bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/method_resolution.rs')
-rw-r--r--crates/hir-ty/src/method_resolution.rs84
1 files changed, 54 insertions, 30 deletions
diff --git a/crates/hir-ty/src/method_resolution.rs b/crates/hir-ty/src/method_resolution.rs
index 3a1a3f4fde..50859475e1 100644
--- a/crates/hir-ty/src/method_resolution.rs
+++ b/crates/hir-ty/src/method_resolution.rs
@@ -22,10 +22,10 @@ use crate::{
from_foreign_def_id,
infer::{unify::InferenceTable, Adjust, Adjustment, AutoBorrow, OverloadedDeref, PointerCast},
primitive::{FloatTy, IntTy, UintTy},
- static_lifetime,
+ static_lifetime, to_chalk_trait_id,
utils::all_super_traits,
AdtId, Canonical, CanonicalVarKinds, DebruijnIndex, ForeignDefId, InEnvironment, Interner,
- Scalar, TraitEnvironment, TraitRefExt, Ty, TyBuilder, TyExt, TyKind,
+ Scalar, Substitution, TraitEnvironment, TraitRef, TraitRefExt, Ty, TyBuilder, TyExt, TyKind,
};
/// This is used as a key for indexing impls.
@@ -624,52 +624,76 @@ pub(crate) fn iterate_method_candidates<T>(
slot
}
+/// Looks up the impl method that actually runs for the trait method `func`.
+///
+/// Returns `func` if it's not a method defined in a trait or the lookup failed.
pub fn lookup_impl_method(
- self_ty: &Ty,
db: &dyn HirDatabase,
env: Arc<TraitEnvironment>,
- trait_: TraitId,
+ func: FunctionId,
+ fn_subst: Substitution,
+) -> FunctionId {
+ let trait_id = match func.lookup(db.upcast()).container {
+ ItemContainerId::TraitId(id) => id,
+ _ => return func,
+ };
+ let trait_params = db.generic_params(trait_id.into()).type_or_consts.len();
+ let fn_params = fn_subst.len(Interner) - trait_params;
+ let trait_ref = TraitRef {
+ trait_id: to_chalk_trait_id(trait_id),
+ substitution: Substitution::from_iter(Interner, fn_subst.iter(Interner).skip(fn_params)),
+ };
+
+ let name = &db.function_data(func).name;
+ lookup_impl_method_for_trait_ref(trait_ref, db, env, name).unwrap_or(func)
+}
+
+fn lookup_impl_method_for_trait_ref(
+ trait_ref: TraitRef,
+ db: &dyn HirDatabase,
+ env: Arc<TraitEnvironment>,
name: &Name,
) -> Option<FunctionId> {
- let self_ty_fp = TyFingerprint::for_trait_impl(self_ty)?;
- let trait_impls = db.trait_impls_in_deps(env.krate);
- let impls = trait_impls.for_trait_and_self_ty(trait_, self_ty_fp);
- let mut table = InferenceTable::new(db, env.clone());
- find_matching_impl(impls, &mut table, &self_ty).and_then(|data| {
- data.items.iter().find_map(|it| match it {
- AssocItemId::FunctionId(f) => (db.function_data(*f).name == *name).then(|| *f),
- _ => None,
- })
+ let self_ty = trait_ref.self_type_parameter(Interner);
+ let self_ty_fp = TyFingerprint::for_trait_impl(&self_ty)?;
+ let impls = db.trait_impls_in_deps(env.krate);
+ let impls = impls.for_trait_and_self_ty(trait_ref.hir_trait_id(), self_ty_fp);
+
+ let table = InferenceTable::new(db, env);
+
+ let impl_data = find_matching_impl(impls, table, trait_ref)?;
+ impl_data.items.iter().find_map(|it| match it {
+ AssocItemId::FunctionId(f) => (db.function_data(*f).name == *name).then(|| *f),
+ _ => None,
})
}
fn find_matching_impl(
mut impls: impl Iterator<Item = ImplId>,
- table: &mut InferenceTable<'_>,
- self_ty: &Ty,
+ mut table: InferenceTable<'_>,
+ actual_trait_ref: TraitRef,
) -> Option<Arc<ImplData>> {
let db = table.db;
loop {
let impl_ = impls.next()?;
let r = table.run_in_snapshot(|table| {
let impl_data = db.impl_data(impl_);
- let substs =
+ let impl_substs =
TyBuilder::subst_for_def(db, impl_, None).fill_with_inference_vars(table).build();
- let impl_ty = db.impl_self_ty(impl_).substitute(Interner, &substs);
-
- table
- .unify(self_ty, &impl_ty)
- .then(|| {
- let wh_goals =
- crate::chalk_db::convert_where_clauses(db, impl_.into(), &substs)
- .into_iter()
- .map(|b| b.cast(Interner));
+ let trait_ref = db
+ .impl_trait(impl_)
+ .expect("non-trait method in find_matching_impl")
+ .substitute(Interner, &impl_substs);
- let goal = crate::Goal::all(Interner, wh_goals);
+ if !table.unify(&trait_ref, &actual_trait_ref) {
+ return None;
+ }
- table.try_obligation(goal).map(|_| impl_data)
- })
- .flatten()
+ let wcs = crate::chalk_db::convert_where_clauses(db, impl_.into(), &impl_substs)
+ .into_iter()
+ .map(|b| b.cast(Interner));
+ let goal = crate::Goal::all(Interner, wcs);
+ table.try_obligation(goal).map(|_| impl_data)
});
if r.is_some() {
break r;
@@ -1214,7 +1238,7 @@ fn is_valid_fn_candidate(
let expected_receiver =
sig.map(|s| s.params()[0].clone()).substitute(Interner, &fn_subst);
- check_that!(table.unify(&receiver_ty, &expected_receiver));
+ check_that!(table.unify(receiver_ty, &expected_receiver));
}
if let ItemContainerId::ImplId(impl_id) = container {