Appearance
| 1 | namespace Syntax.Process is | |
| 2 | use System.Exception | |
| 3 | ||
| 4 | use Ghul.Pipes | |
| 5 | ||
| 6 | use Logging | |
| 7 | use Trees | |
| 8 | ||
| 9 | use Semantic.Types.Type | |
| 10 | ||
| 11 | use Function = Semantic.Symbols.Function | |
| 12 | use Symbol = Semantic.Symbols.Symbol | |
| 13 | ||
| 14 | // Value and expression walks: references, calls, operators, identifiers, members, indexing | |
| 15 | // and generic applications. | |
| 16 | partial INFER_STORE_FREE is | |
| 17 | // `x ref` hands the callee the address of a storage location | |
| 18 | // rather than a value, and the callee may write through it. | |
| 19 | // What the callee itself does is bounded by the enclosing | |
| 20 | // call's own edges, with one exception that decides this | |
| 21 | // classification: several of the imports trusted store-free | |
| 22 | // write a by-ref argument by contract — `try_get_value` is the | |
| 23 | // everyday one — so a write through the address is not always | |
| 24 | // covered by a callee edge. The operand therefore has to carry | |
| 25 | // it. The address of a local variable or parameter is | |
| 26 | // callee-private, exactly as assigning one is; the address of a | |
| 27 | // field, a property or an element is a possible heap store. | |
| 28 | // | |
| 29 | // The node's own `writes_target` flag says which direction the | |
| 30 | // matched parameter takes, and is deliberately not consulted: | |
| 31 | // it is set during call resolution, which runs after this pass, | |
| 32 | // so every REFERENCE reaching here still reads false. | |
| 33 | // | |
| 34 | // The operand is walked as a child, so its own reads are | |
| 35 | // classified independently of this. | |
| 36 | visit(reference: Expressions.REFERENCE) is | |
| 37 | if !_current? then | |
| 38 | return | |
| 39 | fi | |
| 40 | ||
| 41 | if !_is_local_target(reference.left) then | |
| 42 | _disqualify() | |
| 43 | fi | |
| 44 | si | |
| 45 | ||
| 46 | // Record, for the study, which member symbol a store targets. | |
| 47 | // Mirrors the classification below without affecting it: a | |
| 48 | // local target records nothing, a resolvable member records | |
| 49 | // that symbol, anything else marks the writes unboundable. | |
| 50 | _study_note_store(target: Trees.Expressions.Expression?) is | |
| 51 | if !_current_record? then | |
| 52 | return | |
| 53 | fi | |
| 54 | ||
| 55 | if !target? then | |
| 56 | _current_record.writes_unbounded = true | |
| 57 | return | |
| 58 | fi | |
| 59 | ||
| 60 | if isa Trees.Expressions.IDENTIFIER(target) then | |
| 61 | let symbol = try_find((cast Trees.Expressions.IDENTIFIER(target)).identifier) | |
| 62 | ||
| 63 | if | |
| 64 | symbol? /\ | |
| 65 | (isa Semantic.Symbols.LOCAL_VARIABLE(symbol) \/ isa Semantic.Symbols.LOCAL_ARGUMENT(symbol)) | |
| 66 | then | |
| 67 | // A store to a local the current body captured | |
| 68 | // from an enclosing scope is not callee-private: | |
| 69 | // the two share one heap cell, so the declaring | |
| 70 | // scope sees the write. It enters the write and | |
| 71 | // nulling sets under the local's own symbol, so a | |
| 72 | // caller this body is absorbed into carries it. | |
| 73 | if _is_captured_local_store(symbol) then | |
| 74 | _study_note_nulling(false) | |
| 75 | _study_note_nulling_member(symbol, false) | |
