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