[PATCH] libstdc++: Implement std::chrono::current_zone() for Windows
Tomasz Kaminski
tkaminsk@redhat.com
Mon Jul 14 08:20:39 GMT 2025
On Tue, Jul 8, 2025 at 10:48 PM Björn Schäpers <gcc@hazardy.de> wrote:
> From: Björn Schäpers <bjoern@hazardy.de>
>
> I have based this on my previous (not yet landed) patch, but it only
> reuses the #ifdef to include <array>. Since std::array isn't used
> anywhere else I thought that was the right place to put it.
>
> I hope the formatting is okay.
>
> I've used wide strings for the Windows zone name and territory, since
> the Windows API returns wide strings and thus they can be compared
> directly. For the territory there exists a narrow string API, but
> internally it calls the wide string version and narrows it down. If
> desired I can switch to narrow strings, the conversion can be done by
> static_cast per character since only ASCII chars are used.
>
> -- >8 --
> On Windows there is no API to get the current time zone as IANA name,
> instead Windows has its own zones. But there exists a mapping provided
> by the Unicode Consortium. This patch adds a script to convert the XML
> file with the mapping to a lookup table and adds a Windows code path to
> use that mapping.
>
> libstdc++-v3/Changelog:
>
> Implement std::chrono::current_zone() for Windows
>
> * include/bits/windows_zones-map.h: New file, contains the look
> up table.
> * scripts/gen_windows_zones_map.py: New file, generates
> windows_zones-map.h.
> * src/c++20/tzdb.cc (tzdb::current_zone): Add Windows code path.
>
> Signed-off-by: Björn Schäpers <bjoern@hazardy.de>
> ---
> libstdc++-v3/include/bits/windows_zones-map.h | 407 ++++++++++++++++++
> libstdc++-v3/scripts/gen_windows_zones_map.py | 128 ++++++
> libstdc++-v3/src/c++20/tzdb.cc | 102 ++++-
> 3 files changed, 635 insertions(+), 2 deletions(-)
> create mode 100644 libstdc++-v3/include/bits/windows_zones-map.h
> create mode 100644 libstdc++-v3/scripts/gen_windows_zones_map.py
>
> diff --git a/libstdc++-v3/include/bits/windows_zones-map.h
> b/libstdc++-v3/include/bits/windows_zones-map.h
> new file mode 100644
> index 00000000000..7be736b063d
> --- /dev/null
> +++ b/libstdc++-v3/include/bits/windows_zones-map.h
> @@ -0,0 +1,407 @@
> +// Generated by scripts/gen_windows_zones_map.py, do not edit.
> +
> +// Copyright The GNU Toolchain Authors.
> +//
> +// 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/windows_zones-map.h
> + * This is an internal header file, included by other library headers.
> + * Do not attempt to use it directly. @headername{chrono}
> + */
> +
> +#ifndef _GLIBCXX_GET_WINDOWS_ZONES_MAP
> +# error "This is not a public header, do not include it directly"
> +#endif
> +
> +struct windows_zone_map_entry
> +{
> + wstring_view windows_name;
> + wstring_view territory;
> + string_view iana_name;
> +};
> +
> +static constexpr array<windows_zone_map_entry, 361> windows_zone_map{
> + {
> + {L"AUS Central Standard Time", L"001", "Australia/Darwin"},
> + {L"AUS Eastern Standard Time", L"001", "Australia/Sydney"},
> + {L"Afghanistan Standard Time", L"001", "Asia/Kabul"},
> + {L"Alaskan Standard Time", L"001", "America/Anchorage"},
> + {L"Aleutian Standard Time", L"001", "America/Adak"},
> + {L"Altai Standard Time", L"001", "Asia/Barnaul"},
> + {L"Arab Standard Time", L"001", "Asia/Riyadh"},
> + {L"Arab Standard Time", L"BH", "Asia/Bahrain"},
> + {L"Arab Standard Time", L"KW", "Asia/Kuwait"},
> + {L"Arab Standard Time", L"QA", "Asia/Qatar"},
> + {L"Arab Standard Time", L"YE", "Asia/Aden"},
> + {L"Arabian Standard Time", L"001", "Asia/Dubai"},
> + {L"Arabian Standard Time", L"OM", "Asia/Muscat"},
> + {L"Arabian Standard Time", L"ZZ", "Etc/GMT-4"},
> + {L"Arabic Standard Time", L"001", "Asia/Baghdad"},
> + {L"Argentina Standard Time", L"001", "America/Buenos_Aires"},
> + {L"Astrakhan Standard Time", L"001", "Europe/Astrakhan"},
> + {L"Atlantic Standard Time", L"001", "America/Halifax"},
> + {L"Atlantic Standard Time", L"BM", "Atlantic/Bermuda"},
> + {L"Atlantic Standard Time", L"GL", "America/Thule"},
> + {L"Aus Central W. Standard Time", L"001", "Australia/Eucla"},
