Index: include/__locale
===================================================================
--- include/__locale
+++ include/__locale
@@ -407,6 +407,32 @@
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_ALPHA
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_XDIGIT
+#elif defined(__ANDROID__)
+    # if !defined(_U)
+    #   if !defined(_CTYPE_U)
+    #    error Bionic header ctype.h does not define either _U nor _CTYPE_U
+    #   endif
+    #   define _U _CTYPE_U
+    #   define _L _CTYPE_L
+    #   define _N _CTYPE_N
+    #   define _S _CTYPE_S
+    #   define _P _CTYPE_P
+    #   define _C _CTYPE_C
+    #   define _X _CTYPE_X
+    #   define _B _CTYPE_B
+    # endif
+typedef unsigned short mask;
+    static const mask space  = _S;
+    static const mask print  = _P | _U | _L | _N | _B;
+    static const mask cntrl  = _C;
+    static const mask upper  = _U;
+    static const mask lower  = _L;
+    static const mask alpha  = _U | _L;
+    static const mask digit  = _N;
+    static const mask punct  = _P;
+    static const mask xdigit = _N | _X;
+    // See src/support/android/locale_android.cpp for details!
+    static const mask blank  = 0x100;
 #else
     typedef unsigned long mask;
     static const mask space  = 1<<0;
Index: src/locale.cpp
===================================================================
--- src/locale.cpp
+++ src/locale.cpp
@@ -52,6 +52,10 @@
 }
 #endif // __cloc_defined
 
+inline locale_t __new_cloc() {
+  return newlocale(LC_ALL_MASK, "C", 0);
+}
+
 namespace {
 
 struct release
@@ -648,8 +652,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__l == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("collate_byname<char>::collate_byname"
                             " failed to construct for " + string(n));
+#else
+        __l = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -659,8 +669,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__l == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("collate_byname<char>::collate_byname"
                             " failed to construct for " + name);
+#else
+        __l = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -700,8 +716,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__l == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("collate_byname<wchar_t>::collate_byname(size_t refs)"
                             " failed to construct for " + string(n));
+#else
+        __l = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -711,8 +733,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__l == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("collate_byname<wchar_t>::collate_byname(size_t refs)"
                             " failed to construct for " + name);
+#else
+        __l = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -806,6 +834,8 @@
 #elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || \
       defined(__NetBSD__)
     return isascii(c) ? ctype<char>::__classic_upper_table()[c] : c;
+#elif defined(__ANDROID__)
+    return isascii(c) ? _toupper_tab_[c + 1] : c;
 #else
     return (isascii(c) && iswlower_l(c, _LIBCPP_GET_C_LOCALE)) ? c-L'a'+L'A' : c;
 #endif
@@ -821,6 +851,8 @@
       defined(__NetBSD__)
         *low = isascii(*low) ? ctype<char>::__classic_upper_table()[*low]
                              : *low;
+#elif defined(__ANDROID__)
+        *low = isascii(*low) ? _toupper_tab_[*low + 1] : *low;
 #else
         *low = (isascii(*low) && islower_l(*low, _LIBCPP_GET_C_LOCALE)) ? (*low-L'a'+L'A') : *low;
 #endif
@@ -835,6 +867,8 @@
 #elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || \
       defined(__NetBSD__)
     return isascii(c) ? ctype<char>::__classic_lower_table()[c] : c;
+#elif defined(__ANDROID__)
+    return isascii(c) ? _tolower_tab_[c + 1] : c;
 #else
     return (isascii(c) && isupper_l(c, _LIBCPP_GET_C_LOCALE)) ? c-L'A'+'a' : c;
 #endif
@@ -850,6 +884,8 @@
       defined(__NetBSD__)
         *low = isascii(*low) ? ctype<char>::__classic_lower_table()[*low]
                              : *low;
+#elif defined(__ANDROID__)
+        *low = isascii(*low) ? _tolower_tab_[*low + 1] : *low;
 #else
         *low = (isascii(*low) && isupper_l(*low, _LIBCPP_GET_C_LOCALE)) ? *low-L'A'+L'a' : *low;
 #endif
@@ -919,6 +955,8 @@
 #elif defined(__GLIBC__) || defined(__EMSCRIPTEN__)
     return isascii(c) ?
