Import of CCTZ from GitHub.

PiperOrigin-RevId: 539104398
Change-Id: I6385662e0c5694d40c57887f983b16adc9eced14

absl/time/internal/cctz/src/time_zone_format.cc

@@ -13,8 +13,10 @@
 //   limitations under the License.
 
 #if !defined(HAS_STRPTIME)
-#if !defined(_MSC_VER) && !defined(__MINGW32__)
-#define HAS_STRPTIME 1  // assume everyone has strptime() except windows
+#if !defined(_MSC_VER) && !defined(__MINGW32__) && !defined(__VXWORKS__)
+#define HAS_STRPTIME \
+  1  // assume everyone has strptime() except windows
+     // and VxWorks
 #endif
 #endif
 

absl/time/internal/cctz/src/time_zone_libc.cc

@@ -71,6 +71,16 @@ auto tm_zone(const std::tm& tm) -> decltype(tzname[0]) {
   const bool is_dst = tm.tm_isdst > 0;
   return tzname[is_dst];
 }
+#elif defined(__VXWORKS__)
+// Uses the globals: 'timezone' and 'tzname'.
+auto tm_gmtoff(const std::tm& tm) -> decltype(timezone + 0) {
+  const bool is_dst = tm.tm_isdst > 0;
+  return timezone + (is_dst ? 60 * 60 : 0);
+}
+auto tm_zone(const std::tm& tm) -> decltype(tzname[0]) {
+  const bool is_dst = tm.tm_isdst > 0;
+  return tzname[is_dst];
+}
 #else
 // Adapt to different spellings of the struct std::tm extension fields.
 #if defined(tm_gmtoff)
@@ -108,6 +118,7 @@ auto tm_zone(const T& tm) -> decltype(tm.__tm_zone) {
 }
 #endif  // tm_zone
 #endif
+using tm_gmtoff_t = decltype(tm_gmtoff(std::tm{}));
 
 inline std::tm* gm_time(const std::time_t* timep, std::tm* result) {
 #if defined(_WIN32) || defined(_WIN64)
@@ -154,7 +165,7 @@ bool make_time(const civil_second& cs, int is_dst, std::time_t* t,
 
 // Find the least time_t in [lo:hi] where local time matches offset, given:
 // (1) lo doesn't match, (2) hi does, and (3) there is only one transition.
-std::time_t find_trans(std::time_t lo, std::time_t hi, int offset) {
+std::time_t find_trans(std::time_t lo, std::time_t hi, tm_gmtoff_t offset) {
   std::tm tm;
   while (lo + 1 != hi) {
     const std::time_t mid = lo + (hi - lo) / 2;
@@ -265,7 +276,7 @@ time_zone::civil_lookup TimeZoneLibC::MakeTime(const civil_second& cs) const {
       return {time_zone::civil_lookup::UNIQUE, tp, tp, tp};
     }
 
-    int offset = tm_gmtoff(tm0);
+    tm_gmtoff_t offset = tm_gmtoff(tm0);
     if (t0 < t1) {  // negative DST
       std::swap(t0, t1);
       offset = tm_gmtoff(tm1);