Unnamed repository; edit this file 'description' to name the repository.
| -rw-r--r-- | crates/hir-ty/src/inhabitedness.rs | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/crates/hir-ty/src/inhabitedness.rs b/crates/hir-ty/src/inhabitedness.rs index 505f80f324..39324d2730 100644 --- a/crates/hir-ty/src/inhabitedness.rs +++ b/crates/hir-ty/src/inhabitedness.rs @@ -1,8 +1,5 @@ //! Type inhabitedness logic. -use std::{ - collections::HashMap, - ops::ControlFlow::{self, Break, Continue}, -}; +use std::ops::ControlFlow::{self, Break, Continue}; use chalk_ir::{ visit::{TypeSuperVisitable, TypeVisitable, TypeVisitor}, @@ -12,7 +9,7 @@ use hir_def::{ adt::VariantData, attr::Attrs, visibility::Visibility, AdtId, EnumVariantId, HasModule, Lookup, ModuleId, VariantId, }; -use rustc_hash::FxHashMap; +use rustc_hash::FxHashSet; use crate::{ consteval::try_const_usize, db::HirDatabase, Binders, Interner, Substitution, Ty, TyKind, @@ -21,7 +18,7 @@ use crate::{ /// Checks whether a type is visibly uninhabited from a particular module. pub(crate) fn is_ty_uninhabited_from(ty: &Ty, target_mod: ModuleId, db: &dyn HirDatabase) -> bool { let mut uninhabited_from = - UninhabitedFrom { target_mod, db, max_depth: 500, recursive_ty: HashMap::default() }; + UninhabitedFrom { target_mod, db, max_depth: 500, recursive_ty: FxHashSet::default() }; let inhabitedness = ty.visit_with(&mut uninhabited_from, DebruijnIndex::INNERMOST); inhabitedness == BREAK_VISIBLY_UNINHABITED } @@ -38,7 +35,7 @@ pub(crate) fn is_enum_variant_uninhabited_from( let is_local = variant.parent.lookup(db.upcast()).container.krate() == target_mod.krate(); let mut uninhabited_from = - UninhabitedFrom { target_mod, db, max_depth: 500, recursive_ty: HashMap::default() }; + UninhabitedFrom { target_mod, db, max_depth: 500, recursive_ty: FxHashSet::default() }; let inhabitedness = uninhabited_from.visit_variant( variant.into(), &enum_data.variants[variant.local_id].variant_data, @@ -51,7 +48,7 @@ pub(crate) fn is_enum_variant_uninhabited_from( struct UninhabitedFrom<'a> { target_mod: ModuleId, - recursive_ty: FxHashMap<Ty, ()>, + recursive_ty: FxHashSet<Ty>, // guard for preventing stack overflow in non trivial non terminating types max_depth: usize, db: &'a dyn HirDatabase, @@ -74,12 +71,12 @@ impl TypeVisitor<Interner> for UninhabitedFrom<'_> { ty: &Ty, outer_binder: DebruijnIndex, ) -> ControlFlow<VisiblyUninhabited> { - if self.recursive_ty.contains_key(ty) || self.max_depth == 0 { + if self.recursive_ty.contains(ty) || self.max_depth == 0 { // rustc considers recursive types always inhabited. I think it is valid to consider // recursive types as always uninhabited, but we should do what rustc is doing. return CONTINUE_OPAQUELY_INHABITED; } - self.recursive_ty.insert(ty.clone(), ()); + self.recursive_ty.insert(ty.clone()); self.max_depth -= 1; let r = match ty.kind(Interner) { TyKind::Adt(adt, subst) => self.visit_adt(adt.0, subst), |