Creation of LTS branch "lts_2018_12_18"

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GitOrigin-RevId: 44b0fafc62d9b8f192e8180cbe9c4b806b339d57
Change-Id: I2c427b5b41b2d34101922048b00f3d9dafcb498d

1 files changed, 67 insertions, 47 deletions

diff --git a/absl/time/internal/cctz/src/time_zone_info.cc b/absl/time/internal/cctz/src/time_zone_info.cc
index 7f5a8fad..e19d1d2d 100644
--- a/absl/time/internal/cctz/src/time_zone_info.cc
+++ b/absl/time/internal/cctz/src/time_zone_info.cc
@@ -50,7 +50,7 @@
 #include "time_zone_posix.h"
 
 namespace absl {
-inline namespace lts_2018_06_20 {
+inline namespace lts_2018_12_18 {
 namespace time_internal {
 namespace cctz {
 
@@ -141,7 +141,7 @@ std::int_fast64_t TransOffset(bool leap_year, int jan1_weekday,
   return (days * kSecsPerDay) + pt.time.offset;
 }
 
-inline time_zone::civil_lookup MakeUnique(const time_point<sys_seconds>& tp) {
+inline time_zone::civil_lookup MakeUnique(const time_point<seconds>& tp) {
   time_zone::civil_lookup cl;
   cl.kind = time_zone::civil_lookup::UNIQUE;
   cl.pre = cl.trans = cl.post = tp;
@@ -180,21 +180,20 @@ inline civil_second YearShift(const civil_second& cs, year_t shift) {
 }  // namespace
 
 // What (no leap-seconds) UTC+seconds zoneinfo would look like.
-bool TimeZoneInfo::ResetToBuiltinUTC(const sys_seconds& offset) {
+bool TimeZoneInfo::ResetToBuiltinUTC(const seconds& offset) {
   transition_types_.resize(1);
   TransitionType& tt(transition_types_.back());
   tt.utc_offset = static_cast<std::int_least32_t>(offset.count());
   tt.is_dst = false;
   tt.abbr_index = 0;
 
-  // We temporarily add some redundant, contemporary (2012 through 2021)
+  // We temporarily add some redundant, contemporary (2013 through 2023)
   // transitions for performance reasons.  See TimeZoneInfo::LocalTime().
   // TODO: Fix the performance issue and remove the extra transitions.
   transitions_.clear();
   transitions_.reserve(12);
   for (const std::int_fast64_t unix_time : {
            -(1LL << 59),  // BIG_BANG
-           1325376000LL,  // 2012-01-01T00:00:00+00:00
            1356998400LL,  // 2013-01-01T00:00:00+00:00
            1388534400LL,  // 2014-01-01T00:00:00+00:00
            1420070400LL,  // 2015-01-01T00:00:00+00:00
@@ -204,6 +203,8 @@ bool TimeZoneInfo::ResetToBuiltinUTC(const sys_seconds& offset) {
            1546300800LL,  // 2019-01-01T00:00:00+00:00
            1577836800LL,  // 2020-01-01T00:00:00+00:00
            1609459200LL,  // 2021-01-01T00:00:00+00:00
+           1640995200LL,  // 2022-01-01T00:00:00+00:00
+           1672531200LL,  // 2023-01-01T00:00:00+00:00
            2147483647LL,  // 2^31 - 1
        }) {
     Transition& tr(*transitions_.emplace(transitions_.end()));
@@ -219,8 +220,8 @@ bool TimeZoneInfo::ResetToBuiltinUTC(const sys_seconds& offset) {
   future_spec_.clear();  // never needed for a fixed-offset zone
   extended_ = false;
 
-  tt.civil_max = LocalTime(sys_seconds::max().count(), tt).cs;
-  tt.civil_min = LocalTime(sys_seconds::min().count(), tt).cs;
+  tt.civil_max = LocalTime(seconds::max().count(), tt).cs;
+  tt.civil_min = LocalTime(seconds::min().count(), tt).cs;
 
   transitions_.shrink_to_fit();
   return true;
@@ -286,7 +287,7 @@ bool TimeZoneInfo::EquivTransitions(std::uint_fast8_t tt1_index,
   return true;
 }
 
-// Use the POSIX-TZ-environment-variable-style std::string to handle times
+// Use the POSIX-TZ-environment-variable-style string to handle times
 // in years after the last transition stored in the zoneinfo data.
 void TimeZoneInfo::ExtendTransitions(const std::string& name,
                                      const Header& hdr) {
@@ -520,6 +521,13 @@ bool TimeZoneInfo::Load(const std::string& name, ZoneInfoSource* zip) {
 
   // We don't check for EOF so that we're forwards compatible.
 
