crates/hir/src/source_analyzer.rs

   1 //! Lookup hir elements using positions in the source code. This is a lossy
   2 //! transformation: in general, a single source might correspond to several
   3 //! modules, functions, etc, due to macros, cfgs and `#[path=]` attributes on
   4 //! modules.
   5 //!
   6 //! So, this modules should not be used during hir construction, it exists
   7 //! purely for "IDE needs".
   8 use std::{iter::once, sync::Arc};
   9
  10 use hir_def::{
  11     body::{
  12         self,
  13         scope::{ExprScopes, ScopeId},
  14         Body, BodySourceMap,
  15     },
  16     expr::{ExprId, Pat, PatId},
  17     path::{ModPath, Path, PathKind},
  18     resolver::{resolver_for_scope, Resolver, TypeNs, ValueNs},
  19     AsMacroCall, DefWithBodyId, FieldId, FunctionId, LocalFieldId, ModuleDefId, VariantId,
  20 };
  21 use hir_expand::{hygiene::Hygiene, name::AsName, HirFileId, InFile};
  22 use hir_ty::{
  23     diagnostics::{record_literal_missing_fields, record_pattern_missing_fields},
  24     InferenceResult, Interner, Substitution, TyExt, TyLoweringContext,
  25 };
  26 use syntax::{
  27     ast::{self, AstNode},
  28     SyntaxNode, TextRange, TextSize,
  29 };
  30
  31 use crate::{
  32     db::HirDatabase, semantics::PathResolution, Adt, BuiltinType, Const, Field, Function, Local,
  33     MacroDef, ModuleDef, Static, Struct, Trait, Type, TypeAlias, TypeParam, Variant,
  34 };
  35 use base_db::CrateId;
  36
  37 /// `SourceAnalyzer` is a convenience wrapper which exposes HIR API in terms of
  38 /// original source files. It should not be used inside the HIR itself.
  39 #[derive(Debug)]
  40 pub(crate) struct SourceAnalyzer {
  41     pub(crate) file_id: HirFileId,
  42     pub(crate) resolver: Resolver,
  43     body: Option<Arc<Body>>,
  44     body_source_map: Option<Arc<BodySourceMap>>,
  45     infer: Option<Arc<InferenceResult>>,
  46 }
  47
  48 impl SourceAnalyzer {
  49     pub(crate) fn new_for_body(
  50         db: &dyn HirDatabase,
  51         def: DefWithBodyId,
  52         node: InFile<&SyntaxNode>,
  53         offset: Option<TextSize>,
  54     ) -> SourceAnalyzer {
  55         let (body, source_map) = db.body_with_source_map(def);
  56         let scopes = db.expr_scopes(def);
  57         let scope = match offset {
  58             None => scope_for(&scopes, &source_map, node),
  59             Some(offset) => scope_for_offset(db, &scopes, &source_map, node.with_value(offset)),
  60         };
  61         let resolver = resolver_for_scope(db.upcast(), def, scope);
  62         SourceAnalyzer {
  63             resolver,
  64             body: Some(body),
  65             body_source_map: Some(source_map),
  66             infer: Some(db.infer(def)),
  67             file_id: node.file_id,
  68         }
  69     }
  70
  71     pub(crate) fn new_for_resolver(
  72         resolver: Resolver,
  73         node: InFile<&SyntaxNode>,
  74     ) -> SourceAnalyzer {
  75         SourceAnalyzer {
  76             resolver,
  77             body: None,
  78             body_source_map: None,
  79             infer: None,
  80             file_id: node.file_id,
  81         }
  82     }
  83
  84     fn expr_id(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<ExprId> {
  85         let src = match expr {
  86             ast::Expr::MacroCall(call) => {
  87                 self.expand_expr(db, InFile::new(self.file_id, call.clone()))?