       static_cast<char>(__classic_upper_table()[static_cast<unsigned char>(c)]) : c;
+#elif defined(__ANDROID__)
+    return isascii(c) ? _toupper_tab_[c + 1] : c;
 #else
     return (isascii(c) && islower_l(c, _LIBCPP_GET_C_LOCALE)) ? c-'a'+'A' : c;
 #endif
@@ -936,6 +974,8 @@
 #elif defined(__GLIBC__) || defined(__EMSCRIPTEN__)
         *low = isascii(*low) ?
           static_cast<char>(__classic_upper_table()[static_cast<size_t>(*low)]) : *low;
+#elif defined(__ANDROID__)
+        *low = isascii(*low) ? _toupper_tab_[*low + 1] : *low;
 #else
         *low = (isascii(*low) && islower_l(*low, _LIBCPP_GET_C_LOCALE)) ? *low-'a'+'A' : *low;
 #endif
@@ -953,6 +993,8 @@
 #elif defined(__GLIBC__) || defined(__EMSCRIPTEN__)
     return isascii(c) ?
       static_cast<char>(__classic_lower_table()[static_cast<size_t>(c)]) : c;
+#elif defined(__ANDROID__)
+    return isascii(c) ? _tolower_tab_[c + 1] : c;
 #else
     return (isascii(c) && isupper_l(c, _LIBCPP_GET_C_LOCALE)) ? c-'A'+'a' : c;
 #endif
@@ -968,6 +1010,8 @@
         *low = static_cast<char>(__classic_lower_table()[static_cast<unsigned char>(*low)]);
 #elif defined(__GLIBC__) || defined(__EMSCRIPTEN__)
         *low = isascii(*low) ? static_cast<char>(__classic_lower_table()[static_cast<size_t>(*low)]) : *low;
+#elif defined(__ANDROID__)
+        *low = isascii(*low) ? _tolower_tab_[*low + 1] : *low;
 #else
         *low = (isascii(*low) && isupper_l(*low, _LIBCPP_GET_C_LOCALE)) ? *low-'A'+'a' : *low;
 #endif
@@ -1013,7 +1057,12 @@
 extern "C" const int ** __ctype_toupper_loc();
 #endif
 
-#ifdef _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
+#if defined(__ANDROID__)
+// See src/support/android/android_locale.cpp
+extern "C" const unsigned short* const _ctype_android;
+#endif
+
+#if defined(_LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE)
 const ctype<char>::mask*
 ctype<char>::classic_table()  _NOEXCEPT
 {
@@ -1114,6 +1163,8 @@
 #elif defined(_NEWLIB_VERSION)
     // Newlib has a 257-entry table in ctype_.c, where (char)0 starts at [1].
     return _ctype_ + 1;
+#elif defined(__ANDROID__)
+    return _ctype_android;
 #elif defined(_AIX)
     return (const unsigned int *)__lc_ctype_ptr->obj->mask;
 #else
@@ -1174,8 +1225,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__l == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("ctype_byname<char>::ctype_byname"
                             " failed to construct for " + string(name));
+#else
+        __l = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -1185,8 +1242,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__l == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("ctype_byname<char>::ctype_byname"
                             " failed to construct for " + name);
+#else
+        __l = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -1231,8 +1294,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__l == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("ctype_byname<wchar_t>::ctype_byname"
                             " failed to construct for " + string(name));
+#else
+        __l = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -1242,8 +1311,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__l == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("ctype_byname<wchar_t>::ctype_byname"
                             " failed to construct for " + name);
+#else
+        __l = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -1522,8 +1597,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__l == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("codecvt_byname<wchar_t, char, mbstate_t>::codecvt_byname"
                             " failed to construct for " + string(nm));
+#else
+        __l = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -4318,7 +4399,12 @@
 {
     if (strcmp(nm, "C") != 0)
     {
-        __locale_unique_ptr loc(newlocale(LC_ALL_MASK, nm, 0), freelocale);
+        locale_t l = newlocale(LC_ALL_MASK, nm, 0);
+#if defined(__ANDROID__)
+        if (l == 0)
+            l = __new_cloc();
+#endif
+        __locale_unique_ptr loc(l, freelocale);
 #ifndef _LIBCPP_NO_EXCEPTIONS
         if (loc == nullptr)
             throw runtime_error("numpunct_byname<char>::numpunct_byname"
