[libc++] Drop support for CRTs older than VS 2015

LLVM dropped support for Visual Studio versions older than 2015 quite
some time ago, so I consider it safe to drop libc++'s support for older
CRTs. The CRT in Visual Studio 2015 provides a lot of previously missing
functions, so targeting it requires less special casing.

Differential Revision: https://reviews.llvm.org/D31798

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@299743 91177308-0d34-0410-b5e6-96231b3b80d8

include/cmath

@@ -398,7 +398,6 @@ using ::cbrtf;
 using ::copysign;
 using ::copysignf;
 
-#if !(defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) < 14))
 using ::erf;
 using ::erff;
 using ::erfc;
@@ -435,12 +434,10 @@ using ::lrint;
 using ::lrintf;
 using ::lround;
 using ::lroundf;
-#endif // !(defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) < 14))
 
 using ::nan;
 using ::nanf;
 
-#if !(defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) < 14))
 using ::nearbyint;
 using ::nearbyintf;
 using ::nextafter;
@@ -463,7 +460,6 @@ using ::tgamma;
 using ::tgammaf;
 using ::trunc;
 using ::truncf;
-#endif // !(defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) < 14))
 
 using ::acosl;
 using ::asinl;
@@ -495,7 +491,6 @@ using ::cbrtl;
 
 using ::copysignl;
 
-#if !(defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) < 14))
 using ::erfl;
 using ::erfcl;
 using ::exp2l;
@@ -526,7 +521,6 @@ using ::scalblnl;
 using ::scalbnl;
 using ::tgammal;
 using ::truncl;
-#endif // !(defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) < 14))
 
 #if _LIBCPP_STD_VER > 14
 inline _LIBCPP_INLINE_VISIBILITY float       hypot(       float x,       float y,       float z ) { return sqrt(x*x + y*y + z*z); }

include/cstdio

@@ -98,9 +98,6 @@ void perror(const char* s);
 
 #include <__config>
 #include <stdio.h>
-#if defined(_LIBCPP_MSVCRT)
-#include <crtversion.h>
-#endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
@@ -156,8 +153,7 @@ using ::tmpnam;
 
 #ifndef _LIBCPP_HAS_NO_STDIN
 using ::getchar;
-#if _LIBCPP_STD_VER <= 11 && \
-    (!defined(_VC_CRT_MAJOR_VERSION) || _VC_CRT_MAJOR_VERSION < 14)
+#if _LIBCPP_STD_VER <= 11 && !defined(_LIBCPP_MSVCRT)
 using ::gets;
 #endif
 using ::scanf;

include/math.h

@@ -293,9 +293,6 @@ long double    truncl(long double x);
 */
 
 #include <__config>
-#if defined(_LIBCPP_MSVCRT)
-#include <crtversion.h>
-#endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
@@ -333,7 +330,7 @@ signbit(_A1 __lcpp_x) _NOEXCEPT
     return __libcpp_signbit((typename std::__promote<_A1>::type)__lcpp_x);
 }
 
-#elif defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) >= 14)
+#elif defined(_LIBCPP_MSVCRT)
 
 template <typename _A1>
 inline _LIBCPP_INLINE_VISIBILITY
@@ -367,7 +364,7 @@ fpclassify(_A1 __lcpp_x) _NOEXCEPT
     return __libcpp_fpclassify((typename std::__promote<_A1>::type)__lcpp_x);
 }
 
-#elif defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) >= 14)
+#elif defined(_LIBCPP_MSVCRT)
 
 template <typename _A1>
 inline _LIBCPP_INLINE_VISIBILITY
@@ -673,7 +670,7 @@ abs(long double __lcpp_x) _NOEXCEPT {return ::fabsl(__lcpp_x);}
 
 // acos
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       acos(float __lcpp_x) _NOEXCEPT       {return ::acosf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double acos(long double __lcpp_x) _NOEXCEPT {return ::acosl(__lcpp_x);}
 #endif
@@ -685,7 +682,7 @@ acos(_A1 __lcpp_x) _NOEXCEPT {return ::acos((double)__lcpp_x);}
 
 // asin
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       asin(float __lcpp_x) _NOEXCEPT       {return ::asinf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double asin(long double __lcpp_x) _NOEXCEPT {return ::asinl(__lcpp_x);}
 #endif
@@ -697,7 +694,7 @@ asin(_A1 __lcpp_x) _NOEXCEPT {return ::asin((double)__lcpp_x);}
 
 // atan
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       atan(float __lcpp_x) _NOEXCEPT       {return ::atanf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double atan(long double __lcpp_x) _NOEXCEPT {return ::atanl(__lcpp_x);}
 #endif
@@ -709,7 +706,7 @@ atan(_A1 __lcpp_x) _NOEXCEPT {return ::atan((double)__lcpp_x);}
 
