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| 1 | namespace Semantic is | |
| 2 | use IO.Std | |
| 3 | ||
| 4 | use Collections.Iterable | |
| 5 | use Collections.Iterator | |
| 6 | ||
| 7 | use Collections.SET | |
| 8 | ||
| 9 | use Pair = Collections.KeyValuePair | |
| 10 | ||
| 11 | use Symbols.Symbol | |
| 12 | use Symbols.Classy | |
| 13 | use Symbols.Function | |
| 14 | use Symbols.FUNCTION_GROUP | |
| 15 | ||
| 16 | use Types.Type | |
| 17 | ||
| 18 | use Logging | |
| 19 | ||
| 20 | use Ghul.Pipes | |
| 21 | ||
| 22 | // TODO this really needs cleaning up. Could use double dispatch between the overrider and the overridee | |
| 23 | // for non-method symbols to determine what to do, which might simplify it a bit | |
| 24 | class SYMBOL_INHERITANCE_RESOLVER is | |
| 25 | ||
| 26 | // One "declared here" related location per symbol - the prose of | |
| 27 | // these diagnostics lists the colliding declarations already; the | |
| 28 | // related locations make each of them a jump target. | |
| 29 | _declared_here(symbols: Iterable[Symbol]) -> Collections.LIST[RELATED_LOCATION] is | |
| 30 | let related = Collections.LIST[RELATED_LOCATION]() | |
| 31 | ||
| 32 | for symbol in symbols do | |
| 33 | related.add(RELATED_LOCATION(symbol.location, "declared here")) | |
| 34 | od | |
| 35 | ||
| 36 | return related | |
| 37 | si | |
| 38 | into: Classy | |
| 39 | ||
| 40 | init(into: Classy) is | |
| 41 | self.into = into | |
| 42 | si | |
| 43 | ||
| 44 | pull_down_super_symbols_into() is | |
| 45 | let logger = IoC.CONTAINER.instance.logger | |
| 46 | ||
| 47 | let members = into.get_all_direct_ancestor_members() | |
| 48 | ||
| 49 | let overridees = get_overridees_map(members) | |
| 50 | ||
| 51 | for p in overridees do | |
| 52 | let overridee_name = p.key | |
| 53 | let overridee_map = p.value | |
| 54 | ||
| 55 | pull_down_for_name(overridee_name, overridee_map, logger) | |
| 56 | od | |
| 57 | si | |
| 58 | ||
| 59 | pull_down_for_name(overridee_name: string, overridee_map: METHOD_OVERRIDE_MAP, logger: Logging.Logger) is | |
| 60 | let overriders = get_overriders_map_for(overridee_name) | |
| 61 | ||
| 62 | let overrider_other_symbol = overriders.first_symbol | |
| 63 | ||
| 64 | let overridee_other_symbols = overridee_map.symbols | |
| 65 | ||
| 66 | if overridee_map.contains_any_methods then | |
| 67 | for overridee_list in overridee_map do | |
| 68 | let overrider_list = overriders[overridee_list.override_class] | |
| 69 | ||
| 70 | try_inherit_including_methods( | |
| 71 | overridee_name, | |
| 72 | overrider_list, | |
| 73 | overrider_other_symbol, | |
| 74 | overridee_list, | |
| 75 | overridee_other_symbols, | |
| 76 | logger | |
| 77 | ) | |
| 78 | od | |
| 79 | ||
| 80 | warn_likely_override_mismatch(overridee_map, overriders, logger) | |
| 81 | elif overridee_map.contains_any_symbols /\ !overriders.contains_any_methods then | |
| 82 | try_inherit_non_methods( | |
| 83 | overridee_name, | |
| 84 | overrider_other_symbol, | |
| 85 | overridee_other_symbols, | |
| 86 | logger | |
| 87 | ) | |
| 88 | fi | |
| 89 | si | |
| 90 | ||
| 91 | // When the derived class declares a method by a name that | |
| 92 | // also exists in an ancestor but with a different signature, | |
| 93 | // ghūl treats it as an overload — even when the derived's | |
| 94 | // argument types are narrower (`LIST[T]` vs `List[T]`, | |
| 95 | // `Cat` vs `Animal`) and the user almost certainly meant | |
| 96 | // to override. There is no `override` keyword to make the | |
| 97 | // intent explicit, so the only way to surface this is a | |
| 98 | // heuristic on the inheritance walk. | |
