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, ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Label,
  31         LabelId, Literal, LogicOp, MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField,
  32         Statement,
  33     },
  34     intern::Interned,
  35     item_scope::BuiltinShadowMode,
  36     path::{GenericArgs, Path},
  37     type_ref::{Mutability, Rawness, TypeRef},
  38     AdtId, BlockLoc, ModuleDefId, UnresolvedMacro,
  39 };
  40
  41 pub struct LowerCtx<'a> {
  42     pub db: &'a dyn DefDatabase,
  43     hygiene: Hygiene,
  44     file_id: Option<HirFileId>,
  45     source_ast_id_map: Option<Arc<AstIdMap>>,
  46 }
  47
  48 impl<'a> LowerCtx<'a> {
  49     pub fn new(db: &'a dyn DefDatabase, file_id: HirFileId) -> Self {
  50         LowerCtx {
  51             db,
  52             hygiene: Hygiene::new(db.upcast(), file_id),
  53             file_id: Some(file_id),
  54             source_ast_id_map: Some(db.ast_id_map(file_id)),
  55         }
  56     }
  57
  58     pub fn with_hygiene(db: &'a dyn DefDatabase, hygiene: &Hygiene) -> Self {
  59         LowerCtx { db, hygiene: hygiene.clone(), file_id: None, source_ast_id_map: None }
  60     }
  61
  62     pub(crate) fn hygiene(&self) -> &Hygiene {
  63         &self.hygiene
  64     }
  65
  66     pub(crate) fn file_id(&self) -> HirFileId {
  67         self.file_id.unwrap()
  68     }
  69
  70     pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
  71         Path::from_src(ast, self)
  72     }
  73
  74     pub(crate) fn ast_id<N: AstNode>(&self, item: &N) -> Option<FileAstId<N>> {
  75         self.source_ast_id_map.as_ref().map(|ast_id_map| ast_id_map.ast_id(item))
  76     }
  77 }
  78
  79 pub(super) fn lower(
  80     db: &dyn DefDatabase,
  81     expander: Expander,
  82     params: Option<ast::ParamList>,
  83     body: Option<ast::Expr>,
  84 ) -> (Body, BodySourceMap) {
  85     ExprCollector {
  86         db,
  87         source_map: BodySourceMap::default(),
  88         body: Body {
  89             exprs: Arena::default(),
  90             pats: Arena::default(),
  91             labels: Arena::default(),
  92             params: Vec::new(),
  93             body_expr: dummy_expr_id(),
  94             block_scopes: Vec::new(),
  95             _c: Count::new(),
  96         },
  97         expander,
  98         statements_in_scope: Vec::new(),
  99     }
 100     .collect(params, body)
 101 }
 102
 103 struct ExprCollector<'a> {
 104     db: &'a dyn DefDatabase,
 105     expander: Expander,
 106     body: Body,
 107     source_map: BodySourceMap,
 108     statements_in_scope: Vec<Statement>,
 109 }
 110
 111 impl ExprCollector<'_> {
 112     fn collect(
 113         mut self,
 114         param_list: Option<ast::ParamList>,
 115         body: Option<ast::Expr>,
 116     ) -> (Body, BodySourceMap) {
 117         if let Some(param_list) = param_list {
 118             if let Some(self_param) = param_list.self_param() {
 119                 let ptr = AstPtr::new(&self_param);
 120                 let param_pat = self.alloc_pat(
 121                     Pat::Bind {
 122                         name: name![self],
 123                         mode: BindingAnnotation::new(
 124                             self_param.mut_token().is_some() && self_param.amp_token().is_none(),
 125                             false,
 126                         ),
 127                         subpat: None,
 128                     },
 129                     Either::Right(ptr),
 130                 );
 131                 self.body.params.push(param_pat);
 132             }
 133
 134             for param in param_list.params() {
 135                 let pat = match param.pat() {
 136                     None => continue,
 137                     Some(pat) => pat,
 138                 };
 139                 let param_pat = self.collect_pat(pat);
 140                 self.body.params.push(param_pat);
 141             }
 142         };
 143
 144         self.body.body_expr = self.collect_expr_opt(body);
 145         (self.body, self.source_map)
 146     }
 147
 148     fn ctx(&self) -> LowerCtx<'_> {
 149         LowerCtx::new(self.db, self.expander.current_file_id)
 150     }
 151
 152     fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
 153         let src = self.expander.to_source(ptr);
 154         let id = self.make_expr(expr, Ok(src.clone()));
 155         self.source_map.expr_map.insert(src, id);
 156         id
 157     }
 158     // desugared exprs don't have ptr, that's wrong and should be fixed
 159     // somehow.
