crates/hir_def/src/body/lower.rs

   1 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
   2 //! representation.
   3
   4 use std::{mem, sync::Arc};
   5
   6 use either::Either;
   7 use hir_expand::{
   8     ast_id_map::{AstIdMap, FileAstId},
   9     hygiene::Hygiene,
  10     name::{name, AsName, Name},
  11     ExpandError, HirFileId, InFile,
  12 };
  13 use la_arena::Arena;
  14 use profile::Count;
  15 use syntax::{
  16     ast::{
  17         self, ArgListOwner, ArrayExprKind, AstChildren, LiteralKind, LoopBodyOwner, NameOwner,
  18         SlicePatComponents,
  19     },
  20     AstNode, AstPtr, SyntaxNodePtr,
  21 };
  22
  23 use crate::{
  24     adt::StructKind,
  25     body::{Body, BodySourceMap, Expander, LabelSource, PatPtr, SyntheticSyntax},
  26     body::{BodyDiagnostic, ExprSource, PatSource},
  27     builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint},
  28     db::DefDatabase,
  29     expr::{
  30         dummy_expr_id, Array, BindingAnnotation, Expr, ExprId, Label, LabelId, Literal, MatchArm,
  31         MatchGuard, Pat, PatId, RecordFieldPat, RecordLitField, Statement,
  32     },
  33     intern::Interned,
  34     item_scope::BuiltinShadowMode,
  35     path::{GenericArgs, Path},
  36     type_ref::{Mutability, Rawness, TypeRef},
  37     AdtId, BlockLoc, ModuleDefId, UnresolvedMacro,
  38 };
  39
  40 pub struct LowerCtx<'a> {
  41     pub db: &'a dyn DefDatabase,
  42     hygiene: Hygiene,
  43     file_id: Option<HirFileId>,
  44     source_ast_id_map: Option<Arc<AstIdMap>>,
  45 }
  46
  47 impl<'a> LowerCtx<'a> {
  48     pub fn new(db: &'a dyn DefDatabase, file_id: HirFileId) -> Self {
  49         LowerCtx {
  50             db,
  51             hygiene: Hygiene::new(db.upcast(), file_id),
  52             file_id: Some(file_id),
  53             source_ast_id_map: Some(db.ast_id_map(file_id)),
  54         }
  55     }
  56
  57     pub fn with_hygiene(db: &'a dyn DefDatabase, hygiene: &Hygiene) -> Self {
  58         LowerCtx { db, hygiene: hygiene.clone(), file_id: None, source_ast_id_map: None }
  59     }
  60
  61     pub(crate) fn hygiene(&self) -> &Hygiene {
  62         &self.hygiene
  63     }
  64
  65     pub(crate) fn file_id(&self) -> HirFileId {
  66         self.file_id.unwrap()
  67     }
  68
  69     pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
  70         Path::from_src(ast, self)
  71     }
  72
  73     pub(crate) fn ast_id<N: AstNode>(&self, item: &N) -> Option<FileAstId<N>> {
  74         self.source_ast_id_map.as_ref().map(|ast_id_map| ast_id_map.ast_id(item))
  75     }
  76 }
  77
  78 pub(super) fn lower(
  79     db: &dyn DefDatabase,
  80     expander: Expander,
  81     params: Option<ast::ParamList>,
  82     body: Option<ast::Expr>,
  83 ) -> (Body, BodySourceMap) {
  84     ExprCollector {
  85         db,
  86         source_map: BodySourceMap::default(),
  87         body: Body {
  88             exprs: Arena::default(),
  89             pats: Arena::default(),
  90             labels: Arena::default(),
  91             params: Vec::new(),
  92             body_expr: dummy_expr_id(),
  93             block_scopes: Vec::new(),
  94             _c: Count::new(),
  95         },
  96         expander,
  97         statements_in_scope: Vec::new(),
  98     }
  99     .collect(params, body)
 100 }
 101
 102 struct ExprCollector<'a> {
 103     db: &'a dyn DefDatabase,
 104     expander: Expander,
 105     body: Body,
 106     source_map: BodySourceMap,
 107     statements_in_scope: Vec<Statement>,
 108 }
 109
 110 impl ExprCollector<'_> {
 111     fn collect(
 112         mut self,
 113         param_list: Option<ast::ParamList>,
 114         body: Option<ast::Expr>,
 115     ) -> (Body, BodySourceMap) {
 116         if let Some(param_list) = param_list {
 117             if let Some(self_param) = param_list.self_param() {
 118                 let ptr = AstPtr::new(&self_param);
 119                 let param_pat = self.alloc_pat(
 120                     Pat::Bind {
 121                         name: name![self],
 122                         mode: BindingAnnotation::new(
 123                             self_param.mut_token().is_some() && self_param.amp_token().is_none(),
 124                             false,
 125                         ),
 126                         subpat: None,
 127                     },
 128                     Either::Right(ptr),
 129                 );
 130                 self.body.params.push(param_pat);
 131             }
 132
 133             for param in param_list.params() {
 134                 let pat = match param.pat() {
 135                     None => continue,
 136                     Some(pat) => pat,
 137                 };
 138                 let param_pat = self.collect_pat(pat);
 139                 self.body.params.push(param_pat);
 140             }
 141         };
 142
 143         self.body.body_expr = self.collect_expr_opt(body);
 144         (self.body, self.source_map)
 145     }
 146
 147     fn ctx(&self) -> LowerCtx<'_> {
 148         LowerCtx::new(self.db, self.expander.current_file_id)
 149     }
 150
 151     fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
 152         let src = self.expander.to_source(ptr);
 153         let id = self.make_expr(expr, Ok(src.clone()));
 154         self.source_map.expr_map.insert(src, id);
 155         id
 156     }
 157     // desugared exprs don't have ptr, that's wrong and should be fixed
 158     // somehow.
