crates/hir_def/src/body/lower.rs

   1 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
   2 //! representation.
   3
   4 use std::{mem, sync::Arc};
   5
   6 use either::Either;
   7 use hir_expand::{
   8     hygiene::Hygiene,
   9     name::{name, AsName, Name},
  10     ExpandError, HirFileId,
  11 };
  12 use la_arena::Arena;
  13 use profile::Count;
  14 use rustc_hash::FxHashMap;
  15 use syntax::{
  16     ast::{
  17         self, ArgListOwner, ArrayExprKind, AstChildren, LiteralKind, LoopBodyOwner, NameOwner,
  18         SlicePatComponents,
  19     },
  20     AstNode, AstPtr, SyntaxNodePtr,
  21 };
  22
  23 use crate::{
  24     adt::StructKind,
  25     body::{Body, BodySourceMap, Expander, LabelSource, PatPtr, SyntheticSyntax},
  26     builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint},
  27     db::DefDatabase,
  28     diagnostics::{InactiveCode, MacroError, UnresolvedProcMacro},
  29     expr::{
  30         dummy_expr_id, ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Label,
  31         LabelId, Literal, LogicOp, MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField,
  32         Statement,
  33     },
  34     item_scope::BuiltinShadowMode,
  35     item_tree::ItemTree,
  36     path::{GenericArgs, Path},
  37     type_ref::{Mutability, Rawness, TypeRef},
  38     AdtId, BlockLoc, ModuleDefId,
  39 };
  40
  41 use super::{diagnostics::BodyDiagnostic, ExprSource, PatSource};
  42
  43 pub(crate) struct LowerCtx {
  44     hygiene: Hygiene,
  45 }
  46
  47 impl LowerCtx {
  48     pub(crate) fn new(db: &dyn DefDatabase, file_id: HirFileId) -> Self {
  49         LowerCtx { hygiene: Hygiene::new(db.upcast(), file_id) }
  50     }
  51     pub(crate) fn with_hygiene(hygiene: &Hygiene) -> Self {
  52         LowerCtx { hygiene: hygiene.clone() }
  53     }
  54
  55     pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
  56         Path::from_src(ast, &self.hygiene)
  57     }
  58 }
  59
  60 pub(super) fn lower(
  61     db: &dyn DefDatabase,
  62     expander: Expander,
  63     params: Option<ast::ParamList>,
  64     body: Option<ast::Expr>,
  65 ) -> (Body, BodySourceMap) {
  66     let item_tree = db.item_tree(expander.current_file_id);
  67     ExprCollector {
  68         db,
  69         source_map: BodySourceMap::default(),
  70         body: Body {
  71             exprs: Arena::default(),
  72             pats: Arena::default(),
  73             labels: Arena::default(),
  74             params: Vec::new(),
  75             body_expr: dummy_expr_id(),
  76             block_scopes: Vec::new(),
  77             _c: Count::new(),
  78         },
  79         item_trees: {
  80             let mut map = FxHashMap::default();
  81             map.insert(expander.current_file_id, item_tree);
  82             map
  83         },
  84         expander,
  85     }
  86     .collect(params, body)
  87 }
  88
  89 struct ExprCollector<'a> {
  90     db: &'a dyn DefDatabase,
  91     expander: Expander,
  92     body: Body,
  93     source_map: BodySourceMap,
  94
  95     item_trees: FxHashMap<HirFileId, Arc<ItemTree>>,
  96 }
  97
  98 impl ExprCollector<'_> {
  99     fn collect(
 100         mut self,
 101         param_list: Option<ast::ParamList>,
 102         body: Option<ast::Expr>,
 103     ) -> (Body, BodySourceMap) {
 104         if let Some(param_list) = param_list {
 105             if let Some(self_param) = param_list.self_param() {
 106                 let ptr = AstPtr::new(&self_param);
 107                 let param_pat = self.alloc_pat(
 108                     Pat::Bind {
 109                         name: name![self],
 110                         mode: BindingAnnotation::new(
 111                             self_param.mut_token().is_some() && self_param.amp_token().is_none(),
 112                             false,
 113                         ),
 114                         subpat: None,
 115                     },
 116                     Either::Right(ptr),
 117                 );
 118                 self.body.params.push(param_pat);
 119             }
 120
 121             for param in param_list.params() {
 122                 let pat = match param.pat() {
 123                     None => continue,
 124                     Some(pat) => pat,
 125                 };
 126                 let param_pat = self.collect_pat(pat);
 127                 self.body.params.push(param_pat);
 128             }
 129         };
 130
 131         self.body.body_expr = self.collect_expr_opt(body);
 132         (self.body, self.source_map)
 133     }
 134
 135     fn ctx(&self) -> LowerCtx {
 136         LowerCtx::new(self.db, self.expander.current_file_id)
 137     }
 138
 139     fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
 140         let src = self.expander.to_source(ptr);
 141         let id = self.make_expr(expr, Ok(src.clone()));
 142         self.source_map.expr_map.insert(src, id);
 143         id
 144     }
 145     // desugared exprs don't have ptr, that's wrong and should be fixed
 146     // somehow.
