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, BuiltinAttr, BuiltinType, Const, Field,
  33     Function, Local, MacroDef, ModuleDef, Static, Struct, Tool, Trait, Type, TypeAlias, TypeParam,
  34     Variant,
  35 };
  36 use base_db::CrateId;
  37
  38 /// `SourceAnalyzer` is a convenience wrapper which exposes HIR API in terms of
  39 /// original source files. It should not be used inside the HIR itself.
  40 #[derive(Debug)]
  41 pub(crate) struct SourceAnalyzer {
  42     pub(crate) file_id: HirFileId,
  43     pub(crate) resolver: Resolver,
  44     body: Option<Arc<Body>>,
  45     body_source_map: Option<Arc<BodySourceMap>>,
  46     infer: Option<Arc<InferenceResult>>,
  47 }
  48
  49 impl SourceAnalyzer {
  50     pub(crate) fn new_for_body(
  51         db: &dyn HirDatabase,
  52         def: DefWithBodyId,
  53         node: InFile<&SyntaxNode>,
  54         offset: Option<TextSize>,
  55     ) -> SourceAnalyzer {
  56         let (body, source_map) = db.body_with_source_map(def);
  57         let scopes = db.expr_scopes(def);
  58         let scope = match offset {
  59             None => scope_for(&scopes, &source_map, node),
  60             Some(offset) => scope_for_offset(db, &scopes, &source_map, node.with_value(offset)),
  61         };
  62         let resolver = resolver_for_scope(db.upcast(), def, scope);
  63         SourceAnalyzer {
  64             resolver,
  65             body: Some(body),
  66             body_source_map: Some(source_map),
  67             infer: Some(db.infer(def)),
  68             file_id: node.file_id,
  69         }
  70     }
  71
  72     pub(crate) fn new_for_resolver(
  73         resolver: Resolver,
  74         node: InFile<&SyntaxNode>,
  75     ) -> SourceAnalyzer {
  76         SourceAnalyzer {
  77             resolver,
  78             body: None,
  79             body_source_map: None,
  80             infer: None,
  81             file_id: node.file_id,
  82         }
  83     }
  84
  85     fn expr_id(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<ExprId> {
  86         let src = match expr {
  87             ast::Expr::MacroCall(call) => {
  88                 self.expand_expr(db, InFile::new(self.file_id, call.clone()))?
  89             }
  90             _ => InFile::new(self.file_id, expr.clone()),
  91         };
  92         let sm = self.body_source_map.as_ref()?;
  93         sm.node_expr(src.as_ref())
  94     }
  95
  96     fn pat_id(&self, pat: &ast::Pat) -> Option<PatId> {
  97         // FIXME: macros, see `expr_id`
  98         let src = InFile { file_id: self.file_id, value: pat };
  99         self.body_source_map.as_ref()?.node_pat(src)
 100     }
 101
 102     fn expand_expr(
 103         &self,
 104         db: &dyn HirDatabase,
 105         expr: InFile<ast::MacroCall>,
 106     ) -> Option<InFile<ast::Expr>> {
 107         let macro_file = self.body_source_map.as_ref()?.node_macro_file(expr.as_ref())?;
 108         let expanded = db.parse_or_expand(macro_file)?;
 109
 110         let res = match ast::MacroCall::cast(expanded.clone()) {
 111             Some(call) => self.expand_expr(db, InFile::new(macro_file, call))?,
 112             _ => InFile::new(macro_file, ast::Expr::cast(expanded)?),
 113         };
 114         Some(res)
 115     }
 116
 117     pub(crate) fn type_of_expr(
 118         &self,
 119         db: &dyn HirDatabase,
 120         expr: &ast::Expr,
 121     ) -> Option<(Type, Option<Type>)> {
 122         let expr_id = self.expr_id(db, expr)?;
 123         let infer = self.infer.as_ref()?;
 124         let coerced = infer
