.sun.tools.javac.comp.Enter;
52 import com.sun.tools.javac.comp.Env;
53 import com.sun.tools.javac.jvm.ClassFile;
54 import com.sun.tools.javac.util.*;
55
56 import static com.sun.tools.javac.code.BoundKind.*;
57 import static com.sun.tools.javac.code.Flags.*;
58 import static com.sun.tools.javac.code.Kinds.Kind.*;
59 import static com.sun.tools.javac.code.Scope.*;
60 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;
61 import static com.sun.tools.javac.code.Symbol.*;
62 import static com.sun.tools.javac.code.Type.*;
63 import static com.sun.tools.javac.code.TypeTag.*;
64 import static com.sun.tools.javac.jvm.ClassFile.externalize;
65 import com.sun.tools.javac.resources.CompilerProperties.Fragments;
66
67 /**
68 * Utility class containing various operations on types.
69 *
70 * <p>Unless other names are more illustrative, the following naming
71 * conventions should be observed in this file:
72 *
73 * <dl>
74 * <dt>t</dt>
75 * <dd>If the first argument to an operation is a type, it should be named t.</dd>
76 * <dt>s</dt>
77 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd>
78 * <dt>ts</dt>
79 * <dd>If an operations takes a list of types, the first should be named ts.</dd>
80 * <dt>ss</dt>
81 * <dd>A second list of types should be named ss.</dd>
82 * </dl>
83 *
84 * <p><b>This is NOT part of any supported API.
85 * If you write code that depends on this, you do so at your own risk.
86 * This code and its internal interfaces are subject to change or
87 * deletion without notice.</b>
88 */
89 public class Types {
90 protected static final Context.Key<Types> typesKey = new Context.Key<>();
91
92 final Symtab syms;
93 final JavacMessages messages;
94 final Names names;
95 final boolean allowDefaultMethods;
96 final boolean mapCapturesToBounds;
97 final boolean allowValueBasedClasses;
98 final Check chk;
99 final Enter enter;
100 JCDiagnostic.Factory diags;
101 List<Warner> warnStack = List.nil();
102 final Name capturedName;
103
104 public final Warner noWarnings;
105
106 // <editor-fold defaultstate="collapsed" desc="Instantiating">
107 public static Types instance(Context context) {
108 Types instance = context.get(typesKey);
109 if (instance == null)
110 instance = new Types(context);
111 return instance;
112 }
113
114 protected Types(Context context) {
115 context.put(typesKey, this);
116 syms = Symtab.instance(context);
117 names = Names.instance(context);
118 Source source = Source.instance(context);
119 allowDefaultMethods = Feature.DEFAULT_METHODS.allowedInSource(source);
120 mapCapturesToBounds = Feature.MAP_CAPTURES_TO_BOUNDS.allowedInSource(source);
121 chk = Check.instance(context);
122 enter = Enter.instance(context);
123 capturedName = names.fromString("<captured wildcard>");
124 messages = JavacMessages.instance(context);
125 diags = JCDiagnostic.Factory.instance(context);
126 noWarnings = new Warner(null);
127 Options options = Options.instance(context);
128 allowValueBasedClasses = options.isSet("allowValueBasedClasses");
129 }
130 // </editor-fold>
131
132 // <editor-fold defaultstate="collapsed" desc="bounds">
133 /**
134 * Get a wildcard's upper bound, returning non-wildcards unchanged.
135 * @param t a type argument, either a wildcard or a type
136 */
137 public Type wildUpperBound(Type t) {
138 if (t.hasTag(WILDCARD)) {
139 WildcardType w = (WildcardType) t;
140 if (w.isSuperBound())
141 return w.bound == null ? syms.objectType : w.bound.getUpperBound();
142 else
143 return wildUpperBound(w.type);
144 }
145 else return t;
146 }
147
148 /**
149 * Get a capture variable's upper bound, returning other types unchanged.
150 * @param t a type
151 */
152 public Type cvarUpperBound(Type t) {
153 if (t.hasTag(TYPEVAR)) {
154 TypeVar v = (TypeVar) t;
155 return v.isCaptured() ? cvarUpperBound(v.getUpperBound()) : v;
156 }
157 else return t;
158 }
159
160 /**
161 * Get a wildcard's lower bound, returning non-wildcards unchanged.
162 * @param t a type argument, either a wildcard or a type
163 */
164 public Type wildLowerBound(Type t) {
165 if (t.hasTag(WILDCARD)) {
166 WildcardType w = (WildcardType) t;
167 return w.isExtendsBound() ? syms.botType : wildLowerBound(w.type);
168 }
169 else return t;
170 }
171
172 /**
173 * Get a capture variable's lower bound, returning other types unchanged.
174 * @param t a type
175 */
176 public Type cvarLowerBound(Type t) {
177 if (t.hasTag(TYPEVAR) && ((TypeVar) t).isCaptured()) {
178 return cvarLowerBound(t.getLowerBound());
179 }
180 else return t;
181 }
182
183 /**
184 * Recursively skip type-variables until a class/array type is found; capture conversion is then
185 * (optionally) applied to the resulting type. This is useful for i.e. computing a site that is
186 * suitable for a method lookup.
187 */
188 public Type skipTypeVars(Type site, boolean capture) {
189 while (site.hasTag(TYPEVAR)) {
190 site = site.getUpperBound();
191 }
192 return capture ? capture(site) : site;
193 }
194 // </editor-fold>
195
196 // <editor-fold defaultstate="collapsed" desc="projections">
197
198 /**
199 * A projection kind. See {@link TypeProjection}
200 */
201 enum ProjectionKind {
202 UPWARDS() {
203 @Override
204 ProjectionKind complement() {
205 return DOWNWARDS;
206 }
207 },
208 DOWNWARDS() {
209 @Override
210 ProjectionKind complement() {
211 return UPWARDS;
212 }
213 };
214
215 abstract ProjectionKind complement();
216 }
217
218 /**
219 * This visitor performs upwards and downwards projections on types.
220 *
221 * A projection is defined as a function that takes a type T, a set of type variables V and that
222 * produces another type S.
223 *
224 * An upwards projection maps a type T into a type S such that (i) T has no variables in V,
225 * and (ii) S is an upper bound of T.
226 *
227 * A downwards projection maps a type T into a type S such that (i) T has no variables in V,
228 * and (ii) S is a lower bound of T.
229 *
230 * Note that projections are only allowed to touch variables in V. Therefore, it is possible for
231 * a projection to leave its input type unchanged if it does not contain any variables in V.
232 *
233 * Moreover, note that while an upwards projection is always defined (every type as an upper bound),
234 * a downwards projection is not always defined.
235 *
236 * Examples:
237 *
238 * {@code upwards(List<#CAP1>, [#CAP1]) = List<? extends String>, where #CAP1 <: String }
239 * {@code downwards(List<#CAP2>, [#CAP2]) = List<? super String>, where #CAP2 :> String }
240 * {@code upwards(List<#CAP1>, [#CAP2]) = List<#CAP1> }
241 * {@code downwards(List<#CAP1>, [#CAP1]) = not defined }
242 */
243 class TypeProjection extends TypeMapping<ProjectionKind> {
244
245 List<Type> vars;
246 Set<Type> seen = new HashSet<>();
247
248 public TypeProjection(List<Type> vars) {
249 this.vars = vars;
250 }
251
252 @Override
253 public Type visitClassType(ClassType t, ProjectionKind pkind) {
254 if (t.isCompound()) {
255 List<Type> components = directSupertypes(t);
256 List<Type> components1 = components.map(c -> c.map(this, pkind));
257 if (components == components1) return t;
258 else return makeIntersectionType(components1);
259 } else {
260 Type outer = t.getEnclosingType();
261 Type outer1 = visit(outer, pkind);
262 List<Type> typarams = t.getTypeArguments();
263 List<Type> formals = t.tsym.type.getTypeArguments();
264 ListBuffer<Type> typarams1 = new ListBuffer<>();
265 boolean changed = false;
266 for (Type actual : typarams) {
267 Type t2 = mapTypeArgument(t, formals.head.getUpperBound(), actual, pkind);
268 if (t2.hasTag(BOT)) {
269 //not defined
270 return syms.botType;
271 }
272 typarams1.add(t2);
273 changed |= actual != t2;
274 formals = formals.tail;
275 }
276 if (outer1 == outer && !changed) return t;
277 else return new ClassType(outer1, typarams1.toList(), t.tsym, t.getMetadata(), t.getFlavor()) {
278 @Override
279 protected boolean needsStripping() {
280 return true;
281 }
282 };
283 }
284 }
285
286 @Override
287 public Type visitArrayType(ArrayType t, ProjectionKind s) {
288 Type elemtype = t.elemtype;
289 Type elemtype1 = visit(elemtype, s);
290 if (elemtype1 == elemtype) {
291 return t;
292 } else if (elemtype1.hasTag(BOT)) {
293 //undefined
294 return syms.botType;
295 } else {
296 return new ArrayType(elemtype1, t.tsym, t.metadata) {
297 @Override
298 protected boolean needsStripping() {
299 return true;
300 }
301 };
302 }
303 }
304
305 @Override
306 public Type visitTypeVar(TypeVar t, ProjectionKind pkind) {
307 if (vars.contains(t)) {
308 if (seen.add(t)) {
309 try {
310 final Type bound;
311 switch (pkind) {
312 case UPWARDS:
313 bound = t.getUpperBound();
314 break;
315 case DOWNWARDS:
316 bound = (t.getLowerBound() == null) ?
317 syms.botType :
318 t.getLowerBound();
319 break;
320 default:
321 Assert.error();
322 return null;
323 }
324 return bound.map(this, pkind);
325 } finally {
326 seen.remove(t);
327 }
328 } else {
329 //cycle
330 return pkind == ProjectionKind.UPWARDS ?
331 syms.objectType : syms.botType;
332 }
333 } else {
334 return t;
335 }
336 }
337
338 private Type mapTypeArgument(Type site, Type declaredBound, Type t, ProjectionKind pkind) {
339 return t.containsAny(vars) ?
340 t.map(new TypeArgumentProjection(site, declaredBound), pkind) :
341 t;
342 }
343
344 class TypeArgumentProjection extends TypeMapping<ProjectionKind> {
345
346 Type site;
347 Type declaredBound;
348
349 TypeArgumentProjection(Type site, Type declaredBound) {
350 this.site = site;
351 this.declaredBound = declaredBound;
352 }
353
354 @Override
355 public Type visitType(Type t, ProjectionKind pkind) {
356 //type argument is some type containing restricted vars
357 if (pkind == ProjectionKind.DOWNWARDS) {
358 //not defined
359 return syms.botType;
360 }
361 Type upper = t.map(TypeProjection.this, ProjectionKind.UPWARDS);
362 Type lower = t.map(TypeProjection.this, ProjectionKind.DOWNWARDS);
363 List<Type> formals = site.tsym.type.getTypeArguments();
364 BoundKind bk;
365 Type bound;
366 if (!isSameType(upper, syms.objectType) &&
367 (declaredBound.containsAny(formals) ||
368 !isSubtype(declaredBound, upper))) {
369 bound = upper;
370 bk = EXTENDS;
371 } else if (!lower.hasTag(BOT)) {
372 bound = lower;
373 bk = SUPER;
374 } else {
375 bound = syms.objectType;
376 bk = UNBOUND;
377 }
378 return makeWildcard(bound, bk);
379 }
380
381 @Override
382 public Type visitWildcardType(WildcardType wt, ProjectionKind pkind) {
383 //type argument is some wildcard whose bound contains restricted vars
384 Type bound = syms.botType;
385 BoundKind bk = wt.kind;
386 switch (wt.kind) {
387 case EXTENDS:
388 bound = wt.type.map(TypeProjection.this, pkind);
389 if (bound.hasTag(BOT)) {
390 return syms.botType;
391 }
392 break;
393 case SUPER:
394 bound = wt.type.map(TypeProjection.this, pkind.complement());
395 if (bound.hasTag(BOT)) {
396 bound = syms.objectType;
397 bk = UNBOUND;
398 }
399 break;
400 }
401 return makeWildcard(bound, bk);
402 }
403
404 private Type makeWildcard(Type bound, BoundKind bk) {
405 return new WildcardType(bound, bk, syms.boundClass) {
406 @Override
407 protected boolean needsStripping() {
408 return true;
409 }
410 };
411 }
412 }
413 }
414
415 /**
416 * Computes an upward projection of given type, and vars. See {@link TypeProjection}.
417 *
418 * @param t the type to be projected
419 * @param vars the set of type variables to be mapped
420 * @return the type obtained as result of the projection
421 */
422 public Type upward(Type t, List<Type> vars) {
423 return t.map(new TypeProjection(vars), ProjectionKind.UPWARDS);
424 }
425
426 /**
427 * Computes the set of captured variables mentioned in a given type. See {@link CaptureScanner}.
428 * This routine is typically used to computed the input set of variables to be used during
429 * an upwards projection (see {@link Types#upward(Type, List)}).
430 *
431 * @param t the type where occurrences of captured variables have to be found
432 * @return the set of captured variables found in t
433 */
434 public List<Type> captures(Type t) {
435 CaptureScanner cs = new CaptureScanner();
436 Set<Type> captures = new HashSet<>();
437 cs.visit(t, captures);
438 return List.from(captures);
439 }
440
441 /**
442 * This visitor scans a type recursively looking for occurrences of captured type variables.
443 */
444 class CaptureScanner extends SimpleVisitor<Void, Set<Type>> {
445
446 @Override
447 public Void visitType(Type t, Set<Type> types) {
448 return null;
449 }
450
451 @Override
452 public Void visitClassType(ClassType t, Set<Type> seen) {
453 if (t.isCompound()) {
454 directSupertypes(t).forEach(s -> visit(s, seen));
455 } else {
456 t.allparams().forEach(ta -> visit(ta, seen));
457 }
458 return null;
459 }
460
461 @Override
462 public Void visitArrayType(ArrayType t, Set<Type> seen) {
463 return visit(t.elemtype, seen);
464 }
465
466 @Override
467 public Void visitWildcardType(WildcardType t, Set<Type> seen) {
468 visit(t.type, seen);
469 return null;
470 }
471
472 @Override
473 public Void visitTypeVar(TypeVar t, Set<Type> seen) {
474 if ((t.tsym.flags() & Flags.SYNTHETIC) != 0 && seen.add(t)) {
475 visit(t.getUpperBound(), seen);
476 }
477 return null;
478 }
479
480 @Override
481 public Void visitCapturedType(CapturedType t, Set<Type> seen) {
482 if (seen.add(t)) {
483 visit(t.getUpperBound(), seen);
484 visit(t.getLowerBound(), seen);
485 }
486 return null;
487 }
488 }
489
490 // </editor-fold>
491
492 // <editor-fold defaultstate="collapsed" desc="isUnbounded">
493 /**
494 * Checks that all the arguments to a class are unbounded
495 * wildcards or something else that doesn't make any restrictions
496 * on the arguments. If a class isUnbounded, a raw super- or
497 * subclass can be cast to it without a warning.
498 * @param t a type
499 * @return true iff the given type is unbounded or raw
500 */
501 public boolean isUnbounded(Type t) {
502 return isUnbounded.visit(t);
503 }
504 // where
505 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() {
506
507 public Boolean visitType(Type t, Void ignored) {
508 return true;
509 }
510
511 @Override
512 public Boolean visitClassType(ClassType t, Void ignored) {
513 List<Type> parms = t.tsym.type.allparams();
514 List<Type> args = t.allparams();
515 while (parms.nonEmpty()) {
516 WildcardType unb = new WildcardType(syms.objectType,
517 BoundKind.UNBOUND,
518 syms.boundClass,
519 (TypeVar)parms.head);
520 if (!containsType(args.head, unb))
521 return false;
522 parms = parms.tail;
523 args = args.tail;
524 }
525 return true;
526 }
527 };
528 // </editor-fold>
529
530 // <editor-fold defaultstate="collapsed" desc="asSub">
531 /**
532 * Return the least specific subtype of t that starts with symbol
533 * sym. If none exists, return null. The least specific subtype
534 * is determined as follows:
535 *
536 * <p>If there is exactly one parameterized instance of sym that is a
537 * subtype of t, that parameterized instance is returned.<br>
538 * Otherwise, if the plain type or raw type `sym' is a subtype of
539 * type t, the type `sym' itself is returned. Otherwise, null is
540 * returned.
541 */
542 public Type asSub(Type t, Symbol sym) {
543 return asSub.visit(t, sym);
544 }
545 // where
546 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() {
547
548 public Type visitType(Type t, Symbol sym) {
549 return null;
550 }
551
552 @Override
553 public Type visitClassType(ClassType t, Symbol sym) {
554 if (t.tsym == sym)
555 return t;
556 Type base = asSuper(sym.type, t.tsym);
557 if (base == null)
558 return null;
559 ListBuffer<Type> from = new ListBuffer<>();
560 ListBuffer<Type> to = new ListBuffer<>();
561 try {
562 adapt(base, t, from, to);
563 } catch (AdaptFailure ex) {
564 return null;
565 }
566 Type res = subst(sym.type, from.toList(), to.toList());
567 if (!isSubtype(res, t))
568 return null;
569 ListBuffer<Type> openVars = new ListBuffer<>();
570 for (List<Type> l = sym.type.allparams();
571 l.nonEmpty(); l = l.tail)
572 if (res.contains(l.head) && !t.contains(l.head))
573 openVars.append(l.head);
574 if (openVars.nonEmpty()) {
575 if (t.isRaw()) {
576 // The subtype of a raw type is raw
577 res = erasure(res);
578 } else {
579 // Unbound type arguments default to ?
580 List<Type> opens = openVars.toList();
581 ListBuffer<Type> qs = new ListBuffer<>();
582 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) {
583 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND,
584 syms.boundClass, (TypeVar) iter.head));
585 }
586 res = subst(res, opens, qs.toList());
587 }
588 }
589 return res;
590 }
591
592 @Override
593 public Type visitErrorType(ErrorType t, Symbol sym) {
594 return t;
595 }
596 };
597 // </editor-fold>
598
599 // <editor-fold defaultstate="collapsed" desc="isConvertible">
600 /**
601 * Is t a subtype of or convertible via boxing/unboxing
602 * conversion to s?
603 */
604 public boolean isConvertible(Type t, Type s, Warner warn) {
605 if (t.hasTag(ERROR)) {
606 return true;
607 }
608
609 boolean tValue = t.isPrimitiveClass();
610 boolean sValue = s.isPrimitiveClass();
611 if (tValue != sValue) {
612 return tValue ?
613 isSubtype(t.referenceProjection(), s) :
614 !t.hasTag(BOT) && isSubtype(t, s.referenceProjection());
615 }
616
617 boolean tPrimitive = t.isPrimitive();
618 boolean sPrimitive = s.isPrimitive();
619 if (tPrimitive == sPrimitive) {
620 return isSubtypeUnchecked(t, s, warn);
621 }
622 boolean tUndet = t.hasTag(UNDETVAR);
623 boolean sUndet = s.hasTag(UNDETVAR);
624
625 if (tUndet || sUndet) {
626 return tUndet ?
627 isSubtype(t, boxedTypeOrType(s)) :
628 isSubtype(boxedTypeOrType(t), s);
629 }
630
631 return tPrimitive
632 ? isSubtype(boxedClass(t).type, s)
633 : isSubtype(unboxedType(t), s);
634 }
635
636 /**
637 * Is t a subtype of or convertible via boxing/unboxing
638 * conversions to s?
639 */
640 public boolean isConvertible(Type t, Type s) {
641 return isConvertible(t, s, noWarnings);
642 }
643 // </editor-fold>
644
645 // <editor-fold defaultstate="collapsed" desc="findSam">
646
647 /**
648 * Exception used to report a function descriptor lookup failure. The exception
649 * wraps a diagnostic that can be used to generate more details error
650 * messages.
651 */
652 public static class FunctionDescriptorLookupError extends RuntimeException {
653 private static final long serialVersionUID = 0;
654
655 transient JCDiagnostic diagnostic;
656
657 FunctionDescriptorLookupError() {
658 this.diagnostic = null;
659 }
660
661 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) {
662 this.diagnostic = diag;
663 return this;
664 }
665
666 public JCDiagnostic getDiagnostic() {
667 return diagnostic;
668 }
669 }
670
671 /**
672 * A cache that keeps track of function descriptors associated with given
673 * functional interfaces.
674 */
675 class DescriptorCache {
676
677 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<>();
678
679 class FunctionDescriptor {
680 Symbol descSym;
681
682 FunctionDescriptor(Symbol descSym) {
683 this.descSym = descSym;
684 }
685
686 public Symbol getSymbol() {
687 return descSym;
688 }
689
690 public Type getType(Type site) {
691 site = removeWildcards(site);
692 if (site.isIntersection()) {
693 IntersectionClassType ict = (IntersectionClassType)site;
694 for (Type component : ict.getExplicitComponents()) {
695 if (!chk.checkValidGenericType(component)) {
696 //if the inferred functional interface type is not well-formed,
697 //or if it's not a subtype of the original target, issue an error
698 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site)));
699 }
700 }
701 } else {
702 if (!chk.checkValidGenericType(site)) {
703 //if the inferred functional interface type is not well-formed,
704 //or if it's not a subtype of the original target, issue an error
705 throw failure(diags.fragment(Fragments.NoSuitableFunctionalIntfInst(site)));
706 }
707 }
708 return memberType(site, descSym);
709 }
710 }
711
712 class Entry {
713 final FunctionDescriptor cachedDescRes;
714 final int prevMark;
715
716 public Entry(FunctionDescriptor cachedDescRes,
717 int prevMark) {
718 this.cachedDescRes = cachedDescRes;
719 this.prevMark = prevMark;
720 }
721
722 boolean matches(int mark) {
723 return this.prevMark == mark;
724 }
725 }
726
727 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError {
728 Entry e = _map.get(origin);
729 CompoundScope members = membersClosure(origin.type, false);
730 if (e == null ||
731 !e.matches(members.getMark())) {
732 FunctionDescriptor descRes = findDescriptorInternal(origin, members);
733 _map.put(origin, new Entry(descRes, members.getMark()));
734 return descRes;
735 }
736 else {
737 return e.cachedDescRes;
738 }
739 }
740
741 /**
742 * Compute the function descriptor associated with a given functional interface
743 */
744 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin,
745 CompoundScope membersCache) throws FunctionDescriptorLookupError {
746 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0 || origin.isSealed()) {
747 //t must be an interface
748 throw failure("not.a.functional.intf", origin);
749 }
750
751 final ListBuffer<Symbol> abstracts = new ListBuffer<>();
752 for (Symbol sym : membersCache.getSymbols(new DescriptorFilter(origin))) {
753 Type mtype = memberType(origin.type, sym);
754 if (abstracts.isEmpty()) {
755 abstracts.append(sym);
756 } else if ((sym.name == abstracts.first().name &&
757 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) {
758 if (!abstracts.stream().filter(msym -> msym.owner.isSubClass(sym.enclClass(), Types.this))
759 .map(msym -> memberType(origin.type, msym))
760 .anyMatch(abstractMType -> isSubSignature(abstractMType, mtype))) {
761 abstracts.append(sym);
762 }
763 } else {
764 //the target method(s) should be the only abstract members of t
765 throw failure("not.a.functional.intf.1", origin,
766 diags.fragment(Fragments.IncompatibleAbstracts(Kinds.kindName(origin), origin)));
767 }
768 }
769 if (abstracts.isEmpty()) {
770 //t must define a suitable non-generic method
771 throw failure("not.a.functional.intf.1", origin,
772 diags.fragment(Fragments.NoAbstracts(Kinds.kindName(origin), origin)));
773 } else if (abstracts.size() == 1) {
774 return new FunctionDescriptor(abstracts.first());
775 } else { // size > 1
776 FunctionDescriptor descRes = mergeDescriptors(origin, abstracts.toList());
777 if (descRes == null) {
778 //we can get here if the functional interface is ill-formed
779 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>();
780 for (Symbol desc : abstracts) {
781 String key = desc.type.getThrownTypes().nonEmpty() ?
782 "descriptor.throws" : "descriptor";
783 descriptors.append(diags.fragment(key, desc.name,
784 desc.type.getParameterTypes(),
785 desc.type.getReturnType(),
786 desc.type.getThrownTypes()));
787 }
788 JCDiagnostic msg =
789 diags.fragment(Fragments.IncompatibleDescsInFunctionalIntf(Kinds.kindName(origin),
790 origin));
791 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors =
792 new JCDiagnostic.MultilineDiagnostic(msg, descriptors.toList());
793 throw failure(incompatibleDescriptors);
794 }
795 return descRes;
796 }
797 }
798
799 /**
800 * Compute a synthetic type for the target descriptor given a list
801 * of override-equivalent methods in the functional interface type.