 147     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
 148         self.make_expr(expr, Err(SyntheticSyntax))
 149     }
 150     fn unit(&mut self) -> ExprId {
 151         self.alloc_expr_desugared(Expr::Tuple { exprs: Vec::new() })
 152     }
 153     fn missing_expr(&mut self) -> ExprId {
 154         self.alloc_expr_desugared(Expr::Missing)
 155     }
 156     fn make_expr(&mut self, expr: Expr, src: Result<ExprSource, SyntheticSyntax>) -> ExprId {
 157         let id = self.body.exprs.alloc(expr);
 158         self.source_map.expr_map_back.insert(id, src);
 159         id
 160     }
 161
 162     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
 163         let src = self.expander.to_source(ptr);
 164         let id = self.make_pat(pat, Ok(src.clone()));
 165         self.source_map.pat_map.insert(src, id);
 166         id
 167     }
 168     fn missing_pat(&mut self) -> PatId {
 169         self.make_pat(Pat::Missing, Err(SyntheticSyntax))
 170     }
 171     fn make_pat(&mut self, pat: Pat, src: Result<PatSource, SyntheticSyntax>) -> PatId {
 172         let id = self.body.pats.alloc(pat);
 173         self.source_map.pat_map_back.insert(id, src);
 174         id
 175     }
 176
 177     fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
 178         let src = self.expander.to_source(ptr);
 179         let id = self.make_label(label, src.clone());
 180         self.source_map.label_map.insert(src, id);
 181         id
 182     }
 183     fn make_label(&mut self, label: Label, src: LabelSource) -> LabelId {
 184         let id = self.body.labels.alloc(label);
 185         self.source_map.label_map_back.insert(id, src);
 186         id
 187     }
 188
 189     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
 190         let syntax_ptr = AstPtr::new(&expr);
 191         if self.check_cfg(&expr).is_none() {
 192             return self.missing_expr();
 193         }
 194
 195         match expr {
 196             ast::Expr::IfExpr(e) => {
 197                 let then_branch = self.collect_block_opt(e.then_branch());
 198
 199                 let else_branch = e.else_branch().map(|b| match b {
 200                     ast::ElseBranch::Block(it) => self.collect_block(it),
 201                     ast::ElseBranch::IfExpr(elif) => {
 202                         let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
 203                         self.collect_expr(expr)
 204                     }
 205                 });
 206
 207                 let condition = match e.condition() {
 208                     None => self.missing_expr(),
 209                     Some(condition) => match condition.pat() {
 210                         None => self.collect_expr_opt(condition.expr()),
 211                         // if let -- desugar to match
 212                         Some(pat) => {
 213                             let pat = self.collect_pat(pat);
 214                             let match_expr = self.collect_expr_opt(condition.expr());
 215                             let placeholder_pat = self.missing_pat();
 216                             let arms = vec![
 217                                 MatchArm { pat, expr: then_branch, guard: None },
 218                                 MatchArm {
 219                                     pat: placeholder_pat,
 220                                     expr: else_branch.unwrap_or_else(|| self.unit()),
 221                                     guard: None,
 222                                 },
 223                             ];
 224                             return self
 225                                 .alloc_expr(Expr::Match { expr: match_expr, arms }, syntax_ptr);
 226                         }
 227                     },
 228                 };
 229
 230                 self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
 231             }
 232             ast::Expr::EffectExpr(e) => match e.effect() {
 233                 ast::Effect::Try(_) => {
 234                     let body = self.collect_block_opt(e.block_expr());
 235                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
 236                 }
 237                 ast::Effect::Unsafe(_) => {
 238                     let body = self.collect_block_opt(e.block_expr());
 239                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
 240                 }
 241                 // FIXME: we need to record these effects somewhere...
 242                 ast::Effect::Label(label) => {
 243                     let label = self.collect_label(label);
 244                     match e.block_expr() {
 245                         Some(block) => {
 246                             let res = self.collect_block(block);
 247                             match &mut self.body.exprs[res] {
 248                                 Expr::Block { label: block_label, .. } => {
 249                                     *block_label = Some(label);
 250                                 }
 251                                 _ => unreachable!(),
 252                             }
 253                             res
 254                         }
 255                         None => self.missing_expr(),
 256                     }
 257                 }
 258                 // FIXME: we need to record these effects somewhere...
