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, FileAstId},
   9     hygiene::Hygiene,
  10     name::{name, AsName, Name},
  11     ExpandError, HirFileId, InFile,
  12 };
  13 use la_arena::Arena;
  14 use profile::Count;
  15 use syntax::{
  16     ast::{
  17         self, ArrayExprKind, AstChildren, HasArgList, HasLoopBody, HasName, LiteralKind,
  18         SlicePatComponents,
  19     },
  20     AstNode, AstPtr, SyntaxNodePtr,
  21 };
  22
  23 use crate::{
  24     adt::StructKind,
  25     body::{Body, BodySourceMap, Expander, LabelSource, PatPtr, SyntheticSyntax},
  26     body::{BodyDiagnostic, ExprSource, PatSource},
  27     builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint},
  28     db::DefDatabase,
  29     expr::{
  30         dummy_expr_id, Array, BindingAnnotation, Expr, ExprId, Label, LabelId, Literal, MatchArm,
  31         MatchGuard, Pat, PatId, RecordFieldPat, RecordLitField, Statement,
  32     },
  33     intern::Interned,
  34     item_scope::BuiltinShadowMode,
  35     path::{GenericArgs, Path},
  36     type_ref::{Mutability, Rawness, TypeRef},
  37     AdtId, BlockLoc, ModuleDefId, UnresolvedMacro,
  38 };
  39
  40 pub struct LowerCtx<'a> {
  41     pub db: &'a dyn DefDatabase,
  42     hygiene: Hygiene,
  43     file_id: Option<HirFileId>,
  44     source_ast_id_map: Option<Arc<AstIdMap>>,
  45 }
  46
  47 impl<'a> LowerCtx<'a> {
  48     pub fn new(db: &'a dyn DefDatabase, file_id: HirFileId) -> Self {
  49         LowerCtx {
  50             db,
  51             hygiene: Hygiene::new(db.upcast(), file_id),
  52             file_id: Some(file_id),
  53             source_ast_id_map: Some(db.ast_id_map(file_id)),
  54         }
  55     }
  56
  57     pub fn with_hygiene(db: &'a dyn DefDatabase, hygiene: &Hygiene) -> Self {
  58         LowerCtx { db, hygiene: hygiene.clone(), file_id: None, source_ast_id_map: None }
  59     }
  60
  61     pub(crate) fn hygiene(&self) -> &Hygiene {
  62         &self.hygiene
  63     }
  64
  65     pub(crate) fn file_id(&self) -> HirFileId {
  66         self.file_id.unwrap()
  67     }
  68
  69     pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
  70         Path::from_src(ast, self)
  71     }
  72
  73     pub(crate) fn ast_id<N: AstNode>(&self, item: &N) -> Option<FileAstId<N>> {
  74         self.source_ast_id_map.as_ref().map(|ast_id_map| ast_id_map.ast_id(item))
  75     }
  76 }
  77
  78 pub(super) fn lower(
  79     db: &dyn DefDatabase,
  80     expander: Expander,
  81     params: Option<ast::ParamList>,
  82     body: Option<ast::Expr>,
  83 ) -> (Body, BodySourceMap) {
  84     ExprCollector {
  85         db,
  86         source_map: BodySourceMap::default(),
  87         body: Body {
  88             exprs: Arena::default(),
  89             pats: Arena::default(),
  90             labels: Arena::default(),
  91             params: Vec::new(),
  92             body_expr: dummy_expr_id(),
  93             block_scopes: Vec::new(),
  94             _c: Count::new(),
  95         },
  96         expander,
  97         statements_in_scope: Vec::new(),
  98     }
  99     .collect(params, body)
 100 }
 101
 102 struct ExprCollector<'a> {
 103     db: &'a dyn DefDatabase,
 104     expander: Expander,
 105     body: Body,
 106     source_map: BodySourceMap,
 107     statements_in_scope: Vec<Statement>,
 108 }
 109
 110 impl ExprCollector<'_> {
 111     fn collect(
 112         mut self,
 113         param_list: Option<ast::ParamList>,
 114         body: Option<ast::Expr>,
 115     ) -> (Body, BodySourceMap) {
 116         if let Some(param_list) = param_list {
 117             if let Some(self_param) = param_list.self_param() {
 118                 let ptr = AstPtr::new(&self_param);
 119                 let param_pat = self.alloc_pat(
 120                     Pat::Bind {
 121                         name: name![self],
 122                         mode: BindingAnnotation::new(
 123                             self_param.mut_token().is_some() && self_param.amp_token().is_none(),
 124                             false,
 125                         ),
 126                         subpat: None,
 127                     },
 128                     Either::Right(ptr),
 129                 );
 130                 self.body.params.push(param_pat);
 131             }
 132
 133             for pat in param_list.params().filter_map(|param| param.pat()) {
 134                 let param_pat = self.collect_pat(pat);
 135                 self.body.params.push(param_pat);
 136             }
 137         };
 138
 139         self.body.body_expr = self.collect_expr_opt(body);
 140         (self.body, self.source_map)
 141     }
 142
 143     fn ctx(&self) -> LowerCtx<'_> {
 144         LowerCtx::new(self.db, self.expander.current_file_id)
 145     }
 146
 147     fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
 148         let src = self.expander.to_source(ptr);
 149         let id = self.make_expr(expr, Ok(src.clone()));
 150         self.source_map.expr_map.insert(src, id);
 151         id
 152     }
 153     // desugared exprs don't have ptr, that's wrong and should be fixed
 154     // somehow.