802 * The resulting method type is a method type that is override-equivalent
803 * and return-type substitutable with each method in the original list.
804 */
805 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) {
806 return mergeAbstracts(methodSyms, origin.type, false)
807 .map(bestSoFar -> new FunctionDescriptor(bestSoFar.baseSymbol()) {
808 @Override
809 public Type getType(Type origin) {
810 Type mt = memberType(origin, getSymbol());
811 return createMethodTypeWithThrown(mt, bestSoFar.type.getThrownTypes());
812 }
813 }).orElse(null);
814 }
815
816 FunctionDescriptorLookupError failure(String msg, Object... args) {
817 return failure(diags.fragment(msg, args));
818 }
819
820 FunctionDescriptorLookupError failure(JCDiagnostic diag) {
821 return new FunctionDescriptorLookupError().setMessage(diag);
822 }
823 }
824
825 private DescriptorCache descCache = new DescriptorCache();
826
827 /**
828 * Find the method descriptor associated to this class symbol - if the
829 * symbol 'origin' is not a functional interface, an exception is thrown.
830 */
831 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError {
832 return descCache.get(origin).getSymbol();
833 }
834
835 /**
836 * Find the type of the method descriptor associated to this class symbol -
837 * if the symbol 'origin' is not a functional interface, an exception is thrown.
838 */
839 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError {
840 return descCache.get(origin.tsym).getType(origin);
841 }
842
843 /**
844 * Is given type a functional interface?
845 */
846 public boolean isFunctionalInterface(TypeSymbol tsym) {
847 try {
848 findDescriptorSymbol(tsym);
849 return true;
850 } catch (FunctionDescriptorLookupError ex) {
851 return false;
852 }
853 }
854
855 public boolean isFunctionalInterface(Type site) {
856 try {
857 findDescriptorType(site);
858 return true;
859 } catch (FunctionDescriptorLookupError ex) {
860 return false;
861 }
862 }
863
864 public Type removeWildcards(Type site) {
865 if (site.getTypeArguments().stream().anyMatch(t -> t.hasTag(WILDCARD))) {
866 //compute non-wildcard parameterization - JLS 9.9
867 List<Type> actuals = site.getTypeArguments();
868 List<Type> formals = site.tsym.type.getTypeArguments();
869 ListBuffer<Type> targs = new ListBuffer<>();
870 for (Type formal : formals) {
871 Type actual = actuals.head;
872 Type bound = formal.getUpperBound();
873 if (actuals.head.hasTag(WILDCARD)) {
874 WildcardType wt = (WildcardType)actual;
875 //check that bound does not contain other formals
876 if (bound.containsAny(formals)) {
877 targs.add(wt.type);
878 } else {
879 //compute new type-argument based on declared bound and wildcard bound
880 switch (wt.kind) {
881 case UNBOUND:
882 targs.add(bound);
883 break;
884 case EXTENDS:
885 targs.add(glb(bound, wt.type));
886 break;
887 case SUPER:
888 targs.add(wt.type);
889 break;
890 default:
891 Assert.error("Cannot get here!");
892 }
893 }
894 } else {
895 //not a wildcard - the new type argument remains unchanged
896 targs.add(actual);
897 }
898 actuals = actuals.tail;
899 }
900 return subst(site.tsym.type, formals, targs.toList());
901 } else {
902 return site;
903 }
904 }
905
906 /**
907 * Create a symbol for a class that implements a given functional interface
908 * and overrides its functional descriptor. This routine is used for two
909 * main purposes: (i) checking well-formedness of a functional interface;
910 * (ii) perform functional interface bridge calculation.
911 */
912 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, Type target, long cflags) {
913 if (target == null || target == syms.unknownType) {
914 return null;
915 }
916 Symbol descSym = findDescriptorSymbol(target.tsym);
917 Type descType = findDescriptorType(target);
918 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass());
919 csym.completer = Completer.NULL_COMPLETER;
920 csym.members_field = WriteableScope.create(csym);
921 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym);
922 csym.members_field.enter(instDescSym);
923 Type.ClassType ctype = new Type.ClassType(Type.noType, List.nil(), csym);
924 ctype.supertype_field = syms.objectType;
925 ctype.interfaces_field = target.isIntersection() ?
926 directSupertypes(target) :
927 List.of(target);
928 csym.type = ctype;
929 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile;
930 return csym;
931 }
932
933 /**
934 * Find the minimal set of methods that are overridden by the functional
935 * descriptor in 'origin'. All returned methods are assumed to have different
936 * erased signatures.
937 */
938 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) {
939 Assert.check(isFunctionalInterface(origin));
940 Symbol descSym = findDescriptorSymbol(origin);
941 CompoundScope members = membersClosure(origin.type, false);
942 ListBuffer<Symbol> overridden = new ListBuffer<>();
943 outer: for (Symbol m2 : members.getSymbolsByName(descSym.name, bridgeFilter)) {
944 if (m2 == descSym) continue;
945 else if (descSym.overrides(m2, origin, Types.this, false)) {
946 for (Symbol m3 : overridden) {
947 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) ||
948 (m3.overrides(m2, origin, Types.this, false) &&
949 (pendingBridges((ClassSymbol)origin, m3.enclClass()) ||
950 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) {
951 continue outer;
952 }
953 }
954 overridden.add(m2);
955 }
956 }
957 return overridden.toList();
958 }
959 //where
960 // Use anonymous class instead of lambda expression intentionally,
961 // because the variable `names` has modifier: final.
962 private Predicate<Symbol> bridgeFilter = new Predicate<Symbol>() {
963 public boolean test(Symbol t) {
964 return t.kind == MTH &&
965 t.name != names.init &&
966 t.name != names.clinit &&
967 (t.flags() & SYNTHETIC) == 0;
968 }
969 };
970
971 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) {
972 //a symbol will be completed from a classfile if (a) symbol has
973 //an associated file object with CLASS kind and (b) the symbol has
974 //not been entered
975 if (origin.classfile != null &&
976 origin.classfile.getKind() == JavaFileObject.Kind.CLASS &&
977 enter.getEnv(origin) == null) {
978 return false;
979 }
980 if (origin == s) {
981 return true;
982 }
983 for (Type t : interfaces(origin.type)) {
984 if (pendingBridges((ClassSymbol)t.tsym, s)) {
985 return true;
986 }
987 }
988 return false;
989 }
990 // </editor-fold>
991
992 /**
993 * Scope filter used to skip methods that should be ignored (such as methods
994 * overridden by j.l.Object) during function interface conversion interface check
995 */
996 class DescriptorFilter implements Predicate<Symbol> {
997
998 TypeSymbol origin;
999
1000 DescriptorFilter(TypeSymbol origin) {
1001 this.origin = origin;
1002 }
1003
1004 @Override
1005 public boolean test(Symbol sym) {
1006 return sym.kind == MTH &&
1007 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT &&
1008 !overridesObjectMethod(origin, sym) &&
1009 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0;
1010 }
1011 }
1012
1013 public boolean isPrimitiveClass(Type t) {
1014 return t != null && t.isPrimitiveClass();
1015 }
1016
1017 // <editor-fold defaultstate="collapsed" desc="isSubtype">
1018 /**
1019 * Is t an unchecked subtype of s?
1020 */
1021 public boolean isSubtypeUnchecked(Type t, Type s) {
1022 return isSubtypeUnchecked(t, s, noWarnings);
1023 }
1024 /**
1025 * Is t an unchecked subtype of s?
1026 */
1027 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) {
1028 boolean result = isSubtypeUncheckedInternal(t, s, true, warn);
1029 if (result) {
1030 checkUnsafeVarargsConversion(t, s, warn);
1031 }
1032 return result;
1033 }
1034 //where
1035 private boolean isSubtypeUncheckedInternal(Type t, Type s, boolean capture, Warner warn) {
1036 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) {
1037 if (((ArrayType)t).elemtype.isPrimitive()) {
1038 return isSameType(elemtype(t), elemtype(s));
1039 } else {
1040 // if T.ref <: S, then T[] <: S[]
1041 Type es = elemtype(s);
1042 Type et = elemtype(t);
1043 if (isPrimitiveClass(et)) {
1044 et = et.referenceProjection();
1045 if (isPrimitiveClass(es))
1046 es = es.referenceProjection(); // V <: V, surely
1047 }
1048 if (!isSubtypeUncheckedInternal(et, es, false, warn))
1049 return false;
1050 return true;
1051 }
1052 } else if (isSubtype(t, s, capture)) {
1053 return true;
1054 } else if (t.hasTag(TYPEVAR)) {
1055 return isSubtypeUncheckedInternal(t.getUpperBound(), s, false, warn);
1056 } else if (!s.isRaw()) {
1057 Type t2 = asSuper(t, s.tsym);
1058 if (t2 != null && t2.isRaw()) {
1059 if (isReifiable(s)) {
1060 warn.silentWarn(LintCategory.UNCHECKED);
1061 } else {
1062 warn.warn(LintCategory.UNCHECKED);
1063 }
1064 return true;
1065 }
1066 }
1067 return false;
1068 }
1069
1070 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) {
1071 if (!t.hasTag(ARRAY) || isReifiable(t)) {
1072 return;
1073 }
1074 ArrayType from = (ArrayType)t;
1075 boolean shouldWarn = false;
1076 switch (s.getTag()) {
1077 case ARRAY:
1078 ArrayType to = (ArrayType)s;
1079 shouldWarn = from.isVarargs() &&
1080 !to.isVarargs() &&
1081 !isReifiable(from);
1082 break;
1083 case CLASS:
1084 shouldWarn = from.isVarargs();
1085 break;
1086 }
1087 if (shouldWarn) {
1088 warn.warn(LintCategory.VARARGS);
1089 }
1090 }
1091
1092 /**
1093 * Is t a subtype of s?<br>
1094 * (not defined for Method and ForAll types)
1095 */
1096 public final boolean isSubtype(Type t, Type s) {
1097 return isSubtype(t, s, true);
1098 }
1099 public final boolean isSubtypeNoCapture(Type t, Type s) {
1100 return isSubtype(t, s, false);
1101 }
1102 public boolean isSubtype(Type t, Type s, boolean capture) {
1103 if (t.equalsIgnoreMetadata(s))
1104 return true;
1105 if (s.isPartial())
1106 return isSuperType(s, t);
1107
1108 if (s.isCompound()) {
1109 for (Type s2 : interfaces(s).prepend(supertype(s))) {
1110 if (!isSubtype(t, s2, capture))
1111 return false;
1112 }
1113 return true;
1114 }
1115
1116 // Generally, if 's' is a lower-bounded type variable, recur on lower bound; but
1117 // for inference variables and intersections, we need to keep 's'
1118 // (see JLS 4.10.2 for intersections and 18.2.3 for inference vars)
1119 if (!t.hasTag(UNDETVAR) && !t.isCompound()) {
1120 // TODO: JDK-8039198, bounds checking sometimes passes in a wildcard as s
1121 Type lower = cvarLowerBound(wildLowerBound(s));
1122 if (s != lower && !lower.hasTag(BOT))
1123 return isSubtype(capture ? capture(t) : t, lower, false);
1124 }
1125
1126 return isSubtype.visit(capture ? capture(t) : t, s);
1127 }
1128 // where
1129 private TypeRelation isSubtype = new TypeRelation()
1130 {
1131 @Override
1132 public Boolean visitType(Type t, Type s) {
1133 switch (t.getTag()) {
1134 case BYTE:
1135 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag()));
1136 case CHAR:
1137 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag()));
1138 case SHORT: case INT: case LONG:
1139 case FLOAT: case DOUBLE:
1140 return t.getTag().isSubRangeOf(s.getTag());
1141 case BOOLEAN: case VOID:
1142 return t.hasTag(s.getTag());
1143 case TYPEVAR:
1144 return isSubtypeNoCapture(t.getUpperBound(), s);
1145 case BOT:
1146 return
1147 s.hasTag(BOT) || (s.hasTag(CLASS) && !isPrimitiveClass(s)) ||
1148 s.hasTag(ARRAY) || s.hasTag(TYPEVAR);
1149 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495)
1150 case NONE:
1151 return false;
1152 default:
1153 throw new AssertionError("isSubtype " + t.getTag());
1154 }
1155 }
1156
1157 private Set<TypePair> cache = new HashSet<>();
1158
1159 private boolean containsTypeRecursive(Type t, Type s) {
1160 TypePair pair = new TypePair(t, s);
1161 if (cache.add(pair)) {
1162 try {
1163 return containsType(t.getTypeArguments(),
1164 s.getTypeArguments());
1165 } finally {
1166 cache.remove(pair);
1167 }
1168 } else {
1169 return containsType(t.getTypeArguments(),
1170 rewriteSupers(s).getTypeArguments());
1171 }
1172 }
1173
1174 private Type rewriteSupers(Type t) {
1175 if (!t.isParameterized())
1176 return t;
1177 ListBuffer<Type> from = new ListBuffer<>();
1178 ListBuffer<Type> to = new ListBuffer<>();
1179 adaptSelf(t, from, to);
1180 if (from.isEmpty())
1181 return t;
1182 ListBuffer<Type> rewrite = new ListBuffer<>();
1183 boolean changed = false;
1184 for (Type orig : to.toList()) {
1185 Type s = rewriteSupers(orig);
1186 if (s.isSuperBound() && !s.isExtendsBound()) {
1187 s = new WildcardType(syms.objectType,
1188 BoundKind.UNBOUND,
1189 syms.boundClass,
1190 s.getMetadata());
1191 changed = true;
1192 } else if (s != orig) {
1193 s = new WildcardType(wildUpperBound(s),
1194 BoundKind.EXTENDS,
1195 syms.boundClass,
1196 s.getMetadata());
1197 changed = true;
1198 }
1199 rewrite.append(s);
1200 }
1201 if (changed)
1202 return subst(t.tsym.type, from.toList(), rewrite.toList());
1203 else
1204 return t;
1205 }
1206
1207 @Override
1208 public Boolean visitClassType(ClassType t, Type s) {
1209 Type sup = asSuper(t, s.tsym);
1210 if (sup == null) return false;
1211 // If t is an intersection, sup might not be a class type
1212 if (!sup.hasTag(CLASS)) return isSubtypeNoCapture(sup, s);
1213 return sup.tsym == s.tsym
1214 && (t.tsym != s.tsym ||
1215 (t.isReferenceProjection() == s.isReferenceProjection() && t.isValueProjection() == s.isValueProjection()))
1216 // Check type variable containment
1217 && (!s.isParameterized() || containsTypeRecursive(s, sup))
1218 && isSubtypeNoCapture(sup.getEnclosingType(),
1219 s.getEnclosingType());
1220 }
1221
1222 @Override
1223 public Boolean visitArrayType(ArrayType t, Type s) {
1224 if (s.hasTag(ARRAY)) {
1225 if (t.elemtype.isPrimitive())
1226 return isSameType(t.elemtype, elemtype(s));
1227 else {
1228 // if T.ref <: S, then T[] <: S[]
1229 Type es = elemtype(s);
1230 Type et = elemtype(t);
1231 if (isPrimitiveClass(et)) {
1232 et = et.referenceProjection();
1233 if (isPrimitiveClass(es))
1234 es = es.referenceProjection(); // V <: V, surely
1235 }
1236 return isSubtypeNoCapture(et, es);
1237 }
1238 }
1239
1240 if (s.hasTag(CLASS)) {
1241 Name sname = s.tsym.getQualifiedName();
1242 return sname == names.java_lang_Object
1243 || sname == names.java_lang_Cloneable
1244 || sname == names.java_io_Serializable
1245 || sname == names.java_lang_IdentityObject;
1246 }
1247
1248 return false;
1249 }
1250
1251 @Override
1252 public Boolean visitUndetVar(UndetVar t, Type s) {
1253 //todo: test against origin needed? or replace with substitution?
1254 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1255 return true;
1256 } else if (s.hasTag(BOT)) {
1257 //if 's' is 'null' there's no instantiated type U for which
1258 //U <: s (but 'null' itself, which is not a valid type)
1259 return false;
1260 }
1261
1262 t.addBound(InferenceBound.UPPER, s, Types.this);
1263 return true;
1264 }
1265
1266 @Override
1267 public Boolean visitErrorType(ErrorType t, Type s) {
1268 return true;
1269 }
1270 };
1271
1272 /**
1273 * Is t a subtype of every type in given list `ts'?<br>
1274 * (not defined for Method and ForAll types)<br>
1275 * Allows unchecked conversions.
1276 */
1277 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) {
1278 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
1279 if (!isSubtypeUnchecked(t, l.head, warn))
1280 return false;
1281 return true;
1282 }
1283
1284 /**
1285 * Are corresponding elements of ts subtypes of ss? If lists are
1286 * of different length, return false.
1287 */
1288 public boolean isSubtypes(List<Type> ts, List<Type> ss) {
1289 while (ts.tail != null && ss.tail != null
1290 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1291 isSubtype(ts.head, ss.head)) {
1292 ts = ts.tail;
1293 ss = ss.tail;
1294 }
1295 return ts.tail == null && ss.tail == null;
1296 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1297 }
1298
1299 /**
1300 * Are corresponding elements of ts subtypes of ss, allowing
1301 * unchecked conversions? If lists are of different length,
1302 * return false.
1303 **/
1304 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) {
1305 while (ts.tail != null && ss.tail != null
1306 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1307 isSubtypeUnchecked(ts.head, ss.head, warn)) {
1308 ts = ts.tail;
1309 ss = ss.tail;
1310 }
1311 return ts.tail == null && ss.tail == null;
1312 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1313 }
1314 // </editor-fold>
1315
1316 // <editor-fold defaultstate="collapsed" desc="isSuperType">
1317 /**
1318 * Is t a supertype of s?
1319 */
1320 public boolean isSuperType(Type t, Type s) {
1321 switch (t.getTag()) {
1322 case ERROR:
1323 return true;
1324 case UNDETVAR: {
1325 UndetVar undet = (UndetVar)t;
1326 if (t == s ||
1327 undet.qtype == s ||
1328 s.hasTag(ERROR) ||
1329 s.hasTag(BOT)) {
1330 return true;
1331 }
1332 undet.addBound(InferenceBound.LOWER, s, this);
1333 return true;
1334 }
1335 default:
1336 return isSubtype(s, t);
1337 }
1338 }
1339 // </editor-fold>
1340
1341 // <editor-fold defaultstate="collapsed" desc="isSameType">
1342 /**
1343 * Are corresponding elements of the lists the same type? If
1344 * lists are of different length, return false.
1345 */
1346 public boolean isSameTypes(List<Type> ts, List<Type> ss) {
1347 while (ts.tail != null && ss.tail != null
1348 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1349 isSameType(ts.head, ss.head)) {
1350 ts = ts.tail;
1351 ss = ss.tail;
1352 }
1353 return ts.tail == null && ss.tail == null;
1354 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1355 }
1356
1357 /**
1358 * A polymorphic signature method (JLS 15.12.3) is a method that
1359 * (i) is declared in the java.lang.invoke.MethodHandle/VarHandle classes;
1360 * (ii) takes a single variable arity parameter;
1361 * (iii) whose declared type is Object[];
1362 * (iv) has any return type, Object signifying a polymorphic return type; and
1363 * (v) is native.
1364 */
1365 public boolean isSignaturePolymorphic(MethodSymbol msym) {
1366 List<Type> argtypes = msym.type.getParameterTypes();
1367 return (msym.flags_field & NATIVE) != 0 &&
1368 (msym.owner == syms.methodHandleType.tsym || msym.owner == syms.varHandleType.tsym) &&
1369 argtypes.length() == 1 &&
1370 argtypes.head.hasTag(TypeTag.ARRAY) &&
1371 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym;
1372 }
1373
1374 /**
1375 * Is t the same type as s?
1376 */
1377 public boolean isSameType(Type t, Type s) {
1378 return isSameTypeVisitor.visit(t, s);
1379 }
1380 // where
1381
1382 /**
1383 * Type-equality relation - type variables are considered
1384 * equals if they share the same object identity.
