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