 155     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
 156         self.make_expr(expr, Err(SyntheticSyntax))
 157     }
 158     fn unit(&mut self) -> ExprId {
 159         self.alloc_expr_desugared(Expr::Tuple { exprs: Box::default() })
 160     }
 161     fn missing_expr(&mut self) -> ExprId {
 162         self.alloc_expr_desugared(Expr::Missing)
 163     }
 164     fn make_expr(&mut self, expr: Expr, src: Result<ExprSource, SyntheticSyntax>) -> ExprId {
 165         let id = self.body.exprs.alloc(expr);
 166         self.source_map.expr_map_back.insert(id, src);
 167         id
 168     }
 169
 170     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
 171         let src = self.expander.to_source(ptr);
 172         let id = self.make_pat(pat, Ok(src.clone()));
 173         self.source_map.pat_map.insert(src, id);
 174         id
 175     }
 176     fn missing_pat(&mut self) -> PatId {
 177         self.make_pat(Pat::Missing, Err(SyntheticSyntax))
 178     }
 179     fn make_pat(&mut self, pat: Pat, src: Result<PatSource, SyntheticSyntax>) -> PatId {
 180         let id = self.body.pats.alloc(pat);
 181         self.source_map.pat_map_back.insert(id, src);
 182         id
 183     }
 184
 185     fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
 186         let src = self.expander.to_source(ptr);
 187         let id = self.make_label(label, src.clone());
 188         self.source_map.label_map.insert(src, id);
 189         id
 190     }
 191     fn make_label(&mut self, label: Label, src: LabelSource) -> LabelId {
 192         let id = self.body.labels.alloc(label);
 193         self.source_map.label_map_back.insert(id, src);
 194         id
 195     }
 196
 197     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
 198         self.maybe_collect_expr(expr).unwrap_or_else(|| self.missing_expr())
 199     }
 200
 201     /// Returns `None` if and only if the expression is `#[cfg]`d out.
 202     fn maybe_collect_expr(&mut self, expr: ast::Expr) -> Option<ExprId> {
 203         let syntax_ptr = AstPtr::new(&expr);
 204         self.check_cfg(&expr)?;
 205
 206         Some(match expr {
 207             ast::Expr::IfExpr(e) => {
 208                 let then_branch = self.collect_block_opt(e.then_branch());
 209
 210                 let else_branch = e.else_branch().map(|b| match b {
 211                     ast::ElseBranch::Block(it) => self.collect_block(it),
 212                     ast::ElseBranch::IfExpr(elif) => {
 213                         let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
 214                         self.collect_expr(expr)
 215                     }
 216                 });
 217
 218                 let condition = match e.condition() {
 219                     None => self.missing_expr(),
 220                     Some(condition) => match condition.pat() {
 221                         None => self.collect_expr_opt(condition.expr()),
 222                         // if let -- desugar to match
 223                         Some(pat) => {
 224                             let pat = self.collect_pat(pat);
 225                             let match_expr = self.collect_expr_opt(condition.expr());
 226                             let placeholder_pat = self.missing_pat();
 227                             let arms = vec![
 228                                 MatchArm { pat, expr: then_branch, guard: None },
 229                                 MatchArm {
 230                                     pat: placeholder_pat,
 231                                     expr: else_branch.unwrap_or_else(|| self.unit()),
 232                                     guard: None,
 233                                 },
 234                             ]
 235                             .into();
 236                             return Some(
 237                                 self.alloc_expr(Expr::Match { expr: match_expr, arms }, syntax_ptr),
 238                             );
 239                         }
 240                     },
 241                 };
 242
 243                 self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
 244             }
 245             ast::Expr::BlockExpr(e) => match e.modifier() {
 246                 Some(ast::BlockModifier::Try(_)) => {
 247                     let body = self.collect_block(e);
 248                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
 249                 }
 250                 Some(ast::BlockModifier::Unsafe(_)) => {
 251                     let body = self.collect_block(e);
 252                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
 253                 }
 254                 // FIXME: we need to record these effects somewhere...
