src/tools/rust-analyzer/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     ast_id_map::AstIdMap,
   9     hygiene::Hygiene,
  10     name::{name, AsName, Name},
  11     AstId, ExpandError, HirFileId, InFile,
  12 };
  13 use la_arena::Arena;
  14 use once_cell::unsync::OnceCell;
  15 use profile::Count;
  16 use rustc_hash::FxHashMap;
  17 use syntax::{
  18     ast::{
  19         self, ArrayExprKind, AstChildren, HasArgList, HasLoopBody, HasName, LiteralKind,
  20         SlicePatComponents,
  21     },
  22     AstNode, AstPtr, SyntaxNodePtr,
  23 };
  24
  25 use crate::{
  26     adt::StructKind,
  27     body::{Body, BodySourceMap, Expander, LabelSource, PatPtr, SyntheticSyntax},
  28     body::{BodyDiagnostic, ExprSource, PatSource},
  29     builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint},
  30     db::DefDatabase,
  31     expr::{
  32         dummy_expr_id, Array, BindingAnnotation, Expr, ExprId, FloatTypeWrapper, Label, LabelId,
  33         Literal, MatchArm, Pat, PatId, RecordFieldPat, RecordLitField, Statement,
  34     },
  35     intern::Interned,
  36     item_scope::BuiltinShadowMode,
  37     path::{GenericArgs, Path},
  38     type_ref::{Mutability, Rawness, TypeRef},
  39     AdtId, BlockLoc, ModuleDefId, UnresolvedMacro,
  40 };
  41
  42 pub struct LowerCtx<'a> {
  43     pub db: &'a dyn DefDatabase,
  44     hygiene: Hygiene,
  45     ast_id_map: Option<(HirFileId, OnceCell<Arc<AstIdMap>>)>,
  46 }
  47
  48 impl<'a> LowerCtx<'a> {
  49     pub fn new(db: &'a dyn DefDatabase, file_id: HirFileId) -> Self {
  50         LowerCtx {
  51             db,
  52             hygiene: Hygiene::new(db.upcast(), file_id),
  53             ast_id_map: Some((file_id, OnceCell::new())),
  54         }
  55     }
  56
  57     pub fn with_hygiene(db: &'a dyn DefDatabase, hygiene: &Hygiene) -> Self {
  58         LowerCtx { db, hygiene: hygiene.clone(), ast_id_map: None }
  59     }
  60
  61     pub(crate) fn hygiene(&self) -> &Hygiene {
  62         &self.hygiene
  63     }
  64
  65     pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
  66         Path::from_src(ast, self)
  67     }
  68
  69     pub(crate) fn ast_id<N: AstNode>(&self, db: &dyn DefDatabase, item: &N) -> Option<AstId<N>> {
  70         let &(file_id, ref ast_id_map) = self.ast_id_map.as_ref()?;
  71         let ast_id_map = ast_id_map.get_or_init(|| db.ast_id_map(file_id));
  72         Some(InFile::new(file_id, ast_id_map.ast_id(item)))
  73     }
  74 }
  75
  76 pub(super) fn lower(
  77     db: &dyn DefDatabase,
  78     expander: Expander,
  79     params: Option<ast::ParamList>,
  80     body: Option<ast::Expr>,
  81 ) -> (Body, BodySourceMap) {
  82     ExprCollector {
  83         db,
  84         source_map: BodySourceMap::default(),
  85         ast_id_map: db.ast_id_map(expander.current_file_id),
  86         body: Body {
  87             exprs: Arena::default(),
  88             pats: Arena::default(),
  89             labels: Arena::default(),
  90             params: Vec::new(),
  91             body_expr: dummy_expr_id(),
  92             block_scopes: Vec::new(),
  93             _c: Count::new(),
  94             or_pats: Default::default(),
  95         },
  96         expander,
  97         name_to_pat_grouping: Default::default(),
  98         is_lowering_inside_or_pat: false,
  99         is_lowering_assignee_expr: false,
 100     }
 101     .collect(params, body)
 102 }
 103
 104 struct ExprCollector<'a> {
 105     db: &'a dyn DefDatabase,
 106     expander: Expander,
 107     ast_id_map: Arc<AstIdMap>,
 108     body: Body,
 109     source_map: BodySourceMap,
 110     // a poor-mans union-find?