+  // If we did not find version information during the standard loading
+  // process (as of tzh_version '3' that is unsupported), then ask the
+  // ZoneInfoSource for any out-of-bound version std::string it may be privy to.
+  if (version_.empty()) {
+    version_ = zip->Version();
+  }
+
   // Trim redundant transitions. zic may have added these to work around
   // differences between the glibc and reference implementations (see
   // zic.c:dontmerge) and the Qt library (see zic.c:WORK_AROUND_QTBUG_53071).
@@ -566,10 +574,10 @@ bool TimeZoneInfo::Load(const std::string& name, ZoneInfoSource* zip) {
   }
 
   // Compute the maximum/minimum civil times that can be converted to a
-  // time_point<sys_seconds> for each of the zone's transition types.
+  // time_point<seconds> for each of the zone's transition types.
   for (auto& tt : transition_types_) {
-    tt.civil_max = LocalTime(sys_seconds::max().count(), tt).cs;
-    tt.civil_min = LocalTime(sys_seconds::min().count(), tt).cs;
+    tt.civil_max = LocalTime(seconds::max().count(), tt).cs;
+    tt.civil_min = LocalTime(seconds::min().count(), tt).cs;
   }
 
   transitions_.shrink_to_fit();
@@ -606,6 +614,10 @@ class FileZoneInfoSource : public ZoneInfoSource {
     if (rc == 0) len_ -= offset;
     return rc;
   }
+  std::string Version() const override {
+    // TODO: It would nice if the zoneinfo data included the tzdb version.
+    return std::string();
+  }
 
  protected:
   explicit FileZoneInfoSource(
@@ -655,14 +667,15 @@ std::unique_ptr<ZoneInfoSource> FileZoneInfoSource::Open(
   return std::unique_ptr<ZoneInfoSource>(new FileZoneInfoSource(fp, length));
 }
 
-#if defined(__ANDROID__)
 class AndroidZoneInfoSource : public FileZoneInfoSource {
  public:
   static std::unique_ptr<ZoneInfoSource> Open(const std::string& name);
+  std::string Version() const override { return version_; }
 
  private:
-  explicit AndroidZoneInfoSource(FILE* fp, std::size_t len)
-      : FileZoneInfoSource(fp, len) {}
+  explicit AndroidZoneInfoSource(FILE* fp, std::size_t len, const char* vers)
+      : FileZoneInfoSource(fp, len), version_(vers) {}
+  std::string version_;
 };
 
 std::unique_ptr<ZoneInfoSource> AndroidZoneInfoSource::Open(
@@ -670,6 +683,7 @@ std::unique_ptr<ZoneInfoSource> AndroidZoneInfoSource::Open(
   // Use of the "file:" prefix is intended for testing purposes only.
   if (name.compare(0, 5, "file:") == 0) return Open(name.substr(5));
 
+#if defined(__ANDROID__)
   // See Android's libc/tzcode/bionic.cpp for additional information.
   for (const char* tzdata : {"/data/misc/zoneinfo/current/tzdata",
                              "/system/usr/share/zoneinfo/tzdata"}) {
@@ -679,6 +693,7 @@ std::unique_ptr<ZoneInfoSource> AndroidZoneInfoSource::Open(
     char hbuf[24];  // covers header.zonetab_offset too
     if (fread(hbuf, 1, sizeof(hbuf), fp.get()) != sizeof(hbuf)) continue;
     if (strncmp(hbuf, "tzdata", 6) != 0) continue;
+    const char* vers = (hbuf[11] == '\0') ? hbuf + 6 : "";
     const std::int_fast32_t index_offset = Decode32(hbuf + 12);
     const std::int_fast32_t data_offset = Decode32(hbuf + 16);
     if (index_offset < 0 || data_offset < index_offset) continue;
@@ -699,13 +714,13 @@ std::unique_ptr<ZoneInfoSource> AndroidZoneInfoSource::Open(
       if (strcmp(name.c_str(), ebuf) == 0) {
         if (fseek(fp.get(), static_cast<long>(start), SEEK_SET) != 0) break;
         return std::unique_ptr<ZoneInfoSource>(new AndroidZoneInfoSource(
-            fp.release(), static_cast<std::size_t>(length)));
+            fp.release(), static_cast<std::size_t>(length), vers));
       }
     }
   }
+#endif  // __ANDROID__
   return nullptr;
 }
-#endif
 
