| 1 | /* |
| 2 | * Copyright 2003-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.tools.javac.code; |
| 27 | |
| 28 | import java.util.*; |
| 29 | |
| 30 | import com.sun.tools.javac.util.*; |
| 31 | import com.sun.tools.javac.util.List; |
| 32 | |
| 33 | import com.sun.tools.javac.jvm.ClassReader; |
| 34 | import com.sun.tools.javac.comp.Infer; |
| 35 | import com.sun.tools.javac.comp.Check; |
| 36 | |
| 37 | import static com.sun.tools.javac.code.Type.*; |
| 38 | import static com.sun.tools.javac.code.TypeTags.*; |
| 39 | import static com.sun.tools.javac.code.Symbol.*; |
| 40 | import static com.sun.tools.javac.code.Flags.*; |
| 41 | import static com.sun.tools.javac.code.BoundKind.*; |
| 42 | import static com.sun.tools.javac.util.ListBuffer.lb; |
| 43 | |
| 44 | /** |
| 45 | * Utility class containing various operations on types. |
| 46 | * |
| 47 | * <p>Unless other names are more illustrative, the following naming |
| 48 | * conventions should be observed in this file: |
| 49 | * |
| 50 | * <dl> |
| 51 | * <dt>t</dt> |
| 52 | * <dd>If the first argument to an operation is a type, it should be named t.</dd> |
| 53 | * <dt>s</dt> |
| 54 | * <dd>Similarly, if the second argument to an operation is a type, it should be named s.</dd> |
| 55 | * <dt>ts</dt> |
| 56 | * <dd>If an operations takes a list of types, the first should be named ts.</dd> |
| 57 | * <dt>ss</dt> |
| 58 | * <dd>A second list of types should be named ss.</dd> |
| 59 | * </dl> |
| 60 | * |
| 61 | * <p><b>This is NOT part of any API supported by Sun Microsystems. |
| 62 | * If you write code that depends on this, you do so at your own risk. |
| 63 | * This code and its internal interfaces are subject to change or |
| 64 | * deletion without notice.</b> |
| 65 | */ |
| 66 | public class Types { |
| 67 | protected static final Context.Key<Types> typesKey = |
| 68 | new Context.Key<Types>(); |
| 69 | |
| 70 | final Symtab syms; |
| 71 | final Name.Table names; |
| 72 | final boolean allowBoxing; |
| 73 | final ClassReader reader; |
| 74 | final Source source; |
| 75 | final Check chk; |
| 76 | List<Warner> warnStack = List.nil(); |
| 77 | final Name capturedName; |
| 78 | |
| 79 | // <editor-fold defaultstate="collapsed" desc="Instantiating"> |
| 80 | public static Types instance(Context context) { |
| 81 | Types instance = context.get(typesKey); |
| 82 | if (instance == null) |
| 83 | instance = new Types(context); |
| 84 | return instance; |
| 85 | } |
| 86 | |
| 87 | protected Types(Context context) { |
| 88 | context.put(typesKey, this); |
| 89 | syms = Symtab.instance(context); |
| 90 | names = Name.Table.instance(context); |
| 91 | allowBoxing = Source.instance(context).allowBoxing(); |
| 92 | reader = ClassReader.instance(context); |
| 93 | source = Source.instance(context); |
| 94 | chk = Check.instance(context); |
| 95 | capturedName = names.fromString("<captured wildcard>"); |
| 96 | } |
| 97 | // </editor-fold> |
| 98 | |
| 99 | // <editor-fold defaultstate="collapsed" desc="upperBound"> |
| 100 | /** |
| 101 | * The "rvalue conversion".<br> |
| 102 | * The upper bound of most types is the type |
| 103 | * itself. Wildcards, on the other hand have upper |
| 104 | * and lower bounds. |
| 105 | * @param t a type |
| 106 | * @return the upper bound of the given type |
| 107 | */ |
| 108 | public Type upperBound(Type t) { |
| 109 | return upperBound.visit(t); |
| 110 | } |
| 111 | // where |
| 112 | private final MapVisitor<Void> upperBound = new MapVisitor<Void>() { |
| 113 | |
| 114 | @Override |
| 115 | public Type visitWildcardType(WildcardType t, Void ignored) { |
| 116 | if (t.isSuperBound()) |
| 117 | return t.bound == null ? syms.objectType : t.bound.bound; |
| 118 | else |
| 119 | return visit(t.type); |
| 120 | } |
| 121 | |
| 122 | @Override |
| 123 | public Type visitCapturedType(CapturedType t, Void ignored) { |
| 124 | return visit(t.bound); |
| 125 | } |
| 126 | }; |
| 127 | // </editor-fold> |
| 128 | |
| 129 | // <editor-fold defaultstate="collapsed" desc="lowerBound"> |
| 130 | /** |
| 131 | * The "lvalue conversion".<br> |
| 132 | * The lower bound of most types is the type |
| 133 | * itself. Wildcards, on the other hand have upper |
| 134 | * and lower bounds. |
| 135 | * @param t a type |
| 136 | * @return the lower bound of the given type |
| 137 | */ |
| 138 | public Type lowerBound(Type t) { |
| 139 | return lowerBound.visit(t); |
| 140 | } |
| 141 | // where |
| 142 | private final MapVisitor<Void> lowerBound = new MapVisitor<Void>() { |
| 143 | |
| 144 | @Override |
| 145 | public Type visitWildcardType(WildcardType t, Void ignored) { |
| 146 | return t.isExtendsBound() ? syms.botType : visit(t.type); |
| 147 | } |
| 148 | |
| 149 | @Override |
| 150 | public Type visitCapturedType(CapturedType t, Void ignored) { |
| 151 | return visit(t.getLowerBound()); |
| 152 | } |
| 153 | }; |
| 154 | // </editor-fold> |
| 155 | |
| 156 | // <editor-fold defaultstate="collapsed" desc="isUnbounded"> |
| 157 | /** |
| 158 | * Checks that all the arguments to a class are unbounded |
| 159 | * wildcards or something else that doesn't make any restrictions |
| 160 | * on the arguments. If a class isUnbounded, a raw super- or |
| 161 | * subclass can be cast to it without a warning. |
| 162 | * @param t a type |
| 163 | * @return true iff the given type is unbounded or raw |
| 164 | */ |
| 165 | public boolean isUnbounded(Type t) { |
| 166 | return isUnbounded.visit(t); |
| 167 | } |
| 168 | // where |
| 169 | private final UnaryVisitor<Boolean> isUnbounded = new UnaryVisitor<Boolean>() { |
| 170 | |
| 171 | public Boolean visitType(Type t, Void ignored) { |
| 172 | return true; |
| 173 | } |
| 174 | |
| 175 | @Override |
| 176 | public Boolean visitClassType(ClassType t, Void ignored) { |
| 177 | List<Type> parms = t.tsym.type.allparams(); |
| 178 | List<Type> args = t.allparams(); |
| 179 | while (parms.nonEmpty()) { |
| 180 | WildcardType unb = new WildcardType(syms.objectType, |
| 181 | BoundKind.UNBOUND, |
| 182 | syms.boundClass, |
| 183 | (TypeVar)parms.head); |
| 184 | if (!containsType(args.head, unb)) |
| 185 | return false; |
| 186 | parms = parms.tail; |
| 187 | args = args.tail; |
| 188 | } |
| 189 | return true; |
| 190 | } |
| 191 | }; |
| 192 | // </editor-fold> |
| 193 | |
| 194 | // <editor-fold defaultstate="collapsed" desc="asSub"> |
| 195 | /** |
| 196 | * Return the least specific subtype of t that starts with symbol |
| 197 | * sym. If none exists, return null. The least specific subtype |
| 198 | * is determined as follows: |
| 199 | * |
| 200 | * <p>If there is exactly one parameterized instance of sym that is a |
| 201 | * subtype of t, that parameterized instance is returned.<br> |
| 202 | * Otherwise, if the plain type or raw type `sym' is a subtype of |
| 203 | * type t, the type `sym' itself is returned. Otherwise, null is |
| 204 | * returned. |
| 205 | */ |
| 206 | public Type asSub(Type t, Symbol sym) { |
| 207 | return asSub.visit(t, sym); |
| 208 | } |
| 209 | // where |
| 210 | private final SimpleVisitor<Type,Symbol> asSub = new SimpleVisitor<Type,Symbol>() { |
| 211 | |
| 212 | public Type visitType(Type t, Symbol sym) { |
| 213 | return null; |
| 214 | } |
| 215 | |
| 216 | @Override |
| 217 | public Type visitClassType(ClassType t, Symbol sym) { |
| 218 | if (t.tsym == sym) |
| 219 | return t; |
| 220 | Type base = asSuper(sym.type, t.tsym); |
| 221 | if (base == null) |
| 222 | return null; |
| 223 | ListBuffer<Type> from = new ListBuffer<Type>(); |
| 224 | ListBuffer<Type> to = new ListBuffer<Type>(); |
| 225 | try { |
| 226 | adapt(base, t, from, to); |
| 227 | } catch (AdaptFailure ex) { |
| 228 | return null; |
| 229 | } |
| 230 | Type res = subst(sym.type, from.toList(), to.toList()); |
| 231 | if (!isSubtype(res, t)) |
| 232 | return null; |
| 233 | ListBuffer<Type> openVars = new ListBuffer<Type>(); |
| 234 | for (List<Type> l = sym.type.allparams(); |
| 235 | l.nonEmpty(); l = l.tail) |
| 236 | if (res.contains(l.head) && !t.contains(l.head)) |
| 237 | openVars.append(l.head); |
| 238 | if (openVars.nonEmpty()) { |
| 239 | if (t.isRaw()) { |
| 240 | // The subtype of a raw type is raw |
| 241 | res = erasure(res); |
| 242 | } else { |
| 243 | // Unbound type arguments default to ? |
| 244 | List<Type> opens = openVars.toList(); |
| 245 | ListBuffer<Type> qs = new ListBuffer<Type>(); |
| 246 | for (List<Type> iter = opens; iter.nonEmpty(); iter = iter.tail) { |
| 247 | qs.append(new WildcardType(syms.objectType, BoundKind.UNBOUND, syms.boundClass, (TypeVar) iter.head)); |
| 248 | } |
| 249 | res = subst(res, opens, qs.toList()); |
| 250 | } |
| 251 | } |
| 252 | return res; |
| 253 | } |
| 254 | |
| 255 | @Override |
| 256 | public Type visitErrorType(ErrorType t, Symbol sym) { |
| 257 | return t; |
| 258 | } |
| 259 | }; |
| 260 | // </editor-fold> |
| 261 | |
| 262 | // <editor-fold defaultstate="collapsed" desc="isConvertible"> |
| 263 | /** |
| 264 | * Is t a subtype of or convertiable via boxing/unboxing |
| 265 | * convertions to s? |
| 266 | */ |
| 267 | public boolean isConvertible(Type t, Type s, Warner warn) { |
| 268 | boolean tPrimitive = t.isPrimitive(); |
| 269 | boolean sPrimitive = s.isPrimitive(); |
| 270 | if (tPrimitive == sPrimitive) |
| 271 | return isSubtypeUnchecked(t, s, warn); |
| 272 | if (!allowBoxing) return false; |
| 273 | return tPrimitive |
| 274 | ? isSubtype(boxedClass(t).type, s) |
| 275 | : isSubtype(unboxedType(t), s); |
| 276 | } |
| 277 | |
| 278 | /** |
| 279 | * Is t a subtype of or convertiable via boxing/unboxing |
| 280 | * convertions to s? |
| 281 | */ |
| 282 | public boolean isConvertible(Type t, Type s) { |
| 283 | return isConvertible(t, s, Warner.noWarnings); |
| 284 | } |
| 285 | // </editor-fold> |
| 286 | |
| 287 | // <editor-fold defaultstate="collapsed" desc="isSubtype"> |
| 288 | /** |
| 289 | * Is t an unchecked subtype of s? |
| 290 | */ |
| 291 | public boolean isSubtypeUnchecked(Type t, Type s) { |
| 292 | return isSubtypeUnchecked(t, s, Warner.noWarnings); |
| 293 | } |
| 294 | /** |
| 295 | * Is t an unchecked subtype of s? |
| 296 | */ |
| 297 | public boolean isSubtypeUnchecked(Type t, Type s, Warner warn) { |
| 298 | if (t.tag == ARRAY && s.tag == ARRAY) { |
| 299 | return (((ArrayType)t).elemtype.tag <= lastBaseTag) |
| 300 | ? isSameType(elemtype(t), elemtype(s)) |
| 301 | : isSubtypeUnchecked(elemtype(t), elemtype(s), warn); |
| 302 | } else if (isSubtype(t, s)) { |
| 303 | return true; |
| 304 | } else if (!s.isRaw()) { |
| 305 | Type t2 = asSuper(t, s.tsym); |
| 306 | if (t2 != null && t2.isRaw()) { |
| 307 | if (isReifiable(s)) |
| 308 | warn.silentUnchecked(); |
| 309 | else |
| 310 | warn.warnUnchecked(); |
| 311 | return true; |
| 312 | } |
| 313 | } |
| 314 | return false; |
| 315 | } |
| 316 | |
| 317 | /** |
| 318 | * Is t a subtype of s?<br> |
| 319 | * (not defined for Method and ForAll types) |
| 320 | */ |
| 321 | final public boolean isSubtype(Type t, Type s) { |
| 322 | return isSubtype(t, s, true); |
| 323 | } |
| 324 | final public boolean isSubtypeNoCapture(Type t, Type s) { |
| 325 | return isSubtype(t, s, false); |
| 326 | } |
| 327 | public boolean isSubtype(Type t, Type s, boolean capture) { |
| 328 | if (t == s) |
| 329 | return true; |
| 330 | |
| 331 | if (s.tag >= firstPartialTag) |
| 332 | return isSuperType(s, t); |
| 333 | |
| 334 | Type lower = lowerBound(s); |
| 335 | if (s != lower) |
| 336 | return isSubtype(capture ? capture(t) : t, lower, false); |
| 337 | |
| 338 | return isSubtype.visit(capture ? capture(t) : t, s); |
| 339 | } |
| 340 | // where |
| 341 | private TypeRelation isSubtype = new TypeRelation() |
| 342 | { |
| 343 | public Boolean visitType(Type t, Type s) { |
| 344 | switch (t.tag) { |
| 345 | case BYTE: case CHAR: |
| 346 | return (t.tag == s.tag || |
| 347 | t.tag + 2 <= s.tag && s.tag <= DOUBLE); |
| 348 | case SHORT: case INT: case LONG: case FLOAT: case DOUBLE: |
| 349 | return t.tag <= s.tag && s.tag <= DOUBLE; |
| 350 | case BOOLEAN: case VOID: |
| 351 | return t.tag == s.tag; |
| 352 | case TYPEVAR: |
| 353 | return isSubtypeNoCapture(t.getUpperBound(), s); |
| 354 | case BOT: |
| 355 | return |
| 356 | s.tag == BOT || s.tag == CLASS || |
| 357 | s.tag == ARRAY || s.tag == TYPEVAR; |
| 358 | case NONE: |
| 359 | return false; |
| 360 | default: |
| 361 | throw new AssertionError("isSubtype " + t.tag); |
| 362 | } |
| 363 | } |
| 364 | |
| 365 | private Set<TypePair> cache = new HashSet<TypePair>(); |
| 366 | |
| 367 | private boolean containsTypeRecursive(Type t, Type s) { |
| 368 | TypePair pair = new TypePair(t, s); |
| 369 | if (cache.add(pair)) { |
| 370 | try { |
| 371 | return containsType(t.getTypeArguments(), |
| 372 | s.getTypeArguments()); |
| 373 | } finally { |
| 374 | cache.remove(pair); |
| 375 | } |
| 376 | } else { |
| 377 | return containsType(t.getTypeArguments(), |
| 378 | rewriteSupers(s).getTypeArguments()); |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | private Type rewriteSupers(Type t) { |
| 383 | if (!t.isParameterized()) |
| 384 | return t; |
| 385 | ListBuffer<Type> from = lb(); |
| 386 | ListBuffer<Type> to = lb(); |
| 387 | adaptSelf(t, from, to); |
| 388 | if (from.isEmpty()) |
| 389 | return t; |
| 390 | ListBuffer<Type> rewrite = lb(); |
| 391 | boolean changed = false; |
| 392 | for (Type orig : to.toList()) { |
| 393 | Type s = rewriteSupers(orig); |
| 394 | if (s.isSuperBound() && !s.isExtendsBound()) { |
| 395 | s = new WildcardType(syms.objectType, |
| 396 | BoundKind.UNBOUND, |
| 397 | syms.boundClass); |
| 398 | changed = true; |
| 399 | } else if (s != orig) { |
| 400 | s = new WildcardType(upperBound(s), |
| 401 | BoundKind.EXTENDS, |
| 402 | syms.boundClass); |
| 403 | changed = true; |
| 404 | } |
| 405 | rewrite.append(s); |
| 406 | } |
| 407 | if (changed) |
| 408 | return subst(t.tsym.type, from.toList(), rewrite.toList()); |
| 409 | else |
| 410 | return t; |
| 411 | } |
| 412 | |
| 413 | @Override |
| 414 | public Boolean visitClassType(ClassType t, Type s) { |
| 415 | Type sup = asSuper(t, s.tsym); |
| 416 | return sup != null |
| 417 | && sup.tsym == s.tsym |
| 418 | // You're not allowed to write |
| 419 | // Vector<Object> vec = new Vector<String>(); |
| 420 | // But with wildcards you can write |
| 421 | // Vector<? extends Object> vec = new Vector<String>(); |
| 422 | // which means that subtype checking must be done |
| 423 | // here instead of same-type checking (via containsType). |
| 424 | && (!s.isParameterized() || containsTypeRecursive(s, sup)) |
| 425 | && isSubtypeNoCapture(sup.getEnclosingType(), |
