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src/share/classes/com/sun/tools/javac/code/Types.java@b0c086cd4520
src/share/classes/com/sun/tools/javac/code/Types.java
Tue, 15 Oct 2013 15:57:13 -0700
- author
- jjg
- date
- Tue, 15 Oct 2013 15:57:13 -0700
- changeset 2134
- b0c086cd4520
- parent 2079
- de1c5dbe6c28
- child 2187
- 4788eb38cac5
- permissions
- -rw-r--r--
8026564: import changes from type-annotations forest
Reviewed-by: jjg
Contributed-by: wdietl@gmail.com, steve.sides@oracle.com
1 /*
2 * Copyright (c) 2003, 2013, 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 boolean allowDefaultMethods;
88 final ClassReader reader;
89 final Check chk;
90 final Enter enter;
91 JCDiagnostic.Factory diags;
92 List<Warner> warnStack = List.nil();
93 final Name capturedName;
94 private final FunctionDescriptorLookupError functionDescriptorLookupError;
96 public final Warner noWarnings;
98 // <editor-fold defaultstate="collapsed" desc="Instantiating">
99 public static Types instance(Context context) {
100 Types instance = context.get(typesKey);
101 if (instance == null)
102 instance = new Types(context);
103 return instance;
104 }
106 protected Types(Context context) {
107 context.put(typesKey, this);
108 syms = Symtab.instance(context);
109 names = Names.instance(context);
110 Source source = Source.instance(context);
111 allowBoxing = source.allowBoxing();
112 allowCovariantReturns = source.allowCovariantReturns();
113 allowObjectToPrimitiveCast = source.allowObjectToPrimitiveCast();
114 allowDefaultMethods = source.allowDefaultMethods();
115 reader = ClassReader.instance(context);
116 chk = Check.instance(context);
117 enter = Enter.instance(context);
118 capturedName = names.fromString("<captured wildcard>");
119 messages = JavacMessages.instance(context);
120 diags = JCDiagnostic.Factory.instance(context);
121 functionDescriptorLookupError = new FunctionDescriptorLookupError();
122 noWarnings = new Warner(null);
123 }
124 // </editor-fold>
126 // <editor-fold defaultstate="collapsed" desc="upperBound">
127 /**
128 * The "rvalue conversion".<br>
129 * The upper bound of most types is the type
130 * itself. Wildcards, on the other hand have upper
131 * and lower bounds.
132 * @param t a type
133 * @return the upper bound of the given type
134 */
135 public Type upperBound(Type t) {
136 return upperBound.visit(t).unannotatedType();
137 }
138 // where
139 private final MapVisitor<Void> upperBound = new MapVisitor<Void>() {
141 @Override
142 public Type visitWildcardType(WildcardType t, Void ignored) {
143 if (t.isSuperBound())
144 return t.bound == null ? syms.objectType : t.bound.bound;
145 else
146 return visit(t.type);
147 }
149 @Override
150 public Type visitCapturedType(CapturedType t, Void ignored) {
151 return visit(t.bound);
152 }
153 };
154 // </editor-fold>
156 // <editor-fold defaultstate="collapsed" desc="lowerBound">
157 /**
158 * The "lvalue conversion".<br>
159 * The lower bound of most types is the type
160 * itself. Wildcards, on the other hand have upper
161 * and lower bounds.
162 * @param t a type
163 * @return the lower bound of the given type
164 */
165 public Type lowerBound(Type t) {
166 return lowerBound.visit(t);
167 }
168 // where
169 private final MapVisitor<Void> lowerBound = new MapVisitor<Void>() {
171 @Override
172 public Type visitWildcardType(WildcardType t, Void ignored) {
173 return t.isExtendsBound() ? syms.botType : visit(t.type);
174 }
176 @Override
177 public Type visitCapturedType(CapturedType t, Void ignored) {
178 return visit(t.getLowerBound());
179 }
180 };
181 // </editor-fold>
183 // <editor-fold defaultstate="collapsed" desc="isUnbounded">
184 /**
185 * Checks that all the arguments to a class are unbounded
186 * wildcards or something else that doesn't make any restrictions
187 * on the arguments. If a class isUnbounded, a raw super- or
188 * subclass can be cast to it without a warning.
189 * @param t a type
190 * @return true iff the given type is unbounded or raw
191 */
192 public boolean isUnbounded(Type t) {
193 return isUnbounded.visit(t);
194 }
195 // where
196 private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() {
198 public Boolean visitType(Type t, Void ignored) {
199 return true;
200 }
202 @Override
203 public Boolean visitClassType(ClassType t, Void ignored) {
204 List<Type> parms = t.tsym.type.allparams();
205 List<Type> args = t.allparams();
206 while (parms.nonEmpty()) {
207 WildcardType unb = new WildcardType(syms.objectType,
208 BoundKind.UNBOUND,
209 syms.boundClass,
210 (TypeVar)parms.head.unannotatedType());
211 if (!containsType(args.head, unb))
212 return false;
213 parms = parms.tail;
214 args = args.tail;
215 }
216 return true;
217 }
218 };
219 // </editor-fold>
221 // <editor-fold defaultstate="collapsed" desc="asSub">
222 /**
223 * Return the least specific subtype of t that starts with symbol
224 * sym. If none exists, return null. The least specific subtype
225 * is determined as follows:
226 *
227 * <p>If there is exactly one parameterized instance of sym that is a
228 * subtype of t, that parameterized instance is returned.<br>
229 * Otherwise, if the plain type or raw type `sym' is a subtype of
230 * type t, the type `sym' itself is returned. Otherwise, null is
231 * returned.
232 */
233 public Type asSub(Type t, Symbol sym) {
234 return asSub.visit(t, sym);
235 }
236 // where
237 private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() {
239 public Type visitType(Type t, Symbol sym) {
240 return null;
241 }
243 @Override
244 public Type visitClassType(ClassType t, Symbol sym) {
245 if (t.tsym == sym)
246 return t;
247 Type base = asSuper(sym.type, t);
248 if (base == null)
249 return null;
250 ListBuffer<Type> from = new ListBuffer<Type>();
251 ListBuffer<Type> to = new ListBuffer<Type>();
252 try {
253 adapt(base, t, from, to);
254 } catch (AdaptFailure ex) {
255 return null;
256 }
257 Type res = subst(sym.type, from.toList(), to.toList());
258 if (!isSubtype(res, t))
259 return null;
260 ListBuffer<Type> openVars = new ListBuffer<Type>();
261 for (List<Type> l = sym.type.allparams();
262 l.nonEmpty(); l = l.tail)
263 if (res.contains(l.head) && !t.contains(l.head))
264 openVars.append(l.head);
265 if (openVars.nonEmpty()) {
266 if (t.isRaw()) {
267 // The subtype of a raw type is raw
268 res = erasure(res);
269 } else {
270 // Unbound type arguments default to ?
271 List<Type> opens = openVars.toList();
272 ListBuffer<Type> qs = new ListBuffer<Type>();
273 for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) {
274 qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, syms.boundClass, (TypeVar) iter.head.unannotatedType()));
275 }
276 res = subst(res, opens, qs.toList());
277 }
278 }
279 return res;
280 }
282 @Override
283 public Type visitErrorType(ErrorType t, Symbol sym) {
284 return t;
285 }
286 };
287 // </editor-fold>
289 // <editor-fold defaultstate="collapsed" desc="isConvertible">
290 /**
291 * Is t a subtype of or convertible via boxing/unboxing
292 * conversion to s?
293 */
294 public boolean isConvertible(Type t, Type s, Warner warn) {
295 if (t.hasTag(ERROR)) {
296 return true;
297 }
298 boolean tPrimitive = t.isPrimitive();
299 boolean sPrimitive = s.isPrimitive();
300 if (tPrimitive == sPrimitive) {
301 return isSubtypeUnchecked(t, s, warn);
302 }
303 if (!allowBoxing) return false;
304 return tPrimitive
305 ? isSubtype(boxedClass(t).type, s)
306 : isSubtype(unboxedType(t), s);
307 }
309 /**
310 * Is t a subtype of or convertiable via boxing/unboxing
311 * convertions to s?
312 */
313 public boolean isConvertible(Type t, Type s) {
314 return isConvertible(t, s, noWarnings);
315 }
316 // </editor-fold>
318 // <editor-fold defaultstate="collapsed" desc="findSam">
320 /**
321 * Exception used to report a function descriptor lookup failure. The exception
322 * wraps a diagnostic that can be used to generate more details error
323 * messages.
324 */
325 public static class FunctionDescriptorLookupError extends RuntimeException {
326 private static final long serialVersionUID = 0;
328 JCDiagnostic diagnostic;
330 FunctionDescriptorLookupError() {
331 this.diagnostic = null;
332 }
334 FunctionDescriptorLookupError setMessage(JCDiagnostic diag) {
335 this.diagnostic = diag;
336 return this;
337 }
339 public JCDiagnostic getDiagnostic() {
340 return diagnostic;
341 }
342 }
344 /**
345 * A cache that keeps track of function descriptors associated with given
346 * functional interfaces.
347 */
348 class DescriptorCache {
350 private WeakHashMap<TypeSymbol, Entry> _map = new WeakHashMap<TypeSymbol, Entry>();
352 class FunctionDescriptor {
353 Symbol descSym;
355 FunctionDescriptor(Symbol descSym) {
356 this.descSym = descSym;
357 }
359 public Symbol getSymbol() {
360 return descSym;
361 }
363 public Type getType(Type site) {
364 site = removeWildcards(site);
365 if (!chk.checkValidGenericType(site)) {
366 //if the inferred functional interface type is not well-formed,
367 //or if it's not a subtype of the original target, issue an error
368 throw failure(diags.fragment("no.suitable.functional.intf.inst", site));
369 }
370 return memberType(site, descSym);
371 }
372 }
374 class Entry {
375 final FunctionDescriptor cachedDescRes;
376 final int prevMark;
378 public Entry(FunctionDescriptor cachedDescRes,
379 int prevMark) {
380 this.cachedDescRes = cachedDescRes;
381 this.prevMark = prevMark;
382 }
384 boolean matches(int mark) {
385 return this.prevMark == mark;
386 }
387 }
389 FunctionDescriptor get(TypeSymbol origin) throws FunctionDescriptorLookupError {
390 Entry e = _map.get(origin);
391 CompoundScope members = membersClosure(origin.type, false);
392 if (e == null ||
393 !e.matches(members.getMark())) {
394 FunctionDescriptor descRes = findDescriptorInternal(origin, members);
395 _map.put(origin, new Entry(descRes, members.getMark()));
396 return descRes;
397 }
398 else {
399 return e.cachedDescRes;
400 }
401 }
403 /**
404 * Compute the function descriptor associated with a given functional interface
405 */
406 public FunctionDescriptor findDescriptorInternal(TypeSymbol origin,
407 CompoundScope membersCache) throws FunctionDescriptorLookupError {
408 if (!origin.isInterface() || (origin.flags() & ANNOTATION) != 0) {
409 //t must be an interface
410 throw failure("not.a.functional.intf", origin);
411 }
413 final ListBuffer<Symbol> abstracts = new ListBuffer<>();
414 for (Symbol sym : membersCache.getElements(new DescriptorFilter(origin))) {
415 Type mtype = memberType(origin.type, sym);
416 if (abstracts.isEmpty() ||
417 (sym.name == abstracts.first().name &&
418 overrideEquivalent(mtype, memberType(origin.type, abstracts.first())))) {
419 abstracts.append(sym);
420 } else {
421 //the target method(s) should be the only abstract members of t
422 throw failure("not.a.functional.intf.1", origin,
423 diags.fragment("incompatible.abstracts", Kinds.kindName(origin), origin));
424 }
425 }
426 if (abstracts.isEmpty()) {
427 //t must define a suitable non-generic method
428 throw failure("not.a.functional.intf.1", origin,
429 diags.fragment("no.abstracts", Kinds.kindName(origin), origin));
430 } else if (abstracts.size() == 1) {
431 return new FunctionDescriptor(abstracts.first());
432 } else { // size > 1
433 FunctionDescriptor descRes = mergeDescriptors(origin, abstracts.toList());
434 if (descRes == null) {
435 //we can get here if the functional interface is ill-formed
436 ListBuffer<JCDiagnostic> descriptors = new ListBuffer<>();
437 for (Symbol desc : abstracts) {
438 String key = desc.type.getThrownTypes().nonEmpty() ?
439 "descriptor.throws" : "descriptor";
440 descriptors.append(diags.fragment(key, desc.name,
441 desc.type.getParameterTypes(),
442 desc.type.getReturnType(),
443 desc.type.getThrownTypes()));
444 }
445 JCDiagnostic.MultilineDiagnostic incompatibleDescriptors =
446 new JCDiagnostic.MultilineDiagnostic(diags.fragment("incompatible.descs.in.functional.intf",
447 Kinds.kindName(origin), origin), descriptors.toList());
448 throw failure(incompatibleDescriptors);
449 }
450 return descRes;
451 }
452 }
454 /**
455 * Compute a synthetic type for the target descriptor given a list
456 * of override-equivalent methods in the functional interface type.
457 * The resulting method type is a method type that is override-equivalent
458 * and return-type substitutable with each method in the original list.
459 */
460 private FunctionDescriptor mergeDescriptors(TypeSymbol origin, List<Symbol> methodSyms) {
461 //pick argument types - simply take the signature that is a
462 //subsignature of all other signatures in the list (as per JLS 8.4.2)
463 List<Symbol> mostSpecific = List.nil();
464 outer: for (Symbol msym1 : methodSyms) {
465 Type mt1 = memberType(origin.type, msym1);
466 for (Symbol msym2 : methodSyms) {
467 Type mt2 = memberType(origin.type, msym2);
468 if (!isSubSignature(mt1, mt2)) {
469 continue outer;
470 }
471 }
472 mostSpecific = mostSpecific.prepend(msym1);
473 }
474 if (mostSpecific.isEmpty()) {
475 return null;
476 }
479 //pick return types - this is done in two phases: (i) first, the most
480 //specific return type is chosen using strict subtyping; if this fails,
481 //a second attempt is made using return type substitutability (see JLS 8.4.5)
482 boolean phase2 = false;
483 Symbol bestSoFar = null;
484 while (bestSoFar == null) {
485 outer: for (Symbol msym1 : mostSpecific) {
486 Type mt1 = memberType(origin.type, msym1);
487 for (Symbol msym2 : methodSyms) {
488 Type mt2 = memberType(origin.type, msym2);
489 if (phase2 ?
490 !returnTypeSubstitutable(mt1, mt2) :
491 !isSubtypeInternal(mt1.getReturnType(), mt2.getReturnType())) {
492 continue outer;
493 }
494 }
495 bestSoFar = msym1;
496 }
497 if (phase2) {
498 break;
499 } else {
500 phase2 = true;
501 }
502 }
503 if (bestSoFar == null) return null;
505 //merge thrown types - form the intersection of all the thrown types in
506 //all the signatures in the list
507 boolean toErase = !bestSoFar.type.hasTag(FORALL);
508 List<Type> thrown = null;
509 Type mt1 = memberType(origin.type, bestSoFar);
510 for (Symbol msym2 : methodSyms) {
511 Type mt2 = memberType(origin.type, msym2);
512 List<Type> thrown_mt2 = mt2.getThrownTypes();
513 if (toErase) {
514 thrown_mt2 = erasure(thrown_mt2);
515 } else {
516 /* If bestSoFar is generic then all the methods are generic.
517 * The opposite is not true: a non generic method can override
518 * a generic method (raw override) so it's safe to cast mt1 and
519 * mt2 to ForAll.
520 */
521 ForAll fa1 = (ForAll)mt1;
522 ForAll fa2 = (ForAll)mt2;
523 thrown_mt2 = subst(thrown_mt2, fa2.tvars, fa1.tvars);
524 }
525 thrown = (thrown == null) ?
526 thrown_mt2 :
527 chk.intersect(thrown_mt2, thrown);
528 }
530 final List<Type> thrown1 = thrown;
531 return new FunctionDescriptor(bestSoFar) {
532 @Override
533 public Type getType(Type origin) {
534 Type mt = memberType(origin, getSymbol());
535 return createMethodTypeWithThrown(mt, thrown1);
536 }
537 };
538 }
540 boolean isSubtypeInternal(Type s, Type t) {
541 return (s.isPrimitive() && t.isPrimitive()) ?
542 isSameType(t, s) :
543 isSubtype(s, t);
544 }
546 FunctionDescriptorLookupError failure(String msg, Object... args) {
547 return failure(diags.fragment(msg, args));
548 }
550 FunctionDescriptorLookupError failure(JCDiagnostic diag) {
551 return functionDescriptorLookupError.setMessage(diag);
552 }
553 }
555 private DescriptorCache descCache = new DescriptorCache();
557 /**
558 * Find the method descriptor associated to this class symbol - if the
559 * symbol 'origin' is not a functional interface, an exception is thrown.
560 */
561 public Symbol findDescriptorSymbol(TypeSymbol origin) throws FunctionDescriptorLookupError {
562 return descCache.get(origin).getSymbol();
563 }
565 /**
566 * Find the type of the method descriptor associated to this class symbol -
567 * if the symbol 'origin' is not a functional interface, an exception is thrown.
568 */
569 public Type findDescriptorType(Type origin) throws FunctionDescriptorLookupError {
570 return descCache.get(origin.tsym).getType(origin);
571 }
573 /**
574 * Is given type a functional interface?
575 */
576 public boolean isFunctionalInterface(TypeSymbol tsym) {
577 try {
578 findDescriptorSymbol(tsym);
579 return true;
580 } catch (FunctionDescriptorLookupError ex) {
581 return false;
582 }
583 }
585 public boolean isFunctionalInterface(Type site) {
586 try {
587 findDescriptorType(site);
588 return true;
589 } catch (FunctionDescriptorLookupError ex) {
590 return false;
591 }
592 }
594 public Type removeWildcards(Type site) {
595 Type capturedSite = capture(site);
596 if (capturedSite != site) {
597 Type formalInterface = site.tsym.type;
598 ListBuffer<Type> typeargs = new ListBuffer<>();
599 List<Type> actualTypeargs = site.getTypeArguments();
600 List<Type> capturedTypeargs = capturedSite.getTypeArguments();
601 //simply replace the wildcards with its bound
602 for (Type t : formalInterface.getTypeArguments()) {
603 if (actualTypeargs.head.hasTag(WILDCARD)) {
604 WildcardType wt = (WildcardType)actualTypeargs.head.unannotatedType();
605 Type bound;
606 switch (wt.kind) {
607 case EXTENDS:
608 case UNBOUND:
609 CapturedType capVar = (CapturedType)capturedTypeargs.head.unannotatedType();
610 //use declared bound if it doesn't depend on formal type-args
611 bound = capVar.bound.containsAny(capturedSite.getTypeArguments()) ?
612 wt.type : capVar.bound;
613 break;
614 default:
615 bound = wt.type;
616 }
617 typeargs.append(bound);
618 } else {
619 typeargs.append(actualTypeargs.head);
620 }
621 actualTypeargs = actualTypeargs.tail;
622 capturedTypeargs = capturedTypeargs.tail;
623 }
624 return subst(formalInterface, formalInterface.getTypeArguments(), typeargs.toList());
625 } else {
626 return site;
627 }
628 }
630 /**
631 * Create a symbol for a class that implements a given functional interface
632 * and overrides its functional descriptor. This routine is used for two
633 * main purposes: (i) checking well-formedness of a functional interface;
634 * (ii) perform functional interface bridge calculation.
