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, 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(
 250         &self,
 251         db: &dyn HirDatabase,
 252         path: &ast::Path,
 253     ) -> Option<PathResolution> {
 254         let parent = || path.syntax().parent();
 255         let mut prefer_value_ns = false;
 256         if let Some(path_expr) = parent().and_then(ast::PathExpr::cast) {
 257             let expr_id = self.expr_id(db, &path_expr.into())?;
 258             let infer = self.infer.as_ref()?;
 259             if let Some(assoc) = infer.assoc_resolutions_for_expr(expr_id) {
 260                 return Some(PathResolution::AssocItem(assoc.into()));
 261             }
 262             if let Some(VariantId::EnumVariantId(variant)) =
 263                 infer.variant_resolution_for_expr(expr_id)
 264             {
 265                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 266             }
 267             prefer_value_ns = true;
 268         }
 269
 270         if let Some(path_pat) = parent().and_then(ast::PathPat::cast) {
 271             let pat_id = self.pat_id(&path_pat.into())?;
 272             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_pat(pat_id) {
 273                 return Some(PathResolution::AssocItem(assoc.into()));
 274             }
 275             if let Some(VariantId::EnumVariantId(variant)) =
 276                 self.infer.as_ref()?.variant_resolution_for_pat(pat_id)
 277             {
 278                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 279             }
 280         }
 281
 282         if let Some(rec_lit) = parent().and_then(ast::RecordExpr::cast) {
 283             let expr_id = self.expr_id(db, &rec_lit.into())?;
 284             if let Some(VariantId::EnumVariantId(variant)) =
 285                 self.infer.as_ref()?.variant_resolution_for_expr(expr_id)
 286             {
 287                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 288             }
 289         }
 290
 291         if let Some(pat) = parent()
 292             .and_then(ast::RecordPat::cast)
 293             .map(ast::Pat::from)
 294             .or_else(|| parent().and_then(ast::TupleStructPat::cast).map(ast::Pat::from))
 295         {
 296             let pat_id = self.pat_id(&pat)?;
 297             if let Some(VariantId::EnumVariantId(variant)) =
 298                 self.infer.as_ref()?.variant_resolution_for_pat(pat_id)
 299             {
 300                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 301             }
 302         }
 303
 304         // This must be a normal source file rather than macro file.
 305         let hygiene = Hygiene::new(db.upcast(), self.file_id);
 306         let ctx = body::LowerCtx::with_hygiene(db.upcast(), &hygiene);
 307         let hir_path = Path::from_src(path.clone(), &ctx)?;
 308
 309         // Case where path is a qualifier of another path, e.g. foo::bar::Baz where we are
 310         // trying to resolve foo::bar.
 311         if let Some(outer_path) = parent().and_then(ast::Path::cast) {
 312             if let Some(qualifier) = outer_path.qualifier() {
 313                 if path == &qualifier {
 314                     return resolve_hir_path_qualifier(db, &self.resolver, &hir_path);
 315                 }
 316             }
 317         }
 318         // Case where path is a qualifier of a use tree, e.g. foo::bar::{Baz, Qux} where we are
 319         // trying to resolve foo::bar.
 320         if let Some(use_tree) = parent().and_then(ast::UseTree::cast) {
 321             if let Some(qualifier) = use_tree.path() {
 322                 if path == &qualifier && use_tree.coloncolon_token().is_some() {
 323                     return resolve_hir_path_qualifier(db, &self.resolver, &hir_path);
 324                 }
 325             }
 326         }
 327
 328         if parent().map_or(false, |it| ast::Visibility::can_cast(it.kind())) {
 329             resolve_hir_path_qualifier(db, &self.resolver, &hir_path)
 330         } else {
 331             resolve_hir_path_(db, &self.resolver, &hir_path, prefer_value_ns)
 332         }
 333     }
 334
 335     pub(crate) fn record_literal_missing_fields(
 336         &self,
 337         db: &dyn HirDatabase,
 338         literal: &ast::RecordExpr,
 339     ) -> Option<Vec<(Field, Type)>> {
 340         let krate = self.resolver.krate()?;
 341         let body = self.body.as_ref()?;
