diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -524,9 +524,6 @@
   __support/musl/xlocale.h
   __support/newlib/xlocale.h
   __support/openbsd/xlocale.h
-  __support/solaris/floatingpoint.h
-  __support/solaris/wchar.h
-  __support/solaris/xlocale.h
   __support/win32/locale_win32.h
   __support/xlocale/__nop_locale_mgmt.h
   __support/xlocale/__posix_l_fallback.h
diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -321,15 +321,6 @@
 #    define _LIBCPP_HAS_OPEN_WITH_WCHAR
 #  endif // defined(_WIN32)
 
-#  ifdef __sun__
-#    include <sys/isa_defs.h>
-#    ifdef _LITTLE_ENDIAN
-#      define _LIBCPP_LITTLE_ENDIAN
-#    else
-#      define _LIBCPP_BIG_ENDIAN
-#    endif
-#  endif // __sun__
-
 #  if defined(_AIX) && !defined(__64BIT__)
 // The size of wchar is 2 byte on 32-bit mode on AIX.
 #    define _LIBCPP_SHORT_WCHAR 1
@@ -374,7 +365,7 @@
 //      When this option is used, the token passed to `std::random_device`'s
 //      constructor *must* be "/dev/urandom" -- anything else is an error.
 #  if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) ||                     \
-      defined(__DragonFly__) || defined(__sun__)
+      defined(__DragonFly__)
 #    define _LIBCPP_USING_ARC4_RANDOM
 #  elif defined(__wasi__) || defined(__EMSCRIPTEN__)
 #    define _LIBCPP_USING_GETENTROPY
@@ -695,8 +686,7 @@
 #    define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)
 #  endif // _LIBCPP_CXX03_LANG
 
-#  if defined(__APPLE__) || defined(__FreeBSD__) || defined(_LIBCPP_MSVCRT_LIKE) || defined(__sun__) ||                \
-      defined(__NetBSD__)
+#  if defined(__APPLE__) || defined(__FreeBSD__) || defined(_LIBCPP_MSVCRT_LIKE) || defined(__NetBSD__)
 #    define _LIBCPP_LOCALE__L_EXTENSIONS 1
 #  endif
 
@@ -724,7 +714,7 @@
 #    define _LIBCPP_HAS_DEFAULTRUNELOCALE
 #  endif
 
-#  if defined(__APPLE__) || defined(__FreeBSD__) || defined(__sun__)
+#  if defined(__APPLE__) || defined(__FreeBSD__)
 #    define _LIBCPP_WCTYPE_IS_MASK
 #  endif
 
@@ -881,7 +871,6 @@
         defined(__linux__) ||                                                                                          \
         defined(__GNU__) ||                                                                                            \
         defined(__APPLE__) ||                                                                                          \
-        defined(__sun__) ||                                                                                            \
         defined(__MVS__) ||                                                                                            \
         defined(_AIX) ||                                                                                               \
         defined(__EMSCRIPTEN__)
diff --git a/libcxx/include/__locale b/libcxx/include/__locale
--- a/libcxx/include/__locale
+++ b/libcxx/include/__locale
@@ -28,9 +28,6 @@
 # include <__support/ibm/xlocale.h>
 #elif defined(__ANDROID__)
 # include <__support/android/locale_bionic.h>
-#elif defined(__sun__)
-# include <__support/solaris/xlocale.h>
-# include <xlocale.h>
 #elif defined(_NEWLIB_VERSION)
 # include <__support/newlib/xlocale.h>
 #elif defined(__OpenBSD__)
@@ -482,7 +479,7 @@
     static const mask blank  = _CTYPE_B;
     static const mask __regex_word = 0x80;
 # endif
-#elif defined(__sun__) || defined(_AIX)
+#elif defined(_AIX)
     typedef unsigned int mask;
     static const mask space  = _ISSPACE;
     static const mask print  = _ISPRINT;
@@ -494,11 +491,7 @@
     static const mask punct  = _ISPUNCT;
     static const mask xdigit = _ISXDIGIT;
     static const mask blank  = _ISBLANK;
-# if defined(_AIX)
     static const mask __regex_word = 0x8000;
-# else
-    static const mask __regex_word = 0x80;
-# endif
 #elif defined(_NEWLIB_VERSION)
     // Same type as Newlib's _ctype_ array in newlib/libc/include/ctype.h.
     typedef char mask;
diff --git a/libcxx/include/math.h b/libcxx/include/math.h
--- a/libcxx/include/math.h
+++ b/libcxx/include/math.h
@@ -538,10 +538,8 @@
 
