Mercurial > jdk8-mips64-public > langtools / file revision
src/share/classes/com/sun/tools/javac/code/Types.java@27a3026256cd
src/share/classes/com/sun/tools/javac/code/Types.java
Wed, 19 Mar 2014 16:44:49 +0000
- author
- vromero
- date
- Wed, 19 Mar 2014 16:44:49 +0000
- changeset 2301
- 27a3026256cd
- parent 2260
- fb870c70e774
- child 2382
- 14979dd5e034
- permissions
- -rw-r--r--
8034924: Incorrect inheritance of inaccessible static method
Reviewed-by: jjg, jlahoda
1 /*
2 * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
26 package com.sun.tools.javac.code;
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.Set;
34 import java.util.WeakHashMap;
36 import javax.tools.JavaFileObject;
38 import com.sun.tools.javac.code.Attribute.RetentionPolicy;
39 import com.sun.tools.javac.code.Lint.LintCategory;
40 import com.sun.tools.javac.code.Type.UndetVar.InferenceBound;
41 import com.sun.tools.javac.comp.AttrContext;
42 import com.sun.tools.javac.comp.Check;
43 import com.sun.tools.javac.comp.Enter;
44 import com.sun.tools.javac.comp.Env;
45 import com.sun.tools.javac.jvm.ClassReader;
46 import com.sun.tools.javac.util.*;
47 import static com.sun.tools.javac.code.BoundKind.*;
48 import static com.sun.tools.javac.code.Flags.*;
49 import static com.sun.tools.javac.code.Scope.*;
50 import static com.sun.tools.javac.code.Symbol.*;
51 import static com.sun.tools.javac.code.Type.*;
52 import static com.sun.tools.javac.code.TypeTag.*;
53 import static com.sun.tools.javac.jvm.ClassFile.externalize;
55 /**
56 * Utility class containing various operations on types.
57 *
58 * <p>Unless other names are more illustrative, the following naming
59 * conventions should be observed in this file:
60 *
61 * <dl>
62 * <dt>t</dt>
63 * <dd>If the first argument to an operation is a type, it should be named t.</dd>
64 * <dt>s</dt>
65 * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd>
66 * <dt>ts</dt>
67 * <dd>If an operations takes a list of types, the first should be named ts.</dd>
68 * <dt>ss</dt>
69 * <dd>A second list of types should be named ss.</dd>
70 * </dl>
71 *
72 * <p><b>This is NOT part of any supported API.
73 * If you write code that depends on this, you do so at your own risk.
74 * This code and its internal interfaces are subject to change or
75 * deletion without notice.</b>
76 */
77 public class Types {
78 protected static final Context.Key<Types> typesKey =
79 new Context.Key<Types>();
81 final Symtab syms;
82 final JavacMessages messages;
83 final Names names;
84 final boolean allowBoxing;
85 final boolean allowCovariantReturns;
86 final boolean allowObjectToPrimitiveCast;
87 final ClassReader reader;
88 final Check chk;
89 final Enter enter;
90 JCDiagnostic.Factory diags;
91 List<Warner> warnStack = List.nil();
92 final Name capturedName;
93 private final FunctionDescriptorLookupError functionDescriptorLookupError;
95 public final Warner noWarnings;
97 // <editor-fold defaultstate="collapsed" desc="Instantiating">
98 public static Types instance(Context context) {
99 Types instance = context.get(typesKey);
100 if (instance == null)
101 instance = new Types(context);
102 return instance;
103 }
105 protected Types(Context context) {
106 context.put(typesKey, this);
107 syms = Symtab.instance(context);
108 names = Names.instance(context);
109 Source source = Source.instance(context);
110 allowBoxing = source.allowBoxing();
111 allowCovariantReturns = source.allowCovariantReturns();
112 allowObjectToPrimitiveCast = source.allowObjectToPrimitiveCast();
113 reader = ClassReader.instance(context);
114 chk = Check.instance(context);
115 enter = Enter.instance(context);
116 capturedName = names.fromString("<captured wildcard>");
117 messages = JavacMessages.instance(context);
118 diags = JCDiagnostic.Factory.instance(context);
119 functionDescriptorLookupError = new FunctionDescriptorLookupError();
120 noWarnings = new Warner(null);
121 }
122 // </editor-fold>
124 // <editor-fold defaultstate="collapsed" desc="upperBound">
125 /**
126 * The "rvalue conversion".<br>
127 * The upper bound of most types is the type
128 * itself. Wildcards, on the other hand have upper
129 * and lower bounds.
130 * @param t a type
131 * @return the upper bound of the given type
132 */
133 public Type upperBound(Type t) {
134 return upperBound.visit(t).unannotatedType();
135 }
136 // where
137 private final MapVisitor<Void> upperBound = new MapVisitor<Void>() {
139 @Override
140 public Type visitWildcardType(WildcardType t, Void ignored) {
141 if (t.isSuperBound())
142 return t.bound == null ? syms.objectType : t.bound.bound;
143 else
144 return visit(t.type);
145 }
147 @Override
148 public Type visitCapturedType(CapturedType t, Void ignored) {
149 return visit(t.bound);
150 }
151 };
152 // </editor-fold>
154 // <editor-fold defaultstate="collapsed" desc="lowerBound">
155 /**
156 * The "lvalue conversion".<br>
157 * The lower bound of most types is the type
158 * itself. Wildcards, on the other hand have upper
159 * and lower bounds.
160 * @param t a type
161 * @return the lower bound of the given type
162 */
163 public Type lowerBound(Type t) {
164 return lowerBound.visit(t);
165 }
166 // where
167 private final MapVisitor<Void> lowerBound = new MapVisitor<Void>() {
169 @Override
170 public Type visitWildcardType(WildcardType t, Void ignored) {
171 return t.isExtendsBound() ? syms.botType : visit(t.type);
172 }
174 @Override
175 public Type visitCapturedType(CapturedType t, Void ignored) {
176 return visit(t.getLowerBound());
177 }
178 };
179 // </editor-fold>
181 // <editor-fold defaultstate="collapsed" desc="isUnbounded">
182 /**
183 * Checks that all the arguments to a class are unbounded
184 * wildcards or something else that doesn't make any restrictions
185 * on the arguments. If a class isUnbounded, a raw super- or
186 * subclass can be cast to it without a warning.
187 * @param t a type
188 * @return true iff the given type is unbounded or raw
189 */
190 public boolean isUnbounded(Type t) {
191 return isUnbounded.visit(t);
192 }
193 // where
194 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() {
196 public Boolean visitType(Type t, Void ignored) {
197 return true;
198 }
200 @Override
201 public Boolean visitClassType(ClassType t, Void ignored) {
202 List<Type> parms = t.tsym.type.allparams();
203 List<Type> args = t.allparams();
204 while (parms.nonEmpty()) {
205 WildcardType unb = new WildcardType(syms.objectType,
206 BoundKind.UNBOUND,
207 syms.boundClass,
208 (TypeVar)parms.head.unannotatedType());
209 if (!containsType(args.head, unb))
210 return false;
211 parms = parms.tail;
212 args = args.tail;
213 }
214 return true;
215 }
216 };
217 // </editor-fold>
219 // <editor-fold defaultstate="collapsed" desc="asSub">
220 /**
221 * Return the least specific subtype of t that starts with symbol
222 * sym. If none exists, return null. The least specific subtype
223 * is determined as follows:
224 *
225 * <p>If there is exactly one parameterized instance of sym that is a
226 * subtype of t, that parameterized instance is returned.<br>
227 * Otherwise, if the plain type or raw type `sym' is a subtype of
228 * type t, the type `sym' itself is returned. Otherwise, null is
229 * returned.
230 */
231 public Type asSub(Type t, Symbol sym) {
232 return asSub.visit(t, sym);
233 }
234 // where
235 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() {
237 public Type visitType(Type t, Symbol sym) {
238 return null;
239 }
241 @Override
242 public Type visitClassType(ClassType t, Symbol sym) {
243 if (t.tsym == sym)
244 return t;
245 Type base = asSuper(sym.type, t.tsym);
246 if (base == null)
247 return null;
248 ListBuffer<Type> from = new ListBuffer<Type>();
249 ListBuffer<Type> to = new ListBuffer<Type>();
250 try {
251 adapt(base, t, from, to);
252 } catch (AdaptFailure ex) {
253 return null;
254 }
255 Type res = subst(sym.type, from.toList(), to.toList());
256 if (!isSubtype(res, t))
257 return null;
258 ListBuffer<Type> openVars = new ListBuffer<Type>();
259 for (List<Type> l = sym.type.allparams();
260 l.nonEmpty(); l = l.tail)
261 if (res.contains(l.head) && !t.contains(l.head))
262 openVars.append(l.head);
263 if (openVars.nonEmpty()) {
264 if (t.isRaw()) {
265 // The subtype of a raw type is raw
266 res = erasure(res);
267 } else {
268 // Unbound type arguments default to ?
269 List<Type> opens = openVars.toList();
270 ListBuffer<Type> qs = new ListBuffer<Type>();
271 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) {
272 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, syms.boundClass, (TypeVar) iter.head.unannotatedType()));
273 }
274 res = subst(res, opens, qs.toList());
275 }
276 }
277 return res;
278 }
280 @Override
281 public Type visitErrorType(ErrorType t, Symbol sym) {
282 return t;
283 }
284 };
285 // </editor-fold>
287 // <editor-fold defaultstate="collapsed" desc="isConvertible">
288 /**
289 * Is t a subtype of or convertible via boxing/unboxing
290 * conversion to s?
291 */
292 public boolean isConvertible(Type t, Type s, Warner warn) {
293 if (t.hasTag(ERROR)) {
294 return true;
295 }
296 boolean tPrimitive = t.isPrimitive();
297 boolean sPrimitive = s.isPrimitive();
298 if (tPrimitive == sPrimitive) {
299 return isSubtypeUnchecked(t, s, warn);
300 }
301 if (!allowBoxing) return false;
302 return tPrimitive
303 ? isSubtype(boxedClass(t).type, s)
304 : isSubtype(unboxedType(t), s);
305 }
307 /**
308 * Is t a subtype of or convertiable via boxing/unboxing
309 * convertions to s?
310 */
311 public boolean isConvertible(Type t, Type s) {
312 return isConvertible(t, s, noWarnings);
313 }
314 // </editor-fold>
316 // <editor-fold defaultstate="collapsed" desc="findSam">
318 /**
319 * Exception used to report a function descriptor lookup failure. The exception
320 * wraps a diagnostic that can be used to generate more details error
321 * messages.
322 */
323 public static class FunctionDescriptorLookupError extends RuntimeException {
324 private static final long serialVersionUID = 0;
326 JCDiagnostic diagnostic;
328 FunctionDescriptorLookupError() {
329 this.diagnostic = null;
330 }
332 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) {
333 this.diagnostic = diag;
334 return this;
335 }
337 public JCDiagnostic getDiagnostic() {
338 return diagnostic;
339 }
340 }
342 /**
343 * A cache that keeps track of function descriptors associated with given
344 * functional interfaces.
345 */
346 class DescriptorCache {
348 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<TypeSymbol, Entry>();
350 class FunctionDescriptor {
351 Symbol descSym;
353 FunctionDescriptor(Symbol descSym) {
354 this.descSym = descSym;
355 }
357 public Symbol getSymbol() {
358 return descSym;
359 }
361 public Type getType(Type site) {
362 site = removeWildcards(site);
363 if (!chk.checkValidGenericType(site)) {
364 //if the inferred functional interface type is not well-formed,
365 //or if it's not a subtype of the original target, issue an error
366 throw failure(diags.fragment("no.suitable.functional.intf.inst", site));
367 }
368 return memberType(site, descSym);
369 }
370 }
372 class Entry {
373 final FunctionDescriptor cachedDescRes;
374 final int prevMark;
376 public Entry(FunctionDescriptor cachedDescRes,
377 int prevMark) {
378 this.cachedDescRes = cachedDescRes;
379 this.prevMark = prevMark;
380 }
382 boolean matches(int mark) {
383 return this.prevMark == mark;
384 }
385 }
387 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError {
388 Entry e = _map.get(origin);
389 CompoundScope members = membersClosure(origin.type, false);
390 if (e == null ||
391 !e.matches(members.getMark())) {
392 FunctionDescriptor descRes = findDescriptorInternal(origin, members);
393 _map.put(origin, new Entry(descRes, members.getMark()));
394 return descRes;
395 }
396 else {
397 return e.cachedDescRes;
398 }
399 }
401 /**
402 * Compute the function descriptor associated with a given functional interface
403 */
404 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin,
405 CompoundScope membersCache) throws FunctionDescriptorLookupError {
406 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0) {
407 //t must be an interface
408 throw failure("not.a.functional.intf", origin);
409 }
411 final ListBuffer<Symbol> abstracts = new ListBuffer<>();
412 for (Symbol sym : membersCache.getElements(new DescriptorFilter(origin))) {
413 Type mtype = memberType(origin.type, sym);
414 if (abstracts.isEmpty() ||
415 (sym.name == abstracts.first().name &&
416 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) {
417 abstracts.append(sym);
418 } else {
419 //the target method(s) should be the only abstract members of t
420 throw failure("not.a.functional.intf.1", origin,
421 diags.fragment("incompatible.abstracts", Kinds.kindName(origin), origin));
422 }
423 }
424 if (abstracts.isEmpty()) {
425 //t must define a suitable non-generic method
426 throw failure("not.a.functional.intf.1", origin,
427 diags.fragment("no.abstracts", Kinds.kindName(origin), origin));
428 } else if (abstracts.size() == 1) {
429 return new FunctionDescriptor(abstracts.first());
430 } else { // size > 1
431 FunctionDescriptor descRes = mergeDescriptors(origin, abstracts.toList());
432 if (descRes == null) {
433 //we can get here if the functional interface is ill-formed
434 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>();
435 for (Symbol desc : abstracts) {
436 String key = desc.type.getThrownTypes().nonEmpty() ?
437 "descriptor.throws" : "descriptor";
438 descriptors.append(diags.fragment(key, desc.name,
439 desc.type.getParameterTypes(),
440 desc.type.getReturnType(),
441 desc.type.getThrownTypes()));
442 }
443 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors =
444 new JCDiagnostic.MultilineDiagnostic(diags.fragment("incompatible.descs.in.functional.intf",
445 Kinds.kindName(origin), origin), descriptors.toList());
446 throw failure(incompatibleDescriptors);
447 }
448 return descRes;
449 }
450 }
452 /**
453 * Compute a synthetic type for the target descriptor given a list
454 * of override-equivalent methods in the functional interface type.
455 * The resulting method type is a method type that is override-equivalent
456 * and return-type substitutable with each method in the original list.
457 */
458 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) {
459 //pick argument types - simply take the signature that is a
460 //subsignature of all other signatures in the list (as per JLS 8.4.2)
461 List<Symbol> mostSpecific = List.nil();
462 outer: for (Symbol msym1 : methodSyms) {
463 Type mt1 = memberType(origin.type, msym1);
464 for (Symbol msym2 : methodSyms) {
465 Type mt2 = memberType(origin.type, msym2);
466 if (!isSubSignature(mt1, mt2)) {
467 continue outer;
468 }
469 }
470 mostSpecific = mostSpecific.prepend(msym1);
471 }
472 if (mostSpecific.isEmpty()) {
473 return null;
474 }
477 //pick return types - this is done in two phases: (i) first, the most
478 //specific return type is chosen using strict subtyping; if this fails,
479 //a second attempt is made using return type substitutability (see JLS 8.4.5)
480 boolean phase2 = false;
481 Symbol bestSoFar = null;
482 while (bestSoFar == null) {
483 outer: for (Symbol msym1 : mostSpecific) {
484 Type mt1 = memberType(origin.type, msym1);
485 for (Symbol msym2 : methodSyms) {
486 Type mt2 = memberType(origin.type, msym2);
487 if (phase2 ?
488 !returnTypeSubstitutable(mt1, mt2) :
489 !isSubtypeInternal(mt1.getReturnType(), mt2.getReturnType())) {
490 continue outer;
491 }
492 }
493 bestSoFar = msym1;
494 }
495 if (phase2) {
496 break;
497 } else {
498 phase2 = true;
499 }
500 }
501 if (bestSoFar == null) return null;
503 //merge thrown types - form the intersection of all the thrown types in
504 //all the signatures in the list
505 boolean toErase = !bestSoFar.type.hasTag(FORALL);
506 List<Type> thrown = null;
507 Type mt1 = memberType(origin.type, bestSoFar);
508 for (Symbol msym2 : methodSyms) {
509 Type mt2 = memberType(origin.type, msym2);
510 List<Type> thrown_mt2 = mt2.getThrownTypes();
511 if (toErase) {
512 thrown_mt2 = erasure(thrown_mt2);
513 } else {
514 /* If bestSoFar is generic then all the methods are generic.
515 * The opposite is not true: a non generic method can override
516 * a generic method (raw override) so it's safe to cast mt1 and
517 * mt2 to ForAll.
518 */
519 ForAll fa1 = (ForAll)mt1;
520 ForAll fa2 = (ForAll)mt2;
521 thrown_mt2 = subst(thrown_mt2, fa2.tvars, fa1.tvars);
522 }
523 thrown = (thrown == null) ?
524 thrown_mt2 :
525 chk.intersect(thrown_mt2, thrown);
526 }
528 final List<Type> thrown1 = thrown;
529 return new FunctionDescriptor(bestSoFar) {
530 @Override
531 public Type getType(Type origin) {
532 Type mt = memberType(origin, getSymbol());
533 return createMethodTypeWithThrown(mt, thrown1);
534 }
535 };
536 }
538 boolean isSubtypeInternal(Type s, Type t) {
539 return (s.isPrimitive() && t.isPrimitive()) ?
540 isSameType(t, s) :
541 isSubtype(s, t);
542 }
544 FunctionDescriptorLookupError failure(String msg, Object... args) {
545 return failure(diags.fragment(msg, args));
546 }
548 FunctionDescriptorLookupError failure(JCDiagnostic diag) {
549 return functionDescriptorLookupError.setMessage(diag);
550 }
551 }
553 private DescriptorCache descCache = new DescriptorCache();
555 /**
556 * Find the method descriptor associated to this class symbol - if the
557 * symbol 'origin' is not a functional interface, an exception is thrown.
558 */
559 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError {
560 return descCache.get(origin).getSymbol();
561 }
563 /**
564 * Find the type of the method descriptor associated to this class symbol -
565 * if the symbol 'origin' is not a functional interface, an exception is thrown.
566 */
567 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError {
568 return descCache.get(origin.tsym).getType(origin);
569 }
571 /**
572 * Is given type a functional interface?