 // atan2
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       atan2(float __lcpp_y, float __lcpp_x) _NOEXCEPT             {return ::atan2f(__lcpp_y, __lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double atan2(long double __lcpp_y, long double __lcpp_x) _NOEXCEPT {return ::atan2l(__lcpp_y, __lcpp_x);}
 #endif
@@ -732,7 +729,7 @@ atan2(_A1 __lcpp_y, _A2 __lcpp_x) _NOEXCEPT
 
 // ceil
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       ceil(float __lcpp_x) _NOEXCEPT       {return ::ceilf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double ceil(long double __lcpp_x) _NOEXCEPT {return ::ceill(__lcpp_x);}
 #endif
@@ -744,7 +741,7 @@ ceil(_A1 __lcpp_x) _NOEXCEPT {return ::ceil((double)__lcpp_x);}
 
 // cos
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       cos(float __lcpp_x) _NOEXCEPT       {return ::cosf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double cos(long double __lcpp_x) _NOEXCEPT {return ::cosl(__lcpp_x);}
 #endif
@@ -756,7 +753,7 @@ cos(_A1 __lcpp_x) _NOEXCEPT {return ::cos((double)__lcpp_x);}
 
 // cosh
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       cosh(float __lcpp_x) _NOEXCEPT       {return ::coshf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double cosh(long double __lcpp_x) _NOEXCEPT {return ::coshl(__lcpp_x);}
 #endif
@@ -768,7 +765,7 @@ cosh(_A1 __lcpp_x) _NOEXCEPT {return ::cosh((double)__lcpp_x);}
 
 // exp
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       exp(float __lcpp_x) _NOEXCEPT       {return ::expf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double exp(long double __lcpp_x) _NOEXCEPT {return ::expl(__lcpp_x);}
 #endif
@@ -780,7 +777,7 @@ exp(_A1 __lcpp_x) _NOEXCEPT {return ::exp((double)__lcpp_x);}
 
 // fabs
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       fabs(float __lcpp_x) _NOEXCEPT       {return ::fabsf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double fabs(long double __lcpp_x) _NOEXCEPT {return ::fabsl(__lcpp_x);}
 #endif
@@ -792,7 +789,7 @@ fabs(_A1 __lcpp_x) _NOEXCEPT {return ::fabs((double)__lcpp_x);}
 
 // floor
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       floor(float __lcpp_x) _NOEXCEPT       {return ::floorf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double floor(long double __lcpp_x) _NOEXCEPT {return ::floorl(__lcpp_x);}
 #endif
@@ -804,7 +801,7 @@ floor(_A1 __lcpp_x) _NOEXCEPT {return ::floor((double)__lcpp_x);}
 
 // fmod
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       fmod(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::fmodf(__lcpp_x, __lcpp_y);}
 inline _LIBCPP_INLINE_VISIBILITY long double fmod(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::fmodl(__lcpp_x, __lcpp_y);}
 #endif
@@ -827,7 +824,7 @@ fmod(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
 
 // frexp
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       frexp(float __lcpp_x, int* __lcpp_e) _NOEXCEPT       {return ::frexpf(__lcpp_x, __lcpp_e);}
 inline _LIBCPP_INLINE_VISIBILITY long double frexp(long double __lcpp_x, int* __lcpp_e) _NOEXCEPT {return ::frexpl(__lcpp_x, __lcpp_e);}
 #endif
@@ -839,7 +836,7 @@ frexp(_A1 __lcpp_x, int* __lcpp_e) _NOEXCEPT {return ::frexp((double)__lcpp_x, _
 
 // ldexp
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       ldexp(float __lcpp_x, int __lcpp_e) _NOEXCEPT       {return ::ldexpf(__lcpp_x, __lcpp_e);}
 inline _LIBCPP_INLINE_VISIBILITY long double ldexp(long double __lcpp_x, int __lcpp_e) _NOEXCEPT {return ::ldexpl(__lcpp_x, __lcpp_e);}
 #endif
@@ -851,7 +848,7 @@ ldexp(_A1 __lcpp_x, int __lcpp_e) _NOEXCEPT {return ::ldexp((double)__lcpp_x, __
 
 // log
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       log(float __lcpp_x) _NOEXCEPT       {return ::logf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double log(long double __lcpp_x) _NOEXCEPT {return ::logl(__lcpp_x);}
 #endif
@@ -863,7 +860,7 @@ log(_A1 __lcpp_x) _NOEXCEPT {return ::log((double)__lcpp_x);}
 
 // log10
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       log10(float __lcpp_x) _NOEXCEPT       {return ::log10f(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double log10(long double __lcpp_x) _NOEXCEPT {return ::log10l(__lcpp_x);}
 #endif
@@ -875,14 +872,14 @@ log10(_A1 __lcpp_x) _NOEXCEPT {return ::log10((double)__lcpp_x);}
 