| 76 | _study_add_write(symbol) | |
| 77 | fi | |
| 78 | ||
| 79 | return | |
| 80 | fi | |
| 81 | ||
| 82 | _study_note_nulling(symbol? /\ symbol.is_instance) | |
| 83 | _study_note_nulling_member(symbol, symbol? /\ symbol.is_instance) | |
| 84 | _study_add_write(symbol) | |
| 85 | return | |
| 86 | fi | |
| 87 | ||
| 88 | if isa Trees.Expressions.MEMBER(target) then | |
| 89 | let member = cast Trees.Expressions.MEMBER(target) | |
| 90 | ||
| 91 | if isa Trees.Expressions.SELF(member.left) then | |
| 92 | let context = current_instance_context | |
| 93 | ||
| 94 | if context? then | |
| 95 | _study_note_nulling(true) | |
| 96 | _study_note_nulling_member(context.find_member(member.identifier.name), true) | |
| 97 | _study_add_write(context.find_member(member.identifier.name)) | |
| 98 | return | |
| 99 | fi | |
| 100 | fi | |
| 101 | ||
| 102 | let left_type = _typer.try_type(member.left) | |
| 103 | ||
| 104 | if !left_type? then | |
| 105 | _study_note_nulling(false) | |
| 106 | _study_note_nulling_member(null, false) | |
| 107 | _study_unbounded_store("store-receiver-untyped") | |
| 108 | return | |
| 109 | fi | |
| 110 | ||
| 111 | let member_symbol = left_type.find_member(member.identifier.name) | |
| 112 | ||
| 113 | if !member_symbol? then | |
| 114 | _study_note_nulling(false) | |
| 115 | _study_note_nulling_member(null, false) | |
| 116 | _study_unbounded_store("store-member-not-found") | |
| 117 | return | |
| 118 | fi | |
| 119 | ||
| 120 | _study_note_nulling(false) | |
| 121 | _study_note_nulling_member(member_symbol, false) | |
| 122 | _study_add_write(member_symbol) | |
| 123 | return | |
| 124 | fi | |
| 125 | ||
| 126 | if isa Trees.Expressions.INDEX(target) then | |
| 127 | // an element store: cannot change what any field holds, | |
| 128 | // so it is recorded apart from member writes - the | |
| 129 | // element-rescue measurement keys on the distinction | |
| 130 | _current_record.writes_elements = true | |
| 131 | return | |
| 132 | fi | |
| 133 | ||
| 134 | // `xs[i] = v` parses as an ambiguous expression; once | |
| 135 | // compile-expressions has settled which shape it is, an | |
| 136 | // index store is an element store like any other | |
| 137 | if let ambiguous: Trees.Expressions.AMBIGUOUS_EXPRESSION = target then | |
| 138 | if ambiguous.result == Trees.Expressions.AmbiguousExpressionResult.INDEX then | |
| 139 | _current_record.writes_elements = true | |
| 140 | return | |
| 141 | fi | |
| 142 | ||
| 143 | _study_note_nulling(false) | |
| 144 | _study_note_nulling_member(null, false) | |
| 145 | _study_unbounded_store("store-ambiguous-unresolved") | |
| 146 | return | |
| 147 | fi | |
| 148 | ||
| 149 | // a target shape the walk does not model | |
| 150 | _study_note_nulling(false) | |
| 151 | _study_note_nulling_member(null, false) | |
| 152 | _study_unbounded_store("store-target-shape:{target.get_type().name}") | |
| 153 | si | |
| 154 | ||
| 155 | // Mark the current record's write set unboundable, naming why, | |
| 156 | // so the blame table can split the catch-all | |
| 157 | // "write-target-unresolved" bucket by cause. | |
| 158 | _study_unbounded_store(reason: string) is | |
| 159 | if !_current_record? then | |
| 160 | return | |
| 161 | fi | |
| 162 | ||
| 163 | _current_record.writes_unbounded = true | |
| 164 | ||
| 165 | if _current_record.unbounded_reason =~ "" then | |
