crates/hir_def/src/body/lower.rs

   1 //! Transforms `ast::Expr` into an equivalent `hir_def::expr::Expr`
   2 //! representation.
   3
   4 use std::{any::type_name, mem, sync::Arc};
   5
   6 use either::Either;
   7 use hir_expand::{
   8     hygiene::Hygiene,
   9     name::{name, AsName, Name},
  10     ExpandError, HirFileId, MacroDefId, MacroDefKind,
  11 };
  12 use la_arena::Arena;
  13 use profile::Count;
  14 use rustc_hash::FxHashMap;
  15 use syntax::{
  16     ast::{
  17         self, ArgListOwner, ArrayExprKind, AstChildren, LiteralKind, LoopBodyOwner, NameOwner,
  18         SlicePatComponents,
  19     },
  20     AstNode, AstPtr, SyntaxNodePtr,
  21 };
  22 use test_utils::mark;
  23
  24 use crate::{
  25     adt::StructKind,
  26     body::{Body, BodySourceMap, Expander, LabelSource, PatPtr, SyntheticSyntax},
  27     builtin_type::{BuiltinFloat, BuiltinInt},
  28     db::DefDatabase,
  29     diagnostics::{InactiveCode, MacroError, UnresolvedProcMacro},
  30     expr::{
  31         dummy_expr_id, ArithOp, Array, BinaryOp, BindingAnnotation, CmpOp, Expr, ExprId, Label,
  32         LabelId, Literal, LogicOp, MatchArm, Ordering, Pat, PatId, RecordFieldPat, RecordLitField,
  33         Statement,
  34     },
  35     item_scope::BuiltinShadowMode,
  36     item_tree::{ItemTree, ItemTreeId, ItemTreeNode},
  37     path::{GenericArgs, Path},
  38     type_ref::{Mutability, Rawness, TypeRef},
  39     AdtId, BlockLoc, ConstLoc, ContainerId, DefWithBodyId, EnumLoc, FunctionLoc, Intern,
  40     ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
  41 };
  42
  43 use super::{diagnostics::BodyDiagnostic, ExprSource, PatSource};
  44
  45 pub(crate) struct LowerCtx {
  46     hygiene: Hygiene,
  47 }
  48
  49 impl LowerCtx {
  50     pub(crate) fn new(db: &dyn DefDatabase, file_id: HirFileId) -> Self {
  51         LowerCtx { hygiene: Hygiene::new(db.upcast(), file_id) }
  52     }
  53     pub(crate) fn with_hygiene(hygiene: &Hygiene) -> Self {
  54         LowerCtx { hygiene: hygiene.clone() }
  55     }
  56
  57     pub(crate) fn lower_path(&self, ast: ast::Path) -> Option<Path> {
  58         Path::from_src(ast, &self.hygiene)
  59     }
  60 }
  61
  62 pub(super) fn lower(
  63     db: &dyn DefDatabase,
  64     def: DefWithBodyId,
  65     expander: Expander,
  66     params: Option<ast::ParamList>,
  67     body: Option<ast::Expr>,
  68 ) -> (Body, BodySourceMap) {
  69     let item_tree = db.item_tree(expander.current_file_id);
  70     ExprCollector {
  71         db,
  72         def,
  73         source_map: BodySourceMap::default(),
  74         body: Body {
  75             exprs: Arena::default(),
  76             pats: Arena::default(),
  77             labels: Arena::default(),
  78             params: Vec::new(),
  79             body_expr: dummy_expr_id(),
  80             item_scope: Default::default(),
  81             _c: Count::new(),
  82         },
  83         item_trees: {
  84             let mut map = FxHashMap::default();
  85             map.insert(expander.current_file_id, item_tree);
  86             map
  87         },
  88         expander,
  89     }
  90     .collect(params, body)
  91 }
  92
  93 struct ExprCollector<'a> {
  94     db: &'a dyn DefDatabase,
  95     def: DefWithBodyId,
  96     expander: Expander,
  97     body: Body,
  98     source_map: BodySourceMap,
  99
 100     item_trees: FxHashMap<HirFileId, Arc<ItemTree>>,
 101 }
 102
 103 impl ExprCollector<'_> {
 104     fn collect(
 105         mut self,
 106         param_list: Option<ast::ParamList>,
 107         body: Option<ast::Expr>,
 108     ) -> (Body, BodySourceMap) {
 109         if let Some(param_list) = param_list {
 110             if let Some(self_param) = param_list.self_param() {
 111                 let ptr = AstPtr::new(&self_param);
 112                 let param_pat = self.alloc_pat(
 113                     Pat::Bind {
 114                         name: name![self],
 115                         mode: BindingAnnotation::new(
 116                             self_param.mut_token().is_some() && self_param.amp_token().is_none(),
 117                             false,
 118                         ),
 119                         subpat: None,
 120                     },
 121                     Either::Right(ptr),
 122                 );
 123                 self.body.params.push(param_pat);
 124             }
 125
 126             for param in param_list.params() {
 127                 let pat = match param.pat() {
 128                     None => continue,
 129                     Some(pat) => pat,
 130                 };
 131                 let param_pat = self.collect_pat(pat);
 132                 self.body.params.push(param_pat);
 133             }
 134         };
 135
 136         self.body.body_expr = self.collect_expr_opt(body);
 137         (self.body, self.source_map)
 138     }
 139
 140     fn ctx(&self) -> LowerCtx {
 141         LowerCtx::new(self.db, self.expander.current_file_id)
 142     }
 143
 144     fn alloc_expr(&mut self, expr: Expr, ptr: AstPtr<ast::Expr>) -> ExprId {
 145         let src = self.expander.to_source(ptr);
 146         let id = self.make_expr(expr, Ok(src.clone()));
 147         self.source_map.expr_map.insert(src, id);
 148         id
 149     }
 150     // desugared exprs don't have ptr, that's wrong and should be fixed
 151     // somehow.
