[PATCH] D21968: [libcxx] Externally threaded libc++ variant - Take 2

[Marshall Clow via cfe-commits]

mclow.lists added inline comments.

================
Comment at: include/__external_threading:26
@@ +25,3 @@
+
+#if !defined(_LIBCPP_MUTEX_T) || \
+    !defined(_LIBCPP_MUTEX_INITIALIZER) || \
----------------
bcraig wrote:
> So users of external pthreading (or their compiler driver) would need to provide a pile of -D options on the command line?  Or is it expected that users will have their own __external_threading header that comes earlier in the include path?  Please document your expectation.
My expectation is that system vendors who have a different threading implementation will ship a customized version of the libc++ headers and dylib. 

The headers will include a replacement `include/__external_threading`, and a modified `include/__config` that contains additional `#define`s

What this patch does is to provide a customization point to produce such libraries.



https://reviews.llvm.org/D21968