 // acos
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       acos(float __x) _NOEXCEPT       {return ::acosf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double acos(long double __x) _NOEXCEPT {return ::acosl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -550,10 +548,8 @@
 
 // asin
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       asin(float __x) _NOEXCEPT       {return ::asinf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double asin(long double __x) _NOEXCEPT {return ::asinl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -562,10 +558,8 @@
 
 // atan
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       atan(float __x) _NOEXCEPT       {return ::atanf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double atan(long double __x) _NOEXCEPT {return ::atanl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -574,10 +568,8 @@
 
 // atan2
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       atan2(float __y, float __x) _NOEXCEPT             {return ::atan2f(__y, __x);}
 inline _LIBCPP_HIDE_FROM_ABI long double atan2(long double __y, long double __x) _NOEXCEPT {return ::atan2l(__y, __x);}
-#    endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -597,10 +589,8 @@
 
 // ceil
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       ceil(float __x) _NOEXCEPT       {return ::ceilf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double ceil(long double __x) _NOEXCEPT {return ::ceill(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -609,10 +599,8 @@
 
 // cos
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       cos(float __x) _NOEXCEPT       {return ::cosf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double cos(long double __x) _NOEXCEPT {return ::cosl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -621,10 +609,8 @@
 
 // cosh
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       cosh(float __x) _NOEXCEPT       {return ::coshf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double cosh(long double __x) _NOEXCEPT {return ::coshl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -633,10 +619,8 @@
 
 // exp
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       exp(float __x) _NOEXCEPT       {return ::expf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double exp(long double __x) _NOEXCEPT {return ::expl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -645,10 +629,8 @@
 
 // fabs
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       fabs(float __x) _NOEXCEPT       {return ::fabsf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double fabs(long double __x) _NOEXCEPT {return ::fabsl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -657,10 +639,8 @@
 
 // floor
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       floor(float __x) _NOEXCEPT       {return ::floorf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double floor(long double __x) _NOEXCEPT {return ::floorl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -669,10 +649,8 @@
 
 // fmod
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       fmod(float __x, float __y) _NOEXCEPT             {return ::fmodf(__x, __y);}
 inline _LIBCPP_HIDE_FROM_ABI long double fmod(long double __x, long double __y) _NOEXCEPT {return ::fmodl(__x, __y);}
-#    endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -692,10 +670,8 @@
 
 // frexp
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       frexp(float __x, int* __e) _NOEXCEPT       {return ::frexpf(__x, __e);}
 inline _LIBCPP_HIDE_FROM_ABI long double frexp(long double __x, int* __e) _NOEXCEPT {return ::frexpl(__x, __e);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -704,10 +680,8 @@
 
 // ldexp
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       ldexp(float __x, int __e) _NOEXCEPT       {return ::ldexpf(__x, __e);}
 inline _LIBCPP_HIDE_FROM_ABI long double ldexp(long double __x, int __e) _NOEXCEPT {return ::ldexpl(__x, __e);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -716,10 +690,8 @@
 
 // log
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       log(float __x) _NOEXCEPT       {return ::logf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double log(long double __x) _NOEXCEPT {return ::logl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -728,10 +700,8 @@
 
 // log10
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       log10(float __x) _NOEXCEPT       {return ::log10f(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double log10(long double __x) _NOEXCEPT {return ::log10l(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -740,17 +710,13 @@
 
 // modf
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       modf(float __x, float* __y) _NOEXCEPT             {return ::modff(__x, __y);}
 inline _LIBCPP_HIDE_FROM_ABI long double modf(long double __x, long double* __y) _NOEXCEPT {return ::modfl(__x, __y);}
-#    endif
 
 // pow
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       pow(float __x, float __y) _NOEXCEPT             {return ::powf(__x, __y);}
 inline _LIBCPP_HIDE_FROM_ABI long double pow(long double __x, long double __y) _NOEXCEPT {return ::powl(__x, __y);}
-#    endif
 
 template <class _A1, class _A2>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -770,7 +736,6 @@
 
 // sin
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       sin(float __x) _NOEXCEPT       {return ::sinf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double sin(long double __x) _NOEXCEPT {return ::sinl(__x);}
 #endif
@@ -782,10 +747,8 @@
 
 // sinh
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       sinh(float __x) _NOEXCEPT       {return ::sinhf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double sinh(long double __x) _NOEXCEPT {return ::sinhl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -794,10 +757,8 @@
 