573 */
574 public boolean isFunctionalInterface(TypeSymbol tsym) {
575 try {
576 findDescriptorSymbol(tsym);
577 return true;
578 } catch (FunctionDescriptorLookupError ex) {
579 return false;
580 }
581 }
583 public boolean isFunctionalInterface(Type site) {
584 try {
585 findDescriptorType(site);
586 return true;
587 } catch (FunctionDescriptorLookupError ex) {
588 return false;
589 }
590 }
592 public Type removeWildcards(Type site) {
593 Type capturedSite = capture(site);
594 if (capturedSite != site) {
595 Type formalInterface = site.tsym.type;
596 ListBuffer<Type> typeargs = new ListBuffer<>();
597 List<Type> actualTypeargs = site.getTypeArguments();
598 List<Type> capturedTypeargs = capturedSite.getTypeArguments();
599 //simply replace the wildcards with its bound
600 for (Type t : formalInterface.getTypeArguments()) {
601 if (actualTypeargs.head.hasTag(WILDCARD)) {
602 WildcardType wt = (WildcardType)actualTypeargs.head.unannotatedType();
603 Type bound;
604 switch (wt.kind) {
605 case EXTENDS:
606 case UNBOUND:
607 CapturedType capVar = (CapturedType)capturedTypeargs.head.unannotatedType();
608 //use declared bound if it doesn't depend on formal type-args
609 bound = capVar.bound.containsAny(capturedSite.getTypeArguments()) ?
610 wt.type : capVar.bound;
611 break;
612 default:
613 bound = wt.type;
614 }
615 typeargs.append(bound);
616 } else {
617 typeargs.append(actualTypeargs.head);
618 }
619 actualTypeargs = actualTypeargs.tail;
620 capturedTypeargs = capturedTypeargs.tail;
621 }
622 return subst(formalInterface, formalInterface.getTypeArguments(), typeargs.toList());
623 } else {
624 return site;
625 }
626 }
628 /**
629 * Create a symbol for a class that implements a given functional interface
630 * and overrides its functional descriptor. This routine is used for two
631 * main purposes: (i) checking well-formedness of a functional interface;
632 * (ii) perform functional interface bridge calculation.
633 */
634 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, List<Type> targets, long cflags) {
635 if (targets.isEmpty() || !isFunctionalInterface(targets.head)) {
636 return null;
637 }
638 Symbol descSym = findDescriptorSymbol(targets.head.tsym);
639 Type descType = findDescriptorType(targets.head);
640 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass());
641 csym.completer = null;
642 csym.members_field = new Scope(csym);
643 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym);
644 csym.members_field.enter(instDescSym);
645 Type.ClassType ctype = new Type.ClassType(Type.noType, List.<Type>nil(), csym);
646 ctype.supertype_field = syms.objectType;
647 ctype.interfaces_field = targets;
648 csym.type = ctype;
649 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile;
650 return csym;
651 }
653 /**
654 * Find the minimal set of methods that are overridden by the functional
655 * descriptor in 'origin'. All returned methods are assumed to have different
656 * erased signatures.
657 */
658 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) {
659 Assert.check(isFunctionalInterface(origin));
660 Symbol descSym = findDescriptorSymbol(origin);
661 CompoundScope members = membersClosure(origin.type, false);
662 ListBuffer<Symbol> overridden = new ListBuffer<>();
663 outer: for (Symbol m2 : members.getElementsByName(descSym.name, bridgeFilter)) {
664 if (m2 == descSym) continue;
665 else if (descSym.overrides(m2, origin, Types.this, false)) {
666 for (Symbol m3 : overridden) {
667 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) ||
668 (m3.overrides(m2, origin, Types.this, false) &&
669 (pendingBridges((ClassSymbol)origin, m3.enclClass()) ||
670 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) {
671 continue outer;
672 }
673 }
674 overridden.add(m2);
675 }
676 }
677 return overridden.toList();
678 }
679 //where
680 private Filter<Symbol> bridgeFilter = new Filter<Symbol>() {
681 public boolean accepts(Symbol t) {
682 return t.kind == Kinds.MTH &&
683 t.name != names.init &&
684 t.name != names.clinit &&
685 (t.flags() & SYNTHETIC) == 0;
686 }
687 };
688 private boolean pendingBridges(ClassSymbol origin, TypeSymbol s) {
689 //a symbol will be completed from a classfile if (a) symbol has
690 //an associated file object with CLASS kind and (b) the symbol has
691 //not been entered
692 if (origin.classfile != null &&
693 origin.classfile.getKind() == JavaFileObject.Kind.CLASS &&
694 enter.getEnv(origin) == null) {
695 return false;
696 }
697 if (origin == s) {
698 return true;
699 }
700 for (Type t : interfaces(origin.type)) {
701 if (pendingBridges((ClassSymbol)t.tsym, s)) {
702 return true;
703 }
704 }
705 return false;
706 }
707 // </editor-fold>
709 /**
710 * Scope filter used to skip methods that should be ignored (such as methods
711 * overridden by j.l.Object) during function interface conversion interface check
712 */
713 class DescriptorFilter implements Filter<Symbol> {
715 TypeSymbol origin;
717 DescriptorFilter(TypeSymbol origin) {
718 this.origin = origin;
719 }
721 @Override
722 public boolean accepts(Symbol sym) {
723 return sym.kind == Kinds.MTH &&
724 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT &&
725 !overridesObjectMethod(origin, sym) &&
726 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0;
727 }
728 };
730 // <editor-fold defaultstate="collapsed" desc="isSubtype">
731 /**
732 * Is t an unchecked subtype of s?
733 */
734 public boolean isSubtypeUnchecked(Type t, Type s) {
735 return isSubtypeUnchecked(t, s, noWarnings);
736 }
737 /**
738 * Is t an unchecked subtype of s?
739 */
740 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) {
741 boolean result = isSubtypeUncheckedInternal(t, s, warn);
742 if (result) {
743 checkUnsafeVarargsConversion(t, s, warn);
744 }
745 return result;
746 }
747 //where
748 private boolean isSubtypeUncheckedInternal(Type t, Type s, Warner warn) {
749 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) {
750 t = t.unannotatedType();
751 s = s.unannotatedType();
752 if (((ArrayType)t).elemtype.isPrimitive()) {
753 return isSameType(elemtype(t), elemtype(s));
754 } else {
755 return isSubtypeUnchecked(elemtype(t), elemtype(s), warn);
756 }
757 } else if (isSubtype(t, s)) {
758 return true;
759 } else if (t.hasTag(TYPEVAR)) {
760 return isSubtypeUnchecked(t.getUpperBound(), s, warn);
761 } else if (!s.isRaw()) {
762 Type t2 = asSuper(t, s.tsym);
763 if (t2 != null && t2.isRaw()) {
764 if (isReifiable(s)) {
765 warn.silentWarn(LintCategory.UNCHECKED);
766 } else {
767 warn.warn(LintCategory.UNCHECKED);
768 }
769 return true;
770 }
771 }
772 return false;
773 }
775 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) {
776 if (!t.hasTag(ARRAY) || isReifiable(t)) {
777 return;
778 }
779 t = t.unannotatedType();
780 s = s.unannotatedType();
781 ArrayType from = (ArrayType)t;
782 boolean shouldWarn = false;
783 switch (s.getTag()) {
784 case ARRAY:
785 ArrayType to = (ArrayType)s;
786 shouldWarn = from.isVarargs() &&
787 !to.isVarargs() &&
788 !isReifiable(from);
789 break;
790 case CLASS:
791 shouldWarn = from.isVarargs();
792 break;
793 }
794 if (shouldWarn) {
795 warn.warn(LintCategory.VARARGS);
796 }
797 }
799 /**
800 * Is t a subtype of s?<br>
801 * (not defined for Method and ForAll types)
802 */
803 final public boolean isSubtype(Type t, Type s) {
804 return isSubtype(t, s, true);
805 }
806 final public boolean isSubtypeNoCapture(Type t, Type s) {
807 return isSubtype(t, s, false);
808 }
809 public boolean isSubtype(Type t, Type s, boolean capture) {
810 if (t == s)
811 return true;
813 t = t.unannotatedType();
814 s = s.unannotatedType();
816 if (t == s)
817 return true;
819 if (s.isPartial())
820 return isSuperType(s, t);
822 if (s.isCompound()) {
823 for (Type s2 : interfaces(s).prepend(supertype(s))) {
824 if (!isSubtype(t, s2, capture))
825 return false;
826 }
827 return true;
828 }
830 Type lower = lowerBound(s);
831 if (s != lower)
832 return isSubtype(capture ? capture(t) : t, lower, false);
834 return isSubtype.visit(capture ? capture(t) : t, s);
835 }
836 // where
837 private TypeRelation isSubtype = new TypeRelation()
838 {
839 @Override
840 public Boolean visitType(Type t, Type s) {
841 switch (t.getTag()) {
842 case BYTE:
843 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag()));
844 case CHAR:
845 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag()));
846 case SHORT: case INT: case LONG:
847 case FLOAT: case DOUBLE:
848 return t.getTag().isSubRangeOf(s.getTag());
849 case BOOLEAN: case VOID:
850 return t.hasTag(s.getTag());
851 case TYPEVAR:
852 return isSubtypeNoCapture(t.getUpperBound(), s);
853 case BOT:
854 return
855 s.hasTag(BOT) || s.hasTag(CLASS) ||
856 s.hasTag(ARRAY) || s.hasTag(TYPEVAR);
857 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495)
858 case NONE:
859 return false;
860 default:
861 throw new AssertionError("isSubtype " + t.getTag());
862 }
863 }
865 private Set<TypePair> cache = new HashSet<TypePair>();
867 private boolean containsTypeRecursive(Type t, Type s) {
868 TypePair pair = new TypePair(t, s);
869 if (cache.add(pair)) {
870 try {
871 return containsType(t.getTypeArguments(),
872 s.getTypeArguments());
873 } finally {
874 cache.remove(pair);
875 }
876 } else {
877 return containsType(t.getTypeArguments(),
878 rewriteSupers(s).getTypeArguments());
879 }
880 }
882 private Type rewriteSupers(Type t) {
883 if (!t.isParameterized())
884 return t;
885 ListBuffer<Type> from = new ListBuffer<>();
886 ListBuffer<Type> to = new ListBuffer<>();
887 adaptSelf(t, from, to);
888 if (from.isEmpty())
889 return t;
890 ListBuffer<Type> rewrite = new ListBuffer<>();
891 boolean changed = false;
892 for (Type orig : to.toList()) {
893 Type s = rewriteSupers(orig);
894 if (s.isSuperBound() && !s.isExtendsBound()) {
895 s = new WildcardType(syms.objectType,
896 BoundKind.UNBOUND,
897 syms.boundClass);
898 changed = true;
899 } else if (s != orig) {
900 s = new WildcardType(upperBound(s),
901 BoundKind.EXTENDS,
902 syms.boundClass);
903 changed = true;
904 }
905 rewrite.append(s);
906 }
907 if (changed)
908 return subst(t.tsym.type, from.toList(), rewrite.toList());
909 else
910 return t;
911 }
913 @Override
914 public Boolean visitClassType(ClassType t, Type s) {
915 Type sup = asSuper(t, s.tsym);
916 return sup != null
917 && sup.tsym == s.tsym
918 // You're not allowed to write
919 // Vector<Object> vec = new Vector<String>();
920 // But with wildcards you can write
921 // Vector<? extends Object> vec = new Vector<String>();
922 // which means that subtype checking must be done
923 // here instead of same-type checking (via containsType).
924 && (!s.isParameterized() || containsTypeRecursive(s, sup))
925 && isSubtypeNoCapture(sup.getEnclosingType(),
926 s.getEnclosingType());
927 }
929 @Override
930 public Boolean visitArrayType(ArrayType t, Type s) {
931 if (s.hasTag(ARRAY)) {
932 if (t.elemtype.isPrimitive())
933 return isSameType(t.elemtype, elemtype(s));
934 else
935 return isSubtypeNoCapture(t.elemtype, elemtype(s));
936 }
938 if (s.hasTag(CLASS)) {
939 Name sname = s.tsym.getQualifiedName();
940 return sname == names.java_lang_Object
941 || sname == names.java_lang_Cloneable
942 || sname == names.java_io_Serializable;
943 }
945 return false;
946 }
948 @Override
949 public Boolean visitUndetVar(UndetVar t, Type s) {
950 //todo: test against origin needed? or replace with substitution?
951 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
952 return true;
953 } else if (s.hasTag(BOT)) {
954 //if 's' is 'null' there's no instantiated type U for which
955 //U <: s (but 'null' itself, which is not a valid type)
956 return false;
957 }
959 t.addBound(InferenceBound.UPPER, s, Types.this);
960 return true;
961 }
963 @Override
964 public Boolean visitErrorType(ErrorType t, Type s) {
965 return true;
966 }
967 };
969 /**
970 * Is t a subtype of every type in given list `ts'?<br>
971 * (not defined for Method and ForAll types)<br>
972 * Allows unchecked conversions.
973 */
974 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) {
975 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
976 if (!isSubtypeUnchecked(t, l.head, warn))
977 return false;
978 return true;
979 }
981 /**
982 * Are corresponding elements of ts subtypes of ss? If lists are
983 * of different length, return false.
984 */
985 public boolean isSubtypes(List<Type> ts, List<Type> ss) {
986 while (ts.tail != null && ss.tail != null
987 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
988 isSubtype(ts.head, ss.head)) {
989 ts = ts.tail;
990 ss = ss.tail;
991 }
992 return ts.tail == null && ss.tail == null;
993 /*inlined: ts.isEmpty() && ss.isEmpty();*/
994 }
996 /**
997 * Are corresponding elements of ts subtypes of ss, allowing
998 * unchecked conversions? If lists are of different length,
999 * return false.
1000 **/
1001 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) {
1002 while (ts.tail != null && ss.tail != null
1003 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1004 isSubtypeUnchecked(ts.head, ss.head, warn)) {
1005 ts = ts.tail;
1006 ss = ss.tail;
1007 }
1008 return ts.tail == null && ss.tail == null;
1009 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1010 }
1011 // </editor-fold>
1013 // <editor-fold defaultstate="collapsed" desc="isSuperType">
1014 /**
1015 * Is t a supertype of s?
1016 */
1017 public boolean isSuperType(Type t, Type s) {
1018 switch (t.getTag()) {
1019 case ERROR:
1020 return true;
1021 case UNDETVAR: {
1022 UndetVar undet = (UndetVar)t;
1023 if (t == s ||
1024 undet.qtype == s ||
1025 s.hasTag(ERROR) ||
1026 s.hasTag(BOT)) {
1027 return true;
1028 }
1029 undet.addBound(InferenceBound.LOWER, s, this);
1030 return true;
1031 }
1032 default:
1033 return isSubtype(s, t);
1034 }
1035 }
1036 // </editor-fold>
1038 // <editor-fold defaultstate="collapsed" desc="isSameType">
1039 /**
1040 * Are corresponding elements of the lists the same type? If
1041 * lists are of different length, return false.
1042 */
1043 public boolean isSameTypes(List<Type> ts, List<Type> ss) {
1044 return isSameTypes(ts, ss, false);
1045 }
1046 public boolean isSameTypes(List<Type> ts, List<Type> ss, boolean strict) {
1047 while (ts.tail != null && ss.tail != null
1048 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1049 isSameType(ts.head, ss.head, strict)) {
1050 ts = ts.tail;
1051 ss = ss.tail;
1052 }
1053 return ts.tail == null && ss.tail == null;
1054 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1055 }
1057 /**
1058 * A polymorphic signature method (JLS SE 7, 8.4.1) is a method that
1059 * (i) is declared in the java.lang.invoke.MethodHandle class, (ii) takes
1060 * a single variable arity parameter (iii) whose declared type is Object[],
1061 * (iv) has a return type of Object and (v) is native.
1062 */
1063 public boolean isSignaturePolymorphic(MethodSymbol msym) {
1064 List<Type> argtypes = msym.type.getParameterTypes();
1065 return (msym.flags_field & NATIVE) != 0 &&
1066 msym.owner == syms.methodHandleType.tsym &&
1067 argtypes.tail.tail == null &&
1068 argtypes.head.hasTag(TypeTag.ARRAY) &&
1069 msym.type.getReturnType().tsym == syms.objectType.tsym &&
1070 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym;
1071 }
1073 /**
1074 * Is t the same type as s?
1075 */
1076 public boolean isSameType(Type t, Type s) {
1077 return isSameType(t, s, false);
1078 }
1079 public boolean isSameType(Type t, Type s, boolean strict) {
1080 return strict ?
1081 isSameTypeStrict.visit(t, s) :
1082 isSameTypeLoose.visit(t, s);
1083 }
1084 public boolean isSameAnnotatedType(Type t, Type s) {
1085 return isSameAnnotatedType.visit(t, s);
1086 }
1087 // where
1088 abstract class SameTypeVisitor extends TypeRelation {
1090 public Boolean visitType(Type t, Type s) {
1091 if (t == s)
1092 return true;
1094 if (s.isPartial())
1095 return visit(s, t);
1097 switch (t.getTag()) {
1098 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1099 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE:
1100 return t.hasTag(s.getTag());
1101 case TYPEVAR: {
1102 if (s.hasTag(TYPEVAR)) {
1103 //type-substitution does not preserve type-var types
1104 //check that type var symbols and bounds are indeed the same
1105 return sameTypeVars((TypeVar)t.unannotatedType(), (TypeVar)s.unannotatedType());
1106 }
1107 else {
1108 //special case for s == ? super X, where upper(s) = u
1109 //check that u == t, where u has been set by Type.withTypeVar
1110 return s.isSuperBound() &&
1111 !s.isExtendsBound() &&
1112 visit(t, upperBound(s));
1113 }
1114 }
1115 default:
1116 throw new AssertionError("isSameType " + t.getTag());
1117 }
1118 }
1120 abstract boolean sameTypeVars(TypeVar tv1, TypeVar tv2);
1122 @Override
1123 public Boolean visitWildcardType(WildcardType t, Type s) {
1124 if (s.isPartial())
1125 return visit(s, t);
1126 else
1127 return false;
1128 }
1130 @Override
1131 public Boolean visitClassType(ClassType t, Type s) {
1132 if (t == s)
1133 return true;
1135 if (s.isPartial())
1136 return visit(s, t);
1138 if (s.isSuperBound() && !s.isExtendsBound())
1139 return visit(t, upperBound(s)) && visit(t, lowerBound(s));
1141 if (t.isCompound() && s.isCompound()) {
1142 if (!visit(supertype(t), supertype(s)))
1143 return false;
1145 HashSet<UniqueType> set = new HashSet<UniqueType>();
1146 for (Type x : interfaces(t))
1147 set.add(new UniqueType(x.unannotatedType(), Types.this));
1148 for (Type x : interfaces(s)) {
1149 if (!set.remove(new UniqueType(x.unannotatedType(), Types.this)))
1150 return false;
1151 }
1152 return (set.isEmpty());
1153 }
1154 return t.tsym == s.tsym
1155 && visit(t.getEnclosingType(), s.getEnclosingType())
1156 && containsTypes(t.getTypeArguments(), s.getTypeArguments());
1157 }
1159 abstract protected boolean containsTypes(List<Type> ts1, List<Type> ts2);
1161 @Override
1162 public Boolean visitArrayType(ArrayType t, Type s) {
1163 if (t == s)
1164 return true;
1166 if (s.isPartial())
1167 return visit(s, t);
1169 return s.hasTag(ARRAY)
1170 && containsTypeEquivalent(t.elemtype, elemtype(s));
1171 }
1173 @Override
1174 public Boolean visitMethodType(MethodType t, Type s) {
1175 // isSameType for methods does not take thrown
1176 // exceptions into account!
