diff options
Diffstat (limited to 'gl/mktime.c')
| -rw-r--r-- | gl/mktime.c | 378 |
1 files changed, 191 insertions, 187 deletions
diff --git a/gl/mktime.c b/gl/mktime.c index 0f30d43f..b0324b82 100644 --- a/gl/mktime.c +++ b/gl/mktime.c @@ -1,5 +1,5 @@ /* Convert a `struct tm' to a time_t value. - Copyright (C) 1993-1999, 2002-2005, 2006, 2007 Free Software Foundation, Inc. + Copyright (C) 1993-1999, 2002-2007, 2009-2010 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Paul Eggert <eggert@twinsun.com>. @@ -36,7 +36,7 @@ #include <limits.h> -#include <string.h> /* For the real memcpy prototype. */ +#include <string.h> /* For the real memcpy prototype. */ #if DEBUG # include <stdio.h> @@ -55,9 +55,9 @@ implementations (e.g., UNICOS 9.0 on a Cray Y-MP EL) don't shift right in the usual way when A < 0, so SHR falls back on division if ordinary A >> B doesn't seem to be the usual signed shift. */ -#define SHR(a, b) \ - (-1 >> 1 == -1 \ - ? (a) >> (b) \ +#define SHR(a, b) \ + (-1 >> 1 == -1 \ + ? (a) >> (b) \ : (a) / (1 << (b)) - ((a) % (1 << (b)) < 0)) /* The extra casts in the following macros work around compiler bugs, @@ -84,14 +84,14 @@ your host. */ #define TYPE_MINIMUM(t) \ ((t) (! TYPE_SIGNED (t) \ - ? (t) 0 \ - : TYPE_SIGNED_MAGNITUDE (t) \ - ? ~ (t) 0 \ - : ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))) + ? (t) 0 \ + : TYPE_SIGNED_MAGNITUDE (t) \ + ? ~ (t) 0 \ + : ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1))) #define TYPE_MAXIMUM(t) \ ((t) (! TYPE_SIGNED (t) \ - ? (t) -1 \ - : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))) + ? (t) -1 \ + : ~ (~ (t) 0 << (sizeof (t) * CHAR_BIT - 1)))) #ifndef TIME_T_MIN # define TIME_T_MIN TYPE_MINIMUM (time_t) @@ -123,7 +123,7 @@ leapyear (long int year) return ((year & 3) == 0 && (year % 100 != 0 - || ((year / 100) & 3) == (- (TM_YEAR_BASE / 100) & 3))); + || ((year / 100) & 3) == (- (TM_YEAR_BASE / 100) & 3))); } /* How many days come before each month (0-12). */ @@ -147,6 +147,7 @@ const unsigned short int __mon_yday[2][13] = # undef __localtime_r # define __localtime_r localtime_r # define __mktime_internal mktime_internal +# include "mktime-internal.h" #endif /* Return an integer value measuring (YEAR1-YDAY1 HOUR1:MIN1:SEC1) - @@ -162,11 +163,14 @@ const unsigned short int __mon_yday[2][13] = static inline time_t ydhms_diff (long int year1, long int yday1, int hour1, int min1, int sec1, - int year0, int yday0, int hour0, int min0, int sec0) + int year0, int yday0, int hour0, int min0, int sec0) { verify (C99_integer_division, -1 / 2 == 0); +#if 0 /* This assertion fails on 32-bit systems with 64-bit time_t, such as + NetBSD 5 on i386. */ verify (long_int_year_and_yday_are_wide_enough, - INT_MAX <= LONG_MAX / 2 || TIME_T_MAX <= UINT_MAX); + INT_MAX <= LONG_MAX / 2 || TIME_T_MAX <= UINT_MAX); +#endif /* Compute intervening leap days correctly even if year is negative. Take care to avoid integer overflow here. */ @@ -198,16 +202,16 @@ ydhms_diff (long int year1, long int yday1, int hour1, int min1, int sec1, yield a value equal to *T. */ static time_t guess_time_tm (long int year, long int yday, int hour, int min, int sec, - const time_t *t, const struct tm *tp) + const time_t *t, const struct tm *tp) { if (tp) { time_t d = ydhms_diff (year, yday, hour, min, sec, - tp->tm_year, tp->tm_yday, - tp->tm_hour, tp->tm_min, tp->tm_sec); + tp->tm_year, tp->tm_yday, + tp->tm_hour, tp->tm_min, tp->tm_sec); time_t t1 = *t + d; if ((t1 < *t) == (TYPE_SIGNED (time_t) ? d < 0 : TIME_T_MAX / 2 < d)) - return t1; + return t1; } /* Overflow occurred one way or another. Return the nearest result @@ -216,8 +220,8 @@ guess_time_tm (long int year, long int yday, int hour, int min, int sec, 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)); + ? (*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. @@ -225,7 +229,7 @@ guess_time_tm (long int year, long int yday, int hour, int min, int sec, it is the nearest in-range value and then convert that. */ static struct tm * ranged_convert (struct tm *(*convert) (const time_t *, struct tm *), - time_t *t, struct tm *tp) + time_t *t, struct tm *tp) { struct tm *r = convert (t, tp); @@ -235,27 +239,27 @@ ranged_convert (struct tm *(*convert) (const time_t *, struct tm *), time_t ok = 0; /* BAD is a known unconvertible time_t, and OK is a known good one. - Use binary search to narrow the range between BAD and OK until - they differ by 1. */ + Use binary search to narrow the range between BAD and OK until + they differ by 1. */ while (bad != ok + (bad < 0 ? -1 : 1)) - { - time_t mid = *t = (bad < 0 - ? bad + ((ok - bad) >> 1) - : ok + ((bad - ok) >> 1)); - r = convert (t, tp); - if (r) - ok = mid; - else - bad = mid; - } + { + time_t mid = *t = (bad < 0 + ? bad + ((ok - bad) >> 1) + : ok + ((bad - ok) >> 1)); + 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); - } + { + /* The last conversion attempt failed; + revert to the most recent successful attempt. */ + *t = ok; + r = convert (t, tp); + } } return r; @@ -270,8 +274,8 @@ ranged_convert (struct tm *(*convert) (const time_t *, struct tm *), This function is external because it is used also by timegm.c. */ time_t __mktime_internal (struct tm *tp, - struct tm *(*convert) (const time_t *, struct tm *), - time_t *offset) + struct tm *(*convert) (const time_t *, struct tm *), + time_t *offset) { time_t t, gt, t0, t1, t2; struct tm tm; @@ -292,7 +296,7 @@ __mktime_internal (struct tm *tp, int year_requested = tp->tm_year; /* Normalize the value. */ int isdst = ((tp->tm_isdst >> (8 * sizeof (tp->tm_isdst) - 1)) - | (tp->tm_isdst != 0)); + | (tp->tm_isdst != 0)); /* 1 if the previous probe was DST. */ int dst2; @@ -312,8 +316,8 @@ __mktime_internal (struct tm *tp, /* 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); + [mon_remainder + 12 * negative_mon_remainder]) + - 1); long int lmday = mday; long int yday = mon_yday + lmday; @@ -324,33 +328,33 @@ __mktime_internal (struct tm *tp, if (LEAP_SECONDS_POSSIBLE) { /* Handle out-of-range seconds specially, - since ydhms_tm_diff assumes every minute has 60 seconds. */ + since ydhms_tm_diff assumes every minute has 60 seconds. */ if (sec < 0) - sec = 0; + sec = 0; if (59 < sec) - sec = 59; + sec = 59; } /* Invert CONVERT by probing. First assume the same offset as last time. */ t0 = ydhms_diff (year, yday, hour, min, sec, - EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0, - guessed_offset); + EPOCH_YEAR - TM_YEAR_BASE, 0, 0, 0, - guessed_offset); if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3) { /* time_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. */ + 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. */ + 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; @@ -358,64 +362,64 @@ __mktime_internal (struct tm *tp, 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))); + (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 abs_diff = diff < 0 ? - diff : diff; /* IRIX 4.0.5 cc miscaculates 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) */ + gives a positive value of 715827882. Setting a variable + first then doing math on it seems to work. + (ghazi@caip.rutgers.edu) */ time_t time_t_max = TIME_T_MAX; time_t time_t_min = TIME_T_MIN; time_t overflow_threshold = - (time_t_max / 3 - time_t_min / 3) >> ALOG2_SECONDS_PER_BIENNIUM; + (time_t_max / 3 - time_t_min / 3) >> ALOG2_SECONDS_PER_BIENNIUM; if (overflow_threshold < abs_diff) - { - /* Overflow occurred. Try repairing it; this might work if - the time zone offset is enough to undo the overflow. */ - time_t repaired_t0 = -1 - t0; - approx_biennia = SHR (repaired_t0, ALOG2_SECONDS_PER_BIENNIUM); - diff = approx_biennia - approx_requested_biennia; - abs_diff = diff < 0 ? - diff : diff; - if (overflow_threshold < abs_diff) - return -1; - guessed_offset += repaired_t0 - t0; - t0 = repaired_t0; - } + { + /* Overflow occurred. Try repairing it; this might work if + the time zone offset is enough to undo the overflow. */ + time_t repaired_t0 = -1 - t0; + approx_biennia = SHR (repaired_t0, ALOG2_SECONDS_PER_BIENNIUM); + diff = approx_biennia - approx_requested_biennia; + abs_diff = diff < 0 ? - diff : diff; + if (overflow_threshold < 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_time_tm (year, yday, hour, min, sec, &t, - ranged_convert (convert, &t, &tm)), - t != gt); + ranged_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)))) + && (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. */ + 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; @@ -425,52 +429,52 @@ __mktime_internal (struct tm *tp, if (isdst != tm.tm_isdst && 0 <= isdst && 0 <= tm.tm_isdst) { /* tm.tm_isdst has the wrong value. Look for a neighboring - time with the right value, and use its UTC offset. + 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. */ + 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. */ + 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. */ + (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. */ + 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) - { - time_t ot = t + delta * direction; - if ((ot < t) == (direction < 0)) - { - struct tm otm; - ranged_convert (convert, &ot, &otm); - if (otm.tm_isdst == isdst) - { - /* We found the desired tm_isdst. - Extrapolate back to the desired time. */ - t = guess_time_tm (year, yday, hour, min, sec, &ot, &otm); - ranged_convert (convert, &t, &tm); - goto offset_found; - } - } - } + for (direction = -1; direction <= 1; direction += 2) + { + time_t ot = t + delta * direction; + if ((ot < t) == (direction < 0)) + { + struct tm otm; + ranged_convert (convert, &ot, &otm); + if (otm.tm_isdst == isdst) + { + /* We found the desired tm_isdst. + Extrapolate back to the desired time. */ + t = guess_time_tm (year, yday, hour, min, sec, &ot, &otm); + ranged_convert (convert, &t, &tm); + goto offset_found; + } + } + } } offset_found: @@ -479,14 +483,14 @@ __mktime_internal (struct tm *tp, 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. */ + Also, repair any damage from a false match due to a leap second. */ int sec_adjustment = (sec == 0 && tm.tm_sec == 60) - sec; t1 = t + sec_requested; t2 = t1 + sec_adjustment; if (((t1 < t) != (sec_requested < 0)) - | ((t2 < t1) != (sec_adjustment < 0)) - | ! convert (&t2, &tm)) - return -1; + | ((t2 < t1) != (sec_adjustment < 0)) + | ! convert (&t2, &tm)) + return -1; t = t2; } @@ -530,13 +534,13 @@ static int not_equal_tm (const struct tm *a, const struct tm *b) { return ((a->tm_sec ^ b->tm_sec) - | (a->tm_min ^ b->tm_min) - | (a->tm_hour ^ b->tm_hour) - | (a->tm_mday ^ b->tm_mday) - | (a->tm_mon ^ b->tm_mon) - | (a->tm_year ^ b->tm_year) - | (a->tm_yday ^ b->tm_yday) - | (a->tm_isdst ^ b->tm_isdst)); + | (a->tm_min ^ b->tm_min) + | (a->tm_hour ^ b->tm_hour) + | (a->tm_mday ^ b->tm_mday) + | (a->tm_mon ^ b->tm_mon) + | (a->tm_year ^ b->tm_year) + | (a->tm_yday ^ b->tm_yday) + | (a->tm_isdst ^ b->tm_isdst)); } static void @@ -544,9 +548,9 @@ print_tm (const struct tm *tp) { if (tp) printf ("%04d-%02d-%02d %02d:%02d:%02d yday %03d wday %d isdst %d", - tp->tm_year + TM_YEAR_BASE, tp->tm_mon + 1, tp->tm_mday, - tp->tm_hour, tp->tm_min, tp->tm_sec, - tp->tm_yday, tp->tm_wday, tp->tm_isdst); + tp->tm_year + TM_YEAR_BASE, tp->tm_mon + 1, tp->tm_mday, + tp->tm_hour, tp->tm_min, tp->tm_sec, + tp->tm_yday, tp->tm_wday, tp->tm_isdst); else printf ("0"); } @@ -578,11 +582,11 @@ main (int argc, char **argv) if ((argc == 3 || argc == 4) && (sscanf (argv[1], "%d-%d-%d%c", - &tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer) - == 3) + &tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer) + == 3) && (sscanf (argv[2], "%d:%d:%d%c", - &tm.tm_hour, &tm.tm_min, &tm.tm_sec, &trailer) - == 3)) + &tm.tm_hour, &tm.tm_min, &tm.tm_sec, &trailer) + == 3)) { tm.tm_year -= TM_YEAR_BASE; tm.tm_mon--; @@ -591,10 +595,10 @@ main (int argc, char **argv) tl = mktime (&tmk); lt = localtime (&tl); if (lt) - { - tml = *lt; - lt = &tml; - } + { + tml = *lt; + lt = &tml; + } printf ("mktime returns %ld == ", (long int) tl); print_tm (&tmk); printf ("\n"); @@ -607,51 +611,51 @@ main (int argc, char **argv) time_t to = atol (argv[3]); if (argc == 4) - for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1) - { - lt = localtime (&tl); - if (lt) - { - tmk = tml = *lt; - tk = mktime (&tmk); - status |= check_result (tk, tmk, tl, &tml); - } - else - { - printf ("localtime (%ld) yields 0\n", (long int) tl); - status = 1; - } - tl1 = tl + by; - if ((tl1 < tl) != (by < 0)) - break; - } + for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1) + { + lt = localtime (&tl); + if (lt) + { + tmk = tml = *lt; + tk = mktime (&tmk); + status |= check_result (tk, tmk, tl, &tml); + } + else + { + printf ("localtime (%ld) yields 0\n", (long int) tl); + status = 1; + } + tl1 = tl + by; + if ((tl1 < tl) != (by < 0)) + break; + } else - for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1) - { - /* Null benchmark. */ - lt = localtime (&tl); - if (lt) - { - tmk = tml = *lt; - tk = tl; - status |= check_result (tk, tmk, tl, &tml); - } - else - { - printf ("localtime (%ld) yields 0\n", (long int) tl); - status = 1; - } - tl1 = tl + by; - if ((tl1 < tl) != (by < 0)) - break; - } + for (tl = from; by < 0 ? to <= tl : tl <= to; tl = tl1) + { + /* Null benchmark. */ + lt = localtime (&tl); + if (lt) + { + tmk = tml = *lt; + tk = tl; + status |= check_result (tk, tmk, tl, &tml); + } + else + { + printf ("localtime (%ld) yields 0\n", (long int) tl); + status = 1; + } + tl1 = tl + by; + if ((tl1 < tl) != (by < 0)) + break; + } } else printf ("Usage:\ \t%s YYYY-MM-DD HH:MM:SS [ISDST] # Test given time.\n\ \t%s FROM BY TO # Test values FROM, FROM+BY, ..., TO.\n\ \t%s FROM BY TO - # Do not test those values (for benchmark).\n", - argv[0], argv[0], argv[0]); + argv[0], argv[0], argv[0]); return status; } |