 152     fn alloc_expr_desugared(&mut self, expr: Expr) -> ExprId {
 153         self.make_expr(expr, Err(SyntheticSyntax))
 154     }
 155     fn unit(&mut self) -> ExprId {
 156         self.alloc_expr_desugared(Expr::Tuple { exprs: Vec::new() })
 157     }
 158     fn missing_expr(&mut self) -> ExprId {
 159         self.alloc_expr_desugared(Expr::Missing)
 160     }
 161     fn make_expr(&mut self, expr: Expr, src: Result<ExprSource, SyntheticSyntax>) -> ExprId {
 162         let id = self.body.exprs.alloc(expr);
 163         self.source_map.expr_map_back.insert(id, src);
 164         id
 165     }
 166
 167     fn alloc_pat(&mut self, pat: Pat, ptr: PatPtr) -> PatId {
 168         let src = self.expander.to_source(ptr);
 169         let id = self.make_pat(pat, Ok(src.clone()));
 170         self.source_map.pat_map.insert(src, id);
 171         id
 172     }
 173     fn missing_pat(&mut self) -> PatId {
 174         self.make_pat(Pat::Missing, Err(SyntheticSyntax))
 175     }
 176     fn make_pat(&mut self, pat: Pat, src: Result<PatSource, SyntheticSyntax>) -> PatId {
 177         let id = self.body.pats.alloc(pat);
 178         self.source_map.pat_map_back.insert(id, src);
 179         id
 180     }
 181
 182     fn alloc_label(&mut self, label: Label, ptr: AstPtr<ast::Label>) -> LabelId {
 183         let src = self.expander.to_source(ptr);
 184         let id = self.make_label(label, src.clone());
 185         self.source_map.label_map.insert(src, id);
 186         id
 187     }
 188     fn make_label(&mut self, label: Label, src: LabelSource) -> LabelId {
 189         let id = self.body.labels.alloc(label);
 190         self.source_map.label_map_back.insert(id, src);
 191         id
 192     }
 193
 194     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
 195         let syntax_ptr = AstPtr::new(&expr);
 196         if self.check_cfg(&expr).is_none() {
 197             return self.missing_expr();
 198         }
 199
 200         match expr {
 201             ast::Expr::IfExpr(e) => {
 202                 let then_branch = self.collect_block_opt(e.then_branch());
 203
 204                 let else_branch = e.else_branch().map(|b| match b {
 205                     ast::ElseBranch::Block(it) => self.collect_block(it),
 206                     ast::ElseBranch::IfExpr(elif) => {
 207                         let expr: ast::Expr = ast::Expr::cast(elif.syntax().clone()).unwrap();
 208                         self.collect_expr(expr)
 209                     }
 210                 });
 211
 212                 let condition = match e.condition() {
 213                     None => self.missing_expr(),
 214                     Some(condition) => match condition.pat() {
 215                         None => self.collect_expr_opt(condition.expr()),
 216                         // if let -- desugar to match
 217                         Some(pat) => {
 218                             let pat = self.collect_pat(pat);
 219                             let match_expr = self.collect_expr_opt(condition.expr());
 220                             let placeholder_pat = self.missing_pat();
 221                             let arms = vec![
 222                                 MatchArm { pat, expr: then_branch, guard: None },
 223                                 MatchArm {
 224                                     pat: placeholder_pat,
 225                                     expr: else_branch.unwrap_or_else(|| self.unit()),
 226                                     guard: None,
 227                                 },
 228                             ];
 229                             return self
 230                                 .alloc_expr(Expr::Match { expr: match_expr, arms }, syntax_ptr);
 231                         }
 232                     },
 233                 };
 234
 235                 self.alloc_expr(Expr::If { condition, then_branch, else_branch }, syntax_ptr)
 236             }
 237             ast::Expr::EffectExpr(e) => match e.effect() {
 238                 ast::Effect::Try(_) => {
 239                     let body = self.collect_block_opt(e.block_expr());
 240                     self.alloc_expr(Expr::TryBlock { body }, syntax_ptr)
 241                 }
 242                 ast::Effect::Unsafe(_) => {
 243                     let body = self.collect_block_opt(e.block_expr());
 244                     self.alloc_expr(Expr::Unsafe { body }, syntax_ptr)
 245                 }
 246                 // FIXME: we need to record these effects somewhere...
 247                 ast::Effect::Label(label) => {
 248                     let label = self.collect_label(label);
 249                     match e.block_expr() {
 250                         Some(block) => {
 251                             let res = self.collect_block(block);
 252                             match &mut self.body.exprs[res] {
 253                                 Expr::Block { label: block_label, .. } => {
 254                                     *block_label = Some(label);
 255                                 }
 256                                 _ => unreachable!(),
 257                             }
 258                             res
 259                         }
 260                         None => self.missing_expr(),
 261                     }
 262                 }
 263                 // FIXME: we need to record these effects somewhere...
