Libguestfs - Mar 2014 - Re: [PATCH] Fix building on architectures where ocamlopt is not available

* Richard W.M. Jones:
>> I think that an extra target (mlguestfs.cmxa: mlguestfs.cma) would make
>> the .NOTPARALLEL unnecessary.
>
> Right, I remember this was a problem now.
>
> It was fixed by:
>
>
https://github.com/libguestfs/libguestfs/commit/dce94f3e266ed3f1fc634a1ef6953f2db1510963
>
> Do you think we could re-add the stamp-file / touch $@ ?
Sure, it would have to be modified so it still works if OCAMLOPT is not
available -- that's why I made that change in the first place.

Wouldn't a rule without commands such as

mlguestfs.cmxa: mlguestfs.cma

also prevent make from building the two targets in parallel?

Cheers,
-Hilko

On Sat, Mar 22, 2014 at 01:22:06PM +0100, Hilko Bengen
wrote:
> * Richard W.M. Jones:
> 
> >> I think that an extra target (mlguestfs.cmxa: mlguestfs.cma) would
make
> >> the .NOTPARALLEL unnecessary.
> >
> > Right, I remember this was a problem now.
> >
> > It was fixed by:
> >
> >
https://github.com/libguestfs/libguestfs/commit/dce94f3e266ed3f1fc634a1ef6953f2db1510963
> >
> > Do you think we could re-add the stamp-file / touch $@ ?
> 
> Sure, it would have to be modified so it still works if OCAMLOPT is not
> available -- that's why I made that change in the first place.
> 
> Wouldn't a rule without commands such as
> 
> mlguestfs.cmxa: mlguestfs.cma
> 
> also prevent make from building the two targets in parallel?
Doesn't that mean that if mlguestfs.cmxa is out of date, simply
running the mlguestfs.cma rule will build it (which it won't)?

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v

* Richard W.M. Jones:
>> Wouldn't a rule without commands such as
>> 
>> mlguestfs.cmxa: mlguestfs.cma
>> 
>> also prevent make from building the two targets in parallel?
>
> Doesn't that mean that if mlguestfs.cmxa is out of date, simply
> running the mlguestfs.cma rule will build it (which it won't)?
Not sure if I understand you. 

If I cause mlguestfs.cmxa to be out of date by touching guestfs.cmx,
only mlguestfs.cmxa will be rebuilt.

If I cause mlguestfs.cma to be out of date by touching guestfs.cmo, both
mlguestfs.cma and mlguestfs.cmxa will be rebuilt. This could be fixed by
using an order-only prerequisite:

mlguestfs.cmxa: | mlguestfs.cma

Cheers,
-Hilko