[llvm-branch-commits] [libcxx] [libc++][chrono] Loads leap-seconds.list in tzdb. (PR #82113)

[Louis Dionne via llvm-branch-commits]

================
@@ -0,0 +1,48 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 leap_second;
+
+// constexpr sys_seconds date() const noexcept;
+
+#include <cassert>
+#include <chrono>
+
+#include "test_macros.h"
+
+// Add the include path required by test_chrono_leap_second.h when using libc++.
+// ADDITIONAL_COMPILE_FLAGS(stdlib=libc++): -I %S/../../../../../../src/include
+#include "test_chrono_leap_second.h"
+
+constexpr bool test(const std::chrono::leap_second leap_second, std::chrono::sys_seconds expected) {
+  std::same_as<std::chrono::sys_seconds> auto date = leap_second.date();
+  assert(date == expected);
+  static_assert(noexcept(leap_second.date()));
+
+  return true;
+}
+
+int main(int, const char**) {
+  const std::chrono::tzdb& tzdb = std::chrono::get_tzdb();
----------------
ldionne wrote:

I think we have two tests here. First, we have a test with `test_leap_second_create(std::chrono::sys_seconds{std::chrono::seconds{0}}, std::chrono::seconds{1})` and we should test it both at runtime and at compile-time.

Second, we have a test with the actual value obtained from `get_tzdb()` and we can only test it at runtime.

```c++
constexpr bool test() {
  auto leap_second = test_leap_second_create(std::chrono::sys_seconds{std::chrono::seconds{0}}, std::chrono::seconds{1});
  std::same_as<std::chrono::sys_seconds> auto date = leap_second.date();
  assert(date == std::chrono::sys_seconds{std::chrono::seconds{0}});
  // etc..
}

int main() {
  test();
  static_assert(test());

  // test with the real tzdb
  {
    const auto& tzdb = get_tzdb();
    ...
  }
}
```

This would apply to the other test files as well.

https://github.com/llvm/llvm-project/pull/82113