Rollup merge of #108923 - spastorino:new-rpitit-9, r=compiler-errors

Make fns from other crates with RPITIT work for -Zlower-impl-trait-in-trait-to-assoc-ty

Only the last two commits are meaningful.

r? `@compiler-errors`

4 files changed, 16 insertions, 3 deletions

diff --git a/compiler/rustc_hir/src/definitions.rs b/compiler/rustc_hir/src/definitions.rs
index 8ceb176491b..3c4fc9cb530 100644
--- a/compiler/rustc_hir/src/definitions.rs
+++ b/compiler/rustc_hir/src/definitions.rs
@@ -404,8 +404,12 @@ impl DefPathData {
         match *self {
             TypeNs(name) | ValueNs(name) | MacroNs(name) | LifetimeNs(name) => Some(name),
 
+            // We use this name when collecting `ModChild`s.
+            // FIXME this could probably be removed with some refactoring to the name resolver.
+            ImplTraitAssocTy => Some(kw::Empty),
+
             Impl | ForeignMod | CrateRoot | Use | GlobalAsm | ClosureExpr | Ctor | AnonConst
-            | ImplTrait | ImplTraitAssocTy => None,
+            | ImplTrait => None,
         }
     }
 
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index bbab8a62a2b..59e2e57e6c2 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -1356,13 +1356,14 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
         debug!("EncodeContext::encode_info_for_impl_item({:?})", def_id);
         let tcx = self.tcx;
 
-        let ast_item = self.tcx.hir().expect_impl_item(def_id.expect_local());
-        self.tables.impl_defaultness.set_some(def_id.index, ast_item.defaultness);
+        let defaultness = self.tcx.impl_defaultness(def_id.expect_local());
+        self.tables.impl_defaultness.set_some(def_id.index, defaultness);
         let impl_item = self.tcx.associated_item(def_id);
         self.tables.assoc_container.set_some(def_id.index, impl_item.container);
 
         match impl_item.kind {
             ty::AssocKind::Fn => {
+                let ast_item = self.tcx.hir().expect_impl_item(def_id.expect_local());
                 let hir::ImplItemKind::Fn(ref sig, body) = ast_item.kind else { bug!() };
                 self.tables.asyncness.set_some(def_id.index, sig.header.asyncness);
                 record_array!(self.tables.fn_arg_names[def_id] <- self.tcx.hir().body_param_names(body));
diff --git a/compiler/rustc_ty_utils/src/assoc.rs b/compiler/rustc_ty_utils/src/assoc.rs
index 867974749d5..a2816124538 100644
--- a/compiler/rustc_ty_utils/src/assoc.rs
+++ b/compiler/rustc_ty_utils/src/assoc.rs
@@ -328,6 +328,9 @@ fn impl_associated_item_for_impl_trait_in_trait(
     // `opt_local_def_id_to_hir_id` with `None`.
     impl_assoc_ty.opt_local_def_id_to_hir_id(None);
 
+    // Copy span of the opaque.
+    impl_assoc_ty.def_ident_span(Some(span));
+
     impl_assoc_ty.associated_item(ty::AssocItem {
         name: kw::Empty,
         kind: ty::AssocKind::Type,
@@ -342,6 +345,9 @@ fn impl_associated_item_for_impl_trait_in_trait(
     // extra predicates to assume.
     impl_assoc_ty.param_env(tcx.param_env(impl_fn_def_id));
 
+    // Copy visility of the containing function.
+    impl_assoc_ty.visibility(tcx.visibility(impl_fn_def_id));
+
     // Copy impl_defaultness of the containing function.
     impl_assoc_ty.impl_defaultness(tcx.impl_defaultness(impl_fn_def_id));
 
diff --git a/tests/ui/impl-trait/in-trait/foreign.rs b/tests/ui/impl-trait/in-trait/foreign.rs
index 6341f5b4284..df77372aabd 100644
--- a/tests/ui/impl-trait/in-trait/foreign.rs
+++ b/tests/ui/impl-trait/in-trait/foreign.rs
@@ -1,5 +1,7 @@
 // check-pass
 // aux-build: rpitit.rs
+// [next] compile-flags: -Zlower-impl-trait-in-trait-to-assoc-ty
+// revisions: current next
 
 extern crate rpitit;