1385 */
1386 TypeRelation isSameTypeVisitor = new TypeRelation() {
1387
1388 public Boolean visitType(Type t, Type s) {
1389 if (t.equalsIgnoreMetadata(s))
1390 return true;
1391
1392 if (s.isPartial())
1393 return visit(s, t);
1394
1395 switch (t.getTag()) {
1396 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1397 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE:
1398 return t.hasTag(s.getTag());
1399 case TYPEVAR: {
1400 if (s.hasTag(TYPEVAR)) {
1401 //type-substitution does not preserve type-var types
1402 //check that type var symbols and bounds are indeed the same
1403 return t == s;
1404 }
1405 else {
1406 //special case for s == ? super X, where upper(s) = u
1407 //check that u == t, where u has been set by Type.withTypeVar
1408 return s.isSuperBound() &&
1409 !s.isExtendsBound() &&
1410 visit(t, wildUpperBound(s));
1411 }
1412 }
1413 default:
1414 throw new AssertionError("isSameType " + t.getTag());
1415 }
1416 }
1417
1418 @Override
1419 public Boolean visitWildcardType(WildcardType t, Type s) {
1420 if (!s.hasTag(WILDCARD)) {
1421 return false;
1422 } else {
1423 WildcardType t2 = (WildcardType)s;
1424 return (t.kind == t2.kind || (t.isExtendsBound() && s.isExtendsBound())) &&
1425 isSameType(t.type, t2.type);
1426 }
1427 }
1428
1429 @Override
1430 public Boolean visitClassType(ClassType t, Type s) {
1431 if (t == s)
1432 return true;
1433
1434 if (s.isPartial())
1435 return visit(s, t);
1436
1437 if (s.isSuperBound() && !s.isExtendsBound())
1438 return visit(t, wildUpperBound(s)) && visit(t, wildLowerBound(s));
1439
1440 if (t.isCompound() && s.isCompound()) {
1441 if (!visit(supertype(t), supertype(s)))
1442 return false;
1443
1444 Map<Symbol,Type> tMap = new HashMap<>();
1445 for (Type ti : interfaces(t)) {
1446 if (tMap.containsKey(ti)) {
1447 throw new AssertionError("Malformed intersection");
1448 }
1449 tMap.put(ti.tsym, ti);
1450 }
1451 for (Type si : interfaces(s)) {
1452 if (!tMap.containsKey(si.tsym))
1453 return false;
1454 Type ti = tMap.remove(si.tsym);
1455 if (!visit(ti, si))
1456 return false;
1457 }
1458 return tMap.isEmpty();
1459 }
1460 return t.tsym == s.tsym
1461 && t.isReferenceProjection() == s.isReferenceProjection()
1462 && t.isValueProjection() == s.isValueProjection()
1463 && visit(getEnclosingType(t), getEnclosingType(s))
1464 && containsTypeEquivalent(t.getTypeArguments(), s.getTypeArguments());
1465 }
1466 // where
1467 private Type getEnclosingType(Type t) {
1468 Type et = t.getEnclosingType();
1469 if (et.isReferenceProjection()) {
1470 et = et.asValueType();
1471 }
1472 return et;
1473 }
1474
1475 @Override
1476 public Boolean visitArrayType(ArrayType t, Type s) {
1477 if (t == s)
1478 return true;
1479
1480 if (s.isPartial())
1481 return visit(s, t);
1482
1483 return s.hasTag(ARRAY)
1484 && containsTypeEquivalent(t.elemtype, elemtype(s));
1485 }
1486
1487 @Override
1488 public Boolean visitMethodType(MethodType t, Type s) {
1489 // isSameType for methods does not take thrown
1490 // exceptions into account!
1491 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType());
1492 }
1493
1494 @Override
1495 public Boolean visitPackageType(PackageType t, Type s) {
1496 return t == s;
1497 }
1498
1499 @Override
1500 public Boolean visitForAll(ForAll t, Type s) {
1501 if (!s.hasTag(FORALL)) {
1502 return false;
1503 }
1504
1505 ForAll forAll = (ForAll)s;
1506 return hasSameBounds(t, forAll)
1507 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
1508 }
1509
1510 @Override
1511 public Boolean visitUndetVar(UndetVar t, Type s) {
1512 if (s.hasTag(WILDCARD)) {
1513 // FIXME, this might be leftovers from before capture conversion
1514 return false;
1515 }
1516
1517 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1518 return true;
1519 }
1520
1521 t.addBound(InferenceBound.EQ, s, Types.this);
1522
1523 return true;
1524 }
1525
1526 @Override
1527 public Boolean visitErrorType(ErrorType t, Type s) {
1528 return true;
1529 }
1530 };
1531
1532 // </editor-fold>
1533
1534 // <editor-fold defaultstate="collapsed" desc="Contains Type">
1535 public boolean containedBy(Type t, Type s) {
1536 switch (t.getTag()) {
1537 case UNDETVAR:
1538 if (s.hasTag(WILDCARD)) {
1539 UndetVar undetvar = (UndetVar)t;
1540 WildcardType wt = (WildcardType)s;
1541 switch(wt.kind) {
1542 case UNBOUND:
1543 break;
1544 case EXTENDS: {
1545 Type bound = wildUpperBound(s);
1546 undetvar.addBound(InferenceBound.UPPER, bound, this);
1547 break;
1548 }
1549 case SUPER: {
1550 Type bound = wildLowerBound(s);
1551 undetvar.addBound(InferenceBound.LOWER, bound, this);
1552 break;
1553 }
1554 }
1555 return true;
1556 } else {
1557 return isSameType(t, s);
1558 }
1559 case ERROR:
1560 return true;
1561 default:
1562 return containsType(s, t);
1563 }
1564 }
1565
1566 boolean containsType(List<Type> ts, List<Type> ss) {
1567 while (ts.nonEmpty() && ss.nonEmpty()
1568 && containsType(ts.head, ss.head)) {
1569 ts = ts.tail;
1570 ss = ss.tail;
1571 }
1572 return ts.isEmpty() && ss.isEmpty();
1573 }
1574
1575 /**
1576 * Check if t contains s.
1577 *
1578 * <p>T contains S if:
1579 *
1580 * <p>{@code L(T) <: L(S) && U(S) <: U(T)}
1581 *
1582 * <p>This relation is only used by ClassType.isSubtype(), that
1583 * is,
1584 *
1585 * <p>{@code C<S> <: C<T> if T contains S.}
1586 *
1587 * <p>Because of F-bounds, this relation can lead to infinite
1588 * recursion. Thus we must somehow break that recursion. Notice
1589 * that containsType() is only called from ClassType.isSubtype().
1590 * Since the arguments have already been checked against their
1591 * bounds, we know:
1592 *
1593 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)}
1594 *
1595 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)}
1596 *
1597 * @param t a type
1598 * @param s a type
1599 */
1600 public boolean containsType(Type t, Type s) {
1601 return containsType.visit(t, s);
1602 }
1603 // where
1604 private TypeRelation containsType = new TypeRelation() {
1605
1606 public Boolean visitType(Type t, Type s) {
1607 if (s.isPartial())
1608 return containedBy(s, t);
1609 else
1610 return isSameType(t, s);
1611 }
1612
1613 // void debugContainsType(WildcardType t, Type s) {
1614 // System.err.println();
1615 // System.err.format(" does %s contain %s?%n", t, s);
1616 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n",
1617 // wildUpperBound(s), s, t, wildUpperBound(t),
1618 // t.isSuperBound()
1619 // || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t)));
1620 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n",
1621 // wildLowerBound(t), t, s, wildLowerBound(s),
1622 // t.isExtendsBound()
1623 // || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s)));
1624 // System.err.println();
1625 // }
1626
1627 @Override
1628 public Boolean visitWildcardType(WildcardType t, Type s) {
1629 if (s.isPartial())
1630 return containedBy(s, t);
1631 else {
1632 // debugContainsType(t, s);
1633
1634 // ----------------------------------- Unspecified behavior ----------------
1635
1636 /* If a primitive class V implements an interface I, then does "? extends I" contain V?
1637 It seems widening must be applied here to answer yes to compile some common code
1638 patterns.
1639 */
1640
1641 // ---------------------------------------------------------------------------
1642 return isSameWildcard(t, s)
1643 || isCaptureOf(s, t)
1644 || ((t.isExtendsBound() || isSubtypeNoCapture(wildLowerBound(t), wildLowerBound(s))) &&
1645 (t.isSuperBound() || isSubtypeNoCapture(wildUpperBound(s), wildUpperBound(t))));
1646 }
1647 }
1648
1649 @Override
1650 public Boolean visitUndetVar(UndetVar t, Type s) {
1651 if (!s.hasTag(WILDCARD)) {
1652 return isSameType(t, s);
1653 } else {
1654 return false;
1655 }
1656 }
1657
1658 @Override
1659 public Boolean visitErrorType(ErrorType t, Type s) {
1660 return true;
1661 }
1662 };
1663
1664 public boolean isCaptureOf(Type s, WildcardType t) {
1665 if (!s.hasTag(TYPEVAR) || !((TypeVar)s).isCaptured())
1666 return false;
1667 return isSameWildcard(t, ((CapturedType)s).wildcard);
1668 }
1669
1670 public boolean isSameWildcard(WildcardType t, Type s) {
1671 if (!s.hasTag(WILDCARD))
1672 return false;
1673 WildcardType w = (WildcardType)s;
1674 return w.kind == t.kind && w.type == t.type;
1675 }
1676
1677 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) {
1678 while (ts.nonEmpty() && ss.nonEmpty()
1679 && containsTypeEquivalent(ts.head, ss.head)) {
1680 ts = ts.tail;
1681 ss = ss.tail;
1682 }
1683 return ts.isEmpty() && ss.isEmpty();
1684 }
1685 // </editor-fold>
1686
1687 // <editor-fold defaultstate="collapsed" desc="isCastable">
1688 public boolean isCastable(Type t, Type s) {
1689 return isCastable(t, s, noWarnings);
1690 }
1691
1692 /**
1693 * Is t castable to s?<br>
1694 * s is assumed to be an erased type.<br>
1695 * (not defined for Method and ForAll types).
1696 */
1697 public boolean isCastable(Type t, Type s, Warner warn) {
1698 // if same type
1699 if (t == s)
1700 return true;
1701 // if one of the types is primitive
1702 if (t.isPrimitive() != s.isPrimitive()) {
1703 t = skipTypeVars(t, false);
1704 return (isConvertible(t, s, warn)
1705 || (s.isPrimitive() &&
1706 isSubtype(boxedClass(s).type, t)));
1707 }
1708 boolean result;
1709 if (warn != warnStack.head) {
1710 try {
1711 warnStack = warnStack.prepend(warn);
1712 checkUnsafeVarargsConversion(t, s, warn);
1713 result = isCastable.visit(t,s);
1714 } finally {
1715 warnStack = warnStack.tail;
1716 }
1717 } else {
1718 result = isCastable.visit(t,s);
1719 }
1720 if (result && t.hasTag(CLASS) && t.tsym.kind.matches(Kinds.KindSelector.TYP)
1721 && s.hasTag(CLASS) && s.tsym.kind.matches(Kinds.KindSelector.TYP)
1722 && (t.tsym.isSealed() || s.tsym.isSealed())) {
1723 return (t.isCompound() || s.isCompound()) ?
1724 false :
1725 !areDisjoint((ClassSymbol)t.tsym, (ClassSymbol)s.tsym);
1726 }
1727 return result;
1728 }
1729 // where
1730 private boolean areDisjoint(ClassSymbol ts, ClassSymbol ss) {
1731 if (isSubtype(erasure(ts.type), erasure(ss.type))) {
1732 return false;
1733 }
1734 // if both are classes or both are interfaces, shortcut
1735 if (ts.isInterface() == ss.isInterface() && isSubtype(erasure(ss.type), erasure(ts.type))) {
1736 return false;
1737 }
1738 if (ts.isInterface() && !ss.isInterface()) {
1739 /* so ts is interface but ss is a class
1740 * an interface is disjoint from a class if the class is disjoint form the interface
1741 */
1742 return areDisjoint(ss, ts);
1743 }
1744 // a final class that is not subtype of ss is disjoint
1745 if (!ts.isInterface() && ts.isFinal()) {
1746 return true;
1747 }
1748 // if at least one is sealed
1749 if (ts.isSealed() || ss.isSealed()) {
1750 // permitted subtypes have to be disjoint with the other symbol
1751 ClassSymbol sealedOne = ts.isSealed() ? ts : ss;
1752 ClassSymbol other = sealedOne == ts ? ss : ts;
1753 return sealedOne.permitted.stream().allMatch(sym -> areDisjoint((ClassSymbol)sym, other));
1754 }
1755 return false;
1756 }
1757
1758 private TypeRelation isCastable = new TypeRelation() {
1759
1760 public Boolean visitType(Type t, Type s) {
1761 if (s.hasTag(ERROR) || t.hasTag(NONE))
1762 return true;
1763
1764 switch (t.getTag()) {
1765 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1766 case DOUBLE:
1767 return s.isNumeric();
1768 case BOOLEAN:
1769 return s.hasTag(BOOLEAN);
1770 case VOID:
1771 return false;
1772 case BOT:
1773 return isSubtype(t, s);
1774 default:
1775 throw new AssertionError();
1776 }
1777 }
1778
1779 @Override
1780 public Boolean visitWildcardType(WildcardType t, Type s) {
1781 return isCastable(wildUpperBound(t), s, warnStack.head);
1782 }
1783
1784 @Override
1785 public Boolean visitClassType(ClassType t, Type s) {
1786 if (s.hasTag(ERROR) || (s.hasTag(BOT) && !isPrimitiveClass(t)))
1787 return true;
1788
1789 if (s.hasTag(TYPEVAR)) {
1790 if (isCastable(t, s.getUpperBound(), noWarnings)) {
1791 warnStack.head.warn(LintCategory.UNCHECKED);
1792 return true;
1793 } else {
1794 return false;
1795 }
1796 }
1797
1798 if (t.isCompound() || s.isCompound()) {
1799 return !t.isCompound() ?
1800 visitCompoundType((ClassType)s, t, true) :
1801 visitCompoundType(t, s, false);
1802 }
1803
1804 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) {
1805 if (isPrimitiveClass(t)) {
1806 // (s) Value ? == (s) Value.ref
1807 t = t.referenceProjection();
1808 }
1809 if (isPrimitiveClass(s)) {
1810 // (Value) t ? == (Value.ref) t
1811 s = s.referenceProjection();
1812 }
1813 boolean upcast;
1814 if ((upcast = isSubtype(erasure(t), erasure(s)))
1815 || isSubtype(erasure(s), erasure(t))) {
1816 if (!upcast && s.hasTag(ARRAY)) {
1817 if (!isReifiable(s))
1818 warnStack.head.warn(LintCategory.UNCHECKED);
1819 return true;
1820 } else if (s.isRaw()) {
1821 return true;
1822 } else if (t.isRaw()) {
1823 if (!isUnbounded(s))
1824 warnStack.head.warn(LintCategory.UNCHECKED);
1825 return true;
1826 }
1827 // Assume |a| <: |b|
1828 final Type a = upcast ? t : s;
1829 final Type b = upcast ? s : t;
1830 final boolean HIGH = true;
1831 final boolean LOW = false;
1832 final boolean DONT_REWRITE_TYPEVARS = false;
1833 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS);
1834 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS);
1835 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS);
1836 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS);
1837 Type lowSub = asSub(bLow, aLow.tsym);
1838 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1839 if (highSub == null) {
1840 final boolean REWRITE_TYPEVARS = true;
1841 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS);
1842 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS);
1843 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS);
1844 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS);
1845 lowSub = asSub(bLow, aLow.tsym);
1846 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1847 }
1848 if (highSub != null) {
1849 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) {
1850 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym);
1851 }
1852 if (!disjointTypes(aHigh.allparams(), highSub.allparams())
1853 && !disjointTypes(aHigh.allparams(), lowSub.allparams())
1854 && !disjointTypes(aLow.allparams(), highSub.allparams())
1855 && !disjointTypes(aLow.allparams(), lowSub.allparams())) {
1856 if (upcast ? giveWarning(a, b) :
1857 giveWarning(b, a))
1858 warnStack.head.warn(LintCategory.UNCHECKED);
1859 return true;
1860 }
1861 }
1862 if (isReifiable(s))
1863 return isSubtypeUnchecked(a, b);
1864 else
1865 return isSubtypeUnchecked(a, b, warnStack.head);
1866 }
1867
1868 // Sidecast
1869 if (s.hasTag(CLASS)) {
1870 if ((s.tsym.flags() & INTERFACE) != 0) {
1871 return ((t.tsym.flags() & FINAL) == 0)
1872 ? sideCast(t, s, warnStack.head)
1873 : sideCastFinal(t, s, warnStack.head);
1874 } else if ((t.tsym.flags() & INTERFACE) != 0) {
1875 return ((s.tsym.flags() & FINAL) == 0)
1876 ? sideCast(t, s, warnStack.head)
1877 : sideCastFinal(t, s, warnStack.head);
1878 } else {
1879 // unrelated class types
1880 return false;
1881 }
1882 }
1883 }
1884 return false;
1885 }
1886
1887 boolean visitCompoundType(ClassType ct, Type s, boolean reverse) {
1888 Warner warn = noWarnings;
1889 for (Type c : directSupertypes(ct)) {
1890 warn.clear();
1891 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn))
1892 return false;
1893 }
1894 if (warn.hasLint(LintCategory.UNCHECKED))
1895 warnStack.head.warn(LintCategory.UNCHECKED);
1896 return true;
1897 }
1898
1899 @Override
1900 public Boolean visitArrayType(ArrayType t, Type s) {
1901 switch (s.getTag()) {
1902 case ERROR:
1903 case BOT:
1904 return true;
1905 case TYPEVAR:
1906 if (isCastable(s, t, noWarnings)) {
1907 warnStack.head.warn(LintCategory.UNCHECKED);
1908 return true;
1909 } else {
1910 return false;
1911 }
1912 case CLASS:
1913 return isSubtype(t, s);
1914 case ARRAY:
1915 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) {
1916 return elemtype(t).hasTag(elemtype(s).getTag());
1917 } else {
1918 Type et = elemtype(t);
1919 Type es = elemtype(s);
1920 if (!visit(et, es))
1921 return false;
1922 return true;
1923 }
1924 default:
1925 return false;
1926 }
1927 }
1928
1929 @Override
1930 public Boolean visitTypeVar(TypeVar t, Type s) {
1931 switch (s.getTag()) {
1932 case ERROR:
1933 case BOT:
1934 return true;
1935 case TYPEVAR:
1936 if (isSubtype(t, s)) {
1937 return true;
1938 } else if (isCastable(t.getUpperBound(), s, noWarnings)) {
1939 warnStack.head.warn(LintCategory.UNCHECKED);
1940 return true;
1941 } else {
1942 return false;
1943 }
1944 default:
1945 return isCastable(t.getUpperBound(), s, warnStack.head);
1946 }
1947 }
1948
1949 @Override
1950 public Boolean visitErrorType(ErrorType t, Type s) {
1951 return true;
1952 }
1953 };
1954 // </editor-fold>
1955
1956 // <editor-fold defaultstate="collapsed" desc="disjointTypes">
1957 public boolean disjointTypes(List<Type> ts, List<Type> ss) {
1958 while (ts.tail != null && ss.tail != null) {
1959 if (disjointType(ts.head, ss.head)) return true;
1960 ts = ts.tail;
1961 ss = ss.tail;
1962 }
1963 return false;
1964 }
1965
1966 /**
1967 * Two types or wildcards are considered disjoint if it can be
1968 * proven that no type can be contained in both. It is
1969 * conservative in that it is allowed to say that two types are
1970 * not disjoint, even though they actually are.
1971 *
1972 * The type {@code C<X>} is castable to {@code C<Y>} exactly if
1973 * {@code X} and {@code Y} are not disjoint.
1974 */
1975 public boolean disjointType(Type t, Type s) {
1976 return disjointType.visit(t, s);
1977 }
1978 // where
1979 private TypeRelation disjointType = new TypeRelation() {
1980
1981 private Set<TypePair> cache = new HashSet<>();
1982
1983 @Override
1984 public Boolean visitType(Type t, Type s) {
1985 if (s.hasTag(WILDCARD))
1986 return visit(s, t);
1987 else
1988 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t);
1989 }
1990
1991 private boolean isCastableRecursive(Type t, Type s) {
1992 TypePair pair = new TypePair(t, s);
1993 if (cache.add(pair)) {
1994 try {
1995 return Types.this.isCastable(t, s);
1996 } finally {
1997 cache.remove(pair);
1998 }
1999 } else {
2000 return true;
2001 }
2002 }
2003
2004 private boolean notSoftSubtypeRecursive(Type t, Type s) {
2005 TypePair pair = new TypePair(t, s);
2006 if (cache.add(pair)) {
2007 try {
2008 return Types.this.notSoftSubtype(t, s);
2009 } finally {
2010 cache.remove(pair);
2011 }
2012 } else {
2013 return false;
2014 }
2015 }
2016
2017 @Override
2018 public Boolean visitWildcardType(WildcardType t, Type s) {
2019 if (t.isUnbound())
2020 return false;
2021
2022 if (!s.hasTag(WILDCARD)) {
2023 if (t.isExtendsBound())
2024 return notSoftSubtypeRecursive(s, t.type);
2025 else
2026 return notSoftSubtypeRecursive(t.type, s);
2027 }
2028
2029 if (s.isUnbound())
2030 return false;
2031
2032 if (t.isExtendsBound()) {
2033 if (s.isExtendsBound())
2034 return !isCastableRecursive(t.type, wildUpperBound(s));
2035 else if (s.isSuperBound())
2036 return notSoftSubtypeRecursive(wildLowerBound(s), t.type);
2037 } else if (t.isSuperBound()) {
2038 if (s.isExtendsBound())
2039 return notSoftSubtypeRecursive(t.type, wildUpperBound(s));
2040 }
2041 return false;
2042 }
2043 };
2044 // </editor-fold>
2045
2046 // <editor-fold defaultstate="collapsed" desc="cvarLowerBounds">
2047 public List<Type> cvarLowerBounds(List<Type> ts) {
2048 return ts.map(cvarLowerBoundMapping);
2049 }
2050 private final TypeMapping<Void> cvarLowerBoundMapping = new TypeMapping<Void>() {
2051 @Override
2052 public Type visitCapturedType(CapturedType t, Void _unused) {
2053 return cvarLowerBound(t);
2054 }
2055 };
2056 // </editor-fold>
2057
2058 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype">
2059 /**
2060 * This relation answers the question: is impossible that
2061 * something of type `t' can be a subtype of `s'? This is
2062 * different from the question "is `t' not a subtype of `s'?"
2063 * when type variables are involved: Integer is not a subtype of T
2064 * where {@code <T extends Number>} but it is not true that Integer cannot
2065 * possibly be a subtype of T.
2066 */
2067 public boolean notSoftSubtype(Type t, Type s) {
2068 if (t == s) return false;
2069 if (t.hasTag(TYPEVAR)) {
2070 TypeVar tv = (TypeVar) t;
2071 return !isCastable(tv.getUpperBound(),
2072 relaxBound(s),
2073 noWarnings);
2074 }
2075 if (!s.hasTag(WILDCARD))
2076 s = cvarUpperBound(s);
2077
2078 return !isSubtype(t, relaxBound(s));
2079 }
2080
2081 private Type relaxBound(Type t) {
2082 return (t.hasTag(TYPEVAR)) ?
2083 rewriteQuantifiers(skipTypeVars(t, false), true, true) :
2084 t;
2085 }
2086 // </editor-fold>
2087
2088 // <editor-fold defaultstate="collapsed" desc="isReifiable">
2089 public boolean isReifiable(Type t) {
2090 return isReifiable.visit(t);
2091 }
2092 // where
2093 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() {
2094
2095 public Boolean visitType(Type t, Void ignored) {
2096 return true;
2097 }
2098
2099 @Override
2100 public Boolean visitClassType(ClassType t, Void ignored) {
2101 if (t.isCompound())
2102 return false;
2103 else {
2104 if (!t.isParameterized())
2105 return true;
2106
2107 for (Type param : t.allparams()) {
2108 if (!param.isUnbound())
2109 return false;
2110 }
2111 return true;
2112 }
2113 }
2114
2115 @Override
2116 public Boolean visitArrayType(ArrayType t, Void ignored) {
2117 return visit(t.elemtype);
2118 }
2119
2120 @Override
2121 public Boolean visitTypeVar(TypeVar t, Void ignored) {
2122 return false;
2123 }
2124 };
2125 // </editor-fold>
2126
2127 // <editor-fold defaultstate="collapsed" desc="Array Utils">
2128 public boolean isArray(Type t) {
2129 while (t.hasTag(WILDCARD))
2130 t = wildUpperBound(t);
2131 return t.hasTag(ARRAY);
2132 }
2133
2134 /**
2135 * The element type of an array.
