#include <ciso646> // So we can check the C++ standard lib macros.
#include <functional>
-// We use std::call_once on all Unix platforms except for NetBSD with
-// libstdc++. That platform has a bug they are working to fix, and they'll
-// remove the NetBSD checks once fixed.
-#if defined(LLVM_ON_UNIX) && \
- !(defined(__NetBSD__) && !defined(_LIBCPP_VERSION)) && !defined(__ppc__)
+// std::call_once from libc++ is used on all Unix platforms. Other
+// implementations like libstdc++ are known to have problems on NetBSD,
+// OpenBSD and PowerPC.
+#if defined(LLVM_ON_UNIX) && (defined(_LIBCPP_VERSION) || \
+ !(defined(__NetBSD__) || defined(__OpenBSD__) || defined(__ppc__)))
#define LLVM_THREADING_USE_STD_CALL_ONCE 1
#else
#define LLVM_THREADING_USE_STD_CALL_ONCE 0