1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___LOCALE_LOCALE_BASE_API_LOCALE_GUARD_H 10 #define _LIBCPP___LOCALE_LOCALE_BASE_API_LOCALE_GUARD_H 11 12 #include <__config> 13 #include <__locale> // for locale_t 14 #include <clocale> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 # pragma GCC system_header 18 #endif 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 #if !defined(_LIBCPP_LOCALE__L_EXTENSIONS) 23 struct __libcpp_locale_guard { __libcpp_locale_guard__libcpp_locale_guard24 _LIBCPP_HIDE_FROM_ABI __libcpp_locale_guard(locale_t& __loc) : __old_loc_(uselocale(__loc)) {} 25 ~__libcpp_locale_guard__libcpp_locale_guard26 _LIBCPP_HIDE_FROM_ABI ~__libcpp_locale_guard() { 27 if (__old_loc_) 28 uselocale(__old_loc_); 29 } 30 31 locale_t __old_loc_; 32 33 __libcpp_locale_guard(__libcpp_locale_guard const&) = delete; 34 __libcpp_locale_guard& operator=(__libcpp_locale_guard const&) = delete; 35 }; 36 #elif defined(_LIBCPP_MSVCRT_LIKE) 37 struct __libcpp_locale_guard { 38 __libcpp_locale_guard(locale_t __l) : __status(_configthreadlocale(_ENABLE_PER_THREAD_LOCALE)) { 39 // Setting the locale can be expensive even when the locale given is 40 // already the current locale, so do an explicit check to see if the 41 // current locale is already the one we want. 42 const char* __lc = __setlocale(nullptr); 43 // If every category is the same, the locale string will simply be the 44 // locale name, otherwise it will be a semicolon-separated string listing 45 // each category. In the second case, we know at least one category won't 46 // be what we want, so we only have to check the first case. 47 if (std::strcmp(__l.__get_locale(), __lc) != 0) { 48 __locale_all = _strdup(__lc); 49 if (__locale_all == nullptr) 50 __throw_bad_alloc(); 51 __setlocale(__l.__get_locale()); 52 } 53 } 54 ~__libcpp_locale_guard() { 55 // The CRT documentation doesn't explicitly say, but setlocale() does the 56 // right thing when given a semicolon-separated list of locale settings 57 // for the different categories in the same format as returned by 58 // setlocale(LC_ALL, nullptr). 59 if (__locale_all != nullptr) { 60 __setlocale(__locale_all); 61 free(__locale_all); 62 } 63 _configthreadlocale(__status); 64 } 65 static const char* __setlocale(const char* __locale) { 66 const char* __new_locale = setlocale(LC_ALL, __locale); 67 if (__new_locale == nullptr) 68 __throw_bad_alloc(); 69 return __new_locale; 70 } 71 int __status; 72 char* __locale_all = nullptr; 73 }; 74 #endif 75 76 _LIBCPP_END_NAMESPACE_STD 77 78 #endif // _LIBCPP___LOCALE_LOCALE_BASE_API_LOCALE_GUARD_H 79