2136 */
2137 public Type elemtype(Type t) {
2138 switch (t.getTag()) {
2139 case WILDCARD:
2140 return elemtype(wildUpperBound(t));
2141 case ARRAY:
2142 return ((ArrayType)t).elemtype;
2143 case FORALL:
2144 return elemtype(((ForAll)t).qtype);
2145 case ERROR:
2146 return t;
2147 default:
2148 return null;
2149 }
2150 }
2151
2152 public Type elemtypeOrType(Type t) {
2153 Type elemtype = elemtype(t);
2154 return elemtype != null ?
2155 elemtype :
2156 t;
2157 }
2158
2159 /**
2160 * Mapping to take element type of an arraytype
2161 */
2162 private TypeMapping<Void> elemTypeFun = new TypeMapping<Void>() {
2163 @Override
2164 public Type visitArrayType(ArrayType t, Void _unused) {
2165 return t.elemtype;
2166 }
2167
2168 @Override
2169 public Type visitTypeVar(TypeVar t, Void _unused) {
2170 return visit(skipTypeVars(t, false));
2171 }
2172 };
2173
2174 /**
2175 * The number of dimensions of an array type.
2176 */
2177 public int dimensions(Type t) {
2178 int result = 0;
2179 while (t.hasTag(ARRAY)) {
2180 result++;
2181 t = elemtype(t);
2182 }
2183 return result;
2184 }
2185
2186 /**
2187 * Returns an ArrayType with the component type t
2188 *
2189 * @param t The component type of the ArrayType
2190 * @return the ArrayType for the given component
2191 */
2192 public ArrayType makeArrayType(Type t) {
2193 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) {
2194 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString());
2195 }
2196 return new ArrayType(t, syms.arrayClass);
2197 }
2198 // </editor-fold>
2199
2200 // <editor-fold defaultstate="collapsed" desc="asSuper">
2201 /**
2202 * Return the (most specific) base type of t that starts with the
2203 * given symbol. If none exists, return null.
2204 *
2205 * Caveat Emptor: Since javac represents the class of all arrays with a singleton
2206 * symbol Symtab.arrayClass, which by being a singleton cannot hold any discriminant,
2207 * this method could yield surprising answers when invoked on arrays. For example when
2208 * invoked with t being byte [] and sym being t.sym itself, asSuper would answer null.
2209 *
2210 * Further caveats in Valhalla: There are two "hazards" we need to watch out for when using
2211 * this method.
2212 *
2213 * 1. Since Foo.ref and Foo.val share the same symbol, that of Foo.class, a call to
2214 * asSuper(Foo.ref.type, Foo.val.type.tsym) would return non-null. This MAY NOT BE correct
2215 * depending on the call site. Foo.val is NOT a super type of Foo.ref either in the language
2216 * model or in the VM's world view. An example of such an hazardous call used to exist in
2217 * Gen.visitTypeCast. When we emit code for (Foo) Foo.ref.instance a check for whether we
2218 * really need the cast cannot/shouldn't be gated on
2219 *
2220 * asSuper(tree.expr.type, tree.clazz.type.tsym) == null)
2221 *
2222 * but use !types.isSubtype(tree.expr.type, tree.clazz.type) which operates in terms of
2223 * types. When we operate in terms of symbols, there is a loss of type information leading
2224 * to a hazard. Whether a call to asSuper should be transformed into a isSubtype call is
2225 * tricky. isSubtype returns just a boolean while asSuper returns richer information which
2226 * may be required at the call site. Also where the concerned symbol corresponds to a
2227 * generic class, an asSuper call cannot be conveniently rewritten as an isSubtype call
2228 * (see that asSuper(ArrayList<String>.type, List<T>.tsym) != null while
2229 * isSubType(ArrayList<String>.type, List<T>.type) is false;) So care needs to be exercised.
2230 *
2231 * 2. Given a primitive class Foo, a call to asSuper(Foo.type, SuperclassOfFoo.tsym) and/or
2232 * a call to asSuper(Foo.type, SuperinterfaceOfFoo.tsym) would answer null. In many places
2233 * that is NOT what we want. An example of such a hazardous call used to occur in
2234 * Attr.visitForeachLoop when checking to make sure the for loop's control variable of a type
2235 * that implements Iterable: viz: types.asSuper(exprType, syms.iterableType.tsym);
2236 * These hazardous calls should be rewritten as
2237 * types.asSuper(exprType.referenceProjectionOrSelf(), syms.iterableType.tsym); instead.
2238 *
2239 * @param t a type
2240 * @param sym a symbol
2241 */
2242 public Type asSuper(Type t, Symbol sym) {
2243 /* Some examples:
2244 *
2245 * (Enum<E>, Comparable) => Comparable<E>
2246 * (c.s.s.d.AttributeTree.ValueKind, Enum) => Enum<c.s.s.d.AttributeTree.ValueKind>
2247 * (c.s.s.t.ExpressionTree, c.s.s.t.Tree) => c.s.s.t.Tree
2248 * (j.u.List<capture#160 of ? extends c.s.s.d.DocTree>, Iterable) =>
2249 * Iterable<capture#160 of ? extends c.s.s.d.DocTree>
2250 */
2251
2252 if (isPrimitiveClass(t)) {
2253 // No man may be an island, but the bell tolls for a value.
2254 return t.tsym == sym ? t : null;
2255 }
2256
2257 if (sym.type == syms.objectType) { //optimization
2258 return syms.objectType;
2259 }
2260 if (sym == syms.identityObjectType.tsym) {
2261 // IdentityObject is a super interface of every concrete identity class other than jlO
2262 if (t.tsym == syms.objectType.tsym)
2263 return null;
2264 if (t.hasTag(ARRAY))
2265 return syms.identityObjectType;
2266 if (t.hasTag(CLASS) && !t.tsym.isPrimitiveClass() && !t.tsym.isInterface() && !t.tsym.isAbstract()) {
2267 return syms.identityObjectType;
2268 }
2269 if (implicitIdentityType(t)) {
2270 return syms.identityObjectType;
2271 } // else fall through and look for explicit coded super interface
2272 } else if (sym == syms.primitiveObjectType.tsym) {
2273 if (t.isReferenceProjection())
2274 return syms.primitiveObjectType;
2275 if (t.hasTag(ARRAY) || t.tsym == syms.objectType.tsym)
2276 return null;
2277 // else fall through and look for explicit coded super interface
2278 }
2279 return asSuper.visit(t, sym);
2280 }
2281 // where
2282 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() {
2283
2284 private Set<Symbol> seenTypes = new HashSet<>();
2285
2286 public Type visitType(Type t, Symbol sym) {
2287 return null;
2288 }
2289
2290 @Override
2291 public Type visitClassType(ClassType t, Symbol sym) {
2292 if (t.tsym == sym)
2293 return t;
2294
2295 Symbol c = t.tsym;
2296 if (!seenTypes.add(c)) {
2297 return null;
2298 }
2299 try {
2300 Type st = supertype(t);
2301 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR)) {
2302 Type x = asSuper(st, sym);
2303 if (x != null)
2304 return x;
2305 }
2306 if ((sym.flags() & INTERFACE) != 0) {
2307 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
2308 if (!l.head.hasTag(ERROR)) {
2309 Type x = asSuper(l.head, sym);
2310 if (x != null)
2311 return x;
2312 }
2313 }
2314 }
2315 return null;
2316 } finally {
2317 seenTypes.remove(c);
2318 }
2319 }
2320
2321 @Override
2322 public Type visitArrayType(ArrayType t, Symbol sym) {
2323 return isSubtype(t, sym.type) ? sym.type : null;
2324 }
2325
2326 @Override
2327 public Type visitTypeVar(TypeVar t, Symbol sym) {
2328 if (t.tsym == sym)
2329 return t;
2330 else
2331 return asSuper(t.getUpperBound(), sym);
2332 }
2333
2334 @Override
2335 public Type visitErrorType(ErrorType t, Symbol sym) {
2336 return t;
2337 }
2338 };
2339
2340 // where
2341 private boolean implicitIdentityType(Type t) {
2342 /* An abstract class can be declared to implement either IdentityObject or PrimitiveObject;
2343 * or, if it declares a field, an instance initializer, a non-empty constructor, or
2344 * a synchronized method, it implicitly implements IdentityObject.
2345 */
2346 if (!t.tsym.isAbstract())
2347 return false;
2348
2349 for (; t != Type.noType; t = supertype(t)) {
2350
2351 if (t == null || t.tsym == null || t.tsym.kind == ERR)
2352 return false;
2353
2354 if (t.tsym == syms.objectType.tsym)
2355 return false;
2356
2357 if (!t.tsym.isAbstract()) {
2358 return !t.tsym.isPrimitiveClass();
2359 }
2360
2361 if ((t.tsym.flags() & HASINITBLOCK) != 0) {
2362 return true;
2363 }
2364
2365 // No instance fields and no arged constructors both mean inner classes cannot be primitive class supers.
2366 Type encl = t.getEnclosingType();
2367 if (encl != null && encl.hasTag(CLASS)) {
2368 return true;
2369 }
2370 for (Symbol s : t.tsym.members().getSymbols(NON_RECURSIVE)) {
2371 switch (s.kind) {
2372 case VAR:
2373 if ((s.flags() & STATIC) == 0) {
2374 return true;
2375 }
2376 break;
2377 case MTH:
2378 if ((s.flags() & SYNCHRONIZED) != 0) {
2379 return true;
2380 } else if (s.isConstructor()) {
2381 MethodSymbol m = (MethodSymbol)s;
2382 if (m.getParameters().size() > 0) {
2383 return true;
2384 } else {
2385 if ((m.flags() & (GENERATEDCONSTR | EMPTYNOARGCONSTR)) == 0) {
2386 return true;
2387 }
2388 }
2389 }
2390 break;
2391 }
2392 }
2393 }
2394 return false;
2395 }
2396
2397 /**
2398 * Return the base type of t or any of its outer types that starts
2399 * with the given symbol. If none exists, return null.
2400 *
2401 * @param t a type
2402 * @param sym a symbol
2403 */
2404 public Type asOuterSuper(Type t, Symbol sym) {
2405 switch (t.getTag()) {
2406 case CLASS:
2407 do {
2408 Type s = asSuper(t, sym);
2409 if (s != null) return s;
2410 t = t.getEnclosingType();
2411 } while (t.hasTag(CLASS));
2412 return null;
2413 case ARRAY:
2414 return isSubtype(t, sym.type) ? sym.type : null;
2415 case TYPEVAR:
2416 return asSuper(t, sym);
2417 case ERROR:
2418 return t;
2419 default:
2420 return null;
2421 }
2422 }
2423
2424 /**
2425 * Return the base type of t or any of its enclosing types that
2426 * starts with the given symbol. If none exists, return null.
2427 *
2428 * @param t a type
2429 * @param sym a symbol
2430 */
2431 public Type asEnclosingSuper(Type t, Symbol sym) {
2432 switch (t.getTag()) {
2433 case CLASS:
2434 do {
2435 Type s = asSuper(t, sym);
2436 if (s != null) return s;
2437 Type outer = t.getEnclosingType();
2438 t = (outer.hasTag(CLASS)) ? outer :
2439 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type :
2440 Type.noType;
2441 } while (t.hasTag(CLASS));
2442 return null;
2443 case ARRAY:
2444 return isSubtype(t, sym.type) ? sym.type : null;
2445 case TYPEVAR:
2446 return asSuper(t, sym);
2447 case ERROR:
2448 return t;
2449 default:
2450 return null;
2451 }
2452 }
2453 // </editor-fold>
2454
2455 // <editor-fold defaultstate="collapsed" desc="memberType">
2456 /**
2457 * The type of given symbol, seen as a member of t.
2458 *
2459 * @param t a type
2460 * @param sym a symbol
2461 */
2462 public Type memberType(Type t, Symbol sym) {
2463
2464 if ((sym.flags() & STATIC) != 0)
2465 return sym.type;
2466
2467 /* If any primitive class types are involved, switch over to the reference universe,
2468 where the hierarchy is navigable. V and V.ref have identical membership
2469 with no bridging needs.
2470 */
2471 if (t.isPrimitiveClass())
2472 t = t.referenceProjection();
2473
2474 return memberType.visit(t, sym);
2475 }
2476 // where
2477 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() {
2478
2479 public Type visitType(Type t, Symbol sym) {
2480 return sym.type;
2481 }
2482
2483 @Override
2484 public Type visitWildcardType(WildcardType t, Symbol sym) {
2485 return memberType(wildUpperBound(t), sym);
2486 }
2487
2488 @Override
2489 public Type visitClassType(ClassType t, Symbol sym) {
2490 Symbol owner = sym.owner;
2491 long flags = sym.flags();
2492 if (((flags & STATIC) == 0) && owner.type.isParameterized()) {
2493 Type base = asOuterSuper(t, owner);
2494 //if t is an intersection type T = CT & I1 & I2 ... & In
2495 //its supertypes CT, I1, ... In might contain wildcards
2496 //so we need to go through capture conversion
2497 base = t.isCompound() ? capture(base) : base;
2498 if (base != null) {
2499 List<Type> ownerParams = owner.type.allparams();
2500 List<Type> baseParams = base.allparams();
2501 if (ownerParams.nonEmpty()) {
2502 if (baseParams.isEmpty()) {
2503 // then base is a raw type
2504 return erasure(sym.type);
2505 } else {
2506 return subst(sym.type, ownerParams, baseParams);
2507 }
2508 }
2509 }
2510 }
2511 return sym.type;
2512 }
2513
2514 @Override
2515 public Type visitTypeVar(TypeVar t, Symbol sym) {
2516 return memberType(t.getUpperBound(), sym);
2517 }
2518
2519 @Override
2520 public Type visitErrorType(ErrorType t, Symbol sym) {
2521 return t;
2522 }
2523 };
2524 // </editor-fold>
2525
2526 // <editor-fold defaultstate="collapsed" desc="isAssignable">
2527 public boolean isAssignable(Type t, Type s) {
2528 return isAssignable(t, s, noWarnings);
2529 }
2530
2531 /**
2532 * Is t assignable to s?<br>
2533 * Equivalent to subtype except for constant values and raw
2534 * types.<br>
2535 * (not defined for Method and ForAll types)
2536 */
2537 public boolean isAssignable(Type t, Type s, Warner warn) {
2538 if (t.hasTag(ERROR))
2539 return true;
2540 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) {
2541 int value = ((Number)t.constValue()).intValue();
2542 switch (s.getTag()) {
2543 case BYTE:
2544 case CHAR:
2545 case SHORT:
2546 case INT:
2547 if (s.getTag().checkRange(value))
2548 return true;
2549 break;
2550 case CLASS:
2551 switch (unboxedType(s).getTag()) {
2552 case BYTE:
2553 case CHAR:
2554 case SHORT:
2555 return isAssignable(t, unboxedType(s), warn);
2556 }
2557 break;
2558 }
2559 }
2560 return isConvertible(t, s, warn);
2561 }
2562 // </editor-fold>
2563
2564 // <editor-fold defaultstate="collapsed" desc="erasure">
2565 /**
2566 * The erasure of t {@code |t|} -- the type that results when all
2567 * type parameters in t are deleted.
2568 */
2569 public Type erasure(Type t) {
2570 return eraseNotNeeded(t) ? t : erasure(t, false);
2571 }
2572 //where
2573 private boolean eraseNotNeeded(Type t) {
2574 // We don't want to erase primitive types and String type as that
2575 // operation is idempotent. Also, erasing these could result in loss
2576 // of information such as constant values attached to such types.
2577 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym);
2578 }
2579
2580 private Type erasure(Type t, boolean recurse) {
2581 if (t.isPrimitive()) {
2582 return t; /* fast special case */
2583 } else {
2584 Type out = erasure.visit(t, recurse);
2585 return out;
2586 }
2587 }
2588 // where
2589 private TypeMapping<Boolean> erasure = new StructuralTypeMapping<Boolean>() {
2590 private Type combineMetadata(final Type s,
2591 final Type t) {
2592 if (t.getMetadata() != TypeMetadata.EMPTY) {
2593 switch (s.getKind()) {
2594 case OTHER:
2595 case UNION:
2596 case INTERSECTION:
2597 case PACKAGE:
2598 case EXECUTABLE:
2599 case NONE:
2600 case VOID:
2601 case ERROR:
2602 return s;
2603 default: return s.cloneWithMetadata(s.getMetadata().without(Kind.ANNOTATIONS));
2604 }
2605 } else {
2606 return s;
2607 }
2608 }
2609
2610 public Type visitType(Type t, Boolean recurse) {
2611 if (t.isPrimitive())
2612 return t; /*fast special case*/
2613 else {
2614 //other cases already handled
2615 return combineMetadata(t, t);
2616 }
2617 }
2618
2619 @Override
2620 public Type visitWildcardType(WildcardType t, Boolean recurse) {
2621 Type erased = erasure(wildUpperBound(t), recurse);
2622 return combineMetadata(erased, t);
2623 }
2624
2625 @Override
2626 public Type visitClassType(ClassType t, Boolean recurse) {
2627 // erasure(projection(primitive)) = projection(erasure(primitive))
2628 Type erased = eraseClassType(t, recurse);
2629 Flavor wantedFlavor = t.flavor;
2630 if (t.isIntersection()) {
2631 IntersectionClassType ict = (IntersectionClassType) t;
2632 Type firstExplicitBound = ict.getExplicitComponents().head;
2633 if (firstExplicitBound.hasTag(CLASS))
2634 wantedFlavor = firstExplicitBound.getFlavor();
2635 // Todo: Handle Type variable case.
2636 }
2637 if (erased.hasTag(CLASS) && wantedFlavor != erased.getFlavor()) {
2638 erased = new ClassType(erased.getEnclosingType(),
2639 List.nil(), erased.tsym,
2640 erased.getMetadata(), wantedFlavor);
2641 }
2642 return erased;
2643 }
2644 // where
2645 private Type eraseClassType(ClassType t, Boolean recurse) {
2646 Type erased = t.tsym.erasure(Types.this);
2647 if (recurse) {
2648 erased = new ErasedClassType(erased.getEnclosingType(), erased.tsym,
2649 t.getMetadata().without(Kind.ANNOTATIONS));
2650 return erased;
2651 } else {
2652 return combineMetadata(erased, t);
2653 }
2654 }
2655
2656 @Override
2657 public Type visitTypeVar(TypeVar t, Boolean recurse) {
2658 Type erased = erasure(t.getUpperBound(), recurse);
2659 return combineMetadata(erased, t);
2660 }
2661 };
2662
2663 public List<Type> erasure(List<Type> ts) {
2664 return erasure.visit(ts, false);
2665 }
2666
2667 public Type erasureRecursive(Type t) {
2668 return erasure(t, true);
2669 }
2670
2671 public List<Type> erasureRecursive(List<Type> ts) {
2672 return erasure.visit(ts, true);
2673 }
2674 // </editor-fold>
2675
2676 // <editor-fold defaultstate="collapsed" desc="makeIntersectionType">
2677 /**
2678 * Make an intersection type from non-empty list of types. The list should be ordered according to
2679 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. Note that this might cause a symbol completion.
2680 * Hence, this version of makeIntersectionType may not be called during a classfile read.
2681 *
2682 * @param bounds the types from which the intersection type is formed
2683 */
2684 public IntersectionClassType makeIntersectionType(List<Type> bounds) {
2685 return makeIntersectionType(bounds, bounds.head.tsym.isInterface());
2686 }
2687
2688 /**
2689 * Make an intersection type from non-empty list of types. The list should be ordered according to
2690 * {@link TypeSymbol#precedes(TypeSymbol, Types)}. This does not cause symbol completion as
2691 * an extra parameter indicates as to whether all bounds are interfaces - in which case the
2692 * supertype is implicitly assumed to be 'Object'.
2693 *
2694 * @param bounds the types from which the intersection type is formed
2695 * @param allInterfaces are all bounds interface types?
2696 */
2697 public IntersectionClassType makeIntersectionType(List<Type> bounds, boolean allInterfaces) {
2698 Assert.check(bounds.nonEmpty());
2699 Type firstExplicitBound = bounds.head;
2700 if (allInterfaces) {
2701 bounds = bounds.prepend(syms.objectType);
2702 }
2703 long flags = ABSTRACT | PUBLIC | SYNTHETIC | COMPOUND | ACYCLIC;
2704 ClassSymbol bc =
2705 new ClassSymbol(flags,
2706 Type.moreInfo
2707 ? names.fromString(bounds.toString())
2708 : names.empty,
2709 null,
2710 syms.noSymbol);
2711 IntersectionClassType intersectionType = new IntersectionClassType(bounds, bc, allInterfaces);
2712 bc.type = intersectionType;
2713 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ?
2714 syms.objectType : // error condition, recover
2715 erasure(firstExplicitBound);
2716 bc.members_field = WriteableScope.create(bc);
2717 return intersectionType;
2718 }
2719 // </editor-fold>
2720
2721 // <editor-fold defaultstate="collapsed" desc="supertype">
2722 public Type supertype(Type t) {
2723 return supertype.visit(t);
2724 }
2725 // where
2726 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() {
2727
2728 public Type visitType(Type t, Void ignored) {
2729 // A note on wildcards: there is no good way to
2730 // determine a supertype for a super bounded wildcard.
2731 return Type.noType;
2732 }
2733
2734 @Override
2735 public Type visitClassType(ClassType t, Void ignored) {
2736 if (t.supertype_field == null) {
2737 Type supertype = ((ClassSymbol)t.tsym).getSuperclass();
2738 // An interface has no superclass; its supertype is Object.
2739 if (t.isInterface())
2740 supertype = ((ClassType)t.tsym.type).supertype_field;
2741 if (t.supertype_field == null) {
2742 List<Type> actuals = classBound(t).allparams();
2743 List<Type> formals = t.tsym.type.allparams();
2744 if (t.hasErasedSupertypes()) {
2745 t.supertype_field = erasureRecursive(supertype);
2746 } else if (formals.nonEmpty()) {
2747 t.supertype_field = subst(supertype, formals, actuals);
2748 }
2749 else {
2750 t.supertype_field = supertype;
2751 }
2752 }
2753 }
2754 return t.supertype_field;
2755 }
2756
2757 /**
2758 * The supertype is always a class type. If the type
2759 * variable's bounds start with a class type, this is also
2760 * the supertype. Otherwise, the supertype is
2761 * java.lang.Object.
2762 */
2763 @Override
2764 public Type visitTypeVar(TypeVar t, Void ignored) {
2765 if (t.getUpperBound().hasTag(TYPEVAR) ||
2766 (!t.getUpperBound().isCompound() && !t.getUpperBound().isInterface())) {
2767 return t.getUpperBound();
2768 } else {
2769 return supertype(t.getUpperBound());
2770 }
2771 }
2772
2773 @Override
2774 public Type visitArrayType(ArrayType t, Void ignored) {
2775 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType))
2776 return arraySuperType();
2777 else
2778 return new ArrayType(supertype(t.elemtype), t.tsym);
2779 }
2780
2781 @Override
2782 public Type visitErrorType(ErrorType t, Void ignored) {
2783 return Type.noType;
2784 }
2785 };
2786 // </editor-fold>
2787
2788 // <editor-fold defaultstate="collapsed" desc="interfaces">
2789 /**
2790 * Return the interfaces implemented by this class.
