On Sat, 9 Feb 2013 19:57:20 +0100
Ian Kumlien <pomac@vapor.com> wrote:

> On Sat, Feb 09, 2013 at 09:02:06PM +0300, Sergei Trofimovich wrote:
> > On Sat,  9 Feb 2013 00:30:21 +0100
> > Ian Kumlien <pomac@demius.net> wrote:
> > 
> > > My builds are cluttered with:
> > > <command-line>:0:0: warning: "_FORTIFY_SOURCE" redefined [enabled by
> > > default]
> > > 
> > > Which makes it hard to tell if something breaks or not.
> > 
> > > I don't know about you, but bilding with 
> > > GCC 4.7.2 on gentoo, this is a issue.
> > 
> > Unfortunately it's a gentoo specific gcc bug. I'd suggest reporting
> > it to bugs.gentoo.org. That -D by default breaks linux's perf as well
> > (due to -D_FOTIFY_SOURCE=2 -Werror in perf sources).
> 
> Is it? There is a workaround in the android build system for compilers
> on ubuntu.
> 
> Where can i find that bug report?

I think you need to fill the new one.

> This is not a emerge, this is a normal system build.

Yeah, gentoo has patched gcc specs so you get -D_FORTIFY_SOURCE=2
in gcc command line by default.

http://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo/src/patchsets/gcc/4.6.0/gentoo/10_all_default-fortify-source.patch?view=markup

> > Current workaround is to pass AM_CFLAGS to make:
> >     make AM_CFLAGS=stuff_w/o_fortify_source
> > It's what gentoo's live ebuild does.
> 
> I can't see it here in the live ebuild... 

sys-fs/btrfs-progs/btrfs-progs-9999.ebuild:
...
src_compile() {
        emake \
                CC="$(tc-getCC)" \
                AM_CFLAGS=-D_FILE_OFFSET_BITS=64 \
                ...
}

This line overrides in-Makefiles AM_CFLAGS.

-- 

  Sergei