| 99 | // | |
| 100 | // Heuristic: for each ancestor signature with no exact | |
| 101 | // overrider, check whether any same-named method in the | |
| 102 | // current class has the same arity and arg types that are | |
| 103 | // all subtypes of the ancestor's (with at least one strict | |
| 104 | // narrowing). If so, warn — the user probably intended an | |
| 105 | // override. | |
| 106 | warn_likely_override_mismatch( | |
| 107 | overridees: METHOD_OVERRIDE_MAP, | |
| 108 | overriders: METHOD_OVERRIDE_MAP, | |
| 109 | logger: Logging.Logger | |
| 110 | ) is | |
| 111 | if IoC.CONTAINER.instance.build_flags.no_warn_likely_override_mismatch then | |
| 112 | return | |
| 113 | fi | |
| 114 | ||
| 115 | if into.is_reflected then | |
| 116 | return | |
| 117 | fi | |
| 118 | ||
| 119 | for overridee_set in overridees do | |
| 120 | // Skip when an exact overrider exists — try_override | |
| 121 | // has already handled this signature. | |
| 122 | if overriders[overridee_set.override_class]? then | |
| 123 | continue | |
| 124 | fi | |
| 125 | ||
| 126 | for overridee in overridee_set.iterable do | |
| 127 | if overridee.is_internal \/ overridee.is_reflected then | |
| 128 | continue | |
| 129 | fi | |
| 130 | ||
| 131 | for overrider_set in overriders do | |
| 132 | // Skip when this overrider exactly overrides some | |
| 133 | // *other* same-named base signature. In the visitor | |
| 134 | // double-dispatch pattern the base declares both a | |
| 135 | // catch-all `visit(Node)` and a per-subtype | |
| 136 | // `visit(SpecificNode)`; a subclass's | |
| 137 | // `visit(SpecificNode)` cleanly overrides the | |
| 138 | // specific one and only looks like a narrowing | |
| 139 | // mistake against the catch-all. | |
| 140 | if overridees[overrider_set.override_class]? then | |
| 141 | continue | |
| 142 | fi | |
| 143 | ||
| 144 | for overrider in overrider_set.iterable |> filter(f => f.owner == into /\ !f.is_internal) do | |
| 145 | if is_likely_intended_override(overrider, overridee) then | |
| 146 | logger.warn( | |
| 147 | overrider.location, | |
| 148 | "likely-override-mismatch", | |
| 149 | "{overrider} hides {overridee} due to narrower argument types", | |
| 150 | overridee.location, | |
| 151 | "hidden member declared here") | |
| 152 | fi | |
| 153 | od | |
| 154 | od | |
| 155 | od | |
| 156 | od | |
| 157 | si | |
| 158 | ||
| 159 | // Same arity, every argument's type is a subtype of the | |
| 160 | // overridee's, with at least one strict narrowing. Generic- | |
| 161 | // type-arguments aren't compared — the heuristic stays | |
| 162 | // conservative; method-level generics are rare enough that | |
| 163 | // we don't try to be clever about them. | |
| 164 | is_likely_intended_override(overrider: Function, overridee: Function) -> bool is | |
| 165 | if overrider.arguments.count != overridee.arguments.count then | |
| 166 | return false | |
| 167 | fi | |
| 168 | ||
| 169 | let saw_narrowing mut = false | |
| 170 | ||
| 171 | for i in 0..overrider.arguments.count do | |
| 172 | let rider_arg = overrider.arguments[i] | |
| 173 | let ridee_arg = overridee.arguments[i] | |
| 174 | ||
| 175 | if rider_arg.matches(ridee_arg) then | |
| 176 | continue | |
| 177 | fi | |
| 178 | ||
| 179 | // rider_arg is a subtype of ridee_arg iff ridee_arg | |
| 180 | // can be assigned from rider_arg — MATCH.ASSIGNABLE | |
| 181 | // means "self is assignable from other" (per | |
| 182 | // `feedback_dedup_use_equals_hash`). | |
| 183 | let match = ridee_arg.compare(rider_arg) | |
| 184 | ||
| 185 | if match != Types.MATCH.SAME /\ match != Types.MATCH.ASSIGNABLE then | |
