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, ArrayExprKind, AstChildren, HasArgList, HasLoopBody, HasName, LiteralKind,
  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::BlockExpr(e) => match e.modifier() {
 249                 Some(ast::BlockModifier::Try(_)) => {
 250                     let body = self.collect_block(e);
 251                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
 252                 }
 253                 Some(ast::BlockModifier::Unsafe(_)) => {
 254                     let body = self.collect_block(e);
 255                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
 256                 }
 257                 // FIXME: we need to record these effects somewhere...
 258                 Some(ast::BlockModifier::Label(label)) => {
 259                     let label = self.collect_label(label);
 260                     let res = self.collect_block(e);
 261                     match &mut self.body.exprs[res] {
 262                         Expr::Block { label: block_label, .. } => {
 263                             *block_label = Some(label);
 264                         }
 265                         _ => unreachable!(),
 266                     }
 267                     res
 268                 }
 269                 Some(ast::BlockModifier::Async(_)) => {
 270                     let body = self.collect_block(e);
 271                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
 272                 }
 273                 Some(ast::BlockModifier::Const(_)) => {
 274                     let body = self.collect_block(e);
 275                     self.alloc_expr(Expr::Const { body }, syntax_ptr)
 276                 }
 277                 None => self.collect_block(e),
 278             },
 279             ast::Expr::LoopExpr(e) => {
 280                 let label = e.label().map(|label| self.collect_label(label));
 281                 let body = self.collect_block_opt(e.loop_body());
 282                 self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
 283             }
 284             ast::Expr::WhileExpr(e) => {
 285                 let label = e.label().map(|label| self.collect_label(label));
 286                 let body = self.collect_block_opt(e.loop_body());
 287
 288                 let condition = match e.condition() {
 289                     None => self.missing_expr(),
 290                     Some(condition) => match condition.pat() {
 291                         None => self.collect_expr_opt(condition.expr()),
 292                         // if let -- desugar to match
 293                         Some(pat) => {
 294                             cov_mark::hit!(infer_resolve_while_let);
 295                             let pat = self.collect_pat(pat);
 296                             let match_expr = self.collect_expr_opt(condition.expr());
 297                             let placeholder_pat = self.missing_pat();
 298                             let break_ =
 299                                 self.alloc_expr_desugared(Expr::Break { expr: None, label: None });
 300                             let arms = vec![
 301                                 MatchArm { pat, expr: body, guard: None },
 302                                 MatchArm { pat: placeholder_pat, expr: break_, guard: None },
 303                             ];
 304                             let match_expr =
 305                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
 306                             return Some(
 307                                 self.alloc_expr(Expr::Loop { body: match_expr, label }, syntax_ptr),
 308                             );
 309                         }
 310                     },
 311                 };
 312
 313                 self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
 314             }
 315             ast::Expr::ForExpr(e) => {
 316                 let label = e.label().map(|label| self.collect_label(label));
 317                 let iterable = self.collect_expr_opt(e.iterable());
 318                 let pat = self.collect_pat_opt(e.pat());
 319                 let body = self.collect_block_opt(e.loop_body());
 320                 self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
 321             }
 322             ast::Expr::CallExpr(e) => {
 323                 let callee = self.collect_expr_opt(e.expr());
 324                 let args = if let Some(arg_list) = e.arg_list() {
 325                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 326                 } else {
 327                     Vec::new()
 328                 };
 329                 self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
 330             }
 331             ast::Expr::MethodCallExpr(e) => {
 332                 let receiver = self.collect_expr_opt(e.receiver());
 333                 let args = if let Some(arg_list) = e.arg_list() {
 334                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 335                 } else {
