[libcxx-commits] [libcxx] [libc++][TZDB] Implements zoned_traits. (PR #91059)
Mark de Wever via libcxx-commits
libcxx-commits at lists.llvm.org
Mon Jun 10 03:41:17 PDT 2024
https://github.com/mordante updated https://github.com/llvm/llvm-project/pull/91059
>From 50da5f2ea0b61d2edaf3db8b4ae86481d31cc9bc Mon Sep 17 00:00:00 2001
From: Mark de Wever <koraq at xs4all.nl>
Date: Wed, 17 Apr 2024 21:00:22 +0200
Subject: [PATCH] [libc++][TZDB] Implements zoned_traits.
Implements parts of:
- P0355 Extending chrono to Calendars and Time Zones
---
libcxx/include/CMakeLists.txt | 1 +
libcxx/include/__chrono/zoned_time.h | 55 +++++++++++++++++++
libcxx/include/chrono | 4 ++
libcxx/include/module.modulemap | 1 +
libcxx/modules/std/chrono.inc | 3 +-
.../diagnostics/chrono.nodiscard.verify.cpp | 6 ++
.../const_time_zone_default_zone.pass.cpp | 36 ++++++++++++
.../const_time_zone_locate_zone.pass.cpp | 45 +++++++++++++++
.../types.compile.pass.cpp | 33 +++++++++++
9 files changed, 182 insertions(+), 2 deletions(-)
create mode 100644 libcxx/include/__chrono/zoned_time.h
create mode 100644 libcxx/test/std/time/time.zone/time.zone.zonedtraits/const_time_zone_default_zone.pass.cpp
create mode 100644 libcxx/test/std/time/time.zone/time.zone.zonedtraits/const_time_zone_locate_zone.pass.cpp
create mode 100644 libcxx/test/std/time/time.zone/time.zone.zonedtraits/types.compile.pass.cpp
diff --git a/libcxx/include/CMakeLists.txt b/libcxx/include/CMakeLists.txt
index cbbcc74e21b44..d65b7ce782ebd 100644
--- a/libcxx/include/CMakeLists.txt
+++ b/libcxx/include/CMakeLists.txt
@@ -277,6 +277,7 @@ set(files
__chrono/year_month.h
__chrono/year_month_day.h
__chrono/year_month_weekday.h
+ __chrono/zoned_time.h
__compare/common_comparison_category.h
__compare/compare_partial_order_fallback.h
__compare/compare_strong_order_fallback.h
diff --git a/libcxx/include/__chrono/zoned_time.h b/libcxx/include/__chrono/zoned_time.h
new file mode 100644
index 0000000000000..c6084426ad72b
--- /dev/null
+++ b/libcxx/include/__chrono/zoned_time.h
@@ -0,0 +1,55 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// For information see https://libcxx.llvm.org/DesignDocs/TimeZone.html
+
+#ifndef _LIBCPP___CHRONO_ZONED_TIME_H
+#define _LIBCPP___CHRONO_ZONED_TIME_H
+
+#include <version>
+// Enable the contents of the header only when libc++ was built with experimental features enabled.
