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

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Feb 12, 2015 at 02:02:19PM +0200, Panu Matilainen wrote:
> On 02/12/2015 01:25 PM, Bruce Richardson wrote:
> >On Thu, Feb 12, 2015 at 01:13:22PM +0200, Panu Matilainen 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.
> >
> >This can already be achieve by passing EXTRA_CFLAGS='-Wno-error' into the
> >build command. I don't like changing the default option here. Better to
> >instead document how to disable the warning flags if necessary.
> 
> Well, optimally it would only default to off in released versions, which is
> where the Werror behavior is just annoying without being useful.

This I can agree with.

/Bruce

> 
> For a practical example of how silly this can be: just got a build failure
> with 1.8 due to "variable set but not used" warnings, because gcc 5 is
> "smarter" and finds couple of cases older versions did not.
> So everybody using gcc 5 to build the just-released 1.8 will be required to
> hunt down and pass in that extra disabler, for no good reason.
> 
> 	- Panu -
>