| 186 | return false | |
| 187 | fi | |
| 188 | ||
| 189 | if match == Types.MATCH.ASSIGNABLE then | |
| 190 | saw_narrowing = true | |
| 191 | fi | |
| 192 | od | |
| 193 | ||
| 194 | return saw_narrowing | |
| 195 | si | |
| 196 | ||
| 197 | ||
| 198 | get_overridees_map(members: Collections.LIST[Symbol]) -> Collections.Map[string, METHOD_OVERRIDE_MAP] is | |
| 199 | let overridees = Collections.MAP[string,METHOD_OVERRIDE_MAP]() | |
| 200 | ||
| 201 | for symbol in members do | |
| 202 | let overridees_with_this_name: METHOD_OVERRIDE_MAP mut | |
| 203 | let symbol_name = symbol.name | |
| 204 | ||
| 205 | if !overridees.try_get_value(symbol_name, overridees_with_this_name ref) then | |
| 206 | overridees_with_this_name = METHOD_OVERRIDE_MAP(symbol_name) | |
| 207 | overridees[symbol_name] = overridees_with_this_name | |
| 208 | fi | |
| 209 | ||
| 210 | overridees_with_this_name.add(symbol) | |
| 211 | od | |
| 212 | ||
| 213 | return overridees | |
| 214 | si | |
| 215 | ||
| 216 | try_inherit_including_methods( | |
| 217 | name: string, | |
| 218 | overriders: METHOD_OVERRIDE_SET?, | |
| 219 | other_overrider_symbol: Symbol?, | |
| 220 | overridees: METHOD_OVERRIDE_SET, | |
| 221 | other_overridee_symbols: Iterable[Symbol], | |
| 222 | logger: Logging.Logger | |
| 223 | ) | |
| 224 | is | |
| 225 | let is_reflected = into.is_reflected | |
| 226 | let other_overridee_symbols_count = other_overridee_symbols |> count() | |
| 227 | let overriding_method: Function? mut = null | |
| 228 | ||
| 229 | if overriders? then | |
| 230 | overriding_method = overriders.get_overrider(into) | |
| 231 | fi | |
| 232 | ||
| 233 | if overriding_method? then | |
| 234 | try_override_methods(overriding_method, overridees, other_overridee_symbols, is_reflected, logger) | |
| 235 | elif other_overrider_symbol? then | |
| 236 | handle_non_method_overrider(other_overrider_symbol, overridees, other_overridee_symbols, is_reflected, logger) | |
| 237 | elif other_overridee_symbols_count == 1 /\ overridees.count != 0 then | |
| 238 | into.add_member(other_overridee_symbols |> only()) | |
| 239 | elif other_overridee_symbols_count > 0 then | |
| 240 | handle_multiple_symbols_with_same_name(overridees, other_overridee_symbols, into, logger) | |
| 241 | else | |
| 242 | handle_inherit_nothing_to_override(overridees, other_overridee_symbols, into, logger) | |
| 243 | fi | |
| 244 | si | |
| 245 | ||
| 246 | try_override_methods( | |
| 247 | overriding_method: Function, | |
| 248 | overridees: METHOD_OVERRIDE_SET, | |
| 249 | other_overridee_symbols: Iterable[Symbol], | |
| 250 | is_reflected: bool, | |
| 251 | logger: Logging.Logger | |
| 252 | ) | |
| 253 | is | |
| 254 | for f in overridees.iterable do | |
| 255 | overriding_method.try_override(into, f, logger) | |
| 256 | od | |
| 257 | ||
| 258 | if !is_reflected then | |
| 259 | for os in other_overridee_symbols do | |
| 260 | logger.warn(overriding_method.location, "hides-inherited", "hides {os} (case A)", os.location, "hidden declaration") | |
| 261 | od | |
| 262 | fi | |
| 263 | si | |
| 264 | ||
| 265 | handle_non_method_overrider( | |
| 266 | other_overrider_symbol: Symbol, | |
| 267 | overridees: METHOD_OVERRIDE_SET, | |
| 268 | other_overridee_symbols: Iterable[Symbol], | |
| 269 | is_reflected: bool, | |
| 270 | logger: Logging.Logger | |
| 271 | ) | |
| 272 | is | |
| 273 | if !is_reflected then | |
| 274 | for f in overridees.iterable do | |
| 275 | logger.warn(other_overrider_symbol.location, "hides-inherited", "hides {f} (case B)", f.location, "hidden declaration") | |
| 276 | od | |
| 277 | ||
