1 files changed, 13 insertions, 2 deletions
diff --git a/compiler/rustc_resolve/src/def_collector.rs b/compiler/rustc_resolve/src/def_collector.rs
index a4fdb4a0baf..1fb942de734 100644
--- a/compiler/rustc_resolve/src/def_collector.rs
+++ b/compiler/rustc_resolve/src/def_collector.rs
@@ -312,8 +312,19 @@ impl<'a, 'b, 'tcx> visit::Visitor<'a> for DefCollector<'a, 'b, 'tcx> {
     }
 
     fn visit_anon_const(&mut self, constant: &'a AnonConst) {
-        let def = self.create_def(constant.id, kw::Empty, DefKind::AnonConst, constant.value.span);
-        self.with_parent(def, |this| visit::walk_anon_const(this, constant));
+        // HACK(min_generic_const_args): don't create defs for anon consts if we think they will
+        // later be turned into ConstArgKind::Path's. because this is before resolve is done, we
+        // may accidentally identify a construction of a unit struct as a param and not create a
+        // def. we'll then create a def later in ast lowering in this case. the parent of nested
+        // items will be messed up, but that's ok because there can't be any if we're just looking
+        // for bare idents.
+        if constant.value.is_potential_trivial_const_arg() {
+            visit::walk_anon_const(self, constant)
+        } else {
+            let def =
+                self.create_def(constant.id, kw::Empty, DefKind::AnonConst, constant.value.span);
+            self.with_parent(def, |this| visit::walk_anon_const(this, constant));
+        }
     }
 
     fn visit_expr(&mut self, expr: &'a Expr) {