Re: [PATCH] kconfig: warn about complex selects

[Ingo Molnar <mingo@elte.hu>]

* Sam Ravnborg <sam@ravnborg.org> wrote:

> On Sun, May 04, 2008 at 07:40:44AM +0200, Vegard Nossum wrote:
> > Hi,
> > 
> > Given recent discussion about kconfig and the "select" feature, I have made
> > the following quick & dirty patch to detect what I call "complex selects".
> > 
> > For v2.6.25, I get these warnings:
> > sound/pci/Kconfig:512:error: found complex select: SND_FM801_TEA575X -> VIDEO_V4L1
> > drivers/ide/Kconfig:890:error: found complex select: ETRAX_IDE -> BLK_DEV_IDEDMA
> > drivers/acpi/Kconfig:185:error: found complex select: ACPI_HOTPLUG_CPU -> ACPI_CONTAINER
> > 
> > While for v2.6.26-rc1, I get these:
> > sound/pci/Kconfig:528:error: found complex select: SND_FM801_TEA575X -> VIDEO_V4L1
> > drivers/media/video/em28xx/Kconfig:2:error: found complex select: VIDEO_EM28XX -> MEDIA_TUNER
> > drivers/media/video/bt8xx/Kconfig:2:error: found complex select: VIDEO_BT848 -> MEDIA_TUNER
> > drivers/media/video/saa7134/Kconfig:2:error: found complex select: VIDEO_SAA7134 -> MEDIA_TUNER
> > drivers/media/video/cx88/Kconfig:2:error: found complex select: VIDEO_CX88 -> MEDIA_TUNER
> > drivers/media/video/cx23885/Kconfig:2:error: found complex select: VIDEO_CX23885 -> MEDIA_TUNER
> > drivers/media/video/ivtv/Kconfig:2:error: found complex select: VIDEO_IVTV -> MEDIA_TUNER
> > drivers/media/video/cx18/Kconfig:2:error: found complex select: VIDEO_CX18 -> MEDIA_TUNER
> > drivers/media/video/pvrusb2/Kconfig:2:error: found complex select: VIDEO_PVRUSB2 -> MEDIA_TUNER
> > drivers/media/video/Kconfig:690:error: found complex select: VIDEO_MXB -> MEDIA_TUNER
> > drivers/media/video/usbvision/Kconfig:2:error: found complex select: VIDEO_USBVISION -> MEDIA_TUNER
> > drivers/acpi/Kconfig:188:error: found complex select: ACPI_HOTPLUG_CPU -> ACPI_CONTAINER
> > 
> > (In other words, the number of these has increased significantly since the
> > last release, and these will probably be hit as compile errors at one point
> > or another.)
> > 
> > I am not a kconfig expert, so I might have missed some things. Roman, is this
> > even remotely good? I think it's probably a good start anyway.
> 
> I did a small test of this using following configuration:
> config A
>         bool "a"
> 
> config B
>         bool "b"
>         depends on A
>         default AA || AAA
> 
> config BB
>         bool "bb"
>         depends on A
> 
> config C
>         bool "c"
>         select B
> 
> config CC
>         bool "cc"
>         select BB
> 
> 
> I had expected a warning about complex select for both C and CC. But 
> only C triggered the warning due to the complex default value of B. So 
> we need to work on this a bit more.
> 
> But great to see code instead of just talking!

agreed, very cool stuff Vegard! :)

	Ingo