> + {L"Azerbaijan Standard Time", L"001", "Asia/Baku"},
> + {L"Azores Standard Time", L"001", "Atlantic/Azores"},
> + {L"Azores Standard Time", L"GL", "America/Scoresbysund"},
> + {L"Bahia Standard Time", L"001", "America/Bahia"},
> + {L"Bangladesh Standard Time", L"001", "Asia/Dhaka"},
> + {L"Bangladesh Standard Time", L"BT", "Asia/Thimphu"},
> + {L"Belarus Standard Time", L"001", "Europe/Minsk"},
> + {L"Bougainville Standard Time", L"001", "Pacific/Bougainville"},
> + {L"Canada Central Standard Time", L"001", "America/Regina"},
> + {L"Cape Verde Standard Time", L"001", "Atlantic/Cape_Verde"},
> + {L"Cape Verde Standard Time", L"ZZ", "Etc/GMT+1"},
> + {L"Caucasus Standard Time", L"001", "Asia/Yerevan"},
> + {L"Cen. Australia Standard Time", L"001", "Australia/Adelaide"},
> + {L"Central America Standard Time", L"001", "America/Guatemala"},
> + {L"Central America Standard Time", L"BZ", "America/Belize"},
> + {L"Central America Standard Time", L"CR", "America/Costa_Rica"},
> + {L"Central America Standard Time", L"EC", "Pacific/Galapagos"},
> + {L"Central America Standard Time", L"HN", "America/Tegucigalpa"},
> + {L"Central America Standard Time", L"NI", "America/Managua"},
> + {L"Central America Standard Time", L"SV", "America/El_Salvador"},
> + {L"Central America Standard Time", L"ZZ", "Etc/GMT+6"},
> + {L"Central Asia Standard Time", L"001", "Asia/Bishkek"},
> + {L"Central Asia Standard Time", L"AQ", "Antarctica/Vostok"},
> + {L"Central Asia Standard Time", L"CN", "Asia/Urumqi"},
> + {L"Central Asia Standard Time", L"IO", "Indian/Chagos"},
> + {L"Central Asia Standard Time", L"ZZ", "Etc/GMT-6"},
> + {L"Central Brazilian Standard Time", L"001", "America/Cuiaba"},
> + {L"Central Europe Standard Time", L"001", "Europe/Budapest"},
> + {L"Central Europe Standard Time", L"AL", "Europe/Tirane"},
> + {L"Central Europe Standard Time", L"CZ", "Europe/Prague"},
> + {L"Central Europe Standard Time", L"ME", "Europe/Podgorica"},
> + {L"Central Europe Standard Time", L"RS", "Europe/Belgrade"},
> + {L"Central Europe Standard Time", L"SI", "Europe/Ljubljana"},
> + {L"Central Europe Standard Time", L"SK", "Europe/Bratislava"},
> + {L"Central European Standard Time", L"001", "Europe/Warsaw"},
> + {L"Central European Standard Time", L"BA", "Europe/Sarajevo"},
> + {L"Central European Standard Time", L"HR", "Europe/Zagreb"},
> + {L"Central European Standard Time", L"MK", "Europe/Skopje"},
> + {L"Central Pacific Standard Time", L"001", "Pacific/Guadalcanal"},
> + {L"Central Pacific Standard Time", L"AQ", "Antarctica/Casey"},
> + {L"Central Pacific Standard Time", L"FM", "Pacific/Ponape"},
> + {L"Central Pacific Standard Time", L"NC", "Pacific/Noumea"},
> + {L"Central Pacific Standard Time", L"VU", "Pacific/Efate"},
> + {L"Central Pacific Standard Time", L"ZZ", "Etc/GMT-11"},
> + {L"Central Standard Time", L"001", "America/Chicago"},
> + {L"Central Standard Time", L"CA", "America/Winnipeg"},
> + {L"Central Standard Time", L"MX", "America/Matamoros"},
> + {L"Central Standard Time (Mexico)", L"001", "America/Mexico_City"},
> + {L"Chatham Islands Standard Time", L"001", "Pacific/Chatham"},
> + {L"China Standard Time", L"001", "Asia/Shanghai"},
> + {L"China Standard Time", L"HK", "Asia/Hong_Kong"},
> + {L"China Standard Time", L"MO", "Asia/Macau"},
> + {L"Cuba Standard Time", L"001", "America/Havana"},
> + {L"Dateline Standard Time", L"001", "Etc/GMT+12"},
> + {L"E. Africa Standard Time", L"001", "Africa/Nairobi"},
> + {L"E. Africa Standard Time", L"AQ", "Antarctica/Syowa"},
> + {L"E. Africa Standard Time", L"DJ", "Africa/Djibouti"},
> + {L"E. Africa Standard Time", L"ER", "Africa/Asmera"},
> + {L"E. Africa Standard Time", L"ET", "Africa/Addis_Ababa"},
> + {L"E. Africa Standard Time", L"KM", "Indian/Comoro"},
> + {L"E. Africa Standard Time", L"MG", "Indian/Antananarivo"},
> + {L"E. Africa Standard Time", L"SO", "Africa/Mogadishu"},
> + {L"E. Africa Standard Time", L"TZ", "Africa/Dar_es_Salaam"},
> + {L"E. Africa Standard Time", L"UG", "Africa/Kampala"},
> + {L"E. Africa Standard Time", L"YT", "Indian/Mayotte"},
> + {L"E. Africa Standard Time", L"ZZ", "Etc/GMT-3"},
