[libc++] Use the new locale base API on Linux (#128007)

This follows the lead for what we did on all other platforms.

libcxx/include/CMakeLists.txt

@@ -513,6 +513,7 @@ set(files
   __locale_dir/support/bsd_like.h
   __locale_dir/support/freebsd.h
   __locale_dir/support/fuchsia.h
+  __locale_dir/support/linux.h
   __locale_dir/support/no_locale/characters.h
   __locale_dir/support/no_locale/strtonum.h
   __locale_dir/support/windows.h

libcxx/include/__locale_dir/locale_base_api.h

@@ -119,6 +119,8 @@
 #  include <__locale_dir/support/windows.h>
 #elif defined(__Fuchsia__)
 #  include <__locale_dir/support/fuchsia.h>
+#elif defined(__linux__)
+#  include <__locale_dir/support/linux.h>
 #else
 
 // TODO: This is a temporary definition to bridge between the old way we defined the locale base API

libcxx/include/__locale_dir/support/bsd_like.h

@@ -45,9 +45,9 @@ namespace __locale {
 #define _LIBCPP_ALL_MASK LC_ALL_MASK
 #define _LIBCPP_LC_ALL LC_ALL
 
-using __locale_t = ::locale_t;
+using __locale_t _LIBCPP_NODEBUG = ::locale_t;
 #if defined(_LIBCPP_BUILDING_LIBRARY)
-using __lconv_t = std::lconv;
+using __lconv_t _LIBCPP_NODEBUG = std::lconv;
 
 inline _LIBCPP_HIDE_FROM_ABI __locale_t __newlocale(int __category_mask, const char* __locale, __locale_t __base) {
   return ::newlocale(__category_mask, __locale, __base);

libcxx/include/__locale_dir/support/fuchsia.h

@@ -49,10 +49,10 @@ struct __locale_guard {
 #define _LIBCPP_ALL_MASK LC_ALL_MASK
 #define _LIBCPP_LC_ALL LC_ALL
 
-using __locale_t = locale_t;
+using __locale_t _LIBCPP_NODEBUG = locale_t;
 
 #if defined(_LIBCPP_BUILDING_LIBRARY)
-using __lconv_t = std::lconv;
+using __lconv_t _LIBCPP_NODEBUG = std::lconv;
 
 inline _LIBCPP_HIDE_FROM_ABI __locale_t __newlocale(int __category_mask, const char* __name, __locale_t __loc) {
   return ::newlocale(__category_mask, __name, __loc);

