Change src file extensions to F90

[cbegeman]

The file extension of the main routine ppr_1d.f90 needed to be F90 in order for cmake to recognize the c-style # include lines. Since the library is in active use, a copy of ppr_1d was created with the F90 extension.

[dengwirda]

@cbegeman, did creating a second ppr_1d.F90 that contains #include ppr_1d.f90 work out okay as an alternative in the end? Thanks very much for looking into this.

[cbegeman]

@dengwirda That looks like it's working out fine. Wish the solution was more elegant!

[dengwirda]

@cbegeman, I still need to do some more testing on this, but I think this might be an alternative *.F90 vs *.f90 option:

PPR/src/ppr_1d.F90

Line 4 in 4e2aa43

# include "ppr_1d.f90"

[cbegeman]

@dengwirda Can you update me on where you got with your testing of this #include "ppr_1d.f90" version? As we move toward opening the VLR PR, let's settle on one of the two options we identified. Thanks!

[dengwirda]

Hi @cbegeman, I'd say the version that's in dev presently is my prefered option --- the single additional ppr_1d.F90 that simply # include's the actual ppr_1d.f90 library, and keeps compatibility with existing workflows.
I've confirmed that this seems to work as expected for gfortran workflows --- do you think this should satisfy E3SM in general? If so, I'll merge this into master which should then make it available in E3SM via git submodule update --init --recursive.

[cbegeman]

@dengwirda Could you take a look at my latest VLR branch https://github.com/cbegeman/E3SM/tree/ocn/add-vertical-remap-feature? I'm getting E3SM build errors with this #include option. The most relevant files for the build are https://github.com/cbegeman/E3SM/blob/ocn/add-vertical-remap-feature/components/mpas-ocean/src/Makefile and https://github.com/cbegeman/E3SM/blob/ocn/add-vertical-remap-feature/components/mpas-ocean/src/ocean.cmake

[cbegeman]

@dengwirda The following worked for me:

• Anvil, intel compiler, successful run with VLR branch and VLR on (executing PPR calls)
• Anvil, intel compiler, successful (bfb) comparison between VLR branch and master
• Anvil, gnu compiler, successful (bfb) comparison between VLR branch and master

Is there any other testing that you think is necessary before merging this PR?

Note: VLR branch is based on E3SM-Ocean-Discussion/E3SM/master and uses this PPR branch, master refers to E3SM-Ocean-Discussion/E3SM/master

[whannah1]

Seems like this PR is pretty stale, but Having two copies of ppr_1d with "f" and "F" is very annoying when I'm working locally on a mac where file names are handled in a case-insensitive way. My local E3SM repository always shows the PPR submodule as "dirty" and shows uncommitted changes as the difference between these two files. I have the same problem with "example/ex_1.F90".

Is there a way to rename these files so that it's not just the case of one letter that is changing?

[dengwirda]

@whannah1 originally there was indeed only a single *.f90 extension used throughout, and the -cpp flag was used to enable the preprocessor. The *.F90 workaround was added due to E3SM's build system (at least at the time) requiring it.
If there's another option available I'd be happy to consider it!