> + {L"E. Australia Standard Time", L"001", "Australia/Brisbane"},
> + {L"E. Europe Standard Time", L"001", "Europe/Chisinau"},
> + {L"E. South America Standard Time", L"001", "America/Sao_Paulo"},
> + {L"Easter Island Standard Time", L"001", "Pacific/Easter"},
> + {L"Eastern Standard Time", L"001", "America/New_York"},
> + {L"Eastern Standard Time", L"BS", "America/Nassau"},
> + {L"Eastern Standard Time", L"CA", "America/Toronto"},
> + {L"Eastern Standard Time (Mexico)", L"001", "America/Cancun"},
> + {L"Egypt Standard Time", L"001", "Africa/Cairo"},
> + {L"Ekaterinburg Standard Time", L"001", "Asia/Yekaterinburg"},
> + {L"FLE Standard Time", L"001", "Europe/Kiev"},
> + {L"FLE Standard Time", L"AX", "Europe/Mariehamn"},
> + {L"FLE Standard Time", L"BG", "Europe/Sofia"},
> + {L"FLE Standard Time", L"EE", "Europe/Tallinn"},
> + {L"FLE Standard Time", L"FI", "Europe/Helsinki"},
> + {L"FLE Standard Time", L"LT", "Europe/Vilnius"},
> + {L"FLE Standard Time", L"LV", "Europe/Riga"},
> + {L"Fiji Standard Time", L"001", "Pacific/Fiji"},
> + {L"GMT Standard Time", L"001", "Europe/London"},
> + {L"GMT Standard Time", L"ES", "Atlantic/Canary"},
> + {L"GMT Standard Time", L"FO", "Atlantic/Faeroe"},
> + {L"GMT Standard Time", L"GG", "Europe/Guernsey"},
> + {L"GMT Standard Time", L"IE", "Europe/Dublin"},
> + {L"GMT Standard Time", L"IM", "Europe/Isle_of_Man"},
> + {L"GMT Standard Time", L"JE", "Europe/Jersey"},
> + {L"GMT Standard Time", L"PT", "Europe/Lisbon"},
> + {L"GTB Standard Time", L"001", "Europe/Bucharest"},
> + {L"GTB Standard Time", L"CY", "Asia/Nicosia"},
> + {L"GTB Standard Time", L"GR", "Europe/Athens"},
> + {L"Georgian Standard Time", L"001", "Asia/Tbilisi"},
> + {L"Greenland Standard Time", L"001", "America/Godthab"},
> + {L"Greenwich Standard Time", L"001", "Atlantic/Reykjavik"},
> + {L"Greenwich Standard Time", L"BF", "Africa/Ouagadougou"},
> + {L"Greenwich Standard Time", L"CI", "Africa/Abidjan"},
> + {L"Greenwich Standard Time", L"GH", "Africa/Accra"},
> + {L"Greenwich Standard Time", L"GL", "America/Danmarkshavn"},
> + {L"Greenwich Standard Time", L"GM", "Africa/Banjul"},
> + {L"Greenwich Standard Time", L"GN", "Africa/Conakry"},
> + {L"Greenwich Standard Time", L"GW", "Africa/Bissau"},
> + {L"Greenwich Standard Time", L"LR", "Africa/Monrovia"},
> + {L"Greenwich Standard Time", L"ML", "Africa/Bamako"},
> + {L"Greenwich Standard Time", L"MR", "Africa/Nouakchott"},
> + {L"Greenwich Standard Time", L"SH", "Atlantic/St_Helena"},
> + {L"Greenwich Standard Time", L"SL", "Africa/Freetown"},
> + {L"Greenwich Standard Time", L"SN", "Africa/Dakar"},
> + {L"Greenwich Standard Time", L"TG", "Africa/Lome"},
> + {L"Haiti Standard Time", L"001", "America/Port-au-Prince"},
> + {L"Hawaiian Standard Time", L"001", "Pacific/Honolulu"},
> + {L"Hawaiian Standard Time", L"CK", "Pacific/Rarotonga"},
> + {L"Hawaiian Standard Time", L"PF", "Pacific/Tahiti"},
> + {L"Hawaiian Standard Time", L"ZZ", "Etc/GMT+10"},
> + {L"India Standard Time", L"001", "Asia/Calcutta"},
> + {L"Iran Standard Time", L"001", "Asia/Tehran"},
> + {L"Israel Standard Time", L"001", "Asia/Jerusalem"},
> + {L"Jordan Standard Time", L"001", "Asia/Amman"},
> + {L"Kaliningrad Standard Time", L"001", "Europe/Kaliningrad"},
> + {L"Korea Standard Time", L"001", "Asia/Seoul"},
> + {L"Libya Standard Time", L"001", "Africa/Tripoli"},
> + {L"Line Islands Standard Time", L"001", "Pacific/Kiritimati"},
> + {L"Line Islands Standard Time", L"ZZ", "Etc/GMT-14"},
> + {L"Lord Howe Standard Time", L"001", "Australia/Lord_Howe"},
> + {L"Magadan Standard Time", L"001", "Asia/Magadan"},
> + {L"Magallanes Standard Time", L"001", "America/Punta_Arenas"},
> + {L"Marquesas Standard Time", L"001", "Pacific/Marquesas"},
> + {L"Mauritius Standard Time", L"001", "Indian/Mauritius"},
> + {L"Mauritius Standard Time", L"RE", "Indian/Reunion"},
> + {L"Mauritius Standard Time", L"SC", "Indian/Mahe"},
> + {L"Middle East Standard Time", L"001", "Asia/Beirut"},
> + {L"Montevideo Standard Time", L"001", "America/Montevideo"},
> + {L"Morocco Standard Time", L"001", "Africa/Casablanca"},
> + {L"Morocco Standard Time", L"EH", "Africa/El_Aaiun"},
