libstdc++: Detect miscompilation of src/c++11/limits.cc

Add a #error directive to ensure that the definitions are not compiled
as C++17, which would prevent them being emitted.

libstdc++-v3/ChangeLog:

	PR libstdc++/98725
	* src/c++11/limits.cc: Fail if __cpp_inline_variables is
	defined.

diff --git a/libstdc++-v3/src/c++11/limits.cc b/libstdc++-v3/src/c++11/limits.cc
index 21d4427f10bfd21581be65367d7312062abde951..585cb8c92db6cabdcd27965b313c32c87f2bf343 100644 (file)
--- a/libstdc++-v3/src/c++11/limits.cc
+++ b/libstdc++-v3/src/c++11/limits.cc
@@ -29,6 +29,10 @@
 // 18.2.1
 //
 
+#if __cpp_inline_variables
+# error This file must be compiled as C++11 or C++14
+#endif
+
 #include <limits>
 
 namespace std _GLIBCXX_VISIBILITY(default)