2791 */
2792 public List<Type> interfaces(Type t) {
2793 return interfaces.visit(t);
2794 }
2795 // where
2796 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() {
2797
2798 public List<Type> visitType(Type t, Void ignored) {
2799 return List.nil();
2800 }
2801
2802 @Override
2803 public List<Type> visitClassType(ClassType t, Void ignored) {
2804 if (t.interfaces_field == null) {
2805 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces();
2806 if (t.interfaces_field == null) {
2807 // If t.interfaces_field is null, then t must
2808 // be a parameterized type (not to be confused
2809 // with a generic type declaration).
2810 // Terminology:
2811 // Parameterized type: List<String>
2812 // Generic type declaration: class List<E> { ... }
2813 // So t corresponds to List<String> and
2814 // t.tsym.type corresponds to List<E>.
2815 // The reason t must be parameterized type is
2816 // that completion will happen as a side
2817 // effect of calling
2818 // ClassSymbol.getInterfaces. Since
2819 // t.interfaces_field is null after
2820 // completion, we can assume that t is not the
2821 // type of a class/interface declaration.
2822 Assert.check(t != t.tsym.type, t);
2823 List<Type> actuals = t.allparams();
2824 List<Type> formals = t.tsym.type.allparams();
2825 if (t.hasErasedSupertypes()) {
2826 t.interfaces_field = erasureRecursive(interfaces);
2827 } else if (formals.nonEmpty()) {
2828 t.interfaces_field = subst(interfaces, formals, actuals);
2829 }
2830 else {
2831 t.interfaces_field = interfaces;
2832 }
2833 }
2834 }
2835 return t.interfaces_field;
2836 }
2837
2838 @Override
2839 public List<Type> visitTypeVar(TypeVar t, Void ignored) {
2840 if (t.getUpperBound().isCompound())
2841 return interfaces(t.getUpperBound());
2842
2843 if (t.getUpperBound().isInterface())
2844 return List.of(t.getUpperBound());
2845
2846 return List.nil();
2847 }
2848 };
2849
2850 public List<Type> directSupertypes(Type t) {
2851 return directSupertypes.visit(t);
2852 }
2853 // where
2854 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() {
2855
2856 public List<Type> visitType(final Type type, final Void ignored) {
2857 if (!type.isIntersection()) {
2858 final Type sup = supertype(type);
2859 return (sup == Type.noType || sup == type || sup == null)
2860 ? interfaces(type)
2861 : interfaces(type).prepend(sup);
2862 } else {
2863 return ((IntersectionClassType)type).getExplicitComponents();
2864 }
2865 }
2866 };
2867
2868 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) {
2869 for (Type i2 : interfaces(origin.type)) {
2870 if (isym == i2.tsym) return true;
2871 }
2872 return false;
2873 }
2874 // </editor-fold>
2875
2876 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw">
2877 Map<Type,Boolean> isDerivedRawCache = new HashMap<>();
2878
2879 public boolean isDerivedRaw(Type t) {
2880 Boolean result = isDerivedRawCache.get(t);
2881 if (result == null) {
2882 result = isDerivedRawInternal(t);
2883 isDerivedRawCache.put(t, result);
2884 }
2885 return result;
2886 }
2887
2888 public boolean isDerivedRawInternal(Type t) {
2889 if (t.isErroneous())
2890 return false;
2891 return
2892 t.isRaw() ||
2893 supertype(t) != Type.noType && isDerivedRaw(supertype(t)) ||
2894 isDerivedRaw(interfaces(t));
2895 }
2896
2897 public boolean isDerivedRaw(List<Type> ts) {
2898 List<Type> l = ts;
2899 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail;
2900 return l.nonEmpty();
2901 }
2902 // </editor-fold>
2903
2904 // <editor-fold defaultstate="collapsed" desc="setBounds">
2905 /**
2906 * Same as {@link Types#setBounds(TypeVar, List, boolean)}, except that third parameter is computed directly,
2907 * as follows: if all all bounds are interface types, the computed supertype is Object,otherwise
2908 * the supertype is simply left null (in this case, the supertype is assumed to be the head of
2909 * the bound list passed as second argument). Note that this check might cause a symbol completion.
2910 * Hence, this version of setBounds may not be called during a classfile read.
2911 *
2912 * @param t a type variable
2913 * @param bounds the bounds, must be nonempty
2914 */
2915 public void setBounds(TypeVar t, List<Type> bounds) {
2916 setBounds(t, bounds, bounds.head.tsym.isInterface());
2917 }
2918
2919 /**
2920 * Set the bounds field of the given type variable to reflect a (possibly multiple) list of bounds.
2921 * This does not cause symbol completion as an extra parameter indicates as to whether all bounds
2922 * are interfaces - in which case the supertype is implicitly assumed to be 'Object'.
2923 *
2924 * @param t a type variable
2925 * @param bounds the bounds, must be nonempty
2926 * @param allInterfaces are all bounds interface types?
2927 */
2928 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) {
2929 t.setUpperBound( bounds.tail.isEmpty() ?
2930 bounds.head :
2931 makeIntersectionType(bounds, allInterfaces) );
2932 t.rank_field = -1;
2933 }
2934 // </editor-fold>
2935
2936 // <editor-fold defaultstate="collapsed" desc="getBounds">
2937 /**
2938 * Return list of bounds of the given type variable.
2939 */
2940 public List<Type> getBounds(TypeVar t) {
2941 if (t.getUpperBound().hasTag(NONE))
2942 return List.nil();
2943 else if (t.getUpperBound().isErroneous() || !t.getUpperBound().isCompound())
2944 return List.of(t.getUpperBound());
2945 else if ((erasure(t).tsym.flags() & INTERFACE) == 0)
2946 return interfaces(t).prepend(supertype(t));
2947 else
2948 // No superclass was given in bounds.
2949 // In this case, supertype is Object, erasure is first interface.
2950 return interfaces(t);
2951 }
2952 // </editor-fold>
2953
2954 // <editor-fold defaultstate="collapsed" desc="classBound">
2955 /**
2956 * If the given type is a (possibly selected) type variable,
2957 * return the bounding class of this type, otherwise return the
2958 * type itself.
2959 */
2960 public Type classBound(Type t) {
2961 return classBound.visit(t);
2962 }
2963 // where
2964 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() {
2965
2966 public Type visitType(Type t, Void ignored) {
2967 return t;
2968 }
2969
2970 @Override
2971 public Type visitClassType(ClassType t, Void ignored) {
2972 Type outer1 = classBound(t.getEnclosingType());
2973 if (outer1 != t.getEnclosingType())
2974 return new ClassType(outer1, t.getTypeArguments(), t.tsym,
2975 t.getMetadata(), t.getFlavor());
2976 else
2977 return t;
2978 }
2979
2980 @Override
2981 public Type visitTypeVar(TypeVar t, Void ignored) {
2982 return classBound(supertype(t));
2983 }
2984
2985 @Override
2986 public Type visitErrorType(ErrorType t, Void ignored) {
2987 return t;
2988 }
2989 };
2990 // </editor-fold>
2991
2992 // <editor-fold defaultstate="collapsed" desc="sub signature / override equivalence">
2993 /**
2994 * Returns true iff the first signature is a <em>sub
2995 * signature</em> of the other. This is <b>not</b> an equivalence
2996 * relation.
2997 *
2998 * @jls 8.4.2 Method Signature
2999 * @see #overrideEquivalent(Type t, Type s)
3000 * @param t first signature (possibly raw).
3001 * @param s second signature (could be subjected to erasure).
3002 * @return true if t is a sub signature of s.
3003 */
3004 public boolean isSubSignature(Type t, Type s) {
3005 return isSubSignature(t, s, true);
3006 }
3007
3008 public boolean isSubSignature(Type t, Type s, boolean strict) {
3009 return hasSameArgs(t, s, strict) || hasSameArgs(t, erasure(s), strict);
3010 }
3011
3012 /**
3013 * Returns true iff these signatures are related by <em>override
3014 * equivalence</em>. This is the natural extension of
3015 * isSubSignature to an equivalence relation.
3016 *
3017 * @jls 8.4.2 Method Signature
3018 * @see #isSubSignature(Type t, Type s)
3019 * @param t a signature (possible raw, could be subjected to
3020 * erasure).
3021 * @param s a signature (possible raw, could be subjected to
3022 * erasure).
3023 * @return true if either argument is a sub signature of the other.
3024 */
3025 public boolean overrideEquivalent(Type t, Type s) {
3026 return hasSameArgs(t, s) ||
3027 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s);
3028 }
3029
3030 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) {
3031 for (Symbol sym : syms.objectType.tsym.members().getSymbolsByName(msym.name)) {
3032 if (msym.overrides(sym, origin, Types.this, true)) {
3033 return true;
3034 }
3035 }
3036 return false;
3037 }
3038
3039 /**
3040 * This enum defines the strategy for implementing most specific return type check
3041 * during the most specific and functional interface checks.
3042 */
3043 public enum MostSpecificReturnCheck {
3044 /**
3045 * Return r1 is more specific than r2 if {@code r1 <: r2}. Extra care required for (i) handling
3046 * method type variables (if either method is generic) and (ii) subtyping should be replaced
3047 * by type-equivalence for primitives. This is essentially an inlined version of
3048 * {@link Types#resultSubtype(Type, Type, Warner)}, where the assignability check has been
3049 * replaced with a strict subtyping check.
3050 */
3051 BASIC() {
3052 @Override
3053 public boolean test(Type mt1, Type mt2, Types types) {
3054 List<Type> tvars = mt1.getTypeArguments();
3055 List<Type> svars = mt2.getTypeArguments();
3056 Type t = mt1.getReturnType();
3057 Type s = types.subst(mt2.getReturnType(), svars, tvars);
3058 return types.isSameType(t, s) ||
3059 !t.isPrimitive() &&
3060 !s.isPrimitive() &&
3061 types.isSubtype(t, s);
3062 }
3063 },
3064 /**
3065 * Return r1 is more specific than r2 if r1 is return-type-substitutable for r2.
3066 */
3067 RTS() {
3068 @Override
3069 public boolean test(Type mt1, Type mt2, Types types) {
3070 return types.returnTypeSubstitutable(mt1, mt2);
3071 }
3072 };
3073
3074 public abstract boolean test(Type mt1, Type mt2, Types types);
3075 }
3076
3077 /**
3078 * Merge multiple abstract methods. The preferred method is a method that is a subsignature
3079 * of all the other signatures and whose return type is more specific {@see MostSpecificReturnCheck}.
3080 * The resulting preferred method has a thrown clause that is the intersection of the merged
3081 * methods' clauses.
3082 */
3083 public Optional<Symbol> mergeAbstracts(List<Symbol> ambiguousInOrder, Type site, boolean sigCheck) {
3084 //first check for preconditions
3085 boolean shouldErase = false;
3086 List<Type> erasedParams = ambiguousInOrder.head.erasure(this).getParameterTypes();
3087 for (Symbol s : ambiguousInOrder) {
3088 if ((s.flags() & ABSTRACT) == 0 ||
3089 (sigCheck && !isSameTypes(erasedParams, s.erasure(this).getParameterTypes()))) {
3090 return Optional.empty();
3091 } else if (s.type.hasTag(FORALL)) {
3092 shouldErase = true;
3093 }
3094 }
3095 //then merge abstracts
3096 for (MostSpecificReturnCheck mostSpecificReturnCheck : MostSpecificReturnCheck.values()) {
3097 outer: for (Symbol s : ambiguousInOrder) {
3098 Type mt = memberType(site, s);
3099 List<Type> allThrown = mt.getThrownTypes();
3100 for (Symbol s2 : ambiguousInOrder) {
3101 if (s != s2) {
3102 Type mt2 = memberType(site, s2);
3103 if (!isSubSignature(mt, mt2) ||
3104 !mostSpecificReturnCheck.test(mt, mt2, this)) {
3105 //ambiguity cannot be resolved
3106 continue outer;
3107 } else {
3108 List<Type> thrownTypes2 = mt2.getThrownTypes();
3109 if (!mt.hasTag(FORALL) && shouldErase) {
3110 thrownTypes2 = erasure(thrownTypes2);
3111 } else if (mt.hasTag(FORALL)) {
3112 //subsignature implies that if most specific is generic, then all other
3113 //methods are too
3114 Assert.check(mt2.hasTag(FORALL));
3115 // if both are generic methods, adjust thrown types ahead of intersection computation
3116 thrownTypes2 = subst(thrownTypes2, mt2.getTypeArguments(), mt.getTypeArguments());
3117 }
3118 allThrown = chk.intersect(allThrown, thrownTypes2);
3119 }
3120 }
3121 }
3122 return (allThrown == mt.getThrownTypes()) ?
3123 Optional.of(s) :
3124 Optional.of(new MethodSymbol(
3125 s.flags(),
3126 s.name,
3127 createMethodTypeWithThrown(s.type, allThrown),
3128 s.owner) {
3129 @Override
3130 public Symbol baseSymbol() {
3131 return s;
3132 }
3133 });
3134 }
3135 }
3136 return Optional.empty();
3137 }
3138
3139 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site">
3140 class ImplementationCache {
3141
3142 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map = new WeakHashMap<>();
3143
3144 class Entry {
3145 final MethodSymbol cachedImpl;
3146 final Predicate<Symbol> implFilter;
3147 final boolean checkResult;
3148 final int prevMark;
3149
3150 public Entry(MethodSymbol cachedImpl,
3151 Predicate<Symbol> scopeFilter,
3152 boolean checkResult,
3153 int prevMark) {
3154 this.cachedImpl = cachedImpl;
3155 this.implFilter = scopeFilter;
3156 this.checkResult = checkResult;
3157 this.prevMark = prevMark;
3158 }
3159
3160 boolean matches(Predicate<Symbol> scopeFilter, boolean checkResult, int mark) {
3161 return this.implFilter == scopeFilter &&
3162 this.checkResult == checkResult &&
3163 this.prevMark == mark;
3164 }
3165 }
3166
3167 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3168 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms);
3169 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null;
3170 if (cache == null) {
3171 cache = new HashMap<>();
3172 _map.put(ms, new SoftReference<>(cache));
3173 }
3174 Entry e = cache.get(origin);
3175 CompoundScope members = membersClosure(origin.type, true);
3176 if (e == null ||
3177 !e.matches(implFilter, checkResult, members.getMark())) {
3178 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter);
3179 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark()));
3180 return impl;
3181 }
3182 else {
3183 return e.cachedImpl;
3184 }
3185 }
3186
3187 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3188 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) {
3189 t = skipTypeVars(t, false);
3190 TypeSymbol c = t.tsym;
3191 Symbol bestSoFar = null;
3192 for (Symbol sym : c.members().getSymbolsByName(ms.name, implFilter)) {
3193 if (sym != null && sym.overrides(ms, origin, Types.this, checkResult)) {
3194 bestSoFar = sym;
3195 if ((sym.flags() & ABSTRACT) == 0) {
3196 //if concrete impl is found, exit immediately
3197 break;
3198 }
3199 }
3200 }
3201 if (bestSoFar != null) {
3202 //return either the (only) concrete implementation or the first abstract one
3203 return (MethodSymbol)bestSoFar;
3204 }
3205 }
3206 return null;
3207 }
3208 }
3209
3210 private ImplementationCache implCache = new ImplementationCache();
3211
3212 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Predicate<Symbol> implFilter) {
3213 return implCache.get(ms, origin, checkResult, implFilter);
3214 }
3215 // </editor-fold>
3216
3217 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site">
3218 class MembersClosureCache extends SimpleVisitor<Scope.CompoundScope, Void> {
3219
3220 private Map<TypeSymbol, CompoundScope> _map = new HashMap<>();
3221
3222 Set<TypeSymbol> seenTypes = new HashSet<>();
3223
3224 class MembersScope extends CompoundScope {
3225
3226 CompoundScope scope;
3227
3228 public MembersScope(CompoundScope scope) {
3229 super(scope.owner);
3230 this.scope = scope;
3231 }
3232
3233 Predicate<Symbol> combine(Predicate<Symbol> sf) {
3234 return s -> !s.owner.isInterface() && (sf == null || sf.test(s));
3235 }
3236
3237 @Override
3238 public Iterable<Symbol> getSymbols(Predicate<Symbol> sf, LookupKind lookupKind) {
3239 return scope.getSymbols(combine(sf), lookupKind);
3240 }
3241
3242 @Override
3243 public Iterable<Symbol> getSymbolsByName(Name name, Predicate<Symbol> sf, LookupKind lookupKind) {
3244 return scope.getSymbolsByName(name, combine(sf), lookupKind);
3245 }
3246
3247 @Override
3248 public int getMark() {
3249 return scope.getMark();
3250 }
3251 }
3252
3253 CompoundScope nilScope;
3254
3255 /** members closure visitor methods **/
3256
3257 public CompoundScope visitType(Type t, Void _unused) {
3258 if (nilScope == null) {
3259 nilScope = new CompoundScope(syms.noSymbol);
3260 }
3261 return nilScope;
3262 }
3263
3264 @Override
3265 public CompoundScope visitClassType(ClassType t, Void _unused) {
3266 if (!seenTypes.add(t.tsym)) {
3267 //this is possible when an interface is implemented in multiple
3268 //superclasses, or when a class hierarchy is circular - in such
3269 //cases we don't need to recurse (empty scope is returned)
3270 return new CompoundScope(t.tsym);
3271 }
3272 try {
3273 seenTypes.add(t.tsym);
3274 ClassSymbol csym = (ClassSymbol)t.tsym;
3275 CompoundScope membersClosure = _map.get(csym);
3276 if (membersClosure == null) {
3277 membersClosure = new CompoundScope(csym);
3278 for (Type i : interfaces(t)) {
3279 membersClosure.prependSubScope(visit(i, null));
3280 }
3281 membersClosure.prependSubScope(visit(supertype(t), null));
3282 membersClosure.prependSubScope(csym.members());
3283 _map.put(csym, membersClosure);
3284 }
3285 return membersClosure;
3286 }
3287 finally {
3288 seenTypes.remove(t.tsym);
3289 }
3290 }
3291
3292 @Override
3293 public CompoundScope visitTypeVar(TypeVar t, Void _unused) {
3294 return visit(t.getUpperBound(), null);
3295 }
3296 }
3297
3298 private MembersClosureCache membersCache = new MembersClosureCache();
3299
3300 public CompoundScope membersClosure(Type site, boolean skipInterface) {
3301 CompoundScope cs = membersCache.visit(site, null);
3302 Assert.checkNonNull(cs, () -> "type " + site);
3303 return skipInterface ? membersCache.new MembersScope(cs) : cs;
3304 }
3305 // </editor-fold>
3306
3307
3308 /** Return first abstract member of class `sym'.
3309 */
3310 public MethodSymbol firstUnimplementedAbstract(ClassSymbol sym) {
3311 try {
3312 return firstUnimplementedAbstractImpl(sym, sym);
3313 } catch (CompletionFailure ex) {
3314 chk.completionError(enter.getEnv(sym).tree.pos(), ex);
3315 return null;
3316 }
3317 }
3318 //where:
3319 private MethodSymbol firstUnimplementedAbstractImpl(ClassSymbol impl, ClassSymbol c) {
3320 MethodSymbol undef = null;
3321 // Do not bother to search in classes that are not abstract,
3322 // since they cannot have abstract members.
3323 if (c == impl || (c.flags() & (ABSTRACT | INTERFACE)) != 0) {
3324 Scope s = c.members();
3325 for (Symbol sym : s.getSymbols(NON_RECURSIVE)) {
3326 if (sym.kind == MTH &&
3327 (sym.flags() & (ABSTRACT|DEFAULT|PRIVATE)) == ABSTRACT) {
3328 MethodSymbol absmeth = (MethodSymbol)sym;
3329 MethodSymbol implmeth = absmeth.implementation(impl, this, true);
3330 if (implmeth == null || implmeth == absmeth) {
3331 //look for default implementations
3332 if (allowDefaultMethods) {
3333 MethodSymbol prov = interfaceCandidates(impl.type, absmeth).head;
3334 if (prov != null && prov.overrides(absmeth, impl, this, true)) {
3335 implmeth = prov;
3336 }
3337 }
3338 }
3339 if (implmeth == null || implmeth == absmeth) {
3340 undef = absmeth;
3341 break;
3342 }
3343 }
3344 }
3345 if (undef == null) {
3346 Type st = supertype(c.type);
3347 if (st.hasTag(CLASS))
3348 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)st.tsym);
3349 }
3350 for (List<Type> l = interfaces(c.type);
3351 undef == null && l.nonEmpty();
3352 l = l.tail) {
3353 undef = firstUnimplementedAbstractImpl(impl, (ClassSymbol)l.head.tsym);
3354 }
3355 }
3356 return undef;
3357 }
3358
3359 public class CandidatesCache {
3360 public Map<Entry, List<MethodSymbol>> cache = new WeakHashMap<>();
3361
3362 class Entry {
3363 Type site;
3364 MethodSymbol msym;
3365
3366 Entry(Type site, MethodSymbol msym) {
3367 this.site = site;
3368 this.msym = msym;
3369 }
3370
3371 @Override
3372 public boolean equals(Object obj) {
3373 return (obj instanceof Entry entry)
3374 && entry.msym == msym
3375 && isSameType(site, entry.site);
3376 }
3377
3378 @Override
3379 public int hashCode() {
3380 return Types.this.hashCode(site) & ~msym.hashCode();
3381 }
3382 }
3383
3384 public List<MethodSymbol> get(Entry e) {
3385 return cache.get(e);
3386 }
3387
3388 public void put(Entry e, List<MethodSymbol> msymbols) {
3389 cache.put(e, msymbols);
3390 }
3391 }
3392
3393 public CandidatesCache candidatesCache = new CandidatesCache();
3394
3395 //where
3396 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) {
3397 CandidatesCache.Entry e = candidatesCache.new Entry(site, ms);
3398 List<MethodSymbol> candidates = candidatesCache.get(e);
3399 if (candidates == null) {
3400 Predicate<Symbol> filter = new MethodFilter(ms, site);
3401 List<MethodSymbol> candidates2 = List.nil();
3402 for (Symbol s : membersClosure(site, false).getSymbols(filter)) {
3403 if (!site.tsym.isInterface() && !s.owner.isInterface()) {
3404 return List.of((MethodSymbol)s);
3405 } else if (!candidates2.contains(s)) {
3406 candidates2 = candidates2.prepend((MethodSymbol)s);
3407 }
3408 }
3409 candidates = prune(candidates2);
3410 candidatesCache.put(e, candidates);
3411 }
3412 return candidates;
3413 }
3414
3415 public List<MethodSymbol> prune(List<MethodSymbol> methods) {
3416 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>();
3417 for (MethodSymbol m1 : methods) {
3418 boolean isMin_m1 = true;
3419 for (MethodSymbol m2 : methods) {
3420 if (m1 == m2) continue;
3421 if (m2.owner != m1.owner &&
3422 asSuper(m2.owner.type, m1.owner) != null) {
3423 isMin_m1 = false;
3424 break;
3425 }
3426 }
3427 if (isMin_m1)
3428 methodsMin.append(m1);
3429 }
3430 return methodsMin.toList();
3431 }
3432 // where
3433 private class MethodFilter implements Predicate<Symbol> {
3434
3435 Symbol msym;
3436 Type site;
3437
3438 MethodFilter(Symbol msym, Type site) {
3439 this.msym = msym;
3440 this.site = site;
3441 }
3442
3443 @Override
3444 public boolean test(Symbol s) {
3445 return s.kind == MTH &&
3446 s.name == msym.name &&
3447 (s.flags() & SYNTHETIC) == 0 &&
3448 s.isInheritedIn(site.tsym, Types.this) &&
3449 overrideEquivalent(memberType(site, s), memberType(site, msym));
3450 }
3451 }
3452 // </editor-fold>
3453
3454 /**
3455 * Does t have the same arguments as s? It is assumed that both
3456 * types are (possibly polymorphic) method types. Monomorphic
3457 * method types "have the same arguments", if their argument lists
3458 * are equal. Polymorphic method types "have the same arguments",
3459 * if they have the same arguments after renaming all type
3460 * variables of one to corresponding type variables in the other,
3461 * where correspondence is by position in the type parameter list.
