+
+ if interior_or_upvar_span.is_none() && generator_data.is_foreign() {
+ interior_or_upvar_span = Some(GeneratorInteriorOrUpvar::Interior(*span, None));
+ }
+ } else if self.tcx.sess.opts.unstable_opts.drop_tracking_mir
+ // Avoid disclosing internal information to downstream crates.
+ && generator_did.is_local()
+ // Try to avoid cycles.
+ && !generator_within_in_progress_typeck
+ {
+ let generator_info = &self.tcx.mir_generator_witnesses(generator_did);
+ debug!(?generator_info);
+
+ 'find_source: for (variant, source_info) in
+ generator_info.variant_fields.iter().zip(&generator_info.variant_source_info)
+ {
+ debug!(?variant);
+ for &local in variant {
+ let decl = &generator_info.field_tys[local];
+ debug!(?decl);
+ if ty_matches(ty::Binder::dummy(decl.ty)) && !decl.ignore_for_traits {
+ interior_or_upvar_span = Some(GeneratorInteriorOrUpvar::Interior(
+ decl.source_info.span,
+ Some((None, source_info.span, None, from_awaited_ty)),
+ ));
+ break 'find_source;
+ }
+ }
+ }