 // sqrt
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       sqrt(float __x) _NOEXCEPT       {return ::sqrtf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double sqrt(long double __x) _NOEXCEPT {return ::sqrtl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -806,10 +767,8 @@
 
 // tan
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       tan(float __x) _NOEXCEPT       {return ::tanf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double tan(long double __x) _NOEXCEPT {return ::tanl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
@@ -818,10 +777,8 @@
 
 // tanh
 
-#    if !defined(__sun__)
 inline _LIBCPP_HIDE_FROM_ABI float       tanh(float __x) _NOEXCEPT       {return ::tanhf(__x);}
 inline _LIBCPP_HIDE_FROM_ABI long double tanh(long double __x) _NOEXCEPT {return ::tanhl(__x);}
-#    endif
 
 template <class _A1>
 inline _LIBCPP_HIDE_FROM_ABI
diff --git a/libcxx/include/stdlib.h b/libcxx/include/stdlib.h
--- a/libcxx/include/stdlib.h
+++ b/libcxx/include/stdlib.h
@@ -109,16 +109,15 @@
 #endif
 
 // MSVCRT already has the correct prototype in <stdlib.h> if __cplusplus is defined
-#if !defined(_LIBCPP_MSVCRT) && !defined(__sun__)
+#if !defined(_LIBCPP_MSVCRT)
 inline _LIBCPP_INLINE_VISIBILITY long abs(long __x) _NOEXCEPT {
   return __builtin_labs(__x);
 }
 inline _LIBCPP_INLINE_VISIBILITY long long abs(long long __x) _NOEXCEPT {
   return __builtin_llabs(__x);
 }
-#endif // !defined(_LIBCPP_MSVCRT) && !defined(__sun__)
+#endif // !defined(_LIBCPP_MSVCRT)
 
-#if !defined(__sun__)
 inline _LIBCPP_INLINE_VISIBILITY float abs(float __lcpp_x) _NOEXCEPT {
   return __builtin_fabsf(__lcpp_x); // Use builtins to prevent needing math.h
 }
@@ -131,7 +130,6 @@
 abs(long double __lcpp_x) _NOEXCEPT {
   return __builtin_fabsl(__lcpp_x);
 }
-#endif // !defined(__sun__)
 
 // div
 
@@ -146,7 +144,7 @@
 #endif
 
 // MSVCRT already has the correct prototype in <stdlib.h> if __cplusplus is defined
-#if !defined(_LIBCPP_MSVCRT) && !defined(__sun__)
+#if !defined(_LIBCPP_MSVCRT)
 inline _LIBCPP_INLINE_VISIBILITY ldiv_t div(long __x, long __y) _NOEXCEPT {
   return ::ldiv(__x, __y);
 }
@@ -156,7 +154,7 @@
   return ::lldiv(__x, __y);
 }
 #endif
-#endif // _LIBCPP_MSVCRT / __sun__
+#endif // _LIBCPP_MSVCRT
 } // extern "C++"
 #endif // __cplusplus
 
diff --git a/libcxx/include/string.h b/libcxx/include/string.h
--- a/libcxx/include/string.h
+++ b/libcxx/include/string.h
@@ -64,8 +64,7 @@
 // MSVCRT, GNU libc and its derivates may already have the correct prototype in
 // <string.h>. This macro can be defined by users if their C library provides
 // the right signature.
-#if defined(__CORRECT_ISO_CPP_STRING_H_PROTO) || defined(_LIBCPP_MSVCRT) || \
-    defined(__sun__) || defined(_STRING_H_CPLUSPLUS_98_CONFORMANCE_)
+#if defined(__CORRECT_ISO_CPP_STRING_H_PROTO) || defined(_LIBCPP_MSVCRT) || defined(_STRING_H_CPLUSPLUS_98_CONFORMANCE_)
 #define _LIBCPP_STRING_H_HAS_CONST_OVERLOADS
 #endif
 