  88             }
  89             _ => InFile::new(self.file_id, expr.clone()),
  90         };
  91         let sm = self.body_source_map.as_ref()?;
  92         sm.node_expr(src.as_ref())
  93     }
  94
  95     fn pat_id(&self, pat: &ast::Pat) -> Option<PatId> {
  96         // FIXME: macros, see `expr_id`
  97         let src = InFile { file_id: self.file_id, value: pat };
  98         self.body_source_map.as_ref()?.node_pat(src)
  99     }
 100
 101     fn expand_expr(
 102         &self,
 103         db: &dyn HirDatabase,
 104         expr: InFile<ast::MacroCall>,
 105     ) -> Option<InFile<ast::Expr>> {
 106         let macro_file = self.body_source_map.as_ref()?.node_macro_file(expr.as_ref())?;
 107         let expanded = db.parse_or_expand(macro_file)?;
 108
 109         let res = match ast::MacroCall::cast(expanded.clone()) {
 110             Some(call) => self.expand_expr(db, InFile::new(macro_file, call))?,
 111             _ => InFile::new(macro_file, ast::Expr::cast(expanded)?),
 112         };
 113         Some(res)
 114     }
 115
 116     pub(crate) fn type_of_expr(
 117         &self,
 118         db: &dyn HirDatabase,
 119         expr: &ast::Expr,
 120     ) -> Option<(Type, Option<Type>)> {
 121         let expr_id = self.expr_id(db, expr)?;
 122         let infer = self.infer.as_ref()?;
 123         let coerced = infer
 124             .expr_adjustments
 125             .get(&expr_id)
 126             .and_then(|adjusts| adjusts.last().map(|adjust| adjust.target.clone()));
 127         let ty = infer[expr_id].clone();
 128         let mk_ty = |ty| Type::new_with_resolver(db, &self.resolver, ty);
 129         mk_ty(ty).zip(Some(coerced.and_then(mk_ty)))
 130     }
 131
 132     pub(crate) fn type_of_pat(
 133         &self,
 134         db: &dyn HirDatabase,
 135         pat: &ast::Pat,
 136     ) -> Option<(Type, Option<Type>)> {
 137         let pat_id = self.pat_id(pat)?;
 138         let infer = self.infer.as_ref()?;
 139         let coerced = infer
 140             .pat_adjustments
 141             .get(&pat_id)
 142             .and_then(|adjusts| adjusts.last().map(|adjust| adjust.target.clone()));
 143         let ty = infer[pat_id].clone();
 144         let mk_ty = |ty| Type::new_with_resolver(db, &self.resolver, ty);
 145         mk_ty(ty).zip(Some(coerced.and_then(mk_ty)))
 146     }
 147
 148     pub(crate) fn type_of_self(
 149         &self,
 150         db: &dyn HirDatabase,
 151         param: &ast::SelfParam,
 152     ) -> Option<Type> {
 153         let src = InFile { file_id: self.file_id, value: param };
 154         let pat_id = self.body_source_map.as_ref()?.node_self_param(src)?;
 155         let ty = self.infer.as_ref()?[pat_id].clone();
 156         Type::new_with_resolver(db, &self.resolver, ty)
 157     }
 158
 159     pub(crate) fn resolve_method_call(
 160         &self,
 161         db: &dyn HirDatabase,
 162         call: &ast::MethodCallExpr,
 163     ) -> Option<(FunctionId, Substitution)> {
 164         let expr_id = self.expr_id(db, &call.clone().into())?;
 165         self.infer.as_ref()?.method_resolution(expr_id)
 166     }
 167
 168     pub(crate) fn resolve_field(
 169         &self,
 170         db: &dyn HirDatabase,
 171         field: &ast::FieldExpr,
 172     ) -> Option<Field> {
 173         let expr_id = self.expr_id(db, &field.clone().into())?;
 174         self.infer.as_ref()?.field_resolution(expr_id).map(|it| it.into())
 175     }
 176
 177     pub(crate) fn resolve_record_field(
 178         &self,
 179         db: &dyn HirDatabase,
