Use a custom mktime() function to avoid platform dependencies.upb_mktime

1 files changed, 43 insertions, 1 deletions

diff --git a/upb/json/parser.rl b/upb/json/parser.rl
index 7e260a4..fd3704c 100644
--- a/upb/json/parser.rl
+++ b/upb/json/parser.rl
@@ -1684,6 +1684,48 @@ static void start_timestamp_zone(upb_json_parser *p, const char *ptr) {
   capture_begin(p, ptr);
 }
 
+#define EPOCH_YEAR 1970
+#define TM_YEAR_BASE 1900
+
+static bool isleap(int year) {
+  return (year % 4) == 0 && (year % 100 != 0 || (year % 400) == 0);
+}
+
+const unsigned short int __mon_yday[2][13] = {
+    /* Normal years.  */
+    { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
+    /* Leap years.  */
+    { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
+};
+
+int64_t epoch(int year, int yday, int hour, int min, int sec) {
+  int64_t years = year - EPOCH_YEAR;
+
+  int64_t leap_days = years / 4 - years / 100 + years / 400;
+
+  int64_t days = years * 365 + yday + leap_days;
+  int64_t hours = days * 24 + hour;
+  int64_t mins = hours * 60 + min;
+  int64_t secs = mins * 60 + sec;
+  return secs;
+}
+
+
+static int64_t upb_mktime(const struct tm *tp) {
+  int sec = tp->tm_sec;
+  int min = tp->tm_min;
+  int hour = tp->tm_hour;
+  int mday = tp->tm_mday;
+  int mon = tp->tm_mon;
+  int year = tp->tm_year + TM_YEAR_BASE;
+
+  /* Calculate day of year from year, month, and day of month. */
+  int mon_yday = ((__mon_yday[isleap(year)][mon]) - 1);
+  int yday = mon_yday + mday;
+
+  return epoch(year, yday, hour, min, sec);
+}
+
 static bool end_timestamp_zone(upb_json_parser *p, const char *ptr) {
   size_t len;
   const char *buf;
@@ -1711,7 +1753,7 @@ static bool end_timestamp_zone(upb_json_parser *p, const char *ptr) {
   }
 
   /* Normalize tm */
-  seconds = mktime(&p->tm);
+  seconds = upb_mktime(&p->tm);
 
   /* Check timestamp boundary */
   if (seconds < -62135596800) {