crates/hir_def/src/body/lower.rs

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