From 61ccaf6ddd923e80358b96d59e78f9475a1ed065 Mon Sep 17 00:00:00 2001 From: Mikhail Maltsev Date: Thu, 22 Feb 2018 09:34:08 +0000 Subject: [PATCH] [libcxx] Do not include the C math.h header before __config Summary: Certain C libraries require configuration macros defined in __config to provide the correct functionality for libc++. This patch ensures that the C header math.h is always included after the __config header. It also adds a Windows-specific #if guard for the case when the C math.h file is included the second time, as suggested by Marshall in https://reviews.llvm.org/rL323490. Fixes PR36382. Reviewers: mclow.lists, EricWF Reviewed By: mclow.lists Subscribers: cfe-commits, pcc, christof, rogfer01 Differential Revision: https://reviews.llvm.org/D43579 llvm-svn: 325760 --- libcxx/include/math.h | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/libcxx/include/math.h b/libcxx/include/math.h index 1476772351c2..cd055caef72d 100644 --- a/libcxx/include/math.h +++ b/libcxx/include/math.h @@ -8,16 +8,6 @@ // //===----------------------------------------------------------------------===// -// This include lives outside the header guard in order to support an MSVC -// extension which allows users to do: -// -// #define _USE_MATH_DEFINES -// #include -// -// and receive the definitions of mathematical constants, even if -// has previously been included. -#include_next - #ifndef _LIBCPP_MATH_H #define _LIBCPP_MATH_H @@ -308,6 +298,8 @@ long double truncl(long double x); #pragma GCC system_header #endif +#include_next + #ifdef __cplusplus // We support including .h headers inside 'extern "C"' contexts, so switch @@ -1494,4 +1486,18 @@ trunc(_A1 __lcpp_x) _NOEXCEPT {return ::trunc((double)__lcpp_x);} #endif // __cplusplus +#else // _LIBCPP_MATH_H + +// This include lives outside the header guard in order to support an MSVC +// extension which allows users to do: +// +// #define _USE_MATH_DEFINES +// #include +// +// and receive the definitions of mathematical constants, even if +// has previously been included. +#if defined(_LIBCPP_MSVCRT) && defined(_USE_MATH_DEFINES) +#include_next +#endif + #endif // _LIBCPP_MATH_H