[cfe-dev] Using CMake/Ninja on buildbots

[Renato Golin]

On 6 February 2013 22:13, Arnaud de Grandmaison <arnaud.adegm at gmail.com>wrote:

> **
>
> I think we just need to increase coverage. Everything you can do to build
> (even slightly) differently than other bots is good to have.
>

Hi Arnaud,

I agree building with { CMake, autoconf } x { Cold, Warm } will catch more
corner cases than defaulting all builds to the same standard, however,
relying on patchy distribution to achieve that is naive. Also, we don't
need to catch build corner cases on every commit...

A standard build system for buildbots and developers is beneficial because
you don't need to run around to fix bugs specific to a build system that is
not often used. The fact that people wanted to remove the MBlaze back-end
today is for that very reason. Generic changes on other parts demand
specific changes on a part of the code that is not used often.

That said, it is possible that some of the options we have with autoconf
are not available on a CMake build (I'm guessing here), and thus
deprecating autoconf entirely is not an option right now. If the reason is
strong enough to keep autoconf for the foreseeable future, than we do need
coverage.

But coverage means running both CMake and autoconf, both warm and cold, on
each variant that we care about. So, if that would be true, I'd have to
have at least 4 buildbot configurations for every ARM platform I care
about. For now, I care about A9 and A15, so I'd have to have at least 8
bots. How much of that I can ignore depends on my interest on them,
availability of hardware, etc.

Thinking that I can get away and have { warm+autoconf on A9 } + {
cold+ninja on A15 } and saving 6 bots is naive, at best. However, having {
warm+ninja } on both and, during weekends doing one of each { warm+autoconf
}, { cold+ninja } and { cold+autoconf } on the same commit, then continuing
with the bot schedule, would at least give you a uniform, but not precise,
view of the build system failures. The three additional builds will rarely
give you real code errors, so it's ok to be only once a week.

I don't believe Buildbot is capable of such strategy, though. Galina may
know of a way of doing this... But I'm ok with just running { warm+ninja }
for the foreseeable future...

cheers,
--renato
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