 }  // namespace
 
@@ -714,7 +729,7 @@ bool TimeZoneInfo::Load(const std::string& name) {
   // zone never fails because the simple, fixed-offset state can be
   // internally generated. Note that this depends on our choice to not
   // accept leap-second encoded ("right") zoneinfo.
-  auto offset = sys_seconds::zero();
+  auto offset = seconds::zero();
   if (FixedOffsetFromName(name, &offset)) {
     return ResetToBuiltinUTC(offset);
   }
@@ -723,9 +738,7 @@ bool TimeZoneInfo::Load(const std::string& name) {
   auto zip = cctz_extension::zone_info_source_factory(
       name, [](const std::string& name) -> std::unique_ptr<ZoneInfoSource> {
         if (auto zip = FileZoneInfoSource::Open(name)) return zip;
-#if defined(__ANDROID__)
         if (auto zip = AndroidZoneInfoSource::Open(name)) return zip;
-#endif
         return nullptr;
       });
   return zip != nullptr && Load(name, zip.get());
@@ -756,14 +769,14 @@ time_zone::civil_lookup TimeZoneInfo::TimeLocal(const civil_second& cs,
                                                 year_t c4_shift) const {
   assert(last_year_ - 400 < cs.year() && cs.year() <= last_year_);
   time_zone::civil_lookup cl = MakeTime(cs);
-  if (c4_shift > sys_seconds::max().count() / kSecsPer400Years) {
-    cl.pre = cl.trans = cl.post = time_point<sys_seconds>::max();
+  if (c4_shift > seconds::max().count() / kSecsPer400Years) {
+    cl.pre = cl.trans = cl.post = time_point<seconds>::max();
   } else {
-    const auto offset = sys_seconds(c4_shift * kSecsPer400Years);
-    const auto limit = time_point<sys_seconds>::max() - offset;
+    const auto offset = seconds(c4_shift * kSecsPer400Years);
+    const auto limit = time_point<seconds>::max() - offset;
     for (auto* tp : {&cl.pre, &cl.trans, &cl.post}) {
       if (*tp > limit) {
-        *tp = time_point<sys_seconds>::max();
+        *tp = time_point<seconds>::max();
       } else {
         *tp += offset;
       }
@@ -773,7 +786,7 @@ time_zone::civil_lookup TimeZoneInfo::TimeLocal(const civil_second& cs,
 }
 
 time_zone::absolute_lookup TimeZoneInfo::BreakTime(
-    const time_point<sys_seconds>& tp) const {
+    const time_point<seconds>& tp) const {
   std::int_fast64_t unix_time = ToUnixSeconds(tp);
   const std::size_t timecnt = transitions_.size();
   assert(timecnt != 0);  // We always add a transition.
@@ -789,7 +802,7 @@ time_zone::absolute_lookup TimeZoneInfo::BreakTime(
       const std::int_fast64_t diff =
           unix_time - transitions_[timecnt - 1].unix_time;
       const year_t shift = diff / kSecsPer400Years + 1;
-      const auto d = sys_seconds(shift * kSecsPer400Years);
+      const auto d = seconds(shift * kSecsPer400Years);
       time_zone::absolute_lookup al = BreakTime(tp - d);
       al.cs = YearShift(al.cs, shift * 400);
       return al;
@@ -848,7 +861,7 @@ time_zone::civil_lookup TimeZoneInfo::MakeTime(const civil_second& cs) const {
     if (tr->prev_civil_sec >= cs) {
       // Before first transition, so use the default offset.
       const TransitionType& tt(transition_types_[default_transition_type_]);
-      if (cs < tt.civil_min) return MakeUnique(time_point<sys_seconds>::min());
+      if (cs < tt.civil_min) return MakeUnique(time_point<seconds>::min());
       return MakeUnique(cs - (civil_second() + tt.utc_offset));
     }
     // tr->prev_civil_sec < cs < tr->civil_sec
@@ -865,7 +878,7 @@ time_zone::civil_lookup TimeZoneInfo::MakeTime(const civil_second& cs) const {
         return TimeLocal(YearShift(cs, shift * -400), shift);
       }
       const TransitionType& tt(transition_types_[tr->type_index]);
-      if (cs > tt.civil_max) return MakeUnique(time_point<sys_seconds>::max());
+      if (cs > tt.civil_max) return MakeUnique(time_point<seconds>::max());
       return MakeUnique(tr->unix_time + (cs - tr->civil_sec));
     }
     // tr->civil_sec <= cs <= tr->prev_civil_sec
@@ -886,17 +899,20 @@ time_zone::civil_lookup TimeZoneInfo::MakeTime(const civil_second& cs) const {
   return MakeUnique(tr->unix_time + (cs - tr->civil_sec));
 }
 
