[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/algorithm b/libcxx/include/algorithm
index 7144050..9fe0361 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -651,14 +651,16 @@
#include <intrin.h>
#endif
-#include <__undef_min_max>
-
#include <__debug>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+
_LIBCPP_BEGIN_NAMESPACE_STD
// I'd like to replace these with _VSTD::equal_to<void>, but can't because:
@@ -5904,4 +5906,6 @@
_LIBCPP_END_NAMESPACE_STD
+_LIBCPP_POP_MACROS
+
#endif // _LIBCPP_ALGORITHM