 255                 Some(ast::BlockModifier::Label(label)) => {
 256                     let label = self.collect_label(label);
 257                     let res = self.collect_block(e);
 258                     match &mut self.body.exprs[res] {
 259                         Expr::Block { label: block_label, .. } => {
 260                             *block_label = Some(label);
 261                         }
 262                         _ => unreachable!(),
 263                     }
 264                     res
 265                 }
 266                 Some(ast::BlockModifier::Async(_)) => {
 267                     let body = self.collect_block(e);
 268                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
 269                 }
 270                 Some(ast::BlockModifier::Const(_)) => {
 271                     let body = self.collect_block(e);
 272                     self.alloc_expr(Expr::Const { body }, syntax_ptr)
 273                 }
 274                 None => self.collect_block(e),
 275             },
 276             ast::Expr::LoopExpr(e) => {
 277                 let label = e.label().map(|label| self.collect_label(label));
 278                 let body = self.collect_block_opt(e.loop_body());
 279                 self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
 280             }
 281             ast::Expr::WhileExpr(e) => {
 282                 let label = e.label().map(|label| self.collect_label(label));
 283                 let body = self.collect_block_opt(e.loop_body());
 284
 285                 let condition = match e.condition() {
 286                     None => self.missing_expr(),
 287                     Some(condition) => match condition.pat() {
 288                         None => self.collect_expr_opt(condition.expr()),
 289                         // if let -- desugar to match
 290                         Some(pat) => {
 291                             cov_mark::hit!(infer_resolve_while_let);
 292                             let pat = self.collect_pat(pat);
 293                             let match_expr = self.collect_expr_opt(condition.expr());
 294                             let placeholder_pat = self.missing_pat();
 295                             let break_ =
 296                                 self.alloc_expr_desugared(Expr::Break { expr: None, label: None });
 297                             let arms = vec![
 298                                 MatchArm { pat, expr: body, guard: None },
 299                                 MatchArm { pat: placeholder_pat, expr: break_, guard: None },
 300                             ]
 301                             .into();
 302                             let match_expr =
 303                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
 304                             return Some(
 305                                 self.alloc_expr(Expr::Loop { body: match_expr, label }, syntax_ptr),
 306                             );
 307                         }
 308                     },
 309                 };
 310
 311                 self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
 312             }
 313             ast::Expr::ForExpr(e) => {
 314                 let label = e.label().map(|label| self.collect_label(label));
 315                 let iterable = self.collect_expr_opt(e.iterable());
 316                 let pat = self.collect_pat_opt(e.pat());
 317                 let body = self.collect_block_opt(e.loop_body());
 318                 self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
 319             }
 320             ast::Expr::CallExpr(e) => {
 321                 let callee = self.collect_expr_opt(e.expr());
 322                 let args = if let Some(arg_list) = e.arg_list() {
 323                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 324                 } else {
 325                     Box::default()
 326                 };
 327                 self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
 328             }
 329             ast::Expr::MethodCallExpr(e) => {
 330                 let receiver = self.collect_expr_opt(e.receiver());
 331                 let args = if let Some(arg_list) = e.arg_list() {
 332                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 333                 } else {
 334                     Box::default()
 335                 };
 336                 let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 337                 let generic_args = e
 338                     .generic_arg_list()
 339                     .and_then(|it| GenericArgs::from_ast(&self.ctx(), it))
 340                     .map(Box::new);
 341                 self.alloc_expr(
 342                     Expr::MethodCall { receiver, method_name, args, generic_args },
 343                     syntax_ptr,
 344                 )
 345             }
 346             ast::Expr::MatchExpr(e) => {
 347                 let expr = self.collect_expr_opt(e.expr());
 348                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
 349                     match_arm_list
 350                         .arms()
 351                         .filter_map(|arm| {
 352                             self.check_cfg(&arm).map(|()| MatchArm {
 353                                 pat: self.collect_pat_opt(arm.pat()),
 354                                 expr: self.collect_expr_opt(arm.expr()),
 355                                 guard: arm.guard().map(|guard| match guard.pat() {
 356                                     Some(pat) => MatchGuard::IfLet {
