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authorEric Andersen <andersen@codepoet.org>2000-10-09 20:06:30 +0000
committerEric Andersen <andersen@codepoet.org>2000-10-09 20:06:30 +0000
commitc1fe19d4c1db610692365472a90f4661e48449c1 (patch)
treed0b0219ffca3c4c4256f55c4aea4513e43d6aecd /libc/misc/time/mktime.c
parent9efafb8bbc7408b04643dcd53825d971577b4d9d (diff)
Bug ugly formatting update
Diffstat (limited to 'libc/misc/time/mktime.c')
-rw-r--r--libc/misc/time/mktime.c314
1 files changed, 155 insertions, 159 deletions
diff --git a/libc/misc/time/mktime.c b/libc/misc/time/mktime.c
index 7f7aabcd7..d6ee2ed42 100644
--- a/libc/misc/time/mktime.c
+++ b/libc/misc/time/mktime.c
@@ -10,7 +10,7 @@
#define LEAP_SECONDS_POSSIBLE 1
#endif
-#include <sys/types.h> /* Some systems define `time_t' here. */
+#include <sys/types.h> /* Some systems define `time_t' here. */
#include <time.h>
#if __STDC__ || __GNU_LIBRARY__ || STDC_HEADERS
@@ -24,15 +24,15 @@
#endif
/* Make it work even if the system's libc has its own mktime routine. */
#define mktime my_mktime
-#endif /* DEBUG */
+#endif /* DEBUG */
#ifndef __P
#if defined (__GNUC__) || (defined (__STDC__) && __STDC__)
#define __P(args) args
#else
#define __P(args) ()
-#endif /* GCC. */
-#endif /* Not __P. */
+#endif /* GCC. */
+#endif /* Not __P. */
#ifndef CHAR_BIT
#define CHAR_BIT 8
@@ -64,47 +64,47 @@
#endif
/* How many days come before each month (0-12). */
-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 }
- };
-
-static time_t ydhms_tm_diff __P ((int, int, int, int, int, const struct tm *));
-time_t __mktime_internal __P ((struct tm *,
- struct tm *(*) (const time_t *, struct tm *),
- time_t *));
+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}
+};
+
+static time_t ydhms_tm_diff
+
+__P((int, int, int, int, int, const struct tm *));
+time_t __mktime_internal
+__P((struct tm *, struct tm * (*)(const time_t *, struct tm *), time_t *));
/* Yield the difference between (YEAR-YDAY HOUR:MIN:SEC) and (*TP),
measured in seconds, ignoring leap seconds.
YEAR uses the same numbering as TM->tm_year.
All values are in range, except possibly YEAR.
If overflow occurs, yield the low order bits of the correct answer. */
-static time_t
-ydhms_tm_diff (year, yday, hour, min, sec, tp)
- int year, yday, hour, min, sec;
- const struct tm *tp;
+static time_t ydhms_tm_diff(year, yday, hour, min, sec, tp)
+int year, yday, hour, min, sec;
+const struct tm *tp;
{
- /* Compute intervening leap days correctly even if year is negative.
- Take care to avoid int overflow. time_t overflow is OK, since
- only the low order bits of the correct time_t answer are needed.
- Don't convert to time_t until after all divisions are done, since
- time_t might be unsigned. */
- int a4 = (year >> 2) + (TM_YEAR_BASE >> 2) - ! (year & 3);
- int b4 = (tp->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (tp->tm_year & 3);
- int a100 = a4 / 25 - (a4 % 25 < 0);
- int b100 = b4 / 25 - (b4 % 25 < 0);
- int a400 = a100 >> 2;
- int b400 = b100 >> 2;
- int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
- time_t years = year - (time_t) tp->tm_year;
- time_t days = (365 * years + intervening_leap_days
- + (yday - tp->tm_yday));
- return (60 * (60 * (24 * days + (hour - tp->tm_hour))
- + (min - tp->tm_min))
- + (sec - tp->tm_sec));
+ /* Compute intervening leap days correctly even if year is negative.
+ Take care to avoid int overflow. time_t overflow is OK, since
+ only the low order bits of the correct time_t answer are needed.