 125             .expr_adjustments
 126             .get(&expr_id)
 127             .and_then(|adjusts| adjusts.last().map(|adjust| adjust.target.clone()));
 128         let ty = infer[expr_id].clone();
 129         let mk_ty = |ty| Type::new_with_resolver(db, &self.resolver, ty);
 130         mk_ty(ty).zip(Some(coerced.and_then(mk_ty)))
 131     }
 132
 133     pub(crate) fn type_of_pat(
 134         &self,
 135         db: &dyn HirDatabase,
 136         pat: &ast::Pat,
 137     ) -> Option<(Type, Option<Type>)> {
 138         let pat_id = self.pat_id(pat)?;
 139         let infer = self.infer.as_ref()?;
 140         let coerced = infer
 141             .pat_adjustments
 142             .get(&pat_id)
 143             .and_then(|adjusts| adjusts.last().map(|adjust| adjust.target.clone()));
 144         let ty = infer[pat_id].clone();
 145         let mk_ty = |ty| Type::new_with_resolver(db, &self.resolver, ty);
 146         mk_ty(ty).zip(Some(coerced.and_then(mk_ty)))
 147     }
 148
 149     pub(crate) fn type_of_self(
 150         &self,
 151         db: &dyn HirDatabase,
 152         param: &ast::SelfParam,
 153     ) -> Option<Type> {
 154         let src = InFile { file_id: self.file_id, value: param };
 155         let pat_id = self.body_source_map.as_ref()?.node_self_param(src)?;
 156         let ty = self.infer.as_ref()?[pat_id].clone();
 157         Type::new_with_resolver(db, &self.resolver, ty)
 158     }
 159
 160     pub(crate) fn resolve_method_call(
 161         &self,
 162         db: &dyn HirDatabase,
 163         call: &ast::MethodCallExpr,
 164     ) -> Option<(FunctionId, Substitution)> {
 165         let expr_id = self.expr_id(db, &call.clone().into())?;
 166         self.infer.as_ref()?.method_resolution(expr_id)
 167     }
 168
 169     pub(crate) fn resolve_field(
 170         &self,
 171         db: &dyn HirDatabase,
 172         field: &ast::FieldExpr,
 173     ) -> Option<Field> {
 174         let expr_id = self.expr_id(db, &field.clone().into())?;
 175         self.infer.as_ref()?.field_resolution(expr_id).map(|it| it.into())
 176     }
 177
 178     pub(crate) fn resolve_record_field(
 179         &self,
 180         db: &dyn HirDatabase,
 181         field: &ast::RecordExprField,
 182     ) -> Option<(Field, Option<Local>, Type)> {
 183         let record_expr = ast::RecordExpr::cast(field.syntax().parent().and_then(|p| p.parent())?)?;
 184         let expr = ast::Expr::from(record_expr);
 185         let expr_id = self.body_source_map.as_ref()?.node_expr(InFile::new(self.file_id, &expr))?;
 186
 187         let local_name = field.field_name()?.as_name();
 188         let local = if field.name_ref().is_some() {
 189             None
 190         } else {
 191             let path = ModPath::from_segments(PathKind::Plain, once(local_name.clone()));
 192             match self.resolver.resolve_path_in_value_ns_fully(db.upcast(), &path) {
 193                 Some(ValueNs::LocalBinding(pat_id)) => {
 194                     Some(Local { pat_id, parent: self.resolver.body_owner()? })
 195                 }
 196                 _ => None,
 197             }
 198         };
 199         let (_, subst) = self.infer.as_ref()?.type_of_expr.get(expr_id)?.as_adt()?;
 200         let variant = self.infer.as_ref()?.variant_resolution_for_expr(expr_id)?;
 201         let variant_data = variant.variant_data(db.upcast());
 202         let field = FieldId { parent: variant, local_id: variant_data.field(&local_name)? };
 203         let field_ty =
 204             db.field_types(variant).get(field.local_id)?.clone().substitute(&Interner, subst);