| 166 | _current_record.unbounded_reason = reason | |
| 167 | fi | |
| 168 | si | |
| 169 | ||
| 170 | _study_add_write(symbol: Symbol?) is | |
| 171 | if !_current_record? then | |
| 172 | return | |
| 173 | fi | |
| 174 | ||
| 175 | if !symbol? then | |
| 176 | _current_record.writes_unbounded = true | |
| 177 | return | |
| 178 | fi | |
| 179 | ||
| 180 | _current_record.writes.add(symbol.root_specialized_from) | |
| 181 | si | |
| 182 | ||
| 183 | // ==== calls ==== | |
| 184 | ||
| 185 | visit(call: Expressions.CALL) is | |
| 186 | if !_current? then | |
| 187 | return | |
| 188 | fi | |
| 189 | ||
| 190 | // Study-only: after compile-expressions the call carries the | |
| 191 | // value it compiled to, which names the callee directly | |
| 192 | // whatever shape the target expression has. | |
| 193 | if _resolved_mode then | |
| 194 | let value = call.value | |
| 195 | ||
| 196 | if value? /\ _classify_resolved_value(value) then | |
| 197 | return | |
| 198 | fi | |
| 199 | fi | |
| 200 | ||
| 201 | _add_call_target_edges(call.function) | |
| 202 | si | |
| 203 | ||
| 204 | // A value slot whose declared type is a pure function type: | |
| 205 | // invoking the held value is trusted store-free, whatever it | |
| 206 | // turns out to be — the pure-typed slot only admits pure | |
| 207 | // values. Parameters and fields qualify; a property is excluded | |
| 208 | // because reading it runs its getter. A local variable is | |
| 209 | // excluded too: its `type` is filled by compile-expressions, | |
| 210 | // which runs after this pass, so reading it here would make the | |
| 211 | // classification depend on whether that later pass has run — it | |
| 212 | // has in an analysis-mode refresh, it has not in a batch build. | |
| 213 | _is_pure_function_valued(symbol: Semantic.Symbols.Symbol?) -> bool => | |
| 214 | symbol? /\ | |
| 215 | isa Semantic.Symbols.Variable(symbol) /\ | |
| 216 | (_resolved_mode \/ !isa Semantic.Symbols.LOCAL_VARIABLE(symbol)) /\ | |
| 217 | symbol.type? /\ symbol.type.is_pure_function | |
| 218 | ||
| 219 | // A synthesized `=~` or `get_hash_code`. The body stores | |
| 220 | // nothing of its own - it reads members and compares them - so | |
| 221 | // what it can do is exactly what the comparisons it reaches | |
| 222 | // do, and the lowering recorded those as it chose them. | |
| 223 | // | |
| 224 | // Before compile-expressions there is nothing to read: the | |
| 225 | // members have no types yet, so which comparison each takes is | |
| 226 | // undecided and the body cannot be classified. | |
| 227 | visit(memberwise: Trees.Expressions.MEMBERWISE_EQUALS) is | |
| 228 | _add_memberwise_edges(memberwise.called_functions, memberwise.value?) | |
| 229 | si | |
| 230 | ||
| 231 | visit(memberwise: Trees.Expressions.MEMBERWISE_HASH) is | |
| 232 | _add_memberwise_edges(memberwise.called_functions, memberwise.value?) | |
| 233 | si | |
| 234 | ||
| 235 | _add_memberwise_edges( | |
| 236 | called: Collections.LIST[Semantic.Symbols.Function], | |
| 237 | lowered: bool | |
| 238 | ) is | |
| 239 | // Before compile-expressions the members have no types, so | |
| 240 | // which comparison each takes is undecided and there is | |
| 241 | // nothing to record. The resolved walk that follows is | |
| 242 | // what settles the body; nothing between the two reads a | |
| 243 | // synthesized operator's bit. | |
