[PATCH] D139816: [LTO] Don't generate invalid modules if "LTOPostLink" MD already exists

[Pierre van Houtryve via Phabricator via llvm-commits]

Pierre-vh added a comment.

In D139816#4080610 <https://reviews.llvm.org/D139816#4080610>, @steven_wu wrote:

> My understanding of the flag is preventing you from:
>
> - run the devirtual pass
> - add some new function
> - run the devirtual pass again
>
> The LTO devirtualization passes require visibility for all the functions when the passes are run.

Can the pass cause a miscompilation or even crash if it's run twice?
If yes, then this patch is indeed not the right solution and we should probably emit an error instead.
If no, then I don't think this patch is a bad idea to prevent the crash, but maybe we should print a warning/remark if the flag is already set?


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D139816/new/

https://reviews.llvm.org/D139816