 205         Some((field.into(), local, Type::new_with_resolver(db, &self.resolver, field_ty)?))
 206     }
 207
 208     pub(crate) fn resolve_record_pat_field(
 209         &self,
 210         db: &dyn HirDatabase,
 211         field: &ast::RecordPatField,
 212     ) -> Option<Field> {
 213         let field_name = field.field_name()?.as_name();
 214         let record_pat = ast::RecordPat::cast(field.syntax().parent().and_then(|p| p.parent())?)?;
 215         let pat_id = self.pat_id(&record_pat.into())?;
 216         let variant = self.infer.as_ref()?.variant_resolution_for_pat(pat_id)?;
 217         let variant_data = variant.variant_data(db.upcast());
 218         let field = FieldId { parent: variant, local_id: variant_data.field(&field_name)? };
 219         Some(field.into())
 220     }
 221
 222     pub(crate) fn resolve_macro_call(
 223         &self,
 224         db: &dyn HirDatabase,
 225         macro_call: InFile<&ast::MacroCall>,
 226     ) -> Option<MacroDef> {
 227         let ctx = body::LowerCtx::new(db.upcast(), macro_call.file_id);
 228         let path = macro_call.value.path().and_then(|ast| Path::from_src(ast, &ctx))?;
 229         self.resolver.resolve_path_as_macro(db.upcast(), path.mod_path()).map(|it| it.into())
 230     }
 231
 232     pub(crate) fn resolve_bind_pat_to_const(
 233         &self,
 234         db: &dyn HirDatabase,
 235         pat: &ast::IdentPat,
 236     ) -> Option<ModuleDef> {
 237         let pat_id = self.pat_id(&pat.clone().into())?;
 238         let body = self.body.as_ref()?;
 239         let path = match &body[pat_id] {
 240             Pat::Path(path) => path,
 241             _ => return None,
 242         };
 243         let res = resolve_hir_path(db, &self.resolver, path)?;
 244         match res {
 245             PathResolution::Def(def) => Some(def),
 246             _ => None,
 247         }
 248     }
 249
 250     pub(crate) fn resolve_path(
 251         &self,
 252         db: &dyn HirDatabase,
 253         path: &ast::Path,
 254     ) -> Option<PathResolution> {
 255         let parent = path.syntax().parent();
 256         let parent = || parent.clone();
 257
 258         let mut prefer_value_ns = false;
 259         if let Some(path_expr) = parent().and_then(ast::PathExpr::cast) {
 260             let expr_id = self.expr_id(db, &path_expr.into())?;
 261             let infer = self.infer.as_ref()?;
 262             if let Some(assoc) = infer.assoc_resolutions_for_expr(expr_id) {
 263                 return Some(PathResolution::AssocItem(assoc.into()));
 264             }
 265             if let Some(VariantId::EnumVariantId(variant)) =
 266                 infer.variant_resolution_for_expr(expr_id)
 267             {
 268                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 269             }
 270             prefer_value_ns = true;
 271         }
 272
 273         if let Some(path_pat) = parent().and_then(ast::PathPat::cast) {
 274             let pat_id = self.pat_id(&path_pat.into())?;
 275             if let Some(assoc) = self.infer.as_ref()?.assoc_resolutions_for_pat(pat_id) {
 276                 return Some(PathResolution::AssocItem(assoc.into()));
 277             }
 278             if let Some(VariantId::EnumVariantId(variant)) =
 279                 self.infer.as_ref()?.variant_resolution_for_pat(pat_id)
 280             {
 281                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 282             }
 283         }
 284
 285         if let Some(rec_lit) = parent().and_then(ast::RecordExpr::cast) {
 286             let expr_id = self.expr_id(db, &rec_lit.into())?;
 287             if let Some(VariantId::EnumVariantId(variant)) =
 288                 self.infer.as_ref()?.variant_resolution_for_expr(expr_id)
 289             {
 290                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 291             }
 292         }
 293
 294         if let Some(pat) = parent()
 295             .and_then(ast::RecordPat::cast)
 296             .map(ast::Pat::from)
 297             .or_else(|| parent().and_then(ast::TupleStructPat::cast).map(ast::Pat::from))
 298         {
 299             let pat_id = self.pat_id(&pat)?;
 300             if let Some(VariantId::EnumVariantId(variant)) =
 301                 self.infer.as_ref()?.variant_resolution_for_pat(pat_id)
 302             {
 303                 return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
 304             }
 305         }
 306
 307         // This must be a normal source file rather than macro file.
