Re: [dpdk-dev] [PATCH] Make -Werror optional

[Neil Horman <nhorman@tuxdriver.com>]

On Mon, Feb 23, 2015 at 10:19:23AM +0200, Panu Matilainen wrote:
> On 02/21/2015 09:33 PM, Neil Horman wrote:
> >On Fri, Feb 20, 2015 at 05:55:21PM -0800, Stephen Hemminger wrote:
> >>On Thu, 12 Feb 2015 16:54:44 +0200
> >>Panu Matilainen <pmatilai@redhat.com> wrote:
> >>
> >>>On 02/12/2015 04:38 PM, Stephen Hemminger wrote:
> >>>>On Thu, 12 Feb 2015 13:13:22 +0200
> >>>>Panu Matilainen <pmatilai@redhat.com> wrote:
> >>>>
> >>>>>This adds new CONFIG_RTE_ERROR_ON_WARNING config option to enable
> >>>>>fail-on-warning compile behavior, defaulting to off.
> >>>>>
> >>>>>Failing build on warnings is a useful developer tool but its bad
> >>>>>for release tarballs which can and do get built with newer
> >>>>>compilers than what was used/available during development. Compilers
> >>>>>routinely add new warnings so code which built silently with cc X
> >>>>>might no longer do so with X+1. This doesn't make the existing code
> >>>>>any more buggier and failing the build in this case does not help
> >>>>>not help improve code quality of an already released version either.
> >>
> >>Hopefully distro's like RHEL will build with -Werror enabled
> >>and not allow build to go through with errors.
> >>
> >Thats usually what we do, yes.
> 
> Um, nope. All Fedora and RHEL builds are done using a common base set of
> flags set centrally from rpm configuration, and that includes among other
> things -Wall but not -Werror, although since F21 -Werror=format-security is
> included since that there are relatively few false positives for that.
> 
> The thing is, compiler warnings from compilers are just that: warnings, and
> often including hefty dose of false positives. A good package maintainer
> will look at the build logs of his/her packages, investigate warnings and
> send patches upstream to address them in oncoming versions where actually
> relevant, but generally a package maintainer in a distro is not responsible
> for achieving zero-warning build, nor should they.
> 
Um, I don't know what you've been doing, but most of my packages typically have
zero warnings.  Its true package maintainers have the option to disable
warnings, and many do for pragmatic reasons as you note, but when its feasible,
theres no reason not to make sure warning doesn't get raised when you expect
there to be none.

Neil