/*
** This file is in the public domain, so clarified as of
** 1996-06-05 by Arthur David Olson.
*/
/*
** Leap second handling from Bradley White.
** POSIX-style TZ environment variable handling from Guy Harris.
*/
#include "bson-compat.h"
#include "bson-macros.h"
#include "bson-timegm-private.h"
#ifndef BSON_OS_WIN32
#include "errno.h"
#include "string.h"
#include "limits.h" /* for CHAR_BIT et al. */
#include "time.h"
/* Unlike <ctype.h>'s isdigit, this also works if c < 0 | c > UCHAR_MAX. */
#define is_digit(c) ((unsigned)(c) - '0' <= 9)
#ifndef CHAR_BIT
#define CHAR_BIT 8
#endif
#if 2 < __GNUC__ + (96 <= __GNUC_MINOR__)
# define ATTRIBUTE_CONST __attribute__ ((const))
# define ATTRIBUTE_PURE __attribute__ ((__pure__))
# define ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec))
#else
# define ATTRIBUTE_CONST /* empty */
# define ATTRIBUTE_PURE /* empty */
# define ATTRIBUTE_FORMAT(spec) /* empty */
#endif
#if !defined _Noreturn && (!defined(__STDC_VERSION__) || __STDC_VERSION__ < 201112)
# if 2 < __GNUC__ + (8 <= __GNUC_MINOR__)
# define _Noreturn __attribute__ ((__noreturn__))
# else
# define _Noreturn
# endif
#endif
#if (!defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901) && !defined restrict
# define restrict /* empty */
#endif
#ifndef TYPE_BIT
#define TYPE_BIT(type) (sizeof (type) * CHAR_BIT)
#endif /* !defined TYPE_BIT */
#ifndef TYPE_SIGNED
#define TYPE_SIGNED(type) (((type) -1) < 0)
#endif /* !defined TYPE_SIGNED */
/* The minimum and maximum finite time values. */
static time_t const time_t_min =
(TYPE_SIGNED(time_t)
? (time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1)
: 0);
static time_t const time_t_max =
(TYPE_SIGNED(time_t)
? - (~ 0 < 0) - ((time_t) -1 << (CHAR_BIT * sizeof (time_t) - 1))
: -1);
#ifndef TZ_MAX_TIMES
#define TZ_MAX_TIMES 2000
#endif /* !defined TZ_MAX_TIMES */
#ifndef TZ_MAX_TYPES
/* This must be at least 17 for Europe/Samara and Europe/Vilnius. */
#define TZ_MAX_TYPES 256 /* Limited by what (unsigned char)'s can hold */
#endif /* !defined TZ_MAX_TYPES */
#ifndef TZ_MAX_CHARS
#define TZ_MAX_CHARS 50 /* Maximum number of abbreviation characters */
/* (limited by what unsigned chars can hold) */
#endif /* !defined TZ_MAX_CHARS */
#ifndef TZ_MAX_LEAPS
#define TZ_MAX_LEAPS 50 /* Maximum number of leap second corrections */
#endif /* !defined TZ_MAX_LEAPS */
#define SECSPERMIN 60
#define MINSPERHOUR 60
#define HOURSPERDAY 24
#define DAYSPERWEEK 7
#define DAYSPERNYEAR 365
#define DAYSPERLYEAR 366
#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
#define SECSPERDAY ((int_fast32_t) SECSPERHOUR * HOURSPERDAY)
