[libcxx-commits] [libcxx] [libc++] Introduce ABI sensitive areas to avoid requiring _LIBCPP_HIDE_FROM_ABI everywhere (PR #131156)

[Nikolas Klauser via libcxx-commits]

philnik777 wrote:

> This patch makes sense to me, but I'd like to see it again once the CI is green. I'd like to understand the issue with frozen C++03 headers. Please ping me once that's figured out and the patch can be landed once CI is green.

This wasn't actually specific to the frozen headers, it just showed in a funny way there. I just forgot to surround the `set/get_new_handler` declarations with `BEGIN/END_EXPLICIT_ABI_ANNOTATIONS`.

The main concern from my point of view is that this didn't show up in the abilist. Do we not have symbols from libc++abi in the abilist? If not, we should definitely add them or make abilists for libc++abi. I've manually diffed the `nm` output now to make sure there are no differences for both libc++ and libc++abi (specifically I used `llvm-nm path-to-lib --extern-only --defined-only --format=just-symbols`).

https://github.com/llvm/llvm-project/pull/131156