Re: [PATCH] ci: add job for gcc-4.8 to GitHub Actions

From: Jeff King <peff@peff.net>
Date: Aug 17, 2021, 15:15 UTC
Message-ID: <YRvSoGodEJB26twE@coredump.intra.peff.net>
In-Reply-To: <20210817111512.GA2257957@szeder.dev>

On Tue, Aug 17, 2021 at 01:15:12PM +0200, SZEDER Gábor wrote:

Show 14 quoted lines

> > Try fb9d7431cf (travis-ci: build with GCC 4.8 as well, 2019-07-18).
> > (found with "git log -Sgcc-4.8 ci"). The gist of it is to find variable
> > declarations in for-loops.
> > 
> > IMHO it may be more trouble than it's worth. If we can't find a compiler
> > that complains on this construct, then maybe it is not a construct worth
> > worrying too much about.
> 
> I for one like for loop initial declarations, because they allow us to
> limit the scope of the loop variable to the loop, and would love to
> see it used in more places (well, wherever possible, actually, but
> that'd be a lot of churn).  So I would prefer to just drop this job
> sooner rather than later, update CodingGuidelines, and, if deemed
> necessary, launch a weather balloon.

Yeah, I think it would be nice to use that, too, if it works everywhere. The last discussion of this was from 2017, where peple likewise seemed in favor:

  https://lore.kernel.org/git/xmqqlgnrq9qi.fsf@gitster.mtv.corp.google.com/

There was even a weather balloon patch:

  https://lore.kernel.org/git/20170719181956.15845-1-sbeller@google.com/

but it got hung up on somebody using gcc 4.8. ;)

It looks like the default flavor bumped to gnu90 in gcc 5. That came out in 2015, but the last 4.x release was in August 2016. Which is getting old-ish, but still well within the realm of what people may be using an on older distro (e.g., RHEL7, which is still supported).

For gcc, at least, this is trivially fixable with a `-std` flag (though it may be tricky to make it work out-of-the-box through the Makefile). I don't think we'll know if there problems with other compilers until we do the weather balloon.

-Peff