 // modf
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       modf(float __lcpp_x, float* __lcpp_y) _NOEXCEPT             {return ::modff(__lcpp_x, __lcpp_y);}
 inline _LIBCPP_INLINE_VISIBILITY long double modf(long double __lcpp_x, long double* __lcpp_y) _NOEXCEPT {return ::modfl(__lcpp_x, __lcpp_y);}
 #endif
 
 // pow
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       pow(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::powf(__lcpp_x, __lcpp_y);}
 inline _LIBCPP_INLINE_VISIBILITY long double pow(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::powl(__lcpp_x, __lcpp_y);}
 #endif
@@ -905,7 +902,7 @@ pow(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
 
 // sin
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       sin(float __lcpp_x) _NOEXCEPT       {return ::sinf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double sin(long double __lcpp_x) _NOEXCEPT {return ::sinl(__lcpp_x);}
 #endif
@@ -917,7 +914,7 @@ sin(_A1 __lcpp_x) _NOEXCEPT {return ::sin((double)__lcpp_x);}
 
 // sinh
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       sinh(float __lcpp_x) _NOEXCEPT       {return ::sinhf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double sinh(long double __lcpp_x) _NOEXCEPT {return ::sinhl(__lcpp_x);}
 #endif
@@ -929,7 +926,7 @@ sinh(_A1 __lcpp_x) _NOEXCEPT {return ::sinh((double)__lcpp_x);}
 
 // sqrt
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       sqrt(float __lcpp_x) _NOEXCEPT       {return ::sqrtf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double sqrt(long double __lcpp_x) _NOEXCEPT {return ::sqrtl(__lcpp_x);}
 #endif
@@ -941,7 +938,7 @@ sqrt(_A1 __lcpp_x) _NOEXCEPT {return ::sqrt((double)__lcpp_x);}
 
 // tan
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       tan(float __lcpp_x) _NOEXCEPT       {return ::tanf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double tan(long double __lcpp_x) _NOEXCEPT {return ::tanl(__lcpp_x);}
 #endif
@@ -953,7 +950,7 @@ tan(_A1 __lcpp_x) _NOEXCEPT {return ::tan((double)__lcpp_x);}
 
 // tanh
 
-#if !((defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14) || defined(_AIX) || defined(__sun__))
+#if !(defined(_AIX) || defined(__sun__))
 inline _LIBCPP_INLINE_VISIBILITY float       tanh(float __lcpp_x) _NOEXCEPT       {return ::tanhf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double tanh(long double __lcpp_x) _NOEXCEPT {return ::tanhl(__lcpp_x);}
 #endif
@@ -965,7 +962,6 @@ tanh(_A1 __lcpp_x) _NOEXCEPT {return ::tanh((double)__lcpp_x);}
 
 // acosh
 
-#if !(defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14)
 inline _LIBCPP_INLINE_VISIBILITY float       acosh(float __lcpp_x) _NOEXCEPT       {return ::acoshf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double acosh(long double __lcpp_x) _NOEXCEPT {return ::acoshl(__lcpp_x);}
 
@@ -973,11 +969,9 @@ template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 acosh(_A1 __lcpp_x) _NOEXCEPT {return ::acosh((double)__lcpp_x);}
-#endif
 
 // asinh
 
-#if !(defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14)
 inline _LIBCPP_INLINE_VISIBILITY float       asinh(float __lcpp_x) _NOEXCEPT       {return ::asinhf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double asinh(long double __lcpp_x) _NOEXCEPT {return ::asinhl(__lcpp_x);}
 
@@ -985,11 +979,9 @@ template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 asinh(_A1 __lcpp_x) _NOEXCEPT {return ::asinh((double)__lcpp_x);}
-#endif
 
 // atanh
 
-#if !(defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14)
 inline _LIBCPP_INLINE_VISIBILITY float       atanh(float __lcpp_x) _NOEXCEPT       {return ::atanhf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double atanh(long double __lcpp_x) _NOEXCEPT {return ::atanhl(__lcpp_x);}
 
@@ -997,11 +989,9 @@ template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 atanh(_A1 __lcpp_x) _NOEXCEPT {return ::atanh((double)__lcpp_x);}
-#endif
 
 // cbrt
 
-#if !(defined(_LIBCPP_MSVCRT) && (_VC_CRT_MAJOR_VERSION-0) < 14)
 inline _LIBCPP_INLINE_VISIBILITY float       cbrt(float __lcpp_x) _NOEXCEPT       {return ::cbrtf(__lcpp_x);}
 inline _LIBCPP_INLINE_VISIBILITY long double cbrt(long double __lcpp_x) _NOEXCEPT {return ::cbrtl(__lcpp_x);}
 