 159     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
 160         self.make_expr(expr, Err(SyntheticSyntax))
 161     }
 162     fn unit(&mut self) -> ExprId {
 163         self.alloc_expr_desugared(Expr::Tuple { exprs: Vec::new() })
 164     }
 165     fn missing_expr(&mut self) -> ExprId {
 166         self.alloc_expr_desugared(Expr::Missing)
 167     }
 168     fn make_expr(&mut self, expr: Expr, src: Result<ExprSource, SyntheticSyntax>) -> ExprId {
 169         let id = self.body.exprs.alloc(expr);
 170         self.source_map.expr_map_back.insert(id, src);
 171         id
 172     }
 173
 174     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
 175         let src = self.expander.to_source(ptr);
 176         let id = self.make_pat(pat, Ok(src.clone()));
 177         self.source_map.pat_map.insert(src, id);
 178         id
 179     }
 180     fn missing_pat(&mut self) -> PatId {
 181         self.make_pat(Pat::Missing, Err(SyntheticSyntax))
 182     }
 183     fn make_pat(&mut self, pat: Pat, src: Result<PatSource, SyntheticSyntax>) -> PatId {
 184         let id = self.body.pats.alloc(pat);
 185         self.source_map.pat_map_back.insert(id, src);
 186         id
 187     }
 188
 189     fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
 190         let src = self.expander.to_source(ptr);
 191         let id = self.make_label(label, src.clone());
 192         self.source_map.label_map.insert(src, id);
 193         id
 194     }
 195     fn make_label(&mut self, label: Label, src: LabelSource) -> LabelId {
 196         let id = self.body.labels.alloc(label);
 197         self.source_map.label_map_back.insert(id, src);
 198         id
 199     }
 200
 201     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
 202         self.maybe_collect_expr(expr).unwrap_or_else(|| self.missing_expr())
 203     }
 204
 205     /// Returns `None` if and only if the expression is `#[cfg]`d out.
 206     fn maybe_collect_expr(&mut self, expr: ast::Expr) -> Option<ExprId> {
 207         let syntax_ptr = AstPtr::new(&expr);
 208         self.check_cfg(&expr)?;
 209
 210         Some(match expr {
 211             ast::Expr::IfExpr(e) => {
 212                 let then_branch = self.collect_block_opt(e.then_branch());
 213
 214                 let else_branch = e.else_branch().map(|b| match b {
 215                     ast::ElseBranch::Block(it) => self.collect_block(it),
 216                     ast::ElseBranch::IfExpr(elif) => {
 217                         let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
 218                         self.collect_expr(expr)
 219                     }
 220                 });
 221
 222                 let condition = match e.condition() {
 223                     None => self.missing_expr(),
 224                     Some(condition) => match condition.pat() {
 225                         None => self.collect_expr_opt(condition.expr()),
 226                         // if let -- desugar to match
 227                         Some(pat) => {
 228                             let pat = self.collect_pat(pat);
 229                             let match_expr = self.collect_expr_opt(condition.expr());
 230                             let placeholder_pat = self.missing_pat();
 231                             let arms = vec![
 232                                 MatchArm { pat, expr: then_branch, guard: None },
 233                                 MatchArm {
 234                                     pat: placeholder_pat,
 235                                     expr: else_branch.unwrap_or_else(|| self.unit()),
 236                                     guard: None,
 237                                 },
 238                             ];
 239                             return Some(
 240                                 self.alloc_expr(Expr::Match { expr: match_expr, arms }, syntax_ptr),
 241                             );
 242                         }
 243                     },
 244                 };
 245
 246                 self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
 247             }
 248             ast::Expr::EffectExpr(e) => match e.effect() {
 249                 ast::Effect::Try(_) => {
 250                     let body = self.collect_block_opt(e.block_expr());
 251                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
 252                 }
 253                 ast::Effect::Unsafe(_) => {
 254                     let body = self.collect_block_opt(e.block_expr());
 255                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
 256                 }
 257                 // FIXME: we need to record these effects somewhere...