 160     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
 161         self.make_expr(expr, Err(SyntheticSyntax))
 162     }
 163     fn unit(&mut self) -> ExprId {
 164         self.alloc_expr_desugared(Expr::Tuple { exprs: Vec::new() })
 165     }
 166     fn missing_expr(&mut self) -> ExprId {
 167         self.alloc_expr_desugared(Expr::Missing)
 168     }
 169     fn make_expr(&mut self, expr: Expr, src: Result<ExprSource, SyntheticSyntax>) -> ExprId {
 170         let id = self.body.exprs.alloc(expr);
 171         self.source_map.expr_map_back.insert(id, src);
 172         id
 173     }
 174
 175     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
 176         let src = self.expander.to_source(ptr);
 177         let id = self.make_pat(pat, Ok(src.clone()));
 178         self.source_map.pat_map.insert(src, id);
 179         id
 180     }
 181     fn missing_pat(&mut self) -> PatId {
 182         self.make_pat(Pat::Missing, Err(SyntheticSyntax))
 183     }
 184     fn make_pat(&mut self, pat: Pat, src: Result<PatSource, SyntheticSyntax>) -> PatId {
 185         let id = self.body.pats.alloc(pat);
 186         self.source_map.pat_map_back.insert(id, src);
 187         id
 188     }
 189
 190     fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
 191         let src = self.expander.to_source(ptr);
 192         let id = self.make_label(label, src.clone());
 193         self.source_map.label_map.insert(src, id);
 194         id
 195     }
 196     fn make_label(&mut self, label: Label, src: LabelSource) -> LabelId {
 197         let id = self.body.labels.alloc(label);
 198         self.source_map.label_map_back.insert(id, src);
 199         id
 200     }
 201
 202     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
 203         self.maybe_collect_expr(expr).unwrap_or_else(|| self.missing_expr())
 204     }
 205
 206     /// Returns `None` if and only if the expression is `#[cfg]`d out.
 207     fn maybe_collect_expr(&mut self, expr: ast::Expr) -> Option<ExprId> {
 208         let syntax_ptr = AstPtr::new(&expr);
 209         self.check_cfg(&expr)?;
 210
 211         Some(match expr {
 212             ast::Expr::IfExpr(e) => {
 213                 let then_branch = self.collect_block_opt(e.then_branch());
 214
 215                 let else_branch = e.else_branch().map(|b| match b {
 216                     ast::ElseBranch::Block(it) => self.collect_block(it),
 217                     ast::ElseBranch::IfExpr(elif) => {
 218                         let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
 219                         self.collect_expr(expr)
 220                     }
 221                 });
 222
 223                 let condition = match e.condition() {
 224                     None => self.missing_expr(),
 225                     Some(condition) => match condition.pat() {
 226                         None => self.collect_expr_opt(condition.expr()),
 227                         // if let -- desugar to match
 228                         Some(pat) => {
 229                             let pat = self.collect_pat(pat);
 230                             let match_expr = self.collect_expr_opt(condition.expr());
 231                             let placeholder_pat = self.missing_pat();
 232                             let arms = vec![
 233                                 MatchArm { pat, expr: then_branch, guard: None },
 234                                 MatchArm {
 235                                     pat: placeholder_pat,
 236                                     expr: else_branch.unwrap_or_else(|| self.unit()),
 237                                     guard: None,
 238                                 },
 239                             ];
 240                             return Some(
 241                                 self.alloc_expr(Expr::Match { expr: match_expr, arms }, syntax_ptr),
 242                             );
 243                         }
 244                     },
 245                 };
 246
 247                 self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
 248             }
 249             ast::Expr::EffectExpr(e) => match e.effect() {
 250                 ast::Effect::Try(_) => {
 251                     let body = self.collect_block_opt(e.block_expr());
 252                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
 253                 }
 254                 ast::Effect::Unsafe(_) => {
 255                     let body = self.collect_block_opt(e.block_expr());
 256                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
 257                 }
 258                 // FIXME: we need to record these effects somewhere...
 259                 ast::Effect::Label(label) => {
 260                     let label = self.collect_label(label);
 261                     match e.block_expr() {
 262                         Some(block) => {
 263                             let res = self.collect_block(block);
 264                             match &mut self.body.exprs[res] {
 265                                 Expr::Block { label: block_label, .. } => {
 266                                     *block_label = Some(label);
 267                                 }
 268                                 _ => unreachable!(),
 269                             }
 270                             res
 271                         }
 272                         None => self.missing_expr(),
 273                     }
 274                 }
 275                 // FIXME: we need to record these effects somewhere...