 264                 ast::Effect::Async(_) => {
 265                     let body = self.collect_block_opt(e.block_expr());
 266                     self.alloc_expr(Expr::Async { body }, syntax_ptr)
 267                 }
 268                 ast::Effect::Const(_) => {
 269                     let body = self.collect_block_opt(e.block_expr());
 270                     self.alloc_expr(Expr::Const { body }, syntax_ptr)
 271                 }
 272             },
 273             ast::Expr::BlockExpr(e) => self.collect_block(e),
 274             ast::Expr::LoopExpr(e) => {
 275                 let label = e.label().map(|label| self.collect_label(label));
 276                 let body = self.collect_block_opt(e.loop_body());
 277                 self.alloc_expr(Expr::Loop { body, label }, syntax_ptr)
 278             }
 279             ast::Expr::WhileExpr(e) => {
 280                 let label = e.label().map(|label| self.collect_label(label));
 281                 let body = self.collect_block_opt(e.loop_body());
 282
 283                 let condition = match e.condition() {
 284                     None => self.missing_expr(),
 285                     Some(condition) => match condition.pat() {
 286                         None => self.collect_expr_opt(condition.expr()),
 287                         // if let -- desugar to match
 288                         Some(pat) => {
 289                             mark::hit!(infer_resolve_while_let);
 290                             let pat = self.collect_pat(pat);
 291                             let match_expr = self.collect_expr_opt(condition.expr());
 292                             let placeholder_pat = self.missing_pat();
 293                             let break_ =
 294                                 self.alloc_expr_desugared(Expr::Break { expr: None, label: None });
 295                             let arms = vec![
 296                                 MatchArm { pat, expr: body, guard: None },
 297                                 MatchArm { pat: placeholder_pat, expr: break_, guard: None },
 298                             ];
 299                             let match_expr =
 300                                 self.alloc_expr_desugared(Expr::Match { expr: match_expr, arms });
 301                             return self
 302                                 .alloc_expr(Expr::Loop { body: match_expr, label }, syntax_ptr);
 303                         }
 304                     },
 305                 };
 306
 307                 self.alloc_expr(Expr::While { condition, body, label }, syntax_ptr)
 308             }
 309             ast::Expr::ForExpr(e) => {
 310                 let label = e.label().map(|label| self.collect_label(label));
 311                 let iterable = self.collect_expr_opt(e.iterable());
 312                 let pat = self.collect_pat_opt(e.pat());
 313                 let body = self.collect_block_opt(e.loop_body());
 314                 self.alloc_expr(Expr::For { iterable, pat, body, label }, syntax_ptr)
 315             }
 316             ast::Expr::CallExpr(e) => {
 317                 let callee = self.collect_expr_opt(e.expr());
 318                 let args = if let Some(arg_list) = e.arg_list() {
 319                     arg_list.args().map(|e| self.collect_expr(e)).collect()
 320                 } else {
 321                     Vec::new()
 322                 };
 323                 self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
 324             }
 325             ast::Expr::MethodCallExpr(e) => {
 326                 let receiver = self.collect_expr_opt(e.receiver());
 327                 let args = if let Some(arg_list) = e.arg_list() {
 328                     arg_list.args().map(|e| self.collect_expr(e)).collect()
 329                 } else {
 330                     Vec::new()
 331                 };
 332                 let method_name = e.name_ref().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 333                 let generic_args =
 334                     e.generic_arg_list().and_then(|it| GenericArgs::from_ast(&self.ctx(), it));
 335                 self.alloc_expr(
 336                     Expr::MethodCall { receiver, method_name, args, generic_args },
 337                     syntax_ptr,
 338                 )
 339             }
 340             ast::Expr::MatchExpr(e) => {
 341                 let expr = self.collect_expr_opt(e.expr());
 342                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
 343                     match_arm_list
 344                         .arms()
 345                         .filter_map(|arm| {
 346                             self.check_cfg(&arm).map(|()| MatchArm {
 347                                 pat: self.collect_pat_opt(arm.pat()),
 348                                 expr: self.collect_expr_opt(arm.expr()),
 349                                 guard: arm
 350                                     .guard()
 351                                     .and_then(|guard| guard.expr())
 352                                     .map(|e| self.collect_expr(e)),
 353                             })
 354                         })
 355                         .collect()
 356                 } else {
 357                     Vec::new()
 358                 };
 359                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
 360             }
 361             ast::Expr::PathExpr(e) => {
 362                 let path = e
 363                     .path()
 364                     .and_then(|path| self.expander.parse_path(path))
 365                     .map(Expr::Path)
 366                     .unwrap_or(Expr::Missing);
 367                 self.alloc_expr(path, syntax_ptr)
 368             }
 369             ast::Expr::ContinueExpr(e) => self.alloc_expr(
 370                 Expr::Continue { label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 371                 syntax_ptr,
 372             ),
 373             ast::Expr::BreakExpr(e) => {
 374                 let expr = e.expr().map(|e| self.collect_expr(e));
 375                 self.alloc_expr(
 376                     Expr::Break { expr, label: e.lifetime().map(|l| Name::new_lifetime(&l)) },
 377                     syntax_ptr,
 378                 )
 379             }
 380             ast::Expr::ParenExpr(e) => {
 381                 let inner = self.collect_expr_opt(e.expr());
 382                 // make the paren expr point to the inner expression as well
 383                 let src = self.expander.to_source(syntax_ptr);
 384                 self.source_map.expr_map.insert(src, inner);
 385                 inner
 386             }
 387             ast::Expr::ReturnExpr(e) => {
 388                 let expr = e.expr().map(|e| self.collect_expr(e));
 389                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
 390             }
 391             ast::Expr::YieldExpr(e) => {
 392                 let expr = e.expr().map(|e| self.collect_expr(e));
 393                 self.alloc_expr(Expr::Yield { expr }, syntax_ptr)
 394             }
 395             ast::Expr::RecordExpr(e) => {
 396                 let path = e.path().and_then(|path| self.expander.parse_path(path));
 397                 let mut field_ptrs = Vec::new();
 398                 let record_lit = if let Some(nfl) = e.record_expr_field_list() {
 399                     let fields = nfl
 400                         .fields()
 401                         .inspect(|field| field_ptrs.push(AstPtr::new(field)))
 402                         .filter_map(|field| {
 403                             self.check_cfg(&field)?;
 404
 405                             let name = field.field_name()?.as_name();
 406
 407                             Some(RecordLitField {