 258                 ast::Effect::Label(label) => {
 259                     let label = self.collect_label(label);
 260                     match e.block_expr() {
 261                         Some(block) => {
 262                             let res = self.collect_block(block);
 263                             match &mut self.body.exprs[res] {
 264                                 Expr::Block { label: block_label, .. } => {
 265                                     *block_label = Some(label);
 266                                 }
 267                                 _ => unreachable!(),
 268                             }
 269                             res
 270                         }
 271                         None => self.missing_expr(),
 272                     }
 273                 }
 274                 // FIXME: we need to record these effects somewhere...
 275                 ast::Effect::Async(_) => {
 276                     let body = self.collect_block_opt(e.block_expr());
 277                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
 278                 }
 279                 ast::Effect::Const(_) => {
 280                     let body = self.collect_block_opt(e.block_expr());
 281                     self.alloc_expr(Expr::Const { body }, syntax_ptr)
 282                 }
 283             },
 284             ast::Expr::BlockExpr(e) => self.collect_block(e),
 285             ast::Expr::LoopExpr(e) => {
 286                 let label = e.label().map(|label| self.collect_label(label));
 287                 let body = self.collect_block_opt(e.loop_body());
 288                 self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
 289             }
 290             ast::Expr::WhileExpr(e) => {
 291                 let label = e.label().map(|label| self.collect_label(label));
 292                 let body = self.collect_block_opt(e.loop_body());
 293
 294                 let condition = match e.condition() {
 295                     None => self.missing_expr(),
 296                     Some(condition) => match condition.pat() {
 297                         None => self.collect_expr_opt(condition.expr()),
 298                         // if let -- desugar to match
 299                         Some(pat) => {
 300                             cov_mark::hit!(infer_resolve_while_let);
 301                             let pat = self.collect_pat(pat);
 302                             let match_expr = self.collect_expr_opt(condition.expr());
 303                             let placeholder_pat = self.missing_pat();
 304                             let break_ =
 305                                 self.alloc_expr_desugared(Expr::Break { expr: None, label: None });
 306                             let arms = vec![
 307                                 MatchArm { pat, expr: body, guard: None },
 308                                 MatchArm { pat: placeholder_pat, expr: break_, guard: None },
 309                             ];
 310                             let match_expr =
 311                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
 312                             return Some(
 313                                 self.alloc_expr(Expr::Loop { body: match_expr, label }, syntax_ptr),
 314                             );
 315                         }
 316                     },
 317                 };
 318
 319                 self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
 320             }
 321             ast::Expr::ForExpr(e) => {
 322                 let label = e.label().map(|label| self.collect_label(label));
 323                 let iterable = self.collect_expr_opt(e.iterable());
 324                 let pat = self.collect_pat_opt(e.pat());
 325                 let body = self.collect_block_opt(e.loop_body());
 326                 self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
 327             }
 328             ast::Expr::CallExpr(e) => {
 329                 let callee = self.collect_expr_opt(e.expr());
 330                 let args = if let Some(arg_list) = e.arg_list() {
 331                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 332                 } else {
 333                     Vec::new()
 334                 };
 335                 self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
 336             }
 337             ast::Expr::MethodCallExpr(e) => {
 338                 let receiver = self.collect_expr_opt(e.receiver());
 339                 let args = if let Some(arg_list) = e.arg_list() {
 340                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 341                 } else {
 342                     Vec::new()
 343                 };
 344                 let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 345                 let generic_args = e
 346                     .generic_arg_list()
 347                     .and_then(|it| GenericArgs::from_ast(&self.ctx(), it))
 348                     .map(Box::new);
 349                 self.alloc_expr(
 350                     Expr::MethodCall { receiver, method_name, args, generic_args },
 351                     syntax_ptr,
 352                 )
 353             }
 354             ast::Expr::MatchExpr(e) => {
 355                 let expr = self.collect_expr_opt(e.expr());
 356                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
 357                     match_arm_list
 358                         .arms()
 359                         .filter_map(|arm| {
 360                             self.check_cfg(&arm).map(|()| MatchArm {
 361                                 pat: self.collect_pat_opt(arm.pat()),
