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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::{self, once};
9 
10 use either::Either;
11 use hir_def::{
12     body::{
13         scope::{ExprScopes, ScopeId},
14         Body, BodySourceMap,
15     },
16     hir::{BindingId, ExprId, Pat, PatId},
17     lang_item::LangItem,
18     lower::LowerCtx,
19     macro_id_to_def_id,
20     nameres::MacroSubNs,
21     path::{ModPath, Path, PathKind},
22     resolver::{resolver_for_scope, Resolver, TypeNs, ValueNs},
23     type_ref::Mutability,
24     AsMacroCall, AssocItemId, ConstId, DefWithBodyId, FieldId, FunctionId, ItemContainerId,
25     LocalFieldId, Lookup, ModuleDefId, TraitId, VariantId,
26 };
27 use hir_expand::{
28     builtin_fn_macro::BuiltinFnLikeExpander,
29     hygiene::Hygiene,
30     mod_path::path,
31     name,
32     name::{AsName, Name},
33     HirFileId, InFile,
34 };
35 use hir_ty::{
36     diagnostics::{
37         record_literal_missing_fields, record_pattern_missing_fields, unsafe_expressions,
38         UnsafeExpr,
39     },
40     lang_items::lang_items_for_bin_op,
41     method_resolution, Adjustment, InferenceResult, Interner, Substitution, Ty, TyExt, TyKind,
42     TyLoweringContext,
43 };
44 use itertools::Itertools;
45 use smallvec::SmallVec;
46 use syntax::{
47     ast::{self, AstNode},
48     SyntaxKind, SyntaxNode, TextRange, TextSize,
49 };
50 use triomphe::Arc;
51 
52 use crate::{
53     db::HirDatabase, semantics::PathResolution, Adt, AssocItem, BindingMode, BuiltinAttr,
54     BuiltinType, Callable, Const, DeriveHelper, Field, Function, Local, Macro, ModuleDef, Static,
55     Struct, ToolModule, Trait, TraitAlias, Type, TypeAlias, Variant,
56 };
57 
58 /// `SourceAnalyzer` is a convenience wrapper which exposes HIR API in terms of
59 /// original source files. It should not be used inside the HIR itself.
60 #[derive(Debug)]
61 pub(crate) struct SourceAnalyzer {
62     pub(crate) file_id: HirFileId,
63     pub(crate) resolver: Resolver,
64     def: Option<(DefWithBodyId, Arc<Body>, Arc<BodySourceMap>)>,
65     infer: Option<Arc<InferenceResult>>,
66 }
67 
68 impl SourceAnalyzer {
69     pub(crate) fn new_for_body(
70         db: &dyn HirDatabase,
71         def: DefWithBodyId,
72         node @ InFile { file_id, .. }: InFile<&SyntaxNode>,
73         offset: Option<TextSize>,
74     ) -> SourceAnalyzer {
75         let (body, source_map) = db.body_with_source_map(def);
76         let scopes = db.expr_scopes(def);
77         let scope = match offset {
78             None => scope_for(&scopes, &source_map, node),
79             Some(offset) => scope_for_offset(db, &scopes, &source_map, node.file_id, offset),
80         };
81         let resolver = resolver_for_scope(db.upcast(), def, scope);
82         SourceAnalyzer {
83             resolver,
84             def: Some((def, body, source_map)),
85             infer: Some(db.infer(def)),
86             file_id,
87         }
88     }
89 
90     pub(crate) fn new_for_body_no_infer(
91         db: &dyn HirDatabase,
92         def: DefWithBodyId,
93         node @ InFile { file_id, .. }: InFile<&SyntaxNode>,
94         offset: Option<TextSize>,
95     ) -> SourceAnalyzer {
96         let (body, source_map) = db.body_with_source_map(def);
97         let scopes = db.expr_scopes(def);
98         let scope = match offset {
99             None => scope_for(&scopes, &source_map, node),
100             Some(offset) => scope_for_offset(db, &scopes, &source_map, node.file_id, offset),
101         };
102         let resolver = resolver_for_scope(db.upcast(), def, scope);
103         SourceAnalyzer { resolver, def: Some((def, body, source_map)), infer: None, file_id }
104     }
105 
new_for_resolver( resolver: Resolver, node: InFile<&SyntaxNode>, ) -> SourceAnalyzer106     pub(crate) fn new_for_resolver(
107         resolver: Resolver,
108         node: InFile<&SyntaxNode>,
109     ) -> SourceAnalyzer {
110         SourceAnalyzer { resolver, def: None, infer: None, file_id: node.file_id }
111     }
112 
body_source_map(&self) -> Option<&BodySourceMap>113     fn body_source_map(&self) -> Option<&BodySourceMap> {
114         self.def.as_ref().map(|(.., source_map)| &**source_map)
115     }
body(&self) -> Option<&Body>116     fn body(&self) -> Option<&Body> {
117         self.def.as_ref().map(|(_, body, _)| &**body)
118     }
119 
expr_id(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<ExprId>120     fn expr_id(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<ExprId> {
121         let src = match expr {
122             ast::Expr::MacroExpr(expr) => {
123                 self.expand_expr(db, InFile::new(self.file_id, expr.macro_call()?))?
124             }
125             _ => InFile::new(self.file_id, expr.clone()),
126         };
127         let sm = self.body_source_map()?;
128         sm.node_expr(src.as_ref())
129     }
130 
pat_id(&self, pat: &ast::Pat) -> Option<PatId>131     fn pat_id(&self, pat: &ast::Pat) -> Option<PatId> {
132         // FIXME: macros, see `expr_id`
133         let src = InFile { file_id: self.file_id, value: pat };
134         self.body_source_map()?.node_pat(src)
135     }
136 
binding_id_of_pat(&self, pat: &ast::IdentPat) -> Option<BindingId>137     fn binding_id_of_pat(&self, pat: &ast::IdentPat) -> Option<BindingId> {
138         let pat_id = self.pat_id(&pat.clone().into())?;
139         if let Pat::Bind { id, .. } = self.body()?.pats[pat_id] {
140             Some(id)
141         } else {
142             None
143         }
144     }
145 
expand_expr( &self, db: &dyn HirDatabase, expr: InFile<ast::MacroCall>, ) -> Option<InFile<ast::Expr>>146     fn expand_expr(
147         &self,
148         db: &dyn HirDatabase,
149         expr: InFile<ast::MacroCall>,
150     ) -> Option<InFile<ast::Expr>> {
151         let macro_file = self.body_source_map()?.node_macro_file(expr.as_ref())?;
152         let expanded = db.parse_or_expand(macro_file);
153         let res = if let Some(stmts) = ast::MacroStmts::cast(expanded.clone()) {
154             match stmts.expr()? {
155                 ast::Expr::MacroExpr(mac) => {
156                     self.expand_expr(db, InFile::new(macro_file, mac.macro_call()?))?
