[PATCH] D75395: [clang][Modules] Add -fsystem-module flag

[Duncan P. N. Exon Smith via Phabricator via cfe-commits]

dexonsmith added a comment.

> This is used when
>  converting an implicit build to an explicit build to match the
>  systemness the implicit build would have had for a given module.

I had another thought.  What if for the explicitly built "system" modules:

- If `-Wsystem-headers` is on, leave them as user modules in the explicit build.
- If `-Wsystem-headers` is off, turn off all diagnostics in the explicit build.

Does that give the right semantics, or is there something subtly different?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D75395/new/

https://reviews.llvm.org/D75395