3462 */
3463 public boolean hasSameArgs(Type t, Type s) {
3464 return hasSameArgs(t, s, true);
3465 }
3466
3467 public boolean hasSameArgs(Type t, Type s, boolean strict) {
3468 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict);
3469 }
3470
3471 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) {
3472 return hasSameArgs.visit(t, s);
3473 }
3474 // where
3475 private class HasSameArgs extends TypeRelation {
3476
3477 boolean strict;
3478
3479 public HasSameArgs(boolean strict) {
3480 this.strict = strict;
3481 }
3482
3483 public Boolean visitType(Type t, Type s) {
3484 throw new AssertionError();
3485 }
3486
3487 @Override
3488 public Boolean visitMethodType(MethodType t, Type s) {
3489 return s.hasTag(METHOD)
3490 && containsTypeEquivalent(t.argtypes, s.getParameterTypes());
3491 }
3492
3493 @Override
3494 public Boolean visitForAll(ForAll t, Type s) {
3495 if (!s.hasTag(FORALL))
3496 return strict ? false : visitMethodType(t.asMethodType(), s);
3497
3498 ForAll forAll = (ForAll)s;
3499 return hasSameBounds(t, forAll)
3500 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
3501 }
3502
3503 @Override
3504 public Boolean visitErrorType(ErrorType t, Type s) {
3505 return false;
3506 }
3507 }
3508
3509 TypeRelation hasSameArgs_strict = new HasSameArgs(true);
3510 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false);
3511
3512 // </editor-fold>
3513
3514 // <editor-fold defaultstate="collapsed" desc="subst">
3515 public List<Type> subst(List<Type> ts,
3516 List<Type> from,
3517 List<Type> to) {
3518 return ts.map(new Subst(from, to));
3519 }
3520
3521 /**
3522 * Substitute all occurrences of a type in `from' with the
3523 * corresponding type in `to' in 't'. Match lists `from' and `to'
3524 * from the right: If lists have different length, discard leading
3525 * elements of the longer list.
3526 */
3527 public Type subst(Type t, List<Type> from, List<Type> to) {
3528 return t.map(new Subst(from, to));
3529 }
3530
3531 private class Subst extends StructuralTypeMapping<Void> {
3532 List<Type> from;
3533 List<Type> to;
3534
3535 public Subst(List<Type> from, List<Type> to) {
3536 int fromLength = from.length();
3537 int toLength = to.length();
3538 while (fromLength > toLength) {
3539 fromLength--;
3540 from = from.tail;
3541 }
3542 while (fromLength < toLength) {
3543 toLength--;
3544 to = to.tail;
3545 }
3546 this.from = from;
3547 this.to = to;
3548 }
3549
3550 @Override
3551 public Type visitTypeVar(TypeVar t, Void ignored) {
3552 for (List<Type> from = this.from, to = this.to;
3553 from.nonEmpty();
3554 from = from.tail, to = to.tail) {
3555 if (t.equalsIgnoreMetadata(from.head)) {
3556 return to.head.withTypeVar(t);
3557 }
3558 }
3559 return t;
3560 }
3561
3562 @Override
3563 public Type visitClassType(ClassType t, Void ignored) {
3564 if (!t.isCompound()) {
3565 return super.visitClassType(t, ignored);
3566 } else {
3567 Type st = visit(supertype(t));
3568 List<Type> is = visit(interfaces(t), ignored);
3569 if (st == supertype(t) && is == interfaces(t))
3570 return t;
3571 else
3572 return makeIntersectionType(is.prepend(st));
3573 }
3574 }
3575
3576 @Override
3577 public Type visitWildcardType(WildcardType t, Void ignored) {
3578 WildcardType t2 = (WildcardType)super.visitWildcardType(t, ignored);
3579 if (t2 != t && t.isExtendsBound() && t2.type.isExtendsBound()) {
3580 t2.type = wildUpperBound(t2.type);
3581 }
3582 return t2;
3583 }
3584
3585 @Override
3586 public Type visitForAll(ForAll t, Void ignored) {
3587 if (Type.containsAny(to, t.tvars)) {
3588 //perform alpha-renaming of free-variables in 't'
3589 //if 'to' types contain variables that are free in 't'
3590 List<Type> freevars = newInstances(t.tvars);
3591 t = new ForAll(freevars,
3592 Types.this.subst(t.qtype, t.tvars, freevars));
3593 }
3594 List<Type> tvars1 = substBounds(t.tvars, from, to);
3595 Type qtype1 = visit(t.qtype);
3596 if (tvars1 == t.tvars && qtype1 == t.qtype) {
3597 return t;
3598 } else if (tvars1 == t.tvars) {
3599 return new ForAll(tvars1, qtype1) {
3600 @Override
3601 public boolean needsStripping() {
3602 return true;
3603 }
3604 };
3605 } else {
3606 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1)) {
3607 @Override
3608 public boolean needsStripping() {
3609 return true;
3610 }
3611 };
3612 }
3613 }
3614 }
3615
3616 public List<Type> substBounds(List<Type> tvars,
3617 List<Type> from,
3618 List<Type> to) {
3619 if (tvars.isEmpty())
3620 return tvars;
3621 ListBuffer<Type> newBoundsBuf = new ListBuffer<>();
3622 boolean changed = false;
3623 // calculate new bounds
3624 for (Type t : tvars) {
3625 TypeVar tv = (TypeVar) t;
3626 Type bound = subst(tv.getUpperBound(), from, to);
3627 if (bound != tv.getUpperBound())
3628 changed = true;
3629 newBoundsBuf.append(bound);
3630 }
3631 if (!changed)
3632 return tvars;
3633 ListBuffer<Type> newTvars = new ListBuffer<>();
3634 // create new type variables without bounds
3635 for (Type t : tvars) {
3636 newTvars.append(new TypeVar(t.tsym, null, syms.botType,
3637 t.getMetadata()));
3638 }
3639 // the new bounds should use the new type variables in place
3640 // of the old
3641 List<Type> newBounds = newBoundsBuf.toList();
3642 from = tvars;
3643 to = newTvars.toList();
3644 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) {
3645 newBounds.head = subst(newBounds.head, from, to);
3646 }
3647 newBounds = newBoundsBuf.toList();
3648 // set the bounds of new type variables to the new bounds
3649 for (Type t : newTvars.toList()) {
3650 TypeVar tv = (TypeVar) t;
3651 tv.setUpperBound( newBounds.head );
3652 newBounds = newBounds.tail;
3653 }
3654 return newTvars.toList();
3655 }
3656
3657 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) {
3658 Type bound1 = subst(t.getUpperBound(), from, to);
3659 if (bound1 == t.getUpperBound())
3660 return t;
3661 else {
3662 // create new type variable without bounds
3663 TypeVar tv = new TypeVar(t.tsym, null, syms.botType,
3664 t.getMetadata());
3665 // the new bound should use the new type variable in place
3666 // of the old
3667 tv.setUpperBound( subst(bound1, List.of(t), List.of(tv)) );
3668 return tv;
3669 }
3670 }
3671 // </editor-fold>
3672
3673 // <editor-fold defaultstate="collapsed" desc="hasSameBounds">
3674 /**
3675 * Does t have the same bounds for quantified variables as s?
3676 */
3677 public boolean hasSameBounds(ForAll t, ForAll s) {
3678 List<Type> l1 = t.tvars;
3679 List<Type> l2 = s.tvars;
3680 while (l1.nonEmpty() && l2.nonEmpty() &&
3681 isSameType(l1.head.getUpperBound(),
3682 subst(l2.head.getUpperBound(),
3683 s.tvars,
3684 t.tvars))) {
3685 l1 = l1.tail;
3686 l2 = l2.tail;
3687 }
3688 return l1.isEmpty() && l2.isEmpty();
3689 }
3690 // </editor-fold>
3691
3692 // <editor-fold defaultstate="collapsed" desc="newInstances">
3693 /** Create new vector of type variables from list of variables
3694 * changing all recursive bounds from old to new list.
3695 */
3696 public List<Type> newInstances(List<Type> tvars) {
3697 List<Type> tvars1 = tvars.map(newInstanceFun);
3698 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) {
3699 TypeVar tv = (TypeVar) l.head;
3700 tv.setUpperBound( subst(tv.getUpperBound(), tvars, tvars1) );
3701 }
3702 return tvars1;
3703 }
3704 private static final TypeMapping<Void> newInstanceFun = new TypeMapping<Void>() {
3705 @Override
3706 public TypeVar visitTypeVar(TypeVar t, Void _unused) {
3707 return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound(), t.getMetadata());
3708 }
3709 };
3710 // </editor-fold>
3711
3712 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) {
3713 return original.accept(methodWithParameters, newParams);
3714 }
3715 // where
3716 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() {
3717 public Type visitType(Type t, List<Type> newParams) {
3718 throw new IllegalArgumentException("Not a method type: " + t);
3719 }
3720 public Type visitMethodType(MethodType t, List<Type> newParams) {
3721 return new MethodType(newParams, t.restype, t.thrown, t.tsym);
3722 }
3723 public Type visitForAll(ForAll t, List<Type> newParams) {
3724 return new ForAll(t.tvars, t.qtype.accept(this, newParams));
3725 }
3726 };
3727
3728 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) {
3729 return original.accept(methodWithThrown, newThrown);
3730 }
3731 // where
3732 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() {
3733 public Type visitType(Type t, List<Type> newThrown) {
3734 throw new IllegalArgumentException("Not a method type: " + t);
3735 }
3736 public Type visitMethodType(MethodType t, List<Type> newThrown) {
3737 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym);
3738 }
3739 public Type visitForAll(ForAll t, List<Type> newThrown) {
3740 return new ForAll(t.tvars, t.qtype.accept(this, newThrown));
3741 }
3742 };
3743
3744 public Type createMethodTypeWithReturn(Type original, Type newReturn) {
3745 return original.accept(methodWithReturn, newReturn);
3746 }
3747 // where
3748 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() {
3749 public Type visitType(Type t, Type newReturn) {
3750 throw new IllegalArgumentException("Not a method type: " + t);
3751 }
3752 public Type visitMethodType(MethodType t, Type newReturn) {
3753 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym) {
3754 @Override
3755 public Type baseType() {
3756 return t;
3757 }
3758 };
3759 }
3760 public Type visitForAll(ForAll t, Type newReturn) {
3761 return new ForAll(t.tvars, t.qtype.accept(this, newReturn)) {
3762 @Override
3763 public Type baseType() {
3764 return t;
3765 }
3766 };
3767 }
3768 };
3769
3770 // <editor-fold defaultstate="collapsed" desc="createErrorType">
3771 public Type createErrorType(Type originalType) {
3772 return new ErrorType(originalType, syms.errSymbol);
3773 }
3774
3775 public Type createErrorType(ClassSymbol c, Type originalType) {
3776 return new ErrorType(c, originalType);
3777 }
3778
3779 public Type createErrorType(Name name, TypeSymbol container, Type originalType) {
3780 return new ErrorType(name, container, originalType);
3781 }
3782 // </editor-fold>
3783
3784 // <editor-fold defaultstate="collapsed" desc="rank">
3785 /**
3786 * The rank of a class is the length of the longest path between
3787 * the class and java.lang.Object in the class inheritance
3788 * graph. Undefined for all but reference types.
3789 */
3790 public int rank(Type t) {
3791 switch(t.getTag()) {
3792 case CLASS: {
3793 ClassType cls = (ClassType)t;
3794 if (cls.rank_field < 0) {
3795 Name fullname = cls.tsym.getQualifiedName();
3796 if (fullname == names.java_lang_Object)
3797 cls.rank_field = 0;
3798 else {
3799 int r = rank(supertype(cls));
3800 for (List<Type> l = interfaces(cls);
3801 l.nonEmpty();
3802 l = l.tail) {
3803 if (rank(l.head) > r)
3804 r = rank(l.head);
3805 }
3806 cls.rank_field = r + 1;
3807 }
3808 }
3809 return cls.rank_field;
3810 }
3811 case TYPEVAR: {
3812 TypeVar tvar = (TypeVar)t;
3813 if (tvar.rank_field < 0) {
3814 int r = rank(supertype(tvar));
3815 for (List<Type> l = interfaces(tvar);
3816 l.nonEmpty();
3817 l = l.tail) {
3818 if (rank(l.head) > r) r = rank(l.head);
3819 }
3820 tvar.rank_field = r + 1;
3821 }
3822 return tvar.rank_field;
3823 }
3824 case ERROR:
3825 case NONE:
3826 return 0;
3827 default:
3828 throw new AssertionError();
3829 }
3830 }
3831 // </editor-fold>
3832
3833 /**
3834 * Helper method for generating a string representation of a given type
3835 * accordingly to a given locale
3836 */
3837 public String toString(Type t, Locale locale) {
3838 return Printer.createStandardPrinter(messages).visit(t, locale);
3839 }
3840
3841 /**
3842 * Helper method for generating a string representation of a given type
3843 * accordingly to a given locale
3844 */
3845 public String toString(Symbol t, Locale locale) {
3846 return Printer.createStandardPrinter(messages).visit(t, locale);
3847 }
3848
3849 // <editor-fold defaultstate="collapsed" desc="toString">
3850 /**
3851 * This toString is slightly more descriptive than the one on Type.
3852 *
3853 * @deprecated Types.toString(Type t, Locale l) provides better support
3854 * for localization
3855 */
3856 @Deprecated
3857 public String toString(Type t) {
3858 if (t.hasTag(FORALL)) {
3859 ForAll forAll = (ForAll)t;
3860 return typaramsString(forAll.tvars) + forAll.qtype;
3861 }
3862 return "" + t;
3863 }
3864 // where
3865 private String typaramsString(List<Type> tvars) {
3866 StringBuilder s = new StringBuilder();
3867 s.append('<');
3868 boolean first = true;
3869 for (Type t : tvars) {
3870 if (!first) s.append(", ");
3871 first = false;
3872 appendTyparamString(((TypeVar)t), s);
3873 }
3874 s.append('>');
3875 return s.toString();
3876 }
3877 private void appendTyparamString(TypeVar t, StringBuilder buf) {
3878 buf.append(t);
3879 if (t.getUpperBound() == null ||
3880 t.getUpperBound().tsym.getQualifiedName() == names.java_lang_Object)
3881 return;
3882 buf.append(" extends "); // Java syntax; no need for i18n
3883 Type bound = t.getUpperBound();
3884 if (!bound.isCompound()) {
3885 buf.append(bound);
3886 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) {
3887 buf.append(supertype(t));
3888 for (Type intf : interfaces(t)) {
3889 buf.append('&');
3890 buf.append(intf);
3891 }
3892 } else {
3893 // No superclass was given in bounds.
3894 // In this case, supertype is Object, erasure is first interface.
3895 boolean first = true;
3896 for (Type intf : interfaces(t)) {
3897 if (!first) buf.append('&');
3898 first = false;
3899 buf.append(intf);
3900 }
3901 }
3902 }
3903 // </editor-fold>
3904
3905 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types">
3906 /**
3907 * A cache for closures.
3908 *
3909 * <p>A closure is a list of all the supertypes and interfaces of
3910 * a class or interface type, ordered by ClassSymbol.precedes
3911 * (that is, subclasses come first, arbitrary but fixed
3912 * otherwise).
3913 */
3914 private Map<Type,List<Type>> closureCache = new HashMap<>();
3915
3916 /**
3917 * Returns the closure of a class or interface type.
3918 */
3919 public List<Type> closure(Type t) {
3920 List<Type> cl = closureCache.get(t);
3921 if (cl == null) {
3922 Type st = supertype(t);
3923 if (!t.isCompound()) {
3924 if (st.hasTag(CLASS)) {
3925 cl = insert(closure(st), t);
3926 } else if (st.hasTag(TYPEVAR)) {
3927 cl = closure(st).prepend(t);
3928 } else {
3929 cl = List.of(t);
3930 }
3931 } else {
3932 cl = closure(supertype(t));
3933 }
3934 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail)
3935 cl = union(cl, closure(l.head));
3936 closureCache.put(t, cl);
3937 }
3938 return cl;
3939 }
3940
3941 /**
3942 * Collect types into a new closure (using a @code{ClosureHolder})
3943 */
3944 public Collector<Type, ClosureHolder, List<Type>> closureCollector(boolean minClosure, BiPredicate<Type, Type> shouldSkip) {
3945 return Collector.of(() -> new ClosureHolder(minClosure, shouldSkip),
3946 ClosureHolder::add,
3947 ClosureHolder::merge,
3948 ClosureHolder::closure);
3949 }
3950 //where
3951 class ClosureHolder {
3952 List<Type> closure;
3953 final boolean minClosure;
3954 final BiPredicate<Type, Type> shouldSkip;
3955
3956 ClosureHolder(boolean minClosure, BiPredicate<Type, Type> shouldSkip) {
3957 this.closure = List.nil();
3958 this.minClosure = minClosure;
3959 this.shouldSkip = shouldSkip;
3960 }
3961
3962 void add(Type type) {
3963 closure = insert(closure, type, shouldSkip);
3964 }
3965
3966 ClosureHolder merge(ClosureHolder other) {
3967 closure = union(closure, other.closure, shouldSkip);
3968 return this;
3969 }
3970
3971 List<Type> closure() {
3972 return minClosure ? closureMin(closure) : closure;
3973 }
3974 }
3975
3976 BiPredicate<Type, Type> basicClosureSkip = (t1, t2) -> t1.tsym == t2.tsym;
3977
3978 /**
3979 * Insert a type in a closure
3980 */
3981 public List<Type> insert(List<Type> cl, Type t, BiPredicate<Type, Type> shouldSkip) {
3982 if (cl.isEmpty()) {
3983 return cl.prepend(t);
3984 } else if (shouldSkip.test(t, cl.head)) {
3985 return cl;
3986 } else if (t.tsym.precedes(cl.head.tsym, this)) {
3987 return cl.prepend(t);
3988 } else {
3989 // t comes after head, or the two are unrelated
3990 return insert(cl.tail, t, shouldSkip).prepend(cl.head);
3991 }
3992 }
3993
3994 public List<Type> insert(List<Type> cl, Type t) {
3995 return insert(cl, t, basicClosureSkip);
3996 }
3997
3998 /**
3999 * Form the union of two closures
4000 */
4001 public List<Type> union(List<Type> cl1, List<Type> cl2, BiPredicate<Type, Type> shouldSkip) {
4002 if (cl1.isEmpty()) {
4003 return cl2;
4004 } else if (cl2.isEmpty()) {
4005 return cl1;
4006 } else if (shouldSkip.test(cl1.head, cl2.head)) {
4007 return union(cl1.tail, cl2.tail, shouldSkip).prepend(cl1.head);
4008 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) {
4009 return union(cl1, cl2.tail, shouldSkip).prepend(cl2.head);
4010 } else {
4011 return union(cl1.tail, cl2, shouldSkip).prepend(cl1.head);
4012 }
4013 }
4014
4015 public List<Type> union(List<Type> cl1, List<Type> cl2) {
4016 return union(cl1, cl2, basicClosureSkip);
4017 }
4018
4019 /**
4020 * Intersect two closures
4021 */
4022 public List<Type> intersect(List<Type> cl1, List<Type> cl2) {
4023 if (cl1 == cl2)
4024 return cl1;
4025 if (cl1.isEmpty() || cl2.isEmpty())
4026 return List.nil();
4027 if (cl1.head.tsym.precedes(cl2.head.tsym, this))
4028 return intersect(cl1.tail, cl2);
4029 if (cl2.head.tsym.precedes(cl1.head.tsym, this))
4030 return intersect(cl1, cl2.tail);
4031 if (isSameType(cl1.head, cl2.head))
4032 return intersect(cl1.tail, cl2.tail).prepend(cl1.head);
4033 if (cl1.head.tsym == cl2.head.tsym &&
4034 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) {
4035 if (cl1.head.isParameterized() && cl2.head.isParameterized()) {
4036 Type merge = merge(cl1.head,cl2.head);
4037 return intersect(cl1.tail, cl2.tail).prepend(merge);
4038 }
4039 if (cl1.head.isRaw() || cl2.head.isRaw())
4040 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head));
4041 }
4042 return intersect(cl1.tail, cl2.tail);
4043 }
4044 // where
4045 class TypePair {
4046 final Type t1;
4047 final Type t2;;
4048
4049 TypePair(Type t1, Type t2) {
4050 this.t1 = t1;
4051 this.t2 = t2;
4052 }
4053 @Override
4054 public int hashCode() {
4055 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2);
4056 }
4057 @Override
4058 public boolean equals(Object obj) {
4059 return (obj instanceof TypePair typePair)
4060 && isSameType(t1, typePair.t1)
4061 && isSameType(t2, typePair.t2);
4062 }
4063 }
4064 Set<TypePair> mergeCache = new HashSet<>();
4065 private Type merge(Type c1, Type c2) {
4066 ClassType class1 = (ClassType) c1;
4067 List<Type> act1 = class1.getTypeArguments();
4068 ClassType class2 = (ClassType) c2;
4069 List<Type> act2 = class2.getTypeArguments();
4070 ListBuffer<Type> merged = new ListBuffer<>();
4071 List<Type> typarams = class1.tsym.type.getTypeArguments();
4072
4073 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) {
4074 if (containsType(act1.head, act2.head)) {
4075 merged.append(act1.head);
4076 } else if (containsType(act2.head, act1.head)) {
4077 merged.append(act2.head);
4078 } else {
4079 TypePair pair = new TypePair(c1, c2);
4080 Type m;
4081 if (mergeCache.add(pair)) {
4082 m = new WildcardType(lub(wildUpperBound(act1.head),
4083 wildUpperBound(act2.head)),
4084 BoundKind.EXTENDS,
4085 syms.boundClass);
4086 mergeCache.remove(pair);
4087 } else {
4088 m = new WildcardType(syms.objectType,
4089 BoundKind.UNBOUND,
4090 syms.boundClass);
4091 }
4092 merged.append(m.withTypeVar(typarams.head));
4093 }
4094 act1 = act1.tail;
4095 act2 = act2.tail;
4096 typarams = typarams.tail;
4097 }
4098 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty());
4099 // There is no spec detailing how type annotations are to
4100 // be inherited. So set it to noAnnotations for now
4101 return new ClassType(class1.getEnclosingType(), merged.toList(),
4102 class1.tsym, TypeMetadata.EMPTY, class1.getFlavor());
4103 }
4104
4105 /**
4106 * Return the minimum type of a closure, a compound type if no
4107 * unique minimum exists.