157                 }
158                 expr => InFile::new(macro_file, expr),
159             }
160         } else if let Some(call) = ast::MacroCall::cast(expanded.clone()) {
161             self.expand_expr(db, InFile::new(macro_file, call))?
162         } else {
163             InFile::new(macro_file, ast::Expr::cast(expanded)?)
164         };
165 
166         Some(res)
167     }
168 
expr_adjustments( &self, db: &dyn HirDatabase, expr: &ast::Expr, ) -> Option<&[Adjustment]>169     pub(crate) fn expr_adjustments(
170         &self,
171         db: &dyn HirDatabase,
172         expr: &ast::Expr,
173     ) -> Option<&[Adjustment]> {
174         let expr_id = self.expr_id(db, expr)?;
175         let infer = self.infer.as_ref()?;
176         infer.expr_adjustments.get(&expr_id).map(|v| &**v)
177     }
178 
type_of_expr( &self, db: &dyn HirDatabase, expr: &ast::Expr, ) -> Option<(Type, Option<Type>)>179     pub(crate) fn type_of_expr(
180         &self,
181         db: &dyn HirDatabase,
182         expr: &ast::Expr,
183     ) -> Option<(Type, Option<Type>)> {
184         let expr_id = self.expr_id(db, expr)?;
185         let infer = self.infer.as_ref()?;
186         let coerced = infer
187             .expr_adjustments
188             .get(&expr_id)
189             .and_then(|adjusts| adjusts.last().map(|adjust| adjust.target.clone()));
190         let ty = infer[expr_id].clone();
191         let mk_ty = |ty| Type::new_with_resolver(db, &self.resolver, ty);
192         Some((mk_ty(ty), coerced.map(mk_ty)))
193     }
194 
type_of_pat( &self, db: &dyn HirDatabase, pat: &ast::Pat, ) -> Option<(Type, Option<Type>)>195     pub(crate) fn type_of_pat(
196         &self,
197         db: &dyn HirDatabase,
198         pat: &ast::Pat,
199     ) -> Option<(Type, Option<Type>)> {
200         let pat_id = self.pat_id(pat)?;
201         let infer = self.infer.as_ref()?;
202         let coerced = infer
203             .pat_adjustments
204             .get(&pat_id)
205             .and_then(|adjusts| adjusts.last().map(|adjust| adjust.clone()));
206         let ty = infer[pat_id].clone();
207         let mk_ty = |ty| Type::new_with_resolver(db, &self.resolver, ty);
208         Some((mk_ty(ty), coerced.map(mk_ty)))
209     }
210 
type_of_binding_in_pat( &self, db: &dyn HirDatabase, pat: &ast::IdentPat, ) -> Option<Type>211     pub(crate) fn type_of_binding_in_pat(
212         &self,
213         db: &dyn HirDatabase,
214         pat: &ast::IdentPat,
215     ) -> Option<Type> {
216         let binding_id = self.binding_id_of_pat(pat)?;
217         let infer = self.infer.as_ref()?;
218         let ty = infer[binding_id].clone();
219         let mk_ty = |ty| Type::new_with_resolver(db, &self.resolver, ty);
220         Some(mk_ty(ty))
221     }
222 
type_of_self( &self, db: &dyn HirDatabase, param: &ast::SelfParam, ) -> Option<Type>223     pub(crate) fn type_of_self(
224         &self,
225         db: &dyn HirDatabase,
226         param: &ast::SelfParam,
227     ) -> Option<Type> {
228         let src = InFile { file_id: self.file_id, value: param };
229         let pat_id = self.body_source_map()?.node_self_param(src)?;
230         let ty = self.infer.as_ref()?[pat_id].clone();
231         Some(Type::new_with_resolver(db, &self.resolver, ty))
232     }
233 
binding_mode_of_pat( &self, _db: &dyn HirDatabase, pat: &ast::IdentPat, ) -> Option<BindingMode>234     pub(crate) fn binding_mode_of_pat(
235         &self,
236         _db: &dyn HirDatabase,
237         pat: &ast::IdentPat,
238     ) -> Option<BindingMode> {
239         let binding_id = self.binding_id_of_pat(pat)?;
240         let infer = self.infer.as_ref()?;
241         infer.binding_modes.get(binding_id).map(|bm| match bm {
242             hir_ty::BindingMode::Move => BindingMode::Move,
243             hir_ty::BindingMode::Ref(hir_ty::Mutability::Mut) => BindingMode::Ref(Mutability::Mut),
244             hir_ty::BindingMode::Ref(hir_ty::Mutability::Not) => {
245                 BindingMode::Ref(Mutability::Shared)
246             }
247         })
248     }
pattern_adjustments( &self, db: &dyn HirDatabase, pat: &ast::Pat, ) -> Option<SmallVec<[Type; 1]>>249     pub(crate) fn pattern_adjustments(
250         &self,
251         db: &dyn HirDatabase,
252         pat: &ast::Pat,
253     ) -> Option<SmallVec<[Type; 1]>> {
254         let pat_id = self.pat_id(pat)?;
255         let infer = self.infer.as_ref()?;
256         Some(
257             infer
258                 .pat_adjustments
259                 .get(&pat_id)?
