doc: dependency graph generation for modules/files/functions would be useful for refactoring legacy

[jfdev001]

Since the goal of this repo is to provide boiler plate for cmake fortran projects, and such projects could be legacy code, it is important to consider how one might use the contents of this repo to faciliate refactoring a legacy codebase:

https://understandlegacycode.com/blog/safely-restructure-codebase-with-dependency-graphs/

https://www.miquido.com/blog/legacy-code-refactoring/

https://fortdepend.readthedocs.io/en/latest/

See also

doxygen/doxygen#6243

[jfdev001]

The INCLUDE call at the top of the src/mo_square.f90 throws off the doxygen generator and prevents the file from being recognized as a module.... is it possible to use cmake to have the proper include to prevent this issue???

[jfdev001]

https://github.com/bertdupe/Matjes/blob/5757b48900c644b6c2e8d9d37905b098a8d6fb13/cmake/Files_and_Targets.cmake#L25

Search on github for cmake projects using spblas... there are some that do not call the include above the module, which is what's throwing off doxygen:

https://github.com/bertdupe/Matjes/blob/5757b48900c644b6c2e8d9d37905b098a8d6fb13/src/Hamiltonian_type/ham_mkl_csr.f90#L4

[jfdev001]

https://www.intel.com/content/www/us/en/docs/onemkl/developer-guide-macos/2023-0/cmake-config-for-onemkl.html

[jfdev001]

Need to have the .mod file for mkl_spblas in the include/ dir, otherwise you are forced to do the INCLUDE mkl_spblas.f90 call...

https://community.intel.com/t5/Intel-oneAPI-Math-Kernel-Library/mkl-spblas-mod-files/td-p/1095681

Could do something like add compilation of desired mkl_spblas.f90 and then just write this to the src/ dir or somewhere else (write it to the Fortran_MODULE_DIRECTORY...)

Two options:
(1) copy file and compile outside of /opt/ intel installation directory and then call ifx -c mkl_spblas.f90
(2) or just root and then compile in /opt dir....

need to test this

[jfdev001]

Should have target added for
MKL... i.e., just a dummy program that includes mkl, that program gets compiled
and therefore mkl_spblas.f90... this way user doesn't have to rely on root permissions and cmake can handle everything for you!!

[jfdev001]

test_spblas doesn't seem to work so even with the example of use mkl_spblas being valid in src/mo_square...

Resolved by #23

[jfdev001]

If fpm compliant (?) (see also #26), then can use

https://github.com/davidpfister/fpm-modules