| 244 | if !lowered then | |
| 245 | return | |
| 246 | fi | |
| 247 | ||
| 248 | for function in called do | |
| 249 | _add_callee(function) | |
| 250 | od | |
| 251 | si | |
| 252 | ||
| 253 | _add_call_target_edges(target: Trees.Expressions.Expression?) is | |
| 254 | if !target? then | |
| 255 | _disqualify_because("call-target-null") | |
| 256 | return | |
| 257 | fi | |
| 258 | ||
| 259 | if isa Trees.Expressions.IDENTIFIER(target) then | |
| 260 | let identifier = (cast Trees.Expressions.IDENTIFIER(target)).identifier | |
| 261 | ||
| 262 | let symbol = try_find(identifier) | |
| 263 | ||
| 264 | if _is_pure_function_valued(symbol) then | |
| 265 | return | |
| 266 | fi | |
| 267 | ||
| 268 | _add_callee_edges(symbol) | |
| 269 | return | |
| 270 | fi | |
| 271 | ||
| 272 | if isa Trees.Expressions.MEMBER(target) then | |
| 273 | let member = cast Trees.Expressions.MEMBER(target) | |
| 274 | ||
| 275 | if _is_constructor_chain(member) then | |
| 276 | // `super.init(…)` or `self.init(…)` runs on the | |
| 277 | // object this constructor is itself being run on, | |
| 278 | // so it is bounded the same way a construction is — | |
| 279 | // and writes that receiver's own state, so it | |
| 280 | // disqualifies the strict bit just as writing a | |
| 281 | // field directly does | |
| 282 | _disqualify_strict_only() | |
| 283 | ||
| 284 | let receiver_type = _typer.try_type(member.left) | |
| 285 | ||
| 286 | if !receiver_type? then | |
| 287 | _disqualify_because("ctor-chain-receiver-untyped") | |
| 288 | return | |
| 289 | fi | |
| 290 | ||
| 291 | _add_construction_edges(receiver_type.find_member("init")) | |
| 292 | return | |
| 293 | fi | |
| 294 | ||
| 295 | let as_identifier = member.try_copy_as_identifer() | |
| 296 | ||
| 297 | if as_identifier? then | |
| 298 | let symbol = try_find(as_identifier) | |
| 299 | ||
| 300 | if symbol? then | |
| 301 | if _is_pure_function_valued(symbol) then | |
| 302 | return | |
| 303 | fi | |
| 304 | ||
| 305 | _add_callee_edges(symbol) | |
| 306 | return | |
| 307 | fi | |
| 308 | fi | |
| 309 | ||
| 310 | let left_type = _typer.try_type(member.left) | |
| 311 | ||
| 312 | if !left_type? then | |
| 313 | _disqualify_because("call-receiver-untyped") | |
| 314 | return | |
| 315 | fi | |
| 316 | ||
| 317 | let member_symbol = left_type.find_member(member.identifier.name) | |
| 318 | ||
| 319 | if member_symbol? /\ _is_pure_function_valued(member_symbol) /\ member_symbol.is_field then | |
| 320 | return | |
| 321 | fi | |
| 322 | ||
| 323 | _add_callee_edges(member_symbol) | |
| 324 | return | |
| 325 | fi | |
| 326 | ||
| 327 | if isa Trees.Expressions.RECURSE(target) then | |
| 328 | _add_callee(_current_function) | |
| 329 | return | |
| 330 | fi | |
| 331 | ||
| 332 | _disqualify_because("call-target-shape") | |
| 333 | si | |
| 334 | ||
| 335 | // ==== operators ==== | |
| 336 | ||
| 337 | visit(binary: Expressions.BINARY) is | |
| 338 | if !_current? then | |
| 339 | return | |
| 340 | fi | |
| 341 | ||
| 342 | _add_operator_edges(binary.operation, binary.left, binary.right) | |
| 343 | si | |
| 344 | ||
| 345 | visit(unary: Expressions.UNARY) is | |
| 346 | if !_current? then | |
| 347 | return | |
| 348 | fi | |
| 349 | ||
| 350 | _add_operator_edges(unary.operation, unary.right, null) | |
| 351 | si | |
| 352 | ||
| 353 | _add_operator_edges( | |
