diff options
Diffstat (limited to 'absl/time/internal/cctz/src/time_zone_lookup_test.cc')
| -rw-r--r-- | absl/time/internal/cctz/src/time_zone_lookup_test.cc | 100 |
1 files changed, 95 insertions, 5 deletions
diff --git a/absl/time/internal/cctz/src/time_zone_lookup_test.cc b/absl/time/internal/cctz/src/time_zone_lookup_test.cc index f28e7f853b69..e84b9469aa08 100644 --- a/absl/time/internal/cctz/src/time_zone_lookup_test.cc +++ b/absl/time/internal/cctz/src/time_zone_lookup_test.cc @@ -16,7 +16,9 @@ #include <chrono> #include <cstddef> +#include <cstdlib> #include <future> +#include <limits> #include <string> #include <thread> #include <vector> @@ -925,7 +927,7 @@ TEST(MakeTime, Normalization) { EXPECT_EQ(tp, convert(civil_second(2009, 2, 13, 18, 30, 90), tz)); // second } -// NOTE: Run this with --copt=-ftrapv to detect overflow problems. +// NOTE: Run this with -ftrapv to detect overflow problems. TEST(MakeTime, SysSecondsLimits) { const char RFC3339[] = "%Y-%m-%dT%H:%M:%S%Ez"; const time_zone utc = utc_time_zone(); @@ -991,19 +993,107 @@ TEST(MakeTime, SysSecondsLimits) { tp = convert(civil_second::min(), west); EXPECT_EQ(time_point<absl::time_internal::cctz::seconds>::min(), tp); + // Some similar checks for the "libc" time-zone implementation. if (sizeof(std::time_t) >= 8) { // Checks that "tm_year + 1900", as used by the "libc" implementation, // can produce year values beyond the range on an int without overflow. #if defined(_WIN32) || defined(_WIN64) - // localtime_s() and gmtime_s() don't believe in years past 3000. + // localtime_s() and gmtime_s() don't believe in years outside [1970:3000]. #else - const time_zone libc_utc = LoadZone("libc:UTC"); - tp = convert(civil_year(year_t{2147483648}), libc_utc); - EXPECT_EQ("2147483648-01-01T00:00:00+00:00", format(RFC3339, tp, libc_utc)); + const time_zone utc = LoadZone("libc:UTC"); + const year_t max_tm_year = year_t{std::numeric_limits<int>::max()} + 1900; + tp = convert(civil_second(max_tm_year, 12, 31, 23, 59, 59), utc); + EXPECT_EQ("2147485547-12-31T23:59:59+00:00", format(RFC3339, tp, utc)); + const year_t min_tm_year = year_t{std::numeric_limits<int>::min()} + 1900; + tp = convert(civil_second(min_tm_year, 1, 1, 0, 0, 0), utc); + EXPECT_EQ("-2147481748-01-01T00:00:00+00:00", format(RFC3339, tp, utc)); #endif } } +TEST(MakeTime, LocalTimeLibC) { + // Checks that cctz and libc agree on transition points in [1970:2037]. + // + // We limit this test case to environments where: + // 1) we know how to change the time zone used by localtime()/mktime(), + // 2) cctz and localtime()/mktime() will use similar-enough tzdata, and + // 3) we have some idea about how mktime() behaves during transitions. +#if defined(__linux__) + const char* const ep = getenv("TZ"); + std::string tz_name = (ep != nullptr) ? ep : ""; + for (const char* const* np = kTimeZoneNames; *np != nullptr; ++np) { + ASSERT_EQ(0, setenv("TZ", *np, 1)); // change what "localtime" means + const auto zi = local_time_zone(); + const auto lc = LoadZone("libc:localtime"); + time_zone::civil_transition trans; + for (auto tp = zi.lookup(civil_second()).trans; + zi.next_transition(tp, &trans); + tp = zi.lookup(trans.to).trans) { + const auto fcl = zi.lookup(trans.from); + const auto tcl = zi.lookup(trans.to); + civil_second cs; // compare cs in zi and lc + if (fcl.kind == time_zone::civil_lookup::UNIQUE) { + if (tcl.kind == time_zone::civil_lookup::UNIQUE) { + // Both unique; must be an is_dst or abbr change. + ASSERT_EQ(trans.from, trans.to); + const auto trans = fcl.trans; + const auto tal = zi.lookup(trans); + const auto tprev = trans - absl::time_internal::cctz::seconds(1); + const auto pal = zi.lookup(tprev); + if (pal.is_dst == tal.is_dst) { + ASSERT_STRNE(pal.abbr, tal.abbr); + } + continue; + } + ASSERT_EQ(time_zone::civil_lookup::REPEATED, tcl.kind); + cs = trans.to; + } else { + ASSERT_EQ(time_zone::civil_lookup::UNIQUE, tcl.kind); + ASSERT_EQ(time_zone::civil_lookup::SKIPPED, fcl.kind); + cs = trans.from; + } + if (cs.year() > 2037) break; // limit test time (and to 32-bit time_t) + const auto cl_zi = zi.lookup(cs); + if (zi.lookup(cl_zi.pre).is_dst == zi.lookup(cl_zi.post).is_dst) { + // The "libc" implementation cannot correctly classify transitions + // that don't change the "tm_isdst" flag. In Europe/Volgograd, for + // example, there is a SKIPPED transition from +03 to +04 with dst=F + // on both sides ... + // 1540681199 = 2018-10-28 01:59:59 +03:00:00 [dst=F off=10800] + // 1540681200 = 2018-10-28 03:00:00 +04:00:00 [dst=F off=14400] + // but std::mktime(2018-10-28 02:00:00, tm_isdst=0) fails, unlike, + // say, the similar Europe/Chisinau transition from +02 to +03 ... + // 1521935999 = 2018-03-25 01:59:59 +02:00:00 [dst=F off=7200] + // 1521936000 = 2018-03-25 03:00:00 +03:00:00 [dst=T off=10800] + // where std::mktime(2018-03-25 02:00:00, tm_isdst=0) succeeds and + // returns 1521936000. + continue; + } + if (cs == civil_second(2037, 10, 4, 2, 0, 0)) { + const std::string tzname = *np; + if (tzname == "Africa/Casablanca" || tzname == "Africa/El_Aaiun") { + // The "libc" implementation gets this transition wrong (at least + // until 2018g when it was removed), returning an offset of 3600 + // instead of 0. TODO: Revert this when 2018g is ubiquitous. + continue; + } + } + const auto cl_lc = lc.lookup(cs); + SCOPED_TRACE(testing::Message() << "For " << cs << " in " << *np); + EXPECT_EQ(cl_zi.kind, cl_lc.kind); + EXPECT_EQ(cl_zi.pre, cl_lc.pre); + EXPECT_EQ(cl_zi.trans, cl_lc.trans); + EXPECT_EQ(cl_zi.post, cl_lc.post); + } + } + if (ep == nullptr) { + ASSERT_EQ(0, unsetenv("TZ")); + } else { + ASSERT_EQ(0, setenv("TZ", tz_name.c_str(), 1)); + } +#endif +} + TEST(NextTransition, UTC) { const auto tz = utc_time_zone(); time_zone::civil_transition trans; |