 408                                 name,
 409                                 expr: match field.expr() {
 410                                     Some(e) => self.collect_expr(e),
 411                                     None => self.missing_expr(),
 412                                 },
 413                             })
 414                         })
 415                         .collect();
 416                     let spread = nfl.spread().map(|s| self.collect_expr(s));
 417                     Expr::RecordLit { path, fields, spread }
 418                 } else {
 419                     Expr::RecordLit { path, fields: Vec::new(), spread: None }
 420                 };
 421
 422                 let res = self.alloc_expr(record_lit, syntax_ptr);
 423                 for (i, ptr) in field_ptrs.into_iter().enumerate() {
 424                     let src = self.expander.to_source(ptr);
 425                     self.source_map.field_map.insert((res, i), src);
 426                 }
 427                 res
 428             }
 429             ast::Expr::FieldExpr(e) => {
 430                 let expr = self.collect_expr_opt(e.expr());
 431                 let name = match e.field_access() {
 432                     Some(kind) => kind.as_name(),
 433                     _ => Name::missing(),
 434                 };
 435                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
 436             }
 437             ast::Expr::AwaitExpr(e) => {
 438                 let expr = self.collect_expr_opt(e.expr());
 439                 self.alloc_expr(Expr::Await { expr }, syntax_ptr)
 440             }
 441             ast::Expr::TryExpr(e) => {
 442                 let expr = self.collect_expr_opt(e.expr());
 443                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
 444             }
 445             ast::Expr::CastExpr(e) => {
 446                 let expr = self.collect_expr_opt(e.expr());
 447                 let type_ref = TypeRef::from_ast_opt(&self.ctx(), e.ty());
 448                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
 449             }
 450             ast::Expr::RefExpr(e) => {
 451                 let expr = self.collect_expr_opt(e.expr());
 452                 let raw_tok = e.raw_token().is_some();
 453                 let mutability = if raw_tok {
 454                     if e.mut_token().is_some() {
 455                         Mutability::Mut
 456                     } else if e.const_token().is_some() {
 457                         Mutability::Shared
 458                     } else {
 459                         unreachable!("parser only remaps to raw_token() if matching mutability token follows")
 460                     }
 461                 } else {
 462                     Mutability::from_mutable(e.mut_token().is_some())
 463                 };
 464                 let rawness = Rawness::from_raw(raw_tok);
 465                 self.alloc_expr(Expr::Ref { expr, rawness, mutability }, syntax_ptr)
 466             }
 467             ast::Expr::PrefixExpr(e) => {
 468                 let expr = self.collect_expr_opt(e.expr());
 469                 if let Some(op) = e.op_kind() {
 470                     self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr)
 471                 } else {
 472                     self.alloc_expr(Expr::Missing, syntax_ptr)
 473                 }
 474             }
 475             ast::Expr::ClosureExpr(e) => {
 476                 let mut args = Vec::new();
 477                 let mut arg_types = Vec::new();
 478                 if let Some(pl) = e.param_list() {
 479                     for param in pl.params() {
 480                         let pat = self.collect_pat_opt(param.pat());
 481                         let type_ref = param.ty().map(|it| TypeRef::from_ast(&self.ctx(), it));
 482                         args.push(pat);
 483                         arg_types.push(type_ref);
 484                     }
 485                 }
 486                 let ret_type =
 487                     e.ret_type().and_then(|r| r.ty()).map(|it| TypeRef::from_ast(&self.ctx(), it));
 488                 let body = self.collect_expr_opt(e.body());
 489                 self.alloc_expr(Expr::Lambda { args, arg_types, ret_type, body }, syntax_ptr)
 490             }
 491             ast::Expr::BinExpr(e) => {
 492                 let lhs = self.collect_expr_opt(e.lhs());
 493                 let rhs = self.collect_expr_opt(e.rhs());
 494                 let op = e.op_kind().map(BinaryOp::from);
 495                 self.alloc_expr(Expr::BinaryOp { lhs, rhs, op }, syntax_ptr)
 496             }
 497             ast::Expr::TupleExpr(e) => {
 498                 let exprs = e.fields().map(|expr| self.collect_expr(expr)).collect();
 499                 self.alloc_expr(Expr::Tuple { exprs }, syntax_ptr)
 500             }
 501             ast::Expr::BoxExpr(e) => {
 502                 let expr = self.collect_expr_opt(e.expr());
 503                 self.alloc_expr(Expr::Box { expr }, syntax_ptr)
 504             }
 505
 506             ast::Expr::ArrayExpr(e) => {
 507                 let kind = e.kind();
 508
 509                 match kind {
 510                     ArrayExprKind::ElementList(e) => {
 511                         let exprs = e.map(|expr| self.collect_expr(expr)).collect();
 512                         self.alloc_expr(Expr::Array(Array::ElementList(exprs)), syntax_ptr)
 513                     }
 514                     ArrayExprKind::Repeat { initializer, repeat } => {
 515                         let initializer = self.collect_expr_opt(initializer);
 516                         let repeat = self.collect_expr_opt(repeat);
 517                         self.alloc_expr(
 518                             Expr::Array(Array::Repeat { initializer, repeat }),
 519                             syntax_ptr,
 520                         )
 521                     }
 522                 }
 523             }
 524
 525             ast::Expr::Literal(e) => self.alloc_expr(Expr::Literal(e.kind().into()), syntax_ptr),
 526             ast::Expr::IndexExpr(e) => {
 527                 let base = self.collect_expr_opt(e.base());
 528                 let index = self.collect_expr_opt(e.index());
 529                 self.alloc_expr(Expr::Index { base, index }, syntax_ptr)
 530             }
 531             ast::Expr::RangeExpr(e) => {
 532                 let lhs = e.start().map(|lhs| self.collect_expr(lhs));
 533                 let rhs = e.end().map(|rhs| self.collect_expr(rhs));
 534                 match e.op_kind() {
 535                     Some(range_type) => {
 536                         self.alloc_expr(Expr::Range { lhs, rhs, range_type }, syntax_ptr)
 537                     }
 538                     None => self.alloc_expr(Expr::Missing, syntax_ptr),
 539                 }
 540             }
 541             ast::Expr::MacroCall(e) => {
 542                 let mut ids = vec![];
 543                 self.collect_macro_call(e, syntax_ptr.clone(), |this, expansion| {
 544                     ids.push(match expansion {
 545                         Some(it) => this.collect_expr(it),
 546                         None => this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
 547                     })
 548                 });
 549                 ids[0]
 550             }
 551         }
 552     }
 553
 554     fn collect_macro_call<F: FnMut(&mut Self, Option<T>), T: ast::AstNode>(
 555         &mut self,
 556         e: ast::MacroCall,
 557         syntax_ptr: AstPtr<ast::Expr>,
 558         mut collector: F,
 559     ) {
 560         // File containing the macro call. Expansion errors will be attached here.
