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, has-no-zdump
11// REQUIRES: long_tests
12
13// XFAIL: libcpp-has-no-experimental-tzdb
14// XFAIL: availability-tzdb-missing
15
16#include <chrono>
17#include <format>
18#include <fstream>
19#include <cassert>
20
21#include "filesystem_test_helper.h"
22#include "assert_macros.h"
23#include "concat_macros.h"
24
25// The year range to validate. The dates used in practice are expected to be
26// inside the tested range.
27constexpr std::chrono::year first{1800};
28constexpr std::chrono::year last{sizeof(time_t) == 8 ? 2100 : 2037};
29
30// A custom sys_info class that also stores the name of the time zone.
31// Its formatter matches the output of zdump.
32struct sys_info : public std::chrono::sys_info {
33 sys_info(std::string_view name_, std::chrono::sys_info info) : std::chrono::sys_info{info}, name{name_} {}
34
35 std::string name;
36};
37
38template <>
39struct std::formatter<sys_info, char> {
40 template <class ParseContext>
41 constexpr typename ParseContext::iterator parse(ParseContext& ctx) {
42 return ctx.begin();
43 }
44
45 template <class FormatContext>
46 typename FormatContext::iterator format(const sys_info& info, FormatContext& ctx) const {
47 using namespace std::literals::chrono_literals;
48
49 // Every "sys_info" entry of zdump consists of 2 lines.
50 // - 1 for first second of the range
51 // - 1 for last second of the range
52 // For example:
53 // Africa/Casablanca Sun Mar 25 02:00:00 2018 UT = Sun Mar 25 03:00:00 2018 +01 isdst=1 gmtoff=3600
54 // Africa/Casablanca Sun May 13 01:59:59 2018 UT = Sun May 13 02:59:59 2018 +01 isdst=1 gmtoff=3600
55
56 if (info.begin != std::chrono::sys_seconds::min())
57 ctx.advance_to(std::format_to(
58 ctx.out(),
59 "{} {:%a %b %e %H:%M:%S %Y} UT = {:%a %b %e %H:%M:%S %Y} {} isdst={:d} gmtoff={:%Q}\n",
60 info.name,
61 info.begin,
62 info.begin + info.offset,
63 info.abbrev,
64 info.save != 0s,
65 info.offset));
66
67 if (info.end != std::chrono::sys_seconds::max())
68 ctx.advance_to(std::format_to(
69 ctx.out(),
70 "{} {:%a %b %e %H:%M:%S %Y} UT = {:%a %b %e %H:%M:%S %Y} {} isdst={:d} gmtoff={:%Q}\n",
71 info.name,
72 info.end - 1s,
73 info.end - 1s + info.offset,
74 info.abbrev,
75 info.save != 0s,
76 info.offset));
77
78 return ctx.out();
79 }
80};
81
82void process(std::ostream& stream, const std::chrono::time_zone& zone) {
83 using namespace std::literals::chrono_literals;
84
85 constexpr auto begin = std::chrono::time_point_cast<std::chrono::seconds>(
86 static_cast<std::chrono::sys_days>(std::chrono::year_month_day{first, std::chrono::January, 1d}));
87 constexpr auto end = std::chrono::time_point_cast<std::chrono::seconds>(
88 static_cast<std::chrono::sys_days>(std::chrono::year_month_day{last, std::chrono::January, 1d}));
89
90 std::chrono::sys_seconds s = begin;
91 do {
92 sys_info info{zone.name(), zone.get_info(s)};
93
94 if (info.end >= end)
95 info.end = std::chrono::sys_seconds::max();
96
97 stream << std::format("{}", info);
98 s = info.end;
99 } while (s != std::chrono::sys_seconds::max());
100}
101
102// This test compares the output of the zdump against the output based on the
103// standard library implementation. It tests all available time zones and
104// validates them. The specification of how to use the IANA database is limited
105// and the real database contains quite a number of "interesting" cases.
106int main(int, const char**) {
107 scoped_test_env env;
108 const std::string file = env.create_file("zdump.txt");
109
110 const std::chrono::tzdb& tzdb = std::chrono::get_tzdb();
111 for (const auto& zone : tzdb.zones) {
112 std::stringstream libcxx;
113 process(libcxx, zone);
114
115 int result = std::system(std::format("zdump -V -c{},{} {} > {}", first, last, zone.name(), file).c_str());
116 assert(result == 0);
117
118 std::stringstream zdump;
119 zdump << std::ifstream(file).rdbuf();
120
121 TEST_REQUIRE(
122 libcxx.str() == zdump.str(),
123 TEST_WRITE_CONCATENATED("\nTZ=", zone.name(), "\nlibc++\n", libcxx.str(), "|\n\nzdump\n", zdump.str(), "|"));
124 }
125
126 return 0;
127}
128

source code of libcxx/test/std/time/time.zone/time.zone.timezone/time.zone.members/sys_info.zdump.pass.cpp