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