Re: xfsprogs compile warnings: _BSD_SOURCE is deprecated in glibc 2.20.

Jan Tulak
2015-04-29T08:23:27Z

----- Original Message -----
> From: "Dave Chinner" <david@fromorbit.com>
> To: "Jan Ťulák" <jtulak@redhat.com>
> Cc: xfs@oss.sgi.com
> Sent: Tuesday, 28 April, 2015 11:12:59 PM
> Subject: Re: xfsprogs compile warnings: _BSD_SOURCE is deprecated in glibc 2.20.
>
> On Tue, Apr 28, 2015 at 01:09:04PM +0200, Jan Ťulák wrote:
> > In glibc 2.20, _BSD_SOURCE and _SVID_SOURCE were deprecated and should be
> > replaced with _DEFAULT_SOURCE. Currently, compiling xfsprogs on a system
> > with
> > glibc in said or newer version (like current Fedora) produces tons of
> > warnings
> > like this one:
> >
> > In file included from /usr/include/stdio.h:27:0,
> > from ../include/xfs/platform_defs.h:24,
> > from ../include/xfs/libxfs.h:25,
> > from xfs_mkfs.c:19:
> > /usr/include/features.h:148:3: warning: #warning "_BSD_SOURCE and
> > _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE" [-Wcpp]
> > # warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use
> > _DEFAULT_SOURCE"
> >
> > It can be fixed with the single line patch bellow, but I'm not sure if we
> > can
> > remove the deprecated version because of compatiblity. Glibc 2.19, which
> > added
> > _DEFAULT_SOURCE, was released in 2014, and I'm not sure how much it is
> > backported and how much xfsprogs are backported too. So, do we need a
> > better
> > patch to take care of this and provide differend _SOURCE based on glibc
> > version, or this patch is enough?
> >
> > Source: man 7 feature_test_macros
> > Here is a link in case you older version:
> > http://man7.org/linux/man-pages/man7/feature_test_macros.7.html
>
> /me smacks head against wall
>
> Really? glibc has decided to break the build of half the world?
>
> > Signed-off-by: Jan Ťulák <jtulak@redhat.com>
> > ---
> > include/builddefs.in | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/include/builddefs.in b/include/builddefs.in
> > index 944bcf6..6e6097a 100644
> > --- a/include/builddefs.in
> > +++ b/include/builddefs.in
> > @@ -109,7 +109,7 @@ GCCFLAGS = -funsigned-char -fno-strict-aliasing -Wall
> > # -Wbitwise -Wno-transparent-union -Wno-old-initializer -Wno-decl
> >
> > ifeq ($(PKG_PLATFORM),linux)
> > -PCFLAGS = -D_GNU_SOURCE -D_BSD_SOURCE -D_XOPEN_SOURCE=500
> > -D_FILE_OFFSET_BITS=64 $(GCCFLAGS)
> > +PCFLAGS = -D_GNU_SOURCE -D_DEFAULT_SOURCE -D_XOPEN_SOURCE=500
> > -D_FILE_OFFSET_BITS=64 $(GCCFLAGS)
>
> Quoting that man page:
>
> "
> _GNU_SOURCE
> [...]
> Since glibc 2.19, defining _GNU_SOURCE also has the effect
> of implicitly defining _DEFAULT_SOURCE. In glibc versions
> before 2.20, defining _GNU_SOURCE also had the effect of
> implicitly defining _BSD_SOURCE and _SVID_SOURCE.
> "
>
> IOWs, glibc is just being an obnoxious. I'd just drop the
> -D_BSD_SOURCE altogether, as _GNU_SOURCE should pull in everything
> we need. And looking at it further, it also defines _XOPEN_SOURCE to
> >= 500, so that could probably be dropped, too.
>

All right, so I dropped it too. We could make a glibc fork instead, but this seems to be... a bit easier. :P

Cheers.
--
Jan Tulak
jtulak@redhat.com