 308         let hygiene = Hygiene::new(db.upcast(), self.file_id);
 309         let ctx = body::LowerCtx::with_hygiene(db.upcast(), &hygiene);
 310         let hir_path = Path::from_src(path.clone(), &ctx)?;
 311
 312         // Case where path is a qualifier of a use tree, e.g. foo::bar::{Baz, Qux} where we are
 313         // trying to resolve foo::bar.
 314         if let Some(use_tree) = parent().and_then(ast::UseTree::cast) {
 315             if let Some(qualifier) = use_tree.path() {
 316                 if path == &qualifier && use_tree.coloncolon_token().is_some() {
 317                     return resolve_hir_path_qualifier(db, &self.resolver, &hir_path);
 318                 }
 319             }
 320         }
 321
 322         let is_path_of_attr = path
 323             .top_path()
 324             .syntax()
 325             .ancestors()
 326             .nth(2) // Path -> Meta -> Attr
 327             .map_or(false, |it| ast::Attr::can_cast(it.kind()));
 328
 329         // Case where path is a qualifier of another path, e.g. foo::bar::Baz where we are
 330         // trying to resolve foo::bar.
 331         if let Some(outer_path) = path.parent_path() {
 332             if let Some(qualifier) = outer_path.qualifier() {
 333                 if path == &qualifier {
 334                     return resolve_hir_path_qualifier(db, &self.resolver, &hir_path);
 335                 }
 336             }
 337         } else if is_path_of_attr {
 338             let res = resolve_hir_path_as_macro(db, &self.resolver, &hir_path);
 339             return match res {
 340                 Some(_) => res.map(PathResolution::Macro),
 341                 None => path.as_single_name_ref().and_then(|name_ref| {
 342                     if let builtin @ Some(_) = BuiltinAttr::by_name(&name_ref.text()) {
 343                         builtin.map(PathResolution::BuiltinAttr)
 344                     } else if let tool @ Some(_) = Tool::by_name(&name_ref.text()) {
 345                         tool.map(PathResolution::Tool)
 346                     } else {
 347                         None
 348                     }
 349                 }),
 350             };
 351         }
 352
 353         let res = if parent().map_or(false, |it| ast::Visibility::can_cast(it.kind())) {
 354             resolve_hir_path_qualifier(db, &self.resolver, &hir_path)
 355         } else {
 356             resolve_hir_path_(db, &self.resolver, &hir_path, prefer_value_ns)
 357         };
 358         match res {
 359             Some(_) => res,
 360             // this labels any path that starts with a tool module as the tool itself, this is technically wrong
 361             // but there is no benefit in differentiating these two cases for the time being
 362             None if is_path_of_attr => path
 363                 .first_segment()
 364                 .and_then(|seg| seg.name_ref())
 365                 .and_then(|name_ref| Tool::by_name(&name_ref.text()))
 366                 .map(PathResolution::Tool),
 367             None => None,
 368         }
 369     }
 370
 371     pub(crate) fn record_literal_missing_fields(
 372         &self,
 373         db: &dyn HirDatabase,
 374         literal: &ast::RecordExpr,
 375     ) -> Option<Vec<(Field, Type)>> {
 376         let krate = self.resolver.krate()?;
 377         let body = self.body.as_ref()?;
 378         let infer = self.infer.as_ref()?;
 379
 380         let expr_id = self.expr_id(db, &literal.clone().into())?;
 381         let substs = infer.type_of_expr[expr_id].as_adt()?.1;
 382
 383         let (variant, missing_fields, _exhaustive) =
 384             record_literal_missing_fields(db, infer, expr_id, &body[expr_id])?;
 385         let res = self.missing_fields(db, krate, substs, variant, missing_fields);
 386         Some(res)
 387     }
 388
 389     pub(crate) fn record_pattern_missing_fields(
 390         &self,
