| 1 | use indexmap::{IndexMap, IndexSet}; |
| 2 | use react_compiler_ast::scope::BindingId; |
| 3 | use react_compiler_ast::scope::ImportBindingKind; |
| 4 | use react_compiler_ast::scope::ScopeId; |
| 5 | use react_compiler_ast::scope::ScopeInfo; |
| 6 | use react_compiler_diagnostics::CompilerDiagnostic; |
| 7 | use react_compiler_diagnostics::CompilerDiagnosticDetail; |
| 8 | use react_compiler_diagnostics::CompilerError; |
| 9 | use react_compiler_diagnostics::CompilerErrorDetail; |
| 10 | use react_compiler_diagnostics::ErrorCategory; |
| 11 | use react_compiler_hir::environment::Environment; |
| 12 | use react_compiler_hir::visitors::each_terminal_successor; |
| 13 | use react_compiler_hir::visitors::terminal_fallthrough; |
| 14 | use react_compiler_hir::*; |
| 15 | use rustc_hash::FxBuildHasher; |
| 16 | |
| 17 | use crate::identifier_loc_index::IdentifierLocIndex; |
| 18 | |
| 19 | // --------------------------------------------------------------------------- |
| 20 | // Reserved word check (matches TS isReservedWord) |
| 21 | // --------------------------------------------------------------------------- |
| 22 | |
| 23 | pub(crate) fn is_always_reserved_word(s: &str) -> bool { |
| 24 | matches!( |
| 25 | s, |
| 26 | "break" |
| 27 | | "case" |
| 28 | | "catch" |
| 29 | | "continue" |
| 30 | | "debugger" |
| 31 | | "default" |
| 32 | | "do" |
| 33 | | "else" |
| 34 | | "finally" |
| 35 | | "for" |
| 36 | | "function" |
| 37 | | "if" |
| 38 | | "in" |
| 39 | | "instanceof" |
| 40 | | "new" |
| 41 | | "return" |
| 42 | | "switch" |
| 43 | | "this" |
| 44 | | "throw" |
| 45 | | "try" |
| 46 | | "typeof" |
| 47 | | "var" |
| 48 | | "void" |
| 49 | | "while" |
| 50 | | "with" |
| 51 | | "class" |
| 52 | | "const" |
| 53 | | "enum" |
| 54 | | "export" |
| 55 | | "extends" |
| 56 | | "import" |
| 57 | | "super" |
| 58 | | "null" |
| 59 | | "true" |
| 60 | | "false" |
| 61 | | "delete" |
| 62 | ) |
| 63 | } |
| 64 | |
| 65 | pub(crate) fn reserved_identifier_diagnostic(name: &str) -> CompilerDiagnostic { |
| 66 | CompilerDiagnostic::new( |
| 67 | ErrorCategory::Syntax, |
| 68 | "Expected a non-reserved identifier name", |
| 69 | Some(format!( |
| 70 | "`{}` is a reserved word in JavaScript and cannot be used as an identifier name", |
| 71 | name |
| 72 | )), |
| 73 | ) |
| 74 | .with_detail(CompilerDiagnosticDetail::Error { |
| 75 | loc: None, // GeneratedSource in TS |
| 76 | message: Some("reserved word".to_string()), |
| 77 | identifier_name: None, |
| 78 | }) |
| 79 | } |
| 80 | |
| 81 | // --------------------------------------------------------------------------- |
| 82 | // Scope types for tracking break/continue targets |
| 83 | // --------------------------------------------------------------------------- |
| 84 | |
| 85 | enum Scope { |
| 86 | Loop { |
| 87 | label: Option<String>, |
| 88 | continue_block: BlockId, |
| 89 | break_block: BlockId, |
| 90 | }, |
| 91 | Label { |
| 92 | label: String, |
| 93 | break_block: BlockId, |
| 94 | }, |
| 95 | Switch { |
| 96 | label: Option<String>, |
| 97 | break_block: BlockId, |
| 98 | }, |
| 99 | } |
| 100 | |
| 101 | impl Scope { |
| 102 | fn label(&self) -> Option<&str> { |
| 103 | match self { |
| 104 | Scope::Loop { label, .. } => label.as_deref(), |
| 105 | Scope::Label { label, .. } => Some(label.as_str()), |
| 106 | Scope::Switch { label, .. } => label.as_deref(), |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | fn break_block(&self) -> BlockId { |
| 111 | match self { |
| 112 | Scope::Loop { break_block, .. } => *break_block, |
| 113 | Scope::Label { break_block, .. } => *break_block, |
| 114 | Scope::Switch { break_block, .. } => *break_block, |
| 115 | } |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | // --------------------------------------------------------------------------- |
| 120 | // WipBlock: a block under construction that does not yet have a terminal |
| 121 | // --------------------------------------------------------------------------- |
| 122 | |
| 123 | pub struct WipBlock { |
| 124 | pub id: BlockId, |
| 125 | pub instructions: Vec<InstructionId>, |
| 126 | pub kind: BlockKind, |
| 127 | } |
| 128 | |
| 129 | fn new_block(id: BlockId, kind: BlockKind) -> WipBlock { |
| 130 | WipBlock { |
| 131 | id, |
| 132 | kind, |
| 133 | instructions: Vec::new(), |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | // --------------------------------------------------------------------------- |
| 138 | // HirBuilder: helper struct for constructing a CFG |
| 139 | // --------------------------------------------------------------------------- |
| 140 | |
| 141 | pub struct HirBuilder<'a> { |
| 142 | completed: IndexMap<BlockId, BasicBlock, FxBuildHasher>, |
| 143 | current: WipBlock, |
| 144 | entry: BlockId, |
| 145 | scopes: Vec<Scope>, |
| 146 | /// Context identifiers: variables captured from an outer scope. |
| 147 | /// Maps the outer scope's BindingId to the source location where it was referenced. |
| 148 | context: IndexMap<BindingId, Option<SourceLocation>, FxBuildHasher>, |
| 149 | /// Resolved bindings: maps a BindingId to the HIR IdentifierId created for it. |
| 150 | bindings: IndexMap<BindingId, IdentifierId, FxBuildHasher>, |
| 151 | /// Names already used by bindings, for collision avoidance. |
| 152 | /// Maps name string -> how many times it has been used (for appending _0, _1, ...). |
| 153 | used_names: IndexMap<String, BindingId, FxBuildHasher>, |
| 154 | env: &'a mut Environment, |
| 155 | scope_info: &'a ScopeInfo, |
| 156 | exception_handler_stack: Vec<BlockId>, |
| 157 | /// Flat instruction table being built up. |
| 158 | instruction_table: Vec<Instruction>, |
| 159 | /// Traversal context: counts the number of `fbt` tag parents |
| 160 | /// of the current babel node. |
| 161 | pub fbt_depth: u32, |
| 162 | /// The scope of the function being compiled (for context identifier checks). |
| 163 | function_scope: ScopeId, |
| 164 | /// The scope of the outermost component/hook function (for gather_captured_context). |
| 165 | component_scope: ScopeId, |
| 166 | /// Set of BindingIds for variables declared in scopes between component_scope |
| 167 | /// and any inner function scope, that are referenced from an inner function scope. |
| 168 | /// These need StoreContext/LoadContext instead of StoreLocal/LoadLocal. |
| 169 | context_identifiers: rustc_hash::FxHashSet<BindingId>, |
| 170 | /// Set of ScopeIds that have been matched to synthetic blocks/functions. |
| 171 | /// Prevents the same scope from being reused for different synthetic nodes. |
| 172 | claimed_synthetic_scopes: rustc_hash::FxHashSet<ScopeId>, |
| 173 | /// Index mapping identifier byte offsets to source locations and JSX status. |
| 174 | identifier_locs: &'a IdentifierLocIndex, |
| 175 | } |
| 176 | |
| 177 | impl<'a> HirBuilder<'a> { |
| 178 | // ----------------------------------------------------------------------- |
| 179 | // M2: Core methods |
| 180 | // ----------------------------------------------------------------------- |
| 181 | |