260                 .iter()
261                 .map(|ty| Type::new_with_resolver(db, &self.resolver, ty.clone()))
262                 .collect(),
263         )
264     }
265 
resolve_method_call_as_callable( &self, db: &dyn HirDatabase, call: &ast::MethodCallExpr, ) -> Option<Callable>266     pub(crate) fn resolve_method_call_as_callable(
267         &self,
268         db: &dyn HirDatabase,
269         call: &ast::MethodCallExpr,
270     ) -> Option<Callable> {
271         let expr_id = self.expr_id(db, &call.clone().into())?;
272         let (func, substs) = self.infer.as_ref()?.method_resolution(expr_id)?;
273         let ty = db.value_ty(func.into()).substitute(Interner, &substs);
274         let ty = Type::new_with_resolver(db, &self.resolver, ty);
275         let mut res = ty.as_callable(db)?;
276         res.is_bound_method = true;
277         Some(res)
278     }
279 
resolve_method_call( &self, db: &dyn HirDatabase, call: &ast::MethodCallExpr, ) -> Option<FunctionId>280     pub(crate) fn resolve_method_call(
281         &self,
282         db: &dyn HirDatabase,
283         call: &ast::MethodCallExpr,
284     ) -> Option<FunctionId> {
285         let expr_id = self.expr_id(db, &call.clone().into())?;
286         let (f_in_trait, substs) = self.infer.as_ref()?.method_resolution(expr_id)?;
287 
288         Some(self.resolve_impl_method_or_trait_def(db, f_in_trait, substs))
289     }
290 
resolve_method_call_fallback( &self, db: &dyn HirDatabase, call: &ast::MethodCallExpr, ) -> Option<Either<FunctionId, FieldId>>291     pub(crate) fn resolve_method_call_fallback(
292         &self,
293         db: &dyn HirDatabase,
294         call: &ast::MethodCallExpr,
295     ) -> Option<Either<FunctionId, FieldId>> {
296         let expr_id = self.expr_id(db, &call.clone().into())?;
297         let inference_result = self.infer.as_ref()?;
298         match inference_result.method_resolution(expr_id) {
299             Some((f_in_trait, substs)) => {
300                 Some(Either::Left(self.resolve_impl_method_or_trait_def(db, f_in_trait, substs)))
301             }
302             None => inference_result.field_resolution(expr_id).map(Either::Right),
303         }
304     }
305 
resolve_await_to_poll( &self, db: &dyn HirDatabase, await_expr: &ast::AwaitExpr, ) -> Option<FunctionId>306     pub(crate) fn resolve_await_to_poll(
307         &self,
308         db: &dyn HirDatabase,
309         await_expr: &ast::AwaitExpr,
310     ) -> Option<FunctionId> {
311         let mut ty = self.ty_of_expr(db, &await_expr.expr()?)?.clone();
312 
313         let into_future_trait = self
314             .resolver
315             .resolve_known_trait(db.upcast(), &path![core::future::IntoFuture])
316             .map(Trait::from);
317 
318         if let Some(into_future_trait) = into_future_trait {
319             let type_ = Type::new_with_resolver(db, &self.resolver, ty.clone());
320             if type_.impls_trait(db, into_future_trait, &[]) {
321                 let items = into_future_trait.items(db);
322                 let into_future_type = items.into_iter().find_map(|item| match item {
323                     AssocItem::TypeAlias(alias)
324                         if alias.name(db) == hir_expand::name![IntoFuture] =>
325                     {
326                         Some(alias)
327                     }
328                     _ => None,
329                 })?;
330                 let future_trait = type_.normalize_trait_assoc_type(db, &[], into_future_type)?;
331                 ty = future_trait.ty;
332             }
333         }
334 
335         let future_trait = db.lang_item(self.resolver.krate(), LangItem::Future)?.as_trait()?;
336         let poll_fn = db.lang_item(self.resolver.krate(), LangItem::FuturePoll)?.as_function()?;
337         // HACK: subst for `poll()` coincides with that for `Future` because `poll()` itself
338         // doesn't have any generic parameters, so we skip building another subst for `poll()`.
339         let substs = hir_ty::TyBuilder::subst_for_def(db, future_trait, None).push(ty).build();
340         Some(self.resolve_impl_method_or_trait_def(db, poll_fn, substs))
341     }
342 
resolve_prefix_expr( &self, db: &dyn HirDatabase, prefix_expr: &ast::PrefixExpr, ) -> Option<FunctionId>343     pub(crate) fn resolve_prefix_expr(
344         &self,
345         db: &dyn HirDatabase,
346         prefix_expr: &ast::PrefixExpr,
347     ) -> Option<FunctionId> {
348         let (lang_item, fn_name) = match prefix_expr.op_kind()? {
349             ast::UnaryOp::Deref => (LangItem::Deref, name![deref]),
350             ast::UnaryOp::Not => (LangItem::Not, name![not]),
351             ast::UnaryOp::Neg => (LangItem::Neg, name![neg]),
352         };
353         let ty = self.ty_of_expr(db, &prefix_expr.expr()?)?;
354 
355         let (op_trait, op_fn) = self.lang_trait_fn(db, lang_item, &fn_name)?;
356         // HACK: subst for all methods coincides with that for their trait because the methods
357         // don't have any generic parameters, so we skip building another subst for the methods.
358         let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None).push(ty.clone()).build();
359 
360         Some(self.resolve_impl_method_or_trait_def(db, op_fn, substs))
361     }
362 
resolve_index_expr( &self, db: &dyn HirDatabase, index_expr: &ast::IndexExpr, ) -> Option<FunctionId>363     pub(crate) fn resolve_index_expr(
364         &self,
365         db: &dyn HirDatabase,
366         index_expr: &ast::IndexExpr,
367     ) -> Option<FunctionId> {
368         let base_ty = self.ty_of_expr(db, &index_expr.base()?)?;
369         let index_ty = self.ty_of_expr(db, &index_expr.index()?)?;
370 
371         let (op_trait, op_fn) = self.lang_trait_fn(db, LangItem::Index, &name![index])?;
372         // HACK: subst for all methods coincides with that for their trait because the methods
373         // don't have any generic parameters, so we skip building another subst for the methods.
374         let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None)
375             .push(base_ty.clone())
376             .push(index_ty.clone())
377             .build();
378         Some(self.resolve_impl_method_or_trait_def(db, op_fn, substs))
379     }
380 
resolve_bin_expr( &self, db: &dyn HirDatabase, binop_expr: &ast::BinExpr, ) -> Option<FunctionId>381     pub(crate) fn resolve_bin_expr(
382         &self,
383         db: &dyn HirDatabase,
384         binop_expr: &ast::BinExpr,
385     ) -> Option<FunctionId> {
386         let op = binop_expr.op_kind()?;
387         let lhs = self.ty_of_expr(db, &binop_expr.lhs()?)?;
388         let rhs = self.ty_of_expr(db, &binop_expr.rhs()?)?;
389 
390         let (op_trait, op_fn) = lang_items_for_bin_op(op)
391             .and_then(|(name, lang_item)| self.lang_trait_fn(db, lang_item, &name))?;
392         // HACK: subst for `index()` coincides with that for `Index` because `index()` itself
393         // doesn't have any generic parameters, so we skip building another subst for `index()`.