#define MONSPERYEAR 12
#define TM_SUNDAY 0
#define TM_MONDAY 1
#define TM_TUESDAY 2
#define TM_WEDNESDAY 3
#define TM_THURSDAY 4
#define TM_FRIDAY 5
#define TM_SATURDAY 6
#define TM_JANUARY 0
#define TM_FEBRUARY 1
#define TM_MARCH 2
#define TM_APRIL 3
#define TM_MAY 4
#define TM_JUNE 5
#define TM_JULY 6
#define TM_AUGUST 7
#define TM_SEPTEMBER 8
#define TM_OCTOBER 9
#define TM_NOVEMBER 10
#define TM_DECEMBER 11
#define TM_YEAR_BASE 1900
#define EPOCH_YEAR 1970
#define EPOCH_WDAY TM_THURSDAY
#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
/*
** Since everything in isleap is modulo 400 (or a factor of 400), we know that
** isleap(y) == isleap(y % 400)
** and so
** isleap(a + b) == isleap((a + b) % 400)
** or
** isleap(a + b) == isleap(a % 400 + b % 400)
** This is true even if % means modulo rather than Fortran remainder
** (which is allowed by C89 but not C99).
** We use this to avoid addition overflow problems.
*/
#define isleap_sum(a, b) isleap((a) % 400 + (b) % 400)
#ifndef TZ_ABBR_MAX_LEN
#define TZ_ABBR_MAX_LEN 16
#endif /* !defined TZ_ABBR_MAX_LEN */
#ifndef TZ_ABBR_CHAR_SET
#define TZ_ABBR_CHAR_SET \
"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 :+-._"
#endif /* !defined TZ_ABBR_CHAR_SET */
#ifndef TZ_ABBR_ERR_CHAR
#define TZ_ABBR_ERR_CHAR '_'
#endif /* !defined TZ_ABBR_ERR_CHAR */
#ifndef WILDABBR
/*
** Someone might make incorrect use of a time zone abbreviation:
** 1. They might reference tzname[0] before calling tzset (explicitly
** or implicitly).
** 2. They might reference tzname[1] before calling tzset (explicitly
** or implicitly).
** 3. They might reference tzname[1] after setting to a time zone
** in which Daylight Saving Time is never observed.
** 4. They might reference tzname[0] after setting to a time zone
** in which Standard Time is never observed.
** 5. They might reference tm.TM_ZONE after calling offtime.
** What's best to do in the above cases is open to debate;
** for now, we just set things up so that in any of the five cases
** WILDABBR is used. Another possibility: initialize tzname[0] to the
** string "tzname[0] used before set", and similarly for the other cases.
** And another: initialize tzname[0] to "ERA", with an explanation in the
** manual page of what this "time zone abbreviation" means (doing this so
** that tzname[0] has the "normal" length of three characters).
*/
#define WILDABBR " "
#endif /* !defined WILDABBR */
#ifdef TM_ZONE
static const char wildabbr[] = WILDABBR;
#endif
static const char gmt[] = "GMT";
struct ttinfo { /* time type information */
int_fast32_t tt_gmtoff; /* UT offset in seconds */
int tt_isdst; /* used to set tm_isdst */
int tt_abbrind; /* abbreviation list index */
int tt_ttisstd; /* true if transition is std time */
int tt_ttisgmt; /* true if transition is UT */
};
struct lsinfo { /* leap second information */
time_t ls_trans; /* transition time */
int_fast64_t ls_corr; /* correction to apply */
};
#define BIGGEST(a, b) (((a) > (b)) ? (a) : (b))
#ifdef TZNAME_MAX
#define MY_TZNAME_MAX TZNAME_MAX
#endif /* defined TZNAME_MAX */
#ifndef TZNAME_MAX
#define MY_TZNAME_MAX 255
#endif /* !defined TZNAME_MAX */
struct state {
int leapcnt;
int timecnt;
int typecnt;
int charcnt;
int goback;
int goahead;
time_t ats[TZ_MAX_TIMES];
unsigned char types[TZ_MAX_TIMES];
struct ttinfo ttis[TZ_MAX_TYPES];
char chars[BIGGEST(BIGGEST(TZ_MAX_CHARS + 1, sizeof gmt),
(2 * (MY_TZNAME_MAX + 1)))];
struct lsinfo lsis[TZ_MAX_LEAPS];
int defaulttype; /* for early times or if no transitions */
};
struct rule {
int r_type; /* type of rule--see below */
int r_day; /* day number of rule */
int r_week; /* week number of rule */
int r_mon; /* month number of rule */
int_fast32_t r_time; /* transition time of rule */
};