| 182 | /// Create a new HirBuilder. |
| 183 | /// |
| 184 | /// - `env`: the shared environment (counters, arenas, error accumulator) |
| 185 | /// - `scope_info`: the scope information from the AST |
| 186 | /// - `function_scope`: the ScopeId of the function being compiled |
| 187 | /// - `bindings`: optional pre-existing bindings (e.g., from a parent function) |
| 188 | /// - `context`: optional pre-existing captured context map |
| 189 | /// - `entry_block_kind`: the kind of the entry block (defaults to `Block`) |
| 190 | pub fn new( |
| 191 | env: &'a mut Environment, |
| 192 | scope_info: &'a ScopeInfo, |
| 193 | function_scope: ScopeId, |
| 194 | component_scope: ScopeId, |
| 195 | context_identifiers: rustc_hash::FxHashSet<BindingId>, |
| 196 | bindings: Option<IndexMap<BindingId, IdentifierId, FxBuildHasher>>, |
| 197 | context: Option<IndexMap<BindingId, Option<SourceLocation>, FxBuildHasher>>, |
| 198 | entry_block_kind: Option<BlockKind>, |
| 199 | used_names: Option<IndexMap<String, BindingId, FxBuildHasher>>, |
| 200 | identifier_locs: &'a IdentifierLocIndex, |
| 201 | ) -> Self { |
| 202 | let entry = env.next_block_id(); |
| 203 | let kind = entry_block_kind.unwrap_or(BlockKind::Block); |
| 204 | HirBuilder { |
| 205 | completed: IndexMap::default(), |
| 206 | current: new_block(entry, kind), |
| 207 | entry, |
| 208 | scopes: Vec::new(), |
| 209 | context: context.unwrap_or_default(), |
| 210 | bindings: bindings.unwrap_or_default(), |
| 211 | used_names: used_names.unwrap_or_default(), |
| 212 | env, |
| 213 | scope_info, |
| 214 | exception_handler_stack: Vec::new(), |
| 215 | instruction_table: Vec::new(), |
| 216 | fbt_depth: 0, |
| 217 | function_scope, |
| 218 | component_scope, |
| 219 | context_identifiers, |
| 220 | claimed_synthetic_scopes: rustc_hash::FxHashSet::default(), |
| 221 | identifier_locs, |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | /// Check if a scope is the component scope or a descendant of it. |
| 226 | /// Used to determine whether a binding is local to the compiled function |
| 227 | /// or belongs to an ancestor function scope (e.g., a factory function |
| 228 | /// wrapping a nested component declaration). |
| 229 | /// Uses component_scope (the outermost compiled function's scope) rather |
| 230 | /// than function_scope because inner function expressions within the |
| 231 | /// compiled function have their own function_scope but still consider |
| 232 | /// the outer component's variables as local. |
| 233 | fn is_scope_within_compiled_function(&self, scope_id: ScopeId) -> bool { |
| 234 | let mut current = Some(scope_id); |
| 235 | while let Some(id) = current { |
| 236 | if id == self.component_scope { |
| 237 | return true; |
| 238 | } |
| 239 | current = self.scope_info.scopes[id.0 as usize].parent; |
| 240 | } |
| 241 | false |
| 242 | } |
| 243 | |
| 244 | /// Access the environment. |
| 245 | pub fn environment(&self) -> &Environment { |
| 246 | self.env |
| 247 | } |
| 248 | |
| 249 | /// Access the environment mutably. |
| 250 | pub fn environment_mut(&mut self) -> &mut Environment { |
| 251 | self.env |
| 252 | } |
| 253 | |
| 254 | /// Create a new unique TypeVar type, allocated from the environment's type arena |
| 255 | /// so that TypeIds are consistent with identifier type slots. |
| 256 | pub fn make_type(&mut self) -> Type { |
| 257 | let type_id = self.env.make_type(); |
| 258 | Type::TypeVar { id: type_id } |
| 259 | } |
| 260 | |
| 261 | /// Access the scope info. |
| 262 | pub fn scope_info(&self) -> &ScopeInfo { |
| 263 | self.scope_info |
| 264 | } |
| 265 | |
| 266 | /// Look up the source location of an identifier by its node_id. |
| 267 | pub fn get_identifier_loc(&self, node_id: u32) -> Option<SourceLocation> { |
| 268 | self.identifier_locs |
| 269 | .get(&node_id) |
| 270 | .map(|entry| entry.loc.clone()) |
| 271 | } |
| 272 | |
| 273 | /// Check whether a reference at the given byte offset corresponds to a |
| 274 | /// JSXIdentifier. Scans the node_id-keyed index for an entry whose stored |
| 275 | /// `start` matches the offset. |
| 276 | pub fn is_jsx_identifier_at_pos(&self, offset: u32) -> bool { |
| 277 | self.identifier_locs |
| 278 | .values() |
| 279 | .any(|entry| entry.start == offset && entry.is_jsx) |
| 280 | } |
| 281 | |
| 282 | /// Access the function scope (the scope of the function being compiled). |
| 283 | pub fn function_scope(&self) -> ScopeId { |
| 284 | self.function_scope |
| 285 | } |
| 286 | |
| 287 | /// Access the component scope. |
| 288 | pub fn component_scope(&self) -> ScopeId { |
| 289 | self.component_scope |
| 290 | } |
| 291 | |
| 292 | /// Access the context map. |
| 293 | pub fn context(&self) -> &IndexMap<BindingId, Option<SourceLocation>, FxBuildHasher> { |
| 294 | &self.context |
| 295 | } |
| 296 | |
| 297 | /// Access the pre-computed context identifiers set. |
| 298 | pub fn context_identifiers(&self) -> &rustc_hash::FxHashSet<BindingId> { |
| 299 | &self.context_identifiers |
| 300 | } |
| 301 | |
| 302 | /// Add a binding to the context identifiers set (used by hoisting). |
| 303 | pub fn add_context_identifier(&mut self, binding_id: BindingId) { |
| 304 | self.context_identifiers.insert(binding_id); |
| 305 | } |
| 306 | |
| 307 | pub fn claim_synthetic_scope(&mut self, scope_id: ScopeId) { |
| 308 | self.claimed_synthetic_scopes.insert(scope_id); |
| 309 | } |
| 310 | |
| 311 | pub fn is_synthetic_scope_claimed(&self, scope_id: ScopeId) -> bool { |
| 312 | self.claimed_synthetic_scopes.contains(&scope_id) |
| 313 | } |
| 314 | |
| 315 | /// Access scope_info and environment mutably at the same time. |
| 316 | /// This is safe because they are disjoint fields, but Rust's borrow checker |
| 317 | /// can't prove this through method calls alone. |
| 318 | pub fn scope_info_and_env_mut(&mut self) -> (&ScopeInfo, &mut Environment) { |
| 319 | (self.scope_info, self.env) |
| 320 | } |
| 321 | |
| 322 | /// Access the identifier location index. |
| 323 | /// Returns the 'a reference to avoid conflicts with mutable borrows on self. |
| 324 | pub fn identifier_locs(&self) -> &'a IdentifierLocIndex { |
| 325 | self.identifier_locs |
| 326 | } |
| 327 | |
| 328 | /// Access the bindings map. |
| 329 | pub fn bindings(&self) -> &IndexMap<BindingId, IdentifierId, FxBuildHasher> { |
| 330 | &self.bindings |
| 331 | } |
| 332 | |
| 333 | /// Access the used names map. |
| 334 | pub fn used_names(&self) -> &IndexMap<String, BindingId, FxBuildHasher> { |
| 335 | &self.used_names |
| 336 | } |
| 337 | |
| 338 | /// Merge used names from a child builder back into this builder. |
| 339 | /// This ensures name deduplication works across function scopes. |
| 340 | pub fn merge_used_names( |
| 341 | &mut self, |
| 342 | child_used_names: IndexMap<String, BindingId, FxBuildHasher>, |
| 343 | ) { |
| 344 | for (name, binding_id) in child_used_names { |
| 345 | self.used_names.entry(name).or_insert(binding_id); |
| 346 | } |
| 347 | } |
| 348 | |