 362                                 expr: self.collect_expr_opt(arm.expr()),
 363                                 guard: arm.guard().map(|guard| match guard.pat() {
 364                                     Some(pat) => MatchGuard::IfLet {
 365                                         pat: self.collect_pat(pat),
 366                                         expr: self.collect_expr_opt(guard.expr()),
 367                                     },
 368                                     None => {
 369                                         MatchGuard::If { expr: self.collect_expr_opt(guard.expr()) }
 370                                     }
 371                                 }),
 372                             })
 373                         })
 374                         .collect()
 375                 } else {
 376                     Vec::new()
 377                 };
 378                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
 379             }
 380             ast::Expr::PathExpr(e) => {
 381                 let path = e
 382                     .path()
 383                     .and_then(|path| self.expander.parse_path(self.db, path))
 384                     .map(Expr::Path)
 385                     .unwrap_or(Expr::Missing);
 386                 self.alloc_expr(path, syntax_ptr)
 387             }
 388             ast::Expr::ContinueExpr(e) => self.alloc_expr(
 389                 Expr::Continue { label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 390                 syntax_ptr,
 391             ),
 392             ast::Expr::BreakExpr(e) => {
 393                 let expr = e.expr().map(|e| self.collect_expr(e));
 394                 self.alloc_expr(
 395                     Expr::Break { expr, label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 396                     syntax_ptr,
 397                 )
 398             }
 399             ast::Expr::ParenExpr(e) => {
 400                 let inner = self.collect_expr_opt(e.expr());
 401                 // make the paren expr point to the inner expression as well
 402                 let src = self.expander.to_source(syntax_ptr);
 403                 self.source_map.expr_map.insert(src, inner);
 404                 inner
 405             }
 406             ast::Expr::ReturnExpr(e) => {
 407                 let expr = e.expr().map(|e| self.collect_expr(e));
 408                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
 409             }
 410             ast::Expr::YieldExpr(e) => {
 411                 let expr = e.expr().map(|e| self.collect_expr(e));
 412                 self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
 413             }
 414             ast::Expr::RecordExpr(e) => {
 415                 let path =
 416                     e.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 417                 let record_lit = if let Some(nfl) = e.record_expr_field_list() {
 418                     let fields = nfl
 419                         .fields()
 420                         .filter_map(|field| {
 421                             self.check_cfg(&field)?;
 422
 423                             let name = field.field_name()?.as_name();
 424
 425                             let expr = match field.expr() {
 426                                 Some(e) => self.collect_expr(e),
 427                                 None => self.missing_expr(),
 428                             };
 429                             let src = self.expander.to_source(AstPtr::new(&field));
 430                             self.source_map.field_map.insert(src.clone(), expr);
 431                             self.source_map.field_map_back.insert(expr, src);
 432                             Some(RecordLitField { name, expr })
 433                         })
 434                         .collect();
 435                     let spread = nfl.spread().map(|s| self.collect_expr(s));
 436                     Expr::RecordLit { path, fields, spread }
 437                 } else {
 438                     Expr::RecordLit { path, fields: Vec::new(), spread: None }
 439                 };
 440
 441                 self.alloc_expr(record_lit, syntax_ptr)
 442             }
 443             ast::Expr::FieldExpr(e) => {
 444                 let expr = self.collect_expr_opt(e.expr());
 445                 let name = match e.field_access() {
 446                     Some(kind) => kind.as_name(),
 447                     _ => Name::missing(),
 448                 };
 449                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
 450             }
 451             ast::Expr::AwaitExpr(e) => {
 452                 let expr = self.collect_expr_opt(e.expr());
 453                 self.alloc_expr(Expr::Await { expr }, syntax_ptr)
 454             }
 455             ast::Expr::TryExpr(e) => {
 456                 let expr = self.collect_expr_opt(e.expr());
 457                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
 458             }
 459             ast::Expr::CastExpr(e) => {
 460                 let expr = self.collect_expr_opt(e.expr());
 461                 let type_ref = Interned::new(TypeRef::from_ast_opt(&self.ctx(), e.ty()));
 462                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
 463             }
 464             ast::Expr::RefExpr(e) => {
 465                 let expr = self.collect_expr_opt(e.expr());
 466                 let raw_tok = e.raw_token().is_some();
 467                 let mutability = if raw_tok {
 468                     if e.mut_token().is_some() {
 469                         Mutability::Mut
 470                     } else if e.const_token().is_some() {
 471                         Mutability::Shared
