[flang-commits] [clang] [flang] [flang][driver] Add pre-processing type to `.i` (pre-processed) files (PR #104664)

[Andrzej Warzyński via flang-commits]

banach-space wrote:

For context, this PR documents the origins of .i in the context of `flang-new`:
* https://github.com/llvm/llvm-project/commit/a65afce731c2fa91effcfa5d4917d6ad90a28bf0

If these files are already pre-processed, why would we add `phases::Preprocess` to the list of compilation phases? Also, it's still unclear to me what issue is:

> This solves a bug when using --save-temps with source files that include modules from non-standard directories

IIRC, the generated temp files (e.g. *.i) are used for the subsequent compilation phases. So, after pre-processing file.f90 we'd get file.i with all the modules included, no? So `-I` shouldn't be a concern, right?

Please bear with me, it's been a while since I've touched this and also, I am afk 😅

https://github.com/llvm/llvm-project/pull/104664