| 349 | /// Merge bindings (binding_id -> IdentifierId) from a child builder back into this builder. |
| 350 | /// This matches TS behavior where parent and child share the same #bindings map by reference, |
| 351 | /// so bindings resolved by the child are automatically visible to the parent. |
| 352 | pub fn merge_bindings( |
| 353 | &mut self, |
| 354 | child_bindings: IndexMap<BindingId, IdentifierId, FxBuildHasher>, |
| 355 | ) { |
| 356 | for (binding_id, identifier_id) in child_bindings { |
| 357 | self.bindings.entry(binding_id).or_insert(identifier_id); |
| 358 | } |
| 359 | } |
| 360 | |
| 361 | /// Push an instruction onto the current block. |
| 362 | /// |
| 363 | /// Adds the instruction to the flat instruction table and records |
| 364 | /// its InstructionId in the current block's instruction list. |
| 365 | /// |
| 366 | /// If an exception handler is active, also emits a MaybeThrow terminal |
| 367 | /// after the instruction to model potential control flow to the handler, |
| 368 | /// then continues in a new block. |
| 369 | pub fn push(&mut self, instruction: Instruction) { |
| 370 | let loc = instruction.loc.clone(); |
| 371 | let instr_id = InstructionId(self.instruction_table.len() as u32); |
| 372 | self.instruction_table.push(instruction); |
| 373 | self.current.instructions.push(instr_id); |
| 374 | |
| 375 | if let Some(&handler) = self.exception_handler_stack.last() { |
| 376 | let continuation = self.reserve(self.current_block_kind()); |
| 377 | self.terminate_with_continuation( |
| 378 | Terminal::MaybeThrow { |
| 379 | continuation: continuation.id, |
| 380 | handler: Some(handler), |
| 381 | id: EvaluationOrder(0), |
| 382 | loc, |
| 383 | effects: None, |
| 384 | }, |
| 385 | continuation, |
| 386 | ); |
| 387 | } |
| 388 | } |
| 389 | |
| 390 | /// Terminate the current block with the given terminal and start a new block. |
| 391 | /// |
| 392 | /// If `next_block_kind` is `Some`, a new current block is created with that kind. |
| 393 | /// Returns the BlockId of the completed block. |
| 394 | pub fn terminate(&mut self, terminal: Terminal, next_block_kind: Option<BlockKind>) -> BlockId { |
| 395 | // The placeholder block created here (BlockId(u32::MAX)) is only used when |
| 396 | // next_block_kind is None, meaning this is the final terminate() call. |
| 397 | // It will never be read or completed because build() consumes self |
| 398 | // immediately after, and no further operations should occur on the builder. |
| 399 | let wip = std::mem::replace( |
| 400 | &mut self.current, |
| 401 | new_block(BlockId(u32::MAX), BlockKind::Block), |
| 402 | ); |
| 403 | let block_id = wip.id; |
| 404 | |
| 405 | self.completed.insert( |
| 406 | block_id, |
| 407 | BasicBlock { |
| 408 | kind: wip.kind, |
| 409 | id: block_id, |
| 410 | instructions: wip.instructions, |
| 411 | terminal, |
| 412 | preds: IndexSet::default(), |
| 413 | phis: Vec::new(), |
| 414 | }, |
| 415 | ); |
| 416 | |
| 417 | if let Some(kind) = next_block_kind { |
| 418 | let next_id = self.env.next_block_id(); |
| 419 | self.current = new_block(next_id, kind); |
| 420 | } |
| 421 | block_id |
| 422 | } |
| 423 | |
| 424 | /// Terminate the current block with the given terminal, and set |
| 425 | /// a previously reserved block as the new current block. |
| 426 | pub fn terminate_with_continuation(&mut self, terminal: Terminal, continuation: WipBlock) { |
| 427 | let wip = std::mem::replace(&mut self.current, continuation); |
| 428 | let block_id = wip.id; |
| 429 | self.completed.insert( |
| 430 | block_id, |
| 431 | BasicBlock { |
| 432 | kind: wip.kind, |
| 433 | id: block_id, |
| 434 | instructions: wip.instructions, |
| 435 | terminal, |
| 436 | preds: IndexSet::default(), |
| 437 | phis: Vec::new(), |
| 438 | }, |
| 439 | ); |
| 440 | } |
| 441 | |
| 442 | /// Reserve a new block so it can be referenced before construction. |
| 443 | /// Use `terminate_with_continuation()` to make it current, or `complete()` to |
| 444 | /// save it directly. |
| 445 | pub fn reserve(&mut self, kind: BlockKind) -> WipBlock { |
| 446 | let id = self.env.next_block_id(); |
| 447 | new_block(id, kind) |
| 448 | } |
| 449 | |
| 450 | /// Save a previously reserved block as completed with the given terminal. |
| 451 | pub fn complete(&mut self, block: WipBlock, terminal: Terminal) { |
| 452 | let block_id = block.id; |
| 453 | self.completed.insert( |
| 454 | block_id, |
| 455 | BasicBlock { |
| 456 | kind: block.kind, |
| 457 | id: block_id, |
| 458 | instructions: block.instructions, |
| 459 | terminal, |
| 460 | preds: IndexSet::default(), |
| 461 | phis: Vec::new(), |
| 462 | }, |
| 463 | ); |
| 464 | } |
| 465 | |
| 466 | /// Sets the given wip block as current, executes the closure to populate |
| 467 | /// it and obtain its terminal, then completes the block and restores the |
| 468 | /// previous current block. |
| 469 | pub fn enter_reserved(&mut self, wip: WipBlock, f: impl FnOnce(&mut Self) -> Terminal) { |
| 470 | let prev = std::mem::replace(&mut self.current, wip); |
| 471 | let terminal = f(self); |
| 472 | let completed_wip = std::mem::replace(&mut self.current, prev); |
| 473 | self.completed.insert( |
| 474 | completed_wip.id, |
| 475 | BasicBlock { |
| 476 | kind: completed_wip.kind, |
| 477 | id: completed_wip.id, |
| 478 | instructions: completed_wip.instructions, |
| 479 | terminal, |
| 480 | preds: IndexSet::default(), |
| 481 | phis: Vec::new(), |
| 482 | }, |
| 483 | ); |
| 484 | } |
| 485 | |
| 486 | /// Like `enter_reserved`, but the closure returns a `Result<Terminal, CompilerDiagnostic>`. |
| 487 | pub fn try_enter_reserved( |
| 488 | &mut self, |
| 489 | wip: WipBlock, |
| 490 | f: impl FnOnce(&mut Self) -> Result<Terminal, CompilerDiagnostic>, |
| 491 | ) -> Result<(), CompilerDiagnostic> { |
| 492 | let prev = std::mem::replace(&mut self.current, wip); |
| 493 | let terminal = f(self)?; |
| 494 | let completed_wip = std::mem::replace(&mut self.current, prev); |
| 495 | self.completed.insert( |
| 496 | completed_wip.id, |
| 497 | BasicBlock { |
| 498 | kind: completed_wip.kind, |
| 499 | id: completed_wip.id, |
| 500 | instructions: completed_wip.instructions, |
| 501 | terminal, |
| 502 | preds: IndexSet::default(), |
| 503 | phis: Vec::new(), |
| 504 | }, |
| 505 | ); |
| 506 | Ok(()) |
| 507 | } |
| 508 | |
| 509 | /// Create a new block, set it as current, run the closure to populate it |
| 510 | /// and obtain its terminal, complete the block, and restore the previous |
| 511 | /// current block. Returns the new block's BlockId. |
| 512 | pub fn enter( |
| 513 | &mut self, |
| 514 | kind: BlockKind, |
| 515 | f: impl FnOnce(&mut Self, BlockId) -> Terminal, |
| 516 | ) -> BlockId { |
| 517 | let wip = self.reserve(kind); |
| 518 | let wip_id = wip.id; |
| 519 | self.enter_reserved(wip, |this| f(this, wip_id)); |
| 520 | wip_id |
| 521 | } |
| 522 | |
| 523 | /// Like `enter`, but the closure returns a `Result<Terminal, CompilerDiagnostic>`. |
| 524 | pub fn try_enter( |
| 525 | &mut self, |
| 526 | kind: BlockKind, |
