Reorganize _LIBCPP_LOCALE__L_EXTENSIONS

Instead of checking _LIBCPP_LOCALE_L_EXTENSIONS all over, instead check it
once, and define the various *_l symbols once. The private redirector symbol
names are all prefixed with _libcpp_* so that they won't conflict with user
symbols, and so they won't conflict with future C library symbols. In
particular, glibc likes providing private symbols such as __locale_t, so we
should follow a different naming pattern (like _libcpp_*) to avoid problems
on that front.

Tested on Linux with glibc. Hoping for the best on OSX and the various BSDs.

http://reviews.llvm.org/D17456


git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@263016 91177308-0d34-0410-b5e6-96231b3b80d8

include/__bsd_locale_fallbacks.h

@@ -0,0 +1,138 @@
+// -*- C++ -*-
+//===---------------------- __bsd_locale_fallbacks.h ----------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+// The BSDs have lots of *_l functions.  This file provides reimplementations
+// of those functions for non-BSD platforms.
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_BSD_LOCALE_FALLBACKS_DEFAULTS_H
+#define _LIBCPP_BSD_LOCALE_FALLBACKS_DEFAULTS_H
+
+#include <stdlib.h>
+#include <memory>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+typedef _VSTD::remove_pointer<locale_t>::type __use_locale_struct;
+typedef _VSTD::unique_ptr<__use_locale_struct, decltype(&uselocale)> __locale_raii;
+
+inline _LIBCPP_ALWAYS_INLINE
+decltype(MB_CUR_MAX) __libcpp_mb_cur_max_l(locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return MB_CUR_MAX;
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+wint_t __libcpp_btowc_l(int __c, locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return btowc(__c);
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+int __libcpp_wctob_l(wint_t __c, locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return wctob(__c);
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __libcpp_wcsnrtombs_l(char *__dest, const wchar_t **__src, size_t __nwc,
+                         size_t __len, mbstate_t *__ps, locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return wcsnrtombs(__dest, __src, __nwc, __len, __ps);
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __libcpp_wcrtomb_l(char *__s, wchar_t __wc, mbstate_t *__ps, locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return wcrtomb(__s, __wc, __ps);
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __libcpp_mbsnrtowcs_l(wchar_t * __dest, const char **__src, size_t __nms,
+                      size_t __len, mbstate_t *__ps, locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return mbsnrtowcs(__dest, __src, __nms, __len, __ps);
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __libcpp_mbrtowc_l(wchar_t *__pwc, const char *__s, size_t __n,
+                   mbstate_t *__ps, locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return mbrtowc(__pwc, __s, __n, __ps);
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+int __libcpp_mbtowc_l(wchar_t *__pwc, const char *__pmb, size_t __max, locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return mbtowc(__pwc, __pmb, __max);
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __libcpp_mbrlen_l(const char *__s, size_t __n, mbstate_t *__ps, locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return mbrlen(__s, __n, __ps);
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+lconv *__libcpp_localeconv_l(locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return localeconv();
+}
+
+inline _LIBCPP_ALWAYS_INLINE
+size_t __libcpp_mbsrtowcs_l(wchar_t *__dest, const char **__src, size_t __len,
+                     mbstate_t *__ps, locale_t __l)
+{
+    __locale_raii __current( uselocale(__l), uselocale );
+    return mbsrtowcs(__dest, __src, __len, __ps);
+}
+
+inline
+int __libcpp_snprintf_l(char *__s, size_t __n, locale_t __l, const char *__format, ...) {
+    va_list __va;
+    va_start(__va, __format);
+    __locale_raii __current( uselocale(__l), uselocale );
+    int __res = vsnprintf(__s, __n, __format, __va);
+    va_end(__va);
+    return __res;
+}
+
+inline
+int __libcpp_asprintf_l(char **__s, locale_t __l, const char *__format, ...) {
+    va_list __va;
+    va_start(__va, __format);
+    __locale_raii __current( uselocale(__l), uselocale );
+    int __res = vasprintf(__s, __format, __va);
+    va_end(__va);
+    return __res;
+}
+
+inline
+int __libcpp_sscanf_l(const char *__s, locale_t __l, const char *__format, ...) {
+    va_list __va;
+    va_start(__va, __format);
+    __locale_raii __current( uselocale(__l), uselocale );
+    int __res = vsscanf(__s, __format, __va);
+    va_end(__va);
+    return __res;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_BSD_LOCALE_FALLBACKS_DEFAULTS_H