#define JULIAN_DAY 0 /* Jn - Julian day */
#define DAY_OF_YEAR 1 /* n - day of year */
#define MONTH_NTH_DAY_OF_WEEK 2 /* Mm.n.d - month, week, day of week */
/*
** Prototypes for static functions.
*/
static void gmtload(struct state * sp);
static struct tm * gmtsub(const time_t * timep, int_fast32_t offset,
struct tm * tmp);
static int increment_overflow(int * number, int delta);
static int leaps_thru_end_of(int y) ATTRIBUTE_PURE;
static int increment_overflow32(int_fast32_t * number, int delta);
static int normalize_overflow32(int_fast32_t * tensptr,
int * unitsptr, int base);
static int normalize_overflow(int * tensptr, int * unitsptr,
int base);
static time_t time1(struct tm * tmp,
struct tm * (*funcp)(const time_t *,
int_fast32_t, struct tm *),
int_fast32_t offset);
static time_t time2(struct tm *tmp,
struct tm * (*funcp)(const time_t *,
int_fast32_t, struct tm*),
int_fast32_t offset, int * okayp);
static time_t time2sub(struct tm *tmp,
struct tm * (*funcp)(const time_t *,
int_fast32_t, struct tm*),
int_fast32_t offset, int * okayp, int do_norm_secs);
static struct tm * timesub(const time_t * timep, int_fast32_t offset,
const struct state * sp, struct tm * tmp);
static int tmcomp(const struct tm * atmp,
const struct tm * btmp);
static struct state gmtmem;
#define gmtptr (&gmtmem)
static int gmt_is_set;
static const int mon_lengths[2][MONSPERYEAR] = {
{ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
{ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
};
static const int year_lengths[2] = {
DAYSPERNYEAR, DAYSPERLYEAR
};
static void
gmtload(struct state *const sp)
{
memset(sp, 0, sizeof(struct state));
sp->typecnt = 1;
sp->charcnt = 4;
sp->chars[0] = 'G';
sp->chars[1] = 'M';
sp->chars[2] = 'T';
}
/*
** gmtsub is to gmtime as localsub is to localtime.
*/
static struct tm *
gmtsub(const time_t *const timep, const int_fast32_t offset,
struct tm *const tmp)
{
register struct tm * result;
if (!gmt_is_set) {
gmt_is_set = true;
// if (gmtptr != NULL)
gmtload(gmtptr);
}
result = timesub(timep, offset, gmtptr, tmp);
#ifdef TM_ZONE
/*
** Could get fancy here and deliver something such as
** "UT+xxxx" or "UT-xxxx" if offset is non-zero,
** but this is no time for a treasure hunt.
*/
tmp->TM_ZONE = offset ? wildabbr : gmtptr ? gmtptr->chars : gmt;
#endif /* defined TM_ZONE */
return result;
}
/*
** Return the number of leap years through the end of the given year
** where, to make the math easy, the answer for year zero is defined as zero.
*/
static int
leaps_thru_end_of(register const int y)
{
return (y >= 0) ? (y / 4 - y / 100 + y / 400) :
-(leaps_thru_end_of(-(y + 1)) + 1);
}
static struct tm *
timesub(const time_t *const timep, const int_fast32_t offset,
register const struct state *const sp,
register struct tm *const tmp)
{
register const struct lsinfo * lp;
register time_t tdays;
register int idays; /* unsigned would be so 2003 */
register int_fast64_t rem;
int y;
register const int * ip;
register int_fast64_t corr;
register int hit;
register int i;
corr = 0;
hit = 0;
i = (sp == NULL) ? 0 : sp->leapcnt;
while (--i >= 0) {
lp = &sp->lsis[i];
if (*timep >= lp->ls_trans) {
if (*timep == lp->ls_trans) {
hit = ((i == 0 && lp->ls_corr > 0) ||
lp->ls_corr > sp->lsis[i - 1].ls_corr);
if (hit)
while (i > 0 &&
sp->lsis[i].ls_trans ==
sp->lsis[i - 1].ls_trans + 1 &&
sp->lsis[i].ls_corr ==
sp->lsis[i - 1].ls_corr + 1) {
++hit;
--i;
}
}
corr = lp->ls_corr;
break;
}
}
y = EPOCH_YEAR;
tdays = *timep / SECSPERDAY;
rem = *timep - tdays * SECSPERDAY;
while (tdays < 0 || tdays >= year_lengths[isleap(y)]) {
int newy;
register time_t tdelta;
register int idelta;
register int leapdays;
tdelta = tdays / DAYSPERLYEAR;
if (! ((! TYPE_SIGNED(time_t) || INT_MIN <= tdelta)
&& tdelta <= INT_MAX))
return NULL;
idelta = (int) tdelta;
if (idelta == 0)
idelta = (tdays < 0) ? -1 : 1;
newy = y;
if (increment_overflow(&newy, idelta))
return NULL;
leapdays = leaps_thru_end_of(newy - 1) -
leaps_thru_end_of(y - 1);
tdays -= ((time_t) newy - y) * DAYSPERNYEAR;
tdays -= leapdays;
y = newy;
}
{
register int_fast32_t seconds;
seconds = (int_fast32_t) (tdays * SECSPERDAY);
tdays = seconds / SECSPERDAY;
rem += seconds - tdays * SECSPERDAY;