diff --git a/libcxx/src/CMakeLists.txt b/libcxx/src/CMakeLists.txt
--- a/libcxx/src/CMakeLists.txt
+++ b/libcxx/src/CMakeLists.txt
@@ -101,12 +101,6 @@
       support/win32/thread_win32.cpp
       )
   endif()
-elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "SunOS")
-  list(APPEND LIBCXX_SOURCES
-    support/solaris/mbsnrtowcs.inc
-    support/solaris/wcsnrtombs.inc
-    support/solaris/xlocale.cpp
-    )
 elseif(ZOS)
   list(APPEND LIBCXX_SOURCES
     support/ibm/mbsnrtowcs.cpp
diff --git a/libcxx/src/include/config_elast.h b/libcxx/src/include/config_elast.h
--- a/libcxx/src/include/config_elast.h
+++ b/libcxx/src/include/config_elast.h
@@ -35,8 +35,6 @@
 #define _LIBCPP_ELAST 4095
 #elif defined(__APPLE__)
 // No _LIBCPP_ELAST needed on Apple
-#elif defined(__sun__)
-#define _LIBCPP_ELAST ESTALE
 #elif defined(__MVS__)
 #define _LIBCPP_ELAST 1160
 #elif defined(_LIBCPP_MSVCRT_LIKE)
diff --git a/libcxx/src/locale.cpp b/libcxx/src/locale.cpp
--- a/libcxx/src/locale.cpp
+++ b/libcxx/src/locale.cpp
@@ -6,12 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// On Solaris, we need to define something to make the C99 parts of localeconv
-// visible.
-#ifdef __sun__
-#define _LCONV_C99
-#endif
-
 #include <__utility/unreachable.h>
 #include <algorithm>
 #include <clocale>
@@ -1189,8 +1183,6 @@
     return _C_ctype_tab_ + 1;
 #elif defined(__GLIBC__)
     return _LIBCPP_GET_C_LOCALE->__ctype_b;
-#elif defined(__sun__)
-    return __ctype_mask;
 #elif defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
     return __pctype_func();
 #elif defined(__EMSCRIPTEN__)
@@ -1411,10 +1403,8 @@
             if (iswxdigit_l(ch, __l_))
                 *vec |= xdigit;
 #endif
-#if !defined(__sun__)
             if (iswblank_l(ch, __l_))
                 *vec |= blank;
-#endif
         }
     }
     return low;
diff --git a/libcxx/src/random.cpp b/libcxx/src/random.cpp
--- a/libcxx/src/random.cpp
+++ b/libcxx/src/random.cpp
@@ -17,10 +17,6 @@
 #include <random>
 #include <system_error>
 
