language-servers/rust-analyzer
1
0
Fork 0
mirror of https://github.com/rust-lang/rust-analyzer.git synced 2025-10-03 23:25:03 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

Infer types of nested RPITs

Browse source
This commit is contained in:
hkalbasi 2023-04-11 04:32:11 +03:30
parent 44cf8ef49a
commit a584cb998f
5 changed files with 105 additions and 34 deletions
Download patch file Download diff file Expand all files Collapse all files

86
crates/hir-ty/src/infer.rs
View file

@ -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),