}
/*
** Given the range, we can now fearlessly cast...
*/
idays = (int) tdays;
rem += offset - corr;
while (rem < 0) {
rem += SECSPERDAY;
--idays;
}
while (rem >= SECSPERDAY) {
rem -= SECSPERDAY;
++idays;
}
while (idays < 0) {
if (increment_overflow(&y, -1))
return NULL;
idays += year_lengths[isleap(y)];
}
while (idays >= year_lengths[isleap(y)]) {
idays -= year_lengths[isleap(y)];
if (increment_overflow(&y, 1))
return NULL;
}
tmp->tm_year = y;
if (increment_overflow(&tmp->tm_year, -TM_YEAR_BASE))
return NULL;
tmp->tm_yday = idays;
/*
** The "extra" mods below avoid overflow problems.
*/
tmp->tm_wday = EPOCH_WDAY +
((y - EPOCH_YEAR) % DAYSPERWEEK) *
(DAYSPERNYEAR % DAYSPERWEEK) +
leaps_thru_end_of(y - 1) -
leaps_thru_end_of(EPOCH_YEAR - 1) +
idays;
tmp->tm_wday %= DAYSPERWEEK;
if (tmp->tm_wday < 0)
tmp->tm_wday += DAYSPERWEEK;
tmp->tm_hour = (int) (rem / SECSPERHOUR);
rem %= SECSPERHOUR;
tmp->tm_min = (int) (rem / SECSPERMIN);
/*
** A positive leap second requires a special
** representation. This uses "... ??:59:60" et seq.
*/
tmp->tm_sec = (int) (rem % SECSPERMIN) + hit;
ip = mon_lengths[isleap(y)];
for (tmp->tm_mon = 0; idays >= ip[tmp->tm_mon]; ++(tmp->tm_mon))
idays -= ip[tmp->tm_mon];
tmp->tm_mday = (int) (idays + 1);
tmp->tm_isdst = 0;
#ifdef TM_GMTOFF
tmp->TM_GMTOFF = offset;
#endif /* defined TM_GMTOFF */
return tmp;
}
/*
** Adapted from code provided by Robert Elz, who writes:
** The "best" way to do mktime I think is based on an idea of Bob
** Kridle's (so its said...) from a long time ago.
** It does a binary search of the time_t space. Since time_t's are
** just 32 bits, its a max of 32 iterations (even at 64 bits it
** would still be very reasonable).
*/
#ifndef WRONG
#define WRONG (-1)
#endif /* !defined WRONG */
/*
** Normalize logic courtesy Paul Eggert.
*/
static int
increment_overflow(int *const ip, int j)
{
register int const i = *ip;
/*
** If i >= 0 there can only be overflow if i + j > INT_MAX
** or if j > INT_MAX - i; given i >= 0, INT_MAX - i cannot overflow.
** If i < 0 there can only be overflow if i + j < INT_MIN
** or if j < INT_MIN - i; given i < 0, INT_MIN - i cannot overflow.
*/
if ((i >= 0) ? (j > INT_MAX - i) : (j < INT_MIN - i))
return true;
*ip += j;
return false;
}
static int
increment_overflow32(int_fast32_t *const lp, int const m)
{
register int_fast32_t const l = *lp;
if ((l >= 0) ? (m > INT_FAST32_MAX - l) : (m < INT_FAST32_MIN - l))
return true;
*lp += m;
return false;
}
static int
normalize_overflow(int *const tensptr, int *const unitsptr, const int base)
{
register int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) :
(-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return increment_overflow(tensptr, tensdelta);
}
static int
normalize_overflow32(int_fast32_t *const tensptr, int *const unitsptr,
const int base)
{
register int tensdelta;
tensdelta = (*unitsptr >= 0) ?