635 */
636 public ClassSymbol makeFunctionalInterfaceClass(Env<AttrContext> env, Name name, List<Type> targets, long cflags) {
637 if (targets.isEmpty() || !isFunctionalInterface(targets.head)) {
638 return null;
639 }
640 Symbol descSym = findDescriptorSymbol(targets.head.tsym);
641 Type descType = findDescriptorType(targets.head);
642 ClassSymbol csym = new ClassSymbol(cflags, name, env.enclClass.sym.outermostClass());
643 csym.completer = null;
644 csym.members_field = new Scope(csym);
645 MethodSymbol instDescSym = new MethodSymbol(descSym.flags(), descSym.name, descType, csym);
646 csym.members_field.enter(instDescSym);
647 Type.ClassType ctype = new Type.ClassType(Type.noType, List.<Type>nil(), csym);
648 ctype.supertype_field = syms.objectType;
649 ctype.interfaces_field = targets;
650 csym.type = ctype;
651 csym.sourcefile = ((ClassSymbol)csym.owner).sourcefile;
652 return csym;
653 }
655 /**
656 * Find the minimal set of methods that are overridden by the functional
657 * descriptor in 'origin'. All returned methods are assumed to have different
658 * erased signatures.
659 */
660 public List<Symbol> functionalInterfaceBridges(TypeSymbol origin) {
661 Assert.check(isFunctionalInterface(origin));
662 Symbol descSym = findDescriptorSymbol(origin);
663 CompoundScope members = membersClosure(origin.type, false);
664 ListBuffer<Symbol> overridden = new ListBuffer<>();
665 outer: for (Symbol m2 : members.getElementsByName(descSym.name, bridgeFilter)) {
666 if (m2 == descSym) continue;
667 else if (descSym.overrides(m2, origin, Types.this, false)) {
668 for (Symbol m3 : overridden) {
669 if (isSameType(m3.erasure(Types.this), m2.erasure(Types.this)) ||
670 (m3.overrides(m2, origin, Types.this, false) &&
671 (pendingBridges((ClassSymbol)origin, m3.enclClass()) ||
672 (((MethodSymbol)m2).binaryImplementation((ClassSymbol)m3.owner, Types.this) != null)))) {
673 continue outer;
674 }
675 }
676 overridden.add(m2);
677 }
678 }
679 return overridden.toList();
680 }
681 //where
682 private Filter<Symbol> bridgeFilter = new Filter<Symbol>() {
683 public boolean accepts(Symbol t) {
684 return t.kind == Kinds.MTH &&
685 t.name != names.init &&
686 t.name != names.clinit &&
687 (t.flags() & SYNTHETIC) == 0;
688 }
689 };
690 private boolean pendingBridges(ClassSymbol origin, TypeSymbol sym) {
691 //a symbol will be completed from a classfile if (a) symbol has
692 //an associated file object with CLASS kind and (b) the symbol has
693 //not been entered
694 if (origin.classfile != null &&
695 origin.classfile.getKind() == JavaFileObject.Kind.CLASS &&
696 enter.getEnv(origin) == null) {
697 return false;
698 }
699 if (origin == sym) {
700 return true;
701 }
702 for (Type t : interfaces(origin.type)) {
703 if (pendingBridges((ClassSymbol)t.tsym, sym)) {
704 return true;
705 }
706 }
707 return false;
708 }
709 // </editor-fold>
711 /**
712 * Scope filter used to skip methods that should be ignored (such as methods
713 * overridden by j.l.Object) during function interface conversion interface check
714 */
715 class DescriptorFilter implements Filter<Symbol> {
717 TypeSymbol origin;
719 DescriptorFilter(TypeSymbol origin) {
720 this.origin = origin;
721 }
723 @Override
724 public boolean accepts(Symbol sym) {
725 return sym.kind == Kinds.MTH &&
726 (sym.flags() & (ABSTRACT | DEFAULT)) == ABSTRACT &&
727 !overridesObjectMethod(origin, sym) &&
728 (interfaceCandidates(origin.type, (MethodSymbol)sym).head.flags() & DEFAULT) == 0;
729 }
730 };
732 // <editor-fold defaultstate="collapsed" desc="isSubtype">
733 /**
734 * Is t an unchecked subtype of s?
735 */
736 public boolean isSubtypeUnchecked(Type t, Type s) {
737 return isSubtypeUnchecked(t, s, noWarnings);
738 }
739 /**
740 * Is t an unchecked subtype of s?
741 */
742 public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) {
743 boolean result = isSubtypeUncheckedInternal(t, s, warn);
744 if (result) {
745 checkUnsafeVarargsConversion(t, s, warn);
746 }
747 return result;
748 }
749 //where
750 private boolean isSubtypeUncheckedInternal(Type t, Type s, Warner warn) {
751 if (t.hasTag(ARRAY) && s.hasTag(ARRAY)) {
752 t = t.unannotatedType();
753 s = s.unannotatedType();
754 if (((ArrayType)t).elemtype.isPrimitive()) {
755 return isSameType(elemtype(t), elemtype(s));
756 } else {
757 return isSubtypeUnchecked(elemtype(t), elemtype(s), warn);
758 }
759 } else if (isSubtype(t, s)) {
760 return true;
761 } else if (t.hasTag(TYPEVAR)) {
762 return isSubtypeUnchecked(t.getUpperBound(), s, warn);
763 } else if (!s.isRaw()) {
764 Type t2 = asSuper(t, s);
765 if (t2 != null && t2.isRaw()) {
766 if (isReifiable(s)) {
767 warn.silentWarn(LintCategory.UNCHECKED);
768 } else {
769 warn.warn(LintCategory.UNCHECKED);
770 }
771 return true;
772 }
773 }
774 return false;
775 }
777 private void checkUnsafeVarargsConversion(Type t, Type s, Warner warn) {
778 if (!t.hasTag(ARRAY) || isReifiable(t)) {
779 return;
780 }
781 t = t.unannotatedType();
782 s = s.unannotatedType();
783 ArrayType from = (ArrayType)t;
784 boolean shouldWarn = false;
785 switch (s.getTag()) {
786 case ARRAY:
787 ArrayType to = (ArrayType)s;
788 shouldWarn = from.isVarargs() &&
789 !to.isVarargs() &&
790 !isReifiable(from);
791 break;
792 case CLASS:
793 shouldWarn = from.isVarargs();
794 break;
795 }
796 if (shouldWarn) {
797 warn.warn(LintCategory.VARARGS);
798 }
799 }
801 /**
802 * Is t a subtype of s?<br>
803 * (not defined for Method and ForAll types)
804 */
805 final public boolean isSubtype(Type t, Type s) {
806 return isSubtype(t, s, true);
807 }
808 final public boolean isSubtypeNoCapture(Type t, Type s) {
809 return isSubtype(t, s, false);
810 }
811 public boolean isSubtype(Type t, Type s, boolean capture) {
812 if (t == s)
813 return true;
815 t = t.unannotatedType();
816 s = s.unannotatedType();
818 if (t == s)
819 return true;
821 if (s.isPartial())
822 return isSuperType(s, t);
824 if (s.isCompound()) {
825 for (Type s2 : interfaces(s).prepend(supertype(s))) {
826 if (!isSubtype(t, s2, capture))
827 return false;
828 }
829 return true;
830 }
832 Type lower = lowerBound(s);
833 if (s != lower)
834 return isSubtype(capture ? capture(t) : t, lower, false);
836 return isSubtype.visit(capture ? capture(t) : t, s);
837 }
838 // where
839 private TypeRelation isSubtype = new TypeRelation()
840 {
841 @Override
842 public Boolean visitType(Type t, Type s) {
843 switch (t.getTag()) {
844 case BYTE:
845 return (!s.hasTag(CHAR) && t.getTag().isSubRangeOf(s.getTag()));
846 case CHAR:
847 return (!s.hasTag(SHORT) && t.getTag().isSubRangeOf(s.getTag()));
848 case SHORT: case INT: case LONG:
849 case FLOAT: case DOUBLE:
850 return t.getTag().isSubRangeOf(s.getTag());
851 case BOOLEAN: case VOID:
852 return t.hasTag(s.getTag());
853 case TYPEVAR:
854 return isSubtypeNoCapture(t.getUpperBound(), s);
855 case BOT:
856 return
857 s.hasTag(BOT) || s.hasTag(CLASS) ||
858 s.hasTag(ARRAY) || s.hasTag(TYPEVAR);
859 case WILDCARD: //we shouldn't be here - avoids crash (see 7034495)
860 case NONE:
861 return false;
862 default:
863 throw new AssertionError("isSubtype " + t.getTag());
864 }
865 }
867 private Set<TypePair> cache = new HashSet<TypePair>();
869 private boolean containsTypeRecursive(Type t, Type s) {
870 TypePair pair = new TypePair(t, s);
871 if (cache.add(pair)) {
872 try {
873 return containsType(t.getTypeArguments(),
874 s.getTypeArguments());
875 } finally {
876 cache.remove(pair);
877 }
878 } else {
879 return containsType(t.getTypeArguments(),
880 rewriteSupers(s).getTypeArguments());
881 }
882 }
884 private Type rewriteSupers(Type t) {
885 if (!t.isParameterized())
886 return t;
887 ListBuffer<Type> from = new ListBuffer<>();
888 ListBuffer<Type> to = new ListBuffer<>();
889 adaptSelf(t, from, to);
890 if (from.isEmpty())
891 return t;
892 ListBuffer<Type> rewrite = new ListBuffer<>();
893 boolean changed = false;
894 for (Type orig : to.toList()) {
895 Type s = rewriteSupers(orig);
896 if (s.isSuperBound() && !s.isExtendsBound()) {
897 s = new WildcardType(syms.objectType,
898 BoundKind.UNBOUND,
899 syms.boundClass);
900 changed = true;
901 } else if (s != orig) {
902 s = new WildcardType(upperBound(s),
903 BoundKind.EXTENDS,
904 syms.boundClass);
905 changed = true;
906 }
907 rewrite.append(s);
908 }
909 if (changed)
910 return subst(t.tsym.type, from.toList(), rewrite.toList());
911 else
912 return t;
913 }
915 @Override
916 public Boolean visitClassType(ClassType t, Type s) {
917 Type sup = asSuper(t, s);
918 return sup != null
919 && sup.tsym == s.tsym
920 // You're not allowed to write
921 // Vector<Object> vec = new Vector<String>();
922 // But with wildcards you can write
923 // Vector<? extends Object> vec = new Vector<String>();
924 // which means that subtype checking must be done
925 // here instead of same-type checking (via containsType).
926 && (!s.isParameterized() || containsTypeRecursive(s, sup))
927 && isSubtypeNoCapture(sup.getEnclosingType(),
928 s.getEnclosingType());
929 }
931 @Override
932 public Boolean visitArrayType(ArrayType t, Type s) {
933 if (s.hasTag(ARRAY)) {
934 if (t.elemtype.isPrimitive())
935 return isSameType(t.elemtype, elemtype(s));
936 else
937 return isSubtypeNoCapture(t.elemtype, elemtype(s));
938 }
940 if (s.hasTag(CLASS)) {
941 Name sname = s.tsym.getQualifiedName();
942 return sname == names.java_lang_Object
943 || sname == names.java_lang_Cloneable
944 || sname == names.java_io_Serializable;
945 }
947 return false;
948 }
950 @Override
951 public Boolean visitUndetVar(UndetVar t, Type s) {
952 //todo: test against origin needed? or replace with substitution?
953 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
954 return true;
955 } else if (s.hasTag(BOT)) {
956 //if 's' is 'null' there's no instantiated type U for which
957 //U <: s (but 'null' itself, which is not a valid type)
958 return false;
959 }
961 t.addBound(InferenceBound.UPPER, s, Types.this);
962 return true;
963 }
965 @Override
966 public Boolean visitErrorType(ErrorType t, Type s) {
967 return true;
968 }
969 };
971 /**
972 * Is t a subtype of every type in given list `ts'?<br>
973 * (not defined for Method and ForAll types)<br>
974 * Allows unchecked conversions.
975 */
976 public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) {
977 for (List<Type> l = ts; l.nonEmpty(); l = l.tail)
978 if (!isSubtypeUnchecked(t, l.head, warn))
979 return false;
980 return true;
981 }
983 /**
984 * Are corresponding elements of ts subtypes of ss? If lists are
985 * of different length, return false.
986 */
987 public boolean isSubtypes(List<Type> ts, List<Type> ss) {
988 while (ts.tail != null && ss.tail != null
989 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
990 isSubtype(ts.head, ss.head)) {
991 ts = ts.tail;
992 ss = ss.tail;
993 }
994 return ts.tail == null && ss.tail == null;
995 /*inlined: ts.isEmpty() && ss.isEmpty();*/
996 }
998 /**
999 * Are corresponding elements of ts subtypes of ss, allowing
1000 * unchecked conversions? If lists are of different length,
1001 * return false.
1002 **/
1003 public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) {
1004 while (ts.tail != null && ss.tail != null
1005 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1006 isSubtypeUnchecked(ts.head, ss.head, warn)) {
1007 ts = ts.tail;
1008 ss = ss.tail;
1009 }
1010 return ts.tail == null && ss.tail == null;
1011 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1012 }
1013 // </editor-fold>
1015 // <editor-fold defaultstate="collapsed" desc="isSuperType">
1016 /**
1017 * Is t a supertype of s?
1018 */
1019 public boolean isSuperType(Type t, Type s) {
1020 switch (t.getTag()) {
1021 case ERROR:
1022 return true;
1023 case UNDETVAR: {
1024 UndetVar undet = (UndetVar)t;
1025 if (t == s ||
1026 undet.qtype == s ||
1027 s.hasTag(ERROR) ||
1028 s.hasTag(BOT)) {
1029 return true;
1030 }
1031 undet.addBound(InferenceBound.LOWER, s, this);
1032 return true;
1033 }
1034 default:
1035 return isSubtype(s, t);
1036 }
1037 }
1038 // </editor-fold>
1040 // <editor-fold defaultstate="collapsed" desc="isSameType">
1041 /**
1042 * Are corresponding elements of the lists the same type? If
1043 * lists are of different length, return false.
1044 */
1045 public boolean isSameTypes(List<Type> ts, List<Type> ss) {
1046 return isSameTypes(ts, ss, false);
1047 }
1048 public boolean isSameTypes(List<Type> ts, List<Type> ss, boolean strict) {
1049 while (ts.tail != null && ss.tail != null
1050 /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ &&
1051 isSameType(ts.head, ss.head, strict)) {
1052 ts = ts.tail;
1053 ss = ss.tail;
1054 }
1055 return ts.tail == null && ss.tail == null;
1056 /*inlined: ts.isEmpty() && ss.isEmpty();*/
1057 }
1059 /**
1060 * A polymorphic signature method (JLS SE 7, 8.4.1) is a method that
1061 * (i) is declared in the java.lang.invoke.MethodHandle class, (ii) takes
1062 * a single variable arity parameter (iii) whose declared type is Object[],
1063 * (iv) has a return type of Object and (v) is native.
1064 */
1065 public boolean isSignaturePolymorphic(MethodSymbol msym) {
1066 List<Type> argtypes = msym.type.getParameterTypes();
1067 return (msym.flags_field & NATIVE) != 0 &&
1068 msym.owner == syms.methodHandleType.tsym &&
1069 argtypes.tail.tail == null &&
1070 argtypes.head.hasTag(TypeTag.ARRAY) &&
1071 msym.type.getReturnType().tsym == syms.objectType.tsym &&
1072 ((ArrayType)argtypes.head).elemtype.tsym == syms.objectType.tsym;
1073 }
1075 /**
1076 * Is t the same type as s?
1077 */
1078 public boolean isSameType(Type t, Type s) {
1079 return isSameType(t, s, false);
1080 }
1081 public boolean isSameType(Type t, Type s, boolean strict) {
1082 return strict ?
1083 isSameTypeStrict.visit(t, s) :
1084 isSameTypeLoose.visit(t, s);
1085 }
1086 public boolean isSameAnnotatedType(Type t, Type s) {
1087 return isSameAnnotatedType.visit(t, s);
1088 }
1089 // where
1090 abstract class SameTypeVisitor extends TypeRelation {
1092 public Boolean visitType(Type t, Type s) {
1093 if (t == s)
1094 return true;
1096 if (s.isPartial())
1097 return visit(s, t);
1099 switch (t.getTag()) {
1100 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1101 case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE:
1102 return t.hasTag(s.getTag());
1103 case TYPEVAR: {
1104 if (s.hasTag(TYPEVAR)) {
1105 //type-substitution does not preserve type-var types
1106 //check that type var symbols and bounds are indeed the same
1107 return sameTypeVars((TypeVar)t.unannotatedType(), (TypeVar)s.unannotatedType());
1108 }
1109 else {
1110 //special case for s == ? super X, where upper(s) = u
1111 //check that u == t, where u has been set by Type.withTypeVar
1112 return s.isSuperBound() &&
1113 !s.isExtendsBound() &&
1114 visit(t, upperBound(s));
1115 }
1116 }
1117 default:
1118 throw new AssertionError("isSameType " + t.getTag());
1119 }
1120 }
1122 abstract boolean sameTypeVars(TypeVar tv1, TypeVar tv2);
1124 @Override
1125 public Boolean visitWildcardType(WildcardType t, Type s) {
1126 if (s.isPartial())
1127 return visit(s, t);
1128 else
1129 return false;
1130 }
1132 @Override
1133 public Boolean visitClassType(ClassType t, Type s) {
1134 if (t == s)
1135 return true;
1137 if (s.isPartial())
1138 return visit(s, t);
1140 if (s.isSuperBound() && !s.isExtendsBound())
1141 return visit(t, upperBound(s)) && visit(t, lowerBound(s));
1143 if (t.isCompound() && s.isCompound()) {
1144 if (!visit(supertype(t), supertype(s)))
1145 return false;
1147 HashSet<UniqueType> set = new HashSet<UniqueType>();
1148 for (Type x : interfaces(t))
1149 set.add(new UniqueType(x.unannotatedType(), Types.this));
1150 for (Type x : interfaces(s)) {
1151 if (!set.remove(new UniqueType(x.unannotatedType(), Types.this)))
1152 return false;
1153 }
1154 return (set.isEmpty());
1155 }
1156 return t.tsym == s.tsym
1157 && visit(t.getEnclosingType(), s.getEnclosingType())
1158 && containsTypes(t.getTypeArguments(), s.getTypeArguments());
1159 }
1161 abstract protected boolean containsTypes(List<Type> ts1, List<Type> ts2);
1163 @Override
1164 public Boolean visitArrayType(ArrayType t, Type s) {
1165 if (t == s)
1166 return true;
1168 if (s.isPartial())
1169 return visit(s, t);
1171 return s.hasTag(ARRAY)
1172 && containsTypeEquivalent(t.elemtype, elemtype(s));
1173 }
1175 @Override
1176 public Boolean visitMethodType(MethodType t, Type s) {
1177 // isSameType for methods does not take thrown
1178 // exceptions into account!
1179 return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType());
1180 }
1182 @Override
1183 public Boolean visitPackageType(PackageType t, Type s) {
1184 return t == s;
1185 }
1187 @Override
1188 public Boolean visitForAll(ForAll t, Type s) {
1189 if (!s.hasTag(FORALL)) {
1190 return false;
1191 }
1193 ForAll forAll = (ForAll)s;
1194 return hasSameBounds(t, forAll)
1195 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
1196 }
1198 @Override
1199 public Boolean visitUndetVar(UndetVar t, Type s) {
1200 if (s.hasTag(WILDCARD)) {
1201 // FIXME, this might be leftovers from before capture conversion
1202 return false;
1203 }
1205 if (t == s || t.qtype == s || s.hasTag(ERROR) || s.hasTag(UNKNOWN)) {
1206 return true;
1207 }
1209 t.addBound(InferenceBound.EQ, s, Types.this);
1211 return true;
1212 }
1214 @Override
1215 public Boolean visitErrorType(ErrorType t, Type s) {
1216 return true;
1217 }
1218 }
1220 /**
1221 * Standard type-equality relation - type variables are considered
1222 * equals if they share the same type symbol.
