On Thu, 18 Jul 2013 09:47:02 +0200 "Yann E. MORIN" [off-list ref] wrote:

quoted

I prefer the "option exec" approach, actually.  That way the shell-outs
are colocated with the code which uses

Indeed, but in this case, all the checks will be spread-out in the Kconfig
files, and not easily locatable. Having all in a single script will also
more easily raise eyebrows when that script appears in a diffstat. Noticing
the 'exec' option risks being a bit less easy.

Eh, there are a million ways to screw up the kernel.

But, that's not my call to decide. ;-)

quoted

them and they will only be executed
if you've actually selected that subsystem for building (I think?).

If I understand the code correctly (which is still to be proven), the
exec option is run at parse-time, once.

Yes, but not every Kconfig file in the tree gets parsed every time. 
For example, if arch/arm/Kconfig uses "option exec=some-slow-thing",
x86 users won't execute some-slow-thing.  This is good.