[PATCH] D129540: [lld-macho] Enable EH frame parsing / pruning

[Jez Ng via Phabricator via llvm-commits]

int3 added a comment.

> we are adding to the [n]ever-ending list of knobs that one needs to set to have compatible behaviours with LD64 and I worry it's getting a bit ugly

But parsing / relocating / pruning EH frames *is* what LD64 is doing, so to be compatible with it, we should turn this on :)

It's also a correctness issue -- w/o this flag, we aren't actually applying the right relocations to our EH frames.

Moreover the compiler flag is only needed for perf reasons, and it helps both LLD and LD64, so it's something that can likely be turned on globally (unless you are targeting old x86_64 platforms)

> if not, can we also add a note for this to the documentation somewhere?

This should be documented somewhere for sure, but the question is where... it's not really a diff between ld64 and LLD, so `ld64-vs-lld.rst` is not the right place. I will of course put it in the release notes for sure when the time comes for the llvm-15 cut. And I suppose once we have a full-blown LLD-MachO doc page we can mention this compiler flag there?


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D129540