@@ -1009,11 +999,9 @@ template <class _A1>
 inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 cbrt(_A1 __lcpp_x) _NOEXCEPT {return ::cbrt((double)__lcpp_x);}
-#endif
 
 // copysign
 
-#if !defined(_VC_CRT_MAJOR_VERSION) || (_VC_CRT_MAJOR_VERSION < 12)
 inline _LIBCPP_INLINE_VISIBILITY float copysign(float __lcpp_x,
                                                 float __lcpp_y) _NOEXCEPT {
   return ::copysignf(__lcpp_x, __lcpp_y);
@@ -1022,7 +1010,6 @@ inline _LIBCPP_INLINE_VISIBILITY long double
 copysign(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {
   return ::copysignl(__lcpp_x, __lcpp_y);
 }
-#endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_INLINE_VISIBILITY
@@ -1040,8 +1027,6 @@ copysign(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
     return ::copysign((__result_type)__lcpp_x, (__result_type)__lcpp_y);
 }
 
-#if !(defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) < 14))
-
 // erf
 
 inline _LIBCPP_INLINE_VISIBILITY float       erf(float __lcpp_x) _NOEXCEPT       {return ::erff(__lcpp_x);}
@@ -1424,8 +1409,6 @@ inline _LIBCPP_INLINE_VISIBILITY
 typename std::enable_if<std::is_integral<_A1>::value, double>::type
 trunc(_A1 __lcpp_x) _NOEXCEPT {return ::trunc((double)__lcpp_x);}
 
-#endif // !(defined(_LIBCPP_MSVCRT) && ((_VC_CRT_MAJOR_VERSION-0) < 14))
-
 } // extern "C++"
 
 #endif // __cplusplus

include/support/win32/locale_win32.h

@@ -11,13 +11,6 @@
 #ifndef _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H
 #define _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H
 
-#include <crtversion.h>
-
-#if _VC_CRT_MAJOR_VERSION < 14
-// ctype mask table defined in msvcrt.dll
-extern "C" unsigned short __declspec(dllimport) _ctype[];
-#endif
-
 #include "support/win32/support.h"
 #include "support/win32/locale_mgmt_win32.h"
 #include <stdio.h>

include/support/win32/support.h

@@ -21,9 +21,6 @@
 #if defined(_LIBCPP_COMPILER_MSVC)
 #include <intrin.h>
 #endif
-#if defined(_LIBCPP_MSVCRT)
-#include <crtversion.h>
-#endif
 #define swprintf _snwprintf
 #define vswprintf _vsnwprintf
 
@@ -44,11 +41,6 @@ size_t wcsnrtombs(char *__restrict dst, const wchar_t **__restrict src,
 }
 #endif // __MINGW32__
 
-#if defined(_VC_CRT_MAJOR_VERSION) && _VC_CRT_MAJOR_VERSION < 14
-#define snprintf _snprintf
-#define _Exit _exit
-#endif
-
 #if defined(_LIBCPP_COMPILER_MSVC)
 
 // Bit builtin's make these assumptions when calling _BitScanForward/Reverse

src/locale.cpp

@@ -1109,13 +1109,7 @@ ctype<char>::classic_table()  _NOEXCEPT
 #elif __sun__
     return __ctype_mask;
 #elif defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
-#if _VC_CRT_MAJOR_VERSION < 14
-    // This is assumed to be safe, which is a nonsense assumption because we're
-    // going to end up dereferencing it later...
-    return _ctype+1; // internal ctype mask table defined in msvcrt.dll
-#else
     return __pctype_func();
-#endif
 #elif defined(__EMSCRIPTEN__)
     return *__ctype_b_loc();
 #elif defined(_NEWLIB_VERSION)

src/support/win32/locale_win32.cpp

@@ -13,8 +13,6 @@
 #include <memory>
 #include <type_traits>
 
-#include <crtversion.h>
-
 typedef _VSTD::remove_pointer<locale_t>::type __locale_struct;
 typedef _VSTD::unique_ptr<__locale_struct, decltype(&uselocale)> __locale_raii;
 
@@ -31,9 +29,8 @@ locale_t uselocale( locale_t newloc )
     // uselocale sets the thread's locale by definition, so unconditionally use thread-local locale
     _configthreadlocale( _ENABLE_PER_THREAD_LOCALE );
     // uselocale sets all categories
-#if _VC_CRT_MAJOR_VERSION < 14
-    setlocale( LC_ALL, newloc->locinfo->lc_category[LC_ALL].locale );
-#endif
+    // disable setting locale on Windows temporarily because the structure is opaque (PR31516)
+    //setlocale( LC_ALL, newloc->locinfo->lc_category[LC_ALL].locale );
     // uselocale returns the old locale_t
     return old_locale;
 }