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,
  12 };
  13 use la_arena::Arena;
  14 use profile::Count;
  15 use syntax::{
  16     ast::{
  17         self, ArgListOwner, ArrayExprKind, AstChildren, LiteralKind, LoopBodyOwner, NameOwner,
  18         SlicePatComponents,
  19     },
  20     AstNode, AstPtr, SyntaxNodePtr,
  21 };
  22
  23 use crate::{
  24     adt::StructKind,
  25     body::{Body, BodySourceMap, Expander, LabelSource, PatPtr, SyntheticSyntax},
  26     builtin_type::{BuiltinFloat, BuiltinInt, BuiltinUint},
  27     db::DefDatabase,
  28     diagnostics::{InactiveCode, MacroError, UnresolvedMacroCall, UnresolvedProcMacro},
  29     expr::{
  30         dummy_expr_id, ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Label,
  31         LabelId, Literal, LogicOp, MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField,
  32         Statement,
  33     },
  34     intern::Interned,
  35     item_scope::BuiltinShadowMode,
  36     path::{GenericArgs, Path},
  37     type_ref::{Mutability, Rawness, TypeRef},
  38     AdtId, BlockLoc, ModuleDefId, UnresolvedMacro,
  39 };
  40
  41 use super::{diagnostics::BodyDiagnostic, ExprSource, PatSource};
  42
  43 pub struct LowerCtx {
  44     hygiene: Hygiene,
  45     file_id: Option<HirFileId>,
  46     source_ast_id_map: Option<Arc<AstIdMap>>,
  47 }
  48
  49 impl LowerCtx {
  50     pub fn new(db: &dyn DefDatabase, file_id: HirFileId) -> Self {
  51         LowerCtx {
  52             hygiene: Hygiene::new(db.upcast(), file_id),
  53             file_id: Some(file_id),
  54             source_ast_id_map: Some(db.ast_id_map(file_id)),
  55         }
  56     }
  57
  58     pub fn with_hygiene(hygiene: &Hygiene) -> Self {
  59         LowerCtx { hygiene: hygiene.clone(), file_id: None, source_ast_id_map: None }
  60     }
  61
  62     pub(crate) fn hygiene(&self) -> &Hygiene {
  63         &self.hygiene
  64     }
  65
  66     pub(crate) fn file_id(&self) -> HirFileId {
  67         self.file_id.unwrap()
  68     }
  69
  70     pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
  71         Path::from_src(ast, self)
  72     }
  73
  74     pub(crate) fn ast_id<N: AstNode>(&self, item: &N) -> Option<FileAstId<N>> {
  75         self.source_ast_id_map.as_ref().map(|ast_id_map| ast_id_map.ast_id(item))
  76     }
  77 }
  78
  79 pub(super) fn lower(
  80     db: &dyn DefDatabase,
  81     expander: Expander,
  82     params: Option<ast::ParamList>,
  83     body: Option<ast::Expr>,
  84 ) -> (Body, BodySourceMap) {
  85     ExprCollector {
  86         db,
  87         source_map: BodySourceMap::default(),
  88         body: Body {
  89             exprs: Arena::default(),
  90             pats: Arena::default(),
  91             labels: Arena::default(),
  92             params: Vec::new(),
  93             body_expr: dummy_expr_id(),
  94             block_scopes: Vec::new(),
  95             _c: Count::new(),
  96         },
  97         expander,
  98         statements_in_scope: Vec::new(),
  99     }
 100     .collect(params, body)
 101 }
 102
 103 struct ExprCollector<'a> {
 104     db: &'a dyn DefDatabase,
 105     expander: Expander,
 106     body: Body,
 107     source_map: BodySourceMap,
 108     statements_in_scope: Vec<Statement>,
 109 }
 110
 111 impl ExprCollector<'_> {
 112     fn collect(
 113         mut self,
 114         param_list: Option<ast::ParamList>,
 115         body: Option<ast::Expr>,
 116     ) -> (Body, BodySourceMap) {
 117         if let Some(param_list) = param_list {
 118             if let Some(self_param) = param_list.self_param() {
 119                 let ptr = AstPtr::new(&self_param);
 120                 let param_pat = self.alloc_pat(
 121                     Pat::Bind {
 122                         name: name![self],
 123                         mode: BindingAnnotation::new(
 124                             self_param.mut_token().is_some() && self_param.amp_token().is_none(),
 125                             false,
 126                         ),
 127                         subpat: None,
 128                     },
 129                     Either::Right(ptr),
 130                 );
 131                 self.body.params.push(param_pat);
 132             }
 133
 134             for param in param_list.params() {
 135                 let pat = match param.pat() {
 136                     None => continue,
 137                     Some(pat) => pat,
 138                 };
 139                 let param_pat = self.collect_pat(pat);
 140                 self.body.params.push(param_pat);
 141             }
 142         };
 143
 144         self.body.body_expr = self.collect_expr_opt(body);
 145         (self.body, self.source_map)
 146     }
 147
 148     fn ctx(&self) -> LowerCtx {
 149         LowerCtx::new(self.db, self.expander.current_file_id)
 150     }
 151
 152     fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
 153         let src = self.expander.to_source(ptr);
 154         let id = self.make_expr(expr, Ok(src.clone()));
 155         self.source_map.expr_map.insert(src, id);
 156         id
 157     }
 158     // desugared exprs don't have ptr, that's wrong and should be fixed
 159     // somehow.