(*unitsptr / base) :
(-1 - (-1 - *unitsptr) / base);
*unitsptr -= tensdelta * base;
return increment_overflow32(tensptr, tensdelta);
}
static int
tmcomp(register const struct tm *const atmp,
register const struct tm *const btmp)
{
register int result;
if (atmp->tm_year != btmp->tm_year)
return atmp->tm_year < btmp->tm_year ? -1 : 1;
if ((result = (atmp->tm_mon - btmp->tm_mon)) == 0 &&
(result = (atmp->tm_mday - btmp->tm_mday)) == 0 &&
(result = (atmp->tm_hour - btmp->tm_hour)) == 0 &&
(result = (atmp->tm_min - btmp->tm_min)) == 0)
result = atmp->tm_sec - btmp->tm_sec;
return result;
}
static time_t
time2sub(struct tm *const tmp,
struct tm *(*const funcp)(const time_t *, int_fast32_t, struct tm *),
const int_fast32_t offset,
int *const okayp,
const int do_norm_secs)
{
register const struct state * sp;
register int dir;
register int i, j;
register int saved_seconds;
register int_fast32_t li;
register time_t lo;
register time_t hi;
int_fast32_t y;
time_t newt;
time_t t;
struct tm yourtm, mytm;
*okayp = false;
yourtm = *tmp;
if (do_norm_secs) {
if (normalize_overflow(&yourtm.tm_min, &yourtm.tm_sec,
SECSPERMIN))
return WRONG;
}
if (normalize_overflow(&yourtm.tm_hour, &yourtm.tm_min, MINSPERHOUR))
return WRONG;
if (normalize_overflow(&yourtm.tm_mday, &yourtm.tm_hour, HOURSPERDAY))
return WRONG;
y = yourtm.tm_year;
if (normalize_overflow32(&y, &yourtm.tm_mon, MONSPERYEAR))
return WRONG;
/*
** Turn y into an actual year number for now.
** It is converted back to an offset from TM_YEAR_BASE later.
*/
if (increment_overflow32(&y, TM_YEAR_BASE))
return WRONG;
while (yourtm.tm_mday <= 0) {
if (increment_overflow32(&y, -1))
return WRONG;
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday += year_lengths[isleap(li)];
}
while (yourtm.tm_mday > DAYSPERLYEAR) {
li = y + (1 < yourtm.tm_mon);
yourtm.tm_mday -= year_lengths[isleap(li)];
if (increment_overflow32(&y, 1))
return WRONG;
}
for ( ; ; ) {
i = mon_lengths[isleap(y)][yourtm.tm_mon];
if (yourtm.tm_mday <= i)
break;
yourtm.tm_mday -= i;
if (++yourtm.tm_mon >= MONSPERYEAR) {
yourtm.tm_mon = 0;
if (increment_overflow32(&y, 1))
return WRONG;
}
}
if (increment_overflow32(&y, -TM_YEAR_BASE))
return WRONG;
yourtm.tm_year = y;
if (yourtm.tm_year != y)
return WRONG;
if (yourtm.tm_sec >= 0 && yourtm.tm_sec < SECSPERMIN)
saved_seconds = 0;
else if (y + TM_YEAR_BASE < EPOCH_YEAR) {
/*
** We can't set tm_sec to 0, because that might push the
** time below the minimum representable time.
** Set tm_sec to 59 instead.
** This assumes that the minimum representable time is
** not in the same minute that a leap second was deleted from,
** which is a safer assumption than using 58 would be.
*/
if (increment_overflow(&yourtm.tm_sec, 1 - SECSPERMIN))
return WRONG;
saved_seconds = yourtm.tm_sec;
yourtm.tm_sec = SECSPERMIN - 1;
} else {
saved_seconds = yourtm.tm_sec;
yourtm.tm_sec = 0;
}
/*
** Do a binary search (this works whatever time_t's type is).
*/
if (!TYPE_SIGNED(time_t)) {
lo = 0;
hi = lo - 1;
} else {
lo = 1;
for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i)
lo *= 2;
hi = -(lo + 1);
}
for ( ; ; ) {
t = lo / 2 + hi / 2;
if (t < lo)
t = lo;
else if (t > hi)
t = hi;
if ((*funcp)(&t, offset, &mytm) == NULL) {
/*
** Assume that t is too extreme to be represented in
** a struct tm; arrange things so that it is less
** extreme on the next pass.
*/
dir = (t > 0) ? 1 : -1;
} else dir = tmcomp(&mytm, &yourtm);
if (dir != 0) {
if (t == lo) {
if (t == time_t_max)
return WRONG;
++t;
++lo;
} else if (t == hi) {
if (t == time_t_min)
return WRONG;
--t;
--hi;
}
if (lo > hi)
return WRONG;
if (dir > 0)
hi = t;
else lo = t;
continue;
}
if (yourtm.tm_isdst < 0 || mytm.tm_isdst == yourtm.tm_isdst)
break;