+std::string TimeZoneInfo::Version() const {
+  return version_;
+}
+
 std::string TimeZoneInfo::Description() const {
   std::ostringstream oss;
-  // TODO: It would nice if the zoneinfo data included the zone name.
-  // TODO: It would nice if the zoneinfo data included the tzdb version.
   oss << "#trans=" << transitions_.size();
   oss << " #types=" << transition_types_.size();
   oss << " spec='" << future_spec_ << "'";
   return oss.str();
 }
 
-bool TimeZoneInfo::NextTransition(time_point<sys_seconds>* tp) const {
+bool TimeZoneInfo::NextTransition(const time_point<seconds>& tp,
+                                  time_zone::civil_transition* trans) const {
   if (transitions_.empty()) return false;
   const Transition* begin = &transitions_[0];
   const Transition* end = begin + transitions_.size();
@@ -905,22 +921,24 @@ bool TimeZoneInfo::NextTransition(time_point<sys_seconds>* tp) const {
     // really a sentinel, not a transition.  See tz/zic.c.
     ++begin;
   }
-  std::int_fast64_t unix_time = ToUnixSeconds(*tp);
+  std::int_fast64_t unix_time = ToUnixSeconds(tp);
   const Transition target = { unix_time };
   const Transition* tr = std::upper_bound(begin, end, target,
                                           Transition::ByUnixTime());
-  if (tr != begin) {  // skip no-op transitions
-    for (; tr != end; ++tr) {
-      if (!EquivTransitions(tr[-1].type_index, tr[0].type_index)) break;
-    }
+  for (; tr != end; ++tr) {  // skip no-op transitions
+    std::uint_fast8_t prev_type_index =
+        (tr == begin) ? default_transition_type_ : tr[-1].type_index;
+    if (!EquivTransitions(prev_type_index, tr[0].type_index)) break;
   }
   // When tr == end we return false, ignoring future_spec_.
   if (tr == end) return false;
-  *tp = FromUnixSeconds(tr->unix_time);
+  trans->from = tr->prev_civil_sec + 1;
+  trans->to = tr->civil_sec;
   return true;
 }
 
-bool TimeZoneInfo::PrevTransition(time_point<sys_seconds>* tp) const {
+bool TimeZoneInfo::PrevTransition(const time_point<seconds>& tp,
+                                  time_zone::civil_transition* trans) const {
   if (transitions_.empty()) return false;
   const Transition* begin = &transitions_[0];
   const Transition* end = begin + transitions_.size();
@@ -929,11 +947,12 @@ bool TimeZoneInfo::PrevTransition(time_point<sys_seconds>* tp) const {
     // really a sentinel, not a transition.  See tz/zic.c.
     ++begin;
   }
-  std::int_fast64_t unix_time = ToUnixSeconds(*tp);
-  if (FromUnixSeconds(unix_time) != *tp) {
+  std::int_fast64_t unix_time = ToUnixSeconds(tp);
+  if (FromUnixSeconds(unix_time) != tp) {
     if (unix_time == std::numeric_limits<std::int_fast64_t>::max()) {
       if (end == begin) return false;  // Ignore future_spec_.
-      *tp = FromUnixSeconds((--end)->unix_time);
+      trans->from = (--end)->prev_civil_sec + 1;
+      trans->to = end->civil_sec;
       return true;
     }
     unix_time += 1;  // ceils
@@ -941,18 +960,19 @@ bool TimeZoneInfo::PrevTransition(time_point<sys_seconds>* tp) const {
   const Transition target = { unix_time };
   const Transition* tr = std::lower_bound(begin, end, target,
                                           Transition::ByUnixTime());
-  if (tr != begin) {  // skip no-op transitions
-    for (; tr - 1 != begin; --tr) {
-      if (!EquivTransitions(tr[-2].type_index, tr[-1].type_index)) break;
-    }
+  for (; tr != begin; --tr) {  // skip no-op transitions
+    std::uint_fast8_t prev_type_index =
+        (tr - 1 == begin) ? default_transition_type_ : tr[-2].type_index;
+    if (!EquivTransitions(prev_type_index, tr[-1].type_index)) break;
   }
   // When tr == end we return the "last" transition, ignoring future_spec_.
   if (tr == begin) return false;
-  *tp = FromUnixSeconds((--tr)->unix_time);
+  trans->from = (--tr)->prev_civil_sec + 1;
+  trans->to = tr->civil_sec;
   return true;
 }
 
 }  // namespace cctz
 }  // namespace time_internal
-}  // inline namespace lts_2018_06_20
+}  // inline namespace lts_2018_12_18
 }  // namespace absl