1177 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType());
1178 }
1180 @Override
1181 public Boolean visitPackageType(PackageType t, Type s) {
1182 return t == s;
1183 }
1185 @Override
1186 public Boolean visitForAll(ForAll t, Type s) {
1187 if (!s.hasTag(FORALL)) {
1188 return false;
1189 }
1191 ForAll forAll = (ForAll)s;
1192 return hasSameBounds(t, forAll)
1193 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
1194 }
1196 @Override
1197 public Boolean visitUndetVar(UndetVar t, Type s) {
1198 if (s.hasTag(WILDCARD)) {
1199 // FIXME, this might be leftovers from before capture conversion
1200 return false;
1201 }
1203 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1204 return true;
1205 }
1207 t.addBound(InferenceBound.EQ, s, Types.this);
1209 return true;
1210 }
1212 @Override
1213 public Boolean visitErrorType(ErrorType t, Type s) {
1214 return true;
1215 }
1216 }
1218 /**
1219 * Standard type-equality relation - type variables are considered
1220 * equals if they share the same type symbol.
1221 */
1222 TypeRelation isSameTypeLoose = new LooseSameTypeVisitor();
1224 private class LooseSameTypeVisitor extends SameTypeVisitor {
1225 @Override
1226 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) {
1227 return tv1.tsym == tv2.tsym && visit(tv1.getUpperBound(), tv2.getUpperBound());
1228 }
1229 @Override
1230 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) {
1231 return containsTypeEquivalent(ts1, ts2);
1232 }
1233 };
1235 /**
1236 * Strict type-equality relation - type variables are considered
1237 * equals if they share the same object identity.
1238 */
1239 TypeRelation isSameTypeStrict = new SameTypeVisitor() {
1240 @Override
1241 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) {
1242 return tv1 == tv2;
1243 }
1244 @Override
1245 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) {
1246 return isSameTypes(ts1, ts2, true);
1247 }
1249 @Override
1250 public Boolean visitWildcardType(WildcardType t, Type s) {
1251 if (!s.hasTag(WILDCARD)) {
1252 return false;
1253 } else {
1254 WildcardType t2 = (WildcardType)s.unannotatedType();
1255 return t.kind == t2.kind &&
1256 isSameType(t.type, t2.type, true);
1257 }
1258 }
1259 };
1261 /**
1262 * A version of LooseSameTypeVisitor that takes AnnotatedTypes
1263 * into account.
1264 */
1265 TypeRelation isSameAnnotatedType = new LooseSameTypeVisitor() {
1266 @Override
1267 public Boolean visitAnnotatedType(AnnotatedType t, Type s) {
1268 if (!s.isAnnotated())
1269 return false;
1270 if (!t.getAnnotationMirrors().containsAll(s.getAnnotationMirrors()))
1271 return false;
1272 if (!s.getAnnotationMirrors().containsAll(t.getAnnotationMirrors()))
1273 return false;
1274 return visit(t.unannotatedType(), s);
1275 }
1276 };
1277 // </editor-fold>
1279 // <editor-fold defaultstate="collapsed" desc="Contains Type">
1280 public boolean containedBy(Type t, Type s) {
1281 switch (t.getTag()) {
1282 case UNDETVAR:
1283 if (s.hasTag(WILDCARD)) {
1284 UndetVar undetvar = (UndetVar)t;
1285 WildcardType wt = (WildcardType)s.unannotatedType();
1286 switch(wt.kind) {
1287 case UNBOUND: //similar to ? extends Object
1288 case EXTENDS: {
1289 Type bound = upperBound(s);
1290 undetvar.addBound(InferenceBound.UPPER, bound, this);
1291 break;
1292 }
1293 case SUPER: {
1294 Type bound = lowerBound(s);
1295 undetvar.addBound(InferenceBound.LOWER, bound, this);
1296 break;
1297 }
1298 }
1299 return true;
1300 } else {
1301 return isSameType(t, s);
1302 }
1303 case ERROR:
1304 return true;
1305 default:
1306 return containsType(s, t);
1307 }
1308 }
1310 boolean containsType(List<Type> ts, List<Type> ss) {
1311 while (ts.nonEmpty() && ss.nonEmpty()
1312 && containsType(ts.head, ss.head)) {
1313 ts = ts.tail;
1314 ss = ss.tail;
1315 }
1316 return ts.isEmpty() && ss.isEmpty();
1317 }
1319 /**
1320 * Check if t contains s.
1321 *
1322 * <p>T contains S if:
1323 *
1324 * <p>{@code L(T) <: L(S) && U(S) <: U(T)}
1325 *
1326 * <p>This relation is only used by ClassType.isSubtype(), that
1327 * is,
1328 *
1329 * <p>{@code C<S> <: C<T> if T contains S.}
1330 *
1331 * <p>Because of F-bounds, this relation can lead to infinite
1332 * recursion. Thus we must somehow break that recursion. Notice
1333 * that containsType() is only called from ClassType.isSubtype().
1334 * Since the arguments have already been checked against their
1335 * bounds, we know:
1336 *
1337 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)}
1338 *
1339 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)}
1340 *
1341 * @param t a type
1342 * @param s a type
1343 */
1344 public boolean containsType(Type t, Type s) {
1345 return containsType.visit(t, s);
1346 }
1347 // where
1348 private TypeRelation containsType = new TypeRelation() {
1350 private Type U(Type t) {
1351 while (t.hasTag(WILDCARD)) {
1352 WildcardType w = (WildcardType)t.unannotatedType();
1353 if (w.isSuperBound())
1354 return w.bound == null ? syms.objectType : w.bound.bound;
1355 else
1356 t = w.type;
1357 }
1358 return t;
1359 }
1361 private Type L(Type t) {
1362 while (t.hasTag(WILDCARD)) {
1363 WildcardType w = (WildcardType)t.unannotatedType();
1364 if (w.isExtendsBound())
1365 return syms.botType;
1366 else
1367 t = w.type;
1368 }
1369 return t;
1370 }
1372 public Boolean visitType(Type t, Type s) {
1373 if (s.isPartial())
1374 return containedBy(s, t);
1375 else
1376 return isSameType(t, s);
1377 }
1379 // void debugContainsType(WildcardType t, Type s) {
1380 // System.err.println();
1381 // System.err.format(" does %s contain %s?%n", t, s);
1382 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n",
1383 // upperBound(s), s, t, U(t),
1384 // t.isSuperBound()
1385 // || isSubtypeNoCapture(upperBound(s), U(t)));
1386 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n",
1387 // L(t), t, s, lowerBound(s),
1388 // t.isExtendsBound()
1389 // || isSubtypeNoCapture(L(t), lowerBound(s)));
1390 // System.err.println();
1391 // }
1393 @Override
1394 public Boolean visitWildcardType(WildcardType t, Type s) {
1395 if (s.isPartial())
1396 return containedBy(s, t);
1397 else {
1398 // debugContainsType(t, s);
1399 return isSameWildcard(t, s)
1400 || isCaptureOf(s, t)
1401 || ((t.isExtendsBound() || isSubtypeNoCapture(L(t), lowerBound(s))) &&
1402 (t.isSuperBound() || isSubtypeNoCapture(upperBound(s), U(t))));
1403 }
1404 }
1406 @Override
1407 public Boolean visitUndetVar(UndetVar t, Type s) {
1408 if (!s.hasTag(WILDCARD)) {
1409 return isSameType(t, s);
1410 } else {
1411 return false;
1412 }
1413 }
1415 @Override
1416 public Boolean visitErrorType(ErrorType t, Type s) {
1417 return true;
1418 }
1419 };
1421 public boolean isCaptureOf(Type s, WildcardType t) {
1422 if (!s.hasTag(TYPEVAR) || !((TypeVar)s.unannotatedType()).isCaptured())
1423 return false;
1424 return isSameWildcard(t, ((CapturedType)s.unannotatedType()).wildcard);
1425 }
1427 public boolean isSameWildcard(WildcardType t, Type s) {
1428 if (!s.hasTag(WILDCARD))
1429 return false;
1430 WildcardType w = (WildcardType)s.unannotatedType();
1431 return w.kind == t.kind && w.type == t.type;
1432 }
1434 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) {
1435 while (ts.nonEmpty() && ss.nonEmpty()
1436 && containsTypeEquivalent(ts.head, ss.head)) {
1437 ts = ts.tail;
1438 ss = ss.tail;
1439 }
1440 return ts.isEmpty() && ss.isEmpty();
1441 }
1442 // </editor-fold>
1444 /**
1445 * Can t and s be compared for equality? Any primitive ==
1446 * primitive or primitive == object comparisons here are an error.
1447 * Unboxing and correct primitive == primitive comparisons are
1448 * already dealt with in Attr.visitBinary.
1449 *
1450 */
1451 public boolean isEqualityComparable(Type s, Type t, Warner warn) {
1452 if (t.isNumeric() && s.isNumeric())
1453 return true;
1455 boolean tPrimitive = t.isPrimitive();
1456 boolean sPrimitive = s.isPrimitive();
1457 if (!tPrimitive && !sPrimitive) {
1458 return isCastable(s, t, warn) || isCastable(t, s, warn);
1459 } else {
1460 return false;
1461 }
1462 }
1464 // <editor-fold defaultstate="collapsed" desc="isCastable">
1465 public boolean isCastable(Type t, Type s) {
1466 return isCastable(t, s, noWarnings);
1467 }
1469 /**
1470 * Is t is castable to s?<br>
1471 * s is assumed to be an erased type.<br>
1472 * (not defined for Method and ForAll types).
1473 */
1474 public boolean isCastable(Type t, Type s, Warner warn) {
1475 if (t == s)
1476 return true;
1478 if (t.isPrimitive() != s.isPrimitive())
1479 return allowBoxing && (
1480 isConvertible(t, s, warn)
1481 || (allowObjectToPrimitiveCast &&
1482 s.isPrimitive() &&
1483 isSubtype(boxedClass(s).type, t)));
1484 if (warn != warnStack.head) {
1485 try {
1486 warnStack = warnStack.prepend(warn);
1487 checkUnsafeVarargsConversion(t, s, warn);
1488 return isCastable.visit(t,s);
1489 } finally {
1490 warnStack = warnStack.tail;
1491 }
1492 } else {
1493 return isCastable.visit(t,s);
1494 }
1495 }
1496 // where
1497 private TypeRelation isCastable = new TypeRelation() {
1499 public Boolean visitType(Type t, Type s) {
1500 if (s.hasTag(ERROR))
1501 return true;
1503 switch (t.getTag()) {
1504 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1505 case DOUBLE:
1506 return s.isNumeric();
1507 case BOOLEAN:
1508 return s.hasTag(BOOLEAN);
1509 case VOID:
1510 return false;
1511 case BOT:
1512 return isSubtype(t, s);
1513 default:
1514 throw new AssertionError();
1515 }
1516 }
1518 @Override
1519 public Boolean visitWildcardType(WildcardType t, Type s) {
1520 return isCastable(upperBound(t), s, warnStack.head);
1521 }
1523 @Override
1524 public Boolean visitClassType(ClassType t, Type s) {
1525 if (s.hasTag(ERROR) || s.hasTag(BOT))
1526 return true;
1528 if (s.hasTag(TYPEVAR)) {
1529 if (isCastable(t, s.getUpperBound(), noWarnings)) {
1530 warnStack.head.warn(LintCategory.UNCHECKED);
1531 return true;
1532 } else {
1533 return false;
1534 }
1535 }
1537 if (t.isCompound() || s.isCompound()) {
1538 return !t.isCompound() ?
1539 visitIntersectionType((IntersectionClassType)s.unannotatedType(), t, true) :
1540 visitIntersectionType((IntersectionClassType)t.unannotatedType(), s, false);
1541 }
1543 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) {
1544 boolean upcast;
1545 if ((upcast = isSubtype(erasure(t), erasure(s)))
1546 || isSubtype(erasure(s), erasure(t))) {
1547 if (!upcast && s.hasTag(ARRAY)) {
1548 if (!isReifiable(s))
1549 warnStack.head.warn(LintCategory.UNCHECKED);
1550 return true;
1551 } else if (s.isRaw()) {
1552 return true;
1553 } else if (t.isRaw()) {
1554 if (!isUnbounded(s))
1555 warnStack.head.warn(LintCategory.UNCHECKED);
1556 return true;
1557 }
1558 // Assume |a| <: |b|
1559 final Type a = upcast ? t : s;
1560 final Type b = upcast ? s : t;
1561 final boolean HIGH = true;
1562 final boolean LOW = false;
1563 final boolean DONT_REWRITE_TYPEVARS = false;
1564 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS);
1565 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS);
1566 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS);
1567 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS);
1568 Type lowSub = asSub(bLow, aLow.tsym);
1569 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1570 if (highSub == null) {
1571 final boolean REWRITE_TYPEVARS = true;
1572 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS);
1573 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS);
1574 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS);
1575 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS);
1576 lowSub = asSub(bLow, aLow.tsym);
1577 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1578 }
1579 if (highSub != null) {
1580 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) {
1581 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym);
1582 }
1583 if (!disjointTypes(aHigh.allparams(), highSub.allparams())
1584 && !disjointTypes(aHigh.allparams(), lowSub.allparams())
1585 && !disjointTypes(aLow.allparams(), highSub.allparams())
1586 && !disjointTypes(aLow.allparams(), lowSub.allparams())) {
1587 if (upcast ? giveWarning(a, b) :
1588 giveWarning(b, a))
1589 warnStack.head.warn(LintCategory.UNCHECKED);
1590 return true;
1591 }
1592 }
1593 if (isReifiable(s))
1594 return isSubtypeUnchecked(a, b);
1595 else
1596 return isSubtypeUnchecked(a, b, warnStack.head);
1597 }
1599 // Sidecast
1600 if (s.hasTag(CLASS)) {
1601 if ((s.tsym.flags() & INTERFACE) != 0) {
1602 return ((t.tsym.flags() & FINAL) == 0)
1603 ? sideCast(t, s, warnStack.head)
1604 : sideCastFinal(t, s, warnStack.head);
1605 } else if ((t.tsym.flags() & INTERFACE) != 0) {
1606 return ((s.tsym.flags() & FINAL) == 0)
1607 ? sideCast(t, s, warnStack.head)
1608 : sideCastFinal(t, s, warnStack.head);
1609 } else {
1610 // unrelated class types
1611 return false;
1612 }
1613 }
1614 }
1615 return false;
1616 }
1618 boolean visitIntersectionType(IntersectionClassType ict, Type s, boolean reverse) {
1619 Warner warn = noWarnings;
1620 for (Type c : ict.getComponents()) {
1621 warn.clear();
1622 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn))
1623 return false;
1624 }
1625 if (warn.hasLint(LintCategory.UNCHECKED))
1626 warnStack.head.warn(LintCategory.UNCHECKED);
1627 return true;
1628 }
1630 @Override
1631 public Boolean visitArrayType(ArrayType t, Type s) {
1632 switch (s.getTag()) {
1633 case ERROR:
1634 case BOT:
1635 return true;
1636 case TYPEVAR:
1637 if (isCastable(s, t, noWarnings)) {
1638 warnStack.head.warn(LintCategory.UNCHECKED);
1639 return true;
1640 } else {
1641 return false;
1642 }
1643 case CLASS:
1644 return isSubtype(t, s);
1645 case ARRAY:
1646 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) {
1647 return elemtype(t).hasTag(elemtype(s).getTag());
1648 } else {
1649 return visit(elemtype(t), elemtype(s));
1650 }
1651 default:
1652 return false;
1653 }
1654 }
1656 @Override
1657 public Boolean visitTypeVar(TypeVar t, Type s) {
1658 switch (s.getTag()) {
1659 case ERROR:
1660 case BOT:
1661 return true;
1662 case TYPEVAR:
1663 if (isSubtype(t, s)) {
1664 return true;
1665 } else if (isCastable(t.bound, s, noWarnings)) {
1666 warnStack.head.warn(LintCategory.UNCHECKED);
1667 return true;
1668 } else {
1669 return false;
1670 }
1671 default:
1672 return isCastable(t.bound, s, warnStack.head);
1673 }
1674 }
1676 @Override
1677 public Boolean visitErrorType(ErrorType t, Type s) {
1678 return true;
1679 }
1680 };
1681 // </editor-fold>
1683 // <editor-fold defaultstate="collapsed" desc="disjointTypes">
1684 public boolean disjointTypes(List<Type> ts, List<Type> ss) {
1685 while (ts.tail != null && ss.tail != null) {
1686 if (disjointType(ts.head, ss.head)) return true;
1687 ts = ts.tail;
1688 ss = ss.tail;
1689 }
1690 return false;
1691 }
1693 /**
1694 * Two types or wildcards are considered disjoint if it can be
1695 * proven that no type can be contained in both. It is
1696 * conservative in that it is allowed to say that two types are
1697 * not disjoint, even though they actually are.
1698 *
1699 * The type {@code C<X>} is castable to {@code C<Y>} exactly if
1700 * {@code X} and {@code Y} are not disjoint.
1701 */
1702 public boolean disjointType(Type t, Type s) {
1703 return disjointType.visit(t, s);
1704 }
1705 // where
1706 private TypeRelation disjointType = new TypeRelation() {
1708 private Set<TypePair> cache = new HashSet<TypePair>();
1710 @Override
1711 public Boolean visitType(Type t, Type s) {
1712 if (s.hasTag(WILDCARD))
1713 return visit(s, t);
1714 else
1715 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t);
1716 }
1718 private boolean isCastableRecursive(Type t, Type s) {
1719 TypePair pair = new TypePair(t, s);
1720 if (cache.add(pair)) {
1721 try {
1722 return Types.this.isCastable(t, s);
1723 } finally {
1724 cache.remove(pair);
1725 }
1726 } else {
1727 return true;
1728 }
1729 }
1731 private boolean notSoftSubtypeRecursive(Type t, Type s) {
1732 TypePair pair = new TypePair(t, s);
1733 if (cache.add(pair)) {
1734 try {
1735 return Types.this.notSoftSubtype(t, s);
1736 } finally {
1737 cache.remove(pair);
1738 }
1739 } else {
1740 return false;
1741 }
1742 }
1744 @Override
1745 public Boolean visitWildcardType(WildcardType t, Type s) {
1746 if (t.isUnbound())
1747 return false;
1749 if (!s.hasTag(WILDCARD)) {
1750 if (t.isExtendsBound())
1751 return notSoftSubtypeRecursive(s, t.type);
1752 else
1753 return notSoftSubtypeRecursive(t.type, s);
1754 }
1756 if (s.isUnbound())
1757 return false;
1759 if (t.isExtendsBound()) {
1760 if (s.isExtendsBound())
1761 return !isCastableRecursive(t.type, upperBound(s));
1762 else if (s.isSuperBound())
1763 return notSoftSubtypeRecursive(lowerBound(s), t.type);
1764 } else if (t.isSuperBound()) {
1765 if (s.isExtendsBound())
1766 return notSoftSubtypeRecursive(t.type, upperBound(s));
1767 }
1768 return false;
1769 }
1770 };
1771 // </editor-fold>
1773 // <editor-fold defaultstate="collapsed" desc="lowerBoundArgtypes">
1774 /**
1775 * Returns the lower bounds of the formals of a method.
