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

[Panu Matilainen <pmatilai@redhat.com>]

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.

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 -