 111     name_to_pat_grouping: FxHashMap<Name, Vec<PatId>>,
 112     is_lowering_inside_or_pat: bool,
 113     is_lowering_assignee_expr: bool,
 114 }
 115
 116 impl ExprCollector<'_> {
 117     fn collect(
 118         mut self,
 119         param_list: Option<ast::ParamList>,
 120         body: Option<ast::Expr>,
 121     ) -> (Body, BodySourceMap) {
 122         if let Some(param_list) = param_list {
 123             if let Some(self_param) = param_list.self_param() {
 124                 let ptr = AstPtr::new(&self_param);
 125                 let param_pat = self.alloc_pat(
 126                     Pat::Bind {
 127                         name: name![self],
 128                         mode: BindingAnnotation::new(
 129                             self_param.mut_token().is_some() && self_param.amp_token().is_none(),
 130                             false,
 131                         ),
 132                         subpat: None,
 133                     },
 134                     Either::Right(ptr),
 135                 );
 136                 self.body.params.push(param_pat);
 137             }
 138
 139             for pat in param_list.params().filter_map(|param| param.pat()) {
 140                 let param_pat = self.collect_pat(pat);
 141                 self.body.params.push(param_pat);
 142             }
 143         };
 144
 145         self.body.body_expr = self.collect_expr_opt(body);
 146         (self.body, self.source_map)
 147     }
 148
 149     fn ctx(&self) -> LowerCtx<'_> {
 150         LowerCtx::new(self.db, self.expander.current_file_id)
 151     }
 152
 153     fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
 154         let src = self.expander.to_source(ptr);
 155         let id = self.make_expr(expr, Ok(src.clone()));
 156         self.source_map.expr_map.insert(src, id);
 157         id
 158     }
 159     // desugared exprs don't have ptr, that's wrong and should be fixed
 160     // somehow.
 161     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
 162         self.make_expr(expr, Err(SyntheticSyntax))
 163     }
 164     fn missing_expr(&mut self) -> ExprId {
 165         self.alloc_expr_desugared(Expr::Missing)
 166     }
 167     fn make_expr(&mut self, expr: Expr, src: Result<ExprSource, SyntheticSyntax>) -> ExprId {
 168         let id = self.body.exprs.alloc(expr);
 169         self.source_map.expr_map_back.insert(id, src);
 170         id
 171     }
 172
 173     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
 174         let src = self.expander.to_source(ptr);
 175         let id = self.make_pat(pat, Ok(src.clone()));
 176         self.source_map.pat_map.insert(src, id);
 177         id
 178     }
 179     fn missing_pat(&mut self) -> PatId {
 180         self.make_pat(Pat::Missing, Err(SyntheticSyntax))
 181     }
 182     fn make_pat(&mut self, pat: Pat, src: Result<PatSource, SyntheticSyntax>) -> PatId {
 183         let id = self.body.pats.alloc(pat);
 184         self.source_map.pat_map_back.insert(id, src);
 185         id
 186     }
 187
 188     fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
 189         let src = self.expander.to_source(ptr);
 190         let id = self.make_label(label, src.clone());
 191         self.source_map.label_map.insert(src, id);
 192         id
 193     }
 194     fn make_label(&mut self, label: Label, src: LabelSource) -> LabelId {
 195         let id = self.body.labels.alloc(label);
 196         self.source_map.label_map_back.insert(id, src);
 197         id
 198     }
 199
 200     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
 201         self.maybe_collect_expr(expr).unwrap_or_else(|| self.missing_expr())
 202     }
 203
 204     /// Returns `None` if and only if the expression is `#[cfg]`d out.
 205     fn maybe_collect_expr(&mut self, expr: ast::Expr) -> Option<ExprId> {
 206         let syntax_ptr = AstPtr::new(&expr);
 207         self.check_cfg(&expr)?;
 208
 209         Some(match expr {
 210             ast::Expr::IfExpr(e) => {
 211                 let then_branch = self.collect_block_opt(e.then_branch());
 212
 213                 let else_branch = e.else_branch().map(|b| match b {
 214                     ast::ElseBranch::Block(it) => self.collect_block(it),
 215                     ast::ElseBranch::IfExpr(elif) => {
 216                         let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
 217                         self.collect_expr(expr)
 218                     }
 219                 });
 220
 221                 let condition = self.collect_expr_opt(e.condition());
 222
 223                 self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
 224             }
 225             ast::Expr::LetExpr(e) => {
 226                 let pat = self.collect_pat_opt(e.pat());
 227                 let expr = self.collect_expr_opt(e.expr());
 228                 self.alloc_expr(Expr::Let { pat, expr }, syntax_ptr)
 229             }
 230             ast::Expr::BlockExpr(e) => match e.modifier() {
 231                 Some(ast::BlockModifier::Try(_)) => {
 232                     let body = self.collect_block(e);
 233                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
 234                 }
 235                 Some(ast::BlockModifier::Unsafe(_)) => {
 236                     let body = self.collect_block(e);
 237                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
 238                 }
 239                 // FIXME: we need to record these effects somewhere...
