@@ -61,6 +61,15 @@ extern time_t __mktime_internal (struct tm *__tp,
struct tm *(*__func) (const time_t *,
struct tm *),
time_t *__offset) attribute_hidden;
+
+/* Subroutine of `__mktime64'. Return the `__time64_t' representation of TP and
+ normalize TP, given that a `struct tm *' maps to a `__time64_t' as performed
+ by FUNC. Keep track of next guess for __time64_t offset in *OFFSET. */
+extern __time64_t __mktime64_internal (struct tm *__tp,
+ struct tm *(*__func) (const __time64_t *,
+ struct tm *),
+ __time64_t *__offset) attribute_hidden;
+
extern struct tm *__localtime_r (const time_t *__timer,
struct tm *__tp) attribute_hidden;
@@ -70,5 +70,6 @@ libc {
__ctime64; __ctime64_r;
__gmtime64; __gmtime64_r;
__localtime64; __localtime64_r;
+ __mktime64; __timelocal64_r;
}
}
@@ -599,6 +599,409 @@ weak_alias (mktime, timelocal)
libc_hidden_def (mktime)
libc_hidden_weak (timelocal)
#endif
+
+/* Return an integer value measuring (YEAR1-YDAY1 HOUR1:MIN1:SEC1) -
+ (YEAR0-YDAY0 HOUR0:MIN0:SEC0) in seconds, assuming that the clocks
+ were not adjusted between the time stamps.
+
+ The YEAR values uses the same numbering as TP->tm_year. Values
+ need not be in the usual range. However, YEAR1 must not be less
+ than 2 * INT_MIN or greater than 2 * INT_MAX.
+
+ The result may overflow. It is the caller's responsibility to
+ detect overflow. */
+
+static __time64_t
+ydhms64_diff (long_int year1, long_int yday1, int hour1, int min1, int sec1,
+ int year0, int yday0, int hour0, int min0, int sec0)
+{
+ verify (C99_integer_division, -1 / 2 == 0);
+
+ /* Compute intervening leap days correctly even if year is negative.
+ Take care to avoid integer overflow here. */
+ int a4 = SHR (year1, 2) + SHR (TM_YEAR_BASE, 2) - ! (year1 & 3);
+ int b4 = SHR (year0, 2) + SHR (TM_YEAR_BASE, 2) - ! (year0 & 3);
+ int a100 = a4 / 25 - (a4 % 25 < 0);
+ int b100 = b4 / 25 - (b4 % 25 < 0);
+ int a400 = SHR (a100, 2);
+ int b400 = SHR (b100, 2);
+ int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
+
+ /* Compute the desired time in __time64_t precision. Overflow might
+ occur here. */
+ __time64_t tyear1 = year1;
+ __time64_t years = tyear1 - year0;
+ __time64_t days = 365 * years + yday1 - yday0 + intervening_leap_days;
+ __time64_t hours = 24 * days + hour1 - hour0;
+ __time64_t minutes = 60 * hours + min1 - min0;
+ __time64_t seconds = 60 * minutes + sec1 - sec0;
+ return seconds;
+}
+
+/* Return the average of A and B, even if A + B would overflow. */
+static __time64_t
+time64_t_avg (__time64_t a, __time64_t b)
+{
+ return SHR (a, 1) + SHR (b, 1) + (a & b & 1);
+}
+
+/* Return 1 if A + B does not overflow. If __time64_t is unsigned and if
+ B's top bit is set, assume that the sum represents A - -B, and
+ return 1 if the subtraction does not wrap around. */
+static int
+time64_t_add_ok (__time64_t a, __time64_t b)
+{
+ if (! TYPE_SIGNED (__time64_t))
+ {
+ __time64_t sum = a + b;
+ return (sum < a) == (TIME_T_MIDPOINT <= b);
+ }
+ else if (WRAPV)
+ {
+ __time64_t sum = a + b;
+ return (sum < a) == (b < 0);
+ }
+ else
+ {
+ __time64_t avg = time64_t_avg (a, b);
+ return TIME_T_MIN / 2 <= avg && avg <= TIME_T_MAX / 2;
+ }
+}
+
+/* Return 1 if A + B does not overflow. */
+static int
+time64_t_int_add_ok (__time64_t a, int b)
+{
+ verify (int_no_wider_than_time64_t, INT_MAX <= TIME_T_MAX);
+ if (WRAPV)
+ {
+ __time64_t sum = a + b;
+ return (sum < a) == (b < 0);
+ }
+ else
+ {
+ int a_odd = a & 1;
+ __time64_t avg = SHR (a, 1) + (SHR (b, 1) + (a_odd & b));
+ return TIME_T_MIN / 2 <= avg && avg <= TIME_T_MAX / 2;
+ }
+}
+
+/* Return a __time64_t value corresponding to (YEAR-YDAY HOUR:MIN:SEC),
+ assuming that *T corresponds to *TP and that no clock adjustments
+ occurred between *TP and the desired time.