 160     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
 161         self.make_expr(expr, Err(SyntheticSyntax))
 162     }
 163     fn unit(&mut self) -> ExprId {
 164         self.alloc_expr_desugared(Expr::Tuple { exprs: Vec::new() })
 165     }
 166     fn missing_expr(&mut self) -> ExprId {
 167         self.alloc_expr_desugared(Expr::Missing)
 168     }
 169     fn make_expr(&mut self, expr: Expr, src: Result<ExprSource, SyntheticSyntax>) -> ExprId {
 170         let id = self.body.exprs.alloc(expr);
 171         self.source_map.expr_map_back.insert(id, src);
 172         id
 173     }
 174
 175     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
 176         let src = self.expander.to_source(ptr);
 177         let id = self.make_pat(pat, Ok(src.clone()));
 178         self.source_map.pat_map.insert(src, id);
 179         id
 180     }
 181     fn missing_pat(&mut self) -> PatId {
 182         self.make_pat(Pat::Missing, Err(SyntheticSyntax))
 183     }
 184     fn make_pat(&mut self, pat: Pat, src: Result<PatSource, SyntheticSyntax>) -> PatId {
 185         let id = self.body.pats.alloc(pat);
 186         self.source_map.pat_map_back.insert(id, src);
 187         id
 188     }
 189
 190     fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
 191         let src = self.expander.to_source(ptr);
 192         let id = self.make_label(label, src.clone());
 193         self.source_map.label_map.insert(src, id);
 194         id
 195     }
 196     fn make_label(&mut self, label: Label, src: LabelSource) -> LabelId {
 197         let id = self.body.labels.alloc(label);
 198         self.source_map.label_map_back.insert(id, src);
 199         id
 200     }
 201
 202     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
 203         self.maybe_collect_expr(expr).unwrap_or_else(|| self.missing_expr())
 204     }
 205
 206     /// Returns `None` if the expression is `#[cfg]`d out.
 207     fn maybe_collect_expr(&mut self, expr: ast::Expr) -> Option<ExprId> {
 208         let syntax_ptr = AstPtr::new(&expr);
 209         self.check_cfg(&expr)?;
 210
 211         Some(match expr {
 212             ast::Expr::IfExpr(e) => {
 213                 let then_branch = self.collect_block_opt(e.then_branch());
 214
 215                 let else_branch = e.else_branch().map(|b| match b {
 216                     ast::ElseBranch::Block(it) => self.collect_block(it),
 217                     ast::ElseBranch::IfExpr(elif) => {
 218                         let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
 219                         self.collect_expr(expr)
 220                     }
 221                 });
 222
 223                 let condition = match e.condition() {
 224                     None => self.missing_expr(),
 225                     Some(condition) => match condition.pat() {
 226                         None => self.collect_expr_opt(condition.expr()),
 227                         // if let -- desugar to match
 228                         Some(pat) => {
 229                             let pat = self.collect_pat(pat);
 230                             let match_expr = self.collect_expr_opt(condition.expr());
 231                             let placeholder_pat = self.missing_pat();
 232                             let arms = vec![
 233                                 MatchArm { pat, expr: then_branch, guard: None },
 234                                 MatchArm {
 235                                     pat: placeholder_pat,
 236                                     expr: else_branch.unwrap_or_else(|| self.unit()),
 237                                     guard: None,
 238                                 },
 239                             ];
 240                             return Some(
 241                                 self.alloc_expr(Expr::Match { expr: match_expr, arms }, syntax_ptr),
 242                             );
 243                         }
 244                     },
 245                 };
 246
 247                 self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
 248             }
 249             ast::Expr::EffectExpr(e) => match e.effect() {
 250                 ast::Effect::Try(_) => {
 251                     let body = self.collect_block_opt(e.block_expr());
 252                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
 253                 }
 254                 ast::Effect::Unsafe(_) => {
 255                     let body = self.collect_block_opt(e.block_expr());
 256                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
 257                 }
 258                 // FIXME: we need to record these effects somewhere...
 259                 ast::Effect::Label(label) => {
 260                     let label = self.collect_label(label);
 261                     match e.block_expr() {
 262                         Some(block) => {
 263                             let res = self.collect_block(block);
 264                             match &mut self.body.exprs[res] {
 265                                 Expr::Block { label: block_label, .. } => {
 266                                     *block_label = Some(label);
 267                                 }
 268                                 _ => unreachable!(),
 269                             }
 270                             res
 271                         }
 272                         None => self.missing_expr(),
 273                     }
 274                 }
 275                 // FIXME: we need to record these effects somewhere...
