[libvirt] [PATCH v4 1/2] src/Makefile: move the new xen_xl_disk parser code at the correct place

[Ian Campbell]

On Thu, 2015-01-08 at 16:43 -0700, Jim Fehlig wrote:
> Eric Blake wrote:
> > On 01/08/2015 06:20 AM, Pavel Hrdina wrote:
> >   
> >> Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
> >> ---
> >>  src/Makefile.am | 34 +++++++++++++++++-----------------
> >>  1 file changed, 17 insertions(+), 17 deletions(-)
> >>     
> >
> >   
> >>  
> >>  if WITH_XENCONFIG
> >> +AM_LFLAGS = -Pxl_disk_ --header-file=../$*.h
> >>     
> >
> > Uggh.  Not your fault (this patch was just code motion), but it
> > highlights a portability problem: RHEL 5 ships with flex 2.5.4, which
> > lacks --header-file, and which spells --outfile only as -o.  The build
> > is failing with:
> >
> > flex  -Pxl_disk_
> > --header-file=/home/dummy/libvirt/src/xenconfig/xen_xl_disk.h
> > --outfile=/home/dummy/libvirt/src/xenconfig/xen_xl_disk.c
> > xenconfig/xen_xl_disk.l
> > flex: unknown flag '-'.  For usage, try
> >         flex --help
> >   
> 
> Sigh...  Sorry for all the grief this has caused.  I wasted a huge
> amount of time trying to get all of this working right, including some
> of the approaches in the follow-up patches, but always hit some sort of
> problem.  I thought I finally had everything worked out with the V3
> patches that Michal ACKed.  But given all the problems I encountered
> along the way, I suppose I shouldn't be surprised by the problems folks
> are seeing.  So now I'm causing others to waste time :-(.  Again, I'm
> sorry for that.
> 
> And of course this has rippled to the Xen push gate tests too.

NB only our libvirt push gate, which isn't really gating anything, the
result just becomes the baseline for next time and becomes what is used
for testing !libvirt.

So it's not currently impacting our testing of anything other than new
versions of libvirt. Testing of xen-unstable and stable will keep using
the old/working version of libvirt until it is fixed.

> I suppose it is possible to include some minimal header in libvirt (or
> an extern declaration?) for the xlu_disk_parse() function, and actually
> link against the libxlutil.so which is installed.  I can work on such an
> approach if folks think it is worthwhile.

FWIW MHO is that sticking the hack in an #ifndef HAVE_LIBXLUTIL_H (from
AC_CHECK_HEADER) isn't so terrible
(http://lists.xen.org/archives/html/xen-devel/2015-01/msg00715.html)

Ian.