394         let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None)
395             .push(lhs.clone())
396             .push(rhs.clone())
397             .build();
398 
399         Some(self.resolve_impl_method_or_trait_def(db, op_fn, substs))
400     }
401 
resolve_try_expr( &self, db: &dyn HirDatabase, try_expr: &ast::TryExpr, ) -> Option<FunctionId>402     pub(crate) fn resolve_try_expr(
403         &self,
404         db: &dyn HirDatabase,
405         try_expr: &ast::TryExpr,
406     ) -> Option<FunctionId> {
407         let ty = self.ty_of_expr(db, &try_expr.expr()?)?;
408 
409         let op_fn = db.lang_item(self.resolver.krate(), LangItem::TryTraitBranch)?.as_function()?;
410         let op_trait = match op_fn.lookup(db.upcast()).container {
411             ItemContainerId::TraitId(id) => id,
412             _ => return None,
413         };
414         // HACK: subst for `branch()` coincides with that for `Try` because `branch()` itself
415         // doesn't have any generic parameters, so we skip building another subst for `branch()`.
416         let substs = hir_ty::TyBuilder::subst_for_def(db, op_trait, None).push(ty.clone()).build();
417 
418         Some(self.resolve_impl_method_or_trait_def(db, op_fn, substs))
419     }
420 
resolve_field( &self, db: &dyn HirDatabase, field: &ast::FieldExpr, ) -> Option<Field>421     pub(crate) fn resolve_field(
422         &self,
423         db: &dyn HirDatabase,
424         field: &ast::FieldExpr,
425     ) -> Option<Field> {
426         let expr_id = self.expr_id(db, &field.clone().into())?;
427         self.infer.as_ref()?.field_resolution(expr_id).map(|it| it.into())
428     }
429 
resolve_record_field( &self, db: &dyn HirDatabase, field: &ast::RecordExprField, ) -> Option<(Field, Option<Local>, Type)>430     pub(crate) fn resolve_record_field(
431         &self,
432         db: &dyn HirDatabase,
433         field: &ast::RecordExprField,
434     ) -> Option<(Field, Option<Local>, Type)> {
435         let record_expr = ast::RecordExpr::cast(field.syntax().parent().and_then(|p| p.parent())?)?;
436         let expr = ast::Expr::from(record_expr);
437         let expr_id = self.body_source_map()?.node_expr(InFile::new(self.file_id, &expr))?;
438 
439         let local_name = field.field_name()?.as_name();
440         let local = if field.name_ref().is_some() {
441             None
442         } else {
443             // Shorthand syntax, resolve to the local
444             let path = Path::from_known_path_with_no_generic(ModPath::from_segments(
445                 PathKind::Plain,
446                 once(local_name.clone()),
447             ));
448             match self.resolver.resolve_path_in_value_ns_fully(db.upcast(), &path) {
449                 Some(ValueNs::LocalBinding(binding_id)) => {
450                     Some(Local { binding_id, parent: self.resolver.body_owner()? })
451                 }
452                 _ => None,
453             }
454         };
455         let (_, subst) = self.infer.as_ref()?.type_of_expr.get(expr_id)?.as_adt()?;
456         let variant = self.infer.as_ref()?.variant_resolution_for_expr(expr_id)?;
457         let variant_data = variant.variant_data(db.upcast());
458         let field = FieldId { parent: variant, local_id: variant_data.field(&local_name)? };
459         let field_ty =
460             db.field_types(variant).get(field.local_id)?.clone().substitute(Interner, subst);
461         Some((field.into(), local, Type::new_with_resolver(db, &self.resolver, field_ty)))
462     }
463 
resolve_record_pat_field( &self, db: &dyn HirDatabase, field: &ast::RecordPatField, ) -> Option<(Field, Type)>464     pub(crate) fn resolve_record_pat_field(
465         &self,
466         db: &dyn HirDatabase,
467         field: &ast::RecordPatField,
468     ) -> Option<(Field, Type)> {
469         let field_name = field.field_name()?.as_name();
470         let record_pat = ast::RecordPat::cast(field.syntax().parent().and_then(|p| p.parent())?)?;
471         let pat_id = self.pat_id(&record_pat.into())?;
472         let variant = self.infer.as_ref()?.variant_resolution_for_pat(pat_id)?;
473         let variant_data = variant.variant_data(db.upcast());
474         let field = FieldId { parent: variant, local_id: variant_data.field(&field_name)? };
475         let (_, subst) = self.infer.as_ref()?.type_of_pat.get(pat_id)?.as_adt()?;
476         let field_ty =
477             db.field_types(variant).get(field.local_id)?.clone().substitute(Interner, subst);
478         Some((field.into(), Type::new_with_resolver(db, &self.resolver, field_ty)))
479     }
480 
resolve_macro_call( &self, db: &dyn HirDatabase, macro_call: InFile<&ast::MacroCall>, ) -> Option<Macro>481     pub(crate) fn resolve_macro_call(
482         &self,
483         db: &dyn HirDatabase,
484         macro_call: InFile<&ast::MacroCall>,
485     ) -> Option<Macro> {
486         let ctx = LowerCtx::with_file_id(db.upcast(), macro_call.file_id);
487         let path = macro_call.value.path().and_then(|ast| Path::from_src(ast, &ctx))?;
488         self.resolver
489             .resolve_path_as_macro(db.upcast(), path.mod_path()?, Some(MacroSubNs::Bang))
490             .map(|it| it.into())
491     }
492 
resolve_bind_pat_to_const( &self, db: &dyn HirDatabase, pat: &ast::IdentPat, ) -> Option<ModuleDef>493     pub(crate) fn resolve_bind_pat_to_const(
494         &self,
495         db: &dyn HirDatabase,
496         pat: &ast::IdentPat,
497     ) -> Option<ModuleDef> {
498         let pat_id = self.pat_id(&pat.clone().into())?;
499         let body = self.body()?;
500         let path = match &body[pat_id] {
501             Pat::Path(path) => path,
502             _ => return None,
503         };
504         let res = resolve_hir_path(db, &self.resolver, path)?;
505         match res {
506             PathResolution::Def(def) => Some(def),
507             _ => None,
508         }
509     }
510 
resolve_path( &self, db: &dyn HirDatabase, path: &ast::Path, ) -> Option<PathResolution>511     pub(crate) fn resolve_path(
512         &self,
513         db: &dyn HirDatabase,
514         path: &ast::Path,
515     ) -> Option<PathResolution> {
516         let parent = path.syntax().parent();
517         let parent = || parent.clone();
518 
519         let mut prefer_value_ns = false;
520         let resolved = (|| {
521             let infer = self.infer.as_deref()?;
522             if let Some(path_expr) = parent().and_then(ast::PathExpr::cast) {
523                 let expr_id = self.expr_id(db, &path_expr.into())?;
524                 if let Some((assoc, subs)) = infer.assoc_resolutions_for_expr(expr_id) {
525                     let assoc = match assoc {
526                         AssocItemId::FunctionId(f_in_trait) => {
527                             match infer.type_of_expr.get(expr_id) {
528                                 None => assoc,
529                                 Some(func_ty) => {
530                                     if let TyKind::FnDef(_fn_def, subs) = func_ty.kind(Interner) {
531                                         self.resolve_impl_method_or_trait_def(
532                                             db,
533                                             f_in_trait,
534                                             subs.clone(),
