// Locale support -*- C++ -*- // Copyright (C) 1997-2020 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file bits/locale_classes.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{locale} */ // // ISO C++ 14882: 22.1 Locales // #ifndef _LOCALE_CLASSES_H #define _LOCALE_CLASSES_H 1 #pragma GCC system_header #include <bits/localefwd.h> #include <string> #include <ext/atomicity.h> namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION // 22.1.1 Class locale /** * @brief Container class for localization functionality. * @ingroup locales * * The locale class is first a class wrapper for C library locales. It is * also an extensible container for user-defined localization. A locale is * a collection of facets that implement various localization features such * as money, time, and number printing. * * Constructing C++ locales does not change the C library locale. * * This library supports efficient construction and copying of locales * through a reference counting implementation of the locale class. */ class locale { public: // Types: /// Definition of locale::category. typedef int category; // Forward decls and friends: class facet; class id; class _Impl; friend class facet; friend class _Impl; template<typename _Facet> friend bool has_facet(const locale&) throw(); template<typename _Facet> friend const _Facet& use_facet(const locale&); template<typename _Cache> friend struct __use_cache; //@{ /** * @brief Category values. * * The standard category values are none, ctype, numeric, collate, time, * monetary, and messages. They form a bitmask that supports union and * intersection. The category all is the union of these values. * * NB: Order must match _S_facet_categories definition in locale.cc */ static const category none = 0; static const category ctype = 1L << 0; static const category numeric = 1L << 1; static const category collate = 1L << 2; static const category time = 1L << 3; static const category monetary = 1L << 4; static const category messages = 1L << 5; static const category all = (ctype | numeric | collate | time | monetary | messages); //@} // Construct/copy/destroy: /** * @brief Default constructor. * * Constructs a copy of the global locale. If no locale has been * explicitly set, this is the C locale. */ locale() throw(); /** * @brief Copy constructor. * * Constructs a copy of @a other. * * @param __other The locale to copy. */ locale(const locale& __other) throw(); /** * @brief Named locale constructor. * * Constructs a copy of the named C library locale. * * @param __s Name of the locale to construct. * @throw std::runtime_error if __s is null or an undefined locale. */ explicit locale(const char* __s); /** * @brief Construct locale with facets from another locale. * * Constructs a copy of the locale @a base. The facets specified by @a * cat are replaced with those from the locale named by @a s. If base is * named, this locale instance will also be named. * * @param __base The locale to copy. * @param __s Name of the locale to use facets from. * @param __cat Set of categories defining the facets to use from __s. * @throw std::runtime_error if __s is null or an undefined locale. */ locale(const locale& __base, const char* __s, category __cat); #if __cplusplus >= 201103L /** * @brief Named locale constructor. * * Constructs a copy of the named C library locale. * * @param __s Name of the locale to construct. * @throw std::runtime_error if __s is an undefined locale. */ explicit locale(const std::string& __s) : locale(__s.c_str()) { } /** * @brief Construct locale with facets from another locale. * * Constructs a copy of the locale @a base. The facets specified by @a * cat are replaced with those from the locale named by @a s. If base is * named, this locale instance will also be named. * * @param __base The locale to copy. * @param __s Name of the locale to use facets from. * @param __cat Set of categories defining the facets to use from __s. * @throw std::runtime_error if __s is an undefined locale. */ locale(const locale& __base, const std::string& __s, category __cat) : locale(__base, __s.c_str(), __cat) { } #endif /** * @brief Construct locale with facets from another locale. * * Constructs a copy of the locale @a base. The facets specified by @a * cat are replaced with those from the locale @a add. If @a base and @a * add are named, this locale instance will also be named. * * @param __base The locale to copy. * @param __add The locale to use facets from. * @param __cat Set of categories defining the facets to use from add. */ locale(const locale& __base, const locale& __add, category __cat); /** * @brief Construct locale with another facet. * * Constructs a copy of the locale @a __other. The facet @a __f * is added to @a __other, replacing an existing facet of type * Facet if there is one. If @a __f is null, this locale is a * copy of @a __other. * * @param __other The locale to copy. * @param __f The facet to add in. */ template<typename _Facet> locale(const locale& __other, _Facet* __f); /// Locale destructor. ~locale() throw(); /** * @brief Assignment