 259                 ast::Effect::Async(_) => {
 260                     let body = self.collect_block_opt(e.block_expr());
 261                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
 262                 }
 263                 ast::Effect::Const(_) => {
 264                     let body = self.collect_block_opt(e.block_expr());
 265                     self.alloc_expr(Expr::Const { body }, syntax_ptr)
 266                 }
 267             },
 268             ast::Expr::BlockExpr(e) => self.collect_block(e),
 269             ast::Expr::LoopExpr(e) => {
 270                 let label = e.label().map(|label| self.collect_label(label));
 271                 let body = self.collect_block_opt(e.loop_body());
 272                 self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
 273             }
 274             ast::Expr::WhileExpr(e) => {
 275                 let label = e.label().map(|label| self.collect_label(label));
 276                 let body = self.collect_block_opt(e.loop_body());
 277
 278                 let condition = match e.condition() {
 279                     None => self.missing_expr(),
 280                     Some(condition) => match condition.pat() {
 281                         None => self.collect_expr_opt(condition.expr()),
 282                         // if let -- desugar to match
 283                         Some(pat) => {
 284                             cov_mark::hit!(infer_resolve_while_let);
 285                             let pat = self.collect_pat(pat);
 286                             let match_expr = self.collect_expr_opt(condition.expr());
 287                             let placeholder_pat = self.missing_pat();
 288                             let break_ =
 289                                 self.alloc_expr_desugared(Expr::Break { expr: None, label: None });
 290                             let arms = vec![
 291                                 MatchArm { pat, expr: body, guard: None },
 292                                 MatchArm { pat: placeholder_pat, expr: break_, guard: None },
 293                             ];
 294                             let match_expr =
 295                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
 296                             return self
 297                                 .alloc_expr(Expr::Loop { body: match_expr, label }, syntax_ptr);
 298                         }
 299                     },
 300                 };
 301
 302                 self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
 303             }
 304             ast::Expr::ForExpr(e) => {
 305                 let label = e.label().map(|label| self.collect_label(label));
 306                 let iterable = self.collect_expr_opt(e.iterable());
 307                 let pat = self.collect_pat_opt(e.pat());
 308                 let body = self.collect_block_opt(e.loop_body());
 309                 self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
 310             }
 311             ast::Expr::CallExpr(e) => {
 312                 let callee = self.collect_expr_opt(e.expr());
 313                 let args = if let Some(arg_list) = e.arg_list() {
 314                     arg_list.args().map(|e| self.collect_expr(e)).collect()
 315                 } else {
 316                     Vec::new()
 317                 };
 318                 self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
 319             }
 320             ast::Expr::MethodCallExpr(e) => {
 321                 let receiver = self.collect_expr_opt(e.receiver());
 322                 let args = if let Some(arg_list) = e.arg_list() {
 323                     arg_list.args().map(|e| self.collect_expr(e)).collect()
 324                 } else {
 325                     Vec::new()
 326                 };
 327                 let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 328                 let generic_args =
 329                     e.generic_arg_list().and_then(|it| GenericArgs::from_ast(&self.ctx(), it));
 330                 self.alloc_expr(
 331                     Expr::MethodCall { receiver, method_name, args, generic_args },
 332                     syntax_ptr,
 333                 )
 334             }
 335             ast::Expr::MatchExpr(e) => {
 336                 let expr = self.collect_expr_opt(e.expr());
 337                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
 338                     match_arm_list
 339                         .arms()
 340                         .filter_map(|arm| {
 341                             self.check_cfg(&arm).map(|()| MatchArm {
 342                                 pat: self.collect_pat_opt(arm.pat()),
 343                                 expr: self.collect_expr_opt(arm.expr()),
 344                                 guard: arm
 345                                     .guard()
 346                                     .and_then(|guard| guard.expr())
 347                                     .map(|e| self.collect_expr(e)),
 348                             })
 349                         })
 350                         .collect()
 351                 } else {
 352                     Vec::new()
 353                 };
 354                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
 355             }
 356             ast::Expr::PathExpr(e) => {
 357                 let path = e
 358                     .path()
 359                     .and_then(|path| self.expander.parse_path(path))