 276                 ast::Effect::Async(_) => {
 277                     let body = self.collect_block_opt(e.block_expr());
 278                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
 279                 }
 280                 ast::Effect::Const(_) => {
 281                     let body = self.collect_block_opt(e.block_expr());
 282                     self.alloc_expr(Expr::Const { body }, syntax_ptr)
 283                 }
 284             },
 285             ast::Expr::BlockExpr(e) => self.collect_block(e),
 286             ast::Expr::LoopExpr(e) => {
 287                 let label = e.label().map(|label| self.collect_label(label));
 288                 let body = self.collect_block_opt(e.loop_body());
 289                 self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
 290             }
 291             ast::Expr::WhileExpr(e) => {
 292                 let label = e.label().map(|label| self.collect_label(label));
 293                 let body = self.collect_block_opt(e.loop_body());
 294
 295                 let condition = match e.condition() {
 296                     None => self.missing_expr(),
 297                     Some(condition) => match condition.pat() {
 298                         None => self.collect_expr_opt(condition.expr()),
 299                         // if let -- desugar to match
 300                         Some(pat) => {
 301                             cov_mark::hit!(infer_resolve_while_let);
 302                             let pat = self.collect_pat(pat);
 303                             let match_expr = self.collect_expr_opt(condition.expr());
 304                             let placeholder_pat = self.missing_pat();
 305                             let break_ =
 306                                 self.alloc_expr_desugared(Expr::Break { expr: None, label: None });
 307                             let arms = vec![
 308                                 MatchArm { pat, expr: body, guard: None },
 309                                 MatchArm { pat: placeholder_pat, expr: break_, guard: None },
 310                             ];
 311                             let match_expr =
 312                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
 313                             return Some(
 314                                 self.alloc_expr(Expr::Loop { body: match_expr, label }, syntax_ptr),
 315                             );
 316                         }
 317                     },
 318                 };
 319
 320                 self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
 321             }
 322             ast::Expr::ForExpr(e) => {
 323                 let label = e.label().map(|label| self.collect_label(label));
 324                 let iterable = self.collect_expr_opt(e.iterable());
 325                 let pat = self.collect_pat_opt(e.pat());
 326                 let body = self.collect_block_opt(e.loop_body());
 327                 self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
 328             }
 329             ast::Expr::CallExpr(e) => {
 330                 let callee = self.collect_expr_opt(e.expr());
 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                     Vec::new()
 335                 };
 336                 self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
 337             }
 338             ast::Expr::MethodCallExpr(e) => {
 339                 let receiver = self.collect_expr_opt(e.receiver());
 340                 let args = if let Some(arg_list) = e.arg_list() {
 341                     arg_list.args().filter_map(|e| self.maybe_collect_expr(e)).collect()
 342                 } else {
 343                     Vec::new()
 344                 };
 345                 let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 346                 let generic_args = e
 347                     .generic_arg_list()
 348                     .and_then(|it| GenericArgs::from_ast(&self.ctx(), it))
 349                     .map(Box::new);
 350                 self.alloc_expr(
 351                     Expr::MethodCall { receiver, method_name, args, generic_args },
 352                     syntax_ptr,
 353                 )
 354             }
 355             ast::Expr::MatchExpr(e) => {
 356                 let expr = self.collect_expr_opt(e.expr());
 357                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
 358                     match_arm_list
 359                         .arms()
 360                         .filter_map(|arm| {
 361                             self.check_cfg(&arm).map(|()| MatchArm {
 362                                 pat: self.collect_pat_opt(arm.pat()),
 363                                 expr: self.collect_expr_opt(arm.expr()),
 364                                 guard: arm
 365                                     .guard()
 366                                     .and_then(|guard| guard.expr())
 367                                     .map(|e| self.collect_expr(e)),
 368                             })
 369                         })
 370                         .collect()
 371                 } else {
 372                     Vec::new()
 373                 };
 374                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
 375             }
 376             ast::Expr::PathExpr(e) => {
 377                 let path = e
 378                     .path()
 379                     .and_then(|path| self.expander.parse_path(path))
 380                     .map(Expr::Path)
 381                     .unwrap_or(Expr::Missing);
 382                 self.alloc_expr(path, syntax_ptr)
 383             }
 384             ast::Expr::ContinueExpr(e) => self.alloc_expr(
 385                 Expr::Continue { label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 386                 syntax_ptr,
 387             ),
 388             ast::Expr::BreakExpr(e) => {