@@ -4361,7 +4447,12 @@
 {
     if (strcmp(nm, "C") != 0)
     {
-        __locale_unique_ptr loc(newlocale(LC_ALL_MASK, nm, 0), freelocale);
+        locale_t l = newlocale(LC_ALL_MASK, nm, 0);
+#if defined(__ANDROID__)
+        if (l == 0)
+            l = __new_cloc();
+#endif
+        __locale_unique_ptr loc(l, freelocale);
 #ifndef _LIBCPP_NO_EXCEPTIONS
         if (loc == nullptr)
             throw runtime_error("numpunct_byname<char>::numpunct_byname"
@@ -4775,8 +4866,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__loc_ == 0)
+    {
+#if !defined(__ANDROID__)
         throw runtime_error("time_get_byname"
                             " failed to construct for " + string(nm));
+#else
+        __loc_ = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -4785,8 +4882,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__loc_ == 0)
+    {
+# if !defined(__ANDROID__)
         throw runtime_error("time_get_byname"
                             " failed to construct for " + nm);
+#else
+        __loc_ = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -5463,8 +5566,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__loc_ == 0)
+    {
+# if !defined(__ANDROID__)
         throw runtime_error("time_put_byname"
                             " failed to construct for " + string(nm));
+#else
+        __loc_ = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -5473,8 +5582,14 @@
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (__loc_ == 0)
+    {
+# if !defined(__ANDROID__)
         throw runtime_error("time_put_byname"
                             " failed to construct for " + nm);
+#else
+        __loc_ = __new_cloc();
+#endif
+    }
 #endif  // _LIBCPP_NO_EXCEPTIONS
 }
 
@@ -5893,7 +6008,12 @@
 moneypunct_byname<char, false>::init(const char* nm)
 {
     typedef moneypunct<char, false> base;
-    __locale_unique_ptr loc(newlocale(LC_ALL_MASK, nm, 0), freelocale);
+    locale_t l = newlocale(LC_ALL_MASK, nm, 0);
+#if defined(__ANDROID__)
+    if (l == 0)
+        l = __new_cloc();
+#endif
+    __locale_unique_ptr loc(l, freelocale);
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (loc == nullptr)
         throw runtime_error("moneypunct_byname"
@@ -5941,7 +6061,12 @@
 moneypunct_byname<char, true>::init(const char* nm)
 {
     typedef moneypunct<char, true> base;
-    __locale_unique_ptr loc(newlocale(LC_ALL_MASK, nm, 0), freelocale);
+    locale_t l = newlocale(LC_ALL_MASK, nm, 0);
+#if defined(__ANDROID__)
+    if (l == 0)
+        l = __new_cloc();
+#endif
+    __locale_unique_ptr loc(l, freelocale);
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (loc == nullptr)
         throw runtime_error("moneypunct_byname"
@@ -6006,7 +6131,12 @@
 moneypunct_byname<wchar_t, false>::init(const char* nm)
 {
     typedef moneypunct<wchar_t, false> base;
-    __locale_unique_ptr loc(newlocale(LC_ALL_MASK, nm, 0), freelocale);
+    locale_t l = newlocale(LC_ALL_MASK, nm, 0);
+#if defined(__ANDROID__)
+    if (l == 0)
+        l = __new_cloc();
+#endif
+    __locale_unique_ptr loc(l, freelocale);
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (loc == nullptr)
         throw runtime_error("moneypunct_byname"
@@ -6089,7 +6219,12 @@
 moneypunct_byname<wchar_t, true>::init(const char* nm)
 {
     typedef moneypunct<wchar_t, true> base;
-    __locale_unique_ptr loc(newlocale(LC_ALL_MASK, nm, 0), freelocale);
+    locale_t l = newlocale(LC_ALL_MASK, nm, 0);
+#if defined(__ANDROID__)
+    if (l == 0)
+        l = __new_cloc();
+#endif
+    __locale_unique_ptr loc(l, freelocale);
 #ifndef _LIBCPP_NO_EXCEPTIONS
     if (loc == nullptr)
         throw runtime_error("moneypunct_byname"
Index: src/support/android/locale_android.cpp
===================================================================
--- /dev/null
+++ src/support/android/locale_android.cpp
@@ -0,0 +1,101 @@
+// -*- C++ -*-
+//===-------------------- support/win32/locale_win32.cpp ------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include <ctype.h>
+
+// Bionic exports the non-standard _ctype_ array in <ctype.h>,
+// unfortunately, cannot be used directly for libc++ because it doesn't
+// have a proper bit-flag for blank characters.