 472                     } else {
 473                         unreachable!("parser only remaps to raw_token() if matching mutability token follows")
 474                     }
 475                 } else {
 476                     Mutability::from_mutable(e.mut_token().is_some())
 477                 };
 478                 let rawness = Rawness::from_raw(raw_tok);
 479                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
 480             }
 481             ast::Expr::PrefixExpr(e) => {
 482                 let expr = self.collect_expr_opt(e.expr());
 483                 if let Some(op) = e.op_kind() {
 484                     self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr)
 485                 } else {
 486                     self.alloc_expr(Expr::Missing, syntax_ptr)
 487                 }
 488             }
 489             ast::Expr::ClosureExpr(e) => {
 490                 let mut args = Vec::new();
 491                 let mut arg_types = Vec::new();
 492                 if let Some(pl) = e.param_list() {
 493                     for param in pl.params() {
 494                         let pat = self.collect_pat_opt(param.pat());
 495                         let type_ref =
 496                             param.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 497                         args.push(pat);
 498                         arg_types.push(type_ref);
 499                     }
 500                 }
 501                 let ret_type = e
 502                     .ret_type()
 503                     .and_then(|r| r.ty())
 504                     .map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 505                 let body = self.collect_expr_opt(e.body());
 506                 self.alloc_expr(Expr::Lambda { args, arg_types, ret_type, body }, syntax_ptr)
 507             }
 508             ast::Expr::BinExpr(e) => {
 509                 let lhs = self.collect_expr_opt(e.lhs());
 510                 let rhs = self.collect_expr_opt(e.rhs());
 511                 let op = e.op_kind();
 512                 self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
 513             }
 514             ast::Expr::TupleExpr(e) => {
 515                 let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect();
 516                 self.alloc_expr(Expr::Tuple { exprs }, syntax_ptr)
 517             }
 518             ast::Expr::BoxExpr(e) => {
 519                 let expr = self.collect_expr_opt(e.expr());
 520                 self.alloc_expr(Expr::Box { expr }, syntax_ptr)
 521             }
 522
 523             ast::Expr::ArrayExpr(e) => {
 524                 let kind = e.kind();
 525
 526                 match kind {
 527                     ArrayExprKind::ElementList(e) => {
 528                         let exprs = e.map(|expr| self.collect_expr(expr)).collect();
 529                         self.alloc_expr(Expr::Array(Array::ElementList(exprs)), syntax_ptr)
 530                     }
 531                     ArrayExprKind::Repeat { initializer, repeat } => {
 532                         let initializer = self.collect_expr_opt(initializer);
 533                         let repeat = self.collect_expr_opt(repeat);
 534                         self.alloc_expr(
 535                             Expr::Array(Array::Repeat { initializer, repeat }),
 536                             syntax_ptr,
 537                         )
 538                     }
 539                 }
 540             }
 541
 542             ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
 543             ast::Expr::IndexExpr(e) => {
 544                 let base = self.collect_expr_opt(e.base());
 545                 let index = self.collect_expr_opt(e.index());
 546                 self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
 547             }
 548             ast::Expr::RangeExpr(e) => {
 549                 let lhs = e.start().map(|lhs| self.collect_expr(lhs));
 550                 let rhs = e.end().map(|rhs| self.collect_expr(rhs));
 551                 match e.op_kind() {
 552                     Some(range_type) => {
 553                         self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
 554                     }
 555                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 556                 }
 557             }
 558             ast::Expr::MacroCall(e) => {
 559                 let macro_ptr = AstPtr::new(&e);
 560                 let mut ids = vec![];
 561                 self.collect_macro_call(e, macro_ptr, |this, expansion| {
 562                     ids.push(match expansion {
 563                         Some(it) => this.collect_expr(it),
 564                         None => this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
 565                     })
 566                 });
 567                 ids[0]
 568             }
 569             ast::Expr::MacroStmts(e) => {
 570                 e.statements().for_each(|s| self.collect_stmt(s));
 571                 let tail = e
 572                     .expr()
 573                     .map(|e| self.collect_expr(e))
 574                     .unwrap_or_else(|| self.alloc_expr(Expr::Missing, syntax_ptr.clone()));
 575
 576                 self.alloc_expr(Expr::MacroStmts { tail }, syntax_ptr)
 577             }
 578         })
 579     }
 580
 581     fn collect_macro_call<F: FnMut(&mut Self, Option<T>), T: ast::AstNode>(
 582         &mut self,
 583         e: ast::MacroCall,
 584         syntax_ptr: AstPtr<ast::MacroCall>,
 585         mut collector: F,
 586     ) {
 587         // File containing the macro call. Expansion errors will be attached here.
