Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/infer.rs')
| -rw-r--r-- | crates/hir-ty/src/infer.rs | 79 |
1 files changed, 68 insertions, 11 deletions
diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs index 8defeee5e8..8b4e98c550 100644 --- a/crates/hir-ty/src/infer.rs +++ b/crates/hir-ty/src/infer.rs @@ -604,6 +604,11 @@ fn find_continuable( } } +enum ImplTraitReplacingMode { + ReturnPosition(FxHashSet<Ty>), + TypeAlias, +} + impl<'a> InferenceContext<'a> { fn new( db: &'a dyn HirDatabase, @@ -825,13 +830,19 @@ impl<'a> InferenceContext<'a> { self.write_binding_ty(self_param, ty); } } - let mut params_and_ret_tys = Vec::new(); + let mut tait_candidates = FxHashSet::default(); for (ty, pat) in param_tys.zip(&*self.body.params) { let ty = self.insert_type_vars(ty); let ty = self.normalize_associated_types_in(ty); self.infer_top_pat(*pat, &ty); - params_and_ret_tys.push(ty); + if ty + .data(Interner) + .flags + .intersects(TypeFlags::HAS_TY_OPAQUE.union(TypeFlags::HAS_TY_INFER)) + { + tait_candidates.insert(ty); + } } let return_ty = &*data.ret_type; @@ -844,7 +855,12 @@ impl<'a> InferenceContext<'a> { let return_ty = if let Some(rpits) = self.db.return_type_impl_traits(func) { // RPIT opaque types use substitution of their parent function. let fn_placeholders = TyBuilder::placeholder_subst(self.db, func); - let result = self.insert_inference_vars_for_impl_trait(return_ty, fn_placeholders); + let mut mode = ImplTraitReplacingMode::ReturnPosition(FxHashSet::default()); + let result = + self.insert_inference_vars_for_impl_trait(return_ty, fn_placeholders, &mut mode); + if let ImplTraitReplacingMode::ReturnPosition(taits) = mode { + tait_candidates.extend(taits); + } let rpits = rpits.skip_binders(); for (id, _) in rpits.impl_traits.iter() { if let Entry::Vacant(e) = self.result.type_of_rpit.entry(id) { @@ -863,11 +879,23 @@ impl<'a> InferenceContext<'a> { // Functions might be defining usage sites of TAITs. // To define an TAITs, that TAIT must appear in the function's signatures. // So, it suffices to check for params and return types. - params_and_ret_tys.push(self.return_ty.clone()); - self.make_tait_coercion_table(params_and_ret_tys.iter()); + if self + .return_ty + .data(Interner) + .flags + .intersects(TypeFlags::HAS_TY_OPAQUE.union(TypeFlags::HAS_TY_INFER)) + { + tait_candidates.insert(self.return_ty.clone()); + } + self.make_tait_coercion_table(tait_candidates.iter()); } - fn insert_inference_vars_for_impl_trait<T>(&mut self, t: T, placeholders: Substitution) -> T + fn insert_inference_vars_for_impl_trait<T>( + &mut self, + t: T, + placeholders: Substitution, + mode: &mut ImplTraitReplacingMode, + ) -> T where T: crate::HasInterner<Interner = Interner> + crate::TypeFoldable<Interner>, { @@ -880,10 +908,31 @@ impl<'a> InferenceContext<'a> { }; let (impl_traits, idx) = match self.db.lookup_intern_impl_trait_id(opaque_ty_id.into()) { + // We don't replace opaque types from other kind with inference vars + // because `insert_inference_vars_for_impl_traits` for each kinds + // and unreplaced opaque types of other kind are resolved while + // inferencing because of `tait_coercion_table`. + // Moreover, calling `insert_inference_vars_for_impl_traits` with same + // `placeholders` for other kind may cause trouble because + // the substs for the bounds of each impl traits do not match ImplTraitId::ReturnTypeImplTrait(def, idx) => { + if matches!(mode, ImplTraitReplacingMode::TypeAlias) { + // RPITs don't have `tait_coercion_table`, so use inserted inference + // vars for them. + if let Some(ty) = self.result.type_of_rpit.get(idx) { + return ty.clone(); + } + return ty; + } (self.db.return_type_impl_traits(def), idx) } ImplTraitId::TypeAliasImplTrait(def, idx) => { + if let ImplTraitReplacingMode::ReturnPosition(taits) = mode { + // Gather TAITs while replacing RPITs because TAITs inside RPITs + // may not visited while replacing TAITs + taits.insert(ty.clone()); + return ty; + } (self.db.type_alias_impl_traits(def), idx) } _ => unreachable!(), @@ -892,16 +941,20 @@ impl<'a> InferenceContext<'a> { return ty; }; let bounds = (*impl_traits) - .map_ref(|rpits| rpits.impl_traits[idx].bounds.map_ref(|it| it.iter())); + .map_ref(|its| its.impl_traits[idx].bounds.map_ref(|it| it.iter())); let var = self.table.new_type_var(); let var_subst = Substitution::from1(Interner, var.clone()); for bound in bounds { - let predicate = bound.map(|it| it.cloned()).substitute(Interner, &placeholders); + let predicate = bound.map(|it| it.cloned()); + let predicate = predicate.substitute(Interner, &placeholders); let (var_predicate, binders) = predicate.substitute(Interner, &var_subst).into_value_and_skipped_binders(); always!(binders.is_empty(Interner)); // quantified where clauses not yet handled - let var_predicate = self - .insert_inference_vars_for_impl_trait(var_predicate, placeholders.clone()); + let var_predicate = self.insert_inference_vars_for_impl_trait( + var_predicate, + placeholders.clone(), + mode, + ); self.push_obligation(var_predicate.cast(Interner)); } self.result.type_of_rpit.insert(idx, var.clone()); @@ -1038,7 +1091,11 @@ impl<'a> InferenceContext<'a> { self.db.lookup_intern_impl_trait_id(id.into()) { let subst = TyBuilder::placeholder_subst(self.db, alias_id); - let ty = self.insert_inference_vars_for_impl_trait(ty, subst); + let ty = self.insert_inference_vars_for_impl_trait( + ty, + subst, + &mut ImplTraitReplacingMode::TypeAlias, + ); Some((id, ty)) } else { None |