This commit reverts 5aaefa51 (and also partly 7f285f48e7 and b6d75682f9,
which were related to the original commit). As landed, 5aaefa51 had
unintended consequences on some downstream bots and didn't have proper
coverage upstream due to a few subtle things. Implementing this is
something we should do in libc++, however we'll first need to address
a few issues listed in https://reviews.llvm.org/D106124#3349710.
Differential Revision: https://reviews.llvm.org/D120683
libc++ has started splicing standard library headers into much more
fine-grained content for maintainability. It's very likely that outdated
and naive tooling (some of which is outside of LLVM's scope) will
suggest users include things such as <__ranges/access.h> instead of
<ranges>, and Hyrum's law suggests that users will eventually begin to
rely on this without the help of tooling. As such, this commit
intends to protect users from themselves, by making it a hard error for
anyone outside of the standard library to include libc++ detail headers.
Differential Revision: https://reviews.llvm.org/D106124
I didn't split the calendar bits more than this because there was little
benefit to doing it, and I know our calendar support is incomplete.
Whoever picks up the missing calendar bits can organize these headers
at their leisure.
Differential Revision: https://reviews.llvm.org/D116965
std::atomic is, for the most part, just a thin veneer on top of compiler
builtins. Hence, it should be available even when threads are not available
on the system, and in fact there has been requests for such support.
This patch:
- Moves __libcpp_thread_poll_with_backoff to its own header so it can
be used in <atomic> when threads are disabled.
- Adds a dummy backoff policy for atomic polling that doesn't know about
threads.
- Adjusts the <atomic> feature-test macros so they are provided even when
threads are disabled.
- Runs the <atomic> tests when threads are disabled.
rdar://77873569
Differential Revision: https://reviews.llvm.org/D114109