 389                 let expr = e.expr().map(|e| self.collect_expr(e));
 390                 self.alloc_expr(
 391                     Expr::Break { expr, label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 392                     syntax_ptr,
 393                 )
 394             }
 395             ast::Expr::ParenExpr(e) => {
 396                 let inner = self.collect_expr_opt(e.expr());
 397                 // make the paren expr point to the inner expression as well
 398                 let src = self.expander.to_source(syntax_ptr);
 399                 self.source_map.expr_map.insert(src, inner);
 400                 inner
 401             }
 402             ast::Expr::ReturnExpr(e) => {
 403                 let expr = e.expr().map(|e| self.collect_expr(e));
 404                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
 405             }
 406             ast::Expr::YieldExpr(e) => {
 407                 let expr = e.expr().map(|e| self.collect_expr(e));
 408                 self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
 409             }
 410             ast::Expr::RecordExpr(e) => {
 411                 let path = e.path().and_then(|path| self.expander.parse_path(path)).map(Box::new);
 412                 let record_lit = if let Some(nfl) = e.record_expr_field_list() {
 413                     let fields = nfl
 414                         .fields()
 415                         .filter_map(|field| {
 416                             self.check_cfg(&field)?;
 417
 418                             let name = field.field_name()?.as_name();
 419
 420                             let expr = match field.expr() {
 421                                 Some(e) => self.collect_expr(e),
 422                                 None => self.missing_expr(),
 423                             };
 424                             let src = self.expander.to_source(AstPtr::new(&field));
 425                             self.source_map.field_map.insert(src.clone(), expr);
 426                             self.source_map.field_map_back.insert(expr, src);
 427                             Some(RecordLitField { name, expr })
 428                         })
 429                         .collect();
 430                     let spread = nfl.spread().map(|s| self.collect_expr(s));
 431                     Expr::RecordLit { path, fields, spread }
 432                 } else {
 433                     Expr::RecordLit { path, fields: Vec::new(), spread: None }
 434                 };
 435
 436                 self.alloc_expr(record_lit, syntax_ptr)
 437             }
 438             ast::Expr::FieldExpr(e) => {
 439                 let expr = self.collect_expr_opt(e.expr());
 440                 let name = match e.field_access() {
 441                     Some(kind) => kind.as_name(),
 442                     _ => Name::missing(),
 443                 };
 444                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
 445             }
 446             ast::Expr::AwaitExpr(e) => {
 447                 let expr = self.collect_expr_opt(e.expr());
 448                 self.alloc_expr(Expr::Await { expr }, syntax_ptr)
 449             }
 450             ast::Expr::TryExpr(e) => {
 451                 let expr = self.collect_expr_opt(e.expr());
 452                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
 453             }
 454             ast::Expr::CastExpr(e) => {
 455                 let expr = self.collect_expr_opt(e.expr());
 456                 let type_ref = Interned::new(TypeRef::from_ast_opt(&self.ctx(), e.ty()));
 457                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
 458             }
 459             ast::Expr::RefExpr(e) => {
 460                 let expr = self.collect_expr_opt(e.expr());
 461                 let raw_tok = e.raw_token().is_some();
 462                 let mutability = if raw_tok {
 463                     if e.mut_token().is_some() {
 464                         Mutability::Mut
 465                     } else if e.const_token().is_some() {
 466                         Mutability::Shared
 467                     } else {
 468                         unreachable!("parser only remaps to raw_token() if matching mutability token follows")
 469                     }
 470                 } else {
 471                     Mutability::from_mutable(e.mut_token().is_some())
 472                 };
 473                 let rawness = Rawness::from_raw(raw_tok);
 474                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
 475             }
 476             ast::Expr::PrefixExpr(e) => {
 477                 let expr = self.collect_expr_opt(e.expr());
 478                 if let Some(op) = e.op_kind() {
 479                     self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr)
 480                 } else {
 481                     self.alloc_expr(Expr::Missing, syntax_ptr)
 482                 }
 483             }
 484             ast::Expr::ClosureExpr(e) => {
 485                 let mut args = Vec::new();
 486                 let mut arg_types = Vec::new();
 487                 if let Some(pl) = e.param_list() {
 488                     for param in pl.params() {
 489                         let pat = self.collect_pat_opt(param.pat());
 490                         let type_ref =
 491                             param.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 492                         args.push(pat);
 493                         arg_types.push(type_ref);
 494                     }
 495                 }
 496                 let ret_type = e
 497                     .ret_type()
 498                     .and_then(|r| r.ty())
 499                     .map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 500                 let body = self.collect_expr_opt(e.body());
