[libcxx-commits] [PATCH] D108203: [libc++] Rely solely on using_if_exists for ::aligned_alloc, ::quick_exit and ::timespec_get

[Dimitry Andric via Phabricator via libcxx-commits]

dim added a subscriber: emaste.
dim accepted this revision.
dim added a comment.

In D108203#2949462 <https://reviews.llvm.org/D108203#2949462>, @ldionne wrote:

> Expand the change to timespec_get and quick_exit.
>
> Note that we'll have to wait for a while before we can submit this change, since we need to drop support
> for Clang 12 (which doesn't support the attribute).

Hm, that's a pity, I wasn't aware that this attribute was introduced so relatively recently. We have clang (and libc++) 11.0.1 in FreeBSD 12.x, which is going to be supported for a while, still. FreeBSD 13.0 and later have clang/libc++ 12.0.1.

> I'm putting this patch up for review to give a heads
> up to vendors and to show that this is the ideal direction for the library, but I'll also have to fix the
> incorrect logic separately on Apple platforms.

In FreeBSD we always import mostly  complete copies of the llvm-project tree (except for the parts we don't use), so clang and libc++ are always upgraded at the same time. That said, we also support building the base system (including libc++) using other toolchains such as external gcc's, but we will be able to add version checks for those.

@emaste I think FreeBSD has had `aligned_alloc`, `quick_exit` and `timespec_get` for a very long time now? At least for all supported versions?


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https://reviews.llvm.org/D108203