operator. * * Set this locale to be a copy of @a other. * * @param __other The locale to copy. * @return A reference to this locale. */ const locale& operator=(const locale& __other) throw(); /** * @brief Construct locale with another facet. * * Constructs and returns a new copy of this locale. Adds or replaces an * existing facet of type Facet from the locale @a other into the new * locale. * * @tparam _Facet The facet type to copy from other * @param __other The locale to copy from. * @return Newly constructed locale. * @throw std::runtime_error if __other has no facet of type _Facet. */ template<typename _Facet> locale combine(const locale& __other) const; // Locale operations: /** * @brief Return locale name. * @return Locale name or "*" if unnamed. */ _GLIBCXX_DEFAULT_ABI_TAG string name() const; /** * @brief Locale equality. * * @param __other The locale to compare against. * @return True if other and this refer to the same locale instance, are * copies, or have the same name. False otherwise. */ bool operator==(const locale& __other) const throw(); #if __cpp_impl_three_way_comparison < 201907L /** * @brief Locale inequality. * * @param __other The locale to compare against. * @return ! (*this == __other) */ bool operator!=(const locale& __other) const throw() { return !(this->operator==(__other)); } #endif /** * @brief Compare two strings according to collate. * * Template operator to compare two strings using the compare function of * the collate facet in this locale. One use is to provide the locale to * the sort function. For example, a vector v of strings could be sorted * according to locale loc by doing: * @code * std::sort(v.begin(), v.end(), loc); * @endcode * * @param __s1 First string to compare. * @param __s2 Second string to compare. * @return True if collate<_Char> facet compares __s1 < __s2, else false. */ template<typename _Char, typename _Traits, typename _Alloc> bool operator()(const basic_string<_Char, _Traits, _Alloc>& __s1, const basic_string<_Char, _Traits, _Alloc>& __s2) const; // Global locale objects: /** * @brief Set global locale * * This function sets the global locale to the argument and returns a * copy of the previous global locale. If the argument has a name, it * will also call std::setlocale(LC_ALL, loc.name()). * * @param __loc The new locale to make global. * @return Copy of the old global locale. */ static locale global(const locale& __loc); /** * @brief Return reference to the C locale. */ static const locale& classic(); private: // The (shared) implementation _Impl* _M_impl; // The "C" reference locale static _Impl* _S_classic; // Current global locale static _Impl* _S_global; // Names of underlying locale categories. // NB: locale::global() has to know how to modify all the // underlying categories, not just the ones required by the C++ // standard. static const char* const* const _S_categories; // Number of standard categories. For C++, these categories are // collate, ctype, monetary, numeric, time, and messages. These // directly correspond to ISO C99 macros LC_COLLATE, LC_CTYPE, // LC_MONETARY, LC_NUMERIC, and LC_TIME. In addition, POSIX (IEEE // 1003.1-2001) specifies LC_MESSAGES. // In addition to the standard categories, the underlying // operating system is allowed to define extra LC_* // macros. For GNU systems, the following are also valid: // LC_PAPER, LC_NAME, LC_ADDRESS, LC_TELEPHONE, LC_MEASUREMENT, // and LC_IDENTIFICATION. enum { _S_categories_size = 6 + _GLIBCXX_NUM_CATEGORIES }; #ifdef __GTHREADS static __gthread_once_t _S_once; #endif explicit locale(_Impl*) throw(); static void _S_initialize(); static void _S_initialize_once() throw(); static category _S_normalize_category(category); void _M_coalesce(const locale& __base, const locale& __add, category __cat); #if _GLIBCXX_USE_CXX11_ABI static const id* const _S_twinned_facets[]; #endif }; // 22.1.1.1.2 Class locale::facet /** * @brief Localization functionality base class. * @ingroup locales * * The facet class is the base class for a localization feature, such as * money, time, and number printing. It provides common support for facets * and reference management. * * Facets may not be copied or assigned. */ class locale::facet { private: friend class locale; friend class locale::_Impl; mutable _Atomic_word _M_refcount; // Contains data from the underlying "C" library for the classic locale. static __c_locale _S_c_locale; // String literal for the name of the classic locale. static const char _S_c_name[2]; #ifdef __GTHREADS static __gthread_once_t _S_once; #endif static void _S_initialize_once(); protected: /** * @brief Facet constructor. * * This is the constructor provided by the standard. If refs is 0, the * facet is destroyed when the last referencing locale is destroyed. * Otherwise the facet will never be destroyed. * * @param __refs The initial value for reference count. */ explicit facet(size_t __refs = 0) throw() : _M_refcount(__refs ? 