| 426 | s.getEnclosingType()); |
| 427 | } |
| 428 | |
| 429 | @Override |
| 430 | public Boolean visitArrayType(ArrayType t, Type s) { |
| 431 | if (s.tag == ARRAY) { |
| 432 | if (t.elemtype.tag <= lastBaseTag) |
| 433 | return isSameType(t.elemtype, elemtype(s)); |
| 434 | else |
| 435 | return isSubtypeNoCapture(t.elemtype, elemtype(s)); |
| 436 | } |
| 437 | |
| 438 | if (s.tag == CLASS) { |
| 439 | Name sname = s.tsym.getQualifiedName(); |
| 440 | return sname == names.java_lang_Object |
| 441 | || sname == names.java_lang_Cloneable |
| 442 | || sname == names.java_io_Serializable; |
| 443 | } |
| 444 | |
| 445 | return false; |
| 446 | } |
| 447 | |
| 448 | @Override |
| 449 | public Boolean visitUndetVar(UndetVar t, Type s) { |
| 450 | //todo: test against origin needed? or replace with substitution? |
| 451 | if (t == s || t.qtype == s || s.tag == ERROR || s.tag == UNKNOWN) |
| 452 | return true; |
| 453 | |
| 454 | if (t.inst != null) |
| 455 | return isSubtypeNoCapture(t.inst, s); // TODO: ", warn"? |
| 456 | |
| 457 | t.hibounds = t.hibounds.prepend(s); |
| 458 | return true; |
| 459 | } |
| 460 | |
| 461 | @Override |
| 462 | public Boolean visitErrorType(ErrorType t, Type s) { |
| 463 | return true; |
| 464 | } |
| 465 | }; |
| 466 | |
| 467 | /** |
| 468 | * Is t a subtype of every type in given list `ts'?<br> |
| 469 | * (not defined for Method and ForAll types)<br> |
| 470 | * Allows unchecked conversions. |
| 471 | */ |
| 472 | public boolean isSubtypeUnchecked(Type t, List<Type> ts, Warner warn) { |
| 473 | for (List<Type> l = ts; l.nonEmpty(); l = l.tail) |
| 474 | if (!isSubtypeUnchecked(t, l.head, warn)) |
| 475 | return false; |
| 476 | return true; |
| 477 | } |
| 478 | |
| 479 | /** |
| 480 | * Are corresponding elements of ts subtypes of ss? If lists are |
| 481 | * of different length, return false. |
| 482 | */ |
| 483 | public boolean isSubtypes(List<Type> ts, List<Type> ss) { |
| 484 | while (ts.tail != null && ss.tail != null |
| 485 | /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && |
| 486 | isSubtype(ts.head, ss.head)) { |
| 487 | ts = ts.tail; |
| 488 | ss = ss.tail; |
| 489 | } |
| 490 | return ts.tail == null && ss.tail == null; |
| 491 | /*inlined: ts.isEmpty() && ss.isEmpty();*/ |
| 492 | } |
| 493 | |
| 494 | /** |
| 495 | * Are corresponding elements of ts subtypes of ss, allowing |
| 496 | * unchecked conversions? If lists are of different length, |
| 497 | * return false. |
| 498 | **/ |
| 499 | public boolean isSubtypesUnchecked(List<Type> ts, List<Type> ss, Warner warn) { |
| 500 | while (ts.tail != null && ss.tail != null |
| 501 | /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && |
| 502 | isSubtypeUnchecked(ts.head, ss.head, warn)) { |
| 503 | ts = ts.tail; |
| 504 | ss = ss.tail; |
| 505 | } |
| 506 | return ts.tail == null && ss.tail == null; |
| 507 | /*inlined: ts.isEmpty() && ss.isEmpty();*/ |
| 508 | } |
| 509 | // </editor-fold> |
| 510 | |
| 511 | // <editor-fold defaultstate="collapsed" desc="isSuperType"> |
| 512 | /** |
| 513 | * Is t a supertype of s? |
| 514 | */ |
| 515 | public boolean isSuperType(Type t, Type s) { |
| 516 | switch (t.tag) { |
| 517 | case ERROR: |
| 518 | return true; |
| 519 | case UNDETVAR: { |
| 520 | UndetVar undet = (UndetVar)t; |
| 521 | if (t == s || |
| 522 | undet.qtype == s || |
| 523 | s.tag == ERROR || |
| 524 | s.tag == BOT) return true; |
| 525 | if (undet.inst != null) |
| 526 | return isSubtype(s, undet.inst); |
| 527 | undet.lobounds = undet.lobounds.prepend(s); |
| 528 | return true; |
| 529 | } |
| 530 | default: |
| 531 | return isSubtype(s, t); |
| 532 | } |
| 533 | } |
| 534 | // </editor-fold> |
| 535 | |
| 536 | // <editor-fold defaultstate="collapsed" desc="isSameType"> |
| 537 | /** |
| 538 | * Are corresponding elements of the lists the same type? If |
| 539 | * lists are of different length, return false. |
| 540 | */ |
| 541 | public boolean isSameTypes(List<Type> ts, List<Type> ss) { |
| 542 | while (ts.tail != null && ss.tail != null |
| 543 | /*inlined: ts.nonEmpty() && ss.nonEmpty()*/ && |
| 544 | isSameType(ts.head, ss.head)) { |
| 545 | ts = ts.tail; |
| 546 | ss = ss.tail; |
| 547 | } |
| 548 | return ts.tail == null && ss.tail == null; |
| 549 | /*inlined: ts.isEmpty() && ss.isEmpty();*/ |
| 550 | } |
| 551 | |
| 552 | /** |
| 553 | * Is t the same type as s? |
| 554 | */ |
| 555 | public boolean isSameType(Type t, Type s) { |
| 556 | return isSameType.visit(t, s); |
| 557 | } |
| 558 | // where |
| 559 | private TypeRelation isSameType = new TypeRelation() { |
| 560 | |
| 561 | public Boolean visitType(Type t, Type s) { |
| 562 | if (t == s) |
| 563 | return true; |
| 564 | |
| 565 | if (s.tag >= firstPartialTag) |
| 566 | return visit(s, t); |
| 567 | |
| 568 | switch (t.tag) { |
| 569 | case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: |
| 570 | case DOUBLE: case BOOLEAN: case VOID: case BOT: case NONE: |
| 571 | return t.tag == s.tag; |
| 572 | case TYPEVAR: |
| 573 | return s.isSuperBound() |
| 574 | && !s.isExtendsBound() |
| 575 | && visit(t, upperBound(s)); |
| 576 | default: |
| 577 | throw new AssertionError("isSameType " + t.tag); |
| 578 | } |
| 579 | } |
| 580 | |
| 581 | @Override |
| 582 | public Boolean visitWildcardType(WildcardType t, Type s) { |
| 583 | if (s.tag >= firstPartialTag) |
| 584 | return visit(s, t); |
| 585 | else |
| 586 | return false; |
| 587 | } |
| 588 | |
| 589 | @Override |
| 590 | public Boolean visitClassType(ClassType t, Type s) { |
| 591 | if (t == s) |
| 592 | return true; |
| 593 | |
| 594 | if (s.tag >= firstPartialTag) |
| 595 | return visit(s, t); |
| 596 | |
| 597 | if (s.isSuperBound() && !s.isExtendsBound()) |
| 598 | return visit(t, upperBound(s)) && visit(t, lowerBound(s)); |
| 599 | |
| 600 | if (t.isCompound() && s.isCompound()) { |
| 601 | if (!visit(supertype(t), supertype(s))) |
| 602 | return false; |
| 603 | |
| 604 | HashSet<SingletonType> set = new HashSet<SingletonType>(); |
| 605 | for (Type x : interfaces(t)) |
| 606 | set.add(new SingletonType(x)); |
| 607 | for (Type x : interfaces(s)) { |
| 608 | if (!set.remove(new SingletonType(x))) |
| 609 | return false; |
| 610 | } |
| 611 | return (set.size() == 0); |
| 612 | } |
| 613 | return t.tsym == s.tsym |
| 614 | && visit(t.getEnclosingType(), s.getEnclosingType()) |
| 615 | && containsTypeEquivalent(t.getTypeArguments(), s.getTypeArguments()); |
| 616 | } |
| 617 | |
| 618 | @Override |
| 619 | public Boolean visitArrayType(ArrayType t, Type s) { |
| 620 | if (t == s) |
| 621 | return true; |
| 622 | |
| 623 | if (s.tag >= firstPartialTag) |
| 624 | return visit(s, t); |
| 625 | |
| 626 | return s.tag == ARRAY |
| 627 | && containsTypeEquivalent(t.elemtype, elemtype(s)); |
| 628 | } |
| 629 | |
| 630 | @Override |
| 631 | public Boolean visitMethodType(MethodType t, Type s) { |
| 632 | // isSameType for methods does not take thrown |
| 633 | // exceptions into account! |
| 634 | return hasSameArgs(t, s) && visit(t.getReturnType(), s.getReturnType()); |
| 635 | } |
| 636 | |
| 637 | @Override |
| 638 | public Boolean visitPackageType(PackageType t, Type s) { |
| 639 | return t == s; |
| 640 | } |
| 641 | |
| 642 | @Override |
| 643 | public Boolean visitForAll(ForAll t, Type s) { |
| 644 | if (s.tag != FORALL) |
| 645 | return false; |
| 646 | |
| 647 | ForAll forAll = (ForAll)s; |
| 648 | return hasSameBounds(t, forAll) |
| 649 | && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); |
| 650 | } |
| 651 | |
| 652 | @Override |
| 653 | public Boolean visitUndetVar(UndetVar t, Type s) { |
| 654 | if (s.tag == WILDCARD) |
| 655 | // FIXME, this might be leftovers from before capture conversion |
| 656 | return false; |
| 657 | |
| 658 | if (t == s || t.qtype == s || s.tag == ERROR || s.tag == UNKNOWN) |
| 659 | return true; |
| 660 | |
| 661 | if (t.inst != null) |
| 662 | return visit(t.inst, s); |
| 663 | |
| 664 | t.inst = fromUnknownFun.apply(s); |
| 665 | for (List<Type> l = t.lobounds; l.nonEmpty(); l = l.tail) { |
| 666 | if (!isSubtype(l.head, t.inst)) |
| 667 | return false; |
| 668 | } |
| 669 | for (List<Type> l = t.hibounds; l.nonEmpty(); l = l.tail) { |
| 670 | if (!isSubtype(t.inst, l.head)) |
| 671 | return false; |
| 672 | } |
| 673 | return true; |
| 674 | } |
| 675 | |
| 676 | @Override |
| 677 | public Boolean visitErrorType(ErrorType t, Type s) { |
| 678 | return true; |
| 679 | } |
| 680 | }; |
| 681 | // </editor-fold> |
| 682 | |
| 683 | // <editor-fold defaultstate="collapsed" desc="fromUnknownFun"> |
| 684 | /** |
| 685 | * A mapping that turns all unknown types in this type to fresh |
| 686 | * unknown variables. |
| 687 | */ |
| 688 | public Mapping fromUnknownFun = new Mapping("fromUnknownFun") { |
| 689 | public Type apply(Type t) { |
| 690 | if (t.tag == UNKNOWN) return new UndetVar(t); |
| 691 | else return t.map(this); |
| 692 | } |
| 693 | }; |
| 694 | // </editor-fold> |
| 695 | |
| 696 | // <editor-fold defaultstate="collapsed" desc="Contains Type"> |
| 697 | public boolean containedBy(Type t, Type s) { |
| 698 | switch (t.tag) { |
| 699 | case UNDETVAR: |
| 700 | if (s.tag == WILDCARD) { |
| 701 | UndetVar undetvar = (UndetVar)t; |
| 702 | |
| 703 | // Because of wildcard capture, s must be on the left |
| 704 | // hand side of an assignment. Furthermore, t is an |
| 705 | // underconstrained type variable, for example, one |
| 706 | // that is only used in the return type of a method. |
| 707 | // If the type variable is truly underconstrained, it |
| 708 | // cannot have any low bounds: |
| 709 | assert undetvar.lobounds.isEmpty() : undetvar; |
| 710 | |
| 711 | undetvar.inst = glb(upperBound(s), undetvar.inst); |
| 712 | return true; |
| 713 | } else { |
| 714 | return isSameType(t, s); |
| 715 | } |
| 716 | case ERROR: |
| 717 | return true; |
| 718 | default: |
| 719 | return containsType(s, t); |
| 720 | } |
| 721 | } |
| 722 | |
| 723 | boolean containsType(List<Type> ts, List<Type> ss) { |
| 724 | while (ts.nonEmpty() && ss.nonEmpty() |
| 725 | && containsType(ts.head, ss.head)) { |
| 726 | ts = ts.tail; |
| 727 | ss = ss.tail; |
| 728 | } |
| 729 | return ts.isEmpty() && ss.isEmpty(); |
| 730 | } |
| 731 | |
| 732 | /** |
| 733 | * Check if t contains s. |
| 734 | * |
| 735 | * <p>T contains S if: |
| 736 | * |
| 737 | * <p>{@code L(T) <: L(S) && U(S) <: U(T)} |
| 738 | * |
| 739 | * <p>This relation is only used by ClassType.isSubtype(), that |
| 740 | * is, |
| 741 | * |
| 742 | * <p>{@code C<S> <: C<T> if T contains S.} |
| 743 | * |
| 744 | * <p>Because of F-bounds, this relation can lead to infinite |
| 745 | * recursion. Thus we must somehow break that recursion. Notice |
| 746 | * that containsType() is only called from ClassType.isSubtype(). |
| 747 | * Since the arguments have already been checked against their |
| 748 | * bounds, we know: |
| 749 | * |
| 750 | * <p>{@code U(S) <: U(T) if T is "super" bound (U(T) *is* the bound)} |
| 751 | * |
| 752 | * <p>{@code L(T) <: L(S) if T is "extends" bound (L(T) is bottom)} |
| 753 | * |
| 754 | * @param t a type |
| 755 | * @param s a type |
| 756 | */ |
| 757 | public boolean containsType(Type t, Type s) { |
| 758 | return containsType.visit(t, s); |
| 759 | } |
| 760 | // where |
| 761 | private TypeRelation containsType = new TypeRelation() { |
| 762 | |
| 763 | private Type U(Type t) { |
| 764 | while (t.tag == WILDCARD) { |
| 765 | WildcardType w = (WildcardType)t; |
| 766 | if (w.isSuperBound()) |
| 767 | return w.bound == null ? syms.objectType : w.bound.bound; |
| 768 | else |
| 769 | t = w.type; |
| 770 | } |
| 771 | return t; |
| 772 | } |
| 773 | |
| 774 | private Type L(Type t) { |
| 775 | while (t.tag == WILDCARD) { |
| 776 | WildcardType w = (WildcardType)t; |
| 777 | if (w.isExtendsBound()) |
| 778 | return syms.botType; |
| 779 | else |
| 780 | t = w.type; |
| 781 | } |
| 782 | return t; |
| 783 | } |
| 784 | |
| 785 | public Boolean visitType(Type t, Type s) { |
| 786 | if (s.tag >= firstPartialTag) |
| 787 | return containedBy(s, t); |
| 788 | else |
| 789 | return isSameType(t, s); |
| 790 | } |
| 791 | |
| 792 | void debugContainsType(WildcardType t, Type s) { |
| 793 | System.err.println(); |
| 794 | System.err.format(" does %s contain %s?%n", t, s); |
| 795 | System.err.format(" %s U(%s) <: U(%s) %s = %s%n", |
| 796 | upperBound(s), s, t, U(t), |
| 797 | t.isSuperBound() |
| 798 | || isSubtypeNoCapture(upperBound(s), U(t))); |
| 799 | System.err.format(" %s L(%s) <: L(%s) %s = %s%n", |
| 800 | L(t), t, s, lowerBound(s), |
| 801 | t.isExtendsBound() |
| 802 | || isSubtypeNoCapture(L(t), lowerBound(s))); |
| 803 | System.err.println(); |
| 804 | } |
| 805 | |
| 806 | @Override |
| 807 | public Boolean visitWildcardType(WildcardType t, Type s) { |
| 808 | if (s.tag >= firstPartialTag) |
| 809 | return containedBy(s, t); |
| 810 | else { |
| 811 | // debugContainsType(t, s); |
| 812 | return isSameWildcard(t, s) |
| 813 | || isCaptureOf(s, t) |
| 814 | || ((t.isExtendsBound() || isSubtypeNoCapture(L(t), lowerBound(s))) && |
| 815 | (t.isSuperBound() || isSubtypeNoCapture(upperBound(s), U(t)))); |
| 816 | } |
| 817 | } |
| 818 | |
| 819 | @Override |
| 820 | public Boolean visitUndetVar(UndetVar t, Type s) { |
| 821 | if (s.tag != WILDCARD) |
| 822 | return isSameType(t, s); |
| 823 | else |
| 824 | return false; |
| 825 | } |
| 826 | |
| 827 | @Override |
| 828 | public Boolean visitErrorType(ErrorType t, Type s) { |
| 829 | return true; |
| 830 | } |
| 831 | }; |
| 832 | |
| 833 | public boolean isCaptureOf(Type s, WildcardType t) { |
| 834 | if (s.tag != TYPEVAR || !(s instanceof CapturedType)) |
| 835 | return false; |
| 836 | return isSameWildcard(t, ((CapturedType)s).wildcard); |
| 837 | } |
| 838 | |
| 839 | public boolean isSameWildcard(WildcardType t, Type s) { |
| 840 | if (s.tag != WILDCARD) |
| 841 | return false; |
| 842 | WildcardType w = (WildcardType)s; |
| 843 | return w.kind == t.kind && w.type == t.type; |
| 844 | } |
| 845 | |
| 846 | public boolean containsTypeEquivalent(List<Type> ts, List<Type> ss) { |
| 847 | while (ts.nonEmpty() && ss.nonEmpty() |
| 848 | && containsTypeEquivalent(ts.head, ss.head)) { |
| 849 | ts = ts.tail; |
| 850 | ss = ss.tail; |
| 851 | } |
| 852 | return ts.isEmpty() && ss.isEmpty(); |
| 853 | } |
| 854 | // </editor-fold> |
| 855 | |
| 856 | // <editor-fold defaultstate="collapsed" desc="isCastable"> |
| 857 | public boolean isCastable(Type t, Type s) { |
| 858 | return isCastable(t, s, Warner.noWarnings); |
| 859 | } |
| 860 | |
| 861 | /** |
| 862 | * Is t is castable to s?<br> |