| 527 | f: impl FnOnce(&mut Self, BlockId) -> Result<Terminal, CompilerDiagnostic>, |
| 528 | ) -> Result<BlockId, CompilerDiagnostic> { |
| 529 | let wip = self.reserve(kind); |
| 530 | let wip_id = wip.id; |
| 531 | self.try_enter_reserved(wip, |this| f(this, wip_id))?; |
| 532 | Ok(wip_id) |
| 533 | } |
| 534 | |
| 535 | /// Push an exception handler, run the closure, then pop the handler. |
| 536 | pub fn enter_try_catch(&mut self, handler: BlockId, f: impl FnOnce(&mut Self)) { |
| 537 | self.exception_handler_stack.push(handler); |
| 538 | f(self); |
| 539 | self.exception_handler_stack.pop(); |
| 540 | } |
| 541 | |
| 542 | /// Like `enter_try_catch`, but the closure returns a `Result`. |
| 543 | pub fn try_enter_try_catch( |
| 544 | &mut self, |
| 545 | handler: BlockId, |
| 546 | f: impl FnOnce(&mut Self) -> Result<(), CompilerDiagnostic>, |
| 547 | ) -> Result<(), CompilerDiagnostic> { |
| 548 | self.exception_handler_stack.push(handler); |
| 549 | let result = f(self); |
| 550 | self.exception_handler_stack.pop(); |
| 551 | result |
| 552 | } |
| 553 | |
| 554 | /// Return the top of the exception handler stack, or None. |
| 555 | pub fn resolve_throw_handler(&self) -> Option<BlockId> { |
| 556 | self.exception_handler_stack.last().copied() |
| 557 | } |
| 558 | |
| 559 | /// Push a Loop scope, run the closure, pop and verify. |
| 560 | pub fn loop_scope<T>( |
| 561 | &mut self, |
| 562 | label: Option<String>, |
| 563 | continue_block: BlockId, |
| 564 | break_block: BlockId, |
| 565 | f: impl FnOnce(&mut Self) -> Result<T, CompilerDiagnostic>, |
| 566 | ) -> Result<T, CompilerDiagnostic> { |
| 567 | self.scopes.push(Scope::Loop { |
| 568 | label: label.clone(), |
| 569 | continue_block, |
| 570 | break_block, |
| 571 | }); |
| 572 | let value = f(self)?; |
| 573 | let last = self |
| 574 | .scopes |
| 575 | .pop() |
| 576 | .expect("Mismatched loop scope: stack empty"); |
| 577 | match &last { |
| 578 | Scope::Loop { |
| 579 | label: l, |
| 580 | continue_block: c, |
| 581 | break_block: b, |
| 582 | } => { |
| 583 | assert!( |
| 584 | *l == label && *c == continue_block && *b == break_block, |
| 585 | "Mismatched loop scope" |
| 586 | ); |
| 587 | } |
| 588 | _ => { |
| 589 | return Err(CompilerDiagnostic::new( |
| 590 | ErrorCategory::Invariant, |
| 591 | "Mismatched loop scope: expected Loop, got other", |
| 592 | None, |
| 593 | )); |
| 594 | } |
| 595 | } |
| 596 | Ok(value) |
| 597 | } |
| 598 | |
| 599 | /// Push a Label scope, run the closure, pop and verify. |
| 600 | pub fn label_scope<T>( |
| 601 | &mut self, |
| 602 | label: String, |
| 603 | break_block: BlockId, |
| 604 | f: impl FnOnce(&mut Self) -> Result<T, CompilerDiagnostic>, |
| 605 | ) -> Result<T, CompilerDiagnostic> { |
| 606 | self.scopes.push(Scope::Label { |
| 607 | label: label.clone(), |
| 608 | break_block, |
| 609 | }); |
| 610 | let value = f(self)?; |
| 611 | let last = self |
| 612 | .scopes |
| 613 | .pop() |
| 614 | .expect("Mismatched label scope: stack empty"); |
| 615 | match &last { |
| 616 | Scope::Label { |
| 617 | label: l, |
| 618 | break_block: b, |
| 619 | } => { |
| 620 | assert!(*l == label && *b == break_block, "Mismatched label scope"); |
| 621 | } |
| 622 | _ => { |
| 623 | return Err(CompilerDiagnostic::new( |
| 624 | ErrorCategory::Invariant, |
| 625 | "Mismatched label scope: expected Label, got other", |
| 626 | None, |
| 627 | )); |
| 628 | } |
| 629 | } |
| 630 | Ok(value) |
| 631 | } |
| 632 | |
| 633 | /// Push a Switch scope, run the closure, pop and verify. |
| 634 | pub fn switch_scope<T>( |
| 635 | &mut self, |
| 636 | label: Option<String>, |
| 637 | break_block: BlockId, |
| 638 | f: impl FnOnce(&mut Self) -> Result<T, CompilerDiagnostic>, |
| 639 | ) -> Result<T, CompilerDiagnostic> { |
| 640 | self.scopes.push(Scope::Switch { |
| 641 | label: label.clone(), |
| 642 | break_block, |
| 643 | }); |
| 644 | let value = f(self)?; |
| 645 | let last = self |
| 646 | .scopes |
| 647 | .pop() |
| 648 | .expect("Mismatched switch scope: stack empty"); |
| 649 | match &last { |
| 650 | Scope::Switch { |
| 651 | label: l, |
| 652 | break_block: b, |
| 653 | } => { |
| 654 | assert!(*l == label && *b == break_block, "Mismatched switch scope"); |
| 655 | } |
| 656 | _ => { |
| 657 | return Err(CompilerDiagnostic::new( |
| 658 | ErrorCategory::Invariant, |
| 659 | "Mismatched switch scope: expected Switch, got other", |
| 660 | None, |
| 661 | )); |
| 662 | } |
| 663 | } |
| 664 | Ok(value) |
| 665 | } |
| 666 | |
| 667 | /// Look up the break target for the given label (or the innermost |
| 668 | /// loop/switch if label is None). |
| 669 | pub fn lookup_break(&self, label: Option<&str>) -> Result<BlockId, CompilerDiagnostic> { |
| 670 | for scope in self.scopes.iter().rev() { |
| 671 | match scope { |
| 672 | Scope::Loop { .. } | Scope::Switch { .. } if label.is_none() => { |
| 673 | return Ok(scope.break_block()); |
| 674 | } |
| 675 | _ if label.is_some() && scope.label() == label => { |
| 676 | return Ok(scope.break_block()); |
| 677 | } |
| 678 | _ => continue, |
| 679 | } |
| 680 | } |
| 681 | Err(CompilerDiagnostic::new( |
| 682 | ErrorCategory::Invariant, |
| 683 | "Expected a loop or switch to be in scope for break", |
| 684 | None, |
| 685 | )) |
| 686 | } |
| 687 | |
| 688 | /// Look up the continue target for the given label (or the innermost |
| 689 | /// loop if label is None). Only loops support continue. |
| 690 | pub fn lookup_continue(&self, label: Option<&str>) -> Result<BlockId, CompilerDiagnostic> { |
| 691 | for scope in self.scopes.iter().rev() { |
| 692 | match scope { |
| 693 | Scope::Loop { |
| 694 | label: scope_label, |
| 695 | continue_block, |
| 696 | .. |
| 697 | } => { |
| 698 | if label.is_none() || label == scope_label.as_deref() { |
| 699 | return Ok(*continue_block); |
| 700 | } |
| 701 | } |
| 702 | _ => { |
| 703 | if label.is_some() && scope.label() == label { |
| 704 | return Err(CompilerDiagnostic::new( |
| 705 | ErrorCategory::Invariant, |
| 706 | "Continue may only refer to a labeled loop", |
| 707 | None, |
| 708 | )); |
| 709 | } |
| 710 | } |
| 711 | } |
| 712 | } |
| 713 | Err(CompilerDiagnostic::new( |
| 714 | ErrorCategory::Invariant, |
| 715 | "Expected a loop to be in scope for continue", |
| 716 | None, |
| 717 | )) |
| 718 | } |
| 719 | |
| 720 | /// Create a temporary identifier with a fresh id, returning its IdentifierId. |
| 721 | pub fn make_temporary(&mut self, loc: Option<SourceLocation>) -> IdentifierId { |
| 722 | let id = self.env.next_identifier_id(); |
| 723 | // Update the loc on the allocated identifier |
| 724 | self.env.identifiers[id.0 as usize].loc = loc; |
| 725 | id |
| 726 | } |
| 727 | |
| 728 | /// Set the source location for an identifier. |
| 729 | pub fn set_identifier_loc(&mut self, id: IdentifierId, loc: Option<SourceLocation>) { |
| 730 | self.env.identifiers[id.0 as usize].loc = loc; |
| 731 | } |
| 732 | |
| 733 | /// Record an error on the environment. |
| 734 | /// Returns `Err` for Invariant errors (matching TS throw behavior). |
