src/HOL/Tools/datatype_codegen.ML

         val thm' = singleton (ProofContext.export lthy' ctxt_thy) thm;
       in (thm', lthy') end;
     fun tac thms = Class.intro_classes_tac []
       THEN ALLGOALS (ProofContext.fact_tac thms);
     fun get_eq' thy dtco = get_eq thy dtco
-      |> map (CodeUnit.constrain_thm [HOLogic.class_eq])
+      |> map (Code_Unit.constrain_thm [HOLogic.class_eq])
       |> map Simpdata.mk_eq
       |> map (MetaSimplifier.rewrite_rule [Thm.transfer thy @{thm equals_eq}]);
     fun add_eq_thms dtco thy =
       let
         val thy_ref = Theory.check_thy thy;