 561         let outer_file = self.expander.current_file_id;
 562
 563         let macro_call = self.expander.to_source(AstPtr::new(&e));
 564         let res = self.expander.enter_expand(self.db, e);
 565
 566         match &res.err {
 567             Some(ExpandError::UnresolvedProcMacro) => {
 568                 self.source_map.diagnostics.push(BodyDiagnostic::UnresolvedProcMacro(
 569                     UnresolvedProcMacro {
 570                         file: outer_file,
 571                         node: syntax_ptr.into(),
 572                         precise_location: None,
 573                         macro_name: None,
 574                     },
 575                 ));
 576             }
 577             Some(err) => {
 578                 self.source_map.diagnostics.push(BodyDiagnostic::MacroError(MacroError {
 579                     file: outer_file,
 580                     node: syntax_ptr.into(),
 581                     message: err.to_string(),
 582                 }));
 583             }
 584             None => {}
 585         }
 586
 587         match res.value {
 588             Some((mark, expansion)) => {
 589                 // FIXME: Statements are too complicated to recover from error for now.
 590                 // It is because we don't have any hygiene for local variable expansion right now.
 591                 if T::can_cast(syntax::SyntaxKind::MACRO_STMTS) && res.err.is_some() {
 592                     self.expander.exit(self.db, mark);
 593                     collector(self, None);
 594                 } else {
 595                     self.source_map.expansions.insert(macro_call, self.expander.current_file_id);
 596
 597                     let item_tree = self.db.item_tree(self.expander.current_file_id);
 598                     self.item_trees.insert(self.expander.current_file_id, item_tree);
 599
 600                     let id = collector(self, Some(expansion));
 601                     self.expander.exit(self.db, mark);
 602                     id
 603                 }
 604             }
 605             None => collector(self, None),
 606         }
 607     }
 608
 609     fn find_inner_item<N: ItemTreeNode>(&self, ast: &N::Source) -> Option<ItemTreeId<N>> {
 610         let id = self.expander.ast_id(ast);
 611         let tree = &self.item_trees[&id.file_id];
 612
 613         // FIXME: This probably breaks with `use` items, since they produce multiple item tree nodes
 614
 615         // Root file (non-macro).
 616         let item_tree_id = tree
 617             .all_inner_items()
 618             .chain(tree.top_level_items().iter().copied())
 619             .filter_map(|mod_item| mod_item.downcast::<N>())
 620             .find(|tree_id| tree[*tree_id].ast_id().upcast() == id.value.upcast())
 621             .or_else(|| {
 622                 log::debug!(
 623                     "couldn't find inner {} item for {:?} (AST: `{}` - {:?})",
 624                     type_name::<N>(),
 625                     id,
 626                     ast.syntax(),
 627                     ast.syntax(),
 628                 );
 629                 None
 630             })?;
 631
 632         Some(ItemTreeId::new(id.file_id, item_tree_id))
 633     }
 634
 635     fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
 636         if let Some(expr) = expr {
 637             self.collect_expr(expr)
 638         } else {
 639             self.missing_expr()
 640         }
 641     }
 642
 643     fn collect_stmt(&mut self, s: ast::Stmt) -> Option<Vec<Statement>> {
 644         let stmt =
 645             match s {
 646                 ast::Stmt::LetStmt(stmt) => {
 647                     self.check_cfg(&stmt)?;
 648
 649                     let pat = self.collect_pat_opt(stmt.pat());
 650                     let type_ref = stmt.ty().map(|it| TypeRef::from_ast(&self.ctx(), it));
 651                     let initializer = stmt.initializer().map(|e| self.collect_expr(e));
 652                     vec![Statement::Let { pat, type_ref, initializer }]
 653                 }
 654                 ast::Stmt::ExprStmt(stmt) => {
 655                     self.check_cfg(&stmt)?;
 656
 657                     // Note that macro could be expended to multiple statements
 658                     if let Some(ast::Expr::MacroCall(m)) = stmt.expr() {
 659                         let syntax_ptr = AstPtr::new(&stmt.expr().unwrap());
 660                         let mut stmts = vec![];
 661
 662                         self.collect_macro_call(m, syntax_ptr.clone(), |this, expansion| {
 663                             match expansion {
 664                                 Some(expansion) => {
 665                                     let statements: ast::MacroStmts = expansion;
 666                                     this.collect_stmts_items(statements.statements());
 667
 668                                     statements.statements().for_each(|stmt| {
 669                                         if let Some(mut r) = this.collect_stmt(stmt) {
 670                                             stmts.append(&mut r);
 671                                         }
 672                                     });
 673                                     if let Some(expr) = statements.expr() {
 674                                         stmts.push(Statement::Expr(this.collect_expr(expr)));
 675                                     }
 676                                 }
 677                                 None => {
 678                                     stmts.push(Statement::Expr(
 679                                         this.alloc_expr(Expr::Missing, syntax_ptr.clone()),
 680                                     ));
 681                                 }
 682                             }
 683                         });
 684                         stmts
 685                     } else {
 686                         vec![Statement::Expr(self.collect_expr_opt(stmt.expr()))]
 687                     }
 688                 }
 689                 ast::Stmt::Item(item) => {
 690                     self.check_cfg(&item)?;
 691
 692                     return None;
 693                 }
 694             };
 695
 696         Some(stmt)
 697     }
 698
 699     fn collect_block(&mut self, block: ast::BlockExpr) -> ExprId {
 700         let ast_id = self.expander.ast_id(&block);
 701         let block_loc = BlockLoc { ast_id, module: self.expander.module };
 702         let block_id = self.db.intern_block(block_loc);
 703         let def_map = self.db.block_def_map(block_id);
 704         let root = def_map.module_id(def_map.root());
 705         let prev_def_map = mem::replace(&mut self.expander.def_map, def_map);
 706         let prev_module = mem::replace(&mut self.expander.module, root);
 707
 708         self.collect_stmts_items(block.statements());
 709         let statements =
 710             block.statements().filter_map(|s| self.collect_stmt(s)).flatten().collect();