 391         db: &dyn HirDatabase,
 392         pattern: &ast::RecordPat,
 393     ) -> Option<Vec<(Field, Type)>> {
 394         let krate = self.resolver.krate()?;
 395         let body = self.body.as_ref()?;
 396         let infer = self.infer.as_ref()?;
 397
 398         let pat_id = self.pat_id(&pattern.clone().into())?;
 399         let substs = infer.type_of_pat[pat_id].as_adt()?.1;
 400
 401         let (variant, missing_fields, _exhaustive) =
 402             record_pattern_missing_fields(db, infer, pat_id, &body[pat_id])?;
 403         let res = self.missing_fields(db, krate, substs, variant, missing_fields);
 404         Some(res)
 405     }
 406
 407     fn missing_fields(
 408         &self,
 409         db: &dyn HirDatabase,
 410         krate: CrateId,
 411         substs: &Substitution,
 412         variant: VariantId,
 413         missing_fields: Vec<LocalFieldId>,
 414     ) -> Vec<(Field, Type)> {
 415         let field_types = db.field_types(variant);
 416
 417         missing_fields
 418             .into_iter()
 419             .map(|local_id| {
 420                 let field = FieldId { parent: variant, local_id };
 421                 let ty = field_types[local_id].clone().substitute(&Interner, substs);
 422                 (field.into(), Type::new_with_resolver_inner(db, krate, &self.resolver, ty))
 423             })
 424             .collect()
 425     }
 426
 427     pub(crate) fn expand(
 428         &self,
 429         db: &dyn HirDatabase,
 430         macro_call: InFile<&ast::MacroCall>,
 431     ) -> Option<HirFileId> {
 432         let krate = self.resolver.krate()?;
 433         let macro_call_id = macro_call.as_call_id(db.upcast(), krate, |path| {
 434             self.resolver.resolve_path_as_macro(db.upcast(), &path)
 435         })?;
 436         Some(macro_call_id.as_file()).filter(|it| it.expansion_level(db.upcast()) < 64)
 437     }
 438
 439     pub(crate) fn resolve_variant(
 440         &self,
 441         db: &dyn HirDatabase,
 442         record_lit: ast::RecordExpr,
 443     ) -> Option<VariantId> {
 444         let infer = self.infer.as_ref()?;
 445         let expr_id = self.expr_id(db, &record_lit.into())?;
 446         infer.variant_resolution_for_expr(expr_id)
 447     }
 448 }
 449
 450 fn scope_for(
 451     scopes: &ExprScopes,
 452     source_map: &BodySourceMap,
 453     node: InFile<&SyntaxNode>,
 454 ) -> Option<ScopeId> {
 455     node.value
 456         .ancestors()
 457         .filter_map(ast::Expr::cast)
 458         .filter_map(|it| source_map.node_expr(InFile::new(node.file_id, &it)))
 459         .find_map(|it| scopes.scope_for(it))
 460 }
 461
 462 fn scope_for_offset(
 463     db: &dyn HirDatabase,
 464     scopes: &ExprScopes,
 465     source_map: &BodySourceMap,
 466     offset: InFile<TextSize>,
 467 ) -> Option<ScopeId> {
 468     scopes
 469         .scope_by_expr()
 470         .iter()
 471         .filter_map(|(id, scope)| {
 472             let source = source_map.expr_syntax(*id).ok()?;
 473             // FIXME: correctly handle macro expansion
 474             if source.file_id != offset.file_id {
 475                 return None;
 476             }
 477             let root = source.file_syntax(db.upcast());
 478             let node = source.value.to_node(&root);
 479             Some((node.syntax().text_range(), scope))
 480         })
 481         // find containing scope
 482         .min_by_key(|(expr_range, _scope)| {
 483             (
 484                 !(expr_range.start() <= offset.value && offset.value <= expr_range.end()),
 485                 expr_range.len(),
 486             )
 487         })
 488         .map(|(expr_range, scope)| {
 489             adjust(db, scopes, source_map, expr_range, offset).unwrap_or(*scope)
 490         })
 491 }
 492
 493 // XXX: during completion, cursor might be outside of any particular
 494 // expression. Try to figure out the correct scope...