 360                     .map(Expr::Path)
 361                     .unwrap_or(Expr::Missing);
 362                 self.alloc_expr(path, syntax_ptr)
 363             }
 364             ast::Expr::ContinueExpr(e) => self.alloc_expr(
 365                 Expr::Continue { label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 366                 syntax_ptr,
 367             ),
 368             ast::Expr::BreakExpr(e) => {
 369                 let expr = e.expr().map(|e| self.collect_expr(e));
 370                 self.alloc_expr(
 371                     Expr::Break { expr, label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 372                     syntax_ptr,
 373                 )
 374             }
 375             ast::Expr::ParenExpr(e) => {
 376                 let inner = self.collect_expr_opt(e.expr());
 377                 // make the paren expr point to the inner expression as well
 378                 let src = self.expander.to_source(syntax_ptr);
 379                 self.source_map.expr_map.insert(src, inner);
 380                 inner
 381             }
 382             ast::Expr::ReturnExpr(e) => {
 383                 let expr = e.expr().map(|e| self.collect_expr(e));
 384                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
 385             }
 386             ast::Expr::YieldExpr(e) => {
 387                 let expr = e.expr().map(|e| self.collect_expr(e));
 388                 self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
 389             }
 390             ast::Expr::RecordExpr(e) => {
 391                 let path = e.path().and_then(|path| self.expander.parse_path(path));
 392                 let mut field_ptrs = Vec::new();
 393                 let record_lit = if let Some(nfl) = e.record_expr_field_list() {
 394                     let fields = nfl
 395                         .fields()
 396                         .inspect(|field| field_ptrs.push(AstPtr::new(field)))
 397                         .filter_map(|field| {
 398                             self.check_cfg(&field)?;
 399
 400                             let name = field.field_name()?.as_name();
 401
 402                             Some(RecordLitField {
 403                                 name,
 404                                 expr: match field.expr() {
 405                                     Some(e) => self.collect_expr(e),
 406                                     None => self.missing_expr(),
 407                                 },
 408                             })
 409                         })
 410                         .collect();
 411                     let spread = nfl.spread().map(|s| self.collect_expr(s));
 412                     Expr::RecordLit { path, fields, spread }
 413                 } else {
 414                     Expr::RecordLit { path, fields: Vec::new(), spread: None }
 415                 };
 416
 417                 let res = self.alloc_expr(record_lit, syntax_ptr);
 418                 for (i, ptr) in field_ptrs.into_iter().enumerate() {
 419                     let src = self.expander.to_source(ptr);
 420                     self.source_map.field_map.insert((res, i), src);
 421                 }
 422                 res
 423             }
 424             ast::Expr::FieldExpr(e) => {
 425                 let expr = self.collect_expr_opt(e.expr());
 426                 let name = match e.field_access() {
 427                     Some(kind) => kind.as_name(),
 428                     _ => Name::missing(),
 429                 };
 430                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
 431             }
 432             ast::Expr::AwaitExpr(e) => {
 433                 let expr = self.collect_expr_opt(e.expr());
 434                 self.alloc_expr(Expr::Await { expr }, syntax_ptr)
 435             }
 436             ast::Expr::TryExpr(e) => {
 437                 let expr = self.collect_expr_opt(e.expr());
 438                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
 439             }
 440             ast::Expr::CastExpr(e) => {
 441                 let expr = self.collect_expr_opt(e.expr());
 442                 let type_ref = TypeRef::from_ast_opt(&self.ctx(), e.ty());
 443                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
 444             }
 445             ast::Expr::RefExpr(e) => {
 446                 let expr = self.collect_expr_opt(e.expr());
 447                 let raw_tok = e.raw_token().is_some();
 448                 let mutability = if raw_tok {
 449                     if e.mut_token().is_some() {
 450                         Mutability::Mut
 451                     } else if e.const_token().is_some() {
 452                         Mutability::Shared
 453                     } else {
 454                         unreachable!("parser only remaps to raw_token() if matching mutability token follows")
 455                     }
 456                 } else {
 457                     Mutability::from_mutable(e.mut_token().is_some())
 458                 };
 459                 let rawness = Rawness::from_raw(raw_tok);
 460                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
 461             }
 462             ast::Expr::PrefixExpr(e) => {
 463                 let expr = self.collect_expr_opt(e.expr());
 464                 if let Some(op) = e.op_kind() {
 465                     self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr)
 466                 } else {