| 863 | * s is assumed to be an erased type.<br> |
| 864 | * (not defined for Method and ForAll types). |
| 865 | */ |
| 866 | public boolean isCastable(Type t, Type s, Warner warn) { |
| 867 | if (t == s) |
| 868 | return true; |
| 869 | |
| 870 | if (t.isPrimitive() != s.isPrimitive()) |
| 871 | return allowBoxing && isConvertible(t, s, warn); |
| 872 | |
| 873 | if (warn != warnStack.head) { |
| 874 | try { |
| 875 | warnStack = warnStack.prepend(warn); |
| 876 | return isCastable.visit(t, s); |
| 877 | } finally { |
| 878 | warnStack = warnStack.tail; |
| 879 | } |
| 880 | } else { |
| 881 | return isCastable.visit(t, s); |
| 882 | } |
| 883 | } |
| 884 | // where |
| 885 | private TypeRelation isCastable = new TypeRelation() { |
| 886 | |
| 887 | public Boolean visitType(Type t, Type s) { |
| 888 | if (s.tag == ERROR) |
| 889 | return true; |
| 890 | |
| 891 | switch (t.tag) { |
| 892 | case BYTE: case CHAR: case SHORT: case INT: case LONG: case FLOAT: |
| 893 | case DOUBLE: |
| 894 | return s.tag <= DOUBLE; |
| 895 | case BOOLEAN: |
| 896 | return s.tag == BOOLEAN; |
| 897 | case VOID: |
| 898 | return false; |
| 899 | case BOT: |
| 900 | return isSubtype(t, s); |
| 901 | default: |
| 902 | throw new AssertionError(); |
| 903 | } |
| 904 | } |
| 905 | |
| 906 | @Override |
| 907 | public Boolean visitWildcardType(WildcardType t, Type s) { |
| 908 | return isCastable(upperBound(t), s, warnStack.head); |
| 909 | } |
| 910 | |
| 911 | @Override |
| 912 | public Boolean visitClassType(ClassType t, Type s) { |
| 913 | if (s.tag == ERROR || s.tag == BOT) |
| 914 | return true; |
| 915 | |
| 916 | if (s.tag == TYPEVAR) { |
| 917 | if (isCastable(s.getUpperBound(), t, Warner.noWarnings)) { |
| 918 | warnStack.head.warnUnchecked(); |
| 919 | return true; |
| 920 | } else { |
| 921 | return false; |
| 922 | } |
| 923 | } |
| 924 | |
| 925 | if (t.isCompound()) { |
| 926 | if (!visit(supertype(t), s)) |
| 927 | return false; |
| 928 | for (Type intf : interfaces(t)) { |
| 929 | if (!visit(intf, s)) |
| 930 | return false; |
| 931 | } |
| 932 | return true; |
| 933 | } |
| 934 | |
| 935 | if (s.isCompound()) { |
| 936 | // call recursively to reuse the above code |
| 937 | return visitClassType((ClassType)s, t); |
| 938 | } |
| 939 | |
| 940 | if (s.tag == CLASS || s.tag == ARRAY) { |
| 941 | boolean upcast; |
| 942 | if ((upcast = isSubtype(erasure(t), erasure(s))) |
| 943 | || isSubtype(erasure(s), erasure(t))) { |
| 944 | if (!upcast && s.tag == ARRAY) { |
| 945 | if (!isReifiable(s)) |
| 946 | warnStack.head.warnUnchecked(); |
| 947 | return true; |
| 948 | } else if (s.isRaw()) { |
| 949 | return true; |
| 950 | } else if (t.isRaw()) { |
| 951 | if (!isUnbounded(s)) |
| 952 | warnStack.head.warnUnchecked(); |
| 953 | return true; |
| 954 | } |
| 955 | // Assume |a| <: |b| |
| 956 | final Type a = upcast ? t : s; |
| 957 | final Type b = upcast ? s : t; |
| 958 | final boolean HIGH = true; |
| 959 | final boolean LOW = false; |
| 960 | final boolean DONT_REWRITE_TYPEVARS = false; |
| 961 | Type aHigh = rewriteQuantifiers(a, HIGH, DONT_REWRITE_TYPEVARS); |
| 962 | Type aLow = rewriteQuantifiers(a, LOW, DONT_REWRITE_TYPEVARS); |
| 963 | Type bHigh = rewriteQuantifiers(b, HIGH, DONT_REWRITE_TYPEVARS); |
| 964 | Type bLow = rewriteQuantifiers(b, LOW, DONT_REWRITE_TYPEVARS); |
| 965 | Type lowSub = asSub(bLow, aLow.tsym); |
| 966 | Type highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); |
| 967 | if (highSub == null) { |
| 968 | final boolean REWRITE_TYPEVARS = true; |
| 969 | aHigh = rewriteQuantifiers(a, HIGH, REWRITE_TYPEVARS); |
| 970 | aLow = rewriteQuantifiers(a, LOW, REWRITE_TYPEVARS); |
| 971 | bHigh = rewriteQuantifiers(b, HIGH, REWRITE_TYPEVARS); |
| 972 | bLow = rewriteQuantifiers(b, LOW, REWRITE_TYPEVARS); |
| 973 | lowSub = asSub(bLow, aLow.tsym); |
| 974 | highSub = (lowSub == null) ? null : asSub(bHigh, aHigh.tsym); |
| 975 | } |
| 976 | if (highSub != null) { |
| 977 | assert a.tsym == highSub.tsym && a.tsym == lowSub.tsym |
| 978 | : a.tsym + " != " + highSub.tsym + " != " + lowSub.tsym; |
| 979 | if (!disjointTypes(aHigh.getTypeArguments(), highSub.getTypeArguments()) |
| 980 | && !disjointTypes(aHigh.getTypeArguments(), lowSub.getTypeArguments()) |
| 981 | && !disjointTypes(aLow.getTypeArguments(), highSub.getTypeArguments()) |
| 982 | && !disjointTypes(aLow.getTypeArguments(), lowSub.getTypeArguments())) { |
| 983 | if (upcast ? giveWarning(a, highSub) || giveWarning(a, lowSub) |
| 984 | : giveWarning(highSub, a) || giveWarning(lowSub, a)) |
| 985 | warnStack.head.warnUnchecked(); |
| 986 | return true; |
| 987 | } |
| 988 | } |
| 989 | if (isReifiable(s)) |
| 990 | return isSubtypeUnchecked(a, b); |
| 991 | else |
| 992 | return isSubtypeUnchecked(a, b, warnStack.head); |
| 993 | } |
| 994 | |
| 995 | // Sidecast |
| 996 | if (s.tag == CLASS) { |
| 997 | if ((s.tsym.flags() & INTERFACE) != 0) { |
| 998 | return ((t.tsym.flags() & FINAL) == 0) |
| 999 | ? sideCast(t, s, warnStack.head) |
| 1000 | : sideCastFinal(t, s, warnStack.head); |
| 1001 | } else if ((t.tsym.flags() & INTERFACE) != 0) { |
| 1002 | return ((s.tsym.flags() & FINAL) == 0) |
| 1003 | ? sideCast(t, s, warnStack.head) |
| 1004 | : sideCastFinal(t, s, warnStack.head); |
| 1005 | } else { |
| 1006 | // unrelated class types |
| 1007 | return false; |
| 1008 | } |
| 1009 | } |
| 1010 | } |
| 1011 | return false; |
| 1012 | } |
| 1013 | |
| 1014 | @Override |
| 1015 | public Boolean visitArrayType(ArrayType t, Type s) { |
| 1016 | switch (s.tag) { |
| 1017 | case ERROR: |
| 1018 | case BOT: |
| 1019 | return true; |
| 1020 | case TYPEVAR: |
| 1021 | if (isCastable(s, t, Warner.noWarnings)) { |
| 1022 | warnStack.head.warnUnchecked(); |
| 1023 | return true; |
| 1024 | } else { |
| 1025 | return false; |
| 1026 | } |
| 1027 | case CLASS: |
| 1028 | return isSubtype(t, s); |
| 1029 | case ARRAY: |
| 1030 | if (elemtype(t).tag <= lastBaseTag) { |
| 1031 | return elemtype(t).tag == elemtype(s).tag; |
| 1032 | } else { |
| 1033 | return visit(elemtype(t), elemtype(s)); |
| 1034 | } |
| 1035 | default: |
| 1036 | return false; |
| 1037 | } |
| 1038 | } |
| 1039 | |
| 1040 | @Override |
| 1041 | public Boolean visitTypeVar(TypeVar t, Type s) { |
| 1042 | switch (s.tag) { |
| 1043 | case ERROR: |
| 1044 | case BOT: |
| 1045 | return true; |
| 1046 | case TYPEVAR: |
| 1047 | if (isSubtype(t, s)) { |
| 1048 | return true; |
| 1049 | } else if (isCastable(t.bound, s, Warner.noWarnings)) { |
| 1050 | warnStack.head.warnUnchecked(); |
| 1051 | return true; |
| 1052 | } else { |
| 1053 | return false; |
| 1054 | } |
| 1055 | default: |
| 1056 | return isCastable(t.bound, s, warnStack.head); |
| 1057 | } |
| 1058 | } |
| 1059 | |
| 1060 | @Override |
| 1061 | public Boolean visitErrorType(ErrorType t, Type s) { |
| 1062 | return true; |
| 1063 | } |
| 1064 | }; |
| 1065 | // </editor-fold> |
| 1066 | |
| 1067 | // <editor-fold defaultstate="collapsed" desc="disjointTypes"> |
| 1068 | public boolean disjointTypes(List<Type> ts, List<Type> ss) { |
| 1069 | while (ts.tail != null && ss.tail != null) { |
| 1070 | if (disjointType(ts.head, ss.head)) return true; |
| 1071 | ts = ts.tail; |
| 1072 | ss = ss.tail; |
| 1073 | } |
| 1074 | return false; |
| 1075 | } |
| 1076 | |
| 1077 | /** |
| 1078 | * Two types or wildcards are considered disjoint if it can be |
| 1079 | * proven that no type can be contained in both. It is |
| 1080 | * conservative in that it is allowed to say that two types are |
| 1081 | * not disjoint, even though they actually are. |
| 1082 | * |
| 1083 | * The type C<X> is castable to C<Y> exactly if X and Y are not |
| 1084 | * disjoint. |
| 1085 | */ |
| 1086 | public boolean disjointType(Type t, Type s) { |
| 1087 | return disjointType.visit(t, s); |
| 1088 | } |
| 1089 | // where |
| 1090 | private TypeRelation disjointType = new TypeRelation() { |
| 1091 | |
| 1092 | private Set<TypePair> cache = new HashSet<TypePair>(); |
| 1093 | |
| 1094 | public Boolean visitType(Type t, Type s) { |
| 1095 | if (s.tag == WILDCARD) |
| 1096 | return visit(s, t); |
| 1097 | else |
| 1098 | return notSoftSubtypeRecursive(t, s) || notSoftSubtypeRecursive(s, t); |
| 1099 | } |
| 1100 | |
| 1101 | private boolean isCastableRecursive(Type t, Type s) { |
| 1102 | TypePair pair = new TypePair(t, s); |
| 1103 | if (cache.add(pair)) { |
| 1104 | try { |
| 1105 | return Types.this.isCastable(t, s); |
| 1106 | } finally { |
| 1107 | cache.remove(pair); |
| 1108 | } |
| 1109 | } else { |
| 1110 | return true; |
| 1111 | } |
| 1112 | } |
| 1113 | |
| 1114 | private boolean notSoftSubtypeRecursive(Type t, Type s) { |
| 1115 | TypePair pair = new TypePair(t, s); |
| 1116 | if (cache.add(pair)) { |
| 1117 | try { |
| 1118 | return Types.this.notSoftSubtype(t, s); |
| 1119 | } finally { |
| 1120 | cache.remove(pair); |
| 1121 | } |
| 1122 | } else { |
| 1123 | return false; |
| 1124 | } |
| 1125 | } |
| 1126 | |
| 1127 | @Override |
| 1128 | public Boolean visitWildcardType(WildcardType t, Type s) { |
| 1129 | if (t.isUnbound()) |
| 1130 | return false; |
| 1131 | |
| 1132 | if (s.tag != WILDCARD) { |
| 1133 | if (t.isExtendsBound()) |
| 1134 | return notSoftSubtypeRecursive(s, t.type); |
| 1135 | else // isSuperBound() |
| 1136 | return notSoftSubtypeRecursive(t.type, s); |
| 1137 | } |
| 1138 | |
| 1139 | if (s.isUnbound()) |
| 1140 | return false; |
| 1141 | |
| 1142 | if (t.isExtendsBound()) { |
| 1143 | if (s.isExtendsBound()) |
| 1144 | return !isCastableRecursive(t.type, upperBound(s)); |
| 1145 | else if (s.isSuperBound()) |
| 1146 | return notSoftSubtypeRecursive(lowerBound(s), t.type); |
| 1147 | } else if (t.isSuperBound()) { |
| 1148 | if (s.isExtendsBound()) |
| 1149 | return notSoftSubtypeRecursive(t.type, upperBound(s)); |
| 1150 | } |
| 1151 | return false; |
| 1152 | } |
| 1153 | }; |
| 1154 | // </editor-fold> |
| 1155 | |
| 1156 | // <editor-fold defaultstate="collapsed" desc="lowerBoundArgtypes"> |
| 1157 | /** |
| 1158 | * Returns the lower bounds of the formals of a method. |
| 1159 | */ |
| 1160 | public List<Type> lowerBoundArgtypes(Type t) { |
| 1161 | return map(t.getParameterTypes(), lowerBoundMapping); |
| 1162 | } |
| 1163 | private final Mapping lowerBoundMapping = new Mapping("lowerBound") { |
| 1164 | public Type apply(Type t) { |
| 1165 | return lowerBound(t); |
| 1166 | } |
| 1167 | }; |
| 1168 | // </editor-fold> |
| 1169 | |
| 1170 | // <editor-fold defaultstate="collapsed" desc="notSoftSubtype"> |
| 1171 | /** |
| 1172 | * This relation answers the question: is impossible that |
| 1173 | * something of type `t' can be a subtype of `s'? This is |
| 1174 | * different from the question "is `t' not a subtype of `s'?" |
| 1175 | * when type variables are involved: Integer is not a subtype of T |
| 1176 | * where <T extends Number> but it is not true that Integer cannot |
| 1177 | * possibly be a subtype of T. |
| 1178 | */ |
| 1179 | public boolean notSoftSubtype(Type t, Type s) { |
| 1180 | if (t == s) return false; |
| 1181 | if (t.tag == TYPEVAR) { |
| 1182 | TypeVar tv = (TypeVar) t; |
| 1183 | if (s.tag == TYPEVAR) |
| 1184 | s = s.getUpperBound(); |
| 1185 | return !isCastable(tv.bound, |
| 1186 | s, |
| 1187 | Warner.noWarnings); |
| 1188 | } |
| 1189 | if (s.tag != WILDCARD) |
| 1190 | s = upperBound(s); |
| 1191 | if (s.tag == TYPEVAR) |
| 1192 | s = s.getUpperBound(); |
| 1193 | return !isSubtype(t, s); |
| 1194 | } |
| 1195 | // </editor-fold> |
| 1196 | |
| 1197 | // <editor-fold defaultstate="collapsed" desc="isReifiable"> |
| 1198 | public boolean isReifiable(Type t) { |
| 1199 | return isReifiable.visit(t); |
| 1200 | } |
| 1201 | // where |
| 1202 | private UnaryVisitor<Boolean> isReifiable = new UnaryVisitor<Boolean>() { |
| 1203 | |
| 1204 | public Boolean visitType(Type t, Void ignored) { |
| 1205 | return true; |
| 1206 | } |
| 1207 | |
| 1208 | @Override |
| 1209 | public Boolean visitClassType(ClassType t, Void ignored) { |
| 1210 | if (!t.isParameterized()) |
| 1211 | return true; |
| 1212 | |
| 1213 | for (Type param : t.allparams()) { |
| 1214 | if (!param.isUnbound()) |
| 1215 | return false; |
| 1216 | } |
| 1217 | return true; |
| 1218 | } |
| 1219 | |
| 1220 | @Override |
| 1221 | public Boolean visitArrayType(ArrayType t, Void ignored) { |
| 1222 | return visit(t.elemtype); |
| 1223 | } |
| 1224 | |
| 1225 | @Override |
| 1226 | public Boolean visitTypeVar(TypeVar t, Void ignored) { |
| 1227 | return false; |
| 1228 | } |
| 1229 | }; |
| 1230 | // </editor-fold> |
| 1231 | |
| 1232 | // <editor-fold defaultstate="collapsed" desc="Array Utils"> |
| 1233 | public boolean isArray(Type t) { |
| 1234 | while (t.tag == WILDCARD) |
| 1235 | t = upperBound(t); |
| 1236 | return t.tag == ARRAY; |
| 1237 | } |
| 1238 | |
| 1239 | /** |
| 1240 | * The element type of an array. |
| 1241 | */ |
| 1242 | public Type elemtype(Type t) { |
| 1243 | switch (t.tag) { |
| 1244 | case WILDCARD: |
| 1245 | return elemtype(upperBound(t)); |
| 1246 | case ARRAY: |
| 1247 | return ((ArrayType)t).elemtype; |
| 1248 | case FORALL: |
| 1249 | return elemtype(((ForAll)t).qtype); |
| 1250 | case ERROR: |
| 1251 | return t; |
| 1252 | default: |
| 1253 | return null; |
| 1254 | } |
| 1255 | } |
| 1256 | |
| 1257 | /** |
| 1258 | * Mapping to take element type of an arraytype |
| 1259 | */ |
| 1260 | private Mapping elemTypeFun = new Mapping ("elemTypeFun") { |
| 1261 | public Type apply(Type t) { return elemtype(t); } |
| 1262 | }; |
| 1263 | |
| 1264 | /** |
| 1265 | * The number of dimensions of an array type. |
| 1266 | */ |
| 1267 | public int dimensions(Type t) { |
| 1268 | int result = 0; |
| 1269 | while (t.tag == ARRAY) { |
| 1270 | result++; |
| 1271 | t = elemtype(t); |
| 1272 | } |
| 1273 | return result; |
| 1274 | } |
| 1275 | // </editor-fold> |
| 1276 | |
| 1277 | // <editor-fold defaultstate="collapsed" desc="asSuper"> |
| 1278 | /** |
| 1279 | * Return the (most specific) base type of t that starts with the |
| 1280 | * given symbol. If none exists, return null. |
| 1281 | * |
| 1282 | * @param t a type |
| 1283 | * @param sym a symbol |
| 1284 | */ |
| 1285 | public Type asSuper(Type t, Symbol sym) { |
| 1286 | return asSuper.visit(t, sym); |
| 1287 | } |
| 1288 | // where |
| 1289 | private SimpleVisitor<Type,Symbol> asSuper = new SimpleVisitor<Type,Symbol>() { |
| 1290 | |
| 1291 | public Type visitType(Type t, Symbol sym) { |
| 1292 | return null; |
| 1293 | } |
| 1294 | |
| 1295 | @Override |
| 1296 | public Type visitClassType(ClassType t, Symbol sym) { |
| 1297 | if (t.tsym == sym) |
