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 = e.statements().filter_map(|s| self.collect_stmt(s)).collect();
 555                 let tail = e.expr().map(|e| self.collect_expr(e));
 556
 557                 self.alloc_expr(Expr::MacroStmts { tail, statements }, syntax_ptr)
 558             }
 559             ast::Expr::UnderscoreExpr(_) => self.alloc_expr(Expr::Underscore, syntax_ptr),
 560         })
 561     }
 562
 563     fn collect_macro_call<F, T, U>(
 564         &mut self,
 565         mcall: ast::MacroCall,
 566         syntax_ptr: AstPtr<ast::MacroCall>,
 567         record_diagnostics: bool,
 568         collector: F,
 569     ) -> U
 570     where
 571         F: FnOnce(&mut Self, Option<T>) -> U,
 572         T: ast::AstNode,
 573     {
 574         // File containing the macro call. Expansion errors will be attached here.
 575         let outer_file = self.expander.current_file_id;
 576
 577         let macro_call_ptr = self.expander.to_source(AstPtr::new(&mcall));
 578         let res = self.expander.enter_expand(self.db, mcall);
 579
 580         let res = match res {
 581             Ok(res) => res,
 582             Err(UnresolvedMacro { path }) => {
 583                 if record_diagnostics {
 584                     self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall {
 585                         node: InFile::new(outer_file, syntax_ptr),
 586                         path,
 587                     });
 588                 }
 589                 return collector(self, None);
 590             }
 591         };
 592
 593         if record_diagnostics {
 594             match &res.err {
 595                 Some(ExpandError::UnresolvedProcMacro(krate)) => {
 596                     self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro {
 597                         node: InFile::new(outer_file, syntax_ptr),
 598                         krate: *krate,
 599                     });
 600                 }
 601                 Some(err) => {
 602                     self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
 603                         node: InFile::new(outer_file, syntax_ptr),
 604                         message: err.to_string(),
 605                     });
 606                 }
 607                 None => {}
 608             }
 609         }
 610
 611         match res.value {
 612             Some((mark, expansion)) => {
 613                 self.source_map.expansions.insert(macro_call_ptr, self.expander.current_file_id);
 614                 let prev_ast_id_map = mem::replace(
 615                     &mut self.ast_id_map,
 616                     self.db.ast_id_map(self.expander.current_file_id),
 617                 );
 618
 619                 let id = collector(self, Some(expansion));
 620                 self.ast_id_map = prev_ast_id_map;
 621                 self.expander.exit(self.db, mark);
 622                 id
 623             }
 624             None => collector(self, None),
 625         }
 626     }
 627
 628     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 629         match expr {
 630             Some(expr) => self.collect_expr(expr),
 631             None => self.missing_expr(),
 632         }
 633     }
 634
 635     fn collect_stmt(&mut self, s: ast::Stmt) -> Option<Statement> {
 636         match s {
 637             ast::Stmt::LetStmt(stmt) => {
 638                 if self.check_cfg(&stmt).is_none() {
 639                     return None;
 640                 }
 641                 let pat = self.collect_pat_opt(stmt.pat());
 642                 let type_ref =
 643                     stmt.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 644                 let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 645                 let else_branch = stmt
 646                     .let_else()
 647                     .and_then(|let_else| let_else.block_expr())
 648                     .map(|block| self.collect_block(block));
 649                 Some(Statement::Let { pat, type_ref, initializer, else_branch })
 650             }
 651             ast::Stmt::ExprStmt(stmt) => {
 652                 let expr = stmt.expr();
 653                 if let Some(expr) = &expr {
 654                     if self.check_cfg(expr).is_none() {
 655                         return None;
 656                     }
 657                 }
 658                 let has_semi = stmt.semicolon_token().is_some();
 659                 // Note that macro could be expanded to multiple statements
 660                 if let Some(expr @ ast::Expr::MacroExpr(mac)) = &expr {
 661                     let mac_call = mac.macro_call()?;
 662                     let syntax_ptr = AstPtr::new(expr);
 663                     let macro_ptr = AstPtr::new(&mac_call);
 664                     let stmt = self.collect_macro_call(
 665                         mac_call,
 666                         macro_ptr,
 667                         false,
 668                         |this, expansion: Option<ast::MacroStmts>| match expansion {
 669                             Some(expansion) => {
 670                                 let statements = expansion
 671                                     .statements()
 672                                     .filter_map(|stmt| this.collect_stmt(stmt))