 276                 ast::Effect::Async(_) => {
 277                     let body = self.collect_block_opt(e.block_expr());
 278                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
 279                 }
 280                 ast::Effect::Const(_) => {
 281                     let body = self.collect_block_opt(e.block_expr());
 282                     self.alloc_expr(Expr::Const { body }, syntax_ptr)
 283                 }
 284             },
 285             ast::Expr::BlockExpr(e) => self.collect_block(e),
 286             ast::Expr::LoopExpr(e) => {
 287                 let label = e.label().map(|label| self.collect_label(label));
 288                 let body = self.collect_block_opt(e.loop_body());
 289                 self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
 290             }
 291             ast::Expr::WhileExpr(e) => {
 292                 let label = e.label().map(|label| self.collect_label(label));
 293                 let body = self.collect_block_opt(e.loop_body());
 294
 295                 let condition = match e.condition() {
 296                     None => self.missing_expr(),
 297                     Some(condition) => match condition.pat() {
 298                         None => self.collect_expr_opt(condition.expr()),
 299                         // if let -- desugar to match
 300                         Some(pat) => {
 301                             cov_mark::hit!(infer_resolve_while_let);
 302                             let pat = self.collect_pat(pat);
 303                             let match_expr = self.collect_expr_opt(condition.expr());
 304                             let placeholder_pat = self.missing_pat();
 305                             let break_ =
 306                                 self.alloc_expr_desugared(Expr::Break { expr: None, label: None });
 307                             let arms = vec![
 308                                 MatchArm { pat, expr: body, guard: None },
 309                                 MatchArm { pat: placeholder_pat, expr: break_, guard: None },
 310                             ];
 311                             let match_expr =
 312                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
 313                             return Some(
 314                                 self.alloc_expr(Expr::Loop { body: match_expr, label }, syntax_ptr),
 315                             );
 316                         }
 317                     },
 318                 };
 319
 320                 self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
 321             }
 322             ast::Expr::ForExpr(e) => {
 323                 let label = e.label().map(|label| self.collect_label(label));
 324                 let iterable = self.collect_expr_opt(e.iterable());
 325                 let pat = self.collect_pat_opt(e.pat());
 326                 let body = self.collect_block_opt(e.loop_body());
 327                 self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
 328             }
 329             ast::Expr::CallExpr(e) => {
 330                 let callee = self.collect_expr_opt(e.expr());
 331                 let args = if let Some(arg_list) = e.arg_list() {
 332                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 333                 } else {
 334                     Vec::new()
 335                 };
 336                 self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
 337             }
 338             ast::Expr::MethodCallExpr(e) => {
 339                 let receiver = self.collect_expr_opt(e.receiver());
 340                 let args = if let Some(arg_list) = e.arg_list() {
 341                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 342                 } else {
 343                     Vec::new()
 344                 };
 345                 let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 346                 let generic_args = e
 347                     .generic_arg_list()
 348                     .and_then(|it| GenericArgs::from_ast(&self.ctx(), it))
 349                     .map(Box::new);
 350                 self.alloc_expr(
 351                     Expr::MethodCall { receiver, method_name, args, generic_args },
 352                     syntax_ptr,
 353                 )
 354             }
 355             ast::Expr::MatchExpr(e) => {
 356                 let expr = self.collect_expr_opt(e.expr());
 357                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
 358                     match_arm_list
 359                         .arms()
 360                         .filter_map(|arm| {
 361                             self.check_cfg(&arm).map(|()| MatchArm {
 362                                 pat: self.collect_pat_opt(arm.pat()),
 363                                 expr: self.collect_expr_opt(arm.expr()),
 364                                 guard: arm
 365                                     .guard()
 366                                     .and_then(|guard| guard.expr())
 367                                     .map(|e| self.collect_expr(e)),
 368                             })
 369                         })
 370                         .collect()
 371                 } else {
 372                     Vec::new()
 373                 };
 374                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
 375             }
 376             ast::Expr::PathExpr(e) => {
 377                 let path = e
 378                     .path()
 379                     .and_then(|path| self.expander.parse_path(self.db, path))
 380                     .map(Expr::Path)
 381                     .unwrap_or(Expr::Missing);
 382                 self.alloc_expr(path, syntax_ptr)
 383             }
 384             ast::Expr::ContinueExpr(e) => self.alloc_expr(
 385                 Expr::Continue { label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 386                 syntax_ptr,
 387             ),
 388             ast::Expr::BreakExpr(e) => {
 389                 let expr = e.expr().map(|e| self.collect_expr(e));
 390                 self.alloc_expr(
 391                     Expr::Break { expr, label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 392                     syntax_ptr,
 393                 )
