bendns' repos / rust-analyzer
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.rs86
1 files changed, 55 insertions, 31 deletions
diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs
index b4da1a308d..d90ca77b55 100644
--- a/crates/hir-ty/src/infer.rs
+++ b/crates/hir-ty/src/infer.rs
@@ -33,7 +33,7 @@ use hir_def::{
TraitId, TypeAliasId, VariantId,
};
use hir_expand::name::{name, Name};
-use la_arena::ArenaMap;
+use la_arena::{ArenaMap, Entry};
use rustc_hash::{FxHashMap, FxHashSet};
use stdx::{always, never};
@@ -676,36 +676,16 @@ 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);
- fold_tys(
- return_ty,
- |ty, _| {
- let opaque_ty_id = match ty.kind(Interner) {
- TyKind::OpaqueType(opaque_ty_id, _) => *opaque_ty_id,
- _ => return ty,
- };
- let idx = match self.db.lookup_intern_impl_trait_id(opaque_ty_id.into()) {
- ImplTraitId::ReturnTypeImplTrait(_, idx) => idx,
- _ => unreachable!(),
- };
- let bounds = (*rpits).map_ref(|rpits| {
- rpits.impl_traits[idx].bounds.map_ref(|it| it.into_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, &fn_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
- self.push_obligation(var_predicate.cast(Interner));
- }
- self.result.type_of_rpit.insert(idx, var.clone());
- var
- },
- DebruijnIndex::INNERMOST,
- )
+ let result =
+ self.insert_inference_vars_for_rpit(return_ty, rpits.clone(), fn_placeholders);
+ let rpits = rpits.skip_binders();
+ for (id, _) in rpits.impl_traits.iter() {
+ if let Entry::Vacant(e) = self.result.type_of_rpit.entry(id) {
+ never!("Missed RPIT in `insert_inference_vars_for_rpit`");
+ e.insert(TyKind::Error.intern(Interner));
+ }
+ }
+ result
} else {
return_ty
};
@@ -714,6 +694,50 @@ impl<'a> InferenceContext<'a> {
self.return_coercion = Some(CoerceMany::new(self.return_ty.clone()));
}
+ fn insert_inference_vars_for_rpit<T>(
+ &mut self,
+ t: T,
+ rpits: Arc<chalk_ir::Binders<crate::ReturnTypeImplTraits>>,
+ fn_placeholders: Substitution,
+ ) -> T
+ where
+ T: crate::HasInterner<Interner = Interner> + crate::TypeFoldable<Interner>,
+ {
+ fold_tys(
+ t,
+ |ty, _| {
+ let opaque_ty_id = match ty.kind(Interner) {
+ TyKind::OpaqueType(opaque_ty_id, _) => *opaque_ty_id,
+ _ => return ty,
+ };
+ let idx = match self.db.lookup_intern_impl_trait_id(opaque_ty_id.into()) {
+ ImplTraitId::ReturnTypeImplTrait(_, idx) => idx,
+ _ => unreachable!(),
+ };
+ let bounds = (*rpits)
+ .map_ref(|rpits| rpits.impl_traits[idx].bounds.map_ref(|it| it.into_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, &fn_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_rpit(
+ var_predicate,
+ rpits.clone(),
+ fn_placeholders.clone(),
+ );
+ self.push_obligation(var_predicate.cast(Interner));
+ }
+ self.result.type_of_rpit.insert(idx, var.clone());
+ var
+ },
+ DebruijnIndex::INNERMOST,
+ )
+ }
+
fn infer_body(&mut self) {
match self.return_coercion {
Some(_) => self.infer_return(self.body.body_expr),