libcxx/include/__locale_dir/support/linux.h

@@ -0,0 +1,277 @@
+//===-----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___LOCALE_DIR_SUPPORT_LINUX_H
+#define _LIBCPP___LOCALE_DIR_SUPPORT_LINUX_H
+
+#include <__config>
+#include <__cstddef/size_t.h>
+#include <__std_mbstate_t.h>
+#include <__utility/forward.h>
+#include <clocale> // std::lconv
+#include <cstdio>
+#include <cstdlib>
+#include <ctype.h>
+#include <stdarg.h>
+#include <string.h>
+#include <time.h>
+#if _LIBCPP_HAS_WIDE_CHARACTERS
+#  include <cwchar>
+#  include <wctype.h>
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+namespace __locale {
+
+struct __locale_guard {
+  _LIBCPP_HIDE_FROM_ABI __locale_guard(locale_t& __loc) : __old_loc_(::uselocale(__loc)) {}
+
+  _LIBCPP_HIDE_FROM_ABI ~__locale_guard() {
+    if (__old_loc_)
+      ::uselocale(__old_loc_);
+  }
+
+  locale_t __old_loc_;
+
+  __locale_guard(__locale_guard const&)            = delete;
+  __locale_guard& operator=(__locale_guard const&) = delete;
+};
+
+//
+// Locale management
+//
+#define _LIBCPP_COLLATE_MASK LC_COLLATE_MASK
+#define _LIBCPP_CTYPE_MASK LC_CTYPE_MASK
+#define _LIBCPP_MONETARY_MASK LC_MONETARY_MASK
+#define _LIBCPP_NUMERIC_MASK LC_NUMERIC_MASK
+#define _LIBCPP_TIME_MASK LC_TIME_MASK
+#define _LIBCPP_MESSAGES_MASK LC_MESSAGES_MASK
+#define _LIBCPP_ALL_MASK LC_ALL_MASK
+#define _LIBCPP_LC_ALL LC_ALL
+
+using __locale_t _LIBCPP_NODEBUG = ::locale_t;
+
+#if defined(_LIBCPP_BUILDING_LIBRARY)
+using __lconv_t _LIBCPP_NODEBUG = std::lconv;
+
+inline _LIBCPP_HIDE_FROM_ABI __locale_t __newlocale(int __category_mask, const char* __locale, __locale_t __base) {
+  return ::newlocale(__category_mask, __locale, __base);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI void __freelocale(__locale_t __loc) { ::freelocale(__loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI char* __setlocale(int __category, char const* __locale) {
+  return ::setlocale(__category, __locale);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI __lconv_t* __localeconv(__locale_t& __loc) {
+  __locale_guard __current(__loc);
+  return std::localeconv();
+}
+#endif // _LIBCPP_BUILDING_LIBRARY
+
+//
+// Strtonum functions
+//
+inline _LIBCPP_HIDE_FROM_ABI float __strtof(const char* __nptr, char** __endptr, __locale_t __loc) {
+  return ::strtof_l(__nptr, __endptr, __loc);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI double __strtod(const char* __nptr, char** __endptr, __locale_t __loc) {
+  return ::strtod_l(__nptr, __endptr, __loc);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI long double __strtold(const char* __nptr, char** __endptr, __locale_t __loc) {
+  return ::strtold_l(__nptr, __endptr, __loc);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI long long __strtoll(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
+  return ::strtoll_l(__nptr, __endptr, __base, __loc);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI unsigned long long
+__strtoull(const char* __nptr, char** __endptr, int __base, __locale_t __loc) {
+  return ::strtoull_l(__nptr, __endptr, __base, __loc);
+}
+
+//
+// Character manipulation functions
+//
+#if defined(_LIBCPP_BUILDING_LIBRARY)
+inline _LIBCPP_HIDE_FROM_ABI int __islower(int __c, __locale_t __loc) { return islower_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __isupper(int __c, __locale_t __loc) { return isupper_l(__c, __loc); }
+#endif
+
+inline _LIBCPP_HIDE_FROM_ABI int __isdigit(int __c, __locale_t __loc) { return isdigit_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __isxdigit(int __c, __locale_t __loc) { return isxdigit_l(__c, __loc); }
+
+#if defined(_LIBCPP_BUILDING_LIBRARY)
+inline _LIBCPP_HIDE_FROM_ABI int __toupper(int __c, __locale_t __loc) { return toupper_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __tolower(int __c, __locale_t __loc) { return tolower_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __strcoll(const char* __s1, const char* __s2, __locale_t __loc) {
+  return strcoll_l(__s1, __s2, __loc);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI size_t __strxfrm(char* __dest, const char* __src, size_t __n, __locale_t __loc) {
+  return strxfrm_l(__dest, __src, __n, __loc);
+}
+
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+inline _LIBCPP_HIDE_FROM_ABI int __iswctype(wint_t __c, wctype_t __type, __locale_t __loc) {
+  return iswctype_l(__c, __type, __loc);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswspace(wint_t __c, __locale_t __loc) { return iswspace_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswprint(wint_t __c, __locale_t __loc) { return iswprint_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswcntrl(wint_t __c, __locale_t __loc) { return iswcntrl_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswupper(wint_t __c, __locale_t __loc) { return iswupper_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswlower(wint_t __c, __locale_t __loc) { return iswlower_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswalpha(wint_t __c, __locale_t __loc) { return iswalpha_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswblank(wint_t __c, __locale_t __loc) { return iswblank_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswdigit(wint_t __c, __locale_t __loc) { return iswdigit_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswpunct(wint_t __c, __locale_t __loc) { return iswpunct_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __iswxdigit(wint_t __c, __locale_t __loc) { return iswxdigit_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI wint_t __towupper(wint_t __c, __locale_t __loc) { return towupper_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI wint_t __towlower(wint_t __c, __locale_t __loc) { return towlower_l(__c, __loc); }