535                                         )
536                                         .into()
537                                     } else {
538                                         assoc
539                                     }
540                                 }
541                             }
542                         }
543                         AssocItemId::ConstId(const_id) => {
544                             self.resolve_impl_const_or_trait_def(db, const_id, subs).into()
545                         }
546                         assoc => assoc,
547                     };
548 
549                     return Some(PathResolution::Def(AssocItem::from(assoc).into()));
550                 }
551                 if let Some(VariantId::EnumVariantId(variant)) =
552                     infer.variant_resolution_for_expr(expr_id)
553                 {
554                     return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
555                 }
556                 prefer_value_ns = true;
557             } else if let Some(path_pat) = parent().and_then(ast::PathPat::cast) {
558                 let pat_id = self.pat_id(&path_pat.into())?;
559                 if let Some((assoc, subs)) = infer.assoc_resolutions_for_pat(pat_id) {
560                     let assoc = match assoc {
561                         AssocItemId::ConstId(const_id) => {
562                             self.resolve_impl_const_or_trait_def(db, const_id, subs).into()
563                         }
564                         assoc => assoc,
565                     };
566                     return Some(PathResolution::Def(AssocItem::from(assoc).into()));
567                 }
568                 if let Some(VariantId::EnumVariantId(variant)) =
569                     infer.variant_resolution_for_pat(pat_id)
570                 {
571                     return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
572                 }
573             } else if let Some(rec_lit) = parent().and_then(ast::RecordExpr::cast) {
574                 let expr_id = self.expr_id(db, &rec_lit.into())?;
575                 if let Some(VariantId::EnumVariantId(variant)) =
576                     infer.variant_resolution_for_expr(expr_id)
577                 {
578                     return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
579                 }
580             } else {
581                 let record_pat = parent().and_then(ast::RecordPat::cast).map(ast::Pat::from);
582                 let tuple_struct_pat =
583                     || parent().and_then(ast::TupleStructPat::cast).map(ast::Pat::from);
584                 if let Some(pat) = record_pat.or_else(tuple_struct_pat) {
585                     let pat_id = self.pat_id(&pat)?;
586                     let variant_res_for_pat = infer.variant_resolution_for_pat(pat_id);
587                     if let Some(VariantId::EnumVariantId(variant)) = variant_res_for_pat {
588                         return Some(PathResolution::Def(ModuleDef::Variant(variant.into())));
589                     }
590                 }
591             }
592             None
593         })();
594         if let Some(_) = resolved {
595             return resolved;
596         }
597 
598         // This must be a normal source file rather than macro file.
599         let hygiene = Hygiene::new(db.upcast(), self.file_id);
600         let ctx = LowerCtx::with_hygiene(db.upcast(), &hygiene);
601         let hir_path = Path::from_src(path.clone(), &ctx)?;
602 
603         // Case where path is a qualifier of a use tree, e.g. foo::bar::{Baz, Qux} where we are
604         // trying to resolve foo::bar.
605         if let Some(use_tree) = parent().and_then(ast::UseTree::cast) {
606             if use_tree.coloncolon_token().is_some() {
607                 return resolve_hir_path_qualifier(db, &self.resolver, &hir_path);
608             }
609         }
610 
611         let meta_path = path
612             .syntax()
613             .ancestors()
614             .take_while(|it| {
615                 let kind = it.kind();
616                 ast::Path::can_cast(kind) || ast::Meta::can_cast(kind)
617             })
618             .last()
619             .and_then(ast::Meta::cast);
620 
621         // Case where path is a qualifier of another path, e.g. foo::bar::Baz where we are
622         // trying to resolve foo::bar.
623         if path.parent_path().is_some() {
624             return match resolve_hir_path_qualifier(db, &self.resolver, &hir_path) {
625                 None if meta_path.is_some() => {
626                     path.first_segment().and_then(|it| it.name_ref()).and_then(|name_ref| {
627                         ToolModule::by_name(db, self.resolver.krate().into(), &name_ref.text())
628                             .map(PathResolution::ToolModule)
629                     })
630                 }
631                 res => res,
632             };
633         } else if let Some(meta_path) = meta_path {
634             // Case where we are resolving the final path segment of a path in an attribute
635             // in this case we have to check for inert/builtin attributes and tools and prioritize
636             // resolution of attributes over other namespaces
637             if let Some(name_ref) = path.as_single_name_ref() {
638                 let builtin =
639                     BuiltinAttr::by_name(db, self.resolver.krate().into(), &name_ref.text());
640                 if let Some(_) = builtin {
641                     return builtin.map(PathResolution::BuiltinAttr);
642                 }
643 
644                 if let Some(attr) = meta_path.parent_attr() {
645                     let adt = if let Some(field) =
646                         attr.syntax().parent().and_then(ast::RecordField::cast)
647                     {
648                         field.syntax().ancestors().take(4).find_map(ast::Adt::cast)
649                     } else if let Some(field) =
650                         attr.syntax().parent().and_then(ast::TupleField::cast)
651                     {
652                         field.syntax().ancestors().take(4).find_map(ast::Adt::cast)
653                     } else if let Some(variant) =
654                         attr.syntax().parent().and_then(ast::Variant::cast)
655                     {
656                         variant.syntax().ancestors().nth(2).and_then(ast::Adt::cast)
657                     } else {
658                         None
659                     };
660                     if let Some(adt) = adt {
661                         let ast_id = db.ast_id_map(self.file_id).ast_id(&adt);
662                         if let Some(helpers) = self
663                             .resolver
664                             .def_map()
665                             .derive_helpers_in_scope(InFile::new(self.file_id, ast_id))
666                         {
667                             // FIXME: Multiple derives can have the same helper
668                             let name_ref = name_ref.as_name();
669                             for (macro_id, mut helpers) in
670                                 helpers.iter().group_by(|(_, macro_id, ..)| macro_id).into_iter()
671                             {
672                                 if let Some(idx) = helpers.position(|(name, ..)| *name == name_ref)