| 278 | for os in other_overridee_symbols do | |
| 279 | logger.warn(other_overrider_symbol.location, "hides-inherited", "hides {os} (case C)", os.location, "hidden declaration") | |
| 280 | od | |
| 281 | fi | |
| 282 | si | |
| 283 | ||
| 284 | handle_multiple_symbols_with_same_name( | |
| 285 | overridees: METHOD_OVERRIDE_SET, | |
| 286 | other_overridee_symbols: Iterable[Symbol], | |
| 287 | into: Classy, | |
| 288 | logger: Logging.Logger | |
| 289 | ) | |
| 290 | is | |
| 291 | let all_symbols = Collections.LIST[Symbol]() | |
| 292 | ||
| 293 | all_symbols.add_range( | |
| 294 | overridees.iterable |> | |
| 295 | map(function -> Symbol => function) | |
| 296 | ) | |
| 297 | ||
| 298 | all_symbols.add_range(other_overridee_symbols) | |
| 299 | ||
| 300 | logger.error( | |
| 301 | into.location, | |
| 302 | "cannot inherit multiple symbols with the same name: {all_symbols |> sort_by(symbol => symbol.short_description) |> join()}", | |
| 303 | _declared_here(all_symbols) | |
| 304 | ) | |
| 305 | si | |
| 306 | ||
| 307 | handle_inherit_nothing_to_override( | |
| 308 | overridees: METHOD_OVERRIDE_SET, | |
| 309 | other_overridee_symbols: Iterable[Symbol], | |
| 310 | into: Classy, | |
| 311 | logger: Logging.Logger | |
| 312 | ) | |
| 313 | is | |
| 314 | let other_overridee_symbols_count = other_overridee_symbols|> count() | |
| 315 | ||
| 316 | if overridees.count == 1 then | |
| 317 | let first = overridees.iterable |> only() | |
| 318 | first.try_pull_down_into(into, other_overridee_symbols, logger) | |
| 319 | elif overridees.count == 0 then | |
| 320 | if other_overridee_symbols_count == 0 then | |
| 321 | // nothing to do | |
| 322 | elif other_overridee_symbols_count == 1 then | |
| 323 | let first = other_overridee_symbols |> only() | |
| 324 | first.try_pull_down_into(into, other_overridee_symbols, logger) | |
| 325 | else | |
| 326 | for os in other_overridee_symbols do | |
| 327 | os.try_pull_down_into(into, other_overridee_symbols, logger) | |
| 328 | od | |
| 329 | ||
| 330 | logger.error( | |
| 331 | into.location, | |
| 332 | "cannot inherit multiple symbols with the same name: { | |
| 333 | overridees.iterable |> | |
| 334 | map(f => f.to_string()) |> | |
| 335 | sort() |> | |
| 336 | join() | |
| 337 | }", | |
| 338 | _declared_here(other_overridee_symbols) | |
| 339 | ) | |
| 340 | fi | |
| 341 | else | |
| 342 | handle_inherit_multiple_methods(overridees, into, logger) | |
| 343 | fi | |
| 344 | si | |
| 345 | ||
| 346 | handle_inherit_multiple_methods( | |
| 347 | overridees: METHOD_OVERRIDE_SET, | |
| 348 | into: Classy, | |
| 349 | logger: Logging.Logger | |
| 350 | ) | |
| 351 | is | |
| 352 | let concrete: Function? mut = null | |
| 353 | let abstract_method: Function? mut = null | |
| 354 | ||
| 355 | let seen_multiple_concrete mut = false | |
| 356 | let seen_multiple_abstract mut = false | |
| 357 | ||
| 358 | for f in overridees.iterable do | |
| 359 | if f.is_abstract then | |
| 360 | if abstract_method? then | |
| 361 | seen_multiple_abstract = true | |
| 362 | else | |
| 363 | abstract_method = f | |
| 364 | fi | |
| 365 | elif f.is_instance then | |
| 366 | if concrete? /\ f != concrete then | |
| 367 | seen_multiple_concrete = true | |
| 368 | else | |
| 369 | concrete = f | |
| 370 | fi | |
| 371 | fi | |
| 372 | od | |
| 373 | ||
| 374 | if | |
| 375 | seen_multiple_concrete /\ | |
| 376 | overridees.iterable |> | |
| 377 | any(function => function.is_instance /\ !function.is_reflected) | |
| 378 | then | |
| 379 | let concretes = | |
| 380 | overridees.iterable |> | |
| 381 | filter(function => function.is_instance) | |
| 382 | ||
| 383 | logger | |