 501                 self.alloc_expr(Expr::Lambda { args, arg_types, ret_type, body }, syntax_ptr)
 502             }
 503             ast::Expr::BinExpr(e) => {
 504                 let lhs = self.collect_expr_opt(e.lhs());
 505                 let rhs = self.collect_expr_opt(e.rhs());
 506                 let op = e.op_kind().map(BinaryOp::from);
 507                 self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
 508             }
 509             ast::Expr::TupleExpr(e) => {
 510                 let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect();
 511                 self.alloc_expr(Expr::Tuple { exprs }, syntax_ptr)
 512             }
 513             ast::Expr::BoxExpr(e) => {
 514                 let expr = self.collect_expr_opt(e.expr());
 515                 self.alloc_expr(Expr::Box { expr }, syntax_ptr)
 516             }
 517
 518             ast::Expr::ArrayExpr(e) => {
 519                 let kind = e.kind();
 520
 521                 match kind {
 522                     ArrayExprKind::ElementList(e) => {
 523                         let exprs = e.map(|expr| self.collect_expr(expr)).collect();
 524                         self.alloc_expr(Expr::Array(Array::ElementList(exprs)), syntax_ptr)
 525                     }
 526                     ArrayExprKind::Repeat { initializer, repeat } => {
 527                         let initializer = self.collect_expr_opt(initializer);
 528                         let repeat = self.collect_expr_opt(repeat);
 529                         self.alloc_expr(
 530                             Expr::Array(Array::Repeat { initializer, repeat }),
 531                             syntax_ptr,
 532                         )
 533                     }
 534                 }
 535             }
 536
 537             ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
 538             ast::Expr::IndexExpr(e) => {
 539                 let base = self.collect_expr_opt(e.base());
 540                 let index = self.collect_expr_opt(e.index());
 541                 self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
 542             }
 543             ast::Expr::RangeExpr(e) => {
 544                 let lhs = e.start().map(|lhs| self.collect_expr(lhs));
 545                 let rhs = e.end().map(|rhs| self.collect_expr(rhs));
 546                 match e.op_kind() {
 547                     Some(range_type) => {
 548                         self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
 549                     }
 550                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 551                 }
 552             }
 553             ast::Expr::MacroCall(e) => {
 554                 let macro_ptr = AstPtr::new(&e);
 555                 let mut ids = vec![];
 556                 self.collect_macro_call(e, macro_ptr, true, |this, expansion| {
 557                     ids.push(match expansion {
 558                         Some(it) => this.collect_expr(it),
 559                         None => this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
 560                     })
 561                 });
 562                 ids[0]
 563             }
 564             ast::Expr::MacroStmts(e) => {
 565                 e.statements().for_each(|s| self.collect_stmt(s));
 566                 let tail = e
 567                     .expr()
 568                     .map(|e| self.collect_expr(e))
 569                     .unwrap_or_else(|| self.alloc_expr(Expr::Missing, syntax_ptr.clone()));
 570
 571                 self.alloc_expr(Expr::MacroStmts { tail }, syntax_ptr)
 572             }
 573         })
 574     }
 575
 576     fn collect_macro_call<F: FnMut(&mut Self, Option<T>), T: ast::AstNode>(
 577         &mut self,
 578         e: ast::MacroCall,
 579         syntax_ptr: AstPtr<ast::MacroCall>,
 580         is_error_recoverable: bool,
 581         mut collector: F,
 582     ) {
 583         // File containing the macro call. Expansion errors will be attached here.
 584         let outer_file = self.expander.current_file_id;
 585
 586         let macro_call = self.expander.to_source(AstPtr::new(&e));
 587         let res = self.expander.enter_expand(self.db, e);
 588
 589         let res = match res {
 590             Ok(res) => res,
 591             Err(UnresolvedMacro { path }) => {
 592                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedMacroCall(
 593                     UnresolvedMacroCall {
 594                         file: outer_file,
 595                         node: syntax_ptr.cast().unwrap(),
 596                         path,
 597                     },
 598                 ));
 599                 collector(self, None);
 600                 return;
 601             }
 602         };
 603
 604         match &res.err {
 605             Some(ExpandError::UnresolvedProcMacro) => {
 606                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro(
 607                     UnresolvedProcMacro {
 608                         file: outer_file,
 609                         node: syntax_ptr.into(),
 610                         precise_location: None,
 611                         macro_name: None,
 612                     },
 613                 ));
 614             }
 615             Some(err) => {
 616                 self.source_map.diagnostics.push(BodyDiagnostic::MacroError(MacroError {
 617                     file: outer_file,
 618                     node: syntax_ptr.into(),
 619                     message: err.to_string(),
 620                 }));
 621             }
 622             None => {}
 623         }
 624
 625         match res.value {
 626             Some((mark, expansion)) => {
 627                 // FIXME: Statements are too complicated to recover from error for now.
 628                 // It is because we don't have any hygiene for local variable expansion right now.
