Make locale code compile on Linux without GLIBC.

[vkalintiris]

Summary

Most of the #ifdefs in the locale code would check for the existence of
GLIBC or for operating systems other than Linux. This patch considers the
case where GLIBC isn't available on Linux, and allows the libcxx
library to build successfully when using the musl C library (with a
small patch for the extended locale functions strtoll_l() and
strtoull_l()).

[jroelofs]

I don't think it's correct to say that !defined(__GLIBC__) && defined(__linux__) ==> Musl (nor is the converse true). Unfortunately, Musl intentionally doesn't provide that sort of macro [1], so to provide support for Musl in libc++, we need to make note of it at configure-time via something like a _LIBCXX_LIBC_IS_MUSL macro via D13407.

1: http://www.openwall.com/lists/musl/2013/02/08/9

[vkalintiris]

In D13557#262801, @jroelofs wrote:

Unfortunately, Musl intentionally doesn't provide that sort of macro [1], so to provide support for Musl in libc++, we need to make note of it at configure-time via something like a _LIBCXX_LIBC_IS_MUSL macro via D13407.

Agreed. That would be much more elegant. I had to write another patch to test for the existence of *each* extended locale functions during configuration-time. It was generic but an ugly hack. Offering a _LIBCXX_LIBC_IS_MUSL option/macro would make things quite simpler. I'll abandon this review request and I'll wait until D13407 is committed.

include/__locale

return _VSTD::use_facet<_VSTD::collate<_CharT> >(*this).compare(
                                        __y.data(), __y.data() + __y.size()) < 0;
 }
 
 // template <class charT> class ctype
 
 class _LIBCPP_TYPE_VIS ctype_base
 {
 public:
-#ifdef __GLIBC__
+#if defined(__GLIBC__)
     typedef unsigned short mask;
     static const mask space  = _ISspace;
     static const mask print  = _ISprint;
     static const mask cntrl  = _IScntrl;
     static const mask upper  = _ISupper;
     static const mask lower  = _ISlower;
     static const mask alpha  = _ISalpha;
     static const mask digit  = _ISdigit;
#elif defined(_WIN32)
     static const mask xdigit = _HEX;
     static const mask blank  = _BLANK;
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
 #elif defined(__APPLE__) || defined(__FreeBSD__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
 # ifdef __APPLE__
     typedef __uint32_t mask;
 # elif defined(__FreeBSD__)
     typedef unsigned long mask;
-# elif defined(__EMSCRIPTEN__) ||  defined(__NetBSD__)
+# elif defined(__EMSCRIPTEN__) || defined(__linux__) || defined(__NetBSD__)
     typedef unsigned short mask;
 # endif
     static const mask space  = _CTYPE_S;
     static const mask print  = _CTYPE_R;
     static const mask cntrl  = _CTYPE_C;
     static const mask upper  = _CTYPE_U;
     static const mask lower  = _CTYPE_L;
     static const mask alpha  = _CTYPE_A;
#elif defined(_NEWLIB_VERSION)
     static const mask digit  = _N;
     static const mask punct  = _P;
     static const mask xdigit = _X | _N;
     static const mask blank  = _B;
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_ALPHA
 # define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_XDIGIT
 #else
+#if defined(__linux__)
+    typedef unsigned short mask;
+#else
     typedef unsigned long mask;
+#endif
     static const mask space  = 1<<0;
     static const mask print  = 1<<1;
     static const mask cntrl  = 1<<2;
     static const mask upper  = 1<<3;
     static const mask lower  = 1<<4;
     static const mask alpha  = 1<<5;
     static const mask digit  = 1<<6;
     static const mask punct  = 1<<7;

 
 #ifdef _CACHED_RUNES
     static const size_t table_size = _CACHED_RUNES;
 #else
     static const size_t table_size = 256;  // FIXME: Don't hardcode this.
 #endif
     _LIBCPP_ALWAYS_INLINE const mask* table() const  _NOEXCEPT {return __tab_;}
     static const mask* classic_table()  _NOEXCEPT;
-#if defined(__GLIBC__) || defined(__EMSCRIPTEN__)
+#if defined(__GLIBC__) || defined(__linux__) || defined(__EMSCRIPTEN__)
     static const int* __classic_upper_table() _NOEXCEPT;
     static const int* __classic_lower_table() _NOEXCEPT;
 #endif
 #if defined(__NetBSD__)
     static const short* __classic_upper_table() _NOEXCEPT;
     static const short* __classic_lower_table() _NOEXCEPT;
 #endif
 