 467                     self.alloc_expr(Expr::Missing, syntax_ptr)
 468                 }
 469             }
 470             ast::Expr::ClosureExpr(e) => {
 471                 let mut args = Vec::new();
 472                 let mut arg_types = Vec::new();
 473                 if let Some(pl) = e.param_list() {
 474                     for param in pl.params() {
 475                         let pat = self.collect_pat_opt(param.pat());
 476                         let type_ref = param.ty().map(|it| TypeRef::from_ast(&self.ctx(), it));
 477                         args.push(pat);
 478                         arg_types.push(type_ref);
 479                     }
 480                 }
 481                 let ret_type =
 482                     e.ret_type().and_then(|r| r.ty()).map(|it| TypeRef::from_ast(&self.ctx(), it));
 483                 let body = self.collect_expr_opt(e.body());
 484                 self.alloc_expr(Expr::Lambda { args, arg_types, ret_type, body }, syntax_ptr)
 485             }
 486             ast::Expr::BinExpr(e) => {
 487                 let lhs = self.collect_expr_opt(e.lhs());
 488                 let rhs = self.collect_expr_opt(e.rhs());
 489                 let op = e.op_kind().map(BinaryOp::from);
 490                 self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
 491             }
 492             ast::Expr::TupleExpr(e) => {
 493                 let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect();
 494                 self.alloc_expr(Expr::Tuple { exprs }, syntax_ptr)
 495             }
 496             ast::Expr::BoxExpr(e) => {
 497                 let expr = self.collect_expr_opt(e.expr());
 498                 self.alloc_expr(Expr::Box { expr }, syntax_ptr)
 499             }
 500
 501             ast::Expr::ArrayExpr(e) => {
 502                 let kind = e.kind();
 503
 504                 match kind {
 505                     ArrayExprKind::ElementList(e) => {
 506                         let exprs = e.map(|expr| self.collect_expr(expr)).collect();
 507                         self.alloc_expr(Expr::Array(Array::ElementList(exprs)), syntax_ptr)
 508                     }
 509                     ArrayExprKind::Repeat { initializer, repeat } => {
 510                         let initializer = self.collect_expr_opt(initializer);
 511                         let repeat = self.collect_expr_opt(repeat);
 512                         self.alloc_expr(
 513                             Expr::Array(Array::Repeat { initializer, repeat }),
 514                             syntax_ptr,
 515                         )
 516                     }
 517                 }
 518             }
 519
 520             ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
 521             ast::Expr::IndexExpr(e) => {
 522                 let base = self.collect_expr_opt(e.base());
 523                 let index = self.collect_expr_opt(e.index());
 524                 self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
 525             }
 526             ast::Expr::RangeExpr(e) => {
 527                 let lhs = e.start().map(|lhs| self.collect_expr(lhs));
 528                 let rhs = e.end().map(|rhs| self.collect_expr(rhs));
 529                 match e.op_kind() {
 530                     Some(range_type) => {
 531                         self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
 532                     }
 533                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 534                 }
 535             }
 536             ast::Expr::MacroCall(e) => {
 537                 let mut ids = vec![];
 538                 self.collect_macro_call(e, syntax_ptr.clone(), |this, expansion| {
 539                     ids.push(match expansion {
 540                         Some(it) => this.collect_expr(it),
 541                         None => this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
 542                     })
 543                 });
 544                 ids[0]
 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         mut collector: F,
 554     ) {
 555         // File containing the macro call. Expansion errors will be attached here.
 556         let outer_file = self.expander.current_file_id;
 557
 558         let macro_call = self.expander.to_source(AstPtr::new(&e));
 559         let res = self.expander.enter_expand(self.db, e);
 560
 561         match &res.err {
 562             Some(ExpandError::UnresolvedProcMacro) => {
 563                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro(
 564                     UnresolvedProcMacro {
 565                         file: outer_file,
 566                         node: syntax_ptr.into(),
 567                         precise_location: None,
 568                         macro_name: None,
 569                     },
 570                 ));
 571             }
 572             Some(err) => {
 573                 self.source_map.diagnostics.push(BodyDiagnostic::MacroError(MacroError {
 574                     file: outer_file,
 575                     node: syntax_ptr.into(),
 576                     message: err.to_string(),
 577                 }));
 578             }
 579             None => {}
 580         }
 581
 582         match res.value {
 583             Some((mark, expansion)) => {
 584                 // FIXME: Statements are too complicated to recover from error for now.
 585                 // It is because we don't have any hygiene for local variable expansion right now.