 240                 Some(ast::BlockModifier::Label(label)) => {
 241                     let label = self.collect_label(label);
 242                     let res = self.collect_block(e);
 243                     match &mut self.body.exprs[res] {
 244                         Expr::Block { label: block_label, .. } => {
 245                             *block_label = Some(label);
 246                         }
 247                         _ => unreachable!(),
 248                     }
 249                     res
 250                 }
 251                 Some(ast::BlockModifier::Async(_)) => {
 252                     let body = self.collect_block(e);
 253                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
 254                 }
 255                 Some(ast::BlockModifier::Const(_)) => {
 256                     let body = self.collect_block(e);
 257                     self.alloc_expr(Expr::Const { body }, syntax_ptr)
 258                 }
 259                 None => self.collect_block(e),
 260             },
 261             ast::Expr::LoopExpr(e) => {
 262                 let label = e.label().map(|label| self.collect_label(label));
 263                 let body = self.collect_block_opt(e.loop_body());
 264                 self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
 265             }
 266             ast::Expr::WhileExpr(e) => {
 267                 let label = e.label().map(|label| self.collect_label(label));
 268                 let body = self.collect_block_opt(e.loop_body());
 269
 270                 let condition = self.collect_expr_opt(e.condition());
 271
 272                 self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
 273             }
 274             ast::Expr::ForExpr(e) => {
 275                 let label = e.label().map(|label| self.collect_label(label));
 276                 let iterable = self.collect_expr_opt(e.iterable());
 277                 let pat = self.collect_pat_opt(e.pat());
 278                 let body = self.collect_block_opt(e.loop_body());
 279                 self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
 280             }
 281             ast::Expr::CallExpr(e) => {
 282                 let callee = self.collect_expr_opt(e.expr());
 283                 let args = if let Some(arg_list) = e.arg_list() {
 284                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 285                 } else {
 286                     Box::default()
 287                 };
 288                 self.alloc_expr(
 289                     Expr::Call { callee, args, is_assignee_expr: self.is_lowering_assignee_expr },
 290                     syntax_ptr,
 291                 )
 292             }
 293             ast::Expr::MethodCallExpr(e) => {
 294                 let receiver = self.collect_expr_opt(e.receiver());
 295                 let args = if let Some(arg_list) = e.arg_list() {
 296                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 297                 } else {
 298                     Box::default()
 299                 };
 300                 let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 301                 let generic_args = e
 302                     .generic_arg_list()
 303                     .and_then(|it| GenericArgs::from_ast(&self.ctx(), it))
 304                     .map(Box::new);
 305                 self.alloc_expr(
 306                     Expr::MethodCall { receiver, method_name, args, generic_args },
 307                     syntax_ptr,
 308                 )
 309             }
 310             ast::Expr::MatchExpr(e) => {
 311                 let expr = self.collect_expr_opt(e.expr());
 312                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
 313                     match_arm_list
 314                         .arms()
 315                         .filter_map(|arm| {
 316                             self.check_cfg(&arm).map(|()| MatchArm {
 317                                 pat: self.collect_pat_opt(arm.pat()),
 318                                 expr: self.collect_expr_opt(arm.expr()),
 319                                 guard: arm
 320                                     .guard()
 321                                     .map(|guard| self.collect_expr_opt(guard.condition())),
 322                             })
 323                         })
 324                         .collect()
 325                 } else {
 326                     Box::default()
 327                 };
 328                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
 329             }
 330             ast::Expr::PathExpr(e) => {
 331                 let path = e
 332                     .path()
 333                     .and_then(|path| self.expander.parse_path(self.db, path))
 334                     .map(Expr::Path)
 335                     .unwrap_or(Expr::Missing);
 336                 self.alloc_expr(path, syntax_ptr)
 337             }
 338             ast::Expr::ContinueExpr(e) => self.alloc_expr(
 339                 Expr::Continue { label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 340                 syntax_ptr,
 341             ),
 342             ast::Expr::BreakExpr(e) => {
 343                 let expr = e.expr().map(|e| self.collect_expr(e));
 344                 self.alloc_expr(
 345                     Expr::Break { expr, label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 346                     syntax_ptr,
 347                 )
 348             }
 349             ast::Expr::ParenExpr(e) => {
 350                 let inner = self.collect_expr_opt(e.expr());
 351                 // make the paren expr point to the inner expression as well
 352                 let src = self.expander.to_source(syntax_ptr);
 353                 self.source_map.expr_map.insert(src, inner);
 354                 inner
 355             }
 356             ast::Expr::ReturnExpr(e) => {
 357                 let expr = e.expr().map(|e| self.collect_expr(e));
 358                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
 359             }
 360             ast::Expr::YieldExpr(e) => {
 361                 let expr = e.expr().map(|e| self.collect_expr(e));
 362                 self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
 363             }
 364             ast::Expr::RecordExpr(e) => {
 365                 let path =