 357                                         pat: self.collect_pat(pat),
 358                                         expr: self.collect_expr_opt(guard.expr()),
 359                                     },
 360                                     None => {
 361                                         MatchGuard::If { expr: self.collect_expr_opt(guard.expr()) }
 362                                     }
 363                                 }),
 364                             })
 365                         })
 366                         .collect()
 367                 } else {
 368                     Box::default()
 369                 };
 370                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
 371             }
 372             ast::Expr::PathExpr(e) => {
 373                 let path = e
 374                     .path()
 375                     .and_then(|path| self.expander.parse_path(self.db, path))
 376                     .map(Expr::Path)
 377                     .unwrap_or(Expr::Missing);
 378                 self.alloc_expr(path, syntax_ptr)
 379             }
 380             ast::Expr::ContinueExpr(e) => self.alloc_expr(
 381                 Expr::Continue { label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 382                 syntax_ptr,
 383             ),
 384             ast::Expr::BreakExpr(e) => {
 385                 let expr = e.expr().map(|e| self.collect_expr(e));
 386                 self.alloc_expr(
 387                     Expr::Break { expr, label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 388                     syntax_ptr,
 389                 )
 390             }
 391             ast::Expr::ParenExpr(e) => {
 392                 let inner = self.collect_expr_opt(e.expr());
 393                 // make the paren expr point to the inner expression as well
 394                 let src = self.expander.to_source(syntax_ptr);
 395                 self.source_map.expr_map.insert(src, inner);
 396                 inner
 397             }
 398             ast::Expr::ReturnExpr(e) => {
 399                 let expr = e.expr().map(|e| self.collect_expr(e));
 400                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
 401             }
 402             ast::Expr::YieldExpr(e) => {
 403                 let expr = e.expr().map(|e| self.collect_expr(e));
 404                 self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
 405             }
 406             ast::Expr::RecordExpr(e) => {
 407                 let path =
 408                     e.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 409                 let record_lit = if let Some(nfl) = e.record_expr_field_list() {
 410                     let fields = nfl
 411                         .fields()
 412                         .filter_map(|field| {
 413                             self.check_cfg(&field)?;
 414
 415                             let name = field.field_name()?.as_name();
 416
 417                             let expr = match field.expr() {
 418                                 Some(e) => self.collect_expr(e),
 419                                 None => self.missing_expr(),
 420                             };
 421                             let src = self.expander.to_source(AstPtr::new(&field));
 422                             self.source_map.field_map.insert(src.clone(), expr);
 423                             self.source_map.field_map_back.insert(expr, src);
 424                             Some(RecordLitField { name, expr })
 425                         })
 426                         .collect();
 427                     let spread = nfl.spread().map(|s| self.collect_expr(s));
 428                     Expr::RecordLit { path, fields, spread }
 429                 } else {
 430                     Expr::RecordLit { path, fields: Box::default(), spread: None }
 431                 };
 432
 433                 self.alloc_expr(record_lit, syntax_ptr)
 434             }
 435             ast::Expr::FieldExpr(e) => {
 436                 let expr = self.collect_expr_opt(e.expr());
 437                 let name = match e.field_access() {
 438                     Some(kind) => kind.as_name(),
 439                     _ => Name::missing(),
 440                 };
 441                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
 442             }
 443             ast::Expr::AwaitExpr(e) => {
 444                 let expr = self.collect_expr_opt(e.expr());
 445                 self.alloc_expr(Expr::Await { expr }, syntax_ptr)
 446             }
 447             ast::Expr::TryExpr(e) => {
 448                 let expr = self.collect_expr_opt(e.expr());
 449                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
 450             }
 451             ast::Expr::CastExpr(e) => {
 452                 let expr = self.collect_expr_opt(e.expr());
 453                 let type_ref = Interned::new(TypeRef::from_ast_opt(&self.ctx(), e.ty()));
 454                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
 455             }
 456             ast::Expr::RefExpr(e) => {
 457                 let expr = self.collect_expr_opt(e.expr());
 458                 let raw_tok = e.raw_token().is_some();
 459                 let mutability = if raw_tok {
 460                     if e.mut_token().is_some() {
 461                         Mutability::Mut
 462                     } else if e.const_token().is_some() {
 463                         Mutability::Shared
 464                     } else {
 465                         unreachable!("parser only remaps to raw_token() if matching mutability token follows")
