No #ifdef in .c files - example


Before:
drivers/usb/hid_core.c

 static void hid_process_event (struct hid_device *hid, struct hid_field *field,
                                   struct hid_usage *usage, __s32 value)
 {
         hid_dump_input(usage, value); 
         if (hid->claimed & HID_CLAIMED_INPUT)
                 hidinput_hid_event(hid, field, usage, value);
 #ifdef CONFIG_USB_HIDDEV
         if (hid->claimed & HID_CLAIMED_HIDDEV)
                 hiddev_hid_event(hid, usage->hid, value);
 #endif
 }