 336                     Vec::new()
 337                 };
 338                 let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 339                 let generic_args = e
 340                     .generic_arg_list()
 341                     .and_then(|it| GenericArgs::from_ast(&self.ctx(), it))
 342                     .map(Box::new);
 343                 self.alloc_expr(
 344                     Expr::MethodCall { receiver, method_name, args, generic_args },
 345                     syntax_ptr,
 346                 )
 347             }
 348             ast::Expr::MatchExpr(e) => {
 349                 let expr = self.collect_expr_opt(e.expr());
 350                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
 351                     match_arm_list
 352                         .arms()
 353                         .filter_map(|arm| {
 354                             self.check_cfg(&arm).map(|()| MatchArm {
 355                                 pat: self.collect_pat_opt(arm.pat()),
 356                                 expr: self.collect_expr_opt(arm.expr()),
 357                                 guard: arm.guard().map(|guard| match guard.pat() {
 358                                     Some(pat) => MatchGuard::IfLet {
 359                                         pat: self.collect_pat(pat),
 360                                         expr: self.collect_expr_opt(guard.expr()),
 361                                     },
 362                                     None => {
 363                                         MatchGuard::If { expr: self.collect_expr_opt(guard.expr()) }
 364                                     }
 365                                 }),
 366                             })
 367                         })
 368                         .collect()
 369                 } else {
 370                     Vec::new()
 371                 };
 372                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
 373             }
 374             ast::Expr::PathExpr(e) => {
 375                 let path = e
 376                     .path()
 377                     .and_then(|path| self.expander.parse_path(self.db, path))
 378                     .map(Expr::Path)
 379                     .unwrap_or(Expr::Missing);
 380                 self.alloc_expr(path, syntax_ptr)
 381             }
 382             ast::Expr::ContinueExpr(e) => self.alloc_expr(
 383                 Expr::Continue { label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 384                 syntax_ptr,
 385             ),
 386             ast::Expr::BreakExpr(e) => {
 387                 let expr = e.expr().map(|e| self.collect_expr(e));
 388                 self.alloc_expr(
 389                     Expr::Break { expr, label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 390                     syntax_ptr,
 391                 )
 392             }
 393             ast::Expr::ParenExpr(e) => {
 394                 let inner = self.collect_expr_opt(e.expr());
 395                 // make the paren expr point to the inner expression as well
 396                 let src = self.expander.to_source(syntax_ptr);
 397                 self.source_map.expr_map.insert(src, inner);
 398                 inner
 399             }
 400             ast::Expr::ReturnExpr(e) => {
 401                 let expr = e.expr().map(|e| self.collect_expr(e));
 402                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
 403             }
 404             ast::Expr::YieldExpr(e) => {
 405                 let expr = e.expr().map(|e| self.collect_expr(e));
 406                 self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
 407             }
 408             ast::Expr::RecordExpr(e) => {
 409                 let path =
 410                     e.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 411                 let record_lit = if let Some(nfl) = e.record_expr_field_list() {
 412                     let fields = nfl
 413                         .fields()
 414                         .filter_map(|field| {
 415                             self.check_cfg(&field)?;
 416
 417                             let name = field.field_name()?.as_name();
 418
 419                             let expr = match field.expr() {
 420                                 Some(e) => self.collect_expr(e),
 421                                 None => self.missing_expr(),
 422                             };
 423                             let src = self.expander.to_source(AstPtr::new(&field));
 424                             self.source_map.field_map.insert(src.clone(), expr);
 425                             self.source_map.field_map_back.insert(expr, src);
 426                             Some(RecordLitField { name, expr })
 427                         })
 428                         .collect();
 429                     let spread = nfl.spread().map(|s| self.collect_expr(s));