> + {L"Mountain Standard Time", L"001", "America/Denver"},
> + {L"Mountain Standard Time", L"CA", "America/Edmonton"},
> + {L"Mountain Standard Time", L"MX", "America/Ciudad_Juarez"},
> + {L"Mountain Standard Time (Mexico)", L"001", "America/Mazatlan"},
> + {L"Myanmar Standard Time", L"001", "Asia/Rangoon"},
> + {L"Myanmar Standard Time", L"CC", "Indian/Cocos"},
> + {L"N. Central Asia Standard Time", L"001", "Asia/Novosibirsk"},
> + {L"Namibia Standard Time", L"001", "Africa/Windhoek"},
> + {L"Nepal Standard Time", L"001", "Asia/Katmandu"},
> + {L"New Zealand Standard Time", L"001", "Pacific/Auckland"},
> + {L"New Zealand Standard Time", L"AQ", "Antarctica/McMurdo"},
> + {L"Newfoundland Standard Time", L"001", "America/St_Johns"},
> + {L"Norfolk Standard Time", L"001", "Pacific/Norfolk"},
> + {L"North Asia East Standard Time", L"001", "Asia/Irkutsk"},
> + {L"North Asia Standard Time", L"001", "Asia/Krasnoyarsk"},
> + {L"North Korea Standard Time", L"001", "Asia/Pyongyang"},
> + {L"Omsk Standard Time", L"001", "Asia/Omsk"},
> + {L"Pacific SA Standard Time", L"001", "America/Santiago"},
> + {L"Pacific Standard Time", L"001", "America/Los_Angeles"},
> + {L"Pacific Standard Time", L"CA", "America/Vancouver"},
> + {L"Pacific Standard Time (Mexico)", L"001", "America/Tijuana"},
> + {L"Pakistan Standard Time", L"001", "Asia/Karachi"},
> + {L"Paraguay Standard Time", L"001", "America/Asuncion"},
> + {L"Qyzylorda Standard Time", L"001", "Asia/Qyzylorda"},
> + {L"Romance Standard Time", L"001", "Europe/Paris"},
> + {L"Romance Standard Time", L"BE", "Europe/Brussels"},
> + {L"Romance Standard Time", L"DK", "Europe/Copenhagen"},
> + {L"Romance Standard Time", L"ES", "Europe/Madrid"},
> + {L"Russia Time Zone 10", L"001", "Asia/Srednekolymsk"},
> + {L"Russia Time Zone 11", L"001", "Asia/Kamchatka"},
> + {L"Russia Time Zone 3", L"001", "Europe/Samara"},
> + {L"Russian Standard Time", L"001", "Europe/Moscow"},
> + {L"Russian Standard Time", L"UA", "Europe/Simferopol"},
> + {L"SA Eastern Standard Time", L"001", "America/Cayenne"},
> + {L"SA Eastern Standard Time", L"AQ", "Antarctica/Rothera"},
> + {L"SA Eastern Standard Time", L"BR", "America/Fortaleza"},
> + {L"SA Eastern Standard Time", L"FK", "Atlantic/Stanley"},
> + {L"SA Eastern Standard Time", L"SR", "America/Paramaribo"},
> + {L"SA Eastern Standard Time", L"ZZ", "Etc/GMT+3"},
> + {L"SA Pacific Standard Time", L"001", "America/Bogota"},
> + {L"SA Pacific Standard Time", L"BR", "America/Rio_Branco"},
> + {L"SA Pacific Standard Time", L"CA", "America/Coral_Harbour"},
> + {L"SA Pacific Standard Time", L"EC", "America/Guayaquil"},
> + {L"SA Pacific Standard Time", L"JM", "America/Jamaica"},
> + {L"SA Pacific Standard Time", L"KY", "America/Cayman"},
> + {L"SA Pacific Standard Time", L"PA", "America/Panama"},
> + {L"SA Pacific Standard Time", L"PE", "America/Lima"},
> + {L"SA Pacific Standard Time", L"ZZ", "Etc/GMT+5"},
> + {L"SA Western Standard Time", L"001", "America/La_Paz"},
> + {L"SA Western Standard Time", L"AG", "America/Antigua"},
> + {L"SA Western Standard Time", L"AI", "America/Anguilla"},
> + {L"SA Western Standard Time", L"AW", "America/Aruba"},
> + {L"SA Western Standard Time", L"BB", "America/Barbados"},
> + {L"SA Western Standard Time", L"BL", "America/St_Barthelemy"},
> + {L"SA Western Standard Time", L"BQ", "America/Kralendijk"},
> + {L"SA Western Standard Time", L"BR", "America/Manaus"},
> + {L"SA Western Standard Time", L"CA", "America/Blanc-Sablon"},
> + {L"SA Western Standard Time", L"CW", "America/Curacao"},
> + {L"SA Western Standard Time", L"DM", "America/Dominica"},
> + {L"SA Western Standard Time", L"DO", "America/Santo_Domingo"},
> + {L"SA Western Standard Time", L"GD", "America/Grenada"},
> + {L"SA Western Standard Time", L"GP", "America/Guadeloupe"},
> + {L"SA Western Standard Time", L"GY", "America/Guyana"},
> + {L"SA Western Standard Time", L"KN", "America/St_Kitts"},
> + {L"SA Western Standard Time", L"LC", "America/St_Lucia"},
> + {L"SA Western Standard Time", L"MF", "America/Marigot"},
> + {L"SA Western Standard Time", L"MQ", "America/Martinique"},
