pub async fn implementation coroutine (func::{closure#0}) is monomorphized, when func itself is monomorphized

1 files changed, 14 insertions, 1 deletions

diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 6a836442c32..cffeb6f9807 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -1535,7 +1535,20 @@ impl<'v> RootCollector<'_, 'v> {
     fn process_nested_body(&mut self, def_id: LocalDefId) {
         match self.tcx.def_kind(def_id) {
             DefKind::Closure => {
-                if self.strategy == MonoItemCollectionStrategy::Eager
+                // for 'pub async fn foo(..)' also trying to monomorphize foo::{closure}
+                let is_pub_fn_coroutine =
+                    match *self.tcx.type_of(def_id).instantiate_identity().kind() {
+                        ty::Coroutine(cor_id, _args) => {
+                            let tcx = self.tcx;
+                            let parent_id = tcx.parent(cor_id);
+                            tcx.def_kind(parent_id) == DefKind::Fn
+                                && tcx.asyncness(parent_id).is_async()
+                                && tcx.visibility(parent_id).is_public()
+                        }
+                        ty::Closure(..) | ty::CoroutineClosure(..) => false,
+                        _ => unreachable!(),
+                    };
+                if (self.strategy == MonoItemCollectionStrategy::Eager || is_pub_fn_coroutine)
                     && !self
                         .tcx
                         .generics_of(self.tcx.typeck_root_def_id(def_id.to_def_id()))