 180         field: &ast::RecordExprField,
 181     ) -> Option<(Field, Option<Local>, Type)> {
 182         let record_expr = ast::RecordExpr::cast(field.syntax().parent().and_then(|p| p.parent())?)?;
 183         let expr = ast::Expr::from(record_expr);
 184         let expr_id = self.body_source_map.as_ref()?.node_expr(InFile::new(self.file_id, &expr))?;
 185
 186         let local_name = field.field_name()?.as_name();
 187         let local = if field.name_ref().is_some() {
 188             None
 189         } else {
 190             let path = ModPath::from_segments(PathKind::Plain, once(local_name.clone()));
 191             match self.resolver.resolve_path_in_value_ns_fully(db.upcast(), &path) {
 192                 Some(ValueNs::LocalBinding(pat_id)) => {
 193                     Some(Local { pat_id, parent: self.resolver.body_owner()? })
 194                 }
 195                 _ => None,
 196             }
 197         };
 198         let (_, subst) = self.infer.as_ref()?.type_of_expr.get(expr_id)?.as_adt()?;
 199         let variant = self.infer.as_ref()?.variant_resolution_for_expr(expr_id)?;
 200         let variant_data = variant.variant_data(db.upcast());
 201         let field = FieldId { parent: variant, local_id: variant_data.field(&local_name)? };
 202         let field_ty =
 203             db.field_types(variant).get(field.local_id)?.clone().substitute(&Interner, subst);
 204         Some((field.into(), local, Type::new_with_resolver(db, &self.resolver, field_ty)?))
 205     }
 206
 207     pub(crate) fn resolve_record_pat_field(
 208         &self,
 209         db: &dyn HirDatabase,
 210         field: &ast::RecordPatField,
 211     ) -> Option<Field> {
 212         let field_name = field.field_name()?.as_name();
 213         let record_pat = ast::RecordPat::cast(field.syntax().parent().and_then(|p| p.parent())?)?;
 214         let pat_id = self.pat_id(&record_pat.into())?;
 215         let variant = self.infer.as_ref()?.variant_resolution_for_pat(pat_id)?;
 216         let variant_data = variant.variant_data(db.upcast());
 217         let field = FieldId { parent: variant, local_id: variant_data.field(&field_name)? };
 218         Some(field.into())
 219     }
 220
 221     pub(crate) fn resolve_macro_call(
 222         &self,
 223         db: &dyn HirDatabase,
 224         macro_call: InFile<&ast::MacroCall>,
 225     ) -> Option<MacroDef> {
 226         let ctx = body::LowerCtx::new(db.upcast(), macro_call.file_id);
 227         let path = macro_call.value.path().and_then(|ast| Path::from_src(ast, &ctx))?;
 228         self.resolver.resolve_path_as_macro(db.upcast(), path.mod_path()).map(|it| it.into())
 229     }
 230
 231     pub(crate) fn resolve_bind_pat_to_const(
 232         &self,
 233         db: &dyn HirDatabase,
 234         pat: &ast::IdentPat,
 235     ) -> Option<ModuleDef> {
 236         let pat_id = self.pat_id(&pat.clone().into())?;
 237         let body = self.body.as_ref()?;
 238         let path = match &body[pat_id] {
 239             Pat::Path(path) => path,
 240             _ => return None,
 241         };
 242         let res = resolve_hir_path(db, &self.resolver, path)?;
 243         match res {
 244             PathResolution::Def(def) => Some(def),
 245             _ => None,
 246         }
 247     }
 248
 249     pub(crate) fn resolve_path_as_macro(
 250         &self,
 251         db: &dyn HirDatabase,
 252         path: &ast::Path,
 253     ) -> Option<MacroDef> {
 254         // This must be a normal source file rather than macro file.