 586                 if T::can_cast(syntax::SyntaxKind::MACRO_STMTS) && res.err.is_some() {
 587                     self.expander.exit(self.db, mark);
 588                     collector(self, None);
 589                 } else {
 590                     self.source_map.expansions.insert(macro_call, self.expander.current_file_id);
 591
 592                     let item_tree = self.db.item_tree(self.expander.current_file_id);
 593                     self.item_trees.insert(self.expander.current_file_id, item_tree);
 594
 595                     let id = collector(self, Some(expansion));
 596                     self.expander.exit(self.db, mark);
 597                     id
 598                 }
 599             }
 600             None => collector(self, None),
 601         }
 602     }
 603
 604     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 605         if let Some(expr) = expr {
 606             self.collect_expr(expr)
 607         } else {
 608             self.missing_expr()
 609         }
 610     }
 611
 612     fn collect_stmt(&mut self, s: ast::Stmt) -> Option<Vec<Statement>> {
 613         let stmt =
 614             match s {
 615                 ast::Stmt::LetStmt(stmt) => {
 616                     self.check_cfg(&stmt)?;
 617
 618                     let pat = self.collect_pat_opt(stmt.pat());
 619                     let type_ref = stmt.ty().map(|it| TypeRef::from_ast(&self.ctx(), it));
 620                     let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 621                     vec![Statement::Let { pat, type_ref, initializer }]
 622                 }
 623                 ast::Stmt::ExprStmt(stmt) => {
 624                     self.check_cfg(&stmt)?;
 625
 626                     // Note that macro could be expended to multiple statements
 627                     if let Some(ast::Expr::MacroCall(m)) = stmt.expr() {
 628                         let syntax_ptr = AstPtr::new(&stmt.expr().unwrap());
 629                         let mut stmts = vec![];
 630
 631                         self.collect_macro_call(m, syntax_ptr.clone(), |this, expansion| {
 632                             match expansion {
 633                                 Some(expansion) => {
 634                                     let statements: ast::MacroStmts = expansion;
 635
 636                                     statements.statements().for_each(|stmt| {
 637                                         if let Some(mut r) = this.collect_stmt(stmt) {
 638                                             stmts.append(&mut r);
 639                                         }
 640                                     });
 641                                     if let Some(expr) = statements.expr() {
 642                                         stmts.push(Statement::Expr(this.collect_expr(expr)));
 643                                     }
 644                                 }
 645                                 None => {
 646                                     stmts.push(Statement::Expr(
 647                                         this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
 648                                     ));
 649                                 }
 650                             }
 651                         });
 652                         stmts
 653                     } else {
 654                         vec![Statement::Expr(self.collect_expr_opt(stmt.expr()))]
 655                     }
 656                 }
 657                 ast::Stmt::Item(item) => {
 658                     self.check_cfg(&item)?;
 659
 660                     return None;
 661                 }
 662             };
 663
 664         Some(stmt)
 665     }
 666
 667     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 668         let ast_id = self.expander.ast_id(&block);
 669         let block_loc =
 670             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
 671         let block_id = self.db.intern_block(block_loc);
 672         self.body.block_scopes.push(block_id);
 673
 674         let opt_def_map = self.db.block_def_map(block_id);
 675         let has_def_map = opt_def_map.is_some();
 676         let def_map = opt_def_map.unwrap_or_else(|| self.expander.def_map.clone());
 677         let module = if has_def_map { def_map.root() } else { self.expander.module };
 678         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 679         let prev_local_module = mem::replace(&mut self.expander.module, module);
 680
 681         let statements =
 682             block.statements().filter_map(|s| self.collect_stmt(s)).flatten().collect();
 683         let tail = block.tail_expr().map(|e| self.collect_expr(e));
 684         let syntax_node_ptr = AstPtr::new(&block.into());
 685         let expr_id = self.alloc_expr(
 686             Expr::Block { id: block_id, statements, tail, label: None },
 687             syntax_node_ptr,
 688         );
 689
 690         self.expander.def_map = prev_def_map;
 691         self.expander.module = prev_local_module;
 692         expr_id
 693     }
 694
 695     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 696         if let Some(block) = expr {
 697             self.collect_block(block)
 698         } else {
 699             self.missing_expr()
 700         }
 701     }
 702
 703     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 704         let label = Label {
 705             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 706         };
 707         self.alloc_label(label, AstPtr::new(&ast_label))
 708     }
 709
 710     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 711         let pattern = match &pat {
 712             ast::Pat::IdentPat(bp) => {
 713                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 714                 let annotation =
 715                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 716                 let subpat = bp.pat().map(|subpat| self.collect_pat(subpat));
 717                 if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 718                     // This could also be a single-segment path pattern. To
 719                     // decide that, we need to try resolving the name.
 720                     let (resolved, _) = self.expander.def_map.resolve_path(
 721                         self.db,
 722                         self.expander.module,
 723                         &name.clone().into(),
 724                         BuiltinShadowMode::Other,
 725                     );
 726                     match resolved.take_values() {
 727                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 728                         Some(ModuleDefId::EnumVariantId(_)) => {
 729                             // this is only really valid for unit variants, but
 730                             // shadowing other enum variants with a pattern is
 731                             // an error anyway
 732                             Pat::Path(name.into())
 733                         }
 734                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 735                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 736                         {
 737                             // Funnily enough, record structs *can* be shadowed
 738                             // by pattern bindings (but unit or tuple structs
 739                             // can't).