1776 */
1777 public List<Type> lowerBoundArgtypes(Type t) {
1778 return lowerBounds(t.getParameterTypes());
1779 }
1780 public List<Type> lowerBounds(List<Type> ts) {
1781 return map(ts, lowerBoundMapping);
1782 }
1783 private final Mapping lowerBoundMapping = new Mapping("lowerBound") {
1784 public Type apply(Type t) {
1785 return lowerBound(t);
1786 }
1787 };
1788 // </editor-fold>
1790 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype">
1791 /**
1792 * This relation answers the question: is impossible that
1793 * something of type `t' can be a subtype of `s'? This is
1794 * different from the question "is `t' not a subtype of `s'?"
1795 * when type variables are involved: Integer is not a subtype of T
1796 * where {@code <T extends Number>} but it is not true that Integer cannot
1797 * possibly be a subtype of T.
1798 */
1799 public boolean notSoftSubtype(Type t, Type s) {
1800 if (t == s) return false;
1801 if (t.hasTag(TYPEVAR)) {
1802 TypeVar tv = (TypeVar) t;
1803 return !isCastable(tv.bound,
1804 relaxBound(s),
1805 noWarnings);
1806 }
1807 if (!s.hasTag(WILDCARD))
1808 s = upperBound(s);
1810 return !isSubtype(t, relaxBound(s));
1811 }
1813 private Type relaxBound(Type t) {
1814 if (t.hasTag(TYPEVAR)) {
1815 while (t.hasTag(TYPEVAR))
1816 t = t.getUpperBound();
1817 t = rewriteQuantifiers(t, true, true);
1818 }
1819 return t;
1820 }
1821 // </editor-fold>
1823 // <editor-fold defaultstate="collapsed" desc="isReifiable">
1824 public boolean isReifiable(Type t) {
1825 return isReifiable.visit(t);
1826 }
1827 // where
1828 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() {
1830 public Boolean visitType(Type t, Void ignored) {
1831 return true;
1832 }
1834 @Override
1835 public Boolean visitClassType(ClassType t, Void ignored) {
1836 if (t.isCompound())
1837 return false;
1838 else {
1839 if (!t.isParameterized())
1840 return true;
1842 for (Type param : t.allparams()) {
1843 if (!param.isUnbound())
1844 return false;
1845 }
1846 return true;
1847 }
1848 }
1850 @Override
1851 public Boolean visitArrayType(ArrayType t, Void ignored) {
1852 return visit(t.elemtype);
1853 }
1855 @Override
1856 public Boolean visitTypeVar(TypeVar t, Void ignored) {
1857 return false;
1858 }
1859 };
1860 // </editor-fold>
1862 // <editor-fold defaultstate="collapsed" desc="Array Utils">
1863 public boolean isArray(Type t) {
1864 while (t.hasTag(WILDCARD))
1865 t = upperBound(t);
1866 return t.hasTag(ARRAY);
1867 }
1869 /**
1870 * The element type of an array.
1871 */
1872 public Type elemtype(Type t) {
1873 switch (t.getTag()) {
1874 case WILDCARD:
1875 return elemtype(upperBound(t));
1876 case ARRAY:
1877 t = t.unannotatedType();
1878 return ((ArrayType)t).elemtype;
1879 case FORALL:
1880 return elemtype(((ForAll)t).qtype);
1881 case ERROR:
1882 return t;
1883 default:
1884 return null;
1885 }
1886 }
1888 public Type elemtypeOrType(Type t) {
1889 Type elemtype = elemtype(t);
1890 return elemtype != null ?
1891 elemtype :
1892 t;
1893 }
1895 /**
1896 * Mapping to take element type of an arraytype
1897 */
1898 private Mapping elemTypeFun = new Mapping ("elemTypeFun") {
1899 public Type apply(Type t) { return elemtype(t); }
1900 };
1902 /**
1903 * The number of dimensions of an array type.
1904 */
1905 public int dimensions(Type t) {
1906 int result = 0;
1907 while (t.hasTag(ARRAY)) {
1908 result++;
1909 t = elemtype(t);
1910 }
1911 return result;
1912 }
1914 /**
1915 * Returns an ArrayType with the component type t
1916 *
1917 * @param t The component type of the ArrayType
1918 * @return the ArrayType for the given component
1919 */
1920 public ArrayType makeArrayType(Type t) {
1921 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) {
1922 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString());
1923 }
1924 return new ArrayType(t, syms.arrayClass);
1925 }
1926 // </editor-fold>
1928 // <editor-fold defaultstate="collapsed" desc="asSuper">
1929 /**
1930 * Return the (most specific) base type of t that starts with the
1931 * given symbol. If none exists, return null.
1932 *
1933 * @param t a type
1934 * @param sym a symbol
1935 */
1936 public Type asSuper(Type t, Symbol sym) {
1937 return asSuper.visit(t, sym);
1938 }
1939 // where
1940 private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() {
1942 public Type visitType(Type t, Symbol sym) {
1943 return null;
1944 }
1946 @Override
1947 public Type visitClassType(ClassType t, Symbol sym) {
1948 if (t.tsym == sym)
1949 return t;
1951 Type st = supertype(t);
1952 if (st.hasTag(CLASS) || st.hasTag(TYPEVAR) || st.hasTag(ERROR)) {
1953 Type x = asSuper(st, sym);
1954 if (x != null)
1955 return x;
1956 }
1957 if ((sym.flags() & INTERFACE) != 0) {
1958 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
1959 Type x = asSuper(l.head, sym);
1960 if (x != null)
1961 return x;
1962 }
1963 }
1964 return null;
1965 }
1967 @Override
1968 public Type visitArrayType(ArrayType t, Symbol sym) {
1969 return isSubtype(t, sym.type) ? sym.type : null;
1970 }
1972 @Override
1973 public Type visitTypeVar(TypeVar t, Symbol sym) {
1974 if (t.tsym == sym)
1975 return t;
1976 else
1977 return asSuper(t.bound, sym);
1978 }
1980 @Override
1981 public Type visitErrorType(ErrorType t, Symbol sym) {
1982 return t;
1983 }
1984 };
1986 /**
1987 * Return the base type of t or any of its outer types that starts
1988 * with the given symbol. If none exists, return null.
1989 *
1990 * @param t a type
1991 * @param sym a symbol
1992 */
1993 public Type asOuterSuper(Type t, Symbol sym) {
1994 switch (t.getTag()) {
1995 case CLASS:
1996 do {
1997 Type s = asSuper(t, sym);
1998 if (s != null) return s;
1999 t = t.getEnclosingType();
2000 } while (t.hasTag(CLASS));
2001 return null;
2002 case ARRAY:
2003 return isSubtype(t, sym.type) ? sym.type : null;
2004 case TYPEVAR:
2005 return asSuper(t, sym);
2006 case ERROR:
2007 return t;
2008 default:
2009 return null;
2010 }
2011 }
2013 /**
2014 * Return the base type of t or any of its enclosing types that
2015 * starts with the given symbol. If none exists, return null.
2016 *
2017 * @param t a type
2018 * @param sym a symbol
2019 */
2020 public Type asEnclosingSuper(Type t, Symbol sym) {
2021 switch (t.getTag()) {
2022 case CLASS:
2023 do {
2024 Type s = asSuper(t, sym);
2025 if (s != null) return s;
2026 Type outer = t.getEnclosingType();
2027 t = (outer.hasTag(CLASS)) ? outer :
2028 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type :
2029 Type.noType;
2030 } while (t.hasTag(CLASS));
2031 return null;
2032 case ARRAY:
2033 return isSubtype(t, sym.type) ? sym.type : null;
2034 case TYPEVAR:
2035 return asSuper(t, sym);
2036 case ERROR:
2037 return t;
2038 default:
2039 return null;
2040 }
2041 }
2042 // </editor-fold>
2044 // <editor-fold defaultstate="collapsed" desc="memberType">
2045 /**
2046 * The type of given symbol, seen as a member of t.
2047 *
2048 * @param t a type
2049 * @param sym a symbol
2050 */
2051 public Type memberType(Type t, Symbol sym) {
2052 return (sym.flags() & STATIC) != 0
2053 ? sym.type
2054 : memberType.visit(t, sym);
2055 }
2056 // where
2057 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() {
2059 public Type visitType(Type t, Symbol sym) {
2060 return sym.type;
2061 }
2063 @Override
2064 public Type visitWildcardType(WildcardType t, Symbol sym) {
2065 return memberType(upperBound(t), sym);
2066 }
2068 @Override
2069 public Type visitClassType(ClassType t, Symbol sym) {
2070 Symbol owner = sym.owner;
2071 long flags = sym.flags();
2072 if (((flags & STATIC) == 0) && owner.type.isParameterized()) {
2073 Type base = asOuterSuper(t, owner);
2074 //if t is an intersection type T = CT & I1 & I2 ... & In
2075 //its supertypes CT, I1, ... In might contain wildcards
2076 //so we need to go through capture conversion
2077 base = t.isCompound() ? capture(base) : base;
2078 if (base != null) {
2079 List<Type> ownerParams = owner.type.allparams();
2080 List<Type> baseParams = base.allparams();
2081 if (ownerParams.nonEmpty()) {
2082 if (baseParams.isEmpty()) {
2083 // then base is a raw type
2084 return erasure(sym.type);
2085 } else {
2086 return subst(sym.type, ownerParams, baseParams);
2087 }
2088 }
2089 }
2090 }
2091 return sym.type;
2092 }
2094 @Override
2095 public Type visitTypeVar(TypeVar t, Symbol sym) {
2096 return memberType(t.bound, sym);
2097 }
2099 @Override
2100 public Type visitErrorType(ErrorType t, Symbol sym) {
2101 return t;
2102 }
2103 };
2104 // </editor-fold>
2106 // <editor-fold defaultstate="collapsed" desc="isAssignable">
2107 public boolean isAssignable(Type t, Type s) {
2108 return isAssignable(t, s, noWarnings);
2109 }
2111 /**
2112 * Is t assignable to s?<br>
2113 * Equivalent to subtype except for constant values and raw
2114 * types.<br>
2115 * (not defined for Method and ForAll types)
2116 */
2117 public boolean isAssignable(Type t, Type s, Warner warn) {
2118 if (t.hasTag(ERROR))
2119 return true;
2120 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) {
2121 int value = ((Number)t.constValue()).intValue();
2122 switch (s.getTag()) {
2123 case BYTE:
2124 if (Byte.MIN_VALUE <= value && value <= Byte.MAX_VALUE)
2125 return true;
2126 break;
2127 case CHAR:
2128 if (Character.MIN_VALUE <= value && value <= Character.MAX_VALUE)
2129 return true;
2130 break;
2131 case SHORT:
2132 if (Short.MIN_VALUE <= value && value <= Short.MAX_VALUE)
2133 return true;
2134 break;
2135 case INT:
2136 return true;
2137 case CLASS:
2138 switch (unboxedType(s).getTag()) {
2139 case BYTE:
2140 case CHAR:
2141 case SHORT:
2142 return isAssignable(t, unboxedType(s), warn);
2143 }
2144 break;
2145 }
2146 }
2147 return isConvertible(t, s, warn);
2148 }
2149 // </editor-fold>
2151 // <editor-fold defaultstate="collapsed" desc="erasure">
2152 /**
2153 * The erasure of t {@code |t|} -- the type that results when all
2154 * type parameters in t are deleted.
2155 */
2156 public Type erasure(Type t) {
2157 return eraseNotNeeded(t)? t : erasure(t, false);
2158 }
2159 //where
2160 private boolean eraseNotNeeded(Type t) {
2161 // We don't want to erase primitive types and String type as that
2162 // operation is idempotent. Also, erasing these could result in loss
2163 // of information such as constant values attached to such types.
2164 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym);
2165 }
2167 private Type erasure(Type t, boolean recurse) {
2168 if (t.isPrimitive())
2169 return t; /* fast special case */
2170 else
2171 return erasure.visit(t, recurse);
2172 }
2173 // where
2174 private SimpleVisitor<Type, Boolean> erasure = new SimpleVisitor<Type, Boolean>() {
2175 public Type visitType(Type t, Boolean recurse) {
2176 if (t.isPrimitive())
2177 return t; /*fast special case*/
2178 else
2179 return t.map(recurse ? erasureRecFun : erasureFun);
2180 }
2182 @Override
2183 public Type visitWildcardType(WildcardType t, Boolean recurse) {
2184 return erasure(upperBound(t), recurse);
2185 }
2187 @Override
2188 public Type visitClassType(ClassType t, Boolean recurse) {
2189 Type erased = t.tsym.erasure(Types.this);
2190 if (recurse) {
2191 erased = new ErasedClassType(erased.getEnclosingType(),erased.tsym);
2192 }
2193 return erased;
2194 }
2196 @Override
2197 public Type visitTypeVar(TypeVar t, Boolean recurse) {
2198 return erasure(t.bound, recurse);
2199 }
2201 @Override
2202 public Type visitErrorType(ErrorType t, Boolean recurse) {
2203 return t;
2204 }
2206 @Override
2207 public Type visitAnnotatedType(AnnotatedType t, Boolean recurse) {
2208 Type erased = erasure(t.unannotatedType(), recurse);
2209 if (erased.isAnnotated()) {
2210 // This can only happen when the underlying type is a
2211 // type variable and the upper bound of it is annotated.
2212 // The annotation on the type variable overrides the one
2213 // on the bound.
2214 erased = ((AnnotatedType)erased).unannotatedType();
2215 }
2216 return erased.annotatedType(t.getAnnotationMirrors());
2217 }
2218 };
2220 private Mapping erasureFun = new Mapping ("erasure") {
2221 public Type apply(Type t) { return erasure(t); }
2222 };
2224 private Mapping erasureRecFun = new Mapping ("erasureRecursive") {
2225 public Type apply(Type t) { return erasureRecursive(t); }
2226 };
2228 public List<Type> erasure(List<Type> ts) {
2229 return Type.map(ts, erasureFun);
2230 }
2232 public Type erasureRecursive(Type t) {
2233 return erasure(t, true);
2234 }
2236 public List<Type> erasureRecursive(List<Type> ts) {
2237 return Type.map(ts, erasureRecFun);
2238 }
2239 // </editor-fold>
2241 // <editor-fold defaultstate="collapsed" desc="makeCompoundType">
2242 /**
2243 * Make a compound type from non-empty list of types
2244 *
2245 * @param bounds the types from which the compound type is formed
2246 * @param supertype is objectType if all bounds are interfaces,
2247 * null otherwise.
2248 */
2249 public Type makeCompoundType(List<Type> bounds) {
2250 return makeCompoundType(bounds, bounds.head.tsym.isInterface());
2251 }
2252 public Type makeCompoundType(List<Type> bounds, boolean allInterfaces) {
2253 Assert.check(bounds.nonEmpty());
2254 Type firstExplicitBound = bounds.head;
2255 if (allInterfaces) {
2256 bounds = bounds.prepend(syms.objectType);
2257 }
2258 ClassSymbol bc =
2259 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC,
2260 Type.moreInfo
2261 ? names.fromString(bounds.toString())
2262 : names.empty,
2263 null,
2264 syms.noSymbol);
2265 bc.type = new IntersectionClassType(bounds, bc, allInterfaces);
2266 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ?
2267 syms.objectType : // error condition, recover
2268 erasure(firstExplicitBound);
2269 bc.members_field = new Scope(bc);
2270 return bc.type;
2271 }
2273 /**
2274 * A convenience wrapper for {@link #makeCompoundType(List)}; the
2275 * arguments are converted to a list and passed to the other
2276 * method. Note that this might cause a symbol completion.
2277 * Hence, this version of makeCompoundType may not be called
2278 * during a classfile read.
2279 */
2280 public Type makeCompoundType(Type bound1, Type bound2) {
2281 return makeCompoundType(List.of(bound1, bound2));
2282 }
2283 // </editor-fold>
2285 // <editor-fold defaultstate="collapsed" desc="supertype">
2286 public Type supertype(Type t) {
2287 return supertype.visit(t);
2288 }
2289 // where
2290 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() {
2292 public Type visitType(Type t, Void ignored) {
2293 // A note on wildcards: there is no good way to
2294 // determine a supertype for a super bounded wildcard.
2295 return null;
2296 }
2298 @Override
2299 public Type visitClassType(ClassType t, Void ignored) {
2300 if (t.supertype_field == null) {
2301 Type supertype = ((ClassSymbol)t.tsym).getSuperclass();
2302 // An interface has no superclass; its supertype is Object.
2303 if (t.isInterface())
2304 supertype = ((ClassType)t.tsym.type).supertype_field;
2305 if (t.supertype_field == null) {
2306 List<Type> actuals = classBound(t).allparams();
2307 List<Type> formals = t.tsym.type.allparams();
2308 if (t.hasErasedSupertypes()) {
2309 t.supertype_field = erasureRecursive(supertype);
2310 } else if (formals.nonEmpty()) {
2311 t.supertype_field = subst(supertype, formals, actuals);
2312 }
2313 else {
2314 t.supertype_field = supertype;
2315 }
2316 }
2317 }
2318 return t.supertype_field;
2319 }
2321 /**
2322 * The supertype is always a class type. If the type
2323 * variable's bounds start with a class type, this is also
2324 * the supertype. Otherwise, the supertype is
2325 * java.lang.Object.
2326 */
2327 @Override
2328 public Type visitTypeVar(TypeVar t, Void ignored) {
2329 if (t.bound.hasTag(TYPEVAR) ||
2330 (!t.bound.isCompound() && !t.bound.isInterface())) {
2331 return t.bound;
2332 } else {
2333 return supertype(t.bound);
2334 }
2335 }
2337 @Override
2338 public Type visitArrayType(ArrayType t, Void ignored) {
2339 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType))
2340 return arraySuperType();
2341 else
2342 return new ArrayType(supertype(t.elemtype), t.tsym);
2343 }
2345 @Override
2346 public Type visitErrorType(ErrorType t, Void ignored) {
2347 return Type.noType;
2348 }
2349 };
2350 // </editor-fold>
2352 // <editor-fold defaultstate="collapsed" desc="interfaces">
2353 /**
2354 * Return the interfaces implemented by this class.
2355 */
2356 public List<Type> interfaces(Type t) {
2357 return interfaces.visit(t);
2358 }
2359 // where
2360 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() {
2362 public List<Type> visitType(Type t, Void ignored) {
2363 return List.nil();
2364 }
2366 @Override
2367 public List<Type> visitClassType(ClassType t, Void ignored) {
2368 if (t.interfaces_field == null) {
2369 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces();
2370 if (t.interfaces_field == null) {
2371 // If t.interfaces_field is null, then t must
2372 // be a parameterized type (not to be confused
2373 // with a generic type declaration).