 495 fn adjust(
 496     db: &dyn HirDatabase,
 497     scopes: &ExprScopes,
 498     source_map: &BodySourceMap,
 499     expr_range: TextRange,
 500     offset: InFile<TextSize>,
 501 ) -> Option<ScopeId> {
 502     let child_scopes = scopes
 503         .scope_by_expr()
 504         .iter()
 505         .filter_map(|(id, scope)| {
 506             let source = source_map.expr_syntax(*id).ok()?;
 507             // FIXME: correctly handle macro expansion
 508             if source.file_id != offset.file_id {
 509                 return None;
 510             }
 511             let root = source.file_syntax(db.upcast());
 512             let node = source.value.to_node(&root);
 513             Some((node.syntax().text_range(), scope))
 514         })
 515         .filter(|&(range, _)| {
 516             range.start() <= offset.value && expr_range.contains_range(range) && range != expr_range
 517         });
 518
 519     child_scopes
 520         .max_by(|&(r1, _), &(r2, _)| {
 521             if r1.contains_range(r2) {
 522                 std::cmp::Ordering::Greater
 523             } else if r2.contains_range(r1) {
 524                 std::cmp::Ordering::Less
 525             } else {
 526                 r1.start().cmp(&r2.start())
 527             }
 528         })
 529         .map(|(_ptr, scope)| *scope)
 530 }
 531
 532 #[inline]
 533 pub(crate) fn resolve_hir_path(
 534     db: &dyn HirDatabase,
 535     resolver: &Resolver,
 536     path: &Path,
 537 ) -> Option<PathResolution> {
 538     resolve_hir_path_(db, resolver, path, false)
 539 }
 540
 541 #[inline]
 542 pub(crate) fn resolve_hir_path_as_macro(
 543     db: &dyn HirDatabase,
 544     resolver: &Resolver,
 545     path: &Path,
 546 ) -> Option<MacroDef> {
 547     resolver.resolve_path_as_macro(db.upcast(), path.mod_path()).map(Into::into)
 548 }
 549
 550 fn resolve_hir_path_(
 551     db: &dyn HirDatabase,
 552     resolver: &Resolver,
 553     path: &Path,
 554     prefer_value_ns: bool,
 555 ) -> Option<PathResolution> {
 556     let types = || {
 557         let (ty, unresolved) = match path.type_anchor() {
 558             Some(type_ref) => {
 559                 let (_, res) = TyLoweringContext::new(db, resolver).lower_ty_ext(type_ref);
 560                 res.map(|ty_ns| (ty_ns, path.segments().first()))
 561             }
 562             None => {
 563                 let (ty, remaining) =
 564                     resolver.resolve_path_in_type_ns(db.upcast(), path.mod_path())?;
 565                 match remaining {
 566                     Some(remaining) if remaining > 1 => None,
 567                     _ => Some((ty, path.segments().get(1))),
 568                 }
 569             }
 570         }?;
 571
 572         // If we are in a TypeNs for a Trait, and we have an unresolved name, try to resolve it as a type
 573         // within the trait's associated types.
