Re: [PATCH 6/13] Coarray shared memory library

Jerry D wrote:
>      Fortran: Enable coarray tests for multi image use [PR88076]
>      
>      Change some of regression tests to run on single and multiple images.
>      Add some new tests.
>      
>              PR fortran/88076
>      
>      gcc/testsuite/ChangeLog:
>      
>              * gfortran.dg/coarray/alloc_comp_4.f90: Make multi image
>              compatible.
>              * gfortran.dg/coarray/atomic_2.f90: Same.
>              * gfortran.dg/coarray/caf.exp: Also test caf_shmem and choose

I think this should be split into two parts – one part will be changing
the testcases to handle more than 1 image – and the second part that needs
to land with or after 13/13 is to actually enable it.

Regarding the first part: I or someone else still has to review those
changes.

Regarding the second part:

> --- a/gcc/testsuite/gfortran.dg/coarray/caf.exp
> +++ b/gcc/testsuite/gfortran.dg/coarray/caf.exp
> @@ -70,6 +70,12 @@ proc dg-compile-aux-modules { args } {
>       }
>   }
>   
> +if { [getenv GFORTRAN_NUM_IMAGES] == "" } {
> +  # Some caf_shmem tests need at least 8 images.  This is also to limit the
> +  # number of images on big machines preventing overload w/o any benefit.
> +  setenv GFORTRAN_NUM_IMAGES 8
> +}
> +

FYI only: When doing remote testing, DejaGNU does not properly forward 
environment variables. I assume it also works somewhat gracefully when 
it is unset.

> +    foreach flags $option_list {
> +        verbose "Testing $nshort (libcaf_shmem), $flags" 1
> +        set gfortran_aux_module_flags "-fcoarray=lib $flags -lcaf_shmem"
> +        dg-test $test "-fcoarray=lib $flags -lcaf_shmem" {}
> +        cleanup-modules ""
> +    }

As mentioned in 13/13, the current implementation seems to assume that 
POSIX threads are available; additionally, -lpthread or -pthread might 
be needed for linking. In any case, it seems as if some check is 
required whether caf_shmem is actually available; otherwise, the shmem 
tests have to be skipped.

Tobias