| 735 | pub fn record_error(&mut self, error: CompilerErrorDetail) -> Result<(), CompilerError> { |
| 736 | self.env.record_error(error) |
| 737 | } |
| 738 | |
| 739 | /// Record a diagnostic on the environment. |
| 740 | pub fn record_diagnostic(&mut self, diagnostic: CompilerDiagnostic) { |
| 741 | self.env.record_diagnostic(diagnostic); |
| 742 | } |
| 743 | |
| 744 | /// Check if a name has a local binding (non-module-level). |
| 745 | /// This is used for checking if fbt/fbs JSX tags are local bindings |
| 746 | /// (which is not supported). |
| 747 | pub fn has_local_binding(&self, name: &str) -> bool { |
| 748 | if let Some(binding) = self |
| 749 | .scope_info |
| 750 | .find_binding_in_descendants(name, self.component_scope) |
| 751 | { |
| 752 | // When component_scope == program_scope (e2e path where scope info |
| 753 | // is extracted from the function itself), any binding found is local. |
| 754 | if self.component_scope == self.scope_info.program_scope { |
| 755 | return true; |
| 756 | } |
| 757 | return binding.scope != self.scope_info.program_scope; |
| 758 | } |
| 759 | false |
| 760 | } |
| 761 | |
| 762 | /// Return the kind of the current block. |
| 763 | pub fn current_block_kind(&self) -> BlockKind { |
| 764 | self.current.kind |
| 765 | } |
| 766 | |
| 767 | /// Construct the final HIR and instruction table from the completed blocks. |
| 768 | /// |
| 769 | /// Performs these post-build passes: |
| 770 | /// 1. Reverse-postorder sort + unreachable block removal |
| 771 | /// 2. Check for unreachable blocks containing FunctionExpression instructions |
| 772 | /// 3. Remove unreachable for-loop updates |
| 773 | /// 4. Remove dead do-while statements |
| 774 | /// 5. Remove unnecessary try-catch |
| 775 | /// 6. Number all instructions and terminals |
| 776 | /// 7. Mark predecessor blocks |
| 777 | pub fn build( |
| 778 | mut self, |
| 779 | ) -> Result< |
| 780 | ( |
| 781 | HIR, |
| 782 | Vec<Instruction>, |
| 783 | IndexMap<String, BindingId, FxBuildHasher>, |
| 784 | IndexMap<BindingId, IdentifierId, FxBuildHasher>, |
| 785 | ), |
| 786 | CompilerError, |
| 787 | > { |
| 788 | let mut hir = HIR { |
| 789 | blocks: std::mem::take(&mut self.completed), |
| 790 | entry: self.entry, |
| 791 | }; |
| 792 | |
| 793 | let mut instructions = std::mem::take(&mut self.instruction_table); |
| 794 | |
| 795 | let rpo_blocks = get_reverse_postordered_blocks(&hir, &instructions); |
| 796 | |
| 797 | // Check for unreachable blocks that contain FunctionExpression instructions. |
| 798 | // These could contain hoisted declarations that we can't safely remove. |
| 799 | for (id, block) in &hir.blocks { |
| 800 | if !rpo_blocks.contains_key(id) { |
| 801 | let has_function_expr = block.instructions.iter().any(|&instr_id| { |
| 802 | matches!( |
| 803 | instructions[instr_id.0 as usize].value, |
| 804 | InstructionValue::FunctionExpression { .. } |
| 805 | ) |
| 806 | }); |
| 807 | if has_function_expr { |
| 808 | let loc = block |
| 809 | .instructions |
| 810 | .first() |
| 811 | .and_then(|&i| instructions[i.0 as usize].loc.clone()) |
| 812 | .or_else(|| block.terminal.loc().copied()); |
| 813 | self.env.record_error(CompilerErrorDetail { |
| 814 | category: ErrorCategory::Todo, |
| 815 | reason: "Support functions with unreachable code that may contain hoisted declarations".to_string(), |
| 816 | description: None, |
| 817 | loc, |
| 818 | suggestions: None, |
| 819 | })?; |
| 820 | } |
| 821 | } |
| 822 | } |
| 823 | |
| 824 | hir.blocks = rpo_blocks; |
| 825 | |
| 826 | remove_unreachable_for_updates(&mut hir); |
| 827 | remove_dead_do_while_statements(&mut hir); |
| 828 | remove_unnecessary_try_catch(&mut hir); |
| 829 | mark_instruction_ids(&mut hir, &mut instructions); |
| 830 | mark_predecessors(&mut hir); |
| 831 | |
| 832 | let used_names = self.used_names; |
| 833 | let bindings = self.bindings; |
| 834 | Ok((hir, instructions, used_names, bindings)) |
| 835 | } |
| 836 | |
| 837 | // ----------------------------------------------------------------------- |
| 838 | // M3: Binding resolution methods |
| 839 | // ----------------------------------------------------------------------- |
| 840 | |
| 841 | /// Map a BindingId to an HIR IdentifierId. |
| 842 | /// |
| 843 | /// On first encounter, creates a new Identifier with the given name and a fresh id. |
| 844 | /// On subsequent encounters, returns the cached IdentifierId. |
| 845 | /// Handles name collisions by appending `_0`, `_1`, etc. |
| 846 | /// |
| 847 | /// Records errors for variables named 'fbt' or 'this'. |
| 848 | pub fn resolve_binding( |
| 849 | &mut self, |
| 850 | name: &str, |
| 851 | binding_id: BindingId, |
| 852 | ) -> Result<IdentifierId, CompilerError> { |
| 853 | self.resolve_binding_with_loc(name, binding_id, None) |
| 854 | } |
| 855 | |
| 856 | /// Map a BindingId to an HIR IdentifierId, with an optional source location. |
| 857 | pub fn resolve_binding_with_loc( |
| 858 | &mut self, |
| 859 | name: &str, |
| 860 | binding_id: BindingId, |
| 861 | loc: Option<SourceLocation>, |
| 862 | ) -> Result<IdentifierId, CompilerError> { |
| 863 | // Check for unsupported names BEFORE the cache check. |
| 864 | // In TS, resolveBinding records fbt errors when node.name === 'fbt'. After a name collision |
| 865 | // causes a rename (e.g., "fbt" -> "fbt_0"), TS's scope.rename changes the AST node's name, |
| 866 | // preventing subsequent fbt error recording. We simulate this by checking whether the |
| 867 | // resolved name for this binding is still "fbt" (not renamed to "fbt_0" etc.). |
| 868 | if name == "fbt" { |
| 869 | // Check if this binding was previously resolved to a renamed version |
| 870 | let should_record_fbt_error = |
| 871 | if let Some(&identifier_id) = self.bindings.get(&binding_id) { |
| 872 | // Already resolved - check if the resolved name is still "fbt" |
| 873 | match &self.env.identifiers[identifier_id.0 as usize].name { |
| 874 | Some(IdentifierName::Named(resolved_name)) => resolved_name == "fbt", |
| 875 | _ => false, |
| 876 | } |
| 877 | } else { |
| 878 | // First resolution - always record |
| 879 | true |
| 880 | }; |
| 881 | if should_record_fbt_error { |
| 882 | let error_loc = self.scope_info.bindings[binding_id.0 as usize] |
| 883 | .declaration_node_id |
| 884 | .and_then(|nid| self.get_identifier_loc(nid)) |
| 885 | .or_else(|| loc.clone()); |
| 886 | self.env.record_error(CompilerErrorDetail { |
| 887 | category: ErrorCategory::Todo, |
| 888 | reason: "Support local variables named `fbt`".to_string(), |
| 889 | description: Some( |
| 890 | "Local variables named `fbt` may conflict with the fbt plugin and are not yet supported".to_string(), |
| 891 | ), |
| 892 | loc: error_loc, |
| 893 | suggestions: None, |
| 894 | })?; |
| 895 | } |
| 896 | } |
| 897 | |
| 898 | // If we've already resolved this binding, return the cached IdentifierId |
| 899 | if let Some(&identifier_id) = self.bindings.get(&binding_id) { |
| 900 | return Ok(identifier_id); |
| 901 | } |
| 902 | |
| 903 | if is_always_reserved_word(name) { |