+#if !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_TZDB)
+
+# include <__chrono/time_zone.h>
+# include <__chrono/tzdb_list.h>
+# include <__config>
+# include <__fwd/string_view.h>
+
+# if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+# pragma GCC system_header
+# endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+# if _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_TIME_ZONE_DATABASE) && !defined(_LIBCPP_HAS_NO_FILESYSTEM) && \
+ !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+
+namespace chrono {
+
+template <class>
+struct zoned_traits {};
+
+template <>
+struct zoned_traits<const time_zone*> {
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static const time_zone* default_zone() { return chrono::locate_zone("UTC"); }
+ [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static const time_zone* locate_zone(string_view __name) {
+ return chrono::locate_zone(__name);
+ }
+};
+
+} // namespace chrono
+
+# endif // _LIBCPP_STD_VER >= 20 && !defined(_LIBCPP_HAS_NO_TIME_ZONE_DATABASE) && !defined(_LIBCPP_HAS_NO_FILESYSTEM)
+ // && !defined(_LIBCPP_HAS_NO_LOCALIZATION)
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // !defined(_LIBCPP_HAS_NO_EXPERIMENTAL_TZDB)
+
+#endif // _LIBCPP___CHRONO_ZONED_TIME_H
diff --git a/libcxx/include/chrono b/libcxx/include/chrono
index 4d47dc57ba654..c1a92595ff1f5 100644
--- a/libcxx/include/chrono
+++ b/libcxx/include/chrono
@@ -786,6 +786,9 @@ class time_zone {
bool operator==(const time_zone& x, const time_zone& y) noexcept; // C++20
strong_ordering operator<=>(const time_zone& x, const time_zone& y) noexcept; // C++20
+// [time.zone.zonedtraits], class template zoned_traits
+template<class T> struct zoned_traits; // C++20
+
// [time.zone.leap], leap second support
class leap_second { // C++20
public:
@@ -959,6 +962,7 @@ constexpr chrono::year operator ""y(unsigned lo
# include <__chrono/time_zone_link.h>
# include <__chrono/tzdb.h>
# include <__chrono/tzdb_list.h>
+# include <__chrono/zoned_time.h>
# endif
#endif
diff --git a/libcxx/include/module.modulemap b/libcxx/include/module.modulemap
index e03ea989eb371..892d2c6b4af3c 100644
--- a/libcxx/include/module.modulemap
+++ b/libcxx/include/module.modulemap
@@ -1159,6 +1159,7 @@ module std_private_chrono_year [system] { header "__chrono/yea
module std_private_chrono_year_month [system] { header "__chrono/year_month.h" }
module std_private_chrono_year_month_day [system] { header "__chrono/year_month_day.h" }
module std_private_chrono_year_month_weekday [system] { header "__chrono/year_month_weekday.h" }
+module std_private_chrono_zoned_time [system] { header "__chrono/zoned_time.h" }
module std_private_compare_common_comparison_category [system] { header "__compare/common_comparison_category.h" }
module std_private_compare_compare_partial_order_fallback [system] { header "__compare/compare_partial_order_fallback.h" }
diff --git a/libcxx/modules/std/chrono.inc b/libcxx/modules/std/chrono.inc
index f12c2425592e0..87e32afbe4bdc 100644
--- a/libcxx/modules/std/chrono.inc
+++ b/libcxx/modules/std/chrono.inc
@@ -227,11 +227,10 @@ export namespace std {
using std::chrono::choose;
using std::chrono::time_zone;
-# if 0
-
// [time.zone.zonedtraits], class template zoned_traits
using std::chrono::zoned_traits;
+# if 0
// [time.zone.zonedtime], class template zoned_time
using std::chrono::zoned_time;
diff --git a/libcxx/test/libcxx/diagnostics/chrono.nodiscard.verify.cpp b/libcxx/test/libcxx/diagnostics/chrono.nodiscard.verify.cpp
index cba7916ff2c64..6fed41bdb43ed 100644
--- a/libcxx/test/libcxx/diagnostics/chrono.nodiscard.verify.cpp
+++ b/libcxx/test/libcxx/diagnostics/chrono.nodiscard.verify.cpp
@@ -72,4 +72,10 @@ void test() {
leap.date(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
leap.value(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
}
+
+ {
+ using t = std::chrono::zoned_traits<const std::chrono::time_zone*>;
+ t::default_zone(); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ t::locate_zone(""); // expected-warning {{ignoring return value of function declared with 'nodiscard' attribute}}
+ }
}
diff --git a/libcxx/test/std/time/time.zone/time.zone.zonedtraits/const_time_zone_default_zone.pass.cpp b/libcxx/test/std/time/time.zone/time.zone.zonedtraits/const_time_zone_default_zone.pass.cpp
new file mode 100644
index 0000000000000..c6527094bb621
--- /dev/null
+++ b/libcxx/test/std/time/time.zone/time.zone.zonedtraits/const_time_zone_default_zone.pass.cpp
@@ -0,0 +1,36 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: no-filesystem, no-localization, no-tzdb
+
+// XFAIL: libcpp-has-no-experimental-tzdb
+// XFAIL: availability-tzdb-missing
+
+// <chrono>
+
+// template<> struct zoned_traits<const time_zone*>;
+
+// static const time_zone* default_zone();
+
+#include <chrono>
+#include <cassert>
+
+int main(int, char**) {
+ std::same_as<const std::chrono::time_zone*> decltype(auto) tz =
+ std::chrono::zoned_traits<const std::chrono::time_zone*>::default_zone();
+ assert(tz);
+
+ // The time zone "UTC" can be a link, this means tz->name() can be something
+ // differently. For example, "Etc/UTC". Instead validate whether same time
+ // zone is returned by comparing the addresses.