 366                     e.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 367                 let is_assignee_expr = self.is_lowering_assignee_expr;
 368                 let record_lit = if let Some(nfl) = e.record_expr_field_list() {
 369                     let fields = nfl
 370                         .fields()
 371                         .filter_map(|field| {
 372                             self.check_cfg(&field)?;
 373
 374                             let name = field.field_name()?.as_name();
 375
 376                             let expr = match field.expr() {
 377                                 Some(e) => self.collect_expr(e),
 378                                 None => self.missing_expr(),
 379                             };
 380                             let src = self.expander.to_source(AstPtr::new(&field));
 381                             self.source_map.field_map.insert(src.clone(), expr);
 382                             self.source_map.field_map_back.insert(expr, src);
 383                             Some(RecordLitField { name, expr })
 384                         })
 385                         .collect();
 386                     let spread = nfl.spread().map(|s| self.collect_expr(s));
 387                     let ellipsis = nfl.dotdot_token().is_some();
 388                     Expr::RecordLit { path, fields, spread, ellipsis, is_assignee_expr }
 389                 } else {
 390                     Expr::RecordLit {
 391                         path,
 392                         fields: Box::default(),
 393                         spread: None,
 394                         ellipsis: false,
 395                         is_assignee_expr,
 396                     }
 397                 };
 398
 399                 self.alloc_expr(record_lit, syntax_ptr)
 400             }
 401             ast::Expr::FieldExpr(e) => {
 402                 let expr = self.collect_expr_opt(e.expr());
 403                 let name = match e.field_access() {
 404                     Some(kind) => kind.as_name(),
 405                     _ => Name::missing(),
 406                 };
 407                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
 408             }
 409             ast::Expr::AwaitExpr(e) => {
 410                 let expr = self.collect_expr_opt(e.expr());
 411                 self.alloc_expr(Expr::Await { expr }, syntax_ptr)
 412             }
 413             ast::Expr::TryExpr(e) => {
 414                 let expr = self.collect_expr_opt(e.expr());
 415                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
 416             }
 417             ast::Expr::CastExpr(e) => {
 418                 let expr = self.collect_expr_opt(e.expr());
 419                 let type_ref = Interned::new(TypeRef::from_ast_opt(&self.ctx(), e.ty()));
 420                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
 421             }
 422             ast::Expr::RefExpr(e) => {
 423                 let expr = self.collect_expr_opt(e.expr());
 424                 let raw_tok = e.raw_token().is_some();
 425                 let mutability = if raw_tok {
 426                     if e.mut_token().is_some() {
 427                         Mutability::Mut
 428                     } else if e.const_token().is_some() {
 429                         Mutability::Shared
 430                     } else {
 431                         unreachable!("parser only remaps to raw_token() if matching mutability token follows")
 432                     }
 433                 } else {
 434                     Mutability::from_mutable(e.mut_token().is_some())
 435                 };
 436                 let rawness = Rawness::from_raw(raw_tok);
 437                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
 438             }
 439             ast::Expr::PrefixExpr(e) => {
 440                 let expr = self.collect_expr_opt(e.expr());
 441                 match e.op_kind() {
 442                     Some(op) => self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr),
 443                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 444                 }
 445             }
 446             ast::Expr::ClosureExpr(e) => {
 447                 let mut args = Vec::new();
 448                 let mut arg_types = Vec::new();
 449                 if let Some(pl) = e.param_list() {
 450                     for param in pl.params() {
 451                         let pat = self.collect_pat_opt(param.pat());
 452                         let type_ref =
 453                             param.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 454                         args.push(pat);
 455                         arg_types.push(type_ref);
 456                     }
 457                 }
 458                 let ret_type = e
 459                     .ret_type()
 460                     .and_then(|r| r.ty())
 461                     .map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 462                 let body = self.collect_expr_opt(e.body());
 463                 self.alloc_expr(
 464                     Expr::Closure {
 465                         args: args.into(),
 466                         arg_types: arg_types.into(),
 467                         ret_type,
 468                         body,
 469                     },
 470                     syntax_ptr,
 471                 )
 472             }
 473             ast::Expr::BinExpr(e) => {
 474                 let op = e.op_kind();
 475                 if let Some(ast::BinaryOp::Assignment { op: None }) = op {
 476                     self.is_lowering_assignee_expr = true;
 477                 }
 478                 let lhs = self.collect_expr_opt(e.lhs());
 479                 self.is_lowering_assignee_expr = false;
 480                 let rhs = self.collect_expr_opt(e.rhs());
 481                 self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
 482             }
 483             ast::Expr::TupleExpr(e) => {
 484                 let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect();
 485                 self.alloc_expr(
 486                     Expr::Tuple { exprs, is_assignee_expr: self.is_lowering_assignee_expr },
 487                     syntax_ptr,
 488                 )
 489             }
 490             ast::Expr::BoxExpr(e) => {
 491                 let expr = self.collect_expr_opt(e.expr());