 430                     Expr::RecordLit { path, fields, spread }
 431                 } else {
 432                     Expr::RecordLit { path, fields: Vec::new(), spread: None }
 433                 };
 434
 435                 self.alloc_expr(record_lit, syntax_ptr)
 436             }
 437             ast::Expr::FieldExpr(e) => {
 438                 let expr = self.collect_expr_opt(e.expr());
 439                 let name = match e.field_access() {
 440                     Some(kind) => kind.as_name(),
 441                     _ => Name::missing(),
 442                 };
 443                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
 444             }
 445             ast::Expr::AwaitExpr(e) => {
 446                 let expr = self.collect_expr_opt(e.expr());
 447                 self.alloc_expr(Expr::Await { expr }, syntax_ptr)
 448             }
 449             ast::Expr::TryExpr(e) => {
 450                 let expr = self.collect_expr_opt(e.expr());
 451                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
 452             }
 453             ast::Expr::CastExpr(e) => {
 454                 let expr = self.collect_expr_opt(e.expr());
 455                 let type_ref = Interned::new(TypeRef::from_ast_opt(&self.ctx(), e.ty()));
 456                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
 457             }
 458             ast::Expr::RefExpr(e) => {
 459                 let expr = self.collect_expr_opt(e.expr());
 460                 let raw_tok = e.raw_token().is_some();
 461                 let mutability = if raw_tok {
 462                     if e.mut_token().is_some() {
 463                         Mutability::Mut
 464                     } else if e.const_token().is_some() {
 465                         Mutability::Shared
 466                     } else {
 467                         unreachable!("parser only remaps to raw_token() if matching mutability token follows")
 468                     }
 469                 } else {
 470                     Mutability::from_mutable(e.mut_token().is_some())
 471                 };
 472                 let rawness = Rawness::from_raw(raw_tok);
 473                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
 474             }
 475             ast::Expr::PrefixExpr(e) => {
 476                 let expr = self.collect_expr_opt(e.expr());
 477                 match e.op_kind() {
 478                     Some(op) => self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr),
 479                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 480                 }
 481             }
 482             ast::Expr::ClosureExpr(e) => {
 483                 let mut args = Vec::new();
 484                 let mut arg_types = Vec::new();
 485                 if let Some(pl) = e.param_list() {
 486                     for param in pl.params() {
 487                         let pat = self.collect_pat_opt(param.pat());
 488                         let type_ref =
 489                             param.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 490                         args.push(pat);
 491                         arg_types.push(type_ref);
 492                     }
 493                 }
 494                 let ret_type = e
 495                     .ret_type()
 496                     .and_then(|r| r.ty())
 497                     .map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 498                 let body = self.collect_expr_opt(e.body());
 499                 self.alloc_expr(Expr::Lambda { args, arg_types, ret_type, body }, syntax_ptr)
 500             }
 501             ast::Expr::BinExpr(e) => {
 502                 let lhs = self.collect_expr_opt(e.lhs());
 503                 let rhs = self.collect_expr_opt(e.rhs());
 504                 let op = e.op_kind();
 505                 self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
 506             }
 507             ast::Expr::TupleExpr(e) => {
 508                 let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect();
 509                 self.alloc_expr(Expr::Tuple { exprs }, syntax_ptr)
 510             }
 511             ast::Expr::BoxExpr(e) => {
 512                 let expr = self.collect_expr_opt(e.expr());
 513                 self.alloc_expr(Expr::Box { expr }, syntax_ptr)
 514             }
 515
 516             ast::Expr::ArrayExpr(e) => {
 517                 let kind = e.kind();
 518
 519                 match kind {
 520                     ArrayExprKind::ElementList(e) => {
 521                         let exprs = e.map(|expr| self.collect_expr(expr)).collect();
 522                         self.alloc_expr(Expr::Array(Array::ElementList(exprs)), syntax_ptr)
 523                     }
 524                     ArrayExprKind::Repeat { initializer, repeat } => {
 525                         let initializer = self.collect_expr_opt(initializer);
 526                         let repeat = self.collect_expr_opt(repeat);