| 1298 | return t; |
| 1299 | |
| 1300 | Type st = supertype(t); |
| 1301 | if (st.tag == CLASS || st.tag == ERROR) { |
| 1302 | Type x = asSuper(st, sym); |
| 1303 | if (x != null) |
| 1304 | return x; |
| 1305 | } |
| 1306 | if ((sym.flags() & INTERFACE) != 0) { |
| 1307 | for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { |
| 1308 | Type x = asSuper(l.head, sym); |
| 1309 | if (x != null) |
| 1310 | return x; |
| 1311 | } |
| 1312 | } |
| 1313 | return null; |
| 1314 | } |
| 1315 | |
| 1316 | @Override |
| 1317 | public Type visitArrayType(ArrayType t, Symbol sym) { |
| 1318 | return isSubtype(t, sym.type) ? sym.type : null; |
| 1319 | } |
| 1320 | |
| 1321 | @Override |
| 1322 | public Type visitTypeVar(TypeVar t, Symbol sym) { |
| 1323 | return asSuper(t.bound, sym); |
| 1324 | } |
| 1325 | |
| 1326 | @Override |
| 1327 | public Type visitErrorType(ErrorType t, Symbol sym) { |
| 1328 | return t; |
| 1329 | } |
| 1330 | }; |
| 1331 | |
| 1332 | /** |
| 1333 | * Return the base type of t or any of its outer types that starts |
| 1334 | * with the given symbol. If none exists, return null. |
| 1335 | * |
| 1336 | * @param t a type |
| 1337 | * @param sym a symbol |
| 1338 | */ |
| 1339 | public Type asOuterSuper(Type t, Symbol sym) { |
| 1340 | switch (t.tag) { |
| 1341 | case CLASS: |
| 1342 | do { |
| 1343 | Type s = asSuper(t, sym); |
| 1344 | if (s != null) return s; |
| 1345 | t = t.getEnclosingType(); |
| 1346 | } while (t.tag == CLASS); |
| 1347 | return null; |
| 1348 | case ARRAY: |
| 1349 | return isSubtype(t, sym.type) ? sym.type : null; |
| 1350 | case TYPEVAR: |
| 1351 | return asSuper(t, sym); |
| 1352 | case ERROR: |
| 1353 | return t; |
| 1354 | default: |
| 1355 | return null; |
| 1356 | } |
| 1357 | } |
| 1358 | |
| 1359 | /** |
| 1360 | * Return the base type of t or any of its enclosing types that |
| 1361 | * starts with the given symbol. If none exists, return null. |
| 1362 | * |
| 1363 | * @param t a type |
| 1364 | * @param sym a symbol |
| 1365 | */ |
| 1366 | public Type asEnclosingSuper(Type t, Symbol sym) { |
| 1367 | switch (t.tag) { |
| 1368 | case CLASS: |
| 1369 | do { |
| 1370 | Type s = asSuper(t, sym); |
| 1371 | if (s != null) return s; |
| 1372 | Type outer = t.getEnclosingType(); |
| 1373 | t = (outer.tag == CLASS) ? outer : |
| 1374 | (t.tsym.owner.enclClass() != null) ? t.tsym.owner.enclClass().type : |
| 1375 | Type.noType; |
| 1376 | } while (t.tag == CLASS); |
| 1377 | return null; |
| 1378 | case ARRAY: |
| 1379 | return isSubtype(t, sym.type) ? sym.type : null; |
| 1380 | case TYPEVAR: |
| 1381 | return asSuper(t, sym); |
| 1382 | case ERROR: |
| 1383 | return t; |
| 1384 | default: |
| 1385 | return null; |
| 1386 | } |
| 1387 | } |
| 1388 | // </editor-fold> |
| 1389 | |
| 1390 | // <editor-fold defaultstate="collapsed" desc="memberType"> |
| 1391 | /** |
| 1392 | * The type of given symbol, seen as a member of t. |
| 1393 | * |
| 1394 | * @param t a type |
| 1395 | * @param sym a symbol |
| 1396 | */ |
| 1397 | public Type memberType(Type t, Symbol sym) { |
| 1398 | return (sym.flags() & STATIC) != 0 |
| 1399 | ? sym.type |
| 1400 | : memberType.visit(t, sym); |
| 1401 | } |
| 1402 | // where |
| 1403 | private SimpleVisitor<Type,Symbol> memberType = new SimpleVisitor<Type,Symbol>() { |
| 1404 | |
| 1405 | public Type visitType(Type t, Symbol sym) { |
| 1406 | return sym.type; |
| 1407 | } |
| 1408 | |
| 1409 | @Override |
| 1410 | public Type visitWildcardType(WildcardType t, Symbol sym) { |
| 1411 | return memberType(upperBound(t), sym); |
| 1412 | } |
| 1413 | |
| 1414 | @Override |
| 1415 | public Type visitClassType(ClassType t, Symbol sym) { |
| 1416 | Symbol owner = sym.owner; |
| 1417 | long flags = sym.flags(); |
| 1418 | if (((flags & STATIC) == 0) && owner.type.isParameterized()) { |
| 1419 | Type base = asOuterSuper(t, owner); |
| 1420 | if (base != null) { |
| 1421 | List<Type> ownerParams = owner.type.allparams(); |
| 1422 | List<Type> baseParams = base.allparams(); |
| 1423 | if (ownerParams.nonEmpty()) { |
| 1424 | if (baseParams.isEmpty()) { |
| 1425 | // then base is a raw type |
| 1426 | return erasure(sym.type); |
| 1427 | } else { |
| 1428 | return subst(sym.type, ownerParams, baseParams); |
| 1429 | } |
| 1430 | } |
| 1431 | } |
| 1432 | } |
| 1433 | return sym.type; |
| 1434 | } |
| 1435 | |
| 1436 | @Override |
| 1437 | public Type visitTypeVar(TypeVar t, Symbol sym) { |
| 1438 | return memberType(t.bound, sym); |
| 1439 | } |
| 1440 | |
| 1441 | @Override |
| 1442 | public Type visitErrorType(ErrorType t, Symbol sym) { |
| 1443 | return t; |
| 1444 | } |
| 1445 | }; |
| 1446 | // </editor-fold> |
| 1447 | |
| 1448 | // <editor-fold defaultstate="collapsed" desc="isAssignable"> |
| 1449 | public boolean isAssignable(Type t, Type s) { |
| 1450 | return isAssignable(t, s, Warner.noWarnings); |
| 1451 | } |
| 1452 | |
| 1453 | /** |
| 1454 | * Is t assignable to s?<br> |
| 1455 | * Equivalent to subtype except for constant values and raw |
| 1456 | * types.<br> |
| 1457 | * (not defined for Method and ForAll types) |
| 1458 | */ |
| 1459 | public boolean isAssignable(Type t, Type s, Warner warn) { |
| 1460 | if (t.tag == ERROR) |
| 1461 | return true; |
| 1462 | if (t.tag <= INT && t.constValue() != null) { |
| 1463 | int value = ((Number)t.constValue()).intValue(); |
| 1464 | switch (s.tag) { |
| 1465 | case BYTE: |
| 1466 | if (Byte.MIN_VALUE <= value && value <= Byte.MAX_VALUE) |
| 1467 | return true; |
| 1468 | break; |
| 1469 | case CHAR: |
| 1470 | if (Character.MIN_VALUE <= value && value <= Character.MAX_VALUE) |
| 1471 | return true; |
| 1472 | break; |
| 1473 | case SHORT: |
| 1474 | if (Short.MIN_VALUE <= value && value <= Short.MAX_VALUE) |
| 1475 | return true; |
| 1476 | break; |
| 1477 | case INT: |
| 1478 | return true; |
| 1479 | case CLASS: |
| 1480 | switch (unboxedType(s).tag) { |
| 1481 | case BYTE: |
| 1482 | case CHAR: |
| 1483 | case SHORT: |
| 1484 | return isAssignable(t, unboxedType(s), warn); |
| 1485 | } |
| 1486 | break; |
| 1487 | } |
| 1488 | } |
| 1489 | return isConvertible(t, s, warn); |
| 1490 | } |
| 1491 | // </editor-fold> |
| 1492 | |
| 1493 | // <editor-fold defaultstate="collapsed" desc="erasure"> |
| 1494 | /** |
| 1495 | * The erasure of t {@code |t|} -- the type that results when all |
| 1496 | * type parameters in t are deleted. |
| 1497 | */ |
| 1498 | public Type erasure(Type t) { |
| 1499 | if (t.tag <= lastBaseTag) |
| 1500 | return t; /* fast special case */ |
| 1501 | else |
| 1502 | return erasure.visit(t); |
| 1503 | } |
| 1504 | // where |
| 1505 | private UnaryVisitor<Type> erasure = new UnaryVisitor<Type>() { |
| 1506 | public Type visitType(Type t, Void ignored) { |
| 1507 | if (t.tag <= lastBaseTag) |
| 1508 | return t; /*fast special case*/ |
| 1509 | else |
| 1510 | return t.map(erasureFun); |
| 1511 | } |
| 1512 | |
| 1513 | @Override |
| 1514 | public Type visitWildcardType(WildcardType t, Void ignored) { |
| 1515 | return erasure(upperBound(t)); |
| 1516 | } |
| 1517 | |
| 1518 | @Override |
| 1519 | public Type visitClassType(ClassType t, Void ignored) { |
| 1520 | return t.tsym.erasure(Types.this); |
| 1521 | } |
| 1522 | |
| 1523 | @Override |
| 1524 | public Type visitTypeVar(TypeVar t, Void ignored) { |
| 1525 | return erasure(t.bound); |
| 1526 | } |
| 1527 | |
| 1528 | @Override |
| 1529 | public Type visitErrorType(ErrorType t, Void ignored) { |
| 1530 | return t; |
| 1531 | } |
| 1532 | }; |
| 1533 | private Mapping erasureFun = new Mapping ("erasure") { |
| 1534 | public Type apply(Type t) { return erasure(t); } |
| 1535 | }; |
| 1536 | |
| 1537 | public List<Type> erasure(List<Type> ts) { |
| 1538 | return Type.map(ts, erasureFun); |
| 1539 | } |
| 1540 | // </editor-fold> |
| 1541 | |
| 1542 | // <editor-fold defaultstate="collapsed" desc="makeCompoundType"> |
| 1543 | /** |
| 1544 | * Make a compound type from non-empty list of types |
| 1545 | * |
| 1546 | * @param bounds the types from which the compound type is formed |
| 1547 | * @param supertype is objectType if all bounds are interfaces, |
| 1548 | * null otherwise. |
| 1549 | */ |
| 1550 | public Type makeCompoundType(List<Type> bounds, |
| 1551 | Type supertype) { |
| 1552 | ClassSymbol bc = |
| 1553 | new ClassSymbol(ABSTRACT|PUBLIC|SYNTHETIC|COMPOUND|ACYCLIC, |
| 1554 | Type.moreInfo |
| 1555 | ? names.fromString(bounds.toString()) |
| 1556 | : names.empty, |
| 1557 | syms.noSymbol); |
| 1558 | if (bounds.head.tag == TYPEVAR) |
| 1559 | // error condition, recover |
| 1560 | bc.erasure_field = syms.objectType; |
| 1561 | else |
| 1562 | bc.erasure_field = erasure(bounds.head); |
| 1563 | bc.members_field = new Scope(bc); |
| 1564 | ClassType bt = (ClassType)bc.type; |
| 1565 | bt.allparams_field = List.nil(); |
| 1566 | if (supertype != null) { |
| 1567 | bt.supertype_field = supertype; |
| 1568 | bt.interfaces_field = bounds; |
| 1569 | } else { |
| 1570 | bt.supertype_field = bounds.head; |
| 1571 | bt.interfaces_field = bounds.tail; |
| 1572 | } |
| 1573 | assert bt.supertype_field.tsym.completer != null |
| 1574 | || !bt.supertype_field.isInterface() |
| 1575 | : bt.supertype_field; |
| 1576 | return bt; |
| 1577 | } |
| 1578 | |
| 1579 | /** |
| 1580 | * Same as {@link #makeCompoundType(List,Type)}, except that the |
| 1581 | * second parameter is computed directly. Note that this might |
| 1582 | * cause a symbol completion. Hence, this version of |
| 1583 | * makeCompoundType may not be called during a classfile read. |
| 1584 | */ |
| 1585 | public Type makeCompoundType(List<Type> bounds) { |
| 1586 | Type supertype = (bounds.head.tsym.flags() & INTERFACE) != 0 ? |
| 1587 | supertype(bounds.head) : null; |
| 1588 | return makeCompoundType(bounds, supertype); |
| 1589 | } |
| 1590 | |
| 1591 | /** |
| 1592 | * A convenience wrapper for {@link #makeCompoundType(List)}; the |
| 1593 | * arguments are converted to a list and passed to the other |
| 1594 | * method. Note that this might cause a symbol completion. |
| 1595 | * Hence, this version of makeCompoundType may not be called |
| 1596 | * during a classfile read. |
| 1597 | */ |
| 1598 | public Type makeCompoundType(Type bound1, Type bound2) { |
| 1599 | return makeCompoundType(List.of(bound1, bound2)); |
| 1600 | } |
| 1601 | // </editor-fold> |
| 1602 | |
| 1603 | // <editor-fold defaultstate="collapsed" desc="supertype"> |
| 1604 | public Type supertype(Type t) { |
| 1605 | return supertype.visit(t); |
| 1606 | } |
| 1607 | // where |
| 1608 | private UnaryVisitor<Type> supertype = new UnaryVisitor<Type>() { |
| 1609 | |
| 1610 | public Type visitType(Type t, Void ignored) { |
| 1611 | // A note on wildcards: there is no good way to |
| 1612 | // determine a supertype for a super bounded wildcard. |
| 1613 | return null; |
| 1614 | } |
| 1615 | |
| 1616 | @Override |
| 1617 | public Type visitClassType(ClassType t, Void ignored) { |
| 1618 | if (t.supertype_field == null) { |
| 1619 | Type supertype = ((ClassSymbol)t.tsym).getSuperclass(); |
| 1620 | // An interface has no superclass; its supertype is Object. |
| 1621 | if (t.isInterface()) |
| 1622 | supertype = ((ClassType)t.tsym.type).supertype_field; |
| 1623 | if (t.supertype_field == null) { |
| 1624 | List<Type> actuals = classBound(t).allparams(); |
| 1625 | List<Type> formals = t.tsym.type.allparams(); |
| 1626 | if (actuals.isEmpty()) { |
| 1627 | if (formals.isEmpty()) |
| 1628 | // Should not happen. See comments below in interfaces |
| 1629 | t.supertype_field = supertype; |
| 1630 | else |
| 1631 | t.supertype_field = erasure(supertype); |
| 1632 | } else { |
| 1633 | t.supertype_field = subst(supertype, formals, actuals); |
| 1634 | } |
| 1635 | } |
| 1636 | } |
| 1637 | return t.supertype_field; |
| 1638 | } |
| 1639 | |
| 1640 | /** |
| 1641 | * The supertype is always a class type. If the type |
| 1642 | * variable's bounds start with a class type, this is also |
| 1643 | * the supertype. Otherwise, the supertype is |
| 1644 | * java.lang.Object. |
| 1645 | */ |
| 1646 | @Override |
| 1647 | public Type visitTypeVar(TypeVar t, Void ignored) { |
| 1648 | if (t.bound.tag == TYPEVAR || |
| 1649 | (!t.bound.isCompound() && !t.bound.isInterface())) { |
| 1650 | return t.bound; |
| 1651 | } else { |
| 1652 | return supertype(t.bound); |
| 1653 | } |
| 1654 | } |
| 1655 | |
| 1656 | @Override |
| 1657 | public Type visitArrayType(ArrayType t, Void ignored) { |
| 1658 | if (t.elemtype.isPrimitive() || isSameType(t.elemtype, syms.objectType)) |
| 1659 | return arraySuperType(); |
| 1660 | else |
| 1661 | return new ArrayType(supertype(t.elemtype), t.tsym); |
| 1662 | } |
| 1663 | |
| 1664 | @Override |
| 1665 | public Type visitErrorType(ErrorType t, Void ignored) { |
| 1666 | return t; |
| 1667 | } |
| 1668 | }; |
| 1669 | // </editor-fold> |
| 1670 | |
| 1671 | // <editor-fold defaultstate="collapsed" desc="interfaces"> |
| 1672 | /** |
| 1673 | * Return the interfaces implemented by this class. |
| 1674 | */ |
| 1675 | public List<Type> interfaces(Type t) { |
| 1676 | return interfaces.visit(t); |
| 1677 | } |
| 1678 | // where |
| 1679 | private UnaryVisitor<List<Type>> interfaces = new UnaryVisitor<List<Type>>() { |
| 1680 | |
| 1681 | public List<Type> visitType(Type t, Void ignored) { |
| 1682 | return List.nil(); |
| 1683 | } |
| 1684 | |
| 1685 | @Override |
| 1686 | public List<Type> visitClassType(ClassType t, Void ignored) { |
| 1687 | if (t.interfaces_field == null) { |
| 1688 | List<Type> interfaces = ((ClassSymbol)t.tsym).getInterfaces(); |
| 1689 | if (t.interfaces_field == null) { |
| 1690 | // If t.interfaces_field is null, then t must |
| 1691 | // be a parameterized type (not to be confused |
| 1692 | // with a generic type declaration). |
| 1693 | // Terminology: |
| 1694 | // Parameterized type: List<String> |
| 1695 | // Generic type declaration: class List<E> { ... } |
| 1696 | // So t corresponds to List<String> and |
| 1697 | // t.tsym.type corresponds to List<E>. |
| 1698 | // The reason t must be parameterized type is |
| 1699 | // that completion will happen as a side |
| 1700 | // effect of calling |
| 1701 | // ClassSymbol.getInterfaces. Since |
| 1702 | // t.interfaces_field is null after |
| 1703 | // completion, we can assume that t is not the |
| 1704 | // type of a class/interface declaration. |
| 1705 | assert t != t.tsym.type : t.toString(); |
| 1706 | List<Type> actuals = t.allparams(); |
| 1707 | List<Type> formals = t.tsym.type.allparams(); |
| 1708 | if (actuals.isEmpty()) { |
| 1709 | if (formals.isEmpty()) { |