2374 // Terminology:
2375 // Parameterized type: List<String>
2376 // Generic type declaration: class List<E> { ... }
2377 // So t corresponds to List<String> and
2378 // t.tsym.type corresponds to List<E>.
2379 // The reason t must be parameterized type is
2380 // that completion will happen as a side
2381 // effect of calling
2382 // ClassSymbol.getInterfaces. Since
2383 // t.interfaces_field is null after
2384 // completion, we can assume that t is not the
2385 // type of a class/interface declaration.
2386 Assert.check(t != t.tsym.type, t);
2387 List<Type> actuals = t.allparams();
2388 List<Type> formals = t.tsym.type.allparams();
2389 if (t.hasErasedSupertypes()) {
2390 t.interfaces_field = erasureRecursive(interfaces);
2391 } else if (formals.nonEmpty()) {
2392 t.interfaces_field =
2393 upperBounds(subst(interfaces, formals, actuals));
2394 }
2395 else {
2396 t.interfaces_field = interfaces;
2397 }
2398 }
2399 }
2400 return t.interfaces_field;
2401 }
2403 @Override
2404 public List<Type> visitTypeVar(TypeVar t, Void ignored) {
2405 if (t.bound.isCompound())
2406 return interfaces(t.bound);
2408 if (t.bound.isInterface())
2409 return List.of(t.bound);
2411 return List.nil();
2412 }
2413 };
2415 public List<Type> directSupertypes(Type t) {
2416 return directSupertypes.visit(t);
2417 }
2418 // where
2419 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() {
2421 public List<Type> visitType(final Type type, final Void ignored) {
2422 if (!type.isCompound()) {
2423 final Type sup = supertype(type);
2424 return (sup == Type.noType || sup == type || sup == null)
2425 ? interfaces(type)
2426 : interfaces(type).prepend(sup);
2427 } else {
2428 return visitIntersectionType((IntersectionClassType) type);
2429 }
2430 }
2432 private List<Type> visitIntersectionType(final IntersectionClassType it) {
2433 return it.getExplicitComponents();
2434 }
2436 };
2438 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) {
2439 for (Type i2 : interfaces(origin.type)) {
2440 if (isym == i2.tsym) return true;
2441 }
2442 return false;
2443 }
2444 // </editor-fold>
2446 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw">
2447 Map<Type,Boolean> isDerivedRawCache = new HashMap<Type,Boolean>();
2449 public boolean isDerivedRaw(Type t) {
2450 Boolean result = isDerivedRawCache.get(t);
2451 if (result == null) {
2452 result = isDerivedRawInternal(t);
2453 isDerivedRawCache.put(t, result);
2454 }
2455 return result;
2456 }
2458 public boolean isDerivedRawInternal(Type t) {
2459 if (t.isErroneous())
2460 return false;
2461 return
2462 t.isRaw() ||
2463 supertype(t) != null && isDerivedRaw(supertype(t)) ||
2464 isDerivedRaw(interfaces(t));
2465 }
2467 public boolean isDerivedRaw(List<Type> ts) {
2468 List<Type> l = ts;
2469 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail;
2470 return l.nonEmpty();
2471 }
2472 // </editor-fold>
2474 // <editor-fold defaultstate="collapsed" desc="setBounds">
2475 /**
2476 * Set the bounds field of the given type variable to reflect a
2477 * (possibly multiple) list of bounds.
2478 * @param t a type variable
2479 * @param bounds the bounds, must be nonempty
2480 * @param supertype is objectType if all bounds are interfaces,
2481 * null otherwise.
2482 */
2483 public void setBounds(TypeVar t, List<Type> bounds) {
2484 setBounds(t, bounds, bounds.head.tsym.isInterface());
2485 }
2487 /**
2488 * Same as {@link #setBounds(Type.TypeVar,List,Type)}, except that
2489 * third parameter is computed directly, as follows: if all
2490 * all bounds are interface types, the computed supertype is Object,
2491 * otherwise the supertype is simply left null (in this case, the supertype
2492 * is assumed to be the head of the bound list passed as second argument).
2493 * Note that this check might cause a symbol completion. Hence, this version of
2494 * setBounds may not be called during a classfile read.
2495 */
2496 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) {
2497 t.bound = bounds.tail.isEmpty() ?
2498 bounds.head :
2499 makeCompoundType(bounds, allInterfaces);
2500 t.rank_field = -1;
2501 }
2502 // </editor-fold>
2504 // <editor-fold defaultstate="collapsed" desc="getBounds">
2505 /**
2506 * Return list of bounds of the given type variable.
2507 */
2508 public List<Type> getBounds(TypeVar t) {
2509 if (t.bound.hasTag(NONE))
2510 return List.nil();
2511 else if (t.bound.isErroneous() || !t.bound.isCompound())
2512 return List.of(t.bound);
2513 else if ((erasure(t).tsym.flags() & INTERFACE) == 0)
2514 return interfaces(t).prepend(supertype(t));
2515 else
2516 // No superclass was given in bounds.
2517 // In this case, supertype is Object, erasure is first interface.
2518 return interfaces(t);
2519 }
2520 // </editor-fold>
2522 // <editor-fold defaultstate="collapsed" desc="classBound">
2523 /**
2524 * If the given type is a (possibly selected) type variable,
2525 * return the bounding class of this type, otherwise return the
2526 * type itself.
2527 */
2528 public Type classBound(Type t) {
2529 return classBound.visit(t);
2530 }
2531 // where
2532 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() {
2534 public Type visitType(Type t, Void ignored) {
2535 return t;
2536 }
2538 @Override
2539 public Type visitClassType(ClassType t, Void ignored) {
2540 Type outer1 = classBound(t.getEnclosingType());
2541 if (outer1 != t.getEnclosingType())
2542 return new ClassType(outer1, t.getTypeArguments(), t.tsym);
2543 else
2544 return t;
2545 }
2547 @Override
2548 public Type visitTypeVar(TypeVar t, Void ignored) {
2549 return classBound(supertype(t));
2550 }
2552 @Override
2553 public Type visitErrorType(ErrorType t, Void ignored) {
2554 return t;
2555 }
2556 };
2557 // </editor-fold>
2559 // <editor-fold defaultstate="collapsed" desc="sub signature / override equivalence">
2560 /**
2561 * Returns true iff the first signature is a <em>sub
2562 * signature</em> of the other. This is <b>not</b> an equivalence
2563 * relation.
2564 *
2565 * @jls section 8.4.2.
2566 * @see #overrideEquivalent(Type t, Type s)
2567 * @param t first signature (possibly raw).
2568 * @param s second signature (could be subjected to erasure).
2569 * @return true if t is a sub signature of s.
2570 */
2571 public boolean isSubSignature(Type t, Type s) {
2572 return isSubSignature(t, s, true);
2573 }
2575 public boolean isSubSignature(Type t, Type s, boolean strict) {
2576 return hasSameArgs(t, s, strict) || hasSameArgs(t, erasure(s), strict);
2577 }
2579 /**
2580 * Returns true iff these signatures are related by <em>override
2581 * equivalence</em>. This is the natural extension of
2582 * isSubSignature to an equivalence relation.
2583 *
2584 * @jls section 8.4.2.
2585 * @see #isSubSignature(Type t, Type s)
2586 * @param t a signature (possible raw, could be subjected to
2587 * erasure).
2588 * @param s a signature (possible raw, could be subjected to
2589 * erasure).
2590 * @return true if either argument is a sub signature of the other.
2591 */
2592 public boolean overrideEquivalent(Type t, Type s) {
2593 return hasSameArgs(t, s) ||
2594 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s);
2595 }
2597 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) {
2598 for (Scope.Entry e = syms.objectType.tsym.members().lookup(msym.name) ; e.scope != null ; e = e.next()) {
2599 if (msym.overrides(e.sym, origin, Types.this, true)) {
2600 return true;
2601 }
2602 }
2603 return false;
2604 }
2606 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site">
2607 class ImplementationCache {
2609 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map =
2610 new WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>>();
2612 class Entry {
2613 final MethodSymbol cachedImpl;
2614 final Filter<Symbol> implFilter;
2615 final boolean checkResult;
2616 final int prevMark;
2618 public Entry(MethodSymbol cachedImpl,
2619 Filter<Symbol> scopeFilter,
2620 boolean checkResult,
2621 int prevMark) {
2622 this.cachedImpl = cachedImpl;
2623 this.implFilter = scopeFilter;
2624 this.checkResult = checkResult;
2625 this.prevMark = prevMark;
2626 }
2628 boolean matches(Filter<Symbol> scopeFilter, boolean checkResult, int mark) {
2629 return this.implFilter == scopeFilter &&
2630 this.checkResult == checkResult &&
2631 this.prevMark == mark;
2632 }
2633 }
2635 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2636 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms);
2637 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null;
2638 if (cache == null) {
2639 cache = new HashMap<TypeSymbol, Entry>();
2640 _map.put(ms, new SoftReference<Map<TypeSymbol, Entry>>(cache));
2641 }
2642 Entry e = cache.get(origin);
2643 CompoundScope members = membersClosure(origin.type, true);
2644 if (e == null ||
2645 !e.matches(implFilter, checkResult, members.getMark())) {
2646 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter);
2647 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark()));
2648 return impl;
2649 }
2650 else {
2651 return e.cachedImpl;
2652 }
2653 }
2655 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2656 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) {
2657 while (t.hasTag(TYPEVAR))
2658 t = t.getUpperBound();
2659 TypeSymbol c = t.tsym;
2660 for (Scope.Entry e = c.members().lookup(ms.name, implFilter);
2661 e.scope != null;
2662 e = e.next(implFilter)) {
2663 if (e.sym != null &&
2664 e.sym.overrides(ms, origin, Types.this, checkResult))
2665 return (MethodSymbol)e.sym;
2666 }
2667 }
2668 return null;
2669 }
2670 }
2672 private ImplementationCache implCache = new ImplementationCache();
2674 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2675 return implCache.get(ms, origin, checkResult, implFilter);
2676 }
2677 // </editor-fold>
2679 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site">
2680 class MembersClosureCache extends SimpleVisitor<CompoundScope, Boolean> {
2682 private WeakHashMap<TypeSymbol, Entry> _map =
2683 new WeakHashMap<TypeSymbol, Entry>();
2685 class Entry {
2686 final boolean skipInterfaces;
2687 final CompoundScope compoundScope;
2689 public Entry(boolean skipInterfaces, CompoundScope compoundScope) {
2690 this.skipInterfaces = skipInterfaces;
2691 this.compoundScope = compoundScope;
2692 }
2694 boolean matches(boolean skipInterfaces) {
2695 return this.skipInterfaces == skipInterfaces;
2696 }
2697 }
2699 List<TypeSymbol> seenTypes = List.nil();
2701 /** members closure visitor methods **/
2703 public CompoundScope visitType(Type t, Boolean skipInterface) {
2704 return null;
2705 }
2707 @Override
2708 public CompoundScope visitClassType(ClassType t, Boolean skipInterface) {
2709 if (seenTypes.contains(t.tsym)) {
2710 //this is possible when an interface is implemented in multiple
2711 //superclasses, or when a classs hierarchy is circular - in such
2712 //cases we don't need to recurse (empty scope is returned)
2713 return new CompoundScope(t.tsym);
2714 }
2715 try {
2716 seenTypes = seenTypes.prepend(t.tsym);
2717 ClassSymbol csym = (ClassSymbol)t.tsym;
2718 Entry e = _map.get(csym);
2719 if (e == null || !e.matches(skipInterface)) {
2720 CompoundScope membersClosure = new CompoundScope(csym);
2721 if (!skipInterface) {
2722 for (Type i : interfaces(t)) {
2723 membersClosure.addSubScope(visit(i, skipInterface));
2724 }
2725 }
2726 membersClosure.addSubScope(visit(supertype(t), skipInterface));
2727 membersClosure.addSubScope(csym.members());
2728 e = new Entry(skipInterface, membersClosure);
2729 _map.put(csym, e);
2730 }
2731 return e.compoundScope;
2732 }
2733 finally {
2734 seenTypes = seenTypes.tail;
2735 }
2736 }
2738 @Override
2739 public CompoundScope visitTypeVar(TypeVar t, Boolean skipInterface) {
2740 return visit(t.getUpperBound(), skipInterface);
2741 }
2742 }
2744 private MembersClosureCache membersCache = new MembersClosureCache();
2746 public CompoundScope membersClosure(Type site, boolean skipInterface) {
2747 return membersCache.visit(site, skipInterface);
2748 }
2749 // </editor-fold>
2752 //where
2753 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) {
2754 Filter<Symbol> filter = new MethodFilter(ms, site);
2755 List<MethodSymbol> candidates = List.nil();
2756 for (Symbol s : membersClosure(site, false).getElements(filter)) {
2757 if (!site.tsym.isInterface() && !s.owner.isInterface()) {
2758 return List.of((MethodSymbol)s);
2759 } else if (!candidates.contains(s)) {
2760 candidates = candidates.prepend((MethodSymbol)s);
2761 }
2762 }
2763 return prune(candidates);
2764 }
2766 public List<MethodSymbol> prune(List<MethodSymbol> methods) {
2767 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>();
2768 for (MethodSymbol m1 : methods) {
2769 boolean isMin_m1 = true;
2770 for (MethodSymbol m2 : methods) {
2771 if (m1 == m2) continue;
2772 if (m2.owner != m1.owner &&
2773 asSuper(m2.owner.type, m1.owner) != null) {
2774 isMin_m1 = false;
2775 break;
2776 }
2777 }
2778 if (isMin_m1)
2779 methodsMin.append(m1);
2780 }
2781 return methodsMin.toList();
2782 }
2783 // where
2784 private class MethodFilter implements Filter<Symbol> {
2786 Symbol msym;
2787 Type site;
2789 MethodFilter(Symbol msym, Type site) {
2790 this.msym = msym;
2791 this.site = site;
2792 }
2794 public boolean accepts(Symbol s) {
2795 return s.kind == Kinds.MTH &&
2796 s.name == msym.name &&
2797 (s.flags() & SYNTHETIC) == 0 &&
2798 s.isInheritedIn(site.tsym, Types.this) &&
2799 overrideEquivalent(memberType(site, s), memberType(site, msym));
2800 }
2801 };
2802 // </editor-fold>
2804 /**
2805 * Does t have the same arguments as s? It is assumed that both
2806 * types are (possibly polymorphic) method types. Monomorphic
2807 * method types "have the same arguments", if their argument lists
2808 * are equal. Polymorphic method types "have the same arguments",
2809 * if they have the same arguments after renaming all type
2810 * variables of one to corresponding type variables in the other,
2811 * where correspondence is by position in the type parameter list.
2812 */
2813 public boolean hasSameArgs(Type t, Type s) {
2814 return hasSameArgs(t, s, true);
2815 }
2817 public boolean hasSameArgs(Type t, Type s, boolean strict) {
2818 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict);
2819 }
2821 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) {
2822 return hasSameArgs.visit(t, s);
2823 }
2824 // where
2825 private class HasSameArgs extends TypeRelation {
2827 boolean strict;
2829 public HasSameArgs(boolean strict) {
2830 this.strict = strict;
2831 }
2833 public Boolean visitType(Type t, Type s) {
2834 throw new AssertionError();
2835 }
2837 @Override
2838 public Boolean visitMethodType(MethodType t, Type s) {
2839 return s.hasTag(METHOD)
2840 && containsTypeEquivalent(t.argtypes, s.getParameterTypes());
2841 }
2843 @Override
2844 public Boolean visitForAll(ForAll t, Type s) {
2845 if (!s.hasTag(FORALL))
2846 return strict ? false : visitMethodType(t.asMethodType(), s);
2848 ForAll forAll = (ForAll)s;
2849 return hasSameBounds(t, forAll)
2850 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
2851 }
2853 @Override
2854 public Boolean visitErrorType(ErrorType t, Type s) {
2855 return false;
2856 }
2857 };
2859 TypeRelation hasSameArgs_strict = new HasSameArgs(true);
2860 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false);
2862 // </editor-fold>
2864 // <editor-fold defaultstate="collapsed" desc="subst">
2865 public List<Type> subst(List<Type> ts,
2866 List<Type> from,
2867 List<Type> to) {
2868 return new Subst(from, to).subst(ts);
2869 }
2871 /**
2872 * Substitute all occurrences of a type in `from' with the
2873 * corresponding type in `to' in 't'. Match lists `from' and `to'
2874 * from the right: If lists have different length, discard leading
2875 * elements of the longer list.
