From: Jonathan Nieder Date: Mon, 24 Nov 2014 17:59:47 GMT Subject: Re: [PATCH RFC] CYGWIN: avoid implicit declaration warning Message-ID: <20141124175947.GN6527@google.com> In-Reply-To: <5471EC26.3040705@web.de> 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 > Signed-off-by: Torsten Bögershausen > --- > 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