1223 */
1224 TypeRelation isSameTypeLoose = new LooseSameTypeVisitor();
1226 private class LooseSameTypeVisitor extends SameTypeVisitor {
1227 @Override
1228 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) {
1229 return tv1.tsym == tv2.tsym && visit(tv1.getUpperBound(), tv2.getUpperBound());
1230 }
1231 @Override
1232 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) {
1233 return containsTypeEquivalent(ts1, ts2);
1234 }
1235 };
1237 /**
1238 * Strict type-equality relation - type variables are considered
1239 * equals if they share the same object identity.
1240 */
1241 TypeRelation isSameTypeStrict = new SameTypeVisitor() {
1242 @Override
1243 boolean sameTypeVars(TypeVar tv1, TypeVar tv2) {
1244 return tv1 == tv2;
1245 }
1246 @Override
1247 protected boolean containsTypes(List<Type> ts1, List<Type> ts2) {
1248 return isSameTypes(ts1, ts2, true);
1249 }
1251 @Override
1252 public Boolean visitWildcardType(WildcardType t, Type s) {
1253 if (!s.hasTag(WILDCARD)) {
1254 return false;
1255 } else {
1256 WildcardType t2 = (WildcardType)s.unannotatedType();
1257 return t.kind == t2.kind &&
1258 isSameType(t.type, t2.type, true);
1259 }
1260 }
1261 };
1263 /**
1264 * A version of LooseSameTypeVisitor that takes AnnotatedTypes
1265 * into account.
1266 */
1267 TypeRelation isSameAnnotatedType = new LooseSameTypeVisitor() {
1268 @Override
1269 public Boolean visitAnnotatedType(AnnotatedType t, Type s) {
1270 if (!s.isAnnotated())
1271 return false;
1272 if (!t.getAnnotationMirrors().containsAll(s.getAnnotationMirrors()))
1273 return false;
1274 if (!s.getAnnotationMirrors().containsAll(t.getAnnotationMirrors()))
1275 return false;
1276 return visit(t.unannotatedType(), s);
1277 }
1278 };
1279 // </editor-fold>
1281 // <editor-fold defaultstate="collapsed" desc="Contains Type">
1282 public boolean containedBy(Type t, Type s) {
1283 switch (t.getTag()) {
1284 case UNDETVAR:
1285 if (s.hasTag(WILDCARD)) {
1286 UndetVar undetvar = (UndetVar)t;
1287 WildcardType wt = (WildcardType)s.unannotatedType();
1288 switch(wt.kind) {
1289 case UNBOUND: //similar to ? extends Object
1290 case EXTENDS: {
1291 Type bound = upperBound(s);
1292 undetvar.addBound(InferenceBound.UPPER, bound, this);
1293 break;
1294 }
1295 case SUPER: {
1296 Type bound = lowerBound(s);
1297 undetvar.addBound(InferenceBound.LOWER, bound, this);
1298 break;
1299 }
1300 }
1301 return true;
1302 } else {
1303 return isSameType(t, s);
1304 }
1305 case ERROR:
1306 return true;
1307 default:
1308 return containsType(s, t);
1309 }
1310 }
1312 boolean containsType(List<Type> ts, List<Type> ss) {
1313 while (ts.nonEmpty() && ss.nonEmpty()
1314 && containsType(ts.head, ss.head)) {
1315 ts = ts.tail;
1316 ss = ss.tail;
1317 }
1318 return ts.isEmpty() && ss.isEmpty();
1319 }
1321 /**
1322 * Check if t contains s.
1323 *
1324 * <p>T contains S if:
1325 *
1326 * <p>{@code L(T) <: L(S) && U(S) <: U(T)}
1327 *
1328 * <p>This relation is only used by ClassType.isSubtype(), that
1329 * is,
1330 *
1331 * <p>{@code C<S> <: C<T> if T contains S.}
1332 *
1333 * <p>Because of F-bounds, this relation can lead to infinite
1334 * recursion. Thus we must somehow break that recursion. Notice
1335 * that containsType() is only called from ClassType.isSubtype().
1336 * Since the arguments have already been checked against their
1337 * bounds, we know:
1338 *
1339 * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)}
1340 *
1341 * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)}
1342 *
1343 * @param t a type
1344 * @param s a type
1345 */
1346 public boolean containsType(Type t, Type s) {
1347 return containsType.visit(t, s);
1348 }
1349 // where
1350 private TypeRelation containsType = new TypeRelation() {
1352 private Type U(Type t) {
1353 while (t.hasTag(WILDCARD)) {
1354 WildcardType w = (WildcardType)t.unannotatedType();
1355 if (w.isSuperBound())
1356 return w.bound == null ? syms.objectType : w.bound.bound;
1357 else
1358 t = w.type;
1359 }
1360 return t;
1361 }
1363 private Type L(Type t) {
1364 while (t.hasTag(WILDCARD)) {
1365 WildcardType w = (WildcardType)t.unannotatedType();
1366 if (w.isExtendsBound())
1367 return syms.botType;
1368 else
1369 t = w.type;
1370 }
1371 return t;
1372 }
1374 public Boolean visitType(Type t, Type s) {
1375 if (s.isPartial())
1376 return containedBy(s, t);
1377 else
1378 return isSameType(t, s);
1379 }
1381 // void debugContainsType(WildcardType t, Type s) {
1382 // System.err.println();
1383 // System.err.format(" does %s contain %s?%n", t, s);
1384 // System.err.format(" %s U(%s) <: U(%s) %s = %s%n",
1385 // upperBound(s), s, t, U(t),
1386 // t.isSuperBound()
1387 // || isSubtypeNoCapture(upperBound(s), U(t)));
1388 // System.err.format(" %s L(%s) <: L(%s) %s = %s%n",
1389 // L(t), t, s, lowerBound(s),
1390 // t.isExtendsBound()
1391 // || isSubtypeNoCapture(L(t), lowerBound(s)));
1392 // System.err.println();
1393 // }
1395 @Override
1396 public Boolean visitWildcardType(WildcardType t, Type s) {
1397 if (s.isPartial())
1398 return containedBy(s, t);
1399 else {
1400 // debugContainsType(t, s);
1401 return isSameWildcard(t, s)
1402 || isCaptureOf(s, t)
1403 || ((t.isExtendsBound() || isSubtypeNoCapture(L(t), lowerBound(s))) &&
1404 (t.isSuperBound() || isSubtypeNoCapture(upperBound(s), U(t))));
1405 }
1406 }
1408 @Override
1409 public Boolean visitUndetVar(UndetVar t, Type s) {
1410 if (!s.hasTag(WILDCARD)) {
1411 return isSameType(t, s);
1412 } else {
1413 return false;
1414 }
1415 }
1417 @Override
1418 public Boolean visitErrorType(ErrorType t, Type s) {
1419 return true;
1420 }
1421 };
1423 public boolean isCaptureOf(Type s, WildcardType t) {
1424 if (!s.hasTag(TYPEVAR) || !((TypeVar)s.unannotatedType()).isCaptured())
1425 return false;
1426 return isSameWildcard(t, ((CapturedType)s.unannotatedType()).wildcard);
1427 }
1429 public boolean isSameWildcard(WildcardType t, Type s) {
1430 if (!s.hasTag(WILDCARD))
1431 return false;
1432 WildcardType w = (WildcardType)s.unannotatedType();
1433 return w.kind == t.kind && w.type == t.type;
1434 }
1436 public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) {
1437 while (ts.nonEmpty() && ss.nonEmpty()
1438 && containsTypeEquivalent(ts.head, ss.head)) {
1439 ts = ts.tail;
1440 ss = ss.tail;
1441 }
1442 return ts.isEmpty() && ss.isEmpty();
1443 }
1444 // </editor-fold>
1446 /**
1447 * Can t and s be compared for equality? Any primitive ==
1448 * primitive or primitive == object comparisons here are an error.
1449 * Unboxing and correct primitive == primitive comparisons are
1450 * already dealt with in Attr.visitBinary.
1451 *
1452 */
1453 public boolean isEqualityComparable(Type s, Type t, Warner warn) {
1454 if (t.isNumeric() && s.isNumeric())
1455 return true;
1457 boolean tPrimitive = t.isPrimitive();
1458 boolean sPrimitive = s.isPrimitive();
1459 if (!tPrimitive && !sPrimitive) {
1460 return isCastable(s, t, warn) || isCastable(t, s, warn);
1461 } else {
1462 return false;
1463 }
1464 }
1466 // <editor-fold defaultstate="collapsed" desc="isCastable">
1467 public boolean isCastable(Type t, Type s) {
1468 return isCastable(t, s, noWarnings);
1469 }
1471 /**
1472 * Is t is castable to s?<br>
1473 * s is assumed to be an erased type.<br>
1474 * (not defined for Method and ForAll types).
1475 */
1476 public boolean isCastable(Type t, Type s, Warner warn) {
1477 if (t == s)
1478 return true;
1480 if (t.isPrimitive() != s.isPrimitive())
1481 return allowBoxing && (
1482 isConvertible(t, s, warn)
1483 || (allowObjectToPrimitiveCast &&
1484 s.isPrimitive() &&
1485 isSubtype(boxedClass(s).type, t)));
1486 if (warn != warnStack.head) {
1487 try {
1488 warnStack = warnStack.prepend(warn);
1489 checkUnsafeVarargsConversion(t, s, warn);
1490 return isCastable.visit(t,s);
1491 } finally {
1492 warnStack = warnStack.tail;
1493 }
1494 } else {
1495 return isCastable.visit(t,s);
1496 }
1497 }
1498 // where
1499 private TypeRelation isCastable = new TypeRelation() {
1501 public Boolean visitType(Type t, Type s) {
1502 if (s.hasTag(ERROR))
1503 return true;
1505 switch (t.getTag()) {
1506 case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT:
1507 case DOUBLE:
1508 return s.isNumeric();
1509 case BOOLEAN:
1510 return s.hasTag(BOOLEAN);
1511 case VOID:
1512 return false;
1513 case BOT:
1514 return isSubtype(t, s);
1515 default:
1516 throw new AssertionError();
1517 }
1518 }
1520 @Override
1521 public Boolean visitWildcardType(WildcardType t, Type s) {
1522 return isCastable(upperBound(t), s, warnStack.head);
1523 }
1525 @Override
1526 public Boolean visitClassType(ClassType t, Type s) {
1527 if (s.hasTag(ERROR) || s.hasTag(BOT))
1528 return true;
1530 if (s.hasTag(TYPEVAR)) {
1531 if (isCastable(t, s.getUpperBound(), noWarnings)) {
1532 warnStack.head.warn(LintCategory.UNCHECKED);
1533 return true;
1534 } else {
1535 return false;
1536 }
1537 }
1539 if (t.isCompound() || s.isCompound()) {
1540 return !t.isCompound() ?
1541 visitIntersectionType((IntersectionClassType)s.unannotatedType(), t, true) :
1542 visitIntersectionType((IntersectionClassType)t.unannotatedType(), s, false);
1543 }
1545 if (s.hasTag(CLASS) || s.hasTag(ARRAY)) {
1546 boolean upcast;
1547 if ((upcast = isSubtype(erasure(t), erasure(s)))
1548 || isSubtype(erasure(s), erasure(t))) {
1549 if (!upcast && s.hasTag(ARRAY)) {
1550 if (!isReifiable(s))
1551 warnStack.head.warn(LintCategory.UNCHECKED);
1552 return true;
1553 } else if (s.isRaw()) {
1554 return true;
1555 } else if (t.isRaw()) {
1556 if (!isUnbounded(s))
1557 warnStack.head.warn(LintCategory.UNCHECKED);
1558 return true;
1559 }
1560 // Assume |a| <: |b|
1561 final Type a = upcast ? t : s;
1562 final Type b = upcast ? s : t;
1563 final boolean HIGH = true;
1564 final boolean LOW = false;
1565 final boolean DONT_REWRITE_TYPEVARS = false;
1566 Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS);
1567 Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS);
1568 Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS);
1569 Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS);
1570 Type lowSub = asSub(bLow, aLow.tsym);
1571 Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1572 if (highSub == null) {
1573 final boolean REWRITE_TYPEVARS = true;
1574 aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS);
1575 aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS);
1576 bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS);
1577 bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS);
1578 lowSub = asSub(bLow, aLow.tsym);
1579 highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym);
1580 }
1581 if (highSub != null) {
1582 if (!(a.tsym == highSub.tsym && a.tsym == lowSub.tsym)) {
1583 Assert.error(a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym);
1584 }
1585 if (!disjointTypes(aHigh.allparams(), highSub.allparams())
1586 && !disjointTypes(aHigh.allparams(), lowSub.allparams())
1587 && !disjointTypes(aLow.allparams(), highSub.allparams())
1588 && !disjointTypes(aLow.allparams(), lowSub.allparams())) {
1589 if (upcast ? giveWarning(a, b) :
1590 giveWarning(b, a))
1591 warnStack.head.warn(LintCategory.UNCHECKED);
1592 return true;
1593 }
1594 }
1595 if (isReifiable(s))
1596 return isSubtypeUnchecked(a, b);
1597 else
1598 return isSubtypeUnchecked(a, b, warnStack.head);
1599 }
1601 // Sidecast
1602 if (s.hasTag(CLASS)) {
1603 if ((s.tsym.flags() & INTERFACE) != 0) {
1604 return ((t.tsym.flags() & FINAL) == 0)
1605 ? sideCast(t, s, warnStack.head)
1606 : sideCastFinal(t, s, warnStack.head);
1607 } else if ((t.tsym.flags() & INTERFACE) != 0) {
1608 return ((s.tsym.flags() & FINAL) == 0)
1609 ? sideCast(t, s, warnStack.head)
1610 : sideCastFinal(t, s, warnStack.head);
1611 } else {
1612 // unrelated class types
1613 return false;
1614 }
1615 }
1616 }
1617 return false;
1618 }
1620 boolean visitIntersectionType(IntersectionClassType ict, Type s, boolean reverse) {
1621 Warner warn = noWarnings;
1622 for (Type c : ict.getComponents()) {
1623 warn.clear();
1624 if (reverse ? !isCastable(s, c, warn) : !isCastable(c, s, warn))
1625 return false;
1626 }
1627 if (warn.hasLint(LintCategory.UNCHECKED))
1628 warnStack.head.warn(LintCategory.UNCHECKED);
1629 return true;
1630 }
1632 @Override
1633 public Boolean visitArrayType(ArrayType t, Type s) {
1634 switch (s.getTag()) {
1635 case ERROR:
1636 case BOT:
1637 return true;
1638 case TYPEVAR:
1639 if (isCastable(s, t, noWarnings)) {
1640 warnStack.head.warn(LintCategory.UNCHECKED);
1641 return true;
1642 } else {
1643 return false;
1644 }
1645 case CLASS:
1646 return isSubtype(t, s);
1647 case ARRAY:
1648 if (elemtype(t).isPrimitive() || elemtype(s).isPrimitive()) {
1649 return elemtype(t).hasTag(elemtype(s).getTag());
1650 } else {
1651 return visit(elemtype(t), elemtype(s));
1652 }
1653 default:
1654 return false;
1655 }
1656 }
1658 @Override
1659 public Boolean visitTypeVar(TypeVar t, Type s) {
1660 switch (s.getTag()) {
1661 case ERROR:
1662 case BOT:
1663 return true;
1664 case TYPEVAR:
1665 if (isSubtype(t, s)) {
1666 return true;
1667 } else if (isCastable(t.bound, s, noWarnings)) {
1668 warnStack.head.warn(LintCategory.UNCHECKED);
1669 return true;
1670 } else {
1671 return false;
1672 }
1673 default:
1674 return isCastable(t.bound, s, warnStack.head);
1675 }
1676 }
1678 @Override
1679 public Boolean visitErrorType(ErrorType t, Type s) {
1680 return true;
1681 }
1682 };
1683 // </editor-fold>
1685 // <editor-fold defaultstate="collapsed" desc="disjointTypes">
1686 public boolean disjointTypes(List<Type> ts, List<Type> ss) {
1687 while (ts.tail != null && ss.tail != null) {
1688 if (disjointType(ts.head, ss.head)) return true;
1689 ts = ts.tail;
1690 ss = ss.tail;
1691 }
1692 return false;
1693 }
1695 /**
1696 * Two types or wildcards are considered disjoint if it can be
1697 * proven that no type can be contained in both. It is
1698 * conservative in that it is allowed to say that two types are
1699 * not disjoint, even though they actually are.
1700 *
1701 * The type {@code C<X>} is castable to {@code C<Y>} exactly if
1702 * {@code X} and {@code Y} are not disjoint.
1703 */
1704 public boolean disjointType(Type t, Type s) {
1705 return disjointType.visit(t, s);
1706 }
1707 // where
1708 private TypeRelation disjointType = new TypeRelation() {
1710 private Set<TypePair> cache = new HashSet<TypePair>();
1712 @Override
1713 public Boolean visitType(Type t, Type s) {
1714 if (s.hasTag(WILDCARD))
1715 return visit(s, t);
1716 else
1717 return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t);
1718 }
1720 private boolean isCastableRecursive(Type t, Type s) {
1721 TypePair pair = new TypePair(t, s);
1722 if (cache.add(pair)) {
1723 try {
1724 return Types.this.isCastable(t, s);
1725 } finally {
1726 cache.remove(pair);
1727 }
1728 } else {
1729 return true;
1730 }
1731 }
1733 private boolean notSoftSubtypeRecursive(Type t, Type s) {
1734 TypePair pair = new TypePair(t, s);
1735 if (cache.add(pair)) {
1736 try {
1737 return Types.this.notSoftSubtype(t, s);
1738 } finally {
1739 cache.remove(pair);
1740 }
1741 } else {
1742 return false;
1743 }
1744 }
1746 @Override
1747 public Boolean visitWildcardType(WildcardType t, Type s) {
1748 if (t.isUnbound())
1749 return false;
1751 if (!s.hasTag(WILDCARD)) {
1752 if (t.isExtendsBound())
1753 return notSoftSubtypeRecursive(s, t.type);
1754 else
1755 return notSoftSubtypeRecursive(t.type, s);
1756 }
1758 if (s.isUnbound())
1759 return false;
1761 if (t.isExtendsBound()) {
1762 if (s.isExtendsBound())
1763 return !isCastableRecursive(t.type, upperBound(s));
1764 else if (s.isSuperBound())
1765 return notSoftSubtypeRecursive(lowerBound(s), t.type);
1766 } else if (t.isSuperBound()) {
1767 if (s.isExtendsBound())
1768 return notSoftSubtypeRecursive(t.type, upperBound(s));
1769 }
1770 return false;
1771 }
1772 };
1773 // </editor-fold>
1775 // <editor-fold defaultstate="collapsed" desc="lowerBoundArgtypes">
1776 /**
1777 * Returns the lower bounds of the formals of a method.
1778 */
1779 public List<Type> lowerBoundArgtypes(Type t) {
1780 return lowerBounds(t.getParameterTypes());
1781 }
1782 public List<Type> lowerBounds(List<Type> ts) {
1783 return map(ts, lowerBoundMapping);
1784 }
1785 private final Mapping lowerBoundMapping = new Mapping("lowerBound") {
1786 public Type apply(Type t) {
1787 return lowerBound(t);
1788 }
1789 };
1790 // </editor-fold>
1792 // <editor-fold defaultstate="collapsed" desc="notSoftSubtype">
1793 /**
1794 * This relation answers the question: is impossible that
1795 * something of type `t' can be a subtype of `s'? This is
1796 * different from the question "is `t' not a subtype of `s'?"
1797 * when type variables are involved: Integer is not a subtype of T
1798 * where {@code <T extends Number>} but it is not true that Integer cannot
1799 * possibly be a subtype of T.
