Re: [PATCH v2 1/2] format-patch: Add a config option format.from to set the default for --from

From: Jeff King <peff@peff.net>
Date: Aug 8, 2016, 05:06 UTC
Message-ID: <20160808050614.pirm3qnizrbzbsh4@sigill.intra.peff.net>
In-Reply-To: <20160808050217.u2pmbu7b7yww4viv@x>

On Sun, Aug 07, 2016 at 07:02:18PM -1000, Josh Triplett wrote:

Show 9 quoted lines

> > Portability; some compilers choke on it. C89 allows trailing commas in
> > array initialization but _not_ in enums. Most compilers allow it anyway
> > (though gcc complains with -Wpedantic).
> > 
> > This definitely broke the build on real systems early in Git's history
> > (I think the AIX compiler was one culprit),
> 
> Thanks for the explanation.  I assume such compilers also don't accept
> C99?

Correct. We don't allow other C99 features like variadic macros, either (there are some in the code base, but you'll note they can all be conditionally disabled).

> Perhaps the next Git user survey could ask "what compiler (including
> version) do you use to compile Git", and perhaps "does it accept the
> following code:"?

Maybe. I'm not sure I would consider a lack of responses there to be a definite sign. It seems that once every few years people on bizarre systems come out of the woodwork and do a round of portability fixes, and then problems accrue, and so on. So I'm not sure that the survey would hit the right people in a timely manner.

I think the breaking point will be just declaring "look, C99 is N years old; if your compiler can't handle it, that's now your problem". When Git started, N was only 6. It's now 17.

-Peff