 492                 self.alloc_expr(Expr::Box { expr }, syntax_ptr)
 493             }
 494
 495             ast::Expr::ArrayExpr(e) => {
 496                 let kind = e.kind();
 497
 498                 match kind {
 499                     ArrayExprKind::ElementList(e) => {
 500                         let elements = e.map(|expr| self.collect_expr(expr)).collect();
 501                         self.alloc_expr(
 502                             Expr::Array(Array::ElementList {
 503                                 elements,
 504                                 is_assignee_expr: self.is_lowering_assignee_expr,
 505                             }),
 506                             syntax_ptr,
 507                         )
 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::MacroExpr(e) => {
 537                 let e = e.macro_call()?;
 538                 let macro_ptr = AstPtr::new(&e);
 539                 let id = self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
 540                     expansion.map(|it| this.collect_expr(it))
 541                 });
 542                 match id {
 543                     Some(id) => {
 544                         // Make the macro-call point to its expanded expression so we can query
 545                         // semantics on syntax pointers to the macro
 546                         let src = self.expander.to_source(syntax_ptr);
 547                         self.source_map.expr_map.insert(src, id);
 548                         id
 549                     }
 550                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 551                 }
 552             }
 553             ast::Expr::MacroStmts(e) => {
 554                 let statements: Box<[_]> =
 555                     e.statements().filter_map(|s| self.collect_stmt(s)).collect();
 556                 let tail = e.expr().map(|e| self.collect_expr(e));
 557
 558                 if e.syntax().children().next().is_none() {
 559                     // HACK: make sure that macros that expand to nothing aren't treated as a `()`
 560                     // expression when used in block tail position.
 561                     cov_mark::hit!(empty_macro_in_trailing_position_is_removed);
 562                     return None;
 563                 }
 564
 565                 self.alloc_expr(Expr::MacroStmts { tail, statements }, syntax_ptr)
 566             }
 567             ast::Expr::UnderscoreExpr(_) => self.alloc_expr(Expr::Underscore, syntax_ptr),
 568         })
 569     }
 570
 571     fn collect_macro_call<F, T, U>(
 572         &mut self,
 573         mcall: ast::MacroCall,
 574         syntax_ptr: AstPtr<ast::MacroCall>,
 575         record_diagnostics: bool,
 576         collector: F,
 577     ) -> U
 578     where
 579         F: FnOnce(&mut Self, Option<T>) -> U,
 580         T: ast::AstNode,
 581     {
 582         // File containing the macro call. Expansion errors will be attached here.
 583         let outer_file = self.expander.current_file_id;
 584
 585         let macro_call_ptr = self.expander.to_source(AstPtr::new(&mcall));
 586         let res = self.expander.enter_expand(self.db, mcall);
 587
 588         let res = match res {
 589             Ok(res) => res,
 590             Err(UnresolvedMacro { path }) => {
 591                 if record_diagnostics {
 592                     self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall {
 593                         node: InFile::new(outer_file, syntax_ptr),
 594                         path,
 595                     });
 596                 }
 597                 return collector(self, None);
 598             }
 599         };
 600
 601         if record_diagnostics {
 602             match &res.err {
 603                 Some(ExpandError::UnresolvedProcMacro(krate)) => {
 604                     self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro {
 605                         node: InFile::new(outer_file, syntax_ptr),
 606                         krate: *krate,
 607                     });
 608                 }
 609                 Some(err) => {
 610                     self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
 611                         node: InFile::new(outer_file, syntax_ptr),
 612                         message: err.to_string(),
 613                     });
 614                 }
 615                 None => {}
 616             }
 617         }
 618
 619         match res.value {
 620             Some((mark, expansion)) => {
 621                 self.source_map.expansions.insert(macro_call_ptr, self.expander.current_file_id);
 622                 let prev_ast_id_map = mem::replace(
 623                     &mut self.ast_id_map,
 624                     self.db.ast_id_map(self.expander.current_file_id),
 625                 );
 626
 627                 let id = collector(self, Some(expansion));
 628                 self.ast_id_map = prev_ast_id_map;
 629                 self.expander.exit(self.db, mark);
 630                 id
 631             }
 632             None => collector(self, None),
 633         }
 634     }
 635
 636     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 637         match expr {
 638             Some(expr) => self.collect_expr(expr),
 639             None => self.missing_expr(),
 640         }
 641     }
 642
 643     fn collect_stmt(&mut self, s: ast::Stmt) -> Option<Statement> {
 644         match s {
 645             ast::Stmt::LetStmt(stmt) => {
 646                 if self.check_cfg(&stmt).is_none() {
 647                     return None;
 648                 }
 649                 let pat = self.collect_pat_opt(stmt.pat());
 650                 let type_ref =
 651                     stmt.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 652                 let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 653                 let else_branch = stmt
 654                     .let_else()
 655                     .and_then(|let_else| let_else.block_expr())
 656                     .map(|block| self.collect_block(block));
 657                 Some(Statement::Let { pat, type_ref, initializer, else_branch })
 658             }
 659             ast::Stmt::ExprStmt(stmt) => {
 660                 let expr = stmt.expr();
 661                 if let Some(expr) = &expr {
 662                     if self.check_cfg(expr).is_none() {
