foo.h

#define globus_i_ftp_control_debug(Level)                   \
    (globus_i_ftp_control_debug_level >= (Level))

#define globus_i_ftp_control_debug_extract_message(stream, ...) __VA_ARGS__

#define globus_i_ftp_control_debug_printf(level, message)   \
do {                                                        \
    if (globus_i_ftp_control_debug(level))                  \
    {                                                       \
        globus_libc_fprintf(debug_handle, globus_i_ftp_control_debug_extract_message message)
    }                                                       \
} while (0)


globus_i_ftp_control_debug_printf(42, (stderr, "hello: %s\n", world));