src/locale.cpp

ctype<wchar_t>::do_scan_not(mask m, const char_type* low, const char_type* high) const
     return low;
 }
 
 wchar_t
 ctype<wchar_t>::do_toupper(char_type c) const
 {
 #ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
     return isascii(c) ? _DefaultRuneLocale.__mapupper[c] : c;
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
+#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || \
+      defined(__linux__) || defined(__NetBSD__)
     return isascii(c) ? ctype<char>::__classic_upper_table()[c] : c;
 #else
     return (isascii(c) && iswlower_l(c, _LIBCPP_GET_C_LOCALE)) ? c-L'a'+L'A' : c;
 #endif
 }
 
 const wchar_t*
 ctype<wchar_t>::do_toupper(char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
 #ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
         *low = isascii(*low) ? _DefaultRuneLocale.__mapupper[*low] : *low;
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
+#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || \
+      defined(__linux__) || defined(__NetBSD__)
         *low = isascii(*low) ? ctype<char>::__classic_upper_table()[*low]
                              : *low;
 #else
         *low = (isascii(*low) && islower_l(*low, _LIBCPP_GET_C_LOCALE)) ? (*low-L'a'+L'A') : *low;
 #endif
     return low;
 }
 
 wchar_t
 ctype<wchar_t>::do_tolower(char_type c) const
 {
 #ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
     return isascii(c) ? _DefaultRuneLocale.__maplower[c] : c;
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
+#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || \
+      defined(__linux__) || defined(__NetBSD__)
     return isascii(c) ? ctype<char>::__classic_lower_table()[c] : c;
 #else
     return (isascii(c) && isupper_l(c, _LIBCPP_GET_C_LOCALE)) ? c-L'A'+'a' : c;
 #endif
 }
 
 const wchar_t*
 ctype<wchar_t>::do_tolower(char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
 #ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
         *low = isascii(*low) ? _DefaultRuneLocale.__maplower[*low] : *low;
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
+#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || \
+      defined(__linux__) || defined(__NetBSD__)
         *low = isascii(*low) ? ctype<char>::__classic_lower_table()[*low]
                              : *low;
 #else
         *low = (isascii(*low) && isupper_l(*low, _LIBCPP_GET_C_LOCALE)) ? *low-L'A'+L'a' : *low;
 #endif
     return low;
 }
 

 char
 ctype<char>::do_toupper(char_type c) const
 {
 #ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
     return isascii(c) ?
       static_cast<char>(_DefaultRuneLocale.__mapupper[static_cast<ptrdiff_t>(c)]) : c;
 #elif defined(__NetBSD__)
     return static_cast<char>(__classic_upper_table()[static_cast<unsigned char>(c)]);
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__)
-    return isascii(c) ? 
+#elif defined(__GLIBC__) || defined(__linux__) || defined(__EMSCRIPTEN__)
+    return isascii(c) ?
       static_cast<char>(__classic_upper_table()[static_cast<unsigned char>(c)]) : c;
 #else
     return (isascii(c) && islower_l(c, _LIBCPP_GET_C_LOCALE)) ? c-'a'+'A' : c;
 #endif
 }
 
 const char*
 ctype<char>::do_toupper(char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
 #ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
         *low = isascii(*low) ?
           static_cast<char>(_DefaultRuneLocale.__mapupper[static_cast<ptrdiff_t>(*low)]) : *low;
 #elif defined(__NetBSD__)
         *low = static_cast<char>(__classic_upper_table()[static_cast<unsigned char>(*low)]);
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__)
+#elif defined(__GLIBC__) || defined(__linux__) || defined(__EMSCRIPTEN__)
         *low = isascii(*low) ?
           static_cast<char>(__classic_upper_table()[static_cast<size_t>(*low)]) : *low;
 #else
         *low = (isascii(*low) && islower_l(*low, _LIBCPP_GET_C_LOCALE)) ? *low-'a'+'A' : *low;
 #endif
     return low;
 }
 