| 1710 | // In this case t is not generic (nor raw). |
| 1711 | // So this should not happen. |
| 1712 | t.interfaces_field = interfaces; |
| 1713 | } else { |
| 1714 | t.interfaces_field = erasure(interfaces); |
| 1715 | } |
| 1716 | } else { |
| 1717 | t.interfaces_field = |
| 1718 | upperBounds(subst(interfaces, formals, actuals)); |
| 1719 | } |
| 1720 | } |
| 1721 | } |
| 1722 | return t.interfaces_field; |
| 1723 | } |
| 1724 | |
| 1725 | @Override |
| 1726 | public List<Type> visitTypeVar(TypeVar t, Void ignored) { |
| 1727 | if (t.bound.isCompound()) |
| 1728 | return interfaces(t.bound); |
| 1729 | |
| 1730 | if (t.bound.isInterface()) |
| 1731 | return List.of(t.bound); |
| 1732 | |
| 1733 | return List.nil(); |
| 1734 | } |
| 1735 | }; |
| 1736 | // </editor-fold> |
| 1737 | |
| 1738 | // <editor-fold defaultstate="collapsed" desc="isDerivedRaw"> |
| 1739 | Map<Type,Boolean> isDerivedRawCache = new HashMap<Type,Boolean>(); |
| 1740 | |
| 1741 | public boolean isDerivedRaw(Type t) { |
| 1742 | Boolean result = isDerivedRawCache.get(t); |
| 1743 | if (result == null) { |
| 1744 | result = isDerivedRawInternal(t); |
| 1745 | isDerivedRawCache.put(t, result); |
| 1746 | } |
| 1747 | return result; |
| 1748 | } |
| 1749 | |
| 1750 | public boolean isDerivedRawInternal(Type t) { |
| 1751 | if (t.isErroneous()) |
| 1752 | return false; |
| 1753 | return |
| 1754 | t.isRaw() || |
| 1755 | supertype(t) != null && isDerivedRaw(supertype(t)) || |
| 1756 | isDerivedRaw(interfaces(t)); |
| 1757 | } |
| 1758 | |
| 1759 | public boolean isDerivedRaw(List<Type> ts) { |
| 1760 | List<Type> l = ts; |
| 1761 | while (l.nonEmpty() && !isDerivedRaw(l.head)) l = l.tail; |
| 1762 | return l.nonEmpty(); |
| 1763 | } |
| 1764 | // </editor-fold> |
| 1765 | |
| 1766 | // <editor-fold defaultstate="collapsed" desc="setBounds"> |
| 1767 | /** |
| 1768 | * Set the bounds field of the given type variable to reflect a |
| 1769 | * (possibly multiple) list of bounds. |
| 1770 | * @param t a type variable |
| 1771 | * @param bounds the bounds, must be nonempty |
| 1772 | * @param supertype is objectType if all bounds are interfaces, |
| 1773 | * null otherwise. |
| 1774 | */ |
| 1775 | public void setBounds(TypeVar t, List<Type> bounds, Type supertype) { |
| 1776 | if (bounds.tail.isEmpty()) |
| 1777 | t.bound = bounds.head; |
| 1778 | else |
| 1779 | t.bound = makeCompoundType(bounds, supertype); |
| 1780 | t.rank_field = -1; |
| 1781 | } |
| 1782 | |
| 1783 | /** |
| 1784 | * Same as {@link #setBounds(Type.TypeVar,List,Type)}, except that |
| 1785 | * third parameter is computed directly. Note that this test |
| 1786 | * might cause a symbol completion. Hence, this version of |
| 1787 | * setBounds may not be called during a classfile read. |
| 1788 | */ |
| 1789 | public void setBounds(TypeVar t, List<Type> bounds) { |
| 1790 | Type supertype = (bounds.head.tsym.flags() & INTERFACE) != 0 ? |
| 1791 | supertype(bounds.head) : null; |
| 1792 | setBounds(t, bounds, supertype); |
| 1793 | t.rank_field = -1; |
| 1794 | } |
| 1795 | // </editor-fold> |
| 1796 | |
| 1797 | // <editor-fold defaultstate="collapsed" desc="getBounds"> |
| 1798 | /** |
| 1799 | * Return list of bounds of the given type variable. |
| 1800 | */ |
| 1801 | public List<Type> getBounds(TypeVar t) { |
| 1802 | if (t.bound.isErroneous() || !t.bound.isCompound()) |
| 1803 | return List.of(t.bound); |
| 1804 | else if ((erasure(t).tsym.flags() & INTERFACE) == 0) |
| 1805 | return interfaces(t).prepend(supertype(t)); |
| 1806 | else |
| 1807 | // No superclass was given in bounds. |
| 1808 | // In this case, supertype is Object, erasure is first interface. |
| 1809 | return interfaces(t); |
| 1810 | } |
| 1811 | // </editor-fold> |
| 1812 | |
| 1813 | // <editor-fold defaultstate="collapsed" desc="classBound"> |
| 1814 | /** |
| 1815 | * If the given type is a (possibly selected) type variable, |
| 1816 | * return the bounding class of this type, otherwise return the |
| 1817 | * type itself. |
| 1818 | */ |
| 1819 | public Type classBound(Type t) { |
| 1820 | return classBound.visit(t); |
| 1821 | } |
| 1822 | // where |
| 1823 | private UnaryVisitor<Type> classBound = new UnaryVisitor<Type>() { |
| 1824 | |
| 1825 | public Type visitType(Type t, Void ignored) { |
| 1826 | return t; |
| 1827 | } |
| 1828 | |
| 1829 | @Override |
| 1830 | public Type visitClassType(ClassType t, Void ignored) { |
| 1831 | Type outer1 = classBound(t.getEnclosingType()); |
| 1832 | if (outer1 != t.getEnclosingType()) |
| 1833 | return new ClassType(outer1, t.getTypeArguments(), t.tsym); |
| 1834 | else |
| 1835 | return t; |
| 1836 | } |
| 1837 | |
| 1838 | @Override |
| 1839 | public Type visitTypeVar(TypeVar t, Void ignored) { |
| 1840 | return classBound(supertype(t)); |
| 1841 | } |
| 1842 | |
| 1843 | @Override |
| 1844 | public Type visitErrorType(ErrorType t, Void ignored) { |
| 1845 | return t; |
| 1846 | } |
| 1847 | }; |
| 1848 | // </editor-fold> |
| 1849 | |
| 1850 | // <editor-fold defaultstate="collapsed" desc="sub signature / override equivalence"> |
| 1851 | /** |
| 1852 | * Returns true iff the first signature is a <em>sub |
| 1853 | * signature</em> of the other. This is <b>not</b> an equivalence |
| 1854 | * relation. |
| 1855 | * |
| 1856 | * @see "The Java Language Specification, Third Ed. (8.4.2)." |
| 1857 | * @see #overrideEquivalent(Type t, Type s) |
| 1858 | * @param t first signature (possibly raw). |
| 1859 | * @param s second signature (could be subjected to erasure). |
| 1860 | * @return true if t is a sub signature of s. |
| 1861 | */ |
| 1862 | public boolean isSubSignature(Type t, Type s) { |
| 1863 | return hasSameArgs(t, s) || hasSameArgs(t, erasure(s)); |
| 1864 | } |
| 1865 | |
| 1866 | /** |
| 1867 | * Returns true iff these signatures are related by <em>override |
| 1868 | * equivalence</em>. This is the natural extension of |
| 1869 | * isSubSignature to an equivalence relation. |
| 1870 | * |
| 1871 | * @see "The Java Language Specification, Third Ed. (8.4.2)." |
| 1872 | * @see #isSubSignature(Type t, Type s) |
| 1873 | * @param t a signature (possible raw, could be subjected to |
| 1874 | * erasure). |
| 1875 | * @param s a signature (possible raw, could be subjected to |
| 1876 | * erasure). |
| 1877 | * @return true if either argument is a sub signature of the other. |
| 1878 | */ |
| 1879 | public boolean overrideEquivalent(Type t, Type s) { |
| 1880 | return hasSameArgs(t, s) || |
| 1881 | hasSameArgs(t, erasure(s)) || hasSameArgs(erasure(t), s); |
| 1882 | } |
| 1883 | |
| 1884 | /** |
| 1885 | * Does t have the same arguments as s? It is assumed that both |
| 1886 | * types are (possibly polymorphic) method types. Monomorphic |
| 1887 | * method types "have the same arguments", if their argument lists |
| 1888 | * are equal. Polymorphic method types "have the same arguments", |
| 1889 | * if they have the same arguments after renaming all type |
| 1890 | * variables of one to corresponding type variables in the other, |
| 1891 | * where correspondence is by position in the type parameter list. |
| 1892 | */ |
| 1893 | public boolean hasSameArgs(Type t, Type s) { |
| 1894 | return hasSameArgs.visit(t, s); |
| 1895 | } |
| 1896 | // where |
| 1897 | private TypeRelation hasSameArgs = new TypeRelation() { |
| 1898 | |
| 1899 | public Boolean visitType(Type t, Type s) { |
| 1900 | throw new AssertionError(); |
| 1901 | } |
| 1902 | |
| 1903 | @Override |
| 1904 | public Boolean visitMethodType(MethodType t, Type s) { |
| 1905 | return s.tag == METHOD |
| 1906 | && containsTypeEquivalent(t.argtypes, s.getParameterTypes()); |
| 1907 | } |
| 1908 | |
| 1909 | @Override |
| 1910 | public Boolean visitForAll(ForAll t, Type s) { |
| 1911 | if (s.tag != FORALL) |
| 1912 | return false; |
| 1913 | |
| 1914 | ForAll forAll = (ForAll)s; |
| 1915 | return hasSameBounds(t, forAll) |
| 1916 | && visit(t.qtype, subst(forAll.qtype, forAll.tvars, t.tvars)); |
| 1917 | } |
| 1918 | |
| 1919 | @Override |
| 1920 | public Boolean visitErrorType(ErrorType t, Type s) { |
| 1921 | return false; |
| 1922 | } |
| 1923 | }; |
| 1924 | // </editor-fold> |
| 1925 | |
| 1926 | // <editor-fold defaultstate="collapsed" desc="subst"> |
| 1927 | public List<Type> subst(List<Type> ts, |
| 1928 | List<Type> from, |
| 1929 | List<Type> to) { |
| 1930 | return new Subst(from, to).subst(ts); |
| 1931 | } |
| 1932 | |
| 1933 | /** |
| 1934 | * Substitute all occurrences of a type in `from' with the |
| 1935 | * corresponding type in `to' in 't'. Match lists `from' and `to' |
| 1936 | * from the right: If lists have different length, discard leading |
| 1937 | * elements of the longer list. |
| 1938 | */ |
| 1939 | public Type subst(Type t, List<Type> from, List<Type> to) { |
| 1940 | return new Subst(from, to).subst(t); |
| 1941 | } |
| 1942 | |
| 1943 | private class Subst extends UnaryVisitor<Type> { |
| 1944 | List<Type> from; |
| 1945 | List<Type> to; |
| 1946 | |
| 1947 | public Subst(List<Type> from, List<Type> to) { |
| 1948 | int fromLength = from.length(); |
| 1949 | int toLength = to.length(); |
| 1950 | while (fromLength > toLength) { |
| 1951 | fromLength--; |
| 1952 | from = from.tail; |
| 1953 | } |
| 1954 | while (fromLength < toLength) { |
| 1955 | toLength--; |
| 1956 | to = to.tail; |
| 1957 | } |
| 1958 | this.from = from; |
| 1959 | this.to = to; |
| 1960 | } |
| 1961 | |
| 1962 | Type subst(Type t) { |
| 1963 | if (from.tail == null) |
| 1964 | return t; |
| 1965 | else |
| 1966 | return visit(t); |
| 1967 | } |
| 1968 | |
| 1969 | List<Type> subst(List<Type> ts) { |
| 1970 | if (from.tail == null) |
| 1971 | return ts; |
| 1972 | boolean wild = false; |
| 1973 | if (ts.nonEmpty() && from.nonEmpty()) { |
| 1974 | Type head1 = subst(ts.head); |
| 1975 | List<Type> tail1 = subst(ts.tail); |
| 1976 | if (head1 != ts.head || tail1 != ts.tail) |
| 1977 | return tail1.prepend(head1); |
| 1978 | } |
| 1979 | return ts; |
| 1980 | } |
| 1981 | |
| 1982 | public Type visitType(Type t, Void ignored) { |
| 1983 | return t; |
| 1984 | } |
| 1985 | |
| 1986 | @Override |
| 1987 | public Type visitMethodType(MethodType t, Void ignored) { |
| 1988 | List<Type> argtypes = subst(t.argtypes); |
| 1989 | Type restype = subst(t.restype); |
| 1990 | List<Type> thrown = subst(t.thrown); |
| 1991 | if (argtypes == t.argtypes && |
| 1992 | restype == t.restype && |
| 1993 | thrown == t.thrown) |
| 1994 | return t; |
| 1995 | else |
| 1996 | return new MethodType(argtypes, restype, thrown, t.tsym); |
| 1997 | } |
| 1998 | |
| 1999 | @Override |
| 2000 | public Type visitTypeVar(TypeVar t, Void ignored) { |
| 2001 | for (List<Type> from = this.from, to = this.to; |
| 2002 | from.nonEmpty(); |
| 2003 | from = from.tail, to = to.tail) { |
| 2004 | if (t == from.head) { |
| 2005 | return to.head.withTypeVar(t); |
| 2006 | } |
| 2007 | } |
| 2008 | return t; |
| 2009 | } |
| 2010 | |
| 2011 | @Override |
| 2012 | public Type visitClassType(ClassType t, Void ignored) { |
| 2013 | if (!t.isCompound()) { |
| 2014 | List<Type> typarams = t.getTypeArguments(); |
| 2015 | List<Type> typarams1 = subst(typarams); |
| 2016 | Type outer = t.getEnclosingType(); |
| 2017 | Type outer1 = subst(outer); |
| 2018 | if (typarams1 == typarams && outer1 == outer) |
| 2019 | return t; |
| 2020 | else |
| 2021 | return new ClassType(outer1, typarams1, t.tsym); |
| 2022 | } else { |
| 2023 | Type st = subst(supertype(t)); |
| 2024 | List<Type> is = upperBounds(subst(interfaces(t))); |
| 2025 | if (st == supertype(t) && is == interfaces(t)) |
| 2026 | return t; |
| 2027 | else |
| 2028 | return makeCompoundType(is.prepend(st)); |
| 2029 | } |
| 2030 | } |
| 2031 | |
| 2032 | @Override |
| 2033 | public Type visitWildcardType(WildcardType t, Void ignored) { |
| 2034 | Type bound = t.type; |
| 2035 | if (t.kind != BoundKind.UNBOUND) |
| 2036 | bound = subst(bound); |
| 2037 | if (bound == t.type) { |
| 2038 | return t; |
| 2039 | } else { |
| 2040 | if (t.isExtendsBound() && bound.isExtendsBound()) |
| 2041 | bound = upperBound(bound); |
| 2042 | return new WildcardType(bound, t.kind, syms.boundClass, t.bound); |
| 2043 | } |
| 2044 | } |
| 2045 | |
| 2046 | @Override |
| 2047 | public Type visitArrayType(ArrayType t, Void ignored) { |
| 2048 | Type elemtype = subst(t.elemtype); |
| 2049 | if (elemtype == t.elemtype) |
| 2050 | return t; |
| 2051 | else |
| 2052 | return new ArrayType(upperBound(elemtype), t.tsym); |
| 2053 | } |
| 2054 | |
| 2055 | @Override |
| 2056 | public Type visitForAll(ForAll t, Void ignored) { |
| 2057 | List<Type> tvars1 = substBounds(t.tvars, from, to); |
| 2058 | Type qtype1 = subst(t.qtype); |
| 2059 | if (tvars1 == t.tvars && qtype1 == t.qtype) { |
| 2060 | return t; |
| 2061 | } else if (tvars1 == t.tvars) { |
| 2062 | return new ForAll(tvars1, qtype1); |
| 2063 | } else { |
| 2064 | return new ForAll(tvars1, Types.this.subst(qtype1, t.tvars, tvars1)); |
| 2065 | } |
| 2066 | } |
| 2067 | |
| 2068 | @Override |
| 2069 | public Type visitErrorType(ErrorType t, Void ignored) { |
| 2070 | return t; |
| 2071 | } |
| 2072 | } |
| 2073 | |
| 2074 | public List<Type> substBounds(List<Type> tvars, |
| 2075 | List<Type> from, |
| 2076 | List<Type> to) { |
| 2077 | if (tvars.isEmpty()) |
| 2078 | return tvars; |
| 2079 | if (tvars.tail.isEmpty()) |
| 2080 | // fast common case |
| 2081 | return List.<Type>of(substBound((TypeVar)tvars.head, from, to)); |
| 2082 | ListBuffer<Type> newBoundsBuf = lb(); |
| 2083 | boolean changed = false; |
| 2084 | // calculate new bounds |
| 2085 | for (Type t : tvars) { |
| 2086 | TypeVar tv = (TypeVar) t; |
| 2087 | Type bound = subst(tv.bound, from, to); |
| 2088 | if (bound != tv.bound) |
| 2089 | changed = true; |
| 2090 | newBoundsBuf.append(bound); |
| 2091 | } |
| 2092 | if (!changed) |
| 2093 | return tvars; |
| 2094 | ListBuffer<Type> newTvars = lb(); |
| 2095 | // create new type variables without bounds |
| 2096 | for (Type t : tvars) { |
| 2097 | newTvars.append(new TypeVar(t.tsym, null, syms.botType)); |
| 2098 | } |
| 2099 | // the new bounds should use the new type variables in place |
| 2100 | // of the old |
| 2101 | List<Type> newBounds = newBoundsBuf.toList(); |
| 2102 | from = tvars; |
| 2103 | to = newTvars.toList(); |
| 2104 | for (; !newBounds.isEmpty(); newBounds = newBounds.tail) { |
| 2105 | newBounds.head = subst(newBounds.head, from, to); |
| 2106 | } |
| 2107 | newBounds = newBoundsBuf.toList(); |
| 2108 | // set the bounds of new type variables to the new bounds |
| 2109 | for (Type t : newTvars.toList()) { |
| 2110 | TypeVar tv = (TypeVar) t; |