1800 */
1801 public boolean notSoftSubtype(Type t, Type s) {
1802 if (t == s) return false;
1803 if (t.hasTag(TYPEVAR)) {
1804 TypeVar tv = (TypeVar) t;
1805 return !isCastable(tv.bound,
1806 relaxBound(s),
1807 noWarnings);
1808 }
1809 if (!s.hasTag(WILDCARD))
1810 s = upperBound(s);
1812 return !isSubtype(t, relaxBound(s));
1813 }
1815 private Type relaxBound(Type t) {
1816 if (t.hasTag(TYPEVAR)) {
1817 while (t.hasTag(TYPEVAR))
1818 t = t.getUpperBound();
1819 t = rewriteQuantifiers(t, true, true);
1820 }
1821 return t;
1822 }
1823 // </editor-fold>
1825 // <editor-fold defaultstate="collapsed" desc="isReifiable">
1826 public boolean isReifiable(Type t) {
1827 return isReifiable.visit(t);
1828 }
1829 // where
1830 private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() {
1832 public Boolean visitType(Type t, Void ignored) {
1833 return true;
1834 }
1836 @Override
1837 public Boolean visitClassType(ClassType t, Void ignored) {
1838 if (t.isCompound())
1839 return false;
1840 else {
1841 if (!t.isParameterized())
1842 return true;
1844 for (Type param : t.allparams()) {
1845 if (!param.isUnbound())
1846 return false;
1847 }
1848 return true;
1849 }
1850 }
1852 @Override
1853 public Boolean visitArrayType(ArrayType t, Void ignored) {
1854 return visit(t.elemtype);
1855 }
1857 @Override
1858 public Boolean visitTypeVar(TypeVar t, Void ignored) {
1859 return false;
1860 }
1861 };
1862 // </editor-fold>
1864 // <editor-fold defaultstate="collapsed" desc="Array Utils">
1865 public boolean isArray(Type t) {
1866 while (t.hasTag(WILDCARD))
1867 t = upperBound(t);
1868 return t.hasTag(ARRAY);
1869 }
1871 /**
1872 * The element type of an array.
1873 */
1874 public Type elemtype(Type t) {
1875 switch (t.getTag()) {
1876 case WILDCARD:
1877 return elemtype(upperBound(t));
1878 case ARRAY:
1879 t = t.unannotatedType();
1880 return ((ArrayType)t).elemtype;
1881 case FORALL:
1882 return elemtype(((ForAll)t).qtype);
1883 case ERROR:
1884 return t;
1885 default:
1886 return null;
1887 }
1888 }
1890 public Type elemtypeOrType(Type t) {
1891 Type elemtype = elemtype(t);
1892 return elemtype != null ?
1893 elemtype :
1894 t;
1895 }
1897 /**
1898 * Mapping to take element type of an arraytype
1899 */
1900 private Mapping elemTypeFun = new Mapping ("elemTypeFun") {
1901 public Type apply(Type t) { return elemtype(t); }
1902 };
1904 /**
1905 * The number of dimensions of an array type.
1906 */
1907 public int dimensions(Type t) {
1908 int result = 0;
1909 while (t.hasTag(ARRAY)) {
1910 result++;
1911 t = elemtype(t);
1912 }
1913 return result;
1914 }
1916 /**
1917 * Returns an ArrayType with the component type t
1918 *
1919 * @param t The component type of the ArrayType
1920 * @return the ArrayType for the given component
1921 */
1922 public ArrayType makeArrayType(Type t) {
1923 if (t.hasTag(VOID) || t.hasTag(PACKAGE)) {
1924 Assert.error("Type t must not be a VOID or PACKAGE type, " + t.toString());
1925 }
1926 return new ArrayType(t, syms.arrayClass);
1927 }
1928 // </editor-fold>
1930 // <editor-fold defaultstate="collapsed" desc="asSuper">
1931 /**
1932 * Return the (most specific) base type of t that starts with the
1933 * given symbol. If none exists, return null.
1934 *
1935 * @param t a type
1936 * @param sym a symbol
1937 */
1938 public Type asSuper(Type t, Symbol s) {
1939 return asSuper(t, s.type);
1940 }
1942 public Type asSuper(Type t, Type s) {
1943 return asSuper.visit(t, s);
1944 }
1945 // where
1946 private SimpleVisitor<Type,Type> asSuper = new SimpleVisitor<Type,Type>() {
1948 public Type visitType(Type t, Type s) {
1949 return null;
1950 }
1952 @Override
1953 public Type visitClassType(ClassType t, Type s) {
1954 if (t.tsym == s.tsym)
1955 return t;
1957 Type st = supertype(t);
1959 switch(st.getTag()) {
1960 default: break;
1961 case CLASS:
1962 case ARRAY:
1963 case TYPEVAR:
1964 case ERROR: {
1965 Type x = asSuper(st, s);
1966 if (x != null)
1967 return x;
1968 } break;
1969 }
1971 if ((s.tsym.flags() & INTERFACE) != 0) {
1972 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
1973 Type x = asSuper(l.head, s);
1974 if (x != null)
1975 return x;
1976 }
1977 }
1978 return null;
1979 }
1981 @Override
1982 public Type visitArrayType(ArrayType t, Type s) {
1983 return isSubtype(t, s) ? s : null;
1984 }
1986 @Override
1987 public Type visitTypeVar(TypeVar t, Type s) {
1988 if (t.tsym == s.tsym)
1989 return t;
1990 else
1991 return asSuper(t.bound, s);
1992 }
1994 @Override
1995 public Type visitErrorType(ErrorType t, Type s) { return t; }
1996 };
1998 /**
1999 * Return the base type of t or any of its outer types that starts
2000 * with the given symbol. If none exists, return null.
2001 *
2002 * @param t a type
2003 * @param sym a symbol
2004 */
2005 public Type asOuterSuper(Type t, Symbol sym) {
2006 switch (t.getTag()) {
2007 case CLASS:
2008 do {
2009 Type s = asSuper(t, sym);
2010 if (s != null) return s;
2011 t = t.getEnclosingType();
2012 } while (t.hasTag(CLASS));
2013 return null;
2014 case ARRAY:
2015 return isSubtype(t, sym.type) ? sym.type : null;
2016 case TYPEVAR:
2017 return asSuper(t, sym);
2018 case ERROR:
2019 return t;
2020 default:
2021 return null;
2022 }
2023 }
2025 /**
2026 * Return the base type of t or any of its enclosing types that
2027 * starts with the given symbol. If none exists, return null.
2028 *
2029 * @param t a type
2030 * @param sym a symbol
2031 */
2032 public Type asEnclosingSuper(Type t, Symbol sym) {
2033 switch (t.getTag()) {
2034 case CLASS:
2035 do {
2036 Type s = asSuper(t, sym);
2037 if (s != null) return s;
2038 Type outer = t.getEnclosingType();
2039 t = (outer.hasTag(CLASS)) ? outer :
2040 (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type :
2041 Type.noType;
2042 } while (t.hasTag(CLASS));
2043 return null;
2044 case ARRAY:
2045 return isSubtype(t, sym.type) ? sym.type : null;
2046 case TYPEVAR:
2047 return asSuper(t, sym);
2048 case ERROR:
2049 return t;
2050 default:
2051 return null;
2052 }
2053 }
2054 // </editor-fold>
2056 // <editor-fold defaultstate="collapsed" desc="memberType">
2057 /**
2058 * The type of given symbol, seen as a member of t.
2059 *
2060 * @param t a type
2061 * @param sym a symbol
2062 */
2063 public Type memberType(Type t, Symbol sym) {
2064 return (sym.flags() & STATIC) != 0
2065 ? sym.type
2066 : memberType.visit(t, sym);
2067 }
2068 // where
2069 private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() {
2071 public Type visitType(Type t, Symbol sym) {
2072 return sym.type;
2073 }
2075 @Override
2076 public Type visitWildcardType(WildcardType t, Symbol sym) {
2077 return memberType(upperBound(t), sym);
2078 }
2080 @Override
2081 public Type visitClassType(ClassType t, Symbol sym) {
2082 Symbol owner = sym.owner;
2083 long flags = sym.flags();
2084 if (((flags & STATIC) == 0) && owner.type.isParameterized()) {
2085 Type base = asOuterSuper(t, owner);
2086 //if t is an intersection type T = CT & I1 & I2 ... & In
2087 //its supertypes CT, I1, ... In might contain wildcards
2088 //so we need to go through capture conversion
2089 base = t.isCompound() ? capture(base) : base;
2090 if (base != null) {
2091 List<Type> ownerParams = owner.type.allparams();
2092 List<Type> baseParams = base.allparams();
2093 if (ownerParams.nonEmpty()) {
2094 if (baseParams.isEmpty()) {
2095 // then base is a raw type
2096 return erasure(sym.type);
2097 } else {
2098 return subst(sym.type, ownerParams, baseParams);
2099 }
2100 }
2101 }
2102 }
2103 return sym.type;
2104 }
2106 @Override
2107 public Type visitTypeVar(TypeVar t, Symbol sym) {
2108 return memberType(t.bound, sym);
2109 }
2111 @Override
2112 public Type visitErrorType(ErrorType t, Symbol sym) {
2113 return t;
2114 }
2115 };
2116 // </editor-fold>
2118 // <editor-fold defaultstate="collapsed" desc="isAssignable">
2119 public boolean isAssignable(Type t, Type s) {
2120 return isAssignable(t, s, noWarnings);
2121 }
2123 /**
2124 * Is t assignable to s?<br>
2125 * Equivalent to subtype except for constant values and raw
2126 * types.<br>
2127 * (not defined for Method and ForAll types)
2128 */
2129 public boolean isAssignable(Type t, Type s, Warner warn) {
2130 if (t.hasTag(ERROR))
2131 return true;
2132 if (t.getTag().isSubRangeOf(INT) && t.constValue() != null) {
2133 int value = ((Number)t.constValue()).intValue();
2134 switch (s.getTag()) {
2135 case BYTE:
2136 if (Byte.MIN_VALUE <= value && value <= Byte.MAX_VALUE)
2137 return true;
2138 break;
2139 case CHAR:
2140 if (Character.MIN_VALUE <= value && value <= Character.MAX_VALUE)
2141 return true;
2142 break;
2143 case SHORT:
2144 if (Short.MIN_VALUE <= value && value <= Short.MAX_VALUE)
2145 return true;
2146 break;
2147 case INT:
2148 return true;
2149 case CLASS:
2150 switch (unboxedType(s).getTag()) {
2151 case BYTE:
2152 case CHAR:
2153 case SHORT:
2154 return isAssignable(t, unboxedType(s), warn);
2155 }
2156 break;
2157 }
2158 }
2159 return isConvertible(t, s, warn);
2160 }
2161 // </editor-fold>
2163 // <editor-fold defaultstate="collapsed" desc="erasure">
2164 /**
2165 * The erasure of t {@code |t|} -- the type that results when all
2166 * type parameters in t are deleted.
2167 */
2168 public Type erasure(Type t) {
2169 return eraseNotNeeded(t)? t : erasure(t, false);
2170 }
2171 //where
2172 private boolean eraseNotNeeded(Type t) {
2173 // We don't want to erase primitive types and String type as that
2174 // operation is idempotent. Also, erasing these could result in loss
2175 // of information such as constant values attached to such types.
2176 return (t.isPrimitive()) || (syms.stringType.tsym == t.tsym);
2177 }
2179 private Type erasure(Type t, boolean recurse) {
2180 if (t.isPrimitive())
2181 return t; /* fast special case */
2182 else
2183 return erasure.visit(t, recurse);
2184 }
2185 // where
2186 private SimpleVisitor<Type, Boolean> erasure = new SimpleVisitor<Type, Boolean>() {
2187 public Type visitType(Type t, Boolean recurse) {
2188 if (t.isPrimitive())
2189 return t; /*fast special case*/
2190 else
2191 return t.map(recurse ? erasureRecFun : erasureFun);
2192 }
2194 @Override
2195 public Type visitWildcardType(WildcardType t, Boolean recurse) {
2196 return erasure(upperBound(t), recurse);
2197 }
2199 @Override
2200 public Type visitClassType(ClassType t, Boolean recurse) {
2201 Type erased = t.tsym.erasure(Types.this);
2202 if (recurse) {
2203 erased = new ErasedClassType(erased.getEnclosingType(),erased.tsym);
2204 }
2205 return erased;
2206 }
2208 @Override
2209 public Type visitTypeVar(TypeVar t, Boolean recurse) {
2210 return erasure(t.bound, recurse);
2211 }
2213 @Override
2214 public Type visitErrorType(ErrorType t, Boolean recurse) {
2215 return t;
2216 }
2218 @Override
2219 public Type visitAnnotatedType(AnnotatedType t, Boolean recurse) {
2220 Type erased = erasure(t.unannotatedType(), recurse);
2221 if (erased.isAnnotated()) {
2222 // This can only happen when the underlying type is a
2223 // type variable and the upper bound of it is annotated.
2224 // The annotation on the type variable overrides the one
2225 // on the bound.
2226 erased = ((AnnotatedType)erased).unannotatedType();
2227 }
2228 return erased.annotatedType(t.getAnnotationMirrors());
2229 }
2230 };
2232 private Mapping erasureFun = new Mapping ("erasure") {
2233 public Type apply(Type t) { return erasure(t); }
2234 };
2236 private Mapping erasureRecFun = new Mapping ("erasureRecursive") {
2237 public Type apply(Type t) { return erasureRecursive(t); }
2238 };
2240 public List<Type> erasure(List<Type> ts) {
2241 return Type.map(ts, erasureFun);
2242 }
2244 public Type erasureRecursive(Type t) {
2245 return erasure(t, true);
2246 }
2248 public List<Type> erasureRecursive(List<Type> ts) {
2249 return Type.map(ts, erasureRecFun);
2250 }
2251 // </editor-fold>
2253 // <editor-fold defaultstate="collapsed" desc="makeCompoundType">
2254 /**
2255 * Make a compound type from non-empty list of types
2256 *
2257 * @param bounds the types from which the compound type is formed
2258 * @param supertype is objectType if all bounds are interfaces,
2259 * null otherwise.
2260 */
2261 public Type makeCompoundType(List<Type> bounds) {
2262 return makeCompoundType(bounds, bounds.head.tsym.isInterface());
2263 }
2264 public Type makeCompoundType(List<Type> bounds, boolean allInterfaces) {
2265 Assert.check(bounds.nonEmpty());
2266 Type firstExplicitBound = bounds.head;
2267 if (allInterfaces) {
2268 bounds = bounds.prepend(syms.objectType);
2269 }
2270 ClassSymbol bc =
2271 new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC,
2272 Type.moreInfo
2273 ? names.fromString(bounds.toString())
2274 : names.empty,
2275 null,
2276 syms.noSymbol);
2277 bc.type = new IntersectionClassType(bounds, bc, allInterfaces);
2278 bc.erasure_field = (bounds.head.hasTag(TYPEVAR)) ?
2279 syms.objectType : // error condition, recover
2280 erasure(firstExplicitBound);
2281 bc.members_field = new Scope(bc);
2282 return bc.type;
2283 }
2285 /**
2286 * A convenience wrapper for {@link #makeCompoundType(List)}; the
2287 * arguments are converted to a list and passed to the other
2288 * method. Note that this might cause a symbol completion.
2289 * Hence, this version of makeCompoundType may not be called
2290 * during a classfile read.
2291 */
2292 public Type makeCompoundType(Type bound1, Type bound2) {
2293 return makeCompoundType(List.of(bound1, bound2));
2294 }
2295 // </editor-fold>
2297 // <editor-fold defaultstate="collapsed" desc="supertype">
2298 public Type supertype(Type t) {
2299 return supertype.visit(t);
2300 }
2301 // where
2302 private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() {
2304 public Type visitType(Type t, Void ignored) {
2305 // A note on wildcards: there is no good way to
2306 // determine a supertype for a super bounded wildcard.
2307 return null;
2308 }
2310 @Override
2311 public Type visitClassType(ClassType t, Void ignored) {
2312 if (t.supertype_field == null) {
2313 Type supertype = ((ClassSymbol)t.tsym).getSuperclass();
2314 // An interface has no superclass; its supertype is Object.
2315 if (t.isInterface())
2316 supertype = ((ClassType)t.tsym.type).supertype_field;
2317 if (t.supertype_field == null) {
2318 List<Type> actuals = classBound(t).allparams();
2319 List<Type> formals = t.tsym.type.allparams();
2320 if (t.hasErasedSupertypes()) {
2321 t.supertype_field = erasureRecursive(supertype);
2322 } else if (formals.nonEmpty()) {
2323 t.supertype_field = subst(supertype, formals, actuals);
2324 }
2325 else {
2326 t.supertype_field = supertype;
2327 }
2328 }
2329 }
2330 return t.supertype_field;
2331 }
2333 /**
2334 * The supertype is always a class type. If the type
2335 * variable's bounds start with a class type, this is also
2336 * the supertype. Otherwise, the supertype is
2337 * java.lang.Object.
2338 */
2339 @Override
2340 public Type visitTypeVar(TypeVar t, Void ignored) {
2341 if (t.bound.hasTag(TYPEVAR) ||
2342 (!t.bound.isCompound() && !t.bound.isInterface())) {
2343 return t.bound;
2344 } else {
2345 return supertype(t.bound);
2346 }
2347 }
2349 @Override
2350 public Type visitArrayType(ArrayType t, Void ignored) {
2351 if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType))
2352 return arraySuperType();
2353 else
2354 return new ArrayType(supertype(t.elemtype), t.tsym);
2355 }
2357 @Override
2358 public Type visitErrorType(ErrorType t, Void ignored) {
2359 return Type.noType;
2360 }
2361 };
2362 // </editor-fold>
2364 // <editor-fold defaultstate="collapsed" desc="interfaces">
2365 /**
2366 * Return the interfaces implemented by this class.
2367 */
2368 public List<Type> interfaces(Type t) {
2369 return interfaces.visit(t);
2370 }
2371 // where
2372 private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() {
2374 public List<Type> visitType(Type t, Void ignored) {
2375 return List.nil();
2376 }
2378 @Override
2379 public List<Type> visitClassType(ClassType t, Void ignored) {
2380 if (t.interfaces_field == null) {
2381 List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces();
2382 if (t.interfaces_field == null) {
2383 // If t.interfaces_field is null, then t must
2384 // be a parameterized type (not to be confused
2385 // with a generic type declaration).
2386 // Terminology:
2387 // Parameterized type: List<String>
2388 // Generic type declaration: class List<E> { ... }
2389 // So t corresponds to List<String> and
2390 // t.tsym.type corresponds to List<E>.
2391 // The reason t must be parameterized type is
2392 // that completion will happen as a side
2393 // effect of calling
2394 // ClassSymbol.getInterfaces. Since
2395 // t.interfaces_field is null after
2396 // completion, we can assume that t is not the
2397 // type of a class/interface declaration.
