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