 663                         return None;
 664                     }
 665                 }
 666                 let has_semi = stmt.semicolon_token().is_some();
 667                 // Note that macro could be expanded to multiple statements
 668                 if let Some(expr @ ast::Expr::MacroExpr(mac)) = &expr {
 669                     let mac_call = mac.macro_call()?;
 670                     let syntax_ptr = AstPtr::new(expr);
 671                     let macro_ptr = AstPtr::new(&mac_call);
 672                     let stmt = self.collect_macro_call(
 673                         mac_call,
 674                         macro_ptr,
 675                         false,
 676                         |this, expansion: Option<ast::MacroStmts>| match expansion {
 677                             Some(expansion) => {
 678                                 let statements = expansion
 679                                     .statements()
 680                                     .filter_map(|stmt| this.collect_stmt(stmt))
 681                                     .collect();
 682                                 let tail = expansion.expr().map(|expr| this.collect_expr(expr));
 683
 684                                 let mac_stmts = this.alloc_expr(
 685                                     Expr::MacroStmts { tail, statements },
 686                                     AstPtr::new(&ast::Expr::MacroStmts(expansion)),
 687                                 );
 688
 689                                 Some(mac_stmts)
 690                             }
 691                             None => None,
 692                         },
 693                     );
 694
 695                     let expr = match stmt {
 696                         Some(expr) => {
 697                             // Make the macro-call point to its expanded expression so we can query
 698                             // semantics on syntax pointers to the macro
 699                             let src = self.expander.to_source(syntax_ptr);
 700                             self.source_map.expr_map.insert(src, expr);
 701                             expr
 702                         }
 703                         None => self.alloc_expr(Expr::Missing, syntax_ptr),
 704                     };
 705                     Some(Statement::Expr { expr, has_semi })
 706                 } else {
 707                     let expr = self.collect_expr_opt(expr);
 708                     Some(Statement::Expr { expr, has_semi })
 709                 }
 710             }
 711             ast::Stmt::Item(_item) => None,
 712         }
 713     }
 714
 715     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 716         let file_local_id = self.ast_id_map.ast_id(&block);
 717         let ast_id = AstId::new(self.expander.current_file_id, file_local_id);
 718         let block_loc =
 719             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
 720         let block_id = self.db.intern_block(block_loc);
 721
 722         let (module, def_map) = match self.db.block_def_map(block_id) {
 723             Some(def_map) => {
 724                 self.body.block_scopes.push(block_id);
 725                 (def_map.root(), def_map)
 726             }
 727             None => (self.expander.module, self.expander.def_map.clone()),
 728         };
 729         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 730         let prev_local_module = mem::replace(&mut self.expander.module, module);
 731
 732         let mut statements: Vec<_> =
 733             block.statements().filter_map(|s| self.collect_stmt(s)).collect();
 734         let tail = block.tail_expr().and_then(|e| self.maybe_collect_expr(e));
 735         let tail = tail.or_else(|| {
 736             let stmt = statements.pop()?;
 737             if let Statement::Expr { expr, has_semi: false } = stmt {
 738                 return Some(expr);
 739             }
 740             statements.push(stmt);
 741             None
 742         });
 743
 744         let syntax_node_ptr = AstPtr::new(&block.into());
 745         let expr_id = self.alloc_expr(
 746             Expr::Block {
 747                 id: block_id,
 748                 statements: statements.into_boxed_slice(),
 749                 tail,
 750                 label: None,
 751             },
 752             syntax_node_ptr,
 753         );
 754
 755         self.expander.def_map = prev_def_map;
 756         self.expander.module = prev_local_module;
 757         expr_id
 758     }
 759
 760     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 761         match expr {
 762             Some(block) => self.collect_block(block),
 763             None => self.missing_expr(),
 764         }
 765     }
 766
 767     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 768         let label = Label {
 769             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 770         };
 771         self.alloc_label(label, AstPtr::new(&ast_label))
 772     }
 773
 774     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 775         let pat_id = self.collect_pat_(pat);
 776         for (_, pats) in self.name_to_pat_grouping.drain() {
 777             let pats = Arc::<[_]>::from(pats);
 778             self.body.or_pats.extend(pats.iter().map(|&pat| (pat, pats.clone())));
 779         }
 780         self.is_lowering_inside_or_pat = false;
 781         pat_id
 782     }
 783
 784     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 785         match pat {
 786             Some(pat) => self.collect_pat(pat),
 787             None => self.missing_pat(),
 788         }
 789     }
 790
 791     fn collect_pat_(&mut self, pat: ast::Pat) -> PatId {
 792         let pattern = match &pat {
 793             ast::Pat::IdentPat(bp) => {
 794                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 795
 796                 let key = self.is_lowering_inside_or_pat.then(|| name.clone());
 797                 let annotation =
 798                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 799                 let subpat = bp.pat().map(|subpat| self.collect_pat_(subpat));
 800                 let pattern = if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 801                     // This could also be a single-segment path pattern. To
 802                     // decide that, we need to try resolving the name.