> + {L"SA Western Standard Time", L"MS", "America/Montserrat"},
> + {L"SA Western Standard Time", L"PR", "America/Puerto_Rico"},
> + {L"SA Western Standard Time", L"SX", "America/Lower_Princes"},
> + {L"SA Western Standard Time", L"TT", "America/Port_of_Spain"},
> + {L"SA Western Standard Time", L"VC", "America/St_Vincent"},
> + {L"SA Western Standard Time", L"VG", "America/Tortola"},
> + {L"SA Western Standard Time", L"VI", "America/St_Thomas"},
> + {L"SA Western Standard Time", L"ZZ", "Etc/GMT+4"},
> + {L"SE Asia Standard Time", L"001", "Asia/Bangkok"},
> + {L"SE Asia Standard Time", L"AQ", "Antarctica/Davis"},
> + {L"SE Asia Standard Time", L"CX", "Indian/Christmas"},
> + {L"SE Asia Standard Time", L"ID", "Asia/Jakarta"},
> + {L"SE Asia Standard Time", L"KH", "Asia/Phnom_Penh"},
> + {L"SE Asia Standard Time", L"LA", "Asia/Vientiane"},
> + {L"SE Asia Standard Time", L"VN", "Asia/Saigon"},
> + {L"SE Asia Standard Time", L"ZZ", "Etc/GMT-7"},
> + {L"Saint Pierre Standard Time", L"001", "America/Miquelon"},
> + {L"Sakhalin Standard Time", L"001", "Asia/Sakhalin"},
> + {L"Samoa Standard Time", L"001", "Pacific/Apia"},
> + {L"Sao Tome Standard Time", L"001", "Africa/Sao_Tome"},
> + {L"Saratov Standard Time", L"001", "Europe/Saratov"},
> + {L"Singapore Standard Time", L"001", "Asia/Singapore"},
> + {L"Singapore Standard Time", L"BN", "Asia/Brunei"},
> + {L"Singapore Standard Time", L"ID", "Asia/Makassar"},
> + {L"Singapore Standard Time", L"MY", "Asia/Kuala_Lumpur"},
> + {L"Singapore Standard Time", L"PH", "Asia/Manila"},
> + {L"Singapore Standard Time", L"ZZ", "Etc/GMT-8"},
> + {L"South Africa Standard Time", L"001", "Africa/Johannesburg"},
> + {L"South Africa Standard Time", L"BI", "Africa/Bujumbura"},
> + {L"South Africa Standard Time", L"BW", "Africa/Gaborone"},
> + {L"South Africa Standard Time", L"CD", "Africa/Lubumbashi"},
> + {L"South Africa Standard Time", L"LS", "Africa/Maseru"},
> + {L"South Africa Standard Time", L"MW", "Africa/Blantyre"},
> + {L"South Africa Standard Time", L"MZ", "Africa/Maputo"},
> + {L"South Africa Standard Time", L"RW", "Africa/Kigali"},
> + {L"South Africa Standard Time", L"SZ", "Africa/Mbabane"},
> + {L"South Africa Standard Time", L"ZM", "Africa/Lusaka"},
> + {L"South Africa Standard Time", L"ZW", "Africa/Harare"},
> + {L"South Africa Standard Time", L"ZZ", "Etc/GMT-2"},
> + {L"South Sudan Standard Time", L"001", "Africa/Juba"},
> + {L"Sri Lanka Standard Time", L"001", "Asia/Colombo"},
> + {L"Sudan Standard Time", L"001", "Africa/Khartoum"},
> + {L"Syria Standard Time", L"001", "Asia/Damascus"},
> + {L"Taipei Standard Time", L"001", "Asia/Taipei"},
> + {L"Tasmania Standard Time", L"001", "Australia/Hobart"},
> + {L"Tocantins Standard Time", L"001", "America/Araguaina"},
> + {L"Tokyo Standard Time", L"001", "Asia/Tokyo"},
> + {L"Tokyo Standard Time", L"ID", "Asia/Jayapura"},
> + {L"Tokyo Standard Time", L"PW", "Pacific/Palau"},
> + {L"Tokyo Standard Time", L"TL", "Asia/Dili"},
> + {L"Tokyo Standard Time", L"ZZ", "Etc/GMT-9"},
> + {L"Tomsk Standard Time", L"001", "Asia/Tomsk"},
> + {L"Tonga Standard Time", L"001", "Pacific/Tongatapu"},
> + {L"Transbaikal Standard Time", L"001", "Asia/Chita"},
> + {L"Turkey Standard Time", L"001", "Europe/Istanbul"},
> + {L"Turks And Caicos Standard Time", L"001", "America/Grand_Turk"},
> + {L"US Eastern Standard Time", L"001", "America/Indianapolis"},
> + {L"US Mountain Standard Time", L"001", "America/Phoenix"},
> + {L"US Mountain Standard Time", L"CA", "America/Creston"},
> + {L"US Mountain Standard Time", L"MX", "America/Hermosillo"},
> + {L"US Mountain Standard Time", L"ZZ", "Etc/GMT+7"},
> + {L"UTC", L"001", "Etc/UTC"},
> + {L"UTC+12", L"001", "Etc/GMT-12"},
> + {L"UTC+12", L"KI", "Pacific/Tarawa"},
> + {L"UTC+12", L"MH", "Pacific/Majuro"},
> + {L"UTC+12", L"NR", "Pacific/Nauru"},
> + {L"UTC+12", L"TV", "Pacific/Funafuti"},
> + {L"UTC+12", L"UM", "Pacific/Wake"},
> + {L"UTC+12", L"WF", "Pacific/Wallis"},
> + {L"UTC+13", L"001", "Etc/GMT-13"},
> + {L"UTC+13", L"KI", "Pacific/Enderbury"},
> + {L"UTC+13", L"TK", "Pacific/Fakaofo"},
> + {L"UTC-02", L"001", "Etc/GMT+2"},