| 904 | // Match TS behavior: makeIdentifierName throws for reserved words. |
| 905 | return Err(CompilerError::from(reserved_identifier_diagnostic(name))); |
| 906 | } |
| 907 | |
| 908 | // Find a unique name: start with the original name, then try name_0, name_1, ... |
| 909 | let mut candidate = name.to_string(); |
| 910 | let mut index = 0u32; |
| 911 | loop { |
| 912 | if let Some(&existing_binding_id) = self.used_names.get(&candidate) { |
| 913 | if existing_binding_id == binding_id { |
| 914 | // Same binding, use this name |
| 915 | break; |
| 916 | } |
| 917 | // Name collision with a different binding, try the next suffix |
| 918 | candidate = format!("{}_{}", name, index); |
| 919 | index += 1; |
| 920 | } else { |
| 921 | // Name is available |
| 922 | break; |
| 923 | } |
| 924 | } |
| 925 | |
| 926 | // Record rename if the candidate differs from the original name |
| 927 | if candidate != name { |
| 928 | let binding = &self.scope_info.bindings[binding_id.0 as usize]; |
| 929 | if let Some(decl_start) = binding.declaration_start { |
| 930 | self.env |
| 931 | .renames |
| 932 | .push(react_compiler_hir::environment::BindingRename { |
| 933 | original: name.to_string(), |
| 934 | renamed: candidate.clone(), |
| 935 | declaration_start: decl_start, |
| 936 | }); |
| 937 | } |
| 938 | } |
| 939 | |
| 940 | // Allocate identifier in the arena |
| 941 | let id = self.env.next_identifier_id(); |
| 942 | // Update the name and loc on the allocated identifier |
| 943 | self.env.identifiers[id.0 as usize].name = Some(IdentifierName::Named(candidate.clone())); |
| 944 | // Prefer the binding's declaration loc over the reference loc. |
| 945 | // This matches TS behavior where Babel's resolveBinding returns the |
| 946 | // binding identifier's original loc (the declaration site). |
| 947 | let binding = &self.scope_info.bindings[binding_id.0 as usize]; |
| 948 | let decl_loc = binding |
| 949 | .declaration_node_id |
| 950 | .and_then(|nid| self.get_identifier_loc(nid)); |
| 951 | if let Some(ref dl) = decl_loc { |
| 952 | self.env.identifiers[id.0 as usize].loc = Some(dl.clone()); |
| 953 | } else if let Some(ref loc) = loc { |
| 954 | self.env.identifiers[id.0 as usize].loc = Some(loc.clone()); |
| 955 | } |
| 956 | |
| 957 | self.used_names.insert(candidate, binding_id); |
| 958 | self.bindings.insert(binding_id, id); |
| 959 | Ok(id) |
| 960 | } |
| 961 | |
| 962 | /// Set the loc on an identifier to the declaration-site loc. |
| 963 | /// This overrides any previously-set loc (which may have come from a reference site). |
| 964 | pub fn set_identifier_declaration_loc( |
| 965 | &mut self, |
| 966 | id: IdentifierId, |
| 967 | loc: &Option<SourceLocation>, |
| 968 | ) { |
| 969 | if let Some(loc_val) = loc { |
| 970 | self.env.identifiers[id.0 as usize].loc = Some(loc_val.clone()); |
| 971 | } |
| 972 | } |
| 973 | |
| 974 | /// Resolve an identifier reference to a VariableBinding. |
| 975 | /// |
| 976 | /// Uses ScopeInfo to determine whether the reference is: |
| 977 | /// - Global (no binding found) |
| 978 | /// - ImportDefault, ImportSpecifier, ImportNamespace (program-scope import binding) |
| 979 | /// - ModuleLocal (program-scope non-import binding) |
| 980 | /// - Identifier (local binding, resolved via resolve_binding) |
| 981 | pub fn resolve_identifier( |
| 982 | &mut self, |
| 983 | name: &str, |
| 984 | _start_offset: u32, |
| 985 | loc: Option<SourceLocation>, |
| 986 | node_id: Option<u32>, |
| 987 | ) -> Result<VariableBinding, CompilerError> { |
| 988 | let binding_data = self.scope_info.resolve_reference_for_node(node_id); |
| 989 | |
| 990 | match binding_data { |
| 991 | None => { |
| 992 | // No binding found: this is a global |
| 993 | Ok(VariableBinding::Global { |
| 994 | name: name.to_string(), |
| 995 | }) |
| 996 | } |
| 997 | Some(binding) => { |
| 998 | // Treat type-only declarations as globals so the compiler |
| 999 | // doesn't try to create/initialize HIR bindings for them. |
| 1000 | // TSEnumDeclaration is included because enums inside function |
| 1001 | // bodies are lowered as UnsupportedNode and their binding |
| 1002 | // is never initialized in HIR. |
| 1003 | if matches!( |
| 1004 | binding.declaration_type.as_str(), |
| 1005 | "TSTypeAliasDeclaration" |
| 1006 | | "TSInterfaceDeclaration" |
| 1007 | | "TSEnumDeclaration" |
| 1008 | | "TSModuleDeclaration" |
| 1009 | ) { |
| 1010 | return Ok(VariableBinding::Global { |
| 1011 | name: name.to_string(), |
| 1012 | }); |
| 1013 | } |
| 1014 | if binding.scope == self.scope_info.program_scope { |
| 1015 | // Module-level binding: check import info |
| 1016 | Ok(match &binding.import { |
| 1017 | Some(import_info) => match import_info.kind { |
| 1018 | ImportBindingKind::Default => VariableBinding::ImportDefault { |
| 1019 | name: name.to_string(), |
| 1020 | module: import_info.source.clone(), |
| 1021 | }, |
| 1022 | ImportBindingKind::Named => VariableBinding::ImportSpecifier { |
| 1023 | name: name.to_string(), |
| 1024 | module: import_info.source.clone(), |
| 1025 | imported: import_info |
| 1026 | .imported |
| 1027 | .clone() |
| 1028 | .unwrap_or_else(|| name.to_string()), |
| 1029 | }, |
| 1030 | ImportBindingKind::Namespace => VariableBinding::ImportNamespace { |
| 1031 | name: name.to_string(), |
| 1032 | module: import_info.source.clone(), |
| 1033 | }, |
| 1034 | }, |
| 1035 | None => VariableBinding::ModuleLocal { |
| 1036 | name: name.to_string(), |
| 1037 | }, |
| 1038 | }) |
| 1039 | } else if !self.is_scope_within_compiled_function(binding.scope) { |
| 1040 | Ok(VariableBinding::ModuleLocal { |
| 1041 | name: name.to_string(), |
| 1042 | }) |
| 1043 | } else { |
| 1044 | let binding_id = binding.id; |
| 1045 | let binding_kind = crate::convert_binding_kind(&binding.kind); |
| 1046 | let identifier_id = self.resolve_binding_with_loc(name, binding_id, loc)?; |
| 1047 | Ok(VariableBinding::Identifier { |
| 1048 | identifier: identifier_id, |
| 1049 | binding_kind, |
| 1050 | }) |
| 1051 | } |
| 1052 | } |
| 1053 | } |
| 1054 | } |
| 1055 | |
| 1056 | /// Check if an identifier reference resolves to a context identifier. |
| 1057 | /// |
| 1058 | /// A context identifier is a variable declared in an ancestor scope of the |
| 1059 | /// current function's scope, but NOT in the program scope itself and NOT |
| 1060 | /// in the function's own scope. These are "captured" variables from an |
| 1061 | /// enclosing function. |
| 1062 | pub fn is_context_identifier( |
| 1063 | &self, |
| 1064 | _name: &str, |
| 1065 | _start_offset: u32, |
| 1066 | node_id: Option<u32>, |
| 1067 | ) -> bool { |
| 1068 | let binding = self.scope_info.resolve_reference_for_node(node_id); |
| 1069 | |
| 1070 | match binding { |
| 1071 | None => false, |
| 1072 | Some(binding_data) => { |
| 1073 | if binding_data.scope == self.scope_info.program_scope { |
| 1074 | return false; |
| 1075 | } |
| 1076 | self.context_identifiers.contains(&binding_data.id) |
| 1077 | } |
| 1078 | } |
| 1079 | } |
| 1080 | |