+ If TP is null, return a value not equal to *T; this avoids false matches.
+ If overflow occurs, yield the minimal or maximal value, except do not
+ yield a value equal to *T. */
+static __time64_t
+guess_time64_tm (long_int year, long_int yday, int hour, int min, int sec,
+ const __time64_t *t, const struct tm *tp)
+{
+ if (tp)
+ {
+ __time64_t d = ydhms64_diff (year, yday, hour, min, sec,
+ tp->tm_year, tp->tm_yday,
+ tp->tm_hour, tp->tm_min, tp->tm_sec);
+ if (time64_t_add_ok (*t, d))
+ return *t + d;
+ }
+
+ /* Overflow occurred one way or another. Return the nearest result
+ that is actually in range, except don't report a zero difference
+ if the actual difference is nonzero, as that would cause a false
+ match; and don't oscillate between two values, as that would
+ confuse the spring-forward gap detector. */
+ return (*t < TIME_T_MIDPOINT
+ ? (*t <= TIME_T_MIN + 1 ? *t + 1 : TIME_T_MIN)
+ : (TIME_T_MAX - 1 <= *t ? *t - 1 : TIME_T_MAX));
+}
+
+/* Use CONVERT to convert *T to a broken down time in *TP.
+ If *T is out of range for conversion, adjust it so that
+ it is the nearest in-range value and then convert that. */
+static struct tm *
+ranged64_convert (struct tm *(*convert) (const __time64_t *, struct tm *),
+ __time64_t *t, struct tm *tp)
+{
+ struct tm *r = convert (t, tp);
+
+ if (!r && *t)
+ {
+ __time64_t bad = *t;
+ __time64_t ok = 0;
+
+ /* BAD is a known unconvertible __time64_t, and OK is a known good one.
+ Use binary search to narrow the range between BAD and OK until
+ they differ by 1. */
+ while (bad != ok + (bad < 0 ? -1 : 1))
+ {
+ __time64_t mid = *t = time64_t_avg (ok, bad);
+ r = convert (t, tp);
+ if (r)
+ ok = mid;
+ else
+ bad = mid;
+ }
+
+ if (!r && ok)
+ {
+ /* The last conversion attempt failed;
+ revert to the most recent successful attempt. */
+ *t = ok;
+ r = convert (t, tp);
+ }
+ }
+
+ return r;
+}
+
+
+/* Convert *TP to a __time64_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.