4108 */
4109 private Type compoundMin(List<Type> cl) {
4110 if (cl.isEmpty()) return syms.objectType;
4111 List<Type> compound = closureMin(cl);
4112 if (compound.isEmpty())
4113 return null;
4114 else if (compound.tail.isEmpty())
4115 return compound.head;
4116 else
4117 return makeIntersectionType(compound);
4118 }
4119
4120 /**
4121 * Return the minimum types of a closure, suitable for computing
4122 * compoundMin or glb.
4123 */
4124 private List<Type> closureMin(List<Type> cl) {
4125 ListBuffer<Type> classes = new ListBuffer<>();
4126 ListBuffer<Type> interfaces = new ListBuffer<>();
4127 Set<Type> toSkip = new HashSet<>();
4128 while (!cl.isEmpty()) {
4129 Type current = cl.head;
4130 boolean keep = !toSkip.contains(current);
4131 if (keep && current.hasTag(TYPEVAR)) {
4132 // skip lower-bounded variables with a subtype in cl.tail
4133 for (Type t : cl.tail) {
4134 if (isSubtypeNoCapture(t, current)) {
4135 keep = false;
4136 break;
4137 }
4138 }
4139 }
4140 if (keep) {
4141 if (current.isInterface())
4142 interfaces.append(current);
4143 else
4144 classes.append(current);
4145 for (Type t : cl.tail) {
4146 // skip supertypes of 'current' in cl.tail
4147 if (isSubtypeNoCapture(current, t))
4148 toSkip.add(t);
4149 }
4150 }
4151 cl = cl.tail;
4152 }
4153 return classes.appendList(interfaces).toList();
4154 }
4155
4156 /**
4157 * Return the least upper bound of list of types. if the lub does
4158 * not exist return null.
4159 */
4160 public Type lub(List<Type> ts) {
4161 return lub(ts.toArray(new Type[ts.length()]));
4162 }
4163
4164 /**
4165 * Return the least upper bound (lub) of set of types. If the lub
4166 * does not exist return the type of null (bottom).
4167 */
4168 public Type lub(Type... ts) {
4169 final int UNKNOWN_BOUND = 0;
4170 final int ARRAY_BOUND = 1;
4171 final int CLASS_BOUND = 2;
4172
4173 int[] kinds = new int[ts.length];
4174 int boundkind = UNKNOWN_BOUND;
4175 for (int i = 0 ; i < ts.length ; i++) {
4176 Type t = ts[i];
4177 switch (t.getTag()) {
4178 case CLASS:
4179 boundkind |= kinds[i] = CLASS_BOUND;
4180 break;
4181 case ARRAY:
4182 boundkind |= kinds[i] = ARRAY_BOUND;
4183 break;
4184 case TYPEVAR:
4185 do {
4186 t = t.getUpperBound();
4187 } while (t.hasTag(TYPEVAR));
4188 if (t.hasTag(ARRAY)) {
4189 boundkind |= kinds[i] = ARRAY_BOUND;
4190 } else {
4191 boundkind |= kinds[i] = CLASS_BOUND;
4192 }
4193 break;
4194 default:
4195 kinds[i] = UNKNOWN_BOUND;
4196 if (t.isPrimitive())
4197 return syms.errType;
4198 }
4199 }
4200 switch (boundkind) {
4201 case 0:
4202 return syms.botType;
4203
4204 case ARRAY_BOUND:
4205 // calculate lub(A[], B[])
4206 Type[] elements = new Type[ts.length];
4207 for (int i = 0 ; i < ts.length ; i++) {
4208 Type elem = elements[i] = elemTypeFun.apply(ts[i]);
4209 if (elem.isPrimitive()) {
4210 // if a primitive type is found, then return
4211 // arraySuperType unless all the types are the
4212 // same
4213 Type first = ts[0];
4214 for (int j = 1 ; j < ts.length ; j++) {
4215 if (!isSameType(first, ts[j])) {
4216 // lub(int[], B[]) is Cloneable & Serializable
4217 return arraySuperType();
4218 }
4219 }
4220 // all the array types are the same, return one
4221 // lub(int[], int[]) is int[]
4222 return first;
4223 }
4224 }
4225 // lub(A[], B[]) is lub(A, B)[]
4226 return new ArrayType(lub(elements), syms.arrayClass);
4227
4228 case CLASS_BOUND:
4229 // calculate lub(A, B)
4230 int startIdx = 0;
4231 for (int i = 0; i < ts.length ; i++) {
4232 Type t = ts[i];
4233 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR)) {
4234 break;
4235 } else {
4236 startIdx++;
4237 }
4238 }
4239 Assert.check(startIdx < ts.length);
4240 //step 1 - compute erased candidate set (EC)
4241 List<Type> cl = erasedSupertypes(ts[startIdx]);
4242 for (int i = startIdx + 1 ; i < ts.length ; i++) {
4243 Type t = ts[i];
4244 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR))
4245 cl = intersect(cl, erasedSupertypes(t));
4246 }
4247 //step 2 - compute minimal erased candidate set (MEC)
4248 List<Type> mec = closureMin(cl);
4249 //step 3 - for each element G in MEC, compute lci(Inv(G))
4250 List<Type> candidates = List.nil();
4251 for (Type erasedSupertype : mec) {
4252 List<Type> lci = List.of(asSuper(ts[startIdx], erasedSupertype.tsym));
4253 for (int i = startIdx + 1 ; i < ts.length ; i++) {
4254 Type superType = asSuper(ts[i], erasedSupertype.tsym);
4255 lci = intersect(lci, superType != null ? List.of(superType) : List.nil());
4256 }
4257 candidates = candidates.appendList(lci);
4258 }
4259 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that
4260 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn))
4261 return compoundMin(candidates);
4262
4263 default:
4264 // calculate lub(A, B[])
4265 List<Type> classes = List.of(arraySuperType());
4266 for (int i = 0 ; i < ts.length ; i++) {
4267 if (kinds[i] != ARRAY_BOUND) // Filter out any arrays
4268 classes = classes.prepend(ts[i]);
4269 }
4270 // lub(A, B[]) is lub(A, arraySuperType)
4271 return lub(classes);
4272 }
4273 }
4274 // where
4275 List<Type> erasedSupertypes(Type t) {
4276 ListBuffer<Type> buf = new ListBuffer<>();
4277 for (Type sup : closure(t)) {
4278 if (sup.hasTag(TYPEVAR)) {
4279 buf.append(sup);
4280 } else {
4281 buf.append(erasure(sup));
4282 }
4283 }
4284 return buf.toList();
4285 }
4286
4287 private Type arraySuperType;
4288 private Type arraySuperType() {
4289 // initialized lazily to avoid problems during compiler startup
4290 if (arraySuperType == null) {
4291 // JLS 10.8: all arrays implement Cloneable and Serializable.
4292 arraySuperType = makeIntersectionType(List.of(syms.serializableType,
4293 syms.cloneableType, syms.identityObjectType), true);
4294 }
4295 return arraySuperType;
4296 }
4297 // </editor-fold>
4298
4299 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound">
4300 public Type glb(List<Type> ts) {
4301 Type t1 = ts.head;
4302 for (Type t2 : ts.tail) {
4303 if (t1.isErroneous())
4304 return t1;
4305 t1 = glb(t1, t2);
4306 }
4307 return t1;
4308 }
4309 //where
4310 public Type glb(Type t, Type s) {
4311 if (s == null)
4312 return t;
4313 else if (t.isPrimitive() || s.isPrimitive())
4314 return syms.errType;
4315 else if (isSubtypeNoCapture(t, s))
4316 return t;
4317 else if (isSubtypeNoCapture(s, t))
4318 return s;
4319
4320 List<Type> closure = union(closure(t), closure(s));
4321 return glbFlattened(closure, t);
4322 }
4323 //where
4324 /**
4325 * Perform glb for a list of non-primitive, non-error, non-compound types;
4326 * redundant elements are removed. Bounds should be ordered according to
4327 * {@link Symbol#precedes(TypeSymbol,Types)}.
4328 *
4329 * @param flatBounds List of type to glb
4330 * @param errT Original type to use if the result is an error type
4331 */
4332 private Type glbFlattened(List<Type> flatBounds, Type errT) {
4333 List<Type> bounds = closureMin(flatBounds);
4334
4335 if (bounds.isEmpty()) { // length == 0
4336 return syms.objectType;
4337 } else if (bounds.tail.isEmpty()) { // length == 1
4338 return bounds.head;
4339 } else { // length > 1
4340 int classCount = 0;
4341 List<Type> cvars = List.nil();
4342 List<Type> lowers = List.nil();
4343 for (Type bound : bounds) {
4344 if (!bound.isInterface()) {
4345 classCount++;
4346 Type lower = cvarLowerBound(bound);
4347 if (bound != lower && !lower.hasTag(BOT)) {
4348 cvars = cvars.append(bound);
4349 lowers = lowers.append(lower);
4350 }
4351 }
4352 }
4353 if (classCount > 1) {
4354 if (lowers.isEmpty()) {
4355 return createErrorType(errT);
4356 } else {
4357 // try again with lower bounds included instead of capture variables
4358 List<Type> newBounds = bounds.diff(cvars).appendList(lowers);
4359 return glb(newBounds);
4360 }
4361 }
4362 }
4363 return makeIntersectionType(bounds);
4364 }
4365 // </editor-fold>
4366
4367 // <editor-fold defaultstate="collapsed" desc="hashCode">
4368 /**
4369 * Compute a hash code on a type.
4370 */
4371 public int hashCode(Type t) {
4372 return hashCode(t, false);
4373 }
4374
4375 public int hashCode(Type t, boolean strict) {
4376 return strict ?
4377 hashCodeStrictVisitor.visit(t) :
4378 hashCodeVisitor.visit(t);
4379 }
4380 // where
4381 private static final HashCodeVisitor hashCodeVisitor = new HashCodeVisitor();
4382 private static final HashCodeVisitor hashCodeStrictVisitor = new HashCodeVisitor() {
4383 @Override
4384 public Integer visitTypeVar(TypeVar t, Void ignored) {
4385 return System.identityHashCode(t);
4386 }
4387 };
4388
4389 private static class HashCodeVisitor extends UnaryVisitor<Integer> {
4390 public Integer visitType(Type t, Void ignored) {
4391 return t.getTag().ordinal();
4392 }
4393
4394 @Override
4395 public Integer visitClassType(ClassType t, Void ignored) {
4396 int result = visit(t.getEnclosingType());
4397 result *= 127;
4398 result += t.tsym.flatName().hashCode();
4399 for (Type s : t.getTypeArguments()) {
4400 result *= 127;
4401 result += visit(s);
4402 }
4403 return result;
4404 }
4405
4406 @Override
4407 public Integer visitMethodType(MethodType t, Void ignored) {
4408 int h = METHOD.ordinal();
4409 for (List<Type> thisargs = t.argtypes;
4410 thisargs.tail != null;
4411 thisargs = thisargs.tail)
4412 h = (h << 5) + visit(thisargs.head);
4413 return (h << 5) + visit(t.restype);
4414 }
4415
4416 @Override
4417 public Integer visitWildcardType(WildcardType t, Void ignored) {
4418 int result = t.kind.hashCode();
4419 if (t.type != null) {
4420 result *= 127;
4421 result += visit(t.type);
4422 }
4423 return result;
4424 }
4425
4426 @Override
4427 public Integer visitArrayType(ArrayType t, Void ignored) {
4428 return visit(t.elemtype) + 12;
4429 }
4430
4431 @Override
4432 public Integer visitTypeVar(TypeVar t, Void ignored) {
4433 return System.identityHashCode(t);
4434 }
4435
4436 @Override
4437 public Integer visitUndetVar(UndetVar t, Void ignored) {
4438 return System.identityHashCode(t);
4439 }
4440
4441 @Override
4442 public Integer visitErrorType(ErrorType t, Void ignored) {
4443 return 0;
4444 }
4445 }
4446 // </editor-fold>
4447
4448 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable">
4449 /**
4450 * Does t have a result that is a subtype of the result type of s,
4451 * suitable for covariant returns? It is assumed that both types
4452 * are (possibly polymorphic) method types. Monomorphic method
4453 * types are handled in the obvious way. Polymorphic method types
4454 * require renaming all type variables of one to corresponding
4455 * type variables in the other, where correspondence is by
4456 * position in the type parameter list. */
4457 public boolean resultSubtype(Type t, Type s, Warner warner) {
4458 List<Type> tvars = t.getTypeArguments();
4459 List<Type> svars = s.getTypeArguments();
4460 Type tres = t.getReturnType();
4461 Type sres = subst(s.getReturnType(), svars, tvars);
4462 return covariantReturnType(tres, sres, warner);
4463 }
4464
4465 /**
4466 * Return-Type-Substitutable.
4467 * @jls 8.4.5 Method Result
4468 */
4469 public boolean returnTypeSubstitutable(Type r1, Type r2) {
4470 if (hasSameArgs(r1, r2))
4471 return resultSubtype(r1, r2, noWarnings);
4472 else
4473 return covariantReturnType(r1.getReturnType(),
4474 erasure(r2.getReturnType()),
4475 noWarnings);
4476 }
4477
4478 public boolean returnTypeSubstitutable(Type r1,
4479 Type r2, Type r2res,
4480 Warner warner) {
4481 if (isSameType(r1.getReturnType(), r2res))
4482 return true;
4483 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive())
4484 return false;
4485
4486 if (hasSameArgs(r1, r2))
4487 return covariantReturnType(r1.getReturnType(), r2res, warner);
4488 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner))
4489 return true;
4490 if (!isSubtype(r1.getReturnType(), erasure(r2res)))
4491 return false;
4492 warner.warn(LintCategory.UNCHECKED);
4493 return true;
4494 }
4495
4496 /**
4497 * Is t an appropriate return type in an overrider for a
4498 * method that returns s?
4499 */
4500 public boolean covariantReturnType(Type t, Type s, Warner warner) {
4501 return
4502 isSameType(t, s) ||
4503 !t.isPrimitive() &&
4504 !s.isPrimitive() &&
4505 isAssignable(t, s, warner);
4506 }
4507 // </editor-fold>
4508
4509 // <editor-fold defaultstate="collapsed" desc="Box/unbox support">
4510 /**
4511 * Return the class that boxes the given primitive.
4512 */
4513 public ClassSymbol boxedClass(Type t) {
4514 return syms.enterClass(syms.java_base, syms.boxedName[t.getTag().ordinal()]);
4515 }
4516
4517 /**
4518 * Return the boxed type if 't' is primitive, otherwise return 't' itself.
4519 */
4520 public Type boxedTypeOrType(Type t) {
4521 return t.isPrimitive() ?
4522 boxedClass(t).type :
4523 t;
4524 }
4525
4526 /**
4527 * Return the primitive type corresponding to a boxed type.
4528 */
4529 public Type unboxedType(Type t) {
4530 if (t.hasTag(ERROR))
4531 return Type.noType;
4532 for (int i=0; i<syms.boxedName.length; i++) {
4533 Name box = syms.boxedName[i];
4534 if (box != null &&
4535 asSuper(t, syms.enterClass(syms.java_base, box)) != null)
4536 return syms.typeOfTag[i];
4537 }
4538 return Type.noType;
4539 }
4540
4541 /**
4542 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself.
4543 */
4544 public Type unboxedTypeOrType(Type t) {
4545 Type unboxedType = unboxedType(t);
4546 return unboxedType.hasTag(NONE) ? t : unboxedType;
4547 }
4548 // </editor-fold>
4549
4550 // <editor-fold defaultstate="collapsed" desc="Capture conversion">
4551 /*
4552 * JLS 5.1.10 Capture Conversion:
4553 *
4554 * Let G name a generic type declaration with n formal type
4555 * parameters A1 ... An with corresponding bounds U1 ... Un. There
4556 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>,
4557 * where, for 1 <= i <= n:
4558 *
4559 * + If Ti is a wildcard type argument (4.5.1) of the form ? then
4560 * Si is a fresh type variable whose upper bound is
4561 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null
4562 * type.
4563 *
4564 * + If Ti is a wildcard type argument of the form ? extends Bi,
4565 * then Si is a fresh type variable whose upper bound is
4566 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is
4567 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is
4568 * a compile-time error if for any two classes (not interfaces)
4569 * Vi and Vj,Vi is not a subclass of Vj or vice versa.
4570 *
4571 * + If Ti is a wildcard type argument of the form ? super Bi,
4572 * then Si is a fresh type variable whose upper bound is
4573 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi.
4574 *
4575 * + Otherwise, Si = Ti.
4576 *
4577 * Capture conversion on any type other than a parameterized type
4578 * (4.5) acts as an identity conversion (5.1.1). Capture
4579 * conversions never require a special action at run time and
4580 * therefore never throw an exception at run time.
4581 *
4582 * Capture conversion is not applied recursively.
4583 */
4584 /**
4585 * Capture conversion as specified by the JLS.
4586 */
4587
4588 public List<Type> capture(List<Type> ts) {
4589 List<Type> buf = List.nil();
4590 for (Type t : ts) {
4591 buf = buf.prepend(capture(t));
4592 }
4593 return buf.reverse();
4594 }
4595
4596 public Type capture(Type t) {
4597 if (!t.hasTag(CLASS)) {
4598 return t;
4599 }
4600 if (t.getEnclosingType() != Type.noType) {
4601 Type capturedEncl = capture(t.getEnclosingType());
4602 if (capturedEncl != t.getEnclosingType()) {
4603 Type type1 = memberType(capturedEncl, t.tsym);
4604 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments());
4605 }
4606 }
4607 ClassType cls = (ClassType)t;
4608 if (cls.isRaw() || !cls.isParameterized())
4609 return cls;
4610
4611 ClassType G = (ClassType)cls.asElement().asType();
4612 List<Type> A = G.getTypeArguments();
4613 List<Type> T = cls.getTypeArguments();
4614 List<Type> S = freshTypeVariables(T);
4615
4616 List<Type> currentA = A;
4617 List<Type> currentT = T;
4618 List<Type> currentS = S;
4619 boolean captured = false;
4620 while (!currentA.isEmpty() &&
4621 !currentT.isEmpty() &&
4622 !currentS.isEmpty()) {
4623 if (currentS.head != currentT.head) {
4624 captured = true;
4625 WildcardType Ti = (WildcardType)currentT.head;
4626 Type Ui = currentA.head.getUpperBound();
4627 CapturedType Si = (CapturedType)currentS.head;
4628 if (Ui == null)
4629 Ui = syms.objectType;
4630 switch (Ti.kind) {
4631 case UNBOUND:
4632 Si.setUpperBound( subst(Ui, A, S) );
4633 Si.lower = syms.botType;
4634 break;
4635 case EXTENDS:
4636 Si.setUpperBound( glb(Ti.getExtendsBound(), subst(Ui, A, S)) );
4637 Si.lower = syms.botType;
4638 break;
4639 case SUPER:
4640 Si.setUpperBound( subst(Ui, A, S) );
4641 Si.lower = Ti.getSuperBound();
4642 break;
4643 }
4644 Type tmpBound = Si.getUpperBound().hasTag(UNDETVAR) ? ((UndetVar)Si.getUpperBound()).qtype : Si.getUpperBound();
4645 Type tmpLower = Si.lower.hasTag(UNDETVAR) ? ((UndetVar)Si.lower).qtype : Si.lower;
4646 if (!Si.getUpperBound().hasTag(ERROR) &&
4647 !Si.lower.hasTag(ERROR) &&
4648 isSameType(tmpBound, tmpLower)) {
4649 currentS.head = Si.getUpperBound();
4650 }
4651 }
4652 currentA = currentA.tail;
4653 currentT = currentT.tail;
4654 currentS = currentS.tail;
4655 }
4656 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty())
4657 return erasure(t); // some "rare" type involved
4658
4659 if (captured)
4660 return new ClassType(cls.getEnclosingType(), S, cls.tsym,
4661 cls.getMetadata(), cls.getFlavor());
4662 else
4663 return t;
4664 }
4665 // where
4666 public List<Type> freshTypeVariables(List<Type> types) {
4667 ListBuffer<Type> result = new ListBuffer<>();
4668 for (Type t : types) {
4669 if (t.hasTag(WILDCARD)) {
4670 Type bound = ((WildcardType)t).getExtendsBound();
4671 if (bound == null)
4672 bound = syms.objectType;
4673 result.append(new CapturedType(capturedName,
4674 syms.noSymbol,
4675 bound,
4676 syms.botType,
4677 (WildcardType)t));
4678 } else {
4679 result.append(t);
4680 }
4681 }
4682 return result.toList();
4683 }
4684 // </editor-fold>
4685
4686 // <editor-fold defaultstate="collapsed" desc="Internal utility methods">
4687 private boolean sideCast(Type from, Type to, Warner warn) {
4688 // We are casting from type $from$ to type $to$, which are
4689 // non-final unrelated types. This method
4690 // tries to reject a cast by transferring type parameters
4691 // from $to$ to $from$ by common superinterfaces.
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 List<Type> commonSupers = superClosure(to, erasure(from));
4701 boolean giveWarning = commonSupers.isEmpty();
4702 // The arguments to the supers could be unified here to
4703 // get a more accurate analysis
4704 while (commonSupers.nonEmpty()) {
4705 Type t1 = asSuper(from, commonSupers.head.tsym);
4706 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym);
4707 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4708 return false;
4709 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2));
4710 commonSupers = commonSupers.tail;
4711 }
4712 if (giveWarning && !isReifiable(reverse ? from : to))
4713 warn.warn(LintCategory.UNCHECKED);
4714 return true;
4715 }
4716
4717 private boolean sideCastFinal(Type from, Type to, Warner warn) {
4718 // We are casting from type $from$ to type $to$, which are
4719 // unrelated types one of which is final and the other of
4720 // which is an interface. This method
4721 // tries to reject a cast by transferring type parameters
4722 // from the final class to the interface.
