From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Campbell <Ian.Campbell@citrix.com>
Subject: Re: [PATCH] tools: work around collision of -O0 and
 -D_FORTIFY_SOURCE
Date: Thu, 5 Feb 2015 12:25:48 +0000
Message-ID: <1423139148.24924.100.camel@citrix.com>
References: <54D25E95020000780005CFD8@mail.emea.novell.com>
	<21715.20257.88376.581397@mariner.uk.xensource.com>
	<54D35F85020000780005D36C@mail.emea.novell.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
Received: from mail6.bemta3.messagelabs.com ([195.245.230.39])
	by lists.xen.org with esmtp (Exim 4.72)
	(envelope-from <Ian.Campbell@citrix.com>) id 1YJLVV-0006Fi-NV
	for xen-devel@lists.xenproject.org; Thu, 05 Feb 2015 12:26:05 +0000
In-Reply-To: <54D35F85020000780005D36C@mail.emea.novell.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Jan Beulich <JBeulich@suse.com>
Cc: Euan Harris <euan.harris@citrix.com>, xen-devel <xen-devel@lists.xenproject.org>, Ian Jackson <Ian.Jackson@eu.citrix.com>, Wei Liu <wei.liu2@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>
List-Id: xen-devel@lists.xenproject.org

On Thu, 2015-02-05 at 11:18 +0000, Jan Beulich wrote:
> >>> On 05.02.15 at 12:08, <Ian.Jackson@eu.citrix.com> wrote:
> > Jan Beulich writes ("[PATCH] tools: work around collision of -O0 and 
> > -D_FORTIFY_SOURCE"):
> >> The former gets enforced by our debug builds, the latter appears to be
> >> not uncommon for certain distros' Python packages. Newer glibc warns on
> >> uses of _FORTIFY_SOURCE without optimization being enabled, which with
> >> -Werror causes the build to fail.
> > ...
> >> --- a/tools/pygrub/Makefile
> >> +++ b/tools/pygrub/Makefile
> >> @@ -2,15 +2,24 @@
> >>  XEN_ROOT = $(CURDIR)/../..
> >>  include $(XEN_ROOT)/tools/Rules.mk
> >>  
> >> +py_cflags := $(shell $(PYTHON)-config --cflags)
> >> +PY_CFLAGS = $(if $(strip $(py_cflags)),,\
> >> +                 $(error '$(PYTHON)-config --cflags' produced no output))\
> >> +            $(if $(filter -D_FORTIFY_SOURCE=%,\
> >> +                          $(filter-out -D_FORTIFY_SOURCE=0,\
> >> +                                       $(py_cflags))),\
> >> +                 $(patsubst -O0,-O1,$(CFLAGS)),\
> >> +                 $(CFLAGS)) $(APPEND_LDFLAGS)
> > 
> > There are lots of copies of this.  And it would IMO be better to do at
> > least the probing in configure, resulting in something like this in
> > configure:
> > 
> >  [ determine PY_XCFLAGS to be either '' or '-O0' ]
> >  AC_SUBST(PY_XCFLAGS)
> > 
> > and
> > 
> >  PY_CFLAGS=@PY_CFLAGS@
> > 
> >     CC="$(CC)" CFLAGS="$(CFLAGS) $(PY_XCFLAGS)" $(PYTHON) setup.py build
> > 
> > (I assume that CFLAGS does override what comes out of setup.py.)
> 
> For one, PY_XCFLAGS='' wouldn't help, as we get -O0 from the
> incoming CFLAGS. And then I'm not really intending to fiddle with
> the configure scripts (albeit, having done the patch in the presented
> form, I expected you to want it done that way) - this and alike is
> what I specifically want to stay out of if at all possible. Since in any
> event commit 1166ecf781 introduced a regression for multiple
> people, perhaps if that is not supposed to be reverted Euan should
> look into addressing that regression?

Euan -- do you think you might be able to whip up an autoconf-ification
along the lines of what is described above?

Ian.