Re: [PATCH v2 1/1] git-compat-util: add a test balloon for C99 support

[Carlo Arenas <carenas@gmail.com>]

On Wed, Nov 17, 2021 at 3:18 PM brian m. carlson
<sandals@crustytoothpaste.net> wrote:
>
> On 2021-11-17 at 03:01:57, Jeff King wrote:
> > My thinking was that breaking older compilers was preferable to breaking
> > non-gnu ones, because at least old ones go away eventually. But your
> > other email makes me wonder if those non-GNU ones may already be
> > overriding CFLAGS.
>
> Our only problem platform, as far as I can tell, is RHEL/CentOS 7.  That
> uses GCC 4.8, and even Ubuntu 18.04 ships with GCC 7.

There are several odd BSD platforms that are still stuck in pre-GPLv3
gcc (AKA gcc 4.2.1) like OpenBSD Alpha, hppa, landisk (and maybe also
SPARC64 which is tier1) and that will need the same, there is indeed
also luna88k that uses an even older gcc but hopefully will be able to
work if it understands enough C99 and can be told to use it by this
flag.

> > Still, if we can come up with a solution that breaks neither (with some
> > light auto-detection or heuristics in the Makefile), that could be the
> > best of both worlds.
>
> I can move COMPILER_FEATURES out of config.mak.dev and into Makefile so
> that we can make use of it.  We'll need to depend on GCC 6 for this
> because we lack a way to distinguish 5.1 (which should work) from 5.0
> (which will not).

5.0 works AFAIK, is anything older than 5 than does not as reported[1]
before, but it won't be still a good fit, since it only works for gcc
and clang AS-IS.

Carlo

[1] https://lore.kernel.org/git/CAPUEsphnCvK+RZ+h30ZarA1zo9yZ=ndEBrcAbKGf4W92j647vA@mail.gmail.com/