 588         let outer_file = self.expander.current_file_id;
 589
 590         let macro_call = self.expander.to_source(AstPtr::new(&e));
 591         let res = self.expander.enter_expand(self.db, e);
 592
 593         let res = match res {
 594             Ok(res) => res,
 595             Err(UnresolvedMacro { path }) => {
 596                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall {
 597                     node: InFile::new(outer_file, syntax_ptr),
 598                     path,
 599                 });
 600                 collector(self, None);
 601                 return;
 602             }
 603         };
 604
 605         match &res.err {
 606             Some(ExpandError::UnresolvedProcMacro) => {
 607                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro {
 608                     node: InFile::new(outer_file, syntax_ptr),
 609                 });
 610             }
 611             Some(err) => {
 612                 self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
 613                     node: InFile::new(outer_file, syntax_ptr),
 614                     message: err.to_string(),
 615                 });
 616             }
 617             None => {}
 618         }
 619
 620         match res.value {
 621             Some((mark, expansion)) => {
 622                 self.source_map.expansions.insert(macro_call, self.expander.current_file_id);
 623
 624                 let id = collector(self, Some(expansion));
 625                 self.expander.exit(self.db, mark);
 626                 id
 627             }
 628             None => collector(self, None),
 629         }
 630     }
 631
 632     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 633         if let Some(expr) = expr {
 634             self.collect_expr(expr)
 635         } else {
 636             self.missing_expr()
 637         }
 638     }
 639
 640     fn collect_stmt(&mut self, s: ast::Stmt) {
 641         match s {
 642             ast::Stmt::LetStmt(stmt) => {
 643                 if self.check_cfg(&stmt).is_none() {
 644                     return;
 645                 }
 646                 let pat = self.collect_pat_opt(stmt.pat());
 647                 let type_ref =
 648                     stmt.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 649                 let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 650                 self.statements_in_scope.push(Statement::Let { pat, type_ref, initializer });
 651             }
 652             ast::Stmt::ExprStmt(stmt) => {
 653                 if let Some(expr) = stmt.expr() {
 654                     if self.check_cfg(&expr).is_none() {
 655                         return;
 656                     }
 657                 }
 658                 let has_semi = stmt.semicolon_token().is_some();
 659                 // Note that macro could be expended to multiple statements
 660                 if let Some(ast::Expr::MacroCall(m)) = stmt.expr() {
 661                     let macro_ptr = AstPtr::new(&m);
 662                     let syntax_ptr = AstPtr::new(&stmt.expr().unwrap());
 663
 664                     self.collect_macro_call(m, macro_ptr, |this, expansion| match expansion {
 665                         Some(expansion) => {
 666                             let statements: ast::MacroStmts = expansion;
 667
 668                             statements.statements().for_each(|stmt| this.collect_stmt(stmt));
 669                             if let Some(expr) = statements.expr() {
 670                                 let expr = this.collect_expr(expr);
 671                                 this.statements_in_scope.push(Statement::Expr { expr, has_semi });
 672                             }
 673                         }
 674                         None => {
 675                             let expr = this.alloc_expr(Expr::Missing, syntax_ptr.clone());
 676                             this.statements_in_scope.push(Statement::Expr { expr, has_semi });
 677                         }
 678                     });
 679                 } else {
 680                     let expr = self.collect_expr_opt(stmt.expr());
 681                     self.statements_in_scope.push(Statement::Expr { expr, has_semi });
 682                 }
 683             }
 684             ast::Stmt::Item(item) => {
 685                 self.check_cfg(&item);
 686             }
 687         }
 688     }
 689
 690     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 691         let ast_id = self.expander.ast_id(&block);
 692         let block_loc =
 693             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
 694         let block_id = self.db.intern_block(block_loc);
 695
 696         let (module, def_map) = match self.db.block_def_map(block_id) {
 697             Some(def_map) => {
 698                 self.body.block_scopes.push(block_id);
 699                 (def_map.root(), def_map)
 700             }
 701             None => (self.expander.module, self.expander.def_map.clone()),
 702         };
 703         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 704         let prev_local_module = mem::replace(&mut self.expander.module, module);
 705         let prev_statements = std::mem::take(&mut self.statements_in_scope);
 706
 707         block.statements().for_each(|s| self.collect_stmt(s));
 708         block.tail_expr().and_then(|e| {
 709             let expr = self.maybe_collect_expr(e)?;
 710             self.statements_in_scope.push(Statement::Expr { expr, has_semi: false });
 711             Some(())
 712         });
 713
 714         let mut tail = None;
 715         if let Some(Statement::Expr { expr, has_semi: false }) = self.statements_in_scope.last() {
 716             tail = Some(*expr);
 717             self.statements_in_scope.pop();
 718         }
 719         let tail = tail;
 720         let statements = std::mem::replace(&mut self.statements_in_scope, prev_statements);
 721         let syntax_node_ptr = AstPtr::new(&block.into());
 722         let expr_id = self.alloc_expr(
 723             Expr::Block { id: block_id, statements, tail, label: None },
 724             syntax_node_ptr,
 725         );
 726
 727         self.expander.def_map = prev_def_map;
 728         self.expander.module = prev_local_module;
 729         expr_id
 730     }
 731
 732     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 733         if let Some(block) = expr {
 734             self.collect_block(block)
 735         } else {
 736             self.missing_expr()
 737         }
 738     }
 739
 740     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 741         let label = Label {
 742             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 743         };
 744         self.alloc_label(label, AstPtr::new(&ast_label))
 745     }
 746
 747     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 748         let pattern = match &pat {
 749             ast::Pat::IdentPat(bp) => {
 750                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 751                 let annotation =
 752                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 753                 let subpat = bp.pat().map(|subpat| self.collect_pat(subpat));
 754                 if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 755                     // This could also be a single-segment path pattern. To
 756                     // decide that, we need to try resolving the name.