673                                 {
674                                     return Some(PathResolution::DeriveHelper(DeriveHelper {
675                                         derive: *macro_id,
676                                         idx: idx as u32,
677                                     }));
678                                 }
679                             }
680                         }
681                     }
682                 }
683             }
684             return match resolve_hir_path_as_attr_macro(db, &self.resolver, &hir_path) {
685                 Some(m) => Some(PathResolution::Def(ModuleDef::Macro(m))),
686                 // this labels any path that starts with a tool module as the tool itself, this is technically wrong
687                 // but there is no benefit in differentiating these two cases for the time being
688                 None => path.first_segment().and_then(|it| it.name_ref()).and_then(|name_ref| {
689                     ToolModule::by_name(db, self.resolver.krate().into(), &name_ref.text())
690                         .map(PathResolution::ToolModule)
691                 }),
692             };
693         }
694         if parent().map_or(false, |it| ast::Visibility::can_cast(it.kind())) {
695             resolve_hir_path_qualifier(db, &self.resolver, &hir_path)
696         } else {
697             resolve_hir_path_(db, &self.resolver, &hir_path, prefer_value_ns)
698         }
699     }
700 
record_literal_missing_fields( &self, db: &dyn HirDatabase, literal: &ast::RecordExpr, ) -> Option<Vec<(Field, Type)>>701     pub(crate) fn record_literal_missing_fields(
702         &self,
703         db: &dyn HirDatabase,
704         literal: &ast::RecordExpr,
705     ) -> Option<Vec<(Field, Type)>> {
706         let body = self.body()?;
707         let infer = self.infer.as_ref()?;
708 
709         let expr_id = self.expr_id(db, &literal.clone().into())?;
710         let substs = infer.type_of_expr[expr_id].as_adt()?.1;
711 
712         let (variant, missing_fields, _exhaustive) =
713             record_literal_missing_fields(db, infer, expr_id, &body[expr_id])?;
714         let res = self.missing_fields(db, substs, variant, missing_fields);
715         Some(res)
716     }
717 
record_pattern_missing_fields( &self, db: &dyn HirDatabase, pattern: &ast::RecordPat, ) -> Option<Vec<(Field, Type)>>718     pub(crate) fn record_pattern_missing_fields(
719         &self,
720         db: &dyn HirDatabase,
721         pattern: &ast::RecordPat,
722     ) -> Option<Vec<(Field, Type)>> {
723         let body = self.body()?;
724         let infer = self.infer.as_ref()?;
725 
726         let pat_id = self.pat_id(&pattern.clone().into())?;
727         let substs = infer.type_of_pat[pat_id].as_adt()?.1;
728 
729         let (variant, missing_fields, _exhaustive) =
730             record_pattern_missing_fields(db, infer, pat_id, &body[pat_id])?;
731         let res = self.missing_fields(db, substs, variant, missing_fields);
732         Some(res)
733     }
734 
missing_fields( &self, db: &dyn HirDatabase, substs: &Substitution, variant: VariantId, missing_fields: Vec<LocalFieldId>, ) -> Vec<(Field, Type)>735     fn missing_fields(
736         &self,
737         db: &dyn HirDatabase,
738         substs: &Substitution,
739         variant: VariantId,
740         missing_fields: Vec<LocalFieldId>,
741     ) -> Vec<(Field, Type)> {
742         let field_types = db.field_types(variant);
743 
744         missing_fields
745             .into_iter()
746             .map(|local_id| {
747                 let field = FieldId { parent: variant, local_id };
748                 let ty = field_types[local_id].clone().substitute(Interner, substs);
749                 (field.into(), Type::new_with_resolver_inner(db, &self.resolver, ty))
750             })
751             .collect()
752     }
753 
expand( &self, db: &dyn HirDatabase, macro_call: InFile<&ast::MacroCall>, ) -> Option<HirFileId>754     pub(crate) fn expand(
755         &self,
756         db: &dyn HirDatabase,
757         macro_call: InFile<&ast::MacroCall>,
758     ) -> Option<HirFileId> {
759         let krate = self.resolver.krate();
760         let macro_call_id = macro_call.as_call_id(db.upcast(), krate, |path| {
761             self.resolver
762                 .resolve_path_as_macro(db.upcast(), &path, Some(MacroSubNs::Bang))
763                 .map(|it| macro_id_to_def_id(db.upcast(), it))
764         })?;
765         Some(macro_call_id.as_file()).filter(|it| it.expansion_level(db.upcast()) < 64)
766     }
767 
resolve_variant( &self, db: &dyn HirDatabase, record_lit: ast::RecordExpr, ) -> Option<VariantId>768     pub(crate) fn resolve_variant(
769         &self,
770         db: &dyn HirDatabase,
771         record_lit: ast::RecordExpr,
772     ) -> Option<VariantId> {
773         let infer = self.infer.as_ref()?;
774         let expr_id = self.expr_id(db, &record_lit.into())?;
775         infer.variant_resolution_for_expr(expr_id)
776     }
777 
is_unsafe_macro_call( &self, db: &dyn HirDatabase, macro_call: InFile<&ast::MacroCall>, ) -> bool778     pub(crate) fn is_unsafe_macro_call(
779         &self,
780         db: &dyn HirDatabase,
781         macro_call: InFile<&ast::MacroCall>,
782     ) -> bool {
783         // check for asm/global_asm
784         if let Some(mac) = self.resolve_macro_call(db, macro_call) {
785             let ex = match mac.id {
786                 hir_def::MacroId::Macro2Id(it) => it.lookup(db.upcast()).expander,
787                 hir_def::MacroId::MacroRulesId(it) => it.lookup(db.upcast()).expander,
788                 _ => hir_def::MacroExpander::Declarative,
789             };
790             match ex {
791                 hir_def::MacroExpander::BuiltIn(e)
792                     if e == BuiltinFnLikeExpander::Asm || e == BuiltinFnLikeExpander::GlobalAsm =>
793                 {
794                     return true
795                 }
796                 _ => (),
797             }
798         }
799         let macro_expr = match macro_call
800             .map(|it| it.syntax().parent().and_then(ast::MacroExpr::cast))
801             .transpose()
802         {
803             Some(it) => it,
804             None => return false,
805         };
806 
807         if let (Some((def, body, sm)), Some(infer)) = (&self.def, &self.infer) {
808             if let Some(expanded_expr) = sm.macro_expansion_expr(macro_expr.as_ref()) {
809                 let mut is_unsafe = false;
810                 unsafe_expressions(
811                     db,
812                     infer,
813                     *def,
814                     body,
815                     expanded_expr,
816                     &mut |UnsafeExpr { inside_unsafe_block, .. }| is_unsafe |= !inside_unsafe_block,
817                 );
818                 return is_unsafe;
819             }
820         }
821         false
822     }
823 
resolve_impl_method_or_trait_def( &self, db: &dyn HirDatabase, func: FunctionId, substs: Substitution, ) -> FunctionId824     fn resolve_impl_method_or_trait_def(
825         &self,
826         db: &dyn HirDatabase,
827         func: FunctionId,
828         substs: Substitution,
829     ) -> FunctionId {
830         let owner = match self.resolver.body_owner() {