 629                 if !is_error_recoverable && res.err.is_some() {
 630                     self.expander.exit(self.db, mark);
 631                     collector(self, None);
 632                 } else {
 633                     self.source_map.expansions.insert(macro_call, self.expander.current_file_id);
 634
 635                     let id = collector(self, Some(expansion));
 636                     self.expander.exit(self.db, mark);
 637                     id
 638                 }
 639             }
 640             None => collector(self, None),
 641         }
 642     }
 643
 644     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 645         if let Some(expr) = expr {
 646             self.collect_expr(expr)
 647         } else {
 648             self.missing_expr()
 649         }
 650     }
 651
 652     fn collect_stmt(&mut self, s: ast::Stmt) {
 653         match s {
 654             ast::Stmt::LetStmt(stmt) => {
 655                 if self.check_cfg(&stmt).is_none() {
 656                     return;
 657                 }
 658                 let pat = self.collect_pat_opt(stmt.pat());
 659                 let type_ref =
 660                     stmt.ty().map(|it| Interned::new(TypeRef::from_ast(&self.ctx(), it)));
 661                 let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 662                 self.statements_in_scope.push(Statement::Let { pat, type_ref, initializer });
 663             }
 664             ast::Stmt::ExprStmt(stmt) => {
 665                 if self.check_cfg(&stmt).is_none() {
 666                     return;
 667                 }
 668
 669                 // Note that macro could be expended to multiple statements
 670                 if let Some(ast::Expr::MacroCall(m)) = stmt.expr() {
 671                     let macro_ptr = AstPtr::new(&m);
 672                     let syntax_ptr = AstPtr::new(&stmt.expr().unwrap());
 673
 674                     self.collect_macro_call(
 675                         m,
 676                         macro_ptr,
 677                         false,
 678                         |this, expansion| match expansion {
 679                             Some(expansion) => {
 680                                 let statements: ast::MacroStmts = expansion;
 681
 682                                 statements.statements().for_each(|stmt| this.collect_stmt(stmt));
 683                                 if let Some(expr) = statements.expr() {
 684                                     let expr = this.collect_expr(expr);
 685                                     this.statements_in_scope.push(Statement::Expr(expr));
 686                                 }
 687                             }
 688                             None => {
 689                                 let expr = this.alloc_expr(Expr::Missing, syntax_ptr.clone());
 690                                 this.statements_in_scope.push(Statement::Expr(expr));
 691                             }
 692                         },
 693                     );
 694                 } else {
 695                     let expr = self.collect_expr_opt(stmt.expr());
 696                     self.statements_in_scope.push(Statement::Expr(expr));
 697                 }
 698             }
 699             ast::Stmt::Item(item) => {
 700                 if self.check_cfg(&item).is_none() {
 701                     return;
 702                 }
 703             }
 704         }
 705     }
 706
 707     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 708         let ast_id = self.expander.ast_id(&block);
 709         let block_loc =
 710             BlockLoc { ast_id, module: self.expander.def_map.module_id(self.expander.module) };
 711         let block_id = self.db.intern_block(block_loc);
 712
 713         let (module, def_map) = match self.db.block_def_map(block_id) {
 714             Some(def_map) => {
 715                 self.body.block_scopes.push(block_id);
 716                 (def_map.root(), def_map)
 717             }
 718             None => (self.expander.module, self.expander.def_map.clone()),
 719         };
 720         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 721         let prev_local_module = mem::replace(&mut self.expander.module, module);
 722         let prev_statements = std::mem::take(&mut self.statements_in_scope);
 723
 724         block.statements().for_each(|s| self.collect_stmt(s));
 725
 726         let tail = block.tail_expr().map(|e| self.collect_expr(e));
 727         let statements = std::mem::replace(&mut self.statements_in_scope, prev_statements);
 728         let syntax_node_ptr = AstPtr::new(&block.into());
 729         let expr_id = self.alloc_expr(
 730             Expr::Block { id: block_id, statements, tail, label: None },
 731             syntax_node_ptr,
 732         );
 733
 734         self.expander.def_map = prev_def_map;
 735         self.expander.module = prev_local_module;
 736         expr_id
 737     }
 738
 739     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 740         if let Some(block) = expr {
 741             self.collect_block(block)
 742         } else {
 743             self.missing_expr()
 744         }
 745     }
 746
 747     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 748         let label = Label {
 749             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 750         };
 751         self.alloc_label(label, AstPtr::new(&ast_label))
 752     }
 753
 754     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 755         let pattern = match &pat {
 756             ast::Pat::IdentPat(bp) => {
 757                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 758                 let annotation =
 759                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 760                 let subpat = bp.pat().map(|subpat| self.collect_pat(subpat));
 761                 if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 762                     // This could also be a single-segment path pattern. To
 763                     // decide that, we need to try resolving the name.
 764                     let (resolved, _) = self.expander.def_map.resolve_path(
 765                         self.db,
 766                         self.expander.module,
 767                         &name.clone().into(),
 768                         BuiltinShadowMode::Other,
 769                     );
 770                     match resolved.take_values() {
 771                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 772                         Some(ModuleDefId::EnumVariantId(_)) => {
 773                             // this is only really valid for unit variants, but
 774                             // shadowing other enum variants with a pattern is
 775                             // an error anyway
 776                             Pat::Path(name.into())
 777                         }
 778                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 779                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 780                         {
 781                             // Funnily enough, record structs *can* be shadowed
 782                             // by pattern bindings (but unit or tuple structs
 783                             // can't).
