+ /// Evaluates the default-impl stability of an item.
+ ///
+ /// Returns `EvalResult::Allow` if the item's default implementation is stable, or unstable but the corresponding
+ /// `#![feature]` has been provided. Returns `EvalResult::Deny` which describes the offending
+ /// unstable feature otherwise.
+ pub fn eval_default_body_stability(self, def_id: DefId, span: Span) -> EvalResult {
+ let is_staged_api = self.lookup_stability(def_id.krate.as_def_id()).is_some();
+ if !is_staged_api {
+ return EvalResult::Allow;
+ }
+
+ let stability = self.lookup_default_body_stability(def_id);
+ debug!(
+ "body stability: inspecting def_id={def_id:?} span={span:?} of stability={stability:?}"
+ );
+
+ // Only the cross-crate scenario matters when checking unstable APIs
+ let cross_crate = !def_id.is_local();
+ if !cross_crate {
+ return EvalResult::Allow;
+ }
+
+ // Issue #38412: private items lack stability markers.
+ if skip_stability_check_due_to_privacy(self, def_id) {
+ return EvalResult::Allow;
+ }
+
+ match stability {
+ Some(DefaultBodyStability {
+ level: attr::Unstable { reason, issue, is_soft, .. },
+ feature,
+ }) => {
+ if span.allows_unstable(feature) {
+ debug!("body stability: skipping span={:?} since it is internal", span);
+ return EvalResult::Allow;
+ }
+ if self.features().active(feature) {
+ return EvalResult::Allow;
+ }
+
+ //let suggestion = suggestion_for_allocator_api(self, def_id, span, feature);
+ EvalResult::Deny {
+ feature,
+ reason: reason.to_opt_reason(),
+ issue,
+ suggestion: None,
+ is_soft,
+ }
+ }
+ Some(_) => {
+ // Stable APIs are always ok to call
+ EvalResult::Allow
+ }
+ None => EvalResult::Unmarked,
+ }
+ }
+