+ This function is external because it is used also by timegm.c. */
+__time64_t
+__mktime64_internal (struct tm *tp,
+ struct tm *(*convert) (const __time64_t *, struct tm *),
+ __time64_t *offset)
+{
+ __time64_t t, gt, 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;
+
+ /* 1 if the previous probe was DST. */
+ int dst2;
+
+ /* 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;
+ long_int lyear_requested = year_requested;
+ long_int year = lyear_requested + mon_years;
+
+ /* The other values need not be in range:
+ the remaining code handles minor overflows correctly,
+ assuming int and __time64_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 mon_yday = ((__mon_yday[leapyear (year)]
+ [mon_remainder + 12 * negative_mon_remainder])
+ - 1);
+ long_int lmday = mday;
+ long_int yday = mon_yday + lmday;
+
+ __time64_t guessed_offset = *offset;
+
+ 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;
+ }
+
+ /* Invert CONVERT by probing. First assume the same offset as last
+ time. */
+
+ t0 = ydhms64_diff (year, yday, hour, min, sec,
+ EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0, - guessed_offset);
+
+ if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3)
+ {
+ /* __time64_t isn't large enough to rule out overflows, so check
+ for major overflows. A gross check suffices, since if t0
+ has overflowed, it is off by a multiple of TIME_T_MAX -
+ TIME_T_MIN + 1. So ignore any component of the difference
+ that is bounded by a small value. */
+
+ /* Approximate log base 2 of the number of time units per
+ biennium. A biennium is 2 years; use this unit instead of
+ years to avoid integer overflow. For example, 2 average
+ Gregorian years are 2 * 365.2425 * 24 * 60 * 60 seconds,
+ which is 63113904 seconds, and rint (log2 (63113904)) is
+ 26. */
+ int ALOG2_SECONDS_PER_BIENNIUM = 26;
+ int ALOG2_MINUTES_PER_BIENNIUM = 20;
+ int ALOG2_HOURS_PER_BIENNIUM = 14;
+ int ALOG2_DAYS_PER_BIENNIUM = 10;
+ int LOG2_YEARS_PER_BIENNIUM = 1;
+
+ int approx_requested_biennia =
+ (SHR (year_requested, LOG2_YEARS_PER_BIENNIUM)
+ - SHR (EPOCH_YEAR - TM_YEAR_BASE, LOG2_YEARS_PER_BIENNIUM)
+ + SHR (mday, ALOG2_DAYS_PER_BIENNIUM)
+ + SHR (hour, ALOG2_HOURS_PER_BIENNIUM)
+ + SHR (min, ALOG2_MINUTES_PER_BIENNIUM)
+ + (LEAP_SECONDS_POSSIBLE
+ ? 0
+ : SHR (sec, ALOG2_SECONDS_PER_BIENNIUM)));
+
+ int approx_biennia = SHR (t0, ALOG2_SECONDS_PER_BIENNIUM);
+ int diff = approx_biennia - approx_requested_biennia;
+ int approx_abs_diff = diff < 0 ? -1 - diff : diff;
+
+ /* IRIX 4.0.5 cc miscalculates TIME_T_MIN / 3: it erroneously
+ gives a positive value of 715827882. Setting a variable
+ first then doing math on it seems to work.
+ (ghazi@caip.rutgers.edu) */
+ __time64_t time64_t_max = TIME_T_MAX;
+ __time64_t time64_t_min = TIME_T_MIN;
+ __time64_t overflow_threshold =
+ (time64_t_max / 3 - time64_t_min / 3) >> ALOG2_SECONDS_PER_BIENNIUM;
+
+ if (overflow_threshold < approx_abs_diff)
+ {
+ /* Overflow occurred. Try repairing it; this might work if
+ the time zone offset is enough to undo the overflow. */
+ __time64_t repaired_t0 = -1 - t0;
+ approx_biennia = SHR (repaired_t0, ALOG2_SECONDS_PER_BIENNIUM);
+ diff = approx_biennia - approx_requested_biennia;
+ approx_abs_diff = diff < 0 ? -1 - diff : diff;
+ if (overflow_threshold < approx_abs_diff)
+ return -1;
+ guessed_offset += repaired_t0 - t0;
+ t0 = repaired_t0;
+ }
+ }
+
+ /* Repeatedly use the error to improve the guess. */
+
+ for (t = t1 = t2 = t0, dst2 = 0;
+ (gt = guess_time64_tm (year, yday, hour, min, sec, &t,
+ ranged64_convert (convert, &t, &tm)),
+ t != gt);
+ t1 = t2, t2 = t, t = gt, dst2 = tm.tm_isdst != 0)
+ if (t == t1 && t != t2
+ && (tm.tm_isdst < 0
+ || (isdst < 0
+ ? dst2 <= (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 GT - T. Follow the common
+ practice in this case, which is to return a time that is GT - T
+ away from the requested time, preferring a time whose
+ tm_isdst differs from the requested value. (If no tm_isdst
+ was requested and only one of the two values has a nonzero
+ tm_isdst, prefer that value.) In practice, this is more
+ useful than returning -1. */
+ goto offset_found;
+ else if (--remaining_probes == 0)
+ return -1;
+
+ /* We have a match. Check whether tm.tm_isdst has the requested
+ value, if any. */
+ if (isdst_differ (isdst, tm.tm_isdst))
+ {
+ /* tm.tm_isdst has the wrong value. Look for a neighboring
+ time with the right value, and use its UTC offset.
