thingy.py

from cffi import FFI

def compile_stat_ffi_with_cdef(name, cdef):
    ffi = FFI()
    ffi.set_source(
        name, """
#include <sys/stat.h>
    """)
    ffi.cdef(cdef)
    print("compiled to", ffi.compile())

compile_stat_ffi_with_cdef("ffi1", """
struct stat {
	unsigned long	st_dev;
	...;
};
""")
compile_stat_ffi_with_cdef("ffi2", """
struct stat {
	unsigned short	st_dev;
	...;
};
""")