- normalize (tm_sec, 0, 59, tm_min);
- normalize (tm_min, 0, 59, tm_hour);
- normalize (tm_hour, 0, 24, tm_mday);
-
- /* Normalize the month first so we can use
- it to figure the range for the day. */
- normalize (tm_mon, 0, 11, tm_year);
- normalize (tm_mday, 1, __mon_lengths[__isleap (tp->tm_year)][tp->tm_mon],
- tm_mon);
-
- /* Normalize the month again, since normalizing
- the day may have pushed it out of range. */
- normalize (tm_mon, 0, 11, tm_year);
-
- /* Normalize the day again, because normalizing
- the month may have changed the range. */
- normalize (tm_mday, 1, __mon_lengths[__isleap (tp->tm_year)][tp->tm_mon],
- tm_mon);
-
- /* Check for out-of-range values. */
-#define lowhigh(field, minmax, cmp) (tp->field cmp minmax.field)
-#define low(field) lowhigh(field, min, <)
-#define high(field) lowhigh(field, max, >)
-#define oor(field) (low(field) || high(field))
-#define lowbound(field) (tp->field == min.field)
-#define highbound(field) (tp->field == max.field)
- if (oor(tm_year))
- invalid();
- else if (lowbound(tm_year))
+ return r;
+}
+
+
+/* Convert *TP to a time_t value, inverting
+ the monotonic and mostly-unit-linear conversion function CONVERT.
+ Use *OFFSET to keep track of a guess at the offset of the result,
+ compared to what the result would be for UTC without leap seconds.
+ If *OFFSET's guess is correct, only one CONVERT call is needed. */
+time_t
+__mktime_internal (struct tm *tp,
+ struct tm *(*convert) (const time_t *, struct tm *),
+ time_t *offset)
+{
+ time_t t, dt, t0, t1, t2;
+ struct tm tm;
+
+ /* The maximum number of probes (calls to CONVERT) should be enough
+ to handle any combinations of time zone rule changes, solar time,
+ leap seconds, and oscillations around a spring-forward gap.
+ POSIX.1 prohibits leap seconds, but some hosts have them anyway. */
+ int remaining_probes = 6;
+
+ /* Time requested. Copy it in case CONVERT modifies *TP; this can
+ occur if TP is localtime's returned value and CONVERT is localtime. */
+ 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_requested = tp->tm_year;
+ int isdst = tp->tm_isdst;
+
+ /* Ensure that mon is in range, and set year accordingly. */
+ int mon_remainder = mon % 12;
+ int negative_mon_remainder = mon_remainder < 0;
+ int mon_years = mon / 12 - negative_mon_remainder;
+ int year = year_requested + mon_years;
+
+ /* The other values need not be in range:
+ the remaining code handles minor overflows correctly,
+ assuming int and time_t arithmetic wraps around.
+ Major overflows are caught at the end. */
+
+ /* Calculate day of year from year, month, and day of month.
+ The result need not be in range. */
+ int yday = ((__mon_yday[__isleap (year + TM_YEAR_BASE)]
+ [mon_remainder + 12 * negative_mon_remainder])
+ + mday - 1);
+
+ int sec_requested = sec;
+#if LEAP_SECONDS_POSSIBLE
+ /* Handle out-of-range seconds specially,
+ since ydhms_tm_diff assumes every minute has 60 seconds. */
+ if (sec < 0)
+ sec = 0;
+ if (59 < sec)
+ sec = 59;
+#endif
+
+ /* Invert CONVERT by probing. First assume the same offset as last time.
+ Then repeatedly use the error to improve the guess. */
+
+ tm.tm_year = EPOCH_YEAR - TM_YEAR_BASE;
+ tm.tm_yday = tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
+ t0 = ydhms_tm_diff (year, yday, hour, min, sec, &tm);
+
+ for (t = t1 = t2 = t0 + *offset;
+ (dt = ydhms_tm_diff (year, yday, hour, min, sec,
+ ranged_convert (convert, &t, &tm)));
+ t1 = t2, t2 = t, t += dt)
+ if (t == t1 && t != t2
+ && (isdst < 0 || tm.tm_isdst < 0
+ || (isdst != 0) != (tm.tm_isdst != 0)))
+ /* We can't possibly find a match, as we are oscillating
+ between two values. The requested time probably falls
+ within a spring-forward gap of size DT. Follow the common
+ practice in this case, which is to return a time that is DT
+ away from the requested time, preferring a time whose
+ tm_isdst differs from the requested value. In practice,
+ this is more useful than returning -1. */
+ break;
+ else if (--remaining_probes == 0)
+ return -1;
+
+ /* If we have a match, check whether tm.tm_isdst has the requested
+ value, if any. */
+ if (dt == 0 && isdst != tm.tm_isdst && 0 <= isdst && 0 <= tm.tm_isdst)