 255         let hygiene = Hygiene::new(db.upcast(), self.file_id);
 256         let ctx = body::LowerCtx::with_hygiene(db.upcast(), &hygiene);
 257         let hir_path = Path::from_src(path.clone(), &ctx)?;
 258         resolve_hir_path_as_macro(db, &self.resolver, &hir_path)
 259     }
 260
 261     pub(crate) fn resolve_path(
 262         &self,
 263         db: &dyn HirDatabase,
 264         path: &ast::Path,
 265     ) -> Option<PathResolution> {
 266         let parent = || path.syntax().parent();
 267         let mut prefer_value_ns = false;
 268         if let Some(path_expr) = parent().and_then(ast::PathExpr::cast) {
 269             let expr_id = self.expr_id(db, &path_expr.into())?;
 270             let infer = self.infer.as_ref()?;
 271             if let Some(assoc) = infer.assoc_resolutions_for_expr(expr_id) {
 272                 return Some(PathResolution::AssocItem(assoc.into()));
 273             }
 274             if let Some(VariantId::EnumVariantId(variant)) =
 275                 infer.variant_resolution_for_expr(expr_id)
 276             {
 277                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 278             }
 279             prefer_value_ns = true;
 280         }
 281
 282         if let Some(path_pat) = parent().and_then(ast::PathPat::cast) {
 283             let pat_id = self.pat_id(&path_pat.into())?;
 284             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_pat(pat_id) {
 285                 return Some(PathResolution::AssocItem(assoc.into()));
 286             }
 287             if let Some(VariantId::EnumVariantId(variant)) =
 288                 self.infer.as_ref()?.variant_resolution_for_pat(pat_id)
 289             {
 290                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 291             }
 292         }
 293
 294         if let Some(rec_lit) = parent().and_then(ast::RecordExpr::cast) {
 295             let expr_id = self.expr_id(db, &rec_lit.into())?;
 296             if let Some(VariantId::EnumVariantId(variant)) =
 297                 self.infer.as_ref()?.variant_resolution_for_expr(expr_id)
 298             {
 299                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 300             }
 301         }
 302
 303         if let Some(pat) = parent()
 304             .and_then(ast::RecordPat::cast)
 305             .map(ast::Pat::from)
 306             .or_else(|| parent().and_then(ast::TupleStructPat::cast).map(ast::Pat::from))
 307         {
 308             let pat_id = self.pat_id(&pat)?;
 309             if let Some(VariantId::EnumVariantId(variant)) =
 310                 self.infer.as_ref()?.variant_resolution_for_pat(pat_id)
 311             {
 312                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 313             }
 314         }
 315
 316         // This must be a normal source file rather than macro file.
 317         let hygiene = Hygiene::new(db.upcast(), self.file_id);
 318         let ctx = body::LowerCtx::with_hygiene(db.upcast(), &hygiene);
 319         let hir_path = Path::from_src(path.clone(), &ctx)?;
 320
 321         // Case where path is a qualifier of another path, e.g. foo::bar::Baz where we are
 322         // trying to resolve foo::bar.
 323         if let Some(outer_path) = parent().and_then(ast::Path::cast) {
 324             if let Some(qualifier) = outer_path.qualifier() {
 325                 if path == &qualifier {
 326                     return resolve_hir_path_qualifier(db, &self.resolver, &hir_path);
 327                 }
 328             }
 329         }
 330         // Case where path is a qualifier of a use tree, e.g. foo::bar::{Baz, Qux} where we are
 331         // trying to resolve foo::bar.