| 384 | .error( | |
| 385 | into.location, | |
| 386 | "cannot inherit multiple concrete methods: { | |
| 387 | concretes |> | |
| 388 | map(f => f.to_string()) |> | |
| 389 | sort() |> | |
| 390 | join() | |
| 391 | }", | |
| 392 | _declared_here(concretes) | |
| 393 | ) | |
| 394 | ||
| 395 | elif concrete? then | |
| 396 | into.add_member(concrete) | |
| 397 | ||
| 398 | for f in overridees.iterable do | |
| 399 | if f != concrete then | |
| 400 | concrete.try_override(into, f, logger) | |
| 401 | fi | |
| 402 | od | |
| 403 | ||
| 404 | elif seen_multiple_abstract /\ !into.location.is_internal then | |
| 405 | // METHOD_OVERRIDE_SET groups by argument signature. The | |
| 406 | // return types may also align: identical (a single virtual | |
| 407 | // slot) or form a subtype chain (C# 9-style covariant | |
| 408 | // returns on re-declared interface methods — e.g. EF Core's | |
| 409 | // IReadOnlyAnnotatable / IAnnotatable / IConventionAnnotatable | |
| 410 | // chain). In either case one most-derived abstract subsumes | |
| 411 | // the others; pull it down so a single implementation | |
| 412 | // satisfies every inherited slot via .NET's implicit | |
| 413 | // interface implementation. | |
| 414 | let most_derived = most_derived_abstract(overridees) | |
| 415 | ||
| 416 | if most_derived? then | |
| 417 | most_derived.try_pull_down_into(into, Collections.LIST[Symbol](), logger) | |
| 418 | else | |
| 419 | let abstracts = | |
| 420 | overridees.iterable |> | |
| 421 | filter(function => function.is_abstract) | |
| 422 | ||
| 423 | logger.error( | |
| 424 | into.location, | |
| 425 | "cannot inherit multiple abstract methods: { | |
| 426 | abstracts |> | |
| 427 | map(f => f.to_string()) |> | |
| 428 | sort() |> | |
| 429 | join() | |
| 430 | }", | |
| 431 | _declared_here(abstracts) | |
| 432 | ) | |
| 433 | fi | |
| 434 | ||
| 435 | elif abstract_method? then | |
| 436 | into.add_member(abstract_method) | |
| 437 | fi | |
| 438 | si | |
| 439 | ||
| 440 | // If the inherited abstracts share name+args (guaranteed by | |
| 441 | // METHOD_OVERRIDE_SET grouping) AND their return types form a | |
| 442 | // single subtype chain — identical types being the degenerate | |
| 443 | // one-link case — returns the most-derived abstract. Returns | |
| 444 | // null when the return types are unrelated (not in a chain), | |
| 445 | // which is the genuine error case. | |
| 446 | most_derived_abstract(overridees: METHOD_OVERRIDE_SET) -> Function? is | |
| 447 | let abstracts = Collections.LIST[Function]() | |
| 448 | ||
| 449 | for f in overridees.iterable do | |
| 450 | if f.is_abstract then | |
| 451 | abstracts.add(f) | |
| 452 | fi | |
| 453 | od | |
| 454 | ||
| 455 | let most_derived = | |
| 456 | MOST_DERIVED_TYPE_SELECTOR() | |
| 457 | .select(abstracts |> map(f -> Type? => f.return_type)) | |
| 458 | ||
| 459 | if most_derived < 0 then | |
| 460 | return null | |
| 461 | fi | |
| 462 | ||
| 463 | return abstracts[most_derived] | |
| 464 | si | |
| 465 | ||
| 466 | try_inherit_non_methods( | |
| 467 | name: string, | |
| 468 | overrider_symbol: Symbol?, | |
| 469 | overridee_symbols: Iterable[Symbol], | |
| 470 | logger: Logging.Logger | |
| 471 | ) | |
| 472 | is | |
| 473 | if overrider_symbol? then | |
| 474 | if isa Symbols.Property(overrider_symbol) then | |
| 475 | handle_property_overrider( | |
| 476 | overrider_symbol, overridee_symbols, logger) | |
| 477 | else | |
| 478 | handle_non_property_overrider(overrider_symbol, overridee_symbols, logger) | |
| 479 | fi | |
| 480 | ||
| 481 | return | |
| 482 | fi | |
| 483 | ||
| 484 | let count = overridee_symbols |> count() | |
