--- libstdc++-v3/config/os/bsd/netbsd/ctype_base.h.orig
+++ libstdc++-v3/config/os/bsd/netbsd/ctype_base.h
@@ -43,9 +43,22 @@
 
     // 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 char      	mask;
 
-#ifndef _CTYPE_U
+#if defined(_CTYPE_BL)
+    typedef unsigned short      mask;
+    static const mask upper     = _CTYPE_U;
+    static const mask lower     = _CTYPE_L;
+    static const mask alpha     = _CTYPE_A;
+    static const mask digit     = _CTYPE_D;
+    static const mask xdigit    = _CTYPE_X;
+    static const mask space     = _CTYPE_S;
+    static const mask print     = _CTYPE_R;
+    static const mask graph     = _CTYPE_G;
+    static const mask cntrl     = _CTYPE_C;
+    static const mask punct     = _CTYPE_P;
+    static const mask alnum     = _CTYPE_A | _CTYPE_D;
+#elif !defined(_CTYPE_U)
+    typedef unsigned char      	mask;
     static const mask upper    	= _U;
     static const mask lower 	= _L;
     static const mask alpha 	= _U | _L;
@@ -58,6 +71,7 @@
     static const mask punct 	= _P;
     static const mask alnum 	= _U | _L | _N;
 #else
+    typedef unsigned char      	mask;
     static const mask upper    	= _CTYPE_U;
     static const mask lower 	= _CTYPE_L;
     static const mask alpha 	= _CTYPE_U | _CTYPE_L;
--- libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc.orig
+++ libstdc++-v3/config/os/bsd/netbsd/ctype_configure_char.cc
@@ -38,11 +38,17 @@
 
 // Information as gleaned from /usr/include/ctype.h
 
+#ifndef _CTYPE_BL
   extern "C" const u_int8_t _C_ctype_[];
+#endif
 
   const ctype_base::mask*
   ctype<char>::classic_table() throw()
+#ifdef _CTYPE_BL
+  { return _C_ctype_tab_ + 1; }
+#else
   { return _C_ctype_ + 1; }
+#endif
 
   ctype<char>::ctype(__c_locale, const mask* __table, bool __del, 
 		     size_t __refs) 
@@ -69,14 +75,14 @@
 
   char
   ctype<char>::do_toupper(char __c) const
-  { return ::toupper((int) __c); }
+  { return ::toupper((int)(unsigned char) __c); }
 
   const char*
   ctype<char>::do_toupper(char* __low, const char* __high) const
   {
     while (__low < __high)
       {
-	*__low = ::toupper((int) *__low);
+	*__low = ::toupper((int)(unsigned char) *__low);
 	++__low;
       }
     return __high;
@@ -84,14 +90,14 @@
 
   char
   ctype<char>::do_tolower(char __c) const
-  { return ::tolower((int) __c); }
+  { return ::tolower((int)(unsigned char) __c); }
 
   const char* 
   ctype<char>::do_tolower(char* __low, const char* __high) const
   {
     while (__low < __high)
       {
-	*__low = ::tolower((int) *__low);
+	*__low = ::tolower((int)(unsigned char) *__low);
 	++__low;
       }
     return __high;
--- libstdc++-v3/config/os/bsd/netbsd/ctype_inline.h.orig
+++ libstdc++-v3/config/os/bsd/netbsd/ctype_inline.h
@@ -48,7 +48,7 @@
   is(const char* __low, const char* __high, mask* __vec) const
   {
     while (__low < __high)
-      *__vec++ = _M_table[*__low++];
+      *__vec++ = _M_table[(unsigned char)*__low++];
     return __high;
   }
 
--- libstdc++-v3/libsupc++/unwind-cxx.h.orig
+++ libstdc++-v3/libsupc++/unwind-cxx.h
@@ -38,6 +38,7 @@
 #include <cxxabi.h>
 
 #ifdef _GLIBCXX_HAVE_SYS_SDT_H
+#include <cstdlib>
 #include <sys/sdt.h>
 /* We only want to use stap probes starting with v3.  Earlier versions
    added too much startup cost.  */
--- libstdc++-v3/configure.host.orig
+++ libstdc++-v3/configure.host
@@ -262,6 +262,9 @@
   freebsd*)
     os_include_dir="os/bsd/freebsd"
     ;;
+  linux-android*)
+    os_include_dir="os/bionic"
+    ;;
   linux-musl*)
     os_include_dir="os/generic"
     ;;
--- libstdc++-v3/config/os/bionic/ctype_base.h.orig
+++ libstdc++-v3/config/os/bionic/ctype_base.h
@@ -38,6 +38,18 @@
     // Non-standard typedefs.
     typedef const int* 		__to_type;
 
+#ifdef _CTYPE_U
+#define _U _CTYPE_U
+#define _L _CTYPE_L
+#define _D _CTYPE_D
+#define _S _CTYPE_S
+#define _P _CTYPE_P
+#define _C _CTYPE_C
+#define _X _CTYPE_X
+#define _B _CTYPE_B
+#define _N _CTYPE_D
+#endif
+
     // 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 char 		mask;
--- libstdc++-v3/src/c++11/futex.cc.orig
+++ libstdc++-v3/src/c++11/futex.cc
@@ -27,7 +27,11 @@
 #if defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1
 #include <chrono>
 #include <climits>
+#ifdef __ANDROID__
+#include <sys/syscall.h>
+#else
 #include <syscall.h>
+#endif
 #include <unistd.h>
 #include <sys/time.h>
 #include <errno.h>
--- libstdc++-v3/src/filesystem/dir.cc.orig
+++ libstdc++-v3/src/filesystem/dir.cc
@@ -147,7 +147,13 @@
 
   int err = std::exchange(errno, 0);
   const auto entp = readdir(dirp);
+#ifdef __ANDROID__
+  int tmperr = errno;
+  errno = err;
+  err = tmperr;
+#else
   std::swap(errno, err);
+#endif
 
   if (entp)
     {