dune

(executable
 (name gen_types_c)
 (modules gen_types_c)
 (libraries sys-socket.types ctypes.stubs))

(rule
 (targets gen_types.c)
 (deps    (:gen ./gen_types_c.exe))
 (action  (run %{gen} %{targets})))

(rule
 (targets gen_types_c)
 (deps    (:c_code ./gen_types.c))
 (action  (run %{ocaml-config:c_compiler} -I %{lib:ctypes:} -I %{ocaml-config:standard_library} -o %{targets} %{c_code})))