+
+inline _LIBCPP_HIDE_FROM_ABI int __wcscoll(const wchar_t* __ws1, const wchar_t* __ws2, __locale_t __loc) {
+  return wcscoll_l(__ws1, __ws2, __loc);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI size_t __wcsxfrm(wchar_t* __dest, const wchar_t* __src, size_t __n, __locale_t __loc) {
+  return wcsxfrm_l(__dest, __src, __n, __loc);
+}
+#  endif // _LIBCPP_HAS_WIDE_CHARACTERS
+
+inline _LIBCPP_HIDE_FROM_ABI size_t
+__strftime(char* __s, size_t __max, const char* __format, const struct tm* __tm, __locale_t __loc) {
+  return strftime_l(__s, __max, __format, __tm, __loc);
+}
+
+//
+// Other functions
+//
+inline _LIBCPP_HIDE_FROM_ABI decltype(MB_CUR_MAX) __mb_len_max(__locale_t __loc) {
+  __locale_guard __current(__loc);
+  return MB_CUR_MAX;
+}
+
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+inline _LIBCPP_HIDE_FROM_ABI wint_t __btowc(int __c, __locale_t __loc) {
+  __locale_guard __current(__loc);
+  return std::btowc(__c);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI int __wctob(wint_t __c, __locale_t __loc) {
+  __locale_guard __current(__loc);
+  return std::wctob(__c);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI size_t
+__wcsnrtombs(char* __dest, const wchar_t** __src, size_t __nwc, size_t __len, mbstate_t* __ps, __locale_t __loc) {
+  __locale_guard __current(__loc);
+  return ::wcsnrtombs(__dest, __src, __nwc, __len, __ps); // non-standard
+}
+
+inline _LIBCPP_HIDE_FROM_ABI size_t __wcrtomb(char* __s, wchar_t __wc, mbstate_t* __ps, __locale_t __loc) {
+  __locale_guard __current(__loc);
+  return std::wcrtomb(__s, __wc, __ps);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI size_t
+__mbsnrtowcs(wchar_t* __dest, const char** __src, size_t __nms, size_t __len, mbstate_t* __ps, __locale_t __loc) {
+  __locale_guard __current(__loc);
+  return ::mbsnrtowcs(__dest, __src, __nms, __len, __ps); // non-standard
+}
+
+inline _LIBCPP_HIDE_FROM_ABI size_t
+__mbrtowc(wchar_t* __pwc, const char* __s, size_t __n, mbstate_t* __ps, __locale_t __loc) {
+  __locale_guard __current(__loc);
+  return std::mbrtowc(__pwc, __s, __n, __ps);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI int __mbtowc(wchar_t* __pwc, const char* __pmb, size_t __max, __locale_t __loc) {
+  __locale_guard __current(__loc);
+  return std::mbtowc(__pwc, __pmb, __max);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI size_t __mbrlen(const char* __s, size_t __n, mbstate_t* __ps, __locale_t __loc) {
+  __locale_guard __current(__loc);
+  return std::mbrlen(__s, __n, __ps);
+}
+
+inline _LIBCPP_HIDE_FROM_ABI size_t
+__mbsrtowcs(wchar_t* __dest, const char** __src, size_t __len, mbstate_t* __ps, __locale_t __loc) {
+  __locale_guard __current(__loc);
+  return std::mbsrtowcs(__dest, __src, __len, __ps);
+}
+#  endif // _LIBCPP_HAS_WIDE_CHARACTERS
+#endif   // _LIBCPP_BUILDING_LIBRARY
+
+#ifndef _LIBCPP_COMPILER_GCC // GCC complains that this can't be always_inline due to C-style varargs
+_LIBCPP_HIDE_FROM_ABI
+#endif
+inline _LIBCPP_ATTRIBUTE_FORMAT(__printf__, 4, 5) int __snprintf(
+    char* __s, size_t __n, __locale_t __loc, const char* __format, ...) {
+  va_list __va;
+  va_start(__va, __format);
+  __locale_guard __current(__loc);
+  int __res = std::vsnprintf(__s, __n, __format, __va);
+  va_end(__va);
+  return __res;
+}
+
+#ifndef _LIBCPP_COMPILER_GCC // GCC complains that this can't be always_inline due to C-style varargs
+_LIBCPP_HIDE_FROM_ABI
+#endif
+inline _LIBCPP_ATTRIBUTE_FORMAT(__printf__, 3, 4) int __asprintf(
+    char** __s, __locale_t __loc, const char* __format, ...) {
+  va_list __va;
+  va_start(__va, __format);
+  __locale_guard __current(__loc);
+  int __res = ::vasprintf(__s, __format, __va); // non-standard
+  va_end(__va);
+  return __res;
+}
+
+#ifndef _LIBCPP_COMPILER_GCC // GCC complains that this can't be always_inline due to C-style varargs
+_LIBCPP_HIDE_FROM_ABI
+#endif
+inline _LIBCPP_ATTRIBUTE_FORMAT(__scanf__, 3, 4) int __sscanf(
+    const char* __s, __locale_t __loc, const char* __format, ...) {
+  va_list __va;
+  va_start(__va, __format);
+  __locale_guard __current(__loc);
+  int __res = std::vsscanf(__s, __format, __va);
+  va_end(__va);
+  return __res;
+}
+
+} // namespace __locale
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___LOCALE_DIR_SUPPORT_LINUX_H

libcxx/include/__locale_dir/support/windows.h

@@ -29,7 +29,7 @@
 _LIBCPP_BEGIN_NAMESPACE_STD
 namespace __locale {
 
-using __lconv_t = std::lconv;
+using __lconv_t _LIBCPP_NODEBUG = std::lconv;
 
 class __lconv_storage {
 public:

libcxx/include/module.modulemap

@@ -1510,6 +1510,7 @@ module std [system] {
       textual header "__locale_dir/support/bsd_like.h"
       textual header "__locale_dir/support/freebsd.h"
       textual header "__locale_dir/support/fuchsia.h"
+      textual header "__locale_dir/support/linux.h"
       textual header "__locale_dir/support/no_locale/characters.h"
       textual header "__locale_dir/support/no_locale/strtonum.h"
       textual header "__locale_dir/support/windows.h"