Update for cmake use of neural-fortran

[mathomp4]

I recently tried building neural-fortran and then wanted to try and use it with an external code (which were essentially the examples herein).

In doing so, I couldn't quite get the current Findneural-fortran.cmake file from #178 (via #166) to work for me.

So, I did some hacking around and came up with this PR. The changes are:

1. Simplify the Findneural-fortran.cmake file. The original was a bit above me so I made something a bit easier to use. For this one, a user needs to set neural-fortran_ROOT_DIR such that neural-fortran_ROOT_DIR/lib/libneural-fortran.a exists. It also looks for the .mod files as those are also needed for external use.
2. Install the .mod files to CMAKE_INSTALL_PREFIX/include so that they can be found by the find_package
3. Install the Findneural-fortran.cmake in CMAKE_INSTALL_PREFIX/include/cmake/neural-fortran...which might not be the best place. I just wanted to put it somewhere in the install
4. Update the README with a bit more info

In my testing, this all seems to work both for external and internal use. For example:

cmake -B build -S . --install-prefix=$(pwd)/install -Dneural-fortran_BUILD_TESTING=YES -Dneural-fortran_BUILD_EXAMPLES=YES
cmake --build build
cmake --install build
ctest --test-dir build

all worked and the examples seem to as well.

I'm going to keep this draft (for now) until @milancurcic can test. I'd also like to make sure I haven't broken the workflow of @jvdp1 who added the first Findneural-fortran.cmake file. And I guess I'll ping @aminiussi who is the filer of #166

[mathomp4]

Huh. I didn't seem to trigger the CI...

[mathomp4]

Also: I don't know how to use fpm so I hope I didn't break that!

[milancurcic]

I think the CI is configured to only trigger CI on source changes. We should fix that!

Thanks for this, will test. fpm doesn't care about this part.

[mathomp4]

I think the CI is configured to only trigger CI on source changes. We should fix that!

Thanks for this, will test. fpm doesn't care about this part.

Ahh. I could update that in my PR? We can add CMakeLists.txt to the "if changed" list.

[mathomp4]

Okay, CMakeLists.txt added and I fiddled a bit with the CI. Looks like you have to approve the CI run 😄

[milancurcic]

Thank you!

[milancurcic]

Thanks @mathomp4, I'm not merging in case you're still working on it, let me know when good to merge.

[mathomp4]

Thanks @mathomp4, I'm not merging in case you're still working on it, let me know when good to merge.

@milancurcic I think I'm good. Once it's in, I'll give it a test but this works for me!

[mathomp4]

Thanks for merging! I'll work with main until next release :)