Resolve self type alias in impl for RTN

Author: compiler-errors

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -1965,7 +1965,25 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
                         };
                         (bound_vars, assoc_item.def_id, item_segment)
                     }
-                    Res::SelfTyAlias { is_trait_impl: true, .. } => todo!(),
+                    Res::SelfTyAlias { alias_to: impl_def_id, is_trait_impl: true, .. } => {
+                        let hir::ItemKind::Impl(hir::Impl { of_trait: Some(trait_ref), .. }) =
+                            self.tcx.hir_node_by_def_id(impl_def_id.expect_local()).expect_item().kind
+                        else {
+                            return;
+                        };
+                        let Some(trait_def_id) = trait_ref.trait_def_id() else {
+                            return;
+                        };
+                        let Some((bound_vars, assoc_item)) = BoundVarContext::supertrait_hrtb_vars(
+                            self.tcx,
+                            trait_def_id,
+                            item_segment.ident,
+                            ty::AssocKind::Fn,
+                        ) else {
+                            return;
+                        };
+                        (bound_vars, assoc_item.def_id, item_segment)
+                    }
                     _ => return,
                 }
             }

tests/ui/associated-type-bounds/return-type-notation/path-self-qself.rs

@@ -13,4 +13,15 @@ trait Bar: Foo {
         Self::method(..): Send;
 }
 
+fn is_send(_: impl Send) {}
+
+impl<T: Foo> Bar for T {
+    fn other()
+    where
+        Self::method(..): Send,
+    {
+        is_send(Self::method());
+    }
+}
+
 fn main() {}