The openmp derivation provides both libomp and libompv. To avoid
accidentally linking with the wrong library and to avoid the nosv
dependency on libomp, this patch separates each version in a different
derivation.
Also, it adapts the clang wrappers and stdenvs to provide an stdenv per
openmp library where each openmp will be used by default when the
compiler flag "-fopenmp" is used. This eases linking ompv with nixpkgs
libraries, such as blis, that expect openmp to be provided with stdenv.
Reviewed-by: Rodrigo Arias Mallo <rodrigo.arias@bsc.es>
Tested-by: Rodrigo Arias Mallo <rodrigo.arias@bsc.es>
This is needed since nosv must appear as a 1rst level dependency on the
final executable. Clang will add the dependency as long as it knows
where to find nosv (and nodes is used).
Reviewed-By: Rodrigo Arias Mallo <rodrigo.arias@bsc.es>