2 files changed, 32 insertions, 2 deletions
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 20828067c46..ff34555920d 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -3183,8 +3183,7 @@ impl<'tcx> TyCtxt<'tcx> {
 
     /// Whether this is a trait implementation that has `#[diagnostic::do_not_recommend]`
     pub fn do_not_recommend_impl(self, def_id: DefId) -> bool {
-        matches!(self.def_kind(def_id), DefKind::Impl { of_trait: true })
-            && self.impl_trait_header(def_id).is_some_and(|header| header.do_not_recommend)
+        self.get_diagnostic_attr(def_id, sym::do_not_recommend).is_some()
     }
 }
 
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index ee70a6346d9..ee4f67f0e93 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -1797,6 +1797,37 @@ impl<'tcx> TyCtxt<'tcx> {
         }
     }
 
+    /// Get an attribute from the diagnostic attribute namespace
+    ///
+    /// This function requests an attribute with the following structure:
+    ///
+    /// `#[diagnostic::$attr]`
+    ///
+    /// This function performs feature checking, so if an attribute is returned
+    /// it can be used by the consumer
+    pub fn get_diagnostic_attr(
+        self,
+        did: impl Into<DefId>,
+        attr: Symbol,
+    ) -> Option<&'tcx ast::Attribute> {
+        let did: DefId = did.into();
+        if did.as_local().is_some() {
+            // it's a crate local item, we need to check feature flags
+            if rustc_feature::is_stable_diagnostic_attribute(attr, self.features()) {
+                self.get_attrs_by_path(did, &[sym::diagnostic, sym::do_not_recommend]).next()
+            } else {
+                None
+            }
+        } else {
+            // we filter out unstable diagnostic attributes before
+            // encoding attributes
+            debug_assert!(rustc_feature::encode_cross_crate(attr));
+            self.item_attrs(did)
+                .iter()
+                .find(|a| matches!(a.path().as_ref(), [sym::diagnostic, a] if *a == attr))
+        }
+    }
+
     pub fn get_attrs_by_path<'attr>(
         self,
         did: DefId,