xref: /llvm-project/libcxx/test/std/time/time.zone/time.zone.db/time.zone.db.access/current_zone.pass.cpp (revision 09e3a360581dc36d0820d3fb6da9bd7cfed87b5d)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 // UNSUPPORTED: c++03, c++11, c++14, c++17
10 // UNSUPPORTED: no-filesystem, no-localization, no-tzdb
11 
12 // XFAIL: libcpp-has-no-experimental-tzdb
13 // XFAIL: availability-tzdb-missing
14 
15 // <chrono>
16 
17 // const time_zone* current_zone();
18 
19 #include <chrono>
20 #include <cassert>
21 #include <stdlib.h>
22 #include <string_view>
23 #include <string>
24 
25 #include "test_macros.h"
26 #include "assert_macros.h"
27 #include "concat_macros.h"
28 
29 #ifdef _WIN32
30 static void set_tz(std::string zone) {
31   // Note Windows does not have setenv, only putenv
32   // https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/putenv-s-wputenv-s?view=msvc-170
33   // Unlike POSIX it does not mention the string of putenv becomes part
34   // of the environment.
35 
36   int status = _putenv_s("TZ", zone.c_str());
37   assert(status == 0);
38 }
39 
40 #else
41 static void set_tz(const std::string& zone) {
42   int status = setenv("TZ", zone.c_str(), 1);
43   assert(status == 0);
44 }
45 #endif
46 
47 static void test_zone(const std::string& zone) {
48   set_tz(zone);
49   const std::chrono::time_zone* tz = std::chrono::current_zone();
50   assert(tz);
51   assert(tz->name() == zone);
52 }
53 
54 static void test_link(const std::string& link, std::string_view zone) {
55   set_tz(link);
56   const std::chrono::time_zone* tz = std::chrono::current_zone();
57   assert(tz);
58   assert(tz->name() == zone);
59 }
60 
61 int main(int, const char**) {
62   const std::chrono::time_zone* tz = std::chrono::current_zone();
63   // Returns a valid time zone, the value depends on the OS settings.
64   assert(tz);
65   // setting the environment to an invalid value returns the value of
66   // the OS setting.
67   set_tz("This is not a time zone");
68   assert(tz == std::chrono::current_zone());
69 
70   const std::chrono::tzdb& db = std::chrono::get_tzdb();
71   for (const auto& zone : db.zones)
72     test_zone(std::string{zone.name()});
73 
74   for (const auto& link : db.links)
75     test_link(std::string{link.name()}, link.target());
76 
77   return 0;
78 }
79