 711         let tail = block.tail_expr().map(|e| self.collect_expr(e));
 712         let syntax_node_ptr = AstPtr::new(&block.clone().into());
 713         let expr_id = self.alloc_expr(
 714             Expr::Block { id: block_id, statements, tail, label: None },
 715             syntax_node_ptr,
 716         );
 717
 718         self.expander.def_map = prev_def_map;
 719         self.expander.module = prev_module;
 720         expr_id
 721     }
 722
 723     fn collect_stmts_items(&mut self, stmts: ast::AstChildren<ast::Stmt>) {
 724         let container = ContainerId::DefWithBodyId(self.def);
 725
 726         let items = stmts
 727             .filter_map(|stmt| match stmt {
 728                 ast::Stmt::Item(it) => Some(it),
 729                 ast::Stmt::LetStmt(_) | ast::Stmt::ExprStmt(_) => None,
 730             })
 731             .filter_map(|item| {
 732                 let (def, name): (ModuleDefId, Option<ast::Name>) = match item {
 733                     ast::Item::Fn(def) => {
 734                         let id = self.find_inner_item(&def)?;
 735                         (
 736                             FunctionLoc { container: container.into(), id }.intern(self.db).into(),
 737                             def.name(),
 738                         )
 739                     }
 740                     ast::Item::TypeAlias(def) => {
 741                         let id = self.find_inner_item(&def)?;
 742                         (
 743                             TypeAliasLoc { container: container.into(), id }.intern(self.db).into(),
 744                             def.name(),
 745                         )
 746                     }
 747                     ast::Item::Const(def) => {
 748                         let id = self.find_inner_item(&def)?;
 749                         (
 750                             ConstLoc { container: container.into(), id }.intern(self.db).into(),
 751                             def.name(),
 752                         )
 753                     }
 754                     ast::Item::Static(def) => {
 755                         let id = self.find_inner_item(&def)?;
 756                         (StaticLoc { container, id }.intern(self.db).into(), def.name())
 757                     }
 758                     ast::Item::Struct(def) => {
 759                         let id = self.find_inner_item(&def)?;
 760                         (StructLoc { container, id }.intern(self.db).into(), def.name())
 761                     }
 762                     ast::Item::Enum(def) => {
 763                         let id = self.find_inner_item(&def)?;
 764                         (EnumLoc { container, id }.intern(self.db).into(), def.name())
 765                     }
 766                     ast::Item::Union(def) => {
 767                         let id = self.find_inner_item(&def)?;
 768                         (UnionLoc { container, id }.intern(self.db).into(), def.name())
 769                     }
 770                     ast::Item::Trait(def) => {
 771                         let id = self.find_inner_item(&def)?;
 772                         (TraitLoc { container, id }.intern(self.db).into(), def.name())
 773                     }
 774                     ast::Item::ExternBlock(_) => return None, // FIXME: collect from extern blocks
 775                     ast::Item::Impl(_)
 776                     | ast::Item::Use(_)
 777                     | ast::Item::ExternCrate(_)
 778                     | ast::Item::Module(_)
 779                     | ast::Item::MacroCall(_) => return None,
 780                     ast::Item::MacroRules(def) => {
 781                         return Some(Either::Right(ast::Macro::from(def)));
 782                     }
 783                     ast::Item::MacroDef(def) => {
 784                         return Some(Either::Right(ast::Macro::from(def)));
 785                     }
 786                 };
 787
 788                 Some(Either::Left((def, name)))
 789             })
 790             .collect::<Vec<_>>();
 791
 792         for either in items {
 793             match either {
 794                 Either::Left((def, name)) => {
 795                     self.body.item_scope.define_def(def);
 796                     if let Some(name) = name {
 797                         let vis = crate::visibility::Visibility::Public; // FIXME determine correctly
 798                         let has_constructor = match def {
 799                             ModuleDefId::AdtId(AdtId::StructId(s)) => {
 800                                 self.db.struct_data(s).variant_data.kind() != StructKind::Record
 801                             }
 802                             _ => true,
 803                         };
 804                         self.body.item_scope.push_res(
 805                             name.as_name(),
 806                             crate::per_ns::PerNs::from_def(def, vis, has_constructor),
 807                         );
 808                     }
 809                 }
 810                 Either::Right(e) => {
 811                     let mac = MacroDefId {
 812                         krate: self.expander.module.krate,
 813                         ast_id: Some(self.expander.ast_id(&e)),
 814                         kind: MacroDefKind::Declarative,
 815                         local_inner: false,
 816                     };
 817                     if let Some(name) = e.name() {
 818                         self.body.item_scope.define_legacy_macro(name.as_name(), mac);
 819                     }
 820                 }
 821             }
 822         }
 823     }
 824
 825     fn collect_block_opt(&mut self, expr: Option<ast::BlockExpr>) -> ExprId {
 826         if let Some(block) = expr {
 827             self.collect_block(block)
 828         } else {
 829             self.missing_expr()
 830         }
 831     }
 832
 833     fn collect_label(&mut self, ast_label: ast::Label) -> LabelId {
 834         let label = Label {
 835             name: ast_label.lifetime().as_ref().map_or_else(Name::missing, Name::new_lifetime),
 836         };
 837         self.alloc_label(label, AstPtr::new(&ast_label))
 838     }
 839
 840     fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
 841         let pattern = match &pat {
 842             ast::Pat::IdentPat(bp) => {
 843                 let name = bp.name().map(|nr| nr.as_name()).unwrap_or_else(Name::missing);
 844                 let annotation =
 845                     BindingAnnotation::new(bp.mut_token().is_some(), bp.ref_token().is_some());
 846                 let subpat = bp.pat().map(|subpat| self.collect_pat(subpat));
 847                 if annotation == BindingAnnotation::Unannotated && subpat.is_none() {
 848                     // This could also be a single-segment path pattern. To
 849                     // decide that, we need to try resolving the name.