2876 */
2877 public Type subst(Type t, List<Type> from, List<Type> to) {
2878 return new Subst(from, to).subst(t);
2879 }
2881 private class Subst extends UnaryVisitor<Type> {
2882 List<Type> from;
2883 List<Type> to;
2885 public Subst(List<Type> from, List<Type> to) {
2886 int fromLength = from.length();
2887 int toLength = to.length();
2888 while (fromLength > toLength) {
2889 fromLength--;
2890 from = from.tail;
2891 }
2892 while (fromLength < toLength) {
2893 toLength--;
2894 to = to.tail;
2895 }
2896 this.from = from;
2897 this.to = to;
2898 }
2900 Type subst(Type t) {
2901 if (from.tail == null)
2902 return t;
2903 else
2904 return visit(t);
2905 }
2907 List<Type> subst(List<Type> ts) {
2908 if (from.tail == null)
2909 return ts;
2910 boolean wild = false;
2911 if (ts.nonEmpty() && from.nonEmpty()) {
2912 Type head1 = subst(ts.head);
2913 List<Type> tail1 = subst(ts.tail);
2914 if (head1 != ts.head || tail1 != ts.tail)
2915 return tail1.prepend(head1);
2916 }
2917 return ts;
2918 }
2920 public Type visitType(Type t, Void ignored) {
2921 return t;
2922 }
2924 @Override
2925 public Type visitMethodType(MethodType t, Void ignored) {
2926 List<Type> argtypes = subst(t.argtypes);
2927 Type restype = subst(t.restype);
2928 List<Type> thrown = subst(t.thrown);
2929 if (argtypes == t.argtypes &&
2930 restype == t.restype &&
2931 thrown == t.thrown)
2932 return t;
2933 else
2934 return new MethodType(argtypes, restype, thrown, t.tsym);
2935 }
2937 @Override
2938 public Type visitTypeVar(TypeVar t, Void ignored) {
2939 for (List<Type> from = this.from, to = this.to;
2940 from.nonEmpty();
2941 from = from.tail, to = to.tail) {
2942 if (t == from.head) {
2943 return to.head.withTypeVar(t);
2944 }
2945 }
2946 return t;
2947 }
2949 @Override
2950 public Type visitClassType(ClassType t, Void ignored) {
2951 if (!t.isCompound()) {
2952 List<Type> typarams = t.getTypeArguments();
2953 List<Type> typarams1 = subst(typarams);
2954 Type outer = t.getEnclosingType();
2955 Type outer1 = subst(outer);
2956 if (typarams1 == typarams && outer1 == outer)
2957 return t;
2958 else
2959 return new ClassType(outer1, typarams1, t.tsym);
2960 } else {
2961 Type st = subst(supertype(t));
2962 List<Type> is = upperBounds(subst(interfaces(t)));
2963 if (st == supertype(t) && is == interfaces(t))
2964 return t;
2965 else
2966 return makeCompoundType(is.prepend(st));
2967 }
2968 }
2970 @Override
2971 public Type visitWildcardType(WildcardType t, Void ignored) {
2972 Type bound = t.type;
2973 if (t.kind != BoundKind.UNBOUND)
2974 bound = subst(bound);
2975 if (bound == t.type) {
2976 return t;
2977 } else {
2978 if (t.isExtendsBound() && bound.isExtendsBound())
2979 bound = upperBound(bound);
2980 return new WildcardType(bound, t.kind, syms.boundClass, t.bound);
2981 }
2982 }
2984 @Override
2985 public Type visitArrayType(ArrayType t, Void ignored) {
2986 Type elemtype = subst(t.elemtype);
2987 if (elemtype == t.elemtype)
2988 return t;
2989 else
2990 return new ArrayType(elemtype, t.tsym);
2991 }
2993 @Override
2994 public Type visitForAll(ForAll t, Void ignored) {
2995 if (Type.containsAny(to, t.tvars)) {
2996 //perform alpha-renaming of free-variables in 't'
2997 //if 'to' types contain variables that are free in 't'
2998 List<Type> freevars = newInstances(t.tvars);
2999 t = new ForAll(freevars,
3000 Types.this.subst(t.qtype, t.tvars, freevars));
3001 }
3002 List<Type> tvars1 = substBounds(t.tvars, from, to);
3003 Type qtype1 = subst(t.qtype);
3004 if (tvars1 == t.tvars && qtype1 == t.qtype) {
3005 return t;
3006 } else if (tvars1 == t.tvars) {
3007 return new ForAll(tvars1, qtype1);
3008 } else {
3009 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1));
3010 }
3011 }
3013 @Override
3014 public Type visitErrorType(ErrorType t, Void ignored) {
3015 return t;
3016 }
3017 }
3019 public List<Type> substBounds(List<Type> tvars,
3020 List<Type> from,
3021 List<Type> to) {
3022 if (tvars.isEmpty())
3023 return tvars;
3024 ListBuffer<Type> newBoundsBuf = new ListBuffer<>();
3025 boolean changed = false;
3026 // calculate new bounds
3027 for (Type t : tvars) {
3028 TypeVar tv = (TypeVar) t;
3029 Type bound = subst(tv.bound, from, to);
3030 if (bound != tv.bound)
3031 changed = true;
3032 newBoundsBuf.append(bound);
3033 }
3034 if (!changed)
3035 return tvars;
3036 ListBuffer<Type> newTvars = new ListBuffer<>();
3037 // create new type variables without bounds
3038 for (Type t : tvars) {
3039 newTvars.append(new TypeVar(t.tsym, null, syms.botType));
3040 }
3041 // the new bounds should use the new type variables in place
3042 // of the old
3043 List<Type> newBounds = newBoundsBuf.toList();
3044 from = tvars;
3045 to = newTvars.toList();
3046 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) {
3047 newBounds.head = subst(newBounds.head, from, to);
3048 }
3049 newBounds = newBoundsBuf.toList();
3050 // set the bounds of new type variables to the new bounds
3051 for (Type t : newTvars.toList()) {
3052 TypeVar tv = (TypeVar) t;
3053 tv.bound = newBounds.head;
3054 newBounds = newBounds.tail;
3055 }
3056 return newTvars.toList();
3057 }
3059 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) {
3060 Type bound1 = subst(t.bound, from, to);
3061 if (bound1 == t.bound)
3062 return t;
3063 else {
3064 // create new type variable without bounds
3065 TypeVar tv = new TypeVar(t.tsym, null, syms.botType);
3066 // the new bound should use the new type variable in place
3067 // of the old
3068 tv.bound = subst(bound1, List.<Type>of(t), List.<Type>of(tv));
3069 return tv;
3070 }
3071 }
3072 // </editor-fold>
3074 // <editor-fold defaultstate="collapsed" desc="hasSameBounds">
3075 /**
3076 * Does t have the same bounds for quantified variables as s?
3077 */
3078 public boolean hasSameBounds(ForAll t, ForAll s) {
3079 List<Type> l1 = t.tvars;
3080 List<Type> l2 = s.tvars;
3081 while (l1.nonEmpty() && l2.nonEmpty() &&
3082 isSameType(l1.head.getUpperBound(),
3083 subst(l2.head.getUpperBound(),
3084 s.tvars,
3085 t.tvars))) {
3086 l1 = l1.tail;
3087 l2 = l2.tail;
3088 }
3089 return l1.isEmpty() && l2.isEmpty();
3090 }
3091 // </editor-fold>
3093 // <editor-fold defaultstate="collapsed" desc="newInstances">
3094 /** Create new vector of type variables from list of variables
3095 * changing all recursive bounds from old to new list.
3096 */
3097 public List<Type> newInstances(List<Type> tvars) {
3098 List<Type> tvars1 = Type.map(tvars, newInstanceFun);
3099 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) {
3100 TypeVar tv = (TypeVar) l.head;
3101 tv.bound = subst(tv.bound, tvars, tvars1);
3102 }
3103 return tvars1;
3104 }
3105 private static final Mapping newInstanceFun = new Mapping("newInstanceFun") {
3106 public Type apply(Type t) { return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound()); }
3107 };
3108 // </editor-fold>
3110 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) {
3111 return original.accept(methodWithParameters, newParams);
3112 }
3113 // where
3114 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() {
3115 public Type visitType(Type t, List<Type> newParams) {
3116 throw new IllegalArgumentException("Not a method type: " + t);
3117 }
3118 public Type visitMethodType(MethodType t, List<Type> newParams) {
3119 return new MethodType(newParams, t.restype, t.thrown, t.tsym);
3120 }
3121 public Type visitForAll(ForAll t, List<Type> newParams) {
3122 return new ForAll(t.tvars, t.qtype.accept(this, newParams));
3123 }
3124 };
3126 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) {
3127 return original.accept(methodWithThrown, newThrown);
3128 }
3129 // where
3130 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() {
3131 public Type visitType(Type t, List<Type> newThrown) {
3132 throw new IllegalArgumentException("Not a method type: " + t);
3133 }
3134 public Type visitMethodType(MethodType t, List<Type> newThrown) {
3135 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym);
3136 }
3137 public Type visitForAll(ForAll t, List<Type> newThrown) {
3138 return new ForAll(t.tvars, t.qtype.accept(this, newThrown));
3139 }
3140 };
3142 public Type createMethodTypeWithReturn(Type original, Type newReturn) {
3143 return original.accept(methodWithReturn, newReturn);
3144 }
3145 // where
3146 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() {
3147 public Type visitType(Type t, Type newReturn) {
3148 throw new IllegalArgumentException("Not a method type: " + t);
3149 }
3150 public Type visitMethodType(MethodType t, Type newReturn) {
3151 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym);
3152 }
3153 public Type visitForAll(ForAll t, Type newReturn) {
3154 return new ForAll(t.tvars, t.qtype.accept(this, newReturn));
3155 }
3156 };
3158 // <editor-fold defaultstate="collapsed" desc="createErrorType">
3159 public Type createErrorType(Type originalType) {
3160 return new ErrorType(originalType, syms.errSymbol);
3161 }
3163 public Type createErrorType(ClassSymbol c, Type originalType) {
3164 return new ErrorType(c, originalType);
3165 }
3167 public Type createErrorType(Name name, TypeSymbol container, Type originalType) {
3168 return new ErrorType(name, container, originalType);
3169 }
3170 // </editor-fold>
3172 // <editor-fold defaultstate="collapsed" desc="rank">
3173 /**
3174 * The rank of a class is the length of the longest path between
3175 * the class and java.lang.Object in the class inheritance
3176 * graph. Undefined for all but reference types.
3177 */
3178 public int rank(Type t) {
3179 t = t.unannotatedType();
3180 switch(t.getTag()) {
3181 case CLASS: {
3182 ClassType cls = (ClassType)t;
3183 if (cls.rank_field < 0) {
3184 Name fullname = cls.tsym.getQualifiedName();
3185 if (fullname == names.java_lang_Object)
3186 cls.rank_field = 0;
3187 else {
3188 int r = rank(supertype(cls));
3189 for (List<Type> l = interfaces(cls);
3190 l.nonEmpty();
3191 l = l.tail) {
3192 if (rank(l.head) > r)
3193 r = rank(l.head);
3194 }
3195 cls.rank_field = r + 1;
3196 }
3197 }
3198 return cls.rank_field;
3199 }
3200 case TYPEVAR: {
3201 TypeVar tvar = (TypeVar)t;
3202 if (tvar.rank_field < 0) {
3203 int r = rank(supertype(tvar));
3204 for (List<Type> l = interfaces(tvar);
3205 l.nonEmpty();
3206 l = l.tail) {
3207 if (rank(l.head) > r) r = rank(l.head);
3208 }
3209 tvar.rank_field = r + 1;
3210 }
3211 return tvar.rank_field;
3212 }
3213 case ERROR:
3214 return 0;
3215 default:
3216 throw new AssertionError();
3217 }
3218 }
3219 // </editor-fold>
3221 /**
3222 * Helper method for generating a string representation of a given type
3223 * accordingly to a given locale
3224 */
3225 public String toString(Type t, Locale locale) {
3226 return Printer.createStandardPrinter(messages).visit(t, locale);
3227 }
3229 /**
3230 * Helper method for generating a string representation of a given type
3231 * accordingly to a given locale
3232 */
3233 public String toString(Symbol t, Locale locale) {
3234 return Printer.createStandardPrinter(messages).visit(t, locale);
3235 }
3237 // <editor-fold defaultstate="collapsed" desc="toString">
3238 /**
3239 * This toString is slightly more descriptive than the one on Type.
3240 *
3241 * @deprecated Types.toString(Type t, Locale l) provides better support
3242 * for localization
3243 */
3244 @Deprecated
3245 public String toString(Type t) {
3246 if (t.hasTag(FORALL)) {
3247 ForAll forAll = (ForAll)t;
3248 return typaramsString(forAll.tvars) + forAll.qtype;
3249 }
3250 return "" + t;
3251 }
3252 // where
3253 private String typaramsString(List<Type> tvars) {
3254 StringBuilder s = new StringBuilder();
3255 s.append('<');
3256 boolean first = true;
3257 for (Type t : tvars) {
3258 if (!first) s.append(", ");
3259 first = false;
3260 appendTyparamString(((TypeVar)t.unannotatedType()), s);
3261 }
3262 s.append('>');
3263 return s.toString();
3264 }
3265 private void appendTyparamString(TypeVar t, StringBuilder buf) {
3266 buf.append(t);
3267 if (t.bound == null ||
3268 t.bound.tsym.getQualifiedName() == names.java_lang_Object)
3269 return;
3270 buf.append(" extends "); // Java syntax; no need for i18n
3271 Type bound = t.bound;
3272 if (!bound.isCompound()) {
3273 buf.append(bound);
3274 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) {
3275 buf.append(supertype(t));
3276 for (Type intf : interfaces(t)) {
3277 buf.append('&');
3278 buf.append(intf);
3279 }
3280 } else {
3281 // No superclass was given in bounds.
3282 // In this case, supertype is Object, erasure is first interface.
3283 boolean first = true;
3284 for (Type intf : interfaces(t)) {
3285 if (!first) buf.append('&');
3286 first = false;
3287 buf.append(intf);
3288 }
3289 }
3290 }
3291 // </editor-fold>
3293 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types">
3294 /**
3295 * A cache for closures.
3296 *
3297 * <p>A closure is a list of all the supertypes and interfaces of
3298 * a class or interface type, ordered by ClassSymbol.precedes
3299 * (that is, subclasses come first, arbitrary but fixed
3300 * otherwise).
3301 */
3302 private Map<Type,List<Type>> closureCache = new HashMap<Type,List<Type>>();
3304 /**
3305 * Returns the closure of a class or interface type.
3306 */
3307 public List<Type> closure(Type t) {
3308 List<Type> cl = closureCache.get(t);
3309 if (cl == null) {
3310 Type st = supertype(t);
3311 if (!t.isCompound()) {
3312 if (st.hasTag(CLASS)) {
3313 cl = insert(closure(st), t);
3314 } else if (st.hasTag(TYPEVAR)) {
3315 cl = closure(st).prepend(t);
3316 } else {
3317 cl = List.of(t);
3318 }
3319 } else {
3320 cl = closure(supertype(t));
3321 }
3322 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail)
3323 cl = union(cl, closure(l.head));
3324 closureCache.put(t, cl);
3325 }
3326 return cl;
3327 }
3329 /**
3330 * Insert a type in a closure
3331 */
3332 public List<Type> insert(List<Type> cl, Type t) {
3333 if (cl.isEmpty() || t.tsym.precedes(cl.head.tsym, this)) {
3334 return cl.prepend(t);
3335 } else if (cl.head.tsym.precedes(t.tsym, this)) {
3336 return insert(cl.tail, t).prepend(cl.head);
3337 } else {
3338 return cl;
3339 }
3340 }
3342 /**
3343 * Form the union of two closures
3344 */
3345 public List<Type> union(List<Type> cl1, List<Type> cl2) {
3346 if (cl1.isEmpty()) {
3347 return cl2;
3348 } else if (cl2.isEmpty()) {
3349 return cl1;
3350 } else if (cl1.head.tsym.precedes(cl2.head.tsym, this)) {
3351 return union(cl1.tail, cl2).prepend(cl1.head);
3352 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) {
3353 return union(cl1, cl2.tail).prepend(cl2.head);
3354 } else {
3355 return union(cl1.tail, cl2.tail).prepend(cl1.head);
3356 }
3357 }
3359 /**
3360 * Intersect two closures
3361 */
3362 public List<Type> intersect(List<Type> cl1, List<Type> cl2) {
3363 if (cl1 == cl2)
3364 return cl1;
3365 if (cl1.isEmpty() || cl2.isEmpty())
3366 return List.nil();
3367 if (cl1.head.tsym.precedes(cl2.head.tsym, this))
3368 return intersect(cl1.tail, cl2);
3369 if (cl2.head.tsym.precedes(cl1.head.tsym, this))
3370 return intersect(cl1, cl2.tail);
3371 if (isSameType(cl1.head, cl2.head))
3372 return intersect(cl1.tail, cl2.tail).prepend(cl1.head);
3373 if (cl1.head.tsym == cl2.head.tsym &&
3374 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) {
3375 if (cl1.head.isParameterized() && cl2.head.isParameterized()) {
3376 Type merge = merge(cl1.head,cl2.head);
3377 return intersect(cl1.tail, cl2.tail).prepend(merge);
3378 }
3379 if (cl1.head.isRaw() || cl2.head.isRaw())
3380 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head));
3381 }
3382 return intersect(cl1.tail, cl2.tail);
3383 }
3384 // where
3385 class TypePair {
3386 final Type t1;
3387 final Type t2;
3388 TypePair(Type t1, Type t2) {
3389 this.t1 = t1;
3390 this.t2 = t2;
3391 }
3392 @Override
3393 public int hashCode() {
3394 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2);
3395 }
3396 @Override
3397 public boolean equals(Object obj) {
3398 if (!(obj instanceof TypePair))
3399 return false;
3400 TypePair typePair = (TypePair)obj;
3401 return isSameType(t1, typePair.t1)
3402 && isSameType(t2, typePair.t2);
3403 }
3404 }
3405 Set<TypePair> mergeCache = new HashSet<TypePair>();
3406 private Type merge(Type c1, Type c2) {
3407 ClassType class1 = (ClassType) c1;
3408 List<Type> act1 = class1.getTypeArguments();
3409 ClassType class2 = (ClassType) c2;
3410 List<Type> act2 = class2.getTypeArguments();
3411 ListBuffer<Type> merged = new ListBuffer<Type>();
3412 List<Type> typarams = class1.tsym.type.getTypeArguments();
3414 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) {
3415 if (containsType(act1.head, act2.head)) {
3416 merged.append(act1.head);
3417 } else if (containsType(act2.head, act1.head)) {
3418 merged.append(act2.head);
3419 } else {
3420 TypePair pair = new TypePair(c1, c2);
3421 Type m;
3422 if (mergeCache.add(pair)) {
3423 m = new WildcardType(lub(upperBound(act1.head),
3424 upperBound(act2.head)),
3425 BoundKind.EXTENDS,
3426 syms.boundClass);
3427 mergeCache.remove(pair);
3428 } else {
3429 m = new WildcardType(syms.objectType,
3430 BoundKind.UNBOUND,
3431 syms.boundClass);
3432 }
3433 merged.append(m.withTypeVar(typarams.head));
3434 }
3435 act1 = act1.tail;
3436 act2 = act2.tail;
3437 typarams = typarams.tail;
3438 }
3439 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty());
3440 return new ClassType(class1.getEnclosingType(), merged.toList(), class1.tsym);
3441 }
3443 /**
3444 * Return the minimum type of a closure, a compound type if no
3445 * unique minimum exists.
3446 */
3447 private Type compoundMin(List<Type> cl) {
3448 if (cl.isEmpty()) return syms.objectType;
3449 List<Type> compound = closureMin(cl);
3450 if (compound.isEmpty())
3451 return null;
3452 else if (compound.tail.isEmpty())
3453 return compound.head;
3454 else
3455 return makeCompoundType(compound);
3456 }
3458 /**
3459 * Return the minimum types of a closure, suitable for computing
3460 * compoundMin or glb.
3461 */
3462 private List<Type> closureMin(List<Type> cl) {
3463 ListBuffer<Type> classes = new ListBuffer<>();
3464 ListBuffer<Type> interfaces = new ListBuffer<>();
3465 while (!cl.isEmpty()) {
3466 Type current = cl.head;
3467 if (current.isInterface())
3468 interfaces.append(current);
3469 else
3470 classes.append(current);
3471 ListBuffer<Type> candidates = new ListBuffer<>();
3472 for (Type t : cl.tail) {
3473 if (!isSubtypeNoCapture(current, t))
3474 candidates.append(t);
3475 }
3476 cl = candidates.toList();
3477 }
3478 return classes.appendList(interfaces).toList();
3479 }
3481 /**
3482 * Return the least upper bound of pair of types. if the lub does
3483 * not exist return null.
3484 */
3485 public Type lub(Type t1, Type t2) {
3486 return lub(List.of(t1, t2));
3487 }
3489 /**
3490 * Return the least upper bound (lub) of set of types. If the lub
3491 * does not exist return the type of null (bottom).