| 1081 | /// Like `is_context_identifier`, for callers that already resolved a |
| 1082 | /// BindingId instead of going through a reference node. |
| 1083 | pub fn is_context_binding(&self, binding_id: BindingId) -> bool { |
| 1084 | let binding = &self.scope_info.bindings[binding_id.0 as usize]; |
| 1085 | if binding.scope == self.scope_info.program_scope { |
| 1086 | return false; |
| 1087 | } |
| 1088 | self.context_identifiers.contains(&binding_id) |
| 1089 | } |
| 1090 | |
| 1091 | /// Resolve the binding for a function declaration's id the way TS does: |
| 1092 | /// Babel's `path.scope.getBinding(name)` starts at the function's OWN |
| 1093 | /// scope, so a body-level local (or parameter) that shadows the function's |
| 1094 | /// name resolves to that inner binding rather than to the function's |
| 1095 | /// hoisted binding in the parent scope. |
| 1096 | /// |
| 1097 | /// Babel's `scope.rename` re-keys a scope's bindings when the TS builder |
| 1098 | /// renames a shadowed binding (e.g. `init` -> `init_0`), so a binding only |
| 1099 | /// matches if its *current* name — the resolved HIR identifier name once |
| 1100 | /// resolved — still equals `name`. A binding renamed *to* `name` overwrites |
| 1101 | /// the original key in Babel and takes precedence over an unresolved |
| 1102 | /// binding with that original name. |
| 1103 | /// |
| 1104 | /// Returns None when the walk resolves outside the compiled function |
| 1105 | /// (degraded scope info); callers should fall back to node-based |
| 1106 | /// resolution in that case. |
| 1107 | pub fn get_function_declaration_binding( |
| 1108 | &self, |
| 1109 | function_scope: ScopeId, |
| 1110 | name: &str, |
| 1111 | ) -> Option<BindingId> { |
| 1112 | // None = unresolved binding; Some(matches) = resolved, current name comparison |
| 1113 | let resolved_name_matches = |bid: BindingId| -> Option<bool> { |
| 1114 | let &identifier_id = self.bindings.get(&bid)?; |
| 1115 | match &self.env.identifiers[identifier_id.0 as usize].name { |
| 1116 | Some(IdentifierName::Named(n)) => Some(n == name), |
| 1117 | _ => Some(false), |
| 1118 | } |
| 1119 | }; |
| 1120 | let mut current = Some(function_scope); |
| 1121 | while let Some(id) = current { |
| 1122 | let scope = &self.scope_info.scopes[id.0 as usize]; |
| 1123 | let mut found = scope |
| 1124 | .bindings |
| 1125 | .values() |
| 1126 | .copied() |
| 1127 | .find(|&bid| resolved_name_matches(bid) == Some(true)); |
| 1128 | if found.is_none() { |
| 1129 | if let Some(&bid) = scope.bindings.get(name) { |
| 1130 | // Skip bindings that were renamed away from `name`. |
| 1131 | if resolved_name_matches(bid) != Some(false) { |
| 1132 | found = Some(bid); |
| 1133 | } |
| 1134 | } |
| 1135 | } |
| 1136 | if let Some(bid) = found { |
| 1137 | let binding_scope = self.scope_info.bindings[bid.0 as usize].scope; |
| 1138 | if !self.is_scope_within_compiled_function(binding_scope) { |
| 1139 | return None; |
| 1140 | } |
| 1141 | return Some(bid); |
| 1142 | } |
| 1143 | current = scope.parent; |
| 1144 | } |
| 1145 | None |
| 1146 | } |
| 1147 | } |
| 1148 | |
| 1149 | // --------------------------------------------------------------------------- |
| 1150 | // Post-build helper functions |
| 1151 | // --------------------------------------------------------------------------- |
| 1152 | |
| 1153 | /// Compute a reverse-postorder of blocks reachable from the entry. |
| 1154 | /// |
| 1155 | /// Visits successors in reverse order so that when the postorder list is |
| 1156 | /// reversed, sibling edges appear in program order. |
| 1157 | /// |
| 1158 | /// Blocks not reachable through successors are removed. Blocks that are |
| 1159 | /// only reachable as fallthroughs (not through real successor edges) are |
| 1160 | /// replaced with empty blocks that have an Unreachable terminal. |
| 1161 | pub fn get_reverse_postordered_blocks( |
| 1162 | hir: &HIR, |
| 1163 | _instructions: &[Instruction], |
| 1164 | ) -> IndexMap<BlockId, BasicBlock, FxBuildHasher> { |
| 1165 | let mut visited: IndexSet<BlockId, FxBuildHasher> = IndexSet::default(); |
| 1166 | let mut used: IndexSet<BlockId, FxBuildHasher> = IndexSet::default(); |
| 1167 | let mut used_fallthroughs: IndexSet<BlockId, FxBuildHasher> = IndexSet::default(); |
| 1168 | let mut postorder: Vec<BlockId> = Vec::new(); |
| 1169 | |
| 1170 | fn visit( |
| 1171 | hir: &HIR, |
| 1172 | block_id: BlockId, |
| 1173 | is_used: bool, |
| 1174 | visited: &mut IndexSet<BlockId, FxBuildHasher>, |
| 1175 | used: &mut IndexSet<BlockId, FxBuildHasher>, |
| 1176 | used_fallthroughs: &mut IndexSet<BlockId, FxBuildHasher>, |
| 1177 | postorder: &mut Vec<BlockId>, |
| 1178 | ) { |
| 1179 | let was_used = used.contains(&block_id); |
| 1180 | let was_visited = visited.contains(&block_id); |
| 1181 | visited.insert(block_id); |
| 1182 | if is_used { |
| 1183 | used.insert(block_id); |
| 1184 | } |
| 1185 | if was_visited && (was_used || !is_used) { |
| 1186 | return; |
| 1187 | } |
| 1188 | |
| 1189 | let block = hir |
| 1190 | .blocks |
| 1191 | .get(&block_id) |
| 1192 | .unwrap_or_else(|| panic!("[HIRBuilder] expected block {:?} to exist", block_id)); |
| 1193 | |
| 1194 | // Visit successors in reverse order so that when we reverse the |
| 1195 | // postorder list, sibling edges come out in program order. |
| 1196 | let mut successors = each_terminal_successor(&block.terminal); |
| 1197 | successors.reverse(); |
| 1198 | |
| 1199 | let fallthrough = terminal_fallthrough(&block.terminal); |
| 1200 | |
| 1201 | // Visit fallthrough first (marking as not-yet-used) to ensure its |
| 1202 | // block ID is emitted in the correct position. |
| 1203 | if let Some(ft) = fallthrough { |
| 1204 | if is_used { |
| 1205 | used_fallthroughs.insert(ft); |
| 1206 | } |
| 1207 | visit(hir, ft, false, visited, used, used_fallthroughs, postorder); |
| 1208 | } |
| 1209 | for successor in successors { |
| 1210 | visit( |
| 1211 | hir, |
| 1212 | successor, |
| 1213 | is_used, |
| 1214 | visited, |
| 1215 | used, |
| 1216 | used_fallthroughs, |
| 1217 | postorder, |
| 1218 | ); |
| 1219 | } |
| 1220 | |
| 1221 | if !was_visited { |
| 1222 | postorder.push(block_id); |
| 1223 | } |
| 1224 | } |
| 1225 | |
| 1226 | visit( |
| 1227 | hir, |
| 1228 | hir.entry, |
| 1229 | true, |
| 1230 | &mut visited, |
| 1231 | &mut used, |
| 1232 | &mut used_fallthroughs, |
| 1233 | &mut postorder, |
| 1234 | ); |
| 1235 | |
| 1236 | let mut blocks = IndexMap::default(); |
| 1237 | for block_id in postorder.into_iter().rev() { |
| 1238 | let block = hir.blocks.get(&block_id).unwrap(); |
| 1239 | if used.contains(&block_id) { |
| 1240 | blocks.insert(block_id, block.clone()); |
| 1241 | } else if used_fallthroughs.contains(&block_id) { |
| 1242 | blocks.insert( |
| 1243 | block_id, |
| 1244 | BasicBlock { |
| 1245 | kind: block.kind, |
| 1246 | id: block_id, |
| 1247 | instructions: Vec::new(), |
| 1248 | terminal: Terminal::Unreachable { |
| 1249 | id: block.terminal.evaluation_order(), |
| 1250 | loc: block.terminal.loc().copied(), |
