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

[Derek Schuff via libcxx-commits]

dschuff wrote:

> This is purely about whether we consider it a bug that adding `[[gnu::visibility("hidden")]]` on the `std` namespace inside headers bleeds to user specializations. (Also note that `[[gnu::visibility("default")]]` doesn't bleed to user specializations)

This bit is actually also relevant, because it makes working around the issue more annoying and invasive, since as mentioned above you can't "correct" the bleed into userspace using the same scoped mechanism that caused it to leak in the first place. Also because regardless of what the standard says, this behavior change exposes users to differences in implementation between gcc and clang, that make workarounds more difficult.

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