 332         if let Some(use_tree) = parent().and_then(ast::UseTree::cast) {
 333             if let Some(qualifier) = use_tree.path() {
 334                 if path == &qualifier && use_tree.coloncolon_token().is_some() {
 335                     return resolve_hir_path_qualifier(db, &self.resolver, &hir_path);
 336                 }
 337             }
 338         }
 339
 340         if parent().map_or(false, |it| ast::Visibility::can_cast(it.kind())) {
 341             resolve_hir_path_qualifier(db, &self.resolver, &hir_path)
 342         } else {
 343             resolve_hir_path_(db, &self.resolver, &hir_path, prefer_value_ns)
 344         }
 345     }
 346
 347     pub(crate) fn record_literal_missing_fields(
 348         &self,
 349         db: &dyn HirDatabase,
 350         literal: &ast::RecordExpr,
 351     ) -> Option<Vec<(Field, Type)>> {
 352         let krate = self.resolver.krate()?;
 353         let body = self.body.as_ref()?;
 354         let infer = self.infer.as_ref()?;
 355
 356         let expr_id = self.expr_id(db, &literal.clone().into())?;
 357         let substs = infer.type_of_expr[expr_id].as_adt()?.1;
 358
 359         let (variant, missing_fields, _exhaustive) =
 360             record_literal_missing_fields(db, infer, expr_id, &body[expr_id])?;
 361         let res = self.missing_fields(db, krate, substs, variant, missing_fields);
 362         Some(res)
 363     }
 364
 365     pub(crate) fn record_pattern_missing_fields(
 366         &self,
 367         db: &dyn HirDatabase,
 368         pattern: &ast::RecordPat,
 369     ) -> Option<Vec<(Field, Type)>> {
 370         let krate = self.resolver.krate()?;
 371         let body = self.body.as_ref()?;
 372         let infer = self.infer.as_ref()?;
 373
 374         let pat_id = self.pat_id(&pattern.clone().into())?;
 375         let substs = infer.type_of_pat[pat_id].as_adt()?.1;
 376
 377         let (variant, missing_fields, _exhaustive) =
 378             record_pattern_missing_fields(db, infer, pat_id, &body[pat_id])?;
 379         let res = self.missing_fields(db, krate, substs, variant, missing_fields);
 380         Some(res)
 381     }
 382
 383     fn missing_fields(
 384         &self,
 385         db: &dyn HirDatabase,
 386         krate: CrateId,
 387         substs: &Substitution,
 388         variant: VariantId,
 389         missing_fields: Vec<LocalFieldId>,
 390     ) -> Vec<(Field, Type)> {
 391         let field_types = db.field_types(variant);
 392
 393         missing_fields
 394             .into_iter()
 395             .map(|local_id| {
 396                 let field = FieldId { parent: variant, local_id };
 397                 let ty = field_types[local_id].clone().substitute(&Interner, substs);
 398                 (field.into(), Type::new_with_resolver_inner(db, krate, &self.resolver, ty))
 399             })
 400             .collect()
 401     }
 402
 403     pub(crate) fn expand(
 404         &self,
 405         db: &dyn HirDatabase,
 406         macro_call: InFile<&ast::MacroCall>,
 407     ) -> Option<HirFileId> {
 408         let krate = self.resolver.krate()?;
 409         let macro_call_id = macro_call.as_call_id(db.upcast(), krate, |path| {
 410             self.resolver.resolve_path_as_macro(db.upcast(), &path)
 411         })?;
 412         Some(macro_call_id.as_file()).filter(|it| it.expansion_level(db.upcast()) < 64)
 413     }
 414
 415     pub(crate) fn resolve_variant(
 416         &self,
 417         db: &dyn HirDatabase,
 418         record_lit: ast::RecordExpr,
 419     ) -> Option<VariantId> {
 420         let infer = self.infer.as_ref()?;
 421         let expr_id = self.expr_id(db, &record_lit.into())?;
 422         infer.variant_resolution_for_expr(expr_id)
 423     }
 424 }
 425
 426 fn scope_for(
 427     scopes: &ExprScopes,
 428     source_map: &BodySourceMap,
 429     node: InFile<&SyntaxNode>,
 430 ) -> Option<ScopeId> {
 431     node.value
 432         .ancestors()
 433         .filter_map(ast::Expr::cast)
 434         .filter_map(|it| source_map.node_expr(InFile::new(node.file_id, &it)))
 435         .find_map(|it| scopes.scope_for(it))
 436 }
 437
 438 fn scope_for_offset(
 439     db: &dyn HirDatabase,
 440     scopes: &ExprScopes,
 441     source_map: &BodySourceMap,
 442     offset: InFile<TextSize>,
 443 ) -> Option<ScopeId> {
 444     scopes
 445         .scope_by_expr()
 446         .iter()
 447         .filter_map(|(id, scope)| {
 448             let source = source_map.expr_syntax(*id).ok()?;
 449             // FIXME: correctly handle macro expansion
 450             if source.file_id != offset.file_id {
 451                 return None;
 452             }
 453             let root = source.file_syntax(db.upcast());
 454             let node = source.value.to_node(&root);
 455             Some((node.syntax().text_range(), scope))
 456         })
 457         // find containing scope
 458         .min_by_key(|(expr_range, _scope)| {
 459             (
 460                 !(expr_range.start() <= offset.value && offset.value <= expr_range.end()),
 461                 expr_range.len(),
 462             )
 463         })
 464         .map(|(expr_range, scope)| {
 465             adjust(db, scopes, source_map, expr_range, offset).unwrap_or(*scope)
 466         })
 467 }
 468
 469 // XXX: during completion, cursor might be outside of any particular
 470 // expression. Try to figure out the correct scope...