> + {L"UTC-02", L"BR", "America/Noronha"},
> + {L"UTC-02", L"GS", "Atlantic/South_Georgia"},
> + {L"UTC-08", L"001", "Etc/GMT+8"},
> + {L"UTC-08", L"PN", "Pacific/Pitcairn"},
> + {L"UTC-09", L"001", "Etc/GMT+9"},
> + {L"UTC-09", L"PF", "Pacific/Gambier"},
> + {L"UTC-11", L"001", "Etc/GMT+11"},
> + {L"UTC-11", L"AS", "Pacific/Pago_Pago"},
> + {L"UTC-11", L"NU", "Pacific/Niue"},
> + {L"UTC-11", L"UM", "Pacific/Midway"},
> + {L"Ulaanbaatar Standard Time", L"001", "Asia/Ulaanbaatar"},
> + {L"Venezuela Standard Time", L"001", "America/Caracas"},
> + {L"Vladivostok Standard Time", L"001", "Asia/Vladivostok"},
> + {L"Volgograd Standard Time", L"001", "Europe/Volgograd"},
> + {L"W. Australia Standard Time", L"001", "Australia/Perth"},
> + {L"W. Central Africa Standard Time", L"001", "Africa/Lagos"},
> + {L"W. Central Africa Standard Time", L"AO", "Africa/Luanda"},
> + {L"W. Central Africa Standard Time", L"BJ", "Africa/Porto-Novo"},
> + {L"W. Central Africa Standard Time", L"CD", "Africa/Kinshasa"},
> + {L"W. Central Africa Standard Time", L"CF", "Africa/Bangui"},
> + {L"W. Central Africa Standard Time", L"CG", "Africa/Brazzaville"},
> + {L"W. Central Africa Standard Time", L"CM", "Africa/Douala"},
> + {L"W. Central Africa Standard Time", L"DZ", "Africa/Algiers"},
> + {L"W. Central Africa Standard Time", L"GA", "Africa/Libreville"},
> + {L"W. Central Africa Standard Time", L"GQ", "Africa/Malabo"},
> + {L"W. Central Africa Standard Time", L"NE", "Africa/Niamey"},
> + {L"W. Central Africa Standard Time", L"TD", "Africa/Ndjamena"},
> + {L"W. Central Africa Standard Time", L"TN", "Africa/Tunis"},
> + {L"W. Central Africa Standard Time", L"ZZ", "Etc/GMT-1"},
> + {L"W. Europe Standard Time", L"001", "Europe/Berlin"},
> + {L"W. Europe Standard Time", L"AD", "Europe/Andorra"},
> + {L"W. Europe Standard Time", L"AT", "Europe/Vienna"},
> + {L"W. Europe Standard Time", L"CH", "Europe/Zurich"},
> + {L"W. Europe Standard Time", L"GI", "Europe/Gibraltar"},
> + {L"W. Europe Standard Time", L"IT", "Europe/Rome"},
> + {L"W. Europe Standard Time", L"LI", "Europe/Vaduz"},
> + {L"W. Europe Standard Time", L"LU", "Europe/Luxembourg"},
> + {L"W. Europe Standard Time", L"MC", "Europe/Monaco"},
> + {L"W. Europe Standard Time", L"MT", "Europe/Malta"},
> + {L"W. Europe Standard Time", L"NL", "Europe/Amsterdam"},
> + {L"W. Europe Standard Time", L"NO", "Europe/Oslo"},
> + {L"W. Europe Standard Time", L"SE", "Europe/Stockholm"},
> + {L"W. Europe Standard Time", L"SJ", "Arctic/Longyearbyen"},
> + {L"W. Europe Standard Time", L"SM", "Europe/San_Marino"},
> + {L"W. Europe Standard Time", L"VA", "Europe/Vatican"},
> + {L"W. Mongolia Standard Time", L"001", "Asia/Hovd"},
> + {L"West Asia Standard Time", L"001", "Asia/Tashkent"},
> + {L"West Asia Standard Time", L"AQ", "Antarctica/Mawson"},
> + {L"West Asia Standard Time", L"KZ", "Asia/Oral"},
> + {L"West Asia Standard Time", L"MV", "Indian/Maldives"},
> + {L"West Asia Standard Time", L"TF", "Indian/Kerguelen"},
> + {L"West Asia Standard Time", L"TJ", "Asia/Dushanbe"},
> + {L"West Asia Standard Time", L"TM", "Asia/Ashgabat"},
> + {L"West Asia Standard Time", L"ZZ", "Etc/GMT-5"},
> + {L"West Bank Standard Time", L"001", "Asia/Hebron"},
> + {L"West Pacific Standard Time", L"001", "Pacific/Port_Moresby"},
> + {L"West Pacific Standard Time", L"AQ", "Antarctica/DumontDUrville"},
> + {L"West Pacific Standard Time", L"FM", "Pacific/Truk"},
> + {L"West Pacific Standard Time", L"GU", "Pacific/Guam"},
> + {L"West Pacific Standard Time", L"MP", "Pacific/Saipan"},
> + {L"West Pacific Standard Time", L"ZZ", "Etc/GMT-10"},
> + {L"Yakutsk Standard Time", L"001", "Asia/Yakutsk"},
> + {L"Yukon Standard Time", L"001", "America/Whitehorse"},
> + }
> +};
> +
> +#undef _GLIBCXX_GET_WINDOWS_ZONES_MAP
> diff --git a/libstdc++-v3/scripts/gen_windows_zones_map.py
> b/libstdc++-v3/scripts/gen_windows_zones_map.py
> new file mode 100644
> index 00000000000..9edfe457a5f
> --- /dev/null
> +++ b/libstdc++-v3/scripts/gen_windows_zones_map.py
> @@ -0,0 +1,128 @@
> +#!/usr/bin/env python3
> +#
> +# Script to generate the map for libstdc++ std::chrono::current_zone
> under Windows.