1 : 0) { } /// Facet destructor. virtual ~facet(); static void _S_create_c_locale(__c_locale& __cloc, const char* __s, __c_locale __old = 0); static __c_locale _S_clone_c_locale(__c_locale& __cloc) throw(); static void _S_destroy_c_locale(__c_locale& __cloc); static __c_locale _S_lc_ctype_c_locale(__c_locale __cloc, const char* __s); // Returns data from the underlying "C" library data for the // classic locale. static __c_locale _S_get_c_locale(); _GLIBCXX_CONST static const char* _S_get_c_name() throw(); #if __cplusplus < 201103L private: facet(const facet&); // Not defined. facet& operator=(const facet&); // Not defined. #else facet(const facet&) = delete; facet& operator=(const facet&) = delete; #endif private: void _M_add_reference() const throw() { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); } void _M_remove_reference() const throw() { // Be race-detector-friendly. For more info see bits/c++config. _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount); if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1) { _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount); __try { delete this; } __catch(...) { } } } const facet* _M_sso_shim(const id*) const; const facet* _M_cow_shim(const id*) const; protected: class __shim; // For internal use only. }; // 22.1.1.1.3 Class locale::id /** * @brief Facet ID class. * @ingroup locales * * The ID class provides facets with an index used to identify them. * Every facet class must define a public static member locale::id, or be * derived from a facet that provides this member, otherwise the facet * cannot be used in a locale. The locale::id ensures that each class * type gets a unique identifier. */ class locale::id { private: friend class locale; friend class locale::_Impl; template<typename _Facet> friend const _Facet& use_facet(const locale&); template<typename _Facet> friend bool has_facet(const locale&) throw(); // NB: There is no accessor for _M_index because it may be used // before the constructor is run; the effect of calling a member // function (even an inline) would be undefined. mutable size_t _M_index; // Last id number assigned. static _Atomic_word _S_refcount; void operator=(const id&); // Not defined. id(const id&); // Not defined. public: // NB: This class is always a static data member, and thus can be // counted on to be zero-initialized. /// Constructor. id() { } size_t _M_id() const throw(); }; // Implementation object for locale. class locale::_Impl { public: // Friends. friend class locale; friend class locale::facet; template<typename _Facet> friend bool has_facet(const locale&) throw(); template<typename _Facet> friend const _Facet& use_facet(const locale&); template<typename _Cache> friend struct __use_cache; private: // Data Members. _Atomic_word _M_refcount; const facet** _M_facets; size_t _M_facets_size; const facet** _M_caches; char** _M_names; static const locale::id* const _S_id_ctype[]; static const locale::id* const _S_id_numeric[]; static const locale::id* const _S_id_collate[]; static const locale::id* const _S_id_time[]; static const locale::id* const _S_id_monetary[]; static const locale::id* const _S_id_messages[]; static const locale::id* const* const _S_facet_categories[]; void _M_add_reference() throw() { __gnu_cxx::__atomic_add_dispatch(&_M_refcount, 1); } void _M_remove_reference() throw() { // Be race-detector-friendly. For more info see bits/c++config. _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_refcount); if (__gnu_cxx::__exchange_and_add_dispatch(&_M_refcount, -1) == 1) { _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_refcount); __try { delete this; } __catch(...) { } } } _Impl(const _Impl&, size_t); _Impl(const char*, size_t); _Impl(size_t) throw(); ~_Impl() throw(); _Impl(const _Impl&); // Not defined. void operator=(const _Impl&); // Not defined. bool _M_check_same_name() { bool __ret = true; if (_M_names[1]) // We must actually compare all the _M_names: can be all equal! for (size_t __i = 0; __ret && __i < _S_categories_size - 1; ++__i) __ret = __builtin_strcmp(_M_names[__i], _M_names[__i + 1]) == 0; return __ret; } void _M_replace_categories(const _Impl*, category); void _M_replace_category(const _Impl*, const locale::id* const*); void _M_replace_facet(const _Impl*, const locale::id*); void _M_install_facet(const locale::id*, const facet*); template<typename _Facet> void _M_init_facet(_Facet* __facet) { _M_install_facet(&_Facet::id, __facet); } template<typename _Facet> void _M_init_facet_unchecked(_Facet* __facet) { __facet->_M_add_reference(); _M_facets[_Facet::id._M_id()] = __facet; } void _M_install_cache(const facet*, size_t); void _M_init_extra(facet**); void _M_init_extra(void*, void*, const char*, const char*); }; /** * @brief Facet for localized string comparison. * * This facet encapsulates the code to compare strings in a localized * manner. * * The collate template uses protected virtual functions to provide * the actual results. The public accessors forward the call to * the virtual functions. These virtual functions are hooks for * developers to implement the behavior they require from the * collate facet. */ template<typename _CharT> class _GLIBCXX_NAMESPACE_CXX11 collate : public locale::facet { public: // Types: //@{ /// Public typedefs typedef _CharT char_type; typedef basic_string<_CharT> string_type; //@} protected: // Underlying "C" library locale information saved from // initialization, needed by collate_byname as well. __c_locale _M_c_locale_collate; public: /// Numpunct facet id. static locale::id id; /** * @brief Constructor performs initialization. * * This is the constructor provided by the standard. * * @param __refs Passed to the base facet class. */ explicit collate(size_t __refs = 0) : facet(__refs), _M_c_locale_collate(_S_get_c_locale()) { } /** * @brief Internal constructor. Not for general use. * * This is a constructor for use by the library itself to set up new * locales. * * @param __cloc The C locale. * @param __refs Passed to the base facet class. */ explicit collate(__c_locale __cloc, size_t __refs = 0) : facet(__refs), _M_c_locale_collate(_S_clone_c_locale(__cloc)) { } /** * @brief Compare two strings. * * This function compares two strings and returns the result by calling * collate::do_compare(). * * @param __lo1 Start of string 1. * @param __hi1 End of string 1. * @param __lo2 Start of string 2. * @param __hi2 End of string 2. * @return 1 if string1 > string2, -1 if string1 < string2, else 0. */ int compare(const _CharT* __lo1, const _CharT* __hi1, const _CharT* __lo2, const _CharT* __hi2) const { return this->do_compare(__lo1, __hi1, __lo2, __hi2); } /** * @brief Transform string to comparable form. * * This function is a wrapper for strxfrm functionality. It takes the * input string and returns a modified string that can be directly * compared to other transformed strings. In the C locale, this * function just returns a copy of the input string. In some other * locales, it may replace two chars with one, change a char for * another, etc. It does so by returning collate::do_transform(). * * @param __lo Start of string. * @param __hi End of string. * @return Transformed string_type. */ string_type transform(const _CharT* __lo, const _CharT* __hi) const { return this->do_transform(__lo, __hi); } /** * @brief Return hash of a string. * * This function computes and returns a hash on the input string. It * does so by returning collate::do_hash(). * * @param __lo Start of string. * @param __hi End of string. * @return Hash value. */ long hash(const _CharT* __lo, const _CharT* __hi) const { return this->do_hash(__lo, __hi); } // Used to abstract out _CharT bits in virtual member functions, below. int _M_compare(const _CharT*, const _CharT*) const throw(); size_t _M_transform(_CharT*, const _CharT*, size_t) const throw(); protected: /// Destructor. virtual ~collate() { _S_destroy_c_locale(_M_c_locale_collate); } /** * @brief Compare two strings. * * This function is a hook for derived classes to change the value * returned. @see compare(). * * @param __lo1 Start of string 1. * @param __hi1 End of string 1. * @param __lo2 Start of string 2. * @param __hi2 End of string 2. * @return 1 if string1 > string2, -1 if string1 < string2, else 0. */ virtual int do_compare(const _CharT* __lo1, const _CharT* __hi1, const _CharT* __lo2, const _CharT* __hi2) const; /** * @brief Transform string to comparable form. * * This function is a hook for derived classes to change the value * returned. * * @param __lo Start. * @param __hi End. * @return transformed string. */ virtual string_type do_transform(const _CharT* __lo, const _CharT* __hi) const; /** * @brief Return hash of a string. * * This function computes and returns a hash on the input string. This * function is a hook for derived classes to change the value returned. * * @param __lo Start of string. * @param __hi End of string. * @return Hash value. */ virtual long do_hash(const _CharT* __lo, const _CharT* __hi) const; }; template<typename _CharT> locale::id collate<_CharT>::id; // Specializations. template<> int collate<char>::_M_compare(const char*, const char*) const throw(); template<> size_t collate<char>::_M_transform(char*, const char*, size_t) const throw(); #ifdef _GLIBCXX_USE_WCHAR_T template<> int collate<wchar_t>::_M_compare(const wchar_t*, const wchar_t*) const throw(); template<> size_t collate<wchar_t>::_M_transform(wchar_t*, const wchar_t*, size_t) const throw(); #endif /// class collate_byname [22.2.4.2]. template<typename _CharT> class _GLIBCXX_NAMESPACE_CXX11 collate_byname : public collate<_CharT> { public: //@{ /// Public typedefs typedef _CharT char_type; typedef basic_string<_CharT> string_type; //@} explicit collate_byname(const char* __s, size_t __refs = 0) : collate<_CharT>(__refs) { if (__builtin_strcmp(__s, "C") != 0 && __builtin_strcmp(__s, "POSIX") != 0) { this->_S_destroy_c_locale(this->_M_c_locale_collate); this->_S_create_c_locale(this->_M_c_locale_collate, __s); } } #if __cplusplus >= 201103L explicit collate_byname(const string& __s, size_t __refs = 0) : collate_byname(__s.c_str(), __refs) { } #endif protected: virtual ~collate_byname() { } }; _GLIBCXX_END_NAMESPACE_VERSION } // namespace # include <bits/locale_classes.tcc> #endif