 394             }
 395             ast::Expr::ParenExpr(e) => {
 396                 let inner = self.collect_expr_opt(e.expr());
 397                 // make the paren expr point to the inner expression as well
 398                 let src = self.expander.to_source(syntax_ptr);
 399                 self.source_map.expr_map.insert(src, inner);
 400                 inner
 401             }
 402             ast::Expr::ReturnExpr(e) => {
 403                 let expr = e.expr().map(|e| self.collect_expr(e));
 404                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
 405             }
 406             ast::Expr::YieldExpr(e) => {
 407                 let expr = e.expr().map(|e| self.collect_expr(e));
 408                 self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
 409             }
 410             ast::Expr::RecordExpr(e) => {
 411                 let path =
 412                     e.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 413                 let record_lit = if let Some(nfl) = e.record_expr_field_list() {
 414                     let fields = nfl
 415                         .fields()
 416                         .filter_map(|field| {
 417                             self.check_cfg(&field)?;
 418
 419                             let name = field.field_name()?.as_name();
 420
 421                             let expr = match field.expr() {
 422                                 Some(e) => self.collect_expr(e),
 423                                 None => self.missing_expr(),
 424                             };
 425                             let src = self.expander.to_source(AstPtr::new(&field));
 426                             self.source_map.field_map.insert(src.clone(), expr);
 427                             self.source_map.field_map_back.insert(expr, src);
 428                             Some(RecordLitField { name, expr })
 429                         })
 430                         .collect();
 431                     let spread = nfl.spread().map(|s| self.collect_expr(s));
 432                     Expr::RecordLit { path, fields, spread }
 433                 } else {
 434                     Expr::RecordLit { path, fields: Vec::new(), spread: None }
 435                 };
 436
 437                 self.alloc_expr(record_lit, syntax_ptr)
 438             }
 439             ast::Expr::FieldExpr(e) => {
 440                 let expr = self.collect_expr_opt(e.expr());
 441                 let name = match e.field_access() {
 442                     Some(kind) => kind.as_name(),
 443                     _ => Name::missing(),
 444                 };
 445                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
 446             }
 447             ast::Expr::AwaitExpr(e) => {
 448                 let expr = self.collect_expr_opt(e.expr());
 449                 self.alloc_expr(Expr::Await { expr }, syntax_ptr)
 450             }
 451             ast::Expr::TryExpr(e) => {
 452                 let expr = self.collect_expr_opt(e.expr());
 453                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
 454             }
 455             ast::Expr::CastExpr(e) => {
 456                 let expr = self.collect_expr_opt(e.expr());
 457                 let type_ref = Interned::new(TypeRef::from_ast_opt(&self.ctx(), e.ty()));
 458                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
 459             }
 460             ast::Expr::RefExpr(e) => {
 461                 let expr = self.collect_expr_opt(e.expr());
 462                 let raw_tok = e.raw_token().is_some();
 463                 let mutability = if raw_tok {
 464                     if e.mut_token().is_some() {
 465                         Mutability::Mut
 466                     } else if e.const_token().is_some() {
 467                         Mutability::Shared
 468                     } else {
 469                         unreachable!("parser only remaps to raw_token() if matching mutability token follows")
 470                     }
 471                 } else {
 472                     Mutability::from_mutable(e.mut_token().is_some())
 473                 };
 474                 let rawness = Rawness::from_raw(raw_tok);
 475                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
 476             }
 477             ast::Expr::PrefixExpr(e) => {
 478                 let expr = self.collect_expr_opt(e.expr());
 479                 if let Some(op) = e.op_kind() {
 480                     self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr)
 481                 } else {
 482                     self.alloc_expr(Expr::Missing, syntax_ptr)
 483                 }
 484             }
 485             ast::Expr::ClosureExpr(e) => {
 486                 let mut args = Vec::new();
 487                 let mut arg_types = Vec::new();
 488                 if let Some(pl) = e.param_list() {
 489                     for param in pl.params() {
 490                         let pat = self.collect_pat_opt(param.pat());
 491                         let type_ref =
 492                             param.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 493                         args.push(pat);
 494                         arg_types.push(type_ref);
 495                     }
 496                 }
 497                 let ret_type = e
 498                     .ret_type()
 499                     .and_then(|r| r.ty())
 500                     .map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 501                 let body = self.collect_expr_opt(e.body());
 502                 self.alloc_expr(Expr::Lambda { args, arg_types, ret_type, body }, syntax_ptr)
 503             }
 504             ast::Expr::BinExpr(e) => {
 505                 let lhs = self.collect_expr_opt(e.lhs());
 506                 let rhs = self.collect_expr_opt(e.rhs());
 507                 let op = e.op_kind().map(BinaryOp::from);
 508                 self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
 509             }
 510             ast::Expr::TupleExpr(e) => {
 511                 let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect();
 512                 self.alloc_expr(Expr::Tuple { exprs }, syntax_ptr)
 513             }
 514             ast::Expr::BoxExpr(e) => {
