[flang-commits] [clang] [flang] [flang] Adding support of -fcoarray flang and init PRIF (PR #151675)

[Katherine Rasmussen via flang-commits]

https://github.com/ktras commented:

@JDPailleux Thanks, this is a great start. I can confirm that by using this branch, I am able to build a Flang that can build a PRIF runtime library ([Caffeine](https://go.lbl.gov/caffeine)) and then link to that library while compiling an executable that can then be run with multiple images.

This is not a strong requirement from me, but what do you think about adding a warning when users use the `-fcoarray` flag, so that it is clear that the features associated with this flag are still in development. Perhaps something similar to the warning when users provide the `-fdo-concurrent-to-openmp` flag? That warning is `"Mapping do concurrent to OpenMP is still experimental."` and it is produced in `flang/lib/Frontend/FrontendActions.cpp`. If a similar warning is deemed helpful for users of the `-fcoarray` flag, I would recommend something like: `"Support for multi image Fortran features is still experimental and in development."` Since any specific multi image features that are not yet lowered would be caught by the general error for features that are not yet implemented, this additional warning with the `-fcoarray` flag may not be necessary, it is just a potential option.

Please also note and respond to the review feedback above from @clementval.

https://github.com/llvm/llvm-project/pull/151675