[Libc++] Use #pragma push_macro/pop_macro to better handle min/max on Windows
Summary:
This patch improves how libc++ handles min/max macros within the headers. Previously libc++ would undef them and emit a warning.
This patch changes libc++ to use `#pragma push_macro` to save the macro before undefining it, and `#pragma pop_macro` to restore the macros and the end of the header.
Reviewers: mclow.lists, bcraig, compnerd, EricWF
Reviewed By: EricWF
Subscribers: cfe-commits, krytarowski
Differential Revision: https://reviews.llvm.org/D33080
llvm-svn: 304357
diff --git a/libcxx/include/bitset b/libcxx/include/bitset
index b49c93c..583122f 100644
--- a/libcxx/include/bitset
+++ b/libcxx/include/bitset
@@ -113,10 +113,6 @@
*/
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
#include <__config>
#include <__bit_reference>
#include <cstddef>
@@ -126,7 +122,13 @@
#include <iosfwd>
#include <__functional_base>
-#include <__undef_min_max>
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
_LIBCPP_BEGIN_NAMESPACE_STD
@@ -1090,4 +1092,6 @@
_LIBCPP_END_NAMESPACE_STD
+_LIBCPP_POP_MACROS
+
#endif // _LIBCPP_BITSET