 515                 let expr = self.collect_expr_opt(e.expr());
 516                 self.alloc_expr(Expr::Box { expr }, syntax_ptr)
 517             }
 518
 519             ast::Expr::ArrayExpr(e) => {
 520                 let kind = e.kind();
 521
 522                 match kind {
 523                     ArrayExprKind::ElementList(e) => {
 524                         let exprs = e.map(|expr| self.collect_expr(expr)).collect();
 525                         self.alloc_expr(Expr::Array(Array::ElementList(exprs)), syntax_ptr)
 526                     }
 527                     ArrayExprKind::Repeat { initializer, repeat } => {
 528                         let initializer = self.collect_expr_opt(initializer);
 529                         let repeat = self.collect_expr_opt(repeat);
 530                         self.alloc_expr(
 531                             Expr::Array(Array::Repeat { initializer, repeat }),
 532                             syntax_ptr,
 533                         )
 534                     }
 535                 }
 536             }
 537
 538             ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
 539             ast::Expr::IndexExpr(e) => {
 540                 let base = self.collect_expr_opt(e.base());
 541                 let index = self.collect_expr_opt(e.index());
 542                 self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
 543             }
 544             ast::Expr::RangeExpr(e) => {
 545                 let lhs = e.start().map(|lhs| self.collect_expr(lhs));
 546                 let rhs = e.end().map(|rhs| self.collect_expr(rhs));
 547                 match e.op_kind() {
 548                     Some(range_type) => {
 549                         self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
 550                     }
 551                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 552                 }
 553             }
 554             ast::Expr::MacroCall(e) => {
 555                 let macro_ptr = AstPtr::new(&e);
 556                 let mut ids = vec![];
 557                 self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
 558                     ids.push(match expansion {
 559                         Some(it) => this.collect_expr(it),
 560                         None => this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
 561                     })
 562                 });
 563                 ids[0]
 564             }
 565             ast::Expr::MacroStmts(e) => {
 566                 e.statements().for_each(|s| self.collect_stmt(s));
 567                 let tail = e
 568                     .expr()
 569                     .map(|e| self.collect_expr(e))
 570                     .unwrap_or_else(|| self.alloc_expr(Expr::Missing, syntax_ptr.clone()));
 571
 572                 self.alloc_expr(Expr::MacroStmts { tail }, syntax_ptr)
 573             }
 574         })
 575     }
 576
 577     fn collect_macro_call<F: FnMut(&mut Self, Option<T>), T: ast::AstNode>(
 578         &mut self,
 579         e: ast::MacroCall,
 580         syntax_ptr: AstPtr<ast::MacroCall>,
 581         is_error_recoverable: bool,
 582         mut collector: F,
 583     ) {
 584         // File containing the macro call. Expansion errors will be attached here.
 585         let outer_file = self.expander.current_file_id;
 586
 587         let macro_call = self.expander.to_source(AstPtr::new(&e));
 588         let res = self.expander.enter_expand(self.db, e);
 589
 590         let res = match res {
 591             Ok(res) => res,
 592             Err(UnresolvedMacro { path }) => {
 593                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall {
 594                     node: InFile::new(outer_file, syntax_ptr),
 595                     path,
 596                 });
 597                 collector(self, None);
 598                 return;
 599             }
 600         };
 601
 602         match &res.err {
 603             Some(ExpandError::UnresolvedProcMacro) => {
 604                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro {
 605                     node: InFile::new(outer_file, syntax_ptr),
 606                 });
 607             }
 608             Some(err) => {
 609                 self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
 610                     node: InFile::new(outer_file, syntax_ptr),
 611                     message: err.to_string(),
 612                 });
 613             }
 614             None => {}
 615         }
 616
 617         match res.value {
 618             Some((mark, expansion)) => {
 619                 // FIXME: Statements are too complicated to recover from error for now.
 620                 // It is because we don't have any hygiene for local variable expansion right now.
 621                 if !is_error_recoverable && res.err.is_some() {
 622                     self.expander.exit(self.db, mark);
 623                     collector(self, None);
 624                 } else {
 625                     self.source_map.expansions.insert(macro_call, self.expander.current_file_id);
 626
 627                     let id = collector(self, Some(expansion));
 628                     self.expander.exit(self.db, mark);
 629                     id
 630                 }
 631             }
 632             None => collector(self, None),
 633         }
 634     }
 635
 636     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 637         if let Some(expr) = expr {
 638             self.collect_expr(expr)
 639         } else {
 640             self.missing_expr()
 641         }
 642     }
 643
 644     fn collect_stmt(&mut self, s: ast::Stmt) {
 645         match s {
 646             ast::Stmt::LetStmt(stmt) => {
 647                 if self.check_cfg(&stmt).is_none() {
 648                     return;
 649                 }
 650                 let pat = self.collect_pat_opt(stmt.pat());
 651                 let type_ref =
 652                     stmt.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 653                 let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 654                 self.statements_in_scope.push(Statement::Let { pat, type_ref, initializer });
 655             }
 656             ast::Stmt::ExprStmt(stmt) => {