 527                         self.alloc_expr(
 528                             Expr::Array(Array::Repeat { initializer, repeat }),
 529                             syntax_ptr,
 530                         )
 531                     }
 532                 }
 533             }
 534
 535             ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
 536             ast::Expr::IndexExpr(e) => {
 537                 let base = self.collect_expr_opt(e.base());
 538                 let index = self.collect_expr_opt(e.index());
 539                 self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
 540             }
 541             ast::Expr::RangeExpr(e) => {
 542                 let lhs = e.start().map(|lhs| self.collect_expr(lhs));
 543                 let rhs = e.end().map(|rhs| self.collect_expr(rhs));
 544                 match e.op_kind() {
 545                     Some(range_type) => {
 546                         self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
 547                     }
 548                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 549                 }
 550             }
 551             ast::Expr::MacroCall(e) => {
 552                 let macro_ptr = AstPtr::new(&e);
 553                 let mut ids = vec![];
 554                 self.collect_macro_call(e, macro_ptr, |this, expansion| {
 555                     ids.push(match expansion {
 556                         Some(it) => this.collect_expr(it),
 557                         None => this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
 558                     })
 559                 });
 560                 ids[0]
 561             }
 562             ast::Expr::MacroStmts(e) => {
 563                 e.statements().for_each(|s| self.collect_stmt(s));
 564                 let tail = e
 565                     .expr()
 566                     .map(|e| self.collect_expr(e))
 567                     .unwrap_or_else(|| self.alloc_expr(Expr::Missing, syntax_ptr.clone()));
 568
 569                 self.alloc_expr(Expr::MacroStmts { tail }, syntax_ptr)
 570             }
 571         })
 572     }
 573
 574     fn collect_macro_call<F: FnMut(&mut Self, Option<T>), T: ast::AstNode>(
 575         &mut self,
 576         e: ast::MacroCall,
 577         syntax_ptr: AstPtr<ast::MacroCall>,
 578         mut collector: F,
 579     ) {
 580         // File containing the macro call. Expansion errors will be attached here.
 581         let outer_file = self.expander.current_file_id;
 582
 583         let macro_call = self.expander.to_source(AstPtr::new(&e));
 584         let res = self.expander.enter_expand(self.db, e);
 585
 586         let res = match res {
 587             Ok(res) => res,
 588             Err(UnresolvedMacro { path }) => {
 589                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall {
 590                     node: InFile::new(outer_file, syntax_ptr),
 591                     path,
 592                 });
 593                 collector(self, None);
 594                 return;
 595             }
 596         };
 597
 598         match &res.err {
 599             Some(ExpandError::UnresolvedProcMacro) => {
 600                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro {
 601                     node: InFile::new(outer_file, syntax_ptr),
 602                 });
 603             }
 604             Some(err) => {
 605                 self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
 606                     node: InFile::new(outer_file, syntax_ptr),
 607                     message: err.to_string(),
 608                 });
 609             }
 610             None => {}
 611         }
 612
 613         match res.value {
 614             Some((mark, expansion)) => {
 615                 self.source_map.expansions.insert(macro_call, self.expander.current_file_id);
 616
 617                 let id = collector(self, Some(expansion));
 618                 self.expander.exit(self.db, mark);
 619                 id
 620             }
 621             None => collector(self, None),
 622         }
 623     }
 624
 625     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 626         match expr {
 627             Some(expr) => self.collect_expr(expr),
 628             None => self.missing_expr(),
 629         }
 630     }
 631
 632     fn collect_stmt(&mut self, s: ast::Stmt) {
 633         match s {
 634             ast::Stmt::LetStmt(stmt) => {
 635                 if self.check_cfg(&stmt).is_none() {
 636                     return;
 637                 }
 638                 let pat = self.collect_pat_opt(stmt.pat());
 639                 let type_ref =
 640                     stmt.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 641                 let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 642                 self.statements_in_scope.push(Statement::Let { pat, type_ref, initializer });
 643             }
