[flang-commits] [flang] [llvm] [flang-rt] Implement iso module in C++ in the runtime (PR #197687)

[Michael Kruse via flang-commits]

Meinersbur wrote:

> Isn't it possible to have dependency on flang and the Fortran module in one configuration and do not have it in another? What I am suggesting is to add a CMake option like `FLANG_RT_BUILD_WITHOUT_FLANG`: the configuration step will not use the Fortran module and will not set dependency on flang, if this option is set. Otherwise, we will keep using the real Fortran module built by flang to get the corresponding binary file.

I am not looking forward into maintaining two redundant versions. Generally, contributors also rarely think about updating configurations that they do not use. By experience, those go out of maintanance/grow inconsistencies over time.

For iso_fortran_env in particular, if this is about consistency with Flang's understanding of these kinds, I think a unittest would be the best approach. 

https://github.com/llvm/llvm-project/pull/197687