2398 Assert.check(t != t.tsym.type, t);
2399 List<Type> actuals = t.allparams();
2400 List<Type> formals = t.tsym.type.allparams();
2401 if (t.hasErasedSupertypes()) {
2402 t.interfaces_field = erasureRecursive(interfaces);
2403 } else if (formals.nonEmpty()) {
2404 t.interfaces_field =
2405 upperBounds(subst(interfaces, formals, actuals));
2406 }
2407 else {
2408 t.interfaces_field = interfaces;
2409 }
2410 }
2411 }
2412 return t.interfaces_field;
2413 }
2415 @Override
2416 public List<Type> visitTypeVar(TypeVar t, Void ignored) {
2417 if (t.bound.isCompound())
2418 return interfaces(t.bound);
2420 if (t.bound.isInterface())
2421 return List.of(t.bound);
2423 return List.nil();
2424 }
2425 };
2427 public List<Type> directSupertypes(Type t) {
2428 return directSupertypes.visit(t);
2429 }
2430 // where
2431 private final UnaryVisitor<List<Type>> directSupertypes = new UnaryVisitor<List<Type>>() {
2433 public List<Type> visitType(final Type type, final Void ignored) {
2434 if (!type.isCompound()) {
2435 final Type sup = supertype(type);
2436 return (sup == Type.noType || sup == type || sup == null)
2437 ? interfaces(type)
2438 : interfaces(type).prepend(sup);
2439 } else {
2440 return visitIntersectionType((IntersectionClassType) type);
2441 }
2442 }
2444 private List<Type> visitIntersectionType(final IntersectionClassType it) {
2445 return it.getExplicitComponents();
2446 }
2448 };
2450 public boolean isDirectSuperInterface(TypeSymbol isym, TypeSymbol origin) {
2451 for (Type i2 : interfaces(origin.type)) {
2452 if (isym == i2.tsym) return true;
2453 }
2454 return false;
2455 }
2456 // </editor-fold>
2458 // <editor-fold defaultstate="collapsed" desc="isDerivedRaw">
2459 Map<Type,Boolean> isDerivedRawCache = new HashMap<Type,Boolean>();
2461 public boolean isDerivedRaw(Type t) {
2462 Boolean result = isDerivedRawCache.get(t);
2463 if (result == null) {
2464 result = isDerivedRawInternal(t);
2465 isDerivedRawCache.put(t, result);
2466 }
2467 return result;
2468 }
2470 public boolean isDerivedRawInternal(Type t) {
2471 if (t.isErroneous())
2472 return false;
2473 return
2474 t.isRaw() ||
2475 supertype(t) != null && isDerivedRaw(supertype(t)) ||
2476 isDerivedRaw(interfaces(t));
2477 }
2479 public boolean isDerivedRaw(List<Type> ts) {
2480 List<Type> l = ts;
2481 while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail;
2482 return l.nonEmpty();
2483 }
2484 // </editor-fold>
2486 // <editor-fold defaultstate="collapsed" desc="setBounds">
2487 /**
2488 * Set the bounds field of the given type variable to reflect a
2489 * (possibly multiple) list of bounds.
2490 * @param t a type variable
2491 * @param bounds the bounds, must be nonempty
2492 * @param supertype is objectType if all bounds are interfaces,
2493 * null otherwise.
2494 */
2495 public void setBounds(TypeVar t, List<Type> bounds) {
2496 setBounds(t, bounds, bounds.head.tsym.isInterface());
2497 }
2499 /**
2500 * Same as {@link #setBounds(Type.TypeVar,List,Type)}, except that
2501 * third parameter is computed directly, as follows: if all
2502 * all bounds are interface types, the computed supertype is Object,
2503 * otherwise the supertype is simply left null (in this case, the supertype
2504 * is assumed to be the head of the bound list passed as second argument).
2505 * Note that this check might cause a symbol completion. Hence, this version of
2506 * setBounds may not be called during a classfile read.
2507 */
2508 public void setBounds(TypeVar t, List<Type> bounds, boolean allInterfaces) {
2509 t.bound = bounds.tail.isEmpty() ?
2510 bounds.head :
2511 makeCompoundType(bounds, allInterfaces);
2512 t.rank_field = -1;
2513 }
2514 // </editor-fold>
2516 // <editor-fold defaultstate="collapsed" desc="getBounds">
2517 /**
2518 * Return list of bounds of the given type variable.
2519 */
2520 public List<Type> getBounds(TypeVar t) {
2521 if (t.bound.hasTag(NONE))
2522 return List.nil();
2523 else if (t.bound.isErroneous() || !t.bound.isCompound())
2524 return List.of(t.bound);
2525 else if ((erasure(t).tsym.flags() & INTERFACE) == 0)
2526 return interfaces(t).prepend(supertype(t));
2527 else
2528 // No superclass was given in bounds.
2529 // In this case, supertype is Object, erasure is first interface.
2530 return interfaces(t);
2531 }
2532 // </editor-fold>
2534 // <editor-fold defaultstate="collapsed" desc="classBound">
2535 /**
2536 * If the given type is a (possibly selected) type variable,
2537 * return the bounding class of this type, otherwise return the
2538 * type itself.
2539 */
2540 public Type classBound(Type t) {
2541 return classBound.visit(t);
2542 }
2543 // where
2544 private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() {
2546 public Type visitType(Type t, Void ignored) {
2547 return t;
2548 }
2550 @Override
2551 public Type visitClassType(ClassType t, Void ignored) {
2552 Type outer1 = classBound(t.getEnclosingType());
2553 if (outer1 != t.getEnclosingType())
2554 return new ClassType(outer1, t.getTypeArguments(), t.tsym);
2555 else
2556 return t;
2557 }
2559 @Override
2560 public Type visitTypeVar(TypeVar t, Void ignored) {
2561 return classBound(supertype(t));
2562 }
2564 @Override
2565 public Type visitErrorType(ErrorType t, Void ignored) {
2566 return t;
2567 }
2568 };
2569 // </editor-fold>
2571 // <editor-fold defaultstate="collapsed" desc="sub signature / override equivalence">
2572 /**
2573 * Returns true iff the first signature is a <em>sub
2574 * signature</em> of the other. This is <b>not</b> an equivalence
2575 * relation.
2576 *
2577 * @jls section 8.4.2.
2578 * @see #overrideEquivalent(Type t, Type s)
2579 * @param t first signature (possibly raw).
2580 * @param s second signature (could be subjected to erasure).
2581 * @return true if t is a sub signature of s.
2582 */
2583 public boolean isSubSignature(Type t, Type s) {
2584 return isSubSignature(t, s, true);
2585 }
2587 public boolean isSubSignature(Type t, Type s, boolean strict) {
2588 return hasSameArgs(t, s, strict) || hasSameArgs(t, erasure(s), strict);
2589 }
2591 /**
2592 * Returns true iff these signatures are related by <em>override
2593 * equivalence</em>. This is the natural extension of
2594 * isSubSignature to an equivalence relation.
2595 *
2596 * @jls section 8.4.2.
2597 * @see #isSubSignature(Type t, Type s)
2598 * @param t a signature (possible raw, could be subjected to
2599 * erasure).
2600 * @param s a signature (possible raw, could be subjected to
2601 * erasure).
2602 * @return true if either argument is a sub signature of the other.
2603 */
2604 public boolean overrideEquivalent(Type t, Type s) {
2605 return hasSameArgs(t, s) ||
2606 hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s);
2607 }
2609 public boolean overridesObjectMethod(TypeSymbol origin, Symbol msym) {
2610 for (Scope.Entry e = syms.objectType.tsym.members().lookup(msym.name) ; e.scope != null ; e = e.next()) {
2611 if (msym.overrides(e.sym, origin, Types.this, true)) {
2612 return true;
2613 }
2614 }
2615 return false;
2616 }
2618 // <editor-fold defaultstate="collapsed" desc="Determining method implementation in given site">
2619 class ImplementationCache {
2621 private WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>> _map =
2622 new WeakHashMap<MethodSymbol, SoftReference<Map<TypeSymbol, Entry>>>();
2624 class Entry {
2625 final MethodSymbol cachedImpl;
2626 final Filter<Symbol> implFilter;
2627 final boolean checkResult;
2628 final int prevMark;
2630 public Entry(MethodSymbol cachedImpl,
2631 Filter<Symbol> scopeFilter,
2632 boolean checkResult,
2633 int prevMark) {
2634 this.cachedImpl = cachedImpl;
2635 this.implFilter = scopeFilter;
2636 this.checkResult = checkResult;
2637 this.prevMark = prevMark;
2638 }
2640 boolean matches(Filter<Symbol> scopeFilter, boolean checkResult, int mark) {
2641 return this.implFilter == scopeFilter &&
2642 this.checkResult == checkResult &&
2643 this.prevMark == mark;
2644 }
2645 }
2647 MethodSymbol get(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2648 SoftReference<Map<TypeSymbol, Entry>> ref_cache = _map.get(ms);
2649 Map<TypeSymbol, Entry> cache = ref_cache != null ? ref_cache.get() : null;
2650 if (cache == null) {
2651 cache = new HashMap<TypeSymbol, Entry>();
2652 _map.put(ms, new SoftReference<Map<TypeSymbol, Entry>>(cache));
2653 }
2654 Entry e = cache.get(origin);
2655 CompoundScope members = membersClosure(origin.type, true);
2656 if (e == null ||
2657 !e.matches(implFilter, checkResult, members.getMark())) {
2658 MethodSymbol impl = implementationInternal(ms, origin, checkResult, implFilter);
2659 cache.put(origin, new Entry(impl, implFilter, checkResult, members.getMark()));
2660 return impl;
2661 }
2662 else {
2663 return e.cachedImpl;
2664 }
2665 }
2667 private MethodSymbol implementationInternal(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2668 for (Type t = origin.type; t.hasTag(CLASS) || t.hasTag(TYPEVAR); t = supertype(t)) {
2669 while (t.hasTag(TYPEVAR))
2670 t = t.getUpperBound();
2671 TypeSymbol c = t.tsym;
2672 for (Scope.Entry e = c.members().lookup(ms.name, implFilter);
2673 e.scope != null;
2674 e = e.next(implFilter)) {
2675 if (e.sym != null &&
2676 e.sym.overrides(ms, origin, Types.this, checkResult))
2677 return (MethodSymbol)e.sym;
2678 }
2679 }
2680 return null;
2681 }
2682 }
2684 private ImplementationCache implCache = new ImplementationCache();
2686 public MethodSymbol implementation(MethodSymbol ms, TypeSymbol origin, boolean checkResult, Filter<Symbol> implFilter) {
2687 return implCache.get(ms, origin, checkResult, implFilter);
2688 }
2689 // </editor-fold>
2691 // <editor-fold defaultstate="collapsed" desc="compute transitive closure of all members in given site">
2692 class MembersClosureCache extends SimpleVisitor<CompoundScope, Boolean> {
2694 private WeakHashMap<TypeSymbol, Entry> _map =
2695 new WeakHashMap<TypeSymbol, Entry>();
2697 class Entry {
2698 final boolean skipInterfaces;
2699 final CompoundScope compoundScope;
2701 public Entry(boolean skipInterfaces, CompoundScope compoundScope) {
2702 this.skipInterfaces = skipInterfaces;
2703 this.compoundScope = compoundScope;
2704 }
2706 boolean matches(boolean skipInterfaces) {
2707 return this.skipInterfaces == skipInterfaces;
2708 }
2709 }
2711 List<TypeSymbol> seenTypes = List.nil();
2713 /** members closure visitor methods **/
2715 public CompoundScope visitType(Type t, Boolean skipInterface) {
2716 return null;
2717 }
2719 @Override
2720 public CompoundScope visitClassType(ClassType t, Boolean skipInterface) {
2721 if (seenTypes.contains(t.tsym)) {
2722 //this is possible when an interface is implemented in multiple
2723 //superclasses, or when a classs hierarchy is circular - in such
2724 //cases we don't need to recurse (empty scope is returned)
2725 return new CompoundScope(t.tsym);
2726 }
2727 try {
2728 seenTypes = seenTypes.prepend(t.tsym);
2729 ClassSymbol csym = (ClassSymbol)t.tsym;
2730 Entry e = _map.get(csym);
2731 if (e == null || !e.matches(skipInterface)) {
2732 CompoundScope membersClosure = new CompoundScope(csym);
2733 if (!skipInterface) {
2734 for (Type i : interfaces(t)) {
2735 membersClosure.addSubScope(visit(i, skipInterface));
2736 }
2737 }
2738 membersClosure.addSubScope(visit(supertype(t), skipInterface));
2739 membersClosure.addSubScope(csym.members());
2740 e = new Entry(skipInterface, membersClosure);
2741 _map.put(csym, e);
2742 }
2743 return e.compoundScope;
2744 }
2745 finally {
2746 seenTypes = seenTypes.tail;
2747 }
2748 }
2750 @Override
2751 public CompoundScope visitTypeVar(TypeVar t, Boolean skipInterface) {
2752 return visit(t.getUpperBound(), skipInterface);
2753 }
2754 }
2756 private MembersClosureCache membersCache = new MembersClosureCache();
2758 public CompoundScope membersClosure(Type site, boolean skipInterface) {
2759 return membersCache.visit(site, skipInterface);
2760 }
2761 // </editor-fold>
2764 //where
2765 public List<MethodSymbol> interfaceCandidates(Type site, MethodSymbol ms) {
2766 Filter<Symbol> filter = new MethodFilter(ms, site);
2767 List<MethodSymbol> candidates = List.nil();
2768 for (Symbol s : membersClosure(site, false).getElements(filter)) {
2769 if (!site.tsym.isInterface() && !s.owner.isInterface()) {
2770 return List.of((MethodSymbol)s);
2771 } else if (!candidates.contains(s)) {
2772 candidates = candidates.prepend((MethodSymbol)s);
2773 }
2774 }
2775 return prune(candidates);
2776 }
2778 public List<MethodSymbol> prune(List<MethodSymbol> methods) {
2779 ListBuffer<MethodSymbol> methodsMin = new ListBuffer<>();
2780 for (MethodSymbol m1 : methods) {
2781 boolean isMin_m1 = true;
2782 for (MethodSymbol m2 : methods) {
2783 if (m1 == m2) continue;
2784 if (m2.owner != m1.owner &&
2785 asSuper(m2.owner.type, m1.owner) != null) {
2786 isMin_m1 = false;
2787 break;
2788 }
2789 }
2790 if (isMin_m1)
2791 methodsMin.append(m1);
2792 }
2793 return methodsMin.toList();
2794 }
2795 // where
2796 private class MethodFilter implements Filter<Symbol> {
2798 Symbol msym;
2799 Type site;
2801 MethodFilter(Symbol msym, Type site) {
2802 this.msym = msym;
2803 this.site = site;
2804 }
2806 public boolean accepts(Symbol s) {
2807 return s.kind == Kinds.MTH &&
2808 s.name == msym.name &&
2809 (s.flags() & SYNTHETIC) == 0 &&
2810 s.isInheritedIn(site.tsym, Types.this) &&
2811 overrideEquivalent(memberType(site, s), memberType(site, msym));
2812 }
2813 };
2814 // </editor-fold>
2816 /**
2817 * Does t have the same arguments as s? It is assumed that both
2818 * types are (possibly polymorphic) method types. Monomorphic
2819 * method types "have the same arguments", if their argument lists
2820 * are equal. Polymorphic method types "have the same arguments",
2821 * if they have the same arguments after renaming all type
2822 * variables of one to corresponding type variables in the other,
2823 * where correspondence is by position in the type parameter list.
2824 */
2825 public boolean hasSameArgs(Type t, Type s) {
2826 return hasSameArgs(t, s, true);
2827 }
2829 public boolean hasSameArgs(Type t, Type s, boolean strict) {
2830 return hasSameArgs(t, s, strict ? hasSameArgs_strict : hasSameArgs_nonstrict);
2831 }
2833 private boolean hasSameArgs(Type t, Type s, TypeRelation hasSameArgs) {
2834 return hasSameArgs.visit(t, s);
2835 }
2836 // where
2837 private class HasSameArgs extends TypeRelation {
2839 boolean strict;
2841 public HasSameArgs(boolean strict) {
2842 this.strict = strict;
2843 }
2845 public Boolean visitType(Type t, Type s) {
2846 throw new AssertionError();
2847 }
2849 @Override
2850 public Boolean visitMethodType(MethodType t, Type s) {
2851 return s.hasTag(METHOD)
2852 && containsTypeEquivalent(t.argtypes, s.getParameterTypes());
2853 }
2855 @Override
2856 public Boolean visitForAll(ForAll t, Type s) {
2857 if (!s.hasTag(FORALL))
2858 return strict ? false : visitMethodType(t.asMethodType(), s);
2860 ForAll forAll = (ForAll)s;
2861 return hasSameBounds(t, forAll)
2862 && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars));
2863 }
2865 @Override
2866 public Boolean visitErrorType(ErrorType t, Type s) {
2867 return false;
2868 }
2869 };
2871 TypeRelation hasSameArgs_strict = new HasSameArgs(true);
2872 TypeRelation hasSameArgs_nonstrict = new HasSameArgs(false);
2874 // </editor-fold>
2876 // <editor-fold defaultstate="collapsed" desc="subst">
2877 public List<Type> subst(List<Type> ts,
2878 List<Type> from,
2879 List<Type> to) {
2880 return new Subst(from, to).subst(ts);
2881 }
2883 /**
2884 * Substitute all occurrences of a type in `from' with the
2885 * corresponding type in `to' in 't'. Match lists `from' and `to'
2886 * from the right: If lists have different length, discard leading
2887 * elements of the longer list.
2888 */
2889 public Type subst(Type t, List<Type> from, List<Type> to) {
2890 return new Subst(from, to).subst(t);
2891 }
2893 private class Subst extends UnaryVisitor<Type> {
2894 List<Type> from;
2895 List<Type> to;
2897 public Subst(List<Type> from, List<Type> to) {
2898 int fromLength = from.length();
2899 int toLength = to.length();
2900 while (fromLength > toLength) {
2901 fromLength--;
2902 from = from.tail;
2903 }
2904 while (fromLength < toLength) {
2905 toLength--;
2906 to = to.tail;
2907 }
2908 this.from = from;
2909 this.to = to;
2910 }
2912 Type subst(Type t) {
2913 if (from.tail == null)
2914 return t;
2915 else
2916 return visit(t);
2917 }
2919 List<Type> subst(List<Type> ts) {
2920 if (from.tail == null)
2921 return ts;
2922 boolean wild = false;
2923 if (ts.nonEmpty() && from.nonEmpty()) {
2924 Type head1 = subst(ts.head);
2925 List<Type> tail1 = subst(ts.tail);
2926 if (head1 != ts.head || tail1 != ts.tail)
2927 return tail1.prepend(head1);
2928 }
2929 return ts;
2930 }
2932 public Type visitType(Type t, Void ignored) {
2933 return t;
2934 }
2936 @Override
2937 public Type visitMethodType(MethodType t, Void ignored) {
2938 List<Type> argtypes = subst(t.argtypes);
2939 Type restype = subst(t.restype);
2940 List<Type> thrown = subst(t.thrown);
2941 if (argtypes == t.argtypes &&
2942 restype == t.restype &&
2943 thrown == t.thrown)
2944 return t;
2945 else
2946 return new MethodType(argtypes, restype, thrown, t.tsym);
2947 }
2949 @Override
2950 public Type visitTypeVar(TypeVar t, Void ignored) {
2951 for (List<Type> from = this.from, to = this.to;
2952 from.nonEmpty();
2953 from = from.tail, to = to.tail) {
2954 if (t == from.head) {
2955 return to.head.withTypeVar(t);
2956 }
2957 }
2958 return t;
2959 }
2961 @Override
2962 public Type visitClassType(ClassType t, Void ignored) {
2963 if (!t.isCompound()) {
2964 List<Type> typarams = t.getTypeArguments();
2965 List<Type> typarams1 = subst(typarams);
2966 Type outer = t.getEnclosingType();
2967 Type outer1 = subst(outer);
2968 if (typarams1 == typarams && outer1 == outer)
2969 return t;
2970 else
2971 return new ClassType(outer1, typarams1, t.tsym);
2972 } else {
2973 Type st = subst(supertype(t));
2974 List<Type> is = upperBounds(subst(interfaces(t)));
2975 if (st == supertype(t) && is == interfaces(t))
2976 return t;
2977 else
2978 return makeCompoundType(is.prepend(st));
2979 }
2980 }
2982 @Override
2983 public Type visitWildcardType(WildcardType t, Void ignored) {
2984 Type bound = t.type;
2985 if (t.kind != BoundKind.UNBOUND)
2986 bound = subst(bound);
2987 if (bound == t.type) {
2988 return t;
2989 } else {
2990 if (t.isExtendsBound() && bound.isExtendsBound())
2991 bound = upperBound(bound);
2992 return new WildcardType(bound, t.kind, syms.boundClass, t.bound);
2993 }
2994 }
2996 @Override
2997 public Type visitArrayType(ArrayType t, Void ignored) {
2998 Type elemtype = subst(t.elemtype);
2999 if (elemtype == t.elemtype)
3000 return t;
3001 else
3002 return new ArrayType(elemtype, t.tsym);
3003 }
3005 @Override
3006 public Type visitForAll(ForAll t, Void ignored) {
3007 if (Type.containsAny(to, t.tvars)) {
3008 //perform alpha-renaming of free-variables in 't'
3009 //if 'to' types contain variables that are free in 't'
3010 List<Type> freevars = newInstances(t.tvars);
3011 t = new ForAll(freevars,
3012 Types.this.subst(t.qtype, t.tvars, freevars));
3013 }
3014 List<Type> tvars1 = substBounds(t.tvars, from, to);
3015 Type qtype1 = subst(t.qtype);
3016 if (tvars1 == t.tvars && qtype1 == t.qtype) {
3017 return t;
3018 } else if (tvars1 == t.tvars) {
3019 return new ForAll(tvars1, qtype1);
3020 } else {
3021 return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1));
3022 }
3023 }
3025 @Override
3026 public Type visitErrorType(ErrorType t, Void ignored) {
3027 return t;
3028 }
3029 }
3031 public List<Type> substBounds(List<Type> tvars,
3032 List<Type> from,
3033 List<Type> to) {
3034 if (tvars.isEmpty())
3035 return tvars;
3036 ListBuffer<Type> newBoundsBuf = new ListBuffer<>();
3037 boolean changed = false;
3038 // calculate new bounds
3039 for (Type t : tvars) {
3040 TypeVar tv = (TypeVar) t;
3041 Type bound = subst(tv.bound, from, to);
3042 if (bound != tv.bound)
3043 changed = true;
3044 newBoundsBuf.append(bound);
3045 }
3046 if (!changed)
3047 return tvars;
3048 ListBuffer<Type> newTvars = new ListBuffer<>();
3049 // create new type variables without bounds
3050 for (Type t : tvars) {
3051 newTvars.append(new TypeVar(t.tsym, null, syms.botType));
3052 }
3053 // the new bounds should use the new type variables in place
3054 // of the old
3055 List<Type> newBounds = newBoundsBuf.toList();
3056 from = tvars;
3057 to = newTvars.toList();
3058 for (; !newBounds.isEmpty(); newBounds = newBounds.tail) {
3059 newBounds.head = subst(newBounds.head, from, to);
3060 }
3061 newBounds = newBoundsBuf.toList();
3062 // set the bounds of new type variables to the new bounds
3063 for (Type t : newTvars.toList()) {
3064 TypeVar tv = (TypeVar) t;
3065 tv.bound = newBounds.head;
3066 newBounds = newBounds.tail;
3067 }
3068 return newTvars.toList();
3069 }
3071 public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) {
3072 Type bound1 = subst(t.bound, from, to);
3073 if (bound1 == t.bound)
3074 return t;
3075 else {
3076 // create new type variable without bounds
3077 TypeVar tv = new TypeVar(t.tsym, null, syms.botType);
3078 // the new bound should use the new type variable in place
3079 // of the old
3080 tv.bound = subst(bound1, List.<Type>of(t), List.<Type>of(tv));
3081 return tv;
3082 }
3083 }
3084 // </editor-fold>
3086 // <editor-fold defaultstate="collapsed" desc="hasSameBounds">
3087 /**
3088 * Does t have the same bounds for quantified variables as s?
