Add missing dollar # OpenMP directive.

[ivan-pi]

Closes #840.

[ivan-pi]

I suppose a simple unit test could look as follows:

program test_get_os_type

!$ use omp_lib, only: omp_get_num_threads, omp_get_thread_num, &
!$    omp_get_max_threads
   use fpm_environment, only: get_os_type
   implicit none

   integer, allocatable :: os(:)
   integer :: n, i

   n = 1
!$ n = omp_get_max_threads()
   print *, "num_threads = ", n

   allocate(os(0:n-1))

   i = 0
!$omp parallel
!$ i = omp_get_thread_num()
   os(i) = get_os_type()
!$omp end parallel

   print *, all(os == os(0))

end program

The results I get:

$ fpm test test_get_os_type --flag -fopenmp
 num_threads =            4
 T

From a quick glance at CI.yml I don't think the parallel build features are being tested currently.

A few questions related to this:

• Does the bootstrap fpm require parallel features?
• Would it suffice to add another parallel test target? This would be similar to the one near line:

  fpm/.github/workflows/CI.yml

  Line 148 in 4be07af

  - name: Test Fortran fpm

  , but with the addition of the -fopenmp flag.
• Should the CI target run all tests, or only the ones that might use parallel execution?

[awvwgk]

Good catch, thanks for sharing.

[awvwgk]

In case we want to support testing with threading enabled we should still run the full testing IMO.