Merge #2453

2453: Handle various cycles r=matklad a=flodiebold

 - handle `impl Trait<Self> for SomeType`, which is allowed. This necessitated splitting the `impl_ty` query, but I think the result actually makes a lot of code nicer. This should fix #2446.
 - add recovery for `impl Trait for SomeType<Self>`
 - add recovery for `type Type = Foo<Type>`
 - add recovery for cycles in generic param env

Co-authored-by: Florian Diebold <[email protected]>

2 files changed, 3 insertions, 6 deletions

diff --git a/crates/ra_hir_ty/src/infer/coerce.rs b/crates/ra_hir_ty/src/infer/coerce.rs
index 719a0f395..064993d34 100644
--- a/crates/ra_hir_ty/src/infer/coerce.rs
+++ b/crates/ra_hir_ty/src/infer/coerce.rs
@@ -8,7 +8,7 @@ use hir_def::{lang_item::LangItemTarget, resolver::Resolver, type_ref::Mutabilit
 use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
-use crate::{autoderef, db::HirDatabase, ImplTy, Substs, Ty, TypeCtor, TypeWalk};
+use crate::{autoderef, db::HirDatabase, Substs, Ty, TypeCtor, TypeWalk};
 
 use super::{InEnvironment, InferTy, InferenceContext, TypeVarValue};
 
@@ -54,10 +54,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
         impls
             .iter()
             .filter_map(|&impl_id| {
-                let trait_ref = match db.impl_ty(impl_id) {
-                    ImplTy::TraitRef(it) => it,
-                    ImplTy::Inherent(_) => return None,
-                };
+                let trait_ref = db.impl_trait(impl_id)?;
 
                 // `CoerseUnsized` has one generic parameter for the target type.
                 let cur_from_ty = trait_ref.substs.0.get(0)?;
diff --git a/crates/ra_hir_ty/src/infer/path.rs b/crates/ra_hir_ty/src/infer/path.rs
index 14be66836..bbf146418 100644
--- a/crates/ra_hir_ty/src/infer/path.rs
+++ b/crates/ra_hir_ty/src/infer/path.rs
@@ -244,7 +244,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                 ContainerId::ImplId(it) => it,
                 _ => return None,
             };
-            let self_ty = self.db.impl_ty(impl_id).self_type().clone();
+            let self_ty = self.db.impl_self_ty(impl_id).clone();
             let self_ty_substs = self_ty.substs()?;
             let actual_substs = actual_def_ty.substs()?;