| 485 | ||
| 486 | if count == 1 then | |
| 487 | let first = overridee_symbols |> only() | |
| 488 | ||
| 489 | into.add_member(first) | |
| 490 | elif count > 1 then | |
| 491 | handle_multiple_overridee_symbols(overridee_symbols, logger) | |
| 492 | fi | |
| 493 | si | |
| 494 | ||
| 495 | handle_property_overrider( | |
| 496 | overrider_symbol: Symbols.Property, | |
| 497 | overridee_symbols: Iterable[Symbol], | |
| 498 | logger: Logging.Logger | |
| 499 | ) | |
| 500 | is | |
| 501 | for overridee in overridee_symbols do | |
| 502 | if isa Symbols.Property(overridee) then | |
| 503 | handle_property_overridee( | |
| 504 | overrider_symbol, overridee, logger) | |
| 505 | elif !(isa Symbols.Variable(overridee)) then | |
| 506 | logger.warn(overrider_symbol.location, "hides-inherited", "{overrider_symbol} hides non-property {overridee}", overridee.location, "hidden declaration") | |
| 507 | fi | |
| 508 | od | |
| 509 | si | |
| 510 | ||
| 511 | handle_property_overridee( | |
| 512 | overrider_symbol: Symbols.Property, | |
| 513 | overridee: Symbols.Property, | |
| 514 | logger: Logging.Logger | |
| 515 | ) | |
| 516 | is | |
| 517 | let overridee_type = overridee.type | |
| 518 | let overrider_type = overrider_symbol.type | |
| 519 | ||
| 520 | if !overridee_type? \/ !overrider_type? then | |
| 521 | return | |
| 522 | fi | |
| 523 | ||
| 524 | if !overridee_type.is_assignable_from(overrider_type) then | |
| 525 | // Optionality is not part of the emitted accessor | |
| 526 | // signature, so a property differing from its overridee | |
| 527 | // only in optionality overrides it at run time no matter | |
| 528 | // what is decided here. Widening to optional would let | |
| 529 | // null reach readers typed by the overridee, so it cannot | |
| 530 | // be allowed to stand; genuinely different types really | |
| 531 | // do hide, and keep the warning. | |
| 532 | if !overrider_symbol.is_reflected /\ overrider_type.matches(overridee_type) /\ overrider_type.is_optional /\ !overridee_type.is_optional then | |
| 533 | logger.error(overrider_symbol.location, "cannot override {overridee} with optional type {overrider_type}", overridee.location, "overridden declaration") | |
| 534 | elif overrider_symbol.is_reflected then | |
| 535 | // Imported declarations model optionality more loosely | |
| 536 | // than ghūl does, so a redeclaration that only widens | |
| 537 | // to optional reads here as a type mismatch. It still | |
| 538 | // hides, but there is nothing to report about it. | |
| 539 | return | |
| 540 | elif overridee.is_instance /\ overrider_symbol.is_instance then | |
| 541 | logger.warn(overrider_symbol.location, "override-mismatch-type", "{overrider_symbol} does not override {overridee} due to non-assignable type ({overrider_symbol.type} vs {overridee.type})", overridee.location, "declared here") | |
| 542 | return | |
| 543 | else | |
| 544 | logger.warn(overrider_symbol.location, "hides-inherited", "{overrider_symbol} hides {overridee}", overridee.location, "hidden declaration") | |
| 545 | return | |
| 546 | fi | |
| 547 | elif | |
| 548 | !overrider_symbol.is_reflected /\ | |
| 549 | overridee.is_assignable /\ | |
| 550 | overrider_type.matches(overridee_type) /\ | |
| 551 | !overrider_type.is_optional /\ overridee_type.is_optional | |
| 552 | then | |
| 553 | // Tightening an assignable property to non-optional is | |
| 554 | // unsound in the assign direction: writers typed by the | |
| 555 | // overridee can still store an absent value. | |