 466                     }
 467                 } else {
 468                     Mutability::from_mutable(e.mut_token().is_some())
 469                 };
 470                 let rawness = Rawness::from_raw(raw_tok);
 471                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
 472             }
 473             ast::Expr::PrefixExpr(e) => {
 474                 let expr = self.collect_expr_opt(e.expr());
 475                 match e.op_kind() {
 476                     Some(op) => self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr),
 477                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 478                 }
 479             }
 480             ast::Expr::ClosureExpr(e) => {
 481                 let mut args = Vec::new();
 482                 let mut arg_types = Vec::new();
 483                 if let Some(pl) = e.param_list() {
 484                     for param in pl.params() {
 485                         let pat = self.collect_pat_opt(param.pat());
 486                         let type_ref =
 487                             param.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 488                         args.push(pat);
 489                         arg_types.push(type_ref);
 490                     }
 491                 }
 492                 let ret_type = e
 493                     .ret_type()
 494                     .and_then(|r| r.ty())
 495                     .map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 496                 let body = self.collect_expr_opt(e.body());
 497                 self.alloc_expr(
 498                     Expr::Lambda { args: args.into(), arg_types: arg_types.into(), ret_type, body },
 499                     syntax_ptr,
 500                 )
 501             }
 502             ast::Expr::BinExpr(e) => {
 503                 let lhs = self.collect_expr_opt(e.lhs());
 504                 let rhs = self.collect_expr_opt(e.rhs());
 505                 let op = e.op_kind();
 506                 self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
 507             }
 508             ast::Expr::TupleExpr(e) => {
 509                 let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect();
 510                 self.alloc_expr(Expr::Tuple { exprs }, syntax_ptr)
 511             }
 512             ast::Expr::BoxExpr(e) => {
 513                 let expr = self.collect_expr_opt(e.expr());
 514                 self.alloc_expr(Expr::Box { expr }, syntax_ptr)
 515             }
 516
 517             ast::Expr::ArrayExpr(e) => {
 518                 let kind = e.kind();
 519
 520                 match kind {
 521                     ArrayExprKind::ElementList(e) => {
 522                         let exprs = e.map(|expr| self.collect_expr(expr)).collect();
 523                         self.alloc_expr(Expr::Array(Array::ElementList(exprs)), syntax_ptr)
 524                     }
 525                     ArrayExprKind::Repeat { initializer, repeat } => {
 526                         let initializer = self.collect_expr_opt(initializer);
 527                         let repeat = self.collect_expr_opt(repeat);
 528                         self.alloc_expr(
 529                             Expr::Array(Array::Repeat { initializer, repeat }),
 530                             syntax_ptr,
 531                         )
 532                     }
 533                 }
 534             }
 535
 536             ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
 537             ast::Expr::IndexExpr(e) => {
 538                 let base = self.collect_expr_opt(e.base());
 539                 let index = self.collect_expr_opt(e.index());
 540                 self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
 541             }
 542             ast::Expr::RangeExpr(e) => {
 543                 let lhs = e.start().map(|lhs| self.collect_expr(lhs));
 544                 let rhs = e.end().map(|rhs| self.collect_expr(rhs));
 545                 match e.op_kind() {
 546                     Some(range_type) => {
 547                         self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
 548                     }
 549                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 550                 }
 551             }
 552             ast::Expr::MacroCall(e) => {
 553                 let macro_ptr = AstPtr::new(&e);
 554                 let mut ids = vec![];
 555                 self.collect_macro_call(e, macro_ptr, |this, expansion| {
 556                     ids.push(match expansion {
 557                         Some(it) => this.collect_expr(it),
 558                         None => this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
 559                     })
 560                 });
 561                 ids[0]
 562             }
 563             ast::Expr::MacroStmts(e) => {
 564                 e.statements().for_each(|s| self.collect_stmt(s));
 565                 let tail = e
 566                     .expr()
 567                     .map(|e| self.collect_expr(e))
 568                     .unwrap_or_else(|| self.alloc_expr(Expr::Missing, syntax_ptr.clone()));
 569
 570                 self.alloc_expr(Expr::MacroStmts { tail }, syntax_ptr)
 571             }
 572         })
 573     }
 574
 575     fn collect_macro_call<F: FnMut(&mut Self, Option<T>), T: ast::AstNode>(
 576         &mut self,
 577         e: ast::MacroCall,
 578         syntax_ptr: AstPtr<ast::MacroCall>,
 579         mut collector: F,
 580     ) {
 581         // File containing the macro call. Expansion errors will be attached here.
