[libc++] Avoid using timespec when it might not be available

Summary:
The type timespec is unconditionally used in __threading_support.
Since the C library is only required to provide it in C11, this might
cause problems for platforms with external thread porting layer (i.e.
when _LIBCPP_HAS_THREAD_API_EXTERNAL is defined) with pre-C11
C libraries.

In our downstream port of libc++ we used to provide a definition of
timespec in __external_threading, but this solution is not ideal
because timespec is not a reserved name.

This patch renames timespec into __libcpp_timespec_t in the
thread-related parts of libc++. For all cases except external
threading this type is an alias for ::timespec (and no functional
changes are intended).

In case of external threading it is expected that the
__external_threading header will either provide a similar typedef (if
timespec is available in the vendor's C library) or provide a
definition of __libcpp_timespec_t compatible with POSIX timespec.

Reviewers: ldionne, mclow.lists, EricWF

Reviewed By: ldionne

Subscribers: dexonsmith, libcxx-commits, christof, carwil

Tags: #libc

Differential Revision: https://reviews.llvm.org/D63328

llvm-svn: 364012

1 files changed, 1 insertions, 1 deletions

diff --git a/libcxx/src/support/win32/thread_win32.cpp b/libcxx/src/support/win32/thread_win32.cpp
index 3ca36df808f..83e7e9f6ce5 100644
--- a/libcxx/src/support/win32/thread_win32.cpp
+++ b/libcxx/src/support/win32/thread_win32.cpp
@@ -110,7 +110,7 @@ int __libcpp_condvar_wait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m)
 }
 
 int __libcpp_condvar_timedwait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m,
-                               timespec *__ts)
+                               __libcpp_timespec_t *__ts)
 {
   using namespace _VSTD::chrono;