+ Don't convert to time_t until after all divisions are done, since
+ time_t might be unsigned. */
+ int a4 = (year >> 2) + (TM_YEAR_BASE >> 2) - !(year & 3);
+ int b4 = (tp->tm_year >> 2) + (TM_YEAR_BASE >> 2) - !(tp->tm_year & 3);
+ int a100 = a4 / 25 - (a4 % 25 < 0);
+ int b100 = b4 / 25 - (b4 % 25 < 0);
+ int a400 = a100 >> 2;
+ int b400 = b100 >> 2;
+ int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
+ time_t years = year - (time_t) tp->tm_year;
+ time_t days = (365 * years + intervening_leap_days
+
+ + (yday - tp->tm_yday));
+ return (60 * (60 * (24 * days + (hour - tp->tm_hour))
+ + (min - tp->tm_min))
+ + (sec - tp->tm_sec));
}
@@ -112,18 +112,17 @@ static time_t localtime_offset;
/* Convert *TP to a time_t value. */
-time_t
-mktime (tp)
- struct tm *tp;
+time_t mktime(tp)
+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 ();
+ /* 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 __mktime_internal (tp, localtime_r, &localtime_offset);
+ return __mktime_internal(tp, localtime_r, &localtime_offset);
}
/* Convert *TP to a time_t value, inverting
@@ -131,129 +130,126 @@ mktime (tp)
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 (tp, convert, offset)
- struct tm *tp;
- struct tm *(*convert) __P ((const time_t *, struct tm *));
- time_t *offset;
+time_t __mktime_internal(tp, convert, offset)
+struct tm *tp;
+struct tm *(*convert) __P((const time_t *, struct tm *));
+time_t *offset;
{
- time_t t, dt, t0;
- 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,
- and leap seconds. Posix.1 prohibits leap seconds, but some hosts
- have them anyway. */
- int remaining_probes = 4;
-
- /* 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);
+ time_t t, dt, t0;
+ 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,
+ and leap seconds. Posix.1 prohibits leap seconds, but some hosts
+ have them anyway. */
+ int remaining_probes = 4;
+
+ /* 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);
#if LEAP_SECONDS_POSSIBLE
- /* Handle out-of-range seconds specially,
- since ydhms_tm_diff assumes every minute has 60 seconds. */
- int sec_requested = sec;
- if (sec < 0)
- sec = 0;
- if (59 < sec)
- sec = 59;
+ /* Handle out-of-range seconds specially,
+ since ydhms_tm_diff assumes every minute has 60 seconds. */
+ int sec_requested = sec;
+
+ 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 = t0 + *offset;
- (dt = ydhms_tm_diff (year, yday, hour, min, sec, (*convert) (&t, &tm)));
- t += dt)
- if (--remaining_probes == 0)
- return -1;
-
- /* Check whether tm.tm_isdst has the requested value, if any. */
- if (0 <= isdst && 0 <= tm.tm_isdst)
- {
- int dst_diff = (isdst != 0) - (tm.tm_isdst != 0);
- if (dst_diff)
- {
- /* Move two hours in the direction indicated by the disagreement,
- probe some more, and switch to a new time if found.
- The largest known fallback due to daylight savings is two hours:
- once, in Newfoundland, 1988-10-30 02:00 -> 00:00. */
- time_t ot = t - 2 * 60 * 60 * dst_diff;
- while (--remaining_probes != 0)
- {
- struct tm otm;
- if (! (dt = ydhms_tm_diff (year, yday, hour, min, sec,
- (*convert) (&ot, &otm))))
- {
- t = ot;
- tm = otm;
- break;
- }
- if ((ot += dt) == t)
- break; /* Avoid a redundant probe. */
- }
- }
- }
-
- *offset = t - t0;
+ /* 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 = t0 + *offset;
+ (dt =
+ ydhms_tm_diff(year, yday, hour, min, sec, (*convert) (&t, &tm)));
+ t += dt)
+ if (--remaining_probes == 0)
+ return -1;
+
+ /* Check whether tm.tm_isdst has the requested value, if any. */
+ if (0 <= isdst && 0 <= tm.tm_isdst) {
+ int dst_diff = (isdst != 0) - (tm.tm_isdst != 0);
+
+ if (dst_diff) {
+ /* Move two hours in the direction indicated by the disagreement,
+ probe some more, and switch to a new time if found.
+ The largest known fallback due to daylight savings is two hours:
+ once, in Newfoundland, 1988-10-30 02:00 -> 00:00. */
+ time_t ot = t - 2 * 60 * 60 * dst_diff;
+
+ while (--remaining_probes != 0) {
+ struct tm otm;
+
+ if (!(dt = ydhms_tm_diff(year, yday, hour, min, sec,
+ (*convert) (&ot, &otm)))) {
+ t = ot;
+ tm = otm;
+ break;
+ }
+ if ((ot += dt) == t)
+ break; /* Avoid a redundant probe. */
+ }
+ }
+ }
+
+ *offset = t - t0;
#if LEAP_SECONDS_POSSIBLE
- if (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. */
- t += sec_requested - sec + (sec == 0 && tm.tm_sec == 60);
- (*convert) (&t, &tm);
- }
+ if (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. */
+ t += sec_requested - sec + (sec == 0 && tm.tm_sec == 60);
+ (*convert) (&t, &tm);
+ }
#endif
#if 0
- if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3)
- {
- /* time_t isn't large enough to rule out overflows in ydhms_tm_diff,
- so check for major overflows. A gross check suffices,
- since if t 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. */
-
- double dyear = (double) year_requested + mon_years - tm.tm_year;
- double dday = 366 * dyear + mday;
- double dsec = 60 * (60 * (24 * dday + hour) + min) + sec_requested;
-
- if (TIME_T_MAX / 3 - TIME_T_MIN / 3 < (dsec < 0 ? - dsec : dsec))
- return -1;
- }
+ if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3) {
+ /* time_t isn't large enough to rule out overflows in ydhms_tm_diff,
+ so check for major overflows. A gross check suffices,
+ since if t 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. */
+
+ double dyear = (double) year_requested + mon_years - tm.tm_year;
+ double dday = 366 * dyear + mday;
+ double dsec = 60 * (60 * (24 * dday + hour) + min) + sec_requested;
+
+ if (TIME_T_MAX / 3 - TIME_T_MIN / 3 < (dsec < 0 ? -dsec : dsec))
+ return -1;
+ }
#endif
- *tp = tm;
- return t;
+ *tp = tm;
+ return t;
}
-