 342         let infer = self.infer.as_ref()?;
 343
 344         let expr_id = self.expr_id(db, &literal.clone().into())?;
 345         let substs = infer.type_of_expr[expr_id].as_adt()?.1;
 346
 347         let (variant, missing_fields, _exhaustive) =
 348             record_literal_missing_fields(db, infer, expr_id, &body[expr_id])?;
 349         let res = self.missing_fields(db, krate, substs, variant, missing_fields);
 350         Some(res)
 351     }
 352
 353     pub(crate) fn record_pattern_missing_fields(
 354         &self,
 355         db: &dyn HirDatabase,
 356         pattern: &ast::RecordPat,
 357     ) -> Option<Vec<(Field, Type)>> {
 358         let krate = self.resolver.krate()?;
 359         let body = self.body.as_ref()?;
 360         let infer = self.infer.as_ref()?;
 361
 362         let pat_id = self.pat_id(&pattern.clone().into())?;
 363         let substs = infer.type_of_pat[pat_id].as_adt()?.1;
 364
 365         let (variant, missing_fields, _exhaustive) =
 366             record_pattern_missing_fields(db, infer, pat_id, &body[pat_id])?;
 367         let res = self.missing_fields(db, krate, substs, variant, missing_fields);
 368         Some(res)
 369     }
 370
 371     fn missing_fields(
 372         &self,
 373         db: &dyn HirDatabase,
 374         krate: CrateId,
 375         substs: &Substitution,
 376         variant: VariantId,
 377         missing_fields: Vec<LocalFieldId>,
 378     ) -> Vec<(Field, Type)> {
 379         let field_types = db.field_types(variant);
 380
 381         missing_fields
 382             .into_iter()
 383             .map(|local_id| {
 384                 let field = FieldId { parent: variant, local_id };
 385                 let ty = field_types[local_id].clone().substitute(&Interner, substs);
 386                 (field.into(), Type::new_with_resolver_inner(db, krate, &self.resolver, ty))
 387             })
 388             .collect()
 389     }
 390
 391     pub(crate) fn expand(
 392         &self,
 393         db: &dyn HirDatabase,
 394         macro_call: InFile<&ast::MacroCall>,
 395     ) -> Option<HirFileId> {
 396         let krate = self.resolver.krate()?;
 397         let macro_call_id = macro_call.as_call_id(db.upcast(), krate, |path| {
 398             self.resolver.resolve_path_as_macro(db.upcast(), &path)
 399         })?;
 400         Some(macro_call_id.as_file()).filter(|it| it.expansion_level(db.upcast()) < 64)
 401     }
 402
 403     pub(crate) fn resolve_variant(
 404         &self,
 405         db: &dyn HirDatabase,
 406         record_lit: ast::RecordExpr,
 407     ) -> Option<VariantId> {
 408         let infer = self.infer.as_ref()?;
 409         let expr_id = self.expr_id(db, &record_lit.into())?;
 410         infer.variant_resolution_for_expr(expr_id)
 411     }
 412 }
 413
 414 fn scope_for(
 415     scopes: &ExprScopes,
 416     source_map: &BodySourceMap,
 417     node: InFile<&SyntaxNode>,
 418 ) -> Option<ScopeId> {
 419     node.value
 420         .ancestors()
 421         .filter_map(ast::Expr::cast)
 422         .filter_map(|it| source_map.node_expr(InFile::new(node.file_id, &it)))
 423         .find_map(|it| scopes.scope_for(it))
 424 }
 425
 426 fn scope_for_offset(
 427     db: &dyn HirDatabase,
 428     scopes: &ExprScopes,
 429     source_map: &BodySourceMap,
 430     offset: InFile<TextSize>,
 431 ) -> Option<ScopeId> {
 432     scopes
 433         .scope_by_expr()
 434         .iter()
 435         .filter_map(|(id, scope)| {
 436             let source = source_map.expr_syntax(*id).ok()?;
 437             // FIXME: correctly handle macro expansion
 438             if source.file_id != offset.file_id {
 439                 return None;
 440             }
 441             let root = source.file_syntax(db.upcast());
 442             let node = source.value.to_node(&root);
 443             Some((node.syntax().text_range(), scope))
 444         })
 445         // find containing scope
 446         .min_by_key(|(expr_range, _scope)| {
 447             (
 448                 !(expr_range.start() <= offset.value && offset.value <= expr_range.end()),
 449                 expr_range.len(),
 450             )
 451         })
 452         .map(|(expr_range, scope)| {
 453             adjust(db, scopes, source_map, expr_range, offset).unwrap_or(*scope)
 454         })
 455 }
 456
 457 // XXX: during completion, cursor might be outside of any particular
 458 // expression. Try to figure out the correct scope...