 582         let outer_file = self.expander.current_file_id;
 583
 584         let macro_call = self.expander.to_source(AstPtr::new(&e));
 585         let res = self.expander.enter_expand(self.db, e);
 586
 587         let res = match res {
 588             Ok(res) => res,
 589             Err(UnresolvedMacro { path }) => {
 590                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall {
 591                     node: InFile::new(outer_file, syntax_ptr),
 592                     path,
 593                 });
 594                 collector(self, None);
 595                 return;
 596             }
 597         };
 598
 599         match &res.err {
 600             Some(ExpandError::UnresolvedProcMacro) => {
 601                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro {
 602                     node: InFile::new(outer_file, syntax_ptr),
 603                 });
 604             }
 605             Some(err) => {
 606                 self.source_map.diagnostics.push(BodyDiagnostic::MacroError {
 607                     node: InFile::new(outer_file, syntax_ptr),
 608                     message: err.to_string(),
 609                 });
 610             }
 611             None => {}
 612         }
 613
 614         match res.value {
 615             Some((mark, expansion)) => {
 616                 self.source_map.expansions.insert(macro_call, self.expander.current_file_id);
 617
 618                 let id = collector(self, Some(expansion));
 619                 self.expander.exit(self.db, mark);
 620                 id
 621             }
 622             None => collector(self, None),
 623         }
 624     }
 625
 626     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 627         match expr {
 628             Some(expr) => self.collect_expr(expr),
 629             None => self.missing_expr(),
 630         }
 631     }
 632
 633     fn collect_stmt(&mut self, s: ast::Stmt) {
 634         match s {
 635             ast::Stmt::LetStmt(stmt) => {
 636                 if self.check_cfg(&stmt).is_none() {
 637                     return;
 638                 }
 639                 let pat = self.collect_pat_opt(stmt.pat());
 640                 let type_ref =
 641                     stmt.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 642                 let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 643                 let else_branch = stmt
 644                     .let_else()
 645                     .and_then(|let_else| let_else.block_expr())
 646                     .map(|block| self.collect_block(block));
 647                 self.statements_in_scope.push(Statement::Let {
 648                     pat,
 649                     type_ref,
 650                     initializer,
 651                     else_branch,
 652                 });
 653             }
 654             ast::Stmt::ExprStmt(stmt) => {
 655                 if let Some(expr) = stmt.expr() {
 656                     if self.check_cfg(&expr).is_none() {
 657                         return;
 658                     }
 659                 }
 660                 let has_semi = stmt.semicolon_token().is_some();
 661                 // Note that macro could be expended to multiple statements
 662                 if let Some(ast::Expr::MacroCall(m)) = stmt.expr() {
 663                     let macro_ptr = AstPtr::new(&m);
 664                     let syntax_ptr = AstPtr::new(&stmt.expr().unwrap());
 665
 666                     self.collect_macro_call(m, macro_ptr, |this, expansion| match expansion {
 667                         Some(expansion) => {
 668                             let statements: ast::MacroStmts = expansion;
 669
 670                             statements.statements().for_each(|stmt| this.collect_stmt(stmt));
 671                             if let Some(expr) = statements.expr() {
 672                                 let expr = this.collect_expr(expr);
 673                                 this.statements_in_scope.push(Statement::Expr { expr, has_semi });
 674                             }
 675                         }
 676                         None => {
 677                             let expr = this.alloc_expr(Expr::Missing, syntax_ptr.clone());
 678                             this.statements_in_scope.push(Statement::Expr { expr, has_semi });
 679                         }
 680                     });
 681                 } else {
 682                     let expr = self.collect_expr_opt(stmt.expr());
 683                     self.statements_in_scope.push(Statement::Expr { expr, has_semi });
 684                 }
 685             }
 686             ast::Stmt::Item(item) => {
 687                 self.check_cfg(&item);
 688             }
 689         }
 690     }
 691
 692     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 693         let ast_id = self.expander.ast_id(&block);
 694         let block_loc =
 695             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
 696         let block_id = self.db.intern_block(block_loc);
 697
 698         let (module, def_map) = match self.db.block_def_map(block_id) {
 699             Some(def_map) => {
 700                 self.body.block_scopes.push(block_id);
 701                 (def_map.root(), def_map)
 702             }
 703             None => (self.expander.module, self.expander.def_map.clone()),
 704         };
 705         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 706         let prev_local_module = mem::replace(&mut self.expander.module, module);
 707         let prev_statements = std::mem::take(&mut self.statements_in_scope);
 708
 709         block.statements().for_each(|s| self.collect_stmt(s));
 710         block.tail_expr().and_then(|e| {
 711             let expr = self.maybe_collect_expr(e)?;
 712             self.statements_in_scope.push(Statement::Expr { expr, has_semi: false });
 713             Some(())
 714         });
 715
 716         let mut tail = None;
 717         if let Some(Statement::Expr { expr, has_semi: false }) = self.statements_in_scope.last() {
 718             tail = Some(*expr);
 719             self.statements_in_scope.pop();
 720         }
 721         let tail = tail;
 722         let statements = std::mem::replace(&mut self.statements_in_scope, prev_statements).into();
 723         let syntax_node_ptr = AstPtr::new(&block.into());
 724         let expr_id = self.alloc_expr(
 725             Expr::Block { id: block_id, statements, tail, label: None },
 726             syntax_node_ptr,
 727         );
 728
 729         self.expander.def_map = prev_def_map;
 730         self.expander.module = prev_local_module;
 731         expr_id
 732     }
 733
 734     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 735         match expr {
 736             Some(block) => self.collect_block(block),
 737             None => self.missing_expr(),
 738         }
 739     }
 740
 741     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 742         let label = Label {
 743             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 744         };
 745         self.alloc_label(label, AstPtr::new(&ast_label))
 746     }
 747
 748     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 749         let pattern = match &pat {
 750             ast::Pat::IdentPat(bp) => {
 751                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 752                 let annotation =
 753                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 754                 let subpat = bp.pat().map(|subpat| self.collect_pat(subpat));
 755                 if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 756                     // This could also be a single-segment path pattern. To
 757                     // decide that, we need to try resolving the name.
