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

* Richard W.M. Jones:
> On Fri, Feb 28, 2014 at 02:35:56PM +0100, Hilko Bengen wrote:
>> diff --git a/ocaml/Makefile.am b/ocaml/Makefile.am
>> index 5dd2c9b..708b2e7 100644
>> --- a/ocaml/Makefile.am
>> +++ b/ocaml/Makefile.am
> [...]
>> +# Tell version 3.79 and up of GNU make to not build goals in this
>> +# directory in parallel.
>> +.NOTPARALLEL:
>
> ^ This makes building the OCaml subdirectory very slow (I normally
> build with MAKEFLAGS=-j9).  Was there a reason for adding this?
I think I added this because both the mlguestfs.cma and mlguestfs.cmxa
targets generate libmlguestfs.a:

mlguestfs.cma: libguestfsocaml.a guestfs.cmo
	$(OCAMLMKLIB) -o mlguestfs \
	  $(libguestfsocaml_a_OBJECTS) guestfs.cmo \
	  -L$(top_builddir)/src/.libs -lguestfs

mlguestfs.cmxa: libguestfsocaml.a guestfs.cmx
	$(OCAMLMKLIB) -o mlguestfs \
	  $(libguestfsocaml_a_OBJECTS) guestfs.cmx \
	  -L$(top_builddir)/src/.libs -lguestfs

As far as I know, those are the only targets that shouldn't be run
parallel. 

I think that an extra target (mlguestfs.cmxa: mlguestfs.cma) would make
the .NOTPARALLEL unnecessary.

Cheers,
-Hilko

On Sat, Mar 22, 2014 at 11:36:33AM +0100, Hilko Bengen
wrote:
> * Richard W.M. Jones:
> 
> > On Fri, Feb 28, 2014 at 02:35:56PM +0100, Hilko Bengen wrote:
> >> diff --git a/ocaml/Makefile.am b/ocaml/Makefile.am
> >> index 5dd2c9b..708b2e7 100644
> >> --- a/ocaml/Makefile.am
> >> +++ b/ocaml/Makefile.am
> > [...]
> >> +# Tell version 3.79 and up of GNU make to not build goals in this
> >> +# directory in parallel.
> >> +.NOTPARALLEL:
> >
> > ^ This makes building the OCaml subdirectory very slow (I normally
> > build with MAKEFLAGS=-j9).  Was there a reason for adding this?
> 
> I think I added this because both the mlguestfs.cma and mlguestfs.cmxa
> targets generate libmlguestfs.a:
> 
> mlguestfs.cma: libguestfsocaml.a guestfs.cmo
> 	$(OCAMLMKLIB) -o mlguestfs \
> 	  $(libguestfsocaml_a_OBJECTS) guestfs.cmo \
> 	  -L$(top_builddir)/src/.libs -lguestfs
> 
> mlguestfs.cmxa: libguestfsocaml.a guestfs.cmx
> 	$(OCAMLMKLIB) -o mlguestfs \
> 	  $(libguestfsocaml_a_OBJECTS) guestfs.cmx \
> 	  -L$(top_builddir)/src/.libs -lguestfs
> 
> As far as I know, those are the only targets that shouldn't be run
> parallel. 
> 
> 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 $@ ?

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://libguestfs.org

* 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