-#if defined(__sun__)
-#   define rename solaris_headers_are_broken
-#endif // defined(__sun__)
-
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/libcxx/src/support/solaris/README b/libcxx/src/support/solaris/README
deleted file mode 100644
--- a/libcxx/src/support/solaris/README
+++ /dev/null
@@ -1,4 +0,0 @@
-This directory contains a partial implementation of the xlocale APIs for
-Solaris.  Some portions are lifted from FreeBSD libc, and so are covered by a
-2-clause BSD license instead of the MIT/UUIC license that the rest of libc++ is
-distributed under.
diff --git a/libcxx/src/support/solaris/mbsnrtowcs.inc b/libcxx/src/support/solaris/mbsnrtowcs.inc
deleted file mode 100644
--- a/libcxx/src/support/solaris/mbsnrtowcs.inc
+++ /dev/null
@@ -1,76 +0,0 @@
-
-
-/*-
- * As noted in the source, some portions of this implementation are copied from
- * FreeBSD libc.  These are covered by the following copyright:
- *
- * Copyright (c) 2002-2004 Tim J. Robbins.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-size_t
-mbsnrtowcs_l(wchar_t * __restrict dst, const char ** __restrict src,
-    size_t nms, size_t len, mbstate_t * __restrict ps, locale_t loc)
-{
-  const char *s;
-  size_t nchr;
-  wchar_t wc;
-  size_t nb;
-  FIX_LOCALE(loc);
-
-  s = *src;
-  nchr = 0;
-
-  if (dst == NULL) {
-    for (;;) {
-      if ((nb = mbrtowc_l(&wc, s, nms, ps, loc)) == (size_t)-1)
-        /* Invalid sequence - mbrtowc() sets errno. */
-        return ((size_t)-1);
-      else if (nb == 0 || nb == (size_t)-2)
-        return (nchr);
-      s += nb;
-      nms -= nb;
-      nchr++;
-    }
-    /*NOTREACHED*/
-  }
-
-  while (len-- > 0) {
-    if ((nb = mbrtowc_l(dst, s, nms, ps, loc)) == (size_t)-1) {
-      *src = s;
-      return ((size_t)-1);
-    } else if (nb == (size_t)-2) {
-      *src = s + nms;
-      return (nchr);
-    } else if (nb == 0) {
-      *src = NULL;
-      return (nchr);
-    }
-    s += nb;
-    nms -= nb;
-    nchr++;
-    dst++;
-  }
-  *src = s;
-  return (nchr);
-}
diff --git a/libcxx/src/support/solaris/wcsnrtombs.inc b/libcxx/src/support/solaris/wcsnrtombs.inc
deleted file mode 100644
--- a/libcxx/src/support/solaris/wcsnrtombs.inc
+++ /dev/null
@@ -1,92 +0,0 @@
-/*-
- * Copyright (c) 2002-2004 Tim J. Robbins.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-
-size_t
-wcsnrtombs_l(char * __restrict dst, const wchar_t ** __restrict src,
-    size_t nwc, size_t len, mbstate_t * __restrict ps, locale_t loc)
-{
-  FIX_LOCALE(loc);
-  mbstate_t mbsbak;
-  char buf[MB_CUR_MAX_L(loc)];
-  const wchar_t *s;
-  size_t nbytes;
-  size_t nb;
-
-  s = *src;
-  nbytes = 0;
-
-  if (dst == NULL) {
-    while (nwc-- > 0) {
-      if ((nb = wcrtomb_l(buf, *s, ps, loc)) == (size_t)-1)
-        /* Invalid character - wcrtomb() sets errno. */
-        return ((size_t)-1);
-      else if (*s == L'\0')
-        return (nbytes + nb - 1);
-      s++;
-      nbytes += nb;
-    }
-    return (nbytes);
-  }
-
-  while (len > 0 && nwc-- > 0) {
-    if (len > (size_t)MB_CUR_MAX_L(loc)) {
-      /* Enough space to translate in-place. */
-      if ((nb = wcrtomb_l(dst, *s, ps, loc)) == (size_t)-1) {
-        *src = s;
-        return ((size_t)-1);
-      }
-    } else {
-      /*
-       * May not be enough space; use temp. buffer.
-       *
-       * We need to save a copy of the conversion state
-       * here so we can restore it if the multibyte
-       * character is too long for the buffer.
-       */
-      mbsbak = *ps;
-      if ((nb = wcrtomb_l(buf, *s, ps, loc)) == (size_t)-1) {
-        *src = s;
-        return ((size_t)-1);
-      }
-      if (nb > (int)len) {
-        /* MB sequence for character won't fit. */
-        *ps = mbsbak;
-        break;
-      }
-      memcpy(dst, buf, nb);
-    }
-    if (*s == L'\0') {
-      *src = NULL;
-      return (nbytes + nb - 1);
-    }
-    s++;
-    dst += nb;
-    len -= nb;
-    nbytes += nb;
-  }
-  *src = s;
-  return (nbytes);
-}
diff --git a/libcxx/src/support/solaris/xlocale.cpp b/libcxx/src/support/solaris/xlocale.cpp
deleted file mode 100644
--- a/libcxx/src/support/solaris/xlocale.cpp
+++ /dev/null
@@ -1,68 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifdef __sun__
-
-#include "__support/solaris/xlocale.h"
-#include <stdarg.h>
-#include <stdio.h>
-#include <sys/localedef.h>
-
-extern "C" {
-
-int isxdigit_l(int __c, locale_t __l) {
-    return isxdigit(__c);
-}
-
-int iswxdigit_l(wint_t __c, locale_t __l) {
-    return isxdigit(__c);
-}
-
-// FIXME: This disregards the locale, which is Very Wrong
-#define vsnprintf_l(__s, __n, __l, __format, __va)  \
-    vsnprintf(__s, __n, __format, __va)
-
-int snprintf_l(char *__s, size_t __n, locale_t __l, const char *__format, ...)
-{
-  va_list __va;
-  va_start(__va, __format);
-  int __res = vsnprintf_l(__s, __n , __l, __format, __va);
-  va_end(__va);
-  return __res;
-}
-
-int asprintf_l(char **__s, locale_t __l, const char *__format, ...) {
-  va_list __va;
-  va_start(__va, __format);
-  // FIXME:
-  int __res = vasprintf(__s, __format, __va);
-  va_end(__va);
-  return __res;
-}
-
-int sscanf_l(const char *__s, locale_t __l, const char *__format, ...) {
-  va_list __va;
-  va_start(__va, __format);
-  // FIXME:
-  int __res = vsscanf(__s, __format, __va);
-  va_end(__va);
-  return __res;
-}
-
-size_t mbrtowc_l(wchar_t *__pwc, const char *__pmb,
-                 size_t __max, mbstate_t *__ps, locale_t __loc) {
-  return mbrtowc(__pwc, __pmb, __max, __ps);
-}
-
-struct lconv *localeconv_l(locale_t __l) {
-  return localeconv();
-}
-
-};
-
-#endif // __sun__