 758                     let (resolved, _) = self.expander.def_map.resolve_path(
 759                         self.db,
 760                         self.expander.module,
 761                         &name.clone().into(),
 762                         BuiltinShadowMode::Other,
 763                     );
 764                     match resolved.take_values() {
 765                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 766                         Some(ModuleDefId::EnumVariantId(_)) => {
 767                             // this is only really valid for unit variants, but
 768                             // shadowing other enum variants with a pattern is
 769                             // an error anyway
 770                             Pat::Path(name.into())
 771                         }
 772                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 773                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 774                         {
 775                             // Funnily enough, record structs *can* be shadowed
 776                             // by pattern bindings (but unit or tuple structs
 777                             // can't).
 778                             Pat::Path(name.into())
 779                         }
 780                         // shadowing statics is an error as well, so we just ignore that case here
 781                         _ => Pat::Bind { name, mode: annotation, subpat },
 782                     }
 783                 } else {
 784                     Pat::Bind { name, mode: annotation, subpat }
 785                 }
 786             }
 787             ast::Pat::TupleStructPat(p) => {
 788                 let path =
 789                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 790                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 791                 Pat::TupleStruct { path, args, ellipsis }
 792             }
 793             ast::Pat::RefPat(p) => {
 794                 let pat = self.collect_pat_opt(p.pat());
 795                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 796                 Pat::Ref { pat, mutability }
 797             }
 798             ast::Pat::PathPat(p) => {
 799                 let path =
 800                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 801                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 802             }
 803             ast::Pat::OrPat(p) => {
 804                 let pats = p.pats().map(|p| self.collect_pat(p)).collect();
 805                 Pat::Or(pats)
 806             }
 807             ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat()),
 808             ast::Pat::TuplePat(p) => {
 809                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 810                 Pat::Tuple { args, ellipsis }
 811             }
 812             ast::Pat::WildcardPat(_) => Pat::Wild,
 813             ast::Pat::RecordPat(p) => {
 814                 let path =
 815                     p.path().and_then(|path| self.expander.parse_path(self.db, path)).map(Box::new);
 816                 let args = p
 817                     .record_pat_field_list()
 818                     .expect("every struct should have a field list")
 819                     .fields()
 820                     .filter_map(|f| {
 821                         let ast_pat = f.pat()?;
 822                         let pat = self.collect_pat(ast_pat);
 823                         let name = f.field_name()?.as_name();
 824                         Some(RecordFieldPat { name, pat })
 825                     })
 826                     .collect();
 827
 828                 let ellipsis = p
 829                     .record_pat_field_list()
 830                     .expect("every struct should have a field list")
 831                     .rest_pat()
 832                     .is_some();
 833
 834                 Pat::Record { path, args, ellipsis }
 835             }
 836             ast::Pat::SlicePat(p) => {
 837                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 838
 839                 // FIXME properly handle `RestPat`
 840                 Pat::Slice {
 841                     prefix: prefix.into_iter().map(|p| self.collect_pat(p)).collect(),
 842                     slice: slice.map(|p| self.collect_pat(p)),
 843                     suffix: suffix.into_iter().map(|p| self.collect_pat(p)).collect(),
 844                 }
 845             }
 846             ast::Pat::LiteralPat(lit) => {
 847                 if let Some(ast_lit) = lit.literal() {
 848                     let expr = Expr::Literal(ast_lit.kind().into());
 849                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 850                     let expr_id = self.alloc_expr(expr, expr_ptr);
 851                     Pat::Lit(expr_id)
 852                 } else {
 853                     Pat::Missing
 854                 }
 855             }
 856             ast::Pat::RestPat(_) => {
 857                 // `RestPat` requires special handling and should not be mapped
 858                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 859                 // when `RestPat` is mapped to `Pat`, which can easily happen
 860                 // when the source code being analyzed has a malformed pattern
 861                 // which includes `..` in a place where it isn't valid.