/*
** Right time, wrong type.
** Hunt for right time, right type.
** It's okay to guess wrong since the guess
** gets checked.
*/
sp = (const struct state *) gmtptr;
if (sp == NULL)
return WRONG;
for (i = sp->typecnt - 1; i >= 0; --i) {
if (sp->ttis[i].tt_isdst != yourtm.tm_isdst)
continue;
for (j = sp->typecnt - 1; j >= 0; --j) {
if (sp->ttis[j].tt_isdst == yourtm.tm_isdst)
continue;
newt = t + sp->ttis[j].tt_gmtoff -
sp->ttis[i].tt_gmtoff;
if ((*funcp)(&newt, offset, &mytm) == NULL)
continue;
if (tmcomp(&mytm, &yourtm) != 0)
continue;
if (mytm.tm_isdst != yourtm.tm_isdst)
continue;
/*
** We have a match.
*/
t = newt;
goto label;
}
}
return WRONG;
}
label:
newt = t + saved_seconds;
if ((newt < t) != (saved_seconds < 0))
return WRONG;
t = newt;
if ((*funcp)(&t, offset, tmp))
*okayp = true;
return t;
}
static time_t
time2(struct tm * const tmp,
struct tm * (*const funcp)(const time_t *, int_fast32_t, struct tm *),
const int_fast32_t offset,
int *const okayp)
{
time_t t;
/*
** First try without normalization of seconds
** (in case tm_sec contains a value associated with a leap second).
** If that fails, try with normalization of seconds.
*/
t = time2sub(tmp, funcp, offset, okayp, false);
return *okayp ? t : time2sub(tmp, funcp, offset, okayp, true);
}
static time_t
time1(struct tm *const tmp,
struct tm *(*const funcp) (const time_t *, int_fast32_t, struct tm *),
const int_fast32_t offset)
{
register time_t t;
register const struct state * sp;
register int samei, otheri;
register int sameind, otherind;
register int i;
register int nseen;
int seen[TZ_MAX_TYPES];
int types[TZ_MAX_TYPES];
int okay;
if (tmp == NULL) {
errno = EINVAL;
return WRONG;
}
if (tmp->tm_isdst > 1)
tmp->tm_isdst = 1;
t = time2(tmp, funcp, offset, &okay);
if (okay)
return t;
if (tmp->tm_isdst < 0)
#ifdef PCTS
/*
** POSIX Conformance Test Suite code courtesy Grant Sullivan.
*/
tmp->tm_isdst = 0; /* reset to std and try again */
#else
return t;
#endif /* !defined PCTS */
/*
** We're supposed to assume that somebody took a time of one type
** and did some math on it that yielded a "struct tm" that's bad.
** We try to divine the type they started from and adjust to the
** type they need.
*/
sp = (const struct state *) gmtptr;
if (sp == NULL)
return WRONG;
for (i = 0; i < sp->typecnt; ++i)
seen[i] = false;
nseen = 0;
for (i = sp->timecnt - 1; i >= 0; --i)
if (!seen[sp->types[i]]) {
seen[sp->types[i]] = true;
types[nseen++] = sp->types[i];
}
for (sameind = 0; sameind < nseen; ++sameind) {
samei = types[sameind];
if (sp->ttis[samei].tt_isdst != tmp->tm_isdst)
continue;
for (otherind = 0; otherind < nseen; ++otherind) {
otheri = types[otherind];
if (sp->ttis[otheri].tt_isdst == tmp->tm_isdst)
continue;
tmp->tm_sec += sp->ttis[otheri].tt_gmtoff -
sp->ttis[samei].tt_gmtoff;
tmp->tm_isdst = !tmp->tm_isdst;
t = time2(tmp, funcp, offset, &okay);
if (okay)
return t;
tmp->tm_sec -= sp->ttis[otheri].tt_gmtoff -
sp->ttis[samei].tt_gmtoff;
tmp->tm_isdst = !tmp->tm_isdst;
}
}
return WRONG;
}
time_t
_bson_timegm(struct tm *const tmp)
{
if (tmp != NULL)
tmp->tm_isdst = 0;
return time1(tmp, gmtsub, 0L);
}
#endif