3492 */
3493 public Type lub(List<Type> ts) {
3494 final int ARRAY_BOUND = 1;
3495 final int CLASS_BOUND = 2;
3496 int boundkind = 0;
3497 for (Type t : ts) {
3498 switch (t.getTag()) {
3499 case CLASS:
3500 boundkind |= CLASS_BOUND;
3501 break;
3502 case ARRAY:
3503 boundkind |= ARRAY_BOUND;
3504 break;
3505 case TYPEVAR:
3506 do {
3507 t = t.getUpperBound();
3508 } while (t.hasTag(TYPEVAR));
3509 if (t.hasTag(ARRAY)) {
3510 boundkind |= ARRAY_BOUND;
3511 } else {
3512 boundkind |= CLASS_BOUND;
3513 }
3514 break;
3515 default:
3516 if (t.isPrimitive())
3517 return syms.errType;
3518 }
3519 }
3520 switch (boundkind) {
3521 case 0:
3522 return syms.botType;
3524 case ARRAY_BOUND:
3525 // calculate lub(A[], B[])
3526 List<Type> elements = Type.map(ts, elemTypeFun);
3527 for (Type t : elements) {
3528 if (t.isPrimitive()) {
3529 // if a primitive type is found, then return
3530 // arraySuperType unless all the types are the
3531 // same
3532 Type first = ts.head;
3533 for (Type s : ts.tail) {
3534 if (!isSameType(first, s)) {
3535 // lub(int[], B[]) is Cloneable & Serializable
3536 return arraySuperType();
3537 }
3538 }
3539 // all the array types are the same, return one
3540 // lub(int[], int[]) is int[]
3541 return first;
3542 }
3543 }
3544 // lub(A[], B[]) is lub(A, B)[]
3545 return new ArrayType(lub(elements), syms.arrayClass);
3547 case CLASS_BOUND:
3548 // calculate lub(A, B)
3549 while (!ts.head.hasTag(CLASS) && !ts.head.hasTag(TYPEVAR)) {
3550 ts = ts.tail;
3551 }
3552 Assert.check(!ts.isEmpty());
3553 //step 1 - compute erased candidate set (EC)
3554 List<Type> cl = erasedSupertypes(ts.head);
3555 for (Type t : ts.tail) {
3556 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR))
3557 cl = intersect(cl, erasedSupertypes(t));
3558 }
3559 //step 2 - compute minimal erased candidate set (MEC)
3560 List<Type> mec = closureMin(cl);
3561 //step 3 - for each element G in MEC, compute lci(Inv(G))
3562 List<Type> candidates = List.nil();
3563 for (Type erasedSupertype : mec) {
3564 List<Type> lci = List.of(asSuper(ts.head, erasedSupertype.tsym));
3565 for (Type t : ts) {
3566 lci = intersect(lci, List.of(asSuper(t, erasedSupertype.tsym)));
3567 }
3568 candidates = candidates.appendList(lci);
3569 }
3570 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that
3571 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn))
3572 return compoundMin(candidates);
3574 default:
3575 // calculate lub(A, B[])
3576 List<Type> classes = List.of(arraySuperType());
3577 for (Type t : ts) {
3578 if (!t.hasTag(ARRAY)) // Filter out any arrays
3579 classes = classes.prepend(t);
3580 }
3581 // lub(A, B[]) is lub(A, arraySuperType)
3582 return lub(classes);
3583 }
3584 }
3585 // where
3586 List<Type> erasedSupertypes(Type t) {
3587 ListBuffer<Type> buf = new ListBuffer<>();
3588 for (Type sup : closure(t)) {
3589 if (sup.hasTag(TYPEVAR)) {
3590 buf.append(sup);
3591 } else {
3592 buf.append(erasure(sup));
3593 }
3594 }
3595 return buf.toList();
3596 }
3598 private Type arraySuperType = null;
3599 private Type arraySuperType() {
3600 // initialized lazily to avoid problems during compiler startup
3601 if (arraySuperType == null) {
3602 synchronized (this) {
3603 if (arraySuperType == null) {
3604 // JLS 10.8: all arrays implement Cloneable and Serializable.
3605 arraySuperType = makeCompoundType(List.of(syms.serializableType,
3606 syms.cloneableType), true);
3607 }
3608 }
3609 }
3610 return arraySuperType;
3611 }
3612 // </editor-fold>
3614 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound">
3615 public Type glb(List<Type> ts) {
3616 Type t1 = ts.head;
3617 for (Type t2 : ts.tail) {
3618 if (t1.isErroneous())
3619 return t1;
3620 t1 = glb(t1, t2);
3621 }
3622 return t1;
3623 }
3624 //where
3625 public Type glb(Type t, Type s) {
3626 if (s == null)
3627 return t;
3628 else if (t.isPrimitive() || s.isPrimitive())
3629 return syms.errType;
3630 else if (isSubtypeNoCapture(t, s))
3631 return t;
3632 else if (isSubtypeNoCapture(s, t))
3633 return s;
3635 List<Type> closure = union(closure(t), closure(s));
3636 List<Type> bounds = closureMin(closure);
3638 if (bounds.isEmpty()) { // length == 0
3639 return syms.objectType;
3640 } else if (bounds.tail.isEmpty()) { // length == 1
3641 return bounds.head;
3642 } else { // length > 1
3643 int classCount = 0;
3644 for (Type bound : bounds)
3645 if (!bound.isInterface())
3646 classCount++;
3647 if (classCount > 1)
3648 return createErrorType(t);
3649 }
3650 return makeCompoundType(bounds);
3651 }
3652 // </editor-fold>
3654 // <editor-fold defaultstate="collapsed" desc="hashCode">
3655 /**
3656 * Compute a hash code on a type.
3657 */
3658 public int hashCode(Type t) {
3659 return hashCode.visit(t);
3660 }
3661 // where
3662 private static final UnaryVisitor<Integer> hashCode = new UnaryVisitor<Integer>() {
3664 public Integer visitType(Type t, Void ignored) {
3665 return t.getTag().ordinal();
3666 }
3668 @Override
3669 public Integer visitClassType(ClassType t, Void ignored) {
3670 int result = visit(t.getEnclosingType());
3671 result *= 127;
3672 result += t.tsym.flatName().hashCode();
3673 for (Type s : t.getTypeArguments()) {
3674 result *= 127;
3675 result += visit(s);
3676 }
3677 return result;
3678 }
3680 @Override
3681 public Integer visitMethodType(MethodType t, Void ignored) {
3682 int h = METHOD.ordinal();
3683 for (List<Type> thisargs = t.argtypes;
3684 thisargs.tail != null;
3685 thisargs = thisargs.tail)
3686 h = (h << 5) + visit(thisargs.head);
3687 return (h << 5) + visit(t.restype);
3688 }
3690 @Override
3691 public Integer visitWildcardType(WildcardType t, Void ignored) {
3692 int result = t.kind.hashCode();
3693 if (t.type != null) {
3694 result *= 127;
3695 result += visit(t.type);
3696 }
3697 return result;
3698 }
3700 @Override
3701 public Integer visitArrayType(ArrayType t, Void ignored) {
3702 return visit(t.elemtype) + 12;
3703 }
3705 @Override
3706 public Integer visitTypeVar(TypeVar t, Void ignored) {
3707 return System.identityHashCode(t.tsym);
3708 }
3710 @Override
3711 public Integer visitUndetVar(UndetVar t, Void ignored) {
3712 return System.identityHashCode(t);
3713 }
3715 @Override
3716 public Integer visitErrorType(ErrorType t, Void ignored) {
3717 return 0;
3718 }
3719 };
3720 // </editor-fold>
3722 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable">
3723 /**
3724 * Does t have a result that is a subtype of the result type of s,
3725 * suitable for covariant returns? It is assumed that both types
3726 * are (possibly polymorphic) method types. Monomorphic method
3727 * types are handled in the obvious way. Polymorphic method types
3728 * require renaming all type variables of one to corresponding
3729 * type variables in the other, where correspondence is by
3730 * position in the type parameter list. */
3731 public boolean resultSubtype(Type t, Type s, Warner warner) {
3732 List<Type> tvars = t.getTypeArguments();
3733 List<Type> svars = s.getTypeArguments();
3734 Type tres = t.getReturnType();
3735 Type sres = subst(s.getReturnType(), svars, tvars);
3736 return covariantReturnType(tres, sres, warner);
3737 }
3739 /**
3740 * Return-Type-Substitutable.
3741 * @jls section 8.4.5
3742 */
3743 public boolean returnTypeSubstitutable(Type r1, Type r2) {
3744 if (hasSameArgs(r1, r2))
3745 return resultSubtype(r1, r2, noWarnings);
3746 else
3747 return covariantReturnType(r1.getReturnType(),
3748 erasure(r2.getReturnType()),
3749 noWarnings);
3750 }
3752 public boolean returnTypeSubstitutable(Type r1,
3753 Type r2, Type r2res,
3754 Warner warner) {
3755 if (isSameType(r1.getReturnType(), r2res))
3756 return true;
3757 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive())
3758 return false;
3760 if (hasSameArgs(r1, r2))
3761 return covariantReturnType(r1.getReturnType(), r2res, warner);
3762 if (!allowCovariantReturns)
3763 return false;
3764 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner))
3765 return true;
3766 if (!isSubtype(r1.getReturnType(), erasure(r2res)))
3767 return false;
3768 warner.warn(LintCategory.UNCHECKED);
3769 return true;
3770 }
3772 /**
3773 * Is t an appropriate return type in an overrider for a
3774 * method that returns s?
3775 */
3776 public boolean covariantReturnType(Type t, Type s, Warner warner) {
3777 return
3778 isSameType(t, s) ||
3779 allowCovariantReturns &&
3780 !t.isPrimitive() &&
3781 !s.isPrimitive() &&
3782 isAssignable(t, s, warner);
3783 }
3784 // </editor-fold>
3786 // <editor-fold defaultstate="collapsed" desc="Box/unbox support">
3787 /**
3788 * Return the class that boxes the given primitive.
3789 */
3790 public ClassSymbol boxedClass(Type t) {
3791 return reader.enterClass(syms.boxedName[t.getTag().ordinal()]);
3792 }
3794 /**
3795 * Return the boxed type if 't' is primitive, otherwise return 't' itself.
3796 */
3797 public Type boxedTypeOrType(Type t) {
3798 return t.isPrimitive() ?
3799 boxedClass(t).type :
3800 t;
3801 }
3803 /**
3804 * Return the primitive type corresponding to a boxed type.
3805 */
3806 public Type unboxedType(Type t) {
3807 if (allowBoxing) {
3808 for (int i=0; i<syms.boxedName.length; i++) {
3809 Name box = syms.boxedName[i];
3810 if (box != null &&
3811 asSuper(t, reader.enterClass(box)) != null)
3812 return syms.typeOfTag[i];
3813 }
3814 }
3815 return Type.noType;
3816 }
3818 /**
3819 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself.
3820 */
3821 public Type unboxedTypeOrType(Type t) {
3822 Type unboxedType = unboxedType(t);
3823 return unboxedType.hasTag(NONE) ? t : unboxedType;
3824 }
3825 // </editor-fold>
3827 // <editor-fold defaultstate="collapsed" desc="Capture conversion">
3828 /*
3829 * JLS 5.1.10 Capture Conversion:
3830 *
3831 * Let G name a generic type declaration with n formal type
3832 * parameters A1 ... An with corresponding bounds U1 ... Un. There
3833 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>,
3834 * where, for 1 <= i <= n:
3835 *
3836 * + If Ti is a wildcard type argument (4.5.1) of the form ? then
3837 * Si is a fresh type variable whose upper bound is
3838 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null
3839 * type.
3840 *
3841 * + If Ti is a wildcard type argument of the form ? extends Bi,
3842 * then Si is a fresh type variable whose upper bound is
3843 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is
3844 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is
3845 * a compile-time error if for any two classes (not interfaces)
3846 * Vi and Vj,Vi is not a subclass of Vj or vice versa.
3847 *
3848 * + If Ti is a wildcard type argument of the form ? super Bi,
3849 * then Si is a fresh type variable whose upper bound is
3850 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi.
3851 *
3852 * + Otherwise, Si = Ti.
3853 *
3854 * Capture conversion on any type other than a parameterized type
3855 * (4.5) acts as an identity conversion (5.1.1). Capture
3856 * conversions never require a special action at run time and
3857 * therefore never throw an exception at run time.
3858 *
3859 * Capture conversion is not applied recursively.
3860 */
3861 /**
3862 * Capture conversion as specified by the JLS.
3863 */
3865 public List<Type> capture(List<Type> ts) {
3866 List<Type> buf = List.nil();
3867 for (Type t : ts) {
3868 buf = buf.prepend(capture(t));
3869 }
3870 return buf.reverse();
3871 }
3872 public Type capture(Type t) {
3873 if (!t.hasTag(CLASS))
3874 return t;
3875 if (t.getEnclosingType() != Type.noType) {
3876 Type capturedEncl = capture(t.getEnclosingType());
3877 if (capturedEncl != t.getEnclosingType()) {
3878 Type type1 = memberType(capturedEncl, t.tsym);
3879 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments());
3880 }
3881 }
3882 t = t.unannotatedType();
3883 ClassType cls = (ClassType)t;
3884 if (cls.isRaw() || !cls.isParameterized())
3885 return cls;
3887 ClassType G = (ClassType)cls.asElement().asType();
3888 List<Type> A = G.getTypeArguments();
3889 List<Type> T = cls.getTypeArguments();
3890 List<Type> S = freshTypeVariables(T);
3892 List<Type> currentA = A;
3893 List<Type> currentT = T;
3894 List<Type> currentS = S;
3895 boolean captured = false;
3896 while (!currentA.isEmpty() &&
3897 !currentT.isEmpty() &&
3898 !currentS.isEmpty()) {
3899 if (currentS.head != currentT.head) {
3900 captured = true;
3901 WildcardType Ti = (WildcardType)currentT.head.unannotatedType();
3902 Type Ui = currentA.head.getUpperBound();
3903 CapturedType Si = (CapturedType)currentS.head.unannotatedType();
3904 if (Ui == null)
3905 Ui = syms.objectType;
3906 switch (Ti.kind) {
3907 case UNBOUND:
3908 Si.bound = subst(Ui, A, S);
3909 Si.lower = syms.botType;
3910 break;
3911 case EXTENDS:
3912 Si.bound = glb(Ti.getExtendsBound(), subst(Ui, A, S));
3913 Si.lower = syms.botType;
3914 break;
3915 case SUPER:
3916 Si.bound = subst(Ui, A, S);
3917 Si.lower = Ti.getSuperBound();
3918 break;
3919 }
3920 if (Si.bound == Si.lower)
3921 currentS.head = Si.bound;
3922 }
3923 currentA = currentA.tail;
3924 currentT = currentT.tail;
3925 currentS = currentS.tail;
3926 }
3927 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty())
3928 return erasure(t); // some "rare" type involved
3930 if (captured)
3931 return new ClassType(cls.getEnclosingType(), S, cls.tsym);
3932 else
3933 return t;
3934 }
3935 // where
3936 public List<Type> freshTypeVariables(List<Type> types) {
3937 ListBuffer<Type> result = new ListBuffer<>();
3938 for (Type t : types) {
3939 if (t.hasTag(WILDCARD)) {
3940 t = t.unannotatedType();
3941 Type bound = ((WildcardType)t).getExtendsBound();
3942 if (bound == null)
3943 bound = syms.objectType;
3944 result.append(new CapturedType(capturedName,
3945 syms.noSymbol,
3946 bound,
3947 syms.botType,
3948 (WildcardType)t));
3949 } else {
3950 result.append(t);
3951 }
3952 }
3953 return result.toList();
3954 }
3955 // </editor-fold>
3957 // <editor-fold defaultstate="collapsed" desc="Internal utility methods">
3958 private List<Type> upperBounds(List<Type> ss) {
3959 if (ss.isEmpty()) return ss;
3960 Type head = upperBound(ss.head);
3961 List<Type> tail = upperBounds(ss.tail);
3962 if (head != ss.head || tail != ss.tail)
3963 return tail.prepend(head);
3964 else
3965 return ss;
3966 }
3968 private boolean sideCast(Type from, Type to, Warner warn) {
3969 // We are casting from type $from$ to type $to$, which are
3970 // non-final unrelated types. This method
3971 // tries to reject a cast by transferring type parameters
3972 // from $to$ to $from$ by common superinterfaces.
3973 boolean reverse = false;
3974 Type target = to;
3975 if ((to.tsym.flags() & INTERFACE) == 0) {
3976 Assert.check((from.tsym.flags() & INTERFACE) != 0);
3977 reverse = true;
3978 to = from;
3979 from = target;
3980 }
3981 List<Type> commonSupers = superClosure(to, erasure(from));
3982 boolean giveWarning = commonSupers.isEmpty();
3983 // The arguments to the supers could be unified here to
3984 // get a more accurate analysis
3985 while (commonSupers.nonEmpty()) {
3986 Type t1 = asSuper(from, commonSupers.head.tsym);
3987 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym);
3988 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
3989 return false;
3990 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2));
3991 commonSupers = commonSupers.tail;
3992 }
3993 if (giveWarning && !isReifiable(reverse ? from : to))
3994 warn.warn(LintCategory.UNCHECKED);
3995 if (!allowCovariantReturns)
3996 // reject if there is a common method signature with
3997 // incompatible return types.
3998 chk.checkCompatibleAbstracts(warn.pos(), from, to);
3999 return true;
4000 }
4002 private boolean sideCastFinal(Type from, Type to, Warner warn) {
4003 // We are casting from type $from$ to type $to$, which are
4004 // unrelated types one of which is final and the other of
4005 // which is an interface. This method
4006 // tries to reject a cast by transferring type parameters
4007 // from the final class to the interface.
4008 boolean reverse = false;
4009 Type target = to;
4010 if ((to.tsym.flags() & INTERFACE) == 0) {
4011 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4012 reverse = true;
4013 to = from;
4014 from = target;
4015 }
4016 Assert.check((from.tsym.flags() & FINAL) != 0);
4017 Type t1 = asSuper(from, to.tsym);
4018 if (t1 == null) return false;
4019 Type t2 = to;
4020 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4021 return false;
4022 if (!allowCovariantReturns)
4023 // reject if there is a common method signature with
4024 // incompatible return types.
4025 chk.checkCompatibleAbstracts(warn.pos(), from, to);
4026 if (!isReifiable(target) &&
4027 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)))
4028 warn.warn(LintCategory.UNCHECKED);
4029 return true;
4030 }
4032 private boolean giveWarning(Type from, Type to) {
4033 List<Type> bounds = to.isCompound() ?
4034 ((IntersectionClassType)to.unannotatedType()).getComponents() : List.of(to);
4035 for (Type b : bounds) {
4036 Type subFrom = asSub(from, b.tsym);
4037 if (b.isParameterized() &&
4038 (!(isUnbounded(b) ||
4039 isSubtype(from, b) ||
4040 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) {
4041 return true;
4042 }
4043 }
4044 return false;
4045 }
4047 private List<Type> superClosure(Type t, Type s) {
4048 List<Type> cl = List.nil();
4049 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
4050 if (isSubtype(s, erasure(l.head))) {
4051 cl = insert(cl, l.head);
4052 } else {
4053 cl = union(cl, superClosure(l.head, s));
4054 }
4055 }
4056 return cl;
4057 }
4059 private boolean containsTypeEquivalent(Type t, Type s) {
4060 return
4061 isSameType(t, s) || // shortcut
4062 containsType(t, s) && containsType(s, t);
4063 }
4065 // <editor-fold defaultstate="collapsed" desc="adapt">
4066 /**
4067 * Adapt a type by computing a substitution which maps a source
4068 * type to a target type.
