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