+ const std::chrono::time_zone* expected = std::chrono::locate_zone("UTC");
+ assert(tz == expected);
+
+ return 0;
+}
diff --git a/libcxx/test/std/time/time.zone/time.zone.zonedtraits/const_time_zone_locate_zone.pass.cpp b/libcxx/test/std/time/time.zone/time.zone.zonedtraits/const_time_zone_locate_zone.pass.cpp
new file mode 100644
index 0000000000000..1c8184455f23c
--- /dev/null
+++ b/libcxx/test/std/time/time.zone/time.zone.zonedtraits/const_time_zone_locate_zone.pass.cpp
@@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: no-filesystem, no-localization, no-tzdb
+
+// XFAIL: libcpp-has-no-experimental-tzdb
+// XFAIL: availability-tzdb-missing
+
+// <chrono>
+
+// template<> struct zoned_traits<const time_zone*>;
+
+// static const time_zone* locate_zone(string_view name);
+
+#include <chrono>
+#include <cassert>
+#include <concepts>
+
+#include "assert_macros.h"
+
+static void test(std::string_view name) {
+ std::same_as<const std::chrono::time_zone*> decltype(auto) tz =
+ std::chrono::zoned_traits<const std::chrono::time_zone*>::locate_zone(name);
+
+ const std::chrono::time_zone* expected = std::chrono::locate_zone(name);
+ assert(tz == expected);
+}
+
+int main(int, char**) {
+ test("UTC");
+ test("Europe/Berlin");
+ test("Asia/Hong_Kong");
+
+ TEST_THROWS_TYPE(std::runtime_error,
+ TEST_IGNORE_NODISCARD std::chrono::zoned_traits<const std::chrono::time_zone*>::locate_zone(
+ "there_is_no_time_zone_with_this_name"));
+
+ return 0;
+}
diff --git a/libcxx/test/std/time/time.zone/time.zone.zonedtraits/types.compile.pass.cpp b/libcxx/test/std/time/time.zone/time.zone.zonedtraits/types.compile.pass.cpp
new file mode 100644
index 0000000000000..6e3410795c824
--- /dev/null
+++ b/libcxx/test/std/time/time.zone/time.zone.zonedtraits/types.compile.pass.cpp
@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: no-filesystem, no-localization, no-tzdb
+
+// XFAIL: libcpp-has-no-experimental-tzdb
+// XFAIL: availability-tzdb-missing
+
+// <chrono>
+
+// template<class T> struct zoned_traits {};
+//
+// A specialization for const time_zone* is provided by the implementation:
+// template<> struct zoned_traits<const time_zone*> { ... }
+
+#include <chrono>
+#include <type_traits>
+
+// This test test whether non-specialized versions exhibit the expected
+// behavior. (Note these specializations are not really useful.)
+static_assert(std::is_trivial_v<std::chrono::zoned_traits<int>>);
+static_assert(std::is_trivial_v<std::chrono::zoned_traits<float>>);
+static_assert(std::is_trivial_v<std::chrono::zoned_traits<void*>>);
+
+struct foo {};
+static_assert(std::is_empty_v<std::chrono::zoned_traits<foo>>);
+static_assert(std::is_trivial_v<std::chrono::zoned_traits<foo>>);
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