diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index ba5939d9003..dd288cce2ca 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,11 @@
+2022-08-28  Samuel Thibault  <samuel.thibault@ens-lyon.org>
+
+	* config/os/gnu/os_defines.h: New file.
+	* config/os/gnu/ctype_base.h: New file.
+	* config/os/gnu/ctype_configure_char.cc: New file.
+	* config/os/gnu/ctype_inline.h: New file.
+	* configure.host: On gnu* host, use os/gnu instead of os/gnu-linux.
+
 2022-08-27  Patrick Palka  <ppalka@redhat.com>
 
 	* testsuite/20_util/logical_traits/requirements/base_classes.cc: New test.
diff --git a/libstdc++-v3/config/os/gnu/ctype_base.h b/libstdc++-v3/config/os/gnu/ctype_base.h
new file mode 100644
index 00000000000..955146543db
--- /dev/null
+++ b/libstdc++-v3/config/os/gnu/ctype_base.h
@@ -0,0 +1,66 @@
+// Locale support -*- C++ -*-
+
+// Copyright (C) 1997-2022 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file bits/ctype_base.h
+ *  This is an internal header file, included by other library headers.
+ *  Do not attempt to use it directly. @headername{locale}
+ */
+
+//
+// ISO C++ 14882: 22.1  Locales
+//
+
+// Information as gleaned from /usr/include/ctype.h
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+  /// @brief  Base class for ctype.
+  struct ctype_base
+  {
+    // Non-standard typedefs.
+    typedef const int* 		__to_type;
+
+    // NB: Offsets into ctype<char>::_M_table force a particular size
+    // on the mask type. Because of this, we don't use an enum.
+    typedef unsigned short 	mask;
+    static const mask upper    	= _ISupper;
+    static const mask lower 	= _ISlower;
+    static const mask alpha 	= _ISalpha;
+    static const mask digit 	= _ISdigit;
+    static const mask xdigit 	= _ISxdigit;
+    static const mask space 	= _ISspace;
+    static const mask print 	= _ISprint;
+    static const mask graph 	= _ISalpha | _ISdigit | _ISpunct;
+    static const mask cntrl 	= _IScntrl;
+    static const mask punct 	= _ISpunct;
+    static const mask alnum 	= _ISalpha | _ISdigit;
+#if __cplusplus >= 201103L
+    static const mask blank	= _ISblank;
+#endif
+  };
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
diff --git a/libstdc++-v3/config/os/gnu/ctype_configure_char.cc b/libstdc++-v3/config/os/gnu/ctype_configure_char.cc
new file mode 100644
index 00000000000..5a88fc11ab3
--- /dev/null
+++ b/libstdc++-v3/config/os/gnu/ctype_configure_char.cc
@@ -0,0 +1,196 @@
+// Locale support -*- C++ -*-
+
+// Copyright (C) 2011-2022 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file ctype_configure_char.cc */
+
+//
+// ISO C++ 14882: 22.1  Locales
+//
+
+#include <locale>
+#include <cstdlib>
+#include <cstring>
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+// Information as gleaned from /usr/include/ctype.h
+
+#if _GLIBCXX_C_LOCALE_GNU
+  const ctype_base::mask*
+  ctype<char>::classic_table() throw()
+  { return _S_get_c_locale()->__ctype_b; }
+#else
+  const ctype_base::mask*
+  ctype<char>::classic_table() throw()
+  {
+    const ctype_base::mask* __ret;
+    char* __old = setlocale(LC_CTYPE, NULL);
+    char* __sav = NULL;
+    if (__builtin_strcmp(__old, "C"))
+      {
+	const size_t __len = __builtin_strlen(__old) + 1;
+	__sav = new char[__len];
+	__builtin_memcpy(__sav, __old, __len);
+	setlocale(LC_CTYPE, "C");
+      }
+#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2)
+    __ret = *__ctype_b_loc();
+#else
+    __ret = __ctype_b;
+#endif
+    if (__sav)
+      {
+	setlocale(LC_CTYPE, __sav);
+	delete [] __sav;
+      }
+    return __ret;
+  }
+#endif
+
+#if _GLIBCXX_C_LOCALE_GNU
+  ctype<char>::ctype(__c_locale __cloc, const mask* __table, bool __del,
+		     size_t __refs)
+  : facet(__refs), _M_c_locale_ctype(_S_clone_c_locale(__cloc)),
+  _M_del(__table != 0 && __del),
+  _M_toupper(_M_c_locale_ctype->__ctype_toupper),
+  _M_tolower(_M_c_locale_ctype->__ctype_tolower),
+  _M_table(__table ? __table : _M_c_locale_ctype->__ctype_b),
+  _M_widen_ok(0), _M_narrow_ok(0)
+  {
+    __builtin_memset(_M_widen, 0, sizeof(_M_widen));
+    __builtin_memset(_M_narrow, 0, sizeof(_M_narrow));
+  }
+#else
+  ctype<char>::ctype(__c_locale, const mask* __table, bool __del,
+		     size_t __refs)
+  : facet(__refs), _M_c_locale_ctype(_S_get_c_locale()),
+  _M_del(__table != 0 && __del), _M_widen_ok(0), _M_narrow_ok(0)
+  {
+    char* __old = setlocale(LC_CTYPE, NULL);
+    char* __sav = NULL;
+    if (__builtin_strcmp(__old, "C"))
+      {
+	const size_t __len = __builtin_strlen(__old) + 1;
+	__sav = new char[__len];
+	__builtin_memcpy(__sav, __old, __len);
+	setlocale(LC_CTYPE, "C");
+      }
+#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2)
+    _M_toupper = *__ctype_toupper_loc();
+    _M_tolower = *__ctype_tolower_loc();
+    _M_table = __table ? __table : *__ctype_b_loc();
+#else
+    _M_toupper = __ctype_toupper;
+    _M_tolower = __ctype_tolower;
+    _M_table = __table ? __table : __ctype_b;
+#endif
+    if (__sav)
+      {
+	setlocale(LC_CTYPE, __sav);
+	delete [] __sav;
+      }
+    __builtin_memset(_M_widen, 0, sizeof(_M_widen));
+    __builtin_memset(_M_narrow, 0, sizeof(_M_narrow));
+  }
+#endif
+
+#if _GLIBCXX_C_LOCALE_GNU
+  ctype<char>::ctype(const mask* __table, bool __del, size_t __refs)
+  : facet(__refs), _M_c_locale_ctype(_S_get_c_locale()),
+  _M_del(__table != 0 && __del),
+  _M_toupper(_M_c_locale_ctype->__ctype_toupper),
+  _M_tolower(_M_c_locale_ctype->__ctype_tolower),
+  _M_table(__table ? __table : _M_c_locale_ctype->__ctype_b),
+  _M_widen_ok(0), _M_narrow_ok(0)
+  {
+    __builtin_memset(_M_widen, 0, sizeof(_M_widen));
+    __builtin_memset(_M_narrow, 0, sizeof(_M_narrow));
+  }
+#else
+  ctype<char>::ctype(const mask* __table, bool __del, size_t __refs)
+  : facet(__refs), _M_c_locale_ctype(_S_get_c_locale()),
+  _M_del(__table != 0 && __del), _M_widen_ok(0), _M_narrow_ok(0)
+  {
+    char* __old = setlocale(LC_CTYPE, NULL);
+    char* __sav = NULL;
+    if (__builtin_strcmp(__old, "C"))
+      {
+	const size_t __len = __builtin_strlen(__old) + 1;
+	__sav = new char[__len];
+	__builtin_memcpy(__sav, __old, __len);
+	setlocale(LC_CTYPE, "C");
+      }
+#if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2)
+    _M_toupper = *__ctype_toupper_loc();
+    _M_tolower = *__ctype_tolower_loc();
+    _M_table = __table ? __table : *__ctype_b_loc();
+#else
+    _M_toupper = __ctype_toupper;
+    _M_tolower = __ctype_tolower;
+    _M_table = __table ? __table : __ctype_b;
+#endif
+    if (__sav)
+      {
+	setlocale(LC_CTYPE, __sav);
+	delete [] __sav;
+      }
+    __builtin_memset(_M_widen, 0, sizeof(_M_widen));
+    __builtin_memset(_M_narrow, 0, sizeof(_M_narrow));
+  }
+#endif
+
+  char
+  ctype<char>::do_toupper(char __c) const
+  { return _M_toupper[static_cast<unsigned char>(__c)]; }
+
+  const char*
+  ctype<char>::do_toupper(char* __low, const char* __high) const
+  {
+    while (__low < __high)
+      {
+	*__low = _M_toupper[static_cast<unsigned char>(*__low)];
+	++__low;
+      }
+    return __high;
+  }
+
+  char
+  ctype<char>::do_tolower(char __c) const
+  { return _M_tolower[static_cast<unsigned char>(__c)]; }
+
+  const char*
+  ctype<char>::do_tolower(char* __low, const char* __high) const
+  {
+    while (__low < __high)
+      {
+	*__low = _M_tolower[static_cast<unsigned char>(*__low)];
+	++__low;
+      }
+    return __high;
+  }
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
diff --git a/libstdc++-v3/config/os/gnu/ctype_inline.h b/libstdc++-v3/config/os/gnu/ctype_inline.h
new file mode 100644
index 00000000000..af60239382f
--- /dev/null
+++ b/libstdc++-v3/config/os/gnu/ctype_inline.h
@@ -0,0 +1,76 @@
+// Locale support -*- C++ -*-
+
+// Copyright (C) 2000-2022 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file bits/ctype_inline.h
+ *  This is an internal header file, included by other library headers.
