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

> Hi Junio & brian,
>
> On Wed, 17 Nov 2021, Junio C Hamano wrote:
>
>> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
>>
>> >> Even MSVC, long a holdout against modern C, now supports both C11 and
>> >> C17 with an appropriate update.  Moreover, even if people are using an
>> >> older version of MSVC on these systems, they will generally need some
>> >> implementation of the standard Unix utilities for the testsuite, and GNU
>> >> coreutils, the most common option, has required C99 since 2009.
>> >> Therefore, we can safely assume that a suitable version of GCC or clang
>> >> is available to users even if their version of MSVC is not sufficiently
>> >> capable.
>> >
>> > I am all in favor of this patch!
>>
>> I like the direction, but ...
>>
>> >> diff --git a/Makefile b/Makefile
>> >> index 12be39ac49..22d9e67542 100644
>> >> --- a/Makefile
>> >> +++ b/Makefile
>> >> @@ -1204,7 +1204,7 @@ endif
>> >>  # Set CFLAGS, LDFLAGS and other *FLAGS variables. These might be
>> >>  # tweaked by config.* below as well as the command-line, both of
>> >>  # which'll override these defaults.
>> >> -CFLAGS = -g -O2 -Wall
>> >> +CFLAGS = -g -O2 -Wall -std=gnu99
>>
>> ... as has been already pointed out, this part probably should not
>> be there.  It is not our intention to require gcc/clang, or to
>> constrain newer systems to gnu99.
>
> Another data point in favor of dropping this: our FreeBSD CI build reports
> a compile error with this:
>
> 	[...]
> 	archive.c:337:35: error: '_Generic' is a C11 extension
> 	[-Werror,-Wc11-extensions]
> 			strbuf_addstr(&path_in_archive, basename(path));
> 							^
> 	/usr/include/libgen.h:61:21: note: expanded from macro 'basename'
> 	#define basename(x)     __generic(x, const char *, __old_basename, basename)(x)
> 				^
> 	/usr/include/sys/cdefs.h:329:2: note: expanded from macro '__generic'
> 		_Generic(expr, t: yes, default: no)
> 		^
> 	1 error generated.
>
> I verified in https://github.com/gitgitgadget/git/pull/1082 that this
> patch is indeed the cause of this compile error.