f18 tooling driver modules requires extra flag to be usable

[naromero77]

I believe this is different from similar module related bugs that have been submitted by others. I am using the f18 driver. I believe Fortran modules are working, since I can get a simple program to work.

This occurs during compilation of the Fortran bindings for the latest stable version of mpich 3.3.2.

Start by compiling the mpi_constants.f90 which generates mpi_constants.mod, then compile mpi_base.f90

mpich_module_error.tar.gz

[naromero77]

OK, I think that I have figured it out. There problem is not specific to the source code I provided, but affects all modules.

As some point in the past (>2 months ago), the f18 driver worked with no additional flags. But now invoking f18 generates:
.mod

which is not usable by f18 (which calls the PGI compiler to generate the object file)

however, if you add -module-suffix .f18.mod flag to the f18 invokation, you generate two files:
.mod
.f18.mod

which can be used to generate real code with f18

There is also a flang.sh that adds the necessarily flags behind scenes to make it usable.

@AlexisPerry Do you know what the correct behaviour should be?

[DavidTruby]

The f18 driver is intended to be temporary and a new driver based on the Clang driver code is currently being worked on. Perhaps we should keep an eye on this issue for the new driver?