Re: [PATCH] xen/Makefile: drop -Werror

[Jan Beulich <jbeulich@xxxxxxxx>]

On 02.07.2021 20:52, Elliott Mitchell wrote:
> On Fri, Jul 02, 2021 at 07:51:55PM +0200, Fabrice Fontaine wrote:
>>
>> I do agree that setting -Werror is generally perfectly valid for upstream.
>> However, for downstream packager, it is generally seen as an issue as
>> it will always raise unexepected build failures with older, newer, or
>> exotic toolchains, see
>> https://embeddedartistry.com/blog/2017/05/22/werror-is-not-your-friend.
>> It would be good to, at least, have an option to disable -Werror for
>> example through a XEN_DISABLE_WERROR.
> 
> Two people don't make it a majority opinion, but if this was a meeting
> this opinion would get a second.
> 
> I don't know where everyone is on the spectrum, but I also strongly
> dislike -Werror yet do like -Wall and tend to get rid of warnings.
> -Werror is good for continuous integration systems, not so great for
> releases or active development.

Well, my experience with Linux (when I started working there alongside
working on Xen, many years ago) was that many people don't care at all
about compiler warnings their code changes introduce. While Linux has
improved some, I'm still carrying a fair size patch to silence all the
warnings that I observe on various build systems (i.e. with various
compiler versions). I do this because in a build with (perhaps many)
pre-existing warnings it is far easier to miss the one you accidentally
introduce with some code change. -Werror is an imo very appropriate
measure to get people to at least address the warnings they can easily
observe about everywhere. IOW I've always been appreciating Xen being
different from Linux in this regard.

Jan