3089 */
3090 public boolean hasSameBounds(ForAll t, ForAll s) {
3091 List<Type> l1 = t.tvars;
3092 List<Type> l2 = s.tvars;
3093 while (l1.nonEmpty() && l2.nonEmpty() &&
3094 isSameType(l1.head.getUpperBound(),
3095 subst(l2.head.getUpperBound(),
3096 s.tvars,
3097 t.tvars))) {
3098 l1 = l1.tail;
3099 l2 = l2.tail;
3100 }
3101 return l1.isEmpty() && l2.isEmpty();
3102 }
3103 // </editor-fold>
3105 // <editor-fold defaultstate="collapsed" desc="newInstances">
3106 /** Create new vector of type variables from list of variables
3107 * changing all recursive bounds from old to new list.
3108 */
3109 public List<Type> newInstances(List<Type> tvars) {
3110 List<Type> tvars1 = Type.map(tvars, newInstanceFun);
3111 for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) {
3112 TypeVar tv = (TypeVar) l.head;
3113 tv.bound = subst(tv.bound, tvars, tvars1);
3114 }
3115 return tvars1;
3116 }
3117 private static final Mapping newInstanceFun = new Mapping("newInstanceFun") {
3118 public Type apply(Type t) { return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound()); }
3119 };
3120 // </editor-fold>
3122 public Type createMethodTypeWithParameters(Type original, List<Type> newParams) {
3123 return original.accept(methodWithParameters, newParams);
3124 }
3125 // where
3126 private final MapVisitor<List<Type>> methodWithParameters = new MapVisitor<List<Type>>() {
3127 public Type visitType(Type t, List<Type> newParams) {
3128 throw new IllegalArgumentException("Not a method type: " + t);
3129 }
3130 public Type visitMethodType(MethodType t, List<Type> newParams) {
3131 return new MethodType(newParams, t.restype, t.thrown, t.tsym);
3132 }
3133 public Type visitForAll(ForAll t, List<Type> newParams) {
3134 return new ForAll(t.tvars, t.qtype.accept(this, newParams));
3135 }
3136 };
3138 public Type createMethodTypeWithThrown(Type original, List<Type> newThrown) {
3139 return original.accept(methodWithThrown, newThrown);
3140 }
3141 // where
3142 private final MapVisitor<List<Type>> methodWithThrown = new MapVisitor<List<Type>>() {
3143 public Type visitType(Type t, List<Type> newThrown) {
3144 throw new IllegalArgumentException("Not a method type: " + t);
3145 }
3146 public Type visitMethodType(MethodType t, List<Type> newThrown) {
3147 return new MethodType(t.argtypes, t.restype, newThrown, t.tsym);
3148 }
3149 public Type visitForAll(ForAll t, List<Type> newThrown) {
3150 return new ForAll(t.tvars, t.qtype.accept(this, newThrown));
3151 }
3152 };
3154 public Type createMethodTypeWithReturn(Type original, Type newReturn) {
3155 return original.accept(methodWithReturn, newReturn);
3156 }
3157 // where
3158 private final MapVisitor<Type> methodWithReturn = new MapVisitor<Type>() {
3159 public Type visitType(Type t, Type newReturn) {
3160 throw new IllegalArgumentException("Not a method type: " + t);
3161 }
3162 public Type visitMethodType(MethodType t, Type newReturn) {
3163 return new MethodType(t.argtypes, newReturn, t.thrown, t.tsym);
3164 }
3165 public Type visitForAll(ForAll t, Type newReturn) {
3166 return new ForAll(t.tvars, t.qtype.accept(this, newReturn));
3167 }
3168 };
3170 // <editor-fold defaultstate="collapsed" desc="createErrorType">
3171 public Type createErrorType(Type originalType) {
3172 return new ErrorType(originalType, syms.errSymbol);
3173 }
3175 public Type createErrorType(ClassSymbol c, Type originalType) {
3176 return new ErrorType(c, originalType);
3177 }
3179 public Type createErrorType(Name name, TypeSymbol container, Type originalType) {
3180 return new ErrorType(name, container, originalType);
3181 }
3182 // </editor-fold>
3184 // <editor-fold defaultstate="collapsed" desc="rank">
3185 /**
3186 * The rank of a class is the length of the longest path between
3187 * the class and java.lang.Object in the class inheritance
3188 * graph. Undefined for all but reference types.
3189 */
3190 public int rank(Type t) {
3191 t = t.unannotatedType();
3192 switch(t.getTag()) {
3193 case CLASS: {
3194 ClassType cls = (ClassType)t;
3195 if (cls.rank_field < 0) {
3196 Name fullname = cls.tsym.getQualifiedName();
3197 if (fullname == names.java_lang_Object)
3198 cls.rank_field = 0;
3199 else {
3200 int r = rank(supertype(cls));
3201 for (List<Type> l = interfaces(cls);
3202 l.nonEmpty();
3203 l = l.tail) {
3204 if (rank(l.head) > r)
3205 r = rank(l.head);
3206 }
3207 cls.rank_field = r + 1;
3208 }
3209 }
3210 return cls.rank_field;
3211 }
3212 case TYPEVAR: {
3213 TypeVar tvar = (TypeVar)t;
3214 if (tvar.rank_field < 0) {
3215 int r = rank(supertype(tvar));
3216 for (List<Type> l = interfaces(tvar);
3217 l.nonEmpty();
3218 l = l.tail) {
3219 if (rank(l.head) > r) r = rank(l.head);
3220 }
3221 tvar.rank_field = r + 1;
3222 }
3223 return tvar.rank_field;
3224 }
3225 case ERROR:
3226 return 0;
3227 default:
3228 throw new AssertionError();
3229 }
3230 }
3231 // </editor-fold>
3233 /**
3234 * Helper method for generating a string representation of a given type
3235 * accordingly to a given locale
3236 */
3237 public String toString(Type t, Locale locale) {
3238 return Printer.createStandardPrinter(messages).visit(t, locale);
3239 }
3241 /**
3242 * Helper method for generating a string representation of a given type
3243 * accordingly to a given locale
3244 */
3245 public String toString(Symbol t, Locale locale) {
3246 return Printer.createStandardPrinter(messages).visit(t, locale);
3247 }
3249 // <editor-fold defaultstate="collapsed" desc="toString">
3250 /**
3251 * This toString is slightly more descriptive than the one on Type.
3252 *
3253 * @deprecated Types.toString(Type t, Locale l) provides better support
3254 * for localization
3255 */
3256 @Deprecated
3257 public String toString(Type t) {
3258 if (t.hasTag(FORALL)) {
3259 ForAll forAll = (ForAll)t;
3260 return typaramsString(forAll.tvars) + forAll.qtype;
3261 }
3262 return "" + t;
3263 }
3264 // where
3265 private String typaramsString(List<Type> tvars) {
3266 StringBuilder s = new StringBuilder();
3267 s.append('<');
3268 boolean first = true;
3269 for (Type t : tvars) {
3270 if (!first) s.append(", ");
3271 first = false;
3272 appendTyparamString(((TypeVar)t.unannotatedType()), s);
3273 }
3274 s.append('>');
3275 return s.toString();
3276 }
3277 private void appendTyparamString(TypeVar t, StringBuilder buf) {
3278 buf.append(t);
3279 if (t.bound == null ||
3280 t.bound.tsym.getQualifiedName() == names.java_lang_Object)
3281 return;
3282 buf.append(" extends "); // Java syntax; no need for i18n
3283 Type bound = t.bound;
3284 if (!bound.isCompound()) {
3285 buf.append(bound);
3286 } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) {
3287 buf.append(supertype(t));
3288 for (Type intf : interfaces(t)) {
3289 buf.append('&');
3290 buf.append(intf);
3291 }
3292 } else {
3293 // No superclass was given in bounds.
3294 // In this case, supertype is Object, erasure is first interface.
3295 boolean first = true;
3296 for (Type intf : interfaces(t)) {
3297 if (!first) buf.append('&');
3298 first = false;
3299 buf.append(intf);
3300 }
3301 }
3302 }
3303 // </editor-fold>
3305 // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types">
3306 /**
3307 * A cache for closures.
3308 *
3309 * <p>A closure is a list of all the supertypes and interfaces of
3310 * a class or interface type, ordered by ClassSymbol.precedes
3311 * (that is, subclasses come first, arbitrary but fixed
3312 * otherwise).
3313 */
3314 private Map<Type,List<Type>> closureCache = new HashMap<Type,List<Type>>();
3316 /**
3317 * Returns the closure of a class or interface type.
3318 */
3319 public List<Type> closure(Type t) {
3320 List<Type> cl = closureCache.get(t);
3321 if (cl == null) {
3322 Type st = supertype(t);
3323 if (!t.isCompound()) {
3324 if (st.hasTag(CLASS)) {
3325 cl = insert(closure(st), t);
3326 } else if (st.hasTag(TYPEVAR)) {
3327 cl = closure(st).prepend(t);
3328 } else {
3329 cl = List.of(t);
3330 }
3331 } else {
3332 cl = closure(supertype(t));
3333 }
3334 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail)
3335 cl = union(cl, closure(l.head));
3336 closureCache.put(t, cl);
3337 }
3338 return cl;
3339 }
3341 /**
3342 * Insert a type in a closure
3343 */
3344 public List<Type> insert(List<Type> cl, Type t) {
3345 if (cl.isEmpty() || t.tsym.precedes(cl.head.tsym, this)) {
3346 return cl.prepend(t);
3347 } else if (cl.head.tsym.precedes(t.tsym, this)) {
3348 return insert(cl.tail, t).prepend(cl.head);
3349 } else {
3350 return cl;
3351 }
3352 }
3354 /**
3355 * Form the union of two closures
3356 */
3357 public List<Type> union(List<Type> cl1, List<Type> cl2) {
3358 if (cl1.isEmpty()) {
3359 return cl2;
3360 } else if (cl2.isEmpty()) {
3361 return cl1;
3362 } else if (cl1.head.tsym.precedes(cl2.head.tsym, this)) {
3363 return union(cl1.tail, cl2).prepend(cl1.head);
3364 } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) {
3365 return union(cl1, cl2.tail).prepend(cl2.head);
3366 } else {
3367 return union(cl1.tail, cl2.tail).prepend(cl1.head);
3368 }
3369 }
3371 /**
3372 * Intersect two closures
3373 */
3374 public List<Type> intersect(List<Type> cl1, List<Type> cl2) {
3375 if (cl1 == cl2)
3376 return cl1;
3377 if (cl1.isEmpty() || cl2.isEmpty())
3378 return List.nil();
3379 if (cl1.head.tsym.precedes(cl2.head.tsym, this))
3380 return intersect(cl1.tail, cl2);
3381 if (cl2.head.tsym.precedes(cl1.head.tsym, this))
3382 return intersect(cl1, cl2.tail);
3383 if (isSameType(cl1.head, cl2.head))
3384 return intersect(cl1.tail, cl2.tail).prepend(cl1.head);
3385 if (cl1.head.tsym == cl2.head.tsym &&
3386 cl1.head.hasTag(CLASS) && cl2.head.hasTag(CLASS)) {
3387 if (cl1.head.isParameterized() && cl2.head.isParameterized()) {
3388 Type merge = merge(cl1.head,cl2.head);
3389 return intersect(cl1.tail, cl2.tail).prepend(merge);
3390 }
3391 if (cl1.head.isRaw() || cl2.head.isRaw())
3392 return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head));
3393 }
3394 return intersect(cl1.tail, cl2.tail);
3395 }
3396 // where
3397 class TypePair {
3398 final Type t1;
3399 final Type t2;
3400 TypePair(Type t1, Type t2) {
3401 this.t1 = t1;
3402 this.t2 = t2;
3403 }
3404 @Override
3405 public int hashCode() {
3406 return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2);
3407 }
3408 @Override
3409 public boolean equals(Object obj) {
3410 if (!(obj instanceof TypePair))
3411 return false;
3412 TypePair typePair = (TypePair)obj;
3413 return isSameType(t1, typePair.t1)
3414 && isSameType(t2, typePair.t2);
3415 }
3416 }
3417 Set<TypePair> mergeCache = new HashSet<TypePair>();
3418 private Type merge(Type c1, Type c2) {
3419 ClassType class1 = (ClassType) c1;
3420 List<Type> act1 = class1.getTypeArguments();
3421 ClassType class2 = (ClassType) c2;
3422 List<Type> act2 = class2.getTypeArguments();
3423 ListBuffer<Type> merged = new ListBuffer<Type>();
3424 List<Type> typarams = class1.tsym.type.getTypeArguments();
3426 while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) {
3427 if (containsType(act1.head, act2.head)) {
3428 merged.append(act1.head);
3429 } else if (containsType(act2.head, act1.head)) {
3430 merged.append(act2.head);
3431 } else {
3432 TypePair pair = new TypePair(c1, c2);
3433 Type m;
3434 if (mergeCache.add(pair)) {
3435 m = new WildcardType(lub(upperBound(act1.head),
3436 upperBound(act2.head)),
3437 BoundKind.EXTENDS,
3438 syms.boundClass);
3439 mergeCache.remove(pair);
3440 } else {
3441 m = new WildcardType(syms.objectType,
3442 BoundKind.UNBOUND,
3443 syms.boundClass);
3444 }
3445 merged.append(m.withTypeVar(typarams.head));
3446 }
3447 act1 = act1.tail;
3448 act2 = act2.tail;
3449 typarams = typarams.tail;
3450 }
3451 Assert.check(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty());
3452 return new ClassType(class1.getEnclosingType(), merged.toList(), class1.tsym);
3453 }
3455 /**
3456 * Return the minimum type of a closure, a compound type if no
3457 * unique minimum exists.
3458 */
3459 private Type compoundMin(List<Type> cl) {
3460 if (cl.isEmpty()) return syms.objectType;
3461 List<Type> compound = closureMin(cl);
3462 if (compound.isEmpty())
3463 return null;
3464 else if (compound.tail.isEmpty())
3465 return compound.head;
3466 else
3467 return makeCompoundType(compound);
3468 }
3470 /**
3471 * Return the minimum types of a closure, suitable for computing
3472 * compoundMin or glb.
3473 */
3474 private List<Type> closureMin(List<Type> cl) {
3475 ListBuffer<Type> classes = new ListBuffer<>();
3476 ListBuffer<Type> interfaces = new ListBuffer<>();
3477 while (!cl.isEmpty()) {
3478 Type current = cl.head;
3479 if (current.isInterface())
3480 interfaces.append(current);
3481 else
3482 classes.append(current);
3483 ListBuffer<Type> candidates = new ListBuffer<>();
3484 for (Type t : cl.tail) {
3485 if (!isSubtypeNoCapture(current, t))
3486 candidates.append(t);
3487 }
3488 cl = candidates.toList();
3489 }
3490 return classes.appendList(interfaces).toList();
3491 }
3493 /**
3494 * Return the least upper bound of pair of types. if the lub does
3495 * not exist return null.
3496 */
3497 public Type lub(Type t1, Type t2) {
3498 return lub(List.of(t1, t2));
3499 }
3501 /**
3502 * Return the least upper bound (lub) of set of types. If the lub
3503 * does not exist return the type of null (bottom).