 673                                     .collect();
 674                                 let tail = expansion.expr().map(|expr| this.collect_expr(expr));
 675
 676                                 let mac_stmts = this.alloc_expr(
 677                                     Expr::MacroStmts { tail, statements },
 678                                     AstPtr::new(&ast::Expr::MacroStmts(expansion)),
 679                                 );
 680
 681                                 Some(mac_stmts)
 682                             }
 683                             None => None,
 684                         },
 685                     );
 686
 687                     let expr = match stmt {
 688                         Some(expr) => {
 689                             // Make the macro-call point to its expanded expression so we can query
 690                             // semantics on syntax pointers to the macro
 691                             let src = self.expander.to_source(syntax_ptr);
 692                             self.source_map.expr_map.insert(src, expr);
 693                             expr
 694                         }
 695                         None => self.alloc_expr(Expr::Missing, syntax_ptr),
 696                     };
 697                     Some(Statement::Expr { expr, has_semi })
 698                 } else {
 699                     let expr = self.collect_expr_opt(expr);
 700                     Some(Statement::Expr { expr, has_semi })
 701                 }
 702             }
 703             ast::Stmt::Item(_item) => None,
 704         }
 705     }
 706
 707     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 708         let file_local_id = self.ast_id_map.ast_id(&block);
 709         let ast_id = AstId::new(self.expander.current_file_id, file_local_id);
 710         let block_loc =
 711             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
 712         let block_id = self.db.intern_block(block_loc);
 713
 714         let (module, def_map) = match self.db.block_def_map(block_id) {
 715             Some(def_map) => {
 716                 self.body.block_scopes.push(block_id);
 717                 (def_map.root(), def_map)
 718             }
 719             None => (self.expander.module, self.expander.def_map.clone()),
 720         };
 721         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 722         let prev_local_module = mem::replace(&mut self.expander.module, module);
 723
 724         let mut statements: Vec<_> =
 725             block.statements().filter_map(|s| self.collect_stmt(s)).collect();
 726         let tail = block.tail_expr().and_then(|e| self.maybe_collect_expr(e));
 727         let tail = tail.or_else(|| {
 728             let stmt = statements.pop()?;
 729             if let Statement::Expr { expr, has_semi: false } = stmt {
 730                 return Some(expr);
 731             }
 732             statements.push(stmt);
 733             None
 734         });
 735
 736         let syntax_node_ptr = AstPtr::new(&block.into());
 737         let expr_id = self.alloc_expr(
 738             Expr::Block {
 739                 id: block_id,
 740                 statements: statements.into_boxed_slice(),
 741                 tail,
 742                 label: None,
 743             },
 744             syntax_node_ptr,
 745         );
 746
 747         self.expander.def_map = prev_def_map;
 748         self.expander.module = prev_local_module;
 749         expr_id
 750     }
 751
 752     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 753         match expr {
 754             Some(block) => self.collect_block(block),
 755             None => self.missing_expr(),
 756         }
 757     }
 758
 759     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 760         let label = Label {
 761             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 762         };
 763         self.alloc_label(label, AstPtr::new(&ast_label))
 764     }
 765
 766     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 767         let pat_id = self.collect_pat_(pat);
 768         for (_, pats) in self.name_to_pat_grouping.drain() {
 769             let pats = Arc::<[_]>::from(pats);
 770             self.body.or_pats.extend(pats.iter().map(|&pat| (pat, pats.clone())));
 771         }
 772         self.is_lowering_inside_or_pat = false;
 773         pat_id
 774     }
 775
 776     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 777         match pat {
 778             Some(pat) => self.collect_pat(pat),
 779             None => self.missing_pat(),
 780         }
 781     }
 782
 783     fn collect_pat_(&mut self, pat: ast::Pat) -> PatId {
 784         let pattern = match &pat {
 785             ast::Pat::IdentPat(bp) => {
 786                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 787
 788                 let key = self.is_lowering_inside_or_pat.then(|| name.clone());
 789                 let annotation =
 790                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 791                 let subpat = bp.pat().map(|subpat| self.collect_pat_(subpat));
 792                 let pattern = if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 793                     // This could also be a single-segment path pattern. To
 794                     // decide that, we need to try resolving the name.