 784                             Pat::Path(name.into())
 785                         }
 786                         // shadowing statics is an error as well, so we just ignore that case here
 787                         _ => Pat::Bind { name, mode: annotation, subpat },
 788                     }
 789                 } else {
 790                     Pat::Bind { name, mode: annotation, subpat }
 791                 }
 792             }
 793             ast::Pat::TupleStructPat(p) => {
 794                 let path = p.path().and_then(|path| self.expander.parse_path(path)).map(Box::new);
 795                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 796                 Pat::TupleStruct { path, args, ellipsis }
 797             }
 798             ast::Pat::RefPat(p) => {
 799                 let pat = self.collect_pat_opt(p.pat());
 800                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 801                 Pat::Ref { pat, mutability }
 802             }
 803             ast::Pat::PathPat(p) => {
 804                 let path = p.path().and_then(|path| self.expander.parse_path(path)).map(Box::new);
 805                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 806             }
 807             ast::Pat::OrPat(p) => {
 808                 let pats = p.pats().map(|p| self.collect_pat(p)).collect();
 809                 Pat::Or(pats)
 810             }
 811             ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat()),
 812             ast::Pat::TuplePat(p) => {
 813                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 814                 Pat::Tuple { args, ellipsis }
 815             }
 816             ast::Pat::WildcardPat(_) => Pat::Wild,
 817             ast::Pat::RecordPat(p) => {
 818                 let path = p.path().and_then(|path| self.expander.parse_path(path)).map(Box::new);
 819                 let args: Vec<_> = p
 820                     .record_pat_field_list()
 821                     .expect("every struct should have a field list")
 822                     .fields()
 823                     .filter_map(|f| {
 824                         let ast_pat = f.pat()?;
 825                         let pat = self.collect_pat(ast_pat);
 826                         let name = f.field_name()?.as_name();
 827                         Some(RecordFieldPat { name, pat })
 828                     })
 829                     .collect();
 830
 831                 let ellipsis = p
 832                     .record_pat_field_list()
 833                     .expect("every struct should have a field list")
 834                     .dotdot_token()
 835                     .is_some();
 836
 837                 Pat::Record { path, args, ellipsis }
 838             }
 839             ast::Pat::SlicePat(p) => {
 840                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 841
 842                 // FIXME properly handle `RestPat`
 843                 Pat::Slice {
 844                     prefix: prefix.into_iter().map(|p| self.collect_pat(p)).collect(),
 845                     slice: slice.map(|p| self.collect_pat(p)),
 846                     suffix: suffix.into_iter().map(|p| self.collect_pat(p)).collect(),
 847                 }
 848             }
 849             ast::Pat::LiteralPat(lit) => {
 850                 if let Some(ast_lit) = lit.literal() {
 851                     let expr = Expr::Literal(ast_lit.kind().into());
 852                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 853                     let expr_id = self.alloc_expr(expr, expr_ptr);
 854                     Pat::Lit(expr_id)
 855                 } else {
 856                     Pat::Missing
 857                 }
 858             }
 859             ast::Pat::RestPat(_) => {
 860                 // `RestPat` requires special handling and should not be mapped
 861                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 862                 // when `RestPat` is mapped to `Pat`, which can easily happen
 863                 // when the source code being analyzed has a malformed pattern
 864                 // which includes `..` in a place where it isn't valid.
 865
 866                 Pat::Missing
 867             }
 868             ast::Pat::BoxPat(boxpat) => {
 869                 let inner = self.collect_pat_opt(boxpat.pat());
 870                 Pat::Box { inner }
 871             }
 872             ast::Pat::ConstBlockPat(const_block_pat) => {
 873                 if let Some(expr) = const_block_pat.block_expr() {
 874                     let expr_id = self.collect_block(expr);
 875                     Pat::ConstBlock(expr_id)
 876                 } else {
 877                     Pat::Missing
 878                 }
 879             }
 880             ast::Pat::MacroPat(mac) => match mac.macro_call() {
 881                 Some(call) => {
 882                     let macro_ptr = AstPtr::new(&call);
 883                     let mut pat = None;
 884                     self.collect_macro_call(call, macro_ptr, true, |this, expanded_pat| {
 885                         pat = Some(this.collect_pat_opt(expanded_pat));
 886                     });
 887
 888                     match pat {
 889                         Some(pat) => return pat,
 890                         None => Pat::Missing,
 891                     }
 892                 }
 893                 None => Pat::Missing,
 894             },
 895             // FIXME: implement
 896             ast::Pat::RangePat(_) => Pat::Missing,
 897         };
 898         let ptr = AstPtr::new(&pat);
 899         self.alloc_pat(pattern, Either::Left(ptr))
 900     }
 901
 902     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 903         if let Some(pat) = pat {
 904             self.collect_pat(pat)
 905         } else {
 906             self.missing_pat()
 907         }
 908     }
 909
 910     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Vec<PatId>, Option<usize>) {
 911         // Find the location of the `..`, if there is one. Note that we do not
 912         // consider the possibility of there being multiple `..` here.
 913         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 914         // We want to skip the `..` pattern here, since we account for it above.
 915         let args = args
 916             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 917             .map(|p| self.collect_pat(p))
 918             .collect();
 919
 920         (args, ellipsis)
 921     }
 922
 923     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 924     /// not.
