Fix various GCC mis-configurations for newer versions.
This patch goes through and enables C++11 and C++14 features for newer GCC's.
The main changes are:
1. Turn on variable templates. (Uses __cpp_variable_templates)
2. Assert atomic<Tp> is trivially copyable (Uses _GNUC_VER >= 501).
3. Turn on trailing return support for GCC. (Uses _GNUC_VER >= 404)
4. XFAIL void_t test for GCC 5.1 and 5.2. Fixed in GCC 6.
llvm-svn: 255585
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 831c1129547c973c59ccb957ed9fe0cf74102477
diff --git a/include/__config b/include/__config
index 211b5e9..ec44f76 100644
--- a/include/__config
+++ b/include/__config
@@ -472,7 +472,9 @@
#endif
// GCC 5 will support variable templates
+#if !defined(__cpp_variable_templates) || __cpp_variable_templates < 201304L
#define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
+#endif
#define _NOEXCEPT throw()
#define _NOEXCEPT_(x)
@@ -494,7 +496,6 @@
#else // __GXX_EXPERIMENTAL_CXX0X__
-#define _LIBCPP_HAS_NO_TRAILING_RETURN
#define _LIBCPP_HAS_NO_ALWAYS_INLINE_VARIADICS
#if _GNUC_VER < 403
@@ -508,6 +509,7 @@
#if _GNUC_VER < 404
#define _LIBCPP_HAS_NO_DECLTYPE
#define _LIBCPP_HAS_NO_DELETED_FUNCTIONS
+#define _LIBCPP_HAS_NO_TRAILING_RETURN
#define _LIBCPP_HAS_NO_UNICODE_CHARS
#define _LIBCPP_HAS_NO_VARIADICS
#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
diff --git a/include/atomic b/include/atomic
index b5d5a27..abec2a0 100644
--- a/include/atomic
+++ b/include/atomic
@@ -552,6 +552,12 @@
namespace __gcc_atomic {
template <typename _Tp>
struct __gcc_atomic_t {
+
+#if _GNUC_VER >= 501
+ static_assert(is_trivially_copyable<_Tp>::value,
+ "std::atomic<Tp> requires that 'Tp' be a trivially copyable type");
+#endif
+
_LIBCPP_INLINE_VISIBILITY
#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
__gcc_atomic_t() _NOEXCEPT = default;