+//
+// Note that the header does define a _B flag (as 0x80), but it
+// is only set on the space (32) character, and used to implement
+// isprint() properly. The implementation of isblank() relies on
+// direct comparisons with 9 and 32 instead.
+//
+// The following is a local copy of the Bionic _ctype_ array that has
+// been modified in the following way:
+//
+//   - It stores 16-bit unsigned values, instead of 8-bit char ones.
+//
+//   - Bit flag _BLANK (0x100) is used to indicate blank characters.
+//     It is only set for indices 9 (TAB) and 32 (SPACE).
+//
+//   - Support signed char properly for indexing.
+
+// Used to tag blank characters, this doesn't appear in <ctype.h> nor
+// the original Bionic _ctype_ array.
+#define _BLANK  0x100
+
+// NOTE: A standalone forward declaration is required to ensure that this
+// variable is properly exported with a C name. In other words, this does
+// _not_ work:
+//
+//  extern "C" {
+//  const char* const _ctype_android = ...;
+//  }
+//
+extern "C" const unsigned short* const _ctype_android;
+
+static const unsigned short ctype_android_tab[256+128] = {
+       /* -128..-1 */
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C, /* 80 */
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C, /* 88 */
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C, /* 90 */
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C, /* 98 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* A0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* A8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* B0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* B8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* C0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* C8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* D0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* D8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* E0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* E8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* F0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* F8 */
+       /* 0..127 */
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C,
+        _C,     _C|_S|_BLANK, _C|_S,  _C|_S,  _C|_S,  _C|_S,  _C,     _C,
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C,
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C,
+  _S|_B|_BLANK, _P,           _P,     _P,     _P,     _P,     _P,     _P,
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P,
+        _N,     _N,           _N,     _N,     _N,     _N,     _N,     _N,
+        _N,     _N,           _P,     _P,     _P,     _P,     _P,     _P,
+        _P,     _U|_X,        _U|_X,  _U|_X,  _U|_X,  _U|_X,  _U|_X,  _U,
+        _U,     _U,           _U,     _U,     _U,     _U,     _U,     _U,
+        _U,     _U,           _U,     _U,     _U,     _U,     _U,     _U,
+        _U,     _U,           _U,     _P,     _P,     _P,     _P,     _P,
+        _P,     _L|_X,        _L|_X,  _L|_X,  _L|_X,  _L|_X,  _L|_X,  _L,
+        _L,     _L,           _L,     _L,     _L,     _L,     _L,     _L,
+        _L,     _L,           _L,     _L,     _L,     _L,     _L,     _L,
+        /* determine printability based on the IS0 8859 8-bit standard */
+        _L,     _L,           _L,     _P,     _P,     _P,     _P,     _C,
+        /* 128..255, same as -128..127 */
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C, /* 80 */
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C, /* 88 */
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C, /* 90 */
+        _C,     _C,           _C,     _C,     _C,     _C,     _C,     _C, /* 98 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* A0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* A8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* B0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* B8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* C0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* C8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* D0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* D8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* E0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* E8 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* F0 */
+        _P,     _P,           _P,     _P,     _P,     _P,     _P,     _P, /* F8 */
+};
+
+const unsigned short* const _ctype_android = ctype_android_tab + 128;