 574         if let (Some(unresolved), &TypeNs::TraitId(trait_id)) = (&unresolved, &ty) {
 575             if let Some(type_alias_id) =
 576                 db.trait_data(trait_id).associated_type_by_name(&unresolved.name)
 577             {
 578                 return Some(PathResolution::Def(ModuleDefId::from(type_alias_id).into()));
 579             }
 580         }
 581
 582         let res = match ty {
 583             TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
 584             TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
 585             TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
 586                 PathResolution::Def(Adt::from(it).into())
 587             }
 588             TypeNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
 589             TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
 590             TypeNs::BuiltinType(it) => PathResolution::Def(BuiltinType::from(it).into()),
 591             TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
 592         };
 593         match unresolved {
 594             Some(unresolved) => res
 595                 .assoc_type_shorthand_candidates(db, |name, alias| {
 596                     (name == unresolved.name).then(|| alias)
 597                 })
 598                 .map(TypeAlias::from)
 599                 .map(Into::into)
 600                 .map(PathResolution::Def),
 601             None => Some(res),
 602         }
 603     };
 604
 605     let body_owner = resolver.body_owner();
 606     let values = || {
 607         resolver.resolve_path_in_value_ns_fully(db.upcast(), path.mod_path()).and_then(|val| {
 608             let res = match val {
 609                 ValueNs::LocalBinding(pat_id) => {
 610                     let var = Local { parent: body_owner?, pat_id };
 611                     PathResolution::Local(var)
 612                 }
 613                 ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
 614                 ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
 615                 ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
 616                 ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
 617                 ValueNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
 618                 ValueNs::ImplSelf(impl_id) => PathResolution::SelfType(impl_id.into()),
 619                 ValueNs::GenericParam(it) => PathResolution::ConstParam(it.into()),
 620             };
 621             Some(res)
 622         })
 623     };
 624
 625     let items = || {
 626         resolver
 627             .resolve_module_path_in_items(db.upcast(), path.mod_path())
 628             .take_types()
 629             .map(|it| PathResolution::Def(it.into()))
 630     };
 631
 632     let macros = || {
 633         resolver
 634             .resolve_path_as_macro(db.upcast(), path.mod_path())
 635             .map(|def| PathResolution::Macro(def.into()))
 636     };
 637
 638     if prefer_value_ns { values().or_else(types) } else { types().or_else(values) }
 639         .or_else(items)
 640         .or_else(macros)
 641 }
 642
 643 /// Resolves a path where we know it is a qualifier of another path.
 644 ///
 645 /// For example, if we have:
 646 /// ```
 647 /// mod my {
 648 ///     pub mod foo {
 649 ///         struct Bar;
 650 ///     }
 651 ///
 652 ///     pub fn foo() {}
 653 /// }
 654 /// ```
 655 /// then we know that `foo` in `my::foo::Bar` refers to the module, not the function.
 656 fn resolve_hir_path_qualifier(
 657     db: &dyn HirDatabase,
 658     resolver: &Resolver,
 659     path: &Path,
 660 ) -> Option<PathResolution> {
 661     let items = resolver
 662         .resolve_module_path_in_items(db.upcast(), path.mod_path())
 663         .take_types()
 664         .map(|it| PathResolution::Def(it.into()));
 665
 666     if items.is_some() {
 667         return items;
 668     }
 669
 670     resolver.resolve_path_in_type_ns_fully(db.upcast(), path.mod_path()).map(|ty| match ty {
 671         TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
 672         TypeNs::GenericParam(id) => PathResolution::TypeParam(TypeParam { id }),
 673         TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => PathResolution::Def(Adt::from(it).into()),
 674         TypeNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
 675         TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
 676         TypeNs::BuiltinType(it) => PathResolution::Def(BuiltinType::from(it).into()),
 677         TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
 678     })
 679 }