[PATCH] D28481: Respect section groups in GC

[Rafael Avila de Espindola via llvm-commits]

Evgenii Stepanov <eugenis at google.com> writes:

> Why? When is this beneficial?

Being able to remove unused parts of comdats. It also avoid sections not
in a comdat being a special case.

> Note that comdats in LLVM IR are associative when targeting COFF and
> ELF/bfd, and non-associative in ELF/gold and ELF/lld. This change
> makes the behavior more consistent.

ELF is a different format. Some features don't map 1:1 to COFF. In the
IR you cannot remove part of a comdat because you don't know if that is
still going to be the input to the linker or not.

Cheers,
Rafael