On Tue, Oct 6, 2020 at 6:08 AM Andrew Lunn <andrew@xxxxxxx> wrote:
>
> > It depends a lot on what portion of the kernel gets enabled for W=1.
> >
> > As long as it's only drivers that are actively maintained, and they
> > make up a fairly small portion of all code, it should not be a problem
> > to find someone to fix useful warnings.
>
> Well, drivers/net/ethernet is around 1.5M LOC. The tree as a whole is
> just short of 23M LOC. So i guess that is a small portion of all the
> code.
>
> Andrew
I am not a big fan of KBUILD_CFLAGS_W1_<timestamp>
since it is ugly.
I'd like to start with adding individual flags
like drivers/gpu/drm/i915/Makefile, and see
how difficult it would be to maintain it.
One drawback of your approach is that
you cannot set KBUILD_CFLAGS_W1_20200930
until you eliminate all the warnings in the
sub-directory in interest.
(i.e. all or nothing approach)
At best, you can only work out from 'old -> new' order
because KBUILD_CFLAGS_W1_20200326 is a suer-set of
KBUILD_CFLAGS_W1_20190907, which is a suer-set of
KBUILD_CFLAGS_W1_20190617 ...
If you add flags individually, you can start with
low-hanging fruits, or ones with higher priority
as Arnd mentions about -Wmissing-{declaration,prototypes}.
For example, you might be able to set
'subdir-ccflags-y += -Wmissing-declarations'
to drivers/net/Makefile, while
'subdir-ccflags-y += -Wunused-but-set-variable'
stays in drivers/net/ethernet/Makefile.
--
Best Regards
Masahiro Yamada