 471 fn adjust(
 472     db: &dyn HirDatabase,
 473     scopes: &ExprScopes,
 474     source_map: &BodySourceMap,
 475     expr_range: TextRange,
 476     offset: InFile<TextSize>,
 477 ) -> Option<ScopeId> {
 478     let child_scopes = scopes
 479         .scope_by_expr()
 480         .iter()
 481         .filter_map(|(id, scope)| {
 482             let source = source_map.expr_syntax(*id).ok()?;
 483             // FIXME: correctly handle macro expansion
 484             if source.file_id != offset.file_id {
 485                 return None;
 486             }
 487             let root = source.file_syntax(db.upcast());
 488             let node = source.value.to_node(&root);
 489             Some((node.syntax().text_range(), scope))
 490         })
 491         .filter(|&(range, _)| {
 492             range.start() <= offset.value && expr_range.contains_range(range) && range != expr_range
 493         });
 494
 495     child_scopes
 496         .max_by(|&(r1, _), &(r2, _)| {
 497             if r1.contains_range(r2) {
 498                 std::cmp::Ordering::Greater
 499             } else if r2.contains_range(r1) {
 500                 std::cmp::Ordering::Less
 501             } else {
 502                 r1.start().cmp(&r2.start())
 503             }
 504         })
 505         .map(|(_ptr, scope)| *scope)
 506 }
 507
 508 #[inline]
 509 pub(crate) fn resolve_hir_path(
 510     db: &dyn HirDatabase,
 511     resolver: &Resolver,
 512     path: &Path,
 513 ) -> Option<PathResolution> {
 514     resolve_hir_path_(db, resolver, path, false)
 515 }
 516
 517 #[inline]
 518 pub(crate) fn resolve_hir_path_as_macro(
 519     db: &dyn HirDatabase,
 520     resolver: &Resolver,
 521     path: &Path,
 522 ) -> Option<MacroDef> {
 523     resolver.resolve_path_as_macro(db.upcast(), path.mod_path()).map(Into::into)
 524 }
 525
 526 fn resolve_hir_path_(
 527     db: &dyn HirDatabase,
 528     resolver: &Resolver,
 529     path: &Path,
 530     prefer_value_ns: bool,
 531 ) -> Option<PathResolution> {
 532     let types = || {
 533         let (ty, unresolved) = match path.type_anchor() {
 534             Some(type_ref) => {
 535                 let (_, res) = TyLoweringContext::new(db, resolver).lower_ty_ext(type_ref);
 536                 res.map(|ty_ns| (ty_ns, path.segments().first()))
 537             }
 538             None => {
 539                 let (ty, remaining) =
 540                     resolver.resolve_path_in_type_ns(db.upcast(), path.mod_path())?;
 541                 match remaining {
 542                     Some(remaining) if remaining > 1 => None,
 543                     _ => Some((ty, path.segments().get(1))),
 544                 }
 545             }
 546         }?;
 547
 548         // If we are in a TypeNs for a Trait, and we have an unresolved name, try to resolve it as a type
 549         // within the trait's associated types.