 862
 863                 Pat::Missing
 864             }
 865             ast::Pat::BoxPat(boxpat) => {
 866                 let inner = self.collect_pat_opt(boxpat.pat());
 867                 Pat::Box { inner }
 868             }
 869             ast::Pat::ConstBlockPat(const_block_pat) => {
 870                 if let Some(expr) = const_block_pat.block_expr() {
 871                     let expr_id = self.collect_block(expr);
 872                     Pat::ConstBlock(expr_id)
 873                 } else {
 874                     Pat::Missing
 875                 }
 876             }
 877             ast::Pat::MacroPat(mac) => match mac.macro_call() {
 878                 Some(call) => {
 879                     let macro_ptr = AstPtr::new(&call);
 880                     let mut pat = None;
 881                     self.collect_macro_call(call, macro_ptr, |this, expanded_pat| {
 882                         pat = Some(this.collect_pat_opt(expanded_pat));
 883                     });
 884
 885                     match pat {
 886                         Some(pat) => return pat,
 887                         None => Pat::Missing,
 888                     }
 889                 }
 890                 None => Pat::Missing,
 891             },
 892             // FIXME: implement
 893             ast::Pat::RangePat(_) => Pat::Missing,
 894         };
 895         let ptr = AstPtr::new(&pat);
 896         self.alloc_pat(pattern, Either::Left(ptr))
 897     }
 898
 899     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 900         match pat {
 901             Some(pat) => self.collect_pat(pat),
 902             None => self.missing_pat(),
 903         }
 904     }
 905
 906     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Box<[PatId]>, Option<usize>) {
 907         // Find the location of the `..`, if there is one. Note that we do not
 908         // consider the possibility of there being multiple `..` here.
 909         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 910         // We want to skip the `..` pattern here, since we account for it above.
 911         let args = args
 912             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 913             .map(|p| self.collect_pat(p))
 914             .collect();
 915
 916         (args, ellipsis)
 917     }
 918
 919     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 920     /// not.
 921     fn check_cfg(&mut self, owner: &dyn ast::HasAttrs) -> Option<()> {
 922         match self.expander.parse_attrs(self.db, owner).cfg() {
 923             Some(cfg) => {
 924                 if self.expander.cfg_options().check(&cfg) != Some(false) {
 925                     return Some(());
 926                 }
 927
 928                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode {
 929                     node: InFile::new(
 930                         self.expander.current_file_id,
 931                         SyntaxNodePtr::new(owner.syntax()),
 932                     ),
 933                     cfg,
 934                     opts: self.expander.cfg_options().clone(),
 935                 });
 936
 937                 None
 938             }
 939             None => Some(()),
 940         }
 941     }
 942 }
 943
 944 impl From<ast::LiteralKind> for Literal {
 945     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
 946         match ast_lit_kind {
 947             // FIXME: these should have actual values filled in, but unsure on perf impact
 948             LiteralKind::IntNumber(lit) => {
 949                 if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
 950                     Literal::Float(Default::default(), builtin)
 951                 } else if let builtin @ Some(_) =
 952                     lit.suffix().and_then(|it| BuiltinInt::from_suffix(it))
 953                 {
 954                     Literal::Int(lit.value().unwrap_or(0) as i128, builtin)
 955                 } else {
 956                     let builtin = lit.suffix().and_then(|it| BuiltinUint::from_suffix(it));
 957                     Literal::Uint(lit.value().unwrap_or(0), builtin)
 958                 }
 959             }
 960             LiteralKind::FloatNumber(lit) => {
 961                 let ty = lit.suffix().and_then(|it| BuiltinFloat::from_suffix(it));
 962                 Literal::Float(Default::default(), ty)
 963             }
 964             LiteralKind::ByteString(bs) => {
 965                 let text = bs.value().map(Box::from).unwrap_or_else(Default::default);
 966                 Literal::ByteString(text)
 967             }
 968             LiteralKind::String(_) => Literal::String(Default::default()),
 969             LiteralKind::Byte => Literal::Uint(Default::default(), Some(BuiltinUint::U8)),
 970             LiteralKind::Bool(val) => Literal::Bool(val),
 971             LiteralKind::Char => Literal::Char(Default::default()),
 972         }
 973     }
 974 }