 459 fn adjust(
 460     db: &dyn HirDatabase,
 461     scopes: &ExprScopes,
 462     source_map: &BodySourceMap,
 463     expr_range: TextRange,
 464     offset: InFile<TextSize>,
 465 ) -> Option<ScopeId> {
 466     let child_scopes = scopes
 467         .scope_by_expr()
 468         .iter()
 469         .filter_map(|(id, scope)| {
 470             let source = source_map.expr_syntax(*id).ok()?;
 471             // FIXME: correctly handle macro expansion
 472             if source.file_id != offset.file_id {
 473                 return None;
 474             }
 475             let root = source.file_syntax(db.upcast());
 476             let node = source.value.to_node(&root);
 477             Some((node.syntax().text_range(), scope))
 478         })
 479         .filter(|&(range, _)| {
 480             range.start() <= offset.value && expr_range.contains_range(range) && range != expr_range
 481         });
 482
 483     child_scopes
 484         .max_by(|&(r1, _), &(r2, _)| {
 485             if r1.contains_range(r2) {
 486                 std::cmp::Ordering::Greater
 487             } else if r2.contains_range(r1) {
 488                 std::cmp::Ordering::Less
 489             } else {
 490                 r1.start().cmp(&r2.start())
 491             }
 492         })
 493         .map(|(_ptr, scope)| *scope)
 494 }
 495
 496 #[inline]
 497 pub(crate) fn resolve_hir_path(
 498     db: &dyn HirDatabase,
 499     resolver: &Resolver,
 500     path: &Path,
 501 ) -> Option<PathResolution> {
 502     resolve_hir_path_(db, resolver, path, false)
 503 }
 504
 505 fn resolve_hir_path_(
 506     db: &dyn HirDatabase,
 507     resolver: &Resolver,
 508     path: &Path,
 509     prefer_value_ns: bool,
 510 ) -> Option<PathResolution> {
 511     let types = || {
 512         let (ty, unresolved) = match path.type_anchor() {
 513             Some(type_ref) => {
 514                 let (_, res) = TyLoweringContext::new(db, resolver).lower_ty_ext(type_ref);
 515                 res.map(|ty_ns| (ty_ns, path.segments().first()))
 516             }
 517             None => {
 518                 let (ty, remaining) =
 519                     resolver.resolve_path_in_type_ns(db.upcast(), path.mod_path())?;
 520                 match remaining {
 521                     Some(remaining) if remaining > 1 => None,
 522                     _ => Some((ty, path.segments().get(1))),
 523                 }
 524             }
 525         }?;
 526         let res = match ty {
 527             TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
 528             TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
 529             TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
 530                 PathResolution::Def(Adt::from(it).into())
 531             }
 532             TypeNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
 533             TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
 534             TypeNs::BuiltinType(it) => PathResolution::Def(BuiltinType::from(it).into()),
 535             TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
 536         };
 537         match unresolved {
 538             Some(unresolved) => res
 539                 .assoc_type_shorthand_candidates(db, |name, alias| {
 540                     (name == unresolved.name).then(|| alias)
 541                 })
 542                 .map(TypeAlias::from)
 543                 .map(Into::into)
 544                 .map(PathResolution::Def),
 545             None => Some(res),
 546         }
 547     };
 548
 549     let body_owner = resolver.body_owner();
 550     let values = || {
 551         resolver.resolve_path_in_value_ns_fully(db.upcast(), path.mod_path()).and_then(|val| {
 552             let res = match val {
 553                 ValueNs::LocalBinding(pat_id) => {
 554                     let var = Local { parent: body_owner?, pat_id };
 555                     PathResolution::Local(var)
 556                 }
 557                 ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
 558                 ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
 559                 ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
 560                 ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
 561                 ValueNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
 562                 ValueNs::ImplSelf(impl_id) => PathResolution::SelfType(impl_id.into()),
 563                 ValueNs::GenericParam(it) => PathResolution::ConstParam(it.into()),
 564             };
 565             Some(res)
 566         })
 567     };
 568
 569     let items = || {
 570         resolver
 571             .resolve_module_path_in_items(db.upcast(), path.mod_path())
 572             .take_types()
 573             .map(|it| PathResolution::Def(it.into()))
 574     };
 575
 576     let macros = || {
 577         resolver
 578             .resolve_path_as_macro(db.upcast(), path.mod_path())
 579             .map(|def| PathResolution::Macro(def.into()))
 580     };
 581
 582     if prefer_value_ns { values().or_else(types) } else { types().or_else(values) }
 583         .or_else(items)
 584         .or_else(macros)
 585 }
 586
 587 /// Resolves a path where we know it is a qualifier of another path.
 588 ///
 589 /// For example, if we have:
 590 /// ```
 591 /// mod my {
 592 ///     pub mod foo {
 593 ///         struct Bar;
 594 ///     }
 595 ///
 596 ///     pub fn foo() {}
 597 /// }
 598 /// ```
 599 /// then we know that `foo` in `my::foo::Bar` refers to the module, not the function.
 600 fn resolve_hir_path_qualifier(
 601     db: &dyn HirDatabase,
 602     resolver: &Resolver,
 603     path: &Path,
 604 ) -> Option<PathResolution> {
 605     let items = resolver
 606         .resolve_module_path_in_items(db.upcast(), path.mod_path())
 607         .take_types()
 608         .map(|it| PathResolution::Def(it.into()));
 609
 610     if items.is_some() {
 611         return items;
 612     }
 613
 614     resolver.resolve_path_in_type_ns_fully(db.upcast(), path.mod_path()).map(|ty| match ty {
 615         TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
 616         TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
 617         TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => PathResolution::Def(Adt::from(it).into()),
 618         TypeNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
 619         TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
 620         TypeNs::BuiltinType(it) => PathResolution::Def(BuiltinType::from(it).into()),
 621         TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
 622     })
 623 }