[clang] [Clang] Add __builtin_get_counted_by builtin (PR #102549)

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https://github.com/Sirraide requested changes to this pull request.

Hmm, I could see how this could be useful, but it seems like a rather niche use case.

@AaronBallman Should this go through the ususal process of someone writing an RFC for it seeing as it is a language extension?

I also saw that there’s a GCC bug report (or something like that) about this. Is it clear at this point what the GCC devs’ stance on adding this as a builtin is?

As for the implementation: I’m not really too familiar w/ codegen, so I can’t comment on that part (it seems we’re maybe doing a bit too much checking in codegen as opposed to in sema, but that might just be me). I don’t think the way we’re handling this in Sema is quite right tho atm.

https://github.com/llvm/llvm-project/pull/102549