Re: Build regressions/improvements in v4.6-rc1

[Dave Chinner]

On Sun, Mar 27, 2016 at 02:43:24PM +0200, Geert Uytterhoeven wrote:
> On Sun, Mar 27, 2016 at 2:39 PM, Geert Uytterhoeven
> <geert@xxxxxxxxxxxxxx> wrote:
> > Below is the list of build error/warning regressions/improvements in
> > v4.6-rc1[1] compared to v4.5[2].
> >
> > Summarized:
> >   - build errors: +9/-6
> 
> > [1] http://kisskb.ellerman.id.au/kisskb/head/10114/ (all 262 configs)
> > [2] http://kisskb.ellerman.id.au/kisskb/head/10047/ (all 262 configs)
> 
> > 9 error regressions:
> >   + /home/kisskb/slave/src/fs/xfs/xfs_ondisk.h: error: call to
> > '__compiletime_assert_79' declared with attribute error: XFS:
> > sizeof(xfs_attr_shortform_t) is wrong, expected 8:  => 79:2
> 
> cris-allyesconfig, cris-allmodconfig

Yup, cris is the only platform that throws this error on this
structure. It's an on-disk structure and relying on the gcc
optimiser to do the same thing from release to release has become
such a crap-shoot these days. Hence as a stop-gap measure we added
build time checking of what they compiler is doing with those
structures, and to refuse to build XFS if the compiler/platform is
doing something obviously different.

Modernising the on-disk structure definitions is on the list of
things to do, but it's nowhere near the top of my list at the
moment...

Cheers,

Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx