diff --git a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c++locale_internal.h b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c++locale_internal.h
index 3ab6af8..81d72f3 100644
--- a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c++locale_internal.h
+++ b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c++locale_internal.h
@@ -41,6 +41,107 @@
 
 #include <ext/concurrence.h>
 
+#ifdef __CYGWIN__
+typedef locale_t __c_locale;
+#define __locale_t locale_t
+#define __nl_langinfo_l nl_langinfo_l
+#define __strcoll_l strcoll_l
+#define __strftime_l strftime_l
+#define __strtod_l strtod_l
+#define __strtof_l strtof_l
+#define __strtold_l strtold_l
+#define __strxfrm_l strxfrm_l
+#define __newlocale newlocale
+#define __freelocale freelocale
+#define __duplocale duplocale
+#define __uselocale uselocale
+#ifdef _GLIBCXX_USE_WCHAR_T
+#define __iswctype_l iswctype_l
+#define __towlower_l towlower_l
+#define __towupper_l towupper_l
+#define __wcscoll_l wcscoll_l
+#define __wcsftime_l wcsftime_l
+#define __wcsxfrm_l wcsxfrm_l
+#define __wctype_l wctype_l
+#endif
+// monetary
+#define __MON_DECIMAL_POINT _NL_MONETARY_MON_DECIMAL_POINT
+#define __MON_THOUSANDS_SEP _NL_MONETARY_MON_THOUSANDS_SEP
+#define __INT_FRAC_DIGITS _NL_MONETARY_INT_FRAC_DIGITS
+#define __MON_GROUPING _NL_MONETARY_MON_GROUPING
+#define __POSITIVE_SIGN _NL_MONETARY_POSITIVE_SIGN
+#define __NEGATIVE_SIGN _NL_MONETARY_NEGATIVE_SIGN
+#define __INT_CURR_SYMBOL _NL_MONETARY_INT_CURR_SYMBOL
+#define __INT_P_SIGN_POSN _NL_MONETARY_INT_P_SIGN_POSN
+#define __INT_N_SIGN_POSN _NL_MONETARY_INT_N_SIGN_POSN
+#define __INT_P_CS_PRECEDES _NL_MONETARY_INT_P_CS_PRECEDES
+#define __INT_N_CS_PRECEDES _NL_MONETARY_INT_N_CS_PRECEDES
+#define __INT_P_SEP_BY_SPACE _NL_MONETARY_INT_P_SEP_BY_SPACE
+#define __INT_N_SEP_BY_SPACE _NL_MONETARY_INT_N_SEP_BY_SPACE
+#define __CURRENCY_SYMBOL _NL_MONETARY_CURRENCY_SYMBOL
+#define __P_SIGN_POSN _NL_MONETARY_P_SIGN_POSN
+#define __N_SIGN_POSN _NL_MONETARY_N_SIGN_POSN
+#define __P_CS_PRECEDES _NL_MONETARY_P_CS_PRECEDES
+#define __N_CS_PRECEDES _NL_MONETARY_N_CS_PRECEDES
+#define __P_SEP_BY_SPACE _NL_MONETARY_P_SEP_BY_SPACE
+#define __N_SEP_BY_SPACE _NL_MONETARY_N_SEP_BY_SPACE
+#define __FRAC_DIGITS _NL_MONETARY_FRAC_DIGITS
+#define _NL_MONETARY_DECIMAL_POINT_WC _NL_MONETARY_WMON_DECIMAL_POINT
+#define _NL_MONETARY_THOUSANDS_SEP_WC _NL_MONETARY_WMON_THOUSANDS_SEP
+// numeric
+#define DECIMAL_POINT _NL_MONETARY_MON_DECIMAL_POINT // No other appropriate ones.
+#define THOUSANDS_SEP _NL_MONETARY_MON_THOUSANDS_SEP // No other appropriate ones.
+#define GROUPING _NL_NUMERIC_GROUPING
+// time
+#define _NL_WD_FMT _NL_TIME_WD_FMT
+#define _NL_WD_T_FMT _NL_TIME_WD_T_FMT
+#define _NL_WT_FMT _NL_TIME_WT_FMT
+#define _NL_WERA_D_FMT _NL_TIME_WERA_D_FMT
+#define _NL_WERA_D_T_FMT _NL_TIME_WERA_D_T_FMT
+#define _NL_WERA_T_FMT _NL_TIME_WERA_T_FMT
+#define _NL_WAM_STR _NL_TIME_WAM_STR
+#define _NL_WPM_STR _NL_TIME_WPM_STR
+#define _NL_WT_FMT_AMPM _NL_TIME_WT_FMT_AMPM
+#define _NL_WDAY_1 _NL_TIME_WWEEKDAY_1
+#define _NL_WDAY_2 _NL_TIME_WWEEKDAY_2
+#define _NL_WDAY_3 _NL_TIME_WWEEKDAY_3
+#define _NL_WDAY_4 _NL_TIME_WWEEKDAY_4
+#define _NL_WDAY_5 _NL_TIME_WWEEKDAY_5
+#define _NL_WDAY_6 _NL_TIME_WWEEKDAY_6
+#define _NL_WDAY_7 _NL_TIME_WWEEKDAY_7
+#define _NL_WABDAY_1 _NL_TIME_WWDAY_1
+#define _NL_WABDAY_2 _NL_TIME_WWDAY_2
+#define _NL_WABDAY_3 _NL_TIME_WWDAY_3
+#define _NL_WABDAY_4 _NL_TIME_WWDAY_4
+#define _NL_WABDAY_5 _NL_TIME_WWDAY_5
+#define _NL_WABDAY_6 _NL_TIME_WWDAY_6
+#define _NL_WABDAY_7 _NL_TIME_WWDAY_7
+#define _NL_WMON_1 _NL_TIME_WMONTH_1
+#define _NL_WMON_2 _NL_TIME_WMONTH_2
+#define _NL_WMON_3 _NL_TIME_WMONTH_3
+#define _NL_WMON_4 _NL_TIME_WMONTH_4
+#define _NL_WMON_5 _NL_TIME_WMONTH_5
+#define _NL_WMON_6 _NL_TIME_WMONTH_6
+#define _NL_WMON_7 _NL_TIME_WMONTH_7
+#define _NL_WMON_8 _NL_TIME_WMONTH_8
+#define _NL_WMON_9 _NL_TIME_WMONTH_9
+#define _NL_WMON_10 _NL_TIME_WMONTH_10
+#define _NL_WMON_11 _NL_TIME_WMONTH_11
+#define _NL_WMON_12 _NL_TIME_WMONTH_12
+#define _NL_WABMON_1 _NL_TIME_WMON_1
+#define _NL_WABMON_2 _NL_TIME_WMON_2
+#define _NL_WABMON_3 _NL_TIME_WMON_3
+#define _NL_WABMON_4 _NL_TIME_WMON_4
+#define _NL_WABMON_5 _NL_TIME_WMON_5
+#define _NL_WABMON_6 _NL_TIME_WMON_6
+#define _NL_WABMON_7 _NL_TIME_WMON_7
+#define _NL_WABMON_8 _NL_TIME_WMON_8
+#define _NL_WABMON_9 _NL_TIME_WMON_9
+#define _NL_WABMON_10 _NL_TIME_WMON_10
+#define _NL_WABMON_11 _NL_TIME_WMON_11
+#define _NL_WABMON_12 _NL_TIME_WMON_12
+#else // __CYGWIN__
+
 #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2)
 
 extern "C" __typeof(nl_langinfo_l) __nl_langinfo_l;
@@ -67,6 +168,8 @@ extern "C" __typeof(wctype_l) __wctype_l;
 
 #endif // GLIBC 2.3 and later
 
+#endif // __CYGWIN__
+
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
diff --git a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c_locale.cc b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c_locale.cc
index 45437e7..177882c 100644
--- a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c_locale.cc
+++ b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c_locale.cc
@@ -28,6 +28,9 @@
 
 // Written by Benjamin Kosnik <bkoz@redhat.com>
 
+#ifdef __CYGWIN__
+#define _GNU_SOURCE 1
+#endif
 #include <locale>
 #include <stdexcept>
 #include <limits>
diff --git a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c_locale.h b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c_locale.h
index bc24355..6f13e06 100644
--- a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c_locale.h
+++ b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/c_locale.h
@@ -49,7 +49,11 @@ namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
+#ifdef __CYGWIN__
+#define __uselocale uselocale
+#else
   extern "C" __typeof(uselocale) __uselocale;
+#endif
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace
@@ -59,7 +63,11 @@ namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
+#ifdef __CYGWIN__
+  typedef locale_t		__c_locale;
+#else
   typedef __locale_t		__c_locale;
+#endif
 
   // Convert numeric value of type double and long double to string and
   // return length of string.  If vsnprintf is available use it, otherwise
diff --git a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/ctype_members.cc b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/ctype_members.cc
index e7a66f1..ee3c236 100644
--- a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/ctype_members.cc
+++ b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/ctype_members.cc
@@ -32,6 +32,15 @@
 #include <cstdio>
 #include <bits/c++locale_internal.h>
 
+#ifdef __CYGWIN__
+# include <endian.h>
+# if __BYTE_ORDER == __BIG_ENDIAN
+#  define _ISbit(bit)        (1 << (bit))
+# else /* __BYTE_ORDER == __LITTLE_ENDIAN */
+#  define _ISbit(bit)        ((bit) < 8 ? ((1 << (bit)) << 8) : ((1 << (bit)) >> 8))
+# endif
+#endif
+
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION
@@ -45,9 +54,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       {
 	this->_S_destroy_c_locale(this->_M_c_locale_ctype);
 	this->_S_create_c_locale(this->_M_c_locale_ctype, __s);
+#ifndef __CYGWIN__
 	this->_M_toupper = this->_M_c_locale_ctype->__ctype_toupper;
 	this->_M_tolower = this->_M_c_locale_ctype->__ctype_tolower;
 	this->_M_table = this->_M_c_locale_ctype->__ctype_b;
+#endif
       }
   }
 
@@ -94,9 +105,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       case graph:
 	__ret = __wctype_l("graph", _M_c_locale_ctype);
 	break;
+#ifndef __CYGWIN__
       case blank:
 	__ret = __wctype_l("blank", _M_c_locale_ctype);
 	break;
+#endif
       default:
 	__ret = __wmask_type();
       }
diff --git a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/monetary_members.cc b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/monetary_members.cc
index 0b7e0ec..05c4161 100644
--- a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/monetary_members.cc
+++ b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/monetary_members.cc
@@ -596,12 +596,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  setlocale(LC_ALL, __name);
 #endif
 
+#ifdef __CYGWIN__
+	  union { char *__s; wchar_t *__w; } __u;
+	  __u.__s = __nl_langinfo_l(_NL_MONETARY_DECIMAL_POINT_WC, __cloc);
+	  _M_data->_M_decimal_point = *__u.__w;
+
+	  __u.__s = __nl_langinfo_l(_NL_MONETARY_THOUSANDS_SEP_WC, __cloc);
+	  _M_data->_M_thousands_sep = *__u.__w;
+#else
 	  union { char *__s; wchar_t __w; } __u;
 	  __u.__s = __nl_langinfo_l(_NL_MONETARY_DECIMAL_POINT_WC, __cloc);
 	  _M_data->_M_decimal_point = __u.__w;
 
 	  __u.__s = __nl_langinfo_l(_NL_MONETARY_THOUSANDS_SEP_WC, __cloc);
 	  _M_data->_M_thousands_sep = __u.__w;
+#endif
 
 	  // Check for NULL, which implies no fractional digits.
 	  if (_M_data->_M_decimal_point == L'\0')
diff --git a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/numeric_members.cc b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/numeric_members.cc
index 19bf7d1..a793140 100644
--- a/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/numeric_members.cc
+++ b/src/gcc-11.4.0/libstdc++-v3/config/locale/generic/numeric_members.cc
@@ -206,6 +206,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       else
 	{
 	  // Named locale.
+#ifdef __CYGWIN__
+	  union { char *__s; wchar_t *__w; } __u;
+	  __u.__s = __nl_langinfo_l(_NL_NUMERIC_DECIMAL_POINT_WC, __cloc);
+	  _M_data->_M_decimal_point = *__u.__w;
+
+	  __u.__s = __nl_langinfo_l(_NL_NUMERIC_THOUSANDS_SEP_WC, __cloc);
+	  _M_data->_M_thousands_sep = *__u.__w;
+#else
 	  // NB: In the GNU model wchar_t is always 32 bit wide.
 	  union { char *__s; wchar_t __w; } __u;
 	  __u.__s = __nl_langinfo_l(_NL_NUMERIC_DECIMAL_POINT_WC, __cloc);
@@ -213,6 +221,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 	  __u.__s = __nl_langinfo_l(_NL_NUMERIC_THOUSANDS_SEP_WC, __cloc);
 	  _M_data->_M_thousands_sep = __u.__w;
+#endif
 
 	  // Check for NULL, which implies no grouping.
 	  if (_M_data->_M_thousands_sep == L'\0')