 657                 if self.check_cfg(&stmt).is_none() {
 658                     return;
 659                 }
 660                 let has_semi = stmt.semicolon_token().is_some();
 661                 // Note that macro could be expended to multiple statements
 662                 if let Some(ast::Expr::MacroCall(m)) = stmt.expr() {
 663                     let macro_ptr = AstPtr::new(&m);
 664                     let syntax_ptr = AstPtr::new(&stmt.expr().unwrap());
 665
 666                     self.collect_macro_call(
 667                         m,
 668                         macro_ptr,
 669                         false,
 670                         |this, expansion| match expansion {
 671                             Some(expansion) => {
 672                                 let statements: ast::MacroStmts = expansion;
 673
 674                                 statements.statements().for_each(|stmt| this.collect_stmt(stmt));
 675                                 if let Some(expr) = statements.expr() {
 676                                     let expr = this.collect_expr(expr);
 677                                     this.statements_in_scope
 678                                         .push(Statement::Expr { expr, has_semi });
 679                                 }
 680                             }
 681                             None => {
 682                                 let expr = this.alloc_expr(Expr::Missing, syntax_ptr.clone());
 683                                 this.statements_in_scope.push(Statement::Expr { expr, has_semi });
 684                             }
 685                         },
 686                     );
 687                 } else {
 688                     let expr = self.collect_expr_opt(stmt.expr());
 689                     self.statements_in_scope.push(Statement::Expr { expr, has_semi });
 690                 }
 691             }
 692             ast::Stmt::Item(item) => {
 693                 self.check_cfg(&item);
 694             }
 695         }
 696     }
 697
 698     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 699         let ast_id = self.expander.ast_id(&block);
 700         let block_loc =
 701             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
 702         let block_id = self.db.intern_block(block_loc);
 703
 704         let (module, def_map) = match self.db.block_def_map(block_id) {
 705             Some(def_map) => {
 706                 self.body.block_scopes.push(block_id);
 707                 (def_map.root(), def_map)
 708             }
 709             None => (self.expander.module, self.expander.def_map.clone()),
 710         };
 711         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 712         let prev_local_module = mem::replace(&mut self.expander.module, module);
 713         let prev_statements = std::mem::take(&mut self.statements_in_scope);
 714
 715         block.statements().for_each(|s| self.collect_stmt(s));
 716         block.tail_expr().and_then(|e| {
 717             let expr = self.maybe_collect_expr(e)?;
 718             self.statements_in_scope.push(Statement::Expr { expr, has_semi: false });
 719             Some(())
 720         });
 721
 722         let mut tail = None;
 723         if let Some(Statement::Expr { expr, has_semi: false }) = self.statements_in_scope.last() {
 724             tail = Some(*expr);
 725             self.statements_in_scope.pop();
 726         }
 727         let tail = tail;
 728         let statements = std::mem::replace(&mut self.statements_in_scope, prev_statements);
 729         let syntax_node_ptr = AstPtr::new(&block.into());
 730         let expr_id = self.alloc_expr(
 731             Expr::Block { id: block_id, statements, tail, label: None },
 732             syntax_node_ptr,
 733         );
 734
 735         self.expander.def_map = prev_def_map;
 736         self.expander.module = prev_local_module;
 737         expr_id
 738     }
 739
 740     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 741         if let Some(block) = expr {
 742             self.collect_block(block)
 743         } else {
 744             self.missing_expr()
 745         }
 746     }
 747
 748     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 749         let label = Label {
 750             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 751         };
 752         self.alloc_label(label, AstPtr::new(&ast_label))
 753     }
 754
 755     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 756         let pattern = match &pat {
 757             ast::Pat::IdentPat(bp) => {
 758                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 759                 let annotation =
 760                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 761                 let subpat = bp.pat().map(|subpat| self.collect_pat(subpat));
 762                 if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 763                     // This could also be a single-segment path pattern. To
 764                     // decide that, we need to try resolving the name.
 765                     let (resolved, _) = self.expander.def_map.resolve_path(
 766                         self.db,
 767                         self.expander.module,
 768                         &name.clone().into(),
 769                         BuiltinShadowMode::Other,
 770                     );
 771                     match resolved.take_values() {
 772                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 773                         Some(ModuleDefId::EnumVariantId(_)) => {
 774                             // this is only really valid for unit variants, but
 775                             // shadowing other enum variants with a pattern is
 776                             // an error anyway
 777                             Pat::Path(name.into())
 778                         }
 779                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 780                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 781                         {
 782                             // Funnily enough, record structs *can* be shadowed
 783                             // by pattern bindings (but unit or tuple structs
 784                             // can't).