> +#
> +# This file is part of GCC.
> +#
> +# GCC 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.
> +#
> +# GCC 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.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with GCC; see the file COPYING3. If not see
> +# <http://www.gnu.org/licenses/>.
> +
> +# To update the Libstdc++ static data in <bits/windows_zones-map.h>
> download
> +# the latest:
> +#
> https://raw.githubusercontent.com/unicode-org/cldr/master/common/supplemental/windowsZones.xml
> +# Then run this script and save the output to
> +# include/bits/windows_zones-map.h
> +
> +import os
> +import sys
> +import xml.etree.ElementTree as et
> +
> +if len(sys.argv) != 2:
> + print("Usage: %s <windows zones xml>" % sys.argv[0], file=sys.stderr)
> + sys.exit(1)
> +
> +self = os.path.basename(__file__)
> +print("// Generated by scripts/{}, do not edit.".format(self))
> +print("""
> +// Copyright The GNU Toolchain Authors.
> +//
> +// 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/windows_zones-map.h
> + * This is an internal header file, included by other library headers.
> + * Do not attempt to use it directly. @headername{chrono}
> + */
> +""")
> +
> +print("#ifndef _GLIBCXX_GET_WINDOWS_ZONES_MAP")
> +print('# error "This is not a public header, do not include it directly"')
> +print("#endif\n")
> +
> +class WindowsZoneMapEntry:
> + def __init__(self, windows, territory, iana):
> + self.windows = windows
> + self.territory = territory
> + self.iana = iana
> +
> + def __lt__(self, other):
> + if self.windows < other.windows:
> + return True
> + if self.windows > other.windows:
> + return False
> + return self.territory < other.territory
> +
> +windows_zone_map = []
> +
> +tree = et.parse(sys.argv[1])
> +xml_zone_map = tree.getroot().find("windowsZones").find("mapTimezones")
> +
> +for entry in xml_zone_map.iter("mapZone"):
> + iana = entry.attrib["type"]
> + space = iana.find(" ")
> + if space != -1:
> + iana = iana[0:space]
> + windows_zone_map.append(WindowsZoneMapEntry(entry.attrib["other"],
> entry.attrib["territory"], iana))
> +
> +# Sort so we can use binary search on the array.
> +windows_zone_map.sort();
> +
> +# Skip territories which have the same IANA zone as 001, so we can reduce
> the data.
> +last_windows_zone = ""
> +for entry in windows_zone_map[:]:
> + if entry.windows != last_windows_zone:
> + if entry.territory != "001":
> + raise ValueError("Territory \"001\" not the first one, this
> breaks assumptions in tzdb.cc!")
> + last_windows_zone = entry.windows
> + fallback_iana = entry.iana
> + else:
> + if entry.iana == fallback_iana:
> + windows_zone_map.remove(entry)
> +
> +print("""struct windows_zone_map_entry
> +{{
> + wstring_view windows_name;
> + wstring_view territory;
> + string_view iana_name;
> +}};
> +
> +static constexpr array<windows_zone_map_entry, {}> windows_zone_map{{
> + {{""".format(len(windows_zone_map)))
> +
> +for entry in windows_zone_map:
> + print(' {{L"{}", L"{}", "{}"}},'.format(entry.windows,
> entry.territory, entry.iana))
> +
> +print(""" }
> +};""")
> +
> +# <chrono> gives an error if this macro is left defined.
> +# Do this last, so that the generated output is not usable unless we
> reach here.
> +print("\n#undef _GLIBCXX_GET_WINDOWS_ZONES_MAP")
> diff --git a/libstdc++-v3/src/c++20/tzdb.cc
> b/libstdc++-v3/src/c++20/tzdb.cc
> index 9923d14b7a7..bfbba077b92 100644
> --- a/libstdc++-v3/src/c++20/tzdb.cc
> +++ b/libstdc++-v3/src/c++20/tzdb.cc
> @@ -48,6 +48,8 @@
> # define WIN32_LEAN_AND_MEAN
> # include <windows.h>
> # include <psapi.h>
> +
> +# include <array>
> #endif
>
> #if defined __GTHREADS && ATOMIC_POINTER_LOCK_FREE == 2
> @@ -1768,6 +1770,98 @@ namespace std::chrono
>
> return nullptr; // not found
> }
> +
> +#ifdef _GLIBCXX_HAVE_WINDOWS_H
> + string_view
> + detect_windows_zone() noexcept
> + {
> + DYNAMIC_TIME_ZONE_INFORMATION information{};
> + if (GetDynamicTimeZoneInformation(&information) ==
> TIME_ZONE_ID_INVALID)
> + return {};
> +
> + constexpr SYSTEMTIME all_zero_time{};
> + const wstring_view zone_name{ information.TimeZoneKeyName };
> + auto equal = [](const SYSTEMTIME &lhs, const SYSTEMTIME &rhs)
> noexcept
> + { return memcmp(&lhs, &rhs, sizeof(SYSTEMTIME)) == 0; };
> + // The logic is copied from icu, couldn't find the source.