 757                     let (resolved, _) = self.expander.def_map.resolve_path(
 758                         self.db,
 759                         self.expander.module,
 760                         &name.clone().into(),
 761                         BuiltinShadowMode::Other,
 762                     );
 763                     match resolved.take_values() {
 764                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 765                         Some(ModuleDefId::EnumVariantId(_)) => {
 766                             // this is only really valid for unit variants, but
 767                             // shadowing other enum variants with a pattern is
 768                             // an error anyway
 769                             Pat::Path(name.into())
 770                         }
 771                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 772                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 773                         {
 774                             // Funnily enough, record structs *can* be shadowed
 775                             // by pattern bindings (but unit or tuple structs
 776                             // can't).
 777                             Pat::Path(name.into())
 778                         }
 779                         // shadowing statics is an error as well, so we just ignore that case here
 780                         _ => Pat::Bind { name, mode: annotation, subpat },
 781                     }
 782                 } else {
 783                     Pat::Bind { name, mode: annotation, subpat }
 784                 }
 785             }
 786             ast::Pat::TupleStructPat(p) => {
 787                 let path =
 788                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 789                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 790                 Pat::TupleStruct { path, args, ellipsis }
 791             }
 792             ast::Pat::RefPat(p) => {
 793                 let pat = self.collect_pat_opt(p.pat());
 794                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 795                 Pat::Ref { pat, mutability }
 796             }
 797             ast::Pat::PathPat(p) => {
 798                 let path =
 799                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 800                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 801             }
 802             ast::Pat::OrPat(p) => {
 803                 let pats = p.pats().map(|p| self.collect_pat(p)).collect();
 804                 Pat::Or(pats)
 805             }
 806             ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat()),
 807             ast::Pat::TuplePat(p) => {
 808                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 809                 Pat::Tuple { args, ellipsis }
 810             }
 811             ast::Pat::WildcardPat(_) => Pat::Wild,
 812             ast::Pat::RecordPat(p) => {
 813                 let path =
 814                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 815                 let args: Vec<_> = p
 816                     .record_pat_field_list()
 817                     .expect("every struct should have a field list")
 818                     .fields()
 819                     .filter_map(|f| {
 820                         let ast_pat = f.pat()?;
 821                         let pat = self.collect_pat(ast_pat);
 822                         let name = f.field_name()?.as_name();
 823                         Some(RecordFieldPat { name, pat })
 824                     })
 825                     .collect();
 826
 827                 let ellipsis = p
 828                     .record_pat_field_list()
 829                     .expect("every struct should have a field list")
 830                     .dotdot_token()
 831                     .is_some();
 832
 833                 Pat::Record { path, args, ellipsis }
 834             }
 835             ast::Pat::SlicePat(p) => {
 836                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 837
 838                 // FIXME properly handle `RestPat`
 839                 Pat::Slice {
 840                     prefix: prefix.into_iter().map(|p| self.collect_pat(p)).collect(),
 841                     slice: slice.map(|p| self.collect_pat(p)),
 842                     suffix: suffix.into_iter().map(|p| self.collect_pat(p)).collect(),
 843                 }
 844             }
 845             ast::Pat::LiteralPat(lit) => {
 846                 if let Some(ast_lit) = lit.literal() {
 847                     let expr = Expr::Literal(ast_lit.kind().into());
 848                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 849                     let expr_id = self.alloc_expr(expr, expr_ptr);
 850                     Pat::Lit(expr_id)
 851                 } else {
 852                     Pat::Missing
 853                 }
 854             }
 855             ast::Pat::RestPat(_) => {
 856                 // `RestPat` requires special handling and should not be mapped
 857                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 858                 // when `RestPat` is mapped to `Pat`, which can easily happen
 859                 // when the source code being analyzed has a malformed pattern
 860                 // which includes `..` in a place where it isn't valid.