 785                             Pat::Path(name.into())
 786                         }
 787                         // shadowing statics is an error as well, so we just ignore that case here
 788                         _ => Pat::Bind { name, mode: annotation, subpat },
 789                     }
 790                 } else {
 791                     Pat::Bind { name, mode: annotation, subpat }
 792                 }
 793             }
 794             ast::Pat::TupleStructPat(p) => {
 795                 let path =
 796                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 797                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 798                 Pat::TupleStruct { path, args, ellipsis }
 799             }
 800             ast::Pat::RefPat(p) => {
 801                 let pat = self.collect_pat_opt(p.pat());
 802                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 803                 Pat::Ref { pat, mutability }
 804             }
 805             ast::Pat::PathPat(p) => {
 806                 let path =
 807                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 808                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 809             }
 810             ast::Pat::OrPat(p) => {
 811                 let pats = p.pats().map(|p| self.collect_pat(p)).collect();
 812                 Pat::Or(pats)
 813             }
 814             ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat()),
 815             ast::Pat::TuplePat(p) => {
 816                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 817                 Pat::Tuple { args, ellipsis }
 818             }
 819             ast::Pat::WildcardPat(_) => Pat::Wild,
 820             ast::Pat::RecordPat(p) => {
 821                 let path =
 822                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 823                 let args: Vec<_> = p
 824                     .record_pat_field_list()
 825                     .expect("every struct should have a field list")
 826                     .fields()
 827                     .filter_map(|f| {
 828                         let ast_pat = f.pat()?;
 829                         let pat = self.collect_pat(ast_pat);
 830                         let name = f.field_name()?.as_name();
 831                         Some(RecordFieldPat { name, pat })
 832                     })
 833                     .collect();
 834
 835                 let ellipsis = p
 836                     .record_pat_field_list()
 837                     .expect("every struct should have a field list")
 838                     .dotdot_token()
 839                     .is_some();
 840
 841                 Pat::Record { path, args, ellipsis }
 842             }
 843             ast::Pat::SlicePat(p) => {
 844                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 845
 846                 // FIXME properly handle `RestPat`
 847                 Pat::Slice {
 848                     prefix: prefix.into_iter().map(|p| self.collect_pat(p)).collect(),
 849                     slice: slice.map(|p| self.collect_pat(p)),
 850                     suffix: suffix.into_iter().map(|p| self.collect_pat(p)).collect(),
 851                 }
 852             }
 853             ast::Pat::LiteralPat(lit) => {
 854                 if let Some(ast_lit) = lit.literal() {
 855                     let expr = Expr::Literal(ast_lit.kind().into());
 856                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 857                     let expr_id = self.alloc_expr(expr, expr_ptr);
 858                     Pat::Lit(expr_id)
 859                 } else {
 860                     Pat::Missing
 861                 }
 862             }
 863             ast::Pat::RestPat(_) => {
 864                 // `RestPat` requires special handling and should not be mapped
 865                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 866                 // when `RestPat` is mapped to `Pat`, which can easily happen
 867                 // when the source code being analyzed has a malformed pattern
 868                 // which includes `..` in a place where it isn't valid.
 869
 870                 Pat::Missing
 871             }
 872             ast::Pat::BoxPat(boxpat) => {
 873                 let inner = self.collect_pat_opt(boxpat.pat());
 874                 Pat::Box { inner }
 875             }
 876             ast::Pat::ConstBlockPat(const_block_pat) => {
 877                 if let Some(expr) = const_block_pat.block_expr() {
 878                     let expr_id = self.collect_block(expr);
 879                     Pat::ConstBlock(expr_id)
 880                 } else {
 881                     Pat::Missing
 882                 }
 883             }
 884             ast::Pat::MacroPat(mac) => match mac.macro_call() {
 885                 Some(call) => {
 886                     let macro_ptr = AstPtr::new(&call);
 887                     let mut pat = None;
 888                     self.collect_macro_call(call, macro_ptr, true, |this, expanded_pat| {
 889                         pat = Some(this.collect_pat_opt(expanded_pat));
 890                     });
 891
 892                     match pat {
 893                         Some(pat) => return pat,
 894                         None => Pat::Missing,
 895                     }
 896                 }
 897                 None => Pat::Missing,
 898             },
 899             // FIXME: implement
 900             ast::Pat::RangePat(_) => Pat::Missing,
 901         };
 902         let ptr = AstPtr::new(&pat);
 903         self.alloc_pat(pattern, Either::Left(ptr))
 904     }
 905
 906     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 907         if let Some(pat) = pat {
 908             self.collect_pat(pat)
 909         } else {
 910             self.missing_pat()
 911         }
 912     }
 913
 914     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Vec<PatId>, Option<usize>) {
 915         // Find the location of the `..`, if there is one. Note that we do not
 916         // consider the possibility of there being multiple `..` here.
 917         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 918         // We want to skip the `..` pattern here, since we account for it above.
 919         let args = args
 920             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 921             .map(|p| self.collect_pat(p))
 922             .collect();
 923
 924         (args, ellipsis)
 925     }
 926
 927     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 928     /// not.