| 2111 | tv.bound = newBounds.head; |
| 2112 | newBounds = newBounds.tail; |
| 2113 | } |
| 2114 | return newTvars.toList(); |
| 2115 | } |
| 2116 | |
| 2117 | public TypeVar substBound(TypeVar t, List<Type> from, List<Type> to) { |
| 2118 | Type bound1 = subst(t.bound, from, to); |
| 2119 | if (bound1 == t.bound) |
| 2120 | return t; |
| 2121 | else |
| 2122 | return new TypeVar(t.tsym, bound1, syms.botType); |
| 2123 | } |
| 2124 | // </editor-fold> |
| 2125 | |
| 2126 | // <editor-fold defaultstate="collapsed" desc="hasSameBounds"> |
| 2127 | /** |
| 2128 | * Does t have the same bounds for quantified variables as s? |
| 2129 | */ |
| 2130 | boolean hasSameBounds(ForAll t, ForAll s) { |
| 2131 | List<Type> l1 = t.tvars; |
| 2132 | List<Type> l2 = s.tvars; |
| 2133 | while (l1.nonEmpty() && l2.nonEmpty() && |
| 2134 | isSameType(l1.head.getUpperBound(), |
| 2135 | subst(l2.head.getUpperBound(), |
| 2136 | s.tvars, |
| 2137 | t.tvars))) { |
| 2138 | l1 = l1.tail; |
| 2139 | l2 = l2.tail; |
| 2140 | } |
| 2141 | return l1.isEmpty() && l2.isEmpty(); |
| 2142 | } |
| 2143 | // </editor-fold> |
| 2144 | |
| 2145 | // <editor-fold defaultstate="collapsed" desc="newInstances"> |
| 2146 | /** Create new vector of type variables from list of variables |
| 2147 | * changing all recursive bounds from old to new list. |
| 2148 | */ |
| 2149 | public List<Type> newInstances(List<Type> tvars) { |
| 2150 | List<Type> tvars1 = Type.map(tvars, newInstanceFun); |
| 2151 | for (List<Type> l = tvars1; l.nonEmpty(); l = l.tail) { |
| 2152 | TypeVar tv = (TypeVar) l.head; |
| 2153 | tv.bound = subst(tv.bound, tvars, tvars1); |
| 2154 | } |
| 2155 | return tvars1; |
| 2156 | } |
| 2157 | static private Mapping newInstanceFun = new Mapping("newInstanceFun") { |
| 2158 | public Type apply(Type t) { return new TypeVar(t.tsym, t.getUpperBound(), t.getLowerBound()); } |
| 2159 | }; |
| 2160 | // </editor-fold> |
| 2161 | |
| 2162 | // <editor-fold defaultstate="collapsed" desc="rank"> |
| 2163 | /** |
| 2164 | * The rank of a class is the length of the longest path between |
| 2165 | * the class and java.lang.Object in the class inheritance |
| 2166 | * graph. Undefined for all but reference types. |
| 2167 | */ |
| 2168 | public int rank(Type t) { |
| 2169 | switch(t.tag) { |
| 2170 | case CLASS: { |
| 2171 | ClassType cls = (ClassType)t; |
| 2172 | if (cls.rank_field < 0) { |
| 2173 | Name fullname = cls.tsym.getQualifiedName(); |
| 2174 | if (fullname == fullname.table.java_lang_Object) |
| 2175 | cls.rank_field = 0; |
| 2176 | else { |
| 2177 | int r = rank(supertype(cls)); |
| 2178 | for (List<Type> l = interfaces(cls); |
| 2179 | l.nonEmpty(); |
| 2180 | l = l.tail) { |
| 2181 | if (rank(l.head) > r) |
| 2182 | r = rank(l.head); |
| 2183 | } |
| 2184 | cls.rank_field = r + 1; |
| 2185 | } |
| 2186 | } |
| 2187 | return cls.rank_field; |
| 2188 | } |
| 2189 | case TYPEVAR: { |
| 2190 | TypeVar tvar = (TypeVar)t; |
| 2191 | if (tvar.rank_field < 0) { |
| 2192 | int r = rank(supertype(tvar)); |
| 2193 | for (List<Type> l = interfaces(tvar); |
| 2194 | l.nonEmpty(); |
| 2195 | l = l.tail) { |
| 2196 | if (rank(l.head) > r) r = rank(l.head); |
| 2197 | } |
| 2198 | tvar.rank_field = r + 1; |
| 2199 | } |
| 2200 | return tvar.rank_field; |
| 2201 | } |
| 2202 | case ERROR: |
| 2203 | return 0; |
| 2204 | default: |
| 2205 | throw new AssertionError(); |
| 2206 | } |
| 2207 | } |
| 2208 | // </editor-fold> |
| 2209 | |
| 2210 | // <editor-fold defaultstate="collapsed" desc="toString"> |
| 2211 | /** |
| 2212 | * This toString is slightly more descriptive than the one on Type. |
| 2213 | */ |
| 2214 | public String toString(Type t) { |
| 2215 | if (t.tag == FORALL) { |
| 2216 | ForAll forAll = (ForAll)t; |
| 2217 | return typaramsString(forAll.tvars) + forAll.qtype; |
| 2218 | } |
| 2219 | return "" + t; |
| 2220 | } |
| 2221 | // where |
| 2222 | private String typaramsString(List<Type> tvars) { |
| 2223 | StringBuffer s = new StringBuffer(); |
| 2224 | s.append('<'); |
| 2225 | boolean first = true; |
| 2226 | for (Type t : tvars) { |
| 2227 | if (!first) s.append(", "); |
| 2228 | first = false; |
| 2229 | appendTyparamString(((TypeVar)t), s); |
| 2230 | } |
| 2231 | s.append('>'); |
| 2232 | return s.toString(); |
| 2233 | } |
| 2234 | private void appendTyparamString(TypeVar t, StringBuffer buf) { |
| 2235 | buf.append(t); |
| 2236 | if (t.bound == null || |
| 2237 | t.bound.tsym.getQualifiedName() == names.java_lang_Object) |
| 2238 | return; |
| 2239 | buf.append(" extends "); // Java syntax; no need for i18n |
| 2240 | Type bound = t.bound; |
| 2241 | if (!bound.isCompound()) { |
| 2242 | buf.append(bound); |
| 2243 | } else if ((erasure(t).tsym.flags() & INTERFACE) == 0) { |
| 2244 | buf.append(supertype(t)); |
| 2245 | for (Type intf : interfaces(t)) { |
| 2246 | buf.append('&'); |
| 2247 | buf.append(intf); |
| 2248 | } |
| 2249 | } else { |
| 2250 | // No superclass was given in bounds. |
| 2251 | // In this case, supertype is Object, erasure is first interface. |
| 2252 | boolean first = true; |
| 2253 | for (Type intf : interfaces(t)) { |
| 2254 | if (!first) buf.append('&'); |
| 2255 | first = false; |
| 2256 | buf.append(intf); |
| 2257 | } |
| 2258 | } |
| 2259 | } |
| 2260 | // </editor-fold> |
| 2261 | |
| 2262 | // <editor-fold defaultstate="collapsed" desc="Determining least upper bounds of types"> |
| 2263 | /** |
| 2264 | * A cache for closures. |
| 2265 | * |
| 2266 | * <p>A closure is a list of all the supertypes and interfaces of |
| 2267 | * a class or interface type, ordered by ClassSymbol.precedes |
| 2268 | * (that is, subclasses come first, arbitrary but fixed |
| 2269 | * otherwise). |
| 2270 | */ |
| 2271 | private Map<Type,List<Type>> closureCache = new HashMap<Type,List<Type>>(); |
| 2272 | |
| 2273 | /** |
| 2274 | * Returns the closure of a class or interface type. |
| 2275 | */ |
| 2276 | public List<Type> closure(Type t) { |
| 2277 | List<Type> cl = closureCache.get(t); |
| 2278 | if (cl == null) { |
| 2279 | Type st = supertype(t); |
| 2280 | if (!t.isCompound()) { |
| 2281 | if (st.tag == CLASS) { |
| 2282 | cl = insert(closure(st), t); |
| 2283 | } else if (st.tag == TYPEVAR) { |
| 2284 | cl = closure(st).prepend(t); |
| 2285 | } else { |
| 2286 | cl = List.of(t); |
| 2287 | } |
| 2288 | } else { |
| 2289 | cl = closure(supertype(t)); |
| 2290 | } |
| 2291 | for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) |
| 2292 | cl = union(cl, closure(l.head)); |
| 2293 | closureCache.put(t, cl); |
| 2294 | } |
| 2295 | return cl; |
| 2296 | } |
| 2297 | |
| 2298 | /** |
| 2299 | * Insert a type in a closure |
| 2300 | */ |
| 2301 | public List<Type> insert(List<Type> cl, Type t) { |
| 2302 | if (cl.isEmpty() || t.tsym.precedes(cl.head.tsym, this)) { |
| 2303 | return cl.prepend(t); |
| 2304 | } else if (cl.head.tsym.precedes(t.tsym, this)) { |
| 2305 | return insert(cl.tail, t).prepend(cl.head); |
| 2306 | } else { |
| 2307 | return cl; |
| 2308 | } |
| 2309 | } |
| 2310 | |
| 2311 | /** |
| 2312 | * Form the union of two closures |
| 2313 | */ |
| 2314 | public List<Type> union(List<Type> cl1, List<Type> cl2) { |
| 2315 | if (cl1.isEmpty()) { |
| 2316 | return cl2; |
| 2317 | } else if (cl2.isEmpty()) { |
| 2318 | return cl1; |
| 2319 | } else if (cl1.head.tsym.precedes(cl2.head.tsym, this)) { |
| 2320 | return union(cl1.tail, cl2).prepend(cl1.head); |
| 2321 | } else if (cl2.head.tsym.precedes(cl1.head.tsym, this)) { |
| 2322 | return union(cl1, cl2.tail).prepend(cl2.head); |
| 2323 | } else { |
| 2324 | return union(cl1.tail, cl2.tail).prepend(cl1.head); |
| 2325 | } |
| 2326 | } |
| 2327 | |
| 2328 | /** |
| 2329 | * Intersect two closures |
| 2330 | */ |
| 2331 | public List<Type> intersect(List<Type> cl1, List<Type> cl2) { |
| 2332 | if (cl1 == cl2) |
| 2333 | return cl1; |
| 2334 | if (cl1.isEmpty() || cl2.isEmpty()) |
| 2335 | return List.nil(); |
| 2336 | if (cl1.head.tsym.precedes(cl2.head.tsym, this)) |
| 2337 | return intersect(cl1.tail, cl2); |
| 2338 | if (cl2.head.tsym.precedes(cl1.head.tsym, this)) |
| 2339 | return intersect(cl1, cl2.tail); |
| 2340 | if (isSameType(cl1.head, cl2.head)) |
| 2341 | return intersect(cl1.tail, cl2.tail).prepend(cl1.head); |
| 2342 | if (cl1.head.tsym == cl2.head.tsym && |
| 2343 | cl1.head.tag == CLASS && cl2.head.tag == CLASS) { |
| 2344 | if (cl1.head.isParameterized() && cl2.head.isParameterized()) { |
| 2345 | Type merge = merge(cl1.head,cl2.head); |
| 2346 | return intersect(cl1.tail, cl2.tail).prepend(merge); |
| 2347 | } |
| 2348 | if (cl1.head.isRaw() || cl2.head.isRaw()) |
| 2349 | return intersect(cl1.tail, cl2.tail).prepend(erasure(cl1.head)); |
| 2350 | } |
| 2351 | return intersect(cl1.tail, cl2.tail); |
| 2352 | } |
| 2353 | // where |
| 2354 | class TypePair { |
| 2355 | final Type t1; |
| 2356 | final Type t2; |
| 2357 | TypePair(Type t1, Type t2) { |
| 2358 | this.t1 = t1; |
| 2359 | this.t2 = t2; |
| 2360 | } |
| 2361 | @Override |
| 2362 | public int hashCode() { |
| 2363 | return 127 * Types.this.hashCode(t1) + Types.this.hashCode(t2); |
| 2364 | } |
| 2365 | @Override |
| 2366 | public boolean equals(Object obj) { |
| 2367 | if (!(obj instanceof TypePair)) |
| 2368 | return false; |
| 2369 | TypePair typePair = (TypePair)obj; |
| 2370 | return isSameType(t1, typePair.t1) |
| 2371 | && isSameType(t2, typePair.t2); |
| 2372 | } |
| 2373 | } |
| 2374 | Set<TypePair> mergeCache = new HashSet<TypePair>(); |
| 2375 | private Type merge(Type c1, Type c2) { |
| 2376 | ClassType class1 = (ClassType) c1; |
| 2377 | List<Type> act1 = class1.getTypeArguments(); |
| 2378 | ClassType class2 = (ClassType) c2; |
| 2379 | List<Type> act2 = class2.getTypeArguments(); |
| 2380 | ListBuffer<Type> merged = new ListBuffer<Type>(); |
| 2381 | List<Type> typarams = class1.tsym.type.getTypeArguments(); |
| 2382 | |
| 2383 | while (act1.nonEmpty() && act2.nonEmpty() && typarams.nonEmpty()) { |
| 2384 | if (containsType(act1.head, act2.head)) { |
| 2385 | merged.append(act1.head); |
| 2386 | } else if (containsType(act2.head, act1.head)) { |
| 2387 | merged.append(act2.head); |
| 2388 | } else { |
| 2389 | TypePair pair = new TypePair(c1, c2); |
| 2390 | Type m; |
| 2391 | if (mergeCache.add(pair)) { |
| 2392 | m = new WildcardType(lub(upperBound(act1.head), |
| 2393 | upperBound(act2.head)), |
| 2394 | BoundKind.EXTENDS, |
| 2395 | syms.boundClass); |
| 2396 | mergeCache.remove(pair); |
| 2397 | } else { |
| 2398 | m = new WildcardType(syms.objectType, |
| 2399 | BoundKind.UNBOUND, |
| 2400 | syms.boundClass); |
| 2401 | } |
| 2402 | merged.append(m.withTypeVar(typarams.head)); |
| 2403 | } |
| 2404 | act1 = act1.tail; |
| 2405 | act2 = act2.tail; |
| 2406 | typarams = typarams.tail; |
| 2407 | } |
| 2408 | assert(act1.isEmpty() && act2.isEmpty() && typarams.isEmpty()); |
| 2409 | return new ClassType(class1.getEnclosingType(), merged.toList(), class1.tsym); |
| 2410 | } |
| 2411 | |
| 2412 | /** |
| 2413 | * Return the minimum type of a closure, a compound type if no |
| 2414 | * unique minimum exists. |
| 2415 | */ |
| 2416 | private Type compoundMin(List<Type> cl) { |
| 2417 | if (cl.isEmpty()) return syms.objectType; |
| 2418 | List<Type> compound = closureMin(cl); |
| 2419 | if (compound.isEmpty()) |
| 2420 | return null; |
| 2421 | else if (compound.tail.isEmpty()) |
| 2422 | return compound.head; |
| 2423 | else |
| 2424 | return makeCompoundType(compound); |
| 2425 | } |
| 2426 | |
| 2427 | /** |
| 2428 | * Return the minimum types of a closure, suitable for computing |
| 2429 | * compoundMin or glb. |
| 2430 | */ |
| 2431 | private List<Type> closureMin(List<Type> cl) { |
| 2432 | ListBuffer<Type> classes = lb(); |
| 2433 | ListBuffer<Type> interfaces = lb(); |
| 2434 | while (!cl.isEmpty()) { |
| 2435 | Type current = cl.head; |
| 2436 | if (current.isInterface()) |
| 2437 | interfaces.append(current); |
| 2438 | else |
| 2439 | classes.append(current); |
| 2440 | ListBuffer<Type> candidates = lb(); |
| 2441 | for (Type t : cl.tail) { |
| 2442 | if (!isSubtypeNoCapture(current, t)) |
| 2443 | candidates.append(t); |
| 2444 | } |
| 2445 | cl = candidates.toList(); |
| 2446 | } |
| 2447 | return classes.appendList(interfaces).toList(); |
| 2448 | } |
| 2449 | |
| 2450 | /** |
| 2451 | * Return the least upper bound of pair of types. if the lub does |
| 2452 | * not exist return null. |
| 2453 | */ |
| 2454 | public Type lub(Type t1, Type t2) { |
| 2455 | return lub(List.of(t1, t2)); |
| 2456 | } |
| 2457 | |
| 2458 | /** |
| 2459 | * Return the least upper bound (lub) of set of types. If the lub |
| 2460 | * does not exist return the type of null (bottom). |
| 2461 | */ |
| 2462 | public Type lub(List<Type> ts) { |
| 2463 | final int ARRAY_BOUND = 1; |
| 2464 | final int CLASS_BOUND = 2; |
| 2465 | int boundkind = 0; |
| 2466 | for (Type t : ts) { |
| 2467 | switch (t.tag) { |
| 2468 | case CLASS: |
| 2469 | boundkind |= CLASS_BOUND; |
| 2470 | break; |
| 2471 | case ARRAY: |
| 2472 | boundkind |= ARRAY_BOUND; |
| 2473 | break; |
| 2474 | case TYPEVAR: |
| 2475 | do { |
| 2476 | t = t.getUpperBound(); |
| 2477 | } while (t.tag == TYPEVAR); |
| 2478 | if (t.tag == ARRAY) { |
| 2479 | boundkind |= ARRAY_BOUND; |
| 2480 | } else { |
| 2481 | boundkind |= CLASS_BOUND; |
| 2482 | } |
| 2483 | break; |
| 2484 | default: |
| 2485 | if (t.isPrimitive()) |
| 2486 | return syms.botType; |
| 2487 | } |
| 2488 | } |
| 2489 | switch (boundkind) { |
| 2490 | case 0: |
| 2491 | return syms.botType; |
| 2492 | |
| 2493 | case ARRAY_BOUND: |
| 2494 | // calculate lub(A[], B[]) |
| 2495 | List<Type> elements = Type.map(ts, elemTypeFun); |
| 2496 | for (Type t : elements) { |
| 2497 | if (t.isPrimitive()) { |
| 2498 | // if a primitive type is found, then return |
| 2499 | // arraySuperType unless all the types are the |
| 2500 | // same |
| 2501 | Type first = ts.head; |
| 2502 | for (Type s : ts.tail) { |
| 2503 | if (!isSameType(first, s)) { |
| 2504 | // lub(int[], B[]) is Cloneable & Serializable |
| 2505 | return arraySuperType(); |
| 2506 | } |
| 2507 | } |
| 2508 | // all the array types are the same, return one |
| 2509 | // lub(int[], int[]) is int[] |
| 2510 | return first; |
| 2511 | } |
| 2512 | } |
| 2513 | // lub(A[], B[]) is lub(A, B)[] |
| 2514 | return new ArrayType(lub(elements), syms.arrayClass); |
| 2515 | |
| 2516 | case CLASS_BOUND: |
| 2517 | // calculate lub(A, B) |
| 2518 | while (ts.head.tag != CLASS && ts.head.tag != TYPEVAR) |
| 2519 | ts = ts.tail; |
| 2520 | assert !ts.isEmpty(); |
| 2521 | List<Type> cl = closure(ts.head); |