 850                     let (resolved, _) = self.expander.def_map.resolve_path(
 851                         self.db,
 852                         self.expander.module.local_id,
 853                         &name.clone().into(),
 854                         BuiltinShadowMode::Other,
 855                     );
 856                     match resolved.take_values() {
 857                         Some(ModuleDefId::ConstId(_)) => Pat::Path(name.into()),
 858                         Some(ModuleDefId::EnumVariantId(_)) => {
 859                             // this is only really valid for unit variants, but
 860                             // shadowing other enum variants with a pattern is
 861                             // an error anyway
 862                             Pat::Path(name.into())
 863                         }
 864                         Some(ModuleDefId::AdtId(AdtId::StructId(s)))
 865                             if self.db.struct_data(s).variant_data.kind() != StructKind::Record =>
 866                         {
 867                             // Funnily enough, record structs *can* be shadowed
 868                             // by pattern bindings (but unit or tuple structs
 869                             // can't).
 870                             Pat::Path(name.into())
 871                         }
 872                         // shadowing statics is an error as well, so we just ignore that case here
 873                         _ => Pat::Bind { name, mode: annotation, subpat },
 874                     }
 875                 } else {
 876                     Pat::Bind { name, mode: annotation, subpat }
 877                 }
 878             }
 879             ast::Pat::TupleStructPat(p) => {
 880                 let path = p.path().and_then(|path| self.expander.parse_path(path));
 881                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 882                 Pat::TupleStruct { path, args, ellipsis }
 883             }
 884             ast::Pat::RefPat(p) => {
 885                 let pat = self.collect_pat_opt(p.pat());
 886                 let mutability = Mutability::from_mutable(p.mut_token().is_some());
 887                 Pat::Ref { pat, mutability }
 888             }
 889             ast::Pat::PathPat(p) => {
 890                 let path = p.path().and_then(|path| self.expander.parse_path(path));
 891                 path.map(Pat::Path).unwrap_or(Pat::Missing)
 892             }
 893             ast::Pat::OrPat(p) => {
 894                 let pats = p.pats().map(|p| self.collect_pat(p)).collect();
 895                 Pat::Or(pats)
 896             }
 897             ast::Pat::ParenPat(p) => return self.collect_pat_opt(p.pat()),
 898             ast::Pat::TuplePat(p) => {
 899                 let (args, ellipsis) = self.collect_tuple_pat(p.fields());
 900                 Pat::Tuple { args, ellipsis }
 901             }
 902             ast::Pat::WildcardPat(_) => Pat::Wild,
 903             ast::Pat::RecordPat(p) => {
 904                 let path = p.path().and_then(|path| self.expander.parse_path(path));
 905                 let args: Vec<_> = p
 906                     .record_pat_field_list()
 907                     .expect("every struct should have a field list")
 908                     .fields()
 909                     .filter_map(|f| {
 910                         let ast_pat = f.pat()?;
 911                         let pat = self.collect_pat(ast_pat);
 912                         let name = f.field_name()?.as_name();
 913                         Some(RecordFieldPat { name, pat })
 914                     })
 915                     .collect();
 916
 917                 let ellipsis = p
 918                     .record_pat_field_list()
 919                     .expect("every struct should have a field list")
 920                     .dotdot_token()
 921                     .is_some();
 922
 923                 Pat::Record { path, args, ellipsis }
 924             }
 925             ast::Pat::SlicePat(p) => {
 926                 let SlicePatComponents { prefix, slice, suffix } = p.components();
 927
 928                 // FIXME properly handle `RestPat`
 929                 Pat::Slice {
 930                     prefix: prefix.into_iter().map(|p| self.collect_pat(p)).collect(),
 931                     slice: slice.map(|p| self.collect_pat(p)),
 932                     suffix: suffix.into_iter().map(|p| self.collect_pat(p)).collect(),
 933                 }
 934             }
 935             ast::Pat::LiteralPat(lit) => {
 936                 if let Some(ast_lit) = lit.literal() {
 937                     let expr = Expr::Literal(ast_lit.kind().into());
 938                     let expr_ptr = AstPtr::new(&ast::Expr::Literal(ast_lit));
 939                     let expr_id = self.alloc_expr(expr, expr_ptr);
 940                     Pat::Lit(expr_id)
 941                 } else {
 942                     Pat::Missing
 943                 }
 944             }
 945             ast::Pat::RestPat(_) => {
 946                 // `RestPat` requires special handling and should not be mapped
 947                 // to a Pat. Here we are using `Pat::Missing` as a fallback for
 948                 // when `RestPat` is mapped to `Pat`, which can easily happen
 949                 // when the source code being analyzed has a malformed pattern
 950                 // which includes `..` in a place where it isn't valid.
 951
 952                 Pat::Missing
 953             }
 954             ast::Pat::BoxPat(boxpat) => {
 955                 let inner = self.collect_pat_opt(boxpat.pat());
 956                 Pat::Box { inner }
 957             }
 958             ast::Pat::ConstBlockPat(const_block_pat) => {
 959                 if let Some(expr) = const_block_pat.block_expr() {
 960                     let expr_id = self.collect_block(expr);
 961                     Pat::ConstBlock(expr_id)
 962                 } else {
 963                     Pat::Missing
 964                 }
 965             }
 966             // FIXME: implement
 967             ast::Pat::RangePat(_) | ast::Pat::MacroPat(_) => Pat::Missing,
 968         };
 969         let ptr = AstPtr::new(&pat);
 970         self.alloc_pat(pattern, Either::Left(ptr))
 971     }
 972
 973     fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
 974         if let Some(pat) = pat {
 975             self.collect_pat(pat)
 976         } else {
 977             self.missing_pat()
 978         }
 979     }
 980
 981     fn collect_tuple_pat(&mut self, args: AstChildren<ast::Pat>) -> (Vec<PatId>, Option<usize>) {
 982         // Find the location of the `..`, if there is one. Note that we do not
 983         // consider the possibility of there being multiple `..` here.