 803                     let (resolved, _) = self.expander.def_map.resolve_path(
 804                         self.db,
 805                         self.expander.module,
 806                         &name.clone().into(),
 807                         BuiltinShadowMode::Other,
 808                     );
 809                     match resolved.take_values() {
 810                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 811                         Some(ModuleDefId::EnumVariantId(_)) => {
 812                             // this is only really valid for unit variants, but
 813                             // shadowing other enum variants with a pattern is
 814                             // an error anyway
 815                             Pat::Path(name.into())
 816                         }
 817                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 818                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 819                         {
 820                             // Funnily enough, record structs *can* be shadowed
 821                             // by pattern bindings (but unit or tuple structs
 822                             // can't).
 823                             Pat::Path(name.into())
 824                         }
 825                         // shadowing statics is an error as well, so we just ignore that case here
 826                         _ => Pat::Bind { name, mode: annotation, subpat },
 827                     }
 828                 } else {
 829                     Pat::Bind { name, mode: annotation, subpat }
 830                 };
 831
 832                 let ptr = AstPtr::new(&pat);
 833                 let pat = self.alloc_pat(pattern, Either::Left(ptr));
 834                 if let Some(key) = key {
 835                     self.name_to_pat_grouping.entry(key).or_default().push(pat);
 836                 }
 837                 return pat;
 838             }
 839             ast::Pat::TupleStructPat(p) => {
 840                 let path =
 841                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 842                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 843                 Pat::TupleStruct { path, args, ellipsis }
 844             }
 845             ast::Pat::RefPat(p) => {
 846                 let pat = self.collect_pat_opt(p.pat());
 847                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 848                 Pat::Ref { pat, mutability }
 849             }
 850             ast::Pat::PathPat(p) => {
 851                 let path =
 852                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 853                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 854             }
 855             ast::Pat::OrPat(p) => {
 856                 self.is_lowering_inside_or_pat = true;
 857                 let pats = p.pats().map(|p| self.collect_pat_(p)).collect();
 858                 Pat::Or(pats)
 859             }
 860             ast::Pat::ParenPat(p) => return self.collect_pat_opt_(p.pat()),
 861             ast::Pat::TuplePat(p) => {
 862                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 863                 Pat::Tuple { args, ellipsis }
 864             }
 865             ast::Pat::WildcardPat(_) => Pat::Wild,
 866             ast::Pat::RecordPat(p) => {
 867                 let path =
 868                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 869                 let args = p
 870                     .record_pat_field_list()
 871                     .expect("every struct should have a field list")
 872                     .fields()
 873                     .filter_map(|f| {
 874                         let ast_pat = f.pat()?;
 875                         let pat = self.collect_pat_(ast_pat);
 876                         let name = f.field_name()?.as_name();
 877                         Some(RecordFieldPat { name, pat })
 878                     })
 879                     .collect();
 880
 881                 let ellipsis = p
 882                     .record_pat_field_list()
 883                     .expect("every struct should have a field list")
 884                     .rest_pat()
 885                     .is_some();
 886
 887                 Pat::Record { path, args, ellipsis }
 888             }
 889             ast::Pat::SlicePat(p) => {
 890                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 891
 892                 // FIXME properly handle `RestPat`
 893                 Pat::Slice {
 894                     prefix: prefix.into_iter().map(|p| self.collect_pat_(p)).collect(),
 895                     slice: slice.map(|p| self.collect_pat_(p)),
 896                     suffix: suffix.into_iter().map(|p| self.collect_pat_(p)).collect(),
 897                 }
 898             }
 899             ast::Pat::LiteralPat(lit) => {
 900                 if let Some(ast_lit) = lit.literal() {
 901                     let expr = Expr::Literal(ast_lit.kind().into());
 902                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 903                     let expr_id = self.alloc_expr(expr, expr_ptr);
 904                     Pat::Lit(expr_id)
 905                 } else {
 906                     Pat::Missing
 907                 }
 908             }
 909             ast::Pat::RestPat(_) => {
 910                 // `RestPat` requires special handling and should not be mapped
 911                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 912                 // when `RestPat` is mapped to `Pat`, which can easily happen
 913                 // when the source code being analyzed has a malformed pattern
 914                 // which includes `..` in a place where it isn't valid.
