svn commit: r300967 - head/sys/sys

[Dimitry Andric]

Author: dim
Date: Sun May 29 17:32:19 2016
New Revision: 300967
URL: https://svnweb.freebsd.org/changeset/base/300967

Log:
  Stop exposing the C11 _Atomic() macro in <sys/cdefs.h>, when compiling
  for C++.  It clashes with the one in libc++'s <atomic> header.
  
  (Previously, the _Atomic() macro was defined in <stdatomic.h>, which is
  only for use with C11, but for various reasons it was moved to its
  current location in r251804.)
  
  Discussed with:	bdrewery, ed
  MFC after:	2 weeks

Modified:
  head/sys/sys/cdefs.h

Modified: head/sys/sys/cdefs.h
==============================================================================
--- head/sys/sys/cdefs.h	Sun May 29 17:26:40 2016	(r300966)
+++ head/sys/sys/cdefs.h	Sun May 29 17:32:19 2016	(r300967)
@@ -275,7 +275,8 @@
 #define	_Alignof(x)		__alignof(x)
 #endif
 
-#if !__has_extension(c_atomic) && !__has_extension(cxx_atomic)
+#if !defined(__cplusplus) && !__has_extension(c_atomic) && \
+    !__has_extension(cxx_atomic)
 /*
  * No native support for _Atomic(). Place object in structure to prevent
  * most forms of direct non-atomic access.