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

[Jim Fehlig]

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.  I
responded to one such test failure today on xen-devel, to which Ian
Campbell replied that the parsing code in Xen was placed in libxlutil to
avoid libxl apps needing to create their own parsing code

http://lists.xen.org/archives/html/xen-devel/2015-01/msg00657.html

My immediate thought was cool, I can use that and remove all the flex
nonsense before the next libvirt release.  But alas, the related header
file (libxlutil.h) has never been installed and thus not included in any
distro's xen-devel package

http://lists.xen.org/archives/html/xen-devel/2015-01/msg00690.html

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.

Regards,
Jim