 550         if let (Some(unresolved), &TypeNs::TraitId(trait_id)) = (&unresolved, &ty) {
 551             if let Some(type_alias_id) =
 552                 db.trait_data(trait_id).associated_type_by_name(&unresolved.name)
 553             {
 554                 return Some(PathResolution::Def(ModuleDefId::from(type_alias_id).into()));
 555             }
 556         }
 557
 558         let res = match ty {
 559             TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
 560             TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
 561             TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
 562                 PathResolution::Def(Adt::from(it).into())
 563             }
 564             TypeNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
 565             TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
 566             TypeNs::BuiltinType(it) => PathResolution::Def(BuiltinType::from(it).into()),
 567             TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
 568         };
 569         match unresolved {
 570             Some(unresolved) => res
 571                 .assoc_type_shorthand_candidates(db, |name, alias| {
 572                     (name == unresolved.name).then(|| alias)
 573                 })
 574                 .map(TypeAlias::from)
 575                 .map(Into::into)
 576                 .map(PathResolution::Def),
 577             None => Some(res),
 578         }
 579     };
 580
 581     let body_owner = resolver.body_owner();
 582     let values = || {
 583         resolver.resolve_path_in_value_ns_fully(db.upcast(), path.mod_path()).and_then(|val| {
 584             let res = match val {
 585                 ValueNs::LocalBinding(pat_id) => {
 586                     let var = Local { parent: body_owner?, pat_id };
 587                     PathResolution::Local(var)
 588                 }
 589                 ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
 590                 ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
 591                 ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
 592                 ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
 593                 ValueNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
 594                 ValueNs::ImplSelf(impl_id) => PathResolution::SelfType(impl_id.into()),
 595                 ValueNs::GenericParam(it) => PathResolution::ConstParam(it.into()),
 596             };
 597             Some(res)
 598         })
 599     };
 600
 601     let items = || {
 602         resolver
 603             .resolve_module_path_in_items(db.upcast(), path.mod_path())
 604             .take_types()
 605             .map(|it| PathResolution::Def(it.into()))
 606     };
 607
 608     let macros = || {
 609         resolver
 610             .resolve_path_as_macro(db.upcast(), path.mod_path())
 611             .map(|def| PathResolution::Macro(def.into()))
 612     };
 613
 614     if prefer_value_ns { values().or_else(types) } else { types().or_else(values) }
 615         .or_else(items)
 616         .or_else(macros)
 617 }
 618
 619 /// Resolves a path where we know it is a qualifier of another path.
 620 ///
 621 /// For example, if we have:
 622 /// ```
 623 /// mod my {
 624 ///     pub mod foo {
 625 ///         struct Bar;
 626 ///     }
 627 ///
 628 ///     pub fn foo() {}
 629 /// }
 630 /// ```
 631 /// then we know that `foo` in `my::foo::Bar` refers to the module, not the function.
 632 fn resolve_hir_path_qualifier(
 633     db: &dyn HirDatabase,
 634     resolver: &Resolver,
 635     path: &Path,
 636 ) -> Option<PathResolution> {
 637     let items = resolver
 638         .resolve_module_path_in_items(db.upcast(), path.mod_path())
 639         .take_types()
 640         .map(|it| PathResolution::Def(it.into()));
 641
 642     if items.is_some() {
 643         return items;
 644     }
 645
 646     resolver.resolve_path_in_type_ns_fully(db.upcast(), path.mod_path()).map(|ty| match ty {
 647         TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
 648         TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
 649         TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => PathResolution::Def(Adt::from(it).into()),
 650         TypeNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
 651         TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
 652         TypeNs::BuiltinType(it) => PathResolution::Def(BuiltinType::from(it).into()),
 653         TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
 654     })
 655 }