Failed build on randconfig for DVB_DIB modules
From: Steven Rostedt
Date: Tue Oct 26 2010 - 00:16:47 EST
I'm currently finishing up an automated test program (that I will be
publishing shortly). This program does various randconfig builds, boots
and tests (as well as bisecting and patch set testing). But enough about
it.
I hit this little build bug that is more annoying than anything else. If
I have the following configuration:
CONFIG_DVB_USB_DIBUSB_MB=y
CONFIG_DVB_USB_DIBUSB_MC=m
CONFIG_DVB_USB_NOVA_T_USB2=m
It fails to build with this error:
ERROR: "dibusb_dib3000mc_frontend_attach" [drivers/media/dvb/dvb-usb/dvb-usb-nova-t-usb2.ko] undefined!
ERROR: "dibusb_dib3000mc_tuner_attach" [drivers/media/dvb/dvb-usb/dvb-usb-nova-t-usb2.ko] undefined!
ERROR: "dibusb_dib3000mc_frontend_attach" [drivers/media/dvb/dvb-usb/dvb-usb-dibusb-mc.ko] undefined!
ERROR: "dibusb_dib3000mc_tuner_attach" [drivers/media/dvb/dvb-usb/dvb-usb-dibusb-mc.ko] undefined!
Those undefined functions are defined in
drivers/media/dvb/dvb-usb/dibusb-common.c, but are surrounded by:
#if defined(CONFIG_DVB_DIB3000MC) || \
(defined(CONFIG_DVB_DIB3000MC_MODULE) && defined(MODULE))
Which Mauro updated in Dec 2007 with this commit:
4a56087f3b7660c9824e9ec69b96ccf8d9b25d1c
due to just having CONFIG_DVB_DIB3000MC not enough.
Well, this is not enough either. Why?
On build the object dibusb-common.o is built first because of the
DVB_USB_DIBUSB_MB being builtin kernel core. Thus, it gets built with
the preprocessor condition false.
Then when the compile gets to the modules, the object dibusb-common.o
has already been built, and gets linked in as is.
We end up with the functions not defined and we get the above error.
My question: Why does that preprocessor condition exist? Can't we just
build those functions in regardless?
-- Steve
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