 925     fn check_cfg(&mut self, owner: &dyn ast::AttrsOwner) -> Option<()> {
 926         match self.expander.parse_attrs(self.db, owner).cfg() {
 927             Some(cfg) => {
 928                 if self.expander.cfg_options().check(&cfg) != Some(false) {
 929                     return Some(());
 930                 }
 931
 932                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode(InactiveCode {
 933                     file: self.expander.current_file_id,
 934                     node: SyntaxNodePtr::new(owner.syntax()),
 935                     cfg,
 936                     opts: self.expander.cfg_options().clone(),
 937                 }));
 938
 939                 None
 940             }
 941             None => Some(()),
 942         }
 943     }
 944 }
 945
 946 impl From<ast::BinOp> for BinaryOp {
 947     fn from(ast_op: ast::BinOp) -> Self {
 948         match ast_op {
 949             ast::BinOp::BooleanOr => BinaryOp::LogicOp(LogicOp::Or),
 950             ast::BinOp::BooleanAnd => BinaryOp::LogicOp(LogicOp::And),
 951             ast::BinOp::EqualityTest => BinaryOp::CmpOp(CmpOp::Eq { negated: false }),
 952             ast::BinOp::NegatedEqualityTest => BinaryOp::CmpOp(CmpOp::Eq { negated: true }),
 953             ast::BinOp::LesserEqualTest => {
 954                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Less, strict: false })
 955             }
 956             ast::BinOp::GreaterEqualTest => {
 957                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Greater, strict: false })
 958             }
 959             ast::BinOp::LesserTest => {
 960                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Less, strict: true })
 961             }
 962             ast::BinOp::GreaterTest => {
 963                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Greater, strict: true })
 964             }
 965             ast::BinOp::Addition => BinaryOp::ArithOp(ArithOp::Add),
 966             ast::BinOp::Multiplication => BinaryOp::ArithOp(ArithOp::Mul),
 967             ast::BinOp::Subtraction => BinaryOp::ArithOp(ArithOp::Sub),
 968             ast::BinOp::Division => BinaryOp::ArithOp(ArithOp::Div),
 969             ast::BinOp::Remainder => BinaryOp::ArithOp(ArithOp::Rem),
 970             ast::BinOp::LeftShift => BinaryOp::ArithOp(ArithOp::Shl),
 971             ast::BinOp::RightShift => BinaryOp::ArithOp(ArithOp::Shr),
 972             ast::BinOp::BitwiseXor => BinaryOp::ArithOp(ArithOp::BitXor),
 973             ast::BinOp::BitwiseOr => BinaryOp::ArithOp(ArithOp::BitOr),
 974             ast::BinOp::BitwiseAnd => BinaryOp::ArithOp(ArithOp::BitAnd),
 975             ast::BinOp::Assignment => BinaryOp::Assignment { op: None },
 976             ast::BinOp::AddAssign => BinaryOp::Assignment { op: Some(ArithOp::Add) },
 977             ast::BinOp::DivAssign => BinaryOp::Assignment { op: Some(ArithOp::Div) },
 978             ast::BinOp::MulAssign => BinaryOp::Assignment { op: Some(ArithOp::Mul) },
 979             ast::BinOp::RemAssign => BinaryOp::Assignment { op: Some(ArithOp::Rem) },
 980             ast::BinOp::ShlAssign => BinaryOp::Assignment { op: Some(ArithOp::Shl) },
 981             ast::BinOp::ShrAssign => BinaryOp::Assignment { op: Some(ArithOp::Shr) },
 982             ast::BinOp::SubAssign => BinaryOp::Assignment { op: Some(ArithOp::Sub) },
 983             ast::BinOp::BitOrAssign => BinaryOp::Assignment { op: Some(ArithOp::BitOr) },
 984             ast::BinOp::BitAndAssign => BinaryOp::Assignment { op: Some(ArithOp::BitAnd) },
 985             ast::BinOp::BitXorAssign => BinaryOp::Assignment { op: Some(ArithOp::BitXor) },
 986         }
 987     }
 988 }
 989
 990 impl From<ast::LiteralKind> for Literal {
 991     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
 992         match ast_lit_kind {
 993             LiteralKind::IntNumber(lit) => {
 994                 if let builtin @ Some(_) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
 995                     return Literal::Float(Default::default(), builtin);
 996                 } else if let builtin @ Some(_) =
 997                     lit.suffix().and_then(|it| BuiltinInt::from_suffix(&it))
 998                 {
 999                     Literal::Int(Default::default(), builtin)
1000                 } else {
1001                     let builtin = lit.suffix().and_then(|it| BuiltinUint::from_suffix(&it));
1002                     Literal::Uint(Default::default(), builtin)
1003                 }
1004             }
1005             LiteralKind::FloatNumber(lit) => {
1006                 let ty = lit.suffix().and_then(|it| BuiltinFloat::from_suffix(&it));
1007                 Literal::Float(Default::default(), ty)
1008             }
1009             LiteralKind::ByteString(_) => Literal::ByteString(Default::default()),
1010             LiteralKind::String(_) => Literal::String(Default::default()),
1011             LiteralKind::Byte => Literal::Uint(Default::default(), Some(BuiltinUint::U8)),
1012             LiteralKind::Bool(val) => Literal::Bool(val),
1013             LiteralKind::Char => Literal::Char(Default::default()),
1014         }
1015     }
1016 }