 861
 862                 Pat::Missing
 863             }
 864             ast::Pat::BoxPat(boxpat) => {
 865                 let inner = self.collect_pat_opt(boxpat.pat());
 866                 Pat::Box { inner }
 867             }
 868             ast::Pat::ConstBlockPat(const_block_pat) => {
 869                 if let Some(expr) = const_block_pat.block_expr() {
 870                     let expr_id = self.collect_block(expr);
 871                     Pat::ConstBlock(expr_id)
 872                 } else {
 873                     Pat::Missing
 874                 }
 875             }
 876             ast::Pat::MacroPat(mac) => match mac.macro_call() {
 877                 Some(call) => {
 878                     let macro_ptr = AstPtr::new(&call);
 879                     let mut pat = None;
 880                     self.collect_macro_call(call, macro_ptr, |this, expanded_pat| {
 881                         pat = Some(this.collect_pat_opt(expanded_pat));
 882                     });
 883
 884                     match pat {
 885                         Some(pat) => return pat,
 886                         None => Pat::Missing,
 887                     }
 888                 }
 889                 None => Pat::Missing,
 890             },
 891             // FIXME: implement
 892             ast::Pat::RangePat(_) => Pat::Missing,
 893         };
 894         let ptr = AstPtr::new(&pat);
 895         self.alloc_pat(pattern, Either::Left(ptr))
 896     }
 897
 898     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 899         if let Some(pat) = pat {
 900             self.collect_pat(pat)
 901         } else {
 902             self.missing_pat()
 903         }
 904     }
 905
 906     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Vec<PatId>, Option<usize>) {
 907         // Find the location of the `..`, if there is one. Note that we do not
 908         // consider the possibility of there being multiple `..` here.
 909         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 910         // We want to skip the `..` pattern here, since we account for it above.
 911         let args = args
 912             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 913             .map(|p| self.collect_pat(p))
 914             .collect();
 915
 916         (args, ellipsis)
 917     }
 918
 919     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 920     /// not.
 921     fn check_cfg(&mut self, owner: &dyn ast::AttrsOwner) -> Option<()> {
 922         match self.expander.parse_attrs(self.db, owner).cfg() {
 923             Some(cfg) => {
 924                 if self.expander.cfg_options().check(&cfg) != Some(false) {
 925                     return Some(());
 926                 }
 927
 928                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode {
 929                     node: InFile::new(
 930                         self.expander.current_file_id,
 931                         SyntaxNodePtr::new(owner.syntax()),
 932                     ),
 933                     cfg,
 934                     opts: self.expander.cfg_options().clone(),
 935                 });
 936
 937                 None
 938             }
 939             None => Some(()),
 940         }
 941     }
 942 }
 943
 944 impl From<ast::LiteralKind> for Literal {
 945     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
 946         match ast_lit_kind {
 947             // FIXME: these should have actual values filled in, but unsure on perf impact
 948             LiteralKind::IntNumber(lit) => {
 949                 if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
 950                     Literal::Float(Default::default(), builtin)
 951                 } else if let builtin @ Some(_) =
 952                     lit.suffix().and_then(|it| BuiltinInt::from_suffix(it))
 953                 {
 954                     Literal::Int(lit.value().unwrap_or(0) as i128, builtin)
 955                 } else {
 956                     let builtin = lit.suffix().and_then(|it| BuiltinUint::from_suffix(it));
 957                     Literal::Uint(lit.value().unwrap_or(0), builtin)
 958                 }
 959             }
 960             LiteralKind::FloatNumber(lit) => {
 961                 let ty = lit.suffix().and_then(|it| BuiltinFloat::from_suffix(it));
 962                 Literal::Float(Default::default(), ty)
 963             }
 964             LiteralKind::ByteString(bs) => {
 965                 let text = bs.value().map(Vec::from).unwrap_or_else(Default::default);
 966                 Literal::ByteString(text)
 967             }
 968             LiteralKind::String(_) => Literal::String(Default::default()),
 969             LiteralKind::Byte => Literal::Uint(Default::default(), Some(BuiltinUint::U8)),
 970             LiteralKind::Bool(val) => Literal::Bool(val),
 971             LiteralKind::Char => Literal::Char(Default::default()),
 972         }
 973     }
 974 }