3504 */
3505 public Type lub(List<Type> ts) {
3506 final int ARRAY_BOUND = 1;
3507 final int CLASS_BOUND = 2;
3508 int boundkind = 0;
3509 for (Type t : ts) {
3510 switch (t.getTag()) {
3511 case CLASS:
3512 boundkind |= CLASS_BOUND;
3513 break;
3514 case ARRAY:
3515 boundkind |= ARRAY_BOUND;
3516 break;
3517 case TYPEVAR:
3518 do {
3519 t = t.getUpperBound();
3520 } while (t.hasTag(TYPEVAR));
3521 if (t.hasTag(ARRAY)) {
3522 boundkind |= ARRAY_BOUND;
3523 } else {
3524 boundkind |= CLASS_BOUND;
3525 }
3526 break;
3527 default:
3528 if (t.isPrimitive())
3529 return syms.errType;
3530 }
3531 }
3532 switch (boundkind) {
3533 case 0:
3534 return syms.botType;
3536 case ARRAY_BOUND:
3537 // calculate lub(A[], B[])
3538 List<Type> elements = Type.map(ts, elemTypeFun);
3539 for (Type t : elements) {
3540 if (t.isPrimitive()) {
3541 // if a primitive type is found, then return
3542 // arraySuperType unless all the types are the
3543 // same
3544 Type first = ts.head;
3545 for (Type s : ts.tail) {
3546 if (!isSameType(first, s)) {
3547 // lub(int[], B[]) is Cloneable & Serializable
3548 return arraySuperType();
3549 }
3550 }
3551 // all the array types are the same, return one
3552 // lub(int[], int[]) is int[]
3553 return first;
3554 }
3555 }
3556 // lub(A[], B[]) is lub(A, B)[]
3557 return new ArrayType(lub(elements), syms.arrayClass);
3559 case CLASS_BOUND:
3560 // calculate lub(A, B)
3561 while (!ts.head.hasTag(CLASS) && !ts.head.hasTag(TYPEVAR)) {
3562 ts = ts.tail;
3563 }
3564 Assert.check(!ts.isEmpty());
3565 //step 1 - compute erased candidate set (EC)
3566 List<Type> cl = erasedSupertypes(ts.head);
3567 for (Type t : ts.tail) {
3568 if (t.hasTag(CLASS) || t.hasTag(TYPEVAR))
3569 cl = intersect(cl, erasedSupertypes(t));
3570 }
3571 //step 2 - compute minimal erased candidate set (MEC)
3572 List<Type> mec = closureMin(cl);
3573 //step 3 - for each element G in MEC, compute lci(Inv(G))
3574 List<Type> candidates = List.nil();
3575 for (Type erasedSupertype : mec) {
3576 List<Type> lci = List.of(asSuper(ts.head, erasedSupertype));
3577 for (Type t : ts) {
3578 lci = intersect(lci, List.of(asSuper(t, erasedSupertype)));
3579 }
3580 candidates = candidates.appendList(lci);
3581 }
3582 //step 4 - let MEC be { G1, G2 ... Gn }, then we have that
3583 //lub = lci(Inv(G1)) & lci(Inv(G2)) & ... & lci(Inv(Gn))
3584 return compoundMin(candidates);
3586 default:
3587 // calculate lub(A, B[])
3588 List<Type> classes = List.of(arraySuperType());
3589 for (Type t : ts) {
3590 if (!t.hasTag(ARRAY)) // Filter out any arrays
3591 classes = classes.prepend(t);
3592 }
3593 // lub(A, B[]) is lub(A, arraySuperType)
3594 return lub(classes);
3595 }
3596 }
3597 // where
3598 List<Type> erasedSupertypes(Type t) {
3599 ListBuffer<Type> buf = new ListBuffer<>();
3600 for (Type sup : closure(t)) {
3601 if (sup.hasTag(TYPEVAR)) {
3602 buf.append(sup);
3603 } else {
3604 buf.append(erasure(sup));
3605 }
3606 }
3607 return buf.toList();
3608 }
3610 private Type arraySuperType = null;
3611 private Type arraySuperType() {
3612 // initialized lazily to avoid problems during compiler startup
3613 if (arraySuperType == null) {
3614 synchronized (this) {
3615 if (arraySuperType == null) {
3616 // JLS 10.8: all arrays implement Cloneable and Serializable.
3617 arraySuperType = makeCompoundType(List.of(syms.serializableType,
3618 syms.cloneableType), true);
3619 }
3620 }
3621 }
3622 return arraySuperType;
3623 }
3624 // </editor-fold>
3626 // <editor-fold defaultstate="collapsed" desc="Greatest lower bound">
3627 public Type glb(List<Type> ts) {
3628 Type t1 = ts.head;
3629 for (Type t2 : ts.tail) {
3630 if (t1.isErroneous())
3631 return t1;
3632 t1 = glb(t1, t2);
3633 }
3634 return t1;
3635 }
3636 //where
3637 public Type glb(Type t, Type s) {
3638 if (s == null)
3639 return t;
3640 else if (t.isPrimitive() || s.isPrimitive())
3641 return syms.errType;
3642 else if (isSubtypeNoCapture(t, s))
3643 return t;
3644 else if (isSubtypeNoCapture(s, t))
3645 return s;
3647 List<Type> closure = union(closure(t), closure(s));
3648 List<Type> bounds = closureMin(closure);
3650 if (bounds.isEmpty()) { // length == 0
3651 return syms.objectType;
3652 } else if (bounds.tail.isEmpty()) { // length == 1
3653 return bounds.head;
3654 } else { // length > 1
3655 int classCount = 0;
3656 for (Type bound : bounds)
3657 if (!bound.isInterface())
3658 classCount++;
3659 if (classCount > 1)
3660 return createErrorType(t);
3661 }
3662 return makeCompoundType(bounds);
3663 }
3664 // </editor-fold>
3666 // <editor-fold defaultstate="collapsed" desc="hashCode">
3667 /**
3668 * Compute a hash code on a type.
3669 */
3670 public int hashCode(Type t) {
3671 return hashCode.visit(t);
3672 }
3673 // where
3674 private static final UnaryVisitor<Integer> hashCode = new UnaryVisitor<Integer>() {
3676 public Integer visitType(Type t, Void ignored) {
3677 return t.getTag().ordinal();
3678 }
3680 @Override
3681 public Integer visitClassType(ClassType t, Void ignored) {
3682 int result = visit(t.getEnclosingType());
3683 result *= 127;
3684 result += t.tsym.flatName().hashCode();
3685 for (Type s : t.getTypeArguments()) {
3686 result *= 127;
3687 result += visit(s);
3688 }
3689 return result;
3690 }
3692 @Override
3693 public Integer visitMethodType(MethodType t, Void ignored) {
3694 int h = METHOD.ordinal();
3695 for (List<Type> thisargs = t.argtypes;
3696 thisargs.tail != null;
3697 thisargs = thisargs.tail)
3698 h = (h << 5) + visit(thisargs.head);
3699 return (h << 5) + visit(t.restype);
3700 }
3702 @Override
3703 public Integer visitWildcardType(WildcardType t, Void ignored) {
3704 int result = t.kind.hashCode();
3705 if (t.type != null) {
3706 result *= 127;
3707 result += visit(t.type);
3708 }
3709 return result;
3710 }
3712 @Override
3713 public Integer visitArrayType(ArrayType t, Void ignored) {
3714 return visit(t.elemtype) + 12;
3715 }
3717 @Override
3718 public Integer visitTypeVar(TypeVar t, Void ignored) {
3719 return System.identityHashCode(t.tsym);
3720 }
3722 @Override
3723 public Integer visitUndetVar(UndetVar t, Void ignored) {
3724 return System.identityHashCode(t);
3725 }
3727 @Override
3728 public Integer visitErrorType(ErrorType t, Void ignored) {
3729 return 0;
3730 }
3731 };
3732 // </editor-fold>
3734 // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable">
3735 /**
3736 * Does t have a result that is a subtype of the result type of s,
3737 * suitable for covariant returns? It is assumed that both types
3738 * are (possibly polymorphic) method types. Monomorphic method
3739 * types are handled in the obvious way. Polymorphic method types
3740 * require renaming all type variables of one to corresponding
3741 * type variables in the other, where correspondence is by
3742 * position in the type parameter list. */
3743 public boolean resultSubtype(Type t, Type s, Warner warner) {
3744 List<Type> tvars = t.getTypeArguments();
3745 List<Type> svars = s.getTypeArguments();
3746 Type tres = t.getReturnType();
3747 Type sres = subst(s.getReturnType(), svars, tvars);
3748 return covariantReturnType(tres, sres, warner);
3749 }
3751 /**
3752 * Return-Type-Substitutable.
3753 * @jls section 8.4.5
3754 */
3755 public boolean returnTypeSubstitutable(Type r1, Type r2) {
3756 if (hasSameArgs(r1, r2))
3757 return resultSubtype(r1, r2, noWarnings);
3758 else
3759 return covariantReturnType(r1.getReturnType(),
3760 erasure(r2.getReturnType()),
3761 noWarnings);
3762 }
3764 public boolean returnTypeSubstitutable(Type r1,
3765 Type r2, Type r2res,
3766 Warner warner) {
3767 if (isSameType(r1.getReturnType(), r2res))
3768 return true;
3769 if (r1.getReturnType().isPrimitive() || r2res.isPrimitive())
3770 return false;
3772 if (hasSameArgs(r1, r2))
3773 return covariantReturnType(r1.getReturnType(), r2res, warner);
3774 if (!allowCovariantReturns)
3775 return false;
3776 if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner))
3777 return true;
3778 if (!isSubtype(r1.getReturnType(), erasure(r2res)))
3779 return false;
3780 warner.warn(LintCategory.UNCHECKED);
3781 return true;
3782 }
3784 /**
3785 * Is t an appropriate return type in an overrider for a
3786 * method that returns s?
3787 */
3788 public boolean covariantReturnType(Type t, Type s, Warner warner) {
3789 return
3790 isSameType(t, s) ||
3791 allowCovariantReturns &&
3792 !t.isPrimitive() &&
3793 !s.isPrimitive() &&
3794 isAssignable(t, s, warner);
3795 }
3796 // </editor-fold>
3798 // <editor-fold defaultstate="collapsed" desc="Box/unbox support">
3799 /**
3800 * Return the class that boxes the given primitive.
3801 */
3802 public ClassSymbol boxedClass(Type t) {
3803 return reader.enterClass(syms.boxedName[t.getTag().ordinal()]);
3804 }
3806 /**
3807 * Return the boxed type if 't' is primitive, otherwise return 't' itself.
3808 */
3809 public Type boxedTypeOrType(Type t) {
3810 return t.isPrimitive() ?
3811 boxedClass(t).type :
3812 t;
3813 }
3815 /**
3816 * Return the primitive type corresponding to a boxed type.
3817 */
3818 public Type unboxedType(Type t) {
3819 if (allowBoxing) {
3820 for (int i=0; i<syms.boxedName.length; i++) {
3821 Name box = syms.boxedName[i];
3822 if (box != null &&
3823 asSuper(t, reader.enterClass(box)) != null)
3824 return syms.typeOfTag[i];
3825 }
3826 }
3827 return Type.noType;
3828 }
3830 /**
3831 * Return the unboxed type if 't' is a boxed class, otherwise return 't' itself.
3832 */
3833 public Type unboxedTypeOrType(Type t) {
3834 Type unboxedType = unboxedType(t);
3835 return unboxedType.hasTag(NONE) ? t : unboxedType;
3836 }
3837 // </editor-fold>
3839 // <editor-fold defaultstate="collapsed" desc="Capture conversion">
3840 /*
3841 * JLS 5.1.10 Capture Conversion:
3842 *
3843 * Let G name a generic type declaration with n formal type
3844 * parameters A1 ... An with corresponding bounds U1 ... Un. There
3845 * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>,
3846 * where, for 1 <= i <= n:
3847 *
3848 * + If Ti is a wildcard type argument (4.5.1) of the form ? then
3849 * Si is a fresh type variable whose upper bound is
3850 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null
3851 * type.
3852 *
3853 * + If Ti is a wildcard type argument of the form ? extends Bi,
3854 * then Si is a fresh type variable whose upper bound is
3855 * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is
3856 * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is
3857 * a compile-time error if for any two classes (not interfaces)
3858 * Vi and Vj,Vi is not a subclass of Vj or vice versa.
3859 *
3860 * + If Ti is a wildcard type argument of the form ? super Bi,
3861 * then Si is a fresh type variable whose upper bound is
3862 * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi.
3863 *
3864 * + Otherwise, Si = Ti.
3865 *
3866 * Capture conversion on any type other than a parameterized type
3867 * (4.5) acts as an identity conversion (5.1.1). Capture
3868 * conversions never require a special action at run time and
3869 * therefore never throw an exception at run time.
3870 *
3871 * Capture conversion is not applied recursively.
3872 */
3873 /**
3874 * Capture conversion as specified by the JLS.
3875 */
3877 public List<Type> capture(List<Type> ts) {
3878 List<Type> buf = List.nil();
3879 for (Type t : ts) {
3880 buf = buf.prepend(capture(t));
3881 }
3882 return buf.reverse();
3883 }
3884 public Type capture(Type t) {
3885 if (!t.hasTag(CLASS))
3886 return t;
3887 if (t.getEnclosingType() != Type.noType) {
3888 Type capturedEncl = capture(t.getEnclosingType());
3889 if (capturedEncl != t.getEnclosingType()) {
3890 Type type1 = memberType(capturedEncl, t.tsym);
3891 t = subst(type1, t.tsym.type.getTypeArguments(), t.getTypeArguments());
3892 }
3893 }
3894 t = t.unannotatedType();
3895 ClassType cls = (ClassType)t;
3896 if (cls.isRaw() || !cls.isParameterized())
3897 return cls;
3899 ClassType G = (ClassType)cls.asElement().asType();
3900 List<Type> A = G.getTypeArguments();
3901 List<Type> T = cls.getTypeArguments();
3902 List<Type> S = freshTypeVariables(T);
3904 List<Type> currentA = A;
3905 List<Type> currentT = T;
3906 List<Type> currentS = S;
3907 boolean captured = false;
3908 while (!currentA.isEmpty() &&
3909 !currentT.isEmpty() &&
3910 !currentS.isEmpty()) {
3911 if (currentS.head != currentT.head) {
3912 captured = true;
3913 WildcardType Ti = (WildcardType)currentT.head.unannotatedType();
3914 Type Ui = currentA.head.getUpperBound();
3915 CapturedType Si = (CapturedType)currentS.head.unannotatedType();
3916 if (Ui == null)
3917 Ui = syms.objectType;
3918 switch (Ti.kind) {
3919 case UNBOUND:
3920 Si.bound = subst(Ui, A, S);
3921 Si.lower = syms.botType;
3922 break;
3923 case EXTENDS:
3924 Si.bound = glb(Ti.getExtendsBound(), subst(Ui, A, S));
3925 Si.lower = syms.botType;
3926 break;
3927 case SUPER:
3928 Si.bound = subst(Ui, A, S);
3929 Si.lower = Ti.getSuperBound();
3930 break;
3931 }
3932 if (Si.bound == Si.lower)
3933 currentS.head = Si.bound;
3934 }
3935 currentA = currentA.tail;
3936 currentT = currentT.tail;
3937 currentS = currentS.tail;
3938 }
3939 if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty())
3940 return erasure(t); // some "rare" type involved
3942 if (captured)
3943 return new ClassType(cls.getEnclosingType(), S, cls.tsym);
3944 else
3945 return t;
3946 }
3947 // where
3948 public List<Type> freshTypeVariables(List<Type> types) {
3949 ListBuffer<Type> result = new ListBuffer<>();
3950 for (Type t : types) {
3951 if (t.hasTag(WILDCARD)) {
3952 t = t.unannotatedType();
3953 Type bound = ((WildcardType)t).getExtendsBound();
3954 if (bound == null)
3955 bound = syms.objectType;
3956 result.append(new CapturedType(capturedName,
3957 syms.noSymbol,
3958 bound,
3959 syms.botType,
3960 (WildcardType)t));
3961 } else {
3962 result.append(t);
3963 }
3964 }
3965 return result.toList();
3966 }
3967 // </editor-fold>
3969 // <editor-fold defaultstate="collapsed" desc="Internal utility methods">
3970 private List<Type> upperBounds(List<Type> ss) {
3971 if (ss.isEmpty()) return ss;
3972 Type head = upperBound(ss.head);
3973 List<Type> tail = upperBounds(ss.tail);
3974 if (head != ss.head || tail != ss.tail)
3975 return tail.prepend(head);
3976 else
3977 return ss;
3978 }
3980 private boolean sideCast(Type from, Type to, Warner warn) {
3981 // We are casting from type $from$ to type $to$, which are
3982 // non-final unrelated types. This method
3983 // tries to reject a cast by transferring type parameters
3984 // from $to$ to $from$ by common superinterfaces.
3985 boolean reverse = false;
3986 Type target = to;
3987 if ((to.tsym.flags() & INTERFACE) == 0) {
3988 Assert.check((from.tsym.flags() & INTERFACE) != 0);
3989 reverse = true;
3990 to = from;
3991 from = target;
3992 }
3993 List<Type> commonSupers = superClosure(to, erasure(from));
3994 boolean giveWarning = commonSupers.isEmpty();
3995 // The arguments to the supers could be unified here to
3996 // get a more accurate analysis
3997 while (commonSupers.nonEmpty()) {
3998 Type t1 = asSuper(from, commonSupers.head);
3999 Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym);
4000 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4001 return false;
4002 giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2));
4003 commonSupers = commonSupers.tail;
4004 }
4005 if (giveWarning && !isReifiable(reverse ? from : to))
4006 warn.warn(LintCategory.UNCHECKED);
4007 if (!allowCovariantReturns)
4008 // reject if there is a common method signature with
4009 // incompatible return types.
4010 chk.checkCompatibleAbstracts(warn.pos(), from, to);
4011 return true;
4012 }
4014 private boolean sideCastFinal(Type from, Type to, Warner warn) {
4015 // We are casting from type $from$ to type $to$, which are
4016 // unrelated types one of which is final and the other of
4017 // which is an interface. This method
4018 // tries to reject a cast by transferring type parameters
4019 // from the final class to the interface.
4020 boolean reverse = false;
4021 Type target = to;
4022 if ((to.tsym.flags() & INTERFACE) == 0) {
4023 Assert.check((from.tsym.flags() & INTERFACE) != 0);
4024 reverse = true;
4025 to = from;
4026 from = target;
4027 }
4028 Assert.check((from.tsym.flags() & FINAL) != 0);
4029 Type t1 = asSuper(from, to);
4030 if (t1 == null) return false;
4031 Type t2 = to;
4032 if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments()))
4033 return false;
4034 if (!allowCovariantReturns)
4035 // reject if there is a common method signature with
4036 // incompatible return types.
4037 chk.checkCompatibleAbstracts(warn.pos(), from, to);
4038 if (!isReifiable(target) &&
4039 (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)))
4040 warn.warn(LintCategory.UNCHECKED);
4041 return true;
4042 }
4044 private boolean giveWarning(Type from, Type to) {
4045 List<Type> bounds = to.isCompound() ?
4046 ((IntersectionClassType)to.unannotatedType()).getComponents() : List.of(to);
4047 for (Type b : bounds) {
4048 Type subFrom = asSub(from, b.tsym);
4049 if (b.isParameterized() &&
4050 (!(isUnbounded(b) ||
4051 isSubtype(from, b) ||
4052 ((subFrom != null) && containsType(b.allparams(), subFrom.allparams()))))) {
4053 return true;
4054 }
4055 }
4056 return false;
4057 }
4059 private List<Type> superClosure(Type t, Type s) {
4060 List<Type> cl = List.nil();
4061 for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) {
4062 if (isSubtype(s, erasure(l.head))) {
4063 cl = insert(cl, l.head);
4064 } else {
4065 cl = union(cl, superClosure(l.head, s));
4066 }
4067 }
4068 return cl;
4069 }
4071 private boolean containsTypeEquivalent(Type t, Type s) {
4072 return
4073 isSameType(t, s) || // shortcut
4074 containsType(t, s) && containsType(s, t);
4075 }
4077 // <editor-fold defaultstate="collapsed" desc="adapt">
4078 /**
4079 * Adapt a type by computing a substitution which maps a source
4080 * type to a target type.
4081 *
4082 * @param source the source type
4083 * @param target the target type
4084 * @param from the type variables of the computed substitution
4085 * @param to the types of the computed substitution.