| 1251 | }, |
| 1252 | preds: block.preds.clone(), |
| 1253 | phis: Vec::new(), |
| 1254 | }, |
| 1255 | ); |
| 1256 | } |
| 1257 | // otherwise this block is unreachable and is dropped |
| 1258 | } |
| 1259 | |
| 1260 | blocks |
| 1261 | } |
| 1262 | |
| 1263 | /// For each block with a `For` terminal whose update block is not in the |
| 1264 | /// blocks map, set update to None. |
| 1265 | pub fn remove_unreachable_for_updates(hir: &mut HIR) { |
| 1266 | let block_ids: IndexSet<BlockId, FxBuildHasher> = hir.blocks.keys().copied().collect(); |
| 1267 | for block in hir.blocks.values_mut() { |
| 1268 | if let Terminal::For { update, .. } = &mut block.terminal { |
| 1269 | if let Some(update_id) = *update { |
| 1270 | if !block_ids.contains(&update_id) { |
| 1271 | *update = None; |
| 1272 | } |
| 1273 | } |
| 1274 | } |
| 1275 | } |
| 1276 | } |
| 1277 | |
| 1278 | /// For each block with a `DoWhile` terminal whose test block is not in |
| 1279 | /// the blocks map, replace the terminal with a Goto to the loop block. |
| 1280 | pub fn remove_dead_do_while_statements(hir: &mut HIR) { |
| 1281 | let block_ids: IndexSet<BlockId, FxBuildHasher> = hir.blocks.keys().copied().collect(); |
| 1282 | for block in hir.blocks.values_mut() { |
| 1283 | let should_replace = if let Terminal::DoWhile { test, .. } = &block.terminal { |
| 1284 | !block_ids.contains(test) |
| 1285 | } else { |
| 1286 | false |
| 1287 | }; |
| 1288 | if should_replace { |
| 1289 | if let Terminal::DoWhile { |
| 1290 | loop_block, |
| 1291 | id, |
| 1292 | loc, |
| 1293 | .. |
| 1294 | } = std::mem::replace( |
| 1295 | &mut block.terminal, |
| 1296 | Terminal::Unreachable { |
| 1297 | id: EvaluationOrder(0), |
| 1298 | loc: None, |
| 1299 | }, |
| 1300 | ) { |
| 1301 | block.terminal = Terminal::Goto { |
| 1302 | block: loop_block, |
| 1303 | variant: GotoVariant::Break, |
| 1304 | id, |
| 1305 | loc, |
| 1306 | }; |
| 1307 | } |
| 1308 | } |
| 1309 | } |
| 1310 | } |
| 1311 | |
| 1312 | /// For each block with a `Try` terminal whose handler block is not in |
| 1313 | /// the blocks map, replace the terminal with a Goto to the try block. |
| 1314 | /// |
| 1315 | /// Also cleans up the fallthrough block's predecessors if the handler |
| 1316 | /// was the only path to it. |
| 1317 | pub fn remove_unnecessary_try_catch(hir: &mut HIR) { |
| 1318 | let block_ids: IndexSet<BlockId, FxBuildHasher> = hir.blocks.keys().copied().collect(); |
| 1319 | |
| 1320 | // Collect the blocks that need replacement and their associated data |
| 1321 | let replacements: Vec<(BlockId, BlockId, BlockId, BlockId, Option<SourceLocation>)> = hir |
| 1322 | .blocks |
| 1323 | .iter() |
| 1324 | .filter_map(|(&block_id, block)| { |
| 1325 | if let Terminal::Try { |
| 1326 | block: try_block, |
| 1327 | handler, |
| 1328 | fallthrough, |
| 1329 | loc, |
| 1330 | .. |
| 1331 | } = &block.terminal |
| 1332 | { |
| 1333 | if !block_ids.contains(handler) { |
| 1334 | return Some((block_id, *try_block, *handler, *fallthrough, loc.clone())); |
| 1335 | } |
| 1336 | } |
| 1337 | None |
| 1338 | }) |
| 1339 | .collect(); |
| 1340 | |
| 1341 | for (block_id, try_block, handler_id, fallthrough_id, loc) in replacements { |
| 1342 | // Replace the terminal |
| 1343 | if let Some(block) = hir.blocks.get_mut(&block_id) { |
| 1344 | block.terminal = Terminal::Goto { |
| 1345 | block: try_block, |
| 1346 | id: EvaluationOrder(0), |
| 1347 | loc, |
| 1348 | variant: GotoVariant::Break, |
| 1349 | }; |
| 1350 | } |
| 1351 | |
| 1352 | // Clean up fallthrough predecessor info |
| 1353 | if let Some(fallthrough) = hir.blocks.get_mut(&fallthrough_id) { |
| 1354 | if fallthrough.preds.len() == 1 && fallthrough.preds.contains(&handler_id) { |
| 1355 | // The handler was the only predecessor: remove the fallthrough block |
| 1356 | hir.blocks.shift_remove(&fallthrough_id); |
| 1357 | } else { |
| 1358 | fallthrough.preds.shift_remove(&handler_id); |
| 1359 | } |
| 1360 | } |
| 1361 | } |
| 1362 | } |
| 1363 | |
| 1364 | /// Sequentially number all instructions and terminals starting from 1. |
| 1365 | pub fn mark_instruction_ids(hir: &mut HIR, instructions: &mut [Instruction]) { |
| 1366 | let mut order: u32 = 0; |
| 1367 | for block in hir.blocks.values_mut() { |
| 1368 | for &instr_id in &block.instructions { |
| 1369 | order += 1; |
| 1370 | instructions[instr_id.0 as usize].id = EvaluationOrder(order); |
| 1371 | } |
| 1372 | order += 1; |
| 1373 | block.terminal.set_evaluation_order(EvaluationOrder(order)); |
| 1374 | } |
| 1375 | } |
| 1376 | |
| 1377 | /// DFS from entry, for each successor add the predecessor's id to |
| 1378 | /// the successor's preds set. |
| 1379 | /// |
| 1380 | /// Note: This only visits direct successors (via `each_terminal_successor`), |
| 1381 | /// not fallthrough blocks. Fallthrough blocks are reached indirectly via |
| 1382 | /// Goto terminals from within branching blocks, matching the TypeScript |
| 1383 | /// `markPredecessors` behavior. |
| 1384 | pub fn mark_predecessors(hir: &mut HIR) { |
| 1385 | // Clear all preds first |
| 1386 | for block in hir.blocks.values_mut() { |
| 1387 | block.preds.clear(); |
| 1388 | } |
| 1389 | |
| 1390 | let mut visited: IndexSet<BlockId, FxBuildHasher> = IndexSet::default(); |
| 1391 | |
| 1392 | fn visit( |
| 1393 | hir: &mut HIR, |
| 1394 | block_id: BlockId, |
| 1395 | prev_block_id: Option<BlockId>, |
| 1396 | visited: &mut IndexSet<BlockId, FxBuildHasher>, |
| 1397 | ) { |
| 1398 | // Add predecessor |
| 1399 | if let Some(prev_id) = prev_block_id { |
| 1400 | if let Some(block) = hir.blocks.get_mut(&block_id) { |
| 1401 | block.preds.insert(prev_id); |
| 1402 | } else { |
| 1403 | return; |
| 1404 | } |
| 1405 | } |
| 1406 | |
| 1407 | if visited.contains(&block_id) { |
| 1408 | return; |
| 1409 | } |
| 1410 | visited.insert(block_id); |
| 1411 | |
| 1412 | // Get successors before mutating |
| 1413 | let successors = if let Some(block) = hir.blocks.get(&block_id) { |
| 1414 | each_terminal_successor(&block.terminal) |
| 1415 | } else { |
| 1416 | return; |
| 1417 | }; |
| 1418 | |
| 1419 | for successor in successors { |
| 1420 | visit(hir, successor, Some(block_id), visited); |
| 1421 | } |
| 1422 | } |
| 1423 | |
| 1424 | visit(hir, hir.entry, None, &mut visited); |
| 1425 | } |
| 1426 | |
| 1427 | // --------------------------------------------------------------------------- |
| 1428 | // Public helper functions |
| 1429 | // --------------------------------------------------------------------------- |
| 1430 | |
| 1431 | /// Create a temporary Place with a fresh identifier allocated in the arena. |
| 1432 | pub fn create_temporary_place(env: &mut Environment, loc: Option<SourceLocation>) -> Place { |
| 1433 | let id = env.next_identifier_id(); |
| 1434 | // Update the loc on the allocated identifier |
| 1435 | env.identifiers[id.0 as usize].loc = loc; |
| 1436 | Place { |
| 1437 | identifier: id, |
| 1438 | reactive: false, |
| 1439 | effect: Effect::Unknown, |
| 1440 | loc: None, |
| 1441 | } |
| 1442 | } |