| 354 | operation: Identifiers.Identifier?, | |
| 355 | left: Trees.Expressions.Expression?, | |
| 356 | right: Trees.Expressions.Expression? | |
| 357 | ) is | |
| 358 | if !operation? then | |
| 359 | _disqualify_because("operator-unresolved") | |
| 360 | return | |
| 361 | fi | |
| 362 | ||
| 363 | // free operator functions visible in scope: the innate | |
| 364 | // operators and user-defined operators share one group | |
| 365 | let group = find(operation.name) | |
| 366 | ||
| 367 | if group? then | |
| 368 | _add_callee_edges(group) | |
| 369 | fi | |
| 370 | ||
| 371 | // `==` has a single compiler-generated implementation: | |
| 372 | // `==` and `!=` both carry the operation name `==` (the | |
| 373 | // parser rewrites `!=`), and neither can be overloaded or | |
| 374 | // overridden as a member. There is never a member operator | |
| 375 | // to bound, so the member lookup — which otherwise | |
| 376 | // disqualifies the function whenever an operand's type is | |
| 377 | // not trivially derivable — is skipped. | |
| 378 | // | |
| 379 | // `=~` and `<>` are skipped for a different reason: every | |
| 380 | // declaration is store-free by construction, because | |
| 381 | // CHECK_PURE_OVERRIDES rejects any that is not declared | |
| 382 | // pure or provably store-free. A member lookup could only | |
| 383 | // find implementations already known safe, and would | |
| 384 | // disqualify on operands whose type is not derivable here | |
| 385 | // — a lambda parameter, or a bare type parameter compared | |
| 386 | // through the runtime's comparer, where the comparison can | |
| 387 | // dispatch to any implementation at all. Reflected forms | |
| 388 | // reach Equals/CompareTo, which the runtime contract | |
| 389 | // treats as side-effect-free, so they are trusted the same | |
| 390 | // way. | |
| 391 | if operation.name =~ "==" \/ operation.name =~ "=~" \/ operation.name =~ "<>" then | |
| 392 | return | |
| 393 | fi | |
| 394 | ||
| 395 | // operator members can only be bounded when the operand | |
| 396 | // types are known | |
| 397 | _add_member_operator_edges(operation.name, left) | |
| 398 | ||
| 399 | if right? then | |
| 400 | _add_member_operator_edges(operation.name, right) | |
| 401 | fi | |
| 402 | si | |
| 403 | ||
| 404 | _add_member_operator_edges(name: string, operand: Trees.Expressions.Expression?) is | |
| 405 | let operand_type = _typer.try_type(operand) | |
| 406 | ||
| 407 | if !operand_type? then | |
| 408 | // The operand's type is not trivially derivable, so a | |
| 409 | // member operator on it cannot be bounded here — the | |
| 410 | // same position a call on an untypable receiver is | |
| 411 | // in, and answered the same way. The free and innate | |
| 412 | // operators are already bounded through the operator | |
| 413 | // group above. | |
| 414 | _disqualify_because("member-operator-unresolved") | |
| 415 | ||
| 416 | return | |
| 417 | fi | |
| 418 | ||
| 419 | let member_symbol = operand_type.find_member(name) | |
| 420 | ||
| 421 | // A member hidden from operator resolution is never what an | |
| 422 | // operator expression calls, so following its call edge would | |
| 423 | // bound the enclosing function by a method it cannot invoke. | |
| 424 | // | |
| 425 | // Soundness rests on this matching `COMPILE_OPERATORS`, which | |
| 426 | // discards the same members when it gathers candidates. Both | |
