Tested x86_64-linux. Pushed to trunk.
-- >8 --
The r15-1857 change means that <type_traits> is included by <cmath> for
C++17 and up, which breaks code including <math.h> inside an extern "C"
block. Although doing that is not allowed by the C++ standard, there's
lots of existing code which incorrectly thinks it's a good idea and so
we try to support it.
libstdc++-v3/ChangeLog:
PR libstdc++/115797
* include/std/type_traits: Ensure "C++" language linkage.
* testsuite/17_intro/headers/c++2011/linkage.cc: Replace
dg-options with c++11 target selector.
---
libstdc++-v3/include/std/type_traits | 3 +++
libstdc++-v3/testsuite/17_intro/headers/c++2011/linkage.cc | 3 +--
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/libstdc++-v3/include/std/type_traits
b/libstdc++-v3/include/std/type_traits
index a31de2ee4ab..c39a3792537 100644
--- a/libstdc++-v3/include/std/type_traits
+++ b/libstdc++-v3/include/std/type_traits
@@ -62,6 +62,8 @@
#define __glibcxx_want_void_t
#include <bits/version.h>
+extern "C++"
+{
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -4111,6 +4113,7 @@ template<typename _Ret, typename _Fn, typename... _Args>
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
+} // extern "C++"
#endif // C++11
diff --git a/libstdc++-v3/testsuite/17_intro/headers/c++2011/linkage.cc
b/libstdc++-v3/testsuite/17_intro/headers/c++2011/linkage.cc
index c43384efbaa..1825801cec9 100644
--- a/libstdc++-v3/testsuite/17_intro/headers/c++2011/linkage.cc
+++ b/libstdc++-v3/testsuite/17_intro/headers/c++2011/linkage.cc
@@ -15,8 +15,7 @@
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
-// { dg-options "-std=gnu++11" }
-// { dg-do compile }
+// { dg-do compile { target c++11 } }
// libstdc++/69386
--
2.45.2
