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

From: Jonathan Nieder <[email-masked]>
Date: Mon, 24 Nov 2014 09:59:47 -0800

Torsten Bögershausen wrote:

> 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 <[email-masked]>
> Signed-off-by: Torsten Bögershausen <[email-masked]>
> ---
> 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