> + // Detect if DST is disabled.
> + if (information.DynamicDaylightTimeDisabled
> + && equal(information.StandardDate, information.DaylightDate)
> + && ((!zone_name.empty()
> + && equal(information.StandardDate, all_zero_time))
> + || (zone_name.empty()
> + && !equal(information.StandardDate, all_zero_time))))
> + {
> + if (information.Bias == 0)
> + return "Etc/UTC";
> +
> + if (information.Bias % 60 != 0)
> + // If the offset is not in full hours, we can't do anything
> really.
> + return {};
> +
> + const auto raw_index = information.Bias / 60;
> +
> + // The bias added to the local time equals UTC. And GMT+X
> corrosponds
> + // to UTC-X, the sign is negated. Thus we can use the hourly
> bias as
> + // an index into an array.
> + if (raw_index < 0 && raw_index >= -14)
> + {
> + static array<string_view, 14> table{
> + "Etc/GMT-1", "Etc/GMT-2", "Etc/GMT-3", "Etc/GMT-4",
> + "Etc/GMT-5", "Etc/GMT-6", "Etc/GMT-7", "Etc/GMT-8",
> + "Etc/GMT-9", "Etc/GMT-10", "Etc/GMT-11", "Etc/GMT-12",
> + "Etc/GMT-13", "Etc/GMT-14"
> + };
> + return table[-raw_index - 1];
> + }
> + else if (raw_index > 0 && raw_index <= 12)
> + {
> + static array<string_view, 14> table{
>
This table has size 14, but only 12 entries. I do not think there are zones
past +12,
but I believe size and entries should match.
> + "Etc/GMT+1", "Etc/GMT+2", "Etc/GMT+3", "Etc/GMT+4",
> + "Etc/GMT+5", "Etc/GMT+6", "Etc/GMT+7", "Etc/GMT+8",
> + "Etc/GMT+9", "Etc/GMT+10", "Etc/GMT+11", "Etc/GMT+12"
> + };
> + return table[raw_index - 1];
> + }
> + return {};
> + }
> +
> +#define _GLIBCXX_GET_WINDOWS_ZONES_MAP
> +#include <bits/windows_zones-map.h>
> +#ifdef _GLIBCXX_GET_WINDOWS_ZONES_MAP
> +# error "Invalid windows_zones map"
> +#endif
> +
> + const auto zone_range
> + = ranges::equal_range(windows_zone_map, zone_name, {},
> + &windows_zone_map_entry::windows_name);
> +
> + const auto size = ranges::size(zone_range);
> + if (size == 0)
> + // Unknown zone, we can't detect anything.
> + return {};
> +
> + if (size == 1)
> + // Some zones have only one territory, use the quick path.
> + return zone_range.front().iana_name;
> +
> + const auto geo_id = GetUserGeoID(GEOCLASS_NATION);
> + wstring territory;
> + territory.resize(2); // The terminating zero is always added on top.
> + if (GetGeoInfoW(geo_id, GEO_ISO2, territory.data(), 3, 0) == 0)
> + // Couldn't detect the territory, fallback to "001", which is the
> first
> + // entry.
> + return zone_range.front().iana_name;
> +
> + const auto iter = ranges::lower_bound(
> + zone_range, territory, {}, &windows_zone_map_entry::territory);
> + if (iter == zone_range.end() || iter->territory != territory)
> + // Territory not within the the map, use "001".
> + return zone_range.front().iana_name;
> +
> + return iter->iana_name;
> + }
> +#endif
> } // namespace
>
> // Implementation of std::chrono::tzdb::locate_zone(string_view).
> @@ -1790,7 +1884,7 @@ namespace std::chrono
> {
> // TODO cache this function's result?
>
> -#ifndef _AIX
> +#if !defined(_AIX) && !defined(_GLIBCXX_HAVE_WINDOWS_H)
> // Repeat the preprocessor condition used by filesystem::read_symlink,
> // to avoid a dependency on src/c++17/fs_ops.o if it won't work
> anyway.
> #if defined(_GLIBCXX_HAVE_READLINK) && defined(_GLIBCXX_HAVE_SYS_STAT_H)
> @@ -1847,7 +1941,11 @@ namespace std::chrono
> return tz;
> }
> }
> -#else
> +#elif defined(_GLIBCXX_HAVE_WINDOWS_H)
> + if (auto tz
> + = do_locate_zone(this->zones, this->links, detect_windows_zone()))
> + return tz;
> +#else // defined(_AIX)
> // AIX stores current zone in $TZ in /etc/environment but the value
> // is typically a POSIX time zone name, not IANA zone.
> // https://developer.ibm.com/articles/au-aix-posix/
> --
> 2.50.0
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://gcc.gnu.org/pipermail/libstdc++/attachments/20250714/1656abc9/attachment-0001.htm>
More information about the Libstdc++
mailing list