Re: [PATCH RFC] CYGWIN: avoid implicit declaration warning

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Nov 24, 2014, 17:59 UTC
Message-ID: <20141124175947.GN6527@google.com>
In-Reply-To: <5471EC26.3040705@web.de>

Torsten Bögershausen wrote:

Show 15 quoted lines

> gcc under cygwin reports several warnings like this:
>
>  warning: implicit declaration of function 'memmem'
>   [-Wimplicit-function-declaration]
>
> This has been observed under CYGWIN-32 with GCC 4.7.3 as well
> as CYGWIN-64 with gcc v4.8.3-5 x86-64
>
> Do not #define _XOPEN_SOURCE 600 for CYGWIN.
>
> Reported-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
> Signed-off-by: Torsten Bögershausen <tboegi@web.de>
> ---
> This may be a start for a patch, tested under CYGWIN-32,
> both Windows7 and XP

The "tested under" part would also be a good addition to the commit message.

>  git-compat-util.h | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Patch looks good to me. Do you know if this has been reported to the Cygwin maintainers? The behavior seems counterintuitive --- I would expect _GNU_SOURCE to override everything else (since I thought that was the point of _GNU_SOURCE).

Thanks, Jonathan