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Import of CCTZ from GitHub.

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PiperOrigin-RevId: 538241594
Change-Id: Ie6f0d913bcf07dea2f33e47198ba952b3800d70e
This commit is contained in:
Abseil Team
2023-06-06 11:23:59 -07:00
committed by Copybara-Service
parent 66406fdf15
commit 1285ca4b4f
3 changed files with 49 additions and 35 deletions
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2
absl/time/internal/cctz/src/time_zone_if.cc
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@@ -26,6 +26,8 @@ namespace cctz {
std::unique_ptr<TimeZoneIf> TimeZoneIf::Load(const std::string& name) {
// Support "libc:localtime" and "libc:*" to access the legacy
// localtime and UTC support respectively from the C library.
// NOTE: The "libc:*" zones are internal, test-only interfaces, and
// are subject to change/removal without notice. Do not use them.
if (name.compare(0, 5, "libc:") == 0) {
return std::unique_ptr<TimeZoneIf>(new TimeZoneLibC(name.substr(5)));
}

61
absl/time/internal/cctz/src/time_zone_libc.cc
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@@ -125,31 +125,30 @@ inline std::tm* local_time(const std::time_t* timep, std::tm* result) {
#endif
}
// Converts a civil second and "dst" flag into a time_t and UTC offset.
// Converts a civil second and "dst" flag into a time_t and a struct tm.
// Returns false if time_t cannot represent the requested civil second.
// Caller must have already checked that cs.year() will fit into a tm_year.
bool make_time(const civil_second& cs, int is_dst, std::time_t* t, int* off) {
std::tm tm;
tm.tm_year = static_cast<int>(cs.year() - year_t{1900});
tm.tm_mon = cs.month() - 1;
tm.tm_mday = cs.day();
tm.tm_hour = cs.hour();
tm.tm_min = cs.minute();
tm.tm_sec = cs.second();
tm.tm_isdst = is_dst;
*t = std::mktime(&tm);
bool make_time(const civil_second& cs, int is_dst, std::time_t* t,
std::tm* tm) {
tm->tm_year = static_cast<int>(cs.year() - year_t{1900});
tm->tm_mon = cs.month() - 1;
tm->tm_mday = cs.day();
tm->tm_hour = cs.hour();
tm->tm_min = cs.minute();
tm->tm_sec = cs.second();
tm->tm_isdst = is_dst;
*t = std::mktime(tm);
if (*t == std::time_t{-1}) {
std::tm tm2;
const std::tm* tmp = local_time(t, &tm2);
if (tmp == nullptr || tmp->tm_year != tm.tm_year ||
tmp->tm_mon != tm.tm_mon || tmp->tm_mday != tm.tm_mday ||
tmp->tm_hour != tm.tm_hour || tmp->tm_min != tm.tm_min ||
tmp->tm_sec != tm.tm_sec) {
if (tmp == nullptr || tmp->tm_year != tm->tm_year ||
tmp->tm_mon != tm->tm_mon || tmp->tm_mday != tm->tm_mday ||
tmp->tm_hour != tm->tm_hour || tmp->tm_min != tm->tm_min ||
tmp->tm_sec != tm->tm_sec) {
// A true error (not just one second before the epoch).
return false;
}
}
*off = static_cast<int>(tm_gmtoff(tm));
return true;
}
@@ -254,33 +253,37 @@ time_zone::civil_lookup TimeZoneLibC::MakeTime(const civil_second& cs) const {
// We probe with "is_dst" values of 0 and 1 to try to distinguish unique
// civil seconds from skipped or repeated ones. This is not always possible
// however, as the "dst" flag does not change over some offset transitions.
// We are also subject to the vagaries of mktime() implementations.
// We are also subject to the vagaries of mktime() implementations. For
// example, some implementations treat "tm_isdst" as a demand (useless),
// and some as a disambiguator (useful).
std::time_t t0, t1;
int offset0, offset1;
if (make_time(cs, 0, &t0, &offset0) && make_time(cs, 1, &t1, &offset1)) {
if (t0 == t1) {
std::tm tm0, tm1;
if (make_time(cs, 0, &t0, &tm0) && make_time(cs, 1, &t1, &tm1)) {
if (tm0.tm_isdst == tm1.tm_isdst) {
// The civil time was singular (pre == trans == post).
const time_point<seconds> tp = FromUnixSeconds(t0);
const time_point<seconds> tp = FromUnixSeconds(tm0.tm_isdst ? t1 : t0);
return {time_zone::civil_lookup::UNIQUE, tp, tp, tp};
}
if (t0 > t1) {
int offset = tm_gmtoff(tm0);
if (t0 < t1) { // negative DST
std::swap(t0, t1);
std::swap(offset0, offset1);
offset = tm_gmtoff(tm1);
}
const std::time_t tt = find_trans(t0, t1, offset1);
const std::time_t tt = find_trans(t1, t0, offset);
const time_point<seconds> trans = FromUnixSeconds(tt);
if (offset0 < offset1) {
if (tm0.tm_isdst) {
// The civil time did not exist (pre >= trans > post).
const time_point<seconds> pre = FromUnixSeconds(t1);
const time_point<seconds> post = FromUnixSeconds(t0);
const time_point<seconds> pre = FromUnixSeconds(t0);
const time_point<seconds> post = FromUnixSeconds(t1);
return {time_zone::civil_lookup::SKIPPED, pre, trans, post};
}
// The civil time was ambiguous (pre < trans <= post).
const time_point<seconds> pre = FromUnixSeconds(t0);
const time_point<seconds> post = FromUnixSeconds(t1);
const time_point<seconds> pre = FromUnixSeconds(t1);
const time_point<seconds> post = FromUnixSeconds(t0);
return {time_zone::civil_lookup::REPEATED, pre, trans, post};
}