| 427 | // ask `HIDDEN_OPERATOR_MEMBERS`, so the two cannot drift: the | |
| 428 | // operand ends up bounded by the operator that really runs, | |
| 429 | // which for these types is an innate already classified by | |
| 430 | // `STORE_FREE_INNATES`. | |
| 431 | // | |
| 432 | // A group is skipped only when every function in it is hidden, | |
| 433 | // so a same-named user overload is still bounded as before. | |
| 434 | if member_symbol? /\ !HIDDEN_OPERATOR_MEMBERS.is_hidden(member_symbol) then | |
| 435 | _add_callee_edges(member_symbol) | |
| 436 | fi | |
| 437 | si | |
| 438 | ||
| 439 | // ==== reads ==== | |
| 440 | ||
| 441 | visit(identifier: Expressions.IDENTIFIER) is | |
| 442 | if !_current? then | |
| 443 | return | |
| 444 | fi | |
| 445 | ||
| 446 | // an unresolvable bare name is either an error compile- | |
| 447 | // expressions will report or a contextual load (a unit | |
| 448 | // variant); neither can store | |
| 449 | _classify_member_read(try_find(identifier.identifier)) | |
| 450 | si | |
| 451 | ||
| 452 | visit(member: Expressions.MEMBER) is | |
| 453 | if !_current? then | |
| 454 | return | |
| 455 | fi | |
| 456 | ||
| 457 | let as_identifier = member.try_copy_as_identifer() | |
| 458 | ||
| 459 | if as_identifier? then | |
| 460 | let symbol = try_find(as_identifier) | |
| 461 | ||
| 462 | if symbol? then | |
| 463 | _classify_member_read(symbol) | |
| 464 | return | |
| 465 | fi | |
| 466 | fi | |
| 467 | ||
| 468 | let left_type = _typer.try_type(member.left) | |
| 469 | ||
| 470 | if left_type? then | |
| 471 | let member_symbol = left_type.find_member(member.identifier.name) | |
| 472 | ||
| 473 | if member_symbol? then | |
| 474 | _classify_member_read(member_symbol) | |
| 475 | return | |
| 476 | fi | |
| 477 | fi | |
| 478 | ||
| 479 | // untyped receiver: if this member turns out to be a | |
| 480 | // property, its getter could run arbitrary code | |
| 481 | _disqualify_because("member-receiver-untyped") | |
| 482 | si | |
| 483 | ||
| 484 | visit(index: Expressions.INDEX) is | |
| 485 | if !_current? then | |
| 486 | return | |
| 487 | fi | |
| 488 | ||
| 489 | let left_type = _typer.try_type(index.left) | |
| 490 | ||
| 491 | if !left_type? then | |
| 492 | _disqualify_because("index-receiver-untyped") | |
| 493 | return | |
| 494 | fi | |
| 495 | ||
| 496 | if isa Semantic.Types.ARRAY(left_type) then | |
| 497 | // array element read; element stores only occur as | |
| 498 | // assignment targets, which are classified separately | |
| 499 | return | |
| 500 | fi | |
| 501 | ||
| 502 | // an indexer read runs the receiver type's get_Item — | |
| 503 | // bound it like any other member call | |
| 504 | _add_callee_edges(left_type.find_member(Semantic.Symbols.INDEXER_NAMES.read)) | |
| 505 | si | |
| 506 | ||
| 507 | visit(recurse: Expressions.RECURSE) is | |
| 508 | if !_current? then | |
| 509 | return | |
| 510 | fi | |
| 511 | ||
| 512 | _add_callee(_current_function) | |
| 513 | si | |
| 514 | ||
| 515 | // ==== type application ==== | |
| 516 | ||
| 517 | // `a.b[X]` where `X` reads as both a type argument and an index | |
| 518 | // expression. Resolve-type-expressions settles the index | |
| 519 | // reading when the type argument fails to resolve, and then the | |
| 520 | // INDEX node it built is walked and classified in its own | |