 929     fn check_cfg(&mut self, owner: &dyn ast::AttrsOwner) -> Option<()> {
 930         match self.expander.parse_attrs(self.db, owner).cfg() {
 931             Some(cfg) => {
 932                 if self.expander.cfg_options().check(&cfg) != Some(false) {
 933                     return Some(());
 934                 }
 935
 936                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode {
 937                     node: InFile::new(
 938                         self.expander.current_file_id,
 939                         SyntaxNodePtr::new(owner.syntax()),
 940                     ),
 941                     cfg,
 942                     opts: self.expander.cfg_options().clone(),
 943                 });
 944
 945                 None
 946             }
 947             None => Some(()),
 948         }
 949     }
 950 }
 951
 952 impl From<ast::BinOp> for BinaryOp {
 953     fn from(ast_op: ast::BinOp) -> Self {
 954         match ast_op {
 955             ast::BinOp::BooleanOr => BinaryOp::LogicOp(LogicOp::Or),
 956             ast::BinOp::BooleanAnd => BinaryOp::LogicOp(LogicOp::And),
 957             ast::BinOp::EqualityTest => BinaryOp::CmpOp(CmpOp::Eq { negated: false }),
 958             ast::BinOp::NegatedEqualityTest => BinaryOp::CmpOp(CmpOp::Eq { negated: true }),
 959             ast::BinOp::LesserEqualTest => {
 960                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Less, strict: false })
 961             }
 962             ast::BinOp::GreaterEqualTest => {
 963                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Greater, strict: false })
 964             }
 965             ast::BinOp::LesserTest => {
 966                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Less, strict: true })
 967             }
 968             ast::BinOp::GreaterTest => {
 969                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Greater, strict: true })
 970             }
 971             ast::BinOp::Addition => BinaryOp::ArithOp(ArithOp::Add),
 972             ast::BinOp::Multiplication => BinaryOp::ArithOp(ArithOp::Mul),
 973             ast::BinOp::Subtraction => BinaryOp::ArithOp(ArithOp::Sub),
 974             ast::BinOp::Division => BinaryOp::ArithOp(ArithOp::Div),
 975             ast::BinOp::Remainder => BinaryOp::ArithOp(ArithOp::Rem),
 976             ast::BinOp::LeftShift => BinaryOp::ArithOp(ArithOp::Shl),
 977             ast::BinOp::RightShift => BinaryOp::ArithOp(ArithOp::Shr),
 978             ast::BinOp::BitwiseXor => BinaryOp::ArithOp(ArithOp::BitXor),
 979             ast::BinOp::BitwiseOr => BinaryOp::ArithOp(ArithOp::BitOr),
 980             ast::BinOp::BitwiseAnd => BinaryOp::ArithOp(ArithOp::BitAnd),
 981             ast::BinOp::Assignment => BinaryOp::Assignment { op: None },
 982             ast::BinOp::AddAssign => BinaryOp::Assignment { op: Some(ArithOp::Add) },
 983             ast::BinOp::DivAssign => BinaryOp::Assignment { op: Some(ArithOp::Div) },
 984             ast::BinOp::MulAssign => BinaryOp::Assignment { op: Some(ArithOp::Mul) },
 985             ast::BinOp::RemAssign => BinaryOp::Assignment { op: Some(ArithOp::Rem) },
 986             ast::BinOp::ShlAssign => BinaryOp::Assignment { op: Some(ArithOp::Shl) },
 987             ast::BinOp::ShrAssign => BinaryOp::Assignment { op: Some(ArithOp::Shr) },
 988             ast::BinOp::SubAssign => BinaryOp::Assignment { op: Some(ArithOp::Sub) },
 989             ast::BinOp::BitOrAssign => BinaryOp::Assignment { op: Some(ArithOp::BitOr) },
 990             ast::BinOp::BitAndAssign => BinaryOp::Assignment { op: Some(ArithOp::BitAnd) },
 991             ast::BinOp::BitXorAssign => BinaryOp::Assignment { op: Some(ArithOp::BitXor) },
 992         }
 993     }
 994 }
 995
 996 impl From<ast::LiteralKind> for Literal {
 997     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
 998         match ast_lit_kind {
 999             // FIXME: these should have actual values filled in, but unsure on perf impact
1000             LiteralKind::IntNumber(lit) => {
1001                 if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
1002                     Literal::Float(Default::default(), builtin)
1003                 } else if let builtin @ Some(_) =
1004                     lit.suffix().and_then(|it| BuiltinInt::from_suffix(it))
1005                 {
1006                     Literal::Int(lit.value().unwrap_or(0) as i128, builtin)
1007                 } else {
1008                     let builtin = lit.suffix().and_then(|it| BuiltinUint::from_suffix(it));
1009                     Literal::Uint(lit.value().unwrap_or(0), builtin)
1010                 }
1011             }
1012             LiteralKind::FloatNumber(lit) => {
1013                 let ty = lit.suffix().and_then(|it| BuiltinFloat::from_suffix(it));
1014                 Literal::Float(Default::default(), ty)
1015             }
1016             LiteralKind::ByteString(bs) => {
1017                 let text = bs.value().map(Vec::from).unwrap_or_else(Default::default);
1018                 Literal::ByteString(text)
1019             }
1020             LiteralKind::String(_) => Literal::String(Default::default()),
1021             LiteralKind::Byte => Literal::Uint(Default::default(), Some(BuiltinUint::U8)),
1022             LiteralKind::Bool(val) => Literal::Bool(val),
1023             LiteralKind::Char => Literal::Char(Default::default()),
1024         }
1025     }
1026 }