libcxx: Move #include_next <math.h> out of header guard in wrapper header.
Code on Windows expects to be able to do:
#define _USE_MATH_DEFINES
#include <math.h>
and receive the definitions of mathematical constants, even if <math.h>
has previously been included. To support this scenario, re-include
<math.h> every time the wrapper header is included.
Differential Revision: https://reviews.llvm.org/D42403
llvm-svn: 323490
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 0aa71a4f86b933e728b9bc02c409e4b21f671502
diff --git a/include/math.h b/include/math.h
index 8c30ba8..1476772 100644
--- a/include/math.h
+++ b/include/math.h
@@ -8,6 +8,16 @@
//
//===----------------------------------------------------------------------===//
+// This include lives outside the header guard in order to support an MSVC
+// extension which allows users to do:
+//
+// #define _USE_MATH_DEFINES
+// #include <math.h>
+//
+// and receive the definitions of mathematical constants, even if <math.h>
+// has previously been included.
+#include_next <math.h>
+
#ifndef _LIBCPP_MATH_H
#define _LIBCPP_MATH_H
@@ -298,8 +308,6 @@
#pragma GCC system_header
#endif
-#include_next <math.h>
-
#ifdef __cplusplus
// We support including .h headers inside 'extern "C"' contexts, so switch