| 556 | logger.error(overrider_symbol.location, "cannot override assignable {overridee} with non-optional type {overrider_type}", overridee.location, "overridden declaration") | |
| 557 | fi | |
| 558 | ||
| 559 | let overrides mut = true | |
| 560 | ||
| 561 | if overridee.is_assignable then | |
| 562 | let overridee_assign_is_default_trait = | |
| 563 | overridee.assign_function? /\ overridee.assign_function.is_default_trait_method | |
| 564 | ||
| 565 | if overridee.is_private then | |
| 566 | if !overrider_symbol.is_assignable then | |
| 567 | logger.warn(overrider_symbol.location, "override-missing-assign-accessor", "does not override assign accessor for {overridee}", overridee.location, "assign accessor declared here") | |
| 568 | fi | |
| 569 | else | |
| 570 | if !overrider_symbol.is_assignable /\ !overrider_symbol.is_reflected then | |
| 571 | if overridee_assign_is_default_trait then | |
| 572 | // Inherit the trait's default assign accessor when the | |
| 573 | // overrider only redeclares the read half. | |
| 574 | overrider_symbol.assign_function = overridee.assign_function | |
| 575 | overrider_symbol.is_assignable = true | |
| 576 | ||
| 577 | if let journal = Symbols.INHERITANCE_JOURNAL.current then | |
| 578 | journal.record(Symbols.InheritanceOp.PROPERTY_ASSIGN_INHERITED(overrider_symbol)) | |
| 579 | fi | |
| 580 | else | |
| 581 | logger.error(overrider_symbol.location, "does not override public assign accessor for {overridee}", overridee.location, "assign accessor declared here") | |
| 582 | fi | |
| 583 | elif overrider_symbol.is_private then | |
| 584 | logger.error(overrider_symbol.location, "hides public assign accessor for {overridee}", overridee.location, "assign accessor declared here") | |
| 585 | fi | |
| 586 | fi | |
| 587 | fi | |
| 588 | ||
| 589 | if overrider_symbol.il_name_override? then | |
| 590 | if overridee.il_name_override? /\ overrider_symbol.il_name_override !~ overridee.il_name_override then | |
| 591 | logger.warn(overrider_symbol.location, "override-mismatch-il-name", "{overrider_symbol} does not override {overridee} due to different IL name ({overrider_symbol.il_name_override} vs {overridee.il_name_override})", overridee.location, "declared here") | |
| 592 | overrides = false | |
| 593 | fi | |
| 594 | else | |
| 595 | overrider_symbol.il_name_override = overridee.il_name_override | |
| 596 | ||
| 597 | if overrider_symbol.il_name_override? then | |
| 598 | if let journal = Symbols.INHERITANCE_JOURNAL.current then | |
| 599 | journal.record(Symbols.InheritanceOp.IL_NAME_SET(overrider_symbol)) | |
| 600 | fi | |
| 601 | fi | |
| 602 | fi | |
| 603 | ||
| 604 | if overrides then | |
| 605 | overrider_symbol.add_overridee(overridee) | |
| 606 | overridee.add_overrider(overrider_symbol) | |
| 607 | ||
| 608 | let read_is_default = overridee.read_function? /\ overridee.read_function.is_default_trait_method | |
| 609 | let assign_is_default = overridee.assign_function? /\ overridee.assign_function.is_default_trait_method | |
| 610 | ||
| 611 | if let overridee_owner = cast Symbols.Classy?(overridee.owner) /\ (read_is_default \/ assign_is_default) then | |
| 612 | Symbols.INEFFECTIVE_TRAIT_OVERRIDE_CHECKER() | |
| 613 | .check( | |
| 614 | into, | |
| 615 | overrider_symbol.location, | |
| 616 | overrider_symbol.to_string(), | |
| 617 | overridee, | |
| 618 | overridee.name, | |
| 619 | overridee_owner, | |
| 620 | logger | |
| 621 | ) | |
| 622 | fi | |
| 623 | fi | |
| 624 | si | |
| 625 | ||
| 626 | handle_non_property_overrider( | |
| 627 | overrider_symbol: Symbol, | |
| 628 | overridee_symbols: Iterable[Symbol], | |
| 629 | logger: Logging.Logger | |
| 630 | ) | |
| 631 | is | |
