[PATCH] D103988: SampleFDO] place the discriminator flag variable into the used list.

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added a comment.

CommonLinkage doesn't work.

Whether `appendToUsed` is needed depends on whether the runtime has a live section referencing `__llvm_fs_discriminator__`.
If the runtime has the guarantee, no need for `appendToUsed`.

Otherwise, the first revision `appendToUsed` with `WeakODRLinkage` looks good to me.

`appendToUsed` with `ExternalLinkage` in a comdat works as well, but comdat will need extra code when Mach-O wants this feature.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D103988/new/

https://reviews.llvm.org/D103988