Re: latest list of unused Kconfig variables

[Josh Boyer <jwboyer@gmail.com>]

On Wed, 13 Feb 2008 10:07:27 -0500 (EST)
"Robert P. J. Day" <rpjday@crashcourse.ca> wrote:

> On Wed, 13 Feb 2008, Josh Boyer wrote:
> 
> > On Wed, 13 Feb 2008 03:56:34 -0500 (EST)
> > "Robert P. J. Day" <rpjday@crashcourse.ca> wrote:
> 
> > >   now that 2.6.25-rc1 is out, i can start updating the output from
> > > my scanning scripts.  the first updated output is the list of
> > > currently unused Kconfig variables -- variables that are defined
> > > in some Kconfig file somewhere but appear to be entirely unused
> > > throughout the source tree.
> > >
> > >   latest output here, sorted by architecture:
> > >
> > > http://www.crashcourse.ca/wiki/index.php/Unused_CONFIG_variables
> > >
> > > as always, there will probably be some false positives for one
> > > reason or another.
> > >
> > >   output from the other scanning scripts will be up in short order.
> >
> > You have lots of false positives (or something) for arch/powerpc.
> > Seems your script picked up #define names and comments that happen
> > to match a Kconfig variable?
> 
> it always will, given the proclivity of some folks to define their own
> variables with a "CONFIG_" prefix.  as i point out on the wiki page, i
> make no attempt to cull that list, i just print it as is, and readers
> will have to peruse the list carefully to see what's meaningful and
> what isn't.

OK.  Well all of your hits for 405EX, 440GRX, 440SPe, and
WANT_DEVICE_TREE in arch/powerpc seem bogus.  I dunno if you prune
those when reported or not.

> > And you have false positives on several CPU variables, as they are
> > used within Kconfig files themselves to select different sets of
> > options.
> 
> yes, i know ... perhaps there's a simple way to filter those out but,
> at the moment, it's pure brute force.  i'm guessing i could make that
> script a bit smarter but it probably isn't worth the investment in
> time.  law of diminishing returns and all that.

Maybe.  If the same false positives keep showing up people might ignore
it.  I won't, but others might.

> > For arch/ppc, the WANT_EARLY_SERIAL stuff was added by Al to fix those
> > boards that unconditionally called early_serial_setup by selecting
> > SERIAL_8250 in commit f08243a491f3e21feabbb04476a03fb0cbc975ff.  Al,
> > couldn't we just select SERIAL_8250 right in the board config
> > instead?
> >
> > Of course, arch/ppc is dying soon-ish anyway so we might not even
> > bother.
> 
> if that's the case, i can just stop scanning that entire directory.

It's going away in June, per feature-removal-schedule.  I will still fix
actual bugs until then, but not much else.

josh