831             Some(it) => it,
832             None => return func,
833         };
834         let env = db.trait_environment_for_body(owner);
835         method_resolution::lookup_impl_method(db, env, func, substs).0
836     }
837 
resolve_impl_const_or_trait_def( &self, db: &dyn HirDatabase, const_id: ConstId, subs: Substitution, ) -> ConstId838     fn resolve_impl_const_or_trait_def(
839         &self,
840         db: &dyn HirDatabase,
841         const_id: ConstId,
842         subs: Substitution,
843     ) -> ConstId {
844         let owner = match self.resolver.body_owner() {
845             Some(it) => it,
846             None => return const_id,
847         };
848         let env = db.trait_environment_for_body(owner);
849         method_resolution::lookup_impl_const(db, env, const_id, subs).0
850     }
851 
lang_trait_fn( &self, db: &dyn HirDatabase, lang_trait: LangItem, method_name: &Name, ) -> Option<(TraitId, FunctionId)>852     fn lang_trait_fn(
853         &self,
854         db: &dyn HirDatabase,
855         lang_trait: LangItem,
856         method_name: &Name,
857     ) -> Option<(TraitId, FunctionId)> {
858         let trait_id = db.lang_item(self.resolver.krate(), lang_trait)?.as_trait()?;
859         let fn_id = db.trait_data(trait_id).method_by_name(method_name)?;
860         Some((trait_id, fn_id))
861     }
862 
ty_of_expr(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<&Ty>863     fn ty_of_expr(&self, db: &dyn HirDatabase, expr: &ast::Expr) -> Option<&Ty> {
864         self.infer.as_ref()?.type_of_expr.get(self.expr_id(db, expr)?)
865     }
866 }
867 
scope_for( scopes: &ExprScopes, source_map: &BodySourceMap, node: InFile<&SyntaxNode>, ) -> Option<ScopeId>868 fn scope_for(
869     scopes: &ExprScopes,
870     source_map: &BodySourceMap,
871     node: InFile<&SyntaxNode>,
872 ) -> Option<ScopeId> {
873     node.value
874         .ancestors()
875         .filter_map(ast::Expr::cast)
876         .filter_map(|it| source_map.node_expr(InFile::new(node.file_id, &it)))
877         .find_map(|it| scopes.scope_for(it))
878 }
879 
scope_for_offset( db: &dyn HirDatabase, scopes: &ExprScopes, source_map: &BodySourceMap, from_file: HirFileId, offset: TextSize, ) -> Option<ScopeId>880 fn scope_for_offset(
881     db: &dyn HirDatabase,
882     scopes: &ExprScopes,
883     source_map: &BodySourceMap,
884     from_file: HirFileId,
885     offset: TextSize,
886 ) -> Option<ScopeId> {
887     scopes
888         .scope_by_expr()
889         .iter()
890         .filter_map(|(id, scope)| {
891             let InFile { file_id, value } = source_map.expr_syntax(*id).ok()?;
892             if from_file == file_id {
893                 return Some((value.text_range(), scope));
894             }
895 
896             // FIXME handle attribute expansion
897             let source = iter::successors(file_id.call_node(db.upcast()), |it| {
898                 it.file_id.call_node(db.upcast())
899             })
900             .find(|it| it.file_id == from_file)
901             .filter(|it| it.value.kind() == SyntaxKind::MACRO_CALL)?;
902             Some((source.value.text_range(), scope))
903         })
904         .filter(|(expr_range, _scope)| expr_range.start() <= offset && offset <= expr_range.end())
905         // find containing scope
906         .min_by_key(|(expr_range, _scope)| expr_range.len())
907         .map(|(expr_range, scope)| {
908             adjust(db, scopes, source_map, expr_range, from_file, offset).unwrap_or(*scope)
909         })
910 }
911 
912 // XXX: during completion, cursor might be outside of any particular
913 // expression. Try to figure out the correct scope...
adjust( db: &dyn HirDatabase, scopes: &ExprScopes, source_map: &BodySourceMap, expr_range: TextRange, from_file: HirFileId, offset: TextSize, ) -> Option<ScopeId>914 fn adjust(
915     db: &dyn HirDatabase,
916     scopes: &ExprScopes,
917     source_map: &BodySourceMap,
918     expr_range: TextRange,
919     from_file: HirFileId,
920     offset: TextSize,
921 ) -> Option<ScopeId> {
922     let child_scopes = scopes
923         .scope_by_expr()
924         .iter()
925         .filter_map(|(id, scope)| {
926             let source = source_map.expr_syntax(*id).ok()?;
927             // FIXME: correctly handle macro expansion
928             if source.file_id != from_file {
929                 return None;
930             }
931             let root = source.file_syntax(db.upcast());
932             let node = source.value.to_node(&root);
933             Some((node.syntax().text_range(), scope))
934         })
935         .filter(|&(range, _)| {
936             range.start() <= offset && expr_range.contains_range(range) && range != expr_range
937         });
938 
939     child_scopes
940         .max_by(|&(r1, _), &(r2, _)| {
941             if r1.contains_range(r2) {
942                 std::cmp::Ordering::Greater
943             } else if r2.contains_range(r1) {
944                 std::cmp::Ordering::Less
945             } else {
946                 r1.start().cmp(&r2.start())
947             }
948         })
949         .map(|(_ptr, scope)| *scope)
950 }
951 
952 #[inline]
resolve_hir_path( db: &dyn HirDatabase, resolver: &Resolver, path: &Path, ) -> Option<PathResolution>953 pub(crate) fn resolve_hir_path(
954     db: &dyn HirDatabase,
955     resolver: &Resolver,
956     path: &Path,
957 ) -> Option<PathResolution> {
958     resolve_hir_path_(db, resolver, path, false)
959 }
960 
961 #[inline]
resolve_hir_path_as_attr_macro( db: &dyn HirDatabase, resolver: &Resolver, path: &Path, ) -> Option<Macro>962 pub(crate) fn resolve_hir_path_as_attr_macro(
963     db: &dyn HirDatabase,
964     resolver: &Resolver,
965     path: &Path,
966 ) -> Option<Macro> {
967     resolver
968         .resolve_path_as_macro(db.upcast(), path.mod_path()?, Some(MacroSubNs::Attr))
969         .map(Into::into)
970 }
971 
resolve_hir_path_( db: &dyn HirDatabase, resolver: &Resolver, path: &Path, prefer_value_ns: bool, ) -> Option<PathResolution>972 fn resolve_hir_path_(
973     db: &dyn HirDatabase,
974     resolver: &Resolver,
975     path: &Path,
976     prefer_value_ns: bool,
977 ) -> Option<PathResolution> {
978     let types = || {
979         let (ty, unresolved) = match path.type_anchor() {
980             Some(type_ref) => {
981                 let (_, res) = TyLoweringContext::new(db, resolver, resolver.module().into())
982                     .lower_ty_ext(type_ref);
983                 res.map(|ty_ns| (ty_ns, path.segments().first()))
984             }
985             None => {
986                 let (ty, remaining_idx) = resolver.resolve_path_in_type_ns(db.upcast(), path)?;
987                 match remaining_idx {
988                     Some(remaining_idx) => {
989                         if remaining_idx + 1 == path.segments().len() {
990                             Some((ty, path.segments().last()))
991                         } else {
992                             None
993                         }
994                     }
995                     None => Some((ty, None)),
996                 }
997             }
998         }?;
999 
1000         // If we are in a TypeNs for a Trait, and we have an unresolved name, try to resolve it as a type
1001         // within the trait's associated types.