 char
 ctype<char>::do_tolower(char_type c) const
 {
 #ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
     return isascii(c) ?
       static_cast<char>(_DefaultRuneLocale.__maplower[static_cast<ptrdiff_t>(c)]) : c;
 #elif defined(__NetBSD__)
     return static_cast<char>(__classic_lower_table()[static_cast<unsigned char>(c)]);
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
+#elif defined(__GLIBC__) || defined(__linux__) || defined(__EMSCRIPTEN__)
     return isascii(c) ?
       static_cast<char>(__classic_lower_table()[static_cast<size_t>(c)]) : c;
 #else
     return (isascii(c) && isupper_l(c, _LIBCPP_GET_C_LOCALE)) ? c-'A'+'a' : c;
 #endif
 }
 
 const char*
 ctype<char>::do_tolower(char_type* low, const char_type* high) const
 {
     for (; low != high; ++low)
 #ifdef _LIBCPP_HAS_DEFAULTRUNELOCALE
         *low = isascii(*low) ? static_cast<char>(_DefaultRuneLocale.__maplower[static_cast<ptrdiff_t>(*low)]) : *low;
 #elif defined(__NetBSD__)
         *low = static_cast<char>(__classic_lower_table()[static_cast<unsigned char>(*low)]);
-#elif defined(__GLIBC__) || defined(__EMSCRIPTEN__)
+#elif defined(__GLIBC__) || defined(__linux__) || defined(__EMSCRIPTEN__)
         *low = isascii(*low) ? static_cast<char>(__classic_lower_table()[static_cast<size_t>(*low)]) : *low;
 #else
         *low = (isascii(*low) && isupper_l(*low, _LIBCPP_GET_C_LOCALE)) ? *low-'A'+'a' : *low;
 #endif
     return low;
 }
 
 char
ctype<char>::do_narrow(const char_type* low, const char_type* high, char dfault, char* dest) const
     for (; low != high; ++low, ++dest)
         if (isascii(*low))
             *dest = *low;
         else
             *dest = dfault;
     return low;
 }
 
-#ifdef __EMSCRIPTEN__
+#if !defined(__GLIBC__) && (defined(__linux__) || defined(__EMSCRIPTEN__))
 extern "C" const unsigned short ** __ctype_b_loc();
 extern "C" const int ** __ctype_tolower_loc();
 extern "C" const int ** __ctype_toupper_loc();
 #endif
 
 #ifdef _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
 const ctype<char>::mask*
 ctype<char>::classic_table()  _NOEXCEPT

 #elif defined(__GLIBC__)
     return _LIBCPP_GET_C_LOCALE->__ctype_b;
 #elif __sun__
     return __ctype_mask;
 #elif defined(_LIBCPP_MSVCRT) || defined(__MINGW32__)
     return _ctype+1; // internal ctype mask table defined in msvcrt.dll
 // This is assumed to be safe, which is a nonsense assumption because we're
 // going to end up dereferencing it later...
-#elif defined(__EMSCRIPTEN__)
+#elif defined(__linux__) || defined(__EMSCRIPTEN__)
     return *__ctype_b_loc();
 #elif defined(_NEWLIB_VERSION)
     // Newlib has a 257-entry table in ctype_.c, where (char)0 starts at [1].
     return _ctype_ + 1;
 #elif defined(_AIX)
     return (const unsigned int *)__lc_ctype_ptr->obj->mask;
 #else
     // Platform not supported: abort so the person doing the port knows what to

 }
 
 const short*
 ctype<char>::__classic_upper_table() _NOEXCEPT
 {
     return _C_toupper_tab_ + 1;
 }
 
-#elif defined(__EMSCRIPTEN__)
+#elif defined(__linux__) || defined(__EMSCRIPTEN__)
 const int*
 ctype<char>::__classic_lower_table() _NOEXCEPT
 {
     return *__ctype_tolower_loc();
 }
 
 const int*
 ctype<char>::__classic_upper_table() _NOEXCEPT
 {
     return *__ctype_toupper_loc();
 }
-#endif // __GLIBC__ || __EMSCRIPTEN__ || __NETBSD__
+#endif // __GLIBC__ || __NETBSD__ || (__linux__ || __EMSCRIPTEN__)
 
 // template <> class ctype_byname<char>
 
 ctype_byname<char>::ctype_byname(const char* name, size_t refs)
     : ctype<char>(0, false, refs),
       __l(newlocale(LC_ALL_MASK, name, 0))
 {
 #ifndef _LIBCPP_NO_EXCEPTIONS