4723 boolean reverse = false;
4724 Type target = to;
4725 if ((to.tsym.flags() & INTERFACE) == 0) {
4726 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4727 reverse = true;
4728 to = from;
4729 from = target;
4730 }
4731 Assert.check((from.tsym.flags() & FINAL) != 0);
4732 Type t1 = asSuper(from, to.tsym);
4733 if (t1 == null) return false;
4734 Type t2 = to;
4735 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4736 return false;
4737 if (!isReifiable(target) &&
4738 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)))
4739 warn.warn(LintCategory.UNCHECKED);
4740 return true;
4741 }
4742
4743 private boolean giveWarning(Type from, Type to) {
4744 List<Type> bounds = to.isCompound() ?
4745 directSupertypes(to) : List.of(to);
4746 for (Type b : bounds) {
4747 Type subFrom = asSub(from, b.tsym);
4748 if (b.isParameterized() &&
4749 (!(isUnbounded(b) ||
4750 isSubtype(from, b) ||
4751 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) {
4752 return true;
4753 }
4754 }
4755 return false;
4756 }
4757
4758 private List<Type> superClosure(Type t, Type s) {
4759 List<Type> cl = List.nil();
4760 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
4761 if (isSubtype(s, erasure(l.head))) {
4762 cl = insert(cl, l.head);
4763 } else {
4764 cl = union(cl, superClosure(l.head, s));
4765 }
4766 }
4767 return cl;
4768 }
4769
4770 private boolean containsTypeEquivalent(Type t, Type s) {
4771 return isSameType(t, s) || // shortcut
4772 containsType(t, s) && containsType(s, t);
4773 }
4774
4775 // <editor-fold defaultstate="collapsed" desc="adapt">
4776 /**
4777 * Adapt a type by computing a substitution which maps a source
4778 * type to a target type.
4779 *
4780 * @param source the source type
4781 * @param target the target type
4782 * @param from the type variables of the computed substitution
4783 * @param to the types of the computed substitution.
4784 */
4785 public void adapt(Type source,
4786 Type target,
4787 ListBuffer<Type> from,
4788 ListBuffer<Type> to) throws AdaptFailure {
4789 new Adapter(from, to).adapt(source, target);
4790 }
4791
4792 class Adapter extends SimpleVisitor<Void, Type> {
4793
4794 ListBuffer<Type> from;
4795 ListBuffer<Type> to;
4796 Map<Symbol,Type> mapping;
4797
4798 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) {
4799 this.from = from;
4800 this.to = to;
4801 mapping = new HashMap<>();
4802 }
4803
4804 public void adapt(Type source, Type target) throws AdaptFailure {
4805 visit(source, target);
4806 List<Type> fromList = from.toList();
4807 List<Type> toList = to.toList();
4808 while (!fromList.isEmpty()) {
4809 Type val = mapping.get(fromList.head.tsym);
4810 if (toList.head != val)
4811 toList.head = val;
4812 fromList = fromList.tail;
4813 toList = toList.tail;
4814 }
4815 }
4816
4817 @Override
4818 public Void visitClassType(ClassType source, Type target) throws AdaptFailure {
4819 if (target.hasTag(CLASS))
4820 adaptRecursive(source.allparams(), target.allparams());
4821 return null;
4822 }
4823
4824 @Override
4825 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure {
4826 if (target.hasTag(ARRAY))
4827 adaptRecursive(elemtype(source), elemtype(target));
4828 return null;
4829 }
4830
4831 @Override
4832 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure {
4833 if (source.isExtendsBound())
4834 adaptRecursive(wildUpperBound(source), wildUpperBound(target));
4835 else if (source.isSuperBound())
4836 adaptRecursive(wildLowerBound(source), wildLowerBound(target));
4837 return null;
4838 }
4839
4840 @Override
4841 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure {
4842 // Check to see if there is
4843 // already a mapping for $source$, in which case
4844 // the old mapping will be merged with the new
4845 Type val = mapping.get(source.tsym);
4846 if (val != null) {
4847 if (val.isSuperBound() && target.isSuperBound()) {
4848 val = isSubtype(wildLowerBound(val), wildLowerBound(target))
4849 ? target : val;
4850 } else if (val.isExtendsBound() && target.isExtendsBound()) {
4851 val = isSubtype(wildUpperBound(val), wildUpperBound(target))
4852 ? val : target;
4853 } else if (!isSameType(val, target)) {
4854 throw new AdaptFailure();
4855 }
4856 } else {
4857 val = target;
4858 from.append(source);
4859 to.append(target);
4860 }
4861 mapping.put(source.tsym, val);
4862 return null;
4863 }
4864
4865 @Override
4866 public Void visitType(Type source, Type target) {
4867 return null;
4868 }
4869
4870 private Set<TypePair> cache = new HashSet<>();
4871
4872 private void adaptRecursive(Type source, Type target) {
4873 TypePair pair = new TypePair(source, target);
4874 if (cache.add(pair)) {
4875 try {
4876 visit(source, target);
4877 } finally {
4878 cache.remove(pair);
4879 }
4880 }
4881 }
4882
4883 private void adaptRecursive(List<Type> source, List<Type> target) {
4884 if (source.length() == target.length()) {
4885 while (source.nonEmpty()) {
4886 adaptRecursive(source.head, target.head);
4887 source = source.tail;
4888 target = target.tail;
4889 }
4890 }
4891 }
4892 }
4893
4894 public static class AdaptFailure extends RuntimeException {
4895 static final long serialVersionUID = -7490231548272701566L;
4896 }
4897
4898 private void adaptSelf(Type t,
4899 ListBuffer<Type> from,
4900 ListBuffer<Type> to) {
4901 try {
4902 //if (t.tsym.type != t)
4903 adapt(t.tsym.type, t, from, to);
4904 } catch (AdaptFailure ex) {
4905 // Adapt should never fail calculating a mapping from
4906 // t.tsym.type to t as there can be no merge problem.
4907 throw new AssertionError(ex);
4908 }
4909 }
4910 // </editor-fold>
4911
4912 /**
4913 * Rewrite all type variables (universal quantifiers) in the given
4914 * type to wildcards (existential quantifiers). This is used to
4915 * determine if a cast is allowed. For example, if high is true
4916 * and {@code T <: Number}, then {@code List<T>} is rewritten to
4917 * {@code List<? extends Number>}. Since {@code List<Integer> <:
4918 * List<? extends Number>} a {@code List<T>} can be cast to {@code
4919 * List<Integer>} with a warning.
4920 * @param t a type
4921 * @param high if true return an upper bound; otherwise a lower
4922 * bound
4923 * @param rewriteTypeVars only rewrite captured wildcards if false;
4924 * otherwise rewrite all type variables
4925 * @return the type rewritten with wildcards (existential
4926 * quantifiers) only
4927 */
4928 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) {
4929 return new Rewriter(high, rewriteTypeVars).visit(t);
4930 }
4931
4932 class Rewriter extends UnaryVisitor<Type> {
4933
4934 boolean high;
4935 boolean rewriteTypeVars;
4936
4937 Rewriter(boolean high, boolean rewriteTypeVars) {
4938 this.high = high;
4939 this.rewriteTypeVars = rewriteTypeVars;
4940 }
4941
4942 @Override
4943 public Type visitClassType(ClassType t, Void s) {
4944 ListBuffer<Type> rewritten = new ListBuffer<>();
4945 boolean changed = false;
4946 for (Type arg : t.allparams()) {
4947 Type bound = visit(arg);
4948 if (arg != bound) {
4949 changed = true;
4950 }
4951 rewritten.append(bound);
4952 }
4953 if (changed)
4954 return subst(t.tsym.type,
4955 t.tsym.type.allparams(),
4956 rewritten.toList());
4957 else
4958 return t;
4959 }
4960
4961 public Type visitType(Type t, Void s) {
4962 return t;
4963 }
4964
4965 @Override
4966 public Type visitCapturedType(CapturedType t, Void s) {
4967 Type w_bound = t.wildcard.type;
4968 Type bound = w_bound.contains(t) ?
4969 erasure(w_bound) :
4970 visit(w_bound);
4971 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind);
4972 }
4973
4974 @Override
4975 public Type visitTypeVar(TypeVar t, Void s) {
4976 if (rewriteTypeVars) {
4977 Type bound = t.getUpperBound().contains(t) ?
4978 erasure(t.getUpperBound()) :
4979 visit(t.getUpperBound());
4980 return rewriteAsWildcardType(bound, t, EXTENDS);
4981 } else {
4982 return t;
4983 }
4984 }
4985
4986 @Override
4987 public Type visitWildcardType(WildcardType t, Void s) {
4988 Type bound2 = visit(t.type);
4989 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind);
4990 }
4991
4992 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) {
4993 switch (bk) {
4994 case EXTENDS: return high ?
4995 makeExtendsWildcard(B(bound), formal) :
4996 makeExtendsWildcard(syms.objectType, formal);
4997 case SUPER: return high ?
4998 makeSuperWildcard(syms.botType, formal) :
4999 makeSuperWildcard(B(bound), formal);
5000 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal);
5001 default:
5002 Assert.error("Invalid bound kind " + bk);
5003 return null;
5004 }
5005 }
5006
5007 Type B(Type t) {
5008 while (t.hasTag(WILDCARD)) {
5009 WildcardType w = (WildcardType)t;
5010 t = high ?
5011 w.getExtendsBound() :
5012 w.getSuperBound();
5013 if (t == null) {
5014 t = high ? syms.objectType : syms.botType;
5015 }
5016 }
5017 return t;
5018 }
5019 }
5020
5021
5022 /**
5023 * Create a wildcard with the given upper (extends) bound; create
5024 * an unbounded wildcard if bound is Object.
5025 *
5026 * @param bound the upper bound
5027 * @param formal the formal type parameter that will be
5028 * substituted by the wildcard
5029 */
5030 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) {
5031 if (bound == syms.objectType) {
5032 return new WildcardType(syms.objectType,
5033 BoundKind.UNBOUND,
5034 syms.boundClass,
5035 formal);
5036 } else {
5037 return new WildcardType(bound,
5038 BoundKind.EXTENDS,
5039 syms.boundClass,
5040 formal);
5041 }
5042 }
5043
5044 /**
5045 * Create a wildcard with the given lower (super) bound; create an
5046 * unbounded wildcard if bound is bottom (type of {@code null}).
5047 *
5048 * @param bound the lower bound
5049 * @param formal the formal type parameter that will be
5050 * substituted by the wildcard
5051 */
5052 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) {
5053 if (bound.hasTag(BOT)) {
5054 return new WildcardType(syms.objectType,
5055 BoundKind.UNBOUND,
5056 syms.boundClass,
5057 formal);
5058 } else {
5059 return new WildcardType(bound,
5060 BoundKind.SUPER,
5061 syms.boundClass,
5062 formal);
5063 }
5064 }
5065
5066 /**
5067 * A wrapper for a type that allows use in sets.
5068 */
5069 public static class UniqueType {
5070 public final Type type;
5071 final Types types;
5072 private boolean encodeTypeSig;
5073
5074 public UniqueType(Type type, Types types, boolean encodeTypeSig) {
5075 this.type = type;
5076 this.types = types;
5077 this.encodeTypeSig = encodeTypeSig;
5078 }
5079
5080 public UniqueType(Type type, Types types) {
5081 this(type, types, true);
5082 }
5083
5084 public int hashCode() {
5085 return types.hashCode(type);
5086 }
5087
5088 public boolean equals(Object obj) {
5089 return (obj instanceof UniqueType uniqueType) &&
5090 types.isSameType(type, uniqueType.type);
5091 }
5092
5093 public boolean encodeTypeSig() {
5094 return encodeTypeSig;
5095 }
5096
5097 public String toString() {
5098 return type.toString();
5099 }
5100
5101 }
5102 // </editor-fold>
5103
5104 // <editor-fold defaultstate="collapsed" desc="Visitors">
5105 /**
5106 * A default visitor for types. All visitor methods except
5107 * visitType are implemented by delegating to visitType. Concrete
5108 * subclasses must provide an implementation of visitType and can
5109 * override other methods as needed.
5110 *
5111 * @param <R> the return type of the operation implemented by this
5112 * visitor; use Void if no return type is needed.
5113 * @param <S> the type of the second argument (the first being the
5114 * type itself) of the operation implemented by this visitor; use
5115 * Void if a second argument is not needed.
5116 */
5117 public static abstract class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> {
5118 public final R visit(Type t, S s) { return t.accept(this, s); }
5119 public R visitClassType(ClassType t, S s) { return visitType(t, s); }
5120 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); }
5121 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); }
5122 public R visitMethodType(MethodType t, S s) { return visitType(t, s); }
5123 public R visitPackageType(PackageType t, S s) { return visitType(t, s); }
5124 public R visitModuleType(ModuleType t, S s) { return visitType(t, s); }
5125 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); }
5126 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); }
5127 public R visitForAll(ForAll t, S s) { return visitType(t, s); }
5128 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); }
5129 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); }
5130 }
5131
5132 /**
5133 * A default visitor for symbols. All visitor methods except
5134 * visitSymbol are implemented by delegating to visitSymbol. Concrete
5135 * subclasses must provide an implementation of visitSymbol and can
5136 * override other methods as needed.
5137 *
5138 * @param <R> the return type of the operation implemented by this
5139 * visitor; use Void if no return type is needed.
5140 * @param <S> the type of the second argument (the first being the
5141 * symbol itself) of the operation implemented by this visitor; use
5142 * Void if a second argument is not needed.
5143 */
5144 public static abstract class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> {
5145 public final R visit(Symbol s, S arg) { return s.accept(this, arg); }
5146 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); }
5147 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); }
5148 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); }
5149 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); }
5150 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); }
5151 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); }
5152 }
5153
5154 /**
5155 * A <em>simple</em> visitor for types. This visitor is simple as
5156 * captured wildcards, for-all types (generic methods), and
5157 * undetermined type variables (part of inference) are hidden.
5158 * Captured wildcards are hidden by treating them as type
5159 * variables and the rest are hidden by visiting their qtypes.
5160 *
5161 * @param <R> the return type of the operation implemented by this
5162 * visitor; use Void if no return type is needed.
5163 * @param <S> the type of the second argument (the first being the
5164 * type itself) of the operation implemented by this visitor; use
5165 * Void if a second argument is not needed.
5166 */
5167 public static abstract class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> {
5168 @Override
5169 public R visitCapturedType(CapturedType t, S s) {
5170 return visitTypeVar(t, s);
5171 }
5172 @Override
5173 public R visitForAll(ForAll t, S s) {
5174 return visit(t.qtype, s);
5175 }
5176 @Override
5177 public R visitUndetVar(UndetVar t, S s) {
5178 return visit(t.qtype, s);
5179 }
5180 }
5181
5182 /**
5183 * A plain relation on types. That is a 2-ary function on the
5184 * form Type × Type → Boolean.
5185 * <!-- In plain text: Type x Type -> Boolean -->
5186 */
5187 public static abstract class TypeRelation extends SimpleVisitor<Boolean,Type> {}
5188
5189 /**
5190 * A convenience visitor for implementing operations that only
5191 * require one argument (the type itself), that is, unary
5192 * operations.
5193 *
5194 * @param <R> the return type of the operation implemented by this
5195 * visitor; use Void if no return type is needed.
5196 */
5197 public static abstract class UnaryVisitor<R> extends SimpleVisitor<R,Void> {
5198 public final R visit(Type t) { return t.accept(this, null); }
5199 }
5200
5201 /**
5202 * A visitor for implementing a mapping from types to types. The
5203 * default behavior of this class is to implement the identity
5204 * mapping (mapping a type to itself). This can be overridden in
5205 * subclasses.
5206 *
5207 * @param <S> the type of the second argument (the first being the
5208 * type itself) of this mapping; use Void if a second argument is
5209 * not needed.
5210 */
5211 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> {
5212 public final Type visit(Type t) { return t.accept(this, null); }
5213 public Type visitType(Type t, S s) { return t; }
5214 }
5215
5216 /**
5217 * An abstract class for mappings from types to types (see {@link Type#map(TypeMapping)}.
5218 * This class implements the functional interface {@code Function}, that allows it to be used
5219 * fluently in stream-like processing.
5220 */
5221 public static class TypeMapping<S> extends MapVisitor<S> implements Function<Type, Type> {
5222 @Override
5223 public Type apply(Type type) { return visit(type); }
5224
5225 List<Type> visit(List<Type> ts, S s) {
5226 return ts.map(t -> visit(t, s));
5227 }
5228
5229 @Override
5230 public Type visitCapturedType(CapturedType t, S s) {
5231 return visitTypeVar(t, s);
5232 }
5233 }
5234 // </editor-fold>
5235
5236
5237 // <editor-fold defaultstate="collapsed" desc="Annotation support">
5238
5239 public RetentionPolicy getRetention(Attribute.Compound a) {
5240 return getRetention(a.type.tsym);
5241 }
5242
5243 public RetentionPolicy getRetention(TypeSymbol sym) {
5244 RetentionPolicy vis = RetentionPolicy.CLASS; // the default
5245 Attribute.Compound c = sym.attribute(syms.retentionType.tsym);
5246 if (c != null) {
5247 Attribute value = c.member(names.value);
5248 if (value != null && value instanceof Attribute.Enum attributeEnum) {
5249 Name levelName = attributeEnum.value.name;
5250 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE;
5251 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS;
5252 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME;
5253 else ;// /* fail soft */ throw new AssertionError(levelName);
5254 }
5255 }
5256 return vis;
5257 }
5258 // </editor-fold>
5259
5260 // <editor-fold defaultstate="collapsed" desc="Signature Generation">
5261
5262 public static abstract class SignatureGenerator {
5263
5264 public static class InvalidSignatureException extends RuntimeException {
5265 private static final long serialVersionUID = 0;
5266
5267 private final transient Type type;
5268
5269 InvalidSignatureException(Type type) {
5270 this.type = type;
5271 }
5272
5273 public Type type() {
5274 return type;
5275 }
5276 }
5277
5278 private final Types types;
5279
5280 protected abstract void append(char ch);
5281 protected abstract void append(byte[] ba);
5282 protected abstract void append(Name name);
5283 protected void classReference(ClassSymbol c) { /* by default: no-op */ }
5284
5285 protected SignatureGenerator(Types types) {
5286 this.types = types;
5287 }
5288
5289 protected void reportIllegalSignature(Type t) {
5290 throw new InvalidSignatureException(t);
5291 }
5292
5293 /**
5294 * Assemble signature of given type in string buffer.
5295 */
5296 public void assembleSig(Type type) {
5297 switch (type.getTag()) {
5298 case BYTE:
5299 append('B');
5300 break;
5301 case SHORT:
5302 append('S');
5303 break;
5304 case CHAR:
5305 append('C');
5306 break;
5307 case INT:
5308 append('I');
5309 break;
5310 case LONG:
5311 append('J');
5312 break;
5313 case FLOAT:
5314 append('F');
5315 break;
5316 case DOUBLE:
5317 append('D');
5318 break;
5319 case BOOLEAN:
5320 append('Z');
5321 break;
5322 case VOID:
5323 append('V');
5324 break;
5325 case CLASS:
5326 if (type.isCompound()) {
5327 reportIllegalSignature(type);
5328 }
5329 if (types.isPrimitiveClass(type))
5330 append('Q');
5331 else
5332 append('L');
5333 assembleClassSig(type);
5334 append(';');
5335 break;
5336 case ARRAY:
5337 ArrayType at = (ArrayType) type;
5338 append('[');
5339 assembleSig(at.elemtype);
5340 break;
5341 case METHOD:
5342 MethodType mt = (MethodType) type;
5343 append('(');
5344 assembleSig(mt.argtypes);
5345 append(')');
5346 assembleSig(mt.restype);
5347 if (hasTypeVar(mt.thrown)) {
5348 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) {
5349 append('^');
5350 assembleSig(l.head);
5351 }
5352 }
5353 break;
5354 case WILDCARD: {
5355 Type.WildcardType ta = (Type.WildcardType) type;
5356 switch (ta.kind) {
5357 case SUPER:
5358 append('-');
5359 assembleSig(ta.type);
5360 break;
5361 case EXTENDS:
5362 append('+');
5363 assembleSig(ta.type);
5364 break;
5365 case UNBOUND:
5366 append('*');
5367 break;
5368 default:
5369 throw new AssertionError(ta.kind);
5370 }
5371 break;
5372 }
5373 case TYPEVAR:
5374 if (((TypeVar)type).isCaptured()) {
5375 reportIllegalSignature(type);
5376 }
5377 append('T');
5378 append(type.tsym.name);
5379 append(';');
5380 break;
5381 case FORALL:
5382 Type.ForAll ft = (Type.ForAll) type;
5383 assembleParamsSig(ft.tvars);
5384 assembleSig(ft.qtype);
5385 break;
5386 default:
5387 throw new AssertionError("typeSig " + type.getTag());
5388 }
5389 }
5390
5391 public boolean hasTypeVar(List<Type> l) {
5392 while (l.nonEmpty()) {
5393 if (l.head.hasTag(TypeTag.TYPEVAR)) {
5394 return true;
5395 }
5396 l = l.tail;
5397 }
5398 return false;
5399 }
5400
5401 public void assembleClassSig(Type type) {
5402 ClassType ct = (ClassType) type;
5403 ClassSymbol c = (ClassSymbol) ct.tsym;
5404 classReference(c);
5405 Type outer = ct.getEnclosingType();
5406 if (outer.allparams().nonEmpty()) {
5407 boolean rawOuter =
5408 c.owner.kind == MTH || // either a local class
5409 c.name == types.names.empty; // or anonymous
5410 assembleClassSig(rawOuter
5411 ? types.erasure(outer)
5412 : outer);
5413 append(rawOuter ? '$' : '.');
5414 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname));
5415 append(rawOuter
5416 ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength())
5417 : c.name);
5418 } else {
5419 append(externalize(c.flatname));
5420 }
5421 if (ct.getTypeArguments().nonEmpty()) {
5422 append('<');
5423 assembleSig(ct.getTypeArguments());
5424 append('>');
5425 }
5426 }
5427
5428 public void assembleParamsSig(List<Type> typarams) {
5429 append('<');
5430 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) {
5431 Type.TypeVar tvar = (Type.TypeVar) ts.head;
5432 append(tvar.tsym.name);
5433 List<Type> bounds = types.getBounds(tvar);
5434 if ((bounds.head.tsym.flags() & INTERFACE) != 0) {
5435 append(':');
5436 }
5437 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) {
5438 append(':');
5439 assembleSig(l.head);
5440 }
5441 }
5442 append('>');
5443 }
5444
5445 public void assembleSig(List<Type> types) {
5446 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) {
5447 assembleSig(ts.head);
5448 }
5449 }
5450 }
5451
5452 public Type constantType(LoadableConstant c) {
5453 switch (c.poolTag()) {
5454 case ClassFile.CONSTANT_Class:
5455 return syms.classType;
5456 case ClassFile.CONSTANT_String:
5457 return syms.stringType;
5458 case ClassFile.CONSTANT_Integer:
5459 return syms.intType;
5460 case ClassFile.CONSTANT_Float:
5461 return syms.floatType;
5462 case ClassFile.CONSTANT_Long:
5463 return syms.longType;
5464 case ClassFile.CONSTANT_Double:
5465 return syms.doubleType;
5466 case ClassFile.CONSTANT_MethodHandle:
5467 return syms.methodHandleType;
5468 case ClassFile.CONSTANT_MethodType:
5469 return syms.methodTypeType;
5470 case ClassFile.CONSTANT_Dynamic:
5471 return ((DynamicVarSymbol)c).type;
5472 default:
5473 throw new AssertionError("Not a loadable constant: " + c.poolTag());
5474 }
5475 }
5476 // </editor-fold>
5477
5478 public void newRound() {
5479 descCache._map.clear();
5480 isDerivedRawCache.clear();
5481 implCache._map.clear();
5482 membersCache._map.clear();
5483 closureCache.clear();
5484 }
5485 }