| 2522 | for (Type t : ts.tail) { |
| 2523 | if (t.tag == CLASS || t.tag == TYPEVAR) |
| 2524 | cl = intersect(cl, closure(t)); |
| 2525 | } |
| 2526 | return compoundMin(cl); |
| 2527 | |
| 2528 | default: |
| 2529 | // calculate lub(A, B[]) |
| 2530 | List<Type> classes = List.of(arraySuperType()); |
| 2531 | for (Type t : ts) { |
| 2532 | if (t.tag != ARRAY) // Filter out any arrays |
| 2533 | classes = classes.prepend(t); |
| 2534 | } |
| 2535 | // lub(A, B[]) is lub(A, arraySuperType) |
| 2536 | return lub(classes); |
| 2537 | } |
| 2538 | } |
| 2539 | // where |
| 2540 | private Type arraySuperType = null; |
| 2541 | private Type arraySuperType() { |
| 2542 | // initialized lazily to avoid problems during compiler startup |
| 2543 | if (arraySuperType == null) { |
| 2544 | synchronized (this) { |
| 2545 | if (arraySuperType == null) { |
| 2546 | // JLS 10.8: all arrays implement Cloneable and Serializable. |
| 2547 | arraySuperType = makeCompoundType(List.of(syms.serializableType, |
| 2548 | syms.cloneableType), |
| 2549 | syms.objectType); |
| 2550 | } |
| 2551 | } |
| 2552 | } |
| 2553 | return arraySuperType; |
| 2554 | } |
| 2555 | // </editor-fold> |
| 2556 | |
| 2557 | // <editor-fold defaultstate="collapsed" desc="Greatest lower bound"> |
| 2558 | public Type glb(Type t, Type s) { |
| 2559 | if (s == null) |
| 2560 | return t; |
| 2561 | else if (isSubtypeNoCapture(t, s)) |
| 2562 | return t; |
| 2563 | else if (isSubtypeNoCapture(s, t)) |
| 2564 | return s; |
| 2565 | |
| 2566 | List<Type> closure = union(closure(t), closure(s)); |
| 2567 | List<Type> bounds = closureMin(closure); |
| 2568 | |
| 2569 | if (bounds.isEmpty()) { // length == 0 |
| 2570 | return syms.objectType; |
| 2571 | } else if (bounds.tail.isEmpty()) { // length == 1 |
| 2572 | return bounds.head; |
| 2573 | } else { // length > 1 |
| 2574 | int classCount = 0; |
| 2575 | for (Type bound : bounds) |
| 2576 | if (!bound.isInterface()) |
| 2577 | classCount++; |
| 2578 | if (classCount > 1) |
| 2579 | return syms.errType; |
| 2580 | } |
| 2581 | return makeCompoundType(bounds); |
| 2582 | } |
| 2583 | // </editor-fold> |
| 2584 | |
| 2585 | // <editor-fold defaultstate="collapsed" desc="hashCode"> |
| 2586 | /** |
| 2587 | * Compute a hash code on a type. |
| 2588 | */ |
| 2589 | public static int hashCode(Type t) { |
| 2590 | return hashCode.visit(t); |
| 2591 | } |
| 2592 | // where |
| 2593 | private static final UnaryVisitor<Integer> hashCode = new UnaryVisitor<Integer>() { |
| 2594 | |
| 2595 | public Integer visitType(Type t, Void ignored) { |
| 2596 | return t.tag; |
| 2597 | } |
| 2598 | |
| 2599 | @Override |
| 2600 | public Integer visitClassType(ClassType t, Void ignored) { |
| 2601 | int result = visit(t.getEnclosingType()); |
| 2602 | result *= 127; |
| 2603 | result += t.tsym.flatName().hashCode(); |
| 2604 | for (Type s : t.getTypeArguments()) { |
| 2605 | result *= 127; |
| 2606 | result += visit(s); |
| 2607 | } |
| 2608 | return result; |
| 2609 | } |
| 2610 | |
| 2611 | @Override |
| 2612 | public Integer visitWildcardType(WildcardType t, Void ignored) { |
| 2613 | int result = t.kind.hashCode(); |
| 2614 | if (t.type != null) { |
| 2615 | result *= 127; |
| 2616 | result += visit(t.type); |
| 2617 | } |
| 2618 | return result; |
| 2619 | } |
| 2620 | |
| 2621 | @Override |
| 2622 | public Integer visitArrayType(ArrayType t, Void ignored) { |
| 2623 | return visit(t.elemtype) + 12; |
| 2624 | } |
| 2625 | |
| 2626 | @Override |
| 2627 | public Integer visitTypeVar(TypeVar t, Void ignored) { |
| 2628 | return System.identityHashCode(t.tsym); |
| 2629 | } |
| 2630 | |
| 2631 | @Override |
| 2632 | public Integer visitUndetVar(UndetVar t, Void ignored) { |
| 2633 | return System.identityHashCode(t); |
| 2634 | } |
| 2635 | |
| 2636 | @Override |
| 2637 | public Integer visitErrorType(ErrorType t, Void ignored) { |
| 2638 | return 0; |
| 2639 | } |
| 2640 | }; |
| 2641 | // </editor-fold> |
| 2642 | |
| 2643 | // <editor-fold defaultstate="collapsed" desc="Return-Type-Substitutable"> |
| 2644 | /** |
| 2645 | * Does t have a result that is a subtype of the result type of s, |
| 2646 | * suitable for covariant returns? It is assumed that both types |
| 2647 | * are (possibly polymorphic) method types. Monomorphic method |
| 2648 | * types are handled in the obvious way. Polymorphic method types |
| 2649 | * require renaming all type variables of one to corresponding |
| 2650 | * type variables in the other, where correspondence is by |
| 2651 | * position in the type parameter list. */ |
| 2652 | public boolean resultSubtype(Type t, Type s, Warner warner) { |
| 2653 | List<Type> tvars = t.getTypeArguments(); |
| 2654 | List<Type> svars = s.getTypeArguments(); |
| 2655 | Type tres = t.getReturnType(); |
| 2656 | Type sres = subst(s.getReturnType(), svars, tvars); |
| 2657 | return covariantReturnType(tres, sres, warner); |
| 2658 | } |
| 2659 | |
| 2660 | /** |
| 2661 | * Return-Type-Substitutable. |
| 2662 | * @see <a href="http://java.sun.com/docs/books/jls/">The Java |
| 2663 | * Language Specification, Third Ed. (8.4.5)</a> |
| 2664 | */ |
| 2665 | public boolean returnTypeSubstitutable(Type r1, Type r2) { |
| 2666 | if (hasSameArgs(r1, r2)) |
| 2667 | return resultSubtype(r1, r2, Warner.noWarnings); |
| 2668 | else |
| 2669 | return covariantReturnType(r1.getReturnType(), |
| 2670 | erasure(r2.getReturnType()), |
| 2671 | Warner.noWarnings); |
| 2672 | } |
| 2673 | |
| 2674 | public boolean returnTypeSubstitutable(Type r1, |
| 2675 | Type r2, Type r2res, |
| 2676 | Warner warner) { |
| 2677 | if (isSameType(r1.getReturnType(), r2res)) |
| 2678 | return true; |
| 2679 | if (r1.getReturnType().isPrimitive() || r2res.isPrimitive()) |
| 2680 | return false; |
| 2681 | |
| 2682 | if (hasSameArgs(r1, r2)) |
| 2683 | return covariantReturnType(r1.getReturnType(), r2res, warner); |
| 2684 | if (!source.allowCovariantReturns()) |
| 2685 | return false; |
| 2686 | if (isSubtypeUnchecked(r1.getReturnType(), r2res, warner)) |
| 2687 | return true; |
| 2688 | if (!isSubtype(r1.getReturnType(), erasure(r2res))) |
| 2689 | return false; |
| 2690 | warner.warnUnchecked(); |
| 2691 | return true; |
| 2692 | } |
| 2693 | |
| 2694 | /** |
| 2695 | * Is t an appropriate return type in an overrider for a |
| 2696 | * method that returns s? |
| 2697 | */ |
| 2698 | public boolean covariantReturnType(Type t, Type s, Warner warner) { |
| 2699 | return |
| 2700 | isSameType(t, s) || |
| 2701 | source.allowCovariantReturns() && |
| 2702 | !t.isPrimitive() && |
| 2703 | !s.isPrimitive() && |
| 2704 | isAssignable(t, s, warner); |
| 2705 | } |
| 2706 | // </editor-fold> |
| 2707 | |
| 2708 | // <editor-fold defaultstate="collapsed" desc="Box/unbox support"> |
| 2709 | /** |
| 2710 | * Return the class that boxes the given primitive. |
| 2711 | */ |
| 2712 | public ClassSymbol boxedClass(Type t) { |
| 2713 | return reader.enterClass(syms.boxedName[t.tag]); |
| 2714 | } |
| 2715 | |
| 2716 | /** |
| 2717 | * Return the primitive type corresponding to a boxed type. |
| 2718 | */ |
| 2719 | public Type unboxedType(Type t) { |
| 2720 | if (allowBoxing) { |
| 2721 | for (int i=0; i<syms.boxedName.length; i++) { |
| 2722 | Name box = syms.boxedName[i]; |
| 2723 | if (box != null && |
| 2724 | asSuper(t, reader.enterClass(box)) != null) |
| 2725 | return syms.typeOfTag[i]; |
| 2726 | } |
| 2727 | } |
| 2728 | return Type.noType; |
| 2729 | } |
| 2730 | // </editor-fold> |
| 2731 | |
| 2732 | // <editor-fold defaultstate="collapsed" desc="Capture conversion"> |
| 2733 | /* |
| 2734 | * JLS 3rd Ed. 5.1.10 Capture Conversion: |
| 2735 | * |
| 2736 | * Let G name a generic type declaration with n formal type |
| 2737 | * parameters A1 ... An with corresponding bounds U1 ... Un. There |
| 2738 | * exists a capture conversion from G<T1 ... Tn> to G<S1 ... Sn>, |
| 2739 | * where, for 1 <= i <= n: |
| 2740 | * |
| 2741 | * + If Ti is a wildcard type argument (4.5.1) of the form ? then |
| 2742 | * Si is a fresh type variable whose upper bound is |
| 2743 | * Ui[A1 := S1, ..., An := Sn] and whose lower bound is the null |
| 2744 | * type. |
| 2745 | * |
| 2746 | * + If Ti is a wildcard type argument of the form ? extends Bi, |
| 2747 | * then Si is a fresh type variable whose upper bound is |
| 2748 | * glb(Bi, Ui[A1 := S1, ..., An := Sn]) and whose lower bound is |
| 2749 | * the null type, where glb(V1,... ,Vm) is V1 & ... & Vm. It is |
| 2750 | * a compile-time error if for any two classes (not interfaces) |
| 2751 | * Vi and Vj,Vi is not a subclass of Vj or vice versa. |
| 2752 | * |
| 2753 | * + If Ti is a wildcard type argument of the form ? super Bi, |
| 2754 | * then Si is a fresh type variable whose upper bound is |
| 2755 | * Ui[A1 := S1, ..., An := Sn] and whose lower bound is Bi. |
| 2756 | * |
| 2757 | * + Otherwise, Si = Ti. |
| 2758 | * |
| 2759 | * Capture conversion on any type other than a parameterized type |
| 2760 | * (4.5) acts as an identity conversion (5.1.1). Capture |
| 2761 | * conversions never require a special action at run time and |
| 2762 | * therefore never throw an exception at run time. |
| 2763 | * |
| 2764 | * Capture conversion is not applied recursively. |
| 2765 | */ |
| 2766 | /** |
| 2767 | * Capture conversion as specified by JLS 3rd Ed. |
| 2768 | */ |
| 2769 | public Type capture(Type t) { |
| 2770 | if (t.tag != CLASS) |
| 2771 | return t; |
| 2772 | ClassType cls = (ClassType)t; |
| 2773 | if (cls.isRaw() || !cls.isParameterized()) |
| 2774 | return cls; |
| 2775 | |
| 2776 | ClassType G = (ClassType)cls.asElement().asType(); |
| 2777 | List<Type> A = G.getTypeArguments(); |
| 2778 | List<Type> T = cls.getTypeArguments(); |
| 2779 | List<Type> S = freshTypeVariables(T); |
| 2780 | |
| 2781 | List<Type> currentA = A; |
| 2782 | List<Type> currentT = T; |
| 2783 | List<Type> currentS = S; |
| 2784 | boolean captured = false; |
| 2785 | while (!currentA.isEmpty() && |
| 2786 | !currentT.isEmpty() && |
| 2787 | !currentS.isEmpty()) { |
| 2788 | if (currentS.head != currentT.head) { |
| 2789 | captured = true; |
| 2790 | WildcardType Ti = (WildcardType)currentT.head; |
| 2791 | Type Ui = currentA.head.getUpperBound(); |
| 2792 | CapturedType Si = (CapturedType)currentS.head; |
| 2793 | if (Ui == null) |
| 2794 | Ui = syms.objectType; |
| 2795 | switch (Ti.kind) { |
| 2796 | case UNBOUND: |
| 2797 | Si.bound = subst(Ui, A, S); |
| 2798 | Si.lower = syms.botType; |
| 2799 | break; |
| 2800 | case EXTENDS: |
| 2801 | Si.bound = glb(Ti.getExtendsBound(), subst(Ui, A, S)); |
| 2802 | Si.lower = syms.botType; |
| 2803 | break; |
| 2804 | case SUPER: |
| 2805 | Si.bound = subst(Ui, A, S); |
| 2806 | Si.lower = Ti.getSuperBound(); |
| 2807 | break; |
| 2808 | } |
| 2809 | if (Si.bound == Si.lower) |
| 2810 | currentS.head = Si.bound; |
| 2811 | } |
| 2812 | currentA = currentA.tail; |
| 2813 | currentT = currentT.tail; |
| 2814 | currentS = currentS.tail; |
| 2815 | } |
| 2816 | if (!currentA.isEmpty() || !currentT.isEmpty() || !currentS.isEmpty()) |
| 2817 | return erasure(t); // some "rare" type involved |
| 2818 | |
| 2819 | if (captured) |
| 2820 | return new ClassType(cls.getEnclosingType(), S, cls.tsym); |
| 2821 | else |
| 2822 | return t; |
| 2823 | } |
| 2824 | // where |
| 2825 | private List<Type> freshTypeVariables(List<Type> types) { |
| 2826 | ListBuffer<Type> result = lb(); |
| 2827 | for (Type t : types) { |
| 2828 | if (t.tag == WILDCARD) { |
| 2829 | Type bound = ((WildcardType)t).getExtendsBound(); |
| 2830 | if (bound == null) |
| 2831 | bound = syms.objectType; |
| 2832 | result.append(new CapturedType(capturedName, |
| 2833 | syms.noSymbol, |
| 2834 | bound, |
| 2835 | syms.botType, |
| 2836 | (WildcardType)t)); |
| 2837 | } else { |
| 2838 | result.append(t); |
| 2839 | } |
| 2840 | } |
| 2841 | return result.toList(); |
| 2842 | } |
| 2843 | // </editor-fold> |
| 2844 | |
| 2845 | // <editor-fold defaultstate="collapsed" desc="Internal utility methods"> |
| 2846 | private List<Type> upperBounds(List<Type> ss) { |
| 2847 | if (ss.isEmpty()) return ss; |
| 2848 | Type head = upperBound(ss.head); |
| 2849 | List<Type> tail = upperBounds(ss.tail); |
| 2850 | if (head != ss.head || tail != ss.tail) |
| 2851 | return tail.prepend(head); |
| 2852 | else |
| 2853 | return ss; |
| 2854 | } |
| 2855 | |
| 2856 | private boolean sideCast(Type from, Type to, Warner warn) { |
| 2857 | // We are casting from type $from$ to type $to$, which are |
| 2858 | // non-final unrelated types. This method |
| 2859 | // tries to reject a cast by transferring type parameters |
| 2860 | // from $to$ to $from$ by common superinterfaces. |
| 2861 | boolean reverse = false; |
| 2862 | Type target = to; |
| 2863 | if ((to.tsym.flags() & INTERFACE) == 0) { |
| 2864 | assert (from.tsym.flags() & INTERFACE) != 0; |
| 2865 | reverse = true; |
| 2866 | to = from; |
| 2867 | from = target; |
| 2868 | } |
| 2869 | List<Type> commonSupers = superClosure(to, erasure(from)); |
| 2870 | boolean giveWarning = commonSupers.isEmpty(); |
| 2871 | // The arguments to the supers could be unified here to |
| 2872 | // get a more accurate analysis |
| 2873 | while (commonSupers.nonEmpty()) { |
| 2874 | Type t1 = asSuper(from, commonSupers.head.tsym); |
| 2875 | Type t2 = commonSupers.head; // same as asSuper(to, commonSupers.head.tsym); |
| 2876 | if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) |
| 2877 | return false; |
| 2878 | giveWarning = giveWarning || (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2)); |
| 2879 | commonSupers = commonSupers.tail; |
| 2880 | } |
| 2881 | if (giveWarning && !isReifiable(to)) |
| 2882 | warn.warnUnchecked(); |
| 2883 | if (!source.allowCovariantReturns()) |
| 2884 | // reject if there is a common method signature with |
| 2885 | // incompatible return types. |
| 2886 | chk.checkCompatibleAbstracts(warn.pos(), from, to); |
| 2887 | return true; |
| 2888 | } |
| 2889 | |
| 2890 | private boolean sideCastFinal(Type from, Type to, Warner warn) { |
| 2891 | // We are casting from type $from$ to type $to$, which are |
| 2892 | // unrelated types one of which is final and the other of |
| 2893 | // which is an interface. This method |
| 2894 | // tries to reject a cast by transferring type parameters |
| 2895 | // from the final class to the interface. |
| 2896 | boolean reverse = false; |
| 2897 | Type target = to; |
| 2898 | if ((to.tsym.flags() & INTERFACE) == 0) { |
| 2899 | assert (from.tsym.flags() & INTERFACE) != 0; |
| 2900 | reverse = true; |
| 2901 | to = from; |
| 2902 | from = target; |
| 2903 | } |