 915
 916                 Pat::Missing
 917             }
 918             ast::Pat::BoxPat(boxpat) => {
 919                 let inner = self.collect_pat_opt_(boxpat.pat());
 920                 Pat::Box { inner }
 921             }
 922             ast::Pat::ConstBlockPat(const_block_pat) => {
 923                 if let Some(expr) = const_block_pat.block_expr() {
 924                     let expr_id = self.collect_block(expr);
 925                     Pat::ConstBlock(expr_id)
 926                 } else {
 927                     Pat::Missing
 928                 }
 929             }
 930             ast::Pat::MacroPat(mac) => match mac.macro_call() {
 931                 Some(call) => {
 932                     let macro_ptr = AstPtr::new(&call);
 933                     let src = self.expander.to_source(Either::Left(AstPtr::new(&pat)));
 934                     let pat =
 935                         self.collect_macro_call(call, macro_ptr, true, |this, expanded_pat| {
 936                             this.collect_pat_opt_(expanded_pat)
 937                         });
 938                     self.source_map.pat_map.insert(src, pat);
 939                     return pat;
 940                 }
 941                 None => Pat::Missing,
 942             },
 943             // FIXME: implement
 944             ast::Pat::RangePat(_) => Pat::Missing,
 945         };
 946         let ptr = AstPtr::new(&pat);
 947         self.alloc_pat(pattern, Either::Left(ptr))
 948     }
 949
 950     fn collect_pat_opt_(&mut self, pat: Option<ast::Pat>) -> PatId {
 951         match pat {
 952             Some(pat) => self.collect_pat_(pat),
 953             None => self.missing_pat(),
 954         }
 955     }
 956
 957     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Box<[PatId]>, Option<usize>) {
 958         // Find the location of the `..`, if there is one. Note that we do not
 959         // consider the possibility of there being multiple `..` here.
 960         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 961         // We want to skip the `..` pattern here, since we account for it above.
 962         let args = args
 963             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 964             .map(|p| self.collect_pat_(p))
 965             .collect();
 966
 967         (args, ellipsis)
 968     }
 969
 970     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 971     /// not.
 972     fn check_cfg(&mut self, owner: &dyn ast::HasAttrs) -> Option<()> {
 973         match self.expander.parse_attrs(self.db, owner).cfg() {
 974             Some(cfg) => {
 975                 if self.expander.cfg_options().check(&cfg) != Some(false) {
 976                     return Some(());
 977                 }
 978
 979                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode {
 980                     node: InFile::new(
 981                         self.expander.current_file_id,
 982                         SyntaxNodePtr::new(owner.syntax()),
 983                     ),
 984                     cfg,
 985                     opts: self.expander.cfg_options().clone(),
 986                 });
 987
 988                 None
 989             }
 990             None => Some(()),
 991         }
 992     }
 993 }
 994
 995 impl From<ast::LiteralKind> for Literal {
 996     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
 997         match ast_lit_kind {
 998             // FIXME: these should have actual values filled in, but unsure on perf impact
 999             LiteralKind::IntNumber(lit) => {
1000                 if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
1001                     Literal::Float(
1002                         FloatTypeWrapper::new(lit.float_value().unwrap_or(Default::default())),
1003                         builtin,
1004                     )
1005                 } else if let builtin @ Some(_) = lit.suffix().and_then(BuiltinInt::from_suffix) {
1006                     Literal::Int(lit.value().unwrap_or(0) as i128, builtin)
1007                 } else {
1008                     let builtin = lit.suffix().and_then(BuiltinUint::from_suffix);
1009                     Literal::Uint(lit.value().unwrap_or(0), builtin)
1010                 }
1011             }
1012             LiteralKind::FloatNumber(lit) => {
1013                 let ty = lit.suffix().and_then(BuiltinFloat::from_suffix);
1014                 Literal::Float(FloatTypeWrapper::new(lit.value().unwrap_or(Default::default())), ty)
1015             }
1016             LiteralKind::ByteString(bs) => {
1017                 let text = bs.value().map(Box::from).unwrap_or_else(Default::default);
1018                 Literal::ByteString(text)
1019             }
1020             LiteralKind::String(s) => {
1021                 let text = s.value().map(Box::from).unwrap_or_else(Default::default);
1022                 Literal::String(text)
1023             }
1024             LiteralKind::Byte(b) => {
1025                 Literal::Uint(b.value().unwrap_or_default() as u128, Some(BuiltinUint::U8))
1026             }
1027             LiteralKind::Char(c) => Literal::Char(c.value().unwrap_or_default()),
1028             LiteralKind::Bool(val) => Literal::Bool(val),
1029         }
1030     }
1031 }