 984         let ellipsis = args.clone().position(|p| matches!(p, ast::Pat::RestPat(_)));
 985         // We want to skip the `..` pattern here, since we account for it above.
 986         let args = args
 987             .filter(|p| !matches!(p, ast::Pat::RestPat(_)))
 988             .map(|p| self.collect_pat(p))
 989             .collect();
 990
 991         (args, ellipsis)
 992     }
 993
 994     /// Returns `None` (and emits diagnostics) when `owner` if `#[cfg]`d out, and `Some(())` when
 995     /// not.
 996     fn check_cfg(&mut self, owner: &dyn ast::AttrsOwner) -> Option<()> {
 997         match self.expander.parse_attrs(self.db, owner).cfg() {
 998             Some(cfg) => {
 999                 if self.expander.cfg_options().check(&cfg) != Some(false) {
1000                     return Some(());
1001                 }
1002
1003                 self.source_map.diagnostics.push(BodyDiagnostic::InactiveCode(InactiveCode {
1004                     file: self.expander.current_file_id,
1005                     node: SyntaxNodePtr::new(owner.syntax()),
1006                     cfg,
1007                     opts: self.expander.cfg_options().clone(),
1008                 }));
1009
1010                 None
1011             }
1012             None => Some(()),
1013         }
1014     }
1015 }
1016
1017 impl From<ast::BinOp> for BinaryOp {
1018     fn from(ast_op: ast::BinOp) -> Self {
1019         match ast_op {
1020             ast::BinOp::BooleanOr => BinaryOp::LogicOp(LogicOp::Or),
1021             ast::BinOp::BooleanAnd => BinaryOp::LogicOp(LogicOp::And),
1022             ast::BinOp::EqualityTest => BinaryOp::CmpOp(CmpOp::Eq { negated: false }),
1023             ast::BinOp::NegatedEqualityTest => BinaryOp::CmpOp(CmpOp::Eq { negated: true }),
1024             ast::BinOp::LesserEqualTest => {
1025                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Less, strict: false })
1026             }
1027             ast::BinOp::GreaterEqualTest => {
1028                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Greater, strict: false })
1029             }
1030             ast::BinOp::LesserTest => {
1031                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Less, strict: true })
1032             }
1033             ast::BinOp::GreaterTest => {
1034                 BinaryOp::CmpOp(CmpOp::Ord { ordering: Ordering::Greater, strict: true })
1035             }
1036             ast::BinOp::Addition => BinaryOp::ArithOp(ArithOp::Add),
1037             ast::BinOp::Multiplication => BinaryOp::ArithOp(ArithOp::Mul),
1038             ast::BinOp::Subtraction => BinaryOp::ArithOp(ArithOp::Sub),
1039             ast::BinOp::Division => BinaryOp::ArithOp(ArithOp::Div),
1040             ast::BinOp::Remainder => BinaryOp::ArithOp(ArithOp::Rem),
1041             ast::BinOp::LeftShift => BinaryOp::ArithOp(ArithOp::Shl),
1042             ast::BinOp::RightShift => BinaryOp::ArithOp(ArithOp::Shr),
1043             ast::BinOp::BitwiseXor => BinaryOp::ArithOp(ArithOp::BitXor),
1044             ast::BinOp::BitwiseOr => BinaryOp::ArithOp(ArithOp::BitOr),
1045             ast::BinOp::BitwiseAnd => BinaryOp::ArithOp(ArithOp::BitAnd),
1046             ast::BinOp::Assignment => BinaryOp::Assignment { op: None },
1047             ast::BinOp::AddAssign => BinaryOp::Assignment { op: Some(ArithOp::Add) },
1048             ast::BinOp::DivAssign => BinaryOp::Assignment { op: Some(ArithOp::Div) },
1049             ast::BinOp::MulAssign => BinaryOp::Assignment { op: Some(ArithOp::Mul) },
1050             ast::BinOp::RemAssign => BinaryOp::Assignment { op: Some(ArithOp::Rem) },
1051             ast::BinOp::ShlAssign => BinaryOp::Assignment { op: Some(ArithOp::Shl) },
1052             ast::BinOp::ShrAssign => BinaryOp::Assignment { op: Some(ArithOp::Shr) },
1053             ast::BinOp::SubAssign => BinaryOp::Assignment { op: Some(ArithOp::Sub) },
1054             ast::BinOp::BitOrAssign => BinaryOp::Assignment { op: Some(ArithOp::BitOr) },
1055             ast::BinOp::BitAndAssign => BinaryOp::Assignment { op: Some(ArithOp::BitAnd) },
1056             ast::BinOp::BitXorAssign => BinaryOp::Assignment { op: Some(ArithOp::BitXor) },
1057         }
1058     }
1059 }
1060
1061 impl From<ast::LiteralKind> for Literal {
1062     fn from(ast_lit_kind: ast::LiteralKind) -> Self {
1063         match ast_lit_kind {
1064             LiteralKind::IntNumber(lit) => {
1065                 if let Some(float_suffix) = lit.suffix().and_then(BuiltinFloat::from_suffix) {
1066                     return Literal::Float(Default::default(), Some(float_suffix));
1067                 }
1068                 let ty = lit.suffix().and_then(|it| BuiltinInt::from_suffix(&it));
1069                 Literal::Int(Default::default(), ty)
1070             }
1071             LiteralKind::FloatNumber(lit) => {
1072                 let ty = lit.suffix().and_then(|it| BuiltinFloat::from_suffix(&it));
1073                 Literal::Float(Default::default(), ty)
1074             }
1075             LiteralKind::ByteString(_) => Literal::ByteString(Default::default()),
1076             LiteralKind::String(_) => Literal::String(Default::default()),
1077             LiteralKind::Byte => Literal::Int(Default::default(), Some(BuiltinInt::U8)),
1078             LiteralKind::Bool(val) => Literal::Bool(val),
1079             LiteralKind::Char => Literal::Char(Default::default()),
1080         }
1081     }
1082 }