| 2904 | assert (from.tsym.flags() & FINAL) != 0; |
| 2905 | Type t1 = asSuper(from, to.tsym); |
| 2906 | if (t1 == null) return false; |
| 2907 | Type t2 = to; |
| 2908 | if (disjointTypes(t1.getTypeArguments(), t2.getTypeArguments())) |
| 2909 | return false; |
| 2910 | if (!source.allowCovariantReturns()) |
| 2911 | // reject if there is a common method signature with |
| 2912 | // incompatible return types. |
| 2913 | chk.checkCompatibleAbstracts(warn.pos(), from, to); |
| 2914 | if (!isReifiable(target) && |
| 2915 | (reverse ? giveWarning(t2, t1) : giveWarning(t1, t2))) |
| 2916 | warn.warnUnchecked(); |
| 2917 | return true; |
| 2918 | } |
| 2919 | |
| 2920 | private boolean giveWarning(Type from, Type to) { |
| 2921 | // To and from are (possibly different) parameterizations |
| 2922 | // of the same class or interface |
| 2923 | return to.isParameterized() && !containsType(to.getTypeArguments(), from.getTypeArguments()); |
| 2924 | } |
| 2925 | |
| 2926 | private List<Type> superClosure(Type t, Type s) { |
| 2927 | List<Type> cl = List.nil(); |
| 2928 | for (List<Type> l = interfaces(t); l.nonEmpty(); l = l.tail) { |
| 2929 | if (isSubtype(s, erasure(l.head))) { |
| 2930 | cl = insert(cl, l.head); |
| 2931 | } else { |
| 2932 | cl = union(cl, superClosure(l.head, s)); |
| 2933 | } |
| 2934 | } |
| 2935 | return cl; |
| 2936 | } |
| 2937 | |
| 2938 | private boolean containsTypeEquivalent(Type t, Type s) { |
| 2939 | return |
| 2940 | isSameType(t, s) || // shortcut |
| 2941 | containsType(t, s) && containsType(s, t); |
| 2942 | } |
| 2943 | |
| 2944 | /** |
| 2945 | * Adapt a type by computing a substitution which maps a source |
| 2946 | * type to a target type. |
| 2947 | * |
| 2948 | * @param source the source type |
| 2949 | * @param target the target type |
| 2950 | * @param from the type variables of the computed substitution |
| 2951 | * @param to the types of the computed substitution. |
| 2952 | */ |
| 2953 | public void adapt(Type source, |
| 2954 | Type target, |
| 2955 | ListBuffer<Type> from, |
| 2956 | ListBuffer<Type> to) throws AdaptFailure { |
| 2957 | Map<Symbol,Type> mapping = new HashMap<Symbol,Type>(); |
| 2958 | adaptRecursive(source, target, from, to, mapping); |
| 2959 | List<Type> fromList = from.toList(); |
| 2960 | List<Type> toList = to.toList(); |
| 2961 | while (!fromList.isEmpty()) { |
| 2962 | Type val = mapping.get(fromList.head.tsym); |
| 2963 | if (toList.head != val) |
| 2964 | toList.head = val; |
| 2965 | fromList = fromList.tail; |
| 2966 | toList = toList.tail; |
| 2967 | } |
| 2968 | } |
| 2969 | // where |
| 2970 | private void adaptRecursive(Type source, |
| 2971 | Type target, |
| 2972 | ListBuffer<Type> from, |
| 2973 | ListBuffer<Type> to, |
| 2974 | Map<Symbol,Type> mapping) throws AdaptFailure { |
| 2975 | if (source.tag == TYPEVAR) { |
| 2976 | // Check to see if there is |
| 2977 | // already a mapping for $source$, in which case |
| 2978 | // the old mapping will be merged with the new |
| 2979 | Type val = mapping.get(source.tsym); |
| 2980 | if (val != null) { |
| 2981 | if (val.isSuperBound() && target.isSuperBound()) { |
| 2982 | val = isSubtype(lowerBound(val), lowerBound(target)) |
| 2983 | ? target : val; |
| 2984 | } else if (val.isExtendsBound() && target.isExtendsBound()) { |
| 2985 | val = isSubtype(upperBound(val), upperBound(target)) |
| 2986 | ? val : target; |
| 2987 | } else if (!isSameType(val, target)) { |
| 2988 | throw new AdaptFailure(); |
| 2989 | } |
| 2990 | } else { |
| 2991 | val = target; |
| 2992 | from.append(source); |
| 2993 | to.append(target); |
| 2994 | } |
| 2995 | mapping.put(source.tsym, val); |
| 2996 | } else if (source.tag == target.tag) { |
| 2997 | switch (source.tag) { |
| 2998 | case CLASS: |
| 2999 | adapt(source.allparams(), target.allparams(), |
| 3000 | from, to, mapping); |
| 3001 | break; |
| 3002 | case ARRAY: |
| 3003 | adaptRecursive(elemtype(source), elemtype(target), |
| 3004 | from, to, mapping); |
| 3005 | break; |
| 3006 | case WILDCARD: |
| 3007 | if (source.isExtendsBound()) { |
| 3008 | adaptRecursive(upperBound(source), upperBound(target), |
| 3009 | from, to, mapping); |
| 3010 | } else if (source.isSuperBound()) { |
| 3011 | adaptRecursive(lowerBound(source), lowerBound(target), |
| 3012 | from, to, mapping); |
| 3013 | } |
| 3014 | break; |
| 3015 | } |
| 3016 | } |
| 3017 | } |
| 3018 | public static class AdaptFailure extends Exception { |
| 3019 | static final long serialVersionUID = -7490231548272701566L; |
| 3020 | } |
| 3021 | |
| 3022 | /** |
| 3023 | * Adapt a type by computing a substitution which maps a list of |
| 3024 | * source types to a list of target types. |
| 3025 | * |
| 3026 | * @param source the source type |
| 3027 | * @param target the target type |
| 3028 | * @param from the type variables of the computed substitution |
| 3029 | * @param to the types of the computed substitution. |
| 3030 | */ |
| 3031 | private void adapt(List<Type> source, |
| 3032 | List<Type> target, |
| 3033 | ListBuffer<Type> from, |
| 3034 | ListBuffer<Type> to, |
| 3035 | Map<Symbol,Type> mapping) throws AdaptFailure { |
| 3036 | if (source.length() == target.length()) { |
| 3037 | while (source.nonEmpty()) { |
| 3038 | adaptRecursive(source.head, target.head, from, to, mapping); |
| 3039 | source = source.tail; |
| 3040 | target = target.tail; |
| 3041 | } |
| 3042 | } |
| 3043 | } |
| 3044 | |
| 3045 | private void adaptSelf(Type t, |
| 3046 | ListBuffer<Type> from, |
| 3047 | ListBuffer<Type> to) { |
| 3048 | try { |
| 3049 | //if (t.tsym.type != t) |
| 3050 | adapt(t.tsym.type, t, from, to); |
| 3051 | } catch (AdaptFailure ex) { |
| 3052 | // Adapt should never fail calculating a mapping from |
| 3053 | // t.tsym.type to t as there can be no merge problem. |
| 3054 | throw new AssertionError(ex); |
| 3055 | } |
| 3056 | } |
| 3057 | |
| 3058 | /** |
| 3059 | * Rewrite all type variables (universal quantifiers) in the given |
| 3060 | * type to wildcards (existential quantifiers). This is used to |
| 3061 | * determine if a cast is allowed. For example, if high is true |
| 3062 | * and {@code T <: Number}, then {@code List<T>} is rewritten to |
| 3063 | * {@code List<? extends Number>}. Since {@code List<Integer> <: |
| 3064 | * List<? extends Number>} a {@code List<T>} can be cast to {@code |
| 3065 | * List<Integer>} with a warning. |
| 3066 | * @param t a type |
| 3067 | * @param high if true return an upper bound; otherwise a lower |
| 3068 | * bound |
| 3069 | * @param rewriteTypeVars only rewrite captured wildcards if false; |
| 3070 | * otherwise rewrite all type variables |
| 3071 | * @return the type rewritten with wildcards (existential |
| 3072 | * quantifiers) only |
| 3073 | */ |
| 3074 | private Type rewriteQuantifiers(Type t, boolean high, boolean rewriteTypeVars) { |
| 3075 | ListBuffer<Type> from = new ListBuffer<Type>(); |
| 3076 | ListBuffer<Type> to = new ListBuffer<Type>(); |
| 3077 | adaptSelf(t, from, to); |
| 3078 | ListBuffer<Type> rewritten = new ListBuffer<Type>(); |
| 3079 | List<Type> formals = from.toList(); |
| 3080 | boolean changed = false; |
| 3081 | for (Type arg : to.toList()) { |
| 3082 | Type bound; |
| 3083 | if (rewriteTypeVars && arg.tag == TYPEVAR) { |
| 3084 | TypeVar tv = (TypeVar)arg; |
| 3085 | bound = high ? tv.bound : syms.botType; |
| 3086 | } else { |
| 3087 | bound = high ? upperBound(arg) : lowerBound(arg); |
| 3088 | } |
| 3089 | Type newarg = bound; |
| 3090 | if (arg != bound) { |
| 3091 | changed = true; |
| 3092 | newarg = high ? makeExtendsWildcard(bound, (TypeVar)formals.head) |
| 3093 | : makeSuperWildcard(bound, (TypeVar)formals.head); |
| 3094 | } |
| 3095 | rewritten.append(newarg); |
| 3096 | formals = formals.tail; |
| 3097 | } |
| 3098 | if (changed) |
| 3099 | return subst(t.tsym.type, from.toList(), rewritten.toList()); |
| 3100 | else |
| 3101 | return t; |
| 3102 | } |
| 3103 | |
| 3104 | /** |
| 3105 | * Create a wildcard with the given upper (extends) bound; create |
| 3106 | * an unbounded wildcard if bound is Object. |
| 3107 | * |
| 3108 | * @param bound the upper bound |
| 3109 | * @param formal the formal type parameter that will be |
| 3110 | * substituted by the wildcard |
| 3111 | */ |
| 3112 | private WildcardType makeExtendsWildcard(Type bound, TypeVar formal) { |
| 3113 | if (bound == syms.objectType) { |
| 3114 | return new WildcardType(syms.objectType, |
| 3115 | BoundKind.UNBOUND, |
| 3116 | syms.boundClass, |
| 3117 | formal); |
| 3118 | } else { |
| 3119 | return new WildcardType(bound, |
| 3120 | BoundKind.EXTENDS, |
| 3121 | syms.boundClass, |
| 3122 | formal); |
| 3123 | } |
| 3124 | } |
| 3125 | |
| 3126 | /** |
| 3127 | * Create a wildcard with the given lower (super) bound; create an |
| 3128 | * unbounded wildcard if bound is bottom (type of {@code null}). |
| 3129 | * |
| 3130 | * @param bound the lower bound |
| 3131 | * @param formal the formal type parameter that will be |
| 3132 | * substituted by the wildcard |
| 3133 | */ |
| 3134 | private WildcardType makeSuperWildcard(Type bound, TypeVar formal) { |
| 3135 | if (bound.tag == BOT) { |
| 3136 | return new WildcardType(syms.objectType, |
| 3137 | BoundKind.UNBOUND, |
| 3138 | syms.boundClass, |
| 3139 | formal); |
| 3140 | } else { |
| 3141 | return new WildcardType(bound, |
| 3142 | BoundKind.SUPER, |
| 3143 | syms.boundClass, |
| 3144 | formal); |
| 3145 | } |
| 3146 | } |
| 3147 | |
| 3148 | /** |
| 3149 | * A wrapper for a type that allows use in sets. |
| 3150 | */ |
| 3151 | class SingletonType { |
| 3152 | final Type t; |
| 3153 | SingletonType(Type t) { |
| 3154 | this.t = t; |
| 3155 | } |
| 3156 | public int hashCode() { |
| 3157 | return Types.this.hashCode(t); |
| 3158 | } |
| 3159 | public boolean equals(Object obj) { |
| 3160 | return (obj instanceof SingletonType) && |
| 3161 | isSameType(t, ((SingletonType)obj).t); |
| 3162 | } |
| 3163 | public String toString() { |
| 3164 | return t.toString(); |
| 3165 | } |
| 3166 | } |
| 3167 | // </editor-fold> |
| 3168 | |
| 3169 | // <editor-fold defaultstate="collapsed" desc="Visitors"> |
| 3170 | /** |
| 3171 | * A default visitor for types. All visitor methods except |
| 3172 | * visitType are implemented by delegating to visitType. Concrete |
| 3173 | * subclasses must provide an implementation of visitType and can |
| 3174 | * override other methods as needed. |
| 3175 | * |
| 3176 | * @param <R> the return type of the operation implemented by this |
| 3177 | * visitor; use Void if no return type is needed. |
| 3178 | * @param <S> the type of the second argument (the first being the |
| 3179 | * type itself) of the operation implemented by this visitor; use |
| 3180 | * Void if a second argument is not needed. |
| 3181 | */ |
| 3182 | public static abstract class DefaultTypeVisitor<R,S> implements Type.Visitor<R,S> { |
| 3183 | final public R visit(Type t, S s) { return t.accept(this, s); } |
| 3184 | public R visitClassType(ClassType t, S s) { return visitType(t, s); } |
| 3185 | public R visitWildcardType(WildcardType t, S s) { return visitType(t, s); } |
| 3186 | public R visitArrayType(ArrayType t, S s) { return visitType(t, s); } |
| 3187 | public R visitMethodType(MethodType t, S s) { return visitType(t, s); } |
| 3188 | public R visitPackageType(PackageType t, S s) { return visitType(t, s); } |
| 3189 | public R visitTypeVar(TypeVar t, S s) { return visitType(t, s); } |
| 3190 | public R visitCapturedType(CapturedType t, S s) { return visitType(t, s); } |
| 3191 | public R visitForAll(ForAll t, S s) { return visitType(t, s); } |
| 3192 | public R visitUndetVar(UndetVar t, S s) { return visitType(t, s); } |
| 3193 | public R visitErrorType(ErrorType t, S s) { return visitType(t, s); } |
| 3194 | } |
| 3195 | |
| 3196 | /** |
| 3197 | * A <em>simple</em> visitor for types. This visitor is simple as |
| 3198 | * captured wildcards, for-all types (generic methods), and |
| 3199 | * undetermined type variables (part of inference) are hidden. |
| 3200 | * Captured wildcards are hidden by treating them as type |
| 3201 | * variables and the rest are hidden by visiting their qtypes. |
| 3202 | * |
| 3203 | * @param <R> the return type of the operation implemented by this |
| 3204 | * visitor; use Void if no return type is needed. |
| 3205 | * @param <S> the type of the second argument (the first being the |
| 3206 | * type itself) of the operation implemented by this visitor; use |
| 3207 | * Void if a second argument is not needed. |
| 3208 | */ |
| 3209 | public static abstract class SimpleVisitor<R,S> extends DefaultTypeVisitor<R,S> { |
| 3210 | @Override |
| 3211 | public R visitCapturedType(CapturedType t, S s) { |
| 3212 | return visitTypeVar(t, s); |
| 3213 | } |
| 3214 | @Override |
| 3215 | public R visitForAll(ForAll t, S s) { |
| 3216 | return visit(t.qtype, s); |
| 3217 | } |
| 3218 | @Override |
| 3219 | public R visitUndetVar(UndetVar t, S s) { |
| 3220 | return visit(t.qtype, s); |
| 3221 | } |
| 3222 | } |
| 3223 | |
| 3224 | /** |
| 3225 | * A plain relation on types. That is a 2-ary function on the |
| 3226 | * form Type × Type → Boolean. |
| 3227 | * <!-- In plain text: Type x Type -> Boolean --> |
| 3228 | */ |
| 3229 | public static abstract class TypeRelation extends SimpleVisitor<Boolean,Type> {} |
| 3230 | |
| 3231 | /** |
| 3232 | * A convenience visitor for implementing operations that only |
| 3233 | * require one argument (the type itself), that is, unary |
| 3234 | * operations. |
| 3235 | * |
| 3236 | * @param <R> the return type of the operation implemented by this |
| 3237 | * visitor; use Void if no return type is needed. |
| 3238 | */ |
| 3239 | public static abstract class UnaryVisitor<R> extends SimpleVisitor<R,Void> { |
| 3240 | final public R visit(Type t) { return t.accept(this, null); } |
| 3241 | } |
| 3242 | |
| 3243 | /** |
| 3244 | * A visitor for implementing a mapping from types to types. The |
| 3245 | * default behavior of this class is to implement the identity |
| 3246 | * mapping (mapping a type to itself). This can be overridden in |
| 3247 | * subclasses. |
| 3248 | * |
| 3249 | * @param <S> the type of the second argument (the first being the |
| 3250 | * type itself) of this mapping; use Void if a second argument is |
| 3251 | * not needed. |
| 3252 | */ |
| 3253 | public static class MapVisitor<S> extends DefaultTypeVisitor<Type,S> { |
| 3254 | final public Type visit(Type t) { return t.accept(this, null); } |
| 3255 | public Type visitType(Type t, S s) { return t; } |
| 3256 | } |
| 3257 | // </editor-fold> |
| 3258 | } |