 740                             Pat::Path(name.into())
 741                         }
 742                         // shadowing statics is an error as well, so we just ignore that case here
 743                         _ => Pat::Bind { name, mode: annotation, subpat },
 744                     }
 745                 } else {
 746                     Pat::Bind { name, mode: annotation, subpat }
 747                 }
 748             }
 749             ast::Pat::TupleStructPat(p) => {
 750                 let path = p.path().and_then(|path| self.expander.parse_path(path));
 751                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 752                 Pat::TupleStruct { path, args, ellipsis }
 753             }
 754             ast::Pat::RefPat(p) => {
 755                 let pat = self.collect_pat_opt(p.pat());
 756                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 757                 Pat::Ref { pat, mutability }
 758             }
 759             ast::Pat::PathPat(p) => {
 760                 let path = p.path().and_then(|path| self.expander.parse_path(path));
 761                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 762             }
 763             ast::Pat::OrPat(p) => {
 764                 let pats = p.pats().map(|p| self.collect_pat(p)).collect();
 765                 Pat::Or(pats)
 766             }
 767             ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat()),
 768             ast::Pat::TuplePat(p) => {
 769                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 770                 Pat::Tuple { args, ellipsis }
 771             }
 772             ast::Pat::WildcardPat(_) => Pat::Wild,
 773             ast::Pat::RecordPat(p) => {
 774                 let path = p.path().and_then(|path| self.expander.parse_path(path));
 775                 let args: Vec<_> = p
 776                     .record_pat_field_list()
 777                     .expect("every struct should have a field list")
 778                     .fields()
 779                     .filter_map(|f| {
 780                         let ast_pat = f.pat()?;
 781                         let pat = self.collect_pat(ast_pat);
 782                         let name = f.field_name()?.as_name();
 783                         Some(RecordFieldPat { name, pat })
 784                     })
 785                     .collect();
 786
 787                 let ellipsis = p
 788                     .record_pat_field_list()
 789                     .expect("every struct should have a field list")
 790                     .dotdot_token()
 791                     .is_some();
 792
 793                 Pat::Record { path, args, ellipsis }
 794             }
 795             ast::Pat::SlicePat(p) => {
 796                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 797
 798                 // FIXME properly handle `RestPat`
 799                 Pat::Slice {
 800                     prefix: prefix.into_iter().map(|p| self.collect_pat(p)).collect(),
 801                     slice: slice.map(|p| self.collect_pat(p)),
 802                     suffix: suffix.into_iter().map(|p| self.collect_pat(p)).collect(),
 803                 }
 804             }
 805             ast::Pat::LiteralPat(lit) => {
 806                 if let Some(ast_lit) = lit.literal() {
 807                     let expr = Expr::Literal(ast_lit.kind().into());
 808                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 809                     let expr_id = self.alloc_expr(expr, expr_ptr);
 810                     Pat::Lit(expr_id)
 811                 } else {
 812                     Pat::Missing
 813                 }
 814             }
 815             ast::Pat::RestPat(_) => {
 816                 // `RestPat` requires special handling and should not be mapped
 817                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 818                 // when `RestPat` is mapped to `Pat`, which can easily happen
 819                 // when the source code being analyzed has a malformed pattern
 820                 // which includes `..` in a place where it isn't valid.
 821
 822                 Pat::Missing
 823             }
 824             ast::Pat::BoxPat(boxpat) => {
 825                 let inner = self.collect_pat_opt(boxpat.pat());
 826                 Pat::Box { inner }
 827             }
 828             ast::Pat::ConstBlockPat(const_block_pat) => {
 829                 if let Some(expr) = const_block_pat.block_expr() {
 830                     let expr_id = self.collect_block(expr);
 831                     Pat::ConstBlock(expr_id)
 832                 } else {
 833                     Pat::Missing
 834                 }
 835             }
 836             // FIXME: implement
 837             ast::Pat::RangePat(_) | ast::Pat::MacroPat(_) => Pat::Missing,
 838         };
 839         let ptr = AstPtr::new(&pat);
 840         self.alloc_pat(pattern, Either::Left(ptr))
 841     }
 842
 843     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 844         if let Some(pat) = pat {
 845             self.collect_pat(pat)
 846         } else {
 847             self.missing_pat()
 848         }
 849     }
 850
 851     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Vec<PatId>, Option<usize>) {
 852         // Find the location of the `..`, if there is one. Note that we do not
 853         // consider the possibility of there being multiple `..` here.
 854         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 855         // We want to skip the `..` pattern here, since we account for it above.
 856         let args = args
 857             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 858             .map(|p| self.collect_pat(p))
 859             .collect();
 860
 861         (args, ellipsis)
 862     }
 863
 864     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 865     /// not.