| 521 | // right, leaving nothing to do here. | |
| 522 | visit(ambiguous: Expressions.AMBIGUOUS_EXPRESSION) is | |
| 523 | if !_current? then | |
| 524 | return | |
| 525 | fi | |
| 526 | ||
| 527 | if ambiguous.result == Expressions.AmbiguousExpressionResult.INDEX then | |
| 528 | return | |
| 529 | fi | |
| 530 | ||
| 531 | _classify_type_application(ambiguous.result, ambiguous.left, ambiguous.identifier) | |
| 532 | si | |
| 533 | ||
| 534 | // `a.b[X]` where `X` can only be a type argument. Applying type | |
| 535 | // arguments to a generic type or member is a read, so it | |
| 536 | // classifies exactly as the same member read without them | |
| 537 | // would; a call spelt this way is wrapped in a CALL node, which | |
| 538 | // is classified separately and on its own terms. | |
| 539 | visit(generic_application: Expressions.GENERIC_APPLICATION) is | |
| 540 | if !_current? then | |
| 541 | return | |
| 542 | fi | |
| 543 | ||
| 544 | _classify_type_application( | |
| 545 | generic_application.result, | |
| 546 | generic_application.left, | |
| 547 | generic_application.identifier | |
| 548 | ) | |
| 549 | si | |
| 550 | ||
| 551 | _classify_type_application( | |
| 552 | result: Expressions.AmbiguousExpressionResult, | |
| 553 | left: Trees.Expressions.Expression?, | |
| 554 | identifier: Identifiers.Identifier | |
| 555 | ) is | |
| 556 | // Both node kinds walk their receiver only once a later | |
| 557 | // pass has settled what the application applies to, which | |
| 558 | // for every node reaching this pass means not yet. So the | |
| 559 | // receiver has to be walked from here — otherwise a call or | |
| 560 | // an index sitting in it would never be classified at all. | |
| 561 | if result == Expressions.AmbiguousExpressionResult.UNKNOWN /\ left? then | |
| 562 | left.walk(self) | |
| 563 | fi | |
| 564 | ||
| 565 | if !left? then | |
| 566 | _classify_member_read(try_find(identifier)) | |
| 567 | return | |
| 568 | fi | |
| 569 | ||
| 570 | // a receiver that is itself a name resolves as one | |
| 571 | // qualified name — the route a namespace-qualified type or | |
| 572 | // a union's variant arrives by. The joined name exists only | |
| 573 | // for this lookup, so its spans are the identifier's own. | |
| 574 | let left_as_identifier = left.try_copy_as_identifer() | |
| 575 | ||
| 576 | if left_as_identifier? then | |
| 577 | let symbol = | |
| 578 | try_find( | |
| 579 | Identifiers.QUALIFIED( | |
| 580 | identifier.location, | |
| 581 | left_as_identifier, | |
| 582 | identifier.name, | |
| 583 | identifier.location, | |
| 584 | identifier.right_location | |
| 585 | ) | |
| 586 | ) | |
| 587 | ||
| 588 | if symbol? then | |
| 589 | _classify_member_read(symbol) | |
| 590 | return | |
| 591 | fi | |
| 592 | fi | |
| 593 | ||
| 594 | let left_type = _typer.try_type(left) | |
| 595 | ||
| 596 | if !left_type? then | |
| 597 | _disqualify() | |
| 598 | return | |
| 599 | fi | |
| 600 | ||
| 601 | let member_symbol = left_type.find_member(identifier.name) | |
| 602 | ||
| 603 | if !member_symbol? then | |
| 604 | // untyped or unresolvable member: if it turns out to be | |
| 605 | // a property, its getter could run arbitrary code | |
| 606 | _disqualify() | |
| 607 | return | |
| 608 | fi | |
| 609 | ||
| 610 | _classify_member_read(member_symbol) | |
| 611 | si | |
| 612 | ||
| 613 | si | |
| 614 | si |