1002         if let (Some(unresolved), &TypeNs::TraitId(trait_id)) = (&unresolved, &ty) {
1003             if let Some(type_alias_id) =
1004                 db.trait_data(trait_id).associated_type_by_name(unresolved.name)
1005             {
1006                 return Some(PathResolution::Def(ModuleDefId::from(type_alias_id).into()));
1007             }
1008         }
1009 
1010         let res = match ty {
1011             TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
1012             TypeNs::GenericParam(id) => PathResolution::TypeParam(id.into()),
1013             TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
1014                 PathResolution::Def(Adt::from(it).into())
1015             }
1016             TypeNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
1017             TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
1018             TypeNs::BuiltinType(it) => PathResolution::Def(BuiltinType::from(it).into()),
1019             TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
1020             TypeNs::TraitAliasId(it) => PathResolution::Def(TraitAlias::from(it).into()),
1021         };
1022         match unresolved {
1023             Some(unresolved) => resolver
1024                 .generic_def()
1025                 .and_then(|def| {
1026                     hir_ty::associated_type_shorthand_candidates(
1027                         db,
1028                         def,
1029                         res.in_type_ns()?,
1030                         |name, id| (name == unresolved.name).then_some(id),
1031                     )
1032                 })
1033                 .map(TypeAlias::from)
1034                 .map(Into::into)
1035                 .map(PathResolution::Def),
1036             None => Some(res),
1037         }
1038     };
1039 
1040     let body_owner = resolver.body_owner();
1041     let values = || {
1042         resolver.resolve_path_in_value_ns_fully(db.upcast(), path).and_then(|val| {
1043             let res = match val {
1044                 ValueNs::LocalBinding(binding_id) => {
1045                     let var = Local { parent: body_owner?, binding_id };
1046                     PathResolution::Local(var)
1047                 }
1048                 ValueNs::FunctionId(it) => PathResolution::Def(Function::from(it).into()),
1049                 ValueNs::ConstId(it) => PathResolution::Def(Const::from(it).into()),
1050                 ValueNs::StaticId(it) => PathResolution::Def(Static::from(it).into()),
1051                 ValueNs::StructId(it) => PathResolution::Def(Struct::from(it).into()),
1052                 ValueNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
1053                 ValueNs::ImplSelf(impl_id) => PathResolution::SelfType(impl_id.into()),
1054                 ValueNs::GenericParam(id) => PathResolution::ConstParam(id.into()),
1055             };
1056             Some(res)
1057         })
1058     };
1059 
1060     let items = || {
1061         resolver
1062             .resolve_module_path_in_items(db.upcast(), path.mod_path()?)
1063             .take_types()
1064             .map(|it| PathResolution::Def(it.into()))
1065     };
1066 
1067     let macros = || {
1068         resolver
1069             .resolve_path_as_macro(db.upcast(), path.mod_path()?, None)
1070             .map(|def| PathResolution::Def(ModuleDef::Macro(def.into())))
1071     };
1072 
1073     if prefer_value_ns { values().or_else(types) } else { types().or_else(values) }
1074         .or_else(items)
1075         .or_else(macros)
1076 }
1077 
1078 /// Resolves a path where we know it is a qualifier of another path.
1079 ///
1080 /// For example, if we have:
1081 /// ```
1082 /// mod my {
1083 ///     pub mod foo {
1084 ///         struct Bar;
1085 ///     }
1086 ///
1087 ///     pub fn foo() {}
1088 /// }
1089 /// ```
1090 /// then we know that `foo` in `my::foo::Bar` refers to the module, not the function.
resolve_hir_path_qualifier( db: &dyn HirDatabase, resolver: &Resolver, path: &Path, ) -> Option<PathResolution>1091 fn resolve_hir_path_qualifier(
1092     db: &dyn HirDatabase,
1093     resolver: &Resolver,
1094     path: &Path,
1095 ) -> Option<PathResolution> {
1096     resolver
1097         .resolve_path_in_type_ns_fully(db.upcast(), &path)
1098         .map(|ty| match ty {
1099             TypeNs::SelfType(it) => PathResolution::SelfType(it.into()),
1100             TypeNs::GenericParam(id) => PathResolution::TypeParam(id.into()),
1101             TypeNs::AdtSelfType(it) | TypeNs::AdtId(it) => {
1102                 PathResolution::Def(Adt::from(it).into())
1103             }
1104             TypeNs::EnumVariantId(it) => PathResolution::Def(Variant::from(it).into()),
1105             TypeNs::TypeAliasId(it) => PathResolution::Def(TypeAlias::from(it).into()),
1106             TypeNs::BuiltinType(it) => PathResolution::Def(BuiltinType::from(it).into()),
1107             TypeNs::TraitId(it) => PathResolution::Def(Trait::from(it).into()),
1108             TypeNs::TraitAliasId(it) => PathResolution::Def(TraitAlias::from(it).into()),
1109         })
1110         .or_else(|| {
1111             resolver
1112                 .resolve_module_path_in_items(db.upcast(), path.mod_path()?)
1113                 .take_types()
1114                 .map(|it| PathResolution::Def(it.into()))
1115         })
1116 }
1117