Support Coarray Fortran applications

[nchaimov]

Per Sameer, users at a tutorial he gave requested support for Coarray Fortran in TAU Commander:

They were asking when TAU Commander would support CAF, so we could say "tau caf foo.f90; tau cafrun -n 4 ./a.out".

[zbeekman]

caf is a Fortran compiler wrapper for OpenCoarrays, just like mpif90 is an MPI implementation's wrapper for the Fortran compiler.

Right now caf and OpenCoarrays uses MPI as the back-end for the communication layer. The larger difficulty will be updating tau itself to perform the mapping of constructs correctly between coarray Fortran and the underlying implementation of the parallel runtime library, and syntax parsing etc.

For OpenCoarrays, to start, we could just have taucmdr recognize caf and cafrun as scripts akin to mpif90 and mpiexec. caf should be fairly straight forward to get basic functionality, but mpiexec is usually a compiled program, no? So we will need to direct tau/taucmdr to the mpiexec/mpirun app.

This may actually not be too, hard, in theory, we could pass the --show flag to cafrun (or caf even) which, when combined with additional arguments will print the command line that it would have otherwise executed. i.e. tau caf -c foo.f90 will cause tau to execute caf --show -c foo.f90 which will return something like

/path/to/gfortran -I /path/to/mpi/fortran/include/loc -I /path/to/OpenCoarrays/include/loc -c foo.f90 -l/path/to/mpi/libmpi.so

which we can then handle in the normal way that TAU commander handles MPI applications.

For tau cafrun -n 4 ./a.out to can execute cafrun --show -n 4 ./a.out which will return something like:

/path/to/mpiexec -np 4 ./a.out

I have been needing/wanting to fix the janky argument parsing in caf and cafrun for a while so we can make adjustments to accommodate TAU/TAU Commander needs, assuming they make design sense.

[nchaimov]

Done in db895b1f7d112a1d7359975a7c3a931d38dec395 for OpenCoarrays.