 795                     let (resolved, _) = self.expander.def_map.resolve_path(
 796                         self.db,
 797                         self.expander.module,
 798                         &name.clone().into(),
 799                         BuiltinShadowMode::Other,
 800                     );
 801                     match resolved.take_values() {
 802                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 803                         Some(ModuleDefId::EnumVariantId(_)) => {
 804                             // this is only really valid for unit variants, but
 805                             // shadowing other enum variants with a pattern is
 806                             // an error anyway
 807                             Pat::Path(name.into())
 808                         }
 809                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 810                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 811                         {
 812                             // Funnily enough, record structs *can* be shadowed
 813                             // by pattern bindings (but unit or tuple structs
 814                             // can't).
 815                             Pat::Path(name.into())
 816                         }
 817                         // shadowing statics is an error as well, so we just ignore that case here
 818                         _ => Pat::Bind { name, mode: annotation, subpat },
 819                     }
 820                 } else {
 821                     Pat::Bind { name, mode: annotation, subpat }
 822                 };
 823
 824                 let ptr = AstPtr::new(&pat);
 825                 let pat = self.alloc_pat(pattern, Either::Left(ptr));
 826                 if let Some(key) = key {
 827                     self.name_to_pat_grouping.entry(key).or_default().push(pat);
 828                 }
 829                 return pat;
 830             }
 831             ast::Pat::TupleStructPat(p) => {
 832                 let path =
 833                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 834                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 835                 Pat::TupleStruct { path, args, ellipsis }
 836             }
 837             ast::Pat::RefPat(p) => {
 838                 let pat = self.collect_pat_opt(p.pat());
 839                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 840                 Pat::Ref { pat, mutability }
 841             }
 842             ast::Pat::PathPat(p) => {
 843                 let path =
 844                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 845                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 846             }
 847             ast::Pat::OrPat(p) => {
 848                 self.is_lowering_inside_or_pat = true;
 849                 let pats = p.pats().map(|p| self.collect_pat_(p)).collect();
 850                 Pat::Or(pats)
 851             }
 852             ast::Pat::ParenPat(p) => return self.collect_pat_opt_(p.pat()),
 853             ast::Pat::TuplePat(p) => {
 854                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 855                 Pat::Tuple { args, ellipsis }
 856             }
 857             ast::Pat::WildcardPat(_) => Pat::Wild,
 858             ast::Pat::RecordPat(p) => {
 859                 let path =
 860                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 861                 let args = p
 862                     .record_pat_field_list()
 863                     .expect("every struct should have a field list")
 864                     .fields()
 865                     .filter_map(|f| {
 866                         let ast_pat = f.pat()?;
 867                         let pat = self.collect_pat_(ast_pat);
 868                         let name = f.field_name()?.as_name();
 869                         Some(RecordFieldPat { name, pat })
 870                     })
 871                     .collect();
 872
 873                 let ellipsis = p
 874                     .record_pat_field_list()
 875                     .expect("every struct should have a field list")
 876                     .rest_pat()
 877                     .is_some();
 878
 879                 Pat::Record { path, args, ellipsis }
 880             }
 881             ast::Pat::SlicePat(p) => {
 882                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 883
 884                 // FIXME properly handle `RestPat`
 885                 Pat::Slice {
 886                     prefix: prefix.into_iter().map(|p| self.collect_pat_(p)).collect(),
 887                     slice: slice.map(|p| self.collect_pat_(p)),
 888                     suffix: suffix.into_iter().map(|p| self.collect_pat_(p)).collect(),
 889                 }
 890             }
 891             ast::Pat::LiteralPat(lit) => {
 892                 if let Some(ast_lit) = lit.literal() {
 893                     let expr = Expr::Literal(ast_lit.kind().into());
 894                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 895                     let expr_id = self.alloc_expr(expr, expr_ptr);
 896                     Pat::Lit(expr_id)
 897                 } else {
 898                     Pat::Missing
 899                 }
 900             }
 901             ast::Pat::RestPat(_) => {
 902                 // `RestPat` requires special handling and should not be mapped
 903                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 904                 // when `RestPat` is mapped to `Pat`, which can easily happen
 905                 // when the source code being analyzed has a malformed pattern
 906                 // which includes `..` in a place where it isn't valid.