 644             ast::Stmt::ExprStmt(stmt) => {
 645                 if let Some(expr) = stmt.expr() {
 646                     if self.check_cfg(&expr).is_none() {
 647                         return;
 648                     }
 649                 }
 650                 let has_semi = stmt.semicolon_token().is_some();
 651                 // Note that macro could be expended to multiple statements
 652                 if let Some(ast::Expr::MacroCall(m)) = stmt.expr() {
 653                     let macro_ptr = AstPtr::new(&m);
 654                     let syntax_ptr = AstPtr::new(&stmt.expr().unwrap());
 655
 656                     self.collect_macro_call(m, macro_ptr, |this, expansion| match expansion {
 657                         Some(expansion) => {
 658                             let statements: ast::MacroStmts = expansion;
 659
 660                             statements.statements().for_each(|stmt| this.collect_stmt(stmt));
 661                             if let Some(expr) = statements.expr() {
 662                                 let expr = this.collect_expr(expr);
 663                                 this.statements_in_scope.push(Statement::Expr { expr, has_semi });
 664                             }
 665                         }
 666                         None => {
 667                             let expr = this.alloc_expr(Expr::Missing, syntax_ptr.clone());
 668                             this.statements_in_scope.push(Statement::Expr { expr, has_semi });
 669                         }
 670                     });
 671                 } else {
 672                     let expr = self.collect_expr_opt(stmt.expr());
 673                     self.statements_in_scope.push(Statement::Expr { expr, has_semi });
 674                 }
 675             }
 676             ast::Stmt::Item(item) => {
 677                 self.check_cfg(&item);
 678             }
 679         }
 680     }
 681
 682     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 683         let ast_id = self.expander.ast_id(&block);
 684         let block_loc =
 685             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
 686         let block_id = self.db.intern_block(block_loc);
 687
 688         let (module, def_map) = match self.db.block_def_map(block_id) {
 689             Some(def_map) => {
 690                 self.body.block_scopes.push(block_id);
 691                 (def_map.root(), def_map)
 692             }
 693             None => (self.expander.module, self.expander.def_map.clone()),
 694         };
 695         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 696         let prev_local_module = mem::replace(&mut self.expander.module, module);
 697         let prev_statements = std::mem::take(&mut self.statements_in_scope);
 698
 699         block.statements().for_each(|s| self.collect_stmt(s));
 700         block.tail_expr().and_then(|e| {
 701             let expr = self.maybe_collect_expr(e)?;
 702             self.statements_in_scope.push(Statement::Expr { expr, has_semi: false });
 703             Some(())
 704         });
 705
 706         let mut tail = None;
 707         if let Some(Statement::Expr { expr, has_semi: false }) = self.statements_in_scope.last() {
 708             tail = Some(*expr);
 709             self.statements_in_scope.pop();
 710         }
 711         let tail = tail;
 712         let statements = std::mem::replace(&mut self.statements_in_scope, prev_statements);
 713         let syntax_node_ptr = AstPtr::new(&block.into());
 714         let expr_id = self.alloc_expr(
 715             Expr::Block { id: block_id, statements, tail, label: None },
 716             syntax_node_ptr,
 717         );
 718
 719         self.expander.def_map = prev_def_map;
 720         self.expander.module = prev_local_module;
 721         expr_id
 722     }
 723
 724     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 725         match expr {
 726             Some(block) => self.collect_block(block),
 727             None => self.missing_expr(),
 728         }
 729     }
 730
 731     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 732         let label = Label {
 733             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 734         };
 735         self.alloc_label(label, AstPtr::new(&ast_label))
 736     }
 737
 738     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 739         let pattern = match &pat {
 740             ast::Pat::IdentPat(bp) => {
 741                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 742                 let annotation =
 743                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 744                 let subpat = bp.pat().map(|subpat| self.collect_pat(subpat));
 745                 if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 746                     // This could also be a single-segment path pattern. To
 747                     // decide that, we need to try resolving the name.
