Auto merge of #88121 - camelid:better-recursive-alias-error, r=estebank

Improve errors for recursive type aliases

Fixes #17539.

1 files changed, 18 insertions, 0 deletions

diff --git a/compiler/rustc_query_impl/src/util.rs b/compiler/rustc_query_impl/src/util.rs
new file mode 100644
index 00000000000..517c107b5d9
--- /dev/null
+++ b/compiler/rustc_query_impl/src/util.rs
@@ -0,0 +1,18 @@
+use rustc_hir::def::DefKind;
+use rustc_query_system::query::SimpleDefKind;
+
+/// Convert a [`DefKind`] to a [`SimpleDefKind`].
+///
+/// *See [`SimpleDefKind`]'s docs for more information.*
+pub(crate) fn def_kind_to_simple_def_kind(def_kind: DefKind) -> SimpleDefKind {
+    match def_kind {
+        DefKind::Struct => SimpleDefKind::Struct,
+        DefKind::Enum => SimpleDefKind::Enum,
+        DefKind::Union => SimpleDefKind::Union,
+        DefKind::Trait => SimpleDefKind::Trait,
+        DefKind::TyAlias => SimpleDefKind::TyAlias,
+        DefKind::TraitAlias => SimpleDefKind::TraitAlias,
+
+        _ => SimpleDefKind::Other,
+    }
+}