[libcxx-commits] [libcxx] [libc++][chrono] Adds the sys_info class. (PR #85619)

[Mark de Wever via libcxx-commits]

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@@ -0,0 +1,185 @@
+//===----------------------------------------------------------------------===//
+//
+// 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-incomplete-tzdb
+// XFAIL: availability-tzdb-missing
+
+// <chrono>
+
+// class time_zone;
+
+// template <class _Duration>
+//   sys_info get_info(const sys_time<_Duration>& time) const;
+
+// The time zone database contains of the following entries
+// - Zones,
+// - Rules,
+// - Links, and
+// - Leapseconds.
+//
+// The public tzdb struct stores all entries except the Rules. How
+// implementations keep track of the Rules is not specified. When the sys_info
+// for a time_zone is requested it needs to use the correct Rules. This lookup
+// cannot rely on 'get_tzdb()` since that returns the most recently loaded
+// database.
+//
+// A reload could change the rules of a time zone or the time zone could no
+// longer be present in the current database. These two conditions are tested.
+//
+// It is possible the tzdb entry has been removed by the user from the tzdb_list
+// after a reload. This is UB and not tested.
+
+#include <cassert>
+#include <fstream>
+#include <chrono>
+
+#include "test_macros.h"
+#include "assert_macros.h"
+#include "concat_macros.h"
+#include "filesystem_test_helper.h"
+#include "test_tzdb.h"
+
+/***** ***** HELPERS ***** *****/
+
+scoped_test_env env;
+[[maybe_unused]] const std::filesystem::path dir = env.create_dir("zoneinfo");
+const std::filesystem::path file                 = env.create_file("zoneinfo/tzdata.zi");
+
+std::string_view std::chrono::__libcpp_tzdb_directory() {
+  static std::string result = dir.string();
+  return result;
+}
+
+static void write(std::string_view input) {
+  static int version = 0;
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mordante wrote:

That should automatically happen in the destructor. Or am I overlooking something?

https://github.com/llvm/llvm-project/pull/85619