[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
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: a016efb1dcda61e606e527b73791fbacf1bc9c86
diff --git a/include/limits b/include/limits
index 4755c57..675cfc4 100644
--- a/include/limits
+++ b/include/limits
@@ -102,15 +102,8 @@
*/
#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
#include <type_traits>
-#include <__undef_min_max>
-
#if defined(_LIBCPP_COMPILER_MSVC)
#include "support/win32/limits_msvc_win32.h"
#endif // _LIBCPP_MSVCRT
@@ -119,6 +112,14 @@
#include "support/ibm/limits.h"
#endif // __IBMCPP__
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+
_LIBCPP_BEGIN_NAMESPACE_STD
enum float_round_style
@@ -811,4 +812,6 @@
_LIBCPP_END_NAMESPACE_STD
+_LIBCPP_POP_MACROS
+
#endif // _LIBCPP_LIMITS