 748                     let (resolved, _) = self.expander.def_map.resolve_path(
 749                         self.db,
 750                         self.expander.module,
 751                         &name.clone().into(),
 752                         BuiltinShadowMode::Other,
 753                     );
 754                     match resolved.take_values() {
 755                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 756                         Some(ModuleDefId::EnumVariantId(_)) => {
 757                             // this is only really valid for unit variants, but
 758                             // shadowing other enum variants with a pattern is
 759                             // an error anyway
 760                             Pat::Path(name.into())
 761                         }
 762                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 763                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 764                         {
 765                             // Funnily enough, record structs *can* be shadowed
 766                             // by pattern bindings (but unit or tuple structs
 767                             // can't).
 768                             Pat::Path(name.into())
 769                         }
 770                         // shadowing statics is an error as well, so we just ignore that case here
 771                         _ => Pat::Bind { name, mode: annotation, subpat },
 772                     }
 773                 } else {
 774                     Pat::Bind { name, mode: annotation, subpat }
 775                 }
 776             }
 777             ast::Pat::TupleStructPat(p) => {
 778                 let path =
 779                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 780                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 781                 Pat::TupleStruct { path, args, ellipsis }
 782             }
 783             ast::Pat::RefPat(p) => {
 784                 let pat = self.collect_pat_opt(p.pat());
 785                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 786                 Pat::Ref { pat, mutability }
 787             }
 788             ast::Pat::PathPat(p) => {
 789                 let path =
 790                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 791                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 792             }
 793             ast::Pat::OrPat(p) => {
 794                 let pats = p.pats().map(|p| self.collect_pat(p)).collect();
 795                 Pat::Or(pats)
 796             }
 797             ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat()),
 798             ast::Pat::TuplePat(p) => {
 799                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 800                 Pat::Tuple { args, ellipsis }
 801             }
 802             ast::Pat::WildcardPat(_) => Pat::Wild,
 803             ast::Pat::RecordPat(p) => {
 804                 let path =
 805                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 806                 let args: Vec<_> = p
 807                     .record_pat_field_list()
 808                     .expect("every struct should have a field list")
 809                     .fields()
 810                     .filter_map(|f| {
 811                         let ast_pat = f.pat()?;
 812                         let pat = self.collect_pat(ast_pat);
 813                         let name = f.field_name()?.as_name();
 814                         Some(RecordFieldPat { name, pat })
 815                     })
 816                     .collect();
 817
 818                 let ellipsis = p
 819                     .record_pat_field_list()
 820                     .expect("every struct should have a field list")
 821                     .dotdot_token()
 822                     .is_some();
 823
 824                 Pat::Record { path, args, ellipsis }
 825             }
 826             ast::Pat::SlicePat(p) => {
 827                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 828
 829                 // FIXME properly handle `RestPat`
 830                 Pat::Slice {
 831                     prefix: prefix.into_iter().map(|p| self.collect_pat(p)).collect(),
 832                     slice: slice.map(|p| self.collect_pat(p)),
 833                     suffix: suffix.into_iter().map(|p| self.collect_pat(p)).collect(),
 834                 }
 835             }
 836             ast::Pat::LiteralPat(lit) => {
 837                 if let Some(ast_lit) = lit.literal() {
 838                     let expr = Expr::Literal(ast_lit.kind().into());
 839                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 840                     let expr_id = self.alloc_expr(expr, expr_ptr);
 841                     Pat::Lit(expr_id)
 842                 } else {
 843                     Pat::Missing
 844                 }
 845             }
 846             ast::Pat::RestPat(_) => {
 847                 // `RestPat` requires special handling and should not be mapped
 848                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 849                 // when `RestPat` is mapped to `Pat`, which can easily happen
 850                 // when the source code being analyzed has a malformed pattern
 851                 // which includes `..` in a place where it isn't valid.