| 632 | if overrider_symbol.can_hide_inherited then | |
| 633 | // we don't care if this particular symbol hides an inherited symbol | |
| 634 | return | |
| 635 | fi | |
| 636 | ||
| 637 | for overridee in overridee_symbols do | |
| 638 | if !(isa Symbols.Variable(overridee)) /\ !overridee.can_hide_inherited then | |
| 639 | logger.info(overrider_symbol.location, "overrider {overrider_symbol.get_type()} hides overridee {overridee.get_type()}") | |
| 640 | logger.warn( | |
| 641 | overrider_symbol.location, | |
| 642 | "hides-inherited", | |
| 643 | "{overrider_symbol} hides (case 3): {overridee_symbols |> join(", ")}", | |
| 644 | overridee.location, | |
| 645 | "hidden declaration") | |
| 646 | fi | |
| 647 | od | |
| 648 | si | |
| 649 | ||
| 650 | handle_multiple_overridee_symbols( | |
| 651 | overridee_symbols: Iterable[Symbol], | |
| 652 | logger: Logging.Logger | |
| 653 | ) | |
| 654 | is | |
| 655 | let symbols = overridee_symbols |> collect_list() | |
| 656 | ||
| 657 | let properties = Collections.LIST[Symbol]() | |
| 658 | let any_non_properties mut = false | |
| 659 | ||
| 660 | for s in symbols do | |
| 661 | if isa Symbols.Property(s) then | |
| 662 | properties.add(s) | |
| 663 | else | |
| 664 | any_non_properties = true | |
| 665 | break | |
| 666 | fi | |
| 667 | od | |
| 668 | ||
| 669 | // Same reasoning as the abstract-method case: an interface | |
| 670 | // hierarchy that redeclares a property covariantly reaches an | |
| 671 | // implementing type once per level, and the most derived | |
| 672 | // declaration subsumes the rest. | |
| 673 | let most_derived = | |
| 674 | if any_non_properties then | |
| 675 | -1 | |
| 676 | else | |
| 677 | MOST_DERIVED_TYPE_SELECTOR().select(properties |> map(s -> Type? => s.type)) | |
| 678 | fi | |
| 679 | ||
| 680 | let inconsistent_types = !any_non_properties /\ most_derived < 0 | |
| 681 | ||
| 682 | let property: Symbol? mut = null | |
| 683 | ||
| 684 | if most_derived >= 0 then | |
| 685 | property = properties[most_derived] | |
| 686 | fi | |
| 687 | ||
| 688 | if any_non_properties then | |
| 689 | logger.error( | |
| 690 | into.location, | |
| 691 | "cannot inherit multiple symbols with the same name { | |
| 692 | symbols |> | |
| 693 | map(s => s.to_string()) |> | |
| 694 | sort() |> | |
| 695 | join() | |
| 696 | }" | |
| 697 | ) | |
| 698 | elif inconsistent_types then | |
| 699 | logger.error( | |
| 700 | into.location, | |
| 701 | "cannot inherit multiple properties with the same name but different types { | |
| 702 | symbols |> | |
| 703 | map(s => s.to_string()) |> | |
| 704 | sort() |> | |
| 705 | join() | |
| 706 | }" | |
| 707 | ) | |
| 708 | elif property? then | |
| 709 | into.add_member(property) | |
| 710 | else | |
| 711 | logger.error( | |
| 712 | into.location, | |
| 713 | "did nothing with multiple parent symbols { | |
| 714 | symbols |> | |
| 715 | map(s => s.to_string()) |> | |
| 716 | sort() |> | |
| 717 | join() | |
| 718 | }" | |
| 719 | ) | |
| 720 | fi | |
| 721 | si | |
| 722 | ||
| 723 | get_overriders_map_for(overridee_name: string) -> METHOD_OVERRIDE_MAP is | |
| 724 | let symbol = into.find_direct(overridee_name) | |
| 725 | ||
| 726 | if !symbol? then | |
| 727 | return METHOD_OVERRIDE_MAP.empty | |
| 728 | fi | |
| 729 | ||
| 730 | let result = METHOD_OVERRIDE_MAP(overridee_name) | |
| 731 | ||
| 732 | if isa FUNCTION_GROUP(symbol) then | |
| 733 | for f in symbol.functions do | |
| 734 | result.add(f) | |
| 735 | od | |
| 736 | elif !symbol.is_type_variable then | |
| 737 | result.add(symbol) | |
| 738 | fi | |
| 739 | ||
| 740 | return result | |
| 741 | si | |
| 742 | si | |
| 743 | si |