21
absl/time/internal/cctz/src/time_zone_lookup_test.cc
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@@ -1034,16 +1034,16 @@ TEST(MakeTime, SysSecondsLimits) {
const time_zone cut = 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), cut);
#if defined(__FreeBSD__) || defined(__OpenBSD__)
// The BSD gmtime_r() fails on extreme positive tm_year values.
#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__EMSCRIPTEN__)
// Some gmtime_r() impls fail on extreme positive values.
#else
EXPECT_EQ("2147485547-12-31T23:59:59+00:00",
absl::time_internal::cctz::format(RFC3339, tp, cut));
#endif
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), cut);
#if defined(__Fuchsia__)
// Fuchsia's gmtime_r() fails on extreme negative values (fxbug.dev/78527).
#if defined(__Fuchsia__) || defined(__EMSCRIPTEN__)
// Some gmtime_r() impls fail on extreme negative values (fxbug.dev/78527).
#else
EXPECT_EQ("-2147481748-01-01T00:00:00+00:00",
absl::time_internal::cctz::format(RFC3339, tp, cut));
@@ -1072,7 +1072,7 @@ TEST(MakeTime, LocalTimeLibC) {
tp = zi.lookup(transition.to).trans) {
const auto fcl = zi.lookup(transition.from);
const auto tcl = zi.lookup(transition.to);
civil_second cs; // compare cs in zi and lc
civil_second cs, us; // compare cs and us 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.
@@ -1088,12 +1088,14 @@ TEST(MakeTime, LocalTimeLibC) {
}
ASSERT_EQ(time_zone::civil_lookup::REPEATED, tcl.kind);
cs = transition.to;
us = transition.from;
} else {
ASSERT_EQ(time_zone::civil_lookup::UNIQUE, tcl.kind);
ASSERT_EQ(time_zone::civil_lookup::SKIPPED, fcl.kind);
cs = transition.from;
us = transition.to;
}
if (cs.year() > 2037) break; // limit test time (and to 32-bit time_t)
if (us.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
@@ -1125,6 +1127,13 @@ TEST(MakeTime, LocalTimeLibC) {
EXPECT_EQ(cl_zi.pre, cl_lc.pre);
EXPECT_EQ(cl_zi.trans, cl_lc.trans);
EXPECT_EQ(cl_zi.post, cl_lc.post);
const auto ucl_zi = zi.lookup(us);
const auto ucl_lc = lc.lookup(us);
SCOPED_TRACE(testing::Message() << "For " << us << " in " << *np);
EXPECT_EQ(ucl_zi.kind, ucl_lc.kind);
EXPECT_EQ(ucl_zi.pre, ucl_lc.pre);
EXPECT_EQ(ucl_zi.trans, ucl_lc.trans);
EXPECT_EQ(ucl_zi.post, ucl_lc.post);
}
}
if (ep == nullptr) {