[PATCH] D14731: [libcxx] Add clang thread safety annotations to mutex and lock_guard

[Marshall Clow via cfe-commits]

mclow.lists added a comment.

In general, this looks fine. There are a few nits.

1. There needs to be a way to disable these annotations.

The usual way in libc++ is to check to see if `_LIBCPP_THREAD_ANNOTATION` is already defined, and if so, do not define it. We usually state things in the negative, so the controlling macro should be `_LIBCPP_HAS_NO_THREAD_ANNOTATION`

2. We need to support non-ToT versions of clang, so the test needs to be more nuanced than `#if defined(__clang__)`. See L432 of <__config> for an example there.

More as I see them


http://reviews.llvm.org/D14731