+
+ Heuristic: probe the adjacent timestamps in both directions,
+ looking for the desired isdst. This should work for all real
+ time zone histories in the tz database. */
+
+ /* Distance between probes when looking for a DST boundary. In
+ tzdata2003a, the shortest period of DST is 601200 seconds
+ (e.g., America/Recife starting 2000-10-08 01:00), and the
+ shortest period of non-DST surrounded by DST is 694800
+ seconds (Africa/Tunis starting 1943-04-17 01:00). Use the
+ minimum of these two values, so we don't miss these short
+ periods when probing. */
+ int stride = 601200;
+
+ /* The longest period of DST in tzdata2003a is 536454000 seconds
+ (e.g., America/Jujuy starting 1946-10-01 01:00). The longest
+ period of non-DST is much longer, but it makes no real sense
+ to search for more than a year of non-DST, so use the DST
+ max. */
+ int duration_max = 536454000;
+
+ /* Search in both directions, so the maximum distance is half
+ the duration; add the stride to avoid off-by-1 problems. */
+ int delta_bound = duration_max / 2 + stride;
+
+ int delta, direction;
+
+ for (delta = stride; delta < delta_bound; delta += stride)
+ for (direction = -1; direction <= 1; direction += 2)
+ if (time64_t_int_add_ok (t, delta * direction))
+ {
+ __time64_t ot = t + delta * direction;
+ struct tm otm;
+ ranged64_convert (convert, &ot, &otm);
+ if (! isdst_differ (isdst, otm.tm_isdst))
+ {
+ /* We found the desired tm_isdst.
+ Extrapolate back to the desired time. */
+ t = guess_time64_tm (year, yday, hour, min, sec, &ot, &otm);
+ ranged64_convert (convert, &t, &tm);
+ goto offset_found;
+ }
+ }
+ }
+
+ offset_found:
+ *offset = guessed_offset + t - t0;
+
+ if (LEAP_SECONDS_POSSIBLE && sec_requested != tm.tm_sec)
+ {
+ /* Adjust time to reflect the tm_sec requested, not the normalized value.
+ Also, repair any damage from a false match due to a leap second. */
+ int sec_adjustment = (sec == 0 && tm.tm_sec == 60) - sec;
+ if (! time64_t_int_add_ok (t, sec_requested))
+ return -1;
+ t1 = t + sec_requested;
+ if (! time64_t_int_add_ok (t1, sec_adjustment))
+ return -1;
+ t2 = t1 + sec_adjustment;
+ if (! convert (&t2, &tm))
+ return -1;
+ t = t2;
+ }
+
+ *tp = tm;
+ return t;
+}
+
+
+/* This uses a signed type wide enough to hold any UTC offset in seconds. */
+static __time64_t localtime64_offset;
+
+/* Convert *TP to a __time64_t value. */
+__time64_t
+__mktime64 (struct tm *tp)
+{
+#ifdef _LIBC
+ /* POSIX.1 8.1.1 requires that whenever mktime() is called, the
+ time zone names contained in the external variable 'tzname' shall
+ be set as if the tzset() function had been called. */
+ __tzset ();
+#endif
+
+ return __mktime64_internal (tp, __localtime64_r, &localtime64_offset);
+}
#if defined DEBUG_MKTIME && DEBUG_MKTIME