 852
 853                 Pat::Missing
 854             }
 855             ast::Pat::BoxPat(boxpat) => {
 856                 let inner = self.collect_pat_opt(boxpat.pat());
 857                 Pat::Box { inner }
 858             }
 859             ast::Pat::ConstBlockPat(const_block_pat) => {
 860                 if let Some(expr) = const_block_pat.block_expr() {
 861                     let expr_id = self.collect_block(expr);
 862                     Pat::ConstBlock(expr_id)
 863                 } else {
 864                     Pat::Missing
 865                 }
 866             }
 867             ast::Pat::MacroPat(mac) => match mac.macro_call() {
 868                 Some(call) => {
 869                     let macro_ptr = AstPtr::new(&call);
 870                     let mut pat = None;
 871                     self.collect_macro_call(call, macro_ptr, |this, expanded_pat| {
 872                         pat = Some(this.collect_pat_opt(expanded_pat));
 873                     });
 874
 875                     match pat {
 876                         Some(pat) => return pat,
 877                         None => Pat::Missing,
 878                     }
 879                 }
 880                 None => Pat::Missing,
 881             },
 882             // FIXME: implement
 883             ast::Pat::RangePat(_) => Pat::Missing,
 884         };
 885         let ptr = AstPtr::new(&pat);
 886         self.alloc_pat(pattern, Either::Left(ptr))
 887     }
 888
 889     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 890         match pat {
 891             Some(pat) => self.collect_pat(pat),
 892             None => self.missing_pat(),
 893         }
 894     }
 895
 896     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Vec<PatId>, Option<usize>) {
 897         // Find the location of the `..`, if there is one. Note that we do not
 898         // consider the possibility of there being multiple `..` here.
 899         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 900         // We want to skip the `..` pattern here, since we account for it above.
 901         let args = args
 902             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 903             .map(|p| self.collect_pat(p))
 904             .collect();
 905
 906         (args, ellipsis)
 907     }
 908
 909     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 910     /// not.
 911     fn check_cfg(&mut self, owner: &dyn ast::HasAttrs) -> Option<()> {
 912         match self.expander.parse_attrs(self.db, owner).cfg() {
 913             Some(cfg) => {
 914                 if self.expander.cfg_options().check(&cfg) != Some(false) {
 915                     return Some(());
 916                 }
 917
 918                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode {
 919                     node: InFile::new(
 920                         self.expander.current_file_id,
 921                         SyntaxNodePtr::new(owner.syntax()),
 922                     ),
 923                     cfg,
 924                     opts: self.expander.cfg_options().clone(),
 925                 });
 926
 927                 None
 928             }
 929             None => Some(()),
 930         }
 931     }
 932 }
 933
 934 impl From<ast::LiteralKind> for Literal {
 935     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
 936         match ast_lit_kind {
 937             // FIXME: these should have actual values filled in, but unsure on perf impact
 938             LiteralKind::IntNumber(lit) => {
 939                 if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
 940                     Literal::Float(Default::default(), builtin)
 941                 } else if let builtin @ Some(_) =
 942                     lit.suffix().and_then(|it| BuiltinInt::from_suffix(it))
 943                 {
 944                     Literal::Int(lit.value().unwrap_or(0) as i128, builtin)
 945                 } else {
 946                     let builtin = lit.suffix().and_then(|it| BuiltinUint::from_suffix(it));
 947                     Literal::Uint(lit.value().unwrap_or(0), builtin)
 948                 }
 949             }
 950             LiteralKind::FloatNumber(lit) => {
 951                 let ty = lit.suffix().and_then(|it| BuiltinFloat::from_suffix(it));
 952                 Literal::Float(Default::default(), ty)
 953             }
 954             LiteralKind::ByteString(bs) => {
 955                 let text = bs.value().map(Vec::from).unwrap_or_else(Default::default);
 956                 Literal::ByteString(text)
 957             }
 958             LiteralKind::String(_) => Literal::String(Default::default()),
 959             LiteralKind::Byte => Literal::Uint(Default::default(), Some(BuiltinUint::U8)),
 960             LiteralKind::Bool(val) => Literal::Bool(val),
 961             LiteralKind::Char => Literal::Char(Default::default()),
 962         }
 963     }
 964 }