+ *  Do not attempt to use it directly. @headername{locale}
+ */
+
+//
+// ISO C++ 14882: 22.1  Locales
+//
+
+// ctype bits to be inlined go here. Non-inlinable (ie virtual do_*)
+// functions go in ctype.cc
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+  bool
+  ctype<char>::
+  is(mask __m, char __c) const
+  { return _M_table[static_cast<unsigned char>(__c)] & __m; }
+
+  const char*
+  ctype<char>::
+  is(const char* __low, const char* __high, mask* __vec) const
+  {
+    while (__low < __high)
+      *__vec++ = _M_table[static_cast<unsigned char>(*__low++)];
+    return __high;
+  }
+
+  const char*
+  ctype<char>::
+  scan_is(mask __m, const char* __low, const char* __high) const
+  {
+    while (__low < __high
+	   && !(_M_table[static_cast<unsigned char>(*__low)] & __m))
+      ++__low;
+    return __low;
+  }
+
+  const char*
+  ctype<char>::
+  scan_not(mask __m, const char* __low, const char* __high) const
+  {
+    while (__low < __high
+	   && (_M_table[static_cast<unsigned char>(*__low)] & __m) != 0)
+      ++__low;
+    return __low;
+  }
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
diff --git a/libstdc++-v3/config/os/gnu/os_defines.h b/libstdc++-v3/config/os/gnu/os_defines.h
new file mode 100644
index 00000000000..b4226d95d28
--- /dev/null
+++ b/libstdc++-v3/config/os/gnu/os_defines.h
@@ -0,0 +1,52 @@
+// Specific definitions for GNU/Hurd  -*- C++ -*-
+
+// Copyright (C) 2000-2022 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+/** @file bits/os_defines.h
+ *  This is an internal header file, included by other library headers.
+ *  Do not attempt to use it directly. @headername{iosfwd}
+ */
+
+#ifndef _GLIBCXX_OS_DEFINES
+#define _GLIBCXX_OS_DEFINES 1
+
+// System-specific #define, typedefs, corrections, etc, go here.  This
+// file will come before all others.
+
+// This keeps isalnum, et al from being propagated as macros.
+#define __NO_CTYPE 1
+
+#include <features.h>
+
+// Provide a declaration for the possibly deprecated gets function, as
+// glibc 2.15 and later does not declare gets for ISO C11 when
+// __GNU_SOURCE is defined.
+#if __GLIBC_PREREQ(2,15) && defined(_GNU_SOURCE)
+# undef _GLIBCXX_HAVE_GETS
+#endif
+
+// Glibc 2.23 removed the obsolete isinf and isnan declarations. Check the
+// version dynamically in case it has changed since libstdc++ was configured.
+#define _GLIBCXX_NO_OBSOLETE_ISINF_ISNAN_DYNAMIC __GLIBC_PREREQ(2,23)
+
+#endif
diff --git a/libstdc++-v3/configure.host b/libstdc++-v3/configure.host
index ec32980aa0d..d03492eb8da 100644
--- a/libstdc++-v3/configure.host
+++ b/libstdc++-v3/configure.host
@@ -258,7 +258,7 @@ case "${host_os}" in
   linux-musl*)
     os_include_dir="os/generic"
     ;;
-  gnu* | linux* | kfreebsd*-gnu | uclinux*)
+  linux* | kfreebsd*-gnu | uclinux*)
     if [ "$uclibc" = "yes" ]; then
       os_include_dir="os/uclibc"
     elif [ "$bionic" = "yes" ]; then
@@ -267,6 +267,9 @@ case "${host_os}" in
       os_include_dir="os/gnu-linux"
     fi
     ;;
+  gnu*)
+    os_include_dir="os/gnu"
+    ;;
   hpux*)
     os_include_dir="os/hpux"
     ;;