4069 *
4070 * @param source the source type
4071 * @param target the target type
4072 * @param from the type variables of the computed substitution
4073 * @param to the types of the computed substitution.
4074 */
4075 public void adapt(Type source,
4076 Type target,
4077 ListBuffer<Type> from,
4078 ListBuffer<Type> to) throws AdaptFailure {
4079 new Adapter(from, to).adapt(source, target);
4080 }
4082 class Adapter extends SimpleVisitor<Void, Type> {
4084 ListBuffer<Type> from;
4085 ListBuffer<Type> to;
4086 Map<Symbol,Type> mapping;
4088 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) {
4089 this.from = from;
4090 this.to = to;
4091 mapping = new HashMap<Symbol,Type>();
4092 }
4094 public void adapt(Type source, Type target) throws AdaptFailure {
4095 visit(source, target);
4096 List<Type> fromList = from.toList();
4097 List<Type> toList = to.toList();
4098 while (!fromList.isEmpty()) {
4099 Type val = mapping.get(fromList.head.tsym);
4100 if (toList.head != val)
4101 toList.head = val;
4102 fromList = fromList.tail;
4103 toList = toList.tail;
4104 }
4105 }
4107 @Override
4108 public Void visitClassType(ClassType source, Type target) throws AdaptFailure {
4109 if (target.hasTag(CLASS))
4110 adaptRecursive(source.allparams(), target.allparams());
4111 return null;
4112 }
4114 @Override
4115 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure {
4116 if (target.hasTag(ARRAY))
4117 adaptRecursive(elemtype(source), elemtype(target));
4118 return null;
4119 }
4121 @Override
4122 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure {
4123 if (source.isExtendsBound())
4124 adaptRecursive(upperBound(source), upperBound(target));
4125 else if (source.isSuperBound())
4126 adaptRecursive(lowerBound(source), lowerBound(target));
4127 return null;
4128 }
4130 @Override
4131 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure {
4132 // Check to see if there is
4133 // already a mapping for $source$, in which case
4134 // the old mapping will be merged with the new
4135 Type val = mapping.get(source.tsym);
4136 if (val != null) {
4137 if (val.isSuperBound() && target.isSuperBound()) {
4138 val = isSubtype(lowerBound(val), lowerBound(target))
4139 ? target : val;
4140 } else if (val.isExtendsBound() && target.isExtendsBound()) {
4141 val = isSubtype(upperBound(val), upperBound(target))
4142 ? val : target;
4143 } else if (!isSameType(val, target)) {
4144 throw new AdaptFailure();
4145 }
4146 } else {
4147 val = target;
4148 from.append(source);
4149 to.append(target);
4150 }
4151 mapping.put(source.tsym, val);
4152 return null;
4153 }
4155 @Override
4156 public Void visitType(Type source, Type target) {
4157 return null;
4158 }
4160 private Set<TypePair> cache = new HashSet<TypePair>();
4162 private void adaptRecursive(Type source, Type target) {
4163 TypePair pair = new TypePair(source, target);
4164 if (cache.add(pair)) {
4165 try {
4166 visit(source, target);
4167 } finally {
4168 cache.remove(pair);
4169 }
4170 }
4171 }
4173 private void adaptRecursive(List<Type> source, List<Type> target) {
4174 if (source.length() == target.length()) {
4175 while (source.nonEmpty()) {
4176 adaptRecursive(source.head, target.head);
4177 source = source.tail;
4178 target = target.tail;
4179 }
4180 }
4181 }
4182 }
4184 public static class AdaptFailure extends RuntimeException {
4185 static final long serialVersionUID = -7490231548272701566L;
4186 }
4188 private void adaptSelf(Type t,
4189 ListBuffer<Type> from,
4190 ListBuffer<Type> to) {
4191 try {
4192 //if (t.tsym.type != t)
4193 adapt(t.tsym.type, t, from, to);
4194 } catch (AdaptFailure ex) {
4195 // Adapt should never fail calculating a mapping from
4196 // t.tsym.type to t as there can be no merge problem.
4197 throw new AssertionError(ex);
4198 }
4199 }
4200 // </editor-fold>
4202 /**
4203 * Rewrite all type variables (universal quantifiers) in the given
4204 * type to wildcards (existential quantifiers). This is used to
4205 * determine if a cast is allowed. For example, if high is true
4206 * and {@code T <: Number}, then {@code List<T>} is rewritten to
4207 * {@code List<? extends Number>}. Since {@code List<Integer> <:
4208 * List<? extends Number>} a {@code List<T>} can be cast to {@code
4209 * List<Integer>} with a warning.
4210 * @param t a type
4211 * @param high if true return an upper bound; otherwise a lower
4212 * bound
4213 * @param rewriteTypeVars only rewrite captured wildcards if false;
4214 * otherwise rewrite all type variables
4215 * @return the type rewritten with wildcards (existential
4216 * quantifiers) only
4217 */
4218 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) {
4219 return new Rewriter(high, rewriteTypeVars).visit(t);
4220 }
4222 class Rewriter extends UnaryVisitor<Type> {
4224 boolean high;
4225 boolean rewriteTypeVars;
4227 Rewriter(boolean high, boolean rewriteTypeVars) {
4228 this.high = high;
4229 this.rewriteTypeVars = rewriteTypeVars;
4230 }
4232 @Override
4233 public Type visitClassType(ClassType t, Void s) {
4234 ListBuffer<Type> rewritten = new ListBuffer<Type>();
4235 boolean changed = false;
4236 for (Type arg : t.allparams()) {
4237 Type bound = visit(arg);
4238 if (arg != bound) {
4239 changed = true;
4240 }
4241 rewritten.append(bound);
4242 }
4243 if (changed)
4244 return subst(t.tsym.type,
4245 t.tsym.type.allparams(),
4246 rewritten.toList());
4247 else
4248 return t;
4249 }
4251 public Type visitType(Type t, Void s) {
4252 return high ? upperBound(t) : lowerBound(t);
4253 }
4255 @Override
4256 public Type visitCapturedType(CapturedType t, Void s) {
4257 Type w_bound = t.wildcard.type;
4258 Type bound = w_bound.contains(t) ?
4259 erasure(w_bound) :
4260 visit(w_bound);
4261 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind);
4262 }
4264 @Override
4265 public Type visitTypeVar(TypeVar t, Void s) {
4266 if (rewriteTypeVars) {
4267 Type bound = t.bound.contains(t) ?
4268 erasure(t.bound) :
4269 visit(t.bound);
4270 return rewriteAsWildcardType(bound, t, EXTENDS);
4271 } else {
4272 return t;
4273 }
4274 }
4276 @Override
4277 public Type visitWildcardType(WildcardType t, Void s) {
4278 Type bound2 = visit(t.type);
4279 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind);
4280 }
4282 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) {
4283 switch (bk) {
4284 case EXTENDS: return high ?
4285 makeExtendsWildcard(B(bound), formal) :
4286 makeExtendsWildcard(syms.objectType, formal);
4287 case SUPER: return high ?
4288 makeSuperWildcard(syms.botType, formal) :
4289 makeSuperWildcard(B(bound), formal);
4290 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal);
4291 default:
4292 Assert.error("Invalid bound kind " + bk);
4293 return null;
4294 }
4295 }
4297 Type B(Type t) {
4298 while (t.hasTag(WILDCARD)) {
4299 WildcardType w = (WildcardType)t.unannotatedType();
4300 t = high ?
4301 w.getExtendsBound() :
4302 w.getSuperBound();
4303 if (t == null) {
4304 t = high ? syms.objectType : syms.botType;
4305 }
4306 }
4307 return t;
4308 }
4309 }
4312 /**
4313 * Create a wildcard with the given upper (extends) bound; create
4314 * an unbounded wildcard if bound is Object.
4315 *
4316 * @param bound the upper bound
4317 * @param formal the formal type parameter that will be
4318 * substituted by the wildcard
4319 */
4320 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) {
4321 if (bound == syms.objectType) {
4322 return new WildcardType(syms.objectType,
4323 BoundKind.UNBOUND,
4324 syms.boundClass,
4325 formal);
4326 } else {
4327 return new WildcardType(bound,
4328 BoundKind.EXTENDS,
4329 syms.boundClass,
4330 formal);
4331 }
4332 }
4334 /**
4335 * Create a wildcard with the given lower (super) bound; create an
4336 * unbounded wildcard if bound is bottom (type of {@code null}).
4337 *
4338 * @param bound the lower bound
4339 * @param formal the formal type parameter that will be
4340 * substituted by the wildcard
4341 */
4342 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) {
4343 if (bound.hasTag(BOT)) {
4344 return new WildcardType(syms.objectType,
4345 BoundKind.UNBOUND,
4346 syms.boundClass,
4347 formal);
4348 } else {
4349 return new WildcardType(bound,
4350 BoundKind.SUPER,
4351 syms.boundClass,
4352 formal);
4353 }
4354 }
4356 /**
4357 * A wrapper for a type that allows use in sets.
4358 */
4359 public static class UniqueType {
4360 public final Type type;
4361 final Types types;
4363 public UniqueType(Type type, Types types) {
4364 this.type = type;
4365 this.types = types;
4366 }
4368 public int hashCode() {
4369 return types.hashCode(type);
4370 }
4372 public boolean equals(Object obj) {
4373 return (obj instanceof UniqueType) &&
4374 types.isSameAnnotatedType(type, ((UniqueType)obj).type);
4375 }
4377 public String toString() {
4378 return type.toString();
4379 }
4381 }
4382 // </editor-fold>
4384 // <editor-fold defaultstate="collapsed" desc="Visitors">
4385 /**
4386 * A default visitor for types. All visitor methods except
4387 * visitType are implemented by delegating to visitType. Concrete
4388 * subclasses must provide an implementation of visitType and can
4389 * override other methods as needed.
4390 *
4391 * @param <R> the return type of the operation implemented by this
4392 * visitor; use Void if no return type is needed.
4393 * @param <S> the type of the second argument (the first being the
4394 * type itself) of the operation implemented by this visitor; use
4395 * Void if a second argument is not needed.
4396 */
4397 public static abstract class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> {
4398 final public R visit(Type t, S s) { return t.accept(this, s); }
4399 public R visitClassType(ClassType t, S s) { return visitType(t, s); }
4400 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); }
4401 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); }
4402 public R visitMethodType(MethodType t, S s) { return visitType(t, s); }
4403 public R visitPackageType(PackageType t, S s) { return visitType(t, s); }
4404 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); }
4405 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); }
4406 public R visitForAll(ForAll t, S s) { return visitType(t, s); }
4407 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); }
4408 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); }
4409 // Pretend annotations don't exist
4410 public R visitAnnotatedType(AnnotatedType t, S s) { return visit(t.unannotatedType(), s); }
4411 }
4413 /**
4414 * A default visitor for symbols. All visitor methods except
4415 * visitSymbol are implemented by delegating to visitSymbol. Concrete
4416 * subclasses must provide an implementation of visitSymbol and can
4417 * override other methods as needed.
4418 *
4419 * @param <R> the return type of the operation implemented by this
4420 * visitor; use Void if no return type is needed.
4421 * @param <S> the type of the second argument (the first being the
4422 * symbol itself) of the operation implemented by this visitor; use
4423 * Void if a second argument is not needed.
4424 */
4425 public static abstract class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> {
4426 final public R visit(Symbol s, S arg) { return s.accept(this, arg); }
4427 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); }
4428 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); }
4429 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); }
4430 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); }
4431 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); }
4432 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); }
4433 }
4435 /**
4436 * A <em>simple</em> visitor for types. This visitor is simple as
4437 * captured wildcards, for-all types (generic methods), and
4438 * undetermined type variables (part of inference) are hidden.
4439 * Captured wildcards are hidden by treating them as type
4440 * variables and the rest are hidden by visiting their qtypes.
4441 *
4442 * @param <R> the return type of the operation implemented by this
4443 * visitor; use Void if no return type is needed.
4444 * @param <S> the type of the second argument (the first being the
4445 * type itself) of the operation implemented by this visitor; use
4446 * Void if a second argument is not needed.
4447 */
4448 public static abstract class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> {
4449 @Override
4450 public R visitCapturedType(CapturedType t, S s) {
4451 return visitTypeVar(t, s);
4452 }
4453 @Override
4454 public R visitForAll(ForAll t, S s) {
4455 return visit(t.qtype, s);
4456 }
4457 @Override
4458 public R visitUndetVar(UndetVar t, S s) {
4459 return visit(t.qtype, s);
4460 }
4461 }
4463 /**
4464 * A plain relation on types. That is a 2-ary function on the
4465 * form Type × Type → Boolean.
4466 * <!-- In plain text: Type x Type -> Boolean -->
4467 */
4468 public static abstract class TypeRelation extends SimpleVisitor<Boolean,Type> {}
4470 /**
4471 * A convenience visitor for implementing operations that only
4472 * require one argument (the type itself), that is, unary
4473 * operations.
4474 *
4475 * @param <R> the return type of the operation implemented by this
4476 * visitor; use Void if no return type is needed.
4477 */
4478 public static abstract class UnaryVisitor<R> extends SimpleVisitor<R,Void> {
4479 final public R visit(Type t) { return t.accept(this, null); }
4480 }
4482 /**
4483 * A visitor for implementing a mapping from types to types. The
4484 * default behavior of this class is to implement the identity
4485 * mapping (mapping a type to itself). This can be overridden in
4486 * subclasses.
4487 *
4488 * @param <S> the type of the second argument (the first being the
4489 * type itself) of this mapping; use Void if a second argument is
4490 * not needed.
4491 */
4492 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> {
4493 final public Type visit(Type t) { return t.accept(this, null); }
4494 public Type visitType(Type t, S s) { return t; }
4495 }
4496 // </editor-fold>
4499 // <editor-fold defaultstate="collapsed" desc="Annotation support">
4501 public RetentionPolicy getRetention(Attribute.Compound a) {
4502 return getRetention(a.type.tsym);
4503 }
4505 public RetentionPolicy getRetention(Symbol sym) {
4506 RetentionPolicy vis = RetentionPolicy.CLASS; // the default
4507 Attribute.Compound c = sym.attribute(syms.retentionType.tsym);
4508 if (c != null) {
4509 Attribute value = c.member(names.value);
4510 if (value != null && value instanceof Attribute.Enum) {
4511 Name levelName = ((Attribute.Enum)value).value.name;
4512 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE;
4513 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS;
4514 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME;
4515 else ;// /* fail soft */ throw new AssertionError(levelName);
4516 }
4517 }
4518 return vis;
4519 }
4520 // </editor-fold>
4522 // <editor-fold defaultstate="collapsed" desc="Signature Generation">
4524 public static abstract class SignatureGenerator {
4526 private final Types types;
4528 protected abstract void append(char ch);
4529 protected abstract void append(byte[] ba);
4530 protected abstract void append(Name name);
4531 protected void classReference(ClassSymbol c) { /* by default: no-op */ }
4533 protected SignatureGenerator(Types types) {
4534 this.types = types;
4535 }
4537 /**
4538 * Assemble signature of given type in string buffer.
4539 */
4540 public void assembleSig(Type type) {
4541 type = type.unannotatedType();
4542 switch (type.getTag()) {
4543 case BYTE:
4544 append('B');
4545 break;
4546 case SHORT:
4547 append('S');
4548 break;
4549 case CHAR:
4550 append('C');
4551 break;
4552 case INT:
4553 append('I');
4554 break;
4555 case LONG:
4556 append('J');
4557 break;
4558 case FLOAT:
4559 append('F');
4560 break;
4561 case DOUBLE:
4562 append('D');
4563 break;
4564 case BOOLEAN:
4565 append('Z');
4566 break;
4567 case VOID:
4568 append('V');
4569 break;
4570 case CLASS:
4571 append('L');
4572 assembleClassSig(type);
4573 append(';');
4574 break;
4575 case ARRAY:
4576 ArrayType at = (ArrayType) type;
4577 append('[');
4578 assembleSig(at.elemtype);
4579 break;
4580 case METHOD:
4581 MethodType mt = (MethodType) type;
4582 append('(');
4583 assembleSig(mt.argtypes);
4584 append(')');
4585 assembleSig(mt.restype);
4586 if (hasTypeVar(mt.thrown)) {
4587 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) {
4588 append('^');
4589 assembleSig(l.head);
4590 }
4591 }
4592 break;
4593 case WILDCARD: {
4594 Type.WildcardType ta = (Type.WildcardType) type;
4595 switch (ta.kind) {
4596 case SUPER:
4597 append('-');
4598 assembleSig(ta.type);
4599 break;
4600 case EXTENDS:
4601 append('+');
4602 assembleSig(ta.type);
4603 break;
4604 case UNBOUND:
4605 append('*');
4606 break;
4607 default:
4608 throw new AssertionError(ta.kind);
4609 }
4610 break;
4611 }
4612 case TYPEVAR:
4613 append('T');
4614 append(type.tsym.name);
4615 append(';');
4616 break;
4617 case FORALL:
4618 Type.ForAll ft = (Type.ForAll) type;
4619 assembleParamsSig(ft.tvars);
4620 assembleSig(ft.qtype);
4621 break;
4622 default:
4623 throw new AssertionError("typeSig " + type.getTag());
4624 }
4625 }
4627 public boolean hasTypeVar(List<Type> l) {
4628 while (l.nonEmpty()) {
4629 if (l.head.hasTag(TypeTag.TYPEVAR)) {
4630 return true;
4631 }
4632 l = l.tail;
4633 }
4634 return false;
4635 }
4637 public void assembleClassSig(Type type) {
4638 type = type.unannotatedType();
4639 ClassType ct = (ClassType) type;
4640 ClassSymbol c = (ClassSymbol) ct.tsym;
4641 classReference(c);
4642 Type outer = ct.getEnclosingType();
4643 if (outer.allparams().nonEmpty()) {
4644 boolean rawOuter =
4645 c.owner.kind == Kinds.MTH || // either a local class
4646 c.name == types.names.empty; // or anonymous
4647 assembleClassSig(rawOuter
4648 ? types.erasure(outer)
4649 : outer);
4650 append('.');
4651 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname));
4652 append(rawOuter
4653 ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength())
4654 : c.name);
4655 } else {
4656 append(externalize(c.flatname));
4657 }
4658 if (ct.getTypeArguments().nonEmpty()) {
4659 append('<');
4660 assembleSig(ct.getTypeArguments());
4661 append('>');
4662 }
4663 }
4665 public void assembleParamsSig(List<Type> typarams) {
4666 append('<');
4667 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) {
4668 Type.TypeVar tvar = (Type.TypeVar) ts.head;
4669 append(tvar.tsym.name);
4670 List<Type> bounds = types.getBounds(tvar);
4671 if ((bounds.head.tsym.flags() & INTERFACE) != 0) {
4672 append(':');
4673 }
4674 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) {
4675 append(':');
4676 assembleSig(l.head);
4677 }
4678 }
4679 append('>');
4680 }
4682 private void assembleSig(List<Type> types) {
4683 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) {
4684 assembleSig(ts.head);
4685 }
4686 }
4687 }
4688 // </editor-fold>
4689 }