4086 */
4087 public void adapt(Type source,
4088 Type target,
4089 ListBuffer<Type> from,
4090 ListBuffer<Type> to) throws AdaptFailure {
4091 new Adapter(from, to).adapt(source, target);
4092 }
4094 class Adapter extends SimpleVisitor<Void, Type> {
4096 ListBuffer<Type> from;
4097 ListBuffer<Type> to;
4098 Map<Symbol,Type> mapping;
4100 Adapter(ListBuffer<Type> from, ListBuffer<Type> to) {
4101 this.from = from;
4102 this.to = to;
4103 mapping = new HashMap<Symbol,Type>();
4104 }
4106 public void adapt(Type source, Type target) throws AdaptFailure {
4107 visit(source, target);
4108 List<Type> fromList = from.toList();
4109 List<Type> toList = to.toList();
4110 while (!fromList.isEmpty()) {
4111 Type val = mapping.get(fromList.head.tsym);
4112 if (toList.head != val)
4113 toList.head = val;
4114 fromList = fromList.tail;
4115 toList = toList.tail;
4116 }
4117 }
4119 @Override
4120 public Void visitClassType(ClassType source, Type target) throws AdaptFailure {
4121 if (target.hasTag(CLASS))
4122 adaptRecursive(source.allparams(), target.allparams());
4123 return null;
4124 }
4126 @Override
4127 public Void visitArrayType(ArrayType source, Type target) throws AdaptFailure {
4128 if (target.hasTag(ARRAY))
4129 adaptRecursive(elemtype(source), elemtype(target));
4130 return null;
4131 }
4133 @Override
4134 public Void visitWildcardType(WildcardType source, Type target) throws AdaptFailure {
4135 if (source.isExtendsBound())
4136 adaptRecursive(upperBound(source), upperBound(target));
4137 else if (source.isSuperBound())
4138 adaptRecursive(lowerBound(source), lowerBound(target));
4139 return null;
4140 }
4142 @Override
4143 public Void visitTypeVar(TypeVar source, Type target) throws AdaptFailure {
4144 // Check to see if there is
4145 // already a mapping for $source$, in which case
4146 // the old mapping will be merged with the new
4147 Type val = mapping.get(source.tsym);
4148 if (val != null) {
4149 if (val.isSuperBound() && target.isSuperBound()) {
4150 val = isSubtype(lowerBound(val), lowerBound(target))
4151 ? target : val;
4152 } else if (val.isExtendsBound() && target.isExtendsBound()) {
4153 val = isSubtype(upperBound(val), upperBound(target))
4154 ? val : target;
4155 } else if (!isSameType(val, target)) {
4156 throw new AdaptFailure();
4157 }
4158 } else {
4159 val = target;
4160 from.append(source);
4161 to.append(target);
4162 }
4163 mapping.put(source.tsym, val);
4164 return null;
4165 }
4167 @Override
4168 public Void visitType(Type source, Type target) {
4169 return null;
4170 }
4172 private Set<TypePair> cache = new HashSet<TypePair>();
4174 private void adaptRecursive(Type source, Type target) {
4175 TypePair pair = new TypePair(source, target);
4176 if (cache.add(pair)) {
4177 try {
4178 visit(source, target);
4179 } finally {
4180 cache.remove(pair);
4181 }
4182 }
4183 }
4185 private void adaptRecursive(List<Type> source, List<Type> target) {
4186 if (source.length() == target.length()) {
4187 while (source.nonEmpty()) {
4188 adaptRecursive(source.head, target.head);
4189 source = source.tail;
4190 target = target.tail;
4191 }
4192 }
4193 }
4194 }
4196 public static class AdaptFailure extends RuntimeException {
4197 static final long serialVersionUID = -7490231548272701566L;
4198 }
4200 private void adaptSelf(Type t,
4201 ListBuffer<Type> from,
4202 ListBuffer<Type> to) {
4203 try {
4204 //if (t.tsym.type != t)
4205 adapt(t.tsym.type, t, from, to);
4206 } catch (AdaptFailure ex) {
4207 // Adapt should never fail calculating a mapping from
4208 // t.tsym.type to t as there can be no merge problem.
4209 throw new AssertionError(ex);
4210 }
4211 }
4212 // </editor-fold>
4214 /**
4215 * Rewrite all type variables (universal quantifiers) in the given
4216 * type to wildcards (existential quantifiers). This is used to
4217 * determine if a cast is allowed. For example, if high is true
4218 * and {@code T <: Number}, then {@code List<T>} is rewritten to
4219 * {@code List<? extends Number>}. Since {@code List<Integer> <:
4220 * List<? extends Number>} a {@code List<T>} can be cast to {@code
4221 * List<Integer>} with a warning.
4222 * @param t a type
4223 * @param high if true return an upper bound; otherwise a lower
4224 * bound
4225 * @param rewriteTypeVars only rewrite captured wildcards if false;
4226 * otherwise rewrite all type variables
4227 * @return the type rewritten with wildcards (existential
4228 * quantifiers) only
4229 */
4230 private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) {
4231 return new Rewriter(high, rewriteTypeVars).visit(t);
4232 }
4234 class Rewriter extends UnaryVisitor<Type> {
4236 boolean high;
4237 boolean rewriteTypeVars;
4239 Rewriter(boolean high, boolean rewriteTypeVars) {
4240 this.high = high;
4241 this.rewriteTypeVars = rewriteTypeVars;
4242 }
4244 @Override
4245 public Type visitClassType(ClassType t, Void s) {
4246 ListBuffer<Type> rewritten = new ListBuffer<Type>();
4247 boolean changed = false;
4248 for (Type arg : t.allparams()) {
4249 Type bound = visit(arg);
4250 if (arg != bound) {
4251 changed = true;
4252 }
4253 rewritten.append(bound);
4254 }
4255 if (changed)
4256 return subst(t.tsym.type,
4257 t.tsym.type.allparams(),
4258 rewritten.toList());
4259 else
4260 return t;
4261 }
4263 public Type visitType(Type t, Void s) {
4264 return high ? upperBound(t) : lowerBound(t);
4265 }
4267 @Override
4268 public Type visitCapturedType(CapturedType t, Void s) {
4269 Type w_bound = t.wildcard.type;
4270 Type bound = w_bound.contains(t) ?
4271 erasure(w_bound) :
4272 visit(w_bound);
4273 return rewriteAsWildcardType(visit(bound), t.wildcard.bound, t.wildcard.kind);
4274 }
4276 @Override
4277 public Type visitTypeVar(TypeVar t, Void s) {
4278 if (rewriteTypeVars) {
4279 Type bound = t.bound.contains(t) ?
4280 erasure(t.bound) :
4281 visit(t.bound);
4282 return rewriteAsWildcardType(bound, t, EXTENDS);
4283 } else {
4284 return t;
4285 }
4286 }
4288 @Override
4289 public Type visitWildcardType(WildcardType t, Void s) {
4290 Type bound2 = visit(t.type);
4291 return t.type == bound2 ? t : rewriteAsWildcardType(bound2, t.bound, t.kind);
4292 }
4294 private Type rewriteAsWildcardType(Type bound, TypeVar formal, BoundKind bk) {
4295 switch (bk) {
4296 case EXTENDS: return high ?
4297 makeExtendsWildcard(B(bound), formal) :
4298 makeExtendsWildcard(syms.objectType, formal);
4299 case SUPER: return high ?
4300 makeSuperWildcard(syms.botType, formal) :
4301 makeSuperWildcard(B(bound), formal);
4302 case UNBOUND: return makeExtendsWildcard(syms.objectType, formal);
4303 default:
4304 Assert.error("Invalid bound kind " + bk);
4305 return null;
4306 }
4307 }
4309 Type B(Type t) {
4310 while (t.hasTag(WILDCARD)) {
4311 WildcardType w = (WildcardType)t.unannotatedType();
4312 t = high ?
4313 w.getExtendsBound() :
4314 w.getSuperBound();
4315 if (t == null) {
4316 t = high ? syms.objectType : syms.botType;
4317 }
4318 }
4319 return t;
4320 }
4321 }
4324 /**
4325 * Create a wildcard with the given upper (extends) bound; create
4326 * an unbounded wildcard if bound is Object.
4327 *
4328 * @param bound the upper bound
4329 * @param formal the formal type parameter that will be
4330 * substituted by the wildcard
4331 */
4332 private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) {
4333 if (bound == syms.objectType) {
4334 return new WildcardType(syms.objectType,
4335 BoundKind.UNBOUND,
4336 syms.boundClass,
4337 formal);
4338 } else {
4339 return new WildcardType(bound,
4340 BoundKind.EXTENDS,
4341 syms.boundClass,
4342 formal);
4343 }
4344 }
4346 /**
4347 * Create a wildcard with the given lower (super) bound; create an
4348 * unbounded wildcard if bound is bottom (type of {@code null}).
4349 *
4350 * @param bound the lower bound
4351 * @param formal the formal type parameter that will be
4352 * substituted by the wildcard
4353 */
4354 private WildcardType makeSuperWildcard(Type bound, TypeVar formal) {
4355 if (bound.hasTag(BOT)) {
4356 return new WildcardType(syms.objectType,
4357 BoundKind.UNBOUND,
4358 syms.boundClass,
4359 formal);
4360 } else {
4361 return new WildcardType(bound,
4362 BoundKind.SUPER,
4363 syms.boundClass,
4364 formal);
4365 }
4366 }
4368 /**
4369 * A wrapper for a type that allows use in sets.
4370 */
4371 public static class UniqueType {
4372 public final Type type;
4373 final Types types;
4375 public UniqueType(Type type, Types types) {
4376 this.type = type;
4377 this.types = types;
4378 }
4380 public int hashCode() {
4381 return types.hashCode(type);
4382 }
4384 public boolean equals(Object obj) {
4385 return (obj instanceof UniqueType) &&
4386 types.isSameAnnotatedType(type, ((UniqueType)obj).type);
4387 }
4389 public String toString() {
4390 return type.toString();
4391 }
4393 }
4394 // </editor-fold>
4396 // <editor-fold defaultstate="collapsed" desc="Visitors">
4397 /**
4398 * A default visitor for types. All visitor methods except
4399 * visitType are implemented by delegating to visitType. Concrete
4400 * subclasses must provide an implementation of visitType and can
4401 * override other methods as needed.
4402 *
4403 * @param <R> the return type of the operation implemented by this
4404 * visitor; use Void if no return type is needed.
4405 * @param <S> the type of the second argument (the first being the
4406 * type itself) of the operation implemented by this visitor; use
4407 * Void if a second argument is not needed.
4408 */
4409 public static abstract class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> {
4410 final public R visit(Type t, S s) { return t.accept(this, s); }
4411 public R visitClassType(ClassType t, S s) { return visitType(t, s); }
4412 public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); }
4413 public R visitArrayType(ArrayType t, S s) { return visitType(t, s); }
4414 public R visitMethodType(MethodType t, S s) { return visitType(t, s); }
4415 public R visitPackageType(PackageType t, S s) { return visitType(t, s); }
4416 public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); }
4417 public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); }
4418 public R visitForAll(ForAll t, S s) { return visitType(t, s); }
4419 public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); }
4420 public R visitErrorType(ErrorType t, S s) { return visitType(t, s); }
4421 // Pretend annotations don't exist
4422 public R visitAnnotatedType(AnnotatedType t, S s) { return visit(t.unannotatedType(), s); }
4423 }
4425 /**
4426 * A default visitor for symbols. All visitor methods except
4427 * visitSymbol are implemented by delegating to visitSymbol. Concrete
4428 * subclasses must provide an implementation of visitSymbol and can
4429 * override other methods as needed.
4430 *
4431 * @param <R> the return type of the operation implemented by this
4432 * visitor; use Void if no return type is needed.
4433 * @param <S> the type of the second argument (the first being the
4434 * symbol itself) of the operation implemented by this visitor; use
4435 * Void if a second argument is not needed.
4436 */
4437 public static abstract class DefaultSymbolVisitor<R,S> implements Symbol.Visitor<R,S> {
4438 final public R visit(Symbol s, S arg) { return s.accept(this, arg); }
4439 public R visitClassSymbol(ClassSymbol s, S arg) { return visitSymbol(s, arg); }
4440 public R visitMethodSymbol(MethodSymbol s, S arg) { return visitSymbol(s, arg); }
4441 public R visitOperatorSymbol(OperatorSymbol s, S arg) { return visitSymbol(s, arg); }
4442 public R visitPackageSymbol(PackageSymbol s, S arg) { return visitSymbol(s, arg); }
4443 public R visitTypeSymbol(TypeSymbol s, S arg) { return visitSymbol(s, arg); }
4444 public R visitVarSymbol(VarSymbol s, S arg) { return visitSymbol(s, arg); }
4445 }
4447 /**
4448 * A <em>simple</em> visitor for types. This visitor is simple as
4449 * captured wildcards, for-all types (generic methods), and
4450 * undetermined type variables (part of inference) are hidden.
4451 * Captured wildcards are hidden by treating them as type
4452 * variables and the rest are hidden by visiting their qtypes.
4453 *
4454 * @param <R> the return type of the operation implemented by this
4455 * visitor; use Void if no return type is needed.
4456 * @param <S> the type of the second argument (the first being the
4457 * type itself) of the operation implemented by this visitor; use
4458 * Void if a second argument is not needed.
4459 */
4460 public static abstract class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> {
4461 @Override
4462 public R visitCapturedType(CapturedType t, S s) {
4463 return visitTypeVar(t, s);
4464 }
4465 @Override
4466 public R visitForAll(ForAll t, S s) {
4467 return visit(t.qtype, s);
4468 }
4469 @Override
4470 public R visitUndetVar(UndetVar t, S s) {
4471 return visit(t.qtype, s);
4472 }
4473 }
4475 /**
4476 * A plain relation on types. That is a 2-ary function on the
4477 * form Type × Type → Boolean.
4478 * <!-- In plain text: Type x Type -> Boolean -->
4479 */
4480 public static abstract class TypeRelation extends SimpleVisitor<Boolean,Type> {}
4482 /**
4483 * A convenience visitor for implementing operations that only
4484 * require one argument (the type itself), that is, unary
4485 * operations.
4486 *
4487 * @param <R> the return type of the operation implemented by this
4488 * visitor; use Void if no return type is needed.
4489 */
4490 public static abstract class UnaryVisitor<R> extends SimpleVisitor<R,Void> {
4491 final public R visit(Type t) { return t.accept(this, null); }
4492 }
4494 /**
4495 * A visitor for implementing a mapping from types to types. The
4496 * default behavior of this class is to implement the identity
4497 * mapping (mapping a type to itself). This can be overridden in
4498 * subclasses.
4499 *
4500 * @param <S> the type of the second argument (the first being the
4501 * type itself) of this mapping; use Void if a second argument is
4502 * not needed.
4503 */
4504 public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> {
4505 final public Type visit(Type t) { return t.accept(this, null); }
4506 public Type visitType(Type t, S s) { return t; }
4507 }
4508 // </editor-fold>
4511 // <editor-fold defaultstate="collapsed" desc="Annotation support">
4513 public RetentionPolicy getRetention(Attribute.Compound a) {
4514 return getRetention(a.type.tsym);
4515 }
4517 public RetentionPolicy getRetention(Symbol sym) {
4518 RetentionPolicy vis = RetentionPolicy.CLASS; // the default
4519 Attribute.Compound c = sym.attribute(syms.retentionType.tsym);
4520 if (c != null) {
4521 Attribute value = c.member(names.value);
4522 if (value != null && value instanceof Attribute.Enum) {
4523 Name levelName = ((Attribute.Enum)value).value.name;
4524 if (levelName == names.SOURCE) vis = RetentionPolicy.SOURCE;
4525 else if (levelName == names.CLASS) vis = RetentionPolicy.CLASS;
4526 else if (levelName == names.RUNTIME) vis = RetentionPolicy.RUNTIME;
4527 else ;// /* fail soft */ throw new AssertionError(levelName);
4528 }
4529 }
4530 return vis;
4531 }
4532 // </editor-fold>
4534 // <editor-fold defaultstate="collapsed" desc="Signature Generation">
4536 public static abstract class SignatureGenerator {
4538 private final Types types;
4540 protected abstract void append(char ch);
4541 protected abstract void append(byte[] ba);
4542 protected abstract void append(Name name);
4543 protected void classReference(ClassSymbol c) { /* by default: no-op */ }
4545 protected SignatureGenerator(Types types) {
4546 this.types = types;
4547 }
4549 /**
4550 * Assemble signature of given type in string buffer.
4551 */
4552 public void assembleSig(Type type) {
4553 type = type.unannotatedType();
4554 switch (type.getTag()) {
4555 case BYTE:
4556 append('B');
4557 break;
4558 case SHORT:
4559 append('S');
4560 break;
4561 case CHAR:
4562 append('C');
4563 break;
4564 case INT:
4565 append('I');
4566 break;
4567 case LONG:
4568 append('J');
4569 break;
4570 case FLOAT:
4571 append('F');
4572 break;
4573 case DOUBLE:
4574 append('D');
4575 break;
4576 case BOOLEAN:
4577 append('Z');
4578 break;
4579 case VOID:
4580 append('V');
4581 break;
4582 case CLASS:
4583 append('L');
4584 assembleClassSig(type);
4585 append(';');
4586 break;
4587 case ARRAY:
4588 ArrayType at = (ArrayType) type;
4589 append('[');
4590 assembleSig(at.elemtype);
4591 break;
4592 case METHOD:
4593 MethodType mt = (MethodType) type;
4594 append('(');
4595 assembleSig(mt.argtypes);
4596 append(')');
4597 assembleSig(mt.restype);
4598 if (hasTypeVar(mt.thrown)) {
4599 for (List<Type> l = mt.thrown; l.nonEmpty(); l = l.tail) {
4600 append('^');
4601 assembleSig(l.head);
4602 }
4603 }
4604 break;
4605 case WILDCARD: {
4606 Type.WildcardType ta = (Type.WildcardType) type;
4607 switch (ta.kind) {
4608 case SUPER:
4609 append('-');
4610 assembleSig(ta.type);
4611 break;
4612 case EXTENDS:
4613 append('+');
4614 assembleSig(ta.type);
4615 break;
4616 case UNBOUND:
4617 append('*');
4618 break;
4619 default:
4620 throw new AssertionError(ta.kind);
4621 }
4622 break;
4623 }
4624 case TYPEVAR:
4625 append('T');
4626 append(type.tsym.name);
4627 append(';');
4628 break;
4629 case FORALL:
4630 Type.ForAll ft = (Type.ForAll) type;
4631 assembleParamsSig(ft.tvars);
4632 assembleSig(ft.qtype);
4633 break;
4634 default:
4635 throw new AssertionError("typeSig " + type.getTag());
4636 }
4637 }
4639 public boolean hasTypeVar(List<Type> l) {
4640 while (l.nonEmpty()) {
4641 if (l.head.hasTag(TypeTag.TYPEVAR)) {
4642 return true;
4643 }
4644 l = l.tail;
4645 }
4646 return false;
4647 }
4649 public void assembleClassSig(Type type) {
4650 type = type.unannotatedType();
4651 ClassType ct = (ClassType) type;
4652 ClassSymbol c = (ClassSymbol) ct.tsym;
4653 classReference(c);
4654 Type outer = ct.getEnclosingType();
4655 if (outer.allparams().nonEmpty()) {
4656 boolean rawOuter =
4657 c.owner.kind == Kinds.MTH || // either a local class
4658 c.name == types.names.empty; // or anonymous
4659 assembleClassSig(rawOuter
4660 ? types.erasure(outer)
4661 : outer);
4662 append('.');
4663 Assert.check(c.flatname.startsWith(c.owner.enclClass().flatname));
4664 append(rawOuter
4665 ? c.flatname.subName(c.owner.enclClass().flatname.getByteLength() + 1, c.flatname.getByteLength())
4666 : c.name);
4667 } else {
4668 append(externalize(c.flatname));
4669 }
4670 if (ct.getTypeArguments().nonEmpty()) {
4671 append('<');
4672 assembleSig(ct.getTypeArguments());
4673 append('>');
4674 }
4675 }
4677 public void assembleParamsSig(List<Type> typarams) {
4678 append('<');
4679 for (List<Type> ts = typarams; ts.nonEmpty(); ts = ts.tail) {
4680 Type.TypeVar tvar = (Type.TypeVar) ts.head;
4681 append(tvar.tsym.name);
4682 List<Type> bounds = types.getBounds(tvar);
4683 if ((bounds.head.tsym.flags() & INTERFACE) != 0) {
4684 append(':');
4685 }
4686 for (List<Type> l = bounds; l.nonEmpty(); l = l.tail) {
4687 append(':');
4688 assembleSig(l.head);
4689 }
4690 }
4691 append('>');
4692 }
4694 private void assembleSig(List<Type> types) {
4695 for (List<Type> ts = types; ts.nonEmpty(); ts = ts.tail) {
4696 assembleSig(ts.head);
4697 }
4698 }
4699 }
4700 // </editor-fold>
4701 }