 866     fn check_cfg(&mut self, owner: &dyn ast::AttrsOwner) -> Option<()> {
 867         match self.expander.parse_attrs(self.db, owner).cfg() {
 868             Some(cfg) => {
 869                 if self.expander.cfg_options().check(&cfg) != Some(false) {
 870                     return Some(());
 871                 }
 872
 873                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode(InactiveCode {
 874                     file: self.expander.current_file_id,
 875                     node: SyntaxNodePtr::new(owner.syntax()),
 876                     cfg,
 877                     opts: self.expander.cfg_options().clone(),
 878                 }));
 879
 880                 None
 881             }
 882             None => Some(()),
 883         }
 884     }
 885 }
 886
 887 impl From<ast::BinOp> for BinaryOp {
 888     fn from(ast_op: ast::BinOp) -> Self {
 889         match ast_op {
 890             ast::BinOp::BooleanOr => BinaryOp::LogicOp(LogicOp::Or),
 891             ast::BinOp::BooleanAnd => BinaryOp::LogicOp(LogicOp::And),
 892             ast::BinOp::EqualityTest => BinaryOp::CmpOp(CmpOp::Eq { negated: false }),
 893             ast::BinOp::NegatedEqualityTest => BinaryOp::CmpOp(CmpOp::Eq { negated: true }),
 894             ast::BinOp::LesserEqualTest => {
 895                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Less, strict: false })
 896             }
 897             ast::BinOp::GreaterEqualTest => {
 898                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Greater, strict: false })
 899             }
 900             ast::BinOp::LesserTest => {
 901                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Less, strict: true })
 902             }
 903             ast::BinOp::GreaterTest => {
 904                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Greater, strict: true })
 905             }
 906             ast::BinOp::Addition => BinaryOp::ArithOp(ArithOp::Add),
 907             ast::BinOp::Multiplication => BinaryOp::ArithOp(ArithOp::Mul),
 908             ast::BinOp::Subtraction => BinaryOp::ArithOp(ArithOp::Sub),
 909             ast::BinOp::Division => BinaryOp::ArithOp(ArithOp::Div),
 910             ast::BinOp::Remainder => BinaryOp::ArithOp(ArithOp::Rem),
 911             ast::BinOp::LeftShift => BinaryOp::ArithOp(ArithOp::Shl),
 912             ast::BinOp::RightShift => BinaryOp::ArithOp(ArithOp::Shr),
 913             ast::BinOp::BitwiseXor => BinaryOp::ArithOp(ArithOp::BitXor),
 914             ast::BinOp::BitwiseOr => BinaryOp::ArithOp(ArithOp::BitOr),
 915             ast::BinOp::BitwiseAnd => BinaryOp::ArithOp(ArithOp::BitAnd),
 916             ast::BinOp::Assignment => BinaryOp::Assignment { op: None },
 917             ast::BinOp::AddAssign => BinaryOp::Assignment { op: Some(ArithOp::Add) },
 918             ast::BinOp::DivAssign => BinaryOp::Assignment { op: Some(ArithOp::Div) },
 919             ast::BinOp::MulAssign => BinaryOp::Assignment { op: Some(ArithOp::Mul) },
 920             ast::BinOp::RemAssign => BinaryOp::Assignment { op: Some(ArithOp::Rem) },
 921             ast::BinOp::ShlAssign => BinaryOp::Assignment { op: Some(ArithOp::Shl) },
 922             ast::BinOp::ShrAssign => BinaryOp::Assignment { op: Some(ArithOp::Shr) },
 923             ast::BinOp::SubAssign => BinaryOp::Assignment { op: Some(ArithOp::Sub) },
 924             ast::BinOp::BitOrAssign => BinaryOp::Assignment { op: Some(ArithOp::BitOr) },
 925             ast::BinOp::BitAndAssign => BinaryOp::Assignment { op: Some(ArithOp::BitAnd) },
 926             ast::BinOp::BitXorAssign => BinaryOp::Assignment { op: Some(ArithOp::BitXor) },
 927         }
 928     }
 929 }
 930
 931 impl From<ast::LiteralKind> for Literal {
 932     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
 933         match ast_lit_kind {
 934             LiteralKind::IntNumber(lit) => {
 935                 if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
 936                     return Literal::Float(Default::default(), builtin);
 937                 } else if let builtin @ Some(_) =
 938                     lit.suffix().and_then(|it| BuiltinInt::from_suffix(&it))
 939                 {
 940                     Literal::Int(Default::default(), builtin)
 941                 } else {
 942                     let builtin = lit.suffix().and_then(|it| BuiltinUint::from_suffix(&it));
 943                     Literal::Uint(Default::default(), builtin)
 944                 }
 945             }
 946             LiteralKind::FloatNumber(lit) => {
 947                 let ty = lit.suffix().and_then(|it| BuiltinFloat::from_suffix(&it));
 948                 Literal::Float(Default::default(), ty)
 949             }
 950             LiteralKind::ByteString(_) => Literal::ByteString(Default::default()),
 951             LiteralKind::String(_) => Literal::String(Default::default()),
 952             LiteralKind::Byte => Literal::Uint(Default::default(), Some(BuiltinUint::U8)),
 953             LiteralKind::Bool(val) => Literal::Bool(val),
 954             LiteralKind::Char => Literal::Char(Default::default()),
 955         }
 956     }
 957 }