 907
 908                 Pat::Missing
 909             }
 910             ast::Pat::BoxPat(boxpat) => {
 911                 let inner = self.collect_pat_opt_(boxpat.pat());
 912                 Pat::Box { inner }
 913             }
 914             ast::Pat::ConstBlockPat(const_block_pat) => {
 915                 if let Some(expr) = const_block_pat.block_expr() {
 916                     let expr_id = self.collect_block(expr);
 917                     Pat::ConstBlock(expr_id)
 918                 } else {
 919                     Pat::Missing
 920                 }
 921             }
 922             ast::Pat::MacroPat(mac) => match mac.macro_call() {
 923                 Some(call) => {
 924                     let macro_ptr = AstPtr::new(&call);
 925                     let src = self.expander.to_source(Either::Left(AstPtr::new(&pat)));
 926                     let pat =
 927                         self.collect_macro_call(call, macro_ptr, true, |this, expanded_pat| {
 928                             this.collect_pat_opt_(expanded_pat)
 929                         });
 930                     self.source_map.pat_map.insert(src, pat);
 931                     return pat;
 932                 }
 933                 None => Pat::Missing,
 934             },
 935             // FIXME: implement
 936             ast::Pat::RangePat(_) => Pat::Missing,
 937         };
 938         let ptr = AstPtr::new(&pat);
 939         self.alloc_pat(pattern, Either::Left(ptr))
 940     }
 941
 942     fn collect_pat_opt_(&mut self, pat: Option<ast::Pat>) -> PatId {
 943         match pat {
 944             Some(pat) => self.collect_pat_(pat),
 945             None => self.missing_pat(),
 946         }
 947     }
 948
 949     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Box<[PatId]>, Option<usize>) {
 950         // Find the location of the `..`, if there is one. Note that we do not
 951         // consider the possibility of there being multiple `..` here.
 952         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 953         // We want to skip the `..` pattern here, since we account for it above.
 954         let args = args
 955             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 956             .map(|p| self.collect_pat_(p))
 957             .collect();
 958
 959         (args, ellipsis)
 960     }
 961
 962     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 963     /// not.
 964     fn check_cfg(&mut self, owner: &dyn ast::HasAttrs) -> Option<()> {
 965         match self.expander.parse_attrs(self.db, owner).cfg() {
 966             Some(cfg) => {
 967                 if self.expander.cfg_options().check(&cfg) != Some(false) {
 968                     return Some(());
 969                 }
 970
 971                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode {
 972                     node: InFile::new(
 973                         self.expander.current_file_id,
 974                         SyntaxNodePtr::new(owner.syntax()),
 975                     ),
 976                     cfg,
 977                     opts: self.expander.cfg_options().clone(),
 978                 });
 979
 980                 None
 981             }
 982             None => Some(()),
 983         }
 984     }
 985 }
 986
 987 impl From<ast::LiteralKind> for Literal {
 988     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
 989         match ast_lit_kind {
 990             // FIXME: these should have actual values filled in, but unsure on perf impact
 991             LiteralKind::IntNumber(lit) => {
 992                 if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
 993                     Literal::Float(
 994                         FloatTypeWrapper::new(lit.float_value().unwrap_or(Default::default())),
 995                         builtin,
 996                     )
 997                 } else if let builtin @ Some(_) = lit.suffix().and_then(BuiltinInt::from_suffix) {
 998                     Literal::Int(lit.value().unwrap_or(0) as i128, builtin)
 999                 } else {
1000                     let builtin = lit.suffix().and_then(BuiltinUint::from_suffix);
1001                     Literal::Uint(lit.value().unwrap_or(0), builtin)
1002                 }
1003             }
1004             LiteralKind::FloatNumber(lit) => {
1005                 let ty = lit.suffix().and_then(BuiltinFloat::from_suffix);
1006                 Literal::Float(FloatTypeWrapper::new(lit.value().unwrap_or(Default::default())), ty)
1007             }
1008             LiteralKind::ByteString(bs) => {
1009                 let text = bs.value().map(Box::from).unwrap_or_else(Default::default);
1010                 Literal::ByteString(text)
1011             }
1012             LiteralKind::String(s) => {
1013                 let text = s.value().map(Box::from).unwrap_or_else(Default::default);
1014                 Literal::String(text)
1015             }
1016             LiteralKind::Byte(b) => {
1017                 Literal::Uint(b.value().unwrap_or_default() as u128, Some(BuiltinUint::U8))
1018             }
1019             LiteralKind::Char(c) => Literal::Char(c.value().unwrap_or_default()),
1020             LiteralKind::Bool(val) => Literal::Bool(val),
1021         }
1022     }
1023 }